薄壁六角法兰螺母精冲工艺分析及参数优化

Process analysis and parameter optimization for fine blanking of thin-wall hexagon flange nut

针对薄壁六角法兰面螺母的结构特征,提出了两种精冲工艺方案,根据精冲工艺的特点,建立了精冲力学模型,并基于DEFORM-3D建立了有限元模型,对两种方案的精冲过程进行了数值模拟仿真,对比分析了两种精冲工艺方案的工件损伤值及成形载荷结果,从而获得了较优的工艺方案。其次,结合正交试验,选取模具表面硬度、摩擦系数、冲压速度及凸凹模间隙作为试验因素,建立了4因素3水平的正交试验表,研究了各试验因素对模具磨损量的影响程度,并以精冲过程中模具磨损量最小为优化目标,寻找最优方案的最优工艺参数组合。结果表明:当模具表面硬度为55 HRC、摩擦系数为0.1、冲压速度为10 mm·s^-1、凸凹模间隙为0.04 mm时,模具磨损量最小。并通过工艺试验,验证了最优工艺参数组合方案的可信性,能够有效地指导工艺及模具设计。

For the structural characteristics of thin-walled hexagon flange nut,two kinds of fine blanking process schemes were proposed,and according to the characteristics of fine blanking process,the mechanical model of fine blanking was established.Then,the finite element model was established based on DEFORM-3 D,and the fine blanking processes of two schemes were numerical simulated respectively.Furthermore,the results of workpiece damage value and forming load for two kinds of fine blanking process schemes were analyzed and compared,and a better process scheme was obtained.Then,combined with orthogonal experiment,surface hardness of mold,friction coefficient,stamping speed and clearance between punch and die were selected as the experimental factors,and the orthogonal experiment with four factors and there levels was established.Finally,the influences of each experimental factor on the wear amount of mold were studied,and taking the minimum wear amount of mold in the fine blanking process as the optimization objective,the optimal process parameter combination of optimal scheme was found.The results show that when the surface hardness of mold is 55 HRC,the friction coefficient is 0.1,the stamping speed is 10 mm·s^-1,and the clearance between punch and die is 0.04 mm,the wear amount of mold is the least.Through the process experiment,the credibility of optimal scheme for process parameter combination is verified to effectively guide the design of process and mold.