Tham khảo tài liệu 'process selection - from design to manufacture episode 2 part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Appendices Appendix A - Guidelines for assembly-orientated design Product Level Guidelines - Optimise or reduce part-count and types by consolidation and integration of features parts see Figure A2 Reduce number of fasteners to a minimum - Reduce variants and modularise the design Design for an optimum assembly sequence - Provide a base for assembly to act as a fixture or work carrier - Design the assembly process in a layered fashion from above - Keep centre of gravity low Use gravity to aid assembly operations - Minimise overall product weight Design parts for multi-functional uses where possible - Eliminate unnecessary joining processes Strive to eliminate adjustments especially blind adjustments and shimming Ensure adequate access and unrestricted vision - Use common efficient fastening systems when they must be used Component Level Guidelines - Use standard components where possible Maximise part symmetry Design parts that cannot be installed incorrectly Minimise handling and re-orientation of parts - Design parts for ease of handling from bulk avoid nesting tangling -4- Design parts to be stiff and rigid not brittle or fragile - Design parts to be self-aligning and self-locating tapers chamfers radii Use good detail design for assembly - Avoid burrs and flash on component parts Fig. A1 Design for assembly guidelines and objectives. Appendices 305 Three basic questions should be asked to evaluate the feasibility of combining parts 1. When the product is being used does one part move with respect to mating parts 2. Must adjacent parts be made of different materials 3. If parts were combined would manufacture assembly of other parts or servicing be made more difficult or impossible If the answer is YES TO ANY PROBABLY NOT FEASIBLE NO TO ALL GOOD CANDIDATE TO BE COMBINED The important principles in combining parts are - Incorporate hinges Use integral springs - Use snap fits - Incorporate guides bearings covers etc - Put electrical and electronic components in .
