JPH0617631B2 - Equipment for forming through holes in concrete structures - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a through hole forming device used to form a through hole for inserting a water pipe, an electric wire or the like in a beam portion of a concrete structure, for example. .

<Prior Art> The present applicant previously filed Japanese Patent Application No. 62-157806.
We proposed "a tool for forming through holes" together with "a method for forming through holes". The outline will be described below with reference to FIGS. 3 to 6.

The through-hole forming device 1 is formed of a support rod 2 and a neutral body 3.

The support rod 2 has an elongated tubular shape and is provided with “expansion / contraction portions” at both ends. That is, a threaded expansion / contraction portion 4 that expands / contracts in the arrow A direction by screwing is provided at one end, and a slide expansion / contraction portion 7 that expands / contracts by loosening the push screw 5 and sliding in the arrow A direction is provided at the other end. Has been. Then, the screw expansion / contraction part 4
A flange portion body 9 having a sharp portion 8 is provided at the tip of the slide expansion / contraction portion 7, and the tip of the slide expansion / contraction portion 7 is sharpened to form a sharp portion 10. The size of the support rod 2 is usually 10 to 20 mm in diameter and 250 to 600 in length.
mm.

A mounting hole 12 is formed in the center of the core body 3, and a mounting crack 13 is radially formed from the mounting hole 12. The length size L of the core body 3 is usually set to be equal to or less than the gap 15 of the reinforcing bar 14 according to the concrete structure,
The width size W depends on the size of the through hole to be formed.

This through-hole forming device 1 is formed in a form 17 corresponding to a predetermined shape of a concrete structure, and is used by being installed in a form 18 in which a reinforcing bar 14 assembled into a predetermined shape is installed. It is a thing. Specifically, first, the support rod 2
The approximate length difference is adjusted to the size of the formwork 18 by the slide expansion / contraction part 7, and then the support rods 2 are attached to the formwork materials 1 on both sides.
If it is inserted between 7 and 17 and rotated as indicated by arrow X, the threaded expansion / contraction part 4 stretches and stretches, and at the same time, both sharp parts 8 and 1
0 bites into the form material 17 and becomes a fixed state. Therefore, the necessary number of inserts 3 are spread over the entire length of the support rod 2 in the mounting cracks 13 in the direction of arrow B, and finally through the mounting holes 12 in the direction of arrow C (FIG. 2). Install from. Finally, concrete is poured into the mold 18 and, after the concrete is hardened, the support rod 2 is removed and the core 3 is removed to form a through hole.

The effect of such a through hole forming device 1 is that both the support rod 2 and the core 3 are of a size that easily passes through the gaps between the reinforcing bars, and Since it is fixed between the frame members 17 only by rotating, and the core 3 is simply mounted on the support rod 2 in sequence, even in a working space where the reinforcing bars 14 are intricately narrowed. Easy to do.

-In addition, the support rod 2 is a "cylindrical rod" with a diameter of 10 to 20 mm.
Since this is nothing but a worker, for example, a carpenter's nail bag can carry many of them at once, and the core 3 is also a very light one made of synthetic resin foam. Therefore, for example, you can carry many pieces in a large bag.

-And, as a result, the workability will be improved.

It is ...

<Problems to be Solved by the Invention> However, in the through-hole forming device 1 according to the above proposal,
Although the support bar 2 is expandable and contractible, the expansion and contraction is up to the transfer and fixing. Once it is transferred and fixed, the width S of the form material 17, 17 rolls is poured into it. When it spreads due to the pressure of the concrete that has been eroded, it cannot follow this, and depending on the extent of the spread, both sharpened parts 8 and 10 that have been bitten out from the form material 17 and the support rod 2
There was the inconvenience that there was a phenomenon in which the tape came off and slipped.

In order to eliminate this inconvenience, the support rod 2 should be provided with expansion and contraction elasticity (elasticity for stretching in the direction of arrow D) at the same time as ensuring the expansion and contraction of the entire structure. It is how to give elasticity. In other words, the structure and shape of the support rod 2 is not made too complicated, the size is not made too large, and elastic elasticity is given, and the "easy-to-use" can be set easily as described above. How to do that.

<Means for Solving the Problems> As means for solving the above problems, in the present invention, in a through-hole forming device including a support rod and a core body, the support rod is the first tube body and The second tubular body is formed by the second tubular body, and the second tubular body can be fitted into the first tubular body by screwing the coil spring in the first roll body and the thread portion of the second tubular body so that the entire body expands and contracts. The gist of the invention is to make it flexible and at the same time to give expansion and contraction elasticity to the support rod by the coil spring.

<Operation> The greatest feature of this through hole forming device is that one coil spring provided in the first tubular body is used as a “screw” for the support rod, and one is a “spring”. By using it as “”, the entire expansion and contraction and expansion and contraction elasticity are realized at once. As a result, the structure and shape of the support rod can be made not to be too complicated, and the size can be made not to be too large.Although it is such a simple structure, it is always in any stretchable state. Elastic elasticity is obtained, so to speak, it is "unified"
Therefore, the support rod can be set "one-touch". Therefore, this "through-hole forming device" is very easy to use, and at the same time, the instability of coming off or shifting is eliminated and certainty can be obtained.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the following description, the same parts as those of the above-described conventional technique are designated by the same reference numerals, and the duplicated description will be omitted.

The support rod 30 of this "through hole forming device" is formed of a first tubular body 31 and a second tubular body 32. Second tube 3
2 is adapted to be freely inserted into the first pipe body 31, and specifically, the coil spring 33 provided inside the first pipe body 31 and the inner surface of the second pipe body 32 are It is adapted to be fittable by a "screw mechanism" by screwing with a "screw portion" formed by a pair of projecting portions 34, 34 which are projected, and the support rod 30 is fitted by this fitting. The whole is made flexible. Moreover, this coil spring 3
The elastic member 3 expands and contracts elastically on the support rod 30 (form material 17, 17) by exhibiting a "spring" function simultaneously with the "screw" function.
7 also provides elasticity for generating a crushing tension in the direction of the arrow D when it is handed over and fixed.

In this embodiment, the pitch of the coil spring 33, which mainly functions as a "screw" function, is widened so that the expansion and contraction can be performed more quickly. However, such a configuration is not essential. Absent. Also, the “thread portion”
Is formed by a pair of protrusions 34, 34, but the present invention is not limited to this. Further, as a “sharp part”, one needle-like protrusion 35 is provided on the crown portion 36 on the first pipe body 31 side, and a pair of needle-like protrusions 37 is also formed on the second pipe body 32 side on the crown portion 38.
However, the present invention is not limited to this, but the tip of the "tube" itself may be sharpened.

The greatest feature of this "through hole forming device" is the support rod 30.
In, the one coil spring 3 provided in the first tubular body 31
3 is used as "screw" for one and "spring" for one
It is that the entire expansion and contraction and expansion and contraction elasticity are realized all at once by using as. This has the advantage that the structure and shape of the support rod 30 can be made not to be too complicated and the size thereof not to be made too large. Even when it is in a stretched state, the stretchable elasticity is always obtained, and the stretchable elasticity of the whole is "integrated", which is an advantage that the support rods 30 can be set in a "one-touch type". As a result, this "through-hole forming device" is very easy to use, and at the same time, the instability of coming off or shifting is eliminated and certainty is obtained.

<Effects of the Invention> In the through hole forming instrument according to the present invention, as described above, the support rod, which is one member of the instrument, is a "screw" for one coil spring provided in the first tubular body. It has the characteristic that the entire expansion and contraction and expansion and contraction elasticity are realized at once by using it as a "spring". As a result, if the structure and shape are not too complicated. In addition, the size does not have to be too large, and even with such a simple structure, elastic elasticity can always be obtained in any expansion and contraction state. Since it is possible to set with "one-touch type", it is very easy to use, and at the same time, the instability of falling out and shifting is eliminated and the excellent effect that reliability can be obtained There is.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a support rod, FIG. 2 is a schematic perspective view of the support rod, FIG. 3 is a schematic side view of a conventional support rod, and FIG. FIG. 5 is a schematic perspective view of a support rod, FIG. 5 is a schematic perspective view showing a state in which a through-hole forming instrument is installed in a mold, and FIG. 6 is a schematic side view seen from a direction of an arrow VI in FIG. It is a figure. 1 ... Through hole forming device 2, 30 ... Support rod 3 ... Core body 8, 10 ... Sharp part 14 ... Reinforcing bar 17 ... Formwork material 18 ... Formwork 33 ... Coil spring 35, 37 ... Needle-like protrusions (sharp parts)

Claims (1)

[Claims] 1. A support rod which is formed corresponding to a predetermined shape of a concrete structure and which is inserted into a form frame in which a reinforcing bar assembled in a predetermined shape is installed, and a mounting hole is formed in a central portion. At the same time, a mounting crack is formed in the mounting hole in a radial direction, and the supporting bar is formed by a plurality of core bodies mounted on the supporting rod so that the supporting rod is housed in the mounting hole through the mounting crack. In the through hole forming device in which the concrete poured into the mold with the core body attached over the entire length of is removed for the through hole part, the support rods each have a sharp portion at the end. The second tubular body is formed by the first tubular body and the second tubular body, and the second tubular body can be fitted into the first tubular body by screwing the coil spring in the first tubular body and the thread portion of the second tubular body. By making it possible to expand and contract as a whole At the same time, an instrument for forming a through hole in a concrete structure, characterized in that it is given elastic elasticity by the coil spring.