1、1 附录 Process Planning The product design is the plan for the product and its components 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
2、 manufacturing .Process planning 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 topics. At the outset ,we should distinguish between process planning and prod
3、uction planning ,which is covered in the following chapter. Process planning is concerned with the engineering and technological issues of how to make the products and its parts. What types of equipment and tooling are required to fabricate the parts and assemble the product ? Production planning is
4、 concerned with the logistics of making the product .After process planning is concerned with ordering the materials and obtaining the resources required to make the product in sufficient quantities to satisfy demand for it. Process Planning Process planning involves determining the most appropriate
5、 manufacturing and assembly processes and the 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 generally limited by the available proce
6、ssing equipment and technological capabilities of the company 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 2 point we will return to later. Pro
7、cess planning is 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 interpret engineering drawings .Based on the planners knowledge,sk
8、ill,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 (materia
9、ls,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 , proces
10、s 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 equipment . .Tools ,dies,molds,fixtures,and gages. The process must decide what tooling is required for each processing step.The actual design
11、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
