外文翻譯--生產(chǎn)自動化

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)自動化</b></p><p><b>　　生產(chǎn)自動化介紹</b></p><p>　　自動化

67、是一個在制造成業(yè)中廣泛使用的術(shù)語。文中，自動化可被定義為有關(guān)應(yīng)用機械、電子和計算機的系統(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>　　·加工零件的自動化機床。</p><p>　　·自動連續(xù)生產(chǎn)線和類似的順序生產(chǎn)系統(tǒng)。</p><p><b>　　·自動化裝配機器。</b></p>

68、<p><b>　　·工業(yè)機器人。</b></p><p>　　·自動材料處理和儲存系統(tǒng)。</p><p>　　·用于質(zhì)量控制的自動檢驗系統(tǒng)。</p><p>　　·反饋控制和計算機程序控制。</p><p>　　·使支持制造業(yè)活動的計劃、數(shù)據(jù)收集和決策的過程

69、自動化的計算機系統(tǒng)。</p><p>　　自動化生產(chǎn)系統(tǒng)可被化分為兩個基本類別：硬性自動化和可編程序自動化。</p><p><b>　　硬性自動化</b></p><p>　　硬性自動化是哈德爾（Harder）杜撰“自動化”這個單詞時所提出的。硬性自動化是指生產(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)成一個單一系統(tǒng)使硬性自動化變得復(fù)雜化。硬性自動化的典型特點包括：1 定做設(shè)計設(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)品變更的相對固定性。</p><p>　　硬性自動化對高需求率產(chǎn)品是經(jīng)濟合適的。先期設(shè)備的高投入可以被大量部件分攤，也許是數(shù)百萬件，這樣與其他生產(chǎn)方法相比部件花費低。硬件自動化的例子包括加工連續(xù)生產(chǎn)線、轉(zhuǎn)

71、盤換位機械和自動裝配機器。硬性自動化的大部分技術(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）就是一個例子。</p><p><b>　　可編程自動化</b></p><p>　　對于可編程自動化，以由程序，即一套可以被系統(tǒng)識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）?？删幊套詣踊睦影〝?shù)控機床、工業(yè)機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)的一套機器指令。設(shè)備的實際裝

73、備也必須改變，必須給機器附加特殊的夾具，必須裝上適當?shù)牡毒?。這種轉(zhuǎn)換過程式可能是耗時的。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)成了自動化系統(tǒng)的非生產(chǎn)時間。</p><p>　　可編程自動化的經(jīng)濟要求：隨著設(shè)置-重編程時間增長，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)時間的消耗。相反，如果設(shè)置和重編程時間能降低到零，則批量的大小可降

74、至一個。這是柔性自動化的理論基礎(chǔ)，即可編程自動化的延伸。柔性自動化系統(tǒng)是從一個產(chǎn)品轉(zhuǎn)產(chǎn)到另一個產(chǎn)品時，時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)重編程和改變實際裝備的時間是最少的，并且事實上導(dǎo)致無生產(chǎn)時間損失。因此，系統(tǒng)能在連續(xù)流程中生產(chǎn)不同的產(chǎn)品組合和進程，而不是批處理間有中斷的批處理生產(chǎn)。柔性自動化的特點包括：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)計變更具有柔性。</p><p>　　柔性自動化生產(chǎn)系統(tǒng)通過下面一個或更多的途徑應(yīng)用于實踐中：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/或離線對系統(tǒng)再編程以便再編程不會中斷生產(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際裝備時間；5使用為有限零件類型所設(shè)計的夾具族；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。為了實現(xiàn)這些應(yīng)用，在柔性自動化生產(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化系統(tǒng)要局限的多。柔性自動化生產(chǎn)系統(tǒng)的例子可追溯到20世紀60年代晚期的進行機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化的形式，其中工

77、藝是由數(shù)字、字母和符號來控制的。在數(shù)控中，數(shù)字構(gòu)成了為某特定工件或任務(wù)設(shè)計的指令程序。當任務(wù)變更時，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，在當今工業(yè)的現(xiàn)代機床中大約占15%。因為數(shù)控機床比傳統(tǒng)機床昂貴得多，工業(yè)數(shù)控機床資產(chǎn)價值比起他們的所</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、點焊、弧焊、鉚接、裝配、制圖、檢驗及零件處理等。這絕不是一個完全的列舉。應(yīng)把數(shù)字控制看成一種加工控制的可行方法，用于具有下列特點的任何生產(chǎn)情況：</p><p>　　用原材料加工類似工件（如用于機加工的金屬材料）。</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>　　完成每個工件的加工要求一系列的相似加工步驟。</p><p>　　許多機加工零件滿足這些條件。這些機加工零件是金屬的，給它們規(guī)定了不同的尺寸和形狀，而且當今工業(yè)生產(chǎn)的大部分機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>　　一個可操作的數(shù)字控制系統(tǒng)由下列三個基本部件組成：</p><p><b>　　指令程序。</b></p><p>　　控制器單元，也稱為機床控制單元。</p><p>　　機床或其他被控工藝。</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。這是費時的，除非作為輔助控制手段或只制造成一個或非常有限數(shù)目的零件時，一般很少用。第二種輸入方法是與計算機直接相連。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的指令，通過這些指令可完成一系列加工步驟。對一個機加工操作，加工步驟包括機床臺面和刀具的相對運動，</p>&l

83、t;p><b>　　控制器單元 </b></p><p>　　數(shù)控的第二個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)換成機床機械運動的電子設(shè)備和硬件組成?？刂破鲉卧牡湫驮ù艓ч喿x機、數(shù)據(jù)緩沖器、通向機床的信號輸出通道、來自機床的反饋通道、以及協(xié)調(diào)上述元件整體操作的順序控制器。]</p><p>　　磁帶閱讀機是一個用于纏繞和閱讀含有指令

84、程序的穿孔磁帶的機電裝置。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存在信息邏輯單元。一個信息組通常代表加工元件順序中的一個完整步驟。例如：一個信息組可能是移動機床臺面到特定位置并在該位置鉆孔所需的數(shù)據(jù)。</p><p>　　信號輸出通道與機床的伺服馬達和其他控制器相連。通過這些通道，指令由控制器單元送到機床。為了弄清楚指令是否已被機床正確執(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、是確保臺面和工件已經(jīng)相對于刀具正確定位。為此當今使用的在多數(shù)數(shù)控機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，它不將反饋信號反饋到控制器單元。開環(huán)系統(tǒng)概念的倡議者認為這種系統(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作。磁帶閱讀機執(zhí)行將數(shù)據(jù)從磁帶讀入緩沖器中，來回向機床傳送信號等等。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)的另一個元件是控制面板，它實際上可能是控制器單元 或機床的一部分?？刂泼姘寤蚩刂婆_由刻度盤和開關(guān)組，機床操作者通過他們運轉(zhuǎn)數(shù)控系統(tǒng)?？刂泼姘逡部捎袛?shù)據(jù)顯示器為操作者提供信息。雖然數(shù)控系統(tǒng)是一個自動化系統(tǒng)，但仍需要人類操作者來開關(guān)機床，更換刀具（一些數(shù)據(jù)系統(tǒng)有自動化刀具更換裝置），向機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，操作

87、者必須能控制這個系統(tǒng)，是通過控制面板來完成的。</p><p><b>　　機床</b></p><p>　　數(shù)控系統(tǒng)的第三個元件是機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，一個設(shè)計來完成機加工操作的系統(tǒng)中，機床由工作臺、主軸以及驅(qū)動它們所必要的馬達和控制器組成。它也包括刀具、工件夾具以及其他機加工操作中所需的輔助設(shè)備。<

88、/p><p><b>　　自動生產(chǎn)線</b></p><p>　　使用自動生產(chǎn)線可以利用專用、多功能機床來實現(xiàn)最大程度的自動化。自動生產(chǎn)線實質(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傳送，每個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>　　自動生產(chǎn)線的一個顯著優(yōu)點是它們允許同時完成大量的操作。相對來說，對機加工工件表面或平面的數(shù)量沒有限制，因為裝置可介入自動生產(chǎn)線，實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，使操作在最佳時間完成。經(jīng)?？蛇M行從原始鑄件或鍛件到成品件的完整加工。</p><p>　　一個或多個成品件在一條帶有每個傳輸系統(tǒng)

90、標志的自動生產(chǎn)線上生產(chǎn)，傳輸系統(tǒng)使部件從一個工位運動到更一個工們。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50%，由一條生產(chǎn)線大批生產(chǎn)一個部件時達85%，這取決于工件和如何操作自動生產(chǎn)線（材料處理方法、維護程序等）。</p><p>　　所有類型的機加工操作，如鉆削、攻絲、鉸削、鏜削和銑削，在自動生產(chǎn)線上被經(jīng)濟地組合在一起。諸如車削和表面加工的車床式操作也在直列式自動生產(chǎn)線上完成，工

91、件在選擇的機加工工位上旋轉(zhuǎn)。車削操作在機床部分完成，多刀架通過安裝在隧道式橋形裝置上的滑軌進給。工件定們在中心位置，由在每個車削工們上的卡盤帶動旋轉(zhuǎn)。直列式自動生產(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器工作周期以適應(yīng)工件設(shè)計的改變而且能用于調(diào)整自動刀具。</p><p>　　當工件在傳送機上移動時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行組裝、機加工或測試。完成部件局部裝配后也可進行自動螺帽扭轉(zhuǎn)。</p><p>　　如果能使用合適的機加工裝置并隨后進行良好的軸襯操作，在自動生產(chǎn)線上進行深鉆或鉸削是一項理想的應(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進入工件完成，因此取消了昂貴的專用成形刀具。對鉸孔或鏜孔的測量以及自動刀具的調(diào)整是在自動生產(chǎn)線上進行的，以保持精確的公差。</p>

93、<p>　　有時在自動生產(chǎn)線上進行的非常規(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。除了減少勞動力需求外，這種生產(chǎn)線能保證低成本生產(chǎn)標準始終如一的、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，對自動生產(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)計產(chǎn)品的情況下這些特性是經(jīng)濟可行的?，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間的特殊性能包括標準尺寸、模塊結(jié)構(gòu)、安裝在自動生產(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)計也很重要，如可能在不同的零件上應(yīng)提供常見的移動和夾緊用的表面。</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器的運行或工藝的工序。PLC通過輸入/輸出（I/O）裝置發(fā)出控制信號。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。輸入

96、裝置由限位開關(guān)、按鈕、手輪、開關(guān)、模擬信號、ASCII系列數(shù)據(jù)和來自于絕對位置解碼器的二進制或BCD數(shù)據(jù)組成。輸出的是驅(qū)動電磁線圈、電動機起動機、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)動器、甚至計算機。</p><p>　　當通用汽車公司和其他制造商們正在試驗看能否有另一種方法來銷毀型號轉(zhuǎn)變過程中機床的所有布線控制面板和其他生產(chǎn)設(shè)備時，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，因為控制面板的重新布線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，請他們開發(fā)一個控制系統(tǒng)。這個系統(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、”，存儲器儲存信息。從輸入裝置來的電信號進入處理器后，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)儲存在PLC存儲器中指令更新輸出。例如，處理器可被編程以便當連接限位開關(guān)的輸入位真時（限位開關(guān)閉合），邊在輸出模塊上的輸出裝置被接通，例如，這個輸出裝置可以是電磁線圈。處理器通過存儲器記錄下這個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起動機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。實際上，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）能力來實現(xiàn)的。</p><p&