卡扣結合因具有省工時與易於分解等特性而常應用於消費性產品如手機或衛星導航系統的外殼結合及固定。本研究目的即探討與分析此種塑膠外殼多重卡扣結合結構之力學行為。結合商用有限元素分析軟體與田口實驗設計方法探討卡扣設計重要參數如卡扣配置、插入角度、材質、根部寬度、根部厚度、保持面深度、保持面寬度、長度對於卡扣插入力及固定能力的影響,分別尋求最佳化設計方案使卡扣裝配過程插入力可達到最小及組合後脫離力可達到最大的結構。在本研究使用灰關聯理論進行多重品質分析已成功的找出符合設計要求的最佳參數組合,且由個案之分析結果可知,影響插入力最大的設計因子為卡扣根部厚度,其次為卡扣保持面深度,卡扣插入角度,卡扣長度等。影響脫離力最大的設計因子為卡扣保持面深度,其次為卡扣配置,材質,卡扣長度等。
Snap-fit joint is commonly used for directly joining and fixing the separate plastic cabinets of products like mobile phone because of easy assembly and disassembly. The purpose of this study is to investigate the inserting and holding force of this kind of joints for two mating plastic parts. Combination of commercial finite element analysis software and the design of Taguchi method are used to search the effects of design parameters like snap fit layout, insertion angle, materials, beam width, beam thickness, depth of dwell face, width of dwell face,beam length of snap-fit on inserting force and the holding force of the whole joints. In this case study, in order to search the optimum design of snap fit on the minimum inserting force and maximum holding force of mating components. gray relational theory of multiple-quality analysis has been performed to yield an optimum solution under the design criteria.The final results show that the first three influential factor for minimum inserting force is thickness of component, depth of dwell face, and insertion angle. And the first three influential factor on maximum holding force is the depth of dwell, snap fit layout, and materials.