| 摘要 |
PURPOSE:To prevent polishing unevenness from being produced by successively monitoring a load current of a polishing member turning motor and controlling a pressure adjusting motor such that its difference from a set load current is zero. CONSTITUTION:When a load current in responce to the thickness of a metal plate 14 to be polished is set to a load current setter 24, a signal comparator 26 compares this with an ordinary load current, and issues a signal to a pressure control device 22 to drive a pressure adjusting motor 10, allowing pressure to be adjusted to that responsive to the thickness. And, a polishing member 12 is turned in a state where a rotation control device 18 controls the driving of a turning motor 8, allowing the metal plate 14 to be polished. Namely, during the polishing, the control device 18 monitors a load current of the motor 8, and sends a signal to the comparator 26, which comparator 26 evaluates a difference between a set value from the setter 24 and the load current of the motor 8, thus allowing the pressure control motor 10 to be controlled by said signal via the pressure control device 22. In such a way, the polishing amount per unit time can be made constant irrespective of the shape of the metal plate. |
