| 摘要 |
PROBLEM TO BE SOLVED: To provide a machine tool capable of performing a machining work without bringing about chattering vibration, even without a preliminary test machining and without the use of a vibration measurement sensor.SOLUTION: A machine tool 1 includes a main spindle 5 for rotating a boring tool 7, a feed shaft for relatively moving a tool and a workpiece W, and a torque detection part 352 for detecting a load torque of the main spindle 6 in the machining. The machine tool measures an extreme value time interval &Dgr;t, &Dgr;t, &Dgr;tbeing a time interval between adjacent maximum values P, P, P, Pof the load torque fluctuation in machining the workpiece W, determines that the chattering vibration has occurred when the number of times at which the consecutive extreme value time interval becomes the same value reaches a predetermined number, and changes rotational speed of the main spindle. |
