• CN:11-2187/TH
  • ISSN:0577-6686

›› 2010, Vol. 46 ›› Issue (21): 54-60.

• 论文 • 上一篇    下一篇

基于广义加工空间概念的机床动态特性分析

刘海涛;赵万华   

  1. 西安交通大学机械制造系统工程国家重点实验室
  • 发布日期:2010-11-05

Dynamic Characteristic Analysis for Machine Tools Based on Concept of Generalized Manufacturing Space

LIU Haitao;ZHAO Wanhua   

  1. State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University
  • Published:2010-11-05

摘要: 针对研究机床在广义加工空间中动态特性的变化规律,提出机床广义模态和广义刚度场的概念。采用有限元法建立三轴龙门机床和四轴立式机床的动力学模型,通过动力学模型修正的方法在整个加工空间进行模态分析和动力响应分析,分别建立广义模态函数和广义刚度场函数。通过对3轴机床广义模态函数分析,得到了机床前5阶固有频率在整个加工空间中的变化规律,可以看出,固有频率在加工过程中变化最大可达25%,广义模态为机床性能的优化提供完整的模态信息。通过对4轴联动机床广义动刚度场函数的分析得出,机床在此频率下的刀具最优姿态,在另一频率下刚度可能就不是最佳,从而为优化机床的加工工艺,提高机床加工精度提供理论支持。

关键词: 动态刚度, 动态特性分析, 广义加工空间, 优化

Abstract: Aiming at studying the variation of the machine tools’ dynamic characteristics in generalized manufacturing space, a concept of generalized modal and dynamic stiffness is put forward. Finite element method is employed to set up dynamic models for a three-axis gantry-type machine tool and a four-axis vertical machine tool. Modal and dynamic response analysis are carried out through out the whole manufacturing space with dynamic model modified method, in order to establish generalized modal function and stiffness map function respectively. By means of generalized modal analysis for three-axis gantry machine tool, the first five order natural frequencies of the machine tool through out the manufacturing space are obtained. The results show that the maximum change of natural frequencies can reach up to 25% during machining process, so complete modal information is obtained to provide data for performance optimization of machine tool. With the analysis of generalized dynamic stiffness for four-axis vertical machine tool, it can be concluded that the best working state in some frequency is not the best one for another, and then the theoretical support is present for the process optimization and accuracy promotion of machine tools.

Key words: Dynamic characteristic analysis, Dynamic stiffness, Generalized manufacturing space, Optimization

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