| 摘要 |
An improved hand-held power tool is provided which can effectively reduce whirling vibration caused by imbalance of a rotating element. The power tool has a grip 109 that is connected to a tool body 103 and designed to be held by a user and a self-synchronous mechanism 121 that reduces whirling vibration caused in the tool body 103 or the grip 109 when the tool bit 113 is driven. The self-synchronous mechanism 121 is of a phase variable type, having a rotating body 125 which serves as a vibrator and is rotationally driven by a driving source 123 different from a driving source for the tool bit 113. The self-synchronous mechanism 121 is disposed in the tool body 103 or the grip 109 in which whirling vibration is caused, and arranged such that a phase of vibration of the rotating body 125 is automatically tuned to a phase of the whirling vibration, thereby reducing the whirling vibration. |
