基于数值模拟的汽车转向节精密成形工艺

Precision forming process for automobile steering knuckle based on numerical simulation

汽车转向节结构复杂、工艺设计难度大,因此,在实际锻造过程中易出现材料折叠、局部成形不完整等问题。针对此问题,分析了转向节的成形难点,确定了转向节的成形工艺,并采用有限元分析软件Deform对成形过程中最关键的预锻工序进行了热力耦合数值模拟,从成形过程、成形力大小、锻件温度分布情况,多角度分析了开式预锻与闭式预锻的优劣情况。结果表明:开式预锻的成形力较小,但预锻件存在填充不满的缺陷;闭式预锻的成形力较大,但能获得符合要求的预锻件,且锻件温度分布均匀,质量好。最后,以闭式预锻为基础,进行了终锻模拟试验,证明了成形工艺的可靠性,并通过生产试验进行了验证,实际结果与仿真结果相吻合,获得的转向节成品件的外观良好,质量符合设计要求。

The structure of automobile steering knuckle is complex, and the process design is difficult. Therefore, in the actual forging process, the problems of material folding and incomplete local forming are prone to occur. For the above problems, the forming difficulties of steering knuckle were analyzed, and the forming process was determined. Then, the thermo-mechanical coupling numerical simulation of the most critical pre-forging process was carried out by finite element analysis software Deform, and the advantages and disadvantages of open pre-forging and closed pre-forging were analyzed from the forming process, the value of forming force and the temperature distribution of forgings. The results show that the open pre-forging has samller forming force and the defect of insufficient filling, and the closed pre-forging has larger forming force, but it could obtain the pre-forgings that meet the requirements and has uniform temperature distribution as well as good quality. Finally, based on the closed pre-forging, the simulation test of final forging was carried out to prove the reliability of the process and was verified by the production test. The actual results are consistent with the simulation results, the finished steering knuckle has good appearance, and the quality meets the design requirements.