columnar structure

Abstract

An object of the present invention is to provide a lightweight pillar structure that can support vertical loads and eccentric loads. [Solution] A columnar structure is provided, which is composed of multiple parts and is characterized by comprising: a compression section compressed in a first direction and having compressive stress; a first support section and a second support section connected to both ends of the compression section in the first direction, respectively, for receiving the load in the first direction; and multiple tension sections connected to the first support section and the second support section, respectively, and which apply a force compressing the compression section in the first direction by pulling the first support section and the second support section.

Description

[Technical Field]

[0001] The present invention relates to a pillar structure. [Background technology]

[0002] One additive manufacturing technology that uses 3D printers, etc., is a method of melting and laminating heated thermoplastic filaments (fused deposition modeling). This fused deposition modeling has advantages such as not requiring molds for modeling and allowing for a high degree of freedom in shape, and in recent years, further research and development into improving materials and processes has been progressing.

[0003] Non-Patent Document 1 discloses a chair manufactured using a 3D printer. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] "Manufacturing with 3D printers towards a carbon-free society," Okamura Corporation, [online], [Retrieved June 24, 2024], Internet<URL: https: / / www.okamura.co.jp / office / special_site / product / 3dprinterchair / > Summary of the Invention [Problem to be solved by the invention]

[0005] In addition to vertical loads, eccentric loads may be applied to structures such as chairs. The chair disclosed in Non-Patent Document 1 is made of a low-strength bio-polyethylene material. Therefore, the chair is thick to support both the vertical load and the eccentric load, and is therefore heavy.

[0006] Therefore, an object of the present invention is to provide a lightweight pillar structure that can support vertical loads and eccentric loads. [Means for solving the problem]

[0007] The columnar structure according to the first aspect of the present invention comprises: (1) A columnar structure composed of multiple parts, a compressed portion compressed in a first direction and having a compressive stress; a first support portion and a second support portion connected to both ends of the compression portion in the first direction, respectively, for receiving a load in the first direction; a plurality of tension portions respectively connected to the first support portion and the second support portion, and configured to apply a force compressing the compression portion in the first direction by pulling the first support portion and the second support portion; The columnar structure is characterized by comprising:

[0008] The columnar structure according to one embodiment of the present invention comprises: (2) The columnar structure according to (1) is characterized in that it further comprises a support member that supports the connection between the compression portion and the first support portion and the second support portion.

[0009] In a columnar structure according to one embodiment of the present invention, (3) The columnar structure according to (1) or (2) is characterized in that the tension portion is disposed in a position that covers the outer periphery of the compression portion when viewed from the first direction.

[0010] In a columnar structure according to one embodiment of the present invention, (4) The columnar structure according to any one of (1) to (3) is characterized in that at least three of the tension portions are provided.

[0011] In a columnar structure according to one embodiment of the present invention, (5) The columnar structure according to any one of (1) to (4), wherein the compression portion includes a truss structure formed of beams inclined with respect to the first direction.

[0012] In a columnar structure according to one embodiment of the present invention, (6) The columnar structure according to any one of (1) to (5), characterized in that the multiple parts constituting the compression section, the first support section, the second support section, and the tension section are made of a resin composition containing reinforcing fibers, and the reinforcing fibers in the resin composition are oriented along the maximum principal stress axis of the parts.

[0013] In a columnar structure according to one embodiment of the present invention, (7) The columnar structure according to any one of (1) to (6), wherein at least some of the plurality of components have slits formed therein that extend along the maximum principal stress axis.

[0014] In a columnar structure according to one embodiment of the present invention, (8) The columnar structure according to any one of (1) to (7), wherein the plurality of parts have different moduli of elasticity or strength.

[0015] In a columnar structure according to one embodiment of the present invention, (9) The columnar structure according to any one of (1) to (8), wherein at least some of the plurality of parts are formed by a 3D printer. [Effects of the Invention]

[0016] According to the present invention, it is possible to provide a lightweight pillar structure that can support vertical loads and eccentric loads. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a perspective view showing an example of the configuration of a columnar structure according to the present embodiment. [Figure 2] FIG. 2 is a front view showing the columnar structure of FIG. [Figure 3] FIG. 2 is a plan view showing the columnar structure of FIG. [Figure 4] FIG. 2 is a left side view showing the columnar structure of FIG. [Figure 5] FIG. 2 is a right side view showing the columnar structure of FIG. [Figure 6] FIG. 2 is a rear view showing the columnar structure of FIG. [Figure 7] FIG. 2 is a bottom view showing the columnar structure of FIG. [Figure 8] FIG. 2 is a cross-sectional view taken along line CC in FIG. [Figure 9] 2A and 2B are views showing the main support components of the support member of FIG. 1; [Figure 10] FIG. 10 is a partially enlarged view of FIG. [Figure 11] FIG. 10 is a partially enlarged view of FIG. [Figure 12] 2 is a diagram showing a joint of the tension portion of FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. Note that the present invention is not limited to the following embodiment, and various modifications can be made within the scope of the gist of the present invention.

[0019] 1 to 8 are diagrams showing a pillar structure 1000 as an embodiment of the pillar structure according to the present invention.

[0020] The columnar structure 1000 of this embodiment includes a compression section 100, a first support section 200, a second support section 300, and a plurality of tension sections 400 (three in FIG. 1).

[0021] The pillar structure 1000 may be a chair or a table. The pillar structure 1000 may also be the legs of a table. The pillar structure 1000 may also be the foundation of a building.

[0022] The outer diameter or height of the columnar structure 1000 may be set appropriately.

[0023] The columnar structure 1000 is made up of a plurality of parts. Specifically, the columnar structure 1000 may be made up of the parts shown in Table 1, which will be described later.

[0024] The elastic modulus or strength of the multiple parts may be different. For example, the elastic modulus and strength of the parts may be different by varying the content ratio of reinforcing fibers in the parts. The content of continuous fiber or short fiber in the parts may also be different. Specifically, each part may contain the continuous fiber shown in Table 1.

[0025] At least some of the multiple parts may be formed by a 3D printer. The 3D printer may use fused deposition modeling (FDM) to create the parts. The 3D printer may use powder modeling or optical modeling to create the parts. All of the multiple parts may be formed by the 3D printer.

[0026] The components constituting the columnar structure 1000, more specifically, the multiple components constituting the compression section 100, the first support section 200, the second support section 300, and the tension section 400, may be made of a resin composition containing reinforcing fibers. More specifically, the components may be manufactured by impregnating reinforcing fiber filaments with resin. The reinforcing fibers in the resin composition may be oriented along the maximum principal stress axis of the component. The maximum principal stress axis here may be, for example, the maximum principal stress axis that occurs in the component when a compressive force along the first direction d1 is applied to the center of gravity of the columnar structure 1000. When an expected eccentric load is applied to the columnar structure 1000, the reinforcing fibers may be oriented along the maximum principal stress axis that occurs in the component.

[0027] Slits may be formed in the component to set the arrangement of the reinforcing fibers. For example, slits 510S1, 510S2, and 510S3 may be formed in the main support component 510 of the support member 500. The orientation of the reinforcing fibers may be different in each layer of the component, for example, by forming slits with different extension directions. Details will be described later.

[0028] The resin may be a thermoplastic resin, such as a phenoxy resin, an acrylic resin, a methacrylic resin, a polyvinyl acetal resin, a thermoplastic polyimide resin, a polyamide resin, a polyamideimide resin, a polyphenylene oxide resin, a polyethersulfone resin, a polyester resin, a polyethylene resin, a polystyrene resin, a polysulfone resin, a polybutadiene resin, an ABS resin, a coumarone resin, a polyolefin resin, or a polyarylene sulfide resin.

[0029] The thermoplastic resins may be used singly or in combination of two or more types having, for example, different weight average molecular weights, or in combination of one or more types and their prepolymers.

[0030] Among these, it is preferable to include a polyamide resin, for example, in view of compatibility with carbon fibers.

[0031] Types of reinforcing fibers that may be used in the parts include carbon fiber, glass fiber, aramid fiber, boron fiber, PBO fiber, high-strength polyethylene fiber, alumina fiber, silicon carbide fiber, etc. Carbon fiber is preferred from the viewpoints of mechanical properties, thermal properties, and versatility.

[0032] The reinforcing fibers may be used alone or in combination of two or more.

[0033] The reinforcing fibers are preferably continuous reinforcing fibers. The form or arrangement of the fibers is not limited, and examples thereof include fiber structures such as unidirectionally aligned long fibers, a single tow, woven fabrics, knitted fabrics, and braided cords, but unidirectionally aligned long fibers are most preferred.

[0034] Carbon fiber is a fiber made by carbonizing acrylic fiber or pitch (a by-product of petroleum, coal, coal tar, etc.) at high temperatures. Acrylic carbon fiber, which has high tensile strength, is particularly preferred.

[0035] The compressed portion 100 is compressed in a first direction d1 and has a compressive stress. The first direction d1 may be parallel to the central axis A of the compressed portion 100. The compressed portion 100 may be compressed in the first direction d1 due to a vertical load. The compressed portion 100 does not need to deform significantly when compressed in the first direction d1.

[0036] The compression section 100 may include a truss structure 110 .

[0037] The truss structure 110 is composed of beams 111 that are inclined with respect to a first direction d. The angle of the beams 111 with respect to the first direction d1 is defined as θ. θ can be set appropriately, and may be 3° or more. θ may be 5° or more, and more preferably, 10° or more and less than 30°. The beams 111 may be plate-shaped. The beams 111 may be made of resin.

[0038] The truss structure 110 may be composed of a plurality of (four in FIG. 1 ) beam pairs 111T. The plurality of beam pairs 111T may be arranged around the central axis A of the compression section 100. In a configuration in which four beam pairs 111T are provided, the beam pairs 111T may be arranged at 90° intervals around the circumference of the compression section 100.

[0039] The beam pair 111T may include two beams 111. The two beams 111 may be inclined in opposite directions relative to the first direction d1. The main surfaces of the two beams 111 may be parallel to each other.

[0040] The truss structure 110 may further include two plates 112. Respective ends of the beam 111 may be connected to the two plates 112. The main surface of the plate 112 may be disposed perpendicular to the first direction d1. The plate 112 may be a circular plate.

[0041] The truss structure 110 can achieve a higher compressive strength with less material than a cylindrical structure. The bending deformation of the truss structure 110 can be suppressed by increasing the elastic modulus of the constituent members.

[0042] The first support member 200 and the second support member 300 are connected to both ends of the compression member 100 in the first direction d1, respectively. The first support member 200 and the second support member 300 may receive a load in the first direction d1. For example, a load may be applied to the first support member 200 and the second support member 300, respectively, along the first direction d1 toward the center of gravity of the columnar structure 1000. An eccentric load may be applied to the first support member 200 and the second support member 300, respectively, along the first direction d1 but away from the center of gravity of the columnar structure 1000. An impact may also be applied to the first support member 200 and the second support member 300.

[0043] The first support part 200 and the second support part 300 may have the same configuration. Unless otherwise specified below, the description of the first support part 200 also applies to the second support part 300.

[0044] The first support portion 200 may include a support surface 210 and a receiving portion 220. In a configuration in which the columnar structure 1000 is a chair, the first support portion 200 may further include a backrest.

[0045] The first support portion 200 may have a rounded triangular shape in plan view, but is not limited to this shape. The first support portion may also have a square or circular shape in plan view.

[0046] The support surface 210 may be provided on the top of the columnar structure 1000 as shown in Fig. 1 and / or on the bottom of the columnar structure 1000. When present on top of the columnar structure 1000, the support surface 210 supports an object placed thereon. In a configuration in which the columnar structure 1000 is a chair, the support surface 210 may be a seat plate. The support surface 210 may be solid, but is not limited to this shape. The support surface 210 may also be mesh-like.

[0047] The receiving portion 220 receives and supports the support surface 210. In a configuration in which the support surface 210 is plate-shaped, the receiving portion 220 may contact at least a part of the side and bottom surfaces of the support surface 210. A through-hole 221 may be formed in the center of the receiving portion 220.

[0048] The columnar structure 1000 may further include support members 500 and 600. The support member 500 supports the connection between the compression portion 100 and the first support portion 200. The support member 600 supports the connection between the compression portion 100 and the second support portion 200. The support members 500 and 600 may have the same configuration. Unless otherwise specified below, the description of the support member 500 also applies to the support member 600.

[0049] The support member 500 may include a main support component 510 , a secondary support component 520 , and a plate 530 .

[0050] The main support part 510 of the support member 500 connects the receiving part 220 of the first support part 200 and the plate 530 of the support member 500. The main support part 510 of the support member 600 connects the receiving part 220 of the second support part 300 and the plate 530 of the support member 600. The main support part 510 may be connected to the receiving part 220 of the first support part 200 or the second support part 300 near the tension part 400.

[0051] 9, the main support component 510 may be plate-shaped. One 510P1 of two protrusions 510P1, 510P2 formed at one end of the main support component 510 may be inserted into a slit formed in the bottom surface of the receiving portion 220. Surfaces 510F1, 510F2 adjacent to the protrusion 510 may abut against the bottom surface of the receiving portion 220. The other protrusion 510P2 may be inserted into a slit formed in the side surface of the tension bar 410 of the tension unit 400. Surface 510F3 adjacent to the protrusion 510P2 may abut against the side surface of the tension bar 410.

[0052] One 510P3 of two protrusions 510P3, 510P4 formed on the other end of the main support component 510 may be inserted into a slit formed in the upper surface of the plate 530. A surface 510F4 adjacent to the protrusion 510P3 may abut against the upper surface of the plate 530. The other protrusion 510P4 may be inserted into a slit formed in the side surface of the tension bar 410 of the tension unit 400.

[0053] Slits 510S1, 510S2, and 510S3 may be formed in the main support component 510. The slits 510S1, 510S2, and 510S3 may extend along the longitudinal direction d2 of the main support component 510. The corners of the slits 510S1, 510S2, and 510S3 may be rounded.

[0054] By forming the slits 510S1, 510S2, and 510S3, distortion of the main support component 510 can be suppressed, and reinforcing fibers can be effectively arranged.

[0055] 10 and 11, on both sides 510A, 510B of the slit 510S1, the reinforcing fibers are oriented along the longitudinal direction d2 of the main support component 510. Here, the longitudinal direction d2 of the main support component 510 may coincide with the axis of maximum principal stress. This configuration can effectively improve the strength of the main support component 510, and therefore the strength of the columnar structure 1000.

[0056] 11, in the region 510C between the slits 510S1 and 510S2, the reinforcing fibers are oriented along the edges of the slits 510S1 and 510S2. In other words, the reinforcing fibers are oriented toward the width direction d3 of the main support component 510. This orientation can suppress bending deformation of the main support component 510.

[0057] 1, the sub-support component 520 may include a rod-shaped portion 520B and a plate portion 520P provided at one end of the rod-shaped portion 520B. The plate portion 520P may be disk-shaped.

[0058] The sub-support component 520 may connect the main support component 510 and the receiving portion 220 of the first support part 200. The sub-support component 520 may be fixed to a fixing portion 510S2F (FIGS. 9 and 11) of the slit 510S2 of the main support component 510. More specifically, the outer edge of the plate portion 520P of the sub-support component 520 may be fixed to the inner edge of the fixing portion 510S2F.

[0059] 12, the tension unit 400 may include two tension bars 410 and a joint 420 that pulls the two tension bars 410. Referring to FIG. 1, the two tension bars 410 of the tension unit 400 are connected to the first support unit 200 or the second support unit 300, respectively.

[0060] A plurality of tensioning sections 400 are provided. Preferably, three or more tensioning sections 400 are provided. The plurality of tensioning sections 400 may be arranged around the central axis A of the columnar structure 1000. In a configuration in which three tensioning sections 400 are provided, the tensioning sections 400 may be arranged at intervals of 120° in the circumferential direction of the columnar structure 1000.

[0061] The tension bar 410 may be rod-shaped, spring-shaped, or string-shaped, and may be made of resin or metal.

[0062] Referring to FIG. 12, a joint 420 may include a first member 421, a second member 422, and two screws 423 and 424.

[0063] The tension unit 400 applies a force compressing the compression unit 100 in the first direction d1 by pulling the first support unit 200 and the second support unit 300. More specifically, the joint 420 may pull two tension bars 410. The two tension bars 410 may pull the first support unit 200 and the second support unit 300, respectively. The pulled first support unit 200 and second support unit 300 compress the compression unit 100 in the first direction d1, generating compressive stress. In a state where no external force is applied to the columnar structure 1000, the tension unit 400 may pull the first support unit 200 and the second support unit 300, applying a force compressing the compression unit 100 in the first direction d1.

[0064] Different tension bars 410 may be fixed to the first member 421 and the second member 422. The first member 421 and the second member 422 may be spaced apart in the first direction d1. Two screws 423, 424 pass through through holes in the first member 421 and the second member 422. The through holes may be threaded. Tightening the screws 423, 424 may bring the first member 421 and the second member 422 closer to each other. By bringing the first member 421 and the second member 422 closer to each other, the two tension bars 410 may be pulled, generating a greater tension.

[0065] An eccentric load may be applied to the first support member 200 at a position P different from the center of gravity of the first support member 200 along the first direction d1. This load generates a moment that tilts the first support member 200. In response to this load, tension increases in the tension bar 410 of the tension member 400 that is far from P. This increased tension cancels out the moment caused by the eccentric load. In this way, even if an eccentric load is applied to the first support member 200, the moment that tilts the first support member 200 can be reduced. This improves stability when an eccentric load is applied to the first support member 200. Furthermore, tension decreases in the tension bar 410 of the tension member 400 that is closer to P. However, because the tension bar 410 is strongly pulled by the joint 420, compression of the tension bar 410 can be avoided. This prevents buckling deformation of the tension bar 410, thereby improving the durability of the tension bar 410. [Example]

[0066] The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0067] The pillar structure 1000 shown in Fig. 1 to Fig. 8 was manufactured using the parts shown in Table 1. In addition to the parts shown in Table 1, screws 423 and 424 were used. The parts were basically connected to each other with an adhesive.

[0068] [Table 1]

[0069] The parts were formed using a 3D printer using a filament made of polyamide resin or a filament made of carbon fiber impregnated with polyamide resin. The carbon fiber was continuous. Specifically, the heated filament was melt-laminated. The nozzle temperature was 270-290°C. The print width was approximately 0.5-0.8 mm for resin-only filaments and approximately 1 mm for carbon fiber filaments. The lamination thickness was approximately 0.1-0.15 mm. The stage temperature was room temperature (no control). The 3D printer used was a Mark Two from Markforged (registered trademark).

[0070] The carbon fiber ratio varies depending on the part. The specific ratios are shown in Table 1.

[0071] The structure differs depending on the part. The structure of each part is either a solid structure, an infill hollow structure, or a network structure, as shown in Table 1. More specifically, a plurality of columnar structures 1000 were manufactured. The support surface 210 of the columnar structures 1000 was a triangular shape with alternating vertical and horizontal laminations, a honeycomb structure, a rectangular shape with alternating vertical and horizontal laminations, or a gyroid.

[0072] Even when an adult male sat on the center and edge of the support surface 210 of the manufactured columnar structure 1000, the columnar structure 1000 was not damaged. Therefore, it was revealed that the columnar structure 1000 can support vertical loads and eccentric loads equivalent to those of a general chair.

[0073] As shown in Table 1, the total weight of the columnar structure 1000 is 828 grams. A typical chair weighs several kilograms. Therefore, the columnar structure 1000 is shown to be lightweight. [Industrial Applicability]

[0074] The columnar structure of the present invention is suitable for application to chairs or tables, table legs, or building foundations. [Explanation of symbols]

[0075] 1000 columnar structure 100 Compression section 110 Truss Structure 111 Beam 111T beam pair 112 board 200,300 Support part (1st support part, 2nd support part) 210 Support surface 220 Receiving part 221 Through hole 400 Tension section 410 Tension bar 420 Joint 421 First member 422 Second member 423,424 Screws 500,600 support members 510 Main support parts 510P1, 510P2, 510P3, 510P4 Convex part 510S1, 510S2, 510S3 Slit 510F1,510F2,510F3,510F4 side 510S2F Fixed part 510A, 520B, 510C part 520 Sub-support parts 520B Rod-shaped part 520P plate part 530 board A Center axis P position d1 1st direction d2 Longitudinal direction d3 Width direction

Claims

1. A columnar structure composed of multiple parts, a compressed portion compressed in a first direction and having a compressive stress; a first support portion and a second support portion connected to both ends of the compression portion in the first direction, respectively, for receiving a load in the first direction; a plurality of tension portions respectively connected to the first support portion and the second support portion, and configured to apply a force compressing the compression portion in the first direction by pulling the first support portion and the second support portion; A pillar structure comprising:

2. The columnar structure according to claim 1 , further comprising a support member that supports connection between the compression portion and the first support portion and the second support portion.

3. 3. The columnar structure according to claim 1, wherein the tension portion is disposed at a position that covers an outer periphery of the compression portion when viewed from the first direction.

4. The pillar structure according to claim 3 , wherein at least three tension portions are provided.

5. The columnar structure according to claim 1 or 2, wherein the compression portion includes a truss structure formed of beams inclined with respect to the first direction.

6. 3. A columnar structure as described in claim 1 or 2, characterized in that the multiple parts constituting the compression section, the first support section, the second support section and the tension section are made of a resin composition containing reinforcing fibers, and the reinforcing fibers in the resin composition are oriented along the maximum principal stress axis of the parts.

7. The columnar structure according to claim 6, wherein at least some of the plurality of components are formed with slits extending along the axis of maximum principal stress.

8. The columnar structure according to claim 1 or 2, wherein the plurality of parts have different elastic moduli or strengths.

9. The columnar structure according to claim 1 or 2, wherein at least some of the plurality of parts are formed by a 3D printer.

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