| 摘要 |
PROBLEM TO BE SOLVED: To provide a reverse rotation preventive structure of a screw body which reliably prevents rotation in a specified direction of the screw body with a simple structure.SOLUTION: A reverse rotation preventive structure is a structure which fastens a member 80 to be fastened by means of a male screw body 10 and a washer 50, a screw body side seating part 22 is formed on the male screw body 10, a first reception part 60 and a second reception part 70 are formed on the washer 50 side, and a member side seating part 82 is formed on the member 80 to be fastened. A first engagement mechanism A is formed between the first reception 60 and the screw body side seating part 22, when at least the screw body side seating part 22 starts to rotate in the direction of relaxing the male screw body 10 in the fastened state, the first reception part 60 and the screw body side seating part 22 are engaged with each other to prevent relative rotation of them, a second engagement mechanism B is formed between the member side seating part 82 and the second reception part 70 and, when at least the washer 50 starts to rotate in the direction of relaxing the washer 50, the first reception part 70 and the member side seating part 82 are engaged with each other to prevent relative rotation of them and relaxation of the male screw body 10 and the member 80 to be fastened is prevented by the action of the first engagement mechanism A and the second engagement mechanism B. |
