Thermal Deformation And Compensation Technology Of Machine In High-speed Cutting

The errors of thermal deformation induced the accuracy of high-speed and high-accuracy machine tool is the most important factor, and the error compensation-technique is an effective way to improve the manufacturing accuracy of machine tool, it has the advantage of high-precision compensation, strong robustness, high reliability, optimal economic benefit, easy operation and so on. Effective error-compensation mainly relies on establishment of accurate compensation-model. This paper briefly summarizes the research status of domestic and foreign machine tools on thermal compensation. On this basis, taking the CX8075 vertical machining center as example, studied and analyzed the key technologies in thermal error compensation. The main techniques include:analyzed and calculated the steady-state temperature field and thermal deformation of the machine and key components, selected and optimized the temperature measuring points, established and optimized the thermal error model, analyzed and verified the result with the experiment. The results show that the research can dramatically improve the accuracy.The main contents and achievements of this dissertation are shown as follows:(1) Established the three-dimensional finite element model of CX8075 vertical machining center, and on the basis of the heat source and the basis of thermal boundary conditions, analyzed the steady-state temperature field and thermal deformation of the machine and key components, which provides a strong theoretical basis for the error compensation of thermal deformation.(2) In allusion to the distribution of steady-state temperature field, determined the thermal key points reasonably, in the condition of thermal error model accuracy, optimized the thermal key points, found the best temperature measuring points, so as to realize arrangement of temperature sensor and improve the thermal error model robustness.(3) Grouping variable quantity with the regress function of Matlab, found the typical variable. In allusion to vertical machining center, combining least square method with multivariate linear regression, we choose three ways to establish the system's thermal error compensation models respectively, and feedback to the results through experiment, after that select the best one as the final model, which can improve the machining accuracy. Finally, we can demonstrate the validity of this method through products.(4) Established the thermal error model with neural network, and compared with the model of combining least square method with multivariate linear regression. Finally choose the best modeling method.