数控车床热误差建模与补偿研究

数控机床热变形引起的误差通常占到总体误差的40%~70%。以某公司生产的某型卧式数控车床为研究对象,检测主轴热误差和X进给轴热误差,基于最小二乘法对该机床主轴X、Y、Z向和X进给轴分别建立热误差模型。考虑到实测环境温度相对参考温度20℃时滚珠丝杠伸长的因素,对主轴热误差实测值进行了修正。根据主轴X向修正后的热误差模型和X进给轴热误差模型建立了X轴综合热误差模型,并采用西门子840D系统进行了热误差补偿试验,热误差降低了54.5%,CP值由1.34提升至1.88,证明此该建模与补偿方法有效、可行。

Research on Thermal Error Modeling and Compensation for CNC Lathe

The error caused by thermal deformation of NC machine tools usually accounts for 40%~70%of the total errors.A horizontal CNC lathe manufactured by some company was taken as the research object,the thermal error of the spindle and the thermal error of the X feed axis were detected,and the thermal error models of the spindle X,Y,Z and X feed axes of the lathe were established respectively based on the least square method.Considering the factor of the elongation of the ball screw when the measured ambient temperature was 20℃relative to the reference temperature,the measured thermal error of the spindle was corrected.The X-axis comprehensive thermal error model was established according to the X-axis corrected thermal error model and the X-feed axis thermal error model.The Siemens 840 D system was used for thermal error compensation test.The thermal error was reduced by 54.5%,and the CP value was increased from 1.34 to 1.88.It is proved that this method of modeling and compensation is effective and feasible.