Modeling data creation device, three-dimensional additive manufacturing system, and cumulative energy density distribution display method

Abstract

To solve the following problem: a small region where there is an excess or shortage of cumulative energy density, which occurs when an energy beam having an uneven energy density distribution in a cross-section is scanned on the modeling surface, could not be visually obtained.SOLUTION: An apparatus for creating modeling data 30 that creates the modeling data for controlling a three-dimensional additive manufacturing device 10 that creates an object by melting the cross-sectional shape of each layer with a beam, includes a display control part 305 for generating data indicating a distribution of an irradiation energy density accumulated in a target layer by beam scanning of the target layer based on the modeling data and for outputting the data to a display device 42.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 cumulative energy density distribution display method. [Background technology]

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

[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 using 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") that incorporates 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 on any computer.

[0004] The CAM software in the modeling data creation device first cuts out the cross-sectional shapes of each layer at intervals equal to the thickness of one layer from the input three-dimensional shape data. Next, it determines the modeling conditions for melting the cross-sectional shapes of each layer. The modeling data is the result of applying the modeling conditions to the cross-sectional shapes of each layer and outputting the results as an electronic file. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-042465 Summary of the Invention [Problem to be solved by the invention]

[0006] Lasers or charged particle beams (hereinafter referred to as "energy beams") are controlled to have a constant size on the build surface (especially when the cross section is approximated as circular, this is expressed in terms of diameter (radius or diameter)). However, the energy density distribution within the cross section of the energy beam on the build surface is generally not uniform. There are multiple possible reasons why the energy density distribution of the beam cross section is non-uniform. For example, in addition to fundamental reasons attributable to the beam source, such as the oscillator, cathode, or emitter, there are also possible aberrations when the beam passes through lenses between the beam source and the build surface, apertures, deflection devices, and the influence of foreign objects present near the beam path. One of the simplest approximations of the energy density distribution of the beam cross section on the build surface is a two-dimensional Gaussian distribution.

[0007] When an energy beam, whose cross-sectional energy density distribution is essentially not uniform, is scanned and irradiated onto a build surface at a finite (finite meaning neither infinitesimal nor infinitely large) scanning point spacing or scanning line spacing, the cumulative energy density distribution on the build surface due to the irradiation of the energy beam will also not be uniform.

[0008] If this microscopic cumulative energy density distribution is within a range that is neither too much nor too little for adequately fusing and bonding the outermost surface of the powder bed in every minute region within the melting target region, it is believed that the entire melting target region will be adequately melted, resulting in the creation of a good, defect-free molded object. If this is not the case, in minute regions where the cumulative energy density is insufficient, unmelted material powder will remain, increasing the likelihood of creating a defective molded object. Furthermore, in minute regions where the cumulative energy density is excessive, defects such as voids due to over-melting or vaporization will occur, increasing the likelihood of creating a defective molded object.

[0009] Given the above situation, there was a demand for a method (means) to visually grasp the existence of minute areas on the build surface where the cumulative energy density is excessive or insufficient, which occurs when an energy beam with an uneven cross-sectional energy density distribution is scanned and irradiated onto the build surface, as a method (means) for verifying and validating build data. [Means for solving the problem]

[0010] In order to solve the above problem, one embodiment 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 display control unit that generates data indicating the distribution of irradiation energy density accumulated in a target layer by beam scanning the target layer based on the modeling data and outputs the data to a display device.

[0011] One aspect of the present invention is a three-dimensional additive manufacturing system that includes 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 manufacturing data creation device that creates manufacturing data for controlling the three-dimensional additive manufacturing device, and the manufacturing data creation device includes a display control unit that generates data indicating the distribution of irradiation energy density accumulated in the target layer by beam scanning the target layer based on the manufacturing data, and outputs the data to a display device.

[0012] One embodiment of the present invention provides a cumulative energy density distribution display method, which is a cumulative energy density distribution display method using a modeling data creation device that creates modeling data for controlling a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating it with a beam to form an article, and includes a process of calculating, based on the modeling data, the irradiation energy density accumulated in a target layer by beam scanning of the target layer, and a process of generating data showing the distribution of the irradiation energy density accumulated in the target layer and outputting the data to a display device. [Effects of the Invention]

[0013] According to at least one aspect of the present invention, it is possible to visually grasp the existence of microscopic areas where the cumulative energy density is excessive or insufficient, which occurs when an energy beam with an uneven cross-sectional energy density distribution is scanned over a build surface. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram schematically illustrating an example of the configuration of a three-dimensional additive manufacturing system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating 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. [Figure 3] 3 is a flowchart showing an example of the procedure of processing operations of the three-dimensional additive manufacturing apparatus according to the first embodiment of the present invention. [Figure 4] 1 is a block diagram showing an example of the configuration of a modeling data creation apparatus according to a first embodiment of the present invention. [Figure 5] 2 is a block diagram showing an example of the configuration of a display control unit included in the modeling data creation apparatus according to the first embodiment of the present invention. FIG. [Figure 6] 1 is a block diagram showing an example of the hardware configuration of a computer included in a modeling data creation apparatus according to a first embodiment of the present invention. [Figure 7] 5 is a flowchart showing an example of a display process of a cumulative energy density distribution by the modeling data creation device according to the first embodiment of the present invention. [Figure 8]FIG. 1 is a diagram showing an example (part 1) visually representing a scanning path of a conventional energy beam. [Figure 9] FIG. 10 is a diagram showing a visual example (part 2) of a conventional energy beam scanning path. [Figure 10] FIG. 2 is a diagram showing an example of a display screen showing a cumulative energy density distribution by the modeling data creation device according to the first embodiment of the present invention. [Figure 11] 10 is a flowchart showing an example of a display process of a cumulative energy density distribution by a modeling data creation device according to a second embodiment of the present invention. [Figure 12] FIG. 10 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (without correction) by the modeling data creating device according to the second embodiment of the present invention. [Figure 13] FIG. 10 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (with first correction) by the modeling data creating device according to the second embodiment of the present invention. [Figure 14] FIG. 10 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (with second correction) by the modeling data creating device according to the second embodiment of the present invention. [Figure 15] FIG. 10 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (with first and second corrections) by the modeling data creating device according to the second embodiment of the present invention. [Figure 16] 11 is a flowchart showing an example of a display process of a cumulative energy density distribution by a modeling data creation device according to a third embodiment of the present invention. [Figure 17] FIG. 10 is a diagram (part 1) showing an example of a display screen showing a cumulative energy density distribution in the middle of energy beam scanning by the modeling data creation device according to the third embodiment of the present invention. [Figure 18] FIG. 11 is a diagram (part 2) showing an example of a display screen showing a cumulative energy density distribution in the middle of energy beam scanning by the modeling data creation device according to the third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, examples of modes for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the accompanying drawings. In this specification and the accompanying drawings, identical or similar components are given the same reference numerals, and redundant explanations may be omitted or only explanations focusing on the differences may be given. The number of each component may be singular or plural unless otherwise specified.

[0016] First Embodiment First, a three-dimensional additive manufacturing system according to a first embodiment of the present invention will be described with reference to FIGS.

[0017] FIG. 1 is a diagram schematically illustrating an example of the configuration of a three-dimensional additive manufacturing system according to a first embodiment of the present invention. In FIG. 1, a three-dimensional additive manufacturing system 1 includes a three-dimensional additive manufacturing device 10 and a manufacturing data creation device 30.

[0018] [3D additive manufacturing equipment] A schematic side view of the three-dimensional additive manufacturing apparatus 10 is shown. In the following description, in order to clarify the shapes and positional relationships of the various parts of the three-dimensional additive manufacturing apparatus 10, the left-right direction in FIG. 1 will be referred to 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 directions that are perpendicular to one another. Furthermore, the X direction and Y direction are directions parallel to the horizontal direction, and the Z direction is a direction parallel to the vertical direction.

[0019] As shown in FIG. 1, the 3D additive manufacturing apparatus 10 mainly comprises a vacuum chamber 12, a beam irradiation device 14, a powder application device 16, a build plate 22, an inner base 24, and a plate movement device 26. The 3D additive manufacturing apparatus 10 manufactures an article (hereinafter also referred to as a "built object") using the powder bed fusion method described above. In this embodiment, the beam irradiated onto the surface of the powder layer is a charged particle beam, more specifically, an electron beam, as an example. However, the beam is not limited to a charged particle beam and may be, for example, a laser beam. When a laser beam is used, it is not necessary to evacuate the chamber.

[0020] The vacuum chamber 12 is a chamber for creating a vacuum by evacuating the air inside the chamber using 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.

[0021] The beam irradiation device 14 is a device that irradiates the surface of the powder layer, i.e., the build surface, with an electron beam 15. The electron beam 15 is an example of a charged particle beam. As an example, the beam irradiation device 14 includes an electron gun that generates the electron beam 15, a focusing lens that focuses the electron beam 15 generated by the electron gun, and a deflection device that deflects the electron beam 15.

[0022] The electron beam 15 is focused by a magnetic field generated by a focusing coil that constitutes a focusing lens. The size of the electron beam 15 on the building surface can be adjusted by the focusing lens. The deflection device is configured using deflection coils, and deflects the electron beam 15 by a magnetic field generated by the deflection coil. Scanning of the electron beam 15 on the building surface is achieved by the deflection device.

[0023] The powder coating device 16 is a device that coats the metal powder 32, which is the raw material of the molded object 38, onto the build plate 22 to form a powder layer. The metal powder 32 is an example of a powder that is the raw material of the molded object 38. As an example, the powder coating device 16 includes a hopper, which is a container for storing the metal powder, a powder dropper, and a squeegee (not shown). The powder dropper is a device that drops the powder stored in the hopper onto the inner base 24. The squeegee is an elongated member that is long in the Y direction. The squeegee moves horizontally over the build plate 22 from one end to the other end of the inner base 24 to spread the metal powder 32. This forms a powder layer on the build plate 22. The squeegee 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 inner base 24.

[0024] 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 have a circular or angular shape in plan view.

[0025] The inner base 24 is movable in the vertical direction (Z direction) by being driven by the plate moving device 26. The shaping plate 22 moves vertically together with the inner base 24. The inner base 24 has larger outer dimensions than the shaping plate 22. For example, the inner base 24 moves vertically in the space below an opening formed in the center of the shaping table (not shown).

[0026] The plate moving device 26 is a device that moves the shaping plate 22 and the inner base 24 in the up-down direction. As an example, the plate moving device 26 includes a shaft and a drive mechanism. The shaft is connected to the underside of the inner base 24. The drive mechanism includes a motor and a power transmission mechanism (not shown), and by using the motor as a drive source to drive the power transmission mechanism, the shaping plate 22 and the inner base 24 are moved up-down together with the shaft.

[0027] The three-dimensional additive manufacturing apparatus 10 shown in FIG. 1 is a schematic illustration of the principle of the powder bed fusion method, and is not limited to this example.

[0028] [Modeling data creation device] The modeling data creation device 30 creates modeling data using three-dimensional shape data of an article generated by a three-dimensional CAD or the like. The modeling data created by the modeling data creation device 30 is recorded, for example, on 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 the control unit 11 of the three-dimensional additive manufacturing device 10. The control unit 11 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 article in accordance with the modeling data created by the modeling data creation device 30.

[0029] 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. Furthermore, the three-dimensional additive manufacturing device 10 may be configured to have all of the functions of the modeling data creation device 30 (see FIG. 4).

[0030] The modeling data created by the modeling data creation device 30 includes modeling data for controlling the operation of the beam irradiation device 14, modeling data for controlling the powder coating device 16, and modeling data for controlling the plate moving device 26. However, this specification will explain the creation of modeling data for controlling the operation of the beam irradiation device 14, and will omit explanations regarding the creation of other modeling data.

[0031] FIG. 2 is a diagram showing an example of the configuration of a control system of the three-dimensional additive manufacturing apparatus 10 according to the first embodiment of the present invention. 2, the control unit 11 is configured by a computer including a processor 11a such as a CPU (Central Processing Unit) and a storage unit 11b such as a ROM (Read Only Memory), RAM (Random Access Memory), HDD (Hard Disk Drive), or SSD (Solid State Drive). The control unit 11 comprehensively controls the operation of the 3D 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 11 also controls the operation of the entire 3D additive manufacturing apparatus 10 in accordance with modeling data, which will be described later. The control unit 11 is connected to a beam irradiation device 14, a powder coating device 16, and a plate moving device 26 as control targets.

[0032] The beam irradiation device 14 irradiates the electron beam 15 based on control commands given by the control unit 11. At this time, the control unit 11 controls the electron beam 15 via an electron gun, a focusing lens, and a deflection device (not shown). For example, the control unit 11 controls the beam current of the electron beam 15 via the beam irradiation device 14. The control unit 11 also controls the spot size of the electron beam 15 via the focusing lens. The spot size of the electron beam 15 is the size of the electron beam 15 on the fabrication surface. The control unit 11 also controls the deflection angle and deflection speed of the electron beam 15 via the deflection device. 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 movement speed of the electron beam 15.

[0033] The plate moving device 26 moves the building plate 22 and the inner base 24 based on control commands given by the control unit 11. The powder coating device 16 applies metal powder 32 onto the building plate 22 based on control commands given by the control unit 11 to form a powder layer. The operations of the elements of the powder coating device 16 (hopper, powder dropper, and squeegee) are controlled by the control unit 11.

[0034] [Operation of 3D additive manufacturing equipment] 3 is a flowchart showing an example of the procedure of the processing operation of the three-dimensional additive manufacturing apparatus 10 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 11.

[0035] Before the start of manufacturing, the periphery of the manufacturing plate 22 is covered with the metal powder 32, except for the upper surface of the manufacturing plate 22. The upper surface of the manufacturing plate 22 is positioned at approximately the same height as the upper surface of the metal powder 32 spread on the inner base 24.

[0036] (Plate heating process) First, the beam irradiation device 14 operates based on a control command given from the control unit 11 to heat the modeling plate 22 (step S1). In step S1, the beam irradiation device 14 irradiates the build plate 22 with the electron beam 15. As a result, the build plate 22 is heated to a temperature at which the metal powder 32 is pre-sintered.

[0037] (Plate lowering process) Next, the plate moving device 26 operates based on a control command given from the control unit 11 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 reference position. At this time, the shaping plate 22 is lowered by the 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 formed by stacking.

[0038] (Powder coating process) Next, the powder coating device 16 operates based on a control command given from the control unit 11 to coat the metal powder 32 onto the shaping plate 22 to form a powder layer (step S3). In step S3, the powder coating device 16 drops the metal powder 32 onto the inner base 24, and then moves the squeegee in the X direction to spread the metal powder 32 over the building plate 22. At this time, the metal powder 32 is spread over the building plate 22 to a thickness equivalent to ΔZ. This forms a powder layer on the building plate 22. In addition, excess metal powder 32 is collected in a collection box (not shown).

[0039] (Preheating process) Next, the beam irradiation device 14 operates based on control commands given by the control unit 11 to preheat the powder layer on the building plate 22 (step S4). In this preheating step S4, the powder layer 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 heating step. The powder layer includes an unsintered region where unsintered metal powder 32 exists and a pre-sintered region where pre-sintered metal powder 32 exists.

[0040] (Main sintering process) Next, the beam irradiation device 14 operates based on a control command given from the control unit 11, thereby melting and solidifying the metal powder 32 to perform main sintering (step S5). In step S5, the metal powder 32 that has been pre-sintered as described above is irradiated with the electron beam 15 to melt and solidify, thereby finally sintering the metal powder 32 as a pre-sintered body. In step S5, the control unit 11 determines the cross-sectional shape of each layer extracted from the three-dimensional shape data of the target object 38 as the melting target region, and controls the beam irradiation device 14 in accordance with the shaping data associated with the cross-sectional shape. As a result, the melting target region represented by the two-dimensional cross-sectional shape of the metal powder 32 on the shaping plate 22 is melted by irradiation with the electron beam 15. The metal powder 32 melted by irradiation with the electron beam 15 solidifies after the electron beam 15 has passed. This forms the first layer of the shaping object.

[0041] (Plate lowering process) Next, the plate moving device 26 operates based on a control command given from the control unit 11 to lower the modeling plate 22 by a predetermined amount (ΔZ) (step S6). In step S6, the plate moving device 26 lowers the build plate 22 and the inner base 24 by ΔZ.

[0042] (First preheating step) Next, the beam irradiation device 14 operates based on control commands given by the control unit 11 to preheat the powder layer on the build plate 22 (step S7). In this first preheating step S7, the powder layer that has already undergone the main sintering step in the previous layer is preheated in preparation for the laying of the next layer of metal powder 32. As a result, the powder layer is heated to a temperature at which the metal powder 32 in the next layer is heated by heat conduction from the current layer and pre-sintered. This preheating step S7 may be performed after the main sintering step S5 described above or after the main sintering step S10 described below. This preheating step performed after the main sintering step is also called an afterheating step.

[0043] (Powder coating process) Next, the powder coating device 16 operates based on a control command given from the control unit 11 to coat the metal powder 32 onto the shaping plate 22 to form a powder layer (step S8). In step S8, the powder coating device 16 operates in the same manner as in step S3 above, whereby the second layer of metal powder 32 is spread over the sintered body formed from the first layer of metal powder 32 on the shaping plate 22 to form a powder layer.

[0044] (Second preheating step) Next, the beam irradiation device 14 operates based on a control command given from the control unit 11 to preheat the metal powder 32 forming the second powder layer (step S9). This preheating step S9 is performed before the main sintering step 10, which will be described later. Therefore, this preheating step S9 is also called a powder heating step. In step S9, the beam irradiation device 14 operates in the same manner as in step S4, whereby the metal powder 32 forming the second powder layer is pre-sintered.

[0045] (Main sintering process) Next, the beam irradiation device 14 operates based on a control command given from the control unit 11, thereby melting and solidifying the metal powder 32 forming the second powder layer to perform main sintering (step S10). In step S10, the beam irradiation device 14 operates in the same manner as in step S5, thereby forming the second layer of the shaped object.

[0046] Next, the control unit 11 checks whether or not the formation of the target object 38 has been completed (step S11). If the control unit 11 determines that the formation of the object 38 has not been completed (determination of NO), the process returns to step S6. As a result, the control unit 11 repeats the processes of steps S6 to S10 for each layer from the third layer onwards. If the control unit 11 determines that the formation of the object 38 has been completed (determination of YES), the series of processes ends at that point. The desired object 38 is obtained by the three-dimensional additive manufacturing process described above.

[0047] [Configuration of modeling data creation device] Next, the configuration of the modeling data creating apparatus according to the first embodiment of the present invention will be described with reference to FIG.

[0048] FIG. 4 is a block diagram showing an example of the configuration of the modeling data creating device 30. As shown in FIG. 4, the modeling data creation device 30 includes an import unit 301, a modeling data creation unit 302, an output processing unit 303, modeling data 304, and a display control unit 305. The display control unit 305 is connected to an input device 41 (an example of an input unit) and a display device 42 (an example of an output unit).

[0049] 6, the modeling data creation device 30 is configured by a computer including a processor 60a such as a CPU, and a storage unit 60b such as a ROM, a RAM, an HDD, or an SSD. For example, a general-purpose PC (Personal Computer) can be used as the modeling data creation device 30. 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.

[0050] The modeling data creation device 30 also includes an input / output I / F 60c and a communication I / F 60d. The input / output I / F 60c performs input processing of UI (User Interface) information input from an input device 41 (FIG. 4) and performs output processing of display data to be output to a display device 42 (FIG. 4). The input device 41 is a keyboard, a mouse, or the like. Furthermore, the input device 41 may be a touch panel in which a touch sensor and a display panel are stacked. The communication I / F 60d performs communication processing to send and receive information between the control unit 11 of the 3D additive manufacturing device 10 and other information processing devices (not shown). The control unit 11 shown in Fig. 2 can be considered to have the same functions as the input / output I / F 60c and the communication I / F 60d.

[0051] Returning to the description of Fig. 4, the import unit 301 imports three-dimensional shape data input to the modeling data creation device 30 via the communication I / F 60d, and outputs the data to the modeling data creation unit 302.

[0052] The modeling data creation unit 302 cuts out the cross-sectional shape of each layer from the three-dimensional shape data imported by the import unit 301. This cross-sectional shape is a two-dimensional cross-sectional shape that represents the shape of the area in each powder layer that is to be melted by irradiation with an energy beam (electron beam 15 in this specification), i.e., the area to be melted. Furthermore, the cross-sectional shape cut out by the modeling data creation unit 302 is a shape represented by one or more closed lines. Note that the number of cross-sectional shapes cut out from one powder layer may be multiple.

[0053] Then, the shaping data creation unit 302 applies the shaping conditions to the cross-sectional shape to generate shaping data 304, and stores it in the memory unit 60b (FIG. 6). This shaping data corresponds to shaping data (operation sequence program) used by the control unit 11 to control the operation of the beam irradiation device 14 in the main sintering steps S5 and S10 (FIG. 3).

[0054] The molding conditions include beam scanning conditions and beam irradiation conditions. Beam scanning conditions are conditions that are applied when scanning the surface of the powder layer with an energy beam (electron beam 15 in this embodiment). Beam irradiation conditions are conditions that are applied when irradiating the surface of the powder layer with an energy beam (electron beam 15 in this embodiment). There are various beam scanning conditions, and there are also various beam irradiation conditions. Specific examples of beam scanning conditions and beam irradiation conditions are described below.

[0055] Beam scanning conditions include the beam scanning method, the distance between adjacent scan lines (scan line spacing), and the scanning speed. Beam scanning methods include raster scanning, vector scanning, and random scanning. Raster scanning is a method in which parallel scan lines are generated and the beam scans along the generated scan lines. Raster scanning is divided into one-way raster scanning and reciprocating raster scanning. Vector scanning is a method in which tree-ring-shaped scan lines are generated to match the contour lines that form the cross-sectional shape and the beam scans along the generated scan lines. Random scanning is a method in which the beam randomly scans the area of ​​the cross-sectional shape. When the surface of the powder layer is scanned with the electron beam 15, the center of the spot of the electron beam 15 moves along the scan line.

[0056] On the other hand, the beam irradiation conditions include the current amount of the charged particle beam, the beam size on the build surface, etc. The current amount of the charged particle beam corresponds to the beam current amount. In this embodiment, an electron beam 15 is used as the charged particle beam. Therefore, the current amount of the electron beam 15 corresponds to the current amount of the charged particle beam. Furthermore, the size (spot size) of the electron beam 15 on the build surface corresponds to the beam size on the build surface. When the beam irradiated onto the surface of the powder layer is a laser beam, the beam irradiation conditions include the laser intensity, the beam size on the build surface, etc. The laser intensity corresponds to the intensity of the laser beam, i.e., the beam intensity.

[0057] The intensity of an energy beam is the energy of the energy beam irradiated on a unit area in a unit time (e.g., W / cm 2 Energy density is defined as the energy of an energy beam irradiated onto a unit area over a certain period of time, so the longer the irradiation time on the same area, the higher the energy density.

[0058] The modeling conditions are set taking into consideration the beam scanning method (vector scanning, raster scanning), scanning line spacing, scanning speed, type of energy beam, irradiation energy (charged particle beam current, laser beam intensity), beam size on the modeling surface, etc. Each manufacturer of 3D additive manufacturing equipment conducts research into the specific modeling conditions to apply to cross-sectional shapes, so we will only provide an overview here and omit detailed explanations.

[0059] The output processing unit 303 outputs the modeling data 304 generated by the modeling data creation unit 302 to an electronic file. The modeling data 304 output to the electronic file is provided to the three-dimensional additive manufacturing device 10 by the above-mentioned method (for example, a method using a portable recording medium). Furthermore, if an article to be modeled is to be modeled by layering, for example, 100 layers, modeling data 304 for 100 layers is provided to the three-dimensional additive manufacturing device 10. The control unit 11 of the three-dimensional additive manufacturing device 10 then sequentially controls the operation of the entire three-dimensional additive manufacturing device 10 in accordance with the modeling data 304 provided from the modeling data creation device 30.

[0060] The display control unit 305 generates display data indicating the distribution of irradiation energy density accumulated in each layer by beam scanning on each layer (hereinafter referred to as "cumulative energy density distribution") based on the modeling data 304, and outputs this display data to the display device 42 via the input / output I / F 60c. The display device 42 displays the cumulative energy density distribution of the specified layer sent from the display control unit 305 on the display screen. The display control unit 305 receives the layer number to be displayed (see FIG. 10) specified by the operator from the input device 41, generates the cumulative energy density distribution of the specified layer, and outputs it as display data. The display device 42 displays the cumulative energy density distribution of the layer specified by the user on the display screen based on the display data sent from the display control unit 305.

[0061] [Configuration of display control unit] Next, the configuration of the display control unit 305 included in the modeling data creation apparatus 30 according to the first embodiment of the present invention will be described with reference to FIG.

[0062] FIG. 5 is a block diagram showing an example of the configuration of the display control unit 305 included in the modeling data creation device 30. As shown in FIG. As shown in FIG. 5, the display control unit 305 includes a reading unit 501, a motion element decomposition unit 502, an irradiation energy density calculation unit 503, and a display data generation unit 504.

[0063] The reading unit 501 reads the modeling data 304 of a specified layer from the modeling data 304 of each layer (FIG. 4) stored in the storage unit 60b based on the UI information, and outputs the modeling data 304 to the action element decomposition unit 502.

[0064] The action element decomposition unit 502 decomposes the scanning of the energy beam on the specified layer into action elements, point by point or line by line, for the modeling data 304 of the target layer read by the reading unit 501. Whether the decomposition unit is point by point or line by line may be determined according to the unit of command given to the deflection device of the 3D additive manufacturing device 10. For example, if an instruction is given to the deflection device for each beam irradiation, the decomposition unit is set to point by point, and if an instruction is given to the deflection device for multiple beam irradiations (corresponding to one line) as one unit, the decomposition unit is set to line by line. An example of one line is one side of a polygon that forms the cross-sectional shape.

[0065] The irradiation energy density calculation unit 503 calculates the energy density to be irradiated for each of the motion elements decomposed by the motion element decomposition unit 502, for each minute region corresponding to each of all display pixels at the specified display magnification. The size of the minute region corresponding to each pixel on the modeling surface varies depending on the display magnification. The display magnification may be set in advance, or the operator may be able to specify any display magnification.

[0066] The energy density irradiated to a micro-area is calculated taking into account the manufacturing conditions. For example, the manufacturing conditions include the energy density distribution of the beam cross section (beam spot on the manufacturing surface), the scanning speed, the scanning point interval, and the beam scanning path. The scanning point interval is the interval (distance) between irradiation positions in successive beam irradiations. From the scanning speed and the scanning point interval, the time the beam spot stayed in each micro-area can be calculated. Knowing the beam spot's stay time allows the amount of beam energy irradiated to each micro-area to be determined.

[0067] The irradiation energy density calculation unit 503 then stores the irradiation energy density 510 calculated for each microregion corresponding to each pixel for each operating element of the planned beam scanning path in the memory unit 60b. The irradiation energy density information is stored in a scalar value memory area reserved for each microregion corresponding to each pixel in the memory unit 60b, and is added to the previous value. Therefore, in microregions where multiple beam spots overlap, the irradiation energy density is integrated and stored. The integrated irradiation energy density corresponds to the cumulative energy density. Furthermore, the cumulative energy density for each microregion on the printing surface corresponds to the cumulative energy density distribution on the printing surface.

[0068] The display data generation unit 504 associates the cumulative energy density of the minute region corresponding to each pixel stored in the storage unit 60b with a shade, hue, or any color map to create cumulative energy density distribution data on the printing surface. A visualization method in which an image is painted with a continuous change in color tone depending on the value of each point or region (in this invention, cumulative energy density) is also called a heat map. The display data generation unit 504 then outputs the cumulative energy density distribution data to the display device 42 as display data, and graphically displays the cumulative energy density distribution on the printing surface on the display screen of the display device 42. The display screen is provided with a mechanism for displaying and specifying layer numbers (see FIG. 10).

[0069] [Operation of 3D additive manufacturing equipment] 7 is a flowchart showing an example of a display process of the accumulated energy density distribution by the shaping data creation device 30 according to the first embodiment of the present invention. The operation of this flowchart is realized by the processor 60a (FIG. 6) reading and executing a program written in the storage unit 60b. The process of this flowchart starts when the operator presses the "update" instruction button (see FIG. 10) on the display screen.

[0070] First, in the display control unit 305, the reading unit 501 reads an operation (UI information) by an operator from the input device 41 (step S21). As an example, the UI information includes the layer number for which the cumulative energy density distribution is to be displayed. Next, the reading unit 501 reads the modeling data 304 of the specified layer number from the modeling data 304 stored in the storage unit 60b (step S22).

[0071] Next, the motion element decomposition unit 502 decomposes the scanning of the energy beam in the designated layer into motion elements (step S23).

[0072] Next, the irradiation energy density calculation unit 503 calculates, for all the operation elements, the irradiation energy density 510 for each micro-region corresponding to each display pixel at the specified display magnification, based on the modeling conditions (step S24). Then, the irradiation energy density calculation unit 503 stores the irradiation energy density 510 of each micro-region calculated for each operation element in a memory area reserved for each micro-region in the memory unit 60b (step S25). A scalar value of the irradiation energy density is stored in this memory area.

[0073] Next, the display data generation unit 504 generates cumulative energy density distribution data (display data) of the specified layer from the irradiation energy density 510 for each microregion of the specified layer stored in the storage unit 60b, and outputs the data to the display device 42 (step S26). As a result, the cumulative energy density distribution of the layer specified by the operator for the pixels to be displayed is graphically displayed on the display device 42.

[0074] By the above-described operation of the modeling data creating device 30 (the display control unit 305), the cumulative energy density distribution of the specified layer is graphically displayed.

[0075] [Example of conventional energy beam scanning path] Here, an example visually showing a conventional scanning path of an energy beam will be described with reference to FIGS. FIG. 8 is a diagram showing an example (part 1) visually representing a scanning path of a conventional energy beam. FIG. 9 is a diagram showing a visual example (part 2) of a conventional energy beam scanning path.

[0076] If the cumulative energy density distribution on the build surface is excessive or insufficient, the melting target area of ​​the powder layer (e.g., the cross section of the build object) will not melt well. An example of an area where this is likely to occur is the area along the line connecting the endpoints of adjacent scan lines when raster scanning an energy beam. In this area, the envelope of the cumulative energy density distribution will have a jagged shape (step-like), and the cumulative energy density will decrease in the microscopic areas corresponding to these depressions, increasing the possibility of defects due to insufficient melting of the powder, resulting in unmelted powder.

[0077] As another example, this problem is likely to occur in areas where certain conditions are met, such as when an energy beam is vector-scanned to match the shape of the target melting area. For example, depending on the combination of the shape of the target melting area and the distance and positional relationship between adjacent scan lines, there may be areas where the scan lines are densely or sparsely spaced. In such areas, the cumulative energy density may be excessive or insufficient. This increases the likelihood of defects due to insufficient or excessive melting of the powder in the target melting area.

[0078] In conventional technology, the beam scanning path is visually confirmed by a line as shown in Fig. 8, or by a line whose thickness reflects the beam diameter as shown in Fig. 9. Figs. 8 and 9 show examples of a scanning line that matches the contour of an octagonal cross-sectional shape, and multiple parallel scanning lines within the contour. In Fig. 8, dashed lines 81 and 82 indicate areas where the cumulative energy density may be too high, and dashed lines 83 and 84 indicate areas where the cumulative energy density may be too low.

[0079] However, these conventional display methods cannot express the overlap of the irradiation energy density distributions from adjacent scanning lines, and therefore, when the energy beam is scanned across the build surface, it is not possible to confirm whether the accumulated irradiation energy density is within a range sufficient to build a good build in every microscopic area.

[0080] Therefore, the operator could not confirm before the modeling whether the beam scanning path and beam scanning conditions were optimally designed for good modeling. As a result, there was a possibility that the modeling would be performed with the beam scanning path and beam scanning conditions inappropriately designed. This could result in the manufacturing of defective products, lowering yield and reducing production efficiency.

[0081] For the same reason, when a defect is found in the manufactured object through inspection after the manufacturing process, it is difficult to determine or identify the cause, such as whether the cause is in the design of the energy beam scanning path or due to other reasons. For example, other causes may include a defect in the beam irradiation device 14 or other mechanical operations of the 3D additive manufacturing device, or a defect in the material powder. Therefore, in order to solve these problems, the present invention has a configuration for visually displaying the cumulative energy density distribution of each layer.

[0082] [Display screen showing cumulative energy density distribution] Next, an example of a display screen showing the cumulative energy density distribution according to the first embodiment of the present invention will be described with reference to FIG.

[0083] FIG. 10 is a diagram showing an example of a display screen showing the cumulative energy density distribution by the modeling data creating device 30. 10, a display screen 100 (an example of a user interface) has an accumulated energy density distribution display area 101, a layer number display area 102, and an update button 103. The accumulated energy density distribution displayed on the display screen 100 is based on the printing data created by the printing data creation unit 302 (FIG. 4) and read into the display control unit 305. When the memory unit 60b stores printing data for multiple three-dimensional shape data, the input device 41 may be configured to allow the operator to specify the three-dimensional shape data (printing data).

[0084] The layer number display area 102 (an example of a designation function) is provided with a layer number display field 102a. The operator can confirm which layer the currently displayed cumulative energy density distribution is for by looking at the layer number displayed in the layer number display field 102a. The layer number display field 102a is also a field where the operator can designate the layer number he or she wants to display. The operator can input the layer number he or she wants to display into the layer number display field 102a by operating the input device 41. After the operator inputs the layer number, the operator presses the update button 103, which causes the display control unit 305 to update the display.

[0085] The cumulative energy density distribution display area 101 (an example of a display function) displays the cumulative energy density distribution for a specified layer of the three-dimensional shape data. The cumulative energy density distribution is displayed in shades, hues, or an arbitrary color map according to the value of the cumulative energy density. For example, colors are set in descending order of cumulative energy density, specifically red, orange, yellow, yellow-green, green, blue, purple, and black, with thresholds defined and in stages. This allows the operator to check the uniformity of the cumulative irradiation energy density distribution in the specified layer.

[0086] In the example shown in FIG. 10, the cumulative energy density distribution of the 301st layer of modeling data is displayed in the cumulative energy density distribution display area 101. The cross-sectional shape of the 301st layer of modeling data has an octagonal beam scanning path (contour line). The 301st layer of modeling data includes a scanning line aligned with the contour line of the cross-sectional shape and multiple parallel scanning lines within the contour line. In the cumulative energy density distribution of the 301st layer, the positions of dashed line portions 105 and 106 correspond to the positions of dashed line portions 81 and 82 shown in FIG. 8. Furthermore, the positions of dashed line portions 107 and 108 correspond to the positions of dashed line portions 83 and 84 shown in FIG. 8.

[0087] The areas surrounded by dashed lines 105 and 106 and the areas surrounded by dashed lines 107 and 108 appear to have the same shade in FIG. 10 , but are actually displayed in different colors on the display screen. The areas surrounded by dashed lines 105 and 106 are colored in a color (e.g., red) that indicates a high cumulative energy density, while the areas surrounded by dashed lines 107 and 108 are colored in a color (e.g., dark blue) that indicates a low cumulative energy density. That is, it can be seen that the area surrounded by dashed lines 105 and 106 is an area where the cumulative energy density may be too high (hereinafter referred to as an "accumulated energy density excess area"). Similarly, it can be seen that the area surrounded by dashed lines 107 and 108 is an area where the cumulative energy density may be too low (hereinafter referred to as an "accumulated energy density insufficient area").

[0088] In the first embodiment described above, it is possible to visually grasp the cumulative irradiation energy density distribution on the surface to be manufactured when the energy beam is scanned along the planned beam scanning path. The cumulative irradiation energy density distribution on the surface to be manufactured reflects the manufacturing conditions (beam scanning conditions, beam irradiation conditions), such as the energy density distribution of the beam cross section, the scanning speed, the scanning interval, and the beam scanning path.

[0089] Excess or insufficient cumulative energy density on the printing surface (uneven cumulative energy density distribution) due to unevenness in the beam scanning path is one of the causes of defects due to excessive or insufficient melting. Therefore, it is desirable to use the printing data creation device 30 according to this embodiment to detect (visually grasp) the presence of minute areas on the printing surface where the cumulative energy density is excessive or insufficient on the printing surface using CAM software. Then, based on the detection results, designing printing conditions to prevent the occurrence of defects and print good products can contribute to reducing the yield of printed objects and improving manufacturing efficiency.

[0090] <Second embodiment> A modeling data creation device according to a second embodiment of the present invention will be described with reference to Figures 11 to 15. The basic configuration of the modeling data creation device according to the second embodiment is the same as the configuration of the modeling data creation device 30 according to the first embodiment (Figures 4 to 6).

[0091] In the second embodiment, correction control applied in actual modeling, such as the energy density and scanning speed of the energy beam, reflecting the arrangement and three-dimensional shape of the model, is applied to the calculation of beam energy, and the cumulative energy density distribution on the modeling surface is displayed. That is, corrections are applied to the modeling conditions of the modeling data, and then the cumulative energy density distribution on the modeling surface is displayed. The display screen is provided with a user interface that allows the user to select whether or not to apply each type of correction for each type of correction. The user interface is, for example, a switch that allows the user to select whether or not to apply the correction.

[0092] FIG. 11 is a flowchart showing an example of a display process of the accumulated energy density distribution by the modeling data creating apparatus according to the second embodiment of the present invention. The flowchart in FIG. 11 differs significantly from the flowchart in FIG. 7 of the first embodiment in that it includes step S24A, in which the irradiation energy density is calculated by applying corrections to the modeling conditions. The operation of this flowchart is realized by the processor 60a (FIG. 6) reading and executing a program written in the storage unit 60b. The storage unit 60b stores a program for calculating various corrections necessary to reproduce various corrections to the modeling conditions performed by the 3D additive manufacturing apparatus 10. The following describes the flowchart in FIG. 11, focusing on differences from FIG. 7, and omitting redundant explanations. This flowchart starts processing when the operator presses the "Update" instruction button (see FIG. 12) on the display screen.

[0093] First, the display control unit 305 (FIG. 4) reads UI information (step S21), reads modeling data of the specified layer (step S22), and decomposes the scanning of the energy beam on the specified layer into operation elements (step S23).

[0094] Next, in the display control unit 305, the irradiation energy density calculation unit 503 calculates the irradiation energy density 510 for each micro-region corresponding to each display pixel at the specified display magnification based on the modeling conditions for all operation elements (step S24A). In step S24A, the reading unit 501 receives, as UI information, the correction type selected in the correction information display area 122 (see FIGS. 12 to 15 described later). The irradiation energy density calculation unit 503 applies the correction information sent from the reading unit 501 to the modeling conditions of each operation element, and calculates the irradiation energy density 510 for each microregion corresponding to each of all display pixels based on the corrected modeling conditions.

[0095] As an example of the various corrections, when the layer directly below the beam irradiation path is an unmelted powder bed, there is a correction to locally increase the scanning speed of the relevant part in order to compensate for variations in the degree of diffusion of thermal energy to the layer below the powder bed that has already been stacked (correction A in FIG. 13). Another example is a correction to locally increase the scanning speed in such a location in order to alleviate the partial concentration of thermal energy due to the influence of thermal diffusion from the adjacent scanning line when scanning the vicinity with little time between the scanning of the adjacent scanning line (correction B in FIG. 14). The contents of the various corrections are not limited to these two examples.

[0096] Then, the irradiation energy density calculation unit 503 stores the irradiation energy density 510 (FIG. 5) of each minute region calculated for each operation element in a storage area secured for each minute region in the storage unit 60b (step S25).

[0097] Next, the display data generation unit 504 generates cumulative energy density distribution data (display data) of the specified layer from the irradiation energy density 510 for each microregion of the specified layer stored in the storage unit 60b, and outputs the data to the display device 42 (step S26). As a result, the cumulative energy density distribution of the layer specified by the operator, which reflects the correction for the pixels to be displayed, is graphically displayed on the display device 42.

[0098] By the above-described operation of the modeling data creation device (the display control unit 305), the corrected cumulative energy density distribution of the specified layer is graphically displayed.

[0099] [Display screen showing correction information and cumulative energy density distribution] Next, examples of display screens showing correction information and cumulative energy density distribution according to the second embodiment of the present invention will be described with reference to Fig. 12 to Fig. 15. Fig. 12 to Fig. 15 have screen configurations that allow the operator to confirm the difference in cumulative energy density distribution between the presence and absence of correction.

[0100] FIG. 12 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (without correction). 12, a display screen 120 (an example of a user interface) has an accumulated energy density distribution display area 121, a correction information display area 122, and an update button 123. As an example, a user interface (not shown) for confirming with the operator whether or not to transition to the correction application mode is displayed on the display screen 100 shown in FIG. 10. Then, when transition to the correction application mode is selected, the display data generating unit 504 displays the display screen 120.

[0101] The correction information display area 122 (an example of a selection function) displays selectable types of correction and check boxes for selecting whether each type of correction is enabled or disabled. The displayed types of correction are corrections that can be performed by the 3D additive manufacturing device 10, but corrections that cannot be performed may be displayed in gray. In the example of FIG. 12, correction A, correction B, and correction C are prepared as correction candidates, but none of corrections A to C are selected as valid. In this embodiment, the desired correction is selected by filling in the check box, but a check mark may also be input. Alternatively, a numerical input field may be used to specify the weight of the correction to be applied. After the operator inputs the correction information, the display control unit 305 updates the display by pressing the update button 123.

[0102] The cumulative energy density distribution display area 121 (an example of a display function) displays the cumulative energy density distribution for a specified layer of the three-dimensional shape data, reflecting the correction information in the correction information display area 122. The cumulative energy density distribution of the layer specified in the layer number display field 102a in the first embodiment is displayed in the cumulative energy density distribution display area 121. The example in FIG. 12 is a cumulative energy density distribution to which no correction has been applied, and is the same as the cumulative energy density distribution of the 301st layer shown in FIG. 10.

[0103] FIG. 13 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (with first correction). On the display screen 120 shown in FIG. 13, an accumulated energy density distribution display area 121 displays an accumulated energy density distribution when correction A (an example of a first correction) is applied to the modeling conditions.

[0104] In the cumulative energy density distribution, the positions of dashed lines 105, 106, 107, and 108 correspond to the positions of dashed lines 105, 106, 107, and 108 shown in FIG. 10. The area surrounded by dashed lines 105 and 106, which was an area with excessive cumulative energy density without correction, changes from red to yellow-green or green after applying correction A, indicating a decrease in cumulative energy density. Furthermore, the area surrounded by dashed lines 107 and 108, which was an area with insufficient cumulative energy density without correction, remains unchanged from dark blue, but the area of ​​the dark blue area has expanded, indicating a further decrease in cumulative energy density. Although it is difficult to see in FIG. 13, applying correction A reduces the cumulative energy density over the entire printing surface (scanning lines along the contour line and scanning lines within the contour line).

[0105] FIG. 14 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (with second correction). On the display screen 120 shown in FIG. 14, an accumulated energy density distribution display area 121 displays an accumulated energy density distribution when correction B (an example of a second correction) is applied to the modeling conditions.

[0106] The area surrounded by dashed lines 105 and 106, which was an area with excess cumulative energy density without correction, changes from red to orange or yellow after correction B is applied, indicating a decrease in cumulative energy density. Furthermore, the area of ​​the dark blue area surrounded by dashed lines 107 and 108, which was an area with insufficient cumulative energy density without correction, and the dark blue area below it, has expanded, indicating a further decrease in cumulative energy density. Furthermore, by applying correction B, the cumulative energy density is decreased overall within the contour of the octagonal cross-sectional shape. For example, a new decrease in cumulative energy density is observed in dashed line area 141, located inside the diagonal contour, and on the left side of the cross-sectional shape.

[0107] FIG. 15 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (with first and second corrections). 15, correction A and correction B are selected simultaneously. A cumulative energy density distribution display area 121 displays a cumulative energy density distribution when correction A and correction B (examples of the first and second corrections) are applied to the modeling conditions. In the cumulative energy density distribution, the position of a dashed line portion 151 corresponds to the position of the dashed line portion 141 shown in FIG.

[0108] The areas surrounded by dashed lines 105 and 106, which were areas of excessive cumulative energy density without correction, change from red to orange or yellow by applying corrections A and B. By applying corrections A and B, the operator can visually confirm that the color of the area of ​​interest has changed from red to the same color as in the case of correction A alone or to a color with a slight yellow tint, and can confirm that the cumulative energy density has decreased. In this case, it can be seen that by applying corrections A and B, the cumulative energy density has decreased compared to the case of no correction, but the value is still higher than in the case of correction A alone.

[0109] Furthermore, by applying corrections A and B, the area of ​​the dark blue portion surrounded by dashed lines 107 and 108, which was an area of ​​insufficient cumulative energy density without correction, clearly expanded, and it can be seen that the cumulative energy density was further reduced compared to the case of only correction B. However, it is also considered that there is not a significant difference in the overall cumulative energy density distribution within the outline of the octagonal cross-sectional shape between the case where correction B is applied and the case where corrections A and B are applied.

[0110] In the second embodiment described above, it is possible to visually grasp the cumulative irradiation energy density distribution on the printing surface when the energy beam is scanned along the planned beam scanning path by applying correction of the printing conditions. The cumulative irradiation energy density distribution on the printing surface reflects the printing conditions (beam scanning conditions, beam irradiation conditions), such as the energy density distribution of the beam cross section, the scanning speed, the scanning interval, and the beam scanning path.

[0111] Furthermore, excess or insufficiency of cumulative energy density on the printing surface (uneven distribution of cumulative energy density) due to inappropriate correction of printing conditions is one of the causes of defects due to excessive or insufficient melting. Therefore, it is desirable to use the printing data creation device according to this embodiment to detect excess or insufficient cumulative energy density on the printing surface on CAM software. Then, based on the detection results, designing printing conditions to prevent defects and print good products can contribute to reducing the yield of molded objects and improving manufacturing efficiency.

[0112] <Third embodiment> A modeling data creation device according to a third embodiment of the present invention will be described with reference to Figures 16 to 18. The basic configuration of the modeling data creation device according to the third embodiment is the same as the configuration of the modeling data creation device 30 according to the first embodiment (Figures 4 to 6).

[0113] The modeling data creation device according to the third embodiment is an example that displays the time change of the cumulative energy density distribution on the modeling surface according to the order of energy beam scanning. The display screen is provided with a user interface that has a function (e.g., a progress bar) that shows the time elapsed during modeling of one layer, a function that allows the user to freely change the elapsed time from the start of beam scanning forward or backward, and a function that allows the user to turn automatic playback on or off.

[0114] FIG. 16 is a flowchart showing an example of a display process of the accumulated energy density distribution by the modeling data creating apparatus according to the third embodiment of the present invention. The flowchart of FIG. 16 differs significantly from the flowchart of FIG. 7 in the first embodiment in that it includes step S24B, which calculates the irradiation energy density taking into account the elapsed time since the start of beam scanning, step S41, which displays the elapsed time using a progress bar, and step S42, which checks whether or not there is a change in time. The operation of this flowchart is realized by the processor 60a (FIG. 6) reading and executing a program written in the storage unit 60b. The following description of the flowchart of FIG. 16 will focus on differences from FIG. 7, and redundant description will be omitted. This flowchart starts when the operator changes the elapsed time since the start of beam scanning on the screen or switches on automatic playback.

[0115] First, the display control unit 305 (FIG. 4) reads UI information (step S21), reads modeling data of the specified layer (step S22), and decomposes the scanning of the energy beam on the specified layer into operation elements (step S23).

[0116] Next, in the display control unit 305, the irradiation energy density calculation unit 503 calculates the irradiation energy density 510 for each micro-area corresponding to each of all display pixels at the specified display magnification based on the modeling conditions for each operating element for which beam scanning is completed between the start of beam scanning of the specified layer and time t (step S24B). In step S24B, the time at which the additive manufacturing process for the layer to be displayed starts is set to 0, and the time elapsed from time 0 is set to t. The initial value of t is set to 0.

[0117] Then, the irradiation energy density calculation unit 503 stores the irradiation energy density 510 (FIG. 5) of each minute region calculated for each operation element in a storage area secured for each minute region in the storage unit 60b (step S25).

[0118] Next, the display data generation unit 504 generates cumulative energy density distribution data (display data) from time 0 to time t of the specified layer from the irradiation energy density 510 for each microregion of the specified layer from time 0 to time t stored in the storage unit 60b, and outputs the data to the display device 42 (step S26). As a result, the cumulative energy density distribution of the layer specified by the operator up to time t for the pixels to be displayed is graphically displayed on the display device 42.

[0119] Here, the display data generating unit 504 sets the progress bar 175 (see FIG. 17), which indicates the time elapsed ratio with respect to the time T (see FIG. 17, which will be described later) required until the beam scanning included in the display data is completed, to a state corresponding to time t (step S41). For example, the length of the progress bar 175 (a bar-shaped object) is displayed at a position corresponding to time t. The processing of step S41 may be performed in parallel with step S26, or may be included in the processing of step S26.

[0120] Next, the irradiation energy density calculation unit 503 determines whether or not the time t has changed (step S42), and if the time t has changed (YES determination in step S42), the process returns to step S24B. Then, based on the changed time t, the irradiation energy density calculation unit 503 calculates the irradiation energy density 510 for each microregion for each operation element for which beam scanning will be completed by the time t. The display control unit 305 repeats the processes of steps S24B to S41 until the time arrives when beam scanning for all layers to be displayed is completed (time T has elapsed).

[0121] For example, during automatic playback (described later), the irradiation energy density calculation unit 503 increases the time t by an arbitrary fixed increment (Δt). The irradiation energy density calculation unit 503 calculates the irradiation energy density 510 for each microregion for each operation element that completes beam scanning between time 0 and the changed time (t+Δt). Furthermore, for example, if the operator operates the jog dial 174 (see FIG. 17) to change the time, the irradiation energy density calculation unit 503 returns to step S24B regardless of whether automatic playback is in progress or not. The irradiation energy density calculation unit 503 increases or decreases the value of the time t by an amount corresponding to the operation amount (rotation angle) of the jog dial 174, and executes the process of step S24B.

[0122] If the time t has not changed in step S42 (NO in step S42), the process ends.

[0123] By the above-described operation of the modeling data creation device (display control unit 305), the cumulative energy density distribution of the designated layer at time t after the start of beam scanning is graphically displayed.

[0124] [Display screen showing cumulative energy density distribution reflecting time changes] Next, an example of a display screen showing the time change of the cumulative energy density distribution according to the third embodiment of the present invention will be described with reference to FIGS.

[0125] FIG. 17 is a diagram (part 1) showing an example of a display screen showing the cumulative energy density distribution in the middle of energy beam scanning on a certain layer. 17, a display screen 170 (an example of a user interface) has an accumulated energy density distribution display area 171, an auto play button 172, a stop button 173, a jog dial 174, and a progress bar 175. As an example, a user interface (not shown) for confirming with the operator whether or not to transition to the time change mode is displayed on the display screen 100 shown in FIG. 10. Then, when transition to the time change mode is selected, the display data generation unit 504 displays the display screen 170 shown in FIG. 17.

[0126] The cumulative energy density distribution display area 171 (an example of a display function) displays the cumulative energy density distribution for a specified layer of the three-dimensional shape data. The types of display include automatic playback display and time-specified display. automatic When displaying by playback, the distribution of irradiation energy density is displayed as a moving image in accordance with the order of beam scanning, allowing visual confirmation of the time-dependent change in the cumulative energy density distribution. When displaying by specifying a time, the cumulative energy density distribution from time 0 to time t at the specified time t is displayed. This allows you to visually check the cumulative energy density distribution at the time you want to focus on.

[0127] Fig. 17 and Fig. 18, which will be described later, show, as an example, a display state in the middle of energy beam scanning of one layer in the same layer (for example, the 301st layer) as Fig. 10. The example in Fig. 17 shows the stage where beam scanning starts from position S, and beam scanning (vector scanning) along the contour line has reached position P1.

[0128] The automatic playback button 172 (an example of a selection function) is a button used for automatic playback of the cumulative energy density distribution. The operator can select whether or not to perform automatic playback using the automatic playback button 172. When the operator presses the automatic playback button 172, the display control unit 305 automatically plays back the cumulative energy density distribution as a video in accordance with the order of beam scanning. During automatic playback, the automatic playback button 172 lights up or is highlighted so that it can be visually confirmed that automatic playback is in progress. The display screen 170 shown in FIG. 17 is an example of a display of a cumulative energy density distribution by automatic playback. Whether or not to perform automatic playback when this screen is displayed may be set in advance. The display screen 170 according to this embodiment is a user interface that allows the operator to select automatic playback or display by specifying a time.

[0129] The stop button 173 is a button for stopping the automatic reproduction of the cumulative energy density distribution. When the operator presses the stop button 173, the display control unit 305 stops the automatic reproduction of the cumulative energy density distribution. While the automatic reproduction is stopped, the stop button 173 is lit or highlighted so that it can be visually confirmed that the automatic reproduction is stopped. In this state, when the stop button 173 is pressed again, the light or highlighting disappears, and from that point on, the automatic reproduction is resumed or becomes possible.

[0130] The jog dial 174 (an example of a time change function) is a rotary operation unit that can freely move the elapsed time (time t) since the start of beam scanning in the display of the cumulative energy density distribution. The cumulative energy density distribution display area 171 displays the cumulative energy density distribution of a specified layer over the elapsed time operated with the jog dial 174. When the jog dial 174 is rotated clockwise, the time t at which the cumulative energy density distribution is displayed advances according to the amount of operation (rotation angle). When the jog dial 174 is rotated counterclockwise, the time t at which the cumulative energy density distribution is displayed moves backward according to the amount of operation (rotation angle). Note that although a rotary operation unit is used for the time change function, a linear slider, for example, may also be used.

[0131] The progress bar 175 (an example of a time elapsed rate display function) shows the rate of time elapsed relative to the time required from the start to the completion of beam scanning on a specified layer. The length of the hatched bar-shaped object on the progress bar 175 is displayed at a position corresponding to time t. Let us assume that the time required from the start to the completion of beam scanning on a specified layer (hereinafter referred to as "beam scanning time") is T. The position of time t relative to the beam scanning time T indicates the rate of time elapsed relative to the beam scanning time T. For example, the operator can intuitively grasp how far the beam scanning has progressed on the printing surface or how much time is remaining until the beam scanning is completed. Note that the progress bar 175 is a bar-shaped object with a variable length, but it may also be a circle or other shape or display form.

[0132] FIG. 18 is a diagram (part 2) showing an example of a display screen showing the cumulative energy density distribution in the middle of the energy beam scan. The display screen 170 shown in Fig. 18 is an example of a display of a cumulative energy density distribution at a specified time, showing the stage in which the inside of the contour line is being raster scanned left and right. Position P2 is the irradiation position of the electron beam 15 at time t specified by the jog dial 174. Since the inside of the contour line is being raster scanned, the progress bar 175 indicates that time t is approaching the beam scanning time T. In this way, the operator can freely specify a desired time for the printing surface and check the cumulative energy density distribution at any time.

[0133] In the second embodiment described above, it is possible to visually grasp the time change in the cumulative irradiation energy density distribution on the surface to be built according to the scanning order when the energy beam is scanned along the planned beam scanning path. The cumulative irradiation energy density distribution on the surface to be built reflects the building conditions (beam scanning conditions, beam irradiation conditions), such as the energy density distribution of the beam cross section, the scanning speed, the scanning interval, and the beam scanning path.

[0134] As mentioned above, excess or deficiency of cumulative energy density (uneven distribution of cumulative energy density) on the build surface is one of the causes of defects due to excessive or insufficient melting. Here, more accurate quality evaluation may be possible by considering the cumulative energy density distribution together with the microscopic and short-term diffusion of heat.

[0135] For example, even if there is a minute region with a higher cumulative energy density, if the cumulative value of the irradiation energy density is the cumulative value of the irradiation energy density due to nearby beam scanning over a sufficient period of time, the instantaneous maximum energy density will not be very high. Therefore, it can be determined that the possibility of defects due to excessive melting will not be high. Therefore, by utilizing the modeling data creation device according to this embodiment and applying the modeling data creation device according to this embodiment to the first embodiment, the effects of the first embodiment can be further enhanced. For the same reason, when the modeling data creation device according to this embodiment is applied to the second embodiment, the effects of the second embodiment can also be further enhanced.

[0136] <Modification> As described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various other modifications and applications are possible as long as they do not deviate from the gist of the invention described in the claims.

[0137] For example, in the above embodiment, the modeling conditions include the beam scanning conditions and the beam irradiation conditions, but the present invention is not limited to this, and the modeling conditions may include at least one of the beam scanning conditions and the beam irradiation conditions. This also applies to the correction of the modeling conditions.

[0138] Furthermore, in the above embodiment, the beam scanning conditions include the beam scanning method, the distance between adjacent scanning lines, and the scanning speed, but the present invention is not limited to this, and the beam scanning conditions may include at least one of the beam scanning method, the distance between adjacent scanning lines, and the scanning speed.

[0139] Furthermore, in the above embodiment, the beam irradiation conditions include the beam current amount or beam intensity, and the beam size on the manufacturing surface, but the present invention is not limited to this, and the beam irradiation conditions may include at least one of the beam current amount, beam intensity, and beam size on the manufacturing surface. [Explanation of symbols]

[0140] 1...3D additive manufacturing system, 10...3D additive manufacturing device, 14...beam irradiation device, 15...electron beam, 16...powder coating device, 26...plate moving device, 30...modeling data creation device, 32...metal powder, 38...modeled object, 41...input device, 42...display device, 100...display screen, 101...accumulated energy density distribution display area, 102...layer number display area, 102a...layer number display field, 120...display screen, 121...accumulated energy density distribution display area, 122...correction information display area, 170...display screen, 171...accumulated energy density distribution display area, 172...auto play button, 173...stop button, 174...jog dial, 175...progress bar, 305...display control unit, 501...reading unit, 502...operation element decomposition unit, 503: Irradiation energy density calculation unit, 504: Display data generation unit

Claims

1. A modeling data creation device that creates modeling data for controlling a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating it with a beam to form an article, a display control unit that generates data indicating a distribution of irradiation energy density accumulated in the target layer by beam scanning on the target layer based on the modeling data, and outputs the data to a display device; the display control unit includes a user interface including a designation function for accepting designation of the target layer by an operator and a display function for displaying a distribution of irradiation energy density accumulated in the designated target layer; Furthermore, the display control unit has a function of applying a correction selected by an operator to the modeling data, and generating data indicating a distribution of irradiation energy density accumulated in the target layer by beam scanning on the target layer, based on the corrected modeling data, the display control unit has a user interface including a selection function that accepts a selection of the correction by an operator, and a display function that displays a distribution of irradiation energy density accumulated in the target layer based on the modeling data to which the selected correction has been applied, The selection function is a function that allows the operator to select whether to enable or disable each correction type. Modeling data creation device.

2. The display control unit generates data showing a time change in the distribution of the irradiation energy density accumulated in the target layer in accordance with the order of beam scanning. The modeling data creating device according to claim 1 .

3. The display control unit a selection function that allows an operator to select whether or not to display the distribution of irradiation energy density accumulated in the target layer as a moving image in accordance with the beam scanning sequence; a display function for displaying a distribution of irradiation energy density accumulated in the target layer; a user interface including When the selection function selects to display the moving image in accordance with the order of the beam scanning, the display function displays the distribution of the irradiation energy density accumulated in the target layer in accordance with the order of the beam scanning. The modeling data creating device according to claim 2 .

4. The display control unit a time change function that can change the elapsed time from the start of beam scanning in displaying the distribution of irradiation energy density accumulated in the target layer; a display function for displaying a distribution of irradiation energy density accumulated in the target layer; a user interface including The display function displays a distribution of the irradiation energy density accumulated in the target layer during the elapsed time operated by the time change function. The modeling data creating device according to claim 2 .

5. The user interface has a time elapsed rate display function that shows the time elapsed rate of the elapsed time relative to the time required from the start to the completion of beam scanning in the target layer. The modeling data creating device according to claim 4 .

6. The modeling data includes, as modeling conditions, information on the energy density distribution of the beam cross section in the target layer, the scanning speed, the scanning interval, and the beam scanning path. The modeling data creating device according to claim 1 .

7. A three-dimensional additive manufacturing system including: a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating it with a beam to form an article; and a modeling data creation device that creates modeling data for controlling the three-dimensional additive manufacturing device, The modeling data creation device includes: a display control unit that generates data indicating a distribution of irradiation energy density accumulated in the target layer by beam scanning on the target layer based on the modeling data, and outputs the data to a display device; the display control unit includes a user interface including a designation function for accepting designation of the target layer by an operator and a display function for displaying a distribution of irradiation energy density accumulated in the designated target layer; Furthermore, the display control unit has a function of applying a correction selected by an operator to the modeling data, and generating data indicating a distribution of irradiation energy density accumulated in the target layer by beam scanning on the target layer, based on the corrected modeling data, the display control unit has a user interface including a selection function that accepts a selection of the correction by an operator, and a display function that displays a distribution of irradiation energy density accumulated in the target layer based on the modeling data to which the selected correction has been applied, The selection function is a function that allows the operator to select whether to enable or disable each correction type. 3D additive manufacturing system.

8. A cumulative energy density distribution display method using a modeling data creation device that creates modeling data for controlling a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating it with a beam to form an article, comprising: A process of calculating, based on the modeling data, an irradiation energy density accumulated in the target layer by beam scanning on the target layer; generating data indicating a distribution of irradiation energy density accumulated in the target layer and outputting the data to a display device; the modeling data creation device includes a user interface including a designation function for accepting designation of the target layer by an operator, and a display function for displaying a distribution of irradiation energy density accumulated in the designated target layer; Furthermore, the modeling data creation device has a function of applying a correction selected by an operator to the modeling data, and generating data indicating a distribution of irradiation energy density accumulated in the target layer by beam scanning on the target layer, based on the corrected modeling data, the modeling data creation device includes a user interface including a selection function that accepts a selection of the correction by an operator, and a display function that displays a distribution of irradiation energy density accumulated in the target layer based on the modeling data to which the selected correction has been applied; The selection function is a function that allows the operator to select whether to enable or disable each correction type. Cumulative energy density distribution display method.

Images