汽车三叉式万向节精密成形工艺

Precision forming process on automobile trident universal joint

采用开式模锻工艺生产汽车三叉式万向节,需要切除飞边,不仅材料利用率低,同时由于金属流线被切断,影响零件的力学性能及使用寿命。为解决上述问题,提出了闭塞式单向挤压、闭塞式双向挤压两种精密成形工艺,并采用DEFORM有限元软件对两种工艺下的零件成形过程进行了数值仿真模拟,分析比较了两种工艺下的零件成形情况、金属流动规律、载荷-行程曲线,以及模具磨损情况。结果表明:在闭塞式单向挤压成形工艺下,零件存在填充不完整、销轴弯曲、端部出现斜面等缺陷,而在闭塞式双向挤压成形工艺下,零件成形良好;闭塞式双向挤压成形工艺中,金属流动更为合理、模具间承受载荷大小的差距更小,利于集体换模,且模具磨损量更小,模具使用寿命更长。经实际生产试验,获得了质量良好的三叉式万向节制件,验证了数值仿真模拟结果的准确性与可靠性。

The automobile trident universal joint produced by the open die forging process requires to remove the flash, the material utilization rate is low, and the mechanical properties and the service life of parts are affected due to the cutting off of metal streamlines. In order to solve the above problems, two kinds of precision forming processes, namely, closed one-way extrusion and closed two-way extrusion, were proposed. Then, the forming processes of parts under the two processes were simulated by finite element software DEFORM respectively, and the forming condition, the metal flow law, the load-stroke curve and the die wear condition of parts under the two processes were analyzed and compared. The results show that under the closed one-way extrusion process, the parts have defects such as incomplete filling, bent pin shaft and inclined plane at the end, while under the closed two-way extrusion process, the parts are well formed. Furthermore, under the closed two-way extrusion process, the metal flow is more reasonable, the difference in the load bearing size between the dies is smaller, which is conducive to the overall die change, the die wear is smaller, and the service life of die is longer. Through the actual production test, the good quality trident universal joint parts were obtained, which verifies the accuracy and reliability of the numerical simulation results.