| 摘要 |
PURPOSE:To readily perform screw tightening with excellent accuracy by detecting the voltages across both terminals of a series field winding or an armature, comparing and detecting the output torque of a motor, and improving the accuracy of detection. CONSTITUTION:A voltage detector 3 is connected across both terminals of a series field winding 2 of a series motor or a compound motor. The output of said voltage detector 3 is fed into a comparator 4 and compared with a reference voltage Ex, thereby the output torque of the motor is compared and detected. The voltage detector can be connected across both terminals of an armature 1, and the output torque of the motor is compared and detected by the same procedure. Since the detection is made by the voltage whose magnitude of variation is large compared with the detection of the output torque of the motor by current detection, the detector circuit can be simplified, accuracy of the detection is high, and the tightening of screws can be performed very accurately. |
