JP2023070857A - Tapping screw, fastening method using the tapping screw and fastening structure - Google Patents

Abstract

To provide a tapping screw which can obtain a necessary axial force even in refastening, and can simplify a work process, a fastening method using the tapping screw, and a fastening structure.SOLUTION: A tapping screw of the present invention comprises a circular ring-shaped spacer. The circular ring-shaped spacer has a plurality of notches and a plurality of spacer parts which are partitioned by the notches. In the spacer parts, since heights of the spacer parts at both sides with the notches sandwiched therebetween while being inclined are set different from each other, higher portions of the spacer parts are pushed down by screwing the tapping screw therein, and divided into a plurality of spacer pieces by the fracture of the notches, the circular ring-shaped spacers come off at refastening, and the tapping screw can be thereby further screwed into a deep position, thus obtaining a necessary axial force by using the same tapping screw.SELECTED DRAWING: Figure 3

Description

The present invention relates to a tapping screw, a fastening method and a fastening structure using the tapping screw, and more particularly, to a refastenable tapping screw, a fastening method and fastening structure using the tapping screw.

A tapping screw is a screw that can be screwed into a base material while tapping it by itself, even if it does not have a female thread.

However, tapping screws are screwed in while tapping, so if they are re-tightened, the thread that was set in advance will be cut, and there is a risk that the axial force cannot be secured. waste it.

In Patent Document 1, multiple types of tapping screws with different lengths are used. First, a short tapping screw is used for fastening, and when refastening is required, a long tapping screw is used to prevent refastening. It is disclosed that a high fastening force can be obtained.

JP 2017-219158 A

However, in the method described in Patent Document 1, it is necessary to prepare a plurality of types of tapping screws, which complicates the work process and may result in the wrong tapping screws being used.

The present invention has been made in view of such problems of the prior art, and aims to provide a self-tapping screw capable of obtaining the necessary axial force even when re-fastened and simplifying the work process. An object of the present invention is to provide a fastening method and fastening structure using the tapping screw.

As a result of earnest studies to achieve the above object, the inventors found that the above object can be achieved by providing a tapping screw with a spacer that breaks at a predetermined torque, and completed the present invention.

That is, the tapping screw of the present invention comprises an annular spacer.
The annular spacer has a plurality of cutouts and a plurality of spacers separated by the cutouts, and the spacers are tilted on both sides of the cutouts. are of different heights.

A fastening method of the present invention is a method of fastening a member to be fastened to a base material using the tapping screw.
Then, the tapping screw is inserted through the member to be fastened and screwed into the base material, and the annular spacer is sandwiched between the bearing surface of the tapping screw and the member to be fastened, and the spacers are broken and arranged in a row in an annular shape. It is characterized by forming a plurality of spacer pieces.

Further, the fastening structure of the present invention is a fastening structure in which a tapping screw is inserted through a member to be fastened and screwed into a base material to fasten the member to be fastened and the base material.
A plurality of spacer pieces arranged annularly in a row between the bearing surface of the tapping screw and the member to be fastened is provided.

According to the present invention, since the tapping screw is provided with a spacer that breaks at a predetermined torque, it is possible to refasten the tapping screw with the same tapping screw without changing the tapping screw, thereby simplifying the work process. A fastening method and fastening structure using screws can be provided.

It is a figure which shows an example of the annular spacer of this invention. It is a figure explaining the state before completely tightening the tapping screw of this invention. It is a figure explaining the first tightening state which completely tightened the tapping screw of the present invention. FIG. 10 is a diagram illustrating a state in which the tapping screw of the present invention is tightened and then loosened; It is a figure explaining the state which refastened the tapping screw of this invention.

<Tapping screw>
The tapping screw of the present invention will be described in detail.
The tapping screw of the present invention comprises an annular spacer, and as shown in FIG. are inclined and the heights of the spacer portions on both sides of the cutout portion are different.

When such a tapping screw is tightened, the annular spacer is sandwiched between the bearing surface of the tapping screw and the member to be fastened, as shown in FIG. When the tapping screw is further screwed in, as shown in FIG. 3, the high portion of the spacer portion is pushed down, so that it is broken at the notch portion and divided into a plurality of spacer pieces.

Therefore, once fastened, the tapping screw of the present invention is divided into a plurality of spacer pieces by breaking the ring-shaped spacer as shown in FIG. .

In addition, when the tapping screw is loosened, the split spacer pieces fall off the tapping screw as shown in FIG.

Therefore, when refastening, the annular spacer will not come off and be reused, and as shown in FIG. Even a tapping screw with a small diameter can obtain the necessary axial force, and there is no need to prepare a different tapping screw for refastening.

The thickness of the spacer portion is preferably 5 to 10 mm, depending on the axial force required for refastening.

The annular spacer preferably has a height difference of 0.5 to 1.0 mm between the spacer portions on both sides of the cutout portion, depending on the size thereof. When the height difference of the spacer portion is within the above range, the cutout portion can be broken.

If the difference in height is too small, the spacer may not be pushed down enough to break the annular spacer. It comes to resist the screwing of the screw, and the workability deteriorates.

In addition, if the thickness of the spacer portion is constant, the fractured spacer piece is sandwiched between the tapping screw and the member to be fastened and comes into contact with the surfaces of the spacer piece and the bearing surface of the tapping screw. The spacer piece does not come off due to the frictional force acting between it and the member.
Therefore, the required axial force can be exerted to maintain the fastened state.

Furthermore, as shown in FIG. 1, the high and low spacer portions are alternately formed so that the high and low portions of each spacer contact the bearing surfaces of the tapping screws, Since each abuts on the member to be fastened, the annular spacer is prevented from being inclined with respect to the bearing surface of the tapping screw and the member to be fastened. Therefore, the tapping screw can be easily screwed straight, improving workability.

The material of the annular spacer is not particularly limited as long as it is broken by the torque when the tapping screw is tightened. Available.

<fastening method>
The fastening method of the present invention is a fastening method of fastening a member to be fastened to a base material using the tapping screw of the present invention.

The tapping screw of the present invention is inserted into the member to be fastened, and the tapping screw is screwed into the base material while the annular spacer is sandwiched between the bearing surface of the tapping screw and the member to be fastened.

Then, the tapping screw is screwed into the base material to narrow the distance between the bearing surface of the tapping screw and the member to be fastened, and the notch portion of the annular spacer is broken to form a plurality of spacer pieces arranged in a row in an annular shape. Thus, the member to be fastened can be fastened to the base material.

According to such a fastening method, it is easy to confirm whether or not the spacer portion is fastened by determining whether or not the spacer portion is divided into a plurality of spacer pieces.

<Fastening structure>
The fastening structure of the present invention is a fastening structure in which a member to be fastened is fastened to a base material using the tapping screw of the present invention. As shown in FIG. screwed together.
The annular spacer of the tapping screw has a cut-out portion, and a plurality of spacer pieces are arranged annularly in a row between the bearing surface of the tapping screw and the member to be fastened.

The base material preferably has pilot holes into which tapping screws are screwed. Having a pilot hole facilitates straight screwing of the tapping screw, improving workability. Since such a pilot hole has a smaller diameter than the nominal diameter of the tapping screw, the tapping screw can be tightly screwed into the hole.

When refastening the tapping screw of the present invention, the tapping screw is screwed to a deeper position than when it was first fastened. Therefore, the tip of the tapping does not reach the bottom of the pilot hole at the time of initial fastening.

The material of the base material is not particularly limited as long as the tapping screw can be screwed while being tapped, but if it is made of resin, tapping is easy. As the resin of the base material, for example, ABS (acrylonitrile-butadiene-styrene) resin, POM (polyacetal) resin, or the like can be used.

REFERENCE SIGNS LIST 1 tapping screw 2 annular spacer 21 notch 22 spacer 3 spacer piece 4 member to be fastened 5 base material 51 pilot hole

Claims (7)

A self-tapping screw comprising a toric spacer,
The annular spacer has a plurality of cutouts and a plurality of spacers divided by the cutouts,
The tapping screw, wherein the spacer portion is inclined and has different heights on both sides of the notch portion. 2. The tapping screw according to claim 1, wherein the height difference between the spacer portions on both sides of the notch portion is 0.5 to 1.0 mm. 3. The tapping screw as set forth in claim 1, wherein said spacer portion has a thickness of 5 to 10 mm. A fastening method for fastening a member to be fastened to a base material using a tapping screw,
The tapping screw is the tapping screw according to any one of claims 1 to 3,
The tapping screw is inserted into the member to be fastened and screwed into the base material, and the annular spacer is sandwiched between the bearing surface of the tapping screw and the member to be fastened, and is broken to form a plurality of annular spacers arranged in a row. A fastening method characterized by forming spacer strips of A fastening structure in which a tapping screw is inserted through a member to be fastened and screwed into a base material to fasten the member to be fastened and the base material,
A fastening structure comprising a plurality of spacer pieces annularly arranged in a row between the bearing surface of the tapping screw and the member to be fastened. The base material has a pilot hole with a smaller diameter than the nominal diameter of the tapping screw,
6. The fastening structure according to claim 5, wherein the tip of the tapping screw screwed into the pilot hole does not reach the bottom of the pilot hole. The fastening structure according to claim 5 or 6, wherein the base material is made of resin.

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