Three-dimensional modeling device

Abstract

The present invention provides a three-dimensional modeling device that suppresses attachment of a powder material to a nozzle due to ejection of a solidification liquid. The three-dimensional modeling device of the present invention includes a modeling tank formed in a box shape having an opening portion in at least a portion, which houses a powder material; and an ejection device (70) disposed in a manner to face the opening portion of the modeling tank, which ejects a solidification liquid that solidifies the powder material toward the opening portion. The ejection device (70) has a plurality of nozzle rows (72) each composed of a plurality of nozzles (71) arranged in a first direction (X). The plurality of nozzles (71) are configured to each eject the solidification liquid, and in each nozzle row (72), the nozzles are arranged in the first direction (X) at a density of 1200 dpi or less. The plurality of nozzle rows (72) are arranged to be separated from each other by 5 mm or more in a second direction (Y) orthogonal to the first direction (X).

Description

TECHNICAL FIELD

[0001] The present application relates to a three-dimensional modeling device. BACKGROUND

[0002] In the past, a device has been known that forms a thin solidified layer having a desired cross-sectional shape by ejecting a solidification liquid to a powder material and stacks the solidified layer to produce a three-dimensional modeled object. For example, in Patent Literature 1, a three-dimensional modeling device is disclosed that has a modeling tank in which a modeled object is modeled, a powder transfer unit that supplies a powder material to the modeling tank, and an ejection head that ejects a solidification liquid for solidifying the powder material.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2018-126974 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] In a powder solidification type three-dimensional modeling device described in Citation Literature 1, for example, powder material in the modeling tank sometimes flies due to ejection of the solidification liquid. If the flying powder material adheres to a nozzle of the ejection head, the adhered powder material can be solidified by the solidification liquid. If the powder material adhering to the nozzle is solidified, adverse situations such as clogging of the nozzle or bending of the flight direction of the solidification liquid can occur.

[0008] The present application has been achieved in view of the above-described problems, and aims to provide a three-dimensional modeling device that suppresses powder material from adhering to a nozzle due to ejection of a solidification liquid.

[0009] TECHNICAL SOLUTION FOR SOLVING THE PROBLEMS

[0010] A first three-dimensional modeling device disclosed herein has a modeling tank that is formed in a box shape having an opening portion in at least a part and that houses a powder material, and an ejection device that is disposed in a manner to face the opening portion of the modeling tank and that ejects a solidification liquid that solidifies the powder material toward the opening portion. The ejection device has a plurality of nozzle rows each of which is constituted by a plurality of nozzles arranged in a prescribed first direction. The plurality of nozzles are configured to eject the solidification liquid respectively, and in each of the plurality of nozzle rows, the nozzles are arranged at a density of 1200 dpi or less in the first direction. The plurality of nozzle rows are arranged to be separated from each other by 5 mm or more in a second direction orthogonal to the first direction.

[0011] According to the inventor's insight, if the density of the plurality of nozzles in the nozzle row of the three-dimensional modeling apparatus is set to be below a certain degree, and the plurality of nozzle rows are arranged at a distance of more than a certain degree apart, the scattering of the powder material in the modeling tank caused by the ejection of the solidification liquid can be suppressed. As a result, the attachment of the powder material to the nozzles is suppressed. In the above-described first three-dimensional modeling apparatus, since the density of the plurality of nozzles in the nozzle row is set to be 1200 dpi or less, and the plurality of nozzle rows are arranged at a distance of 5 mm or more apart from each other, the attachment of the powder material to the nozzles due to the ejection of the solidification liquid can be suppressed.

[0012] In addition, the second three-dimensional modeling apparatus disclosed herein includes a modeling tank formed in a box shape having an opening portion in at least a portion, and housing a powder material; an ejection device disposed in a manner facing the opening portion of the modeling tank, and ejecting a solidification liquid that solidifies the powder material toward the opening portion; and a control device that controls the ejection device to eject the solidification liquid.

[0013] The ejection device has a first nozzle row, a second nozzle row, and a third nozzle row. The first nozzle row is composed of a plurality of nozzles arranged and disposed in a prescribed first direction, and each ejects the solidification liquid. The second nozzle row is composed of other plurality of nozzles arranged and disposed in the first direction, and each ejects the solidification liquid. The third nozzle row is composed of still other plurality of nozzles arranged and disposed in the first direction, and each ejects the solidification liquid. The first nozzle row and the second nozzle row are disposed closer than a prescribed first distance in a second direction orthogonal to the first direction. The first nozzle row and the third nozzle row are disposed apart by the first distance or more in the second direction.

[0014] The control device is set to, in at least a portion of the time of ejecting the solidification liquid from the ejection device, eject the solidification liquid from the plurality of nozzles of the first nozzle row and the still other plurality of nozzles of the third nozzle row, and not to eject the solidification liquid from the other plurality of nozzles of the second nozzle row.

[0015] According to the above-described second three-dimensional modeling apparatus, in at least a portion of the time of ejecting the solidification liquid from the ejection device, the solidification liquid is not ejected from the nozzles of the second nozzle row that are at a distance of less than the first distance from the first nozzle row. Therefore, in the above-described at least a portion of the time, the solidification liquid is not simultaneously ejected from the nozzles of the first nozzle row and the nozzles of the second nozzle row that are closer to each other than the first distance. Thus, for the same reason as the first three-dimensional modeling apparatus, the attachment of the powder material to the nozzles due to the ejection of the solidification liquid can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1is a cross-sectional view schematically showing a three-dimensional modeling apparatus to which the first embodiment is applied.

[0017] Figure 2 is a plan view schematically showing a three-dimensional modeling apparatus.

[0018] Figure 3 is a plan view schematically showing a lower surface of a carriage.

[0019] Figure 4 is a table showing an attachment condition of a powder material to a nozzle based on a discharge condition of a solidified liquid.

[0020] Figure 5 is a plan view schematically showing a lower surface of a carriage of a three-dimensional modeling apparatus to which the second embodiment is applied.

[0021] Figure 6 is a block diagram of a three-dimensional modeling apparatus to which the second embodiment is applied.

[0022] Explanation of Reference Numerals

[0023] 10 three-dimensional modeling apparatus

[0024] 40 supply tank

[0025] 50 modeling tank

[0026] 70 head unit (discharge apparatus)

[0027] 71 nozzle

[0028] 72 nozzle row

[0029] 100 control apparatus

[0030] 200 powder material

[0031] 210 powder layer

[0032] D0 nozzle row-to-nozzle row distance (first embodiment)

[0033] D1 first distance

[0034] D2 second distance (distance between first nozzle row and second nozzle row)

[0035] D3 third distance (distance between first nozzle row and third nozzle row) DETAILED DESCRIPTION

[0036] Hereinafter, a three-dimensional modeling apparatus to which an embodiment of the present application is applied will be described with reference to the accompanying drawings. Further, the embodiment described here is of course not intended to particularly limit the present application. In addition, components having the same function are denoted by the same reference numerals, and repeated description is appropriately omitted or simplified.

[0037] Figure 1 is a cross-sectional view schematically showing a three-dimensional modeling apparatus 10 according to an embodiment. Figure 2 is a plan view of the three-dimensional modeling apparatus 10. Figure 1 is Figure 2 the I-I section of Fig. 1. The reference sign F in the figure indicates the front direction, and the reference sign Rr indicates the rear direction. Here, the left, right, upper, and lower directions when the three-dimensional modeling apparatus 10 is viewed from the direction of the reference sign F are the left, right, upper, and lower directions of the three-dimensional modeling apparatus 10, respectively. The reference signs L, R, U, and D in the figure indicate the left, right, upper, and lower directions, respectively. The reference signs X, Y, and Z indicate the front-rear direction, the left-right direction, and the up-down direction, respectively. The left-right direction Y is the main scanning direction of the three-dimensional modeling apparatus 10. The front-rear direction X is the sub-scanning direction of the three-dimensional modeling apparatus 10. In addition, the up-down direction Z is the layering direction of the three-dimensional modeling. The main scanning direction Y, the sub-scanning direction X, and the up-down direction Z are orthogonal to each other. However, these directions are merely directions determined for the sake of convenience of explanation and do not impose any limitation on the arrangement of the three-dimensional modeling apparatus 10.

[0038] As shown in Figure 1 , the three-dimensional modeling apparatus 10 includes a main body 11, a modeling tank unit 12, a roller unit 30, a carriage 85, a head unit 70, a sub-scanning direction moving mechanism 20, a main scanning direction moving mechanism 80, and a control device 100. The modeling tank unit 12 mounts a supply tank 40, a modeling tank 50, and a powder recovery tank 60. The three-dimensional modeling apparatus 10 forms a powder layer 210 by flattening the powder material 200 supplied from the supply tank 40 on the modeling tank 50 and solidifies the powder layer 210 by ejecting a solidification liquid to a desired position of the powder layer 210, thereby forming a solidification layer 220. Then, the three-dimensional modeling apparatus 10 models a molded object 230 by layering the solidification layer 220 on the upper side.

[0039] As shown in Figure 2 , the main body 11 is an outer body of the three-dimensional modeling apparatus 10 having a long shape in the sub-scanning direction X. The main body 11 is formed in a box shape that is open toward the upper side. The main body 11 houses the sub-scanning direction moving mechanism 20, the modeling tank unit 12, and the control device 100. In addition, as shown in Figure 1 , the main body 11 supports the roller unit 30 and the main scanning direction moving mechanism 80.

[0040] As shown in Figure 1 , the modeling tank unit 12 is housed in the main body 11. The upper surface 12a of the modeling tank unit 12 is flat, and the modeling tank 50, the supply tank 40, and the powder recovery tank 60 are independently arranged in a manner of being recessed from the upper surface 12a.

[0041] The supply tank 40 is disposed on the rear side of the modeling tank unit 12. The powder material 200 before being supplied to the modeling tank 50 is stored in the supply tank 40. AsFigure 1 As shown, the supply tank 40 includes a cylindrical portion 41 that extends vertically. (As indicated...) Figure 2 As shown, the cylindrical portion 41 has an opening 41a that opens upwards. The shape of the opening 41a is rectangular when viewed from above. However, the planar shape of the opening 41a is not limited to a rectangle.

[0042] The composition and form of the powder material 200 are not particularly limited, and powders composed of various materials such as resin materials, metallic materials, and inorganic materials can be used. Examples of powder materials 200 include ceramic materials such as alumina, silicon dioxide, titanium dioxide, and zirconium oxide; iron, aluminum, titanium, and their alloys (typically stainless steel, titanium alloys, and aluminum alloys); hemihydrate gypsum (α-type calcined gypsum, β-type calcined gypsum); apatite; salt; and plastics. They can be composed of any one material or a combination of two or more. When the powder material 200 is a mixed powder, the particle size of each component powder can also be different. For example, the powder used as a binder can be finer than the powder used as aggregate.

[0043] Inside the cylindrical portion 41, a supply platform 42, which has the same shape as the cylindrical portion 41 when viewed from above, is housed. Figure 1 As shown, the supply table 42 has a flat plate shape. The supply table 42 is inserted horizontally into the cylindrical portion 41. The supply table 42 is configured to move freely up and down within the cylindrical portion 41. A supply table lifting mechanism 43 is provided at the lower part of the supply table 42. The supply table lifting mechanism 43 is configured to support the supply table 42 and raise and lower it. Here, the supply table lifting mechanism 43 supports the supply table 42 from below. The supply table lifting mechanism 43 includes a support portion 43a, a drive motor 43b, and a ball screw (not shown). The support portion 43a is connected to the lower surface of the supply table 42. The support portion 43a is connected to the drive motor 43b via the ball screw. By driving the drive motor 43b, the support portion 43a moves in the up and down direction. The supply table 42 is supported by the support portion 43a and moves together with the support portion 43a in the up and down direction. The drive motor 43b is electrically connected to the control device 100 and is controlled by the control device 100. The drive motor 43b is, for example, a servo motor, configured to control the height of the supply table 42.

[0044] like Figure 2 As shown, the shaping groove 50 is disposed in front of the supply groove 40. The supply groove 40 and the shaping groove 50 are arranged in the sub-scanning direction X. The shaping groove 50 is disposed in the main scanning direction Y at a position aligned with the supply groove 40. The shaping groove 50 is formed in a box shape and has an opening in at least a portion. In detail, the shaping groove 50 has a cylindrical portion 51 formed as a cylinder extending in the vertical direction (see reference). Figure 1), the cylindrical portion 51 has an opening portion 51a that is open upward. In the modeling groove 50, the powder material 200 is housed. The modeling groove 50 is a groove in which the powder material 200 is molded by the modeled article 230 inside thereof. As shown in Figure 2 The shape of the opening portion 51a is rectangular in plan view. However, the planar shape of the opening portion 51a is not limited to a rectangle. The length of the main scanning direction Y of the opening portion 51a is the same as the length of the main scanning direction Y of the opening portion 41a of the supply groove 40 in plan view. However, the length of the main scanning direction Y of the opening portion 51a of the modeling groove 50 can be shorter than the length of the main scanning direction Y of the opening portion 41a of the supply groove 40.

[0045] As shown in Figure 1 In the inside of the cylindrical portion 51, a modeling table 52 having the same shape as the cylindrical portion 51 in plan view is housed. In the modeling of the modeled article 230, the powder material 200 is supplied to the modeling table 52, and the modeling is performed on the modeling table 52. As shown in Figure 1 The modeling table 52 has a shape of a flat plate. The modeling table 52 is inserted into the cylindrical portion 51 substantially horizontally. The modeling table 52 is configured to be freely raised and lowered in the vertical direction in the inside of the cylindrical portion 51. In the lower portion of the modeling table 52, a modeling table raising and lowering mechanism 53 is provided. The modeling table raising and lowering mechanism 53 is configured to support the modeling table 52 and raise and lower it. Here, the modeling table raising and lowering mechanism 53 supports the modeling table 52 from below. The modeling table raising and lowering mechanism 53 has a support portion 53a, a drive motor 53b, and a ball screw that is not shown. The support portion 53a is connected to the lower surface of the modeling table 52. The support portion 53a is connected to the drive motor 53b via the ball screw. By driving the drive motor 53b, the support portion 53a moves in the vertical direction. The modeling table 52 is supported by the support portion 53a and moves in the vertical direction together with the support portion 53a. The drive motor 53b is electrically connected to the control device 100 and is controlled by the control device 100. The drive motor 53b is, for example, a servo motor and is configured to be able to control the height of the modeling table 52.

[0046] The powder recovery groove 60 is a groove that recovers the powder material 200 that cannot be housed in the modeling groove 50 when the powder material 200 is spread over the modeling groove 50. The powder recovery groove 60 is disposed in front of the modeling groove 50. As shown in Figure 2As shown, the powder recovery tank 60, molding tank 50, and supply tank 40 are arranged in the sub-scanning direction X. The powder recovery tank 60 is positioned aligned with the molding tank 50 in the main scanning direction Y. The powder recovery tank 60 has an opening 60a that opens upwards. The shape of the opening 60a is rectangular when viewed from above. However, the planar shape of the opening 60a is not limited to a rectangle. When viewed from above, the length of the opening 60a in the main scanning direction Y is the same as the length of the opening 41a of the supply tank 40 and the opening 51a of the molding tank 50 in the main scanning direction Y. However, the length of the opening 60a of the powder recovery tank 60 in the main scanning direction Y may also be longer than the length of the opening 51a of the molding tank 50 in the main scanning direction Y.

[0047] The sub-scanning direction moving mechanism 20 is configured to move the molding groove unit 12 relative to the head unit 70 and the roller unit 30 in the sub-scanning direction X. The sub-scanning direction moving mechanism 20 includes a pair of guide rails 21 and a feed motor 22.

[0048] like Figure 1 As shown, guide rail 21 guides the shape groove unit 12 to move in the sub-scanning direction X. Guide rail 21 is disposed within the main body 11. Guide rail 21 extends in the sub-scanning direction X. Shape groove unit 12 is slidably engaged with guide rail 21. However, the position and number of guide rails 21 are not particularly limited. Feed motor 22 is connected to shape groove unit 12, for example, via ball screw. Feed motor 22 is electrically connected to control device 100. Driven by the rotation of feed motor 22, shape groove unit 12 moves along sub-scanning direction X on guide rail 21.

[0049] The sub-scanning direction moving mechanism 20 and the roller unit 30 constitute a layer forming apparatus that flattens the powder material 200 supplied by the supply trough 40 onto the molding trough 50. The roller unit 30 includes a laying roller 31 and roller support members 32 supporting the laying roller 31. The laying roller 31 is positioned above the main body 11. The laying roller 31 is positioned in front of the head unit 70. The laying roller 31 has an elongated cylindrical shape. The laying roller 31 is arranged with its cylindrical axis along the main scanning direction Y. The length of the laying roller 31 in the main scanning direction Y is longer than the molding trough 50. The lower end of the laying roller 31 is positioned slightly above the molding trough unit 12, forming a predetermined gap between it and the upper surface 12a of the molding trough unit 12. The laying roller 31 is rotatable, supported by a pair of roller support members 32 provided on the upper surface 11a of the main body 11. The laying roller 31 may also be configured to rotate via a connected electric motor, for example.

[0050] When the molding groove unit 12 is moved rearward by the sub-scanning direction moving mechanism 20, the laying roller 31 is moved forward relative to the supply groove 40, the molding groove 50, and the powder recovery groove 60. Thus, at this time, the laying roller 31 is moved from the supply groove 40, over the molding groove 50, and onto the powder recovery groove 60. At this time, the laying roller 31 is moved from the supply groove 40, over the molding groove 50, and onto the powder recovery groove 60 while maintaining a prescribed height higher than the supply groove 40, the molding groove 50, and the powder recovery groove 60.

[0051] As shown in FIG. 6, the head unit 70 is provided on the lower surface of the carriage 85. The head unit 70 is provided so as to face the opening portion 51a of the molding groove 50. The head unit 70 is configured to eject a solidification liquid that solidifies the powder material 200 toward the opening portion 51a. The ejection mechanism of the solidification liquid in the head unit 70 is not particularly limited, and for example, an inkjet method or the like can be appropriately used. The head unit 70 is electrically connected to the control device 100 and is controlled by the control device 100. Figure 2

[0052] Figure 3 FIG. 7 is a plan view schematically showing the lower surface of the carriage 85. As shown in FIG. 7, the head unit 70 has a plurality of nozzle rows 72 each of which is composed of a plurality of nozzles 71. The plurality of nozzles 71 that compose each nozzle row 72 are arranged in the sub-scanning direction X. Each nozzle 71 is configured to eject a solidification liquid. In the present embodiment, only a small number of nozzles 71 are illustrated, but in the present embodiment, the plurality of nozzles 71 are arranged at a density of 1200 dpi in the sub-scanning direction X in each of the plurality of nozzle rows 72. That is, the nozzles 71 are arranged at a pitch of 1200 nozzles 71 per 1 inch. However, the plurality of nozzles 71 can be arranged at a density smaller than 1200 dpi, for example, at a density of 360 dpi or 720 dpi, in the sub-scanning direction X in each nozzle row 72. Figure 3 Figure 3 As shown in FIG. 7, the head unit 70 has a plurality of nozzle rows 72 each of which is composed of a plurality of nozzles 71. The plurality of nozzles 71 that compose each nozzle row 72 are arranged in the sub-scanning direction X. Each nozzle 71 is configured to eject a solidification liquid. In the present embodiment, only a small number of nozzles 71 are illustrated, but in the present embodiment, the plurality of nozzles 71 are arranged at a density of 1200 dpi in the sub-scanning direction X in each of the plurality of nozzle rows 72. That is, the nozzles 71 are arranged at a pitch of 1200 nozzles 71 per 1 inch. However, the plurality of nozzles 71 can be arranged at a density smaller than 1200 dpi, for example, at a density of 360 dpi or 720 dpi, in the sub-scanning direction X in each nozzle row 72.

[0053] As shown in FIG. 7, the head unit 70 has a plurality of nozzle rows 72 each of which is composed of a plurality of nozzles 71. The plurality of nozzles 71 that compose each nozzle row 72 are arranged in the sub-scanning direction X. Each nozzle 71 is configured to eject a solidification liquid. In the present embodiment, only a small number of nozzles 71 are illustrated, but in the present embodiment, the plurality of nozzles 71 are arranged at a density of 1200 dpi in the sub-scanning direction X in each of the plurality of nozzle rows 72. That is, the nozzles 71 are arranged at a pitch of 1200 nozzles 71 per 1 inch. However, the plurality of nozzles 71 can be arranged at a density smaller than 1200 dpi, for example, at a density of 360 dpi or 720 dpi, in the sub-scanning direction X in each nozzle row 72. Figure 3 Figure 3 As shown in FIG. 7, the head unit 70 has a plurality of nozzle rows 72 each of which is composed of a plurality of nozzles 71. The plurality of nozzles 71 that compose each nozzle row 72 are arranged in the sub-scanning direction X. Each nozzle 71 is configured to eject a solidification liquid. In the present embodiment, only a small number of nozzles 71 are illustrated, but in the present embodiment, the plurality of nozzles 71 are arranged at a density of 1200 dpi in the sub-scanning direction X in each of the plurality of nozzle rows 72. That is, the nozzles 71 are arranged at a pitch of 1200 nozzles 71 per 1 inch. However, the plurality of nozzles 71 can be arranged at a density smaller than 1200 dpi, for example, at a density of 360 dpi or 720 dpi, in the sub-scanning direction X in each nozzle row 72.

[0054] ​​​The curing liquid is not particularly limited to any material capable of fixing the powder material 200 together. Depending on the type of powder material 200, the curing liquid is a liquid (including an adhesive) capable of binding the particles constituting the powder material 200 together. Examples of curing liquids include liquids containing water, wax, adhesives, etc. Furthermore, if the powder material 200 has a water-soluble resin as a byproduct, a liquid capable of dissolving the water-soluble resin, such as water, can be used as the curing liquid. This water-soluble resin is not particularly limited; examples include starch, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), water-soluble acrylic resin, water-soluble polyurethane resin, water-soluble polyamide, etc.

[0055] The main scanning direction moving mechanism 80 moves the carriage 85 along the main scanning direction Y. For example... Figure 2 As shown, the main scanning direction moving mechanism 80 includes a guide rail 81. The guide rail 81 extends along the main scanning direction Y. A carriage 85 is slidably engaged on the guide rail 81. A carriage motor 82 is connected to the carriage 85, for example, via an annular belt and pulleys (see reference). Figure 1 The carriage 85 moves along the guide rail 81 in the main scanning direction Y by driving the carriage motor 82. The carriage motor 82 is electrically connected to the control device 100 and is controlled by the control device 100. As the carriage 85 moves along the main scanning direction Y, the head unit 70 also moves along the main scanning direction Y.

[0056] like Figure 1 As shown, an operation panel 150 is provided on the front surface of the main body 11. The operation panel 150 includes a display section for showing the device status, input keys for user operation, etc. The operation panel 150 is connected to a control device 100 that controls various actions of the 3D modeling device 10. The control device 100 is electrically connected to the feed motor 22, the drive motor 43b of the supply table lifting mechanism 43, the drive motor 53b of the modeling table lifting mechanism 53, the head unit 70, and the carriage motor 82, and controls their actions.

[0057] The configuration of the control device 100 is not particularly limited. The control device 100 is, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited, and, for example, has an interface (I / F) that receives modeling data and the like from an external device such as a host computer, a central processing unit (CPU) that executes a command of a control program, a ROM (read only memory) in which a program executed by the CPU is stored, a RAM (random access memory) that is used as a work area for expanding the program, and a storage device such as a memory that stores the above-described program and various data. In addition, the control device 100 does not necessarily have to be provided inside the three-dimensional modeling device 10, and, for example, can be a computer or the like that is provided outside the three-dimensional modeling device 10 and communicably connected to the three-dimensional modeling device 10 through a wire or wirelessly.

[0058] The three-dimensional modeling device 10 models the modeled object 230, for example, by the following process. According to one preferred process, when the formation of one solidified layer 220 is finished, the three-dimensional modeling device 10 raises the supply table 42 and lowers the modeling table 52. At the time point when the formation of one solidified layer 220 is finished, the upper surface of the powder material 200 on the supply table 42 is located at the same height as the lower end portion of the laying roller 31. At this time, the upper surface of the solidified layer 220 formed at the uppermost position in the modeling tank 50 is also located at the same height as the lower end portion of the laying roller 31.

[0059] When the supply table 42 is raised from this state, a part of the powder material 200 on the upper side thereof overflows from the supply tank 40. This powder material 200 that overflows from the supply tank 40 becomes the powder material 200 supplied from the supply tank 40. The modeling table 52 is lowered by a prescribed distance from the above-described state. This prescribed distance is the same as the thickness of the solidified layer 220 to be formed next. The modeling table 52 is lowered by the thickness of one layer of the solidified layer 220 at the time of supply of the powder material 200. This distance is, for example, 0.1 mm.

[0060] Then, the three-dimensional modeling device 10 moves the laying roller 31 forward with respect to the modeling tank unit 12. At this time, in fact, the laying roller 31 is stationary, and the modeling tank unit 12 is moved toward the rear. By this relative movement, the laying roller 31 moves from the rear of the supply tank 40, via the upper sides of the supply tank 40 and the modeling tank 50, to the upper side of the powder recovery tank 60. By the laying roller 31, a new powder material 200 is laid on the modeling tank table 52. Thus, a new powder layer 210 is formed on the modeling tank table 52. The powder material 200 that is not laid on the modeling tank table 52 falls into the powder recovery tank 60.

[0061] After the new powder layer 210 is formed on the solidified layer 220 as described above, the three-dimensional modeling apparatus 10 controls the feed motor 22, the head unit 70, and the carriage motor 82 to eject the solidification liquid toward a desired position on the powder layer 210. Thereby, a new solidified layer 220 is formed on the powder layer 210. By repeating this process, the molded article 230 is completed. Note that this process is merely a preferred example, and the process of forming the molded article 230 is not limited thereto.

[0062] When the solidification liquid is ejected, the plurality of ejection heads 73 are separated from the powder layer 210 on the modeling tank 50 by a predetermined distance in the vertical direction. Hereinafter, this distance is also referred to as a head gap. The head gap is a distance in the vertical direction between a lower surface (also referred to as a nozzle face) of the ejection head 73 in which the nozzle row 72 is formed and an upper surface of the powder layer 210. In the vertical direction, the position of the upper surface of the powder layer 210 is equal to the position of the lower end of the spreading roller 31. In the present embodiment, the head gap is 2 mm. However, the head gap can be larger than 2 mm or smaller than 2 mm.

[0063] (Problem of the conventional three-dimensional modeling apparatus)

[0064] In the conventional powder solidification-type three-dimensional modeling apparatus, a problem is known in which the powder material in the modeling tank is scattered due to the ejection of the solidification liquid. When the scattered powder material adheres to the nozzle of the ejection head, the adhered powder material can be solidified by the solidification liquid. If the powder material adhering to the nozzle is solidified, adverse situations such as clogging of the nozzle, bending of the flight direction of the solidification liquid, and the like can occur.

[0065] According to the present inventors' insight, such scattering of the powder material is caused by the generation of an upward airflow by a large number of liquid droplets of the solidification liquid ejected from the head unit. Since a large number of liquid droplets of the solidification liquid are ejected at a high speed, an airflow is generated in the space between the nozzle and the powder layer, respectively. According to the present inventors' insight, particularly in the main scanning direction Y, if two liquid droplets of the solidification liquid are ejected at a close distance, the airflows generated by the two liquid droplets interfere with each other to generate an upward airflow. The powder material is entrained by the upward airflow.

[0066] Based on the above insight, the present inventors have conceived the possibility that, in the main scanning direction Y and the sub-scanning direction X, particularly in the main scanning direction Y, if two liquid droplets of the solidification liquid are ejected at a distance farther than a certain degree, the airflows generated by the two liquid droplets do not interfere with each other, and the generation of the upward airflow is suppressed.

[0067] Therefore, in the three-dimensional modeling apparatus 10 according to the present embodiment, the plurality of nozzles 71 are arranged at a density of 1200 dpi in the sub-scanning direction X in each nozzle row 72, and the plurality of nozzle rows 72 are arranged at a distance of 11 mm from each other in the main scanning direction Y orthogonal to the sub-scanning direction X. Hereinafter, the degree of adhesion of the powder material 200 to the nozzles 71 in the three-dimensional modeling apparatus 10 according to the present embodiment is shown in comparison with other three-dimensional modeling apparatuses.

[0068] (Conditions for ejection of curing liquid and results of confirmation of adhesion of powder material)

[0069] Figure 4 is a table showing the adhesion of the powder material to the nozzles based on the conditions for ejection of the curing liquid. Figure 4 represents the conditions for ejection of the curing liquid and the adhesion of the powder material 200 at that time in the three-dimensional modeling apparatus 10 according to the present embodiment. In addition, Figure 4 represents the conditions for ejection of a plurality of curing liquids in other three-dimensional modeling apparatuses and the adhesion of the powder material when the curing liquid is ejected under each of the conditions for ejection.

[0070] As shown in Figure 4 , in the three-dimensional modeling apparatus 10 according to the present embodiment, the distance between the plurality of nozzle rows 72 is 11 mm. The head gap is 2 mm. The scanning speed of the carriage 85 is 150 mm / s. The density of the nozzles 71 in the sub-scanning direction X is 1200 dpi. The ejection density of the curing liquid in the main scanning direction Y is 1200 dpi. The size (volume) of the droplets of the curing liquid is 8 pl (picoliter). The powder material 200 is a mixed powder of ceramic powder 85% + binder powder 15% having an average particle diameter of 50 μm. The curing liquid is water to which 5% of a surfactant is added. The thickness of one layer of the cured layer 220 is 0.1 mm. As shown in Figure 4 , under the ejection conditions, even after 100 layers of the cured layer 220 are formed, no adhesion of the powder material 200 to the nozzles 71 was found.

[0071] On the other hand, in other three-dimensional modeling apparatuses, as shown in Figure 4As shown, the distance between the multiple nozzle rows is 2.3 mm. This distance is smaller than that of the 3D modeling apparatus 10 according to this embodiment. The head gap is 2 mm, the same as in the 3D modeling apparatus 10 according to this embodiment. The carriage scanning speed is 150 mm / s, the same as in the 3D modeling apparatus 10 according to this embodiment. The nozzle density in the sub-scanning direction is 180 dpi. The curing liquid ejection density in the main scanning direction is 720 dpi. The powder material and curing liquid are the same as those used in the 3D modeling apparatus 10 according to this embodiment. The thickness of the cured layer and the ejection range (area) of the curing liquid are the same as in the 3D modeling apparatus 10 according to this embodiment. In other 3D modeling apparatuses, tests were conducted on curing liquid volumes of 11 pl, 38 pl, and 60 pl.

[0072] like Figure 4 As shown, in other three-dimensional modeling apparatuses, given any size of the curing liquid, after forming three cured layers, it has been confirmed that powder material adheres to the nozzle. From this result, it can be seen that the three-dimensional modeling apparatus 10 according to this embodiment can suppress the adhesion of powder material to the nozzle compared to conventional three-dimensional modeling apparatuses.

[0073] Regarding the spraying conditions of the curing liquid, it can be assumed that the same conditions between the 3D modeling apparatus 10 and other 3D modeling apparatuses are irrelevant to the differences mentioned above. Among nozzles with different conditions, regarding the nozzle density in the sub-scanning direction, it can be assumed that a lower density can suppress the generation of rising airflow and reduce powder material adhesion. Furthermore, regarding the spraying density of the curing liquid in the main scanning direction, it can be assumed that a lower density results in fewer scans of the carriage, thus reducing powder material adhesion. Figure 4 In the experimental cases shown, other 3D modeling devices with lower nozzle density in the sub-scanning direction and lower curing liquid ejection density in the main scanning direction exhibit more powder material adhesion compared to the 3D modeling device 10 described in this embodiment. Therefore, regarding the suppression of powder material adhesion, it can be considered that the contribution of nozzle density in the sub-scanning direction and curing liquid ejection density in the main scanning direction is small.

[0074] Furthermore, the size of the curing liquid does not affect the test results of other 3D modeling devices. Therefore, the size of the curing liquid is also considered to be a factor that contributes little to inhibiting the adhesion of powder materials.

[0075] Based on these studies, it can be concluded that increasing the distance between nozzle rows is effective in suppressing the adhesion of powder material to the nozzle. Figure 4The results of the test show that if the distance between the nozzle rows is 11 mm or more, the adhesion of the powder material to the nozzles can be almost completely eliminated. The density of the nozzles in the sub-scanning direction can be at least 1200 dpi or less, and as long as it is 1200 dpi or less, the adhesion of the powder material to the nozzles is almost not affected.

[0076] Furthermore, the inventors of the present application have considered that, within the range in which the adhesion of the powder material to the nozzles can be inhibited, the distance between the nozzle rows is made close, the size of the head unit in the main scanning direction is made more compact, and the prescribed ejection density in the main scanning direction can be achieved with less scanning time.

[0077] According to the inventors of the present application, in the main scanning direction Y, if the plurality of nozzle rows are arranged with a separation of 5 mm or more from each other, the flying of the powder material can be inhibited, and the adhesion of the powder material to the nozzles can be inhibited.

[0078] According to the results of the ejection simulation of the curing liquid, if the plurality of nozzle rows are arranged with a separation of 5 mm or more from each other, the generation of the upward airflow is reduced. Therefore, it can be considered that if the plurality of nozzle rows are arranged with a separation of 5 mm or more from each other, the flying of the powder material can be inhibited, and the adhesion of the powder material to the nozzles can be inhibited. However, the effect based on this structure does not necessarily mean that the powder material hardly adheres to the nozzles, but the amount of the adhesion of the powder material can be reduced compared with the conventional three-dimensional modeling apparatus, for example, the three-dimensional modeling apparatus in which the distance between the nozzle rows is 2.3 mm.

[0079] (Second Embodiment)

[0080] In the second embodiment, the plurality of nozzle rows are arranged with a separation shorter than the prescribed distance for inhibiting the rolling of the powder material, but the nozzle rows used at the same time are limited. Thus, the distance between the nozzle rows used at the same time is kept longer than the prescribed distance for inhibiting the rolling of the powder material. In the following description of the second embodiment, for the components that function commonly with the first embodiment, the reference numerals common with the first embodiment are used. In addition, the repeated description is appropriately omitted or simplified.

[0081] Figure 5 is a plan view schematically showing the lower surface of the carriage 85 of the three-dimensional modeling apparatus 10 according to the second embodiment. As shown in FIG. 8, the carriage 85 includes a plurality of nozzle rows 81, 82, 83, 84, and 85. The nozzle rows 81, 82, 83, 84, and 85 are arranged in the main scanning direction Y. The nozzle rows 81, 82, 83, 84, and 85 are arranged with a separation of 5 mm or more from each other in the main scanning direction Y. Figure 5As shown, in the present embodiment, the plurality of discharge heads 73 each has two nozzle rows 72. Here, the head unit 70 has four discharge heads 73 arranged in the main scanning direction Y. Hereinafter, in order to distinguish the plurality of nozzle rows 72 from each other, the plurality of nozzle rows 72 will be referred to as the first nozzle row 72A to the eighth nozzle row 72H in order from the left to the right. In addition, in order to distinguish the plurality of discharge heads 73 from each other, the plurality of discharge heads 73 will be referred to as the first head 73A, the second head 73C, the third head 73E, and the fourth head 73G in order from the left to the right. However, the number of discharge heads 73 is not particularly limited, and the number of nozzle rows 72 formed in the discharge heads 73 is also not particularly limited.

[0082] As shown, the first nozzle row 72A and the second nozzle row 72B are formed in the first head 73A. The third nozzle row 72C and the fourth nozzle row 72D are formed in the second head 73C. The fifth nozzle row 72E and the sixth nozzle row 72F are formed in the third head 73E. The seventh nozzle row 72G and the eighth nozzle row 72H are formed in the fourth head 73G. Figure 5

[0083] As shown, the first nozzle row 72A and the second nozzle row 72B are arranged closer than a prescribed first distance Dl in the main scanning direction Y. In detail, the first nozzle row 72A and the second nozzle row 72B are arranged apart by a second distance D2 smaller than the first distance Dl in the main scanning direction Y. The first distance Dl is a distance between nozzle rows 72 that can suppress curling of the powder material 200. The first distance Dl can be set to 5 mm, for example. Alternatively, the first distance Dl can be set to a distance larger than 5 mm and smaller than 11 mm. The first distance Dl can also be set to 11 mm. Figure 5

[0084] On the other hand, the first nozzle row 72A and the third nozzle row 72C are arranged apart by a distance of the first distance Dl or more in the main scanning direction Y. In detail, the distance between the first nozzle row 72A and the third nozzle row 72C is a third distance D3 larger than the first distance Dl. However, the third distance D3 can be equal to the first distance Dl. Hereinafter, likewise, the third nozzle row 72C and the fourth nozzle row 72D are arranged apart by the second distance D2 in the main scanning direction Y. The third nozzle row 72C and the fifth nozzle row 72E are arranged apart by the third distance D3 in the main scanning direction Y. The fifth nozzle row 72E and the sixth nozzle row 72F are arranged apart by the second distance D2 in the main scanning direction Y. The fifth nozzle row 72E and the seventh nozzle row 72G are arranged apart by the third distance D3 in the main scanning direction Y. The seventh nozzle row 72G and the eighth nozzle row 72H are arranged apart by the second distance D2 in the main scanning direction Y.

[0085] ​​Therefore, although not illustrated, the distance of the second nozzle row 72B from the fourth nozzle row 72D, the distance of the fourth nozzle row 72D from the sixth nozzle row 72F, and the distance of the sixth nozzle row 72F from the eighth nozzle row 72H in the main scanning direction Y are all the third distance D3.

[0086] The control device 100 according to the present embodiment is configured to cause the fixing liquid to be ejected from the nozzles 71 of the first nozzle row 72A, the third nozzle row 72C, the fifth nozzle row 72E, and the seventh nozzle row 72G, and not to be ejected from the nozzles 71 of the second nozzle row 72B, the fourth nozzle row 72D, the sixth nozzle row 72F, and the eighth nozzle row 72H, at least a part of the time during which the fixing liquid is ejected from the head unit 70. In detail, the control device 100 according to the present embodiment causes the fixing liquid to be ejected from the nozzles 71 of the first nozzle row 72A, the third nozzle row 72C, the fifth nozzle row 72E, and the seventh nozzle row 72G, and not to be ejected from the nozzles 71 of the second nozzle row 72B, the fourth nozzle row 72D, the sixth nozzle row 72F, and the eighth nozzle row 72H, at a part of the time during which the fixing liquid is ejected from the head unit 70 (hereinafter, referred to as a first time period). In the first time period, the fixing liquid is ejected from the nozzles 71 of the first nozzle row 72A, the third nozzle row 72C, the fifth nozzle row 72E, and the seventh nozzle row 72G, and not from the nozzles 71 of the second nozzle row 72B, the fourth nozzle row 72D, the sixth nozzle row 72F, and the eighth nozzle row 72H. Figure 5 In the first time period, the nozzles 71 from which the fixing liquid is ejected are indicated by double circles.

[0087] In addition, the control device 100 according to the present embodiment is configured to cause the fixing liquid to be ejected from the nozzles 71 of the second nozzle row 72B, the fourth nozzle row 72D, the sixth nozzle row 72F, and the eighth nozzle row 72H, and not to be ejected from the nozzles 71 of the first nozzle row 72A, the third nozzle row 72C, the fifth nozzle row 72E, and the seventh nozzle row 72G, at another part of the time during which the fixing liquid is ejected from the head unit 70 (hereinafter, referred to as a second time period). In the second time period, the fixing liquid is ejected from the nozzles 71 of the second nozzle row 72B, the fourth nozzle row 72D, the sixth nozzle row 72F, and the eighth nozzle row 72H, and not from the nozzles 71 of the first nozzle row 72A, the third nozzle row 72C, the fifth nozzle row 72E, and the seventh nozzle row 72G. Figure 5 In the second time period, the nozzles 71 from which the fixing liquid is ejected are indicated by triangles.

[0088] However, the control device 100 can also be configured to cause the curing liquid to be ejected from the nozzles 71 of the first nozzle row 72A, the third nozzle row 72C, the fifth nozzle row 72E, and the seventh nozzle row 72G, and not to be ejected from the nozzles 71 of the second nozzle row 72B, the fourth nozzle row 72D, the sixth nozzle row 72F, and the eighth nozzle row 72H, for the entire time during which the curing liquid is ejected from the head unit 70. Alternatively, the control device 100 can also be configured to cause the curing liquid to be ejected from the nozzles 71 of the second nozzle row 72B, the fourth nozzle row 72D, the sixth nozzle row 72F, and the eighth nozzle row 72H, and not to be ejected from the nozzles 71 of the first nozzle row 72A, the third nozzle row 72C, the fifth nozzle row 72E, and the seventh nozzle row 72G, for the entire time during which the curing liquid is ejected from the head unit 70. In other words, the three-dimensional modeling device 10 can also be configured to use only the odd-numbered nozzle rows 72A, 72C, 72E, and 72G, or only the even-numbered nozzle rows 72B, 72D, 72F, and 72H.

[0089] Figure 6 is a block diagram of the three-dimensional modeling device 10 to which the present embodiment is related. As shown in Figure 6 the present embodiment, the control device 100 is provided with a first counter 110, a second counter 120, a nozzle row selection section 130, and a timing correction section 140. The first counter 110 is configured to measure the cumulative time during which the curing liquid is ejected from the odd-numbered nozzle rows 72A, 72C, 72E, and 72G (in other words, the cumulative time of the first time period). When the time accumulated by the first counter 110 exceeds a prescribed time, the even-numbered nozzle rows 72B, 72D, 72F, and 72H are used from the formation of the next solidification layer 220. The second counter 120 is configured to measure the cumulative time during which the curing liquid is ejected from the even-numbered nozzle rows 72B, 72D, 72F, and 72H (in other words, the cumulative time of the second time period). When the time accumulated by the second counter 120 exceeds a prescribed time, the odd-numbered nozzle rows 72A, 72C, 72E, and 72G are used again from the formation of the next solidification layer 220.

[0090] The nozzle row selection section 130 selects the nozzle row 72 to be used in accordance with the measurements of the first counter 110 and the second counter 120. The timing correction section 140 corrects the timing at which the curing liquid is ejected in accordance with the selected nozzle row 72.

[0091] However, the control is only one example, and the method of the control related to the selection of the nozzle rows 72 is not limited. For example, the first time period and the second time period can also be switched per a predetermined number of ejections of the curing liquid. In this case, the first counter 110 is configured to count the number of times of ejections of the curing liquid from the odd-numbered nozzle rows 72A, 72C, 72E, and 72G. In addition, the second counter 120 is configured to count the number of times of ejections of the curing liquid from the even-numbered nozzle rows 72B, 72D, 72F, and 72H. Alternatively, the first time period and the second time period can also be switched every time a predetermined number of the cured layers 220 are formed. The first time period and the second time period can also be switched per job. In these cases as well, the first counter 110 and the second counter 120 count the number of the cured layers 220 or the number of jobs.

[0092] Further, although not described or illustrated, the control device 100 can also have other control sections that perform other functions.

[0093] According to the above control, since the distance between the plurality of nozzle rows 72 used at the same time is maintained to be the first distance Dl or more, the attachment of the powder material 200 to the nozzles 71 can be suppressed. In addition, by using a part of the nozzle rows 72 in the first time period and using the other part of the nozzle rows 72 in the second time period, the uneven use of only a part of the nozzle rows 72 can be avoided, and the life of the head unit 70 can be extended.

[0094] Further, in the above-described embodiment, the odd-numbered nozzle rows 72A, 72C, 72E, and 72G are used in a part of the time periods, and the even-numbered nozzle rows 72B, 72D, 72F, and 72H are used in the other part of the time periods, but the time period-based allocation of the used nozzle rows can vary depending on the arrangement of the nozzle rows. In addition, even if the arrangement of the nozzle rows is the same as described above, the time period-based allocation of the used nozzle rows is not limited to the above-described allocation. For example, the first nozzle row 72A and the fifth nozzle row 72E can be used in the first time period, the second nozzle row 72B and the sixth nozzle row 72F can be used in the second time period, the third nozzle row 72C and the seventh nozzle row 72G can be used in the third time period, and the fourth nozzle row 72D and the eighth nozzle row 72H can be used in the fourth time period. A plurality of nozzle rows can be used at the same time. The nozzle rows used at the same time are only required to be separated from each other by the first distance Dl or more (also including the case of being used alone), and are not further limited.

[0095] The above describes several preferred embodiments of the present application. However, the above-described embodiments are only examples, and the present application can be implemented in various other ways.

[0096] For example, in the above-described embodiment, the head unit is mounted on a carriage that moves in the main scanning direction. However, the three-dimensional modeling apparatus can also be configured in a so-called line head manner. In this case, the head unit can have a plurality of nozzle rows each extending in the main scanning direction, and can be stationary in the main scanning direction. Also, the plurality of nozzle rows can be arranged in the sub-scanning direction at intervals of a prescribed distance or more. Also, only a portion of the nozzle rows that are separated from each other by a prescribed distance or more in the sub-scanning direction can be used at the same time. The elongation direction and the arrangement direction of the nozzle rows are not particularly limited.

[0097] In the above-described embodiment, the positions of the plurality of nozzle rows in the sub-scanning direction are aligned. Also, their lengths are the same. However, the plurality of nozzle rows can also be configured in a so-called staggered configuration, and a portion or all of them can be misaligned in the sub-scanning direction.

[0098] The manner of ejection of the solidification liquid is not limited. The solidification liquid can be ejected by driving a piezoelectric element such as a piezoelectric element, or can be ejected by other various manners such as a thermal type. Also, the structure of the above-described three-dimensional modeling apparatus is merely an example, and is not particularly limited. Also, the ejection conditions of the solidification liquid, the kinds and characteristics of the solidification liquid and the powder material, the shape of the object being modeled, and the like are not limited unless specifically mentioned.

[0099] Furthermore, the embodiments disclosed herein are not limited to the present application unless specifically mentioned.

Claims

1. A three-dimensional modeling apparatus comprising: a modeling tank formed in a box shape having an opening portion at least in a part thereof, and accommodating a powder material; and an ejection device disposed so as to face the opening portion of the modeling tank, and ejecting a solidification liquid that solidifies the powder material toward the opening portion, wherein the ejection device has a plurality of nozzle rows each composed of a plurality of nozzles arranged in a predetermined first direction, the plurality of nozzles are configured to eject the solidification liquid respectively, and in each of the plurality of nozzle rows, the plurality of nozzles are arranged at a density of 1200 dpi or less in the first direction, the plurality of nozzle rows are arranged so as to be separated from each other by 5 mm or more in a second direction orthogonal to the first direction, the powder material is a mixed powder of a ceramic powder and a binder powder, and the solidification liquid is water to which a surfactant is added.

2. The three-dimensional modeling apparatus according to claim 1, wherein the plurality of nozzle rows are arranged so as to be separated from each other by 11 mm or more in the second direction.

3. A three-dimensional modeling apparatus comprising: a modeling tank formed in a box shape having an opening portion at least in a part thereof, and accommodating a powder material; and a control device that controls an ejection device to eject a solidification liquid, wherein the ejection device has: a first nozzle row composed of a plurality of nozzles arranged in a predetermined first direction and ejecting the solidification liquid respectively; a second nozzle row composed of other plurality of nozzles arranged in the first direction and ejecting the solidification liquid respectively; and a third nozzle row composed of still other plurality of nozzles arranged in the first direction and ejecting the solidification liquid respectively, in the first nozzle row, the plurality of nozzles are arranged at a density of 1200 dpi or less in the first direction, in the second nozzle row, the other plurality of nozzles are arranged at a density of 1200 dpi or less in the first direction, in the third nozzle row, the still other plurality of nozzles are arranged at a density of 1200 dpi or less in the first direction, the first nozzle row and the second nozzle row are arranged so as to be closer than a predetermined first distance in a second direction orthogonal to the first direction, the first nozzle row and the third nozzle row are arranged so as to be separated by the first distance or more in the second direction, the control device is configured to, in at least a part of a time in which the solidification liquid is ejected from the ejection device, eject the solidification liquid from the plurality of nozzles of the first nozzle row and the still other plurality of nozzles of the third nozzle row, and not to eject the solidification liquid from the other plurality of nozzles of the second nozzle row, the powder material is a mixed powder of a ceramic powder and a binder powder, the solidification liquid is water to which a surfactant is added, and the first distance is 5 mm or 11 mm.

4. The three-dimensional modeling apparatus according to claim 3, wherein the control device is configured to ​ ​ ​ ​ ​ ​ ​ ​ An ejection device is provided to face the opening portion of the molding groove, and a solidification liquid that solidifies the powder material is ejected toward the opening portion. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ in a portion of the time during which the solidification liquid is ejected from the ejection device, the solidification liquid is ejected from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row, and the solidification liquid is not ejected from the other plurality of nozzles of the second nozzle row, in another portion of the time during which the solidification liquid is ejected from the ejection device, the solidification liquid is ejected at least from the other plurality of nozzles of the second nozzle row, and the solidification liquid is not ejected from the plurality of nozzles of the first nozzle row.

5. The three-dimensional modeling apparatus according to claim 4, wherein the control device is provided with: a first counter that accumulates the time during which the solidification liquid is ejected from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row and the solidification liquid is not ejected from the other plurality of nozzles of the second nozzle row; a second counter that accumulates the time during which the solidification liquid is ejected at least from the other plurality of nozzles of the second nozzle row and the solidification liquid is not ejected from the plurality of nozzles of the first nozzle row; and a nozzle row selection section that, if the time accumulated by the first counter exceeds a prescribed time, suspends ejection of the solidification liquid from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row and ejects the solidification liquid from the other plurality of nozzles of the second nozzle row, and that, if the time accumulated by the second counter exceeds a prescribed time, suspends ejection of the solidification liquid at least from the other plurality of nozzles of the second nozzle row and ejects the solidification liquid from the plurality of nozzles of the first nozzle row.

6. The three-dimensional modeling apparatus according to claim 4, wherein the control device is provided with: a first counter that accumulates the number of times the solidification liquid is ejected from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row; a second counter that accumulates the number of times the solidification liquid is ejected from the other plurality of nozzles of the second nozzle row; and a nozzle row selection section that, if the number of times accumulated by the first counter exceeds a prescribed number of times, suspends ejection of the solidification liquid from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row and ejects the solidification liquid from the other plurality of nozzles of the second nozzle row, and that, if the number of times accumulated by the second counter exceeds a prescribed number of times, suspends ejection of the solidification liquid at least from the other plurality of nozzles of the second nozzle row and ejects the solidification liquid from the plurality of nozzles of the first nozzle row.

7. The three-dimensional modeling apparatus according to claim 4, wherein the control device is provided with: a first counter that accumulates the number of solidification layers formed by ejection of the solidification liquid from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row; a second counter that accumulates the number of solidification layers formed by ejection of the solidification liquid from the other plurality of nozzles of the second nozzle row; and a nozzle row selection section that, if the number of solidification layers accumulated by the first counter exceeds a prescribed number of layers, suspends ejection of the solidification liquid from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row and ejects the solidification liquid from the other plurality of nozzles of the second nozzle row, and that, if the number of solidification layers accumulated by the second counter exceeds a prescribed number of layers, suspends ejection of the solidification liquid at least from the other plurality of nozzles of the second nozzle row and ejects the solidification liquid from the plurality of nozzles of the first nozzle row. ​ ​ A nozzle row selection section, if the number of cured layers accumulated by the first counter exceeds a prescribed number, suspends ejection of the curing liquid from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row, and ejects the curing liquid from the other plurality of nozzles of the second nozzle row, and if the number of cured layers accumulated by the second counter exceeds a prescribed number, suspends ejection of the curing liquid from at least the other plurality of nozzles of the second nozzle row, and ejects the curing liquid from the plurality of nozzles of the first nozzle row.

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