机械专业外文文献翻译
机械专业外文文献翻译
翻译部分英文原文High-speed machining and demand for the development ofHigh-speed machining is contemporary advanced manufacturing technology an important component of the high-efficiency, High-precision and high surface quality, and other features. This article presents the technical definition of the current state of development of China's application fields and the demand situation.High-speed machining is oriented to the 21st century a new high-tech, high-efficiency, High-precision and high surface quality as a basic feature, in the automobile industry, aerospace, Die Manufacturing and instrumentation industries gained increasingly widespread application, and has made significant technical and economic benefits. contemporary advanced manufacturing technology an important component part.HSC is to achieve high efficiency of the core technology manufacturers, intensive processes and equipment packaged so that it has a high production efficiency. It can be said that the high-speed machining is an increase in the quantity of equipment significantly improve processing efficiency essential to the technology. High-speed machining is the major advantages : improve production efficiency, improve accuracy and reduce the processing of cutting resistance.The high-speed machining of meaning, at present there is no uniform understanding, there are generally several points as follows : high cutting speed. usually faster than that of their normal cutting 5 -10 times; machine tool spindle speed high, generally spindle speed in -20000r/min above 10,000 for high-speed cutting; Feed at high velocity, usually 15 -50m/min up to 90m/min; For different cutting materials and the wiring used the tool material, high-speed cutting the meaning is not necessarily the same; Cutting process, bladed through frequency (Tooth Passing Frequency) closer to the "machine-tool - Workpiece "system the dominant natural frequency (Dominant Natural Frequency), can be considered to be high-speed cutting. Visibility high-speed machining is a comprehensive concept.1992. Germany, the Darmstadt University of Technology, Professor H. Schulz in the 52th on the increase of high-speed cutting for the concept and the scope, as shown in Figure 1. Think different cutting targets, shown in the figure of the transition area (Transition), to be what is commonly called the high-speed cutting, This is also the time of metal cutting process related to the technical staff are looking forward to, or is expected to achieve the cutting speed.High-speed machining of machine tools, knives and cutting process, and other aspects specific requirements. Several were from the following aspects : high-speed machining technology development status and trends.At this stage, in order to achieve high-speed machining, general wiring with high flexibility of high-speed CNC machine tools, machining centers, By using a dedicated high-speed milling, drilling. These equipment in common is : We must also have high-speed and high-speed spindle system feeding system, Cutting can be achieved in high-speed process. High-speed cutting with the traditional cutting the biggest difference is that "Machine-tool-workpiece" the dynamic characteristics of cutting performance is stronger influence. In the system, the machine spindle stiffness, grip or form, a long knife set, spindle Broach, torque tool set, Performance high-speed impact are important factors.In the high-speed cutting, material removal rate (Metal Removal Rate, MRR), unit time that the material was removed volume, usually based on the "machine-tool-workpiece" whether Processing System "chatter." Therefore, in order to satisfy the high-speed machining needs, we must first improve the static and dynamic stiffness of machine spindle is particularly the stiffness characteristics. HSC reason at this stage to be successful, a very crucial factor is the dynamic characteristics of the master and processing capability.In order to better describe the machine spindle stiffness characteristics of the project presented new dimensionless parameter - DN value, used for the evaluation of the machine tool spindle structure on the high-speed machining of adaptability. DN value of the so-called "axis diameter per minute speed with the product." The newly developed spindle machining center DN values have been great over one million. To reduce the weight bearing, but also with an array of steel products than to the much more light ceramic ball bearings; Bearing Lubrication most impressive manner mixed with oil lubrication methods. In the field of high-speed machining. have air bearings and the development of magnetic bearings and magnetic bearings and air bearings combined constitute the magnetic gas / air mixing spindle.Feed the machine sector, high-speed machining used in the feed drive is usually larger lead, multiple high-speed ball screw and ball array of small-diameter silicon nitride (Si3N4) ceramic ball, to reduce its centrifugal and gyroscopic torque; By using hollow-cooling technology to reduce operating at high speed ball screw as temperature generated by the friction between the lead screw and thermal deformation.In recent years, the use of linear motor-driven high-speed system of up to'' Such feed system has removed the motor from workstations to Slide in the middle of all mechanical transmission links, Implementation of Machine Tool Feed System of zero transmission. Because no linear motor rotating components, from the role of centrifugal force, can greatly increase the feed rate. Linear Motor Another major advantage of the trip is unrestricted. The linear motor is a very time for a continuous machine shop in possession of the bed. Resurfacing of the very meeting where avery early stage movement can go, but the whole system of up to the stiffness without any influence. By using high-speed screw, or linear motor can greatly enhance machine system of up to the rapid response. The maximum acceleration linear motors up to 2-10G (G for the acceleration of gravity), the largest feed rate of up to 60 -200m/min or higher.2002 world-renowned Shanghai Pudong maglev train project of maglev track steel processing, Using the Shenyang Machine Tool Group Holdings Limited McNair friendship company production plants into extra-long high-speed system for large-scale processing centers achieve . The machine feeding system for the linear guide and rack gear drive, the largest table feed rate of 60 m / min, Quick trip of 100 m / min, 2 g acceleration, maximum speed spindle 20000 r / min, the main motor power 80 kW. X-axis distance of up to 30 m, 25 m cutting long maglev track steel error is less than 0.15 mm. Maglev trains for the smooth completion of the project provided a strong guarantee for technologyIn addition, the campaign machine performance will also directly affect the processing efficiency and accuracy of processing. Mold and the free surface of high-speed machining, the main wiring with small cut deep into methods for processing. Machine requirements in the feed rate conditions, should have high-precision positioning functions andhigh-precision interpolation function, especially high-precision arc interpolation. Arc processing is to adopt legislation or thread milling cutter mold or machining parts, the essential processing methods. Cutting Tools Tool Material developmenthigh-speed cutting and technological development of the history, tool material is continuous progress of history. The representation ofhigh-speed cutting tool material is cubic boron nitride (CBN). Face Milling Cutter use of CBN, its cutting speed can be as high as 5000 m / min, mainly for the gray cast iron machining. Polycrystalline diamond (PCD) has been described as a tool of the 21st century tool, It is particularly applicable to the cutting aluminum alloy containing silica material, which is light weight metal materials, high strength, widely used in the automobile, motorcycle engine, electronic devices shell, the base, and so on. At present, the use of polycrystalline diamond cutter Face Milling alloy, 5000m/min the cutting speed has reached a practical level. In addition ceramic tool also applies to gray iron of high-speed machining; Tool Coating : CBN and diamond cutter, despite good high-speed performance, but the cost is relatively high. Using the coating technology to make cutting tool is the low price, with excellent mechanical properties, which can effectively reduce the cost. Now high-speed processing of milling cutter, with most of the wiring between the Ti-A1-N composite technology for the way of multi-processing, If present in the non-ferrous metal or alloy material dry cutting, DLC (Diamond Like Carbon) coating on thecutter was of great concern. It is expected that the market outlook is very significant;Tool clamping system : Tool clamping system to support high-speed cutting is an important technology, Currently the most widely used is a two-faced tool clamping system. Has been formally invested as a commodity market at the same clamping tool system are : HSK, KM, Bigplus. NC5, AHO systems. In the high-speed machining, tool and fixture rotary performance of the balance not only affects the precision machining and tool life. it will also affect the life of machine tools. So, the choice of tool system, it should be a balanced selection of good products.Process ParametersCutting speed of high-speed processing of conventional shear velocity of about 10 times. For every tooth cutter feed rate remained basically unchanged, to guarantee parts machining precision, surface quality and durability of the tool, Feed volume will also be a corresponding increase about 10 times, reaching 60 m / min, Some even as high as 120 m / min. Therefore, high-speed machining is usually preclude the use of high-speed, feed and depth of cut small cutting parameters. Due to the high-speed machining cutting cushion tend to be small, the formation of very thin chip light, Cutting put the heat away quickly; If the wiring using a new thermal stability better tool materials and coatings, Using the dry cutting process for high-speed machining is the ideal technology program. High-speed machining field of applicationFlexible efficient production lineTo adapt to the needs of new models, auto body panel molds andresin-prevention block the forming die. must shorten the production cycle and reduce the cost of production and, therefore, we must make great efforts to promote the production of high-speed die in the process. SAIC affiliated with the company that : Compared to the past, finishing, further precision; the same time, the surface roughness must be met, the bending of precision, this should be subject to appropriate intensive manual processing. Due to the extremely high cutting speed, and the last finishing processes, the processing cycle should be greatly reduced. To play for machining centers and boring and milling machining center category represented by the high-speed machining technology and automatic tool change function of distinctions Potential to improve processing efficiency, the processing of complex parts used to be concentrated as much as possible the wiring process, that is a fixture in achieving multiple processes centralized processing and dilute the traditional cars, milling, boring, Thread processing different cutting the limits of technology, equipment and give full play to the high-speed cutting tool function, NC is currently raising machine efficiency and speed up product development in an effective way. Therefore, the proposed multi-purpose tool of the new requirements call for a tool to complete different partsof the machining processes, ATC reduce the number of ATC to save time, to reduce the quantity and tool inventory, and management to reduce production costs. More commonly used in a multifunctional Tool, milling, boring and milling, drilling milling, drilling-milling thread-range tool. At the same time, mass production line, against the use of technology requires the development of special tools, tool or a smart composite tool, improve processing efficiency and accuracy and reduced investment. In the high-speed cutting conditions, and some special tools can be part of the processing time to the original 1 / 10 below, results are quite remarkable. HSC has a lot of advantages such as : a large number of materials required resection of the workpiece with ultrafine, thin structure of the workpiece, Traditionally, the need to spend very long hours for processing mobile workpiece and the design of rapid change, short product life cycle of the workpiece, able to demonstrate high-speed cutting brought advantages.中文译文高速切削加工的发展及需求高速切削加工是当代先进制造技术的重要组成部分,拥有高效率、高精度及高表面质量等特征。
机械专业外文文献翻译--论药品包装机械的概念设计
中英文翻译原文:Comment on medicines and chemical reagents package machineryconceptual designIn recent years, Carry out GMP (medicines and chemical reagents produces specifications of quality) attestation system because of sustained our country economic situation rise and country to pharmacy industry mandatory. Medicines and chemical reagents package machinery has got quite great progress. The new product increases by gradually. Engineering level has had very big improvement. But be returning very big gaps back to existence compared with international standards. Level being close to 60%'s product cannot to reach upper developed country century eighties. Large-scale advanced equipment is dependent on entrance mainly. Low our country medicines and chemical reagents package machinery engineering level is that the design designing personnel low level from our country enterprise arouses to a great extent.One, our country medicines and chemical reagents package machinery current situation analysesOur country medicines and chemical reagents package machinery still has bigger gap compared with advanced international level. What time is insufficient on domestic medicines and chemical reagents package machinery design under main existence1) Backward domestic mechanical performance medicines and chemical reagents package machinery mostly, accuracy low velocity, is slow, stationarity dispatches package machinery travel process to contain large amount of dyadic complicated intermittence motion. Come to come true mainly from the cam, the connecting rod. But, many design that the personnel is unable to require that the independence designs the parameter calculating cam bar linkage kinematics and dynamics according to job cycle picture and accuracy. Be only the surveying and mapping carrying out a piecemeal that the abroad model machine cam connecting rod part is dismantled down simplely. Bring about actuating mechanism error is very big. That domestic medicines and chemical reagents package machinery runs speed mostly is more general than hanging down according to cutting frequency if the aluminium moulds bubble coverpacker's for 100 one 300 mins, full-automatic medicine box packer dress box speed 50- 200 boxes/ ms in. But, on the international, the advanced aluminium moulds rushing steeping cover packer cutting frequency be able to reach 600 mins. Full-automatic medicine box packer dress box speed is able to reach 600 ~ 800 box/ mins. Not only working speed of domestic medicines and chemical reagents package machinery is slow. And, the partner has bigger noise.2) Is under the control of horizontal backward. Domestic medicines and chemical reagents package machinery controls low, automation of level difference mostly , the malfunction leads height. (Main package machinery finger box dress controls domestic medicines and chemical reagents with drinking wine holding machinery with) adopt PLC to do a scene mostly. But, advanced medicines and chemical reagents package machinery realizes supervisory control abroad mostly from computer system. Under the control of horizontal relatively backward. Great majority domestic medicines and chemical reagents package machinery automation sex is relatively poor. Adopt a single to produce a pattern first commonly. The full-automatic production line is few. Two is that full-automation works cannot to achieve. Require that the manpower feeds in raw material. Hand movement enchases. If in a little paper box packer, Page, paper box all needs medicine board , specifications paper to move charging personally. And require specially-assigned person to pay attention to if specifications, medicine board, paper box already finish using at any time. Happen to avoid bringing about machine racing or bringing about incomplete specifications, medicine board, and medicine box phenomenon. Other, domestic medicines and chemical reagents package mechanic failure rates are higher. Control a component (if the relay, electromagnetic valve, contactor, breaker etc.) etc. are often easy to damage. Halt also to frequently occur the malfunction.3) Functions are unitary, expansion sex is bad. Medicines and chemical reagents package machinery is that the form designs that specifically for specially appointed package. The general specification range inner in regulation is adjustable. But, a lot of our country medicines and chemical reagents package machinery considers insufficiency when designing that. Be not that reforming going a step further sets apart sufficient space. Cause the machinery designing that to be able to only adapt to the form board in several kinds simplicities. Change not adapting to wrapping material or the form board dimension. Fit in with even. The package finished product mass giving birth to a child is neither nice.4) Considers deficiency synthetically. Resource does not fully utilize. Our country medicines and chemical reagents there exists the chaos phenomenon in package machinery design. A lot of machinery designs that the personnel drags to the electric motor moving the synchrony technology, the servo drive technology do not knows. The problem simple electrical equipment available is resolved uses complicated mechanism to come to come true but. Some though the control organ works to come having adopt the synchrony electric motor to wait for a device. But choose block of wood ding-dang. The maximum having brought about resource not only wastes this condition. And make machinery function designing that low.5) Model is inflexible. Model seldom considering machinery time medicines and chemical reagents of our country package machinery design. Many machine molding that the manufacturer produces is not beautiful do not have model even. Give person feeling to rigid, to inflexible, not to have vigor. A few medicine box packers are middle. The nut all assembles screw on the machine outside board. But, the oil cup and flow nipple that a little lubrication uses also can be seen everywhere. Be stained fully with a greasy dirt easy to use machine everywhere time oiling. Impression is rough to person. No beautiful.Two, medicines and chemical reagents package machinery conceptual design contentPeople long-term study passes. Define conceptual design being: "Have been ascertaining the mission queen. Pass abstract-relation. Design the function structure. Explore appropriate effect principle and their combination waiting. Ascertain out basic finding the solution approach. Reach find the solution scheme. This part of the conceptual design designing that the job is called conceptual design is referred to make the queen who designs purpose and now has condition clear. The designer searches for many-sided knowledge. Analysis abstracts the solution on generating dyadic broad frame significance the day after tomorrow. Medicines and chemical reagents package machinery conceptual design demands according to each product life cycle stages. Carrying out the product function creates , the function breaks up as well as the function and son are functional physical design: That conception and systematization carrying out the scheme satisfying the operating principle that the function and structure demand finding the solution and carrying out the operating principle carrier realizing the function structure's design the conceptual design process is that one finds the solution realizing a function's , satisfies the various technologyand various there existing in economic target's , possibility scheme well ultimate for sure synthetically optimum scheme process. The conceptual design effect embodies in the product design early phase stage mainly. Chief architect is based on functional need of product but primitive conception and impulsion sprouting out form the product main body frame. And, it responds to every main module and module including. In order to accomplishing overall layout and the exterior, the first step designs that. And then carry out the optimization appraising a sum. Ascertain the overall design plan. Design that the personnel carries out the chief architect design thought going to designing middle concretely again from every part. Detail designs realization. The conceptual design putting medicines and chemical reagents package machinery into practice demands to design that the personnel reinforces the cognition to medicines and chemical reagents package first. Deepen the connotation understanding medicines and chemical reagents packages. Introduce modern package idea. Be in line with the international conventions actively. Modern package is to ensure the product safety not only. Make product transportation convenient. And be getting up propagate, environmental protection, defends against false. Attractive looks waits for the many-sided effect. Wrap up contents additional information. The medicines and chemical reagents package machinery design personnel should show solicitude for development of package system closely. Go deep into the handicraft studying package. Know demand of development of wrapping material and the person to machinery product very well. Only when such ability designs that out satisfy the high tone machinery product that the consumer demands. Medicines and chemical reagents package machinery conceptual design content has mainly:1) Makes the design mission clear. Be ready for feasibility analysis. The designer designs initial stage working in being in progress. Respond to the feasibility considering a product sufficiently. One aspect is the marketplace thinking. Include the production marketing, product raw material, the fabricating cost thinking: Another aspect is thinking that the product processes. Include thinking now having a working ability, processing handicraft, processing the function and periphery supporting industry. Periphery supporting environment thinking points to the local enterprise working ability mainly processes level, heat treatment handicraft and the infrastructural facilities construction etc.2) Function design. Great majority our country medicines and chemical reagents package machinery is the same kind model copying to abroad. But peculiar nationalconditions because of our country existence. Must carry out appropriate reforming on the product. To satisfy request of our country. But fault blindly copy blindly. The machinery designing that is packed in, irrigates the dress function outside except needing to satisfy a box. We must consider the additional function packing machinery. If in package box should add a counting cup. The medicine spoon waits an utensil down. Be put into use with convenience of customers. In machine, kind of aspect developing can design comparatively advanced machinery. If sterile pack machinery, the package machinery retaining freshness etc.Can develop the corollary equipment selling complete sets of equipment and the post-processing at reduced prices in the medicines and chemical reagents package front.3) Functions decomposition. Medicines and chemical reagents package machinery belongs to the integration of machinery with electronics product. Should consider every function all round time design. Sort Er Yan. The medicines and chemical reagents package machinery function may divide 3 major parts being that organization moves, monitors biography feel, the information processing and controlling a function basically. The function subdivides organization motion according to may not kind with machine , packer may be molding , heat-seal , pressure trace mark, according to cutting 4 big functions if the aluminum moulds bubble cover. But, paper box package machinery may be that the box opens, paper box transfers, breaks tongue , functions such as inserting tongue , flattening and putting a batch number up mark poison board under paper folding, deducing paper feed. Want to consider machinery lubrication, safe functions such as running, packing hygiene of machinery too in the process of design. This demands the technology designing that the personnel considers detecting sufficiently. Brightness, machine, electricity integration technology, computer art. Intersection between the pneumatic technology, the logistics technology connection.4) Organization is designed. Be to realize the predetermined function. We need to use different organization. This needs the part synthesizing each considering a complete machine among one process. Use the product designing that while satisfying the usage request. Structure is simple, pragmatic. Medicines and chemical reagents package machinery organization designs time. Respond to the principle choosing appropriate organization motion and constituting. Think sufficiently to realize what specially appointed motion needs organization. If cam organization. Bar linkage. Cam bar linkage. Respond to the technology wielding separation drive at the same time.Think that the transmission shaft designs a problem (if castellated shaft and ladder axis etc.) and drive are systematic synthetically. Design that process middle should cut down the effect that the uncertainty factor brings about to the full. Messenger organization operation is stable. Design that machinery carries out kinetic methods of analysis answering now and then. With lifting, machinery runs speed and stationarity. Should think that various packing machinery, adjustable, holds the mistake, but expansion, stationarity as well as beautiful-rization besides. Run after machinery is deft but stable. Design process but consult package machinery design of all kinds strong point. Draw other machinery (if plastic machinery, prints machinery) merit at the same time. Design the outside except carrying out organization. Return approach back to the realization should think that every function is other. If vacuum, electrical equipment waits under the control of. To expect that optimum combination is a product's turn.5) System under the control of schemes design. In medicines and chemical reagents package machinery, a very important part is that real time detecting is back-off to every organization. To ensure that equipment operation is smooth. Now many machinery products has selected and used large amount of photo electricity switch being the detecting component. Equipment has such as PC detecting bubble cover system on some machinery and the like system. This need all designs that meticulously. And, the general naval company is an integral whole.Three, concluding remarksThe thought a concept is designed melts to enter medicines and chemical reagents package machinery design being able to fall off designing a fault. Shorten a design cycle. Accelerate the product exploitation. Make the product designing that more rational, have affinity, more suitable man-machine project more. It is also that the main means costing down and improving enterprise competition is short of passive competition aspect backward for improving medicines and chemical reagents package machinery design at the same time. To adapt to the challenge that "queen GMP times" brings about. Design that the personnel must take product conceptual design seriously. Deepen the significance understanding conceptual design's.译文论药品包装机械的概念设计近年来,由于我国经济形势的持续高涨和国家对制药行业强制性推行GMP(药品生产质量规范)认证制度,药品包装机械取得了长足的进步。
机械工程专业外文文献及翻译
机械工程专业外文文献及翻译文献一(外文标题)
摘要:
该文献研究了机械工程领域中的某个具体问题。
通过实验方法和数学模型的分析,作者得出了一些有意义的结论。
本文介绍了作者的研究方法和结果,并讨论了其在机械工程领域的应用前景。
翻译:
(将文献的主要内容用简洁准确的语言翻译成中文)
文献二(外文标题)
摘要:
该文献探讨了机械工程领域中的另一个重要问题。
通过实证分析和理论推导,作者提出了解决方案,并对其进行了验证。
本文阐述了作者的方法和实验结果,并探讨了其在实践中的应用潜力。
翻译:
(将文献的主要内容用简洁准确的语言翻译成中文)
文献三(外文标题)
摘要:
该文献研究了机械工程领域中的另一个新颖课题。
作者通过数
值模拟和实验验证,得出了一些有趣的发现。
本文介绍了作者的研
究过程和结果,并讨论了其对机械工程领域的影响。
翻译:
(将文献的主要内容用简洁准确的语言翻译成中文)
总结
本文档介绍了三篇机械工程专业的外文文献,包括摘要和翻译。
这些文献都对机械工程领域中的不同问题进行了研究,并提出了相
关的解决方案和发现。
希望这些文献能为机械工程专业的学生和研
究人员提供有价值的参考和启发。
机械专业毕业设计英文文献翻译
英文原文Study of Inherent Safety Mine hoist based on modern designmethodsYang Lijie 1, Meng Xiangyun2,Wang Guimei1,Niu Qingna11 Hebei University of Engineering, Handan, Hebei, 056038, ChinaYanglijie255@2 China Telecom Handan Company, Handan, Hebei, 056038, China Abstract—As a modern security design, Inherent Safety means that equipment and facilities is able to contain the inherent fundamental features to prevent accidents. Mine hoist is the most important equipment in the coal production. How to achieve safe, reliable, efficient production has been the focus study at home and abroad. Inherent safety is reflected in hoist design, primarily through the design measures to improve the operation of hoist safety and reliability. In this paper, Inherent Safety theory is applied in the design of mine hoist, to proposed the design method by using the software of PRO/E PLC, Labview etc..Keywords-Mine hoist; Inherent Safety; PRO/E; PLC; LabviewI. INTRODUCTIONIn coal production, mine hoist is the equipment to carry coal, gangue, materials, workers and equipments along the rockshaft, the only way linked underground and aboveground, known as mine throat. Mine hoist is a large-scale reciprocating machinery which has the feature of own big inertia, load changes, running speed, and wide range et al.. The advantages and disadvantages of its operating performance, not only directly affect the normal production and coal production efficiency, but also relate to equipment and personal safety. In recent years, mine hoist failures and accidents have happened at home and abroad which have paid a heavy price to coal companies. Therefore, the production technology and safety of mine hoist are higher, and its mechanical manufacturing technology and electrical control technology has been an important research area to the international machine building industry and the electric control industry.Inherent Safety means that equipment and facilities is able to contain the inherent fundamental features to prevent accidents. Inherent Safety lies in design, through continuous improvement, to prevent accidents due to the equipment itself failures. Inherent safety is reflected in hoist design, primarily through the design measures to improve the operation of hoist safety and reliability. In this paper, Inherent Safety theory is applied in the design of mine hoist, to proposed the inherent safety design method by use the software of PRO/E PLC, Labview etc..II. INHERENT SAFETY THEORYThe term of inherent safety originates the development of world space technology in the 1950s. The concept is widely accepted closely linked with scientific technological progress and human understanding of safety culture. The concept of inherent safety produced after the World War II which became major safety concept in many industrialized countries since the mid 20th century.Inherent safety design as the basic method of hazard control, by selecting safe materials, process routes, mechanical equipment, devices, to eliminate or control hazards source rather than relying on "additional" security measures or management measures to control them. As inherent safety design, firstly analyze and identify hazards that may occur in system, and then choose the best methods to eliminate, control hazards, which reflected in project design.Ⅲ. THE DESIGN OF INHERENT SAFETY MINE HOISTMine hoist mainly includs the working device, control system, transmission system and drag, protection systems and other components. To the inherent safety mine hoist design, mainly the mechanical system, control system and monitor system is the major part to considered.A.In-depth investigations to find malfunctionThe concept of inherent safety is required safety all the time in the product design process. That is, the equipment has little malfunction as much as possible during the operation and has long normal operation cycle length. How can design inherent safety equipment, the most important thing is understanding enough to the equipment, especially in work. After in-depth research, fully understanding the situation, try the best to reduce or eliminate the fault in the design. After in-depth understanding of research, design product.B. Mechanical SystemThe traditional method of product has long design cycle, high costs. However, the virtual prototype technology has the advantage in saving the design cost, shortening the design circle, by using the method of modeling, simulation first and then builds the physical prototype. Therefore, the virtual design is the developing trends of mechanical design. In mechanical system design, the application of virtual prototype is used to design mine hoist, not only speeded up the design process, also simulated a variety of conditions to the virtual prototype to discover design faults, to improve the design, to improve mine hoist performance.Mine hoist mechanical system is composed of spindle, roller, reducer, motor, brakes and other components. In its design, virtual design software PRO / E is applied to establish hoist prototype, application of simulation software ADAMS is used to simulate and optimize the design. Specific process shown in Figure 1:Figure 1. Mechanical system designC. Control system designMine hoist control system includes start, run, brake, etc., the requirements in control system are:In normal hoist operation, participation in hoist speed control, brake the hoist when reaching the destination, known as the service braking;In case of emergency, can quickly slow down as required, brake hoist, to prevent the expansion of the accident, that is the safety braking; Participate in the hoist speed control when decelerati; To double-roller hoist, should brake the moving roller and fix roller respectively when regulating rope length, replacement level and changing rope, so that, moving roller would not move when spindle rotates with the fixed roller.Most of mine hoists in China (more than 70%) use the traditional electric control system (tkd-a as the representative). Tkd control system is composed of relay logic circuits, large air contactors, tachometer generator etc., which is a touch control system. After years of development, tkd-a series of electric control system has formed its own characteristics, but its shortcomings are obvious. Its electrical circuit is too complicated, multi-line, causing hoist parking and accidents occurred due to electrical fault. With the computer and digital technology, to form a digital hoist control systemof PLC has become possible. PLC control system has high control precision, parameter stability, simple hardware structure, self-diagnostic capability and communication networking function.Mine hoist control system based on PLC technology structure shown in Figure 2, mainly including the following components: the main plc control circuits, hoist route detection and display circuits, speed detection, and signal circuits. The PLC of the main control circuits uses Mitsubishi FX2N series in Japan which more domestic applications.Figure 2 PLC electric control systemD. Monitoring system designTo ensure safe operation of the hoist, except for selecting the reasonable operation design parameters, the use of advanced control system, should also monitor the technological parameters on regular, conscientiously do performance test work to master the hoist performance, discover the defects in time, eliminate hidden danger,avoid unnecessary losses. In addition, the hoist operation state can be improved to work in the best conditions based on test data. Therefore, the hoist could work safely, reliably, have high efficiency, and extend its work life.Virtual instrument technology is computer-based instrumentation and measurement technology, is loaded some software and hardware on the computer with similar appearance and performance of the actual independent instrument. The user operating the computer, like manipulating a especially conventional electronic devices designed theirs. The essence of virtual instrument technology is that hardware softwarized technology, take full advantage of the latest computer technology to implement and expand the functions of traditional instruments.LabVIEW (laboratory virtual instrument engineering workbench) is a graphical programming and development environment, also known as "G" language. It is widely used by industry, academia and research laboratories, accepted as the standard data acquisition and instrument control software. LabVIEW not only provides and complies with all the functions of hardware and data acquisition cards communications of GPIB, VXI, RS-232 and RS-485 protocol, and built-in library functions support for TCP / IP, ActiveX and other software standards. The software for scientists and engineers is a programming language, it provides a simple, intuitive graphical programming mode, saves a lot of development time, has complete function, best embodied style of virtual instrument.In response to these circumstances, developed a mine hoist Integrate Performance Monitoring System based on virtual instrument LabVIEW-based. Show in Figure 3. With signal conditioning and data acquisition card to receive signals from sensors, then sent the received signal to the virtual instrument software platform, enables the following features:(1)show speed, acceleration, braking time, displacement, oil pressure, delay time and other relevant parameters in digital, and display speed, acceleration, traction, displacement and hydraulic curves.(2)Dynamically monitor the hydraulic oil pressure and oil pump running station, based on these parameters to avoid important braking system failure.(3)Test brake air travel time, relay delay time and other time parameters.(4)inquiry to the measured curve and hoist parameters; print a test report.Figure 3. Diagram of test systemThe monitoring system has characteristics such as compact, light weight, high precision, testing convenient and flexible, feature-rich software etc.. the system can not only display automatically test results, but also finish multiple functions, for example , data transmission, analysis, processing, storage and report printing. The system is high precision, can easily monitor the hoist operation state, to ensure the reliability of hoist operation.Ⅳ. CONCLUSIONSIn this paper, used virtual design software to design the hoist mechanical system, PLC to design control system, applied virtual instrument software-LABVIEW to design monitor system. Therefore, the mine hoist designed has good mechanical properties and safe operation, monitoring easy.REFERENCES[1] Weng qishu. The inherent safety and checks of cabin[J]. navigationTechnology 2006 (3):50-52. (in Chinese)[2] Li jangbo. Study of Test System of Composite Characteristic of Devices Based onVirtual instrument[D]. A Dissertation Submitted to Hebei University ofEngineering For the Academic Degree of Master of Engineering, 2007. (inChinese)[3] Wang chengqin, Li wei , Meng baoxing et al... Random vibration testing system ofhoisting gear based on virtual instrument. Coal mine machinery, 2008(4) :118-120.(in Chinese)[4] Chen baozhi Wu min. concept and practices of inherent safety[J]. Journal ofSafety Science and Technology,2008(6):79-83. (in Chinese)[5] Xu chenyi, Wu yongdong, Huanghe et al.. A PLC-based mine hoist control systemdesign [J]. LC&FA, 2008(10):52-56 (in Chinese)中文译文基于现代设计方法的矿井提升机内在安全性的研究Yang Lijie 1, Meng Xiangyun2,Wang Guimei1,Niu Qingna11河北工程大学,河北邯郸,056038,中国Yanglijie255@2中国电信邯郸分公司,河北邯郸,056038,中国摘要:作为一个现代的安全设计,内在的安全性意味着设备和设施能够包含防止事故发生的固有基本特征。
机械专业英语短文带翻译
机械工程师的关键责任之一是设计与分析机械系统。这涉及使用计算机辅助设计(CAD)软件创建系统的详细三维模型,并在不同条件下模拟其性能。通过分析作用于系统组件的力、应力和振动,机械工程师可以优化设计,确保安全、可靠和高效。
Case Study: Designing an Automotive Suspension System
案例研究:汽车悬挂系统设计
例如,让我们考虑一下汽车悬挂系统的设计。悬挂系统负责在保持车辆稳定控制的同时提供平稳的行驶。机械工程师使用CAD软件设计悬挂系统的各个组件,例如弹簧、减振器和控制臂。
在完成初始设计后,工程师将使用有限元分析(FEA)软件对系统进行分析。这样可以模拟系统在不同的道路条件下(如坑洼或减速带)的行为。通过分析组件中的应力和位移,工程师可以确定潜在的设计问题,并进行必要的修改,以改善悬挂系统的性能和安全性。
For example, let's consider the design of an automotive suspension system. A suspension system is responsible for providing a smooth ride while maintaining the stability and control of the vehicle. A mechanical engineer would use CAD software to design the various components of the suspension system, such as the springs, dampers, and control arms.
After the initial design is complete, the engineer would then analyze the system using finite element analysis (FEA) software. This allows them to simulate the behavior of the system under different road conditions, such as potholes or speed bumps. By analyzing the stresses and displacements in the components, the engineer can identify potential design issues and make necessary modifications to improve the performance and safety of the suspension system.
机械工程及自动化专业外文翻译--机械工程
外文原文:Mechanical engineering1.The porfile of mechanical engineeringEngingeering is a branch of mechanical engineerig,it studies mechanical and power generation especially power and movement.2.The history of mechanical engineering18th century later periods,the steam engine invention has provided a main power fountainhead for the industrial revolution,enormously impelled each kind of mechznical biting.Thus,an important branch of a new Engineering –separated from the civil engineering tools and machines on the branch-developed together with Birmingham and the establishment of the Associantion of Mechanical Engineers in 1847 had been officially recognized.The mechanical engineering already mainly used in by trial and error method mechanic application technological development into professional engineer the scientific method of which in the research,the design and the realm of production used .From the most broad perspective,the demend continuously to enhance the efficienceyof mechanical engineers improve the quality of work,and asked him to accept the history of the high degree ofeducation and training.Machine operation to stress not only economic but also infrastructure costs to an absolute minimun.3.The field of mechanical engineeringThe commodity machinery development in the develop country,in the high level material life very great degree is decided each kind of which can realize in the mechanical engineering.Mechanical engineers unceasingly will invent the machine next life to produce the commodity,unceasingly will develop the accuracy and the complexity more and more high machine tools produces the machine.The main clues of the mechanical development is:In order to enhance the excellent in quality and reasonable in price produce to increase the precision as well as to reduce the production cost.This three requirements promoted the complex control system development.The most successful machine manufacture is its machine and the control system close fusion,whether such control system is essentially mechanical or electronic.The modernized car engin production transmission line(conveyer belt)is a series of complex productions craft mechanization very good example.The people are in the process of development in order to enable further automation of the production machinery ,the use of a computer to store and handle largevolumes of data,the data is a multifunctional machine tools necessary for the production of spare parts.One of the objectives is to fully automated production workshop,three rotation,but only one officer per day to operate.The development of production for mechanical machinery must have adequate power supply.Steam engine first provided the heat to generate power using practical methods in the old human,wind and hydropower,an increase of engin .New mechanical engineering industry is one of the challenges faced by the initial increase thermal effciency and power,which is as big steam turbine and the development of joint steam boilers basically achieved.20th century,turbine generators to provide impetus has been sustained and rapid growth,while thermal efficiency is steady growth,and large power plants per kW capital consumption is also declining.Finally,mechanical engineers have nuclear energy.This requires the application of nuclear energy particularly high reliability and security, which requires solving many new rge power plants and the nuclear power plant control systems have become highly complex electroonics,fluid,electricity,water and mechanical parts networks All in all areas related to the mechanical engineers.Small internal combustion engine,both to the type(petrol and diesel machines)or rotary-type(gas turbines and Mong Kerr machine),as well as their broad application in the field of transport should also due to mechanical enginerrs.Throughout the transport,both in the air and space,or in the terrestrial and marine,mechanial engineers created a variety of equipment and power devices to their increasing cooperation with electrical engineers,especially in the development of appropration control systems.Mechanical engineers in the development of military weapons technology and civil war ,needs a similar,though its purpose is to enhance rather than destroy their productivity.However.War needs a lot of resources to make the area of techonlogy,many have a far-reaching development in peacetime efficiency.Jet aircraft and nuclear reactors are well known examples.The Biological engineering,mechanical engineering biotechnology is a relatively new and different areas,it provides for the replacement of the machine or increase the body functions as well as for medical equipment.Artficial limbs have been developed and have such a strong movement and touch response function of the human body.In the development of artificial organ transplant is rapid,complex cardiac machines and similar equipment to enable increasingly complexsurgery,and injuries and ill patients life functions can be sustained.Some enviromental control mechanical engineers through the initial efforts to drainage or irrigation pumping to the land and to mine and ventilation to control the human environment.Modern refrigeration and air-conditioning plant commonaly used reverse heat engine,where the heat from the engine from cold places to more external heat.Many mechanical engineering products,as well as other leading technology development city have side effects on the environment,producing noise,water and air pollution caused,destroyed land and landscape.Improve productivity and diver too fast in the commodity,that the renewable natural forces keep pace.For mechanical engineers and others,environmental control is rapidly developing area,which includes a possible development and production of small quantities of pollutants machine sequnce,and the development of new equipment and teachnology has been to reduce and eliminate pollution.4.The role of mechanical engineeringThere are four generic mechanical engineers in common to the above all domains function.The 1st function is the understanding and the research mechanical sciencefoundation.It includes the power and movement of the relationship dynamics For example,in the vibration and movement of the relationship;Automatic control;Study of the various forms of heart,energy,power relations between the thermodynamic;Fluidflows; Heat transfer; Lubricant;And material properties.The 2nd function will be conducts the research,the desing and the development,this function in turn attempts to carry on the essential change to satisfy current and the future needs.This not only calls for a clear understanding of mechanical science,and have to break down into basic elements of a complex system capacity.But also the need for synthetic and innovative inventions.The 3rd function is produces the product and the power,include plan,operation and maintenance.Its goal lies in the maintenance either enhances the enterprise or the organization longer-tern and survivabilaty prestige at the same time,produces the greatest value by the least investments and the consumption.The 4th function is mechanical engineer’s coordinated function,including the management,the consultation,as well as carries on the market marking in certain situation.In all these function,one kind unceasingly to use thescience for a long time the method,but is not traditional or the intuition method tendency,this is a mechanical engineering skill aspect which unceasingly grows.These new rationalization means typical names include:The operations research,the engineering economics,the logical law problem analysis(is called PABLA) However,creativity is not rationalization.As in other areas,in mechanical engineering,to take unexpected and important way to bring about a new capacity,still has a personal,marked characteristice.5.The design of mechanical engineeringThe design of mechanical is the design has the mechanical property the thing or the system,such as:the instrument and the measuring appliance in very many situations,the machine design must use the knowledge of discipline the and so on mathematics,materials science and mechanics.Mechanical engineering desgin includeing all mechanical desgin,but it was a study,because it also includes all the branches of mechsnical engineering,such as thermodynamics all hydrodynamics in the basic disciplines needed,in the mechanical engineering design of the initial stude or mechanical design.Design stages.The entire desgin process from start to finish,in the process,a demand that is designed forit and decided to do the start.After a lot of repetition,the final meet this demand by the end of the design procees and the plan.Design considerations.Sometimes in a system is to decide which parts needs intensity parts of geometric shapesand size an important factor in this context that we must consider that the intensity is an important factor in the design.When we use expression design considerations,we design parts that may affect the entire system design features.In the circumstances specified in the design,usually for a series of such functions must be taken into account.Howeever,to correct purposes,we should recognize that,in many cases the design of important design considerations are not calculated or test can determine the components or systems.Especially students,wheen in need to make important decisions in the design and conduct of any operation that can not be the case,they are often confused.These are not special,they occur every day,imagine,for example,a medical laboratory in the mechanical design,from marketing perspective,people have high expectations from the strength and relevance of impression.Thick,and heavy parts installed together:to produce a solid impression machines.And sometimes machinery and spare parts from the design style is the point and not theother point of view.Our purpose is to make those you do not be misled to believe that every design decision will need reasonable mathematical methods.Manufacturing refers to the raw meterials into finished products in the enterprise.Create three distinct phases.They are:input,processing exprot.The first phase includes the production of all products in line with market needs essential.First there must be the demand for the product,the necessary materials,while also needs such as energy,time,human knowledge and technology resourcess .Finall,the need for funds to obtain all the other resources. Lose one stage after the second phase of the resources of the processes to be distributed.Processing of raw materials into finished products of these processes.To complete the design,based on the design,and then develop plans.Plan implemented through various production processes.Management of resources and processes to ensure efficiency and productivity.For example,we must carefully manage resources to ensure proper use of funds.Finally,people are talking about the product market was cast.Stage is the final stage of exporting finished or stage.Once finished just purchased,it must be delivered to the users.According to productperformance,installation and may have to conduct further debugging in addition,some products,especially those very complex products User training is necessary.6.The processes of materials and maunfacturingHere said engineering materials into two main categories:metals and non-ferrous,high-performance alloys and power metals.Non-metallic futher divided into plastice,synthetic rubber,composite materials and ceramics.It said the production proccess is divided into several major process,includingshape,forging,casting/ founding,heat treatment,fixed/connections ,measurement/ quality control and materal cutting.These processes can be further divide into each other’s craft.Various stages of the development of the manufacturing industry Over the years,the manufacturing process has four distinct stages of development, despite the overlap.These stages are:The first phase is artisanal,the second Phase is mechanization.The third phase is automation the forth Phase is integrated.When mankind initial processing of raw materials into finished products will be,they use manual processes.Each with their hands and what are the tools manuslly produced.This is totally integrated production take shape.A person needsindentification,collection materials,the design of a product to meet that demand,the production of such products and use it.From beginning to end,everything is focused on doing the work of the human ter in the industrial revolution introduced mechanized production process,people began to use machines to complete the work accomplished previously manual. This led to the specialization.Specialization in turn reduce the manufacture of integrated factors.In this stage of development,manufacturing workers can see their production as a whole represent a specific piece of the part of the production process.One can not say that their work is how to cope with the entire production process,or how they were loaded onto a production of parts finished.Development of manufacting processes is the next phase of the selection process automation.This is a computer-controlled machinery and processes.At this stage,automation island began to emerge in the workshop lane.Each island represents a clear production process or a group of processes.Although these automated isolated island within the island did raise the productivity of indivdual processes,but the overall productivity are often not change.This is because the island is not caught in other automated production process middle,but not synchronous withthem .The ultimate result is the efficient working fast parked through automated processes,but is part of the stagnation in wages down,causing bottlenecks.To better understand this problem,you can imagine the traffic in the peak driving a red light from the red Service Department to the next scene. Occasionally you will find a lot less cars,more than being slow-moving vehicles,but the results can be found by the next red light Brance.In short you real effect was to accelerate the speed of a red Department obstruction offset.If you and other drivers can change your speed and red light simultaneously.Will advance faster.Then,all cars will be consistent,sommth operation,the final everyone forward faster.In the workshop where the demand for stable synchronization of streamlined production,and promoted integration of manufacturing development.This is a still evolving technology.Fully integrated in the circumstances,is a computer-controllrd machinery and processing.integrated is completed through computer.For example in the preceding paragraph simulation problems,the computer will allow all road vehicles compatible with the change in red.So that everyone can steady traffic.Scientific analysis of movement,timing and mechanics of the disciplines is that it is composed of two pater:statics anddynamics.Statics analyzed static system that is in the system,the time is not taken into account,research and analysis over time and dynamics of the system change.Dynameics from the two componets.Euler in 1775 will be the first time two different branches: Rigid body movement studies can conveniently divided into two parts:geometric and mechanics.The first part is without taking into account the reasons for the downward movement study rigid body from a designated location to another point of the movement,and must use the formula to reflect the actual,the formula would determine the rigid body every point position. Therefore,this study only on the geometry and,more specifically,on the entities from excision.Obviously,the first part of the school and was part of a mechanical separation from the principles of dynamics to study movement,which is more than the two parts together into a lot easier.Dynamics of the two parts are subsequently divided into two separate disciplines,kinematic and dynamics,a study of movement and the movement strength.Therefore,the primary issue is the design of mechanical systems understand its kinematic.Kinematic studies movement,rather than a study of its impact.In a more precise kinematic studies position,displacement,rotation,speed,velocity and acceleration of disciplines,for esample,or planets orbiting research campaing is a paradigm.In the above quotation content should be pay attention that the content of the Euler dynamics into kinematic and rigid body dynamics is based on the assumption that they are based on research.In this very important basis to allow for the treatment of two separate disciplines.For soft body,soft body shape and even their own soft objects in the campaign depends on the role of power in their possession.In such cases,should also study the power and movement,and therefore to a large extent the analysis of the increased complexity.Fortunately, despite the real machine parts may be involved are more or less the design of machines,usually with heavy material designed to bend down to the lowest parts.Therefore,when the kinematic analysis of the performance of machines,it is often assumed that bend is negligible,spare parts are hard,but when the load is known,in the end analysis engine,re-engineering parts to confirm this assnmption.中文译文:机械工程1.机械工程简介机械工程是工程学的一个分支,它研究机械和动力的产,尤其是力和动力。
【机械专业文献翻译】机械设计理论
Machine design theoryThe machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question.Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge.If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of productMust regard as the machine design is the machine design personnelcarries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wronglyA good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority.Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method.In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnel''s basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process.Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagramand the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem:(1) designs whether this product truly does need for the people? Whether there is competitive ability(2) does this product compare with other companies'' existing similar products?(3) produces this kind of product is whether economical?(4) product service is whether convenient?(5) product whether there is sale? Whether may gain?Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manufacture to the finally design proposalUsually, can have some problem in the manufacture process. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed thedesign is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently, seeks these better method.Recent year, the engineerig material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, worker''s health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes from domestic and international competition, to product service maintenance convenience request enhancement and customer''s aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profound influence. In addition, the material and between the material processing interdependence is already known by the people clearly. Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly carefully to choose, the determination and the use material.Makes any product the first step of work all is designs. Designsusually may divide into several explicit stages: (a) preliminary design; (b) functional design; (c) production design. In the preliminary design stage, the designer emphatically considered the product should have function. Usually must conceive and consider several plans, then decided this kind of thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performance to conform to the request material to be possible to supply the choice; If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage, needs to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which useswith its production in be same, and uses the similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then this kind of prototype does not have the great value. Project engineer is best can completely complete the material in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because, is carries on in the production design stage material replacement by other people, these people are inferior to project engineer to the product all functions understanding. In the production design stage, is should completely determine with the material related main question the material, causes them to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply.In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The experience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situations. Started after the productionmanufacture to appear has been possible to supply the use the new material is replaces the material the most common reason. Certainly, these new materials possibly reduce the cost, the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The majority of products expiration and the product accident caused by negligence case is because in selects the new material to take in front of substitution material, not truly understood their long-term operational performance causes.The product responsibility lawsuit forces designs the personnel and the company when the choice material, uses the best procedure. In the material process, five most common questions are: (a) did not understand or cannot use about the material application aspect most newly the best information paper; (b) has not been able to foresee and to consider the dusk year possible reasonable use (for example to have the possibility, designs the personnel also to be supposed further to forecast and the consideration because product application method not when creates consequence.In recent years many products responsibilities lawsuit case, because wrongly uses the plaintiff which the product receives the injury to accuse produces the factory, and wins the decision); (c) uses the material data not entire perhaps some data are indefinite, works as its long-term performancedata is the like this time in particular; (d) the quality control method is not suitable and not after the confirmation; (e) the personnel which completely is not competent for the post by some chooses the material.Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity.May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding.机械设计理论机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科学。
机械专业毕业设计外文翻译1
本科毕业设计(本科毕业论文)外文文献及译文文献、资料题目:High-rise Tower Crane designed文献、资料来源:期刊(著作、网络等)文献、资料发表(出版)日期:2000.3.25院(部):机电工程学院专业:机电工程及自动化High-rise Tower Crane designed under Turbulent Winds At present, construction of tower cranes is an important transport operations lifting equipment, tower crane accident the people's livelihood, major hazards, and is currently a large number of tower crane drivers although there are job permits, due to the lack of means to monitor and review the actual work of a serious violation . Strengthen the inspection and assessment is very important. Tower crane tipping the cause of the accident can be divided into two aspects: on the one hand, as a result of the management of tower cranes in place, illegal operation, illegal overloading inclined cable-stayed suspended widespread phenomenon; Second, because of the tower crane safety can not be found in time For example,Took place in the tower crane foundation tilt, micro-cracks appear critical weld, bolts loosening the case of failure to make timely inspection, maintenance, resulting in the continued use of tower cranes in the process of further deterioration of the potential defect, eventually leading to the tower crane tipping. The current limit of tower crane and the black box and can not be found to connect slewing tower and high-strength bolts loosening tightened after the phenomenon is not timely, not tower verticality of the axis line of the lateral-line real-time measurement, do not have to fight the anti-rotation vehicles, lifting bodies plummeted Meng Fang, hook hoists inclined cable is a timely reminder and record of the function, the wind can not be contained in the state of suspended operation to prevent tipping on the necessary tips on site there is a general phenomenon of the overloaded overturning of the whole security risks can not be accurately given a reminder and so on, all of which the lease on the tower crane, use, management problems,Through the use of tower crane anti-tipping monitor to be resolved. Tower crane anti-tipping Monitor is a new high-tech security monitoring equipment, and its principle for the use of machine vision technology and image processing technology to achieve the measurement of the tilt tower, tower crane on the work of state or non-working state of a variety of reasons angle of the tower caused by the critical state to achieve the alarm, prompt drivers to stop illegal operation, a computer chip at the same time on the work of the state of tower crane be recorded. Tower crane at least 1 day overload condition occurs, a maximum number of days to reach 23 overloading, the driver to operate the process of playing the anti-car, stop hanging urgency, such as cable-stayed suspended oblique phenomenon often, after verification and education, to avoid the possible occurrence of fatal accidents. Wind conditions in the anti-tipping is particularly important, tower cranes sometimes connected with the pin hole and pin do not meet design requirements, to connect high-strength bolts are not loose in time after the tightening of the phenomenon, through timely maintenance in time after the tightening of the phenomenon, through timely maintenance and remedial measures to ensure that the safe and reliable construction progress. Reduced lateral line tower vertical axis measuring the number of degrees,Observation tower angle driver to go to work and organize the data once a month to ensure that the lateral body axis vertical line to meet the requirements, do not have to every time and professionals must be completed by Theodolite tower vertical axismeasuring the lateral line, simplified the management link. Data logging function to ensure that responsibility for the accident that the scientific nature to improve the management of data records for the tower crane tower crane life prediction and diagnosis of steel structures intact state data provides a basis for scientific management and proactive prevention of possible accidents, the most important thing is, if the joint use of the black box can be easily and realistically meet the current provisions of the country's related industries. Tower crane safety management at the scene of great importance occurred in the construction process should be to repair damaged steel, usually have to do a good job in the steel tower crane maintenance work and found that damage to steel structures, we must rule out potential causes of accidents, to ensure safety in production carried out smoothly. Tower crane in the building construction has become essential to the construction of mechanical equipment, tower crane at the construction site in the management of safety in production is extremely important. A long time, people in the maintenance of tower crane, only to drive attention to the conservation and electrical equipment at the expense of inspection and repair of steel structures, to bring all kinds of construction accidents.Conclusion: The tower crane anti-tipping trial monitor to eliminate potential causes of accidents to provide accurate and timely information, the tower crane to ensure the smooth development of the leasing business, the decision is correct, and should further strengthen and standardize the use of the environment (including new staff training and development of data processing system, etc.).The first construction cranes were probably invented by the Ancient Greeks and were powered by men or beasts of burden, such as donkeys. These cranes were used for the construction of tall buildings. Larger cranes were later developed, employing the use of human treadwheels, permitting the lifting of heavier weights. In the High Middle Ages, harbour cranes were introduced to load and unload ships and assist with their construction – some were built into stone towers for extra strength and stability. The earliest cranes were constructed from wood, but cast iron and steel took over with the coming of the Industrial Revolution.For many centuries, power was supplied by the physical exertion of men or animals, although hoists in watermills and windmills could be driven by the harnessed natural power. The first 'mechanical' power was provided by steam engines, the earliest steam crane being introduced in the 18th or 19th century, with many remaining in use well into the late 20th century. Modern cranes usually use internal combustion engines or electric motors and hydraulic systems to provide a much greater lifting capability than was previously possible, although manual cranes are still utilised where the provision of power would be uneconomic.Cranes exist in an enormous variety of forms – each tailored to a specific use. Sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes,used for constructing high buildings, and the largest floating cranes, used to build oil rigs and salvage sunken ships.This article also covers lifting machines that do not strictly fit the above definition of a crane, but are generally known as cranes, such as stacker cranes and loader cranes.The crane for lifting heavy loads was invented by the Ancient Greeks in the late 6th century BC. The archaeological record shows that no later than c.515 BC distinctive cuttings for both lifting tongs and lewis irons begin to appear on stone blocks of Greek temples. Since these holes point at the use of a lifting device, and since they are to be found either above the center of gravity of the block, or in pairs equidistant from a point over the center of gravity, they are regarded by archaeologists as the positive evidence required for the existence of the crane.The introduction of the winch and pulley hoist soon lead to a widespread replacement of ramps as the main means of vertical motion. For the next two hundred years, Greek building sites witnessed a sharp drop in the weights handled, as the new lifting technique made the use of several smaller stones more practical than of fewer larger ones. In contrast to the archaic period with its tendency to ever-increasing block sizes, Greek temples of the classical age like the Parthenon invariably featured stone blocks weighing less than 15-20 tons. Also, the practice of erecting large monolithic columns was practically abandoned in favour of using several column drums.Although the exact circumstances of the shift from the ramp to the crane technology remain unclear, it has been argued that the volatile social and political conditions of Greece were more suitable to the employment of small, professional construction teams than of large bodies of unskilled labour, making the crane more preferable to the Greek polis than the more labour-intensive ramp which had been the norm in the autocratic societies of Egypt or Assyria.The first unequivocal literary evidence for the existence of the compound pulley system appears in the Mechanical Problems (Mech. 18, 853a32-853b13) attributed to Aristotle (384-322 BC), but perhaps composed at a slightly later date. Around the same time, block sizes at Greek temples began to match their archaic predecessors again, indicating that the more sophisticated compound pulley must have found its way to Greek construction sites by then.During the High Middle Ages, the treadwheel crane was reintroduced on a large scale after the technology had fallen into disuse in western Europe with the demise of the Western Roman Empire. The earliest reference to a treadwheel (magna rota) reappears in archival literature in France about 1225, followed by an illuminated depiction in a manuscript of probably also French origin dating to 1240. In navigation, the earliest uses of harbor cranes are documented for Utrecht in 1244, Antwerp in 1263, Brugge in 1288 and Hamburg in 1291, while in England the treadwheel is not recorded before 1331.Generally, vertical transport could be done more safely and inexpensively by cranes than by customary methods. Typical areas of application were harbors, mines, and, in particular, building sites where the treadwheel crane played a pivotal role in the construction of the lofty Gothic cathedrals. Nevertheless, both archival and pictorial sources of the time suggest that newly introduced machines like treadwheels or wheelbarrows did not completely replace more labor-intensive methods like ladders, hods and handbarrows. Rather, old and new machinery continued to coexist on medieval construction sites and harbors.Apart from treadwheels, medieval depictions also show cranes to be powered manually by windlasses with radiating spokes, cranks and by the 15th century also by windlasses shaped like a ship's wheel. To smooth out irregularities of impulse and get over 'dead-spots' in the lifting process flywheels are known to be in use as early as 1123.The exact process by which the treadwheel crane was reintroduced is not recorded, although its return to construction sites has undoubtedly to be viewed in close connection with the simultaneous rise of Gothic architecture. The reappearance of the treadwheel crane may have resulted from a technological development of the windlass from which the treadwheel structurally and mechanically evolved. Alternatively, the medieval treadwheel may represent a deliberate reinvention of its Roman counterpart drawn from Vitruvius' De architectura which was available in many monastic libraries. Its reintroduction may have been inspired, as well, by the observation of the labor-saving qualities of the waterwheel with which early treadwheels shared many structural similarities.In contrast to modern cranes, medieval cranes and hoists - much like their counterparts in Greece and Rome - were primarily capable of a vertical lift, and not used to move loads for a considerable distance horizontally as well. Accordingly, lifting work was organized at the workplace in a different way than today. In building construction, for example, it is assumed that the crane lifted the stone blocks either from the bottom directly into place, or from a place opposite the centre of the wall from where it could deliver the blocks for two teams working at each end of the wall. Additionally, the crane master who usually gave orders at the treadwheel workers from outside the crane was able to manipulate the movement laterally by a small rope attached to the load. Slewing cranes which allowed a rotation of the load and were thus particularly suited for dockside work appeared as early as 1340. While ashlar blocks were directly lifted by sling, lewis or devil's clamp (German Teufelskralle), other objects were placed before in containers like pallets, baskets, wooden boxes or barrels.It is noteworthy that medieval cranes rarely featured ratchets or brakes to forestall the load from running backward.[25] This curious absence is explained by the high friction force exercised by medieval treadwheels which normally prevented the wheel from accelerating beyond control.目前,塔式起重机是建筑工程进行起重运输作业的重要设备,塔机事故关系国计民生、危害重大,而目前众多的塔机司机虽然有上岗证,由于缺少监督和复核手段,实际工作中违规严重。
机械专业外文翻译中英文翻译外文文献翻译
英文资料High-speed millingHigh-speed machining is an advanced manufacturing technology, different from the traditional processing methods. The spindle speed, cutting feed rate, cutting a small amount of units within the time of removal of material has increased three to six times. With high efficiency, high precision and high quality surface as the basic characteristics of the automobile industry, aerospace, mold manufacturing and instrumentation industry, such as access to a wide range of applications, has made significant economic benefits, is the contemporary importance of advanced manufacturing technology. For a long time, people die on the processing has been using a grinding or milling EDM (EDM) processing, grinding, polishing methods. Although the high hardness of the EDM machine parts, but the lower the productivity of its application is limited. With the development of high-speed processing technology, used to replace high-speed cutting, grinding and polishing process to die processing has become possible. To shorten the processing cycle, processing and reliable quality assurance, lower processing costs.1 One of the advantages of high-speed machiningHigh-speed machining as a die-efficient manufacturing, high-quality, low power consumption in an advanced manufacturing technology. In conventional machining in a series of problems has plagued by high-speed machining of the application have been resolved.1.1 Increase productivityHigh-speed cutting of the spindle speed, feed rate compared withtraditional machining, in the nature of the leap, the metal removal rate increased 30 percent to 40 percent, cutting force reduced by 30 percent, the cutting tool life increased by 70% . Hardened parts can be processed, a fixture in many parts to be completed rough, semi-finishing and fine, and all other processes, the complex can reach parts of the surface quality requirements, thus increasing the processing productivity and competitiveness of products in the market.1.2 Improve processing accuracy and surface qualityHigh-speed machines generally have high rigidity and precision, and other characteristics, processing, cutting the depth of small, fast and feed, cutting force low, the workpiece to reduce heat distortion, and high precision machining, surface roughness small. Milling will be no high-speed processing and milling marks the surface so that the parts greatly enhance the quality of the surface. Processing Aluminum when up Ra0.40.6um, pieces of steel processing at up to Ra0.2 ~ 0.4um.1.3 Cutting reduce the heatBecause the main axis milling machine high-speed rotation, cutting a shallow cutting, and feed very quickly, and the blade length of the workpiece contacts and contact time is very short, a decrease of blades and parts of the heat conduction. High-speed cutting by dry milling or oil cooked up absolute (mist) lubrication system, to avoid the traditional processing tool in contact with the workpiece and a lot of shortcomings to ensure that the tool is not high temperature under the conditions of work, extended tool life.1.4 This is conducive to processing thin-walled partsHigh-speed cutting of small cutting force, a higher degree of stability, Machinable with high-quality employees compared to the company may be very good, but other than the company's employees may Suanbu Le outstanding work performance. For our China practice, we use the models to determine the method of staff training needs are simple and effective. This study models can be an external object, it can also be a combination of internal and external. We must first clear strategy for the development of enterprises. Through the internal and external business environment and organizational resources, such as analysis, the future development of a clear business goals and operational priorities. According to the business development strategy can be compared to find the business models, through a comparative analysis of the finalization of business models. In determining business models, a, is the understanding of its development strategy, or its market share and market growth rate, or the staff of the situation, and so on, according to the companies to determine the actual situation. As enterprises in different period of development, its focus is different, which means that enterprises need to invest the manpower and financial resources the focus is different. So in a certain period of time, enterprises should accurately selected their business models compared with the departments and posts, so more practical significance, because the business models are not always good, but to compare some aspects did not have much practical significance, Furthermore This can more fully concentrate on the business use of limited resources. Identify business models, and then take the enterprise of the corresponding departments and staff with the business models for comparison, the two can be found in the performance gap, a comparative analysis to find reasons, in accordance with this business reality, the final identification of training needs. The cost of training is needed, if not through an effective way to determine whether companies need to train and the training of the way, but blind to training, such training is difficult to achieve the desired results. A comparison only difference between this model is simple and practical training.1.5 Can be part of some alternative technology, such as EDM, grinding high intensity and high hardness processingHigh-speed cutting a major feature of high-speed cutting machine has the hardness of HRC60 parts. With the use of coated carbide cutter mold processing, directly to the installation of ahardened tool steel processing forming, effectively avoid the installation of several parts of the fixture error and improve the parts of the geometric location accuracy. In the mold of traditional processing, heat treatment hardening of the workpiece required EDM, high-speed machining replace the traditional method of cutting the processing, manufacturing process possible to omit die in EDM, simplifying the processing technology and investment costs .High-speed milling in the precincts of CNC machine tools, or for processing centre, also in the installation of high-speed spindle on the general machine tools. The latter not only has the processing capacity of general machine tools, but also for high-speed milling, a decrease of investment in equipment, machine tools increased flexibility. Cutting high-speed processing can improve the efficiency, quality improvement, streamline processes, investment and machine tool investment and maintenance costs rise, but comprehensive, can significantly increase economic efficiency.2 High-speed millingHigh-speed milling the main technical high-speed cutting technology is cutting the development direction of one of it with CNC technology, microelectronic technology, new materials and new technology, such as technology development to a higher level. High-speed machine tools and high-speed tool to achieve high-speed cutting is the prerequisite and basic conditions, in high-speed machining in the performance of high-speed machine tool material of choice and there are strict requirements.2.1 High-speed milling machine in order to achieve high-speed machiningGeneral use of highly flexible high-speed CNC machine tools, machining centers, and some use a dedicated high-speed milling, drilling. At the same time a high-speed machine tool spindle system and high-speed feeding system, high stiffness of the main characteristics of high-precision targeting and high-precision interpolation functions, especially high-precision arc interpolation function. High-speed machining systems of the machine a higher demand, mainly in the following areas:General use of highly flexible high-speed CNC machine tools, machining centers, and some use a dedicated high-speed milling, drilling. At the same time a high-speed machine tool spindle system and high-speed feeding system, high stiffness of the main characteristics of high-precision targeting and high-precision interpolation functions, especially high-precision arc interpolation function. High-speed machining systems of the machine a higher demand, mainly in the following areas:High-speed milling machine must have a high-speed spindle, the spindle speed is generally 10000 ~ 100000 m / min, power greater than 15 kW. But also with rapid speed or in designated spots fast-stopping performance. The main axial space not more than 0 .0 0 0 2 m m. Often using high-speed spindle-hydrostatic bearings, air pressure-bearing, mixed ceramic bearings, magneticbearing structure of the form. Spindle cooling general use within the water or air cooled.High-speed processing machine-driven system should be able to provide 40 ~ 60 m / min of the feed rate, with good acceleration characteristics, can provide 0.4 m/s2 to 10 m/s2 acceleration and deceleration. In order to obtain good processing quality, high-speed cutting machines must have a high enough stiffness. Machine bed material used gray iron, can also add a high-damping base of concrete, to prevent cutting tool chatter affect the quality of processing. A high-speed data transfer rate, can automatically increase slowdown. Processing technology to improve the processing and cutting tool life. At present high-speed machine tool manufacturers, usually in the general machine tools on low speed, the feed of the rough and then proceed to heat treatment, the last in the high-speed machine on the half-finished and finished, in improving the accuracy and efficiency at the same time, as far as possible to reduce processing Cost.2.2 High-speed machining toolHigh-speed machining tool is the most active one of the important factors, it has a direct impact on the efficiency of processing, manufacturing costs and product processing and accuracy. Tool in high-speed processing to bear high temperature, high pressure, friction, shock and vibration, such as loading, its hardness and wear-resistance, strength and toughness, heat resistance, technology and economic performance of the basic high-speed processing performance is the key One of the factors. High-speed cutting tool technology development speed, the more applications such as diamond (PCD), cubic boron nitride (CBN), ceramic knives, carbide coating, (C) titanium nitride Carbide TIC (N) And so on. CBN has high hardness, abrasion resistance and the extremely good thermal conductivity, and iron group elements between the great inertia, in 1300 ℃ would not have happened significant role in the chemical, also has a good stability. The experiments show that with CBN cutting toolHRC35 ~ 67 hardness of hardened steel can achieve very high speed. Ceramics have good wear resistance and thermal chemical stability, its hardness, toughness below the CBN, can be used for processing hardness of HRC <5 0 parts. Carbide Tool good wear resistance, but the hardness than the low-CBN and ceramics. Coating technology used knives, cutting tools can improve hardness and cutting the rate, for cutting HRC40 ~ 50 in hardness between the workpiece. Can be used to heat-resistant alloys, titanium alloys, hightemperature alloy, cast iron, Chungang, aluminum and composite materials of high-speed cutting Cut, the most widely used. Precision machining non-ferrous metals or non-metallic materials, or the choice of polycrystalline diamond Gang-coated tool.2.3 High-speed processing technologyHigh-speed cutting technology for high-speed machining is the key. Cutting Methods misconduct, will increase wear tool to less than high-speed processing purposes. Only high-speed machine tool and not a good guide technology, high-speed machining equipment can not fullyplay its role. In high-speed machining, should be chosen with milling, when the milling cutter involvement with the workpiece chip thickness as the greatest, and then gradually decreased. High-speed machining suitable for shallow depth of cut, cutting depth of not more than 0.2 mm, to avoid the location of deviation tool to ensure that the geometric precision machining parts. Ensure that the workpiece on the cutting constant load, to get good processing quality. Cutting a single high-speed milling path-cutting mode, try not to interrupt the process and cutting tool path, reducing the involvement tool to cut the number to be relatively stable cutting process. Tool to reduce the rapid change to, in other words when the NC machine tools must cease immediately, or Jiangsu, and then implement the next step. As the machine tool acceleration restrictions, easy to cause a waste of time, and exigency stop or radical move would damage the surface accuracy. In the mold of high-speed finishing, in each Cut, cut to the workpiece, the feed should try to change the direction of a curve or arc adapter, avoid a straight line adapter to maintain the smooth process of cutting.3 Die in high-speed milling processing ofMilling as a highly efficient high-speed cutting of the new method,inMould Manufacturing has been widely used. Forging links in the regular production model, with EDM cavity to be 12 ~ 15 h, electrodes produced 2 h. Milling after the switch to high-speed, high-speed milling cutter on the hardness of HRC 6 0 hardened tool steel processing. The forging die processing only 3 h20min, improve work efficiency four to five times the processing surface roughness of Ra0.5 ~ 0.6m, fully in line with quality requirements.High-speed cutting technology is cutting technology one of the major developments, mainly used in automobile industry and die industry, particularly in the processing complex surface, the workpiece itself or knives rigid requirements of the higher processing areas, is a range of advanced processing technology The integration, high efficiency and high quality for the people respected. It not only involves high-speed processing technology, but also including high-speed processing machine tools, numerical control system, high-speed cutting tools and CAD / CAM technology. Die-processing technology has been developed in the mold of the manufacturing sector in general, and in my application and the application of the standards have yet to be improved, because of its traditional processing with unparalleled advantages, the future will continue to be an inevitable development of processing technology Direction.4 Numerical control technology and equipping development trend and countermeasureEquip the engineering level, level of determining the whole national economy of the modernized degree and modernized degree of industry, numerical control technology is it develop new developing new high-tech industry and most advanced industry to equip (such as information technology and his industry, biotechnology and his industry, aviation, spaceflight, etc. national defense industry) last technology and getting more basic most equipment. Marx has ever said "the differences of different economic times, do not lie in what is produced, and lie in how to produce,produce with some means of labor ". Manufacturing technology and equipping the most basic means of production that are that the mankind produced the activity, and numerical control technology is nowadays advanced manufacturing technology and equips the most central technology. Nowadays the manufacturing industry all around the world adopts numerical control technology extensively, in order to improve manufacturing capacity and level, improve the adaptive capacity and competitive power to the changeable market of the trends. In addition every industrially developed country in the world also classifies the technology and numerical control equipment of numerical control as the strategic materials of the country, not merely take the great measure to develop one's own numerical control technology and industry, and implement blockading and restrictive policy to our country in view of " high-grade, precision and advanced key technology of numerical control " and equipping. In a word, develop the advanced manufacturing technology taking numerical control technology as the core and already become every world developed country and accelerate economic development in a more cost-effective manner, important way to improve the overall national strength and national position. Numerical control technology is the technology controlled to mechanical movement and working course with digital information, integrated products of electromechanics that the numerical control equipment is the new technology represented by numerical control technology forms to the manufacture industry of the tradition and infiltration of the new developing manufacturing industry, namely the so-called digitization is equipped, its technological range covers a lot of fields: (1)Mechanical manufacturing technology; (2)Information processing, processing, transmission technology; (3)Automatic control technology; (4)Servo drive technology;(5)Technology of the sensor; (6)Software engineering ,etc..Development trend of a numerical control technologyThe application of numerical control technology has not only brought the revolutionary change to manufacturing industry of the tradition, make the manufacturing industry become the industrialized symbol , and with the constant development of numerical control technology and enlargement of the application, the development of some important trades (IT , automobile , light industry , medical treatment ,etc. ) to the national economy and the people's livelihood of his plays a more and more important role, because the digitization that these trades needed to equip has already been the main trend of modern development. Numerical control technology in the world at present and equipping the development trend to see, there is the following several respect [1- ] in its main research focus.5 A high-speed, high finish machining technology and new trend equippedThe efficiency, quality are subjavanufacturing technology. High-speed, high finish machining technology can raise the efficiency greatly , improve the quality and grade of the products, shorten production cycle and improve the market competitive power. Japan carries the technological research association first to classify it as one of the 5 great modern manufacturing technologies forthis, learn (CIRP) to confirm it as the centre in the 21st century and study one of the directions in international production engineering.In the field of car industry, produce one second when beat such as production of 300,000 / vehicle per year, and many variety process it is car that equip key problem that must be solved one of; In the fields of aviation and aerospace industry, spare parts of its processing are mostly the thin wall and thin muscle, rigidity is very bad, the material is aluminium or aluminium alloy, only in a situation that cut the speed and cut strength very small high, could process these muscles, walls. Adopt large-scale whole aluminium alloy method that blank " pay empty " make the wing recently, such large-scale parts as the fuselage ,etc. come to substitute a lot of parts to assemble through numerous rivet , screw and other connection way, make the intensity , rigidity and dependability of the component improved. All these, to processing and equipping the demand which has proposed high-speed, high precise and high flexibility.According to EMO2001 exhibition situation, high-speed machining center is it give speed can reach 80m/min is even high , air transport competent speed can up to 100m/min to be about to enter. A lot of automobile factories in the world at present, including Shanghai General Motors Corporation of our country, have already adopted and substituted and made the lathe up with the production line part that the high-speed machining center makes up. HyperMach lathe of U.S.A. CINCINNATI Company enters to nearly biggest 60m/min of speed, it is 100m/min to be fast, the acceleration reaches 2g, the rotational speed of the main shaft has already reached 60 000r/min. Processing a thin wall of plane parts, spend 30min only, and same part general at a high speed milling machine process and take 3h, the ordinary milling machine is being processed to need 8h; The speed and acceleration of main shaft of dual main shaft lathes of Germany DMG Company are up to 120000r/mm and 1g.In machining accuracy, the past 10 years, ordinary progression accuse of machining accuracy of lathe bring 5μm up to from 10μm already, accurate grades of machining center from 3~5μm, rise to 1~1.5μm, and ultraprecision machining accuracy is i t enter nanometer grade to begin already (0.01μm).In dependability, MTBF value of the foreign numerical control device has already reached above 6 000h, MTBF value of the servo system reaches above 30000h, demonstrate very high dependability .In order to realize high-speed, high finish machining, if the part of function related to it is electric main shaft, straight line electrical machinery get fast development, the application is expanded further .5.2 Link and process and compound to process the fast development of the lathe in 5 axesAdopt 5 axles to link the processing of the three-dimensional curved surface part, can cut with the best geometry form of the cutter , not only highly polished, but also efficiency improves by a large margin . It is generally acknowledged, the efficiency of an 5 axle gear beds can equal 2 3 axle gearbeds, is it wait for to use the cubic nitrogen boron the milling cutter of ultra hard material is milled and pared at a high speed while quenching the hard steel part, 5 axles link and process 3 constant axles to link and process and give play to higher benefit. Because such reasons as complicated that 5 axles link the numerical control system , host computer structure that but go over, it is several times higher that its price links the numerical control lathe than 3 axles , in addition the technological degree of difficulty of programming is relatively great, have restricted the development of 5 axle gear beds.At present because of electric appearance of main shaft, is it realize 5 axle complex main shaft hair structure processed to link greatly simplify to make, it makes degree of difficulty and reducing by a large margin of the cost, the price disparity of the numerical control system shrinks. So promoted 5 axle gear beds of head of complex main shaft and compound to process the development of the lathe (process the lathe including 5).At EMO2001 exhibition, new Japanese 5 of worker machine process lathe adopt complex main shaft hair, can realize the processing of 4 vertical planes and processing of the wanton angle, make 5 times process and 5 axles are processed and can be realized on the same lathe, can also realize the inclined plane and pour the processing of the hole of awls. Germany DMG Company exhibits the DMUVoution series machining center, but put and insert and put processing and 5 axles 5 times to link and process in once, can be controlled by CNC system or CAD/CAM is controlled directly or indirectly.5.3 Become the main trend of systematic development of contemporary numerical control intelligently, openly, networkedly.The numerical control equipment in the 21st century will be sure the intelligent system, the intelligent content includes all respects in the numerical control system: It is intelligent in order to pursue the efficiency of processing and process quality, control such as the self-adaptation of the processing course, the craft parameter is produced automatically; Join the convenient one in order to improve the performance of urging and use intelligently, if feedforward control , adaptive operation , electrical machinery of parameter , discern load select models , since exactly makes etc. automatically; The ones that simplified programming , simplified operating aspect are intelligent, for instance intelligent automatic programming , intelligent man-machine interface ,etc.; There are content of intelligence diagnose , intelligent monitoring , diagnosis convenient to be systematic and maintaining ,etc..Produce the existing problem for the industrialization of solving the traditional numerical control system sealing and numerical control application software. A lot of countries carry on research to the open numerical control system at present, such as NGC of U.S.A. (The Next Generation Work-Station/Machine Control), OSACA of European Community (Open System Architecture for Control within Automation Systems), OSEC (Open System Environment for Controller) of Japan, ONC (Open Numerical Control System) of China, etc.. The numerical control system melts tobecome the future way of the numerical control system open. The so-called open numerical control system is the development of the numerical control system can be on unified operation platform, face the lathe producer and end user, through changing, increasing or cutting out the structure target(numerical control function), form the serration, and can use users specially conveniently and the technical know-how is integrated in the control 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, communication norm , disposing norm , operation platform , numerical control systematic function storehouse and numerical control systematic function software development ,etc. are the core of present research.The networked numerical control equipment is a new light spot of the fair of the internationally famous lathe in the past two years. Meeting production line , manufacture system , demand for the information integration of manufacturing company networkedly greatly of numerical control equipment, realize new manufacture mode such as quick make , fictitious enterprise , basic Entrance that the whole world make too. Some domestic and international famous numerical control lathes and systematic manufacturing companies of numerical control have all introduced relevant new concepts and protons of a machine in the past two years, if in EMO2001 exhibition, " Cyber Production Center " that the company exhibits of mountain rugged campstool gram in Japan (Mazak) (intellectual central production control unit, abbreviated as CPC); The lathe company of Japanese big Wei (Okuma ) exhibits " IT plaza " (the information technology square , is abbreviated as IT square ); Open Manufacturing Environment that the company exhibits of German Siemens (Siemens ) (open the manufacturing environment, abbreviated as OME),etc., have reflected numerical control machine tooling to the development trend of networked direction.5.4 Pay attention to the new technical standard, normal setting-up5.4.1 Design the norm of developing about the numerical control systemAs noted previously, there are better common ability, flexibility, adaptability, expanding in the open numerical control system, such countries as U.S.A. ,European Community and Japan ,etc. implement the strategic development plan one after another , carry on the research and formulation of the systematic norm (OMAC , OSACA , OSEC ) of numerical control of the open system structure, 3 biggest economies in the world have carried on the formulation that nearly the same science planned and standardized in a short time, have indicated a new arrival of period of change of numerical control technology. Our country started the research and formulation of standardizing the frame of ONC numerical control system of China too in 2000.5.4.2 About the numerical control standardThe numerical control standard is a kind of trend of information-based development of manufacturing industry. Information exchange among 50 years after numerical control technology was born was all because of ISO6983 standard, namely adopt G, M code describes how processes,。
(完整版)机械类专业英语课文参考翻译
第一课Text:It is known that metals are very important in our life. Metals have the greatest importance for industry. All machines and other engineering[7endVi5niEriN] constructions have metal[5metl] parts; some of them consist only of metal parts.众所周知,金属在我们的生活中是非常重要的,金属对于工业而言是有巨大的重要性,所有机器和其他工程构造都有金属零部件,其中一些还只能由金属组成。
There are two large groups of metals:1) Simple metal- more or less pure chemical elements[5elimEnt]2) Alloys[5AlCi]- materials consisting of a simple metal combined with some other elements.有两大类金属:(1)纯金属——或多或少的金属元素(2)合金——组成纯金属的原料结合其他元素。
About two thirds of all elements found in the earth are metals, but not all metals may be used in industry. Those metals which are used in industry are called engineering metals. The most important engineering metalis iron[5aiEn], which in the form of alloys with carbon[5kB:bEn] and other elements, finds greater use than any other metal. Metals consisting of iron combined with some other elements are known as ferrous[5ferEs] metals; all the other metals are called nonferrous[5nCn5ferEs] metals. The most important nonferrous metal arecopper[5kCpE], aluminum[E5lju:minEm], lead[li:d], zinc[ziNk], tin[tin], but all these metals are used muchless than ferrous metals, because the ferrous metals are much cheaper.在地球上发现的所有元素中,大约三分之二是金属元素,但是并不是所有的金属都能够用于工业上。
《机械外文翻译文献翻译液压传动》
英文原文Hydraulic SystemHydraulic presser drive and air pressure drive hydraulic fluid as the transmission is made according to the 17th century, Pascal's principle of hydrostatic pressure to drive the development of an emerging technology, the United Kingdo m in 1795 • Braman Joseph (Joseph Braman ,1749-1814), in London water as a medium to form hydraulic press used in industry, the birth of the world's first hydraulic press. Media work in 1905 will be replaced by oil-water and further improved.Hydraulic transmission There are many outstanding advantages, it is widely used, such as general industr- ial use of plastics processing machinery, the pressure of machinery, machine tools, etc.; operating machinery engineering machinery, construction machinery, agricultural machinery, automobiles, etc.; iron and steel indu- stry metallurgical machinery, lifting equipment, such as roller adjustment device; civil water projects with flo- od control and dam gate devices, bed lifts installations, bridges and other manipulation of institutions; speed turbine power plant installations, nuclear power plants, etc.; ship from the deck heavy machinery (winch), the bow doors, bulkhead valve, stern thruster, etc.; special antenna technology giant with control devices, measu- rement buoys, movements such as rotating stage; military-industrial control devices used in artillery, ship anti- rolling devices, aircraft simulation, aircraft retractable landing gear and rudder control devices and other devi- ces.A complete hydraulic system consists of five parts, namely, power components, the implementation of co- mponents, control components, auxiliary components and hydraulic oil.The role of dynamic components of the original motive fluid into mechanical energy to the pressure that the hydraulic system of pumps, it is to power the entire hydraulic system. The structure of the form of hydra- ulic pump gears are generally pump, vane pump and piston pump.Implementation of components (such as hydraulic cylinders and hydraulic motors) which is the pressure of the liquid can be converted to mechanical energy to drive the load for a straight line reciprocating movement or rotational movement.Control components (that is, the various hydraulic valves) in the hydraulic system to control and regulate the pressure of liquid, flow rate and direction. According to the different control functions, hydraulic pressure control valve can be divided into valves, flow control valves and directional control valve. Pressure control valves are divided into benefits flow valve (safety valve), pressure relief valve, sequence valve, pressure relays, etc.; flow control valves including throttle, adjusting the valves, flow diversion valve sets, etc.; directional control valve includes a one-way valve , one-way fluid control valve, shuttle valve, valve and so on. Under the control of different ways, can be divided into the hydraulic valve control switch valve, control valve and set the value of the ratio control valve.Auxiliary components, including fuel tanks, oil filters, tubing and pipe joints, seals, pressure gauge, oil level, such as oil dollars.Hydraulic oil in the hydraulic system is the work of the energy transfer medium, there are a variety of mineral oil, emulsion oil hydraulic molding Hop categories.The role of the hydraulic system is to help humanity work. Mainly by the implementation of components to rotate or pressure into a reciprocating motion.Hydraulic system and hydraulic power control signal is composed of two parts, the signal control of some parts of the hydraulic power used to drive the control valve movement.Part of the hydraulic power means that the circuit diagram used to show the different functions of the interrelationship between components. Containing the source of hydraulic pump, hydraulic motor and auxiliary components; hydraulic control part contains a variety of control valves, used to control the flow of oil, pressure and direction; operative or hydraulic cylinder with hydraulic motors, according to the actual requirements of their choice.In the analysis and design of the actual task, the general block diagram shows the actual operation of equi - pment. Hollow arrow indicates the signal flow, while the solid arrows that energy flow.Basic hydraulic circuit of the action sequence - Control components (two four-way valve) and the spring to reset for the implementation of components (double-acting hydraulic cylinder), as well as the extending and retracting the relief valve opened and closed . For the implementation of components and control components, presentations are based on the corresponding circuit diagram symbols, it also introduced ready made circuit diagram symbols.Working principle of the system, you can turn on all circuits to code. If the first implementation of components numbered 0, the control components associated with the identifier is 1. Out with the implementation of components corresponding to the identifier for the even components, then retracting and implementation of components corresponding to the identifier for the odd components. Hydraulic circuit carried out not only to deal with numbers, but also to deal with the actual device ID, in order to detect system failures.DIN ISO1219-2 standard definition of the number of component composition, which includes the following four parts: device ID, circuit ID, component ID and component ID. The entire system if only one device, device number may be omitted.Practice, another way is to code all of the hydraulic system components for numbers at this time, components and component code should be consistent with the list of numbers. This method is particularly applicable to complex hydraulic control system, each control loop are the corresponding number with the systemWith mechanical transmission, electrical transmission compared to the hydraulic drive has the following advantages:1, a variety of hydraulic components, can easily and flexibly to layout.2, light weight, small size, small inertia, fast response.3, to facilitate manipulation of control, enabling a wide range of stepless speed regulation (speed range of 2000:1).4, to achieve overload protection automatically.5, the general use of mineral oil as a working medium, the relative motion can be self-lubricating surface, long service life;6, it is easy to achieve linear motion /7, it is easy to achieve the automation of machines, when the joint control of the use of electro-hydraulic, not only can achieve a higher degree of process automation, and remote control can be achieved.The shortcomings of the hydraulic system:1, as a result of the resistance to fluid flow and leakage of the larger, so less efficient. If not handled properly, leakage is not only contaminated sites, but also may cause fire and explosion.2, vulnerable performance as a result of the impact of temperature change, it would be inappropriate in the high or low temperature conditions.3, the manufacture of precision hydraulic components require a higher, more expensive and hence the price. 4, due to the leakage of liquid medium and the compressibility and can not be strictly the transmission ratio. 5, hydraulic transmission is not easy to find out the reasons for failure; the use and maintenance requirements for a higher level of technology.In the hydraulic system and its system, the sealing device to prevent leakage of the work of media within and outside the dust and the intrusion of foreign bodies. Seals played the role of components, namely seals. Medium will result in leakage of waste, pollution and environmental machinery and even give rise to malfunctioning machinery and equipment for personal accident. Leakage within the hydraulic system will cause a sharp drop in volumetric efficiency, amounting to less than the required pressure, can not even work. Micro-invasive system of dust particles, can cause or exacerbate friction hydraulic component wear, and further lead to leakage.Therefore, seals and sealing device is an important hydraulic equipment components. The reliability of its机械专业中英文文献翻译work and life, is a measure of the hydraulic system an important indicator of good or bad. In addition to the closed space, are the use of seals, so that two adjacent coupling surface of the gap between the need to control the liquid can be sealed following the smallest gap. In the contact seal, pressed into self-seal-style and self-styled self-tight seal (ie, sealed lips) two.The three hydraulic system diseases1, as a result of heat transmission medium (hydraulic oil) in the flow velocity in various parts of the existence of different, resulting in the existence of a liquid within the internal friction of liquids and pipelines at the sam- e time there is friction between the inner wall, which are a result of hydraulic the reasons for the oil tempera- ture. Temperature will lead to increased internal and external leakage, reducing its mechanical efficiency. At the same time as a result of high temperature, hydraulic oil expansion will occur, resulting in increased com- pression, so that action can not be very good control of transmission. Solution: heat is the inherent characte -ristics of the hydraulic system, not only to minimize eradication. Use a good quality hydraulic oil, hydraulic piping arrangement should be avoided as far as possible the emergence of bend, the use of high-quality pipe and fittings, hydraulic valves, etc.2, the vibration of the vibration of the hydraulic system is also one of its malaise. As a result of hydraulic oil in the pipeline flow of high-speed impact and the control valve to open the closure of the impact of the process are the reasons for the vibration system. Strong vibration control action will cause the system to error, the system will also be some of the more sophisticated equipment error, resulting in system failures. Solutions: hydraulic pipe should be fixed to avoid sharp bends. To avoid frequent changes in flow direction, can not avoid damping measures should be doing a good job. The entire hydraulic system should have a good damping measures, while avoiding the external local oscillator on the system.3, the leakage of the hydraulic system leak into inside and outside the leakage leakage. Leakage refers to the process with the leak occurred in the system, such as hydraulic piston-cylinder on both sides of the leakage, the control valve spool and valve body, such as between the leakage. Although no internal leakage of hydra- ulic fluid loss, but due to leakage, the control of the established movements may be affected until the cause system failures. Outside means the occurrence of leakage in the system and the leakage between the external environment. Direct leakage of hydraulic oil into the environment, in addition to the system will affect the working environment, not enough pressure will cause the system to trigger a fault. Leakage into the enviro- nment of the hydraulic oil was also the danger of fire. Solution: the use of better quality seals to improve the machining accuracy of equipment.Another: the hydraulic system for the three diseases, it was summed up: "fever, with a father拉稀" (This is the summary of the northeast people). Hydraulic system for the lifts, excavators, pumping station, dynamic, crane, and so on large-scale industry, construction, factories, enterprises, as well as elevators, lifting platforms, Deng Axle industry and so on.Hydraulic components will be high-performance, high-quality, high reliability, the system sets the direction of development; to the low power, low noise, vibration, without leakage, as well as pollution control, water-based media applications to adapt to environmental requirements, such as the direction of development; the development of highly integrated high power density, intelligence, mechatronics and micro-light mini-hydraulic components; active use of new techniques, new materials and electronics, sensing and other high-tech.Hydraulic coupling to high-speed high-power and integrated development of hydraulic transmission equ- ipment, development of water hydraulic coupling medium speed and the field of automotive applications to develop hydraulic reducer, improve product reliability and working hours MTBF; hydraulic torque converter to the development of high-power products, parts and components to improve the manufacturing process tech -nology to improve reliability, promote computer-aided technology, the development of hydraulic torque con- verter and power shift transmission technology supporting the use of ; Clutch fluid viscosity should increase the quality of products, the formation of bulk to the high-power and high-speed direction.Pneumatic Industry:Products to small size, light weight, low power consumption, integrated portfolio of development, the implementation of the various types of components, compact structure, high positioning accuracy of the direction of development; pneumatic components and electronic technology, to the intelligent direction of development; component performance to high-speed, high-frequency, high-response, high-life, high temp- erature, high voltage direction, commonly used oil-free lubrication, application of new technology, new technology and new materials.(1)used high-pressure hydraulic components and the pressure of continuous work to reach 40Mpa, the maximum pressure to achieve instant 48Mpa;(2) diversification of regulation and control;(3) to further improve the regulation performance, increase the efficiency of the powertrain;(4) development and mechanical, hydraulic, power transmission of the composite portfolio adjustment gear;(5) development of energy saving, energy efficient system function;(6) to further reduce the noise;(7) Application of Hydraulic Cartridge V alves thread technology, compact structure, to reduce the oil spill Water-based hydraulic systemsWater-based hydraulic systems traditionally have been used in hot-metal areas of steel mills. The obvious advantage of water systems in these industries is their fire resistance. Water-based hydraulic systems also have obvious cost advantages over oil-based fluid. First, non-toxic, biodegradable synthetic additives for water cost $5 to $6 per gallon. One gallon of concentrate can make 20 gallons of a 5% solution, so the cost of water-based hydraulic fluid actually can be less than 30 cents per gallon.Considering the costs associated with preventing and cleaning up environmental contamination, water-based hydraulic systems hold the potential for tremendous cost savings at the plant level. Oil that has leaked already becomes a very important problem. It must be collected, properly contained. Water containing synthetic additives, however, can by dumped into plant effluent systems.Cost savings at the plant level don't stop at the lower cost of the fluid and its disposal. Because water-based hydraulic fluid consists of 10 parts water and one part synthetic additive, 5 gallons of additive mixes with water to make 100 gallons of water-based fluid. A 50gallon container is certainly easier to handle than two 55-gallon drums, so warehousing is simpler, cleaner, and less cluttered. Transportation costs also are lower.Other potential plant-wide savings include improved safety for workers because the water-based fluid is non-toxic as well as non-flammable. These attributes can reduce plant insurance rates. Spills cost less to clean up because granular absorbents or absorbent socks are unnecessary. Water is "hot" againThe oil embargo in the 1970s sparked interest in water-based fluids as a less-costly alternative to oils. Even the most expensive water additives became attractive when designers learned that one gallon of concentrate would make 20 gallons of fluid.As oil prices gradually dropped, so did interest in water-based hydraulics. In retrospect, interest in water-based fluids centered around their cost saving potential. Most designers lost interest when they discovered that they could not just change the fluid in their systems from oil to water without making other substantial changes. They then become reluctant to accept other "disadvantages" - read substantial changes - of switching over to water-based hydraulics.What were viewed as disadvantages were really different rules that apply to water-based hydraulic systems? Designers probably resisted learning more about water-based hydraulics because they were intimated by all the work required to lean about how to design a new system or retrofit an older system. By closing their minds to this different technology, they missed the many other advantages of water-based fluid beyond initial cost. Now that environmental concerns have added disposal costs to the price of hydraulic fluids, water-based hydraulics has again become a hot topic.Fighting freezeWater-based hydraulic systems do, of course, have limits to their applications. One limitation is the potential of freezing. This possibility is probably the most significant blockade to more widespread application of机械专业中英文文献翻译water-based systems, especially in the mobile equipment industry. Longwall mining is by far the largest sector of mobile equipment that has been able to take advantage of water-based systems. Temperatures underground do not approach the freezing point of water, and fire resistance is essential. Mobile and even marine equipment used in temperate climates could cash in one the advantages of water based systems, but there is no guarantee that such equipment always will be used in above-freezing temperatures.Nevertheless, adding an anti-freeze to a water-based fluid can depress its freezing temperature to well below 32°F. Ethylene glycol - used in automotive anti-freeze - is toxic and is not biodegradable, so its use for anti-freeze in water-based hydraulic fluid would defeat the environmental advantage water-based fluid has. There is an alternative. Propylene glycol is not toxic and is biodegradable. It costs more than ethylene glycol and is not quite as effective antifreeze, so it must be used in slightly higher concentrations. Two more techniques to reduce freezing potential are to keep fluid circulating continuously and use hose where practical. Sealing the systemTwo more perceived problems with water hydraulic systems are bacterial infestation and difficulty in maintain proper concentrations. Sealing the system from atmosphere can hold bacterial growth in check. Addition of an anti-bacterial agent to the fluid can have a lasting effect on preventing bacterial buildup if air is excluded from the system.A sealed reservoir eliminates another problem suffered by many hydraulic systems: water ingression. This addresses another misconception about water-based systems: water-based systems not sealed from the atmosphere must be closely monitored to ensure that the additive concentration stays within tolerance. That is because water evaporates from the reservoir more readily than the additive does. Consequently, water evaporation causes the additive concentration to increase. When new fluid is added to a system, samples of the existing fluid must be taken to determine the concentration of additive in solution. These results then reveal the ratio of additive to fluid that must be added so that fluid concentration is correct.With a system that seals fluid from the atmosphere, the evaporation problem is virtually eliminated. Fluid that escapes by leakage is a solution containing water and additive. Therefore, the quantity of fluid in the system changes, but concentration does not. System fluid is replen ished simply by adding a pre-mixed solution of water and additive to the reservoir.中文原文液压传动液压传动和气压传动称为流体传动,是根据17世纪帕斯卡提出的液体静压力传动原理而发展起来的一门新兴技术,1795年英国约瑟夫•布拉曼(Joseph Braman,1749-1814),在伦敦用水作为工作介质,以水压机的形式将其应用于工业上,诞生了世界上第一台水压机。
机械专业外文文献翻译--对振动侦查和测量的一种实用方法
英文原文A Practical Approach to Vibration Detection and Measurement——Physical Principles and Detection TechniquesBy: John Wilson, the Dynamic Consultant, LLCThis tutorial addresses the physics of vibration; dynamics of a spring mass system; damping; displacement, velocity, and acceleration; and the operating principles of the sensors that detect and measure these properties. Vibration is oscillatory motion resulting from the application of oscillatory or varying forces to a structure. Oscillatory motion reverses direction. As we shall see, the oscillation may be continuous during some time period of interest or it may be intermittent. It may be periodic or nonperiodic, i.e., it may or may not exhibit a regular period of repetition. The nature of the oscillation depends on the nature of the force driving it and on the structure being driven.Motion is a vector quantity, exhibiting a direction as well as a magnitude. The direction of vibration is usually described in terms of some arbitrary coordinate system (typically Cartesian or orthogonal) whose directions are called axes. The origin for the orthogonal coordinate system of axes is arbitrarily defined at some convenient location.Most vibratory responses of structures can be modeled as single-degree-of-freedom spring mass systems, and many vibration sensors use a spring mass system as the mechanical part of their transduction mechanism. In addition to physical dimensions, a spring mass system can be characterized by the stiffness of the spring, K, and the mass, M, or weight, W, of the mass. These characteristics determine not only the static behavior (static deflection, d) of the structure, but also its dynamic characteristics. If g is the acceleration of gravity:F = MAW = MgK = F/d = W/dd = F/K = W/K = Mg/KDynamics of a Spring Mass SystemThe dynamics of a spring mass system can be expressed by the system's behavior in free vibration and/or in forced vibration.Free Vibration. Free vibration is the case where the spring is deflected and then released and allowed to vibrate freely. Examples include a diving board, a bungee jumper, and a pendulum or swing deflected and left to freely oscillate.Two characteristic behaviors should be noted. First, damping in the system causes the amplitude of the oscillations to decrease over time. The greater the damping, the faster the amplitude decreases. Second, thefrequency or period of the oscillation is independent of the magnitude of the original deflection (as long as elastic limits are not exceeded). The naturally occurring frequency of the free oscillations is called the natural frequency, f n:(1)Forced Vibration. Forced vibration is the case when energy is continuously added to the spring mass system by applying oscillatory force at some forcing frequency, f f. Two examples are continuously pushing a child on a swing and an unbalanced rotating machine element. If enough energy to overcome the damping is applid, the motion will continue as long as the excitation continues. Forced vibration may take the form of self-excited or externally excited vibration. Self-excited vibration occurs when the excitation force is generated in or on the suspended mass; externally excited vibration occurs when the excitation force is applied to the spring. This is the case, for example, when the foundation to which the spring is attached is moving.Transmissibility. When the foundation is oscillating, and force is transmitted through the spring to the suspended mass, the motion of the mass will be different from the motion of the foundation. We will call the motion of the foundation the input, I, and the motion of the mass the response, R. The ratio R/I is defined as the transmissibility, Tr:Tr = R/IResonance. At forcing frequencies well below the system's natural frequency, R I, and Tr 1. As the forcing frequency approaches the natural frequency, transmissibility increases due to resonance. Resonance is the storage of energy in the mechanical system. At forcing frequencies near the natural frequency, energy is stored and builds up, resulting in increasing response amplitude. Damping also increases with increasing response amplitude, however, and eventually the energy absorbed by damping, per cycle, equals the energy added by the exciting force, and equilibrium is reached. We find the peak transmissibility occurring when f f f n. This condition is called resonance.Isolation. If the forcing frequency is increased above f n, R decreases. When f f = 1.414 fn, R = I and Tr = 1; at higher frequencies R <I and Tr <1. At frequencies when R <I, the system is said to be in isolation. That is, someof the vibratory motion input is isolated from the suspended mass.Effects of Mass and Stiffness Variations. From Equation (1) it can be seen that natural frequency is proportional to the square root of stiffness, K, and inversely proportional to the square root of weight, W, or mass, M. Therefore, increasing the stiffness of the spring or decreasing the weight of the mass increases natural frequency.DampingDamping is any effect that removes kinetic and/or potential energy from the spring mass system. It is usually theresult of viscous (fluid) or frictional effects. All materials and structures have some degree of internal damping. In addition, movement through air, water, or other fluids absorbs energy and converts it to heat. Internal intermolecular or intercrystalline friction also converts material strain to heat. And, of course, external friction provides damping.Damping causes the amplitude of free vibration to decrease over time, and also limits the peak transmissibility in forced vibration. It is normally characterized by the Greek letter zeta () , or by the ratio C/C c, where c is the amount of damping in the structure or material and C c is "critical damping." Mathematically, critical damping is expressed as C c = 2(KM)1/2. Conceptually, critical damping is that amount of damping which allows the deflected spring mass system to just return to its equilibrium position with no overshoot and no oscillation. An underdamped system will overshoot and oscillate when deflected and released. An overdamped system will never return to its equilibrium position; it approaches equilibrium asymptotically. Displacement, Velocity, and AccelerationSince vibration is defined as oscillatory motion, it involves a change of position, or displacement (see Figure 1).Figure 1.Phase relationships among displacement, velocity, and acceleration are shown on these time history plots.Velocity is defined as the time rate of change of displacement; acceleration is the time rate of change of velocity. Some technical disciplines use the term jerk to denote the time rate of change of acceleration.Sinusoidal Motion Equation. The single-degree-of-freedom spring mass system, in forced vibration, maintained at a constant displacement amplitude, exhibits simple harmonic motion, or sinusoidal motion. That is, its displacement amplitude vs. time traces out a sinusoidal curve. Given a peak displacement of X, frequency f, and instantaneous displacement x:(2)at any time, t.Velocity Equation. Velocity is the time rate of change of displacement, which is the derivative of the time function of displacement. For instantaneous velocity, v:(3)Since vibratory displacement is most often measured in terms of peak-to-peak, double amplitude, displacement D = 2X:(4)If we limit our interest to the peak amplitudes and ignore the time variation and phase relationships:(5)where:V = peak velocityAcceleration Equation. Similarly, acceleration is the time rate of change of velocity, the derivative of the velocity expression:(6)and(7)where:A = peak accelerationIt thus can be shown that:V = fDA = 22 f2 DD = V/ fD = A/22 f2From these equations, it can be seen that low-frequency motion is likely to exhibit low-amplitude accelerations even though displacement may be large. It can also be seen that high-frequency motion is likely to exhibit low-amplitude displacements, even though acceleration is large. Consider two examples:• At 1 Hz, 1 in. pk-pk displacement is only ~0.05 g acceleration; 10 in. is ~0.5 g • At 1000 Hz, 1g acceleration is only ~0.00002 in. displacement; 100 g is ~0.002 in.Measuring Vibratory DisplacementOptical Techniques. If displacement is large enough, as at low frequencies, it can be measured with a scale, calipers, or a measuring microscope. At higher frequencies, displacement measurement requires more sophisticated optical techniques.High-speed movies and video can often be used to measure displacements and are especially valuable for visualizing the motion of complex structures and mechanisms. The two methods are limited by resolution to fairly large displacements and low frequencies. Strobe lights and stroboscopic photography are also useful when displacements are large enough, usually >0.1 in., to make them practical.The change in intensity or angle of a light beam directed onto a reflective surface can be used as an indication of its distance from the source. If the detection apparatus is fast enough, changes of distance can be detected as well.The most sensitive, accurate, and precise optical device for measuring distance or displacement is the laser interferometer. With this apparatus, a reflected laser beam is mixed with the original incident beam. The interference patterns formed by the phase differences can measure displacement down to <100 nm. NIST and other national primary calibration agencies use laser interferometers for primary calibration of vibration measurement instruments at frequencies up to 25 kHz.Electromagnetic and Capacitive Sensors. Another important class of noncontact, special-purpose displacement sensors is the general category of proximity sensors. These are probes that are typically built into machinery to detect the motion of shafts inside journal bearings or the relative motion of other machine elements. The sensors measure relative distance or proximity as a function of either electromagnetic or capacitive (electrostatic) coupling between the probe and the target. Because these devices rely on inductive or capacitive effects, they require an electrically conductive target. In most cases, they must be calibrated for a specific target and specific material characteristics in the gap between probe and target.Electromagnetic proximity sensors are often called eddy current probes because one of the most popular types uses eddy currents generated in the target as its measurement mechanism. More accurately, this type of sensor uses the energy dissipated by the eddy currents. The greater the distance from probe to target, the less electromagnetic coupling, the lower the magnitude of the eddy currents, and the less energy they drain from theprobe. Other electromagnetic probes sense the distortion of an electromagnetic field generated by the probe and use that measurement to indicate the distance from probe to target.Capacitive proximity sensor systems measure the capacitance between the probe and the target and are calibrated to convert the capacitance to distance. Capacitance is affected by the dielectric properties of the material in the gap as well as by distance, so calibration can be affected by a change of lubricant or contamination of the lubricant in a machine environment.Contact Techniques. A variety of relative motion sensors use direct contact with two objects to measure relative motion or distance between them. These include LVDTs, cable position transducers (stringpots), and linear potentiometers. All of these devices depend on mechanical linkages and electromechanical transducers.Seismic Displacement Transducers. These devices, discussed in detail later, were once popular but now are seldom used. They tend to be large, heavy, and short lived.Double Integration of Acceleration. With the increasing availability and decreasing cost of digital signal processing, more applications are using the more rugged and more versatile accelerometers as sensors, then double integrating the acceleration signal to derive displacements. While older analog integration techniques tended to be noisy and inaccurate, digital processing can provide quite high-quality, high-accuracy results.Measuring Vibratory VelocityTransducers. Some of the earliest "high-frequency" vibration measurements were made with electrodynamic velocity sensors. These are a type of seismic transducer that incorporates a magnet supported on a soft spring suspension system to form the seismic (spring mass) system. The magnetic member is suspended in a housing that contains one or more multiturn coils of wire. When the housing is vibrated at frequencies well above the natural frequency of the spring mass system, the mass (magnet) is isolated from the housing vibration. Thus, the magnet is essentially stationary and the housing, with the coils, moves past it at the velocity of the structure to which it is attached. Electrical output is generated proportional to the velocity of the coil moving through the magnetic field. Velocity transducers are used from ~10 Hz up to a few hundred Hz. They tend to be large and heavy, and eventually wear and produce erratic outputs.Laser Vibrometers. Laser vibrometers or laser velocimeters are relatively new instruments capable of providing high sensitivity and accuracy. They use a frequency-modulated (typically around 44 MHz) laser beam reflected from a vibrating surface. The reflected beam is compared with the original beam and the Doppler frequency shift is used to calculate the velocity of the vibrating surface. Alignment and standoff distance are critical. Because of the geometric constraints on location, alignment, and distances, they are limited to laboratory applications. One version of laser vibrometer scans the laser beam across a field of vision, measuring velocity at each point. The composite can then be displayed as a contour map or a colorized display. The vibration map can be superimposed on a video image to provide the maximum amount of information about velocity variations on a large surface.Integration of Acceleration. As with displacement measurements, low-cost digital signal processing makes it practical to use rugged, reliable, versatile accelerometers as sensors and integrate their output to derive a velocity signal.Measuring Vibratory AccelerationMost modern vibration measurements are made by measuring acceleration. If velocity or displacement data are required, the acceleration data can be integrated (velocity) or double integrated (displacement). Some accelerometer signal conditioners have built-in integrators for that purpose. Accelerometers (acceleration sensors, pickups, or transducers) are available in a wide variety of sizes, shapes, performance characteristics, and prices. The five basic transducer types are servo force balance; crystal-type or piezoelectric; piezoresistive or silicon strain gauge type; integral electronics piezoelectric; and variable capacitance. Despite the different electromechanical transduction mechanisms, all use a variation of the spring mass system, and are classified as seismic transducers.Seismic Accelerometer Principle. All seismic accelerometers use some variation of a seismic or proof mass suspended by a spring structure in a case (see Figure 3). When the case is accelerated, the proof mass is also accelerated by the force transmitted through the spring structure. Then the displacement of the spring, the displacement of the mass within the case, or the forcetransmitted by the spring is transduced into an electrical signal proportional to acceleration.Accelerometers. Transducers designed to measure vibratory acceleration are called accelerometers. There are many varieties including strain gauge, servo force balance, piezoresistive (silicon strain gauge), piezoelectric (crystal-type), variable capacitance, and integral electronic piezoelectric. Each basic type has many variations and trade names. Most manufacturers provide excellent applications engineering assistance to help the user choose the best type for the application, but because most of these sources sell only one or two types, they tend to bias their assistance accordingly.For most applications, my personal bias is toward piezoelectric accelerometers with internal electronics. The primary limitation of these devices is temperature range. Although they exhibit low-frequency roll-off, they are available with extremely low-frequency capabilities. They provide a preamplified low-impedance output, simple cabling, and simple signal conditioning, and generally have the lowest overall system cost.Most important to the user are the performance and environmental specifications and the price. What's inside the box is irrelevant if the instrument meets the requirements of the application, but when adding to existing instrumentation it is important to be sure that the accelerometer is compatible with the signal conditioning. Each type of accelerometer requires a different type of signal conditioning.Accelerometer Types. The most common seismic transducers for shock and vibration measurements are:∙Piezoelectric (PE); high-impedance output∙Integral electronics piezoelectric (IEPE); low-impedance output∙Piezoresistive (PR); silicon strain gauge sensor∙Variable capacitance (VC); low-level, low-frequency∙Servo force balancePiezoelectric (PE) sensors use the piezoelectric effects of the sensing element(s) to produce a charge output. Because a PE sensor does not require an external power source for operation, it is considered self-generating. The "spring" sensing elements provide a given number of electrons proportional to the amount of applied stress (piezein is a Greek word meaning to squeeze). Many natural and man-made materials, mostly crystals or ceramics and a few polymers, display this characteristic. These materials have a regular crystalline molecular structure, with a net charge distribution that changes when strained.Piezoelectric materials may also have a dipole (which is the net separation of positive and negative charge along a particular crystal direction) when unstressed. In these materials, fields can be generated by deformation from stress or temperature, causing piezoelectric or pyroelectric output, respectively. The pyroelectric outputs can be very large unwanted signals, generally occurring over the long time periods associated with most temperature changes. Polymer PE materials have such high pyroelectric output that they were originally used as thermal detectors. There are three pyroelectric effects, which will be discussed later in detail.Charges are actually not "generated," but rather just displaced. (Like energy and momentum, charge is always conserved.) When an electric field is generated along the direction of the dipole, metallic electrodes on faces at the opposite extremes of the gradient produce mobile electrons that move from one face, through the signal conditioning, to the other side of the sensor to cancel the generated field. The quantity of electrons depends on the voltage created and the capacitance between the electrodes. A common unit of charge from a PE accelerometer is the picocoulomb, or 10-12 coulomb, which is something over 6 × 106 electrons.Choosing among the many types of PE materials entails a tradeoff among charge sensitivity, dielectric coefficient (which, with geometry, determines the capacitance), thermal coefficients, maximum temperature, frequency characteristics, and stability. The best S/N ratios generally come from the highest piezoelectric coefficients.Naturally occurring piezoelectric crystals such as tourmaline or quartz generally have low-charge sensitivity, about one-hundredth that of the more commonly used ferroelectric materials. (But these low-charge output materials are typically used in the voltage mode, which will be discussed later.) Allowing smaller size for a given sensitivity, ferroelectric materials are usually man-made ceramics in which the crystalline domains (i.e., regions in which dipoles are naturally aligned) are themselves aligned by a process of artificial polarization.Polarization usually occurs at temperatures considerably higher than operating temperatures to speed the process of alignment of the domains. Depolarization, or relaxation, can occur at lower temperatures, but at very much lower rates, and can also occur with applied voltages and preload pressures. Depolarization always results intemporary or permanent loss of sensitivity. Tourmaline, a natural crystal that does not undergo depolarization, is particularly useful at very high temperatures.Because they are self-generating, PE transducers cannot be used to measure steady-state accelerations or force, which would put a fixed amount of energy into the crystal (a one-way squeeze) and therefore a fixed number of electrons at the electrodes. Conventional voltage measurement would bleed electrons away, as does the sensor's internal resistance. (High temperature or humidity in the transducer would exacerbate the problem by reducing the resistance value.) Energy would be drained and the output would decay, despite the constant input acceleration/force.External measurement of PE transducer voltage output requires special attention to the cable's dynamic behavior as well as the input characteristics of the preamplifier. Since cable capacitance directly affects the signal amplitude, excessive movement of the cable during measurement can cause changes in its capacitance and should be avoided. Close attention should also be paid to the preamp's input impedance; this should be on the order of 1000 M or higher to ensure sufficient low-frequency response.In practice, a charge amplifier is normally used with a PE transducer.Instead of measuring voltage externally, a charge should be measured with a charge converter. It is ahigh-impedance op amp with a capacitor as its feedback. Its output is proportional to the charge at the input and the feedback capacitor, and is nearly unaffected by the input capacitance of the transducer or attached cables. The high-pass corner frequency is set by the feedback capacitor and resistor in a charge converter, and not the transducer characteristics. (The transducer resistance changes noise characteristics, not the frequency.) If time constants are long enough, the AC-coupled transducer will suffice for most vibration measurements.Perhaps the most important limitation of high-impedance output PE transducers is that they must be used with "noise-treated" cables; otherwise, motion in the cable can displace triboelectric charge, which adds to the charge measured by the charge converter. Triboelectric noise is a common source of error found in typical coaxial cables.Most PE transducers are extremely rugged. Each of the various shapes and sizes available comes with its own performance compromises. The most common types of this transducer are compression and shear designs. Shear design offers better isolation from environmental effects such as thermal transient and base strain, and is generally more expensive. Beam-type design, a variation of the compression design, is also quite popular due to its lower manufacturing cost. But beam design is generally more fragile and has limited bandwidth.Integral Electronics Piezoelectric (IEPE). Many piezoelectric accelerometers/force transducers include integral miniature hybrid amplifiers, which, among their other advantages, do not need noise-treated cable. Most require an external constant current power source. Both the input supply current and output signal are carried over the same two-wire cable. The low-impedance output of the IEPE design (see Figure 5) provides relative immunityto the effects of poor cable insulation resistance, triboelectric noise, and stray signal pickup.Output-to-weight ratio of IEPE is higher than with PE transducers. Additional functions can be incorporated into the electronics (see Figure 6), including filters, overload protection, and self-identification.Lower cost cable and conditioning can be used since the conditioning requirements are comparatively lax compared to PE or PR. The sensitivity of IEPE accelerometers/force transducers, in contrast to PR, is not significantly affected by supply changes. Instead, dynamic range, the total possible swing of the output voltage, is affected by bias and compliance voltages. Only with large variations in current supply would there be problems with frequency response when driving high-capacitance loads.A disadvantage of built-in electronics is that it generally limits the transducer to a narrower temperature range. In comparison with an identical transducer design that does not have internal electronics, thehigh-impedance version will always have a higher mean time between failures (MTBF) rating. In addition, the necessarily small size of the amplifier may preclude some of the desirable features offered by a full-blown laboratory amplifier, such as the ability to drive long cable. Slew limiting is therefore a concern with these transducers (some designs have relatively high output impedance) when driving long lines or other capacitive loads. The problem can be remedied by increasing the amount of drive current within the limit specified by the manufacturer.The circuits need not necessarily be charge converters because the capacitance due to leads between the sensor and the amplifier is small and well controlled. Quartz is used in the voltage mode, i.e., with source followers, because its small dielectric coefficient provides comparatively high voltage per unit charge. Voltage conversion also aids ferroelectric ceramics that have the sag in frequency response in charge mode due to their frequency-dependent dielectric coefficient. The amplitude frequency response in the voltage mode is quite flat.Piezoresistive. A PR accelerometer is a Wheatstone bridge of resistors incorporating one or more legs that change value when strained. Because the sensors are externally supplied with energy, the output can be meaningfully DC coupled to respond to steady-state conditions. Data on steady-state accelerations comes at a cost, however. The sensitivity of a bridge varies almost directly with the input excitation voltage, requiring a highly stable and quiet excitation supply .The output of a bridge configuration is the difference between the two output leads. A differential amplifier is required or, alternatively, both leads from the excitation must float to allow one of the output lines to be tied to ground. The differential configuration provides the advantage of common-mode rejection; that is to say, any noise signals picked up on the output lines, if equal, will be canceled by the subtraction in the amplifier.A cautionary note is in order here: With high-output PR transducers, there is a temptation to dispense with an amplifier and simply to connect the output leads directly to an oscilloscope. This will not work if both the scope and the excitation are single ended. Oscilloscopes often have single-ended input (the negative side of the input is ground). If the excitation is also grounded (with the excitation equal to ground), one leg of the bridge is shuntedand the entire excitation voltage is placed across that one leg of the bridge. If you are using AC coupling on the scope, you might misinterpret the reasonably shaped, but small and noisy, output.Most PR sensors use two or four active elements. Voltage output of a two-arm, or half-bridge, sensor is half that of a four-arm, or full bridge.Stability requirements for a PR transducer power supply and its conditioning are considerably tighter than they are for IEPE. Low-impedance PR transducers share the advantages of noise immunity provided by IEPE, although the output impedance of PR is often large enough that it cannot drive large capacitive loads. As is the case with an underdriven IEPE, the result is a low-pass filter on the output, limiting high-frequency response.The sensitivity of a strain gauge comes from both the elastic response of its structure and the resistivity of the material. Wire and thick or thin film resistors have low gauge factors; that is, the ratio of resistance change to the strain is small. Their response is dominated by the elastic response. They are effectively homogeneous blocks of material with resistivity of nearly constant value. As with any resistor, they have a value proportional to length and inversely proportional to cross-sectional area. If a conventional material is stretched, its width reduces while the length increases. Both effects increase resistance.The Poisson ratio defines the amount a lateral dimension is narrowed compared to the amount the longitudinal dimension is stretched. Given a Poisson ratio of 0.3 (a common value), the gauge factor would be 1.6; resistance would change 1.6 × more than it is strained. A typical gauge factor for metal strain gauges is ~2.The response of strain gauges with higher gauge factors is dominated by the piezoresistive effect, which is the change of resistivity with strain. Semiconductor materials exhibit this effect, which, like piezoelectricity, is strongly a function of crystal orientation. Like other semiconductor properties, it is also a strong function of dopant concentration and temperature. Gauge factors near 100 are common for silicon gauges, and, when combined with small size and the stress-concentrating geometries of anisotropically etched silicon, the efficiency of the silicon PR transducer is very impressive. The miniaturization allows natural frequencies >1 MHz in some PR shock accelerometers.Most contemporary PR sensors are manufactured from a single piece of silicon. In general, the advantages of sculpting the whole sensor from one homogeneous block of material are better stability, less thermal mismatch between parts, and higher reliability. Underdamped PR accelerometers tend to be less rugged than PE devices. Single-crystal silicon can have extraordinary yield strength, particularly with high strain rates, but it is a brittle material nonetheless. Internal friction in silicon is very low, so resonance amplification can be higher than for PE transducers. Both these features contribute to its comparative fragility, although if properly designed and installed they are used with regularity to measure shocks well above 100,000 g. They generally have wider bandwidths than PE transducers (comparing models of similar full-scale range), as well as smaller nonlinearities, zero shifting, and hysteresis characteristics. Because they have DC response, they are used when long-duration measurements are to be made.。
机械专业文献带翻译
机械专业文献带翻译Title: Research and Development of a Novel Mechanical Device for Automated Assembly of Small Parts。
Abstract:The assembly of small parts is a time-consuming and labor-intensive process, often requiring skilled workers to perform the task. In order to improve efficiency and reduce costs, a novel mechanical device for automated assembly of small parts has been developed. This device is capable of handling a variety of small parts with high precision and speed, and can significantly reduce the time and cost required for assembly.Introduction:The assembly of small parts is a critical process in many industries, including electronics, automotive, and medical device manufacturing. This process often requiresskilled workers to perform the task, which can be time-consuming and costly. In addition, human error can lead to defects and quality issues, further increasing costs and reducing efficiency.To address these challenges, a novel mechanical device for automated assembly of small parts has been developed. This device is capable of handling a variety of small parts with high precision and speed, and can significantly reduce the time and cost required for assembly.Design and Development:The mechanical device for automated assembly of small parts consists of several key components, including a feeder, a manipulator, and a control system. The feeder is responsible for delivering small parts to the manipulator, which then assembles the parts according to a predetermined pattern. The control system coordinates the movements of the feeder and manipulator, ensuring that the assembly process is carried out with high precision and speed.The design of the manipulator is particularly important, as it must be capable of handling a wide range of smallparts with varying shapes and sizes. The manipulatorconsists of a series of grippers and suction cups, whichcan be adjusted to accommodate different types of parts.The grippers and suction cups are controlled by a series of motors and sensors, which ensure that the parts are picked up and assembled accurately.Testing and Evaluation:The mechanical device for automated assembly of small parts has been tested extensively in a laboratory setting, and has demonstrated high levels of precision and speed.The device is capable of handling a wide range of small parts, including electronic components, screws, and bolts.In addition, the device has been shown to significantly reduce the time and cost required for assembly, compared to manual assembly methods.Future Directions:The mechanical device for automated assembly of small parts has significant potential for use in a variety of industries, including electronics, automotive, and medical device manufacturing. Further research and development is needed to optimize the design and performance of the device, and to explore its potential for use in new applications.Conclusion:The development of a novel mechanical device for automated assembly of small parts has the potential to revolutionize the assembly process in many industries. This device is capable of handling a wide range of small parts with high precision and speed, and can significantly reduce the time and cost required for assembly. Further research and development is needed to optimize the design and performance of the device, and to explore its potential for use in new applications.。
机械专业英语论文翻译
RisersRisers are designed and placed so as to ensure filling the cavity during solidification.They also act to relieve gas pressure in the mold and to reduce pressure on the lifting surfaces of the mold.The volume of metal in the riser should be sufficient to retain heat long enough to feed the shrinkage cavity and to equalize the temperature in the mold, avoiding casting strains.The riser requirements vary with the type of metal being poured.Gray cast iron, for example, needs less feeding than some alloys because a period of graphitization occurs during the final stages of solidification, which causes an expansion that tends to counteract the metal shrinkage.Many nonferrous metals require elaborate feeding that tends to counteract the casting.Two riser designs for the same casting are shown in Fig.7-4.Risers are placed near the heavy sections of the casting. The feed metal must be located above the highest point of the point of the casting.Chill BlocksChill blocks are metal blocks placed in the mold for localized heat dissipation.They may be placed at an intersection or joint where there is a comparatively large volume of metal to cool, thus relieving a hot spot or maintaining a more uniform cooling rate and better microstructure.They may also be placed at far surface of a mold, away from a riser or sprue.This will help the far end of the mold to freeze rapidly, promoting directional solidification.Chill blocks are also used at points where it is designable to have localized hardening, as in the case of bearings or wear surfaces.PaddingPadding consists of adding to or building up a section to obtain adequate feeding of isolated sections.Fig.7-4showed two methods of feeding the central and outside boss .Shown at (b) is the plan of using two risers and at (c) one riser with a pad. The second plan provides a yield of 45% of the metal poured, compared to 30% when two risers are used. The feeding distance to the central hub is 4.5t, where t= the thickness of the feed path. By rule of thumb, the total thickness of pad and castinuld not be less than one-fifth of the metal-feeding distance. This rule is not absolute but a good generalization.
机床——机械类外文文献翻译、中英文翻译
毕业设计(论文)外文资料翻译系部:专业:姓名:学号:外文出处:English For Electromechanical(用外文写)Engineering附件:1.外文资料翻译译文;2.外文原文。
附件1:外文资料翻译译文机床机床是用于切削金属的机器。
工业上使用的机床要数车床、钻床和铣床最为重要。
其它类型的金属切削机床在金属切削加工方面不及这三种机床应用广泛。
车床通常被称为所有类型机床的始祖。
为了进行车削,当工件旋转经过刀具时,车床用一把单刃刀具切除金属。
用车削可以加工各种圆柱型的工件,如:轴、齿轮坯、皮带轮和丝杠轴。
镗削加工可以用来扩大和精加工定位精度很高的孔。
钻削是由旋转的钻头完成的。
大多数金属的钻削由麻花钻来完成。
用来进行钻削加工的机床称为钻床。
铰孔和攻螺纹也归类为钻削过程。
铰孔是从已经钻好的孔上再切除少量的金属。
攻螺纹是在内孔上加工出螺纹,以使螺钉或螺栓旋进孔内。
铣削由旋转的、多切削刃的铣刀来完成。
铣刀有多种类型和尺寸。
有些铣刀只有两个切削刃,而有些则有多达三十或更多的切削刃。
铣刀根据使用的刀具不同能加工平面、斜面、沟槽、齿轮轮齿和其它外形轮廓。
牛头刨床和龙门刨床用单刃刀具来加工平面。
用牛头刨床进行加工时,刀具在机床上往复运动,而工件朝向刀具自动进给。
在用龙门刨床进行加工时,工件安装在工作台上,工作台往复经过刀具而切除金属。
工作台每完成一个行程刀具自动向工件进给一个小的进给量。
磨削利用磨粒来完成切削工作。
根据加工要求,磨削可分为精密磨削和非精密磨削。
精密磨削用于公差小和非常光洁的表面,非精密磨削用于在精度要求不高的地方切除多余的金属。
车床车床是用来从圆形工件表面切除金属的机床,工件安装在车床的两个顶尖之间,并绕顶尖轴线旋转。
车削工件时,车刀沿着工件的旋转轴线平行移动或与工件的旋转轴线成一斜角移动,将工件表面的金属切除。
车刀的这种位移称为进给。
车刀装夹在刀架上,刀架则固定在溜板上。
溜板是使刀具沿所需方向进行进给的机构。
机械专业毕业设计外文翻译相关外文文献
Fraunhofer-IBMT Technology Center Hialeah, 601 West 20 th Street, Hialeah, FL 33010, USA b TRS Ceramics, Inc, 2820 E. College Avenue, Suite J, State College, PA 16801, USA Received 28 January 2002; accepted 24 March 2002
* Corresponding author. Tel.: 1 1-305-925-1260; fax: 1 1-305-925-1269. E-mail addresses: epark@ (S.-E.E. Park), info@ (W. Hackenberger). 1359-0286 / 02 / $ – see front matter 2002 Elsevier Science Ltd. All rights reserved. PII: S1359-0286( 02 )00023-2
Fig. 1. Comparison of E-field induced strains for relaxor-PT single crystals versus various types of electroactive ceramics, (a) non-hysteretic strain behavior at E-fields before the E-field induced phase transition, and (b) strain behaviors associated with the E-field induced phase transition.
Current Opinion in Solid State and Materials Science 6 (2002) 11–18
机械设计制造及其自动化毕业论文中英文资料外文翻译
机械设计创造及其自动化毕业论文外文文献翻译INTEGRATION OF MACHINERY译文题目专业机械设计创造及其自动化外文资料翻译INTEGRATION OF MACHINERY(From ELECTRICAL AND MACHINERY INDUSTRY)ABSTRACTMachinery was the modern science and technology development inevitable result, this article has summarized the integration of machinery technology basic outline and the development background .Summarized the domestic and foreign integration of machinery technology present situation, has analyzed the integration of machinery technology trend of development.Key word: integration of machinery ,technology, present situation ,product t,echnique of manufacture ,trend of development0. Introduction modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation .In mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management systemof by machinery for the characteristic integration ofdevelopment phase.1. Integration of machinery outline integration of machinery is refers in the organization new owner function, the power function, in the information processing function and the control function introduces the electronic technology, unifies the system the mechanism and the computerization design and the software which constitutes always to call. The integration of machinery development also has become one to have until now own system new discipline, not only develops along with the science and technology, but also entrusts with the new content .But its basic characteristic may summarize is: The integration of machinery is embarks from the system viewpoint, synthesis community technologies and so on utilization mechanical technology, microelectronic technology, automatic control technology, computer technology, information technology, sensing observation and control technology, electric power electronic technology, connection technology, information conversion technology as well as software programming technology, according to the system function goal and the optimized organization goal, reasonable disposition and the layout various functions unit, in multi-purpose, high grade, redundant reliable, in the low energy consumption significance realize the specific function value, and causes the overall system optimization the systems engineering technology .From this produces functional system, then becomes an integration of machinery systematic or the integration of machinery product. Therefore, of coveringtechnology is based on the above community technology organic fusion one kind of comprehensive technology, but is not mechanical technical, the microelectronic technology as well as other new technical simple combination, pieces together .This is the integration of machinery and the machinery adds the machinery electrification which the electricity forms in the concept basic difference .The mechanical engineering technology has the merely technical to develop the machinery electrification, still was the traditional machinery, its main function still was replaces with the enlargement physical strength .But after develops the integration of machinery, micro electron installment besides may substitute for certain mechanical parts the original function, but also can entrust with many new functions,like the automatic detection, the automatic reduction information, demonstrate the record, the automatic control and the control automatic diagnosis and the protection automatically and so on .Not only namely the integration of machinery product is human's hand and body extending, human's sense organ and the brains look, has the intellectualized characteristic is the integration of machinery and the machinery electrification distinguishes in the function essence.2. Integration of machinery development condition integration of machinery development may divide into 3 stages roughly.20th century 60's before for the first stage, this stage is called the initial stage .In this time, the people determination not on own initiative uses the electronic technology the preliminary achievement to consummate the mechanical product the performance .Specially in Second World War period, the war has stimulated the mechanical product and the electronic technology union, these mechanical and electrical union military technology, postwar transfers civilly, to postwar economical restoration positive function .Developed and the development at that time generally speaking also is at the spontaneouscondition .Because at that time the electronic technology development not yet achieved certain level, mechanical technical and electronic technology union also not impossible widespread and thorough development, already developed the product was also unable to promote massively. The 20th century 70~80 ages for the second stage, may be called the vigorous development stage .This time, the computer technology, the control technology, the communication development, has laid the technology base for the integration of machinery development . Large-scale, ultra large scale integrated circuit and microcomputer swift and violent development, has provided the full material base for the integration of machinery development .This time characteristic is :①A mechatronics word first generally is accepted in Japan, probably obtains the quite widespread acknowledgment to 1980s last stages in the worldwide scale ;②The integration of machinery technology and the product obtained the enormous development ;③The various countries start to the integration of machinery technology and the product give the very big attention and the support. 1990s later periods, started the integration of machinery technology the new stagewhich makes great strides forward to the intellectualized direction, the integration of machinery enters the thorough development time .At the same time, optics, the communication and so on entered the integration of machinery, processes the technology also zhan to appear tiny in the integration of machinery the foot, appeared the light integration of machinery and the micro integration of machinery and so on the new branch; On the other hand to the integration of machinery system modeling design, the analysis and the integrated method, the integration of machinery discipline system and the trend of development has all conducted the thorough research .At the same time, because the hugeprogress which domains and so on artificial intelligence technology, neural network technology and optical fiber technology obtain, opened the development vast world for the integration of machinery technology .These research, will urge the integration of machinery further to establish the integrity the foundation and forms the integrity gradually the scientific system. Our country is only then starts from the beginning of 1980s in this aspect to study with the application .The State Councilsummary had considered fully on international the influence which and possibly brought from this about the integration of machinery technology developmenttrend .Many universities, colleges and institutes, the development facility and some large and middle scale enterprises have done the massive work to this technical development and the application, does not yield certain result, but and so on the advanced countries compared with Japan still has the suitable disparity.3. Integration of machinery trend of development integrations of machinery are the collection machinery, the electron, optics, the control, the computer, the information and so on the multi-disciplinary overlapping syntheses, its development and the progress rely on and promote the correlation technology development and the progress .Therefore, the integration of machinery main development direction is as follows:3.1 Intellectualized intellectualizations are 21st century integration of machinery technological development important development directions .Theartificial intelligence obtains day by day in the integration of machinery constructor's research takes, the robot and the numerical control engine bedis to the machine behavior description, is in the control theory foundation, the absorption artificial intelligence, the operations research, the computer science, the fuzzy mathematics, the psychology, the physiology and the chaos dynamics and so on the new thought, the new method, simulate the human intelligence, enable it to have abilities and so on judgment inference, logical thinking, independent decision-making, obtains the higher control goal in order to .Indeed, enable the integration of machinery product to have with the human identical intelligence, is not impossible, also is nonessential .But, the high performance, the high speed microprocessor enable the integration of machinery product to have preliminary intelligent or human's partial intelligences, then is completely possible and essential.In the modern manufacture process, the information has become the control manufacture industry the determining factor, moreover is the most active actuation factor .Enhances the manufacture system information-handling capacity to become the modern manufacture science development a key point .As a result of the manufacture system information organization and structure multi-level, makes the information the gain, the integration and the fusion presents draws up the character, information measure multi-dimensional, as well as information organization's multi-level .In the manufacture information structural model, manufacture information uniform restraint, dissemination processing and magnanimous data aspects and so on manufacture knowledge library management, all also wait for further break through.Each kind of artificial intelligence tool and the computation intelligence method promoted the manufacture intelligence development in the manufacture widespread application .A kind based on the biological evolution algorithm computation intelligent agent, in includes thescheduling problem in the combination optimization solution area of technology, receives the more and more universal attention, hopefully completes the combination optimization question when the manufacture the solution speed and the solution precision aspect breaks through the question scale in pairs the restriction .The manufacture intelligence also displays in: The intelligent dispatch, the intelligent design, the intelligent processing, the robot study, the intelligent control, the intelligent craft plan, the intelligent diagnosis and so on are various These question key breakthrough, may form the product innovation the basic research system. Between 2 modern mechanical engineering front science different science overlapping fusion will have the new science accumulation, the economical development and society's progress has had the new request and the expectation to the science and technology, thus will form the front science .The front science also has solved and between the solution scientific question border area .The front science has the obvious time domain, the domain and the dynamic characteristic .The project front science distinguished in the general basic science important characteristic is it has covered the key science and technology question which the project actual appeared.Manufacture system is a complex large-scale system, for satisfies the manufacture system agility, the fast response and fast reorganization ability, must profit from the information science, the life sciences and the social sciences and so on the multi-disciplinary research results, the exploration manufacture system new architecture, the manufacture pattern and the manufacture system effective operational mechanism .Makes the system optimization the organizational structure and the good movement condition is makes the system modeling , the simulation and the optimized essential target .Not only the manufacture system new architecture to makes the enterprise the agility and may reorganize ability to the demand response ability to have the vital significance, moreover to made the enterprise first floor production equipment the flexibility and may dynamic reorganization ability set a higher request .The biological manufacture view more and more many is introduced the manufacture system, satisfies the manufacture system new request.The study organizes and circulates method and technique of complicated system from the biological phenomenon, is a valid exit which will solve many hard nut to cracks that manufacturing industry face from now on currently .Imitating to living what manufacturing point is mimicry living creature organ of from the organization, from match more, from growth with from evolution etc. function structure and circulate mode of a kind of manufacturing system and manufacturing process.The manufacturing drives in the mechanism under, continuously by one's own perfect raise on organizing structure and circulating mode and thus to adapt the process of[with] ability for the environment .For from descend but the last product proceed together a design and make a craft rules the auto of the distance born, produce system of dynamic state reorganization and product and manufacturing the system tend automatically excellent provided theories foundation and carry out acondition .Imitate to living a manufacturing to belong to manufacturing science and life science of"the far good luck is miscellaneous to hand over", it will produce to the manufacturing industry for 21 centuries huge of influence .机电一体化摘要机电一体化是现代科学技术发展的必然结果,本文简述了机电一体化技术的基本概要和发展背景。
机械专业毕业设计--外文资料和翻译
Metal heat treatmentA, annealingIn front of the description lengba processing materials and softening plastic treatment methods, it has been used the word, the word annealing with similar meanings. The purpose is to reduce completely annealing, hardness, plastic, sometimes also increased to improve the cutting performance, high this steel is difficult to processing. This method is used to reduce heat stress, refined grains, improve the structure of the material.Annealing is not always can improve the cutting machining, cutting processing a word used to describe several factors, including material cutting when good finish (i.e. smaller surface roughness - the ability of the translator. When fully annealing, ordinary low hardness, low intensity of cutting resistance smaller, less, but usually due to the plasticity and toughness is too big to chip away when the surface of workpiece surface of workpiece surface quality, scratch, leads to poor cutting processing. For this kind of steel, annealing may not be the most appropriate treatment. Many of the most high and cutting steel processing usually can be greatly improved by annealing except in the soft, because of their condition, high hardness and strength for processing.And the annealing method is GongXi just slow to the steel wire, insulation above about for a period of time, make the same temperature uniformity, forming materials, then the austenitic or buried with furnace lime or other insulating materials in slow cooling. To precipitation of ferrite and pearlite bulky iron, steel in the soft, the strain of toughness and minimum, must slow cooling.Second, normalizingHow much is the fire of similar purposes, but not the annealing steel soft and fine pearlite state. Not bulky. Steel is refined grains, fire can release of stress, improve structural homogeneity and restore some plastic, high toughness. This method is often used to improve cutting machining, reduce stress, reduce part machining or limitation of deformation.Is the fire will chromatography method is GuoGongXiGang steel or slow heatedto Ac3 respectively, Accm line or on-line insulation for a period of time to form, and in the austenitic stationary air slow cooling. Should notice more, GongXi composition of carbon steel needs to be heated to Accm line above, not Ac1 line above the annealing. The purpose is in the process of austenitic to dissolve all cementite, thus to minimize the boundaries on hard and brittle iron carbon compounds, and get little grain of ferrite pearlite, minimum free cementite and freedom.Third, the ball annealingThrough the steel ball annealing can get minimum hardness and the biggest plastic, it can make the iron carbon compounds with small globular distribution in ferritic matrix. In order to make the ball easier small particles, usually for fire steel ball annealing. Ball annealing available in several different methods, but all the methods are needed in A1 line near (usually slightly low temperature preservation) for a long time, make the iron carbon compounds formed more stable, low level of small ball.Ball annealing method of the main objective is to improve the cutting processing, and drawing of hardened steel pretreatment, make it more uniform structure quenching. Because of the heat treatment for a long time, so the cost is higher than that of ball annealing is common or annealing.Four, steel sclerosisThe most hardened steel heat treatment method is based on the production of martensite high. Therefore, the first step to most other treatment with commonly used method -- austenitic. YaGongXiGang heated to Ac1 liquidus temperature, heat preservation, more about that temperature uniformly, austenitic evenly. GuoGongXiGang Ac1 above liquidus temperature preservation in steel, while about still remain iron carbon compounds.The second step is to avoid rapid cooling in the nose produces isothermal curve transformation pearlite. The cooling speed depends on the temperature and hardened steel quenching medium heat can be taken away from the surface of the ability of heat transfer and steel itself. Table 1-11 is some common medium and cooling method, cooling ability of the sequence.High temperature gradient produces high stress, deformation and cracking causes,so only in the very need to produce quenching specific structures are used. When the quenching heat uniform, care must be taken to reduce the heat stress diffusion. For example, a thin stick to end its vertical quenching, is inserted into the cooling medium, so whole section and temperature changes. If the shape of a side of the workpiece cooling, and on the other side of the earlier than size change is likely to cause high stress, produce plastic flow and permanent deformation.With several special quenching method can reduce stress, deformation and cracking quenching decreases. One called hierarchical quenching, the method is: will the austenitic steel in temperature is higher than that of martensite transformation temperature (Ms), salt bath time until the temperature uniformity, at the beginning of forming bainite, then put before air cooling, heat generated from the start when the same hardware quenching cracking, martensite and warpage cause of high thermal stress or eliminate stress have been quenched.In a similar method of temperature, then, is called the isothermal quenching (austenitic steel in salt bath), keep for a long time, the result is formed with the isothermal bainite. Bainite structure in the same ingredients as the formation of martensite hard, but in normal hardened steel, reduce the heat shock, by further processing, unnecessary in high hardness can be obtained when good impact toughness.Five, temperingTo adjust hardened steel used the third step is often backfire. Besides the isothermal quenching steel quenching condition usually used in most all can use in production. To produce martensite steel to quench make hard, macro and micro stress, stress, low plasticity materials. To reduce the harm that can be heated to steel again by low-temperature shift (A1) below a certain temperature. Hardened steel structure change of tempering time and temperature is the function of temperature, which is the most important. Must be hardened piece.it is emphasized, method, but the reverse is true. Steel is tempered by heat treatment of hardened steel, through the tempering of heating, to release stress again, soften and improve plastic.The structural change and tempering causes change depending on performance of the heating temperature steel back. The higher the temperature, the temperatureeffect, so the choice is often sacrificed for the hardness and strength plasticity and toughness. Again, to quench heating to influence of carbon-steel, in between, structure, changes will occur in the above, the structure and properties of the significant changes. In the next time the temperature of the A1 heat will produce and process of ball annealing of similar structures.In industry, usually avoid to scope, because the tempering within the scope of tempering steel often produced unexplained brittleness or plastic loss. Some alloy in to scope, also can produce "temper brittleness, especially from" (or by) the temperature range slow cooling will appear. When these steel heat temper, they must usually heated to rapid cooling and above. Of course, from the temperature of cold won't produce sclerosis, fast because no austenitic.金属热处理一、退火在前面描述冷拔加工材料的软化并重新获得塑性的热处理方法时,就已使用退火这个词,该词具有相似的意义。
机械制造工艺外文文献翻译、中英文翻译、外文翻译
中国地质大学长城学院本科毕业设计外文资料翻译系别:工程技术系专业:机械设计制造及其自动化姓名:侯亮学号:052115072015年 4 月 3 日外文资料翻译原文Introduction of MachiningHave a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the work piece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.Strict precision and good surface finish, machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.Primary Cutting ParametersCutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct.Cutting speed is the cutting edge of work piece surface rate, it is inches per minute toshow. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate.Progressive Tool to speed is cut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to.Depth of penetration of a cutting tool -- to inches dollars -- is the tool to the work piece distance. Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishing, deeper penetration of a cutting tool depth.Rough machining and finishing machiningThere are two kinds of cuts in machine- shop work called, respectively, the "roughing cut" and the "finishing cut". When a piece is "roughed out", it is quite near the shape and size required, but enough metal has been left on the surface to finish smooth and to exact size." Generally speaking, bars of steel, forging, castings, etc. are machined to the required shape and size with only one roughing and one finishing cut. Sometimes, however, certain portions of a piece may require more than one roughing cut. Also, in some jobs, for example, when great accuracy is not needed, or when a comparatively small amount of metal must be removed, a finishing cut may be all that is required. The roughing cut, to remove the greater part of the excess material, should be reasonably heavy, that is, all the machine, or cutting tool, or work, or all three, will stand. So the machinist’s purpose is to remove the excess stock as fast as he can without leaving, at the same time, a surface too torn and rough, without bending the piece if it is slender, and without spoiling the centers. The finishing cut, to make the work smooth and accurate, is a finer cut. The emphasis here is refinement - very sharp tool, comparatively little metal removed, and a higher degree of accuracy in measurement. Whether roughing or finishing, the machinist must set the machine for the given job. He must consider the size and shape of the work and the kind of material, also the kind of tool used and the nature of the cut to be made, then he proceeds to set the machine for the correct speed and feed and to set the tool to take the depth of cut desired.Automatic Fixture Design外文资料翻译译文机械制造工艺机械加工是所有制造过程中最普遍使用的而且是最重要的方法。
- 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
利用CAD / CAM/ CAE系统开发操纵机器人H.S.李*,S.E.张华为技术学院,电力机械工程,云林,台湾,中国摘要在这项研究中,需要开发用于机器人操作臂的CAD/CAE/CAM集成系统。
通过变换矩阵,利用D-H坐标系变换方法对机器人的位姿进行分析,我们使用MATAB软件对其进行计算。
一般来说,利用PRO/E对机械臂的参数进行实体化建模,用Pro / Mechanical软体模拟动态仿真和工作空间,MasterCAM用来实现切削模拟仿真,而最终的模型用CNC数控铣床制造出来。
这样,一个用于机器人操作臂的CAD/CAE/CAM集成系统便开发出来了。
我们用一个范例来验证这种设计,分析以及制造的结果的正确性。
该集成系统不仅促进机器人的生产自动化功能,而且还简化了机械臂的CAD / CAE / CAM的分析过程。
这种集成系统是用于开发一个实用的计算机辅助机构设计课程的教学辅助工具。
©2003由Elsevier B.V.出版关键词:CAD / CAE/ CAM;机械臂;Denavit,Hartenberg坐标系变换引言许多研究已涉及到的CAD / CAE/ CAM集成系统的原理。
吕[1]讨论了平面五杆受电弓的运动学分析并设计制造了基于此弓的机械手。
通过研究五杆受电弓的运动性能,设计出一款简单的控制器来对机械手进行控制。
李某和陈某[2]描述了一个自动升降轮椅固定装置内的全尺寸货车的开发。
开发的过程中,包括机制的概念设计,运动仿真,工程分析,原型开发和测试。
周[3]使用参数化CAD系统的实体模型表达设计理念。
首先开发的是模具,其次是基于CAM系统的模型。
通过与产业界的合作,对试模调整,粉末形成,烧结,烧结后处理在专业的粉末冶金工厂进行了实验。
徐[4]在UG2通用CAD / CAM系统的基础上通过将注塑模具的CAD/CAM软件与注塑模具CAE软件集成建立了一个注塑用CAD / CAE/ CAM系统。
现在,许多研究已经涉及到了机器人与网络控制的原理。
黎[5]使用交互式菜单驱动机械手的运动学和逆运动学,学习如何使变换矩阵操纵友好的方法来开发计算机辅助教学软件。
黄等[6] 通过互联网得的远程计算控制功能提出了一种五轴联动机器人交流伺服与TCP/ IP协议。
在机器人的运动期间,通过配备在实验室服务器上的CCD相机可以在主页上显示出来机器人的运动轨迹。
远程计算机可以通过浏览器远程监控机器人的运动。
为了满足并行工程的要求,我们使用的D-H的坐标变换方法进行机器人的位置分析;导入设计,分析和制造模拟实际的力学模型;制造机器人样机;以及提供一个用于机器人设计与分析的综合性网站。
本文不仅可以促进机械臂自动化功能,简化机器人的设计,分析和制造工艺,而且还可以作为教育用途的补充工具,用于大专计算机辅助机制的设计课程。
2系统分析示例系统的程序如下;1)计算机辅助设计用D-H坐标建立法来分析机器人的位姿,用MATLAB软件对其进行计算。
2)计算机辅助绘图利用Pro / ENGINEER的参数化设计的概念和统一的数据库,绘制3D零件图及组装机器人的实体模型。
3)计算机辅助分析为了评估通过虚拟机器人样机的机器人设计,装配实体模型转移到Pro / Mechanica软体(与Pro / ENGINEER系统集成)。
材料性能,约束和驱动程序被应用到模型上去模拟工作空间。
4)计算机辅助制造为了实现利用Mastercam的模拟切割,二维工程绘图档案应转移成舸文件,选择轮廓形成链,定义切削参数,生成以及验证刀具路径,最后,转换数控代码,将DNC与CNC数控铣床连接起来,制造机器人样机图1显示了上述系统结构。
在本节中,主要研究空间机械臂的运动学分析,如图2.使用本节中的理论研究,可以得到机器人的夹持装置的位置。
利用D-H坐标转置定义[7],(01)T表示将坐标系S1(X1, Y1,Z1)中的点变换到坐标系S0(X0, Y0,Z0)中去。
基准坐标系中夹持位置的描述可以用一连串的依次相乘的矩阵来描述05T = 01T 12T23T34T 45T 。
在基准坐标系S0下夹持位置就可以通过变换矩阵05T来变换到坐标系s5当中去。
变换矩阵如下:01T = Rot(Z, θ1) Trans(0, 0, d1) Rot(X,−90◦)cθ1 –sθ 1 0 0= sθ1 cθ0 00 01 00 00 11 0 0 00 1 0 00 0 1 d10 0 0 1=12T = Rot(Z, θ2) Trans(a2, 0, 0)1 0 0 00 0 1 00 −1 0 0cθ1 0 −sθ1sθ1 0 cθ1= =23T = Rot (Z, θ3) Trans (a 3, 0, 0) Rot (Y, 90◦) = X=34T = Rot (Z, θ4) Trans (0, 0, a 4) Rot (Y,−90◦)c θ2 −s θ2 0s θ2 c θ20 01 0 0 a2 0 1 0 0 0 0 1 0 0 0 0 1c θ2 −s θ2 0 a 2c θ2s θ2 c θ2 0 a 2s θ20 0c θ3 −s θ3 0s θ3 c θ30 01 0 0 a 3 0 1 0 0 0 0 1 0 0 0 0 10 0 1 0 0 1 0 0 −1 0 0 0 0 0 0 10 −s θ3 c θ3 a 3c θ3 0 c θ3 s θ3 a 3s θ3 −1 0 0 0 0 0 0 1=x = 45T = Rot(Z, θ5) Trans(a5, 0, 0)=x=cθ4 −sθ4 0sθ4 cθ40 01 0 0 00 1 0 00 0 1 a40 0 0 10 0 −1 00 1 0 01 0 0 00 0 0 10 −sθ4 −cθ4 00 cθ4 −sθ4 01 0 0 a40 0 0 1cθ5 −sθ5 0sθ5 cθ50 01 0 0 a50 1 0 00 0 1 00 0 0 1cθ5 −sθ5 0a5cθ5sθ5 cθ5 0a5sθ505T = 01T 12T 23T 34T 45T根据变换矩阵,我们用Matlab来计算机器人的位置并进行分析。
当θ1 = 0◦(fixed),θ2 = 25◦, θ3 = 25◦, θ4 = 45◦, θ5 = 5◦时,夹持装置的位置如图3所示3.2 样机的制造实体建模技术不仅可以极大地减少开发周期,而且可以有效的提高工业产品的制造精度与质量。
为了建立如图2所示的空间机器人的虚拟样机,我们一般使用PRO/E对各个部件进行草绘,并机械手的各个部件参数化模型进行装配。
图4 展示出了机械手实体模型的爆炸装配图。
图3。
夹持装置的位置图4。
爆炸装配图实体模型图5。
机器人运动学约束模型。
图6 工作空间图7。
手臂摆动刀具路径模拟。
图8。
摇臂切削仿真。
3.22 运动学分析为了在实际制造之前能够准确的预测机器人的运动学分析结果,我们通常使用PRO/MECANICA软件对机器人的装配模型进行定义来完成机械手的运动学约束模型。
定义的内容包括:坐标系的定义(如图2所示),材料的性能(定义为中密度聚乙烯)图9 驱动机器人图10 实例驱动器(定义振幅,周期,相位和偏移),约束(定义为旋转副),完整的机器人运动学约束模型,动态模拟与工作空间,图5 展示出了机器人的运动约束模型,图6 展示出了机器人的工作空间。
3.23 制造过程为了完成机械臂的规划过程,我们需要把2D的DXF文件转换成3D文件。
为了用MASTERCAM完成切削仿真,、我们需定义切削参数(如等高深度,刀具直径,主轴转速,进给速度,深度切割,直径偏移),刀具路径NC代码的生成和转化。
图7显示了振荡刀具路径模拟。
在完成数控代码的转换后,利用数控机床完成机器人样机的制造。
图8显示了摇臂切削仿真。
如图9 所示,完成了装有齿轮,步进电机,89C51微处理器的机器人完成了。
4.实例展示计算机网络的重要性和优势正在逐渐被认识到。
设计,分析和制造公司已经着手于利用更多的与网络关联的技术来支持他们的商业操作。
为了整合浏览器上的机器人设计与分析的结果,我们使用FrontPage来超链接的动态模拟图像,位置分析,工作空间。
这个实例在网络上可以获取。
网址为.tw/∼jennifer/robot1/.图10 展示出了实例模型的框架结构。
机器人的设计参数如下:d1 = 360 mm, a2 = 200 mm, a3 = 300 mm, a4 = 200 mm,a5 = 150 mm. 运动角度范围:θ1 = 0◦(固定), θ2 = 0–210◦, θ3 = 0–210◦, θ4 = 0–360◦, θ5 = 0–45◦.5.总结将FrontPage,MATLAB,Pro / E和Pro / Mechanica软体相结合,即可开发出一个用于机械手的CAD/CAE/CAM集成系统,该系统不仅促进机器人的生产自动化功能,但也简化了机械臂的CAD / CAE / CAM的过程。
这种集成系统还可用于开发实用的计算机辅助机制设计课程的教学辅助工具。
6.参考文献1)[1] D.M.陆,受电弓的运动学设计及其应用制造机械臂,J. TECHNOL。
15(1)(2000)149-155。
2)M.Y.李,S.H.陈,设计和开发的一个自动化轮椅升降装置,研究TECHNOL。
16(1)(2001)45-50。
3)M.柔,自动化设计和制造的金属研究和陶瓷粉的加工产品,研究TECHNOL。
15(3)(2000)463-468(中国)。
4)徐华,王华,R.Q.张旗张,系统集成注塑模具CAD/ CAE/ CAM的研究,上海交通大学。
32(1)(1998)26-29(中国)。
5)Y.S.丽,计算机辅助教学软件的发展机械手的运动学和反向运动学,1991年3月22日至23日,第六次会议关于技术和职业教育,台北,第20234-20239页。
6)S.A.公司黄,M.R.程,文学硕士KER,C.C.罗兆焦耳,吴,互联网五轴交流伺服机器人,遥控的自动化技术的第五次国际会议上,1998年7月20-22日,台北,第[B2-2]1-6。
7)J. Denavit,R.S.hartenberg,基于矩阵的低副机构的旋转运动学ASME研究APP机械22(1955)215。