以铣车复合加工中心双驱进给系统为研究对象,利用有限元法(FEM)和虚拟样机技术(VPT)建立双驱进给系统的刚柔耦合模型,对其进行运动仿真和参数优化.在模型中考虑非线性因素对模型的影响,增加了所建立模型的真实性.通过仿真得到横梁在高速进给时的加速度曲线和横梁上任意点的频率响应曲线,分析横梁出现不同程度振动的原因.以横梁上任意点的频率响应曲线最大幅值为目标函数,对两丝杠之间的跨距进行参数化建模和优化,最终得到两丝杠之间的合理取值.
Taking the double-driven feeding system of milling compound machining center as investigation object and employing finite dement method (FEM) and virtual prototype technique (VPT), a rigid-flexible coupling model of the feeding system is established and its motion simulation and parameter optimization are conducted. The influence of nonlinear factors on the model is taken into consideration in the model, so that its reality will be enhanced. By means of simulation of high-speed feeding, the acceleration curve of the crossbeam and frequency response curve of the crossbeam at arbitrary point are obtained and the reason of the crossbeam vibration to some extent is analyzed. Further, the frequency response of arbi- trary point of the crossbeam is taken as objective function to perform parameter modeling and optimization for the span of the two leading screws. And finally, a rational assignment of the latter is obtained.