载重汽车行星齿轮冷挤压成形工艺

Cold extrusion forming process for truck planetary gear

载重汽车行星齿轮是汽车传动的重要零件,目前主要通过热锻制空心坯-冷挤压成形外齿的方式制造,该方式存在工艺路线长、成本高、耗能高的问题,严重制约了行星齿轮的发展与应用。针对该问题提出实心坯料一次冷挤压成形工艺方案,减少热锻相关工序,降低生产成本;建立行星齿轮一次冷挤压成形工艺方案有限元模型,通过DEFORM-3D有限元软件进行数值模拟分析,研究了凹模入模口半角、凹模定径带长度、下凸模锥顶角对成形质量、成形载荷的影响规律。研究结果表明:在凹模入模口半角为60°、凹模定径带长度为12 mm、下凸模锥顶角为12°时的成形质量较好。根据冷挤压一次成形工艺方案进行工艺试验,试验结果良好,满足预期要求,证实了该方案的可行性。

Truck planetary gear is an important part of automobile transmission.At present,it is mainly manufactured by the method of hot forging hollow blank and cold extrusion forming external gear,and this method has the problems of long process route,high cost and high energy consumption,which seriously restricts the development and application of planetary gear.Therefore,to solve this problem,a one-time cold extrusion forming process for solid billet was proposed to reduce the processes related with hot forging and production costs,and the finite element model of the one-time cold extrusion forming process scheme of planetary gear was established.Then,the numerical simulation analysis was carried out by finite element software DEFORM-3D,and the influence laws of half angle of die entrance,length of sizing belt for die and cone angle of lower punch on the forming quality and forming load were studied.The results show that the forming quality is better when the half angle of die entrance is 60°,the length of sizing band for die is 12 mm and the cone angle of lower punch is 12°.According to the one-time cold extrusion forming process scheme,the process test is carried out,and the test results are good and meet the expected requirements,which confirms the feasibility of the scheme.