精密卧式加工中心主轴轴向热误差补偿方法

热误差是精密机床最主要的误差源之一。主轴是机床的关键部件,其热误差直接影响机床的加工精度。文章以某型号精密卧式加工中心主轴为对象,对其温度场和热变形进行了仿真分析。根据仿真结果发现主轴轴向热变形更严重,并结合机床结构确定温度传感器布置位置。在此基础上,对不同转速下主轴部分位置温度和轴向热误差进行现场测试。运用最小二乘法建立热误差补偿模型,直接结合机床FANUC数控系统实施主轴轴向热误差补偿。经实验验证,补偿后主轴轴向热误差减小了85%以上。

Axial Thermal Error Compensation Method for the Spindle of the Precision Horizontal Machining Center

Thermal error is one of the most significant errors of the precision machine tool.The spindle is a primate part of the machine tool,and its thermal characteristics have great influence on the accuracy of the machine tool.The temperature field and thermal deformation of the spindle of a certain type of precision horizontal machining center w ere analyzed first.It w as found that the axial thermal deformation w as larger than the radial thermal deformation.And the optimal places of the temperature sensors w ere determined considering the structure of the machine tool.Then the temperature of some certain points on spindle and axial thermal deformation of spindle operating at different rate w ere measured.On basis of the experimental data,the thermal error compensation model w as built by using least square method.The predicted thermal error based on the model w as sent to the FANUC CNC system directly for thermal error compensation.The test results show ed that the axial thermal error w as reduced more than 85 percent.