High Speed Lathe Spindle System Thermal Deformation Simulation Analysis And Experimental Research

The deformation of Spindle system of machine tool and feed system is the main cause that leads to thermal error of machine tool (the error caused by thermal deformation of all parts of machine tool). Numerous researches show that thermal error of machine tool takes approximately40%-75%part of the machining error. High speed machine tool has faster feed speed and higher thermal power. Therefore, the control and compensation of thermal errors are the key technology to modify the machining accuracy of high speed machine tool.This paper is based on the science and technology major project "Top Grade CNC Machine Tools and Basic Manufacturing Equipment". According to the requirements of this project, we use finite element analysis (FEA) and experimental test to analyze the thermal characteristic of CH7516GS series of high-speed cutting centers in this paper, and eventually put forward the control methodology of thermal error of high speed machine tool and design the compensation system of thermal deformation.The main research work:1. According to finite elements mesh about spindle system based on the grid assembly, greatly reduces the difficulty of large assembly grid division. Thermal characteristics of CH7516GS high speed CNC spindle system including the contact resistance with finite element method are analyzed. Finished the theoretical research about the spindle axis drift using the method of least square circle.2. Thermal characteristics of CH7516GS high speed CNC feed system are analyzed.3. The dynamic testing systems about temperature and thermal deformation, along with experiments and data analysis are constructed. Experimental researches thermal deformation and surface run-out of spindle. Then processing the experimental datas using digital signal processing. The selected temperature point was used to new generation of high speed machine tool by companies.4. The control methodology of thermal error in high speed machine tool is researched. Propose a constant warm-up machine program, it can greatly improve the efficiency of warming-up machine, reduce the processing errors in the cold state.5.According to the existing BP neural network model, the thermal deformation compensation based on Giant Magnetostrictive Actuator is designed, and the thermal deformation compensation system is built.This paper concludes:1.Thermal deformation of high speed machine tool and the rotational speed are of positive correlation. Temperature rise significantly when the rotational speed above3000r/min.2.The heat of the thermal deformation about the high-speed spindle system is more than the ordinary one, therefore, better thermal structure and thermal properties about the high-speed machines tool is required, not simply a upgrade to a common machine tool.3.Surface run-out of spindle reduces along with the rotational speed and time increasing.4. Warming up with constant temperature water can improve the efficiency and reduce the machining errors without warming up.