JP2004332446A - Anchor hole diameter enlarging device and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easy-to-operate high quality anchor hole diameter enlarging device for allowing the diameter enlargement of an anchor hole without depending on the skill of a worker, and its method. <P>SOLUTION: The diameter enlarging device 1 comprises a core shaft 2 formed with its cross section area divergent along the axis of the anchor hole, a width enlarger 3 slidably provided along side faces 211, 221 of the core shaft, a cutter 4 provided on the width enlarger 3, and a thrust transmitter 6 as a member for transmitting thrust to the width enlarger 3, hinge joined to one end of the width enlarger 3 at the side of an anchor insertion port 81. Diameter enlargement is accomplished by applying the thrust to the core shaft 2 and the thrust transmitter 6 to cause the width enlargement of the width enlarger 3 while transmitting rotating force to the core shaft 2, the width enlarger 3 and the thrust transmitter 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a device and a method for expanding an anchor hole used for expanding the area near the bottom of the anchor hole in an anchor hole provided when installing a post-installed anchor on an existing concrete surface or a bedrock. It is.
[0002]
[Prior art]
In a case where a structure is added so as to be adjacent to an existing structure (for example, a concrete structure) or in a case where a structural member of the existing structure (for example, a wall or a column constituting the concrete structure) is thickened and reinforced, the connection portion is used. It is common to install a post-installed anchor in the thickened area. That is, in the above-mentioned connecting portion and the like, in order to integrate the structures to be connected, it is expected that the anchor has shear strength and tensile strength.
By the way, in the construction of the post-installed anchor, an anchor hole is drilled in the existing structure surface, the inside of the anchor hole is cleaned, and then the anchor is inserted and the anchor is fixed in the hole. Here, a cement-based or resin-based filler is generally used for anchoring. Also, there are various methods for filling such a filler, such as a method of filling the anchor after insertion into the hole, a method of setting a resin-based material contained in the capsule in the hole in advance, and driving the anchor into the hole. .
The drilling length and drilling diameter of the post-installed anchor are determined by the design pull-out force and design shear force. In other words, it has a tensile strength greater than the designed pull-out force (the smallest of the tensile strength of the anchor base material, the frictional resistance between the anchor and the filler, and the adhesion resistance between the existing structure and the filler). Thus, it is necessary to increase the drilling length or increase the drilling diameter so as to provide a shear strength greater than the design shearing force.
[0003]
Meanwhile, as a method of improving the anchor strength of a post-installed anchor, there is a method of increasing the diameter near the bottom of the anchor hole as shown in Patent Document 1. When drilling an anchor hole of the same diameter and installing a post-installed anchor, if the drilling length is increased to secure the tensile strength, the cone destruction range that can interfere with the reinforcing steel constituting the existing structure or can be caused by the tensile force The problem of widening is caused. In order to solve such a problem, the peripheral area of the anchor hole is increased by increasing the diameter in the vicinity of the bottom of the anchor hole, and the required anchor strength can be obtained with a relatively short drilling length.
For example, as shown in FIG. 8, while using a taper portion d provided on a lower surface of a stopper c of the drill b, the drill b is given a rotary motion and a precession motion (a motion in which the direction of the rotation axis of the rotating body changes). The diameter near the bottom of the anchor hole a can be enlarged.
[0004]
[Patent Document 1]
JP-A-2003-62827
[Problems to be solved by the invention]
The above-described conventional anchor hole construction device (diameter expanding device) and its construction method (diameter expansion method) have the following problems.
<B> In the method of creating a required enlarged hole near the bottom of the anchor hole, it is necessary to manually precess the drill to be used, and the quality of the created anchor hole depends on the skill of the worker. Easy to do.
<B> In the method of forming an anchor hole having the same diameter, it is necessary to increase a drilling length in order to obtain a required tensile strength, and it becomes easy to interfere with a reinforcing bar constituting an existing structure. Since the cone breaking area increases as the length increases, a problem tends to occur particularly when anchoring is performed at a corner of a structure.
<C> In the method of forming an anchor hole having the same diameter, the tensile strength of the anchor is extremely reduced due to aging of the filler.
[0006]
[Object of the invention]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide an anchor hole expanding apparatus and a method for expanding the diameter of the anchor hole, which can make the drilling length relatively short. It is another object of the present invention to provide an anchor hole expanding apparatus and a method for expanding the diameter of the anchor hole, which can realize an excellent diameter expansion of the anchor hole without being affected by the skill of the worker.
The present invention achieves at least one of these objects.
[0007]
[Means for Solving the Problems]
In order to achieve the object as described above, the anchor hole diameter expanding device of the present invention is an anchor hole diameter expanding device used when drilling a hole near the bottom of the anchor hole. A core shaft molded so that the cross-sectional area cut vertically extends along the anchor hole axis, a widened body slidably provided along the side surface of the core shaft, and the widened body provided A cutting body, a member for transmitting a pressing force to the widening body, and a pressing force transmitting body connected to one end of the widening body on the side of the anchor insertion port by a hinge connection; and A diameter expanding device for an anchor hole, wherein the widening body is widened by sliding the pressing force transmitting body along the core shaft while transmitting rotational force to the widening body and the pressing force transmitting body. It is.
[0008]
Further, in the above-described anchor hole diameter expanding device, the connecting portion for hinge-connecting one end of the widening body and one end of the pressing force transmitting body to press the widening body via the hinge connection against the core shaft body. The elastic body is provided so as to engage with both the widening body and the pressing force transmitting body.
[0009]
Further, the anchor hole diameter expanding device of the present invention is an anchor hole diameter expanding device used when drilling a hole near the bottom of the anchor hole, wherein the cross-sectional area cut perpendicular to the anchor hole axis is the anchor hole. A mandrel formed so as to be divergent along the axis, a widened body slidably provided along the side surface of the mandrel, a cut body provided on the widened body, and a pressing force applied to the widened body. A pressure transmitting member connected to one end of the widened body on the anchor insertion port side by an elastic connecting member, wherein the core shaft, the widened body, and the pressing force transmitting member are transmitted to the body. An apparatus for expanding the diameter of an anchor hole, characterized in that the pressing force transmitting body is slid along the core shaft body while transmitting rotational force to a body to widen the widening body.
[0010]
Further, in the above-described diameter expanding apparatus for an anchor hole, the core shaft body is connected to an expansion guide formed so that a cross-sectional area cut perpendicular to the anchor hole axis becomes divergent along the anchor hole axis, and is connected to the expansion guide. And a pressing force transmission guide that is slidable along the side surface of the pressing force transmission guide.
[0011]
Further, in the above-described device for expanding the diameter of the anchor hole, the widening body includes a contact portion that comes into contact with the side surface of the mandrel, and a hook portion that hooks the widening body on the mandrel. An anchor hole expanding device characterized by the following characteristics can be used.
[0012]
In addition, the method of expanding the diameter of the anchor hole using the expanding device of the anchor hole described above includes drilling the anchor hole, inserting the expanding device of the anchor hole into the anchor hole, and forming the core shaft body. While transmitting a rotational force to the widening body and the pressing force transmitting body, a pressing force is applied to the pressing force transmitting body to widen the widening body, thereby performing a diameter expansion near the bottom of the anchor hole. This is a method for expanding the diameter of the anchor hole.
[0013]
Embodiment 1 of the present invention
Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.
[0014]
<A> Diameter expansion device (Fig. 1 and Fig. 2)
The diameter expanding device 1 of the present invention used when drilling a hole near the bottom of the anchor hole 8 includes the core shaft 2 and the cutting body 4 that slides along the side surface 211 of the core shaft 2. It comprises a widened body 3 and a pressing force transmitting body 6 connected via a connecting portion 5 hingedly connected to the widened body 3.
The core shaft body 2 described later is formed so that the cross-sectional area cut perpendicular to the axis of the anchor hole 8 toward the bottom of the anchor hole 8 becomes divergent. A pressing force transmitting body 6 described later slides along the side surface 221 of the core shaft body 2. The pressing force transmitting body 6 is a component member of the diameter expanding device 1 provided to transmit the pushing force to the widening body 3 described later and to expand the widening body 3 to the side according to the cross-sectional shape of the core shaft body 2. . A cutting body 4 for performing diameter-increasing cutting is provided on a side surface (on the wall side of the anchor hole 8) of the widening body 3 connected to one end of the pressing force transmitting body 6 via a connecting portion 5 hingedly connected.
After pre-drilling the anchor hole 8 having substantially the same diameter, the diameter expanding device 1 is inserted into the anchor hole 8, and a known rotation driving device ( A core-drill or the like is attached to apply a rotational force (and a pressing force) to the widening device 1. By applying a pressing force to the pressing force transmitting body 6 of the widening device 1 during the rotation operation, the pressing force transmitting body 6 slides on the side surface 221 of the core shaft body 2, and the widening body 3 is By expanding in the direction, the rotation trajectory of the widened body 3 (cutting body 4) having a diameter larger than the diameter of the anchor hole 8 described above is formed, and a large diameter drilling hole can be realized.
Since the diameter expanding device 1 has a very simple structure as described above, the manufacturing cost can be reduced. Further, since the desired diameter-enlargement anchor hole 8 can be formed by a very simple operation of merely applying a pressing force to the diameter-expansion device 1 during the rotation operation, the quality is secured without being affected by the skill of the worker. The diameter of the anchor hole 8 can be increased.
[0015]
<B> Core Shaft The core shaft 2 is a component of the diameter expanding device 1 for sliding the pressing force transmitting member 6 and the widening member 3 on the side surfaces 211 and 221 and rotating the entire diameter expanding device 1. It is.
The core shaft body 2 of the present invention is formed so that a cross-sectional area cut perpendicular to the axis of the anchor hole 8 becomes divergent along the axis of the anchor hole 8. By performing such molding, the widened body 3 can be expanded to the side surface along the side surface 211 of the core shaft 2.
It is preferable that the above-mentioned cross-sectional shape of the mandrel 2 is formed into a square or a rectangle. This is for ensuring stable sliding of the widening body 3 described later. In other words, the widened body 3 is formed on the surface of the side surface 211 by forming the widened body 3 into a contact portion 31 that contacts the side surface 211 of the mandrel 2 and a hook portion 32 for hooking the widened body 3 on the mandrel 2. The widened body 3 can be slid while the hook 32 is hooked on the upper surface 213 and the lower surface 214 of the core shaft 2.
Even when the cross-sectional shape of the mandrel 2 is formed into a square or a rectangle, the corners 212 and 222 of the cross-section are cut and formed from the upper surface 213 (or the lower surface 214) to the side surfaces 211 and 221 at a predetermined angle. The cross-sectional shape of the body 2 can be a polygon (see FIG. 2). By performing such molding, the widened body 3 easily slides on the side surface 211 of the core shaft 2.
[0016]
As shown in FIG. 2, an expansion guide 21 formed so that a cross-sectional area cut perpendicular to the axis of the anchor hole 8 becomes divergent along the axis of the anchor hole 8, and a cross-sectional area connected to the expansion guide 21 is The mandrel 2 can also be manufactured so as to consist of a substantially constant pressing force transmission guide 22 along the axis of the anchor hole 8. At the stage before the widening body 3 opens to the side, the pressing force transmitting body 6 and the widening body 3 are in a state of being arranged on the side surface 221 of the pressing force transmitting guide 22. By applying a pressing force to the pressing force transmitting body 6, the pressing force transmitting body 6 and the widening body 3 slide on the side surface 221, and the widening body 3 moves on the side surface 211 of the expansion guide 21, so that the widening body 3 is moved. The extension guide 21 can be opened to the side via the connecting portion 5 according to the cross-sectional shape of the extension guide 21.
[0017]
The core shaft 2 can be formed into a solid rod as shown in FIG. 3 (a), or a shape having a cavity 24 inside the rod as shown in FIG. 3 (b). You can also. Further, as shown in FIG. 3C, the notch 25 can be provided on each of the upper surface 213, the lower surface 214, and the side surfaces 211 and 221, and a hollow can be formed inside the mandrel 2. Of course, the present invention is not limited to this embodiment.
Also, by forming the core shaft 2 as shown in FIG. 3 (c) and providing the notch 25, the core shaft 2 can serve as a discharge part for dust generated when drilling the anchor hole 8 and a ladle generated during washing. Can also play a role.
[0018]
It is preferable to provide, for example, a conical projection 23 at the tip of the core shaft 2 on the bottom side of the anchor hole 8 (see FIG. 1). This is because after inserting the diameter expanding device 1 into the anchor hole 8, the projection 23 is inserted into the bottom of the hole to fix the diameter expanding device 1 in the hole.
Note that the projection 23 can be formed into a pyramid shape instead of a conical shape.
[0019]
<C> The widened body and the pressing force transmitting body The widened body 3 slides on the contact portion 31 sliding on the side surface 211 of the mandrel 2 and on the corner portion 212 and the upper surface 213 and the lower surface 214 of the mandrel 3. And the hook portion 32 to be connected. By providing such a hook portion 32, the widened body 3 can be slid along the side surface 211 of the core shaft 2 in a state where the widened body 3 is hooked on the core shaft 2. Stable sliding of the widened body 3 can be realized without causing a problem that the body 3 comes off during sliding. In addition, since the widened body 3 is pressed against the core shaft body 2 by the elastic body 7 described later, the stable sliding of the widened body 3 can be secured.
[0020]
At the end of the contact surface 31 of the widening body 3 on the side of the anchor insertion opening 81, the rod insertion portion 33 can be protruded at two (or three or more) intervals in parallel with the side surface 31. .
On the other hand, at the end of the side surface 61 of the pressing force transmitting body 6 on the side of the connection with the widened body 3, a bar insertion portion 62 is provided so as to protrude in one place (or two or more places) in parallel with the side surface 61. it can. Here, the rod insertion part 62 is arranged so that the rod insertion part 62 can be fitted in the space between the rod insertion parts 33 provided at two places when the widening body 3 and the pressing force transmitting body 6 are connected. I do.
After the rod insertion part 62 is fitted in the space between the rod insertion parts 33, the connecting part 5 that inserts the rod 51 into the rod insertion part 33 and the rod insertion part 62 and hinge-joins it is configured. That is, the rod insertion portions 33 and 62 are manufactured in a shape having a hollow cross-sectional area equal to or larger than the cross-sectional area of the rod 51 in the rod 51 insertion direction in which the rod 51 can be inserted. The rod 51 has a circular cross section perpendicular to the rod axis direction and is rotatable.
[0021]
The cutting body 4 is provided on the outer surface of the contact surface 31 of the widening body 3. Here, it is preferable that the cross-sectional shape of the cutting body 4 cut perpendicularly to the axis of the anchor hole 8 is formed into a shape in which the widened circular section can be easily formed by rotating the widening body 3. For example, as shown in the embodiment of FIG. 2, the cutting body 4 can be manufactured as a cutting body 4 having a cross-sectional shape having a predetermined curvature while being installed so that the outer surface of the hook 32 of the widening body 3 and the outer surface of the cutting body 4 are continuous. . Further, in order to enable cutting of a concrete body or the like, the surface of the cutting body 4 can be manufactured with an industrial diamond chip. The cutting body 4 can be provided, for example, at two places at the end of the side surface of the widening body 3 (see FIG. 2).
[0022]
<D> Elastic body (FIGS. 4A and 4B)
In order to press the widened body 3 via the connecting portion 5 against the core shaft 2, an elastic body 7 is provided on the surface of the widened body 3 and the surface of the pressing force transmitting body 6 so as to straddle the widened body 3 and the pressing force transmitting body 6. It can be provided (see FIG. 4A). By providing the elastic body 7, the widened body 3 is pressed against the side surface 221 of the pressing force transmission guide 22 and the side surface 211 of the expanded guide 21 before and after the widening, and the widened body 3 is flexible due to the flexibility of the elastic body 7. If it opens outside, you can follow it.
The elastic body 7 can be made of, for example, a steel leaf spring 71, a plastic leaf spring 71, or a rubber plate material.
In addition, for example, a helically continuous spring 72 is installed in the hollow space between the rod insertion part 33 and the rod insertion part 62 constituting the connecting part 5, and the rod 51 is inserted into the spring 72. The connecting portion 5 can also be configured (see FIG. 4B).
[0023]
Embodiment 2 of the present invention
In addition to manufacturing the diameter expanding device 1 using two widening bodies 3 as described above, it is also possible to manufacture the diameter expanding device 1 using one widening body 3 (see FIG. 5). Since the diameter expanding device 1 expands the diameter of the anchor hole 8 by rotating, it is possible to form the anchor hole 8 of the same degree as the case of two even if there is one wide body 3. However, as compared with the case where the number of the widening bodies 3 is two, the durability is reduced, so that the frequency of overhaul and the like cannot be denied.
[0024]
Third Embodiment of the Invention
This is an embodiment in which one end of the widening body 3 on the anchor insertion port 81 side and an end of the pressing force transmitting body 6 are connected by an elastic connecting member 9 to manufacture the diameter expanding device 1 (see FIG. 6). That is, the connecting portion 5 of the present embodiment does not connect the widening member 3 and the pressing force transmitting member 6 via a hinge connection, but connects the connecting portion 5 via an elastic connecting member 9 formed of, for example, a steel elastic member. It constitutes.
Although FIG. 6 shows an example in which two widening bodies 3 are provided, the diameter expanding device 1 can be manufactured using one widening body 3 as in the second embodiment.
[0025]
【Example】
Hereinafter, an embodiment of the anchor hole diameter expanding method of the present invention will be described with reference to the drawings.
[0026]
First, an anchor hole 8 having substantially the same diameter is formed by a known core drill (see FIG. 7A). After drilling, the inside of the hole is washed with pressured air or pressured water to remove drill holes.
Next, the diameter expanding device 1 is inserted into the anchor hole 8. The projection 23 provided at the tip of the core shaft body 2 is pierced into the bottom of the anchor hole 8 to fix the diameter expanding device 1 in the hole (see FIG. 7B).
The core-drill device is attached to the diameter-enlarging device 1 (the core shaft body 2 and the pressing force transmitting body 6), and the rotation drive of the core-drill device is transmitted to the diameter-expanding device 1 and the core-drill device is pushed into the pressing force transmitting member. The widening body 3 is released to the outside while applying a pressing force to 6 to complete the diameter expansion near the bottom of the anchor hole 8 (see FIG. 7C).
After the completion of the diameter expansion, the inside of the anchor hole 8 is washed again to prepare for the insertion of the anchor (and the filling of the filler).
【The invention's effect】
The apparatus for expanding the diameter of the anchor hole and the method for expanding the diameter of the anchor hole according to the present invention are as described above, and the following effects can be obtained.
<a> The operation is simple, and the diameter of the anchor hole can be expanded with good quality without being affected by the skill of the worker.
<B> Since the structure is relatively simple, the cost required for manufacturing the device can be low.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a diameter expanding device of the present invention.
FIG. 2 is an exploded perspective view of the diameter expanding device of the present invention.
FIG. 3 is a perspective view showing an example of the core shaft, and FIG. 3A is a perspective view showing the core shaft when molded as a solid rod. (B) A perspective view showing a core shaft body when molded as a rod-like body having a cavity. (C) A perspective view showing the mandrel in the case where the cavity and the mandrel are formed with notches on the surface.
FIG. 4 is an enlarged perspective view showing a connecting portion, and (a) is a perspective view showing the connecting portion when a leaf spring is used as an elastic body. (B) A perspective view showing a connecting portion formed by installing a helical spring used as an elastic body in a rod insertion portion.
FIG. 5 is a perspective view showing another embodiment of the diameter expanding device of the present invention.
FIG. 6 is a perspective view showing another embodiment of the diameter expanding device of the present invention.
FIGS. 7A and 7B are construction diagrams of a method of expanding the diameter of the anchor hole, and FIG. (B) The situation figure which inserted the diameter expansion apparatus in the anchor hole. (C) The situation figure which expands the diameter near the bottom part of an anchor hole.
FIG. 8 is a diagram showing a conventional expansion state of an anchor hole.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Diameter expansion device 2 ... Core shaft 21 ... Expansion guide 22 ... Pressing force transmission guide 211 / Side 221 / Side 3 ... Widened body 31 ... Contact part 32 ... Hook part 4 ... ..Cutting body 5 ... Connecting part 6 ... Pressing force transmitting body 7 ... Elastic body 8 ... Anchor hole 81 ... Anchor insertion port 9 ... Elastic connecting member

Claims (6)

An anchor hole diameter expanding device used when drilling a hole near the bottom of the anchor hole,
A core shaft body formed so that the cross-sectional area cut perpendicular to the anchor hole axis becomes divergent along the anchor hole axis,
A widening body slidably provided along the side surface of the core shaft body,
A cutting body provided in the widening body,
A member for transmitting a pressing force to the widening body, comprising a pressing force transmitting body connected to one end of the widening body on the anchor insertion port side by a hinge connection,
While transmitting rotational force to the core shaft, the widening body, and the pressing force transmitting body, the pressing force transmitting body is slid along the core shaft to widen the widening body, Anchor hole expansion device. An elastic body for pressing one end of the widening body and one end of the pressing force transmitting body hingedly to press the widening body through the hinge connection against the core shaft body; Characterized in that it is provided to engage with both of the pressing force transmitting bodies,
The diameter expanding device for an anchor hole according to claim 1. An anchor hole diameter expanding device used when drilling a hole near the bottom of the anchor hole,
A core shaft body formed so that the cross-sectional area cut perpendicular to the anchor hole axis becomes divergent along the anchor hole axis,
A widening body slidably provided along the side surface of the core shaft body,
A cutting body provided in the widening body,
A member for transmitting the pressing force to the widening body, comprising a pressing force transmitting body connected to one end of the widening body on the anchor insertion port side by an elastic connecting member,
While transmitting rotational force to the core shaft, the widening body, and the pressing force transmitting body, the pressing force transmitting body is slid along the core shaft to widen the widening body, Anchor hole expansion device. An anchor hole expanding device according to any one of claims 1 to 3,
The core shaft body, an expansion guide formed so that the cross-sectional area cut perpendicular to the anchor hole axis is divergent along the anchor hole axis, and a pressing force transmission guide connected to the expansion guide,
An apparatus for expanding the diameter of an anchor hole, wherein the pressing force transmitting body is slidably provided along a side surface of the pressing force transmitting guide. An anchor hole expanding device according to any one of claims 1 to 4,
The wide body includes a contact portion that contacts the side surface of the mandrel, and a hook portion that hooks the wide body on the mandrel.
Anchor hole expansion device. An anchor hole expanding method using the anchor hole expanding device according to any one of claims 1 to 5,
Drilling the anchor hole,
Insert the diameter expansion device of the anchor hole into the anchor hole,
Applying a pressing force to the pressing force transmitting body while transmitting a rotational force to the core shaft body, the widening body, and the pressing force transmitting body, widens the widening body, and expands the diameter near the bottom of the anchor hole. A method for expanding the diameter of an anchor hole, characterized in that:

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