JP2002213022A - Bolt insert and its fixing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fit an insert at an accurate position of concrete in a single operation by oneself from both sides of one end of a sheathing board and to prevent a positional shift and an inclination when concrete is placed. SOLUTION: This bolt insert 10 is provided with a stem 12 having a head 11, a protruded male screw 13, a fixing nut 14 screwed to the male screw 13 to position and fix it to a form inner face, a truncated conical skirt 15 having a large diameter and diameter shrinking notches on the fixing nut side and exteriorly coupled with the male screw, and a temporary tacking nut 16 temporarily tacking the skirt 15 to the male screw 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bolt insert and a method for fixing the same.

[0002]

2. Description of the Related Art An insert, also called a bolt attachment, is a member that is pre-installed and buried in concrete, and attaches other equipment or objects to the outer surface of the concrete. The insert is usually formed of a body having a head and a female screw, and is entirely buried in concrete. And only the entrance of the female screw is exposed on the concrete surface so that the male screw bolt can be screwed. Screwing a bolt into this female screw, for example, in construction work, civil engineering work, precast concrete plate manufacturing factory, etc., lightweight ceiling installation, scaffolding support, air conditioning work,
Sanitary work, disaster prevention work, electrical work, communication work, gas work,
It is used to attach various equipment for lifting and lowering work, transport work, etc. to the outer surface of concrete. Further, it has a tension supporting force for suspending various members. It is also used when a pressurizing force is applied to the concrete outer surface to fix and support the mounting equipment on the concrete surface. The insert is made of steel, stainless steel, or resin material according to the purpose. Structures using inserts include reinforced concrete (RC) and steel-framed reinforced concrete (SR
It is used for any structure such as C) structure, steel frame concrete (SC) structure and precast concrete (PC) structure. The pull-out strength of the insert is determined by the screw diameter, trunk diameter, burial depth, head diameter, concrete strength, adhesive strength, etc. of the insert, and is appropriately designed according to the place of use and purpose.

The conventional insert described above is attached to the inner surface of a weir plate of a form by nailing or the like, casts concrete, and buried in the concrete. FIG. 4 shows an example of this, in which a mounting frame 41 of an insert is mounted on a plywood dam board 42 of a concrete form with a nail 43 made of resin or the like by a hammer 44, and an insert 45 is inserted into the mounting frame 41 as shown by an arrow 46. Then, concrete 31 is poured. After the concrete is hardened, the dam is removed, and an impact 47 is applied to the nail 43 with a hammer 44 to damage the nail 43. By screwing the mounting bolt 48 into the insert 45, the insert can be used. The mounting of the insert shown in FIG. 4 is not easy to hold the posture, and the position moves or tilts during concrete casting, so that it may not be easy to accurately bury the insert at a predetermined position in the concrete. . In order to solve such a problem, it was necessary to insert a bolt into the female screw of the insert, pass this bolt through the weir plate of the formwork, and fix it with a nut outside the weir plate. Not only were male screw bolts and nuts required, but also when installing, it was necessary to arrange and install people on both sides of the weir plate.

For the same purpose as the conventional insert, a male screw bolt is projected from a concrete surface instead of a female screw built in concrete, and a fitting such as a nut having a female screw is screwed to the male screw. Also known are bolt inserts for locking various equipment to a concrete surface. Anchor bolts embedded in concrete in advance can also be said to be a type of bolt insert.

Japanese Patent Application Laid-Open No. Hei 7-23113 discloses a fixing device comprising a shaft having an external thread at one end and a washer-shaped fixed stopper, a fixing plate provided at the bottom outer periphery of the other end of the shaft, and a large diameter at the center of the shaft. A bolt-type insert is disclosed in which a washer-shaped stopper is fixed to the outer periphery and integrally formed. This bolt-type insert is attached to a weir plate of a form with a nut and buried in concrete. Attachment must be performed by persons arranged on both sides of the weir plate in cooperation with each other. For example, it has been extremely difficult to attach to a corrugated steel plate used for a lower surface of a concrete slab of a building.

[0006] Japanese Patent Publication No. 7-25449 discloses an anchor bolt for construction to be used as an insert for concrete. In this technique, a single-shaft type bolt body is formed in which a mounting shaft provided with a mounting screw at an upper end and a large-diameter buried shaft are formed continuously, and a retaining flange is disposed in parallel at a vertical position of the buried shaft. An anchor bolt for construction comprising a plurality of triangular detent rib pieces projecting from the outer periphery of the lower portion of the buried shaft portion to the periphery of the retaining flange at the lower end. This anchor bolt is also attached to the dam of the form with a nut and buried in concrete.
It is necessary to mount it by placing people on both sides of the weir plate. Therefore, similarly to the above-mentioned technology, it has been extremely difficult to attach the corrugated steel plate to the lower surface of a concrete slab of a building, for example.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to develop and provide a bolt insert which solves the above problems. More specifically, an object of the present invention is, for example, to place an insert used for suspending a pipe or a heat insulating material on the lower surface of a slab of a building at an accurate position, for example, a weir plate of a formwork (corrugated steel sheet or the like). ) Can be installed by one person with one touch from one side of the surface, and the mounting position does not move or tilt due to concrete casting, and the equipment can be mounted so as to be in close contact with the concrete surface It is to be.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is a bolt insert characterized by the following technical means. That is,
The present invention provides a bolt with a headed stem embedded in concrete and an external thread projecting from concrete,
A fixing nut that is screwed to the male screw and positioned and fixed to the inner surface of the formwork; a frustoconical hakama that has a large-diameter notch for reducing the diameter on the fixing nut side and is externally fitted to the male screw; A bolt insert comprising a temporary fixing nut for temporarily fixing. In this case, when a washer is interposed between the fixing nut and the truncated cone, the washer covers the gap between the fixing nut and the through hole of the weir plate, and the contact between the nut and the surface of the weir plate. Since the number of surfaces is increased, the mounting becomes stable, which is preferable. Temporarily fixing the hakama to the male screw means fixing the hakama from floating in the male screw axial direction. For example, it is preferable that a part of the temporary fixing nut bites into the inner diameter of the hakama.

The method of the present invention for suitably fixing the bolt insert of the present invention is to form an insert mounting hole having a diameter smaller than the large-diameter end of a hakama in a concrete formwork, and to form the formwork in the mount hole. Push the male thread side of the bolt insert from the inside to reduce the diameter of the large diameter end of the hakama, then tighten the fixing nut, sandwich the weir plate between the nut and the hakama, and fix the bolt insert to the formwork A method for fixing a bolt insert, characterized in that: The bolt insert according to the present invention is a truncated cone-shaped hakama having a large diameter on the fixing nut side and a notch for reducing the diameter and externally fitted to a male screw, and an insert mounting hole having a diameter smaller than the large diameter end of the hakama is formed by a concrete mold. When the male screw side of the bolt insert is pushed into the mounting hole from the inside of the form and the large-diameter end of the hakama is passed through the mounting hole, the large-diameter end of the hakama is reduced when passing through the mounting hole. Immediately after the passage, the diameter is expanded and returns to the original diameter. Therefore, the weir plate is sandwiched between the fixing nut and the hakama. By tightening the fixing nut, the bolt insert can be firmly attached to the weir plate in an accurate posture. In this manner, the bolt insert of the present invention can be accurately and securely attached by one person from the concrete-side surface of the weir plate of the formwork.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing a bolt insert 10 according to an embodiment of the present invention. The bolt insert 10 of the embodiment shown in FIG. 1 includes a head 11, a stem 12, and a male screw 13, and includes a form fixing nut 14, a hakama 15, and a hakama fixing nut 1.
It consists of six. The head 11 has such a size that the concrete supports the pull-out force of the insert bolt. For example, it may be formed in a disk shape, and the diameter may be about 3 to 4 times the diameter of the male screw, and the male screw 13 may be 3/8 inch (outer diameter 9 mm).
In this case, the diameter is about 28 to 35 mmφ. The shape is not limited to the disk shape, but may be a rectangular plate or a polygonal plate shape, or may be a horizontal or bar shape having a circular or square cross section. The stem 12 has a length that ensures that the head 11 has the appropriate concrete cover thickness, and a thickness that is compatible with the traction of the bolt and is safe against shearing forces.
If a round bar having the same diameter as the male screw 13 is used, manufacture is easy. Further, a screw may be formed, and the position of the mold fixing nut 14 can be arbitrarily changed, so that the versatility is enhanced.

The male screw 13 has a length and a diameter required for a bolt insert. Bolt insert 1 of the present invention
Reference numeral 0 denotes a nut 14 for fixing the formwork,
5. A hakama fixing nut 16 is attached. As will be described later, the mold fixing nut 14 is
Is positioned and fixed to the inner surface of the mold, and a normal nut can be used. The outer diameter may be large in anticipation of the washer effect. The washer 17 is used as needed. The mold fixing nut may be a nut with a washer.

The hakama 15 is made of a synthetic resin or the like, and is fitted around the male screw 13. The fixing nut 14 has a shape of a truncated cone on the side of the fixing nut 14, and a notch 18 for reducing the diameter is provided on the outer periphery in a large diameter portion thereof. The large-diameter portion has elasticity which is reduced when the outer periphery is pressed and returns to its original state when released. The tip end side of the bolt insert of the hakama 15 is formed to have a small diameter, and has a shaft through-hole that is fitted around the male screw 13 at the shaft center. When the hakama 15 is pushed into the mounting hole formed in the dam plate of the concrete form from the small diameter side, the large diameter portion is reduced in diameter and passes through the mounting hole. In the opposite direction.

The temporary fixing nut 16 is a hexagonal nut having an outer diameter equal to or smaller than the small diameter side of the hakama 15.
3 is a nut having a small outer shape for preventing it from floating in the axial direction. The temporary fixing nut 16 may be formed to bite into the inner diameter of the hakama 15 or may be formed integrally with the hakama 15.

The step of fixing the bolt insert 10 of the present invention to a weir plate will be described with reference to FIGS.

(A) First, it is smaller than the large diameter end of the hakama 15,
An insert mounting hole 23 having a diameter larger than the small diameter end is formed in a desired portion of the dam 21 of the concrete formwork. For example, when the weir plate 21 is a deck plate for placing concrete in a floor slab, a metal hole drill 22 is used to make a hole.

(B) The male thread side of the bolt insert 10 of the present invention is pushed into the mounting hole 23 from the inside of the mold frame as indicated by an arrow 24. The large-diameter end of the hakama 15 is reduced in diameter so that the mounting hole 2
Pass through 3 with a snap.

(C) Lightly insert the bolt insert 10 with the arrow 2
Pull upward as shown by 5 and tighten the fixing nut 14. If necessary, the washer 17 is mounted on the bolt insert in advance. Weir plate 2 between fixing nut 14 and hakama 15
1 and fix the bolt insert to the formwork. This fixation can be reliably performed in a short time by one worker from the inner surface side of the formwork, and the bolt insert 10 is firmly positioned at a predetermined position.

(D) The concrete 31 is cast. The bolt insert 10 does not fall off or tilt,
In addition, the insert can be formed at an accurate position without moving during concrete casting.

(E) After the concrete is hardened, the temporary fixing nut 16 and the skirt 15 are removed, and the bolt insert 10 is formed. The temporary fixing nut 16 and the hakama 15 can be used repeatedly. If necessary, the dam 21 is removed. When the weir plate is a deck plate or the like on the lower surface of the floor slab of the building, there is no need to remove it.

[0020]

According to the conventional insert, the bolt may be insufficiently screwed in. In some cases, the bolt insert of the present invention can completely solve such a problem. In addition, when attaching to the mold, one worker can firmly attach to the predetermined position with one touch from the inner surface side of the mold, and there is no displacement or falling down.

[Brief description of the drawings]

FIG. 1 is a side view of an embodiment of a bolt insert.

FIG. 2 is a view showing a fixing work of the bolt insert of the embodiment.

FIG. 3 is a view showing a fixing work of the bolt insert of the embodiment.

FIG. 4 is a view showing a fixing work of a conventional insert.

[Explanation of symbols]

 Reference Signs List 10 bolt insert 11 head 12 stem 13 male screw 14 formwork fixing nut 15 hakama 16 temporary fixing nut 17 washer 18 notch 21 deck plate (dam plate) 22 drill 23 mounting hole 24, 25 arrow 31 concrete 41 mounting frame 42 dam plate 43 Nail 44 hammer 45 insert 46 arrow 47 impact 48 bolt

Claims (3)

[Claims] 1. A bolt having a stem with a head embedded in concrete and a male screw projecting from the concrete, a fixing nut screwed into the male screw and positioned and fixed to the inner surface of the formwork, and the fixing nut side has a large diameter. A bolt insert comprising: a truncated conical hakama having a notch for reducing the diameter and externally fitted to a male screw; and a temporary fixing nut for temporarily fixing the hakama to the male screw. 2. A washer is interposed between the fixing nut and the truncated cone-shaped hakama.
The described bolt insert. 3. A concrete formwork having an insert mounting hole having a diameter smaller than a large diameter end and larger than a small diameter end of the hakama, wherein the bolt insert according to claim 1 or 2 is placed from the inside of the form with the male screw side leading. Into the mounting hole, reduce the diameter of the large diameter end of the hakama, push it in until the hakama passes through the mounting hole, then tighten the fixing nut, sandwich the weir plate and put the hakama and the fixing nut on both sides. A method for fixing a bolt insert, comprising crimping and fixing the bolt insert to a formwork.