| 摘要 |
PURPOSE:To prevent hunting in stop control and to improve the stop precision of a rotating body by making the gain of a controller greater than a value before a stop when the rotating body stops. CONSTITUTION:When a main shaft 1 reaches a specific stop position and the output voltage of a magnetic sensor 10 drops to 0V, the main shaft 1 stops and a switch 17 is operated by the output signal of a comparator 16. Consequently, a voltage signal generated by dividing the output voltage of the sensor 10 through a variable resistor 18 is supplied to a thyristor Ward-Leonard device 6 through an amplifier 15. The level of the voltage signal supplied to the amplifier 15 is higher than that of a signal generated by the voltage division of a variable resistor 13 and the gain of the controller is increased after the main shaft 1 stops. Therefore, the holding force of the main shaft 1 for stopping against external force is increased. Thus, the hunting in stop control is prevented and the stop precision of the rotating body is improved. |
