齿形件精冲成形时的齿顶塌角分析及措施

Analysis and measure on tooth crown collapse angle in fine blanking for tooth parts

针对精冲成形齿形件时的齿顶塌角问题,首先分析了齿形零件的几何特征及精冲成形特点,并分析了这些特征与齿形零件精冲时齿顶塌角的关系;将精冲变形区分为2个核心变形区和2个变形影响区,对核心变形区Ⅰ精冲塌角的形成过程进行了分析。然后,通过有限元模拟软件Deform-3D,找出齿顶塌角处材料在成形过程中的流动规律。结果表明:齿顶处A面轮廓附近的材料沿齿顶径向运动,一部分材料流向齿顶外侧;齿廓B、C侧附近的材料沿其轮廓线所指向的齿顶方向流动。再次,全面分析了影响精冲齿顶塌角大小的各种因素,找出压边力和反顶力对塌角大小的影响规律,得出反顶力比压边力对控制塌角的效果更显著。最后,提出了在齿形零件精冲成形过程中减小或消除齿顶塌角的具体措施对策。

For the problem of the tooth crown collapse angle in fine blanking of tooth parts, firstly, the geometric characteristics of tooth parts and characteristics of fine blanking were analyzed, and the relationship between these features and the collapse angle of tooth parts during fine blanking was also analyzed. Then, the deformation zone of fine blanking was divided into two core deformation zones and two deformation influencing zones, and the forming process of collapse angle in the core deformation zone I was analyzed. Furthermore, the flow law of material at the top of tooth during the forming process was found by the finite element simulation software Deform-3D. The re- sults show that the material near the A surface at the top of tooth moves toward the top of tooth in a radial direction, and a part of material flows to the outside of the addendum. However, the material near the B and C sides flows along the contour line toward the top of tooth. Therefore, a variety of factors affecting the size of tooth crown collapse angle during fine blanking were analyzed again, and the influences of blank holder force and ejection force on the collapse angle were found out. So it is pointed out that the effect of ejection force is more significant than that of blank holder force on controlling collapse angle. Finally, the concrete measures to reduce or eliminate the tooth crown collapse angle during the fine blanking process of tooth parts were put forward.