| 摘要 |
PURPOSE:To maintain the number of revolutions of a motor constant even if the load applied to a driving motor fluctuates by providing a speed deviation operating part, which compares the output from a speed detecting part with the set value from the number of revolutions setting part, and a voltage control part, which controls the voltage to be applied to a driving motor by the output from this speed deviation operating part. CONSTITUTION:When the number of revolutions of a driving motor fluctuates according to the load at polishing and grinding, a speed detecting part 18 detects this number of revolutions. It is checked what number of revolutions a grindstone actually rotates at by the speed indication part connected to this detecting part 18. Furthermore, the number of revolutions detected by the speed detecting part 18 is compared with the setting number being set by the number of revolutions setting part 19 and is operated in a speed deviation operating part 20. That operation result is output to a voltage control part 15, and the voltage to be applied to a driving motor is adjusted so that the actual number of revolutions may accord with the setting number by this voltage control part 15. |
