Method and apparatus for manufacturing a shaped article

Abstract

To provide a manufacturing method and a manufacturing apparatus of a molded object that can manufacture a molded object into a target shape even for shapes in which it is difficult to manage the lamination height of a weld beads.SOLUTION: A manufacturing method of a molded object includes: an information acquisition process which acquires lamination planning information and target shape information of a molded object 14; an integration index calculation process which calculates an integration index of the lamination shape in which multiple weld beads B are stacked from the welding conditions, bead shape, and lamination trajectory; a welding condition adjustment process which adjusts the welding condition on the basis of the integration index and the target shape information; and a lamination molding process which repeatedly laminates the weld beads B under the acquired welding condition. The welding condition adjustment process corrects at least the welding amount and lamination position included in the welding condition so that the bead width perpendicular to the lamination trajectory approximates the same value in each layer, and the deviation between the integration index and the target shape is reduced.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for manufacturing a shaped object.

Background Art

[0002] In recent years, the need for 3D printers as a production means has been increasing, and in particular, research and development has been carried out for practical application in the aircraft industry and the like regarding the application to metal materials. A 3D printer using a metal material melts metal powder or a metal wire using a heat source such as a laser or an arc, and laminates the molten metal to form a shaped object.

[0003] Patent Document 1 discloses a shaping method in which a welding bead is formed while moving a formed body or a shaped object and a filler metal torch so that the welding surface is always at a predetermined angle and the filler metal torch and the welding surface maintain a predetermined distance by NC control.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the laminated shaping for manufacturing a shaped object by laminating welding beads, in order to manage the lamination state of the welding beads, it is generally performed to monitor the height of the laminated welding beads and adjust the lamination conditions according to the bead height.

[0006] However, when welding beads are laminated in an overhanging shape, if the lamination conditions are adjusted focusing only on the height, sag may occur in the welding beads, and the shape of the shaped object may deviate from the target shape.

[0007] In particular, when the weld beads are stacked in an arch shape, the overhang angle of the weld beads differs for each pass. Therefore, once misalignment occurs, it is likely to expand thereafter. Similarly, even when the weld beads are stacked on a smooth curved surface, the shape of the formed object is likely to deviate from the target shape due to the difference in the tendency of the weld beads to sag depending on the inclination of the curved surface.

[0008] Therefore, an object of the present invention is to provide a method and an apparatus for manufacturing a formed object capable of forming a formed object into a target shape even in a shape where it is difficult to control the stacking height of weld beads.

Means for Solving the Problems

[0009] The present invention has the following configuration. (1) A method for manufacturing a formed object that melts a welding material to form a weld bead and forms a formed object in which the weld beads are stacked, comprising: an information acquisition step of acquiring lamination plan information including welding conditions, bead shape, and lamination trajectory of the weld beads to be laminated and target shape information of the formed object to be formed; an integrated index calculation step of calculating an integrated index of the lamination shape in which a plurality of the weld beads are laminated from the welding conditions, the bead shape, and the lamination trajectory; a welding condition adjustment step of adjusting the welding conditions based on the integrated index and the target shape information; a lamination forming step of repeatedly laminating the weld beads under the acquired welding conditions; and in the welding condition adjustment step, at least the welding amount and the lamination position included in the welding conditions are corrected so that the bead width in the direction perpendicular to the lamination trajectory approaches the same value in each layer and the deviation between the integrated index and the target shape is reduced. A method for manufacturing a formed object. (2) A manufacturing apparatus for a formed object that melts a welding material to form a weld bead and forms a formed object in which the weld beads are stacked, comprising: an information acquisition unit that acquires lamination plan information including welding conditions, bead shape, and lamination trajectory of the weld beads to be laminated and target shape information of the formed object to be formed; An integrated index calculation unit that calculates an integrated index of a stacked shape in which a plurality of the weld beads are stacked from the welding conditions, the bead shape, and the stacking path; A welding condition adjustment unit that adjusts the welding conditions based on the integrated index and the target shape information; A layered modeling unit that repeatedly stacks the weld beads under the obtained welding conditions; It has, The welding condition adjustment unit corrects at least the welding amount and the stacking position included in the welding conditions so that the bead width in the direction perpendicular to the stacking path approaches the same value in each layer and the deviation between the integrated index and the target shape is reduced. A manufacturing apparatus for a shaped object.

Effect of the Invention

[0010] According to the present invention, even in a shape where it is difficult to manage the stacking height of the weld beads, the shaped object can be shaped into the target shape.

Brief Description of the Drawings

[0011]

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MODE FOR CARRYING OUT THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The additive manufacturing system shown here melts a filler material (welding wire) held by a manipulator with a heat source device to form a welding bead, and repeatedly stacks the formed welding beads into a desired shape to form a shaped object formed by stacking the welding beads.

[0013] <Configuration of the Additive Manufacturing System> An example of a configuration of an additive manufacturing system that operates based on the trajectory plan determined by the above-described trajectory plan support device will be described. FIG. 1 is a schematic diagram showing the overall configuration of the additive manufacturing system. The additive manufacturing system 100 includes a shaping control device 15, a manipulator 17, a filler material supply device 19, a manipulator control device 21, and a heat source control device 23.

[0014] The manipulator control device 21 controls the manipulator 17 and the heat source control device 23. A controller (not shown) is connected to the manipulator control device 21, and any operation of the manipulator control device 21 can be instructed from an operator via the controller.

[0015] The manipulator 17 is, for example, an articulated robot, and the filler material M is supported so as to be continuously supplied to a torch 11 provided on the tip axis. The torch 11 holds the filler material M in a state of protruding from the tip. The position and orientation of the torch 11 can be arbitrarily set three-dimensionally within the range of the degrees of freedom of the robot arm constituting the manipulator 17. The manipulator 17 preferably has six or more degrees of freedom, and preferably can arbitrarily change the axial direction of the heat source at the tip. The manipulator 17 may have various forms, such as an articulated robot with four or more axes shown in FIG. 1, or a robot equipped with an angle adjustment mechanism on two or more orthogonal axes.

[0016] The torch 11 has a shield nozzle (not shown), and shield gas is supplied from the shield nozzle. The shield gas blocks the atmosphere, prevents oxidation, nitridation, etc. of the molten metal during welding, and suppresses welding defects. As the arc welding method used in this configuration, it may be either a consumable electrode type such as covered arc welding or carbon dioxide arc welding, or a non-consumable electrode type such as TIG (Tungsten Inert Gas) welding or plasma arc welding, and is appropriately selected according to the shaping object. Here, gas metal arc welding will be described as an example. In the case of the consumable electrode type, a contact tip is arranged inside the shield nozzle, and the filler metal M to which current is supplied is held by the contact tip. The torch 11 generates an arc from the tip of the filler metal M in a shield gas atmosphere while holding the filler metal M.

[0017] The filler metal supply device 19 supplies the filler metal M toward the torch 11. The filler metal supply device 19 includes a reel 19a around which the filler metal M is wound and a feeding mechanism 19b that feeds out the filler metal M from the reel 19a. The filler metal M is fed to the torch 11 while being sent in the forward or reverse direction as needed by the feeding mechanism 19b. The feeding mechanism 19b is not limited to a push type arranged on the filler metal supply device 19 side to extrude the filler metal M, and may be a pull type arranged on a robot arm or the like, or a push-pull type.

[0018] The heat source control device 23 is a welding power source that supplies the electric power required for welding by the manipulator 17. The heat source control device 23 adjusts the welding current and welding voltage supplied during bead formation for melting and solidifying the filler metal M. Further, in conjunction with welding conditions such as the welding current and welding voltage set by the heat source control device 23, the filler metal supply speed of the filler metal supply device 19 is adjusted.

[0019] The heat source for melting the filler material M is not limited to the above-described arc. For example, other heat source methods such as a heating method using a combination of an arc and a laser, a heating method using plasma, a heating method using an electron beam or a laser may be employed. When heating with an electron beam or a laser, the heating amount can be more finely controlled, the state of the formed bead can be maintained more appropriately, and it can contribute to further improving the quality of the laminated structure. Also, the material of the filler material M is not particularly limited, and for example, the type of filler material M used may differ according to the characteristics of the shaped object 14, such as mild steel, high-tensile steel, aluminum, aluminum alloy, nickel, nickel-based alloy, etc.

[0020] The shaping control device 15 controls the above-described respective parts in an overall manner.

[0021] The laminated shaping system 100 having the above-described configuration operates according to a shaping program created based on the shaping plan of the shaped object 14. The shaping program is composed of a number of instruction codes and is created based on an appropriate algorithm according to various conditions such as the shape, material, and heat input amount of the shaped object. According to this shaping program, while moving the torch 11, the supplied filler material M is melted and solidified, and a linear welding bead B, which is a melt-solid of the filler material M, is formed on the base plate 13. That is, the manipulator control device 21 drives the manipulator 17 and the heat source control device 23 based on a predetermined program provided from the shaping control device 15. The manipulator 17 moves the torch 11 while melting the filler material M with an arc according to a command from the manipulator control device 21 to form the welding bead B. By sequentially forming and laminating the welding beads B in this way, the shaped object 14 having the desired shape is obtained.

[0022] FIG. 2 is a functional block diagram of the shaping control device 15. The shaping control device 15 includes an information acquisition unit 31, a welding condition specifying unit 33, an integration index calculation unit 35, and a welding condition adjustment unit 37.

[0023] The above-described shaping control device 15 is configured by hardware using an information processing device such as a PC (Personal Computer). Each function of the shaping control device 15 is realized by a control unit (not shown) reading out a program having a specific function stored in a storage device (not shown) and executing the program. Examples of the storage device include memories such as a RAM (Random Access Memory) which is a volatile storage area, a ROM (Read Only Memory) which is a non-volatile storage area, and storage devices such as an HDD (Hard Disk Drive) and an SSD (Solid State Drive). Examples of the control unit include a processor such as a CPU (Central Processing Unit) and an MPU (Micro Processor Unit), or a dedicated circuit. In addition to the above-described form, the shaping control device 15 may be another computer remotely connected from the additive manufacturing system 100 via a network or the like.

[0024] In the above-described shaping control device 15, when shaping the shaped object 14 by laminating the welding beads B, an information acquisition step, an integration index calculation step, a welding condition adjustment step, and an additive manufacturing step are performed.

[0025] <Example of the shaping procedure of the shaped object> Next, an example of the shaping procedure of the shaped object 14 by the shaping control device 15 will be described. FIG. 3 is a flowchart showing the shaping procedure of the shaped object by the shaping control device 15. FIG. 4 is a schematic diagram showing a model of the arch-shaped shaped object 14. As shown in FIG. 4, here, the case of shaping the arch-shaped shaped object 14 by laminating the welding beads B will be described as an example.

[0026] (Information acquisition step) The information acquisition unit 31 acquires lamination plan information including the welding conditions, bead shape, and lamination trajectory of the welding beads B to be laminated, and the target shape information of the shaped object 14 to be shaped (step S1).

[0027] FIGS. 5A to 5E are explanatory diagrams showing examples of the lamination plan information. As shown in Fig. 5A, welding conditions for the stacked welding beads B include the moving speed Vt when moving the torch 11 to form the welding bead B and the feeding speed Vw of the filler material M. As shown in Fig. 5B, bead shapes include the bead height h v of the welding bead B, the bead width w H , the weld deposit amount Sw, etc. As shown in Fig. 5C, stacking trajectories include the bead stacking position r (r = (x, y, z)) from the stacking start point Ps(i) to the stacking end point Pe(i) where beads are stacked on a specific path (k-th layer), and as shown in Fig. 5D, the movement amount Δr (Δr = (Δx, Δy, Δz)) between the stacking start point Ps(i) and stacking end point Pe(i) and the stacking start point Ps(j) and stacking end point Pe(j) between paths (between the k-th layer and the k + 1-th layer), and there are stacking trajectories C where a plurality of welding beads B are stacked. As shown in Fig. 5E, target shapes of the shaped object 14 include the shaped object width W which is the width dimension of the shaped object 14 to be shaped and the shaped object height H which is the height dimension, etc.

[0028] (Integrated index calculation step) The integrated index calculation unit 35 calculates an integrated index of the stacking shape in which a plurality of welding beads B are stacked from the welding conditions, bead shapes, and stacking trajectories (step S2).

[0029] In this integrated index calculation step, indices reflecting the progress of the stacking shape such as height and width are calculated. Fig. 7 is a schematic diagram showing the integrated index in the shaped object 14. As shown in Fig. 7, the integrated index includes the integrated height Ha, the integrated width Wa, the bead width wi of the upper surface of the welding bead B perpendicular to the stacking direction at the upper end of the shaped object 14 ⊥c , the integrated value Aa of the stacking position, etc., and in the integrated index calculation step, only some of these indices may be calculated. These integrated height Ha, integrated width Wa, bead width wi of the upper surface ⊥c , and the integrated value Aa of the stacking position are calculated by formulas (1) to (4) respectively.

[0030] [Number]

[0031] Note that for the bead width wi on the upper surface ⊥c Regarding this, when sagging occurs in the weld bead B, the bead width becomes thinner accordingly, so the cumulative effect of the sagging is expressed on the right side of Equation (3). Also, the integrated value Aa of the stacking position indicates where on the stacking path C it is located, which may be in coordinates or may be calculated as the path length on the stacking path C. Here, in Equations (1) to (3), subscripts are provided for distinction to specify in which direction the height and width are defined. In the subscripts, V means vertical, H means horizontal, and ⊥c means perpendicular to the stacking path C. Note that the bead width wi on the upper surface of the bead ⊥c Not limited to this, the same can be said for the bead width wiu on the lower surface of the bead ⊥c (see Fig. 7), so the integrated index may be calculated using the bead width wiu on the lower surface of the bead ⊥c However, the bead width wiu on the lower surface of the bead ⊥c is evaluated from the laminate after the upper and lower weld beads B are fused together, while the bead width wi on the upper surface of the bead ⊥c can be directly measured before being fused with the upper weld bead B. Therefore, when sequentially correcting the welding conditions during shaping, it is more preferable to evaluate Equation (7) using the bead width wi on the upper surface of the bead ⊥c . For example, the bead width wiu on the lower surface of the bead ⊥c becomes difficult to measure with a laser sensor when the inclination in the stacking direction becomes steep, but the bead width wi on the upper surface of the bead ⊥c can be measured with a laser sensor in addition to a camera.

[0032] (Welding condition adjustment process) The welding condition adjustment unit 37 adjusts the welding conditions based on the integrated index and the target shape information. And in the above welding condition adjustment process, the welding condition adjustment unit 37 corrects at least the welding amount and the stacking position included in the welding conditions so that the bead width in the direction perpendicular to the stacking path C approaches the same value in each layer and reduces the deviation between the integrated index and the target shape (step S3).

[0033] Here, Equations (5) to (7) are equations for adjusting welding conditions, and from these Equations (5) to (7), the adjusted index (solution to be obtained) of Equation (8) is derived. Note that Equation (8), which is the adjusted index, is distinguished by adding a hat symbol.

[0034]

Number

[0035] Equation (5) is an equation considering height adjustment, and Equation (6) is an equation considering width adjustment. In these Equations (5) and (6), when the weld beads B are stacked obliquely like an overhang, the height and width do not simply accumulate as in the case of vertical stacking. Therefore, R1 and R2 represent the influence of the inclination. Most simply, it can be expressed by cosα, sinα, etc. with respect to the inclination α from the horizontal. On the other hand, the terms in {} on the right side of Equations (5) and (6) represent the deviation between the integrated index and the target shape. According to this deviation, the denominator n can be changed or the welding position r can be changed.

[0036] Equation (7) is an equation that imposes a condition that the bead width of any layer can be regarded as substantially constant. Of course, when the weld beads B are stacked obliquely like an overhang, the width tends to become thinner due to dripping to the side by the amount of inclination, and the influence is represented by the second term in the middle. Also, the first term in the middle of Equation (7) represents the increase or decrease of the bead width due to the welding amount. For example, for the function θ, a regression equation can be created from experiments examining the correlation between the inclination direction, the welding amount, and the dripping. Also, the function Λ can be obtained experimentally in the same way as the function θ. Also, predetermined allowable variations are set for the bead width that becomes a predetermined constant on the right side and the left side of Equation (7).

[0037] Figure 7 is a diagram for explaining the influence of correcting the stacking position of the weld beads B. In Figure 7, Pa represents the bead stacking position before correction, and Pb represents the bead stacking position after correction. Figure 7 shows that by correcting the bead stacking position of the i-th layer, the increase amounts of the height and width change.

[0038] (Laminated manufacturing process) Thereafter, welding beads B are repeatedly laminated under the adjusted welding conditions to form the shaped object 14 (step S4).

[0039] FIG. 8 is a diagram for explaining the comparison of the laminated states before and after adjustment of the welding conditions. The left side of FIG. 8 shows a state where welding beads B are formed at the target position Pa without considering the influence of the sag of the welding beads B and stacked along the stacking direction as units. In this state, the upper surface width of the bead in the lower layer and the lower surface width of the bead in the upper layer do not match, and sag actually occurs. The center of FIG. 8 shows a state where the welding beads B are formed at the target position Pb considering the influence of the sag of the welding beads B, and the welding amount and the stacking position are corrected so that the upper surface widths of the beads in each layer approach the same value. In this example, since the upper layer is more likely to sag, the welding amount decreases as the upper layer increases and increases as the lower layer increases. The right side of FIG. 8 shows a superposed illustration of the stacking position when the influence of the sag of the welding beads B is not considered (left side of FIG. 8) and the stacking position when the influence of the sag of the welding beads B is considered (center of FIG. 8), and the stacking position is corrected so that the final stacked shape matches the target shape. Thus, according to the manufacturing method according to this configuration example, for example, it is possible to shape a shaped object such as a shape whose laminated shape is difficult to manage due to having an overhang into the target shape.

[0040] <Application example of the shaping procedure of the shaped object> Next, an application example of the shaping procedure of the shaped object 14 by the shaping control device 15 will be described. FIG. 9 is a flowchart showing the shaping procedure of the shaped object by the shaping control device 15. FIG. 10 is a schematic diagram showing a model of the arch-shaped shaped object 14. FIG. 11 is a schematic diagram showing the bead model BM of the welding beads B with different bead widths BW. FIG. 12 is a schematic diagram of the shaped object 14 shaped based on the bead model BM of the welding beads B with different bead widths BW. FIG. 13 is a schematic diagram showing a model of the arch-shaped shaped object 14 after adjustment of the welding conditions.

[0041] The information acquisition unit 31 acquires lamination plan information including a reference width Bw as the bead shape of the welding bead B to be laminated and target shape information of the object 14 to be formed (step S11).

[0042] For example, as shown in FIG. 10, when forming an arch-shaped object 14, trapezoidal bead models BM of the same shape divided equally with respect to the object 14 are assigned and arranged. Then, by adjusting the size of this bead model BM, a bead model BM that satisfies the target shape (the solid black line in FIG. 10) to be formed is created, and a reference width BWb that becomes the reference bead width BW of this bead model BM is acquired. This reference width BWb is the dimension of the bead model BM in a direction orthogonal to the lamination direction DL of the welding bead B.

[0043] Note that as a method of assigning the welding bead B to the object 14, for example, the shape of the three-dimensional shape data (CAD data or the like) of the read object 14 is sliced in a direction orthogonal to the lamination direction DL of the welding bead B, and further, it is divided into rectangular bead models BM so as to correspond to the bead shape of the welding bead B. Then, the plurality of divided rectangular bead models BM are fitted to a trapezoid which is a simple geometric figure and changed to a trapezoidal bead model BM.

[0044] The welding condition specifying unit 33 specifies the welding conditions when forming the welding bead B with a welding amount that satisfies the reference width BWb (step S12). The welding amount of each welding bead B is adjusted according to the lamination direction DL and the number of laminations of the welding bead B. When adjusting, it is restricted so that the bead width BW of each welding bead B satisfies the reference width BWb. Note that this specification of the welding conditions may be directly acquired from the lamination plan.

[0045] Here, as shown in FIGS. 11 and 12, when the weld beads B1 and B2 are alternately stacked based on the bead models BM1 and BM2 with different bead widths BW1 and BW2, the weld bead B2 with a bead width BW2 wider than the weld bead B1 is likely to have sagging at the protruding portions at both ends. In this way, when the weld beads B1 and B2 are stacked using the bead models BM1 and BM2 with different bead widths BW1 and BW2, not only may the stacking height not be achieved, but the overall shape may deviate significantly from the target shape. Such a phenomenon is likely to occur, for example, when the weld bead B is stacked on the base plate 13 having an inclined surface. When the base plate 13 is an inclined surface, the bead width BW of the upward weld bead B formed on the upper side in the inclined direction becomes narrow, and the bead width BW of the downward weld bead B formed on the lower side in the inclined direction becomes wide. That is, the deviation of the shape of the shaped object 14 from the target shape is likely to occur when the upward weld bead B and the downward weld bead B are alternately stacked.

[0046] Therefore, the welding condition specifying unit 33 creates a bead model BM in which the welding amount of the weld bead B is adjusted while adjusting the bead width BW of each weld bead B to the reference width BWb. Ideally, the bead width BW of the bead model BM of each weld bead B is desirably a constant value, but the welding amount may be adjusted so that the bead width BW falls within ±α with respect to the reference width BWb by setting a minute allowable value α.

[0047] In addition, when the bead width BW of the weld bead B of the bead model BM is preferentially adjusted to the reference width BWb, the welding amount and the bead height may differ in each weld bead B. The welding condition specifying unit 33 calculates the welding conditions of each weld bead B while allowing for such differences in the welding amount and the bead height in each weld bead B.

[0048] The specific calculation method of the welding conditions is not particularly limited. For example, a modeled equation may be prepared based on representative parameters of the welding conditions, and the conditions may be adjusted using the equation.

[0049] For example, the bead height BH may be obtained from Equation (9), and the bead width BW may be obtained from Equation (10). BH = C1 + C2Wf + C3Ts + C4Wf2 + C5Ts2 + C6WfTs ··· Equation (9) BW = D1 + D2Wf + D3Ts + D4Wf2 + D5Ts2 + D6WfTs ··· Equation (10) Ts: Torch movement speed Wf: Filler metal feeding speed C1~C6: Coefficients D1~D6: Coefficients

[0050] The integrated index calculation unit 35 calculates the integrated height Ha of the height of the welded bead B to be stacked as an integrated index from the welding conditions, the reference width BWb which is the bead shape, and the stacking trajectory (step S13). That is, the height dimension in the vertical direction of the shaped object 14 for stacking the welded bead B is defined as the integrated height Ha. Note that the integrated height Ha may be calculated as the line segment length of the curve along the stacking direction DL of the welded bead B.

[0051] The welding condition adjustment unit 37 adjusts the welding conditions based on the integrated height Ha which is the integrated index and the target shape information (step S14). Specifically, the integrated height Ha calculated by the integrated index calculation unit 35 is compared with the target height Ht based on the target shape information. Then, it is determined whether the deviation between these integrated height Ha and target height Ht (|Ha - Ht|) is within a predetermined allowable variation value ε.

[0052] When the welding condition adjustment unit 37 determines that the deviation between the integrated height Ha and the target height Ht exceeds the allowable variation value ε (step S14: No), the welding conditions specified by the welding condition specifying unit 33 are adjusted to the welding conditions with the number of passes or the welding amount of the welded bead B changed (step S15). In this adjustment of the welding conditions, for example, at least one of the change in the number of passes of the welded bead B for shaping the shaped object 14 and the distribution of the bead height BH of each welded bead B is adjusted.

[0053] For example, when forming an arch-shaped object 14 (see Fig. 10), as shown in Fig. 13, the deposition amount of the welding bead B is increased as the lamination direction DL approaches perpendicular, and the deposition amount of the welding bead B is decreased as the inclination becomes larger. Note that the welding conditions and the number of passes of each welding bead B may be adjusted based on the bead width BW and the aspect ratio of the portion that can be realized by one welding bead B. For example, at a location where the welding bead B is likely to sag, the number of passes may be increased to reduce the deposition amount per welding bead B, and the welding conditions may be adjusted so that the aspect ratio becomes smaller.

[0054] These welding conditions can be adjusted relatively easily, for example, by any one or a combination of the angle of the torch 11 for forming the welding bead B, the welding speed of the welding bead B, the feeding speed of the filler material M fed to the torch 11, the welding current of the welding bead B, the welding voltage of the welding bead B, the torch running direction of the torch 11, and the weaving conditions of the torch 11.

[0055] When the welding condition adjustment unit 37 determines that the deviation between the integrated height Ha and the target height Ht is within the allowable variation value ε or less (step S14: YES), the welding conditions specified or adjusted by the welding condition specifying unit 33 are maintained, and then the welding bead B is repeatedly laminated under these welding conditions to form the object 14 (step S16).

[0056] As described above, according to the manufacturing method of the object 14 of this configuration example, by laminating the welding beads B with priority given to the uniformity of the bead width BW, it is possible to suppress the sagging of the welding bead B when laminating the welding beads B, and the lamination height of the object 14 can be easily adjusted.

[0057] In addition, when matching the bead width BW, the deposition amount and the bead height BH of each welding bead B are not fixed, so the welding conditions can be flexibly adjusted according to the lamination location and the lamination posture. In particular, it is possible to perform good lamination on the overhang portion and on the inclined surface.

[0058] Next, an application example of the object manufacturing method by the above-described shaping control device 15 will be described. FIG. 14 is a schematic diagram for explaining the shaping of the shaped object 14 on the inclined surface Si. FIG. 15 is a schematic diagram showing the cross-sectional shape of the weld bead B when the weld bead B is formed along the inclination direction of the inclined surface Si. FIG. 16 is a schematic diagram showing the shaped object when weld beads B with different cross-sectional shapes are laminated. FIG. 17 is a schematic diagram showing the shaped object 14 when the welding conditions are adjusted.

[0059] As shown in FIG. 14, in this application example, the base plate 13 is an inclined surface Si inclined at an inclination angle θa with respect to the horizontal plane, and the shaped object 14 is shaped by laminating the weld bead B on this inclined surface Si. The weld bead B is formed in the upward inclination direction Du and the downward inclination direction Dd with respect to the inclined surface Si. That is, with respect to the inclined surface Si, the upward advancing weld bead Bu formed toward the upward inclination direction Du and the downward advancing weld bead Bd formed toward the downward inclination direction Dd are alternately laminated. In this way, if the upward advancing weld bead Bu and the downward advancing weld bead Bd are alternately laminated with respect to the inclined surface Si, the torch 11 can be turned back between each pass, so that the movement amount of the torch 11 can be suppressed and the productivity can be improved.

[0060] However, as shown in FIG. 15, when the weld bead B is formed along the inclination direction on the inclined surface Si, the upward advancing weld bead Bu and the downward advancing weld bead Bd are formed with different aspect ratios in cross section compared to the normal weld bead Bf formed on the horizontal plane.

[0061] For this reason, as shown in FIG. 16, compared with the case where the weld bead Bf is laminated on the horizontal plane (the left side in FIG. 16), when the upward advancing weld bead Bu and the downward advancing weld bead Bd are alternately laminated on the inclined surface Si (the right side in FIG. 16), there will be a deviation in shape and shaping height.

[0062] In such a case, the welding conditions of each of the upward welding bead Bu and the downward welding bead Bd are adjusted (steps S12 to S15) so that the bead widths BW of the upward welding bead Bu and the downward welding bead Bd satisfy the reference width BWb obtained from the reference bead model. For example, by adjusting the welding speed, the amount of deposition when forming the upward welding bead Bu is increased, and the amount of deposition when forming the downward welding bead Bd is decreased. Then, as shown in FIG. 17, even when the welding beads Bu and Bd are alternately stacked on the inclined surface Si (the right side in FIG. 17) as compared with the case where the welding bead Bf is stacked on the horizontal plane (the left side in FIG. 17), the welding beads Bu and Bd can be stacked in a well-balanced manner, and the shape and the profiling height can be approximated.

[0063] Next, a modified example will be described. Note that the same components as those in the above configuration example are denoted by the same reference numerals, and the description thereof will be omitted. FIG. 18 is a flowchart showing a modified example of the profiling procedure by the profiling control device 15.

[0064] As shown in FIG. 18, in the modified example, when the welding bead B is formed and stacked (step S16), the shape of the workpiece 14 during profiling is measured by a shape measurement sensor, and a shape profile is obtained (step S17). Note that the shape measurement sensor may be arranged in parallel with the torch 11 at the tip axis of the manipulator 17, or may be installed separately from the manipulator 17.

[0065] Then, based on the obtained shape profile, the bead width BW and the stacking height of the stacked welding beads B are extracted. Further, with reference to the information on the bead width BW and the stacking height, the reference width BWb and the integrated height Ha are monitored during the shaping process, and the welding conditions are adjusted as necessary. For example, the welding conditions may be corrected in real time so that the bead width BW does not fall below the reference width BWb. Also, after correcting the reference width BWb with the bead width BW obtained by shape measurement, the integrated height Ha is compared with the target height Ht, and the welding conditions such as the feeding speed of the filler metal M, the welding speed of the welding bead B, and the presence or absence of weaving may be adjusted again during the shaping process.

[0066] According to this modification, since the integrated height Ha is corrected from the shape profile obtained by shape measurement based on the shape of the shaped object 14 during the shaping process, the integrated height Ha and the target shape can be compared more accurately, and as a result, the welding conditions can be adjusted with high accuracy.

[0067] As described above, the present invention is not limited to the above-described embodiments, and it is also contemplated by the present invention that those skilled in the art may make changes and applications based on the combination of the respective configurations of the embodiments, the description of the specification, and well-known techniques, and such changes and applications are included in the scope for which protection is sought.

[0068] As described above, the following matters are disclosed in this specification. (1) A method for manufacturing a shaped object that forms a welding bead by melting a welding material and shapes a shaped object in which the welding beads are stacked, comprising: an information acquisition step of acquiring lamination plan information including welding conditions, bead shapes, and lamination trajectories of the welding beads to be laminated and target shape information of the shaped object to be shaped; an integrated index calculation step of calculating an integrated index of a lamination shape in which a plurality of the welding beads are laminated from the welding conditions, the bead shapes, and the lamination trajectories; a welding condition adjustment step of adjusting the welding conditions based on the integrated index and the target shape information; a lamination shaping step of repeatedly laminating the welding beads under the obtained welding conditions; and The welding condition adjustment step is a method for manufacturing a shaped article that at least corrects the deposition amount and the lamination position included in the welding conditions so that the bead width in the direction perpendicular to the lamination path approaches the same value in each layer and reduces the deviation between the integrated index and the target shape. According to this method for manufacturing a shaped article, by laminating welding beads with priority given to the uniformity of the bead width, it is possible to suppress the sagging of the welding beads when laminating the welding beads, and it is possible to easily adjust the lamination height of the shaped article. In addition, when matching the bead widths, the deposition amount and bead height of each welding bead are not fixed, so the welding conditions can be flexibly adjusted according to the lamination location and lamination posture. In particular, it is possible to perform shaping of the overhang portion and good lamination on an inclined surface.

[0069] (2) The welding condition adjustment step involves adjusting any one or a combination of the angle of the torch forming the welding bead, the welding speed of the welding bead, the feeding speed of the filler material fed to the torch, the welding current of the welding bead, the welding voltage of the welding bead, the torch weaving direction, and the torch weaving conditions, and is the method for manufacturing a shaped article according to (1). According to this method for manufacturing a shaped article, it is possible to adjust the deposition amount, bead width, and aspect ratio of the welding bead relatively simply.

[0070] (3) The welding condition adjustment step corrects the number of layers and corrects the deposition amount so as to decrease the deposition amount and increase the number of layers, and is the method for manufacturing a shaped article according to (1) or (2). According to this method for manufacturing a shaped article, by increasing the number of layers, it is possible to finely adjust the height and width of the laminated shape, and it is easy to make the laminated shape approach the target shape.

[0071] (4) The method for manufacturing a shaped article further includes a shape profile acquisition step of measuring the shape of the laminated welding bead to obtain a shape profile, and correcting the integrated index based on the obtained shape profile, and is the method for manufacturing a shaped article according to any one of (1) to (3). According to the manufacturing method of this shaped object, since the integrated index is corrected based on the shape profile obtained by shape measurement, the integrated index and the target shape can be compared more accurately. As a result, the welding conditions can be adjusted with higher precision. Also, during the lamination of the welding beads, the welding conditions can be adjusted and corrected based on the shape of the shaped object during shaping.

[0072] (5) The manufacturing method of the shaped object according to any one of (1) to (4), wherein in the welding condition adjustment step, the welding amount is adjusted so that the larger the inclination angle of the lamination direction of the welding bead with respect to the vertical direction, the smaller the welding amount. According to the manufacturing method of this shaped object, for example, in a place where it is difficult to increase the lamination height and easy to sag due to a large inclination of the lamination direction of the welding bead with respect to the vertical direction, the amount of sag can be suppressed by reducing the welding amount of the welding bead. Also, in a place where it is difficult to sag due to a small inclination with respect to the vertical direction, the shaped object can be efficiently shaped by increasing the welding amount of the welding bead.

[0073] (6) The manufacturing method of the shaped object according to any one of (1) to (5), wherein an upward welding bead formed upward in the inclination direction and a downward welding bead formed downward in the inclination direction are alternately laminated on the inclined surface. According to the manufacturing method of this shaped object, by alternately laminating the upward welding bead and the downward welding bead, the movement amount of the torch between passes can be shortened, and the productivity can be improved.

[0074] (7) The manufacturing method of the shaped object according to (6), wherein in the welding condition adjustment step, the welding amount of the upward welding bead is increased and the welding amount of the downward welding bead is decreased. According to the manufacturing method of this shaped object, by increasing the welding amount of the upward welding bead and decreasing the welding amount of the downward welding bead, the welding beads can be laminated in a well-balanced manner, and a shaped object closer to the target shape can be shaped.

[0075] (8) A manufacturing apparatus for a shaped object that melts a welding material to form a welding bead and shapes a shaped object on which the welding beads are laminated, An information acquisition unit that acquires lamination plan information including welding conditions, bead shapes, and lamination paths of the welding beads before lamination, and target shape information of a shaped object to be shaped; An integrated index calculation unit that calculates an integrated index of a lamination shape in which a plurality of the welding beads are laminated from the welding conditions, the bead shapes, and the lamination paths; A welding condition adjustment unit that adjusts the welding conditions based on the integrated index and the target shape information; A lamination shaping unit that repeatedly laminates the welding beads under the acquired welding conditions; It has The welding condition adjustment unit corrects at least the welding amount and the lamination position included in the welding conditions so that the bead width in the direction perpendicular to the lamination path approaches the same value in each layer and the deviation between the integrated index and the target shape is reduced. A manufacturing apparatus for shaped objects. According to this manufacturing apparatus for shaped objects, by preferentially laminating welding beads with the uniformity of the bead width, it is possible to suppress the sag of the welding beads when laminating the welding beads, and it is possible to easily adjust the lamination height of the shaped object. In addition, when matching the bead widths, the welding amount and bead height of each welding bead are not fixed, so the welding conditions can be flexibly adjusted according to the lamination location and lamination posture. In particular, it is possible to shape the overhang part and achieve good lamination on the inclined surface.

Explanation of Signs

[0076] 11 Torch 14 Shaped object 31 Information acquisition unit 35 Integrated index calculation unit 37 Welding condition adjustment unit 100 Lamination shaping system (lamination shaping unit, manufacturing apparatus) B Welding bead Bu Upward welding bead Bd Downward welding bead Ha Integrated height (integrated index) Ht Target height Si Inclined surface

Claims

1. A method for manufacturing a shaped object that melts a welding material to form a welding bead and shapes a shaped object in which the welding beads are stacked, comprising: an information acquisition step of acquiring lamination plan information including welding conditions, bead shapes, and lamination trajectories of the welding beads to be laminated, and target shape information of the shaped object to be shaped; an integrated index calculation step of calculating an integrated index of a laminated shape in which a plurality of the welding beads are laminated from the welding conditions, the bead shapes, and the lamination trajectories; a welding condition adjustment step of adjusting the welding conditions based on the integrated index and the target shape information; a laminated shaping step of repeatedly laminating the welding beads under the acquired welding conditions; and including in the welding condition adjustment step, the welding amount and the lamination position included in the welding conditions are corrected so that the bead width in the direction perpendicular to the lamination trajectory approaches the same value in each layer and the deviation between the integrated index and the target shape is reduced. A method for manufacturing a shaped object.

2. The welding condition adjustment step involves adjusting any one or a combination of the angle of the torch forming the welding bead, the welding speed of the welding bead, the feeding speed of the filler material fed to the torch, the welding current of the welding bead, the welding voltage of the welding bead, the torch movement direction, and the weaving condition of the torch. The method for manufacturing a shaped object according to Claim 1.

3. The welding condition adjustment step corrects the number of layers and corrects the welding amount so as to decrease the welding amount and increase the number of layers. The method for manufacturing a shaped object according to Claim 1.

4. The method further includes a shape profile acquisition step of measuring the shape of the stacked welding beads to acquire a shape profile, and correcting the integrated index based on the acquired shape profile. The method for manufacturing a shaped object according to Claim 1.

5. In the welding condition adjustment step, the welding amount is adjusted so that the larger the inclination angle of the lamination direction of the welding bead with respect to the vertical direction, the smaller the welding amount. The method for manufacturing a shaped object according to Claim 1.

6. For an inclined surface, the upward welding beads formed upward in the inclination direction and the downward welding beads formed downward in the inclination direction are alternately laminated. The method for manufacturing a shaped object according to any one of Claims 1 to 5.

7. In the welding condition adjustment step, the welding amount of the upward welding beads is increased and the welding amount of the downward welding beads is decreased. The method for manufacturing a shaped object according to Claim 6.

8. ​ A manufacturing apparatus for a shaped object that melts a welding material to form a welding bead and shapes a shaped object in which the welding beads are stacked, an information acquisition unit that acquires lamination plan information including welding conditions, bead shape, and lamination trajectory of the welding beads to be laminated, and target shape information of the shaped object to be shaped; an integrated index calculation unit that calculates an integrated index of a laminated shape in which a plurality of the welding beads are laminated from the welding conditions, the bead shape, and the lamination trajectory; a welding condition adjustment unit that adjusts the welding conditions based on the integrated index and the target shape information; a laminated shaping unit that repeatedly laminates the welding beads under the acquired welding conditions; comprising: the welding condition adjustment unit at least corrects the welding amount and the lamination position included in the welding conditions so that the bead width in the direction perpendicular to the lamination trajectory approaches the same value in each layer and reduces the deviation between the integrated index and the target shape; a manufacturing apparatus for a shaped object.

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