外文翻譯--生產(chǎn)自動(dòng)化

1、<p>　　Production Automation</p><p>　　Introduction to production Automation</p><p>　　Automation is a widely used term in manufacturing. In this context ,automation can be defined as technolo

2、gy concerned with the application of mechanical, electronic, and computer-based systems to operate and control production. Examples of this technology include:</p><p>　　·Automatic machine tools to proce

3、ss parts.</p><p>　　·Automated transfer lines and similar sequential production systems</p><p>　　·Automatic assembly machines</p><p>　　·Industrial robots</p>&l

4、t;p>　　·Automatic material handing and storage systems</p><p>　　·Automated inspection systems for quality control.</p><p>　　·Feedback control and computer process control.</p

5、><p>　　·Computer systems that automate procedures for planning, data collection, and decision making to support manufacturing activities.</p><p>　　Automated production systems can be classifie

6、d into two basic categories: fixed automation and programmable automation.</p><p>　　Fixed Automation</p><p>　　Fixed automation is what Harder was referring to when he coined the word automation.

7、 Fixed automation refers to production systems in which the sequence of processing or assembly operations is fixed by the equipment configuration and cannot be readily changed without altering the equipment. Although eac

8、h operation in the sequence is usually simple, the integration and complex. Typical features of fixed automation include 1.high initial investment for custom-engineered equipment, 2.high productio</p><p>　　F

9、ixed automation is economically justifiable for products with high demand rates. The high initial investment in the equipment can be divided over a large number of units, perhaps millions, thus making the unit cost low c

10、ompared with alternative methods of production. Examples of fixed automation include transfer lines for machining, dial indexing machines, and automated assembly machines. Much of the technology in fixed automation was d

11、eveloped in the automobile industry; the transfer line (dat</p><p>　　Programmable Automation</p><p>　　For programmable automation, the equipment is designed in such a way that the sequence of pr

12、oduction operations is controlled by a program, i.e., a set of coded instructions that can be read and interpreted by the system. Thus the operation sequence can be readily changed to permit different product configura

13、tions to be produced on the same equipment. Some of the features that characterize programmable automation include 1. high investment in general-purpose programmable equipment, 2. lower pr</p><p>　　Programma

14、ble production systems are often used to produce parts or products in batches. They are especially appropriate when repeat orders for batches of the same product are expected. To produce each batch of a new product, th

15、e system must be programmed with the set of machine instructions that correspond to that product. The physical setup of the equipment must also be changed; special fixtures must be attached to the machine, and the appro

16、priate tools must be loaded. This changeover proced</p><p>　　The economics of programmable automation require that as the setup-reprogramming time increase, the production batch size must be made larger so a

17、s to spread the cost of lost production time over a larger number of units. Conversely , if setup and reprogramming time can be reduced to zero, the batch size can be reduced to one. This is the theoretical basis for fl

18、exible automation, an extension of programmable automation. A flexible automated system is one that is capable of producing a variety</p><p>　　Flexible automated production systems operate in practice by on

19、e or more of the following approaches: 1. using part family concepts, by which the parts made on the system are limited in variety; 2. reprogramming the system in advance and / or off-line, so that reprogramming does no

20、t interrupt production; 3. downloading existing programs to the system to produce previously made parts for which program are already prepared; 4. using quick-change fixtures so that physical setup time is minimized; <

21、;/p><p>　　Numerical Control </p><p>　　Numerical control ( often abbreviated NC) can be defined as a form of programmable automation in which the process is controlled by numbers, letters , and sy

22、mbols. In NC, the numbers form a program of instructions designed for a particular workpart or job. When the job changes, the program of instructions is changed. This capability to change the program for each new job is

23、what gives NC its flexibility . It is much easier to write new programs than to make major changes in the production equ</p><p>　　NC equipment is used in all areas of metal parts fabrication and comprises

24、roughly 15% of the modern machine tools in industry today. Since numerically controlled machines are considerably more expensive than their conventional counterparts , the asset value of industrial NC machine tools is pr

25、oportionally much larger than their numbers. Equipment utilizing numerical control has been designed to perform such diverse operations as drilling, milling, turning, grinding, sheetmetal pressworking s</p><

26、p>　　1.Similar workparts in terms of raw material (e.g. , metal stock for machining).</p><p>　　2.The workparts are produced in various sizes and geometries. </p><p>　　3.The workparts are produ

27、ced in batches of small to medium-sized quantities.</p><p>　　4.A sequence of similar processing steps is required to complete the operation on each workpiece. </p><p>　　Many machining jobs meet

28、these conditions. The machined workparts are metal, they are specified in many different sizes and shapes, and most machined parts produced in industry today are made in small to medium-size lot sizes. To produce each pa

29、rt, a sequence of drilling operations may be required, or a series of turning or milling operations. The suitability of NC for these kinds of jobs is the reason for the tremendous growth of numerical control in the metal

30、working industry over the last 25 y</p><p>　　Basic Components of an NC System </p><p>　　An operational numerical control system consists of the following three basic components :</p><

31、p>　　Program of instructions.</p><p>　　Controller unit, also called machine control unit(MCU).</p><p>　　Machine tool or other controlled process.</p><p>　　Transfer Machines</p&

32、gt;<p>　　The highest degree of automation obtainable with special-purpose , multifunction machines is achieved by using transfer machines. Transfer machines are essentially a combination of individual workstations

33、 arranged in the required sequence, connected by work transfer devices, and integrated with interlocked controls. Workpieces are automatically transferred between the stations, which are equipped with horizontal, vertica

34、l, or angular units to perform machining, gagging, workpiece repositioning, </p><p>　　An important advantage of transfer machines is that they permit the maximum number of operations to be performed simultan

35、eously. There is relatively no limitation on the number of workpiece surfaces of planes that can be machined, since devices can be interposed in transfer machines at practically any point for inverting, rotating, or or

36、ienting the workpiece, so as to complete the machining operations. Work repositioning also minimizes the need for angular machining heads and allows operation</p><p>　　One or more finished parts are produce

37、d on a transfer machine with each index of the transfer system that moves the parts from station to station. Production efficiencies of such machines generally range from 50% for a machine producing a variety of differen

38、t parts to 85% for a machine producing one part, in high production, depending upon the workpiece and how the machine is operated ( materials handling method , maintenance procedures, etc.)</p><p>　　All typ

39、es of machining operations, such as drilling , tapping, reaming, boring, and milling, are economically combined on transfer machines . Lathe-type operations such as turning and facing are also being performed on in-line

40、transfer machine, with the workpieces being rotated in selected machining stations. Turning operations are performed in lathe-type bridge units. Workpieces are located on centers and rotated by chucks at each turning sta

41、tion. Turning stations with CNC are available for use</p><p>　　Maximum production economy on transfer lines is often achieved by assembling parts to the workpieces during their movement through the machine

42、. Such item as bushings, seals , welch plugs, and heat tubes can be assembled and then machined or tested during the transfer machining sequence. Automatic nut torquing following the application of apart subassemblie

43、s can also be carried out. </p><p>　　Gundrilling or reaming on transfer machines is an ideal application provided that proper machining units are employed and good bushing practices are followed . contour bo

44、ring and turning of spherical seats and other surfaces can be done with tracer-controlled single-point inserts, thus eliminating the need for costly special form tools. In-process gagging of reamed or bored holes and aut

45、omatic tool setting are done on transfer machines to maintain close tolerances. </p><p>　　Less conventional operations sometimes performed on transfer machines include grinding , induction heating of ring ge

46、ars for shrink-fit pressing on flywheels, induction hardening of valve seats, deep rolling to apply compressive preloads, and burnishing. </p><p>　　Transfer machines have long been used in the automotive ind

47、ustry for producing identical components at high production rates with a minimum of manual part handling . In addition to decreasing labor requirements , such machines ensure consistently uniform, high-quality parts at l

48、ower cost. They are no longer confined just to rough machining and now often eliminate the need for subsequent operations such as grinding and honing. </p><p>　　More recently, there has been an increasing de

49、mand 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 rearrange and intercha

50、nge machining units , and the provision of idle stations increases the cost of any transfer machine, but such features are economically feasible when product redesigns are common. Many such machines are now being used in

51、 nonautomotive</p><p>　　Special features now available to reduce the time required for part changeover include standardized dimensions, modular construction, interchangeable fixtures mounted on master pallet

52、s that remain on the machine, interchangeable fixture components , the ability to lock out certain stations for different parts by means of selector switches, and programmable controllers. Product design is also impor

53、tant, and common transfer and clamping surfaces should be provided on different parts whenever p</p><p>　　Programmable Logic Controllers </p><p>　　A programmable logic controller (PLC) is a sol

54、id-state device used to control machine motion or process operation by means of a stored program. The PLC sends output control signals and receives input signals through input / output (I/O) devices. A PLC controls ou

55、tputs in response to stimuli at the inputs according to the logic prescribed by the stored program. The inputs are made up of limit switches , pushbuttons, thumbwheels, switches, pulses, analog signals , ASCII serial da

56、ta, and binary</p><p>　　Programmable controllers were developed (circa in 1968) when General Motors Corp, and other automobile manufactures were experimenting to see if there might be an alternative to scrap

57、ping all their hardwired control panels of machine tools and other production equipment during a model changeover .This annual tradition was necessary because rewiring of the panels was more expensive than buying new one

58、s.</p><p>　　The automotive companies approached a number of control equipment manufactures and asked them to develop a control system that would have a longer productive life without major rewiring , but wou

59、ld still be understandable to and repairable by plant personnel. The new product was named a “programmable controller”.</p><p>　　The processor part of the PLC contains a central processing unit and memory .T

60、he central processing unit (CPU) is the “traffic director” of the processor, the memory stores information. Coming into the processor are the electrical signals from the input devices, as conditioned by the input module

61、to voltage levels acceptable to processor logic . The processor scans the state of I/O and updates outputs based on instructions stored in the memory of the PLC .For example, the processor may be progra</p><p&

62、gt;　　The output device ,such as a solenoid or motor starter, is wired to an output module’s terminal, and it receives its shift signal from the processor, in effect, the processor is performing a long and complicated ser

63、ies of logic decisions. The PLC performs such decisions sequentially and in accordance with the stored program. Similarly, analog I/O allows the processor to make decisions based on the magnitude of a signal, rather than

64、 just if it is on or off. For example ,the processor may be progr</p><p>　　Because a PLC is “software based”, ifs control logic functions can be changed by reprogramming its memory. Keyboard programming devi

65、ces facilitate entry of the revised program, which can be designed to cause an existing machine or process to operate in a different sequence or to respond to different levels of, or combinations of stimuli. Hardware mod

66、ifications are needed only if additional, changed, or relocated input/output devices are involved.</p><p><b>　　生產(chǎn)自動(dòng)化</b></p><p><b>　　生產(chǎn)自動(dòng)化介紹</b></p><p>　　自動(dòng)化

67、是一個(gè)在制造成業(yè)中廣泛使用的術(shù)語。文中，自動(dòng)化可被定義為有關(guān)應(yīng)用機(jī)械、電子和計(jì)算機(jī)的系統(tǒng)去管理和控制生產(chǎn)的技術(shù)。這種技術(shù)的例子包括：</p><p>　　·加工零件的自動(dòng)化機(jī)床。</p><p>　　·自動(dòng)連續(xù)生產(chǎn)線和類似的順序生產(chǎn)系統(tǒng)。</p><p><b>　　·自動(dòng)化裝配機(jī)器。</b></p>

68、<p><b>　　·工業(yè)機(jī)器人。</b></p><p>　　·自動(dòng)材料處理和儲(chǔ)存系統(tǒng)。</p><p>　　·用于質(zhì)量控制的自動(dòng)檢驗(yàn)系統(tǒng)。</p><p>　　·反饋控制和計(jì)算機(jī)程序控制。</p><p>　　·使支持制造業(yè)活動(dòng)的計(jì)劃、數(shù)據(jù)收集和決策的過程

69、自動(dòng)化的計(jì)算機(jī)系統(tǒng)。</p><p>　　自動(dòng)化生產(chǎn)系統(tǒng)可被化分為兩個(gè)基本類別：硬性自動(dòng)化和可編程序自動(dòng)化。</p><p><b>　　硬性自動(dòng)化</b></p><p>　　硬性自動(dòng)化是哈德爾（Harder）杜撰“自動(dòng)化”這個(gè)單詞時(shí)所提出的。硬性自動(dòng)化是指生產(chǎn)系統(tǒng)中開關(guān)順序或裝配工作由設(shè)備配置確定，并且在沒更換設(shè)備的情況下不能輕易改變。雖然

70、順序中的每一個(gè)操作通常是簡單的，但是，將許多簡單的操作集成和協(xié)調(diào)成一個(gè)單一系統(tǒng)使硬性自動(dòng)化變得復(fù)雜化。硬性自動(dòng)化的典型特點(diǎn)包括：1 定做設(shè)計(jì)設(shè)備的先期投資高，2 高生產(chǎn)效率，3 應(yīng)用于大批量產(chǎn)品生產(chǎn)，和4 適應(yīng)產(chǎn)品變更的相對(duì)固定性。</p><p>　　硬性自動(dòng)化對(duì)高需求率產(chǎn)品是經(jīng)濟(jì)合適的。先期設(shè)備的高投入可以被大量部件分?jǐn)?，也許是數(shù)百萬件，這樣與其他生產(chǎn)方法相比部件花費(fèi)低。硬件自動(dòng)化的例子包括加工連續(xù)生產(chǎn)線、轉(zhuǎn)

71、盤換位機(jī)械和自動(dòng)裝配機(jī)器。硬性自動(dòng)化的大部分技術(shù)是在汽車工業(yè)中發(fā)展起來的；連續(xù)生產(chǎn)線（追溯到大約1920年）就是一個(gè)例子。</p><p><b>　　可編程自動(dòng)化</b></p><p>　　對(duì)于可編程自動(dòng)化，以由程序，即一套可以被系統(tǒng)識(shí)別和解釋的編碼指令來控制生產(chǎn)操作工序的方式來設(shè)計(jì)設(shè)備。這樣就可毫無困難地改變操作順序以允許在同一設(shè)備上生產(chǎn)不同的產(chǎn)品結(jié)構(gòu)。表現(xiàn)可編

72、程自動(dòng)化的一些特性包括：1 通用可編程設(shè)備的高投入，2比硬性自動(dòng)化更低的生產(chǎn)率，3應(yīng)付產(chǎn)品結(jié)構(gòu)變化的柔性，和4，適合于類似產(chǎn)品或零件的小和/或中等產(chǎn)量的生產(chǎn)（例如，零件族）。可編程自動(dòng)化的例子包括數(shù)控機(jī)床、工業(yè)機(jī)器人和可編程邏輯控制器。</p><p>　　可編程生產(chǎn)系統(tǒng)經(jīng)常用于成批的生產(chǎn)零件或產(chǎn)品。它們尤其適合于相同產(chǎn)品成批的重復(fù)訂單。為了生產(chǎn)一批新產(chǎn)品，必須為系統(tǒng)編制與新產(chǎn)品相適應(yīng)的一套機(jī)器指令。設(shè)備的實(shí)際裝

73、備也必須改變，必須給機(jī)器附加特殊的夾具，必須裝上適當(dāng)?shù)牡毒摺＿@種轉(zhuǎn)換過程式可能是耗時(shí)的。結(jié)果，一批特定產(chǎn)品的一般生產(chǎn)周期包括1完成準(zhǔn)備和重編程的階段和2 該批產(chǎn)品的加工階段。設(shè)置-重編程階段構(gòu)成了自動(dòng)化系統(tǒng)的非生產(chǎn)時(shí)間。</p><p>　　可編程自動(dòng)化的經(jīng)濟(jì)要求：隨著設(shè)置-重編程時(shí)間增長，生產(chǎn)批量的大小必須被編得較大以便在眾多設(shè)備中分散損失的生產(chǎn)時(shí)間的消耗。相反，如果設(shè)置和重編程時(shí)間能降低到零，則批量的大小可降

74、至一個(gè)。這是柔性自動(dòng)化的理論基礎(chǔ)，即可編程自動(dòng)化的延伸。柔性自動(dòng)化系統(tǒng)是從一個(gè)產(chǎn)品轉(zhuǎn)產(chǎn)到另一個(gè)產(chǎn)品時(shí)，時(shí)間損失最少的能生產(chǎn)許多種類產(chǎn)品（或零件）的系統(tǒng)。系統(tǒng)重編程和改變實(shí)際裝備的時(shí)間是最少的，并且事實(shí)上導(dǎo)致無生產(chǎn)時(shí)間損失。因此，系統(tǒng)能在連續(xù)流程中生產(chǎn)不同的產(chǎn)品組合和進(jìn)程，而不是批處理間有中斷的批處理生產(chǎn)。柔性自動(dòng)化的特點(diǎn)包括：1用于工程定制系統(tǒng)的高投資2連續(xù)的產(chǎn)品混合生產(chǎn)。3改變產(chǎn)品混合以適應(yīng)對(duì)所生產(chǎn)的不同產(chǎn)品的需求率能力，4中等生產(chǎn)率

75、，和5處理產(chǎn)品設(shè)計(jì)變更具有柔性。</p><p>　　柔性自動(dòng)化生產(chǎn)系統(tǒng)通過下面一個(gè)或更多的途徑應(yīng)用于實(shí)踐中：1使用零件族概念，根據(jù)此概念系統(tǒng)中制造的零件在種類上有限制；2預(yù)先，并且/或離線對(duì)系統(tǒng)再編程以便再編程不會(huì)中斷生產(chǎn)；3下載已有程序到系統(tǒng)中來生產(chǎn)以前制造過的零件，為這些零件已編寫過程序；4使用快速裝卸的夾具以便最大限度地縮短實(shí)際裝備時(shí)間；5使用為有限零件類型所設(shè)計(jì)的夾具族；和6給系統(tǒng)裝配大量的快速裝卸刀具

76、，它們包括用來生產(chǎn)零件族的各式各樣的加工操作工具。為了實(shí)現(xiàn)這些應(yīng)用，在柔性自動(dòng)化生產(chǎn)系統(tǒng)上生產(chǎn)的零件類型的變化通常比批處理類型的可編程自動(dòng)化系統(tǒng)要局限的多。柔性自動(dòng)化生產(chǎn)系統(tǒng)的例子可追溯到20世紀(jì)60年代晚期的進(jìn)行機(jī)加工操作的柔性制造系統(tǒng)。</p><p><b>　　數(shù)字控制</b></p><p>　　數(shù)字控制（?？s寫為數(shù)控）可定義為一種可編程自動(dòng)化的形式，其中工

77、藝是由數(shù)字、字母和符號(hào)來控制的。在數(shù)控中，數(shù)字構(gòu)成了為某特定工件或任務(wù)設(shè)計(jì)的指令程序。當(dāng)任務(wù)變更時(shí)，指令程序也相應(yīng)改變，改變每種新任務(wù)程序的能力使數(shù)控具有柔性。編寫新程序比改變主要生產(chǎn)設(shè)備要容易得多。</p><p>　　數(shù)控設(shè)備用于所有的金屬零件制造領(lǐng)域，在當(dāng)今工業(yè)的現(xiàn)代機(jī)床中大約占15%。因?yàn)閿?shù)控機(jī)床比傳統(tǒng)機(jī)床昂貴得多，工業(yè)數(shù)控機(jī)床資產(chǎn)價(jià)值比起他們的所</p><p>　　占比值來要大

78、得多。應(yīng)用數(shù)控的設(shè)備已被用來定然成各式各樣的操作，如鉆削、銑削、車削、磨削、鈑金壓制、點(diǎn)焊、弧焊、鉚接、裝配、制圖、檢驗(yàn)及零件處理等。這絕不是一個(gè)完全的列舉。應(yīng)把數(shù)字控制看成一種加工控制的可行方法，用于具有下列特點(diǎn)的任何生產(chǎn)情況：</p><p>　　用原材料加工類似工件（如用于機(jī)加工的金屬材料）。</p><p>　　工件被生產(chǎn)成各種尺寸和形狀。</p><p>

79、　　以小到中等規(guī)模批量生產(chǎn)工件。</p><p>　　完成每個(gè)工件的加工要求一系列的相似加工步驟。</p><p>　　許多機(jī)加工零件滿足這些條件。這些機(jī)加工零件是金屬的，給它們規(guī)定了不同的尺寸和形狀，而且當(dāng)今工業(yè)生產(chǎn)的大部分機(jī)加零件被制成小到中等規(guī)模的多種尺寸。為了生產(chǎn)第一個(gè)零件，需要一系列的鉆削操作或一系列的車削或銑削操作。數(shù)字控制對(duì)這引起零件的適應(yīng)性是數(shù)字控制在過去25年中在金屬制造

80、業(yè)中巨大增大的原因。</p><p>　　數(shù)字控制系統(tǒng)的基本部件</p><p>　　一個(gè)可操作的數(shù)字控制系統(tǒng)由下列三個(gè)基本部件組成：</p><p><b>　　指令程序。</b></p><p>　　控制器單元，也稱為機(jī)床控制單元。</p><p>　　機(jī)床或其他被控工藝。</p>

81、<p><b>　　指令程序</b></p><p>　　指令程序是告訴機(jī)床如何去工作的一套詳盡的一步步的指令集。它被以數(shù)字或符號(hào)的形式編碼在一些可以被控制器單元翻譯的輸入介質(zhì)上。最常用的輸入介質(zhì)是1英寸寬的穿孔帶。在這些年中，也使用了其他形式的輸入介質(zhì)，包括穿孔片、磁帶、甚至35mm電影膠片。</p><p>　　還有其他兩種向數(shù)字控制系統(tǒng)進(jìn)行輸入的方

82、法必須提及。第一種是用手工將指令數(shù)據(jù)輸入到控制器單元。這是費(fèi)時(shí)的，除非作為輔助控制手段或只制造成一個(gè)或非常有限數(shù)目的零件時(shí)，一般很少用。第二種輸入方法是與計(jì)算機(jī)直接相連。這叫做直接數(shù)字控制或DNC。</p><p>　　指令程序是由被稱為部件工作程序員的人編寫的。程序員的工伯是提供一套詳細(xì)的指令，通過這些指令可完成一系列加工步驟。對(duì)一個(gè)機(jī)加工操作，加工步驟包括機(jī)床臺(tái)面和刀具的相對(duì)運(yùn)動(dòng)，</p>&l

83、t;p><b>　　控制器單元 </b></p><p>　　數(shù)控的第二個(gè)基本元件是控制器單元 。這由可以閱讀和翻譯指令程序并把它轉(zhuǎn)換成機(jī)床機(jī)械運(yùn)動(dòng)的電子設(shè)備和硬件組成?？刂破鲉卧牡湫驮ù艓ч喿x機(jī)、數(shù)據(jù)緩沖器、通向機(jī)床的信號(hào)輸出通道、來自機(jī)床的反饋通道、以及協(xié)調(diào)上述元件整體操作的順序控制器。]</p><p>　　磁帶閱讀機(jī)是一個(gè)用于纏繞和閱讀含有指令

84、程序的穿孔磁帶的機(jī)電裝置。磁帶上含有的數(shù)據(jù)被讀入數(shù)據(jù)緩沖器。該設(shè)備的目的是將輸入指令儲(chǔ)存在信息邏輯單元。一個(gè)信息組通常代表加工元件順序中的一個(gè)完整步驟。例如：一個(gè)信息組可能是移動(dòng)機(jī)床臺(tái)面到特定位置并在該位置鉆孔所需的數(shù)據(jù)。</p><p>　　信號(hào)輸出通道與機(jī)床的伺服馬達(dá)和其他控制器相連。通過這些通道，指令由控制器單元送到機(jī)床。為了弄清楚指令是否已被機(jī)床正確執(zhí)行，反饋數(shù)據(jù)通過反饋通道回到控制器。反饋回路的重要功能

85、是確保臺(tái)面和工件已經(jīng)相對(duì)于刀具正確定位。為此當(dāng)今使用的在多數(shù)數(shù)控機(jī)床具有位置反饋控制器，并被稱為“閉環(huán)系統(tǒng)”。然而，近此年開環(huán)系統(tǒng)的使用呈增長趨勢，它不將反饋信號(hào)反饋到控制器單元。開環(huán)系統(tǒng)概念的倡議者認(rèn)為這種系統(tǒng)的可靠性足夠高，因此反饋控制器是不需要的，是一筆不必要的額外花銷。</p><p>　　順序控制器協(xié)調(diào)控制器單元其他元件的動(dòng)作。磁帶閱讀機(jī)執(zhí)行將數(shù)據(jù)從磁帶讀入緩沖器中，來回向機(jī)床傳送信號(hào)等等。這些類型的操

86、作必須是同步的，這就是同步控制器的功用。</p><p>　　數(shù)控系統(tǒng)的另一個(gè)元件是控制面板，它實(shí)際上可能是控制器單元 或機(jī)床的一部分?？刂泼姘寤蚩刂婆_(tái)由刻度盤和開關(guān)組，機(jī)床操作者通過他們運(yùn)轉(zhuǎn)數(shù)控系統(tǒng)。控制面板也可有數(shù)據(jù)顯示器為操作者提供信息。雖然數(shù)控系統(tǒng)是一個(gè)自動(dòng)化系統(tǒng)，但仍需要人類操作者來開關(guān)機(jī)床，更換刀具（一些數(shù)據(jù)系統(tǒng)有自動(dòng)化刀具更換裝置），向機(jī)床加載和卸載以及完成其他各式各樣的任務(wù)，為了履行這些職責(zé)，操作

87、者必須能控制這個(gè)系統(tǒng)，是通過控制面板來完成的。</p><p><b>　　機(jī)床</b></p><p>　　數(shù)控系統(tǒng)的第三個(gè)元件是機(jī)床或其他被控制的工序。它是數(shù)控系統(tǒng)完成有用工作的部分。在最常見的數(shù)控系統(tǒng)例子中，一個(gè)設(shè)計(jì)來完成機(jī)加工操作的系統(tǒng)中，機(jī)床由工作臺(tái)、主軸以及驅(qū)動(dòng)它們所必要的馬達(dá)和控制器組成。它也包括刀具、工件夾具以及其他機(jī)加工操作中所需的輔助設(shè)備。<

88、/p><p><b>　　自動(dòng)生產(chǎn)線</b></p><p>　　使用自動(dòng)生產(chǎn)線可以利用專用、多功能機(jī)床來實(shí)現(xiàn)最大程度的自動(dòng)化。自動(dòng)生產(chǎn)線實(shí)質(zhì)上是那些由工件傳送裝置連接起來的按所需順序布置的單個(gè)工位的組合，并且通過連鎖控制集成為一體。工件在工位間被自動(dòng)傳送，每個(gè)工位都裝有用于加工、測量、工件再定位、組裝、清洗或其他操作的臥式、立式、傾斜式設(shè)備。自動(dòng)生產(chǎn)線的兩大主要類別是旋

89、轉(zhuǎn)式和直列式。</p><p>　　自動(dòng)生產(chǎn)線的一個(gè)顯著優(yōu)點(diǎn)是它們允許同時(shí)完成大量的操作。相對(duì)來說，對(duì)機(jī)加工工件表面或平面的數(shù)量沒有限制，因?yàn)檠b置可介入自動(dòng)生產(chǎn)線，實(shí)際上在任意位置能使工件翻轉(zhuǎn)、旋轉(zhuǎn)或定向以便完成機(jī)加工操作。工件重定位也使傾斜主軸箱的數(shù)目減至最小，使操作在最佳時(shí)間完成。經(jīng)?？蛇M(jìn)行從原始鑄件或鍛件到成品件的完整加工。</p><p>　　一個(gè)或多個(gè)成品件在一條帶有每個(gè)傳輸系統(tǒng)

90、標(biāo)志的自動(dòng)生產(chǎn)線上生產(chǎn)，傳輸系統(tǒng)使部件從一個(gè)工位運(yùn)動(dòng)到更一個(gè)工們。這類生產(chǎn)線的生產(chǎn)率通常為50%~85%，由一條生產(chǎn)線生產(chǎn)各式各樣部件時(shí)50%，由一條生產(chǎn)線大批生產(chǎn)一個(gè)部件時(shí)達(dá)85%，這取決于工件和如何操作自動(dòng)生產(chǎn)線（材料處理方法、維護(hù)程序等）。</p><p>　　所有類型的機(jī)加工操作，如鉆削、攻絲、鉸削、鏜削和銑削，在自動(dòng)生產(chǎn)線上被經(jīng)濟(jì)地組合在一起。諸如車削和表面加工的車床式操作也在直列式自動(dòng)生產(chǎn)線上完成，工

91、件在選擇的機(jī)加工工位上旋轉(zhuǎn)。車削操作在機(jī)床部分完成，多刀架通過安裝在隧道式橋形裝置上的滑軌進(jìn)給。工件定們在中心位置，由在每個(gè)車削工們上的卡盤帶動(dòng)旋轉(zhuǎn)。直列式自動(dòng)生產(chǎn)線上有CNC的車削工位可供使用。CNC裝置允許我們很容易地改變機(jī)器工作周期以適應(yīng)工件設(shè)計(jì)的改變而且能用于調(diào)整自動(dòng)刀具。</p><p>　　當(dāng)工件在傳送機(jī)上移動(dòng)時(shí)通過將零件裝到工件上，經(jīng)?？梢垣@得連續(xù)生產(chǎn)線上最大的生產(chǎn)效益。在傳送加工過程中，能夠?qū)χT如

92、軸襯、密封墊、威爾士襯套和保溫管等零件進(jìn)行組裝、機(jī)加工或測試。完成部件局部裝配后也可進(jìn)行自動(dòng)螺帽扭轉(zhuǎn)。</p><p>　　如果能使用合適的機(jī)加工裝置并隨后進(jìn)行良好的軸襯操作，在自動(dòng)生產(chǎn)線上進(jìn)行深鉆或鉸削是一項(xiàng)理想的應(yīng)用。球面座和其他表面的仿形鏜削和車削可用仿形控制單點(diǎn)進(jìn)入工件完成，因此取消了昂貴的專用成形刀具。對(duì)鉸孔或鏜孔的測量以及自動(dòng)刀具的調(diào)整是在自動(dòng)生產(chǎn)線上進(jìn)行的，以保持精確的公差。</p>

93、<p>　　有時(shí)在自動(dòng)生產(chǎn)線上進(jìn)行的非常規(guī)加工包括磨削、環(huán)形齒輪的感應(yīng)加熱以冷縮配合壓在飛輪上、閥座的感應(yīng)淬火、深度輥壓以施加預(yù)壓載荷和拋光。</p><p>　　自動(dòng)生產(chǎn)線很早就用于汽車工業(yè)來高效率地生產(chǎn)相同部件，手工零件加工量極少。除了減少勞動(dòng)力需求外，這種生產(chǎn)線能保證低成本生產(chǎn)標(biāo)準(zhǔn)始終如一的、高質(zhì)量零件。它們不再局限于粗加工，現(xiàn)在已經(jīng)取消了諸如拋光和搪磨這樣的后來工序。</p>&l

94、t;p>　　目前，對(duì)自動(dòng)生產(chǎn)線的需求越來越多，用來處理少量的小尺寸的相似的或甚至不同的零件，用于生產(chǎn)經(jīng)營的快速轉(zhuǎn)換。內(nèi)置柔性，即重新設(shè)計(jì)產(chǎn)品的情況下這些特性是經(jīng)濟(jì)可行的?，F(xiàn)在許多這樣的生產(chǎn)線已用在非汽車領(lǐng)域里來滿足少量的生產(chǎn)要求。</p><p>　　現(xiàn)在用于減少零件更換時(shí)間的特殊性能包括標(biāo)準(zhǔn)尺寸、模塊結(jié)構(gòu)、安裝在自動(dòng)生產(chǎn)線主托架上的互換性夾具、可互換的夾具零件、借助選擇開關(guān)將不同的部件鎖定在具體工位上的能

95、力和可編程控制器。產(chǎn)品設(shè)計(jì)也很重要，如可能在不同的零件上應(yīng)提供常見的移動(dòng)和夾緊用的表面。</p><p><b>　　可編程控制器</b></p><p>　　可編程邏輯控制器（PLC）是一種固態(tài)電子裝置，它利用已存入的程序來控制機(jī)器的運(yùn)行或工藝的工序。PLC通過輸入/輸出（I/O）裝置發(fā)出控制信號(hào)。PLC依據(jù)已存入程序所規(guī)定的邏輯控制輸出裝置響應(yīng)輸入裝置的激勵(lì)。輸入

96、裝置由限位開關(guān)、按鈕、手輪、開關(guān)、模擬信號(hào)、ASCII系列數(shù)據(jù)和來自于絕對(duì)位置解碼器的二進(jìn)制或BCD數(shù)據(jù)組成。輸出的是驅(qū)動(dòng)電磁線圈、電動(dòng)機(jī)起動(dòng)機(jī)、繼電器、批示燈等終端設(shè)備的電壓或電流電平。其他輸出裝置包括模擬裝置、數(shù)字BCD顯示、ASCII兼容裝置、伺服變速驅(qū)動(dòng)器、甚至計(jì)算機(jī)。</p><p>　　當(dāng)通用汽車公司和其他制造商們正在試驗(yàn)看能否有另一種方法來銷毀型號(hào)轉(zhuǎn)變過程中機(jī)床的所有布線控制面板和其他生產(chǎn)設(shè)備時(shí)，P

97、LC被研制成了（大約在1968年）。這種年度例行工作是必要的，因?yàn)榭刂泼姘宓闹匦虏季€比購買新的控制面板要昂貴得多。</p><p>　　汽車公司與許多控制設(shè)備制造商打交道，請(qǐng)他們開發(fā)一個(gè)控制系統(tǒng)。這個(gè)系統(tǒng)要有較長的生產(chǎn)壽命而無須主要線路重新布線，并且能被工廠人員所理解和維修。這個(gè)新系統(tǒng)被稱作“可編程控制器”。</p><p>　　PLC的處理器部分由中央處理器（CPU）是處理的“交通控制器

98、”，存儲(chǔ)器儲(chǔ)存信息。從輸入裝置來的電信號(hào)進(jìn)入處理器后，經(jīng)輸入模塊整理成處理器邏輯單元可接受的電壓電平。處理器監(jiān)測I/O的狀態(tài)，然后依據(jù)儲(chǔ)存在PLC存儲(chǔ)器中指令更新輸出。例如，處理器可被編程以便當(dāng)連接限位開關(guān)的輸入位真時(shí)（限位開關(guān)閉合），邊在輸出模塊上的輸出裝置被接通，例如，這個(gè)輸出裝置可以是電磁線圈。處理器通過存儲(chǔ)器記錄下這個(gè)指令并與每次檢測相比較以確定限位開關(guān)是否真正閉合。如果閉合，處理器通過接通輸出模塊接通電磁線圈。</p&g

99、t;<p>　　諸如電磁線圈或電動(dòng)起動(dòng)機(jī)之類的輸出裝置被連接到輸出模塊的接線柱上，并從處理器接受它的位移信號(hào)。實(shí)際上，處理器在完成一系列長而復(fù)雜的邏輯判斷。PLC按順序并根據(jù)存儲(chǔ)的程序來執(zhí)行這樣的判斷。同樣地，模擬I/O裝置允許處理器依據(jù)信號(hào)的大小而不是其接通或關(guān)閉來做判斷。例如，處理器可被編程為根據(jù)鍋爐實(shí)際溫度（模擬輸出）。這通常是用處理器的內(nèi)置PID（比例，積分、微分）能力來實(shí)現(xiàn)的。</p><p&