高精度数控机床主轴系统热误差的控制方法

A New Thermal Error Control Method for Spindle System of High Precision Computer Numerical Control Machine Tools

为了解决高精度数控机床主轴系统热误差的难题,提出了一种主动控制主轴热误差的新方法.根据设计的螺旋盘管冷却器,分析了硅脂厚度对主轴与冷却器间的接触热阻的影响规律,建立了热阻模型.在简化主轴系统模型的基础上,构建了主轴系统的热-流-固有限元模型,并对冷却参数进行了仿真.利用搭建的温度控制系统,对有限元模型进行验证.结果表明,有限元模型能有效预测主轴系统热特性的变化规律,其冷却器的换热效率高,热平衡时间缩短了约68%,热误差减小了约19%.本研究为精密机床主轴热误差控制提供了一种新思路.

In order to solve the problem of thermal errors in the spindle system of high precision computer numerical control(CNC)machine tools,a novel active control method for spindle thermal deformation was proposed.Besides,a helical coil cooler was designed,the influence of silicone grease thickness on the contact thermal resistance between a spindle and a cooler was analyzed,and a thermal resistance model was established.Based on the simplified spindle system,a thermal-fluid-solid finite element model was constructed,and the cooling parameters were simulated.The finite element model was verified by using a temperature control system.The results show that the finite element model can effectively predict the variation of thermal characteristics of the spindle system.The cooler has a high heat exchange efficiency,the thermal equilibration time is reduced by 68%,and the thermal error is reduced by 19%.This study provides a new idea for thermal error control of precision machine tool spindle.