Design support apparatus and design support method

Abstract

To provide a design support apparatus capable of realizing appropriate design support.SOLUTION: This invention is applied to a three-dimensional modeling system 100 including a modeling apparatus 110 for producing a powder compact 32 and a defatting and sintering furnace 120 for producing a three-dimensional modeled object 40 by defatting and sintering the powder compact 32. A design support apparatus 200 is provided with: an input unit 210 for inputting a target shape of the three-dimensional modeled object 40 and a three-dimensional coordinate position in a modeling tank 320 where the powder compact 32 is formed; and a shape determination unit 260 for determining a shape of the powder compact 32 based on the target shape, the three-dimensional coordinate position, and shrinkage factor functions SFx, SFy, and SFz representing shrinkage ratios in the three-dimensional coordinate axis directions.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a design support device and a design support method. [Background technology]

[0002] The following Patent Document 1 describes technology related to a binder jet molding device, a so-called 3D printer. Paragraph 0060 of the document states, "Therefore, the molding control unit 120 according to this embodiment is configured to control the molding control conditions so that the powder density in the powder layer 31 is biased so as to suppress deformation of the S body after sintering. Note that although the molding control unit 120 controls the powder density intentionally, this does not prevent the powder density from being uniform in areas other than the areas where the density is intentionally biased depending on the shape of the G body. Furthermore, please note that controlling the molding control conditions so that the powder density is biased does not mean that unintended bias in the powder density occurs as a result of inaction, which would increase deformation of the S body after sintering." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-187593 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned technology, there is a demand for realizing more appropriate design support. The present invention has been made in view of the above circumstances, and has as its object to provide a design support apparatus and a design support method that can realize appropriate design support. [Means for solving the problem]

[0005] In order to solve the above problems, the design support device of the present invention is applied to a three-dimensional modeling system that includes a modeling device that forms a powder layer in a modeling tank by distributing powder in a flat plate shape, and then ejects a modeling liquid onto a portion of the powder layer to form a modeling layer, thereby manufacturing a powder molded body by stacking the modeling layers, and a debinding and sintering furnace that manufactures a three-dimensional object by debinding and sintering the powder molded body, and is characterized by including an input unit that inputs the target shape of the three-dimensional object and the three-dimensional coordinate position in the modeling tank where the powder molded body is formed, and a shape determination unit that determines the shape of the powder molded body based on the target shape, the three-dimensional coordinate position, and a shrinkage rate function that represents the shrinkage rate in the three-dimensional coordinate axis direction. [Effects of the Invention]

[0006] According to the present invention, a three-dimensional object can be appropriately manufactured. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a block diagram of a three-dimensional object fabrication system according to a first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating the operating principle of the molding apparatus. [Figure 3] FIG. 1 is a diagram showing an example of a measurement sample. [Figure 4] FIG. 10 is a diagram showing an example of a measured shrinkage rate. [Figure 5] 10 is a flowchart of a design support routine executed by the design support device. [Figure 6] FIG. 1 is a block diagram of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Outline of the embodiment] In binder jet molding machines, a powder compact (also called a green body, G body, or sintered precursor) is first produced by mixing powder, which is the molding material, with a molding liquid (also called a binder). This powder compact is then debound and sintered to produce a three-dimensional object (also called a silver body, S body, or sintered body). The three-dimensional object is deformed so that its volume shrinks by approximately 50% compared to the powder compact.

[0009] Furthermore, the shape of a three-dimensional object may be distorted compared to the shape of a powder compact. One of the causes of this is gravity acting on the object during sintering. When gravity is the cause of the deformation, it may be possible to predict the deformation and take measures by performing a deformation analysis that takes into account the load caused by gravity.

[0010] Another cause of the distortion is the variation in powder density in the modeling tank. Variations in powder density can cause the shape of the three-dimensional object to deviate from the intended shape. Therefore, the embodiments described below are particularly intended to suppress distortion of the three-dimensional object due to variations in powder density.

[0011] [First embodiment] <Configuration of the first embodiment> (Overall composition) FIG. 1 is a block diagram of a three-dimensional modeling system 100 according to the first embodiment. The three-dimensional object fabrication system 100 includes a fabrication device 110, a degreasing and sintering furnace 120, a fabrication control device 150, and a design support device 200 (computer). The design support device 200 includes an input unit 210, a shrinkage rate calculation unit 220, a function storage unit 230, and a shape determination unit 260. Furthermore, the shape determination unit 260 includes a deformation analysis unit 262, a fabrication volume correction unit 264, and a shape data generation unit 266.

[0012] The molding device 110 is a binder jet molding device, and manufactures a powder molded body 32 by mixing a powder 20, which is a molding material, with a molding liquid 10. When shape data DG representing the shape of the powder molded body 32 is supplied, the molding control device 150 controls the molding device 110 so as to form the powder molded body 32 in accordance with the shape data DG.

[0013] The debinding and sintering furnace 120 debinds and sinters the powder compact 32 to manufacture a three-dimensional molded object 40. The three-dimensional molded object 40 is deformed so that its volume shrinks by approximately 50% compared to the powder compact 32. The molding liquid 10 is also called a binder. The powder compact 32 is also called a green body or a sintering precursor. The three-dimensional molded object 40 is also called a silver body or a sintered body. Details of the design support device 200 will be described later, along with its operation.

[0014] FIG. 2 is a schematic cross-sectional view illustrating the operating principle of the modeling apparatus 110. As shown in FIG. In FIG. 2, the modeling apparatus 110 includes a reciprocating mechanism 300 and a liquid ejection head 350 located in the upper right corner of the figure. In FIG. 2, the X and Y directions are two perpendicular directions on a horizontal plane, and the Z direction is the vertical direction. The reciprocating mechanism 300 is formed in a roughly rectangular parallelepiped frame shape with an open top and is capable of reciprocating along the X direction. The interior of the reciprocating mechanism 300 is partitioned by roughly rectangular partition plates 302 and 304 extending along the Y direction, thereby forming a supply tank 310, a modeling tank 320, and an excess powder collection tank 330. Therefore, the supply tank 310, the modeling tank 320, and the excess powder collection tank 330 all have a roughly rectangular parallelepiped frame shape with an open top. The level of the top surface of the reciprocating mechanism 300 is referred to as the top surface level Lt.

[0015] A supply stage 312 formed in a rectangular plate shape and movable up and down in the Z direction is provided inside the supply tank 310. Similarly, a modeling stage 322 formed in a rectangular plate shape and movable up and down in the Z direction is provided inside the modeling tank 320. In addition, the reciprocating mechanism 300 is equipped with rollers 12 that roll in the X direction along the upper surface level Lt.

[0016] Next, an operation for producing the powder compact 32 on the molding stage 322 will be described. (Step S1) First, the supply stage 312 is lowered to near the bottom end of the supply tank 310, and the space from the upper surface of the supply stage 312 to the upper surface level Lt is filled with powder 20. Furthermore, in the modeling tank 320, the upper surface of the modeling stage 322 is raised to the upper surface level Lt.

[0017] (Step S2) Next, the supply stage 312 is raised by a predetermined unit thickness dp, and the modeling stage 322 is lowered by the unit thickness dp. Then, the roller 12 is rolled along the upper surface level Lt from the left end of the supply tank 310 to the right end of the modeling tank 320. As a result, the portion of the powder 20 in the supply tank 310 that exceeds the upper surface level Lt moves to the modeling tank 320, forming a powder layer 31 above the modeling stage 322. At this time, the powder 20 spilled from the modeling tank 320 falls into the excess powder collection tank 330.

[0018] (Step S3) Next, the liquid ejection head 350 is moved so that it is positioned above the area where the powder molded body 32 is to be formed. When the modeling liquid 10 is ejected from the liquid ejection head 350 at the ejection position Ph, the powder layer 31 in the ejected area becomes the modeling layer 30, which is a mixture of the powder 20 and the modeling liquid 10.

[0019] (Step S4) Steps S2 and S3 are then repeated. Each time a repetition is made, a molding layer 30 is stacked, and the stacked molding layers 30 form a powder molded body 32. After the molding stage 322 reaches the lowest position Pe corresponding to the height of the powder molded body 32, a molding layer 30 is formed, and the powder molded body 32 is completed. Once the powder molded body 32 is formed, it is subjected to debinding and sintering processes in the debinding and sintering furnace 120 (see FIG. 1 ) as described above, and a three-dimensional molded object 40 is formed.

[0020] The configuration of the modeling apparatus 110 is not limited to the one described above. For example, a blade (not shown) can be used instead of the roller 12 described above to generate the powder layer 31. In addition, in the example shown in Fig. 2, the powder 20 is supplied from the supply tank 310 to the model-making tank 320, but instead, a hopper 84, shown by a dashed line, may be provided above the model-making tank 320, and the powder 20 may be supplied from the hopper 84 to the model-making tank 320.

[0021] Here, the process of forming the powder layer 31 in the modeling tank 320 will be further considered. As described above, the powder layer 31 is a rectangular plate-like layer having a unit thickness dp. When the roller 12 supplies the powder 20 from the supply tank 310 to the modeling tank 320, a hill-like layer 36, indicated by a dashed line, is formed at the left end of the upper surface of the modeling tank 320. The hill-like layer 36 has a height exceeding the unit thickness dp. As the roller 12 rolls left and right on the upper surface of the modeling tank 320, the hill-like layer 36 moves while deforming, and the powder layer 31 is formed.

[0022] Furthermore, when the powder 20 is supplied to the modeling tank 320 by the hopper 84, a hill-like layer 88, indicated by the dashed line, is formed below the hopper 84. The hill-like layer 88 also has a height exceeding the unit thickness dp. As the roller 12 rolls left and right on the top surface of the modeling tank 320, the hill-like layer 88 moves while deforming, forming the powder layer 31. The density of the powder 20 in the powder layer 31 tends to be higher at the positions where the hill-like layers 36, 88 are first formed compared to other positions.

[0023] <Operation of the First Embodiment> (Getting the shrinkage function) As described above, the three-dimensional object 40 (see FIG. 1) deforms so that its volume shrinks by approximately 50% compared to the powder compact 32. At this time, the shrinkage rates Sx, Sy, and Sz (not shown) in the X, Y, and Z directions are calculated by the following formulas. Shrinkage ratio = ((dimension before shrinkage) - (dimension after shrinkage)) / (dimension before shrinkage)

[0024] The shrinkage rates Sx, Sy, and Sz differ depending on the formation position of the powder molded body 32 in the manufacturing tank 320. Furthermore, the shrinkage rates Sx, Sy, and Sz in the X, Y, and Z directions generally also have different values. When the manufacturing stage 322 reaches the lowest position Pe of the manufacturing tank 320 (see FIG. 2), the coordinates of an arbitrary point in the X, Y, and Z directions are defined as x, y, and z.

[0025] Furthermore, the shrinkage rates in the X, Y, and Z directions corresponding to a given point on the powder compact 32 are functions of the coordinates x, y, and z. Therefore, the shrinkage rates in the X, Y, and Z directions can be expressed as Sx(x, y, z), Sy(x, y, z), and Sz(x, y, z). The shrinkage rates can be determined using a measurement sample 92, for example, as shown in FIG. 3.

[0026] FIG. 3 is a diagram showing an example of the measurement sample 92. As shown in FIG. In FIG. 3, the measurement samples 92 are a type of the powder compact 32 shown in FIG. 2 and are manufactured in the manufacturing tank 320. In the illustrated example, a total of 45 measurement samples 92 (5 × 3 × 3) are arranged at equal intervals along the X, Y, and Z directions. The coordinates x, y, and z of the center point of each measurement sample 92 in the X, Y, and Z directions are expressed as integers ranging from 1 to 5, 1 to 3, and 1 to 3, respectively. Each measurement sample 92 is cubic. These measurement samples 92 are manufactured in the manufacturing apparatus 110, and then debinding and sintering processes are performed in the debinding and sintering furnace 120 to form a sintered three-dimensional object 94. The user measures the dimensions of the measurement samples 92 before sintering and the dimensions of the sintered three-dimensional object 94 and inputs the results as sample information SI into the input unit 210 of the design support system 200.

[0027] The shrinkage ratio calculation unit 220 of the design support device 200 calculates the shrinkage ratios Sx, Sy, and Sz corresponding to each measurement sample 92 based on the dimensions of the measurement sample 92 and the three-dimensional object 94. In other words, it calculates discrete shrinkage ratios Sx, Sy, and Sz for the center point of each measurement sample 92.

[0028] Furthermore, the shrinkage ratio calculation unit 220 performs interpolation and noise removal on the calculated discrete shrinkage ratios Sx, Sy, Sz to calculate shrinkage ratio functions SFx, SFy, SFz that specify the shrinkage ratios Sx, Sy, Sz for the coordinates x, y, z over the entire modeling tank 320. The function storage unit 230 stores the calculated shrinkage ratio functions SFx, SFy, SFz.

[0029] FIG. 4 is a diagram showing an example of the actually measured shrinkage rates Sx, Sy, and Sz. That is, Figure 4 shows the coordinates of the measurement sample 92, the dimensions of the measurement sample 92 which is a powder compact, the dimensions of the three-dimensional object 94 obtained by sintering the measurement sample 92, and the shrinkage factors Sx, Sy, and Sz for both.

[0030] In the example of Figure 4, among the measurement samples 92 whose Z coordinate is "1," the maximum horizontal shrinkage rate is "15.31" at Sx(3,1,1). Also, among the measurement samples 92 whose Z coordinate is "1," i.e., at the same height, the minimum horizontal shrinkage rate is "12.61" at Sy(1,3,1). Then, the ratio of the two, "Sx(3,1,1) / Sy(1,3,1)," is "1.243."

[0031] The values ​​of these shrinkage factors Sx and Sy are approximately equal to the shrinkage factor functions SFx and SFy ​​for the same coordinates. Thus, the ratio of the minimum horizontal shrinkage factor to the maximum horizontal shrinkage factor for the same Z coordinate (i.e., the same height) of the shrinkage factor functions SFx, SFy, and SFz is generally 1.01 or greater. This ratio can also be 1.05 or greater, or 1.10 or greater, and can even be 1.20 or greater, as in the example shown in Figure 4.

[0032] (Design support processing) FIG. 5 is a flowchart of a design support routine executed by the design support device 200. 5, when the process proceeds to step S102 (input step), the user inputs the printing conditions PRC of the three-dimensional object 40 via the input unit 210. Here, the printing conditions PRC include the target shape of the three-dimensional object 40, process conditions, and printing position. The printing position is the x, y, z coordinates of each part of the three-dimensional object 40 in the printing tank 320. When manufacturing multiple three-dimensional objects 40, the user inputs the printing position for each three-dimensional object 40.

[0033] Next, when the process proceeds to step S104 (shape determination process), the deformation analysis unit 262 analyzes the deformed shape state for each modeling position with respect to the target shape, based on the shrinkage factor functions SFx(x,y,z), SFy(x,y,z), and SFz(x,y,z) for each coordinate x, y, and z of the modeling position. Next, when the process proceeds to step S106 (shape determination process), the modeling volume correction unit 264 performs volume correction for each modeling position, based on the shrinkage factor functions SFx(x,y,z), SFy(x,y,z), and SFz(x,y,z).

[0034] Next, when the process proceeds to step S108 (shape determination step), the shape data generation unit 266 creates shape data DG according to the printing position of each three-dimensional object 40. Therefore, even if the ideal shapes of multiple three-dimensional objects 40 are the same, the shape data DG will have slightly different content depending on the printing position of the three-dimensional object 40. This shape data DG is preferably in the form of a CAD drawing so that the user can modify it as needed. When the shape data DG is supplied to the printing control device 150 (see FIG. 1), the printing control device 150 controls the printing device 110 to form a powder molded body 32 in accordance with the shape data DG.

[0035] Through the above processing, the shape determination unit 260 creates shape data DG for the powder molded body 32 based on the contraction rate functions SFx, SFy, and SFz at the coordinates x, y, and z of each part of the three-dimensional object 40. That is, the shape determination unit 260 creates the shape data DG so that the volume of the powder molded body 32 is relatively large in regions where the contraction rate functions SFx, SFy, and SFz are large, and the volume of the powder molded body 32 is relatively small in regions where the contraction rate functions SFx, SFy, and SFz are small.

[0036] [Computer Configuration] 6 is a block diagram of the computer 980. The design support device 200 shown in FIG. 1 includes one or more computers 980 shown in FIG. 6, a computer 980 includes a CPU 981, a storage unit 982, a communication I / F (interface) 983, an input / output I / F 984, and a media I / F 985. Here, the storage unit 982 includes a RAM 982a, a ROM 982b, and an SSD (Solid State Drive) 982c. The communication I / F 983 is connected to a communication circuit 986. The input / output I / F 984 is connected to an input / output device 987. The media I / F 985 reads and writes data from a storage medium 988. The ROM 982b stores an IPL (Initial Program Loader) executed by the CPU, etc. The SSD 982c stores application programs, various data, etc. The CPU 981 executes application programs, etc. loaded from the SSD 982c to the RAM 982a, thereby realizing various functions. The interior of the design support device 200 shown in FIG. 1 is primarily a block diagram of functions realized by application programs and the like.

[0037] [Variations] The present invention is not limited to the above-described embodiment, and various modifications are possible. The above-described embodiment is an example for explaining the present invention in an easy-to-understand manner, and is not necessarily limited to an embodiment having all of the described configurations. Furthermore, other configurations may be added to the configurations of the above-described embodiment, and some of the configurations may be replaced with other configurations. Furthermore, the control lines and information lines shown in the figures are those considered necessary for explanation, and do not necessarily represent all control lines and information lines necessary in the product. In reality, it can be assumed that almost all configurations are interconnected. Possible modifications of the above-described embodiment include, for example, the following.

[0038] (1) The hardware of the design support device 200 in the above embodiment can be realized by a general-purpose computer. Therefore, the processes corresponding to the above-described block diagrams and flowcharts, as well as programs for executing the various processes described above, may be stored in a storage medium (a computer-readable storage medium on which a program is recorded) or distributed via a transmission path.

[0039] (2) In the above embodiment, the processes corresponding to the block diagrams and flowcharts, as well as the various other processes described above, are described as software processes using programs. However, some or all of these processes may be replaced with hardware processes using an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), etc.

[0040] (3) The various processes executed in the above embodiment may be executed by a server computer via a network (not shown), and the various data stored in the above embodiment may also be stored in the server computer.

[0041] [Effects of the embodiment] As described above, according to the embodiment, the design support device 200 includes an input unit 210 that inputs the target shape of the three-dimensionally molded object 40 and the three-dimensional coordinate position in the molding tank 320 where the powder molded body 32 is to be formed, and a shape determination unit 260 that determines the shape of the powder molded body 32 based on the target shape, the three-dimensional coordinate position, and shrinkage factor functions SFx, SFy, and SFz that represent the shrinkage factors in the three-dimensional coordinate axis directions. This allows for appropriate design support. In particular, it allows for the design of the powder molded body 32 that suppresses distortion of the three-dimensionally molded object due to variations in powder density.

[0042] Furthermore, it is preferable that the shrinkage ratio functions SFx, SFy, and SFz can also handle the case where the maximum horizontal shrinkage ratio at a given height of the modeling tank 320 is 1.01 times or more the minimum horizontal shrinkage ratio, thereby effectively suppressing distortion of the three-dimensional model caused by variations in powder density.

[0043] Furthermore, each powder layer 31 has a predetermined unit thickness dp, and it is preferable if the modeling apparatus 110 can also accommodate a case in which hilly layers 36, 88 higher than the unit thickness dp are formed in the modeling tank 320 and the hilly layers 36, 88 are pressed and leveled to form the powder layer 31. This makes it possible to effectively suppress distortion of the three-dimensional object due to variations in powder density, even when using a modeling apparatus 110 that can efficiently form the powder layer 31. [Explanation of symbols]

[0044] 10 Modeling fluid 20 powder 30 Modeling layer 31 Powder layer 32 Powder compacts 36,88 Hilly Formation 40 Three-dimensional sculpture 88 Hilly Formation 100 3D Modeling System 110 Modeling equipment 120 Degreasing and sintering furnace 200 Design support device (computer) 210 Input section 260 Shape determination unit 320 Modeling tank dp unit thickness SFx,SFy,SFz contraction rate functions S102 Step (input process) S104, S106, S108 steps (shape determination process)

Claims

1. The present invention is applied to a three-dimensional modeling system including a modeling device that forms a powder layer in a modeling tank by distributing powder in a flat plate shape, ejects a modeling liquid onto a part of the powder layer to form a modeling layer, and manufactures a powder molded body by stacking the modeling layers; and a degreasing and sintering furnace that manufactures a three-dimensional modeled object by degreasing and sintering the powder molded body, an input unit for inputting a target shape of the three-dimensional object and a three-dimensional coordinate position in the building tank where the powder molded body is formed; a shape determination unit that determines a shape of the powder compact based on the target shape, a three-dimensional coordinate position, and a shrinkage rate function that represents a shrinkage rate in a three-dimensional coordinate axis direction. A design support device characterized by:

2. The shrinkage rate function is a function in which the maximum horizontal shrinkage rate at a predetermined height of the modeling tank is 1.01 times or more the minimum horizontal shrinkage rate.

2. The design support device according to claim 1.

3. Each of the powder layers has a predetermined unit thickness, The molding apparatus forms a hill-like layer higher than the unit thickness in the molding tank, and presses and smooths the hill-like layer to form the powder layer.

3. The design support device according to claim 2.

4. The present invention is applied to a three-dimensional modeling system including a modeling device that forms a powder layer in a modeling tank by distributing powder in a flat plate shape, ejects a modeling liquid onto a part of the powder layer to form a modeling layer, and manufactures a powder molded body by stacking the modeling layers; and a degreasing and sintering furnace that manufactures a three-dimensional modeled object by degreasing and sintering the powder molded body, an input process of inputting a target shape of the three-dimensional object and a three-dimensional coordinate position in the building tank where the powder molded body is to be formed; a shape determination step of determining the shape of the powder compact based on the target shape, a three-dimensional coordinate position, and a shrinkage rate function representing a shrinkage rate in the three-dimensional coordinate axis direction, and causing a computer to execute the step. A design support method comprising:

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