JP6999458B2 - Shield box, welding equipment and welding method - Google Patents

Description

The present invention relates to a shield box, a welding device and a welding method.

In arc welding of active metals such as titanium and zirconium, oxides or nitrides are formed by the reaction of high temperature parts (molten metal parts and heat affected zones) with oxygen or nitrogen in the atmosphere. Therefore, the performance of the high temperature portion deteriorates. Further, in arc welding of stainless steel, when a high temperature portion is exposed to the atmosphere, an oxide generally called temper color is generated on the surface. Therefore, the corrosion resistance of the high temperature portion is lowered and the appearance is deteriorated.

Therefore, when these metals that easily react with the atmosphere at high temperatures are arc-welded, the molten metal part and the heat-affected zone are used with an inert gas such as argon gas until the molten metal part and the heat-affected zone are below a certain temperature. A technique called after-shielding is often used to protect the skin. In this after-shield, a welding auxiliary jig called a shield box is used.

For example, Japanese Patent Application Laid-Open No. 1-38177 (Patent Document 1) describes a shield box used for after-shielding. The shield box described in this publication covers the front, back, left and right of the welding torch with respect to the traveling direction (welding direction) of the welding torch. The portion of the shield box placed in front of the welding torch in the welding direction is made of transparent glass. A gas lens for dispersing the inert gas in the shield box is arranged behind the welding direction of the welding torch.

Jikkenhei 1-38177 Gazette

In the shield box described in the above publication, the welding bead immediately after welding is located below the gas lens arranged behind the welding torch in the welding direction. Therefore, it is difficult to detect the state of the weld bead immediately after welding from the outside of the shield box through the transparent glass arranged in front of the welding direction of the welding torch.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a shield box, a welding device, and a welding method that facilitates detection of the state of a weld bead immediately after welding.

The shield box of the present invention includes a housing, a welding torch, and a gas diffusion mechanism. The housing has an internal space, a peripheral wall portion, and a ceiling portion. The peripheral wall portion is provided with an opening that communicates with the internal space. The ceiling is connected to the peripheral wall on the opposite side of the opening. The weld torch is inserted into the interior space and attached to the ceiling. The gas diffusion mechanism is arranged in the internal space and is for diffusing the inert gas in the internal space. The housing is configured to move in the direction of travel during welding and includes transparent portions provided on at least a portion of the peripheral wall and ceiling behind the welding torch in the direction of travel during welding. No gas diffusion mechanism is arranged between the transparent part and the tip of the welding torch.

According to the shield box of the present invention, a gas diffusion mechanism is arranged between the transparent portion provided on at least a part of the peripheral wall portion and the ceiling portion behind the welding torch in the traveling direction at the time of welding and the tip of the welding torch. Not. Therefore, the tip of the welding torch can be detected from the transparent portion without being obstructed by the gas diffusion mechanism. Therefore, it becomes easy to detect the state of the weld bead immediately after welding formed by the tip of the welding torch.

It is sectional drawing which shows schematic structure of the shield box in one Embodiment of this invention. It is a perspective view schematically showing the structure of the welding apparatus in one Embodiment of this invention. It is a perspective view for demonstrating the welding method in one Embodiment of this invention. It is sectional drawing which shows roughly the structure of the shield box in the comparative example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following figures, the same or corresponding parts are designated by the same reference numerals, and duplicate explanations will not be repeated. The configuration of the shield box 1 according to the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view for explaining the shield box 1 in the present embodiment.

The shield box 1 in the present embodiment includes a housing 2, a welding torch 3, a gas diffusion mechanism 4, a sensor 5, and a gas hose 7. The housing 2 is configured to move in the traveling direction D1 during welding. The traveling direction D1 at the time of welding is the welding direction.

The housing 2 has an internal space 11, a peripheral wall portion 12, a ceiling portion 13, and a transparent portion 14. The internal space 11 is a space surrounded by the peripheral wall portion 12 and the ceiling portion 13. The peripheral wall portion 12 has a front wall 12a, a rear wall 12b, and left and right side walls 12c (FIG. 2). The peripheral wall portion 12 is provided with an opening 15. The opening 15 communicates with the internal space 11. The ceiling portion 13 is connected to the peripheral wall portion 12 on the opposite side of the opening 15. The ceiling portion 13 faces the opening 15. The lower surface of the housing 2 has a rectangular shape. A rectangular opening 15 is provided on the lower surface of the housing 2.

The housing 2 has the simplest shape of a rectangular parallelepiped box on five sides. Hereinafter, the housing 2 will be described as a rectangular parallelepiped box shape having five faces, but any shape may be used as long as it can sufficiently cover the welded portion of the material 20 to be welded. Therefore, it suffices to select an appropriate shape that can sufficiently and sufficiently protect the welded portion from the joint shape of the material 20 to be welded and the interference conditions with the surrounding restraint jigs and the like. For example, in the case of butt welding of flat plates to be welded, a five-sided rectangular parallelepiped box shape is optimal.

However, in the case of butt welding of the materials to be welded 20 having a curved surface such as a cylinder, the lower ends (ends on the opening 15 side) of the left and right side walls 12c of the housing 2 are located at the lower ends of the curved surfaces of the material 20 to be welded from the radius of curvature of the curved surface of the material 20 to be welded. It suffices if a recess having a large radius of curvature of several millimeters is provided.

The welding torch 3 is inserted into the internal space 11. A welding torch insertion port 13a is provided on the ceiling portion 13 of the housing 2. The welding torch 3 is inserted into the internal space 11 of the housing 2 from the welding torch insertion port 13a. The welding torch 3 is attached to the ceiling portion 13. Specifically, the welding torch 3 is fixed to a mounting member 13b that surrounds the welding torch insertion port 13a. The housing 2 is configured to sufficiently cover the periphery of the welding torch 3 in the front-back and left-right directions with respect to the welding direction.

The distance L1 from the welding torch insertion port 13a to the rear wall 12b is larger than the distance L2 from the welding torch insertion port 13a to the front wall 12a in the direction in which the front wall 12a and the rear wall 12b face each other. At the time of welding, the housing 2 moves in the direction from the rear wall 12b toward the front wall 12a, that is, toward the front.

It is desirable that the lower end of the housing 2 (the end on the opening 15 side) and the surface of the material to be welded 20 are separated by about several millimeters. By arranging a flame-retardant cloth, sponge, or the like in the gap between the lower end of the housing 2 and the material 20 to be welded, the airtightness of the internal space 11 of the housing 2 can be enhanced.

Further, for example, a bearing or the like may be provided at the lower end of the housing 2. By partially contacting the bearing or the like with the material to be welded 20, the relative position between the housing 2 and the material to be welded 20 can be stabilized. In this case, the housing 2 and the welding torch 3 do not necessarily have to be fixed at the welding torch insertion port 13a.

Further, it is desirable that the shield box 1 has a long shape in a direction parallel to the welding direction due to its necessary function. In particular, the dimension behind the center of the weld torch insertion port 13a (or the electrode position of the weld torch 3) in the welding direction is sufficient to protect the weld with an inert gas until the temperature drops below a certain temperature (for example, about 400 degrees). It needs to be long, preferably 100 mm or more. The dimension in front of the center of the welding torch insertion port 13a (or the electrode position of the welding torch 3) in the welding direction is preferably about 20 mm (sufficient length that does not interfere with the welding torch 3) or more.

The dimensions in the left-right direction in the welding direction from the center of the welding torch insertion port 13a (or the electrode position of the welding torch 3) may be wide enough to cover the heat-affected zone. The height of the shield box 1 may be such that heat during welding is not excessively trapped, and is preferably 30 mm or more.

When the shield box 1 is used for TIG (Tungsten Inert Gas) welding or the like with a filler material such as a welding wire, an insertion port can be provided on the front wall 12a or the like in the welding direction. It is desirable to open this insertion slot as large as necessary with respect to the wire diameter of the welding wire.

The method of fixing the peripheral wall portion 12 and the ceiling portion 13 constituting the shield box 1 is not limited. Further, the method of fixing the front wall 12a, the rear wall 12b, and the left and right side walls 12c of the peripheral wall portion 12 is not limited. However, these fixing methods must be fixing methods that can sufficiently secure the airtightness inside the shield box 1. Further, it is desirable to use a thin metal plate or the like for the shield box 1. However, a resin or the like may be used as long as it sufficiently satisfies the conditions for use as a welding jig such as heat resistance, weather resistance, and flame retardancy.

The housing 2 has a hole 6 for allowing the inert gas used as the shield gas inside the shield box 1 to flow into the internal space 11. The gas hose 7 is inserted into the hole 6. The gas hose 7 extends from the outside of the housing 2 to the inside of the housing 2 through the hole 6. The gas hose 7 is connected to the gas diffusion mechanism 4 inside the housing 2. The inert gas sent from the gas hose 7 to the gas diffusion mechanism 4 is supplied from the gas diffusion mechanism 4 to the inside of the housing 2.

The gas diffusion mechanism 4 is arranged in the internal space 11 of the housing 2. The gas diffusion mechanism 4 is for diffusing the inert gas into the internal space 11 of the housing 2. The gas diffusion mechanism 4 is configured so that the entire inside of the housing 2 can be uniformly filled with the inert gas.

In the present embodiment, the gas diffusion mechanism 4 includes a columnar nozzle 4a. The axial direction of the nozzle 4a is arranged along the direction in which the lower end (tip) of the nozzle 4a faces the material 20 to be welded. That is, the axial direction of the nozzle 4a is arranged along the direction in which the ceiling portion 13 and the opening 15 face each other. The nozzle 4a is configured to supply the inert gas from the outer peripheral surface of the nozzle 4a. As a result, the nozzle 4a can supply the inert gas from the outer peripheral surface of the nozzle 4a to the entire circumference in the circumferential direction. Further, the nozzle 4a may be configured to supply the inert gas from the lower end (tip) of the nozzle 4a.

The entire circumference of the outer peripheral surface of the nozzle 4a may include a porous body. This makes it possible to supply the inert gas through a large number of micropores on the outer peripheral surface of the nozzle 4a. For the gas diffusion mechanism 4, for example, a small silencer made of a metal sintered body or the like may be used. That is, since the gas diffusion mechanism 4 is used at a high temperature location near the welded portion, it is preferably made of metal. Since the gas diffusion mechanism 4 diffuses the inert gas into the housing 2 while suppressing the flow velocity of the inert gas, a sintered body formed by sintering metal particles is preferable. The gas diffusion mechanism 4 is preferably small in size so as to fit inside the housing 2 and not interfere with other functions. The gas diffusion mechanism 4 may be any mechanism as long as it is made of a material suitable for use as a welding jig and can sufficiently diffuse the inert gas.

In the shield box 1 shown in FIG. 1, two holes 6 are provided in the ceiling portion 13. However, the hole 6 may be provided in the peripheral wall portion 12 instead of the ceiling portion 13. Further, the number of holes 6 may be 3 or more instead of 2. The position of the hole 6 may be any position as long as it does not interfere with the welding torch 3 or the like when the gas diffusion mechanism 4 is attached to the housing 2.

Further, only one hole 6 may be used. As described above, it is desirable that the shield box 1 has a long shape in a direction parallel to the welding direction. Therefore, when a plurality of holes 6 and a plurality of gas diffusion mechanisms 4 are provided, the inert gas is more uniformly housing than when one hole 6 and one gas diffusion mechanism 4 are provided. The entire internal space 11 of 2 can be filled. Therefore, the inert gas can be effectively diffused.

The housing 2 includes a transparent portion 14. The transparent portion 14 is provided at least a part of the peripheral wall portion 12 and the ceiling portion 13 behind the welding torch 3 in the traveling direction D1 at the time of welding. The transparent portion 14 is provided in a part of the housing 2 behind the welding torch insertion port 13a in the welding direction. The transparent portion 14 is a window made of a transparent material.

The gas diffusion mechanism 4 is not arranged between the transparent portion 14 and the tip 3a of the welding torch 3. That is, the gas diffusion mechanism 4 is arranged outside the region between the transparent portion 14 and the tip 3a of the welding torch 3. Further, only the inert gas is arranged between the transparent portion 14 and the tip 3a of the welding torch 3.

The transparent portion 14 is provided so that the state of the molten pool 20a and the weld bead 20b shown in FIG. 2 can be detected by the sensor 5. Therefore, it is preferable that the transparent portion 14 is made of a material that transmits the detection light of the state detection sensors and the like but does not scatter the light. It is desirable that the transparent portion 14 is transparent glass or the like.

The sensor 5 is arranged outside the housing 2. The sensor 5 is attached to the housing 2. The sensor 5 is arranged on the transparent portion 14. The sensor 5 is configured to be able to detect the tip 3a of the welding torch 3 via the transparent portion 14. The sensor 5 is configured to be able to detect the state of the molten pool 20a shown in FIG. 2 and the weld bead 20b immediately after welding. The sensor 5 is a laser sensor or the like.

Further, the method of fixing the transparent portion 14 to at least a part of the peripheral wall portion 12 and the ceiling portion 13 is not limited. However, this fixing method must be a fixing method that can sufficiently secure the airtightness inside the shield box 1.

In the shield box 1 shown in FIG. 1, the transparent portion 14 is provided only in a part of the ceiling portion 13 behind the welding torch insertion port 13a in the welding direction. However, the transparent portion 14 may be provided on the entire rear side of the welding torch insertion port 13a in the ceiling portion 13 in the welding direction. Further, the entire ceiling portion 13 may be a transparent portion 14. That is, the entire ceiling portion 13 may be transparent glass or the like. Even if the entire ceiling portion 13 is made of transparent glass or the like, it does not matter if it has sufficient strength, heat resistance, etc. as a welding jig.

Further, it is most desirable that the transparent portion 14 is provided on the ceiling portion 13. However, the transparent portion 14 may be provided on at least one of the rear wall 12b and the left and right side walls 12c. Further, for example, when a mechanism such as welding groove copying is used, a part or the whole of the front wall 12a and the front of the welding torch insertion port 13a in the ceiling portion 13 in the welding direction is transparent glass or the like. May be.

Next, the configuration of the welding apparatus 10 according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.

The welding device 10 in the present embodiment is for joining the metal objects to be welded 20 by welding. In this embodiment, the arc welding device will be described as the welding device 10. The welding device 10 includes a shield box 1, a welding power source 100, a gas supply device 200, and a control device 300.

The welding power source 100 is for supplying an electric current to the welding torch 3 at the time of arc welding. The gas supply device 200 is for supplying the inert gas to the gas diffusion mechanism 4 of the shield box 1. The inert gas supplied to the shield box 1 is a gas for the shield box. Further, the gas supply device 200 is for supplying the inert gas to the tip 3a of the welding torch 3. The inert gas supplied to the tip 3a of the welding torch 3 is a welding gas for the welding torch.

The control device 300 is for controlling the welding power source 100 and the gas supply device 200. The control device 300 controls the output current of the welding power source 100 to the welding torch 3. The control device 300 controls the supply of the welding wire. The control device 300 controls the drive of the welding torch 3. The control device 300 controls the supply of the inert gas to the tip 3a of the shield box 1 and the welding torch 3.

Next, the welding method according to the embodiment of the present invention will be described with reference to FIGS. 2 and 3. FIG. 3 is a cross-sectional view for explaining the welding method in the present embodiment. The welding method in the present embodiment is a welding method in which a molten pool 20a and a weld bead 20b are generated when the material 20 to be welded is welded.

The shield box 1 of this embodiment may be used in an automated welding process. In FIG. 3, as the most desirable welding method using the shield box 1, TIG welding without a filler material will be described as an example. However, even in TIG welding with a filler material, the shield box 1 of the present embodiment can be applied by providing an insertion port for the filler material.

Further, the shield box 1 of the present embodiment can also be used for MIG, (Metal Inert Gas) welding and the like. However, since MIG welding generates more spatter and fume than TIG welding, when the shield box 1 of the present embodiment is used for MIG welding, welding soundness and maintainability of the shield box 1 are fully considered. There is a need.

The shield box 1 is used in a state where the welding torch 3 is inserted into the welding torch insertion port 13a. As described above, it does not matter whether or not the welding torch 3 and the housing 2 are fixed at the welding torch insertion port 13a. However, it is necessary that the material to be welded 20 and the lower end of the peripheral wall portion 12 of the housing 2 do not come into direct contact with each other and the gap between the two is not too large. It is desirable that this gap is about 1 mm to 5 mm. However, when a flame-retardant cloth, sponge, or the like is used at the lower end of the peripheral wall portion 12 of the housing 2, there may be no gap between the flame-retardant cloth, sponge, or the like and the material 20 to be welded. .. However, when these flame-retardant cloths, sponges, etc. come into contact with the material to be welded 20, care must be taken not to damage the material to be welded 20 or contaminate the surface of the material to be welded 20. be.

The inert gas 16 is supplied to the inside of the housing 2 through the gas hose 7 and the gas diffusion mechanism 4 provided in at least a part of the peripheral wall portion 12 and the ceiling portion 13. The inert gas 16 fills the entire inside of the shield box 1. The inert gas 16 is preferably the same type of gas as the shield gas flowing out of the welding torch 3, and particularly high-purity argon gas is most desirable. The inert gas 16 is preferably transparent.

Further, it is desirable that the inert gas 16 is always supplied during welding and always flows out from the gap between the housing 2 and the material to be welded 20 to the outside. The flow rate of the supplied inert gas 16 depends on the internal volume of the housing 2, the gap between the lower end of the housing 2 and the material to be welded 20, or the required welding quality. The flow rate of the supplied inert gas 16 is preferably at least 3 liters per minute or more.

As described above, in the welding method of the present embodiment, the inert gas 16 is diffused into the internal space 11 of the housing 2 of the shield box 1. Then, the state of the molten pool 20a and the weld bead 20b generated when the material 20 to be welded is welded by the welding torch 3 with the inert gas 16 diffused in the internal space 11 is a sensor arranged outside the housing 2. 5 is detected from the transparent portion 14.

The detection light 5a emitted from the sensor 5 passes through the transparent portion 14 and is directly applied to the molten pool 20a and the weld bead 20b immediately after welding, whereby the molten pool 20a and the weld bead 20b immediately after welding are detected. The detection light 5a of the sensor 5 moves as the shield box 1 moves in the traveling direction D1.

Based on the states of the molten pool 20a and the welding bead 20b detected by the sensor 5, the inert gas 16 may be supplied from the gas diffusion mechanism 4 until the arc welding operation is stopped and the time reaches a certain time or longer. Further, even if the arc welding operation is stopped and the inert gas 16 is supplied until the temperature of the welded portion drops below a certain temperature based on the states of the molten pool 20a and the weld bead 20b detected by the sensor 5. good. The states of the molten pool 20a and the weld bead 20b detected by the sensor 5 may be displayed on a monitor (not shown).

Next, the action and effect of the present embodiment will be described in comparison with the comparative example.
FIG. 4 is a cross-sectional view for explaining the shield box 31 in the comparative example. The shield box 31 in this comparative example is for a general after-shield.

The shield box 31 in the comparative example shown in FIG. 4 includes a housing 32, a welding torch 33, an inert gas blowing mechanism 34, and a gas pipe 35. A welding torch 33 is fixed to the housing 32. The portion of the housing 32 arranged in front of the welding torch 33 in the welding direction is open. The inert gas is supplied from the gas pipe 35 to the inside of the housing 32. The inert gas is supplied from the inside of the housing 32 to the outside of the housing 32 through the inert gas blowing mechanism 34. The inert gas spraying mechanism 34 is arranged on the surface of the housing 32 on the side to be welded 20. The inert gas blowing mechanism 34 is a gas lens, a filter, or the like.

In the welding method using the shield box 31 in the comparative example, as shown by the broken line arrow in FIG. 4, the inert gas supplied to the inside of the housing 32 is sprayed onto the welding bead 20b through the inert gas blowing mechanism 34. As a result, the high temperature weld bead 20b is protected from the surrounding atmosphere by the inert gas. However, due to the structure of the shield box 31 in the comparative example, a flow velocity difference occurs between the airflow around the arc of the welding torch 33 and the airflow of the inert gas emitted from the housing 32. Therefore, a vortex that entrains the unshielded peripheral atmosphere is likely to occur between the welding torch 33 and the housing 32.

Impurities such as oxidized slag are generated on the surface of the molten pool 20a due to the vortex containing the surrounding atmosphere, so that there is a risk of causing oxidation of the weld bead 20b and the heat-affected zone. Especially in the welding of thin plates such as titanium and stainless steel, welding defects such as melt-off may occur, and the welding method using the shield box 31 in the comparative example is insufficient for precision welding. Is.

On the other hand, in the shield box 1 in the present embodiment, since the peripheral wall portion 12 is closed, the internal space 11 is surrounded by the peripheral wall portion 12. Since the internal space 11 is set as an inert gas atmosphere and welding is performed inside the housing 2, it is possible to prevent entrainment of the outside air. Further, there is a flow velocity difference between the airflow around the arc of the welding torch 3 and the airflow of the inert gas 16 filling the inside of the housing 2, but since the welding is performed in the inert gas atmosphere, the vortex due to the flow velocity difference. However, impurities such as oxidized slag are not generated on the surface of the molten pool 20a. Therefore, according to the shield box 1 in the present embodiment, it is possible to obtain a healthier weld bead 20b and a heat-affected zone with less surface oxidation as compared with the shield box 31 in the comparative example.

Further, the shield box 1 in the comparative example has an inert gas blowing mechanism 34 such as a gas lens behind the welding torch 33 in the welding direction due to its required performance. The inert gas spraying mechanism 34 is arranged directly above the welding bead 20b immediately after welding. Therefore, since the welding bead 20b immediately after welding is covered by the inert gas spraying mechanism 34, it is difficult to detect the state of the welding bead 20b immediately after welding. Therefore, it is also difficult to detect the state of the weld bead 20b immediately after welding by directly irradiating the detection light of a laser sensor or the like. Further, if the state of the weld bead 20b immediately after welding is to be detected in the shield box 1 in the comparative example, it is necessary to install the inert gas blowing mechanism 34 such as a gas lens away from the welding torch 3. In this case, the welding quality is deteriorated.

On the other hand, according to the shield box 1 in the present embodiment, the transparent portion 14 provided on at least a part of the peripheral wall portion 12 and the ceiling portion 13 behind the welding torch 3 in the traveling direction D1 at the time of welding, and the welding torch 3 The gas diffusion mechanism 4 is not arranged between the tip 3a and the tip 3a. Therefore, the tip 3a of the welding torch 3 can be detected from the transparent portion 14 without being hindered by the gas diffusion mechanism 4. Therefore, it becomes easy to detect the state of the weld bead 20b immediately after welding formed by the tip 3a of the welding torch 3.

Further, if the transparent portion 14 is arranged in front of the welding torch 3 in the traveling direction D1 at the time of welding, the welding quality before welding can be improved by imitating the welding torch 3 at the welded portion. can. On the other hand, according to the shield box 1 in the present embodiment, since the transparent portion 14 is arranged behind the welding torch 3 in the traveling direction D1 at the time of welding, the states of the molten pool 20a and the welding bead 20b are detected. Welding quality after welding can be confirmed.

Further, since the shield box 31 in the comparative example has an inert gas blowing mechanism 34 such as a gas lens, it is necessary to secure an inert gas flow path. Therefore, the shield box 31 in the comparative example has a complicated structure.

On the other hand, the shield box 1 in the present embodiment only has the gas diffusion mechanism 4 as a mechanism corresponding to the inert gas blowing mechanism 34 of the shield box 31 in the comparative example. Therefore, since it is not necessary to secure the inert gas flow path, the structure of the shield box 1 is extremely simple. Further, since the structure of the shield box 1 is extremely simple, the maintainability of the shield box 1 is also improved. Further, in the shield box 1 of the present embodiment, since the gas diffusion mechanism 4 is used in the atmosphere of the inert gas 16, the performance of the gas diffusion mechanism 4 is unlikely to deteriorate.

According to the shield box 1 in the present embodiment, the nozzle 4a and the outer peripheral surface of the nozzle 4a are configured to supply the inert gas. Therefore, even if the gas lens is not provided on the entire rear side of the welding torch 3 as in the comparative example, the inert gas is supplied from the entire circumference of the outer peripheral surface of the nozzle 4a, so that the inert gas is inert to the internal space 11 of the housing 2. It facilitates uniform diffusion of the gas.

According to the shield box 1 in the present embodiment, the entire circumference of the outer peripheral surface of the nozzle 4a contains a porous body. As a result, the inert gas can be supplied from the entire circumference of the outer peripheral surface of the nozzle 4a. Further, by supplying the inert gas from the porous body, it becomes easy to uniformly diffuse the inert gas into the internal space 11 of the housing 2.

According to the welding device 10 in the present embodiment, the shield box 1 described above and the gas supply device 200 for supplying the inert gas to the shield box 1 are provided. Therefore, it is possible to provide a welding device 10 that makes it easy to detect the state of the welding bead 20b immediately after welding formed by the tip 3a of the welding torch 3.

In the welding method using the shield box 1 in the comparative example, since the welding bead 20b immediately after welding is covered by the inert gas spraying mechanism 34, it is difficult to detect the state of the welding bead 20b immediately after welding. Therefore, it is also difficult to detect the state of the weld bead 20b immediately after welding by directly irradiating the detection light of a laser sensor or the like.

On the other hand, in the welding method of the present embodiment, the weld bead 20b generated when the material to be welded 20 is welded by the welding torch 3 in a state where the inert gas is diffused into the internal space 11 of the housing of the shield box 1. The state is detected from the transparent portion 14 by the sensor 5 arranged outside the housing 2. Therefore, it becomes easy to detect the state of the weld bead 20b immediately after welding formed by the tip 3a of the welding torch 3.

Further, at the same time as the material 20 to be welded is welded, the state of the molten pool 20a and the weld bead 20b can be detected by irradiating the detection light 5a from the sensor 5.

Further, by directly irradiating the molten pool 20a and the welding bead 20b immediately after welding with the detection light 5a of the sensor 5 transmitted through the transparent portion 14, welding defects and the like can be detected in-process. That is, welding defects and the like can be detected during the manufacturing process.

The inside of the housing 2 is a space filled with the inert gas 16 except for the welding torch 3 and the gas diffusion mechanism 4. That is, there is nothing blocking the detection light 5a between the transparent portion 14 and the weld bead 20b. Further, it is not necessary to install the sensor 5 such as a laser sensor in the vicinity of the welding torch 3 and the inside of the housing 2 where the temperature becomes high. Therefore, it is possible to easily and stably detect the state during welding.

Further, in contrast to the method in which the inert gas is directly sprayed on the welding bead 20b in the comparative example, in the welding method in the present embodiment, welding is performed in the shield box 1 filled with the inert gas, which is necessary for the shield. The amount of inert gas can be significantly reduced.

As described above, according to the welding method using the shield box 1 in the present embodiment, the structure of the shield box 1 is simple, but the state can be detected easily and stably in an inert gas atmosphere. High-quality welding can be achieved economically.

In the present invention, the contents of each embodiment can be freely combined, and each embodiment can be appropriately modified or omitted within a consistent range.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Shield box, 2 housing, 3 welding torch, 3a tip, 4 gas diffusion mechanism, 4a nozzle, 5 sensor, 5a detection light, 6 holes, 7 gas hose, 10 welding equipment, 11 internal space, 12 peripheral wall, 12a front Wall, 12b rear wall, 12c side wall, 13 ceiling, 13a weld torch insertion slot, 13b mounting member, 14 transparent part, 15 opening, 16 inert gas, 20 welded material, 20a molten pool, 20b weld bead, 100 weld Power supply, 200 gas supply device, 300 control device, D1 direction of travel.

Claims (5)

A housing having an internal space, a peripheral wall portion provided with an opening communicating with the internal space, and a ceiling portion connected to the peripheral wall portion on the opposite side of the opening.
A welding torch inserted into the interior space and attached to the ceiling,
It is arranged in the internal space and has a gas diffusion mechanism for diffusing the inert gas in the internal space.
The housing is configured to move in the traveling direction during welding, and a transparent portion provided on at least a part of the peripheral wall portion and the ceiling portion behind the welding torch in the traveling direction during welding. Including
A shield box in which the gas diffusion mechanism is not arranged between the transparent portion and the tip of the welding torch. The gas diffusion mechanism includes a columnar nozzle and includes a columnar nozzle.
The shield box according to claim 1, wherein the nozzle is configured to supply an inert gas from the outer peripheral surface of the nozzle. The shield box according to claim 2, wherein the entire circumference of the outer peripheral surface of the nozzle contains a porous body. The shield box according to any one of claims 1 to 3 and the shield box.
A welding device provided with a gas supply device for supplying an inert gas to the gas diffusion mechanism of the shield box. A welding method in which a weld bead is generated when the material to be welded is welded.
The step of diffusing the inert gas into the internal space of the housing of the shield box according to any one of claims 1 to 3.
The state of the weld bead that occurs when the material to be welded is welded by the weld torch with the inert gas diffused in the internal space is detected from the transparent portion by a sensor arranged outside the housing. Welding method with the process of performing.

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