Shield gas supply device and shield gas supply method

Abstract

The present invention supplies a shield gas appropriately. This shield gas supply device, which supplies a shield gas to a region where a processing surface is irradiated from above in the vertical direction with a laser beam, comprises: a first nozzle that is disposed on one side of the processing surface and that, from an opening, sprays a first shield gas, which is an inert gas, in a first direction which is from said one side of the processing surface toward another side; and a second nozzle that is disposed on said other side of the processing surface and that, from an opening, sprays a second shield gas, which is an inert gas, in a second direction which is from said other side of the processing surface to said one side, wherein the first nozzle and the second nozzle are positioned away from the central axis of the laser beam, and the opening of the first nozzle and the opening of the second nozzle face each other.

Description

Shielding gas supply device and shielding gas supply method

[0001] The present disclosure relates to a shielding gas supply device and a shielding gas supply method.

[0002] There is known a technique for processing an irradiated portion by irradiating a laser beam. Examples of processing using a laser include welding, cutting, drilling, etc. For example, in a laser welding device disclosed in Patent Document 1, when a laser beam is irradiated to weld a workpiece, a gas is sprayed onto the welded portion to prevent oxidation.

[0003] Japanese Utility Model Application Laid-Open Publication No. 3-51987

[0004] In the technology of Patent Document 1, the nozzle covers the weld zone of the workpiece, making it difficult to check the weld zone during processing. The gap between the workpiece and the nozzle is narrow, and radiant heat during welding may affect the nozzle. Therefore, there is a need to appropriately supply shielding gas to cover the molten zone.

[0005] The present disclosure is intended to solve the above-mentioned problems, and aims to provide a shielding gas supply device and a shielding gas supply method that can appropriately supply shielding gas.

[0006] In order to solve the above-mentioned problems and achieve the object, the shielding gas supply device according to the present disclosure is a shielding gas supply device that supplies shielding gas to an area where a laser beam is irradiated from above in the vertical direction onto a processing surface, and includes: a first nozzle that is arranged on one side of the processing surface and that sprays a first shielding gas, which is an inert gas, from an opening in a first direction from one side of the processing surface to the other side; and a second nozzle that is arranged on the other side of the processing surface and that sprays a second shielding gas, which is an inert gas, from an opening in a second direction from the other side of the processing surface to the one side, wherein the first nozzle and the second nozzle are positioned away from the central axis of the laser beam, and the opening of the first nozzle and the opening of the second nozzle face each other.

[0007] In order to solve the above-mentioned problems and achieve the object, the shielding gas supply method according to the present disclosure is a shielding gas supply method for supplying a shielding gas to an area where a laser beam is irradiated from above in a vertical direction onto a processing surface, and includes a step of spraying a first shielding gas, which is an inert gas, from an opening in a first direction from one side of the processing surface to the other side, and a step of spraying a second shielding gas, which is an inert gas, from an opening in a second direction from the other side of the processing surface to one side.

[0008] According to the present disclosure, shielding gas can be supplied appropriately.

[0009] FIG. 1 is a perspective view showing a processing apparatus having a shielding gas supply apparatus according to a first embodiment. FIG. 2 is a plan view showing the shielding gas supply apparatus according to the first embodiment. FIG. 3 is a front view showing the shielding gas supply apparatus according to the first embodiment. FIG. 4 is a view explaining the position of the shielding gas supply nozzle according to the first embodiment. FIG. 5 is a schematic view explaining the supply of shielding gas according to the first embodiment. FIG. 6 is a front view showing another example of the shielding gas supply apparatus according to the first embodiment. FIG. 7 is a schematic view showing a flow straightening mechanism of the shielding gas supply apparatus according to the second embodiment. FIG. 8 is a view explaining the shielding gas supply apparatus according to the third embodiment. FIG. 9 is a view explaining the shielding gas supply apparatus according to the fourth embodiment. FIG. 10 is a view explaining the shielding gas supply apparatus according to the fourth embodiment. FIG. 11 is a front view showing the shielding gas supply apparatus according to the fourth embodiment. FIG. 12 is a view explaining the opening of a first nozzle. FIG. 13 is a view explaining the opening of a second nozzle. FIG. 14 is a view explaining another example of the shielding gas supply apparatus according to the fourth embodiment. FIG. 15 is a view explaining another example of the shielding gas supply apparatus according to the fourth embodiment.

[0010] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments, and when there are multiple embodiments, the present invention also includes combinations of the embodiments.

[0011] First Embodiment Shielding Gas Supply Device FIG. 1 is a perspective view showing a processing apparatus having a shielding gas supply device according to a first embodiment. The processing apparatus 1 of this embodiment is applied to, for example, a three-dimensional (3D) lamination apparatus that forms a three-dimensional laminate using a molten material 26 as a raw material. One additive manufacturing method using a three-dimensional (3D) lamination apparatus is an arc welding method, in which a molten wire is supplied to a target processing surface and irradiated with a laser beam, electron beam, or the like to melt the supplied wire. During this process, the processing apparatus 1 supplies an inert gas along the smooth surface of the molten material 26 to prevent oxygen from contacting the processing surface 102 and oxygen-induced oxidation of the processing surface 102. However, the processing apparatus 1 of this embodiment is not limited to three-dimensional (3D) lamination apparatuses, and can also be applied to other processing apparatuses (e.g., arc welding apparatuses) that perform various processes using a laser beam or the like. While this embodiment will be described using an arc welding three-dimensional lamination apparatus as an example, a three-dimensional lamination apparatus that sprays metal powder onto the processing surface may also be used. The processing device 1 can be more effective when used for welding as processing, but it may also be used for processing in which a laser is irradiated to cut or drill a hole at an irradiated position on the processing surface.

[0012] As shown in FIG. 1 , the processing apparatus 1 includes an irradiation unit 10, a molten material supply unit 20, and a shielding gas supply unit 30. The processing apparatus 1 supplies a molten material 26 from the molten material supply unit 20 to an irradiation position 104 on a processing surface 102, irradiates the processing surface 102 with a laser from the irradiation unit 10, and supplies a shielding gas from the shielding gas supply unit 30, thereby welding the processing surface 102 with the molten material 26. In this embodiment, the processing surface 102 is an elongated plane having a longitudinal direction along one horizontal direction and a transverse direction perpendicular to the longitudinal direction. Note that, although the processing apparatus 1 of this embodiment is an example in which welding is performed by supplying a molten material from the molten material supply unit 20, welding may also be performed by melting the processing surface 102 with a laser without providing the molten material supply unit 20.

[0013] In the following description, the horizontal direction is referred to as the X direction, the direction perpendicular to the X direction is referred to as the Y direction, and the vertical direction perpendicular to the X and Y directions is referred to as the Z direction. One of the X directions is referred to as the X1 direction, and the direction opposite to the X1 direction is referred to as the X2 direction. One of the Y directions is referred to as the Y1 direction, and the direction opposite to the Y1 direction is referred to as the Y2 direction. The Y1 direction is referred to as the movement direction as appropriate. The movement direction is the direction in which the processing device 1 moves relative to the processing surface 102. That is, in this embodiment, the processing device 1 processes the processing surface 102 while proceeding in the Y1 direction. Alternatively, the processing device 1 may be fixed, the processing surface 102 may be moved, and the processing device 1 may move in the Y1 direction relative to the processing surface 102.

[0014] (Irradiation unit) The irradiation unit 10 irradiates the processing surface 102 with a laser beam L from above in the vertical direction. The irradiation unit 10 is disposed at an angle with respect to the processing surface 102. The irradiation unit 10 may be, for example, in the form of a nozzle capable of irradiating the laser beam L. A melted portion 106 is formed at an irradiation position 104 on the processing surface 102 where the laser beam L is irradiated. The melted portion 106 is a surface of the processing surface 102 that has been melted by the heat generated by irradiation with the laser beam L. The heat of the laser beam L accumulates in the melted portion 106, which dissipates and solidifies over time.

[0015] (Melted Material Supply Unit) The melted material supply unit 20 supplies wire, which is the melt 26, to the processing surface 102. The melted material supply unit 20 is arranged so as to supply the wire from above in the vertical direction. The melted material supply unit 20 is arranged at an angle with respect to the processing surface 102. The melted material supply unit 20 is arranged at an angle so as not to be coaxial with the irradiation unit 10. The melted material supply unit 20 is, for example, a nozzle capable of supplying wire. The melted material supply unit 20 receives wire from a wire supply source, and the wire passes through the main body 22 and is exposed from the tip 24. The melted material supply unit 20 supplies the exposed wire to the irradiation position 104 where the laser beam L is irradiated. The wire may be a filler wire or a solid wire. In this embodiment, there is one melted material supply unit 20, but multiple melted material supply units 20 may be arranged. The melted material supply unit 20 may be a nozzle that sprays metal powder onto the processing surface 102.

[0016] (Shielding gas supply device) Fig. 2 is a plan view showing the shielding gas supply device according to the first embodiment, Fig. 3 is a front view showing the shielding gas supply device according to the first embodiment, and Fig. 4 is a view explaining the position of the shielding gas supply nozzle according to the first embodiment.

[0017] The shielding gas supply device 30 includes a first nozzle 40 and a second nozzle 50. The first nozzle 40 and the second nozzle 50 of the shielding gas supply device 30 are connected to a shielding gas supply unit that supplies the shielding gas, and the shielding gas is supplied. The shielding gas supply device 30 sprays the shielding gas from the tips of the first nozzle 40 and the second nozzle 50. In this embodiment, the shielding gases G1 and G2 are inert gases. The inert gas is nitrogen gas (N ２ ) or rare gases such as argon gas (Ar) and helium gas (He) are used.

[0018] The shielding gas supply device 30 has a first nozzle 40 and a second nozzle 50 arranged on both sides of the machining surface 102 in the X direction, and supplies shielding gas to the machining surface 102 from the first nozzle 40 and the second nozzle 50. The shielding gas supply device 30 is arranged along the Y direction. The shielding gas supply device 30 receives shielding gases G1 and G2 from a supply source and supplies the shielding gases G1 and G2 to the machining surface 102. The shielding gas supply device 30 ejects the shielding gases G1 and G2 from the first nozzle 40 and the second nozzle 50 onto the machining surface 102 in a direction intersecting the machining surface 102. In other words, the direction in which the shielding gases G1 and G2 are ejected by the shielding gas supply device 30 is a direction intersecting the machining surface 102.

[0019] (First Nozzle) The first nozzle 40 has a base 41 and a tip 42. The bottom surface 46 of the first nozzle 40 is located vertically below the machining surface 102. One end of the base 41 is connected to a shielding gas supply source, and the other end is connected to the tip 42. The base 41 is hollow, and a first flow path C11 is formed along the Y direction. One end of the tip 42 is connected to the end of the base 41 in the Y direction.

[0020] One end of the tip portion 42 is connected to the base portion 41, and the end not connected to the base portion 41 forms an opening 43. The tip portion 42 is hollow, and a second flow path C12 is formed that extends from the Y direction to the X direction. The tip portion 42 is inclined toward the movement direction with respect to the first direction. As the tip portion 42 extends from the base portion 41 toward the opening 43, the tip portion 42 faces the first direction and is inclined toward the movement direction. The first shielding gas G1 flows from the base portion 41 through the tip portion 42, and is ejected from the opening 43 toward the machining surface 102.

[0021] The tip portion 42 has a first side surface 42a on the movement direction side, a second side surface 42b on the opposite side to the movement direction, a first curved surface 42c, and a second curved surface 42d. The tip portion 42 is connected to the base portion 41 via the first curved surface 42c and the second curved surface 42d. The first side surface 42a and the second side surface 42b are inclined toward the movement direction with respect to the first direction. The first curved surface 42c is formed on the movement direction side and curves to protrude in the horizontal direction (X2 direction). The second curved surface 42d is formed on the opposite side to the movement direction and curves to protrude in the horizontal direction (X2 direction). The first curved surface 42c is formed more gently than the second curved surface 42d. The first curved surface 42c is connected to the side surface of the base portion 41 on the X2 direction side. The second curved surface 42d is formed to be steeper than the first curved surface 42c. The second curved surface 42d is connected to the side surface of the base 41 on the X1 direction side. That is, as shown in FIG. 4 , the first side surface 42a and the second side surface 42b, when viewed vertically, form an angle θ1 between the first side surface 42a and the first direction, and an angle θ2 between the second side surface 42b and the first direction. The angle θ1 is larger than the angle θ2. That is, the angle θ2 is closer to the X direction than the angle θ1, in other words, closer to perpendicular when viewed vertically. The angles θ1 and θ2 may be any angles as long as the angle θ1 is larger than the angle θ2. However, in this embodiment, the angle θ1 is 45 degrees and the angle θ2 is 30 degrees. The first curved surface 42c and the second curved surface 42d do not necessarily have to be formed. The angle θ1 is preferably 30°≦θ1≦60°. The angle θ2 is preferably 0°<θ2≦30°. In the example shown in FIG. 4, the relationship between θ1 and θ2 is θ1>θ2, and preferably 0°≦θ1−θ2≦45°, and more preferably 10°≦θ1−θ2≦20°.

[0022] The opening 43 faces the processing surface 102. The opening 43 is parallel to the Y direction. The opening 43 is not limited to being parallel to the Y direction, and may be inclined toward the processing surface 102 in the X direction.

[0023] The first nozzle 40 allows the first shielding gas G1 to flow from the base 41 to the tip 42. The first nozzle 40 is disposed on one side of the machining surface 102 (at a position closer to the X2 direction than the machining surface 102) and ejects the first shielding gas G1 from an opening 43 in a first direction (X1 direction) from one side of the machining surface 102 to the other side. The base 41 of the first nozzle 40 extends in the Y direction. The tip 42 of the first nozzle 40 is spaced from the central axis of the laser beam L in the X2 direction. The first nozzle 40 ejects the first shielding gas G1 in a direction inclined relative to the movement direction with respect to the first direction. That is, the first nozzle 40 ejects the first shielding gas G1 from one side of the machining surface 102 toward the machining surface 102 in a direction inclined relative to both the movement direction and the direction perpendicular to the movement direction.

[0024] (Second Nozzle) The second nozzle 50 has a base 51 and a tip 52. The bottom surface 56 of the second nozzle 50 is located vertically below the machining surface 102. One end of the base 51 is connected to a shielding gas supply source, and the other end is connected to the tip 52. The base 51 is hollow, and a first flow path C21 is formed along the Y direction. One end of the tip 52 is connected to the end of the base 51 in the Y direction.

[0025] One end of the tip portion 52 is connected to the base portion 51, and the end not connected to the base portion 51 forms an opening 53. The tip portion 52 is hollow, and a second flow path C22 is formed in the tip portion 52, extending from the Y direction to the X direction. The tip portion 52 is inclined toward the movement direction with respect to the second direction. As the tip portion 52 extends from the base portion 51 toward the opening 53, the tip portion 52 faces the second direction and is inclined toward the movement direction. The second shielding gas G2 flows from the base portion 51 through the tip portion 52, and is ejected from the opening 53 toward the machining surface 102.

[0026] The tip portion 52 has a first side surface 52a on the movement direction side, a second side surface 52b on the opposite side to the movement direction, a first curved surface 52c, and a second curved surface 52d. The tip portion 52 is connected to the base portion 51 via the first curved surface 52c and the second curved surface 52d. The first side surface 52a and the second side surface 52b are inclined toward the movement direction with respect to the second direction. The first curved surface 52c is formed on the movement direction side and curved to protrude in the horizontal direction (X1 direction). The second curved surface 52d is formed on the opposite side to the movement direction and curved to protrude in the horizontal direction (X1 direction). The first curved surface 52c is formed more gently than the second curved surface 52d. The first curved surface 52c is connected to the side surface of the base portion 51 on the X1 direction side. The second curved surface 52d is formed to be steeper than the first curved surface 52c. The second curved surface 52d is connected to the side surface of the base 51 on the X2 direction side. That is, as shown in FIG. 4 , the first side surface 52a and the second side surface 52b, when viewed vertically, form an angle θ1 between the first side surface 52a and the second direction, and an angle θ2 between the second side surface 52b and the second direction. The angle θ1 is larger than the angle θ2. That is, the angle θ2 is formed so as to be more in line with the X direction than the angle θ1, in other words, closer to perpendicular when viewed vertically. The angles θ1 and θ2 may be any values ​​as long as the angle θ1 is larger than the angle θ2. However, in this embodiment, the angle θ1 is 45 degrees and the angle θ2 is 30 degrees. The first curved surface 52c and the second curved surface 52d do not necessarily have to be formed. The angle θ1 is preferably 30°≦θ1≦60°. The angle θ2 is preferably 0°<θ2≦30°. In the example shown in FIG. 4, the relationship between θ1 and θ2 is θ1>θ2, and preferably 0°≦θ1−θ2≦45°, and more preferably 10°≦θ1−θ2≦20°.

[0027] The opening 53 faces the processing surface 102. The opening 53 is parallel to the Y direction. The opening 53 is not limited to being parallel to the Y direction, and may be inclined toward the processing surface 102 in the X direction.

[0028] The second nozzle 50 allows the second shielding gas G2 to flow from the base 51 to the tip 52. The second nozzle 50 is disposed on the other side of the machining surface 102 (at a position closer to the X1 direction than the machining surface 102) and sprays the second shielding gas G2 from the opening 53 in a second direction (X2 direction) from the other side of the machining surface 102 to one side of the machining surface 102. The base 41 of the second nozzle 50 extends in the Y direction. The tip 52 of the second nozzle 50 is spaced apart from the central axis of the laser beam L in the X1 direction. The second nozzle 50 sprays the second shielding gas G2 in a direction inclined relative to the second direction and relative to the movement direction. That is, the second nozzle 50 sprays the second shielding gas G2 from the other side of the machining surface 102 toward the machining surface 102 in a direction inclined relative to both the movement direction and the direction perpendicular to the movement direction.

[0029] (Position of the First Nozzle and the Second Nozzle) The first nozzle 40 and the second nozzle 50 are spaced apart from the center axis of the laser beam L in different directions in the X direction, and the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are positioned opposite each other. The end point 42p of the first nozzle 40 and the end point 52p of the second nozzle 50 are shifted from the processing point P in the Y1 direction by a predetermined distance d. The predetermined distance d is preferably shorter than the distance to the center of the opening 43 and the opening 53 in the movement direction. In other words, the irradiation position 104 of the laser beam L on the processing surface 102 can be said to be located closer to the movement direction than the center point between the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50. This allows the molten zone 106 to be covered by the first shielding gas G1 and the second shielding gas G2. The predetermined distance d may be any value, but is 10 mm in this embodiment. Furthermore, in this embodiment, the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are located at the same position in the Y direction, but it is sufficient if the openings 43 and 53 partially overlap. That is, the openings 43 and 53 may be positioned offset in the Y direction. Even in this case, the openings 43 and 53 are positioned offset so that the molten zone 106 can be covered with the shielding gases G1 and G2. Furthermore, the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are rectangular, but may also be polygonal. Furthermore, the openings 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 do not have to have the same shape and may have different shapes.

[0030] <Shielding Gas Supply> FIG. 5 is a schematic diagram illustrating the supply of shielding gas according to the first embodiment. The irradiation unit 10 is positioned vertically above and toward the Y1 direction from the center point of the first nozzle 40 and the second nozzle 50, and irradiates the laser beam L onto the processing surface 102. The melt supply unit 20 supplies the melt 26 to the irradiation position 104. The melt 26 is melted by the laser beam L, and the molten material 26 solidifies. That is, the irradiation unit 10 irradiates the laser beam L onto the processing surface 102 at the position where the melt 26 is supplied. If a shielding gas is not supplied, the melt 26 will come into contact with oxygen in the air, resulting in oxidation of the processed object 100. In this embodiment, as shown in FIGS. 4 and 5 , the direction of ejection of the first shielding gas G1 from the first nozzle 40 and the direction of ejection of the second shielding gas G2 from the second nozzle 50 are opposite each other. The first shielding gas G1 ejected from the first nozzle 40 and the second shielding gas G2 ejected from the second nozzle 50 collide. The first shielding gas G1 ejected from the first nozzle 40 and the second shielding gas G2 ejected from the second nozzle 50 collide obliquely toward the direction of movement. When the first shielding gas G1 and the second shielding gas G2 collide, pressure is generated. After the collision, the first shielding gas G1 and the second shielding gas G2 flow from the one with the higher generated pressure to the one with the lower generated pressure. In the example shown in FIG. 4 , after the collision, the first shielding gas G1 and the second shielding gas G2 flow in the Y direction.

[0031] When the shielding gases G1 and G2 are ejected, boundaries B11, B12, B21 and B22 between the air and the shielding gases G1 and G2 are formed.

[0032] The boundaries B11 and B12 are formed when the first shielding gas G1 is ejected. The boundaries B11 and B12 are boundaries between the first shielding gas G1 and air. The boundary B11 is formed on the movement direction side of the opening 43. The boundary B12 is formed on the opposite side to the movement direction of the opening 43. The first shielding gas G1 near the boundaries B11 and B12 mixes with oxygen in the air.

[0033] The boundaries B21 and B22 are formed when the second shielding gas G2 is ejected. The boundaries B21 and B22 are boundaries between the second shielding gas G2 and air. The boundary B21 is formed on the movement direction side of the opening 53. The boundary B22 is formed on the opposite side to the movement direction of the opening 53. The second shielding gas G2 near the boundaries B21 and B22 mixes with oxygen in the air.

[0034] The first shielding gas G1 that collides with the second shielding gas G2 (the first shielding gas G1 after collision) flows toward the direction of movement, but a portion of it flows in the opposite direction to the direction of movement. Specifically, a portion of the first shielding gas G1 after collision near the boundary surface B12 flows in the opposite direction to the direction of movement. The amount of the first shielding gas G1 after collision flowing in the opposite direction to the direction of movement is less than the amount of the first shielding gas G1 after collision flowing toward the direction of movement. The first shielding gas G1 after collision near the boundary surface B11 flows toward the direction of movement because the first shielding gas G1 on the opposite side to the direction of movement also flows toward the direction of movement. In the example shown in FIG. 4 , the first shielding gas G1 after collision flows in the direction of arrow A1, but a portion of the first shielding gas G1 after collision near the boundary surface B12 flows in the direction of arrow B1. The first shielding gas G1 after collision near the boundary surface B11 flows toward the direction of movement because the first shielding gas G1 on the opposite side to the direction of movement flows in the direction of arrow A11.

[0035] The second shielding gas G2 that collides with the first shielding gas G1 (the second shielding gas G2 after collision) flows toward the direction of movement, but a portion of it flows in the opposite direction to the direction of movement. Specifically, a portion of the second shielding gas G2 after collision near the boundary surface B22 flows in the opposite direction to the direction of movement. The amount of the second shielding gas G2 after collision flowing in the opposite direction to the direction of movement is less than the amount of the second shielding gas G2 after collision flowing toward the direction of movement. The second shielding gas G2 after collision near the boundary surface B21 flows toward the direction of movement because the second shielding gas G2 on the opposite side to the direction of movement also flows toward the direction of movement. In the example shown in FIG. 4 , the second shielding gas G2 after collision flows in the direction of arrow A2, but a portion of the second shielding gas G2 after collision near the boundary surface B22 flows in the direction of arrow B2. The second shielding gas G2 after collision near the boundary surface B21 flows toward the direction of movement because the second shielding gas G2 on the opposite side to the direction of movement flows in the direction of arrow A22.

[0036] As described above, the shielding gases G1 and G2 after the collision flow downstream, so they can be controlled in one direction. That is, the flow of the shielding gases G1 and G2 after the collision is stabilized. This allows the shielding gases G1 and G2 to widely cover the molten zone 106, and prevents the gas shield supply nozzle from becoming too large.

[0037] <Another Example of First Embodiment> FIG. 6 is a front view showing another example of a shielding gas supply device according to the first embodiment.

[0038] In another example of the first embodiment, as shown in FIG. 6 , the shielding gas supply device 30 is disposed vertically above the machining surface 102. The configuration of the shielding gas supply device 30 is similar to that of the first embodiment. That is, the first nozzle 40 and the second nozzle 50 are disposed vertically above the machining surface 102, and the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are inclined vertically downward. This allows the shielding gas supply device 30 to eject the first shielding gas G1 and the second shielding gas G2 onto the machining surface 102. Furthermore, the shielding gas supply device 30 can supply inert gas even to a machining surface that is wider than the distance between the first nozzle 40 and the second nozzle 50.

[0039] Effects of the First Embodiment The processing apparatus 1 according to the first embodiment includes an irradiation unit 10, a molten material supply unit 20, a first nozzle 40, and a second nozzle 50. The first nozzle 40 and the second nozzle 50 extend at an angle, and the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are arranged opposite each other. The inert gas is ejected from the side by the first nozzle 40 and the second nozzle 50 and flows in the direction of movement after collision, thereby suppressing oxidation of the molten zone. In other words, the shielding gas can be appropriately supplied. Furthermore, there is no need to cover the processing surface with the nozzle supplying the shielding gas, and a mechanism for cooling the nozzle is also unnecessary. In other words, the first nozzle 40 and the second nozzle 50 can be simplified. In other words, the first nozzle 40 and the second nozzle 50 can be prevented from becoming large. Furthermore, by arranging the first nozzle 40 and the second nozzle 50 in this manner, the state of the processing surface 102 can be monitored.

[0040] Second Embodiment Next, a second embodiment will be described. FIG. 7 is a schematic diagram showing a flow straightening mechanism of a shielding gas supply device according to the second embodiment. The processing apparatus 1 differs from the first embodiment in that a flow straightening mechanism is provided. The same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted. Note that while FIG. 7 shows an example in which the flow straightening mechanism 60 is provided in the first nozzle 40, in reality, the flow straightening mechanism 60 is also provided in the second nozzle 50, and rectifies the flow of the second shielding gas G2 as well. In other words, the first nozzle 40 and the second nozzle 50 are provided with the flow straightening mechanism 60 that rectifies the flow of the inert gas.

[0041] The flow straightening mechanism 60 straightens the flow of the inert gas flowing through the first nozzle 40 and the second nozzle 50. The flow straightening mechanism 60 is provided inside the first nozzle 40 and at the opening 43 of the first nozzle 40. The flow straightening mechanism 60 may be provided either inside the first nozzle 40 or at the opening 43. In this embodiment, as shown in Fig. 7 , the flow straightening mechanism 60 is provided at the opening 43. The flow straightening mechanism 60 is, for example, a member having a wire mesh or honeycomb structure.

[0042] By providing the first nozzle 40 and the second nozzle 50 with the flow straightening mechanism 60, the flow of the shielding gas near the boundary surface can be straightened.

[0043] In the above-described embodiment, the processing device 1 performs processing from the Y2 direction toward the Y1 direction, but processing may also be performed from the Y1 direction toward the Y2 direction. In this case, the processing device 1 is reversed so that the Y2 direction becomes the movement direction.

[0044] Furthermore, when machining is performed from the Y1 direction to the Y2 direction, the tip of the machining device 1 may be oriented in the Y1 direction, as in the above embodiment. In this case, the shielding gas supply device 30 is displaced in the Y1 direction. For example, the shielding gas supply device 30 may be displaced so that the irradiation position 104 of the laser beam L on the machining surface 102 is located on the Y2 side of the center point between the openings 43 and 53. By displacing the tip of the shielding gas supply device 30 in the Y2 direction in this way, the molten part immediately after machining can be covered with shielding gas, making it possible to suppress oxidation of the machining surface.

[0045] <Third Embodiment> Next, a third embodiment will be described. Fig. 8 is a diagram for explaining a shielding gas supply device according to the third embodiment. The processing device 1A differs from the first embodiment in that the shape of the tip portion is different. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0046] (First nozzle) One end of the tip portion 42A is connected to the base portion 41, and the end not connected to the base portion 41 forms an opening 43. The tip portion 42A is hollow, and a second flow path C12 is formed that runs from the Y direction to the X direction. The tip portion 42A is inclined toward the movement direction with respect to the first direction. As the tip portion 42A moves from the base portion 41 toward the opening 43, the tip portion 42A moves toward the first direction and is inclined toward the movement direction. The first shielding gas G1 flows from the base portion 41 through the tip portion 42A, and is ejected from the opening 43 toward the machining surface 102.

[0047] The tip portion 42A has a first side surface 42a on the movement direction side, a second side surface 42b on the opposite side to the movement direction, and a first curved surface 42c. The tip portion 42A is connected to the base portion 41 via the second side surface 42b and the first curved surface 42c. The first side surface 42a is inclined toward the movement direction with respect to the first direction. The second side surface 42b is inclined in the opposite direction to the movement direction with respect to the first direction. The first curved surface 42c is formed on the movement direction side and curves to protrude in the horizontal direction (X2 direction). The first curved surface 42c is connected to the side surface of the base portion 41 on the X2 direction side.

[0048] (Second nozzle) One end of the tip portion 52A is connected to the base portion 51, and the end not connected to the base portion 51 forms an opening 53. The tip portion 52A is hollow, and a second flow path C22 is formed that runs from the Y direction to the X direction. The tip portion 52A is inclined toward the movement direction with respect to the second direction. As the tip portion 52A moves from the base portion 51 toward the opening 53, the tip portion 52A moves toward the second direction and is inclined toward the movement direction. The second shielding gas G2 flows from the base portion 51 through the tip portion 52A, and is ejected from the opening 53 toward the machining surface 102.

[0049] The tip portion 52 has a first side surface 52a on the A movement direction side, a second side surface 52b on the opposite side to the movement direction, and a first curved surface 52c. The tip portion 52A is connected to the base portion 51 via the second side surface 52b and the first curved surface 52c. The first side surface 52a is inclined toward the movement direction with respect to the second direction. The second side surface 52b is inclined in the opposite direction to the movement direction with respect to the second direction. The first curved surface 52c is formed on the movement direction side and curved so as to protrude in the horizontal direction (X1 direction). The first curved surface 52c is connected to the side surface of the base portion 51 on the X1 direction side.

[0050] <Supply of Shielding Gas> The first shielding gas G1 that collides with the second shielding gas G2 (first shielding gas G1 after collision) flows in the direction of movement and in the opposite direction to the direction of movement. For example, the first shielding gas G1 after collision flows from near the center of the opening 43 in the direction of movement and in the opposite direction to the direction of movement. In the example shown in Fig. 8 , the first shielding gas G1 after collision flows from near the center of the opening 43 in the directions of arrows A1 and a1 and arrows B1 and b1.

[0051] The second shielding gas G2 that collides with the first shielding gas G1 (the second shielding gas G2 after collision) flows in the direction of movement and in the opposite direction to the direction of movement. For example, the second shielding gas G2 after collision flows from near the center of the opening 53 in the direction of movement and in the opposite direction to the direction of movement. In the example shown in Fig. 8, the second shielding gas G2 after collision flows from near the center of the opening 53 in the directions of arrows A2 and a2 and arrows B2 and b2.

[0052] <Effects of the Third Embodiment> The machining apparatus 1A of the third embodiment can flow the shielding gas after collision in both the moving direction and the opposite direction to the moving direction. Therefore, a stable supply of shielding gas can be achieved even when machining is performed in the opposite direction to the moving direction. In other words, a stable supply of shielding gas can be achieved in the Y direction during machining.

[0053] Fourth Embodiment Next, a fourth embodiment will be described. FIGS. 9 and 10 are diagrams for explaining a shielding gas supply apparatus according to the fourth embodiment. FIG. 11 is a front view showing the shielding gas supply apparatus according to the fourth embodiment. FIG. 12 is a diagram explaining an opening of a first nozzle. FIG. 13 is a diagram explaining an opening of a second nozzle. The machining apparatus 1B differs from the first embodiment in that the first nozzle 40 and the second nozzle 50 are internally separated. Components similar to those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The shielding gas supply apparatus 30 of this embodiment includes a rectifying mechanism and a flow guide arranged corresponding to each of the first nozzle 40 and the second nozzle 50. The first nozzle 40 includes a first rectifying mechanism 60 and a first flow guide 70. The second nozzle 50 includes a second rectifying mechanism 60 and a second flow guide 80.

[0054] (Melt Supply Unit) The melt supply unit 20 supplies wire, which is the melt 26, to the processing surface 102. The melt supply unit 20 is arranged so as to supply the wire from above in the vertical direction. The melt supply unit 20 is arranged at an angle with respect to the processing surface 102. The melt supply unit 20 is arranged at an angle so as not to be coaxial with the irradiation unit 10. The melt supply unit 20 is, for example, a nozzle capable of supplying wire. The melt supply unit 20 receives wire from a wire supply source, and the wire passes through the main body 22 and is exposed from the tip 24. The melt supply unit 20 supplies the exposed wire to the irradiation position 104 where the laser beam L is irradiated. The wire may be a filler wire or a solid wire. In this embodiment, there are multiple melt supply units 20, but a single melt supply unit may also be used. The melt supply unit 20 may be a nozzle that sprays metal powder onto the processing surface 102.

[0055] 9 and 11 , the shielding gas supply device 30 is disposed vertically above the machining surface 102. That is, the first nozzle 40 and the second nozzle 50 are disposed vertically above the machining surface 102, and the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are inclined vertically downward. The bottom surface 46 of the first nozzle 40 and the bottom surface 56 of the second nozzle 50 are located vertically above the machining surface 102, and the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are inclined vertically downward.

[0056] (First Nozzle) The first nozzle 40 has a base 41 and a tip 42. The bottom surface 46 of the first nozzle 40 is located vertically above the machining surface 102. One end of the base 41 is connected to a shielding gas supply source, and the other end is connected to the tip 42. The base 41 is hollow, and a first flow path C11 is formed along the Y direction. One end of the tip 42 is connected to the end of the base 41 in the Y direction.

[0057] One end of the tip portion 42 is connected to the base portion 41, and the end not connected to the base portion 41 forms an opening 43. The tip portion 42 is hollow, and a second flow path C12 is formed that extends from the Y direction to the X direction. The tip portion 42 is inclined toward the movement direction with respect to the first direction. As the tip portion 42 extends from the base portion 41 toward the opening 43, the tip portion 42 faces the first direction and is inclined toward the movement direction. The first shielding gas G1 flows from the base portion 41 through the tip portion 42, and is ejected from the opening 43 toward the machining surface 102.

[0058] The tip portion 42 has a first side surface 42a on the movement direction side, a first curved surface 42c, and a second curved surface 42d. The tip portion 42 is connected to the base portion 41 via the first curved surface 42c and the second curved surface 42d. The first side surface 42a is inclined toward the movement direction with respect to the first direction. The first curved surface 42c is formed on the movement direction side and curves to protrude in the horizontal direction (X2 direction). The second curved surface 42d is formed on the opposite side to the movement direction and curves to protrude in the horizontal direction (X2 direction). The first curved surface 42c is formed more gently than the second curved surface 42d. The first curved surface 42c is connected to the side surface of the base portion 41 on the X2 direction side. The second curved surface 42d is formed steeper than the first curved surface 42c. The second curved surface 42d forms the side surface of the base portion 41 on the X1 direction side. The tip portion 42 may have a second side surface 42b.

[0059] 9, the opening 43 faces the processing surface 102. The opening 43 is parallel to the Y direction. The opening 43 is inclined toward the processing surface 102 in the X direction.

[0060] 12, the opening 43 is divided. In this embodiment, the opening 43 is provided with a first flow rectification mechanism 60.

[0061] The first rectifying mechanism 60 is disposed in the opening 43 and rectifies the flow of the first shielding gas G1. The first rectifying mechanism 60 divides the first shielding gas G1 ejected from the first nozzle 40 into multiple regions and changes the flow resistance for each divided region. For example, the first rectifying mechanism 60 divides the opening 43 into a central region and an outer region outside the central region. The central region is a region of the opening 43 from which gas is ejected toward the central axis of the laser beam. The outer region is a region surrounding the central region. The outer region is a region from which the first shielding gas G1 is ejected outside the central region. The first rectifying mechanism 60 makes the flow resistance of the central region, from which gas is ejected toward the central axis of the laser beam L, smaller than the flow resistance of the outer region, from which gas is ejected outside the central region.

[0062] In this embodiment, the first rectifying mechanism 60 divides the region (opening 43) in the direction (Y direction) in which the laser beam and the processing surface move relative to each other. In other words, the first rectifying mechanism 60 (opening 43) is divided by a first flow guide 70, which will be described later. The first rectifying mechanism 60 divides the region in the Y direction into, for example, a central first region 43a, a second region 43b on the upstream side (Y2 direction side), and a third region 43c on the downstream side (Y1 direction side). The first region 43a is preferably larger than the second region 43b and the third region 43c.

[0063] The first rectifying mechanism 60 also divides the region in a direction (Z direction) perpendicular to the direction of relative movement of the laser beam and the processing surface. The first rectifying mechanism 60 divides the region 43a, the second region 43b, and the third region 43c in the Z direction, for example. The first rectifying mechanism 60 divides the first region 43a into a fourth region 43d (center region) and a fifth region 43e (outer region). The first rectifying mechanism 60 divides the second region 43b into a sixth region 43f and a seventh region 43g. The first rectifying mechanism 60 divides the third region 43c into an eighth region 43h and a ninth region 43i.

[0064] The first rectifying mechanism 60 is attached to a frame 62 provided inside the opening 43. A partition 64 is provided in the Y direction inside the frame 62. The partition 64 divides the first rectifying mechanism 60 in the Z direction.

[0065] The first rectifying mechanism 60 is, for example, a wire mesh, a honeycomb-structured member, a porous member, or the like. The first rectifying mechanism 60 includes a central rectifying mechanism 60A and an outer rectifying mechanism 60B. The central rectifying mechanism 60A is a rectifying mechanism disposed in a fourth region 43d (central region) described below. The outer rectifying mechanism 60B is a rectifying mechanism disposed around the fourth region 53d. The central rectifying mechanism 60A is a rectifying mechanism with larger mesh (openings) than the outer rectifying mechanism 60B. In other words, the central rectifying mechanism 60A is a rectifying mechanism with a coarser mesh and lower flow resistance than the outer rectifying mechanism 60B. The central rectifying mechanism 60A is disposed in the fourth region 43d (central region) described below, and reduces the flow resistance of the central region, where gas is injected toward the central axis of the laser beam L, compared to the flow resistance of the outer region, where gas is injected outward from the central region. The outer rectifying mechanism 60B is provided in an outer region of the region surrounding the central region, and is a rectifying mechanism having smaller (finer) meshes and greater flow resistance than the central rectifying mechanism 60A.

[0066] The central rectifying mechanism 60A and the outer rectifying mechanism 60B of the first rectifying mechanism 60 may have different flow resistances, and are not limited to having different opening ratios based on the coarseness of the members arranged in the openings. The central rectifying mechanism 60A and the outer rectifying mechanism 60B of the first rectifying mechanism 60 may have different flow resistances by using different numbers of members with the same opening ratio. For example, the number of members in the central rectifying mechanism 60A is smaller than the number of members in the outer rectifying mechanism B. The central rectifying mechanism 60A and the outer rectifying mechanism 60B may also have different thicknesses. For example, the thickness of the central rectifying mechanism 60A is thinner than the thickness of the outer rectifying mechanism 60B.

[0067] For example, the fourth region 43d is the central region of the opening 43 and is located vertically below the fifth region 43e (partition 64). The fourth region 43d is preferably larger than the fifth region 43e. A central flow straightening mechanism 60A is provided in the fourth region 43d. The fifth region 43e is located vertically above the fourth region 43d. An outer flow straightening mechanism 60B is provided in the fifth region 43e.

[0068] Here, the fourth region 43d (central region) is provided with a central flow straightening mechanism 60A. In other words, the fifth region 43e to the ninth region 43i are provided with outer flow straightening mechanisms 60B with finer meshes than the central flow straightening mechanism 60A. In other words, the aperture ratio of the first flow straightening mechanisms 60 in the central region and the outer regions should be different so that the flow resistance in the central region is smaller. This allows the first nozzle 40 to make the flow resistance of the first shielding gas G1 different between the divided central region and outer region. The first nozzle 40 can make the flow resistance of the first shielding gas G1 in the central region smaller than the flow resistance in the outer region.

[0069] The partition 64 does not have to be provided. In this case, the rectifying mechanisms 60 are provided directly within the frame 62 of the opening 43. Furthermore, the frame 62 does not have to be provided. In this case, the rectifying mechanisms 60 are provided directly in the opening 43.

[0070] Furthermore, the first rectifying mechanism 60 is provided on the base 41. The first rectifying mechanism 60 provided on the base 41 is also attached to a frame 62. In the example shown in FIG. 10 , two rectifying mechanisms 60 are provided on the base 41, but the number is not limited to two. The first rectifying mechanism 60 provided on the base 41 may be a wire mesh, a honeycomb structure member, a porous member, or the like, and may be the same as or different from the first rectifying mechanism 60 provided in the opening 43. Furthermore, the frame 62 does not have to be provided. The first rectifying mechanism 60 does not have to be provided on the base 41.

[0071] 9 and 10 , the first flow guide 70 is disposed at the base portion 41 and the tip portion 42. In other words, the first flow guide 70 is disposed at the first flow path C11 and the second flow path C12. The first flow guide 70 is a plate-shaped member that guides the first shielding gas G1 flowing through the first flow path C11 and the second flow path C12. The first flow guide 70 divides the first flow path C21 and the second flow path C22. The first flow guide 70 includes a curved flow guide 72 disposed at the curved portion of the first nozzle 40 and an opening flow guide 74 extending from one side of the base portion 41 of the first nozzle 40 to the opening 43.

[0072] A plurality of curved flow guides 72 are arranged in the second flow path C12. The curved flow guides 72 are arranged at intervals in the Y direction. The curved flow guides 72 divide the second flow path C12 into a plurality of second flow paths C12. The curved flow guides 72 are arranged, for example, at a curved portion formed by the first curved surface 42c and the second curved surface 42d of the second flow path C12. The curved flow guides 72 extend from the curved portion of the second flow path C12 to just before the opening 43 (on the X2 direction side) and divide the second flow path C12 from the curved portion to just before the opening 43. In this embodiment, two curved flow guides 72 are arranged, but the number is not limited to two.

[0073] A plurality of opening flow guides 74 are arranged within the first nozzle 40. The opening flow guides 74 are arranged at intervals in the Y1 and X2 directions. The opening flow guides 74 are arranged downstream (in the Y1 direction) of the curved flow guide 72. The opening flow guides 74 extend from one side of the base 41 to the opening 43 within the first nozzle 40, dividing the first nozzle 40. That is, the opening flow guides 74 divide the first flow path C11 and the second flow path C12. The opening flow guides 74 divide the first flow path C11 into multiple first flow paths C11. The opening flow guides 74 divide the second flow path C12 into multiple second flow paths C12. The opening flow guides 74 can also be said to divide the first flow straightening mechanism 60 (opening 43) into divided regions. The opening flow guides 74 can also be said to divide the first flow straightening mechanism 60 (opening 43) into three regions. In the example shown in Figure 12, the opening flow guide 74 divides the opening 43 in the Y direction into a first region 43a in the center, a second region 43b on the upstream side (Y2 direction side), and a third region 43c on the downstream side (Y1 direction side).

[0074] In this embodiment, two opening flow guides 74 are disposed, but the number is not limited to two. Note that the opening flow guides 74 may extend from the curved portion of the second flow path C22 to the opening 43.

[0075] (Second Nozzle) The second nozzle 50 has a base 51 and a tip 52. The bottom surface 56 of the second nozzle 50 is located vertically above the machining surface 102. One end of the base 51 is connected to a shielding gas supply source, and the other end is connected to the tip 52. The base 51 is hollow, and a first flow path C21 is formed along the Y direction. One end of the tip 52 is connected to the end of the base 51 in the Y direction.

[0076] One end of the tip portion 52 is connected to the base portion 51, and the end not connected to the base portion 51 forms an opening 53. The tip portion 52 is hollow, and a second flow path C22 is formed in the tip portion 52, extending from the Y direction to the X direction. The tip portion 52 is inclined toward the movement direction with respect to the second direction. As the tip portion 52 extends from the base portion 51 toward the opening 53, the tip portion 52 faces the second direction and is inclined toward the movement direction. The second shielding gas G2 flows from the base portion 51 through the tip portion 52, and is ejected from the opening 53 toward the machining surface 102.

[0077] The tip portion 52 has a first side surface 52a on the movement direction side, a first curved surface 52c, and a second curved surface 52d. The tip portion 52 is connected to the base portion 51 via the first curved surface 52c and the second curved surface 52d. The first side surface 52a is inclined toward the movement direction with respect to the second direction. The first curved surface 52c is formed on the movement direction side and curves to protrude in the horizontal direction (X1 direction). The second curved surface 52d is formed on the opposite side to the movement direction and curves to protrude in the horizontal direction (X1 direction). The first curved surface 52c is formed more gently than the second curved surface 52d. The first curved surface 52c is connected to the side surface of the base portion 51 on the X1 direction side. The second curved surface 52d is formed steeper than the first curved surface 52c. The second curved surface 52d forms the side surface of the base portion 51 on the X2 direction side. The tip portion 52 may have a second side surface 52b.

[0078] 9, the opening 53 faces the processing surface 102. The opening 53 is parallel to the Y direction. The opening 53 is inclined toward the processing surface 102 in the X direction.

[0079] 13, the opening 53 of the second nozzle 50 is viewed in the X2 direction. As shown in Fig. 13, the opening 53 is divided. In this embodiment, the opening 53 is provided with a second flow straightening mechanism 60.

[0080] The second rectifying mechanism 60 is disposed in the opening 53 and rectifies the flow of the second shielding gas G2. The second rectifying mechanism 60 divides the second shielding gas G2 ejected from the second nozzle 50 into multiple regions and changes the flow resistance for each divided region. For example, the second rectifying mechanism 60 divides the opening 53 into a central region and an outer region outside the central region. The central region is a region of the opening 53 from which gas is ejected toward the central axis of the laser beam. The outer region is a region surrounding the central region. The outer region is a region from which the second shielding gas G2 is ejected outside the central region. The second rectifying mechanism 60 makes the flow resistance of the central region, from which gas is ejected toward the central axis of the laser beam L, smaller than the flow resistance of the outer region, from which gas is ejected outside the central region.

[0081] In this embodiment, the second rectifying mechanism 60 divides the region (opening 53) in the direction (Y direction) in which the laser beam and the processing surface move relative to each other. In other words, the second rectifying mechanism 60 (opening 53) is divided by a second flow guide 80, which will be described later. The second rectifying mechanism 60 divides the opening 53 in the Y direction into a first region 53a in the center, a second region 53b on the upstream side (Y2 direction side), and a third region 53c on the downstream side (Y1 direction side). It is preferable that the first region 53a be larger than the second region 53b and the third region 53c.

[0082] The second rectifying mechanism 60 also divides the region in a direction (Z direction) perpendicular to the direction of relative movement of the laser beam and the processing surface. The second rectifying mechanism 60 divides the region 53a, the second region 53b, and the third region 53c in the Z direction, for example. The second rectifying mechanism 60 divides the first region 53a into a fourth region 53d (center region) and a fifth region 53e (outer region). The second rectifying mechanism 60 divides the second region 53b into a sixth region 53f and a seventh region 53g. The second rectifying mechanism 60 divides the third region 53c into an eighth region 53h and a ninth region 53i.

[0083] The second rectifying mechanism 60 is attached to a frame 62 provided inside the opening 53. A partition 64 is provided in the Y direction inside the frame 62. The partition 64 divides the second rectifying mechanism 60 in the Z direction.

[0084] The second rectifying mechanism 60 is, for example, a wire mesh, a honeycomb-structured member, a porous member, or the like. The second rectifying mechanism 60 includes a central rectifying mechanism 60A and an outer rectifying mechanism 60B. The central rectifying mechanism 60A is a rectifying mechanism disposed in a fourth region 53d (central region) described below. The outer rectifying mechanism 60B is a rectifying mechanism disposed around the fourth region 53d. The central rectifying mechanism 60A is a rectifying mechanism with a larger mesh (opening) than the outer rectifying mechanism 60B. In other words, the central rectifying mechanism 60A is a rectifying mechanism with a coarser mesh and lower flow resistance than the outer rectifying mechanism 60B. The central rectifying mechanism 60A is disposed in the fourth region 53d (central region) described below, and reduces the flow resistance of the central region, where gas is injected toward the central axis of the laser beam L, compared to the flow resistance of the outer region, where gas is injected outward from the central region. The outer rectifying mechanism 60B is provided in an outer region of the region surrounding the central region, and is a rectifying mechanism having smaller (finer) meshes and greater flow resistance than the central rectifying mechanism 60A.

[0085] The central rectifying mechanism 60A and the outer rectifying mechanism 60B of the second rectifying mechanism 60 may have different flow resistances, and are not limited to having different opening ratios based on the coarseness of the members arranged in the openings. The central rectifying mechanism 60A and the outer rectifying mechanism 60B of the second rectifying mechanism 60 may have different flow resistances by using different numbers of members with the same opening ratio. For example, the number of members in the central rectifying mechanism 60A is smaller than the number of members in the outer rectifying mechanism 60B. The central rectifying mechanism 60A and the outer rectifying mechanism 60B may also have different thicknesses. For example, the thickness of the central rectifying mechanism 60A is thinner than the thickness of the outer rectifying mechanism 60B.

[0086] For example, the fourth region 53d is the central region of the opening 53 and is located vertically above the fifth region 53e (partition 64). The fourth region 53d is preferably larger than the fifth region 53e. A central flow straightening mechanism 60A is provided in the fourth region 53d. The fifth region 53e is located vertically below the fourth region 53d. An outer flow straightening mechanism 60B is provided in the fifth region 53e.

[0087] Here, the fourth region 53d (central region) is provided with a central flow straightening mechanism 60A. In other words, the fifth region 53e to the ninth region 53i are provided with outer flow straightening mechanisms 60B with finer meshes than the central flow straightening mechanism 60A. In other words, the aperture ratio of the second flow straightening mechanisms 60 in the central region and the outer regions should be different so that the flow resistance in the central region is smaller. This allows the second nozzle 50 to make the flow resistance of the second shielding gas G2 different between the divided central region and outer region. The second nozzle 50 can make the flow resistance of the second shielding gas G2 in the central region smaller than the flow resistance in the outer region.

[0088] The opening 53 is divided by being inverted with respect to the opening 43 so that the fifth region 53e, the seventh region 53g, and the ninth region 53i are located on the vertically lower side (the machining surface 102) side, but may also be divided so that the seventh region 53g and the ninth region 53i are located on the vertically upper side, as with the opening 43. The second flow straightening mechanism 60 may be the same flow straightening mechanism as the first flow straightening mechanism 60 provided in the first nozzle 40.

[0089] The partition 64 does not have to be provided. In this case, the rectifying mechanisms 60 are provided directly within the frame 62 of the opening 43. Furthermore, the frame 62 does not have to be provided. In this case, the rectifying mechanisms 60 are provided directly in the opening 43.

[0090] Further, the second rectifying mechanism 60 is provided on the base 51. The second rectifying mechanism 60 provided on the base 51 is also attached to the frame 62. In the example shown in FIG. 10 , two second rectifying mechanisms 60 are provided on the base 51, but the number is not limited to two. The second rectifying mechanism 60 provided on the base 51 may be a wire mesh, a honeycomb structure member, a porous member, or the like, and may be the same as or different from the second rectifying mechanism 60 provided in the opening 53. Furthermore, the frame 62 does not have to be provided. The second rectifying mechanism 60 does not have to be provided on the base 51.

[0091] 9 and 10 , the second flow guides 80 are disposed at the base portion 51 and the tip portion 52. In other words, the second flow guides 80 are disposed at the first flow path C21 and the second flow path C22. The second flow guides 80 are plate-shaped members that guide the second shielding gas G2 flowing through the first flow path C21 and the second flow path C22. The second flow guides 80 divide the first flow path C21 and the second flow path C22. The second flow guides 80 include a curved flow guide 82 disposed at the curved portion of the second nozzle 50 and an opening flow guide 84 that extends from one side of the base portion 51 of the second nozzle 50 to the opening 53.

[0092] A plurality of curved flow guides 82 are arranged in the second flow path C22. The curved flow guides 82 are arranged at intervals in the Y direction. The curved flow guides 82 divide the second flow path C22 into a plurality of second flow paths C22. The curved flow guides 82 are arranged, for example, at a curved portion formed by the first curved surface 52c and the second curved surface 52d of the second flow path C22. The curved flow guides 82 extend from the curved portion of the second flow path C22 to just before the opening 53 (on the X1 direction side), and divide the second flow path C22 from the curved portion to just before the opening 53. In this embodiment, two curved flow guides 82 are arranged, but the number is not limited to two.

[0093] A plurality of opening flow guides 84 are arranged within the second nozzle 50. The opening flow guides 84 are arranged at intervals in the Y1 and X2 directions. The opening flow guides 84 are arranged downstream (in the Y1 direction) of the curved flow guide 82. The opening flow guides 84 extend from one side of the base 51 to the opening 53 within the second nozzle 50, dividing the second nozzle 50. That is, the opening flow guides 84 divide the first flow path C21 and the second flow path C22. The opening flow guides 84 divide the first flow path C21 into multiple first flow paths C21. The opening flow guides 84 divide the second flow path C22 into multiple second flow paths C22. The opening flow guides 84 can also be said to divide the second flow straightening mechanism 60 (opening 43) into divided regions. The opening flow guides 84 can also be said to divide the second flow straightening mechanism 60 (opening 53) into three regions. In the example shown in Figure 13, the opening flow guide 84 divides the opening 53 in the Y direction into a first region 53a in the center, a second region 53b on the upstream side (Y2 direction side), and a third region 53c on the downstream side (Y1 direction side).

[0094] In this embodiment, two opening flow guides 84 are disposed, but the number is not limited to two. Note that the opening flow guides 84 may extend from the curved portion of the second flow path C22 to the opening 53.

[0095] <Supply of Shielding Gas> The first shielding gas G1 that collides with the second shielding gas G2 (first shielding gas G1 after collision) flows in the direction of movement and in the opposite direction to the direction of movement. For example, the first shielding gas G1 after collision flows from near the center of the opening 43 in the direction of movement and in the opposite direction to the direction of movement. In the example shown in Fig. 10 , the first shielding gas G1 after collision flows from near the center of the opening 43 in the directions of arrows A11 and a11 and arrows B11 and b11.

[0096] The second shielding gas G2 that collides with the first shielding gas G1 (the second shielding gas G2 after collision) flows in the direction of movement and in the opposite direction to the direction of movement. For example, the second shielding gas G2 after collision flows from near the center of the opening 53 in the direction of movement and in the opposite direction to the direction of movement. In the example shown in Fig. 10, the second shielding gas G2 after collision flows from near the center of the opening 53 in the directions of arrows A21 and a21 and arrows B21 and b21.

[0097] Here, the flow resistance in the central regions of the openings 43 and 53 is smaller than the flow resistance on the upstream side (Y2 direction) and the downstream side (Y1 direction), i.e., the flow resistance in the outer regions. Therefore, the pressure generated by the collision of the first shielding gas G1 and the second shielding gas G2 at the centers of the openings 43 and 53 is higher than the pressure on the upstream side and the pressure on the downstream side. Specifically, the pressure generated by the collision of the first shielding gas G1 ejected from the first region 43a at the center of the first nozzle 40 and the second shielding gas G2 ejected from the first region 53a at the center of the second nozzle 50 is the highest. More specifically, the pressure generated by the collision of the first shielding gas G1 ejected from the fourth region 43d (central region) of the first nozzle 40 and the second shielding gas G2 ejected from the fourth region 53d (central region) of the second nozzle 50 is the highest. This allows the shielding gas supply device 30 to suppress the amount of air flowing into the shielded area by the pressure generated in the center when the first shielding gas G1 and the second shielding gas G2 collide.

[0098] <Another Example of Fourth Embodiment> FIGS. 14 and 15 are diagrams for explaining another example of a shielding gas supply device according to the fourth embodiment.

[0099] In another example of the fourth embodiment, the shielding gas supply device 30 may change the ejection range of the shielding gas. In Fig. 15, for example, the shielding gas supply device 30 has a switching means (switching device) that changes the ejection range of the shielding gas ejected from the openings 43, 53 of the first nozzle 40 and the second nozzle 50. In Fig. 14, the processing apparatus 1B moves in the movement direction (Y1 direction). As shown in Fig. 14, the first nozzle 40 of the shielding gas supply device 30 supplies the first shielding gas G1 to two first flow paths C11 divided by the opening flow guide 74 of the first flow guide 70, and the first shielding gas G1 is ejected from two regions of the opening 43. The first nozzle 40 supplies the first shielding gas G1 to the central first flow path C11 and the first flow path C11 on the Y2 direction side, passes through the two first flow paths C11 and the second flow path C12 divided by the curved flow guide 72 of the first flow guide 70, and is ejected from the first region 43a and the second region 43b. The second nozzle 50 supplies the second shielding gas G2 to the two first flow paths C21 divided by the opening flow guide 84 of the second flow guide 80, and is ejected from the two regions of the opening 53. The second nozzle 50 supplies the second shielding gas G2 to the central first flow path C21 divided by the opening flow guide 84 and the first flow path C21 on the Y2 direction side, passes through the two first flow paths C21 and the second flow path C22 divided by the curved flow guide 82 of the second flow guide 80, and is ejected from the first region 53a and the second region 53b.

[0100] 15 , for example, the shielding gas supply device 30 includes a switching device 90 for changing the spray range of the shielding gas sprayed from the openings 43, 53 of the first nozzle 40 and the second nozzle 50. The switching device 90 is connected to the base of the shielding gas supply device 30. In FIG. 15 , the processing apparatus 1B moves in the direction opposite to the movement direction (Y2 direction). The switching device 90 switches the spray range of the first shielding gas G1 and the second shielding gas G2. The switching device 90 switches the supply path of the first shielding gas G1. The switching device 90 switches the supply path of the second shielding gas G2. For example, as shown in FIG. 15 , the first nozzle 40 of the shielding gas supply device 30 supplies the first shielding gas G1 to two first flow paths C11 divided by the opening flow guide 74 of the first flow guide 70, and the first shielding gas G1 is sprayed from two regions of the opening 43. The switching device 90 switches a portion of the supply path of the first shielding gas G1 from the first flow path C11 (see FIG. 14 ) on the Y2-direction side of the first nozzle 40 to the first flow path C11 on the Y1-direction side of the first nozzle 40, and supplies the first shielding gas G1 to the central first flow path C11 and the first flow path C11 on the Y1-direction side, passes through the two first flow paths C11 and a second flow path C12 divided by the curved flow guide 72 of the first flow guide 70, and is ejected from the first region 43 a and the second region 43 b. The second nozzle 50 supplies the second shielding gas G2 to the two first flow paths C21 divided by the opening flow guide 84 of the second flow guide 80, and is ejected from two regions of the opening 53. The switching device 90 switches the supply path of the second shielding gas G2 from the first flow path C11 (see FIG. 14) on the Y2 side of the second nozzle 50 to the first flow path C21 on the Y1 side of the second nozzle 50, and supplies the second shielding gas G2 to the central first flow path C21 divided by the opening flow guide 84 of the second flow guide 80 and the first flow path C21 on the Y1 side, and passes the second shielding gas G2 through the two first flow paths C21 and the second flow path C22 divided by the curved flow guide 82, and is ejected from the first region 53 a and the second region 53 b.

[0101] <Effects of Fourth Embodiment> In the machining apparatus 1B of the fourth embodiment, the shielding gas supply device 30 is disposed vertically above the machining surface 102. That is, the first nozzle 40 and the second nozzle 50 are disposed vertically above the machining surface 102, and the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are inclined vertically downward. This allows the shielding gas supply device 30 to eject the first shielding gas G1 and the second shielding gas G2 onto the machining surface 102. Furthermore, the shielding gas supply device 30 can supply inert gas even to a machining surface that is wider than the distance between the first nozzle 40 and the second nozzle 50.

[0102] Furthermore, in the machining apparatus 1B of the fourth embodiment, the interior of the first nozzle 40 and the interior of the second nozzle 50 of the shielding gas supply device 30 are divided by a first flow guide 70, a second flow guide 80, a first rectifying mechanism 60, and a second rectifying mechanism 60. This allows the shielding gas supply device 30 to adjust the flow rate (flow velocity) of the shielding gas for each divided area. Furthermore, the shielding gas ejected from the shielding gas supply device 30 and colliding with the openings 43 and 53 has the highest pressure at the center of the openings 43 and 53. Therefore, the shielding gas supply device 30 can suppress the amount of air flowing into the shielded area by the pressure generated at the center when the first shielding gas G1 and the second shielding gas G2 collide. Furthermore, the shielding gas supply device 30 can widen the area covered by the shield with an appropriate amount of shielding gas.

[0103] Furthermore, the processing apparatus 1B changes the shielding gas ejection range. This allows the shielding gas supply device 30 of the processing apparatus 1B to cover the shielding range GAr required for processing. Furthermore, even if the processing apparatus 30B changes the movement direction in the opposite direction to the movement direction, it can perform processing without shifting the position of the molten material 26 in the opposite direction to the movement direction. Furthermore, by changing the shielding gas ejection range, the processing apparatus 1B can eject an appropriate amount of shielding gas while covering the range requiring shielding gas with shielding gas.

[0104] <Effects of the Present Disclosure> The shielding gas supply device according to the first aspect of the present disclosure is a shielding gas supply device that supplies shielding gas to an area where a laser beam L is irradiated from above in the vertical direction onto a processing surface 102, and includes: a first nozzle 40 that is arranged on one side of the processing surface 102 and that sprays a first shielding gas G1, which is an inert gas, from an opening 43 in a first direction from one side of the processing surface 102 to the other side; and a second nozzle 50 that is arranged on the other side of the processing surface 102 and that sprays a second shielding gas G2, which is an inert gas, from an opening 53 in a second direction from the other side of the processing surface 102 to the one side, and the first nozzle 40 and the second nozzle 50 are located away from the central axis of the laser beam L, and the opening 43 of the first nozzle 40 and the opening 53 of the second nozzle 50 are opposed to each other.

[0105] According to the present disclosure, shielding gas can be supplied appropriately.

[0106] A shielding gas supply device according to a second aspect of the present disclosure is the shielding gas supply device according to the first aspect, wherein the first nozzle 40 ejects the inert gas in a direction inclined relative to the first direction, which is the direction of movement, that is the direction of machining, and the second nozzle 50 ejects the inert gas in a direction inclined relative to the second direction, which is the direction of movement, that is the direction of machining, thereby enabling an appropriate supply of shielding gas.

[0107] A shielding gas supply device according to a third aspect of the present disclosure is the shielding gas supply device according to the first or second aspect, wherein the first nozzle (40) has a tip (42) in which an opening (43) is formed that extends at an incline toward the movement direction with respect to the first direction, and the second nozzle (50) has a tip (52) in which an opening (53) is formed that extends at an incline toward the movement direction with respect to the second direction. Therefore, the molten zone immediately after processing can be covered with shielding gas, and oxidation of the molten zone can be suppressed.

[0108] A shielding gas supply device according to a fourth aspect of the present disclosure is the shielding gas supply device according to any one of the first to third aspects, wherein the irradiation position 104 of the laser beam L on the processing surface 102 is located on the movement direction side, which is the processing direction, of the center points of the openings 43, 53 of the first nozzle 40 and the second nozzle 50. Therefore, the molten zone immediately after processing can be covered with shielding gas, and oxidation of the molten zone can be suppressed.

[0109] A shielding gas supply device according to a fifth aspect of the present disclosure is the shielding gas supply device according to the third aspect, wherein the tip portions 42, 52 of the first nozzle 40 and the second nozzle 50 have first side surfaces 42 a, 52 a on the movement direction side and second side surfaces 42 b, 52 b on the opposite side to the movement direction, the first side surface 42 a and the second side surface 42 b of the first nozzle 40 are inclined toward the movement direction with respect to the first direction, and when viewed in the vertical direction, the angle θ1 formed between the first side surface 42 a and the first direction is larger than the angle θ2 formed between the second side surface 42 b and the first direction, and the first side surface 52 a and the second side surface 52 b of the second nozzle 50 are inclined toward the movement direction 108 with respect to the second direction, and when viewed in the vertical direction, the angle θ1 formed between the first side surface 52 a and the second direction is larger than the angle θ2 formed between the second side surface 52 b and the second direction. Therefore, the first nozzle and the second nozzle can jet out the inert gas obliquely, and the flow of the jetted inert gas can be controlled in one direction so that the inert gas flows in the direction of movement.

[0110] A shielding gas supply device according to a sixth aspect of the present disclosure is the shielding gas supply device according to any one of the first to fifth aspects, wherein the bottom surface 46 of the first nozzle 40 and the bottom surface 56 of the second nozzle 50 are positioned vertically below the processing surface 102. This makes it possible to prevent the inert gas ejected from the first nozzle 40 and the second nozzle 50 from mixing with oxygen in the air.

[0111] A shielding gas supply device according to a seventh aspect of the present disclosure is the shielding gas supply device according to any one of the first to sixth aspects, in which the first nozzle 40 and the second nozzle 50 are disposed vertically above the machining surface 102, and the openings 43, 53 are inclined vertically downward. By arranging the first nozzle and the second nozzle in this manner, it is possible to machine an object that is wider than the width of the openings of the first nozzle and the second nozzle.

[0112] A shielding gas supply device according to an eighth aspect of the present disclosure is the shielding gas supply device according to any one of the first to seventh aspects, wherein a rectifying mechanism for rectifying the flow of the inert gas is provided in the first nozzle 40 and the second nozzle 50. This reduces turbulence in the flow of the inert gas and suppresses mixing of the inert gas with air.

[0113] A shielding gas supply device according to a ninth aspect of the present disclosure is the shielding gas supply device according to any one of the first to eighth aspects, wherein the inert gas is either nitrogen gas or a rare gas, thereby suppressing oxidation of the molten zone.

[0114] A shielding gas supply device according to a tenth aspect of the present disclosure is the shielding gas supply device according to any one of the first to ninth aspects, including a first rectification mechanism (60) disposed in a first nozzle (40) and rectifying the flow of the first shielding gas (G1) sprayed from an opening (43) of the first nozzle (40), and a second rectification mechanism (60) disposed in a second nozzle (50) and rectifying the flow of the second shielding gas (G2) sprayed from an opening (53) of the second shielding gas (G2), the first rectification mechanism (60) dividing the first shielding gas (G1) sprayed from the first nozzle (40) into a plurality of regions, The second flow straightening mechanism 60 divides the second shielding gas G2 injected from the second nozzle 50 into multiple regions and changes the flow resistance for each region, making the flow resistance of the central region where the second shielding gas G2 is injected toward the central axis of the laser beam L smaller than the flow resistance of the outer region where the first shielding gas G1 is injected outside the central region. The second flow straightening mechanism 60 divides the second shielding gas G2 injected from the second nozzle 50 into multiple regions and changes the flow resistance for each region, making the flow resistance of the central region where the second shielding gas G2 is injected toward the central axis of the laser beam L smaller than the flow resistance of the outer region where the second shielding gas G2 is injected outside the central region. Therefore, the shielding gas supply device 30 can adjust the flow rate of the shielding gas for each divided region. More specifically, the shielding gas supply device 30 can make the flow resistance of the central region smaller than the flow resistance of the outer region.

[0115] A shielding gas supply device according to an eleventh aspect of the present disclosure is the shielding gas supply device according to the tenth aspect, wherein the first rectifying mechanism 60 and the second rectifying mechanism 60 divide the regions in the direction in which the laser beam L and the processing surface 102 move relative to each other. Therefore, the shielding gas supply device 30 can adjust the flow rate of the shielding gas for each divided region. More specifically, the shielding gas supply device 30 can make the flow resistance of the central region smaller than the flow resistance of the outer regions.

[0116] A shielding gas supply device according to a twelfth aspect of the present disclosure is the shielding gas supply device according to the tenth or eleventh aspect, wherein the first rectification mechanism 60 and the second rectification mechanism 60 divide the region in a direction perpendicular to the direction of relative movement of the laser beam L and the processing surface. Therefore, the shielding gas supply device 30 can adjust the flow rate of the shielding gas for each divided region. More specifically, the shielding gas supply device 30 can make the flow resistance of the central region smaller than the flow resistance of the outer regions.

[0117] A shielding gas supply device according to a thirteenth aspect of the present disclosure is the shielding gas supply device according to any one of the tenth to twelfth aspects, and includes a switching means 90 for changing the ejection ranges of the shielding gases G1, G2 ejected from the openings of the first nozzle 40 and the second nozzle 50. Therefore, the shielding gas supply device 30 can perform processing without shifting the position of the molten material 26 in the direction opposite to the moving direction even when the moving direction is changed in the direction opposite to the moving direction. Furthermore, by changing the ejection range of the shielding gas, the shielding gas supply device 30 can eject an appropriate amount of shielding gas while covering the area requiring the shielding gas with the shielding gas.

[0118] A shielding gas supply device according to a fourteenth aspect of the present disclosure includes a first flow guide 70 disposed in the flow path of the first nozzle 40, guiding the first shielding gas G1 flowing through the first nozzle 40 and dividing the flow path of the first nozzle 40 into the divided regions of the first flow straightening mechanism 60, and a second flow guide 80 disposed in the flow path of the second nozzle 50, guiding the second shielding gas G2 flowing through the second nozzle 50 and dividing the flow path of the second nozzle 50 into the divided regions of the second flow straightening mechanism 60. Therefore, the shielding gas supply device 30 can adjust the flow rate of the shielding gas for each divided region. More specifically, the shielding gas supply device 30 can make the flow resistance in the central region smaller than the flow resistance in the outer regions.

[0119] A shielding gas supply device according to a fifteenth aspect of the present disclosure is the shielding gas supply device according to any one of the tenth to fourteenth aspects, in which the first nozzle 40 and the second nozzle 50 are disposed vertically above the machining surface 102, and the openings 43, 53 are inclined vertically downward. Therefore, by arranging the first nozzle and the second nozzle in this manner, it is possible to machine an object that is wider than the width of the openings of the first nozzle and the second nozzle.

[0120] The shielding gas supply method according to the sixteenth aspect of the present disclosure is a shielding gas supply method for supplying shielding gas to an area where a laser beam L is irradiated from above in the vertical direction onto a processing surface 102, and includes a step of spraying a first shielding gas G1, which is an inert gas, from an opening 43 in a first direction from one side of the processing surface 102 to the other side, and a step of spraying a second shielding gas G2, which is an inert gas, from an opening 53 in a second direction from the other side of the processing surface 102 to the one side.

[0121] According to the present disclosure, shielding gas can be supplied appropriately.

[0122] Although the embodiments of the present invention have been described above, the embodiments are not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the scope of what is called equivalents. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments.

[0123] REFERENCE SIGNS LIST 1 Processing device 10 Irradiation section 20 Melt supply section 30 Shielding gas supply device 40 First nozzle 50 Second nozzle 41, 51 Base 42, 52 Tip 42a, 52a First side 42b, 52b Second side 43, 53 Opening 60 Straightening mechanism, first straightening mechanism, second straightening mechanism 70 First flow guide 80 Second flow guide 90 Switching device (switching means) 100 Object 102 Processing surface 104 Irradiation position 106 Melting part G1 First shielding gas G2 Second shielding gas

Claims

1. A shielding gas supply device that supplies shielding gas to an area where a laser beam is irradiated from above in the vertical direction onto a machining surface, comprising: a first nozzle that is arranged on one side of the machining surface and that sprays a first shielding gas, which is an inert gas, from an opening in a first direction from one side of the machining surface to the other side; and a second nozzle that is arranged on the other side of the machining surface and that sprays a second shielding gas, which is an inert gas, from an opening in a second direction from the other side of the machining surface to the one side, wherein the first nozzle and the second nozzle are located away from the central axis of the laser beam, and the opening of the first nozzle and the opening of the second nozzle face each other.

2. A shielding gas supply device as described in claim 1, wherein the first nozzle ejects the inert gas in a direction inclined toward the movement direction, which is the machining direction, relative to the first direction, and the second nozzle ejects the inert gas in a direction inclined toward the movement direction, which is the machining direction, relative to the second direction.

3. A shielding gas supply device as described in claim 2, wherein the tip of the first nozzle, where the opening is formed, extends at an incline toward the movement direction with respect to the first direction, and the tip of the second nozzle, where the opening is formed, extends at an incline toward the movement direction with respect to the second direction.

4. A shielding gas supply device as described in claim 1 or claim 2, wherein the irradiation position of the laser beam on the processing surface is located on the movement direction side, which is the processing direction, of the center point of the openings of the first nozzle and the second nozzle.

5. A shielding gas supply device as set forth in claim 3, wherein the tip portions of the first nozzle and the second nozzle have a first side surface on the side of the movement direction and a second side surface opposite to the movement direction, the first side surface and the second side surface of the first nozzle are inclined toward the movement direction with respect to the first direction, and when viewed from the vertical direction, the angle formed by the first side surface and the first direction is larger than the angle formed by the second side surface and the first direction, and the first side surface and the second side surface of the second nozzle are inclined toward the movement direction with respect to the second direction, and when viewed from the vertical direction, the angle formed by the first side surface and the second direction is larger than the angle formed by the second side surface and the second direction.

6. A shielding gas supply device according to claim 1 or claim 2, wherein the bottom surfaces of the first nozzle and the second nozzle are positioned vertically below the machining surface.

7. A shielding gas supply device according to claim 1 or claim 2, wherein the first nozzle and the second nozzle are arranged vertically above the machining surface, and their openings are inclined vertically downward.

8. A shielding gas supply device according to claim 1 or claim 2, wherein the first nozzle and the second nozzle are provided with a flow straightening mechanism for straightening the flow of the inert gas.

9. A shielding gas supply device according to claim 1 or 2, wherein the inert gas is either nitrogen gas or a rare gas.

10. A shielding gas supply device as set forth in claim 1 or claim 2, comprising: a first rectification mechanism disposed in the first nozzle for rectifying the first shielding gas sprayed from the opening of the first nozzle; and a second rectification mechanism disposed in the second nozzle for rectifying the second shielding gas sprayed from the opening of the second nozzle, wherein the first rectification mechanism divides the first shielding gas sprayed from the first nozzle into a plurality of regions and varies the flow resistance for each region, making the flow resistance of a central region where gas is sprayed toward the central axis of the laser beam smaller than the flow resistance of outer regions where gas is sprayed outward from the central region; and the second rectification mechanism divides the second shielding gas sprayed from the second nozzle into a plurality of regions and varies the flow resistance for each region, making the flow resistance of the central region where gas is sprayed toward the central axis of the laser beam smaller than the flow resistance of outer regions where gas is sprayed outward from the central region.

11. The shielding gas supply device according to claim 10, wherein the first rectifying mechanism and the second rectifying mechanism divide an area in the direction in which the laser beam and the processing surface move relative to each other.

12. The shielding gas supply device according to claim 10, wherein the first rectifying mechanism and the second rectifying mechanism divide the region in a direction perpendicular to the direction in which the laser beam and the processing surface move relative to each other.

13. The shielding gas supply device according to claim 10, further comprising a switching means for changing the spray range of the shielding gas sprayed from the openings of the first nozzle and the second nozzle.

14. A shielding gas supply device as described in claim 10, comprising: a first flow guide disposed in the flow path of the first nozzle, guiding the first shielding gas flowing through the first nozzle and dividing the flow path of the first nozzle into divided areas of the first flow straightening mechanism; and a second flow guide disposed in the flow path of the second nozzle, guiding the second shielding gas flowing through the second nozzle and dividing the flow path of the second nozzle into divided areas of the second flow straightening mechanism.

15. A shielding gas supply device according to claim 10, wherein the first nozzle and the second nozzle are arranged vertically above the machining surface, and the openings are inclined vertically downward.

16. A shielding gas supply method for supplying shielding gas to an area where a laser beam is irradiated from above in the vertical direction onto a machining surface, comprising the steps of: spraying a first shielding gas, which is an inert gas, from an opening in a first direction from one side of the machining surface to the other side; and spraying a second shielding gas, which is an inert gas, from an opening in a second direction from the other side of the machining surface to one side.

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