提高高速数控机床热误差补偿精度的关键理论研究

项目名称： 提高高速数控机床热误差补偿精度的关键理论研究

项目编号： No.U1204524

项目类型： 联合基金项目

立项/批准年度： 2013

项目学科： 机械工程学科

项目作者： 王秀山

作者单位： 河南农业大学

项目金额： 31万元

中文摘要： 精密超精密加工条件下，影响高速数控机床精度的所有误差中，热误差占主导地位，使用误差补偿技术能够有效地减小或消除热误差。但是，目前的热误差补偿理论面临机床的温度场及其热变形场求解不精确、补偿用的热关键点选择过程不严谨和补偿模型不能反映热变形过程等科学难题。为此，本项目主要研究：①改进和修正求解热弹性方程中对流换热系数的计算方法，获得更为精确的对流换热系数，从而阐明主轴振动对主轴温度场及其热变形场分布的影响。②使用信息处理理论把热变形场转化为可处理的数字图像，并对图像节点进行压缩和寻优计算，从而优化出理论上最佳的热关键点，这一方法使热关键点的配置完全建立在了科学理论上。③开发动态系数建模法，使建立的模型能够时序、动态地反映主轴的热变形过程。以上三个方面的技术及理论革新，为提高高速电主轴热误差补偿的精度提供科学依据。

中文关键词： 数控机床；热变形；小波压缩；遗传算法；补偿

英文摘要： Under the precision and ultra-precision processing conditions, the thermal errors are most important from all errors influencing on the precision of high speed CNC machine tools, using error compensation technology can effectively reduce or eliminate the thermal errors. However, the current thermal error compensation theory has encountered many technical problems. The solution process of temperature field and the thermal deformation field are not precise. Selecting process of the thermal critical point for compensation is not rigorous. The compensation model cannot reflect the thermal deformation process of the machine tools. So, This project studies: ①Derive a new method for computing the coefficient of convection heat transfer of the spindle surface on revolving. The theory on computing the transient thermal response and thermal deformation is introduced and the simulation is implemented on the spindle and spindle box of the CNC turning center. ②By use of the thermal error sensitivity, according to the principle of maximizing the sum of absolute value of the differences among thermal key points’ thermal error sensitivities, provide a simple arithmetic to select the thermal key points in the case of less number of candidate points which is verified on the spindle. ③A new modeling method, that is, Dynamic Coeffi

英文关键词： NC machine tool；thermal deformation；Wavelet compression；genetic algorithm；compensation