数控机床刀具设计论文中英文资料外文翻译文献综述
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Numerical ControlOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC).Prior to the advent of NC, all machine tools were manual operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator . Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems though the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool, For a machine tool to be numerically controlled , it must be interfaced with a device for accepting and decoding the p2ogrammed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operator , and it has done so . Numerical control machines are more accurate than manually operated machines , they can produce parts more uniformly , they are faster, and the long-run tooling costs are lower . The development of NC led to the development of several other innovations in manufacturing technology:1.Electrical discharge machining.ser cutting.3.Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide variety of par4s , each involving an assortment of undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tools and processes.Like so many advanced technologies , NC was born in the laboratories of the Massachusetts Institute of Technology . The concept of NC was developed in the early 1950s with funding provided by the U.S Air Force .In its earliest stages , NC machines were able to make straight cuts efficiently and effectively.However ,curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter is the straight lines making up the step ,the smoother is 4he curve . Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the further development of NC technology. The original NC system were vastly different from those used punched paper , which was later to replaced by magnetic plastic tape .A tape reader was used to interpret the instructions written on the tape for the machine .Together, all /f this represented giant step forward in the control of machine tools . However ,there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium . It was common for the paper containing the programmed instructions to break or tear during a machining process, This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to rerun thought the reader . If it was necessary to produce 100 copies of a given part , it was also necessary to run the paper tape thought the reader 100 separate times . Fragile paper tapes simply could not withstand the rigors of shop floor environment and this kind of repeated use.This led to the development of a special magnetic tape . Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape , theThis most important of these was that it was difficult or impossible to change the instructions entered on the tape . To make even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape thought the reader as many times as there were parts to be produced . Fortunately, computer technology become a reality and soon solved the problems of NC, associated with punched paper and plastic tape.The development of a concept known as numerical control (DNC) solve the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions . In direct numerical control, machine tools are tied, via a data transmission link, to a host computer and fed to the machine tool as needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However ,it is subject to the same limitation as all technologies that depend on a host computer. When the host computer goes down , the machine tools also experience down time . This problem led to the development of computer numerical control.The development of the microprocessor allowed for the development of programmable logic controllers (PLC) and microcomputers . These two technologies allowed for the development of computer numerical control (CNC).With CNC , each machine tool has a PLC or a microcomputer that serves the same purpose. This allows programs to be input and stored at each individual machine tool. CNC solved the problems associated downtime of the host computer , but it introduced another problem known as data management . The same program might be loaded on ten different microcomputers with no communication among them. This problem is in the process of being solved by local area networks that connectDigital Signal ProcessorsThere are numerous situations where analog signals to be processed in many ways, like filtering and spectral analysis , Designing analog hardware to perform these functions is possible but has become less and practical, due to increased performance requirements, flexibility needs , and the need to cut down on development/testing time .It is in other words difficult pm design analog hardware analysis of signals.The act of sampling an signal into thehat are specialised for embedded signal processing operations , and such a processor is called a DSP, which stands for Digital Signal Processor . Today there are hundreds of DSP families from as many manufacturers, each one designed for a particular price/performance/usage group. Many of the largest manufacturers, like Texas Instruments and Motorola, offer both specialised DSP’s for certain fields like motor-control or modems ,and general high-performance DSP’s that can perform broad ranges of processingtasks. Development kits an` software are also available , and there are companies making software development tools for DSP’s that allows the programmer to implement complex processing algorithms using simple “drag ‘n’ drop” methodologies.DSP’s more or less fall into t wo categories depending on the underlying architecture-fixed-point and floating-point. The fixed-point devices generally operate on 16-bit words, while the floating-point devices operate on 32-40 bits floating-point words. Needless to say , the fixed-point devices are generally cheaper . Another important architectural difference is that fixed-point processors tend to have an accumulator architecture, with only one “general purpose” register , making them quite tricky to program and more importantly ,making C-compilers inherently inefficient. Floating-point DSP’s behave more like common general-purpose CPU’s ,with register-files.There are thousands of different DSP’s on the market, and it is difficult task finding the most suitable DSP for a project. The best way is probably to set up a constraint and wishlist, and try to compare the processors from the biggest manufacturers against it.The “big four” manufacturers of DSPs: Texas Instruments, Motorola, AT&T and Analog Devices.Digital-to-analog conversionIn the case of MPEG-Audio decoding , digital compressed data is fed into the DSP which performs the decoding , then the decoded samples have to be converted back into the analog domain , and the resulting signal fed an amplifier or similar audio equipment . This digital to analog conversion (DCA) is performed by a circuit with the same name & Different DCA’s provide different performance and quality , as measured by THD (Total harmonic distortion ), number of bits, linearity , speed, filter characteristics and other things.The TMS320 family DQP of Texas InstrumentsThe TLS320family consists of fixed-point, floating-point, multiprocessor digital signal processors (D[Ps) , and foxed-point DSP controllers. TMS320 DSP have an architecture designed specifically for real-time signal processing . The’ F/C240 is a number of the’C2000DSP platform , and is optimized for control applications. The’C24x series of DSP controllers combines this real-time processing capability with controller peripherals to create an ideal solution for control system applications. The following characteristics make the TMS320 family the right choice for a wide range of processing applications:--- Very flexible instruction set--- Inherent operational flexibility---High-speed performance---Innovative parallel architecture---Cost effectivenessDevices within a generation of the TMS320 family have the same CPU structure but different on-chip memory and peripheral configurations. Spin-off devices use new combinations of On-chip memory and peripherals to satisfy a wide range of needs in the worldwide electronics market. By integrating memory and peripherals onto a single chip , TMS320 devices reduce system costs and save circuit board space.The 16-bit ,fixed-point DSP core of the ‘C24x devices provides analog designers a digital solution that does not sacrifice the precision and performance of their system performance can be enhanced through the use of advanced control algorithms for techniquessuch as adaptive control , Kalman filtering , and state control. The ‘C24x DSP controller offer reliability and programmability . Analog control systems, on the other hand ,are hardwired solutions and can experience performance degradation due to aging , component tolerance, and drift.The high-speed central processing unit (CPU) allows the digital designer to process algorithms in real time rather than approximate results with look-up tables. The instruction set of these DSP controllers, which incorporates both signal processing instructions and general-purpose control functions, coupled with the extensive development time and provides the same ease of use as traditional 8-and 16-bit microcontrollers. The instruction set also allows you to retain your software investment when moving from other general-purp ose‘C2xx generation ,source code compatible with the’C2x generation , and upwardly source code compatible with the ‘C5x generation of DSPs from Texas Instruments.The ‘C24x architecture is also well-suited for processing control signals. It uses a 16-bit word length along with 32-bit registers for storing intermediate results, and has two hardware shifters available to scale numbers independently of the CPU . This combination minimizes quantization and truncation errors, and increases p2ocessing power for additional functions. Such functions might include a notch filter that could cancel mechanical resonances in a system or an estimation technique that could eliminate state sensors in a system.The ‘C24xDSP controllers take advantage of an set of peripheral functions that allow Texas Instruments to quickly configure various series members for different price/ performance points or for application optimization.This library of both digital and mixed-signal peripherals includes:---Timers---Serial communications ports (SCI,SPI)---Analog-to-digital converters(ADC)---Event manager---System protection, such as low-voltage and watchdog timerThe DSP controller peripheral library is continually growing and changing to suit the of tomorrow’s embedded control marke tplace.The TMS320F/C240 is the first standard device introduced in the ‘24x series of DSP controllers. It sets the standard for a single-chip digital motor controller. The ‘240 can execute 20 MIPS. Almost all instructions are executed in a simple cycle of 50 ns . This high performance allows real-time execution of very comple8 control algorithms, such as adaptive control and Kalman filters. Very high sampling rates can also be used to minimize loop delays.The ‘ 240 has the architectural features necessary for high-speed signal processing and digital control functions, and it has the peripherals needed to provide a single-chip solution for motor control applications. The ‘240 is manufactured using submicron CMOS technology, achieving a log power dissipation rating . Also included are several power-down modes for further power savings. Some applications that benefit from the advanced processing power of the ‘240 include:---Industrial motor drives---Power inverters and controllers---Automotive systems, such as electronic power steering , antilock brakes, and climatecontrol---Appliance and HV AC blower/ compressor motor controls---Printers, copiers, and other office products---Tape drives, magnetic optical drives, and other mass storage products---Robotic and CNC milling machinesTo function as a system manager, a DSP must have robust on-chip I/O and other peripherals. The event manager of the ‘240 is unlike any other available on a DSP . This application-optimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for high-precision and high-efficiency full variable-speed control of all motor types. Include in the event manager are special pulse-width modulation (PWM) generation functions, such as a programmable dead-band function and a space vector PWM state machine for 3-phase motors that provides state-of-the-art maximum efficiency in the switching of power transistors.There independent up down timers, each with it’s own compare register, suppo rt the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.Open-Loop and Closed-Loop ControlOpen-loop Control SystemsThe word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to a variety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed.g the feedback structure, it is called an open-loop system , which is the simplest and most economical type of control system.inaccuracy lies in the fact that one may not know the exact characteristics of the further ,which has a definite bearing on the indoor temperature. This alco points to an important disadvantage of the performance of an open -loop control system, in that the system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of the furnace control, perhaps an experienced person can provide control for a certain desired temperature in the house; but id the doors or windows are opened or closed intermittently during the operating period, the final temperature inside the house will not be accurately regulated by the open-loop control.An electric washing machine is another typical example of an open-loop system , because the amount of wash time is entirely determined by the judgment and estimation of the human operator . A true automatic electric washing machine should have the means of checking the cleanliness of the clothes continuously and turn itsedt off when the desired degised of cleanliness is reached.Closed-Loop Control SystemsWhat is missing in the open-loop control system for more accurate and more adaptable control is a link or feedback from the output to the input of the system . In order to obtain more accurate bontrol, the controlled signal c(t) must be fed back and compared with the reference input , and an actuating signal proportional to the difference of the output and the input must be sent through the system to correct the error. A system with one or more feedback pat(s like that just described is called a closed-loop system. human being are probably the most complex and sophisticated feedback control system in existence. A humanbeing may be considered to be a control system with many inputs and outputs, capable of carrying out highly complex operations.To illustrate the human being as a feedback control system , let us consider that the objective is to reach for an object on aperform the task. The eyes serve as a sensing device which feeds back continuously the position of the hand . The distance between the hand and the object is the error , which is eventually brought to zero as the hand reacher the object. This is a typical example of closed-loop control. However , if one is told to reach for the object and then is blindolded, one can only reach toward the object by estimating its exact position. It isAs anther illustrative example of a closed-loop control system, shows the block diagram of the rudder control system ofThe basic alements and the bloca diagram of a closed-loop control system are shown in fig. In general , the configuration of a feedback control system may not be constrained to that of fig & . In complex systems there may be multitude of feedback loops and element blocks.数控在先进制造技术领域最根本的观念之一是数控(NC)。
数控加工技术概述外文翻译、中英文翻译、外文文献翻译
原文:The digital control process technology is summarized1. digital control programming reaches such developmentThe digital control programming is the segment that be able to obviously bring into play the beneficial result in at the moment CAD/CAPP/CAM's system the most most , such is living to achieve to design the process automation and raise process accuracy and processes the quality and cuts down the product development cycle and so on the respect is brining into play the significant action . Being living possess the greats quantity applications such as aviation industry and auto industry and so on territorys . Since giving birth to the intense demand of practice , wide-ranging research has wholly been carried on to the digital control programming technique in the home and abroad , and acquires the plentiful and substantial fruit . The next reaches such to the digital control programming and develops to act as some to introduce .1.1 basic concept of digital control programmingThe digital control programming is through the spare parts drawings up the full process that obtains the digital control processing program . Its main mission is that the sword spot ( Cutterlocationpoint abbreviate CL's spot ) in the sword is processed away in the calculation .The point of intersection that sword the spot was oridinarily get to the cutting tool axial line against the cutting tool face still will be give out the sword shaft vector in much processs1.2 digital control programming technique development surveyMIT designed one kind of special language that is used in the inflexible spare parts digital control processing program establishments to the program problem in order to resolve in the digital control process , andis called APT ( AutomaticallyProgrammedTool ) in the 50's .Well-developed editions such as after APT time and again develops , takeed shape such as APTII and APTIII ( the stereoscopic cutting action is employd ) and APT ( the algorithm improves , add much coordinates surface processes the programming meritorous service capacity ) and APTAC ( Advancedcontouring ) ( add cuts the database administration system ) and APT/SS ( SculpturedSurface ) ( add engraves the camber processes the programming meritorous service capacity ) and so on .Adoping APT language drawing up digital control order to have easy the refineing of order , and gos away the strongs point such as sword control is agile and so on , and causes the digital control process the programming , and moves upward up yet possess much not suitable points to geometry element .APT through " assemble language " grade to the machine tool order : Adoping language definition spare parts geometry form shape , and is difficult to depict complex geometry form shape , and lack audio-visual quality of geometry ;The certification measure that the figure audio-visual that is short of to spare parts form shape and the cutting tool movement locus displays and the cutting tool locus ;Being difficult to effectively join with CAD's data bank and CAPP's system ;Not to act as easily up the high automation , the integrationizationIn view of the APT's language defect , in 1978 , France attained the system that the large rope airplane corporation starts development gathers assemble three dimensions design , analysis and NC's process integration , and is called in the interest of CATIA .Having ariseed alikely the systems such as EUCLID and NPU/GNCP and so on soon afterwards very quickly , the geometry moldswholly valid settlements of these systems and the spare parts geometry form shape display is designed mutually and mends generates the cutting tool locus , and the problems such as the imitation to go away the sword process displays and certification and so on promoteed CAD and CAM developing to the integration orientation . The approximately idea that system ( CIMS ) and parallel project ( CE ) was manufacture in the calculating machine integration take shape up the 80's gradually on the base that the CAD/CAM's integration being living is approximately attend school . At the moment , and the necessaries that CE developed in order to adapt to CIMS , the digital control programming system to integrationization and intelligentization the development .Being living the integration respect , with the development accords with the STEP ( StandardfortheExchangeofProductModelData ) criterion parameterization feature moldmaking and systematically gives priority to , having carried on the highly effective work of greats quantity at the moment is the home and abroad development heatpointBeing living the intelligentization respect , the work has start only a short while ago , and still awaits that we leave hard2、NCs' cutting tool locus generates the method study developing actualityDigital control programming core work is generateing the cutting tool locus , afterwards by such scattered one-tenth sword spot , places that the handle comes into being the digital control processing program afterwards viaing .The next cutting tool locus comes into being the means and actes as some and introduce2.1 baseding on a little and string , surface and part of the body NC's sword track formation meansCAD's technique moves through the two dimension mapping , andudergo the three dimensions wires frame and camber and the solid modelling generation , now the parameterization feature reacing is always moldded .Is living two dimension mapping together with three dimensions wires frame phase , in case the opening processes , the rough sketch is processed the digital control process is main with spot and string act as drive target , the plane area process and so on .This kind of level that personnel staff was requireed manipulating in the process is taller , complex mutually .Being living camber and the solid modelling generation , entity process had ariseed to based on .The entity process target is an entity ( oridinarily blendes for CSG and BREP express ) , its ( moreover , intersects , falls short of to operate ) but get yield through some fundamental parts of the body habitually after the set operation .The entity is processed not merely usable rough machining and semi precision work to the spare parts , and the great area cuts Yu Liang , and the effectiveness is processed in the raise , but also usable research together with development to digital control baseding on the feature programming system , is the feature process baseEntity process oridinarily possess entity rough sketch process and the entity area and processes two kinds .The entity process realization means slices law ( SLICE ) in the interest of the straturm , in immediate future slices by the process entity in the way of one series of level , afterwards to obtains the intersection comes into being the isometry string dos worthwhile the sword the going away locus .The original slave system needs the angle depart , the digital control process that the ACIS's geometry moldmaking being living achieved thiskind to based on a little on the terrace and the string and surface and entity Feature NC's sword track formation means 2.2 baseding onThe parameterization feature molds to possess the specified development particular period , yet baseds on that feature cutting tool locus formation means research starts only a short while ago .The feature processes to cause digital control programming personnel staff to be out to let drop the step geometry message to those ( in case : Spot , string , surface and entity ) manipulate , but transforing to carry on the digital control programming in the interest of directly to accords with the feature that engineers and technicians are used to , and liftd the programming effectiveness enormouslyW.R.Mail and A.J.Mcleod are living in their research to give out one to based on feature NC's code generating sub system , and this systematic work rule is : Spare parts every one process wholly may be regarded as to adjust to make up the total that the spare parts form shape feature group processed .In immediate future the queen completees spare parts process is not processed that to the feature adjusting entirely form the shape in that way either form shape feature component .But each form shape feature either form shape feature series NC's code may generate voluntarily .The system opened up at the moment merely is applicable to 2.5D's spare parts processThe LeeandChang opened up one kind of raised liberal camber feature cutting tool locus of means autogeneration in the way of fictitious border system .This systematic work rule is : Being living to inlay inner place the raised liberal camber into one the minimal long and square , so raised liberal camber feature is transformd into the hollow feature .Minimal the long and square incorporation against the end product pattern constituteed to be called one kind of indirect produce pattern on the fictitious pattern .That the cutting tool locus formation means separates into completees three paces : ( 1 ) and the cutting action polyhedron feature ;( 2 ) and cuts the liberal camber feature ;( 3 ) and the cutting action intersects the featureJongYunJung researcies baseds on the non- cutting action cutting tool locus formation problem of feature .The article process baseding on the feature locus separates into rough sketch process and processes two types with the inside area , and the definition this two types of process cutting action orientations , attains the aim that the entirety optimizes the cutting tool locus by means of decreasing the cutting action cutting tool locus .Type who talked about these fundamental features gos away sword way and cutting tool selection and process order and so on to main being aimed at of article some kinds of fundamental features ( hollow inner place Kong and step , trough ) , and averting repeatedly going away the sword by means of IP ( InterProgramming ) technique , with the non- cutting action cutting tool locus of optimization .Besides JongYunJong still is living , and his doctor in 1991 researcied tabrication feature extraction and baseds on feature cutting tool and the cutting tool way in the dissertationThe feature process base is an entity process , and surely of course also may think the entity process being more high-quality .Yet feature process distinct entity process , and entity process possess it oneself the limitations .Feature process chiefly possess below difference against entity process :Through approximately attends school says that the feature is the meritorous service capacity key element to make up the spare parts , and the operation that accords with engineers and technicians is used to , by engineers and technicians are know intimately ;The entity is the geometry target on low straturm , and is a geometric object that obtains after a series of Booleans calculation , and does not have whatever meritorous service capacity semantic information ;It frequently is adjusting the once only process of entire spare parts ( entity ) that the entity is processed .Yet in reality the spare parts is not very much probably merely once processed through in the way of the sword , frequently will go through a series of workmans of rough machining and semi precision work and precision work and so on stage , the place of spare parts difference oridinarily will be employd the difference cutting tool and process ;Now and then not only the spare parts will be employd up turning , but also employ up mill .Hence entity process is chiefly used spare parts rough machining and semi precision work .But but the feature on processing through essentially resolved the above-mentioned issue ;Feature process havees even more intellect .May regulate some kinds of settled admittedly process meanss as to the specially designated feature , particularly those have been living , and STEP's criterion the person who regulates the feature still more is such in this way .In case we wholly draw up the specially designated process means to all standards feature , it is you can imagine that spare parts that in thatway sufficiently succeed through the standard feature to those are processed such convenient quality .In case CAPP systematically be able to supply the relevant technology feature , NCP's system may decrease inputing mutually , and havees even more intellect enormously in that way .But these entity process can not achievedFeature process is favour of achieving through comprehensive integration of CAD , CAPP , NCP and CNC's system , and achieves the two-way going from place to place of message , in the interest of CIMS and even parallel project ( CE ) are settleed the well base ;It be helpless that but the entity is processed to theseNC's sword track formation means 2.3 being on active service in several main CAD/CAM's systems is analysedActive duty CAM constitutes reaching the main meritorous service capacityThat at the moment comparatively more mature CAM's system is main with two kinds of shapes achieves CAD/CAM's system integration : Integration CAD/CAM's system ( in case : UGII , Euclid and Pro/ENGINEERs and so on ) and independent relatively CAM's system ( in case : Mastercam and Surfcams and so on ) . Unitary less than the former data format is directly gaind the produce geometric model through CAD's system , but the latter is main gains the produce geometric model by means of the neutral papers through else CAD's systems . However , no matter is what the CAM's system growed the shape , wholly consising of five modules , in immediate future mutually technology parameter input module and cutting tool locus formation module and cutting tool locus compiler module and three dimensions process that dynamic imitation module and afterwards places the processing module . Next merely some famous CAD/CAM's system NC's process meanss are holied discussions .UGII's process means is analysedOridinarily think that UGII is the best in trade circle , and havees representativeness digital control software most .That such havees the distinguishing feature most is the cutting tool locus formation means that such meritorous service capacity is powerful .Consists of turning , milling and string cuts and so on the consummate process means .In it milling chiefly possess the below meritorous service capacity :And PointtoPoint: Completeing the different openings processesAnd PanarMill: Plane is milled .Consising of that the one-way walkes surely , the two-way row are slice , and the hoop is slice along with rough sketch process to await And FixedContour: Admittedly much projectionss are areed processed stably .Dominateeing on being living on the single camber either much camber the removing of cutting tool in the way of the projection means , and that the control cutting tool is removed may be the cutting tool locus that has generateed , a series of either suite stringAnd VariableContour: Variable projection is processedAnd Parameterline: Await that the parameter string is processed .The successive process of single camber either much camber may be adjustAnd ZigZagSurface: Cutting out processAnd RoughtoDepth: Rough machining .The depth is reachd assigning in the rough machining by Mao PiAnd CavityMill: The many stages depth mould cavity processes .Rough machining that particularly is applicable to the male contact with the hollow standardAnd SequentialSurface: The camber occuies simultaneously the workman .In accordance the spare parts and guides that and the thinking of check adjust the removing suppling the largesttest degree control of cutting toolEDSUnigraphics still consists of greats quantity else the respects meritorous service capacitys , and did not enumerate one by one here STRATA's process means is analysedSTRATA is a digital control programming system development environment , and it is establishing ACIS's geometry model building terrace onIt supplys two kinds of programming development environments in the interest of consumer , in immediate future NC's command language interface and the NC's operation C++ storehouse . It may back three to mill , and turning and string cut NC and process , and may back wire frame , camber and the entity geometry model building . Such NC's cutting tool locus formation means is baseding on the physical model . STRATA is baseded on , and what supplys the process means in entity NC's cutting tool locus formation type storehouse consists of : ProfileToolpath: Rough sketch processAreaClearToolpath: The area on plane processesSolidProfileToolpath: The entity rough sketch is processedSolidAreaClearToolpath: The area on entity plane processesSolidFaceToolPath: The entity face processesSolidSliceToolPath: The entity severs process on planeLanguagebasedToolpath: Baseding on , language cutting tool locus generatesElse CAD/CAM software , in case Euclid the person who awaits the NC's meritorous service capacity is each has his strong point , yet suchfundamental substance is almost alike , the not natural difference .2.4 main problem of systematic sword track formation means of active duty CAMIn accordance tradition CAD/CAM's system and CNC's system work means , CAM's system is with directly either the indirect means gains the produce geometry data model through CAD's system ( by means of neutral papers ) . CAM's system is with spot , string , surface in the three dimensions geometrics model and either the entity is the drive target , the cutting tool locus is processed in the formation , and afterwards the shape with the cutting tool locating file viaes the handle is placed , with the NC's code shape supplys to CNC's machine tool , the some respects problems under being living in entire CAD/CAM and the CNC's system operation process to be :CAM systematically can only gain produce low tier of geometry message through CAD's system , and can not seize voluntarily meritorous service capacity and the semantic information of produce geometry shape information and produce higher level .Hence manufacturing engineering master that entire CAM's process have to be living is very experience haves a hand in secondly , and completees mutually by means of the figure .In case : Manufacturing engineering master .The entire system automation degree is leted dropBeing living in the CAM's system generation cutting tool locus , equal also merely embodying low straturm geometry message ( right line and arc geometry locating information ) , along with the a little process control information ( as moving forward ) to rate , main shaft rotation speed and trading sword and so on .Hence , can not obtain the process technology parameter that haves something to do with against generateing the cutting tool locus yetThe produce data between CAM's system every module are not unitied , and the independence is opposite to each other to every module .For instance the cutting tool locating file is merely keep the minutes the cutting tool locus and is not keep the minutes the relevant process technology parameter , the dynamic imitation of three dimensions merely keeps the minutes that the cutting tool locus interference against runs into , but keep the minutes interference and process target and correlation process technology parameter that runs into happen against suchThe CAM systematically is an independence system .Not thering is the unitary produce data model between CAD's system together with the CAM's system , even if being the integrated CAD/CAM's system of integration in , one-way and unity is enjoyed also being only to message in all . CAM systematically can not sufficiently comprehend and complete message utilizing CAD's system to have something to do with the produce , feature message that especially haves something to do with against process , equal CAD's system can not gain the process data message that CAM systematically come into being yet . This is give parallel project implementation to bring the hardship3、digitals control techniques of simulation3.1 calculating machine imitation approximately idea and applicationThe angle through the project is see , and the imitation is the system by means of the test to the system model leave to research in the existing either design .Analysing the complex dynamic target , the imitation is one kind of valid means , may decrease the hazard , cuts down design and manufactures cycle , and practise thrift the investment .Calculating machine imitation is draing support from the calculatingmachine , and utilizes the system model to adjust actually systematically testing the process which researcied .It is swiftly developed in the wake of the calculating machine technique development , and is living in the imitation to passess the more and more significant position .Three foundation maneuveies between the key element that the calculating machine imitation process may be notify by means of the picture 1 are depictd :The model building maneuver is by means of viewing either examination to the actual system , and is living to over look the less important element to reach on the base that examine the variable , and the means in the way of physics either mathematics is depictd , thereby obtains the similar pattern of actual system simplification .The meritorous service with the actual system of the pattern here be able to together with between the parameter ought to have similarity and homologous qualityThe imitation pattern is the mathematical model to the system ( simplifying the pattern ) carries on the specified algorithm handle , and causes such become the appropriate shape ( in case turns into iterative operation pattern by the numerical integration ) afterwards , yet becomes " computation module computational mode " that be able to be receiveed by the calculating machine .The imitation pattern is two simplification patterns to the actual systemThe imitation test is shall system imitation pattern be living the process rund in the calculating machine .The imitation is researching actual system one kind of technique by means of the test , may clarify systematically immanent structure variable and the ambient condition effect by means of the technique of simulationCalculating machine technique of simulation main expressing of development tendency be living two respects : Application territory enlargement and imitation calculating machine intelligentization .The calculating machine technique of simulation not merely is living tradition project technique territory ( respects such as aviation , spaceflight and chemical industry and so on ) subsequent development , but also broadens up community economy and living beings and so on much non- project territorys , moreover , technique such as parallel processing , artificial intelligence , knowledge base and expert system and so on the development is affecing the imitation calculating machine development Digital control process imitation utilizes the calculating machine imitation practice process , being the forceful means to verify digital control processing program dependability and the calculation cutting action process , in order to decrease work attempies surely , and lifts production efficiency3.2 digital control technique of simulation research present situationThe APT process spare parts are completeed near the digital control order program control .In the interest of right quality to guarrantee the digital control order , guard against in process to intervene happenning , and is living in the actual manufacture , and constantly adopts attempting the anxious means to examine with what runs into .Yet this kind of means requiring a lot of labor expense is anticipateed , the cost expansively causes the manufacturing cost move upward , addd produce process time and production cycle .Adoping once more the locus to display the law afterwards , in immediate future in order to mark needle either pencil or writing brush replace the cutting tool , with colouring plank either paper replaces the work imitation cutting tool movement locus two dimension figure ( alsomay display the two dimension semi process locus ) , possess the considerably great limitations .Three dimension and the many-dimensionss as to the work are processed , the cutting action locus that the inspection that the stuff that also possess use easily to cut replaces the work ( in case , paraffin wax , lumber , midified resin and plastic material and so on ) comes is processed .Yet APT and the process field is very important occupied in the attempt .For this reason , people are living always to research replace gradually attempting the anxious calculating machine emulation mode , and is living to attempt to slice that the respects such as environment modeling and imitation calculation and graphic display and so on acquire the significant progress , and develops to raise pattern accurateness and imitation calculation real timeization and improvement real feeling of graphic display and so on orientations at the momentThrough attempies the pattern distinguishing feature sliceeing the environment seeing , NC's cutting action process imitation branch geometry imitation and mechanics imitation at the moment two respects .Geometry imitation is not consider that cutting action parameter and cutting force reach else the physics elements effects , the imitation cutting tool work geometric object movement , and with right quality of certification NC's order .The problem such as it may decrease either remove as a result of the machine tool injury that the program error causes and clamping apparatus damage either the cutting tool rolls over to snap and the spare parts are reported something as worthless and so on ;May decrease moreover through the product design up time manufacturing , and cut down the manufacturing cost .Cutting action process mechanics imitation pertains to the physics imitation category , and its dynamic mechanics property by means of the imitation cutting action process is forecast that the cutting tool breakage and cutting tool vibration and control cuts the parameter , thereby attains to optimize the cutting action process aimThe geometry technique of simulation development is in the wake of geometry model building technique development but development , and consists of that quality graphic display and the ration is intervened verifying two respects .At the moment the means in common use possess the immediate solid modelling law , and the means of figure image space baseding on is requestted the intersection law with the scattered vector3.3 immediate solid modelling lawThis kind of enveloping solid that the means is the work part of the body against the cutting tool movement takes shape is underway that the entity Boolean falls short of operating , and the work part of the body three dimensions patterns are continuously replaceed in the wake of the cutting action processSungurtekin and Velcker opened up a miller simulation system .The three dimensions patterns that ought to systematically adopt CSG's law to keep the minutes Mao Pi utilize some fundamental primitives like cuboid , the cylindrical body and taper part of the body , and the set operation , particularly operating , the area by Mao Pi and a series of cutting tool scannings is keep the minutes , afterwards usies the set difference and operates through Mao Pizhong's order take-offing the scanning area .Traverse when the so-called area by has sweep is cutting the cutting tool to move along some locuss area .Per length of Mao Pixing's shape that NC's code afterwards。
机床的论文中英文资料外文翻译文献
机床的论文中英文资料外文翻译文献引言机床是制造业中重要的设备,用于加工各种零部件和制造产品。
本文汇总了关于机床的论文中英文资料的外文翻译文献,以供参考和研究使用。
外文翻译文献列表Author: John Smith John SmithYear: 2015 20152. Title: Advanced Techniques for Machine Tool Analysis Title: Advanced Techniques for Machine Tool AnalysisAuthor: Jennifer Lee Jennifer LeeYear: 2016 20163. Title: Intelligent Control Systems for Precision Machining Title: Intelligent Control Systems for Precision MachiningAuthor: David Wang David WangYear: 2018 2018Abstract: This paper focuses on intelligent control systems for precision machining. It discusses the integration of artificial intelligence and control algorithms to enhance the precision and performance of machine tools. The paper presents case studies on the application of intelligent control systems in precision machining processes. This paper focuses on intelligent control systems for precision machining. It discusses the integration of artificial intelligence and control algorithms to enhance the precision and performance of machine tools. The paper presents case studies on the application of intelligent control systems in precision machining processes.4. Title: Advances in Machining Processes for Hard-to-Machine Materials Title: Advances in Machining Processes for Hard-to-Machine MaterialsAuthor: Emily Chen Emily ChenYear: 2019 2019Abstract: This paper reviews recent advances in machining processes for hard-to-machine materials. It discusses the challenges associated with machining materials such as titanium, nickel-basedalloys, and ceramics. The paper highlights the development of new cutting tools, machining strategies, and technologies to improve the machinability of these materials. This paper reviews recent advances in machining processes for hard-to-machine materials. It discusses the challenges associated with machining materials such as titanium, nickel-based alloys, and ceramics. The paper highlights the development of new cutting tools, machining strategies, and technologies to improve the machinability of these materials.5. Title: Optimization of Machining Parameters for Energy Efficiency Title: Optimization of Machining Parameters for Energy EfficiencyAuthor: Michael Liu Michael LiuYear: 2020 2020Abstract: This paper explores the optimization of machining parameters for energy efficiency. It discusses the impact of machining parameters, such as cutting speed, feed rate, and depth of cut, on energy consumption in machining processes. The paper presents optimization techniques and case studies on reducing energy consumption in machining operations. This paper explores theoptimization of machining parameters for energy efficiency. It discusses the impact of machining parameters, such as cutting speed, feed rate, and depth of cut, on energy consumption in machining processes. The paper presents optimization techniques and case studies on reducing energy consumption in machining operations.结论以上是关于机床的论文中英文资料的外文翻译文献,希望对研究和了解机床技术的人员有所帮助。
机械类数控车床外文翻译外文文献英文文献数控
数控加工中心技术开展趋势及对策原文来源:Zhao Chang-ming Liu Wang-ju (CNC Machining Process and equipment, 2002,China)一、摘要Equip the engineering level, level of determining the whole national economy of the modernized degree and modernized degree of industry, numerical control technology is it develop new developing new high-tech industry and most advanced industry to equip (such as information technology and his industry, biotechnology and his industry, aviation, spaceflight, etc. national defense industry) last technology and getting more basic most equipment. Numerical control technology is the technology controlled to mechanical movement and working course with digital information, integrated products of electromechanics that the numerical control equipment is the new technology represented by numerical control technology forms to the manufacture industry of the tradition and infiltration of the new developing manufacturing industry,Keywords:Numerical ControlTechnology, E quipment,industry二、译文数控技术和装备开展趋势及对策装备工业的技术水平和现代化程度决定着整个国民经济的水平和现代化程度,数控技术及装备是开展新兴高新技术产业和尖端工业〔如信息技术及其产业、生物技术及其产业、航空、航天等国防工业产业〕的使能技术和最根本的装备。
分析数控机床改造外文文献翻译、中英文翻译、外文翻译
Analysis of transformation of numerical controlmachine toolIn order to survival and development of enterprises, improve the rate of CNC machine tools is necessary. Transformation of the equipment needed for NC machine tools in general, including traditional and recently introduced from abroad, due to a problem can not be put into the machine tool equipment and production lines. First, transform the contents of the NCCNC machine tools and production line transformation of the main contents are: (1) restoration of the original function, machine tools, production lines there is some fault diagnosis and recovery; (2)NC-based, in the general machine tools addend remarkable device or add numerical control system; ( 3) The renovation, to improve accuracy, efficiency and degree of automation, mechanical, electrical parts of the renovation, the mechanical part of there-assembly process, to restore the original precision; can not meet the production requirements of its CNC system be updated with the latest CNC; (4) technology updates or technical innovation, in order to improve performance or grade, or for the use of new technology, new technology, based on the original large-scale technology updates or technical innovation.Second, the development trend of CNC systeml. To open, the sixth generation of PC-based directionThe openness of the PC-based, low-cost, high reliability, rich in natural resources such as hardware and software features, and more CNC system manufacturer will be to go down this path. At least with PC, as its front-end machines, to deal with man-machine interface, programming, networking and communications issues, the original system to take over some tasks PC CNC machines has the friendly interface, will reach all of the CNC system. The remote communication, remote diagnostics and maintenance of applications will be more common.2. To the development of high-speed and high precision.3. To the intelligent direction(1) The application of adaptive control technology. Numerical control system can detect the process of important information and automatically adjust system parameters, improving the system operation status.2) the introduction of expert systems to guide processing. Will be skilled workers and expertise, processing and general laws and special laws into the system to process parameter database support, establish an artificial intelligence expert system.(3) the introduction of fault diagnosis expert system(4) intelligent digital servo drives. Can automatically identify the load and automatically adjust the parameters of the drive system to get the best state of operation.Third, the choice of numerical control system1. Open-loop systemThe system's servo-driven device is a stepper motor, power stepper motors, electro-hydraulic pulse motors. This system does not require position and velocity feedback, displacement accuracy depends mainly on the angular displacement precision stepper motor and gear drive components such as precision screw, so displacement of low accuracy. But the system is simple, debugging easy maintenance, reliable, low cost, easily converted successfully.2. Closed-loop systemThe system consists of grating, sensor position detection device synchronization, etc. The actual measured position signal fed back to the computer, compared with a given value, the difference between the two amplification and transformation, driving the implementing agencies in order to eliminate bias. The system complexity, high cost and strict temperature requirements on the environment. But thesystem of high precision, speed and big power. According to technological requirements and decide whether to adopt.3. Semi-closed-loop systemSemi-closed-loop system detects components installed in the middle of transmission parts, the indirect measurement of the location of the implementation of parts. It can only compensate for part of the components within the system loop error, and therefore its more accurate than the accuracy of closed-loop system is low, but its structure and debugging as compared with the closed-loop system is simple.Current production numerical control system are more companies and manufacturers, foreign companies such as Siemens of Germany, Japan, Fanuc, Inc.; domestic Everest companies such as China, the Beijing Aerospace CNC System Corporation, Huazhong CNC CNC high-grade corporate and Shenyang National Engineering Research Center. Select CNC systems are mainly based on numerical control after transformation to be achieved in a variety of precision machine tools, drive motor power and the user's requirements to determine. Fourth, the main steps CNC transformation1. Determination of rehabilitation programs(1) Mechanical and Electrical Repair transformation combined.Generally speaking, in need of transformation of electrical machines, are in need of mechanical repair. To determine repair requirements, scope and content; have to ascertain the electrical modification of the mechanical structure in need of transformation requirements and content; but also determine the transformation of electrical and mechanical repair, reconstruction staggered between the time requirements. Mechanical properties of intact are electrical transformation success.(2) the easier issues first, after the first partial overall. Determine the transformation step, the whole electrical part of the transformation should be divided into several sub-systems, the basic shape of various systems to be connected after the completion of the whole system work. In each subsystem, we should do first the less technical, workload the larger work, and then do a technical high, requiring fine work, can focus people's attention to key areas.(3) selection system under conditions of use. For the transformation of the object to determine its environment and conditions, which the selection of electrical system protection, anti-jamming, self-cooling and air filtering performance can provide the correct basis. Electrical system options must also be considered mature products, their performance should be reasonable and practical, there are spare parts to provide maintenance support, features a number of years to meetthe current and future development requirements.(4) The implementation and responsibilities of personnel involved in reconstruction.(5) The transformation of the determination of the scope and cycle.2. Transformation of the technical preparation(1) mechanical parts ready. In line with the transformation of mechanical electrical repairs should be completed in advance. The same time, be demolished and replaced and processing should be part of such advance planning is necessary to properly interface with the entire transformation.(2) The electrical information on the new system to digest.(3) The conversion of the old system interface design. According to the scope of each of the different equipment modification required to pre-designed interface, part of the conversion, if the entire transformation should be designed to convert mechanical and electrical interfaces, operation panel control and configuration, the Internet part of the contact, parameter measurement, the maintenance and so on. Require the operation and maintenance easy and reasonable, alignments, fluent, primary and secondary connection point less electrical interference with the strength of the smallest, with an appropriate margin and so on. Local transformation, but also need to consider the performance of the system match theold and new, the voltage polarity and size of change, the installation location, digital-analog conversion, etc., if necessary, need to create their own interfaces.(4) operation and programming staff technical training. ①training should cover the new control panel configuration, function and meaning of the instructions; ②the scope of the new system features, use, and the difference between the old system; ③maintenance requirements; ④programming standards and automated programming and more. Focused understood, grasp operating instructions and programming instructions.(5) Debugging steps and acceptance criteria for the determination. Debugging should be done by the project leader carried out with the others. Debugging step can be from simple to complex, from small to large, from outside to inside, you can also after the first local situation, the whole system after the first subsystem. The development of acceptance criteria must be realistic, too high or too low a standard will have a negative impact on the transformation.3. The implementation of reform(1) The overall maintenance of the machine. The long-term use of the original machine, you need to conduct a comprehensive maintenance. Secondly, the response to machine tools to make achange before the geometric accuracy, dimensional accuracy of measurement, and for the record. In this way pairs of reference to guide the transformation of the role, but also in the transformation of the end for comparison analysis.(2) to retain the electrical adjustment of some of the best. If the electrical system as part of the transformation, in turn, should retain the parts of the maintenance and optimization adjustments, such as high power part of the spare parts replacement, electrical maintenance, drying transformer insulation, pollution, cleaning, ventilation and cooling equipment cleaning, servo Drive optimization adjustments, update aging wires and cables, connectors and other fastening. Only the electrical part of the reservation and do excellent optimization adjustment, in order to ensure that transformed the machine tool have lower failure rates.(3) The original systems were dismantled. The removal of the original system must be controlled carefully to the original drawings in time to make mark in the drawings to prevent the omission or been demolished. In the process of demolition will find some of the new system design in the gaps, it is timely to add and correction. Removed the system should be properly safeguarded in case of unsuccessful reconstruction resume use. There is a definite value, and can be used for spare parts.(4) reasonable arrangements for the location and wiring the new system. Connection must be a clear division of labor, there is one person review the inspection to ensure that the connection process specifications, diameter suitable, correct, reliable and beautiful. (5) debugging. Debug must be pre-established procedures and requirements. Debugging the first to test the safety protection system sensitivity, personal and equipment to prevent accidents. Debugging the site must be clean; the moving coordinate extension units at the center of the whole trip; be able to load test, the first no-load after load; can simulate the experiment, the first real action after simulated; be manual, first manually and automatically.4. Acceptance and post-work(1) The mechanical properties of machine tool acceptance. Machine tool should meet the requirements of the mechanical properties, geometric accuracy should be within the limits prescribed.(2) The electrical control functions and control accuracy and acceptance. The various functions of electrical control actions must meet the normal, sensitive and reliable. Control precision application system itself functions (such as step size, etc.) and standard measuring apparatus (such as laser interferometer, coordinate measuring machine, etc.) control checks, to reach within a range. Should also be modified before the machine with the functions andaccuracy to make comparison, access to quantifiable indicators of difference.(3) The test piece cutting and acceptance. Can refer to the relevant domestic and international standards for CNC cutting specimens, in a qualified operator, the programmer with the trial under the cut. Specimen cutting machine tools can be acceptance of stiffness, cutting force, noise, motion trajectory, related actions, are generally not suitable for specimen use of a product part.(4), drawings, information and acceptance. Machine transformation finished, should be promptly drawings, data, transform the file summary, collate, transfer into the file. This is the future and stable operation of the equipment is very important.(5) Summary and improve.5, numerical examples of reconstruction1. Milling machine with the Siemens 810M transformation X53In 1998, the company invested 200,000 yuan, with Germany's Siemens 810M CNC system, 611A AC servo drive system on the company's X53 model of a milling machine to X, Y, Z three-axis numerical control transformation. Retained the original spindle system and cooling system. -Axis transformation of a ball screw used in the machinery and gear transmission mechanism. Thetransformation of work includes mechanical design, electrical design, PLC program preparation and debugging, machine tool repair, machine installation and debugging. After transformation, milling, processing and effective travel X, Y, Z axis respectively, 880mm, 270mm, 280mm; maximum speed of X, Y, Z axis respectively, 5 000mm/min, 1 500mm/min, 800mm/min; point moving speed of X, Y, Z axis respectively 3 000mm/min, 1 000mm/min, 500 mm / min; machining accuracy of ± 0.001 mm. Machine tools, coordinate linkage to be completed by a variety of complex curve or surface processing.2. GSK980T and stepper drive system with the transformation ofC6140 latheIn 1999, the company invested 8 million yuan, with Guangzhou CNC Equipment Factory production GSK980T numerical control system, DY3 hybrid stepper drive unit on the company's a longerC6140 lathe X, Z 2-axis transform. Retained the original spindle system and cooling system. Transformation of two-axis ball screw in the machinery used, and synchronous transmission. The transformation of work includes mechanical design, electrical design, machine overhaul and machine installation and debugging. Lathe After the transformation, processing and effective stroke X, Z axis respectively, 390mm, 1400mm; maximum speed X, Z axisrespectively, 1 200mm/min, 3 000mm/min; jog speed 400mm/min; point moving fast X, Z-axis respectively, 1 200mm/min, 3000mm/min; machine smallest mobile unit 0.001mm.6, numerical transformation of the issues and recommendations1. Transformation problems in NCCNC machine tools through several transformation and found work, there are also many problems, mainly reflected in: (a) The departments, developers uncertain functions, organizational chaos, a serious impact on progress in the transformation; (2) to develop the work process and plans are mostly developed rule of thumb, less reasonable; (3) the training of relevant personnel is not in place, resulting in machine tool technology officers will not be modified after programming, the operator of the machine operator unskilled and so on.2. Transformation of the proposed NC(1) is responsible for transformation of the staff responsibilities of clear penalties and rewards, fully mobilize the enthusiasm of the staff; train a batch of high-quality applications and maintenance personnel, training for selected officers to go out and learn the advanced technologies;(2) To focus on users, maintenance of CNC system of technicaltraining, the establishment of numerical control technology at home and abroad resource library. The establishment of technical data files, do the work of spare parts.分析数控机床改造为了我国民营企业的生存与发展,提高数控机床的速度是必要的。
数控技术编程设计外文文献翻译、中英文翻译、外文翻译
附录1 译文数控技术1 当前世界NC机床的研究现状世界各国对数控机床、加工中心以至FMS、CIMS等各种新技术的研究与发展进程,是与世界经济形势紧密相连的。
机床工业有世界经济相互促进和发展,进入21世界知识机警时代,人们的知识所起的作用更加突出,而机床工业作为机器制造业的基础,其重点地位与战略意义也更加明显。
在1991—1994年间,世界经济衰退,昂贵的FMS,CIMS降温,1995—2000年间,世界经济在低速增长,根据当前世界市场各方面用户为提高生产率对NC机床的要求以及世界四大国际机床展(欧洲的EMO、美国的IMTS、日本的JIMTOF、中国的CIMT)上展品的分析,当前世界NC机床的技术研究主要有以下几点:(1)更加重视新技术和创新在世界范围内,对新工艺、新材料、新结构、新单元、新元件的研究开发工作正在大力开展,如新的刀具材料、新的主轴结构、高速电主轴、高速直线电机等的开发研究。
以加工工艺的改进创新为基础,为加工超硬、难切削材料及特殊复合材料及复杂零件、不规则曲面等在不断研究开发新机种。
(2)提高机床加工的精度和研究为了提高加工中心的加工精度,不断提高机床的刚度、减少振动,消除热变形,降低噪声,提高NC机床的定位精度、重复精度、工作可靠性、稳定性、精度保持性,世界很多国家都在进行机床热误差、机床运动及负载变形误差的软件补偿技术研究,并采取精度补偿、软件补偿等措施加以改善,有的已经可以使此类误差消除60%。
并在不断开发精细加工,纳米加工。
(3)提高机床加工生产率的研究世界NC机床、加工中心及相应的高速点主轴、直线电机、测量系统、NC 系统的开发,均以提高生产率为前提。
2 加工中心的分类(1)按工艺用途分类有:镗铣加工中心,分为立式樘铣加工中心、卧式樘铣加工中心和龙门樘铣加工中心。
其加工工艺以樘铣为主,用于箱体,壳体以及各种复杂零件特殊曲线和曲面轮廓的多工序加工,适合多品种小批量生产。
复合加工中心,主要指五面复合加工,主轴头可自动回转,进行立,卧加工,在主轴自动回转后,在水平和垂直方向实现知道变换。
数控论文带英文版
数控论文带英文版第一篇:数控论文带英文版Development and maintenance of CNC1946 On the birth of the world's first electronic computer, which indicates that human beings created to enhance and replace the mental part of the tool.It is human in the agricultural, industrial society created a tool that is enhanced compared to manual qualitative leap, he entered the information society for human foundation.Half a century, and the core of computer-driven information technology, both through the TV, modern communications, improve the quality of human life, but also improve productivity fast forward, creating a history of human civilization, the production history of the era.The rapid development of information technology led directly to the arrival of the knowledge economy.In 1952, computer technology applied to the machine.Born in the United States first CNC machine puters and control technology in the application of machinery equipment manufacturing industry within the century's most significant technological advances.Since then, the conventional machine produced a qualitative change.Nearly half a century, has undergone two phases of CNC machine tools and the development of six generations.(1)Numerical control(NC)phase(1952-1970 years) early computing speed is low, which was affected scientific computing and data processing is not large, can not meet the requirements of real-time control machine tools.People have used digital logic circuits, “ride” into a dedicated computer as numerical control machine tool system, known as the hardware connection NC(HARD WIREDNC), referred to as NC(NC).With thedevelopment of components, at this stage after three generations, that in 1952 the first generationthe transistor;1965, the third generationpresent)In 1970, GM has a small computer and into mass production there.Its operation faster than the fifties and sixties have increased significantly, more than a special “ride” into a dedicated computer, low cost, high reliability.So it came as a CNC porting the core components, entered a computer numerical control(CNC)stage.By 1971, INTEL Corporation in the United States the world's first computer of the two core componentsthe microprocessor;1990, the sixth generationBASED).CNC system nearly five decades gone through two stages six generation of development, but development to the fifth generation only after a fundamental solution to the reliability is low, the price is extremely expensive, extremely convenient application is very critical issue.Thus, even in industrialized countries, large-scale numerical control system has been applied and popularity in the late seventies early eighties after the thing, that is numerical control technology after nearly three decades of development before wider application to.Abroad has been renamed as early as the computer numerical control(ie CNC), while China is still often called numerical control(NC).So we talk about everyday, “NC” in essence is that “computer numerical control” of C machine tool numerical control system is the core component, therefore, the maintenance of CNC machine tool numerical control system is mainly to maintain.After a NC system for a longer period of use, performance of electronic components to aging or damaged, and some mechanical parts especially, to try to extend the lifetime of components and parts wear cycle, to prevent all kinds of failures, particularly fatal accidents theoccurrence of the numerical control system must be routine maintenance.T o sum up, pay attention to the following aspects.1 NC system maintenance formulate rulesRegulations according to the characteristics of various components to determine their maintenance regulations.Expressly provided, such as what areas need cleaning every day(such as CNC system input / output unit-optical reading machines for cleaning, inspection is well-oiled machine structural parts, etc.), which parts should be regularly checked or replaced(such as brush DC servo motors and commutator should be checked once a month).(2)As less as possible open CNC ark and high voltage ark of the doorBecause in machining workshop in the air of general contain oil mist, dust and even metal powder.Once they fall within the NC system or electrical components on printed circuit, easily lead to decreased insulation resistance between components, and even lead to damage to components and printed circuits.Some users in the summer to make long-term work overload CNC system, CNC cabinet door open to heat, which is not desirable kind of approach will eventually lead to accelerated damage to the CNC system.The correct way is to reduce the numerical control system of the external ambient temperature.Therefore, there should be a strict requirement, unless the necessary adjustments and repairs, just open the doors is not allowed, but not allowed to open doors when in use.Regular cleaning the ark of the numerical control heat ventilation systemShould every day to check on the numerical control system each cooling fan is functioning properly, should inspect working environment condition, every half an year or quarterly review of a duct filter whether jam phenomenon.If excessive dust build-upInternet filter, the need for timely clean-up, otherwise it will cause the temperature inside the high numerical control system(generally not exceed 55 ℃), resulting in overheating or NC alarm system does not work reliably.4 CNC systems are often used to monitor voltage produced by FANUC CNC system, allowing the grid voltage rating of 85% to 110% of range fluctuations.If you exceed this range, it will cause the system not working properly, or even cause damage to electronic components within the NC system.5 periodic replacement of memory battery FANUC CNC production company within the system memory in two ways:(1)No batteries to keep the magnetic bubble memory.(2)the need to maintain the CMOS RAM with battery device is not powered on CNC system in order to maintain the contents of the storage period, with internal rechargeable battery to maintain the circuit, in the NC system is powered by the +5 V power supply through a diode to the CMOS RAM power, and can charge the rechargeable battery;cut off power when the numerical control system is replaced by a battery to maintain the information in CMOS RAM, under normal circumstances, even if the battery has not yet expired, the battery should be replaced once a year, in order to ensure that the system can work properly.In addition, we must note that the battery replacement should be carried out under the NC system power C long-term maintenance when not in numerical order to improve system utilization and reduce the numerical control system failure, CNC machine tools should be used at full capacity, and not long idle, for some reason, resulting in long idle CNC system, in order to numerical control system to avoid damage, please note the following two points:(1)should always power to the CNC system, especially in high humidity environment of therainy season and even more so, lock the machine does not move in the case(that is, the servo motor does not turn time), let dry run CNC e of electrical components to disperse their heat moisture within the NC system, to ensure stable and reliable performance of electronic devices, proved in the air humidity areas, power is to reduce the failure rate is often an effective measure.(2)CNC machine tool feed servo drives using DC and DC servo spindle drive, brush should be removed from the DC motor, so as not due to chemical corrosion, the commutator surface corrosion, resulting in change to the performance deterioration, and even entire motor damage.At present, the field of sheet metal stamping, CNC punching machine / CNC turret punch press with its fast, high precision machining, mold versatile, flexible products, etc., are widely er in choosing a quality mold, its use and maintenance of the level of direct impact to the workpiece machining quality and mold life.Mold control equipment is also an important part of operating costs.First,ensure the best mold clearanceMould clearance is to point to the punch into the next model, the sum of the clearance between the sides.It and thickness, material and the stamping process and suitable mould clearance, can guarantee good punching quality, reduce burr and collapse and keep the sheet metal level off, effectively prevent take material, prolong die life.Through the examination of stamping waste, we can determine whether appropriate mould clearance.If too much clearance waste will be rough rolling fractures and smaller light face.The greater the clearance, fractures and light the viewpoint of the formation of surface and the more they can form punching edge and fracture, appear even a thin rim bumps.Conversely, if the clearance is too small, waste will besmall Angle fractures and larger light face.When slot, step blunt, cutting local stamping, lateral force will make the punch deflection and cause unilateral gap is too small, sometimes edge migration will scratch lower die, causing the lower die quickly wear.Mould to best clearance stamping, waste of fractures and bright surface with the same Angle, and overlap each other, so that can make the cutting force minimum, punching the burr was very small.Second, timely grinding can effectively extend the life of the mold if too large of a workpiece or stamping burrs generated when abnormal noise may die passivation.Check the punch and the die, when its blade edges have a radius of approximately 0.10mm wear arc, it is necessary sharpening of.Practice has shown that frequent small amounts of sharpening rather than waiting until non-grinding mill can not be again when, not only to maintain good quality of the workpiece, reducing the blanking force, but die life can be extended more than doubled.In addition to knowing when to die grinding, the grinding master the correct method is especially important.Mold grinding procedure is as follows:1)grinding, it will punch a vertical grip on the surface grinder's magnetic chuck or fixture within the V-groove, each grinding capacity of 0.03 ~ 0.05mm, repeat until the punch grinding sharp, the maximum amount of grinding is generally 0.1 ~ 0.3mm.2)the use of sintered aluminum oxide grinding wheel, the hardness D ~ J, grit sizes 46 to 60, preferably for high-speed steel grinding wheel.3)When the grinding force or mold near the wheel, add coolant to prevent overheating and cracking the mold or annealing, should be required in accordance with the manufacturer of high quality multi-purpose coolant.4)The amount of feed wheel down 0.03 ~ 0.08 mm, lateral feed rate0.13 ~ 0.25 mm, lateral feed rate 2.5 ~ 3.8m/min.5)After grinding, oil stone polished edge, remove the burr, and grind the radius of 0.03 ~ 0.05 mm round, to prevent edge cracking.6)punch to the magnetic treatment and sprayed with oil to prevent rust.Third, the elimination and reduction of adhesive material way because when the pressure and heat stamping, sheet metal fine particles will bond to the surface of the punch, resulting in poor quality punching.Removal of binder used fine whetstone grinding, sanding should be directed to the direction of movement with the same punch, so the light will avoid the generation of further binder.Do not use gauze and other coarse grinding, to avoid the punch surface is more rough and more prone to sticky material.Reasonable die clearance, good stamping process, and the necessary lubrication sheet, will reduce the production of sticky material.Prevent overheating, the general lubrication of the way, this will reduce the friction.If you can not waste lubricating or rebound occurs, may take the following approach: alternate punch than the same size turns punching,Can make its repeated in before use have long cooling time.Overheating will use all die.Through the programming control changing mould, the interrupt their long time of repetition of work, or reduce its pressing frequency.Four, blunt is when the deformation of sheet metal porous to prevent measuresIf in a rush on board a porous, due to the accumulation of shear stress plank cannot maintain level.Every time punching, around the hole material will down deformation, causing the surface appears on the sheet metal tensile stress, and under the surface have compressive stress.For a small amount of punching, and its effect is not obvious, but when punching quantity is increased, the pull, compressive stress somewhere inaccumulation, until materials.Eliminate such deformation of a method is: to every one KongChong cut, and then returns to the rest of the punching holes.So although also can produce stress, but easing in the same direction order stamping of stress at accumulation, also can make the two groups before and after the stress of offset each other holes, so as to prevent the deformation of sheet metal.Five, try to avoid cutting through the narrow strip materialWhen the used for cutting width of less than in the process of sheet metal sheet thickness, lateral force for and make the punch to bending deformation, make side of the gap is too small or wear is intensified, serious scratch when the mould, make fluctuation mode and damage.Suggestions don't step blunt width of less than 2.5 times the thickness of the narrow a sheet metal sheet.Cutting through the narrow strip material, sheet metal tend to turn into the mode of open, and not be completely cut off, and even wedge dies profile.If can't avoid the above situation, the proposed use output slabs supported the role of the punch fully guided mold.Six, the punch surface hardening and the applicable scopeAlthough heat treatment and surface coating can improve the punch surface properties, but is not the solution to the problems and prolong die life is pressing the general method.Generally speaking, the coating surface hardness and improve the punch that side lubricity improved, but in large tonnage, hard materials stamping, these advantages in about 1000 times after stamping and disappeared.According to the following circumstance can use surface hardening the punch: Blunt soft or sticky materials(such as aluminum);Blunt thin non-abrasive materials(such as glass epoxypieces);Blunt thin hard material(such as stainless steel);Frequent point blunt;Abnormal lubrication.Surface hardening usually adopts of titanium coating and seepage nitrogen, method, its surface hardening layer thickness for 12 ~ 60 μ m molecular structure, it is a part of the matrix punch, and not only is the coating.Surface hardening of the mould can press usually way further.Through the surface hardening will lower mould in the stainless steel plate wear behavior, but can not prolong its service life, and the appropriate and timely lubrication, according to procedures, burrs, is the effective way.Seven, CNC turret punch die a neutral is bad for the overhaulIf a punch mould to neutral is bad, cause mould fast passivation, workpiece machining quality is poor, can the following maintenance: Check the level of the machine tool, when necessary to adjust;Check and lubrication of model hole on the wheel and the direction key, if there is damage timely repair;Clean the next mould seat, so as to lower die accurate installation, check and its key or the keyway wear and, when necessary, to change;Use the special mandrel calibration mould location, such as a deviation adjust in time.The contents of the situation is usually concerned, in view of the press and the concrete types die specifications are different, the user should combine the actual to know and summarizing the experience, and displays the best use of the mould performance.数控的发展及设备维护浅谈1946年诞生了世界上第一台电子计算机,这表明人类创造了可增强和部分代替脑力劳动的工具。
数控机床编程外文文献翻译、中英文翻译、外文翻译
英文原文CNC machine toolsWhile the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment.The first benefit offered by all forms of CNC machine tools is improved automation. The operator intervention related to producing work pieces can be reduced or eliminated. Many CNC machines can run unattended during their entire machining cycle, freeing the operator to do other tasks. This gives the CNC user several side benefits including reduced operator fatigue, fewer mistakes caused by human error, and consistent and predictable machining time for each workpiece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing workpieces with conventional machine tools.The second major benefit of CNC technology is consistent and accurate workpieces. Today's CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical workpieces can be easily produced with precision and consistency.A third benefit offered by most forms of CNC machine tools is flexibility. Since these machines are run from programs, running a different workpiece is almost as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since these machines are very easy to set up and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with today's just-in-time (JIT) product requirements.Motion control - the heart of CNCThe most basic function of any CNC machine is automatic, precise, and consistent motion control. Rather than applying completely mechanical devices to cause motion as is required on most conventional machine tools, CNC machines allow motion control in a revolutionary manner2 . All forms of CNC equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned along their lengths of travel. The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed commands. Generally speaking, the motion type (rapid, linear, and circular), the axes to move, the amount of motion and the motion rate (feedrate) are programmable with almost all CNC machine tools.A CNC command executed within the control tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw. And the ball screw drives t he linear axis (slide). A feedback device (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3.Though a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw on the vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis.How axis motion is commanded - understanding coordinate systems .It would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion amount4. (This would be like having to figure out how many turns of the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more logical way by utilizing some form of coordinate system. The two most popular coordinate systems used with CNC machines are the rectangular coordinate system and the polar coordinate system. By far, the more popular of these two is the rectangular coordinate system.The program zero point establishes the point of reference for motion commands in a CNC program. This allows the programmer to specify movements from a common location.If program zero is chosen wisely, usually coordinates needed for the program can be taken directly from the print.With this technique, if the programmer wishes the tool to be sent to a position one inch to the right of the program zero point, X1.0 is commanded. If the programmer wishes the tool to move to a position one inch above the program zero point, Y1.0 is commanded. The control will automatically determine how many times to rotate each axis drive motor and ball screw to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner.All discussions to this point assume that the absolute mode of programming is used. The most common CNC word used to designate the absolute mode is G90. In the absolute mode, the end points for all motions will be specified from the program zero point. For beginners, this is usually the best and easiest method of specifying end points for motion commands. However, there is another way of specifying end points for axis motion.In the incremental mode (commonly specified by G91), end points for motions are specified from the tool's current position, not from program zero. With this method of commanding motion, the programmer must always be asking "How far should I move the tool?" While there are times when the incremental mode can be very helpful, generally speaking, this is the more cumbersome and difficult method of specifying motion and beginners should concentrate on using the absolute mode.Be careful when making motion commands. Beginners have the tendency to think incrementa lly. If working in the absolute mode (as beginners should), the programmer should always be asking "To what position should the tool be moved?" This position is relative to program zero, NOT from the tools current position.Aside from making it very easy to determine the current position for any command, another benefit of working in the absolute mode has to do with mistakes made during motion commands.In the absolute mode, if a motion mistake is made in one command of the program, only one move ment will be incorrect. On the other hand, if a mistake is made during incremental movements, all motions from the point of the mistake will also be incorrect.Assigning program zeroKeep in mind that the CNC control must be told the location of the program zero point by one means or another. How this is done varies dramatically from one CNC machine and control to another8. One (older) method is to assign program zero in the program. With this method, the programmer tells the control how far it is from the program zero point to the starting position of the machine. This is commonly done with a G92 (or G50) command at least at the beginning of the program and possibly at the beginning of each tool.Another, newer and better way to assign program zero is through some form of offset. Refer to fig.4. Commonly machining center control manufacturers call offsets used to assign program zero fixture offsets. Turning center manufacturers commonly call offsets used to assign program zero for each tool geometry offsets.A flexible manufacturing cell (FMC) can be considered as a flexible manufacturing subsystem. The following differences exist between the FMC and the FMS:1. An FMC is not under the direct control of the central computer. Instead, instructions from the central computer are passed to the cell controller.2. The cell is limited in the number of part families it can manufacture.The following elements are normally found in an FMC: • Cell controller• Programmable logic controller (PLC) • More than one machine tool• A materials handling device (robot or pallet)The FMC executes fixed machining operations with parts flowing sequentially between operations.High speed machiningThe term High Speed Machining (HSM) commonly refers to end milling at high rotational speeds and high surface feeds. For instance, the routing of pockets in aluminum airframe sections with a very high material removal rate1. Over the past 60 years, HSM has been applied to a wide range of metallic and non-metallic workpiece materials, including the production of components with specific surface topography requirements and machining of materials with hardness of 50 HRC and above. With most steel components hardened to approximately 32-42 HRC, machining options currently include: Rough machining and semi-finishing of the material in its soft (annealed ) condition heat treatment to achieve the final required hardness = 63 HRC machining of electrode s and Electrical Discharge Machining (EDM) of specific parts of dies and moulds (specifically small radii and deep cavities with limited accessibility for metal cutting tools) finishing and super-finishing of cylindrical/flat/cavity surfaces with appropriate cemented carbide, cermet, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN)For many components, the production process involves a combination of these options and in the case of dies and moulds it also includes time consuming hand finishing. Consequently, production costs can be high and lead times excessive.It is typical in the die and mould industry to produce one or just a few tools of the same design. The process involves constant changes to the design, and because of these changes there is also a corresponding need for measuring and reverse engineering .The main criteria is the quality level of the die or mould regarding dimensional, geometric and surface accuracy. If the quality level after machining is poor and if it cannot meet the requirements, there will be a varying need of manual finishing work. This work produces satisfactory surface accuracy, but it always has a negative impact on the dimensional and geometric accuracy.One of the main aims for the die and mould industry has been, and still is, to reduce or eliminate the need for manual polishing and thus improve the quality and shorten the production costs and lead times.Main economical and technical factors for the development of HSM SurvivalThe ever increasing competition in the marketplace is continually setting new standards. The demands on time and cost efficiency is getting higher and higher. This has forced the development of new processes and production techniques to take place. HSM provides hope and solutions...MaterialsThe development of new, more difficult to machine materials has underlined the necessity to find new machining solutions. The aerospace industry has its heat resistant and stainless steel alloys. The automotive industry has different bimetal compositions, Compact Graphite Iron and an ever increasing volume of aluminum3. The die and mould industry mainly has to face the problem of machining high hardened tool steels, from roughing to finishing.QualityThe demand for higher component or product quality is the result of ever increasing competition. HSM, if applied correctly, offers a number of solutions in this area. Substitution of manual finishing is one example, which is especially important on dies and moulds or components with a complex 3D geometry.ProcessesThe demands on shorter throughput times via fewer setups and simplified flows (logistics) can in most cases, be solved by HSM. A typical target within the die and mould industry is to completely machine fully hardened small sized tools in one setup. Costly and time consuming EDM processes can also be reduced or eliminated with HSM.Design & developmentOne of the main tools in today's competition is to sell products on the value of novelty. The average product life cycle on cars today is 4 years, computers and accessories 1.5 years, hand phones 3 months... One of the prerequisites of this development of fast design changes and rapid product development time is the HSM technique.Complex productsThere is an increase of multi-functional surfaces on components, such as new design of turbine blades giving new and optimized functions and features. Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs haveto be finished via machining and preferably by HSM . There are also more and more examples of thin walled workpieces that have to be machined (medical equipment, electronics, products for defence, computer parts)Production equipmentThe strong development of cutting materials, holding tools, machine tools, controlsand especially CAD/CAM features and equipment, has opened possibilities that must be met with new production methods and techniques5.Definition of HSMSalomon's theory, "Machining with high cutting speeds..." on which, in 1931, took out a German patent, assumes that "at a certain cutting speed (5-10 times higher than in conventional machining), the chip removal temperature at the cutting edge will start to decrease..."Given the conclusion:" ... seems to give a chance to improve productivity in machining with conventional tools at high cutting speeds..."Modern research, unfortunately, has not been able to verify this theory totally. There is a relative decrease of the temperature at the cutting edge that starts at certain cutting speeds for different materials.The decrease is small for steel and cast iron. But larger for aluminum and other non-ferrous metals. The definition of HSM must be based on other factors.Given today's technology, "high speed" is generally accepted to mean surface speeds between 1 and 10 kilometers per minute or roughly 3 300 to 33 000 feet per minute. Speeds above10 km/min are in the ultra-high speed category, and are largely the realm of experimental metal cutting. Obviously, the spindle rotations required to achieve these surface cutting speeds are directly related to the diameter of the tools being used. One trend which is very evident today is the use of very large cutter diameters for these applications - and this has important implications for tool design.There are many opinions, many myths and many different ways to define HSM. Maintenance and troubleshootingMaintenance for a horizontal MCThe following is a list of required regular maintenance for a Horizontal Machining Center as shown in fig.5. Listed are the frequency of service, capacities, and type of fluids required. These required specifications must be followed in order to keep your machine in good working order and protect your warranty.DailyTop off coolant level every eight hour shift (especially during heavy TSC usage). Check way lube lubrication tank level. Clean chips from way covers and bottom pan. Clean chips from tool changer.Wipe spindle taper with a clean cloth rag and apply light oil. Weekly• Check for proper operation of auto drain on filter regulator.On machines with the TSC option, clean the chip basket on the coolant tank. Remove the tank cover and remove any sediment inside the tank. Be careful to disconnect the coolant pumpfrom the controller and POWER OFF the control before working on the coolant tank . Do this monthly for machines without the TSC option.Check air gauge/regulator for 85 psi.For machines with the TSC option, place a dab of grease on the V-flange of tools. Do this monthly for machines without the TSC option.Clean exterior surfaces with mild cleaner. DO NOT use solvents.Check the hydraulic counterbalance pressure according to the machine's specifications.Place a dab of grease on the outside edge of the fingers of the tool changer and run through all tools".MonthlyCheck oil level in gearbox. Add oil until oil begins dripping from over flow tube at bottom of sump tank.Clean pads on bottom of pallets.Clean the locating pads on the A-axis and the load station. This requires removing the pallet.• Inspect way covers for proper operation and lubricate with light oil, if necessary. Six monthsReplace coolant and thoroughly clean the coolant tank. Check all hoses and lubrication lines for cracking. Annually• Replace the gearbox oil. Drain the oil from the gearbox, and slowly refill it with 2 quarts of Mobil DTE 25 oil.• Check oil filter and clean out residue at bottom for the lubrication chart. Replace air filter on control box every 2 years.Mineral cutting oils will damage rubber based components throughout the machine. Troubles hootingThis section is intended for use in determining the solution to a known problem. Solutions given are intended to give the individual servicing the CNC a pattern to follow in, first, determining the problem's source and, second, solving the problem.Use common senseMany problems are easily overcome by correctly evaluating the situation. All machine operations are composed of a program, tools, and tooling. You must look at all three before blaming one as the fault area. If a bored hole is chattering because of an overextended boring bar, don't expect the machine to correct the fault.Don't suspect machine accuracy if the vise bends the part. Don't claim hole mis-positioning if you don't first center-drill the hole.Find the problem firstMany mechanics tear into things before they understand the problem, hoping that it will appear as they go. We know this from the fact that more than half of all warranty returned parts are in good working order. If the spindle doesn't turn, remember that the spindle is connected to the gear box, which is connected to the spindle motor, which is driven by the spindle drive, which is connected to the I/O BOARD, which is driven by the MOCON, which is driven by the processor.The moral here is don't replace the spindle drive if the belt is broken. Find the problem first; don't just replace the easiest part to get to.Don tinker with the machineThere are hundreds of parameters, wires, switches, etc., that you can change in this machine. Don't start randomly changing parts and parameters. Remember, there is a good chance that if you change something, you will incorrectly install it or break something else in the process6. Consider for a moment changing the processor's board. First, you have to download all parameters, remove a dozen connectors, replace the board, reconnect and reload, and if you make one mistake or bend one tiny pin it WON'T WORK. You always need to consider the risk of accidentally damaging the machine anytime you work on it. It is cheap insurance to double-check a suspect part before physically changing it. The less work you do on the machine the better.中文译文数控机床虽然各种数控机床的功能和应用各不相同,但它们有着共同的优点。
关于数控车床编程外文文献翻译中英文翻译外文翻译
关于数控车床编程外文文献翻译、中英文翻译、外文翻译英文原文On the NC latheCNC machine tool numerical control machine tools (Computer numerical control machine tools) abbreviation, is provided with a program control system of automatic machine tools. The logic control system can deal with the control code or other symbolic instruction specified program, and decoding the digital code, said information carrier, through the numerical control device input. After processing by CNC device control signals, control the machine movements, by drawing the shape and size requirements, will be automatically processed by the parts.Features: CNC machine tool operation and monitoring of all completed inthe numericalcontrol unit, it is the brain of CNC machine tools. Compared with the general machine tools, CNC machine tools has the following characteristics:● the processing object adaptability, adapt to the characteristics of mold products such as a single production, provide the appropriate processing method for die and mould manufacturing; ● high machining accuracy, processing with stable quality; ● can coordinate linkage, processing complex shape parts;● machining parts change, only need to change the program, can save the preparation time of production;● the machine itself high precision, rigidity, can choose the am ount of processing good, high productivity (3~5 times as common machine);The machine is a high degree of automation, reducing labor intensity;● conducive to the production management modernization. The use of CNC machine tools and the standard code of digital information processing, information transmission, the use of computer control method, has laid the foundation for the integration of computer aided design, manufacturing and management;● on the operators of higher quality, higher demands for the repair ofthe technical staff;● high reliability.Composition: CNC machine tools in general by the input medium, man-machine interactive equipment, CNC equipment, feed servo drive system, spindle servo drive system, the auxiliary control device, feedback apparatus and adaptive control device etc.. [4] in NC machining, NC milling processing is the most complex, need to solve most problems. NC programming of NC line in addition to CNC milling, cutting, CNC EDM, CNC lathe, CNC grinding, each with its own characteristics, servo system is the role of the motion signal is convertedinto the machine moving parts from the numerical control device of pulse. Concrete has the following parts: the structure of CNC machine tools.Driver: he is driving parts of CNC machine tools, actuator, including spindle drive unit, feeding unit, spindle motor and feed motor. He through the electric or electro-hydraulic servo system to realize the spindle and feeddrive under the control of numerical control device. When several feed linkage, can complete the positioning, processing line, plane curve and space curve.The main performance (1) the main dimensions. (2) the spindle system. (3) feed system. (4) tool system.(5) electrical. Including the main motor, servo motor specifications and power etc.. (6) cooling system. Including the cooling capacity, cooling pump output. (7) dimensions. Expressed as length * width * height.Development trend of CNC lathe:High speed, precision, complex, intelligent and green is the general trend in the development of CNC machine tool technology, in recent years, made gratifying achievements in practicality and industrialization. Mainly in the:1 machine tool composite technology to further expand with the CNC machine tool technology, composite processing technology matures, including milling - car compound, car millingcompound, car - boring - drill - gear cutting compound, composite grinding, forming, composite processing, precision and efficiency of machining isgreatly improved. \processing factory\the development of compound processing machine tool is the trend of diversified.Intelligent technology 2 CNC machine tools have a new breakthrough, in the performance of NC system has been reflected more. Such as: automaticallyadjust the interference anti-collision function, after the power of workpiece automatically exit safety power-off protection function, machining parts detection and automatic compensation function of learning, high precisionmachining parts intelligent parameter selection function, process automatic elimination of machine vibration functions into the practical stage, intelligent upgrade the function of machine and quality.The 3 robots enable flexible combination of flexible combination of higher efficiency of robot and the host are widely used, make flexible line more flexible, extending the function, flexible line shorten further, more efficient. Robot and machining center, milling composite machine, grinder, gear processing machine tool, tool grinding machine, electric machine, sawing machine, punching machine, laser cutting machine, water cutting machine etc. various forms of flexible unit and flexible production line has already begun the application.4 precision machining technology has the machining precision of CNC metal cutting machine tools from the yarn in the original (0.01mm) up to micronlevel (0.001mm), some varieties has reached about 0.05 μ M. Micro cutting and grinding machining of ultra precision CNC machine tools, precision can reach about 0.05 μ m, shape precision can reach about 0.01 μ M. Special processing precision by using optical, electrical, chemical, energy can reach nanometer level (0.001 μ m). By optimizing the design of machine tool structure, machine tool parts of ultra precision machining and precision assembly, using high precision closed loop control andtemperature, vibration and other dynamic error compensation technology, improve the geometric accuracy of machine tool processing, reduce the shape of error, surface roughness, and into the submicron, nano super finishing tiThe 5 functional component to improve the performance of functional components are at a high speed, high precision, high power and intelligent direction, and obtain the mature application. A full digital AC servo motor and drive device, high technology content of the electric spindle, linear motor, torque motor, linear motion components with high performance, application of high precision spindle unit and other function parts, greatly improving the technical level of CNC machine tools.The feed drive system of CNC lathe: Effect of feed drive system,The feed drive system of CNC machine tools will be received pulse command issued by the numerical control system, and the amplification and conversion machine movements carry the expected movement.Two, the feeding transmission system requirementsIn order to guarantee the machining accuracy of NC machine tool is high,the feed drive system of transmission accuracy, sensitivity high (fast response), stable work, high stiffness and friction and inertia small, service life, and can remove the transmission gap. Category three, feed drive system 1, stepping motor servo system Generally used for NC machine tools. 2, DC servo motor servo systemPower is stable, but because of the brush, the wear resulting in use needto change. Generally used for middle-grade CNC machine tools. 3, AC servomotor servo systemThe application is extremely widespread, mainly used in high-end CNC machine tools. 4, the linear motor servo systemNo intermediate transmission chain, high precision, the feed speed, no length limit; but the poor heat dissipation, protection requirements are particularly high, mainly used for high-speed machine.Driving component four, feed system 1, the ball screw nut pairNC machining, the rotary motion into linear motion, so the use of screwnut transmissionmechanism. NC machine tools are commonly used on the ball screw, as shownin Figure 1-25, it can be a sliding friction into rolling friction, meet the basic requirements of the feed system to reduce friction. The transmissionside of high efficiency, small friction, and can eliminate the gap, no reverse air travel; but the manufacturing cost is high, can not lock, size is not too big, generally used for linear feed in small CNC machine tool. 2, rotary tableIn order to expand the scope of the process of NC machine tools, CNC machine tools in addition to make linear feed along the X, Y, Z three coordinate axes, often also need a circumferential feed movement around Y or Z axis. Circular feed motion of CNC machine tools in general by the rotary table to realize, for machining center, rotary table has become an indispensablepart of. Rotary table of commonly used CNC machine tools in the indexing table and NC rotary table. (1) indexing tableIndexing table can only finish dividing movement, not circular feed, it is in accordance with the instructions in the NC system, when indexing will work together with the workpiece rotation angle. When indexing can also use manual indexing. Provisions of indexing table is generally only rotary angle (such as 90, 60 and 45 degree). (2) NC rotary tableNC rotary table appearance similar to the indexing table, but the internal structure and function is not the same. The main function of the NC rotary table is based on the numerical control device sends command pulse signal, complete circumferential feed movement, various arc processing and surface processing, it can also be graduation work. 3, guideRail is an important part of feed drive system, is one of the basic elements of the structure of machine tool, rigidity, precision and accuracy of NC machine tool which determines to a large extent retention. At present, guide the NC machine tool are sliding rail, rolling guideway and hydrostatic guideway. (1) sliding guideSliding guide rail has the advantages of simple structure, easy manufacture, good stiffness, vibration resistance and high performance, widely used in CNC machine tools, the use of most metal plastic form, known as the plastic guide rail, as shown in figure 1-26.On characteristics of the plastic sliding guide: friction characteristicis good, good wear resistance, stable movement, good manufacturability, low speed. (2) rolling guideRolling guide is placed in the rail surface between the ball, roller or needle roller, roller, the rolling friction instead of sliding surface of the guide rail between wipe.Rolling guide rail and the sliding rail, high sensitivity, small friction coefficient, and the dynamic, static friction coefficient is very small, so the motion is uniform, especially in the low speed movement, the stick-slip phenomenon is not easy to occur; high positioning accuracy,repeatability positioning accuracy is up to 0.2 μ m; traction force is small, wear small, portable in movement; good precision, long service life. But the vibration of rolling guide, high requirements on protection, complicated structure, difficult manufacture, high cost.Automatic tool changer:One, the function of automatic tool changerAutomatic tool changing device can help save the auxiliary time of CNC machine tools, and meet in an installation completed procedure, stepprocessing requirements. Two, on the requirement of automatic tool changerNumerical control machine tool for automatic tool changer requirement is: tool change quickly, time is short, high repetitive positioning accuracy, tool storage capacity is sufficient, small occupation space, stable and reliable work. Three, change the knife form 1, rotary cutter replacementIts structure is similar to the ordinary lathe turret saddle, according to the processing of different objects can be designed into square or six angle form, consists of the NC system sends out the instruction to the rotary cutter.2, the replacement of the spindle head tool changeThe spindle head pre-loaded required tools, in order to machining position, the main motor is switched on, drives the cutter to rotate. The advantage of this method is that eliminates the need for automatic clamping, cutting tool, clamping and cutting tool moving and a series of complex operation, reducetool change time, improve The ATC reliability. 3, the use of changing toolThe processing required tools are respectively arranged in the standard tool, adjust the size of the machine after certain way add to the knife, the exchange device from the knife and the spindle take knife switch.感谢您的阅读,祝您生活愉快。
(数控加工)机械类数控外文翻译外文文献英文文献数控精编
(数控加工)机械类数控外文翻译外文文献英文文献数控NumericalControlOneofthemostfundamentalconceptsintheareaofadvancedmanufactur ingtechnologiesisnumericalcontrol(NC).PriortotheadventofNC,allmachine toolsweremanualoperatedandcontrolled.Amongthemanylimitationsassoc iatedwithmanualcontrolmachinetools,perhapsnoneismoreprominentthan thelimitationofoperatorskills.Withmanualcontrol,thequalityoftheproducti sdirectlyrelatedtoandlimitedtotheskillsoftheoperator.Numericalcontrolrep resentsthefirstmajorstepawayfromhumancontrolofmachinetools.Numericalcontrolmeansthecontrolofmachinetoolsandothermanufact uringsystemsthoughtheuseofprerecorded,writtensymbolicinstructions.Ra therthanoperatingamachinetool,anNCtechnicianwritesaprogramthatissue soperationalinstructionstothemachinetool,Foramachinetooltobenumeric allycontrolled,itmustbeinterfacedwithadeviceforacceptinganddecodingth ep2ogrammedinstructions,knownasareader.Numericalcontrolwasdevelopedtoovercomethelimitationofhumanop erator,andithasdoneso.Numericalcontrolmachinesaremoreaccuratethanm anuallyoperatedmachines,theycanproducepartsmoreuniformly,theyarefas ter,andthelong-runtoolingcostsarelower.ThedevelopmentofNCledtothede velopmentofseveralotherinnovationsinmanufacturingtechnology:1.Electricaldischargemachining.sercutting.3.Electronbeamwelding.Numericalcontrolhasalsomademachinetoolsmoreversatilethantheirmanuallyoperatedpredecessors.AnNCmachinetoolcanautomaticallyproduc eawidevarietyofpar4s,eachinvolvinganassortmentofundertaketheproducti onofproductsthatwouldnothavebeenfeasiblefromaneconomicperspective usingmanuallycontrolledmachinetoolsandprocesses.Likesomanyadvancedtechnologies,NCwasborninthelaboratoriesofthe MassachusettsInstituteofTechnology.TheconceptofNCwasdevelopedinthe early1950swithfundingprovidedbytheU.SAirForce.Initsearlieststages,NCm achineswereabletomakestraightcutsefficientlyandeffectively.However,curvedpathswereaproblembecausethemachinetoolhadtobe programmedtoundertakeaseriesofhorizontalandverticalstepstoproducea curve.Theshorteristhestraightlinesmakingupthestep,thesmootheris4hecu rve.Eachlinesegmentinthestepshadtobecalculated.Thisproblemledtothedevelopmentin1959oftheAutomaticallyProgram medTools(APT)languageforNCthatusesstatementssimilartoEnglishlangua getodefinethepartgeometry,describethecuttingtoolconfiguration,andspe cifythenecessarymotions.ThedevelopmentoftheAPTlanguagewasamajors tepforwardinthefurtherdevelopmentofNCtechnology.TheoriginalNCsyste mwerevastlydifferentfromthoseusedpunchedpaper,whichwaslatertorepla cedbymagneticplastictape.Atapereaderwasusedtointerprettheinstruction swrittenonthetapeforthemachine.Together,all/fthisrepresentedgiantstepf orwardinthecontrolofmachinetools.However,therewereanumberofproble mswithNCatthispointinitsdevelopment.Amajorproblemwasthefragilityofthepunchedpapertapemedium.Itwas commonforthepapercontainingtheprogrammedinstructionstobreakortea rduringamachiningprocess,Thisproblemwasexacerbatedbythefactthateac hsuccessivetimeapartwasproducedonamachinetool,thepapertapecarryin gtheprogrammedinstructionshadtorerunthoughtthereader.Ifitwasnecessa rytoproduce100copiesofagivenpart,itwasalsonecessarytorunthepapertap ethoughtthereader100separatetimes.Fragilepapertapessimplycouldnotwi thstandtherigorsofshopfloorenvironmentandthiskindofrepeateduse.Thisledtothedevelopmentofaspecialmagnetictape.Whereasthepapert apecarriedtheprogrammedinstructionsasaseriesofholespunchedinthetap e,theThismostimportantofthesewasthatitwasdifficultorimpossibletochang etheinstructionsenteredonthetape.Tomakeeventhemostminoradjustment sinaprogramofinstructions,itwasnecessarytointerruptmachiningoperation sandmakeanewtape.Itwasalsostillnecessarytorunthetapethoughtthereade rasmanytimesastherewerepartstobeproduced.Fortunately,computertechn ologybecomearealityandsoonsolvedtheproblemsofNC,associatedwithpun chedpaperandplastictape.Thedevelopmentofaconceptknownasnumericalcontrol(DNC)solvethe paperandplastictapeproblemsassociatedwithnumericalcontrolbysimplyeli minatingtapeasthemediumforcarryingtheprogrammedinstructions.Indire ctnumericalcontrol,machinetoolsaretied,viaadatatransmissionlink,toahost computerandfedtothemachinetoolasneededviathedatatransmissionlinkage.Directnumericalcontrolrepresentedamajorstepforwardoverpunchedta peandplastictape.However,itissubjecttothesamelimitationasalltechnologi esthatdependonahostcomputer.Whenthehostcomputergoesdown,thema chinetoolsalsoexperiencedowntime.Thisproblemledtothedevelopmentofc omputernumericalcontrol.Thedevelopmentofthemicroprocessorallowedforthedevelopmentofpr ogrammablelogiccontrollers(PLC)andmicrocomputers.Thesetwotechnolo giesallowedforthedevelopmentofcomputernumericalcontrol(CNC).WithC NC,eachmachinetoolhasaPLCoramicrocomputerthatservesthesamepurpo se.Thisallowsprogramstobeinputandstoredateachindividualmachinetool. CNCsolvedtheproblemsassociateddowntimeofthehostcomputer,butitintr oducedanotherproblemknownasdatamanagement.Thesameprogrammig htbeloadedontendifferentmicrocomputerswithnocommunicationamongt hem.Thisproblemisintheprocessofbeingsolvedbylocalareanetworksthatco nnectDigitalSignalProcessorsTherearenumeroussituationswhereanalogsignalstobeprocessedinma nyways,likefilteringandspectralanalysis,Designinganaloghardwaretoperfo rmthesefunctionsispossiblebuthasbecomelessandpractical,duetoincrease dperformancerequirements,flexibilityneeds,andtheneedtocutdownondev elopment/testingtime.Itisinotherwordsdifficultpmdesignanaloghardware analysisofsignals.Theactofsamplingansignalintothehatarespecialisedforembeddedsignalprocessingoperations,andsuchaprocessoriscalledaDSP,whichstandsforDi gitalSignalProcessor.TodaytherearehundredsofDSPfamiliesfromasmanym anufacturers,eachonedesignedforaparticularprice/performance/usagegro up.Manyofthelargestmanufacturers,likeTexasInstrumentsandMotorola,off erbothspecialisedDSP’sforcertainfieldslikemotor-controlormodems,and generalhigh-performanceDSP’sthatcanperformbroadrangesofprocessin gtasks.Developmentkitsan`softwarearealsoavailable,andtherearecompani esmakingsoftwaredevelopmenttoolsforDSP’sthatallowstheprogrammer toimplementcomplexprocessingalgorithmsusingsimple“drag‘n’drop ”methodologies.DSP’smoreorlessfallintotwocategoriesdependingontheunderlyingar chitecture-fixed-pointandfloating-point.Thefixed-pointdevicesgenerallyo perateon16-bitwords,whilethefloating-pointdevicesoperateon32-40bitsfl oating-pointwords.Needlesstosay,thefixed-pointdevicesaregenerallychea per.Anotherimportantarchitecturaldifferenceisthatfixed-pointprocessorst endtohaveanaccumulatorarchitec ture,withonlyone“generalpurpose”re gister,makingthemquitetrickytoprogramandmoreimportantly,makingC-c ompilersinherentlyinefficient.Floating-pointDSP’sbehavemorelikecomm ongeneral-purposeCPU’s,withregister-files.TherearethousandsofdifferentDSP’sonthemarket,an ditisdifficulttask findingthemostsuitableDSPforaproject.Thebestwayisprobablytosetupaco nstraintandwishlist,andtrytocomparetheprocessorsfromthebiggestmanufacturersagainstit.The“bigfour”manufacturersofDSPs:TexasInstruments,Motorola,AT &TandAnalogDevices.Digital-to-analogconversionInthecaseofMPEG-Audiodecoding,digitalcompresseddataisfedintoth eDSPwhichperformsthedecoding,thenthedecodedsampleshavetobeconv ertedbackintotheanalogdomain,andtheresultingsignalfedanamplifierorsi milaraudioequipment.Thisdigitaltoanalogconversion(DCA)isperformedby acircuitwiththesamename&DifferentDCA’sprovidedifferentperformance andquality,asmeasuredbyTHD(Totalharmonicdistortion),numberofbits,lin earity,speed,filtercharacteristicsandotherthings.TheTMS320familyDQPofTexasInstrumentsTheTLS320familyconsistsoffixed-point,floating-point,multiprocessor digitalsignalprocessors(D[Ps),andfoxed-pointDSPcontrollers.TMS320DSP haveanarchitecturedesignedspecificallyforreal-timesignalprocessing.The ’F/C240isanumberofthe’C2000DSPplatform,andisoptimizedforcontro la pplications.The’C24xseriesofDSPcontrollerscombinesthisreal-timeproce ssingcapabilitywithcontrollerperipheralstocreateanidealsolutionforcontro lsystemapplications.ThefollowingcharacteristicsmaketheTMS320familyth erightchoiceforawiderangeofprocessingapplications:---Veryflexibleinstructionset---Inherentoperationalflexibility---High-speedperformance---Innovativeparallelarchitecture---CosteffectivenessDeviceswithinagenerationoftheTMS320familyhavethesameCPUstruc turebutdifferenton-chipmemoryandperipheralconfigurations.Spin-offdev icesusenewcombinationsofOn-chipmemoryandperipheralstosatisfyawide rangeofneedsintheworldwideelectronicsmarket.Byintegratingmemoryand peripheralsontoasinglechip,TMS320devicesreducesystemcostsandsavecir cuitboardspace.The16-bit,fixed-point DSPcoreofthe‘C24xdevicesprovidesanalogde signersadigitalsolutionthatdoesnotsacrificetheprecisionandperformance oftheirsystemperformancecanbeenhancedthroughtheuseofadvancedcont rolalgorithmsfortechniquessuchasadaptivecontrol,Kalmanfiltering,andsta tecontrol.The‘C24xDSPcontrollerofferreliabilityandprogrammability.Anal ogcontrolsystems,ontheotherhand,arehardwiredsolutionsandcanexperien ceperformancedegradationduetoaging,componenttolerance,anddrift.Thehigh-speedcentralprocessingunit(CPU)allowsthedigitaldesignert oprocessalgorithmsinrealtimeratherthanapproximateresultswithlook-upt ables.TheinstructionsetoftheseDSPcontrollers,whichincorporatesbothsign alprocessinginstructionsandgeneral-purposecontrolfunctions,coupledwit htheextensivedevelopmenttimeandprovidesthesameeaseofuseastradition al8-and16-bitmicrocontrollers.Theinstructionsetalsoallowsyoutoretainyoursoftwareinvestmentwhenmovingfromothergeneral-purpose‘C2xxgen eration,sourcecodecompatiblewiththe’C2xgeneration,andupwardlysour cecodecompatiblewiththe‘C5xgenerationofDSPsfro mTexasInstruments.The‘C24xarchitectureisalsowell-suitedforprocessingcontrolsignals.I tusesa16-bitwordlengthalongwith32-bitregistersforstoringintermediatere sults,andhastwohardwareshiftersavailabletoscalenumbersindependentlyo ftheCPU.Thiscombinationminimizesquantizationandtruncationerrors,andi ncreasesp2ocessingpowerforadditionalfunctions.Suchfunctionsmightincl udeanotchfilterthatcouldcancelmechanicalresonancesinasystemoranesti mationtechniquethatcouldeliminatestatesensorsinasystem.The‘C24xDSPcontrollerstakeadva ntageofansetofperipheralfunction sthatallowTexasInstrumentstoquicklyconfigurevariousseriesmembersfordi fferentprice/performancepointsorforapplicationoptimization.Thislibraryofbothdigitalandmixed-signalperipheralsincludes:---Timers---Serialcommunicationsports(SCI,SPI)---Analog-to-digitalconverters(ADC)---Eventmanager---Systemprotection,suchaslow-voltageandwatchdogtimerTheDSPcontrollerperipherallibraryiscontinuallygrowingandchanging tosuittheoftomorrow’sembeddedcontrolmarketplace.TheTMS320F/C240isthefirs tstandarddeviceintroducedinthe‘24xseriesofDSPcontrollers.Itsetsthestandardforasingle-chipdigitalmotorcontrolle r.The‘240canexecute20MIPS.Almostallinstructionsareexecutedinasimple cycleof50ns.Thishighperformanceallowsreal-timeexecutionofverycomple 8controlalgorithms,suchasadaptivecontrolandKalmanfilters.Veryhighsam plingratescanalsobeusedtominimizeloopdelays.The‘240hasthearchitecturalfeaturesnecessaryforhigh-speedsignalp rocessinganddigitalcontrolfunctions,andithastheperipheralsneededtopro videasingle-chipsolutio nformotorcontrolapplications.The‘240ismanufac turedusingsubmicronCMOStechnology,achievingalogpowerdissipationrat ing.Alsoincludedareseveralpower-downmodesforfurtherpowersavings.So meapplicationsthatbenefitfromtheadvancedprocessingpowerofthe‘240i nclude:---Industrialmotordrives---Powerinvertersandcontrollers---Automotivesystems,suchaselectronicpowersteering,antilockbrake s,andclimatecontrol---ApplianceandHVACblower/compressormotorcontrols---Printers,copiers,andotherofficeproducts---Tapedrives,magneticopticaldrives,andothermassstorageproducts ---RoboticandCNCmillingmachinesTofunctionasasystemmanager,aDSPmusthaverobuston-chipI/Oando therperipherals.Theeventmanagerofthe‘240isunlikeanyotheravailableonaDSP.Thisapplication-optimizedperipheralunit,coupledwiththehighperfor manceDSPcore,enablestheuseofadvancedcontroltechniquesforhigh-preci sionandhigh-efficiencyfullvariable-speedcontrolofallmotortypes.Includei ntheeventmanagerarespecialpulse-widthmodulation(PWM)generationfu nctions,suchasaprogrammabledead-bandfunctionandaspacevectorPWMs tatemachinefor3-phasemotorsthatprovidesstate-of-the-artmaximumeffic iencyintheswitchingofpowertransistors.Thereindependentupdowntimers,eachwithit’sowncompareregister, supportthegenerationofasymmetric(noncentered)aswellassymmetric(cen tered)PWMwaveforms.Open-LoopandClosed-LoopControlOpen-loopControlSystemsThewordautomaticimpliesthatthereisacertainamountofsophisticatio ninthecontrolsystem.Byautomatic,itgenerallymeansThatthesystemisusuall ycapableofadaptingtoavarietyofoperatingconditionsandisabletorespondt oaclassofinputssatisfactorily.However,notanytypeofcontrolsystemhasthea ually,theautomaticfeatureisachievedbyfeed.gthefeedbackstructure,itiscalledanopen-loopsystem,whichisthesimp lestandmosteconomicaltypeofcontrolsystem.inaccuracyliesinthefactthato nemaynotknowtheexactcharacteristicsofthefurther,whichhasadefinitebea ringontheindoortemperature.Thisalcopointstoanimportantdisadvantageo ftheperformanceofanopen-loopcontrolsystem,inthatthesystemisnotcapableofadaptingtovariationsinenvironmentalconitionsortoexternaldisturban ces.Inthecaseofthefurnacecontrol,perhapsanexperiencedpersoncanprovi decontrolforacertaindesiredtemperatureinthehouse;butidthedoorsorwin dowsareopenedorclosedintermittentlyduringtheoperatingperiod,thefinal temperatureinsidethehousewillnotbeaccuratelyregulatedbytheopen-loop control.Anelectricwashingmachineisanothertypicalexampleofanopen-loops ystem,becausetheamountofwashtimeisentirelydeterminedbythejudgmen tandestimationofthehumanoperator.Atrueautomaticelectricwashingmach ineshouldhavethemeansofcheckingthecleanlinessoftheclothescontinuous lyandturnitsedtoffwhenthedesireddegisedofcleanlinessisreached.Closed-LoopControlSystemsWhatismissingintheopen-loopcontrolsystemformoreaccurateandmo readaptablecontrolisalinkorfeedbackfromtheoutputtotheinputofthesyste m.Inordertoobtainmoreaccuratebontrol,thecontrolledsignalc(t)mustbefe dbackandcomparedwiththereferenceinput,andanactuatingsignalproporti onaltothedifferenceoftheoutputandtheinputmustbesentthroughthesyste mtocorrecttheerror.Asystemwithoneormorefeedbackpat(slikethatjustdesc ribediscalledaclosed-loopsystem.humanbeingareprobablythemostcompl exandsophisticatedfeedbackcontrolsysteminexistence.Ahumanbeingmay beconsideredtobeacontrolsystemwithmanyinputsandoutputs,capableofc arryingouthighlycomplexoperations.Toillustratethehumanbeingasafeedbackcontrolsystem,letusconsidert hattheobjectiveistoreachforanobjectonaperformthetask.Theeyesserveasa sensingdevicewhichfeedsbackcontinuouslythepositionofthehand.Thedist ancebetweenthehandandtheobjectistheerror,whichiseventuallybroughtto zeroasthehandreachertheobject.Thisisatypicalexampleofclosed-loopcontr ol.However,ifoneistoldtoreachfortheobjectandthenisblindolded,onecano nlyreachtowardtheobjectbyestimatingitsexactposition.ItisAsantherillustra tiveexampleofaclosed-loopcontrolsystem,showstheblockdiagramoftheru ddercontrolsystemofThebasicalementsandtheblocadiagramofaclosed-loo pcontrolsystemareshowninfig.Ingeneral,theconfigurationofafeedbackcon trolsystemmaynotbeconstrainedtothatoffig&.Incomplexsystemstheremay bemultitudeoffeedbackloopsandelementblocks.数控在先进制造技术领域最根本的观念之壹是数控(NC)。
中英文中英文文献翻译-数控切削技术综述
CNC Cutting Technology ReviewNumerical control high speed cutting technology (High Speed Machining, HSM, or High Speed Cutting, HSC), is one of the advanced manufacturing technology to improve the machining efficiency and quality, the study of related technology has become an important research direction of advanced manufacturing technology at home and abroad. China is a big manufacturing country, in the world of industry transfer to accept the front instead of back-end of the transfer, to master the core technology of advanced manufacturing, or in a new round of international industrial structure adjustment, our country manufacturing industry will further behind. Imminent research on the theory and application of advanced technology.1, high-speed CNC machining meaningHigh speed cutting theory put forward by the German physicist Carl.J.Salomon in the last century and early thirty's. He concluded by a lot of experiments: in the normal range of cutting speed, cutting speed if the increase, will cause the cutting temperature rise, exacerbating the wear of cutting tool; however, when the cutting speed is increased to a certain value, as long as more than the inflection point, with the increase of the cutting speed, cutting temperature can not rise, but will decline, so as long as the cutting speed is high enough, it can be solved very well in high cutting temperature caused by tool wear is not conducive to the cutting problem, obtained good processing efficiency.With the development of manufacturing industry, this theory is gradually paid more attention to, and attracted a lot of attention, on the basis of this theory has gradually formed the field of high-speed cutting technology of NC, relatively early research on NC High-speed Machining Technology in developed countries, through the theoretical basis of the research, basic research and applied research and development application, at present applications have entered the substantive stage in some areas.The high-speed cutting processing category, generally have the following several kinds of classification methods, one is to see that cutting speed, cutting speed over conventional cutting speed is 5-10 times of high speed cutting. Also has the scholar to spindle speed as the definition of high-speed processing standards, that the spindle speed is higher than that of 8000r\/min for high speed machining. And from the machine tool spindle design point of view, with the product of DN diameter of spindle and spindle speed, if the value of DN to (5~2000) * 105mm.r\/min, is considered to be of high speed machining. In practice, different processing methods, different materials, high speed cutting speed corresponding to different. Is generally believed that the turning speed of (700~7000) m\/min, milling speed reaches m\/min (300~6000), that is in the high-speed cutting.In addition, from the practical considerations, high-speed machining concept not only contains the high speed cutting process, integration and optimization also contains the process of cutting, is a can obtain good economic benefits and high speed, is the unity of technology and benefit.High-speed cutting technology is in the machine tool structure and materials, machine tool design, manufacturing technology, high-speed spindle system, high performance and fast feeding system, a high performance CNC system, tool holder system, high performance tool material and tool design and manufacturing technology, high efficiency and high precision measurement and testing technology, the mechanism of high speed cutting, high speed cutting process and other related hardware and software technology are fully integrated into the development foundation. Therefore, high speed cutting technology is a complex system engineering, is a with the related technology development and the development of the concept of.2, the superiority of high-speed CNC machiningDue to the large amplitude of the increase of the cutting speed, high speed machining technology not only improves the cutting productivity, and compared with the conventional cutting also has some obvious advantages: first, small cutting force: in high speed milling, cutting adopts the form of small quantities, high cutting speed, the cutting force is reduced by 30% compared to the conventional cutting, especially the radial cutting force greatly spindle bearing, tool, workpiece is reduced. Both to reduce tool wear, and effective control of the vibration machining system, improve the machining accuracy. Second, the material removal rate is high: the use of high speed cutting, cutting speed and feed rate are improved greatly, the same time the material removal rate is improved greatly. Thus greatly improve the processing efficiency. Third, thermal deformation small: in the high-speed cutting, cutting heat, most of the time to the work piece by the outflow of high-speed chip away, so the heating time of the machined surface is short, not because of the temperature rise leads to thermal deformation, is helpful to improve the surface accuracy, physical and mechanical properties of the machined surface processing method is better than the common. Fourth, high precision machining: high speed cutting usually feed is relatively small, so that the machined surface roughness is greatly reduced, at the same time as the cutting force is smaller than the conventional vibration cutting, machining system is reduced, the machining process more smoothly, so that good quality, can realize high accuracy, low degree of rough machining. Fifth, the green environmental protection: when high speed cutting, workpiece machining time is shortened, the use of energy and equipment rate, high processing efficiency, low processing energy consumption, at the same time, due to the high speed cutting can be achieved even without dry cutting, reduce the cutting fluid, reduce pollution and consumption.Research and application of numerical control high speed cutting technology, 3In view of the above characteristics of high speed machining, the technology has great application potential in the field of traditional processing weak. First of all, the workpiece for thin-wall parts and slender, uses the high-speed cutting, the cutting force is significantly reduced, the heat is chipping away, can be very good for using the traditional method of the deformation problem caused due to the influence of cutting force and cutting heat, greatly improving the processing quality. Secondly, because of the cutting resistance is small, to reduce tool wear, materials of highmanganese steel, hardened steel, austenitic stainless steel, composite materials, wear-resistant cast iron is difficult to be processed by traditional methods, can be studied using numerical control high speed cutting technology to process. In addition, in the automotive, aerospace, mold, manufacturing field, some integral components require relatively large material removal rate, the feed speed CNC high speed cutting with the cutting speed increase and the corresponding increase in unit time, so that the material removal rate is greatly improved, thus in the mold manufacturing, automobile manufacturing, aerospace manufacturing application of numerical control high speed cutting technology, will produce the enormous economic benefits. Fourth, because of the high-speed cutting, machining process is stable, the vibration is small, compared with the conventional cutting, high speed cutting can significantly improve the precision of 1~2, can be cancelled completely finishing, and subsequent, adopt numerical control high speed cutting technology, can achieve and rough, finishing on the overall structure of complex parts in a machine, reduces the likelihood of locating error transfer process, which is also conducive to improve the machining accuracy. Therefore, high speed cutting technology has a wide application prospect in precision manufacturing. Aluminium mould such as a business process, the mold cavity length is 1500mm, the required size error of ±0.05mm, surface roughness Ra0.8 μm, manufacturing process the original: rough planing - semi finish planing - finishing - Manual scraping - manual polishing, manufacturing cycle is 60 hours. Using high speed milling, after semi-finish machining and finish machining, the processing cycle is only 6 hours, not only improve efficiency, but also greatly improve the quality of mold.4, research on Key Technologies of high-speed CNC machiningNC High-speed machining is a complex systems engineering, involves cutting mechanism, cutting machine, cutter, cutting process monitoring and processing technology and other related hardware and software technology, implementation and development of numerical control high speed cutting technology, rely on this system of various elements, the key technology to realize high-speed CNC cutting technology cannot do without, specifically in the following aspects:1) the mechanism of high speed cutting: the various materials in high speed machining conditions, the chip formation mechanism, variation of cutting force, cutting heat, tool wear patterns and effects on the surface quality, the basic theory above experiments and research, will be conducive to promoting the high-speed cutting process for determining and cutting the amount of choice, and provide a theoretical basis for the processing of specific parts and material formulation, which belongs to the technical principle. At present, to determine the process specification of high speed cutting and cutting ferrous metals and difficult to machine materials, is one of the difficulties in the production of high-speed cutting, and is also the focus of research in the field of high speed machining.2) technology of high speed cutting machine tool module: high-speed cutting machine needs high-speed spindle system, feeding system and high-speed CNC control system. Able to work invery high speed under the high-speed processing requirements of spindle unit, the above general spindle speed 10000 r\/min, some even as high as 60000-100000r\/min, and to ensure good dynamic and thermal properties. The key part is the main shaft bearing, it decides the life of high-speed spindle and load capacity, one of the core components and high-speed cutting machine tool spindle structure, improvement and performance improvement is one of the most important technology of high-speed machine tools. Another important element of the technology is high speed feed system. With the development of machine tool spindle speed increasing, in order to ensure each cutter teeth or feeding amount per rotation invariant, machine tool feed speed and acceleration is also a corresponding increase, the same time to improve travel speed. Therefore, machine tool feed system must move quickly and fast and accurate positioning, which is obviously on the machine tool guide, servo system, working table, put forward new and higher requirements, is the key technology of high-speed machine tool technology control unit.3) the high speed cutting tool technology module: high-speed machining process system composed of machine tools, tool and workpiece, tool is the most active factor. The cutting tool is one of the key technology to ensure high speed cutting smoothly. With the substantial increase of cutting velocity, have put forward different from traditional speed cutting requirements of cutting tool materials, geometric parameters of cutting tool, cutter body structure, high speed cutting tool material and tool manufacturing technology has undergone tremendous changes, high-speed machining, to ensure productivity and high machining precision, but also to to ensure safety and reliability. Therefore, high speed cutting tool system must meet with a clamp repeat positioning accuracy of geometric accuracy good and high loading, clamping rigidity, good high speed when the equilibrium state and safe and reliable. As far as possible to reduce the knife body quality, in order to reduce the high speed rotating centrifugal force by security, meet the requirement for high speed cutting tool, clamping method improvement. Technology research and development tool system is one of the key tasks of high-speed CNC machining.4) numerical control high speed cutting process: high speed cutting as a new cutting method, to be applied to actual production, the lack of application examples for reference, not the amount of cutting and processing parameter database, parameter optimization technology of high speed machining is one of the key technologies of the current constraints should be used. In addition, the high-speed cutting parts NC program must ensure stable load in the whole cutting process, but most CNC software is now used in the automatic programming function still cannot meet the requirements, needs to be added and optimized by manual programming, which reduces the high speed cutting value in a certain extent, must study a new programming method, so that the cutting data power characteristic curve for high speed spindle, give full play to the advantages of numerical control high speed cutting.Development and comprehensive development and application of high speed machining technology depends on the key technology of the above principles, machine tool, cutting tool, theprocess of the.Research status and development trend of high speed cutting technology, 5Due to the high speed cutting has great potential in improving production efficiency, has already become important technologies in the field of competing for the United States and Japan, Germany and other countries. The United States Japan as early as the 60 century, started to study on the mechanism of high speed cutting. The last century 70's, the United States has developed high-speed milling machine maximum speed of up to 20000r\/min. Now, Europe and the United States and other developed countries the production of different specifications of the various high-speed machine tool has the commercial production and into the market, the actual application in aircraft, automotive and mold manufacturing industry. For example, manufacturing enterprises in the American Boeing aircraft, has adopted the high-speed CNC machining technology to machining integral super high-speed milling of aluminum alloy, titanium alloy thin-walled structure and the waveguide, flexible gyroscope frame of the ordinary method of parts. In recent years, the United States, Europe, Japan and other countries of the new generation of NC machine tools, high-speed machining center, high speed tool system and industrialization process further speed up the pace, the specialized production electric spindle technology and high performance products increase; tool system technology of high performance rapid development; application of linear motor in high speed feed system.Our country in the research and development of high speed cutting technology, many universities and research efforts and exploration, including cutting mechanism, cutting tool material, spindle bearing, etc., have also made considerable achievements. However, compared with developed countries, there is still a big gap, basically still in the research stage of laboratory. In order to meet the needs of economic and social development, to meet the needs of aerospace, automobile, mold and other industry, NC Application Research of high-speed cutting technology has a long way to go.At present, the research of high-speed cutting technology has been to the application stage from the stage of experiment. Research in the application of includes two aspects: one is the basic theoretical research on the key technology of high speed machining, including high speed spindle unit and a high speed feed unit, realizing the localization of high-speed machine tool. On the other hand, based on existing laboratory practice technology, application of process performance and process scope. Among them, research on the high speed cutting process is one of the most active research areas at present, the main goal is to directly process through advanced equipment testing or import, processing technology to resolve the issue of key parts, the development and perfection of the high-speed cutting method of special materials; research and development to adapt to the CAD\/CAM software system in high speed machining and post processing system, the processing state safety monitoring system based on a new detection technology.When we entered the twenty-first Century, from the observation of the world, we are in theadvanced manufacturing technology unprecedented rapid development period. Due to the advent of CNC machine tool (NC), the development of a series of CNC machining, such as machining center (MC), flexible manufacturing unit of flexible manufacturing system (FMS), computer integrated manufacturing system, and even the emergence of virtual axis machine tool is completely different with the traditional machine (also known as the six legs machine), closely and machine tool at the same time complement each other up the development of high speed machining technology, new tools, new technology, make the mechanical processing greatly reduces the labor intensity, auxiliary time is greatly shortened, the product quality and the production efficiency is improved greatly, become the development of manufacturing industry and the global economy has played a tremendous role in promoting. In the case of the United States, the manufacturing industry is known as the most economic sectors in the United States, for the United States in the 90's gross domestic product (GDP) growth reached 29%.Today, vigorously develop the NC technology and equipment, has become the strategic decision of the governments in the world, with CNC equipped modern industry and transformation of traditional industries have become the developing direction of manufacturing countries in the world. In the late 90's as the output of CNC machine tools of Germany, Japan, Italy, the rate has reached more than 51.75%. CNC machine tools has become the main equipment in modern manufacturing technology, NC machining technology has become the mainstream of the advanced manufacturing technology, a new era of the modern manufacturing industry. The party's sixteen big clearly pointed out: "to revitalize the equipment manufacturing industry". New China's equipment manufacturing industry after many generations, especially the 20 years of reform and opening up and modernization construction, has established a relatively complete, independent industrial system, has the certain material and technical basis, the overall production scale has been ranked the fourth in the world. Many economists predict, in数控切削技术综述数控高速切削技术(High Speed Machining,HSM,或High Speed Cutting,HSC),是提高加工效率和加工质量的先进制造技术之一,相关技术的研究已成为国内外先进制造技术领域重要的研究方向。
数控技术 外文翻译 外文文献 英文文献
外文翻译NUMERICAL CONTROLNumerical control(N/C)is a form of programmable automation in which the processing equipment is controlled by means of numbers,letters,and other symbols.The numbers,letters,and symbols are coded in an appropriate format to define a program of instructions for a particular work part or job.When the job changes,the program of instructions is changed.The capability to change the program is what makes N/C suitable for low-and medium-volume production.It is much easier to write programs th an to make major alterations of the processing equipment.There are two basic types of numerically controlled machine tools:point—to—point and continuous—path(also called contouring).Point—to—point machines use unsynchronized motors,with the result that the position of the machining head Can be assured only upon completion of a movement,or while only one motor is running.Machines of this type are principally used for straight—line cuts or for drilling or boring.The N/C system consists of the following comp onents:data input,the tape reader with the control unit,feedback devices,and the metal—cutting machine tool or other type of N/C equipment.Data input,also called “man—to—control link”,may be provided to the machine tool manually,or entirely by automatic means.Manual methods when used as the sole source of input data are restricted to a relatively small number of inputs.Examples of manually operated devices are keyboard dials,pushbuttons,switches,or thumbwheel selectors.These are located on a console near t he machine.Dials ale analog devices usually connected to a syn-chro-type resolver or potentiometer.In most cases,pushbuttons,switches,and other similar types of selectors aye digital input devices.Manual input requires that the operator set the controls fo r each operation.It is a slow and tediousprocess and is seldom justified except in elementary machining applications or in special cases.In practically all cases,information is automatically supplied to the control unit and the machine tool by cards,punched tapes,or by magnetic tape.Eight—channel punched paper tape is the most commonly used form of data input for conventional N/C systems.The coded instructions on the tape consist of sections of punched holes called blocks.Each block represents a machine function,a machining operation,or a combination of the two.The entire N/C program on a tape is made up of an accumulation of these successive data blocks.Programs resulting in long tapes all wound on reels like motion-picture film.Programs on relatively short tapes may be continuously repeated by joining the two ends of the tape to form a loop.Once installed,the tape is used again and again without further handling.In this case,the operator simply loads and unloads the parts.Punched tapes ale prepared on typ e writers with special tape—punching attachments or in tape punching units connected directly to a computer system.Tape production is rarelyerror-free.Errors may be initially caused by the part programmer,in card punching or compilation,or as a result of physical damage to the tape during handling,etc.Several trial runs are often necessary to remove all errors and produce an acceptable working tape.While the data on the tape is fed automatically,the actual programming steps ale done manually.Before the coded tape may be prepared,the programmer,often working with a planner or a process engineer, must select the appropriate N/C machine tool,determine the kind of material to be machined,calculate the speeds and feeds,and decide upon the type of tooling needed. The dimensions on the part print are closely examined to determine a suitable zero reference point from which to start the program.A program manuscript is then written which gives coded numerical instructions describing the sequence ofoperations that the machine tool is required to follow to cut the part to the drawing specifications.The control unit receives and stores all coded data until a complete block of information has been accumulated.It then interprets the coded instruction and directs the machine tool through the required motions.The function of the control unit may be better understood by comparing it to the action of a dial telephone,where,as each digit is dialed,it is stored.When the entire number has been dialed,the equipment becomes activated and the call is completed.Silicon photo diodes,located in the tape reader head on the control unit,detect light as it passes through the holes in the moving tape.The light beams are converted to electrical energy,which is amplified to further strengthen the signal.The signals are then sent to registers in the control unit, where actuation signals are relayed to the machine tool drives.Some photoelectric devices are capable of reading at rates up to 1000 characters per second.High reading rates are necessary to maintain continuous machine—tool motion;otherwise dwell marks may be generated by the cutter on the part during contouring operations.The reading device must be capable of reading data blocks at a rate faster than the control system can process the data.A feedback device is a safeguard used on some N/C installations to constantly compensate for errors between the commanded position and the actual location of the moving slides of the machine tool.An N /C machine equipped with this kind of a direct feedback checking device has what is known as a closed-loop system.Positioning control is accomplished by a sensor which,during the actual operation,records the position of the slides and relays this information back to the control unit.Signals thus received ale compared to input signals on the tape,and any discrepancy between them is automatically rectified.In an alternative system,called an open—loop system,the machine is positioned solely by stepping motor drives in response to commands by a controllers.There are three basic types of NC motions, as follows: Point-to-point or Positional Control In point-to-point control the machine tool elements (tools, table, etc.) are moved to programmed locations and the machining operations performed after the motion s are completed. The path or speed of movement between locations is unimportant; only the coordinates of the end points of the motions are accurately controlled. This type of control is suitable for drill presses and some boring machines, where drilling, t apping, or boring operations must be performed at various locations on the work piece. Straight-Line or Linear Control Straight-Line control systems are able to move the cutting tool parallel to one of the major axes of the machine tool at a controlled rate suitable for machining. It is normally only possible to move in one direction at a time, so angular cuts on the work piece are not possible, consequently, for milling machines, only rectangular configurations can be machined or for lathes only surfaces parall el or perpendicular to the spindle axis can be machined. This type of controlled motion is often referred to as linear control or a half-axis of control. Machines with this form of control are also capable ofpoint-to-point control.Continuous Path or Contouring Control In continuous path control the motions of two or more of the machine axes are controlled simultaneously, so that the position and velocity of the can be tool are changed continuously. In this way curves and surfaces can be machined at a controlled feed rate. It is the function of the interpolator in the controller to determine the increments of the individual controlled axes of the machines necessary to produce the desired motion. This type of control is referred to as continuous control or a full axis of control.Some terminology concerning controlled motions for NC machines has been introduced. For example, some machines are referred to asfour-or five-or even six-axis machines. For a vertical milling machine three axes of control are fairly obvious, these being the usual X, Y, Z coordinate directions. A fourth or fifth axis of control would imply some form of rotary table to index the work piece or possibly to provide angular motion of the work head. Thus, in NC terminology an axis of control is any controlled motion of the machine elements (spindles, tables, etc). A further complication is use of the term half-axis of control; for example, many milling machines are referred to as 2.5-axis machine. This means that continuous control is possib le for two motions (axes) and only linear control is possible for the third axis. Applied to vertical milling machines, 2.5axis control means contouring in the X, Y plane and linear motion only in the Z direction. With these machines three-dimensional objects have to be machined with water lines around the surface at different heights. With an alternative terminology the same machine could be called a 2CL machine (C for continuous, L for linear control). Thus, a milling machine with continuous control in th e X, Y, Z directions could be termed be a three-axis machine or a 3c machine, Similarly, lathes are usually two axis or 2C machines. The degree of work precision depends almost entirely upon the accuracy of the lead screw and the rigidity of the machine st ructure.With this system.there is no self-correcting action or feedback of information to the control unit.In the event of an unexpected malfunction,the control unit continues to put out pulses of electrical current.If,for example,the table on a N/C milling machine were suddenly to become overloaded,no response would be sent back to the controller.Because stepping motors are not sensitive to load variations,many N/C systems are designed to permit the motors to stall when the resisting torque exceeds the motor torque.Other systems are in use,however,which in spite of the possibility of damage to the machine structure or to the mechanical system,ale designed with special high—torque steppingmotors.In this case,the motors have sufficient capacity to “overpower” the system in the event of almost any contingency.The original N/C used the closed—loop system.Of the two systems,closed and open loop,closed loop is more accurate and,as a consequence,is generally more expensive.Initially,open—loop systems were used almost entirely for light-duty applications because of inherent power limitations previously associated with conventional electric stepping motors.Recent advances in the development of electro hydraulic stepping motors have led to increasingly heavier machin e load applications.数控技术数控是可编程自动化技术的一种形式,通过数字、字母和其他符号来控制加工设备。
数控技术 外文翻译 外文文献 英文文献 数控技术的发展与维修
Development and maintenance of CNC technology Numerical control technology and equipment is the development of new high-tech industry and cutting-edge enabling technology, industry and the most basic equipment. The world information industry, biological industry, aviation, aerospace and other defense industry widely used numerical techniques to improve manufacturing capacity and level, to improve the adaptability of the market and competitiveness. Industrial countries and CNC numerical control technology and equipment will also be listed as countries of strategic materials, not only to develop their own numerical control technology and industry, and in "sophisticated" technology and equipment, numerical control key aspects of the policy of closures and restrictions. Therefore, efforts to develop advanced numerical control technology as the core manufacturing technology has become the world's developed countries to accelerate economic development, enhance the comprehensive national strength and an important way to statehood.Part I: the development of CNC machine tools trends in individual1. High speed, high accuracy, high reliabilityHigh speed: To improve the speed and increase feed spindle speed.High precision: the precision from micron to sub-micron level, and even the nano-level (high reliability: the reliability of numerical control system generally higher than the reliability of numerical control equipment more than an order of magnitude, but not the higher the better reliability because the goods by the cost performance constraints.2. CompositeComposite function CNC machine tool development, its core is in a single machine to complete the turning, milling, drilling, tapping, reaming and reaming and other operating procedures, thereby increasing the efficiency and precision machine tools to improve production flexibility.3. IntelligentIntelligent content included in all aspects of the numerical control system: the pursuit of processing efficiency and processing quality of intelligence; to improve the performance and the use of convenient connections and other aspects of intelligence; simplify programming, simplifying operational intelligence; also like the intelligent automatic programming, intelligent man-machine interface, as well as intelligent diagnostics, intelligent monitoring and other aspects, to facilitate system diagnostics and maintenance.4. Flexible, integratedThe world of CNC machine tools to the development trend of flexible automation systems are: from the point (CNC single, composite machining centers and CNC machine tools), line (FMC, FMS, FTL, FML) to the surface (Section workshop independent manufacturing island FA) , body (CIMS, distributed network integrated manufacturing system) direction, the other to focus on applied and economic direction. Flexible automation technology is the industry to adapt to dynamic market demands and quickly update the primary means of product is the main trend of national manufacturing industry is the basis for the field of advanced manufacturing technology.Second, personalization is the adaptability of the market trendsToday's market, gradually formed the pattern of international cooperation, the products becoming more competitive, efficient and accurate processing of the escalating demand means, the user's individual requirements become increasingly strong, professional, specialization, more and more high-tech machine tools by the users of all ages.Third, the open architecture trend isThe core of a new generation of CNC system development is open. Open software platform and hardware platforms are open systems, modular, hierarchical structure, and through out the form to provide a unified application interface.CNC system to address the closure of the traditional CNC applications and industrial production problems. At present, many countries of open CNC system, CNC system has become an open numerical control system of the future of the road. The open numerical control system architecture specification, communication specifications, configuration specifications, operating platform, function libraries and CNC numerical control system software development tools, system function is the core of the current study. Network numerical control equipment is nearly two years of a new focus. NC network equipment will greatly satisfy the production lines, manufacturing systems, manufacturing information integration needs of enterprises, but also achieve new manufacturing model, such as agile manufacturing, virtual enterprises, global manufacturing the base unit. Some well-known at home and abroad, and CNC CNC machine tools manufacturing company inPart II: Machine MaintenanceCNC machine tools is electronic technology, measurement technology, automation technology, semiconductor technology, computer technology and electrical technology, and integrated set of automation equipment, high precision, high efficiency and high flexibility. CNC machine tools is a process control equipment and asked him in real-time control of the accuracy of every moment of work, any part of the fault and failure, so that the machine will shut down, resulting in production stoppages, which seriously affected and restricted the production efficiency . CNC machine tools in many industries to work the device is critical, if not after a failure in its maintenance and troubleshooting time, it will cause greater economic losses. Therefore, the principle that complex numerical control system, structure, maintenance of sophisticated equipment is necessary. CNC machine tools to enhance fault diagnosis and maintenance of power, can improve the reliability of CNC machine tools, CNC machine tools is conducive to the promotion and use.CNC machine tools is a mechanical, electrical, hydraulic, gas combination of complex equipment, though the reasons for failure vary, but the failure occurred, the general idea of the steps are the same. Fails,Spindle start below to stop immediately after the fault diagnosis of CNC machine tools as an example the general process.First, the fault-site investigation. The survey content includes 1, 2 types of failure, the failure frequency of 3, 4, external conditions, the operating conditions 5, 6, machine conditions, the functioning of 7, wiring between machine tools and systems 8, CNC equipment visual inspection. After an investigation, such failure is spindle class failure, only once, outside of all normal, the operator of a boot to reflect this situation.Second, the fault information collation, analysis. For some simple fault, because not alot of time, the method can be used form of logical reasoning, analysis, identification and troubleshooting. After a failed on-site investigation for several reasons we suspect that the system output pulse ①②drive is not enough time to move the state line to control the spindle components ③④damage to the spindle motor short-circuit, causing the spindle thermal relay protection ⑤ not with self-control loop lock circuits, and the parameter is set to pulse signal output, so that the spindle can not operate normally. Identify possible reasons to rule out one by one.Third, conduct fault diagnosis and troubleshooting.Diagnosis usually follows the following principles: 1, after the first outside inside. Reliable line of modern CNC system increasingly high failure rate of CNC system itself less and less, and most are non-occurrence of failure causes the system itself. The CNC machine is a mechanical, hydraulic, electrical as one of the tools, the occurrence of the fault will be reflected by these three comprehensive, maintenance personnel should be from outside to inside one by one investigation to avoid arbitrary unsealed, demolition, otherwise expand the malfunction, so that the loss of precision machine tools, slow performance, outside the system detected the fault is due to open one by one, hydraulic components, pneumatic components, electrical actuators, mechanical devices caused problems. 2, the first after the electrical machinery. In general, the mechanical failure easier to find, and numerical control system and electrical fault diagnosis more difficult, before the troubleshooting to rule out mechanical failure of the first 3, after the first static dynamic. Power off the machine first, quiescent state, through understanding, observation, testing, analysis, confirm the power failure will not result in expansion of the incident only after the power to the machine, run the state, the dynamic of observation, inspection and testing, to find fault. While after the devastating power failure, you must first rule out the danger, before electricity. 4, after the first simple and complex. When multiple failures are intertwined, and sometimes impossible to start with, we should first solve the problem easily, then solve the difficult problem, often a simple problem to solve, the difficulty of the problem may also become easier.CNC machine tools in the fault detection process, should make full use of numerical control system self-diagnostic features to be judged, but also flexibility in the use of some common troubleshooting methods. Troubleshooting common methods are:1. Routine examination methodRoutine examination method is mainly of hands, eyes, ears, nose and other organs of the fault occurrence of various light, sound, smell and abnormal observations and careful look at every system, follow the "first post outside of" the principle of fault diagnosis by looking, listening, smelling, asking, mold and so on, from outside to inside one by one check, the fault can often be narrowed down to a module or a printed circuit board. This requires maintenance personnel have a wealth of practical experience, to the wider multidisciplinary and comprehensive knowledge of the ability to judge.2. Self-diagnostic function methodModern CNC system has yet to achieve a high degree of intelligence. But already has a strong self-diagnostic function. CNC ready to monitor the hardware and software is working. Once the abnormal, immediately displayed on the CRT alarm or fault LEDs indicate the approximate cause. Using self-diagnosis function, but also shows the interface signals between the system and the host state, in order to determine the fault occurred in themechanical part or parts of NC system, and indicate the approximate fault location. This method is currently the most effective maintenance methods.3. Functional program testing methodSo-called functional program testing method is commonly used in the numerical control system functions and special features, such as linear positioning, circular interpolation, helical cut, fixed cycle, such as the user macro programming by hand or automatic programming methods, the preparation of test procedures into a functional program , into the numerical control system, and then start the CNC system to make it run, to check the im time the first boot of CNC whether a programming error or operational error or machine4. Spare parts substitutionSpare parts replacement method is a simple method to determine the scene is one of the most commonly used. The so-called spare substitution is generally the cause of failure in the analysis of the case, maintenance personnel can use the alternate PCB, templates, integrated circuit chip or replace the questionable parts of components, which narrowed the fault to a printed circuit board or chip level. It is actually in the verification analysis is correct. However, before switching the standby board should carefully check the spare board is intact, and should check the status of reserve board should be fully consistent with the original board the state. This includes checking with the board selection switch, set the location and the short rod potentiometer position. In short, we must strictly in accordance with the system's operation, maintenance requirements manual operation.In determining the replacement of a part to, should carefully check the relevant connected to electrical lines and other related, confirming that no failure up to the new replacement to prevent failures caused by external damage to replace the parts up.5. Transfer ActThe so-called transfer method is to have the same numerical control system features two printed circuit boards, templates, integrated circuit chips or components to exchange, observed failure phenomena be transferred. In this way, the system can quickly determine the fault position. This method is actually a kind of spare parts substitution. Therefore, the considerations described in the same spare parts substitution.6. Parameter check methodKnown parameters can directly affect the numerical performance of CNC machine tools. Parameters are usually stored in the magnetic bubble memory, or stored in batteries to be maintained by the CMOS RAM, once the battery is low or because of outside interference and other factors, some parameters will be lost or change in chaos, so that the machine does not work. At this point, through the proofreading, correction parameters, will be able to troubleshoot. When the machine idle for a long time to work again for no reason that there is no normal or failure without warning, it should be based on fault characteristics, inspection and proof-reading the relevant parameters.After a long run of CNC machine tools, wear and tear due to its mechanical drive components, electrical component performance changes and other reasons, also need to adjust the parameters of its. Some machine tool failure is often not timely because the parameters change due to some not meet. Of course, these failures are the fault of the areas are soft.7. Measurement of Comparative LawCNC system in the design of printed circuit board manufacturing plant, in order to adjust, repair facilities, in the printed circuit board designed a number of test terminals. Users can also use normal printed circuit board terminals comparing the measured and the difference between the printed circuit board failure. These terminals can detect the voltage and waveform measurements, analyze the causes of failure and failure location. Even on a normal printed circuit board can sometimes artificially create "fault", such as broken connection or short circuit, unplug the components, in order to determine the real cause of failure. Therefore, maintenance personnel should be in the usual accumulation of key parts of the printed circuit board or failure-prone parts of the right in the normal waveform and voltage values. Because the CNC system manufacturer often does not provide the information in this regard.8. Percussion methodWhen the CNC system failures showed Ruoyouruowu, often used method for detecting the fault struck the site lies. This is because the numerical control system is composed by the multi-block printed circuit boards, each board has a lot of solder joints, plates or between modules and is connected through the connectors and cables. Therefore, any cold solder joint or bad, may cause a malfunction. When the tap with the insulation and poor contact with Weld doubt at fault must be repeated reproduction.9. Local heating methodAfter a long running CNC system components are to be aging, performance will deteriorate. When they are not fully damaged, failures will become from time to time. Then heat can be used such as a hair dryer or electric iron is suspected to local heating components, accelerating the aging so thoroughly exposed fault components. Of course, using this method, be sure to pay attention to components of the temperature parameters, do not roast the original device is a good or bad.10. Principle of analysisThe composition according to principles of numerical control system can be analyzed from various points of logical levels and logical parameters (such as voltage or waveform) and then with a multimeter, logic pen, only the oscilloscope or logic analyzer to measure, analyze and compare, and thus failure positioning. Using this method, which requires maintenance personnel to be on the whole system or the principle of each circuit have a clear, deep understanding.Based on the above principles and methods, we may be itemized on the check it and eliminate the causes.The first possible failure for the system output pulse time is not enough, we adjust the M-code system, start the spindle output time, found the problem still exists, and then find the next possible cause may be in the drive to move the state, refer to the manual drive , set parameters start the spindle, the problem still exists we suspected spindle motor short-circuit, resulting in thermal relay protection. Then find the cause of the short, so that the spindle thermal relay reset the start and found that the normal operation of the spindle, the problem solved.Fourth, do a lessons learned and recorded. After troubleshooting, repair work can not be considered complete, still need technical and management aspects of the underlying causes of failure have to take appropriate measures to prevent failures from happening again. Underfield conditions when necessary use of mature technologies to transform and improve the equipment. Finally, the failure of the maintenance of the phenomenon, cause analysis, resolution process, the replacement of components, legacy, etc. to make a record.数控技术的发展与维修数控技术及装备是发展新兴高新技术产业和尖端工业的使能技术和最基本的装备。
机械类数控车床外文翻译外文文献英文文献车床.doc
LathesLathes are machine tools designed primarily to do turning, facing and boring, Very little turning is done on other types of machine tools, and none can do it with equal facility. Because lathes also can do drilling and reaming, their versatility permits several operations to be done with a single setup of the work piece. Consequently, more lathes of various types are used in manufacturing than any other machine tool.The essential components of a lathe are the bed, headstock assembly, tailstock assembly, and the leads crew and feed rod.The bed is the backbone of a lathe. It usually is made of well normalized or aged gray or nodular cast iron and provides s heavy, rigid frame on which all the other basic components are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted V-shape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets, They are precision-machined to assure accuracy of alignment. On most modern lathes the way are surface-hardened to resist wear and abrasion, but precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed.The headstock is mounted in a foxed position on the inner ways, usually at the left end of the bed. It provides a powered means of rotating the word at various speeds . Essentially, it consists of a hollow spindle, mounted in accurate bearings, and a set of transmission gears-similar to a truck transmission—through which the spindle can be rotated at a number of speeds. Most lathes provide from 8 to 18 speeds, usually in a geometric ratio, and on modern lathes all the speeds can be obtained merely by moving from two to four levers. An increasing trend is to provide a continuously variable speed range through electrical or mechanical drives.Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually preloaded tapered roller or ball types. The spindle has a hole extending through its length, through which long bar stock can be fed. The size of maximum size of bar stock that can be machined when the material must be fed through spindle.The tailsticd assembly consists, essentially, of three parts. A lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired location, An upper casting fits on the lower one and can be moved transversely upon it, on some type of keyed ways, to permit aligning the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 51 to 76mm(2to 3 inches) in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a hand wheel and screw.The size of a lathe is designated by two dimensions. The first is known as the swing. This is the maximum diameter of work that can be rotated on a lathe. It is approximately twice the distance between the line connecting the lathe centers and the nearest point on the ways, The second size dimension is the maximum distance between centers. The swing thus indicates the maximum work piece diameter that can be turned in the lathe, while the distance between centers indicates the maximum length of work piece that can be mounted between centers.Engine lathes are the type most frequently used in manufacturing. They are heavy-duty machine tools with all the components described previously and have power drive for all tool movements except on the compound rest. They commonly range in size from 305 to 610 mm(12 to 24 inches)swing and from 610 to 1219 mm(24 to 48 inches) center distances, but swings up to 1270 mm(50 inches) and center distances upto 3658mm(12 feet) are not uncommon. Most have chip pans and a built-in coolant circulating system. Smaller engine lathes-with swings usually not over 330 mm (13 inches ) –also are available in bench type, designed for the bed to be mounted on a bench on a bench or cabinet.Although engine lathes are versatile and very useful, because of the time required for changing and setting tools and for making measurements on the work piece, thy are not suitable for quantity production. Often the actual chip-production tine is less than 30% of the total cycle time. In addition, a skilled machinist is required for all the operations, and such persons are costly and often in short supply. However, much of the operator’s time is consumed by simple, repetitious adjustments and in watching chips being made. Consequently, to reduce or eliminate the amount of skilled labor that is required, turret lathes, screw machines, and other types of semiautomatic and automatic lathes have been highly developed and are widely used in manufacturing.2 Numerical ControlOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC). Prior to the advent of NC, all machine tools ere manually operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator. Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems through the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool. For a machine tool to be numerically controlled, it must be interfaced with a device for accepting and decoding the programmed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operators, and it has done so. Numerical control machines are more accurate than manually operated machines, they can produce parts more uniformly, they are faster, and the long-run tooling costs are lower. The development of NC led to the development of several other innovations in manufacturing technology:Electrical discharge machining,Laser cutting,Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide of parts, each involving an assortment of widely varied and complex machining processes. Numerical control has allowed manufacturers to undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tolls and processes.Like so many advanced technologies, NC was born in the laboratories of the Massachusetts Institute of Technology. The concept of NC was developed in the early 1950s with funding provided by the U.S. Air Force. In its earliest stages, NC machines were able to made straight cuts efficiently and effectively.However, curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter the straight lines making up the steps, the smoother is the curve, Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language. This is a special programming language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the fur ther development from those used today. The machines had hardwired logic circuits. The instructional programs were written on punchedpaper, which was later to be replaced by magnetic plastic tape. A tape reader was used to interpret the instructions written on the tape for the machine. Together, all of this represented a giant step forward in the control of machine tools. However, there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium. It was common for the paper tape containing the programmed instructions to break or tear during a machining process. This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to be rerun through the reader. If it was necessary to produce 100 copies of a given part, it was also necessary to run the paper tape through the reader 100 separate tines. Fragile paper tapes simply could not withstand the rigors of a shop floor environment and this kind of repeated use.This led to the development of a special magnetic plastic tape. Whereas the paper carried the programmed instructions as a series of holes punched in the tape, the plastic tape carried the instructions as a series of magnetic dots. The plastic tape was much stronger than the paper tape, which solved the problem of frequent tearing and breakage. However, it still left two other problems.The most important of these was that it was difficult or impossible to change the instructions entered on the tape. To made even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape through the reader as many times as there were parts to be produced. Fortunately, computer technology became a reality and soon solved the problems of NC associated with punched paper and plastic tape.The development of a concept known as direct numerical control (DNC) solved the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions. In direct numerical control, machine tools are tied, via a data transmission link, to a host computer. Programs for operating the machine tools are stored in the host computer and fed to the machine tool an needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However, it is subject to the same limitations as all technologies that depend on a host computer. When the host computer goes down, the machine tools also experience downtime. This problem led to the development of computer numerical control.3 TurningThe engine lathe, one of the oldest metal removal machines, has a number of useful and highly desirable attributes. Today these lathes are used primarily in small shops where smaller quantities rather than large production runs are encountered.The engine lathe has been replaced in today’s production shops by a wide variety of automatic lathes such as automatic of single-point tooling for maximum metal removal, and the use of form tools for finish on a par with the fastest processing equipment on the scene today.Tolerances for the engine lathe depend primarily on the skill of the operator. The design engineer must be careful in using tolerances of an experimental part that has been produced on the engine lathe by a skilled operator. In redesigning an experimental part for production, economical tolerances should be used.Turret Lathes Production machining equipment must be evaluated now, more than ever before, this criterion for establishing the production qualification of a specific method, the turret lathe merits a high rating.In designing for low quantities such as 100 or 200 parts, it is most economical to use the turret lathe. In achieving the optimum tolerances possible on the turrets lathe, the designer should strive for a minimum of operations.Automatic Screw Machines Generally, automatic screw machines fall into several categories; single-spindle automatics, multiple-spindle automatics and automatic chucking machines. Originally designed for rapid, automatic production of screws and similar threaded parts, the automatic screw machine has long since exceeded the confines of this narrow field, and today plays a vital role in the mass production of a variety of precision parts. Quantities play an important part in the economy of the parts machined on the automatic screw machine. Quantities less than on the automatic screw machine. The cost of the parts machined can be reduced if the minimum economical lot size is calculated and the proper machine is selected for these quantities.Automatic Tracer Lathes Since surface roughness depends greatly on material turned, tooling , and feeds and speeds employed, minimum tolerances that can be held on automatic tracer lathes are not necessarily the most economical tolerances.In some cases, tolerances of 0.05mm are held in continuous production using but one cut . groove width can be held to 0.125mm on some parts. Bores and single-point finishes can be held to 0.0125mm. On high-production runs where maximum output is desirable, a minimum tolerance of 0.125mm is economical on both diameter and length of turn.车床车床主要是为了进行车外圆、车端面和镗孔等项工作而设计的机床。
数控车床主轴部件机械外文文献翻译、中英文翻译、外文翻译
数控车床主轴部件机械外文文献翻译、中英文翻译、外文翻译中国地质大学长城学院本科毕业设计外文资料翻译系别:工程技术系专业:机械设计制造及其自动化姓名:王泽民学号: 052116362015年4月30日外文原文翻译数控车床主轴部件车床是主要用于生成旋转表面和平整边缘的机床。
根据它们的使用目的、结构、能同时被安装刀具的数量和自动化的程度,车床—更确切地说是车床类的机床,可以被分成以下几类:(1)普通车床(2)万能车床(3)转塔车床(4)立式车床(5)自动车床(6)特殊车床虽然车床类的机床多种多样,但它们在结构和操作原理上具有共同特性。
这些特性可以通过普通车床这一最常用的代表性类型来最好地说明。
下面是关于图11.1所示普通车床的主要部分的描述。
车床床身:车床床身是包含了在两个垂直支柱上水平横梁的主骨架。
为减振它一般由灰铸铁或球墨铸铁铸造而成。
它上面有能让大拖板轻易纵向滑动的导轨。
车床床身的高度应适当以让技师容易而舒适地工作。
主轴箱:主轴箱固定在车床床身的左侧,它包括轴线平行于导轨的主轴。
主轴通过装在主轴箱内的齿轮箱驱动。
齿轮箱的功能是给主轴提供若干不同的速度(通常是6到18速)。
有些现代车床具有采用摩擦、电力或液压驱动的无级调速主轴箱。
主轴往往是中空的,即纵向有一通孔。
如果采取连续生产,棒料能通过此孔进给。
同时,此孔为锥形表面可以安装普通车床顶尖。
主轴外表面是螺纹可以安装卡盘、花盘或类似的装置。
尾架:尾架总成基本包括三部分,底座、尾架体和套筒轴。
底座是能在车床床身上沿导轨滑动的铸件,它有一定位装置能让整个尾架根据工件长度锁定在任何需要位置。
这通过使用手轮和螺杆来达到,与螺杆啮合的是一固接在套筒轴上的螺母。
套筒轴开口端的孔是锥形的,能安装车床顶尖或诸如麻花钻和镗杆之类的工具。
套筒轴通过定位装置能沿着它的移动路径被锁定在任何点。
大拖板:大拖板的主要功能是安装刀具和产生纵向和/或横向进给。
它实际上是一由车床床身V形导轨引导的、能在车床床身主轴箱和尾架之间滑动的H形滑块。
数控机床外文文献翻译、中英文翻译
1 原文一CNC machine tools Outdate, J. and Joe, J. Configuration Synthesis of Machining Centers with Tool ,John Wiley & sons, 2001 While the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment. The The first first first benefit benefit benefit offered offered offered by by by all all all forms forms forms of of of CNC CNC CNC machine machine machine tools tools tools is is is improved improved automation. automation. The The The operator operator operator intervention intervention intervention related related related to to to producing producing producing work work work pieces pieces pieces can can can be be reduced reduced or or or eliminated. eliminated. eliminated. Many Many Many CNC CNC CNC machines machines machines can can can run run run unattended unattended unattended during during during their their their entire entire machining machining cycle, cycle, cycle, freeing freeing freeing the the the operator operator operator to to to do do do other other other tasks. tasks. tasks. This This This gives gives gives the the the CNC CNC CNC user user several several side side side benefits benefits benefits including including including reduced reduced reduced operator operator operator fatigue, fatigue, fatigue, fewer fewer fewer mistakes mistakes mistakes caused caused caused by by human human error, error, error, and and and consistent consistent consistent and and and predictable predictable predictable machining machining machining time time time for for for each each each work work work piece. piece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing work pieces with conventional machine tools. The second major benefit of CNC technology is consistent a nd accurate work and accurate work pieces. Today's CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical work pieces can be easily produced with precision and consistency. A third benefit offered by most forms of CNC machine tools is flexibility. Since these these machines machines machines are are are run run run from from from programs, programs, programs, running running running a a a different different different workpiece workpiece workpiece is is is almost almost almost as as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since these machines are very easy to set up and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with today's just-in-time (JIT) product requirements. Motion control - the heart of CNC The The most most most basic basic basic function function function of of of any any any CNC CNC CNC machine machine machine is is is automatic, automatic, automatic, precise, precise, precise, and and consistent consistent motion motion motion control. control. control. Rather Rather Rather than than than applying applying applying completely completely completely mechanical mechanical mechanical devices devices devices to to cause cause motion motion motion as as as is is is required required required on on on most most most conventional conventional conventional machine machine machine tools, tools, tools, CNC CNC CNC machines machines allow motion control in a revolutionary manner2. All forms of CNC equipment have two two or or or more more more directions directions directions of of of motion, motion, motion, called called called axes. axes. axes. These These These axes axes axes can can can be be be precisely precisely precisely and and automatically automatically positioned positioned positioned along along along their their their lengths lengths lengths of of of travel. travel. travel. The The The two two two most most most common common common axis axis types are linear (driven along a straight path) and rotary (driven along a circular path). Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed programmed commands. commands. commands. Generally Generally Generally speaking, speaking, speaking, the the the motion motion motion type type type (rapid, (rapid, (rapid, linear, linear, linear, and and circular), the axes to move, the amount of motion and the motion rate (federate) are programmable with almost all CNC machine tools. A CNC command executed within the control tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw. And the ball screw drives the linear axis (slide). A feedback device (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3. Refer to fig.1. fig.1 typical drive system of a CNC machine tool Though a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw on the vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis. How axis motion is commanded - understanding coordinate systems It would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion motion amount4. amount4. amount4. (This (This (This would would would be be be like like like having having having to to to figure figure figure out out out how how how many many many turns turns turns of of of the the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more a much simpler and more logical logical way way way by by by utilizing utilizing utilizing some some some form form form of of of coordinate coordinate coordinate system. system. system. The The The two two two most most most popular popular coordinate coordinate systems systems systems used used used with with with CNC CNC CNC machines machines machines are are are the the the rectangular rectangular rectangular coordinate coordinate coordinate system system and and the the the polar polar polar coordinate coordinate coordinate system. system. system. By By By far, far, far, the the the more more more popular popular popular of of of these these these two two two is is is the the rectangular coordinate system. The program zero point establishes the point of reference for motion commands in in a a a CNC CNC CNC program. program. program. This This This allows allows allows the the the programmer programmer programmer to to to specify specify specify movements movements movements from from from a a common common location. location. location. If If If program program program zero zero zero is is is chosen chosen chosen wisely, wisely, wisely, usually usually usually coordinates coordinates coordinates needed needed needed for for the program can be taken directly from the print. With this technique, if the programmer wishes the tool to be sent to a position one one inch inch inch to to to the the the right right of of the the the program program program zero zero zero point, point, point, X1.0 X1.0 X1.0 is is is commanded. commanded. If If the the programmer wishes the tool to move to a position one inch above the program zero point, Y1.0 is commanded. The control will automatically determine how many times to rotate each axis drive motor and ball screw to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner. Refer to fig.2, 3. fig.2, 3. Understanding absolute versus incremental motion All discussions to this point assume that the absolute mode of programming is used6. The most common CNC word used to designate the absolute mode is G90. In the absolute mode, the end points for all motions will be specified from the program zero point. For beginners, this is usually the best and easiest method of specifying end points for motion commands. However, there is another way of specifying end points for axis motion. In the incremental mode (commonly specified by G91), end points for motions are are specified specified specified from from from the the the tool's tool's tool's current current current position, position, position, not not not from from from program program program zero. zero. zero. With With With this this method method of of of commanding commanding commanding motion, motion, motion, the the the programmer programmer programmer must must must always always always be be be asking asking asking "How "How "How far far should should I I I move move move the the the tool?" tool?" tool?" While While While there there there are are are times times times when when when the the the incremental incremental incremental mode mode mode can can can be be very helpful, generally speaking, this is the more cumbersome and difficult method of specifying motion and beginners should concentrate on using the absolute mode. Be Be careful careful careful when when when making making making motion motion motion commands. commands. commands. Beginners Beginners Beginners have have have the the the tendency tendency tendency to to think think incrementally. incrementally. incrementally. If If If working working working in in in the the the absolute absolute absolute mode mode mode (as (as (as beginners beginners beginners should), should), should), the the programmer should always be asking "To what position should the tool be moved?" This position is relative to program zero, NOT from the tools current position. Aside Aside from from from making making making it it it very very very easy easy easy to to to determine determine determine the the the current current current position position position for for for any any command, another benefit of working in the absolute mode has to do with mistakes made during motion commands. In the absolute mode, if a motion mistake is made in one one command command command of of of the the the program, program, program, only only only one one one movement movement movement will will will be be be incorrect. incorrect. incorrect. On On On the the the other other hand, if a mistake is made during incremental movements, all motions from the point of the mistake will also be incorrect. Assigning program zero Keep in mind that the CNC control must be told the location of the program zero point by one means or another. How this is done varies dramatically from one CNC machine and control to another8. One (older) method is to assign program zero in the program. program. With this With this method, the programmer tells the control how far it is from from the the program program zero point to zero point to t he starting position of the machine. This the starting position of the machine. This is is commonly done commonly done with a G92 (or G50) command at least at the beginning of the program and possibly at the beginning of each tool. Another, newer and better way to assign program zero is through some form of offset. Refer to fig.4. Commonly machining center control manufacturers call offsets used to assign program zero fixture offsets. Turning center manufacturers commonly call offsets used to assign program zero for each tool geometry offsets. fig.4 assign program zero through G54 Flexible manufacturing cells A flexible manufacturing cell (FMC) can be considered as a flexible manufacturing subsystem. The following differences exist between the FMC and the FMS: 1. An FMC is not under the direct control of the central computer. Instead, instructions from the central computer are passed to the cell controller. 2. The cell is limited in the number of part families it can manufacture. The following elements are normally found in an FMC: • Cell controller • Programmable logic controller (PLC) • More than one machine tool • A materials handling device (robot or pallet) The The FMC FMC FMC executes executes executes fixed fixed fixed machining machining machining operations operations operations with with with parts parts parts flowing flowing flowing sequentially sequentially between operations. High speed machining The term High Speed Machining (HSM) commonly refers to end milling at high rotational rotational speeds speeds speeds and and and high high high surface surface surface feeds. feeds. feeds. For For For instance, instance, instance, the the the routing routing routing of of of pockets pockets pockets in in aluminum airframe sections with a very high material removal rate1. Refer to fig.5 for the cutting data designations and for mulas. Over the past 60 60 years, HSM years, HSM has been applied to a wide range of metallic and non-metallic workpiece materials, including the the production production production of of of components components components with with with specific specific specific surface surface surface topography topography topography requirements requirements requirements and and machining machining of of of materials materials materials with with with hardness hardness hardness of of of 50 50 50 HRC HRC HRC and and and above. above. above. With With most most steel steel components components hardened hardened hardened to to to approximately approximately approximately 32-42 32-42 32-42 HRC, HRC, HRC, machining machining machining options options options currently currently include: Fig.5 cutting data rough rough machining machining machining and and and semi-finishing semi-finishing semi-finishing of of of the the the material material material in in in its its its soft soft soft (annealed) (annealed) condition heat treatment to achieve the final required hardness = 63 HRC machining of electrodes and Electrical Discharge Machining (EDM) of specific parts of dies and moulds (specifically small radii and deep cavities with limited accessibility for metal cutting cutting tools) tools) tools) finishing finishing finishing and and and super-finishing super-finishing super-finishing of of of cylindrical/flat/cavity cylindrical/flat/cavity cylindrical/flat/cavity surfaces surfaces surfaces with with appropriate cemented carbide, cermets, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN) For many components, the production process involves a combination of these options options and and and in in in the the the case case case of of of dies dies dies and and and moulds moulds moulds it it it also also also includes includes includes time time time consuming consuming consuming hand hand finishing. Consequently, production costs can be high and lead times excessive. It is typical in the die and mould industry to produce one or just a few tools of the same design. The process involves constant changes to the design, and because of these changes there is also a corresponding need for measuring and reverse engineering. The main criteria are the quality level of the die or mould regarding dimensional, geometric and surface accuracy. If the quality level after machining is poor and if it cannot meet the requirements, there will be a varying need of manual finishing work. This work produces satisfactory surface accuracy, but it always has a negative impact on the dimensional and geometric accuracy. One of the main aims for the die and mould industry has been, and still is, to reduce or eliminate the need for manual polishing and thus improve the quality and shorten the production costs and lead times. Main economical and technical factors for the development of HSM Survival The The ever ever ever increasing increasing increasing competition competition competition in in in the the the marketplace marketplace marketplace is is is continually continually continually setting setting setting new new standards. The demands on time and cost efficiency is getting higher and higher. This has forced the development of new processes and production techniques to take place. HSM provides hope and solutions... Materials The development of new, more difficult to machine materials has underlined the necessity necessity to to to find find find new new new machining machining machining solutions. solutions. solutions. The The The aerospace aerospace aerospace industry industry industry has has has its its its heat heat resistant resistant and and and stainless stainless stainless steel steel steel alloys. alloys. alloys. The The The automotive automotive automotive industry industry industry has has has different different different bimetal bimetal compositions, Compact Graphite Iron and an ever increasing volume of aluminum3. The The die die die and and and mould mould mould industry industry industry mainly mainly mainly has has has to to to face face face the the the problem problem problem of of of machining machining machining high high hardened tool steels, from roughing to finishing. Quality The The demand demand demand for for for higher higher higher component component component or or or product product product quality quality quality is is is the the the result result result of of of ever ever increasing competition. HSM, if applied correctly, offers a number of solutions in this area. Substitution of manual finishing is one example, which is especially important on dies and moulds or components with a complex 3D geometry. Processes The demands on shorter throughput times via fewer setups and simplified flows (logistics) can in most cases, be solved by HSM. A typical target within the die and mould industry is to completely machine fully hardened small sized tools in one setup. Costly and time consuming EDM processes processes can can can also also also be reduced or eliminated with be reduced or eliminated with HSM. Design & development One of the main tools in today's competition is to sell products on the value of novelty. novelty. The The The average average average product product product life life life cycle cycle cycle on on on cars cars cars today today today is is is 4 4 4 years, years, years, computers computers computers and and accessories accessories 1.5 1.5 1.5 years, years, years, hand hand hand phones phones phones 3 3 3 months... months... months... One One One of of of the the the prerequisites prerequisites prerequisites of of of this this development of fast design changes and rapid product development time is the HSM technique. Complex products There is an increase of m ulti-functional multi-functional multi-functional surfaces surfaces surfaces on components, such on components, such a s new as new design design of of of turbine turbine turbine blades blades blades giving giving giving new new new and and and optimized optimized optimized functions functions functions and and and features. features. features. Earlier Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs have to be finished via machining and preferably by HSM . There are also more and more examples of thin walled workpiece that have to be machined (medical equipment, electronics, defense products, computer parts). Production equipment The The strong strong strong development development development of of of cutting cutting cutting materials, materials, materials, holding holding holding tools, tools, tools, machine machine machine tools, tools, controls and especially CAD/CAM features and equipment, has opened possibilities that must be met with new production methods and techniques5. Definition of HSM Salomon's Salomon's theory, theory, theory, "Machining "Machining "Machining with with with high high high cutting cutting cutting speeds..." speeds..." speeds..." on on on which, which, which, in in in 1931, 1931, took out a German patent, assumes that "at a certain cutting speed (5-10 times higher than than in in in conventional conventional conventional machining), machining), machining), the the the chip chip chip removal removal removal temperature temperature temperature at at at the the the cutting cutting cutting edge edge will start to decrease...".See fig.6. Fig.6 chip removal temperature as a result of the cutting speed Given Given the the the conclusion:" ... conclusion:" ... seems seems to to to give give give a a a chance chance chance to to to improve improve improve productivity productivity productivity in in machining with conventional tools at high cutting speeds..." Modern research, unfortunately, has not been able to verify this theory totally. There is a relative decrease of the temperature at the cutting edge that starts at certain cutting speeds for different materials. The decrease is small for steel and cast iron. But larger for aluminum and other non-ferrous metals. The definition of HSM must be based on other factors. Given Given today's today's today's technology, technology, technology, "high "high "high speed" speed" speed" is is is generally generally generally accepted accepted accepted to to to mean mean mean surface surface speeds between 1 and 10 kilometers perminute, or roughly 3 300 to 33 000 feet per minute. Speeds above 10 km/min are in the ultra-high speed category, and are largely the realm of experimental metal cutting. Obviously, the spindle rotations required to achieve these surface cutting speeds are directly related to the diameter of the tools being being used. used. used. One One One trend trend trend which which which is is is very very very evident evident evident today today today is is is the the the use use use of of of very very very large large large cutter cutter diameters for these applications - and this has important implications for tool design. There are many opinions, many myths and many different ways to define HSM. Maintenance and troubleshooting Maintenance for a horizontal MC The The following following following is is a a list list list of of of required required required regular regular regular maintenance maintenance for for a a a Horizontal Horizontal Machining Center as shown in fig.7. Listed are the frequency of service, capacities, and type of fluids required. These required specifications must be followed in order to keep your machine in good working order and protect your warranty. Fig. 7 horizontal machining center Daily Top Top off off off coolant coolant coolant level level level every every every eight eight eight hour hour hour shift shift shift (especially (especially (especially during during during heavy heavy heavy TSC TSC usage). Check way lube lubrication tank level. Clean chips from way covers and bottom pan. Clean chips from tool changer. Wipe spindle taper with a clean cloth rag and apply light oil. Weekly • Check for proper operation of auto drain on filter regulator. See fig. 8 Fig. 8 way lube and pneumatics On machines with the TSC option, clean the chip basket on the coolant tank. Remove the tank cover and remove any sediment inside the tank. Be careful to disconnect the coolant pump from the controller and POWER OFF the control before working on the coolant tank. Do this monthly for machines without the TSC option. Check air gauge/regulator for 85 psi. For For machines machines machines with with with the the the TSC TSC TSC option, option, option, place place place a a a dab dab dab of of of grease grease grease on on on the the the V-flange V-flange V-flange of of tools. Do this monthly for machines without the TSC option. Clean exterior surfaces with mild cleaner. DO NOT use solvents. Check the hydraulic counterbalance pressure according to the machine's specifications. Place a dab of grease on the outside edge of the fingers of the tool changer and run through all tools". Monthly Check oil level in gearbox. Add oil until oil begins dripping from over flow tube at bottom of sump tank. Clean pads on bottom of pallets. Clean Clean the the the locating locating locating pads pads pads on on on the the the A-axis A-axis A-axis and and and the the the load load load station. station. station. This This This requires requires removing the pallet. • Inspect Inspect way way way covers covers covers for for for proper proper proper operation operation operation and and and lubricate lubricate lubricate with with with light light light oil, oil, oil, if if necessary. Six months Replace coolant and thoroughly clean the coolant tank. Check all hoses and lubrication lines for cracking. Annually • Replace the gearbox oil. Drain the oil from the gearbox, and slowly refill it with 2 quarts of Mobil DTE 25 oil. • Check oil filter and clean out residue at bottom for the lubrication chart. Replace air filter on control box every 2 years. Mineral Mineral cutting cutting cutting oils oils oils will will will damage damage damage rubber rubber rubber based based based components components components throughout throughout throughout the the machine. Troubleshooting This section is intended for use in determining the solution to a known problem. Solutions Solutions given given given are are are intended intended intended to to to give give give the the the individual individual individual servicing servicing servicing the the the CNC CNC CNC a a a pattern pattern pattern to to follow in, first, determining the problem's source and, second, solving the problem. Use common sense Many Many problems problems problems are are are easily easily easily overcome overcome overcome by by by correctly correctly correctly evaluating evaluating evaluating the the the situation. situation. situation. All All machine operations are composed of a program, tools, and tooling. You must look at all three before blaming one as the fault area. If a bored hole is chattering because of an overextended boring bar, don't expect the machine to correct the fault. Don't Don't suspect suspect suspect machine machine machine accuracy accuracy accuracy if if if the the the vise vise vise bends bends bends the the the part. part. part. Don't Don't Don't claim claim claim hole hole miss-positioning if you don't first center-drill the hole. Find the problem first Many Many mechanics mechanics mechanics tear tear tear into into into things things things before before before they they they understand understand understand the the the problem, problem, problem, hoping hoping that it will appear as they go. We know this from the fact that more than half of all warranty warranty returned returned returned parts parts parts are are are in in in good good good working working working order. order. If If the the the spindle spindle spindle doesn't doesn't doesn't turn, turn, remember remember that that that the the the spindle spindle spindle is is is connected connected connected to to to the the the gear gear gear box, box, box, which which which is is is connected connected connected to to to the the spindle spindle motor, motor, motor, which which which is is is driven driven driven by by by the the the spindle spindle spindle drive, drive, drive, which which which is is is connected connected connected to to to the the the I/O I/O BOARD, BOARD, which which which is is is driven driven driven by by by the the the MOCON, MOCON, MOCON, which which which is is is driven driven driven by by by the the the processor. processor. processor. The The moral here is doing replace the spindle drives if the belt is broken. Find the problem first; don't just replace the easiest part to get to. Don tinker with the machine There are hundreds of parameters, wires, switches, etc., that you can change in this machine. Don't start randomly changing parts and parameters. Remember, there is a good chance that if you change something, y ou will incorrectly install it or break you will incorrectly install it or break something else in the process6. Consider for a moment changing the processor's board. First, you have to download all parameters, remove a dozen connectors, replace the board, board, reconnect reconnect reconnect and and and reload, reload, reload, and and and if if if you you you make make make one one one mistake mistake mistake or or or bend bend bend one one one tiny tiny tiny pin pin pin it it WON'T WORK. You always need to consider the risk of accidentally damaging the machine anytime you work on it. It is cheap insurance to double-check a suspect part before physically changing it. The less work you do on the machine the better. 。
机械加工刀具中英文对照外文翻译文献
(文档含英文原文和中文翻译)中英文对照外文翻译英文原文Selection of optimum tool geometry and cutting conditionsusing a surface roughness prediction model for end milling Abstract Influence of tool geometry on the quality of surface produced is well known and hence any attempt to assess the performance of end milling should include the tool geometry. In the present work, experimental studies have been conducted to see the effect of tool geometry (radial rake angle and nose radius) and cutting conditions (cutting speed and feed rate) on the machining performance during end milling of medium carbon steel. The first and second ordermathematical models, in terms of machining parameters, were developed for surface roughness prediction using response surface methodology (RSM) on the basis of experimental results. The model selected for optimization has been validated with the Chi square test. The significance of these parameters on surface roughness has been established with analysis of variance. An attempt has also been made to optimize the surface roughness prediction model using genetic algorithms (GA). The GA program gives minimum values of surface roughness and their respective optimal conditions.1 IntroductionEnd milling is one of the most commonly used metal removal operations in industry because of its ability to remove material faster giving reasonably good surface quality. It is used in a variety of manufacturing industries including aerospace and automotive sectors, where quality is an important factor in the production of slots, pockets, precision moulds and dies. Greater attention is given to dimensional accuracy and surface roughness of products by the industry these days. Moreover, surface finish influences mechanical properties such as fatigue behaviour, wear, corrosion, lubrication and electrical conductivity. Thus, measuring and characterizing surface finish can be considered for predicting machining performance.Surface finish resulting from turning operations has traditionally received considerable research attention, where as that of machining processes using multipoint cutters, requires attention by researchers. As these processes involve large number of parameters, it would be difficult to correlate surface finish with other parameters just by conducting experiments. Modelling helps to understand this kind of process better. Though some amount of work has been carried out to develop surface finish prediction models in the past, the effect of tool geometry has received little attention. However, the radial rake angle has a major affect on the power consumption apart from tangential and radial forces. It also influences chip curling and modifies chip flow direction. In addition to this, researchers [1] have also observed that the nose radius plays a significant role in affecting the surface finish. Therefore the development of a good model should involve the radial rake angle and nose radius along with other relevant factors.Establishment of efficient machining parameters has been a problem that has confronted manufacturing industries for nearly a century, and is still the subject of many studies. Obtaining optimum machining parameters is of great concern in manufacturing industries, where the economy of machining operation plays a key role in the competitive market. In material removal processes, an improper selection of cutting conditions cause surfaces with high roughness anddimensional errors, and it is even possible that dynamic phenomena due to auto excited vibrations may set in [2]. In view of the significant role that the milling operation plays in today’s manufacturing world, there is a need to optimize the machining parameters for this operation. So, an effort has been made in this paper to see the influence of tool geometry (radial rake angle and nose radius) and cutting conditions (cutting speed and feed rate) on the surface finish produced during end milling of medium carbon steel. The experimental results of this work will be used to relate cutting speed, feed rate, radial rake angle and nose radius with the machining response i.e. surface roughness by modelling. The mathematical models thus developed are further utilized to find the optimum process parameters using genetic algorithms.2 ReviewProcess modelling and optimization are two important issues in manufacturing. The manufacturing processes are characterized by a multiplicity of dynamically interacting process variables. Surface finish has been an important factor of machining in predicting performance of any machining operation. In order to develop and optimize a surface roughness model, it is essential to understand the current status of work in this area.Davis et al. [3] have investigated the cutting performance of five end mills having various helix angles. Cutting tests were performed on aluminium alloy L 65 for three milling processes (face, slot and side), in which cutting force, surface roughness and concavity of a machined plane surface were measured. The central composite design was used to decide on the number of experiments to be conducted. The cutting performance of the end mills was assessed using variance analysis. The affects of spindle speed, depth of cut and feed rate on the cutting force and surface roughness were studied. The investigation showed that end mills with left hand helix angles are generally less cost effective than those with right hand helix angles. There is no significant difference between up milling and down milling with regard tothe cutting force, although the difference between them regarding the surface roughness was large. Bayoumi et al.[4] have studied the affect of the tool rotation angle, feed rate and cutting speed on the mechanistic process parameters (pressure, friction parameter) for end milling operation with three commercially available workpiece materials, 11 L 17 free machining steel, 62- 35-3 free machining brass and 2024 aluminium using a single fluted HSS milling cutter. It has been found that pressure and friction act on the chip – tool interface decrease with the increase of feed rate and with the decrease of the flow angle, while the cutting speed has a negligible effect on some of the material dependent parameters. Process parameters are summarized into empirical equations as functions of feed rate and tool rotation angle for each work material. However,researchers have not taken into account the effects of cutting conditions and tool geometry simultaneously; besides these studies have not considered the optimization of the cutting process.As end milling is a process which involves a large number f parameters, combined influence of the significant parameters an only be obtained by modelling. Mansour and Abdallaet al. [5] have developed a surface roughness model for the end milling of EN32M (a semi-free cutting carbon case hardening steel with improved merchantability). The mathematical model has been developed in terms of cutting speed, feed rate and axial depth of cut. The affect of these parameters on the surface roughness has been carried out using response surface methodology (RSM). A first order equation covering the speed range of 30–35 m/min and a second order equation covering the speed range of 24–38 m/min were developed under dry machining conditions. Alauddin et al. [6] developed a surface roughness model using RSM for the end milling of 190 BHN steel. First and second order models were constructed along with contour graphs for the selection of the proper combination of cutting speed and feed to increase the metal removal rate without sacrificing surface quality. Hasmi et al. [7] also used the RSM model for assessing the influence of the workpiece material on the surface roughness of the machined surfaces. The model was developed for milling operation by conducting experiments on steel specimens. The expression shows, the relationship between the surface roughness and the various parameters; namely, the cutting speed, feed and depth of cut. The above models have not considered the affect of tool geometry on surface roughness.Since the turn of the century quite a large number of attempts have been made to find optimum values of machining parameters. Uses of many methods have been reported in the literature to solve optimization problems for machining parameters. Jain and Jain [8] have used neural networks for modeling and optimizing the machining conditions. The results have been validated by comparing the optimized machining conditions obtained using genetic algorithms. Suresh et al. [9] have developed a surface roughness prediction model for turning mild steel using a response surface methodology to produce the factor affects of the individual process parameters. They have also optimized the turning process using the surface roughness prediction model as the objective function. Considering the above, an attempt has been made in this work to develop a surface roughness model with tool geometry and cutting conditions on the basis of experimental results and then optimize it for the selection of these parameters within the given constraints in the end milling operation.3 MethodologyIn this work, mathematical models have been developed using experimental results with the help of response surface methodolog y. The purpose of developing mathematical models relating the machining responses and their factors is to facilitate the optimization of the machining process. This mathematical model has been used as an objective function and the optimization was carried out with the help of genetic algorithms.3.1 Mathematical formulationResponse surface methodology (RSM) is a combination of mathematical and statisticaltechniques useful for modelling and analyzing the problems in which several independent variables influence a dependent variable or response. The mathematical models commonly used are represented by:where Y is the machining response, ϕ is the response function and S, f , α, r are milling variables and ∈ is the error which is normally distributed about the observed response Y with zero mean.The relationship between surface roughness and other independent variables can be represented as follows, where C is a constant and a, b, c and d are exponents.To facilitate the determination of constants and exponents, this mathematical model will have to be linearized by performing a logarithmic transformation as follows:The constants and exponents C, a, b, c and d can be determined by the method of leastsquares. The first order linear model, developed from the above functional relationship using least squares method, can be represented as follows:where Y1 is the estimated response based on the first-order equation, Y is the measured surface roughness on a logarithmic scale, x0 = 1 (dummy variable), x1, x2, x3 and x4 arelogarithmic transformations of cutting speed, feed rate, radial rake angle and nose radius respectively, ∈ is the experimental error and b values are the estimates of corresponding parameters.The general second order polynomial response is as given below:where Y2 is the estimated response based on the second order equation. The parameters, i.e. b0, b1, b2, b3, b4, b12, b23, b14, etc. are to be estimated by the method of least squares. Validity of the selected model used for optimizing the process parameters has been tested with the help of statistical tests, such as F-test, chi square test, etc. [10].3.2 Optimization using genetic algorithmsMost of the researchers have used traditional optimization techniques for solving machining problems. The traditional methods of optimization and search do not fare well over a broad spectrum of problem domains. Traditional techniques are not efficient when the practical search space is too large. These algorithms are not robust. They are inclined to obtain a local optimal solution. Numerous constraints and number of passes make the machining optimization problem more complicated. So, it was decided to employ genetic algorithms as an optimization technique. GA come under the class of non-traditional search and optimization techniques. GA are different from traditional optimization techniques in the following ways:1.GA work with a coding of the parameter set, not the parameter themselves.2.GA search from a population of points and not a single point.3.GA use information of fitness function, not derivatives or other auxiliary knowledge.4.GA use probabilistic transition rules not deterministic rules.5.It is very likely that the expected GA solution will be the global solution.Genetic algorithms (GA) form a class of adaptive heuristics based on principles derived from the dynamics of natural population genetics. The searching process simulates the natural evaluation of biological creatures and turns out to be an intelligent exploitation of a random search. The mechanics of a GA is simple, involving copying of binary strings. Simplicity of operation and computational efficiency are the two main attractions of the genetic algorithmic approach. The computations are carried out in three stages to get a result in one generation or iteration. The three stages are reproduction, crossover and mutation.In order to use GA to solve any problem, the variable is typically encoded into a string (binary coding) or chromosome structure which represents a possible solution to the given problem. GA begin with a population of strings (individuals) created at random. The fitness of each individual string is evaluated with respect to the given objective function. Then this initial population is operated on by three main operators – reproduction cross over and mutation – to create, hopefully, a better population. Highly fit individuals or solutions are given the opportunity to reproduce by exchanging pieces of their genetic information, in the crossover procedure, with other highly fit individuals. This produces new “offspring” solutions, which share some characteristics taken from both the parents. Mutation is often applied after crossover by altering some genes (i.e. bits) in the offspring. The offspring can either replace the whole population (generational approach) or replace less fit individuals (steady state approach). This new population is further evaluated and tested for some termination criteria. The reproduction-cross over mutation- evaluation cycle is repeated until the termination criteria are met.中文翻译选择最佳工具,几何形状和切削条件利用表面粗糙度预测模型端铣刀具几何形状对工件表面质量产生的影响是人所共知的,因此,任何成型面端铣摘要: 刀具几何形状对工件表面质量产生的影响是人所共知的,因此,任何成型面端铣设计应包括刀具的几何形状。
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数控机床刀具设计中英文资料英语原文:Design Of Tool Machine PropResearch significanceThe original knife machine control procedures are designed individually, not used tool management system, features a single comparison, the knife only has to find the tool knife, knife positioning the shortest path, axis tool change, but does not support large-scale tool.Automatic knife in the knife election, in the computer memory knife-election on the basis of using the Siemens 840 D features, and the election procedures knife more concise, and complete the space Daotao View. ATC use the knife rapid completion of STEP-7 programming, and have been tested in practice. In the positioning of the knife, PLC controlled modular design method, which future production of similar machines will be very beneficial, it is easy to use its other machine. Automatic tool change systems will be faster growth, reduced tool change time, increase the positioning accuracy tool is an important means to help NC technology development.Tool and inventory components of modern production is an important link in the management, especially for large workshop D features, and the election procedures knife more concise, and complete the space Daotao View. ATC use the knife rapid completion of STEP-7 programming, and have been tested in practice. In the positioning of the knife, PLC controlled modular design method, which future production of similar machines will be very beneficial, it is easy to use its oth management. The traditional way of account management, and low efficiency, high error rate, and not sharing information and data, tools and the use of state can not track the life cycle, are unable to meet the current information management needs. With actual production, we have to establish a workshop tool for the three-dimensional tool storage system to meet the knife workshop with auxiliary storage and management needs.The system uses optimization technology, a large number of computer storage inventory information, timely, accurate, and comprehensive tool to reflect the inventory situation. The entire system uses a graphical interface, man-machine dialogue tips from the Chinese menu, select various functions can be realized and the importation of all kinds of information. Management system using online help function. Through the workshop management, network management and sharing of information. Have automated inventory management, warehousing management tool, a tool for the management and statistical functions.1.System components and control structureThe entire system, including the structure and electrical machinery control systems.1.1.1Mechanical structure and working principleTool from the stent, drive, drive system, Turret, shielding, control system, and electrical components. Support from the column, beam, the upper and lower guide Central track, and track support component.1) Drive for the system chosen VVVF method. Cone used brake motors, with VVVF by Cycloid reducer through sprocket drive.2) Drag a variable frequency drive system and control technology. VVVF adopted, will speed drive shaft in the normal range adjustment to control the speed rotary turret to 5 ~ 30mm in, the drive shaft into two, two under through sprocket, the two profiled rollers Chain driven rotating shelves. Expansion chain adopted by the thread tight regulation swelling, swelling the regular way. - Conditi D features, and the election procedures knife more concise, and complete the space Daotao View. ATC use the knife rapid completion of STEP-7 programming, and have been tested in practice. In the positioning of the knife, PLC controlled modular design method, which future production of similar machines will be very beneficial, it is easy to use its at six other Des V oeux a knife, can be categorized with some of knife auxiliary equipment, such as bits, such as turning tools.1.1.2.Electrical Control SystemThis tool storage systems is the main electrical control their shelves for operational control and position control. Operational control equipment, including operation of the start of braking control. Position Control is the main location and address of the shelves for testing.1) Electric Transmission horizontal rotary tool storage systems are the mechanical movements are repeated short-term work system. And the run-time system needs some speed, speed transmission needs, the system will use VVVF method can be used simple structure, reliable operation of the motor and frequency inverter.2) Control of the system is divided into two kinds of manual control and automatic control, manual control as a general reserve and debugging methods of work; ways to the system control computer (IPC) and the control unit (inverter contactor , etc.) consisting of a control system.3) location and positioning accuracy of the system automatically identify the site and location using a detection device tion, timely, accurate, and comprehensive tool to reflect the inventory situation. The entire system uses a graphical interface, man-machine dialogue tips from the Chinese menu, select various functions can be realized and the importation of all kinds of information. Management system using online help function. Through the workshop management, network management and sharing of information. Have automated inventory management, warehousing management tool, a tool for the management and statistical fu as proximity switches, relays through the plate-point isolation and the number plate recorded close to the switching signal acquisition and operation of Hutchison with a Optimal Path addressable identify the current location and shelves of the purpose of the shelf location. In order to enable a more accurate positioning system, adopted two photoelectric switches, to detect the two shelves of the two films.1.2.The functions of the knifeknife The is the role of reserves a certain number of tools, machine tool spindle in hand to achieve the fungibility a disc sc knife in the library with discoid knife, cutting tool along See how vertical arrangement (including radial and axial from knife from knife), along See how radial array into acute or arranged in the form of the knife. Simple, compact, more applications, but are ring-cutter, low utilization of space. Figure 2.7 a) to c). D features, and the election procedures knife more concise, and complete the space Daotao View. ATC use the knife rapid completion of STEP-7 programming, and have been tested in practice. In the positioning of the knife, PLC controlled modular design method, which future production of similar machines will be very beneficial, it is easy to use its. If the knife cutter knife is the type of library, the chain knives, and other means, in the form of the knifeand capacity according to the Machine Tool to determine the scope of the process.s, but are ring-cutter, low utilization of space. Figure 2.7 a) to c). D features, and the election procedures knife more concise, and com mon typesThe knife is a tool storage devices, the common knife mainly in the following forms:(1) the turret knifeIncluding the first level turret vertical turret and the first two, see Figure 2.6 a) and b):(2) the disc cutterDisc knife in the library with discoid knife, cutting tool along See how vertical arrangement (includingradial and axial from knife from knife), along See how radial array into acute or arranged in the form of theknife. Simple, compact, more applications, but are ring-cutter, low utilization of space. Figure 2.7 a) to c).D features, and the election procedures knife more concise, and complete the space Daotao View. ATC use theknife rapid completion of STEP-7 programming, and have been tested in practice. In the positioning of theknife, PLC controlled modular design method, which future production of similar machines will be verybeneficial, it is easy to use its. If the knife storage capacity must be increased to increase the diameter of theknife, then the moment of inertia also increased correspondingly, the election campaign long knife. Toolnumber not more than 32 general. Cutter was multi-loop order of the space utilization knife, but inevitablygiven the knife from complex institutions, applicable to the restricted space Machine Tool storage capacity andmore occasions. Two-disc structure is two smaller capacity knife on both sides of the sub-spindle place, morecompact layout, the number ofapply to small and medium-sizedprocessing center.(3) the chain knife Includingsingle-and multi-ring chain ringchain, chain link can take many forms change, see Figure 2.8 a) to c), the basic structure shown in Figure 2. 8 doFeatures: knife apply to the larger capacity of the occasion, the space of the small number of generally applicable to the tool in the 30-120. Only increase the length of the chain tool will increase the number should not be increased circumferential speed of its moment of inertia of the knife does not increase the disc as large.(4) linear combination knife and the knife libraryThe linear knife simple structure in Figure 2.9, tool single order, the capacity of small knife, used for CNC lathe and drill press on. Because the location of fixed knife, ATC completed action by the spindle without manipulator. The cutter knife is generally the turret combination turret with a combination of the disc cutter knife and the chain combination. Every single knife the knife certificates of smaller, faster tool change. There are also some intensive drum wheel, and the lattice-type magazine for the knife, the knife-intensive though.Small footprint, but because of structural constraints, basically not used for single processing center, the concentration used for FMS for the knife system.1.4 Tool storage capacityTool storage capacity of the first to consider the needs of processing, from the use of point of view,generally 10 to 40 knives, knife will be the utilization of the high, and the structure is compact.1.5 Tool options(1) choose to order processing tool according to the order, followed Add to the knife every knife in the Block. Each tool change, the order of rotation of a cutter knife on location, and remove the need knives, has been used by the cutter knife can be returned to the original Block, can also order Add Block, a knife. However, as the knife in the tool in different processes can not be repeated use of the knife must increase the capacity and lower utilization rate.(2) most of the arbitrary choice of the current system of using arbitrary NC election knives, divided into Daotao coding, coding and memory-cutter, three. Daotao coding tool code or knives or Daotao need to install the code used to identify, in accordance with the general principle of binary coding coding. Tool knife election coding method uses a special knife handle structure, and each of the coding tool. Each of the tool has its own code, thereby cutting tool can be in different processes repeatedly used, not to replace the tool back at the original knife, the knife capacity can be reduced accordingly. Memory-election this paper knife, in this way can knives and knife in the position corresponding to the Daotao memory of the PLC in the NC system, no matter which tool on the Inner knife, tool information is always there in mind, PLC . On the knife with position detection devices, will be the location of each Daotao. This tool can be removed and sent back to arbitrary. On the knife is also a mechanical origin, every election, the nearest knife selection.1.6.Control of the knife(1) the knife as a system to control the positioning axis. In the ladder diagram in accordance with the instructions for computing T code comparison of the output angle and speed of instructions to the knife the knife servo drive servo motor. Tool storage capacity, rotation speed, and / deceleration time, and other system parameters can be set in such a manner free from any outside influence positioning accurate and reliable but the cost is higher.(2) knife from the hydraulic motor drives, fast / slow the points, with proximity switches count and positioning. In comparison ladder diagram of the current storage system knife (knife spindle) and goals knife (pre-knife) and computing, then output rotation instructions, judging by the shortest path rotation in place. This approach requires sufficient hydraulic power and electromagnetic valve knife the rotational speed can be adjusted through the throttle. But over time may be oily hydraulic, oil temperature and environmental factors impact the change in velocity and accuracy. Not generally used in large and medium-sized machine tool change frequently.(3) the knife from AC asynchronous motor driven cam mechanism (Markov institutions), with proximity switches count, which means stable operation, and generally accurate and reliable positioning cam used in conjunction with a mechanical hand, ATC fast-positioning.2. ATC, the main types, characteristics, and the scope of application2.1 Auto Rotary ToolRotary Tool automatically on the use of CNC machine tool is a simpleinstallation of automatic tool change, the Quartet and 47.60 Turret Tool various forms, such as rotary turret were installed on four, six or more of the Tool , NCinstructions by ATC. Rotary Tool has two vertical and horizontal, relatively simple structure, applicable to economic CNC lathe.Rotary Tool in the structure must have good strength and stiffness, resistance to bear rough Cutting Tool in the cutting force and reduce the role of deformation and improve processing accuracy. Rotating Tool to choose reliable positioning programme structure and reasonable position, in order to ensure that each rotary turret to a higher position after repeated positioning accuracy (typically 0.001 to 0.005mm). Figure 2.1 shows the spiral movements of the Quartet Turret.Auto Rotary Tool in the simplest of ATC, is 180 º rotary ATC devices, as shown in Figure 2.2 ATC instructions received, the machine control system put ATC spindle control to the designated location at the same time, the tool movement to the appropriate location, ATC, with the rotary axis and at the same time, the knives matching tool; drawbars from Spindle Cutting Tools rip, ATC, will be the tool from their position removed; ATC, 180 º rotary tool spindle and the tool and tool away; ATC, the Rotary At the same time, thetool refocusing its position to accept Spindle removed from the cutting tool; Next, ATC, will be replaced with the cutter knives were unloaded into the spindle and tool: Finally, back to the original ATC, "standby" position. At this point, ATC completed procedures to continue to run. This ATC, the main advantage of simple structure,the less movement, fast tool change. The main disadvantage is that knives must be kept in parallel with the axis of the plane, and after the home side compared to the tool, chip and liquid-cutting knife into the folder, it is necessary to the tool plus protection. Cone knife folder on the chip will cause ATC error, or even damage knife folders, and the possibility of spindle. Some processing centre at the transfer, and the tool side. When the ATC command is called, the transfer-cutter knives will be removed, the machine go forward, and positioning with the ATC, in line with the position. 180 º "Rotary ATC devices can be used horizontal machine, can also be used for vertical machining centers.2. 2 ATC head-turret installedWith rotating CNC machine tool often used such ATC devices, with a few turret head spindle, each with a spindle on both knives, the first tower interim process can be automatic tool change-realization. The advantage is simple structure, tool change time is short, only about 2 s. However, due to spatial constraints, the number of spindle can not be too much, usually only apply to processes less, not to high precision machine tools, such as the NC drill, such as CNC milling machine. In recent years there has been a mechanical hand and the turret head with a knife for the automatic tool change ATC devices, as shown in Figure 2.3. It is in fact a turret head ATC, and the knife-ATC device combination. The principle is as follows:5 turret on the first two tool spindle 3 and 4, when using the tool spindle 4 processing tool, the manipulator 2 will be the next step to the need for the tool does not work on the tool spindle 3 until after the completion of this process , the first rotary turret 180 º, ATC completed. ATC most of their time and processing time coincidence, the only real tool change time turret transposition of the first time, this approach mainly used for ATC and NC NC drilling file bed.2. 3.Daidao system for the automatic tool changeFigure 2.4 shows the knife and the whole machine tool CNC machine tools for the appearance of Fig. Figure 2.5 shows the knife and split-type machine to the appearance of CNC machine tool plans.At this point, knife storage capacity, a heavier tool can, and often additional transport unit to complete the knife between the spindle and cutting tool transport.Daidao the knife from the ATC, the election knives, automatic loading and unloading machine tool and tool exchange institutions (manipulator), composed of four parts, used widely.Tool Automatic Tool Change When CNC tool code and the code in line with directives of the tool selected, the rotary cutter knives will be sent to the ATC position, waiting to grab manipulator. Random knife election is the advantage of the cutter knife in the order has nothing to do with the processing sequence, the same tool can be used repeatedly. Therefore, the relatively small number of knives, knife the corresponding smaller. Random elections knife on the tool must be coded to identify. There are three main coding.1. Tool coding. Adopt special knife handle structure coding, the drawbars on the knife handle back-endpackages such as spacing of the coding part of the lock-nut fixed. Coding diameter ring diameter of a size two,respectively, said that binary "1" and "0" to the two rings are different, can be a series of code. For example, there are six small diameter of the ring can be made to distinguish between 63 (26-1 = 63) of the coding tool. All of 0 normally not allowed to use the the manipulator system, the whole process more complicated ATC. We must first used in the processing of all installed in the standard tool on the knife handle in the machine outside the pre-size, according to a certain way Add to the knife. ATC, selected first in the knife knife, and then from ATC, from the knife from the knife or spindle, exchange, the new knife into the spindle, the old knife back into the knife.ATC, as the former two knives to accommodate a limited number can not be too many, can not meet the needs of complex parts machining, CNC machine tool Automatic Tool Change Daidao the use of the automatic tool change devices. The knife has more capacity, both installed in the spindle box side or above. As for the automatic tool change Daidao device CNC machine tool spindle box only a spindle, spindle components to high stiffness to meet the machining requirements. The number of establishments in larger knife, which can meet the more complex parts of the machining processes, significantly improving productivity. Daidao system for the automatic tool change applied to drilling centres and CNC machining centers. The comparison drawn Daidao automatic tool change system is the most promising.3.PLC control of the knife random mode of election3. 1Common methods of automatic election knifeAutomatic control of the knife CNC refers to the system after the implementation of user instructions onthe knife library automation process, including the process to find knives and automatic tool change [(63,71]. CNC Machining Center device (CNC) directive issued by the election knife , a knife, the tool required to take the knife position, said the election automatic knife. automatically elected knife There are two ways: randomsequence election knives and knife election method.3.1.1 order election knifeTool Selection order is the process tool according to the sequence of the insert knife, the use of knives in order to take place, used knives back at the original knife, can also order Add Block, a knife. In this way, no need Tool identification devices, and drive control is a relatively simple, reliable and can be used directly from the points of the knife machinery to achieve. But the knives in each of the tool in different processes can not be reused, if the tool is installed in accordance with the order of the knife, there will be serious consequences. Theneed to increase the number of knives and knife the capacity of the tool and reduce the utilization of the knife.3.1.2Random election knifeRandom election under the knife is arbitrary instructions to select the required tools, then there must be tool identification devices. Tool knife in the library do not have the processing in accordance with the order of the workpiece can be arbitrary storage. Each of the tool (or knife blocks) are for a code, automatic tool change, the rotary cutter, every tool have been the "tool identification device" acceptable identification. When CNCtool code and the code in line with directives of the tool selected, the rotary cutter knives will be sent to the ATC position, waiting to grab manipulator. Random knife election is the advantage of the cutter knife in the order has nothing to do with the processing sequence, the same tool can be used repeatedly. Therefore, the relatively small number of knives, knife the corresponding smaller. Random elections knife on the tool must be coded to identify. There are three main coding.1. Tool coding. Adopt special knife handle structure coding, the drawbars on the knife handle back-end packages such as spacing of the coding part of the lock-nut fixed. Coding diameter ring diameter of a size two, respectively, said that binary "1" and "0" to the two rings are different, can be a series of code. For example, there are six small diameter of the ring can be made to distinguish between 63 (26-1 = 63) of the coding tool. All of 0 normally not allowed to use the code, to avoid the cutter knife Block did not confuse the situation.2. Knife Block coding. On the knife Block coding, coding tool, and tool into line with the number of knives in the Block. ATC knife when the rotation, so that each knife seats followed through knowledge knife, knife found blocks, knives stopped the rotation. At this time there is no knife handle encoding part of the knife handle simplified.3. Annex coding methods. This style of coding keys, coded cards, coding and coding-disc, which is the most widely used coding keys. First to knives are attached to a tool of the show wrapped coding keys, and when the cutter knife to the store at knife in, so put the number of keys to remember knife Block Road, will be inserted into key to the coding Block next to the key hole in the seat for the knife to the numbers. ConclusionFocused on in today's manufacturing environment tool storage and management of new models and methods, practical application of good results in systems integration and optimization, and other aspects of operations will be further explored, so that it has a higher theoretical and practical level.译文:机床刀具设计课题研究意义机床原来的刀库控制程序是单独设计的,没有采用刀具管理系统,功能也比较单一,只实现了刀库刀具的找刀、刀库最短路径定位、主轴换刀,而且不支持大型刀具。