Additive manufacturing device and additive manufacturing method

Abstract

The additive manufacturing apparatus (100) includes: a processing head (10); a beam nozzle (11) through which a beam emitted from the processing head (10) passes; a material supply unit (19) that supplies material to a workpiece; a first driving unit that moves a front end portion on the workpiece side among the materials relative to the workpiece; a second driving unit that moves the beam in a direction included in a reference plane that is a plane perpendicular to the central axis of the beam nozzle (11); and a control device (1) that determines the direction in which the beam is moved by the second driving unit based on the direction included in the reference plane and the traveling direction, which is the direction in which the front end portion travels relative to the workpiece, and controls the first driving unit and the second driving unit so that the beam can be moved in a manner different from the movement of the front end portion relative to the workpiece.

Description

Technical Field

[0001] The present invention relates to an additive manufacturing apparatus and an additive manufacturing method for manufacturing a three-dimensional object. Background Art

[0002] As one of the techniques for manufacturing a three-dimensional object, a technique of additive manufacturing (AM) is known. According to a directed energy deposition (DED) method, which is one of the plurality of methods in the additive manufacturing technique, an additive manufacturing apparatus forms a weld bead while supplying a material to a designated position and irradiating the material and the workpiece with a light beam. The weld bead is a solidified product obtained by solidifying the molten material on the workpiece. The additive manufacturing apparatus manufactures an object by sequentially laminating the weld beads.

[0003] In Patent Document 1, there is disclosed a DED-type additive manufacturing apparatus that supplies a wire of a metal material to a workpiece to manufacture an object.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2022-32283 Summary of the Invention

[0005] In an additive manufacturing apparatus, if the melting of the workpiece is insufficient, the wire may come into contact with the insufficiently melted part of the wire and the workpiece, and thus the wire may be bent. The likelihood of occurrence of this problem varies depending on the direction in which the front end portion on the workpiece side of the wire is moved. In the conventional additive manufacturing apparatus disclosed in Patent Document 1, the adjustment of the light beam corresponding to the change in the direction in which the front end portion of the wire is moved is not performed, and thus there is a problem that it is difficult to achieve stable processing by reducing the problem.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to obtain an additive manufacturing apparatus capable of achieving stable processing.

[0007] In order to solve the above problems and achieve the object, the additive manufacturing apparatus according to the present invention attaches a material melted by the irradiation of a light beam to a workpiece, thereby manufacturing a shaped object. The additive manufacturing apparatus according to the present invention includes: a processing head; a light beam nozzle through which the light beam emitted from the processing head passes; a material supply unit that supplies a material to the workpiece; a first drive unit that moves the front end portion on the workpiece side among the materials relative to the workpiece; a second drive unit that moves the light beam in a direction included in a reference plane that is a plane perpendicular to the central axis of the light beam nozzle; and a control device that determines the direction in which the light beam is moved by the second drive unit based on the direction included in the reference plane and the traveling direction in which the front end portion travels relative to the workpiece, and controls the first drive unit and the second drive unit so that the light beam can be moved in a manner different from the movement of the front end portion relative to the workpiece.

[0008] Effects of the Invention

[0009] The additive manufacturing apparatus according to the present invention has the effect of enabling stable processing. Description of the Drawings

[0010] Figure 1 It is a diagram showing a structural example of the additive manufacturing apparatus according to Embodiment 1.

[0011] Figure 2 It is a flowchart showing an example of the operation sequence of the additive manufacturing apparatus according to Embodiment 1.

[0012] Figure 3 It is a diagram showing a case where a shaped object is formed by the additive manufacturing apparatus according to Embodiment 1.

[0013] Figure 4 It is a diagram for explaining the movement of the laser beam in the additive manufacturing apparatus according to Embodiment 1.

[0014] Figure 5 It is a diagram showing a case where the laser beam is moved by the additive manufacturing apparatus according to Embodiment 1.

[0015] Figure 6 It is a diagram showing a case where the laser beam is moved by the light beam drive unit of the additive manufacturing apparatus according to Embodiment 2.

[0016] Figure 7 It is a first diagram for explaining the irradiation area where the laser beam is moved by the light beam drive unit of the additive manufacturing apparatus according to Embodiment 2.

[0017] Figure 8 It is a second diagram for explaining the irradiation area where the laser beam is moved by the light beam drive unit of the additive manufacturing apparatus according to Embodiment 2.

[0018] Figure 9 It is a diagram of a first modification example showing an irradiation area where a laser beam is moved by a beam driving unit of an additive manufacturing apparatus according to Embodiment 2.

[0019] Figure 10 It is a diagram of a second modification example showing an irradiation area where a laser beam is moved by a beam driving unit of an additive manufacturing apparatus according to Embodiment 2.

[0020] Figure 11 It is a diagram showing a case where a shaped object is formed by an additive manufacturing apparatus according to Embodiment 3.

[0021] Figure 12 It is a diagram for explaining the shape of a weld bead formed by an additive manufacturing apparatus according to Embodiment 3.

[0022] Figure 13 It is a diagram showing a case where a laser beam is moved by an additive manufacturing apparatus according to Embodiment 4.

[0023] Figure 14 It is a diagram showing a weld bead formed in Embodiment 4.

[0024] Figure 15 It is a diagram showing a weld bead formed in the comparative example of Embodiment 4.

[0025] Figure 16 It is a diagram showing a case where a shaped object is formed by an additive manufacturing apparatus according to Embodiment 5.

[0026] Figure 17 It is a first diagram showing a case where a laser beam is moved by a beam driving unit of an additive manufacturing apparatus according to Embodiment 5.

[0027] Figure 18 It is a second diagram showing a case where a laser beam is moved by a beam driving unit of an additive manufacturing apparatus according to Embodiment 5.

[0028] Figure 19 It is a diagram for explaining the first step of forming a bead-shaped weld bead by an additive manufacturing apparatus according to Embodiment 5.

[0029] Figure 20 It is a diagram for explaining the second step of forming a bead-shaped weld bead by an additive manufacturing apparatus according to Embodiment 5.

[0030] Figure 21 It is a diagram for explaining the third step of forming a bead-shaped weld bead by an additive manufacturing apparatus according to Embodiment 5.

[0031] Figure 22This is a diagram for explaining the fourth step of forming a beaded weld bead by the additive manufacturing apparatus according to Embodiment 5.

[0032] Figure 23 This is a diagram for explaining the fifth step of forming a beaded weld bead by the additive manufacturing apparatus according to Embodiment 5.

[0033] Figure 24 This is a diagram for explaining the sixth step of forming a beaded weld bead by the additive manufacturing apparatus according to Embodiment 5.

[0034] Figure 25 This is a diagram for explaining the seventh step of forming a beaded weld bead by the additive manufacturing apparatus according to Embodiment 5.

[0035] Figure 26 This is a diagram for explaining the eighth step of forming a beaded weld bead by the additive manufacturing apparatus according to Embodiment 5.

[0036] Figure 27 This is a diagram for explaining the ninth step of forming a beaded weld bead by the additive manufacturing apparatus according to Embodiment 5.

[0037] Figure 28 This is a diagram for explaining the tenth step of forming a beaded weld bead by the additive manufacturing apparatus according to Embodiment 5.

[0038] Figure 29 This is a diagram showing a structural example of the control circuit according to Embodiments 1 to 5.

[0039] Figure 30 This is a diagram showing a structural example of the dedicated hardware circuit according to Embodiments 1 to 5. Detailed Embodiments

[0040] Hereinafter, the additive manufacturing apparatus and the additive manufacturing method according to the embodiments will be described in detail based on the drawings.

[0041] Embodiment 1.

[0042] Figure 1 This is a diagram showing a structural example of the additive manufacturing apparatus 100 according to Embodiment 1. The additive manufacturing apparatus 100 is a machine tool that manufactures a shaped object by attaching a material melted by the irradiation of a light beam to a workpiece. In Embodiment 1, the light beam is the laser beam 24, and the material is the metal wire 5.

[0043] The additive manufacturing apparatus 100 is a DED (Directed Energy Deposition) type additive manufacturing apparatus. The additive manufacturing apparatus 100 forms a weld bead by supplying a wire material 5 to a designated position while irradiating the wire material 5 and the workpiece with a laser beam 24. By arranging a plurality of weld beads on a substrate 17, a layer of weld beads is formed. By laminating the layers of weld beads, a deposit 18 of weld beads is formed. As described above, the additive manufacturing apparatus 100 manufactures a three-dimensional shaped object by laminating weld beads. Figure 1 The shown substrate 17 is a plate. The substrate 17 can also be an object other than a plate. The workpiece is an object to which a molten material is added, and is the substrate 17 or the deposit 18.

[0044] The X-axis, Y-axis, and Z-axis are three mutually perpendicular axes. The X-axis and Y-axis are two horizontal axes. The Z-axis direction is the vertical direction. The direction of the arrow in the X-axis direction is defined as the positive X direction, and the direction opposite to the positive X direction is defined as the negative X direction. The direction of the arrow in the Y-axis direction is defined as the positive Y direction, and the direction opposite to the positive Y direction is defined as the negative Y direction. The direction of the arrow in the Z-axis direction is defined as the positive Z direction, and the direction opposite to the positive Z direction is defined as the negative Z direction.

[0045] A laser oscillator 2 as a light beam source outputs a laser beam 24. The laser beam 24 output from the laser oscillator 2 is transmitted to a beam driving unit 20 through an optical fiber cable 3 as an optical transmission path. The beam driving unit 20 is mounted on a processing head 10. Details of the beam driving unit 20 will be described later. The laser beam 24 is incident on the processing head 10 through the beam driving unit 20. An optical system such as a collimation optical system or a focusing optical system is disposed inside the processing head 10. The illustration of the optical system is omitted. The laser oscillator 2, the optical fiber cable 3, and the processing head 10 constitute an irradiation unit that irradiates the workpiece with the laser beam 24.

[0046] A beam nozzle 11 through which the laser beam 24 emitted from the processing head 10 passes and a gas nozzle 13 for ejecting a shielding gas are provided on the processing head 10. The central axis of the beam nozzle 11 coincides with the optical axis of the optical system. The laser beam 24 passes through the optical system inside the processing head 10 and is emitted from the processing head 10 through the beam nozzle 11. The laser beam 24 is transmitted from the beam nozzle 11 to the workpiece. The laser beam 24 is a heat source for melting the wire material 5.

[0047] The gas nozzle 13 ejects an inert gas 25 as a shielding gas toward the processing area 34 being processed. By ejecting the inert gas 25, the oxidation of the weld bead is reduced, and the formed weld bead is cooled. A gas supply device 7 supplies the inert gas 25. The inert gas 25 is supplied from the gas supply device 7 to the gas nozzle 13 through a pipe 8.

[0048] The direction of the central axis of the beam nozzle 11 is the Z-axis direction. Figure 1In the illustrated structural example, the central axis of the gas nozzle 13 coincides with the central axis of the beam nozzle 11. That is, the gas nozzle 13 is provided on the same axis as the beam nozzle 11. The gas nozzle 13 jets an inert gas 25 vertically downward. In addition, the central axis of the gas nozzle 13 may be inclined with respect to the central axis of the beam nozzle 11. In this case, the gas nozzle 13 jets the inert gas 25 obliquely downward.

[0049] A wire spool 6 as a supply source of the wire 5 is installed in the additive manufacturing apparatus 100. The wire 5 is wound around the wire spool 6. The wire spool 6 rotates along with the driving of a rotary motor 4 that is a servo motor. As the wire spool 6 rotates, the wire 5 is drawn out from the wire spool 6. The wire 5 drawn out from the wire spool 6 passes through the wire nozzle 12 and is supplied to the workpiece. Thus, the wire 5 is supplied to the irradiation position of the laser beam 24. In addition, by rotating the rotary motor 4 in the direction opposite to the case of drawing out the wire 5, the drawn-out wire 5 is pulled back. Thus, the wire 5 is pulled out from the irradiation position of the laser beam 24. The rotary motor 4, the wire spool 6, and the wire nozzle 12 constitute a material supply unit 19 that supplies a material to the workpiece. The material supply unit 19 supplies the wire 5 such that the front end portion of the wire 5 coincides with a designated processing point. The processing point is set as a position on the processing path.

[0050] In addition, an actuating mechanism for drawing out the wire 5 from the wire spool 6 may be provided in the wire nozzle 12. By providing at least one of the actuating mechanisms of the rotary motor 4 and the wire nozzle 12 in the additive manufacturing apparatus 100, the wire 5 can be supplied to the workpiece. In Figure 1 the illustration of the actuating mechanism of the wire nozzle 12 is omitted.

[0051] In Figure 1 the illustrated structural example, the central axis of the wire 5 supplied from the wire nozzle 12 is inclined with respect to the central axis of the beam nozzle 11. The direction of the central axis of the wire 5 is an inclined direction between the Z-axis direction and the X-axis direction.

[0052] The wire nozzle 12 is fixed to the processing head 10. In Figure 1 the illustration of the elements for fixing the wire nozzle 12 to the processing head 10 is omitted. Since the beam nozzle 11, the wire nozzle 12, and the gas nozzle 13 are integrated with the processing head 10, the positional relationship among the beam nozzle 11, the wire nozzle 12, and the gas nozzle 13 is uniquely determined. That is, the relative positions of the beam nozzle 11, the wire nozzle 12, and the gas nozzle 13 are fixed.

[0053] The machining head driving unit 14 moves the machining head 10 in each of the X-axis direction, the Y-axis direction, and the Z-axis direction. The machining head driving unit 14 has an action mechanism that causes the machining head 10 to perform translational motion in each of the three-axis directions. The machining head driving unit 14 has a servo motor that moves the machining head 10 in the X-axis direction, a servo motor that moves the machining head 10 in the Y-axis direction, and a servo motor that moves the machining head 10 in the Z-axis direction. Illustration of each servo motor is omitted.

[0054] The additive manufacturing apparatus 100 moves the processing head 10 relative to the workpiece, thereby moving the irradiation position of the laser beam 24. The additive manufacturing apparatus 100 may also move the worktable 15 relative to the processing head 10, thereby moving the irradiation position of the laser beam 24. In this case, the additive manufacturing apparatus 100 moves the worktable 15 relative to the processing head 10 by moving at least one of the three-axis directions.

[0055] The relative positions of the beam nozzle 11 and the wire nozzle 12 are fixed, so the front end of the wire 5 also moves in conjunction with the movement of the irradiation position driven by the processing head driving unit 14. The processing head driving unit 14 constitutes a first driving unit that moves the front end of the workpiece side of the wire 5 relative to the workpiece. When the table 15 moves relative to the processing head 10, the table 15 constitutes the first driving unit.

[0056] The rotating mechanism 16 is an operating mechanism capable of rotating the table 15 about a first axis and about a second axis perpendicular to the first axis. Figure 1 In the rotating mechanism 16 shown, the first axis is an axis parallel to the X axis, and the second axis is an axis parallel to the Y axis. The rotating mechanism 16 has a servo motor that rotates the worktable 15 around the first axis and a servo motor that rotates the worktable 15 around the second axis. The rotating mechanism 16 drives the servo motors to rotate the worktable 15 around the two axes. The servo motors are not shown in the figure.

[0057] The additive manufacturing apparatus 100 changes the posture of the workpiece by rotating the table 15 using the rotating mechanism 16. The additive manufacturing apparatus 100 can change the posture of the workpiece to a posture suitable for processing.

[0058] The additive manufacturing apparatus 100 includes a hot wire power source 21, a current cable 22, and an insulator 23. The hot wire power source 21 is a power source that generates a high current of about 200 A to 500 A. One of the current cables 22 connects the hot wire power source 21 and the wire nozzle 12. The other current cable 22 connects the hot wire power source 21 and the substrate 17. When the current from the hot wire power source 21 flows through the current cable 22 and through the wire nozzle 12, a current flows through the wire 5 in contact with the wire nozzle 12. In addition, the worktable 15 and the substrate 17 are insulated from each other by the insulator 23.

[0059] Since the wire 5 has a resistance, Joule heat is generated in the wire 5 by flowing a current through the wire 5. The temperature of the wire 5 rises due to the Joule heat. In this case, the laser beam 24 and the Joule heat serve as heat sources for melting the wire 5. The additive manufacturing apparatus 100 adds the Joule heat to the heating by the laser beam 24, thereby promoting the melting of the wire 5 and enabling an increase in the processing speed. In order to increase the processing speed, it is preferable to heat the wire 5 by the Joule heat up to near the melting point of the wire 5.

[0060] A beam driving unit 20 as the second driving unit moves the laser beam 24 in a direction included in the reference plane. The reference plane is a plane perpendicular to the central axis of the beam nozzle 11 and is a virtual plane. The reference plane is the XY plane. For example, the reference plane is set based on the coordinate system of the additive manufacturing apparatus 100. The beam driving unit 20 has an actuating mechanism that moves the laser beam 24 in a direction included in the reference plane.

[0061] The beam driving unit 20 includes, for example, an electric scanner that moves the laser beam 24 in the X-axis direction and an electric scanner that moves the laser beam 24 in the Y-axis direction. The electric scanner has a mirror that deflects the laser beam 24. The electric scanner rotates the mirror within a specific swing angle range, thereby moving the laser beam 24. Alternatively, the beam driving unit 20 has a condenser lens that condenses the laser beam 24, and moves the laser beam 24 by moving the condenser lens in the X-axis direction and the Y-axis direction. The structure of the beam driving unit 20 is not limited to the above structure and can be any structure.

[0062] The additive manufacturing apparatus 100 includes a control device 1 that controls the entire additive manufacturing apparatus 100. The control device 1 controls the additive manufacturing apparatus 100 according to a machining program. The control device 1 is, for example, a Numerical Control (NC) device. In Embodiment 1, the machining program is an NC program.

[0063] Specify the machining path in the NC program. The control device 1 analyzes the machining path based on the NC program. The control device 1 generates various instructions according to the machining path and the machining conditions set for machining. The control device 1 generates a set of interpolation points per unit time on the machining path, that is, position instructions. The control device 1 outputs the position instructions to the machining head drive unit 14, thereby controlling the machining head drive unit 14.

[0064] The control device 1 generates an instruction corresponding to the condition of the beam intensity, that is, a beam output instruction. The control device 1 outputs the beam output instruction to the laser oscillator 2, thereby controlling the laser oscillator 2. The control device 1 generates an instruction corresponding to the condition of the supply amount of the wire 5, that is, a material supply instruction. The control device 1 outputs the material supply instruction to the rotary motor 4, thereby controlling the rotary motor 4. The material supply instruction can be an instruction corresponding to the condition of the supply speed of the wire 5. The supply speed is the speed of the wire 5 from the wire spool 6 toward the machining point. The supply speed represents the supply amount of the material per unit time.

[0065] The control device 1 generates an instruction corresponding to the condition of the supply amount of the gas, that is, a gas supply instruction. The control device 1 outputs the gas supply instruction to the gas supply device 7, thereby controlling the amount of the inert gas 25 supplied from the gas supply device 7 to the gas nozzle 13. The control device 1 generates a rotation instruction for making the posture of the workpiece suitable for machining. The control device 1 outputs the rotation instruction to the rotation mechanism 16, thereby controlling the rotation mechanism 16.

[0066] The control device 1 generates an instruction for the movement of the laser beam 24, that is, a beam movement instruction. The control device 1 outputs the beam movement instruction to the beam drive unit 20, thereby controlling the beam drive unit 20. The control device 1 generates a current instruction for heating the wire 5 to a desired temperature. The control device 1 outputs the current instruction to the hot wire power supply 21, thereby controlling the hot wire power supply 21.

[0067] The control device 1 determines the direction of movement of the laser beam 24 based on the traveling direction of the front end of the wire 5, and controls the machining head drive unit 14 as the first drive unit and the beam drive unit 20 as the second drive unit so that the laser beam 24 can be moved in a manner different from the movement of the front end of the wire 5 relative to the workpiece. This traveling direction is the direction included in the reference plane and is the direction in which the front end of the wire 5 travels relative to the workpiece. The movement of the laser beam 24 in a manner different from the movement of the front end of the wire 5 means that it is independent of the situation where the laser beam 24 moves together with the front end of the wire 5 by the movement of the machining head 10, and the laser beam 24 moves relative to the front end of the wire 5.

[0068] As described above, the wire nozzle 12 and the processing head 10 are integrated. Therefore, the traveling direction of the front end portion of the wire 5 is also the direction in which the processing head 10 travels relative to the workpiece. The control device 1 controls the processing head drive unit 14 regarding the traveling direction of the front end portion of the wire 5 as the traveling direction of the processing head 10. That is, it can be said that the control device 1 determines the direction in which the laser beam 24 moves based on the traveling direction of the processing head 10.

[0069] Next, the operation of the additive manufacturing apparatus 100 will be described. Figure 2 It is a flowchart showing an example of the operation sequence of the additive manufacturing apparatus 100 according to the first embodiment.

[0070] In step S1, the additive manufacturing apparatus 100 reads the traveling direction of the processing head 10 from the NC program in the control device 1. The control device 1 analyzes the machining path based on the NC program. The control device 1 obtains the traveling direction of the processing head 10 with respect to each position for each control cycle, that is, each machining point, among the machining paths.

[0071] In step S2, the control device 1 determines the irradiation position of the laser beam 24 based on the traveling direction read in step S1. The method for determining the irradiation position will be described later.

[0072] In step S3, the additive manufacturing apparatus 100 sets the position of the laser beam 24 at the irradiation position determined in step S2 and starts the formation of the weld bead. In step S4, the additive manufacturing apparatus 100 reads the traveling direction of the processing head 10 from the NC program in the control device 1.

[0073] In step S5, the control device 1 determines whether there is a change in the traveling direction of the processing head 10. The control device 1 determines whether the traveling direction read in step S4 has changed from the traveling direction read in step S1. When it is determined in step S5 that there is no change in the traveling direction (step S5, No), the additive manufacturing apparatus 100 advances the sequence to step S7.

[0074] On the other hand, when it is determined in step S5 that there is a change in the traveling direction (step S5, Yes), in step S6, the control device 1 determines the irradiation position of the laser beam 24 based on the traveling direction read in step S4. The additive manufacturing apparatus 100 sets the position of the laser beam 24 at the irradiation position determined in step S6 and continues the formation of the weld bead. If step S6 is completed, the additive manufacturing apparatus 100 returns the sequence to step S4.

[0075] In step S7, the control device 1 determines whether the formation of the bead started in step S3 is completed. When the formation of the bead is not completed (step S7, No), the additive manufacturing device 100 returns the sequence to step S4. On the other hand, when the formation of the bead is completed (step S7, Yes), the additive manufacturing device 100 ends Figure 2 the operations involved in the sequence shown. The additive manufacturing device 100 forms each bead constituting the shaped object through Figure 2 the operations involved in the sequence shown.

[0076] The additive manufacturing device 100 determines the irradiation position of the laser beam 24 before the traveling direction of the processing head 10 changes, and changes the irradiation position of the laser beam 24 in accordance with the timing of the change in the traveling direction of the processing head 10. To this end, the control device 1 always reads the NC program in advance and determines the irradiation position of the laser beam 24. Reading in advance means that in the analysis of the NC program, analysis related to processing to be executed after the currently executed processing is performed.

[0077] The speed of the processing head 10 when forming the bead is, for example, about 300 mm / min to 3000 mm / min. When changing the irradiation position of the laser beam 24 in units of 1 mm in the processing path, the control device 1 controls to change the irradiation position of the laser beam 24 at intervals of approximately 20 msec.

[0078] In addition, the control device 1 may also preset the irradiation position of the laser beam 24 with respect to the processing path generated by a Computer Aided Manufacturing (CAM) device, and change the irradiation position based on the setting. For example, when it is difficult to control the irradiation position of the laser beam 24 at intervals of approximately 20 msec while reading the traveling direction of the processing head 10 from the NC program, the control device 1 can appropriately change the irradiation position by presetting the irradiation position.

[0079] Figure 3 is a diagram showing a case where a shaped object is formed by the additive manufacturing device 100 according to Embodiment 1. In Figure 3 it schematically shows a case where a bead 35 is formed on a base material 17 as an object to be processed. The processing area 34 is an area where processing is performed, and is set as an area centered on the processing point. In Figure 3 the processing point is a position on the surface 32 of the base material 17 and the intersection of the central axis CL of the beam nozzle 11 and the central axis CW of the wire 5 supplied from the wire nozzle 12. In Figure 3 the illustration of the beam nozzle 11 is omitted. The laser beam 24 is irradiated into the processing area 34. The wire 5 is supplied to the processing point.

[0080] By irradiating with the laser beam 24, a molten pool 33 is formed in a portion within the processing area 34 in the surface 32. The melt 31 of the wire 5 is placed in the molten pool 33. The melt 31 and the molten pool 33 are integrated with each other, and the melt 31 and the molten pool 33 solidify, thereby forming a weld bead 35 joined to the base material 17.

[0081] The arrow 36 indicates the traveling direction of the processing head 10. While moving the processing head 10 in the direction of the arrow 36, the weld bead 35 is formed, thereby forming a linear weld bead 35 having the direction of the arrow 36 as the longitudinal direction on the base material 17. The arrow 37 indicates the direction in which the laser beam 24 is moved. In Figure 3 the example shown, the direction in which the laser beam 24 is moved is a direction perpendicular to the traveling direction of the processing head 10. In Figure 3 the irradiation position of the laser beam 24 is a position shifted from the processing point in the direction of the arrow 37.

[0082] Next, the details related to the movement of the laser beam 24 implemented by the light beam driving unit 20 will be described. Figure 4 is a diagram for explaining the movement of the laser beam 24 in the additive manufacturing apparatus 100 according to the first embodiment.

[0083] In Figure 4 angles such as 0°, 45°, ···, 315° represent the traveling direction of the processing head 10. The angles representing the traveling direction of the processing head 10 are based on the positive X direction. The light spot 38 is the cross-section of the laser beam 24 on the reference plane. The arrow 39 indicates the direction in which the laser beam 24 is moved. Figure 4 shows the case where the irradiation position of the laser beam 24 changes corresponding to the traveling direction of the processing head 10.

[0084] When the traveling direction is 0° and when the traveling direction is 180°, the center of the light spot 38 coincides with the position of the front end portion of the wire 5. When the traveling direction is other than 0° or 180°, the center of the light spot 38 is displaced forward in the traveling direction. During the period when the traveling direction gradually changes from 0° through 45° to 90°, the direction of the arrow 39, that is, the direction in which the light spot 38 is displaced gradually changes from the positive X direction to the positive Y direction. In addition, the displacement amount of the center of the light spot 38 from the front end portion of the wire 5 gradually increases from zero. When the traveling direction is 90°, the displacement amount becomes the maximum.

[0085] During the period when the traveling direction gradually changes from 90° through 135° to 180°, the direction in which the light spot 38 is displaced changes from the positive Y direction to the negative X direction. In addition, the displacement amount gradually decreases from the maximum value of the displacement amount. When the traveling direction is 180°, the displacement amount becomes zero.

[0086] During the period in which the traveling direction gradually changes from 180° to 225° and then to 270°, the direction of displacement of the light spot 38 changes from the negative X direction to the negative Y direction. In addition, the displacement amount gradually increases from zero. When the traveling direction is 270°, the displacement amount becomes the maximum. During the period in which the traveling direction gradually changes from 270° to 315° and then to 360° (i.e., 0°), the direction of displacement of the light spot 38 changes from the negative Y direction to the positive X direction. In addition, the displacement amount gradually decreases from the maximum value of the displacement amount. When the traveling direction is 0°, the displacement amount becomes zero.

[0087] The control device 1 presets the relationship between the traveling direction of the processing head 10 and the direction in which the laser beam 24 is moved as described above. Based on this relationship, the control device 1 obtains the direction in which the laser beam 24 is moved by the beam driving unit 20 according to the traveling direction of the processing head 10.

[0088] In the first embodiment, as the direction in which the laser beam 24 is moved by the beam driving unit 20, the control device 1 sets the same direction as the traveling direction of the processing head 10 as the direction in which the laser beam 24 is moved by the beam driving unit 20. Thus, the beam driving unit 20 moves the laser beam 24 forward in the traveling direction of the processing head 10.

[0089] In addition, the control device 1 presets the relationship between the traveling direction of the processing head 10 and the displacement amount of the laser beam 24 as described above. Based on this relationship, the control device 1 obtains the displacement amount of the laser beam 24 generated by the beam driving unit 20 according to the traveling direction of the processing head 10. As described above, the control device 1 adjusts the displacement amount of the laser beam 24 starting from the front end of the wire 5 according to the traveling direction of the processing head 10.

[0090] Figure 5 This is a diagram showing the situation in which the laser beam 24 is moved by the additive manufacturing apparatus 100 according to the first embodiment. In Figure 5 it, the case where the traveling direction of the processing head 10 is 90° is shown as an example.

[0091] As described above, when the traveling direction of the processing head 10 is 90°, the displacement amount of the light spot 38 becomes the maximum. As Figure 5 shown, by making the end of the wire 5 opposite to the traveling direction of the processing head 10 coincide with the end of the light spot 38 opposite to the traveling direction of the processing head 10, the displacement amount of the light spot 38 becomes the maximum.

[0092] In addition, when the traveling direction of the processing head 10 is 270°, the end of the wire 5 opposite to the traveling direction of the processing head 10 is also made to coincide with the end of the light spot 38 opposite to the traveling direction of the processing head 10. By setting it to this state, the displacement amount of the light spot 38 becomes the maximum.

[0093] In Figure 5 , the diameter of the wire 5 is set to 1.2 mm, and the diameter of the laser beam 24 is set to 3.0 mm. The distance between the central axis CW of the wire 5 and the center of the light spot 38 is 0.9 mm. That is, in the state shown in Figure 5 , the laser beam 24 moves 0.9 mm forward from the front end of the wire 5.

[0094] When the traveling direction of the processing head 10 gradually changes from 0° to 90°, for each 1° change in the traveling direction of the processing head 10, the displacement amount is increased by 0.01 mm. Thus, when the traveling direction of the processing head 10 gradually changes from 0° to 90°, the control device 1 increases the displacement amount of the laser beam 24 step by step. When the traveling direction of the processing head 10 gradually changes from 90° to 180°, for each 1° change in the traveling direction of the processing head 10, the displacement amount is increased by 0.01 mm. Thus, when the traveling direction of the processing head 10 gradually changes from 90° to 180°, the control device 1 decreases the displacement amount of the laser beam 24 step by step.

[0095] When the traveling direction of the processing head 10 gradually changes from 180° to 270°, the control device 1 increases the displacement amount of the laser beam 24 step by step in the same manner as when changing from 0° to 90°. When the traveling direction of the processing head 10 gradually changes from 270° to 360°, the control device 1 decreases the displacement amount of the laser beam 24 step by step in the same manner as when changing from 90° to 180°.

[0096] In the additive manufacturing apparatus 100, the front end of the wire 5 comes into contact with an insufficiently melted portion of the workpiece, and thus the wire 5 may be bent or damaged. Or, sometimes the insufficiently melted portion becomes an obstacle and hinders the movement of the front end in the direction of the reference plane. The degree of occurrence of the problems caused by the existence of the above-mentioned insufficiently melted portion varies according to the direction in which the front end of the wire 5 moves. The closer the traveling direction of the front end of the wire 5 is to perpendicular to the central axis CW of the wire 5, the more likely the above-mentioned problems are to occur.

[0097] In the first embodiment, the additive manufacturing apparatus 100 moves the laser beam 24 by the beam driving unit 20, and thus adjusts the irradiation position of the laser beam 24 with respect to the change in the direction in which the front end of the wire 5 moves. The additive manufacturing apparatus 100 moves the laser beam 24 forward in the traveling direction of the processing head 10, and thus promotes the melting of the workpiece in front of the front end of the wire 5 that moves. The additive manufacturing apparatus 100 promotes the melting of the workpiece in front of the front end of the wire 5 that moves, and thus can reduce the above-mentioned problems. Thus, the additive manufacturing apparatus 100 can perform stable processing.

[0098] The closer the traveling direction of the front end portion of the wire 5 is to being perpendicular to the central axis CW of the wire 5, the greater the displacement amount of the laser beam 24 by the additive manufacturing apparatus 100. Thus, when the problem is more likely to occur, the melting of the workpiece is promoted more, and the additive manufacturing apparatus 100 can more effectively reduce the problem. In addition, the additive manufacturing apparatus 100 can perform stable processing regardless of the traveling direction of the front end portion of the wire 5.

[0099] By promoting the melting of the workpiece in front, the additive manufacturing apparatus 100 also prevents the molten metal flow from being obstructed by the wire 5 and the bead width from becoming thinner than expected. Thus, the additive manufacturing apparatus 100 can form a bead 35 with a desired bead width.

[0100] According to Embodiment 1, the additive manufacturing apparatus 100 determines the direction in which the laser beam 24 is moved by the second driving unit based on the traveling direction of the front end portion of the wire 5. The additive manufacturing apparatus 100 controls the first driving unit and the second driving unit so that the laser beam 24 can be moved in a manner different from the movement of the front end portion of the wire 5 relative to the workpiece. The additive manufacturing apparatus 100 can reduce the problems caused by the contact between the wire 5 and the insufficiently melted portion and can achieve stable processing. As described above, the additive manufacturing apparatus 100 has the effect of being able to achieve stable processing.

[0101] Embodiment 2.

[0102] In Embodiment 2, an example in which the irradiation area of the laser beam 24 is enlarged by moving the laser beam 24 at high speed is described. The structure of the additive manufacturing apparatus 100 according to Embodiment 2 is the same as the structure of the additive manufacturing apparatus 100 according to Embodiment 1. In Embodiment 2, the same reference numerals are given to the same structural elements as those in the above Embodiment 1, and the operations different from those in Embodiment 1 are mainly described.

[0103] Figure 6 FIG. shows a case where the laser beam 24 is moved by the beam driving unit 20 of the additive manufacturing apparatus 100 according to Embodiment 2. In Figure 6 an example in which the laser beam 24 is moved in an irradiation area 40 wider than the spot of the laser beam 24 in the base material 17 as the workpiece is shown. In Figure 6 a case where the laser beam 24 is moved in the irradiation area 40 is schematically shown.

[0104] In Embodiment 2, the beam driving unit 20 moves the laser beam 24 at a high speed compared to the speed at which the front end portion of the wire 5 is moved, thereby enlarging the irradiation area 40 of the laser beam 24 in the workpiece compared to the spot of the laser beam 24. In Figure 6In [the figure], arrow 41 shows an example of the path for moving the laser beam 24 in the irradiation area 40.

[0105] Figure 7 This is the first figure for explaining the irradiation area 40 in which the laser beam 24 is moved by the beam driving unit 20 of the additive manufacturing apparatus 100 according to Embodiment 2. Figure 8 This is the second figure for explaining the irradiation area 40 in which the laser beam 24 is moved by the beam driving unit 20 of the additive manufacturing apparatus 100 according to Embodiment 2. Figure 7 and Figure 8 The shown irradiation area 40 is approximately rectangular in shape, and is a shape in which each of the four corners is deformed in a way that has rounded corners.

[0106] In Figure 7 an example of changing the orientation of the irradiation area 40 corresponding to a change in the traveling direction of the processing head 10 is shown. In Figure 7 the shown example, the orientation of the irradiation area 40 is changed such that the long side of the rectangle is perpendicular to the traveling direction of the front end portion of the wire 5. In Embodiment 2, the control device 1 determines the direction in which the laser beam 24 is moved based on the traveling direction of the front end portion of the wire 5, thereby changing the orientation of the irradiation area 40 corresponding to the traveling direction of the front end portion of the wire 5.

[0107] The control device 1 controls the processing head driving unit 14 as the first driving unit and the beam driving unit 20 as the second driving unit so that the laser beam 24 can be moved in a manner different from the movement of the front end portion of the wire 5 relative to the workpiece. Thus, the control device 1 moves the laser beam 24 at a high speed compared to the speed at which the front end portion of the wire 5 is moved. In addition, the control device 1 moves the laser beam 24 in the direction determined corresponding to the traveling direction of the front end portion of the wire 5.

[0108] In Figure 8 [the figure], arrow 41 shows an example of the path for moving the laser beam 24 in the irradiation area 40. The light spot 42 of the laser beam 24 is a circle smaller than the irradiation area 40. In Figure 8 the case of the shown example, the beam driving unit 20 reciprocates the light spot 42 multiple times in the direction of the long side of the rectangle, thereby moving the light spot 42 over the entire irradiation area 40. The additive manufacturing apparatus 100 moves the processing head 10, thereby moving the irradiation area 40 in the workpiece.

[0109] The additive manufacturing apparatus 100 moves the light spot 42 at a high speed compared to the movement of the processing head 10, thereby approximately expanding the light spot 42 and irradiating the laser beam 24. The weld bead 35 is formed in the irradiation region 40. The additive manufacturing apparatus 100 can form the weld bead 35 in the irradiation region 40 that is larger than the light spot 42. The additive manufacturing apparatus 100 can achieve the same processing as the case where the light spot 42 is expanded to the irradiation region 40 by the movement of the laser beam 24 by the beam driving unit 20. In addition, the path of the laser beam 24 in the irradiation region 40 is arbitrary and is not limited to the path indicated by the arrow 41 in Figure 8 the figure.

[0110] For example, by moving the laser beam 24 at a frequency greater than or equal to 1 kHz, the irradiation region 40 in which the light spot 42 is approximately expanded is obtained. When the length of the irradiation region 40 in the longitudinal direction of the irradiation region 40 is 6 mm, if the laser beam 24 reciprocates at an amplitude of 3 mm and a frequency of 1 kHz, the moving speed of the laser beam 24 becomes approximately 20 m / sec. However, even when the moving speed of the laser beam 24 is slower than 20 m / sec, the irradiation region 40 in which the light spot 42 is approximately expanded can be obtained. In the case of this example, even if the moving speed of the laser beam 24 is slower than 20 m / sec, if the moving speed of the laser beam 24 is sufficiently faster than the moving speed of the processing head 10, the irradiation region 40 can be obtained. The moving speed of the laser beam 24 being sufficiently faster than the moving speed of the processing head 10 means that the energy capable of obtaining the molten pool 33 by moving the laser beam 24 can be imparted to the irradiation region 40. The additive manufacturing apparatus 100 can obtain the irradiation region 40 in which the light spot 42 is approximately expanded by setting the moving speed of the laser beam 24 to about 10 to 20 times or more the moving speed of the processing head 10.

[0111] The additive manufacturing apparatus 100 forms the irradiation region 40 in which the light spot 42 is approximately expanded, thereby being able to form the weld bead 35 having a width of about 5 to 10 times the diameter of the wire 5. The additive manufacturing apparatus 100 forms the irradiation region 40 by the movement of the laser beam 24, thereby being able to increase the energy density of the laser beam 24 compared to the case of expanding the diameter of the laser beam 24. Therefore, when the additive manufacturing apparatus 100 forms the weld bead 35 having a width wider than the diameter of the wire 5, the processing speed can be increased compared to the case of expanding the diameter of the laser beam 24.

[0112] For example, if the case where the irradiation area 40 is a rectangle of 2 mm × 8 mm is compared with a circular light beam with a diameter of 8 mm, the energy density in the case of the rectangle is 3.14 times greater. The circular light beam is the laser beam 24 whose cross-section perpendicular to the central axis of the laser beam 24 is circular. When the irradiation area 40 is rectangular, the irradiation area 40 has anisotropy. Therefore, regardless of the traveling direction of the processing head 10, if the orientation of the irradiation area 40 on the reference plane is constant, the traveling direction of the processing head 10 changes, and accordingly, the width of the weld bead 35 also changes. In the second embodiment, as described above, the orientation of the irradiation area 40 can be changed corresponding to the traveling direction. Therefore, the additive manufacturing apparatus 100 can form a weld bead 35 with a constant width while changing the traveling direction of the processing head 10.

[0113] The irradiation area 40 that approximately expands the light spot 42 is not limited to a rectangle such as the one described above, and can also be a shape other than a rectangle. The additive manufacturing apparatus 100 can set the irradiation area 40 to any shape by moving the laser beam 24.

[0114] Figure 9 FIG. is a diagram showing a first modification example of the irradiation area 40 in which the laser beam 24 is moved by the beam driving unit 20 of the additive manufacturing apparatus 100 according to the second embodiment. As the irradiation area 43 which is the first modification example of the irradiation area 40, it is a shape in which one long side of a rectangle is changed to a curve, and is the same shape as the cross-section of a convex lens. In Figure 9 an example is shown in which the orientation of the irradiation area 43 is changed corresponding to the change in the traveling direction of the processing head 10. In Figure 9 the example shown, the orientation of the irradiation area 43 is changed such that the length direction of the shape of the irradiation area 43 is perpendicular to the traveling direction of the front end portion of the wire 5.

[0115] In Figure 9In the example shown, when the traveling direction is 0° and when the traveling direction is 180°, the center of the irradiation area 43 coincides with the position of the front end portion of the wire 5. When the traveling direction is other than 0° or 180°, the center of the irradiation area 43 is displaced forward in the traveling direction. When the traveling direction is 90° and when the traveling direction is 270°, the displacement amount by which the center of the irradiation area 43 is moved from the front end portion of the wire 5 becomes the largest. By making the end of the wire 5 opposite to the traveling direction of the processing head 10 coincide with the end of the irradiation area 43 opposite to the traveling direction of the processing head 10, the displacement amount of the irradiation area 43 becomes the largest. As described above, the light beam driving unit 20 moves the irradiation area 43 forward in the traveling direction of the front end portion of the wire 5. That is, the light beam driving unit 20 moves the laser beam 24 forward in the traveling direction. In addition, the control device 1 adjusts the displacement amount of the center of the irradiation area 43 starting from the front end portion of the wire 5 according to the traveling direction of the front end portion of the wire 5.

[0116] In addition, in Figure 9 the example shown, when the traveling direction is 0°, the portion of the outer shape of the irradiation area 43 corresponding to the plane opposite to the convex surface of the convex lens faces forward in the traveling direction. On the other hand, when the traveling direction is 180°, this portion of the irradiation area 43 faces backward in the traveling direction. When the traveling direction is 135° and when the traveling direction is 225°, respectively, in the same manner as when the traveling direction is 180°, this portion of the irradiation area 43 faces backward in the traveling direction. The additive manufacturing device 100 adjusts the orientation of the irradiation area 43 in the above-described manner when the traveling direction is between 135° and 180°. Through this adjustment, the additive manufacturing device 100 sufficiently melts the workpiece in the portion of the irradiation area 43 where the laser beam 24 is less blocked by the wire 5. The additive manufacturing device 100 sufficiently melts the workpiece through the adjustment of the irradiation area 43 as described above, thereby enabling a bead 35 with a desired bead width to be formed.

[0117] The additive manufacturing device 100 promotes the melting of the workpiece in front of the front end portion of the wire 5 that is moving, thereby being able to reduce problems such as bending of the wire 5, damage to the wire 5, or obstruction of the movement of the wire 5. Thereby, the additive manufacturing device 100 can perform stable processing. By setting the shape of the irradiation area 43 to a shape deformed from a rectangle, the change in the area of the portion of the wire 5 irradiated by the laser beam 24 becomes smaller. The change in this area corresponding to the change in the traveling direction of the processing head 10 becomes smaller, so the melting of the wire 5 is stable. Since the melting of the wire 5 is stable in the additive manufacturing device 100, a bead 35 with a desired width can be formed with high precision.

[0118] Figure 10FIG. is a diagram showing a second modification example of the irradiation region 40 in which the laser beam 24 is moved by the light beam driving unit 20 of the additive manufacturing apparatus 100 according to the second embodiment. The irradiation region 44 as the second modification example of the irradiation region 40 is a so-called horseshoe shape. In Figure 10 an example is shown in which the shape of the irradiation region 44 changes corresponding to a change in the traveling direction of the processing head 10. In Figure 10 the example shown, the shape of the irradiation region 44 changes so that the area of the portion of the wire 5 irradiated with the laser beam 24 becomes constant.

[0119] Regardless of the traveling direction of the processing head 10, the area of the portion of the wire 5 irradiated with the laser beam 24 is constant, whereby the melting of the wire 5 is stable. The additive manufacturing apparatus 100 appropriately changes the shape of the irradiation region 44, whereby both the front end on the traveling direction side of the processing head 10 and the rear end on the traveling direction side of the processing head 10 in the wire 5 can be sufficiently melted. Since the melting of the wire 5 is stable in the additive manufacturing apparatus 100, a weld bead 35 having a desired width can be formed with high precision. The additive manufacturing apparatus 100 appropriately changes the shape of the irradiation region 44, whereby the area of the portion of the wire 5 irradiated with the laser beam 24 can be set to an arbitrary area. The additive manufacturing apparatus 100 can arbitrarily set the area of the portion of the wire 5 irradiated with the laser beam 24 corresponding to the desired amount of the molten material.

[0120] As exemplified in the second embodiment, the additive manufacturing apparatus 100 appropriately sets the path along which the laser beam 24 is moved by the light beam driving unit 20, whereby the irradiation region 40 can be set to an arbitrary shape. The irradiation region 40 can be, for example, a circle having a diameter larger than the diameter of the laser beam 24. By appropriately setting the shape of the irradiation region 40, the additive manufacturing apparatus 100 can easily form a weld bead 35 having an arbitrary width. The additive manufacturing apparatus 100 can form a weld bead 35 having an arbitrary width without increasing the diameter of the laser beam 24. That is, the additive manufacturing apparatus 100 can form a weld bead 35 having an arbitrary width using a laser beam 24 having a small diameter.

[0121] Here, the advantages of using a laser beam 24 having a small diameter will be described. The first advantage is that, as described above, the shape of the irradiation region 40 can be appropriately set, whereby a weld bead 35 having a desired width can be formed with high precision. The second advantage is that the energy density of the laser beam 24 can be increased, whereby a high-reflection material such as copper, gold, or silver can be used as a material to form a shaped object.

[0122] The following formula (1) is the temperature rise formula during single-pulse processing with a circular heat source. In formula (1), θ represents temperature, A represents the heat absorption rate, P represents the average output, a represents the radius of the light spot, K represents the thermal conductivity. Additionally, J0 represents the Bessel function of the first kind of order 0, J1 represents the Bessel function of the first kind of order 1, r represents the measurement distance, and t represents the irradiation time. According to this temperature rise formula, for example, it is known that when melting the surface of gold, a beam intensity of approximately 3 MW / cm 2 is required. If the laser output is set to 6 kW, the beam diameter needs to be less than or equal to 0.5 mm.

[0123]

Formula 1

[0124]

[0125] In the case of using a typical metal wire with a diameter greater than or equal to 1 mm, a beam diameter of 0.5 mm is too small. Therefore, when processing using this typical metal wire, a beam with a beam diameter of 0.5 mm cannot be used. In contrast, according to Embodiment 2, in order to be able to form a weld bead 35 with an arbitrary width, a laser beam 24 with a beam diameter of about 0.5 mm or less than or equal to 0.5 mm can be used. Thus, the additive manufacturing apparatus 100 can form a shaped object using a wire 5 made of a highly reflective material. The additive manufacturing apparatus 100 can perform shaping with a highly reflective material even without using a high-output, special laser, but using a laser used in existing additive manufacturing.

[0126] According to Embodiment 2, the additive manufacturing apparatus 100 moves the laser beam 24 at a speed higher than the speed at which the front end of the wire 5 moves, thereby expanding the irradiation region 40 of the laser beam 24 in the workpiece compared to the light spot 42. Thus, the additive manufacturing apparatus 100 can accurately form a weld bead 35 with a desired width. Additionally, the additive manufacturing apparatus 100 can use a laser beam 24 with a diameter smaller than the diameter of the wire 5, and thus can form a shaped object using a wire 5 made of a highly reflective material.

[0127] Embodiment 3.

[0128] In Embodiment 3, an example of forming a shaped object by switching between microfabrication and rough fabrication is described. The structure of the additive manufacturing apparatus 100 according to Embodiment 3 is the same as the structure of the additive manufacturing apparatus 100 according to Embodiment 1. In Embodiment 3, the same reference numerals are assigned to the same structural elements as those in the above Embodiment 1 or 2, and mainly the operations different from those in Embodiment 1 or 2 are described.

[0129] Figure 11FIG. is a view showing a case where a shaped object is formed by the additive manufacturing apparatus 100 according to Embodiment 3. The additive manufacturing apparatus 100 adjusts the movement amount of the laser beam 24 generated by the light beam driving unit 20 for each part of the object to be processed, thereby switching between microfabrication and rough fabrication for each part of the object to be processed. Microfabrication is a fabrication that emphasizes improving the shape accuracy of the shaped object rather than increasing the processing speed. Rough fabrication is a fabrication that emphasizes increasing the processing speed rather than improving the shape accuracy of the shaped object.

[0130] The arrow 53 indicates the movement of the laser beam 24 by the light beam driving unit 20. The arrow 54 indicates the traveling direction of the processing head 10. The weld bead 51 is the weld bead 35 formed by microfabrication. The weld bead 52 is the weld bead 35 formed by rough fabrication. The weld bead width in the traveling direction of the processing head 10 of the weld bead 51 is smaller than that of the weld bead 52. In Embodiment 3, the light beam driving unit 20 makes the size of the irradiation region 40 different at different positions of the reference plane among the objects to be processed.

[0131] In Figure 11 In the example shown, the light beam driving unit 20 reduces the width of the irradiation region 40 at both ends in the traveling direction of the processing head 10 among the objects to be processed, compared with other parts of the object to be processed. The light beam driving unit 20 adjusts the movement amount of the laser beam 24 in the traveling direction of the processing head 10, thereby adjusting the width of the irradiation region 40. In Figure 11 In the example shown, the light beam driving unit 20 adjusts the width of the reciprocating movement of the laser beam 24 in the traveling direction of the processing head 10, thereby adjusting the width of the irradiation region 40. The additive manufacturing apparatus 100 adjusts the width of the irradiation region 40, thereby adjusting the weld bead width of the weld bead 35 to be formed. The additive manufacturing apparatus 100 adjusts the weld bead width according to the position of the object to be processed, thereby forming the weld bead 51 at both ends in the object to be processed and forming the weld bead 52 at parts other than both ends in the object to be processed.

[0132] As described above, the additive manufacturing apparatus 100 adjusts the width of the irradiation region 40 according to the position of the reference plane in the object to be processed, thereby making the size of the irradiation region 40 different according to the position in the object to be processed. The additive manufacturing apparatus 100 makes the size of the irradiation region 40 different according to the position in the object to be processed, thereby switching between the formation of the weld bead 51 and the formation of the weld bead 52 according to the position in the object to be processed.

[0133] The additive manufacturing apparatus 100 can form a shaped object with a high-precision outer shape by microfabrication at both ends of the shaped object. In addition, the additive manufacturing apparatus 100 can shorten the overall processing time of the shaped object by rough fabrication of parts other than both ends of the shaped object.

[0134] Figure 12 This is a diagram for explaining the shapes of the bead welds 51 and 52 formed by the additive manufacturing apparatus 100 according to Embodiment 3. In Figure 12 The cross-sections of the bead weld 51 and the bead weld 52 are shown. These cross-sections are cross-sections including the traveling direction of the processing head 10 and the central axis CL of the beam nozzle 11.

[0135] If the bead width of the bead weld 51 is set as w1, the cross-sectional area of the bead weld 51 is set as M1, the bead width of the bead weld 52 is set as w2, the cross-sectional area of the bead weld 52 is set as M2, and the height of the bead welds 51 and 52 in the direction of the central axis CL is set as h, the following formulas (2) and (3) hold.

[0136] M1 = w1 / 2 × h / 2 × π · · · (2)

[0137] M2 = w2 / 2 × h / 2 × π · · · (3)

[0138] For example, when h = 0.5 mm, w1 = 1 mm, and w2 = 6 mm, from formulas (2) and (3), M1 = 0.4 mm 2 , M2 = 2.4 mm 2 . The cross-sectional area of the bead weld 52 is approximately 6 times that of the bead weld 51.

[0139] The shaping speed WFR, which is the speed of forming the bead weld 51 or the bead weld 52 by the additive manufacturing apparatus 100, is obtained by the following formula (4). In formula (4), F is set as the speed at which the laser beam 24 is moved by the beam driving unit 20. M i (i = 1, 2) represents the cross-sectional area M1 of the bead weld 51 or the cross-sectional area M2 of the bead weld 52.

[0140] WFR (cc / h) = F (mm / min) × M i (mm 2 ) × 60 (min) × 1000 ··· (4)

[0142] If the moving speed of the laser beam 24 in fine shaping and the moving speed of the laser beam 24 in rough shaping are set to be the same, the shaping speed WFR in rough shaping can be set to be approximately 6 times the shaping speed WFR in fine shaping. The additive manufacturing apparatus 100 applies fine shaping in the processing of parts requiring high shape accuracy and applies rough shaping in the processing of other parts, thereby enabling high-speed shaping of the shaped object while maintaining shape accuracy.

[0143] Regarding the portion for rough shaping, in order to achieve a high processing speed, in addition to increasing the movement amount of the laser beam 24, it is necessary to increase the supply amount of the wire material 5 and increase the heat input amount used to melt the wire material 5. The additive manufacturing apparatus 100 increases at least one of the laser output of the laser oscillator 2 and the current amount of the current flowing from the hot wire power supply 21 to the wire material 5, thereby increasing the heat input amount used to melt the wire material 5. Thereby, the additive manufacturing apparatus 100 can sufficiently melt the wire material 5, and a high processing speed can be achieved regarding the portion for rough shaping.

[0144] In addition, in the third embodiment, the control device 1 may also determine the direction in which the laser beam 24 is moved by the beam driving unit 20 based on the traveling direction of the tip of the wire material 5.

[0145] According to the third embodiment, the additive manufacturing apparatus 100 makes the size of the irradiation region 40 different at different positions of the reference planes among the workpieces. The additive manufacturing apparatus 100 can switch between micro shaping and rough shaping corresponding to the positions of the reference planes among the workpieces. The additive manufacturing apparatus 100 can arbitrarily set which one of the processing that emphasizes shape accuracy and the processing that emphasizes processing speed is to be performed for each part of the shaped object. Thereby, the additive manufacturing apparatus 100 can achieve high-speed shaping of the shaped object while maintaining the shape accuracy.

[0146] Embodiment 4.

[0147] In the fourth embodiment, an example in which the width of the reciprocating movement of the laser beam 24 in the irradiation region 40 is changed will be described. The structure of the additive manufacturing apparatus 100 according to the fourth embodiment is the same as the structure of the additive manufacturing apparatus 100 according to the first embodiment. In the fourth embodiment, the same reference numerals are given to the structural elements that are the same as those in the first to third embodiments above, and the operations different from those in the first to third embodiments will be mainly described.

[0148] Figure 13 FIG. is a diagram showing a case where the laser beam 24 is moved by the additive manufacturing apparatus 100 according to the fourth embodiment. In the fourth embodiment, the beam driving unit 20 moves the laser beam 24 at a speed higher than the speed at which the tip of the wire material 5 is moved, thereby expanding the irradiation region 55 of the laser beam 24 in the workpiece compared to the spot of the laser beam 24. The irradiation region 55 is an example of the irradiation region 40 in the case where the width of the reciprocating movement of the laser beam 24 is changed. In Figure 13 FIG., the arrow 56 shows an example of the path of the laser beam 24 moving in the irradiation region 55.

[0149] In Embodiment 4, the light beam driving unit 20 reciprocates the laser beam 24 in the irradiation region 55, and the width of the reciprocating movement of the laser beam 24 in the irradiation region 55 gradually changes. The light beam driving unit 20 is at Figure 13 In the example shown, as the laser beam 24 approaches the front end of the wire 5, the width of the reciprocating movement of the laser beam 24 decreases. As a result, the irradiation region 55 becomes a shape in which the width in the direction of reciprocating movement of the laser beam 24 continuously changes. As a result, the additive manufacturing apparatus 100 forms a bead 35 having a shape in which the width continuously changes.

[0150] Figure 14 FIG. is a diagram showing the bead 57 formed in Embodiment 4. Figure 15 FIG. is a diagram showing the bead 58 formed in the comparative example of Embodiment 4. Figure 14 The bead 57 shown is an example of the bead 35 having a shape in which the width continuously changes and is formed in Embodiment 4. Figure 15 The bead 58 shown is a combination of a plurality of wire beads and is formed by a method different from that of Embodiment 4. A wire bead is a linear bead.

[0151] In the case of forming a shape in which the width continuously changes, Figure 14 the bead 57 shown and Figure 15 the bead 58 shown have higher shape reproducibility. According to Embodiment 4, the additive manufacturing apparatus 100 gradually changes the width of the reciprocating movement of the laser beam 24 in the irradiation region 55, thereby enabling high-shape-reproducibility modeling.

[0152] In addition, in Embodiment 4, the path of the movement of the laser beam 24 by the light beam driving unit 20 is appropriately set, whereby the irradiation region 55 can be set to an arbitrary shape. In Embodiment 4, the control device 1 may also determine the direction of movement of the laser beam 24 by the light beam driving unit 20 based on the traveling direction of the front end of the wire 5.

[0153] Embodiment 5.

[0154] In Embodiment 5, an example of forming a shaped object by a bead weld is described. A bead weld is a dot-shaped weld. The structure of the additive manufacturing apparatus 100 according to Embodiment 5 is the same as the structure of the additive manufacturing apparatus 100 according to Embodiment 1. In Embodiment 5, the same reference numerals are given to the same structural elements as those in the above-described Embodiments 1 to 4, and mainly the operations different from those in Embodiments 1 to 4 are described.

[0155] Figure 16This is a diagram showing a case where a shaped object is formed by the additive manufacturing apparatus 100 according to Embodiment 5. The additive manufacturing apparatus 100 forms a shaped object by means of a bead weld bead 61. Arrow 62 indicates the movement of the laser beam 24 by the beam driving unit 20. Arrow 63 indicates the traveling direction of the processing head 10. The beam driving unit 20, which is the second driving unit, moves the laser beam 24 in the direction included in the reference plane. When forming the weld bead 61, the control device 1 moves the laser beam 24 in the direction included in the reference plane by controlling the beam driving unit 20.

[0156] Figure 17 This is the first diagram showing a case where the laser beam 24 is moved by the beam driving unit 20 of the additive manufacturing apparatus 100 according to Embodiment 5. In Figure 17 an example is shown in which the laser beam 24 is moved in an irradiation area 64 that is larger than the spot of the laser beam 24 in the base material 17 as the workpiece. In Figure 17 the situation where the laser beam 24 is moved in the irradiation area 64 is schematically shown. Figure 17 The arrow 65 shown in

[0157] In Figure 17 shows the path of the laser beam 24 moving in the irradiation area 64. The beam driving unit 20 moves the laser beam 24, thereby expanding the irradiation area 64 of the laser beam 24 in the workpiece compared to the spot of the laser beam 24.

[0158] Figure 18 This is the second diagram showing a case where the laser beam 24 is moved by the beam driving unit 20 of the additive manufacturing apparatus 100 according to Embodiment 5. In Figure 18 an example is shown in which the laser beam 24 is moved in an irradiation area 66 having a shape different from that of the irradiation area 64 shown in Figure 17 . In Figure 18 the situation where the laser beam 24 is moved in the irradiation area 66 is schematically shown. Figure 18 The arrow 67 shown in

[0159] In Figure 18Among them, a plurality of irradiation regions 66 are connected in the traveling direction of the processing head 10. Each irradiation region 66 is oval. A weld bead 61 is formed in each irradiation region 66. Thus, a weld bead 61 having an oval shape is formed on the workpiece on the reference surface. As described above, the additive manufacturing apparatus 100 appropriately sets the shapes of the irradiation regions 64 and 66, whereby a weld bead 61 having an arbitrary shape can be formed.

[0160] Next, the formation of a bead-shaped weld bead by the additive manufacturing apparatus 100 according to the fifth embodiment will be described. Here, the case of forming a bead-shaped weld bead by the additive manufacturing apparatus 100 will be described for each step. In addition, the additive manufacturing apparatus 100 forms a bead-shaped weld bead on the base material 17 as the workpiece through each step.

[0161] Figure 19 FIG. is for explaining the first step of forming a bead-shaped weld bead by the additive manufacturing apparatus 100 according to the fifth embodiment. In the first step, the additive manufacturing apparatus 100 moves the processing head 10 so that the central axis CL of the laser beam 24 coincides with the center of the processing region 34.

[0162] Figure 20 FIG. is for explaining the second step of forming a bead-shaped weld bead by the additive manufacturing apparatus 100 according to the fifth embodiment. In the second step, the additive manufacturing apparatus 100 feeds the wire 5 from the wire nozzle 12 to the processing region 34, and brings the front end portion of the wire 5 into contact with the surface 32 of the base material 17. The central axis CL of the beam nozzle 11 and the central axis CW of the wire 5 intersect at the surface 32.

[0163] Figure 21 FIG. is for explaining the third step of forming a bead-shaped weld bead by the additive manufacturing apparatus 100 according to the fifth embodiment. The additive manufacturing apparatus 100 irradiates the processing region 34 with the laser beam 24. The beam driving unit 20 moves the laser beam 24 within the irradiation regions 64 and 66.

[0164] The additive manufacturing apparatus 100 starts the injection of the inert gas 25 from the gas nozzle 13 into the processing region 34 in accordance with the irradiation of the laser beam 24. The additive manufacturing apparatus 100 may inject the inert gas 25 at a predetermined time before starting the irradiation of the laser beam 24. Thus, the additive manufacturing apparatus 100 can remove active gases such as oxygen remaining in the gas nozzle 13 from the gas nozzle 13 and then start the injection of the inert gas 25.

[0165] Figure 22FIG. is a diagram for explaining the fourth step of forming a bead weld by the additive manufacturing apparatus 100 according to Embodiment 5. The additive manufacturing apparatus 100 supplies the wire 5 from the wire nozzle 12 toward the surface 32. Thereby, the additive manufacturing apparatus 100 starts the supply of the wire 5 to the processing area 34.

[0166] By irradiating the laser beam 24, a molten pool 33 is formed in a portion within the processing area 34 of the surface 32. The melt 31 of the wire 5 is placed on the molten pool 33. The melt 31 and the molten pool 33 are integrated with each other, and the melt 31 and the molten pool 33 solidify, thereby forming a weld bead 61 joined to the base material 17. The additive manufacturing apparatus 100 starts the supply of the wire 5 to the processing area 34, and then continues the supply of the wire 5 during a predetermined supply time. The additive manufacturing apparatus 100 adjusts the rotational speed of the rotary motor 4, thereby adjusting the supply speed of the wire 5. There is a correlation between the supply speed of the wire 5 and the laser output for achieving proper welding of the melt 31. Based on this correlation, a certain limit based on the laser output is set for the supply speed of the wire 5.

[0167] By increasing the laser output of the laser oscillator 2, the time required for forming the weld bead 61 can be shortened. Further, when the supply speed of the wire 5 is too fast relative to the laser output, the wire 5 remains without melting. In addition, when the supply speed of the wire 5 is slow relative to the laser output, the wire 5 is overheated, and thereby droplets of the melt 31 fall from the wire 5. Due to the droplet fall, the melt 31 may solidify into a shape different from the desired shape of the weld bead 61. The additive manufacturing apparatus 100 appropriately adjusts the supply speed of the wire 5, thereby being able to prevent the wire 5 from remaining without melting or the droplet fall.

[0168] The size of the weld bead 61 is adjusted by changing at least one of the supply time of the wire 5, the irradiation time of continuing the irradiation of the laser beam 24, and the movement amount of the laser beam 24. The additive manufacturing apparatus 100 increases the supply time of the wire 5, lengthens the irradiation time of the laser beam 24, or increases the movement amount of the laser beam 24, thereby being able to increase the diameter of the formed weld bead 61. The additive manufacturing apparatus 100 shortens the supply time of the wire 5, shortens the irradiation time of the laser beam 24, or decreases the movement amount of the laser beam 24, thereby being able to decrease the diameter of the formed weld bead 61. In addition, the additive manufacturing apparatus 100 appropriately adjusts the movement amount of the laser beam 24, thereby being able to adjust the shape of the weld bead 61. The additive manufacturing apparatus 100 can adjust the shape of the weld bead 61 into a circular shape or an elliptical shape.

[0169] Figure 23This is a diagram for explaining the fifth step of forming a bead weld by the additive manufacturing apparatus 100 according to Embodiment 5. After placing the required amount of melt 31 for forming the weld bead 61 in the melt pool 33, the additive manufacturing apparatus 100 pulls out the wire 5 from the processing area 34.

[0170] Figure 24 This is a diagram for explaining the sixth step of forming a bead weld by the additive manufacturing apparatus 100 according to Embodiment 5. The additive manufacturing apparatus 100 stops irradiating the laser beam 24 to the processing area 34. After stopping the irradiation of the laser beam 24, the additive manufacturing apparatus 100 continues to inject the inert gas 25 for a predetermined time. The continuation time for continuing the injection of the inert gas 25 is the time required to reduce the temperature of the weld bead 61 to a predetermined temperature. The continuation time is determined based on various conditions such as the material of the wire 5 or the size of the weld bead 61. Information on the continuation time is stored in the control device 1 in advance. After stopping the irradiation of the laser beam 24, the additive manufacturing apparatus 100 stops injecting the inert gas 25 after the continuation time has elapsed. Thus, the formation of one weld bead 61 is completed.

[0171] Figure 25 This is a diagram for explaining the seventh step of forming a bead weld by the additive manufacturing apparatus 100 according to Embodiment 5. The additive manufacturing apparatus 100 moves the processing head 10 to the next processing point. Figure 25 The arrow 63 shown indicates the traveling direction of the processing head 10. The additive manufacturing apparatus 100 repeats the first step to the seventh step, thereby forming a shaped object.

[0172] In addition, in the above-described second step and third step, the wire 5 is sent from the wire nozzle 12 to the processing area 34, and then the laser beam 24 is irradiated toward the processing area 34. The additive manufacturing apparatus 100 may also irradiate the laser beam 24 toward the processing area 34 and then send the wire 5 from the wire nozzle 12 to the processing area 34.

[0173] Figure 26 This is a diagram for explaining the eighth step of forming a bead weld by the additive manufacturing apparatus 100 according to Embodiment 5. Figure 27 This is a diagram for explaining the ninth step of forming a bead weld by the additive manufacturing apparatus 100 according to Embodiment 5. Figure 28 This is a diagram for explaining the tenth step of forming a bead weld by the additive manufacturing apparatus 100 according to Embodiment 5. The additive manufacturing apparatus 100 may perform the eighth step to the tenth step in place of the above-described second step and third step.

[0174] The additive manufacturing apparatus 100 is as Figure 26As shown, in the 8th step, the laser beam 24 is irradiated toward the processing area 34. The additive manufacturing apparatus 100 is as Figure 27 shown, and in the 9th step, the laser beam 24 is moved. The beam driving unit 20 moves the laser beam 24 within the irradiation areas 64, 66. Thereby, the additive manufacturing apparatus 100 starts moving the laser beam 24 from the Figure 26 state shown.

[0175] Then, as shown in Figure 28 shown, in the 10th step, the additive manufacturing apparatus 100 feeds the wire 5 from the wire nozzle 12 to the processing area 34, and makes the front end portion of the wire 5 contact the surface 32 of the base material 17. If the additive manufacturing apparatus 100 finishes the 10th step, it performs the operations related to the sequence after the above-mentioned 4th step.

[0176] Through the 8th step to the 10th step, the additive manufacturing apparatus 100 irradiates the laser beam 24, moves the laser beam 24 within the irradiation areas 64, 66, and then feeds the wire 5 to the processing area 34. In this case, the additive manufacturing apparatus 100 starts feeding the wire 5 after forming the molten pool 33 on the surface 32.

[0177] According to Embodiment 5, when the additive manufacturing apparatus 100 forms a bead weld, it moves the laser beam 24 within the irradiation areas 64, 66. The additive manufacturing apparatus 100 can form a shaped object with a bead weld of any shape. By forming a shaped object with a bead weld of any shape, the additive manufacturing apparatus 100 can perform high-precision shaping.

[0178] In addition, in Embodiment 5, by appropriately setting the path for moving the laser beam 24 by the beam driving unit 20, the irradiation areas 64, 66 can be set to any shape. In Embodiment 5, the control device 1 may also determine the direction of moving the laser beam 24 by the beam driving unit 20 based on the traveling direction of the front end portion of the wire 5. The control device 1 can determine the orientation or the shape of the irradiation areas 64, 66 based on the traveling direction. The beam driving unit 20 can make the sizes of the irradiation areas 64, 66 different at different positions of the reference plane among the workpieces.

[0179] The additive manufacturing apparatus 100 according to Embodiment 5 is not limited to forming the entire shaped object by bead welds. The additive manufacturing apparatus 100 according to Embodiment 5 only needs to form at least a part of the bead welds constituting the shaped object when manufacturing a shaped object by attaching the material melted by the irradiation of the laser beam 24 to the workpiece.

[0180] Next, the hardware structure of the control device 1 involved in Implementations 1 to 5 will be described. The control device 1 is implemented by a processing circuit. The processing circuit can be a circuit in which a processor executes software, or a dedicated circuit.

[0181] In the case where the processing circuit is implemented by software, the processing circuit is, for example, Figure 29 the control circuit 80 shown. Figure 29 is a diagram showing a structural example of the control circuit 80 involved in Implementations 1 to 5. The control circuit 80 has an input unit 81, a processor 82, a memory 83, and an output unit 84.

[0182] The input unit 81 is an interface circuit that receives data input from the outside of the control circuit 80 and assigns it to the processor 82. The output unit 84 is an interface circuit that sends data from the processor 82 or the memory 83 to the outside of the control circuit 80. When the processing circuit is Figure 29 the control circuit 80 shown, the processor 82 reads and executes the program stored in the memory 83, thereby implementing the functions of the control device 1. The memory 83 is also used as a temporary memory in each process implemented by the processor 82.

[0183] The processor 82 is a CPU (also known as Central Processing Unit, central processing device, processing device, arithmetic device, microprocessor, microcomputer, processor, or DSP (Digital Signal Processor)). The memory 83 is, for example, a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (registered trademark) (Electrically Erasable Programmable Read Only Memory), a magnetic disk, a floppy disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disc).

[0184] Figure 29 This is an example of the hardware in the case where the control device 1 is implemented by a general-purpose processor 82 and a memory 83, but the control device 1 can also be implemented by a dedicated hardware circuit. Figure 30 is a diagram showing a structural example of the dedicated hardware circuit 85 involved in Implementations 1 to 5.

[0185] The dedicated hardware circuit 85 has an input section 81, an output section 84, and a processing circuit 86. The processing circuit 86 is a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a circuit combining them. In addition, the control device 1 can also be implemented by combining the control circuit 80 and the hardware circuit 85.

[0186] The structures shown in the above embodiments illustrate an example of the content of the present invention. The structures of the embodiments can be combined with other known technologies. The structures of the embodiments can also be appropriately combined with each other. A part of the structure of each embodiment can be omitted or changed without departing from the gist of the present invention.

[0187] Description of reference numerals

[0188] 1 Control device, 2 Laser oscillator, 3 Optical cable, 4 Rotary motor, 5 Wire, 6 Wire spool, 7 Gas supply device, 8 Pipe, 10 Processing head, 11 Beam nozzle, 12 Wire nozzle, 13 Gas nozzle, 14 Processing head drive unit, 15 Workbench, 16 Rotation mechanism, 17 Substrate, 18 Deposit, 19 Material supply unit, 20 Beam drive unit, 21 Hot wire power supply, 22 Current cable, 23 Insulator, 24 Laser beam, 25 Inert gas, 31 Melt, 32 Surface, 33 Melt pool, 34 Processing area, 35, 51, 52, 57, 58, 61 Weld bead, 36, 37, 39, 41, 53, 54, 56, 62, 63, 65, 67 Arrow, 38, 42 Light spot, 40, 43, 44, 55, 64, 66 Irradiation area, 80 Control circuit, 81 Input section, 82 Processor, 83 Memory, 84 Output section, 85 Hardware circuit, 86 Processing circuit, 100 Additive manufacturing device, CL, CW Central axis.

Claims

1. An additive manufacturing device that attaches a material melted by the irradiation of a light beam to a workpiece to manufacture a shaped object. The additive manufacturing device is characterized by comprising: A processing head; A light beam nozzle integrated with the processing head through which the light beam emitted from the processing head passes; A material supply unit integrated with the processing head that supplies the material to the workpiece; A first drive unit that moves the processing head, the beam nozzle, and the material supply unit relative to the workpiece, thereby moving the front end portion on the workpiece side among the materials relative to the workpiece; A second drive unit that moves the beam relative to the beam nozzle in a direction included in a reference plane that is a plane perpendicular to the central axis of the beam nozzle; And A control device that determines the direction in which the beam is moved by the second drive unit based on the direction included in the reference plane and the traveling direction in which the front end portion travels relative to the workpiece, and controls the first drive unit and the second drive unit so that the beam can be moved in a manner different from the movement of the front end portion relative to the workpiece, The beam has a light spot as a cross-section on the reference plane, The beam can be moved in such a manner that the center of the light spot is displaced forward relative to the front end portion corresponding to the traveling direction, and the amount of displacement of the center of the light spot increases as the traveling direction approaches perpendicular to the central axis of the material, and the amount of displacement is maximum when the traveling direction is perpendicular to the central axis of the material.

2. An additive manufacturing device that attaches a material melted by the irradiation of a light beam to a workpiece to manufacture a shaped object. The additive manufacturing device is characterized by comprising: A processing head; A light beam nozzle integrated with the processing head through which the light beam emitted from the processing head passes; A material supply unit integrated with the processing head that supplies the material to the workpiece; A first drive unit that moves the processing head, the beam nozzle, and the material supply unit relative to the workpiece, thereby moving the front end portion on the workpiece side among the materials relative to the workpiece; A second drive unit that moves the beam relative to the beam nozzle in a direction included in a reference plane that is a plane perpendicular to the central axis of the beam nozzle; And A control device that determines the direction in which the beam is moved by the second drive unit based on the direction included in the reference plane and the traveling direction in which the front end portion travels relative to the workpiece, and controls the first drive unit and the second drive unit so that the beam can be moved in a manner different from the movement of the front end portion relative to the workpiece, The second drive unit moves the beam at a higher speed than the speed at which the front end portion is moved, thereby expanding the irradiation area of the beam in the workpiece compared to the light spot of the beam, and changing the orientation of the irradiation area so that the width of the weld bead formed by the melted material becomes constant.

3. The additive manufacturing device according to claim 2, characterized in that The control device determines the orientation or the shape of the irradiation area based on the direction included in the reference plane and the traveling direction in which the front end portion travels relative to the workpiece.

4. The additive manufacturing device according to claim 2 or 3, characterized in that The second drive unit reciprocates the beam in the irradiation area, and the width of the reciprocating movement of the beam in the irradiation area gradually changes.

5. The additive manufacturing device according to claim 2 or 3, characterized in that The diameter of the beam is smaller than the diameter of the wire material as the material.

6. An additive manufacturing method, characterized in that Including the following steps: When attaching the material melted by the irradiation of the beam to the workpiece, the beam nozzle and the material through which the beam passes are integrally moved, thereby moving the front end portion on the workpiece side among the materials relative to the workpiece; Determine the direction in which the light beam is to be moved relative to the beam nozzle based on the direction included in the reference plane, which is a plane perpendicular to the central axis of the beam nozzle through which the light beam passes, and the direction of travel in which the front end portion travels relative to the workpiece; and Move the light beam relative to the beam nozzle, whereby the light beam is moved in a manner different from the movement of the front end portion relative to the workpiece, The light beam has a light spot as a cross-section on the reference plane, In the step of moving the light beam, the light beam can be moved in such a manner that the center of the light spot is displaced forward relative to the front end portion corresponding to the direction of travel. The closer the direction of travel is to being perpendicular to the central axis of the material, the greater the amount of displacement of the center of the light spot. When the direction of travel is perpendicular to the central axis of the material, the amount of displacement is the largest.

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