曲轴RR法限制成形的模拟及模具结构优化

Simulation and Optimum of Die Structure in RR Forging Process of Crankshafts

对于非椭圆截面曲臂的大型曲轴,其模具结构设计对曲轴成形后的形状尺寸精度影响极大。本文采用三维刚粘塑性软件TFORM3对12V240曲轴RR法限制成形工艺及模具结构进行了设计分析。提出了防止成形缺陷产生的新的模具结构方案,该方案通过改进模腔横截面形状设计和增加模具水平镦粗面的斜度来加强模具对毛坯塑性变形的约束,从而为曲轴RR法镦锻工艺及模具设计提供理论依据。

The design of die structure has much influence on shape dimension and precision of the formed crank-arm with a non elliptical section. The RR process of the 12V240 crankshaft and die structure are designed and studied using the TFORM3 software of 3D rigid plastic FEM. A new design scheme of die structure to prevent generation of forming defect is put forward, and it can enhance the restrain of dies to deformation of billets in the process by means of improving geometrical design of section on die cavities and changing the angel of the horizontal upsetting surfaces of dies. Thus, this offers a scientific basis for optimum design of the process and dies.