矩形花键冷挤压成形工艺参数多目标优化

针对矩形花键冷挤压成形中出现齿形充填不饱满和成形力过大的缺陷问题,以x1(坯料直径)、x2(坯料初始倒角)、x3(入模半角)为优化变量,采用响应面法结合有限元数值模拟对花键冷挤压成形工艺参数进行多目标优化。根据实验设计结果分别建立了两个目标函数的二阶响应面模型,方差分析结果表明,模型预测精度高并能够较好地描述两个目标函数关于设计变量的响应。在优化范围内得到矩形花键轴成形最优工艺参数为:x1=Ф48.5 mm,x2=20°,x3=15°。将优化后的工艺参数进行实际验证,结果表明:前端塌角量降至0.27 mm,最大成形力降至1300 k N。工艺试验证明了采用多目标优化得到的工艺参数可以获得合格的产品。

Multi-objective optimization of cold extrusion process parameters for rectangle spline

For the problem of insufficient corner filling and excessive forming loads in the process of cold extrusion for rectangle spline, x1 ( diameter of billet) , x2 ( billetinitial chamfer) and x3 ( die semi-angle) were selected as optimization variables, and the multi-objective optimization of cold extrusion process parameters was studied by the response surface method ( RSM) combining with finite element meth-od ( FEM) . Then, the second-order response surface models of two objective functions were established based on the experimental design result. The variance analysis results show that the above models are of high prediction accuracy, two objective functions related to response of design variable are described clearly. Thus, the optimal process parameters of forming rectangle spline shaft are obtained as x1 =Ф48. 5 mm, x2 =35° and x3 =30°. The optimized process parameters were verified practically. The result shows that the tooth tip collapse angle reduces to 0. 27mm and the maximum forming force reduces to 1300 kN. Experimental result shows that the qualified products can be ob-tained by multi-objective optimal process parameters.