Patent ID: 7823465
Filing Date: 2010-11-02
Classification: B23P,B25B,Y10T

Abstract:
1. A bolt fastening method, in which plural bolts are fastened up to a predetermined snug torque and then the bolts are further fastened by a specified angle from a bolt angle corresponding to the snug torque, the method comprising steps of: obtaining a fastening-angle start standard point based on torque characteristics of fastening of the bolts; selecting a specified bolt among the plural bolts as a standard bolt; obtaining a standard fastening angle of said standard bolt at a point where a fastening torque of the standard bolt has reached the snug torque from said fastening-angle start standard point; obtaining a fastening angle of the bolt to be fastened at a point where a fastening torque of the bolt to be fastened has reached the snug torque from said fastening-angle start standard point; obtaining an angle-variation difference between said standard fastening angle of the standard bolt and said fastening angle of the bolt to be fastened; and setting said specified angle to be additionally fastened for the bolt to be fastened at a certain amount of angle which is obtained by adding said angle-variation difference to a base angle of the specified angle.