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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）。

数控铣床外文翻译（汉语）

数控铣床外文翻译（汉语）第一篇：数控铣床外文翻译(汉语)视觉辅助数控铣削加工轨迹的生成视觉辅助数控铣削加工轨迹的生成随着计算机技术的高速发展,从根本上改变传统制造业,工业发达国家花了大笔的钱在现代制造技术的研究与开发,创建一个新的模型。

在现代制造系统,数控技术的关键技术,结合微电子、计算机、信息处理、自动检测、自动控制,比如集成先进的、高精度、高效率、灵活的自动化等特点,制造业灵活的自动化、集成、智能起着关键性的作用。

目前,数控技术正在经历一个根本性的改变,从一个特殊的闭环控制模式为通用的实时动态打开所有的闭环控制模式。

在综合的基础上,CNC系统的超薄、超轻;聪明的基础上,综合计算机、多媒体、模糊控制、神经网络和其他技术的学科,数控系统以实现高速、高精度、高效率控制、自动处理可以修改调节补偿和参数进行在线智能故障诊断和治疗的网络基于CAD / CAM和数控系统集成为一台计算机网络,使中央政府集中控制该集团的控制过程。

长期以来，数控系统为传统封闭式体系结构，但只能作为非智能数控机床控制器。

基于经验的过程变量是预先固定参数的形式。

处理前是由专人或通过CAD / CAM及自动编程系统编写实际的处理程序。

CAD / CAM与数控系统没有反馈控制环节，整个制造过程是一个封闭的数控开环执行机构。

在一个复杂的和环境变化的情况下的加工过程中，加工刀具的构成，工件材料，主轴转速，进给速度，刀具路径，切削深度，走刀次数和粗糙度等其它工艺参数，并不是在外部干扰和实时动态随机因素的环境情况下得到的。

不能通过随机修正反馈控制系统的CAD / CAM的设置数量。

这反而影响到数控加工效率和产品的质量。

显然，传统的固定数控系统的控制模式和封闭式体系结构，限制了数控到更智能化的控制变量的发展，已经不能满足日益复杂的制造过程。

因此，数控技术的潜在的变革是不可避免的。

CAD/CAM软件是一种网状交互型的计算机编程系统，它用来检测、处理和控制数据流的制造。

数控机床改造中英文对照外文翻译文献

中英文对照外文翻译文献(文档含英文原文和中文翻译)原文:The Numerical Control Engine Bed TransformsHarvey B.M ackey First numerical control system development summary brief hi story and tendency.In 1946 the first electronic accounting machine was born the world,this indicated the humanity created has been possib le to strengthen and partially to replace the mental labor the tool. It with the humanity these which in the agricultu re, the industry society created only is strengthens the phy sical labor the tool to compare, got up the quantitive leap ,entered the information society for the humanity to laythe foundation.After 6 years, in 1952, computer technology applied to t he engine bed , the first numerical control engine bed were born in US. From this time on, the traditional engine bed has had the archery target change. Since nearly half centu ry, the numerical control system has experienced two stages and six generation of development.1.1 Numerical control (NC) stage (1952 ~ 1970)The early computer operating speed is low, was not big to then science computation and the data processing influence ,but could not adapt the engine bed real-time control reques t.The people can not but use numeral logic circuit "to buil d"to become an engine bed special purpose computer to take the numerical control system, is called the hardware connecti onnumerical control (HARD-WIRED NC), Jian Chengwei numerical c ontrol (NC). Along with the primary device development, this stage has had been through repeatedly three generations, na mely 1952 first generation of -- electron tube; 1959 second generation of -- transistor; 1965 third generation -- small scale integration electric circuit.1.2 Computer numerical control (CNC) stage (in 1970 ~ presen t)In 1970, the general minicomputer already appeared and th e mass production. Thereupon transplants it takes the numeric al control system the core part, from this time on entered the computer numerical control (CNC) the stage ("which should have computer in front of the general" two characters to ab breviate). In 1971, American INTEL Corporation in the world first time the computer two most cores part -- logic units and the controller, used the large scale integrated circuit technology integration on together the chip, called it the m icroprocessor (MICROPROCESSOR), also might be called the centr al processing element (to be called CPU).The microprocessor is applied to 1974 in the numerical c ontrol system. This is because minicomputer function too stro ng, controlled an engine bed ability to have wealthily (therefore once uses in controlling the multi- Taiwan engine bed at that time, called it group control), was inferior to use d the microprocessor economy to be reasonable. Moreover then small machine reliability was not ideal. The early microproce ssor speed and the function although insufficiently are also high, but may solve through the multi-processor structure. Because the microprocessor is the general-purpose calculator core part, therefore still was called the computer numerical control.In 1990, PC machine (personal computer, domestic custom had called microcomputer) the performance has developed tothe very high stage, may satisfiedly take the numerical cont rol system core part the request. Thenumerical control system henceforth entered based on the PC stage. In brief, the computer numerical control stage has also experienced three generations. Namely 1970 fourth generat ion of -- minicomputer; 1974 five dynasties -- microprocessor and 1990 sixth generation -- (overseas was called PC-BASED) based on PC.Also must point out, although overseas already renamed as the computer numerical control (namely CNC).Also must point out, although overseas already renamed as the computer numerical control (namely CNC), but our countr y still the custom called the numerical control (NC). Theref ore we daily say "numerical control", the materially already was refers to "computer numerical control".1.3 the numerical control future will develop tendency1.3.1 open style continues to, to develop based on the PC sixth generation of directionThe software and hardware resources has which based on P C are rich and so on the characteristic, the more numerical controls serial production factory can step onto this path. Uses PC machine to take at least its front end machine, pr ocesses the man-machine contact surface, the programming, the association .Question and so on net correspondence, undertakes the num erical control duty by the original system. PC machine has the friendly man-machine contact surface, will popularize to all numerical controls system. The long-distance communication, the long-distance diagnosis and the service will be more common.1.3.2 approaches and the high accuracy developmentThis is adapts the engine bed to be high speed and the high accuracy direction need to develop.1.3.3 develops to the intellectualized directionAlong with the artificial intelligence in the computer do mainunceasing seepage and the development, the numerical control system intellectualized degree unceasingly will enhance.(1) applies the adaptive control technologyThe numerical control system can examine in the process some important information, and the automatic control system related parameter, achieves the improvement system running sta tus the goal.(2) introduces the expert system instruction processingThe skilled worker and expert's experience, the processing general rule and the special rule store in the system, take the craft parameter database as the strut, the establishmenthas the artificial intelligence the expert system.(3)introduces the breakdown to diagnose the expert system(4) intellectualized numeral servo driveMay through the automatic diagnosis load, but the automat ic control parameter, causes the actuation system to obtain the best movement.Second, engine bed numerical control transformation necessi ty.2.1 microscopic looks at the transformation the necessityFrom on microscopic looked below that, the numerical cont rol engine bed has the prominent superiority compared to the traditional engine bed, moreover these superiority come from the computer might which the numerical control system contain s.2.1.1 may process the traditional engine bed cannot proce ss the curve, the curved surface and so on the complex com ponents.Because the computer has the excellent operation ability, may the instant accurately calculate each coordinate axis ins tant to be supposed the movement physiological load of exerc ise, therefore may turn round thesynthesis complex curve or the curved surface.2.1.2 may realize the processing automation, moreover is the flexible automation, thus the efficiency may enhance 3 ~ 7 times compared to the traditional engine bed.Because the computer has the memory and the memory prope rty, may the procedure which inputs remember and save, thenthe order which stipulated according to the procedure automat ic carries out, thus realization automation. The numerical co ntrol engine bed so long as replaces a procedure, may reali ze another work piece processing automation, thus causes the single unit and the small batch of production can automate, therefore is called has realized "flexible automation".2.1.3 processings components precision high, size dispersion d egree small, makes the assembly to be easy, no longer needs "to make repairs".2.1.4 may realize the multi- working procedures centralism, r educes the components in engine bed between frequent transpor ting.2.1.5 has auto-alarm, the automatic monitoring, automatic comp ensation and so on the many kinds of autonomy function, thu s may realize long time nobody to safeguard the processing.2.1.6 advantage which derives by above five.For example: Reduced worker's labor intensity, saved the labor force (a person to be possible to safeguard the multi - Taiwan engine bed), reduced the work clothes, reduced the new product trial manufacturing cycle and the production cycl e, might to the market demand make rapid reaction and so o n.Above these superiority are the predecessor cannot imagine, is an extremely significant breakthrough. In addition, the en gine bed numerical control carries out FMC (flexible manufact ure unit), FMS (flexible manufacture system) as well as CIMS (computer integration manufacture system) and so on the enter prise becoming an information based society transformation foundation. The numerical control technology already became the manufacturing industry automation the core technology and the foundation technology.2.2 great watches the transformation the necessityFrom on macroscopic looked that, the industry developed c ountry armed forces, the airplane weapon industry, in the en d of the 70's, at the beginning of the 80's started the l arge-scale application numerical control engine bed. Its essen ce is, uses the information technology to the traditional in dustry (including the armed forces, airplane weapon industry) carries on the technological transformations. Except that uses outside the numerical control engine bed, FMC, FMS in the m anufacture process, but also includes in the product developm ent carries out CAD, CAE, CAM, the hypothesized manufactureas well as carries out MIS in the production management (ma nagement information system), CIMS and so on. As well as in creases the information technology in its production product, including artificial intelligence and so on content. Because uses the information technology to the country foreign troops, the airplane weapon industry carries on the thorough transfor mation (to call it becoming an information based society), f inally causes them the product in the international military goods and in the goods for civilian use market the competit ive power greatly is the enhancement. But we in the informa tion technology transformation tradition industry aspect compar ed to the developed country to fall behind approximately for 20 years. Like in our country engine bed capacity, numerical control engine bed proportion (numerical control rate) to 199 5 only then 1.9%, but Japan has reached 20.8% in 1994, therefore every year has the massive mechanical and electrical products import. This also on from on macroscopic explained the engine bed numerical control transformation necessity. Tho rd, the numerical control transformation content and superiorl y lacks3.1 Transformation industry startingIn US, Japan and Germany and so on the developed countr y, their engine bed transforms took the new economical growt h profession, thrives abundantly, is occupying the golden age .As a result of the engine bed as well as the technical u nceasing progress, the engine bed transformation is "the eter nal" topic. Our country's engine bed transformation industry, also enters from the old profession to by the numerical c ontrol technology primarily new profession. In US, Japan, Ger many, have the broad market with the numerical control techn ological transformations engine bed and the production line, has formed the engine bed and the production line numerical control transformation new profession. In US, the engine be d transformation industry is called the engine bed regenerati on(Remanufacturing) industry. Is engaged in the regeneration ind ustry famous company to include: The Bertsche engineering fir m, the ayton engine bed company, Devlieg-Bullavd (are valuabl e) serves the group, the US equipment company and so on. T he American valuable company has set up the company in Chin a. In Japan, the engine bed transformation industry is calle d the engine bed to reequip (Retrofitting) industry. Is enga ged in the reequipment industry famous company to include: B ig indentation project group, hillock three mechanical companies, thousand substitute fields labor machine company, wild engineering firm, shore field engineering firm, mountain this engineering firm and so on. 3.2 Numerical control transformat ion contentThe engine bed and the production line numerical control transformation main content has following several points: First is extensively recovers the function, to the engine bed, the production line has the breakdown partially to carr y on the diagnosis and the restoration;Second is NC, the addend reveals the installment on the ordinary engine bed, or adds the numerical control system, transforms the NC engine bed, the CNC engine bed;Third is renovates, for increases the precision, the effi ciency and the automaticity, to the machinery, the electricit y partially carries on renovates, reassembles the processing to the machine part, extensively recovers the precision; Does not satisfy the production request to it the CNC system to carry on the renewal by newest CNC;Fourth is the technology renews or the technical innovati on, for enhances the performance or the scale, or in order to use the new craft, the new technology, carries on the b ig scale in the original foundation the technology to renew or the technical innovation, the great scope raises the leve l and the scale renewal transformation. The new electri cal system transforms after, how carries on the debugging as well as the determination reasonable approval standard, also is the technology preparatory work important link. The debugg ing work involves the machinery, the hydraulic pressure, the electricity, the control, and so on, therefore must carry onby the project person in charge, other personnel coordinate. The debugging step may conform to simplicity to numerous, fr om infancy to maturity, carries on from outside to in, afte r also may the partial overall situation, after first the s ubsystem the 3.3 The numerical control transformation superior ly lacks 3.3.1 reduced investment costs, the date of deliv ery are short With purchases the new engine bed to comp are, may save 60% ~ 80% expense generally, the transformatio n expense is low. Large-scale, the special engine bed especi ally is specially obvious. The common large-scale engine bed transforms, only spends the new engine bed purchase expense 1/3, the date of delivery is short. But some peculiar circu mstances, like the high speed main axle, the tray automatic switching unit manufacture and the installment too requires a lot of work, costs a great deal of money, often transforms the cost to enhance 2 ~ 3 times, with purchases the new engine bed to compare, only can economical invest about 50 %.3.3.2 machine capability stable are reliable, the structure i s limitedUses foundation and so on lathe bed, column all is heav y but the firm casting component, but is not that kind of welding component, after the transformation engine bed perform ance high, the quality is good, may take the new equipment continues to use many years. But receives the original mecha nism the limit, not suitably makes the unprecedented transfor mation. 3.3.3 familiar understood the equipment, is advantag eous for the operation serviceWhen purchases the new equipment, did not understand whether the new equipment can satisfy its processing request. Th e transformation then otherwise, may precisely calculate the engine bed the processing ability; Moreover, because many yea rs use, the operator already understood to the engine bed c haracteristic, uses and services the aspect to train the tim e in the operation short, effective is quick. The transforma tion engine bed as soon as installs, may realize the capaci ty load revolution. 3.3.4 may fully use the existing condi tionMay fully use the existing ground, does not need to lik e buys when the new equipment such to have reto construct the ground. 3.3.5 may use the newest control technology enhances the production equipment the automated level and the efficiency, improves the equipment quality and the scale, alters to the old engine bed now the horizontal engine bed. Fourth, numerical control system choiceWhen the numerical control system mainly has three kind of types, the transformation, should act according to the sp ecial details to carry on the choice.4.1 Step-by-steps the open system which the electrical ma chinery drivesThis system servo drive mainly is step-by-steps the elect rical machinery, the power step-by-steps the electrical machin ery, the battery solution pulse motor and so on. Entering s ends out which by the numerical control system for instructi on pulse, after the actuation electric circuit control and t he power enlargement, causes to step-by-step the electrical m achinery rotation, through gear vice- and ball bearing guide screw vice- actuation executive component. So long as the control command pulse quantity, the frequency as well as the circular telegram order, then may control the executive compo nent movement the displacement quantity, the speed and the h eading. This kind of system does not need the physical loca tion and the velocity feedback which obtains to the input e nd, therefore called it the open system, this system displac ement precision mainly decided in step-by-steps the electrical machinery angular displacement precision, transmission part and so on gear guide screw pitches the precision, therefore the system displacement precision is low.This system structure simple, debugging service convenient, work reliable, cost low, is easy to reequip successfully.4.2 The asynchronous motor or the direct current machine drive, diffraction grating survey feedback closed loop numer ical control system .This system and the open system difference is: Physical location feedback signal which by position detector set and so on the diffraction grating, induction synchromesh obtains, carries on the comparison as necessary with the given value, two interpolations enlargements and the transformation, the ac tuation implementing agency, by the speed which assigns turns towards the elimination deviation the direction movement, unti l assigns the position and the feedback physical location in terpolation is equal to the zero. The closed loop enters fo r the systemEnters for the system complex in the structure compared to the split-ring, the cost is also high, requests strictly to the environment room temperature. The design and the debu gging is all more difficult than the open system. But mayobtain compared to the split-ring enters for a system higher precision, quicker speed, actuation power bigger characteristic target. May act according to the product specification, decid ed whether uses this kind of system.4.3 The direct current servo electrical machinery drives, encoder feedback semi-closure link numerical control system .Half closed-loop system examination part installs in among passes in the moving parts, indirectly surveys the executive component the position. It only can compensate a system ring circuit interior part of part the error, therefore, its prec ision compared to closed-loop system precision low, but its structure and the debugging all compares the closed-loop syst em to be simple. In makes the angular displacement examinati on part and the speed examination part and the servo electr ical machinery time a whole then does not need to consider the position detector set installs the question.The current production numerical control system company fa ctory quite are many, overseas famous company like German SI EMENS Corporation,Japanese FANUC Corporation; Native corporation like China Mount Everest Corporation, Beijing astronautics eng ine bed numerical control system group company, Central China numerical control company and Shenyang upscale numerical contr ol country engineering research center.When choice numerical control system mainly is each kind of precision which the engine bed must achieve after the nu merical control transformation, actuates the electrical machine ry the power and user's request.Fifth in the numerical control transformation the mainmechanical part reequips the discussionA new numerical control engine bed, must achieve in the design that, Has the high static dynamic rigidity; Movement vice- between friction coefficient small, the transmission is ceaseless; The power is big; Is advantageous for the operati on and the service. When engine bed numerical control transf ormation should meet the above requirements as far as possib le. Cannot think the numerical control installment and the o rdinary engine bed connects in has met the numerical control engine bed requirements together, but also should carry on t he corresponding transformation to the major component to ena ble it to achieve the certain design request, can obtain th e anticipated transformation goal. 5.1 skids guide railSaid to the numerical control lathe that, the guide rail besides should have the conventional lathe guidance precision and the technology capability, but also must have good bears the friction, the attrition characteristic, and the reduction but sends the dead area because of the friction drag. At t he same time must have the enough rigidity, by reduces the guide rail to distort to processes the precision the influen ce, must have the reasonable guide rail protection and the lubrication.5.2 gearThe common engine bed gear mainly concentrates in the headstock and the gear box.In order to guarantee the transmission precision, on the numerical control engine bed uses the gear precision class i s all higher than the ordinary engine bed. Must be able to achieve the ceaseless transmissionin the structure, thus transforms time, the engine bed maingear must satisfy the numerical control engine bed the reque st, by guarantees the engine bed processing precision.5.3 skids the guide screw and the ball bearing guide screwThe guide screw transmission relates directly to the tran smission chain precision. The guide screw selects mainly is decided requests and drives the torque request in the job p recision. Is not used by job precision request Gao Shike skids the guide screw, but should inspect the original guide screw attrition situation, like the pitch error and the pitc h accumulative error as well as matches the nut gap. The o rdinary circumstances skid the guide screw to be supposed no t to be lower than 6 levels, the nut gap oversized then r eplaces the nut. Uses skids the guide screw relative ball b earing guide screw price to be low, but satisfies the pre cision high components processing with difficulty.The ball bearing guide screw rubs loses slightly, the ef ficiency is high, its transmission efficiency may above 90%; Precision high, the life is long; When start moment of forc e and movement the moment of force approaches, may reduce t he electrical machinery to start the moment of force. Theref ore may satisfiedly compare the high accuracy components proc essing request. 5.4 safe protectionThe effect must take the security as a premise. Transfor ms in the engine bed must take the corresponding measure ac cording to the actual situation, cuts noticeable. The ball b earing guide screw vice- is the precision part, when the wo rk must take strict precautions against the dust is speciall y the scrap and the hard sand grains enters the roller conveyer. On longitudinal guide screw also coca overall sheet i ron safety mask. The big carriage with skids two end surfac es which the guide rail contacts to have to seal, prevented absolutely the flinty granulated foreign matter enters the sl iding surface damage guide rail.Sixth, After the engine bed electrical system transformati on, to operates, the programmers inevitably brings the new r equest. Therefore ahead of time carries on new system knowle dge training to the operator and the programmers to be extr emely important, after otherwise will affect the transformatio n the engine bed rapid investment production. The training c ontent should include the new operation kneading board dispos ition, the function, the instruction meaning generally; New s ystem functional scope, application method and with old syste m difference; Maintenance maintenance request; Programming stan dard and automated programming and so on. The key point is makes, gets a good grasp of the operating manual and the p rogramming instruction booklet.the numerical control transforms se Transforms the scope according to each equipment differently, must beforehand desig n the connection partial transformations, if transforms comple tely, should design the electro-mechanical transformation conne ction, the operation kneading board control and the dispositi on, the interconnection partial contacts, the parameter measur ing point, services the position and so on, the request ope rates and services conveniently, reasonable, the line moves t owards, center the small junction smoothly few, the strong a nd the weak electrical noise is smallest, has the suitable allowance and so on. Partial transformation, but also needsto consider the new old system the performance match, the v oltage polarity and the size transformation, install the posi tion, the digital-analog conversion and so on, when the nece ssity must manufacture the transformation connection voluntaril y.veral examples1st, transforms the X53 milling machine with SIEMENS 810MIn 1998, the company invested 200,000 Yuan, with German Simens the 810M numerical control system, the 611A exchange servo drive system sds was the X53 milling machine carries on X, Y, the Z three axle numerical control transformation to a company's model; Retained the original main axle system and the cooling system; The transformation three axle has us ed the roller lead screw and the gear drive organization on the machinery. The entire transformation work including the m achine design, the electrical design, the PLC procedure estab lishment and the debugging, the engine bed overhaul, finally is the entire machine installment and the debugging. After t he milling machine transforms, processing effective stroke X/Y /The Z axis respectively is 88.0/270/28 billion mm; Maximum speed X/Y/The Z axis respectively is 5000/1500/800 mm/Min; Ma nual speed X/Y/The Z axis respectively is 3000/1000/500 mm/Mi n; The engine bed processing precision achieves ±0.001mm. The engine bed three coordinates linkage may complete each kind of complex curve or the curved surface processi ng.2nd, transforms the C6140 lathe with GSK980T and the exc hange servo drive system sds .In 2000, with Guangzhou numerical control plant production GSK980T numerical control system, the DA98 exchange servo uni t and 4 locations automatic tool rests to an electrical mac hinery branch factory C6140 lathe X, the Z two axes carries on the numerical control transformation; Retained the original main axle system and the cooling system; The transformation two axes have used the roller lead screw and with the ambu lacrum transmission system on the machinery. Entire transforma tion work including machine design, electrical design, engine bed overhaul and entire machine installment and debugging. Af ter the lathe transforms, processing effective stroke X/The Z axis respectively is 3.90/73 million mm; Maximum speed X/The Z axis respectively is 120.0/3 million mm/Min; The manual sp eed is 400mm/Min; Manual is fast is X/The Z axis respective ly is 120.0/3 million mm/Min; The engine bed smallest migrat ion unit is 0.001mm.3rd, transforms the X53 milling machine with SIEMENS 802SIn 2000, the company invests 120,000 Yuan, with German S imens the 802S numerical control system, step-by-steps the ac tuation system is the X53 milling machine carries on X, Y, the Z three axle numerical control transformation to company' s another model; Retained the original main axle system and the cooling system; The transformation three axle has used t he roller lead screw and the gear drive organization on the machinery. The entire transformation work including the machin e design, the electrical design, the engine bed overhaul, fi nally is the entire machine installment and the debugging. A fter the milling machine transforms, processing effective stro。

数控铣床毕业设计外文翻译 2

7.1 INTRODUCTIONAfter lathes, milling machines are the most widely used for manufacturing applications. In milling, the workpiece is fed into a rotating milling cutter, which is a multi-point tool as shown in Fig. 7.1, unlike a lathe, which uses a single point cutting tool. The tool used in milling is called the milling cutter.Fig. 7.1Schematic diagram of a milling operationThe milling process is characterised by:(i)Interrupted cutting Each of the cutting edges removes materialfor only a part of the rotation of the milling cutter. As a result, the cutting edge has time to cool before it again removes material.Thus the milling operation is much more cooler compared to the turning operation. This allows for a much larger material rates.(ii)Small size of chips Though the size of the chips is small, in view of the multiple cutting edges in contact a large amount of material is removed and as a result the component is generally completed ina single pass unlike the turning process which requires a largenumber of cuts for finishing.(iii)Variation in chip thickness This contributes to the non-steady state cyclic conditions of varying cutting forces during the contact of the cutting edge with the chip thickness varying from zero to maximum size or vice versa. This cyclic variation of the force can excite any of the natural frequencies of the machine tool system and is harmful to the tool life and surface finish generatedA milling machine is one of the most versatile machine tools. It is adaptable for quantity production as well as in job shops and tool rooms. The versatility of milling is because of the large variety of accessories and tools available with milling machines. The typical tolerance expected from the process is about ±0.050 mm.7.2 TYPES OF MILLING MACHINESTo satisfy various requirements milling machines come in a number of sizes and varieties. In view of the large material removal ratesmilling machines come with a very rigid spindle and large power. The varieties of milling machines available are:(i) Knee and Column type(a) horizontal(b) vertical(c) universal(d) turret typeThese are the general purpose milling machines, which have a high degree of flexibility and are employed for all types of works including batch manufacturing. A large variety of attachments to improve the flexibility are available for this class of milling machines.(ii) Production (Bed) type(a) simplex(b) duplex(c) triplexThese machines are generally meant for regular production involving large batch sizes. The flexibility is relatively less in these machines which is suitable for productivity enhancement.(iii) Plano millersThese machines are used only for very large workpieces involving table travels in meters.(iv) Special type(a) Rotary table(b) Drum type(c) Copy milling (Die sinking machines)(d) Key way milling machines(e) Spline shaft milling machinesThese machines provide special facilities to suit specific applications that are not catered to by the other classes of milling machines.7.2.1 Knee and Column Milling MachinesThe knee(升降台) and column type is the most commonly used machine in view of its flexibility and easier setup. A typical machine construction is shown in Fig. 7.2 for the horizontal axis. The knee houses the feed mechanism and mounts the saddle and table. The table basically has the T-slots running along the X-axis for the purpose of work holding. The table moves along the X-axis on the saddle while the saddle moves along the Y-axis on the guide ways provided on the knee.The feed is provided either manually with a hand wheel or connected for automatic by the lead screw, which in turn is coupled to the main spindle drive. The knee can move up and down (Z-axis) on a dovetail provided on the column.Fig. 7.2 Horizontal knee and column type milling machineThe massive column at the back of the machine houses all the power train including the motor and the spindle gearbox. The power for feeding the table lead screw is taken from the main motor through a separate feed gearbox. Sometimes a separate feed motor is provided for the feed gearbox as well.While the longitudinal and traverse motions are provided with automatic motion, the raising of the knee is generally made manually.The spindle is located at the top end of the column. The arbour used to mount the milling cutters is mounted in the spindle and is provided with a support on the other end to take care of the heavy cutting forces by means of an overarm with bearing. As shown in Fig.7.2 the overarm extends from the column with a rigid design. The spindle nose has the standard Morse taper of the suitable sizedepending upon the machine size.The milling cutters are mounted on the arbour at any desired position, the rest of the length being filled by standard hardened collars of varying widths to fix the position of the cutter. The arbour is clamped in the spindle with the help of a draw bar and then fixed with nuts.Milling machines are generally specified on the following basis:(i) Size of the table, which specifies the actual working area on the table and relates to the maximum size of the workpiece that can be accommodated.(ii) Amount of table travel, which gives the maximum axis movement that is possible.(iii) Horse power of the spindle, which actually specifies the power of the spindle motor used. Smaller machines may come with 1 to 3 hp while the production machines may go from 10 to 50 hp.Another type of knee and column milling machine is the vertical axis type. Its construction is very similar to the horizontal axis type, except for the spindle type and location.The vertical axis milling machine is relatively more flexible (Fig. 7.4) and suitable for machining complex cavities such as die cavities in tool rooms. The vertical head is provided with a swiveling facility in horizontal direction whereby the cutter axis can be swivelled. This isuseful for tool rooms where more complex milling operations are carried out.The spindle is located in the vertical direction and is suitable for using the shank mounted milling cutters such as end mills, In view of the location of the tool, the setting up of the workpiece and observing the machining operation is more convenient.Fig, 7.3 Vertical knee and column type milling machineFig.7.4 Some of the milling operations normally carried out on vertical axis machinesThe universal machine has the table which can be swivelled in a horizontal plane at about 45o to either the left or right. This makes the universal machine suitable for milling spur and helical gears as well as worm gears and cams.7.2.2 Bed Type Milling MachineIn production milling machines it is desirable to increase the metal removal rates. If it is done on conventional machines by increasingthe depth of cut, there is possibility of chatter. Hence another varietyof milling machines named as bed type machines are used which are made more rugged and are capable of removing more material. The ruggedness is obtained as a consequence of the reduction in versatility.The table in the case of bed type machines is directly mounted on the bed and is provided with only longitudinal motion.The spindle moves along with the column to provide the cutting action. Simplex machines (Fig. 7.5) are the ones with only one spindle head while duplex machines have two spindles (Fig. 7.6). The two spindles are located on either side of a heavy workpiece and remove material from both sides simultaneously.Fig. 7.5 Simplex bed type milling machineFig. 7.6 Duplex bed type milling machine7.3 MILLING CUTTERSThere are a large variety of milling cutters available to suit specific requirements. The versatility of the milling machine is contributed toa great extent by the variety of milling cutters that are available.7.3.1 Types of Milling CuttersMilling cutters are classified into various types based on a variety of methods.(i) Based on construction:(a) Solid(b) Inserted tooth typeBased on mounting:(a) Arbor mounted(b) Shank mounted(c) Nose mountedBase on rotation:(a) Right hand rotation (counter clockwise)(b) Left hand rotation (clockwise)Based on helix:(a) Right hand helix(b) Left hand helixMilling cutters are generally made of high speed steel or cemented carbides. The cemented carbide cutters can be of a brazed tip variety or with indexable tips. The indexable variety is more common since it is normally less expensive to replace the worn out cutting edges than to regrind them.Plain milling cutters These are also called slab milling cutters and are basically cylindrical with the cutting teeth on the periphery as shown in Fig. 7.7. These are generally used for machining flat surfaces.Fig. 7.7 Arbor mounted milling cutters for general purposeLight duty slab milling cutters generally have a face width, which is small of the order of 25 mm. They generally have straight teeth and large number of teeth.Heavy duty slab milling cutters come with a smaller number of teeth to allow for more chip space. This allows taking deeper cuts and consequently high material removal rates.Helical milling cutters have a very small number of teeth but a large helix angle. This type of cutter cuts with a shearing action, which can produce a very fine finish. The large helix angle allows the cutter to absorb most of the end load and therefore the cutter enters and leaves the workpiece very smoothly.Side and face milling cutters These have the cutting edges not only onthe face like the slab milling cutters, but also on both the sides. As aresult, these cutters become more versatile since they can be used for side milling as well as for slot milling.Staggered tooth side milling cutters are a variation where the teeth are arranged in an alternate helix pattern. This type is generally used for milling deep slots, since the staggering of teeth provides for greater chip space.Another variation of the side and face cutter is the half side milling cutter, which has cutting edges only on one side. This arrangement provides a positive rake angle and is useful for machining on only one side. These have a much smoother cutting action and a long tool life. The power consumed is also less for these cutters.Fig. 7.8Special forms of arbor mounted milling cuttersSlitting saws The other common form of milling cutters in the arbor mounted category is the slitting saw. This is very similar to a saw blade inappearance as well as function. Most of these have teeth around the circumference while some have side teeth as well. The thickness of these cutters is generally very small and is used for cutting off operations or for deep slots.Special form cutters In addition to the general type of milling cutters described above, there are a large number of special form milling cutters available which are used for machining specific profiles.Angular milling cutters are made in single or double angle cutters for milling any angle such as 30, 45 or 60o Form relieved cutters are made of various shapes such as circular, corner rounding, convex or concave shapes.T-slot milling cutters are used for milling T-slots such as those in the milling machine table. The central slot is to be milled first using an end mill before using the T-slot milling cutter. Woodruff key seat milling cutters are used for milling as the name suggests, woodruff key seats Some other special form cutters are dovetail milling cutters and gear milling cutters.End mills These are shank mounted as shown in Fig. 7.9 and are generally used in vertical axis milling machines. They are used for milling slots, key ways and pockets where other type of milling cutters cannot be used. A depth of cut of almost half the diameter can be taken with the end mills.The end mills have the cutting edge running through the length of the cutting portion as well as on the face radially up to a certain length. The helix angle of the cutting edge promotes smooth and efficient cutting even at high cutting speeds and feed rates. High cutting speeds(转速?) are generally recommended for this type of milling cutters.Fig. 7.9 Shank mounted milling cutters and various types of end mills There are a large variety of end mills. One of the distinctions is based on the method of holding, i.e., the end mill shank can be straight or tapered. The straight shank is used on end mills of small size and held in the milling machine spindle with the help of a suitable collet. The tapered shank can be directly mounted in the spindle with the help of the selfholding taper. If the taper is small compared to the spindle taper, then an adopter accommodating both the tapers is used.The end teeth of the end mills may be terminated at a distance from the cutter center or may proceed till the center (Fig. 7.9 f). Those with the cutting edge up to the center are called slot drills or end cutting end mills since they have the ability to cut into the solid material (Fig. 7.9 g). The other type of end mills which have a larger number of teeth cannot cut into solid material and hence require a pilot hole drilled before a pocket is machined.The cutting edge along the side of an end mill is generally straight and sometimes can be tapered by grinding on a tool and cutter grinder such that the draft required for mould and die cavities can be automatically generated.第七章铣削7.1介绍除了车床，铣床是制造应用中最广泛使用的。

数控技术外文文献翻译

数控技术外文文献翻译(含：英文原文及中文译文)英文原文The development trend of numerical control technology AbstractThe current trends in the development of numerical control technology and equipment in the world and the status quo of the development and industrialization of CNC equipment technology in China are briefly introduced. On this basis, we discuss the development of CNC technology and equipment in China under the new environment of China's accession to the WTO and further opening to the outside world. The importance of improving the level of China's manufacturing informatization and international competitiveness, and put forward some views on the development of China's CNC technology and equipment from both strategic and strategic aspects.The technological level and degree of modernization of the equipment industry determine the level of the entire national economy and the degree of modernization. Numerical control technology and equipment are the development of emerging high-tech industries and cutting-edge industries (such as information technology and its industries, biotechnology and its industries, aviation, aerospace, etc.) (Defense Industry Industry) enabling technology and basic equipment. Marx oncesaid that “the difference between various economic times is no t what is produced but how it is produced and what labor data it is used to produce”. Manufacturing technology and equipment are the most basic production materials for human production activities, and numerical control technology is the core technology of today's advanced manufacturing technologies and equipment. In the manufacturing industry of the world today, CNC technology is widely used to improve manufacturing capabilities and levels, and to improve the adaptability and competitiveness of dynamic markets. In addition, various industrialized countries in the world have also listed numerical control technology and numerical control equipment as strategic materials of the country. They not only take significant measures to develop their own numerical control technologies and their industries, but also have the key technology and equipment of “high-precision” numerical control. Our country adopts a policy of blockade and restriction. In short, the vigorous development of advanced manufacturing technologies centered on numerical control technology has become an important way for all developed countries in the world to accelerate economic development and improve their overall national strength and national status.Numerical control technology is a technology that uses digital information to control mechanical movement and work process. Numerical control equipment is a mechatronic product formed by thepenetration of new technologies represented by numerical control technology into traditional manufacturing industries and emerging manufacturing industries, namely, so-called digital equipment. Its technical scope covers many fields: (1) machinery manufacturing technology; (2) information processing, processing, and transmission technology; (3) automatic control technology; (4) servo drive technology;(5) sensor technology; (6) software Technology and so on. Keywords: CNC technology, machinery manufacturing, information processing, sensors1 Development Trends of Numerical Control TechnologyThe application of numerical control technology has not only brought about revolutionary changes in the traditional manufacturing industry, but also made manufacturing a symbol of industrialization. With the continuous development of numerical control technology and the expansion of application fields, he has made important contributions to the national economy and people's livelihood (IT, automotive The development of light industry, light industry, medical care, etc. is playing an increasingly important role, because the digitalization of the equipment required by these industries is a major trend of modern development. From the current trend of numerical control technology and its equipment development in the world, its main research hotspots are the following aspects [1~4].1.1 New trends in high-speed, high-precision processing technology and equipmentEfficiency and quality are the mainstays of advanced manufacturing technology. High-speed, high-precision machining technology can greatly improve efficiency, improve product quality and grade, shorten production cycle and increase market competitiveness. To this end, the Japanese Advanced Technology Research Institute will list it as one of the five major modern manufacturing technologies. The International Association of Production Engineers (CIRP) has identified it as one of the central research directions for the 21st century.In the passenger car industry, the production cycle of 300,000 vehicles per year is 40 seconds per vehicle, and multi-species processing is one of the key issues that must be addressed for car equipment. In the aviation and aerospace industries, the parts processed by them are mostly thin-walled. With thin ribs, the rigidity is poor, and the material is aluminum or aluminum alloy. These ribs and walls can be processed only when the high cutting speed and cutting force are small. Recently, the method of “hollowing out” large-size aluminum alloy billets has been used to manufacture large parts such as wings and fuselage to replace multiple parts and assembled by numerous rivets, screws, and other coupling methods to obtain strength, stiffness, and reliability of components. improve. All of these require high-speed, high-precision andhigh-flexibility for processing equipment.From the standpoint of EMO2001, the feed rate of high-speed machining centers can reach 80m/min, or even higher, and the airspeed can reach around 100m/min. At present, many automobile plants in the world, including China's Shanghai General Motors Corporation, have adopted a part of the production line consisting of a high-speed machining center to replace the combined machine tools. The HyperMach machine tool feed rate of CINCINNATI, USA is up to 60m/min, the speed is 100m/min, the acceleration is 2g, and the spindle speed has reached 60,000r/min. It takes only 30 minutes to machine a thin-walled aircraft part, and the same part takes 3h for general high-speed milling and 8h for normal milling; the spindle speed and acceleration of the twin-spindle lathe of DMG, Germany, reach 12*!000r/mm respectively. And 1g.In terms of machining accuracy, in the past 10 years, the machining accuracy of ordinary CNC machine tools has increased from 10μm to 5μm, precision machining centers have increased from 3~5μm to 1~1.5μm, and ultra-precision machining precision has begun to enter the nanometer level. (0.01μm).In terms of reliability, the MTBF value of foreign numerical control devices has reached more than 6000 hours, and the MTBF value of the servo system has reached more than 30,000 hours, showing very highreliability.In order to achieve high-speed, high-precision machining, the supporting functional components such as electric spindles and linear motors have been rapidly developed and the application fields have been further expanded.1.2 Rapid development of 5-axis simultaneous machining and compound machiningThe use of 5-axis simultaneous machining of 3D surface parts allows cutting with the best geometry of the tool, resulting in not only a high degree of finish, but also a significant increase in efficiency. It is generally considered that the efficiency of a 5-axis machine tool can be equal to 2 3-axis linkage machines. Especially when using ultra-hard material milling tools such as cubic boron nitride for high-speed milling of hardened steel parts, 5-axis simultaneous machining can be compared with 3-axis linkage. Processing to play a higher efficiency. In the past, due to the complexity of the 5-axis linkage CNC system and the host machine structure, the price was several times higher than that of the 3-axis linkage CNC machine tool, and the programming technology was more difficult, which restricted the development of 5-axis linkage machine tools.At present, due to the emergence of electric spindles, the structure of the composite spindle head that realizes 5-axis simultaneous machining isgreatly simplified, its manufacturing difficulty and cost are greatly reduced, and the price gap of the numerical control system is reduced. As a result, the development of composite spindle head type 5-axis linkage machine tools and compound machine tools (including 5-sided machine tools) has been promoted.At the EMO2001 exhibition, the new 5-axis machine tool of Nippon Machine Tool Co., Ltd. adopts a compound spindle head, which can realize the processing of four vertical planes and processing at any angle, so that 5-sided machining and 5-axis machining can be realized on the same machine tool. It can realize the processing of inclined surface and inverted cone. Germany DMG company exhibited DMUV oution series machining center, which can be processed in five-face machining and five-axis linkage in a single clamping. It can be directly or indirectly controlled by CNC system control or CAD/CAM.1.3 Intelligentization, openness, and networking have become major trends in the development of modern digital control systemsThe 21st century CNC equipment will be a certain intelligent system. The intelligent content is included in all aspects of the CNC system: in order to pursue the processing efficiency and processing quality in the intelligent, such as the process of adaptive control, process parameters automatically Generated; To improve the driving performance and the use of convenient connection intelligent, such as feed-forward control,adaptive calculation of motor parameters, automatic identification load automatic selection model, self-tuning, etc.; simplify the programming, simplify the operation of intelligent, such as smart The automatic programming, intelligent man-machine interface, etc.; as well as the contents of intelligent diagnosis, intelligent monitoring, convenient system diagnosis and maintenance.In order to solve the problems of traditional CNC system closure and industrial application of CNC application software. At present, many countries have conducted research on open numerical control systems such as NGC of the United States, OSACA of the European Community, OSEC of Japan, and ONC of China. The openness of numerical control systems has become the future of CNC systems. The so-called open CNC system is the development of CNC system can be in a unified operating platform, for machine tool manufacturers and end users, by changing, adding or cutting structure objects (CNC function), to form a series, and can be convenient to the user's special The application and technology are integrated into the control system to quickly realize open numerical control systems of different varieties and different grades to form brand-name products with distinctive personality. At present, the architecture specification, communication specification, configuration specification, operation platform, numerical control system function library and numerical control system function software development toolof open CNC system are the core of current research.Networked CNC equipment is a new bright spot in the international well-known machine tool exposition in the past two years. The networking of CNC equipment will greatly satisfy the requirements of information integration for production lines, manufacturing systems, and manufacturing companies. It is also the basic unit for realizing new manufacturing models such as agile manufacturing, virtual enterprise, and global manufacturing. Some famous domestic and foreign CNC machine tools and numerical control system manufacturing companies have introduced relevant new concepts and prototypes in the past two years. For example, at the EMO 2001 exhibition, the “Cyber Production Center” exhibited by Japan's Mazak company Mazak Production Control Center (CPC); Okuma Machine Too l Company, Japan exhibited “ITplaza” (Information Technology Plaza, IT Plaza); Open Manufacturing Environment (Open Manufacturing Environment, OME), exhibited by Siemens, Germany Etc., reflecting the trend of the development of CNC machine tools to the direction of the network.1.4 Emphasizing the Establishment of New Technology Standards and Specifications1.4.1 About Design and Development of CNC SystemsAs mentioned above, the open CNC system has better versatility, flexibility, adaptability, and expandability. The United States, theEuropean Community, and Japan have implemented strategic development plans one after another, and have conducted the open architecture system specification (OMAC). , OSACA, OSEC) research and development, the world's three largest economies in the short term carried out almost the same set of scientific plans and norms, indicating that the arrival of a new revolution in digital technology. In 2000, China began to conduct research and development of the regulatory framework for China's ONC numerical control system.1.4.2 About CNC StandardsCNC standards are a trend in the development of manufacturing informatization. The information exchange in the 50 years since the birth of CNC technology was based on the ISO 6983 standard. That is how the G and M codes describe how to process. The essential feature is the processing-oriented process. Obviously, he has been unable to meet the high speed of modern CNC technology. The need for development. For this purpose, a new CNC system standard ISO14649 (STEP-NC) is being researched and developed internationally. Its purpose is to provide a uniform data model that can describe the entire life cycle of a product without relying on a neutral mechanism of a specific system. , in order to achieve the entire manufacturing process, and even the standardization of product information in various industrial fields. The emergence of STEP-NC may be a revolution in CNC technology. It will have aprofound impact on the development of CNC technology and even the entire manufacturing industry. First, STEP-NC proposes a brand-new manufacturing concept. In the traditional manufacturing concept, NC machining programs are concentrated on a single computer. Under the new standard, NC programs can be distributed on the Internet. This is the direction of open and networked CNC technology. Secondly, STEP-NC CNC system can also greatly reduce the processing drawings (about 75%), processing program preparation time (about 35%) and processing time (about 50%).At present, European and American countries attach great importance to the research of STEP-NC, and Europe has initiated STEP-NC's IMS plan ( Participation in this program comes from 20 CAD/CAM/CAPP/CNC users, vendors and academic institutions in Europe and Japan. STEPTools of the United States is the developer of global manufacturing data exchange software. He has developed a SuperModel for the information exchange of CNC machine tools. Its goal is to describe all machining processes with a unified specification. This new data exchange format has now been validated on prototype prototypes equipped with SIEMENS, FIDIA and European OSACA-NC numerical control systems.2 Basic Estimates of China's CNC Technology and Its Industrial DevelopmentCNC technology in China started in 1958. The development process in the past 50 years can be roughly divided into three stages: the first stage from 1958 to 1979, which is the closed development stage. At this stage, the development of numerical control technology is relatively slow due to the limitations of foreign technology and China's basic conditions. The second stage is the introduction of technology during the “sixth and fifth” periods of the country, the “seventh five-year plan” period, and the “eighth five-year plan period,”and it will be digested and absorbed to initially establish the stage of the national production system. At this stage, due to the reform and opening up and the country’s attention, as well as the improvement of the research and development environment an d the international environment, China’s CNC technology has made great progress in research, development, and localization of products. The third stage is the implementation of industrialization research in the later period of the "Eighth Five-Year Plan" and the "Ninth Five-Year Plan" period of the country, entering the stage of market competition. At this stage, the industrialization of domestically-manufactured CNC equipment has achieved its essenceSexual progress. At the end of the “Ninth Five-Year Plan” period, the domestic market share of domestic CNC machine tools reached 50%, and the number of domestically-manufactured numerical control systems (pervasive models) also reached 10%.Looking at the development process of CNC technology in China in the past 50 years, especially after four five-year plans, the overall results are as follows:a. It lays the foundation for the development of CNC technology and basically masters modern CNC technology. China has now basically mastered the basic technologies from numerical control systems, servo drives, numerical control mainframes, special planes and their accessories. Most of these technologies already have the basis for commercial development. Some technologies have been commercialized and industrialized.b. Initially formed a CNC industrial base. Based on the research results and the commercialization of some technologies, we have established numerical control system production plants such as Huazhong Numerical Control and Aerospace Numerical Control which have mass production capabilities. Lanzhou Electric Machinery Factory, Huazhong Numerical Control and a number of servo systems and servo motor manufacturers, as well as a number of CNC machine manufacturers such as Beijing No. 1 Machine Tool Plant and Jinan No. 1 Machine Tool Plant. These production plants have basically formed China's CNC industrial base.c. Established a basic team of CNC research, development and management talents.Although significant progress has been made in the research, development, and industrialization of numerical control technology, we must also soberly realize that the research and development of high-end numerical control technologies in China, especially the status quo of the technological level of industrialization and the actual needs of China There is a big gap. Although our country's development speed is very fast in the vertical direction, the horizontal ratio (compared with foreign countries) not only has a gap in the level of technology, but also has a gap in the development speed in certain aspects, that is, the gap in the technological level of some highly sophisticated numerical control equipment has expanded. From the international point of view, the estimated level of China's numerical control technology and industrialization is roughly as follows:a. On the technical level, it will be about 10 to 15 years behind the advanced level in foreign countries, and it will be even bigger in terms of sophisticated technology.b. At the industrialization level, the market share is low, the variety coverage is small, and scale production has not yet been established; the specialized production level of functional components and the complete set capacity are low; the appearance quality is relatively poor; the reliability is not high, and the degree of commercialization is insufficient; The domestic CNC system has not established its own brand effect, andthe user's confidence is insufficient.c. On the ability of sustainable development, the research and development and engineering capabilities of pre-competitive numerical control technology are weak; the application of numerical control technology is not strong; the research and formulation of related standard specifications is lagging behind.The main reasons for analyzing the above gaps are as follows:a. Awareness. Insufficient understanding of the arduous, complex and long-term characteristics of the domestic CNC industry process; Insufficient estimates of market irregularities, foreign blockades, killings, and systems; and insufficient analysis of the application level and capabilities of CNC technology in China.b. Systematic aspects. From the point of view of technology, attention has been paid to the issue of CNC industrialization. It has been a time to consider the issue of CNC industrialization from the perspectives of system and industry chain; there is no complete supporting system of high-quality supporting systems, perfect training, and service networks. .c. Mechanisms. Bad mechanisms have led to brain drain, which in turn has restricted technological and technological route innovations and product innovations, and has constrained the effective implementation of planning. It is often planned to be ideal and difficult to implement.d. Technical aspects. Enterprises have little ability to independentlyinnovate in technology, and the engineering ability of core technologies is not strong. The standard of machine tools is backward, the level is low, and the new standard of CNC system is not enough.3 Strategic Thinking on the Development of CNC Technology and Industrialization in China3.1 Strategic ConsiderationsChina is a manufacturing country, and we must try to accept the transfer of the front-end rather than the back-end in the industrial transfer of the world. That is to master the advanced manufacturing core technologies, otherwise, in the new round of international industrial restructuring, China's manufacturing industry will further “empty core”. At the expense of resources, the environment, and the market, we may obtain only the international "processing centers" and "assembly centers" in the world's new economic structure, rather than the status of manufacturing centers that master core technologies. This will seriously affect our country. The development of modern manufacturing.We should pay attention to numerical control technology and industrial issues from the perspective of national security strategy. First of all, we must look at social security because manufacturing industry is the industry with the largest number of employed people in China. Manufacturing industry development can not only improve the people’s living standards, but also ease the country’s The pressure of employmentguarantees social stability. Secondly, from the perspective of national defense security, Western developed countries classify high-precision numerical control products as national strategic materials and implement embargoes and restrictions on China. The “Toshiba Incident” and the “Cox Report” "This is the best illustration.3.2 Development StrategyFrom the perspective of China’s basic national conditions, taking the country’s strategic needs and the market demand of the national economy as the guide, and aiming at improving the comprehensive competitiveness and industrialization le vel of China’s manufacturing equipment industry, we can use systematic methods to choose to dominate the early 21st century in China. The key technologies for the development and upgrade of the manufacturing equipment industry and supporting technologies and supporting technologies for supporting industrialization development are the contents of research and development and the leap-forward development of the manufacturing equipment industry. Emphasizing the market demand as the orientation, that is, taking CNC terminal products as the mainstay, and driving the CNC industry with complete machines (such as large-scale CNC lathes, milling machines, high-speed, high-precision and high-performance CNC machine tools, typical digital machines, key equipment of key industries, etc.). development of. The focus is on the reliability and production scale of CNC systems andrelated functional components (digital servos and motors, high-speed spindle systems and accessories for new equipment, etc.). Without scale, there will be no high-reliability products; without scale, there will be no cheap and competitive products; of course, CNC equipment without scale in China will be difficult to come to the fore. In the research and development of high-precision equipment, we must emphasize the close integration of production, learning, research, and end-users, and aim at “doing, using, and selling off” as a goal, and implement national research on the will of the country to solve the urgent need of the country. . Before the competition, CNC technology emphasizes innovation, emphasizes research and development of technologies and products with independent intellectual property rights, and lays a foundation for the sustainable development of China's CNC industry, equipment manufacturing industry, and even the entire manufacturing industry.中文译文数控技术的发展趋势摘要本文简要介绍了当今世界数控技术及装备发展的趋势及我国数控装备技术发展和产业化的现状, 在此基础上讨论了在我国加入WTO 和对外开放进一步深化的新环境下, 发展我国数控技术及装备、提高我国制造业信息化水平和国际竞争能力的重要性, 并从战略和策略两个层面提出了发展我国数控技术及装备的几点看法。

数控加工外文翻译文献

数控加工外文翻译文献(文档含中英文对照即英文原文和中文翻译)原文:Basic Machining Operations and CuttingTechnologyBasic Machining OperationsMachine tools have evolved from the early foot-powered lathes of the Egyptians and John Wilkinson's boring mill. They are designed to provide rigid support for both the workpiece and the cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically, in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the form of a severely deformed chip. The chip is a waste product that is considerably shorter than the workpiece from which it came but with a corresponding increase in thickness of the uncut chip. The geometrical shape of workpiece depends on the shape of the tool and its path during the machining operation.Most machining operations produce parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and the tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is produced, and the operation is called turning. If a hollow tube is machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface uniformly varying diameter is called taper turning, if the tool point travels in a path of varying radius, a contoured surface like that of a bowling pin can be produced; or, if the piece is short enough and the support is sufficiently rigid, a contoured surface could be produced by feeding a shaped tool normal to the axis of rotation. Short tapered or cylindrical surfaces could also be contour formed.Flat or plane surfaces are frequently required. They can be generated by radial turning or facing, in which the tool point moves normal to the axis of rotation. In other cases, it is more convenient to hold the workpiece steady andreciprocate the tool across it in a series of straight-line cuts with a crosswise feed increment before each cutting stroke. This operation is called planning and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpiece under it as in planning. The tool is fed at each reciprocation. Contoured surfaces can be produced by using shaped tools.Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for holes with depths up to 5 to 10 times the drill diameter. Whether the drill turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary cutter with a number of cutting edges engages the workpiece. Which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter and the type of feed. Horizontal or vertical axes of rotation may be used, and the feed of the workpiece may be in any of the three coordinate directions.Basic Machine ToolsMachine tools are used to produce a part of a specified geometrical shape and precise I size by removing metal from a ductile material in the form of chips. The latter are a waste product and vary from long continuous ribbons of a ductile material such as steel, which are undesirable from a disposal point of view, to easily handled well-broken chips resulting from cast iron. Machine tools perform five basic metal-removal processes: I turning, planning, drilling, milling, and grinding. All other metal-removal processes are modifications of these five basic processes. For example, boring is internal turning; reaming, tapping, and counter boring modify drilled holes and are related to drilling; bobbing and gear cutting are fundamentally milling operations; hack sawing and broaching are a form of planning and honing; lapping, super finishing. Polishing and buffing are variants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cuttingtools of specific controllable geometry: 1. lathes, 2. planers, 3. drilling machines, and 4. milling machines. The grinding process forms chips, but the geometry of the abrasive grain is uncontrollable.The amount and rate of material removed by the various machining processes may be I large, as in heavy turning operations, or extremely small, as in lapping or super finishing operations where only the high spots of a surface are removed.A machine tool performs three major functions: 1. it rigidly supports the workpiece or its holder and the cutting tool; 2. it provides relative motion between the workpiece and the cutting tool; 3. it provides a range of feeds and speeds usually ranging from 4 to 32 choices in each case.Speed and Feeds in MachiningSpeeds, feeds, and depth of cut are the three major variables for economical machining. Other variables are the work and tool materials, coolant and geometry of the cutting tool. The rate of metal removal and power required for machining depend upon these variables.The depth of cut, feed, and cutting speed are machine settings that must be established in any metal-cutting operation. They all affect the forces, the power, and the rate of metal removal. They can be defined by comparing them to the needle and record of a phonograph. The cutting speed (V) is represented by the velocity of- the record surface relative to the needle in the tone arm at any instant. Feed is represented by the advance of the needle radially inward per revolution, or is the difference in position between two adjacent grooves. The depth of cut is the penetration of the needle into the record or the depth of the grooves.Turning on Lathe CentersThe basic operations performed on an engine lathe are illustrated. Those operations performed on external surfaces with a single point cutting tool arecalled turning. Except for drilling, reaming, and lapping, the operations on internal surfaces are also performed by a single point cutting tool.All machining operations, including turning and boring, can be classified as roughing, finishing, or semi-finishing. The objective of a roughing operation is to remove the bulk of the material as rapidly and as efficiently as possible, while leaving a small amount of material on the work-piece for the finishing operation. Finishing operations are performed to obtain the final size, shape, and surface finish on the workpiece. Sometimes a semi-finishing operation will precede the finishing operation to leave a small predetermined and uniform amount of stock on the work-piece to be removed by the finishing operation.Generally, longer workpieces are turned while supported on one or two lathe centers. Cone shaped holes, called center holes, which fit the lathe centers are drilled in the ends of the workpiece-usually along the axis of the cylindrical part. The end of the workpiece adjacent to the tailstock is always supported by a tailstock center, while the end near the headstock may be supported by a headstock center or held in a chuck. The headstock end of the workpiece may be held in a four-jaw chuck, or in a type chuck. This method holds the workpiece firmly and transfers the power to the workpiece smoothly; the additional support to the workpiece provided by the chuck lessens the tendency for chatter to occur when cutting. Precise results can be obtained with this method if care is taken to hold the workpiece accurately in the chuck.Very precise results can be obtained by supporting the workpiece between two centers. A lathe dog is clamped to the workpiece; together they are driven by a driver plate mounted on the spindle nose. One end of the Workpiece is mecained;then the workpiece can be turned around in the lathe to machine the other end. The center holes in the workpiece serve as precise locating surfaces as well as bearing surfaces to carry the weight of the workpiece and to resist the cutting forces. After the workpiece has been removed from the lathe for any reason, the center holes will accurately alignthe workpiece back in the lathe or in another lathe, or in a cylindrical grinding machine. The workpiece must never be held at the headstock end by both a chuck and a lathe center. While at first thought this seems like a quick method of aligning the workpiece in the chuck, this must not be done because it is not possible to press evenly with the jaws against the workpiece while it is also supported by the center. The alignment provided by the center will not be maintained and the pressure of the jaws may damage the center hole, the lathe center, and perhaps even the lathe spindle. Compensating or floating jaw chucks used almost exclusively on high production work provide an exception to the statements made above. These chucks are really work drivers and cannot be used for the same purpose as ordinary three or four-jaw chucks.While very large diameter workpieces are sometimes mounted on two centers, they are preferably held at the headstock end by faceplate jaws to obtain the smooth power transmission; moreover, large lathe dogs that are adequate to transmit the power not generally available, although they can be made as a special. Faceplate jaws are like chuck jaws except that they are mounted on a faceplate, which has less overhang from the spindle bearings than a large chuck would have.Introduction of MachiningMachining as a shape-producing method is the most universally used and the most important of all manufacturing processes. Machining is a shape-producing process in which a power-driven device causes material to be removed in chip form. Most machining is done with equipment that supports both the work piece and cutting tool although in some cases portable equipment is used with unsupported workpiece.Low setup cost for small Quantities. Machining has two applications in manufacturing. For casting, forging, and press working, each specific shape to be produced, even one part, nearly always has a high tooling cost. The shapes that may he produced by welding depend to a large degree on the shapes ofraw material that are available. By making use of generally high cost equipment but without special tooling, it is possible, by machining; to start with nearly any form of raw material, so tong as the exterior dimensions are great enough, and produce any desired shape from any material. Therefore .machining is usually the preferred method for producing one or a few parts, even when the design of the part would logically lead to casting, forging or press working if a high quantity were to be produced.Close accuracies, good finishes. The second application for machining is based on the high accuracies and surface finishes possible. Many of the parts machined in low quantities would be produced with lower but acceptable tolerances if produced in high quantities by some other process. On the other hand, many parts are given their general shapes by some high quantity deformation process and machined only on selected surfaces where high accuracies are needed. Internal threads, for example, are seldom produced by any means other than machining and small holes in press worked parts may be machined following the press working operations.Primary Cutting ParametersThe basic tool-work relationship in cutting is adequately described by means of four factors: tool geometry, cutting speed, feed, and depth of cut.The cutting tool must be made of an appropriate material; it must be strong, tough, hard, and wear resistant. The tool s geometry characterized by planes and angles, must be correct for each cutting operation. Cutting speed is the rate at which the work surface passes by the cutting edge. It may be expressed in feet per minute.For efficient machining the cutting speed must be of a magnitude appropriate to the particular work-tool combination. In general, the harder the work material, the slower the speed.Feed is the rate at which the cutting tool advances into the workpiece. "Where the workpiece or the tool rotates, feed is measured in inches perrevolution. When the tool or the work reciprocates, feed is measured in inches per stroke, Generally, feed varies inversely with cutting speed for otherwise similar conditions.The depth of cut, measured inches is the distance the tool is set into the work. It is the width of the chip in turning or the thickness of the chip in a rectilinear cut. In roughing operations, the depth of cut can be larger than for finishing operations.The Effect of Changes in Cutting Parameters on Cutting TemperaturesIn metal cutting operations heat is generated in the primary and secondary deformation zones and these results in a complex temperature distribution throughout the tool, workpiece and chip. A typical set of isotherms is shown in figure where it can be seen that, as could be expected, there is a very large temperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and there is a further large temperature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip.Since virtually all the work done in metal cutting is converted into heat, it could be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and the cutting temperatures will reduce. When considering increase in unreformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness tends to be a scale effect where the amounts of heat which pass to the workpiece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed; however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip m primary deformation. Further, the secondarydeformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate it is appropriate to indicate how cutting temperatures can be assessed from cutting data.The most direct and accurate method for measuring temperatures in high -speed-steel cutting tools is that of Wright &. Trent which also yields detailed information on temperature distributions in high-speed-steel cutting tools. The technique is based on the metallographic examination of sectioned high-speed-steel tools which relates microstructure changes to thermal history.Trent has described measurements of cutting temperatures and temperature distributions for high-speed-steel tools when machining a wide range of workpiece materials. This technique has been further developed by using scanning electron microscopy to study fine-scale microstructure changes arising from over tempering of the tempered martens tic matrix of various high-speed-steels. This technique has also been used to study temperature distributions in both high-speed -steel single point turning tools and twist drills.Wears of Cutting ToolDiscounting brittle fracture and edge chipping, which have already been dealt with, tool wear is basically of three types. Flank wear, crater wear, and notch wear. Flank wear occurs on both the major and the minor cutting edges. On the major cutting edge, which is responsible for bulk metal removal, these results in increased cutting forces and higher temperatures which if left unchecked can lead to vibration of the tool and workpiece and a condition where efficient cutting can no longer take place. On the minor cutting edge, which determines workpiece size and surface finish, flank wear can result in anoversized product which has poor surface finish. Under most practical cutting conditions, the tool will fail due to major flank wear before the minor flank wear is sufficiently large to result in the manufacture of an unacceptable component.Because of the stress distribution on the tool face, the frictional stress in the region of sliding contact between the chip and the face is at a maximum at the start of the sliding contact region and is zero at the end. Thus abrasive wear takes place in this region with more wear taking place adjacent to the seizure region than adjacent to the point at which the chip loses contact with the face. This result in localized pitting of the tool face some distance up the face which is usually referred to as catering and which normally has a section in the form of a circular arc. In many respects and for practical cutting conditions, crater wear is a less severe form of wear than flank wear and consequently flank wear is a more common tool failure criterion. However, since various authors have shown that the temperature on the face increases more rapidly with increasing cutting speed than the temperature on the flank, and since the rate of wear of any type is significantly affected by changes in temperature, crater wear usually occurs at high cutting speeds.At the end of the major flank wear land where the tool is in contact with the uncut workpiece surface it is common for the flank wear to be more pronounced than along the rest of the wear land. This is because of localised effects such as a hardened layer on the uncut surface caused by work hardening introduced by a previous cut, an oxide scale, and localised high temperatures resulting from the edge effect. This localised wear is usually referred to as notch wear and occasionally is very severe. Although the presence of the notch will not significantly affect the cutting properties of the tool, the notch is often relatively deep and if cutting were to continue there would be a good chance that the tool would fracture.If any form of progressive wear allowed to continue, dramatically and the tool would fail catastrophically, i. e. the tool would be no longer capable ofcutting and, at best, the workpiece would be scrapped whilst, at worst, damage could be caused to the machine tool. For carbide cutting tools and for all types of wear, the tool is said to have reached the end of its useful life long before the onset of catastrophic failure. For high-speed-steel cutting tools, however, where the wear tends to be non-uniform it has been found that the most meaningful and reproducible results can be obtained when the wear is allowed to continue to the onset of catastrophic failure even though, of course, in practice a cutting time far less than that to failure would be used. The onset of catastrophic failure is characterized by one of several phenomena, the most common being a sudden increase in cutting force, the presence of burnished rings on the workpiece, and a significant increase in the noise level. Mechanism of Surface Finish ProductionThere are basically five mechanisms which contribute to the production of a surface which have been machined. These are:(l) The basic geometry of the cutting process. In, for example, single point turning the tool will advance a constant distance axially per revolution of the workpiecc and the resultant surface will have on it, when viewed perpendicularly to the direction of tool feed motion, a series of cusps which will have a basic form which replicates the shape of the tool in cut.(2) The efficiency of the cutting operation. It has already been mentioned that cutting with unstable built-up-edges will produce a surface which contains hard built-up-edge fragments which will result in a degradation of the surface finish. It can also be demonstrated that cutting under adverse conditions such as apply when using large feeds small rake angles and low cutting speeds, besides producing conditions which lead to unstable built-up-edge production, the cutting process itself can become unstable and instead of continuous shear occurring in the shear zone, tearing takes place, discontinuous chips of uneven thickness are produced, and the resultant surface is poor. Thissituation is particularly noticeable when machining very ductile materials such as copper and aluminum.(3) The stability of the machine tool. Under some combinations of cutting conditions; workpiece size, method of clamping ,and cutting tool rigidity relative to the machine tool structure, instability can be set up in the tool which causes it to vibrate. Under some conditions this vibration will reach and maintain steady amplitude whilst under other conditions the vibration will built up and unless cutting is stopped considerable damage to both the cutting tool and workpiece may occur. This phenomenon is known as chatter and in axial turning is characterized by long pitch helical bands on the workpiece surface and short pitch undulations on the transient machined surface.(4)The effectiveness of removing swarf. In discontinuous chip production machining, such as milling or turning of brittle materials, it is expected that the chip (swarf) will leave the cutting zone either under gravity or with the assistance of a jet of cutting fluid and that they will not influence the cut surface in any way. However, when continuous chip production is evident, unless steps are taken to control the swarf it is likely that it will impinge on the cut surface and mark it. Inevitably, this marking besides looking.(5)The effective clearance angle on the cutting tool. For certain geometries of minor cutting edge relief and clearance angles it is possible to cut on the major cutting edge and burnish on the minor cutting edge. This can produce a good surface finish but, of course, it is strictly a combination of metal cutting and metal forming and is not to be recommended as a practical cutting method. However, due to cutting tool wear, these conditions occasionally arise and lead to a marked change in the surface characteristics.Limits and TolerancesMachine parts are manufactured so they are interchangeable. In other words, each part of a machine or mechanism is made to a certain size and shape so will fit into any other machine or mechanism of the same type. Tomake the part interchangeable, each individual part must be made to a size that will fit the mating part in the correct way. It is not only impossible, but also impractical to make many parts to an exact size. This is because machines are not perfect, and the tools become worn. A slight variation from the exact size is always allowed. The amount of this variation depends on the kind of part being manufactured. For examples part might be made 6 in. long with a variation allowed of 0.003 (three-thousandths) in. above and below this size. Therefore, the part could be 5.997 to 6.003 in. and still be the correct size. These are known as the limits. The difference between upper and lower limits is called the tolerance.A tolerance is the total permissible variation in the size of a part.The basic size is that size from which limits of size arc derived by the application of allowances and tolerances.Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance.Unilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is shown in only one direction from the nominal size. Unilateral tolerancing allow the changing of tolerance on a hole or shaft without seriously affecting the fit.When the tolerance is in both directions from the basic size it is known as a bilateral tolerance (plus and minus).Bilateral tolerancing is a system of dimensioning where the tolerance (that is variation) is split and is shown on either side of the nominal size. Limit dimensioning is a system of dimensioning where only the maximum and minimum dimensions arc shown. Thus, the tolerance is the difference between these two dimensions.Surface Finishing and Dimensional ControlProducts that have been completed to their proper shape and size frequently require some type of surface finishing to enable them tosatisfactorily fulfill their function. In some cases, it is necessary to improve the physical properties of the surface material for resistance to penetration or abrasion. In many manufacturing processes, the product surface is left with dirt .chips, grease, or other harmful material upon it. Assemblies that are made of different materials, or from the same materials processed in different manners, may require some special surface treatment to provide uniformity of appearance.Surface finishing may sometimes become an intermediate step processing. For instance, cleaning and polishing are usually essential before any kind of plating process. Some of the cleaning procedures are also used for improving surface smoothness on mating parts and for removing burrs and sharp corners, which might be harmful in later use. Another important need for surface finishing is for corrosion protection in a variety of: environments. The type of protection procedure will depend largely upon the anticipated exposure, with due consideration to the material being protected and the economic factors involved.Satisfying the above objectives necessitates the use of main surface-finishing methods that involve chemical change of the surface mechanical work affecting surface properties, cleaning by a variety of methods, and the application of protective coatings, organic and metallic.In the early days of engineering, the mating of parts was achieved by machining one part as nearly as possible to the required size, machining the mating part nearly to size, and then completing its machining, continually offering the other part to it, until the desired relationship was obtained. If it was inconvenient to offer one part to the other part during machining, the final work was done at the bench by a fitter, who scraped the mating parts until the desired fit was obtained, the fitter therefore being a 'fitter' in the literal sense. J It is obvious that the two parts would have to remain together, and m the event of one having to be replaced, the fitting would have to be done all over again. Inthese days, we expect to be able to purchase a replacement for a broken part, and for it to function correctly without the need for scraping and other fitting operations.When one part can be used 'off the shelf' to replace another of the same dimension and material specification, the parts are said to be interchangeable.A system of interchangeability usually lowers the production costs as there is no need for an expensive, 'fiddling' operation, and it benefits the customer in the event of the need to replace worn parts.Automatic Fixture DesignTraditional synchronous grippers for assembly equipment move parts to the gripper centre-line, assuring that the parts will be in a known position after they arc picked from a conveyor or nest. However, in some applications, forcing the part to the centre-line may damage cither the part or equipment. When the part is delicate and a small collision can result in scrap, when its location is fixed by a machine spindle or mould, or when tolerances are tight, it is preferable to make a gripper comply with the position of the part, rather than the other way around. For these tasks, Zaytran Inc. Of Elyria, Ohio, has created the GPN series of non- synchronous, compliant grippers. Because the force and synchronizations systems of the grippers are independent, the synchronization system can be replaced by a precision slide system without affecting gripper force. Gripper sizes range from 51b gripping force and 0.2 in. stroke to 40Glb gripping force and 6in stroke. GrippersProduction is characterized by batch-size becoming smaller and smaller and greater variety of products. Assembly, being the last production step, is particularly vulnerable to changes in schedules, batch-sizes, and product design. This situation is forcing many companies to put more effort into extensive rationalization and automation of assembly that was previouslyextensive rationalization and automation of assembly that was previously the case. Although the development of flexible fixtures fell。

X62W铣床数控化改造外文文献翻译、中英文翻译、外文翻译

X62W铣床数控化改造外文文献翻译、中英文翻译、外文翻译X62W CNC milling machine transformation1 general CNC transformation of the need for analysisOur about 3200000 existing machine tools, the machine tool technol ogy status of ageing is serious, according to statistics, about 30% of the total country equipment in more than 16 years, of which nearly 30% of age more than 26 years, all these show the present our country did no t go mainly rely on progress of science and technology of machine tools to transform track. In addition, with the development of science and tec hnology, production is dependent on the degree of equipment increases i ncreasingly, the crop of the enterprise, quality, efficiency, cost, safety an d environmental protection and labor emotions get equipment restrict, rea lize the modernization of enterprise oneself be imperative. But according to the data, our metal cutting machine tool production only accounted for similar equipment to have an amount 1 / 28, such as the annual produ ction of all the machines used to replace the old machine tool needs 28 years so, our country is solved at present equipment technical progress is the main way of machine tools.2 domestic and foreign research present situationIn today's world, industrial developed country to machine tool industr y height seriously, competing for the development of mechanical and ele ctrical integration, high precision, high efficiency, high automation and ad vanced machine tool, in order to accelerate the industrial and economic development. For a long time, Europe and the United States, Asia in the international market are in fierce competition, has formed an invisible fr ont, especially with microelectronics, computer technology, numericalcont rol machine tools in the nineteen eighties later accelerated development, put forward more requirements of all users, had become the four big int ernational machine tool exhibition to display machine tool manufacturers advanced technology, for the user, enlarge the market focus. The more f amous control system : Japan FANUC series, Mitsubishi series, OKUNIA series, SODICK series, series of Hitachi, Germany SIEMENS series, DE CKEL series, Heidenhain series, HELLER series, the United States ALLE N-BRADLEY ( AB ) series, CINCINNANTI series, Num series, FIDIA seri es of France, Italy, Spain, Switzerland FAGOR series, AG series of dom estic series.In the United States, Japan and Germany and other developed coun tries, they will machine transformation as a new economic growth sector, the business scene, is in the golden age. As the machine tool and the continuous advancement of technology, machine tools transformation is a "timeless" issue. Transformation of China's machine tool industry, but a lso from the old to the industry into the digital technology-based new ind ustries. In the United States, Japan, Germany, with machine tool of num erical control technical reformation and production line has a broad mark et, has formed a production line of CNC machine tool and the new indu stry. In the United States, reconstruction of machine tool industry called machine regeneration ( Remanufacturing ) industry. Engaged in renewabl e industry's well-known companies: Bertsche engineering company, ayton machine tool company, Devlieg-Bullavd ( PO ) services group, US equi pment company. The United States company has been in China for the company. Rebuilding of machine tool industry in Japan called machine m odified ( Retrofitting ) industry. Engaged in refitting industry well-knownc ompanies have: Doomsday engineering group, three post machinery com pany, Chiyoda engineering machine company, Nozaki engineering compa ny, Hamada engineering company, Yamamoto engineering company.Catch up with the pace of computer system structure, accelerate the development of NC system for NC development speed, has become the main trend. The fourth generation computer engineering structure and m icroelectronic technology as the basis, make full use of existing computer hardware, software resources, development of bus type, module type, o pen type, embedded on a flexible NC system, which is suitable for mach ining complex parts, vertical machine tool with CNC system, but also for future automation upgrades the function may be expanded requirements.China 's NC system development has the following 3 features: ( 1 ) system of high-grade numerical control technology has been a breakthrough. As of I type numerical control system, with multi axis linka ge function, fast feed speed in 1.67m / s above, have stronger communi cation, management function.( 2) universal CNC system is a mature technology. Beijing Machine Tool Research Institute BS9l system, these systems are generally equipp ed with CRT display, can be configured to DC and AC servo drive, 2 ~ 4 shaft linkage.( 3) the economic type CNC system still has vast market prospect. As a result of this kind of system has the advantages of simple structur e, cheap price, very suitable for small and medium enterprises in China,is still the most widely applied in CNC system. A typical Nanjing gener ous JWK series.Our country is big country of production of machine tools, itis the u se of power. NC machine tool is the key to the development of machine ry industry products, China's CNC machine tool in machine tool products in the proportion of the overall low level of. But our country is a develo ping country, a lot of enterprises financial weakness, not likely to spend a lot of money on a lot of new CNC machine tools, while a large numb er of universal machine tool can not be all eliminated.Therefore, the transformation of general machine tools CNC machine is a effective way to improve the rate of NC machine tools transformati on, less cost, reform targeted, time is short, after the transformation of t he machine tool are able to overcome the original machine faults and pr oblems, high production efficiency.3 basic scheme comparison and selectionNC transformation of the main general plan shall include the followin g contents: the servo drive system, numerical control device selection, el ectrical equipment, mechanical design, CNC hardware system. Show cent to narrate as follows.The 3.1 servo drive systemServo system is a important part of NC machine tool, its performanc e will directly affect the machining accuracy, surface quality and producti on efficiency, it can be divided into 3 kinds, namely, open loop, closed l oop, loop.3.1.1 open loop systemOpen loop system is the most simple servo, stepper motor as the o pen loop system main device, it has the advantages of simple structure ( electrical control and drive circuit is simple ), small volume, light weight, low price, convenient repair and maintenance characteristics3.1.2 closed loop systemClosed loop system, its structure is complex, technical difficulty is gr eat, testing and repair more difficult, cost is high. Closed loop control ca n achieve good accuracy of machine tools, to compensate for mechanica l transmission system in a variety of error, eliminate the gap, interferenc e on the accuracy of processing, generally applied to the high requireme nts of NC equipment.3.1.3 semi closed loop systemSemi closed loop system with closed-loop system similar to, the posi tion detection device is mounted on the execution component, but mount ed on the drive motor end or the end of the drive rod, indirectly measur ed actuator position or displacement. Due to its wide range of speed ( 0.1 - 3OOO R / rain ), strong overload capacity, and the feedback control, the precision can reach 0.01 ~ 0.001nlln, as fast as 0.5 m / s, so its p erformance is far superior to the stepping motor open loop control, and t he feedback link does not include most of mechanical transmission comp onents, simple debugging ratio closed loop, the system stability can be e asily ensured, than the closed loop is easy to realize. Therefore, usinga closed-loop system, is more reliable and feasible.3.1.4 AC, DC servo motor comparisonClosed loop, half closed loop system can be AC or DC servo motor, the AC speed regulation gradually expanding the scope of application, s eems to have replaced DC servo trend. But AC servo control of complic ated structure, high technical difficulty, popularity is not wide, and the pri ce is high ( DC servo motor 1.5 ~ 20000 yuan / Taiwan, AC servo mot or is 2 - 30000 ) in addition, compared to the DC servo motor AC serv o motor with large inertia, the small inertia, debugging difficulty big, whe n thesources are more difficult to repair components. DC servo motor p rinciple similar to DC motor, control system technology is more mature, spread wide, its main drawback is the large volume, large weight, but als o with the commutator and brush, increased repair workload.Through the comparison, the success rate, technical difficulty, precisi on and investment and other factors, decided to adopt DC servo loop co ntrol.3.2 numerical control deviceNumerical control device also has a variety of scheme selection. For example, can all of its own design, production; can use SBCs or STD module control; can use readily available numerical control device for a small number of applicable changes or matching. In the factory's practica l application, generally use the following 2 kinds of solution. A kind of cir cumstance is required for the function and requirement of ready-made C NC device can meet, then used mostly to buy ready-made products solu tion, because of own design is not only a waste of time, investment is n ot necessarily can save investment, more often, and quality do not nece ssarily guarantee. Another kind of circumstance is not to buy off-the-shelf products to achieve some special function, then mostly adopt buy price performance ratio as high performance close to the device, and then to supplement or transformation, at least also bought STD template or indu strial control computer, single board computer to make.According to the selected DC servo drive and processing requiremen ts, the numerical control device can realize closed loop ( loop ) of contr ol, provides the analog control signal,receives the half closed loop feed back signal to control; three coordinate axis of motion, wherein at least t o simultaneously control linkage to complete the arc differential complem ent; in the processing of can use different size cutter, CNC device with cutting tool radius and length compensation in NC machining, so accordi ng to the contour programming and can adapt to the size of tool change, in order to meet the needs of future development and clear structure, d ecided to adopt the STD template, modular design.3.3 other electrical devicesIn numerical control transformation, also needs to be combined with the numerical control device and servo drive configuration characterized by other electrical parts, including the strong and weak electrical signal c onversion, transmission or processing necessary. The input / lucky bird o ut interface to consider whether isolation, shielding requirements; in additi on, but also configure the needed power, all kinds of protection circuit, a uxiliary circuit detecting display.3.4 mechanical partsIn the equipment of numerical control transformation, although is the core part of CNC, involve more is microelectronics and electrical, but n ot of all. If you ignore the mechanical aspects according to the character istics of CNC machine tools for the corresponding necessary changes, or in the transformation of the design and manufacture of endless and rea sonable, the results will give numerical control transformation brings beat all difficulties, and may even lead to failure because of mechanical prob lems.3.5 CNC numerical control systemThe CNC system is composed of CPU memory template;servo mot or interface circuit board; the keyboard, display interface circuit board an d a switch quantity input, output interface circuit board. Each template m ain function is as follows.3.5.1CPU memory boardThe board carried out various data operations, timer in the interventi on, timing execution system program, coordination, management of vario us parts of the circuit to work.In addition, also has a power down protection, power on reset and generates a pulse signal and other functions. At the same time, board m emory, for storing system software, computing the results of staging and storage parts processing program. Plate communicationInterface for the boards and peripherals to provide a convenient com munication.3.5.2 servo motor interface circuit boardThe plate is connected to the servo motor and the CPU bridge. CP U issued a servo motor control instruction code, through the template D / A conversion, operational amplifier after being sent to the motor drive s ource, thus realizing the electrical automatic control. At the same time th e motor running state, through the detecting device of the pulse, in the plate after processing, in the form of code into CPU, CPU adjust motor control instruction, thereby forming displacement closed loop system. If th e pulse signal by F / V conversion, can get the speed control unit feedb ack voltage, which constitute a closed loop system.X62W铣床数控化改造1.普通机床数控化改造的必要性分析我国现有机床320多万台，这些机床技术状况老化严重，据统计，全国30%左右设备在16年以上，其中近30%的役龄超过了26年，这些都说明目前我国还没有走上主要依靠科技进步对机床进行改造的轨道。

（数控加工）机械类数控外文翻译外文文献英文文献数控

（数控加工）机械类数控外文翻译外文文献英文文献数控NumericalControlOneofthemostfundamentalconceptsintheareaofadvancedmanufacturingte chnologiesisnumericalcontrol(NC).PriortotheadventofNC,allmachinetools weremanualoperatedandcontrolled.Amongthemanylimitationsassociatedwith manualcontrolmachinetools,perhapsnoneismoreprominentthanthelimitation ofoperatorskills.Withmanualcontrol,thequalityoftheproductisdirectlyre latedtoandlimitedtotheskillsoftheoperator.Numericalcontrolrepresentst hefirstmajorstepawayfromhumancontrolofmachinetools.Numericalcontrolmeansthecontrolofmachinetoolsandothermanufacturin gsystemsthoughtheuseofprerecorded,writtensymbolicinstructions.Rathert hanoperatingamachinetool,anNCtechnicianwritesaprogramthatissuesoperat ionalinstructionstothemachinetool,Foramachinetooltobenumericallycontr olled,itmustbeinterfacedwithadeviceforacceptinganddecodingthep2ogramm edinstructions,knownasareader.Numericalcontrolwasdevelopedtoovercomethelimitationofhumanoperato r,andithasdoneso.Numericalcontrolmachinesaremoreaccuratethanmanuallyo peratedmachines,theycanproducepartsmoreuniformly,theyarefaster,andthe long-runtoolingcostsarelower.ThedevelopmentofNCledtothedevelopmentofs everalotherinnovationsinmanufacturingtechnology:1.Electricaldischargemachining.sercutting.3.Electronbeamwelding.Numericalcontrolhasalsomademachinetoolsmoreversatilethantheirmanuallyoperatedpredecessors.AnNCmachinetoolcanautomaticallyproduceawidev arietyofpar4s,eachinvolvinganassortmentofundertaketheproductionofprod uctsthatwouldnothavebeenfeasiblefromaneconomicperspectiveusingmanuall ycontrolledmachinetoolsandprocesses.Likesomanyadvancedtechnologies,NCwasborninthelaboratoriesoftheMas sachusettsInstituteofTechnology.TheconceptofNCwasdevelopedintheearly1 950swithfundingprovidedbytheU.SAirForce.Initsearlieststages,NCmachine swereabletomakestraightcutsefficientlyandeffectively.However,curvedpathswereaproblembecausethemachinetoolhadtobeprogra mmedtoundertakeaseriesofhorizontalandverticalstepstoproduceacurve.The shorteristhestraightlinesmakingupthestep,thesmootheris4hecurve.Eachli nesegmentinthestepshadtobecalculated.Thisproblemledtothedevelopmentin1959oftheAutomaticallyProgrammedT ools(APT)languageforNCthatusesstatementssimilartoEnglishlanguagetodef inethepartgeometry,describethecuttingtoolconfiguration,andspecifythen ecessarymotions.ThedevelopmentoftheAPTlanguagewasamajorstepforwardint hefurtherdevelopmentofNCtechnology.TheoriginalNCsystemwerevastlydiffe rentfromthoseusedpunchedpaper,whichwaslatertoreplacedbymagneticplasti ctape.Atapereaderwasusedtointerprettheinstructionswrittenonthetapefor themachine.Together,all/fthisrepresentedgiantstepforwardinthecontrolo fmachinetools.However,therewereanumberofproblemswithNCatthispointinit sdevelopment.Amajorproblemwasthefragilityofthepunchedpapertapemedium.Itwascomm onforthepapercontainingtheprogrammedinstructionstobreakortearduringam achiningprocess,Thisproblemwasexacerbatedbythefactthateachsuccessivet imeapartwasproducedonamachinetool,thepapertapecarryingtheprogrammedin structionshadtorerunthoughtthereader.Ifitwasnecessarytoproduce100copi esofagivenpart,itwasalsonecessarytorunthepapertapethoughtthereader100 separatetimes.Fragilepapertapessimplycouldnotwithstandtherigorsofshop floorenvironmentandthiskindofrepeateduse.Thisledtothedevelopmentofaspecialmagnetictape.Whereasthepapertape carriedtheprogrammedinstructionsasaseriesofholespunchedinthetape,theT hismostimportantofthesewasthatitwasdifficultorimpossibletochangethein structionsenteredonthetape.Tomakeeventhemostminoradjustmentsinaprogra mofinstructions,itwasnecessarytointerruptmachiningoperationsandmakean ewtape.Itwasalsostillnecessarytorunthetapethoughtthereaderasmanytimes astherewerepartstobeproduced.Fortunately,computertechnologybecomearea lityandsoonsolvedtheproblemsofNC,associatedwithpunchedpaperandplastic tape.Thedevelopmentofaconceptknownasnumericalcontrol(DNC)solvethepaper andplastictapeproblemsassociatedwithnumericalcontrolbysimplyeliminati ngtapeasthemediumforcarryingtheprogrammedinstructions.Indirectnumeric alcontrol,machinetoolsaretied,viaadatatransmissionlink,toahostcompute randfedtothemachinetoolasneededviathedatatransmissionlinkage.Directnumericalcontrolrepresentedamajorstepforwardoverpunchedtapeandplasticta pe.However,itissubjecttothesamelimitationasalltechnologiesthatdependo nahostcomputer.Whenthehostcomputergoesdown,themachinetoolsalsoexperie ncedowntime.Thisproblemledtothedevelopmentofcomputernumericalcontrol.Thedevelopmentofthemicroprocessorallowedforthedevelopmentofprogra mmablelogiccontrollers(PLC)andmicrocomputers.Thesetwotechnologiesallo wedforthedevelopmentofcomputernumericalcontrol(CNC).WithCNC,eachmachi netoolhasaPLCoramicrocomputerthatservesthesamepurpose.Thisallowsprogr Csolvedtheproblems associateddowntimeofthehostcomputer,butitintroducedanotherproblemknow nasdatamanagement.Thesameprogrammightbeloadedontendifferentmicrocompu terswithnocommunicationamongthem.Thisproblemisintheprocessofbeingsolv edbylocalareanetworksthatconnectDigitalSignalProcessorsTherearenumeroussituationswhereanalogsignalstobeprocessedinmanywa ys,likefilteringandspectralanalysis,Designinganaloghardwaretoperformt hesefunctionsispossiblebuthasbecomelessandpractical,duetoincreasedper formancerequirements,flexibilityneeds,andtheneedtocutdownondevelopmen t/testingtime.Itisinotherwordsdifficultpmdesignanaloghardwareanalysis ofsignals.Theactofsamplingansignalintothehatarespecialisedforembeddedsignal processingoperations,andsuchaprocessoriscalledaDSP,whichstandsforDigi talSignalProcessor.TodaytherearehundredsofDSPfamiliesfromasmanymanufacturers,eachonedesignedforaparticularprice/performance/usagegroup.Man yofthelargestmanufacturers,likeTexasInstrumentsandMotorola,offerboths pecialisedDSP’sforcertainfieldslikemotor-controlormodems,andgeneralh igh-performanceDSP’sthatcanperformbroadrangesofprocessingtasks.Devel opmentkitsan`softwarearealsoavailable,andtherearecompaniesmakingsoftw aredevelopmenttoolsforDSP’sthatallowstheprogrammertoimplementcomplex processingalgorithmsusingsimple“drag‘n’drop”methodologies.DSP’smoreorlessfallintotwocategoriesdependingontheunderlyingarch itecture-fixed-pointandfloating-point.Thefixed-pointdevicesgenerallyo perateon16-bitwords,whilethefloating-pointdevicesoperateon32-40bitsfl oating-pointwords.Needlesstosay,thefixed-pointdevicesaregenerallychea per.Anotherimportantarchitecturaldifferenceisthatfixed-pointprocessor stendtohaveanaccumulatorarchitecture,withonlyone“generalpurpose”reg ister,makingthemquitetrickytoprogramandmoreimportantly,makingC-compil ersinherentlyinefficient.Floating-pointDSP’sbehavemorelikecommongene ral-purposeCPU’s,withregister-files.TherearethousandsofdifferentDSP’sonthemarket,anditisdifficulttas kfindingthemostsuitableDSPforaproject.Thebestwayisprobablytosetupacon straintandwishlist,andtrytocomparetheprocessorsfromthebiggestmanufact urersagainstit.The“bigfour”manufacturersofDSPs:TexasInstruments,Motorola,AT&Ta ndAnalogDevices.Digital-to-analogconversionInthecaseofMPEG-Audiodecoding,digitalcompresseddataisfedintotheDS Pwhichperformsthedecoding,thenthedecodedsampleshavetobeconvertedbacki ntotheanalogdomain,andtheresultingsignalfedanamplifierorsimilaraudioe quipment.Thisdigitaltoanalogconversion(DCA)isperformedbyacircuitwitht hesamename&DifferentDCA’sprovidedifferentperformanceandquality,asmea suredbyTHD(Totalharmonicdistortion),numberofbits,linearity,speed,filt ercharacteristicsandotherthings.TheTMS320familyDQPofTexasInstrumentsTheTLS320familyconsistsoffixed-point,floating-point,multiprocesso rdigitalsignalprocessors(D[Ps),andfoxed-pointDSPcontrollers.TMS320DSP haveanarchitecturedesignedspecificallyforreal-timesignalprocessing.Th e’F/C240isanumberofthe’C2000DSPplatform,andisoptimizedforcontrolapp lications.The’C24xseriesofDSPcontrollerscombinesthisreal-timeprocess ingcapabilitywithcontrollerperipheralstocreateanidealsolutionforcontr olsystemapplications.ThefollowingcharacteristicsmaketheTMS320familyth erightchoiceforawiderangeofprocessingapplications:---Veryflexibleinstructionset---Inherentoperationalflexibility---High-speedperformance---Innovativeparallelarchitecture---CosteffectivenessDeviceswithinagenerationoftheTMS320familyhavethesameCPUstructure butdifferenton-chipmemoryandperipheralconfigurations.Spin-offdevicesu senewcombinationsofOn-chipmemoryandperipheralstosatisfyawiderangeofne edsintheworldwideelectronicsmarket.Byintegratingmemoryandperipheralso ntoasinglechip,TMS320devicesreducesystemcostsandsavecircuitboardspace .The16-bit,fixed-pointDSPcoreofthe‘C24xdevicesprovidesanalogdesi gnersadigitalsolutionthatdoesnotsacrificetheprecisionandperformanceof theirsystemperformancecanbeenhancedthroughtheuseofadvancedcontrolalgo rithmsfortechniquessuchasadaptivecontrol,Kalmanfiltering,andstatecont rol.The‘C24xDSPcontrollerofferreliabilityandprogrammability.Analogco ntrolsystems,ontheotherhand,arehardwiredsolutionsandcanexperienceperf ormancedegradationduetoaging,componenttolerance,anddrift.Thehigh-speedcentralprocessingunit(CPU)allowsthedigitaldesignert oprocessalgorithmsinrealtimeratherthanapproximateresultswithlook-upta bles.TheinstructionsetoftheseDSPcontrollers,whichincorporatesbothsign alprocessinginstructionsandgeneral-purposecontrolfunctions,coupledwit htheextensivedevelopmenttimeandprovidesthesameeaseofuseastraditional8 -and16-bitmicrocontrollers.Theinstructionsetalsoallowsyoutoretainyour softwareinvestmentwhenmovingfromothergeneral-purpose‘C2xxgeneration, sourcecodecompatiblewiththe’C2xgeneration,andupwardlysourcecodecompa tiblewiththe‘C5xgenerationofDSPsfromTexasInstruments.The‘C24xarchitectureisalsowell-suitedforprocessingcontrolsignal s.Itusesa16-bitwordlengthalongwith32-bitregistersforstoringintermedia teresults,andhastwohardwareshiftersavailabletoscalenumbersindependent lyoftheCPU.Thiscombinationminimizesquantizationandtruncationerrors,an dincreasesp2ocessingpowerforadditionalfunctions.Suchfunctionsmightinc ludeanotchfilterthatcouldcancelmechanicalresonancesinasystemoranestim ationtechniquethatcouldeliminatestatesensorsinasystem.The‘C24xDSPcontrollerstakeadvantageofansetofperipheralfunctions thatallowTexasInstrumentstoquicklyconfigurevariousseriesmembersfordif ferentprice/performancepointsorforapplicationoptimization.Thislibraryofbothdigitalandmixed-signalperipheralsincludes:---Timers---Serialcommunicationsports(SCI,SPI)---Analog-to-digitalconverters(ADC)---Eventmanager---Systemprotection,suchaslow-voltageandwatchdogtimerTheDSPcontrollerperipherallibraryiscontinuallygrowingandchanging tosuittheoftomorrow’sembeddedcontrolmarketplace.TheTMS320F/C240isthefirststandarddeviceintroducedinthe‘24xserie sofDSPcontrollers.Itsetsthestandardforasingle-chipdigitalmotorcontrol ler.The‘240canexecute20MIPS.Almostallinstructionsareexecutedinasimpl ecycleof50ns.Thishighperformanceallowsreal-timeexecutionofverycomple8controlalgorithms,suchasadaptivecontrolandKalmanfilters.Veryhighsampl ingratescanalsobeusedtominimizeloopdelays.The‘240hasthearchitecturalfeaturesnecessaryforhigh-speedsignalp rocessinganddigitalcontrolfunctions,andithastheperipheralsneededtopro videasingle-chipsolutionformotorcontrolapplications.The‘240ismanufac turedusingsubmicronCMOStechnology,achievingalogpowerdissipationrating.A lsoincludedareseveralpower-downmodesforfurtherpowersavings.Someapplic ationsthatbenefitfromtheadvancedprocessingpowerofthe‘240include: ---Industrialmotordrives---Powerinvertersandcontrollers---Automotivesystems,suchaselectronicpowersteering,antilockbrake s,andclimatecontrol---ApplianceandHVACblower/compressormotorcontrols---Printers,copiers,andotherofficeproducts---Tapedrives,magneticopticaldrives,andothermassstorageproducts---RoboticandCNCmillingmachinesTofunctionasasystemmanager,aDSPmusthaverobuston-chipI/Oandotherp eripherals.Theeventmanagerofthe‘240isunlikeanyotheravailableonaDSP.T hisapplication-optimizedperipheralunit,coupledwiththehighperformanceD SPcore,enablestheuseofadvancedcontroltechniquesforhigh-precisionandhi gh-efficiencyfullvariable-speedcontrolofallmotortypes.Includeintheeve ntmanagerarespecialpulse-widthmodulation(PWM)generationfunctions,suchasaprogrammabledead-bandfunctionandaspacevectorPWMstatemachinefor3-ph asemotorsthatprovidesstate-of-the-artmaximumefficiencyintheswitchingo fpowertransistors.Thereindependentupdowntimers,eachwithit’sowncompareregister,sup portthegenerationofasymmetric(noncentered)aswellassymmetric(centered) PWMwaveforms.Open-LoopandClosed-LoopControlOpen-loopControlSystemsThewordautomaticimpliesthatthereisacertainamountofsophistication inthecontrolsystem.Byautomatic,itgenerallymeansThatthesystemisusually capableofadaptingtoavarietyofoperatingconditionsandisabletorespondtoa classofinputssatisfactorily.However,notanytypeofcontrolsystemhastheau ually,theautomaticfeatureisachievedbyfeed.gthefeedbackstructure,itiscalledanopen-loopsystem,whichisthesimp lestandmosteconomicaltypeofcontrolsystem.inaccuracyliesinthefactthato nemaynotknowtheexactcharacteristicsofthefurther,whichhasadefinitebear ingontheindoortemperature.Thisalcopointstoanimportantdisadvantageofth eperformanceofanopen-loopcontrolsystem,inthatthesystemisnotcapableofa daptingtovariationsinenvironmentalconitionsortoexternaldisturbances.I nthecaseofthefurnacecontrol,perhapsanexperiencedpersoncanprovidecontr olforacertaindesiredtemperatureinthehouse;butidthedoorsorwindowsareop enedorclosedintermittentlyduringtheoperatingperiod,thefinaltemperatureinsidethehousewillnotbeaccuratelyregulatedbytheopen-loopcontrol.Anelectricwashingmachineisanothertypicalexampleofanopen-loopsyst em,becausetheamountofwashtimeisentirelydeterminedbythejudgmentandesti mationofthehumanoperator.Atrueautomaticelectricwashingmachineshouldha vethemeansofcheckingthecleanlinessoftheclothescontinuouslyandturnitse dtoffwhenthedesireddegisedofcleanlinessisreached.Closed-LoopControlSystemsWhatismissingintheopen-loopcontrolsystemformoreaccurateandmoread aptablecontrolisalinkorfeedbackfromtheoutputtotheinputofthesystem.Ino rdertoobtainmoreaccuratebontrol,thecontrolledsignalc(t)mustbefedbacka ndcomparedwiththereferenceinput,andanactuatingsignalproportionaltothe differenceoftheoutputandtheinputmustbesentthroughthesystemtocorrectth eerror.Asystemwithoneormorefeedbackpat(slikethatjustdescribediscalled aclosed-loopsystem.humanbeingareprobablythemostcomplexandsophisticate dfeedbackcontrolsysteminexistence.Ahumanbeingmaybeconsideredtobeacont rolsystemwithmanyinputsandoutputs,capableofcarryingouthighlycomplexop erations.Toillustratethehumanbeingasafeedbackcontrolsystem,letusconsidert hattheobjectiveistoreachforanobjectonaperformthetask.Theeyesserveasas ensingdevicewhichfeedsbackcontinuouslythepositionofthehand.Thedistanc ebetweenthehandandtheobjectistheerror,whichiseventuallybroughttozeroa sthehandreachertheobject.Thisisatypicalexampleofclosed-loopcontrol.However,ifoneistoldtoreachfortheobjectandthenisblindolded,onecanonlyrea chtowardtheobjectbyestimatingitsexactposition.ItisAsantherillustrativ eexampleofaclosed-loopcontrolsystem,showstheblockdiagramoftherudderco ntrolsystemofThebasicalementsandtheblocadiagramofaclosed-loopcontrols ystemareshowninfig.Ingeneral,theconfigurationofafeedbackcontrolsystem maynotbeconstrainedtothatoffig&.Incomplexsystemstheremaybemultitudeof feedbackloopsandelementblocks.数控在先进制造技术领域最根本的观念之壹是数控（NC）。

数控技术外文翻译、数控编程外文文献翻译、中英文翻译

附录：外文资料与中文翻译外文资料：NC Technology1、Research current situation of NC lathe in our timesResearch and development process to such various kinds of new technologies as numerical control lathe , machining center , FMS , CIMS ,etc. of countries all over the world, linked to with the international economic situation closely. The machine tool industry has international economy to mutually promote and develop, enter 21 alert eras of World Affairs, the function that people's knowledge plays is more outstanding, and the machine tool industry is regarded as the foundation of the manufacturing industry of the machine, its key position and strategic meaning are more obvious. Within 1991-1994 years, the economic recession of the world, expensive FMS, CIMS lowers the temperature, among 1995-2000 years, the international economy increases at a low speed, according to requisition for NC lathe and the world four major international lathes exhibition in order to boost productivity of users of various fields of present world market (EMO , IMTS , JIMTOF , China CIMT of Japan of U.S.A. of Europe), have the analysis of the exhibit, there are the following several points mainly in the technical research of NC lathe in our times:1.1、Pay more attention to new technology and innovationWorldwide , are launching the new craft , new material , new structure , new unit , research and development of the new component in a more cost-effective manner, developmental research of for instance new cutter material , the new electric main shaft of main shaft structure , high speed , high-speed straight line electrical machinery ,etc.. Regard innovating in improvement of the processing technology as the foundation, for process ultra and hard difficult to cut material and special composite and complicated part , irregular curved surface ,etc. research and develop new lathe variety constantly.1.2、Improve the precision and research of machine toolingIn order to improve the machining accuracy of the machining center , are improving rigidity of the lathe , reduction vibration constantly, dispel hotly and out of shape, reduce the noise , improve the precision of localization of NC lathe , repeat precision , working dependability , stability , precision keeping, world a lot of country carry on lathe hot error , lathe sport and load out of shape software of error compensate technical research, take precision compensate , software compensate measure improve , some may make this kind of error dispel 60% already. And is developing retrofit constantly, nanometer is being processed. 1.3、Improve the research of the machine tooling productivityWorld NC lathe, machining center and corresponding some development of main shaft, electrical machinery of straight line, measuring system, NC system of high speed, under the prerequisite of boosting productivity.1.4、What a lot of countries have already begun to the numerical control system melt intelligently, openly, study networkedlyA、Elegant research of the numerical control systemMainly showing in the following aspects: It is intelligent in order to pursue the efficiency of processing and process quality, the self-adaptation to the processing course is controlled, the craft parameter produces research automatically; Join the convenient one in order to improve the performance of urging and use intelligently, to the feedback control , adaptive operation , discerning automatically load selects models automatically , since carries on research whole definitely ,etc. of the electrical machinery parameter; There are such research of the respect as intelligent automatic programming , intelligent man-machine interface , intelligence diagnosing , intelligent monitoring ,etc..B、 The numerical control system melts and studies openMainly showing in the following aspects: The development of the numerical control system is on unified operation platform, face the lathe producer and support finally, through changing, increasing or cutting out the structure target(numerical control target ), form the seriation, and can use users specially conveniently and the technical know-how is integrated in thecontrol system, realize the open numerical control system of different variety , different grade fast, form leading brand products with distinct distinction. System structure norm of the open numerical control system at present, norm, disposing the norm, operation platform, numerical control systematic function storehouse and numerical control systematic function software developing instrument, etc. are the core of present research to pass through.C、Meeting the manufacture system of the production line , demand for the information integration of the manufacturing company networkedly greatly of numerical control equipment, it isa basic unit of realizing the new manufacture mode too.2、Classification of the machining center2.1、Process according to main shaft space position when it classifies to be as follows, horizontal and vertical machining center.Horizontal machining center, refer to the machining center that the axis level of the main shaft is set up. Horizontal machining center for 3-5 sport coordinate axis, a common one three rectilinear motion coordinate axis and one turn the coordinate axis of sports round (turn the working bench round), it can one is it is it finish other 4 Taxi processing besides installing surfaces and top surfaces to insert to install in work piece, most suitable for processing the case body work piece. Compared with strength type machining center it, the structure is complicated, the floor space is large, quality is large, and the price is high.Vertical machining center, the axis of the main shaft of the vertical machining center, in order to set up vertically, its structure is mostly the regular post type, the working bench is suitable for processing parts for the slippery one of cross, have 3 rectilinear motion coordinate axis generally, can find a room for one horizontal numerical control revolving stage (the 4th axle) of axle process the spiral part at working bench. The vertical machining center is of simple structure, the floor space is small, the price is low, after allocating various kinds of enclosures, can carry on the processing of most work pieces.Large-scale gantry machining center, the main shafts are mostly set up vertically, is especially used in the large-scaleor with complicated form work piece , is it spend the many coordinate gantry machining center to need like aviation , aerospace industry , some processing of part of large-scale steam turbine.Five machining centers, this kind of machining center has function of the vertical and horizontal machining center, one is it after inserting, can finish all five Taxi processing besides installing the surface to install in work piece, the processing way can make form of work piece error lowest, save 2 times install and insert working, thus improve production efficiency, reduce the process cost.2.2、Classify by craft useIs it mill machining center to bore, is it mill for vertical door frame machining center, horizontal door frame mill the machining center and Longman door frame mill the machining center to divide into. Processing technology its rely mainly on the fact that the door frame is milled, used in case body, shell and various kinds of complicated part special curve and large processes , curved surface of outline process, suitable for many varieties to produce in batches small.Complex machining center, point five times and compound and process mainly, the main shaft head can be turned round automatically, stand, lie and process, after the main shaft is turned round automatically, realize knowing that varies in the horizontal and vertical direction.2.3、Classify by special functionSingle workingbench, a pair of working bench machining center;Single axle, dual axle, three axle can change machining center, main shaft of case;Transfer vertically to the tower machining center and transfer;One hundred sheets of storehouses add the main shaft and changes one one hundred sheets of machining centers;One hundred sheets of storehouses connects and writes hands to add the main shaft and change one hundred sheets of machining centers;One hundred sheets of storehouses adds the manipulator andadds one pair of main shafts to transfer to the tower machining center.3、Development trend of the current numerical control latheAt present, the advanced manufacturing technology in the world is rising constantly, such application of technology as ultra fast cutting , ultra precision processing ,etc., the rapid development of the flexible manufacturing system and integrated system of the computer one is constant and ripe, have put forward higher demand to the process technology of numerical control. Nowadays the numerical control lathe is being developed in several following directions.（1）.The speed and precision at a high speed , high accuracy are two important indexes of the numerical control lathe , it concerns directly that processes efficiency and product quality. At present, numerical control system adopt-figure number, frequency high processor, in order to raise basic operation speed of system. Meanwhile , adopt the super large-scale integrated circuit and many microprocessors structure, in order to improve systematic data processing ability , namely improve and insert the speed and precision of mending operation. Adopt the straight line motor and urge the straight line of the lathe working bench to be servo to enter to the way directly, it is quite superior that its responds the characteristic at a high speed and dynamically. Adopt feed forward control technology, make it lag behind error reduce greatly , thus improve the machining accuracy cut in corner not to track.For meet ultra fast demand that process, numerical control lathe adopt main shaft motor and lathe structure form that main shaft unite two into one, realize frequency conversion motor and lathe main shaft integrate , bearing , main shaft of electrical machinery adopt magnetism float the bearing , liquid sound pigeonhole such forms as the bearing or the ceramic rolling bearing ,etc.. At present, ceramic cutter and diamond coating cutter have already begun to get application.(2). Multi-functional to is it change all kinds of machining centers of organization (a of capacity of storehouse can up to 100of the above ) automatically to furnished with, can realize milling paring , boring and pares , bores such many kinds of processes as paring , turning , reaming , reaming , attacking whorl ,etc. to process at the same time on the same lathe , modern numerical control lathe adopt many main shaft , polyhedron cut also , carry on different cutting of way process to one different position of part at the same time. The numerical control system has because adopted many CPU structure and cuts off the control method in grades, can work out part processing and procedure at the same time on a lathe, realize so-called “the front desk processes, the backstage supporter is an editor ". In order to meet the needs of integrating the systematic one in flexible manufacturing system and computer, numerical control system have remote serial interface , can network , realize data communication , numerical control of lathe, can control many numerical control lathes directly too.(3).Intelligent modern numerical control lathe introduce the adaptive control technology, according to cutting the change of the condition, automatic working parameter, make the processing course can keep the best working state, thus get the higher machining accuracy and roughness of smaller surface, can improve the service life of the cutter and production efficiency of the equipment at the same time. Diagnose by oneself, repair the function by oneself, among the whole working state, the system is diagnosed, checked by oneself to CNC system and various kinds of equipment linking to each other with it at any time. While breaking down, adopt the measure of shutting down etc. immediately, carry on the fault alarm, brief on position, reason to break down, etc.. Can also make trouble module person who take off automatically, put through reserve module, so as to ensure nobody demand of working environment. For realize high trouble diagnose that requires , its development trend adopts the artificial intelligence expert to diagnose the system.(4).Numerical control programming automation with the development of application technology of the computer, CAD/CAM figure interactive automatic programming has already get more application at present, it is a new trend of the technical development of numerical control. It utilize part that CAD drawprocess pattern , is it calculate the trailing punishing to go on by cutter orbit data of computer and then, thus produce NC part and process the procedure automatically, in order to realize the integration of CAD and CAM. With the development of CIMS technology , the full-automatic programming way in which CAD/CAPP/CAM integrates has appeared again at present, it, and CAD/CAM systematic programming great difference their programming necessary processing technology parameter needn't by artificial to participate in most, get from CAPP database in system directly.(5). the dependability of the dependability maximization numerical control lathe has been the major indicator that users cared about most all the time. The numerical control system will adopt the circuit chip of higher integrated level, will utilize the extensive or super large-scale special-purpose and composite integrated circuit, in order to reduce the quantity of the components and parts, to improve dependability. Through the function software of the hardware, in order to meet various kinds of demands for controlling the function, adopt the module, standardization, universalization and seriation of the structure lathe noumenonn of the hardware at the same time, make not only improve the production lot of the hardware but also easy to is it produce to organize and quality check on.. Still through operating and starting many kinds of diagnostic programs of diagnosing, diagnosing, diagnosing off-line online etc. automatically, realize that diagnoses and reports to the police the trouble to hardware, software and various kinds of outside equipment in the system. Utilize the warning suggestion, fix a breakdown in time; Utilize fault-tolerant technology, adopt and design the important part " redundantly ", in order to realize the trouble resumes by oneself; Utilize various kinds of test, control technology, exceed Cheng, one one hundred sheets of damages, interfering, cutting out,etc. at the time of various kinds of accidents as production, carry on corresponding protection automatically.(6).Control system miniaturization systematic miniaturization of numerical control benefit and combine the machine , electric device for an organic whole. Adopt the super large-scale integrated component , multi-layer printed circuit board mainly at present, adopt the three-dimensional installationmethod , make the electronic devices and components must use the high density to install, narrow systematic occupying the space on a larger scale. And utilize the new-type slim display of colored liquid crystal to substitute the traditional cathode ray tube, will make the operating system of numerical control miniaturize further. So can install it on the machine tool conveniently, benefit the operation of the numerical control lathe correctly even more.中文翻译：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。

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。

数控铣床外文翻译(英)

Vision Assisted NC Milling Path GenerationWith the rapid development of computer technology, Fundamentally changing the traditional manufacturing industry，the industrial developed countries spent huge sums of money on the modern manufacturing technology research and development, to create a new model. In modern manufacturing systems, CNC technology is the key to technology, which combines microelectronics, computers, information processing, automatic detection, automatic control, such as the integration of advanced, a high-precision, high-efficiency, flexible automation, and other characteristics, the manufacturing industry Flexible automation, integrated, intelligent play the pivotal role. At present, NC technology is undergoing a fundamental change, from a special closed-loop control mode to general-purpose real-time dynamic open all closed-loop control mode. In the integrated on the basis of the CNC systems ultra-thin, ultra-light; on the basis of the intelligent, integrated computers, multimedia, fuzzy control, neural network and other technical disciplines, NC system to achieve high-speed, high-precision, Efficient control, automatic processing can be amended to regulate compensation and the parameters for an online intelligent fault diagnosis and treatment of the network based on the CAD / CAM and CNC systems integration as one machine network, makes the central government centralized control of the group control processing。

机床数控化改造外文文献翻译、中英文翻译

外文资料First, CNC of the need for transformation1.1, microscopic view of the necessity ofFrom the micro perspective, CNC machine tools than traditional machines have the following prominent superiority, and these advantages are from the NC system includes computer power.1.1.1 can be processed by conventional machining is not the curve, surface and other complex partsBecause computers are superb computing power can be accurately calculated instantaneous each coordinate axis movement exercise should be instantaneous, it can compound into complex curves and surfaces.1.1.2 automated processing can be achieved, but also flexible automation to increase machine efficiency than traditional 3 to 7 times.Because computers are memory and storage capacity, can be imported and stored procedures remember down, and then click procedural requirements to implement the order automatically to achieve automation. CNC machine tool as a replacement procedures, we can achieve another work piece machining automation, so that single pieces and small batch production can be automated, it has been called "flexible automation."1.1.3 high precision machining parts, the size dispersion of small, easy to assemble, no longer needed "repair."1.1.4 processes can be realized more focused, in part to reduce the frequent removal machine.1.1.5 have automatic alarm, automatic control, automatic compensation, and other self-regulatory functions, thus achieving long unattended processing.1.1.6 derived from the benefits of more than five.Such as: reducing the labor intensity of the workers, save the labor force (onecan look after more than one machine), a decrease of tooling, shorten Trial Production of a new product cycle and the production cycle, the market demand for quick response, and so on.These advantages are our predecessors did not expect, is a very major breakthrough. In addition, CNC machine tools or the FMC (Flexible Manufacturing Cell), FMS (flexible manufacturing system) and CIMS (Computer Integrated Manufacturing System), and other enterprises, the basis of information transformation. NC manufacturing automation technology has become the core technology and basic technology.1.2, the macro view of the necessityFrom a macro perspective, the military industrial developed countries, the machinery industry, in the late 1970s, early 1980s, has begun a large-scale application of CNC machine tools. Its essence is the use of information technology on the traditional industries (including the military, the Machinery Industry) for technological transformation. In addition to the manufacturing process used in CNC machine tools, FMC, FMS, but also included in the product development in the implementation of CAD, CAE, CAM, virtual manufacturing and production management in the implementation of the MIS (Management Information System), CIMS, and so on. And the products that they produce an increase in information technology, including artificial intelligence and other content. As the use of information technology to foreign forces, the depth of Machinery Industry (referred to as information technology), and ultimately makes their products in the international military and civilian products on the market competitiveness of much stronger. And we in the information technology to transform traditional industries than about 20 years behind developed countries. Such as possession of machine tools in China, the proportion of CNC machine tools (CNC rate) in 1995 to only 1.9 percent, while Japan in 1994 reached 20.8 percent, every year a large number of imports of mechanical and electrical products. This also explains the macro CNC transformation of the need.Second, CNC machine tools and production lines of the transformation of the market2.1, CNC transformation of the marketMy current machine total more than 380 million units, of which only the total number of CNC machine tool 113,400 Taiwan, or that China's CNC rate of less than 3 percent. Over the past 10 years, China's annual output of about 0.6 CNC machine tools to 0.8 million units, an annual output value of about 1.8 billion yuan. CNC machine tools annual rate of 6 per cent. China's machine tool easements over age 10 account for more than 60% below the 10 machines, automatic / semi-automatic machine less than 20 per cent, FMC / FMS, such as a handful more automated production line (the United States and Japan automatic and semi-automatic machine, 60 percent above). This shows that we the majority of manufacturing industries and enterprises of the production, processing equipment is the great majority of traditional machine tools, and more than half of military age is over 10 years old machine. Processing equipment used by the prevalence of poor quality products, less variety, low-grade, high cost, supply a long period, in view of the international and domestic markets, lack of competitiveness, and a direct impact on a company's products, markets, efficiency and impact The survival and development of enterprises. Therefore, we must vigorously raise the rate of CNC machine tools.2.2, import equipment and production lines of the transformation of NC marketSince China's reform and opening up, many foreign enterprises from the introduction of technology, equipment and production lines for technological transformation. According to incomplete statistics, from 1979 to 1988 10, the introduction of technological transformation projects are 18,446, about 16.58 billion US dollars.These projects, the majority of projects in China's economic construction play a due role. Some, however, the introduction of projects due to various reasons, not equipment or normal operation of the production line, and even paralyzed, and the effectiveness of enterprises affected by serious enterprise is in trouble. Some of the equipment, production lines introduced from abroad, the digestion and absorption of some bad, spare parts incomplete, improper maintenance, poor operating results; onlypay attention to the introduction of some imported the equipment, apparatus, production lines, ignore software, technology, and management, resulting in items integrity, and potential equipment can not play, but some can not even start running, did not play due role, but some production lines to sell the products very well, but not because of equipment failure production standards; because some high energy consumption, low pass rate products incur losses, but some have introduced a longer time, and the need for technological upgrading. Some of the causes of the equipment did not create wealth, but consumption of wealth.These can not use the equipment, production lines is a burden, but also a number of significant assets in stock, wealth is repaired. As long as identifying the main technical difficulties, and solve key technical problems, we can minimize the investment and make the most of their assets in stock, gain the greatest economic and social benefits. This is a great transformation of the market.Third, NC transformation of the content and gifted missing3.1, the rise of foreign trade reformIn the United States, Japan and Germany and other developed countries, and their machine transform ation as new economic growth sector, the business scene, is in a golden age. The machine, as well as technology continues to progress, is a machine of the "eternal" issue. China's machine tool industry transformation, but also from old industries to enter the CNC technology mainly to the new industries. In the United States, Japan, Germany, with CNC machine tools and technological transformation of production lines vast market, has formed a CNC machine tools and production lines of the new industry. In the United States, transforming machine tool industry as renewable (Remanufacturing) industry. Renewable industry in the famous companies: Borsches engineering company, atoms machine tool company, Devlieg-Bullavd (Bo) services group, US equipment companies. Companies in the United States-run companies in China. In Japan, the machine tool industry transformation as machine modification (Retrofitting) industry. Conversion industry in the famous companies: Okuma engineering group, Kong 3 Machinery Company, Chiyoda Engineering Company, Nozaki engineering company, Hamada engineeringcompanies, Yamamoto Engineering Company.3.2, the content of NCMachine tools and production line NC transformation main contents of the following:One is the restoration of the original features of the machine tools, production line of the fault diagnosis and recovery; second NC, in the ordinary machine augends significant installations, or additions to NC system, transformed into NC machine tools, CNC machine tools; its Third, renovation, to improve accuracy, efficiency and the degree of automation, mechanical, electrical part of the renovation, re-assembly of mechanical parts processing, restore the original accuracy of their production requirements are not satisfied with the latest CNC system update; Fourth, the technology updates or technical innovation, to enhance performance or grades, or for the use of new technology, new technologies, based on the original technology for large-scale update or technological innovation, and more significantly raise the level, and grades of upgrading.3.3, NC transformation of the gifted missing3.3.1 reduce the amount of investment, shorter delivery timeCompared with the purchase of new machine, the general can save 60% to 80% of the costs and transforming low-cost. Especially for large, special machine tools particularly obvious. General transformation of large-scale machine, spent only the cost of the new machine purchase 1 / 3, short delivery time. But some special circumstances, such as high-speed spindle, automatic tray switching systems and the production of the installation costs too costly and often raise the cost of 2 to 3 times compared with the purchase of new machine, only about 50 percent of savings investment.3.3.2 stable and reliable mechanical properties, structure limitedBy the use of bed, column, and other basic items are heavy and solid casting components, rather than kind of welding components of the machine after the high-performance, quality, and can continue to use the new equipment for many years. But by the mechanical structure of the original restrictions, it is not appropriate to thetransformation of a breakthrough.3.3.3 become familiar with the equipment, ease of operation and maintenanceThe purchase of new equipment, new equipment do not know whether to meet the processing requirements. Transformation is not, can be used to calculate the machine processing capacity; In addition, since the use of many years, the operator of the machine has long been understood that in the operation, use and maintenance of the training time is short, quick. Transformation of the machine tools installed, we can achieve full load operation.3.3.4 can take full advantage of the existing conditionsTake full advantage of the existing foundation, not like buying new equipment as necessary to build a foundation.3.3.5 can be used as control technologyAccording to the development speed of technological innovation and in a timely manner increased level of automation in production equipment and efficiency, improve the quality of equipment and grades, and the old machine will be replaced by the current level of machine.Fourth, the main steps of CNC machine tools4.1, for the determination of transformationThrough analysis of the feasibility of transforming the future, we can against a Taiwan or a few machines determine the current status of reform programmes, which are generally include:4.1.1 mechanical and electrical repair of combiningGenerally speaking, the need for a transformation of the electrical machine, are subject to mechanical repairs. Repairs to determine the requirements, scope, content must be decided by electrical machinery required to transform the structure of the request; transformation to determine electrical and mechanical repair, alteration between the staggered time requirements. The mechanical properties of intact electrical transform the basis of success.4.1.2 easy first, and to the overall situation after the first localThe removal of the original system must control the original drawings, carefully, to make drawings in a timely manner marked to prevent the demolition or omission (of local circumstances). In the process of demolition will discover some new system design in the gaps, and that should be promptly added, removed and parts of the system should be disaggregated, safekeeping, in case of failure or partial failure reinstated. There is a definite value, and can be used for spare parts for other machines. Must not extravagantly used and misplaced.4.2 reasonable arrangements for a new location and routing systemUnder the new system design drawings and reasonable new system configurations, including fixed box, panel installation, alignments, and the fixed position adjustment components, sealing and necessary, such as decoration. Connection must be a clear division of work, it was reviewed inspection to ensure connectivity of norms, diameter appropriate, accurate, reliable handsome.4.3 DebuggingCommissioning must be identified in advance by the steps and requirements. Debugging should be cool-headed, keep records, in order to identify a nd solve problems. Commissioning of the first test sensitivity security protection systems to prevent physical, equipment accidents. Debugging the scene must be cleaned, no superfluous items; coordinates extension units in the campaign centre of the whole trip; empty can test, first empty after loading; can simulate the test, after the first real dynamic simulation; can manually the upper hand After moving automatically.4.4, acceptance and post-workAcceptance of the work to employ the staff to join, has been developed in accordance with the acceptance criteria. The transformation of the late work is also very important, it is conducive to enhancing the level of technical projects and equipment as soon as possible so that production. Acceptance and post include:4.4.1 machine mechanical properties acceptanceAfter mechanical repairs and maintenance as well as a full transformation, the mechanical properties of the machine tools should meet the requirement, in the geometric accuracy should be within the limits prescribed.4.4.2 electrical control function and control accuracy acceptanceElectrical control the various functions of action must be normal, sensitive and reliable. Application control accuracy of the system itself functions (such as stepping dimensions, etc.) and standard measurement apparatus (such as laser interferometer, coordinate measurement machines) inspection, the scope of accuracy achieved. At the same time also and the transformation of the former machine tool accuracy of the various functions and to contrast, poor access to quantifiable indicators.4.4.3 specimen cutting AcceptanceYou can refer to the CNC machine tool cutting at home and abroad specimen standards, qualified operatives, with the programming staff to test cutting. Acceptance specimen cutting machine stiffness can be cutting, noise, trajectory, and other related actions, the general should not be used for product components specimen use.4.4.4 drawings, information acceptanceMachine transformation of the latter should be timely drawings (including schematics, layout plans, wiring diagram, ladder diagram, etc.), information (including various brochures), the transformation of files (including the transformation before and after the various records) summary, collating, transfer to stall. Maintain data integrity, effective, continuous, and that the future stability of the equipment running is very important.4.4.5 summing up, enhancingAfter the end of each should be promptly summed up, helps improve the operational level of technical personnel, but also conducive to the whole enterprise technical progress.中文译文一、机床数控化改造的必要性1.1、微观看改造的必要性从微观上看，数控机床比传统机床有以下突出的优越性，而且这些优越性均来自数控系统所包含的计算机的威力。

数控机床外文文献翻译、中英文翻译

数控机床外文文献翻译、中英文翻译原文一CNC machine toolsOutdate, J. and Joe, J. Configuration Synthesis of Machining Centers with Tool，JohnWiley & sons, 2001While 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 work 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 and accurate work pieces. T oday'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 toolsis 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 (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 feedbackdevice (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 toolThough 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 systemsIt 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 forthe 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. Refer to fig.2, 3.fig.2, 3.Understanding absolute versus incremental motionAll 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), endpoints 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 incrementally. 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 movement 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 possiblyat 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 G54Flexible manufacturing cellsA 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 thecentral computer. Instead, instructions from the centralcomputer are passed to the cell controller.2.The cell is limited in the number of part families itcan manufacture.The following elements are normally found in an FMC:Cell controllerProgrammable logic controller (PLC)More than one machine toolA 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. Refer to fig.5 for the cutting data designations and for mulas. 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:Fig.5 cutting datarough machining and semi-finishing of the material in its soft (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 tools) finishing and super-finishing of cylindrical/flat/cavity surfaces with appropriate cemented carbide, cermets, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN)For many components, the production process involves acombination 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 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 HSMSurvivalThe 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 thisarea. 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 newand optimized functions and features. 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 equipmentThe strong development of cutting materials, holding tools, machine tools, controls and 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...".See fig.6.Fig.6 chip removal temperature as a result of the cutting speedGiven 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 verifythis 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 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 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 troubleshooting Maintenance for a horizontal MCThe following is a list of required regular maintenance for a 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 centerDailyTop 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.WeeklyCheck for proper operation of auto drain on filter regulator. See fig. 8Fig. 8 way lube and pneumaticsOn 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 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 usesolvents.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.AnnuallyReplace 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.TroubleshootingThis 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 miss-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 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 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 itWON'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.译文一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。

机械类数控外文翻译外文文献英文文献数控

机械类数控外文翻译外文文献英文文献数控IntroductionIn recent years, with the rapid development of science and technology, the traditional manufacturing industry has been facing tremendous challenges. In this context, computerized numerical control (CNC) technology has emerged as a revolutionary methodology that greatly improves the efficiency and accuracy of manufacturing processes. Specifically, CNC technology is a type of automated control system that uses a set of computer instructions to direct the movement and operation of machinery in the manufacturing process. In this regard, this paper will provide a comprehensive overview of CNC technology, including its history, applications, advantages, and challenges.History of CNC TechnologyCNC technology has a history that can be traced back to the 1940s. At that time, the aviation industry in the United States was seeking a way to improve the efficiency and accuracy of manufacturing. Therefore, the US Air Force and the Massachusetts Institute of Technology (MIT) cooperated to develop a system that automatically controlled the movement ofaircraft components during the manufacturing process. This system was called the numerical control (NC) system.In the mid-1950s, John Parsons, a researcher at the Massachusetts Institute of Technology, invented the first NC machine tool. The machine used punched tape to control the movement of the cutting tool. During the 1960s, digital computer technology became more advanced, which paved the way for the development of CNC machines. By 1970, CNC machines had become a mature and widely used technology in the manufacturing industry.Applications of CNC TechnologyCNC technology has a wide range of applications in the manufacturing industry. For example, CNC machines can be used to produce a variety of products, including automobile parts, aircraft components, medical equipment, and consumer goods. CNC technology is also used in many other industries, such as woodworking, metalworking, plastics, and textiles.CNC technology has revolutionized the manufacturing industry by improving the quality, precision, and consistency of products. In addition, CNC machines can work faster and often require less manual labor than traditional manufacturing methods. CNC technology also allows manufacturers to produce complex shapes and designs that would be difficult or impossible to produce using traditional manufacturing methods.Advantages of CNC TechnologyThere are several advantages of using CNC technology in manufacturing. First, CNC machines can produce parts with very high precision and accuracy, which is crucial in industries such as aerospace and medical equipment manufacturing. CNC machines can also work 24/7, which means that manufacturers can produce parts at any time of day or night without having to worry about workers becoming tired.Second, CNC machines are highly flexible and can be programmed to produce a wide range of products. This means that manufacturers can quickly switch between different products without having to buy new machines or invest in expensive retooling. This flexibility also allows manufacturers to respond quickly to changes in market demand.Third, CNC machines can greatly reduce the amount of waste generated during the manufacturing process. This is because CNC machines can accurately measure and cut materials, minimizing the amount of scrap that is created. In addition, CNC machines can be programmed to optimize the use of materials, further reducing waste.Challenges of CNC TechnologyDespite its many advantages, CNC technology also presents several challenges. First, CNC machines can be expensive to purchase and maintain, which can be a barrier for smallmanufacturers. In addition, CNC machines require skilled operators who can program and operate the machines. This means that manufacturers must invest in training their workers, which can also be costly.Second, CNC machines can sometimes be less efficient than traditional manufacturing methods for small production runs. This is because CNC machines require a certain amount of time to set up and program, which can be inefficient for small production runs. In addition, CNC machines require a certain amount of precision, which means that they may not be suitable for certain types of products, such as handmade crafts.Finally, CNC machines also present some ethical challenges. For example, some argue that CNC machines could lead to job loss in the manufacturing industry, as the machines can perform tasks that were previously done by workers. In addition, CNC machines could lead to a reduction in the quality of products, as manufacturers may be more focused on speed and efficiency rather than quality.ConclusionCNC technology has revolutionized the manufacturing industry by improving the quality, precision, and consistency of products. CNC machines are highly flexible and can be programmed to produce a wide range of products. In addition, CNC machines can greatly reduce the amount of waste generated during the manufacturing process. However, CNC technology alsopresents several challenges, including high cost, the need for skilled operators, efficiency issues for small production runs, and ethical concerns. Overall, CNC technology is a powerful tool for manufacturers, but it is important for manufacturers to carefully consider the costs and benefits of using this technology.。

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。

数控技术课程毕业设计外文文献翻译、中英文翻译、外文翻译

数控技术数字控制与计算机数字控制的发展历史数字控制是按照含有机床(刀具)运动信息程序所指定的顺序自动执行操作的加工过程。

数控这一概念是由密歇根洲特拉华城的约翰·帕森于20世纪四十年代后期提出的。

为了在工件上加工光滑的轮廓，帕森提出了一种自动的机床控制方式，它能够引导铣床刀具加工出一种“过轴曲线”。

1949年，美国空军与帕森签署了合同，要求开发一种能够提高生产率的新型机床。

帕森委托麻省理工学院(MIT)来开发一种新概念机床，麻省理工学院的科学家和工程师研制出了一种用穿孔纸带作为输入媒介的二轴联动铣床控制系统。

在较短时间内，当时所有主要的机床生产商都生产了一些数控机床，但直到20世纪七十年代后期，基于计算机的数字控制才被得到广泛的使用。

只有价格低廉且功能强大的微处理芯片代替了计算机数控系统中的硬连线逻辑发生器后，NC才真正成为一门自动化技术。

当数控机床在计算机监控下工作时，它就被称为计算机数控机床(CNC)。

计算机是CNC机床的控制单元，它们内嵌于数控机床或者通过通讯渠道与数控机床联接，当程序员编程时，通过纸带或磁盘将一些信息输入，计算机将对一些必要的数据进行计算的完成工作。

由于第一台数控机床的数据是由纸带控制的，因此数控系统被称为纸带控制机床。

它们只能控制由输入到机床内的纸带或磁带所规定的单一操作，输入到机床内的程序是不能被编辑的，要改变程序必须重做新纸带。

当今的系统都由计算机来控制数据，因而称之为计算机数控机床(简称CNC机床)。

NC和CNC系统两者的工作原理一样，仅仅控制执行的方式不同。

新型的数控系统通常速度更快、功率更大、功能更齐全。

数字控制与计算机数字控制的应用数控技术自创立以来就得到了广泛的应用，包括车床和车削中心、铣床和加工中心、冲床、电火花(EDM)加工机床、线切割机床、磨床以及测试检测装置等。

最复杂的计算机数控机床是车削中心，图4—1所示一个具有十转位的刀架能进行快速换刀的现代车削中心，立式加工中心如图4—2所示(刀具库在机床的左边。

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附录3外文文献Design of Movable Gantry CNC Milling MachineZHANG JianAbstract:this paper describes the nc milling roller, the overall design and analyses the bilateralsuper-modulus gear pair of driving mechanism of the main points of design,installationguidesurface of the X axis is introduced in this paper Keywords:mobile nc milling designT his machine is mainly used for metal parts of the plane and inclined plane work. It has enough rigidity, Milling head adopts milling head in Taiwan, Milling head with flexible, Spindle motor is frequency conversion motor. It can undertake stepless speed, Ensure accuracy of machine tools and machining precision has good stability, This machine is of high efficiency and exercise,For convenience, make the drive more reliable and convenient in maintenance, less consumption, beautiful modelling, etc, widely used in mechanical manufacturing industry.This paper described the mobile CNC milling refers to longmen framework Vertical milling movement. The biggest advantage of milling roller is (1) Machine cover an area of an area small. Workbench mobile Longmen milling machine, complete machine must be higher than vertical stroke length two times. However, Workbench mobile Longmen milling machine, The length of side frame which is fabricated according to add only longitudinal travel width, Thedynamic response of the machine is good. Workbench mobile Longmen milling machine adopts fixed table. The whole cast out with bed, Longmen framework of longitudinal motionDrive torque equivalent unchanged, It is not because of bearing the weight of the workpiece changesChange, so as to ensure the accuracy and performance of the machine tool.The independent design mobile nc Longmen milling（FIG 1）has been a special machine to use. It can satisfy the large castings, steel parts boring and milling, drilling, etc multiple operation process. It is right milling head, It also can process the 4 side of workpiece. The goal of the main design parameters such as Longmen milling under: workbench area 1800mm ×4000mm, The travel for X axis:4000mm The travel for Y axis:2000mm The travel forZ axis:750mm, Spindle power 18.5KW, Each axis rapid federate 10m/min.Figure 1 Mobile nc milling1.Mechanical parts designThe bed include Bed, Slide, Longmen frame spindle box, Three axis to drive mechanical parts and related CNC servo part, Now ,The design process isemphasized as follows: The bed is the basic design work, The size of the bed of the design affects the complete machine design. And the rationality of the design of directly affect the whole Machine stiffness. The cross-section shape for the bed like ∏,(FIG 2) The plane is working on a bed of mesa design has 9 T shaped groove. For the convenience of bed and working mesa of pure dig imageT processing, groove tank completely, The right and left two concerning the design has a long narrow swing plane. It is used to linear rolling guide vice, The author put rail surface design in the two side bed. The main consideration of force transmission directions and unloading, Because the bed will be dragon framework of gravity, cutting force and the gravity of the workpiece, This design can directly into the gravity of longmen framework to machine tools, and Bed only suffer the gravity of the workpiece. The bed by the following basic wall thickness determine By the following formula.C=1/4(2L+B+H)Type: C,L,B is respectively for bed length, width and height of size and unit for the m.Based on equivalent size c, Consulting relevant form，Take the basic wall thickness is 38mm，Figure 2 Shape of concerning the cross-section Spindle box adopts 300 mm ×300 mm section design. The torsion bendingcapacity are stronger. Spindle gearboxes USES two gears Gear sliding speed-change mechanism.It can adapt rough machining requirements. Spindle unit adopts four supporting structure, Ahead three groups of Angle contact ball bearing used to withstand cutting force. Spindle end a deep groove ball bearings are used to unloading, That is not of the Sliding gears of the additional moment.Longmen framework used integral frame which is fabricated according to the design concept, It took about beam and column design into a whole. Although make casting and assembly adjusting difficulty, the whole framework of longmen rigid better, more important is to slide have assembled spindle box, etc. Slide is designed in the frame which is fabricated according to the geometrical dimensions and spindle box, According to the center axis of the guide bar as far as possible to face for the principle, The Z axis and the driver installation position in design, effectively reduce the weight of the slide.Designed to drive into the idea as follows, The X axis to driveUse the bilateral super-modulus gear pair aggravating preloading linear rolling guide vice.X axis and Y axis uses big diameter ball screw preloading vice hardened guide. Rail sliding parts attached engineering plastics, It avoids low when crawling phenomenon, and guide the design is inclined with adjustable device. This machine design make the whole machine to coordinate performance. The axis of the feeding speed and force get the optimal matching.Due to the longitudinal axis machine movement X, and is moving longmen framework of longmen framework weighed 10T, so the linear rolling guide rails to must choose.Because the ball rail system of small friction coefficient, very suitable for longmen framework of moving rigidity requirement.Guide the slider choose one type, each slide block dynamic load can achieve 10t. Considering the safety coefficient, every guide installation 2 slider. Longmen framework for the driver bilateral super-modulus gear pair (see chart 2), feed movement by 3 input, through two inclined gear motor shaft/and axis to 2, andthen by two gear - and to drive rack. And thus promote longmen framew3 the helical gear axle spiral of the two opposite directions. Through the spring in the shaft on a three axial force F, make the helical gear trace of axial movement produced at 1 and 2 and axial shaft in the opposite direction Angle of small, round 4 and 5) respectively, the gear tooth surface with two rack, eliminate the gap.1.2.3--- axis 4.5--- RackFigure 3 Bilateral super-modulus gear pairSpindle box and vertical motion Z axis adopts ball screw assembly transmission. Because of this machine is not high speed milling machine, the Z axis of the feeding system for servo motor through the ratio of 4 for parallel axis set than gearbox drives the ball screw rotation. In the design of special attention to the Z axis of safety problems. First choose the servo motor with electromagnetic brake, second in the ball screw with a two-way overrunning clutch, prevent ball nuts rotation caused spindle box mechanical prolapse. Of course, in order to protect the z-axis feed institutions, but also in the accuracywith two balance on the slide cylinders. Balance Q, etcThe quality of parts in spindle box 85%.Spindle box around move for the Y axis, in order to guarantee the precision Y axis, and only by their level of ball screw and axial force, servo motor and the ball screw straight league. The author selects the coupling with overload protection device, in the overload when coupling automatically.2 Selection of CNC systemThe Siemens numerical control system is adopted, because this system 840D provides longmen shaft synchronization function. Use this function, the machine can to dragonsDoor frame for shaft (into) no, X2 clamps its X1 mechanical deviation of displacement. The actual value can exercise for comparison, even the smallest deviation can be corrected, and therefore improve the accuracy of the X axis movement3 EpilogueThe author finally, according to the professional machine parts manufacturers to provide design samples design will reach the twice the result with half the effort. In The design process, the author of CNC system, spindle unit, gearbox, super-modulus gear and ball screw guide etc. According to the sample of empirical formulas, not only shorten design time, make the higher reliability. At the same time we must pay great attention to the timely design machine tools, such as the application of three-dimensional software components immediately after the establishment sketches for 3d model, through the assembly interference, machine avoid collisions occur when in assembly Wade rework phenomenon.[翻译]移动式数控龙门铣床的总体设计张坚摘要：阐述了移动式数控龙门铣床的总体设计，并重点分析了双边齿轮齿条副驱动机构的设计要点，对X轴的导轨安装面作了介绍。