DESIGN FOR ASSEMBLY NPTEL（设计组装NPTEL）.pdfVIP

DESIGN FOR ASSEMBLY Assembly is an important stage in product development and accounts for one third of the company labor. Reducing the number of parts and making the assembly easier and faster can simplify a product. In addition to the cost of assembly operation, designing for assembly has many other benefits and few are listed below.  When a product is simplified, it becomes easier to assemble in the factory and to disassemble when maintenance, repair, or disassembly for recycling is required.  Simpler assemblies often can be brought to market sooner because of fewer parts to design, procure, inspect, and stock with less probability that a delay will occur.  Reducing the number of parts requires fewer engineering and production control documents, lower inventory levels, reduced need for inspection and quality control documents, fewer setups, less materials handling, and probably, reduced purchasing workload. DESIGN CONSIDERATIONS In order to find various alternatives for smooth assembly operation, a product designer should be able to visualize how the parts can be put together and what are the difficulties in putting parts together. The designer is expected to understand the various assembly methods and different tools, fixtures, and gauges that will be used during assembly. The assembly having the fewest numbers of parts and the least costly fasteners is considered to be the best one. Assembly design of each component should be such that a minimum number of manufacturing and assembly operations are required. The usual procedure is to use the assembly or sub assembly by putting them to the main assembly with lesser cost than putting complex individual parts one by one. Mo