基于广义加工空间概念机床动态特性分析.pdf

学兔兔 第46卷第21期 机 械 工 程 学 报 Vl01．46 No．2l 2010年 1 1月 JOURNAL OF MECHANICAL ENGINEERING NOV． 2 0 l 0 DoI：l0．3901，JME．2010．21．054 基于广义~jl-r空间概念的机床动态特性分析水 刘海涛 赵万华 (西安交通大学机械制造系统工程国家重点实验室 西安 710049) 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：广义加工空间 动态特性分析 动态刚度 优化 中图分类号：TG502 Dynamic Characteristic Analysis for Machine Tools Based on Concept of Generalized Manufacturing Space LIU Haitao ZHA0 Wanhua (State Key Laboratory for Manufacturing Systems Engineering，Xi’an Jiaotong University,Xi’an 7 1 0049) 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 too1．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 perform ance