JP7429673B2 - Welding equipment and welding method - Google Patents

Description

The present invention relates to a welding device and a welding method.

Conventionally, arc welding, which is advantageous in terms of cost and versatility, has been widely adopted as a method for welding structures (objects to be welded) using metals, non-ferrous metals, etc. as base materials. As such arc welding, for example, gas shielded arc welding such as TIG welding (Tungsten Inert Gas welding) using a non-consumable electrode or GTA welding (Gas Tungsten Arc welding) which is plasma arc welding is used. There is. Further, as arc welding, gas shielded arc welding such as MIG welding (Metal Inert Gas welding), MAG welding (Metal Active Gas welding), or GMA welding (Gas Metal Arc welding) using a consumable electrode is also used. .

Note that gas shielded arc welding is not limited to the above-mentioned welding applications; for example,
Since it can be used for brazing workpieces, joining, cutting, thermal spraying, melting furnaces, etc., in the present invention, such uses are also treated as a form of welding.

Generally, in gas-shielded arc welding as described above, an arc is generated between an electrode and the workpiece (base metal) using a welding torch, and the heat of this arc melts the workpiece to form a molten pool. Welding is performed while During welding, shielding gas is ejected from nozzles placed around the electrode. This shielding gas blocks the atmosphere (air) and prevents oxidation of the molten pool. Welding is carried out while protecting the

As mentioned above, as a device that performs gas shield arc welding while injecting shielding gas to the molten pool during welding, for example, a device in which a shielding gas nozzle for supplying shielding gas is placed directly above the molten pool. is known (for example, see Patent Document 1).
Furthermore, a welding apparatus has been proposed in which a shielding gas nozzle is disposed downstream of a welding torch in the welding progress direction, and the welding apparatus performs after-shielding using a shielding gas (see, for example, Patent Document 2).

Here, conventionally, for example, in order to make various adjustments aimed at improving welding conditions and monitor the welding state, cameras are used to take images of the welding part and its surroundings, and the state of the welding torch and the welding part are monitored. Observations are being made on the condition of the
For example, the welding apparatus disclosed in Patent Document 1 mentioned above has a configuration in which a camera is disposed directly above a gas shield nozzle.
Moreover, in the welding apparatus disclosed in Patent Document 2, a camera is installed upstream of the welding torch in the welding progress direction, and is configured to image the molten pool from this upstream side.

Patent No. 6524766 Japanese Patent Application Publication No. 2007-136461

However, in the case of a configuration in which a camera is disposed directly above a gas shield nozzle as in Patent Document 1, there is a problem that the gas shield nozzle obstructs imaging and it is difficult to accurately monitor the welding state.
For this reason, for example, as in the welding device disclosed in Patent Document 2, by separately combining a clamp arm, shaft, holder, etc. for fixing the camera, the camera can be used to observe the molten pool from an oblique direction. It needs to be placed and fixed. However, when adopting a configuration in which a camera is arranged and fixed in combination with a clamp arm, etc. as in Patent Document 2, in order to perform optimal imaging that can monitor the welded part, for example, adjusting the camera angle, There is a problem in that skilled techniques are required to adjust the photographing distance, as well as adjust the focus and aperture of the lens. Furthermore, in the case of a configuration in which a camera is installed upstream of the welding torch in the welding progress direction as in Patent Document 2, there is a possibility that the welding torch may obstruct imaging, and as described above, the welding state can be monitored. There is a problem in that it is difficult to accurately perform the following.

On the other hand, when a configuration is adopted in which shielding gas is supplied downstream in the welding direction as in the welding apparatus disclosed in Cited Document 2, a jig consisting of a shield box or the like is placed downstream of the welding torch. This is necessary. However, in this case, there was a problem in that it became difficult to take an image from the downstream side in the direction of welding progress, making it impossible to accurately observe the molten pool.

The present invention was made in view of the above problems, and it is possible to monitor the welding state with high precision, effectively suppress oxidation of the molten pool, form a good weld bead, and connect the workpieces together. An object of the present invention is to provide a welding device and a welding method that can perform welding.

In order to solve the above problems, the present invention includes the following aspects.
That is, the invention according to claim 1 is a welding device for welding workpieces together by forming a weld bead by gas-shielded arc welding, the workpieces being relatively moved in the welding progress direction along the abutting ends of the workpieces. a welding torch that forms a high-temperature molten pool between the workpieces by forming a welding arc, and a welding torch that is disposed downstream of the welding torch in the welding progress direction and injects shielding gas toward the molten pool. a monitoring imaging unit disposed downstream of the shielding gas nozzle in the welding progress direction and capturing an image of the state of the molten pool from the downstream side, the welding torch, the shielding gas nozzle, and the monitoring imaging unit and an after-shield jig for arranging and integrally fixing the following elements in this order from the upstream side to the downstream side in the welding progress direction.

Further, the invention according to claim 2 is the welding device according to claim 1, characterized in that the monitoring imaging section and the after-shield jig have an integral structure via a connecting fitting. This is a welding device.

Further, the invention according to claim 3 is the welding apparatus according to claim 2, in which the angle of the support lever that supports the monitoring imaging section is variable in the connecting fitting, and the angle of the support lever supporting the monitoring imaging section is variable. This is a welding device characterized in that the imaging direction can be changed.

Further, the invention according to claim 4 is the welding apparatus according to any one of claims 1 to 3, wherein the after-shield jig includes a side wall of a nozzle fixing part to which the shield gas nozzle is fixed. The welding apparatus is characterized in that it has a camera imaging port that is arranged to face the lens of the monitoring imaging section and opens at a position where the molten pool can be imaged by the lens.

Further, the invention according to claim 5 is the welding device according to claim 4, which is arranged at any position between the lens in the monitoring imaging section and the camera imaging port, and the This welding device is characterized by being equipped with an insulating cylinder having an internal space that allows imaging of a molten pool.

Further, the invention according to claim 6 is the welding apparatus according to claim 4 or 5, characterized in that a heat-resistant glass is arranged so as to cover the camera imaging port. .

Further, the invention according to claim 7 is the welding apparatus according to any one of claims 1 to 6, wherein the welding torch has a cylindrical shape with respect to a torch fixing part of the aftershield jig. This welding device is characterized in that it is inserted through an insulating adapter.

Further, the invention according to claim 8 is the welding apparatus according to any one of claims 1 to 7, wherein the shield gas nozzle is provided with a diffusion nozzle at a tip that diffuses and sprays the shield gas. This is a welding device featuring:

Further, the invention according to claim 9 is the welding apparatus according to any one of claims 1 to 8, wherein the after-shield jig is configured to at least connect the monitoring imaging section and the molten pool. This welding device is characterized by comprising a heat shield plate disposed so as to shield the space between the two.

Further, the invention according to claim 10 is the welding apparatus according to any one of claims 1 to 9, in which the monitoring imaging section includes a camera body including the lens, and a camera body provided with the lens, and an incident surface side of the lens. and a cylindrical lens cover having an internal space in which the molten pool can be imaged by the lens, and the camera body and the lens cover are configured to be detachable. It is a device.

The invention according to claim 11 is a welding method for welding workpieces together by forming a weld bead by gas-shielded arc welding using the welding apparatus according to any one of claims 1 to 10.

According to the welding device according to the present invention, it is possible to monitor the welding state with high precision, and it is possible to weld workpieces by forming a good weld bead while effectively suppressing oxidation of the molten pool. It becomes possible.

1 is a diagram schematically explaining a welding device and a welding method according to an embodiment of the present invention, and is a schematic diagram showing an example of the overall configuration of the welding device. FIG. 2 is a diagram schematically explaining a welding device and a welding method according to an embodiment of the present invention, and is a schematic diagram showing an enlarged main part of the welding device shown in FIG. 1, which is fixed to an aftershield jig. FIG. 3 is a diagram illustrating the surveillance imaging unit separated into a camera body and a lens cover. 3 is a schematic diagram schematically explaining a welding device and a welding method according to an embodiment of the present invention, and shows an example in which a heat shield plate and a filter unit are further provided in addition to the after-shield jig shown in FIG. 2. FIG. FIG. 1 is a schematic diagram schematically explaining a welding device and a welding method according to an embodiment of the present invention, and is a perspective view showing an example in which heat-resistant glass is arranged in a camera imaging port provided in an after-shield jig. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram schematically explaining a welding device and a welding method according to an embodiment of the present invention, and is a view of an after-shielding jig seen from the bottom side, showing a diffusion type nozzle provided at the tip of a shielding gas nozzle. It is a schematic diagram.

Hereinafter, a welding device and a welding method that are one embodiment of the present invention will be described with reference to FIGS. 1 to 5 as appropriate. In addition, in the drawings used in the following explanation, in order to make it easier to understand the features of the present invention, characteristic parts may be shown enlarged for convenience, and the dimensional ratios of each component are the same as in reality. Not necessarily. Furthermore, the materials and the like exemplified in the following description are merely examples, and the present invention is not limited thereto, and can be implemented with appropriate changes within the scope of the gist thereof.

<Welding equipment>
FIG. 1 is a schematic diagram showing an example of the overall configuration of a welding device 1 according to the present embodiment, and FIG. 2 is a schematic diagram showing an enlarged main part of the welding device 1 shown in FIG. 4 is a diagram showing the surveillance imaging unit 4 fixed to the jig 10 in a state where it is separated into a camera body 41 and a lens cover 42. FIG.
FIG. 3 is a perspective view showing an example in which the after-shield jig 10 shown in FIG. 2 is further provided with a heat shield plate 16 and a filter unit 46.
FIG. 4 is a perspective view showing an example in which a heat-resistant glass 15 is arranged in the camera imaging port 14 provided in the after-shield jig 10.
Moreover, FIG. 5 is a view of the after-shield jig 10 viewed from the bottom side, and is a schematic diagram showing the shield gas nozzle 3 made of a diffusion type nozzle.

The welding apparatus 1 shown in FIG. 1 welds works 80 (80) together by forming a weld bead (not shown) by gas-shielded arc welding. The illustrated welding apparatus 1 welds workpieces together by a method using a non-consumable electrode such as TIG welding or GTA welding, which performs welding while supplying a welding wire. On the other hand, the configuration of the aftershield jig included in the welding device described in this embodiment is also applicable to welding devices using consumable electrodes such as MIG welding, MAG welding, GMA welding, etc. It is something.

That is, as shown in FIG. 1, the welding apparatus 1 of this embodiment forms a welding arc while moving relatively along the abutting ends of the workpieces 80 (80) in the welding progress direction. (80) a welding torch 2 that forms a high-temperature molten pool (not shown) therebetween, and a shield gas nozzle 3 that is arranged downstream of the welding torch 2 in the welding direction Y and injects shielding gas toward the molten pool. , a monitoring imaging section 4 which is arranged downstream of the shielding gas nozzle 3 in the welding direction Y and captures an image of the state of the molten pool from the downstream side; It is generally configured to include an after-shield jig 10 that is arranged in this order from the upstream side to the downstream side and fixed together.

[Work (object to be welded)]
As shown in FIG. 1, the workpiece 80 is an object to be welded by gas-shielded arc welding by the welding apparatus 1 of the present embodiment, and is, for example, a metal or non-ferrous metal such as an automobile part or a building member. An example of such a structure is a structure in which a base material is used as a base material, and more specifically, a workpiece 80 made of a cylindrical steel pipe as shown in the illustrated example is mentioned.
Although detailed illustrations are omitted in FIG. 1 etc., the workpiece 80 exemplified in this embodiment is made by, for example, butting the ends (butting ends 81) of cylindrical steel pipes against each other. A weld bead is formed by welding between the two. That is, in FIG. 1, the workpieces 80 that are butted against each other are in a state in which the front side and the rear side overlap, so the workpieces 80 are individually represented by imaginary lines.

[Configuration of welding equipment]
The welding device 1 includes a welding torch 2, a shield gas nozzle 3, a monitoring imaging section 4, and an aftershield jig 10 for fixing the welding torch 2, shielding gas nozzle 3, and monitoring imaging section 4 together, as described above. , is provided. In addition, the illustrated welding apparatus 1 includes a wire supply section 5 that supplies the welding wire W toward the vicinity of the tip of the electrode 22 provided in the welding torch 2, and a wire supply section 5 that supports the welding torch 2 and the wire supply section 5. A casing 60 provided in the casing 60 is provided.

Furthermore, although not shown in FIG. 1 etc., the welding apparatus 1 includes a gas supply unit for supplying shielding gas to the shielding gas nozzle 3 described above, and a welding current to the welding torch 2 and workpiece 80. It consists of a welding power source for supplying

The casing 60 provided in the welding apparatus 1 of this embodiment supports the welding torch 2 and the wire supply section 5, as described above. The illustrated case 60 supports the wire supply section 5 by a wire supply section support arm 61, and the welding torch 2 is attached to the lower part 60a side. Further, in the illustrated example, the wire supply section support arm 61 is configured to be able to adjust the supply angle of the welding wire W to be supplied to the tip side of the electrode 22.

Further, the illustrated case 60 is provided with a pair of rotatable rollers 62, 62 that come into contact with a workpiece 80 made of a cylindrical steel pipe or the like. By a pair of rollers 62, 62 coming into contact with the surface of the workpiece 80 and rotating synchronously, for example, it becomes possible to maintain the distance between the electrode 22 provided in the welding torch 2 and the workpiece 80 within an optimum range. At the same time, the torch posture during welding is also stabilized.

The wire supply unit 5 is provided upstream of the welding torch 2 in the welding progress direction Y shown in FIG. The welding wire W unwound from the wound state is fed at a predetermined feeding speed.

As described above, the welding torch 2 forms a welding arc along the abutting ends 81 of the workpieces 80 (80) while moving relatively in the welding direction Y shown in FIG. A high temperature molten pool is formed between 80° and 80°. In the illustrated example, the welding torch 2 is configured to move relatively in the welding progress direction Y as the workpiece 80 (80) made of a steel pipe rotates.

The illustrated welding torch 2 includes an electrode 22 having a contact tip at its tip, and a welding current supplied from a welding power source (not shown) is supplied to the welding wire W via the electrode 22.
The welding apparatus 1 of the example described in this embodiment employs a non-consumable electrode method, and an arc is formed between the welding current supplied from the electrode 22 and the workpiece 80 made of a metal material.

Further, although detailed illustration is omitted, the space between the welding torch 2 and the electrode 22 inside the shield case 21 is used as a shield gas supply path, and the shield gas supplied from the above-mentioned gas supply section is used as a gas supply path. By being injected from the injection port 23, the welding arc is protected from the atmosphere and the shielding gas becomes the welding arc itself.

The welding arc formed by the welding torch 2 melts the welding wire W, thereby forming a droplet at the tip of the welding wire W. Then, this droplet separates from the tip of the welding wire W under the external force exerted by the electrode 22 and transfers to the base material of the workpiece 80, thereby performing welding and forming a weld bead.

The welding torch 2 is configured to be able to freely weld the workpiece 80 by, for example, operation in a three-dimensional direction using a robot system or a manipulator (not shown).

Further, although not shown in FIG. 1, welding current is supplied from the welding power source to not only the welding torch 2 but also the workpiece 80 via the ground cable.

Note that the welding torch 2 may be inserted through a cylindrical insulating adapter 18 into a torch fixing part 11 of an after-shield jig 10, the details of which will be described later, as in the example shown in FIG. More preferred. In this way, the welding torch 2 is first inserted into the insulating adapter 18, and the insulating adapter 18 is inserted and fixed into the torch fixing part 11 of the after-shield jig 10. It is possible to prevent the supplied high-frequency current from flowing to the monitoring imaging section 4, which will be described later. Further, by providing the insulating adapter 18, heat conduction from the welding torch 2 to the after-shield jig 10 can be suppressed. This can prevent the surveillance imaging unit 4, which is a delicate camera, from being damaged by high frequency current, heat, or the like.
Bakelite can be used as a material for the above-mentioned insulating adapter 18 from the viewpoints of electrical insulation, heat resistance, and the like.

As described above, the shield gas nozzle 3 is arranged downstream of the welding torch 2 in the welding progress direction Y shown in FIG. 1, and injects the shield gas toward a molten pool (not shown). That is, the shield gas nozzle 3 jets after-shield gas toward the molten pool from the downstream side in the welding progress direction Y.
Shield gas is supplied to the shield gas nozzle 3 from a gas supply section (not shown) through a gas inlet 31 provided in an after-shield jig 10, the details of which will be described later.

The shield gas nozzle 3 is not particularly limited, and gas nozzles commonly used in this field can be used without any restrictions.
On the other hand, as shown in the example shown in FIG. 5, the shielding gas nozzle 3 may be equipped with a diffusion nozzle at its tip that diffuses and sprays the shielding gas, thereby improving the shielding properties of the molten pool by effectively diffusing the shielding gas. It is more preferable from the viewpoint that the oxidation of the weld pool can be suppressed reliably and a good weld bead can be formed.

The gas supply unit (not shown) supplies shielding gas to the shielding gas supply path of the welding torch 2 and the shielding gas nozzle 3, and includes, for example, a gas supply source (not shown), a pressure reducer, a solenoid valve, and It is configured with a flow rate adjustment valve, etc.
As the gas supply source (not shown), for example, a cylinder filled with shielding gas under high pressure (for example, about 15 MPa) can be used.

The type of shielding gas can be selected as appropriate depending on the material that constitutes the workpiece 80.
When the material of the work 80 is carbon steel or stainless steel, for example, carbon dioxide gas, a mixed gas of argon and carbon dioxide, a mixed gas of argon and oxygen, a mixed gas of argon, helium, and carbon dioxide, A mixed gas of argon, helium, and oxygen can be used.
Furthermore, when the material of the workpiece 80 is aluminum or aluminum alloy, the shielding gas can be selected depending on the thickness of the workpiece 80, such as argon gas, mixed gas of argon and helium (helium-rich or argon-rich mixed gas) gas) etc. can be used.
On the other hand, if the material of the workpiece 80 is stainless steel, a mixed gas of argon and hydrogen, a mixed gas of argon, helium, and hydrogen, a mixed gas of argon and nitrogen, a mixed gas of argon, helium, and nitrogen, etc. may be used. I can do it.

The pressure reducer is, for example, installed at the outlet of a gas supply source containing high-pressure shielding gas, and is used to reduce the pressure of the shielding gas, and may be a one-stage pressure reducer or a two-stage pressure reducer as necessary. You can select and adopt any of them. For example, when the pressure of the shielding gas contained in the gas supply source is 15 MPa, the pressure reducer reduces the pressure of the shielding gas led out from the gas supply source to about 0.2 MPa, for example.

The electromagnetic valve is provided at any position on the line that supplies shielding gas from the gas supply source to the welding torch 2 and the shielding gas nozzle 3, and starts or stops the supply of the shielding gas. As the electromagnetic valve, any one commonly used in this field can be employed without any restriction.

The flow rate adjustment valve is arranged between a solenoid valve (not shown) and the welding torch 2 and the shielding gas nozzle 3 on a line that supplies shielding gas from the gas supply source to the welding torch 2 and the shielding gas nozzle 3 . As the flow rate regulating valve, any regulating valve can be used without any restriction as long as it is capable of restricting the flow rate of the shielding gas; for example, a needle valve can be used.

In the welding apparatus 1 of the present embodiment, a flow rate adjustment valve is further provided on the shield gas supply line located between the welding torch 2 and the shield gas nozzle 3 to control the flow rate of the shield gas that has passed through the flow rate adjustment valve. A flow meter (not shown) may be provided for measurement.

Note that the electromagnetic valve and the flow rate regulating valve described above are electrically connected to a welding control section (not shown) and are controlled by this welding control section. That is, the welding control section is electrically connected to the wire supply section 5, the electromagnetic valve, the flow rate regulating valve, the flow meter, etc., and controls the overall operation of the welding device 1. The welding control section includes, for example, a storage area and a control area (not shown). The storage area stores programs and the like for controlling the welding control section. The control area controls the entire welding apparatus 1 based on a program stored in the storage area.

As described above, the monitoring imaging unit 4 is arranged on the downstream side of the shield gas nozzle 3 in the welding progress direction Y shown in FIG. 1, and images the state of the molten pool (not shown) from the downstream side. As shown in FIGS. 1 and 2, the monitoring imaging unit 4 included in the welding apparatus 1 of the present embodiment is a camera body that includes an image sensor (not shown) and a lens barrel (lens) 43. 41, and a cylindrical lens cover 42 which is disposed on the entrance surface side of the lens barrel 43 and has an internal space in which the lens barrel 43 can image the molten pool. The illustrated surveillance imaging unit 4 has a configuration in which a lens barrel 43 protruding from a camera body 41 is covered with a lens cover 42 . By imaging the state of the molten pool with the monitoring imaging unit 4 from the downstream side in the welding progress direction Y, the welding state can be monitored with high precision.

Further, in the example shown in FIG. 1 etc., an insulating tube 7 is provided which is disposed at any position between the lens barrel 43 in the surveillance imaging unit 4 and the camera imaging port 14 of the after-shield jig 10. There is. The insulating tube 7 is a cylindrical member having an internal space in which the molten pool can be imaged by the lens barrel 43, and in the illustrated example, it is screwed to the tip of the lens cover 42 via a camera connection adapter 44. ing.

The camera main body 41 has an image sensor made of, for example, a CCD or a CMOS sensor inside, and photoelectrically converts light received by the image sensor and outputs it as an electrical image signal. As a result, the surveillance imaging unit 4 can display an image on an external monitor via an external connection terminal 45 connected to the camera body 41, such as a BNC terminal or an RCA terminal, or display an image on an external storage device. It is configured to be able to record images.
In addition, the surveillance imaging unit 4 is supplied with power via an unillustrated power supply (AC) adapter connected to the camera body 41, and can perform various operations via a wired or wireless remote control. It is composed of

The camera body 41 houses the above-mentioned image sensor and the like in a housing made of non-ferrous metal or metal such as aluminum alloy or magnesium alloy, or heat-resistant and flame-retardant resin, and in the illustrated example, The overall structure is approximately rectangular box-shaped.

The lens barrel (lens) 43 is, for example, a single-focus lens configured by a plurality of lenses (not shown) arranged inside the lens barrel (lens). Although detailed illustrations of the lens barrel 43 are omitted, for example, focus adjustment can be performed by moving some of the lenses in the optical axis direction. Further, in the lens barrel 43, it is possible to perform exposure adjustment using a diaphragm (not shown) disposed inside the lens barrel 43. Note that the lens barrel 43 is not limited to the above-mentioned single focus lens, but may also be a zoom lens that changes magnification by moving a part of the lens in the optical axis direction.

The lens cover 42 is made of, for example, a nonferrous metal or metal such as an aluminum alloy or a magnesium alloy, or a heat-resistant and flame-retardant resin. The lens cover 42 is formed into a generally cylindrical shape so as to correspond to the lens barrel 43 which has a generally cylindrical shape as a whole. Further, the lens cover 42 has a larger diameter on the base end side, that is, on the camera body 41 side, and has a smaller diameter on the distal end side than the base end side.

In this embodiment, it is preferable that the camera body 41 and the lens cover 42 are configured to be detachable, as in the surveillance imaging unit 4 illustrated in FIG. 2 . This makes it possible to replace the lens barrel 43, adjust the focus, adjust the aperture, etc. without taking out the image sensor from inside the camera body 41, so the shooting distance from the welding point can be kept constant. It is possible to easily adjust the photographing conditions by the monitoring image capturing section 4 while keeping the same state.

Further, according to the welding apparatus 1 of the present embodiment, since the insulating cylinder 7 having the above-described configuration is provided, the high-frequency current supplied to the electrode 22 can be transmitted to the monitoring and imaging section as in the case of the insulating adapter 18 described above. 4 can be prevented. Further, by providing the insulating tube 7, heat conduction from the welding torch 2 to the monitoring imaging section 4 can be suppressed. Therefore, similarly to the above, it is possible to prevent the surveillance imaging unit 4, which is a delicate camera, from being damaged by high frequency current, heat, or the like.
As with the case of the insulating adapter 18, from the viewpoint of electrical insulation and heat resistance, the material of the insulating cylinder 7 as described above may be, for example, Bakelite, ceramics, polyether ether ketone (PEEK), or super heat-resistant polyimide molding. (Sepura (registered trademark)), epoxy glass, etc. can be used.
On the other hand, in the case of touch-start TIG welding, MAG welding, and MAG welding in which no high-frequency current is generated during arc start, the material of the insulating tube 7 may be, for example, metal, nonferrous metal, or the like.

In the welding apparatus 1 of this embodiment, the monitoring imaging section 4 may further include a filter unit 46, as in the example shown in FIG. The filter unit 46 is an optical filter that is made up of, for example, an ND filter or the like, and is attached to the front side of the lens barrel 43 (lens cover 42). In the illustrated example, the filter unit 46 is arranged between the lens cover 42 and the camera connection adapter 44. Note that in this embodiment, since the filter unit 46 is not an essential component, it is also possible to use the filter unit 46 with it removed.

Note that, as the above-mentioned surveillance imaging unit 4, for example, a camera unit as disclosed in Japanese Patent Application Laid-open No. 2020-042241 can be employed without any restrictions.

The after-shield jig 10 has the above-described welding torch 2, shield gas nozzle 3, and monitoring imaging unit 4 arranged in this order from the upstream side to the downstream side in the welding progress direction Y shown in FIG. It is fixed in one piece.
The after-shield jig 10 includes a torch fixing part 11 to which the welding torch 2 is fixed, a nozzle fixing part 12 to which the shield gas nozzle 3 is fixed (see FIG. 5), and a connecting fitting 13 to fix the monitoring imaging part 4. Equipped with The torch fixing part 11, the nozzle fixing part 12, and the connecting fitting 13 are arranged in this order from the upstream side to the downstream side in the welding direction Y.
Further, the illustrated after-shield jig 10 is supported by the casing 60 of the welding device 1 via the welding torch 2 fixed to the nozzle fixing part 12.

Further, the illustrated after-shield jig 10 is disposed on the side wall 10c so as to face the lens barrel 43 of the monitoring imaging section 4, and the camera imaging camera has an opening at a position where the lens barrel 43 can image the molten pool. A port 14 is provided.

The torch fixing part 11 is disposed at an upstream position in the welding progress direction Y in the jig main body 10A, and is provided as a cylindrical hole passing through the jig main body 10A. In the example shown in FIG. 1, the welding torch 2 is inserted into the cylindrical insulating adapter 18, and in this state is inserted and fixed to the torch fixing part 11 (see also FIGS. 2, 5, etc.) ).

The nozzle fixing part 12 is arranged at a position downstream of the torch fixing part 11 in the welding progress direction Y in the jig main body 10A, and although detailed illustration is omitted in FIGS. Like the fixing part 11, it is provided as a cylindrical hole passing through the jig main body 10A. Further, the nozzle fixing part 12 is provided in a recess 10d provided in the lower surface 10b of the jig main body 10A at a position where the tip of the shield gas nozzle 3 does not protrude from the lower surface 10b of the jig main body 10A.

The connecting fitting 13 is for fixing the after-shield jig 10 and the surveillance imaging unit 4 as an integral structure, and in the example shown in FIGS. 1 and 2, it is attached to the upper surface 10a of the jig main body 10A. It is composed of a base body 13a and a support lever 13b movably attached to the base body 13a by a support shaft 13c.
Further, the illustrated after-shield jig 10 has a configuration in which the angle of the support lever 13b that supports the surveillance imaging section 4 is variable, and the imaging direction of the surveillance imaging section 4 can be changed. .

Further, as shown in the example shown in FIG. 3, the after-shield jig 10 used in this embodiment has a lens barrel 43 of the surveillance imaging unit 4 attached to the side wall 10c of the nozzle fixing part 12 to which the shield gas nozzle 3 is fixed. A camera imaging aperture 14 is provided which is arranged to face each other and opens at a position where the molten pool can be imaged by a lens barrel 43.
In this way, by providing the camera imaging port 14 in the after-shield jig 10, the monitoring imaging unit 4 can capture the molten pool through the recess 10d shown in FIG. It becomes possible to image and monitor.

In this embodiment, as described above, the after-shield jig 10 is integrated with the surveillance imaging unit 4 via the connecting fitting 13, so that the imaging conditions by the surveillance imaging unit 4 can be adjusted once. By adjusting to the optimal conditions, subsequent readjustment is not necessary.

In addition, when changing the imaging direction (angle) of the monitoring imaging unit 4 by adjusting the support lever 13b of the connecting fitting 13, this angle is 0 to 0 with respect to the liquid level of the molten pool, that is, the tangent to the cylindrical workpiece 80. A range of 45° is preferred. On the other hand, this is not the case, for example, when performing refraction imaging using a mirror, a prism, or the like.

In addition, on the upper surface 10a of the jig main body 10A in the after-shield jig 10 used in this embodiment, a gas inlet 31 for supplying shield gas toward the shield gas nozzle 3 fixed to the nozzle fixing part 12 is provided. installed.
Furthermore, the upper surface 10a of the jig main body 10A of the after-shield jig 10 is provided with a cooling water inlet 17a and a cooling water outlet 17b through which cooling water for cooling the entire after-shield jig 10 is introduced. There is.

The material of each member constituting the after-shield jig 10 is not particularly limited, and for example, metal materials with excellent heat resistance etc. that have been conventionally used in this field, such as stainless steel, may be used without any restrictions. is possible.

Further, as shown in the example shown in FIG. 3, the after-shield jig 10 provided in the welding apparatus 1 of the present embodiment includes at least a heat shield disposed to shield between the monitoring imaging unit 4 and the molten pool. A configuration including a plate 16 may also be adopted. The material for such a heat shield plate 16 is not particularly limited, and a metal plate or the like having excellent heat resistance etc. can be used without any restrictions.
By providing the heat shield plate 16 as described above, it is possible to shield and protect the insulating cylinder 7, lens cover 42, camera connection adapter 44, etc. from the heat generated by the arc light and the molten pool. .

In addition, in the welding apparatus 1 of this embodiment, when a configuration is adopted in which the heat-resistant glass 15 is arranged so as to cover the camera imaging aperture 14 as in the example shown in FIG. 4, the heat-resistant glass 15 is supplied from the downstream side. This allows the shielding gas to effectively shield the molten pool.
On the other hand, in this embodiment, by adopting a configuration in which a diffusion nozzle is provided at the tip of the shield gas nozzle 3 as described above, even when the heat-resistant glass 15 as described above is not provided, the molten pool can be prevented. You can obtain the effect of effectively shielding.

When the monitoring imaging unit 4 is provided on the downstream side (rear side) in the welding progress direction Y as in the welding apparatus 1 of this embodiment, the gas shield nozzle generally obstructs imaging, making it difficult to accurately monitor the welding state. becomes difficult to do. On the other hand, the welding apparatus 1 of the present embodiment installs the welding torch 2, shield gas nozzle 3, and monitoring imaging unit 4 in this order from the upstream side to the downstream side in the welding progress direction Y. By providing the aftershield jig 10 that is arranged and fixed together, it is possible to image the molten pool and weld bead with high precision using the monitoring imaging unit 4 without being obstructed by other members, etc. become.

Further, according to the present embodiment, by providing the above-described after-shield jig 10, it is possible to effectively suppress, for example, the influence of the high-frequency current supplied to the welding torch 2 on the monitoring imaging unit 4. Furthermore, by providing the after-shield jig 10, the influence of the heat generated by the welding torch 2, the heat generated from the molten pool and the weld bead, and furthermore the heat generated from spatter generated by welding is not exerted on the monitoring imaging unit 4. can be effectively suppressed. This makes it possible to prevent the surveillance imaging unit 4, which is a delicate camera, from being damaged by high frequency current or high temperature.

<Welding method>
Next, the welding method of this embodiment will be described with appropriate reference to the same drawings as above.
The welding method of this embodiment is a method of welding works 80 (80) together by forming a weld bead by gas-shielded arc welding using the welding apparatus 1 of this embodiment described above.
In addition, in the following description, the detailed description of the welding process already explained in the description of the above-mentioned welding apparatus 1 may be omitted.

In the welding method of this embodiment, first, a pair of workpieces 80 (80) are set so that their abutting ends 81 are abutted against each other.
Next, a pair of rollers 62, 62 that rotate and support the work 80 (80) are brought into contact with the surface of the work 80 (80).

Next, the welding torch 2, the shield gas nozzle 3, and the monitoring imaging unit 4 are aligned in the three-dimensional direction by a robot system or a manipulator (not shown) in the welding device 1, so that the positions of the welding torch 2, the shield gas nozzle 3, and the monitoring imaging unit 4 are aligned with the positions of the abutted ends 81. , move the after-shield jig 10.

Next, while rotating the workpiece 80 (80) in the welding progress direction Y at a predetermined speed, the welding wire W is supplied from the wire supply section 5 toward the vicinity of the tip of the electrode 22 of the welding torch 2. At this time, the welding wire W is supplied to an optimal position near the tip of the electrode 22 by adjusting the supply angle of the welding wire W using the wire supply section support arm 61.

Then, a high-frequency current is applied to the welding torch 2 to form a welding arc and the welding wire W is melted, thereby sequentially forming a molten pool along the abutting end portion 81. At the same time, shielding gas is injected from the gas injection port 23 of the welding torch 2 toward the molten pool, and after-shielding gas is injected from the shielding gas nozzle 3 toward the molten pool.

At this time, in the welding method of this embodiment, the monitoring imaging unit 4 monitors the welding state while imaging the formed molten pool and weld bead.

By the above-described procedure, the works 80 (80) can be welded together using the welding apparatus 1 of this embodiment.
According to the welding method of this embodiment, by using the welding device 1, the molten pool and weld bead can be imaged with high precision using the monitoring imaging unit 4, as described above, without being obstructed by other members etc. Furthermore, it becomes possible to easily optimize welding conditions using this imaging data.
In addition, according to the welding method of this embodiment, by using the welding device 1, the effects of the high frequency current supplied to the welding torch 2, the heat generated by the welding torch 2, and the heat generated from the molten pool and weld bead, as described above. It is possible to effectively suppress the influence of the heat caused by the heat generated by the welding, and further by the heat generated by the spatter generated by welding, from reaching the monitoring imaging unit 4.

<Other forms>
The embodiments of the present invention have been described above in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and the present invention includes designs and the like without departing from the gist of the invention. included.

The welding device of the present invention can monitor the welding state with high precision, and can effectively suppress oxidation of the molten pool while forming a good weld bead and welding workpieces together. . Therefore, the present invention is very suitable for use in, for example, gas-shielded arc welding of structures (objects to be welded) using metals, non-ferrous metals, etc. as base materials.

1... Welding device 2... Welding torch 21... Shield case 22... Electrode 23... Gas injection port 3... Shield gas nozzle 31... Gas inlet 4... Surveillance imaging unit 41... Camera body 42... Lens cover 43... Lens barrel (lens)
44... Camera connection adapter 45... Terminal for external connection 46... Filter unit 5... Wire supply section 60... Housing 60a... Lower part 61... Wire supply section support arm 7... Insulation cylinder 10... After shield jig 10A... Jig main body 10a ...Top surface 10b...Bottom surface 10c...Side wall 10d...Concave portion 11...Torch fixing part 12...Nozzle fixing part 13...Connection fitting 13a...Base body 13b...Support lever 13c...Support shaft 14...Camera imaging port 15...Heat-resistant glass 16...Heat shield Plate 17a...Cooling water inlet 17b...Cooling water outlet 18...Insulation adapter 80...Workpiece (pair of workpieces)
81...Butt end W...Welding wire Y...Welding direction

Claims (10)

A welding device that welds workpieces together by forming a weld bead by gas-shielded arc welding,
a welding torch that forms a high-temperature molten pool between the workpieces by forming a welding arc while moving relatively in the welding progress direction along the abutting ends of the workpieces;
a shielding gas nozzle that is disposed downstream of the welding torch in the welding progress direction and injects shielding gas toward the molten pool;
a monitoring imaging unit that is disposed downstream of the shield gas nozzle in the welding progress direction and captures an image of the state of the molten pool from the downstream side;
an after-shield jig that arranges the welding torch, the shield gas nozzle, and the monitoring imaging unit in this order from the upstream side toward the downstream side in the welding progress direction and fixes them together ;
The after-shield jig is a camera that is disposed on a side wall of a nozzle fixing part to which the shield gas nozzle is fixed so as to face a lens of the monitoring imaging part, and has an opening at a position where the lens can image the molten pool. A welding device characterized by having an imaging port . 2. The welding apparatus according to claim 1, wherein the monitoring imaging section and the after-shield jig have an integral structure via a connecting metal fitting. 3. The welding apparatus according to claim 2, wherein the connecting fitting has a variable angle of a support lever that supports the monitoring imaging section, and the imaging direction of the monitoring imaging section can be changed. A claim characterized by comprising an insulating cylinder disposed at any position between the lens and the camera imaging port in the monitoring imaging section and having an internal space in which the molten pool can be imaged by the lens. The welding device according to any one of items 1 to 3 . The welding device according to any one of claims 1 to 4, wherein a heat-resistant glass is arranged to cover the camera imaging port. The welding torch according to any one of claims 1 to 5 , wherein the welding torch is inserted into the torch fixing part of the aftershield jig via a cylindrical insulating adapter. Welding equipment. The welding apparatus according to any one of claims 1 to 6 , wherein the shield gas nozzle includes a diffusion nozzle at its tip that diffuses and sprays the shield gas. Further, the after-shield jig includes at least a heat shield plate arranged to shield between the monitoring imaging section and the molten pool. The welding device according to item 1. The monitoring imaging unit includes a camera body including the lens, and a cylindrical lens cover disposed on the incident surface side of the lens and having an internal space in which the molten pool can be imaged by the lens, The welding device according to any one of claims 1 to 8 , wherein the camera body and the lens cover are configured to be detachable. A welding method for welding workpieces by forming a weld bead by gas-shielded arc welding using the welding apparatus according to any one of claims 1 to 9 .

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