基于粒子群算法的大模数齿轮冷挤压变过盈量组合凹模优化设计

Optimization design on cold extrusion changeable interference combined mould for large module gear based on particle swarm optimization

针对大模数圆柱直齿轮冷挤压过程中均匀过盈量组合凹模易出现开裂的问题,提出一种变过盈量组合凹模的设计方法,并以直径比、中圈内壁锥角和过盈系数为设计变量,以降低模芯内壁等效应力、避免模芯出现周向拉应力和避免内外圈塑性变形为优化目标,建立变过盈量组合凹模结构参数与综合加权评分值的Kriging模型。应用Kriging模型结合粒子群算法,在可行变量空间内寻优,得到最优工艺参数组合为:n_2=1.55,n_3=2.55,γ'=1.25°,β_2=2.5‰,β_3=2.4‰。研究结果表明,采用优化后的变过盈量组合凹模可有效避免组合凹模的破裂,提高模具的使用寿命。

For the crack problem of combined die in cold extrusion process of large module cylindrical spur gear,the design method of changeable interference combined mould was proposed. Then,the Kriging model with changeable interference combined mould structure parameters and integrated weighted score was established by design variables of the diameter ratio,the angle of inner wall of shrink ring and the interference coefficient and the optimization objective of reducing the equivalent stress of the inner wall of mould core,avoiding the circumferential tensile stress and plastic deformation of the inner and outer ring. The optimal process parameters with n2= 1. 55,n3=2. 55,γ＇ = 1. 25°,β2= 2. 5‰,β3= 2. 4‰ in the variable space were found by the Kriging model combined with particle swam optimization. The research results show that the design method of the changeable interference combined mould can avoid the fracture of the combined mould and prolong the service life of mould.