JPH116249A - Connecting device for threaded reinforcing bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting device for a threaded reinforcing bar, capable of reducing the injection pressure of grout, and enabling the use of a grout of high viscosity. SOLUTION: A joint 10 has injection holes 13, one formed in a position halfway between its center and one end 10a, and one in a position halfway between its center and the other end 10a. An annular groove 14 leading to the injection holes 13 is formed on the inner peripheral surface of the joint 10. Further, a checking window 12 formed of an oblong hole is formed in the center of the joint 10. A pair of threaded reinforcing bars 1 are engaged in the joint 10, and, as their ends 1x are checked through the checking window 12, grout is injected from each injection hole 13. The grout flows into the annular groove 14 and separates in two directions from the annular groove 14, with one flow going toward the end 10a (10b) of the joint 10 through the gap between the joint 10 and the threaded reinforcing bar 1, and the other going toward the center of the joint 10. This grout packing course is shorter than conventional ones.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting device for a screw rebar which secures connection strength by injecting a grout material into a joint.

[0002]

2. Description of the Related Art In a connecting device for a screw rebar, a grout material is injected from an injection hole formed in the center of the joint after the ends of a pair of screw rebars to be connected are screwed into a cylindrical joint. The grout material reaches both ends of the joint through a gap between the inner peripheral surface of the joint and the outer peripheral surface of the threaded reinforcing bar. When the grout material leaks from both ends of the joint, the operator confirms the completion of the filling of the grout material and ends the pouring operation. The hardened grout plays a role in increasing the connection strength of the screw rebar.

[0003]

In the above device, an injection hole is formed in the center of the joint, and the distance between the injection hole and both ends of the joint is long. Therefore, when grout is injected into the narrow gap between the joint and the screw reinforcing bar, the injection pressure has to be increased. This disadvantage is particularly noticeable when the joint is long. In addition, in order to lower the injection pressure, it is required to use a grout material having a low viscosity, which narrows the range of selection of the grout material.

[0004]

According to the first aspect of the present invention, there is provided an apparatus for connecting threaded reinforcing bars by injecting a grout material in a state where ends of a pair of threaded reinforcing bars are screwed to a joint. An injection hole for injecting a grout material is formed in the joint at an intermediate position between the center and one end in the longitudinal direction and an intermediate position between the center and the other end, respectively. According to a second aspect of the present invention, in the coupling device for a threaded reinforcing bar according to the first aspect, the inner peripheral surface of the joint includes:
An annular groove connected to each of the injection holes is formed. The invention of claim 3 is the invention of claim 1 or 2
In the coupling device for a threaded reinforcing bar described in (1), a confirmation window for confirming the tips of both threaded reinforcing bars is formed at the center of the joint.

A fourth aspect of the present invention is an apparatus for connecting threaded reinforcing bars by injecting a grout material in a state where the ends of a pair of threaded bars are screwed to the joint. In the center in the longitudinal direction, an injection hole for injecting the grout material is formed, and further, on the inner peripheral surface of the joint, a vertical groove extending in the longitudinal direction is formed, and the center of this vertical groove is connected to the injection hole, One end extends to an intermediate position between the center of the joint and one end of the joint, and the other end extends to an intermediate position between the center of the joint and the other end of the joint. According to a fifth aspect of the present invention, in the connection device for a screw rebar according to the fourth aspect, two annular grooves are further formed on an inner peripheral surface of the joint, and these annular grooves are respectively connected to both ends of the vertical groove. It is characterized by having. According to a sixth aspect of the present invention, in the coupling device for a screw reinforcing bar according to the fourth or fifth aspect,
The joint is characterized in that a confirmation window for confirming the tips of the two threaded reinforcing bars is formed at a position circumferentially away from the injection hole. According to a seventh aspect of the present invention, in the connection device for a threaded reinforcing bar according to the third or sixth aspect, a cap for closing the confirmation window when the grout material is injected from the injection hole is provided.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A connecting device for a screw rebar according to a first embodiment of the present invention will be described below with reference to FIGS. As shown in FIGS. 1 (A) and 2 (A), a joint 10 used in the present embodiment has a hexagonal cylindrical cross section, and a threaded reinforcing bar 1 is screwed onto an inner peripheral surface thereof. Female screw 11
Are formed.

[0007] A pair of confirmation windows 12 are formed at the center in the longitudinal direction of the joint 10 so as to face each other in the radial direction. The confirmation window 12 is for visually recognizing the distal end 1x of the double-threaded reinforcing bar 1 from the outside, and includes a long hole having a length L extending in the longitudinal direction. From both ends of the confirmation window 12 to both ends 10 of the joint 10
The distances D to a and 10b are equal. This distance D
Is equivalent to the minimum necessary screwing depth of the screw reinforcing bar 1.

In the joint 10, circular injection holes 13 for injecting grout material are formed at an intermediate position between the center in the longitudinal direction and one end 10a and an intermediate position between the center and the other end 10b. ing. In the present embodiment, these two injection holes 13 are arranged at the center of a distance D between the end of the confirmation window 12 and the ends 10a and 10b of the joint 10, respectively. These injection holes 13 are provided at the ends 10a, 1 of the joint 10.
0b may be formed at a position corresponding to a distance of 1/4 of the entire length of the joint 10. The two injection holes 13 and one of the pair of confirmation windows 12 are linearly arranged along the longitudinal direction of the joint 10.

On the inner peripheral surface of the joint 10, two annular grooves 14 are formed. These annular grooves 14 correspond to the positions where the injection holes 13 are formed, respectively.
It is connected to.

In the above configuration, when connecting a pair of threaded reinforcing bars 1, first, the joint 10 is screwed to one threaded reinforcing bar 1 over the entire length, and the other threaded reinforcing bar 1 is arranged on the same straight line. At the same time, the end faces of the screw rebars 1 are brought into contact with each other or brought close to each other. In this state, the joint 10 is turned, and about half of the joint 10 is screwed into the other threaded reinforcing bar 1. Note that the joint 10 may be screwed to the joint 10 by turning the other screw reinforcing bar 1 in a state where the joint 10 is half screwed to the one screw reinforcing bar 1.

Next, looking through the confirmation window 12 of the joint 10,
Check whether the tips 1x of both the screw rebars 1 are visible. As shown in FIGS. 1 (B) and 2 (B), when the tip 1x is seen from the confirmation window 12, both the screw reinforcing bars 1 are screwed to the joint 10 in a state where a necessary screwing depth is secured. Is determined to have been made, and the process proceeds to the next grout injection step. If both or one of the threaded rebars 1 cannot be seen from the confirmation window 12, it is determined that the required threading depth is not attained, and the screw thread of the invisible threaded rebar 1 is inserted into the confirmation window 12 by the tip 1x. Proceed until visible.

Two marks are formed near the confirmation window 12 within the length L of the confirmation window 12, and when the tip 1x of the screw reinforcing bar 1 is located at these two marks, May be determined to be screwed at the required screwing depth.

When the screwing is completed, the tip of the nozzle of the injector 50 is applied to the injection hole 13, and a grout material (not shown) such as cement milk or filled epoxy resin is injected. The grout material is filled from the injection hole 13 into the annular groove 14, and is separated into two hands from the annular groove 14.
One penetrates into the gap between the inner peripheral surface of the joint 10 and the outer peripheral surface of the screw reinforcing bar 1 toward the end 10a (10b) of the joint 10, and the other passes through the gap between the joint 10 and the screw reinforcing bar 1. To the center of the joint 10. Grout material is end 1 of joint 10
When leaking from the end of the confirmation window 12 as well as leaking from 0a (10b), filling of the grout from the injection hole 13 is completed.

As described above, the grout material filling path is divided into two parts, and the grout filling path is formed through the injection hole 13 and the end 10 a of the joint 10.
(10b) and from the injection hole 13 to the center of the joint 10, and these paths are different from the distance from the injection hole formed in the center of the joint to the end of the joint as in the conventional device.
About half. Therefore, the injection pressure may be low, and it is possible to use a grout material having a relatively high viscosity.
Moreover, the grout material injected into the injection hole 13 is
4 from the entire circumference of the annular groove 14 toward the end 10a (10b) and the center of the joint 10, respectively, so that the injection pressure can be further reduced and the threaded rebar 1
And the joint 10 is securely filled over the entire area.

When the grout material is injected, 1
The injection into one injection hole 13 may be performed first using one injector 50, and after that, the injection into the other injection hole 13 may be performed. Alternatively, both injections may be performed using two injectors 50. The holes 13 may be simultaneously injected. Furthermore, two tubes may be attached to one injector, and the nozzle member attached to the tip of the tube may be applied to the two injection holes 13 to simultaneously inject the grout material.

Since the check windows 12 are arranged so as to face each other in the radial direction, even if the grout material blocks the check windows 12, a long bar is passed through the two check windows 12 to easily remove the grout material. can do. Therefore, even after the grout material is injected, the screwing depth of the screw reinforcing bar 1 can be confirmed. In the past, marking was performed in advance at a position separated by a predetermined distance from the end of the screw reinforcing bar with paint, etc., and the marking used to confirm the screwing depth of the screw reinforcing bar before and after grout material injection. In the embodiment, since the confirmation window 12 is formed and the grout material can be easily removed from the confirmation window 12, the marking becomes unnecessary.

Next, another embodiment of the present invention will be described. In these embodiments, components corresponding to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the second embodiment shown in FIG. 3, only one confirmation window 12 is formed. After the screwing operation of the screw reinforcing bar 1, the cap window 2 is inserted into the confirmation window 12 before the grout material is injected.
Zero is set. The cap 20 is made of an elastic material such as a transparent elastic resin or rubber, and has a slightly larger cross-sectional shape similar to the cross-sectional shape of the confirmation window 12. When the cap 20 is press-fitted into the confirmation window 12, the inner end of the cap 20 is deformed corresponding to the thread of the screw reinforcing bar 1, and the inner end surface thereof is in close contact with the outer peripheral surface of the screw reinforcing bar 1.

The cap 20 can prevent the grout material from leaking from the confirmation window 12 when the grout material is injected. The cap 20 is left as it is fitted in the confirmation window 12. Since the outer periphery of the screw reinforcing bar 1 and the inner end surface of the cap 20 are in close contact with each other, the grout material does not enter between them. It is possible to confirm the screwing depth of the screw reinforcing bar 1.

In the second embodiment, the confirmation window 1 is provided at the center of the joint 10 in order to confirm that the grout material from the injection hole 13 has reached the center of the joint 10.
A small hole 15 (indicated by an imaginary line in FIG. 3) may be formed at a position circumferentially away from 2. The leakage of the grout material from the small holes 15 makes it possible to confirm that the grout material has reached the center of the joint 10.

Instead of the elastic cap 20, a transparent hard resin cap may be used. In this case, a groove that is continuous with the female screw 11 of the joint 10 is formed on the inner surface of the cap (the surface facing the screw reinforcing bar 1). As a material for the cap, a soft (plastic) material may be used instead of the elastic material. Alternatively, the cap may be formed by flowing the melted resin through the confirmation window and curing the resin. When the cap is removed from the confirmation window after grout filling, or when it is not necessary to confirm the screwing depth after application, the cap may be opaque.

In the third embodiment shown in FIGS. 4 and 5, one injection hole 13A is formed in the center of the joint 10.
A longitudinal groove 16 extending in the longitudinal direction is formed on the inner peripheral surface of the joint 10. The center of the vertical groove 16 is located at the injection hole 13A.
And one end thereof extends to an intermediate position between the center of the joint 10 and one end 10a, and the other end extends to an intermediate position between the center of the joint 10 and the other end 10b. Further, two annular grooves 14A are formed on the inner peripheral surface of the joint 10, and these annular grooves 14A are connected to both ends of the vertical groove 16. Further, as shown in FIG. 5, the center of the joint 10 is separated from the injection hole 13A by 90 ° or more in the circumferential direction, and the confirmation window 12 is formed.
Are formed. In the present embodiment, both ends of the vertical groove 16 and the annular groove 14A are located at the center between the end of the confirmation window 12 and the end of the joint 10, respectively.

In the third embodiment, the screw rebar 1
When the grout material is injected from the injection hole 13A after being screwed into the joint 10, the grout material flows toward both ends of the joint 10 along the vertical groove 16, and the annular groove extends from the end of the vertical groove 16 to the annular groove. Flows along 14A. Then, similarly to the first embodiment, the joint 10 is separated into two hands from the annular grooves 14A, respectively, toward the end 10a (10b) and the center of the joint 10, and the joint 10
And the gap between the screw reinforcement 1 is filled. In this embodiment, since the confirmation window 12 is sufficiently far from the injection hole 13A in the circumferential direction, leakage of the grout material at the initial stage of the injection can be suppressed.

In the third embodiment, a cap for closing the confirmation window may be used. As shown in the fourth embodiment in FIG. 6, when the cap 20 is attached to the confirmation window 12,
The confirmation window 12 may be formed near the injection hole 13A.

In the vicinity of the confirmation window 12, the length L of the confirmation window 12
In this case, two marks are formed, and when the tip 1x of the screw reinforcing bar 1 is located at these two marks, it is determined that the screw reinforcing bar 1 is screwed at a required screwing depth. Is also good.

[0025]

As described above, according to the first aspect of the present invention, the filling path of the grout material is divided into two from the injection hole to the end of the joint and from the injection hole to the vicinity of the center of the joint. These paths are shorter than the path from the injection hole formed in the center of the joint to the end of the joint as in the conventional device. Therefore, the injection pressure may be low, and it is possible to use a grout material having a relatively high viscosity. According to the invention of claim 2, the grout material injected into the injection hole once flows into the annular groove, and goes to the end and the center of the joint from the entire circumference of the annular groove, so that the gap between the threaded reinforcing bar and the joint is securely inserted. As the grout material is filled, the injection pressure can be further reduced. According to the invention of claim 3,
Prior to grout material injection, the tip position of the screw rebar can be confirmed from the outside through a confirmation window provided in the joint,
It is possible to easily confirm whether or not the screw rebar is screwed at the required screwing depth. Therefore, it is possible to omit a troublesome operation of previously marking the threaded reinforcing bar for confirming the screwing depth.

According to the invention of claim 4, the grout material injected from the injection hole reaches both ends of the vertical groove along the vertical groove,
Since the grout material is supplied from each end of the longitudinal groove toward the end and the center of the joint, the injection pressure can be reduced, and the range of selection of the grout material can be widened as in the first aspect.
In addition, since the grout material can be injected from one injection hole, workability is good. According to the invention of claim 5, the grout material that has reached both ends of the vertical groove flows into the annular groove, and goes to the end and the center of the joint from the entire circumference of the annular groove, so that the gap between the threaded reinforcing bar and the joint is reliably formed. While filling, the injection pressure can be further reduced. According to the invention of claim 6, since the tip position of the screw reinforcing bar can be externally confirmed through the confirmation window provided in the joint before the grout material injection, the same effect as in claim 3 can be obtained. .
According to the seventh aspect of the present invention, since the cap is attached to the confirmation window, it is possible to prevent the grout material from leaking from the confirmation window when the grout is injected.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a connection device for a screw rebar according to a first embodiment of the present invention, in which (A) shows a state before a screw rebar is screwed to a joint, and (B) shows a joint. Shows a state in which the screw rebar is screwed.

FIGS. 2A and 2B are plan views of the connecting device, wherein FIG. 2A shows a state before a screw rebar is screwed to a joint, and FIG. 2B shows a state in which a screw rebar is screwed to the joint.

FIG. 3 is a longitudinal sectional view of a threaded bar connecting device according to a second embodiment of the present invention, and is a diagram corresponding to FIG. 1 (B).

FIG. 4 is a longitudinal sectional view of a connecting device for a screw rebar according to a third embodiment of the present invention, wherein (A) shows a state before the screw rebar is screwed to the joint, and (B) shows the joint. Shows a state in which the screw rebar is screwed.

FIG. 5 is a cross-sectional view of the joint taken along line VV in FIG.

FIG. 6 is a cross-sectional view of a joint according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Threaded reinforcing bar 1x Tip 10 Joint 10a, 10b End of joint 12 Confirmation window 13, 13A Injection hole 14, 14A Annular groove 16 Vertical groove 20 Cap

Claims (7)

[Claims] 1. A device for connecting threaded steel bars by injecting a grout material with the ends of a pair of threaded steel bars screwed to the joint, wherein the joint has a longitudinal center and one end. Intermediate position with
And an injection hole for injecting a grout material is formed at an intermediate position between the center and the other end, respectively. 2. The coupling device for a screw reinforcing bar according to claim 1, wherein an annular groove connected to the injection hole is formed in an inner peripheral surface of the joint. 3. The connecting device for a screw rebar according to claim 1, wherein a confirmation window for confirming the tips of both screw rebars is formed at the center of the joint. 4. An apparatus for connecting threaded steel bars by injecting a grout material in a state in which ends of a pair of threaded steel bars are screwed to the joint, wherein the joint is provided at a longitudinal center thereof. An injection hole for injecting the grout material is formed, and further, a longitudinal groove extending in the longitudinal direction is formed on the inner peripheral surface of the joint, the center of the longitudinal groove is connected to the injection hole, and one end of the joint is connected to one end of the joint. A coupling device for a threaded reinforcing bar, wherein the coupling device extends to a position intermediate between the center and one end of the joint, and the other end extends to a position intermediate between the center of the joint and the other end of the joint. 5. The threaded rebar according to claim 4, wherein two annular grooves are further formed on the inner peripheral surface of the joint, and these annular grooves are respectively connected to both ends of the vertical groove. Connecting device. 6. The joint according to claim 4, wherein a confirmation window for confirming the tips of both threaded rebars is formed at a position circumferentially distant from the injection hole. Connection device for screw reinforcement. 7. The connection device for a screw reinforcing bar according to claim 3, further comprising a cap for closing the confirmation window when grouting material is injected from the injection hole.