JP7510900B2 - Welding equipment and welding method - Google Patents

Description

The present invention relates to a welding device for welding workpieces and a welding method using the welding device.

Submerged arc welding has traditionally been used to weld steel plates in large structures such as shipbuilding, steel frames, pipe manufacturing, bridges, and vehicles (Patent Document 1). In submerged arc welding, a backing member with flux sprayed on its upper surface is supported by placing it against the underside of the plate joint groove between the steel plates to be welded, and filler material (e.g., cut wire and flux) is sprayed into the groove as necessary, and arc welding is performed from one side using multiple electrodes.

Submerged arc welding is suitable for welding relatively thick steel plates, for example 10 mm to 40 mm, with a large heat input, and can achieve highly efficient welding. However, when submerged arc welding is applied to welding relatively thin steel plates, for example 6 mm to 9 mm, poor welding appearance such as excessively large beads and distortion (bending) of the steel plate due to welding heat can occur, and the amount of thermal deformation of the steel plate after welding increases, which can reduce the dimensional accuracy of the structure and reduce the lifespan of the structure.

Therefore, Patent Document 2 proposes applying gas-shielded arc welding to the welding of thin steel plates, and selectively performing submerged arc welding of thick steel plates and gas-shielded arc welding of thin steel plates. In other words, the welding device disclosed in Patent Document 2 is equipped with a submerged arc welding torch and a gas-shielded arc welding torch.

Patent Document 3 also discloses that plasma welding is applied to the welding of thin steel plates, and that plasma keyhole welding is used when applying plasma welding to butt welding in particular. Plasma welding is a welding method in which an electrode is provided in a plasma welding torch, a plasma arc is generated in a plasma gas state obtained by heating a mixed gas of argon and hydrogen, and the plasma arc is passed through a hole at the tip of the nozzle to narrow the plasma arc and increase the concentration of the heat source. In plasma keyhole welding, the steel plates are joined together by passing the plasma arc between the butted steel plates. Since the heat source is more concentrated in plasma keyhole welding than in gas-shielded arc welding, steel plate distortion caused by welding heat can be further suppressed.

JP 2007-222909 A JP 2006-297459 A JP 2019-51542 A

As mentioned above, it is preferable to apply plasma welding to welding thin steel plates. However, conventionally, submerged arc welding of thick steel plates and plasma welding of thin steel plates have been performed using separate welding equipment, which has resulted in poor efficiency and high equipment costs. Therefore, there is room for improvement in both thick and thin steel plate welding.

The present invention was made in consideration of the above circumstances, and aims to realize thick steel plate welding and thin steel plate welding efficiently and inexpensively.

The present invention, which solves the above-mentioned problems, is characterized in that it provides a welding apparatus for welding workpieces, comprising: a welding carriage that travels along a weld line of the workpieces; a submerged arc welding torch that is mounted on the welding carriage and performs submerged arc welding along the weld line; a non-consumable electrode welding torch that is mounted on the welding carriage and performs non-consumable electrode arc welding along the weld line; a backing support device that raises a backing material onto which flux has been sprayed and presses the backing material against a back surface of a weld portion of the workpieces when performing the submerged arc welding; and a back shield gas supply device that supplies an inert gas to the back surface of the weld portion of the workpieces with the backing material lowered by the backing support device when performing the non-consumable electrode arc welding.

In the welding device, the non-consumable electrode welding torch may be a welding torch that performs plasma welding. Also, the non-consumable electrode welding torch may be a welding torch that performs TIG welding.

In the welding device, the non-consumable electrode welding torch may be provided on another welding carriage that travels along the weld line on the surface of the workpiece. The non-consumable electrode welding torch may also be provided on the welding carriage.

According to another aspect, the present invention provides a welding method for welding workpieces using a welding apparatus, the welding apparatus comprising: a welding carriage that travels along a weld line of the workpieces; a submerged arc welding torch that is mounted on the welding carriage and that performs submerged arc welding along the weld line; and a non-consumable electrode welding torch that performs non-consumable electrode arc welding along the weld line, the welding workpieces being welded by performing at least the submerged arc welding or the non-consumable electrode arc welding, the backing material having flux sprayed thereon is raised by a backing support device when performing the submerged arc welding and the backing material is pressed against a back surface of a weld portion of the workpieces, and the backing material is lowered by the backing support device when performing the non-consumable electrode arc welding, and an inert gas is supplied to the back surface of the weld portion of the workpieces from a back shield gas supply device .

In the welding method , the submerged arc welding may be performed by moving the submerged arc welding torch along the weld line, and then the non-consumable electrode arc welding may be performed using the non-consumable electrode welding torch, and the workpiece may be dressed.

In the welding method, the non-consumable electrode arc welding may be plasma welding. Also, the non-consumable electrode arc welding may be TIG welding.

According to the present invention, a single welding device can be used to selectively perform submerged arc welding of thick steel plates using a submerged arc welding torch, and non-consumable electrode arc welding of thin steel plates using non-consumable electrode arc welding. This allows thick steel plate welding and thin steel plate welding to be performed efficiently, and also allows welding to be achieved economically at low cost. Moreover, since appropriate welding can be performed according to the plate thickness, steel plate distortion due to welding heat can be suppressed, welding defects can be efficiently suppressed, and a welded portion with high fatigue strength can be produced.

1 is a side view showing an outline of a configuration of a welding device according to an embodiment of the present invention. 2 is a side view showing an outline of the configuration of a first welding carriage and a welding head base according to the present embodiment. FIG. FIG. 2 is a side view showing an outline of the configuration of a first welding carriage according to the present embodiment. 2 is a side view showing an outline of the configuration of the welding head base according to the present embodiment. FIG. FIG. 2 is a side view showing an outline of the configuration of the first backing device according to the present embodiment. FIG. 2 is an explanatory diagram showing a state in which steel plates are submerged arc welded in the present embodiment. FIG. 2 is a side view showing an outline of the configuration of a second welding carriage according to the present embodiment. FIG. 2 is a side view showing an outline of the configuration of a second welding carriage according to the present embodiment. FIG. 11 is a side view showing an outline of the configuration of a welding head base according to another embodiment. FIG. 11 is a side view showing an outline of the configuration of a welding head base according to another embodiment.

One embodiment of the present invention will be described below with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals to avoid redundant description.

<Configuration of welding device 1>
First, the configuration of the welding device (welding equipment) according to this embodiment will be described. Fig. 1 is a side view showing an outline of the configuration of the welding device 1 according to this embodiment. In the following, in order to clarify the positional relationship, the X-axis direction, the Y-axis direction, and the Z-axis direction which are mutually perpendicular are defined, the X-axis direction and the Y-axis direction are defined as the horizontal direction, and the positive direction of the Z-axis is defined as the vertical upward direction.

As shown in FIG. 1, the welding device 1 welds a large plate formed by connecting multiple steel plates by tack welding, i.e., a steel plate H (the workpiece in the present invention). Specifically, the welding device 1 selectively performs submerged arc welding and plasma welding on the steel plate H along the same weld line, i.e., along the same straight line or the same curve, or performs submerged arc welding and plasma welding consecutively. In this embodiment, the submerged arc welding is performed as one-sided submerged arc welding using multiple electrodes. In addition, the plasma welding is performed as plasma keyhole welding.

In the welding device 1, the steel plate H is transported in the X-axis direction at the height shown in FIG. 1 by transport rollers (not shown). A pair of rails 2, 2 extending in the X-axis direction are laid on the floor (pit bottom) on which the welding device 1 is installed. A gate-type cart 3 is attached to the rails 2, and the gate-type cart 3 can travel on the rails 2 in the X-axis direction. The gate-type cart 3 may be fixed.

A first welding carriage 10 (welding carriage in the present invention) that travels in the Y-axis direction (the direction in which the weld line of the steel plate H extends) is provided on the beam 3a extending in the Y-axis direction of the gate-shaped carriage 3. A welding head base 11 is supported on the first welding carriage 10. The welding head base 11 is equipped with a submerged arc welding device. The welding head base 11 moves in the Y-axis direction together with the first welding carriage 10 to perform submerged arc welding of the plate joint weld between two steel plates H, H that are connected by tack welding and distributed in the X-axis direction of the steel plate H. The detailed configuration of the first welding carriage 10 and the welding head base 11 will be described later.

On the floor surface on which the welding device 1 is installed, a plurality of rails 4 are laid inside a pair of rails 2, 2, extending in the X-axis direction over several tens of meters in the Y-axis direction. A first backing cart 12 is attached to the rails 4, and the first backing cart 12 can travel on the rails 4 in the X-axis direction. The first backing cart 12 is used when performing submerged arc welding, and is provided with a backing support device 14 that supports a backing copper plate 13 (backing material in the present invention) extending in the Y-axis direction. A plurality of backing support devices 14 are arranged in the Y-axis direction on the first backing cart 12. The detailed configuration of the first backing cart 12 will be described later.

Below the steel plate H and above the first backing cart 12, a flux spraying/recovery cart 15 is provided to spray flux onto the backing copper plate 13 when performing submerged arc welding, and to collect and remove the flux remaining on the backing copper plate 13 after performing submerged arc welding. The flux spraying/recovery cart 15 can travel in the Y-axis direction above the backing copper plate 13.

A second welding carriage 20 (another welding carriage in the present invention) traveling in the Y-axis direction is provided on the upper surface of the steel plate H. The second welding carriage 20 is equipped with a plasma welding device. The second welding carriage 20 moves in the positive direction of the Y-axis, extends in the X-axis direction of the steel plate H, and plasma welds the plate joint weld between the two steel plates H, H that are connected by tack welding. The detailed configuration of the second welding carriage 20 will be described later.

A second backing cart 21 is provided below the steel plate H and above the first backing cart 12, i.e., at the same height as the flux spraying/recovery cart 15. The second backing cart 21 is equipped with a back shield gas supply device for plasma welding.

As described above, the welding device 1 can perform submerged arc welding of the steel plate H using the first welding carriage 10, the welding head base 11, the first backing carriage 12, and the flux spraying/recovery carriage 15. The welding device 1 can also perform plasma welding of the steel plate H using the second welding carriage 20 and the second backing carriage 21.

<Configuration of first welding carriage 10 and welding head base 11>
Next, the configuration of the above-mentioned first welding carriage 10 and the welding head base 11 will be described. Fig. 2 is a side view showing an outline of the configuration of the first welding carriage 10 and the welding head base 11. Fig. 3 is a side view showing an outline of the configuration of the first welding carriage 10. Fig. 4 is a side view showing an outline of the configuration of the welding head base 11.

As shown in Figures 2 and 3, a vertical frame 30 is provided below the first welding carriage 10, extending vertically downward. A lifting frame 31 is supported on the vertical frame 30 so as to be freely raised and lowered in the Z-axis direction, and the lifting frame 31 is moved up and down in the Z-axis direction by a lifting drive mechanism 32 including a lifting drive motor. A welding head base 11 is suspended and supported on the lifting frame 31 so as to be freely movable in the X-axis direction, and the welding head base 11 is moved in the X-axis direction, i.e., in the direction across the groove at the welding portion of the steel plate H (in the width direction of the groove), by a horizontal drive mechanism 33 provided on the lifting frame 31 and including a horizontal drive motor.

The first welding carriage 10 is provided with a flux hopper 40 for supplying flux to the flux spray nozzles 60, 63 (described later) on the welding head base 11. The first welding carriage 10 is also provided with three wire coils 41 for supplying welding wire to the submerged arc welding torches 61, 62, 64 (described later) on the welding head base 11.

As shown in FIG. 4, a hanging leg 50 is provided at the bottom of the welding head base 11. A groove position sensor 51 that detects the positional deviation of the groove in the X-axis direction (width direction) and Z-axis direction (depth direction) is supported at one end of the hanging leg 50. A tracing roller 52 of the groove detector and a manual adjustment mechanism 53 that supports the tracing roller 52 and adjusts (sets) the position in the X-axis direction and Z-axis direction so that the tracing roller 52 is the center of the width of the groove are supported at the other end of the hanging leg 50. When performing submerged arc welding, a control device (not shown) drives the lifting drive motor of the lifting drive mechanism 32 and the horizontal drive motor of the horizontal drive mechanism 33 based on the position deviation signal in the X-axis direction and Z-axis direction of the groove from the groove position sensor 51 or the tracing roller 52 of the groove detector so that the welding head base 11 is at a predetermined height position and X-axis position set in advance with respect to the groove.

A cut wire spray nozzle (not shown) of the cut wire spray device is provided behind the tracing roller 52 in the direction of movement of the welding head base 11 during welding (Y-axis direction). The cut wire spray nozzle is supplied with cut wire stored in a cut wire hopper (not shown) provided on the welding head base 11.

A first flux spray nozzle 60 is provided behind the cut wire spray nozzle in the direction of movement (Y-axis direction) of the welding head base 11 during welding, and a first submerged arc welding torch 61 is provided further behind it. The first flux spray nozzle 60 is supported by the base of the first submerged arc welding torch 61. The base of the first submerged arc welding torch 61 is supported by the welding head base 11. Flux is supplied to the first flux spray nozzle 60 from the flux hopper 40 on the first welding carriage 10 shown in Figures 2 and 3. Welding wire is supplied to the first submerged arc welding torch 61 from one of the three wire coils 41 on the first welding carriage 10 shown in Figures 2 and 3.

A second submerged arc welding torch 62 is provided behind the first submerged arc welding torch 61 in the direction of movement of the welding head base 11 during welding (Y-axis direction). The core of the second submerged arc welding torch 62 is supported by the welding head base 11. The second submerged arc welding torch 62 is supplied with welding wire from one of the three wire coils 41 on the first welding carriage 10 shown in Figures 2 and 3.

A second flux spray nozzle 63 is provided behind the second submerged arc welding torch 62 in the direction of movement of the welding head base 11 during welding (Y-axis direction), and a third submerged arc welding torch 64 is provided further behind it. The second flux spray nozzle 63 is supported by the base of the third submerged arc welding torch 64. The base of the third submerged arc welding torch 64 is supported by the welding head base 11. Flux is supplied to the second flux spray nozzle 63 from the flux hopper 40 on the first welding carriage 10 shown in Figures 2 and 3. Welding wire is supplied to the third submerged arc welding torch 64 from one of the three wire coils 41 on the first welding carriage 10 shown in Figures 2 and 3.

In this embodiment, the welding head base 11 is provided with three submerged arc welding torches 61, 62, and 64, but the number of submerged arc welding torches is not limited to this.

A flux collector (suction nozzle) 65 is provided behind the third submerged arc welding torch 64 in the direction of movement of the welding head base 11 during welding (Y-axis direction). The core of the flux collector 65 is supported by the welding head base 11. The flux collector 65 sucks up the flux remaining around the groove after welding and returns it to the flux hopper 40 shown in Figures 2 and 3.

<Configuration of the first backing cart 12>
Next, a description will be given of the configuration of the above-mentioned first backing cart 12. Fig. 5 is a side view showing an outline of the configuration of the first backing device including the first backing cart 12.

As shown in FIG. 5, a pair of vertical blocks 70, 71 are provided on the first backing cart 12, one on the positive side of the X-axis and the other on the negative side of the X-axis. Rollers 72, 73 for transporting the steel plate H are provided on the upper surfaces of the vertical blocks 70, 71, respectively. In addition, a magnet 74 for restraining the steel plate and a fixed support roller 75 for adjusting the height of the plate joint of the steel plate H are provided on the upper surfaces of the vertical blocks 70, 71, respectively. The plate joint of the steel plate H is located directly above the backing copper plate 13, and the steel plate H on the X-axis direction side of the plate joint is supported by the fixed support roller 75.

The first backing cart 12 is provided with a plurality of backing support devices 14 that support the backing copper plate 13 extending in the Y-axis direction as described above. The backing copper plate 13 and the backing support devices 14 are provided between the vertical blocks 70 and 71.

The backing support device 14 is equipped with a backing copper plate cart 80 that supports the backing copper plate 13. The backing copper plate cart 80 is supported by a lifting frame 90 and is configured to be freely movable in the X-axis direction. The backing copper plate cart 80 is provided with a copper plate support table 81 that supports the backing copper plate 13, and an air hose 82 that raises and lowers the copper plate support table 81 in the Z-axis direction. The air hose 82 is, for example, a repurposed firefighting water supply hose. Compressed air is supplied to the air hose 82, causing it to expand into an oval shape, thereby raising the copper plate support table 81.

The lifting frame 90 is configured to be able to move up and down freely in the Z-axis direction between the vertical blocks 70, 71. The lifting frame 90 has an arm 91 that protrudes in the positive direction of the X-axis and an arm 92 that protrudes in the negative direction of the X-axis. The arms 91, 92 are supported by lifting units 93, 94, respectively. These lifting units 93, 94 raise the lifting frame 90 (backing copper plate 13). The lifting units 93, 94 are each supported by the first backing cart 12.

Below the space in which the lifting frame 90 rises and falls, a chain conveyor 100 is supported by a first backing cart 12. The endless chains 101, 102 of the chain conveyor 100 are meshed with and stretched over a sprocket wheel 103 shown in FIG. 1, and have multiple scraping legs protruding on both sides (X-axis direction) of the chain for transporting powder such as flux and slag. The scraping legs of the upper endless chain 101 are in sliding contact with a groove plate 104 extending in the Y-axis direction. The flux and slag on the groove plate 104 are transported in the Y-axis direction and fall onto a belt conveyor 105 extending in the X-axis direction shown in FIG. 1, and are carried out in the X-axis direction by the belt conveyor 105.

<Submerged arc welding method>
Next, a description will be given of a method for submerged arc welding the steel plate H. Fig. 6 is an explanatory diagram showing a state in which the steel plate H is submerged arc welded.

First, as shown in FIG. 6(a), the flux spraying/recovery cart 15 travels in the Y-axis direction over the backing copper plate 13, and the flux spraying/recovery cart 15 sprays backing flux Fr onto the backing copper plate 13. The thickness of the backing flux Fr is, for example, about 6 mm. At this time, the backing copper plate 13 is lowered as shown by the solid line in FIG. 5 and placed in the retreated position.

Next, the backing copper plate 13 is raised as shown by the two-dot chain line in Figure 5 and placed at the welding position. For example, the welding position is a position where the upper surface of the backing copper plate 13 is about 20 mm below the lower surface of the steel plate H. Next, compressed air is supplied to the air hose 82 as shown in Figure 6 (b), and the air hose 82 expands to an oval shape, raising the copper plate support table 81 and driving the backing copper plate 13 upward. Then, the backing flux Fr sprayed on the backing copper plate 13 is pressed against the lower surface of the steel plate H.

In this state, the submerged arc welding device of the welding head base 11 travels in the Y-axis direction while welding the plate joint along the weld line of the steel plate H. During welding, the cut wire Cw is fed from the cut wire spray nozzle to the groove (weld portion) of the steel plate H, and further, surface flux Ff is sprayed onto the cut wire Cw, for example, from the first flux spray nozzle 60. Then, the cut wire Cw is melted by the arc of the welding wire Ew from, for example, the first submerged arc welding torch 61. In this way, the steel plate H is welded.

When welding of the entire length of the steel plate H in the Y-axis direction is completed, the backing copper plate 13 is lowered as shown by the solid line in Figure 5 and placed in a retreated position. At this time, the backing flux Fr and slag remaining on the backing copper plate 13 are removed by the flux spreading and recovery cart 15, transported by the chain conveyor 100, and dropped onto the belt conveyor 105, which then carries them out in the X-axis direction.

<Configuration of second welding carriage 20>
Next, a description will be given of the configuration of the above-mentioned second welding carriage 20. Fig. 7 and Fig. 8 are side views each showing an outline of the configuration of the second welding carriage 20.

As shown in Figures 7 and 8, the second welding carriage 20 is provided with a lifting drive mechanism 110 including a lifting drive motor. An arm 111 is supported on the lifting drive mechanism 110, and the arm 111 moves up and down in the Z-axis direction by the lifting drive mechanism 110. The lifting drive mechanism 110 is also provided on a horizontal movement mechanism (not shown), and the lifting drive mechanism 110 and the arm 111 move in the X-axis direction by the horizontal movement mechanism.

A plasma welding torch 120 (non-consumable electrode welding torch in the present invention), a wire head 121, and a camera protection tube 123 are provided on the arm 111 via a support member 112. A welding wire is supplied from the wire head 121 through a wire extrusion pipe 122 to the lower part of the plasma welding torch 120. Note that, although one plasma welding torch 120 is provided on the second welding carriage 20 in this embodiment, the number of plasma welding torches is not limited to this, and multiple plasma welding torches may be provided.

Inside the camera protection tube 123, a camera 124 with an imaging element is provided to capture an image of the weld line immediately before welding the steel plate H. When performing plasma welding, a control device (not shown) calculates the X-axis position of the weld line and the groove width of the weld line based on the image signal of the weld line from the camera 124 with the imaging element. Based on the calculated X-axis position of the weld line, the control device drives the horizontal drive motor of the horizontal drive mechanism to which the lift drive mechanism 110 is attached so that the X-axis position of the weld line becomes a predetermined reference position. Based on the calculated groove width of the weld line, the control device also sets welding conditions (e.g., welding current value, wire feed speed, pilot gas feed amount, welding carriage speed, etc.) suitable for welding the groove.

<Configuration of the second backing cart 21>
A known backing cart may be combined for use as the second backing cart 21. For example, the backing cart described in JP 2017-77575 A and the backing support device described in JP 2006-297459 A may be combined to configure the second backing cart 21 equipped with a back shield gas supply device.

<Plasma welding method>
Next, a method for plasma welding the steel plate H, specifically, plasma keyhole welding, will be described.

Before plasma welding, the backing copper plate 13 of the first backing carriage 12 is lowered as shown by the solid line in Figure 5 and placed in a retracted position.

In this state, the second welding carriage 20 travels in the Y-axis direction while welding the plate joint along the weld line of the steel plate H. Specifically, a plasma arc from the plasma welding torch 120 is applied to the groove of the steel plate H. This forms a keyhole penetrating the steel plate H. As the welding progresses, this keyhole moves rearward, and the molten metal also moves rearward and solidifies, forming a continuous weld bead. In this way, the plate joint of the steel plate H is welded.

When a plasma arc is applied to the groove of the steel sheet H, the back shield gas supplied from the back shield gas supply device of the second backing cart 21 is blown out from the gas blowing hole into the gas suction space, gas shielding the underside of the steel sheet H in an argon gas atmosphere. This makes it possible to suppress oxidation of the back bead and to prevent bead shape defects.

<Operation of Welding Device 1>
Next, the operation of the welding device 1 configured as above will be described. In this embodiment, the following three operation patterns will be described. In the three operation patterns, submerged arc welding and plasma welding are each performed in the manner described above.

[First Operation Pattern]
The first operation pattern is a pattern in which either submerged arc welding or plasma welding (plasma keyhole welding) is performed. For example, when welding a thick steel plate H having a thickness of 10 mm to 40 mm, submerged arc welding is performed. On the other hand, when welding a thin steel plate H having a thickness of 6 mm to 9 mm, plasma welding is performed.

In this way, submerged arc welding and plasma welding can be selectively performed using a single welding device 1. This allows both thick and thin steel plate welding to be performed efficiently, and also allows for economical welding to be achieved at low cost. Furthermore, since appropriate welding can be performed according to the plate thickness, steel plate distortion caused by welding heat can be suppressed, welding defects can be efficiently suppressed, and a welded portion with high fatigue strength can be produced.

[Second Operation Pattern]
The second operation pattern is a pattern in which submerged arc welding is performed after plasma welding. For example, after plasma welding the first layer in the groove of the steel plate H, submerged arc welding is performed from above the first layer. In such a case, by performing plasma welding, heat input at the beginning of welding can be suppressed, and the degree of freedom of welding is increased. By performing submerged arc welding after that, welding can be performed efficiently. In addition, by plasma welding the first layer of the groove, it is also possible to suppress poor penetration of the back bead, which is likely to occur in submerged arc welding. Furthermore, by plasma welding the first layer of the groove, it is easy to control the weld width, and it is also possible to weld with the same width along the weld line.

[Third Operation Pattern]
The third operation pattern is a pattern in which submerged arc welding is performed and then plasma welding is performed. For example, when submerged arc welding is performed, a weld bead is formed, and plasma welding is performed on the weld toes at both ends of the weld bead to remelt and dress the weld toes. This plasma welding dressing increases the curvature of the weld toes, making it possible to suppress stress concentration at the weld toes and thus produce welded portions with high fatigue strength. Moreover, welding and dressing can be performed continuously using a single welding device 1, which is efficient.

<Other embodiments of the welding device 1>
In the above embodiment, the second welding carriage 20 is provided with the plasma welding torch 120, but a TIG welding torch for performing TIG welding may be provided instead of the plasma welding torch 120. In such a case, a backing carriage having the same configuration as the above-mentioned second backing carriage 21 is used.

Even when TIG welding is performed instead of plasma welding in this way, the same effects as in the above embodiment can be obtained. In particular, in recent years, TIG welding using a large current is sometimes performed, and in such cases, the same effects as plasma welding can be obtained with TIG welding. In other words, to obtain the above effects, the welding device 1 can perform non-consumable electrode arc welding such as plasma welding and TIG welding in addition to submerged arc welding.

<Other embodiments of the welding device 1>
In the welding device 1 of the above embodiment, the plasma welding torch 120 is provided on the second welding carriage 20, but as shown in FIG. 9, a plasma welding torch 130 may be provided on the welding head base 11.

The plasma welding torch 130 is provided behind the groove position sensor 51 in the direction of movement of the welding head base 11 during welding (Y-axis direction), and behind a cut wire spray nozzle (not shown) of the cut wire spray device. The plasma welding torch 130 is detachably attached to a holder 131. The holder 131 is supported by the lower end of a hanging leg 132, and the upper end of the hanging leg 132 is supported by the welding head base 11. In this embodiment, the second welding carriage 20 can be omitted.

For example, when performing submerged arc welding, the plasma welding torch 130 may be removed from the holder 131, and when performing plasma welding, the plasma welding torch 130 may be attached to the holder 131. Even in such a case, the first to third operation patterns described above can be performed using the welding device 1. Moreover, since the second welding carriage 20 can be omitted, the device configuration can be further simplified.

The position of the plasma welding torch 130 is not limited to the example shown in FIG. 9. For example, as shown in FIG. 10, the plasma welding torch 130 may be provided behind the flux collector 65.

In addition, in this embodiment, the welding head base 11 may be provided with a TIG welding torch instead of the plasma welding torch 130.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

The present invention can be used in a welding device and a welding method for welding workpieces.

1 Welding device 2 Rail 3 Gate-type cart 3a Beam (of gate-type cart 3) 4 Rail 10 First welding cart 11 Welding head base 12 First backing cart 13 Backing copper plate 14 Backing support device 15 Flux spraying/recovery cart 20 Second welding cart 21 Second backing cart 30 Vertical frame 31 Lifting frame 32 Lifting drive mechanism 33 Horizontal drive mechanism 40 Flux hopper 41 Wire coil 50 Suspension leg 51 Groove position sensor 52 Copying roller 53 Manual adjustment mechanism 60 First flux spray nozzle 61 First submerged arc welding torch 62 Second submerged arc welding torch 63 Second flux spray nozzle 64 Third submerged arc welding torch 65 Flux recovery device 70, 71 Vertical block 72, 73 Transport roller 74 Steel plate restraining magnet 75 Support fixed roller 80 Backing copper plate cart 81 Copper plate support stand 82 Air hose 90 Lifting frame 91, 92 Arm 93, 94 Lifting unit 100 Chain conveyor 101, 102 Endless chain 103 Sprocket wheel 104 Groove plate 105 Belt conveyor 110 Lifting drive mechanism 111 Arm 112 Support member 120 Plasma welding torch 121 Wire head 122 Wire extrusion pipe 123 Camera protection tube 124 Camera with imaging element 130 Plasma welding torch 131 Holder 132 Suspension leg Cw Cut wire Ew Welding wire Ff Front flux Fr Back flux H Steel plate

Claims (9)

In a welding device for welding workpieces,
A welding carriage that travels along a weld line of the workpiece;
a submerged arc welding torch provided on the welding carriage and performing submerged arc welding along the weld line;
a non-consumable electrode welding torch for performing non-consumable electrode arc welding along the weld line ;
a backing support device that, when performing the submerged arc welding, raises a backing material to which flux has been sprayed and presses the backing material against a back surface of a welding portion of the workpiece;
a back shield gas supply device that supplies an inert gas to a back surface of a welding portion of the workpiece while the backing material is lowered by the backing support device when performing the non-consumable electrode arc welding . The welding device of claim 1, wherein the non-consumable electrode welding torch is a welding torch that performs plasma welding. The welding device according to claim 1, wherein the non-consumable electrode welding torch is a welding torch for TIG welding. The welding device according to any one of claims 1 to 3, wherein the non-consumable electrode welding torch is provided on another welding carriage that travels along the weld line on the surface of the workpiece. The welding device according to any one of claims 1 to 3, wherein the non-consumable electrode welding torch is provided on the welding carriage. A welding method for welding workpieces using a welding device, comprising the steps of:
The welding device includes:
A welding carriage that travels along a weld line of the workpiece;
a submerged arc welding torch provided on the welding carriage and performing submerged arc welding along the weld line;
a non-consumable electrode welding torch for performing non-consumable electrode arc welding along the weld line,
Welding the workpiece by performing at least the submerged arc welding or the non-consumable electrode arc welding;
When performing the submerged arc welding, a backing material on which flux has been sprayed is raised by a backing support device, and the backing material is pressed against the back surface of the welded portion of the workpiece;
a back shield gas supply device for supplying an inert gas to a back surface of a welded portion of the workpieces while the backing material is lowered by the backing support device when performing the non-consumable electrode arc welding . The submerged arc welding torch is moved along the weld line to perform the submerged arc welding;
7. The welding method according to claim 6 , further comprising the steps of: performing the non-consumable electrode arc welding using the non-consumable electrode welding torch; and dressing the workpiece. The welding method according to claim 6 or 7 , wherein the non-consumable electrode arc welding is plasma welding. The welding method according to claim 6 or 7 , wherein the non-consumable electrode arc welding is TIG welding.

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