JPH059651B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a steel bar coupler for joining steel bars.

BACKGROUND ART For example, when joining two members made of reinforced concrete, it is necessary to join both the steel rod (so-called reinforcing bar) buried in the concrete and the concrete in order to ensure sufficient strength at the joint. In conventional joining methods, concrete is joined by cast-in-place concrete, and steel bars are joined by overlapping, lap welding, pressure welding, couplers and mortar, couplers and adhesives, etc.

Problems to be Solved by the Invention However, although there is no problem in joining concrete with the above conventional method, it is difficult to perform on-site construction when joining steel bars, and the joint strength is weak. There was a problem. In particular, in the case of PC steel bars that require high joint strength, there are problems in terms of strength, and if both steel bars are thick and are not aligned in a straight line but are inclined to each other, the construction and strength There were problems on both sides.

An object of the present invention is to provide a steel bar coupler that solves the above problems.

Means for Solving the Problems In order to solve the above problems, the steel bar coupler of the present invention connects one of the two male threads cut into the joining side ends of two steel bars to be joined to each other. A nut is screwed into the other male screw, and a cylindrical joint attachment having an annular projection formed at one end of the inner circumferential surface is loosely fitted into the other male thread, and two nuts are screwed into the other male screw by sandwiching the annular projection. The joining side end surfaces of the joining nut and the joining attachment face each other, an annular welding material is fixed to one of the joining side end surfaces, and a cover is fitted to the outer peripheral surface so as to enclose the welding material. It is characterized by the fact that

Function To join steel bars in the above configuration, first,
Loosen the joint nut of one steel bar and the inner nut of the other steel bar, send the joint attachment to the joint nut side by the outer nut, and press the welding material between the end faces of the joint attachment and joint nut on both joint sides. let At this time, a slight gap is left between the annular protrusion of the joining attachment and the steel rod so that the joining attachment can be inclined with respect to the steel rod. next,
Attach electrodes to the joint attachment and joint nut, apply welding current, and weld both joint sides. At this time, the cover prevents the molten welding material from flowing out. After welding, when the joint nut integrated with the joint attachment is tightened, the annular protrusion comes into contact with the inner nut, drawing both steel bars together and applying a suitable tensile force. Finally, the outer nut is tightened to fix the annular protrusion between it and the inner nut, completing the connection.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 3.

In the steel bar coupler 1 of this embodiment, a joining nut 6 is screwed into one of two male threads 4 and 5 carved at the joining side ends of two steel bars 2 and 3 to be joined together. A hollow cylindrical joining attachment is loosely fitted into the other male screw 5, and an annular projection 8 formed at one end of the inner peripheral surface of the joining attachment 7 is held between the inner nut 9 and the outer nut 10. An annular washer 11 having a circular cross section is interposed between the inner nut 9 and the annular projection 8. The joint nut 6 has a male thread 4 in the center.
It is a rod-shaped body with a male thread 12 carved therein, and a mating side end surface 18 faces the mating side end surface 14 of the joining attachment 7. An annular welding material 15 is fixed to the joining side end surface 14 of the joining attachment 7, and a short tubular cover 1 is attached to the outer peripheral surface.
6 is fitted so as to enclose the welding material 15. A conical surface 17 is formed on the surface of the annular projection 8 facing the inner nut 9.

Hereinafter, the function of the above configuration will be explained as follows: Two reinforced concrete panel members 21, 22 formed between three steel frames 18, 19, 20 shown in FIG.
The case of joining will be explained. First, before placing the concrete 23 for the panel, two steel bars 2 and 3 to be reinforcing bars are placed in the steel frames 18, 19, 2.
1, and a steel rod coupler 1 is attached to the joint end of both steel rods 2 and 3 as shown in FIG. Next, as shown in FIG. 2, the joint nut 6 and the inner nut 9 are loosened, the joint attachment 7 is sent out to the joint nut 6 side by the outer nut 10, and the welding material is inserted between the end surfaces 13 and 14 on both joint sides. 15 is squeezed. At that time, a slight gap is left between the annular projection 8 and the washer 11 (not shown) so that the joining attachment 7 can be inclined with respect to the steel rod 3. Next, two electrodes 24 and 25 are attached to the joint nut 6 and the joint attachment 7, and a welding current is applied to both the joint side end surfaces 13 and 1.
Weld 4. At this time, the cover 16 prevents the molten welding material 15 from flowing outside. After welding, when the joint nut 6 integrated with the joint attachment 7 is tightened, the annular protrusion 8 is attached to the washer 1.
The steel rods 2 and 3 are brought into contact with the inner nut 9 through the steel rods 1, and an appropriate tensile force is applied to the steel rods 2 and 3. Next, as shown in FIG. 3, the outer nut 10 is tightened to fix the annular projection 8 between it and the inner nut 9, completing the joining of both steel bars 2 and 3. Finally, as shown in Fig. 4, panel concrete 23 is cast using the steel rods 2 and 3 as reinforcing bars, and joint concrete 26 is cast at the boundary between the two panel members 21 and 22 formed as a result of this. Then, the joining of both panel members 21 and 22 is completed.

In addition, initially, both steel bars 2 and 3 were not supported in a straight line but were tilted to each other, and furthermore, both steel bars 2 and 3
Even if the inclination cannot be corrected due to the thickness of the joint attachment 7, there is a slight gap between the annular protrusion 7 and the washer 11 as described above, and the washer 11 comes into contact with the conical surface 17.
is inclined with respect to the steel bar 3 and is in line with the joining nut 6, so that the steel bars 2, 3 can be joined without any problem.

The above coupler 1 can also be used to connect panels formed by integrating the panel concrete 23 and the steel bars 2 and 3.

Effects of the Invention As described above, according to the present invention, the entire circumference of a steel bar can be reliably welded with one touch even in a narrow place where reinforcing bars are intricate, such as the joint of reinforced concrete members, and the steel bar has a large cross-sectional area. Since the joint is made using a joint nut and a joint attachment, the joint strength is extremely high, and since tensile force can be applied to the steel rod, prestress can be introduced into the concrete as a prestressed steel rod. This has many benefits, such as easy and reliable joining even when there are

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a steel bar coupler showing an embodiment of the present invention, FIGS. 2 and 3 are partial sectional views showing the operation of the present invention, and FIG. 4 is a partial sectional view of a steel bar coupler showing an embodiment of the present invention. It is a partial sectional view showing an example. DESCRIPTION OF SYMBOLS 1... Steel bar coupler, 2... Steel rod, 3... Steel bar, 4... Male thread, 5... Male thread, 6... Connection nut, 7... Connection attachment, 8... Annular projection, 9... Inner Natsuto, 10... Outer Natsuto, 11...
... Washer, 13 ... Joining side end surface, 14 ... Joining side end surface, 15 ... Welding material, 16 ... Cover.

Claims (1)

[Claims] 1. A joining nut is screwed into one of the two male threads carved on the joining side ends of two steel bars to be joined together, and the other male thread has an annular projection at one end of its inner peripheral surface. The formed cylindrical joint attachment is loosely fitted, and two nuts, an inner and an outer one, are screwed in between the annular protrusion, and the joint side end surfaces of the joint nut and the joint attachment are opposed to each other, and either joint A steel bar coupler, characterized in that an annular welding material is fixed to a side end face, and a cover is fitted to an outer peripheral surface so as to enclose the welding material.