JP2003130021A - Expandable anchor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expandable anchor and its manufacturing method capable of lessening knocking resistance of an inserting member and enhancing tensile strength. SOLUTION: An anchor body 101 having a tapered-off through-hole 111 extended to an axial direction provides a slit 113 at a pointed head portion 112 of the anchor body 101. A knocking pin 102 is inserted into through-hole 111. A shape of a pointed head face of the anchor body 101 is a pseudo-polygon made of a plurality of arcs. The pointed head portion 112 is expanded so that the knocking pin 102 is inserted through the through-hole 111, and one circle is formed by the contours of the pointed head surface of the anchor body 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion anchor and a method for manufacturing the expansion anchor.

[0002]

2. Description of the Related Art Conventionally, as an expansion anchor, FIG.
As shown in 0, a tubular anchor main body 501 and a driving pin 502 to be inserted into a pin hole 511 of the anchor main body 501 are provided, and the tip end portion 51 of the anchor main body 501 is provided.
There is one in which a slit 513 is provided in No. 2 so that the tip portion 512 can be expanded (see Japanese Patent Laid-Open No. 63-165037). The slit 513 extends axially from the tip surface of the anchor body 501 and reaches the bottom portion 511a of the pin hole 511. That is, the pin hole 511 and the slit 5
It is in communication with 13.

FIG. 11 shows a schematic view of the tip surface of the anchor body 501.

The tip portion 512 of the anchor body 501.
Is divided into four divided pieces 512 a, 5 by the slit 513.
12b, ... Further, the contour of the tip surface of the anchor body 501 forms one circle.

[0005]

In the conventional expansion anchor described above, when the driving pin 502 is inserted into the through hole 511, the tip end of the driving pin 502 is divided into the divided pieces 512a, 51.
2b, ... Abuts on the center side corner. Therefore, when the driving pin 502 is driven and the driving pin 502 enters the slit 513, the driving pin 502 is divided into the divided pieces 5.
.. will proceed in the axial direction while crushing the corners of 12a, 512b, ... Therefore, the driving pin 50
There is a problem that the implantation resistance of 2 is large.

The tip portion 5 of the anchor body 501 is also provided.
12 is inserted into the hole 11 of the wall 10, for example, as shown in FIG. After that, by driving the driving pin 502, the driving pin 502 is inserted into the slit 513 and the tip portion 512 of the anchor body 501 is expanded.
At this time, the tip portion 512 and the hole 11 have points A, B,
Since the contact is made only at four points C and D, there is a problem that the tensile strength of the anchor body 501 is small.

SUMMARY OF THE INVENTION An object of the present invention is to provide an expansion anchor and a method of manufacturing the expansion anchor which can reduce the driving resistance of the insertion member and increase the tensile strength.

[0008]

In order to achieve the above object, the expansion anchor of the invention according to claim 1 is a tubular anchor body having a slit formed at the tip and having a tapered through hole extending in the axial direction. And an insertion member to be inserted into the through hole, and the shape of the front end surface of the anchor body is a pseudo-polygonal shape composed of a plurality of arcs, and the insertion member is inserted into the through hole to provide the distal end. The portion is widened, and the contour of the front end surface forms one circle.

According to the expanding anchor of the first aspect of the present invention, for example, when fixing the anchor body to the wall, after inserting the tip of the anchor body into the hole of the wall, the insertion member is inserted into the through hole. , Expand the tip of the anchor body. At this time, since the insertion member is guided by the tapered through hole, the insertion member is smoothly guided to the tip surface of the anchor body. Therefore, it is possible to reduce the driving resistance of the insertion member when the insertion member is driven.

When the tip portion of the anchor body is expanded, the contour of the tip surface of the anchor body forms one circle, so that the contact area between the tip portion and the hole in the wall increases, and the anchor body The tensile strength can be increased. That is, the anchor body can be more firmly fixed to the wall.

According to a second aspect of the present invention, in the method of manufacturing the expansion anchor, the first step of forming a tubular member whose one end portion is in a divergent shape, and the slit is formed at one end portion of the tubular member. And a second step of performing a drawing process on one end of the tubular member to reduce the diameter of one end of the tubular member and to form one end surface of the tubular member with a plurality of arcs. And a third step of forming a pseudo-polygon.

The expansion anchor according to the first aspect can be easily manufactured by the method for manufacturing the expansion anchor according to the second aspect.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The expansion anchor of the present invention and the method for manufacturing the same will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 (a) is a schematic front view of an expansion anchor according to an embodiment of the present invention, and FIG. 1 (b) is a schematic vertical sectional view of the expansion anchor.

The expansion anchor is a tubular anchor body 101 having a tapered through hole 111 extending in the axial direction.
And a driving pin 102 as an example of an insertion member that is inserted into the through hole 111 of the anchor body 101. The tip of the driving pin 102 is rounded. That is, the tip of the driving pin 102 is not sharp.

A slit 113 is formed in the tip portion 112 of the anchor body 101, and the tip portion 112 is formed.
Can be expanded. The width of the slit 113 gradually narrows toward the tip, and the tip end of the slit 113 is closed without being opened. In addition, the tip 112
Then, the diameter of the through hole 111 is gradually reduced toward the tip side. That is, in the tip portion 112, the side surface of the through hole 111 is a tapered surface. Then, a screw portion 114 with which a nut (not shown) is screwed is provided on the outer peripheral surface of the rear end portion (the end portion on the opposite side of the tip portion 112) of the anchor body 101.

Further, as shown in FIG. 3, the tip portion 112 of the anchor body 101 has four divided pieces 112a and 11a.
2b, ... And the shape of the tip surface of the anchor body 101 is a pseudo quadrilateral consisting of four arcs.

According to the expansion anchor having the above structure, when the anchor body 101 is fixed to a wall, for example, the tip 112 of the anchor body 101 is first inserted into the hole provided in the wall. After that, the driving pin 102 is driven, and as shown in FIG.
As shown in, the driving pin 102 is moved from the position indicated by the chain double-dashed line to the position indicated by the solid line. At this time, since the side surface on the tip side of the through hole 111 is a tapered surface, the driving pin 102 is smoothly guided to the side surface on the tip side of the through hole 111. Therefore, the driving resistance of the insertion pin 102 can be reduced. Specifically, the implantation resistance is reduced by about 50% compared to the conventional example of FIG.

Further, with the movement of the driving pin 102, the tip 112 also moves from the position shown by the chain double-dashed line to the position shown by the solid line. In other words, the driving pin 102 is inserted into the through hole 111, so that the anchor body 101
The front end portion 112 of the sheet expands as shown in FIG. At this time, since the front end surface of the anchor body 101 forms one circle, each arc of the divided pieces 112a, 112b, ... Makes contact with the hole in the wall. As a result, the contact region between the tip 112 of the anchor body 101 and the hole in the wall is large, and the tensile strength of the anchor body 101 can be improved.
Specifically, the tensile strength is increased by about 50% as compared with the conventional example of FIG.

Even if the driving pin 102 is driven until the tip 112 is sufficiently widened, the driving pin 102 is
Since the tip of is not sharp, the driving pin 102 does not largely project from the tip surface of the anchor main end 101. Therefore, the tip of the driving pin 102 can be prevented from hitting the bottom surface of the hole in the wall.

The method of manufacturing the expansion anchor will be described below.

First, a tubular member whose one end has a divergent shape is formed.

Next, a slit is formed at one end of the tubular member.

Then, one end of the tubular member is drawn to reduce the diameter of one end of the tubular member, and the shape of the one end face of the tubular member is formed by four arcs. Make a rectangle. By doing so, the expansion anchor can be easily manufactured.

In the above embodiment, nothing is provided on the outer peripheral surface of the driving pin 102, but a blade protruding in the radial direction may be provided on the outer peripheral surface of the driving pin 102. In this case, it is possible to prevent the driving pin from coming off before and after driving the driving pin. Further, even if a knurling is provided on the outer peripheral surface of the driving pin, the driving pin can be prevented from coming off, and even if the tip of the driving pin is bent about 5 ° with respect to the base of the driving pin, the driving pin will come off. Can be stopped.

In the above embodiment, the anchor body 101
The front end 112 of the four divided pieces 112a, 112b, ...
However, as shown in FIG. 5, the distal end portion 212 of the anchor body may be composed of six divided pieces 212a, 212b, .... In this case, the shape of the tip surface of the anchor body is a pseudo hexagon consisting of six arcs. Then, as shown in FIG. 6, the driving of the driving pin 202 causes the distal end portion 112 to expand, and the contour of the distal end surface of the anchor body forms one circle.

In short, the shape of the tip surface of the anchor body is a pseudo-polygonal shape composed of a plurality of arcs, and when the insertion member is inserted through the through hole of the anchor body, the tip portion of the anchor body expands. And the tip surface thereof forms one circle.

FIG. 7 (a) is a schematic vertical sectional view of a main part of a modification of the expanding anchor of the present invention, and FIG. 7 (b) is a schematic front view of the driving rod 300 used for the expanding anchor. It is a figure and Drawing 7 (c) is a schematic front view of bolt 315 used for the above-mentioned expansion anchor.

In the expansion anchor, a slit 313 is formed in the tip end portion 312, and a cylindrical anchor body 301 having a tapered through hole 311 extending in the axial direction, and the anchor body 301 is inserted into the through hole 311. And a cylindrical cone 302 as an example of an insertion member.
The peripheral edge of the tip surface of the cone 302 is rounded so that the tip of the cone 302 is not sharp.

A slit 313 is formed in the tip portion 312 of the anchor body 301 so that the tip portion 312 can be expanded. The width of the slit 313 gradually narrows toward the tip, and the tip end of the slit 313 is not open but closed. In addition, the tip 3
12, the diameter of the through hole 311 is gradually reduced toward the tip side. That is, in the tip portion 312,
The side surface of the through hole 311 is a tapered surface. Further, on the upper side in the figure from the tip portion 312, a threaded portion 314 with which a bolt 315 is screwed is provided on the side surface of the through hole 311. No screw portion is provided on the outer peripheral surface of the anchor body 301.

Although not shown, the anchor body 3 is also provided.
The tip portion 312 of 01 is composed of four divided pieces,
The shape of the front end surface of the anchor body 301 is a pseudo quadrilateral consisting of four arcs.

According to the expansion anchor having the above structure, when the cone 302 is driven by the driving rod 300, the cone 302 moves from the position shown by the chain double-dashed line to the position shown by the solid line, as shown in FIG. Accordingly, the anchor body 30
The tip end portion 312 of No. 1 also moves from the position indicated by the chain double-dashed line to the position indicated by the solid line, and the tip end portion 312 of the anchor body 301 expands, and the same effect as the expansion anchor of FIG. 1 is achieved.

In the expansion anchor of FIG. 7A, the cone 30 is used.
However, as shown in FIG. 9A, a threaded rod 402 may be used as an example of the insertion member. In this case, the cone 302 and the bolt 315 are connected to the screw rod 402.
Since it is substituted by, the number of parts can be reduced.

The head portion 30 of the anchor body 301 is also
1a may be a hexagonal head, or, as shown in FIG. 9B, the head 401a of the anchor body 401 may be a countersunk head. Alternatively, the head of the anchor body may be a truss head. In short, the shape of the head of the anchor body is not particularly limited, and the shape of the head of the screw rod 402 is not particularly limited. For example, the head of the screw rod 402 may be a pan head or a countersunk head.

[0035]

As is apparent from the above, in the expanding anchor of the invention of claim 1, since the through hole is tapered by penetrating the tubular anchor body, the insertion member is anchored by the through hole. The insertion member can be smoothly guided to the front end surface of the main body, and the driving resistance of the insertion member when driving the insertion member can be reduced.

When the tip portion of the anchor body is expanded, the contour of the tip surface of the anchor body forms one circle, so that the contact area between the tip portion and the hole in the wall increases,
The tensile strength of the anchor body can be increased. That is,
The anchor body can be more firmly fixed to the wall.

According to the method of manufacturing the expansion anchor of the second aspect, the expansion anchor of the first aspect can be easily manufactured.

[Brief description of drawings]

FIG. 1 (a) is a schematic front view of an expansion anchor according to an embodiment of the present invention, and FIG. 1 (b) is a schematic vertical sectional view of the expansion anchor.

FIG. 2 is a schematic vertical sectional view of a main part of the expansion anchor.

FIG. 3 is a schematic view of a front end surface of an anchor main body in the expansion anchor.

FIG. 4 is a schematic view of a tip surface of the anchor body.

FIG. 5 is a schematic view of a front end surface of an anchor body in a modified example of the expansion anchor of the present invention.

FIG. 6 is a schematic view of the tip surface of the anchor body.

FIG. 7 (a) is a schematic vertical sectional view of a main part of a modified example of the expansion anchor of the present invention, and FIG. 7 (b) is a schematic front view of a driving rod used for the expansion anchor. It is a figure and Drawing 7 (c) is a schematic front view of the bolt used for the above-mentioned expansion anchor.

FIG. 8 is a schematic vertical sectional view of a main part of the expansion anchor.

9 (a) and 9 (b) are schematic front views showing a part of a modification of the expansion anchor of the present invention in section.

FIG. 10 is a schematic front view showing a part of a conventional expansion anchor in cross section.

FIG. 11 is a schematic view of a front end surface of an anchor body in the above-described conventional expansion anchor.

FIG. 12 is a schematic view of the tip surface of the anchor body.

[Explanation of symbols]

101,201,301,401 Anchor body 112,212,312 Tip 102,202 drive pin 302 corn 402 screw rod

Claims (2)

[Claims] 1. A tubular anchor body having a slit formed in the tip end portion and having a tapered through hole extending in the axial direction, and an insertion member inserted into the through hole, the tip end surface of the anchor body being provided. The shape is a quasi-polygonal shape composed of a plurality of arcs, and the insertion member is inserted through the through hole, whereby the tip end portion is expanded and the contour of the tip end surface forms one circle. Expansion anchor to be. 2. A first step of forming a tubular member whose one end has a divergent shape, a second step of forming a slit in one end of the tubular member, and one of the tubular members. And a third step of reducing the diameter of one end of the tubular member to make the contour of the one end face of the tubular member into a pseudo-polygon consisting of a plurality of arcs. A method for manufacturing an expansion anchor, comprising: