锻压技术

闭挤式精冲成形直齿轮的齿顶撕裂问题

英文标题：Tooth top tearing problem of closed extruding fine blanking forming for spur gear

作者：吕琳刘亚琦刘潞周邓明

单位：重庆理工大学

关键词：闭挤式精冲直齿轮齿顶撕裂

分类号：

出版年,卷(期):页码：2015,40(4):20-23

摘要：

运用有限元分析软件分析了闭挤式精冲直齿轮齿顶端和齿根端剪切变形区材料的应力应变状态，以及凸凹模间隙、反顶力和外环填充率对齿顶撕裂的影响。结果表明：随着凸模下行，齿顶处静水压应力逐渐下降，齿顶附近侧面由于三面受摩擦力出现拉应力，导致静水压应力不足进而出现裂纹，另外加工硬化也会导致齿顶裂纹的出现；齿顶裂纹出现的几率与凸凹模间隙大小成正向关系,与反顶力和外环填充率大小成反向关系。研究发现，随着反顶力和外环填充率的增加以及凸凹模间隙的减小，可以有效控制裂纹的出现。

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.

基金项目：

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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