| 摘要 |
PROBLEM TO BE SOLVED: To provide a device for preventing loosening of a nut, which securely exhibits a function of preventing loosening of the nut, has high operability, and is reduced in cost.SOLUTION: A device for preventing loosening of a nut, includes a bolt 14 for fixing members to be fixed 11 and 12, a first nut 16, and a second nut 18. The first nut 16 includes a small-diameter portion 34 that protrudes to a side opposite to the member to be fixed 12 and has a taper face 34a whose diameter decreases toward the tip end side thereof. A tapered fitting face 38 to be fitted to the small-diameter portion 34 of the first nut 16 is formed in the second nut 18, and the second nut 18 is screwed to the bolt 14. The members to be fixed 11 and 12 are fastened by the first nut 16, and the second nut 18 is fastened while the fitting face 38 of the second nut 18 is fitted to the small-diameter portion 34 of the first nut 16, so that the small-diameter portion 34 of the first nut 16 is reduced in diameter to be press-contacted to the bolt 14. |
