JP2003053541A - Wire feeder, welding equipment and welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire feeder which hardly gives rise to feeding unevenness and can maintain good wire feedability, a welding equipment which hardly gives rise to a welding defect in consumable electrode process arc welding and a welding method. SOLUTION: A rotary cylinder 40 is rotatably (loosely rotatably) fitted from an outer side to a stationary shaft 20 attached like a cantilever to a reel strut 10. The rotary cylinder 40 is attachably and detachably inserted from an inner side to a wire reel 50 wound with a wire 301 and attached to the stationary shaft 20 rotatably integrally together with the rotary cylinder 40. A spring back member 60 adds thrust force S, i.e., the pressing force in a thrust direction from a free end side toward a supporting end side to the rotary cylinder 40 and a bearing member 70 in contact with the rotary cylinder 40 is arranged in order to accept the thrust force S added by this spring back member 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire feeding device, a welding device and a welding method using the same.

[0002]

2. Description of the Related Art In a wire feeding device using a wire reel, if the feeding resistance of the wire pulled out from the wire reel increases or fluctuates (feeding unevenness = deterioration of feeding ability), May have a serious impact on For example, in a welding wire feeder for arc welding as shown in FIG. 5, when the feedability of the wire is deteriorated, the arc becomes unstable due to variations in the arc length and the like, which causes welding defects and the like. There is a risk.

FIG. 5A shows a TIG welding (tungsteninert gas arc wel) which is a kind of non-consumable electrode type arc welding method.
ing), and an inert gas IG such as argon or helium.
An arc AR is generated between the tungsten electrode 101 and the base material WP in the atmosphere, and the filler material (welding wire) drawn from the wire reel 500 by the feeding roller 102 driven by a motor or the like (not shown). 104 is fed into the arc AR through the wire guide 103 and welded. 10
5 is a gas nozzle (torch) for ejecting the inert gas IG from the tip opening, 106 is a support member fixed to the torch 105 and holding the tungsten electrode 101, WM is weld metal, and MP is a molten pool. When the feedability of the welding wire 104 deteriorates in TIG welding, the welded portion (weld metal W
Formation of M) may become unstable, resulting in insufficient strength (welding failure).

FIG. 5B shows a consumable electrode type arc welding method 1
MIG welding (metallic inert gas arc wel)
ing), and an inert gas IG such as argon or helium.
Electrode wire (welding wire) 201 and base material WP in atmosphere
An arc AR is generated between the electrode wire 201 and the electrode wire 201, and as the electrode wire 201 melts, the electrode wire 201 pulled out from the wire reel 500 by the feeding roller 202 driven by a motor or the like (not shown) is fed into the arc AR. Supply and weld. 205 is a gas nozzle (torch) that has a flexible conduit tube 204 on the proximal end side and ejects an inert gas from the tip, and 206 is fixed to the torch 205 to hold the electrode wire 201 and supply current to the electrode wire 201. Electrode tip (contact tip), WM is weld metal, and MP is molten pool. When the feedability of the electrode wire 201 deteriorates in MIG welding, the arc AR becomes unstable because it directly affects the variation of the arc length, which may cause welding failure.

[0005]

As described above, in the welding wire feeding apparatus in arc welding, it is important to keep the feeding ability of the wire good and prevent welding defects. By the way, as shown in FIG. 6, the wire reel 500 is rotatably (idle) fitted from the outside to a fixed shaft 520 that is cantilevered on a reel column 510. Specifically, the outer peripheral surface of the shaft portion 521 of the fixed shaft 520 is covered with the inner peripheral surface of the shaft cylindrical portion 501 of the wire reel 500, and the free end side end surface of the fixed flange 522 formed at the support end of the fixed shaft 520. Out of the reel flanges 502 formed at both shaft ends of the wire reel 500, the outer end surfaces of the ones corresponding to the fixed flanges 522 are held in contact with each other. The welding wires 104 and 201 wound around the wire reel 500 are the above-mentioned feeding rollers 102 and 202.
And is fed into the arc AR (FIG. 5).
(See (a) and (b)). 530 is a U-shaped stopper that is fixed by being fitted into an annular groove 523 formed on the outer circumference of the free end of the fixed shaft 520 and that prevents the wire reel 500 from coming off.

According to the knowledge of the present inventors, in the fixed shaft 520 and the wire reel 500 which are fitted so as to be rotatable relative to each other, the irregularities (surface roughness) of the outer peripheral surface of the shaft portion 521 of the fixed shaft 520 are relatively small. On the other hand, in the wire reel 500, which is a mass-produced product, the irregularities (surface roughness) on the inner peripheral surface of the shaft tube portion 501 tend to be relatively large (see the enlarged view in FIG. 6). Therefore, the wire reel 500 (and the welding wires 104 and 201 wound around it) easily swings (vibrates) on the fixed shaft 520 in the radial direction (or the direction intersecting with the fixed shaft 520). In addition, the welding wires 104 and 201 pulled out by the feeding rollers 102 and 202 are likely to sag due to fluctuations in the pulling force and the like. It is considered that these runouts and slacks cause the uneven feed as described at the beginning, which contributes to defective welding.

[0007] Such uneven feeding is caused by arc length in consumable electrode type arc welding (for example, MIG welding) in which electrodes melt during welding, as compared with non-consumable electrode type arc welding in which electrodes do not melt during welding (for example, TIG welding). Fluctuations are likely to occur and welding defects are likely to occur.

An object of the present invention is to provide a wire feeding device which is less likely to cause uneven feeding and can maintain a good wire feeding property, a welding device and a welding method which are less likely to cause welding defects in consumable electrode type arc welding. To provide.

[0009]

Means for Solving the Problems and Effects of the Invention In order to solve the above-mentioned problems, a wire feeding device of the present invention is a cantilevered fixed shaft attached to a supporting member, and its fixing. A tubular member that is rotatably fitted to the shaft from the outside, a wire is wound around the tubular member, the tubular member is detachably inserted, and a wire reel that is integrally rotatable with the tubular member; Thrust force applying means for applying a thrust force (hereinafter referred to as thrust force) in the thrust direction from the free end side of the fixed shaft to the support end side of the fixed shaft, and the thrust force adding means added by the thrust force adding means. Thrust force receiving means for contacting the tubular member to receive the thrust force, wherein the thrust force applying means applies the thrust force to the tubular member, As the wire is pulled out from the ear reel, the tubular member rotates around the fixed shaft together with the wire reel while generating a frictional force with at least the thrust force receiving means. It is characterized by

According to the present invention, when the wire is pulled out from the wire reel, the tubular member integrally generates around the fixed shaft together with the wire reel while generating a frictional force between the tubular member and the thrust force receiving means. Since the wire rotates, the wire is less likely to swing in the radial direction of the wire reel (or in the direction intersecting the fixed axis). Further, since the thrust force acts on the tubular member as a braking force, the wire reel is less likely to idle due to fluctuations in the pulling force, etc., and slack between the wire reel and the feeding roller is less likely to occur. .

In order to solve the above-mentioned problems, the welding apparatus of the present invention is characterized in that the wire feeding apparatus is used as an electrode wire feeding apparatus in consumable electrode type arc welding.

Further, in order to solve the above-mentioned problems, the welding method of the present invention is characterized in that the wire feeding device is used as a feeding device for an electrode wire to perform consumable electrode type arc welding.

According to these welding devices and welding methods, the electrode wire for consumable electrode type arc welding is less likely to sag due to radial runout when the wire is pulled out from the wire reel, fluctuations in the pulling force, etc. Since unevenness is less likely to occur, instability of the arc and the like due to variations in the arc length and the like are suppressed, and welding defects and the like are less likely to occur.

In the consumable electrode type arc welding, since the weight of the wire reel wound with the electrode wire is relatively smaller (the inertia is smaller), the electrode wire made of a material having a smaller specific gravity has a larger deflection. Therefore, uneven feeding is likely to occur. For example, when joining base materials made of active metals (including pure metals and alloys) such as Ti, Al, Mg, Li or alloys thereof having a smaller specific gravity than mild steel (or Fe) by MIG welding, Since the same kind of active metal wire rod is used as the electrode wire, it can be said that uneven feeding of the electrode wire is likely to occur. Therefore, in the consumable electrode type arc welding (for example, MIG welding), if the welding device and the welding method of the present invention are applied to the electrode wire made of the active metal material having a relatively small specific gravity, the arc length variation is suppressed and welding failure occurs. The effect of making it harder to exert is more effectively exhibited.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a welding apparatus of the present invention, which is an example of a consumable electrode type arc welding apparatus, MIG.
The welding apparatus is shown typically.

The MIG welding apparatus 300 shown in FIG. 1 is an industrial pure titanium which is one of active metals having a specific gravity smaller than that of mild steel (or Fe) as the MIG welding wire 301 (electrode wire; hereinafter also simply referred to as wire). In the case of performing MIG welding of the engine exhaust pipe EP made of pure titanium or titanium alloy, which is one kind of active metal having a specific gravity smaller than that of mild steel (or Fe), as a base material, using a wire rod TW made of Shows. An arc AR is generated between the wire 301 and the exhaust pipe EP (base material) in an IG atmosphere of an inert gas such as argon or helium, and as the wire 301 melts, a motor or the like (not shown)
Wire feeding device 1 driven by feeding roller 302 driven by
The wire 301 drawn from the wire reel 50 is fed into the arc AR and welded.

Numeral 303 is a straightening roller for straightening the habit of the wire 301, 305 is a flexible conduit tube 304 on the base end side, and a torch for ejecting an inert gas from the tip end, 306 is holding the wire 301. In addition, an electrode tip (contact tip) that supplies a current to the wire 301, WM is a weld metal, and MP is a molten pool. In addition, in order to perform shielding with an inert gas until the temperature of the welded portion becomes 400 ° C. or lower (the temperature at which titanium and its alloy become inactive), the after shield jig 307 covering the rear side in the welding direction and the backside of the welded portion. And a back shield jig 308 for covering.

FIG. 2 is a sectional view showing details of the wire feeding device 1 used in the MIG welding device 300, and FIG. 3 is an exploded perspective view of the main part of FIG. Reel support 10
Fixed shaft 20 cantilevered to (support member)
A rotary cylinder 40 (cylindrical member) is rotatably (idle) fitted from the outside. The rotary cylinder 40 is removably inserted from the inside of the wire reel 50 around which the wire 301 is wound, and is attached to the fixed shaft 20 so as to be rotatable integrally with the rotary cylinder 40. The fixed shaft 2
0, the rotary cylinder 40, and the wire reel 50 are configured coaxially, and in the axis (thrust) direction common to them, the side where the fixed shaft 20 is cantilevered to the reel support 10 is the support end side, The opposite side is called the free end side.

Specifically, the outer peripheral surface of the shaft portion 21 of the fixed shaft 20 is covered with the inner peripheral surface of the rotating shaft portion 41 of the rotating cylinder 40, and the outer peripheral surface of the rotating shaft portion 41 is covered with the inner peripheral surface of the shaft cylindrical portion 51 of the wire reel 50. It is constructed in a three-layer structure in which the faces are covered. In addition, the fixed shaft 2
The free end side end surface of the fixed flange 22 formed on the support end side of 0 is abuttingly held on the support end side end surface of the rotary flange 42 also formed on the support end side of the rotary cylinder 40. On the free end side of the wire reel 5
Outer end faces (end faces on the support end side) of the reel flanges 52 corresponding to the rotary flange 42 formed at both shaft ends of 0 are held in contact with each other.

An elastic member 60 (thrust force applying means) applies a thrust force S, that is, a pressing force in the thrust direction from the free end side to the support end side, to the rotary cylinder 40. In order to receive the added thrust force S, a bearing member 70 (thrust force receiving means) that is in contact with the rotary cylinder 40 is arranged.

Specifically, the rotary shaft portion 41 of the rotary cylinder 40
In addition, a concave portion 43 having a larger diameter than the fixed shaft 40 and a predetermined depth (for example, about 1/3 to 1/2 of the axial length of the rotary shaft portion 41) is formed along the thrust direction from the free end side. Formed,
The fixed shaft 20 is inserted into the rotary cylinder 40, and the free end of the shaft portion 21 of the fixed shaft 20 is arranged so as to project into the recess 43.
Further, the shaft portion 21 of the fixed shaft 20 is provided with a screw hole 23 along the thrust direction from the free end side to a predetermined depth (for example, about 1/3 to 1/2 of the axial length of the shaft portion 21). A male screw portion 81 formed on the screw member 80 (thrust force adjusting means) is screwed into the screw hole 23. A ring-shaped bearing member 70 having a step portion 70a in the radial direction is fitted to the outer peripheral surface of the shaft portion 21 of the fixed shaft 20 and the recess 4 is formed.
A flange portion 82 having a step portion 82a in the radial direction is formed on the free end side of the screw member 80 while being in contact with the bottom of the screw member 80. The elastic member 60 such as a compression coil spring is housed and held in the recess 43, and the stepped portion 70a of the bearing member 70 and the stepped portion 82 of the flange portion 82 are held.
It is hung over a.

A pressure handle 90 (thrust force adjusting means) is attached to the screw member 80 so as to project from the flange portion 82 toward the free end side. The pressure handle 90 is formed substantially coaxially with the male screw portion 81 and has one end portion with the collar portion 82.
Connection portion 91 fixed by welding or the like to the male screw portion 8
A grip portion 92 for screwing 1 into the screw hole 23 of the fixed shaft 20, and the grip portion 92 rotates with respect to the other end of the connecting portion 91 in a plane parallel to the axis of the male screw portion 81. It has the fulcrum pin 93 which connects the handle part 92 and the connection part 91 so that it may be possible.

Reference numeral 30 is a U-shaped stopper which is fixed by being fitted into an annular groove 44 formed on the outer periphery of the free end portion of the rotary shaft portion 41 of the rotary cylinder 40 and which prevents the wire reel 50 from coming off.

Since the elastic member 60, which is a thrust force applying means, is housed in the recess 43 formed in the rotary shaft portion 41 of the rotary cylinder 40, the elastic member 6 in the wire feeding device 1 is accommodated.
0 and the flange portion 82 and the like of the screw member 80 that holds the 0 can be made compact and compact. Further, the bearing member 70, which is a thrust force receiving means, is provided in the shaft portion 21 of the fixed shaft 20.
Since it is fitted on the outer peripheral surface and is arranged so as to be in contact with the bottom of the recess 43, it does not hinder the holding of the elastic member 60, and the rotary cylinder 40 in the state of receiving the thrust force S
It enables smooth rotation of.

Next, a method of assembling the wire feeding device 1 will be described. As shown in FIGS. 3 and 2, the reel support 1
The rotary cylinder 40 was fitted from the free end side of the shaft portion 21 of the fixed shaft 20 protruding cantilevered from 0, and the wire 301 was wound from the free end side of the rotary shaft portion 41 of the rotary cylinder 40. The wire reel 50 is fitted. Next, the bearing member 70 is arranged so as to be fitted to the outer peripheral surface of the shaft portion 21 of the fixed shaft 20 and to be in contact with the bottom of the recess 43 of the rotary cylinder 40. After fitting one end of the elastic member 60 into the stepped portion 70a of the bearing member 70, the male screw portion 81 of the screw member 80 (pressure handle 90) is inserted from the opening side of the recess 43 into the elastic member 60. Then, it is screwed into the screw hole 23 of the fixed shaft 20. In this state, rotate the grip portion 92 around the axis of the male screw portion 81,
By screwing the male screw portion 81 into the screw hole 23 of the fixed shaft 20, the other end portion of the elastic member 60 is supported by the step portion 82 a of the collar portion 82. Finally, the stopper 30 is fitted and fixed in the annular groove 44 formed in the rotary shaft portion 41 of the rotary cylinder 40.

As a result, when the thrust force S is applied to the rotary cylinder 40 by the elastic member 60, the feeding roller 302 is driven and rotated to rotate the wire 3 from the wire reel 50.
When 01 is pulled out, the rotary cylinder 40 rotates integrally with the wire reel 50 around the shaft portion 21 of the fixed shaft 20 while generating a frictional force between the bottom of the recess 43 and the bearing member 70. Therefore, the wire 301 or the wire reel 50 is less likely to swing in the radial direction (or in the direction intersecting with the fixed shaft 20). Further, since the thrust force S acts on the rotating cylinder 40 as a braking force, it is difficult for the wire reel 50 to idle due to fluctuations in the drawing force of the feeding roller 302, and the wire reel 50 and the feeding roller 302 Sag is less likely to occur between Therefore, uneven feeding of the wire 301 is less likely to occur, and the stability of the arc is maintained.

Further, for example, when the wire 301 is pulled out from the wire reel 50 and the total weight of the wire reel 50 is reduced so that uneven feeding of the wire 301 is likely to occur, the grip portion 92 of the pressing handle 90 is provided. When the male screw portion 81 is rotated around the axis of the male screw portion 81, the male screw portion 81 can be screwed into the screw hole 23 of the fixed shaft 20 to reduce the elastic member 60. The increase adjustment of S can be easily performed. Even if the wire 301 is made of a different material (composition), the thrust force S
The increase / decrease adjustment can be easily performed.

When the fixed shaft 20 and the rotary cylinder 40 rotate integrally, the bearing member 70 is in principle integrated with the fixed shaft 20 by the thrust force of the elastic member 60, and the rotary cylinder 40 is rotated. Although it is in a state of slipping between itself and the bottom of the concave portion 43, it may rotate together with the bottom of the concave portion 43 and slide at the end of the elastic member 60 at a '.
Further, the thrust force S is also generated between the free end side end surface of the fixed flange 22 formed on the support end side of the fixed shaft 20 and the support end side end surface of the rotary flange 42 formed on the support end side of the rotary cylinder 40. Upon receiving the frictional force, a frictional force is generated, and a slippage occurs between them.

FIG. 4 shows a modification of the rotary cylinder 40 shown in FIG.
Each modification of FIG. 4 prevents slippage (relative rotation) in the circumferential direction between the outer peripheral surface of the rotary shaft portion 41 of the rotary cylinder 40 and the inner peripheral surface of the shaft cylinder portion 51 of the wire reel 50 in FIG. 2. Therefore, the deformable structure that the rotary cylinder 40 can adopt is illustrated. Figure 4
An engaging portion 45 (engaging convex portion or engaging concave portion; engaging convex portion in the drawing) protruding toward the free end side is formed on an end surface of the rotary flange 42a of the rotary cylinder 40a shown in FIG. It is possible to prevent the rotation shaft portion 41 from slipping in the circumferential direction with respect to the inner peripheral surface of the shaft cylinder portion 51 (see FIG. 2) of the wire reel 50. An engaged portion (engaged concave portion or engaged convex portion) corresponding to the engaging portion 45 is also formed on the outer end surface (end surface on the support end side) of the reel flange 52 (see FIG. 2) of the wire reel 50. To do.

An engaging portion 46 (engaging concave portion or engaging convex portion; engaging concave portion in the figure) is provided along the axial direction on the outer peripheral surface of the rotary shaft portion 41a of the rotary cylinder 40b shown in FIG. 4 (b). Thus, the rotation shaft portion 41a is prevented from sliding in the circumferential direction with respect to the inner peripheral surface of the shaft cylinder portion 51 (see FIG. 2) of the wire reel 50. An engaged portion (engaged convex portion or engaged concave portion) corresponding to the engaging portion 46 is also formed on the inner peripheral surface of the shaft tubular portion 51 (see FIG. 2) of the wire reel 50.

The rotary shaft portion 41b of the rotary cylinder 40c shown in FIG. 4C has a taper whose outer diameter gradually increases toward the fitting direction (support end side) of the wire reel 50 to the rotary cylinder 40. This taper prevents the rotation shaft portion 41b from slipping in the circumferential direction with respect to the inner peripheral surface of the shaft cylinder portion 51 (see FIG. 2) of the wire reel 50. A taper having the same inclination as that of the rotating shaft portion 41b is also formed on the inner peripheral surface of the shaft cylinder portion 51 (see FIG. 2) of the wire reel 50.

In FIGS. 4A to 4C, the same parts as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

In addition to the compression coil spring used in the embodiment, the elastic member 60 as the thrust force applying means of the present invention includes a metal spring such as a leaf spring, a fluid spring utilizing air pressure, hydraulic pressure, etc., rubber, and plastic. It is possible to use a non-metal spring or the like. In addition, in the embodiment, the elastic member 60 is connected to the step portion 70a of the bearing member 70 (or the bottom of the recess 43) and the collar portion 8.
Although it is supported by the two stepped portions 82a, the end surface of the rotary cylinder 40 (rotary shaft portion 41) on the free end side is directly connected by an external pressing tool (for example, a hydraulic / pneumatic cylinder) or the like, or through another member. The pressure may be indirectly held.

The bearing member 70 as the thrust force receiving means of the present invention is fitted to the fixed shaft 20 as in the embodiment,
The reel support 10 (support member) can also be fitted and arranged. Further, as a thrust force receiving means, the fixed shaft 2
Alternatively, the thrust force receiving portion may be formed on 0 or the reel column 10.

In the embodiment, the screw member 80 serving as the thrust force adjusting means is formed with the male screw portion 81 and is screwed into the screw hole 23 of the fixed shaft 20, but the female screw portion is provided on the screw member 80 side. It is also possible to form a threaded portion on the fixed shaft 20 side. In addition, the screw member 80 and the pressure handle 9
Alternatively, the pressure handle 90 may be omitted and a screw member 8 may be used by using a spanner, a screwdriver, or the like.
0 may be adjusted by screwing. Further, when, for example, a hydraulic / pneumatic cylinder is used as the thrust force applying means, the thrust force S may be adjusted by adjusting the fluid supply pressure to the hydraulic / pneumatic cylinder.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a MIG welding apparatus which is an embodiment of the welding apparatus of the present invention.

FIG. 2 is a front sectional view of a wire feeding device used in the welding device of FIG.

FIG. 3 is an exploded perspective view of a main part of FIG.

FIG. 4 is a perspective view showing a modified example of the rotary cylinder of FIG.

FIG. 5 is an explanatory diagram of a general TIG welding method and a general MIG welding method.

FIG. 6 is a front sectional view of a conventional wire feeding device.

[Explanation of symbols]

1 wire feeder 10 reel support (support member) 20 fixed axis 40 rotating cylinder (cylindrical member) 43 recess 50 wire reel 60 elastic member (thrust force adding means) 70 Bearing member (thrust force receiving means) 80 Screw member (Thrust force adjusting means) 90 Pressure handle (Thrust force adjusting means) 300 MIG welding equipment (welding equipment) 301 wire (electrode wire)

Continued front page    (72) Inventor Takao Cold Water             2-30, Daido-cho, Minami-ku, Nagoya-shi, Aichi             Daido Steel Co., Ltd. Technology Development Laboratory

Claims (6)

[Claims] 1. A fixed shaft projectingly attached to a support member in a cantilever manner, a tubular member rotatably fitted to the fixed shaft from the outside, and a wire wound around the tubular member. And a wire reel that is detachably inserted and is rotatable integrally with the tubular member, and a pressing force in the thrust direction from the free end side of the fixed shaft toward the support end side of the tubular member (hereinafter A thrust force adding means for applying a thrust force), and a thrust force receiving means for contacting the tubular member to receive the thrust force added by the thrust force adding means. In the state in which the thrust force is applied to the tubular member by the means, with the pulling of the wire from the wire reel, the tubular member is
A wire feeding device which rotates integrally with the wire reel around the fixed shaft while generating a frictional force with at least the thrust force receiving means. 2. The thrust force applying means is housed in a concave portion formed from the free end side of the tubular member along the thrust direction to have a larger diameter than the fixed shaft and a predetermined depth. One end is held directly on the free end of the fixed shaft or indirectly via another member, and the other end is held on the bottom of the recess to apply the thrust force to the tubular member. The wire feeding device according to claim 1, which is an elastic member. 3. The thrust force receiving means is a bearing member that is fitted to the fixed shaft and is disposed at the bottom of the recess to hold the other end of the elastic member. The wire feeder described. 4. A screw member is attached to the fixed shaft from the free end side thereof along the thrust direction, and a screw member for holding one end of the elastic member is attached, and the screw member is fixed to the fixed shaft. The wire feeding device according to claim 2, wherein the thrust force can be adjusted by screwing the shaft with respect to the shaft. 5. A welding device, wherein the wire feeding device according to claim 1 is used as a feeding device for an electrode wire in consumable electrode type arc welding. 6. A welding method, wherein consumable electrode type arc welding is performed by using the wire feeding device according to any one of claims 1 to 4 as a feeding device for an electrode wire.