JPH0572504B2 - - Google Patents

Description

Detailed Description of the Invention <Field of Application of the Invention> The present invention relates to a through-hole forming tool used for forming through-holes for passing water pipes, electric wires, etc. into, for example, beams of concrete structures. .

<Prior art> As an instrument for forming through holes, for example,
Those disclosed in No. 16031 and Utility Model Publication No. 53-20902 are known. All of these conventional techniques have a structure in which a block-shaped filler (former body, elastic block) is attached to a support rod (rod, support rod) that is passed into the formwork, and this filler allows the formwork to The concrete poured into the hole is removed from the corresponding portion to form the through hole.

The most important requirements for such through-hole forming instruments are the ability to accurately form the necessary through-holes at the required positions and good workability, but each of the above-mentioned conventional techniques has a high degree of accuracy. Although these points are satisfied, there are some issues in terms of workability.
That is, each of the above-mentioned conventional technologies adopts a structure in which the support rod penetrates the formwork plate, so it is necessary to drill holes in the formwork plate, and the reinforcing bars are complicated and difficult to work under. This requires the troublesome work of fitting both ends of the support rod into the holes in the formwork plate, and there is a big problem in overall workability.

<Problems to be Solved by the Invention> Therefore, an object of the present invention is to provide a through-hole forming tool that can accurately form through-holes and has excellent workability.

<Means for Solving the Problems> As a means for solving the above problems, in this invention, reinforcing bars are formed to correspond to a predetermined shape of a concrete structure and assembled into a predetermined shape. A support rod that extends into the formwork and a mounting hole are formed in the center, and mounting cracks are formed radially from the mounting hole, and the support rod is inserted into the mounting hole through the mounting crack. It consists of multiple core bodies that are attached to the support rod so that they fit together, and the concrete that is poured into the formwork with the core bodies attached over the entire length of the support rod is excluded from the part for the through hole. Regarding the through-hole forming instrument, the support rod has a main body part which is elongated and hollow at least at both ends, a sharp part at the distal end part, and a proximal end part which is screwed into one end side of the main body part. The threaded telescopic part is screwed together so as to be adjustable, and the distal end has a sharp part, and the proximal end can be fixed to the other end of the main body with a push screw, and the fitting length can be adjusted. It is made up of a slide extension and contraction part.

<Function> In this device for forming through-holes, when passing the support rod into the formwork, first adjust the overall length of the support rod using the slide extension to match the width of the formwork. Temporarily fix it at a predetermined passing position within the frame, and then adjust the threading length of the threaded telescopic part while turning the main body, so that the sharp parts of the sliding telescopic part and the threaded telescopic part are fully attached to the formwork board. It is done by stretching it so that it digs into it.

Therefore, a sufficiently strong supporting force is given to the support rod to ensure accuracy in forming the through hole, and the work of passing the rod is essentially just a matter of temporarily setting it at the required position and turning the main body. Since it only requires a lot of work, much better workability can be obtained.

<Example> Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 4.

This through-hole forming instrument 1 is formed from a support rod 2 and a core body 3.

The support rod 2 is preferably made of metal and has an elongated cylindrical shape whose thickness is usually 10 mm to 20 mm to withstand the flow pressure of concrete, which will be described later, and has "expandable parts" at both ends. . That is, it has a main body part 2a made of a metal pipe in the center, and one end of this main body part 2a has a threaded extensible part 4 that expands and contracts in the direction of arrow A, and the other end has a push screw 5. Each slide extension/contraction part 7 is provided which expands and contracts by loosening and sliding in the direction of arrow A. and,
A jagged member 9 is provided at the distal end of the threaded telescopic portion 4, and the distal end of the slide telescopic portion 7 is sharpened to form a sharp portion 10.

The core body 3 has a mounting hole 12 formed in the center,
Further, a mounting crack 13 is formed in a radial direction from the mounting hole 12. Core body 3 length size L
The gap between the reinforcing bars 14 is usually set to 15 or less depending on the concrete structure, and the width size W is set depending on the size of the through hole to be formed. The core body 3 of this embodiment is made of polystyrene foam because it is lightweight, easy to handle, and has the necessary strength against concrete, but it is not necessarily limited to this.

Hereinafter, how to use this through-hole forming instrument 1 will be explained.

This through-hole forming device 1 is formed using a formwork material 17 to correspond to a predetermined shape of a concrete structure, and is installed in a formwork 18 in which reinforcing bars 14 assembled into a predetermined shape are installed. First, support rod 2
The approximate length of the main body 2a is adjusted to the size of the formwork 18 using the sliding telescopic part 7, and then the support rod 2 is passed between the formwork members 17, 17 on both sides to rotate the main body part 2a in a predetermined direction. Then, the threaded telescopic portion 4 stretches and tightens, and at the same time, both sharp portions 8 and 10 bite into the formwork material 17 and become fixed. Then, over the entire length of this support rod 2, the required number of core bodies 3 are slightly expanded in the direction of arrow B in the mounting crack 13, and finally they are inserted in the direction of arrow C (second direction) through the mounting hole 12.
Attach from the figure). Finally, concrete is poured into the formwork 18, and after the concrete has hardened, the support rods 2 and the core bodies 3 are removed to form through holes.

This work requires that both the support rod 2 and the core body 3 are of a size that allows them to easily pass through the gaps between the reinforcing bars, and that the support rod 2 is fixed between the formwork materials 17 by simply passing it across and rotating. Since the core body 3 is simply attached to the support rod 2 one after another, it can be easily carried out even in a narrow work space where the reinforcing bars 14 are complicated. Also,
The support rod 2 is nothing more than a ``cylindrical rod'' with a thickness of about 10 mm to 20 mm, so a worker can carry several rods at once by putting them in something like a carpenter's nail bag. Similarly, since the core body 3 is also very light, it is possible to carry several pieces at once in a large bag, for example. As a result, workability can be improved.

Moreover, since the sharp parts 8 and 10 of the support rod 2 are designed to bite into the formwork material 17 when the support rod 2 is passed, sufficient resistance against the concrete flow pressure of the through-hole forming tool 1 can be easily obtained. It also becomes.

FIG. 5 shows a core body 20 according to another embodiment. This core body 20 is provided with a through-hole reinforcing material 21 on its circumferential side. That is, when forming the through hole 23 using this core body 20, the core body 2
After removing 0, the through hole reinforcing material 21 becomes the through hole 2.
3 remains embedded in the concrete 22 around the through hole T, thereby reinforcing the area around the through hole T.

Incidentally, in the above embodiment, the core body was circular based on the assumption that the through hole was circular, but if the through hole is square, it goes without saying that the core body would also be square. be.

<Effects of the Invention> As explained above, the through-hole forming instrument according to the present invention has a structure in which the support rod is provided with a threaded telescopic portion and a slide telescopic portion at each left and right end of the main body, and The support rod can be firmly fixed across the formwork by simply rotating the main body after temporarily fixing it at the required position within the formwork.
Accurate formation of through-holes is possible, and extremely superior workability can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of the support rod, FIG. 2 is a schematic perspective view showing the state in which the support rod is equipped with a core body,
Fig. 3 is a schematic perspective view showing the state in which the through-hole forming instrument is installed in the formwork, Fig. 4 is a schematic side view seen from the direction of the arrow in Fig. 3, and Fig. FIG. 6 is a schematic perspective view of a core body according to an embodiment, and FIG. 6 is a schematic side view of a through hole reinforced with a through hole reinforcing material. 1... Instrument for forming through holes, 2... Support rod, 3,
20... Core body, 4... Threaded telescopic part, 7... Slide telescopic part, 8, 10... Sharp part, 12... Mounting hole, 13... Fitting crack, 14... Rebar, 15
...Gap, 17...Formwork material, 18...Formwork.

Claims (1)

[Scope of Claims] 1. A support rod that is formed to correspond to a predetermined shape of a concrete structure and that is inserted into a formwork in which reinforcing bars assembled into a predetermined shape are installed, and a mounting hole is formed in the center. At the same time, a mounting crack is formed in a radial direction from the mounting hole, and a plurality of core bodies are mounted on the support rod so that the support rod is accommodated in the mounting hole through the mounting crack, In a device for forming a through-hole, in which the concrete poured into the formwork with the core body attached over the entire length of the support rod is excluded from the part for the through-hole, the support rod is elongated and has at least both ends. A hollow main body part, a threaded telescopic part having a sharp part at the distal end part and a proximal end part screwed onto one end side of the main body part so that the threading length can be adjusted, and a sharp part at the distal end part. A through-hole characterized in that it is formed by a sliding extendable part whose base end can be fixed to the other end side of the main body part with a push screw and can be fitted so that the fitting length can be adjusted. Forming instruments.