JP7037717B2 - Welding method - Google Patents

Description

The present invention relates to a welding method, and more particularly to a welding method for sealing a welded portion with a shield gas.

For example, when welding metals to each other, it is generally practiced to keep the welded portion sealed with a shield gas in order to suppress oxidation and nitriding of the welded portion (Patent Documents 1 and 2). Etc.).

For example, Patent Document 1 discloses a welding apparatus that performs welding in a state where the welded portion is filled with a shield gas by moving the shield trailer along the welded portion together with the laser irradiation head. Further, Patent Document 2 discloses a welding apparatus in which a welding chamber covering the entire welded portion is movably arranged and the inside of the welding chamber is placed in a reduced pressure environment for welding.

Japanese Unexamined Patent Publication No. 2010-23396 Japanese Unexamined Patent Publication No. 2014-205148

However, although the shield trailer described in Patent Document 1 can be used when the work having a welded portion has a planar shape, when the work has a curved surface shape, there is a gap between the shield trailer and the work. There is a problem that it is difficult to seal the welded portion with a shield gas.

Further, the welding chamber described in Patent Document 2 can be used even when the work having a welded portion has a curved shape, but when the welding range is large, the welding chamber becomes large and welding is performed. There is a problem that it is difficult to install a welding chamber when the work having a portion is small.

The present invention has been devised in view of such a problem, and even when the work having a welded portion has a curved surface shape, the welded portion can be easily welded with a shield gas regardless of the range to be welded or the size of the work. It is an object of the present invention to provide a welding method that can be sealed in.

According to the present invention, a main body having a hollow portion and a lid member attached to the opening of the hollow portion to seal the hollow portion are provided, and a welded portion is provided by a boundary line between the main body and the lid member. A method of welding a configured work, which includes an annular or tubular wall member arranged on the main body so as to surround the outer periphery of the welded portion and having an installation surface in close contact with the surface of the main body. The first step of preparing the tool, the second step of arranging the welding jig on the main body, the third step of supplying the shield gas to the space surrounded by the wall member, and the shielding of the welded portion. A welding method comprising a fourth step of welding while maintaining a gas-sealed state is provided.

According to the welding method according to the present invention described above, only the outer periphery of the welded portion is surrounded by a welding jig having a wall member, and the installation surface of the wall member is brought into close contact with the surface of the work, whereby the work and the wall are formed. The gap between the members can be reduced, and the welded portion can be sealed with the shield gas by supplying the shield gas to the space surrounded by the wall members.

Further, according to the welding method according to the present invention, a welding jig can be easily designed according to the shape of the work or the welded portion, and even when the work having the welded portion has a curved surface shape. The welded portion can be easily sealed with the shield gas regardless of the welding range and the size of the work.

It is a perspective view which shows an example of the work which has a weld part, (a) shows the state which separated parts to be welded, (b) is the state which combined parts to be welded. It is a figure which shows the welding jig which concerns on 1st Embodiment of this invention, (a) is a perspective view, (b) is a sectional view taken along the line BB in FIG. 2 (a). It is a figure which shows the welding method which concerns on one Embodiment of this invention. It is a figure which shows the welding jig which concerns on the 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1A to 4A. Here, FIG. 1 is a perspective view showing an example of a work having a welded portion, (a) shows a state in which parts to be welded are separated, and (b) shows a state in which parts to be welded are combined. 2A and 2B are views showing a welding jig according to the first embodiment of the present invention, FIG. 2A is a perspective view, and FIG. 2B is a cross-sectional view taken along the line BB in FIG. 2A. ing.

The welding method according to the embodiment of the present invention is arranged on the work 1 so as to surround only the outer periphery of the welded portion W as shown in FIGS. 1 (a) to 3 and is placed on the surface of the work 1. In the space surrounded by the wall member 21, the first step of preparing the welding jig 2 including the wall member 21 having the installation surface 21a in close contact, the second step of arranging the welding jig 2 on the work 1, and the space surrounded by the wall member 21. It includes a third step of supplying the shield gas G and a fourth step of welding while keeping the welded portion W sealed with the shield gas G.

The work 1 is, for example, as shown in FIGS. 1A and 1B, a main body 11 having a hollow portion 11a and a lid member attached to the opening of the hollow portion 11a to seal the hollow portion 11a. It is equipped with twelve. The welded portion W is composed of a boundary line between the main body 11 and the lid member 12. Although the case where the work 1 has a hemispherical shape is shown here, the shape of the work 1 is not limited to such a shape. For example, the work 1 may be a plate material having a curved surface shape formed by a concave surface, a convex surface, or an uneven surface.

As shown in FIGS. 2A and 2B, the welding jig 2 is surrounded by a wall member 21 arranged on the work 1 so as to surround only the outer periphery of the welded portion W, and the wall member 21. The wall member 21 is provided with a shield gas supply means 22 for supplying the shield gas G to the space, and the wall member 21 is provided with an installation surface 21a along the surface shape of the surface of the work 1.

The wall member 21 is formed in an annular shape or a cylindrical shape that can surround the outer periphery of the welded portion W. Here, since the welded portion W has a circular shape, the wall member 21 is formed in a ring shape, but the shape is not limited to this. For example, the wall member 21 may have a rectangular shape, an elliptical shape, or the like.

Further, the wall member 21 may be made of metal or a heat-resistant resin. Further, the wall member 21 may be an integrally molded product or a modular product formed by assembling a plurality of parts.

Further, when designing the shape of the wall member 21, it is necessary to pay attention to the horizontal distance D and the height H from the welded portion W as shown in FIG. Specifically, the height H needs to be designed so that the upper end of the wall member 21 is higher than the position of the welded portion W in the state where the welding jig 2 is arranged on the work 1. Further, the horizontal distance D needs to be designed so that the operating region of the welding torch 3 and the wall member 21 do not interfere with each other during welding.

As shown in FIG. 3, the installation surface 21a of the wall member 21 reduces the gap between the wall member 21 and the work 1 when the welding jig 2 is arranged at a predetermined position on the work 1. Is designed to be able to. Specifically, the installation surface 21a is formed in a shape that matches the surface shape of the work 1 at the place where the work 1 is installed. The gap between the wall member 21 and the work 1 can be allowed within a range in which the leakage amount of the shield gas G is sufficiently smaller than the supply amount of the shield gas G.

Further, the upper end surface 21b of the wall member 21 is composed of, for example, as shown in FIG. 2B, a horizontal plane having the same height. Although not shown, the upper end surface 21b may have the same surface shape as the installation surface 21a having a height H with respect to the installation surface 21a. In short, the shape of the upper end surface 21b is arbitrary as long as the wall member 21 has a height of the installation surface 21a in close contact with the work 1 and a predetermined height H or more.

The shield gas supply means 22 is, for example, as shown in FIGS. 2A and 2B, a gas ejection hole 22a for supplying the shield gas G from the side surface of the wall member 21 to the space, and the wall member 21. It includes a manifold 22b formed inside, a gas supply port 22c for supplying the shield gas G to the manifold 22b, and a gas supply source 22d connected to the gas supply port 22c.

The gas ejection hole 22a is formed on the inner side surface 21c of the wall member 21. Further, a manifold 22b forming an annular space is formed inside the wall member 21, and the gas ejection hole 22a is formed so as to communicate with the manifold 22b. Further, the gas supply port 22c is formed so as to communicate with the manifold 22b on the outer surface 21d of the wall member 21. The gas supply port 22c is connected to the gas supply source 22d via a pipe or a hose.

The gas supply source 22d is, for example, a gas cylinder in which the shield gas G is sealed. The shield gas G is an inert gas that blocks the contact between the molten metal and air during welding, and is a gas that suppresses oxidation and nitridation of the welded portion W. In the present embodiment, since only the outer periphery of the welded portion W is surrounded by the welding jig 2 and the upper portion is open, the shield gas G has a specific density higher than that of air, such as argon gas and carbon dioxide gas. Is preferably a large inert gas.

The shield gas supply means 22 is not limited to the above-described configuration. For example, the gas ejection hole 22a, the manifold 22b, and the gas supply port 22c are omitted, and the gas supply source is in the space surrounded by the wall member 21. The shield gas G may be directly supplied from 22d via a pipe, a hose, or the like.

Here, a case of welding using the above-mentioned welding jig 2 will be described with reference to FIG. FIG. 3 is a diagram showing a welding method according to an embodiment of the present invention. The welding jig 2 is designed and manufactured according to the shape of the surface of the work 1 having the target welded portion W (first step).

Next, the welding jig 2 is placed on the surface of the work 1 to surround the outer periphery of the welded portion W (second step). At this time, since the installation surface of the welding jig 2 has a shape in close contact with the surface of the work 1, the gap between the work 1 and the welding jig 2 can be obtained simply by arranging the welding jig 2 at a predetermined position. Can be reduced. Further, in order to fix the welding jig 2, an adhesive may be applied or affixed to the installation surface 21a. Further, when the surface of the work 1 is machined after welding, the welding jig 2 may be fixed to the work 1 by spot welding or the like.

Next, the plug of the gas supply source 22d is opened, and the shield gas G is supplied to the wall member 21. The shield gas G supplied to the wall member 21 is supplied to the space surrounded by the wall member 21 from the gas ejection hole 22a via the manifold 22b (third step). Since the shield gas G has a higher specific gravity than air, it stays and is filled in the space surrounded by the wall member 21. In FIG. 3, the state in which the shield gas G is filled is painted in gray and displayed.

Next, the welded portion W is welded with a welding device (fourth step). The welding device is, for example, a laser welding device. The laser welding apparatus includes, for example, a laser oscillator (not shown) that generates a laser beam, a welding torch 3 (laser head) that includes an optical system that focuses and irradiates the laser beam, and a laser from the laser oscillator to the laser head. It is equipped with an optical fiber (not shown) that carries a beam. Further, the welding torch 3 (laser head) is connected to a moving means (not shown) such as a robot arm, and is configured to be movable to an arbitrary position.

Such a laser welding apparatus may include a protective window 31 arranged at the tip of a welding torch 3 (laser head) in order to protect the optical system from dust, spatter, and the like. Further, the laser welding device may be provided with an air knife 4 that protects the protective window 31 from spatter and the like. The air knife 4 is a device that ejects high-pressure gas onto the surface of the protective window 31.

Since the laser welding device and the air knife 4 can be used by arbitrarily selecting a commercially available device, FIG. 3 shows a simplified configuration.

Further, at the time of welding, it is preferable to perform welding while continuously supplying the shield gas G to the space surrounded by the wall member 21 by the shield gas supply means 22. By such a process, the welded portion W can be kept sealed with the shield gas G.

According to the welding method using the welding jig 2 according to the present embodiment described above, only the outer periphery of the welded portion W is surrounded by the welding jig 2 having the wall member 21, and the installation surface 21a of the wall member 21 is used as the work 1. By making it adhere to the surface, the gap between the work 1 and the wall member 21 can be reduced, and by supplying the shield gas G to the space surrounded by the wall member 21, the welded portion W is shielded gas. It can be sealed with G.

Further, according to the welding jig 2 according to the present embodiment, the welding jig 2 can be easily designed according to the shapes of the work 1 and the welded portion W, and the work 1 having the welded portion W has a curved surface shape. Even in a certain case, the welded portion W can be easily sealed with the shield gas G regardless of the welding range and the size of the work 1. The welding jig 2 according to the present embodiment can also be used when the work 1 having the welded portion W has a planar shape.

Next, the welding jig according to the second embodiment of the present invention will be described with reference to FIG. Here, FIG. 4 is a diagram showing a welding jig according to the second embodiment of the present invention. The same components as those of the welding jig 2 according to the first embodiment described above are designated by the same reference numerals, and duplicated description will be omitted.

As shown in FIG. 4, when the welding jig 2 having the wall member 21 is arranged on the work 1, the surface of the work 1 (cover member 12) in the space surrounded by the wall member 21 is the wall member 21. It may be lower than the height H. In this case, since the space for filling the shield gas G becomes wide, the amount of the shield gas G supplied to the space surrounded by the wall member 21 increases, and it takes time to fill the shield gas G. It will be necessary.

Therefore, in the welding jig 2 according to the second embodiment, the second wall member 23 arranged so as to face the wall member 21 with the welded portion W interposed therebetween is used. The second wall member 23 includes, for example, an installation surface 23a that is in close contact with the surface of the work 1 and an upper end surface 23b that is arranged at a position higher than the upper end surface 21b of the wall member 21.

The second wall member 23 is formed in a ring shape, for example, but may be formed in an annular shape or a cylindrical shape having a rectangular shape or an elliptical shape. Further, the second wall member 23 may be a block body or a plate-shaped body having no hollow portion. Further, the second wall member 23 may be fixed to the work 1 by an adhesive or spot welding, or may be connected to and fixed to the wall member 21.

By arranging the second wall member 23, a groove-shaped space surrounding both sides of the welded portion W can be formed between the wall member 21 and the second wall member 23, and a space filled with the shield gas G can be formed. The capacity of the shield gas G can be reduced, the amount of the shield gas G used can be reduced, and the filling time of the shield gas G can be shortened.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, for example, the present invention can be applied to welding other than laser welding (for example, arc welding). Of course there is.

1 Work 2 Welding jig 3 Welding torch 4 Air knife 11 Main body 11a Hollow part 12 Lid member 21 Wall member 21a Installation surface 21b Upper end surface 21c Inner side surface 21d Outer side surface 22 Shielded gas supply means 22a Gas ejection hole 22b Manifold 22c Gas supply port 22d Gas supply source 23 Second wall member 23a Installation surface 23b Upper end surface 31 Protective window G Shield gas W Welded part

Claims (1)

Welding of a workpiece having a main body having a hollow portion and a lid member attached to the opening of the hollow portion to seal the hollow portion, and the welded portion formed by a boundary line between the main body and the lid member. It ’s a method,
The first step of preparing a welding jig including an annular or cylindrical wall member arranged on the main body so as to surround the outer periphery of the welded portion and having an installation surface in close contact with the surface of the main body.
The second step of arranging the welding jig on the main body,
The third step of supplying the shield gas to the space surrounded by the wall member,
The fourth step of welding while maintaining the state in which the welded portion is sealed with the shield gas,
A welding method comprising.

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