Thermal Analysis Of Five-axis Cnc Machine Tools

With the development of the machine tool industry,the market demands for machine tool performance are increasing.If China is not in a disadvantage in the future competition,it is necessary to master the design and manufacturing technology of high-precision machine tools.In the research of reducing the workpiece error,it is found that thermal deformation is the main cause of the workpiece error in high-precision machine tools.Therefore,reducing the thermal deformation of the machine tool is an important method to improve the machining accuracy of the machine tool.In order to reduce the thermal deformation of the machine tool and improve the accuracy of the machine tool,this paper studies the self-developed five-axis CNC machine tool-spiral bevel gear machine tool,analyzes the temperature field and thermal deformation of the machine tool,and analyzes the temperature field and thermal deformation of the machine tool.According to the analysis results,the feed system with the greatest influence on the field and the thermal deformation field is improved,and the thermal error prediction model of the machine tool is established to predict and compensate the thermal error.The main research contents and achievements are as follows:(1)The main heat source and the heat dissipation modes of the five-axis spiral bevel gear CNC machine are analyzed,and the heat generation of the heat source and the heat dissipation of the machine tool are calculated according to the specific working condition of the machine tool,and the thermal load and the boundary condition of the finite element thermal analysis are set up.(2)The feed system of VMC vertical machining center,which is similar to the structure of the feed system of the machine tool and the power of the motor,is experimentally analyzed by the thermal imager.The calculation model of the convection heat transfer coefficient between the wire lever and the air is established,and the traditional mathematical model is modified.(3)Under different working conditions,the temperature field of the machine tool is analyzed,and the cloud maps of the steady-state and transient temperature distribution are obtained.Then,the thermal deformation distribution cloud diagram is obtained by the thermal-structural coupling analysis of the temperature field and the mechanical condition of the machine tool.It can be seen from the temperature and thermal deformation distribution cloud that the thermal deformation of the feed system is the main reason that affects the thermal deformation of the whole machine.(4)The feeding system with large influence on the thermal deformation of the whole machine is improved,and the lead screw body and the guide rail are added with cooling liquid,and the dimension parameters of the guide rail are optimized.The finite element analysis proves that the improved thermal deformation of the machine tool is significantly reduced.(5)Establish a thermal error prediction model of the ANN neural network five-axis CNC machine tool to predict and compensate the thermal error.In this paper,the finite element analysis of the temperature field and thermal deformation field of the five-axis CNC machine tool-spiral bevel gear processing machine has certain practical significance for reducing the thermal error of the machine tool and improving the precision of the machine tool.