JP2000153397A - Arc welding jig for cruciform joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a weld zone having a large leg length in a short time by preventing dropping down of a molten metal when a cruciform joint of bar steel is welded. SOLUTION: When a cruciform joint of reinforcing bars 7, 9 is arc welded, second holding surfaces 5 of two arc welding jigs 1 are faced each other, the main reinforcing bar is held with the second holding surfaces 5, two arc welding jigs 1 are fixed with a fixture, and a guide groove 8 having a fixed width is formed on the upper surface of the main reinforcing bar 7 with the side surfaces 4 of each arc welding jig 1. The orthogonal reinforcing bar 9 is placed on a first holding surface 3 of two arc welding jigs 1, fixed with a pressing jig and crossed with the main reinforcing bar 7. In such a state, arc welding is executed using the side surfaces forming the guide groove 8 on the upper surface of the main reinforcing bar 7 as a guide surface for head and tail ends of the weld zone, and whereby the crossing part between the main reinforcing bar 7 and the orthogonal reinforcing bar 9 is joined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for arc welding of a cruciform joint, for example, in which a steel bar such as a reinforcing bar is crossed and welded at the intersection.

In recent years, as the size of a reinforced concrete structure has increased, the structural strength of the reinforced concrete has been increased by using a reinforcing bar lattice in which high-strength, large-diameter deformed steel bars are joined in a lattice shape. When fabricating this reinforcing bar grid, the intersections of the reinforcing bars should be fixed with wires, and the intersections should be arced to increase the strength of the structure from the viewpoint of improving the seismic performance.
A welding method using a resistance welding method such as a black welding method, an upset butt welding method, or a flash butt welding method is employed. As the arc welding method, coating arc, gas shield arc welding, or the like is applied, and is a method of welding while filling a molten metal in a cross intersection. In recent years, gas shielded arc welding equipment has been replaced with robot arcs.
Or automatic welding. The upset butt welding method is a method in which electric current is applied to a joint of a crossed steel bar under pressure to generate Joule heat at the joint, and when the temperature reaches a temperature at which joining can be performed, the joint is melted and pressed. In the flash butt welding method, an electric current is applied to a pair of crossed steel bars to be joined, a short circuit and an electric discharge are alternately repeated at the joining point to heat the joint, and when the temperature reaches a temperature at which joining is possible, pressurization is performed. It is a joining method.

[0003] Resistance welding by upset butt welding or flash butt welding can be joined in a short time, but since no filler metal (welding wire) is used, it is difficult to increase the cross-sectional area of the joint and the strength of the weld joint. Is difficult to raise. On the other hand, the arc welding method uses a filler metal,
The vertical leg length of the weld can be increased, and the cross-sectional area of the joint can be increased to improve the joint strength.

[0004]

However, as shown in FIG. 4, in arc welding of a reinforcing steel cruciform joint in which the main reinforcement 7 and the orthogonal reinforcement 9 intersect, the molten metal 12 is placed on the thin cylindrical main reinforcement 7. In order to form, the molten metal 12 is
, And it was difficult to form a weld with a large leg length in one pass. Therefore, when forming a weld with a large leg length at the joint of a reinforced cruciform joint by arc welding, a small weld bead is formed and solidified to prevent the molten metal from dripping, and the weld bead is successively piled on it. The method of stacking is repeated. Therefore, much time is required for the welding operation.

[0005] When a small weld bead is stacked to form a fillet weld, the reinforced cross joint is welded using an automatic arc welding machine because the weld is susceptible to a minute change in shape. In this case, the movement of the welding torch had to be changed depending on whether or not a joint was present at the joint and the size of the gap between the main and orthogonal bars, and the welding operation was not easy.

An object of the present invention is to provide a jig for arc welding of a cruciform joint which can improve the disadvantages and prevent the molten metal from dripping and can form a weld having a large leg length in a short time. Is what you do.

[0007]

A jig for arc welding of a cruciform joint according to the present invention is a jig for arc welding of a cruciform joint for crossing a steel bar in a cross shape and welding an intersection thereof. Has a first holding surface that is formed in a semi-cylindrical shape at the center of the upper surface of the roof mold that is inclined to hold one of the steel bars,
It is provided at the lower part of one side surface orthogonal to the first holding surface,
A first holding surface is formed in a semi-cylindrical shape perpendicular to the axial direction of the first holding surface, has a second holding surface for holding the other steel bar, and an upper part of the side surface provided with the second holding surface is welded. The guide surface is provided at the start and end of.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An arc welding jig according to the present invention comprises:
A semi-cylindrical first formed of copper or ceramics and formed horizontally at the center of the upper surface that protrudes at the upper end and slopes left and right.
The first holding surface has a 90 ° difference in axis direction from the axis direction of the first holding surface at a lower portion of the first holding surface on one side surface orthogonal to the axis of the first holding surface. And a lower end portion of the second holding surface is formed to project from the side surface of the upper end portion by a predetermined length.

When arc welding a cross joint of a reinforcing bar,
The two holding surfaces of the two arc welding jigs are opposed to each other, the main reinforcement is sandwiched between the second holding surfaces, and the two arc welding jigs are fixed with the fixtures. A guide groove having a constant width is formed on the upper surface of the main bar. Next, orthogonal streaks are placed on the first holding surfaces of the two arc welding jigs, fixed with a holding jig, and crossed with the main streaks. In this state, arc welding is performed on the side surface on which the guide groove is formed on the upper surface of the main bar as the guide surface at the start and end of the welded portion to join the intersection of the main bar and the orthogonal bar.

[0010]

FIG. 1 is a perspective view showing an arc welding jig according to an embodiment of the present invention. As shown in the figure, the arc welding jig 1 is a jig for welding a cross joint of a reinforcing bar,
A semi-cylindrical first holding surface 3 made of copper or ceramic and formed horizontally at the center of upper surfaces 2a and 2b projecting upward and inclined right and left and having a radius corresponding to the outer diameter of a reinforcing bar to be held. In the lower side of the first holding surface 3 on one side surface 4 orthogonal to the axis of the first holding surface 3, the axis direction of the first holding surface is different from the axis direction by 90 degrees and horizontally. It has a semi-cylindrical second holding surface 5 having a radius corresponding to the outer diameter of the reinforcing bar to be formed and held, and the lower end 6 of the second holding surface 5 has a fixed length L longer than the side surface 4 of the upper end. Only protruding.

An arc welding jig 1 constructed as described above.
When performing arc welding of a cruciform joint of a reinforcing bar using the above, the second holding surfaces 5 of the two arc welding jigs 1 face each other as shown in FIG. The two jigs for arc welding 1 are fixed with fixtures with the main bar 7 interposed therebetween. As described above, the main reinforcing bar 7 is sandwiched and fixed between the second holding surfaces 5 of the two arc welding jigs 1, so that the side surface 4 of each arc welding jig 1 guides a predetermined width to the upper surface of the main reinforcing bar 7. The groove 8 can be formed. The welding length is determined by the width of the guide groove 8, and the size thereof is set to 30 to 70% of the maximum diameter of the main bar 7. Next, the orthogonal streaks 9 are placed on the first holding surfaces 3 of the two arc welding jigs 1, fixed with a holding jig, and crossed with the main streaks 7.

In this state, the intersection of the main bar 7 and the orthogonal bar 9 is arc welded using an automatic arc welding machine. When performing the arc welding, the side surface 4 on which the guide groove 8 on the upper surface of the main reinforcement 7 is formed is used as the guide surface at the start and end of the welded portion. Even when a large molten pool is formed by arc welding the side surface 4 on which the guide groove 8 is formed as the guide surface at the start and end of the welded portion while sandwiching the both side surfaces of the main reinforcement 7 with the second holding surface 5 in this manner. ,
Since the molten metal can be prevented from dripping on both side surfaces of the main bar 7 and welding can be performed using a high welding current, the feeding speed of the welding wire can be increased, and welding can be performed in a short time. And a weld with a large leg length can be obtained.

When the main reinforcement 7 and the orthogonal reinforcement 9 are arc-welded, the upper surfaces 2a and 2b of the jig 1 for arc welding are inclined right and left, and the height of the side surface 4 forming the guide groove 8 is increased by the orthogonal reinforcement. 9
As the distance increases, the welding torch 10 does not come into contact with the upper surface 2a of the jig 1 for arc welding, as shown in FIG. The projection length (extension) of the welding wire 11 can always be maintained at a predetermined length, for example, 20 to 30 mm, and stable welding can be performed. Here, if the height of the side surface 4 forming the guide groove 8 is too high, the extension becomes longer during welding of the root portion, and thus the height is 2 to 2 times longer than the target leg length.
It is desirable that the height is about 5 mm higher.

Further, by forming the jig 1 for arc welding with copper or ceramics, it is possible to prevent the molten metal from burning on the jig 1 for arc welding. The jig 1 can be easily removed.

In the above embodiment, two arc welding jigs 1 are used to perform arc welding of the main reinforcing bar 7 and the orthogonal bar 9. However, after welding, the arc welding jig 1 is left without being removed. In this case, the two arc welding jigs 1 may be integrally formed. In this case, the jig for arc welding may be formed of the same material as the rebar or mild steel.

[0016]

As described above, according to the present invention, the both sides of the lower bar of the cross bar of the cross bar are sandwiched between the second holding surfaces of the jig for arc welding, and the width of the bar is fixed to the upper surface of the bar. Even if a large molten pool is formed, the side surfaces of the arc welding jig with the formed guide grooves are arc-welded as the guide surface at the beginning and end of the welded part, so that both sides of the steel bar can be melted. Can prevent the metal from dripping,
A weld with a large leg length can be formed in one pass.

Further, by preventing the molten metal from dripping on both sides of the lower steel bar crossing the cross, welding can be performed using a high welding current, so that the feeding speed of the welding wire can be increased. Can be welded in a short time.

Further, when arc welding a cross bar of a steel bar, the upper surface of the arc welding jig is inclined to the left and right in a roof shape, and the height of the side surface forming the guide groove is set apart from the upper steel bar. Therefore, since the length is reduced, the protrusion length of the welding wire can be always maintained at a predetermined length, and stable welding can be performed.

Further, since a large weld pool is formed in one pass by using a high welding current, when welding a reinforcing steel cruciform joint using an automatic arc welding machine, the condition of the joints of the reinforcing steel and the gaps between the reinforcing steels are reduced. There is no need to consider the situation, welding can be performed with the same welding program, and the efficiency of the welding operation can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an arc welding jig according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a state when welding a reinforcing steel cruciform joint according to the embodiment.

FIG. 3 is a side sectional view showing a welding state.

FIG. 4 is a perspective view showing a reinforced cross joint.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 arc welding jig 2 upper surface 3 first holding surface 4 side surface 5 second holding surface 7 main bar 9 orthogonal bar

Claims (1)

[Claims] 1. An arc welding jig for a cruciform joint in which a steel bar is crossed in a cross shape and the intersection is welded, wherein the jig is formed in a semi-cylindrical shape at the center of the upper surface of a roof mold inclined left and right. A first holding surface for holding one of the steel bars;
Is provided at a lower portion of one side surface orthogonal to the holding surface of the
A second holding surface which is formed in a semi-cylindrical shape perpendicular to the axial direction of the holding surface and holds the other steel bar; An arc welding jig for a cruciform joint, wherein the jig is used as an end guide surface.