Stiffness Analysis And Structural Optimization Of Key Components In Precision CNC Vertical Lathe

With the development of modern numerical control machine tools,higher and higher requirements are put forward for the processing performance of machine tools.The machining accuracy and stability of CNC machine tools are directly affected by the structural characteristics of key parts.Therefore,the optimization design of machine tool components has become a research focus in the field of CNC machine tool manufacturing.This paper focuses on Shandong Province's major scientific and technological project "Modular NC Vertical Lathe Intelligent Manufacturing Unit Development and Application Demonstration",In order to improve the processing performance of machine tools,the dynamic and static characteristics of key parts of machine tools are studied,which provides a theoretical basis for the structural optimization design of machine tools.The main research object of this paper is J1VL-600 NC vertical lathe.The finite element analysis method is used to analyze the static and dynamic characteristics of the whole machine and its key components(such as column,base,spindle system,etc.).And the weak links of machine tool parts are found according to the results of finite element analysis,the corresponding structural optimization and improvement schemes for machine tools and key components are proposed.On this basis,the lightweight design technology of machine tool structure is explored.Firstly,according to the structural characteristics of J1VL-600 NC vertical lathe,the pre-processing method of finite element analysis suitable for NC machine tools is proposed,including the mesh division of machine parts,constraints,load application and contact surface setting,etc.The finite element analysis model of the base,spindle,column and other key parts and the whole machine is established.Secondly,the static and dynamic characteristics of NC vertical lathe are analyzed by finite element analysis method.Combining with the theory of static analysis,the static simulation analysis of the whole machine tool and its key parts is completed,and the deformation and stress of each part are studied.The modal simulation analysis of the whole machine and its key parts is completed,and the vibration characteristics of the machine tool parts and its low-order natural frequencies and modes are studied.On this basis,aiming at the rib structure existing in the machine tool,the influence of the layout of different stiffened plate structures in unit volume on the dynamic and static characteristics of the machine tool parts is explored,and the structural optimization of the key parts of the machine tool is completed.Finally,on the basis of studying the internal heating law of machine tool spindle system,the steady-state thermal analysis of the spindle system is carried out,and the stress and strain of the spindle system under the coupled action of temperature and structure are deeply explored.Aiming at the structure layout of the spindle system of the machine tool,a structural improvement of the spiral groove heat dissipation mode of the spindle sleeve is proposed,which reduces the thermal deformation of the spindle system and improves the processing performance of the machine tool.