抄録
It is known by past researches on the loosening of a screw that rotation of loosen will arise if the radius direction vibration is given to a bolt head or the bearing surface of a nut. On the other hand, it is known that it is effective in ultrasonic vibration reducing apparent friction, and the method of performing screw tightening with little variation is also studied, it is performed by tightening with the ultrasonic vibration. In use of ultrasonic vibration, a stronger effect can be acquired by using resonance. In this research, the bolt head or the nut was fastened with axial ultrasonic vibration by vibration resonance, and it is investigated about the effect.
