Method for manufacturing metal parts

Abstract

The present invention provides a method for manufacturing a metal component that suppresses hole formation caused by welding. The method includes a welding process for welding a butt joint between a first metal plate and a second metal plate having a plate thickness greater than that of the first plate. The welding process includes: a first process of applying energy to melt the metal starting at a first position on the second plate, and moving the energy application position from the first position toward a second position on the butt joint, the first position being away from the butt joint and one end of the second plate; a second process of moving the energy application position from the second position toward a third position on the butt joint, away from the other end of the second plate, along the butt joint to weld the butt joint; and a third process of moving the energy application position from the third position toward a fourth position on the second plate, away from the butt joint, and ending the energy application at the fourth position.

Description

Technical Field

[0001] The present disclosure relates to methods of manufacturing metal parts. Background Art

[0002] Regarding a method for manufacturing metal parts, Patent Document 1 discloses a method in which, in order to form a good molten pool during laser welding, the heat input at the start of welding is set to be greater than the heat input at the actual weld, and the heat input at the end of welding is set to be less than the heat input at the actual weld.

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-039145 Summary of the Invention

[0005] Problems to be solved by the invention

[0006] In the above-mentioned method, in order to suppress the opening of holes at the welding start and welding end, it is necessary to precisely set the heat input at the welding start and welding end, which is time-consuming and labor-intensive. Therefore, a technology that can suppress the opening of holes at the welding start and welding end using a simpler method is desired.

[0007] Technical solutions to problems

[0008] The present disclosure can be implemented in the following forms.

[0009] (1) According to one embodiment of the present disclosure, a method for manufacturing a metal component is provided. The method comprises the following steps: a butting step of arranging the first metal plate and the second metal plate so that the end face of the first metal plate butts against the end face of a second metal plate having a greater thickness than the first metal plate; and a welding step of welding the butted portion formed by the butted end faces of the first and second metal plates. The above-mentioned welding process has the following processes: a first process, starting to impart energy to melt the metal at a first position which is a position on the above-mentioned second plate, and moving the above-mentioned energy imparting position from the above-mentioned first position toward a second position on the above-mentioned docking portion, and the above-mentioned first position is away from a predetermined distance from one end of the above-mentioned docking portion and the above-mentioned second plate in the direction along the above-mentioned docking portion; a second process, welding the above-mentioned docking portion by moving the above-mentioned energy imparting position from the above-mentioned second position toward a third position which is a position on the above-mentioned docking portion along the above-mentioned docking portion, and the above-mentioned third position is away from a predetermined distance from the other end of the above-mentioned second plate in the direction along the above-mentioned docking portion; and a third process, moving the above-mentioned energy imparting position from the above-mentioned third position toward a fourth position which is a position on the above-mentioned second plate, and ending the above-mentioned energy imparting at the above-mentioned fourth position, and the above-mentioned fourth position is away from the above-mentioned docking portion by a predetermined distance.

[0010] According to this method for manufacturing a metal component, energy application begins at a first position on a second plate having a greater thickness than the first plate and ends at a fourth position on the second plate. Therefore, cracking is less likely to occur when energy application begins and ends. Therefore, even without precisely setting the heat input at the first and fourth positions, cracking can be suppressed.

[0011] (2) In the method for manufacturing a metal component according to the above aspect, in the welding step, the butted portion may be welded by laser welding or laser-arc hybrid welding which is a combination of the laser welding and arc welding.

[0012] According to the method for manufacturing a metal part of this aspect, since the butting portion is welded by laser welding or laser arc hybrid welding, the butting portion can be welded at a high speed.

[0013] (3) In the method for manufacturing a metal part of the above-mentioned embodiment, the focal spot diameter of the laser used for the laser welding may be greater than 0.5 mm and less than 1.2 mm, and at least one of the distance between the first position and the docking portion and the distance between the fourth position and the docking portion may be greater than 1.0 mm and less than 5.0 mm.

[0014] According to this method for manufacturing metal parts, the distance between the first position where the laser irradiation starts and the docking part and the distance between the fourth position where the laser irradiation ends and the docking part can be fully ensured, thereby preventing the metal melted by the laser irradiation from falling from the docking part and leaving a hole at the beginning and end of the laser irradiation.

[0015] (4) In the manufacturing method of the metal part of the above-mentioned embodiment, the focal spot diameter of the laser for the laser welding may be greater than 0.5 mm and less than 1.2 mm, and at least one of the distance between the first position and the one end of the second plate and the distance between the third position and the other end of the second plate may be greater than 1.0 mm and less than 5.0 mm.

[0016] According to this method for manufacturing a metal part, the distance between the laser irradiation position and one end and the other end of the second plate can be sufficiently ensured, thereby preventing the molten metal from falling from one end or the other end of the second plate due to the laser irradiation and forming a hole.

[0017] The present disclosure can also be implemented in various forms other than the method for manufacturing a metal part, for example, in the form of a laser welding method, a laser welding device, a laser arc hybrid welding method, a laser arc hybrid welding device, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a perspective view showing a schematic structure of a metal member according to the first embodiment.

[0019] Figure 2 It is an explanatory diagram showing a schematic configuration of a welding device according to a first embodiment.

[0020] Figure 3 This is a flowchart showing the details of the method for manufacturing a metal component according to the first embodiment.

[0021] Figure 4 This is a plan view showing the movement paths of the laser and arc during the welding process.

[0022] Figure 5 This is an explanatory diagram showing the moving speed and output of the laser beam during the welding process.

[0023] Figure 6 It is an explanatory diagram showing the welding process according to the first embodiment.

[0024] Figure 7 It is an explanatory diagram showing the welding process of a comparative example. DETAILED DESCRIPTION

[0025] A. First embodiment:

[0026] Figure 1 This is a perspective view schematically illustrating the structure of a metal component 10 according to the first embodiment. The metal component 10 includes a thin plate portion 11, a thick plate portion 12, and a welded joint portion 13. The thin plate portion 11 and the thick plate portion 12 are plate-shaped. The thickness t2 of the thick plate portion 12 is greater than the thickness t1 of the thin plate portion 11. The welded joint portion 13 secures the thin plate portion 11 and the thick plate portion 12 to each other.

[0027] The thin plate portion 11 and the thick plate portion 12 are formed from the same type of metal material. In this embodiment, the thin plate portion 11 and the thick plate portion 12 are made of steel. The material of the thin plate portion 11 and the thick plate portion 12 is not limited to steel; for example, aluminum alloys, titanium alloys, or magnesium alloys may also be used. Furthermore, the thin plate portion 11 and the thick plate portion 12 may be formed from different types of metal materials. For example, the thin plate portion 11 may be formed from steel, and the thick plate portion 12 may be formed from an aluminum alloy.

[0028] The metal component 10 is manufactured by butt-welding a first metal plate 20 having the same thickness as plate t1 and a second metal plate 30 having the same thickness as plate t2. The thin plate portion 11 is formed by the first plate 20, and the thick plate portion 12 is formed by the second plate 30. The welded joint portion 13 is formed by butt-welding the first plate 20 and the second plate 30. In this embodiment, the first plate 20 and the second plate 30 are flat plates. In other embodiments, at least one of the first plate 20 and the second plate 30 may be a curved plate rather than a flat plate.

[0029] Figure 2 This is an explanatory diagram schematically illustrating the general configuration of a welding apparatus 100 used in the manufacture of a metal component 10 according to this embodiment. In this embodiment, the welding apparatus 100 includes a laser welding unit 110, an arc welding unit 120, a welding position changing unit 130, a worktable 140, and a control unit 150. A first plate 20 and a second plate 30 serving as workpieces WK are secured to the worktable 140. The first and second plates 20, 30 are secured to the worktable 140 such that the end surface of the first plate 20 abuts against the end surface of the second plate 30.

[0030] The laser welding unit 110 includes a laser oscillator 111 and a laser head 115. The laser oscillator 111 generates a laser beam LS. In this embodiment, the laser beam LS generated by the laser oscillator 111 is a fiber laser. The laser beam LS generated by the laser oscillator 111 may also be a solid-state laser other than a fiber laser, such as a disk laser, a semiconductor laser, or a YAG laser. The laser beam LS generated by the laser oscillator 111 may also be a gas laser such as a carbon dioxide gas laser, rather than a solid-state laser.

[0031] The laser head 115 is connected to the laser oscillator 111 via the optical fiber 112. The laser light LS generated by the laser oscillator 111 is transmitted from the laser oscillator 111 to the laser head 115 via the optical fiber 112 and emitted from the laser head 115 toward the workpiece WK. In the case where the laser light LS generated by the laser oscillator 111 is a carbon dioxide gas laser, the laser light LS may be transmitted from the laser oscillator 111 to the laser head 115 via a bending mirror instead of the optical fiber 112. Figure 2 Although not shown in the figure, argon gas or the like is supplied to the laser head 115 as a shielding gas.

[0032] The arc welding unit 120 includes a welding power supply 121 and an arc welding torch 125. The welding power supply 121 is electrically connected to the arc welding torch 125 via a power cable 122. The welding power supply 121 is electrically connected to the workpiece WK via a ground cable 123. The welding power supply 121 applies a voltage between the arc welding torch 125 and the workpiece WK, generating an arc AC between the arc welding torch 125 and the workpiece WK.

[0033] The arc welding torch 125 is configured as an arc welding torch for MIG welding, carbon dioxide gas arc welding or MAG welding. Figure 2 Although not shown in the figure, the arc welding torch 125 is supplied with a welding wire mainly composed of the same material as the workpiece WK as an electrode, and argon gas, carbon dioxide gas, or a mixed gas of argon and carbon dioxide gas is supplied as a shielding gas. The arc welding torch 125 may also be configured as an arc welding torch for TIG welding.

[0034] The welding position changing unit 130 changes the relative positions of the laser head 115 and the arc welding torch 125 relative to the workpiece WK. In this embodiment, the welding position changing unit 130 is composed of a robot arm. More specifically, the welding position changing unit 130 is composed of a vertical multi-jointed robot having six rotation axes J1 to J6. At the front end of the welding position changing unit 130, the laser head 115 and the arc welding torch 125 are fixed via a fixing component 135. The welding position changing unit 130 changes the relative positions of the laser head 115 and the arc welding torch 125 relative to the workpiece WK by moving the laser head 115 and the arc welding torch 125 fixed to the fixing component 135 as a whole. In addition, the welding position changing unit 130 may also be composed of, for example, a horizontal multi-jointed robot instead of a vertical multi-jointed robot. The welding position changing unit 130 may also be composed of, for example, a combination of an electric linear actuator instead of a robot arm.

[0035] In other embodiments, the welding position changing unit 130 may move the laser head 115 and the arc welding torch 125 independently of each other, rather than moving them together. The welding position changing unit 130 may also move the table 140 rather than the laser head 115 and the arc welding torch 125, thereby changing the relative positions of the laser head 115 and the arc welding torch 125 with respect to the workpiece WK. Furthermore, the welding position changing unit 130 may change the relative positions of the laser head 115 and the arc welding torch 125 with respect to the workpiece WK by moving the laser head 115, the arc welding torch 125, and the table 140.

[0036] The control unit 150 is configured as a computer equipped with a CPU, memory, and input / output interfaces. In this embodiment, the control unit 150 controls the laser welding unit 110 to irradiate the workpiece WK with a laser beam LS from the laser head 115, and controls the arc welding unit 120 to irradiate the workpiece WK with an arc AC from the arc welding torch 125, thereby imparting energy to the workpiece WK to melt the metal. The control unit 150 controls the welding position changing unit 130 to change the relative positions of the laser head 115 and the arc welding torch 125 relative to the workpiece WK, thereby shifting the irradiation positions of the laser beam LS and the arc AC on the workpiece WK, or in other words, the positions at which energy is applied to the workpiece WK. Alternatively, the control unit 150 may be configured not as a computer but as a combination of multiple circuits.

[0037] Figure 3 This is a flowchart showing the details of the method for manufacturing the metal component 10 according to the present embodiment. Figure 4 : is a top view showing the moving path of the irradiation position of the laser LS and the arc AC. Figure 3 As shown, first, in step S110, the first plate 20 and the second plate 30 are arranged so that the end faces of the first plate 20 and the second plate 30 are butted against each other. In this embodiment, the first plate 20 and the second plate 30 are fixed to the workbench 140 so that the end faces of the first plate 20 and the second plate 30 are butted against each other. At this time, a grounding cable 123 is connected to the first plate 20 or the second plate 30. When the first plate 20 and the second plate 30 are fixed to the workbench 140, the end faces of the first plate 20 and the second plate 30 may be in contact, or a gap of a predetermined width may be provided between the end faces of the first plate 20 and the second plate 30.

[0038] In this embodiment, the first plate 20 and the second plate 30 are fixed to the workbench 140 in such a manner that the bottom surface of the first plate 20 and the bottom surface of the second plate 30 are in the same plane. Alternatively, the first plate 20 and the second plate 30 may be fixed to the workbench 140 in such a manner that the top surface of the first plate 20 and the top surface of the second plate 30 are in the same plane, or the first plate 20 and the second plate 30 may be fixed to the workbench 140 in such a manner that a step is formed between the top surface of the first plate 20 and the top surface of the second plate 30 and a step is formed between the bottom surface of the first plate 20 and the bottom surface of the second plate 30.

[0039] Next, in step S120, the Figure 4 The irradiation of the laser LS and the arc AC begins at the first position P1 on the second plate 30 shown in FIG. Figure 4 The second position P2 on the butt joint 40 shown in FIG. In this embodiment, the laser welding unit 110 is controlled by the control unit 150 to initiate irradiation of the laser beam LS from the laser head 115, and the arc welding unit 120 is controlled by the control unit 150 to initiate irradiation of the arc AC from the arc torch 125. The focal spot diameter D of the laser beam LS is greater than or equal to 0.5 mm and less than or equal to 1.2 mm. The focal spot diameter D refers to the diameter of the focal spot.

[0040] In the present embodiment, the control unit 150 controls the welding position changing unit 130 to move the laser head 115 and the arc welding torch 125 relative to the stage 140 , thereby moving the irradiation positions of the laser beam LS and the arc AC.

[0041] The first position P1 is a position separated by a predetermined distance from the butting portion 40 where the first plate 20 and the second plate 30 butt joint, and is also separated by a predetermined distance from one end of the second plate 30 along the butting portion 40. In this embodiment, the distance L1 between the first position P1 and the butting portion 40 is greater than or equal to 1.0 mm and less than or equal to 5.0 mm. The distance L2 between the first position P1 and one end of the second plate 30 is greater than or equal to 1.0 mm and less than or equal to 5.0 mm.

[0042] The second position P2 is a position separated by a predetermined distance from one end of the second plate 30. In the present embodiment, a distance L3 between the second position P2 and one end of the second plate 30 is not less than 1.0 mm and not more than 5.0 mm.

[0043] exist Figure 3 In step S130, the irradiation position of the laser LS and the arc AC is from the second position P2 toward Figure 4The third position P3 on the butt joint 40 is shown as moving along the butt joint 40 , whereby the first plate 20 and the second plate 30 are welded.

[0044] The third position P3 is a position separated by a predetermined distance from the other end of the second plate 30 in the direction along the butting portion 40. In this embodiment, a distance L4 between the third position P3 and the other end of the second plate 30 is 1.0 mm to 5.0 mm.

[0045] exist Figure 3 In step S140, the irradiation position of the laser LS and the arc AC is from the third position P3 toward Figure 4 After the movement to the fourth position P4 on the second plate 30 is shown, the irradiation of the laser beam LS and the arc AC is terminated at the fourth position P4. In this embodiment, the control unit 150 controls the laser welding unit 110 to terminate the irradiation of the laser beam LS from the laser head 115, and the control unit 150 controls the arc welding unit 120 to terminate the irradiation of the arc AC from the arc welding torch 125.

[0046] The fourth position P4 is a predetermined distance away from the butt joint 40 and the other end of the second plate 30. In this embodiment, a distance L5 between the fourth position P4 and the butt joint 40 is greater than or equal to 1.0 mm and less than or equal to 5.0 mm. A distance L6 between the fourth position P4 and the other end of the second plate 30 is greater than or equal to 1.0 mm and less than or equal to 5.0 mm.

[0047] The process from step S120 to step S140 is called a welding process. In the welding process, the process of step S120 is called a first process, the process of step S130 is called a second process, and the process of step S140 is called a third process. Figure 4 1 shows the movement path R1 of the irradiation position of the laser LS and the arc AC in the first step, the movement path R2 of the irradiation position of the laser LS and the arc AC in the second step, and the movement path R3 of the irradiation position of the laser LS and the arc AC in the third step. In this embodiment, the movement path R1 in the first step is parallel to one end of the second plate 30. Because the docking portion 40 forms a straight line when viewed from above, the movement path R2 in the second step is also a straight line. The movement path R3 in the third step is parallel to the other end of the second plate 30. In the first through third steps, the laser LS and the arc AC are irradiated in a single stroke along these movement paths R1 to R3. In other embodiments, the movement path R1 in the first step may be parallel to a direction intersecting one end of the second plate 30, and the movement path R3 in the third step may be parallel to a direction intersecting the other end of the second plate 30.

[0048] The first plate 20 and the second plate 30 are integrated by welding, thereby manufacturing the metal component 10. The metal component 10 is then removed from the work table 140. The portion of the metal component 10 located on one end relative to the second position P2 and the portion located on the other end relative to the third position P3 are not irradiated with the laser beam LS and the arc AC, and no welded joint 13 is formed. In this embodiment, after the metal component 10 is removed from the work table 140, the portion located on one end relative to the second position P2 and the portion located on the other end relative to the third position P3 are removed by cutting.

[0049] Figure 5 1 is an explanatory diagram showing the moving speed of the irradiation position of the laser LS and the output of the laser LS in the above-mentioned steps S120 to S140. Figure 5 In FIG. 1 , the horizontal axis represents the position on the workpiece WK, and the vertical axis represents the moving speed of the irradiation position of the laser light LS and the output of the laser light LS.

[0050] In this embodiment, when moving the irradiation position of laser light LS from a first position P1 to a second position P2, the control unit 150 increases the speed of movement of the irradiation position of laser light LS as the position moves from the first position P1 to the second position P2, and increases the output of laser light LS as the position moves from the first position P1 to the second position P2. More specifically, the control unit 150 begins irradiating the first position P1 with a predetermined output Pw1, and then begins moving the irradiation position of laser light LS from the first position P1 to the second position P2. At this point, the control unit 150 linearly increases the speed of movement of the irradiation position of laser light LS and the output of laser light LS, so that the speed of movement of the irradiation position of laser light LS, which begins at an initial speed of zero, reaches a predetermined speed V1 near the second position P2, and the output of laser light LS reaches a predetermined output Pw2 near the second position P2. In other embodiments, the control unit 150 may also increase the speed of movement of the irradiation position of laser light LS or the output of laser light LS nonlinearly.

[0051] When the irradiation position of laser light LS is moved from the second position P2 to the third position P3, the control unit 150 maintains the moving speed of the irradiation position of laser light LS and the output of laser light LS constant. More specifically, the control unit 150 maintains the moving speed of the irradiation position of laser light LS at speed V1 and the output of laser light LS at output Pw2.

[0052] When moving the irradiation position of laser light LS from third position P3 to fourth position P4, control unit 150 slows the movement speed of the irradiation position of laser light LS as it approaches fourth position P4 from third position P3, thereby reducing the output of laser light LS as it approaches fourth position P4. More specifically, control unit 150 linearly reduces the movement speed of the irradiation position of laser light LS and the output of laser light LS, such that the movement speed of the irradiation position of laser light LS reaches zero at fourth position P4 and the output of laser light LS reaches output Pw1 at fourth position P4. In other embodiments, the output of laser light LS at fourth position P4 may be smaller than output Pw2 and larger than output Pw1, or smaller than output Pw1. Control unit 150 may also linearly reduce the movement speed of the irradiation position of laser light LS or the output of laser light LS.

[0053] In this embodiment, the control unit 150 sets the movement speed of the laser LS irradiation position at the first position P1 and the fourth position P4 to zero, thereby preventing deviations in the laser LS irradiation start and end positions. Furthermore, the control unit 150 sets the movement speed of the laser LS irradiation position from the second position P2 to the third position P3 faster than the movement speed from the first position P1 to the second position P2 and the movement speed from the third position P3 to the fourth position P4, thereby preventing increases in welding time. Furthermore, the control unit 150 maintains the movement speed and output of the laser LS irradiation position constant when moving the laser LS irradiation position from the second position P2 to the third position P3, thereby preventing variations in weld quality at various locations on the butt joint 40. Furthermore, the control unit 150 adjusts the movement speed and output of the laser LS irradiation position by linearly varying these speeds, enabling simple control to adjust the movement speed and output of the laser LS irradiation position.

[0054] Figure 6 It is an explanatory diagram schematically showing the welding process according to the present embodiment. Figure 7 : is an explanatory diagram schematically showing the welding process in a comparative example. Figure 6 , after starting irradiation of the laser LS and the arc AC toward the first position P1, the irradiation position of the laser LS and the arc AC is moved from the first position P1 to the third position P3 via the second position P2. Figure 7 , a case is shown in which, after irradiation of the laser light LS and the arc AC is started toward the end of the butting portion 40 , the irradiation position of the laser light LS and the arc AC is moved from one end toward the other end of the butting portion 40 .

[0055] like Figure 6 As shown, by irradiating the workpiece WK with the laser LS and the arc AC, the workpiece WK is melted to form a molten pool composed of molten metal MM. Generally speaking, the closer to the end of the workpiece WK, the easier it is for the molten metal MM to fall from the end of the workpiece WK. Therefore, the closer to the end of the workpiece WK, the easier it is to make a hole in the workpiece WK. In the docking portion 40, since the molten metal MM sometimes falls from between the first plate 20 and the second plate 30, it is easier to make a hole in the docking portion 40 than in the portion other than the docking portion 40. In the portion other than the docking portion 40, the smaller the plate thickness, the easier it is to make a hole. Therefore, as Figure 7 As shown, after starting irradiation of the laser beam LS toward the end of the butting portion 40 , when the irradiation position of the laser beam LS is moved from one end toward the other end of the butting portion 40 , the hole HL is easily formed in the workpiece WK.

[0056] On the other hand, according to the manufacturing method of the metal component 10 of the present embodiment described above, in the welding process, Figure 6 As shown, energy application to the workpiece WK begins at a first position P1 on the second plate 30, which has a thickness t2 greater than the thickness t1 of the first plate 20, and ends at a fourth position P4 on the second plate 30. This reduces the risk of holes forming when energy application to the workpiece WK begins and ends. Therefore, even without precisely setting the heat input at the first position P1 and the fourth position P4, the formation of holes in the workpiece WK can be suppressed. In particular, in this embodiment, the workpiece WK is welded using laser-arc hybrid welding, a combination of laser welding and arc welding. Specifically, energy is applied to the workpiece WK by irradiation with both the laser beam LS and the arc AC. Consequently, welding can be performed at higher speeds compared to arc welding alone. Furthermore, compared to laser welding alone, melting can be achieved over a wider area, simplifying the management of the gap between the first and second plates 20, 30 in the butt joint 40.

[0057] Furthermore, in this embodiment, the focal spot diameter D of the laser LS is 0.5 mm to 1.2 mm, and the distance L1 between the first position P1 where irradiation with the laser LS begins and the butt joint 40, and the distance L5 between the fourth position P4 where irradiation with the laser LS ends and the butt joint 40, are 1.0 mm to 5.0 mm. Therefore, at the start and end of irradiation with the laser LS, it is possible to prevent molten metal from falling from the butt joint 40 and creating a hole.

[0058] Furthermore, in this embodiment, the focal spot diameter D of the laser light LS is 0.5 mm to 1.2 mm, and the distance L2 between the first position P1 and one end of the second plate 30, the distance L3 between the second position P2 and one end of the second plate 30, the distance L4 between the third position P3 and the other end of the second plate 30, and the distance L6 between the fourth position P4 and the other end of the second plate 30 are 1.0 mm to 5.0 mm. Consequently, the distances between the irradiation position of the laser light LS and one end and the other end of the second plate 30 are sufficiently maintained, thereby preventing molten metal from falling from one end and the other end of the second plate 30 and causing holes to form. In particular, in this embodiment, as described above, the portion of the metal component 10 produced by welding the first and second plates 20 and 30 that is not welded to the butt joint 40, namely, the portion closer to the one end of the second plate 30 relative to the second position P2 and the portion closer to the other end of the second plate 30 relative to the third position P3, is removed by cutting. By setting the distance L3 between the second position P2 and one end of the second plate 30 and the distance L4 between the third position P3 and the other end of the second plate 30 to be 5.0 mm or less, the area of ​​the portion removed by cutting can be reduced, thereby suppressing deterioration in yield.

[0059] B. Other implementation methods:

[0060] (B1) In the method for manufacturing the metal component 10 of the above-described embodiment, the metal component 10 is manufactured by welding the first plate 20 and the second plate 30 by laser-arc hybrid welding, which is a combination of laser welding and arc welding. Alternatively, the metal component 10 may be manufactured by welding the first plate 20 and the second plate 30 by laser welding without combining with arc welding. The metal component 10 may also be manufactured by welding the first plate 20 and the second plate 30 by arc welding without combining with laser welding, or by welding the first plate 20 and the second plate 30 by electron beam welding.

[0061] (B2) In the methods for manufacturing the metal component 10 of the above-described embodiments, the butt joint 40 is formed into a straight line when viewed from above, and the movement path R2 of the irradiation position of the laser beam LS and the arc AC in the second step of the welding process is a straight line. In contrast, in the method for manufacturing the metal component 10, the butt joint 40 may have a curved portion when viewed from above, and the movement path R2 of the irradiation position of the laser beam LS and the arc AC in the second step may have a curved portion along the butt joint 40. For example, the butt joint 40 may have a wavy shape when viewed from above, and the movement path R2 of the irradiation position of the laser beam LS and the arc AC in the second step may be a wavy shape along the butt joint 40.

[0062] (B3) In the methods for manufacturing the metal component 10 according to the above-described embodiments, the distance L1 between the first position P1 at which irradiation with the laser beam LS is initiated and the butting portion 40, and the distance L5 between the fourth position P4 at which irradiation with the laser beam LS is terminated and the butting portion 40, are both 1.0 mm or greater and 5.0 mm or less. In contrast, at least one of the distance L1 between the first position P1 at which irradiation with the laser beam LS is initiated and the butting portion 40, and the distance L5 between the fourth position P4 at which irradiation with the laser beam LS is terminated and the butting portion 40, may be less than 1.0 mm or may exceed 5.0 mm.

[0063] (B4) In the manufacturing methods of the metal member 10 according to the above-described embodiments, the distance L2 between the first position P1 and one end of the second plate 30, the distance L3 between the second position P2 and one end of the second plate 30, the distance L4 between the third position P3 and the other end of the second plate 30, and the distance L6 between the fourth position P4 and the other end of the second plate 30 are 1.0 mm or more and 5.0 mm or less. In contrast, at least any one of the distance L2 between the first position P1 and one end of the second plate 30, the distance L3 between the second position P2 and one end of the second plate 30, the distance L4 between the third position P3 and the other end of the second plate 30, and the distance L6 between the fourth position P4 and the other end of the second plate 30 may be less than 1.0 mm or may exceed 5.0 mm.

[0064] (B5) In the methods for manufacturing the metal member 10 according to the above-described embodiments, the control unit 150 may cause the laser head 115 to start irradiating the metal member 10 with the laser beam LS at the first position P1 while moving the laser head 115 from the first position P1 toward the second position P2. In this case, unlike a method in which the laser head 115 starts irradiating the metal member 10 with the laser beam LS at the second position P2 while moving the laser head 115 from the second position P2 toward the third position P3, even if the timing of starting irradiation with the laser beam LS is unexpectedly advanced, the distance between the irradiation start position of the laser beam LS and one end of the second plate 30 is less likely to deviate. Therefore, it is possible to prevent the distance between the irradiation start position of the laser beam LS and one end of the second plate 30 from accidentally becoming closer, thereby preventing the formation of a hole.

[0065] (B6) In the methods for manufacturing the metal member 10 according to the above-described embodiments, the control unit 150 may cause the laser head 115 to terminate irradiation with the laser light LS at the fourth position P4 while moving the laser head 115 from the third position P3 toward the fourth position P4. In this case, unlike the method of terminating irradiation with the laser light LS at the third position P3 while moving the laser head 115 from the second position P2 toward the third position P3, even if the timing of terminating irradiation with the laser light LS is unexpectedly delayed, the distance between the position where irradiation with the laser light LS is terminated and the other end of the second plate 30 is less likely to deviate. Therefore, it is possible to prevent the distance between the position where irradiation with the laser light LS is terminated and the other end of the second plate 30 from accidentally becoming closer, thereby preventing the formation of a hole.

[0066] (B7) In the welding process of the method for manufacturing the metal component 10 according to each of the above-described embodiments, the connection between the movement paths R1 and R2, and the connection between the movement paths R2 and R3, may be arranged to describe a differentiable line. In this case, control of the welding position changing unit 130 is facilitated compared to a method in which the connection between the movement paths R1 and R2, or the connection between the movement paths R2 and R3, is arranged to describe a non-differentiable line, such as a method in which the movement paths R1 and R2 are bent at a right angle. Therefore, it is possible to prevent holes from forming near the second position P2 or the third position P3 due to a slow movement speed of the irradiation position of the laser beam LS.

[0067] The present disclosure is not limited to the above-mentioned embodiments and can be implemented in various structures within the scope of its main purpose. For example, the technical features in the embodiments corresponding to the technical features in each method described in the invention content column can be appropriately replaced or combined in order to solve part or all of the above-mentioned problems or to achieve part or all of the above-mentioned effects. In addition, as long as the technical features are not described as essential features in this specification, they can be appropriately deleted.

[0068] Description of Reference Numerals

[0069] 10…metal part, 11…thin plate portion, 12…thick plate portion, 13…welded joint portion, 20…first plate portion, 30…second plate portion, 40…jointing portion, 100…welding device, 110…laser welding portion, 111…laser oscillator, 112…optical fiber, 115…laser head, 120…arc welding portion, 121…welding power supply device, 122…power cable, 123…grounding cable, 125…arc welding torch, 130…welding position changing portion, 135…fixing component, 140…workbench, 150…control portion.

Claims

1. A method for manufacturing a metal component, comprising the following steps: a butting step of arranging the first plate and the second plate so that an end surface of the first metal plate butts against an end surface of a second metal plate having a thickness greater than that of the first plate; and The welding process is used to weld the butt joint formed by the end face of the first plate and the end face of the second plate, The welding process has the following steps: In a first step, energy for melting the metal is applied starting at a first position on the second plate, and the energy application position is moved from the first position toward a second position on the butting portion, the first position being a predetermined distance away from one end of the butting portion and the second plate in a direction along the butting portion. a second step of welding the butted portion by moving the energy application position from the second position toward a third position on the butted portion along the butted portion, the third position being a predetermined distance away from the other end of the second plate in a direction along the butted portion; and The third step is to move the energy imparting position from the third position toward a fourth position on the second plate, and to end the energy imparting at the fourth position, wherein the fourth position is away from the butting portion by a predetermined distance. In the welding process, the butt joint is welded by laser arc hybrid welding which is a combination of laser welding and arc welding. The focal spot diameter of the laser used in the laser welding is not less than 0.5 mm and not more than 1.2 mm. The distance between the first position and the docking portion and the distance between the fourth position and the docking portion are both greater than or equal to 1.0 mm and less than or equal to 5.0 mm. The distance between the first position and the one end of the second plate and the distance between the third position and the other end of the second plate are both 1.0 mm or more and 5.0 mm or less. The moving path of the irradiation position of the laser and the arc in the first step is parallel to the one end of the second plate, the moving path of the irradiation position of the laser and the arc in the second step is a straight line, and the moving path of the irradiation position of the laser and the arc in the third step is parallel to the other end of the second plate. In the first step, the moving speed of the laser irradiation position at the first position is set to zero, and when the laser irradiation position is moved from the first position to the second position, the moving speed of the laser irradiation position is linearly increased as the distance from the first position to the second position approaches, and the output of the laser is linearly increased as the distance from the first position to the second position approaches. In the second step, when the laser irradiation position is moved from the second position to the third position, the moving speed of the laser irradiation position and the laser output are kept constant. In the third process, when the irradiation position of the laser is moved from the third position to the fourth position, the moving speed of the irradiation position of the laser is linearly slowed down as it approaches the third position to the fourth position, the output of the laser is linearly reduced as it approaches the fourth position from the third position, and the moving speed of the irradiation position of the laser at the fourth position is zero.

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