Welding condition setting device, welding condition setting method, and program

Abstract

The present invention provides a technique for setting a welding condition for laminating and molding a thin structure or a structure which has a shape in which a slope or angle thereof changes. A welding condition setting device that sets a welding condition when laminating and molding a molding target material by the WAAM method, said welding condition setting device having: a means for calculating a welding condition corresponding to the molding width of the molding target material by referring to a database which defines a correspondence relation between the molding width and the welding condition; a means for calculating the molding height of the molding target material when molding according to the calculated welding condition by referring to a database which defines a correspondence relation between the welding condition and the molding height; and a means for setting the molding target material width at a position corresponding to an end section of the molded object formed when the molding target material is molded at the calculated molding height as the molding width of the molding target material to be molded next.

Description

Welding condition setting device, welding condition setting method and program

[0001] This disclosure claims priority to Japanese Patent Application No. 2024-022134, filed on February 16, 2024, the contents of which are incorporated herein by reference.

[0002] A wire arc additive manufacturing (WAAM) method (arc and wire additive manufacturing) has been proposed, which builds a desired shape by layering weld beads formed by melting and solidifying a filler metal. For example, Patent Literature 1 (PTL 1) discloses a method for creating a three-dimensional (3D) shape model of the object from shape data, breaking down the three-dimensional shape model into multiple linear models, and planning welding passes for forming weld beads along the linear models. Patent Literature 1 also discloses a manufacturing example in which a layer is formed by multiple adjacent weld beads and these layers are stacked vertically, as well as a manufacturing example in which the torch is oriented downward and stacked vertically during manufacturing. Meanwhile, there is a need for additive manufacturing to build thin structures, each layer corresponding to the width of one weld bead pass, and structures with inclined shapes, shapes with varying angles, overhanging shapes, etc. To meet these needs, it is necessary to appropriately set welding conditions for additive manufacturing.

[0003] Japanese Patent Application Laid-Open No. 2023-29198

[0004] A method for setting welding conditions for additive manufacturing of thin-walled structures and structures with shapes that vary in slope or angle is provided.

[0005] The present disclosure provides a welding condition setting device, a welding condition setting method, and a program that can solve the above-mentioned problems.

[0006] According to one aspect of the present disclosure, a welding condition setting device is a welding condition setting device that sets welding conditions when additively manufacturing an object to be manufactured using the WAAM method, and includes: a means for calculating welding conditions corresponding to the manufacturing width of the layer to be manufactured by referring to a database that defines the correspondence between the manufacturing width and the welding conditions; a means for calculating the manufacturing height of the layer to be manufactured when manufactured using the calculated welding conditions by referring to a database that defines the correspondence between the welding conditions and the manufacturing height; and a means for setting the width of the object to be manufactured at a position corresponding to the edge of the object that will be created when the layer to be manufactured is manufactured at the calculated manufacturing height as the manufacturing width of the layer to be manufactured next.

[0007] According to one aspect of the present disclosure, a welding condition setting method is a welding condition setting method for setting welding conditions when additively manufacturing an object to be manufactured using the WAAM method, and includes the steps of: calculating welding conditions corresponding to the manufacturing width of the layer to be manufactured by referring to a database that defines the correspondence between the manufacturing width and the welding conditions; calculating the manufacturing height of the layer to be manufactured when manufactured using the calculated welding conditions by referring to a database that defines the correspondence between the welding conditions and the manufacturing height; and setting the width of the object to be manufactured at a position corresponding to the edge of the object that will be created when the layer to be manufactured is manufactured at the calculated manufacturing height as the manufacturing width of the layer to be manufactured next.

[0008] According to one aspect of the present disclosure, the program causes a computer to execute a process for setting welding conditions when additively manufacturing an object to be manufactured using the WAAM method, the process comprising the steps of: calculating welding conditions corresponding to the manufacturing width of the layer to be manufactured by referring to a database that defines the correspondence between the manufacturing width and the welding conditions; calculating the manufacturing height of the layer to be manufactured when manufactured using the calculated welding conditions by referring to a database that defines the correspondence between the welding conditions and the manufacturing height; and setting the width of the object to be manufactured at a position corresponding to the edge of the object that will be created when the layer to be manufactured is manufactured at the calculated manufacturing height as the manufacturing width of the layer to be manufactured next.

[0009] The above-described welding condition setting device, welding condition setting method, and program enable additive manufacturing of thin-walled structures and structures having shapes with varying inclinations or angles.

[0010] FIG. 1 is a block diagram illustrating an example of an additive manufacturing system according to an embodiment. FIG. 2 is a diagram illustrating an additive manufacturing method according to an embodiment. FIG. 3 is a diagram illustrating an example of an algorithm for setting welding conditions according to an embodiment. FIG. 4 is a diagram illustrating an example of a database according to an embodiment. FIG. 5 is a first diagram illustrating setting a torch angle according to an embodiment. FIG. 6 is a second diagram illustrating setting a torch angle according to an embodiment. FIG. 7 is a first diagram illustrating setting an offset of a torch position according to an embodiment. FIG. 8 is a second diagram illustrating setting an offset of a torch position according to an embodiment. FIG. 9 is a flowchart illustrating an example of a welding condition setting process according to an embodiment. FIG. 11 is a diagram illustrating an example of a hardware configuration of a control device according to an embodiment.

[0011] <Embodiment> A method for setting welding conditions for WAAM-based additive manufacturing according to the present disclosure will be described below with reference to the drawings. (Configuration) FIG. 1 is a block diagram illustrating an example of an additive manufacturing system according to an embodiment. The additive manufacturing system 100 includes a welding system 1 and a control device 10. The welding system 1 includes a welding robot 2, a welding machine 3, a wire feeder 4, a torch 5, and the like. The welding system 1 executes WAAM-based additive manufacturing based on instructions from the control device 10 and produces a structure 6 on a positioning device 7. The welding system 1 performs manufacturing using short-circuit transfer MIG welding. Short-circuit transfer MIG welding is characterized by low heat input (low molten pool temperature) and high viscosity of the weld bead. By using short-circuit transfer MIG welding, deformation of the weld bead due to gravity can be ignored even when the torch 5 is positioned not only vertically downward but also diagonally or sideways (horizontally). This allows for the production of a structure of a desired shape in the same manner as when the torch 5 is positioned downward. Control device 10 includes a shape data acquisition unit 11, a welding condition setting unit 12, a control unit 13, and a storage unit 14. In the configuration example of FIG. 1 , control device 10 includes welding condition setting unit 12, but welding condition setting unit 12 may be provided as a device separate from control device 10.

[0012] The shape data acquisition unit 11 acquires shape data of the object to be molded. The shape data is, for example, a three-dimensional model (CAD data) representing the shape of the object to be molded. The width and size of the object to be molded at any position can be calculated from the shape data. The welding condition setting unit 12 sets welding conditions such as welding speed, voltage, current, wire feed rate, head movement amount, and torch angle. The control unit 13 controls the welding system 1 based on the welding conditions set by the welding condition setting unit 12 to perform WAAM-type additive manufacturing using short-circuit transfer MIG welding. The memory unit 14 stores the shape data acquired by the shape data acquisition unit 11, the welding conditions set by the welding condition setting unit 12, a database (described below) used to calculate the welding conditions, and the like.

[0013] Next, with reference to FIG. 2 , the additive manufacturing method according to this embodiment will be described. A part 20 shown in the left diagram of FIG. 2 is an example of a manufacturing target. A molded object 21 shown in the right diagram is a schematic diagram of a molded object obtained by additive manufacturing of the part 20. The molded object 21 is constructed by stacking rectangular blocks. The bottom block 26 is called the first layer, and the block 27 above it is called the second layer, etc. One block represents the molded portion formed by one welding (one pass). The horizontal length of the block is called the mold width, and the vertical length (thickness) of the block is called the mold height. The molded object 21 is constructed by stacking blocks in layers, with each layer consisting of only one block. This type of configuration is called a one-pass configuration. For example, a thin-walled structure would be a one-pass configuration. In contrast, when additively manufacturing a thick structure, multiple welding processes are required for each layer to achieve the desired thickness, meaning that each layer is made up of multiple blocks (multiple passes) in the horizontal direction.

[0014] In the case of a multi-pass structure, the final build width can be adjusted to the target width by adjusting the welding conditions during the multiple welding passes performed to form one layer. In contrast, when additively manufacturing a single-pass structure, the build width required by the shape data must be achieved with a single welding pass for each layer. To control the build width, the welding conditions must be appropriately set. In other words, the build width can be changed by changing the welding conditions. Therefore, in this embodiment, the width of the object to be built at a position corresponding to the block of each layer is acquired by referring to the shape data, and the acquired width is set as the build width. Then, welding conditions corresponding to the set build width are set, and the object indicated by the shape data is built by performing short-circuit transfer MIG welding. For example, the current, voltage, and wire feed rate are kept constant to maintain a constant amount of melted wire, and the build width is changed by changing the speed at which the torch 5 is moved during building. In the case of the object 21 illustrated in FIG. 2 , the object 21 can be built by setting the welding conditions (current, voltage, and wire feed rate) constant and adjusting the welding speed according to the build width.

[0015] FIG. 3 shows an example of an algorithm for setting welding conditions according to an embodiment. The welding conditions for the Nth layer are determined by the build width of the Nth layer. Therefore, first, a portion of the object to be built corresponding to the block of the Nth layer is identified based on the shape data, and the width of that portion is calculated from the shape data. For example, if the block of the Nth layer is block 28 in FIG. 2, the length indicated by arrow 29 on part 20 is the width of the object to be built. The calculated width is then set as the build width of the Nth layer. Once the build width is set, the welding conditions for building with that build width are calculated. For example, a database specifying the correspondence between the build width and the welding conditions is prepared, and the welding conditions corresponding to the build width of the Nth layer are obtained by referring to this database. When welding is performed under certain welding conditions, the build height is determined in the same way as the build width is determined. For example, a database specifying the correspondence between the build height and the welding conditions (or a database specifying the correspondence between the build height and the build width) is prepared, and the build height of the Nth layer when welding is performed under the welding conditions corresponding to the build width of the Nth layer is calculated by referring to this database. Once the build height of the Nth layer has been calculated, the width of the object to be built at a position corresponding to the sum of the build heights of the layers up to the Nth layer is obtained by referring to the shape data. The position corresponding to the sum of the build heights is not a position vertically elevated from the bottom surface of the object by the sum of the build heights, but a position advanced along the shape of the object by the sum of the build heights from the end of the bottom surface of the object toward the other end of the object. The width obtained from the shape data becomes the build width of the N+1th layer. As in the case of the Nth layer, the database is referenced to determine the welding conditions corresponding to the build width of the N+1th layer, and the build height of the N+1th layer is calculated from the welding conditions. The same process is repeated thereafter to set the welding conditions for each layer. This process is repeated until the block of the N+kth layer reaches the other end of the object.

[0016] FIG. 4 shows an example of a database that defines the correspondence between build widths and welding conditions, and another example of a database that defines the correspondence between build heights and welding conditions. The vertical axis of FIG. 4 represents build widths or build heights, and the horizontal axis represents welding speeds. Line 41 is an example of a database that defines the correspondence between build widths and welding conditions. Line 42 is an example of a database that defines the correspondence between build heights and welding conditions. For example, when the build width of the Nth layer is X1 (mm), the welding condition setting unit 12 calculates the welding speed X2 (m / min) for the Nth layer by referring to line 41 stored in the memory unit 14. The welding condition setting unit 12 calculates the build height X3 (mm) for the Nth layer that corresponds to the welding speed X2 (m / min) for the Nth layer by referring to line 42 stored in the memory unit 14. In the above explanation, only the welding speed is changed depending on the build width, but it is also possible to prepare similar databases for other welding conditions, such as a database that specifies the correspondence between current and voltage and build width, and a database that specifies the correspondence between current and voltage and build height, and to calculate values ​​corresponding to the build width for welding conditions other than the welding speed by referring to these databases.

[0017] Next, we will explain how to set the torch angle, one of the welding conditions. When using MIG welding with short-circuit transfer, the angle of the torch 5 can be changed from horizontal to vertical, allowing blocks to be stacked in the direction of the torch angle. For example, to form the part surrounded by circle 22 in Figure 2, the direction of the torch 5 is set in the direction indicated by arrow 24. To form the part surrounded by circle 23, the direction of the torch 5 is set in the direction indicated by arrow 25. By tilting the torch angle during printing, it is possible to form an object 21 with a tilted shape.

[0018] The welding conditions (welding speed, torch angle) are set based on the width and orientation of the object to be formed, and after forming, the width and orientation of the object to be formed for the next layer are specified based on the height of the object to be formed. By repeating this process of setting the next welding conditions based on the specified width and orientation of the object, the width of the object to be formed changes, as in object 21, making it possible to form an object with an inclined shape.

[0019] Next, we will explain the creation of a shape with a constant build width and variable posture (angle) with reference to Figures 5A and 5B. When the build width is constant, the welding speed is constant. The object to be built is divided into multiple blocks based on the build height determined by the welding speed, and each block is built in one pass. At this time, the torch angle is changed based on the block angle for each layer. The build direction of the object to be built (block inclination) and the torch angle coincide with each other. Graph 51 in Figure 5A shows the change in torch angle. The vertical axis of graph 51 represents the torch angle, and the horizontal axis represents the layer. A torch angle of 0 degrees indicates the angle when the tip of the torch 5 is pointing vertically downward. As the direction of the tip of the torch 5 changes clockwise from 0 degrees, the torch angle is the angle at which the angle between the torch 5 and the vertical axis increases. As shown in graph 51, the torch angle is 0 degrees from layer 0 to layer T1, and increases at a constant rate from layer T1 to layer T2. The torch angle from layer T2 to layer T3 is 90 degrees. Figure 52 in Figure 5B shows an example of a structure resulting from additive manufacturing performed while maintaining the welding speed, current, voltage, and wire feed rate constant and varying the torch angle as shown in graph 51. The structure 53 is a structure created by moving the torch 5 in the front-to-back direction of the page and layering it one layer at a time. As shown in the figure, a structure 53 shaped like a portion of a cylindrical cross section is obtained. As shown in Figures 5A and 5B, by finely adjusting the torch angle depending on the shape of the object, structures with varying angles can be created. Similarly, by changing the torch angle to match the shape of the object to be created, an overhanging structure can be created.

[0020] Next, a method for setting the head movement amount, which is one of the welding conditions, will be described. For example, to form the portion surrounded by circle 22 in Fig. 2, the position of the head holding the torch 5 is shifted to the right side of the paper, layer by layer. The welding condition setting unit 12 calculates the center position in the left-right direction of the paper of the position corresponding to each layer of the object to be formed, based on the shape data, and moves the head to the calculated position, thereby forming an inclined shape.

[0021] Next, the fabrication of a tapered object will be described with reference to FIGS. 6A and 6B . Part 60 shown in FIG. 6A is an example of a tapered object. Graph 61 in FIG. 6B shows the build width and offset amount depending on the height of part 60. The vertical axis of graph 61 indicates the build width or offset amount, and the horizontal axis indicates the height (layers). As already explained, the build width can be changed by changing the welding speed. To build part 60, it is necessary to increase the build width while offsetting torch 5 to the left of the paper so that the right side surface 64 of part 60 is vertical. Line 62 indicates the build width depending on the height (number of layers) of part 60, and line 63 indicates the offset amount of the head holding torch 5 depending on the height (number of layers) of part 60. For example, based on the shape data of part 60, welding condition setting unit 12 calculates the center position in the horizontal direction of the paper of the positions corresponding to each layer of part 60, and calculates the welding speed depending on the build width of the positions corresponding to each layer of part 60. Then, the difference between the center position of the (N-1)th layer and the center position of the Nth layer is calculated as the offset amount for forming the Nth layer. Line 62 represents the offset amount for each layer calculated in this manner. By controlling the welding system 1 based on the calculated offset amount and welding speed, the control unit 13 can form an object having a tapered shape like part 60.

[0022] (Operation) Next, the flow of the welding condition setting method of this embodiment will be described. FIG. 7 is a flowchart showing an example of the welding condition setting process according to this embodiment. The shape data acquisition unit 11 acquires shape data of the object to be formed (step S11). For example, the shape data is shape data of a thin-walled structure having a single pass. Next, the welding condition setting unit 12 sets a variable N, which indicates the object for which the welding conditions are to be set, to 1 (step S12). Next, the welding condition setting unit 12 calculates the build width of the Nth layer (step S13). For example, when N = 1, the welding condition setting unit 12 refers to the shape data and calculates the width of the bottom surface of the object to be formed as the build width. When N > 1, the welding condition setting unit 12 calculates the sum of the build heights up to the (N-1)th layer, and calculates the width of the object at a position corresponding to the sum of the build heights in the shape data as the build width. Next, the welding condition setting unit 12 calculates the welding conditions for the Nth layer (step S14). For example, the welding condition setting unit 12 calculates the welding speed for the Nth layer by referring to a database that defines the correspondence between the build width and the welding speed, as shown in FIG. 4 . For example, the welding condition setting unit 12 calculates the inclination angle of the object to be built at a height position corresponding to the Nth layer in the shape data, and sets a torch angle such that the torch 5 is tilted by the same amount as the calculated angle. The inclination angle of the object to be built can be obtained by calculating the angle between a line connecting the center positions of the object at each height and a horizontal plane. For example, the welding condition setting unit 12 calculates the horizontal center positions of the object to be built at height positions corresponding to the Nth layer and the (N-1)th layer in the shape data, and sets the difference between the coordinates of the Nth layer and the coordinates of the (N-1)th layer as the horizontal offset of the head.

[0023] Next, the welding condition setting unit 12 calculates the build height of the Nth layer (step S15). For example, the welding condition setting unit 12 calculates the build height of the Nth layer by referring to a database that defines the correspondence between build heights and welding speeds, as illustrated in FIG. 4 . The welding condition setting unit 12 sets the build height of the Nth layer as the vertical offset amount of the head. Next, the welding condition setting unit 12 determines whether the setting of the build conditions is complete (step S16). If the block of the Nth layer reaches the end of the object opposite the bottom side when the blocks from the first layer to the Nth layer are stacked along the shape of the object, the welding condition setting unit 12 determines that the setting of the welding conditions is complete; otherwise, the welding condition setting unit 12 determines that the setting of the welding conditions is incomplete. If the setting is complete (step S16; Yes), the processing of FIG. 7 is completed. The welding condition setting unit 12 records the set welding conditions for each layer (welding speed, torch angle, head position, etc.) in the storage unit 14. The control unit 13 reads out the welding conditions for each layer stored in the storage unit 14 and controls the welding system 1 to perform additive manufacturing using short-circuit transfer MIG welding. If it is determined that the process is incomplete (step S16; No), the welding condition setting unit 12 adds 1 to the variable N (step S17) and repeats the process from step S13.

[0024] (Effects) As described above, according to the method for setting welding conditions of this embodiment, it is possible to additively manufacture thin-walled structures and structures having shapes with varying inclinations or angles.

[0025] 8 is a diagram showing an example of the hardware configuration of the control device 10 according to the embodiment. The computer 900 includes a CPU 901, a main storage device 902, an auxiliary storage device 903, an input / output interface 904, and a communication interface 905. The above-described control device 10 is implemented in the computer 900. The above-described functions are stored in the auxiliary storage device 903 in the form of a program. The CPU 901 reads the program from the auxiliary storage device 903, loads it into the main storage device 902, and executes the above-described processing in accordance with the program. The CPU 901 allocates a storage area in the main storage device 902 in accordance with the program. The CPU 901 allocates a storage area in the auxiliary storage device 903 for storing data being processed in accordance with the program.

[0026] A program for implementing all or part of the functions of the control device 10 may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed to perform processing by each functional unit. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. If a WWW system is used, the term "computer system" also includes the homepage provision environment (or display environment). The term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, as well as storage devices such as hard disks built into the computer system. If the program is distributed to the computer 900 via a communication line, the computer 900 may load the program into the main storage device 902 and execute the processing described above. The program may be for implementing part of the functions described above, or may be capable of implementing the functions described above in combination with a program already stored in the computer system.

[0027] As described above, several embodiments according to the present disclosure have been described, but all of these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents as defined in the claims, as well as in the scope and spirit of the invention.

[0028] <Additional Notes> The welding condition setting device, welding condition setting method, and program described in the embodiments can be understood, for example, as follows.

[0029] (1) A welding condition setting device (control device 10) according to a first aspect is a welding condition setting device that sets welding conditions for additive manufacturing of an object by the WAAM method, and includes: means (welding condition setting unit 12) for calculating welding conditions corresponding to the build width of a target layer by referring to a database (line 41 in FIG. 4 ) that defines the correspondence between build widths and the welding conditions; means (welding condition setting unit 12) for calculating the build height of the target layer when built under the calculated welding conditions by referring to a database (line 42 in FIG. 4 ) that defines the correspondence between welding conditions and build heights; and means (welding condition setting unit 12) for setting the width of the target layer at a position corresponding to an edge of the object that would be created if the target layer were built at the calculated build height as the build width of the target layer to be built next. This makes it possible to set welding conditions for additive manufacturing of thin-walled structures and structures with shapes that vary in slope or angle.

[0030] (2) A welding condition setting device according to a second aspect is the welding condition setting device of (1), further including means (welding condition setting unit 12) for repeatedly executing the following process until the fabrication of the object is completed: the means for calculating welding conditions calculates welding conditions corresponding to the fabrication width of the fabrication target layer; the means for calculating the fabrication height calculates the fabrication height of the fabrication target layer; and the means for setting the fabrication width sets the fabrication width of the fabrication target layer to be fabricated next. This makes it possible to set welding conditions for each layer from the start to the completion of fabrication.

[0031] (3) A third aspect of the welding condition setting device is the welding condition setting device of (1) to (2), wherein the welding condition is any one of current, voltage, wire feed rate, and welding speed, thereby allowing the welding speed for each layer to be set.

[0032] (3') A welding condition setting device according to a third aspect is the welding condition setting device of (1) or (2), wherein the welding conditions are a welding speed when the current, voltage, and wire feed rate are constant. This enables additive manufacturing of thin-walled structures and structures with shapes that vary in slope or angle.

[0033] (4) A fourth aspect of the welding condition setting device is the welding condition setting device of any one of (1) to (3), further comprising means for calculating an inclination of the object to be formed in the layer to be formed, and calculating an angle at which the torch can be tilted at the same angle as the inclination as the inclination, as the torch angle of the layer to be formed. This enables additive manufacturing of a structure having a shape with variable inclination or angle.

[0034] (5) A fifth aspect of the welding condition setting device is the welding condition setting device of any one of (1) to (4), further comprising means for calculating a center position in the width direction of the object to be formed in the forming target layer and calculating an offset amount for moving a torch to the center position, thereby enabling additive manufacturing of a tapered structure.

[0035] (6) A sixth aspect of the present invention relates to a welding condition setting device according to any one of (1) to (5), wherein the WAAM-based additive manufacturing uses short-circuit transfer MIG welding, and the means for calculating the welding conditions calculates the welding conditions based on short-circuit transfer MIG welding. By using short-circuit transfer MIG welding while setting the welding conditions according to the present disclosure, it is possible to additively manufacture thin-walled structures and structures with shapes that vary in slope or angle.

[0036] (7) A seventh aspect of the present invention provides a welding condition setting device according to any one of (1) to (6), wherein the width of the object to be formed is a width that can be formed in one welding pass. By setting the welding conditions according to the present disclosure, a structure can be formed with high precision in one pass.

[0037] (8) A welding condition setting method according to the eighth aspect is a welding condition setting method executed by a computer for setting welding conditions when additively manufacturing an object to be manufactured using the WAAM method, and includes the steps of: calculating welding conditions corresponding to the manufacturing width of the layer to be manufactured by referring to a database that defines the correspondence between the manufacturing width and the welding conditions; calculating the manufacturing height of the layer to be manufactured when manufactured using the calculated welding conditions by referring to a database that defines the correspondence between the welding conditions and the manufacturing height; and setting the width of the object to be manufactured at a position corresponding to the edge of the object to be manufactured when the layer to be manufactured is manufactured at the calculated manufacturing height as the manufacturing width of the layer to be manufactured next.

[0038] (9) A program according to a ninth aspect causes a computer to execute a process for setting welding conditions when additively manufacturing an object to be manufactured using the WAAM method, the process comprising the steps of: calculating welding conditions corresponding to the manufacturing width of the layer to be manufactured by referring to a database that defines the correspondence between the manufacturing width and the welding conditions; calculating the manufacturing height of the layer to be manufactured using the calculated welding conditions by referring to a database that defines the correspondence between the welding conditions and the manufacturing height; and setting the width of the object to be manufactured at a position corresponding to the edge of the object that will be created when the layer to be manufactured is manufactured at the calculated manufacturing height as the manufacturing width of the layer to be manufactured next.

[0039] The above-described welding condition setting device, welding condition setting method, and program enable additive manufacturing of thin-walled structures and structures having shapes with varying inclinations or angles.

[0040] REFERENCE SIGNS LIST 1 Welding system 2 Welding robot 3 Welding machine 4 Wire feeder 5 Torch 6 Modeled object 7 Positioning device 10 Control device 11 Shape data acquisition unit 12 Welding condition setting unit 13 Control unit 14 Memory unit 100 Additive manufacturing system 900 Computer 901 CPU 902 Main memory device 903 Auxiliary memory device 904 Input / output interface 905 Communication interface

Claims

1. A welding condition setting device that sets welding conditions when additive manufacturing an object using the WAAM method, comprising: means for calculating welding conditions corresponding to the build width of a layer to be built by referring to a database that defines the correspondence between build widths and the welding conditions; means for calculating the build height of the layer to be built when built under the calculated welding conditions by referring to a database that defines the correspondence between welding conditions and build heights; and means for setting the width of the object to be built at a position corresponding to the edge of an object that would be created when the layer to be built is built at the calculated build height, as the build width of the layer to be built next.

2. The welding condition setting device according to claim 1, further comprising: means for repeatedly executing the process of calculating the welding conditions corresponding to the build width of the layer to be built by the means for calculating the welding conditions, calculating the build height of the layer to be built by the means for calculating the build height, and setting the build width of the layer to be built next by the means for setting the build width, until the building of the object to be built is completed.

3. The welding condition setting device according to claim 1 or 2, wherein the welding condition is one of current, voltage, wire feed rate, and welding speed.

4. A welding condition setting device as described in claim 1 or claim 2, further comprising: means for calculating the inclination of the object to be formed in the layer to be formed, and calculating the angle at which the torch can be tilted at the same angle as the inclination as the torch angle for the layer to be formed.

5. The welding condition setting device according to claim 1 or claim 2, further comprising means for calculating the center position in the width direction of the object to be formed in the layer to be formed, and calculating an offset amount for moving the torch to said center position.

6. The welding condition setting device according to claim 1 or claim 2, wherein the WAAM-type additive manufacturing uses short-circuit transfer MIG welding, and the means for calculating the welding conditions calculates welding conditions based on short-circuit transfer MIG welding.

7. The welding condition setting device according to claim 1 or 2, wherein the width of the object to be formed is a width that can be formed in one welding operation.

8. A welding condition setting method executed by a computer for setting welding conditions when additive manufacturing an object using the WAAM method, comprising the steps of: calculating welding conditions corresponding to the build width of a layer to be built by referring to a database that defines the correspondence between build widths and the welding conditions; calculating the build height of the layer to be built when built under the calculated welding conditions by referring to a database that defines the correspondence between welding conditions and build heights; and setting the width of the object to be built at a position corresponding to the edge of an object that would be created when the layer to be built is built at the calculated build height as the build width of the layer to be built next.

9. A program that causes a computer to execute a process for setting welding conditions when additively manufacturing an object using the WAAM method, comprising the steps of: calculating welding conditions corresponding to the width of the layer to be manufactured by referring to a database that defines the correspondence between the manufacturing width and the welding conditions; calculating the manufacturing height of the layer to be manufactured by referring to a database that defines the correspondence between the welding conditions and the manufacturing height, when the layer to be manufactured is manufactured under the calculated welding conditions; and setting the width of the object to be manufactured at a position corresponding to the edge of the object that will be manufactured when the layer to be manufactured is manufactured at the calculated manufacturing height, as the manufacturing width of the layer to be manufactured next.

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