Numerically controlled machine tool

摘要

A numerically controlled machine tool for machining a non-circular workpiece according to profile data. The numerical controller of the machine tool memorizes the ideal profile data calculated from the ideal final shape of the workpiece, and the execution profile data calculated from the ideal profile data and compensated for position error due to the follow delay of the machine tool. The machine tool is controlled according to the execution profile data during grinding the workpiece with cut-in feed and spark-out grinding. The numerical controller has the capability of measuring posiiton change of the main spindle and the tool slide during spark-out grinding. Then, the numerical controller ascertains whether or not the follow delays of the main spindle and the tool slide are within a prescribed tolerance depending on the measured position change and the ideal profile data.