Joint structure and joining members of structural materials

Abstract

To provide a joint structure of a structural material which enables two structural materials to be joined easily with stable and high strength, and to provide a joint member.SOLUTION: In a joint structure 1 of structural materials, two structural materials 10, 12 each including a cutout part at an end are arranged so that the cutout parts 16, 18 of the two structural materials 10, 12 are butted to form a joint hole 20. A joint member 14 having a shape which corresponds to a shape of the joint hole 20 is inserted into the joint hole 20 to join the two structural materials 10, 12. The joint member 14 includes an elastic fitting part having a diameter larger than that of the joint hole 20 and including an air gap therein. The elastic fitting part is compressed inward when inserted into the joint hole 20 and restored to be fitted in the joint hole 20 during fitting.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a joining structure for structural materials and a joining member used in such a joining structure. [Background technology]

[0002] BACKGROUND ART Conventionally, as a joining structure for wooden structural materials such as interior materials for buildings and furniture, a joining structure for structural materials using joining members such as butterfly joints (shredded joints) has been known.

[0003] As a joining structure for structural materials using joining members, for example, a joining structure has been proposed that includes a first wooden panel, a second wooden panel, and a shredded joining member that joins the first wooden panel and the second wooden panel, where the joining structure has an allowable strength of approximately 10 kN or more, the joining member includes a laminated timber made up of multiple stacked plate materials, the multiple plate materials including first plate materials having a first fiber direction and second plate materials having a second fiber direction different from the first fiber direction, the total volume of the first plate materials being larger than the total volume of the second plate materials, and the height direction of the joining member being approximately the same as the first fiber direction (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6846561 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the joint strength of conventional joint structures for structural materials is not necessarily sufficient.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a structural material joining structure and joining member that can easily join two structural materials with stable, high strength. [Means for solving the problem]

[0007] As a result of extensive research into joining structures for structural materials using joining members, the inventors discovered that by using a joining member that has an elastic fitting portion that has a diameter larger than the joining hole of the structural material and has a void inside, the elastic fitting portion that is compressed inward when inserted into the joining hole will return to its original shape when fitted and fit into the joining hole, thereby making it possible to join two structural materials with high strength, which led to the completion of the present invention.

[0008] That is, the present invention is as follows. [1] A joining structure for structural materials, in which two structural materials each having a notch at an end are arranged so that the notch portions of the two structural materials butt together to form a joining hole, and a joining member corresponding to the shape of the joining hole is inserted into the joining hole, The joining member has an elastic fitting portion having a diameter larger than the joining hole and having a gap therein, and the elastic fitting portion is compressed inward when inserted into the joining hole and returns to its original shape when fitted into the joining hole. A joining structure for structural materials characterized by the above. [2] The joining member is a pilot portion provided below the elastic fitting portion, having a diameter equal to or smaller than that of the connecting hole, and being inserted into the connecting hole first; a cover portion provided above the elastic fitting portion, having a diameter large enough to be inserted into the joining hole without a gap, and forming the same plane as the upper surfaces of the two structural members; The joining structure of structural materials according to [1] above, characterized in that it comprises: [3] The joining structure of structural materials according to [1] or [2] above, characterized in that the circumferential length of the elastic fitting portion of the joining member is longer than the circumferential length of the joining hole. [4] The joining structure for structural materials according to any one of [1] to [3] above, wherein the joining member is gourd-shaped in plan view. [5] The joint structure for structural materials according to any one of the above [1] to [4], wherein the bottom of the joint member is rounded. [6] The joint structure for structural materials according to any one of the above [1] to [5], wherein the joint member is made of a plant-derived resin. [7] The joining structure of structural materials according to [6] above, characterized in that the plant-derived resin is polylactic acid (PLA). [8] The joining structure of structural materials according to [6] or [7] above, characterized in that the joining member is a member integrally formed by a 3D printer. [9] A joining member used in the joining structure of the structural material according to any one of [1] to [8] above.

[10] A structure comprising the joint structure of the structural materials according to any one of [1] to [8] above.

[11] A joining member that is formed in a shape corresponding to the shape of a joining hole formed by butting together the notched portions of two structural members each having a notched portion at an end thereof, and that fits into the joining hole to join the two structural members, The connector is provided with an elastic fitting portion having a diameter larger than that of the connecting hole and having an internal void, the elastic fitting portion being compressed inward when inserted into the connecting hole and restoring to its original shape when fitted into the connecting hole. A joining member characterized by: [Effects of the Invention]

[0009] The joining structure and joining member for structural materials of the present invention can easily join two structural materials with stable high strength. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an explanatory diagram of a joining structure for structural materials according to a first embodiment of the present invention, showing the state before two structural materials are joined. [Figure 2]FIG. 1 is an explanatory diagram of a joining structure for structural materials according to a first embodiment of the present invention, and is a schematic diagram of the state after two structural materials have been joined. [Figure 3] 2 is a schematic side view of a gourd-shaped joining member of the joining structure of the structural material shown in FIG. 1. FIG. [Figure 4] 2 is a schematic cross-sectional view of a gourd-shaped joining member of the joining structure of the structural material shown in FIG. 1. FIG. [Figure 5] 10A and 10B are explanatory diagrams of a round dumbbell-shaped joint member of a joining structure of a structural material according to a second embodiment of the present invention, where (a) is an oblique view, (b) is a side view, (c) is a plan view, and (d) is a schematic cross-sectional view. [Figure 6] 10A to 10D are explanatory diagrams of a square dumbbell-shaped joining member of a joining structure of structural materials according to a third embodiment of the present invention, where (a) is an oblique view, (b) is a side view, (c) is a plan view, and (d) is a schematic cross-sectional view. [Figure 7] 10A to 10D are explanatory diagrams of a diamond-shaped joining member of a joining structure of structural materials according to a fourth embodiment of the present invention, in which (a) is a perspective view, (b) is a side view, (c) is a plan view, and (d) is a schematic cross-sectional view. [Figure 8] 10A to 10D are explanatory diagrams of an arrow-shaped joining member of a joining structure of structural materials according to a fifth embodiment of the present invention, where (a) is a perspective view, (b) is a side view, (c) is a plan view, and (d) is a schematic cross-sectional view. [Figure 9] Photographs showing the gourd-shaped joint member produced in the example, where (a) is a diagonal photograph from above, (b) is a side photograph, (c) is a plan photograph, and (d) is a diagonal photograph from below. [Figure 10] 1A and 1B are photographs of a structure having a joining structure of structural materials using the joining member of the present invention produced in an example, where (a) is an overall photograph and (b) is an enlarged photograph of the joining portion. DETAILED DESCRIPTION OF THE INVENTION

[0011] The joining structure for structural materials of the present invention is a joining structure for structural materials in which two structural materials each having a notch at its end are arranged so that the notches of the two structural materials are butted together to form a joining hole, and a joining member corresponding to the shape of the joining hole is inserted into the joining hole, thereby joining the two structural materials, wherein the joining member has an elastic fitting portion which has a diameter larger than the joining hole and has an internal void, and the elastic fitting portion is compressed inward when inserted into the joining hole, and returns to its original shape when fitted so as to fit into the joining hole.

[0012] The joining structure of structural materials of the present invention can easily join two structural materials with stable high strength.

[0013] The joining structure for structural materials of the present invention can be suitably used for joining building interior materials and furniture materials such as base materials, wooden parts, tabletops, shelves, etc. It can also be used for the purpose of reinforcing structural materials and improving their design.

[0014] As described above, the joining structure of structural materials of the present invention comprises two structural materials each having a notch at its end, and a joining member.

[0015] [Structural material] First, the structural material of the present invention will be described. The joining structure for structural materials of the present invention comprises two structural materials. The two structural materials each have a notch at their end, and are arranged so that the notches of the structural materials butt together to form a joining hole. In other words, when the two structural materials are placed adjacent to each other, the end side surfaces having the notches can abut (see Figure 1). The shape of the ends of the structural materials may be straight or curved as long as they match when butted together, but is usually straight.

[0016] The material of the structural member is not particularly limited, but wood is preferable. The structural member may have various shapes, such as a plate, a rectangular pillar, or a block.

[0017] When the structural material is a wooden flat plate member, the structural material may be arranged, for example, with the end grain surfaces butted together, with the end grain surfaces of the structural material butted together, or with the end grain surface or end grain surface of the structural material butted against the front or back wood surface of the structural material.

[0018] (Notch) The notch is a hole cut inward from the end side of the structural material. The notch may be formed so as to penetrate through the top and bottom surfaces of the structural material, but it is preferable that it does not penetrate all the way through. Furthermore, it is preferable that the gap width of the notch at a position a predetermined distance inward from the end side of the structural material is longer than the gap width at the end side of the structural material (the length of the gap formed at the end side of the structural material). In other words, it is preferable that the notch has a portion that is formed narrower toward the end side of the structural material. This increases the bonding strength against forces that try to pull the two structural materials apart.

[0019] (joining hole) A joint hole is a hole formed by butting together the cutouts of two structural materials. In other words, a joint hole is formed by connecting two holes formed in structural materials to form a single hole.

[0020] The joining hole may be symmetrical or asymmetrical about the butted end side surfaces of the two structural members, but a symmetrical shape is preferred. In other words, it is preferable that the two structural members have cutouts of the same shape.

[0021] [Connection material] Next, the joining member of the present invention will be described. The joining member is formed to a shape corresponding to the shape of the joining hole, and is equipped with an elastic fitting portion having a larger diameter than the joining hole and an internal void. In other words, the joining member is formed to have approximately the same shape as the joining hole, and is inserted into the joining hole, and the elastic fitting portion fits into the joining hole inside the joining hole, thereby joining the two structural members.

[0022] (Shape of joining material) Examples of the shape of the joining member when viewed from above include a gourd shape (see FIG. 3), a round dumbbell shape (see FIG. 5), a square dumbbell shape (see FIG. 6), a diamond shape (see FIG. 7), an arrow shape (see FIG. 8), a butterfly joint shape (shredded shape), an anchor shape, etc. From the viewpoint of ease of processing, the shape of the joining member is preferably one having a circular portion when viewed from above, and specifically, a gourd shape or a round dumbbell shape is preferred, with a gourd shape being more preferred.

[0023] (Size of joining parts) The overall size of the joining member is not particularly limited and can be changed appropriately depending on the application, but for example, it may have a maximum length (see X in FIG. 1) of 10 to 400 mm, a maximum width (see Y in FIG. 1) of 5 to 200 mm, and a maximum height (see Z in FIG. 1) of 5 to 200 mm, preferably a maximum length of 10 to 100 mm, a maximum width of 5 to 50 mm, and a maximum height of 5 to 50 mm, more preferably a maximum length of 12 to 60 mm, a maximum width of 6 to 30 mm, and a maximum height of 6 to 30 mm, and even more preferably a maximum length of 14 to 20 mm, a maximum width of 7 to 10 mm, and a maximum height of 7 to 10 mm.

[0024] When the joining hole has a shape having a circular portion in a plan view, the joining member has a diameter (Y in Figure 1) of, for example, 5 to 200 mm, preferably 5 to 50 mm, more preferably 6 to 30 mm, and even more preferably 7 to 10 mm.

[0025] The elastic fitting portion of the joining member has a diameter larger than the joining hole and has an internal gap, and is compressed inward when inserted into the joining hole and returns to its original shape when fitted into the joining hole. Here, "the elastic fitting portion has a diameter larger than the joining hole" means that there is a portion of the periphery with a larger diameter to the extent that the structural material can be joined, and at least each notch portion has a larger diameter. Therefore, the elastic fitting portion is formed, for example, with a circumferential length longer than that of the joining hole.

[0026] Specifically, it is preferable that the elastic fitting portion has a portion that protrudes outward from the outer periphery of the joining hole by approximately 0.2 to 8.0 mm, more preferably by 0.3 to 3.0 mm, and even more preferably by 0.4 to 1.0 mm.

[0027] The gap of the elastic fitting is a space formed inside the elastic fitting. The gap compresses inward during insertion, allowing a large-diameter elastic fitting to be inserted into the joining hole. The gap also functions as a cushioning material (buffer material) to absorb impact when, for example, hammering the joining member into the joining hole.

[0028] The gap is preferably provided at a position a predetermined distance inward from the peripheral wall of the elastic fitting portion, and is preferably disposed at a position corresponding to the center of each of the cutouts of the two structural members in plan view. The gaps may be interconnected.

[0029] In an embodiment in which a gap is provided at the center of each of the cutouts of the two structural materials, the shape of each gap is preferably circular in plan view, such as spherical, ellipsoidal, cylindrical, or biconical, with spherical or ellipsoidal being preferred. This allows for efficient dispersion of the vertical force during insertion, improving durability. The height (vertical length) of the gap may be a portion of the height of the elastic fitting portion, but is preferably greater than or equal to the height of the elastic fitting portion.

[0030] In an embodiment in which the gap forms a circle in plan view, the maximum diameter of the circle can be set appropriately depending on the size of the connecting member, but is, for example, 2.0 to 80 mm, preferably 2.5 to 25 mm, more preferably 3.0 to 15 mm, and even more preferably 3.5 to 5.0 mm.

[0031] The joining member of the present invention preferably includes a pilot portion and a lid portion, respectively, below and above the elastic fitting portion. That is, a preferred embodiment of the joining member includes a pilot portion below the elastic fitting portion, having a diameter equal to or smaller than that of the joining hole, and being inserted first into the joining hole, and a lid portion above the elastic fitting portion, having a diameter large enough to be inserted into the joining hole without a gap, and forming a flush surface with the upper surfaces of the two structural members. The elastic fitting portion, pilot portion, and lid portion may be molded separately, but are preferably molded integrally. The pilot portion, which forms the bottom, is preferably rounded, which allows for smooth insertion into the joining hole.

[0032] Examples of materials for the elastic fitting portion include plastic (synthetic resin) and rubber, with plastic being preferred. Plastics that can be used in 3D printers are preferred, with specific examples including rigid polyvinyl chloride resin, polypropylene resin, rigid polyethylene resin, and polylactic acid (PLA), with polylactic acid being preferred. Polylactic acid is a plant-derived biodegradable plastic made from starch found in corn and other crops, and is a carbon-neutral, environmentally friendly material. Furthermore, plastic (synthetic resin) and rubber are compatible with resin adhesives such as wood glue (aqueous adhesives containing vinyl acetate resin), which can improve bonding strength. Furthermore, bonding is environmentally friendly because it can be performed without the use of conventional metal fittings such as metal studs, tie plates, bolts, and nuts.

[0033] It is preferable to use the same material for the entire joining part (pilot part and lid part) as for the elastic fitting part. For example, if it is made of a plastic that is compatible with 3D printers, the entire joining part can be integrally formed using a 3D printer. Compared to joining structures of structural materials using conventional joining parts, using a 3D printer does not require skilled techniques, and product quality is not affected by the skill of the worker, so it can be used as a standardized or pre-made product. It also shortens processing time and reduces costs, and allows for flexible size changes.

[0034] Next, a structure using the joining structure of the structural material of the present invention will be described. The structure of the present invention includes a structure having the above-described joint structure, such as furniture and its components, and buildings and its components.

[0035] Next, a joining member that can be applied to the joining structure of the structural material of the present invention will be described. The joining member of the present invention is formed in a shape corresponding to the shape of a joining hole formed by butting together the notches of two structural materials each having a notch at its end, and fits into the joining hole to join the two structural materials.The joining member is characterized by having an elastic fitting portion that has a diameter larger than the joining hole and has an internal void, and the elastic fitting portion is compressed inward when inserted into the joining hole, and returns to its original shape when fitted, fitting into the joining hole. The joining member has the same structure as that described in the joining structure of the structural material above, and therefore a description thereof will be omitted.

[0036] Hereinafter, first to fifth embodiments of the joining structure for structural materials of the present invention will be specifically explained with reference to the drawings, but the present invention is not limited to these embodiments.

[0037] Here, Fig. 1 is an explanatory diagram of the joining structure of structural materials according to the first embodiment of the present invention, showing the state before two structural materials are joined. Fig. 2 is an explanatory diagram of the joining structure of structural materials according to the first embodiment of the present invention, showing a schematic diagram of the state after two structural materials have been joined. Fig. 3 is a schematic side view of a gourd-shaped joining member of the joining structure of structural materials shown in Fig. 1. Fig. 4 is a schematic cross-sectional view of the gourd-shaped joining member of the joining structure of structural materials shown in Fig. 1.

[0038] 1 and 2, a joining structure 1 for structural materials according to a first embodiment of the present invention comprises a rectangular structural material 10, a rectangular structural material 12, and a gourd-shaped joining member 14. The rectangular structural material 10 and the rectangular structural material 12 are members having similar configurations.

[0039] As shown in Figures 1 and 2, the rectangular structural member 10 is a wooden block approximately 35 mm long, 20 mm wide, and 9.0 mm high, and has a cylindrical cutout 16 approximately 9.0 mm in diameter and 8.5 mm high in the center of one end (the center of the corner between the wood surface and the butt end).

[0040] 1 and 2, the joining structure 1 for structural materials is arranged so that the notch 16 of the rectangular structural material 10 and the notch 18 of the rectangular structural material 12 are butted together to form a joining hole 20. The joining hole 20 is a gourd-shaped hole in a plan view, symmetrical about the butted end side faces of the rectangular structural material 10 and the rectangular structural material 12. The joining hole 20 is formed with a length in the longitudinal direction of 16 mm, a maximum length in the lateral direction of 9.0 mm, a minimum length (the width at the butted end side faces) of 4.6 mm, and a height of 8.5 mm.

[0041] 3, the gourd-shaped joining member 14 is a member formed in a gourd shape in plan view, such that two cylinders are connected together. The gourd-shaped joining member 14 has an elastic fitting portion 22, and a pilot portion 24 and a lid portion 26 respectively above and below the elastic fitting portion 22. The elastic fitting portion 22, the pilot portion 24, and the lid portion 26 are made of plastic such as polylactic acid, and are integrally molded using a 3D printer.

[0042] 3, elastic fitting portion 22 is 17 mm long, 9.5 mm wide, and 2.5 mm high, and has a diameter larger than that of connecting hole 20. Pilot portion 24 is 15 mm long, 8.5 mm wide, and 3.5 mm high, and has a diameter smaller than that of connecting hole 20, and is rounded. Cover portion 26 is 16 mm long, 9.0 mm wide, and 2.5 mm high, and has a diameter large enough to be inserted into connecting hole 20 without any gaps.

[0043] 4, elastic fitting portion 22 has therein ellipsoidal voids 28a and 28b, which are circular in shape with a maximum diameter of about 3.5 mm and a height of about 5.5 mm in a plan view. Voids 28a and 28b are provided at positions a predetermined distance inward from the peripheral wall of elastic fitting portion 22, and are located at positions corresponding to the centers of notch 16 in rectangular structural member 10 and notch 18 in rectangular structural member 12, respectively, in a plan view.

[0044] In the joining structure 1 for structural materials described above, the gourd-shaped joining member 14, which corresponds to the shape of the joining hole 20, is provided with an elastic fitting portion 22 which has a diameter larger than the joining hole 20 and has internal gaps 28a, 28b; the elastic fitting portion 22 is compressed inward when inserted into the joining hole 20, and returns to its original shape when fitted, so that it fits into the joining hole 20; therefore, the rectangular structural material 10 and the rectangular structural material 12 can be easily joined with stable, high strength.

[0045] Next, the joining structures for structural materials according to second to fifth embodiments of the present invention will be described in detail. The second to fifth embodiments differ from the first embodiment in that the shapes of the joining members are different. Furthermore, the two structural materials correspond to the joining members, and their description will be omitted. Furthermore, members having the same configuration as the joining structure 1 for structural materials according to the first embodiment will be assigned the same reference numerals and their description will be omitted.

[0046] Here, Fig. 5 is an explanatory diagram of a round dumbbell-shaped joining member of a joining structure for structural materials according to a second embodiment of the present invention, where (a) is a perspective view, (b) is a side view, (c) is a plan view, and (d) is a schematic cross-sectional view. Fig. 6 is an explanatory diagram of a square dumbbell-shaped joining member of a joining structure for structural materials according to a third embodiment of the present invention, where (a) is a perspective view, (b) is a side view, (c) is a plan view, and (d) is a schematic cross-sectional view. Fig. 7 is an explanatory diagram of a diamond-shaped joining member of a joining structure for structural materials according to a fourth embodiment of the present invention, where (a) is a perspective view, (b) is a side view, (c) is a plan view, and (d) is a schematic cross-sectional view. Fig. 8 is an explanatory diagram of an arrow-shaped joining member of a joining structure for structural materials according to a fifth embodiment of the present invention, where (a) is a perspective view, (b) is a side view, (c) is a plan view, and (d) is a schematic cross-sectional view.

[0047] As shown in Figure 5, the round dumbbell-shaped joint member 30 of the joining structure for structural materials according to the second embodiment of the present invention is a member formed in a round dumbbell shape in plan view, with two cylinders connected by a rectangular member. The round dumbbell-shaped joint member 30 has a pilot portion 34 and a lid portion 36 respectively above and below an elastic fitting portion 32 provided in the center.

[0048] As shown in Figure 6, a rectangular dumbbell-shaped joint member 40 of a joining structure for structural materials according to a third embodiment of the present invention is a member formed in a rectangular dumbbell shape in plan view, with two square prisms connected by a rectangular member. The rectangular dumbbell-shaped joint member 40 has a pilot portion 44 and a lid portion 46 above and below an elastic fitting portion 42 provided in the center.

[0049] 7, a diamond-shaped joint member 50 of a joining structure for structural materials according to a fourth embodiment of the present invention is a member formed in a shape of two connected diamonds in plan view, so that two diamond-shaped pillars are joined together. The diamond-shaped joint member 50 has an elastic fitting portion 52, and has a pilot portion 54 and a lid portion 56 above and below the elastic fitting portion 52, respectively.

[0050] As shown in Fig. 8, the arrow-shaped joint member 60 of the joining structure for structural materials according to the fifth embodiment of the present invention is a member formed in a double-arrow shape in plan view, with two triangular prisms connected by a rectangular member. The arrow-shaped joint member 60 has a pilot portion 64 and a cover portion 66 respectively above and below an elastic fitting portion 62 provided in the center.

[0051] The joining members 30, 40, 50, 60 of the joining structure for timber according to the second to fifth embodiments of the present invention described above are equipped with elastic fitting portions 32, 42, 52, 62 that have a diameter larger than the joining hole 20 and have an internal void 28. The elastic fitting portions 32, 42, 52, 62 are compressed inward when inserted into the joining hole 20 and return to their original shape when fitted, so that they fit into the joining hole 20. Therefore, the joining structure for structural materials of the present invention using the joining members 30, 40, 50, 60 can easily join two structural materials with stable, high strength. Furthermore, the joining structure for structural materials of the present invention, as long as it has the above configuration, can be applied to structural materials that form joining holes of various shapes and joining members that correspond to the joining holes. [Example]

[0052] Specific examples of the present invention will be described below, but the scope of the present invention is not limited to these examples.

[0053] A joining member for a joining structure of structural materials according to the first embodiment of the present invention was manufactured. Specifically, a gourd-shaped joining member was produced using a 3D printer. Polylactic acid was used as the material for the 3D printer. Figure 9 shows photographs of the gourd-shaped joint member produced in the example, where (a) is a diagonal photograph from above, (b) is a side photograph, (c) is a plan photograph, and (d) is a diagonal photograph from below.

[0054] Specifically, the elastic fitting portion of the gourd-shaped joining member produced in the examples had a longitudinal length of 17 mm, a maximum lateral length (diameter of the circular portion) of 9.5 mm, and a height of 2.5 mm. The pilot portion of the joining member had a longitudinal length of 15 mm, a maximum lateral length (diameter of the circular portion) of 8.5 mm, and a height of 3.5 mm. The lid portion of the joining member had a longitudinal length of 16 mm, a maximum lateral length (diameter of the circular portion) of 9.0 mm, and a height of 2.5 mm. The internal ellipsoidal void had a maximum circular diameter of approximately 3.5 mm and a height of approximately 5.5 mm in plan view.

[0055] Using the produced gourd-shaped joint members, a structure having a joint structure of the structural material of the present invention was manufactured. The structural members consisted of four rectangular pillars with triangular pillar-shaped tips. Four cylindrical notches, each 9.0 mm in diameter and 8.5 mm in height, were formed on the left and right slanted sides of the top and bottom surfaces of the triangular pillar-shaped tips.

[0056] The tips of four rectangular pillars (furniture components) were butted together, and the notches of adjacent pillars were positioned to form joint holes. Using eight gourd-shaped joint members manufactured in the example, a cross-shaped decorative structure measuring 360 mm in length, 280 mm in width, and 40 mm in height was produced. It was confirmed that a structure equipped with a joint structure for structural materials using the joint members of the present invention did not shift between the members even when subjected to strong vibrations, and all members were firmly joined. It was found that the joint structure for structural materials of the present invention allows structural materials to be easily joined with stable, high strength. [Industrial Applicability]

[0057] The joining structure for structural materials of the present invention can be used as a joining structure for furniture components and building components, and is therefore industrially useful. [Explanation of symbols]

[0058] 1. Joint structure of structural materials (first embodiment) 10 Rectangular structural material 12 Rectangular structural material 14 Gourd-shaped joint member 16 Notch of rectangular structural member 10 18 Notch of rectangular structural member 12 20 joint hole 22 Elastic fitting part 24 Pilot Division 26 Lid 28 void 30 Round dumbbell-shaped joint member 32 Elastic fitting part 34 Pilot Division 36 Lid 40 Square dumbbell-shaped joint member 42 Elastic fitting part 44 Pilot Division 46 Lid 50 Diamond-shaped joint member 52 Elastic fitting part 54 Pilot Division 56 Lid 60 Arrow-shaped joint member 62 Elastic fitting part 64 Pilot Division 66 Lid

Claims

1. A joining structure for structural materials, in which two structural materials each having a notch at an end are arranged so that the notch portions of the two structural materials butt together to form a joining hole, and a joining member corresponding to the shape of the joining hole is inserted into the joining hole, The joining member has an elastic fitting portion having a diameter larger than that of the joining hole and having a gap therein, the elastic fitting portion being compressed inward when inserted into the joining hole and restored to its original shape when fitted into the joining hole, a pilot portion provided below the elastic fitting portion, having a diameter equal to or smaller than that of the connecting hole, and being inserted into the connecting hole first; a cover portion provided above the elastic fitting portion, having a diameter large enough to be inserted into the joining hole without a gap, and forming the same plane as the upper surfaces of the two structural members; Equipped with A joining structure for structural materials characterized by the above.

2. 2. The joining structure of structural materials according to claim 1, wherein the circumferential length of the elastic fitting portion of the joining member is longer than the circumferential length of the joining hole.

3. 2. The joining structure for structural materials according to claim 1, wherein the joining member is gourd-shaped in plan view.

4. 2. The joining structure for structural materials according to claim 1, wherein the bottom of said joining member is rounded.

5. 2. The joining structure of structural materials according to claim 1, wherein the joining member is made of a plant-derived resin.

6. 6. The joining structure of structural materials according to claim 5, wherein the plant-derived resin is polylactic acid.

7. The joining structure of structural materials according to claim 5, wherein the joining member is a member integrally formed by a 3D printer.

8. A structure comprising the joint structure of structural materials according to claim 1.

9. A joining member that is formed in a shape corresponding to the shape of a joining hole formed by butting together the notched portions of two structural members each having a notched portion at an end thereof, and that fits into the joining hole to join the two structural members, A member comprising an elastic fitting portion having a diameter larger than that of the joining hole and having a void therein, the elastic fitting portion being compressed inward when inserted into the joining hole and restoring to its original shape when fitted into the joining hole, a pilot portion provided below the elastic fitting portion, having a diameter equal to or smaller than that of the connecting hole, and being inserted into the connecting hole first; a cover portion provided above the elastic fitting portion, having a diameter large enough to be inserted into the joining hole without a gap, and forming the same plane as the upper surfaces of the two structural members; Equipped with A joining member characterized by:

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