Laser welding device and laser welding method

Abstract

The laser welding device comprises: a welding head (1) for irradiating a laser (6) to a processing point; a shielding gas supply nozzle (4) for supplying a shielding gas (16) to a processing point (8); and a high-speed air supply nozzle (3) for supplying a high-speed air (15) having a flow rate greater than the supply flow rate of the shielding gas (16) between the shielding gas supply nozzle (4) and the welding head (1) in a horizontal direction or in a direction orthogonal to the irradiation direction of the laser (6) directly above the shielding gas (16) supplied to the processing point (8). The high-speed air supply nozzle (3) supplies the high-speed air (15) in a band shape within a range of 80 mm to 200 mm above the processing point (8) or less than half of a working distance (WD), wherein the working distance (WD) is the distance between the irradiation surface (11) of the laser (6) of the welding head (1) and the processing point (8).

Description

[0001] This application is a divisional application of the invention patent application with the application date of April 11, 2017, application number 201780030101.5, and invention name “Laser welding device and laser welding method”. Technical Field

[0002] The present invention relates to a laser welding device and a laser welding method for welding objects by irradiating laser light. Background Art

[0003] In a laser welding device that welds a welding object by irradiation of a laser, it is necessary to protect the optical components in the welding head from being affected by smoke and spatters from the welding object. Therefore, a laser welding device having a high-speed air supply nozzle that supplies high-speed air directly below the welding head is used. In addition, in order to prevent oxidation of the welding object, a laser welding device having a shielding gas supply nozzle that supplies an inert gas as a shielding gas is used. The laser welding device is provided with a low-speed air supply nozzle between the high-speed air supply nozzle and the shielding gas supply nozzle to prevent the high-speed air from diffusing the shielding gas. The laser welding device uses a low-speed air supply nozzle to make the low-speed air flow on the shielding gas, thereby preventing the diffusion of the shielding gas caused by the high-speed air (for example, refer to patent document 1).

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-263276 Summary of the invention

[0007] An object of the present invention is to provide a laser welding device that prevents oxidation of a weld point, significantly reduces consumption of shielding gas, and protects an optical system in a welding head from being affected by smoke and spatter.

[0008] The laser welding device of the present invention comprises: a welding head, which irradiates a laser to a processing point; a shielding gas supply nozzle, which supplies shielding gas to the processing point; and a high-speed air supply nozzle, which supplies high-speed air with a flow rate greater than the supply flow rate of the shielding gas between the shielding gas supply nozzle and the welding head, in a horizontal direction or in a direction substantially orthogonal to the irradiation direction of the laser directly above the shielding gas supplied to the processing point. The high-speed air supply nozzle is located above the processing point within a range of 80 mm to 200 mm or less than half of the working distance, and supplies the high-speed air in a band shape, wherein the working distance is the distance between the irradiation surface of the laser of the welding head and the processing point.

[0009] According to the laser welding device of the present invention, the shielding gas supplied from the shielding gas supply nozzle is used to prevent oxidation of the welding object. In addition, the high-speed air supplied from the high-speed air supply nozzle flowing just above the shielding gas supply nozzle is used to remove the smoke and spatter rising from the shielding gas, thereby suppressing the refraction of the laser light or the change of the focal position caused by the smoke and spatter. Therefore, the oxidation of the processing point of the welding object can be suppressed. Therefore, a good weld can be obtained.

[0010] The high-speed air flowing directly above the shielding gas removes the smoke and sputtering rising from the shielding gas from the laser optical axis. Therefore, the amount of shielding gas used can be greatly reduced, which is economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a diagram showing a schematic configuration of a laser welding device in which a shielding gas supply nozzle and a high-speed air supply nozzle according to the first embodiment of the present invention are mounted on a welding head.

[0012] Figure 2 This is a diagram showing a schematic configuration of a laser welding device in which a shielding gas supply nozzle and a high-speed air supply nozzle according to Embodiment 1 of the present invention are mounted on a welding jig.

[0013] Figure 3 This is a diagram showing the relationship between the shielding gas flow rate of the shielding gas supply nozzle and the height of the high-speed air supply nozzle from the processing point in the first embodiment of the present invention.

[0014] Figure 4A It is a diagram showing an example of the shape of the ejection ports of the high-speed air supply nozzle and the shielding gas supply nozzle in the first embodiment of the present invention.

[0015] Figure 4B This is a diagram showing another example of the shapes of the ejection ports of the high-speed air supply nozzle and the shielding gas supply nozzle in the first embodiment of the present invention.

[0016] Figure 4C This is a diagram showing still another example of the shapes of the ejection ports of the high-speed air supply nozzle and the shielding gas supply nozzle in the first embodiment of the present invention.

[0017] Description of Reference Numerals

[0018] 1 Welding head

[0019] 2 Low speed air supply nozzles

[0020] 3 High-speed air supply nozzles

[0021] 4 Shielding gas supply nozzle

[0022] 5 Welding objects

[0023] 6 Laser

[0024] 7 Smoke

[0025] 8 Processing Points

[0026] 9 Nozzle height adjustment unit

[0027] 10. Condenser lens

[0028] 11 Protective glass

[0029] 12 Depth of penetration

[0030] 13 Welding direction

[0031] 14 Low speed air

[0032] 15 High-speed air

[0033] 16 Protective gas

[0034] 17 On / Off Valve

[0035] 18 Welding fixture

[0036] 19 Angle adjustment unit

[0037] 20 Irradiation direction DETAILED DESCRIPTION

[0038] Before describing the embodiment of the present invention, problems in conventional laser welding devices will be briefly described.

[0039] The laser welding device of Patent Document 1 supplies low-speed air between the high-speed air and the shielding gas that supplies high-speed air directly below the welding head. This prevents the shielding gas from being diffused by the high-speed air. However, when the laser welding device of Patent Document 1 performs remote welding with a long working distance and the welding head being far from the processing point (e.g., about 250 mm or more), the smoke and spatter rising from the processing point may cause adverse effects such as laser refraction and laser focus position change. In the laser welding device of Patent Document 1, there is a problem that a large amount of expensive shielding gas is consumed in order to eliminate this adverse effect.

[0040] (Implementation Method 1)

[0041] use Figure 1 Embodiment 1 will be described with reference to FIG. 4 .

[0042] Figure 1 This is a diagram showing a schematic configuration of a laser welding device in which a shielding gas supply nozzle and a high-speed air supply nozzle according to the first embodiment of the present invention are mounted on a welding head. Figure 2This is a diagram showing a schematic configuration of a laser welding device in which a shielding gas supply nozzle and a high-speed air supply nozzle according to Embodiment 1 of the present invention are mounted on a welding jig.

[0043] like Figure 1 , Figure 2 As shown, the laser welding device of the present embodiment includes a welding head 1, a shielding gas supply nozzle 4, and a high-speed air supply nozzle 3. The welding head 1 emits a laser beam 6 focused by a focusing lens 10 disposed inside the laser welding device toward a processing point 8. The shielding gas supply nozzle 4 supplies a shielding gas 16 to the processing point 8 on the processing point side. The high-speed air supply nozzle 3 supplies high-speed air 15 between the shielding gas supply nozzle 4 and the welding head 1. The high-speed air supply nozzle 3 supplies high-speed air 15 having a flow rate (e.g., 100 L / min to 200 L / min) greater than the flow rate (e.g., 20 L / min to 40 L / min) of the shielding gas 16 near the shielding gas supply nozzle 4 for blowing away the fumes 7 and spatters from the processing point 8 rising from the shielding gas atmosphere.

[0044] This can avoid adverse effects such as the laser light 6 irradiated from the welding head 1 toward the processing point 8 being refracted by the smoke 7 and spatters and changing the focal distance, thereby achieving sufficient penetration depth 12 during welding.

[0045] Figure 3 : is a diagram showing the relationship between the shielding gas flow rate of the shielding gas supply nozzle 4 and the height H of the high-speed air supply nozzle 3 from the processing point 8 in the first embodiment of the present invention. Figure 3 The relationship shown here shows that the welding result is in an appropriate range. Figure 3 The welding degree results are indicated by ○ and ×. Visual confirmation is performed, and ○ indicates a good weld appearance, and × indicates a poor weld appearance and a low penetration. The welding conditions are as follows. The working distance WD corresponding to the focal distance between the irradiation surface of the laser 6 of the welding head 1 and the processing point 8 is 330 mm, the flow rate of the high-speed air 15 of the high-speed air supply nozzle 3 is 90 L / min, the shielding gas is nitrogen, and the material of the welding object 5 is stainless steel.

[0046] When the height H of the high-speed air supply nozzle 3 (the distance from the processing point 8) is 80 mm, when the shielding gas flow rate is less than 10 L / min, a large amount of spatter is generated, and the weld bead appearance is poor (×) and insufficient penetration occurs. When the shielding gas flow rate is 10 L / min or more and 40 L / min or less, the weld bead appearance is good (○).

[0047] When the height H of the high-speed air supply nozzle 3 is 120 mm and 160 mm, when the shielding gas flow rate is less than 30 L / min, a large amount of spatter is generated, and the weld bead appearance is poor (×) and insufficient penetration occurs. When the shielding gas flow rate is 30 L / min or more and 40 L / min or less, the weld bead appearance is good (○).

[0048] When the height H of the high-speed air supply nozzle 3 is 200 mm, when the shielding gas flow rate is less than 40 L / min, a large amount of spatter is generated, and the weld bead appearance is poor (×) and insufficient penetration occurs. When the shielding gas flow rate is 40 L / min, the weld bead appearance is good (○).

[0049] When the shielding gas flow rate exceeded 40 L / min at any height H of the high-speed air supply nozzle, the cooling effect of the shielding gas supply resulted in insufficient penetration and poor weld appearance (×).

[0050] When the height H of the high-speed air supply nozzle 3 is less than 80 mm and high-speed air is supplied, the shielding gas atmosphere of the shielding gas supply is affected, which may cause a decrease in the protection of the processing point 8. When the height H of the high-speed air supply nozzle 3 exceeds 200 mm and high-speed air is supplied, the removal effect of the spatters is low because it is far away from the processing point 8 where the spatters are generated, which may cause an increase in the adhesion of smoke and spatters to the welding head 1.

[0051] Figure 4A It is a diagram showing an example of the shape of the ejection ports of the high-speed air supply nozzle and the shielding gas supply nozzle in the first embodiment of the present invention. Figure 4B It is a diagram showing another example of the shape of the ejection ports of the high-speed air supply nozzle and the shielding gas supply nozzle. Figure 4C This is a diagram showing still another example of the shapes of the ejection ports of the high-speed air supply nozzle and the shielding gas supply nozzle.

[0052] The cross-sectional shape of the high-speed air supply nozzle 3 and the flow rate of the high-speed air 15 are determined in such a way that the high-speed air 15 crosses the optical axis of the laser 6 so that the smoke can be removed sufficiently. The shape of the nozzle of the high-speed air supply nozzle 3 is formed in a long strip (long strip) in the irradiation direction 20 of the laser 6 from the welding head 1 toward the processing point 8. The shape of the nozzle of the high-speed air supply nozzle 3 is Figure 4A Single layer or Figure 4B and Figure 4C Multiple layers shown.

[0053] The nozzle of the high-speed air supply nozzle 3 can be as follows Figure 4BAs shown in FIG. 1 , narrow slits are arranged in the irradiation direction 20 (long side direction of the strip) of the laser 6. Figure 4C As shown, the small holes are arranged in a matrix shape in the irradiation direction 20 of the laser light 6 .

[0054] The high-speed air supply nozzle 3 is not limited to being composed of a single body. It can also be composed of a combination of multiple nozzles in a strip-shaped manner in the irradiation direction 20 of the laser 6. Thus, it is possible to irradiate the laser 6 in the irradiation direction 20 (from the welding head 1 to the processing point 8) with the laser 6. Figure 1 , 2 The long strip-shaped shape formed in the vertical direction (in the vertical direction) is in a direction intersecting or orthogonal to the irradiation direction 20, in other words, in a direction substantially orthogonal to the irradiation direction of the laser 6 ( Figure 1 , 2 High-speed air is blown in the horizontal direction (in the horizontal direction). As a result, smoke and spatter on the optical axis of the laser 6 that have an adverse effect on welding can be effectively removed, and the refraction of the laser 6 or the change in the focal position caused by smoke 7 and spatter can be suppressed. In addition, the protective effect of the shielding gas 16 sprayed toward the processing point 8 will not be hindered.

[0055] Since the smoke, spatter, and the like can be removed at a position away from the welding head 1 , the protective glass 11 has a great effect of protecting the laser irradiation port from which the laser beam 6 is irradiated from the welding head 1 .

[0056] The shielding gas supply nozzle 4 has an angle adjustment portion 19 for adjusting the ejection angle α of the shielding gas 16. The high-speed air supply nozzle 3 ejects high-speed air 15 as compressed air in a horizontal direction or a direction substantially perpendicular to the irradiation direction 20 of the laser 6 directly above the shielding gas 16 supplied to the processing point 8 (on the welding head 1 side of the irradiation direction 20). The relative angle α formed by the shielding gas supply nozzle 4 ejecting the shielding gas 16 toward the processing point 8 and the high-speed air supply nozzle 3 is greater than 20 degrees and less than 70 degrees.

[0057] The angle adjustment unit 19 facilitates adjustment of the spray angle of the shielding gas 16 toward the processing point 8 , and adjustment can be made so that the blowing of the high-speed air 15 does not hinder the shielding effect of supplying the shielding gas 16 to the processing point 8 .

[0058] When the angle α is less than 20 degrees, the angle between the shielding gas supply nozzle 4 and the high-speed air supply nozzle 3 is too small, and the distance between the ejected shielding gas 16 and the high-speed air 15 is close. Therefore, the shielding gas 16 is diffused under the action of the high-speed air 15, the shielding effect is hindered, and the processing point 8 is easily oxidized. When the angle α exceeds 70 degrees, the angle between the shielding gas supply nozzle 4 and the high-speed air supply nozzle 3 is too large, and the shielding gas 16 is injected close to the vertical relative to the processing point 8. Therefore, it is difficult for the shielding gas 16 injected to the processing point 8 to flow in the direction opposite to the welding direction 13, that is, the shielding gas 16 is difficult to flow in the opposite direction of the welding direction 13, that is, the rear of the processing point 8 irradiated with the laser 6. Therefore, the shielding gas 16 is insufficiently supplied to the weld bead behind the processing point 8 that has not yet completed cooling and solidification by irradiating the laser 6 to weld the processing point 8, and the shielding effect of the shielding gas 16 is reduced, and the processing point 8 is easily oxidized.

[0059] The shielding gas supply nozzle 4 is configured to be, for example, cylindrical in shape, and to have a mesh-like mesh with a plurality of openings formed in a mesh shape at a nozzle for ejecting the shielding gas 16, and is made of a raw material such as copper or brass having a laser reflectivity higher than 80% with respect to the laser 6 having a wavelength of 900 nm or more and 1100 nm or less. Therefore, even when the laser 6 is reflected from the processing point 8, damage such as deformation can be prevented. Thus, the shielding gas supply nozzle 4 can be brought closer to the processing point 8. Therefore, the shielding gas 16 can be effectively supplied toward the processing point 8.

[0060] By providing a mesh member (not shown) at the jet port of the shielding gas supply nozzle 4 for ejecting shielding gas (in other words, arranging the mesh member near the nozzle opening portion as the jet port), the shielding gas is rectified. As a result, the protection of the processing point 8 is improved. A nozzle height adjustment unit 9 is provided for assembling the shielding gas supply nozzle 4 and the high-speed air supply nozzle 3 and adjusting the position of at least one of the shielding gas supply nozzle 4 and the high-speed air supply nozzle 3 relative to the processing point 8. As a result, even when welding the processing point 8 outside the focal position of the laser 6, the shielding gas supply nozzle 4 can be arranged near the processing point 8. Therefore, the protection effect will not be reduced.

[0061] Laser welding equipment can be used as Figure 1 As shown in the figure, the welding head 1 has a nozzle height adjustment part 9, which can also be Figure 2As shown in the figure, a nozzle height adjustment unit 9 is provided on the welding jig 18 side that fixes the welding object 5 at a predetermined position. The nozzle height adjustment unit 9 can be selected according to the processing object. When the shape of the welding object 5 as the processing object is simple, by attaching the nozzle height adjustment unit 9 to the welding head 1, the low-speed air supply nozzle 2, the high-speed air supply nozzle 3, and the shielding gas supply nozzle 4 can be moved together with the welding head 1 as a set of supply nozzles in accordance with the position of the processing point 8 of the welding object 5. In this case, the low-speed air supply nozzle 2 is provided in the welding head 1. The high-speed air supply nozzle 3 and the shielding gas supply nozzle 4 are provided in the nozzle height adjustment unit 9. Therefore, the initial cost of the device can be suppressed. On the contrary, when the shape of the welding object 5 is complex, the high-speed air supply nozzle 3 and the shielding gas supply nozzle 4 provided in the nozzle height adjustment unit 9 are provided as a set of supply nozzles in accordance with the position of the processing point 8 of the welding object 5, and one or more sets of nozzle height adjustment units 9 are attached to the welding jig 18 side. As a result, the restriction on the range of motion of the welding head 1 is reduced. Therefore, processing can be performed with the head inclination and working distance of the welding head 1 more suitable for the shape of the welding object 5 .

[0062] At least the shielding gas supply nozzle 4 and the high-speed air supply nozzle 3 mounted on the welding head 1 are preferably arranged to be able to rotate relative to the optical axis of the laser 6 according to the welding travel direction, i.e., the welding direction 13, which is the direction in which the welding head 1 moves during welding, so that the ejection direction of the shielding gas 16 and the high-speed air 15 is opposite to the welding direction 13.

[0063] The shielding gas supply nozzle 4, the high-speed air supply nozzle 3, and the low-speed air supply nozzle 2 are referred to as supply nozzles. In the rotation of the supply nozzles corresponding to the welding direction 13, when the wind direction of the supply nozzles is the same, the effect of removing the spatter generated at the processing point 8 is high, which is more preferable. In other words, the supply nozzle mounted on the welding head 1 is preferably configured to be rotatable relative to the optical axis of the laser 6 irradiated to the processing point 8 according to the welding direction 13.

[0064] Thus, even when the laser 6 is scanned at high speed in the welding direction 13, which is the welding advancing direction, the shielding gas can be always supplied from any direction because it is configured to prevent the high-speed air 15 and the like from being ejected in the welding advancing direction, so that a stable weld bead can be formed. In addition, since the supply nozzle is always arranged in front of the welding head 1 with respect to the welding advancing direction, it is also easy to generate a welding program that avoids contact with the welding fixture 18.

[0065] The laser welding device is also provided with a low-speed air supply nozzle 2 that supplies low-speed air 14 from directly below the welding head 1 in a direction that does not disturb the shielding gas 16, separately from the high-speed air supply nozzle 3. Specifically, the low-speed air supply nozzle 2 is provided near the laser irradiation port of the welding head 1 that irradiates the laser 6. The low-speed air supply nozzle 2 supplies low-speed air 14 at a low flow rate (for example, 50 L / min or more and 100 L / min or less) to suppress the adhesion of smoke and spatters to the protective glass 11 provided on the surface irradiated with the laser 6 from the welding head 1. In other words, the high-speed air supply nozzle 3 is arranged between the low-speed air supply nozzle 2 and the shielding gas supply nozzle 4. The low-speed air 14 is used to prevent the adhesion of smoke 7 and spatters to the protective glass 11.

[0066] The ejection direction of the low-speed air 14 of the low-speed air supply nozzle 2 is preferably set in the same manner as the shielding gas supply nozzle 4 and the high-speed air supply nozzle 3, so that the ejection direction of the shielding gas 16 and the high-speed air 15 can be rotated relative to the optical axis of the laser 6 according to the welding travel direction, i.e., the welding direction 13, which is the direction in which the welding head 1 moves during welding.

[0067] An on-off valve 17 is provided for supplying shielding gas 16 and high-speed air 15 in coordination with the timing of irradiating laser beam 6 to a plurality of processing points 8 of welding object 5. Thus, consumption of shielding gas 16 and high-speed air 15 can be suppressed.

[0068] As described above, the laser welding device of the present embodiment includes: a welding head 1 that irradiates the laser 6 to the processing point 8; a shielding gas supply nozzle 4 that supplies the shielding gas 16 to the processing point 8; and a high-speed air supply nozzle 3 that supplies the high-speed air 15 having a flow rate greater than the supply flow rate of the shielding gas 16 between the shielding gas supply nozzle 4 and the welding head 1, in a horizontal direction or in a direction substantially perpendicular to the irradiation direction 20 of the laser 6, just above the shielding gas 16 supplied to the processing point 8. The high-speed air supply nozzle 3 supplies the high-speed air 15 in a band shape within a range of 80 mm to 200 mm above the processing point 8 or less than half of the working distance WD, wherein the working distance WD is the distance between the irradiation surface of the laser 6 of the welding head 1 and the processing point 8.

[0069] Thus, even in the case of remote welding where the distance between the welding head and the processing point is long, the shielding gas 16 supplied from the shielding gas supply nozzle 4 can be used to prevent oxidation of the welding object 5. The high-speed air 15 supplied from the high-speed air supply nozzle 3 flowing directly above the shielding gas 16 can be used to remove the fume 7 and spatters that rise from the processing point 8 via the shielding gas 16. Furthermore, the refraction of the laser light 6 or the change in the focal position due to the fume 7 and spatters can be suppressed, and a good weld bead can be obtained in which oxidation of the processing point 8 of the welding object 5 is suppressed.

[0070] In addition, the high-speed air 15 flowing just above the shielding gas 16 can suppress the attachment of smoke and spatter to the irradiation surface of the laser 6 of the welding head 1, which is irradiated with the laser 6 from the welding head 1. The high-speed air 15 flowing just above the shielding gas 16 removes the smoke 7 and spatter, etc., which rise from the processing point 8 through the shielding gas 16. Therefore, the amount of shielding gas 16 used can be greatly reduced. Therefore, oxidation of the welding object 5 can be prevented by supplying a small amount of shielding gas 16. Therefore, good welding can be performed.

[0071] The shape of the nozzle opening of the high-speed air supply nozzle 3 may be a belt shape that is long in the irradiation direction of the laser beam 6 from the welding head 1 to the processing point 8 and is composed of multiple layers or a single layer.

[0072] In addition, the laser welding device of the present embodiment may also include an angle adjustment unit 19 capable of adjusting the ejection angle of the high-speed air supply nozzle 3 and the shielding gas supply nozzle 4. Preferably, the angle adjustment unit 19 is used to set the relative angle between the high-speed air supply nozzle 3 and the shielding gas supply nozzle 4 to be greater than 20 degrees and less than 70 degrees.

[0073] The laser welding device of this embodiment may further include a nozzle height adjustment unit 9 for mounting the shielding gas supply nozzle 4 and the high-speed air supply nozzle 3 and for adjusting the height of the shielding gas supply nozzle 4 relative to the processing point 8 .

[0074] In addition, the protective gas supply nozzle 4 is preferably constructed to be cylindrical in shape and to have a mesh-like mesh with a plurality of opening holes at the outlet for ejecting the protective gas 16, and is made of a material having a laser reflectivity higher than 80% for the laser 6 with a wavelength of greater than 900nm and less than 1100nm.

[0075] Furthermore, the laser welding device according to the present embodiment may include an angle adjusting unit 19 in the welding head 1 .

[0076] Furthermore, the laser welding device according to the present embodiment may include a nozzle height adjustment unit 9 in the welding head 1 .

[0077] Furthermore, the laser welding device of the present embodiment may include the angle adjusting portion 19 on the welding jig 18 .

[0078] Furthermore, the laser welding device of the present embodiment may include the nozzle height adjusting unit 9 in the welding jig 18 .

[0079] In addition, the laser welding device of the present embodiment may also include a low-speed air supply nozzle 2, which supplies low-speed air 14 in the same direction as the supply direction of high-speed air 15 from the high-speed air supply nozzle 3, directly below the welding head 1, in a manner that does not interfere with the supply of shielding gas 16 from the shielding gas supply nozzle 4. The shielding gas supply nozzle 4, the high-speed air supply nozzle 3, and the low-speed air supply nozzle 2 mounted on the welding head 1 are preferably configured to rotate relative to the optical axis of the laser 6 according to the welding direction 13.

[0080] In addition, the laser welding method of the present embodiment supplies high-speed air 15 in a band shape in the following laser welding device, which includes: a welding head 1, which irradiates the laser 6 to the processing point 8; a shielding gas supply nozzle 4, which supplies the shielding gas 16 to the processing point 8; and a high-speed air supply nozzle 3, which supplies high-speed air 15 with a flow rate greater than the supply flow rate of the shielding gas 16 between the shielding gas supply nozzle 4 and the welding head 1, in a horizontal direction or in a direction substantially orthogonal to the irradiation direction 20 of the laser 6 directly above the shielding gas 16 supplied to the processing point 8, and the high-speed air supply nozzle 3 is located above the processing point 8. The range is more than 80 mm and less than 200 mm or less than half of the working distance WD, wherein the working distance WD is the distance between the irradiation surface of the laser 6 of the welding head 1 and the processing point 8.

[0081] Industrial Applicability

[0082] According to the present invention, a good welding state can be achieved with a small amount of shielding gas, and the present invention is industrially useful as a laser welding device.

Claims

1. A laser welding device, comprising: A welding head that irradiates a laser beam toward a processing point of an object to be welded; a shielding gas supply nozzle for supplying shielding gas to the processing point; and a first air supply nozzle, which is between the shielding gas supply nozzle and the welding head, and supplies first air having a flow rate greater than the supply flow rate of the shielding gas, in a horizontal direction or in a direction substantially orthogonal to the irradiation direction of the laser, directly above the shielding gas supplied to the processing point, and the first air supply nozzle is arranged at a rear position in the supply direction of the first air relative to the optical axis of the laser, The first air supply nozzle is located within a range of 80 mm to 200 mm above the processing point, or within a range of less than half of the working distance between the irradiation surface of the laser of the welding head and the processing point, and supplies the first air in a band shape. The shape of the nozzle of the first air supply nozzle is a strip-like shape that is longer than the horizontal direction or the direction substantially perpendicular to the irradiation direction in the irradiation direction of the laser from the welding head to the processing point and is composed of multiple layers or a single layer. The supply flow rate of the protective gas is 10 L / min or more and 40 L / min or less.

2. The laser welding device according to claim 1, wherein: The laser welding device further includes an angle adjustment unit capable of adjusting the spray angles of the first air supply nozzle and the shielding gas supply nozzle. The angle adjustment unit sets a relative angle between the first air supply nozzle and the shielding gas supply nozzle to be greater than or equal to 20 degrees and less than or equal to 70 degrees.

3. The laser welding device according to claim 1 or 2, wherein: The shielding gas supply nozzle is cylindrical in shape and has a mesh at a nozzle for ejecting the shielding gas. The shielding gas supply nozzle is made of a material having a laser reflectivity higher than 80% for laser light with a wavelength of 900 nm to 1100 nm.

4. The laser welding device according to claim 1 or 2, wherein: The laser welding device further includes a nozzle height adjustment unit for mounting the shielding gas supply nozzle and the first air supply nozzle and capable of adjusting a height of the shielding gas supply nozzle relative to the processing point.

5. The laser welding device according to claim 1 or 2, wherein: The laser welding device further includes a second air supply nozzle, which supplies second air in the same direction as the supply direction of the first air from the first air supply nozzle directly below the welding head in a manner that does not interfere with the supply of the shielding gas from the shielding gas supply nozzle, so as to suppress the attachment of smoke and spatter to the shielding glass provided on the surface of the welding head irradiated with the laser, and the flow rate of the second air is less than the supply flow rate of the first air. The first air supply nozzle is arranged between the second air supply nozzle and the shielding gas supply nozzle.

6. A laser welding method, wherein a first air is supplied in a band shape in a laser welding device, wherein: The laser welding device comprises: A welding head that irradiates a laser beam toward a processing point of an object to be welded; a shielding gas supply nozzle for supplying shielding gas to the processing point; and a first air supply nozzle, which is between the shielding gas supply nozzle and the welding head, and supplies the first air having a flow rate greater than the supply flow rate of the shielding gas, directly above the shielding gas supplied to the processing point in a horizontal direction or in a direction substantially perpendicular to the irradiation direction of the laser, and the first air supply nozzle is arranged at a rear position in the supply direction of the first air relative to the optical axis of the laser, The first air supply nozzle is located within a range of 80 mm to 200 mm above the processing point, or within a range of less than half of the working distance between the irradiation surface of the laser of the welding head and the processing point. The shape of the nozzle of the first air supply nozzle is a strip-like shape that is longer than the horizontal direction or the direction substantially perpendicular to the irradiation direction in the irradiation direction of the laser from the welding head to the processing point and is composed of multiple layers or a single layer. The supply flow rate of the protective gas is greater than or equal to 10 L / min and less than or equal to 40 L / min.

7. The laser welding method according to claim 6, wherein: A relative angle between the first air supply nozzle and the shielding gas supply nozzle is greater than or equal to 20 degrees and less than or equal to 70 degrees.

8. The laser welding method according to claim 7, wherein: An angle adjustment unit capable of adjusting the spray angles of the first air supply nozzle and the shielding gas supply nozzle is further provided.

9. The laser welding method according to claim 6, wherein: A nozzle height adjustment unit is also provided, which is used to assemble the protective gas supply nozzle and the first air supply nozzle and can adjust the height of the protective gas supply nozzle relative to the processing point.

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