CN115891147A - Three-dimensional modeling apparatus - Google Patents

Abstract

The invention provides a three-dimensional modeling device which prevents powder materials from being attached to a nozzle due to ejection of a solidification liquid. The three-dimensional modeling apparatus of the present invention includes: a shaping groove formed in a box shape having an opening at least in part and accommodating the powder material; and a spraying device (70) which is arranged in a manner of facing the opening part of the modeling groove and sprays the solidified liquid for solidifying the powder material to the opening part. The discharge 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 discharge the curing liquid, respectively, and are arranged in each nozzle row (72) at a density of 1200dpi or less in the first direction (X). The plurality of nozzle rows (72) are arranged apart from each other by 5mm or more in a second direction (Y) orthogonal to the first direction (X).

Description

Three-dimensional modeling apparatus

Technical Field

The present invention relates to a three-dimensional modeling apparatus.

Background

Conventionally, there is known an apparatus for producing a three-dimensional shaped object by forming a thin solidified layer having a desired cross-sectional shape by discharging a solidified liquid to a powder material and laminating the solidified layers. For example, patent document 1 discloses a three-dimensional molding apparatus including a molding tank in which an object to be molded is molded, a powder transfer unit that supplies a powder material to the molding tank, and a discharge head that discharges a solidification liquid for solidifying the powder material.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-126974

Disclosure of Invention

Problems to be solved by the invention

For example, in the three-dimensional molding machine of the powder curing type described in cited document 1, the powder material in the molding tank may fly due to ejection of the curing liquid. If the flying powder material adheres to the nozzle of the discharge head, the adhered powder material may be solidified by the solidifying liquid. When the powder material adhering to the nozzle is solidified, problems such as nozzle clogging and bending of the flight direction of the solidified liquid may occur.

The present invention has been made in view of the above problems, and an object thereof is to provide a three-dimensional modeling apparatus that suppresses adhesion of a powder material to a nozzle due to ejection of a solidification liquid.

Means for solving the problems

A first three-dimensional modeling apparatus disclosed herein includes: a shaping groove formed in a box shape having an opening at least in part and accommodating the powder material; and a discharge device that is provided so as to face the opening of the shaping tank and discharges a curing liquid that cures the powder material toward the opening. The discharge device has a plurality of nozzle rows each including a plurality of nozzles arranged in a predetermined first direction. The plurality of nozzles are configured to discharge the curing liquid, respectively, and are arranged in each of the plurality of nozzle rows at a density of 1200dpi or less in the first direction. The plurality of nozzle rows are arranged apart from each other by 5mm or more in a second direction orthogonal to the first direction.

According to the findings of the present inventors, if the density of the plurality of nozzles in the nozzle row of the three-dimensional modeling apparatus is set to be equal to or less than a certain level and the plurality of nozzle rows are arranged apart from each other by a distance equal to or more than a certain level, the powder material in the modeling tank can be prevented from flying due to the ejection of the solidified liquid. As a result, the adhesion of the powder material to the nozzle is suppressed. In the first three-dimensional modeling apparatus, the density of the plurality of nozzles in the nozzle row is set to 1200dpi or less, and the plurality of nozzle rows are arranged apart from each other by 5mm or more, so that the adhesion of the powder material to the nozzles due to the ejection of the solidification liquid can be suppressed.

Further, a second three-dimensional modeling apparatus disclosed herein includes: a shaping groove formed in a box shape having an opening at least in part and accommodating the powder material; a discharge device that is provided so as to face the opening of the shaping tank and discharges a solidified liquid that solidifies the powder material toward the opening; and a control device for controlling the ejection device to eject the curing liquid.

The discharge device includes a first nozzle row, a second nozzle row, and a third nozzle row. The first nozzle row is configured by a plurality of nozzles arranged in a predetermined first direction and discharging the curing liquid, respectively. The second nozzle row is configured by a plurality of other nozzles arranged in the first direction and configured to discharge the curing liquid. The third nozzle row is formed of another plurality of nozzles arranged in the first direction and configured to discharge the curing liquid. The first nozzle row and the second nozzle row are arranged closer to each other 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 apart from each other by the first distance or more in the second direction.

The control device is configured to discharge the curing liquid from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row during at least a part of a period of time during which the curing liquid is discharged from the discharge device, and to not discharge the curing liquid from the other plurality of nozzles of the second nozzle row.

According to the second three-dimensional modeling apparatus, the solidified liquid is not discharged from the nozzles of the second nozzle row that is at a distance from the first nozzle row that is smaller than the first distance, during at least a part of the time when the solidified liquid is discharged from the discharge device. Therefore, the curing liquid is not simultaneously discharged from the nozzles of the first nozzle row and the nozzles of the second nozzle row which are closer to each other than the first distance during the at least a part of the time. Accordingly, the adhesion of the powder material to the nozzle by the ejection of the solidification liquid can be suppressed for the same reason as in the first three-dimensional molding machine.

Drawings

Fig. 1 is a sectional view schematically showing a three-dimensional modeling apparatus according to a first embodiment.

Fig. 2 is a plan view schematically showing a three-dimensional modeling apparatus.

Fig. 3 is a plan view schematically showing a lower surface of the carriage.

Fig. 4 is a table showing the state of adhesion of the powder material to the nozzle based on the ejection conditions of the solidified liquid.

Fig. 5 is a plan view schematically showing a lower surface of a carriage of the three-dimensional modeling apparatus according to the second embodiment.

Fig. 6 is a block diagram of a three-dimensional modeling apparatus according to a second embodiment.

Description of the reference symbols

10. Three-dimensional modeling device

40. Supply tank

50. Molding groove

70. Head unit (Ejection device)

71. Nozzle with a nozzle body

72. Nozzle row

100. Control device

200. Powder material

210. Powder layer

D0 Distance between nozzle rows (first embodiment)

D1 First distance

D2 Second distance (distance between the first nozzle row and the second nozzle row)

D3 Third distance (distance between the first nozzle row and the third nozzle row)

Detailed Description

Hereinafter, a three-dimensional modeling apparatus according to an embodiment of the present invention will be described with reference to the drawings. It is needless to say that the embodiments described herein are not intended to limit the present invention in particular. The same reference numerals are given to the same components and portions, and the overlapping description is appropriately omitted or simplified.

Fig. 1 is a sectional view schematically showing a three-dimensional modeling apparatus 10 according to an embodiment. Fig. 2 is a plan view of the three-dimensional modeling apparatus 10. FIG. 1 is a section I-I of FIG. 2. In the figure, reference symbol F denotes the front and Rr the rear. Here, the left, right, up, and down when the three-dimensional modeling apparatus 10 is viewed from the direction of reference sign F are the left, right, up, and down of the three-dimensional modeling apparatus 10, respectively. The reference number L, R, U, D in the drawing indicates left, right, up, and down, respectively. Reference numeral X, Y, Z denotes 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 a sub-scanning direction of the three-dimensional modeling apparatus 10. The vertical direction Z is a stacking direction of the three-dimensional model. 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 convenience of explanation, and the arrangement of the three-dimensional modeling apparatus 10 is not limited at all.

As shown in fig. 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 apparatus 100. The modeling tank unit 12 is mounted with 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 forms a solidified layer 220 by discharging and solidifying a solidifying liquid to a desired position of the powder layer 210. Then, the solidified layer 220 is laminated on the upper side to mold the object to be molded 230.

As shown in fig. 2, the main body 11 is an exterior body of the three-dimensional modeling apparatus 10 having a shape elongated in the sub-scanning direction X. The main body 11 is formed in a box shape opened upward. The main body 11 houses the sub-scanning direction moving mechanism 20, the molding tank unit 12, and the control device 100. As shown in fig. 1, the main body 11 supports the roller unit 30 and the main scanning direction moving mechanism 80.

As shown in fig. 1, the modeling groove unit 12 is housed in the main body 11. The upper surface 12a of the shaping groove unit 12 is flat, and the shaping groove 50, the supply groove 40, and the powder recovery groove 60 are independently arranged in a line so as to be recessed from the upper surface 12 a.

The supply tank 40 is disposed on the rear side of the molding tank unit 12. The supply tank 40 stores the powder material 200 before being supplied to the shaping tank 50. As shown in fig. 1, the supply tank 40 includes a cylindrical portion 41 formed in a cylindrical shape extending in the vertical direction. As shown in fig. 2, the cylindrical portion 41 includes an opening 41a that opens upward. The shape of the opening 41a is rectangular in plan view. However, the planar shape of the opening 41a is not limited to a rectangle.

The composition, form, and the like of the powder material 200 are not particularly limited, and powder made of various materials such as a resin material, a metal material, and an inorganic material can be used. Examples of the powder material 200 include ceramic materials such as alumina, silica, titania, and zirconia, iron, aluminum, titanium, and alloys thereof (typically, stainless steel, titanium alloys, and aluminum alloys), hemihydrate gypsum (α -type gypsum, β -type gypsum), apatite, salt, and plastics. These may be made of any material, or two or more kinds may be combined. When the powder material 200 is a mixed powder, the particle sizes of the respective powders as the components may be different. For example, the powder to be the binder may be finer than the powder to be the aggregate.

Inside the cylindrical portion 41, a supply table 42 having the same shape as the cylindrical portion 41 in a plan view is housed. As shown in fig. 1, the supply table 42 has a shape on a flat plate. The supply table 42 is inserted into the cylindrical portion 41 substantially horizontally. The supply table 42 is configured to be vertically movable inside the cylindrical portion 41. A supply table lifting mechanism 43 is provided below the supply table 42. The supply table elevation mechanism 43 is configured to support and elevate the supply table 42. Here, the supply table lifting mechanism 43 supports the supply table 42 from below. The supply table elevation 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 a ball screw. By driving the drive motor 43b, the support portion 43a moves in the vertical direction. The supply table 42 is supported by the support portion 43a and moves in the vertical direction together with the support portion 43 a. The drive motor 43b is electrically connected to the control device 100 and controlled by the control device 100. The drive motor 43b is, for example, a servo motor, and is configured to be able to control the height of the supply table 42.

As shown in fig. 2, the shaping tank 50 is provided in front of the supply tank 40. The supply tank 40 and the shaping tank 50 are arranged in the sub-scanning direction X. The shaping groove 50 is arranged at a position aligned with the feed groove 40 in the main scanning direction Y. The shaping groove 50 is formed in a box shape and has an opening at least in part. Specifically, the shaping groove 50 includes a cylindrical portion 51 (see fig. 1) formed in a cylindrical shape extending in the vertical direction, and the cylindrical portion 51 includes an opening 51a opening upward. The molding groove 50 accommodates the powder material 200. The shaping groove 50 is a groove in which the powder material 200 shapes the object to be shaped 230. As shown in fig. 2, the shape of the opening 51a is rectangular in plan view. However, the planar shape of the opening 51a is not limited to a rectangle. The length of the opening 51a in the main scanning direction Y is the same as the length of the opening 41a of the supply tank 40 in the main scanning direction Y in plan view. However, the length of the opening 51a of the shaping groove 50 in the main scanning direction Y may be shorter than the length of the opening 41a of the supply groove 40 in the main scanning direction Y.

As shown in fig. 1, a modeling table 52 having the same shape as the cylindrical portion 51 in a plan view is housed inside the cylindrical portion 51. In the molding of the object 230, the powder material 200 is supplied to the molding table 52, and the molding is performed on the molding table 52. As shown in fig. 1, the modeling stage 52 has a shape on a flat plate. The modeling table 52 is inserted into the cylindrical portion 51 substantially horizontally. The modeling table 52 is configured to be vertically movable inside the cylindrical portion 51. A modeling table lifting mechanism 53 is provided below the modeling table 52. The modeling table lifting mechanism 53 is configured to support and lift the modeling table 52. Here, the modeling table lifting mechanism 53 supports the modeling table 52 from below. The modeling table lifting mechanism 53 includes a support portion 53a, a drive motor 53b, and a ball screw, 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 a 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 53 a. 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.

The powder recovery tank 60 is a tank for recovering the powder material 200 that cannot be stored in the molding tank 50 when the molding tank 50 is filled with the powder material 200. The powder recovery tank 60 is disposed in front of the shaping tank 50. As shown in fig. 2, the powder recovery tank 60, the shaping tank 50, and the supply tank 40 are arranged in the sub-scanning direction X. The powder recovery groove 60 is arranged at a position aligned with the shaping groove 50 in the main scanning direction Y. The powder recovery tank 60 includes an opening 60a that opens upward. The shape of the opening 60a is rectangular in plan view. However, the planar shape of the opening 60a is not limited to a rectangle. 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 length of the opening 51a of the shaping tank 50 in the main scanning direction Y in plan view. However, the length of the opening 60a of the powder recovery tank 60 in the main scanning direction Y may be longer than the length of the opening 51a of the shaping tank 50 in the main scanning direction Y.

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

As shown in fig. 1, the guide rail 21 guides the movement of the modeling groove unit 12 in the sub-scanning direction X. The guide rail 21 is provided in the main body 11. The guide rail 21 extends in the sub-scanning direction X. The molding groove unit 12 is slidably engaged with the guide rail 21. However, the installation position and number of the guide rails 21 are not particularly limited. The feed motor 22 is connected to the modeling tank unit 12 via, for example, a ball screw or the like. The feed motor 22 is electrically connected to the control device 100. The modeling groove unit 12 is moved on the guide rail 21 in the sub-scanning direction X by the rotational drive of the feed motor 22.

The sub-scanning direction moving mechanism 20 and the roller unit 30 constitute a layer forming device for flattening the powder material 200 supplied from the supply tank 40 on the shaping tank 50. The roller unit 30 includes a lay roller 31 and a roller support member 32 that supports the lay roller 31. The laying roller 31 is disposed above the main body 11. The laying roller 31 is disposed in front of the head unit 70. The laying roller 31 has an elongated cylindrical shape. The lay-up roller 31 is disposed with its cylindrical axis along the main scanning direction Y. The length of the lay-up roller 31 in the main scanning direction Y is longer than the modeling groove 50. The lower end of the laying roller 31 is provided slightly above the molding tank unit 12 so as to form a predetermined gap (clearance) with the upper surface 12a of the molding tank unit 12. The laying roller 31 is rotatably 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 be configured to be rotated by a motor or the like connected thereto, for example.

When the modeling tank unit 12 is moved backward by the sub-scanning direction moving mechanism 20, the paving roller 31 moves forward relative to the supply tank 40, the modeling tank 50, and the powder recovery tank 60. Therefore, at this time, the applicator roller 31 moves from above the supply tank 40 to above the powder recovery tank 60 through the shaping tank 50. At this time, the paving roller 31 moves from above the supply tank 40 to above the powder recovery tank 60 while maintaining a predetermined height above the supply tank 40, the molding tank 50, and the powder recovery tank 60.

As shown in fig. 2, 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 51a of the shaping groove 50. The head unit 70 is configured to discharge a curing liquid for curing the powder material 200 toward the opening 51a. The ejection mechanism of the curing liquid in the head unit 70 is not particularly limited, and an inkjet method or the like can be suitably used, for example. The head unit 70 is electrically connected to the control device 100 and controlled by the control device 100.

Fig. 3 is a plan view schematically showing a lower surface of the carriage 85. As shown in fig. 3, the head unit 70 has a plurality of nozzle rows 72 each including a plurality of nozzles 71. The plurality of nozzles 71 constituting each nozzle row 72 are arranged in the sub-scanning direction X. Each nozzle 71 is configured to discharge a curing liquid. Although only a small number of nozzles are illustrated in fig. 3, in the present embodiment, the plurality of nozzles 71 are arranged at a density of 1200dpi 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 may be arranged in each nozzle row 72 at a density smaller than 1200dpi, for example, a density of 360dpi or 720dpi in the sub-scanning direction X.

As shown in fig. 3, the head unit 70 includes a plurality of discharge heads 73. In the present embodiment, each of the plurality of discharge heads 73 has 1 nozzle row 72. The plurality of discharge heads 73 are arranged in the main scanning direction Y. Therefore, the plurality of nozzle rows 72 are also arranged in the main scanning direction Y. In the present embodiment, the plurality of nozzle rows 72 are arranged apart from each other by 11mm in the main scanning direction Y. Here, the distance D0 shown in fig. 3 is 11mm. The distance D0 between the nozzle rows 72 is 1 suitable distance, and may be longer or shorter than 11mm. However, the distance between the nozzle rows 72 is preferably 5mm or more. The reason for this will be described later.

The curing liquid is not particularly limited as long as it can fix the powder materials 200 to each other. In the curing liquid, a liquid (including a viscous body) capable of bonding particles constituting the powder material 200 to each other is used depending on the kind of the powder material 200. Examples of the curing liquid include liquids containing water, wax, a binder, and the like. In the case where the powder material 200 has a water-soluble resin as a sub-material, a liquid capable of dissolving the water-soluble resin, for example, water, may be used as the curing liquid. The water-soluble resin is not particularly limited, and examples thereof include starch, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), water-soluble acrylic resins, water-soluble polyurethane resins, and water-soluble polyamides.

The main scanning direction moving mechanism 80 moves the carriage 85 in the main scanning direction Y. As shown in fig. 2, the main scanning direction moving mechanism 80 includes a guide rail 81. The guide rail 81 extends in the main scanning direction Y. A carriage 85 is slidably engaged with the guide rail 81. The carriage 85 is connected to a carriage motor 82 (see fig. 1) via, for example, an endless belt and a pulley. By driving the carriage motor 82, the carriage 85 moves in the main scanning direction Y along the guide rail 81. The carriage motor 82 is electrically connected to the control device 100 and controlled by the control device 100. By the carriage 85 moving in the main scanning direction Y, the head unit 70 also moves in the main scanning direction Y.

As shown in fig. 1, an operation panel 150 is provided on the front surface of the main body 11. The operation panel 150 is provided with a display unit for displaying the status of the device, input keys operated by the user, and the like. The operation panel 150 is connected to the control device 100 that controls various operations of the three-dimensional modeling apparatus 10. The control device 100 is electrically connected to the feed motor 22, the drive motor 43b of the supply table elevation mechanism 43, the drive motor 53b of the modeling table elevation mechanism 53, the head unit 70, and the carriage motor 82, and controls the operations thereof.

The structure 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 examples thereof include an interface (I/F) for receiving model data and the like from an external device such as a host computer, a Central Processing Unit (CPU) for executing 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) used as a work area for developing the program, and a storage device such as a memory for storing the program and various data. The control device 100 is not necessarily provided inside the three-dimensional modeling apparatus 10, and may be a computer or the like provided outside the three-dimensional modeling apparatus 10 and communicably connected to the three-dimensional modeling apparatus 10 by wire or wireless, for example.

The three-dimensional modeling apparatus 10 models the object to be modeled 230, for example, by the following procedure. According to 1 preferred process, when the formation of 1 cured layer 220 is finished, the three-dimensional modeling apparatus 10 raises the supply table 42 and lowers the modeling table 52. At the point in time when the formation of the 1 solidified layer 220 ends, the upper surface of the powder material 200 on the feeding table 42 is located at the same height as that of the lower end portion of the paving roller 31. At this time, the upper surface of the solidified layer 220 formed uppermost in the modeling groove 50 is also located at the same height as the lower end of the laying roller 31.

When the supply table 42 is raised from this state, a part of the powder material 200 on the upper side overflows from the supply groove 40. The powder material 200 overflowing from the supply tank 40 becomes the powder material 200 supplied from the supply tank 40. The modeling table 52 is lowered by a predetermined distance from the above state. The prescribed distance is the same as the thickness of the solidified layer 220 to be formed next. The modeling table 52 reduces the amount of 1 layer thickness of the solidified layer 220 at the time of feeding of the powder material 200. This distance is for example 0.1mm.

Then, the three-dimensional modeling apparatus 10 moves the lay-up roller 31 forward with respect to the modeling tank unit 12. At this time, the laying roller 31 is substantially stationary, and the modeling tank unit 12 moves rearward. By this relative movement, the laying roller 31 moves from the rear of the supply tank 40 to the upper side of the powder recovery tank 60 through the supply tank 40 and the upper side of the shaping tank 50. A new powder material 200 is laid on the modeling groove stage 52 by the laying roller 31. Thereby, a new powder layer 210 is formed on the shaping table 52. The powder material 200 not laid on the molding tank table 52 falls into the powder recovery tank 60.

After a 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 discharge the solidified liquid to 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 object 230 is completed. This process is merely a preferable example, and the process of forming the object to be shaped 230 is not limited to this.

When the solidified liquid is discharged, the plurality of discharge heads 73 are vertically spaced apart from the powder layer 210 on the shaping tank 50 by a predetermined distance. Hereinafter, this distance is also referred to as a head gap. The head gap is a distance in the vertical direction between the lower surface (also referred to as a nozzle surface) of the discharge head 73 in which the nozzle row 72 is formed and the upper surface of the powder layer 210. The position of the upper surface of the powder layer 210 is equal to the position of the lower end of the laying roller 31 in the up-down direction. In the present embodiment, the head gap is 2mm. However, the head gap may be larger than 2mm or smaller than 2mm.

(problems of conventional three-dimensional modeling apparatus)

In the conventional three-dimensional molding machine of the powder solidification type, there is known a problem that the powder material in the molding groove flies up due to ejection of the solidification liquid. When the flying powder material adheres to the nozzle of the ejection head, the adhered powder material may be solidified by the solidifying liquid. When the powder material adhering to the nozzle is solidified, problems such as nozzle clogging and bending of the solidified liquid in the flight direction occur.

According to the findings of the inventors of the present application, such flying of the powder material is caused by an ascending air current generated by a large amount of droplets of the solidification liquid ejected from the head unit. Since a large number of droplets of the solidification liquid are ejected at high speed, air flows are generated in the spaces between the nozzles and the powder layer, respectively. According to the findings of the inventors of the present application, when 2 droplets of the solidification liquid are ejected at a close distance in the main scanning direction Y, the air flows generated by the two droplets interfere with each other to generate an updraft. The powder material is rolled up by the ascending air current.

Based on the above-described findings, the inventors of the present invention conceived the possibility that if 2 droplets of the solidification liquid are ejected at a distance more than a certain degree in the main scanning direction Y and the sub-scanning direction X, particularly in the main scanning direction Y, the air flows generated in both do not interfere with each other, and the generation of the ascending air flow is suppressed.

Therefore, in the three-dimensional modeling apparatus 10 according to the present embodiment, the plurality of nozzles 71 are arranged in the nozzle rows 72 at a density of 1200dpi in the sub-scanning direction X, and the plurality of nozzle rows 72 are arranged at a distance of 11mm 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 nozzle 71 in the three-dimensional modeling apparatus 10 according to the present embodiment is shown in comparison with other three-dimensional modeling apparatuses.

(ejection conditions of curing liquid and results of confirmation of powder Material adhesion)

Fig. 4 is a table showing the state of adhesion of the powder material to the nozzle based on the ejection conditions of the curing liquid. Fig. 4 shows the ejection conditions of the solidification liquid and the adhesion state of the powder material 200 in the three-dimensional modeling apparatus 10 according to the present embodiment. Fig. 4 shows the discharge conditions of the plurality of solidified liquids in the other three-dimensional modeling apparatus and the adhesion state of the powder material when the solidified liquids are discharged under the respective discharge conditions.

As shown in fig. 4, in the three-dimensional modeling apparatus 10 according to the present embodiment, the distance between the nozzle rows 72 is 11mm. The head gap was 2mm. The scanning speed of the carriage 85 is 150mm/s. The density of the nozzles 71 in the sub-scanning direction X is 1200dpi. The ejection density of the curing liquid in the main scanning direction Y was 1200dpi. The size (volume) of the droplets of the solidification liquid was 8pl (picoliters). The powder material 200 is a mixed powder of 85% ceramic powder + 15% binder powder, and has an average particle diameter of 50 μm. The curing liquid was water to which 5% of a surfactant was added. The thickness of 1 layer of the cured layer 220 was 0.1mm. As shown in fig. 4, under the ejection conditions, even after 100 cured layers 220 were formed, the powder material 200 was not observed to adhere to the nozzle 71.

On the other hand, in the other three-dimensional modeling apparatus, as shown in fig. 4, the distance between the plurality of nozzle rows is 2.3mm. This distance is smaller than that of the three-dimensional modeling apparatus 10 according to the present embodiment. The head clearance is 2mm as in the case of the three-dimensional modeling apparatus 10 according to the present embodiment. The carriage scanning speed is 150mm/s as in the case of the three-dimensional modeling apparatus 10 according to the present embodiment. The density of the nozzles in the sub-scanning direction was 180dpi. The ejection density of the curing liquid in the main scanning direction was 720dpi. The powder material and the solidified liquid are the same as those used in the three-dimensional modeling apparatus 10 according to the present embodiment. The thickness of the solidified layer and the discharge range (area) of the solidified liquid are the same as those in the three-dimensional modeling apparatus 10 according to the present embodiment. In other three-dimensional molding machines, the volume of the curing liquid was 11pl, 38pl, and 60 pl.

As shown in fig. 4, in other three-dimensional modeling apparatuses, the adhesion of the powder material to the nozzle has been confirmed after the formation of 3 solidified layers in the case of any size of the solidified liquid. As is clear from the results, the three-dimensional modeling apparatus 10 according to the present embodiment can suppress adhesion of the powder material to the nozzle as compared with the conventional three-dimensional modeling apparatus.

As for the ejection condition of the solidified liquid, it is considered that the same condition between the three-dimensional modeling apparatus 10 and the other three-dimensional modeling apparatus is not related to the above difference. Among the nozzles having different conditions, it is considered that the smaller the density of the nozzles in the sub-scanning direction, the smaller the density, the more the generation of the ascending air current can be suppressed, and the adhesion of the powder material can be reduced. In addition, regarding the ejection density of the solidified liquid in the main scanning direction, it is considered that the number of times of scanning by the carriage becomes smaller, and therefore, the adhesion of the powder material can be reduced. In the case of the test shown in fig. 4, the other three-dimensional modeling apparatus in which the density of the nozzles in the sub-scanning direction and the ejection density of the solidified liquid in the main scanning direction are small adheres more powder material than the three-dimensional modeling apparatus 10 according to the present embodiment. Therefore, it is considered that the suppression of the adhesion of the powder material is small in contribution of the density of the nozzles in the sub-scanning direction and the ejection density of the curing liquid in the main scanning direction.

In addition, the size of the curing liquid does not affect the test results of other three-dimensional modeling apparatuses. Therefore, the size of the solidified liquid is also considered to be an element that contributes little to the suppression of the adhesion of the powder material.

From these studies, it is considered effective to increase the distance between the nozzle rows in order to suppress the adhesion of the powder material to the nozzles. According to the test results of fig. 4, if the distance between the nozzle rows is 11mm 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 may be at least 1200dpi or less, and as long as 1200dpi or less, there is little effect on the adhesion of the powder material to the nozzles.

The present inventors have considered that the distance between the nozzle rows is made close within a range in which the adhesion of the powder material to the nozzles can be suppressed, the size of the head unit in the main scanning direction is made compact, and a predetermined ejection density can be achieved in the main scanning direction with a shorter scanning time.

According to the findings of the present inventors, when the plurality of nozzle rows are arranged apart from each other by 5mm or more in the main scanning direction Y, the powder material can be prevented from flying and adhering to the nozzles.

As is clear from the result of the solidified liquid ejection simulation, if the plurality of nozzle rows are separated from each other by 5mm or more, the generation of the updraft is reduced. Therefore, if the plurality of nozzle rows are arranged apart from each other by 5mm or more, it is considered that the powder material can be prevented from flying and adhering to the nozzles. However, the effect of this structure does not necessarily mean that the powder material is hardly adhered to the nozzles, and the amount of adhesion of the powder material can be reduced as compared with a conventional three-dimensional molding machine, for example, a three-dimensional molding machine in which the distance between nozzle rows is 2.3mm.

(second embodiment)

In the second embodiment, the plurality of nozzle rows are arranged at a distance shorter than a predetermined distance for suppressing the rolling-up of the powder material, but the number of nozzle rows used at the same time is limited. Thus, the distance between the nozzle rows used simultaneously is kept longer than a predetermined distance for suppressing the rolling-up of the powder material. In the following description of the second embodiment, the same reference numerals as those used in the first embodiment are used for members having the same functions as those in the first embodiment. In addition, duplicate descriptions are omitted or simplified as appropriate.

Fig. 5 is a plan view schematically showing a lower surface of a carriage 85 of the three-dimensional modeling apparatus 10 according to the second embodiment. As shown in fig. 5, in the present embodiment, each of the plurality of discharge heads 73 includes 2 nozzle rows 72. Here, the head unit 70 includes 4 discharge heads 73 arranged in the main scanning direction Y. Hereinafter, the plurality of nozzle rows 72 are referred to as a first nozzle row 72A to an eighth nozzle row 72H in order from left to right in order to distinguish the plurality of nozzle rows 72 from each other. The plurality of discharge heads 73 are referred to as a first head 73A, a second head 73C, a third head 73E, and a fourth head 73G in this order from left to right in order to distinguish the plurality of discharge heads 73 from each other. However, the number of the discharge heads 73 is not particularly limited, and the number of the nozzle rows 72 formed in the discharge heads 73 is also not particularly limited.

As shown in fig. 5, 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.

The first nozzle row 72A to the eighth nozzle row 72H are each configured by a plurality of nozzles 71 arranged in a row in the sub-scanning direction X and each ejecting the curing liquid. As shown in fig. 5, the first nozzle row 72A and the second nozzle row 72B are arranged closer to each other than a predetermined first distance D1 in the main scanning direction Y. Specifically, the first nozzle row 72A and the second nozzle row 72B are arranged apart from each other by a second distance D2 smaller than the first distance D1 in the main scanning direction Y. The first distance D1 is a distance between the nozzle rows 72 that can suppress the rolling up of the powder material 200. The first distance D1 may be set to 5mm, for example. Alternatively, the first distance D1 may be set to a distance greater than 5mm and smaller than 11mm. The first distance D1 may also be set to 11mm.

On the other hand, the first nozzle row 72A and the third nozzle row 72C are disposed apart from each other by a first distance D1 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 greater than the first distance D1. However, the third distance D3 may be equal to the first distance D1. Similarly, the third nozzle row 72C and the fourth nozzle row 72D are arranged apart from each other by a second distance D2 in the main scanning direction Y. The third nozzle row 72C and the fifth nozzle row 72E are arranged apart from each other by a third distance D3 in the main scanning direction Y. The fifth nozzle row 72E and the sixth nozzle row 72F are arranged at a second distance D2 in the main scanning direction Y. The fifth nozzle row 72E and the seventh nozzle row 72G are arranged apart from each other by a third distance D3 in the main scanning direction Y. The seventh nozzle row 72G and the eighth nozzle row 72H are arranged apart from each other by a second distance D2 in the main scanning direction Y.

Therefore, although not shown, the distance between the second nozzle row 72B and the fourth nozzle row 72D, the distance between the fourth nozzle row 72D and the sixth nozzle row 72F, and the distance between the sixth nozzle row 72F and the eighth nozzle row 72H in the main scanning direction Y are all the third distance D3.

The control device 100 according to the present embodiment is configured to cause the curing liquid to be discharged 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 to cause the curing liquid not to be discharged 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 for part of the time when the curing liquid is discharged from the head unit 70. Specifically, the control device 100 according to the present embodiment causes the curing liquid to be discharged 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 does not cause the curing liquid to be discharged 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, in a part of the time (hereinafter, referred to as a first time zone) during which the curing liquid is discharged from the head unit 70. In fig. 5, the nozzles 71 that eject the curing liquid in the first period are indicated by double circles.

The control device 100 according to the present embodiment is configured to cause the curing liquid to be discharged 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 to cause the curing liquid not to be discharged 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, in the other part (hereinafter, referred to as a second time zone) of the time for discharging the curing liquid from the head unit 70. In fig. 5, the nozzles 71 that eject the curing liquid in the second period are indicated by triangles.

However, the control device 100 may be configured to discharge the curing liquid 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 discharge the curing liquid 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, during all of the discharge time of the curing liquid from the head unit 70. Alternatively, the control device 100 may be configured to cause the curing liquid to be discharged 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 to cause the curing liquid not to be discharged 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, during all of the time for discharging the curing liquid from the head unit 70. In other words, the three-dimensional modeling apparatus 10 may 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.

Fig. 6 is a block diagram of the three-dimensional modeling apparatus 10 according to the present embodiment. As shown in fig. 6, in the present embodiment, the control device 100 includes a first counter 110, a second counter 120, a nozzle column selection unit 130, and a timing correction unit 140. The first counter 110 is configured to measure the cumulative time during which the curing liquid is discharged from the odd-numbered nozzle rows 72A, 72C, 72E, and 72G (in other words, the cumulative time of the first time zone). When the time accumulated by the first counter 110 exceeds a predetermined time, the even-numbered nozzle rows 72B, 72D, 72F, and 72H are used from the formation of the next solidified layer 220. The second counter 120 is configured to measure the cumulative time (in other words, the cumulative time of the second time zone) of the ejection of the curing liquid from the even-numbered nozzle rows 72B, 72D, 72F, and 72H. 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 solidified layer 220.

The nozzle column selecting section 130 selects the nozzle column 72 to be used, based on the measurements of the first counter 110 and the second counter 120. The timing correction section 140 corrects the timing of discharging the curing liquid according to the selected nozzle row 72.

However, this control is merely a preferable example, and the method of control related to selection of the nozzle row 72 is not limited. For example, the first time zone and the second time zone may be switched for each predetermined number of shots of the curing liquid. The first counter 110 in this case is configured to count the number of times the curing liquid is discharged from the odd-numbered nozzle rows 72A, 72C, 72E, and 72G. In this case, the second counter 120 is configured to count the number of times the curing liquid is discharged from the even-numbered nozzle rows 72B, 72D, 72F, and 72H. Alternatively, the first period and the second period may be switched every time the predetermined number of cured layers 220 are formed. The first time zone and the second time zone may be switched for each job. In these cases, the first counter 110 and the second counter 120 accumulate the number of solidified layers 220 or the number of operations.

Although the description and the drawings are omitted, the control device 100 may include another control unit that performs another function.

According to the above control, since the distance between the plurality of nozzle rows 72 used simultaneously is maintained at the first distance D1 or more, the adhesion of the powder material 200 to the nozzles 71 can be suppressed. Further, by using a part of the nozzle rows 72 in the first time zone and using the other part of the nozzle rows 72 in the second time zone, 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.

In addition, in the above-described embodiment, the odd-numbered nozzle rows 72A, 72C, 72E, and 72G are used in some of the slots, and the even-numbered nozzle rows 72B, 72D, 72F, and 72H are used in other of the slots, but the allocation of the nozzle rows to be used based on the slots may vary depending on the arrangement of the nozzle rows. Even if the arrangement of the nozzle rows is the same as described above, the allocation of the nozzle rows to be used based on the time zone is not limited to the above allocation. For example, the first nozzle row 72A and the fifth nozzle row 72E may be used in the first period, the second nozzle row 72B and the sixth nozzle row 72F may be used in the second period, the third nozzle row 72C and the seventh nozzle row 72G may be used in the third period, and the fourth nozzle row 72D and the eighth nozzle row 72H may be used in the fourth period. Only 1 nozzle column may be used at a time. The nozzle rows used simultaneously are not limited to a specific one as long as they are separated from each other by the first distance D1 or more (including the case of being used alone).

Several preferred embodiments of the present invention have been described above. However, the above embodiments are merely examples, and the present invention can be implemented in various other embodiments.

For example, in the above-described embodiment, the head unit is mounted on the carriage that moves in the main scanning direction. However, the three-dimensional modeling apparatus may be configured as a so-called line head system. In this case, the head unit may have a plurality of nozzle rows extending in the main scanning direction, respectively, and may be stationary in the main scanning direction. The plurality of nozzle rows may be arranged in the sub-scanning direction at intervals equal to or greater than a predetermined interval. Further, only a part of the nozzle rows that are separated from each other by a predetermined distance or more in the sub-scanning direction may be used simultaneously. The extending direction and the arrangement direction of the nozzle rows are not particularly limited.

In the above-described embodiment, the positions of the plurality of nozzle rows in the sub-scanning direction are aligned. In addition, they are the same length. However, the plurality of nozzle rows may be arranged in a so-called staggered arrangement, and a part or all of them may be shifted in position in the sub-scanning direction.

The ejection method of the curing liquid is not limited. The curing liquid may be discharged by driving a piezoelectric element such as a piezoelectric element, or may be discharged by other various methods such as a thermal type. The structure of the three-dimensional molding machine is merely an example, and is not particularly limited. The ejection conditions of the curing liquid, the types and properties of the curing liquid and the powder material, the shape of the object to be molded, and the like are not limited unless otherwise specified.

The embodiments disclosed herein are not intended to limit the present invention unless otherwise specified.

Claims (9)

1. A three-dimensional modeling apparatus includes:

a shaping groove formed in a box shape having an opening at least in part and accommodating the powder material; and

a discharge device that is provided so as to face the opening of the molding tank and discharges a curing liquid for curing the powder material toward the opening,

the discharge device has a plurality of nozzle rows each including a plurality of nozzles arranged in a predetermined first direction,

the plurality of nozzles are configured to discharge the curing liquid, respectively, and are arranged in each of the plurality of nozzle rows at a density of 1200dpi or less in the first direction,

the plurality of nozzle rows are arranged apart from each other by 5mm or more in a second direction orthogonal to the first direction.

2. The three-dimensional modeling apparatus according to claim 1,

the plurality of nozzle rows are arranged apart from each other by 11mm or more in the second direction.

3. A three-dimensional modeling apparatus includes:

a shaping groove formed in a box shape having an opening at least in part and accommodating the powder material;

a discharge device that is provided so as to face the opening of the shaping tank and discharges a solidified liquid that solidifies the powder material toward the opening; and

a control device for controlling the ejection device to eject the curing liquid,

the ejection device includes:

a first nozzle row configured from a plurality of nozzles arranged in a predetermined first direction and configured to discharge the curing liquid, respectively;

a second nozzle row configured from a plurality of other nozzles arranged in the first direction and configured to discharge the curing liquid, respectively; and

a third nozzle row including a plurality of other nozzles arranged in the first direction and configured to discharge the curing liquid,

the first nozzle row and the second nozzle row are arranged closer to each other 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 apart from each other by the first distance or more in the second direction,

the control device is configured to discharge the curing liquid from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row during at least a part of a period of time during which the curing liquid is discharged from the discharge device, and to not discharge the curing liquid from the other plurality of nozzles of the second nozzle row.

4. The three-dimensional modeling apparatus according to claim 3,

the control means is set to control the operation of the motor,

wherein the solidified liquid is discharged from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row during a part of the time for discharging the solidified liquid from the discharge device, and the solidified liquid is not discharged from the other plurality of nozzles of the second nozzle row,

in another part of the time period during which the solidified liquid is discharged from the discharge device, the solidified liquid is discharged from at least the other plurality of nozzles of the second nozzle row, and the solidified liquid is not discharged from the plurality of nozzles of the first nozzle row.

5. The three-dimensional modeling apparatus according to claim 4,

the control device is provided with:

a first counter that counts a time during which the curing liquid is discharged from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row, and the curing liquid is not discharged from the other plurality of nozzles of the second nozzle row;

a second counter that counts a time during which the curing liquid is discharged from at least the other plurality of nozzles of the second nozzle row and the curing liquid is not discharged from the plurality of nozzles of the first nozzle row; and

and a nozzle column selecting section that stops the ejection of the curing liquid from the plurality of nozzles of the first nozzle column and the other plurality of nozzles of the third nozzle column and ejects the curing liquid from the other plurality of nozzles of the second nozzle column when the time accumulated by the first counter exceeds a predetermined time, and stops the ejection of the curing liquid from at least the other plurality of nozzles of the second nozzle column and ejects the curing liquid from the plurality of nozzles of the first nozzle column when the time accumulated by the second counter exceeds a predetermined time.

6. The three-dimensional modeling apparatus according to claim 4,

the control device is provided with:

a first counter configured to count the number of times the curing liquid is discharged from the plurality of nozzles of the first nozzle row and the other plurality of nozzles of the third nozzle row;

a second counter configured to count the number of times the curing liquid is discharged from the other plurality of nozzles of the second nozzle row; and

and a nozzle column selecting section that stops the 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 when the number of times counted by the first counter exceeds a predetermined number of times, and stops the 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 when the number of times counted by the second counter exceeds the predetermined number of times.

7. The three-dimensional modeling apparatus according to claim 4,

the control device is provided with:

a first counter that counts the number of solidified layers formed by the solidified liquid discharged 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 counts the number of solidified layers formed by the ejection of the solidified liquid from the other plurality of nozzles of the second nozzle row; and

and a nozzle column selecting section that stops the 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 when the number of cured layers integrated by the first counter exceeds a predetermined number, and stops the 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 when the number of cured layers integrated by the second counter exceeds the predetermined number.

8. The three-dimensional modeling apparatus according to any one of claims 3-7,

the first distance is 5mm.

9. The three-dimensional modeling apparatus according to any one of claims 3-7,

the first distance is 11mm.

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