Control Method and Control Device of Additive Manufacturing Apparatus, and Program

Abstract

To manage a space amount required by a closing path and to automatically set an adequate welding condition to the space amount.SOLUTION: A control method of a lamination molding device acquires a lamination condition of weld beads to be formed by moving a welding torch and a setting value of a bead shape. It measures an opening defined between weld beads formed on the basis of the lamination condition or the weld bead and a peripheral member and a shape around the opening to acquire a shape profile including the opening. The shape profile specifies a space amount showing the size of the space of the opening or a representative position of the opening. The success or failure of closing of the opening is determined by comparing the space amount with the setting value of the bead shape or comparing information of the representative position with a target position of the weld bead included in the lamination condition about a closing path closing the opening by a weld bead formed on the basis of the lamination condition. The lamination condition of the closing path is corrected in the case of determining that the opening cannot be closed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a control method and a control device for a laminated manufacturing apparatus, and a program.

Background Art

[0002] In recent years, the need for manufacturing parts by laminated manufacturing using a 3D printer has been increasing, and research and development have been promoted toward practical use of manufacturing using a metal material. For example, Patent Document 1 discloses a laminated manufacturing apparatus that laminates weld beads formed by melting a metal welding wire to form a three-dimensional structure. In the laminated manufacturing apparatus of Patent Document 1, illumination light is irradiated from a measurement illumination unit, a cross-sectional height distribution of a manufactured object is calculated based on a detection result of reflected light, and a width of the manufactured object is calculated based on the cross-sectional height distribution. Processing conditions are controlled according to the width of this manufactured object.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in manufacturing by laminating weld beads, depending on the manufacturing shape, horizontal lamination in which weld beads are laminated in the horizontal direction, or manufacturing of an overhang shape may be required. In such manufacturing, due to melting of the weld beads or the like, the size of the weld beads may differ between the lamination plan and the actual situation. In that case, when joining the weld beads to each other or joining a weld bead and another member after horizontal lamination or overhang manufacturing, the width (space amount at the time of closing) required for the weld bead of the closing path that closes the joining part changes along the longitudinal direction of the bead. When closing is performed in such a state, a difference in quality occurs at each location due to the difference in the space amount, which causes problems in terms of strength and quality control.

[0005] Therefore, an object of the present invention is to provide a control method, a control device, and a program for a laminating apparatus that manage the amount of space required for a closed path and can automatically set appropriate welding conditions for the amount of space. **Means for Solving the Problems**

[0006] The present invention has the following configuration. (1) A control method for a laminating apparatus that includes a manipulator that moves a welding torch and forms a workpiece by laminating welding beads formed at the tip of the welding torch, the method comprising: obtaining design values of lamination conditions and bead shapes of the welding beads formed by the movement of the welding torch; measuring the shape of an opening and the shape around the opening defined between the welding beads formed based on the lamination conditions or between the welding bead and a surrounding member, and obtaining a shape profile including the opening; identifying a space amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile; for a closing path that closes the opening with a welding bead formed based on the lamination conditions, determining the success or failure of closing the opening by comparing the space amount with the design value of the bead shape, or by comparing the information of the representative position with the target position of the welding bead included in the lamination conditions; correcting the lamination conditions of the closing path when it is determined that the opening cannot be closed by the closing path; A control method for a laminating apparatus. (2) A control device for a laminating apparatus that includes a manipulator that moves a welding torch and forms a workpiece by laminating welding beads formed at the tip of the welding torch, the control device comprising: a condition acquisition unit that obtains design values of lamination conditions and bead shapes of the welding beads formed by the movement of the welding torch; a profile measurement unit that measures the shape of an opening and the shape around the opening defined between the welding beads formed based on the lamination conditions or between the welding bead and a surrounding member, and obtains a shape profile including the opening; A specifying unit that specifies a space amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile; A determination unit that determines whether or not the opening is closed by comparing the space amount with a designed value of the bead shape, or by comparing information on the representative position with a target position of the weld bead included in the lamination conditions, for a closing path that closes the opening with a weld bead formed based on the lamination conditions; A correction unit that corrects the lamination conditions of the closing path when it is determined that the opening cannot be closed by the closing path; A control device for a lamination molding apparatus including the above. (3) A program that executes a control procedure for a lamination molding apparatus that includes a manipulator that moves a welding torch and laminates weld beads formed at the tip of the welding torch to form a molded object, causing a computer to acquire lamination conditions for the weld bead formed by the movement of the welding torch and a designed value of the bead shape; measure the shape of an opening defined between the weld beads formed based on the lamination conditions or between the weld bead and a surrounding member and around the opening, and obtain a shape profile including the opening; specify a space amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile; determine whether or not the opening is closed by comparing the space amount with a designed value of the bead shape, or by comparing information on the representative position with a target position of the weld bead included in the lamination conditions, for a closing path that closes the opening with a weld bead formed based on the lamination conditions; correct the lamination conditions of the closing path when it is determined that the opening cannot be closed by the closing path; A program for executing the above.

Advantages of the Invention

[0007] According to the present invention, it is possible to manage the amount of space required for a closed path and automatically set appropriate welding conditions for the amount of space.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. The laminating apparatus shown here is an example, and as long as it is an apparatus that includes a manipulator that holds a welding torch and laminates welding beads formed at the tip of the welding torch based on set lamination conditions to form a shaped object, other configurations may be used.

[0010] <Configuration of Additive Manufacturing Apparatus> FIG. 1 is a schematic diagram showing the overall configuration of the additive manufacturing apparatus. The additive manufacturing apparatus 100 includes a control device 11 and a manufacturing unit 13. The manufacturing unit 13 includes a manipulator 15, a filler supply unit 17, a manipulator control unit 19, a heat source control unit 21, and a shape detection unit 23.

[0011] The manipulator control unit 19 controls the manipulator 15 and the heat source control unit 21. A controller (not shown) is connected to the manipulator control unit 19, and any operation of the manipulator control unit 19 can be instructed from an operator via the controller.

[0012] The manipulator 15 is, for example, an articulated robot, and the filler M is supported so as to be continuously supplied to a welding torch 25 provided on the tip axis. The welding torch 25 holds the filler M in a state of protruding from the tip. The position and orientation of the welding torch 25 can be arbitrarily set three-dimensionally within the range of the degrees of freedom of the robot arm constituting the manipulator 15. The manipulator 15 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 15 may have various forms, such as an articulated robot with four or more axes shown in FIG. 1, or a robot provided with an angle adjustment mechanism on two or more orthogonal axes.

[0013] The welding torch 25 has a shield nozzle (not shown), and shielding gas is supplied from the shield nozzle. The shielding gas blocks the atmosphere, prevents oxidation, nitriding, 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 disposed inside the shield nozzle, and the filler metal M to which current is supplied is held by the contact tip. The welding torch 25 generates an arc from the tip of the filler metal M in a shielding gas atmosphere while holding the filler metal M.

[0014] The filler metal supply unit 17 supplies the filler metal M toward the welding torch 25. The filler metal supply unit 17 includes a reel 17a around which the filler metal M is wound and a feeding mechanism 17b that feeds out the filler metal M from the reel 17a. The filler metal M is fed to the welding torch 25 while being fed in the forward or reverse direction as needed by the feeding mechanism 17b. The feeding mechanism 17b is not limited to the push type disposed on the filler metal supply unit 17 side to extrude the filler metal M, and may be a pull type disposed on a robot arm or the like, or a push-pull type.

[0015] The heat source control unit 21 is a welding power source that supplies the power required for welding by the manipulator 15. The heat source control unit 21 adjusts the welding current and welding voltage supplied during bead formation for melting and solidifying the filler metal M. Further, in conjunction with the welding conditions such as the welding current and welding voltage set by the heat source control unit 21, the filler metal supply speed of the filler metal supply unit 17 is adjusted.

[0016] The heat source for melting the filler material M is not limited to the above-described arc. For example, other heating methods such as a heating method that combines an arc and a laser, a heating method that uses a plasma, a heating method that uses an electron beam or a laser, etc. may be adopted. When heating with an electron beam or a laser, the heating amount can be controlled more finely, the state of the bead to be formed can be maintained more appropriately, and it can contribute to further improvement in the quality of the laminated structure. Also, the material of the filler material M is not particularly limited. For example, depending on the characteristics of the shaped object Wk, the type of filler material M used may be different, such as mild steel, high-tensile steel, aluminum, aluminum alloy, nickel, nickel-based alloy, etc.

[0017] The shape detection unit 23 is provided at the tip axis of the manipulator 15 or in the vicinity of the tip axis, and the vicinity of the tip of the welding torch 25 is set as the measurement region. The shape detection unit 23 may be other detection means provided at a position different from the welding torch 25.

[0018] The shape detection unit 23 of this configuration is moved together with the welding torch 25 by the drive of the manipulator 15, and measures the shape of the welding bead B and the portion serving as the base when forming the welding bead B, etc. As this shape detection unit 23, for example, a laser displacement sensor that acquires the reflected light of the irradiated laser light as height information can be used. Also, other detection means such as a camera for three-dimensional shape measurement may be used as the shape detection unit 23.

[0019] The control device 11 comprehensively controls each of the above-described units. The control device 11 is configured by hardware using an information processing device such as a PC (Personal Computer). Each function of the control device 11 is realized by a processor such as a CPU (Central Processing Unit) or an MPU (Micro Processor Unit), or a control device such as a dedicated circuit, 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 a memory such as a RAM (Random Access Memory) which is a volatile storage area and a ROM (Read Only Memory) which is a non-volatile storage area, and a storage such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). In addition to the above-described form, the control device 11 may be another computer remotely connected from the additive manufacturing apparatus 100 via a network or the like.

[0020] The additive manufacturing apparatus 100 having the above-described configuration operates according to a manufacturing program created based on the manufacturing plan of the workpiece Wk. The manufacturing 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 workpiece Wk. According to this manufacturing program, while moving the welding torch 25, when the supplied filler metal M is melted and solidified, a linear welding bead B which is a molten solid of the filler metal M is formed on the base 27. That is, the manipulator control unit 19 drives the manipulator 15 and the heat source control unit 21 based on a predetermined manufacturing program provided from the control device 11. The manipulator 15 moves the welding torch 25 while melting the filler metal M with an arc to form the welding bead B according to a command from the manipulator control unit 19. By sequentially forming and laminating the welding beads B in this way, a workpiece Wk having the desired shape is obtained.

[0021] Further, the control device 11 may have a function of outputting a drive signal for causing a machining device 33 having a cutting or polishing tool 31 such as an end mill or a drill provided on the tip shaft 29 to perform cutting or polishing of the weld bead B at a predetermined timing.

[0022] FIG. 2 is a functional block diagram of the control device 11. The control device 11 includes a condition acquisition unit 35, a profile measurement unit 37, a calculation unit 39, a determination unit 41, and a correction unit 43. Details of the functions of each of the above-described units will be described later.

[0023] FIGS. 3A and 3B are schematic views showing an opening when forming a partition wall having an internal space by laminating weld beads. As shown in FIG. 3A, a pair of weld beads B are formed at positions separated from each other on the base 27, and new weld beads B are laminated on each of the weld beads B. A pair of laminates 45 composed of a plurality of layers of weld beads B are formed by overhanging them so as to approach each other, and an opening 47 generated between the topmost weld beads Bt of each laminate 45 is closed by a weld bead Bc by the last pass (closed pass) of bead formation. In this way, an internal space 49 is formed inside the pair of laminates 45.

[0024] The above-described opening 47 is formed between the pair of laminates 45, but as shown in FIG. 3B, it may be formed between the topmost weld bead Bt of the laminate 45 and a surrounding member 51 such as an existing side wall or another member.

[0025] Figure 4 is a plan view of the opening 47 shown in FIG. 3A. In the actual opening 47, the shape of the welding bead B in the uppermost layer of the laminate 45 does not remain constant along the welding direction WD and is formed with different widths W. Therefore, when forming a laminate having an internal space by laminating the welding beads B, the control device 11 of the present configuration closes the openings 47 formed between the upper parts of a pair of laminates laminated from below with a welding bead of a closed path. At this time, the control device 11 measures the shape of the opening 47 before bead formation and corrects the formation conditions of the welding bead that closes the opening 47 according to the shape of the opening 47. The lamination conditions of the welding bead Bc by the closed path can be set in real time during the shaping so as to surely close the opening 47 according to the shape of the opening 47.

[0026] <Procedure from lamination of welding beads to closing of the opening> FIG. 5 is a flowchart showing a procedure for closing an opening formed by lamination of welding beads with a welding bead of a closed path. Each procedure is performed by each part of the control device 11 shown in FIG. 2 described above.

[0027] First, the condition acquisition unit 35 acquires the lamination conditions of the welding bead B to be laminated by the operation of the welding torch 25 shown in FIG. 1 and the design values of the bead shape (S1). The lamination conditions include information such as the formation track (path) of the welding bead B and the welding conditions of the welding bead B when forming the shaped object Wk with the welding bead B. Further, the information on the lamination conditions may be extracted from the shaping program described above.

[0028] Based on the acquired lamination conditions, the control device 11 drives the shaping unit 13 at a predetermined timing to form the welding bead B and start shaping (S2).

[0029] Next, the profile measurement unit 37 measures the shape of the opening 47 defined between the welding beads B formed based on the lamination conditions or between the welding bead B and other members to obtain a shape profile (S3). FIG. 6 is an explanatory diagram schematically showing a state of measurement of a shape profile. The shape detection unit 23 is disposed, for example, behind the welding torch 25 in the moving direction (welding direction WD) of the welding torch 25, and moves integrally with the movement of the welding torch 25. The shape detection unit 23 performs measurement based on the optical cutting method in which slit light is irradiated from an oblique direction toward the formed weld bead B and the reflected light of the irradiated slit light is detected. The method of shape detection is not limited to this, and other methods may be used.

[0030] FIG. 7 is an explanatory diagram showing a detection profile Prf of the detected reflected light. The region convex upward on the detection profile Prf of the reflected light indicates the position of the weld bead B. That is, the detection profile Prf of the reflected light becomes a shape profile showing the height information of the measurement object.

[0031] FIG. 8 is a graph showing the shape profile measured by the shape detection unit 23 by the profile measurement unit 37. This shape profile includes a pair of convex portions corresponding to a pair of weld beads B (laminated body 45) arranged to face each other, and a region corresponding to the opening 47 between the pair of convex portions. That is, as shown in FIG. 3A, the profile measurement unit 37 measures the shape of the uppermost layer portion (the uppermost weld bead Bt) where the pair of laminated bodies 45 each overhang and protrude the most.

[0032] Here, among the pair of convex portions, the vertex of one convex portion (the left convex portion) is defined as the first maximum height point P1, and the vertex of the other convex portion (the right convex portion) is defined as the second maximum height point P2. Further, the tip point protruding downward along the opening from the first maximum height point P1 is defined as the first protruding tip point P3, and the tip point protruding downward along the opening from the second maximum height point P2 is defined as the second protruding tip point P4.

[0033] The calculation unit 39 specifies a space amount indicating the size of the space of the opening or a representative position of the opening from the obtained shape profile (S4). Examples of the space amount include, but are not limited to, the width, depth, and cross-sectional area of the opening in a cross-section orthogonal to the bead formation direction (welding direction WD) of the weld bead.

[0034] For example, the width of the opening may include the width W1 (width between two points of the maximum height) between the first maximum height point P1 and the second maximum height point P2, and the width W2 (width between two points of the downward protruding points) between the first protruding tip point P3 and the second protruding tip point P4. Also, the depth of the opening may be the height difference between the higher one of the first maximum height point P1 and the second maximum height point P2 (here P1) and the lower one of the first protruding tip point P3 and the second protruding tip point P4 (here P4) as the depth D. This depth D represents the maximum depth in the opening of the measured shape profile. In addition, the difference between the average height of the first maximum height point P1 and the second maximum height point P2 and the average height of the first protruding tip point P3 and the second protruding tip point P4 may also be used as the depth D. The cross-sectional area A may be the area of a quadrilateral with the above-mentioned points P1, P2, P3, and P4 as vertices, or the area of the smallest circle enclosing the points P1, P2, P3, and P4, or the area of any geometric figure with the above-mentioned points as vertices.

[0035] The representative position is the position (coordinate) inside the geometric figure with the above-mentioned points P1, P2, P3, and P4 as vertices, and may be the position (coordinate) of the center point or the centroid point of the above-mentioned geometric figure.

[0036] Next, for the closing path that closes the opening 47 by the weld bead formed based on the lamination condition, the determination unit 41 determines whether the opening 47 is successfully closed by comparing the spatial amount with the design value of the bead shape, or by comparing the information of the representative position with the target position of the weld bead included in the lamination condition (S5).

[0037] Specifically, the size of the weld bead or the design value of the bead shape determined based on the lamination conditions is compared with the spatial amounts such as the widths W1 and W2, the depth D, and the cross-sectional area A of the region corresponding to the obtained opening. When the difference between the obtained spatial amount and the design value is greater than a predetermined threshold, it is determined that correction of the lamination conditions for the closed path is necessary. Further, for each of the above-described representative positions such as the points P1, P2, P3, and P4, the coordinates inside the geometric figure, and the coordinates of the center point or the centroid point, they are compared with the torch aiming position (bead formation trajectory) included in the lamination conditions. When the deviation amount (difference) between the obtained representative position and the torch aiming position is greater than a predetermined threshold, it is determined that correction of the lamination conditions for the closed path is necessary. These determinations may be performed only on one side or may be combined. In particular, when both are combined, the welding bead lamination conditions for the closed path can be precisely adjusted.

[0038] Note that when the shape of the opening greatly deviates from the designed shape and it is difficult to laminate the closed path, it may be determined whether to continue or interrupt the additive manufacturing as it is. For example, when local unevenness occurs in the opening and a narrow part is formed, if the weld bead is formed as it is, voids may occur in the narrow part. In that case, the control device 11 may control the machining device 33 shown in FIG. 1 at an appropriate timing to perform repairs such as cutting and polishing of the narrow part. According to this, the range of coping with the shape of the opening can be expanded.

[0039] When the determination unit 41 determines that the opening cannot be closed or that even if it can be closed, the state is not good, the correction unit 43 corrects the lamination conditions for the closed path (S6). As a result, for the closed path, lamination conditions corresponding to the actual shape of the opening are set. Then, a weld bead for the closed path is formed based on the newly set lamination conditions (S7).

[0040] Further, when the determination unit 41 determines that the opening can be closed, a weld bead for the closed path is formed with the set lamination conditions remaining as they are (S7).

[0041] In the closing pass for closing the opening 47, the sagging, deformation, etc. of the weld beads stacked in each lower layer path may accumulate, and in some cases, it may not be possible to close sufficiently under the original plan, that is, the designed stacking conditions. Therefore, in order to perform the shaping as planned, the stacking conditions of the closing pass are corrected according to the shape of the opening. The specific content of correcting the stacking conditions of this closing pass will be described below.

[0042] FIG. 9 is an explanatory diagram showing an opening and a closing pass for closing the opening. As shown in FIG. 9, consider the case where the width of the opening 47 varies and is not constant along the welding direction WD. In this case, for example, in a section where the width of the opening 47 is extremely narrow, such as the region K1 in FIG. 9, in order to suppress the welding amount, the wire feeding speed is decreased or the welding speed is increased compared to other sections. Conversely, for a section where the width becomes wider, in order to increase the welding amount, the wire feeding speed is increased or the welding speed is decreased.

[0043] When weaving is assumed in the closing pass, the weaving width for the region K1 may be made smaller than that of other regions. Furthermore, in order to prevent the weld bead of the closing pass from melting and falling after stacking, the heat input amount of the weld bead may be adjusted according to the above-described space amount. For example, when the width of the opening 47 is too narrow for the assumed space amount, the welding current or the welding voltage is decreased to reduce the heat input amount, and conversely, when the width is too wide, the welding current or the welding voltage is increased.

[0044] Also, the aiming position of the welding torch 25 in the closing pass for closing the opening 47 may be corrected to the representative position described above. For example, it may be corrected so that the aiming position becomes the center position or the centroid position of the opening 47. By doing so, the position of the welding torch 25 can be properly maintained, and the torch idle vibration where the aiming position of the welding torch and the position of the bead surface deviate and the weld bead is not formed as expected, and the interference with other members can be suppressed. Also, the opening 47 can be more surely closed with the weld bead of the closing pass.

[0045] The aiming position 53 of the welding torch 25 shown in FIG. 9 is preferably set on a line where the distances Wa and Wb from the welding beads B on both sides of the opening 47 are equal. However, there may be a section that is asymmetric in the width direction orthogonal to the welding direction WD, such as the region K2 in FIG. 9. In that case, an additional aiming position 53a may be added at a position offset from the center in the width direction so that the welding torch 25 is shifted in the width direction in the section of the region K. That is, the additional aiming position 53a is provided at a position biased toward either one side (the right side in FIG. 9) where the opening 47 is to be widened, out of a pair of opposing welding beads B forming the opening 47. By adding this aiming position 53a, the closed path is set to bend toward the side where the width of the opening 47 is widened, and the welding bead is piled up at the widened portion. For this reason, it is possible to close the opening 47 while suppressing the occurrence of distortion, lack of fusion, and unwelded portions.

[0046] As described above, according to the control method of the additive manufacturing apparatus, when joining welding beads to each other or a welding bead and another member after horizontal lamination or overhang shaping, the welding bead of the closed path that closes the joining portion can be formed under appropriate lamination conditions that satisfy the spatial amount such as the required width and required thickness for bead filling. Thereby, even when there is a difference in the size of the welding bead between the lamination plan and the actual situation, and a shape change occurs in the joining portion (opening 47), the lamination conditions corresponding to the shape change are automatically set, so that the joining quality of the opening can be improved. Therefore, there is no difference in quality for each location, and a shaped object with good strength and quality control can be obtained.

[0047] In addition, since the spatial amount or representative position of the opening between the welding beads is treated as a feature quantity for control, compared with the case where the shape itself of the welding bead to be formed is treated as a feature quantity, information such as the required amount of welding becomes accurate, and the opening can be closed more reliably.

[0048] The present invention is not limited to the above-described embodiments. It is also contemplated by the present invention that those skilled in the art can make changes and applications based on combining each configuration of the embodiments, the description of the specification, and well-known techniques, and these are included in the scope for which protection is sought.

[0049] As described above, the following matters are disclosed in this specification. (1) A control method for a laminating and forming apparatus that includes a manipulator for moving a welding torch and forms a shaped object by laminating welding beads formed at the tip of the welding torch, the method comprising: acquiring lamination conditions for the welding beads formed by the movement of the welding torch and design values of bead shapes; measuring the shape of an opening defined between the welding beads formed based on the lamination conditions or between the welding bead and a surrounding member, and the shape around the opening, to obtain a shape profile including the opening; identifying a space amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile; determining whether the opening can be closed by comparing the space amount with the design values of the bead shape or comparing the information of the representative position with the target position of the welding bead included in the lamination conditions for a closing path that closes the opening with the welding beads formed based on the lamination conditions; correcting the lamination conditions of the closing path when it is determined that the opening cannot be closed by the closing path; A control method for a laminating and forming apparatus. According to this control method for a laminating and forming apparatus, the shape of an opening formed by shaping is measured to obtain a shape profile, and it is possible to determine whether the opening can be closed by a closing path based on this shape profile. Therefore, when it is predicted that the opening cannot be closed, the lamination conditions of the closing path can be corrected to surely close the opening.

[0050] (2) The control method according to (1), wherein the space amount includes any one of the width, depth, and cross-sectional area of a region corresponding to the opening in the shape profile. According to this control method for a laminating and forming apparatus, since the space amount of any one of the width, depth, and cross-sectional area of a region corresponding to the opening can be easily calculated using the shape profile, the correction of the lamination conditions can be carried out earlier. That is, feedback control according to the space amount can be quickly executed, and the processing time can be shortened.

[0051] (3) The representative position is a point inside a geometric figure having as vertices each of a first maximum height point of one of a pair of convex portions sandwiching the opening in the shape profile, a first protruding tip point protruding downward from the first maximum height point to below the opening, a second maximum height point of the other convex portion, and a second protruding tip point protruding downward from the second maximum height point to below the opening, according to the control method of (1). According to the control method of this additive manufacturing apparatus, since each representative position can be easily calculated using the shape profile, correction of the lamination conditions can be carried out earlier. That is, feedback control according to the space amount can be quickly executed, and shortening of the processing time can be achieved.

[0052] (4) The correction of the lamination conditions for the closed path adjusts the deposition amount or heat input amount of the welding bead closing the opening according to the width of the opening obtained from the shape profile, according to the control method of (1). According to the control method of this additive manufacturing apparatus, when the width of the opening is different from the assumed width, the deposition amount is adjusted by increasing or decreasing the wire feeding speed and the welding speed, or the heat input amount is adjusted by increasing or decreasing the welding current and the welding voltage, so that the welding bead for the closed path can be formed under appropriate conditions. Thereby, over-deposition or under-deposition of beads and melting of the beads can be prevented.

[0053] (5) The correction of the lamination conditions for the closed path corrects the target position of the welding bead closing the opening to the representative position, according to the control method of (1). According to the control method of this additive manufacturing apparatus, by correcting the target position of the welding bead for the closed path to the representative position, the position of the welding torch is properly maintained, and idling of the torch and interference with other members can be suppressed.

[0054] (6) The correction of the lamination conditions for the closed path includes addition of the target position of the closed path. The control method according to (1), wherein the target position to be added is provided so as to be biased toward either one of a pair of opposing welding beads forming the opening, on the side where the opening is widened. According to the control method of this additive manufacturing apparatus, due to the addition of the target position, the closed path is bent and set toward the side where the width of the opening is widened, and welding beads are deposited at the widened portion. Therefore, the opening can be closed while suppressing the occurrence of distortion, lack of fusion, and unfused portions.

[0055] (7) A control device for an additive manufacturing apparatus that includes a manipulator that moves a welding torch and forms a workpiece by laminating welding beads formed at the tip of the welding torch, a condition acquisition unit that acquires design values of the lamination conditions and bead shapes of the welding beads formed by the movement of the welding torch, a profile measurement unit that measures the shape of the opening and the shape around the opening defined between the welding beads formed based on the lamination conditions or between the welding bead and the surrounding members, and obtains a shape profile including the opening, a specifying unit that specifies a spatial amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile, a determination unit that determines the success or failure of closing the opening by comparing the spatial amount with the design value of the bead shape or by comparing the information of the representative position with the target position of the welding bead included in the lamination conditions for the closed path that closes the opening with the welding bead formed based on the lamination conditions, a correction unit that corrects the lamination conditions of the closed path when it is determined that the opening cannot be closed by the closed path, A control device for an additive manufacturing apparatus comprising the above. According to the control device of this additive manufacturing apparatus, the shape of the opening formed by the shaping is measured to obtain a shape profile, and the success or failure of closing by the closed path that closes the opening can be determined from this shape profile. Therefore, when it is predicted that the opening cannot be closed, the opening can be surely closed by correcting the lamination conditions of the closed path.

[0056] (8) A program that executes a control procedure for a laminating manufacturing apparatus that includes a manipulator for moving a welding torch and manufactures a workpiece by laminating welding beads formed at the tip of the welding torch, causes a computer to acquire the lamination conditions for the welding beads formed by the movement of the welding torch and the design values of the bead shape, measure the shapes of the openings defined between the welding beads formed based on the lamination conditions or between the welding beads and surrounding members, and obtain a shape profile including the openings, specify a space amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile, for a closing path that closes the opening with welding beads formed based on the lamination conditions, determine the success or failure of closing the opening by comparing the space amount with the design values of the bead shape, or by comparing the information of the representative position with the target position of the welding bead included in the lamination conditions, correct the lamination conditions of the closing path when it is determined that the opening cannot be closed by the closing path, and is a program for executing the above. According to this program, the shape of the opening formed by manufacturing is measured to obtain a shape profile, and the success or failure of closing the opening by a closing path can be determined from this shape profile. Therefore, when it is predicted that the opening cannot be closed, the lamination conditions of the closing path can be corrected to surely close the opening.

Explanation of Signs

[0057] 11 Control device 13 Manufacturing part 15 Manipulator 17 Filler material supply part 17a Reel 17b Pay-out mechanism 19 Manipulator control part 21 Heat source control part 23 Shape detection part 25 Welding torch 27 Base 29 Tip shaft 31 Tool 33 Machining device 35 Condition acquisition unit 37 Profile measurement unit 39 Calculation unit 41 Judgment unit 43 Correction unit 45 Laminate 47 Opening 49 Internal space 51 Surrounding member 53, 53a Aiming position 100 Additive manufacturing apparatus A Cross-sectional area B, Bc, Bt Weld bead Bc Weld bead D Depth K1, K2 Region M Filler material P1 First maximum height point P2 Second maximum height point P3 First protruding tip point P4 Second protruding tip point Prf Detection profile W, W1, W2 Width WD Welding direction Wk Formed object

Claims

1. A control method for a laminated manufacturing apparatus that includes a manipulator for moving a welding torch and manufactures a shaped object by laminating welding beads formed at the tip of the welding torch, the method comprising: obtaining lamination conditions for the welding beads formed by the movement of the welding torch and design values of bead shapes; measuring the shape of an opening defined between the welding beads formed based on the lamination conditions or between the welding bead and a surrounding member, and the shape around the opening, to obtain a shape profile including the opening; identifying a space amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile; determining the success or failure of closing the opening by comparing the space amount with the design value of the bead shape or by comparing the information on the representative position with the target position of the welding bead included in the lamination conditions for a closing path that closes the opening with a welding bead formed based on the lamination conditions; correcting the lamination conditions of the closing path when it is determined that the opening cannot be closed by the closing path; The representative position is a point inside a geometric figure having as vertices each of a first maximum height point of one of a pair of convex portions sandwiching the opening in the shape profile, a first protruding tip point protruding downward from the first maximum height point toward the opening, a second maximum height point of the other convex portion, and a second protruding tip point protruding downward from the second maximum height point toward the opening. A control method for a laminated manufacturing apparatus.

2. The space amount includes any one of the width, depth, and cross-sectional area of a region corresponding to the opening in the shape profile. The control method according to claim 1.

3. The correction of the lamination conditions of the closing path adjusts the welding amount or heat input amount of the welding bead that closes the opening according to the width of the opening obtained from the shape profile. The control method according to claim 1.

4. The correction of the lamination conditions of the closing path corrects the target position of the welding bead that closes the opening to the representative position. The control method according to claim 1.

5. The correction of the lamination conditions of the closing path includes adding a target position of the closing path. The added target position is provided so as to be biased toward one side that widens the opening among a pair of opposing welding beads that form the opening. The control method according to claim 1.

6. A control device for a layered manufacturing apparatus that includes a manipulator for moving a welding torch and manufactures a shaped object by laminating welding beads formed at the tip of the welding torch, a condition acquisition unit that acquires lamination conditions of the welding beads formed by the movement of the welding torch and design values of bead shapes, a profile measurement unit that measures the shape of an opening defined between the welding beads formed based on the lamination conditions or between the welding bead and a surrounding member and the shape around the opening, and obtains a shape profile including the opening, a specifying unit that specifies a space amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile, a determination unit that determines whether the opening can be closed or not by comparing the space amount with the design value of the bead shape or comparing the information of the representative position with the target position of the welding bead included in the lamination conditions for a closing path that closes the opening with the welding bead formed based on the lamination conditions, a correction unit that corrects the lamination conditions of the closing path when it is determined that the opening cannot be closed by the closing path, and the representative position is a point inside a geometric figure having as vertices each point of a first maximum height point of one of a pair of convex portions sandwiching the opening in the shape profile, a first protruding tip point protruding downward from the first maximum height point to the opening, a second maximum height point of the other convex portion, and a second protruding tip point protruding downward from the second maximum height point to the opening. A control device for a layered manufacturing apparatus. **Claim 7** A program that executes a control procedure for a layered manufacturing apparatus that includes a manipulator for moving a welding torch and manufactures a shaped object by laminating welding beads formed at the tip of the welding torch, the program causes a computer to perform a procedure for acquiring lamination conditions of the welding beads formed by the movement of the welding torch and design values of bead shapes, perform a procedure for measuring the shape of an opening defined between the welding beads formed based on the lamination conditions or between the welding bead and a surrounding member and the shape around the opening, and obtaining a shape profile including the opening, perform a procedure for specifying a space amount indicating the size of the space of the opening or a representative position of the opening based on the shape profile, Regarding the closing path that closes the opening with a weld bead formed based on the lamination condition, a procedure for determining whether the opening is closed by comparing the space amount with the design value of the bead shape or by comparing the information of the representative position with the target position of the weld bead included in the lamination condition, When it is determined that the opening cannot be closed by the closing path, a procedure for correcting the lamination condition of the closing path is executed, The representative position is a point inside a geometric figure having as vertices each point of the first maximum height point of one of a pair of convex portions sandwiching the opening in the shape profile, the first protruding tip point protruding downward from the first maximum height point to below the opening, the second maximum height point of the other convex portion, and the second protruding tip point protruding downward from the second maximum height point to below the opening. Program.

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