数控车床综合热误差建模及工程应用

Comprehensive thermal error modeling for NC lathe in engineering application

摘要:

针对车床实际工程应用中主轴与进给轴综合误差对工件加工精度产生影响问题，建立包含工件膨胀效应的主轴与进给轴综合热误差模型，并进行实际切削验证.以精密车床为研究对象，综合分析车床主轴、进给轴和工件在实际加工中的相互影响关系，并建立三者之间的综合热误差多元线性回归模型（MLRA）.实验结果表明：含有工件膨胀效应系数的综合热误差模型符合实际工况，有效提高了车床的加工精度.主轴热误差模型的预测精度达85%以上，进给轴预测精度达70%以上，实际加工中工件误差由15 μm降低到5 μm左右.综合热误差模型显著提高了高精密数控车床的加工精度.

Abstract:

The coupled thermal error between the spindle and feed shaft could actrually reduce the accuracy of workpieces in prcessing. For the problem, we developed the conprehensive thermal error model of spindle and feed shaft, with the expansion of workpieces, and verified it. The mutual effection among spindle, feed shaft and workpiece were comprehensively analyzed, and the multivariable linear regression model was developed among them. The results show that the comprehensive model could be consistent with lathe's processing situation and increase the processing accuracy effectively. The prediction accuracy for the spindle is more than 85%, and 70% for feed shaft. The error rang in processing is declined from 15 μm to 5 μm.