JP6741547B2 - Welding method - Google Patents

Description

The present invention relates to a welding method, for example, a welding method suitable for application to arc welding such as MIG welding.

Conventionally, as an arc welding method, for example, there is an arc welding method described in Patent Document 1. This method is a non-consumable electrode type arc welding method (TIG welding method) performed by feeding a filler material while weaving the non-consumable electrode in the left-right direction of the welding advancing direction. To and from the weaving center line without moving back and forth to the left and right. Further, at least one of the welding current value and the filler material feeding speed is increased during the reciprocating movement of the non-consumable electrode in the left-right direction. Examples of the torch weaving locus include the locus shown in FIG. 3 of Patent Document 1 and FIG. 7 of Patent Document 2.

Japanese Patent No. 3827658 JP 2004-141939 A

By the way, the arc welding method described in Patent Document 1 is a so-called TIG welding method. The TIG welding method has the advantages that spatter is hardly generated, the bead appearance is flat and beautiful, and internal defects are hardly generated.

However, the TIG welding method has problems that the welding speed is slow and the welding efficiency is low. Further, since there are many setting parameters such as the insertion angle of the welding wire, there is a problem in that automation requires a high cost.

On the other hand, there is a MIG welding method in which an arc is generated between a welding wire (welding torch) that is automatically fed and a base material, the welding wire is melted together with the base material, and a welding bead is formed in the groove. is there. This MIG welding method has the advantages that the welding speed is fast and the welding efficiency is high, and furthermore, there are also the advantages that the automation is easy because there are few setting parameters.

However, the MIG welding method has a problem that spatter is likely to occur, a convex bead is likely to occur, and an internal defect is likely to occur.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a welding method that can obtain the advantages of the TIG welding method and the advantages of the MIG welding method.

[1] A welding method according to the present invention comprises welding a first welded member and a second welded member having a smaller plate thickness than the first welded member in a welding direction along a groove portion. A welding method of performing arc welding of the first and second members to be welded while relatively moving the torch, wherein an operation trajectory of the welding torch with respect to a groove portion of the first and second members to be welded is , Each of which is an arcuate motion trajectory, and the amplitude of the motion trajectory on the side of the first welded member is other than that with the position closer to the first welded member from the center of the groove portion as a boundary. The distance between the position and the ridgeline of the first welded member is smaller than the amplitude of the motion trajectory, and the distance between the ridgeline of the first welded member and the ridgeline of the second welded member is 3/10. It is characterized in that it is 4/10 or less.

The present invention includes, for example, a welding torch that performs arc welding on two members to be welded, a welding robot that operates the welding torch, a wire feeding device, and a control device that controls the operation and current and voltage of the welding robot. It is suitable to be applied to a welding device provided, for example, a MIG welding device.

Then, according to the present invention, arc welding is performed by a welding torch on the groove portions of two members to be welded having different plate thicknesses. In this case, welding is performed by changing the arcs to the groove portions of at least two members to be welded and the operation trajectories of the welding torch to the groove portions of the two members to be welded, respectively, depending on the plate thickness.

Thereby, the welding volume of the welding member (welding bead) can be obtained according to the size of the groove of the two members to be welded, and the quality of the bead shape and the welding strength can be improved. Moreover, since the welding can be performed by the MIG welding method, the advantages of the MIG welding, that is, the welding speed is fast, the penetration depth is deep, the welding efficiency is high, and the automation is easy, are enjoyed. You can
The movement trajectory of the welding torch for the workpiece with a large thickness is assigned a small amplitude trajectory corresponding to the large thickness, and the trajectory of the welding torch for a workpiece with a small thickness corresponds to the small thickness. A large orbital motion trajectory is assigned.
As a result, for example, an arcuate motion trajectory having a large curvature is assigned to a welded member having a large plate thickness, and an arcuate motion trajectory having a small curvature is assigned to a welded member having a small plate thickness. ..
As a result, a scale-shaped bead having a good appearance can be formed on the groove portions of the two members to be welded. This leads to improvement in welding strength. Good appearance means (1) each scale shape has a wrap rate of 2/3 or more, and the wrap rate is substantially uniform, (2) bead width of each scale shape is substantially uniform, and (3) bead It is preferable that the bead shape is welded with a meandering width of 1 mm or less.

[2] In the present invention, the diameter of the welding wire supplied through the welding torch is selected, and the supply amount (supply amount) of the welding wire according to the cross-sectional areas of the groove portions of the two members to be welded is determined. Widen the setting range and perform welding.

As a result, it is possible to set the optimum feed amount of the welding wire according to the cross-sectional areas of the groove portions of the two members to be welded, and improve the shape quality of the beads formed in the groove portions, welding strength, etc. Can be made.

[3] In the present invention, it is preferable that, of the two members to be welded, the arc to a member to be welded having a large plate thickness is large and the arc to a member to be welded having a small plate thickness is small to perform welding.

The arc to the two members to be welded also leads to the selection of the feed amount of the welding wire. By increasing the arc to the member to be welded with a large plate thickness and reducing the arc to the member to be welded with a small plate thickness, it becomes possible to widen the range of setting the supply amount (feed amount) of the welding wire. It is possible to improve the shape quality of the beads formed in the groove portion, the welding strength, and the like. Moreover, since it is not necessary to apply a large arc to the two members to be welded, the base material does not melt down.

[ 4 ] In this case, the movement trajectory for the welded member having a large plate thickness is a trajectory along a part of a circular circumference (arc shape), and the movement trajectory for the welded member having a small plate thickness is It is preferable that the trajectory is along a part of the circumference of the elliptical shape (described as an elliptical shape).

As a result, an arcuate motion trajectory with a small pitch is assigned to a member to be welded with a large plate thickness, and an elliptical motion trajectory with a large pitch is assigned to a member to be welded with a small plate thickness. As a result, a scale-shaped bead having a good appearance can be formed on the groove portions of the two members to be welded. This leads to improvement in welding strength.

[ 5 ] In the present invention, depending on the cross-sectional areas of the groove portions of the two members to be welded, at least the supply amount of the welding wire, the arc to the groove portions of the two members to be welded, and the welding torch. It is preferable to set a motion trajectory and perform welding.

With this, it is possible to supply the welding wire in an amount necessary for welding to the groove portion without supplying an unnecessarily large current to the base metal, and to the appearance of the groove portion. It is possible to form good beads.

[ 6 ] In the present invention, the arc welding may be completed by welding the first layer to the groove portion of the two members to be welded in a state where the joint between the members to be welded is not machined. preferable.

As a result, since the joint is not machined and the second layer is not welded, the cycle time can be significantly reduced. Moreover, a bead having a good appearance can be formed on the groove portion.

[ 7 ] In the present invention, the welding wire is preferably a welding wire used in MIG welding.

Since the welding can be performed by the MIG welding method, the advantages of the MIG welding, that is, the welding speed is high, the penetration depth is deep, the welding efficiency is high, and the automation is easy can be enjoyed. ..

[ 8 ] In the present invention, it is preferable to set the center line of the operation trajectory of the welding torch based on the teaching of the reference side welded member among the two welded members. As a result, a bead having a good appearance can be formed without causing excess or deficiency of build-up of the bead on the groove portion.

According to the welding method of the present invention, the advantages of the TIG welding method and the advantages of the MIG welding method can be obtained as follows.
(I) Spatter hardly occurs.
(Ii) The appearance of the bead is flat and beautiful.
(Iii) The welding speed is fast.
(Iv) The welding efficiency is high.
(V) Since there are few setting parameters, automation is easy.

It is a perspective view which shows an example of the to-be-welded member (work piece) weld-processed by the welding method which concerns on this Embodiment. It is sectional drawing which cuts and shows a workpiece|work by the surface (YZ plane) perpendicular|vertical to a welding line. FIG. 3A is a block diagram showing the configuration of a welding apparatus that realizes the welding method according to the present embodiment, and FIG. 3B shows a state in which a bead is formed in the groove between the first work portion and the second work portion by welding. FIG. It is a flow chart which shows a part of welding processing performed by a control part. 5A is a cross-sectional view showing a cross section of the work together with a welding torch when the first work part is the reference side (fixed side) and the second work part is the insertion side (matching component side), and FIG. 5B is the opening of the work. It is a top view which abbreviate|omits a part and shows an example of the movement trajectory of the welding torch to a front part. FIG. 6A is a sectional view showing the cross section of the work together with the welding torch when the second work part is the reference side (fixed side) and the first work part is the insertion side (matching part side), and FIG. 6B is the opening of the work. It is a top view which abbreviate|omits a part and shows an example of the movement trajectory of the welding torch to a front part. FIG. 7A is an explanatory diagram showing an example of the external shape of a scale-shaped bead formed along the welding direction, FIG. 7B is an explanatory diagram showing the bead wrap rate, and FIG. 7C is a meandering width of the bead. FIG. FIG. 8A is a plan view showing another example of the movement trajectory of the welding torch to the groove portion of the work with some parts omitted, and FIG. 8B is a sectional view thereof. 9A is a sectional view showing a groove portion having the maximum gap width in the work, FIG. 9B is a sectional view showing a groove portion having a narrow gap width in the work, and FIG. 9C is a narrow gap width. FIG. 7 is a cross-sectional view showing inconveniences when the motion trajectory is set based on the groove portion of FIG. It is explanatory drawing which shows the area of the shape which cut|disconnected the groove part of a workpiece|work by the plane orthogonal to a welding direction (X direction).

Hereinafter, embodiments of the welding method according to the present invention will be described with reference to FIGS. 1 to 10.

First, in the welding method according to the present embodiment, as shown in FIG. 1, arc welding is performed on two members to be welded (first welded member 12A and second welded member 12B) having different plate thicknesses. To do. The first welded member 12A and the second welded member 12B are collectively referred to as a work 10, the first welded member 12A is referred to as a first work portion 12A, and the second welded member 12B is referred to as a second work portion 12B. Sometimes referred to.

The work 10 is made of, for example, aluminum or iron, and has a first work portion 12A and a second work portion 12B whose ends are welded to each other. The geometric quantity is measured along the weld line along the mutually adjacent ends of the first work portion 12A and the second work portion 12B. The work 10 is, for example, a motorcycle frame. In the XYZ coordinate system used in the following description, the welding direction is the positive direction of the X axis, the positive direction of the Y axis is the right direction with respect to the welding direction (the positive direction), and the positive direction of the Z axis is the X direction. It is a direction orthogonal to the axis and the Y axis. Various directions such as a vertical direction, a horizontal direction, and a diagonal direction are assumed as the positive direction of the Z axis. In this specification, in order to simplify the description, the positive direction of the Z axis is the upward direction, but the present invention is not limited to this.

FIG. 2 is a cross-sectional view showing the work 10 cut along a plane perpendicular to the welding line (YZ plane). Here, the average plate thickness ta of the first work portion 12A is larger than the average plate thickness tb of the second work portion 12B (ta>tb).

As shown in FIG. 2, the first work portion 12A having a large plate thickness includes a first portion 14a having a large plate thickness and a second portion 14b having a small plate thickness integrally provided at the tip of the first portion 14a. Have. The second work portion 12B has a flat plate shape having a substantially constant thickness.

The second work portion 12B having a small plate thickness is overlapped with the second portion 14b of the first work portion 12A, so that the side surface 16 (slope) of the first portion 14a of the first work portion 12A and the second portion 14b. A groove portion 22 defined by the upper surface 18 and the side surface 20 (slope) of the second work portion 12B is formed. The cross-sectional shape of the groove 22 is trapezoidal or triangular. In FIG. 2, as the dimensions of the groove portion 22, for example, the upper clearance Wa is 5 to 14 mm, the lower clearance Wb is 0 to 3 mm, and the height h is 5 mm. These dimensions are merely examples, and various dimensions suitable for arc welding can be adopted.

The boundary 24 between the side surface 16 of the first portion 14a of the first work portion 12A and the upper surface 18 of the second portion 14b and the edge 26 of the second work portion 12B (the sloped surface 16 of the first portion 14a of the first work portion 12A). The first gap Ga is formed as a distance in the Y-axis direction between the first gap Ga and the edge. The first gap Ga is the same as the gap Wb on the lower side of the groove portion 22. A second gap Gb is formed as a distance in the Z-axis direction between the lower surface 28 of the second work portion 12B and the upper surface 18 of the second portion 14b of the first work portion 12A.

Then, as shown in FIGS. 3A and 3B, welding device 100 that realizes the welding method according to the present embodiment is provided with a control unit 102 that controls each unit of welding device 100 and an instruction to control unit 102. An operation unit 104, a welding torch 108 for welding the work 10, a wire supply unit 114 for supplying a welding wire 112 to the welding torch 108, and a gas supply unit 116 for supplying a shield gas to the welding torch 108. , A welding robot 118 that holds and moves the welding torch 108, and a welding power source 119 that supplies a welding current to the welding robot 118.

The welding robot 118 includes a robot body 120 (one unit) and a positioner 122 (one unit). The positioner 122 holds and positions the work 10 directly or via a jig. The welding torch 108 is operated by the robot body 120. That is, the control unit 102 controls the robot body 120 and the positioner 122 to cooperate with each other to perform welding work.

FIG. 4 is a flowchart showing a part of the welding process executed by the control unit 102. In this welding process, the first work portion 12A and the second work portion 12B are welded while forming the welding bead 124 (see FIG. 3B) by MIG welding in the groove portion 22 which is the welding target portion of the work 10. In particular, MIG welding is performed with the weld bead 124 having a good appearance.

That is, in step S1 of FIG. 4, the control unit 102 sets welding conditions for performing MIG welding on the groove portion 22 which is the welding target portion. The welding conditions include the setting of the operation trajectory (path) of the welding torch 108 and the like. Then, in step S2, MIG welding is performed on the groove portion 22 according to the set welding conditions.

The groove portion 22 sets the welding conditions of the groove portion 22 by teaching with reference to the groove portion 22 of the reference side (fixed side) work part.

For example, as shown in FIG. 5A, when the first work portion 12A is the reference side (fixed side) and the second work portion 12B is the insertion side (matching component side), the first work portion 12A that is the reference side is opened. Teaching is performed using the tip 22 as a reference to set the welding conditions for the groove 22. The ridgeline forming the groove 22 of the first work portion 12A is referred to as a first ridgeline 126a.

Further, for example, as shown in FIG. 6A, if the second work portion 12B is the reference side (fixed side) and the first work portion 12A is the insertion side (matching component side), the second work portion 12B that is the reference side. Teaching is performed using the groove portion 22 as a reference, and the welding conditions of the groove portion 22 are set. The ridgeline forming the groove 22 of the second work portion 12B is referred to as a second ridgeline 126b.

Particularly, in the welding method according to the present embodiment, at least the arc to the first work portion 12A and the second work portion 12B and the welding to the first work portion 12A and the second work portion 12B are performed depending on the plate thickness of the work 10. Welding is performed by changing the operation trajectory of the torch 108.

In the present embodiment, specifically, MIG welding is performed by the following methods (A) to (F).

(A) As shown in FIG. 3B, the diameter Dw (diameter) of the welding wire 112 supplied through the welding torch 108 is changed so that the cross-sectional area of the groove 22 of the first work portion 12A and the second work portion 12B is changed. Welding is performed by widening the selection range of the supply amount (feed amount) of the welding wire 112 according to the above. Thereby, the optimal feed amount of the welding wire 112 can be set according to the cross-sectional area of the groove portion 22 of the first work portion 12A and the second work portion 12B, and the bead formed on the groove portion 22 can be set. The shape quality of 124, welding strength, etc. can be improved.

(B) Welding is performed with a large arc to the first work portion 12A having a large plate thickness and a small arc to the second work portion 12B having a small plate thickness.

The arc to the first work portion 12A and the second work portion 12B also leads to the setting of the feed amount of the welding wire 112. By widening the arc to the first work portion 12A having a large plate thickness and reducing the arc to the second work portion 12B having a small plate thickness, the setting range of the supply amount (supply amount) of the welding wire 112 is widened. This makes it possible to improve the shape quality, welding strength, etc. of the bead 124 formed in the groove portion 22. Moreover, since it is not necessary to increase the arcs to the first work portion 12A and the second work portion 12B together, the base material of the work 10 does not melt down.

(C) For example, as shown in FIGS. 5B and 6B, the movement paths 128 of the welding torch 108 (see FIGS. 5A and 6A) with respect to the groove portion 22 between the first work portion 12A and the second work portion 12B are respectively shown. The movement trajectory 128 has an arc shape. In this case, with the position Pa closer to the first work portion 12A than the center of the groove portion 22 (the center line of the movement trajectory of the welding torch 108) as a boundary, the amplitude Aa of the first movement trajectory 128a on the first work portion 12A side. Is smaller than the amplitude Ab of the second motion trajectory 128b on the second work portion 12B side.

For example, as shown in FIG. 5A, when the first work portion 12A is on the reference side (fixed side), the distance between the first ridge line 126a of the first work portion 12A and the second ridge line 126b of the second work portion 12B is L. At this time, the position having the following relationship is defined as position Pa.
(A) The distance from the first ridge 126a to the position Pa is A×L
(B) The distance from the second ridge 126b to the position Pa is B×L
(C) B>A, A+B=1
(D) A=3/10 to 4/10, B=6/10 to 7/10
Preferably, A=4/10, B=6/10

As a result, as shown in FIG. 5B, the first work path 128a having the small amplitude Aa corresponding to the large plate thickness is assigned to the first work portion 12A having the large plate thickness, and the second work having the small plate thickness is assigned. The second movement trajectory 128b having a large amplitude Ab corresponding to the small plate thickness is assigned to the portion 12B.

Further, for example, as shown in FIG. 6A, when the second work portion 12B is on the reference side (fixed side), the distance between the first ridge line 126a of the first work portion 12A and the second ridge line 126b of the second work portion 12B is set to be the same. When L is set, a position having the following relationship is set as position Pa.
(E) The distance from the first ridge 126a to the position Pa is C×L
(F) The distance from the second ridge 126b to the position Pa is D×L
(G) D>C, C+D=1
(H) C=3/10 to 4/10, B=6/10 to 7/10
Preferably, C=4/10, D=6/10

As a result, as shown in FIG. 6B, the first work portion 12A having a large plate thickness is assigned the first motion trajectory 128a having a small amplitude Aa corresponding to the large plate thickness, and the second work having a small plate thickness is allocated. The second movement trajectory 128b having a large amplitude Ab corresponding to the small plate thickness is assigned to the portion 12B.

In other words, of the groove portion 22, with the position Pa closer to the first work portion 12A than the center of the groove portion 22 as a boundary, to the first portion 14a side (see FIG. 2) of the first work portion 12A. On the other hand, an arcuate motion trajectory having a large curvature is assigned, and to other portions (the upper surface 18 of the second portion 14b and the side surface 20 of the second work portion 12B), an arcuate motion trajectory having a smaller curvature is assigned. Is assigned.

As a result, as shown in FIG. 7A, the bead 124 having a shape in which a large number of scale shapes 124a are arranged in the welding direction (for example, the X direction) so as to partially overlap (wrap) with respect to the groove portion 22. Is formed, and in particular, the bead 124 having a good appearance can be formed without excess or deficiency of the buildup of the bead 124 with respect to the groove portion 22. This leads to improvement in welding strength. Good appearance means that the following conditions are satisfied, for example.

(1) For example, as shown in FIG. 7B, it is preferable that the wrap ratio of each scale shape 124a (scale-shaped lap length La/scale-shaped diameter Da) is 4/6 or more and 5/6 or less.

(2) For example, as shown in FIG. 7C, the meandering width Wt of the bead 124 is preferably within 1 mm.

(D) As shown in FIGS. 8A and 8B, in the groove portion 22, a first Pa of the first work portion 12A is defined with a position Pa closer to the first work portion 12A than the center of the groove portion 22 as a boundary. The third motion trajectory 128c with respect to the portion 14a side is a trajectory along a part of a circular circumference (semi-circular shape or arc shape), and the fourth motion trajectory 128d of other portions is an elliptical circumference. It is a trajectory along a part (semi-elliptical or elliptical arc).

For example, as shown in FIG. 8B, in the groove portion 22, with respect to the position Pa closer to the first work portion 12A than the center of the groove portion 22 as a boundary, with respect to the first portion 14a side of the first work portion 12A. A third movement trajectory 128c having a small amplitude Aa and having a semi-circular shape or an arc shape is assigned to the other portions, and a fourth movement trajectory 128d having a large amplitude Ab having a semi-elliptical shape or an elliptic arc shape is assigned to other portions. To be

The operation of the welding torch 108 is, for example, as shown in the order of (1)→(2)→(3)→(4)→(5) in FIG. 8A, from the third movement trajectory 128c to the fourth movement trajectory 128d. May be performed, or as shown in the order of (4)→(3)→(2)→(1)→(5), the operation may be from the fourth motion trajectory 128d to the third motion trajectory 128c. Of course, other orders may be used.

As a result, the scale-shaped bead 124 having a good appearance described above can be formed on the groove portion 22. This leads to an improvement in welding strength as in the case of (c) above.

(E) As shown in FIG. 9A, the motion trajectory shown in (C) and (D) above is based on the groove portion 22 having the maximum gap width Wmax among the groove portions 22 formed in the work 10. To set.

As shown in FIG. 9B, when the operation trajectory is set based on the groove portion 22 having the narrow gap width Wc, as shown in FIG. 9C, welding is performed on the groove portion 22 having the wider gap width Wd. If this is done, problems such as uneven distribution of the beads 124 may occur, such as the side portions of the beads 124 falling into the groove portions 22.

However, as described above, by setting the motion trajectory based on the groove portion 22 having the maximum gap width Wmax among the groove portions 22 formed on the work 10, the groove with the narrow gap width Wc is set. Regardless of the portion 22 or the groove portion 22 having the maximum gap width Wmax, the width of the bead 124 can be made substantially uniform over the entire groove portion 22 without the side portion of the bead 124 dropping. The appearance quality of can be improved.

(F) According to the cross-sectional area of the groove 22 between the first work portion 12A and the second work portion 12B, at least the supply amount of the welding wire 112 (see FIG. 3B), the first work portion 12A and the second work portion. Welding is performed by setting an arc to 12B and an operation trajectory of the welding torch 108.

Here, the cross-sectional area of the groove 22 is, as shown in FIG. 10 (cross-sectional view), an area of a shape obtained by cutting the groove 22 in the YZ plane, that is, a plane orthogonal to the welding direction (X direction). Say. In the example of FIG. 10, the cross-sectional shape of the groove portion 22 shows a case where the upper bottom is a lower part and the lower bottom is a upper part.

This makes it possible to supply the welding wire 112 to the groove portion 22 in an amount necessary for welding without supplying an unnecessarily large current to the base material of the work 10, and moreover, the groove portion. A bead 124 having a good appearance can be formed for 22.

By satisfying the above-mentioned (A) to (F), between the first work portion 12A and the second work portion 12B in a state in which the joint of the first work portion 12A and the second work portion 12B is not machined. Arc welding can be completed only by welding the first layer to the groove portion 22.

That is, since the joint is not machined in advance and the second layer is not welded, the cycle time can be significantly reduced. Moreover, it is possible to form, on the groove portion 22, the bead 124 having a good external appearance, whose appearance quality is almost the same as that of the bead 124 formed by TIG welding.

Moreover, in the welding method according to the present embodiment, the above-described arc welding is performed by MIG welding using the welding apparatus 100. Therefore, the merit of MIG welding, that is, the welding speed is high and the penetration depth is high. The advantages are that the depth is high, the welding efficiency is high, and the automation is easy.

As described above, in the welding method according to the present embodiment, the merits of the TIG welding method and the merits of the MIG welding method can be obtained as follows.

(I) Spatter hardly occurs.
(Ii) The appearance of the bead is flat and beautiful.
(Iii) The welding speed is fast.
(Iv) The welding efficiency is high.
(V) Since there are few setting parameters, automation is easy.

The present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be freely modified without departing from the spirit of the present invention.

10... Work 12A... 1st work part 12B... 2nd work part 22... Groove part 100... Welding device 108... Welding torch 112... Welding wire 118... Welding robot 124... Bead 124a... Scale shape 128a-128d... 1st operation Orbit ~ 4th motion orbit

Claims (8)

While relatively moving the welding torch in the welding direction along the groove portion of the first member to be welded and the second member to be welded having a smaller plate thickness than the first member to be welded, the first, A welding method for performing arc welding of a second member to be welded,
The movement trajectories of the welding torch with respect to the groove portions of the first and second members to be welded are arc-shaped movement trajectories, respectively.
With a position closer to the first member to be welded from the center of the groove portion as a boundary, the amplitude of the operation track on the side of the first member to be welded is smaller than the amplitudes of the other operation tracks,
The distance between the position and the ridgeline of the first welded member is 3/10 or more and 4/10 or less of the distance between the ridgeline of the first welded member and the ridgeline of the second welded member. A welding method characterized by the above. The welding method according to claim 1,
Select the diameter of the welding wire supplied through the welding torch,
A welding method, characterized in that welding is performed by widening a setting range of a supply amount of the welding wire according to a cross-sectional area of a groove portion of the two members to be welded. The welding method according to claim 1 or 2,
Among the two members to be welded, the welding is performed by increasing the arc to the member to be welded having a large plate thickness and reducing the arc to the member to be welded having a small plate thickness. The welding method according to any one of claims 1 to 3,
The movement trajectory for the welded member having a large plate thickness is a trajectory along a part of a circular circumference (arc shape),
The welding method, wherein the motion trajectory for a member to be welded having a small plate thickness is a trajectory along a part of an elliptical circumference (referred to as an ellipse). The welding method according to any one of claims 1 to 4,
Depending on the cross-sectional areas of the groove portions of the two members to be welded, welding is performed by setting at least the supply amount of the welding wire, the arc to the groove portions of the two members to be welded, and the operation trajectory of the welding torch. Welding method characterized by performing. The welding method according to any one of claims 1 to 5,
A welding method, wherein the arc welding is completed by welding the first layer to the groove portion of the two members to be welded in a state where the joint between the two members to be welded is not machined. The welding method according to any one of claims 1 to 6,
A welding method, wherein the welding wire is a welding wire used in MIG welding. The welding method according to any one of claims 1 to 7,
Of the two members to be welded, a welding method is characterized in that the center line of the operation trajectory of the welding torch is set based on the teaching of the member to be welded on the reference side.

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