Study On Faucet Optimum Structure Design For Implementing DFSS

The intrinsic quality of a product is determined by the design. In order to enhance the efficiency, more and more enterprises are applying Six Sigma to designing. Combining the major role Six Sigma played in the quality management of designing in her company, an in-depth analysis of how to control and improve the quality of product designing by better using Six Sigma has been conducted in this dissertation.By an actual case of T48-FL, the application of Six Sigma theory to mechanical design has been expounded in the paper for faucets. Through the designing tolerance accumulation of assembly dimensional chains with DFSS and the analyzing the mechanical structure for the main components, the high-precision under the requirement of strength has been achieved. This will significantly improve the design quality and rate of assembly success, and then will reduce costs and improve business efficiency.The study work in the design for T48-FL according to DFSS (IDDOV) constituted by four stages of Identify/Define, Design, Optimize, and Verify is presented as follows.Firstly, the identifying and defining the CTQs by QFD and DFMEA has been made in the o-ring gland width variation, the vertical clearance between handle and stem, and the vertical clearance between handle bushing and ring clip.Secondly, all nominal dimensions and their tolerance have been defined, and the dimensional chains of the faucet have been designed and assembled through Pro/E.Thirdly, related theoretical formula of Six Sigma has applied to calculate the tolerance accumulations of assembly dimensional chains with Excel.Fourthly, the spline structure of the faucet has been analyzed in finite element method with Pro/M to validate the design of dimension chains. The design for seal of the O-ring with Parker inPHorm O-Rings software and its optimizing with Excel function formulas has been carried out. Based on above analysis, the tolerance accumulation design has been optimized for Six Sigma. Finally, the design has been verified by FAI. The result shows all Cpks are over 1.33 for all critical dimensions so that Sigma Score is not lower than six.The result of the study has important application value in analyzing dimension chain tolerance accumulation by using Design for Six Sigma. It provides a method and basis of analysis for faucet mechanical design.Therefore, during the product design stage, it can improve the success rate of assembly, ensure product quality, reduce cost and shorten delivery time to consider the organic combination of finite element analysis, o-ring analysis and Design for Six Sigma on tolerance accumulation.