Detecting device for abnormal workpiece rotation in non-circular workpiece grinding machine

摘要

In a non-circular workpiece grinding machine, a proximity sensor is arranged to face a non-circular portion of a workpiece for sensing a maximum diameter portion of the non-circular portion to detect that the maximum diameter portion is rotating in a detection phase section when the work spindle is rotating in a low speed rotational phase region in which the work spindle is controlled by a numerical controller to rotate at a low speed. Abnormality judging means is provided for judging that an abnormal workpiece rotation is occurring when the maximum diameter portion of the non-circular portion is not detected by the proximity sensor in the state that the work spindle is rotating in the low speed rotational phase region.