磨削加工中滚珠丝杠温度场仿真与实验

Temperature Simulation and Experiment of Ball Screw in Grinding Process

螺距精度是丝杠磨削加工的重要指标,累积螺距误差对丝杠定位精度起着决定性作用。砂轮磨削丝杠产生的大量热量通过磨削接触区域按照一定比例传入工件,工件受热伸长而导致的丝杠滚道行程误差会直接反映在螺距误差上。基于若干简化条件,采用有限元法对磨削加工丝杠温度场进行瞬态热分析,并利用红外热像仪构建了磨削加工中丝杠温度测量实验系统,获得了可视化的丝杠热信息,分析了无冷却磨削时工艺参数对加工过程中不同时刻工件温度场分布以及热伸长的影响,有助于丝杠磨削加工的螺距精度控制。

Pitch accuracy is one of the main indexes of screw form grinding because its accumulated error plays a decisive role in the positioning accuracy of ball screw.The great amount of heat produced in grinding is conducted into the workpiece through the grind-ing contact area proportionally,which causes the axial thermal elongation of screw and then deteriorates the screw pitch accuracy obvi-ously.Based on some simplified conditions,the finite element method was used to do transient thermal analysis on temperature field of screw.The infrared thermal imager was utilized to establish the experiment system for screw temperature measurement in grinding process.According to the thermal imagines of screw,the influence of machining parameters on the temperature distribution and thermal elongation of workpiece at different time in dry grinding was analyzed,which was helpful to ensure the pitch accuracy of ball screw.