【正文】 alternative way of acplishing this function is needed, and CAPP systems are providing this alternative. CAPP is usually considered to be part of puteraided manufacturing (CAM). However, this tends to imply that CAM is a standalong system. In fact, a synergy results when CAM is bined with puteraided design to create a CAD/CAM system. In such a system, CAPP bees the direct connection between design and manufacturing. The benefits derived from puterautomated process planning include the following: ________________________________ Labor overhead at 150%= per unit Unit raw material cost = $ per unit (2) plexity of the assembled product, for example, the number of distinct ponents。 instead, they alter physical properties. Heat treating operations on metal parts are the most mon examples. Similar heating treatments are performed on glass to produce tempered glass. For most manufactured parts, these propertyenhancing operations are not required in the processing sequence.Finally finish operations usually provide a coat on the work parts (or assembly) surface. Examples included electroplating, thin film deposition techniques, and painting. The purpose of the coating is to enhance appearance, change color, or protect the surface from corrosion, abrasion, and so forth. Finishing operations are not required on many parts。 Work measurement techniques are used to set time standards for each operation.Cutting tools and cutting conditions..Methods analysis. The process must decide what tooling is required for each processing step. The actual design and fabrication of these tools is usually delegated to a tool design department and tool room, or an outside vendor specializing in that type of tool is contacted.In general, process planners must develop plans that utilize existing equipment in the plant. Otherwise, the ponent must be purchased, or an investment must be made in new equipment. The process planner must select which processes are required and their sequence. A brief description of processing steps must be prepared. The part of product design must be analyzed (materials, dimensions, tolerances, surface finished, etc.) at the start of the process planning procedure.Process Planning and Concurrent EngineeringT. Ramayah and Noraini Ismail ABSTRACTThe product design is the plan for the product and its ponents and subassemblies. To convert the product design into a physical entity, a manufacturing plan is needed. The activity of developing such a plan is called process planning. It is the link between product design and manufacturing. Process planning involves determining the sequence of processing and assembly steps that must be acplished to make the product. In the present chapter, we examine processing planning and several related topics. Process Planning Process planning involves determining the most appropriate manufacturing and assembly processes and the sequence in which they should be acplished to produce a given part or product according to specifications set forth in the product design documentation. The scope and variety of processes that can be planned are generally limited by the available processing equipment and technological capabilities of the pany of plant. Parts that cannot be made internally must be purchased from outside vendors. It should be mentioned that the choice of processes is also limited by the details of the product design. This is a point we will return to later.Process planning is usually acplished by manufacturing engineers. The process planner must be familiar with the particular manufacturing processes available in the factory and be able to interpret engineering drawings. Based on the planner’s knowledge, skill, and experience, the processing steps are developed in the most logical sequence to make each part. Following is a list of the many decisions and details usually include within the scope of process planning.超聲波清洗機(jī)的原理由超聲波發(fā)生器所發(fā)出的高頻振蕩訊號(hào)，通過換能器轉(zhuǎn)換成高頻機(jī)械振蕩而傳播到介質(zhì)清洗溶液中，超聲波在清洗液中疏密相間地向前輻射，使液體流動(dòng)而產(chǎn)生數(shù)以萬計(jì)的微量小氣泡，這些氣泡在超聲波縱向傳播成的負(fù)壓區(qū)形成、生長，而在正壓區(qū)迅速閉合，在這種被稱之為“空化”效應(yīng)的過程中氣泡閉合可形成超過1000個(gè)氣壓的瞬間高壓，連續(xù)不斷產(chǎn)生的高壓就像一連串小“爆炸”不斷的沖擊物件表面，使物件表面及縫隙中的污垢迅速剝落。而且他也許值得來結(jié)合個(gè)別裝配件的特征來減少產(chǎn)品中零件的數(shù)量。指導(dǎo)方針有時(shí)互相矛盾，一條指導(dǎo)方針是“簡化零件模型，避免不必要的特征”。 DFM/A為了理解如何設(shè)計(jì)一個(gè)既定產(chǎn)品來使可造性和可裝配性最大化也依賴于設(shè)計(jì)說明和指導(dǎo)方針的使用，這些通用設(shè)計(jì)指導(dǎo)方針中的一些幾乎適用于任何產(chǎn)品設(shè)計(jì)。這可以通過以下方法來完成：(1)通過成立由產(chǎn)品設(shè)計(jì)者制造工程師和其他員工(例如：質(zhì)量工程師、材料專家)組成的攻關(guān)小組來進(jìn)行產(chǎn)品開發(fā)；(2)通過要求設(shè)計(jì)工程師用一些事業(yè)時(shí)間在制造上，以能夠掌握第一手可造性和可裝配性是如何通過產(chǎn)品設(shè)計(jì)聯(lián)系在一起的；(3)通過指派制造工程師到產(chǎn)品設(shè)計(jì)部門在一個(gè)臨時(shí)的或?qū)Ｈ蔚幕A(chǔ)上做一個(gè)還原性顧問。.在DFM/A中的組織變化.當(dāng)然，DFM和DFA是緊密相連的，因此讓我們用制造和裝配設(shè)計(jì)(DFM/A)的形式來表達(dá)。因此，當(dāng)產(chǎn)品設(shè)計(jì)展開時(shí)給制造工程師一個(gè)忠告設(shè)計(jì)者的機(jī)會(huì)對(duì)產(chǎn)品的順利可造性是非常重要的。例如，如果產(chǎn)品設(shè)計(jì)者決定用鋁砂型鑄造法制造一個(gè)分開零件，但是這個(gè)零件的工藝特性只能通過加工來完成(如螺紋孔和配合公差)，制造工程師沒有選擇的余地，只能按照先砂型鑄造在加工的方法來達(dá)到既定要求。制造和裝配設(shè)計(jì)據(jù)估計(jì)一件產(chǎn)品的70%的生命周期成本是由在產(chǎn)品設(shè)計(jì)時(shí)所做的基本決定所決定的，這些設(shè)計(jì)決定包括每個(gè)零件的材料、零件模型、公差、表面處理、零件是如何被組織裝配的和常用裝配方法。并行設(shè)計(jì)包含以下因素：(1)一些制造和裝配設(shè)計(jì)(2)質(zhì)量設(shè)計(jì)(3)成本設(shè)計(jì)和(4)生命周期設(shè)計(jì)。在產(chǎn)品發(fā)展階段的所有這些功能不僅能改善新產(chǎn)品的功能和性能，同時(shí)也能改善他的可造性、自檢性、易測性、服務(wù)能力和可維護(hù)性。他同樣為產(chǎn)品提供制造計(jì)劃繼續(xù)進(jìn)行的早期準(zhǔn)備，這種并行工程的路徑在圖(1)b中被描繪出。 比較 : (a) 傳統(tǒng)產(chǎn)品發(fā)展周期和 (b) 并行產(chǎn)品的發(fā)展周期通過比較，實(shí)行并行工程的公司，工程制造部門在早期就參與到產(chǎn)品發(fā)展周期。他好像消除了在設(shè)計(jì)和制造之間的一堵墻，當(dāng)設(shè)計(jì)部門完成設(shè)計(jì)，他投擲工程圖和說明書越過這面墻，并且那時(shí)工藝規(guī)程制訂也開始了。制造業(yè)的并行工程和設(shè)計(jì)并行工程引用一種常用于產(chǎn)品發(fā)展的路徑，通過它使工程設(shè)計(jì)功能、工程制造功能和其他功能綜合起來以減少一種新產(chǎn)品投放市場所需要的共用時(shí)間，也被稱為并發(fā)工程，他可能被認(rèn)為是CAD/CAM技術(shù)的類似組織版本，按照傳統(tǒng)路徑來使一件產(chǎn)品投放市場。計(jì)算機(jī)輔助工藝圍繞著兩個(gè)路徑來設(shè)計(jì)，這兩個(gè)路徑被叫做：（1）CAPP檢索系統(tǒng)和（2）CAPP生成系統(tǒng)。 .結(jié)合其他應(yīng)用軟件. 計(jì)算機(jī)準(zhǔn)備的進(jìn)路表比手工準(zhǔn)備的進(jìn)路表更容易簡潔。 .減少工藝規(guī)程的制訂時(shí)間. 在數(shù)據(jù)文件中的系統(tǒng)方法和標(biāo)準(zhǔn)加工設(shè)計(jì)的實(shí)用性使工藝制訂者可完成更多的工作。 自動(dòng)工藝規(guī)程制訂比完全用手工編制工藝產(chǎn)生的更合理化和一致化。來自計(jì)算機(jī)輔助工藝的優(yōu)點(diǎn)包括以下幾點(diǎn)： 事實(shí)上，當(dāng)CAD和計(jì)算機(jī)輔助設(shè)計(jì)協(xié)同作用創(chuàng)造了一個(gè)CAD/CAM系統(tǒng)。CAPP經(jīng)常被看作是計(jì)算機(jī)輔助制造（CAM）的一部分。那些熟悉加工詳細(xì)資料和其他工藝的工廠培訓(xùn)的工人逐漸退休，并且這些人在將來工藝制訂的過程中是非常有用的。由此我們將引出并行工程。制造或購買決定并不像這個(gè)例子中的那樣直接。通過這種推理，如果應(yīng)該已用于生產(chǎn)零件的設(shè)備閑置的購買決定并不是一個(gè)好決定因?yàn)樗赡芑ㄙM(fèi)公司將近$+$+$=$。$，如果設(shè)備設(shè)計(jì)因?yàn)橘徺I零件的決定而變的沒有利用價(jià)值，那么這個(gè)固定成本仍然繼續(xù)盡管設(shè)備閑置著。為一個(gè)特定零件被引述的價(jià)格是100個(gè)單位的每單位$。可是，如果購買決定導(dǎo)致公司工廠設(shè)備和勞動(dòng)的閑置，購買零件的表面優(yōu)勢就會(huì)喪失。這里有許多影響制造或購買決定的因素，一個(gè)人可能認(rèn)為成本是決定是購買還是制造零件的最重要的因素。很少的公司能夠在操作中從原料一直進(jìn)行垂直整合，這看來至少購買一些也許在他的工廠可以另外制造的零件是合理的。一個(gè)塑料成型廠從一個(gè)化工廠購買他的模塑料。在我們的關(guān)于制造或購買的決定的討論中，他應(yīng)該認(rèn)識(shí)到在開始幾乎所有的制造者從供應(yīng)商那里購買原料。因?yàn)闆]有其他選擇零件必須購買。制造或購買決定在工藝制定過程中出現(xiàn)的一個(gè)重大問題是一個(gè)特定零件應(yīng)該在公司內(nèi)部的工