Apparatus for creating modeling data, three-dimensional additive manufacturing method, and method for displaying cumulative energy density distribution

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 method for displaying accumulated energy density distribution. [Background technology]

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

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

[0004] The CAM software process in the modeling data creation device first cuts out the cross-sectional shapes of each layer at intervals of one layer's thickness from the input three-dimensional shape data. Next, the modeling conditions for melting the cross-sectional shapes of each layer are determined. 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] Incidentally, a laser or a charged particle beam (hereinafter, these will be referred to as "energy beams") is controlled to have a certain size on the printing surface (especially when the cross section is approximated as being circular, this is expressed by the diameter (radius or diameter)). However, the energy density distribution in the cross section of the energy beam on the printing surface is generally not uniform (uniform). There are multiple possible reasons why the energy density distribution of the beam cross section is non-uniform. For example, in addition to the fundamental reasons caused by the beam source such as the oscillator, cathode, or emitter, the influence of aberration when the beam passes through a lens present between the beam source and the printing surface, an aperture, a deflection device, etc., and foreign objects present near the beam path are possible. One of the simplest approximation methods for the energy density distribution of the cross section of the beam on the printing 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 printing surface with a finite (finite meaning neither infinitesimal nor infinitesimal) scanning point spacing or scanning line spacing, the cumulative energy density distribution on the printing 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 favorably melting and bonding the outermost surface of the powder bed in every small area within the melting target area, it is believed that the entire melting target area will be favorably melted, resulting in the formation of a good, defect-free model. If not, in small areas where the cumulative energy density is insufficient, the material powder will remain unmelted, increasing the possibility of forming a defective model. Also, in small areas where the cumulative energy density is excessive, defects such as voids due to overmelting or vaporization will occur, increasing the possibility of forming a defective model.

[0009] Given the above situation, there was a demand for a method to visually grasp the existence of microscopic areas on the modeling 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 modeling surface, as a method (means) for verifying and validating modeling data. [Means for solving the problem]

[0010] In order to solve the above problems, one embodiment of the modeling data creation device of the present invention is a modeling data creation device that creates modeling data to control a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating a beam to form an article, 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 on the target layer based on the modeling data, and outputs the data to a display device.

[0011] One embodiment of the present invention is a three-dimensional additive manufacturing system comprising a three-dimensional additive manufacturing device that melts the cross-sectional shape of each layer by irradiating it with a beam to form an object, and a modeling data creation device that creates modeling data for controlling the three-dimensional additive manufacturing device, and the modeling data creation device comprises a display control unit that generates data indicating the 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.

[0012] One embodiment of the present invention is a cumulative energy density distribution display method that 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 a beam to form an article, and includes a process of calculating the irradiation energy density accumulated in a target layer by beam scanning of the target layer based on the modeling data, and a process of generating data indicating the distribution of the irradiation energy density accumulated in the target layer and outputting the data to a display device. Effect of the Invention

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

[0014] [Figure 1] 1 is a diagram illustrating an example of the configuration of a three-dimensional additive manufacturing system according to a first embodiment of the present invention. [Diagram 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. [Diagram 3] 5 is a flowchart showing an example of a procedure of a processing operation of the three-dimensional additive manufacturing apparatus according to the first embodiment of the present invention. [Figure 4] 1 is a block diagram showing an example of the configuration of a modeling data creating apparatus according to a first embodiment of the present invention. [Diagram 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] 2 is a block diagram showing an example of the hardware configuration of a computer included in the modeling data creating apparatus according to the first embodiment of the present invention. FIG. [Figure 7] 5 is a flowchart showing an example of a display process of a cumulative energy density distribution by the modeling data creating device according to the first embodiment of the present invention. [Figure 8]FIG. 1 is a diagram showing a first example of a visual representation of a scanning path of a conventional energy beam. [Figure 9] FIG. 13 is a diagram showing a second example visually illustrating a scanning path of a conventional energy beam. [Figure 10] FIG. 2 is a diagram showing an example of a display screen showing a cumulative energy density distribution by the modeling data creating device according to the first embodiment of the present invention. [Figure 11] 13 is a flowchart showing an example of a display process of a cumulative energy density distribution by a modeling data creating device according to a second embodiment of the present invention. [Figure 12] FIG. 11 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (without correction) by the shaping data creating device according to the second embodiment of the present invention. [Figure 13] FIG. 11 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (with first correction) by the shaping data creating apparatus according to the second embodiment of the present invention. [Figure 14] FIG. 11 is a diagram showing an example of a display screen showing a cumulative energy density distribution including correction information (with second correction) by the shaping data creating apparatus according to the second embodiment of the present invention. [Figure 15] FIG. 11 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 shaping data creating apparatus according to the second embodiment of the present invention. [Figure 16] 13 is a flowchart showing an example of a display process of a cumulative energy density distribution by a modeling data creating device according to a third embodiment of the present invention. [Figure 17] FIG. 11 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. 13 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 PREFERRED EMBODIMENTS

[0015] Hereinafter, an example of a mode for carrying out the present invention (hereinafter referred to as an "embodiment") will be described with reference to the attached drawings. In this specification and the attached drawings, the same or similar components are given the same reference numerals, and duplicated explanations may be omitted or only differences may be described. 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. 1 to 3. FIG.

[0017] FIG. 1 is a diagram 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 modeling 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 is defined as the X direction, the depth direction in Fig. 1 as the Y direction, and the up-down direction in Fig. 1 as the Z direction. The X direction, Y direction, and Z direction are mutually orthogonal. Moreover, the X direction and Y direction are parallel to the horizontal direction, and the Z direction is parallel to the vertical direction.

[0019] As shown in FIG. 1, the three-dimensional additive manufacturing apparatus 10 mainly includes a vacuum chamber 12, a beam irradiation device 14, a powder coating device 16, a modeling plate 22, an inner base 24, and a plate moving device 26. The three-dimensional additive manufacturing apparatus 10 models an article (hereinafter also referred to as a "modeled object") by the above-mentioned powder bed fusion method. In this embodiment, the case where the beam irradiated to the surface of the powder layer is a charged particle beam, more specifically, an electron beam, is taken as an example for explanation. However, the beam is not limited to a charged particle beam, and may be, for example, a laser beam. When a laser beam is used, it is not necessary to evacuate the chamber.

[0020] The vacuum chamber 12 is a chamber for creating a vacuum state by evacuating the air inside the chamber with a vacuum pump (not shown). The vacuum chamber 12 corresponds to a modeling chamber that forms a space for modeling a three-dimensional object 38.

[0021] The beam irradiation device 14 is a device that irradiates the surface of the powder layer, i.e., the surface to be built, 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 has an electron gun that is a source of 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 modeling surface can be adjusted by the focusing lens. The deflection device is configured using a deflection coil, and deflects the electron beam 15 by a magnetic field generated by the deflection coil. Scanning of the electron beam 15 on the modeling surface is achieved by the deflection device.

[0023] The powder coating device 16 is a device that coats the metal powder 32, which is a raw material of the molded object 38, on the molding plate 22 to form a powder layer. The metal powder 32 is an example of a powder that is a raw material of the molded object 38. As an example, the powder coating device 16 has 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 on the molding plate 22 from one end side to the other end side of the inner base 24 to spread the metal powder 32. As a result, a powder layer is formed on the molding 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 molded by being stacked on the shaping plate 22. The shaping plate 22 is formed into a circular or angular shape in a plan view.

[0025] The inner base 24 is provided so as to be 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 outer dimensions larger than those of the shaping plate 22. For example, the inner base 24 moves vertically in a space below an opening formed in the center of a 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 lower surface of the inner base 24. The drive mechanism includes a motor and a power transmission mechanism (not shown), and moves the shaping plate 22 and the inner base 24 together with the shaft in the up-down direction by driving the power transmission mechanism using the motor as a drive source.

[0027] It should be noted that the 3D additive manufacturing apparatus 10 shown in FIG. 1 is merely 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 according to 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. In addition, the three-dimensional additive manufacturing device 10 may be configured to have each of the functions of the modeling data creation device 30 (see FIG. 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, in this specification, the creation of modeling data for controlling the operation of the beam irradiation device 14 will be described, and a description of the creation of other modeling data will be omitted.

[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), a RAM (Random Access Memory), a HDD (Hard Disk Drive), and an SSD (Solid State Drive). The control unit 11 comprehensively controls the operation of the three-dimensional additive manufacturing apparatus 10 by having the processor read out a program written in advance in the ROM into the RAM and execute it. The control unit 11 also controls the operation of the entire three-dimensional additive manufacturing apparatus 10 in accordance with modeling data, which will be described later. The beam irradiation device 14, the powder coating device 16, and the plate moving device 26 are connected to the control unit 11 as objects to be controlled.

[0032] The beam irradiation device 14 irradiates the electron beam 15 based on a control command given from the control unit 11. At that time, the control unit 11 controls the electron beam 15 via an electron gun, a focusing lens, and a deflection device, which are not shown. For example, the control unit 11 controls the beam current amount 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 a focusing lens. The spot size of the electron beam 15 is the size of the electron beam 15 on the modeling 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 moving speed of the electron beam 15.

[0033] The plate moving device 26 moves the shaping plate 22 and the inner base 24 based on a control command given from the control unit 11. The powder coating device 16 applies metal powder 32 onto the shaping plate 22 based on a control command given from 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 device] 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 modeling, the periphery of the modeling plate 22, except for the upper surface of the modeling plate 22, is covered with the metal powder 32. In addition, the upper surface of the modeling plate 22 is disposed at approximately the same height as the upper surface of the metal powder 32 spread on the 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 manufacturing plate 22 with the electron beam 15. As a result, the manufacturing plate 22 is heated to a temperature at which the metal powder 32 is pre-sintered.

[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 shaped by lamination.

[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 onto the shaping plate 22. At this time, the metal powder 32 is spread onto the shaping plate 22 to a thickness equivalent to ΔZ. As a result, a powder layer is formed on the shaping 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 preheats the powder layer on the building plate 22 by operating based on a control command given from the control unit 11 (step S4). In this preheating step S4, the powder layer is preheated to presinter the metal powder 32. The preheating step S4 is performed before the main sintering step S5, which will be described later. In this way, the preheating step performed before the main sintering step is also called a powder heat step. The powder layer includes an unsintered region where the unsintered metal powder 32 exists and a presintered region where the presintered 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 provisionally sintered as described above is melted and solidified by irradiation with the electron beam 15, thereby final sintering the metal powder 32 as a provisionally sintered body. In step S5, the control unit 11 sets the cross-sectional shape of each layer cut out from the three-dimensional shape data of the target object 38 as a melting target area, and controls the beam irradiation device 14 according to the molding data associated with the cross-sectional shape. As a result, the melting target area represented by the two-dimensional cross-sectional shape of the metal powder 32 on the molding plate 22 is melted by irradiation with the electron beam 15. The metal powder 32 melted by irradiation with the electron beam 15 solidifies after the electron beam 15 has passed. As a result, the first layer of the molded object is formed.

[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 modeling plate 22 and the inner base 24 by ΔZ.

[0042] (First pre-heating step) Next, the beam irradiation device 14 preheats the powder layer on the modeling plate 22 by operating based on a control command given by the control unit 11 (step S7). In this first preheating step S7, the powder layer that has been subjected to the main sintering step in the previous layer is preheated in preparation for spreading the metal powder 32 in the next layer. As a result, the powder layer is heated to such an extent that the metal powder 32 in the next layer is heated by heat conduction from the current layer and temporarily 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. In this way, the 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. As a result, on the shaping plate 22, the second layer of metal powder 32 is spread over the sintered body formed by the first layer of metal powder 32 to form a powder layer.

[0044] (Second pre-heating process) 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 described below. Therefore, this preheating step S9 is also called a powder heat step. In step S9, the beam irradiation device 14 operates in the same manner as in step S4 above, whereby the metal powder 32 forming the second powder layer 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 above, thereby forming the second layer of the 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 (NO verdict), 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 (YES verdict), the process ends at that point. By the above-described three-dimensional additive manufacturing process, the desired object 38 is obtained.

[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 shaping data creation device 30 includes an import unit 301, a shaping data creation unit 302, an output processing unit 303, shaping data 304, and a display control unit 305. An input device 41 (an example of an input unit) and a display device 42 (an example of an output unit) are connected to the display control unit 305.

[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, a 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, etc. 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 for transmitting and receiving information between the control unit 11 of the 3D additive manufacturing apparatus 10 and other information processing devices (not shown). The control unit 11 shown in Fig. 2 may 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 the three-dimensional shape data input to the shaping data creation device 30 via the communication I / F 60d, and outputs the data to the shaping 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 to be melted by irradiation of an energy beam (electron beam 15 in this specification) in each powder layer, i.e., the area to be melted. 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 modeling data creation unit 302 applies the modeling conditions to the cross-sectional shape to generate modeling data 304, and stores the modeling data 304 in the memory unit 60b (FIG. 6). This modeling data corresponds to modeling data (operation sequence program) for 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. The beam scanning conditions are conditions that are applied when the surface of the powder layer is scanned with an energy beam (electron beam 15 in this embodiment). The beam irradiation conditions are conditions that are applied when the surface of the powder layer is irradiated 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] The beam scanning conditions include the beam scanning method, the distance between adjacent scan lines (scan line interval), the scanning speed, etc. The beam scanning methods include raster scanning, vector scanning, random scanning, etc. Raster scanning is a method in which parallel scan lines are generated and the beam is scanned along the generated scan lines. Raster scanning is classified into one-way raster scanning and reciprocating raster scanning. Vector scanning is a method in which tree-ring-like scan lines are generated to match the contour lines that form the cross-sectional shape and the beam is scanned 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 amount of current of the charged particle beam, the beam size on the printing surface, etc. The amount of current 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 amount of current of the electron beam 15 corresponds to the amount of current of the charged particle beam. Also, the size (spot size) of the electron beam 15 on the printing surface corresponds to the beam size on the printing 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 printing 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 per unit time (e.g., W / cm 2 Energy density is defined as the energy of an energy beam projected onto a unit area over a period of time, so the longer the time the same area is projected onto it, the higher the energy density.

[0058] The modeling conditions are set taking into consideration the beam scanning method (vector scanning, raster scanning), scanning line interval, scanning speed, as well as the type of energy beam, irradiation energy (amount of current of the charged particle beam, intensity of the laser beam), beam size on the modeling surface, etc. Each manufacturer of 3D additive manufacturing equipment is conducting research into what specific modeling conditions should be applied to the cross-sectional shape, so an overview will be provided here and detailed explanations will be omitted.

[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 apparatus 10 by the above-mentioned method (for example, a method using a portable recording medium). When an article to be modeled is to be modeled by dividing it into, for example, 100 layers, modeling data 304 for 100 layers is provided to the three-dimensional additive manufacturing apparatus 10. The control unit 11 of the three-dimensional additive manufacturing apparatus 10 sequentially controls the operation of the entire three-dimensional additive manufacturing apparatus 10 in accordance with the modeling data 304 provided from the modeling data creation device 30.

[0060] The display control unit 305 generates display data indicating a distribution of irradiation energy density accumulated in each layer by beam scanning on each layer based on the modeling data 304 (hereinafter, referred to as "accumulated energy density distribution"), and outputs this display data to the display device 42 via the input / output I / F 60c. The display device 42 displays the accumulated 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 accumulated energy density distribution of the specified layer, and outputs it as display data. The display device 42 displays the accumulated 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] [Display control section configuration] Next, the configuration of the display control unit 305 included in the modeling data creating 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 creating 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 in a 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 to be 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, when a command is given to the deflection device for each beam irradiation, the decomposition unit is set to be point by point, and when a command is given to the deflection device for multiple beam irradiations (corresponding to one line) as one unit, the decomposition unit is set to be line by line. An example of one line is one side of a polygon forming a 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 modeling conditions. For example, the modeling conditions include the energy density distribution of the beam cross section (beam spot on the modeling surface), the scanning speed, the scanning point interval, and the beam scanning path. The scanning point interval is the interval (distance) between the irradiation positions in successive beam irradiations. From the scanning speed and the scanning point interval, the time that 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] Then, the irradiation energy density calculation unit 503 stores the irradiation energy density 510 calculated for the micro-area corresponding to each pixel for each operation element of the planned beam scanning path in the memory unit 60b. The irradiation energy density information is stored in a scalar value storage area secured for each micro-area corresponding to each pixel in the memory unit 60b, by adding it to the previous value. Therefore, in a micro-area where multiple beam spots overlap among the micro-areas, the irradiation energy density is integrated and stored. The integrated irradiation energy density corresponds to the accumulated energy density. Moreover, the accumulated energy density for each micro-area on the modeling surface corresponds to the accumulated energy density distribution on the modeling surface.

[0068] The display data generating unit 504 creates accumulated energy density distribution data on the printing surface by associating the accumulated energy density of the minute area corresponding to each pixel stored in the storage unit 60b with a shade, a hue, or an arbitrary color map. A visualization method in which an image is colored with a continuous change in color tone according to the high and low of the value of each point or area (accumulated energy density in the present invention) is also called a heat map. Then, the display data generating unit 504 outputs the accumulated energy density distribution data to the display device 42 as display data, and graphically displays the accumulated 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 device] 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. This flowchart starts processing 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 a layer number for displaying the cumulative energy density distribution. 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 specified 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 microregion 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 area calculated for each motion element in a memory area secured for each micro area 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 generating 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 shaping 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 scanning path of a conventional energy beam will be described with reference to FIGS. FIG. 8 is a diagram showing a visual example (part 1) of a conventional energy beam scanning path. FIG. 9 is a diagram showing a second example visually illustrating a scanning path of a conventional energy beam.

[0076] When there is an excess or deficiency in the cumulative energy density distribution on the modeling surface, the melting target area of ​​the powder layer (e.g., the cross section of the model) is not melted well. An example of an area where this is likely to occur is the area along the line connecting the end points of adjacent scanning lines when raster scanning an energy beam. In this area, the envelope of the cumulative energy density distribution has a jagged shape (step-like), and the cumulative energy density decreases in the minute areas corresponding to the depressions, increasing the possibility of defects occurring due to insufficient melting of the powder and remaining powder.

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

[0078] In the 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 line of an octagonal cross-sectional shape, and multiple parallel scanning lines within the contour line. In Fig. 8, dashed lines 81 and 82 are areas where the cumulative energy density may be too high, and dashed lines 83 and 84 are 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 distribution from adjacent scanning lines, and therefore it is not possible to confirm whether the accumulated irradiation energy density when the energy beam is scanned over the modeling surface is within a range sufficient to produce a good model in every minute area.

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

[0081] For the same reason, when a defect is found in the modeled object by inspection after modeling, it is difficult to determine or identify the cause, whether it is due to the design of the energy beam scanning path or due to other causes. For example, other causes include defects in the beam irradiation device 14 of the 3D additive manufacturing device or other mechanical operations, defects in the material powder, etc. 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 accumulated 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 accumulated energy density distribution by the modeling data creating device 30. As shown in FIG. 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 has printing data for a plurality of 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] A layer number display field 102a is provided in the layer number display area 102 (an example of a designation function). The operator can confirm which layer the currently displayed cumulative energy density distribution is from by the layer number displayed in the layer number display field 102a. The layer number display field 102a is also a field for the operator to designate the layer number he or she wishes to display. The operator can input the layer number he or she wishes to display in the layer number display field 102a by operating the input device 41. After the operator inputs the layer number, the display control unit 305 updates the display by pressing the update button 103.

[0085] The accumulated energy density distribution display area 101 (an example of a display function) displays the accumulated energy density distribution for a specified layer of the three-dimensional shape data. The accumulated energy density distribution is displayed in shades, hues, or an arbitrary color map according to the value of the accumulated energy density. For example, the colors are set in order of increasing accumulated energy density in stages, specifically, red, orange, yellow, yellow-green, green, blue, purple, and black, with thresholds determined. This allows the operator to check the uniformity of the accumulated 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 modeling data is displayed in the cumulative energy density distribution display area 101. The cross-sectional shape of the 301st layer modeling data has an octagonal beam scanning path (contour line). The 301st layer 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 the dashed line portions 105 and 106 correspond to the positions of the dashed line portions 81 and 82 shown in FIG. 8. Moreover, the positions of the dashed line portions 107 and 108 correspond to the positions of the dashed line portions 83 and 84 shown in FIG. 8.

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

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

[0089] Excess or deficiency of the accumulated energy density on the modeling surface (uneven distribution of the accumulated energy density) caused by uneven density of the beam scanning path is one of the causes of defects due to excessive melting or insufficient melting. Therefore, it is desirable to use the modeling data creation device 30 according to this embodiment to detect (visually grasp) the presence of minute areas on the modeling surface where the accumulated energy density is excessive or insufficient on the CAM software. Then, based on the detection results, modeling conditions for preventing the occurrence of defects and forming good products can be designed, which can contribute to reducing the decrease in the yield of models 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 Fig. 11 to Fig. 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 (Figs. 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 modeled object, is applied to the calculation of the beam energy, and the cumulative energy density distribution on the modeling surface is displayed. That is, the cumulative energy density distribution on the modeling surface is displayed after applying correction to the modeling conditions of the modeling data. 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 is significantly different from the flowchart in FIG. 7 in the first embodiment in that it includes step S24A for calculating the irradiation energy density by applying correction 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 required to reproduce various corrections of the modeling conditions performed by the three-dimensional additive manufacturing apparatus 10. In the following, the flowchart in FIG. 11 will be described focusing on the differences from FIG. 7, and overlapping explanations will be omitted. 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 breaks down the scanning of the energy beam on the specified layer into operation elements (step S23).

[0094] Next, the irradiation energy density calculation unit 503 in the display control unit 305 calculates the irradiation energy density 510 for each micro-area corresponding to each display pixel at the specified display magnification based on the modeling conditions for all the operation elements (step S24A). In step S24A, the reading unit 501 receives, as UI information, a 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 an 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 for locally increasing the scanning speed of the relevant portion in order to compensate for the variation in the degree of diffusion of thermal energy to the laminated lower layer of the powder bed (correction A in FIG. 13). Another example is a correction for locally increasing the scanning speed in such a place 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 microregion calculated for each motion element in a storage area secured for each microregion in the storage unit 60b (step S25).

[0097] Next, the display data generating 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 of the pixels to be displayed, is graphically displayed on the display device 42.

[0098] By the above-described operation of the shaping data creating apparatus (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 accumulated 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 accumulated 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 an 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 to enable or disable each type of correction. The displayed types of correction are corrections that can be performed by the 3D additive manufacturing apparatus 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 application. After the operator inputs the correction information, the display control unit 305 updates the display by pressing the update button 123.

[0102] The accumulated energy density distribution display area 121 (an example of a display function) displays the accumulated 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 accumulated energy density distribution of the layer specified in the layer number display field 102a in the first embodiment is displayed in the accumulated 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 the correction information (with the first correction). On a display screen 120 shown in FIG. 13, an accumulated energy density distribution display area 121 displays an accumulated energy density distribution in a case where correction A (an example of a first correction) is applied to the modeling conditions.

[0104] In the cumulative energy density distribution, the positions of the dashed line portions 105, 106, 107, and 108 correspond to the positions of the dashed line portions 105, 106, 107, and 108 shown in FIG. 10. The portion surrounded by the dashed line portions 105 and 106, which was a cumulative energy density excess region without correction, changes from red to yellow-green or green by applying correction A, and it can be seen that the cumulative energy density has decreased. In addition, the portion surrounded by the dashed line portions 107 and 108, which was a cumulative energy density deficiency region without correction, remains the same as dark blue, but the area of ​​the dark blue portion has expanded, and it can be seen that the cumulative energy density has further decreased. Although it is difficult to see in FIG. 13, by applying correction A, the cumulative energy density has decreased 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 in a case where correction B (an example of a second correction) is applied to the modeling conditions.

[0106] It can be seen that the area surrounded by dashed lines 105 and 106, which was an area of ​​excess cumulative energy density without correction, changes from red to orange or yellow by applying correction B, and the cumulative energy density has decreased. In addition, the area of ​​the dark blue area surrounded by dashed lines 107 and 108, which was an area of ​​insufficient cumulative energy density without correction, and the dark blue area below it, has expanded, and the cumulative energy density has further decreased. Note that by applying correction B, the cumulative energy density has decreased overall within the contour of the octagonal cross-sectional shape. For example, a new decrease in cumulative energy density can be seen in dashed line portion 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 at the same time. A cumulative energy density distribution when correction A and correction B (examples of the first and second corrections) are applied to the modeling conditions is displayed in a cumulative energy density distribution display area 121. 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. 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 slightly more yellowish by applying corrections A and B, and can confirm that the cumulative energy density has decreased. In this case, it can be seen that the cumulative energy density has decreased by applying corrections A and B compared to the case of no correction, but is still a higher value than the case of correction A alone.

[0109] In addition, 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 increases, and it is found that the cumulative energy density is further reduced compared to the case of only correction B. However, it is also considered that there is no significant difference in the overall cumulative energy density distribution within the contour line 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 modeling surface when the energy beam is scanned along the planned beam scanning path by applying correction of the modeling conditions. The cumulative irradiation energy density distribution on the modeling surface reflects, for example, the energy density distribution of the beam cross section, the scanning speed, the scanning interval, and the beam scanning path as the modeling conditions (beam scanning conditions, beam irradiation conditions).

[0111] In addition, excess or deficiency of the accumulated energy density on the modeling surface (unevenness of the accumulated energy density distribution) caused by the appropriateness of correction of the modeling conditions is one of the causes of defects due to excessive melting or insufficient melting. Therefore, it is desirable to detect excess or deficiency of the accumulated energy density on the modeling surface on the CAM software by utilizing the modeling data creation device according to this embodiment. Then, based on the detection results, modeling conditions for preventing the occurrence of defects and forming good products can be designed, which can contribute to reducing the decrease in the yield of 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 Fig. 16 to Fig. 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 (Figs. 4 to 6) according to the first embodiment.

[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 having a function to show the time lapse rate during modeling of one layer (e.g., a progress bar), a function to freely change the elapsed time from the start of beam scanning forward or backward, and a function to turn on / off automatic playback.

[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 in FIG. 16 is significantly different from the flowchart in FIG. 7 in the first embodiment in that it includes step S24B for calculating the irradiation energy density in consideration of the elapsed time from the start of beam scanning, step S41 for displaying the elapsed time by a progress bar, and step S42 for checking 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. In the following, the flowchart in FIG. 16 will be described focusing on the differences from FIG. 7, and overlapping descriptions will be omitted. This flowchart starts when the operator changes the elapsed time from 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 breaks down 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 elapsed time 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 microregion calculated for each motion element in a storage area secured for each microregion in the storage unit 60b (step S25).

[0118] Next, the display data generating 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 for the pixels to be displayed up to time t 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 described later) required to complete the beam scanning included in the display data, 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 process of step S41 may be performed in parallel with step S26, or may be included in the process of step S26.

[0120] Next, the irradiation energy density calculation unit 503 judges whether or not the time t has been changed (step S42), and if the time t has been changed (YES judgment 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 is completed by the time t. The display control unit 305 repeats the processes of steps S24B to S41 until the time arrives at which all beam scanning of the layer 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 constant increment (Δt). The irradiation energy density calculation unit 503 calculates the irradiation energy density 510 for each microregion for each operation element in which beam scanning is completed between time 0 and the changed time (t+Δt). Also, for example, when 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 equivalent 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 been changed in step S42 (NO in step S42), the process ends.

[0123] By the above-described operation of the modeling data creation device (the display control unit 305), the cumulative energy density distribution of the specified layer at the 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 a time change in accumulated 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 an energy beam scan 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 generating unit 504 displays the display screen 170 shown in FIG. 17.

[0126] The accumulated energy density distribution display area 171 (an example of a display function) displays the accumulated energy density distribution for a specified layer of the three-dimensional shape data. The types of display include display by automatic playback and display by time specification. In the case of free-running display, the distribution of the irradiation energy density is displayed as a moving image in accordance with the order of the beam scanning, allowing the time-dependent change in the cumulative energy density distribution to be visually confirmed. 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 a time of interest.

[0127] Fig. 17 and Fig. 18 described later show, as an example, a display state in the middle stage of energy beam scanning of one layer in the same layer as Fig. 10 (e.g., the 301st layer). 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 play button 172 (an example of a selection function) is a button used for automatic play of the accumulated energy density distribution. The operator can select whether or not to perform automatic play by using the automatic play button 172. When the operator presses the automatic play button 172, the display control unit 305 automatically plays the accumulated energy density distribution as a video in accordance with the order of beam scanning. During automatic play, the automatic play button 172 is lit or highlighted so that it can be visually confirmed that automatic play is in progress. The display screen 170 shown in FIG. 17 is an example of a display of the accumulated energy density distribution by automatic play. Whether or not to perform automatic play 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 play or display by specifying a time.

[0129] The stop button 173 is a button for stopping the automatic reproduction of the accumulated energy density distribution. When the operator presses the stop button 173, the display control unit 305 stops the automatic reproduction of the accumulated 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 lighting or highlighting disappears, and the automatic reproduction is resumed or becomes possible from that point.

[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) from the start of beam scanning in the display of the accumulated energy density distribution. The accumulated energy density distribution display area 171 displays the distribution of the accumulated energy density of a specified layer during the elapsed time operated with the jog dial 174. When the jog dial 174 is rotated clockwise, the time t at which the accumulated 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 accumulated energy density distribution is displayed moves backward according to the amount of operation (rotation angle). Although a rotary operation unit is used for the time change function, for example, a linear slider may be used.

[0131] The progress bar 175 (an example of a time lapse rate display function) indicates the time lapse rate with respect 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. The time required from the start of beam scanning on a specified layer to the completion of beam scanning (hereinafter referred to as "beam scanning time") is assumed to be T. The position of time t relative to the beam scanning time T indicates the time lapse rate with respect to the beam scanning time T. For example, the operator can intuitively grasp how far the beam scanning has progressed on the modeling surface or how much time is left until the beam scanning is completed. Although the progress bar 175 is a bar-shaped object with a variable length, it may 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. 18 is an example of a display of a cumulative energy density distribution by time specification, showing the stage where the inside of the contour line is 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 it is the stage where the inside of the contour line is raster scanned, the progress bar 175 indicates that the 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 above-described second embodiment, it is possible to visually grasp the time change of the cumulative irradiation energy density distribution on the modeling surface 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 modeling surface reflects the modeling 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 the cumulative energy density on the molded surface (uneven distribution of the cumulative energy density) is one of the causes of defects due to excessive or insufficient melting. Here, more accurate quality evaluation may be possible by taking into account the cumulative energy density distribution and the microscopic and short-time diffusion of heat.

[0135] For example, even if there is a minute region with a relatively high cumulative energy density, if it is the cumulative value of the irradiation energy density by nearby beam scanning with a sufficient time left, the instantaneous maximum energy density will not be so high. Therefore, it can be determined that the possibility of defects caused by 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 effect of the first embodiment can be further improved. Also, for the same reason, when the modeling data creation device according to this embodiment is applied to the second embodiment, the effect of the second embodiment can be further improved.

[0136] <Modification> As described above, the present invention is not limited to the above-described embodiment, and it goes without saying that various other modified examples and application examples are possible without departing 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] In addition, 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] In addition, in the above embodiment, the beam irradiation conditions include the beam current amount or beam intensity, and the beam size on the printing 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 printing 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 a cross-sectional shape of each layer by irradiating the layer with a beam to create an article, comprising: 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. Modeling data creation device.

2. The display control unit generates data indicating a distribution of irradiation energy density accumulated in a target layer, the layer specified by an operator being the target layer. The modeling data creating apparatus according to claim 1 .

3. The display control unit is A designation function for accepting designation of the target layer by an operator; A display function for displaying the distribution of the irradiation energy density accumulated in a specified layer; It has a user interface including The modeling data creating apparatus according to claim 2 .

4. The display control unit applies a correction selected by an operator to the shaping data, and generates data indicating a distribution of irradiation energy density accumulated in the target layer by beam scanning on the target layer, based on the corrected shaping data. The modeling data creating apparatus according to claim 1 .

5. The display control unit is A selection function that accepts a correction selection by an operator; A display function for displaying a distribution of irradiation energy density accumulated in the target layer based on the modeling data to which the selected correction has been applied; It has a user interface including The modeling data creating apparatus according to claim 4 .

6. The selection function for accepting the selection of correction by the operator is a function that allows the operator to select whether to enable or disable each correction type. The modeling data creating apparatus according to claim 5 .

7. The display control unit generates data showing a time change in a distribution of the irradiation energy density accumulated in the target layer according to a sequence of beam scanning. The modeling data creating apparatus according to claim 1 .

8. The display control unit is A selection function that allows an operator to select whether or not to display a moving image of the distribution of the irradiation energy density accumulated in the target layer in accordance with the sequence of beam scanning; A display function for displaying a distribution of the irradiation energy density accumulated in the target layer; A user interface including When the selection function selects to display the moving image according to the sequence of the beam scanning, the display function displays the distribution of the irradiation energy density accumulated in the target layer according to the sequence of the beam scanning. The modeling data creating apparatus according to claim 7 .

9. The display control unit has a time change function that can operate the elapsed time from the start of beam scanning in the display of the distribution of the accumulated irradiation energy density; A display function for displaying a distribution of irradiation energy density accumulated in the target layer, 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 apparatus according to claim 7 .

10. a time lapse rate display function that indicates a time lapse rate of the elapsed time relative to the time required from the start to the completion of the beam scanning in the target layer; The modeling data creating apparatus according to claim 8 or 9.

11. 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 apparatus according to claim 1 .

12. A three-dimensional additive manufacturing system including: a three-dimensional additive manufacturing device that melts a cross-sectional shape of each layer by irradiating the layer 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. 3D additive manufacturing system.

13. A method for displaying a cumulative energy density distribution by a modeling data creation device that creates modeling data for controlling a three-dimensional additive manufacturing device that melts a cross-sectional shape of each layer by irradiating the layer with a beam to form an article, comprising: A process of calculating an irradiation energy density accumulated in a target layer by beam scanning on the target layer based on the modeling data; generating data indicating a distribution of the irradiation energy density accumulated in the target layer and outputting the data to a display device. A method for displaying cumulative energy density distribution.

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