Laminated structure and method for manufacturing laminated structure

Abstract

To improve the anisotropy of strength in layered structures manufactured by layering materials using 3D printing, thereby increasing the overall strength and controlling the strength of the structure. [Solution] By forming a laminated structure 401 in close contact with the outside of a laminated structure 201, which has a structure in which a single bead is stacked in a continuous, seamless shape, for example, in a spiral shape, the anisotropy of the beads is reduced and a laminated structure with higher strength is provided.

Description

Technical Field

[0001] The present invention relates to a laminated structure and a method for manufacturing a laminated structure, and more specifically, to a laminated structure manufactured by laminating a modeling material by 3D printing and a method for manufacturing a laminated structure.

Background Art

[0002] Among various printing methods of 3D printing, the MEX (Material Extrusion) method is a modeling method that melts a material such as a thermoplastic resin and forms a three-dimensional structure while extruding and laminating it from a nozzle. Although it has advantages such as being able to form a fine expression with resin and a large curved surface shape, it has a problem of "anisotropy" that the strength is different in the laminated direction and other directions. That is, although the strength can be ensured against a force in a predetermined direction, there is a problem that sufficient strength cannot be ensured against a direction different from the predetermined direction (for example, a direction perpendicular to the predetermined direction), and a method for improving such anisotropy has been proposed.

[0003] For example, a method for manufacturing an object by a computer-controlled device according to computer instructions obtained from a computer model of the object, including manufacturing a plurality of bead materials, whereby at least a part of two beads is in contact and arranged at an angle between 1 and 179 degrees with respect to each other, manufacturing the two beads on respective ones of conceptual planes that intersect each other, and manufacturing the two beads so as to form respective conceptual non-planar layers has been proposed (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the conventional method for manufacturing the object disclosed in Patent Document 1 reduces delamination by stacking multiple beads at an angle. However, because multiple beads are used, it is necessary to stop the material discharge each time a bead is stacked. Furthermore, when adding reinforcing materials such as fibers, it is not possible to incorporate a continuous fiber, which makes it difficult to further increase the strength.

[0006] In view of the above issues, the present invention aims to provide a laminated structure and a method for manufacturing a laminated structure that improves anisotropy in a laminated structure or controls the strength that differs depending on the direction, by combining a structure in which a single bead is laminated with a structure with a different lamination direction, thereby enabling efficient fabrication. [Means for solving the problem]

[0007] The invention described in claim 1 is a laminated structure comprising: a first structure in which a single bead adjacent to a plurality of locations is laminated such that the longitudinal direction of the adjacent portions is in a predetermined direction; and a second structure in close contact with the first structure in which a single bead is laminated such that the longitudinal direction of the adjacent portions is in a direction different from the predetermined direction.

[0008] The invention described in claim 2 is characterized in that, in the laminated structure described in claim 1, a single bead is laminated in a single continuous line.

[0009] The invention described in claim 3 is characterized in that, in the laminated structure described in claim 2, the first structure or the second structure is made up of a single bead laid in a spiral manner.

[0010] The invention described in claim 4 is characterized in that, in the laminated structure described in claim 2, the first structure or the second structure is formed by closely adhering multiple layers formed by laminating single beads.

[0011] The invention described in claim 5 is characterized in that, in the laminated structure described in claim 1, a single bead contains a single fiber connected from both ends.

[0012] The invention described in claim 6 is characterized in that, in the laminated structure described in claim 1, the second structure is in close contact with the entire first structure.

[0013] The invention described in claim 7 is characterized in that, in the laminated structure described in claim 1, the second structure is in close contact with a part of the first structure.

[0014] The invention described in claim 8 is characterized in that, in the laminated structure described in claim 1, the second structure is in close contact with the outside of the first structure.

[0015] The invention described in claim 9 is a method for fabricating a three-dimensional layered structure by obtaining the necessary toolpaths from three-dimensional shape data, comprising: a toolpath calculation step of calculating a toolpath formed by stacking adjacent single beads at multiple locations; a first forming step of forming a first structure by stacking single beads based on the calculated toolpath such that the longitudinal direction of adjacent parts is in a predetermined direction; and a second forming step of forming a second structure by stacking single beads in close contact with the first structure such that the longitudinal direction of adjacent parts is in a direction different from the predetermined direction, based on the calculated toolpath.

[0016] The invention described in claim 10 is characterized in that, in the method for fabricating a laminated structure described in claim 9, the first structure or the second structure is fabricated by closely adhering multiple layers, each of which a single bead is laminated.

[0017] The invention described in claim 11 is characterized in that, in the method for fabricating a laminated structure described in claim 10, the toolpath direction of the odd-numbered layers, including the bottom layer, and the even-numbered layers, including the layer following the bottom layer, are opposite. [Effects of the Invention]

[0018] According to the present invention, there are provided a first structure in which a single bead adjacent at a plurality of locations is laminated such that the longitudinal direction of the adjacent portions is in a predetermined direction, and a second structure that is in close contact with the first structure and in which a single bead is laminated such that the longitudinal direction of the adjacent portions is in a direction different from the predetermined direction. Therefore, it is possible to improve the anisotropy of strength in the laminated structure, increase the overall strength, and control the strength of the structure.

Brief Description of the Drawings

[0019] [Figure 1] It is a diagram for explaining a laminated structure used in an embodiment of the present invention. [Figure 2] It is a diagram showing an example of the first layer of a laminated structure according to an embodiment of the present invention. [Figure 3] It is a diagram showing a partially enlarged portion of an example of the first layer of a laminated structure according to an embodiment of the present invention. [Figure 4] It is a diagram showing an example of the second layer of a laminated structure according to an embodiment of the present invention. [Figure 5] It is a flowchart showing a manufacturing method of a laminated structure according to an embodiment of the present invention. [Figure 6] It is a diagram for explaining an example of a shaping method of the first layer by a manufacturing apparatus of a laminated structure according to an embodiment of the present invention. [Figure 7] It is a diagram for explaining an example of a shaping method of the second layer by a manufacturing apparatus of a laminated structure according to an embodiment of the present invention. [Figure 8] It is a diagram showing another example of the second layer of a laminated structure according to an embodiment of the present invention. [Figure 9] It is a diagram showing an example of a lamination mode of a laminated structure according to an embodiment of the present invention. [Figure 10] It is a diagram showing another example of a lamination mode of a laminated structure according to an embodiment of the present invention. [Figure 11] It is a diagram showing another example of a lamination mode of a laminated structure according to an embodiment of the present invention. [Figure 12]This figure shows another example of a lamination mode for a laminated structure according to one embodiment of the present invention. [Figure 13] This figure shows another example of a laminated structure according to one embodiment of the present invention. [Figure 14] This figure shows another example of a laminated structure according to one embodiment of the present invention. [Figure 15] This figure shows an example of a structure in which the outer laminated structure of one embodiment of the present invention covers only a portion of the inner laminated structure. [Modes for carrying out the invention]

[0020] Hereinafter, embodiments of the laminated structure and manufacturing method of the laminated structure of the present invention will be described with reference to the drawings. Note that even in different drawings, the same reference numerals will be used when indicating the same process or configuration. (Principle of the present invention) Conventional material extrusion methods (MEX) create structures by melting and extruding thermoplastic resins and solidifying them in layers. While this method ensures strength against forces in a predetermined direction, such as the layering direction, it has the problem of not being able to ensure sufficient strength in directions other than the predetermined direction (for example, directions perpendicular to the predetermined direction or directions that shear the layered structure). This anisotropy of strength leads to problems where structures formed by MEX cannot be used for certain purposes, such as resin pipes, handrails, or chair leg pipes, due to insufficient strength. In view of these problems, the inventors have obtained knowledge of a layered structure that has strength in all directions or in specific directions by utilizing this anisotropy in reverse. That is, while the strength is high in the layering direction, the strength is low in directions perpendicular to the layering direction, such as the longitudinal direction of the beads formed by the layering of extruded materials. By forming a layer with a different longitudinal direction, such as perpendicular, on the outside of a structure formed by beads with a predetermined longitudinal direction, it was possible to increase the strength in a specific direction or increase the overall strength through the mutual anisotropy of strength. This invention controls the strength of a structure by overlapping and laminating beads in directions that differ in their longitudinal orientation, regardless of the shape of the structure being formed. (Reinforced structure of the first embodiment) Figure 1 is a diagram illustrating a laminated structure used in one embodiment of the present invention. Figure 2 is a diagram showing an example of the first layer of the laminated structure of one embodiment of the present invention, and Figure 3 is a diagram showing a magnified portion of the example of the first layer. Figure 4 is a diagram showing an example of the second layer of the laminated structure of one embodiment of the present invention. In this embodiment, as an example of the present invention, we target a structure that can be used as a cylinder 101 or a hollow tube as shown in Figure 1. Such a tube can be manufactured as a laminated structure 201 as shown in Figure 2 using a 3D printer or the like. The laminated structure 201 can be formed by laminating material from the bottom 202 to the top 203, as is known in the art. The structure 201 formed in this way has a structure in which annular beads 204 are stacked in the lamination direction 205, and as shown in magnified Figure 3, at least in adjacent parts 207, the contact portion 303 of adjacent bead portions 301 and 302 is in a predetermined longitudinal direction 206. Generally, a structure formed in this way has high strength in the lamination direction, but low strength in the longitudinal direction 206 of the beads.

[0021] Here, the laminated structure 201 has a structure in which beads 204 are laminated as described above, but the beads in this embodiment are laminated as a single continuous bead without any breaks, for example, a one-stroke structure. Having such a structure generally allows for continuous molding without stopping the extrusion of material, so material and energy can be used efficiently, and reinforcing members such as fibers can be inserted in a continuous form, that is, one or more continuous fibers can be inserted throughout, further increasing the strength.

[0022] In this embodiment, with respect to the basic structure described above, as shown in Figure 4, a laminated structure 401 is formed by closely attaching a bead 402 to the outside of the laminated structure 201 so that the longitudinal direction of the beads is different, thereby reducing the anisotropy of strength and providing a laminated structure with higher strength. In Figure 4, the outer laminated structure 401 is partially removed for illustrative purposes, but in reality, it can be formed to surround the entire laminated structure 201, or it can cover any part to achieve the strength required for the final product. Furthermore, although the laminated structure 401 shown in Figure 4 is depicted with the longitudinal direction of the bead 402 perpendicular to the longitudinal direction of the laminated structure 201, it is not limited to this and can be any angle as long as the strength requirements are met. In addition, although the laminated structure 401 is depicted as one layer in Figure 4, it can be made by laminating two or more layers. (Method of manufacturing a laminated structure) A method for manufacturing a laminated structure having a reinforced structure according to the first embodiment will be described using the cylindrical laminated structures 201 and 401 shown in Figure 4 as an example. Figure 5 is a flowchart illustrating a method for manufacturing a laminated structure according to one embodiment of the present invention. Figure 6 is a diagram illustrating an example of a method for fabricating the first layer using a manufacturing apparatus for a laminated structure according to one embodiment of the present invention, and Figure 7 is a diagram illustrating an example of a method for fabricating the second layer. In this embodiment, a 3D printer using a robotic arm as conceptually shown in Figures 6 and 7 is used as the manufacturing apparatus, but it is not limited to this, and a normal 3D printer can be used, and a support stand or the like can be prepared as appropriate for manufacturing. In addition, the present invention can be applied to all apparatuses that extrude material to form structures. Furthermore, any technology known in the art can be used for 3D data, data conversion methods, and 3D printer control methods required when fabricating with a 3D printer.

[0023] First, 3D shape data of the three-dimensional object to be manufactured is acquired (step S501), and a toolpath is calculated from the 3D shape data to form a layered structure in a single stroke (step S502). Based on the calculated toolpath, as shown in Figure 6, material is first extruded from the extrusion unit 601 in a single stroke and layered upwards on the support base 602 to form the inner layered structure 201 (step S503). As a result, the longitudinal direction of the formed bead is horizontal. Next, as shown in Figure 7, the support base 602 is inverted by the robot arm 701, and based on the calculated toolpath, the outer layered structure 401 is formed by layering so that the longitudinal direction is different, so as to enclose the inner layered structure 201 (step S504).

[0024] With the above manufacturing method, a laminated structure having anisotropy in strength in a different direction from the inner laminated structure is laminated on the outside. As a result, they complement each other, mitigating anisotropy or increasing strength in a specific direction, thereby controlling the strength that varies depending on the orientation of the structure.

[0025] Furthermore, although the inner laminated structure 201 was formed by drawing a bead in a single stroke as described above, the outer laminated structure 401 can also be fabricated in a single stroke. That is, as shown in Figure 8, by stacking materials in a single stroke, a laminated structure 801 having a structure like the bead 802 can be created. This allows for efficient use of materials and energy, similar to the laminated structure 201, and also enables the implementation of reinforcing members such as fibers in a continuous form, for example, by continuously inserting a single fiber from the start point to the end of the stacking, thereby further increasing strength. The embodiment has been described using a cylindrical structure as an example, but the shape that can be formed is not limited to this, and the present invention can be applied to any 3D shape, including cubes, rectangular prisms, and cones. (A method for laminating seamless beads) In the description of the first embodiment above, the laminated structure 201 was formed by laminating in a single continuous line. That is, as shown in Figure 9, a laminated structure having a continuous, seamless bead was obtained by extruding the material and laminating it in a spiral shape from the bottom to the top (upward) (lamination mode). However, it is also possible to obtain a laminated structure having a similar structure using lamination modes other than single continuous line, and such an example will be described with reference to Figure 10. Figure 10 is a diagram showing another example of a lamination mode for a laminated structure according to one embodiment of the present invention. (An example of folded stacking mode) The lamination method shown in Figure 10 involves laminating the rings that form the laminated structure 1001 in a fixed direction (clockwise or counterclockwise) starting from the lamination start position 1002. After laminating the first ring 1003 all the way around, the structure folds back and the second ring 1004 is laminated in the opposite direction (counterclockwise or clockwise). As a result, the beads of the formed laminated structure have opposite lamination directions (toolpath directions) for each layer. That is, the odd-numbered layers and even-numbered layers have opposite toolpath directions for the beads forming the layers, and the lamination end point of each ring in each layer becomes the starting point of the lamination of the next (upper) ring, resulting in a folded structure. In this way, by using a folded lamination mode other than single-stroke lamination, a laminated structure with a continuous, seamless bead can be obtained. (Another example of the folded stacking mode) In the cylindrical example described above, a hollow pipe was manufactured, but it is also possible to manufacture cylinders with a solid interior or cylinders with thick walls. Figure 11 shows another example of the lamination mode of a laminated structure according to one embodiment of the present invention, and Figure 12 shows yet another example of the lamination mode. As shown in Figure 11, material can be extruded from the circumference or center and laminated in a spiral pattern to form a disc-shaped layer 1101. Such layers can be continued from the center or periphery, with the second layer 1201 being added consecutively from the first layer 1101, and this process can be repeated. In other words, by laminating on each disc forming the cylinder so that the direction of rotation of the spirals is the same, a solid cylinder can be manufactured in a single continuous line.

[0026] Furthermore, as shown in Figure 13, a laminated structure with a continuous, seamless bead can be obtained by stacking the first layer of disks 1302 in a spiral pattern (with the spiral rotation direction clockwise or counterclockwise), and then stacking the second layer of disks 1303 with the toolpath in the opposite direction (with the spiral rotation direction counterclockwise or clockwise), as shown in Figure 13. As a result of this fabrication, it becomes possible to obtain a laminated structure 1301, as shown in Figure 13, in which the toolpath direction for the beads forming the layers is reversed between odd-numbered layers and even-numbered layers, starting from the bottom layer which is the base. In this laminated structure, when stacking of a disk in a certain layer starts from the center, once it reaches a predetermined position on the circumference, it starts stacking as the starting point for stacking the next (upper) layer of disks.

[0027] Furthermore, with reference to Figure 14, the manufacturing of a cylinder with thick walls will be described. Figure 14 shows another example of a lamination mode for a laminated structure according to one embodiment of the present invention. As shown in Figure 14, material can be extruded from the circumferential portion 1402 or the inner portion 1403 and laminated in a spiral manner to form an annular layer 1401. By laminating such layers from the inner portion 1403 or the peripheral portion 1402, continuing from the first layer 1401, and repeating this process, a thick cylinder with a continuous, seamless bead can be manufactured. The thick cylinder of this structure can also be laminated with the spiral rotation in the same direction. In addition, such a folded lamination mode can also be used when manufacturing the outer laminated structure.

[0028] In this embodiment, by employing a lamination method such as drawing in a single stroke, a laminated structure having a continuous, unbroken bead is used as the basis. By combining structures with different longitudinal directions of the bead, the anisotropy of strength can be improved, resulting in overall high strength or controllable strength. (Second Embodiment) The laminated structure shown in the first embodiment described above is characterized by having a laminated structure with beads of different longitudinal directions arranged on the entire outer surface of the inner laminated structure. However, in this embodiment, the outer laminated structure covers only a part of the inner laminated structure. For example, a partial laminated structure 1502 can be laminated on a part of the laminated structure 1501 as shown in Figure 15. In this embodiment, by incorporating such a partially laminated structure 1502 with aesthetic appeal, the anisotropy of the strength of the inner laminated structure 1503 can be mitigated or its strength in a specific area can be increased. In addition, the structure itself can be used to add aesthetic appeal and repair cracks. Furthermore, similar to the first embodiment described above, the laminated structure 1503 is a laminated structure with a continuous, unbroken bead. In addition, the outer laminated structure 1502 can also be fabricated as a laminated structure with a continuous, unbroken bead. [Explanation of Symbols]

[0029] 101 Cylinder 201, 401, 801, 1001, 1301, 1401, 1501, 1503 Laminated Structure 202, 1002 bottom 203 Top 204, 301, 302, 402, 802, 1003, 1004, 1302, 1303 Bead 601 Material discharge section 602 Support stand 701 Robot Arm 1101, 1201 disk layers 1402 Lamination starting point 1403 Lamination end point 1502 Partially laminated structure

Claims

1. A first structure in which a single bead adjacent to multiple locations is stacked such that the longitudinal direction of the adjacent portion is in a predetermined direction, A second structure is laid in close contact with the first structure, with the single bead laminated such that the longitudinal direction of the adjacent portion is in a direction different from the predetermined direction. A laminated structure equipped with this feature.

2. The laminated structure according to claim 1, characterized in that the single bead is laminated in a single continuous line.

3. The laminated structure according to claim 2, characterized in that the first or second structure is made by stacking the single bead in a spiral manner.

4. The laminated structure according to claim 2, characterized in that the first or second structure is formed by closely adhering multiple layers formed by stacking the single beads.

5. The laminated structure according to claim 1, characterized in that the single bead contains a single fiber connected between both ends.

6. The laminated structure according to claim 1, characterized in that the second structure is in close contact with the entire first structure.

7. The laminated structure according to claim 1, characterized in that the second structure is in close contact with a part of the first structure.

8. The laminated structure according to claim 1, characterized in that the second structure is in close contact with the outside of the first structure.

9. A method for fabricating a three-dimensional layered structure by obtaining the necessary toolpaths from three-dimensional shape data, A toolpath calculation step calculates a toolpath formed by stacking adjacent single beads at multiple locations, A first forming step in which, based on the calculated toolpath, the single bead is stacked such that the longitudinal direction of the adjacent portion is in a predetermined direction to form a first structure, A second forming step involves forming a second structure by stacking the single bead in close contact with the first structure based on the calculated toolpath, such that the longitudinal direction of the adjacent portion is different from the predetermined direction. A method for fabricating laminated structures, comprising the features described above.

10. The method for fabricating a laminated structure according to claim 9, characterized in that the first structure or the second structure is formed by bonding together a plurality of layers in which the single beads are stacked.

11. The method for fabricating a laminated structure according to claim 10, characterized in that the direction of the toolpath for the odd-numbered layers, including the bottom layer, and the even-numbered layers, including the layer following the bottom layer, are reversed.

Images