Forging technology development of automobile fasteners with tooth geometries on end faces

• Main Authors: Chiuan-Shuen Tasi, 蔡全順
• Other Authors: Jinn-Jong Sheu
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/91482510332882485086

碩士 === 國立高雄應用科技大學 === 模具工程系 === 100 === This research focuses on the forming technology development of bulged tube with tooth geometries on end faces. The ratio of tube length to outer diameter is large and difficult to forge. The folding defects occurred frequently for this type product forming. Many possible forming processes were considered in this research, such as single and double action press, local heating method, solid and hollow types of billet, precision forming of tooth geometry. FEM method was adopted to predict the forming process and the die stress distribution. Real dies were made after the evaluation to verify the proposed method and designs. The results revealed the tooth geometry features should be made after the forming of other features of product in order to increase the flexibility of die design and die life. In the case of using rod billet, designs of the web and the punch of forward and backward extrusion were most critical. In the case of using tube billet, ratio of tube length to tube thickness should be chosen carefully to avoid buckling. Punch design is important too. Local heating technology could increase formability of tooth features but the forming load is high and tool life might be poor. The proposed better process is combined extrusion of forward and backward, bulging, and tooth finishing with special flash design. The tooth features on the faces were filled and the forming load is low. The experiment results showed the similar tendency of forming load and product geometry, and verified the feasibility of the proposed design.