| 摘要 |
A fluid impulse torque tool used for tightening screws has an air motor (10), which drives an oil pressure pulse generator (11), which produces torque pulses to rotate a driving head (39). The driving head (39) stops automatically when a predetermined tightening force is attained. A piston (51) is actuated by relief oil from a relief valve (40) attached to the oil pressure pulse generator (11). The action of a shutoff valve (63), placed in an air feed passageway (66) to an air motor (10), is controlled by the piston (51). In screw tightening operation, when a predetermined tightening force is attained, relief oil is p roduced to move the piston (51), and this movement is transmitted via a rod (54) to an actuating member (56), which moves to allow the valve body (63) to close under air pressure shutting the air feed passageway (66) to the air motor, so that the latter is stopped. |
