Molding data creation device, three-dimensional laminate molding system and three-dimensional laminate molding method

Abstract

To provide a technique to reduce a variation of sparsity / density of scanning lines when generating the scanning lines for molding an article by three-dimensional laminate molding.SOLUTION: A molding data creation device creates molding data for controlling a three-dimensional laminate molding device configured to melt cross-sectional shapes of respective layers by irradiation of beams to mold an article. The molding data creation device includes a molding date generation part configured to: generate a plurality of scanning lines in a prescribed beam scanning method to a region of a cross-sectional shape cut out from three-dimensional shape data of an article; and generate a correction scanning line to a portion where an arrangement of the scanning lines is sparse and / or a portion where the arrangement is dense.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a modeling data creation device, a three-dimensional additive manufacturing system, and a three-dimensional additive manufacturing method. [Background technology]

[0002] Powder bed fusion is known as one of the molding methods for forming an object. The powder bed fusion is a molding method in which a beam is selectively irradiated onto the surface of a powder layer (hereinafter also referred to as the "molding surface") formed by spreading powder to a predetermined thickness, thereby melting and solidifying a cross-sectional shape of the object to be molded. In the powder bed fusion method, the molding plate is lowered in sequence each time the powder of each layer is melted and solidified, thereby stacking the powder layers one by one to form an object (part, etc.). A three-dimensional additive manufacturing device employing the powder bed fusion method is described in Patent Document 1, for example.

[0003] The operation of the three-dimensional additive manufacturing device is controlled according to an operation sequence program (hereinafter also referred to as "modeling data") that is prepared in advance based on three-dimensional shape data. Three-dimensional shape data is data that specifies the three-dimensional shape of an object generated by three-dimensional CAD (Computer-Aided Design) or the like. The modeling data is created by a computer device (hereinafter referred to as a "modeling data creation device") incorporating a program generally called CAM (Computer Aided Manufacturing) software, using three-dimensional shape data of the object to be modeled. CAM software can be executed by any computer.

[0004] The CAM software process in the modeling data creation device first cuts out the cross-sectional shapes of each layer at intervals of one layer's thickness from the input three-dimensional shape data. Next, modeling data for melting the cross-sectional shapes of each layer is generated. The modeling data includes data on the scanning lines for melting the cross-sectional shapes of each layer by beam scanning. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-7065 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in a conventional modeling data creation device, when multiple scanning lines are generated in a region of the cross-sectional shape of each layer using a predetermined beam scanning method, there are cases where the scanning lines are too far apart or too close together. Therefore, when a three-dimensional additive manufacturing device is operated based on modeling data created by the modeling data creation device, melting defects due to insufficient melting are likely to occur in the areas where the scanning lines are too far apart, and melting defects due to excessive melting are likely to occur in the areas where the scanning lines are too close together.

[0007] The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a technology that can reduce variations in density of scanning lines when generating scanning lines for manufacturing an article by three-dimensional additive manufacturing. [Means for solving the problem]

[0008] The modeling data creation device of the present invention is a modeling data creation device that creates modeling data to control a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating it with a beam to form an object, and is equipped with a modeling data generation unit that generates multiple scanning lines using a predetermined beam scanning method in an area of ​​the cross-sectional shape cut out from the three-dimensional shape data of the object, and generates correction scanning lines in areas where the scanning lines are sparsely arranged and / or densely arranged.

[0009] The three-dimensional additive manufacturing system of the present invention is a three-dimensional additive manufacturing system comprising a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating it with a beam to form an object, and a modeling data creation device that creates modeling data for controlling the three-dimensional additive manufacturing device, wherein the modeling data creation device generates multiple scanning lines using a predetermined beam scanning method in an area of ​​the cross-sectional shape cut out from the three-dimensional shape data of the object, and comprises a modeling data generation unit that generates corrective scanning lines in areas where the scan lines are sparsely arranged and / or densely arranged, and the three-dimensional additive manufacturing device forms the object by scanning the beam along the multiple scanning lines and the corrective scanning lines.

[0010] The three-dimensional additive manufacturing method of the present invention is a three-dimensional additive manufacturing method in which the cross-sectional shape of each layer is melted by irradiating it with a beam to form an article, in which multiple scanning lines are generated in an area of ​​the cross-sectional shape cut out from the three-dimensional shape data of the article using a predetermined beam scanning method, and correction scanning lines are generated in areas where the scan lines are sparsely arranged and / or densely arranged, and the article is formed by scanning the beam along the multiple scanning lines and the correction scanning lines. Effect of the Invention

[0011] According to the present invention, when generating scanning lines for manufacturing an article by three-dimensional additive manufacturing, it is possible to reduce variations in the density of the scanning lines. [Brief description of the drawings]

[0012] [Figure 1] 1 is a side view showing a schematic configuration of a three-dimensional additive manufacturing apparatus according to a first embodiment of the present invention; [Diagram 2] 2 is a block diagram showing an example of the configuration of a control system of the three-dimensional additive manufacturing apparatus according to the first embodiment of the present invention. FIG. [Diagram 3] 4 is a flowchart showing a procedure of a processing operation of the three-dimensional additive manufacturing apparatus according to the first embodiment of the present invention. [Figure 4] 1 is a diagram showing an example of the configuration of a three-dimensional additive manufacturing system according to a first embodiment of the present invention. [Diagram 5]1 is a block diagram showing an example of the configuration of a modeling data creating apparatus according to a first embodiment of the present invention. [Figure 6] 4 is a flowchart showing an example of a processing procedure of the modeling data creating apparatus according to the first embodiment of the present invention. [Figure 7] FIG. 2 is a diagram (part 1) for explaining the contents of a process performed by a shaping data generating unit of the shaping data creating device in the first embodiment of the present invention. [Figure 8] FIG. 2 is a diagram (part 2) illustrating the contents of the process performed by the shaping data generating unit of the shaping data creating device in the first embodiment of the present invention. [Figure 9] FIG. 11 is a diagram (part 3) for explaining the contents of the process performed by the shaping data generating unit of the shaping data creating device in the first embodiment of the present invention. [Figure 10] FIG. 4 is a diagram (part 4) illustrating the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention. [Figure 11] FIG. 5 is a fifth diagram for explaining the contents of the process performed by the shaping data generating unit of the shaping data creating device in the first embodiment of the present invention. [Figure 12] FIG. 6 is a diagram (part 6) illustrating the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention. [Figure 13] FIG. 7 is a diagram for explaining the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention; [Figure 14] FIG. 8 is a diagram (part 8) illustrating the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention. [Figure 15] FIG. 9 is a diagram for explaining the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention. [Figure 16] FIG. 10 is a diagram (part 10) illustrating the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention. [Figure 17]FIG. 11 is an eleventh diagram for explaining the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention. [Figure 18] FIG. 12 is a twelfth diagram illustrating the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention. [Figure 19] FIG. 13 is a thirteenth diagram for explaining the contents of the process performed by the shaping data generating unit of the shaping data creating device in the first embodiment of the present invention. [Figure 20] FIG. 14 is a diagram (part 14) illustrating the contents of the process performed by the shaping data generation unit of the shaping data creation device in the first embodiment of the present invention. [Figure 21] 13 is a diagram (part 1) for explaining the contents of a process performed by a shaping data generating unit of a shaping data creating apparatus in a second embodiment of the present invention. FIG. [Figure 22] FIG. 13 is a diagram (part 2) illustrating the contents of the process performed by the shaping data generating unit of the shaping data creating device in the second embodiment of the present invention. [Figure 23] FIG. 13 is a diagram (part 3) for explaining the contents of the process performed by the shaping data generating unit of the shaping data creating device in the second embodiment of the present invention. [Figure 24] FIG. 11 is a fourth diagram for explaining the contents of the process performed by the shaping data generating unit of the shaping data creating device in the second embodiment of the present invention. [Diagram 25] FIG. 13 is a fifth diagram for explaining the contents of the process performed by the shaping data generating unit of the shaping data creating device in the second embodiment of the present invention. [Figure 26] FIG. 13 is a diagram (part 6) illustrating the contents of the process performed by the shaping data generation unit of the shaping data creation device in the second embodiment of the present invention. [Figure 27] FIG. 13 is a seventh diagram for explaining the contents of the process performed by the shaping data generating unit of the shaping data creating device in the second embodiment of the present invention; [Figure 28] FIG. 8 is a diagram (part 8) illustrating the contents of the process performed by the shaping data generation unit of the shaping data creation device in the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In this specification and the drawings, elements having substantially the same function or configuration are given the same reference numerals, and duplicated descriptions are omitted. In addition, the following description and drawings are examples for explaining the present invention, and may be omitted or simplified for convenience of explanation. Each component may be singular or plural unless otherwise limited. In addition, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0014] First Embodiment Fig. 1 is a side view showing a schematic configuration of a three-dimensional additive manufacturing apparatus according to a first embodiment of the present invention. In the following description, in order to clarify the shapes and positional relationships of each part of the three-dimensional additive manufacturing apparatus, the left-right direction in Fig. 1 is defined as the X direction, the depth direction in Fig. 1 as the Y direction, and the up-down direction in Fig. 1 as the Z direction. The X direction, Y direction, and Z direction are mutually orthogonal. Moreover, the X direction and Y direction are parallel to the horizontal direction, and the Z direction is parallel to the vertical direction.

[0015] As shown in FIG. 1, the three-dimensional additive manufacturing apparatus 10 includes a vacuum chamber 12, a beam irradiation device 14, a powder coating device 16, a modeling table 18, a modeling box 20, a collection box 21, a modeling plate 22, an inner base 24, and a plate moving device 26. The three-dimensional additive manufacturing apparatus 10 models an article (hereinafter, also referred to as a "modeled object") by the above-mentioned powder bed fusion method. In this embodiment, the case where the beam irradiated to the surface of the powder layer is a charged particle beam, more specifically, an electron beam, is taken as an example for explanation. However, the beam is not limited to a charged particle beam, and may be, for example, a laser beam. When a laser beam is adopted, it is not necessary to evacuate the chamber.

[0016] The vacuum chamber 12 is a chamber for creating a vacuum state by exhausting the air inside the chamber with a vacuum pump (not shown). The vacuum chamber 12 corresponds to a modeling chamber that forms a space for modeling a three-dimensional object 38. The modeling chamber forms a space for modeling a three-dimensional object.

[0017] The beam irradiation device 14 is a device that irradiates the surface of the powder layer 32a, i.e., the forming surface 32b, with an electron beam 15. The electron beam 15 is an example of a charged particle beam. The beam irradiation device 14 has an electron gun 141 that is a source of the electron beam 15, a converging lens 142 that converges the electron beam 15 generated by the electron gun 141, and a deflection device 143 that deflects the electron beam 15.

[0018] The converging lens 142 is configured using a converging coil, and converges the electron beam 15 by a magnetic field generated by the converging coil. The size of the electron beam 15 on the printing surface 32b can be adjusted by the converging lens 142. The deflection device 143 is configured using a deflection coil, and deflects the electron beam 15 by a magnetic field generated by the deflection coil. Scanning of the electron beam 15 on the printing surface 32b is achieved by the deflection device 143.

[0019] The powder coating device 16 is a device that coats the metal powder 32, which is the raw material of the molded object 38, on the molding plate 22 to form a powder layer 32a. The metal powder 32 is an example of a powder that is the raw material of the molded object 38. The powder coating device 16 has a hopper 16a, a powder dropper 16b, and a squeegee 16c. The hopper 16a is a container for storing powder. The powder dropper 16b is a device that drops the powder stored in the hopper 16a onto the molding table 18. The squeegee 16c is a long member that is long in the Y direction. The squeegee 16c moves horizontally on the molding plate 22 from one end side to the other end side of the molding table 18 to spread the metal powder 32. As a result, the powder layer 32a is formed on the molding plate 22. The squeegee 16c is provided so as to be movable in the X direction in order to spread the metal powder 32 over the entire surface of the molding table 18.

[0020] The modeling table 18 is arranged horizontally inside the vacuum chamber 12. The modeling table 18 is arranged below the powder coating device 16. The center of the modeling table 18 is open. The shape of the opening of the modeling table 18 is circular or angular (e.g., rectangular) when viewed from above.

[0021] The modeling box 20 is a box that supports the inner base 24 so that it can move up and down. The modeling box 20 forms a space for stacking the metal powder 32 applied by the powder application device 16 on the inner base 24. The upper end of the modeling box 20 is connected to the edge of the opening of the modeling table 18. The lower end of the modeling box 20 is connected to the bottom wall of the vacuum chamber 12.

[0022] The recovery box 21 is a box for recovering metal powder 32 that is supplied in excess of the amount of metal powder 32 that is supplied onto the modeling table 18 by the powder coating device 16. The recovery box 21 is provided on each side in the X direction.

[0023] The shaping plate 22 is a plate for forming a shaped object 38 using the metal powder 32. The shaped object 38 is formed by stacking on the shaping plate 22. The shaping plate 22 is formed to be circular or angular in plan view to match the opening shape of the shaping table 18. The shaping plate 22 is connected (grounded) to the inner base 24 by an earth wire 34 so as not to be in an electrically floating state. The inner base 24 is held at a GND (ground) potential. The metal powder 32 is spread over the shaping plate 22 and the inner base 24.

[0024] The inner base 24 is provided so as to be movable in the vertical direction (Z direction). The shaping plate 22 moves vertically together with the inner base 24. The inner base 24 has outer dimensions larger than those of the shaping plate 22. The inner base 24 slides vertically along the inner surface of the shaping box 20. A sealing member 36 is attached to the outer periphery of the inner base 24. The sealing member 36 is a member that maintains slidability and airtightness between the outer periphery of the inner base 24 and the inner surface of the shaping box 20. The sealing member 36 is made of a material that is heat-resistant and elastic.

[0025] The plate moving device 26 is a device that moves the shaping plate 22 and the inner base 24 in the up-down direction. The plate moving device 26 includes a shaft 26a and a drive mechanism unit 26b. The shaft 26a is connected to the lower surface of the inner base 24. The drive mechanism unit 26b includes a motor and a power transmission mechanism (not shown), and moves the shaping plate 22 and the inner base 24 together with the shaft 26a in the up-down direction by driving the power transmission mechanism using the motor as a drive source. The power transmission mechanism is configured by, for example, a rack-and-pinion mechanism, a ball screw mechanism, or the like.

[0026] FIG. 2 is a block diagram showing an example of the configuration of a control system of the three-dimensional additive manufacturing apparatus according to the first embodiment of the present invention. 2, the control unit 50 is configured by a computer including a processor 50a such as a CPU (Central Processing Unit) and a storage unit 50b such as a ROM (Read Only Memory), a RAM (Random Access Memory), a HDD (Hard Disk Drive), and an SSD (Solid State Drive). The control unit 50 centrally controls the operation of the three-dimensional additive manufacturing apparatus 10 by having the processor read out a program written in advance in the ROM into the RAM and execute it. The control unit 50 also controls the operation of the entire three-dimensional additive manufacturing apparatus 10 according to modeling data, which will be described later. The beam irradiation device 14, the powder coating device 16, and the plate moving device 26 are connected to the control unit 50 as objects to be controlled.

[0027] The beam irradiation device 14 irradiates the electron beam 15 based on a control command given from the control unit 50. At that time, the control unit 50 controls the electron beam 15 via the electron gun 141, the convergent lens 142, and the deflection device 143. For example, the control unit 50 controls the beam current amount of the electron beam 15 via the beam irradiation device 14. The control unit 50 also controls the spot size of the electron beam 15 via the convergent lens 142. The spot size of the electron beam 15 is the size of the electron beam 15 on the printing surface 32b. The control unit 50 also controls the deflection angle and deflection speed of the electron beam 15 via the deflection device 143. The deflection angle of the electron beam 15 is a control parameter that determines the irradiation position of the electron beam 15. The deflection speed of the electron beam 15 is a control parameter that determines the scanning speed of the electron beam 15. The scanning speed of the electron beam 15 can be rephrased as the moving speed of the electron beam 15 on the printing surface 32b.

[0028] The plate moving device 26 moves the shaping plate 22 and the inner base 24 based on a control command given from the control unit 50. The powder coating device 16 applies metal powder 32 onto the shaping plate 22 based on a control command given from the control unit 50 to form a powder layer 32a. The operations of the hopper 16a, powder dropper 16b, and squeegee 16c of the powder coating device 16 are controlled by the control unit 50.

[0029] <Operation of 3D additive manufacturing device> 3 is a flowchart showing the procedure of the processing operation of the three-dimensional additive manufacturing apparatus according to the first embodiment of the present invention. The processing operation shown in this flowchart is performed under the control of the control unit 50.

[0030] Before the start of modeling, the periphery of the modeling plate 22, except for the upper surface of the modeling plate 22, is covered with the metal powder 32. In addition, the upper surface of the modeling plate 22 is disposed at approximately the same height as the upper surface of the metal powder 32 spread on the modeling table 18.

[0031] (Plate heating process) First, the beam irradiation device 14 operates based on a control command given from the control unit 50 to heat the modeling plate 22 (step S1). In step S1, the beam irradiation device 14 irradiates the manufacturing plate 22 with the electron beam 15. As a result, the manufacturing plate 22 is heated to a temperature at which the metal powder 32 is pre-sintered.

[0032] (Plate lowering process) Next, the plate moving device 26 operates based on a control command given from the control unit 50 to lower the modeling plate 22 by a predetermined amount (step S2). In step S2, the plate moving device 26 lowers the inner base 24 by a predetermined amount so that the upper surface of the shaping plate 22 is slightly lower than the upper surface of the metal powder 32 spread on the shaping table 18. At this time, the shaping plate 22 is lowered by a predetermined amount together with the inner base 24. This predetermined amount (hereinafter, also referred to as "ΔZ") corresponds to the thickness of one layer when the shaped object 38 is shaped by stacking.

[0033] (Powder coating process) Next, the powder coating device 16 operates based on a control command given from the control unit 50 to coat the metal powder 32 onto the shaping plate 22 to form a powder layer 32a (step S3). In step S3, the powder coating device 16 drops the metal powder 32 supplied from the hopper 16a to the powder dropper 16b onto the modeling table 18 using the powder dropper 16b, and then moves the squeegee 16c in the X direction to spread the metal powder 32 on the modeling plate 22. At this time, the metal powder 32 is spread on the modeling plate 22 to a thickness equivalent to ΔZ. As a result, a powder layer 32a is formed on the modeling plate 22. In addition, excess metal powder 32 is collected in the collection box 21.

[0034] (Preheating process) Next, the beam irradiation device 14 operates based on a control command given from the control unit 50 to preheat the powder layer 32a on the modeling plate 22 (step S4). In this preheating step S4, the powder layer 32a is preheated to pre-sinter the metal powder 32. The preheating step S4 is performed before the main sintering step S5, which will be described later. In this way, the preheating step performed before the main sintering step is also called a powder heat step. In FIG. 1, the reference character E1 indicates an unsintered region where the unsintered metal powder 32 exists, and the reference character E2 indicates a pre-sintered region where the pre-sintered metal powder 32 exists.

[0035] (Main sintering process) Next, the beam irradiation device 14 operates based on a control command given from the control unit 50, thereby melting and solidifying the metal powder 32 to perform main sintering (step S5). In step S5, the metal powder 32 provisionally sintered as described above is melted and solidified by irradiation with the electron beam 15, thereby final sintering the metal powder 32 as a provisionally sintered body. In step S5, the control unit 50 sets the cross-sectional shape of each layer cut out from the three-dimensional shape data of the target object 38 as a melting target area, and controls the beam irradiation device 14 according to the molding data associated with the cross-sectional shape. As a result, the melting target area represented by the two-dimensional cross-sectional shape of the metal powder 32 on the molding plate 22 is melted by irradiation with the electron beam 15. The metal powder 32 melted by irradiation with the electron beam 15 is solidified by natural cooling after the electron beam 15 has passed. As a result, the first layer of the molded object is formed.

[0036] (Plate lowering process) Next, the plate moving device 26 operates based on a control command given from the control unit 50 to lower the modeling plate 22 by a predetermined amount (ΔZ) (step S6). In step S6, the plate moving device 26 lowers the modeling plate 22 and the inner base 24 by ΔZ.

[0037] (First pre-heating step) Next, the beam irradiation device 14 preheats the powder layer 32a on the modeling plate 22 based on a control command given by the control unit 50 (step S7). In this first preheating step S7, the powder layer 32a, which has been subjected to the main sintering step in the previous layer, is preheated in preparation for spreading the metal powder 32 of the next layer. As a result, the powder layer 32a is heated to a degree that the metal powder 32 of the next layer is presintered. This preheating step S7 may be performed after the main sintering step S5 described above, or after the main sintering step S10 described below. In this way, the preheating step performed after the main sintering step is also called an afterheating step.

[0038] (Powder coating process) Next, the powder coating device 16 operates based on a control command given from the control unit 50 to coat the metal powder 32 onto the shaping plate 22 to form a powder layer 32a (step S8). In step S8, the powder coating device 16 operates in the same manner as in step S3 above. As a result, on the shaping plate 22, the second layer of metal powder 32 is spread over the sintered body formed by the first layer of metal powder 32, forming a powder layer 32a.

[0039] (Second pre-heating process) Next, the beam irradiation device 14 operates based on a control command given from the control unit 50 to preheat the metal powder 32 forming the second powder layer 32a (step S9). This preheating step S9 is performed before the main sintering step 10 described below. Therefore, this preheating step S9 is also called a powder heat step. In step S9, the beam irradiation device 14 operates in the same manner as in step S4 above, whereby the metal powder 32 forming the second powder layer 32a is pre-sintered.

[0040] (Main sintering process) Next, the beam irradiation device 14 operates based on a control command given from the control unit 50, thereby melting and solidifying the metal powder 32 forming the second powder layer 32a to perform main sintering (step S10). In step S10, the beam irradiation device 14 operates in the same manner as in step S5 above, thereby forming a second-layer object.

[0041] Next, the control unit 50 checks whether or not the formation of the target object 38 has been completed (Step S11). If the control unit 50 determines that the formation of the object 38 has not been completed, the process returns to Step S6. As a result, the control unit 50 repeats the processes of Steps S6 to S10 for each layer from the third layer onwards. If the control unit 50 determines that the formation of the object 38 has been completed, the process ends at that point. By the above-described three-dimensional additive manufacturing process, the desired object 38 is obtained.

[0042] <Configuration of 3D additive manufacturing system> FIG. 4 is a diagram showing an example of the configuration of a three-dimensional additive manufacturing system according to the first embodiment of the present invention. As shown in FIG. 4, the three-dimensional additive manufacturing system 100 includes a three-dimensional additive manufacturing device 10 and a modeling data creation device 30. The configuration and operation of the three-dimensional additive manufacturing device 10 are as described above. The modeling data creation device 30 creates modeling data using three-dimensional shape data of an object generated by a three-dimensional CAD or the like. The modeling data created by the modeling data creation device 30 is recorded, for example, in a portable recording medium, and the modeling data is provided to the three-dimensional additive manufacturing device 10 using this recording medium. The provided modeling data is read into a control unit 50 of the three-dimensional additive manufacturing device 10. The control unit 50 controls the operation of the three-dimensional additive manufacturing device 10 based on the modeling data read from the recording medium. As a result, the three-dimensional additive manufacturing device 10 models an object according to the modeling data created by the modeling data creation device 30.

[0043] The method of providing the modeling data from the modeling data creation device 30 to the three-dimensional additive manufacturing device 10 is not limited to the method using the portable recording medium described above. For example, the modeling data created by the modeling data creation device 30 may be provided to the three-dimensional additive manufacturing device 10 via a cable or a network. In addition, the three-dimensional additive manufacturing device 10 may be configured to have each of the functions of the modeling data creation device 30 (see FIG. 5).

[0044] The modeling data created by the modeling data creation device 30 includes modeling data for controlling the operations of the electron gun 141, the convergent lens 142, and the deflection device 143, modeling data for controlling the powder coating device 16, and modeling data for controlling the plate moving device 26. However, in this specification, the creation of modeling data for controlling the operation of the beam irradiation device 14 will be described, and a description of the creation of other modeling data will be omitted.

[0045] <Configuration of modeling data creation device> FIG. 5 is a block diagram showing an example of the configuration of a modeling data creating apparatus according to the first embodiment of the present invention. 5, the modeling data creation device 30 includes an import unit 301, a cut-out unit 302, a modeling data generation unit 303, and an output unit 304. Although not shown, the modeling data creation device 30 is configured by a computer including a processor such as a CPU, and storage units such as a ROM, a RAM, a HDD, and an SSD. Each function of the modeling data creation device 30 is realized by the processor reading a program written in advance in the ROM into the RAM and executing the program.

[0046] The import unit 301 imports three-dimensional shape data necessary for creating modeling data. This three-dimensional shape data is data that specifies the three-dimensional shape of an article generated by a three-dimensional CAD or the like.

[0047] The cut-out unit 302 cuts out the cross-sectional shape of each layer at a predetermined thickness from the three-dimensional shape data imported by the import unit 301. This cross-sectional shape is a two-dimensional cross-sectional shape representing the shape of the region to be melted by irradiation of a beam (electron beam 15 in this embodiment) in each powder layer 32a, i.e., the shape of the melting target region. The cross-sectional shape cut out by the cut-out unit 302 is a shape represented by one or more closed lines.

[0048] The modeling data generating unit 303 generates modeling data by applying predetermined modeling conditions to the cross-sectional shape cut out by the cutting unit 302. This modeling data corresponds to modeling data (operation sequence program) for the control unit 50 to control the operation of the beam irradiation device 14 in the sintering steps S5 and S10 (FIG. 3). The modeling conditions include beam scanning conditions and beam irradiation conditions. The beam scanning conditions are conditions that are applied when the surface of the powder layer 32a is scanned with the electron beam 15 by the deflection device 143. The beam irradiation conditions are conditions related to the electron gun 141 and the converging lens 142 that are applied when the electron beam 15 is irradiated to the surface of the powder layer 32a. There are various beam scanning conditions, and there are also various beam irradiation conditions. Specific examples of the beam scanning conditions and the beam irradiation conditions are described below.

[0049] The beam scanning conditions include the beam scanning method, the distance between adjacent scanning lines (scanning line interval), scanning speed, etc. The beam scanning methods include raster scanning, tree-ring-shaped vector scanning, random scanning, etc. Raster scanning is a method of generating parallel scanning lines and scanning the beam along the generated scanning lines. Raster scanning includes one-way raster scanning and alternating direction raster scanning. Tree-ring-shaped vector scanning is a method of generating scanning lines a certain distance inward from the contour line that forms the cross-sectional shape and scanning the beam along the generated scanning lines. There are other scanning methods for vector scanning besides tree-ring-shaped vector scanning. Random scanning is a method of randomly scanning the area of ​​the cross-sectional shape with the beam. When the surface of the powder layer 32a is scanned with the electron beam 15, the center of the spot of the electron beam 15 moves on the scanning line.

[0050] On the other hand, the beam irradiation conditions include the amount of current of the charged particle beam controlled by the electron gun 141, the beam size on the printing surface controlled by the convergent lens 142, and the like. The amount of current of the charged particle beam corresponds to the amount of beam current. In this embodiment, an electron beam 15 is used as the charged particle beam. Therefore, the amount of current of the electron beam 15 corresponds to the amount of current of the charged particle beam. Also, the size (spot size) of the electron beam 15 on the printing surface 32b corresponds to the beam size on the printing surface. When the beam irradiated to the surface of the powder layer 32a is a laser beam, the beam irradiation conditions include the intensity (beam intensity) of the laser beam, the beam size on the printing surface, and the like.

[0051] Furthermore, the modeling data generating unit 303 generates a scanning line for scanning the surface of the powder layer 32a with the electron beam 15 in the above-mentioned main sintering process. That is, the modeling data generated by the modeling data generating unit 303 includes data of the scanning line. The scanning line is a line that defines the movement path (scanning path) of the electron beam 15 when melting the cross-sectional shape region (melting target region) of each layer by irradiating the electron beam 15. That is, in the cross-sectional shape region, the electron beam 15 moves along the scanning line.

[0052] Regarding the generation of scanning lines, the modeling data generation unit 303 generates a plurality of scanning lines in a region of a cross-sectional shape cut out by the cut-out unit 302 using a predetermined beam scanning method, and generates correction scanning lines in a portion where the arrangement of the scanning lines becomes sparse and / or dense. The process of generating scanning lines by the modeling data generation unit 303 will be described in detail later.

[0053] The output unit 304 outputs the modeling data generated by the modeling data generation unit 303 to an electronic file. The modeling data output to the electronic file is provided to the three-dimensional additive manufacturing apparatus 10 by the above-mentioned method (for example, a method using a portable recording medium). When an article to be modeled is to be modeled by dividing it into, for example, 100 layers, modeling data for 100 layers is provided to the three-dimensional additive manufacturing apparatus 10. The control unit 50 of the three-dimensional additive manufacturing apparatus 10 sequentially controls the operation of the entire three-dimensional additive manufacturing apparatus 10 in accordance with the modeling data provided from the modeling data creation device 30.

[0054] <Processing procedure of modeling data creation device> FIG. 6 is a flowchart showing an example of a processing procedure (modeling data creating method) of the modeling data creating apparatus according to the first embodiment of the present invention. First, the import unit 301 imports three-dimensional shape data (step S31). Next, the cutout unit 302 cuts out the cross-sectional shape of one layer from the three-dimensional shape data (step S32). One layer includes one or more cross-sectional shapes.

[0055] Next, the modeling data generation unit 303 generates modeling data by applying predetermined modeling conditions to the cross-sectional shape cut out by the cut-out unit 302 (step S33). The modeling data generation unit 303 generates scanning lines in step S33.

[0056] Next, the output unit 305 outputs the shaping data generated by the shaping data generation unit 303 in step S33 to an electronic file (step S34). Next, the modeling data creation device 30 determines whether or not there is a next layer (step S35). The determination in step S35 is performed, for example, by the cut-out unit 302. If there is a next layer (YES in step S35), the process returns to step S32, and if there is no next layer (NO in step S35), the process ends.

[0057] <Scanning line generation process> Next, the scanning line generation process performed by the modeling data generation unit 303 will be described in detail with reference to FIGS. First, as shown in FIG. 7, the modeling data generating unit 303 generates a plurality of scanning lines 41 to 47 in the area of ​​the cross-sectional shape 40 cut out by the cut-out unit 302 using a predetermined beam scanning method. In the first embodiment, the modeling data generating unit 303 generates a plurality of scanning lines in the area of ​​the cross-sectional shape 40 using a tree-ring-shaped vector scanning method. As described above, the tree-ring-shaped vector scanning method (hereinafter, also simply referred to as the "vector scanning method") is a method of generating scanning lines at a certain distance inward from a contour line forming a cross-sectional shape. For this reason, the plurality of scanning lines generated by the vector scanning method are concentric scanning lines. As shown in FIG. 7, the plurality of scanning lines generated by the vector scanning method may include scanning lines 41, 42, and 43 generated along the contour line of the cross-sectional shape 40 in a shape similar to the contour line, as well as scanning lines 44, 45, 46, and 47 generated in an island shape in a shape different from the contour line of the cross-sectional shape 40. The plurality of scanning lines 41 to 47 correspond to the concentric scanning lines generated by the tree-ring-shaped vector scanning method.

[0058] As described above, when a plurality of scanning lines 41 to 47 are generated in the region of the cross-sectional shape 40 by the vector scanning method, as shown in FIG. 7, there may be generated portions P11 and P12 where the scanning lines are sparsely arranged compared to other portions, and portions P13 and P14 where the scanning lines are densely arranged compared to other portions. The above-mentioned other portions are, for example, the portion indicated by the symbol P10 in FIG. 7. For convenience, in FIG. 7, two portions where the scanning lines are sparsely arranged and two portions where the scanning lines are densely arranged are shown, but there are other such portions. In the portions P11 and P12 where the scanning lines are sparsely arranged, the scanning lines are too far apart. For this reason, when the cross-sectional shape 40, which is the melting target region in this sintering process, is scanned with a beam along the scanning lines, melting defects due to insufficient melting are likely to occur in the portions P11 and P12 where the scanning lines are sparsely arranged. The melting defects due to insufficient melting are defects that occur due to insufficient beam irradiation energy. On the other hand, in the portions P13 and P14 where the scanning lines are densely arranged, the scanning lines are too close to each other. Therefore, when the cross-sectional shape 40 that is the melting target region in the main sintering process is scanned along the scanning lines with a beam, melting defects due to excessive melting are likely to occur in the parts P13 and P14 where the scanning lines are densely arranged. Melting defects due to excessive melting are defects that occur due to an excessive amount of beam irradiation energy.

[0059] Therefore, the modeling data generating unit 303 performs processing for generating correction scanning lines in the parts P11 and P12 where the arrangement of the scanning lines is sparse, and in the parts P13 and P14 where the arrangement of the scanning lines is dense. The correction scanning lines are generated to suppress the occurrence of the melting defects described above. The modeling data generating unit 303 generates the correction scanning lines by morphological graphic processing described below. In this morphological graphic processing, the interval between the scanning lines applied when generating the multiple scanning lines 41 to 47 in the tree-ring-like vector scanning method described above is set to d (μm) (see FIG. 7). The part indicated by the reference symbol P10 in FIG. 7 corresponds to the part of the scanning lines arranged at the interval d. The interval d between the scanning lines is the interval (the distance between the scanning lines) defined by the parallel parts of two adjacent scanning lines (for example, the scanning lines 41 and 42). The value of the interval d between the scanning lines is designated (input) in advance by the user, for example, together with the beam size on the modeling surface.

[0060] In addition, in the morphological graphic processing, the constants a, b, and ε defined below are used. Constant a=1 / 3 Constant b=√2 The constant ε is a value that is larger than the calculation rounding error expected to occur in a computer and smaller than the modeling dimension reproduction accuracy of the 3D additive manufacturing apparatus 10. The constant ε is a value determined on the CAM software program, and is expressed in μm.

[0061] In this embodiment, it is assumed that the cross-sectional shape 40 cut out by the cut-out unit 302 is a polygon, and that this polygon is a figure expressed by, for example, specifying the coordinates of the vertices as numerical values. It is assumed that the polygon 1A shown in FIG. 8 is a figure represented by a scanning line that is generated n-th from the outermost periphery of the cross-sectional shape 40 cut out by the cut-out unit 302 and that is determined by the modeling data generating unit 303 as the n-th tree-ring-shaped scanning line (not including the correction scanning line) through morphological figure processing. Specifically, the polygon 1A is a figure generated in the following procedure. First, the modeling data generating unit 303 generates a figure obtained by enlarging the figure represented by the above-mentioned scanning line 41 by a predetermined amount as a figure represented by a fictitious scanning line that is not actually output. The predetermined amount is selected as a value as close as possible to the interval d of the scanning lines (see FIG. 7) within a range in which self-intersection does not occur even if the figure represented by the scanning line 41 is enlarged by the predetermined amount. Next, the modeling data generating unit 303 performs morphological graphic processing (described in detail later) on the figure represented by the imaginary scanning line as the first processing target, and determines the tree-ring-shaped scanning line generated by the graphic processing and the corresponding correction scanning line as the first scanning line and correction scanning. At this time, if a part of the correction scanning line generated by performing the morphological graphic processing protrudes outside the scanning line 41, the modeling data generating unit 303 deletes the protruding part of the correction scanning line. The polygon 1A shown in FIG. 8 is a figure represented by the tree-ring-shaped scanning line determined as the first scanning line by the modeling data generating unit 303. The polygon 1A has inward acute angle vertices 48a, 48b and outward acute angle vertices 49a, 49b.

[0062] First, as shown in FIG. 9, the modeling data generating unit 303 generates a polygon 1B (a figure shown by a dashed line in FIG. 9) by reducing (shrinking) the polygon 1A by a dimension of (1+a)×d. In this reduction process, the movement amount Ls of the inward acute angle vertices 48a, 48b described above is limited so that each of the movement amounts Ls of the acute angle vertices 48a, 48b is equal to or less than a×d×b. In other words, the portions of the acute angle vertices 48a, 48b whose movement amount Ls exceeds a×d×b due to the reduction process are cut off. As a result, even if the tip of the inward acute angle vertex 48a in the polygon A1 is sharp, the angle θ of the inward acute angle vertex of the polygon 1B can be made obtuse. On the other hand, there is no need to limit the movement amount of the outward acute angle vertices 49a, 49b. For this reason, the outwardly facing acute apexes 49a, 49b of the polygon 1A may have a pointed shape, as in the polygon 1B shown in FIG.

[0063] Next, as shown in Fig. 10, the printing data generating unit 303 generates polygon 1C (a figure indicated by a dashed line in Fig. 10) by enlarging (expanding) polygon 1B by a dimension of 2xaxd. In this enlarging process, for the above-mentioned outward acute vertices 49a and 49b, the movement amount Ls of the outward acute vertices in polygon 1B is limited so that both are equal to or less than axdxb. This makes it possible to make the angle θ of the outward acute vertex of polygon 1C an obtuse angle. On the other hand, there is no need to limit the movement amount of the inward acute vertices in polygon 1B.

[0064] Next, the printing data generation unit 303 generates polygon 1D (a figure indicated by a two-dot chain line in FIG. 11) by reducing (shrinking) polygon 1C by a dimension of a×d, as shown in FIG. 11. The printing data generation unit 303 determines a single closed line expressing the shape (contour) of this polygon 1D as the (n+1)th tree-ring-shaped scanning line.

[0065] Next, as shown in FIG. 12, the printing data generating unit 303 reduces the polygon 1A by a dimension of (1-a)×d to generate a polygon 1E (a shape indicated by a dashed line in FIG. 12).

[0066] Next, as shown in FIG. 13, the printing data generation unit 303 enlarges the polygon 1D shown in FIG. 11 by a dimension of a×d+ε to generate a polygon 1F (a shape indicated by a dashed line in FIG. 13).

[0067] Next, as shown in FIG. 14, the shaping data generating unit 303 generates (extracts) 0 or more polygons 1G(i) by deleting the area of ​​polygon 1F shown in FIG. 13 from the area of ​​polygon 1E shown in FIG. 12. The subscript i in polygon 1G(i) is an integer equal to or greater than 1, and is a value that depends on the shape of the original figure (see FIG. 8). In this way, when the number of polygons 1G generated by the shaping data generating unit 303 is m (the maximum value of i is m), the shaping data generating unit 303 generates polygons 1G(1), 1G(2), ..., 1G(m). The polygons 1G(i) are locations where melting defects (melting defects due to insufficient melting, melting defects due to excessive melting, etc.) are predicted to occur when the beam is scanned along the multiple scanning lines 41 to 47 shown in FIG. 7. That is, the printing data generation unit 303 generates a polygon 1G(i) and thereby identifies the location of the polygon 1G(i) as a location where the melting defect is predicted to occur. Fig. 14 shows the case where two polygons 1G(1) and 1G(2) are generated, that is, the case where m = 2.

[0068] Next, as shown in FIG. 15, the modeling data generating unit 303 generates a predetermined line 1H(i,j) in the area of ​​each polygon 1G(1), 1G(2), ..., 1G(m) for the polygon 1G(i). The predetermined line 1H(i,j) is a line generated as a correction scanning line. In other words, the modeling data generating unit 303 generates a correction scanning line in a location where a melting defect is predicted to occur when a beam is scanned along the multiple scanning lines 41 to 47 shown in FIG. 7. The subscript i in the predetermined line 1H(i,j) is the same as the subscript i in the polygon 1G(i) described above. The subscript j in the predetermined line 1H(i,j) is a natural number indicating the number of predetermined lines 1H generated in the area of ​​one polygon 1G(i). That is, j=1, ..., k. The maximum value k of j takes a different value of 1 or more depending on the shape of the polygon 1G(i). 15 shows a case where a predetermined line 1H(1,1) is generated in the area of ​​polygon 1G(1), and a predetermined line 1H(2,1) is generated in the area of ​​polygon 1G(2). The predetermined line 1H(i,j) is preferably a straight line, a broken line, or a branched line that serves as the midline of polygon 1G(i).

[0069] The predetermined line 1H(i,j) is a line that can be scanned in one direction from one end of the predetermined line 1H(i,j) to the other end. As shown in FIG. 7, each of the multiple scanning lines 41 to 47 generated by the tree-ring-like vector scanning method is represented by a single closed line, but the predetermined line 1H(i,j) is an unclosed line. Specifically, the predetermined line 1H(i,j) is at least one of a straight line, a broken line, and a branched line. If the predetermined line 1H(i,j) does not branch, the value of j is 1. If the predetermined line 1H(i,j) branches, the value of j is 2 or more.

[0070] 16 shows a case where the predetermined line 1H(i,j) generated in the area of ​​polygon 1G(i) is a straight line. The predetermined line 1H(i,j) is a single straight line 1H(i,1) that runs from one end of polygon 1G(i) in the longitudinal direction to the other end of polygon 1G(i) and passes through the center of polygon 1G(i) in the lateral direction.

[0071] 17 shows a case where a predetermined line 1H(i,j) generated in the area of ​​a polygon 1G(i) is a broken line. The predetermined line 1H(i,j) passes through the center of the short side of the polygon 1G(i) from one end of the long side of the polygon 1G(i) to the other end, and becomes a single broken line 1H(i,1) that is bent halfway.

[0072] FIG. 18 shows a case where a predetermined line 1H(i,j) generated in the area of ​​a polygon 1G(i) is a branched line. The predetermined line 1H(i,j) is a branched line having a line 1H(i,1) that bends from one end of the polygon 1G(i) to the other end, and a line 1H(i,2) that branches off from the middle of the line 1H(i,1). The lines 1H(i,1) and 1H(i,2) are separated from each other at part P in FIG. 18. By separating the lines 1H(i,1) and 1H(i,2) at part P, it is possible to prevent the beam irradiation energy from being excessively injected near part P.

[0073] In this way, the printing data generation unit 303 generates a predetermined line 1H(i,j) in the area of ​​each polygon 1G(i). In other words, the printing data generation unit 303 generates a predetermined line 1H(i,j) for each polygon 1G(i). Then, the printing data generation unit 303 determines all the generated predetermined lines 1H(i,j) as correction scanning lines corresponding to the (n+1)th tree-ring-like scanning line.

[0074] As a result, the modeling data generating unit 303 generates an n+1-th tree-ring-shaped scanning line 51 and corrected scanning lines 52a and 52b corresponding to the scanning line 51, as shown in FIG. 19. The scanning line 51 is a line representing the polygon 1D shown in FIG. 11. The corrected scanning line 52a is a line corresponding to the predetermined line 1H(1,1) shown in FIG. 15. The corrected scanning line 52b is a line corresponding to the predetermined line 1H(1,2) shown in FIG. 15. The scanning line 51 is a single closed line, and the corrected scanning lines 52a and 52b are both open lines.

[0075] The shaping data generating unit 303 executes the morphological graphic processing described above with reference to Figs. 8 to 19 for each polygon represented by each of the scanning lines 41 to 47 shown in Fig. 7. The shaping data generating unit 303 starts the processing from a polygon representing the contour line of the cross-sectional shape of the shaping object, or a polygon expanded or contracted by a certain distance from the contour line. Then, the morphological graphic processing is repeated for all polygons represented by the scanning lines 41 to 47. As a result, the shaping data generating unit 303 generates a plurality of tree-ring-shaped scanning lines 61 to 66 and a plurality of corrected scanning lines 71, 72, 73, 74, 75, 76, 77, ... in the area of ​​the cross-sectional shape 40 cut out from the three-dimensional shape data of the article, as shown in Fig. 20.

[0076] 7 correspond to the scanning lines 61 to 66 and the correction scanning line shown in FIG. 20 as follows: the scanning line 41 corresponds to the scanning line 61, the correction scanning line 76, and the correction scanning line 78, the scanning line 42 corresponds to the scanning line 62, the correction scanning line 77, and the correction scanning line 79, the scanning line 43 corresponds to the scanning line 63, the correction scanning line 72, and the correction scanning line 80, the scanning line 44 corresponds to the scanning line 64 and the correction scanning line 71, the scanning line 45 corresponds to the scanning line 65, the correction scanning line 81, and the correction scanning line 82, and the scanning line 46 corresponds to the scanning line 66, the correction scanning line 74, and the correction scanning line 83.

[0077] 7 and 20, a correction scanning line 71 is added to a portion P11 where the scanning lines are sparsely arranged, and a correction scanning line 77 is added to a portion P12 where the scanning lines are sparsely arranged. In contrast, in a portion P13 where the scanning lines are densely arranged, the scanning line 47 is replaced with a correction scanning line 75, and in a portion P14 where the scanning lines are densely arranged, a part (pointed part) of the scanning line 41 is replaced with a correction scanning line 76. In other words, the shaping data generation unit 303 adds a correction scanning line to a portion where the scanning lines are sparsely arranged, and replaces a scanning line with a correction scanning line in a portion where the scanning lines are densely arranged. This also applies to portions not marked in FIGS. 7 and 20 (sparse portions and dense portions).

[0078] As a result, when the modeling data generating unit 303 of the modeling data creating device 30 generates modeling data, the scanning lines that may cause melting defects can be suppressed from being too far apart or too close to each other, and the variation in density of the scanning lines can be reduced. In addition, in this sintering process, the control unit 50 controls the beam irradiation device 14 according to the modeling data previously generated by the modeling data generating unit 303, so that the electron beam 15 is scanned along the above-mentioned multiple scanning lines 61 to 66 and the multiple corrective scanning lines 71, 72, 73, 74, 75, 76, 77, ..., and an article is modeled. Therefore, in the three-dimensional additive manufacturing device 10, when the cross-sectional shape of each layer is melted by irradiation (scanning) with the electron beam 15 to form an article, the occurrence of melting defects due to insufficient melting or excessive melting can be suppressed.

[0079] In addition, the order in which the beam irradiation device 14 of the three-dimensional additive manufacturing device 10 scans the multiple scanning lines (61 to 66) and multiple correction scanning lines (71, 72, 73, 74, 75, 76, 77, ...) generated by the modeling data generation unit 303 of the modeling data creation device 30 with the electron beam 15 can be set arbitrarily.

[0080] For example, the multiple scanning lines (61 to 66) may be beam scanned from the outer scanning lines first, or from the inner scanning lines first. Also, adjacent scanning lines (61 to 66) may be beam scanned in order, or beam scanning may be repeated while skipping several scanning lines. Also, the multiple scanning lines (61 to 66) may be beam scanned in a completely random order. Regardless of the order in which the multiple scanning lines (61 to 66) are beam scanned, all of the scanning lines (61 to 66) need to be beam scanned.

[0081] Furthermore, for the multiple correction scanning lines (71, 72, 73, 74, 75, 76, 77, ...), each time one tree-ring shaped scanning line is beam-scanned, the correction scanning line associated with that scanning line may be beam-scanned. Furthermore, the multiple correction scanning lines (71, 72, 73, 74, 75, 76, 77, ...) may be beam-scanned before the multiple tree-ring shaped scanning lines (61 to 66) are beam-scanned or after the multiple tree-ring shaped scanning lines (61 to 66) are beam-scanned.

[0082] In addition, the same or different modeling conditions may be applied when scanning the multiple scanning lines (61 to 66) with a beam and when scanning the multiple correction scanning lines (71, 72, 73, 74, 75, 76, 77, ...) with a beam. When applying different modeling conditions, at least one of the scanning speed, the beam size on the modeling surface, the beam current, and the beam intensity may be different.

[0083] <Second embodiment> Next, a second embodiment of the present invention will be described. The configuration and operation of the three-dimensional additive manufacturing apparatus 10 according to the second embodiment of the present invention, and the configuration of the three-dimensional additive manufacturing system 100 are the same as those of the first embodiment described above. However, in the second embodiment of the present invention, the content of the scanning line generation process (morphological graphic processing) performed by the modeling data generation unit 303 of the modeling data creation device 30 is different.

[0084] <Scanning line generation process> First, the modeling data generating unit 303 generates a plurality of scanning lines in a region of the cross-sectional shape cut out by the cutting out unit 302 by a predetermined beam scanning method. In the above-mentioned first embodiment, a tree-ring-shaped vector scanning method is adopted as the predetermined beam scanning method, but in the second embodiment, a raster scanning method is adopted. FIG. 21 shows an example of a cross-sectional shape to be melted by raster scanning. The figure representing the cross-sectional shape shown in FIG. 21 is a polygon 2A.

[0085] As shown in FIG. 22, the modeling data generating unit 303 generates a plurality of scanning lines 2B(j) in the region of the cross-sectional shape (polygon 2A) shown in FIG. 21 by the raster scanning method. The subscript j in the scanning line 2B(j) is a natural number. When the number of scanning lines generated by the modeling data generating unit 303 in the region of the cross-sectional shape is n, j=1, 2, 3, ..., n. The plurality of scanning lines 2B(j) are parallel to each other, that is, parallel scanning lines (hereinafter, also referred to as "raster scanning lines"). In addition, the modeling data generating unit 303 generates the plurality of scanning lines 2B(j) at a predetermined interval p (μm). The interval p corresponds to the distance between adjacent scanning lines in a direction perpendicular to the scanning line 2B(j) (the vertical direction in FIG. 22). The value of the interval p of the scanning lines is designated (input) in advance by the user, for example, together with the beam size on the modeling surface. A method of generating the multiple scanning lines 2B(j) may be, for example, to generate them as a logical product of a raster scanning line that fully covers the polygon 2A and the area of ​​the polygon 2A.

[0086] Here, as shown in FIG. 22, when a plurality of scanning lines 2B(j) are generated in a region of a cross-sectional shape represented by a polygon 2A by a raster scanning method, there are some parts where the arrangement of the scanning lines is sparser than other parts. Specifically, in the contour parts P21, P22, P23, and P24 of the contour of the cross-sectional shape represented by the polygon 2A that are inclined with respect to the scanning lines 2B(j), the arrangement of the scanning lines 2B(j) is sparser than other parts (for example, the part indicated by P20). The reason why the arrangement of the scanning lines 2B(j) is sparse in the inclined contour parts P21, P22, P23, and P24 is because the ends of each scanning line 2B(j) are shifted in the left-right direction in FIG. 22 due to the inclination of the contour of the cross-sectional shape (polygon 2A), and as a result, the distance between the ends of the scanning lines 2B(j) becomes longer than other parts. The other parts are, for example, the part indicated by the symbol P20 in FIG. 22. The portion indicated by reference symbol P20 is a portion perpendicular to the scanning lines 2B(j). In the portion indicated by reference symbol P20, the ends of each scanning line 2B(j) are positioned substantially on the same line, without being shifted in the left-right direction of FIG.

[0087] When the cross-sectional shape (polygon 2A) that is the region to be melted in this sintering process is scanned with a beam along multiple scanning lines 2B(j), the above-mentioned contour portions P21, P22, P23, and P24 end up with stepped irregularities, for example, as shown in FIG. 24. If such irregularities appear on the surface of the molded object, it is necessary to remove the irregularities by subjecting the molded object obtained by additive manufacturing to post-processing. In particular, if the molded object is made of a difficult-to-cut material, the time required for post-processing increases, which reduces production efficiency.

[0088] Therefore, the modeling data generating unit 303 performs processing to generate corrective scanning lines for the contour portions P21, P22, P23, and P24 where the arrangement of scanning lines is sparse. The corrective scanning lines are generated to reduce the unevenness of the surface and to suppress the occurrence of melting defects. The modeling data generating unit 303 generates the corrective scanning lines by morphological graphic processing described below.

[0089] First, the modeling data generating unit 303 estimates (assumes) the range of melting and solidification when a beam is scanned along each of the plurality of scanning lines 2B(j) generated as described above by calculation, simulation, etc. Here, as an example, as shown in FIG. 23, the range of melting and solidification when a beam is scanned along the scanning line 2B(1) (hereinafter also referred to as the "melting range") is set to the range of a rectangle 2C(1), which is a polygon having appropriate widths in the direction of travel of the scanning line 2B(1) and in the direction perpendicular thereto. In this sintering process, the spot of the electron beam 15 moves on the scanning line 2B(1). Therefore, the modeling data generating unit 303 assumes the range of the rectangle 2C(1) centered on the scanning line 2B(1) as the range of melting and solidification. In addition, the modeling data generating unit 303 assumes that the length L of the rectangle 2C(1) is longer than the length of the scanning line 2B(1). The modeling data generating unit 303 also assumes a width W of a rectangle 2C(1) centered on the position of the scanning line 2B(1). Fig. 23 shows, as an example, an example in which the length L of the rectangle 2C(1) is assumed to be 0.5 times the interval p of the scanning lines (see Fig. 22), i.e., 0.5p, longer at each end than the length of the scanning line 2B(1). Fig. 23 also shows, as an example, an example in which the width W of the rectangle 2C(1) is assumed to be 1.2 times the interval p of the scanning lines, i.e., 1.2p.

[0090] In this way, the modeling data generating unit 303 assumes the melting range by using a constant multiple of the interval p of the scanning lines. It is preferable to define the melting range separately in the length direction of the scanning line 2B(1) and in the direction perpendicular to the length direction. The reason is that when the electron beam 15 is scanned along the raster scanning line, the amount of energy injected by the irradiation of the electron beam 15 differs between the vicinity of the end of the length direction of the raster scanning line and the other parts. Specifically, the cumulative irradiation time of the electron beam 15 is shorter at the end of the length direction of the raster scanning line than the other parts, and the amount of energy injected is accordingly smaller. Therefore, in order to assume the melting range more accurately, it is reasonable to make the constant applied to the calculation of the length L of the rectangle 2C(1) smaller than the constant applied to the calculation of the width W of the rectangle 2C(1).

[0091] The printing data generation unit 303 obtains rectangles 2C(2), 2C(3), ..., 2C(n) indicating the expected melting range for the other scanning lines 2B(2), 2B(3), ..., 2B(n) in the same manner as in the case of the above-mentioned scanning line 2B(1). In addition, the printing data generation unit 303 generates a polygon 2C (a figure indicated by a dashed line in FIG. 24) as shown in FIG. 24 by combining (fusing) all the rectangles 2C(1), 2C(2), 2C(3), ..., 2C(n) indicating the expected melting range.

[0092] Next, as shown in FIG. 25, the shaping data generating unit 303 generates (extracts) the remaining area obtained by removing the area of ​​the polygon 2C from the area of ​​the polygon 2A as 0 or more polygons 2D(i). The subscript i in the polygon 2D(i) is an integer equal to or greater than 1. In this way, when the number of polygons 2D generated by the shaping data generating unit 303 is m (the maximum value of i is m), the shaping data generating unit 303 generates polygons 2D(1), 2D(2), ..., 2D(m). In other words, the value of m indicates the number of polygons 2D(i) generated by the shaping data generating unit 303. The polygons 2D(1), 2D(2), ..., 2D(m) are locations where melting defects (such as melting defects due to insufficient melting) or recesses are expected to occur when the beam is scanned along the scanning line 2B(j) shown in FIG. 22 above. That is, the shaping data generating unit 303 generates a polygon 2D(i) and identifies the location of the polygon 2D(i) as a location where the melting defect or recess is expected to occur. In this case, the portion where each polygon 2D(1), 2D(2), ..., 2D(m) exists corresponds to the portion where the arrangement of the scanning lines 2B(j) becomes sparse in the oblique contour portions P21, P22, P23, and P24 shown in FIG. 22. In FIG. 25, only some of the polygons 2D(i) generated by the shaping data generating unit 303 are labeled. FIG. 26 is an enlarged view of the R portion in FIG. 25. If the shaping data generating unit 303 does not generate any polygon 2D(i), the shaping data generating unit 303 does not generate a correction scanning line.

[0093] On the other hand, when the shaping data generating unit 303 generates one or more polygons 2D(i), the shaping data generating unit 303 generates a predetermined line 2E(i) in the area of ​​each polygon 2D(i) as shown in FIG. 27. The predetermined line 2E(i) is a line generated as a correction scanning line. In other words, the shaping data generating unit 303 generates a correction scanning line in a location where a melting defect (such as a melting defect due to insufficient melting) or a recess is expected to occur when the beam is scanned along the scanning line 2B(j) shown in FIG. 22. The subscript i in the predetermined line 2E(i) is the same as the subscript i in the polygon 2D(i) described above. In other words, the minimum value of i is 0, and the maximum value of i is m. In this case, the value of m indicates the number of correction scanning lines generated by the shaping data generating unit 303. The predetermined line 2E(i) is a line that can be scanned in one direction from one end of the predetermined line 2E(i) to the other end. Also, the given line 2E(i) is an unclosed line.

[0094] FIG. 27 shows, as an example, a case where the printing data generating unit 303 generates a predetermined line 2E(1) in the area of ​​the polygon 2D(1). The predetermined line 2E(1) is a single broken line that passes through the center of the short side of the polygon 2D(1) from one end of the long side of the polygon 2D(1) to the other end and is bent halfway. However, the predetermined line 2E(1) may be a single straight line that passes through the center of the short side of the polygon 2D(1) from one end of the long side of the polygon 2D(1) to the other end. The printing data generating unit 303 generates predetermined lines 2E(2), 2E(3), ..., 2E(m) for the other polygons 2D(2), 2D(3), ..., 2D(m) in the same manner as for the polygon 2D(1). Then, the modeling data generation unit 303 determines all the generated predetermined lines 2E(i) as correction scanning lines corresponding to the cross-sectional shape of the polygon 2A.

[0095] As a result, the modeling data generating unit 303 generates a plurality of scanning lines 2B(j) and a plurality of corrected scanning lines 2E(i) as shown in FIG. 28. The plurality of scanning lines 2B(j) are parallel scanning lines generated by the raster scanning method as shown in FIG. 22. As can be seen from FIG. 28, the corrected scanning line 2E(i) is generated between adjacent scanning lines 2B(j) in a direction perpendicular to the scanning line 2B(j) (the vertical direction in FIG. 28). To explain this specifically by taking the corrected scanning line 2E(1) as an example, the corrected scanning line 2E(1) is generated between adjacent scanning lines 2B(12) and 2B(13) in the vertical direction in FIG. 28.

[0096] As a result, when the modeling data generating unit 303 of the modeling data creating device 30 generates modeling data, the excessive separation of the scanning lines that may cause melting defects or recesses can be suppressed, and the variation in density of the scanning lines can be reduced. In addition, in this sintering process, the control unit 50 controls the beam irradiation device 14 according to the modeling data previously generated by the modeling data generating unit 303, so that the electron beam 15 is scanned along the multiple scanning lines 2B(j) and the multiple corrected scanning lines 2E(i) to model an article. Therefore, in the three-dimensional additive manufacturing device 10, when the cross-sectional shape of each layer is melted by irradiation (scanning) with the electron beam 15 to form an article, the occurrence of melting defects and recesses due to insufficient melting can be suppressed. Therefore, the occurrence of unevenness in the above-mentioned contour portions P21, P22, P23, and P24 (see FIG. 22) can be suppressed.

[0097] In addition, the order in which the beam irradiation device 14 of the three-dimensional additive manufacturing device 10 scans the multiple scanning lines 2B(j) and multiple correction scanning lines 2E(i) generated by the modeling data generation unit 303 of the modeling data creation device 30 with the electron beam 15 can be set arbitrarily.

[0098] For example, the multiple scanning lines 2B(j) may be beam scanned starting from the scanning line 2B(1) on the upper side of FIG. 28, or may be beam scanned starting from the scanning line 2B(n) on the lower side of FIG. 28. Also, adjacent scanning lines in the vertical direction of FIG. 28 may be beam scanned in order, or beam scanning may be repeated while skipping several scanning lines. Also, the multiple scanning lines 2B(j) may be beam scanned in a completely random order. Whatever the order in which the multiple scanning lines 2B(j) are scanned, it is necessary to beam scan all of the multiple scanning lines 2B(j).

[0099] In addition, for the multiple correction scanning lines 2E(i), for example, each time one scanning line is beam-scanned, the correction scanning lines located between the scanning line and the adjacent scanning line may be beam-scanned. As a specific example, in FIG. 28, after the scanning line 2B(12) is beam-scanned, the correction scanning line 2E(1) is beam-scanned, and then the scanning line 2B(13) is beam-scanned, and then the correction scanning line 2E(2) is beam-scanned. In addition, the multiple correction scanning lines 2E(i) may be beam-scanned before or after the multiple scanning lines 2B(j) are beam-scanned.

[0100] In addition, the same or different modeling conditions may be applied when scanning multiple scanning lines 2B(j) with a beam and when scanning multiple corrective scanning lines 2E(i) with a beam. When applying different modeling conditions, it is sufficient that at least one of the scanning speed, the beam size on the modeling surface, the beam current amount, and the beam intensity is different.

[0101] Incidentally, as a technique for suppressing the occurrence of unevenness in the above-mentioned contour portions P21, P22, P23, and P24 (see FIG. 22), there is a technique for generating a contour scanning line along the contour line of the cross-sectional shape of the object, and performing beam scanning (vector scanning) along this contour scanning line. The contour scanning line is a line that represents a figure similar to the cross-sectional shape of the object. In this technique, the contour scanning line is generated in the area of ​​the cross-sectional shape of the object, limited to the surface area of ​​the object. Then, in the area inside the surface area of ​​the object, multiple scanning lines are generated by a raster scanning method. As a result, in this sintering process, beam scanning (vector scanning) along the contour scanning line and beam scanning (raster scanning) along the multiple scanning lines are performed. Therefore, it is possible to suppress the occurrence of unevenness on the surface of the object, including the above-mentioned contour portions P21, P22, P23, and P24 (see FIG. 22). In addition, when the raster scanning method is applied to an area inside the surface area of ​​the object, there is an advantage that a wide area can be melted quickly and uniformly when the cross-sectional shape of the object is melted by beam scanning.

[0102] However, even when a contour scanning line is generated in the surface region of the object as described above and multiple scanning lines are generated in the region inside the surface region of the object by the raster scanning method as described above, if the polygon 2A is regarded as the region to which the raster scanning method is applied, melting defects due to insufficient melting or excessive melting occurring in the above-mentioned contour portions P21, P22, P23, and P24 (see FIG. 22) may occur. Even in such a case, the modeling data generation unit 303 generates multiple scanning lines 2B(j) and multiple correction scanning lines 2E(i) as shown in FIG. 28 above, thereby eliminating insufficient melting and excessive melting, and thus suppressing the occurrence of melting defects.

[0103] <Modifications, etc.> The technical scope of the present invention is not limited to the above-described embodiments, but also includes forms in which various modifications and improvements are made within the scope that can derive specific effects obtained by the constituent elements of the invention and their combinations.

[0104] For example, when multiple scanning lines are generated by a predetermined beam scanning method, if there are both sparse and dense parts in the arrangement of the scanning lines, the modeling data generating unit 303 may generate correction scanning lines only in the sparse parts, or may generate correction scanning lines only in the dense parts. However, it is preferable that the modeling data generating unit 303 generates correction scanning lines in the parts where the arrangement of the scanning lines is sparse and dense. [Explanation of symbols]

[0105] 10...3D additive manufacturing device 15...Electron beam (charged particle beam) 30...Modeling data creation device 38...Sculpted object (article) 303…Modeling data generation unit 40…Cross-sectional shape 41~47…Scanning lines 61~66…Scanning lines 71~77…Correction scan lines 2A…Polygon (cross-sectional shape) 2B(j)…scanning line 2E(i)…Correction scan line P21, P22, P23, P24...Contour parts

Claims

1. A modeling data creation device that creates modeling data for controlling a three-dimensional additive manufacturing device that melts a cross-sectional shape of each layer by irradiating the layer with a beam to create an article, comprising: A modeling data generating unit generates a plurality of scanning lines in a region of the cross-sectional shape cut out from the three-dimensional shape data of the article by a predetermined beam scanning method, and generates correction scanning lines in a portion where the arrangement of the scanning lines becomes sparse and / or dense. Modeling data creation device.

2. The plurality of scanning lines are concentric scanning lines generated by a tree-ring-shaped vector scanning method; The modeling data generation unit generates the correction scanning lines in a portion where the arrangement of the concentric scanning lines becomes sparse and / or dense. The modeling data creating apparatus according to claim 1 .

3. The modeling data generating unit adds the correction scanning line in the sparse portion and replaces the scanning line with the correction scanning line in the dense portion. The modeling data creating apparatus according to claim 2 .

4. The plurality of scanning lines are parallel scanning lines generated by a raster scanning method, The modeling data generating unit generates the correction scanning line at a contour portion of the cross-sectional shape that is inclined with respect to the scanning line. The modeling data creating apparatus according to claim 1 .

5. The shaping data generating unit generates the correction scanning line between adjacent scanning lines in a direction perpendicular to the scanning lines. The modeling data creating apparatus according to claim 4 .

6. a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating the layer with a beam to form an article; A three-dimensional additive manufacturing system comprising: a modeling data creation device that creates modeling data for controlling the three-dimensional additive manufacturing device, the modeling data creation device includes a modeling data generation unit that generates a plurality of scanning lines in a region of the cross-sectional shape cut out from the three-dimensional shape data of the article by a predetermined beam scanning method, and generates correction scanning lines in a portion where the arrangement of the scanning lines becomes sparse and / or dense; The three-dimensional additive manufacturing apparatus manufactures the article by scanning the beam along the plurality of scanning lines and the correction scanning line. 3D additive manufacturing system.

7. A three-dimensional additive manufacturing method for forming an article by melting a cross-sectional shape of each layer by irradiating the layer with a beam, comprising the steps of: A plurality of scanning lines are generated in a region of the cross-sectional shape cut out from the three-dimensional shape data of the article by a predetermined beam scanning method, and correction scanning lines are generated in a portion where the arrangement of the scanning lines becomes sparse and / or dense, and the article is shaped by scanning the beam along the plurality of scanning lines and the correction scanning lines. Three-dimensional additive manufacturing method.

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