Three-dimensional structure and manufacturing method thereof

Abstract

To provide a method capable of easily manufacturing a three-dimensional structure including a shaft part and a shaft-receiving part that have little backlash.SOLUTION: A three-dimensional structure 1 includes: a base member 2 including shaft-receiving parts 23A, 23B; and a lid member 3 extending in an axle direction and including shaft parts 34A, 34B rotatably connected to the shaft-receiving parts 23A, 23B. The base member 2 and the lid member 3 are fabricated by a lamination molding method. The shaft parts 34A, 34B of the lid member 3 include a plurality of top faces 42 disposed in a peripheral direction and a plurality of connection parts 45 that connects adjacent top faces 42s in a peripheral direction. The top faces 42 face internal peripheral faces 26A of shaft holes 26 of the shaft-receiving parts 23A, 23B at a position apart from the internal peripheral faces 26A of the shaft holes 26 in a radial direction by a minimum gap distance D. The connection parts 45 are positioned farther away from the internal peripheral faces 26A of the shaft holes 26 in the radial direction than the top faces 42.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a three-dimensional structure and a manufacturing method thereof, and more particularly to a manufacturing method of a three-dimensional structure including a shaft portion and a bearing portion that receives the shaft portion. [Background technology]

[0002] Conventionally, there has been known an additive manufacturing method in which a three-dimensional structure is formed by stacking materials one layer at a time using a 3D printer. Such an additive manufacturing method is also used when producing a three-dimensional structure including a shaft portion and a bearing portion that receives the shaft portion (for example, see Patent Document 1). When producing such a three-dimensional structure by the additive manufacturing method, the shaft portion and the bearing portion may adhere to each other during modeling or secondary curing, which may impair the functions of the shaft portion and the bearing portion. Such adhesion can be suppressed by ensuring a sufficient gap between the shaft portion and the bearing portion, but if the gap between the shaft portion and the bearing portion is made large, rattling is likely to occur when the shaft portion rotates relative to the bearing portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-12981 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made in consideration of such problems in the conventional technology, and has a first object to provide a three-dimensional structure including a shaft portion and a bearing portion with little rattle.

[0005] A second object of the present invention is to provide a method for easily manufacturing a three-dimensional structure including a shaft portion and a bearing portion with little rattle. [Means for solving the problem]

[0006] According to a first aspect of the present invention, there is provided a three-dimensional structure including a shaft portion and a bearing portion with little rattle. The three-dimensional structure includes a first member including a bearing portion having a bearing surface, and a second member including a shaft portion extending along an axial direction and rotatably connected to the bearing portion. The shaft portion of the second member has a plurality of top surfaces arranged along a circumferential direction, the plurality of top surfaces facing the bearing surface of the bearing portion at a position radially spaced a predetermined distance from the bearing surface of the bearing portion, and a plurality of connection portions connecting adjacent top surfaces among the plurality of top surfaces in the circumferential direction, the plurality of connection portions being located radially farther away from the bearing surface of the bearing portion than the plurality of top surfaces.

[0007] According to a second aspect of the present invention, there is provided a method for easily manufacturing a three-dimensional structure including a shaft portion and a bearing portion with little rattle. This method is a method for manufacturing a three-dimensional structure including a first member including a bearing portion having a bearing surface, and a second member including a shaft portion extending along an axial direction and rotatably connected to the bearing portion. This method includes an additive manufacturing process for stacking a first material layer and a second material layer in a stacking direction to form the first member made of the first material layer and the second member made of the second material layer. The additive manufacturing process includes a shaft structure forming process for forming the bearing portion and the shaft portion by repeating, in the stacking direction, a continuous layer forming process for continuously forming the first material layer and the second material layer on the same stacking plane. In the shaft structure forming process, the first material layer forms the bearing surface of the bearing part, and the second material layer forms a plurality of top surfaces arranged along a circumferential direction, which face the bearing surface at a position radially away from the bearing surface of the bearing part by a predetermined distance, and a plurality of connection portions connecting adjacent top surfaces among the plurality of top surfaces in the circumferential direction, which are located radially farther from the bearing surface of the bearing part than the plurality of top surfaces. [Brief description of the drawings]

[0008] [Figure 1]FIG. 1 is a perspective view showing a three-dimensional structure in one embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the three-dimensional structure shown in FIG. [Figure 3A] FIG. 3A is a cross-sectional view of a base member in the three-dimensional structure shown in FIG. [Figure 3B] FIG. 3B is an enlarged view of a portion of the cross section taken along line AA in FIG. 3A. [Figure 4A] 4A is an enlarged perspective view showing a part of the lid member in the three-dimensional structure shown in FIG. [Figure 4B] FIG. 4B is a front view of a portion of the lid member shown in FIG. 4A. [Figure 4C] FIG. 4C is a plan view of a portion of the lid member shown in FIG. 4A. [Diagram 5] FIG. 5 is an enlarged cross-sectional view showing a part of the three-dimensional structure shown in FIG. [Figure 6A] FIG. 6A is a flow chart showing an example of a process for manufacturing a three-dimensional structure in one embodiment of the present invention. [Figure 6B] FIG. 6B is a flowchart showing a part of the additive manufacturing process shown in FIG. 6A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of a three-dimensional structure and a manufacturing method thereof according to the present invention will be described in detail with reference to Figs. 1 to 6B. In Figs. 1 to 6B, identical or corresponding components are denoted with the same reference numerals, and duplicated descriptions will be omitted. In addition, in Figs. 1 to 6B, the scale and dimensions of each component may be exaggerated, or some components may be omitted. In the following description, unless otherwise specified, terms such as "first" and "second" are used only to distinguish components from each other, and do not represent a specific order or sequence.

[0010] Fig. 1 is a perspective view showing a three-dimensional structure 1 in one embodiment of the present invention, and Fig. 2 is an exploded perspective view. As shown in Fig. 1 and Fig. 2, the three-dimensional structure 1 includes a substantially flat base member 2 (first member) and a lid member 3 (second member) that is rotatably provided with respect to the base member 2. The base member 2 and the lid member 3 are manufactured by an additive manufacturing method using a 3D printer, as described below.

[0011] As shown in FIG. 2, the lid member 3 has a flat lid body 30, a hook portion 31 formed on the edge of the lid body 30, and two connecting portions 32 (32A, 32B) connected to the base member 2. Each connecting portion 32 includes a base portion 33 extending in the +X direction from the lid body 30, and shaft portions 34A, 34B extending in the Y direction (axial direction) from the base portion 33. In this embodiment, the shaft portions 34A, 34B are arranged on both sides of the base portion 33 in the Y direction, but the shaft portions may be arranged only on the +Y direction side or the -Y direction side of the base portion 33. In addition, the lid member 3 of this embodiment includes two connecting portions 32, but the number of connecting portions 32 is not limited to this as long as the lid member 3 is rotatably connected to the base member 2. For example, the lid member 3 may include only one connecting portion 32.

[0012] The base member 2 includes a plate portion 20 extending along the XY plane, a wall 21 extending in the +Z direction from the plate portion 20, an engagement portion 22 with which the hook portion 31 of the cover member 3 can be engaged, and bearing portions 23A, 23B that respectively receive the shaft portions 34A, 34B of the connecting portion 32 of the cover member 3. An accommodation space 24 for accommodating, for example, a battery is formed inside the wall 21, and an opening 25 communicating with the accommodation space 24 is formed in the plate portion 20. The opening 25 has a shape that generally corresponds to the outer shape of the cover body 30 of the cover member 3, and when the cover member 3 is in the closed state (the state shown in FIG. 1), the cover body 30 of the cover member 3 is positioned inside the opening 25 of the base member 2.

[0013] 1, for example, when a battery is accommodated in the accommodation space 24, the cover member 3 can be rotated about the Y axis relative to the base member 2 to access and replace the battery in the accommodation space 24 from the -Z direction side through the opening 25. However, the present invention is not limited to such a structure, and can be applied to any three-dimensional structure that includes a shaft portion and a bearing portion that receives the shaft portion.

[0014] Fig. 3A is a cross-sectional view of the base member 2, and Fig. 3B is an enlarged view of a part of the cross section of line AA in Fig. 3A. As shown in Figs. 3A and 3B, a shaft hole 26 extending cylindrically in the Y direction is formed in each of the bearing parts 23A and 23B of the base member 2, and the shaft part 34A or 34B of the connecting part 32 of the cover member 3 is disposed in a space S formed inside the shaft hole 26. That is, the inner peripheral surface 26A (see Fig. 3B) of the shaft hole 26 serves as a bearing surface for receiving the shaft part 34A or 34B of the connecting part 32 of the cover member 3. As shown in Fig. 3A, a space 27 for accommodating the base part 33 of the connecting part 32 of the cover member 3 is formed between the bearing part 23A and the bearing part 23B.

[0015] 3A and 3B, a communication passage 28B is formed in the bearing portion 23B, which extends from the shaft hole 26 in the -Y direction and opens at the surface 20A (see FIGS. 1 and 2) of the plate portion 20. Similarly, a communication passage 28A is formed in the bearing portion 23A, which extends from the shaft hole 26 in the +Y direction and opens at the surface 20A of the plate portion 20. These communication passages 28A, 28B connect the interior of the shaft hole 26, i.e., the internal space S formed radially inward of the inner circumferential surface 26A of the shaft hole 26, to the outside of the bearing portions 23A, 23B.

[0016] Fig. 4A is an enlarged perspective view of the connecting portion 32 of the cover member 3, Fig. 4B is a front view of the connecting portion 32 shown in Fig. 4A, and Fig. 4C is a plan view. As shown in Figs. 4A to 4C, each of the shaft portions 34A and 34B of the connecting portion 32 includes a core portion 40 and a plurality of protruding portions 41 protruding radially outward from the core portion 40 at predetermined intervals in the circumferential direction. Each of the shaft portions 34A and 34B in this embodiment includes six protruding portions 41 arranged at equal intervals along the circumferential direction, but the number of protruding portions 41 is not limited to that shown in the figure, and these protruding portions 41 do not have to be arranged at equal intervals along the circumferential direction.

[0017] As shown in Figures 4A to 4C, each protrusion 41 has a top surface 42 facing radially outward and side surfaces 43 extending from both circumferential edges of the top surface 42. Also, as shown in Figure 4C, each of the protrusions 41 having the top surface 42 and the side surfaces 43 is formed so that its circumferential position changes along the Y direction (axial direction). In this embodiment, each of the protrusions 41 is formed in a spiral shape so as to rotate clockwise as it approaches the -Y direction.

[0018] 4A to 4C, the outer peripheral surface 44 of the core portion 40 is located between the side surfaces 43 of adjacent protrusions 41. In each of the shaft portions 34A, 34B, the top surface 42 of the protrusion 41 is located at the outermost radial position, and the outer peripheral surface 44 of the core portion 40 is located at the innermost radial position, and the top surface 42 and the outer peripheral surface 44 are connected by the side surface 43. In this manner, one side surface 43 of the protrusion 41, one side surface 43 of the adjacent protrusion 41, and the outer peripheral surface 44 of the core portion 40 form a connection portion 45 that connects the top surfaces 42 of adjacent protrusions 41 in the circumferential direction.

[0019] 5 is an enlarged cross-sectional view showing the vicinity of the shaft portion 34A of the connecting portion 32 and the bearing portion 23A. As shown in FIG. 5, the shaft portion 34A of the connecting portion 32 is located inside the shaft hole 26 of the bearing portion 23A, and the top surface 42 of the protruding portion 41 of the shaft portion 34A faces the inner peripheral surface 26A of the shaft hole 26 at a position radially away from the inner peripheral surface 26A (bearing surface) of the shaft hole 26 by a small distance (hereinafter referred to as the minimum distance D). As described above, in the shaft portion 34A, the top surface 42 of the protruding portion 41 is located at the outermost position in the radial direction, so that any part of the connecting portion 45 connecting the top surfaces 42 of the adjacent protruding portions 41 (the side surface 43 of the protruding portion 41 and the outer peripheral surface 44 of the core portion 40) is located at a distance greater than the minimum distance D from the inner peripheral surface 26A of the shaft hole 26.

[0020] With this configuration, compared to when the shaft portion 34A is a cylindrical shaft, that is, compared to when the shaft portion 34A faces the inner peripheral surface 26A of the shaft hole 26 at the minimum distance D over the entire circumference, the area of ​​the shaft portion 34A facing the inner peripheral surface 26A of the shaft hole 26 of the bearing portion 23A at the minimum distance D is smaller, so that adhesion between the inner peripheral surface 26A of the shaft hole 26 of the bearing portion 23A and the shaft portion 34A is suppressed when forming the base member 2 and the cover member 3 as described below. The same can be said about the shaft portion 34B and the bearing portion 23B. In this way, adhesion is unlikely to occur between the inner peripheral surface 26A of the shaft hole 26 of the bearing portions 23A and the shaft portions 34A and 34B, so that the distance between the inner peripheral surface 26A of the bearing portions 23A and the top surface 42 of the shaft portions 34A and 34B can be shortened compared to when the shaft portions 34A and 34B are cylindrical shafts. This reduces the gap between the inner peripheral surface 26A of the bearings 23A, 23B and the top surface 42 of the shaft portions 34A, 34B, thereby reducing rattling that occurs when the shaft portions 34A, 34B rotate relative to the bearings 23A, 23B. As a result, the bearing structure consisting of the shaft portions 34A, 34B and the bearings 23A, 23B becomes compact.

[0021] Next, a method for manufacturing the above-mentioned three-dimensional structure 1 will be described with reference to Figures 6A and 6B. The above-mentioned three-dimensional structure 1 is manufactured by stacking materials in the Y direction (stacking direction) using a 3D printer (additive manufacturing method). An example of stacking materials in the -Y direction will be described below, but the above-mentioned three-dimensional structure 1 can also be manufactured by stacking materials in the +Y direction.

[0022] Specifically, the method for manufacturing the three-dimensional structure 1 includes an additive manufacturing process S1 in which material layers are stacked in the -Y direction (stacking direction) to form the above-mentioned base member 2 (first member) and lid member 3 (second member), as shown in Figure 6A, and a rotation process S2 in which the shaft portions 34A, 34B of the lid member 3 formed by the additive manufacturing process S1 are rotated relative to the bearing portions 23A, 23B of the base member 2.

[0023] In the additive manufacturing process S1, the base member 2 and the lid member 3 are manufactured by an additive manufacturing method using a 3D printer. The type of additive manufacturing method is not particularly limited, and examples of the additive manufacturing method include a material extrusion method in which a molten material is extruded from a nozzle and laminated, a photolithography method in which a photocurable resin is irradiated with a laser and laminated, a material jetting method in which a material jetted from a head is hardened with ultraviolet light and laminated, a binder jetting method in which a binder is jetted from a nozzle onto a material powder and solidified to laminate, and a powder bed fusion method in which a material powder is irradiated with a laser and sintered to laminate. In addition, the material used for additive manufacturing is not limited to a specific one, and various materials such as resin, metal, ceramic, and gypsum can be used. Furthermore, the material layer (first material layer) constituting the base member 2 and the material layer (second material layer) constituting the lid member 3 may be the same material or different materials.

[0024] In the additive manufacturing process S1, a material layer (first material layer) constituting the base member 2 and a material layer (second material layer) constituting the lid member 3 are stacked one by one in the -Y direction on a stage of a 3D printer by additive manufacturing. In this way, each part of the base member 2 and the lid member 3 is formed, but the following description will focus on the formation of the shaft parts 34A, 34B of the connecting part 32A (see FIG. 2) located on the -Y direction side of the lid member 3 and the bearing parts 23A, 23B corresponding to these. In the additive manufacturing process S1, a support material (not shown) may be stacked together with the first material layer and the second material layer as necessary.

[0025] Fig. 6B is a flow chart showing a part of the additive manufacturing process S1. As shown in Fig. 6B, the additive manufacturing process S1 includes a passage forming process S11 for forming the communication passage 28A located furthest on the +Y direction side of the four communication passages 28A, 28B of the base member 2, a shaft structure forming process S12 for forming the shaft portion 34A and the bearing portion 23A of the connecting portion 32A, a base portion forming process S13 for forming the base portion 33 of the connecting portion 32A and the corresponding portion of the base member 2, a shaft structure forming process S14 for forming the shaft portion 34B and the bearing portion 23B of the connecting portion 32A, and a passage forming process S15 for forming the communication passage 28B.

[0026] In the passage forming process S11, a (first) material layer is laminated so as to form a communication passage 28A in the bearing portion 23A. This communication passage 28A connects the internal space S formed radially inward of the inner circumferential surface 26A of the shaft hole 26 of the bearing portion 23A to the outside of the bearing portion 23A. Similarly, in the passage forming process S15, a (first) material layer is formed so as to form a communication passage 28B in the bearing portion 23B. This communication passage 28B connects the internal space S formed radially inward of the inner circumferential surface 26A of the shaft hole 26 of the bearing portion 23B to the outside of the bearing portion 23B.

[0027] In the shaft structure forming process S12, the shaft portion 34A and the bearing portion 23A of the connecting portion 32A are formed by repeating in the -Y direction a continuous layer forming process S121 in which a (first) material layer constituting the bearing portion 23A and a (second) material layer constituting the shaft portion 34A are continuously formed on the same lamination plane. Similarly, in the shaft structure forming process S14, the shaft portion 34B and the bearing portion 23B of the connecting portion 32A are formed by repeating in the -Y direction a continuous layer forming process S141 in which a (first) material layer constituting the bearing portion 23B and a (second) material layer constituting the shaft portion 34B are continuously formed on the same lamination plane.

[0028] In the base forming process S13, the process of continuously forming the (first) material layer constituting the base member 2 and the (second) material layer constituting the base 33 of the connecting portion 32A on the same stacking plane is repeated in the -Y direction to form the base 33 of the connecting portion 32A and a part of the base member 2.

[0029] 6B, the shaft portions 34A and 34B of the connecting portion 32A and the corresponding bearing portions 23A and 23B can be formed. The shaft portions 34A and 34B of the connecting portion 32B and the corresponding bearing portions 23A and 23B can be formed by a similar process.

[0030] After the shaping of the base member 2 and the lid member 3 is completed by the additive manufacturing process S1, the support material is removed by an appropriate method as necessary. In addition, uncured material may remain in the gaps between the members after shaping, and in this embodiment, a rotation process S2 is performed to remove such support material and excess material (hereinafter referred to as "unwanted material"). In this rotation process S2, the shaft parts 34A and 34B of the lid member 3 are rotated relative to the bearing parts 23A and 23B of the base member 2. By such a rotation process, the unwanted material existing between the inner circumferential surface 26A of the shaft hole 26 of the bearing parts 23A and 23B and the shaft parts 34A and 34B can be collected at the connection part 45 between the adjacent protrusions 41, making it easy to remove the unwanted material.

[0031] In particular, in this embodiment, since the protruding portion 41 of the shaft portions 34A, 34B is formed in a spiral shape as described above, when the shaft portions 34A, 34B are rotated in the rotation process, the unwanted matter collected at the connection portion 45 of the shaft portions 34A, 34B hits the protruding portion 41 and is scraped out in the axial direction (Y direction) along the connection portion 45. This makes it even easier to remove the unwanted matter.

[0032] Furthermore, in this embodiment, the passage forming processes S11 and S15 can form connecting passages 28A and 28B in the respective bearing portions 23A and 23B, so that by rotating the shaft portions 34A and 34B, the waste material scraped out in the axial direction along the connection portion 45 of the shaft portions 34A and 34B as described above can be discharged from the internal space S (see Figures 3A and 3B) formed radially inward of the inner surface 26A of the shaft hole 26 to the surface 20A of the plate portion 20 of the base member 2 through the connecting passages 28A and 28B.

[0033] As described above, according to this embodiment, only the top surfaces 42 of the shaft portions 34A, 34B face the inner circumferential surface 26A (bearing surface) of the axial hole 26 of the bearing portions 23A, 23B near the inner circumferential surface 26A, and the area of ​​the shaft portions 34A, 34B facing the inner circumferential surface 26A near the inner circumferential surface 26A is smaller than when the shaft portions 34A, 34B are cylindrical shafts. Therefore, when the shaft portions 34A, 34B and the bearing portions 23A, 23B are additively manufactured, adhesion is suppressed between the inner circumferential surface 26A of the axial hole 26 of the bearing portions 23A, 23B and the shaft portions 34A, 34B. In this way, adhesion is unlikely to occur between the inner circumferential surface 26A of the shaft hole 26 of the bearing parts 23A, 23B and the shaft parts 34A, 34B, so the distance between the inner circumferential surface 26A of the bearing parts 23A, 23B and the top surface 42 of the shaft parts 34A, 34B can be made shorter than when the shaft parts 34A, 34B are cylindrical shafts. This reduces the gap between the inner circumferential surface 26A of the bearing parts 23A, 23B and the top surface 42 of the shaft parts 34A, 34B, so that rattles that occur when the shaft parts 34A, 34B rotate relative to the bearing parts 23A, 23B can be reduced. In other words, a three-dimensional structure including the shaft parts 34A, 34B and the bearing parts 23A, 23B with little rattle can be easily manufactured by additive manufacturing. In addition, such shaft parts 34A, 34B can be manufactured by additive manufacturing without using a support material.

[0034] In the above embodiment, the spirally formed protrusion 41 is used to scrape out unnecessary materials, but it is also possible to configure such protrusion 41 to mesh with another member and use it as a gear. In addition, for example, lubricating oil or grease may be injected into the spiral groove formed between adjacent protrusions 41. In a structure in which two members are integrally laminated, there is a problem that lubricating liquid or grease does not easily spread over the sliding surface, but in a three-dimensional structure manufactured by the above process, lubricating oil or grease is easily spread between the bearing parts 23A, 23B and the shaft parts 34A, 34B. That is, by introducing lubricating oil or grease into the groove between the adjacent protrusions 41 from the above-mentioned communication passages 28A, 28B and rotating the shaft parts 34A, 34B in the opposite direction to the above, the lubricating oil or grease introduced from the communication passages 28A, 28B can be guided to the back along the axial direction by the spirally formed protrusion 41.

[0035] The base member 2 and the cover member 3 illustrated in the above-described embodiment are merely examples, and the shapes and functions of the first member and the second member constituting the three-dimensional structure of the present invention are not limited to those described above.

[0036] As described above, the three-dimensional structure according to the present invention can adopt the following configurations. [Configuration 1] A first member including a bearing portion having a bearing surface; a second member including a shaft portion extending along the axial direction and rotatably connected to the bearing portion; Equipped with The shaft portion of the second member is a plurality of apex surfaces arranged along a circumferential direction, the apex surfaces facing the bearing surface at positions spaced a predetermined radial distance from the bearing surface of the bearing portion; a plurality of connection portions that connect adjacent top surfaces among the plurality of top surfaces in the circumferential direction, the connection portions being located at positions radially farther from the bearing surface of the bearing portion than the plurality of top surfaces; having 3D structure.

[0037] [Configuration 2] In the above configuration 1, A three-dimensional structure, wherein the circumferential position of each of the multiple top surfaces of the shaft portion of the second member varies along the axial direction.

[0038] [Configuration 3] In the above configuration 1 or 2, A three-dimensional structure, wherein the bearing portion of the first member has a communication passage formed therein that connects an internal space formed radially inward of the bearing surface to the outside of the bearing portion.

[0039] Moreover, the method for producing a three-dimensional structure according to the present invention can employ the following configuration. [Configuration 4] A method for manufacturing a three-dimensional structure including a first member including a bearing portion having a bearing surface, and a second member including a shaft portion extending along an axial direction and rotatably connected to the bearing portion, comprising: An additive manufacturing process includes stacking a first material layer and a second material layer in a stacking direction to form the first member made of the first material layer and the second member made of the second material layer, The additive manufacturing process includes a shaft structure manufacturing process for forming the bearing portion and the shaft portion by repeating a continuous layer forming process in which the first material layer and the second material layer are continuously formed on the same stacking plane in the stacking direction, In the shaft structure forming process, the first material layer forms the bearing surface of the bearing portion; The second material layer forms a plurality of top surfaces arranged along a circumferential direction, the top surfaces facing the bearing surface at a position radially spaced a predetermined distance from the bearing surface of the bearing part, and a plurality of connection portions connecting adjacent top surfaces among the plurality of top surfaces in the circumferential direction, the connection portions being located radially farther from the bearing surface of the bearing part than the plurality of top surfaces. method.

[0040] [Configuration 5] In the above configuration 4, A method for manufacturing a three-dimensional structure, further comprising, after the additive manufacturing step, a rotation step of rotating the shaft portion of the second member relative to the bearing portion of the first member.

[0041] [Configuration 6] In the above configuration 4 or 5, A method for manufacturing a three-dimensional structure, in which, in the shaft structure forming process, the continuous layer forming process is repeated in the stacking direction so that the circumferential positions of the multiple top surfaces and the multiple connection portions of the shaft portion change along the stacking direction.

[0042] [Configuration 7] In any one of the above configurations 4 to 6, The additive manufacturing process further includes a passage forming process of laminating the first material layer before or after the shaft structure forming process so that a communication passage connecting an internal space formed radially inside the bearing surface of the bearing portion to the outside of the bearing portion is formed in the bearing portion. A method for manufacturing three-dimensional structures.

[0043] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-described embodiments and may be embodied in various different forms within the scope of the technical concept thereof. [Explanation of symbols]

[0044] 1 3D structure 2 Base member (first member) 3 Lid member (second member) 20 Board part 23A,23B Bearing part 26 Shaft hole 26A Inner surface (bearing surface) 28A, 28B connecting passage 30 Lid body 32 Connecting part 33 Base 34A,34B Shaft part 40 Core 41 Protrusion 42 Top surface 43 Side surface 44 Outer peripheral surface 45 Connection part S Internal space

Claims

1. A first member including a bearing portion having a bearing surface; a second member including a shaft portion extending along the axial direction and rotatably connected to the bearing portion; Equipped with The shaft portion of the second member is a plurality of apex surfaces arranged along a circumferential direction, the apex surfaces facing the bearing surface at positions spaced a predetermined radial distance from the bearing surface of the bearing portion; a plurality of connection portions that connect adjacent top surfaces among the plurality of top surfaces in the circumferential direction, the connection portions being located at positions radially farther from the bearing surface of the bearing portion than the plurality of top surfaces; having 3D structure.

2. The three-dimensional structure according to claim 1 , wherein the positions in the circumferential direction of each of the plurality of top surfaces of the shaft portion of the second member vary along the axial direction.

3. 3. The three-dimensional structure according to claim 1, wherein the bearing portion of the first member has a communication passage formed therein, the communication passage connecting an internal space formed radially inward of the bearing surface to an outside of the bearing portion.

4. A method for manufacturing a three-dimensional structure including a first member including a bearing portion having a bearing surface, and a second member including a shaft portion extending along an axial direction and rotatably connected to the bearing portion, comprising: The method includes an additive manufacturing process of stacking a first material layer and a second material layer in a stacking direction to form the first member made of the first material layer and the second member made of the second material layer, The additive manufacturing process includes a shaft structure manufacturing process for forming the bearing portion and the shaft portion by repeating a continuous layer forming process in which the first material layer and the second material layer are continuously formed on the same stacking plane in the stacking direction, In the shaft structure forming process, the first material layer forms the bearing surface of the bearing portion; the second material layer forms a plurality of top surfaces arranged along a circumferential direction, the plurality of top surfaces facing the bearing surface at a position radially spaced a predetermined distance from the bearing surface of the bearing part, and a plurality of connection portions connecting adjacent top surfaces among the plurality of top surfaces in the circumferential direction, the plurality of connection portions being located radially farther from the bearing surface of the bearing part than the plurality of top surfaces; method.

5. The method for manufacturing a three-dimensional structure according to claim 4 , further comprising, after the additive manufacturing step, a rotating step of rotating the shaft portion of the second member relative to the bearing portion of the first member.

6. The method for manufacturing a three-dimensional structure according to claim 4 or 5, wherein in the shaft structure forming process, the continuous layer forming process is repeated in the stacking direction so that the positions of the multiple top surfaces and the multiple connection portions of the shaft portion in the circumferential direction change along the stacking direction.

7. The additive manufacturing process further includes a passage forming process of laminating the first material layer before or after the shaft structure forming process so that a communication passage connecting an internal space formed radially inside the bearing surface of the bearing portion to the outside of the bearing portion is formed in the bearing portion. The method for producing a three-dimensional structure according to claim 6 .

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