JPH09262662A - Method and equipment for two sided butt welding of thick metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve whole working efficiency by saving the preparation time and the post-preparation time in performing butt-welding of a thick metal plate. SOLUTION: In performing the butt welding of thick metal plates 21, 22 by the gas shielded consumable electrode welding method, the rear side is welded by moving a preceding consumable welding electrode group 30 in a lower groove, the front side is welded by moving a succeeding consumable welding electrode group 40 in an upper groove, and the succeeding consumable welding electrode group 40 is moved in the same direction with a delay of the prescribed time to continuously performing the front side welding and the rear side welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for welding metal plates, and more particularly, to double-sided butt welding of thick metal plates used as structural members for ships and bridges.

[0002]

2. Description of the Related Art Thick metal plates are used for structural members of ships and the like, and the single-sided submerged arc welding method has been relatively widely used for welding the metal plates. This welding method will be described with reference to FIGS. As shown in FIG.
Granular flux 9 is formed by the flux distribution pipe 3 that moves along the groove formed by the open tips of the metal thick plates 1 and 2.
Is sprayed in advance so as to cover the groove. Each welding wire 11 of the welding electrodes 5, 6, 7 moving along the groove is
As shown in FIG. 6, the tip is in the flux 9, an arc is generated between the thick metal plates 1 and 2 as the base material and the welding wire 11, and the welding wire 11 is melted to perform welding. . The used flux 9 after the completion of welding is sucked and recovered by the recovery pipe 15 that moves following the welding electrodes 5, 6, 7. The feature of the above-mentioned welding method is that the arc is in the flux 9 and is not visible from the outside, but the action allows the arc to be stably maintained even with a large current, which allows the wire melting rate to be increased and the welding efficiency to be improved. There is a point that can be raised. On the other hand, since the amount of heat input is large and the amount of molten metal is large, a heat-resistant backing material 13 and a holding metal fitting 14 are used to prevent the metal thick plates 1 and 2 from being burned down to the back side. Since it is large, a large restraint jig (not shown) is used.

[0003]

The above-mentioned one-sided submerged arc welding method can be performed with a large current, and since the welding direction is downward, the welding itself is extremely efficient and excellent, but as will be described later. There are problems mainly before and after welding. That is, since it is necessary to provide the backing material over the entire length of the welding line, this preparatory work requires a lot of time. Further, the flux is automatically collected by a collecting machine having a collecting pipe. However, since the slag generated on the surface of the weld metal entrains a part of the flux, it is difficult to completely collect the flux. Therefore, it is necessary to remove the slag after the welding is completed and to collect the residual flux with the operator. Further, since a large heat input is used, the heat-affected zone is large, and welding distortion is likely to be large. Therefore, a large restraint jig is used to prevent this. Therefore, it takes a lot of time to attach and detach the restraint jig before and after welding. Furthermore, since the arc and the welding bead cannot be seen from the outside during welding, the stability of the arc and the appearance of the beat can be monitored and judged, and the welding conditions cannot be finely adjusted. It should be noted that, instead of such one-sided submerged arc welding, application of a gas shield consumable electrode type arc welding method so-called MAG welding method from one side to a metal thick plate as shown in FIG. There are still some problems to be solved and it has not been put to practical use. In FIG. 7, reference numeral 17 is a MAG welding electrode and reference numeral 19 is a backing material.
Therefore, an object of the present invention is to provide a method for welding a thick metal plate, which does not have the above-mentioned problems and which can efficiently perform the entire welding work.

[0004]

In order to solve the above problems, according to the present invention, a gas shield consumable electrode type welding method is used for butt welding by forming a double-sided groove on the edge of a thick metal plate. To do. That is, according to the present invention, when joining thick metal plates having double-sided grooves by butt welding, the preceding consumable welding electrode is moved into the lower groove to perform the back surface welding first, and the predetermined time is delayed. The subsequent consumable welding electrode is moved into the groove on the upper side to perform front welding, and back welding and front welding are performed in parallel. Further, in the welding apparatus for carrying out the welding method of the present invention as described above, the leading consumable welding electrode and the trailing consumable welding electrode are arranged so as to face each other across the welded portion so that the above movement is possible. It is preferable that each of the consumable welding electrodes is composed of a plurality of welding electrodes depending on the size of the groove of the welded portion so that the joining is completed by one-pass welding. The above-mentioned "movement" means relative movement with respect to the metal thick plate which is the object to be welded. Therefore, when moving the object to be welded, the installation position of each consumable welding electrode is fixed. .

[0005]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, referring to FIGS. 1 and 2, the metal thick plates 21 and 22 to be joined have double-sided grooves formed at the abutting edges, and the preceding consumable welding electrode group 30 is formed.
The welding electrodes 31, 33, and 35 constituting the above are arranged upward so as to perform back surface welding. Further, the welding electrodes 41, 43, 45, and 47 that constitute the subsequent consumable welding electrode group 40 are arranged downward so as to perform front welding. 1 and 2 are shown as welding being performed in the direction of the arrow, the groove shape of the butt welding of the metal thick plates 21 and 22 is shown in FIG. As is well understood by those skilled in the art, the groove shape itself is a normal shape, but it is relatively difficult to weld it. It is smaller than the cross-sectional area. The dimensions of the groove shape shown are those of the pre-consumable welding electrode group 3
0 is composed of three welding electrodes 31, 33 and 35, and has a higher margin than the maximum groove depth of 4 mm when performing upward welding with one welding electrode. .
When performing backside welding with two or more upward welding electrodes, the welding electrodes 31 and 3 are divided into left and right (width direction).
In the case of the present embodiment in which the back surface welding is performed upwards at 3, 35, as shown in FIG. 4, the welding electrodes 31, 33 are configured so that the upward first layer 31a, the upward second layer 33a, and the upward third layer 35a are welded. , 35 are positioned and arranged. The upward welding bead 27 of the back surface welding shown in FIG. 2 is made of the weld metal of the above-mentioned first layer 31a, the second layer 33a and the third layer 35a. It melts and becomes a part of the downward welding bead 25.

As described with reference to FIGS. 1 and 2, the welding electrodes 41, 4 that constitute the subsequent consumable welding electrode group 40.
3, 45, 47 are arranged along the groove to form the downward first layer 41a, the downward second layer 43a, the downward third layer 45a and the downward fourth layer 47a shown in FIG. 4, respectively. Arranged and oriented. Welding electrodes 31,3
Table 1 shows an example of welding conditions including orientations of 3,35,41,43,45,47.

[0007]

[Table 1]

[0008]

As described above, according to the present invention, when metal thick plates are joined by butt welding by the gas shield consumable electrode type welding method, a groove is formed on both sides and the backside welding is slightly preceded. Since the front surface welding is performed on the back surface welding, it is possible to perform efficient welding as a whole without the need to install a backing material one by one. Furthermore, while the heat effect of backside welding remains, heat is applied from the opposite direction by frontside welding, that is, heat is applied from both sides of the metal thick plate, so there is little heat deformation and installation of a large restraint jig is possible. It can be omitted and the time required for installation and removal of these can be reduced. Therefore, compared with the conventional single-sided submerged arc welding method, the welding work time can be significantly shortened.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an implementation state of a welding method of the present invention.

FIG. 2 is a cross-sectional view showing an implementation state of the welding method of the present invention.

FIG. 3 is a cross-sectional view showing a groove shape of a metal thick plate according to the embodiment of the present invention.

FIG. 4 is an explanatory view showing a cross section of a butt welded portion obtained in the embodiment of the present invention.

FIG. 5 is an overall perspective view showing a welding situation by a conventional welding method.

FIG. 6 is a partial cross-sectional view showing a welding situation by a conventional welding method.

FIG. 7 is an explanatory view showing a welding state by another conventional welding method.

[Explanation of symbols]

 21,22 Metal Thick Plate 30 Consumable Welding Electrode Group 31,33,35 Welding Electrode 40 Consumable Welding Electrode Group 41,43,45,47 Welding Electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsushi Kodama 1-1 No. 1 Satinoura-cho, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries, Ltd. Nagasaki Research Institute

Claims (2)

[Claims] 1. When the metal thick plates are joined to each other by the gas shield consumable electrode welding method while holding the edges having the double-sided grooves in abutting state, the metal plates are preliminarily consumed in the lower groove. Move the welding electrode to perform back surface welding, move the trailing consumable welding electrode into the upper groove to perform front welding,
The double-sided butt welding method for thick metal plates, wherein the trailing consumable welding electrode is moved in the same direction with a predetermined time behind the preceding consumable welding electrode to perform the front welding and the backside welding in parallel. 2. In a welding device for joining metal thick plates to each other by a gas shield consumable electrode type welding method by holding edges having double-sided grooves of the metal thick plates butted against each other, the lower groove is opposed to the welding device. A plurality of preceding consumable welding electrodes movably arranged along the edge of the metal plate, and a plurality of movably arranged along the edge of the metal plate facing the upper groove. Both sides butting of a metal plate having a trailing consumable welding electrode and a synchronous drive control device for controlling the trailing consumable welding electrode so that the trailing consumable welding electrode is moved in the same direction after being delayed from the preceding consumable welding electrode by a predetermined time. Welding equipment.