JPH09177746A - Bolt and screw - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of impact force to be generated by load in the direction perpendicular on a shaft and shear fracture to be generated by the continuous action of vibration, by providing a shock absorbing part composed of a laminated body in which elastic bodies and fibers are alternately laminated on the shaft part. SOLUTION: After a band body 7 in which rubber 6 is rolled and bonded to both surfaces of a cloth 5 formed of natural, synthetic, or metallic fibers is formed, it is bonded to a processing surface of a shaft part 4 of a bolt main body 1, and is wound a required time to form a laminated body 8 and taken as a shock absorbing part 9, and the peripheral surface is covered with a pressure tape or a metal mold. After that, the shaft part 4 and the laminated body 8 are integrated with each other by heating, and the pressure tape is removed. The laminating amount is determined according to the using part of the bolt and to the purpose. Accordingly, the deformation the shock absorbing part 9 is restricted in fastening by the nut 16 by setting the hole diameter of a body to be connected to such a diameter that the shock absorbing part 9 is just fitted, and resistance force of the shock absorbing part 9 in acting of impact force to the shaft part is larger than the case where the nut is loosely fitted. When kinetic energy is transmitted from the outside, since the energy can be absorbed by the shock absorbing part 9, shearing resistance force can be improved.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bolt or screw coated with an elastic material such as rubber.

[0002]

2. Description of the Related Art A spiral is engraved around a bolt or screw (screw).
Screws are generally used to connect or fix two objects, structures or the like by screwing them into a fixed body.

[0003]

Such bolts and screws (hereinafter referred to as bolts) are connected or fixed by their tightening force, and the line of action of the force is the axis line of the bolt. Therefore, there is a problem that an impact force is generated when a load in the direction perpendicular to the shaft (shear direction) is applied, and the bolt causes shear fracture when vibration is continuously applied.

[0004]

In the bolt and the screw, a buffer portion is provided on the shaft portion by a laminated body formed by alternately laminating elastic bodies and fibers.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional explanatory view showing the first embodiment, FIG. 2 is an explanatory view showing a tightened state, and FIG. 3 is a characteristic diagram with respect to a shearing force generated in a bolt. Then, the peripheral surface of the shaft portion 4 is subjected to a base treatment and a pretreatment for adhering to an elastic body such as rubber or synthetic resin (hereinafter referred to as rubber).

As shown in FIG. 4, a band 7 having a required width is formed by rolling and adhering a rubber 6 on both surfaces of a cloth 5 made of fibers made of natural, synthetic or metal, and the band 7 is previously formed. After adhering to the processed surface of the shaft portion 4 of the above, the laminated body 8 is formed by laminating the desired number of the band bodies 7 by winding the required number of times to form a buffer portion 9, and the peripheral surface of the buffer portion 9 is a pressing tape, a mold, or the like. Cover with. Then, a heating reaction (vulcanization) is performed to integrate the shaft portion 4 and the laminated body 8. The pressing tape, mold, etc. are removed after the heating reaction.

The amount of lamination by the laminated body 8 is appropriately determined according to the use place and purpose of use of the bolts, and the lamination interval is also the same, and the interval width is sequentially increased from the outer side to the inner side. You can change it. In addition, the laminated body 8
An elastic body layer may be further formed on the inside or the outside of the, and an elastic body layer may be formed on both of them to form the buffer portion 9.

According to the above construction, the bolt can be attached with a normal tool, and for example, as shown in FIG. 2, the laminated body 8 has a diameter or a diameter which allows the laminated body 8 to be fitted to the coupled bodies 11 and 12 to be coupled. The holes 13 and 14 are opened, the washer 15 is fitted, and the nut 16 is tightened to connect them.
The buffer portion 9 of the bolt thus configured can improve the spring property by restraining the horizontal displacement of the rubber by the adhesive force with the fiber 5. The spring property is the number of layers, the pitch, and the fiber. And the material of the elastic body.

Therefore, when an external force in the shearing direction acts, the cushioning portion 9 exerts a cushioning effect, and even when an acting force having an angle acts, the conventional bolt is bent in addition to the axial force and the shearing force. While a moment is generated and the bolt is damaged, in the bolt of the present invention, since the relevant portion is inclined and responds, only the axial force and the shearing force in the direction perpendicular to the axis act on the central bolt body. This will prevent damage to the bolt.

Therefore, if the diameters of the holes 13 and 14 formed in the connected bodies 11 and 12 are such that the shock-absorbing portion 9 fits exactly, the deformation of the shock-absorbing portion 9 is restrained when tightened by the nut 16. The resistance force of the buffer portion 9 when an impact force acts on the shaft portion is greater than that when the shock absorbing portion 9 is loosely fitted. Further, when kinetic energy is transmitted from the outside, since the kinetic energy can be absorbed by the buffer portion 9, the amount of energy transmitted to the bolt main body 1 is reduced, so that the energy destruction of the bolt main body 1 is destroyed. Is also prevented. This means that, as shown in FIG. 3, when the same energy is applied to the normal bolt and the bolt of the present invention (hatched portion),
It can be seen that the displacement amount in the buffer portion 9 is large (δF> δV), but the generated reaction force is small (PF <PV), so that the shear strength of the bolt body is improved.

The shape of the bolt main body 1 is not limited to the above-mentioned shape, and the buffer portion 9 does not necessarily have to have a diameter larger than the head portion 2 of the bolt main body. As shown in FIG. 5, the diameter of the buffer 9 is equal to that of the head 2.
May have the same diameter as or smaller than. Further, as shown in FIG. 6, the spiral portion 10 ahead of the shaft portion 4 having the buffer portion 9 is formed.
May have a larger diameter.

Further, although the above description has been made with bolts, as shown in FIG. 7, the structure in which the buffer portion 9 by the laminated body 8 is similarly formed on the shaft portion of the screw (screw) can also be adopted. The same action and effect as above can be obtained. Next,
Another example of the use of the above bolts will be explained. As shown in FIG. 8, the chain 16 is kept in a state in which the respective rings 17 constituting the chain 16 are spaced from each other, and the elasticity of rubber or synthetic resin is also provided between the rings 17. Elastic body 18 with body 18 interposed
There is an elastic support member 19 embedded therein. When the elastic support member 19 is used as a connecting member between two objects 20, 21 such as a bridge girder, the elastic support member 19 is fixed to each object. By using the bolt of the invention, when vibration is applied between two objects due to an earthquake or the like, the distance between the two objects continuously changes due to the vibration, but the elastic support member 19 used as the connecting member vibrates. The impact force generated in the elastic support member 19 is prevented by following the displacement as if absorbing the displacement.

However, the elastic support member 19 and the object 20,
When a conventional normal bolt is used at the connection point with 21, the shock is applied to the bolt even though it is buffered by the elastic support member 19, and the bolt may be destroyed. However, according to the bolt of the present invention, the impact force is buffered by the buffer portion 9 of the bolt body, and the bolt can be prevented from being broken.

Further, as shown in FIG. 9, if the anchor bolts of the present invention are used for attaching a collision avoidance of the median strip of a highway, a large amount of energy can be absorbed. In such a case, the fiber used for the laminate 8 may be high-strength fiber such as Kepler or carbon fiber.

[0015]

According to the present invention described in detail above, by providing a buffer portion by a laminated body formed by alternately laminating elastic bodies and fibers on a shaft portion of a bolt or a screw (screw),
By connecting and fixing two objects with this bolt or screw, if a shearing force acts on this bolt, the laminated body buffers the external force, and the external force acting on the bolt body is reduced to prevent damage to the bolt body. It is also possible to suppress the occurrence of impact force itself.

As a result, the safety of the two objects can be improved and, for example, a seismic resistant structure of a bridge girder or a connecting portion of a highway can be provided.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional explanatory view showing a first embodiment example.

[Fig. 2] Characteristic diagram for the shearing force generated in the bolt

FIG. 3 is an explanatory view showing a tightened state of bolts.

FIG. 4 is an enlarged cross-sectional explanatory view of a strip.

FIG. 5 is a partial cross-sectional explanatory view showing a second embodiment example.

FIG. 6 is a partial cross-sectional explanatory view showing a third embodiment example.

FIG. 7 is a partial cross-sectional explanatory view showing a fourth embodiment example.

FIG. 8 is an explanatory diagram showing a usage example.

FIG. 9 is an explanatory diagram showing a usage example.

[Explanation of symbols]

 1 Bolt body 2 Head 3 Washer 4 Shaft 5 Fiber 6 Rubber 7 Band 8 Laminated body 9 Buffer part 11, 12 Connected body 13, 14 Hole 15 Washer 16 Nut

Claims (7)

[Claims] 1. A bolt and a screw, characterized in that a shock absorbing portion is provided on the shaft portion by a laminated body formed by alternately laminating elastic bodies and fibers. 2. The bolt and the screw according to claim 1, wherein a washer is provided immediately below the head to form a buffer portion formed by the laminated body. 3. The bolt and the screw according to claim 1, wherein the laminated body is provided in an elastic body to form a buffer portion. 4. The bolt and the screw according to claim 1, wherein the stacking distance is sequentially changed from the outer side to the inner side. 5. The bolt and screw according to any one of claims 1 to 4, wherein the elastic body is rubber. 6. The bolt and the screw according to claim 1, wherein the elastic body is synthetic resin. 7. A bolt and a screw according to claim 1, wherein the cushioning portion is covered with a covering material.