WO2020217760A1

WO2020217760A1 - Laser welding method, and laser welding device

Info

Publication number: WO2020217760A1
Application number: PCT/JP2020/010405
Authority: WO
Inventors: 山本　幸男; 智仁都藤; 聖也高橋
Original assignee: デルタ工業株式会社
Priority date: 2019-04-26
Filing date: 2020-03-10
Publication date: 2020-10-29
Also published as: JP2020179418A; JP7289509B2

Abstract

This laser welding method includes: a laser light radiating step of causing laser light to oscillate, and condensing the laser light onto a welding location; a scanning step of scanning a spot of the laser light; and a filler material feeding step of feeding a filler material into a scanning region of the spot of laser light. When carrying out laser welding: the spot is scanned in such a way as to circulate about a prescribed location, to form a welded portion in the shape of a dot in a plan view, obtained by melting a metal member; the filler material is fed to the location before the spot passes; and the filler material is removed from a molten pool before radiation of the laser light onto the welded portion ends.

Description

Laser welding method and laser welding equipment

The present invention relates to a laser welding method and a laser welding apparatus.

Laser welding technology may be used to join metal members together. Joining of metal members by laser welding is performed by melting and solidifying a part of the metal members by irradiation with laser light. When metal members are joined by laser welding, they have the advantages of higher welding speed and less heat effect than when joining by resistance welding. Further, when metal members are joined to each other by laser welding, welding can be performed without contact with the metal members, the processing efficiency is high, and the rigidity can be increased by continuous welding.

By the way, when metal members having a gap between each other are joined by laser welding in the state before welding, a large dent is formed in the welded portion, and in some cases, gouge (underfill) or melt-through occurs. Sometimes. In addition, when welding is performed in the above-mentioned state, the wall thickness of the outer peripheral portion of the welded portion becomes thin, even if it does not gouge or melt down, which is caused by quenching due to the thinning. Problems such as the formation of vulnerable tissues may occur.

For such a problem, it is conceivable to adopt the technique disclosed in Patent Document 1. In the technique disclosed in Patent Document 1, a predetermined region is irradiated with a laser beam to form a molten pool, and then a wire (filler) is brought closer to the molten pool and the tip of the wire is melted. The resulting droplets are deposited on the outer periphery of the molten pool. Then, in this technique, the molten pool in which the droplets are deposited is irradiated with laser light again to smooth the surface of the molten pool to form a welded portion.

The technique disclosed in Patent Document 1 is used to suppress thinning and fragile organization in the outer peripheral portion of a welded portion when metal members having a gap between each other are joined by laser welding in a state before welding. It is also possible to adopt it.

Japanese Unexamined Patent Publication No. 2016-179500

However, when the technique disclosed in Patent Document 1 is adopted to suppress thinning and fragile organization in the outer peripheral portion, a decrease in work efficiency becomes a problem. Specifically, in the technique disclosed in Patent Document 1, a molten pool is formed by irradiation with a laser beam, and then droplets formed by melting the tip of the wire are deposited on the molten pool, and then the laser beam is used. It is difficult to perform welding at high speed because the surface is flattened by irradiating. Therefore, when the technique disclosed in Patent Document 1 is adopted, it is considered that a decrease in work efficiency is unavoidable.

The present invention has been made to solve the above-mentioned problems, and even when there is a gap between each other in the state before welding, the metal members can be joined to each other with high bonding strength. An object of the present invention is to provide a laser welding method and a laser welding apparatus capable of joining with high work efficiency.

The laser welding method according to one aspect of the present invention is a laser welding method in which a plurality of metal members are joined by laser welding, and is a laser beam that oscillates a laser beam and concentrates the oscillated laser beam on a welded portion. It includes an irradiation step, a scanning step for scanning the spot of the laser beam, and a fillering material supply step which is made of metal and supplies a filler material which is melted by the irradiation of the laser beam into the scanning region of the spot. The laser beam spot is scanned so as to orbit around the predetermined location to form a dot-shaped welded portion in a plan view in which the metal member is melted, and before the laser beam spot passes through. The filler metal is supplied to the portion of the above, and the filler metal is separated from the molten pool formed by melting the metal member before the irradiation of the laser beam to the welded portion is completed.

It is a schematic diagram which shows the schematic structure of the laser welding apparatus which concerns on 1st Embodiment. It is a schematic side view which shows the arrangement state of the plate material before welding. It is a schematic plan view for demonstrating the laser welding method using the laser welding apparatus which concerns on 1st Embodiment. It is a schematic cross-sectional view which shows the IV-IV line cross section of FIG. It is a schematic cross-sectional view which shows the part A of FIG. 4 enlarged. It is a schematic cross-sectional view which shows the structure of the outer peripheral part of the welded part at the time of performing welding by using the laser welding method which concerns on a comparative example. It is a schematic cross-sectional view for demonstrating the laser welding method which concerns on 2nd Embodiment. It is a schematic diagram which shows the schematic structure of the laser welding apparatus which concerns on 3rd Embodiment. It is a schematic plan view for demonstrating the laser welding method which concerns on 4th Embodiment. It is a schematic plan view for demonstrating the laser welding method which concerns on 5th Embodiment. It is a schematic diagram which shows the welding form which concerns on 6th Embodiment. It is a schematic diagram which shows the welding form which concerns on 7th Embodiment. It is a schematic diagram which shows the welding form which concerns on 8th Embodiment. It is a schematic diagram which shows the welding form which concerns on 9th Embodiment. It is a schematic diagram which shows the welding form which concerns on 10th Embodiment. It is a schematic diagram which shows the welding form which concerns on 11th Embodiment.

In the following, the embodiment will be described with reference to the drawings. The forms described below are examples of the present invention, and the present invention is not limited to the following forms except for its essential configuration.

[First Embodiment]
1. 1. Schematic configuration of the laser welding apparatus 1 The schematic configuration of the laser welding apparatus 1 according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic view showing a schematic configuration of a laser welding apparatus 1 according to the present embodiment.

As shown in FIG. 1, the laser welding apparatus 1 according to the present embodiment includes a laser oscillator 10, an optical path 11, and a condensing unit (scanning unit) 12. The laser oscillator 10 oscillates the laser beam according to a command from the controller (control unit) 16 connected to the laser oscillator 10. The controller 16 includes a microprocessor composed of a CPU, ROM, RAM, and the like.

The laser beam oscillated by the laser oscillator 10 is propagated to the condensing unit 12 through the optical path 11. In the light collecting unit 12, the propagated laser light is focused (spots are formed) on the surface of the plate material (metal member) 501 in the plate material laminate 500. Then, the condensing unit 12 scans the spot of the laser beam on the surface of the plate member 501 according to the command from the controller 16.

In the present embodiment, an optical fiber cable is used as an example of the optical path 11, but in addition to this, various optical paths such as propagation by light reflection using a mirror can be adopted. Here, in the present embodiment, the plate material laminate 500 to be welded is a laminate of a plate material (metal member) 501 and a plate material (metal member) 502.

Further, the laser welding device 1 includes a welding robot 13 and a drive circuit unit 14 for driving the welding robot 13. The welding robot 13 has a condensing unit 12 attached to its tip portion, and can move the condensing unit 12 in three dimensions according to a command from the controller 16 connected to the drive circuit unit 14.

Further, the laser welding device 1 according to the present embodiment includes a wire feeder (filler supply unit) 15 attached to the tip portion of the welding robot 13. The wire feeder 15 supplies the wire 20 which is a filler material toward the welded portion. The wire feeder 15 executes the supply of the wire 20 to the welded portion and the separation of the wire 20 from the welded portion (melting pond) in accordance with the command from the controller 16.

2. Schematic configuration of the plate material laminate 500 The schematic configuration of the plate material laminate 500 will be described with reference to FIG. FIG. 2 is a schematic side view showing an arrangement state of the

plate materials

501 and 502 constituting the plate material laminate 500 before welding.

The plate material 501 and the plate material 502 are overlapped in the plate thickness direction (Z direction), but as shown in FIG. 2, there is a gap G of, for example, about 1 mm at the maximum between them before welding.

3. 3. Laser Welding Using Laser Welding Device 1 Laser welding using the laser welding device 1 according to the present embodiment will be described with reference to FIG. FIG. 3 is a schematic plan view for explaining a laser welding method using the laser welding apparatus 1.

As shown in FIG. 3, in the welding using the laser welding apparatus 1 according to the present embodiment, the controller 16 issues a command (command for executing the laser beam irradiation step) to oscillate the laser beam to the laser oscillator 10. Then, the condensing unit 12 is controlled so that the spot of the laser beam orbits around the orbiting center (predetermined location) Ax _LB1 in a substantially circular shape in a plan view. That is, the controller 16 controls the condensing unit 12 to scan the spot of the laser beam so as to execute the so-called laser screw welding in the welding of the plate material laminate 500 (execution command of the scanning step), and the welded portion. Welding and stirring of the

plate members

501 and 502 in 100 are performed.

Further, the controller 16 controls the wire feeder 15 so that the tip of the wire 20 is on the inner peripheral side of the outer edge 100b of the scanning region (welded portion 100 to be formed) of the laser beam spot.

The scanning of the spot of the laser beam according to the present embodiment is continuously performed from the inner peripheral side, which is the circumferential center Ax _LB1 side, toward the outer peripheral portion 100a, and the tip of the wire 20 is the region (outer circumference). It is supplied into the portion 100a).

Here, the controller 16 arranges the tip of the wire 20 to be located at a position where the spot of the laser beam passes, at least before the spot of the laser beam passes, and the wire 20 (of the wire 20) before the irradiation of the laser beam is completed. The part on the root side excluding the molten tip) is separated from the molten pool.

4. Form of Welded Part 100 The form of the welded part 100 formed by irradiating the laser beam as described with reference to FIG. 3 will be described with reference to FIGS. 4 to 6. FIG. 4 is a schematic cross-sectional view showing a cross section taken along line IV-IV of FIG. 3, and FIG. 5 is a schematic cross-sectional view showing an enlarged portion A of FIG. FIG. 6 is a schematic cross-sectional view showing the configuration of the outer peripheral portion of the welded portion when welding is performed by using the laser welding method according to the comparative example.

As shown in FIG. 4, the welded portion 100 formed by laser welding according to the present embodiment includes a base portion 101 formed by melting, stirring, and solidifying

plate materials

501 and 502 by irradiation with laser light. It is composed of a thickening portion 102 formed by melting, stirring, and solidifying the tip of the wire 20 by irradiation with a laser beam. A part of the molten metal also flows into the gap G, and is also formed in the gap G around the region where the base portion 101 is irradiated with the laser beam.

Although FIG. 4 is shown so that a boundary exists between the base portion 101 and the thickening portion 102 for convenience of explanation, the base portion 101 and the thickening portion 102 are actually shown. The welded portion 100 is formed integrally.

As shown in FIG. 4, in the present embodiment, the wire 20 is supplied to the outer peripheral portion 100a whose tip is on the inner peripheral side of the outer peripheral edge 100b of the scanning region (welded portion 100 to be formed) of the laser beam spot. Therefore, the tip of the wire 20 is melted by the irradiation of the laser beam and separated from the root side portion.

Next, as shown in FIG. 5, when the laser welding method according to the present embodiment is adopted, thinning of the wall thickness is suppressed in the outer peripheral portion 100a of the radial outer portion of the welded portion 100. ing. This is because the welded portion 100 is formed by the thickened portion 102 in addition to the base portion 101, and the molten metal is agitated by orbiting scanning the spot of the laser beam. Therefore, when the laser welding method according to the present embodiment is used, the thinning of the outer peripheral portion 100a is suppressed, the stress concentration is alleviated, and the rapid cooling of the portion is suppressed, resulting in a fragile structure. It is also suppressed.

On the other hand, in the case of the comparative example in which the wire was not supplied at the time of irradiation with the laser beam, as shown in FIG. 6, the wall thickness of the outer peripheral portion 900a of the welded portion 900 is the thickness of the outer peripheral portion 100a according to the present embodiment. It will be thinner than it is thick. Therefore, even if the plate thickness of the plate material 901 to be welded and the gap between the plate materials are the same as those in the present embodiment, the outer peripheral portion 900a is thinned, which causes the portion to be rapidly cooled. Vulnerable tissue may be formed in.

5. Effect In the laser welding apparatus 1 and the laser welding method using the laser welding apparatus 1 according to the present embodiment, since the plate material 501 and the plate material 502 are joined by laser welding, the welding speed is faster and the heat is higher than in the case of using resistance welding or the like. It has little influence, and welding can be performed on the

plate members

501 and 502 without contact, the processing efficiency is high, and the rigidity can be increased by continuous welding.

Further, in the laser welding apparatus 1 according to the present embodiment and the laser welding method using the laser welding apparatus 1, the spot of the laser beam is orbited around the orbiting center Ax _LB1 to melt and stir the metal member of the portion, and the welded portion. Since 100 is formed, the molten metal will flow into the gap G even if there is a gap G between the plate material 501 and the plate material 502 in the state before welding.

Further, in the laser welding apparatus 1 according to the present embodiment and the laser welding method using the laser welding apparatus 1, the tip of the wire 20 is melted by the laser beam during scanning to form a thickened portion (a part of the welded portion 100) 102. It is possible to suppress the occurrence of gouge (underfill) and melt-through in the welded portion 100 after solidification.

Further, in the laser welding apparatus 1 according to the present embodiment and the laser welding method using the laser welding apparatus 1, the wire 20 is arranged so that the tip is arranged on the laser beam scanning locus LN _LB while scanning the spot of the laser beam. Is supplied and the tip of the wire 20 is melted by irradiating the laser beam, so that the work efficiency higher than that of the technique disclosed in Patent Document 1 can be realized, in which the wire is melted in a step different from the melting of the plate material. ..

Further, in the laser welding apparatus 1 according to the present embodiment and the laser welding method using the laser welding apparatus 1, the molten metal in which the wire 20 is melted by irradiation with laser light is also combined with the molten metal in which the

plate materials

501 and 502 are melted. The surface of the molten pool is flattened by stirring by orbiting the spot of the laser beam. As described above, in the present embodiment, since the flattening of the molten pool is also performed by scanning the spots of the laser beam continuously, the droplets formed by melting the wires are deposited, and then the irradiation of the laser beam is restarted. It is possible to realize higher work efficiency than the technique disclosed in Patent Document 1 above, which flattens the surface of the molten pool.

In the laser welding apparatus 1 according to the present embodiment and the laser welding method using the same, the spot of the laser beam is spotted on the wire 20 by supplying the wire 20 to the outer peripheral portion 100a on the inner peripheral side of the outer edge 100b of the welded portion 100. By irradiating the tip of the wire 20, the wire 20 is welded at the irradiated portion of the laser beam. Therefore, the separation of the wire 20 from the molten pool can be easily controlled regardless of the supply amount of the wire 20.

[Second Embodiment]
FIG. 7 is a schematic cross-sectional view illustrating the laser welding method according to the second embodiment.

As shown in FIG. 7, in the laser welding method according to the present embodiment, the plate material (metal member) 506 and the plate material (metal member) 507 are butted in substantially orthogonal directions, and the corner portion related to the butting is laser welded to abut. This is a so-called fillet welding method for forming a coalescence 505. Also in this embodiment, there is a gap G of, for example, a maximum of about 1 mm between the plate material 506 and the plate material 507 in the state before welding.

In the laser welding method according to the present embodiment, the spot orbits around the orbital center Ax _LB2 that intersects both the extending direction (Z direction) of the plate material 506 and the extending direction (X direction) of the plate material 507. The laser beam is irradiated so as to.

Also in this embodiment, the wire 20 is supplied to the outer peripheral portion 105a whose tip is on the inner peripheral side of the outer edge of the scanning region (welded portion 105 to be formed) of the laser beam spot. In particular, in the laser welding method of the present embodiment, since the fillet welding is performed, the supply amount of the wire 20 is small, so that the amount of movement of the wire 20 related to the insertion (advance) and the separation (reverse) of the wire 20 is extremely large. Although it is slight, by supplying the wire 20 to the outer peripheral portion 105a on the inner peripheral side of the outer edge, the wire 20 can be cut (cut off) by irradiation with a laser beam, so that control is easy.

In the present embodiment, by adopting the laser welding method as described above, it is possible to form a welded portion 105 composed of a base portion 106 and a thickened portion 107. Also in this embodiment, a part of the molten metal has flowed into the gap G.

The same effect as that of the first embodiment can be obtained in this embodiment in which fillet welding is performed.

[Third Embodiment]
FIG. 8 is a schematic view showing a schematic configuration of the laser welding apparatus 2 according to the third embodiment.

As shown in FIG. 8, the laser welding apparatus 2 according to the present embodiment has a laser oscillator 10, an optical path 11, a condensing portion (scanning portion) 12, and welding, similarly to the laser welding apparatus 1 according to the first embodiment. It includes a robot 13, a drive circuit unit 14, a wire feeder (weld material supply unit) 15, and a controller (control unit) 16.

Further, the laser welding apparatus 2 according to the present embodiment includes an imaging camera (gap measuring unit) 25. The image pickup camera 25 takes an image of the boundary portion between the plate material (metal member) 511 and the plate material (metal member) 512 constituting the laminated body 510, and measures the presence or absence of a gap and its size if there is a gap. Then, the measurement result is sent to the controller 16.

In the laser welding apparatus 2 according to the present embodiment, the controller 16 receives the gap measurement result from the image pickup camera 25 and selectively supplies the wire 20 when there is a gap between the plate material 511 and the plate material 512. Controls the wire feeder 15. In other words, the controller 16 controls the wire feeder 15 so that the wire 20 is not supplied when there is no gap between the plate member 511 and the plate member 512.

Further, in the laser welding apparatus 2 according to the present embodiment, the controller 16 controls the wire feeder 15 so as to adjust the supply amount of the wire 20 according to the size of the gap between the plate material 511 and the plate material 512. .. Specifically, the controller 16 relatively increases the supply amount of the wire 20 as the gap between the plate material 511 and the plate material 512 is relatively large, and the supply amount of the wire 20 is relatively small as the gap is relatively small. The wire feeder 15 is controlled so as to reduce the number of wires.

In the laser welding apparatus 2 according to the present embodiment and the laser welding method using the same, the same effects as those of the first embodiment and the second embodiment can be obtained, and the following effects can be obtained. Obtainable.

In the laser welding apparatus 2 according to the present embodiment and the laser welding method using the same, the wire 20 is used when there is no gap between the

plate members

511 and 512 and the problem of gouge (underfill) or melt-through is unlikely to occur in the welded portion. It is possible to avoid the situation where it is supplied. As a result, by supplying the wire 20 as needed, high bonding strength can be ensured regardless of the presence or absence of a gap between the

plate members

511, 512.

Further, in the laser welding apparatus 2 and the laser welding method using the laser welding apparatus 2 according to the present embodiment, the supply amount of the wires 20 is adjusted according to the size of the gap between the

plate members

511, 512, so that the regions having different gaps are different from each other. The form of the welded portion when viewed from the irradiation side of the laser beam can be aligned between the two. Therefore, in the present embodiment, for example, it is possible to prevent the surface of the welded portion from being greatly raised by supplying a large amount of filler metal even though the gap is small. When the gap between the

plate materials

511, 512 is large, by controlling the supply amount of the wire 20 to be large, it is possible to fill the gap with a sufficient amount of molten metal, and the plate materials are high. The joint strength can be ensured.

[Fourth Embodiment]
FIG. 9A is a schematic plan view for explaining the laser welding method according to the fourth embodiment.

As shown in FIG. 9A, also in the laser welding method according to the present embodiment, with respect to the surface of one of the plate materials (metal members) to be welded, the circumferential center (predetermined location) Ax _LB3 is the center. The spot of the laser beam is scanned so as to go around and the laser beam is irradiated. As a result, the metal member of the portion irradiated with the laser beam is melted and agitated to form a welded portion 110 having a substantially rounded polygonal shape (in this embodiment, a rounded quadrangle as an example) in a plan view. Then, also in this embodiment, the wire 20 is supplied to the outer peripheral portion of the region (welded portion 110) for scanning the spot of the laser beam.

The laser welding method according to the present embodiment is different from the first embodiment to the third embodiment in that the spot of the laser beam is scanned into a polygon with rounded corners.

Even with the laser welding method as described above, the same effect as that of the first embodiment can be obtained.

[Fifth Embodiment]
FIG. 9B is a schematic plan view for explaining the laser welding method according to the fifth embodiment.

As shown in FIG. 9B, also in the laser welding method according to the present embodiment, with respect to the surface of one of the plate materials (metal members) to be welded, the circumferential center (predetermined location) Ax _LB4 is the center. The spot of the laser beam is scanned so as to go around and the laser beam is irradiated. As a result, the metal member of the portion irradiated with the laser beam is melted and agitated to form the welded portion 115 having a substantially elliptical plan view. Then, also in the present embodiment, the wire 20 is supplied to the outer peripheral portion of the region (welded portion 115) for scanning the spot of the laser beam.

[Sixth Embodiment]
FIG. 10A is a schematic view showing a welding mode according to the sixth embodiment.

As shown in FIG. 10A, in the laser welding method according to the present embodiment, by performing laser welding, a screw portion 121 having a substantially circular shape in a plan view and a linear shape continuous with the screw portion 121 and extending in a plane line of sight in the X direction. A welded portion (nugget) 120 composed of a portion 122, a screw portion 123 which is continuous with the linear portion 122 and has a substantially circular shape in a plan view, is formed.

The screw portion 121 and the screw portion 123 are formed by scanning the spot of the laser beam so as to orbit around a predetermined location, as in the first embodiment. In the present embodiment, the linear portion 122 is continuously irradiated with the laser beam before the metal member of the screw portion 121 solidifies, and the other one is performed before the metal member of the linear portion 122 solidifies. Irradiation of the laser beam to the screw portion 123 is continuously performed.

Although detailed illustration is omitted in FIG. 10A, the wire (filler) is supplied so that the tip is arranged in the scanning region of the spot of the laser beam.

In the laser welding method according to the present embodiment, in addition to the same effect as that of the first embodiment and the like, the following effects can be obtained.

In the laser welding method according to the present embodiment, before the metal member of the screw portion 121 solidifies, the linear portion 122 is continuously irradiated with the laser beam, and before the metal member of the linear portion 122 solidifies. Since the laser beam is continuously irradiated to the screw portion 123, even if there is a gap between the overlapped metal members in the state before welding, the screw portion 121 is formed and melted. In addition to the metal member, the molten metal formed by melting the wire flows into the gap between the members of the portion where the linear portion 122 is to be formed. Therefore, in the present embodiment, even when there is a gap between the metal members, not only the screw portion but also the linear portion can be joined with high strength.

Further, also in the laser welding method according to the present embodiment, as in the first embodiment and the like, a wire (filler) is supplied at the time of forming the

screw portions

121 and 123, and the melted wire is one of the welded portions 120. Since it is a portion, it is possible to suppress the occurrence of gouge (underfill) or melt-off in the welded portion 120 after solidification.

Further, also in the laser welding method according to the present embodiment, since the wire is supplied on the scanning locus of the spot and the tip of the wire is melted while scanning the spot of the laser beam, the plate material (metal member) can be used. It is possible to realize higher work efficiency than the technique disclosed in Patent Document 1 above, in which the wire is melted in a step different from the melting.

Further, in the laser welding method according to the present embodiment, the molten metal obtained by melting the wire by irradiating the laser beam is also stirred together with the molten metal formed by melting the plate material (metal member) by orbiting scanning the spot of the laser beam. The surface of the molten pool is flattened.

[7th Embodiment]
FIG. 10B is a schematic view showing a welding mode according to the seventh embodiment.

As shown in FIG. 10B, in the laser welding method according to the present embodiment, by performing laser welding, a screw portion 126 having a substantially circular shape in a plan view and a linear portion 127 continuous with the screw portion 126 and extending in a plane line of sight , A welded portion (nugget) 125 composed of a screw portion 128 which is continuous with the linear portion 127 and has a substantially circular shape in a plan view is formed.

The laser welding method according to this embodiment is basically the same as that of the sixth embodiment.

However, as shown in FIG. 10B, the linear portion 127 of the welded portion 125 according to the present embodiment is different from the sixth embodiment in the connection points with respect to the screw portion 126 and the screw portion 128. That is, in the welded portion 125 according to the present embodiment, the linear portion 127 is connected so as to form a tangent line at one radial end portion (outer edge portion in the Y direction) of each of the screw portion 126 and the screw portion 128. ing.

The welding method according to the present embodiment can obtain the same effect as that of the sixth embodiment.

[8th Embodiment]
FIG. 10C is a schematic view showing a welding mode according to the eighth embodiment.

As shown in FIG. 10C, in the laser welding apparatus according to the present embodiment, by performing laser welding, a screw portion 131 having a substantially circular shape in a plan view and a linear portion 132 continuous with the screw portion 131 and extending in a plane line of sight , The screw portion 133 which is continuous with the linear portion 132 and is substantially circular in plan view, the linear portion 134 which is continuous with the screw portion 133 and extends in a plane line of sight, and the screw portion 135 which is continuous with the linear portion 134 and is substantially circular in plan view. And the welded portion (nugget) 130 including. Although FIG. 10C shows an example of forming a welded portion 130 composed of three

screw portions

131, 133, 135 and two

linear portions

132, 134, the screw portion and the linear portion are further continuous. Of course, it is also possible to form a screw.

The formation of the

screw portions

131, 133, 135 and the

linear portions

132, 134 is the same method as in the sixth embodiment and the seventh embodiment.

The laser welding method according to the present embodiment can also obtain the same effects as those of the sixth embodiment and the seventh embodiment. Further, in the present embodiment, the welding speed is increased by forming the welded portion 130 including

more screw portions

131, 133, 135 and

linear portions

132, 134 than in the sixth embodiment and the seventh embodiment. It is possible to secure higher joint strength while increasing the speed.

[9th Embodiment]
FIG. 11A is a schematic view showing a welding mode according to the ninth embodiment.

As shown in FIG. 11A, in the laser welding apparatus according to the present embodiment, by performing laser welding, a screw portion 141 having a substantially circular shape in a plan view and a linear portion 142 continuous with the screw portion 141 and extending in a plane line of sight , To form a welded portion (nugget) 140 composed of.

Each of the screw portion 141 and the linear portion 142 is formed by the same method as in the sixth to eighth embodiments. Further, also in the laser welding method according to the present embodiment, similarly to the sixth to eighth embodiments, when the welded portion 140 is formed, the linear portion is formed before the metal member of the screw portion 141 solidifies. Irradiation of the laser beam to 142 is continuously performed.

In the laser welding method according to the present embodiment, the same effect as that of the sixth embodiment can be obtained.

[10th Embodiment]
FIG. 11B is a schematic view showing a welding mode according to the tenth embodiment.

As shown in FIG. 11B, in the laser welding apparatus according to the present embodiment, by performing laser welding, a screw portion 146 having a substantially circular shape in a plan view and a linear portion 147 continuous with the screw portion 146 and extending in a plane line of sight , To form a welded portion (nugget) 145.

In the laser welding method according to the present embodiment, the connection portion of the linear portion 147 of the welded portion 145 to the screw portion 146 is different from that of the ninth embodiment, and one end portion (Y direction) in the radial direction of the screw portion 146 is provided. It is connected so as to extend in the tangential direction at the outer edge).

The screw portion 146 and the linear portion 147 are formed by the same method as in the sixth to ninth embodiments. Further, also in the laser welding method according to the present embodiment, as in the case of the sixth to ninth embodiments, when the welded portion 145 is formed, the linear portion is formed before the metal member of the screw portion 146 solidifies. Irradiation of the laser beam to the 147 is continuously performed.

[11th Embodiment]
FIG. 11C is a schematic view showing a welding mode according to the eleventh embodiment.

As shown in FIG. 11C, in the laser welding apparatus according to the present embodiment, the screw portion 152 having a substantially circular shape in a plan view is separated from the screw portion 152 toward one side in the radial direction of the screw portion 152 by laser welding. a flat sight line shape of the line portion 151 as extending (as indicated by the arrow B ₂₎ is, (as indicated by arrow B ₁₎ to be separated toward the screw portion 152 on the other side of the radially extending plane A line-of-sight linear portion 153 and a welded portion 150 composed of the linear portion 153 are formed.

The screw portions 152 and the

linear portions

151 and 153 are formed by the same method as in the sixth to tenth embodiments. Further, in the present embodiment, both the start of the laser welding at the linear portion 151 and the start of the laser welding at the linear portion 153 are performed before the molten metal of the screw portion 152 solidifies.

[Modification example]
Hereinafter, a laser welding apparatus according to a modified example and a laser welding method using the same will be described.

As the laser welding apparatus according to this modification, the laser welding apparatus 1 according to the first embodiment or the laser welding apparatus 2 according to the second embodiment is adopted.

In this modification, the metal member to be welded is made of a metal material containing carbon. Specifically, a metal member made of carbon steel is targeted for welding. Further, in this modification, the wire as a filler material is also made of a metal material containing carbon.

Then, in this modification, a wire whose carbon equivalent is set according to the carbon equivalent of the metal member to be welded is supplied. Specifically, a wire having a relatively small carbon equivalent is supplied when the carbon equivalent of the metal member to be welded is relatively large, and the carbon equivalent is relative when the carbon equivalent of the metal member is relatively small. Is supplied with a large wire.

In this modification, when the carbon equivalent of the metal member to be welded is relatively large, the carbon content of the molten pool is diluted by supplying a wire with a relatively small carbon equivalent, and the structure becomes brittle. On the contrary, when the carbon equivalent of the metal member is relatively small, the carbon content of the molten pool is increased by supplying a filler material having a relatively large carbon equivalent to improve the strength of the weld. Can be planned.

In this modification, as an example, the magnitude of the carbon equivalent of the wire is changed with the case where the carbon equivalent of the metal member is 0.25% as a threshold value.

[Other variants]
In the first to eleventh embodiments, the condensing unit 12 is controlled to scan the spot of the laser beam, but the present invention is not limited thereto. For example, the laser beam spot may be scanned by driving and controlling the tip portion of the welding robot 13, or the laser beam spot may be scanned using an XY table or the like. Further, in the first to eleventh embodiments, the condensing unit 12 is controlled to move the spot of the laser beam, but the present invention is not limited to this. For example, the metal member to be welded may be moved to scan the spot of the laser beam. Further, if the welding is in a certain range, welding to a desired position can be performed only by scanning the light collecting unit 12 without using the welding robot 13.

Further, in the first to eleventh embodiments, the two metal members are joined to each other, but the present invention is not limited to this. For example, if the present invention is applied to join three or more metal members, the same effect as described above can be obtained.

Further, in the laser welding apparatus 2 according to the third embodiment, the presence or absence of a gap and the size of the gap are measured by the imaging camera 25, but the present invention is not limited to this. For example, the gap may be measured by ultrasonic waves or the like.

Further, the welded portion is irradiated with a laser beam for measurement, and the depth of the depression formed by welding the surface of the welded portion (distance between the laser beam irradiation surface of the metal member in the state before welding and the surface of the welding pond during welding). ) Is further provided in a depth measuring unit for measuring (performing a measurement step) in real time, and is adjusted to the measured depth of the recess (the depth before the wire is irradiated with the laser beam). The amount of wire (weld material) to be supplied may be controlled.

Further, in the present invention, it is also possible to apply the above-mentioned first embodiment to the above-mentioned eleventh embodiment in combination with each other.

[Summary]
The laser welding method according to one aspect of the present invention is a laser welding method in which a plurality of metal members are joined by laser welding, and the laser light is oscillated and the oscillated laser light is focused on a welded portion. It includes an irradiation step, a scanning step for scanning the spot of the laser beam, and a filler material supply step which is made of metal and supplies a filler material which is melted by the irradiation of the laser beam into the scanning region of the spot. The laser beam spot is scanned so as to orbit around the predetermined location to form a dot-shaped welded portion in a plan view in which the metal member is melted, and before the laser beam spot passes through. The filler metal is supplied to the portion of the above, and the filler metal is separated from the molten pool formed by melting the metal member before the irradiation of the laser beam to the welded portion is completed.

First, in the laser welding method according to the above aspect, since a plurality of metal members are joined by laser welding, the welding speed is faster, the thermal influence is less, and the metal member is less affected than the case where resistance welding or the like is used. Welding can be performed in a non-contact manner, processing efficiency is high, and rigidity can be increased by continuous welding.

Next, in the laser welding method according to the above aspect, by executing the scanning step, the spot of the laser beam is circulated around the predetermined portion to melt and stir the metal member of the portion to form the welded portion. Therefore, even if there is a gap between the metal members in the state before welding, the molten metal will flow into the gap between the metal members.

Further, in the laser welding method according to the above aspect, by executing the filler material supply step, the filler metal is melted by the laser beam during scanning to be a part of the welded portion, so that the welded portion is scooped out after solidification. It is possible to suppress the occurrence of (underfill) and melting off.

Further, in the laser welding method according to the above aspect, the filler metal is supplied on the scanning locus of the spot while scanning the spot of the laser beam (during the execution of the scanning step) to melt the filler metal. Therefore (because the filler material supply step is executed), it is possible to realize a higher work efficiency than the technique disclosed in Patent Document 1 above, in which the filler metal is melted in a step different from the melting of the metal member.

Further, in the laser welding method according to the above aspect, the molten metal obtained by melting the filler metal by irradiating the laser beam is also agitated and melted by orbiting scanning of the spot of the laser beam together with the molten metal formed by melting the metal member. The surface of the pond is flattened. As described above, in the laser welding method according to the above aspect, the flattening of the molten pool is also performed by scanning the spots of the laser beam continuously, so that the laser beam is irradiated after the droplets formed by melting the filler metal are deposited. It is possible to realize higher work efficiency than the technique disclosed in the above-mentioned Patent Document 1 in which the above-mentioned is restarted to flatten the surface.

Therefore, in the laser welding method according to the above aspect, the metal members are joined together with high joining strength and high working efficiency even when there is a gap between them in the state before welding. Is possible.

In the laser welding method according to the above aspect, when the welded portion is viewed in a plan view from the irradiation direction of the laser beam, the fillering material is supplied to the inner peripheral side of the outer edge of the welded portion, and the fillering material is supplied. It is also possible to adopt a configuration in which the tip of the material is melted by passing the spot of the laser beam and is separated from the portion on the root side of the tip.

When the above configuration is adopted, the filler metal is supplied to the inner peripheral side of the outer edge of the welded portion, so that the spot of the laser beam passes through the filler metal and is welded at the passing portion. The material will be welded. Therefore, the separation of the filler metal from the molten pool can be easily controlled regardless of the amount of the filler metal supplied.

In the laser welding method according to the above aspect, a gap measuring step for measuring a gap between the metal members is further provided, and the filler metal is selectively supplied when the gap is open. It is also possible to adopt the configuration of.

When the above configuration is adopted, it is possible to avoid a situation in which the filler metal is undesirably supplied even when there is no gap between the metal members and the problem of gouge or melt-through is unlikely to occur in the welded portion. be able to.

In the laser welding method according to the above aspect, in the filler material supply step, it is possible to adopt a configuration in which the supply amount of the filler metal is relatively large as the gap is relatively large.

When the above configuration is adopted, the supply amount of the filler material is relatively increased as the gap is relatively large, in other words, the supply amount of the filler material is adjusted according to the size of the gap. Therefore, the form of the welded portion when viewed from the irradiation side of the laser beam can be made uniform between the regions having different gaps. Therefore, when the above configuration is adopted, it is possible to realize high appearance quality of the welded portion while ensuring high joint strength. For example, if a large amount of filler metal is supplied even though the gap is small, a welded portion having a large raised surface will be formed. By adopting the above configuration, such a welded portion will be formed. You can avoid such a situation.

In the laser welding method according to the above aspect, a measuring step for measuring the depth to the surface of the molten pool formed by melting the metal member is further provided, and in the fillering material supply step, the filler metal is described as described above. It is also possible to adopt a configuration in which the supply amount of the filler metal is relatively increased as the depth is relatively deep before the laser beam is irradiated.

Here, the "depth to the surface of the molten pool" in the above is the distance between the laser beam irradiation surface of the metal member in the state before welding and the surface of the welding pond during welding.

When the above configuration is adopted, the filler metal is welded according to the magnitude of the depth before the laser beam is irradiated to the filler metal, in other words, the state before the filler metal is melted. Since the supply amount of the material is adjusted, the depth can be set to a predetermined predetermined depth regardless of the size of the gap between the metal members. Therefore, when the above configuration is adopted, it is possible to realize high appearance quality of the welded portion while ensuring high joint strength.

In the laser welding method according to the above aspect, a metal containing carbon is used for each of the filler metal and the metal member, and the carbon equivalent of the filler metal has a relatively large carbon equivalent of the base metal. It is also possible to adopt a configuration in which the carbon equivalent of the base metal is set to be relatively small, and the carbon equivalent of the base metal is set to be relatively large.

When the above configuration is adopted, the carbon equivalent of the base metal is relatively large, the carbon equivalent is reduced by supplying the filler material, so that the carbon content of the molten pool is diluted and the structure becomes brittle. On the contrary, by supplying a filler material having a larger carbon equivalent as the carbon equivalent of the base material is relatively smaller, the carbon content of the molten pool is increased and the strength of the joint (welded portion) is improved. Can be planned.

The laser welding apparatus according to one aspect of the present invention is a laser welding apparatus that joins a plurality of metal members by laser welding, and is a laser oscillator that oscillates a laser beam and a condensing device that focuses the laser beam on a welded portion. A unit, a scanning unit that scans the spot of the laser beam, a filler material supply unit that is made of metal and supplies a filler material that is melted by irradiation of the laser beam into the scanning region of the spot, and the laser oscillator. The scanning unit and the control unit for controlling the filler material supply unit are provided, and the control unit scans the spot of the laser beam around a predetermined location so as to orbit the metal. The laser oscillator and the scanning portion are controlled so as to form a dot-shaped welded portion in a plan view in which the members are melted, and the filler metal is supplied to a portion before the spot of the laser beam passes. Before the irradiation of the laser beam to the welded portion is completed, the filler material supply portion is controlled so that the filler metal is separated from the molten pool formed by melting the metal member.

First, in the laser welding apparatus according to the above aspect, since a plurality of metal members are joined by laser welding, the welding speed is faster, the thermal influence is less, and the metal members are less affected than in the case of using resistance welding or the like. Welding can be performed in a non-contact manner, processing efficiency is high, and rigidity can be increased by continuous welding.

Next, in the laser welding apparatus according to the above aspect, the spot of the laser beam is circulated around the predetermined portion to melt and stir the metal member of the portion to form the welded portion. Even if there is a gap between the metal members in this state, the molten metal will flow into the gap between the metal members.

Further, in the laser welding apparatus according to the above aspect, since the filler metal is melted by the laser beam during scanning to be a part of the welded portion, gouge (underfill) or melt-through occurs in the welded portion after solidification. It can be suppressed.

Further, in the laser welding apparatus according to the above aspect, while scanning the spot of the laser beam, the filler material is supplied on the scanning locus of the spot to melt the filler metal. It is possible to realize higher work efficiency than the technique disclosed in Patent Document 1 above, in which the filler metal is melted in another step.

Further, in the laser welding apparatus according to the above aspect, the molten metal obtained by melting the filler metal by irradiating the laser beam is also agitated and melted by orbiting scanning of the spot of the laser beam together with the molten metal formed by melting the metal member. The surface of the pond is flattened. As described above, in the laser welding apparatus according to the above aspect, the flattening of the molten pool is also performed by scanning the spots of the laser beam continuously, so that the laser beam is irradiated after the droplets formed by melting the filler metal are deposited. It is possible to realize higher work efficiency than the technique disclosed in Patent Document 1 above, in which the above is resumed to flatten the surface.

Therefore, in the laser welding apparatus according to the above aspect, the metal members are joined together with high joining strength and high working efficiency even when there is a gap between them in the state before welding. Is possible.

In the laser welding apparatus according to the above aspect, when the welded portion is viewed in a plan view from the irradiation direction of the laser beam, the filler material is supplied to the inner peripheral side of the outer edge of the welded portion, and the fillering material is supplied. It is also possible to adopt a configuration in which the tip of the material is melted by passing the spot of the laser beam and is separated from the portion on the root side of the tip.

The laser welding apparatus according to the above aspect further includes a gap measuring unit that measures a gap between the metal members and sends the measurement result to the control unit, and the control unit determines that the gap is open. In this case, it is possible to adopt a configuration in which the filler metal is supplied to the filler metal supply unit.

When the above configuration is adopted, the filler metal is undesirably supplied even when there is no gap between the metal members and the problem of gouge (underfill) or melt-through is unlikely to occur in the welded portion. You can avoid such a situation.

In the laser welding apparatus according to the above aspect, the control unit controls the filler material supply unit so that the supply amount of the filler material becomes relatively large as the gap is relatively large. A configuration can also be adopted.

The laser welding apparatus according to the above aspect further includes a depth measuring unit for measuring the depth to the surface of the molten pool formed by melting the metal member, and the control unit provides the laser with respect to the filler metal. The structure is such that the filler metal supply unit is controlled so that the supply amount of the filler metal is relatively large as the depth is relatively deep before the light is irradiated. It can also be adopted.

When the above configuration is adopted, the filler metal is welded according to the magnitude of the depth before the laser beam is irradiated to the filler metal, in other words, the state before the filler metal is melted. Since the supply amount of the material is adjusted, the above depth can be set to a predetermined predetermined depth regardless of the size of the gap between the metal members. Therefore, when the above configuration is adopted, it is possible to realize high appearance quality of the welded portion while ensuring high joint strength.

As described above, in each of the above embodiments, the metal members are joined together with high joining strength and high working efficiency even when there is a gap between them in the state before welding. Is possible.

Claims

A laser welding method in which a plurality of metal members are joined by laser welding.
A laser beam irradiation step that oscillates the laser beam and condenses the oscillated laser beam on the welded part.
A scanning step of scanning the spot of the laser beam and
A filler material supply step made of metal and supplying a filler metal which is melted by irradiation with a laser beam into the scanning region of the spot,
With
The spot of the laser beam is scanned so as to orbit around the predetermined portion to form a dot-shaped welded portion in a plan view in which the metal member is melted, and before the spot of the laser beam passes through. The filler metal is supplied to the portion, and the filler metal is separated from the molten pool formed by melting the metal member before the irradiation of the laser beam to the welded portion is completed.
Laser welding method.
In the laser welding method according to claim 1,
When the welded portion is viewed in a plan view from the irradiation direction of the laser beam, the filler metal is supplied to the inner peripheral side of the outer edge of the welded portion.
The tip of the filler metal is melted by passing the spot of the laser beam and separated from the portion on the root side of the tip.
Laser welding method.
In the laser welding method according to claim 1 or 2.
A gap measurement step for measuring the gap between the metal members is further provided.
The filler material is selectively supplied when the gap is open.
Laser welding method.
In the laser welding method according to claim 3,
In the filler material supply step, the larger the gap is, the larger the supply amount of the filler metal is.
Laser welding method.
In the laser welding method according to claim 1 or 2.
Further provided with a measuring step for measuring the depth to the surface of the molten pool formed by melting the metal member.
In the filler material supply step, the relatively deeper the filler metal in the state before the laser beam is irradiated to the filler metal, the larger the supply amount of the filler metal. ,
Laser welding method.
In the laser welding method according to any one of claims 1 to 5.
A metal containing carbon is used for each of the filler metal and the metal member.
The carbon equivalent of the filler metal is set to be relatively small as the carbon equivalent of the base material is relatively large, and to be relatively large as the carbon equivalent of the base material is relatively small.
Laser welding method.
A laser welding device that joins multiple metal members by laser welding.
A laser oscillator that oscillates laser light and
A condensing unit that collects the laser light on the welded part,
A scanning unit that scans the spot of the laser beam,
A filler material supply unit made of metal and supplying a filler material melted by irradiation with a laser beam into the scanning region of the spot,
A control unit that controls the laser oscillator, the scanning unit, and the filler material supply unit,
With
The control unit scans the spot of the laser beam around a predetermined location so as to orbit around the spot, and forms the welded portion in the shape of dots in a plan view in which the metal member is melted. While controlling the scanning unit, the filler metal is supplied to a portion before the spot of the laser beam passes, and the filler metal is supplied to the welded portion before the irradiation of the laser beam to the welded portion is completed. The filler metal supply unit is controlled so as to be separated from the molten pool formed by melting the metal member.
Laser welding equipment.
In the laser welding apparatus according to claim 7.
When the welded portion is viewed in a plan view from the irradiation direction of the laser beam, the filler metal is supplied to the inner peripheral side of the outer edge of the welded portion.
The tip of the filler metal is melted by passing the spot of the laser beam and separated from the portion on the root side of the tip.
Laser welding equipment.
In the laser welding apparatus according to claim 7 or 8.
A gap measuring unit that measures the gap between the metal members and sends the measurement result to the control unit is further provided.
When the control unit determines that the gap is open, the control unit supplies the filler material to the filler material supply unit.
Laser welding equipment.
In the laser welding apparatus according to claim 9,
The control unit controls the filler material supply unit so that the supply amount of the filler material becomes relatively large as the gap is relatively large.
Laser welding equipment.
In the laser welding apparatus according to claim 7 or 8.
A depth measuring unit for measuring the depth to the surface of the molten pool formed by melting the metal member is further provided.
In the control unit, the deeper the filler material is in the state before the laser beam is irradiated, the larger the supply amount of the filler metal is. Controlling the filler material supply unit,
Laser welding equipment.