| 摘要 |
The present invention relates to a method for tightening a torque-shear type high-strength bolt using a torque-control type electric wrench, which comprises a targeted-tightening torque setting step, a torque applying step, and a pin tail fracturing step. In the targeted-tightening torque, to tighten the torque-shear type high-strength bolt by a predetermined standard axial force, a control part calculating the torque constant of the torque-shear type high-strength bolt calculates a targeted tightening torque due to the calculated torque constant. In the torque applying step, until a torque applied to a nut coupled to the torque-shear type high-strength bolt reaches the targeted tightening torque calculated in the target tightening torque calculating step, an outer socket part is rotated to apply the torque to the nut. In the pin tail fracturing step, when the torque applied to the nut reaches the targeted tightening torque, the rotation of the outer socket part is stopped and an inner socket part is rotated to fracture the pin tail of the torque-shear type high-strength bolt. According to an embodiment of the prevent invention, by being coupled to each other by the targeted tightening axial force when the tightening torque is applied to the nut in consideration of the variable torque constant, the bolt and the nut can be prevented from being tightened to each other by a tightening axial force with a value smaller than or equal to a reference value. |
