| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power tool such as an oil pulse tool having a brushless motor which is increased in tightening torque due to angle advancement and eliminates variations in the tightening torque caused by the angle advancement. <P>SOLUTION: This oil pulse tool includes the brushless motor, a drive circuit configured to apply a drive voltage to any of the stator windings of the brushless motor at a predetermined timing, an oil pulse mechanism portion 20 configured to be rotatingly driven by the brushless motor, and an output shaft which is connected to the oil pulse mechanism portion 20. The drive circuit changes the advance angles (76, 77) of the drive voltage provided to the brushless motor according to a rotational position of the oil pulse mechanism portion. The oil pulse mechanism portion 20 is constituted of a liner 21 and a main shaft 23. The advance angle of the drive voltage is changed according to the relative rotational positions (78, 79) of the liner 21 and the main shaft 23. <P>COPYRIGHT: (C)2012,JPO&INPIT |
