自动化生产线-外文翻译

1、精品English Translation MaterialTransfer MachineThe highest degree of automation with special-purpose, multifunction machines is achieved by using transfer machines. Transfer machine are essentially a combination of individual workstations arranged in the required sequence, connected by work transfer

2、devices, and integrated with interlocked controls. Workplaces are automatically transferred between the stations, which are equipped with horizontal, vertical, or angular units to perform machining , gaging ,workplace repositioning, assembling, washing, or other operation.The two major classes oftra

3、nsfer machines are rotary and in-line types.An important advantage of transfer machines is that they permit the maximum number of operations to be performed simultaneously. There is relatively no limitation on the number of workplace surface or planes that can be machined, since devices can be inter

4、posed in transfer machines at practically any point for inverting, rotating, or orienting the workplace, so as to complete the machining operations. Work repositioning also minimizes the need for angular machining heads and allows operations to be performed in optimum time. Complete-可编辑-精品processing

5、 from rough casting or forging to finished parts is often possible.One or more finished parts are produced on a transfer machine with each index of the transfer system that moves the parts from stations to stations. Production efficiencies of such machines generally range from 50% for a machine vari

6、ety of different parts to 85% for a machine producing one part, in high production, depending upon the workplace and how the machine is operated(material handling method, maintenance procedures, etc. )All types of machining operations, such as drilling, tapping, reaming, boring, and milling, are eco

7、nomically combined on transfer machines. Lathe-type operations such as turning and facing are also being performed on in-line transfer machine, with the workplace being rotated in selected machining stations. Turning operations are performed in lathe-type segments in which toolholders are fed on sli

8、des mounted on tunnel-type bridge units. Workplace are located on centers and rotated by chucks at each turning station. Turning stations with CNC are available for use on in-line transfer machine. The CNC units allow the machine cycles to be easily altered to accommodate changes in workplace design

9、 and can also be used for automatic tool adjustments.Maximum production economy on transfer lines is often achieved by-可编辑-精品assembling parts to the workplaces during their movement through the machine. such items as bushings, seals, welch plugs, and heat tubes can be assembled and then machine or t

10、ested during the transfer machining sequence. Automatic nut torquing following the application of part subassemblies can also be carried out.Gundrilling or reaming on transfer machines is an ideal application provided that proper machining units are employed and good bushing practices are followed.

11、Contour boring and turning of spherical seats and other surface can be done with tracer-controlled single-point inserts, thus eliminating the need for costly special form tools. In-process gaging of reamed or bored holes and automatic tool setting are done on transfer machines to maintain close tole

12、rances.Less conventional operations sometimes performed on transfer machines include grinding, induction heating of ring gears for shrink-fit pressing on flywheels, induction hardening of valve seats, deep rolling to apply compressive preloads, and burnishing.Transfer machines have long been used in

13、 the automotive industry for production rates with a minimum of manual part handling. In addition to decreasing labor requirements, such machines ensure consistently uniform, high-quality parts at lower cost. They are no longer confined just to rough machining and now often eliminate the need for su

14、bsequent operations such as grinding and honing.-可编辑-精品More recently, there has been an increasing demand for transfer machines to handle lower volumes of similar or even different parts in smaller sizes, with means for quick changeover between production runs.Built-in flexibility, the ability to re

15、arrange and interchange machine units, and the provision of idle stations increases the cost of any transfer machine,but such feature are economicallyfeasible when productredesigns are common. Many such machines are now being used in nonautomotive applications for lower production requirements.Speci

16、al feature now available to reduce the time required for part changeover include standardized dimensions, modular construction, interchangeable fixtures mounted on master pallets that remain on the machine, interchangeable fixture components, the ability to lock out certain stations for different pa

17、rts by means of selector switches, and programmablecontrollers.Product designis also important,andcommon transfer and clamping surfaces should be provided on different parts whenever possible.Programmable Logic ControllersA programmable logic controller (PLC) is a solid-state device used to control

18、machine motion or process operation by means of a stored program. The PLC sends output control signals output and receive input signals through input/output (I/O) devices. A PLC controls output in-可编辑-精品response to stimuli at the inputs according to the logic prescribed by thestored program. The inp

19、uts are made up of limit switches, pushbuttons, thumbwheels, switches, pulses, analog signal, ASCII serial data, and binary or BCD data from absolute position encoders. The output are voltage or current level to drive end devices such as solenoids, motor starters, relays, lights, and so on. Other ou

20、tput device include analog devices, digital BCD displays, ASCII compatible devices, servo variable-speed drives, and even computers.Programmablecontrollers were developed (circa in 1968) whenGeneral MotorsCorps, and other automobile manufacturers wereexperimenting to see if there might be an alterna

21、tiveto scrapping alltheir hardwired control panel of machine tools and other production equipmentduringa modelchangeover. This annual traditionwasnecessary because rewritingof the panels was more expensive thanbuying new ones.The automotive companies approached a number of control equipment manufact

22、urers and asked them to develop a control systemthat would have a longer productive life without major rewriting, but would still be understandable to and repairable by the plant personnel.The new product was named a“ programmable controller” .The processor part of the PLC contains a central process

23、ing unit andmemory. The central processing unit (CPU) is the“traffic direction-可编辑-精品the processor, the memory stores information. Coming into the processor are the electrical signals from the input devices, as conditioned by the input module to voltage levels acceptable to processor logic. The proc

24、essor scans the state of I/O and updates outputs stored in the memory of the PLC. For example, the processor may be programmed so that if an input connected to a limit switch is true (limit switch closed), then a corresponding output wired to an output module is to be energized. This processor remem

25、bers this command through its memory and compares on each scan to see if that limit switch is, in fact, closed. If it is closed ,the processor energizes the solenoid by turning on the output module.The output device, such as a solenoid or motor starter, is wired to an output module s terminal, and i

26、t receives its shift signal from the processor, in effect, the processor is performing a long and complicated series of logic decisions. The PLC performs such decisions sequentially and in according with the stored program. Similarly, analog I/O allows the processor to make decisions based on the ma

27、gnitude of a signal, rather than just if it is on or off. For example, the processor may be programmed to increase or decrease the steam flow to a boiler (analog output) based on a comparison of the actual temperature in the boiler (analog input ) This is often performed by utilizing the built-in PI

28、D (proportional, integral, derivative) capabilities of the processor.-可编辑-精品Because a PLC is“ software based ” , its control logic functions can bechanged by reprogramming its memory. Keyboard programming devices facilitate entry of the revised program, which can be design to cause an existing machi

29、ne or process to operate in a different sequence or to different level of, or combinations of stimuli. Hardware modifications are needed only if additional, changed, or relocated input/output device are involved.Automated AssemblyAssembly in the manifacturing process consists of putting together all

30、 the component parts and sub-assemblies of a given product, fastening, performing inspections and function tests, labeling, separating good assembly from bad, and packaging and or preparing them for final use.Assembly is unique compared to the methods of manufacturing such as machining, grinding, an

31、d welding in that most of these processes invovle only a few disciplines and possibly only one. Most of these nonassembly operations cannot be performed weithout the aid of equipment; thus the development of automatic methods has been necessary rather than optional. Assembly, on the other hand, may

32、involve in one machine many of the fastening methods,such as riveting, welding, screwdriving,and adhesive application,as well as automatic parts seletion, proding, gaging, functional testing, labeling,and packaging. The state of the art in -可编辑-精品assembly operations has not reached the level of stan

33、dardization; much manual work is stillbeing performed in this area.Assembly has traditionally been one of the highest areas of direct labor costs. In some cases, assembly accounts for 50% or more of manufacturing csosts and typically 20% 50%. However, closer cooperation between design and manufactur

34、ing engineers has resulted in reducing and in a few cases eliminating altogether the need for assembly. When asssembly is required, improved design or products has simplified automated (semiautomatic or automatic) assembly.Considerations for Automated AssemblyBefore automated assembly is adopted, se

35、veral factors should be considerd.These include practicalityof the process for automation,simulation for economic considerations and justification,managementinvolvement, and labor relations.Determining the practicality of automated assembly required careful evaluation of the following:a)The number o

36、f parts in assembly.b)Design of the parts with respect to producibility, assembility, automatic handling, and testability (materials, forms, dimensional tolerances, and weights).c)Quality of parts to be assembled. Out-of-tolerance or defective parts can cause production losses and increase costs bec

37、ause of-可编辑-精品stoppages.d)Availablity of qualiyied, technically competent personal to be responsible for equipment operation.e) Total production and production-rate requipments.Product variations and frequency of design changes.f)Joining methods required.g)Assembly times and costs.h)Assembly lines o

38、r system configuration, using simulation, includingmaterial handling.译文1.自动生产线使用自动生产线可以利用专用、多功能机床来实现最大程度的自动化。自 动生产线实质是那些由工件传送装置连接起来的按所需顺序布置的单个工位的 组合，并且通过连锁控制集成为一体。工件在工位间被自动传送，每个工位都装 配有用于加工、测量、工件再定位、组装、清洗或其他操作的卧式、立式及倾斜 式设备。自动生产线的两大主要类别上旋转式和直列式。自动生产线的一个显著优点是它们允许同时完成大量的操作。相对来说，对机加工工件表面或平面的数量没有限制，因为装置可介

39、入自动生产线，实际上在 任意位置能使工件翻转、旋转或定向以便完成加工操作。工件重定位也使倾斜主 轴箱的数目减至最小，使操作在最佳时间完成。经常可进行从原始铸件或锻件到 成品件的完整加工。一个或多个成品件在一条带有每个传输系统标志的自动生产线上生产，传输系统使部件从一个工位运动到另一个工位。这类生产线的生产效率通常为50%85% ,由一条生产线生产各式各样部件时为 50% ,由一条生产线大批量 生产一个部件时达85%,这取决于工件和如何操作自动生产线（材料处理方法、 维护程序等。-可编辑-精品所有类型的机加工操作，如钻削、攻丝、较削、链削和铳削，在自动生产线 上被经济地组合在一起。诸如车削和表面

40、加工的车床式操作也在直列式自动生产 线上完成，工件在选择的机加工工位上旋转。 车削操作在机床部件完成，多刀架 通过安装在隧道式桥形装置上的滑轨进给。 工件定位在中心位置，由在每个车削 工位上的卡盘带动旋转。直列式自动生产线上 CNC的车削工位可供使用。CNC 装置允许我们很容易地改变机器工作周期以适应工件设计的改变而且用于调整 自动刀具。当工件在传送机上移动时通过将零件组装到工件上，经常可以获得连续生 产线上最大的生产经济效益。在传送加工过程中，能够对诸如轴衬、密封垫、威 尔士衬套和保温管等零件进行组装、机加工或测试。完成部件局部装配后也可进 行自动螺帽扭转。如果能使用合适的机加工装置并随后进

41、行良好的操作， 在自动生产线上进行 深钻孔或较削是一项理想的应用。球面座和其它表面的仿形链削和车削可用仿形 控制单点进入工件完成，因此取消了昂贵的专用成形刀具。 对较孔或链孔的测量 以及自动刀具的调整是在自动生产线上进行的，以保持精确的公差。有时在自动生产线上进行的非常规加工包括磨削、 环形齿轮的感应加热冷缩 配合压在飞轮上、阀座的感应淬火、深度辗压以施加预压载荷和抛光。自动生产线很早就用于汽车工业高效率得生产相同部件，手工零件加工量极少。除了减少劳动力需求外，这种生产线能保证低成本生产标准始终如一的、高质量零件。它们不再局限于粗加工，现在已经常取消了诸如抛光和搪磨这样的后 来工序。目前，对自

42、动生产线的需求越来越多，用来处理少量的小尺寸的相似的或甚 至不同的零件，用于生产经营的快速转换。内置柔性，即重新布置和互换机加工 设备的能力，以及提供空转工位增加了每个自动生产线的成本，但是在经常重新设计产品的情况下这些特性是经济可行的。现在许多这样的生产线已用在非汽车 领域里来满足少量的生产要求。现在用于减少零件更换时间的特殊性能包括标准尺寸、模块结构、安装在自 动生产线主托架上的互换性夹具、可互换性的夹具零件、借助选择开关将不同的 部件锁定在具体工位上的能力和可编程控制器。产品设计也很重要，如可能在不 同的零件上应提供常见的移动和夹紧用的表面。2,可编程序逻辑控制器-可编辑-精品可编程逻辑

43、控制器（PLC）是一种固态电子装置，它利用已存入的程序来控 制机器的运动或工艺的工序。PLC通过输入/输出（I/O）装置信号发出控制信号 和接受输入信号。PLC依据以存入程序所规定的逻辑控制输出装置响应的激励。 输入装置由限位开关、按钮、手轮、开关、脉冲、模拟信号、ASCII系列数据和来自于绝对位置解码的二进制或 BCD数据组成。输出的是驱动电磁线圈、电动 起动机、继电器、指示灯等设备的电压或电流电平。其他输出装置包括模拟装置、 数字BCD显示、ASCII兼容装置、伺服变速驱动器、甚至计算机。当通用汽车公司和其他制造商们正在试验看能否有另一种方法来销毁型号 转变过程中机床的所有布线控制面板和其他生产设备时，PLC被研制成了（大约在1968年）。这种年度厉行工作是必要的，因为控制面板的重新布线比购