Method for manufacturing a laminated object

Abstract

A method for manufacturing a laminated object comprises forming a weld bead by melting and solidifying a filler material fed from a welding torch, and stacking the weld bead to form the object. The method comprises: a first forming step of forming the weld bead and stacking the weld bead using a first welding control mode; and a second forming step of forming the weld bead and stacking the weld bead using a second welding control mode with a higher heat input than the first welding control mode. The first welding control mode in the first forming step is a forward and reverse feed control in which the filler material fed from the welding torch is fed forward and reverse, and the current waveform of the power supplied from a power supply to the filler material is synchronized with the forward and reverse feed of the filler material.

Description

Technical Field

[0001] The present invention relates to a method for producing a laminated structure. Background Art

[0002] In recent years, demand for 3D printers as a production tool has been increasing. In particular, research and development are underway for their practical application in the aircraft industry, with applications for metal materials. 3D printers using metal materials utilize heat sources such as laser arcs to melt metal powder or wire, then layer the molten metal to create objects.

[0003] Patent Document 1 describes forming a shaped object by forming a contour portion by lamination and filling the inner side of the contour portion with a metal material in a filling pattern having a waveform of a certain wavelength.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-111582 Summary of the Invention

[0007] [Technical problem to be solved by the invention]

[0008] However, when forming laminated objects, it is necessary to suppress the occurrence of unwelded areas and improve forming efficiency. As described in Patent Document 1, filling the inside of the outline with a fill pattern of a certain wavelength can reduce the number of weld bead starts and ends and improve forming efficiency. However, filling the inside of the outline with a fill pattern of a certain wavelength alone, while reducing the number of weld bead starts and ends, does not effectively suppress the occurrence of unwelded areas.

[0009] Therefore, an object of the present invention is to provide a method for manufacturing a laminated structure that can suppress the occurrence of unwelded portions and efficiently manufacture a laminated structure with high precision.

[0010] Means for solving technical problems

[0011] The present invention includes the following structures.

[0012] A method for manufacturing a laminated object comprises forming deposited weld beads by melting and solidifying a filler material fed from a welding torch and stacking the deposited weld beads to form the object, the method comprising:

[0013] a first forming step of forming the deposited weld beads and stacking them in layers using a first welding control mode;

[0014] In the second forming step, the deposited weld beads are formed and stacked in a second welding control mode having a higher heat input than the first welding control mode.

[0015] The first welding control mode in the first forming step is forward and reverse feed control for forward and reverse feeding the filler material fed from the welding torch and synchronizing the current waveform of the power supplied from the power source to the filler material with the forward and reverse feeding of the filler material.

[0016] Effects of the Invention

[0017] According to the present invention, it is possible to efficiently manufacture a highly precise laminated structure while suppressing the occurrence of unwelded portions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 is a schematic diagram schematically illustrating the structure of a production system for producing a laminated structure using a production method according to an embodiment of the present invention.

[0019] Figure 2 1 is a schematic side view of a laminated structure showing an example of the manufactured laminated structure.

[0020] Figure 3A This is a schematic side view of a stacked structure showing a manufacturing process of the stacked structure in the middle of manufacturing.

[0021] Figure 3B This is a schematic side view of a stacked structure showing a manufacturing process of the stacked structure in the middle of manufacturing.

[0022] Figure 3C This is a schematic side view of a stacked structure showing a manufacturing process of the stacked structure in the middle of manufacturing.

[0023] Figure 4 1 and 2 are diagrams for explaining the outline of forward and reverse feed control. (A) is a side view of the welding torch during forward feed, and (B) is a side view of the welding torch during reverse feed.

[0024] Figure 5 This is a graph showing the relationship between the feeding direction of the filling material and the current during forward and reverse feed control.

[0025] Figure 6 This is an explanatory diagram for explaining the outline of constant voltage power supply control.

[0026] Figure 7 This is a graph showing a current waveform for explaining the outline of pulse power supply control.

[0027] Figure 8 This is a schematic side view of a stacked structure for explaining the method of selecting a welding control mode based on shape.

[0028] Figure 9 It is a cross-sectional view of another laminated structure. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0030] Figure 1 This is a structural diagram of a manufacturing system used for manufacturing the laminated structure of the present invention.

[0031] The manufacturing system 100 of a laminated object of this structure includes a laminated forming device 11 , a controller 13 that performs overall control of the laminated forming device 11 , and a power supply 15 .

[0032] The stacked forming apparatus 11 includes a welding robot 19 having a welding torch 17 mounted on its front end, and a filler material supply unit 21 that supplies a filler material (welding wire) M to the welding torch 17 .

[0033] The welding robot 19 is a multi-joint robot capable of continuously supplying filler material M to a welding torch 17 attached to a distal shaft of a robot arm. The position and posture of the welding torch 17 can be arbitrarily set three-dimensionally within the range of the robot arm's degree of freedom.

[0034] The welding torch 17 has a shield nozzle (not shown) from which shielding gas is supplied. The arc welding method may be a consumable electrode method such as sheathed arc welding or carbon dioxide gas arc welding, or a non-consumable electrode method such as TIG welding or plasma arc welding, and the method is appropriately selected depending on the laminated object to be produced.

[0035] For example, in the case of a consumable electrode type, a contact nozzle is disposed within the shielded nozzle, and the contact nozzle holds the filler material M, to which a melting current is supplied. The welding torch 17 holds the filler material M and generates an arc from the tip of the filler material M in a shielding gas atmosphere. The filler material M is fed from the filler material supply unit 21 to the welding torch 17 via a delivery mechanism (not shown) mounted on a robot arm or the like. As the welding torch 17 moves and the continuously fed filler material M melts and solidifies, a linear weld bead B, representing the molten and solidified filler material M, is formed on the substrate 51, and a laminated object W is formed from this weld bead B.

[0036] After creating the shape data for the stacked object W to be manufactured, the CAD / CAM unit 31 generates shape data representing the shape of each layer, divided into multiple layers. The trajectory calculation unit 33 calculates the movement trajectory of the welding torch 17 based on the generated layer shape data. The storage unit 35 stores the generated layer shape data and the movement trajectory of the welding torch 17.

[0037] The control unit 37 executes a driver program based on the layer shape data stored in the storage unit 35 and the movement trajectory of the welding torch 17 to drive the welding robot 19. Specifically, the welding robot 19, in response to instructions from the controller 13 and based on the movement trajectory of the welding torch 17 generated by the trajectory calculation unit 33, melts the filler material M with an arc and moves the welding torch 17. Thus, the filler material M is melted by the arc, forming a weld bead B on the substrate 51, thereby forming a laminated object W.

[0038] The substrate 51 is made of a metal plate such as a steel plate and is generally larger than the bottom surface (bottommost surface) of the stacked structure W. The substrate 51 is not limited to a plate shape and may be a base body of other shapes such as a block or a rod.

[0039] All commercially available welding wires can be used as the filler material M. For example, wires specified in JIS Z 3312 solid wires for MAG welding and MIG welding for mild steel, high-tensile steel, and low-temperature steel, and JIS Z 3313 flux-cored wires for arc welding for mild steel, high-tensile steel, and low-temperature steel can be used.

[0040] Next, an example of a multilayer structure formed by the production method according to this embodiment will be described.

[0041] Figure 2 This is a schematic side view of a stacked structure showing an example of the stacked structure.

[0042] like Figure 2 As shown, a laminated structure W is formed on a substrate 51 and includes a frame portion 53 and an inner portion 55 formed inside the frame portion 53. Furthermore, the laminated structure W includes an extension portion 57 that bridges the upper ends of the two frame portions 53. Furthermore, in the laminated structure W, for example, the portion surrounded by the frame portion 53 formed on the substrate 51 and the extension portion 57 is used as a cooling flow path.

[0043] However, when forming the aforementioned laminated structure W, the volume of the inner portion of the frame portion 53, which serves as the outer periphery of the structure, varies significantly depending on the height, width, and location of the structure. Therefore, high-precision forming is required. Furthermore, the extension portion 57, which bridges the frame portion 53 and serves as the top portion of the flow path, also requires high-precision forming. Furthermore, since the extension portion 57 is significantly affected by gravity during forming, it must be formed while preventing sagging. Furthermore, the inner forming portion 55 within the frame portion 53 must be formed efficiently while preventing the occurrence of unwelded areas.

[0044] Therefore, in this embodiment, as follows, the control unit 37 controls the power supply 15 and the filler material supply unit 21, switches the welding control mode when the welding torch 17 forms the weld bead B, and thereby shapes the frame portion 53, the extension portion 57, and the internal shaping portion 55.

[0045] Figure 3A to Figure 3C It is a schematic side view of a laminated object in the middle of manufacturing a laminated object. In addition, in the following forming process, each welding control mode can be switched according to the shape of the object and welding conditions to perform forming.

[0046] (Frame forming process)

[0047] like Figure 3A As shown, two frame portions 53 are formed on a substrate 51. When forming the frame portions 53, the control unit 37 forms a deposited weld bead B1 in a first welding control mode (a first forming step).

[0048] Specifically, the control unit 37 forms the deposited weld bead B1 by forward and reverse feed control as the first welding control mode.

[0049] like Figure 4 As shown, in the forward and reverse feed control, when the deposited weld bead B1 is formed by the welding torch 17, the control unit 37 controls the filler material supply unit 21 to alternately switch the forward feed ( Figure 4 (A) in the direction of arrow α), and the reverse feed ( Figure 4 (B) in the direction of arrow β). And, as Figure 5 As shown, the control unit 37 controls the power supply 15 to synchronize the waveform of the current I supplied to the filling material M with the forward and reverse feeding of the filling material M that is alternately switched.

[0050] In this forward and reverse feed control, when the filler material M is fed forward, the front end of the filler material M reaches the molten pool Mp and becomes short-circuited, the arc Ar is extinguished, and the current I decreases (see Figure 4 (B)). In this state, the filler material M is fed in reverse. Then, the droplet at the front end of the filler material M is cut off and the short circuit is opened, and the arc Ar is generated again (refer to Figure 4 (A)). In this cycle, by synchronizing the current waveforms, stable droplet transfer can be performed, and a stable weld bead B1 can be formed with a low heat input.

[0051] In other words, by performing this forward and reverse feed control, the weld bead B1 can be formed with a lower heat input, and the weld bead B1 can be formed into a precise shape. Therefore, the frame portion 53 formed using the first welding control mode, which includes this forward and reverse feed control, is formed with high precision.

[0052] (Extension part forming process)

[0053] like Figure 3B As shown, the extension 57 of the bridge is formed at the upper end of the two formed frame portions 53. When forming the extension 57, the control unit 37 also forms the deposited weld bead B1 using the first welding control mode including forward and reverse feed control (first forming step).

[0054] Specifically, the welding torch 17 uses the side of the upper end of each frame 53 as a base, and then sequentially forms and connects the weld beads B1 extending laterally from this base through forward and reverse feed control. This forms an extension 57 comprising multiple weld beads B1 at the upper end of the frame 53. Although gravity acts on the formed weld beads B1, the weld beads B1 formed through forward and reverse feed control are formed with low heat input, thus suppressing sagging due to the influence of gravity. While it is preferred that the weld beads B1 forming the extension 57 be stacked sequentially from both frames 53 and connected in the middle, it is also possible to stack the beads B1 sequentially from one frame 53 to the other.

[0055] (Internal molding process)

[0056] like Figure 3C As shown, the internal forming portion 55 is formed inside the frame portion 53. When forming the internal forming portion 55, the control unit 37 forms the deposited weld bead B2 in the second welding control mode (second forming step).

[0057] Specifically, the control unit 37 forms the deposited weld bead B2 by constant voltage power supply control as the second welding control mode. In this constant voltage power supply control, the power supply 15 supplies current to the filler material M at a constant voltage.

[0058] In this constant voltage power supply control, the control unit 37 controls the filler material supply unit 21 and the power source 15 to feed the filler material M from the welding torch 17 at a constant speed and to generate an arc at a constant voltage.

[0059] Figure 6 1 is an explanatory diagram showing characteristic curves of the arc Ar in constant voltage power supply control, R1 represents the arc characteristic curve when the arc length is L1, and R2 represents the arc characteristic curve when the arc length is L2.

[0060] like Figure 6As shown, when the arc Ar is generated by the voltage E, if the arc length increases from L1 to L2, the current value decreases from I1 to I2. As the current value decreases, the melting rate of the filler material M decreases, the tip of the filler material M approaches the base, and the arc length decreases. Furthermore, if the arc length decreases from L2 to L1, the current value increases from I2 to I1, the melting rate of the filler material M increases, and the arc length increases.

[0061] In this manner, in constant voltage power supply control, the deposited weld bead B2 can be formed at a high current density and at a high speed due to the self-control of the arc length.

[0062] In addition, as the second welding control mode, pulse power supply control can also be used. In this pulse power supply control, Figure 7 As shown, power supply control is performed by periodically passing a high current, namely a pulse current Ip, followed by a lower current, namely a base current Ib. This pulse power supply control concentrates the arc by periodically passing the pulse current Ip, enabling the rapid formation of the deposited weld bead B2.

[0063] Thus, the second welding control mode, which includes constant voltage power supply control or pulse power supply control, can form a deposited weld bead B2 with a higher heat input than the deposited weld bead B1 formed by forward and reverse feed control in the first welding control mode. Consequently, the deposited weld bead B2 is well fused to the base substrate 51 and the underlying deposited weld bead B2, and is also formed without a gap with the frame 53. Thus, by forming the internal shaped portion 55 with the deposited weld bead B2 formed in the second welding control mode, the inner portion of the frame 53 can be quickly filled while suppressing the occurrence of unwelded areas.

[0064] Through the above process, a laminated structure W is manufactured, in which the inner structure 55 is formed inside the frame 53 and the bridge extension 57 is formed at the upper end of the two frame parts 53 (see Figure 2 ).

[0065] As described above, according to the method for manufacturing a laminated object according to this embodiment, in the first forming step, a deposited weld bead is formed using a first welding control mode, which synchronizes the forward and reverse feed of the filler material M fed from the welding torch 17 with the current waveform of the power supplied to the filler material M from the power source 15 and the forward and reverse feed of the filler material M. This allows for the formation of a precise deposited weld bead B1 with a relatively low heat input. Furthermore, the first forming step can be selected based on the location of the object to form an appropriate deposited weld bead B1 and shape the object. For example, in locations where precision is required or where gravity is a factor, selecting the first forming step that forms the deposited weld bead B1 using the first welding control mode, which includes forward and reverse feed control, allows for high-precision forming, suppressing the occurrence of head collapse and the like.

[0066] Furthermore, in the second forming step, the deposited weld bead B2 is formed using constant voltage power supply control, where a constant voltage current is supplied from the power supply 15, or pulse power supply control, where a pulse current is periodically supplied. This allows the deposited weld bead B2 to be formed with a higher heat input, thereby improving manufacturing efficiency while suppressing the occurrence of unwelded areas.

[0067] Furthermore, the frame portion 53 is formed with high shape accuracy in the first forming step, and the weld bead B2 is formed inside the frame portion 53 with high input heat in the second forming step, thereby improving overall productivity and suppressing the occurrence of unwelded portions in the laminated structure W.

[0068] Furthermore, when forming the extension portion 57 by stacking the portions extending laterally from the base including the upper edge of the frame portion 53, the first forming step is performed in which a precise weld bead B1 can be formed with relatively low heat input, thereby enabling the extension portion 57 to be formed while suppressing sagging due to the influence of gravity.

[0069] In the above embodiment, the case where the shaping of the frame portion 53 and the extension portion 57 is set to the first welding control mode and the shaping of the internal shaping portion 55 is set to the second welding control mode is illustrated, but the welding control mode can also be selected and set based on the three-dimensional shape data of the shaped stacked structure.

[0070] Here, an example of selecting a welding control mode based on the three-dimensional shape data of a formed object will be described.

[0071] First, based on the three-dimensional shape data of the laminated object W created by the CAD / CAM unit 31, shape data, which is slice data obtained by cross-sectioning the weld beads B in the laminated object W along the lamination direction, is created.

[0072] Next, the trajectory calculation unit 33 creates a stacking plan for the deposited weld bead B based on the created shape data.

[0073] Then, based on the created stacking plan of the deposited weld bead B, the first welding control mode or the second welding control mode is selected.

[0074] Specifically, the cross-sectional area of the formed weld bead B is compared with a preset cross-sectional area threshold. If the cross-sectional area of the weld bead B is below the threshold, the first welding control mode, which is forward and reverse feed control, is selected. If the cross-sectional area of the weld bead B is above the threshold, the second welding control mode, which is constant voltage power supply control or pulse power supply control, is selected.

[0075] By selecting this welding control mode, a welding control mode for forming the weld bead B can be appropriately selected in advance based on the stacking plan and the object can be formed. Furthermore, the conditions for stacking the weld bead B can be flexibly set.

[0076] Furthermore, the shape of the base during the formation of the weld bead B can be measured, and the welding control mode can be selected based on the measurement results. By selecting the welding control mode based on this shape, for example, when an additional weld bead B not included in the stacking plan is added and stacked, the additional weld bead B can be formed under appropriate stacking conditions.

[0077] Here, an example of selecting a welding control mode based on the shape of the base will be described.

[0078] Figure 8 This is a schematic side view of a stacked structure for explaining the method of selecting a welding control mode based on shape.

[0079] like Figure 8 As shown, for example, a defect C consisting of a valley-shaped depression may form at the boundary between adjacent weld beads B2 in the upper portion of the laminated structure W. In other words, even though the laminated structure W is formed by stacking weld beads B1 and B2 according to the stacking plan, there are cases where the target shape deviates. In this case, the defect C is repaired by adding a stacking weld bead B to the defect C.

[0080] When the deposited weld bead B is additionally laminated, the shape of the upper surface of the laminated structure W serving as its base is measured, and a welding control mode is selected based on the measurement result.

[0081] Specifically, a shape sensor such as a three-dimensional laser measuring device or a three-dimensional shape measurement camera is used to measure the shape of the base of the weld bead B, that is, the shape of the top surface of the laminated structure W. Next, based on the measurement results, the deposited amount of the formed weld bead B is calculated. Then, based on the calculated deposited amount of the weld bead B, either the first welding control mode or the second welding control mode is selected.

[0082] For example, the cross-sectional area is calculated based on the deposited amount of the additional weld bead B and compared with a preset cross-sectional area threshold. If the cross-sectional area of the additional weld bead B is less than the threshold, the first welding control mode, which uses forward and reverse feed control, is selected. If the cross-sectional area of the additional weld bead B is greater than the threshold, the second welding control mode, which uses constant voltage power supply control or pulse power supply control, is selected.

[0083] By selecting this welding control mode, the welding conditions of the weld bead B can be flexibly selected according to the shape of the base, and an appropriate weld bead B can be formed.

[0084] Next, another example of manufacturing a shaped object using the manufacturing method according to the above-described embodiment will be described. Figure 9 It is a cross-sectional view of another stacked structure W1.

[0085] like Figure 9 As shown, the laminated structure W1 is formed on a base material 61 placed on a substrate 51. The base material 61 has a trapezoidal cross-section, with its side surfaces inclined upward. Weld beads B1 and B2 are formed on a base surface 63 formed by the inclined side surfaces of the base material 61. The base surface 63 has an extension 67 formed by the weld bead B1 and multiple weld bead layers 69 formed by the weld bead B2. The extension 67 formed by the weld bead B1 is formed along the side S, and a weld bead layer 69 formed by the weld bead B2 is stacked on top of the extension 67.

[0086] Next, the process of forming the multilayer structure W1 will be described.

[0087] First, the extension portion 67 is formed on the base surface 63 of the base material 61. When forming the extension portion 67, the deposited weld bead B1 is formed and formed using the first welding control mode including forward and reverse feed control (first forming step).

[0088] Specifically, the welding torch 17 uses the base surface 63 of the substrate 61 as a base, and sequentially forms and connects the deposited weld beads B1 by forward and reverse feed control, extending laterally from this base. This forms an extended portion 67 composed of multiple deposited weld beads B1 on the base surface 63. Although gravity acts on the formed deposited weld beads B1, the deposited weld beads B1 formed using forward and reverse feed control are formed with relatively low heat input, thus suppressing drooping due to the influence of gravity.

[0089] Next, using the extension 67 as a base, a deposited weld bead B2 is formed on the upper portion of the extension 67 by a second welding control mode including constant voltage power supply control or pulse power supply control, and a weld bead layer 69 is stacked (second forming step).

[0090] This deposited weld bead B2 is then well fused to the extension 67 serving as the base and the underlying weld bead layer 69, and is also formed without a gap relative to the base surface 63. Thus, by forming the weld bead layer 69 using the deposited weld bead B2 formed in the second welding control mode, the occurrence of unwelded portions can be suppressed, and the weld bead layer 69 can be efficiently stacked on top of the extension 67.

[0091] According to this other embodiment, a second forming step is used to laminate the weld bead B2 onto the extension portion 67 formed in the first forming step. This allows the weld bead B2 to be quickly laminated onto the extension portion 67, using the extension portion 67 as a base. This prevents the formation of unwelded areas and improves overall productivity.

[0092] In this way, the present invention is not limited to the above-mentioned embodiments. Combining the various structures of the embodiments with each other, and changing and applying the contents made by those skilled in the art based on the description in the specification and known technologies are also the intended contents of the present invention and are included in the scope of protection.

[0093] As described above, this specification discloses the following matters.

[0094] (1) A method for manufacturing a laminated object, wherein a weld bead is formed by melting and solidifying a filler material fed from a welding torch and stacking the weld beads to form an object, the method comprising:

[0095] a first forming step of forming and laminating the deposited weld beads using a first welding control mode; and

[0096] In the second forming step, the deposited weld beads are formed and stacked in a second welding control mode having a higher heat input than the first welding control mode.

[0097] The first welding control mode in the first forming step is forward and reverse feed control for forward and reverse feeding the filler material fed from the welding torch and synchronizing the current waveform of the power supplied from the power source to the filler material with the forward and reverse feeding of the filler material.

[0098] According to the method for manufacturing a laminated object with this structure, in the first forming step, a deposited weld bead is formed using a first welding control mode, which synchronizes the current waveform of the power supplied to the filler material from the power supply with the forward and reverse feed of the filler material. This allows for the formation of a precise weld bead with relatively low heat input. Furthermore, the first forming step can be selected based on the location of the object to form an appropriate weld bead, thereby forming the object. For example, in areas of the object requiring high precision or affected by gravity, selecting the first forming step that forms the weld bead using the first welding control mode, which includes forward and reverse feed control, allows for high-precision forming, suppressing the occurrence of head collapse. Furthermore, in the second forming step, using a second welding control mode that does not perform forward and reverse feed control, the weld bead is formed using a higher heat input, improving manufacturing efficiency and suppressing the occurrence of unwelded areas.

[0099] (2) In the method for manufacturing a laminated object described in (1), the second welding control mode in the second forming step is constant voltage power supply control in which a constant voltage current is supplied from the power source or pulse power supply control in which a pulse current is periodically supplied.

[0100] According to the method for manufacturing a laminated structure with this structure, in the second forming step, a deposited weld bead is formed using constant voltage power supply control, where a constant voltage current is supplied from a power source, or pulse power supply control, where a pulse current is periodically supplied. This allows the deposited weld bead to be formed with a higher heat input, thereby suppressing the occurrence of un-welded areas and improving manufacturing efficiency.

[0101] Furthermore, by forming a first forming step based on a first welding control mode, a portion requiring precision or a portion affected by gravity, etc. is formed, and by forming a second forming step based on a second welding control mode, a portion requiring effective forming and suppressing internal defects is formed, thereby enabling high-quality formed objects to be manufactured with high precision and efficiency.

[0102] (3) In the method for manufacturing a laminated structure described in (1) or (2), the frame portion is formed in the first forming step, and the inner forming portion is formed inside the frame portion in the second forming step.

[0103] According to the method for manufacturing a laminated structure with this structure, the frame portion is formed with high shape accuracy in the first forming step, and a weld bead is formed inside the frame portion with high input heat in the second forming step, thereby improving overall productivity and suppressing the occurrence of unwelded portions.

[0104] (4) In the method for manufacturing a laminated structure according to any one of (1) to (3), the first forming step forms the extending portion by laminating the deposited weld beads so as to extend laterally from the base portion.

[0105] According to the method for manufacturing a stacked structure of this structure, when the layers are stacked so as to extend laterally from the base to form the extending portion, the first forming step is performed in which a precise weld bead can be formed with a relatively low heat input, thereby suppressing sagging due to the influence of gravity and forming the extending portion.

[0106] (5) In the method for manufacturing a laminated structure described in (4), the deposited weld bead is laminated on an upper portion of the protruding portion in the second forming step.

[0107] According to the method for manufacturing a laminated structure with this structure, a deposited weld bead is laminated in the second molding step on top of the extension formed in the first molding step. This allows the extension to be used as a base for rapidly laminating the deposited weld bead on the extension, thereby suppressing the occurrence of un-welded areas and improving overall productivity.

[0108] (6) In the method for manufacturing a laminated structure according to any one of (1) to (5), shape data of a cross section along the lamination direction of the deposited weld bead in the structure is created based on the three-dimensional shape data of the structure being formed.

[0109] creating a stacking plan for the weld deposit based on the shape data,

[0110] The first welding control mode or the second welding control mode is selected based on the stackup plan of the weld deposit.

[0111] According to the method for manufacturing a laminated object of this structure, shape data is created based on the object's three-dimensional shape data, and a weld bead stacking plan is created based on this shape data. Furthermore, based on this stacking plan, a first welding control mode or a second welding control mode is selected for forming the weld bead. In other words, based on the stacking plan, the welding control mode for forming the weld bead can be preselected and the object can be formed. Furthermore, the conditions for stacking the weld bead can be flexibly set.

[0112] (7) In the method for manufacturing a laminated structure according to any one of (1) to (6), when forming the weld bead, the shape of the base of the weld bead is measured,

[0113] Based on the measurement results, the amount of the formed weld bead is calculated.

[0114] Based on the calculated deposition amount, the first welding control mode or the second welding control mode is selected.

[0115] According to the method for manufacturing a laminated structure of this structure, the shape of the base of the weld bead is measured, the deposit amount of the formed weld bead is calculated based on the measurement result, and the first welding control mode or the second welding control mode is selected based on the calculated deposit amount. This allows for flexible selection of weld bead welding conditions based on the base shape, enabling the formation of an appropriate weld bead.

[0116] This application is based on Japanese patent application (Japanese Patent Application No. 2020-121580) filed on July 15, 2020, the contents of which are incorporated herein by reference.

[0117]

Explanation of symbols

[0118] 17 Welding Torch

[0119] 53 frame

[0120] 55 Internal shaping department

[0121] 57, 67 extension

[0122] B, B1, B2 deposited welds

[0123] M Filling material

[0124] W, W1 stacked shapes.

Claims

1. A method for manufacturing a laminated object, comprising forming a plurality of deposited weld beads by melting and solidifying a filler material fed from a welding torch and stacking the weld beads to form the object, the method comprising: a first forming step of forming a first weld deposited bead of the plurality of weld deposited beads and stacking the first weld deposited bead using a first welding control mode; and In a second forming step, a second weld bead is formed by a second welding control mode having a higher heat input than the first welding control mode, and the second weld bead is stacked. The first welding control mode in the first forming step is a forward and reverse feed control in which the filler material fed from the welding torch is fed forward and reverse, and the current waveform of the power supplied from the power source to the filler material is synchronized with the forward and reverse feed of the filler material. The second welding control mode in the second forming step is a constant voltage power supply control in which a constant voltage current is supplied from the power source or a pulse power supply control in which a pulse current is periodically supplied. The frame is formed by the first forming step, The inner forming portion is formed inside the frame portion through the second forming step. The cross-sectional area of the formed deposited weld bead is compared with a preset cross-sectional area threshold value, and when the cross-sectional area of the deposited weld bead is less than the threshold value, the first welding control mode is selected, and when the cross-sectional area of the deposited weld bead is greater than the threshold value, the second welding control mode is selected.

2. The method for manufacturing a laminated structure according to claim 1, wherein: The first forming step forms the extension portion by laminating the first deposited weld bead so as to extend between the pair of base portions. The base portion is a side portion of the upper end of the frame portion.

3. The method for manufacturing a laminated structure according to claim 2, wherein: The second weld bead is laminated on the upper portion of the extension portion in the second forming step.

4. The method for producing a laminated structure according to any one of claims 1 to 3, wherein: Based on the three-dimensional shape data of the object being formed, shape data of a cross section along the stacking direction of the plurality of weld beads in the object is created; creating a stacking plan for the plurality of weld deposits based on the shape data, The first welding control mode or the second welding control mode is selected based on the stackup plan of the plurality of weld deposits.

5. The method for producing a laminated structure according to any one of claims 1 to 3, wherein: When forming the weld bead, measuring the shape of the base of the weld bead, Based on the measurement results, the amount of the formed weld bead is calculated. Based on the calculated deposition amount, the first welding control mode or the second welding control mode is selected.

6. The method for manufacturing a laminated structure according to claim 4, wherein: When forming the weld bead, measuring the shape of the base of the weld bead, Based on the measurement results, the amount of the formed weld bead is calculated. Based on the calculated deposition amount, the first welding control mode or the second welding control mode is selected.

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