TORQUE CONTROL APPARATUS OF IMPACT POWER TOOLS

摘要

The present invention relates to an electric-drive tool and more specifically to a torque controller of an electric-drive tool capable of adjusting the limit of torque for an electric-drive tool comprising a motor unit to provide the torque and a torque limiter installed between the motor unit and a driving shaft performing a task with the torque transmitted from the motor unit to shut down the torque when the torque transmitted to the driving shaft exceeds a preset torque value. The torque controller according to the present invention comprises: a ring-shaped wheel member (100) to receive torque from the motor unit; a number of balls (200) in contact with the wheel member (100) to transmit the torque; a ring-shaped clutch plate (300) in contact with the balls (200) to transmit the torque to the driving shaft and move in the axial direction; a torque spring unit (400) that is connected to the clutch plate (300) at one end that applies elasticity to the balls (200) in the axial direction; and a torque control unit (500) that changes the preset torque by moving closer to or farther away from the other end of the torque spring unit (400). The torque spring unit (400) comprises a number of springs which extend in the axial direction but to different extents from the clutch plate (300) when the torque spring unit is connected to the clutch plate (300).