高速磨床整机动态特性研究

Whole Machine Dynamic Characteristic Analysis of High Speed Grinder

建立了某高速凸轮轴磨床整机的三维有限元模型,利用反求方法确定了结合部的基础参数,对整机进行了模态分析,初步确定了整机动态性能的薄弱环节,研究了结合部刚度参数对整机低阶模态的影响,提出了结构改进方案。建立径向基函数近似模型表征床身—工作台系统结合部刚度与其固有频率之间的隐式函数关系,通过对该系统进行模态实验测试,并与优化方法相结合,确定了该高速磨床床身工作台系统的结合部刚度参数。结果表明,该方法对整机建模和动力学性能的分析简单有效,增加垫板在床身上的约束可以有效地改善该高速磨床的动态特性。

A 3D finite element model of high--speed camshaft grinder was set up, and the tunda- mental parameters of joint surface were identified by inverse solution. By modal analysis for the whole grinder, the weak points of machine dynamic performance were found. Then, the investigation of the low modes for the whole machine revealed the effect of the stiffness parameters at unit joint surface, and the suggestions of structural improvement were proposed. The radial basis function（RBF） model was used to express the implicit function relation, which was about the joint stiffness of bed--base plate system and the frequency of the system. The stiffness parameters of joint surface were deter- mined, by means of mode test for the system and optimization. The results show that this method is simple and available for the whole grinder modeling and the dynamic performance analysis, and the method of increasing the number of bolt on the base plate can improve a dynamic characteristics of the high-- speed grinder.