Thermal Characteristics Analysis And Optimal Design Of Heavy-duty Cnc Boring And Milling Machine Tool

Heavy-duty CNC machine is urgent to energy development, aerospace, large ships, automotive and other industries of our country, which is a measure of a country’s technological level and comprehensive national strategic materials. With independent research breakthrough in some key models of heavy machine, China become a big consumer of heavy manufacturing and CNC machine tools, but not the power of high-end technology for heavy-duty CNC machine tools.Under the influence of internal and environmental factors, all key components of heavy-duty CNC boring and milling machine tools produce different degrees of thermal deformation in the course of their work, causing changes in the position of the machine tool, which influences the machining accuracy. The rise of heavy-duty milling and boring machine temperature is mainly concentrated near the spindle feed axis, while the temperature other work cell is not obvious. In this paper, the finite element method is used to study the temperature distribution of the machine and key components as well as the impact of the heat balance to the machine precision, and optimize the design of the spindle bearing assembly process and ram structural parameters, based on ANSYS optimization platform. The main work can be summarized as follows:1 With a physical model of heavy machine assembly is created by PRO/E under reasonable simplification method, explore the finite element mesh of machine tool, thermal contact resistance analysis tool assembly. Finite element model of the machine is obtained, which is the foundation of machine thermal characteristics analysis.2 Through the analysis of the heat and boundary conditions of heavy machine, the size of each heat and convection boundary coefficients is calculated according to theoretical models and empirical formulas, to establish temperature and deformation finite element model of the machine. The analysis of temperature and deformation fields of machine tool and key components is based on ANSYS. Choose a ball screw system as a key component of the test object, and comparative analysis of the ball-screw system thermal characteristics analysis of theoretical analysis with experimental results to verify the accuracy of the finite element method.3 Spindle bearing heating problems constraint to enhance the spindle speed and accuracy. Based on the assembly process of starting the spindle bearings, this article optimize spindle bearings preload with the design of the thermal and dynamic characteristics sought spindle bearings optimal configuration4 Heavy milling and boring machine temperature rise is mainly concentrated in the vicinity of the spindle. Based on ANSYS optimization platform, by optimizing the design of the structural parameters of the ram, temperature uniformity and gradient of the ram system and the front of the ram and spindle thermal deformation is improved, improving the machining accuracy.