| 摘要 |
PURPOSE:To considerably improve speed accuracy and also spinning accuracy by feeding the rotating speed of each spindle drive motor back to a corresponding spindle driving inverter. CONSTITUTION:For a spindle drive motor 5, a speed feedback type motor performing speed control by speed feedback is used. An inverter corresponding to each speed feedback motor for spindle drive is automatically controlled in such a manner that its output frequency will coincide with the set frequency. That is, the speed is held to a set point without being affected by the fluctuations in load or power received. The set point is a common speed command input to each inverter 3-n. In this way, the speed accuracy of the spindle driven by a speed feedback type motor is greatly improved oven that for driving by induction motor. |
