| 摘要 |
A method and a power wrench for detecting the attainment of a target torque level in a screw joint tightening process, wherein an override type torque responsive release clutch (17) is used in the power wrench for defining the target torque level, comprising a microphone (22) mounted in the power wrench for recording the "click" sound developed in the clutch (17) during the release movement, and a control unit (20) including motor operation governing means, and a signal identifying device is connected to the microphone (22) for recognising the release "click" sound and delivering a stop signal for interrupting the power supply to and braking the power wrench motor (15) as the clutch (17) has released and the target torque level is reached. |
