锥鼓形冷镦成形球头的工艺参数优化

Optimization of process parameters on cone-drum ball head in cold upsetting

针对球头销类零件球头冷锻成形过程中的镦粗失稳极限问题,基于金属塑性变形理论,分析了球头冷镦过程中的受力状态,根据受力分析提出采用锥鼓形冷镦成形工艺。通过Deform-3D进行有限元数值模拟,引入4因素3水平正交试验,考察锥形角度、凹模入口处圆角、摩擦因子、冲压速度对球头成形质量的影响,以模具承受成形载荷最小为目标获得最优的工艺参数组合,即锥形角度为15°、凹模入口处圆角为R4 mm、摩擦因子为0.10、冲压速度为2 mm·s^(-1)时模具成形载荷最小。研究结果表明:在多因素交互影响下,摩擦因子对成形载荷的影响最大,其次为冲压速度和锥形角度,凹模入口处圆角的影响最小。

For the limitations of upsetting destabilizing in cold forging process of ball pin type parts, based on plastic deformation theory of metal, the load state of ball head was analyzed in cold upsetting, and the forming technology of cold upsetting for cone-drum ball head was proposed based on the results of the mechanical analysis. Then, through the finite element numerical simulation analysis of Deform-3D, the influences of the cone angle, fillet radius of die entrance, friction factor and punching speed on the forming quality of ball head were studied by the four-factor and three-level orthogonal test, and the optimum combination of technique parameters was obtained with cone angle of 15°, fillet radius of die entrance of R4 mm, friction factor of 0. 1 and punching speed of 2 mm·s^-1 to make the forming load of die minimum. The result shows that under the influence of multiple factors, the friction coefficient has the greatest influence on the form- ing load, following by the punching speed and the cone angle, and the fillet radius of die entrance is the least.