铣车复合加工中心双驱进给系统静动态特性研究

发布时间：2019-06-09 16:36

【摘要】：现代机床正朝着高速度、高精度、大负载的方向发展,作为数控机床的重要组成部分,进给系统静动态特性的好坏直接影响机床的加工质量和加工效率。本文以铣车复合加工中心双驱进给系统为研究对象,综合运用了理论建模、有限元分析、虚拟样机等技术手段对双驱进给系统进行静力学及动力学研究与仿真,取得了以下研究成果:(1)建立了双螺母预紧滚珠丝杠副的轴向接触刚度模型。考虑了结合部的影响,利用Workbench软件建立了双驱进给系统的有限元模型,并对其进行静力学仿真,得到了双驱进给系统在典型铣削工况下的静力变形云图。对单驱进给系统进行静态特性分析,并和双驱进给系统静态特性分析结果进行对比,证明了双驱进给系统的静态特性优于单驱进给系统。(2)根据机械振动理论,推导出了丝杠整体的的振型函数和振动频率方程,考虑滚珠丝杠副、直线导轨副及支承轴承结合面的影响,对双驱进给系统进行了动力学建模,并根据拉格朗日方程推导出了双驱进给系统的振动微分方程。获得了双驱进给系统的质量矩阵、刚度矩阵、阻尼矩阵。(3)建立了10组融入结合面特性的双驱进给系统有限元模型,分别对10组有限元模型进行模态分析,研究了丝杠跨距和导轨跨距对双驱进给系统动态特性的影响规律,在模态分析的基础上对原双驱模型进行了谐响应分析,分析了阻尼对双驱进给系统动态特性的影响,并提出了相应的改善措施。最后对双驱进给系统中的滚珠丝杠副进行了模态分析,研究了支承方式和螺母位置对滚珠丝杠副动态特性的影响。(4)利用虚拟样机软件ADAMS对双驱进给系统进行仿真分析,研究了横梁在快速进给时的位移、速度、加速度特性。
[Abstract]:Modern machine tools are developing towards the direction of high speed, high precision and large load. As an important part of NC machine tools, the static and dynamic characteristics of feed system directly affect the machining quality and machining efficiency of machine tools. In this paper, the dual drive feed system of milling and turning compound machining center is taken as the research object, and the statics and dynamics of the double drive feed system are studied and simulated by means of theoretical modeling, finite element analysis, virtual prototype and so on. The following research results are obtained: (1) the axial contact stiffness model of double nut pretightening ball screw pair is established. Considering the influence of the joint, the finite element model of the dual-drive feed system is established by using Workbench software, and the static simulation is carried out, and the static deformation cloud diagram of the double-drive feed system under typical milling conditions is obtained. The static characteristics of the single drive feed system are analyzed and compared with the results of the static characteristics analysis of the double drive feed system. It is proved that the static characteristics of the double drive feed system are better than those of the single drive feed system. (2) according to the mechanical vibration theory, The vibration mode function and vibration frequency equation of the whole screw are derived. considering the influence of ball screw pair, linear guideway pair and supporting bearing joint surface, the dynamic modeling of the double drive feed system is carried out. According to Lagrangian equation, the vibration differential equation of double-drive feed system is derived. The mass matrix, stiffness matrix and damping matrix of the double drive feed system are obtained. (3) Ten groups of finite element models of the dual drive feed system with the characteristics of the joint surface are established, and the modal analysis of the 10 groups of finite element models is carried out respectively. The influence of screw span and guideway span on the dynamic characteristics of dual-drive feed system is studied. On the basis of modal analysis, the harmonic response of the original dual-drive model is analyzed, and the influence of damping on the dynamic characteristics of dual-drive feed system is analyzed. The corresponding improvement measures are put forward. Finally, the modal analysis of the ball screw pair in the dual-drive feed system is carried out, and the influence of the supporting mode and nut position on the dynamic characteristics of the ball screw pair is studied. (4) the virtual prototype software ADAMS is used to simulate and analyze the double-drive feed system. The displacement, velocity and acceleration characteristics of the beam during fast feed are studied.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG547

【参考文献】