JP2017048505A - Anchor for concrete slab and method for using the sane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent floating of an embedded body even if there is a variation in the distance between a reinforcing bar and a formwork.SOLUTION: A formwork 23 is paved, and reinforcing bars 20 are arranged in the formwork 23, and an embedded body 21 is disposed in the formwork 23 and is fixed to the reinforcing bars 20 or a cradle. An anchor through-hole 24 is formed in the formwork 23, and a positioning nut 11 is loosened in advance, and an anchor member 7 is inserted to the anchor through-hole 24 and a retaining part 7b is hooked to the peripheral edge of the anchor through-hole 24. By fastening the positioning nut 11 from above, the distance between the anchor member 7 and a hook 10 is adjusted so as to fix the embedded body 21 surely.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a concrete slab anchor and a method of using the same.

  Conventionally, it has been known that a concrete slab constituting a floor of a reinforced concrete apartment or the like is constructed using an embedded body arranged in parallel with a formwork plate. Since this embedded body has a lighter specific gravity than concrete, when placing concrete, the upper end stripe tends to float upward. There is known a hook anchor for concrete slab that prevents this lifting and regulates the cover size of the concrete in the upper part of the upper end reinforcement (for example, see Patent Document 1).

  In a conventional concrete slab anchor, an attachment hole must be formed in order to insert the anchor member into the formwork. When the formwork is removed after placing concrete, the attachment hole remains open. It cannot be used as it is at the installation site.

  Therefore, in Patent Document 2, an anchor member having a retaining portion that can pass through the anchor through-hole formed in the mold and extends beyond the inner diameter of the anchor through-hole after passing through the anchor through-hole, and an upper end of the anchor member And a spacer inserted between the lower end of the connecting portion and press-fitted into the anchor through hole.

JP 2006-348746 A Japanese Patent Laying-Open No. 2015-25331

  However, in the concrete slab anchor of Patent Document 2, when the spacer is pressed into the anchor through hole, if there is variation in the distance between the anchor through hole and the reinforcing bar, the anchor member is sufficiently passed through the anchor through hole. In some cases, the anchor member cannot be fully inserted into the hole, and the anchor member does not fully open, thereby preventing the retaining effect. In such a case, it is possible to adjust the anchor bolt from the bottom of the formwork to increase the distance, but it is a work at a high place looking up from the bottom of the formwork, and other members interfere with workability. There is a problem that is bad.

  The present invention has been made in view of such points, and an object of the present invention is to reliably and easily prevent the embedded body from lifting even if the distance between the reinforcing bar and the formwork varies. .

  In order to achieve the above object, in the present invention, the distance between the through hole of the mold and the reinforcing bar holding member for holding the reinforcing bar or the embedded body can be adjusted from above.

Specifically, in the first invention,
In a concrete slab anchor that prevents an embedded body holding tool that holds a reinforcing bar or an embedded body placed in a formwork from floating,
A hook for hooking the reinforcing bar or the implant holder;
A hook bolt in which a position adjusting nut for retaining the flange is screwed to the upper end side screw portion;
A connecting portion into which the lower end portion of the hook bolt is inserted from the upper through hole at the upper end;
An anchor bolt, the upper end of which is inserted from the lower through hole of the connecting portion and fastened to the connecting portion;
A main body portion that is inserted between the lower through hole of the connecting portion and the head of the anchor bolt and has an outer diameter smaller than the inner diameter of the anchor through hole formed in the mold, and the main body An anchor member provided on the upper side of the portion and capable of passing through the anchor through-hole and having a retaining portion that extends beyond the inner diameter of the anchor through-hole after passing through the anchor through-hole.
By adjusting the tightening position of the position adjusting nut, the distance between the anchor member and the flange is adjustable.

  According to the above invention, even if the distance between the anchor through-hole and the reinforcing bar or the implant holder varies, the position adjusting nut is loosened from above to secure an appropriate distance and prevent the retaining portion. Can be securely inserted and prevented from coming off. For this reason, it is possible to reliably and easily prevent the embedded body from being lifted at the time of placing.

In the second invention, in the first invention,
The above buttocks
A horizontal portion having a through hole inserted through the upper end side screw portion of the hook bolt;
And an engaging portion that extends upward from the horizontal portion and is bent in a hook shape and is engaged with the reinforcing bar or the implant holder.

  According to the above configuration, the reinforcing bar or the implant holder can be easily engaged at an appropriate position with a simple configuration.

In the third invention, based on the usage method of the anchor for concrete slab of the first or second invention, this usage method is:
The process of spreading the formwork,
Arranging the reinforcing bars in the formwork;
Placing the implant in the mold and fixing to the reinforcing bar or the implant holder;
Forming an anchor through-hole in the mold,
Hooking the collar on the reinforcing bar or the implant holder, inserting the anchor member into the anchor through-hole and hooking the retaining portion on the periphery of the anchor through-hole; and
Placing concrete in the mold,
Removing the anchor bolt together with the anchor member;
Removing the formwork,
When the anchor member is press-fitted into the anchor through-hole, the position adjusting nut is tightened or loosened from above to adjust the distance between the anchor member and the flange.

  According to the above invention, even if the distance between the anchor through-hole and the reinforcing bar or the implant holder varies, the position adjusting nut is loosened from above to secure an appropriate distance and prevent the retaining portion. Can spread out and prevent it from coming off. For this reason, it is possible to reliably and easily prevent the embedded body from being lifted at the time of placing.

  As described above, according to the present invention, in the concrete slab anchor, by adjusting the tightening position of the position adjusting nut, the distance between the anchor member and the flange portion can be adjusted, thereby enabling the reinforcing bar or embedded Even if the distance between the insert holder and the formwork varies, the floating of the implant can be prevented reliably and easily.

It is a front view which shows the anchor for concrete slabs. It is sectional drawing which shows a mode that the anchor for concrete slabs is inserted from upper direction. It is sectional drawing which shows a mode that the front-end | tip of an anchor member is press-fit in the through-hole for anchors. It is sectional drawing which shows a mode that it pushes into the through-hole for anchors, and expands a retaining part. It is sectional drawing which shows a mode that the front-end | tip of a retaining part contacts the periphery of an anchor through-hole. It is sectional drawing which shows the mode of concrete placement. It is sectional drawing which shows a mode that an anchor member and a formwork are removed after concrete placement. It is sectional drawing which shows a mode that the anchor for concrete slabs was hooked on the receiving stand.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

−Structure of anchor for concrete slab−
FIG. 1 shows an anchor 1 for a concrete slab according to an embodiment of the present invention. The anchor 1 for a concrete slab is a round bar-shaped hook having an upper end side thread portion 2a formed at the upper end, for example, made of a metal round bar or the like. A bolt 2 is provided. A hook part 10 bent in a U-shape is inserted into the upper end side screw part 2a, and a position adjusting nut 11 for preventing the hook part 10 from coming off is screwed. The flange portion 10 includes a horizontal portion 10a having a through hole (not shown) inserted into the upper end side screw portion 2a of the hook bolt 2, and an engaging portion 10b extending upward from the horizontal portion 10a and bent in a hook shape. And. In addition, although this collar part 10 consists of galvanized steel plates, for example, you may form with other materials, such as a resin molded product.

  And the lower end side screw part 2b is formed in the lower end part of the hook bolt 2. FIG. The collar portion 10 plays a role of hooking on a pedestal 22 as an embedded body holding tool for holding a reinforcing bar 20 or an embedded body 21 described later. The connection part 3 which consists of a resin molded product is fastened to the lower end side screw part 2b, for example. In addition, it is good to keep the screw processing range of the upper end side screw part 2a wider than the lower end side screw part 2b so that the position of the collar part 10 can be adjusted in a wide range.

  The connection part 3 is formed with a circular upper through hole 3a at the upper end, and an upper nut accommodating part 3b having an open front side at the lower side. A length adjusting portion 3c having an open front is formed below the upper nut housing portion 3b. By fastening the lower end side screw portion 2b of the hook bolt 2 to the upper nut 4 that is non-rotatably received from the front side in the upper nut accommodating portion 3b, and by moving the lower end side screw portion 2b forward and backward by the length adjusting portion 3c, The insertion depth of the lower end side screw portion 2b into the connecting portion 3 can be adjusted. In addition, you may insert until the lower end side screw part 2b of the hook bolt 2 contacts the bottom part of the length adjustment part 3c.

  A lower nut housing portion 3d having an open front side is formed below the length adjusting portion 3c. The lower end of the connecting portion 3 is tapered from the lower nut housing portion 3d, and the lower end is formed with a cylindrical thin portion 3e whose outer diameter is further reduced. The small diameter portion 3e is not limited to a cylindrical shape as long as it can pass through an anchor through-hole 24 described later. A lower through hole 3f is formed from the small diameter portion 3e to the lower nut housing portion 3d. The upper end of the anchor bolt 5 is inserted into the lower through-hole 3f and fastened to the lower nut 6 that is housed in the lower nut housing portion 3d so as not to rotate from the front side.

  An anchor member 7 made of, for example, a resin molded product is inserted between the lower through hole 3f of the connecting portion 3 and the head 5a of the anchor bolt 5. A cylindrical main body 7 a having an outer diameter slightly smaller than the inner diameter of the anchor through hole 24 formed in the mold 23 is formed at the lower end of the anchor member 7. On the upper side of the main body portion 7 a, a retaining portion 7 b that can pass through the anchor through-hole 24 and expands beyond the inner diameter of the anchor through-hole 24 after passing through the anchor through-hole 24 is formed. For example, the retaining portion 7b includes only four lower ends connected to the upper end of the main body portion 7a. For example, a pair of spacer abutting portions 7c extending from the upper end of the main body portion 7a in the axial direction of the anchor bolt 5 are formed in a portion where the retaining portion 7b is provided.

  A spacer 8 that is press-fitted into the anchor through hole 24 is sandwiched between the upper ends of the pair of spacer abutting portions 7 c and the narrow diameter portion 3 e of the connecting portion 3. The spacer 8 has a substantially cylindrical shape, and, for example, the lower end side has an outer diameter that is substantially the same as the inner diameter of the anchor through-hole 24 so that the outer diameter is gradually increased toward the upper end in order to prevent the spacer 8 from being pressed out. It is desirable that it is formed so as to spread. In this embodiment, since the connecting portion 3 is formed of a resin molded product, the upper nut 4 and the lower nut 6 are accommodated. However, if the connecting portion 3 is made of metal, the upper through hole 3a and the lower through hole are accommodated. A female screw may be formed in each of the holes 3f.

-How to use anchors for concrete slabs-
Next, a method of using the concrete slab anchor 1 of this embodiment will be described.

  First, the formwork 23 made of a wooden plate material is spread on the construction site.

  Next, the reinforcing bar 20 is placed in the mold 23. The reinforcing bars 20 are assembled in a mesh.

  Next, the embedded body 21 is fitted between the assembled reinforcing bars 20. The embedded body 21 is not particularly limited, such as a polystyrene foam, a hollow resin molded product, an annular hollow member, and a spherical hollow member. In the case of the polystyrene embedded body 21, one is installed in the lattice formed of the reinforcing bars 20. The reinforcing bars 20 are fitted into the recesses 21 a on the upper and lower surfaces of the embedded body 21. On the other hand, in the case of an annular hollow member or the like, as shown in FIG. 8, the embedded body 21 may be arranged and fixed on the receiving base 22 placed on the mold 23. Although the cradle 22 has the leg part 22b which becomes self-supporting, the shape is not specifically limited.

  Next, anchor through holes 24 are formed in the mold 23. The anchor through-hole 24 may be formed at a predetermined position in advance.

  And as shown in FIG. 2, the operation | work which hooks the collar part 10 on the reinforcing bar 20 from the upper part is performed. The reinforcing bar 20 is the upper surface side reinforcing bar 20 fitted in the upper surface side recess 21a. The position of the position adjustment nut 11 is set to a higher position with a margin than the position at which the flange portion 10 can be properly engaged with the reinforcing bar 20 when the reinforcing bar 20 and the mold 23 are arranged without error.

  First, as shown in FIG. 3, the anchor member 7 is inserted through the anchor through hole 24. At this time, conventionally, the flange portion 10 was pressed from above and inserted into the anchor through hole 24 up to the small diameter portion 3e at the lower end of the connecting portion 3. The distance from the formwork may not be maintained. In such a case, the anchor member 7 cannot be inserted sufficiently even if the reinforcing bar 20 is bent as in the conventional case. However, in this embodiment, since the position adjustment nut 11 is positioned above with a margin in advance, it can be easily inserted into the anchor through hole 24 up to the small diameter portion 3e at the lower end of the connecting portion 3. At this time, since the retaining portion 7b is easily bent, the outer diameter decreases when passing through the anchor through-hole 24. In this embodiment, since the length of the upper end side screw part 2a is ensured long, it is easy to adjust the length even when the hook bolt 2 is fixed obliquely.

  As shown in FIG. 4, since the insertion depth of the lower end side screw portion 2b of the hook bolt 2 is set in advance, there is no allowance for the insertion depth for expanding the retaining portion 7b in the insertion work, but the small diameter By inserting up to the portion 3e, the insertion height h1 is secured, and the upper end of the retaining portion 7b is surely expanded. At this time, the lower end of the press-fitted spacer 8 protrudes from the anchor through hole 24.

  Next, as shown in FIG. 5, a gap is secured between the flange portion 10 and the reinforcing bar 20, and when the gap is tightened with an electric screwdriver or the like from above, the upper end of the retaining portion 7 b is secured. Comes into contact with the periphery of the anchor through-hole 24, and the retaining effect is reliably exhibited. The spacer 8 is pulled slightly upward and stops in a state where it is press-fitted into the inner surface of the anchor through hole 24, and the small-diameter portion 3 e comes out of the anchor through hole 24 upward. In addition, as shown in FIG. 8, it is desirable to hook the collar part 10 on the receiving part 22a of the receiving stand 22 similarly. In this case, the position on which the collar portion 10 is hung is not particularly limited, and the length thereof may be shortened in accordance with the position on which the cradle 22 is hooked.

  Next, as shown in FIG. 6, concrete 25 is placed in the mold 23. At this time, since the retaining portion 7b spreads and prevents the hook portion 2 of the hook bolt 2 from being hooked on the reinforcing bar 20 and the receiving portion 22a, the embedded body 21 at the time of placing is lifted by buoyancy. Although it is going to try, the lift can be surely prevented.

  Next, as shown in FIG. 7, the anchor bolt 5 is removed together with the anchor member 7. Since the spacer 8 is press-fitted into the anchor through hole 24, it remains in the anchor through hole 24.

  Finally, the mold 23 is removed together with the spacer 8.

  Therefore, according to the concrete slab anchor 1 according to the present embodiment, even if the distance between the reinforcing bar 20 and the formwork 23 varies, the embedded body 21 is surely prevented from being lifted and the formwork 23 is placed after placement. Can be easily reused.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above-described embodiment, one reinforcing bar 20 is hung on the collar portion 10, but two or more reinforcing bars 20 may be hung at a time.

  In the above-described embodiment, the method using the spacer 8 so that the mold 23 can be reused is shown. However, the spacer 8 is not necessarily required, and a structure without the spacer 8 may be used. In this case, after the formwork 23 is removed, the anchor through-hole 24 remains open.

  The above embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its applications, and uses.

1 Anchor for concrete slab
2 Hook bolt
2a Upper end screw
2b Lower end side thread
3 connecting parts
3a Upper through hole
3b Upper nut housing
3c Adjustment unit
3d Lower nut housing
3e Small diameter part
3f lower through hole
4 Upper nut
5 Anchor bolt
5a head
6 Lower nut
7 Anchor member
7a Body
7b Retaining part
7c Spacer contact part
8 Spacer
10 Buttocks
10a Horizontal part
10b Engagement part
11 Position adjustment nut
20 Rebar
21 Implants
22 cradle
23 Formwork
24 Anchor through hole
25 Concrete

Claims (3)

In a concrete slab anchor that prevents an embedded body holding tool that holds a reinforcing bar or an embedded body placed in a formwork from floating,
A hook for hooking the reinforcing bar or the implant holder;
A hook bolt in which a position adjusting nut for retaining the flange is screwed to the upper end side screw portion;
A connecting portion into which the lower end portion of the hook bolt is inserted from the upper through hole at the upper end;
An anchor bolt, the upper end of which is inserted from the lower through hole of the connecting portion and fastened to the connecting portion;
A main body portion that is inserted between the lower through hole of the connecting portion and the head of the anchor bolt and has an outer diameter smaller than the inner diameter of the anchor through hole formed in the mold, and the main body An anchor member provided on the upper side of the portion and capable of passing through the anchor through-hole and having a retaining portion that extends beyond the inner diameter of the anchor through-hole after passing through the anchor through-hole.
A concrete slab anchor, wherein the distance between the anchor member and the flange is adjustable by adjusting the tightening position of the position adjusting nut. In the concrete slab anchor according to claim 1,
The above buttocks
A horizontal portion having a through hole inserted through the upper end side screw portion of the hook bolt;
An anchor for a concrete slab, comprising: an engaging portion that extends upward from the horizontal portion and is bent in a hook shape and is engaged with the reinforcing bar or the implant holder. In the usage method of the anchor for concrete slabs of Claim 1 or 2,
The process of spreading the formwork,
Arranging the reinforcing bars in the formwork;
Placing the implant in the mold and fixing to the reinforcing bar or the implant holder;
Forming an anchor through-hole in the mold,
Hooking the collar on the reinforcing bar or the implant holder, inserting the anchor member into the anchor through-hole and hooking the retaining portion on the periphery of the anchor through-hole; and
Placing concrete in the mold,
Removing the anchor bolt together with the anchor member;
Removing the formwork,
A concrete slab anchor characterized by adjusting the distance between the anchor member and the flange by tightening or loosening the position adjusting nut from above when the anchor member is press-fitted into the anchor through-hole. how to use.

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