摘要 |
<p>In a machine tool having a rotary shaft for use in rotating a tool or a workpiece, a plurality of stable rotation speeds at which the chatter vibrations are expected to be suppressed, and at least one switching rotation speed across which a dynamic characteristic of a rotary shaft system changes are stored. The plurality of stable rotation speeds may be determined from chatter vibrations detected using a vibration detection unit. Optimum rotation speed that is a rotation speed to which a rotation speed of the rotary shaft is changeable without crossing the switching rotation speed is selected from the plurality of stable rotation speeds, and the rotation speed of the rotary shaft is changed to the optimum rotation speed. Thus, chatter vibrations generated during rotation of the rotary shaft can be suppressed effectively.</p> |