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Process Selection - From Design to Manufacture Part 9

Tham khảo tài liệu 'process selection - from design to manufacture part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 184 Selecting candidate processes completed assemblies from workstation to workstation is required. In general the various types of station transfer system for flexible assembly are Single- multi-station assembly at one or more workstations where a specific or more commonly a variety of operations are performed. Typically greater than six components to be assembled requires a multi-station arrangement. Synchronous indexing moved with a fixed cycle time using in-line rotary dial or carousel systems. Economic considerations Only moderate flexibility despite name. Systems can be adapted for the assembly of several different products variants. Production rates moderate. Lead time weeks to months. Economical for moderate to high production volumes. Tooling costs high. Equipment costs moderate to very high. Direct labor costs low. Programming teaching of robot operations and movements is complex and lengthy. Typical applications General assembly materials handling and transfer of parts and assemblies For hazardous environments to humans e.g. radioactive toxic dusty and high temperatures Part loading and or unloading for manufacturing processes e.g. machining centers pressure die casting machines and injection molding machines Spot and MIG welding Abrasive jet machining Surface finishing grinding buffing and spray painting operations Design aspects Use DFA techniques in order to develop assemblies with optimum part-count improved component geometry for feeding handling fitting and checking and reduce overall assembly costs. Develop an assembly sequence diagram to optimize the assembly line. Assess overall assembly tolerance against component tolerances in stack up. Quality issues In general assembly problems are caused by a number of factors Components exceeding or being lower than the specified tolerances Component misalignment and adjustment error Gross defects malformed missing features wrong lengths damage in transit etc. Foreign matter causing contamination and .