阅读说明：本技术 立体物造形方法 (Method for forming three-dimensional object ) 是由 八角邦夫 于 2020-02-12 设计创作，主要内容包括：本发明提供一种能够在立体物的内部较容易地形成空洞的立体物造形方法。立体物造形方法是通过在作业面层叠墨层来形成层叠体的立体物造形方法,该立体物造形方法包括：空隙部形成工序,在作业面上或者在形成于作业面的墨层的最上层的包围预定区域的范围层叠墨层,从而形成由墨包围的空隙部；和悬垂部形成工序,对于要包含空隙部的墨层层叠新的墨层的情况,在面向空隙部的墨上配置新的墨时,通过设为使墨的一部分以空隙部的外形形状不崩溃的范围的层叠角度向空隙部的内侧突出了的状态,从而形成随着朝向上方而自空隙部的外周侧向内侧伸出且包围空隙部的悬垂部。(The invention provides a three-dimensional object forming method capable of easily forming a cavity in the three-dimensional object. The three-dimensional object forming method is a three-dimensional object forming method for forming a laminated body by laminating an ink layer on a working surface, and the three-dimensional object forming method comprises the following steps: a void portion forming step of forming a void portion surrounded by ink by stacking ink layers on the working surface or in a region surrounding a predetermined region of the uppermost layer of the ink layers formed on the working surface; and an overhanging portion forming step of forming, when a new ink layer is stacked on an ink layer to include the void portion, an overhanging portion that protrudes from an outer peripheral side of the void portion toward an inner side and surrounds the void portion as it goes upward by providing a state in which a part of the ink protrudes toward the inner side of the void portion at a stacking angle within a range in which an outer shape of the void portion does not collapse when the new ink is disposed on the ink facing the void portion.)

1. A three-dimensional object forming method for forming a laminate by laminating ink layers on a working surface,

the three-dimensional object shaping method comprises the following steps:

a void portion forming step of forming a void portion surrounded by the ink by stacking the ink layer on the working surface or in a range surrounding a predetermined region of an uppermost layer of the ink layer formed on the working surface; and

and an overhanging portion forming step of forming an overhanging portion that protrudes from an outer peripheral side of the void portion toward an inner side and surrounds the void portion as it goes upward by providing a state in which a part of the ink protrudes toward the inner side of the void portion at a stacking angle in a range in which an outer shape of the void portion does not collapse when a new layer of the ink is disposed on the ink facing the void portion in a case where the new layer of the ink is to be stacked on the layer of the ink including the void portion.

2. The solid object modeling method according to claim 1,

the three-dimensional object shaping method further comprises the following steps: and a hollow portion forming step of forming a hollow portion by disposing the ink on the suspended portion to close the hollow portion.

3. The solid object modeling method according to claim 1 or 2,

the suspended portion forming step includes: a plurality of layers of the ink are arranged to overlap the ink, a part of which protrudes inward of the gap.

4. The solid object modeling method according to claim 3,

in the suspended portion forming step, the ink is superimposed in layers such that an angle formed by the working surface and a wall surface inside the suspended portion is 60 ° or more and 90 ° or less.

5. The solid object modeling method according to claim 1 or 2,

the ink is dropped at a predetermined pitch in a matrix form in a plan view,

in the suspended portion forming step, the ink is dropped so that the drop position of the ink is shifted by 1 pitch to the inside of the void portion, and a state is formed in which a part of the ink protrudes to the inside of the void portion.

6. The solid object modeling method according to claim 1 or 2,

the void portion forming step includes: overlapping layers of the ink in a range surrounding the predetermined region.

7. The solid object modeling method according to claim 6,

the void portion forming step includes: overlapping the layers of ink in a manner that widens the void.

8. The solid object modeling method according to claim 2,

in the void portion forming step, a plurality of void portions are formed,

in at least one of the suspended portion forming step and the hollow portion forming step, a portion between the plurality of void portions is formed as a reinforcing portion formed by the ink.

9. The solid object modeling method according to claim 1 or 2,

the laminate includes at least one of a laminate formed of a modeling material and a laminate formed of a support material for supporting the modeling material.

Background

Conventionally, for a three-dimensional object molded by laminating molding materials by a three-dimensional printer, a technique for forming a cavity in the three-dimensional object has been known for the purpose of, for example, reducing the weight and material cost (see, for example, patent documents 1 and 2).

Disclosure of Invention

Problems to be solved by the invention

However, the methods disclosed in patent documents 1 and 2 are as follows: a recess is formed in the laminated body, and after the recess is closed by a cover member or a solid body, a new ink layer is laminated on the cover member or the solid body to provide an internal cavity in the three-dimensional object. In this case, for example, if the cap member or the solid material is obliquely clogged, the cap member or the solid material interferes with the head that ejects ink, so that it is difficult to form a three-dimensional object having a cavity, which may cause a failure. Therefore, the process of closing the recess with the lid member or the solid material requires strict accuracy both automatically and manually.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a three-dimensional object forming method capable of relatively easily forming a suspended portion surrounding a void portion.

Means for solving the problems

The three-dimensional object forming method of the present invention is a three-dimensional object forming method for forming a laminate by laminating an ink layer on a working surface, the three-dimensional object forming method including: a void portion forming step of forming a void portion surrounded by the ink by stacking the ink layers on the working surface or in a region surrounding a predetermined region of an uppermost layer of the ink layers formed on the working surface; and forming an overhanging portion that protrudes from an outer peripheral side of the void portion toward an inner side and surrounds the void portion as it goes upward by providing a state in which a part of the ink protrudes toward the inner side of the void portion at a stacking angle within a range in which an outer shape of the void portion does not collapse when a new ink layer is to be stacked on the ink layer including the void portion, when the new ink layer is disposed on the ink facing the void portion.

According to the present invention, the void portion can be formed in a part of the ink layer, and the overhanging portion can be formed inward from the outer peripheral side of the void portion at a stacking angle within a range in which the outer shape of the void portion does not collapse. This makes it possible to easily form the suspended portion surrounding the void portion.

In the above three-dimensional object forming method, the three-dimensional object forming method further includes: and a hollow portion forming step of forming a hollow portion by disposing the ink on the suspended portion to close the hollow portion. This makes it possible to easily form the hollow portion inside the three-dimensional object. Further, compared to a method in which a hollow portion is formed by providing a concave portion in the three-dimensional object and blocking the hollow portion with a cover member or a solid material, the cover member or the solid material is not necessary, and the degree of freedom in designing the arrangement, the volume, and the like of the hollow portion is improved.

In the above three-dimensional object forming method, the suspended portion forming step may include: a plurality of layers of the ink are arranged to overlap the ink, a part of which protrudes inward of the gap. This increases the angle formed by the working surface and the wall surface inside the suspended portion, and therefore the shape of the suspended portion can be stabilized without collapsing.

In the three-dimensional object forming method, the ink may be superimposed in the suspended portion forming step in such a manner that the angle formed by the working surface and the wall surface inside the suspended portion is 60 ° or more and 90 ° or less. This makes it possible to sufficiently increase the angle formed by the working surface and the wall surface inside the suspended portion, and thus to stabilize the shape of the suspended portion without collapsing.

In the three-dimensional object forming method, the ink may be dropped in a matrix form at a predetermined pitch in a plan view, and in the suspended portion forming step, the ink may be dropped so that a dropping position of the ink is shifted by 1 pitch to an inner side of the gap portion, so that a part of the ink protrudes to the inner side of the gap portion. This makes it possible to easily realize a state in which a part of the ink protrudes to the inside of the void portion.

In the above three-dimensional object forming method, the void portion forming step may include: overlapping a plurality of the ink layers in a range surrounding the predetermined area. This makes it possible to form the cavity portion wider in the vertical direction.

In the above three-dimensional object forming method, the void portion forming step may include: the ink layers are overlapped in such a manner as to widen the gap portion. This makes it possible to form the cavity portion wider in the planar direction.

In the three-dimensional object forming method, the void portion forming step may form a plurality of void portions, and at least one of the overhanging portion forming step and the hollow portion forming step may form a portion between the plurality of void portions as a reinforcing portion formed by the ink. This ensures the strength of a three-dimensional object having a plurality of hollow portions inside the three-dimensional object.

In the above-described three-dimensional object forming method, the laminate may include at least one of a laminate formed of a forming material and a laminate formed of a supporting material for supporting the forming material. This can save the molding material and the supporting material.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention can provide a method for forming a three-dimensional object, which can form a cavity in the three-dimensional object easily.

Drawings

Fig. 1 is a schematic view showing a three-dimensional object forming apparatus used in the three-dimensional object manufacturing method according to the present embodiment.

Fig. 2 is an explanatory view of the ejection unit as viewed from the ejection surface side of the ink droplets.

Fig. 3 is a functional block diagram showing an example of the control unit.

Fig. 4 is a diagram showing an example of a cross-sectional structure of a three-dimensional object manufactured by the three-dimensional object manufacturing method according to the embodiment.

Fig. 5 is a cross-sectional view showing an example of the hollow portion.

Fig. 6 is a perspective view showing an example of the hollow portion.

Fig. 7 is a perspective view showing another example of the hollow portion.

Fig. 8 is a cross-sectional view showing another example of the hollow portion.

Fig. 9 is a cross-sectional view showing another example of the hollow portion.

Fig. 10 is a cross-sectional view showing another example of the hollow portion.

Fig. 11 is a perspective view showing an example of the hollow portion.

Fig. 12 is a diagram showing an example of a case where a plurality of hollow portions are arranged in the shaping portion.

Fig. 13 is a ZX cross-sectional view of fig. 12.

Fig. 14 is a flowchart showing an example of the three-dimensional object manufacturing method according to the present embodiment.

Fig. 15 is a view showing a manufacturing process of the three-dimensional object manufacturing method.

Fig. 16 is a diagram showing an example of the shape of ink.

Fig. 17 is a diagram showing an example of a case where the suspended portion is formed by virtual ink droplets.

Fig. 18 is a flowchart showing an example of processing for adding hole data to three-dimensional data.

Fig. 19 is a flowchart showing an example of processing in the case of editing hole data.

Description of the reference numerals

F1, bottom face; f2, vertical plane; f3, overhanging surface; f4, outer inclined surface; r0, uppermost layer; r1, R2, Rn, layer; s10, forming a gap; s20, forming a hanging part; s30, forming a hollow part; AR, area; pv, pitch; 10. a three-dimensional object modeling device; 12. an ejection unit; 14. a main scanning drive section; 16. a shaping table; 16a, a working surface; 18. a control unit; 22. a carriage; 24. a guide rail; 32c, 32k, 32m, 32y, color ink jet heads; 34. a head for a modeling material; 36. a head for white ink; 38. a nozzle for transparent ink; 40. a nozzle for supporting material; 44. an ultraviolet light source; 50. a flattening roller unit; 51. a roller section; 52. a residual modeling material recovery mechanism; 60. a three-dimensional object; 61. a shaping part; 61H, an overhanging portion; 61P, a reinforcement part; 62. a support portion; 63. 63A, 63B, 63C, 63D, a hollow portion; 64. shaping an inner cavity part; 65. a hollow part in the supporting object; 66. void, 70, ink droplet; 71. an imaginary ink droplet; 181. a three-dimensional data input unit; 182. a three-dimensional data output unit; 183. an input operation unit; 184. a processing unit; 185. a calculation unit; 186. a selection unit; 187. a hole data generation changing unit; 188. a storage unit; 189. display unit

Detailed Description

Hereinafter, embodiments of the three-dimensional object forming method according to the present invention will be described with reference to the drawings. The present invention is not limited to the embodiment. The components of the following embodiments include components that can be easily replaced by those skilled in the art or substantially equivalent components.

Fig. 1 is a schematic view showing a three-dimensional object forming apparatus 10 used in the three-dimensional object manufacturing method according to the present embodiment. The three-dimensional object forming apparatus 10 shown in fig. 1 is a three-dimensional printer for forming a three-dimensional object 5 by a lamination forming method. In this case, the lamination molding method is a method of molding the three-dimensional object 5 by stacking a plurality of layers, for example. The three-dimensional object 5 is, for example, a three-dimensional structure. The three-dimensional object forming method executed by the three-dimensional object forming apparatus 10 may be, for example, a color forming method for forming a three-dimensional structure based on shape information and color image information of the three-dimensional structure.

In addition, except for the following points, the three-dimensional object forming device 10 preferably has the same or similar structure as a known three-dimensional object forming device. The three-dimensional object forming apparatus 10 is preferably obtained by, for example, modifying a part of the configuration of an ink jet printer, which is a known printing apparatus for printing on a flat surface. For example, the three-dimensional object forming apparatus 10 is preferably a device obtained by changing a part of an ink jet printer using ultraviolet curable ink (UV ink).

The three-dimensional object forming apparatus 10 of the present embodiment includes: the discharge unit 12, the main scanning drive unit 14, a shaping table 16 as a table on which the three-dimensional object 5 is placed, and a control unit 18. The discharge unit 12 is a portion that discharges droplets of a material to be the three-dimensional object 5, and discharges droplets of a curable resin or the like that is a resin that is cured under predetermined conditions, and the droplets are cured to form each layer constituting the three-dimensional object 5. More specifically, the ejection unit 12 repeats, for example, a plurality of times of a layer forming operation of ejecting droplets to form a curable resin layer in accordance with an instruction from the control unit 18 and a curing operation of curing the curable resin layer formed by the layer forming operation. The discharge unit 12 repeats these operations, and a plurality of cured curable resin layers are stacked.

In the three-dimensional object forming apparatus 10 according to the present embodiment, the ejection unit 12 ejects ink droplets of colored ultraviolet curable ink to color the surface or the interior of the three-dimensional object 5 and form the colored three-dimensional object 5. As shown in fig. 1, the discharge unit 12 forms the support 6 around the three-dimensional object 5 when the three-dimensional object 5 is shaped. The support 6 is a laminated structure (support layer) for supporting the three-dimensional object 5 during the formation, and is dissolved and removed with water or the like after the formation of the three-dimensional object 5 is completed.

The main scanning drive unit 14 is a drive unit that causes the discharge unit 12 to perform a main scanning operation. Note that, in the present embodiment, the main scanning operation of the ejection unit 12 means, for example, the main scanning operation of an inkjet head included in the ejection unit 12. The main scanning operation is an operation of ejecting ink droplets while moving in a preset main scanning direction (Y direction in the drawing), for example.

The main scanning drive unit 14 includes a carriage 22 and a guide rail 24. The carriage 22 is a holding portion that faces the shaping table 16 and holds the discharge unit 12. That is, the carriage 22 holds the ejection unit 12 so that the ejection direction of the ink droplets ejected from the ejection unit 12 is directed toward the shaping table 16. In the main scanning operation, the carriage 22 moves along the guide rail 24 while holding the discharge unit 12. The guide rail 24 is a rail member that guides the movement of the carriage 22, and moves the carriage 22 in accordance with an instruction from the control unit 18 during the main scanning operation.

Among them, the movement of the discharge unit 12 in the main scanning operation is preferably a relative movement with respect to the three-dimensional object 5. Therefore, in a modification of the configuration of the three-dimensional object modeling apparatus 10, for example, the position of the discharge unit 12 may be fixed, and the modeling table 16 may be moved to move the side of the three-dimensional object 5.

The shaping table 16 is a table on which the three-dimensional object 5 under shaping is placed on a working surface 16a as an upper surface. The shaping table 16 has a function of moving the working surface 16a in the vertical direction (Z direction in the drawing), and moves the working surface 16a in accordance with the progress of shaping of the three-dimensional object 5 in accordance with an instruction from the control unit 18. This enables the distance (gap) between the surface to be shaped of the three-dimensional object 5 and the discharge unit 12 to be appropriately adjusted during the shaping. The surface to be shaped of the three-dimensional object 5 in this case means a surface on which the next layer is to be formed by the discharge means 12. The scanning in the Z direction for moving the shaping table 16 up and down with respect to the ejection unit 12 may be performed by moving the ejection unit 12 in the Z direction.

The control unit 18 is a device that controls each part of the three-dimensional object forming device 10, and the control unit 18 includes a CPU (central processing unit) that functions as a controller for executing various processes, a RAM (random access memory) and a ROM (read only memory) that function as memories for storing various information, and the like. The control unit 18 controls each unit of the three-dimensional object modeling apparatus 10 based on the shape information, the color image information, and the like of the three-dimensional object 5 to be modeled, and controls the operation for modeling the three-dimensional object 5.

The three-dimensional object forming device 10 preferably further includes various structures required for forming and coloring the three-dimensional object 5. For example, the three-dimensional object modeling apparatus 10 may include a sub-scanning drive unit or the like that causes the discharge unit 12 to perform a sub-scanning operation. In this case, the sub-scanning operation is an operation of moving the inkjet head of the ejection unit 12 relative to the three-dimensional object 5 in the shape in a sub-scanning direction (X direction in the drawing) orthogonal to the main scanning direction, for example. For example, in the case of shaping the three-dimensional object 5 having a length in the sub-scanning direction longer than the shaping width of the inkjet head of the ejection unit 12, the sub-scanning driving unit causes the ejection unit 12 to perform the sub-scanning operation as necessary. More specifically, the sub-scanning drive unit may be a drive unit that moves the shaping table 16 in the sub-scanning direction, or may be a drive unit that moves the guide rail 24 in the sub-scanning direction together with the carriage 22 that holds the discharge unit 12.

Fig. 2 is an explanatory view of the ejection unit as viewed from the ejection surface side of the ink droplets. The discharge unit 12 includes a plurality of color ink heads 32y, 32m, 32c, and 32k (hereinafter, referred to as a plurality of color ink heads 32y to 32k), a white ink head 36, a clear ink head 38, a modeling material head 34, a support material head 40, a plurality of ultraviolet light sources 44, and a flattening roller unit 50.

The color ink heads 32y to 32k, the white ink head 36, the clear ink head 38, and the modeling material head 34 are heads as ejection means for ejecting droplets of a curable resin by an ink jet method. These color ink heads 32Y to 32k, white ink head 36, clear ink head 38, and modeling material head 34 are inkjet heads that eject ink droplets of ultraviolet-curable ink, and are aligned in the sub-scanning direction (X direction) and arranged in the main scanning direction (Y direction).

The color ink heads 32y to 32k are inkjet heads that eject ink droplets of color inks of different colors, respectively. The color ink heads 32Y to 32K can eject ink droplets of ultraviolet curable inks of respective colors of yellow (Y), magenta (M), cyan (C), and black (K). The white ink head 36 is an ink jet head that ejects ink droplets of ultraviolet curable ink of white (W).

The modeling material head 34 is an ink jet head that discharges ink droplets of ultraviolet-curable ink as a modeling material that has fluidity and is used to form a three-dimensional object. The modeling material head 34 can eject ink droplets of a modeling ink (MO) of a predetermined color. As the shaping ink, for example, white ink or clear ink may be used.

The clear ink head 38 is an ink jet head that ejects ink droplets of ultraviolet-curable clear ink. The clear ink is transparent (T) ink. The transparent ink is an ink containing an ultraviolet-curable resin and no colorant.

The supporting material ejection head 40 is an ink jet head that ejects ink droplets containing the material (S) of the support 6 (see fig. 1). The material of the support 6 in this case is an ultraviolet-curable ink, and a water-soluble material that can be dissolved by water after the three-dimensional object 5 is shaped is preferably used. As the material of the support 6, a known material for the support 6 can be suitably used. The support material heads 40 are aligned in the sub-scanning direction with the color ink heads 32y to 32k, the white ink head 36, the clear ink head 38, and the shaping material head 34, and are arranged in parallel in the main scanning direction.

Among them, as the color ink heads 32y to 32k, the white ink head 36, the clear ink head 38, the modeling material head 34, and the support material head 40, for example, a known inkjet head can be suitably used. These inkjet heads have a nozzle row in which a plurality of nozzles are arranged in the sub-scanning direction on a surface facing the shaping table 16 (see fig. 1). In this case, the nozzle rows of the respective ink jet heads are arranged in the same direction and in parallel with each other. During the main scanning operation, ink droplets are ejected in the Z direction while moving in the main scanning direction perpendicular to the direction in which the nozzles are arranged.

The plurality of ultraviolet light sources 44 are ultraviolet light sources for curing ultraviolet curable ink, and ultraviolet LEDs (light emitting diodes), metal halide lamps, mercury lamps, and the like can be used. The plurality of ultraviolet light sources 44 are disposed on one end side and the other end side in the main scanning direction of the discharge unit 12 with the color ink heads 32y to 32k, the white ink head 36, the clear ink head 38, the modeling material head 34, and the support material head 40 interposed therebetween. The three-dimensional object modeling apparatus 10 according to embodiment 1 is provided with UV1 and UV2 as the ultraviolet light source 44, and UV1 is disposed on the left end side in the main scanning direction (Y direction) of the ejection unit 12 and is turned on when the ejection unit 12 performs main scanning in the right direction relative to the modeling table 16. The UV2 is disposed on the right end side of the discharge unit 12 in the main scanning direction (Y direction), and is turned on when the discharge unit 12 performs main scanning in the left direction relative to the shaping table 16. Here, depending on the curing sensitivity of the ink by ultraviolet rays, there may be a case where both UV1 and UV2 are lit at the same time, and further, only one of UV1 and UV2 may be provided without the other.

The flattening roller unit 50 is configured to flatten the ultraviolet-curable ink layer formed in the formation of the three-dimensional object 5 and to make the thickness of the layer constant. The flattening roller unit 50 is disposed between the row of the color ink heads 32y to 32k, the white ink head 36, the clear ink head 38, the modeling material head 34, and the support material head 40, and UV2 as the ultraviolet light source 44 disposed on the other end side of the discharge unit 12. Thus, the flattening roller units 50 are aligned in the main scanning direction in accordance with the positions of the rows of the color ink heads 32y to 32k, the white ink head 36, the clear ink head 38, the modeling material head 34, and the support material head 40 in the sub-scanning direction. The flattening roller unit 50 is provided in the ejection unit 12 so as to be movable in the vertical direction with respect to the ejection unit 12, and is brought into contact with the ink layer in a downward-moved state to keep the layer thickness constant. The flattening roller unit 50 includes: a roller portion 51 that rotates in the clockwise direction and scrapes off excess modeling material out of the flowable modeling material by moving in the main scanning direction (left direction in the figure) together with the carriage 22; and a surplus modeling material recovery mechanism 52 that recovers surplus modeling material scraped off by the roller portion 51 (see fig. 1).

Fig. 3 is a functional block diagram showing an example of the control unit 18. In the present embodiment, by the control of the control unit 18, a three-dimensional object 60 (see fig. 4) having, for example, a shaping portion 61, a supporting portion 62, and a cavity portion 63, which will be described later, can be manufactured in addition to the three-dimensional object 5. As shown in fig. 3, the control unit 18 includes: a three-dimensional data input unit 181, a three-dimensional data output unit 182, an input operation unit 183, a processing unit 184, a calculation unit 185, a selection unit 186, a hole data generation change unit 187, a storage unit 188, and a display unit 189.

The three-dimensional data input unit 181 is used to input three-dimensional data from an input source, not shown, such as a server or a personal computer. The three-dimensional data input to the three-dimensional data input unit 181 does not include cavity data relating to the position of the cavity 63 and parameters (size, volume, etc.). The three-dimensional data output unit 182 outputs the three-dimensional data processed by the processing unit 184. The three-dimensional data output from the three-dimensional data output unit 182 may include hole data. The input operation unit 183 can input predetermined operation data using an input device such as an operation button, a mouse, or a keyboard.

The processing unit 184 generates additional data obtained by adding cavity data relating to the position of the cavity 63, parameters, and the like to the three-dimensional data input from the three-dimensional data input unit 181. The processing unit 184 outputs the generated additional data to the three-dimensional data output unit 182.

The calculation unit 185 calculates parameters such as the shape, size, and volume of an attachable region to which the hole data can be attached to the three-dimensional data. The selection unit 186 selects hole data to be added to the three-dimensional data from the pattern of holes stored in the storage unit 188 based on each parameter of the attachable area calculated by the calculation unit 185.

The hole data generation changing unit 187 generates new hole data to be stored in the storage unit 188, based on the input result from the input operation unit 183, for example. The hole data generation change unit 187 edits the parameters of the hole data stored in the storage unit 188 based on the input result from the input operation unit 183, for example.

The storage unit 188 stores a plurality of hole data. For example, the storage unit 188 stores preset standard hole data and newly generated non-standard hole data.

The display unit 189 uses a display device such as a liquid crystal display. The display unit 189 can display the data output from the processing unit 184. For example, the display unit 189 can display the three-dimensional data or the additional data generated by the processing unit 184.

Next, a three-dimensional object manufacturing method using the embodiment of the three-dimensional object forming apparatus 10 will be described. Fig. 4 is a diagram showing an example of a cross-sectional structure of a three-dimensional object 60 manufactured by the three-dimensional object manufacturing method according to the embodiment. In the present embodiment, the three-dimensional object 60 is, for example, a bird, but is not limited to this, and may be a three-dimensional shape modeled by a person, a car, a building, a drink, a food, or the like.

As shown in fig. 4, the three-dimensional object 60 includes: a shaping portion 61, a support portion 62, and a hollow portion 63. The shaping portion 61 is formed into a three-dimensional shape such as a bird using a shaping material. The color of the surface of the shaping portion 61, for example, the appearance of a bird, may be formed using a color ink. The support portion 62 is formed of a support material. The hollow portion 63 includes a shaping inner hollow portion 64 and a support inner hollow portion 65. The shaping inner cavity 64 is a cavity formed inside the shaping portion 61. The support inner cavity 65 is a cavity formed inside the support portion 62. Hereinafter, the molding inner cavity 64 and the support inner cavity 65 will be referred to as "cavities" without distinction.

Fig. 5 is a cross-sectional view showing an example of the hollow portion 63. Hollow portion 63A shown in fig. 5 has bottom surface F1, vertical surface F2, and suspended surface F3. The bottom surface F1 is, for example, a plane parallel to the working surface 16 a. The vertical plane F2 is a plane perpendicular to the work surface 16a and the bottom surface F1, for example. The vertical surfaces F2 are disposed at both ends in the left-right direction in fig. 5.

The hanging plane F3 is formed by the hanging portion 61H of the shaping portion 61. The hanging portion 61H is a portion of the shaping portion 61 that protrudes inward of the cavity 63A as it goes upward. The inner wall surface of the suspended portion 61H is a suspended surface F3. Suspended surface F3 is a plane inclined at an angle θ to the inside of hollow 63A with respect to a plane parallel to working surface 16a, for example. The angle θ is preferably 60 ° or more and 90 ° or less, for example. The hanging surface F3 is not limited to a flat surface, and may include a curved surface. In this case, the angle between the tangent plane of the curved surface and the plane parallel to the working surface 16a is preferably 60 ° or more and 90 ° or less.

Fig. 6 is a perspective view showing an example of the hollow portion 63A. As shown in fig. 6, the hollow portion 63A shown in fig. 5 can be regarded as having a structure in which: with 5 faces such as F1, F2, F3 and two faces of a pentagon that are not overhanging perpendicular (ZY-faces). Fig. 7 is a perspective view showing another example of the hollow portion 63A. For example, as shown in fig. 7, the hollow portion 63A may have a cylindrical cross-sectional structure having a cone suspended at the upper end. The overhang angle θ in this case is also preferably 60 ° or more and 90 ° or less.

Fig. 8 is a cross-sectional view showing another example of the hollow portion 63. The hollow portion 63B shown in fig. 8 has a bottom surface F1 and a hanging surface F3. The hollow portion 63B is configured such that a vertical surface F2 is not provided with respect to the hollow portion 63A. The overhang angle θ in this case is also preferably 60 ° or more and 90 ° or less.

Fig. 9 is a cross-sectional view showing another example of the hollow portion 63. Hollow portion 63C shown in fig. 9 has bottom surface F1, vertical surface F2, and suspended surface F3. The bottom surface F1 of the cavity 63C may be curved or bent along the outer shape of the shaping portion 61, instead of being a plane parallel to the working surface 16 a. The angle θ of the hanging surface F3 in this case is also preferably 60 ° or more and 90 ° or less.

Fig. 10 is a cross-sectional view showing another example of the hollow portion 63. The hollow 63D shown in fig. 10 has an outer inclined surface F4 and a hanging surface F3. The angle θ of the hanging surface F3 in this case is also preferably 60 ° or more and 90 ° or less. The outer inclined surface F4 is a flat surface inclined outward of the hollow portion 63D from the lower end of the hollow portion 63D upward. The outer inclined surface F4 is not limited to a flat surface, and may include a curved surface. Fig. 11 is a perspective view showing an example of the hollow portion 63D.

Fig. 12 is a diagram showing an example of a case where a plurality of hollow portions 63D are arranged in the shaping portion 61. Fig. 13 is a ZX cross-sectional view of fig. 12. Fig. 12 is a ZY sectional view of fig. 13. As shown in fig. 12 and 13, the hollow portions 63D are arranged such that the hanging surface F3 of one faces the outer inclined surface F4 of the other between the adjacent hollow portions 63D.

A reinforcement portion 61P is formed around the plurality of hollow portions 63D of the shaping portion 61. The reinforcement portion 61P is formed in a plate shape between the adjacent hollow portions 63D and between the overhanging surface F3 of one and the outer inclined surface F4 of the other. In the example shown in fig. 12, for example, the reinforcing portion 61P is formed in a beam shape, for example, at a portion between the corners of the cross-sectional shape of the cavity 63D. In this way, the beam-shaped reinforcement portion 61P and the plate-shaped reinforcement portion 61P are formed between the plurality of hollow portions 63D. Here, the plate-like reinforcement portion 61P formed between the one suspended surface F3 and the other outer inclined surface F4 is also a portion constituting the suspended portion 61H. The shape of the reinforcement portion 61P is not limited to a plate shape or a beam shape, and may be other shapes. The same description can be made for the case where the hollow portion 63 is disposed in the support portion 62.

Next, a specific method for manufacturing the three-dimensional object 60 will be described. Fig. 14 is a flowchart showing an example of the three-dimensional object manufacturing method according to the present embodiment. Fig. 15 is a view showing a manufacturing process of the three-dimensional object manufacturing method. As shown in fig. 14, the three-dimensional object forming method of the present embodiment includes a void portion forming step (step S10), a suspended portion forming step (step S20), and a hollow portion forming step (step S30).

In the void portion forming step S10, as shown in fig. 15 (a), the ink layer R1 is laminated on the working surface 16a or in a range surrounding the predetermined region AR of the uppermost layer R0 of the ink formed on the working surface 16a, thereby forming the void portion 66 surrounded by the ink. In the void portion forming step S10, a plurality of ink layers may be superimposed in the vertical (Z) direction in a range surrounding the predetermined region AR. In this case, the hollow portion 63 can be formed wide in the vertical direction. In the void portion forming step S10, the ink layers may be superimposed in the vertical (Z) direction so that the void portion 66 is widened as it goes upward. In this case, the hollow portion 63 can be formed to be wide in the planar direction.

In the suspended portion forming step S20, as shown in fig. 15 (B), when a new ink layer R2 is to be stacked on the ink layer R1 including the void portion 66 and a new ink is to be placed on the ink facing the void portion 66, the suspended portion 61H is formed so as to protrude inward from the outer peripheral side of the void portion 66 as it goes upward by making a part of the ink protrude inward from the void portion 66.

The suspended portion forming step S20 may include: a plurality of layers of ink are arranged to overlap the ink partially protruding into the space 66. Accordingly, the angle formed by working surface 16a and suspended surface F3 is increased, and thus the shape of suspended portion 61H can be stabilized.

In the suspended portion forming step S20, the inks are superimposed in layers such that the angle θ formed by the working surface 16a and the suspended surface F3 is 60 ° or more and 90 ° or less. This makes it possible to sufficiently increase the angle θ, and thus to stabilize the shape of the suspended portion 61H.

In addition, ink is dropped in a matrix shape at a predetermined pitch Pv in a plan view, and in suspended portion forming step S20, ink is dropped with the drop position of ink shifted by 1 pitch to the inside of void portion 66, so that a part of the ink protrudes to the inside of void portion 66. This makes it possible to easily realize a state in which a part of the ink protrudes into the space 66.

Fig. 16 is a diagram showing an example of the shape of ink. As shown in fig. 16, the ink droplets 70 ejected from the ejection unit 12 on, for example, a plane are formed in a circular shape in a plan view. As shown in a side view, the ink droplet 70 is formed in a shape that rises upward from the outer peripheral portion of the ink droplet 70 toward the central portion.

Such ink droplets 70 can be set as, for example, virtual ink droplets 71 that are square in plan view. That is, when the pitch of the ink droplets 70 ejected from the ejection unit 12, that is, the reciprocal of the resolution is denoted as Pv, the virtual ink droplets 71 can be set to be ink droplets having a square shape with a length V on one side, and the length V satisfies the requirement

V＝3Pv。

In the case of the ejection unit 12 that ejects the ink droplets 70 with a resolution of 600dpi for example,

pv is 42 μm (1 inch/600 point),

V＝126μm。

in this case, the thickness t of the virtual ink droplet 71 can be a value obtained by dividing the volume of the ink droplet 70 by the square area of the virtual ink droplet 71. In the present embodiment, for example, the number of the grooves can be set to

t＝18μm。

Fig. 17 is a diagram showing an example of a case where the suspended portion 61H is formed by the virtual ink droplet 71. In the present embodiment, in the case of forming the overhanging portion 61H, ink is disposed so that ink protrudes to the side of the void portion 66 by 1 pitch. When the angle θ between the plane parallel to the working surface 16a and the hanging surface F3 is 60 ° or more, new ink is superimposed on the ink protruding toward the void 66 side and stacked as shown in fig. 17. When the number of layers of the superimposed ink is denoted by N (where N is a natural number), this can be expressed as

tanθ＝N·t/Pv。

In the present embodiment, when Pv is 42 μm and t is 18 μm, for example, θ ≈ 60 ° when N is 4 layers. Therefore, when N ≧ 4, that is, in a state where 4 or more layers of ink are stacked, by arranging the new ink so that it projects to the side of the gap 66 by 1 pitch, it is possible to form the suspended portion 61H having the suspended surface F3 where θ is substantially 60 ° or more by repeating such an operation. The value of the natural number N is not limited to 4 or more, and can be set as appropriate according to, for example, the pitch Pv, the length V of one side of the virtual ink droplet 71, and the thickness t.

By repeating the suspended portion forming step S20, the area of the upper portion of the void portion 66 gradually decreases. Here, the hollow portion forming step S30 is performed. In the hollow portion forming step S30, as shown in fig. 15 (C), the ink layer Rn is disposed on the suspended portion 61H to close the upper portion of the void portion 66. After the hollow portion 63 is formed, the shaping portion 61 is formed until the outer contour of the three-dimensional object 60 is obtained.

In the above-described void portion forming step S10, the plurality of void portions 66 may be formed first, and in at least one of the suspended portion forming step S20 and the hollow portion forming step S30, the portions between the plurality of void portions 66 may be formed as the reinforcing portions 61P formed by the ink. This enables the plurality of hollow portions 63 to be efficiently formed inside the three-dimensional object 60, and the strength of the three-dimensional object 60 to be ensured.

In the three-dimensional object forming method described above, the hollow portion 63 can be formed in at least one of the forming portion 61, which is a laminated body formed of a forming material, and the supporting portion 62, which is a laminated body formed of a supporting material, as the three-dimensional object 60. This can save the molding material and the supporting material.

Next, a process of generating three-dimensional data (additional data) for modeling the three-dimensional object 60 will be described. Fig. 18 is a flowchart showing an example of processing for adding hole data to three-dimensional data. As shown in fig. 18, when the three-dimensional data is input to the three-dimensional data input unit 181 (step S101), the processing unit 184 determines whether or not to add the hole data (step S102). In step S102, the processing unit 184 displays a guidance screen for guiding whether or not to input additional hole data to the input operation unit 183 on the display unit 189. Then, the processing unit 184 determines whether or not to add hole data based on the input content of the input operation unit 183.

When the hole data is added (yes in step S102), it is determined whether or not the hole data is added to the data corresponding to the shaping portion 61 in the three-dimensional data (step S103), and whether or not the hole data is added to the data corresponding to the supporting portion 62 in the three-dimensional data (step S104). In step S103 and step S104, the processing unit 184 determines whether or not to add hole data based on the input content of the input operation unit 183, as in step S102.

When the hole data is added (yes in step S103 and yes in step S104), the hole data to be added is selected from the hole data stored in the storage unit 188 (step S105). In step S105, for example, the calculation unit 185 calculates each parameter of the attachable area, and the selection unit 186 selects the hole data based on the calculation result of the calculation unit 185.

After the hole data is selected, the processing unit 184 determines whether or not the hole data is automatically arranged (step S106). In step S106, the processing unit 184 determines whether or not to automatically arrange the hole data based on the input content of the input operation unit 183. If the hole data is not automatically arranged (no in step S106), the operator arranges the hole data by manual work (step S107). When the hole data is automatically arranged (yes in step S106), the processing unit 184 generates additional data obtained by adding the hole data to the three-dimensional data based on the selected hole data. Then, the processing unit 184 determines whether or not the adding process of the hole data is finished based on the input content of the input operation unit 183 (step S108).

When it is determined in step S108 that the adding process is ended (yes in step S108), or when it is determined in step S102 or step S104 that the hole data is not added (no in step S102, no in step S104), the processing unit 184 determines whether or not the shaping operation is started based on the input content of the input operation unit 183 (step S109). When the shaping operation is performed (yes in step S109), a control signal to start the shaping operation is output to the ejection unit 12 (step S110). When the shaping operation is not performed (no in step S109), the shaping operation is not performed and the process is terminated.

Fig. 19 is a flowchart showing an example of processing in the case of editing hole data. As shown in fig. 19, the processing unit 184 determines whether or not to newly generate non-standard hole data that is not stored in the storage unit 188, based on the input content of the input operation unit 183 (step S201). When new generation is performed (yes in step S201), the hole data generation changing unit 187 generates new hole data that can be stored in the storage unit 188, for example, based on the input result from the input operation unit 183 (step S202). After the new hole data is generated, it is determined whether or not the generated hole data is stored in the storage unit 188 (step S203). If it is determined to be stored (yes in step S203), the selection unit 186 newly stores the generated hole data in the storage unit 188 (step S204). If it is determined not to store (no in step S203), the processing after step S201 is repeated.

When new generation is not performed (no in step S201), or after new hole data is stored in step S204, the processing unit 184 determines whether or not to change existing hole data stored in the storage unit 188, based on the input content of the input operation unit 183 (step S205). When it is determined that the change is to be made (yes in step S205), the hole data generation changing unit 187 changes each parameter of the hole data stored in the storage unit 188 based on the input result from the input operation unit 183, for example (step S206). After each parameter of the hole data is changed, the processing unit 184 determines whether or not the changed hole data is stored in the storage unit 188 based on the input content of the input operation unit 183 (step S207). If it is determined to be stored (yes at step S207), it is determined whether or not to replace (step S208). If it is determined to be replaced (yes in step S208), the selection unit 186 stores the changed hole data in the storage unit 188 in a replacement manner (step S209). If it is determined that the replacement is not to be performed (no in step S208), the selection unit 186 newly stores the changed hole data in the storage unit 188 (step S210).

If it is determined in step S205 that the hole data is not to be changed (no in step S205), if replacement storage is performed in step S209, or if new storage is performed in step S210, the process ends.

As described above, according to the present invention, the suspended portion 61H surrounding the void portion 66 can be easily formed by forming the void portion 66 in a part of the ink layer R1 and forming the suspended portion 61H inward from the outer peripheral side of the void portion 66.

Further, by disposing ink on the suspended portion 61H to block the hollow portion 63, the three-dimensional object 60 having the hollow portion 63 therein can be formed relatively easily. This makes it possible to easily form the hollow portion 63 inside the three-dimensional object 60. In addition, compared with a method in which a concave portion is provided in the three-dimensional object and the hollow portion is formed by closing with a cover member, the degree of freedom in designing the arrangement, the volume, and the like of the hollow portion 63 is improved.

In the three-dimensional object forming method described above, in the suspended portion forming step S20, a plurality of layers of ink may be superimposed on the ink in a state in which a portion protrudes inward of the void portion 66. Accordingly, since the angle θ formed by the working surface 16a and the hanging surface F3 is increased, the shape of the hanging portion 61H can be stabilized.

In the three-dimensional object forming method described above, in the suspended portion forming step S20, the inks are superimposed in layers such that the angle θ formed by the working surface 16a and the suspended surface F3 is 60 ° or more and 90 ° or less. Accordingly, since angle θ formed by work surface 16a and suspended surface F3 can be sufficiently increased, suspended portion 61H can be stabilized in shape. However, the closer the angle θ is to 90 °, the more stable the formation of the overhanging surface can be made, but the total volume of the void becomes smaller, and the ink saving amount decreases. Conversely, as the angle θ approaches 60 °, the formation of the overhanging surface becomes more unstable, but the total volume of the void becomes larger, and the ink saving amount increases. The angle θ also depends on the physical properties of the ink, and as the viscosity and surface tension are higher, the suspended surface can be formed more stably even at a smaller angle, for example, 50 °.

In the three-dimensional object forming method described above, ink is dropped in a matrix form at a predetermined pitch Pv in a plan view, and in suspended portion forming step S20, ink is dropped so that the dropped position of ink is shifted by 1 pitch to the inside of gap 66, and a state is formed in which a part of ink protrudes to the inside of gap 66. This makes it possible to easily realize a state in which a part of the ink protrudes into the space 66.

In the above three-dimensional object forming method, the void portion forming step S10 may include: the multi-layer ink layer R1 is overlapped in a range surrounding the predetermined area AR. This allows the cavity 63 to be formed wider vertically.

In the above three-dimensional object forming method, the void portion forming step S10 may include: the ink layer R1 is overlapped so as to widen the void 66. Thus, the hollow portion 63 can be formed wide in the planar direction.

In the three-dimensional object forming method described above, the plurality of voids 66 may be formed in the void forming step S10, and the portions between the plurality of voids 66 may be formed as the reinforcing portions 61P formed with ink in at least one of the suspended portion forming step S20 and the hollow portion forming step S30. This enables the plurality of hollow portions 63 to be efficiently formed inside the three-dimensional object 60, and the strength of the three-dimensional object 60 to be ensured.

In the three-dimensional object forming method, the three-dimensional object 60 may include at least one of a forming portion 61 that is a laminated body formed of a forming material and a support portion 62 that is a laminated body formed of a support material for supporting the forming material. This can save the molding material and the supporting material.

In addition, although the above-described three-dimensional object forming method has been described as a forming method using an ultraviolet-curable ink, the forming method may be a forming method using a thermoplastic ink, that is, an ink which is laminated by dissolving by heating and is cured after returning to room temperature. Thus, no ultraviolet light source is required.

The technical scope of the present invention is not limited to the above-described embodiments, and modifications may be appropriately made within the scope not departing from the gist of the present invention.