裝配圖柴油機(jī)氣缸體頂?shù)酌娲帚娊M合機(jī)床總體及夾具設(shè)計
裝配圖柴油機(jī)氣缸體頂?shù)酌娲帚娊M合機(jī)床總體及夾具設(shè)計,裝配,柴油機(jī),缸體,底面,組合,機(jī)床,總體,整體,夾具,設(shè)計
外文翻譯
專 業(yè) 機(jī)械設(shè)計及自動化
學(xué) 生 姓 名 陶 金 丞
班 級 B機(jī)制023班
學(xué) 號 0210110333
指 導(dǎo) 教 師 劉 道 標(biāo)
柔性制造
陶金丞譯
摘要:
在制造中,生產(chǎn)率和柔性之間經(jīng)常存在協(xié)調(diào)一致的問題。在該領(lǐng)域的一端是具有高生產(chǎn)率卻低柔性的連續(xù)生產(chǎn)線;在該領(lǐng)域的另一端是能提供最大柔性的獨(dú)立的計算機(jī)數(shù)字控制的機(jī)床,但它只能進(jìn)行低生產(chǎn)率的制造。柔性制造出在此連續(xù)統(tǒng)一體中間。在制造中總是需要一個系統(tǒng),這個系統(tǒng)比單個機(jī)床能制造更大批量且用于更多制造過程,但仍保持起柔性。
關(guān)鍵詞:柔性制造、協(xié)調(diào)一致
柔性制造的定義:
計算機(jī)集成制造的前一部叫做柔性制造。
柔性在現(xiàn)在帶制造環(huán)境中是一個重要的特征。它意味著一個制造系統(tǒng)是用途多且適應(yīng)性強(qiáng),同時又能進(jìn)行產(chǎn)量相對較大的制造。柔性制造系統(tǒng)是多用途的,這是因為它能制造多種多樣的部件。它適應(yīng)性強(qiáng),因為它能很快地加以改變來制造完全不同的另一種部件。這種柔性在競爭激烈的國際市場上可能成敗有別。
這是一個平衡的問題。獨(dú)立的計算機(jī)數(shù)字控制(NC)機(jī)床有著高度的柔性,但是只能處理批量相對較小的制造。正相反,系列連續(xù)生產(chǎn)線能進(jìn)行批來年感較大的制造,但都不靈活。柔性制造試圖運(yùn)用工業(yè)技術(shù)在靈活性與制造運(yùn)行之間達(dá)到最佳的平衡。這些工業(yè)技術(shù)包括自動化的材料、處理、成組技術(shù)及計算機(jī)和分布數(shù)字控制。
柔性制造系統(tǒng)(FMS)是一個獨(dú)立的機(jī)床或一組機(jī)床服務(wù)于一個自動材料處理系統(tǒng)/它是由計算機(jī)控制的而且有對刀具處理的能力。由于它有刀具處理能力并能受計算機(jī)控制,這樣的系統(tǒng)可以不斷地重新配置來制造更加多樣的部件,這就是它被稱作柔性制造系統(tǒng)的原因。
一個制造系統(tǒng)要成為柔性制造系統(tǒng)必須具備的要素有:
1. 計算機(jī)控制
2. 自動處理材料能力
3. 刀具處理能力
柔性制造向全面集成化制造的目標(biāo)邁進(jìn)了重要的一步。它實(shí)現(xiàn)了自動化制造過程的集成化。在柔性制造中,自動化的制造機(jī)器(如車床、銑床、鉆床)和自動化材料處理系統(tǒng)之間,通過計算機(jī)網(wǎng)絡(luò)進(jìn)行即時的溝通。
柔性制造的概況:
通過綜合幾個自動化的制造概念,柔性制造系統(tǒng)全面集成化的制造目標(biāo)邁出了重要的一步,這些觀念是:
1. 獨(dú)立機(jī)床的計算機(jī)數(shù)字控制
2. 制造系統(tǒng)的分布式數(shù)字控制
3. 自動化的材料處理系統(tǒng)
4. 成組技術(shù)
當(dāng)這些自動化工藝、機(jī)器和觀念合成到一個集成的系統(tǒng)時,就產(chǎn)生柔性制造系統(tǒng)。在柔性制造系統(tǒng)中,人和計算機(jī)起了重要作用。當(dāng)然人的勞動量比手工操作的制造系統(tǒng)要小得多。然而,人仍然在柔性制造系統(tǒng)的操作中起著至關(guān)重要的作用。人的任務(wù)包括幾個方面:
1. 設(shè)備故檢、維護(hù)和修理
2. 刀具的變換和設(shè)置
3. 安裝和拆卸系統(tǒng)
4. 數(shù)據(jù)輸入
5. 部件程序的變換
6. 程序的開發(fā)
柔性制造制系統(tǒng)設(shè)備象所有制造設(shè)備一樣,必須友人監(jiān)管以免出現(xiàn)失常、機(jī)器程序錯誤,以及故障。當(dāng)發(fā)現(xiàn)問題時檢修人員必須確定問題的根源,然后給出正確的措施。人還要采取指定的措施來維修運(yùn)行不正常的機(jī)器。甚至當(dāng)所有系統(tǒng)都正 常運(yùn)行時,定期的維護(hù)也是必要的。
操作人員還要根據(jù)需要設(shè)置機(jī)床,換刀具、以及重新配置系統(tǒng)。柔性制造系統(tǒng)的刀具處理能力削弱了,但并有消除,在刀具變換和設(shè)置上仍需要人力。在裝卸柔性制造系統(tǒng)時也是這樣。一旦原材料被送到自動化材料處理系統(tǒng)上,它就會以規(guī)定的方式,在系統(tǒng)中移動。然而,初裝到材料系統(tǒng)處理系統(tǒng)仍然是由操作人員完成的;成品的拆卸也是同樣。
與計算機(jī)的交流仍需人力完成。人開發(fā)零件程序,通過計算機(jī)控制柔性制造系統(tǒng)。當(dāng)重新配置FMS制造另一種類型零件時,他們還在必要的時候變換程序。人在柔性制造系統(tǒng)中勞動力密集型的成分越來越少,但仍然是很重要的。
柔性制造系統(tǒng)中的各層次控制都是由計算機(jī)來完成的。在刀具柔性制造系統(tǒng)中獨(dú)立的機(jī)床是由CNC來控制的。整個的系統(tǒng)是由DNC來控制的。自動化的材料處理系統(tǒng)是由計算機(jī)來控制的,其他功能如數(shù)據(jù)收集、系統(tǒng)監(jiān)控、刀具控制、運(yùn)輸控制也是計算機(jī)控制的。人機(jī)交互是柔性制造系統(tǒng)中的關(guān)鍵。
柔性制造的歷史發(fā)展:
柔性制造產(chǎn)生于20世紀(jì)60年代中期,當(dāng)時英國莫林斯有限公司開發(fā)了24號系統(tǒng)。24系統(tǒng)是一個真正的FMS。然而,它從一開始就注定是失敗的,因為自動化、集成和計算機(jī)控制技術(shù)還沒有發(fā)展到能夠恰好支持這一系統(tǒng)的程度。第一個FMS是超遷的開發(fā)。因此,最終因不能工作餓被放棄。
再20世紀(jì)60年代和70年代的期于時間里,柔性制造仍是一個學(xué)術(shù)觀念。然而,隨著復(fù)雜計算機(jī)控制技術(shù)在20世紀(jì)70年代末和80年代初的出現(xiàn),柔性制造變成為可能。在美國最初的主要用戶是汽車、卡車和拖拉機(jī)制造商。
柔性制造的理由:
在制造中,生產(chǎn)率和柔性之間經(jīng)常存在協(xié)調(diào)一致的問題。在該領(lǐng)域的一端是具有高生產(chǎn)率卻低柔性的連續(xù)生產(chǎn)線;在該領(lǐng)域的另一端是能提供最大柔性的獨(dú)立的計算機(jī)數(shù)字控制的機(jī)床,但它只能進(jìn)行低生產(chǎn)率的制造。柔性制造出在此連續(xù)統(tǒng)一體中間。在制造中總是需要一個系統(tǒng),這個系統(tǒng)比單個機(jī)床能制造更大批量且用于更多制造過程,但仍保持起柔性。
連續(xù)生產(chǎn)線能以高生產(chǎn)率制造大量的零件。這條生產(chǎn)線需要大量的準(zhǔn)備工作,但卻能造出大量的相同的零件。它的主要缺點(diǎn)是即使一個部件雜設(shè)計上有小的改變都能造成整個生產(chǎn)線的停產(chǎn)和結(jié)構(gòu)改變。這是一個致命的弱點(diǎn),因為這意味著沒有高成本,耗時停工和變化生產(chǎn)線結(jié)構(gòu)是不能制造出不同的零件的,即使是來自同一個零件族。
傳統(tǒng)上計算機(jī)數(shù)字控制機(jī)床是用來制造少量在設(shè)計上稍有不同的零件。這種機(jī)床很適合這一用途,因為它們能迅速地改變程序開適應(yīng)設(shè)計上小的或者更大的變化。然而,作為獨(dú)立的機(jī)床它們不能大量地或高生產(chǎn)率地制造零件。
柔性制造系統(tǒng)比獨(dú)立的計算機(jī)數(shù)控機(jī)床具有更大的生產(chǎn)能力和更高的生產(chǎn)率。它們在柔性方面比不上計算機(jī)數(shù)字控制機(jī)床,但它們卻相差不多,柔性制造的中間性能的特殊意義在于大多數(shù)鑄造要求中等量的的生產(chǎn)率來制造中等量的產(chǎn)品,同時有足夠的的柔性以快速改變結(jié)構(gòu)來制造另一個零件或產(chǎn)品。柔性制造填補(bǔ)了制造中長期存在的空白。
柔性制造以其基本能力給制造者提供了許多優(yōu)點(diǎn):
1. 族內(nèi)具有柔性在一個零件
2. 隨意進(jìn)給零件
3. 同時制造不同的零件
4. 準(zhǔn)備時間和產(chǎn)品設(shè)計到投產(chǎn)的時間減少了
5. 機(jī)床的使用更有效
6. 直接和見解的人力成本減少
7. 能加工不同的材料
8. 如一臺機(jī)床故障能繼續(xù)進(jìn)行部分生產(chǎn)
柔性制造系統(tǒng)的軟件:
軟件是驅(qū)動柔性制造系統(tǒng)的主要的不可件的因素。FMS所要求的軟件有兩個基本的層次:1.操作系統(tǒng)軟件和2.應(yīng)用系統(tǒng)軟件。操作系統(tǒng)軟件是最高層次,是計算機(jī)制造商特別規(guī)定的并對應(yīng)用軟件進(jìn)行監(jiān)督控制。應(yīng)用軟件通常是由系統(tǒng)供應(yīng)商開發(fā)和提供的,它包口所有的FMS的特定程序和例行程序。
FMS的應(yīng)用軟件是很復(fù)雜的,而且具有很強(qiáng)的專利性質(zhì)。對于很多公司來說,它體現(xiàn)了幾百名工人很多年開發(fā)努力的結(jié)晶。它通常是由幾個模塊組成。每個模塊又是有由一系列與系統(tǒng)內(nèi)部運(yùn)行的各種功能相關(guān)的計算機(jī)沉痼系和例行程序組成。這些包括從FMS主機(jī)下載的NC部分程序到機(jī)床控制器、運(yùn)輸和材料順序的開發(fā)、工件的工序、模擬和刀具管理。所有這些軟件模塊必須得到很好的餓設(shè)計,并且能夠可預(yù)測地、可靠地、相互作用地運(yùn)行以便FMS能達(dá)到最高的運(yùn)行效率和可接受的水平。設(shè)計不好的軟件使制造商不能獲得FMS的充分的柔性和潛能。
由于FMS軟件是柔性制造系統(tǒng)的命脈,它也是一個FMS的最復(fù)雜、最難以理解和在戰(zhàn)略上重要的方面。如果構(gòu)件和編碼得恰當(dāng),進(jìn)行了反復(fù)地測試,并且充分地運(yùn)行的話,它可以使FMS達(dá)到前所未有的生產(chǎn)性能水平。應(yīng)補(bǔ)充說一句,所有完成的FMS軟件只有在客戶的工廠中、完全運(yùn)行中對該系統(tǒng)徹底的檢查后,才能被認(rèn)為是可接受的。
軟件設(shè)計的模塊化并不一定以為著使用相同或類似的軟件模塊的所有都是一樣的。很多FMS用戶有特殊的和內(nèi)行才懂的各種要求來適應(yīng)于他們自己的應(yīng)用和操作考慮。這樣的一些要求可能會包括特殊的FMS軟件模塊來連接一個新的FMS和已存在的自動存儲和檢索系統(tǒng)?;蛘?,使FMS從主機(jī)上直接接受生產(chǎn)要求和零件工序信息。
總之,像其他計算機(jī)軟件一樣,F(xiàn)MS軟件,就像開發(fā)和為之編碼的人一樣,獨(dú)立而各具特點(diǎn)。重要的是生產(chǎn)環(huán)境下它能做什么并運(yùn)行得如何。
Flexible Manufacturing
Abstract:
In manufacturing there have always been tradeoffs between production rates and flexible. At one end of the spectrum are transfer lines capable of high production rates, but low flexible. At the other end of the spectrum are independent CNC machines that offer m aximum flexible, but are capable only of low production rates. Flexible manufacturing falls in the middle of the continuum. There has always been need in manufacturing for a system that could produce higher volume and production runs than could independent machines, while still maintaining flexibility.
Key words: flexible manufacturing, tradeoffs
Flexible Manufacturing Defined
The step preceding computer-integrated manufacturing is called flexible manufacturing.
Flexible is an important characteristic in the modern manufacturing setting. It means that a manufacturing system is versatile and adaptable, while also capable of handling relatively high production runs. A Flexible manufacturing system is versatile in that it can produce a variety of parts. It is adaptable because it can be quickly modified to produce a completely different line of parts. This flexible can be the difference between success and failure in a competitive international marketplace.
It is a matter of balance. Stand-alone computer numerical control machines have a high degree of flexibility, but are capable of relatively low-volume production runs. As the opposite end of spectrum transfer lines are capable of high-volume runs, but they are not very flexible. Flexible manufacturing is an attempt to use technology in such a way as to achieve the optimum balance between flexibility and production runs. These technologies include automated materials, handing, group technology, and computer and distributed numerical control.
A flexible manufacturing system (FMS) is an individual machine or group of machines served by an automated materials handing system that is computer controlled and has a tool handing capability. Because of its tool handling capability and computer control, such a system can be continually reconfigured to manufacture a wide variety of parts. This is why it is called a flexible manufacturing system.
The key elements necessary for a manufacturing system to qualify as an FMS are as follows:
1. Computer control
2. Automated materials handling capability
3. Tool handling capability
Flexible manufacturing represents a major step toward the goal of fully integrated manufacturing. It involves integration of automated production processes. In flexible manufacturing, the automated manufacturing machine (i.e., lathe, mill, dill) and the automated materials handling system share instantaneous communication via a computer network. This is integration on a small scale.
Overview of Flexible Manufacturing
Flexible manufacturing takes a major step toward the goal of fully integrated manufacturing by integrating several automated manufacturing concepts:
1. Computer numerical control (CNC) of individual machine tool
2. Distributed material control (DNC) of manufacturing systems
3. Automated materials handling systems
4. Group technology (families of parts)
When these automated processes, machines, and concepts are brought together in one integrated system, an FMS is the result. Humans and computers play major roles in an FMS. The amount of human labor is much less than with a manually operated manufacturing system, of course. However, humans still play a vital role in the operation of an FMS. Human tasks include the following.
1. Equipment troubleshooting, maintenance, and repair.
2. Tool changing and setup.
3. Loading and unloading the system.
4. Data input.
5. Changing of parts programs.
6. Development of programs.
Flexible manufacturing system equipment, like all manufacturing equipment, must be monitored for bugs, malfunctions, and breakdowns. When a problem is discovered, a human troubleshooter must identify its source and prescribe correctives measures. Humans also undertake the prescribed measures to repair the malfunctioning equipment. Even when all systems are properly functioning, periodic is necessary.
Human operators also set up machines, change tools, and reconfigure systems as necessary, The tool handling capability of an FMS decreases, but does not eliminate, human involvement in tool changing and setup. The same is true of loading and unloading the FMS. Once raw material has been loaded onto the automated materials handling system, it is moved through the system in the prescribed manner. However, the original loading onto the materials handling system is still usually done by human operators, as is the unloading of finishes products.
Humans are also needed for interaction with the computer. Humans develop parts programs that control the FMS via computers. They also change the programs as necessary when reconfiguring the FMS to produce another type of part or parts. Humans play less labor-intensive roles in an FMS, but the roles are still critical.
Control at all levels in an FMS is provided by computers. Individual tools within an FMS are controlled by CNC. The overall system is controlled by DNC. The automated materials handling system is computer controlled, as are other functions including data collection, system monitoring, tool control, and traffic control. Human computer interaction is the key to the flexibility of an FMS.
Historical Development of Flexible Manufacturing
Flexible manufacturing was born in the mid-1960s when the British firm Molins, Ltd. developed its System 24. System24 was a real FMS. However, it was doomed from the outset because automation, integration, and computer control technology had not yet been developed to the point where they could properly support the system. The first FMS was a development that was ahead of its time. As such, it was eventually discarded as unworkable.
Flexible manufacturing remained an academic concept through the remainder of the 1960s and 1970s. However, with the emergence of sophisticated computer control technology on the late 1970s and early 1980s, flexible manufacturing became a viable concept. The first major users of flexible manufacturing in the United States were manufacturing if automobiles, trucks, and tractors.
Rationale for Flexible Manufacturing
In manufacturing there have always been tradeoffs between production rates and flexible. At one end of the spectrum are transfer lines capable of high production rates, but low flexible. At the other end of the spectrum are independent CNC machines that offer maximum flexible, but are capable only of low production rates. Flexible manufacturing falls in the middle of the continuum. There has always been need in manufacturing for a system that could produce higher volume and production runs than could independent machines, while still maintaining flexibility.
Transfer lines are capable of producing large volumes of parts at high production rates. The line takes a great deal of setup, but can turn out identical parts in large quantities. Its chief shortcoming is that even minor design changes in a part can cause the entire line to be shut down and reconfigured. This is a critical weakness because it means that transfer lines cannot produce different parts, even parts from within the same family, without costly and time-consuming shutdown ad reconfiguration.
Traditionally, CNC machines have been used to produce small volumes of parts that differ slightly in design. Such machines are ideal for this purpose because they can be quickly reprogrammed to accommodate minor or even major design changes. However, as independent machines they cannot produce parts in large volumes or at high production rates.
An FMS can handle higher volumes and production rates than independent CNC machines. They cannot quite match such machines for flexible, but they come close. What is particularly significant about the middle ground capabilities of flexible is that most manufacturing situations require medium production rates to produce medium volumes with enough flexibility to quickly reconfigure to produce another part or product. Flexible manufacturing fills this long-standing void in manufacturing.
Flexible manufacturing, with its ground capabilities, Flexible offers a number of advantages for manufacturers:
1. Flexible within a family of parts.
2. Random feeding of parts.
3. Simultaneous production of different parts.
4. Decreased setup time and lead time.
5. More efficient machine usage.
6. Decreased direct and indirect labor costs.
7. Ability to handle different materials.
8. Ability to continue some production if one machine breaks down.
FMS Software
Software is the vital invisible element that actually drives the FMS. There are basic levels of software required for an FMS: 1.operating system; 2.application software. Operating system software is the highest lever, is computer manufacturer specific, and executes supervisory control over the application software. Application software is usually developed and supplied by the system supplied and includes all the FMS specific programs and routines.
Application software for an FMS is complex, highly proprietary, and for many companies, represents several hundred worker-years of development effort. Generally, it is composed of several modules, each of which is made up of a series of computer programs and routines relating to various functions performed within the system. These include NC part programs download from the FMS host computer to machine tool controllers, traffic and material-handling management, work-order generation, work piece scheduling, simulation, and tool management. All these software modules must be well designed and function predictably, reliably, and interactively in order fir the FMS to perform at peak operating efficiencies and acceptable levels. Poorly designed software prevents manufacturers form achieving the full flexibility and potential capacity of FMS.
FMS software, because it is the life blood of a flexible manufacturing system, is also the most complex, least understood, and strategically important aspect of an FMS. Structures and coded properly, tested rigorously, and functioning adequately, it can make an FMS productive at unprecedented performance levels. It should be added that all completed FMS software can only be considered acceptable after it has been thoroughly checked out with the system in complete operation in the customer’s plant.
Modularity of software design does not necessarily imply that all system using the same or similar software modules are created equal. Many FMS users have highly specific and esoteric requirements to suit their own applications and operating concerns. Some of these might include specific FMS software modules to couple an already existing automatic storage and retrieval system (ASRS) to a new FMS or to have the FMS directly receive production requirements and part scheduling information from the host computer.
Overall, FMS software, like other types of computer software, is as different and autonomous as the people who develop and code it. What counts is what it does and how well it performs in a manufacturing environment.
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