超聲波清洗機說的明書畢業論文(編輯修改稿)

　

【文章內容簡介】 了在設計和制造之間的一堵墻，當設計部門完成設計，他投擲工程圖和說明書越過這面墻，并且那時工藝規程制訂也開始了。圖（1） 比較 : (a) 傳統產品發展周期和 (b) 并行產品的發展周期通過比較，實行并行工程的公司，工程制造部門在早期就參與到產品發展周期。為如何使產品和他的組成能夠被設計的更適于制造提供建議。他同樣為產品提供制造計劃繼續進行的早期準備，這種并行工程的路徑在圖(1)b中被描繪出。除了工程制造以外其他功能同樣被包括在產品發展周期中，如質量工程、制造部門、后勤服務、市場供應評定組成和一些情況下將使用這些產品的消費者。在產品發展階段的所有這些功能不僅能改善新產品的功能和性能，同時也能改善他的可造性、自檢性、易測性、服務能力和可維護性。通過早期功能改善，因為在最終產品設計之后的回顧太晚以至于不能對設計進行便利的修改的不利因素的消除，使產品發展周期的持續期大大減少。并行設計包含以下因素：(1)一些制造和裝配設計(2)質量設計(3)成本設計和(4)生命周期設計。另外，像快速成型、虛擬制造、和組織轉變等輔助技術需要被用來促進公司的并行工程。制造和裝配設計據估計一件產品的70%的生命周期成本是由在產品設計時所做的基本決定所決定的，這些設計決定包括每個零件的材料、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。一旦這些決定被指定，減少產品制造成本的能力就會被限制。例如，如果產品設計者決定用鋁砂型鑄造法制造一個分開零件，但是這個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到既定要求。在這個例子中，用一個在單獨步驟所需要的塑料模制品也許是一個較好的決定。因此，當產品設計展開時給制造工程師一個忠告設計者的機會對產品的順利可造性是非常重要的。這種被用于嘗試描述順利改變一件新產品的可造性的條件是制造設計(DFM)和裝配設計(DFA)。當然，DFM和DFA是緊密相連的，因此讓我們用制造和裝配設計(DFM/A)的形式來表達。制造和裝配設計包括在一件新產品中的可造性和可裝配性的綜合考慮，這包括： (1)組織變化和(2)設計原理和指導方針。.在DFM/A中的組織變化. DFM/A的有效執行包括公司組織機構的正式或非正式的變化，因此設計職工和制造職工之間有很好的交流和交互作用。這可以通過以下方法來完成：(1)通過成立由產品設計者制造工程師和其他員工(例如：質量工程師、材料專家)組成的攻關小組來進行產品開發；(2)通過要求設計工程師用一些事業時間在制造上，以能夠掌握第一手可造性和可裝配性是如何通過產品設計聯系在一起的；(3)通過指派制造工程師到產品設計部門在一個臨時的或專任的基礎上做一個還原性顧問。.設計說明和指導方針. DFM/A為了理解如何設計一個既定產品來使可造性和可裝配性最大化也依賴于設計說明和指導方針的使用，這些通用設計指導方針中的一些幾乎適用于任何產品設計。在其他方面，一些設計原理只適用于特定工序，例如：軸或錐度在階梯中的使用和利用模制品來切除模內零件，在制造過程中我們只把這些具體過程指導方針放在書本上。指導方針有時互相矛盾，一條指導方針是“簡化零件模型，避免不必要的特征”。但是在同一表格里的另一指導方針為了裝配安全而規定在設計產品時“特殊幾何特征必須不時加上他的組成”。而且他也許值得來結合個別裝配件的特征來減少產品中零件的數量。在這些示例中零件制造設計與裝配設計相沖突，在這個矛盾沖突的兩邊，一個適當解決方法必須被發現。Process Planning and Concurrent EngineeringT. Ramayah and Noraini IsmailABSTRACTThe 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. .Interpretation of design drawings. The part of product design must be analyzed (materials, dimensions, tolerances, surface finished, etc.) at the start of the process planning procedure. .Process and sequence. The process planner must select which processes are required and their sequence. A brief description of processing steps must be prepared. .Equipment selection. 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. .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 tool design department and tool room, or an outside vendor specializing in that type of tool is contacted..Methods analysis. Workplace layout, small tools, hoists for lifting heavy parts, even in some cases hand and body motions must be specified for manual operations. The industrial engineering department is usually responsible for this area..Work standards. Work measurement techniques are used to set time standards for each operation.Cutting tools and cutting conditions. These must be specified for machining operations, often with reference to standard handbook remendations.Process planning for partsFor individual parts, the processing sequence is documented on a form called a route 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 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. A basic process determines the starting geometry of the work parts. Metal casting, plastic molding, and rolling of sheet metal are examples of basic processes. The starting geometry must often be refined by secondary processes, operations that transform the starting geometry (or close to final geometry). The secondary geometry processes that might be used are closely correlated to the basic process that provides the starting geometry. When sand casting is the basic processes, machining operations are generally the second processes. When a rolling mill produces sheet metal, stamping operations such as punching and bending are the secondary processes. When plastic injection molding is the basic process, secondary operations are often unnecessary, because most of the geometric features that would otherwise require machining can be created by the molding operation. Plastic molding and other operation that requ