JP2012197840A - Post installing anchor and method for installing and fixing the same to existing concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a post installing anchor capable of obtaining a sufficient strength against an anchor extracting force and a method for installing and fixing the post installing anchor to the existing concrete.SOLUTION: An anchor principal body 1 is cylindrically formed, wherein an extremity of the anchor principal body 1 is provided with an expanding portion 1a with four slits 11 axially formed at given intervals in the circumferential direction on the circumferential wall of the anchor principal body 1 and a basal portion side of the anchor principal body 1 is provided with an externally threaded portion 13 engageable with a nut. An expanding pin 2 is a stick-like pin insertable from the basal portion side into a shaft center hole 12 of the anchor principal body 1. An extremity of the expanding pin 2 is provided with a tapered portion 21 for radially expanding the expanding portion 1a existing in the extremity of the anchor principal body 1 and a basal portion of the expanding pin 2 is provided with a head 22 for driving. In the post installing anchor thus structured, an outer circumference of the anchor principal body 1 is provided with protruding thread ridges 14 which can be screwed into a prepared hole 51 bored in the concrete 5.

Description

  The present invention inserts a cylindrical anchor body portion into a prepared hole drilled in existing concrete after placement, and drives the expansion pin into the axial hole of the anchor body portion, thereby The present invention relates to a post-construction anchor that is fixed by expanding the expanded portion and a technique for improving a post-construction anchor mounting method for existing concrete.

  As a conventional post-installed anchor of this type, for example, as shown in FIG. 10, a male threaded portion 102 to which a nut can be screwed is provided on the proximal end side of a cylindrical anchor main body 101, and a plurality of anchors are provided on the distal end side. The widening portion 104 having the slit 103 is formed, and the widening pin 106 is driven into the axial hole 105 of the anchor main body 101 to expand the diameter of the tip widening portion 104 of the anchor main body 101. Are known (see, for example, Patent Documents 1 and 2).

JP 2005-307637 A Japanese Patent No. 2888553

  However, in the post-construction anchor of the conventional example, as described above, the distal end expanding portion 104 of the anchor main body portion 101 is driven by driving the expansion pin 106 into the axial hole 105 of the cylindrical anchor main body portion 101. However, since the compressive strength of recent concrete has increased significantly compared to before, the tip widened portion of the anchor body 101 is placed on the inner peripheral surface of the pilot hole in the concrete. There was a problem that the strength against pulling out of the anchor was not sufficient because it was not able to bite in and was simply brought into pressure contact.

  The problem to be solved by the present invention is to provide a post-installed anchor that provides sufficient strength for pulling out the anchor and a post-installed anchor mounting and fixing method for existing concrete.

In order to solve the above problems, the invention according to claim 1
The anchor main body portion is composed of an expansion pin, and the anchor main body portion is formed in a cylindrical shape, and a plurality of slits are formed in the axial direction on the peripheral wall of the peripheral wall at predetermined intervals in the circumferential direction. An expansion part is formed, and a base thread side of the anchor main body part has a male screw part capable of screwing a nut, and the expansion pin can be inserted into the axial hole of the anchor main body part from the base side. In the post-construction anchor with a structure that has a tapered portion that expands the distal end widened portion of the anchor main body portion at the distal end portion and a driving head at the proximal end portion,
A screw thread that can be screwed into a pilot hole drilled in concrete is formed on the outer periphery of the anchor main body so as to protrude.

The invention according to claim 2 is the post-constructed anchor according to claim 1, wherein the anchor main body portion is made of a steel material, and at least the screw thread is quenched.

Further, the invention according to claim 3 is the post-construction anchor according to claim 1 or 2,
The thread angle of the thread is 20 ° to 27 °.

The invention according to claim 4
The anchor main body portion is composed of an expansion pin, and the anchor main body portion is formed in a cylindrical shape, and a plurality of slits are formed in the axial direction on the peripheral wall of the peripheral wall at predetermined intervals in the circumferential direction. An expanded portion is formed, and a male screw portion capable of screwing a nut is provided on the base side of the anchor main body portion, and can be screwed into a prepared hole drilled in concrete on the outer periphery of the anchor main body portion. A thread is protrudingly formed, and the expansion pin is a rod-like shape that can be inserted into the axial center hole of the anchor main body portion from the base side, and a tapered portion that expands the diameter of the distal end expansion portion of the anchor main body portion is formed at the distal end portion. It has a structure that has a driven head at the base end, and is a fixing method for fixing the construction anchor,
A step of opening a pilot hole having a diameter larger than the outer diameter of the anchor main body and smaller than the outer diameter of the screw thread in existing concrete;
Screwing the anchor body into the pilot hole by rotating a nut screwed into the male thread of the anchor body with a tool such as a spanner;
The anchor main body portion is formed by driving the expansion pin into the axial hole of the anchor main body portion so that the expansion portion in which the slit of the anchor main body is formed is radially expanded and pressed against the inner peripheral surface of the pilot hole. Fixing the inside of the pilot hole,
It was set as the characteristic characterized by comprising.

Further, the invention according to claim 5 is the method for attaching and fixing the post-construction anchor according to claim 4,
A cap nut is used as a nut screwed into the male thread portion of the anchor main body portion.

In the present invention, as described above, the anchor main body portion and the expansion pin are configured. The anchor main body portion is formed in a cylindrical shape, and a plurality of the main body portions are provided on the peripheral wall of the peripheral wall at predetermined intervals in the circumferential direction. A widened part with slits formed in the axial direction is formed, and a male screw part that can be screwed with a nut is provided on the base side of the anchor main body part, and the widening pin is in the axial center hole of the anchor main body part. In a post-installed anchor having a structure that has a rod shape that can be inserted from the base side, a tapered portion that expands the distal end expanding portion of the anchor body portion at the distal end portion, and a driven head portion at the proximal end portion. The outer periphery of the part has a structure in which a thread that can be screwed into the prepared hole drilled in the concrete is projected, and the anchor body is inserted into the prepared hole formed in the existing concrete. Screwed into the male thread By rotating the nut with a tool such as a spanner, the anchor body portion while forming an internal thread by bite the threads on the inner peripheral portion of the prepared hole can be screwed easily into the prepared hole.
Then, by driving the expansion pin into the axial hole of the anchor main body portion, the expansion portion in which the slit of the anchor main body is formed is expanded in the radial direction, so that the screw thread in the expansion portion is within the pilot hole. The anchor main body can be fixed in the pilot hole by pressing into the peripheral surface and biting deeper.
Thus, by screwing the anchor main body portion into the pilot hole using the screw thread, it can be screwed into the pilot hole with a small force.
In addition, the thread formed on the outer periphery of the anchor body is screwed in while cutting the inner peripheral surface of the pilot hole, and the screw thread in the expanded portion is fixed in a deeper state, so that the anchor can be pulled out. The effect that sufficient strength can be obtained is obtained.
Furthermore, since the anchor body part is screwed while the thread is scraping the inner surface of the pilot hole, after use, the double nut is bitten into the male thread part that fixed the bracket etc., and turned counterclockwise with a tool such as a spanner, The effect that the anchor main body can be easily extracted from the prepared hole is obtained.

  In addition, the anchor body is made of steel and the threads are quenched, so that when the anchor body is screwed into the prepared hole drilled in the concrete, the thread is formed on the inner peripheral surface of the prepared hole. Can be easily screwed in.

  Moreover, by setting the screw angle of the screw thread 14 to 20 ° to 27 °, the anchor body portion can be screwed to a predetermined depth of the pilot hole without deteriorating workability.

  In addition, by using a cap nut as a nut to be screwed into the male thread portion of the anchor main body, the nut can be easily and quickly removed after the anchor main body is screwed into the pilot hole compared to the case of using a normal nut. Will be able to do.

It is a top view which shows the post-construction anchor of this invention Example 1. FIG. It is a front view which shows the post-construction anchor of this invention Example 1. FIG. It is a bottom view which shows the post-construction anchor of this invention Example 1. FIG. It is a rear view which shows the post-construction anchor of this invention Example 1. FIG. It is an expansion left view which shows the construction anchor after the Example 1 of this invention. It is an expansion right view which shows the construction anchor after the Example 1 of this invention. FIG. 3 is a transverse sectional view taken along line S7-S7 in FIG. It is explanatory drawing which shows the attachment process (ii)-(d) with respect to the existing concrete of the post-construction anchor of this invention Example 1. FIG. It is explanatory drawing which shows the attachment process (e)-(h) with respect to the existing concrete of the post-construction anchor of this invention Example 1. FIG. It is sectional drawing which shows the conventional post-construction anchor.

  Embodiments of the present invention will be described below with reference to the drawings.

First, the construction anchor after Example 1 will be described with reference to FIGS.
Thereafter, the construction anchor includes an anchor main body portion 1, an expansion pin 2, and a cap nut 3 that constitutes an anchor main body screwing jig.

The anchor main body portion 1 is formed in a cylindrical shape having an axial hole 12, and at the tip side thereof, an expanded portion in which four slits 11 are formed in the axial direction at predetermined intervals in the circumferential direction. 1a is formed.
As shown in the cross-sectional view of FIG. 7, the axial hole 12 on the distal end side is formed with a tapered portion 12 a that gradually becomes smaller in diameter toward the distal end through a plurality of stepped portions.
Further, a male screw portion 13 capable of screwing a fastening nut is formed on the base side of the anchor main body portion 1.

Further, a right-hand thread 14 protrudes from the outer periphery of the anchor main body 1 on the tip side.
The thread angle of the thread 14 is set to 20 ° to 27 °. The reason for setting the screw angle will be described later.
And the anchor main-body part 1 and the expansion pin 2 are comprised with steel materials, and all have been hardened.

  As shown in FIG. 8, the cap nut 3 constitutes a jig for screwing the anchor main body 1 into the pilot hole, and has an outer shape capable of engaging a tool such as a spanner. A female screw portion 31 that can be screwed into a base end portion of the male screw portion 13 and a top plate portion 32 that comes into contact with the base end surface of the male screw portion 13 are provided.

A process of attaching the construction anchor to the existing concrete after Example 1 will be described with reference to FIGS. 8 (A) to (D) and FIGS. 9 (E) to 9 (H).
(A) First, the prepared hole 51 is drilled in the existing concrete 5 after placement with the concrete drill 6. The inner diameter of the pilot hole 51 is larger than the outer diameter of the anchor main body 1 and smaller than the outer diameter of the thread 14. For example, when the outer diameter of the anchor main body 1 is 20 mm and the outer diameter of the thread 14 is 23 mm, the pilot hole 51 of 21 mm is drilled.
(B) Next, the concrete chips are removed from the inside of the pilot hole 51 with a blower, a dust sucker 7 or the like.
(C) Next, the anchor main body portion 1 is inserted into the prepared hole 51, and the screw nut 14 is lowered by rotating the cap nut 3 screwed into the male screw portion 13 of the anchor main body portion 1 with a tool such as a spanner. The anchor main body 1 is screwed into the pilot hole 51 while forming the female screw 52 by biting into the inner peripheral surface of the hole 51.
(D) The cap nut 3 screwed into the male thread portion 13 of the anchor main body 1 is removed.
(E) The expansion pin 2 is driven into the axial hole 12 of the anchor main body 1 with a hammer or the like to expand the expansion portion 1a in which the slit 11 of the anchor main body 1 is formed in the radial direction. The thread 14 in the portion 1 a presses against the inner peripheral surface of the lower hole 51 and deeply penetrates, whereby the anchor main body 1 is firmly fixed in the lower hole 51.
(F) The bracket 9 and the like are attached and fixed to the male threaded portion 13 of the anchor main body 1 fixed in the pilot hole 51 by the procedure as described above.
(G) After use, the double nut 10 is engaged with the male screw portion 13 to which the bracket 9 or the like is fixed, and the anchor main body portion 1 is extracted from the pilot hole 51 by turning it counterclockwise with a tool such as a spanner.
(H) The mortar M is filled and filled in the prepared hole 51 after the anchor main body 1 is extracted.

  Next, the effect of the first embodiment will be described.

In the present invention, as described above, the anchor main body 1 is formed in a cylindrical shape, and at the tip side thereof, four slits 11 are formed in the axial direction on the peripheral wall at predetermined intervals in the circumferential direction. The opening 1a is formed, and the anchor main body 1 has a male threaded portion 13 that can be screwed with a nut on the base side. The expansion pin 2 is inserted into the axial hole 12 of the anchor main body 1 from the base side. It has a tapered shape that can be inserted, and has a tapered portion 21 that is press-fitted into the distal tapered portion 12a of the axial hole 12 in the anchor main body portion 1 to expand the diameter of the distal expanded portion 1a. In the post-construction anchor having the structure having the driving head 22, a thread 14 that can be screwed into the prepared hole 51 drilled in the concrete 5 is formed on the outer periphery of the anchor main body 1 so as to protrude. , Pilot holes formed in existing concrete 5 1, the anchor main body 1 is inserted, and the cap nut 3 screwed into the male threaded portion 13 of the anchor main body 1 is rotated with a tool such as a spanner, so that the thread 14 is bitten into the inner peripheral portion of the pilot hole 51. Thus, the anchor main body 1 can be easily screwed into the prepared hole 51 while forming the female screw 52.
Then, by driving the expansion pin 2 into the axial hole 12 of the anchor main body 1, the expansion portion 1a in which the slit 11 of the anchor main body 1 is formed is expanded in the radial direction, and the thread in the expansion portion 1a. The anchor main body 1 can be firmly fixed in the lower hole 51 by pressing 14 into the inner peripheral surface of the lower hole 51 and biting deeper.
Thus, by screwing the anchor main body 1 into the pilot hole 51 using the screw thread 14, it can be screwed into the pilot hole 51 with a small force.
Further, the screw thread 14 projecting and formed on the outer periphery of the anchor main body 1 is screwed in while cutting the inner peripheral surface of the pilot hole 51, and the screw thread 14 of the expanded portion 1 a is further deeper into the inner peripheral surface of the pilot hole 51. Since it is fixed in a state where it is bitten, it is possible to obtain an effect that a sufficient strength for pulling out the anchor can be obtained.
Further, since the anchor body portion 1 is screwed while the thread 14 cuts the inner surface of the pilot hole 51, the double nut 10 is engaged with the male screw portion 13 to which a bracket or the like is fixed after use, and the tool is rotated counterclockwise with a tool such as a spanner. By turning to, the anchor body 1 can be easily extracted from the prepared hole 51.

  The anchor main body 1 is made of steel, and at least the screw thread 14 is quenched, so that when the anchor main body 1 is screwed into the pilot hole 51 drilled in the concrete 5, the pilot hole 51. It is possible to easily screw the screw thread 14 into the inner peripheral surface.

Moreover, the following effects are acquired by making the screw angle of the screw thread 14 into 20 degrees-27 degrees.
That is, when the screw angle of the screw thread 14 is less than 20 °, when the anchor main body 1 is screwed into the pilot hole 51, the concrete scrap on the inner peripheral surface of the pilot hole 51 scraped off by the screw thread 14 is removed from the pilot hole 51. If the amount of accumulated in the bottom becomes too large and the concrete scrap interferes to prevent the anchor body 1 from being screwed to a predetermined depth, and if the thread angle of the thread 14 exceeds 27 °, the anchor body 1 Since the amount of screwing into the prepared hole 51 with respect to the rotation of the anchor body portion 1 is increased, a strong force is required for screwing the anchor main body 1 into the prepared hole 51, and workability is deteriorated.

  Therefore, by setting the screw angle of the screw thread 14 to 20 ° to 27 °, the anchor main body 1 can be screwed to a predetermined depth of the prepared hole 51 without deteriorating workability.

  Further, by using the cap nut 3 as a nut to be screwed into the male thread portion 13 of the anchor main body 1, the cap nut 3 after the anchor main body 1 is screwed into the pilot hole 51 compared to the case of using a normal nut. It is possible to easily and quickly perform the escape work.

  Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within a scope not departing from the gist of the present invention are included in the present invention.

For example, in the embodiment, four slits 11 are formed, but the number is arbitrary.
Moreover, in the Example, although the screw angle of the screw thread 14 was 20 degrees-27 degrees, it is not limited to this angle.

  In the embodiment, the cap nut 3 is used as a jig for screwing the anchor main body 1 into the pilot hole 51, but a normal nut can also be used. The effect close to the cap nut 3 can be obtained by rotating the anchor main body 1 by engaging the double nut.

  The inner diameter of the pilot hole 51 drilled in the concrete 5 is not limited to the dimensions described in the embodiment as long as it is larger than the outer diameter of the anchor main body 1 and smaller than the outer diameter of the thread 14.

DESCRIPTION OF SYMBOLS 1 Anchor main-body part 1a Expanding part 11 Slit 12 Axle hole 12a Tapered part 13 Male thread part 14 Screw thread 2 Expanding pin 21 Tapered part 22 Driving head 3 Cap nut 31 Male thread part 32 Top plate part 5 Concrete 51 Pilot hole 52 Female thread 6 Concrete drill 7 Dust absorber 8 Nut 9 Bracket 10 Double nut M Mortar

Claims (5)

The anchor main body portion is composed of an expansion pin, and the anchor main body portion is formed in a cylindrical shape, and a plurality of slits are formed in the axial direction on the peripheral wall of the peripheral wall at predetermined intervals in the circumferential direction. An expansion part is formed, and a base thread side of the anchor main body part has a male screw part capable of screwing a nut, and the expansion pin can be press-fitted into the axial hole of the anchor main body part from the base side. In the post-construction anchor with a structure that has a tapered portion that expands the distal end widened portion of the anchor main body portion at the distal end portion and a driving head at the proximal end portion,
A post-installed anchor characterized in that a screw thread that can be screwed into a prepared hole drilled in concrete is formed on the outer periphery of the anchor body. In the invention of claim 1,
The anchor main body portion is made of a steel material, and at least its thread is quenched. In the post-construction anchor according to claim 1 or 2,
A post-construction anchor, wherein the screw thread has a screw angle of 20 ° to 27 °. The anchor main body portion is composed of an expansion pin, and the anchor main body portion is formed in a cylindrical shape, and a plurality of slits are formed in the axial direction on the peripheral wall of the peripheral wall at predetermined intervals in the circumferential direction. An expanded portion is formed, and a male screw portion capable of screwing a nut is provided on the base side of the anchor main body portion, and can be screwed into a prepared hole drilled in concrete on the outer periphery of the anchor main body portion. A thread is protrudingly formed, and the expansion pin is a rod shape that can be press-fitted into the axial center hole of the anchor main body portion from the base side, and a tapered portion that expands the diameter of the distal end expansion portion of the anchor main body portion is formed at the tip portion. It has a structure that has a driven head at the base end, and is a fixing method for fixing the construction anchor,
A step of opening a pilot hole having a diameter larger than the outer diameter of the anchor main body and smaller than the outer diameter of the screw thread in existing concrete;
Screwing the anchor body into the pilot hole by rotating a nut screwed into the male thread of the anchor body with a tool such as a spanner;
The anchor main body portion is formed by driving the expansion pin into the axial hole of the anchor main body portion so that the expansion portion in which the slit of the anchor main body is formed is radially expanded and pressed against the inner peripheral surface of the pilot hole. Fixing the inside of the pilot hole,
A post-installation anchor mounting and fixing method characterized by comprising: In the fixing method of the post-construction anchor according to claim 4,
A post-installed anchor mounting and fixing method, wherein a cap nut is used as a nut screwed into the male thread portion of the anchor main body portion.

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