| 摘要 |
The objective is to prevent the loosening of a structure with which a member (80) to be fastened and a base material (90) are fastened by means of a male screw body (10) and a washer (50). A screw-body-side seat part (22) is formed on the male screw body (10), and a first receiving part (60) and second receiving part (70) are formed on the washer side. A member-side seat part (82) is formed on the member (80) to be fastened. The first receiving part (60) and the screw-body-side seat part (22) have sawtooth-shaped recesses and protrusions. When an attempt is made to rotate the male screw body (10) in the direction of loosening, the recesses and protrusions engage one another, thereby preventing rotation. A recessed housing part of the member-side seat part (82) and the outer wall of the second receiving part (70) of the washer (50) have an eccentric circular shape. When an attempt is made to rotate the washer (50) in the direction of loosening, the eccentric circular shapes engage one another, thereby preventing rotation. |
