Abstract: A tightening device and a tightening method are able to check that a fastening member has been fastened to a desired set torque or greater after being tightened, without loosening the fastening member.

Abstract: A tightening device is able to check that a fastening member has been fastened to a desired set torque or greater after being tightened, without loosening the fastening member.

Abstract: A tightening device and a tightening method are able to check that a fastening member has been fastened to a desired set torque or greater after being tightened, without loosening the fastening member.

Abstract: A tightening device is able to check that a fastening member has been fastened to a desired set torque or greater after being tightened, without loosening the fastening member.

Abstract: A tightening machine has a socket unit which tightens a reaction washer and a nut to each other. The socket unit includes an inner socket whose tip end can engage with the nut, and an outer socket formed concentrically with the inner socket. A tip end of the outer socket can engage with the reaction washer. The socket unit concentrically includes an inner socket holder and an outer socket holder. The inner socket holder and the outer socket holder can rotate in opposite directions from each other, and the outer socket holder is formed around an outer periphery of the inner socket holder. The inner socket is detachably engaged with the inner socket holder, and the outer socket is detachably engaged with the outer socket holder. The inner socket is engaged with the inner socket holder with clearance in its circumferential direction.

Abstract: A tightening machine has a socket unit which tightens a reaction washer and a nut to each other. The socket unit includes an inner socket whose tip end can engage with the nut, and an outer socket formed concentrically with the inner socket. A tip end of the outer socket can engage with the reaction washer. The socket unit concentrically includes an inner socket holder and an outer socket holder. The inner socket holder and the outer socket holder can rotate in opposite directions from each other, and the outer socket holder is formed around an outer periphery of the inner socket holder. The inner socket is detachably engaged with the inner socket holder, and the outer socket is detachably engaged with the outer socket holder. The inner socket is engaged with the inner socket holder with clearance in its circumferential direction.

Abstract: A controller compares a minimum value of power source voltage which decreases in association with starting current generated upon start of a motor with a threshold value in a storing unit. When the minimum value is less than the threshold value, the controller notifies of shortage of the power source terminal voltage, and stops the motor. The controller also compares a value obtained by integrating the power source voltage which decreases in association with starting current generated upon start of the motor for only predetermined time with the threshold value in the storing unit, when the integral value is less than the threshold value, notifies of shortage of the power source terminal voltage, and stops the motor.

Abstract: A controller compares a minimum value of power source voltage which decreases in association with starting current generated upon start of a motor with a threshold value in a storing unit. When the minimum value is less than the threshold value, the controller notifies of shortage of the power source terminal voltage, and stops the motor. The controller also compares a value obtained by integrating the power source voltage which decreases in association with starting current generated upon start of the motor for only predetermined time with the threshold value in the storing unit, when the integral value is less than the threshold value, notifies of shortage of the power source terminal voltage, and stops the motor.

Abstract: A bolt or nut tightening device comprising a tightening socket (4) and a reaction force receiving member (5), the tightening socket (4) being rotatingly drivable upon a speed reduction by a motor (2) and a reduction mechanism (3) which are incorporated in the device, the motor (2) being coupled to a controller (7), the controller (7) being operable to deenergize the motor (2) in response to a tightening completion signal of detecting means (70) for detecting the completion of tightening of a bolt or nut and to reversely rotate the motor (2) only for a moment upon lapse of a predetermined period of time taken for inertial rotation of the motor (2) to reduce to an extent neglectable for the reverse rotation of the motor (2) after the deenergization, whereby the propping action of the reaction force receiving member (5) is nullified.

Abstract: A bolt or nut tightening device comprising a tightening socket (4) and a reaction force receiving member (5), the tightening socket (4) being rotatingly drivable upon a speed reduction by a motor (2) and a reduction mechanism (3) which are incorporated in the device, the motor (2) being coupled to a controller (7), the controller (7) being operable to deenergize the motor (2) in response to a tightening completion signal of detecting means (70) for detecting the completion of tightening of a bolt or nut and to reversely rotate the motor (2) only for a moment upon lapse of a predetermined period of time taken for inertial rotation of the motor (2) to reduce to an extent neglectable for the reverse rotation of the motor (2) after the deenergization, whereby the propping action of the reaction force receiving member (5) is nullified.