JPH11347794A - Method of welding backing and reinforcing bar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain backing requiring no support by providing a welding space, fitting to the joint of a reinforcing bar arranged oppositely, and equalizing the height of the oppositely facing plane that is in line contact with the reinforcing bar to nearly the height of the reinforcing bar. SOLUTION: A backing 1 is fitted to the joint 2a, 3a of the reinforcing bars 2, 3 oppositely arranged with a welding space W provided, welding is performed by inserting a welding rod 5 from the opening of the backing 1 to the welding space W, and a part of the backing 1 is melted and integrated with the reinforcing bars 2, 3. A molten metal 8 flows through a gap 6 formed between the bottom face of the reinforcing bars 2, 3 and the backing 1, and welds them firmly. By inserting a wire 7 into the gap 6 or illuminating the gap 6 with a penlight, it can be easily confirmed whether or not the molten metal 8 is spread for sure welding. Since the oppositely facing plane of the backing 1 is nearly as high as the reinforcing bars 2, 3, the molten metal 8 is prevented from overflowing. The backing 1 is machined such that a steel sheet is bent roughly in U-shape with the lower part bent in V-shape and that, from its tip ends, the opposing planes are continuously formed with a space apart nearly in the diameter of the reinforcing bars 2, 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint for welding a reinforcing steel bar to be joined which is provided opposite to each other with a welding interval therebetween so that a molten metal does not flow or melt off. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backing metal that is made, and a method for joining rebars that performs welding using the backing metal without causing welding defects.

[0002]

2. Description of the Related Art FIGS. 14 and 15 are views for explaining a conventional method of joining reinforcing bars using a backing metal.
As shown in FIG. 16, a steel plate is formed by bending an iron plate into a semicircular shape, a half of a pipe, or FIGS.
As shown in FIG. 8, there is a pipe provided with an opening 101a. The material of the backing metal 101 is steel, copper, ceramic, or the like, which is welded by gas pressure welding, a weld joint, a mechanical joint, or the like, and is removed after welding except for steel.

[0003] Next, a method of joining reinforcing bars will be described. First,
The backing metal 101 is fitted to the joint portions 102a, 103a of the reinforcing bars 102, 103 to be joined which are disposed opposite to each other with a welding interval W, and the backing metal 101 is supported by a jig (not shown). From the opening 101a of the backing metal 101 to the welding rod 104
Is inserted, and the rebars 102 and 103 to be joined together with the welding rod 104 are melted and welded within the welding interval W.

[0004]

The conventional method of joining a backing metal and a reinforcing bar is constituted as described above, and therefore has the following problems.

A) Since the backing metal is semicircular, as shown in FIG. 15, if the welding penetration of the reinforcing steel is shallow, the bottom of the reinforcing steel and the backing metal may become non-welded 105, and
This non-weld 105 cannot be found. Therefore, Patent 26
As described in JP-A No. 13535, a groove is formed on the inner surface of the backing metal in consideration of welding penetration, that is, a facing portion of the welding interval W, and as shown in FIGS. And a number of holes or slits 106 in the backing metal.
Is provided.

On the other hand, if a copper material is used for the backing metal 101, the copper material can be removed after the welding is completed, and the appearance of the joint can be inspected, but the backing metal 101 is severely damaged. There is a disadvantage that consumption of expensive copper increases. Therefore, ceramic is used as the material of the backing metal 101, and after the completion of welding, the backing metal 1 of the ceramic is used.
Although there is a method in which 01 is crushed and removed, work that is completely different from welding called crushing is required.

B) Since the backing metal is semicircular, as shown in FIG. 15, the molten metal 107 runs off the outside of the backing metal at the welded top, resulting in a sag 107a of the molten metal 107.

C) It is impossible to visually confirm the poor penetration of the weld bottom (root portion), that is, the occurrence of the unwelded portion 105.

D) Since the backing metal is semicircular, it is difficult to inspect the non-weld 105 by ultrasonic inspection.

E) In order to fix the rebar and the rebar, it is necessary to perform tack welding, but the rebar has a high carbon equivalent,
Due to the brittleness, tack welding is prohibited. However, if it is unavoidable to perform tack welding, it is necessary to take appropriate measures such as preheating and post-heating at an appropriate position. However, according to the conventional method, tack welding is performed at an arbitrary location by an arbitrary method, so that the temporary welding location is damaged, resulting in a very dangerous state.

F) At the time of welding, a jig for supporting the backing metal is required.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a shape which is easy to process and is fitted to a joint portion of a reinforcing bar to be joined which is provided opposite to each other with a welding interval therebetween. It is intended to provide a backing metal that does not require a special support jig. Also. It is an object of the present invention to provide a joining method capable of securely and firmly welding rebars using the backing metal.

[0013]

A backing metal according to the present invention is a backing metal which is fitted to a joint portion of a reinforcing steel bar to be joined which is provided oppositely with a welding interval and receives a molten metal. And the height of the opposed plane is substantially the same as that of the reinforcing bar.

In the backing metal according to the present invention, a locking portion facing the inner surface of the end of the facing plane is provided in the axial direction of the reinforcing bar.

The backing metal according to the present invention has a thermochromic member provided on an outer surface corresponding to a welding interval of a reinforcing bar.

The backing metal according to the present invention is composed of two substantially V-shaped planes formed on the plumb line of the reinforcing bar so as to form a gap between the reinforcing bar and an opposing flat surface continuous with the flat surface. It is composed.

According to a method of joining a reinforcing bar according to the present invention, a backing plate having an opposing flat surface which is in line contact with the reinforcing bar and having the height of the opposing flat surface substantially equal to that of the reinforcing bar is used. It is fitted to the joint portion of the reinforcing steel bar to be joined which is provided opposite to each other with a welding interval, and a welding rod is inserted into the welding interval from the opening of the backing metal and welded, and a part of the backing metal is melted. Then, it is integrated with the rebar.

According to a method of joining a reinforcing bar according to the present invention, there is provided an opposing flat surface which is in line contact with the reinforcing bar, the height of the opposing flat surface is substantially the same as that of the reinforcing bar, and the end face of the opposing flat surface faces the inner surface. Using a backing metal provided with a stop portion in the axial direction of the reinforcing bar, the backing metal is fitted to a joint portion of a reinforcing bar to be joined which is disposed opposite to each other with a welding interval, and each of the reinforcing bars to be joined is attached. After being locked and positioned by the locking portion and temporarily welding at the position of the locking portion, a welding rod is inserted into the welding interval from the opening of the backing plate and welded, thereby welding the backing plate. The part is melted and integrated with the reinforcing bar.

The method of joining reinforcing bars according to the present invention uses a backing metal provided with a thermochromic member on the outer surface corresponding to the welding interval of the reinforcing bars, and judges the welding state based on the color change of the thermochromic member.

[0020]

An embodiment of the present invention will be described below with reference to the accompanying drawings. Embodiment 1 FIG. 1 is a plan view showing a backing metal according to Embodiment 1 of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a longitudinal sectional view taken along line 3-3 in FIG. The backing metal 1 is formed by bending a steel plate to form a gap 6 on a vertical line of a reinforcing bar.
The two planes 1a, 1b are formed in a substantially V shape, and the two planes 1a, 1b are formed with the opposing planes 1c, 1d continuously. The height of the opposing planes 1c, 1d is substantially equal to the height of the rebar. They are the same height.

Next, the welding operation using the backing metal 1 will be described. First, the backing metal 1 is fitted to the joints 2a, 3a of the reinforcing steel bars 2, 3 to be joined which are opposed to each other with a welding space W therebetween. Then, a welding rod 5 is inserted and welded, and a part of the backing metal 1 is melted together with the welding rod 5 to be integrated with the rebar.

As described above, according to the first embodiment, since the rebars 2, 3 and the backing metal 1 are in line contact, a gap 6 is provided between the bottom surfaces of the rebars 2, 3 and the backing metal 1. Is formed, and the molten metal 8 flows in the axial direction of the rebars 2 and 3 through the gap 6 so that the entirety of the molten metal can be strongly welded. As shown in FIG. 5, a wire 7 is inserted into the gap 6 or the gap 6 is illuminated with a penlight to form a molten metal 8.
Can be easily and reliably checked between the rebars 2 and 3 and the backing metal 1 to check whether welding is being performed reliably. In addition, since the opposing flat surfaces 1c and 1d of the backing metal 1 are substantially the same height as the reinforcing bars 2 and 3, there is no possibility that the molten metal 8 overflows to the outside of the backing metal 1.

Embodiment 2 FIG. 6 is a plan view showing a backing plate according to Embodiment 2 of the present invention, FIG. 7 is a side view thereof, and FIG. 8 is a longitudinal sectional view taken along line 8-8 in FIG. . Similar to the first embodiment, this backing metal 1 is formed by bending a steel plate and forming two substantially flat V-shaped flat surfaces 1a so as to form a gap between the reinforcing bar and the reinforcing bar on the vertical line of the reinforcing bar. , 1b and opposing flat surfaces 1c, 1d continuous with the flat surfaces 1a, 1b, and engaging portions 9, 10 opposing the inner surfaces of the ends of the opposing flat surfaces 1c, 1d are arranged in the axial direction of the reinforcing bar. Two pairs are provided, and the heights of the opposing flat surfaces 1c and 1d which are in line contact with the reinforcing bars 2 and 3 are substantially the same as the above-mentioned reinforcing bars. The locking portions 9 and 10 may be formed by punching or cutting and raising the backing metal 1 itself, although a separate member may be attached. In the illustrated example, the opposing plane 1 is shown.
Although two pairs of locking portions 9 and 10 are separately formed in c and 1d corresponding to the rebars 2 and 3, however, the pair may be formed longer in the axial direction of the rebars 2 and 3.

Next, a welding operation using the backing metal 1 will be described. First, the backing metal is fitted to the joints 2a and 3a of the reinforcing bars 2 and 3 to be joined, which are arranged to face each other with a welding interval. In this case, since the reinforcing bar has a circular cross-sectional shape, its peripheral surface serves as a guide surface, and passes through the locking portions 9 and 10 while pushing the opposing flat surfaces 1c and 1d of the backing metal 1 outward and opening the same. It is stored in the money. In this state, since both rebars are locked and stopped by the locking portions 9, 10 by restoring the opposing planes 1c, 1d, they are positioned as shown in FIGS.
As shown in FIG. 1, after the tack welding 12 is performed at the positions of the locking portions 9 and 10, the welding rod 5 is inserted into the welding interval W from the opening 4 of the backing metal 1 and welded. 5 and a part of the backing metal 1 is melted and integrated with the reinforcing bars 2 and 3.

As described above, according to the second embodiment, the backing metal 1 has the locking portions 9, 10 facing the inner surfaces of the ends of the opposing flat surfaces 1 c, 1 d in the axial direction of the reinforcing bars 2, 3. Since the reinforcing bars 2 and 3 are locked and held by the locking portions 9 and 10, a jig for supporting the backing metal 1 becomes unnecessary, and workability is improved. Further, since the backing metal 1 is in line contact with the reinforcing bars 2 and 3, a gap 6 is formed between the two, and the molten metal flows in the axial direction of the reinforcing bars 2 and 3 through the gap 6 to solidify the whole. Can be welded. Further, by inserting the wire 7 into the gap 6, the molten metal spreads over the entire circumference of both rebars, and it is possible to easily and reliably know that welding is being performed reliably. Moreover, since the backing metal 1 has a depth enough to accommodate the reinforcing steel, there is no possibility that the molten metal 8 overflows to the outside of the backing metal 1.

Third Embodiment FIGS. 12 and 13 are cross-sectional views showing a backing plate according to a third embodiment of the present invention, in which the welding interval W between the joints 2a and 3a of the reinforcing steel bars 2 and 3 to be joined is shown. A thermochromic member such as paint 11 is applied to the corresponding outer surface.

Next, the welding operation using the backing metal 1 will be described. The backing metal 1 is fitted to the joints 2a, 3a of the reinforcing steel bars 2, 3 to be joined, which are disposed to face each other with a welding interval W therebetween,
A welding rod 5 is inserted into the welding interval W from the opening 4 of the backing metal 1 and welded, and a part of the backing metal 1 is melted together with the welding rod 5 to be integrated with the rebar. During this welding,
The portion of the backing metal 1 corresponding to the welding interval W is heated most, and the thermochromic member 11 provided on its outer surface is discolored, and the welding state can be known from the discolored state.

As described above, according to the third embodiment, the thermochromic member 11 is provided at the portion of the backing metal 1 facing the welding interval W. Can be known very easily, and welding defects can be reliably eliminated.

In each of the above embodiments, the backing money 1
Is formed by four planes, but if it has a U-shaped cross section composed of three orthogonal planes, and a shape that is in line contact with a reinforcing bar having a circular cross section, it is a polygonal cross section composed of a large number of planes. It may be.

[0030]

As described above, according to the present invention, the backing metal is provided so as to have the opposing plane which is in line contact with the reinforcing bar, and the height of the opposing plane is substantially the same as the reinforcing bar. A gap is formed between the reinforcing bar and the backing metal by line contact, and through this gap, the molten metal flows also in the axial direction of the reinforcing bar, so that the entirety can be firmly welded. In addition, by inserting a wire into this gap or illuminating the gap with a penlight, it is possible to easily and reliably check whether the molten metal has spread between both rebars and the backing metal. . In addition, since the opposing plane of the backing metal is substantially the same height as the reinforcing bar, there is an effect that the molten metal does not overflow to the outside of the backing metal.

Further, according to the present invention, the backing bar is provided with the locking portion facing the inner surface of the end of the facing plane in the axial direction of the reinforcing bar, so that the reinforcing bar is locked and held by the locking portion. can do. As a result, a jig for supporting the backing metal is not required, workability is improved, welding can be performed firmly, and effects such as checking the welding state and preventing molten metal from overflowing can be obtained. .

Further, according to the present invention, since the backing metal is provided with the thermal discoloration member provided on the outer surface corresponding to the welding interval of the reinforcing bar, the welding state can be known very easily by observing the discolored state. Therefore, an effect of reliably eliminating welding defects can be obtained.

Further, according to the present invention, the backing metal is formed by bending an iron plate so as to form two substantially flat V-shapes on a vertical line of the reinforcing bar so as to form a gap between the reinforcing bar and the reinforcing bar. Since it is constituted by the opposing flat surface which is continuous with this flat surface, it is easy to manufacture since it has a simple shape, and the effect that the welding operation is easy can be obtained.

Further, according to the present invention, a backing plate having an opposing flat surface which is in line contact with the reinforcing bar and having a height of the opposing flat surface substantially equal to that of the reinforcing bar is used, and this backing plate is welded at a welding interval. To be fitted to the joint of the reinforcing steel bar
Welding is performed by inserting a welding rod into the welding interval from the opening of the backing metal and welding, so that a part of the backing metal is melted and integrated with the rebar, so that non-welding does not occur.
There is an effect that can be welded firmly.

Further, according to the present invention, there is provided an opposing flat surface which is in line contact with the reinforcing bar, the height of the opposing flat surface is substantially the same as that of the reinforcing bar, and the engaging portion opposing the inner surface of the end of the opposing flat surface. Using a backing metal provided in the axial direction of the reinforcing bar, the backing metal is fitted to a joint portion of a reinforcing bar to be joined opposed to each other with a welding interval, and each of the reinforcing bars to be joined is connected to the above After being locked and stopped at the stop portion and temporarily welding at this stop portion position, a welding rod is inserted into the welding interval from the opening of the backing plate and welded, and a part of the backing plate is removed. Since it is configured to be melted and integrated with the rebar, the tack welding position can be specified, the quality of tack welding can be easily determined, and the occurrence of damage from the tack welding position can be reduced. Welding work without using a jig to support the backing metal. Reduction is, without causing non-welded,
There is an effect that can be welded firmly.

Further, according to the present invention, since the backing metal provided with the thermochromic member on the outer surface corresponding to the welding interval of the reinforcing bar is used, the discoloration state of the thermochromic member can be checked during welding. In addition, it is possible to know the welding state very easily, and to obtain an effect that welding can be reliably performed without causing welding defects.

[Brief description of the drawings]

FIG. 1 is a plan view showing a backing metal according to Embodiment 1 of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a longitudinal sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a diagram illustrating a method of joining reinforcing bars using the backing metal according to the first embodiment.

FIG. 5 is a transverse sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is a plan view showing a backing metal according to Embodiment 2 of the present invention.

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a longitudinal sectional view taken along line 8-8 in FIG. 7;

FIG. 9 is a plan view showing a state where a reinforcing bar is tack-welded to the backing metal according to the second embodiment.

FIG. 10 is a plan view showing a state where the transition from the tack welding of FIG. 9 to the joining of a reinforcing bar is performed.

11 is a longitudinal sectional view of FIG.

FIG. 12 is a side view showing a backing metal according to Embodiment 3 of the present invention.

13 is a longitudinal sectional view showing a state where welding is performed using the backing metal shown in FIG. 12;

FIG. 14 is an explanatory diagram of a welding state using a conventional backing metal.

FIG. 15 is a longitudinal sectional view taken along line 15-15 of FIG. 14;

FIG. 16 is an explanatory view showing a conventional backing metal.

FIG. 17 is an explanatory view showing another conventional backing metal.

18 is a longitudinal sectional view of FIG.

FIG. 19 is an explanatory view showing still another conventional backing metal.

20 is a longitudinal sectional view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Backing metal 2 Rebar 3 Rebar 4 Opening 5 Welding rod 6 Gap 7 Wire 8 Molten metal 9 Locking part 10 Locking part 11 Paint (thermal discoloration member)

Continuation of the front page (71) Applicant 598072146 Kudo Kogyo Co., Ltd. 2-8-4 Kasuganaka, Konohana-ku, Osaka-shi (71) Applicant 598072157 Taiyo Welding Co., Ltd. Applicant 598072168 Kansai Press Co., Ltd. 4-10-16 Kanaoka, Higashiosaka City (72) Inventor Motoomi Ogata 1413-2 Kamiyari, Matsudo City, Chiba Prefecture (72) Inventor Eiji Suzuki 129-9, Komagaki, Nagareyama City, Chiba Prefecture (72) Inventor Toru Kurisu 2-4-40 Umeda, Kita-ku, Osaka Nishi-Umeda Watanabe Building East Asia Pressure Welding Co., Ltd. (72) Inventor Bunichi Mitani 1-2-1, Sanbancho, Nagata-ku, Kobe City Inside (72) Inventor Yoshio Kudo 2-8-4 Kasuganaka, Konohana-ku, Osaka-shi Inside Kudo Industrial Co., Ltd. (72) Inventor Koichi Adachi 3-8-6 Minamikagaya, Suminoe-ku, Osaka Taiyo Welding Corporation (72) Inventor Shigeaki Miyata 4-10-16 Kanaoka, Higashiosaka

Claims (7)

[Claims] 1. A backing metal, which is fitted to a joint portion of a reinforcing bar to be joined and provided with a welding interval therebetween and receives a molten metal, has an opposing flat surface in line contact with the reinforcing bar, and the opposing flat surface. A backing metal having a height substantially equal to the height of the rebar. 2. The backing metal according to claim 1, wherein a locking portion facing the inner surface of the end of the facing plane is provided in the axial direction of the reinforcing bar. 3. The backing metal according to claim 1, wherein a thermochromic member is provided on an outer surface corresponding to a welding interval of the reinforcing bar. 4. It is characterized in that it is formed by two substantially V-shaped planes formed on a vertical line of the reinforcing bar so as to form a gap between the reinforcing bar and an opposing plane continuous with the plane. The backing money according to claim 1 or 2. 5. A backing plate having an opposing flat surface in line contact with a reinforcing bar, and having a height of the opposing flat surface substantially equal to the height of the reinforcing bar, and arranging the backing plates facing each other with a welding interval. The welding rod was inserted into the welding interval from the opening of the backing metal and welded, and a part of the backing metal was melted and integrated with the reinforcing steel. A method for joining reinforcing bars, characterized in that: 6. An opposing plane that is in line contact with the reinforcing bar, the height of the opposing plane is substantially the same as that of the reinforcing bar, and a locking portion that faces the inner surface of the end of the opposing plane is located in the axial direction of the reinforcing bar. Using the provided backing metal, the backing metal is fitted to the joint portion of the reinforcing bar to be joined, which is provided oppositely with a welding interval, and each of the reinforcing bars to be joined is locked by the locking portion. After welding by tacking at the position of the locking portion, a welding rod is inserted into the welding interval from the opening of the backing metal and welded, and a part of the backing metal is melted to form the reinforcing bar. A method for joining reinforcing bars, which is integrated. 7. The welding state is determined based on the discoloration of the thermochromic member using a backing metal provided with a thermochromic member on the outer surface corresponding to the welding interval of the reinforcing bars. The joining method of the rebar according to the description.