金刚石线切割机床的动态特性分析与实验研究

发布时间：2019-01-26 07:39

【摘要】：线锯和进给系统是金刚石线锯切割机最重要的两个部件。线锯作为线锯切割机的刀具,其动态特性直接影响着晶片的表面粗糙度和损伤层的大小;金刚石线锯切割机进给系统的动态特性直接影响机床的加工质量和效率。因此,本文通过理论建模、有限元分析及动态特性实验相结合的方法分析了线锯和进给系统的动力学特性,研究内容主要包括:建立了线锯的有限元模型,分析了不同张紧力下线锯的固有频率,自由模态实验显示前3阶固有频率误差在5%以内,从而验证了有限元模型的正确性;在自由模态模型的基础上完成了线锯工作模态的分析与实验验证,结果显示,切削参数不变时,线锯张力越大其第1阶工作模态越大。基于二自由度理论建立了金刚石线锯切割机进给系统的动力学方程,通过经验公式分别确定了轴向上丝杠、轴承与丝杠结合面、丝杠与螺母结合面的等效刚度以及侧向上导轨与滑块结合面的等效刚度,进而确定出进给系统前4阶固有频率解析值,为进给系统参数化建模与变动态特性研究奠定了分析基础;建立了进给系统考虑结合面和不考虑结合面时的有限元分析模型,完成了相应的模态分析与谐响应分析,进给系统模态实验显示考虑结合面的进给系统有限元模型更精确,因此,研究线锯切割机涉及的结合面特性是必要的。最后,为了完善金刚石线锯切割机进给系统的有限元模型进而实现整机系统的动力学特性分析,设计了结合面特性研究的实验平台,并对其进行了强度校核,验证了实验平台设计的合理性。
[Abstract]:Wire saw and feed system are the two most important parts of diamond wire saw cutting machine. As the cutting tool of wire sawing machine, the dynamic characteristics of wire saw directly affect the surface roughness and damage layer of the wafer, and the dynamic characteristics of the feed system of diamond wire saw cutting machine directly affect the machining quality and efficiency of the machine tool. Therefore, the dynamic characteristics of wire saw and feed system are analyzed by the methods of theoretical modeling, finite element analysis and dynamic characteristic experiment. The main research contents are as follows: the finite element model of wire saw is established. The natural frequencies of wire saws under different tension forces are analyzed. The free mode experiments show that the error of the first three natural frequencies is less than 5%, which verifies the correctness of the finite element model. Based on the free mode model, the working modes of wire saws are analyzed and verified by experiments. The results show that the higher the tension of wire saws is, the greater the first working mode of wire saws is when the cutting parameters are not changed. Based on the theory of two degrees of freedom, the dynamic equations of the feed system of diamond wire sawing machine are established. The equivalent stiffness of the joint surface of the screw and nut and the equivalent stiffness of the lateral upper guideway and the slider are determined, and the analytical values of the first four natural frequencies of the feed system are determined. It lays an analytical foundation for parametric modeling and variable dynamic characteristics of feed system. The finite element analysis model of the feed system with and without the joint surface is established, and the corresponding modal analysis and harmonic response analysis are completed. The modal experiment of the feed system shows that the finite element model of the feed system considering the combined surface is more accurate. Therefore, it is necessary to study the characteristics of the joint surface involved in the wire saw cutting machine. Finally, in order to perfect the finite element model of the feed system of diamond wire sawing machine and realize the dynamic characteristic analysis of the whole machine system, an experimental platform for the study of the characteristics of the interface is designed, and its strength is checked. The rationality of the design of the experimental platform is verified.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG48

【参考文献】