Laser welding device and laser welding method

Abstract

To prevent fume from adhering to a protective optical member.SOLUTION: A laser welding device 100 comprises a laser scanner, a protective optical member 4, an upper gas supply unit 1 and a lower gas supply unit. The protective optical member comprises a plate-like part 4a and a cylindrical part 4b extending downward from an outer edge of the plate-like part. The upper gas supply unit is arranged closer to a lower side than the plate-like part of the protective optical member, and comprises a first jetting port 1c for jetting gas to a center of the plate-like part and a second jetting port for jetting gas to a lower side of the plate-like part. The cylindrical part is provided between the upper gas supply unit and the lower gas supply unit and has a gas introduction port 3 through which gas is introduced from the outside of the cylindrical part to the inside thereof. The lower gas supply unit comprises a lower jetting port that jest gas downward from a lower end of the cylindrical part. Areas of the first jetting port are larger than areas of the second jetting port. A jetting direction of the first jetting port inclines with respect to a radial direction of the cylindrical part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a laser welding apparatus and a laser welding method. [Background technology]

[0002] The laser welding device disclosed in Patent Document 1 includes an air blowing unit that blows air in a direction crossing the optical path of the laser light irradiated from the laser scanner body. This air flow is said to prevent spatters scattered from the laser irradiation position on the workpiece during laser welding from adhering to a protective glass attached near the emission opening of the laser scanner body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-202411 A Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present application have discovered the following problem: In such a laser welding apparatus, a part of the air may flow upward. In such a case, there is a risk that the fumes may adhere to a protective optical member such as a protective glass.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and provides a laser welding apparatus and a laser welding method thereof that can prevent a portion of the air from flowing upward and causing fumes to adhere to a protective optical component. [Means for solving the problem]

[0006] In order to achieve the above object, one aspect of the present disclosure is to A laser scanner; A laser welding apparatus including a protective optical member disposed between the laser scanner and a workpiece, An upper gas supply unit; a lower gas supply unit provided below the upper gas supply unit, the protective optical member includes a plate-shaped portion and a cylindrical portion extending downward from an outer edge of the plate-shaped portion, the upper gas supply unit is provided below the plate-shaped portion of the protective optical member, the upper gas supply unit includes a plurality of first injection ports that inject gas toward a center of the plate-shaped portion and a plurality of second injection ports that inject gas toward a lower side of the plate-shaped portion; the cylindrical portion is provided between the upper gas supply unit and the lower gas supply unit, and has a plurality of gas inlet ports for introducing gas from an outside to an inside of the cylindrical portion; the lower gas supply unit includes a plurality of lower injection ports configured to inject gas downward from a lower end of the cylindrical portion, The area of ​​the first injection port is larger than the area of ​​the second injection port, The injection direction of the first injection port is inclined with respect to the radial direction of the cylindrical portion. Laser Welding Equipment It is. In this embodiment, the ratio of the area of ​​the first injection port to the area of ​​the second injection port may be set to 2.7:1. In this embodiment, the inclination angle of the jetting direction of the first jet nozzle may be set to 5°. In this embodiment, the multiple second injection ports may inject gas from the outer edge of the plate-shaped portion in a direction inclined toward the optical axis of the laser, or may inject gas from the outer edge of the plate-shaped portion in a direction parallel to the optical axis of the laser. In order to achieve the above object, one aspect of the present disclosure is to A laser scanner; a protective optical member disposed between the laser scanner and the workpiece and having a plate-shaped portion and a cylindrical portion extending downward from an outer edge of the plate-shaped portion; an upper gas supply unit provided below the plate-shaped portion of the protective optical member, the upper gas supply unit having a plurality of first injection ports for injecting gas toward a center of the plate-shaped portion and a plurality of second injection ports for injecting gas toward a lower side of the plate-shaped portion; a lower gas supply unit provided below the upper gas supply unit; A laser welding method for a laser welding apparatus comprising: a plurality of gas inlet ports of the cylindrical portion provided between the upper gas supply unit and the lower gas supply unit introduce gas from the outside to the inside of the cylindrical portion; a plurality of lower injection ports of the lower gas supply unit inject gas downward from a lower end of the cylindrical portion; The first jet port having a larger jet port area than the second jet port injects gas in a jet direction inclined with respect to a radial direction of the cylindrical portion. Laser welding method for laser welding device It is. Effect of the Invention

[0007] According to the present disclosure, a portion of the air flows upward, making it possible to suppress adhesion of fumes to the protective optical member. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a top view of the laser welding apparatus according to the embodiment. [Diagram 2] 2 is a cross-sectional view of the laser welding apparatus shown in FIG. 1. [Diagram 3] 2 is a perspective view of an upper gas supply unit of the laser welding apparatus shown in FIG. 1. [Figure 4] 2 is a perspective view of a lower gas supply unit of the laser welding apparatus shown in FIG. 1. [Diagram 5] FIG. [Figure 6] 11A to 11C are diagrams showing experimental results using the laser welding device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] This embodiment will be described with reference to Figs. 1 to 6. Fig. 1 is a top view of a laser welding apparatus according to this embodiment. Fig. 2 is a cross-sectional view of the laser welding apparatus shown in Fig. 1. Fig. 3 is a perspective view of an upper gas supply unit of the laser welding apparatus shown in Fig. 1. Fig. 4 is a perspective view of a lower gas supply unit of the laser welding apparatus shown in Fig. 1. In Fig. 2, only the reference symbols are shown for the laser scanner 5 and the workpiece W1, and illustrations are omitted.

[0010] Naturally, the right-handed XYZ coordinate system shown in Figure 1 and other drawings is for the convenience of explaining the positional relationship of the components. Usually, the positive direction of the Z axis is vertically upward, and the XY plane is a horizontal plane, which is common among the drawings.

[0011] As shown in FIGS. 1 and 2, the laser welding apparatus 100 includes an upper gas supply unit 1, a lower gas supply unit 2, a protective optical member 4, and a laser scanner 5. The upper gas supply unit 1 is an upper gas supply unit, a lower gas supply unit 2 is a lower gas supply unit, a protective optical member 4, and a laser scanner 5.

[0012] The protective optical member 4 is a member made of a glass material that is transmissive to a laser. The protective optical member 4 is, for example, protective glass. The protective optical member 4 is disposed between the laser scanner 5 and the workpiece W1. The protective optical member 4 includes a plate-shaped portion 4a and a cylindrical portion 4b. The plate-shaped portion 4a is disposed below the laser scanner 5 (here, in the negative Z-axis direction).

[0013] The cylindrical portion 4b extends downward from the outer edge of the plate-like portion 4a. The cylindrical portion 4b may be a cylindrical body. The plate-like portion 4a closes the opening at the upper end of the cylindrical portion 4b. The axis Z1 of the cylindrical portion 4b passes through the center of the plate-like portion 4a.

[0014] The plate-like portion 4a and the cylindrical portion 4b may not be integral but may be separate. When the plate-like portion 4a and the cylindrical portion 4b are separate, it is preferable that the plate-like portion 4a and the cylindrical portion 4b are in close contact with each other so that gas hardly passes between the plate-like portion 4a and the cylindrical portion 4b. The cylindrical portion 4b may be made of a material that is not transparent to laser.

[0015] The upper gas supply unit 1 is provided below the plate-shaped portion 4a of the protective optical member 4. The lower gas supply unit 2 is provided below the upper gas supply unit 1. The upper gas supply unit 1 and the lower gas supply unit 2 may be disposed inside the cylindrical portion 4b of the protective optical member 4.

[0016] 1 to 3, the upper gas supply unit 1 includes a connecting pipe 1a, a flow path 1b, a plurality of first injection ports 1c, and a plurality of second injection ports 1d. In the example shown in Fig. 1, the upper gas supply unit 1 includes four connecting pipes 1a.

[0017] The connecting pipe 1a, the flow path 1b, the first nozzles 1c, and the second nozzles 1d are mutually connected. Gas can move inside the connecting pipe 1a, the flow path 1b, the first nozzles 1c, and the second nozzles 1d. For example, air or an inert gas can be used as such a gas.

[0018] The flow path 1b extends in an annular shape inside the cylindrical portion 4b. The connection pipe 1a passes through the outer circumferential surface of the cylindrical portion 4b from the flow path 1b and protrudes to the outside of the protective optical member 4. The first jet port 1c and the second jet port 1d face from the flow path 1b toward the inside of the cylindrical portion 4b. The first jet ports 1c and the second jet ports 1d are arranged along the outer edge of the plate-like portion 4a of the protective optical member 4.

[0019] 1, the first injection ports 1c and the second injection ports 1d may be alternately arranged along the outer edge of the plate-shaped portion 4a of the protective optical member 4. Alternatively, a set of two first injection ports 1c and one second injection port 1d may be continuously arranged along the outer edge of the plate-shaped portion 4a of the protective optical member 4, as shown in FIG.

[0020] The flow path 1b is supplied with gas from an external device (not shown) via a connecting pipe 1a, and the flow path 1b guides the supplied gas to a plurality of first injection ports 1c and a plurality of second injection ports 1d.

[0021] The first injection ports 1c inject the gas guided from the flow path 1b from the outer edge of the plate-shaped portion 4a of the protective optical member 4 toward the center.

[0022] The second nozzles 1d inject the gas guided from the flow path 1b downward from the outer edge of the plate-shaped portion 4a. Specifically, the second nozzles 1d inject the gas guided from the flow path 1b in a direction inclined toward the optical axis of the laser from the outer edge of the plate-shaped portion 4a.

[0023] The second nozzles 1d may inject the gas guided from the flow path 1b from the outer edge of the plate-shaped portion 4a in a direction parallel to the optical axis of the laser (here, the negative Z-axis direction). This allows the second nozzles 1d to more strongly flow the gas downward from the outer edge of the plate-shaped portion 4a. This improves the flow rate of the gas flowing downward, and further suppresses the flow of fumes toward the plate-shaped portion 4a.

[0024] The lower gas supply unit 2 includes a connecting pipe 2a, a flow path 2b, and a plurality of injection ports 2c. The connecting pipe 2a, the flow path 2b, and the plurality of injection ports 2c are mutually connected, and gas can move inside the connecting pipe 2a, the flow path 2b, and the plurality of injection ports 2c. For example, air or an inert gas can be used as such a gas.

[0025] The flow path 2b extends in the circumferential direction inside the cylindrical portion 4b. The connection pipe 2a passes through the outer circumferential surface of the cylindrical portion 4b from the flow path 2b and protrudes to the outside of the protective optical member 4. The multiple injection ports 2c open or protrude from the flow path 2b at the lower end of the cylindrical portion 4b.

[0026] The multiple injection ports 2c are arranged along the lower end of the cylindrical portion 4b of the protective optical member 4. For example, as shown in Fig. 4, the multiple injection ports 2c may be arranged at predetermined intervals along the lower end of the cylindrical portion 4b of the protective optical member 4.

[0027] The flow path 2b is supplied with gas from an external device (not shown) via the connection pipe 2a, and the flow path 2b guides the supplied gas to a plurality of injection ports 2c.

[0028] The multiple injection ports 2c inject gas downward from the lower end of the cylindrical portion 4b. Specifically, the multiple injection ports 2c may inject gas downward from the lower end of the cylindrical portion 4b toward the axis Z1 side of the cylindrical portion 4b. The total area of ​​the openings of the multiple injection ports 2c may be small.

[0029] The cylindrical portion 4b has a plurality of, for example, 44, gas inlets 3. The plurality of gas inlets 3 are provided between the upper gas supply unit 1 and the lower gas supply unit 2. The plurality of gas inlets 3 may be arranged at intervals in the circumferential direction of the cylindrical portion 4b. The plurality of gas inlets 3 penetrate the cylindrical portion 4b.

[0030] The gas can move from the outside of the cylindrical portion 4b to the inside of the cylindrical portion 4b through the gas inlet ports 3. In other words, the gas can be introduced from the outside of the cylindrical portion 4b to the inside of the cylindrical portion 4b through the gas inlet ports 3. Such a gas is a welding atmosphere, for example, air or an inert gas.

[0031] The laser scanner 5 is disposed above the protective optical member 4 so as to be able to irradiate the workpiece W1 with a laser passing through the plate-shaped portion 4a.

[0032] Next, a laser welding method using the laser welding device 100 according to this embodiment will be described. The laser scanner 5 emits a laser toward the workpiece W1 while the first nozzles 1c, the second nozzles 1d, and the nozzles 2c inject air as a gas. The emitted laser passes through the center of the plate-shaped portion 4a of the protective optical member 4, travels along the axis Z1 of the cylindrical portion 4b, and irradiates the workpiece W1. A part of the workpiece W1 melts, and welding is performed. This melting generates fumes.

[0033] In contrast, in this embodiment, the first injection ports 1c inject gas from the outer edge of the plate-shaped portion 4a to the center, so that the lower surface of the plate-shaped portion 4a is covered with gas, and the gas gathers at the center of the plate-shaped portion 4a and flows downward of the plate-shaped portion 4a. This makes it possible to prevent fumes from approaching the plate-shaped portion 4a.

[0034] In this embodiment, the area of ​​the first injection port 1c is larger than that of the second injection port 1d. For example, the ratio of the area of ​​the first injection port 1c to that of the second injection port 1d is set to about 2.7:1. This increases the flow rate of the gas on the lower surface of the plate-like portion 4a, and more effectively prevents the fumes from approaching the plate-like portion 4a.

[0035] Furthermore, in this embodiment, the first injection port 1c not only injects the gas guided from the flow path 1b from the outer edge of the plate-shaped portion 4a of the protective optical member 4 toward the center, but also the injection direction of the first injection port 1c is inclined with respect to the radial direction of the cylindrical portion 4b. This inclination angle is set to about 5°, for example, as shown in Fig. 1. This can promote the swirling flow as shown in Fig. 5, increase the flow rate of the gas flowing downward to the plate-shaped portion 4a, and further suppress the flow of fumes toward the plate-shaped portion 4a.

[0036] Furthermore, in this embodiment, the multiple second injection ports 1d inject gas downward from the outer edge of the plate-like portion 4a, and at the same time, the multiple injection ports 2c inject gas downward from the lower end of the cylindrical portion 4b. In addition, the multiple gas inlet ports 3 introduce gas from the outside to the inside of the cylindrical portion 4b, rectifying the airflow downward. As a result, more gas is allowed to flow downward, and the flow of fumes toward the plate-like portion 4a can be further suppressed.

[0037] As described above, according to this embodiment, it is possible to suppress adhesion of fumes to the protective optical member 4. Furthermore, by preventing adhesion of fumes to the protective optical member 4, it is possible to ensure welding quality.

[0038] Next, experimental results using the laser welding apparatus 100 according to this embodiment will be described. FIG. 6 is a diagram showing experimental results using the laser welding apparatus according to this embodiment. In this experiment, the configuration according to this embodiment described above is compared with the configuration of the mass-produced shape. Note that in the configuration of the mass-produced shape, the upper gas supply unit is provided with downwardly slanting jet nozzles corresponding to the first and second jet nozzles 1c and 1d of this embodiment, and the gas inlet port 3 of this embodiment is not provided, which is a difference between the configuration of the mass-produced shape and the configuration of this embodiment.

[0039] In this experiment, the following experiments (I) and (II) were carried out to compare the configuration of this embodiment with the configuration of a mass-produced shape.

[0040] (I) Air is sent through the connecting pipe 1a of the upper gas supply unit 1 and the connecting pipe 2a of the lower gas supply unit 2, and the flow rate of the air is measured below the protective optical member 4. The flow rate is measured (a) directly below the injection port 2c of the lower gas supply unit 2, at eight locations ((1) to (8)) that are approximately equally spaced in the circumferential direction of the lower end of the cylindrical portion 4b of the protective optical member 4, and (b) at a position 100 mm away from the lower end of the cylindrical portion 4b of the protective optical member 4 and at the circumferential center of the lower end of the cylindrical portion 4b.

[0041] Fig. 6(a) shows the flow velocities of the configuration of this embodiment and the configuration of the mass-produced shape at the measurement position of (a) above. The solid line (thick line) shows the flow velocity of the configuration of this embodiment, and the dotted line shows the flow velocity of the configuration of the mass-produced shape. As shown in Fig. 6(a) from the results of this experiment, it can be seen that the flow velocity directly below the nozzle 2c of the lower gas supply unit 2 is increased by an average of 1.2 m / s (34%) in the configuration of this embodiment compared to the configuration of the mass-produced shape.

[0042] Fig. 6(b) shows the flow velocities of the configuration of this embodiment and the configuration of the mass-produced shape at the measurement position of (b) above. The right side shows the flow velocity of the configuration of this embodiment, and the left side shows the flow velocity of the configuration of the mass-produced shape. As a result of this experiment, as shown in Fig. 6(b), it is found that the flow velocity at a position 100 mm away from the lower end of the cylindrical portion 4b of the protective optical member 4 and at the circumferential center of the lower end is increased by 3.4 m / s (69%) in the configuration of this embodiment compared to the configuration of the mass-produced shape.

[0043] From the above experimental results, it can be confirmed that the configuration of this embodiment can increase the flow rate of gas flowing downward of the plate-shaped portion 4a of the protective optical member 4, thereby suppressing fumes from flowing toward the plate-shaped portion 4a.

[0044] (II) After welding approximately 50,000 points using the laser welding apparatus 100 according to this embodiment, the amount of increase in FS (Focus Shift) of the laser scanner 5 is measured. Note that if fumes adhere to the protective optical member 4, the temperature of the protective optical member 4 increases due to irradiation by the laser scanner 5. This causes the protective optical member 4 to expand, resulting in a FS (Focus Shift). Therefore, by measuring the amount of increase in FS, the amount of fumes adhering to the protective optical member 4 can be quantitatively evaluated.

[0045] 6(c) is a diagram showing the amount of increase in FS in the configuration of this embodiment and the configuration of the mass-produced shape. The left side shows the amount of increase in FS in the configuration of the mass-produced shape, the center shows the amount of increase in FS in the configuration of this embodiment, and the right side shows the amount of increase in FS in the configuration of this embodiment when the air flow rate is reduced to 1 / 4.

[0046] 6(c), the results of this experiment confirm that the amount of FS rise is reduced by 50 mm (88%) in the configuration of this embodiment (center) compared to the mass-produced configuration (left side). Therefore, it can be confirmed that the configuration of this embodiment (center) is an advantageous configuration in that it can suppress the amount of FS rise to a smaller amount compared to the mass-produced configuration (left side), thereby reducing the amount of fumes adhering to the protective optical member 4.

[0047] It can also be seen that the configuration of this embodiment (right side) in which the air flow rate is reduced to 1 / 4 also reduces the amount of FS rise by 36 mm (63%) compared to the mass-produced configuration (left side). Therefore, it can be seen that the configuration of this embodiment (right side) in which the air flow rate is reduced also reduces the amount of FS rise, compared to the mass-produced configuration (left side), and is therefore an advantageous configuration in which the amount of fumes adhering to the protective optical member 4 is reduced. In this way, with the configuration of this embodiment, even if the air flow rate is reduced, the effect of reducing the amount of fumes adhering to the protective optical member 4 is maintained, and further, the effects of reducing CO2 due to reduced air consumption and improving the life of the protective optical member 4 due to improved welding quality can be expected.

[0048] Although some embodiments of the present disclosure have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0049] 100 Laser welding equipment 1 Upper gas supply unit 1a Connecting pipe 1b Flow path 1c First Jet 1d Second nozzle 1e Third Jet 2 Lower gas supply unit 2a connecting pipe 2b Flow path 2c injection port 3 Gas inlet 4 Protective optical components 4a Plate-shaped part 4b Cylindrical part 5. Laser Scanner W1 Work Z1 (of the cylindrical portion 4b) axis

Claims

1. A laser scanner; A laser welding apparatus including a protective optical member disposed between the laser scanner and a workpiece, An upper gas supply unit; a lower gas supply unit provided below the upper gas supply unit, the protective optical member includes a plate-shaped portion and a cylindrical portion extending downward from an outer edge of the plate-shaped portion, the upper gas supply unit is provided below the plate-shaped portion of the protective optical member, the upper gas supply unit includes a plurality of first injection ports that inject gas toward a center of the plate-shaped portion and a plurality of second injection ports that inject gas toward a lower side of the plate-shaped portion; the cylindrical portion is provided between the upper gas supply unit and the lower gas supply unit, and has a plurality of gas inlet ports for introducing gas from an outside to an inside of the cylindrical portion; the lower gas supply unit includes a plurality of lower injection ports configured to inject gas downward from a lower end of the cylindrical portion, The area of ​​the first injection port is larger than the area of ​​the second injection port, The injection direction of the first injection port is inclined with respect to the radial direction of the cylindrical portion. Laser welding equipment.

2. 2. The laser welding device according to claim 1, wherein a ratio of an area of ​​the first jet nozzle to an area of ​​the second jet nozzle is set to 2.7:

1.

3. 2. The laser welding device according to claim 1, wherein an inclination angle of the jet direction of the first jet nozzle is set to 5 degrees.

4. The plurality of second injection ports include Gas is injected in a direction inclined toward the optical axis of the laser from the outer edge of the plate-shaped portion, or The laser welding device according to claim 1 , wherein the gas is jetted from an outer edge of the plate-shaped portion in a direction parallel to an optical axis of the laser.

5. A laser scanner; a protective optical member disposed between the laser scanner and the workpiece and having a plate-shaped portion and a cylindrical portion extending downward from an outer edge of the plate-shaped portion; an upper gas supply unit provided below the plate-like portion of the protective optical member, the upper gas supply unit having a plurality of first injection ports for injecting gas toward a center of the plate-like portion and a plurality of second injection ports for injecting gas toward a lower side of the plate-like portion; a lower gas supply unit provided below the upper gas supply unit; A laser welding method for a laser welding apparatus comprising: a plurality of gas inlet ports of the cylindrical portion provided between the upper gas supply unit and the lower gas supply unit introduce gas from the outside to the inside of the cylindrical portion; a plurality of lower injection ports of the lower gas supply unit inject gas downward from a lower end of the cylindrical portion; The first jet port having a larger jet port area than the second jet port injects gas in a jet direction inclined with respect to a radial direction of the cylindrical portion. Laser welding method using a laser welding device.

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