Joint structure

Abstract

To securely perform locking.SOLUTION: A junction structure connects between a first junction of a first member and a second junction of a second member. The first junction has a first convex part having a first recess lying along a prescribed direction and a second recess lying along an intersecting direction so as to intersect with the prescribed direction and intersecting with the first recess, and a first concave part. The second junction has a second convex part, which fits to the first concave part and has a third recess lying along the prescribed direction and a fourth recess lying along the intersecting direction so as to intersect with the third recess, and a second concave part fitting to the first convex part. The junction structure has a first engaging member, which is inserted into a first hole formed of the first recess and the third recess and prevents the first convex part and the second convex part adjacent to each other from being separated away in the intersecting direction by engaging, and a second engaging member, which is inserted into a second hole formed of the second recess and the fourth recess and prevents the first convex part and the second convex part adjacent to each other from being separated away in the prescribed direction by engaging. The first engaging member comes in contact with the second engaging member.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] As a joining structure for joining wooden members (boards) together, for example, Patent Document 1 discloses a joining structure that uses dovetail joints and wooden plugs (engaging members) to avoid using metal fittings. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-143461 Summary of the Invention [Problem to be solved by the invention]

[0004] When the wooden plug is inserted in only one direction (axial direction), it is possible to prevent it from coming out in the direction perpendicular to the insertion direction, but there is a risk that it will not be possible to prevent it from coming out in the insertion direction.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to realize a joining structure that can reliably prevent disengagement. [Means for solving the problem]

[0006] The main invention for achieving the above object is a joining structure between a first joining portion of a first member and a second joining portion of a second member, wherein the first joining portion has a first convex portion including a first recessed portion along a predetermined direction and a second recessed portion along a cross direction crossing the predetermined direction and intersecting with the first recessed portion, and a first recess; the second joining portion has a second convex portion that fits into the first recessed portion and includes a third recessed portion along the predetermined direction and a fourth recessed portion along the cross direction and intersecting with the third recessed portion; a first engaging member that is inserted into a first hole formed by the first recessed portion and the third recessed portion and prevents adjacent first protrusions and second protrusions from separating in the intersecting direction by engaging with each other; and a second engaging member that is inserted into a second hole formed by the second recessed portion and the fourth recessed portion and prevents adjacent first protrusions and second protrusions from separating in the predetermined direction by engaging with each other, wherein the first engaging member and the second engaging member are in contact with each other.

[0007] Other features of the present invention will become apparent from the description of this specification and the accompanying drawings. [Effects of the Invention]

[0008] According to the present invention, a joining structure that can reliably prevent disengagement can be realized. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic perspective view showing a structure 1 of the present embodiment. [Figure 2] FIG. 2 is an exploded perspective view of FIG. 1. [Figure 3] 2 is a perspective view of a joint portion between a first member 10 and a second member 20. FIG. [Figure 4] FIG. 4 is an exploded perspective view of FIG. 3. [Figure 5] 2 is a perspective view of a joint portion between a first member 10 and a third member 30. FIG. [Figure 6] FIG. 6 is an exploded perspective view of FIG. 5. [Figure 7] 7A to 7C are diagrams showing examples of joining wooden plugs. [Figure 8] FIG. 10 is a schematic perspective view showing a modified structural body 1'. [Figure 9] FIG. 10 is a diagram showing a comparison of performance depending on the cross-sectional shape. DETAILED DESCRIPTION OF THE INVENTION

[0010] At least the following matters will become apparent from this specification and the accompanying drawings.

[0011] A joining structure between a first joining portion of a first member and a second joining portion of a second member, wherein the first joining portion has a first convex portion including a first recessed portion along a predetermined direction and a second recessed portion along a cross direction crossing the predetermined direction and intersecting with the first recessed portion, and a first recessed portion; the second joining portion has a second convex portion that fits with the first recessed portion and includes a third recessed portion along the predetermined direction and a fourth recessed portion along the cross direction and intersecting with the third recessed portion, and a second recessed portion that fits with the first convex portion. a first engaging member having a first recess portion and a second recess portion, the first engaging member being inserted into a first hole formed by the first recess portion and the third recess portion and engaging with the first protrusion portion to prevent the adjacent first protrusion portion and the second protrusion portion from separating in the intersecting direction; and a second engaging member being inserted into a second hole formed by the second recess portion and the fourth recess portion and engaging with the second protrusion portion to prevent the adjacent first protrusion portion and the second protrusion portion from separating in the predetermined direction, wherein the first engaging member and the second engaging member are in contact with each other.

[0012] Such a joining structure can reliably prevent the connector from coming loose.

[0013] In such a joining structure, it is desirable that the contact portions between the first engaging member and the second engaging member are bonded.

[0014] Such a joining structure can prevent the engaging member from falling off.

[0015] In such a joining structure, the first engaging member may have a hole formed in a side surface thereof, and a tip end of the second engaging member may be press-fitted into the hole of the first engaging member.

[0016] Such a joining structure can prevent the engaging member from falling off.

[0017] In such a joining structure, the first engaging member may have a screw hole formed on a side surface, and the second engaging member may have a screw portion at least at its tip that corresponds to the screw hole, and the screw hole of the first engaging member and the screw portion of the second engaging member may be screwed together.

[0018] Such a joining structure can prevent the engaging member from falling off.

[0019] In such a joining structure, it is desirable that the first joining portion has a plurality of alternating first convex portions and a plurality of alternating first concave portions, the second joining portion has a plurality of alternating second convex portions and a plurality of alternating second concave portions, the first concave portion and the second concave portion are formed on both sides of the first convex portion, the third concave portion and the fourth concave portion are formed on both sides of the second convex portion, the first engaging member is inserted into the first hole formed in the adjacent first convex portion and the second convex portion, and the second engaging member is inserted into the second hole formed in the adjacent first convex portion and the second convex portion, respectively.

[0020] Such a joining structure allows for more reliable joining.

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] ===This embodiment=== <About Structure 1> FIG. 1 is a schematic perspective view showing a structure 1 of this embodiment, and FIG. 2 is an exploded perspective view of FIG. 1. FIG. 3 is a perspective view of a joint between a first member 10 and a second member 20, and FIG. 4 is an exploded perspective view of FIG. 3. FIG. 5 is a perspective view of a joint between a first member 10 and a third member 30, and FIG. 6 is an exploded perspective view of FIG. 5. In this embodiment, as shown in the figures, three mutually orthogonal directions (X direction, Y direction, and Z direction) are defined. The Z direction is the vertical direction (up-down direction), with the upper side of the vertical direction being defined as "up" and the lower side of the vertical direction being defined as "down". The X direction and Y direction are horizontal directions.

[0023] The structure 1 of this embodiment has a joining structure for joining plate materials (first member 10, second member 20, and third member 30) together. Wooden plugs 40, 50 are used at the joints between the members. In this embodiment, the structure 1 is a wooden pillar, and is erected along the Z direction (vertical direction).

[0024] <Regarding the first member 10> The first member 10 is a substantially rectangular wooden board (for example, CLT (Cross Laminated Timber)) and is arranged so that its length is along the Z direction, its width is along the X direction, and its thickness is along the Y direction. As shown in Fig. 2, the first member 10 includes a main body portion 10a that constitutes the main body, and a joint portion 10b for joining to other members (here, the second member 20 and the third member 30).

[0025] A pair of joints 10b (corresponding to first joints) are provided on both side surfaces of the main body 10a in the width direction (X direction). Each of the pair of joints 10b has a plurality of protrusions 11 and a plurality of recesses 12. The protrusions 11 and recesses 12 are arranged alternately in the Z direction.

[0026] The protrusion 11 (corresponding to the first protrusion) protrudes outward (outward in the X direction) from the main body 10a. The protrusion 11 has a substantially rectangular shape in a plan view (viewed in the Y direction). As shown in FIG. 2 and other figures, the protrusion 11 has a recess 13 and a recess 14 on both sides in the Z direction.

[0027] The recessed portion 13 (corresponding to the first recessed portion) is provided along the thickness direction (corresponding to a predetermined direction: here, the Y direction) of the first member 10 (protrusion 11). The recessed portion 13 is formed by cutting out the protrusion 11 in a semicircular shape, and is therefore recessed in a semicircular shape into the inside of the protrusion 11. In the protrusion 11, the recessed portion 13 is provided continuously from one end to the other end in the Y direction.

[0028] The recessed portion 14 is provided along the width direction (corresponding to the cross direction: here, the X direction) of the first member 10. The recessed portion 14 also intersects with the recessed portion 13. The recessed portion 14 is also formed by cutting out the protruding portion 11 in a semicircular shape, and therefore is recessed inward of the protruding portion 11 in a semicircular shape.

[0029] The recesses 12 (corresponding to first recesses) are spaces provided between adjacent protrusions 11, and have substantially the same shape as the protrusions 11 (substantially rectangular in plan view).

[0030] <Regarding the second member 20> The second member 20 is a plate material similar to the first member 10, and is arranged so that its longitudinal direction is along the Z direction, its width direction is along the Y direction, and its thickness direction is along the X direction. That is, the second member 20 is at an angle of 90 degrees with respect to the first member 10 (the angle formed between the second member 20 and the first member 10 is a right angle). Also, as shown in FIG. 2, the second member 20 includes a main body portion 20a that constitutes the main body, and a joint portion 20b for joining to another member (here, the first member 10).

[0031] The joint portion 20b (corresponding to the second joint portion) is provided on one side surface of the main body portion 20a in the width direction (Y direction). The joint portion 20b has a plurality of protrusions 21 and a plurality of recesses 22. The protrusions 21 and recesses 22 are arranged alternately in the Z direction.

[0032] The protrusion 21 (corresponding to the second protrusion) protrudes outward (toward the Y direction) from the main body 20a. The protrusion 21 has a substantially rectangular shape in a plan view (as viewed in the X direction). As shown in Figures 2 and 4, the protrusion 21 has a recess 23 and a recess 24 on both sides in the Z direction.

[0033] The recessed portion 23 (corresponding to the third recessed portion) is provided along the width direction (here, the Y direction) of the second member 20. The recessed portion 23 is formed by cutting out the protruding portion 21 in a semicircular shape, and is therefore recessed in a semicircular shape toward the inside of the protruding portion 21. In the protruding portion 21, the recessed portion 23 is provided continuously from one end to the other end in the Y direction.

[0034] The recessed portion 24 (corresponding to the fourth recessed portion) is provided along the thickness direction (here, the X direction) of the second member 20. The recessed portion 24 also intersects with the recessed portion 23. The recessed portion 24 is also formed by cutting out the protruding portion 21 in a semicircular shape, and is therefore recessed in a semicircular shape into the inside of the protruding portion 21. The recessed portion 24 is provided so as to face the recessed portion 14 of the first member 10.

[0035] The recessed portion 22 (corresponding to the second recessed portion) is a space provided between adjacent protruding portions 21, and has substantially the same shape as the protruding portions 21 (substantially rectangular in plan view).

[0036] <Regarding the third member 30> The third member 30 is a plate material similar to the first member 10 and the second member 20, and is arranged so that its longitudinal direction is along the Z direction, its width direction is along the Y direction, and its thickness direction is along the X direction. That is, the third member 30 is parallel to the second member 20 and is at an angle of 90 degrees with respect to the first member 10 (the angle formed between the third member 30 and the first member 10 is a right angle). Also, as shown in FIG. 2, the third member 30 includes a main body portion 30a that constitutes the main body, and a joint portion 30b for joining to another member (here, the first member 10).

[0037] The joint portion 30b is provided on one side surface of the main body portion 30a in the width direction (Y direction). The joint portion 30b has a plurality of protrusions 31 and a plurality of recesses 32. The protrusions 31 and recesses 32 are arranged alternately in the Z direction.

[0038] The protrusion 31 protrudes outward (toward the Y direction) from the main body 30a. The protrusion 31 has a substantially rectangular shape in a plan view (when viewed in the X direction). As shown in Figures 2 and 6, the protrusion 31 has a recess 33 and a recess 34 on both sides in the Z direction.

[0039] The recessed portion 33 is provided along the width direction (here, the Y direction) of the third member 30. The recessed portion 33 is formed by cutting out a semicircular shape in the protruding portion 31, and therefore is recessed in a semicircular shape inside the protruding portion 31. In the protruding portion 31, the recessed portion 33 is provided continuously from one end to the other end in the Y direction.

[0040] The recessed portion 34 is provided along the thickness direction (here, the X direction) of the third member 30. The recessed portion 34 also intersects with the recessed portion 33. The recessed portion 34 is also formed by cutting out the protruding portion 31 in a semicircular shape, and therefore is recessed inward of the protruding portion 31 in a semicircular shape.

[0041] The recessed portions 32 are spaces provided between adjacent protruding portions 31, and have substantially the same shape as the protruding portions 31 (substantially rectangular in plan view).

[0042] <About wooden plugs 40 and 50> The wooden plug 40 is inserted (placed) along the Y direction in a hole H1 (see FIG. 3) formed by the recessed portion 13 of the first member 10 and the recessed portion 23 of the second member 20, and prevents separation (separation in the X direction) between adjacent protrusions 11 and 21 by engaging with each other. The hole H1 corresponds to the first hole, and the wooden plug 40 inserted into the hole H1 corresponds to the first engaging member.

[0043] In addition, the wooden plug 40 is inserted along the Y direction into the hole H3 (see Figure 5) formed by the recessed portion 13 of the first member 10 and the recessed portion 33 of the third member 30, and prevents separation (separation in the X direction) between adjacent protrusions 11 and 31 by engagement.

[0044] Hole H1 is a circular hole formed by recesses 13 and 23, and hole H3 is a circular hole (having the same shape as hole H1) formed by recesses 13 and 33. Therefore, wooden plug 40 is a member with a circular (cylindrical) cross section so that it can be properly fitted into holes H1 and H3.

[0045] The wooden plug 50 is inserted along the X direction into a hole H2 (see FIG. 3) formed by the recess 14 of the first member 10 and the recess 24 of the second member 20, and prevents separation (separation in the Y direction) between adjacent protrusions 11 and 21 by engaging with each other. Note that the hole H2 corresponds to the second hole, and the wooden plug 50 inserted into the hole H2 corresponds to the second engaging member.

[0046] In addition, the wooden plug 50 is inserted along the X direction into the hole H4 (see Figure 5) formed by the recessed portion 14 of the first member 10 and the recessed portion 34 of the third member 30, and prevents separation (separation in the Y direction) between adjacent protrusions 11 and 31 by engagement.

[0047] Hole H2 is a circular hole formed by recesses 14 and 24, and hole H4 is a circular hole (having the same shape as hole H2) formed by recesses 14 and 34. The lengths (lengths in the X direction) of holes H2 and H4 are shorter than the lengths (lengths in the Y direction) of holes H1 and H3. For this reason, wooden plug 50 is shorter than wooden plug 40 and has a circular (cylindrical) cross section so that it can be properly fitted into holes H2 and H4.

[0048] As described above, recess 14 intersects with recess 13, and recess 24 intersects with recess 23. Therefore, hole H2 formed by recess 14 and recess 24 communicates with hole H1 formed by recess 13 and recess 23. This allows wooden plug 40 inserted into hole H1 to come into contact with wooden plug 50 inserted into hole H2.

[0049] Furthermore, recess 14 intersects with recess 13, and recess 34 intersects with recess 33. Therefore, hole H4 formed by recess 14 and recess 34 communicates with hole H3 formed by recess 13 and recess 33. This allows wooden plug 40 inserted into hole H3 to come into contact with wooden plug 50 inserted into hole H4.

[0050] <Method of forming the joint> Next, an example of a method for forming the joint will be described. Note that here, a method for forming the joint 10b of the first member 10 will be described.

[0051] First, the first member 10 is prepared before processing (a state in which the joint portion 10b is not formed), and circular holes are accurately drilled in advance using a drill or the like at predetermined positions in the longitudinal direction (positions corresponding to the recesses 13 and 14). Specifically, for the recess 13, a hole (a through hole in this embodiment) is drilled along the thickness direction of the first member 10, and for the recess 14, a hole is drilled (at the above-mentioned predetermined position) along the width direction so as to intersect with the hole.

[0052] Then, an automatic processing machine or the like is used to process the surface into irregularities, and the area other than the protrusion 11 (i.e., the area of ​​the recess 12) is cut away. At this time, the cut is made across the hole made by the drill or the like, leaving half (semicircle) of the protrusion. This forms the protrusion 11 with semicircular recesses (recesses 13, 14) in two directions, and the joint 10b with the recess 12.

[0053] The joining portion 20b of the second member 20 and the joining portion 30b of the third member are formed in the same manner, and therefore the explanation thereof will be omitted.

[0054] In this embodiment, the angles between the members (plates) are right angles, so there is no need to perform oblique processing, etc. This makes it easy to process and join the members (joints).

[0055] <About joining each component> 4, one joint 10b of the first member 10 is mated with one joint 20b of the second member 20 while the first member 10 and the second member 20 are at a 90-degree angle. That is, the convex portion 11 of the joint 10b is mated with the concave portion 22 of the joint 20b, and the convex portion 21 of the joint 20b is mated with the concave portion 12 of the joint 10b.

[0056] At this time, the recessed portion 13 of the protrusion 11 and the recessed portion 23 of the protrusion 21 form a circular hole H1 along the thickness direction (here, the Y direction) of the first member 10. Furthermore, the recessed portion 14 of the protrusion 11 and the recessed portion 24 of the protrusion 21 form a circular hole H2 along the width direction (here, the X direction) of the first member 10, which is in communication with the hole H1.

[0057] Then, wooden plugs 40 are inserted into the formed hole H1. Furthermore, wooden plugs 50 are inserted into hole H2 and brought into contact with wooden plugs 40. Similarly, wooden plugs 40 and 50 are inserted (placed) into all holes H1 and H2 of joints 10b and 20b. This joins joints 10b and 20b.

[0058] Next, the first member 10 and the third member 30 are joined in the same manner. That is, as shown in Fig. 6, the other joint portion 10b of the first member 10 is mated with the joint portion 30b of the third member 30 while the first member 10 and the third member 30 form a 90-degree angle. That is, the convex portion 11 of the joint portion 10b is mated with the concave portion 32 of the joint portion 30b, and the convex portion 31 of the joint portion 30b is mated with the concave portion 12 of the joint portion 10b.

[0059] At this time, the recessed portion 13 of the protrusion 11 and the recessed portion 33 of the protrusion 31 form a circular hole H3 along the thickness direction (here, the Y direction) of the first member 10. Furthermore, the recessed portion 14 of the protrusion 11 and the recessed portion 34 of the protrusion 31 form a circular hole H4 along the width direction (here, the X direction) of the first member 10, which is in communication with the hole H3.

[0060] Then, wooden plugs 40 are inserted into the formed hole H3. Furthermore, wooden plugs 50 are inserted into hole H4 and brought into contact with wooden plugs 40. Similarly, wooden plugs 40 and 50 are inserted (placed) into all holes H and H4 of joints 10b and 30b. This joins joints 10b and 30b.

[0061] As a result, the first member 10, the second member 20, the third member 30, the wooden plug 40, and the wooden plug 50 are integrated together to form the structure 1.

[0062] Here, if only one of the wooden plugs 40 and 50 is provided at one joint (for example, the joint between the first member 10 and the second member 20) (if only one of the holes H1 and H2 is formed), there is a risk that the members will not be properly prevented from coming loose.

[0063] Specifically, if only a hole H1 is formed at the joint between the first member 10 and the second member 20, and the wooden plug 40 is inserted (placed) in the hole H1 along the Y direction, the first member 10 (protrusion 11) and the second member 20 (protrusion 21) will not easily come off in the X direction. However, the wooden plug 40 will easily come off (there is a risk of it coming off) in the axial direction (Y direction) of the wooden plug. In this way, although the wooden plug can be properly prevented from coming off in the direction perpendicular to the insertion direction (axial direction of the wooden plug), there is a risk that the wooden plug will not be properly prevented from coming off in the insertion direction.

[0064] In contrast to this, in this embodiment, a hole H1 (H3) along the Y direction and a hole H2 (H4) along the X direction are provided at one joint, and the wooden plugs 40 and 50 are inserted (placed) respectively so that the wooden plugs 40 and 50 come into contact with each other. This allows proper prevention of slippage in both the X direction and the Y direction, ensuring reliable prevention of slippage.

[0065] If the wooden plugs 40 and 50 are joined together, they can be more reliably prevented from coming loose.

[0066] 7A to 7C are diagrams showing examples of joining wooden plugs. Note that in Fig. 7A to 7C, illustrations of anything other than the wooden plugs are omitted (only the wooden plugs are shown).

[0067] In Fig. 7A, the contact portions of the wooden plugs 40 and 50 are bonded with adhesive or the like. This makes it possible to more reliably prevent the wooden plugs from coming off. It also makes it possible to prevent the wooden plugs from falling off.

[0068] In Figure 7B, wooden plugs 40' and 50' are used. Wooden plug 40' has a larger diameter than wooden plug 50', and has a hole 41 formed on its side that is slightly smaller in diameter than wooden plug 50'. Wooden plug 50' (tip portion) is press-fitted into this hole 41 using a hammer or the like. This joins wooden plug 40' and wooden plug 50'.

[0069] Also, in FIG. 7C, wooden plugs 40" and 50" are used. Wooden plug 40" has a larger diameter than wooden plug 50", and has a screw hole 42 (female screw) formed on its side. Wooden plug 50" also has a screw portion 52 (male screw) formed on its tip that corresponds to the screw hole 42 of wooden plug 40". Wooden plugs 40" and 50" are joined by screwing this screw portion 52 of wooden plug 50" into the screw hole 42 of wooden plug 40". In this embodiment, the screw portion 52 is formed only on the tip of wooden plug 50', but this is not limited thereto and may be provided, for example, over the entire length of wooden plug 50'.

[0070] <Modification> 8 is a schematic perspective view showing a modified structure 1'. The structure 1' includes a first member 10, a second member 20', and a third member 30'. In this modified structure, two first members 10 are used.

[0071] The second member 20' has (a pair of) joints 20b with the first member 10 (joints 10b) on both sides in the width direction (Y direction).

[0072] Similarly, the third member 30' also has (a pair of) joints 30b with the first member 10 (joints 10b) on both sides in the width direction (Y direction).

[0073] Then, the structure 1' is formed by joining two first members 10, a second member 20', and a third member 30' in a rectangular shape as shown in the figure. Note that the joining of each member (joining structure) is the same as in the above-mentioned embodiment, so a description thereof will be omitted. The structure 1' of this modified example is a structure with a closed cross section in which a hollow portion S is formed.

[0074] <About cross-sectional performance> Figure 9 shows a comparison of performance depending on the cross-sectional shape. The dimensions (numbers) shown in the figure are in mm.

[0075] Here, the cross-sectional area (A) and the moment of inertia (I) are calculated for a comparative example (full cross section) in which the rectangular cross section is made entirely of wood, the present embodiment (Structure 1) with a U-shaped cross section (open cross section), and a modified example (Structure 1') with a square-shaped cross section (closed cross section). For Structure 1, the moment of inertia (Ix) in the X-axis direction and the moment of inertia (Iy) in the Y-axis direction are also calculated.

[0076] The numbers in parentheses below the cross-sectional area (A) and second moment of area (I) in the figure indicate the ratio to the comparative example (full cross section) (values ​​when the comparative example is set to 1.0).

[0077] In this embodiment (structure 1), the cross-sectional area (A) is less than half (44%) of that of the comparative example, while the second moment of area (Ix, Iy) is 60 to 70% of that of the comparative example. In other words, even if the cross-sectional area is reduced to less than half, the second moment of area is not as small as the cross-sectional area (a reduction of about 25 to 40%). Therefore, it can be said that high rigidity and strength can be obtained with a small cross-sectional area.

[0078] Furthermore, in the modified example (Structure 1'), the cross-sectional area (A) is about half (55%) of that of the comparative example, while the second moment of area (I) is 80% of that of the comparative example. In other words, even if the cross-sectional area is reduced by about half, the second moment of area is only reduced by 20%. Therefore, the rigidity and strength can be further increased.

[0079] In this way, this embodiment and its modifications can realize a highly rigid and strong structure while reducing the amount of wood used. In addition, since processing can be done using automatic processing machines, it is easy to install, is less expensive than joint structures using metal fittings and adhesives, and there is less risk of deterioration.

[0080] ===Other embodiments=== The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

[0081] In the above-described embodiment, the structure 1 (and structure 1') is a pillar, but this is not limiting. For example, it may be a beam. In other words, the Z direction may be horizontal (the X or Y direction may be vertical). In this case, however, if the wooden plug (wooden plug 40 or wooden plug 50) is placed on the lower side (facing downward) in the vertical direction, there is a risk that the wooden plug may fall out. Therefore, in this case, it is desirable to join the wooden plug 40 and the wooden plug 50 as shown in Figures 7A to 7C. This will prevent the wooden plug from falling out.

[0082] In the above-described embodiment, the wooden plugs 40, 50 (and holes H1 to H4) have a circular cross section, but this is not limited to this. For example, the cross section may be rectangular (a rectangle with adjacent sides of different lengths) or square.

[0083] Furthermore, in the above-described embodiment, the angle between the second member 20 and the first member 10 and the angle between the third member 30 and the first member 10 were both right angles (the second member 20 and the third member 30 were joined at a 90-degree angle to the first member 10), but this is not limited to this.

[0084] For example, the angle between the second member 20 and the first member 10 and the angle between the third member 30 and the first member 10 may both be acute angles (angles greater than 0 degrees and less than 90 degrees). In this case, the ends of each member may be beveled, and similar uneven joints may be formed on the end of the second member 20 opposite to joint 20b and the end of the third member 30 opposite to joint 30b, and these ends may be joined together to form a triangular prism with a triangular (closed) cross section and a hollow portion. In this case, a highly rigid and strong structure can be achieved while reducing the amount of wood used.

[0085] Furthermore, the angle between the second member 20 and the first member 10 and the angle between the third member 30 and the first member 10 may both be obtuse angles (angles greater than 90 degrees and less than 180 degrees). In this case, too, the rigidity and strength can be increased compared to when there is no angle.

[0086] Furthermore, in the above-described embodiment, three members (first member 10, second member 20, and third member 30) are joined together, but this is not limiting and two members may be joined together. For example, the joining structure of this embodiment may be applied to a joint between a floor and a wall. In this case, the joint 10b of the first member 10 may be provided on one side in the width direction (it does not have to be a pair). [Explanation of symbols]

[0087] 1 structure 10 First member 10a Main body 10b Joint (1st joint) 11 Convex part (first convex part) 12 Recess (first recess) 13 Recessed portion (first recessed portion) 14 Recessed portion (second recessed portion) 20 Second member 20a Main body 20b Joint (2nd joint) 21 Convex part (second convex part) 22 Recess (second recess) 23 Recessed portion (third recessed portion) 24 recessed portion (fourth recessed portion) 30 Third member 30a Main body 30b joint 31 Convex part 32 recess 33 Recess 34 Recess 40 Wooden plug (first engaging member) 41 holes 42 screw holes 50 wooden plug (second engaging member) 52 Screw part H1 hole (first hole) H2 hole (2nd hole) H3 hole H4 hole S Hollow part

Claims

1. A joining structure between a first joining portion of a first member and a second joining portion of a second member, The first joint portion is a first protrusion including a first recessed portion along a predetermined direction and a second recessed portion along a cross direction crossing the predetermined direction and intersecting with the first recessed portion; A first recess; and The second joint portion is a second protrusion including a third recessed portion that fits into the first recessed portion and is aligned with the predetermined direction, and a fourth recessed portion that is aligned with the intersecting direction and intersects with the third recessed portion; a second recess that fits into the first protrusion; and a first engagement member that is inserted into a first hole formed by the first recessed portion and the third recessed portion and that engages with the first protruding portion and the second protruding portion to prevent the adjacent first protruding portion and the adjacent second protruding portion from separating in the intersecting direction; a second engagement member that is inserted into a second hole formed by the second recessed portion and the fourth recessed portion and that engages with the first protrusion and the second protrusion to prevent the adjacent first protrusion and the second protrusion from separating in the predetermined direction; wherein the first engagement member and the second engagement member are in contact with each other. A joining structure characterized by:

2. The joining structure according to claim 1, a contact portion between the first engaging member and the second engaging member being bonded; A joining structure characterized by:

3. The joining structure according to claim 1, The first engagement member has a hole formed in a side surface, a tip end of the second engaging member is press-fitted into the hole of the first engaging member; A joining structure characterized by:

4. The joining structure according to claim 1, The first engagement member has a screw hole formed on a side surface thereof, the second engaging member has a threaded portion at least at a tip end thereof that corresponds to the threaded hole, The screw hole of the first engagement member and the screw portion of the second engagement member are threadedly engaged with each other. A joining structure characterized by:

5. The joining structure according to any one of claims 1 to 4, the first joint portion has a plurality of first protrusions and a plurality of first recesses alternately arranged, the second joint portion has a plurality of second protrusions and a plurality of second recesses alternately arranged, the first recessed portion and the second recessed portion are formed on both sides of the first protrusion, the third recessed portion and the fourth recessed portion are formed on both sides of the second protrusion, the first engagement members are inserted into the first holes formed in the first protrusion and the second protrusion, respectively, which are adjacent to each other; the second engagement members are inserted into the second holes formed in the first and second protrusions, respectively, adjacent to each other; A joining structure characterized by:

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