Improvement of Forming for a T-Head Bolt by Taguchi Method

• Main Authors: Chih-Chiuan Chan, 陳志權
• Other Authors: CHAO-HO HSU
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/36579677440020227481

碩士 === 國立高雄應用科技大學 === 模具工程系碩士班 === 101 === The forming of head on T-Head bolt is produced by three-stage cold forming processes. Because the height of compression rate of head is high as 85.5% during forging process, this situation is easy to occur surface crack and that will have great influence on the product quality after forming. In this study, try to find out optimal forming parameters to reduce the surface crack on the bolt in the forming process. Pro / Engineer is used to construct geometry of billet, bolt and die. DEFORM-3D is adopted to simulate the three-stage cold forging processes and to analyze die stress to find out effetive parameters of each-stage forging process. Taguchi method L8 (27) orthogonal array is used to integrate all forming parameters to simulate, and find out those high influential factors of forming parameters by analyses of S/N and confidence level. The Taguchi method L9 (34) orthogonal array integrates those high influential factors of forming parameters to analyze again. The combinational parameter of optimization is obtained by analysis of variance (ANOVA) according damage of workpiece and the maximum effective stress of die. Finally, comparing the results of analysis in new design with that in original design, it displays that new forming parameters reduces the forging force about 15%, the value of damage about 24%, and decreases the maximum effective stress of die to improve the service life of die.