自动化生产线

1、English Translation Material1. Tran sferMach ineThe highest degree of automati on with special-purpose, multif un cti on mach in esis achievedby using tran sfer mach in es.Tra nsfer mach ine are esse ntially a comb in atio n of in dividual workstatio ns arran ged in the required seque nce,c onn ecte

2、d by work tran sfer devices, and in tegrated with in terlocked con trols. Workplaces are automatically tran sferred betwee nthe stati ons, which are equipped with horiz on tal, vertical, or angular units to perform machining , gaging ,workplace repositioning, assembling,washing, or other operation.

3、The two major classes of transfer 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 planesthat can be machined,

4、 since devicesca n be in terposed in tran sfer mach in esat practically any point for inverting, rotating, or orienting the workplace, so as to complete the machining operations. Work repositi oning also mini mizes the n eed for an gular mach ining heads and allows operations to be performed in opti

5、mum time. Complete processing from rough castingor forging to finished partsis often possible.One or more finished parts are produced on a transfer machinewith eachindex of the transfer system that moves the parts from stations to stations. Production efficie ncies of such mach ines gen erally range

6、 from 50% for a machi ne variety of differe nt parts to 85% for a mach ine produc ing one part, in high product ion, depending upon the workplace and how the machine is operated(material handling method, maintenan ceprocedures,etc.)All types of machining operations, such as drilling, tapping, reamin

7、g, boring, and milling, are economically combined on transfer machines.Lathe-type operations such as turning and facing are also being performed on in-line transfer machine, with the workplace bein g rotated i n selected machining stations. Turning operations are performed in lathe-type segments in

8、which toolholders are fed on slides 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 mach ine cycles to be easily altered to accommo

9、datecha nges in workplace desig nand can also beusedfor automatictool adjustments.Maximum product ion economyon tran sfer lines is ofte n achievedby assembli ng parts to the workplaces during their movement through the machine. such items as bushi ngs, seals,welch plugs, and heat tubes can be assemb

10、leda nd the n machi neor tested during the transfer machining sequence.Automatic nut torquing following the application of part subassembliescan alsobecarried out.Gun drilli ng or ream ing on tran sfer mach in esis an ideal applicati on provided that proper machining units are employed and good bush

11、ing practices are followed. Con tour bori ng and turning of spherical seats and other surface can be done with tracer-c on trolled sin gle-po int in serts, thus elim in at ing the n eed for costly special form tools. In-process gaging of reamedor bored holes and automatic tool setting are done on tr

12、an sfermachi nesto main tai n closetolera nces.Less conventional operations sometimes performed on transfer machines include grinding, in duct ion heati ng of ring gears for shri nk-fit press ing on flywheels, in duct ion harde nin g of valve seats, deep rolli ng to apply compressive preloads, and b

13、ur nishing.Tran sfer machi neshave long bee nu sed in the automotive in dustry for product ion rates with a minimum of manual part handling. In addition to decreasing labor requireme nts,such mach in ese nsure con siste ntly uniform, high-quality parts at lower cost. They are no Ion ger confined jus

14、t to rough mach ining and now ofte n elim in ate the needfor subsequent operationssuch asgrinding and honing.More rece ntly, there has bee n an in creas ing dema nd for tran sfer machi nes to han dle lower volumes of similar or eve n differe nt parts in smaller sizes, with means for quick cha ngeove

15、r betwee n product ion runs. Built-in flexibility, the ability to rearra ngea nd in tercha nge machi neun its, and the provisi on of idle stati ons in creases the cost of any transfer machine, but such feature are economically feasible when product redesig ns are com mon. Many such mach ines are now

16、 being used in non automotive applicati on sfor lower product ion requireme nts.Special 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, intercha

17、ngeable fixture components,the ability to lock out certain stations for different parts by means of selector switches, and programmable controllers. Product design is also important, and com mon tran sfer and clamp ing surfaces should be provided on differe nt parts whe never possible.2. Programmabl

18、eLogic Con trollersA programmable logic controller (PLC) is a solid-state device used to control mach ine motio n or process operati on by mean sof a stored program. The PLC sends output con trol sig nals output and receive in put sig nals through in put/output (I/O) devices. A PLC con trols output

19、in resp onseto stimuli at the in puts accord ing to the logic prescribed by the stored program. The in puts are made up of limit switches, pushbutt on s, thumbwheels, switches, pulses, an alog sig nal, ASCII serial data, and binary or BCD data from absoluteposition encoders.The output arevoltage or

20、current level to drive end devices such as sole no ids, motor starters, relays, lights, and so on. Other output device in elude an alog devices, digital BCD displays, ASCII compatible devices,servovariable-speeddrives, an deve n computers.Programmable controllers were developed (circa in 1968) when

21、General Motors Corps, and other automobile manufacturerswere experimenting to see if there might be an alter native to scrapp ing all their hardwired con trol panel of mach ine tools and other product ion equipme ntduri ng a model cha ngeover. This annual traditi on was necessarybecaussewriting of t

22、he panelswas more expensivethan buying new ones.The automotive companies approached a number of control equipment manu facturersa nd asked them to develop a control system that would have a Ion ger productive life without major rewriting, but would still be understandableto and repairable by the pla

23、nt personnel. The new product was named a “ programmable con troller”.The processor part of the PLC contains a cen tral process ingunit and memory. The cen tral process ingun it (CPU) is the “ trafficdirectio n ” of the processor, the memory stores in formati on. Comi ng into the processor are the e

24、lectrical sig nals from the in put devices, as con diti oned by the in put module to voltage levels acceptableto processor logic. The processor sca ns the state of I/O and updatesoutputs stored in the memory of the PLC. For example, the processor may be programmed so that if an in put conn ectedto a

25、 limit switch is true (limitswitch closed), the n a corresp ondin goutputwired to an output module is to be energized. This processor remembers this comma ndthrough its memory and compares on each sca n to see if that limit switch is, in fact, closed. If it is closed ,the processorenergizesthe solen

26、oid by turning on the output module.The output device, such as a solenoid or motor starter, is wired to an output module'sterm in al, and it receives its shift sig nal from the processor, in effect, the processor is performing a long and complicated series of logic decisions. The PLC performs su

27、ch decisions sequentially and in according with the stored program. Similarly, analog I/O allows the processorto make decisions based on the magnitude of a signal, rather than just if it is on or off. For example, the processor may be programmedto in crease or decreasethe steam flow to a boiler (an

28、alog output) based on a comparis on of the actual temperaturein the boiler (an alog in put ) This is ofte n performed by utiliz ing the built-i n PID (proporti on al, i ntegral, derivative) capabilities of the processor.Becausea PLC is “ softwaraseef ,s control logic functions can be changedby repro

29、gramming its memory. Keyboard programming devices facilitate entry of the revised program, which can be design to cause an existing machine or processto operate i n a differe nt seque nceor to differe nt level of, or comb in atio ns of stimuli. Hardware modificati ons are n eeded only if additi on a

30、l, cha nged, or relocated in put/output device arei nvo Ived.3. Automated AssemblyAssembly in the manifacturing process consists of putting together all the component parts and sub-assemblies of a given product, fastening, performing inspections and function tests, labeling, separating good assembly

31、 from bad, and packaging and or preparing them for final use. Assembly is unique compared to the methods of manufacturing such as machining, grinding, and welding in that most of these processes invo vie only a few discipli nes and possibly only one. Most of these nonassemblyoperations cannot be per

32、formed weithout the aid of equipment;thus the developmentof automatic methods has been necessaryrather than optional. Assembly, on the other hand, mayinvo lve in one mach in ema ny of the faste ning methods,suchas riveting, welding, screwdriving,and adhesive application,as well as automatic parts se

33、leti on, prod ing, gag ing, fun cti onal test in g, labeli ng,a nd packag ing. The stateof the art in assemblyoperations has not reachedthe level of standardization; much manual work is stillbeing performedin this area.Assembly has traditi on ally bee n one of the highest areas of direct labor costs

34、. In some casesassemblyacco un tsfor 50% or more of manu facturi ng csosts and typically 20%50%. However, closer cooperation between design and manufacturingengin eershas resulted in reduci ng and in a few cases elim in ati ng altogether the n eed for assembly. When asssembly is required, improved d

35、esign or products has simplified automated(semiautomaticor automatic) assembly.Con siderati ons for AutomatedAssemblyBefore automated assemblyis adopted, several factors should be con siderd. These include practicality of the process for automation, simulation for economic con sideratio nsand justif

36、icati on, man ageme ntinvo lveme nt, and labor relati ons.Determining the practicality of automatedassemblyrequired careful evaluation of thefollowi ng:a) The number of partsin assembly.b) Design of the parts with respect to producibility, assembility, automatic handling, and testability (materials,

37、forms, dimensional tolerances, and weights).c) Quality of parts to be assembled.Out-of-tolera nee or defective parts can cause product ion lossesa nd in crease cost由ecauseof stoppages.d) Availablity of qualiyied, technically competentpersonal to be responsible for equipme ntoperatio n.a) Total produ

38、ct ion and producti on-raterequipme nts.Productvariati ons and freque ncy of desig n cha nges.f) Joining methodsrequired.g) Assembly times a nd costs.h) Assembly lines or system configuration, using simulation, including material han dli ng.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

39、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

40、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。所有类型的机加工操作，如钻削、攻丝、铰削、镗削和铣削，在自动生产线上被经济地组合在一起。诸如车削和表面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勺车削工位可供使用。CNC装置允许我们很容易地改变机器工作

41、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、密圭寸垫、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行良好的操作，在自动生产线上进行深钻孔或铰削是一项理想的应用。球面座和其它表面的仿形镗削和车削可 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。对铰孔或镗 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

42、感应加热冷缩配合压在飞轮上、阀座的感应淬火、深度辊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

43、。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程逻辑控制器（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