| 摘要 |
In a non-circular workpiece grinding machine (2), a proximity sensor (20a) is arranged to face a non-circular portion of a workpiece (W) 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 (13) is rotating in a low speed rotational phase region in which the work spindle is controlled by a numerical controller (22) 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. |
