Additive manufacturing method and additive manufacturing system

Abstract

This technology provides an efficient way to preheat the base material. [Solution] The additive manufacturing method includes the steps of: laminating a first welding bead 70a onto the first base material 80a while the first base material 80a and the second base material 80b are stacked on top of each other; and laminating a second welding bead 70b onto the second base material 80b after the first base material 80a has been removed.

Description

Technical Field

[0006] , , ,

[0005] , ,

[0001] The present disclosure relates to a layered manufacturing method and a layered manufacturing system.

Background Art

[0002] Japanese Patent No. 7010767 (Patent Document 1) discloses a method of manufacturing a welded structure by laminating weld beads on the surface of a base material. In Japanese Patent No. 7010767 (Patent Document 1), in order to prevent the hardness of the formed portion on the surface of the base material from decreasing due to insufficient heat input to the base material, a heat input bead for heat input is formed on the surface of the base material. Japanese Patent No. 7010767 (Patent Document 1) improves the fatigue strength of the formed portion formed on the base material by preheating the base material with the heat input bead.

Prior Art Documents

Patent Documents

[0003] <00000​​​​​​​​​​​​​​​​​​​​​​​This disclosure relates to an additive manufacturing method for creating an object by supplying a welding current to a consumable electrode wire and layering welding beads onto a base material. The base material includes at least a first base material used for layering first welding beads to create a first object, and a second base material used for layering second welding beads to create a second object. The additive manufacturing method includes the steps of layering first welding beads onto the first base material while the first and second base materials are stacked on top of each other, and layering second welding beads onto the second base material after the first base material has been removed. [Effects of the Invention]

[0007] In the additive manufacturing method of this disclosure, a first welding bead is deposited onto the first base material while the first base material and the second base material are stacked, and after the first base material is removed, a second welding bead is deposited onto the second base material. This allows the heat generated during the deposition of the first welding bead onto the first base material to be used as preheating for the second base material, thus enabling efficient preheating of the base materials. [Brief explanation of the drawing]

[0008] [Figure 1] This figure schematically shows the additive manufacturing system according to Embodiment 1. [Figure 2] This figure shows an example of an additive manufacturing method according to Embodiment 1. [Figure 3] This is a flowchart showing the control contents according to Embodiment 1. [Figure 4] This figure shows an example of an additive manufacturing method related to a modified example. [Figure 5] This figure schematically shows the additive manufacturing system according to Embodiment 2. [Figure 6] This is a flowchart showing the control contents according to Embodiment 1. [Modes for carrying out the invention]

[0009] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0010] [Embodiment 1] Figure 1 is a schematic diagram showing an additive manufacturing system 1 according to Embodiment 1. The additive manufacturing system 1 comprises a robot arm 40, a welding torch 20, a welding power supply 10, a wire feeder 50, a base material supplyer 90, and a control device 30.

[0011] The robot arm 40 is a multi-jointed arm, for example, a 6-axis multi-jointed arm. The robot arm 40 functions as a drive device that moves the welding torch 20 at a preset or calculated welding speed. As the robot arm 40 moves the welding torch 20, a welding bead 70 made by melting the consumable electrode wire 51 is built up. The robot arm 40 is controlled by the control device 30 so that an object is formed by the buildup of the welding bead 70.

[0012] In the welding torch 20, a welding current is supplied to the consumable electrode wire 51 at a power supply tip (not shown) located inside the nozzle 21. The consumable electrode wire 51 melts due to the arc generated between it and the base material 80 or the already layered welding bead 70, and due to resistance heating caused by the current. The melting of the consumable electrode wire 51 forms the welding bead 70. The welding torch 20 performs the layering of the welding bead 70 using the consumable electrode wire 51. The welding torch 20 is supplied with shielding gas by a shielding gas supply unit (not shown), and the shielding gas exits the nozzle 21 and reaches the arc 22 and the molten area. The shielding gas may be, for example, argon, CO2, or a mixture of these.

[0013] The torch cable 11 connected to the welding torch 20 contains a cable for the current supplied from the welding power source 10, a consumable electrode wire 51 supplied from the wire feeding device 50, and a pipe for the shielding gas supplied from a shielding gas supply unit (not shown).

[0014] The welding power supply 10 supplies alternating current as welding current to the consumable electrode wire 51. The magnitude of the welding current output from the welding power supply 10 is set by the control device 30. The wire feeder 50 includes a roller and a motor (not shown). The wire feeder 50 feeds the consumable electrode wire 51 to the welding torch 20 by driving the motor and rotating the roller. The operation of the wire feeder 50 is controlled by the welding power supply 10 based on commands from the control device 30. The operation of the wire feeder 50 may also be directly controlled by the welding power supply 10.

[0015] The base material supply device 90 is a device for removing the base material 80 after the lamination is complete and the molded object has been formed, and for setting the next base material 80 to the position where the welding bead 70 will be laminated. For example, the base material supply device 90 has multiple base materials 80 set inside, and after the base material 80 that has formed the molded object is slid to move, a new base material is raised and set to the position where the welding bead 70 will be laminated. By performing this series of steps, the base material supply device 90 performs the operation of continuously supplying the base material 80.

[0016] The base material supply device 90 includes a detection device 91. The detection device 91 is a device for detecting that the base material 80 has been removed from the set position for stacking the welding beads 70 and that a new base material 80 has been placed in the set position. The detection device 91 may have any structure, but for example, it may use a light sensor that detects the presence or absence of an object using light, an image sensor that detects the presence or absence of an object using a camera, or a contact sensor that detects the presence or absence of an object by contact with it.

[0017] The control device 30 comprises an arithmetic unit 31, a memory 32, a storage device 33, and an input / output interface 34. These components are connected via a bus.

[0018] The arithmetic unit 31 is an arithmetic entity (computer) that executes predetermined processing. The arithmetic unit 31 is composed of a processor such as a CPU (Central Processing Unit), MPU (Micro-Processing Unit), TPU (Tensor Processing Unit), or GPU (Graphics Processing Unit), for example. The arithmetic unit 31 can also be read as a processing circuit (Processing Circuitry) that executes predetermined processing.

[0019] The memory 32 includes a storage area (for example, a working area) that stores program codes or a work memory when the arithmetic unit 31 executes various programs.

[0020] The storage device 33 functions as a storage unit that stores various programs or various data executed by the arithmetic unit 31. For example, the storage device 33 stores a control program 330 executed by the arithmetic unit 31.

[0021] The input / output interface 34 receives inputs of various data. The input / output interface 34 outputs data required by various processes according to instructions from the arithmetic unit 31. Information detected by the detection device 91 is input to the input / output interface 34.

[0022] The layered manufacturing system 1 manufactures a shaped object by supplying a welding current to the consumable electrode wire 51 and laminating weld beads 70 over multiple layers. In the layered manufacturing system 1, the control device 30 controls the welding current output from the welding power source 10. In the layered manufacturing system 1, the control device 30 controls the welding speed by driving the robot arm 40. The control device 30 controls, for example, the operation of the robot arm 40. In the layered manufacturing system 1, the control device 30 continuously supplies the base material 80 by driving the base material supply device 90.

[0023] A method for additive manufacturing according to Embodiment 1 will be described. Figure 2 shows an example of the additive manufacturing method according to Embodiment 1. In additive manufacturing, if the heat input to the base material 80 is insufficient, the heat input to the welding bead 70 that is layered on the base material 80 will be insufficient, which may reduce the hardness of the manufactured object. For this reason, it is necessary to preheat the base material 80 to eliminate the insufficient heat input to the welding bead 70 that is layered on the base material 80. The additive manufacturing method according to Embodiment 1 is a method that can efficiently preheat the base material 80.

[0024] Figure 2(a) shows the process of creating the first object, Figure 2(b) shows the process of creating the second object, and Figure 2(c) shows the process of creating the third object. Multiple base materials 80 are installed in a stacked state. As shown in Figure 2(a), the base materials 80 are stacked in the order of first base material 80a, second base material 80b, third base material 80c, and fourth base material 80d in the stacking direction, and multiple more base materials are stacked on the lower side of the fourth base material 80d in the stacking direction.

[0025] In the additive manufacturing method according to Embodiment 1, as shown in Figure 2(a), the first base material 80a and the second base material 80b are stacked, and the first welding bead 70a is laminated onto the first base material 80a. In the following, the welding bead 70 will be referred to as follows: the welding bead 70 on the first base material 80a is referred to as the first welding bead 70a, the welding bead 70 on the second base material 80b is referred to as the second welding bead 70b, the welding bead 70 on the third base material 80c is referred to as the third welding bead 70c, and the welding bead 70 on the fourth base material 80d is referred to as the fourth welding bead 70d. Also, Figure 2 shows only the first layer of the lamination, and the description of the second and subsequent layers is omitted.

[0026] In the additive manufacturing method according to Embodiment 1, after the layering of the first welding bead 70a is completed, the first base material 80a is removed. As a result, the second base material 80b is placed on top. Next, in the additive manufacturing method according to Embodiment 1, as shown in Figure 2(b), the second welding bead 70b is layered onto the second base material 80b while the second base material 80b and the third base material 80c are stacked on top of each other.

[0027] In the additive manufacturing method according to Embodiment 1, after the layering of the second welding bead 70b is completed, the second base material 80b is removed. This leaves the third base material 80c in the uppermost layer. Next, in the additive manufacturing method according to Embodiment 1, as shown in Figure 2(c), the third welding bead 70c is layered onto the third base material 80c while the third base material 80c and the fourth base material 80d are stacked on top of each other. Thereafter, each step is repeated until all layering is completed.

[0028] In the additive manufacturing method according to Embodiment 1, as shown in Figure 2, the thicknesses of the first base material 80a, the second base material 80b, the third base material 80c, and the fourth base material 80d are approximately the same. "Approximately the same" means that things that are substantially the same, such as precision errors that may inevitably exist during manufacturing, are treated as the same. In the additive manufacturing method according to Embodiment 1, since the thickness of each base material 80 is approximately the same, the heat transferred from the top layer to the layer below when stacked can be made the same between Figures 2(a), (b), and (c).

[0029] In the additive manufacturing method according to Embodiment 1, the layering of the welding beads 70 may be performed with multiple sheets of different thicknesses stacked on top of each other. In such a case, it is desirable that the overall thickness of the base material 80 in the stacked state be constant. In this way, for example, the overall thickness of the base material 80 is constant in the step of layering the first welding bead 70a and the second welding bead 70b, so that the heat transmitted to the entire base material 80 in the stacked state can be made almost constant.

[0030] Next, the control content performed in Embodiment 1 will be described. Figure 3 is a flowchart showing the control content related to Embodiment 1. The processing in the flowchart of Figure 3 is repeatedly called and executed as a subroutine from the main routine in the control of the control device 30. First, in step S (hereinafter simply referred to as "S") 11, the control device 30 drives the base material supply device 90 and sets multiple base materials 80 stacked on top of each other. The number of base materials 80 set can be changed depending on the number of objects to be fabricated, and it is sufficient to have two or more.

[0031] Next, the control device 30 performs the process of laminating the welding bead 70 onto the uppermost base material 80 (S12). Next, the control device 30 determines whether or not the lamination using the welding bead 70, which is performed according to the lamination program, has been completed (S13). If the control device 30 determines in S13 that the lamination has not been completed (NO in S13), it repeats the process in S12. If the control device 30 determines in S13 that the lamination has been completed (YES in S13), it proceeds to the process in S14.

[0032] In S14, the control device 30 determines whether or not the base material 80, after lamination has been completed, has been removed. Specifically, in S14, the control device 30 determines whether or not the base material 80, after lamination has been completed, has been removed based on information from the detection device 91. If the control device 30 determines in S14 that the base material 80, after lamination has been completed, has not been removed (NO in S14), it repeats the process in S14 until the base material 80 is removed.

[0033] If the control device 30 determines in S14 that the base material 80, which has been laminated, has been removed (YES in S14), it proceeds to the process in S15. In S15, the control device 30 determines whether all lamination according to the predetermined program has been completed. If the control device determines in S15 that all lamination has been completed (YES in S15), it terminates the process.

[0034] If the control device 30 determines in S15 that all lamination has not been completed (NO in S15), it sets the next base material 80 with multiple layers stacked on top of each other (S16) and proceeds to the process in S12. In S16, the control device 30 drives the base material supply device 90 to set the next base material 80 as the bottom layer with multiple layers stacked on top of each other, and moves the multiple base material 80 to a position where the welding bead 70 will be laminated onto the top layer base material 80.

[0035] As described above, in the additive manufacturing method of Embodiment 1, since the welding bead 70 is laid on the uppermost base material 80 while multiple base materials 80 are stacked, the heat input to the base material 80 on which the welding bead 70 is currently being laid is transferred to the base material 80 on which the welding bead 70 will be laid next. Specifically, according to the additive manufacturing method of Embodiment 1, the first welding bead 70a is laid on the first base material 80a while the first base material 80a and the second base material 80b are stacked, and after the first base material 80a is removed, the second welding bead 70b is laid on the second base material 80b. As a result, the heat generated during the laying of the first welding bead 70a on the first base material 80a can be used as preheating for the second base material 80b, thus enabling efficient preheating of the second base material 80b (base material 80).

[0036] [Modified example of Embodiment 1] A modified version of the additive manufacturing method of Embodiment 1 will be described. Figure 4 shows an example of the additive manufacturing method according to the modified version. The additive manufacturing method according to the modified version differs from the additive manufacturing method of Embodiment 1 in the method of setting the base material 80.

[0037] Figure 4(a) shows the process of creating the first object, Figure 4(b) shows the process of creating the second object, and Figure 4(c) shows the process of creating the third object. The base material 80 is installed in a stacked state. As shown in Figure 4(a), the base material 80 is stacked in the order of first base material 80a and second base material 80b in the stacking direction, and no base material 80 is installed on the lower layer side of the second base material 80b in the stacking direction.

[0038] In the modified additive manufacturing method, as shown in Figure 4(a), a step is performed in which a first welding bead 70a is laminated onto the first base material 80a while the first base material 80a and the second base material 80b are stacked on top of each other. In the modified additive manufacturing method, a step is performed in which the first base material 80a is removed after the lamination of the first welding bead 70a is completed. Furthermore, in the modified additive manufacturing method, a step is performed in which the second base material 80b is positioned (raised) at the starting position of the lamination, and the third base material 80c is stacked on the lower side of the second base material 80b. Next, in the modified additive manufacturing method, as shown in Figure 4(b), a step is performed in which a second welding bead 70b is laminated onto the second base material 80b while the second base material 80b and the third base material 80c are stacked on top of each other.

[0039] In the modified additive manufacturing method, after the layering of the second welding bead 70b is completed, the second base material 80b is removed. Furthermore, in the modified additive manufacturing method, the third base material 80c is positioned (raised) at the starting position of the layering, and the fourth base material 80d is placed on top of the third base material 80c. Next, in the modified additive manufacturing method, as shown in Figure 4(c), the third welding bead 70c is layered onto the third base material 80c while the third base material 80c and the fourth base material 80d are stacked on top of each other. Thereafter, each step is repeated until all layering is completed.

[0040] In the modified additive manufacturing method, by repeatedly swapping the two base materials 80, the number of layers of base material 80 can be reduced to two compared to the additive manufacturing method according to Embodiment 1. Furthermore, in the modified additive manufacturing method, similar to the additive manufacturing method according to Embodiment 1, the heat generated during the deposition of the first welding bead 70a onto the first base material 80a can be used as preheating for the second base material 80b, thus enabling efficient preheating of the second base material 80b (base material 80).

[0041] [Embodiment 2] The additive manufacturing method according to Embodiment 2 will now be described. First, the additive manufacturing system 1A used in the additive manufacturing method according to Embodiment 2 will be described. Figure 5 is a schematic diagram showing the additive manufacturing system 1A according to Embodiment 2. The additive manufacturing system 1A according to Embodiment 2 differs from the additive manufacturing system 1 according to Embodiment 1 in that it is equipped with a temperature sensor 61.

[0042] The temperature sensor 61 detects the surface temperature T of the base material 80. The temperature sensor 61 is preferably a non-contact type sensor, such as a thermal camera. The temperature information of the surface temperature T of the base material 80 detected by the temperature sensor 61 is transmitted to the control device 30. The temperature sensor 61 may be a pyrometer that captures a point rather than a thermal camera that captures a surface.

[0043] The control device 30 controls the operation of the base material supply device 90 based on the temperature information of the surface temperature T of the base material 80 received from the temperature sensor 61. For example, the control device 30 adjusts the number of base material 80 to be supplied based on the temperature information of the surface temperature T of the base material 80.

[0044] Next, the control content performed in Embodiment 2 will be described. Figure 6 is a flowchart showing the control content according to Embodiment 2. The processing in the flowchart of Figure 6 is repeatedly called and executed as a subroutine from the main routine in the control of the control device 30. First, in S21, the control device 30 sets multiple base materials 80 based on the detected value of the temperature sensor 61. The number of base materials 80 to be set only needs to be predetermined based on the detected value of the temperature sensor 61, and it is sufficient that two or more are set in a stacked state.

[0045] Next, the control device 30 performs the process of laminating the welding bead 70 onto the uppermost base material 80 (S22). Next, the control device 30 determines whether or not the lamination using the welding bead 70, which is performed according to the lamination program, has been completed (S23). If the control device 30 determines in S23 that the lamination has not been completed (NO in S23), it repeats the process in S22. If the control device 30 determines in S23 that the lamination has been completed (YES in S23), it proceeds to the process in S24.

[0046] In S24, the control device 30 sets the base material 80 to be supplied based on the value detected by the temperature sensor 61. For example, in the process of S24, the number of base material 80 sets should be increased as the value detected by the temperature sensor 61 increases. The relationship between the value detected by the temperature sensor 61 and the number of base material 80 sets should be stored in the storage device 33.

[0047] Next, in S25, the control device 30 determines whether or not the base material 80, which has finished lamination, has been removed. Specifically, in S25, the control device 30 determines whether or not the base material 80, which has finished lamination, has been removed based on the information from the detection device 91. If the control device 30 determines in S25 that the base material 80, which has finished lamination, has not been removed (NO in S25), it repeats the process in S25 until the base material 80 is removed.

[0048] If the control device 30 determines in S25 that the base material 80, which has been laminated, has been removed (YES in S25), it proceeds to the process in S26. In S26, the control device 30 determines whether all lamination according to the predetermined program has been completed. If the control device determines in S26 that all lamination has been completed (YES in S26), it terminates the process.

[0049] If the control device 30 determines in S26 that all lamination has not been completed (NO in S26), it sets the base material 80 set in S24 (S27) and proceeds to the process in S22. In S27, the control device 30 drives the base material supply device 90 and sets the number of base material 80 set in S24 to the bottom layer with multiple base material 80 stacked on top of each other, and moves the multiple base material 80 to the position where the welding bead 70 will be laminated onto the top layer of base material 80.

[0050] As described above, in the additive manufacturing method of Embodiment 2, since the welding bead 70 is laid on the uppermost base material 80 while multiple base materials 80 are stacked, the heat input to the base material 80 on which the welding bead 70 is currently being laid is transferred to the base material 80 on which the welding bead 70 will be laid next. Furthermore, the number of base materials 80 supplied is changed based on the value detected by the temperature sensor 61. This allows for efficient preheating of the base materials 80 by adjusting the number of base materials 80 to be preheated based on the temperature of the base material 80 on which the layering is currently being performed.

[0051] [Other variations] In the above embodiment, a heat source may be used to supplementarily heat the base material 80 which is stacked in the stacking direction. If the temperature of the base material 80 rises too high due to the stacking by the welding bead 70, additional base material 80 may be added for cooling. Instead of adding additional base material 80 for cooling, a separate device for cooling the base material 80 may be installed.

[0052] [summary] (1) This disclosure relates to an additive manufacturing method for manufacturing an object by supplying a welding current to a consumable electrode wire 51 and stacking a welding bead 70 on a base material 80. The base material 80 includes at least a first base material 80a used for stacking a first welding bead 70a to manufacture a first object, and a second base material 80b used for stacking a second welding bead 70b to manufacture a second object. The additive manufacturing method includes the steps of stacking a first welding bead 70a on the first base material 80a while the first base material 80a and the second base material 80b are stacked on top of each other, and stacking a second welding bead 70b on the second base material 80b after the first base material 80a has been removed.

[0053] According to the additive manufacturing method of this disclosure, the heat generated during the deposition of the first welding bead 70a onto the first base material 80a can be used as preheating for the second base material 80b, thereby enabling efficient preheating of the second base material 80b (base material 80).

[0054] (2) In the additive manufacturing method of (1), the base material 80 includes a first base material 80a and a second base material 80b, as well as a third base material 80c used for layering a third welding bead 70c for forming a third molded object. The step of layering the first welding bead 70a includes the step of layering the first welding bead 70a on the first base material 80a with the first base material 80a, the second base material 80b, and the third base material 80c stacked in this order.

[0055] According to the additive manufacturing method of this disclosure, preheating of multiple base materials 80 can be efficiently performed when multiple base materials 80 are stacked on top of each other.

[0056] (3) In the additive manufacturing method of (1), the base material 80 includes a first base material 80a and a second base material 80b, as well as a third base material 80c used for layering a third welding bead 70c for forming a third molded object. The additive manufacturing method further includes the step of layering the third base material 80c on the second base material 80b after the first base material 80a has been removed. The step of layering the second welding bead 70b includes the step of layering the welding bead 70 on the second base material 80b while the second base material 80b and the third base material 80c are layered on top of each other.

[0057] According to the additive manufacturing method of this disclosure, preheating of the two base materials 80 can be efficiently performed using two base materials 80 while the two base materials 80 are stacked on top of each other.

[0058] (4) In the additive manufacturing method described in any of (1) to (3), the thickness of the first base material 80a and the second base material 80b are approximately the same.

[0059] According to the additive manufacturing method of this disclosure, since the thickness of each base material 80 is approximately the same, the heat transferred from the top layer to the layer below in the stacked state can be made the same in each process.

[0060] (5) In the additive manufacturing method described in any of (1) to (3), the base material 80 is placed in such a way that the total thickness becomes a predetermined value when multiple pieces of different thicknesses are stacked together in each of the steps of stacking the first welding bead 70a and stacking the second welding bead 70b.

[0061] According to the additive manufacturing method of this disclosure, when multiple base materials 80 are stacked, the heat transmitted to the entire base material 80 can be kept almost constant.

[0062] (6) The additive manufacturing method described in any of (1) to (5) further includes the step of measuring the temperature of the first base material 80a after the completion of the layering of the first welding bead 70a, and the step of setting the base material 80 to be supplied based on the temperature of the first base material 80a.

[0063] According to the additive manufacturing method of this disclosure, the base material 80 to which preheating is applied is adjusted based on the temperature of the base material 80 on which the additive manufacturing is currently being performed, and preheating of the base material 80 can be performed efficiently.

[0064] (7) This disclosure relates to an additive manufacturing system 1 that manufactures an object by supplying a welding current to a consumable electrode wire 51 and stacking welding beads 70 on a base material 80. The additive manufacturing system 1 includes a welding torch 20 that performs stacking of welding beads 70 using a consumable electrode wire 51, a drive device (robot arm 40) that moves the welding torch 20, a welding power supply 10 that supplies a welding current to the consumable electrode wire 51, and a control device 30 that controls the welding power supply 10 and the drive device (robot arm 40). The control device 30 starts stacking the welding beads 70 with a first base material 80a used for stacking welding beads 70 corresponding to a first object and a second base material 80b used for stacking welding beads 70 corresponding to a second object stacked on top of each other.

[0065] According to the additive manufacturing system 1 of this disclosure, the heat generated during the deposition of the first welding bead 70a onto the first base material 80a can be used as preheating for the second base material 80b, thereby enabling efficient preheating of the second base material 80b (base material 80).

[0066] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0067] 1.1A Additive manufacturing system, 10 Welding power supply, 20 Welding torch, 21 Nozzle, 22 Arc, 30 Control device, 31 Calculation unit, 32 Memory, 33 Storage device, 34 Input / Output interface, 40 Robot arm, 50 Wire feeder, 51 Consumable electrode wire, 61 Temperature sensor, 70 Weld bead, 70a First weld bead, 70b Second weld bead, 70c Third weld bead, 70d Fourth weld bead, 80 Base material, 80a First base material, 80b Second base material, 80c Third base material, 80d Fourth base material, 90 Base material supply device, 91 Detection device, 330 Control program.

Claims

1. A method of additive manufacturing in which a welding current is supplied to a consumable electrode wire and a welding bead is built up on a base material to create a shape, The base material includes at least a first base material used for laminating a first welding bead to form a first molded object, and a second base material used for laminating a second welding bead to form a second molded object. The aforementioned additive manufacturing method is The first base material and the second base material are stacked on top of each other, and the first welding bead is laminated onto the first base material. A method for additive manufacturing, comprising the step of stacking the second welding bead onto the second base material after the first base material has been removed.

2. The base material includes, in addition to the first base material and the second base material, a third base material used for laminating a third welding bead for forming a third molded object. The additive manufacturing method according to claim 1, wherein the step of laminating the first welding bead includes the step of laminating the first welding bead onto the first base material while the first base material, the second base material, and the third base material are stacked in that order.

3. The base material includes, in addition to the first base material and the second base material, a third base material used for laminating a third welding bead for forming a third molded object. The additive manufacturing method further includes the step of stacking the third base material on the second base material after the first base material has been removed, The additive manufacturing method according to claim 1, wherein the step of laminating the second welding bead includes the step of laminating the welding bead onto the second base material while the second base material and the third base material are stacked on top of each other.

4. The additive manufacturing method according to any one of claims 1 to 3, wherein the thickness of the first base material and the second base material are substantially the same.

5. The additive manufacturing method according to any one of claims 1 to 3, wherein the base material is installed in each of the steps of laminating the first welding bead and laminating the second welding bead such that the total thickness becomes a predetermined value when multiple pieces of different thicknesses are stacked on top of each other.

6. The steps include measuring the temperature of the first base material after the lamination of the first welding bead is completed, The additive manufacturing method according to any one of claims 1 to 3, further comprising the step of setting the base material to be supplied based on the temperature of the first base material.

7. An additive manufacturing system that creates an object by supplying welding current to a consumable electrode wire and layering welding beads onto a base material, A welding torch that performs the stacking of the welding beads using the consumable electrode wire, A drive device for moving the welding torch, A welding power supply that supplies the welding current to the consumable electrode wire, The system comprises a control device for controlling the welding power supply and the drive device, The control device is an additive manufacturing system that starts the layering of welding beads with a first base material used for layering welding beads corresponding to a first molded object and a second base material used for layering welding beads corresponding to a second molded object stacked on top of each other.

Images