摘要 |
A tapping machine (1) executes a tapping operation by operating a spindle motor (21) and a feed axis motor (31) in synchronization, and includes a spindle reversal detector unit (34) for detecting the reversed operation of the spindle during the tapping operation, and a reverse correction amount production unit (35) for producing a reverse correction amount for improving follow-up performance of reversed operation of the feed axis at the time when the reversed operation of the spindle is detected by the spindle reversal detector unit (34). When the reversed operation is detected by the spindle reversal detector unit, the reverse correction amount produced by the reverse correction amount production unit (35) is added to the speed instruction on a speed control loop of the feed axis control unit (30) or to an integrator (41) of the speed control loop. |