| 摘要 |
An electric drill driver (1) includes a motor (21), a gearshift unit (80), a gearshift motor (61), a gearshift actuator (63) that drives the gearshift motor when switching a speed reduction ratio of the gearshift unit, a detector (64) that outputs a detection voltage VD based on the drive condition of the gearshift motor, and a control unit (35). The control unit includes a high potential side threshold VthH and a low potential side threshold VthL for determining the switching of the speed reduction ratio of the gearshift unit, and controls the rotation of the motor based on a comparison of the detection voltage VD output by the detector and the determination threshold. The control unit corrects the determination threshold based on a second maximum detection voltage Vmax2 and a second minimum detection voltage Vmin2 of the detection voltage VD acquired from the detector. |
