JP3118544B2 - Driving anchor for concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving anchor used for fixing a structure or the like to concrete, bedrock or other base.

[0002]

2. Description of the Related Art The base end of an expanding sleeve inserted into a hole formed in a base is hit, and the distal end of the expanding sleeve is expanded by a cone inserted into the distal end of the expanding sleeve to exert a fixing force. Structured anchors have been known for a long time and are used in many buildings and structures.

[0003] Japanese Utility Model Publication No. 32-5538 discloses, for example, a device in which a saw blade is formed at the tip to give the function of a drill by itself to improve the working efficiency.

[0004] However, the driving anchor disclosed in the above publication has the advantage that a hole having a uniform diameter is formed without the cone and a drilling tool is not required, but the cone is formed again after the hole is formed. , And the work efficiency has not been sufficiently improved.

In particular, the fixing force of the conventional driving anchors, including those disclosed in the above-mentioned publications, is left to the pressing force applied to the perforation wall at the tip of the expanding sleeve expanded by the cone, which is sufficient. It was difficult to obtain a fixing force.

On the other hand, a method is used in which the expansion sleeve is sufficiently expanded by implanting a driving anchor in a so-called undercut hole in which the diameter of the inner part of the hole is made larger than the diameter of the opening, thereby increasing the pull-out strength. However, according to this method, it is necessary to first form a hole having a uniform diameter on the base, and then form an undercut hole using a boring tool. It is disadvantageous in terms of construction time, labor, and economy as compared with the case of performing the above.

Therefore, in order to solve these problems, an expanding sleeve having a cone inserted into the tip is inserted into a hole having a uniform diameter provided on the base, and a hammer drill or the like attached to the base is used. A method has been devised in which an anchor is driven while forming an undercut hole in a wall surface of a perforated hole with a cutting blade formed at a tip of an expanding sleeve main body.

In this case, as shown in FIG. 5, for the purpose of preventing the center axis from being shifted when the anchor is rotated and reducing the frictional resistance of the tip portion due to the rotation, It is conceivable to provide the projection 95 at the tip.

However, when the base 99 is softer than the material of the cone 93, the driving force concentrates on the protrusion 95 when driving the anchor 91, and the cone 93 penetrates deeply into the bottom of the perforation. There is a problem in that the amount of insertion of the cone 93 into the expansion sleeve 92 is insufficient, so that the expansion portion 94 does not expand sufficiently, and thus it is not possible to obtain a predetermined pull-out strength of the anchor.

[0010]

The problem to be solved by the present invention is that when an anchor using a cone having a projection at the tip is driven in, the cone penetrates deeper than a predetermined depth when the base is soft, The point is that the expanding portion of the expanding sleeve does not sufficiently expand.

[0011]

According to the present invention, a cutting blade having a plurality of sharp cutting edges is formed on a distal end surface and has a predetermined length formed from the distal end surface toward a proximal end direction. A plurality of slits form a plurality of enlarged portions and a c for applying rotation and driving force to the base end.
An expanding sleeve that forms the mounting part of the numa drill attachment ,
A cone provided with projections on which the distal end portion inserted into the distal end of the expansion sleeve, the code which is fixed to the tip of the projection cone
And a separate thin plate,
This is means for solving the above-mentioned problems.

[0012]

[Function] Insert the expanding sleeve with a cone at the tip into a hole with a uniform diameter formed on the base and hit the base end while rotating, the expanding sleeve rotates and the cone expands the tip of the expanding sleeve. Let it.

At this time, a temporary fixing
WasThin buried prevention plate separate from coneThe bottom of the perforation
Blocks and prevents burial of protrusions. In addition, thisBuried prevention plate
Is easily detached from the projection by the rotation of the anchor,
When the cone rotates, it receives resistance due to frictional force on the back of the thin plate.
I can't get it.

The expanding sleeve gradually expands the expanding portion while forming an undercut hole in the wall surface of the perforation by the rotary cutting blade formed on the distal end surface.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows an embodiment of the present invention.
The driving anchor 1 includes an expanding sleeve 2 and the expanding sleeve 2.
And a thin plate- shaped burial prevention plate 4 fixed to the tip projection of the cone 3.

The expanding sleeve 2 is formed in a cylindrical shape having a predetermined length, and has a rotary cutting blade 21 having a plurality of sharp cutting edges at a distal end thereof. A plurality of enlarged portions 23 are formed by a plurality of slits 22 having a predetermined length formed in the direction.

A thread groove 24 is formed in the upper part of the inner peripheral surface, and a hammer drill mounting part 2 is provided at the base end.
5 is formed, and a display 26 for confirming the perforation depth is written on the outer peripheral surface. The display 26 is formed, for example, by an annular groove, or is written using paint, and furthermore, using an annular groove and paint.

As the cone 3 to be inserted into the distal end of the expanding sleeve 2, a cone having a projection 31 formed at the distal end of a truncated cone is used among those used in a conventional driving anchor.

The projection 31 at the tip of the cone 3 has
In front of a thin plate with a thickness of about 1.0 to 1.6 mm
An burial prevention plate 4 separate from the cone 3 is temporarily fixed. As a material of the burial prevention plate 4, a hard and high-strength metal such as iron is used, and is temporarily fixed to the projection 31 at the tip of the cone by spot welding or an adhesive.

Next, a method of using the present invention will be described.

To use this embodiment, first, FIG.
As shown in FIG. 1A, a hole 6 having a predetermined diameter and depth and having a uniform diameter is formed in a base 5 made of concrete or the like on which the driving anchor 1 is to be mounted.

Next, as shown in FIG. 3B, a driving anchor 1 in which a cone 3 to which an burial prevention plate 4 is temporarily fixed is inserted at the end of the expanding sleeve 2 is inserted into a hole 6 having a uniform diameter.

At this time, it is confirmed whether or not the display 26 for measuring the perforation depth formed on the outer peripheral surface of the expanding sleeve 2 matches the base surface 51. When the display 26 is located above the substrate surface 51, the hole is further drilled because the drilling depth is insufficient, and when the display 26 is located below the substrate surface 51, that is, the display 26 In such a case, the perforation 6 is too deep. For example, the depth of the perforation is adjusted by arranging a seat plate at the bottom of the hole. If the drilling depth is not enough, the base end of the expanding sleeve 2 is driven in a state protruding from the surface 51 of the base 5, and if the drilling depth is excessive, the insertion amount of the cone 3 is reduced. This is because the expansion portion 23 does not expand sufficiently and the predetermined pull-out strength cannot be obtained. Note that there is a similar concern when the cone 3 has cut into the perforated bottom 62.

Thereafter, a mounting box 82 for the hammer drill 8 is mounted on the mounting portion 25 formed at the base end of the expanding sleeve 2 via a hammer drill mounting tool 81.

When the hammer drill 8 applies rotation and tapping force, the burial prevention plate 4 is pressed against the perforated bottom 62 to prevent rotation, and the burial prevention plate 4 and the cone 3 are temporarily fixed. Is released, and the expanding sleeve 2 itself rotates, and the cone 3 is pressed into the distal end of the expanding sleeve 2.

At this time, the burial prevention plate 4 is disposed at the perforated bottom 62 to prevent the cone 3 from being buried and to maintain the depth of the cone tip constant.
There is no need to worry about shaving 2 and getting in. Further, since the fixing point 41 between the burial prevention plate 4 and the cone 3 can be easily removed, the tip portion does not receive frictional resistance when the expanding sleeve 2 and the cone 3 rotate.

Accordingly, the expanding sleeve 2 is expanded while forming the undercut hole 63 by cutting the hole wall 61 of the perforation 6 by the rotary cutting blade 21 formed on the distal end surface of the expanding portion 23. As shown in FIG. 3C, when the expansion sleeve 2 is driven into the base 5 until the expansion sleeve 2 is almost completely buried in the base 5, the cone 3 is pressed into the distal end of the expansion sleeve 2 by a predetermined depth. The subdivision 23 is expanded at a predetermined angle and the driving operation is completed.

Further, when a recess 42 is formed in the center of the burial prevention plate 4 so that the projection 31 at the tip of the cone abuts, the center axis is maintained even after the burial prevention plate 4 comes off from the tip of the cone when the anchor is driven. Can be kept constant.

Although the rotary cutting blade 21 of the expanding sleeve 2 according to the present embodiment is a straight blade whose sharp edge is directed toward the front end, it may be formed as a beveled blade like a saw blade.

In this embodiment, the hammer drill 8 is used to apply the rotation and the driving force to the driving anchor 1. However, other methods may be used as long as the rotation and the driving force are applied at the time of driving.

[0032]

According to the driving anchor of the present invention, an anchor exhibiting sufficient pull-out strength can be driven by the same simple operation as in the prior art.

Further, since the structure of the anchor is not complicated, it is suitable for mass production.

Furthermore, by forming a depression in the center of the burial prevention plate, the center axis can be kept constant at the time of anchor driving, so that the perforation does not expand and a more stable pull-out resistance can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of FIG.

FIG. 3 is an explanatory diagram showing a use state in the embodiment shown in FIG. 1;

FIG. 4 is a perspective view showing a different embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Driving anchor 2 Spreading sleeve 3 Cone 4 Buried prevention plate 21 Rotating cutting blade 22 Slit 23 Spreading part

Claims (2)

(57) [Claims] 1. A cutting blade having a plurality of sharp edges on a distal end surface is formed, and is formed from a distal end surface toward a proximal end and applies rotation and driving force to the proximal end.
An expansion sleeve in which a plurality of expansion portions are formed by a plurality of slits having a predetermined length and in which a mounting portion of a hammer drill attachment for forming the mounting portion is formed. A concrete driving anchor, comprising: a cone provided with a projection ; and a thin burying prevention plate which is separate from the cone temporarily fixed to a tip of the projection of the cone . 2. The concrete driving anchor according to claim 1, wherein a burying prevention plate in the form of a thin plate having a depression formed in the center is used.