JPH11270542A - Loosening preventive structure of tightening bolt and nut - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loosening preventive structure of tightening bolt and nut in which the bolt and nut in the tightened condition are not loosened layer by a third party. SOLUTION: In tightening bolt and nut comprising a tightening bolt 2 having a threaded part 2a to be inserted in a fitting hole 1 cut in structural members F1 , F2 to be tightened and a nut to be screwed in the threaded part 2a, a loosening preventive ring 5A having a cylindrical outer circumferential surface 5a and of the length L2 approximately equal to the thickness L1 of the nut is tightly fitted to the nut to obtain the loosening preventive structure of the tightening bolt and nut.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for tightening a structural member using bolts and nuts, and more particularly to a structure for preventing a tightened bolt and nut from being loosened later by a third party.

[0002]

2. Description of the Related Art As is well known, in a structural material such as a pipe tower of a transmission line, for example, it is common to tighten and fix two structural materials using a number of tightening bolts and nuts. Figure 5 shows a part of a conventional pipe towers, flange F to the corresponding end of the substructure X ₁ and an upper structural member X _2
1, F ₂ are formed respectively, between the mounting holes Y flanges F ₁ of which is formed a, F ₂ is fixed by a number of bolts and nuts tightening.

That is, these tightening bolts and nuts are provided with tightening bolts B to be inserted into the mounting holes Y, and the screw portions b of these tightening bolts B are tightened with a tightening nut such as a torque wrench. N is tightened in a substantially constant torque, the substructure X ₁ and the upper structural member X ₂ are integrated by tightening forces of the bolts and nuts tightening.

Incidentally, since such a structural material is installed outdoors, there is a risk that a tightening bolt / nut may be loosened by a third party using a spanner, a wrench, or the like. If the material is loosened or removed, there is a risk of collapse of the structural material. Of course, there is a danger that such tightening bolts and nuts will be loosened, in addition to the tightening nut N,
Since this also occurs when the lock nut is attached to the screw portion of the tightening bolt B, it is desired that there is no risk that the tightened tightening bolt and nut will be loosened later by a third party.

[0005] The problem of collapse of the structure due to the loosening of the tightening bolts and nuts is that even a large structure made of a channel steel material or the like, for example, a large bridge or a large crane, may cause a risk of loosening by a third party. It is being viewed as a problem.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional tightening bolts and nuts used for structural materials, and the bolts and nuts in the tightened state are used later. An object of the present invention is to provide a structure for preventing tightening bolts and nuts from being loosened without being loosened by a third party.

[0007]

In order to achieve this object, the present invention is directed to a tightening bolt having a screw portion inserted into a mounting hole formed in a tightening structural member and a nut screwed into the screw portion. The proposed tightening bolt / nut has a cylindrical outer peripheral surface and a tightening bolt / nut loosening prevention structure in which a loosening prevention ring having a length substantially equal to the thickness of the nut is tightly fitted to the nut. Is what you do.

In the following description of a preferred embodiment of the present invention, 1) a structure in which the anti-loosening ring is made of a short cylindrical pipe, and 2) the tightening bolt has a hexagonal head. 3) The nut is composed of a tightening nut and a lock nut screwed into the screw portion, and the anti-loosening ring has a thickness approximately equal to the thickness of the tightening nut and the lock nut. Structures of equal length are described.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIGS. 1 to 3 show a structure for preventing loosening of a tightening bolt / nut according to a first embodiment of the present invention. For example, two tightening structural members F ₁ and F ₂ which are flanges of a pipe tower or the like penetrate and mount. A hole 1 is formed, and a tightening bolt 2 inserted into the mounting hole 1 and a nut screwed into a screw portion 2a of the tightening bolt 2 secure the two tightening structural members F ₁ and F ₂ to each other. I will put it.

In the case of the first embodiment, a mounting hole 1 is formed between the fastening structural members F ₁ and F ₂ to be fixed, and a screw portion 2a of a tightening bolt 2 inserted into the mounting hole 1 is formed. The tightening nut 3 and the lock nut 4 are screwed in.
The tightening nut 3 and the lock nut 4 are tightened with a tightening tool such as a torque wrench while the rotation of the square head 2b is suppressed. Of course, the first embodiment has a structure in which the subsequent loosening of the tightening nut 3 is prevented by tightening the lock nut 4. 4 is omitted.

According to the present invention, the outer surfaces of the tightening nut 3 and the lock nut 4 and the hexagonal head 2b of the tightening bolt 2
Is an anti-loosening ring 5 whose outer peripheral surface 5a is a smooth cylindrical surface.
A, 5B. That is, the loosening prevention ring 5A fabricating the entire of a metal such as aluminum tubes or steel has been made with short cylindrical pipe, is substantially equal to the length L ₁ and the total thickness of the clamping nut 3 and a lock nut 4 in addition, loosening prevention ring 5B is substantially equal to the length L ₂ in the thickness of the hexagonal head 2b of the clamping bolt 2. As can be understood from FIG. 2, the cylindrical inner peripheral surface 5b of the anti-loosening rings 5A, 5B has a diameter d ₁ slightly smaller than the maximum diagonal dimension D _{1 of the} tightening nut 3 and the lock nut 4. The loosening prevention rings 5A and 5B have at least one inner surface formed with a tapered chamfer 6 for easily receiving the tightening nut 3, the lock nut 4, and the hexagonal head 2b.

Since the tightening bolt / nut loosening prevention structure according to the first embodiment has the above-described structure, after tightening the tightening nut 3 and the lock nut 4 on the screw portion 2a of the tightening bolt 2, Only by tightly fitting the anti-loosening rings 5A, 5B on the hexagonal head 2b, the tightening nut 3, and the lock nut 4 of the tightening bolt 2 using an impact tool such as a wood chip, the tightening is performed later. The nut 3 and the lock nut 4 are prevented from being loosened.

That is, the tapered chamfer 6 of the anti-loosening rings 5A and 5B is applied to the hexagonal head 2b of the lock nut 4 and the tightening bolt 2, and the anti-loose ring 5
A and 5B are tightly driven into the hexagonal heads 2b of the tightening nut 3, the lock nut 4, and the tightening bolt 2, respectively, so that a tightening tool such as a torque wrench can act on the tightening nut 3, the lock nut 4, and the like. The hexagonal head 2b of the tightening bolt 2 is covered with the anti-loosening rings 5A and 5B. For this reason, since the outer peripheral surfaces 5a of the anti-loosening rings 5A and 5B are smooth cylindrical surfaces, it is no longer possible to apply a tightening tool such as a torque wrench to the anti-loosening rings 5A and 5B.

Therefore, the tightening nut 3, the lock nut 4,
Loosening prevention ring 5A, 5 on hexagonal head 2b of tightening bolt 2.
In the tightened state where B is fixed, since the anti-loosening rings 5A and 5B cannot be rotated with a normal tightening tool, it is possible to avoid a subsequent loosening of the tightening nut 3, the lock nut 4, and the tightening bolt 2 by a third party. .

FIG. 4 shows an anti-loosening ring 5C used in a second embodiment of the present invention. In this embodiment, the outer peripheral surface 5a of the anti-loosening ring 5C is the same as that of the first embodiment.
Like A and 5B, it is a smooth cylindrical surface, but its inner peripheral surface 5b is a hexagonal hole. In addition, loosening prevention ring 5
The length of the C L ₃ is fastening nut 3, the lock nut 4, it is a length corresponding to the hexagonal head 2b of the clamping bolt 2. The reason for this is that the positional relationship in the rotational direction between the tightening nut 3 and the lock nut 4 in the tightened state is not specified, and the loosening prevention ring 5C having a length straddling both the tightening nut 3 and the lock nut 4 is used. This is because the structure is such that the corresponding anti-loosening ring 5B is driven each time the tightening nut 3 and the lock nut 4 are tightened, since the meaning is lost.

In each of the above-described embodiments, an example is shown in which the inner space of the anti-loosening rings 5A to 5C does not contain any filler, but in the present invention, these anti-loosening rings 5A to 5C are used. Filling the interior space with a filling compound to prevent adhesive and rust,
This has the effect of further enhancing the loosening prevention effect and improving the durability of the tightening portion of the tightening structural member.

[0017]

As is apparent from the above description, according to the present invention, the nut screwed into the screw portion of the tightening bolt is covered with the anti-loosening ring, so that the tightening bolt for fastening between the tightening structural members is provided. The risk that the space between the nut and the nut is later loosened by a third party can be avoided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a loosening prevention structure according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the anti-loosening ring, taken along line 2-2 in FIG. 1;

FIG. 3 is an explanatory view of a fastening step of the loosening prevention structure.

FIG. 4 is a perspective view of a loosening prevention ring used in a loosening prevention structure according to a second embodiment of the present invention.

FIG. 5 is an enlarged perspective view of a main part of a conventional pipe tower.

[Explanation of symbols]

F ₁ , F ₂ Tightening structural material 1 Mounting hole 2 Tightening bolt 2a Screw 2b Hexagonal head 3 Tightening nut 4 Lock nut 5A, 5B, 5C Anti-loosening ring 5a Outer surface 5b Inner surface

Claims (4)

[Claims] 1. A cylindrical outer peripheral surface of a tightening bolt and nut comprising a tightening bolt having a screw portion inserted into a mounting hole formed in a tightening structural member and a nut screwed into the screw portion. A tightening bolt / nut loosening prevention structure, wherein a loosening prevention ring having a length substantially equal to the thickness of the nut is tightly fitted to the nut. 2. The loosening prevention structure for a tightening bolt and nut according to claim 1, wherein said loosening prevention ring is formed of a short cylindrical pipe. 3. The fastening bolt has a hexagonal head.
2. The loosening prevention structure for a tightening bolt and nut according to claim 1, wherein the loosening prevention ring is tightly fitted also to the corner head. 4. The nut comprises a tightening nut and a lock nut screwed into the screw portion, and the anti-loosening ring has a length substantially equal to the thickness of the tightening nut and the lock nut. A structure for preventing loosening of a tightening bolt / nut according to claim 1.