外文翻譯--工序制訂與并行工程

1、<p>　　畢業(yè)設計外文資料翻譯</p><p><b>　　系　　部： </b></p><p><b>　　專 業(yè)： </b></p><p><b>　　姓 名： </b></p><p>　　學 號： </p><p&

2、gt;　　外文出處： Process Planning and Concurrent Engineering </p><p>　　附 件： 1.外文資料翻譯譯文；2.外文原文。 </p><p>　　附件1：外文資料翻譯譯文</p><p><b>　　工序制訂與并行工程</b></p><p>　　產(chǎn)品設計是用

3、于產(chǎn)品，及它的部件裝配的計劃。為了把產(chǎn)品設計轉化成一個實際存在的物體，這需要一個制造計劃。而制訂一個這樣的計劃的行動就叫做工序制訂。它是產(chǎn)品設計和制造之間的連接。工序制訂包括決定加工順序和制造產(chǎn)品所必須完成的裝配步驟。在這篇文章中，我們將對工序制訂和他的一些相關的主題進行解釋。</p><p>　　首先，我們應該區(qū)別在這篇文章中被反復提到的工序制訂和生產(chǎn)計劃。工序制訂與如何制造產(chǎn)品和它的零件等工程技術問題有關。制

4、造零件和裝配產(chǎn)品需要什么樣的設備和工具？工序制訂與產(chǎn)品制造物流管理有關系。它在工序制訂后面與原料分類及獲得滿足制造充分數(shù)量產(chǎn)品要求的資源有關。</p><p><b>　　工序制訂</b></p><p>　　工序制訂包括決定最適當?shù)闹圃旒把b配步驟和順序，可計劃的工序范圍和多樣性通常由于公司車間可用設備和技術能力而受到限制。在公司內部不能夠制造的零件必須到外部市場購買

5、。工序制訂所提及的工序選擇同樣也受到詳細設計資料的限制。我們稍后將會回到這一點。</p><p>　　工序制訂通常是由制造工程師完成的。（工業(yè)工程師擁有其他權利。）工序制訂者必須熟悉工廠中詳細可用的制造流程并且能夠說明工程圖?；谥朴喺叩闹R，技術和經(jīng)驗，用于制造每個零件的工序步驟以最合乎邏輯的順序被發(fā)展制訂。下列各項是在工序制訂范圍里的許多決定和詳細資料：</p><p>　　.設計圖的

6、說明. 在工序制訂的開始，產(chǎn)品設計的這一部分（材料、尺寸、公差、表面處理、等等）必須進行分析。</p><p>　　.工序和順序. 工序制訂者必須選擇哪一個工序是必需的及必需工序的序列。此外還必須準備好一個簡短的工序步驟描述。</p><p>　　.設備選擇. 大體上，工序制訂者必須逐步展開利用工廠現(xiàn)有機器的計劃。另外，組件必須被購買或在新設備上的投資必須被制定。</p>

7、<p>　　.工具、沖模、鑄模、夾具、量具. 工序必須決定每個工序需要什么工具。這些工具的實際設計和制造通常通過委派工具設計部門和工具庫或者聯(lián)系專攻那種工具制造的外面廠商來完成。</p><p>　　.方法分析. 車間規(guī)劃、小工具、提升重物的提升間、甚至在一些人工操作情景中的肢體動作也被指定。</p><p>　　.操作步驟. 工作測量技術被用來為每個操作設定時間標準。

8、</p><p>　　.切削工具和切削條件. 這些必須對加工操作通過推薦標準手冊來進行詳細說明。</p><p><b>　　零件工序制訂</b></p><p>　　對于單個零件，加工順序通過一種被稱為進路表的表格來進行文件證明備份。 （不是所有的公司使用進路表這個名字；另外的一個名字是“操作說明書?！保┚腿绻こ虉D被用于詳細說明產(chǎn)品設計一樣

9、，進路表被用于詳細說明工序計劃。他們是類似的，一個用于產(chǎn)品設計，另一個用于制造。典型的進路表，如圖21.1 中舉例，包括下列信息：（1）所有工作部分要執(zhí)行的操作都按照他們應當被執(zhí)行的順序列出來；（2）一個指出關于零件圖尺寸公差必須完成加工的每個操作的簡短描述；（3）用于完成這個操作的特定設備；（4）象沖模，鉆模，切削刀具，鉆夾具或夾具，和量具這樣的特定工具。一些公司還包括時間設置，周期標準和其他數(shù)據(jù)。他被稱為進路表是因為工序順序規(guī)定了零

10、件在工廠中必須遵循的路線。如表21-1中，列出了在準備一個進路表時所需要的一些指導方針。</p><p>　　圖 21.1 詳細說明工序計劃的典型進路表</p><p>　　表21-1 準備一個進路表的典型指導方針</p><p>　　圖21.2 在零件制造中的典型工序順序</p><p>　　制造單個零件的典型加工順序包括：（1）一個基本

11、工序，（2）二級工序，（3） 提高物質特性工序，和（3）最后工序。在圖21.2中顯示了這種序列。一個基本工序決定了工件的起始造型。金屬鑄件，塑料成型，金屬精煉是基本工序中的實例。 起始造型常常必須通過改變起始造型操作（或者接近于最終造型）的二級工序來精制。二級工序習慣于和基本工序一起提供起始造型。當砂型鑄造是基本工序，車加工通常是二級工序。當軋鋼廠制造金屬片是基本工序，沖壓操作象沖裁和彎曲通常是二級工序。當塑料注入成型是基本工序時，二級

12、工序通常是不必要的，因為他的大多數(shù)幾何特征制造通過別的方式如成型制造來完成。塑料成型和其他操作的二級工序被稱為凈成型工序的并發(fā)二級工序。需要一些但并不多的二級工序的操作就是所提到的近似凈成型工序。許多有印象的摸鍛件就是這一類。這類零件能夠經(jīng)常在鍛造（初級工序）階段被成型，因此減少了必要的加工（二級工序）。</p><p>　　一旦模型被建立，許多零件的下一步是改良它們的機械物理性能。提高特性工序并不改變零件模型，

13、然而，它卻能改變零件的物理特性。金屬零件的熱處理操作就是最普通的實例。類似的如玻璃通過熱處理來制造鋼化玻璃。對于大多數(shù)零件的制造來說，這些特性加強工序如在圖21.2指出的可選擇路徑那樣在加工工序中并不需要。</p><p>　　最后工序通常對零件（或裝配體）的表面提供一個涂層。例如電鍍，薄膜沉積技術，涂漆。表面處理的目的是改善外觀，改變顏色，或者表面保護防止腐蝕和磨損等等。在很多零件中最后工序是并不需要的；例如，

14、塑料成型就很少需要最后程序。當必須需要最后程序，他通常是加工順序的最后一步。表21-2列出了一些普通原料加工的典型加工順序：</p><p>　　表21-2 一些典型加工順序</p><p><b>　　裝配工序制訂</b></p><p>　　一個既定產(chǎn)品的典型裝配方法由以下因素決定的：（1）預期產(chǎn)品數(shù)量；（2）裝配產(chǎn)品的復雜性，例如，不同

15、組件的數(shù)量；和（3）常用裝配工序，例如，機械定位焊接。對于小數(shù)量產(chǎn)品，通常在人工裝配線上進行裝配。對于大量制造的一打或這樣組件的簡單零件，要采用適當?shù)淖詣踊b配線。無論如何，這里有一個工作必須被完成的優(yōu)先順序。這個優(yōu)先需求經(jīng)常用一個優(yōu)先表來進行圖表描繪。</p><p>　　裝配工序制訂包括裝配指令的發(fā)展，但是更詳細地，對于小批量生產(chǎn)，在一個崗位完成整個裝配。對于一個裝配線上的大批量生產(chǎn)，工序制訂由一種分配工作條

16、件到裝配線個別工位并被叫做人工投入線性平衡法的程序組成。這種裝配線按照裝配線平衡解決方案決定的順序發(fā)送工作單元到個別工位。在個別組成，任意工具或夾具的工序制訂時，一條裝配線的決定，設計，和制造必須被完成,并且工作站的必須被列出來。</p><p><b>　　制造或購買決定</b></p><p>　　在工序制定過程中出現(xiàn)的一個重大問題是一個特定零件應該在公司內部的工

17、廠內生產(chǎn)還是從外部銷售商處購買，并且這個問題的答案被認為是制造或購買決定。如果公司沒有技術設備或制造零件所必須的詳細制造工序中的專門技術，那么答案就很明顯了：因為沒有其他選擇零件必須購買。然而，在很多例子中，零件既可以在利用現(xiàn)有設備在內部制造或者可以從外部擁有相似制造能力的生產(chǎn)銷售商處購買。</p><p>　　在我們的關于制造或購買的決定的討論中，他應該認識到在開始幾乎所有的制造者從供應商那里購買原料。一個機械

18、加工廠從一個金屬經(jīng)銷商購買他的起動柄原料或從一個鑄造廠購買他的砂型鑄件。一個塑料成型廠從一個化工廠購買他的模塑料。一個沖壓廠可以去經(jīng)銷商或直接從軋鋼廠購買金屬片。很少的公司能夠在操作中從原料一直進行垂直整合，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。也有可能為公司使用的每一個組成要求制造或購買決定。</p><p>　　這里有許多影響制造或購買決定的因素。在表21-3中列出一列影響決定的因素和結

19、果。一個人可能認為成本是決定是購買還是制造零件的最重要的因素。如果一個外部經(jīng)銷商比公司工廠更精通于制造零件的工序，因而公司內部生產(chǎn)成本可能比經(jīng)銷商賺取成本后的價格還要高。可是，如果購買決定導致公司工廠設備和勞動的閑置，可是購買零件的表面優(yōu)勢就會喪失?？紤]以下例子，例21.1制造或購買決定</p><p>　　為一個特定零件被引述的價格是100個單位的每單位$20.00。制造零件的成分如下所示：</p>

20、<p>　　單位原料成本=每單位$8.00</p><p>　　直接勞動成本=每單位6.00</p><p>　　勞動加班150%=每單位9.00</p><p>　　設備修理成本=每單位5.00</p><p>　　總計=每單位28.00</p><p>　　表21-3制造或購買決定因素</p&g

21、t;<p><b>　　附件2：外文原文</b></p><p>　　Process Planning and Concurrent Engineering</p><p>　　The product design is the plan for the product and its components and subassemblies.To co

22、nvert 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 plannin

23、g involves determining the sequence of processing and assembly steps that must be accomplished to make the product .In the present chapter ,we examine processing planning and several related </p><p>　　At the

24、 outset ,we should distinguish between process planning and production planning ,which is covered in the following chapter. Process planning is concerned with the engineering and technological issues of how to make the p

25、roducts and its parts. What types of equipment and tooling are required to fabricate the parts and assemble the product ? Production planning is concerned with the logistics of making the product .After process planning

26、is concerned with ordering the materials and obtaining</p><p>　　Process Planning </p><p>　　Process planning involves determining the most appropriate manufacturing and assembly processes and the

27、 sequence in which they should be accomplished 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 gener

28、ally limited by the available processing equipment and technological capabilities of the company of plant .Parts that cannot be made internally must be purchased from outside ve</p><p>　　Process planning is

29、usually accomplished by manufacturing engineers .（Other titles include in industrial engineer.) The process planner must be familiar with the particular manufacturing processes available in the factory and be able to int

30、erpret 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

31、 usually include within the scope of pro</p><p>　　.Interpretation of design drawings. The part of product design must be analyzed (materials,dimensions,tolerances ,surface finished,etc.) at the start of the

32、 process planning procedure.</p><p>　　.Process and sequence. The process planner must select which processes are required and their sequence.A brief description of processing steps must be prepared.</p&g

33、t;<p>　　.Equipment selection . In general , process planners must develop plans that utilize existing equipment in the plant .Otherwise ,the component must be purchased ,or an investment must be made in new equip

34、ment .</p><p>　　.Tools ,dies,molds,fixtures,and gages. 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 to

35、ol design department and tool room ,or an outside vendor specializing in that type of tool is contacted.</p><p>　　Methods analysis . Workplace layout ,small tools ,hoists for lifting heavy parts ,even in so

36、me cases hand and body motions must be specified for manual operations .The industrial engineering department is usually responsible for this area.</p><p>　　.Work standards. Work measurement techniques are

37、used to set time standards for each operation .</p><p>　　.Cutting tools and cutting conditions. These must be specified for machining operations ,often with reference to standard handbook recommendations.&l

38、t;/p><p>　　Process Planning for parts</p><p>　　For individual parts,the processing sequence is documented on a form called a route sheet .(Not all companies use the name route sheet ;another name i

39、s “operation sheet .”)Just as engineering drawings are used to specify the product design ,route sheets are used to specify the process plan .They are counterparts,one for product design ,the other for manufacturing .A

40、typical route sheet ,illustrated in Fig.21.1,includes the following information: (1) all operations to be performed on the work pa</p><p>　　Decisions on process to be used to fabricate a given part are based

41、 largely on the starting material for the part .This starting material is selected by the product designer.Once the material has been specified ,the range of the possible processing operation is reduced considerably .The

42、 product designer’s decisions on starting material are based primarily on functional requirements ,although economics and manufacturability a role in the selection.</p><p>　　Fig.21.1 Typical routes sheet fo

43、r specifying the process plan </p><p>　　Table 21-1 Typical Guidelines in Preparing a Route Sheet</p><p>　　Fig.21.2 Typical sequence of processes required in part fabrication</p><p&

44、gt;　　A typical processing sequence to fabricate an individual part consists of : (1) a basic process,(2)secondary processes ,(3) operations to enhance physical properties,and (4)finishing operations.The sequence is shown

45、 in Fig.21.2. A basic process determines the starting geometry of the workpart.Metal casting ,plastic molding ,and roling of sheet metal are examples of basic processes.The starting geometry must often be refined by seco

46、ndary processes,operations that transform the starting geometry (</p><p>　　Once the geometry has been established ,the next step for some parts is to improve their mechanical and physical properties .Operati

47、ons to enhance properties do not alter the geometry of the part;instead,they alter physical properties .Heat treating operations on metal parts are the most common examples .Similar heating treatments are performed on g

48、lass to produce tempered glass.For most manufactured parts ,these property-enhancing operations are not required in the processing sequence ,as indi</p><p>　　Finally finish operations usually provide a coat

49、on the work parts (or assembly )surface. Examples inclued electroplating ,thin film deposition techniques ,and painting.The purpose of the coating is to enhance appearance ,change color ,or protect the surface from corro

50、sion,abrasion ,and so forth .Finishing operations are not required on many parts ;for example, plastic molding rarely require finishing .When finishing is required ,it is usually the final step in the processing sequence

51、 .Table 21-</p><p>　　In most cases,parts and materials arriving at the factory have complete their basic process.Thus ,the first operation in the process plan follows the basic process that has provided the

52、starting geometry of the part ..For example ,machined parts begain as bar stock or castings or forgings,which are purchased from outide vendors.The process plan begains with the machining operations in the company’s own

53、plant .Stempings begin as sheet metal coils or strips that are bought from the rolling mill.Th</p><p>　　In addition to the route sheet ,a more detailed description of eac operation is usually prepared. This

54、is filed in the particular production department office where the operation is performed.It lists specific details of the operation ,such as cutting conditionsand toolings(if the operation is machining )and other instruc

55、tions that may be useful to the amchine operator.The desciptions often include sketches of the machine setup.</p><p>　　Table 21-2 Some Typical Process Sequence</p><p>　　Processing Planning for

56、Assemblies</p><p>　　The type of assembly method used for a given product depends on factors such as : (1) the anticipated production quantities ;(2) complexity of the assembled product ,for example ,the numb

57、er of distinct components ;and (3)assembly processes used ,for example ,mechanical assembly versus welding .For a product that is to be made in relatively small quantities ,assembly is usually performed on manual assembl

58、y lines .For simple products of a dozen or so components,to be made in large quantities ,auto</p><p>　　Process planning for assembly involves development of assembly instructions,but in more detail .For low

59、production quantities,the entire assembly is completed at a single station .For high production on an assembly line ,process planning consists of allocating work elements to the individual stations of the line, a procedu

60、re called line balancing.The assembly line routes the work unit to individual stations in the proper order as determined by the line balance solution.As in process planning for</p><p><b>　　laid out.<

61、;/b></p><p>　　Make or Buy Decision </p><p>　　An important question that arises in process planning is whether a given part should be produced in the company’s own factory or purchased from an

62、 outside vendor ,and the answer to this question is known as the make or buy decision .If the company does not possess the technological equipment or expertise in the particular manufacturing processes required to make t

63、he part ,then the answer is obvious: The part must be purchased because there is no internal alternative .However ,in many cases ,the </p><p>　　In our discussion of the make or buy decision ,it should be rec

64、ognized at the outset that nearly all manufactures buy their raw materials from supplies .A machine shop purchases its starting bar stock from a metals distributor and its sand castings from a foundry .A plastic molding

65、plant buys its molding compound from a chemical company.A stamping press factory purchases sheet metal either fro a distributor or direct from a rolling mill.Very few companies are vertically integrated in their produ<

66、;/p><p>　　There are a number of factors that enter into the make or buy decision .We have complied a list of the factors and issues that affect the decision in Table 21-3 .One would think that cost is the most

67、important factor in determining whether to produce the part or purchase it .If an outside vendor is more proficient than the company’s own plant in the manufacturing processes used to make the part ,then the internal pro

68、duction cost is likely to be greater than the purchase price even after the vend</p><p>　　The quoted price for a certain part is $20.00 per unit for 100 units .The part can be produced in the company’s own p

69、lant for $28.00. The components of making the part are as follows :</p><p>　　Unit raw material cost = $8.00 per unit</p><p>　　Direct labor cost =6.00 per unit </p><p>　　Labor overhe

70、ad at 150%=9.00 per unit </p><p>　　Equipment fixed cost =5.00 per unit </p><p>　　________________________________</p><p>　　Total =28.00 per uniit </p><p>　　Table 21-3 F