JP2023023632A - Welding device and welding method - Google Patents

Abstract

To provide a welding device and a welding method which can monitor a welded state with high accuracy, and can form an excellent welding bead while effectively suppressing a molten pool from getting oxidized to weld work-pieces to each other.SOLUTION: A welding device comprises: a welding torch 2 that forms a high-temperature molten pool between work-pieces 80 by forming a welding arc while relatively moving in a welding direction along butted end parts 81 of the work-pieces 80; a shield gas nozzle 3, arranged at a downstream side of the welding torch 2 in the welding direction Y, which jets shield gas towards the molten pool; a monitoring/photographing part 4, arranged at a downstream side of the shield gas nozzle 3 in the welding direction Y, which photographs a state of the molten pool from the downstream side; and an after-shield jig 10 that enables the welding torch 2, the shield gas nozzle 3 and the monitoring/photographing part 4 to be arranged and integrally fixed in this order, from an upstream side towards a downstream side in the welding direction.SELECTED DRAWING: Figure 1

Description

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

2. Description of the Related Art Conventionally, arc welding, which is advantageous in terms of cost and versatility, has been widely used as a method for welding structures (workpieces to be welded) using metals, non-ferrous metals, etc. as base materials. As such arc welding, for example, TIG welding (Tungsten Inert Gas welding) using a non-consumable electrode, or gas shielded arc welding such as GTA welding (Gas Tungsten Arc welding), which is plasma arc welding, is used. there is 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. .

Gas-shielded arc welding is not limited to the welding applications described above.
Since it can also be used for brazing, joining, cutting, thermal spraying, melting furnaces, etc. for workpieces, such applications are treated as one form of welding in the present invention.

Generally, in gas shielded arc welding as described above, an arc is generated between an electrode and a work to be welded (base metal) by a welding torch, and the work to be welded is melted by the heat of this arc to form a molten pool. Welding is performed while During welding, shielding gas is jetted out from nozzles arranged to surround the electrode. Welding is performed while protecting the

As described above, as a device for performing gas-shielded arc welding while injecting shielding gas into the molten pool during welding, for example, a shielding gas nozzle for supplying shielding gas is arranged directly above the molten pool. is known (see, for example, Patent Document 1).
A welding apparatus has also been proposed in which a shield gas nozzle is disposed downstream of the welding torch in the direction of welding progress, and which performs after-shielding with a shield gas (see, for example, Patent Document 2).

Here, conventionally, for example, in order to perform various adjustments for the purpose of improving welding conditions and monitor the welding state, a camera is used to image the welded portion and its surroundings, and the state of the welding torch and the welded portion Observation of the state of
For example, the welding apparatus disclosed in the above-mentioned Patent Document 1 has a configuration in which a camera is arranged directly above the gas shield nozzle.
Further, in the welding apparatus disclosed in Patent Document 2, a camera is installed on the upstream side of the welding torch in the welding advancing direction, and is configured to capture an image of the molten pool from the upstream side.

Japanese Patent No. 6524766 JP-A-2007-136461

However, in the case of the configuration in which the camera is arranged directly above the gas shield nozzle as in Patent Document 1, there is a problem that the gas shield nozzle interferes with imaging, and it is difficult to accurately monitor the welding state.
For this reason, for example, as in the welding apparatus disclosed in Patent Document 2, by combining a clamp arm, a shaft, a holder, etc. for fixing the camera, the camera can be observed from an oblique direction. Must be placed and fixed. However, in the case of adopting a configuration in which a camera is arranged and fixed in combination with a clamp arm or the like as in Patent Document 2, in order to perform optimal imaging that can monitor the welded portion, for example, adjustment of the camera angle, There is a problem that skillful techniques are required for adjustment of the photographing distance, lens focus adjustment, aperture adjustment, and the like. Furthermore, as in Patent Document 2, in the case of a configuration in which the camera is installed upstream of the welding torch in the direction of welding progress, the welding torch may interfere with imaging. There is a problem that it is difficult to accurately perform

On the other hand, as in the welding apparatus disclosed in Cited Document 2, when adopting a configuration in which shield gas is supplied downstream in the direction of welding progress, a jig such as a shield box is arranged downstream of the welding torch. is required. However, in this case, it becomes difficult to perform imaging from the downstream side in the welding progress direction, and there is a problem that the molten pool cannot be observed accurately.

The present invention has been made in view of the above problems, and is capable of monitoring the welding state with high accuracy, effectively suppressing the oxidation of the molten pool, forming a good weld bead, and joining the workpieces together. An object of the present invention is to provide a welding device and a welding method capable of 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 apparatus for welding works together by forming a weld bead by gas shielded arc welding, wherein relative movement in the welding progress direction is performed along the butt ends of the works. A welding torch that forms a high-temperature molten pool between the workpieces by forming a welding arc while welding, and a welding torch that is arranged downstream of the welding torch in the welding progress direction and injects shielding gas toward the molten pool. a shielding gas nozzle arranged downstream of the shielding gas nozzle in the direction of welding progress 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. are arranged in this order from the upstream side to the downstream side in the welding advancing direction, and an after-shield jig for integrally fixing them.

Further, the invention according to claim 2 is the welding apparatus according to claim 1, wherein the monitoring imaging unit and the after-shield jig are integrally structured via a connecting metal fitting. It is a welding device that

Further, the invention according to claim 3 is the welding apparatus according to claim 2, wherein the connecting fitting has a variable angle of a support lever that supports the monitoring imaging unit. The welding device is 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 is attached to a side wall of a nozzle fixing portion to which the shield gas nozzle is fixed, The welding device is characterized in that it has a camera imaging port that is arranged so as to face the lens of the monitoring imaging unit and that is open at a position where the lens can image the molten pool.

Further, the invention according to claim 5 is the welding device according to claim 4, wherein the welding device according to claim 4 is arranged at any position between the lens and the camera imaging opening in the monitoring imaging unit, The welding device is characterized by comprising an insulating cylinder having an internal space capable of imaging a molten pool.

Further, the invention according to claim 6 is the welding device 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 the torch fixing portion of the after shield jig. A welding device characterized by being 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 its tip for diffusing and jetting the shield gas. It is a welding device characterized by

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 unit and the molten pool. The welding device is characterized by comprising a heat shield plate arranged so as to shield the space.

Further, the invention according to claim 10 is the welding apparatus according to any one of claims 1 to 9, wherein the monitoring imaging unit comprises a camera main body including the lens, and an incident surface side of the lens. Welding characterized by comprising a cylindrical lens cover having an internal space in which the lens can capture an image of the molten pool, and wherein the camera body and the lens cover are detachably attached to each other. It is a device.

The invention according to claim 11 is 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 10.

ADVANTAGE OF THE INVENTION According to the welding apparatus according to the present invention, the welding state can be monitored with high accuracy, and it is possible to weld the workpieces by forming a good weld bead while effectively suppressing oxidation of the molten pool. It becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 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 illustrating a welding apparatus 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 apparatus shown in FIG. 1 is a diagram showing a monitoring imaging unit separated into a camera body and a lens cover. FIG. FIG. 3 is a schematic diagram for schematically explaining a welding apparatus and a welding method according to an embodiment of the present invention, showing an example in which the after shield jig shown in FIG. 2 is further provided with a heat shield plate and a filter unit; It is a perspective view showing. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for 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 opening provided in an after-shield jig. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for schematically explaining a welding apparatus and a welding method according to an embodiment of the present invention, showing a diffusion nozzle provided at the tip of a shield gas nozzle as seen from the bottom side of an after-shield jig; 1 is a schematic diagram; FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A welding apparatus and a welding method according to an embodiment to which the present invention is applied will now be described with reference to FIGS. 1 to 5 as appropriate. In addition, in the drawings used in the following description, in order to make it easier to understand the features of the present invention, there are cases where the characteristic parts are enlarged for convenience, and the dimensional ratios of each component are the same as the actual ones. Not necessarily. Also, the materials and the like exemplified in the following description are merely examples, and the present invention is not limited to them, and can be implemented with appropriate modifications within the scope of the invention.

<Welding device>
FIG. 1 is a schematic diagram showing an example of the overall configuration of a welding apparatus 1 of this embodiment, and FIG. 2 is a schematic diagram showing an enlarged main part of the welding apparatus 1 shown in FIG. 4 is a diagram showing the monitoring 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 aftershield jig 10 shown in FIG. 2 further includes a heat shield plate 16 and a filter unit 46. FIG.
FIG. 4 is a perspective view showing an example in which the heat-resistant glass 15 is arranged in the camera imaging port 14 provided in the aftershield jig 10. As shown in FIG.
FIG. 5 is a view of the after-shield jig 10 as seen from below, and is a schematic diagram showing the shield gas nozzle 3 which is a diffusion type nozzle.

The welding apparatus 1 shown in FIG. 1 welds workpieces 80 (80) by forming a weld bead (not shown) by gas-shielded arc welding. The welding apparatus 1 of the illustrated example welds workpieces by a method using a non-consumable electrode, such as TIG welding or GTA welding, in which welding is performed while a welding wire is being supplied. On the other hand, the configuration of the after-shield jig provided in the welding apparatus described in this embodiment is also applicable to welding apparatuses using consumable electrodes such as MIG welding, MAG welding, or GMA welding. It is.

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

[Work (object to be welded)]
As shown in FIG. 1, a workpiece 80 is an object to be welded by gas-shielded arc welding by the welding apparatus 1 of the present embodiment. as a base material, and more specifically, a workpiece 80 made of a cylindrical steel pipe as shown in the drawing.
Although detailed illustration is omitted in FIG. 1 and the like, the workpiece 80 exemplified in the present embodiment is, for example, a cylindrical steel pipe whose ends (butting ends 81) are butted against each other, and these ends are A weld bead is formed by welding between . That is, in FIG. 1, the workpieces 80 to be butted against each other are overlapped on the front side and the rear side, so the workpieces 80 are shown singly by imaginary lines.

[Configuration of Welding Device]
The welding apparatus 1 includes the welding torch 2, the shield gas nozzle 3, the monitoring imaging unit 4, and the after shield jig 10 for integrally fixing the welding torch 2, the shield gas nozzle 3, and the monitoring imaging unit 4 as described above. , provided. Moreover, in the welding apparatus 1 of the illustrated example, 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 the wire supply section 5 and the welding torch 2 are supported by and a housing 60 provided in.

Furthermore, although not shown in FIG. a welding power source for supplying a

The housing 60 provided in the welding device 1 of this embodiment supports the welding torch 2 and the wire feed section 5 as described above. The housing 60 in the illustrated example supports the wire feeder 5 with a wire feeder support arm 61 and has the welding torch 2 attached to the lower portion 60a side. In the illustrated example, the wire feeder support arm 61 is configured to be able to adjust the feed angle of the welding wire W fed to the tip side of the electrode 22 .

Further, the housing 60 in the illustrated example is provided with a pair of rotatable rollers 62, 62 which are in contact with a workpiece 80 made of a cylindrical steel pipe or the like. The pair of rollers 62, 62 contact the surface of the work 80 and rotate synchronously, so that the distance between the electrode 22 provided on the welding torch 2 and the work 80 can be maintained within an optimum range. At the same time, the torch posture during welding is also stabilized.

The wire feeder 5 is provided upstream of the welding torch 2 in the welding advancing direction Y shown in FIG. A welding wire W unwound from a wound state is supplied at a predetermined supply speed.

As described above, the welding torch 2 forms a welding arc while relatively moving in the welding advancing direction Y shown in FIG. A high-temperature molten pool is formed between 80 (80). In the illustrated example, the welding torch 2 is relatively moved in the welding advancing direction Y by rotating the workpiece 80 (80) made of a steel pipe.

The welding torch 2 of the illustrated example has 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 system, and the welding current supplied from the electrode 22 forms an arc with the workpiece 80 made of a metal material.

Although not shown in detail, the space between the welding torch 2 and the electrode 22 inside the shield case 21 serves as a shield gas supply path, and the shield gas supplied from the gas supply section described above is gas. By jetting 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 to form droplets at the tip of the welding wire W. As shown in FIG. Then, the droplets are subjected to an external force from the electrode 22, are separated from the tip of the welding wire W, and are transferred to the base material of the workpiece 80, thereby welding is performed and a weld bead is formed.

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

Although not shown in FIG. 1, welding current is supplied not only to the welding torch 2 but also to the workpiece 80 from the welding power source through the earth cable.

It should be noted that the welding torch 2 is inserted through a cylindrical insulating adapter 18 into a torch fixing portion 11 of an after-shield jig 10, which will be described later in detail, as in the example shown in FIG. more preferred. Thus, the welding torch 2 is first inserted into the insulation adapter 18, and the insulation adapter 18 is inserted and fixed to the torch fixing portion 11 of the after shield jig 10. It is possible to prevent the supplied high-frequency current from flowing to the monitoring imaging unit 4, which will be described later. Moreover, by providing the insulation adapter 18, heat conduction from the welding torch 2 to the after-shield jig 10 can be suppressed. As a result, it is possible to prevent the monitoring imaging unit 4, which is a delicate camera, from being damaged by high-frequency current, heat, or the like.
As the material of the insulating adapter 18 as described above, bakelite can be used from the viewpoint of electrical insulation and heat resistance.

As described above, the shield gas nozzle 3 is arranged on the downstream side of the welding torch 2 in the welding advancing direction Y shown in FIG. 1, and injects shield gas toward a not-shown molten pool. That is, the shield gas nozzle 3 ejects the after-shield gas from the downstream side in the welding advancing direction Y toward the molten pool.
A shield gas is supplied to the shield gas nozzle 3 from a gas supply unit (not shown) through a gas introduction port 31 provided in an after-shield jig 10 whose details will be described later.

The shield gas nozzle 3 is not particularly limited, and gas nozzles generally used in this field can be used without any limitation.
On the other hand, as the shield gas nozzle 3, as in the example shown in FIG. 5, if a diffusion nozzle that diffuses and jets the shield gas is provided at the tip, the shield gas can be effectively diffused to improve the shielding performance of the molten pool. It is more preferable from the viewpoint that it is possible to increase it further, to surely suppress the oxidation of the weld pool, and to form a good weld bead.

The gas supply unit (not shown) supplies the shield gas to the shield gas supply path of the welding torch 2 and the shield gas nozzle 3. For example, the gas supply source (not shown), pressure reducer, electromagnetic valve, and It is configured with a flow control valve and the like.
As a gas supply source (not shown), for example, a cylinder or the like filled with shielding gas at a high pressure (eg, about 15 MPa) can be used.

The type of shielding gas can be appropriately selected according to the material forming the workpiece 80 .
When the material of the workpiece 80 is carbon steel or stainless steel, for example, carbon dioxide gas, mixed gas of argon and carbon dioxide, mixed gas of argon and oxygen, mixed gas of argon, helium and carbon dioxide, A mixed gas of argon, helium, and oxygen or the like can be used.
Further, when the material of the workpiece 80 is aluminum or an aluminum alloy, the shielding gas can be selected according to the thickness of the workpiece 80. Argon gas, mixed gas of argon and helium (helium-rich or argon-rich mixed gas) gas) and the like can be used.
On the other hand, when the work 80 is made of 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. can be done.

The decompressor is provided, for example, at the lead-out portion of the gas supply source containing the high-pressure shielding gas, and reduces the pressure of the shielding gas. can be selected and adopted. 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 drawn out from the gas supply source to approximately 0.2 MPa, for example.

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

The flow control valve is arranged between an electromagnetic valve (not shown) and the welding torch 2 and the shield gas nozzle 3 on a line that supplies the shield gas from the gas supply source to the welding torch 2 and the shield gas nozzle 3 . As the flow control valve, any control valve can be adopted without any limitation as long as it is a valve capable of throttling the flow rate of the shielding gas. For example, a needle valve can be used.

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

The solenoid valve and the flow control valve described above are electrically connected to a welding control section (not shown) and controlled by this welding control section. That is, the welding control section is electrically connected to the wire supply section 5, the solenoid valve, the flow control valve, the flow meter, etc., and controls the overall operation of the welding device 1. FIG. The welding control section is composed of, for example, a storage area and a control area (not shown). The storage area stores programs and the like for controlling the welding control unit. The control area controls the entire welding apparatus 1 based on the 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 provided in the welding apparatus 1 of the present embodiment incorporates an imaging element (not shown) and the like, and a camera body provided with a lens barrel (lens) 43. 41 and a cylindrical lens cover 42 which is arranged on the incident surface side of the lens barrel 43 and has an internal space in which the image of the molten pool can be captured by the lens barrel 43 . The monitoring imaging unit 4 in the illustrated example is configured such that a lens barrel 43 protruding from a camera body 41 is covered with a lens cover 42 . By capturing an image of the state of the molten pool from the downstream side in the welding direction Y with the monitoring imaging unit 4, the welding state can be monitored with high accuracy.

In addition, in the example shown in FIG. 1 and the like, the insulating cylinder 7 is provided at any position between the lens barrel 43 in the monitoring imaging unit 4 and the camera imaging port 14 of the aftershield jig 10. there is The insulating cylinder 7 is a cylindrical member having an internal space that allows the lens barrel 43 to take an image of the molten pool. ing.

The camera body 41 has an image pickup device such as a CCD or CMOS sensor inside, photoelectrically converts the light received by the image pickup device, and outputs it as an electric image pickup signal. As a result, the monitoring imaging unit 4 can display an image on an external monitor or store an image on an external storage device via an external connection terminal 45 such as a BNC terminal or an RCA terminal connected to the camera body 41 . It is configured to be able to record (record) an image.
The monitoring imaging unit 4 is supplied with power via a power supply (AC) adapter (not shown) connected to the camera body 41, and can be operated via a wired or wireless remote controller. is configured to

The camera body 41 houses the above-described imaging element and the like in a housing made of, for example, a non-ferrous metal or metal such as an aluminum alloy or a magnesium alloy, or a heat-resistant and flame-retardant resin. As a whole, it is configured in a substantially rectangular box shape.

The lens barrel (lens) 43 is, for example, a single-focal lens composed of a plurality of lenses (not shown) arranged inside. Although the detailed illustration of the lens barrel 43 is omitted, for example, by moving some lenses among a plurality of lenses in the optical axis direction, it is possible to perform focus adjustment. Further, in the lens barrel 43, exposure adjustment can be performed by a diaphragm (not shown) disposed inside the lens barrel 43. FIG. Note that the lens barrel 43 is not limited to the above-described single focus lens, and may be a zoom lens that changes power by moving a part of the lenses in the optical axis direction.

The lens cover 42 is made of, for example, a non-ferrous metal such as an aluminum alloy or a magnesium alloy, a metal, or a heat-resistant and flame-retardant resin. The lens cover 42 is generally cylindrical as a whole so as to correspond to the generally cylindrical lens barrel 43 . The lens cover 42 has a large diameter on the base end side, ie, the camera body 41 side, and a smaller diameter on the tip end side than on the base end side.

In this embodiment, it is preferable that the camera main body 41 and the lens cover 42 are detachable like the monitoring imaging unit 4 illustrated in FIG. This makes it possible to replace the lens barrel 43, adjust the focus, and adjust the aperture without removing the image sensor from the inside of the camera body 41. In this state, it is possible to easily adjust the photographing conditions by the surveillance imaging unit 4. FIG.

Further, according to the welding device 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 is detected by the monitoring imaging unit as in the case of the insulating adapter 18 described above. 4 can be prevented. In addition, heat conduction from the welding torch 2 to the monitoring imaging unit 4 can be suppressed by providing the insulating cylinder 7 . Therefore, similarly to the above, it is possible to prevent the monitoring imaging unit 4, which is a delicate camera, from being damaged by high-frequency current, heat, or the like.
As for the material of the insulating cylinder 7 as described above, from the viewpoint of electrical insulation and heat resistance, as in the case of the insulating adapter 18, for example, bakelite, ceramics, polyetheretherketone (PEEK), super heat-resistant polyimide molding, etc. A body (Cepra (registered trademark)), epoxy glass, or the like can be used.
On the other hand, in the case of touch-start type TIG welding, MAG welding, and MAG welding in which high-frequency current is not generated at arc start, the insulating cylinder 7 can be made of, for example, metals, non-ferrous metals, or the like.

In the welding device 1 of the present embodiment, a configuration in which the monitoring imaging section 4 further includes a filter unit 46 may be adopted as in the example shown in FIG. The filter unit 46 is, for example, an ND filter or the like, and is an optical filter 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 . In this embodiment, since the filter unit 46 is not an essential component, it is possible to use the apparatus with the filter unit 46 removed.

It should be noted that, as the monitoring imaging section 4 as described above, 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 together.
The after shield jig 10 includes a torch fixing portion 11 to which the welding torch 2 is fixed, a nozzle fixing portion 12 (see FIG. 5) to which the shielding gas nozzle 3 is fixed, and a connecting metal fitting 13 to which the monitoring imaging portion 4 is fixed. Prepare. The torch fixing portion 11, the nozzle fixing portion 12, and the connecting fitting 13 are arranged in this order from the upstream side toward the downstream side in the welding advancing direction Y. As shown in FIG.
Further, the illustrated after-shield jig 10 is supported by the housing 60 of the welding device 1 via the welding torch 2 fixed to the nozzle fixing portion 12 .

The after shield jig 10 in the illustrated example is arranged on the side wall 10c so as to face the lens barrel 43 of the monitoring imaging unit 4, and the lens barrel 43 opens to a position where the molten pool can be imaged. A mouth 14 is provided.

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

The nozzle fixing part 12 is arranged at a position downstream of the torch fixing part 11 in the welding advancing direction Y in the jig body 10A. Similar to the fixing portion 11, it is provided as a cylindrical hole penetrating the jig body 10A. Further, the nozzle fixing portion 12 is provided in a recess 10d provided in the lower surface 10b of the jig 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 body 10A.

The connecting fitting 13 fixes the after shield jig 10 and the monitoring imaging unit 4 as an integral structure, and in the example shown in FIGS. 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 after shield jig 10 of the illustrated example is configured such that the angle of the support lever 13b that supports the monitoring imaging section 4 is variable, and the imaging direction of the monitoring imaging section 4 can be changed. .

Further, as in the example shown in FIG. 3, the after-shield jig 10 used in this embodiment includes a lens barrel 43 of the monitoring imaging unit 4 and a side wall 10c of the nozzle fixing unit 12 to which the shield gas nozzle 3 is fixed. A camera imaging port 14 is provided so as to face each other and is opened at a position where the lens barrel 43 can image the molten pool.
In this way, by providing the camera imaging port 14 in the aftershield jig 10, the molten pool by the monitoring imaging unit 4 can be detected through the concave portion 10d shown in FIG. can be imaged and monitored.

In the present embodiment, as described above, the after shield jig 10 is integrated with the monitoring imaging unit 4 via the connecting metal fittings 13, so that the imaging conditions of the monitoring imaging unit 4 can be changed once. By adjusting to the optimum conditions, subsequent readjustment becomes unnecessary.

Further, when the imaging direction (angle) of the monitoring imaging unit 4 is changed by adjusting the support lever 13b of the connecting fitting 13, this angle is 0 to A range of 45° is preferred. On the other hand, this is not the case when refraction imaging is performed using a mirror, prism, or the like, for example.

The upper surface 10a of the jig body 10A in the after shield jig 10 used in the present embodiment has a gas introduction port 31 for supplying shield gas toward the shield gas nozzle 3 fixed to the nozzle fixing portion 12. installed.
Further, the upper surface 10a of the jig main body 10A of the aftershield jig 10 is provided with a cooling water inlet 17a and a cooling water outlet 17b through which cooling water for cooling the entire aftershield jig 10 is introduced. there is

The material of each member constituting the after-shield jig 10 is not particularly limited, and for example, a metal material having excellent heat resistance and the like conventionally used in this field, such as stainless steel, may be adopted without any limitation. is possible.

Moreover, the after-shield jig 10 provided in the welding apparatus 1 of the present embodiment is, as in the example shown in FIG. A configuration with a plate 16 may be employed. The material of the heat shield plate 16 is not particularly limited, and a metal plate having excellent heat resistance and the like can be used without any limitation.
By providing the heat shield plate 16 as described above, it becomes possible to shield and protect the insulating cylinder 7, the lens cover 42, the camera connection adapter 44, etc. from the heat generated by the arc light and the molten pool. .

In addition, in the welding device 1 of the present embodiment, if a configuration in which the heat-resistant glass 15 is arranged so as to cover the camera imaging port 14 as in the example shown in FIG. Shielding gas can effectively shield the molten pool.
On the other hand, in the present embodiment, by adopting a configuration in which a diffusion nozzle is provided at the tip of the shield gas nozzle 3 as described above, the molten pool is formed even when the heat-resistant glass 15 as described above is not provided. An effect that can be effectively shielded can be obtained.

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 the present embodiment, the gas shield nozzle generally hinders the imaging, and the welding state can be monitored accurately. becomes difficult to do. On the other hand, the welding apparatus 1 of the present embodiment has the welding torch 2, the shield gas nozzle 3, and the monitoring imaging unit 4 as described above, arranged in this order from the upstream side to the downstream side in the welding advancing direction Y. By providing the after shield jig 10 that is arranged and fixed integrally, it is possible to image the molten pool and the weld bead with high accuracy using the monitoring imaging unit 4 without being obstructed by other members. become.

Further, according to the present embodiment, by providing the above-described aftershield jig 10, for example, it is possible to effectively suppress the influence of the high-frequency current supplied to the welding torch 2 from reaching the monitoring imaging section 4. FIG. Furthermore, by providing the after shield jig 10, the monitoring imaging unit 4 is not affected by the heat generated by the welding torch 2, the heat generated by the molten pool or the weld bead, and the heat generated by the spatter generated by welding. can be effectively suppressed. As a result, it is possible to prevent the monitoring 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 workpieces 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 described in the description of the welding apparatus 1 may be omitted.

In the welding method of the present embodiment, first, a pair of works 80 (80) are set so that their butt end portions 81 are butted against each other.
Next, a pair of rollers 62, 62 supporting the work 80 (80) while rotating is brought into contact with the surface of the work 80 (80).

Then, 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 butted ends 81 by three-dimensional operations by a robot system and a manipulator (not shown) in the welding device 1. , the after shield jig 10 is moved.

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

A high-frequency current is applied to the welding torch 2 to form a welding arc and melt the welding wire W, thereby sequentially forming a molten pool along the butt ends 81 . At the same time, the shield gas is injected from the gas injection port 23 of the welding torch 2 toward the molten pool, and the aftershield gas is injected from the shield gas nozzle 3 toward the molten pool.

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

Through the procedure described above, the workpieces 80 (80) can be welded together using the welding device 1 of the present embodiment.
According to the welding method of the present embodiment, by using the welding device 1, similarly to the above, the molten pool and the weld bead can be imaged with high accuracy using the monitoring imaging unit 4 without being obstructed by other members or the like. Furthermore, it is possible to easily optimize the welding conditions using this imaging data.
In addition, according to the welding method of the present embodiment, by using the welding apparatus 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 the weld bead are reduced as described above. It is possible to effectively suppress the influence of the heat generated by welding and the heat generated by the spatter generated by welding from reaching the monitoring imaging unit 4 .

<Other forms>
As described above, the embodiment of the present invention has been described in detail with reference to the drawings. included.

ADVANTAGE OF THE INVENTION The welding apparatus of this invention can monitor a welding state with high precision, forms a favorable weld bead, effectively suppressing oxidation of a molten pool, and can weld workpieces together. . Therefore, the present invention is very suitable for gas-shielded arc welding of structures (workpieces to be welded) using, for example, metals or non-ferrous metals as base materials.

DESCRIPTION OF SYMBOLS 1... Welding apparatus 2... Welding torch 21... Shield case 22... Electrode 23... Gas injection port 3... Shield gas nozzle 31... Gas introduction port 4... Surveillance imaging unit 41... Camera body 42... Lens cover 43... Lens barrel (lens)
44 Camera connection adapter 45 External connection terminal 46 Filter unit 5 Wire supply unit 60 Housing 60a Lower part 61 Wire supply unit support arm 7 Insulation tube 10 After shield jig 10A Jig body 10a Upper surface 10b Lower surface 10c Side wall 10d Recess 11 Torch fixing part 12 Nozzle fixing part 13 Connecting metal 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 Work (a pair of works)
81 ... Butt end W ... Welding wire Y ... Welding direction

Claims (11)

A welding device that welds workpieces by forming a weld bead by gas shielded arc welding,
A welding torch that forms a high-temperature molten pool between the works by forming a welding arc while relatively moving in the welding progress direction along the butted ends of the works,
a shield gas nozzle arranged downstream of the welding torch in the welding progress direction and configured to inject shield gas toward the molten pool;
a monitoring imaging unit disposed on the downstream side of the shield gas nozzle in the welding advancing direction and capturing an image of the state of the molten pool from the downstream side;
an after shield jig for arranging and integrally fixing the welding torch, the shield gas nozzle, and the monitoring imaging unit in this order from the upstream side to the downstream side in the welding progress direction;
A welding device comprising: 2. The welding device according to claim 1, wherein said monitoring imaging unit and said after-shield jig are integrally constructed via a connecting fitting. 3. The welding device according to claim 2, wherein the connecting fitting has a variable angle of a support lever that supports the monitoring imaging unit, so that the imaging direction of the monitoring imaging unit can be changed. The after shield jig is arranged on the side wall of the nozzle fixing portion to which the shield gas nozzle is fixed so as to face the lens of the monitoring imaging unit, and the camera is opened at a position where the lens can image the molten pool. The welding device according to any one of claims 1 to 3, characterized by having an imaging port. An insulating cylinder is provided between the lens and the camera imaging port in the monitoring imaging unit and has an internal space that enables imaging of the molten pool by the lens. Item 5. The welding device according to item 4. 6. The welding device according to claim 4, wherein a heat-resistant glass is arranged so as to cover the camera imaging aperture. The welding torch according to any one of claims 1 to 6, characterized in that the welding torch is inserted through a cylindrical insulating adapter through a torch fixing portion of the after shield jig. Welding equipment. The welding device according to any one of claims 1 to 7, wherein the shield gas nozzle has a diffusion nozzle at its tip for diffusing and jetting the shield gas. Further, the after shield jig includes at least a heat shield plate arranged to shield between the monitoring imaging unit and the molten pool. The welding device according to item 1. The monitoring imaging unit is composed of a camera body having the lens, and a cylindrical lens cover disposed on the incident surface side of the lens and having an internal space capable of imaging the molten pool with the lens. The welding device according to any one of claims 1 to 9, wherein the camera body and the lens cover are detachable. 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.

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