Transactions of Materials and Heat Treatment

Title：Tooth top tearing problem of closed extruding fine blanking forming for spur gear

Authors： Lv Lin Liu Yaqi Liu Luzhou Deng Ming

Unit： Chongqing University of Technology

KeyWords： closed extruding fine blanking spur gear tooth top tearing

ClassificationCode：

year,vol(issue):pagenumber：2015,40(4):20-23

Abstract：

The stress and strain states of shear deformation zone at tooth top and root end of closed extruding fine blanking spur gear were analyzed by the finite element analysis software, and the influences of the clearance of convex and concave die, counter force and the outer ring filling rate on tear at tooth top were analyzed. The results show that hydrostatic pressure stress of tooth top decreases gradually with the punch moving downwards, and tensile stress appears near the tooth top side due to the friction force impacting on three surfaces, which leads to lack of hydrostatic pressure stress and cracks. Besides, work hardening can also lead to cracks at tooth top. The odds of crack appearing at tooth top has positive relationship with clearance of convex and concave die, while negative relationship with counterforce and the outer ring filling rate. It is found that the cracks can be controlled effectively with the increase of counterforce and the outer ring filling rate and decrease of clearance of convex and concave die.

Funds：

国家自然科学基金资助项目(51375521)；重庆市高校优秀成果转化资助项目(KJZH14107)

吕琳（1968-），女，硕士，教授

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