| 摘要 |
PROBLEM TO BE SOLVED: To make torque controllable singly by an impact wrench. SOLUTION: An impact wrench 4 is rotatably supported through bearings 2, 3 to an inner side of a wrench supporting case 1, a torque ensuring means 5 is provided between the impact wrench 4 and the wrench supporting case 1. The torque ensuring means 5 is provided with a push bar 13 integrally and rotatably fixed to a side of the impact wrench 4 and a coil spring fixing one end to a side of the wrench supporting case 1, the coil spring turns the push bar 13 energized to a tightening side to support reference tightening torque. When rotation of a bolt is stopped by tightening of the impact wrench 4, it is reversely rotated by reaction force thereof, tightening of prescribed torque is completed when elastic force of the coil spring is overcome, and the torque is ensured by this reverse rotation.
|
