2023年全國碩士研究生考試考研英語一試題真題(含答案詳解+作文范文)_第1頁
已閱讀1頁,還剩7頁未讀, 繼續(xù)免費(fèi)閱讀

下載本文檔

版權(quán)說明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請(qǐng)進(jìn)行舉報(bào)或認(rèn)領(lǐng)

文檔簡介

1、<p><b>  外文翻譯</b></p><p><b>  英文原文:</b></p><p>  Flexible Manufacturing System</p><p>  A logical step from the concepts of group layout and of NC machi

2、ne tools and robotics are computer-controlled interlinked outstation machining complexes, or 11exibe manufacturing systems(FMS)as they have bedclothes call.do.Such systems can be looked upon as highly automated cells man

3、ufacturing families of components.</p><p>  The concept of FMS is not a new one; the first proposals were made in the mid 1960s. In recent years we have seen a growth in the number of systems, particularly i

4、n Japan, such that it is estimated that in excess of a hundred systems have been installed worldwide. A flexible manufacturing system contains a number of features as follows:</p><p>  1. Interlinked NC work

5、stations operating on a limited range or family of work pieces. In early propos-ales the machines were of modular construction, but in recent systems general-purpose NC machines, in particular machining centers, are most

6、 commonly used.</p><p>  2. Automatic transportation, loading at unloading of work pieces and tools, using automatic guided vehicles (AGVs), robots, etc.</p><p>  3. Work pieces mounted on palle

7、ts ft* transportation, pattly to overcome the problems of new setups at each workstation.</p><p>  4. Centralized NC or DNC, together with overall computer control of the system.</p><p>  5. Ope

8、ration for significant periods of time with little or no manual intervention.</p><p>  With FMS the tern flexibility means the ability to aptness a variety of components without having to adjust machine setu

9、ps. Or change tooling. High flexibility implies that a large family of different components can be produced by the particular system. Figure 5. 17 show that several variants of the basic FMS con-kept exist. These are;<

10、;/p><p>  l.Flexible manufacturing cells(FMs): These are basically machining centum but with the addition of a pallet pool or magazine(Fig.5. t8 ).The aim is to machine the work piece with one stupefies type of

11、 machine can be operated unmanned for long periods of time, with the palletized work pieces transformed au-somatically to and from the machine. Flexible manufacturing cells of this type must be served by machines or oper

12、ators engaged in blank preparation and polarization of work pieces. These cells </p><p>  2. Flexible transfer lines (fall): These, systems consist of a number of NC or head-changeable ma chine tools connect

13、ed by automatic material transfer systems. The system can machine different components but without flexible routing of the workpieces.The family of components is relatively small (< 20) and the components must be quit

14、e similar to one another, as the overall flexibility of tote system is too low for a larger variety to be accommodated@. In consequence, the work cycles at each stati</p><p>  3. Flexible manufacturing syste

15、ms (FMS), in these systems NC workstations are linked by automatic work piece transfer and handing. With flexible routing and automatic work piece loading and unloading. A-chining times at each station can differ conside

16、rably. The number of different components that can be pro-cussed by these systems is 'ohm 10 'o 150 in general and moderate quantities can be produced (15 to 500 components per annum for type)</p><p>

17、;  1.Work Handling for FMS</p><p>  Work pieces are usually mounted on standard pallets for processing in FMS and these pallets locate automatically at each workstation in the system. A variety of work-handl

18、ing devices are used to transport parts, pallets, and tools around the system. Some of these ate as follows:</p><p>  1. Tow carts: These are the most cannon devices used; they consist of a simple platform o

19、n castors and are towed around the system by engagement with under floor, continuously moving chains. Cats stop at workstations by means of a mechanism total releases the tow pin at the appropriate time. Branches and loo

20、ps are canalled in a similar manner to railway systems. 11te main advantage of tow carts is their simplicity and low cost, since no on-board power is required for their movement or control. F</p><p>  2. Aut

21、omatic guided vehicles (AGVs). These devices are usually designed to follow wins buried in the floor of the plant or lines painted on tote floor. On-board power and control is required for bolt move mint and steering ate

22、 for tote handling of pallets. Automatic guided vehicles ate more expensive than tow cats and are both larger and heavier. Tale main advantage of AGVs is their greater flexibility of opera-ton. These devices may move in

23、either direction, but for ease of control, circulation</p><p>  3. Rail cats: These carts move on rails and are generally restricted to backward and forward motion along straight tracks. Power and control in

24、structions ate ttunsferred by overhead conductors or extra rails. Rail carts often accommodate two pallets to allow for pallet exchange at the system workstations.</p><p>  4. Roller conveyors: Most of tote

25、early FMS developments utilized powered-roller conveyors for moving work pieces from statuette to station. The use of these convents in modern systems is less common. Roller conveyors are expensive to install and occupy

26、valuable floor space. In addition, these conveyors are relatively inflexible in operation and difficult to alter if the overall system is expanded.</p><p>  5. Industrial robots: Robots are used in FMS but n

27、ot extensively unless the cell consists of only a few machines. They may be used as second at) handling devices, particularly for turned work pieces, which may be transported around the system in hatches on pallets by ot

28、her handling devices and then transferred to the machine tool by robots at each workstation. Gripper designs suitable for handling a wide variety of components are important in this case.</p><p>  2. Layouts

29、 for FMS</p><p>  A variety of different layouts for the machine tools in FMS have been adopted, The choice depends on the scope of the system and the type of handling devices used for transporting work piec

30、es from workstation to workstation. The use of rail carts mean that a straight track must be used, with machines located at the side of tote track. Early systems using roller conveyors usually employed a simple loop conf

31、igura-tio11, with branches to the workstations.</p><p>  The increased use of tow carts and AGVs has resulted in more complex multicolor or tree-type layouts being used. The latter type is most suitable for

32、AGVs and is particularly useful if expansion of the system with additional workstations is anticipated. Figure 5.19 shows a typical multicolor layout using tow carts, and Fig.5.20 shows a typical layout where AGVs are us

33、ed for work handling.</p><p>  3. Factory of the Future</p><p>  On the basis of the advances made to date in all aspects of manufacturing technology and computer controls, we may envisage the f

34、actory of the future as a fully automated facility in which human beings would not be directly involved with production on the shop i1oor (hence the term unmanned factories).All manufacturing, material handling, assembly

35、, and inspection would be done by automated and computer-controlled machinery and equipment.</p><p>  Similarly, activities such as processing incoming orders, production planning and scheduling, cost accoun

36、ting, and various decision-making processes (usually performed by management) would also be done automatically by computers. The role of human beings would be confined to activities such as supervising, maintaining (espe

37、cially preventive maintenance), and upgrading machines and equipment; ship-ping and receiving supplies and finished products ; providing security for the plant facilities ; an</p><p>  Industries such as som

38、e food, petroleum, and chemical already operate automatically with little human intervention. These are continuous processes and, unlike piece part manufacturing, are easier to automate fully. Even so, the direct involve

39、ment of fewer people in manufacturing products is already apparent: Surveys show that; only 10-15 percent of the workforce is directly involved in production. Most of the workforce is involved in gathering and processing

40、 information.</p><p>  Virtually unmanned manufacturing cells already make products such as engine blocks, axles, and housings for clutches and air compressors .For large-scale, flexible manufacturing system

41、s, however, highly trained and skilled personnel will always be needed to plan, maintain, and oversee operation.</p><p>  The reliability of machines, control systems, and power supply is crucial to full fac

42、tory automation. A local or general breakdown in machinery, computers, power, or communications networks will, without rapid human intervention cripple production. The computer-integrated factory of the future should be

43、capable of automatically rerouting materials and production flows to other computers in case of such emergencies.</p><p><b>  譯文:</b></p><p><b>  柔性制造系統(tǒng)</b></p>&l

44、t;p>  以成組布局的方式,將由計(jì)算機(jī)控制的多臺(tái)數(shù)控機(jī)床及機(jī)器人結(jié)合成多工位成套加工設(shè)備,即稱為柔性制造系統(tǒng)(FMS),這種系統(tǒng)被視為對(duì)各類零件族進(jìn)行加工的高度自動(dòng)化制造單元。</p><p>  FMS并非是新的頓念,首先是在二十世紀(jì)60年代中期提出的。近年來FMS的數(shù)量不斷增加,尤其是日本。據(jù)估計(jì),世界上建立起來的FMS已經(jīng)超過了一百套。柔性制造系統(tǒng)具有以下一些特征:

45、 </p><p>  l。將對(duì)范圍有效的零件或某族零件進(jìn)行加工的多臺(tái)效控工作站互相聯(lián)結(jié)。早期規(guī)劃時(shí)FMS中的機(jī)床都采用單元結(jié)構(gòu)、而近年來生產(chǎn)的FMS基本上采用通用數(shù)控機(jī)床,尤其是加工中心。 </p><p>  2.通過自動(dòng)運(yùn)輸小車(AGVs)機(jī)械手等設(shè)備時(shí)工件及刀具進(jìn)行自動(dòng)運(yùn)送和裝卸。</p><p>  

46、3.為便于傳輸,將工件裝在托盤上,部分解決了工件裝到每個(gè)工作站上去需進(jìn)行重新調(diào)整的問題。</p><p>  4.?dāng)?shù)控系統(tǒng)或直接數(shù)控系統(tǒng)與系統(tǒng)的計(jì)算機(jī)總體控制一起實(shí)行集中管理。</p><p>  5.主要的加工過程無須人工干預(yù)或較少人工干預(yù)。</p><p>  柔性制造系統(tǒng)這一術(shù)語中的柔性意味著該系統(tǒng)在不必調(diào)整機(jī)床設(shè)備或更換工藝裝備的情況下就能加工各類零件。柔性

47、大是指萊某一特定的系統(tǒng)能加工某一大零件族的不同零件。圖5。I 7示表示了現(xiàn)有的基本的FMS概念引出的一些派生系統(tǒng),即:</p><p>  1.柔性制造單元(FMS):它基本上是帶有托盤庫或托盤站的加工中心(圖5,1 8)。其目的是在一次安裝下便可加工出工件。這種柔性制造單元可長時(shí)間無人看管。裝在托盤中的工件可自動(dòng)送達(dá)以及運(yùn)離該加工機(jī)床。這種類型的柔性制造單元必須由機(jī)械裝置或操作人員進(jìn)行毛坯準(zhǔn)備前將工件裝在托盤上

48、。柔性制造單元的加工柔性高,可小批量(15到5 00)地加工多種零件(40 ~8 00種)。</p><p>  2.柔性自動(dòng)線〈LTLs)。這些系統(tǒng)是由多臺(tái)數(shù)控機(jī)床或可更換主軸箱的機(jī)床所組成,機(jī)床之間通過物料自動(dòng)輸送系統(tǒng)相聯(lián)接。此系統(tǒng)可加工不同的零件,但工件的加工路線不能變動(dòng)。可加工的零件族種類比較少(<20)而且它們之間必須十分相似,這是因?yàn)檫@類系統(tǒng)的柔性太小,所加工的工件不可變化太太。所以每個(gè)工作站上的加工

49、時(shí)間必須相等。要使這些系統(tǒng)加工經(jīng)濟(jì)則產(chǎn)量必頌大(每種零件的年產(chǎn)量應(yīng)為1500到15000件)。</p><p>  3.柔性制造系統(tǒng)(FMS)。此類系統(tǒng)的數(shù)控工作站由工件的自動(dòng)榜送和搬運(yùn)系統(tǒng)相聯(lián)接,能夠改變加工路線,并可自動(dòng)裝卸工件。每個(gè)工作站的加工時(shí)間可能相差較大。柔性制造系統(tǒng)可加工的零件種類一放為10~ 150種,適于中等批量的生產(chǎn)〈每一類零件的年產(chǎn)量為15 到 500件〉。圖5。17 各種FMS的概念柔性自

50、動(dòng)化。 </p><p>  柔性自動(dòng)線:機(jī)床內(nèi)部聯(lián)系;多用途加工;周期地輸送工件;控制物料流動(dòng);加工設(shè)備的部分運(yùn)用性,其調(diào)整時(shí)間較短。</p><p>  柔性制造系統(tǒng):機(jī)床外部聯(lián)系,單用途和/或多用途加工;非周期輸送工作;物料按各種順序自動(dòng)流動(dòng);對(duì)手少量的試件無需進(jìn)行手工調(diào)整。</p><p>  柔性制造單元:沒有內(nèi)部聯(lián)系的獨(dú)立設(shè)置的機(jī)床;單級(jí)加工;機(jī)

51、床裝載工作,具有一個(gè)緩沖工位的機(jī)床;帶有工件庫的機(jī)床; 自動(dòng)換刀。圖5,l 8 典型的用于無人操作的加工中心,它帶有托盤、刀庫及CNC控制可與主計(jì)算機(jī)通訊。自動(dòng)換刀機(jī)構(gòu);刀庫;CNC控制單元;自動(dòng)除屑裝置;托盤庫。</p><p>  1.柔性制造系統(tǒng)的工件輸送裝置</p><p>  FMSs中通常將工件安裝在托盤上以便進(jìn)行加工,托盤在系統(tǒng)的每一工位上自動(dòng)定位。采用了各種輸送裝置以便在系

52、統(tǒng)中運(yùn)送工件、托盤及刀具,其中輸送裝置是:</p><p>  1.牽引車:這是最常用的輸送裝置,它由自位輪上的簡單平臺(tái)組成,通過地下連續(xù)移動(dòng)的傳輸鏈牽引繞系統(tǒng)運(yùn)動(dòng)。通過一機(jī)械裝置在適當(dāng)?shù)臅r(shí)間松開牽引銷使?fàn)恳囋诟鞴の煌O隆_\(yùn)輸線路的分支及其回路的控制叫方式類似于鐵路系統(tǒng)。由于牽引車的運(yùn)動(dòng)或控制不需要車上能源,所以拖車的主要優(yōu)點(diǎn)是結(jié)構(gòu)簡單,造價(jià)低廉。每-工作站上都必須有從牽引車上裝卸托盤的設(shè)備,同樣,拖車的循環(huán)必

53、須是不定向的。</p><p>  2.自動(dòng)引導(dǎo)小車(AGVs)。這種運(yùn)輸車通常是設(shè)計(jì)為沿埋于車間地下的線路或沿涂敷在地面上的線路來運(yùn)行。其運(yùn)動(dòng)、轉(zhuǎn)向以及運(yùn)送托盤都需消耗運(yùn)輸車車上的能量和控制。自動(dòng)導(dǎo)引車比牽引車的造價(jià)高、體積大、同時(shí)也更重要一些。AGVs的主要優(yōu)點(diǎn)是工作柔性較大,可沿任意方向運(yùn)動(dòng),但是為便于控制;實(shí)際上這種運(yùn)輸車通常只能沿一個(gè)方向運(yùn)動(dòng)。</p><p>  3.有軌小車:

54、有軌小車在導(dǎo)軌上運(yùn)動(dòng),一般僅能沿直線導(dǎo)軌作前后運(yùn)動(dòng)。通過上部的導(dǎo)線或附加的導(dǎo)軌來傳送能量及控制指令。有軌小車通常可容納兩個(gè)托盤,從而可在系統(tǒng)的工作站上交換托盤。 </p><p>  4.滾珠式輸送器:大部分早期的FMS使用機(jī)動(dòng)的滾柱式輸送器來完成工件在系統(tǒng)工作站之間的輸送、現(xiàn)代的FMS已很少使用了。滾柱式輸送器安裝費(fèi)用較高,占用廠房空間較大。另外,其工作柔性較差,如果整個(gè)系統(tǒng)要擴(kuò)大,則很

55、難改動(dòng)。</p><p>  5.工業(yè)機(jī)器人:工業(yè)機(jī)器人可用于FMS,但除了僅由少數(shù)幾臺(tái)機(jī)床構(gòu)成的制造單元采用它外,并沒有廣泛采用。機(jī)器人也可以作為輔助傳輸裝置,特別是對(duì)于車削件,工件可分批裝在托盤上,并由其它輸送裝置控制其繞系統(tǒng)輸送,到每一工作站后再由機(jī)器人將其傳送到機(jī)床上。重要的是設(shè)計(jì)適合于在這種情況下搬運(yùn)各種了件的抓手裝置。</p><p>  2柔性封造系統(tǒng)的總體布局</p&

56、gt;<p>  FMSs已采用了各種不同的機(jī)床布局方式。選用哪種布局方式取決于該系統(tǒng)的應(yīng)用范圍及工件持送設(shè)備的類型。使用有執(zhí)小車則意味著必須使用直線導(dǎo)軌,而機(jī)床位于在該導(dǎo)軌側(cè)面。早期的柔性制造系統(tǒng)使用滾柱式輸送器,通常采用簡單的環(huán)形布置格局,其中有許多支路通向各工作站牽引車和自動(dòng)導(dǎo)引小車用得越來越多,使得柔性制造系統(tǒng)采用了更為復(fù)雜的多環(huán)路布局方式或樹形布局方式。樹形布局方式最適于使用自動(dòng)引導(dǎo)小車,可以預(yù)料,對(duì)于以增加工作

57、站來擴(kuò)展系統(tǒng)尤為有用。圖F。l 9表示了一種典型的使用牽引車的多環(huán)路布局形式,圖5.20表示了一種典型的使用自動(dòng)導(dǎo)引車輸送工件的布局方式。</p><p>  圖5.19 系統(tǒng)有8臺(tái)臥式加工中心和4 臺(tái)主軸箱更換裝置的典型牽引車布形式裝卸工件;牽引車運(yùn)輸軌道;直線式往復(fù)來回料車;計(jì)算機(jī)房;回料車更換主軸箱;計(jì)箕機(jī)房;刀具倉。</p><p>  圖5.20 典型的自動(dòng)導(dǎo)引小車的布局方式。系

58、統(tǒng)有5臺(tái)臥式加工中心、坐標(biāo)測量機(jī)、自動(dòng)托盤站和檢索系統(tǒng)以及轉(zhuǎn)盤式倉庫坐標(biāo)測量機(jī)。加工中心;自動(dòng)托盤站和檢索系統(tǒng):控制室;轉(zhuǎn)盤式倉庫;AGV軌道。</p><p>  3.柔性明造系纜中的刀具</p><p>  柔性制造系統(tǒng)若要使用大量的刀具、就勢必會(huì)限制系統(tǒng)的柔性。系統(tǒng)必紹有足夠的刀具可用于加工各種類型的零件。如前所述,系統(tǒng)配置一些相同類型的機(jī)床則可提而其柔性,但如果要使其中的任何一臺(tái)機(jī)

59、床都可加工任意工件的話,這就意味著所有的機(jī)床都必須能使用各種所需的刀具。這就要求每臺(tái)機(jī)床都帶有容量很大的刀庫,如可容納250把甚至更多刀具的刀庫。如果沒有這么大的刀庫容量,,就必須采用其他會(huì)減小系統(tǒng)總體柔性的辦法,這些措施有:</p><p>  1.讓一些機(jī)床只加工某些范圍的零件;</p><p>  2.限制加工零件子族的次數(shù),在允許的時(shí)間內(nèi)在系統(tǒng)中換刀。長遠(yuǎn)的解決辦法也許需要在系統(tǒng)中

60、采取一種可行的自動(dòng)換刀方法,但這將引起很高的額外投資和研制費(fèi)用??刹扇〉姆椒ㄓ校?lt;/p><p>  l.可互換的轉(zhuǎn)盤式刀庫;</p><p>  2.在每一工位上自動(dòng)將刀具從固定轉(zhuǎn)盤式刀庫運(yùn)至移動(dòng)圓盤傳送帶上;</p><p>  3.單獨(dú)自動(dòng)搬運(yùn)刀具和工件,并將它們一起送至每一工作站。</p><p><b>  4未來的工廠&

61、lt;/b></p><p>  根據(jù)目前機(jī)械制造技術(shù)和計(jì)算機(jī)控制技術(shù)各領(lǐng)域所取得的成就,我們可以設(shè)想未來的工廠將是無人直接參與加工車間生產(chǎn)的全自動(dòng)化工廠(即無人工廠)。所有的機(jī)械加工、材料輸送、產(chǎn)品裝配和檢測都將由自動(dòng)化的計(jì)算機(jī)控制的機(jī)械設(shè)備來完成。同樣,諸如處理新的訂單,制定生產(chǎn)計(jì)劃和調(diào)度,估算成本及作出各種決策(通常由管理部門完成)也將由計(jì)算機(jī)自動(dòng)完成。人的作用將僅限于管理、保養(yǎng)維修(尤其是預(yù)防性保

62、養(yǎng))及機(jī)床設(shè)備的改進(jìn)、接收和裝運(yùn)外來件和成品、為廠內(nèi)設(shè)備供安全保障;編制、改進(jìn)并監(jiān)控計(jì)箕機(jī)程序以及監(jiān)控、推護(hù)及改進(jìn)硬件。</p><p>  某些食品,油料和化工行業(yè)已經(jīng)實(shí)現(xiàn)了幾乎無需人工干預(yù)的自動(dòng)化生產(chǎn)。這些都是連續(xù)生產(chǎn)過程,而不是離散制造,更易于實(shí)現(xiàn)完全自動(dòng)化。即使如此,產(chǎn)品的制造過程中很明顯只有較少人工直接參與。調(diào)查表明只有! 10%~15%的勞動(dòng)力直接參與生產(chǎn)過程。而大部分勞動(dòng)力是收集和處理各種信息。&l

63、t;/p><p>  實(shí)際上,無人制造單元已用于生產(chǎn)諸如發(fā)動(dòng)機(jī)汽缸體,軸以及離合器和空氣壓縮機(jī)的外殼等產(chǎn)品。然而,大規(guī)模的柔性制造系統(tǒng)將一直需要受過良好訓(xùn)練、技術(shù)熱練的人來計(jì)劃,維護(hù)和管理生產(chǎn)。</p><p>  機(jī)床、控制系統(tǒng)和能源供給可靠性對(duì)全自動(dòng)化工廠而言是至關(guān)重要的。如果沒有及時(shí)人工干預(yù),機(jī)械裝置、計(jì)算機(jī)、能源和通訊網(wǎng)絡(luò)出現(xiàn)的局部或整體故障將破壞整個(gè)生產(chǎn)。未來的計(jì)算機(jī)集成工廠應(yīng)能在出

64、現(xiàn)這種緊急情況的時(shí)候自動(dòng)將物料和生產(chǎn)流轉(zhuǎn)送至其他機(jī)床,并在另處的計(jì)算機(jī)控制下進(jìn)行生產(chǎn)。 </p><p><b>  5對(duì)勞動(dòng)力的沖擊</b></p><p>  這樣,通常參與傳統(tǒng)制造業(yè)的低技能的直接勞動(dòng)力將轉(zhuǎn)化為間接勞動(dòng)力,他們需要經(jīng)過計(jì)算機(jī)編程、信息處理、CAD/CAM及其它高技術(shù)工作的專門培訓(xùn)和再培訓(xùn),這是計(jì)算機(jī)集成制造的基本要素。人們正在研制對(duì)用戶

溫馨提示

  • 1. 本站所有資源如無特殊說明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請(qǐng)下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請(qǐng)聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁內(nèi)容里面會(huì)有圖紙預(yù)覽,若沒有圖紙預(yù)覽就沒有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 眾賞文庫僅提供信息存儲(chǔ)空間,僅對(duì)用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對(duì)用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對(duì)任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請(qǐng)與我們聯(lián)系,我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對(duì)自己和他人造成任何形式的傷害或損失。

最新文檔

評(píng)論

0/150

提交評(píng)論