Welding jig, welding device, and welding method

Abstract

To provide a welding jig which enables welding and proper shielding of a rear surface of a welding portion to be performed by one worker, and to provide a welder including the welding jig and a welding method using the welding jig.SOLUTION: A welding jig is used to shield a rear surface of a welding portion with an inert gas and includes: a hollow body; an intake port which takes the inert gas from a gas tube into the body; and multiple jet holes for jetting the inert gas in the body.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a welding jig for supplying a shielding gas to the rear surface of a welding point, a welding device including the welding jig, and a welding method using the welding jig. [Background technology]

[0002] For example, when welding thin plates such as stainless steel, a weld bead is formed on the back side of the weld, but oxidation, poor formation, defects, etc. of the weld bead degrade the quality of the weld. Taking this into consideration, for example, Patent Document 1 (JP 2015-526298 A) proposes supplying shielding gas to the back side of the weld. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2015-526298 Summary of the Invention [Problem to be solved by the invention]

[0004] Shielding must be performed in an appropriate position and with the appropriate amount of gas, but the backside of the weld cannot be seen by the welding worker. Therefore, in order to properly shield the backside of the weld, two people are required to work together: one person in charge of welding and one person in charge of shielding. In other words, there is still room for improvement in conventional welding and shielding from the perspective of work efficiency.

[0005] Therefore, an object of the present invention is to provide a welding jig that enables one person to perform welding work and appropriate shielding work on the back side of the welded area. Another object of the present invention is to provide a welding device including the welding jig, and a welding method using the welding jig. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides: A welding jig for injecting inert gas onto the back side of a welding point, A hollow body; an inlet for taking the inert gas from a gas pipe into the main body; a plurality of ejection holes for ejecting the inert gas within the main body; The present invention provides a welding jig comprising:

[0007] The welding jig of the present invention preferably further comprises a locking portion that holds the main body in a state in which the plurality of ejection holes face the back surface of the welding location.

[0008] In the welding jig of the present invention, it is preferable that the plurality of ejection holes are aligned along the welding direction.

[0009] The present invention also provides a welding device including any of the welding jigs described above.

[0010] Furthermore, the present invention provides a welding method characterized by using any of the welding jigs described above to weld the welded portion while injecting an inert gas onto the back side of the welded portion. [Effects of the Invention]

[0011] According to the present invention, the welding jig clarifies the working area, and stable and sound welding can be performed while supplying inert gas to the back side of the welding area for appropriate shielding. Therefore, the welding work and the appropriate shielding work for the back side of the welding area can be performed by one person. [Brief explanation of the drawings]

[0012] [Figure 1] 1A and 1B are a front view, a side view, and a top view of a welding jig 1 according to the present embodiment. [Figure 2] 1 is a diagram showing a welding jig 1 attached to a heat exchanger 6 as an example of an object to be welded. [Figure 3]3A and 3B are a top view and a side view showing the details of the welding jig 1 shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0013] Representative embodiments of the welding jig, welding apparatus, and welding method according to the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to those shown in the drawings. Since the drawings are intended to conceptually explain the present invention, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding. In the following description, the same or equivalent parts will be designated by the same reference numerals, and duplicate explanations may be omitted.

[0014] In this embodiment, a heat exchanger 6 is taken as an example of an object to be welded. More specifically, the welding device 7 and welding jig 1 are used in a situation where a plurality of plates 63 are welded between a pair of frames 61, 62 (see FIG. 2). Here, the frames 61, 62 and the plates 63 include thin plates such as stainless steel. It goes without saying that the welding device 7 and welding jig 1 can also be used to weld objects other than the heat exchanger 6.

[0015] The welding jig 1 is an auxiliary tool for injecting an inert gas onto the back side of the welding point W to shield the back side, and is used together with the welding device 7 (see FIG. 3(B)). Welding methods used by the welding device 7 include, but are not limited to, arc welding, laser welding, electron beam welding, and resistance welding. Usable inert gases include, but are not limited to, argon, helium, carbon dioxide, and mixtures thereof. The welding jig 1 is suitably used for welding thin plates such as stainless steel, but is not limited to this.

[0016] 1(A) to 1(C), the welding jig 1 includes at least a main body 2, an inlet 3, and a plurality of nozzle holes 41. The welding jig 1 may be made of, for example, a metal material.

[0017] The main body 2 is hollow and can contain an inert gas in its internal space. The main body 2 includes a pair of opposing face plates 21, 22 and a side wall 23 connecting corresponding edges of the face plates 21, 22. However, an opening 24 is formed in the side of the main body 2 that faces the back surface of the welding point W to allow the inert gas to be ejected.

[0018] In this embodiment, the face plates 21 and 22 of the main body 2 are generally hexagonal, which may be said to be roughly like a home plate. Alternatively, it may be said that the internal space of the main body 2 expands from the intake port 3 toward the ejection holes 41. In other words, the main body 2 is designed so that the inert gas that flows into the main body 2 from the intake port 3 flows smoothly and evenly across the opening 24 of the main body 2 toward the ejection holes 41.

[0019] The main body 2 is fitted with an inlet 3. The inlet 3 is cylindrical and connected to a gas pipe 71. The inlet 3 takes in the inert gas from the gas pipe 71 into the main body 2.

[0020] A perforated plate 4 including a plurality of ejection holes 41 is attached to the opening 24 of the main body 2. As shown in FIG. 3(B), the plurality of ejection holes 41 are arranged to face the rear surface of the welding point W, and eject the inert gas G from inside the main body 2. The perforated plate 4 can be configured as, for example, a punched plate, but is not limited to this.

[0021] The perforated plate 4 is formed in a rectangular shape that extends long in one direction so as to fit into the elongated opening 24 (see FIG. 1(C)). Therefore, the multiple ejection holes 41 are aligned along the direction in which the perforated plate 4 extends (i.e., the welding direction). This allows the inert gas to be sprayed over a certain range during welding.

[0022] Here, the inner diameter of the multiple ejection holes 41 is preferably, for example, 2.0 mm to 2.6 mm so that a sufficient amount of inert gas can be sprayed onto the rear surface of the welding point W. Furthermore, the interval between adjacent ejection holes 41 is preferably, for example, 8 mm to 12 mm so that the inert gas can be sprayed evenly onto the rear surface of the welding point W.

[0023] In this embodiment, the perforated plate 4 is disposed inside the edge of the opening 24 of the main body 2 (see FIGS. 1(A) and 1(B)). This is to allow the inert gas injected from the injection holes 41 to be guided along the inner surface of the main body 2 (or its direction of travel restricted to a certain range) so that it can reach a predetermined range on the rear surface of the welding point W efficiently or intensively.

[0024] It is preferable that the central portion of the perforated plate 4 be curved more inwardly toward the inside of the main body 2 than the both end portions (see FIG. 1(A)). This is also to enable the inert gas jetted from the jet holes 41 to efficiently or intensively reach a predetermined range on the rear surface of the welding spot W. The curvature of the perforated plate 4 is preferably, for example, a radius of curvature of 125 mm to 150 mm.

[0025] The welding jig 1 may further include a locking portion 5. The locking portion 5 holds the main body 2 in a state in which the plurality of ejection holes 41 face the back surface of the welding point W.

[0026] In this embodiment, the locking portion 5 is made up of a pair of metal pieces having a certain width. The locking portion 5 is curved at the tip to form a hook portion 51, which can be hooked onto an object to be welded (for example, a beam-shaped member such as the frame 61 of the heat exchanger 6) (see FIG. 3(B)). However, multiple pairs of locking portions 5 may be provided depending on the shape of the object to be welded.

[0027] Next, a welding method using the welding device 7 and the welding jig 1 will be described. First, the gas pipe 71 is attached to the inlet 3 of the welding jig 1, and the hook 51 of the locking part 5 is hooked onto the welding object (for example, the frame 61 of the heat exchanger 6). Then, the main body 2 is positioned so that the ejection hole 41 faces the back surface of the welding point W (see FIG. 2).

[0028] Next, an appropriate flow rate of inert gas is supplied from gas pipe 71, and an appropriate amount of gas is sent out from welding jig 1 to shield the back surface of welding point W, while welding is performed on welding point W to be welded with welding device 7. At this time, the worker can clearly grasp the range that can be welded at that time (the shielded area) from the position of welding jig 1.

[0029] The welding jig 1 is moved to a position corresponding to the next weldable area, and welding is performed in that area. The welding jig 1 can be moved, for example, by simply sliding the welding jig 1 along the frame 61 of the heat exchanger 6, so this can be easily done by a single welding worker.

[0030] According to this embodiment, the worker can easily grasp the weldable area simply by checking the placement of the welding jig 1. Therefore, with appropriate shielding by inert gas, a stable and sound weld bead can be formed on the back surface.

[0031] Furthermore, since the welding jig 1 can be easily moved, the welding worker can also handle the welding jig 1. In other words, welding and shielding work that previously required two people can now be done by one person, improving work efficiency.

[0032] Although typical embodiments of the present invention have been described above, the present invention is not limited to these, and various design modifications are possible, and all such modified design aspects are included in the technical scope of the present invention. [Explanation of symbols]

[0033] 1 Welding jig 2 Main unit 3 Intake port 4 Perforated plate 5 Locking part 6 Heat exchanger 7. Welding equipment

Claims

1. A welding jig for injecting inert gas onto the back side of a welding point, a hollow body having an opening; an inlet for taking the inert gas from a gas pipe into the main body; a porous plate attached to the opening and including a plurality of ejection holes for ejecting the inert gas within the body; a locking portion that holds the main body in a state in which the plurality of nozzles face the back surface of the welding portion; Equipped with the perforated plate is disposed inside the body as viewed from the edge of the opening, The central portion of the porous plate is curved more inward than both end portions. A welding jig characterized by:

2. the plurality of nozzle holes are aligned along the welding direction; The welding jig according to claim 1 ,

3. A welding device including a welding jig as described in claim 1 or 2.

4. 3. A welding method comprising: welding a welded portion using the welding jig according to claim 1, while injecting an inert gas onto a rear side of the welded portion.

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