JPH0557439A - Initial/terminal processing method for consumable electrode welding - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the formation of protrusions at the beginning and end of consumable electrode welding and the occurrence of welding defects. [Structure] At the welding start end, relative movement between the welding device and the welding member is started with the torch being rotated so that the two wires overlap in the welding direction, and then one wire is inserted and withdrawn to perform welding. When starting, the torch is reciprocally rotated at a required rotation angle to form the narrow width start end weld portion 21, and then, when the welding pool becomes stable, the torch is rotated by 90 ° from the state where the wires are overlapped in the welding direction and fixed. At the same time, the other wire also forms a wide steady welding portion 22 by changing the phase with respect to the one wire and moving in and out, and at the welding end portion, increases the relative movement speed between the welding device and the welding member. Then, the high-speed termination welding portion 23 is formed by increasing the moving speed of the two wires.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating the beginning and end of consumable electrode welding.

[0002]

2. Description of the Related Art In a consumable electrode welding method, the wire itself is one electrode, and an arc is generated between the welding member and the wire by projecting the wire toward the welding member which is the other electrode. Welding is performed by heating and melting the wire, and the wire consumed by the melting is fed. The consumable electrode welding method is excellent in that it can perform extremely high-efficiency welding, and various conventional methods have been proposed in which two wires can be put in and out so that more efficient welding can be performed. There is.

FIGS. 7 to 9 show an example of a conventional method in which the second layer bead 4 is welded to the upper layer of the first layer bead 3 by consumable electrode welding while feeding the two wires 1 and 2. In order to improve the welding efficiency, either the welding device or the welding member 6 that feeds the wires 1 and 2 in a state in which the two wires 1 and 2 are positioned side by side in a direction perpendicular to the welding direction 5. One of them is moved so that the welding member 6 is welded all at once from the beginning to the end.

[0004]

However, the above-mentioned conventional consumable electrode welding method has a problem that welding defects are likely to occur at the start and end portions of the welding bead.

That is, as shown in FIGS. 7 and 8, when the consumable electrode welding is started, the temperature of the welding member 6 is still low. Therefore, even if the wires 1 and 2 are melted, a molten pool cannot be formed and immediately solidifies. As a result, a large raised protrusion 8 is formed at the welding start end portion 7, and the protrusion 8 has poor adhesion to the bead 3 of the first layer, and the formation of the protrusion 8 causes a recess. Therefore, when the bead of the next layer is further formed on the welding start end portion 7, there is a problem that a welding defect occurs inside. For this reason, conventionally, the protruding portion 8 of the welding start end portion 7 is cut by a grinder or the like to form a bead of the next layer, but this work is extremely difficult and Because it becomes impossible to perform continuous welding work,
There was a problem that high efficiency, which is an advantage of consumable electrode welding, could not be achieved.

At the end of the consumable electrode welding, as shown in FIG. 9, the welding end portion 10 is lapped on the welding start end portion 7 of the second layer to end the welding. Welding end portion 10 having the same thickness as the bead 4 of the layer
Is to be formed on the welding start end portion 7,
There is a problem in that the welding end portion 10 becomes the protruding portion 11 that largely protrudes, and for this reason, the protruding portion 11 needs to be cut by manual work or the like.

The present invention has been made in view of the above-mentioned conventional problems, and it is possible to prevent a welding defect from being generated at the beginning and the end due to consumable electrode welding, and to prevent a protrusion from being formed. It is an object of the present invention to provide a method for treating start and end of consumable electrode welding.

[0008]

SUMMARY OF THE INVENTION The present invention is a welding start and end treatment method for performing consumable electrode welding by a welding device equipped with a torch that can guide and rotate two wires that can be moved in and out separately. At the welding start end, relative movement between the welding device and the welding member is started in a state where the torch is rotated so that the two wires are overlapped in the welding direction, and then welding is performed by moving one wire in and out. A state in which the torch is overlapped in the welding direction when a narrow start welding portion is formed by starting and reciprocating the torch at a required rotation angle and then the welding pool is stably formed. Form a wide steady welded part by fixing it in a state of being rotated by 90 ° from the other wire and moving the other wire into and out of the one wire while changing its phase.
At the welding end portion, the relative movement speed of the welding device and the welding member is increased, and at the same time, the moving speed of the two wires is increased to form a high temperature end welding portion. The present invention relates to an end treatment method.

[0009]

At the welding start end, the torch is rotated so that the two wires are overlapped in the welding direction.
First, the relative movement between the welding device and the welding member is started, and then the welding is started by moving in and out one of the wires, and the torch is reciprocally rotated at a required rotation angle to form the narrow-width starting end weld portion. After that, when the weld pool is stably formed, the torch is fixed in a state of being rotated by 90 ° from the state of being overlapped in the welding direction, and the phase of the other wire is also changed with respect to the one wire. A wide steady weld is formed by moving in and out.

At the welding end, the relative movement speed of the welding device and the welding member is increased, and the relative movement and feeding of the wires are stopped after increasing the moving speed of the two wires. To form a high temperature end weld.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 6 show an embodiment of the present invention, in which the same parts as those in FIGS. 7 to 9 are designated by the same reference numerals.

2 and 3 show an example of a welding apparatus applied to the method of the present invention. The welding apparatus 12 is provided so as to be movable along the welding direction 5. A torch 14 is provided which can rotate forward and backward by a rotary motor 13 and whose rotation angle can be adjusted and whose rotation can be fixed at an arbitrary rotational position.

The torch 14 is led with two wires 1 and 2 which can be separately put in and taken out by pulse-feeding wire feeding devices 15 and 16, respectively.
Are provided with a required interval in the direction of the welding member 6 and wire tips 17, 18 are provided at the tips of the wire guides 17, 18.
20 is attached. The phases of the wires 1 and 2 are individually controlled by a plurality of welding power sources (not shown).

In FIG. 2, two wires 1, 2 are welded in a welding direction 5.
3 shows the state in which the torch 14 has been rotated so as to overlap with the above, and FIG. 3 shows the state in which the torch 14 has been rotated by 90 ° from the state in which it overlaps in the welding direction 5.

In the above, the case where the welding device 12 travels along the welding direction 5 has been described.
May be fixed and the welding member 6 may be moved, that is, the welding device 12 and the welding member 6 may be moved relatively.

Next, as shown in FIGS. 4 to 6, the case where the second layer bead 4 is formed on the first layer bead 3 will be described with reference to FIG.
The operation of the present invention will be described with reference to FIG.

When welding the welding start portion 7, the welding device 1 is rotated with the torch 14 being rotated so that the two wires 1 and 2 overlap in the welding direction 5.
After the relative movement between the welding member 2 and the welding member 6 is started and the relative movement is stabilized, the welding is started by moving the one wire 1 in and out, and the torch 14 is reciprocated at a required rotation angle (for example, 45 °). By rotating, the narrow width start end weld portion 21 is formed as shown in FIGS.

After that, when the weld pool is stably formed, the torch 14 is fixed in a state of being rotated by 90 ° from the state of being overlapped in the welding direction 5 (the state of FIG. 3), and The wire 2 also forms the wide steady welding portion 22 by starting the action of changing the phase with respect to the one wire 1 and putting it in and out. In this state, continuous welding of the steady part is performed.

According to the above, the welding start portion 7 gradually changes from the narrow width welding portion 21 having a small width dimension and a small thickness dimension to the width and thickness of the steady portion. It is possible to obtain a high adhesive force without forming a groove. Further, even when a bead of the third layer is further formed on the welding starting end portion 7, it is possible that the welding starting end portion 7 has a gentle shape with no protruding portion, so that a welding defect may occur inside. It can be prevented.

When welding the welding end portion 10, the relative moving speed of the welding device 12 and the welding member 6 is increased, and the moving speed of the two wires 1 and 2 is increased,
After holding this state for the required time, feed the wires 1 and 2,
By stopping the relative movement between the welding device 12 and the welding member 6, the high temperature terminal welded portion 23 is formed. As described above, the welding of the welding end portion 10 is performed at high output by accelerating the movement of the wires 1 and 2, thereby facilitating the penetration and increasing the adhesive force, and the relative speed between the welding device 12 and the welding member 6 is increased. By increasing the thickness, it is possible to reduce the thickness dimension of the welding end portion 10 and prevent the formation of the protrusions as in the conventional case.

Therefore, according to the above, it is possible to completely eliminate or reduce the cutting work of the welding start end portion 7 and the welding end portion 10.

The present invention is not limited to the above-described embodiment, and when forming a narrow steady welding portion, control may be performed so that the rotation angle of the torch is gradually increased. Of course, various changes can be made without departing from the scope of the present invention.

[0024]

According to the method for treating the start and end of the consumable electrode welding of the present invention described above, it is possible to prevent formation of a projection or welding defect at the start and end of the consumable electrode welding. Can have the effect.

[Brief description of drawings]

FIG. 1 is an operation diagram showing an embodiment of the present invention.

FIG. 2 is a side view showing an example of a welding apparatus applied to the present invention.

FIG. 3 is a side view showing an operating state in which the torch of FIG. 2 is rotated by 90 °.

FIG. 4 is a plan view showing the shape of the welding start end portion according to the present invention.

FIG. 5 is a side view of FIG.

FIG. 6 is a side view showing the shape of a welding end portion according to the present invention.

FIG. 7 is a plan view showing a shape of a welding start end portion according to a conventional method.

FIG. 8 is a side view of FIG.

FIG. 9 is a side view showing a shape of a welding end portion according to a conventional method.

[Explanation of symbols]

 1 Wire 2 Wire 5 Welding Direction 6 Welding Member 7 Welding Start Part 10 Welding End Part 12 Welding Device 14 Torch 21 Narrow Starting End Welding Part 22 Wide Steady Welding Part 23 High Temperature Ending Welding Part

Claims (1)

[Claims] 1. A welding start and end treatment method when consumable electrode welding is performed by a welding device equipped with a torch that can guide and rotate two wires that can be moved in and out separately. Start the relative movement between the welding device and the welding member while rotating the torch so that the two wires overlap in the welding direction, and then start welding by moving one wire in and out and rotate the torch as required. When the narrow start welding portion is formed by reciprocatingly rotating at an angle, and then the welding pool is stably formed, the torch is overlapped in the welding direction from the overlapping state.
The wire is fixed in a state of being rotated by 0 °, and the other wire is moved into and out of the one wire while changing its phase to form a wide steady welding portion, and at the welding end portion, the welding device and the welding member are joined. A method for treating the beginning and end of consumable electrode welding, which comprises increasing a relative moving speed and increasing a moving speed of the two wires to form a high temperature end welding portion.