Laser machining device

Abstract

The present invention provides a laser machining device comprising: a first laser light source that generates first laser light having a wavelength of 900-1100 nm; a second laser light source that generates second laser light having a wavelength shorter than or equal to the wavelength of the first laser light; a light source control unit that controls the oscillation and output of each laser light source; a first lens mechanism that controls the focal point position of the first laser light; a second lens mechanism that controls the focal point position of the second laser light; a first deflection mechanism capable of changing an irradiation position through use of the first laser light; a second deflection mechanism capable of changing an irradiation position through use of with the second laser light; and a scanner control unit that controls operations of the first lens mechanism and the second lens mechanism and operations of the first deflection mechanism and the second deflection mechanism, wherein the scanner control unit can change the relative positions of a center of a first beam shape of the first laser light and a center of a second beam shape of the second laser light on a workpiece by controlling the first deflection mechanism and the second deflection mechanism individually while causing the first deflection mechanism and the second deflection mechanism to cooperatively operate.

Description

Laser Processing Equipment

[0001] The present disclosure relates to a laser processing apparatus.

[0002] Conventionally, laser processing devices have been known that irradiate a processing location on a workpiece with a laser beam to perform processing such as welding (see, for example, Patent Document 1). When such laser processing devices perform metal welding, particularly copper welding, using a high-power laser beam, problems such as scattering of spatter (molten metal droplets) and the formation of porosity (defects) within the weld bead have been encountered. These problems are due to the instability of the molten pool formed on the workpiece by laser irradiation.

[0003] To stabilize the molten pool, a conventional technique involves coaxially superimposing blue and green laser beams with wavelengths of 400 to 550 nm on top of near-infrared laser beams with wavelengths of 900 to 1100 nm used for welding. Copper has a high light absorption rate in the 400 to 550 nm wavelength range. Therefore, the beam diameter of the blue and green laser beams is made larger than that of the near-infrared laser beam, and the beams are coaxially superimposed. This allows the blue and green laser beams to be irradiated onto the workpiece to be processed prior to the near-infrared laser beam, thereby preheating the workpiece and controlling the shape of the molten pool and stabilizing it.

[0004] Japanese Patent Application Laid-Open No. 2014-024105

[0005] In the above-mentioned method, two laser beams of different wavelengths are superimposed on the same axis and irradiated. Therefore, it is not possible to change the beam shape of one of the laser beams irradiated on the workpiece or the relative positions of the two laser beams during processing. As a result, it is not possible to sufficiently stabilize the molten pool, and problems such as the scattering of spatter (molten metal droplets) and the formation of porosity (defects) inside the weld bead remain unresolved.

[0006] Therefore, it is desired to provide a laser processing device that can stabilize the molten pool.

[0007] The laser processing apparatus of the present disclosure includes a first laser light source that generates a first laser light having a wavelength of 900 to 1100 nm, a second laser light source that generates a second laser light having a wavelength equal to or shorter than that of the first laser light, a light source control unit that controls oscillation and output of the first laser light source and the second laser light source, a first lens mechanism that controls the focal position of the first laser light, a second lens mechanism that controls the focal position of the second laser light, a first deflection mechanism that has at least one mirror that can reflect the first laser light and can change the irradiation position of the first laser light, and a second laser light source that deflects the second laser light. The laser processing device comprises a second deflection mechanism having at least one reflective mirror and capable of changing the irradiation position of the second laser light, and a scanner control unit that controls the operation of the first lens mechanism and the second lens mechanism and the operation of the first deflection mechanism and the second deflection mechanism, wherein the scanner control unit controls the first deflection mechanism and the second deflection mechanism individually while causing them to operate in coordination, thereby changing the relative position between the center of the first beam shape of the first laser light and the center of the second beam shape of the second laser light on a workpiece that is the object to be processed.

[0008] 5A is a diagram illustrating the configuration of a laser processing apparatus according to a first embodiment; FIG. 5B is a diagram illustrating a first beam shape, a second beam shape, and a molten pool on the surface of a workpiece irradiated with a first laser beam and a second laser beam by the laser processing apparatus according to the first embodiment; FIG. 5C is a diagram illustrating beam superposition in a conventional laser processing apparatus; FIG. 5D is a diagram illustrating a first beam shape, a second beam shape, and a molten pool on the surface of a workpiece irradiated with a first laser beam and a second laser beam by the conventional laser processing apparatus; FIG. 5E is a diagram illustrating a state in which the focal positions of the first laser beam and the second laser beam are the surface of the workpiece in the optical axis direction (Z direction); FIG. 5F is a diagram illustrating a first beam shape B1, a second beam shape B2, and a molten pool M on the surface of the workpiece at the focal position shown in FIG. 5A; FIG. 5G is a diagram illustrating a state in which the focal position of the first laser beam is the surface of the workpiece, and the focal position of the second laser beam is a predetermined distance on the +Z side from the surface of the workpiece; FIG. 6A is a diagram illustrating a laser processing apparatus according to a second embodiment; FIG. 6H is a diagram illustrating a first processing head and an OCT system of a laser processing apparatus according to a third embodiment; 10 is a diagram showing the first beam shape, the second beam shape, and the state of the molten pool on the surface of the workpiece when the first laser beam is oscillated in the direction of the arrow d. FIG.

[0009] Hereinafter, an embodiment of a laser processing apparatus according to the present disclosure will be described with reference to the drawings, etc. Note that the drawings shown below, including Fig. 1, are schematic diagrams, and the size and shape of each part are appropriately exaggerated to facilitate understanding.

[0010] The numerical values ​​of the dimensions of each member and the names of materials described in this specification are examples of embodiments and are not limited to these, and may be selected and used as appropriate. Furthermore, in this specification, terms specifying shapes and geometric conditions, such as parallel and orthogonal, are intended to include not only their strict meanings but also states with an error that can be considered parallel or orthogonal.

[0011] (First embodiment) Fig. 1 is a diagram illustrating the configuration of a laser processing apparatus 1 according to a first embodiment. The laser processing apparatus 1 shown in Fig. 1 performs welding by irradiating a workpiece W, which is an object to be processed and is placed on a stage (not shown), with laser beams of two different wavelengths.

[0012] In Figure 1 and the figures shown below, an XYZ Cartesian coordinate system is provided as appropriate. The XY plane is parallel to the plane of the stage, and the direction perpendicular to the plane of the stage is the Z direction. The X direction is parallel to the main scanning direction of the beam for welding processing, and its traveling direction is the +X side. The Y direction is a direction perpendicular to the X direction, and in Figure 1, the back side of the paper is the +Y side. The Z direction is a direction perpendicular to the plane of the stage, and the upper side in the vertical direction is the +Z side.

[0013] The laser processing apparatus 1 includes a first laser light source 11, a second laser light source 12, a processing head 20, a robot 81, and a control device 70. In this embodiment, the workpiece W to be welded by the laser processing apparatus 1 will be described as being made of copper and copper alloy.

[0014] The first laser light source 11 and the second laser light source 12 internally oscillate and generate laser light in response to commands from a light source control unit 71 of the control device 70. In this embodiment, the first laser light source 11 generates a first laser light L1, which is a near-infrared laser light with a wavelength of 900 to 1100 nm. The second laser light source 12 generates a second laser light L2, whose wavelength is shorter than or equal to that of the first laser light L1. In this embodiment, the second laser light L2 is a blue to green laser light with a wavelength of 400 to 550 nm. In FIG. 1 and the figures shown below, the first laser light L1 is indicated by a solid line, and the second laser light L2 is indicated by a dashed line.

[0015] The first laser beam L1 is a main laser beam used for welding. The second laser beam L2 is a laser beam in a wavelength range that has a high optical absorption rate in copper, and has the function of preheating the workpiece W by being irradiated with the workpiece W prior to the first laser beam L1.

[0016] The first laser light source 11 and the second laser light source 12 are a direct diode laser (DDL) oscillator, a CO ２ A laser oscillator, a solid-state laser (YAG laser) oscillator, etc. may be appropriately selected and used. The first laser light source 11 and the second laser light source 12 supply the generated laser beams to the processing head 20.

[0017] The processing head 20 includes a first lens mechanism 21 and a mirror 25 corresponding to the first laser light L1, a first deflection mechanism 30, a second lens mechanism 23 and a mirror 26 corresponding to the second laser light L2, and a second deflection mechanism 40. The processing head 20 includes, within its housing, two galvanometer scanners made of optical components corresponding to the two laser lights, respectively.

[0018] In this embodiment, the machining head 20 is attached to a robot 81. The machining head 20 can be moved by the robot 81 to change the irradiation positions of the first laser light L1 and the second laser light L2 on the workpiece W.

[0019] The first lens mechanism 21 includes a lens 22 that is capable of transmitting the first laser light L1 having a wavelength of 900 to 1100 nm, and a drive mechanism (not shown) that supports and moves the position of the lens 22. The first lens mechanism 21 is capable of moving the position of the lens 22 in the optical axis direction of the first laser light L1 by means of the drive mechanism (not shown) in response to a command from the scanner control unit 72 of the control device 70. Changing the position of the lens 22 in the optical axis direction of the first laser light L1 changes the focal position of the first laser light L1 in the optical axis direction.

[0020] Similarly, the second lens mechanism 23 includes a lens 24 that transmits the second laser light L2 and a drive mechanism (not shown) that supports and moves the position of the lens 24. The second lens mechanism 23 can move the position of the lens 24 in the optical axis direction of the second laser light L2 by means of the drive mechanism (not shown) in response to a command from the scanner control unit 72 of the control device 70. Changing the position of the lens 24 in the optical axis direction of the second laser light L2 changes the focal position of the second laser light L2 in the optical axis direction.

[0021] In order to adjust the focal position of the first laser light L1, a lens (not shown) may be arranged on the optical axis of the first laser light L1 in addition to the lens 22. Similarly, in order to adjust the focal position of the second laser light L2, a lens (not shown) may be arranged on the optical axis of the second laser light L2 in addition to the lens 24. These lenses (not shown) may be movable in the optical axis direction of each laser light, or may be fixed at predetermined positions.

[0022] The mirror 25 is a mirror capable of reflecting the first laser light L1, which is a near-infrared laser light with a wavelength of 900 to 1100 nm. The first laser light L1 supplied from the first laser light source 11 passes through the lens 22, is reflected by the mirror 25, and is supplied to the first deflection mechanism 30. The mirror 26 is a mirror capable of reflecting the second laser light L2, which has a wavelength of 400 to 550 nm. The second laser light L2 supplied from the second laser light source 12 passes through the lens 24, is reflected by the mirror 26, and is supplied to the second deflection mechanism 40.

[0023] The first deflection mechanism 30 is a mechanism that adjusts the irradiation position and irradiation angle of the first laser light L1 relative to the workpiece W. The first deflection mechanism 30 includes mirrors 31 and 32. The mirrors 31 and 32 are optical components that can reflect the first laser light L1. The first deflection mechanism 30 also includes a drive mechanism (not shown) that rotates the mirrors 31 and 32 around their respective rotation axes.

[0024] Based on a command from the scanner control unit 72 of the control device 70, the first deflection mechanism 30 controls the rotation angles of the mirrors 31, 32 using each drive mechanism so that the irradiation position of the first laser light L1 on the workpiece W is at predetermined coordinates. This causes the first laser light L1 to scan a two-dimensional space on the workpiece W. The first deflection mechanism 30 can also adjust the irradiation angle of the first laser light L1 on the workpiece W based on a command from the scanner control unit 72.

[0025] The second deflection mechanism 40 is a mechanism that adjusts the irradiation position and irradiation angle of the second laser light L2 relative to the workpiece W. The second deflection mechanism 40 includes mirrors 41 and 42. The mirrors 41 and 42 are optical components that can reflect the second laser light L2. The second deflection mechanism 40 also includes a drive mechanism (not shown) that rotates the mirrors 41 and 42 around their respective rotation axes.

[0026] Based on a command from the scanner control unit 72 of the control device 70, the second deflection mechanism 40 controls the rotation angles of the mirrors 41, 42 using the respective drive mechanisms so that the irradiation position of the second laser light L2 on the workpiece W is at predetermined coordinates. This causes the second laser light L2 to scan a two-dimensional space on the workpiece W. Furthermore, based on a command from the scanner control unit 72, the second deflection mechanism 40 can also adjust the irradiation angle of the second laser light L2 on the workpiece W.

[0027] As described above, mirror 25 and mirrors 31 and 32 are mirrors corresponding to first laser light L1 and reflect light with wavelengths of 900 to 1100 nm, while mirror 26 and mirrors 41 and 42 are mirrors corresponding to second laser light L2 and reflect light with wavelengths of 400 to 550 nm.

[0028] These mirrors are made of, for example, a metal film or a dielectric multilayer film formed on the surface of a substrate to form a reflective surface. As the metal film, a vapor-deposited film of aluminum, copper, or gold is suitable. As the high refractive index layer of the dielectric multilayer film, titanium oxide (TiO ２ ) and tantalum oxide (Ta ２ O ３ ) is used as the low refractive index layer, and silicon oxide (SiO ２ ), magnesium fluoride (MgF ２ ) and the like are used as the substrate. Aluminum and silicon oxide (SiO ２ ), silicon carbide (SiC), etc. The material and film thickness of each of these members are appropriately selected depending on the wavelength of the laser light to be reflected.

[0029] The robot 81 is a mechanism that supports the machining head 20. The robot 81 can freely change the position of the machining head 20 relative to the workpiece W in response to a command from the robot control unit 73 of the control device 70. The robot 81 can move the machining head 20 even during welding processing.

[0030] The control device 70 is a control unit that controls the operations of the first laser light source 11 and the second laser light source 12, the first deflection mechanism 30 and the second deflection mechanism 40 in the processing head 20, and the first lens mechanism 21 and the second lens mechanism 23. The control device 70 includes a light source control unit 71, a scanner control unit 72, a robot control unit 73, etc. The control device 70 is configured using a computer that includes memories such as a read-only memory (ROM) and a random access memory (RAM), a central processing unit (CPU), a communication control unit, etc. The control device 70 executes various functions in cooperation with each piece of hardware by appropriately reading and executing an operating system (OS) and various application programs stored in an internal memory or an external memory.

[0031] The light source control unit 71 controls the operations of the first laser light source 11 and the second laser light source 12. The light source control unit 71 issues commands to each of the first laser light source 11 and the second laser light source 12 to cause or stop the oscillation of the first laser light L1 and the second laser light L2. The light source control unit 71 can also individually control the outputs of the first laser light source 11 and the second laser light source 12, and individually adjust the intensities of the first laser light L1 and the second laser light L2.

[0032] The scanner control unit 72 issues commands to the driving mechanism of the mirrors 31 and 32 of the first deflection mechanism 30 and the driving mechanism of the mirrors 41 and 42 of the second deflection mechanism 40, and adjusts the rotation angle of each mirror, thereby controlling the irradiation position of the first laser light L1 and the second laser light L2 on the workpiece W (the relative position between the irradiation position of the first laser light L1 and the irradiation position of the second laser light L2) and the irradiation angle of each laser light.

[0033] In addition, the scanner control unit 72 issues commands to the first lens mechanism 21 and the second lens mechanism 23, adjusts the positions of the lenses 22 and 24 in the optical axis direction using each driving mechanism (not shown), and controls the focal position of each laser light in the optical axis direction.

[0034] The scanner control unit 72 can set in advance conditions related to processing conditions according to information such as the material and thickness of the workpiece W, i.e., conditions related to the outputs of the first laser light source 11 and the second laser light source 12, the relative positions of the irradiation positions of the first laser light L1 and the second laser light L2 (the relative positions of the center t1 of the first beam shape B1 and the center t2 of the second beam shape B2, which will be described later), and the focal positions in the optical axis direction of the first laser light L1 and the second laser light L2, and store these conditions in a memory (not shown) in the control device 70 or a memory (not shown) in the scanner control unit 72. The scanner control unit 72 can also call up these conditions as needed and perform control according to each condition.

[0035] The robot control unit 73 controls the position of the robot 81. The robot control unit 73 issues a command to the robot 81 to move the processing head 20 supported by the robot 81 relative to the workpiece W so that the processing head 20 is positioned at a position suitable for welding processing.

[0036] Here, the irradiation of laser light in the laser processing apparatus 1 will be described. In response to a command from the light source control unit 71 of the control device 70, the first laser light L1 emitted from the first laser light source 11 passes through the lens 22 of the first lens mechanism 21 in the processing head 20, is reflected by a mirror 25, and is sweep-irradiated onto the surface of the workpiece W by the first deflection mechanism 30. Similarly, the second laser light L2 emitted from the second laser light source 12 in response to a command from the control device 70 passes through the lens 24 of the second lens mechanism 23 in the processing head 20, is reflected by a mirror 26, and is sweep-irradiated onto the surface of the workpiece W by the second deflection mechanism 40. The irradiation of the first laser light L1 and the irradiation of the second laser light L2 are performed simultaneously.

[0037] 2 is a diagram showing the first beam shape B1, the second beam shape B2, and the molten pool M on the surface of the workpiece W irradiated with the first laser beam L1 and the second laser beam L2 by the laser processing device 1 of the first embodiment. In FIG. 2, an example will be described in which the first beam shape B1, the second beam shape B2, and the molten pool M are all circular.

[0038] The scanner control unit 72 individually controls the first deflection mechanism 30 and the second deflection mechanism 40 while causing them to operate in coordination, thereby appropriately changing the relative position of the center t1 of the first beam shape B1 of the first laser light L1 and the center t2 of the second beam shape B2 of the second laser light L2 on the workpiece W. Therefore, the laser processing apparatus 1 can scan the workpiece W so that the second beam shape B2 precedes the first beam shape B1, or so that the first beam shape B1 lags behind the second beam shape B2, for example, as shown in FIG.

[0039] FIG. 3 is a diagram illustrating beam superposition in a conventional laser processing apparatus 1B. FIG. 4 is a diagram illustrating the first beam shape B1, the second beam shape B2, and the molten pool M on the surface of a workpiece W irradiated with the first laser beam L1 and the second laser beam L2 by the conventional laser processing apparatus 1B. FIG. 3 illustrates the coaxial superposition of the first laser beam L1 and the second laser beam L2 in the conventional laser processing apparatus 1B. Note that in the conventional laser processing apparatus 1B shown in FIG. 3, the first laser beam L1 and the second laser beam L2 are irradiated coaxially, but the two beams are shown separated for ease of understanding. Also, in FIG. 4, an example will be described in which the first beam shape B1, the second beam shape B2, and the molten pool M are all circular.

[0040] The conventional laser processing apparatus 1B includes a first laser light source 11, a second laser light source 12, lenses 210, 220, and 240, and a mirror 230. The lens 210 transmits the first laser light L1, and the lens 220 transmits the second laser light L2. The lens 240 transmits the first laser light L1 and the second laser light L2. The mirror 230 has a function of transmitting the first laser light L1 and reflecting the second laser light L2.

[0041] In the conventional laser processing apparatus 1B, the first laser beam L1 and the second laser beam L2 are emitted from the respective laser light sources and, as shown in FIG. 3, are passed through lenses 210, 220, 240 and a mirror 230, and are then coaxially superimposed and irradiated onto the workpiece W. Therefore, in the conventional laser processing apparatus 1B, for example, as shown in FIG. 4, the center t1 of the first beam shape B1 of the first laser beam L1 and the center t2 of the second beam shape B2 of the second laser beam L2 coincide on the surface of the workpiece W. Furthermore, in order to preheat the workpiece W, the second laser beam L2 needs to be irradiated onto the workpiece W prior to the first laser beam L1. Therefore, in the conventional laser processing apparatus 1B, the second beam shape B2 is set to be larger than the first beam shape B1.

[0042] With this conventional laser processing device 1B, it is possible to change the intensity of each laser beam during processing, but it is not possible to change the relative position between the first beam shape B1 and the second beam shape B2, or to change the size or shape of one of the beam shapes.

[0043] In contrast, in the laser processing device 1 of this embodiment, the first laser beam L1 and the second laser beam L2 are each irradiated onto the surface of the workpiece W by a different deflection mechanism corresponding to each laser beam. At this time, each deflection mechanism operates cooperatively under the control of the scanner control unit 72. As a result, the laser processing device 1 of this embodiment can change the relative position and shape of the beam shapes of the two laser beams (the angle of incidence of each laser beam on the workpiece W) while the two laser beams scan along the same path.

[0044] 2, the laser processing apparatus 1 can control the first deflection mechanism 30 and the second deflection mechanism 40 in response to a command from the scanner control unit 72 to sweep-irradiate the workpiece W with the center t2 of the second beam shape B2 of the second laser beam L2 positioned a predetermined distance forward (on the +X side) of the center t1 of the first beam shape B1 of the first laser beam L1. The laser processing apparatus 1 can also appropriately set the distance between the centers t1 and t2 depending on the thickness of the workpiece W, etc. Furthermore, the laser processing apparatus 1 can appropriately change the relative positions of the center t1 of the first beam shape B1 and the center t2 of the second beam shape B2 to achieve suitable processing conditions while causing the two laser beams to scan the same path during welding.

[0045] 4, the laser processing device 1 of this embodiment can also superimpose two coaxial laser beams as in the conventional case and irradiate the workpiece W with them. Furthermore, the laser processing device 1 of this embodiment can adjust the output of each laser light source individually, and can also adjust the intensity of each laser beam individually.

[0046] Furthermore, the laser processing apparatus 1 can change the size of the beam shape by changing the focal positions of the two laser beams. Figures 5A, 5B, 6A, and 6B show the relationship between the focal positions of each laser beam and the diameter of the beam shape. Figure 5A is a diagram showing the focal positions F1 and F2 of the first laser beam L1 and the second laser beam L2 on the surface of the workpiece W in the optical axis direction (Z direction). Figure 5B is a diagram showing the first beam shape B1, the second beam shape B2, and the molten pool M on the surface of the workpiece W at the focal positions shown in Figure 5A. Figure 6A is a diagram showing the focal position F1 of the first laser beam L1 on the surface of the workpiece W and the focal position F2 of the second laser beam L2 a predetermined distance to the +Z side of the surface of the workpiece W. Figure 6B is a diagram showing the first beam shape B1, the second beam shape B2, and the molten pool M on the surface of the workpiece W at the focal positions shown in Figure 6A. 5B and 6B, an example will be described in which the first beam shape B1, the second beam shape B2, and the molten pool M are all circular.

[0047] As shown in FIGS. 5A and 5B , when the focal positions F1 and F2 of the two laser beams are both located on the surface of the workpiece W, the diameters of the first beam shape B1 and the second beam shape B2 are assumed to be equal. If it is desired to preheat a wider area of ​​the workpiece W with the second laser beam L2 due to various welding conditions, the scanner control unit 72 commands the lens 24 of the second lens mechanism 23 to move the focal position F2 of the second laser beam L2. Here, the scanner control unit 72 controls the second lens mechanism 23 to move the focal position F2 a predetermined distance toward the +Z side. As a result, the laser processing apparatus 1 can increase the diameter of the second beam shape B2 while maintaining the relative positions of the center t1 of the first beam shape B1 and the center t2 of the second beam shape B2, as shown in FIGS. 6A and 6B . This allows the laser processing apparatus 1 to expand the preheating area of ​​the workpiece W with the second laser beam L2 and stabilize the molten pool M.

[0048] It is also possible to change the focal position F1 in the optical axis direction of the first laser light L1 in response to a command from the scanner control unit 72, thereby controlling the diameter of the first beam shape B1 on the workpiece W. In this case, the laser processing device 1 can control the shape and size of the molten pool M, thereby stabilizing the molten pool M.

[0049] Furthermore, the laser processing device 1 can use each deflection mechanism to adjust the angle of incidence of each laser beam with respect to the workpiece W. Therefore, for example, it is possible to control one of the deflection mechanisms using the scanner control unit 72 and change the angle of incidence of the laser beam corresponding to that deflection mechanism, thereby making the beam shape elliptical or the like.

[0050] As described above, the laser processing apparatus 1 of this embodiment can individually adjust, even during welding, the relative position between the center t1 of the first beam shape B1 of the first laser beam L1 and the center t2 of the second beam shape B2 of the second laser beam L2, the size and shape of each beam shape, the intensity of each laser beam, etc. This allows the laser processing apparatus 1 to efficiently preheat the workpiece W, improve the stability of the molten pool M formed on the surface of the workpiece W, suppress the scattering of spatter and the formation of porosity inside the weld bead, and improve the quality of the weld.

[0051] Furthermore, in the conventional laser processing apparatus 1B, in order to irradiate two laser beams of different wavelengths coaxially superimposed on one another, optical components equipped with a reflective film or coating that simultaneously reflects or transmits light of multiple wavelength ranges, such as the mirror 230 and lens 240 shown in FIG. 3, are required. However, such optical components are expensive, which increases the production cost of the laser processing apparatus. In contrast, in the laser processing apparatus 1 of this embodiment, each deflection mechanism and the like are composed only of optical components equipped with a reflective film or coating corresponding to the wavelength range of one laser beam, and can be constructed inexpensively.

[0052] 7 is a diagram illustrating a laser processing apparatus 2 according to a second embodiment. The laser processing apparatus 2 according to the second embodiment differs from the first embodiment in that each laser beam is irradiated onto the workpiece W from an individual processing head, but otherwise has a similar configuration. Therefore, parts that perform the same functions as those in the first embodiment described above are given the same reference numerals, and duplicated descriptions will be omitted as appropriate.

[0053] The laser processing device 2 of this embodiment includes a first laser light source 11, a second laser light source 12, a first processing head 50, a second processing head 60, robots 82, 83, and a control device 70.

[0054] The first machining head 50 includes a first lens mechanism 51 and a mirror 53 for supplying the first laser beam L1 to the first deflection mechanism 30, and the first deflection mechanism 30. The first machining head 50 is a galvanometer scanner. The first machining head 50 is attached to a robot 82, and its position relative to the workpiece W can be changed by movement by the robot 82.

[0055] The second processing head 60 includes a second lens mechanism 61 and a mirror 63 for supplying the second laser light L2 to the second deflection mechanism 40, and the second deflection mechanism 40. This second processing head 60 is a galvanometer scanner, similar to the first processing head 50. In addition, the second processing head 60 is attached to a robot 83, and its position relative to the workpiece W can be changed by movement by the robot 83.

[0056] The robot control unit 73 controls the positions of the robots 82, 83 relative to the workpiece W. The robot control unit 73 issues commands to the robots 82, 83, and can freely move the positions of the first machining head 50 and the second machining head 60 relative to the workpiece W.

[0057] The first lens mechanism 51 corresponds to the first lens mechanism 21 in the first embodiment, and the lens 52 corresponds to the lens 22. The mirror 53 corresponds to the mirror 25. Similarly, the second lens mechanism 61 corresponds to the second lens mechanism 23 in the first embodiment, and the lens 62 corresponds to the lens 24. The mirror 63 corresponds to the mirror 26.

[0058] In the laser processing device 2 of this embodiment, the first laser light L1 emitted from the first laser light source 11 in response to a command from the light source control unit 71 of the control device 70 passes through the lens 52 and mirror 53 of the first lens mechanism 51 located in the first processing head 50, enters the first deflection mechanism 30, and is swept and irradiated onto the workpiece W by the first deflection mechanism 30. In addition, the second laser light L2 emitted from the second laser light source 12 in response to a command from the light source control unit 71 of the control device 70 passes through the lens 62 and mirror 63 of the second lens mechanism 61 located in the second processing head 60, enters the second deflection mechanism 40, and is swept and irradiated onto the workpiece W by the second deflection mechanism 40.

[0059] As in the first embodiment, the first laser beam L1 and the second laser beam L2 are simultaneously irradiated onto the workpiece W. The scanner control unit 72 controls the first deflection mechanism 30 and the second deflection mechanism 40 to adjust the irradiation positions of the first laser beam L1 and the second laser beam L2 on the workpiece W, etc.

[0060] According to this embodiment, as in the first embodiment, the laser processing apparatus 2 can individually adjust the relative positions of the first beam shape B1 of the first laser beam L1 and the second beam shape B2 of the second laser beam L2, the size and shape of each beam shape, the intensity of each laser beam, etc., even during processing. Therefore, the workpiece W can be efficiently preheated, the molten pool M can be stabilized, and spatter and the formation of porosity in the weld bead can be reduced. Furthermore, according to this embodiment, as in the first embodiment, the laser processing apparatus 2 does not require optical components equipped with a reflective film or coating that simultaneously reflects or transmits light in multiple wavelength ranges, and can be configured inexpensively.

[0061] Furthermore, according to this embodiment, the laser processing device 2 is provided with a robot corresponding to each processing head, and each robot can individually change the position of each processing head relative to the workpiece W according to the usage environment and the shape of the workpiece W, thereby increasing the degree of freedom in the position of the processing head during welding processing.

[0062] (Third embodiment) The laser processing apparatus 3 of the third embodiment is similar to the second embodiment except that the first processing head 50 is provided with an OCT system that monitors welding. Therefore, parts that perform the same functions as those of the first and second embodiments are given the same reference numerals, and redundant explanations will be omitted.

[0063] 8 is a diagram showing a first processing head 50 and an OCT system 90 of a laser processing apparatus 3 of the third embodiment. Similar to the laser processing apparatus 2 of the second embodiment, the laser processing apparatus 3 of the third embodiment is equipped with a first laser light source 11, a second laser light source 12, a first processing head 50, a second processing head 60, etc., and further equipped with an OCT system 90. For ease of understanding, FIG. 8 shows only the first laser light source 11, the first processing head 50, the OCT system 90, and the workpiece W, and omits the second processing head 60, the control device 70, the robots 82 and 83, etc.

[0064] The laser processing apparatus 3 of the third embodiment has an OCT (Optical Coherence Tomography) system 90 attached to the first processing head 50. The OCT system 90 is a sensor system that determines the optical path length difference between light reflected at a measurement point and reference light from the interference fringes of the two lights. This OCT system 90 can monitor the keyhole depth (which approximates the weld depth) by measurement during welding, thereby making it possible to directly determine whether the welding is good or bad.

[0065] The OCT system 90 is an optical coherence interferometer unit including an OCT system control unit 91, a measurement light source 93, an OCT scanner 94, etc. The OCT system control unit 91 is a measurement light control unit that communicates with the control device 70 and controls the operations of the measurement light source 93 and the OCT scanner 94. The OCT system control unit 91 includes a calculation unit 92 for analyzing a keyhole, etc.

[0066] The measurement light source 93 is a light source that generates the measurement light L3. The measurement light L3 is low-coherence light with a wavelength of 800 to 950 nm. The OCT scanner 94 is a mechanism for scanning the measurement light L3, and includes optical components such as lenses and mirrors (not shown), as well as a deflection mechanism for deflecting the measurement light L3. A galvanometer scanner or a polygon mirror is used as the deflection mechanism for the measurement light L3. This deflection mechanism optically couples the measurement light L3 to the optical path of the first laser light L1 in the first processing head 50. Note that in FIG. 8, the first laser light L1 and the measurement light L3 are shown separated from each other for ease of understanding.

[0067] The mirror 54 in the first processing head 50 has the function of reflecting the first laser light L1 (wavelength 900 to 1100 nm) and simultaneously transmitting the measurement light L3 (wavelength 800 to 950 nm). The first deflection mechanism 30 also includes mirrors 33 and 34. These mirrors 33 and 34 correspond to the mirrors 31 and 32 in the first and second embodiments, but differ from the mirrors 31 and 32 in the wavelength range of light they can reflect, and are therefore capable of reflecting the first laser light L1 (wavelength 900 to 1100 nm) and the measurement light L3 (wavelength 800 to 950 nm). The mirrors 31 and 32 have an average reflectivity of 50% or more for light with a wavelength of 800 to 950 nm.

[0068] The measurement light L3 traveling from the OCT system 90 to the first processing head 50 passes through the mirror 54 and travels to the first deflection mechanism 30, where it is irradiated onto a predetermined position on the workpiece W together with the first laser light L1.

[0069] In conventional laser processing apparatuses, two laser beams are coaxially superimposed as described above, and therefore, if the OCT system 90 is further provided, optical components compatible with three wavelengths are required. For example, in conventional laser processing apparatuses, a mirror equivalent to the above-described mirror 54 requires a coating or the like that reflects the first laser beam L1 and transmits the second laser beam L2 and the measurement beam L3. In contrast, the laser processing apparatus 3 of the present embodiment does not require such optical components, and can simply use optical components such as a mirror compatible with two wavelengths, such as the above-described mirror 54, which can be implemented inexpensively and simply.

[0070] In the above description, an example in which the OCT system 90 is provided has been shown, but the present invention is not limited to this, and for example, the laser processing apparatus 3 may be provided with various other devices for checking the welding state, etc. For example, the laser processing apparatus 3 may be provided with a welding monitoring system using an imaging element such as a CMOS or a CCD, or may be provided with a welding monitoring system using a photodiode.

[0071] The OCT system 90 may be attached to the processing head 20 of the first embodiment, and the measurement light L3 may be irradiated by combining the optical path with the first laser light L1. Furthermore, the measurement light L3 may be irradiated together with the second laser light L2.

[0072] According to this embodiment, the laser processing apparatus 3 can individually control the first laser beam L1 and the second laser beam L2, as in the first and second embodiments, and can efficiently preheat the workpiece W, stabilize the molten pool M, and reduce spatter and porosity formation in the weld bead. Furthermore, according to this embodiment, the laser processing apparatus 3 can incorporate a welding monitoring system such as an OCT system 90 at a lower cost.

[0073] (Modified Embodiment) In each embodiment, the first laser beam L1 may be irradiated while being oscillated in a predetermined direction. The second laser beam L2 may also be irradiated while being oscillated in a predetermined direction. FIG. 9 is a diagram showing the first beam shape B1, the second beam shape B2, and the molten pool M on the surface of the workpiece W when the first laser beam L1 is oscillated in the direction of arrow d. As shown in FIG. 9, the first beam shape B1 of the first laser beam L1 oscillates in the direction of arrow d with a predetermined amplitude (movement amount) and speed. In FIG. 9, the direction of arrow d is shown as being parallel to the Y direction, but the oscillation direction, amplitude, speed, etc. may be set as appropriate. At this time, the second beam shape B2 of the second laser beam L2 does not oscillate.

[0074] Such oscillation of the first beam shape B1 is possible by rapidly changing the rotation angles of the mirrors 31 and 32 of the first deflection mechanism 30 in response to a command from the scanner control unit 72. Oscillating the first beam shape B1 makes it possible to increase the weld (bead) width.

[0075] Furthermore, without being limited to the above example, the scanner control unit 72 may control the first deflection mechanism 30 and the second deflection mechanism 40 to oscillate the second beam shape B2 in a predetermined direction without oscillating the first beam shape B1. By oscillating the second beam shape B2, the preheating area can be widened and the molten pool M can be stabilized. Furthermore, without being limited to the above example, the scanner control unit 72 may control the first deflection mechanism 30 and the second deflection mechanism 40 to oscillate both the first beam shape B1 and the second beam shape B2 in a predetermined direction.

[0076] In each embodiment, the workpiece W may be placed on a stage that is movable in the X, Y, and Z directions. The movement of the stage may be controlled by the control device 70.

[0077] In each embodiment, the material of the workpiece W is copper or a copper alloy, but the material is not limited to this, and the workpiece W may be made of other metals, for example, aluminum. In this case, it is preferable that the wavelength of the second laser light L2 is 900 to 1100 nm, the same as that of the first laser light L1.

[0078] The following supplementary notes are further disclosed regarding the above-described embodiment. (Supplementary Note 1) A laser beam source (11) for generating a first laser beam (L1) having a wavelength of 900 to 1100 nm, a second laser beam source (12) for generating a second laser beam (L2) having a wavelength equal to or shorter than that of the first laser beam, a light source control unit (71) for controlling oscillation and output of the first laser beam source and the second laser beam source, a first lens mechanism (21, 51) for controlling a focal position (F1) of the first laser beam, a second lens mechanism (23, 61) for controlling a focal position of the second laser beam, a first deflection mechanism (30) having at least one mirror (31, 32, 33, 34) capable of reflecting the first laser beam and capable of changing the irradiation position of the first laser beam, and a second laser beam source (12) for generating a second laser beam (L2) having a wavelength equal to or shorter than that of the first laser beam. A laser processing device (1, 2, 3) comprising: a second deflection mechanism (40) having at least one mirror (41, 42) capable of reflecting light and capable of changing the irradiation position of the second laser light; and a scanner control unit (72) that controls the operation of the first lens mechanism and the second lens mechanism and the operation of the first deflection mechanism and the second deflection mechanism, wherein the scanner control unit controls the first deflection mechanism and the second deflection mechanism individually while causing them to operate in coordination, thereby changing the relative position of the center (t1) of the first beam shape (B1) of the first laser light and the center (t2) of the second beam shape (B2) of the second laser light on a workpiece (W) that is the object to be processed.

[0079] (Supplementary Note 2) The laser processing device according to Supplementary Note 1, wherein the scanner control unit (72) controls the second laser light (L2) to be irradiated onto the workpiece (W) ahead of the first laser light (L1).

[0080] (Appendix 3) The laser processing apparatus described in Appendix 1, wherein the scanner control unit (72) controls the first deflection mechanism (30) and the second deflection mechanism (40) so that at least one of the first laser light (L1) and the second laser light (L2) is irradiated onto the workpiece (W) while oscillating in a predetermined direction.

[0081] (Appendix 4) The laser processing device described in Appendix 1, wherein the scanner control unit (72) individually controls the first lens mechanism and the second lens mechanism to individually change the diameter of the first beam shape (B1) of the first laser light (L1) and the diameter of the second beam shape (B2) of the second laser light (L2).

[0082] (Supplementary Note 5) The laser processing device according to Supplementary Note 1, wherein the second laser light (L2) has a wavelength of 400 to 550 nm or 900 to 1100 nm.

[0083] (Supplementary Note 6) The laser processing device according to Supplementary Note 1, wherein the mirrors (33, 34) capable of reflecting the first laser light (L1) have an average reflectance of 50% or more for light having a wavelength of 800 to 950 nm.

[0084] (Appendix 7) The laser processing device described in Appendix 1, wherein the scanner control unit (72) is capable of setting and storing in advance conditions related to the outputs of the first laser light source (11) and the second laser light source (12), the relative position between the center (t1) of the first beam shape (B1) and the center (t2) of the second beam shape (B2) on the workpiece (W), and the focal positions (F1, F2) of the first laser light (L1) and the second laser light (L2) according to information related to the workpiece (W).

[0085] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0086] 1, 2, 3 Laser processing device 11 First laser light source 12 Second laser light source 20 Processing head 21, 51 First lens mechanism 22, 52 Lens 23, 61 Second lens mechanism 24, 62 Lens 30 First deflection mechanism 31, 32, 33, 34 Mirror 40 Second deflection mechanism 41, 42 Mirror 50 First processing head 60 Second processing head 53, 63 Mirror 54 Mirror 70 Control device 71 Light source control unit 72 Scanner control unit W Work

Claims

1. A scanner comprising: a first laser light source that generates a first laser light having a wavelength of 900 to 1100 nm; a second laser light source that generates a second laser light having a wavelength equal to or shorter than that of the first laser light; a light source control unit that controls the oscillation and output of the first laser light source and the second laser light source; a first lens mechanism that controls the focal position of the first laser light; a second lens mechanism that controls the focal position of the second laser light; a first deflection mechanism that has at least one mirror that can reflect the first laser light and can change the irradiation position of the first laser light; a second deflection mechanism that has at least one mirror that can reflect the second laser light and can change the irradiation position of the second laser light; and a scanner control unit that controls the operation of the first lens mechanism and the second lens mechanism and the operation of the first deflection mechanism and the second deflection mechanism, The scanner control unit of this laser processing device is capable of changing the relative position between the center of the first beam shape of the first laser light and the center of the second beam shape of the second laser light on a workpiece, which is an object to be processed, by individually controlling the first deflection mechanism and the second deflection mechanism while causing them to operate in coordination.

2. The laser processing device according to claim 1, wherein the scanner control unit controls the second laser light to be irradiated onto the workpiece prior to the first laser light.

3. The laser processing device according to claim 1, wherein the scanner control unit controls the first deflection mechanism and the second deflection mechanism so that at least one of the first laser light and the second laser light is irradiated onto the workpiece while oscillating in a predetermined direction.

4. The laser processing device according to claim 1, wherein the scanner control unit controls the first lens mechanism and the second lens mechanism individually to change the diameter of the first beam shape of the first laser light and the diameter of the second beam shape of the second laser light individually.

5. The laser processing device according to claim 1, wherein the second laser light has a wavelength of 400 to 550 nm, or 900 to 1100 nm.

6. The laser processing device according to claim 1, wherein the mirror capable of reflecting the first laser light has an average reflectance of 50% or more for light with a wavelength of 800 to 950 nm.

7. The laser processing device of claim 1, wherein the scanner control unit is capable of presetting and storing conditions relating to the output of the first laser light source and the second laser light source, the relative positions of the centers of the first beam shape and the second beam shape on the workpiece, and the focal positions of the first laser light and the second laser light, in accordance with information relating to the workpiece.

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