JPH09209505A - Protective cap of joint for screw reinforcing bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sharply reduce the fitting cost by forming the protective cap of the screw hole of a joint for a screw reinforcing bar into a screw shaft screwed into the screw hole or an elastically fitted tapered pin. SOLUTION: A joint 11 is fastened and fixed by a lock nut 13 to the end section of a screw reinforcing bar 12 arranged in a mould 10. The shaft section 17 of a cap 16 is screwed into the screw hole 14 of the joint 11 from a cap hole 15 bored on the mould 10, and the position of the joint 11 against the mould 10 is fixed. Concrete is placed in the mould 10 to form a reinforced concrete structure. After concrete is placed, the cap 16 is removed from the joint 11 and the mould 10, and the mould 10 is removed from the reinforced concrete structure. The shaft section 17 of the cap 16 is again screwed into the screw the 14 of the joint 11, and the screw hole 14 is protected from the mingling of sediment. The drift of the joint 11 is prevented when concrete is placed, and the accurate reinforced concrete structure can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a cap for protecting a screw hole of a screw reinforcing bar joint of a reinforced concrete structure.

[0002]

2. Description of the Related Art Reinforced concrete structures are manufactured by screwing one end of a joint into one end of a screw rebar arranged in a formwork and driving concrete into the formwork. At this time, in order to prevent concrete poured into the screw hole at the other end of the joint from flowing in, as disclosed in JP-A-5-171740, an iron plate is provided at the inlet of the screw hole at the other end of the joint. The dish-shaped cap made of steel was spot-welded.

[0003]

The work of spot-welding the cap made of an iron plate to the entrance of the screw hole at the other end of the joint requires time and effort, which causes an increase in cost. Further, in recent years, it has been required to improve the accuracy of the concrete structure, but it is difficult to meet this demand because the joint is displaced when the concrete is poured.

The present invention has been made to solve these problems, and the purpose thereof is to be able to attach to a joint without spot welding.
Another object is to provide a cap that also helps improve the accuracy of reinforced concrete structures.

[0005]

In order to achieve the above-mentioned object, the means adopted by the present invention is a cap of a synthetic resin molded article comprising a shaft portion and a head having a diameter larger than that of the shaft portion. It is formed on a screw shaft that is screwed into a screw hole or a pin shaft that is elastically fitted. When the shaft of the cap is a screw shaft that is screwed into the screw hole of the joint, the head is hexagonal with a wrench, and the shaft is a straight or tapered pin shaft that elastically fits into the screw hole. When it is done, the head should be disk-shaped.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A cap hole is formed at a position coaxial with a joint screw hole of a reinforced concrete structure casting formwork. The shaft portion of the cap is passed through the hole for the cap from the outside of the mold and fitted into the joint. Pour concrete into the formwork and place a reinforced concrete structure. Remove the cap from the reinforced concrete structure. After removing the formwork from the reinforced concrete structure, the shank is fitted into the screw hole of the joint again. When screwed into the screw hole of the joint from the outside of the form through the shaft part of the cap, or when it is pressed firmly into the screw hole and elastically fitted, the joint is integrally connected with the form, so it shifts when placing concrete. There is no fear.

After the concrete has been cast, the cap is once removed from the joint to remove it from the structure in which the form has been cast, and the cap is fitted into the same joint again to prevent foreign matter from entering the joint.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The cap of the present invention will be described based on the embodiments shown in the drawings. FIG. 1 shows a first embodiment, and as shown in FIG. 1A, a screw rebar 12 is arranged inside a form 10. The joint 11 is fitted to one end of the screw reinforcing bar 12, and the joint 11 is tightened and fixed to the screw reinforcing bar 12 by the lock nut 13.
The end surface of the joint 11 on the jointing side is in contact with the inner surface of the mold 10. Formwork 10
A hole 15 for a cap, which is coaxial with the screw hole 14 of the joint 11 and has a slightly larger inner diameter than the screw hole 14, is formed in this. Hole for that cap 15
The shank 17 of the cap 16 is inserted as indicated by the arrow. Since the cap 16 is a molded product made of synthetic resin and the head 18 is hexagonal, it can be turned by applying a spanner.

As shown in FIG. 1 (b), the shaft portion 17 of the cap 16 which is passed through the cap hole 15 of the mold 10 is attached to the screw hole of the joint 11.
Screw into 14 to fix the position of the joint 11 to the formwork 10. Then, concrete is poured into the formwork 10 to form a reinforced concrete structure. At this time, the screw hole of fitting 11
Since the cap 14 is completely sealed by the cap 16, there is no risk of concrete flowing inside. Further, since the joint 11 is fixed integrally with the mold 10 by the cap 16, there is no possibility that the position of the joint 11 will be displaced due to concrete pouring. Therefore, a reinforced concrete structure with higher accuracy than before can be obtained.

As shown in FIG. 1 (c), after placing concrete, a cap 16 is attached to the joint 11 and the form 10 as shown by an arrow.
Then, the formwork 10 is removed from the reinforced concrete structure. Then, as shown in FIG. 1D, the cap 16
Screw the shaft part 17 into the screw hole 14 of the joint 11 again to
To protect the screw hole 14 from contamination such as earth and sand. The shaft portion 17 of the cap 16 does not need to be limited to the screw shaft.
As shown in the embodiment, a headed straight pin may be used. In this case, since the head portion 18 does not have a wrench, it may be disk-shaped, but the outer diameter of the shaft portion 17 is made slightly larger than that of the joint having no screw hole, and elastically fitted in the screw hole of the joint.

As shown in the third embodiment of FIG. 3, the cap
The shaft portion 17 of 16 can be a tapered pin with a head. In order to elastically fit into the screw hole, the shaft portion 17 has a tip diameter smaller than the screw hole inner diameter of the joint and a root diameter larger than the screw hole inner diameter of the joint.

[0012]

As described above, the cap of the present invention is different from the conventional one in which the end face of the joint on the splice side must be spot-welded, and can be easily screwed or pushed into the screw hole of the joint. Because it can be attached
Not only can the cost required for installation be significantly reduced, but when molding reinforced concrete structures, the formwork and joints can be fixed together to prevent slippage of the joints during concrete placement. Also has an excellent effect that a highly accurate reinforced concrete structure can be produced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a step of placing a reinforced concrete structure using the cap according to the first embodiment of the present invention, and FIG. 1 (a) is a view showing how a cap is attached to a joint arranged with a screw rebar in a formwork. The steps are: (b) a concrete placing step, (c) a step of removing the cap and the formwork from the placed reinforced concrete structure, and (d) a step of attaching the cap to the joint of the reinforced concrete structure again. Shown respectively.

FIG. 2 is a perspective view showing a cap of a second embodiment of the present invention,

FIG. 3 is a perspective view showing a cap of a third embodiment of the present invention,

[Explanation of symbols]

 10: Formwork, 11: Screw rebar, 12: Fitting, 13: Lock nut, 14: Screw hole, 15: Cap hole, 16: Cap, 17: Shaft part, 18: Head part

Claims (2)

[Claims] 1. A shank (17) and a head (18) having a larger diameter than that.
A cap (16) made of synthetic resin, the shaft portion (17) is a screw shaft screwed into the screw hole (14) of the joint (11) for the screw reinforcing bar, and the head portion is a wrench. A protective cap for a screw rebar joint, which is a hanging polygon. 2. A synthetic resin cap (16) comprising a shaft portion (17) and a head portion (18) having a diameter larger than that of the shaft portion, wherein the shaft portion (17) is a joint for screw rebars. Hole in (11) (14)
A protective cap for a screw rebar joint, which is a straight or tapered pin shaft that elastically fits into the.