Joining structure of wooden members

Abstract

To provide a joint structure for wooden members which can strongly join wooden members while having a simple structure.SOLUTION: A joint structure 1 for wooden members joins a plurality of timbers 10A and 10B. Through holes 12 are formed in each of the timbers 10A and 10B, and steel plates 20 formed with the through holes 22 are mounted on side faces 11A and 11B of the respective timbers 10A and 10B. The plurality of timbers 10A and 10B are arranged so that the steel plates 20 are brought into contact with the plurality of timbers 10A and 10B, and are fixed with a bolt 40 inserted into the through holes 12 of the timbers 10A and 10B and the through holes 22 of the steel plate 20.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a joining structure of wooden members for joining a plurality of wooden members to each other.

Background Art

[0002] Conventionally, joining structures of wooden members have been proposed (see Patent Documents 1 to 3). Patent Document 1 shows a joining structure between a base and a column. On the upper surface of the base, a joining metal fitting is fixed with screws, and this joining metal fitting is accommodated in a receiving portion on the lower surface of the column. Further, a drift pin penetrates through the pin hole of the column and the joining metal fitting, and a liquid curing agent is injected into the gap in the receiving portion.

[0003] Patent Document 2 shows a metal plate connector joining structure in which a metal plate connector having a plurality of claw portions formed by raising a plurality of predetermined portions of a metal plate is installed across the joining portion between plate materials to join the plate materials to each other. The claw portions are press-fitted in the vicinity of the joining portion of the plate materials, and the metal plate connector is adhered to the plate materials with an adhesive. Patent Document 3 shows a joining structure of wooden members in which a square rod and a timber, which are wooden reinforcing members, are provided at an inner corner portion where a column and a beam are joined. A plurality of wooden dowels penetrate through the joining portion between the column and the beam and the square rod so as to penetrate the square rod fitted to the column or the beam.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention aims to provide a joining structure for wooden members that is simple in structure yet capable of firmly joining wooden members together. [Means for solving the problem]

[0006] The wood member joining structure of the first invention (for example, wood member joining structure 1 described later) is a wood member joining structure for joining a plurality of wood members (for example, wood 10A to 10C described later) to each other, wherein each wood member has a through hole (for example, a through hole 12 described later), and a steel plate (for example, a steel plate 20 described later) with a through hole (for example, a through hole 22 described later) is attached to the outer surface of each wood member (for example, the side surfaces 11A, 11B, and the bottom surface 11C of the recess described later), and the plurality of wood members are arranged so that the steel plates abut each other and are fixed together with bolts (for example, bolts 40 described later) inserted through the through holes in the wood members and the steel plates.

[0007] According to this invention, steel plates are fixed to the surfaces of multiple wooden members, and the wooden members are arranged so that the steel plates abut each other, and then fixed with bolts. Therefore, the tightening force introduced into the bolts acts planarly on the wooden members via the steel plates, preventing the bolts from locally sinking into the wooden members. Furthermore, the planar action of the tightening force introduced into the bolts on the wooden members via the steel plates increases the bearing rigidity and splitting resistance of the wooden members. Thus, the joint structure for wooden members of this invention increases the rigidity and strength of the joints between the wooden members, allowing for a strong joint between wooden members despite its simple structure.

[0008] The joint structure for wooden members of the second invention is characterized in that the wooden member and the steel plate are fixed together by at least one of a rod-shaped fastener (for example, a screw 21 described later) and an adhesive.

[0009] According to this invention, when a steel plate is fixed to a wooden member using a fastener, the shear resistance cross-sectional area increases due to the fastener embedded in the wooden member. This increases the shear rigidity and splitting strength of the wooden member, thereby increasing the joint strength between the wooden members. Furthermore, when steel plates are fixed to wooden members with adhesive, the shear deformation along the joint surfaces between the wooden members is further suppressed by the steel plates fixed with adhesive, thereby increasing the joint strength and shear rigidity between the wooden members.

[0010] The third invention relates to a joint structure for wooden members, characterized in that the end face of the rod-shaped fastener is substantially flush with the surface of the steel plate.

[0011] According to this invention, since the end face of the fastener driven into the steel plate is made substantially flush with the surface of the steel plate, the steel plates of the wooden members come into contact with each other without any gaps, and thus a secure bond can be achieved at the contact surface. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a joining structure for wooden members that is simple in structure yet capable of firmly joining wooden members together. [Brief explanation of the drawing]

[0013] [Figure 1] This is a side view of a wooden bridge to which the joint structure for wooden members according to the first embodiment of the present invention is applied. [Figure 2] This is an AA cross-section of the wooden bridge. [Figure 3] This is a schematic cross-sectional view showing the joint structure of two wooden members in a wooden bridge. [Figure 4] These are a plan view and a cross-sectional view of a steel plate (with four screw holes) used in the joint structure of a wooden member according to the first embodiment. [Figure 5] These are a plan view and a cross-sectional view of a steel plate (with eight screw holes) used in a joint structure for wooden members according to the first embodiment. [Figure 6] This figure shows the deformation of wood when tensile force is applied to a conventional wood-based joint structure. [Figure 7] It is a diagram showing the flow of force when a horizontal force (shearing force) acts on the joining structure of the xylem member of the first embodiment. [Figure 8] It is a cross-sectional view of the joining structure of the xylem member according to the second embodiment of the present invention. [Figure 9] It is a diagram showing a list of test specimens used in the loading test. [Figure 10] It is a diagram showing the screws used for the test specimens. [Figure 11] It is a diagram showing the steel plate (Type A) used for the test specimens. [Figure 12] It is a diagram showing the steel plate (Type B) used for the test specimens. <00资源不足无法翻译,请补充完整内容0>It is a diagram showing a method of applying force to Test Specimens No. 1 to No. 7 in which the joint direction is the fiber direction. [Figure 14] It is a diagram showing a method of applying force to Test Specimens No. 8 and No. 9 in which the joint direction is the orthogonal direction. [Figure 15] It is a diagram showing the results of the loading test for Test Specimens No. 1 to No. 7. [Figure 16] It is a diagram showing the results of the loading test for Test Specimens No. 8 and No. 9.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described based on the drawings. In the description of the following embodiments, the same reference numerals are assigned to the same constituent elements, and the description thereof is omitted or simplified. 〔First Embodiment〕 FIG. 1 is a side view of a wooden bridge 1 to which the joining structure of the xylem member according to the first embodiment of the present invention is applied. FIG. 2 is a cross-sectional view taken along line A-A of the wooden bridge 1. The wooden bridge​​​Figure 3 is a schematic cross-sectional view showing the joint structure of two wooden members, timbers 10A and 10B, in the wooden bridge 1. The wood pieces 10A and 10B are members with a rectangular cross-section and a predetermined length. Hereinafter, the two back-to-back sides of each wood piece 10A and 10B will be referred to as side 11A and side 11B. The wood pieces 10A and 10B have through holes 12 formed from side 11A to side 11B. A steel plate 20 is attached to the side surface 11A of the wood pieces 10A and 10B with screws 21, which act as rod-shaped fasteners. The base end face of the screws 21 is substantially flush with the surface of the steel plate 20. Through holes 22 are formed in the steel plate 20, which communicate with the through holes 12 in the wood pieces 10A and 10B. In addition, as shown in Figures 4 and 5, four or eight screw holes 23 for inserting the screws 21 are formed at equal intervals around the through holes 22 in the steel plate 20.

[0016] The wooden pieces 10A and 10B are arranged so that the steel plates 20 are in contact with each other, and bearing plates 30 are placed on the sides 11B of the wooden pieces 10A and 10B. The bearing plates 30 have through holes 31 that communicate with the through holes 12 in the wooden pieces 10A and 10B. The wooden pieces 10A and 10B are fixed to each other by inserting bolts 40 through the through holes 31 in the bearing plate 30, the through holes 12 in the wooden pieces 10A and 10B, and the through holes 22 in the steel plate 20, and then tightening nuts 41 onto these bolts 40.

[0017] Conventionally, as shown in Figure 6, steel plates are not provided on the sides of the wood pieces 110A and 110B. In this case, when a shear force P (indicated by the white arrow in Figure 6) acts on the wood pieces 110A and 110B, the inner wall surface of the through-hole 112 in the wood pieces 110A and 110B is pushed by the bolts 140 that join the wood pieces 110A and 110B together, causing bearing deformation in which the bolts 140 locally sink into the wood pieces 110A and 110B, as shown by the diagonal lines in Figure 6. In contrast, in this invention, a steel plate 20 is provided on the side surface 11A of the wood 10A and 10B. Therefore, when a shear force P (shown by a white arrow in Figure 3) of unidirectional shear acts on the wood 10A and 10B, as shown in Figure 7, the bolt 40 joining the wood 10A and 10B presses against the inner wall surface of the through hole 22 in the steel plate 20 with a pressing force P1. As a result, this pressing force P1 causes a shear force P2 to act planarly on the joint surface S between the steel plate 20 and the wood 10A and 10B, thus preventing the bolt 40 from locally sinking into the wood 10A and 10B.

[0018] This embodiment provides the following effects. (1) Steel plates 20 are fixed to the sides 11A of multiple pieces of wood 10A and 10B, and these pieces of wood 10A and 10B are positioned so that the steel plates 20 touch each other, and the pieces of wood 10A and 10B are fixed to each other with bolts 40 and nuts 41. As a result, the tightening force introduced to the bolts 40 acts planarly on the pieces of wood 10A and 10B via the steel plates 20, which prevents the bolts 40 from locally sinking into the pieces of wood 10A and 10B. In addition, as the tightening force introduced to the bolts 40 acts planarly on the pieces of wood 10A and 10B via the steel plates 20, the bearing rigidity and splitting resistance of the pieces of wood 10A and 10B are increased. As a result, the joint structure for wood members of the present invention increases the rigidity and strength of the joint between the pieces of wood 10A and 10B, so that the pieces of wood 10A and 10B can be firmly joined to each other despite the simple structure. Furthermore, the stiffening effect of the steel plate 20 can be adjusted by changing the bonding area between the side surfaces 11A of the wood 10A and 10B and the steel plate 20, as well as by changing the number of screws 21 driven from the steel plate 20 into the wood 10A and 10B. In addition, the rigidity and load-bearing capacity of the joints between the wood members 10A and 10B can be adjusted.

[0019] (2) Since the steel plate 20 is fixed to the wood 10A and 10B with screws 21, the shear resistance cross-sectional area increases due to the screws 21 driven into the wood 10A and 10B, which increases the shear rigidity and splitting strength of the wood 10A and 10B, and thus the joint strength between the wood 10A and 10B can be increased. (3) Since the base end surface of the screw 21 driven into the steel plate 20 is made substantially flush with the surface of the steel plate 20, the steel plates 20 of the wood 10A and 10B can be joined together without gaps and reliably made to make surface contact.

[0020] (4) In this embodiment, recesses 13 (see Figure 8) for accommodating the steel plates 20 are not countersunk in the side surfaces 11A of the wood pieces 10A and 10B, and the wood pieces 10A and 10B are arranged so that the steel plates 20 come into contact with each other. Therefore, the opposing wood pieces 10A and 10B do not come into direct contact with each other, and the steel plates 20 are interposed between the wood pieces 10A and 10B. As a result, even when the joint structure of the wood members of this embodiment is installed outdoors, rainwater will not remain at the joint between the wood pieces 10A and 10B. In addition, since recesses are not countersunk in the side surfaces 11A of the wood pieces 10A and 10B, the penetration of rainwater into the interior of the wood pieces 10A and 10B is reduced. Therefore, the durability of the joint between the wood pieces 10A and 10B can be increased.

[0021] [Second Embodiment] Figure 8 is a cross-sectional view of a wood-based member joining structure 1A according to a second embodiment of the present invention. This embodiment involves joining together three pieces of wood 10A, 10B, and 10C. The wood 10C is a member with a rectangular cross-section and a predetermined length. A through hole 12 is formed in the wood 10C, extending from side surface 11A to side surface 11B. A recess 13 is formed on side surfaces 11A and 11B of the wood 10C, at the end of the through hole 12. A steel plate 20 is housed in a recess 13 of the wood 10C and secured with screws 21. As a result, the surface of the steel plate 20 is substantially flush with the side surface 11A of the wood 10C. A through hole 22 is formed in the steel plate 20, which communicates with the through hole 12 of the wood 10C.

[0022] A recess 13 is formed on the side surface 11A of the wood 10A and 10B, at the end of the through hole 12, and the steel plate 20 is housed in this recess 13. As a result, the steel plate 20 is positioned on the bottom surface 11C of the recess 13, and the surface of the steel plate 20 is flush with the side surface 11A of the wood 10A and 10B. A recess 14 is formed at the end of the through hole 12 on the side surface 11B of the wood pieces 10A and 10B, where the bearing plate 30 is placed.

[0023] The wood pieces 10A and 10B are arranged with wood piece 10C in between, so that the steel plates 20 of wood pieces 10A, 10B, and 10C are in contact with each other. Furthermore, a bearing plate 30 is placed in the recess 14 on the side surface 11B of wood pieces 10A and 10B. The bearing plate 30 has through holes 31 that communicate with the through holes 12 of wood pieces 10A and 10B. The pieces of wood 10A to 10C are fixed to each other by inserting bolts 40 through the through holes 31 in the bearing plate 30, the through holes 12 in the pieces of wood 10A to 10C, and the through holes 22 in the steel plate 20, and then tightening nuts 41 onto these bolts 40. In this embodiment, as shown in Figure 8, a two-sided shear force P (indicated by the white arrow in Figure 8) acts. According to this embodiment, the same effects as those described in (1) to (3) above are obtained.

[0024] [Examples] As shown in Figure 9, nine test specimens, No. 1 to No. 9, were fabricated, and a loading experiment was conducted in which a vertical load P was applied to measure the relative displacement δ between the pieces of wood. Test specimen No. 1 is a comparative example representative of the conventional method, while test specimens No. 2 to No. 9 are embodiments of the present invention. Each test specimen consists of two outer pieces of wood positioned around an inner piece of wood, with these three pieces of wood joined together with bolts (see Figures 13 and 14). The wood will be made from cypress, with the grain direction aligned with the length of the wood. The cross-section of the wood will be a 120mm x 120mm square. The screws used to secure the circular plates (steel plates) are Neda Knot screws manufactured by Synnegic Co., Ltd., and are the size shown in Figure 10.

[0025] Only test specimen No. 6 used a circular plate (steel plate) of type B, while all other test specimens used a circular plate (steel plate) of type A. As shown in Figure 11, in type A, there is no countersunk recess for accommodating the circular plate on the side of the wood, and the circular plate is in contact with the surface of the wood. Also, in type A, the screw head is accommodated in a countersunk recess in the screw hole of the circular plate, and the base end face of the screw is approximately flush with the surface of the circular plate. On the other hand, in type B, as shown in Figure 12, the circular plate is accommodated in a countersunk recess in the wood. Also, in type B, there is no countersunk recess for accommodating the screw head in the screw hole of the circular plate. A joint direction that is perpendicular to the fiber direction means that the inner and outer pieces of wood are joined together, positioned approximately parallel to each other, as shown in Figure 13. A joint direction that is perpendicular to the fiber direction means that the inner piece of wood and the two outer pieces of wood are joined together, positioned approximately perpendicular to each other, as shown in Figure 14.

[0026] In the loading test, as shown in Figures 13 and 14, the outer wood pieces constituting the test specimen were placed on a jig, and a vertical load (shear force) P was applied to the inner wood pieces in the direction indicated by the white arrows in Figures 13 and 14. The relative displacement δ between the wood pieces was then measured. Figures 15 and 16 show the loading test results (showing the relationship between the vertical load applied to the test specimen and the relative displacement between the wood pieces). In addition, the yield strength Py (24kN) calculated from the material strengths of the wood, bolts, and screws is also shown in Figures 15 and 16.

[0027] As shown in Figures 15 and 16, when the joint direction was aligned with the fiber direction, the maximum load-bearing capacity of each specimen reached more than five times the yield strength calculated from the strength of each material, compared to when the joint direction was perpendicular to the fiber direction. Furthermore, when the joint direction was aligned with the fiber direction, the failure mode of each specimen was such that after deformation of the relative displacement between the wood pieces reached 40 mm or more, splitting failure occurred around the through-holes in the wood through which the bolts were inserted, leading to the maximum load-bearing capacity. For each test specimen, the initial stiffness in the relationship between the vertical load P and the relative displacement δ showed high stiffness up to load levels exceeding the yield strength Py calculated from the strength of each material. The maximum load-bearing capacity of the test specimens in the load-displacement relationship shown in Figures 15 and 16 corresponds to the yield strength of the joint structure of the timber members. Thus, based on the test results regarding the maximum load-bearing capacity, relative displacement at maximum load-bearing capacity, initial stiffness, and failure mode of each test specimen in the embodiment, it can be seen that the wood member joining structure of the present invention can firmly join wood members together.

[0028] Furthermore, the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that can achieve the objectives of the present invention are included within the scope of the present invention. In the embodiments described above, the steel plate 20 was fixed to the wood 10A to 10C with screws 21. However, the invention is not limited to this, and the steel plate 20 may also be fixed to the wood 10A to 10C with an adhesive applied to the joint surface between the steel plate 20 and the wood 10A to 10C, or the steel plate 20 may be fixed to the wood 10A to 10C with an adhesive in addition to screws 21. When the steel plate 20 is fixed to the wood 10A to 10C using an adhesive in this way, the following effects are obtained. That is, the shear deformation along the joint surface between the wood 10A to 10C is further suppressed by the steel plate 20 fixed with adhesive, thereby increasing the joint strength and shear rigidity between the wood 10A to 10C. [Explanation of Symbols]

[0029] 1…Wooden bridge (joining structure of wooden members) 1A…Joining structure of wooden members 10, 10A, 10B, 10C... Wood (wooden components) 11A, 11B...Side (outer surface) 11C...Bottom surface of recess 12...Through hole 13…Recess where the steel plate is housed 14…Recess where the bearing plate is housed 20...Steel plate 21...Screw (rod-shaped fastener) 22...Through hole 23...Screw hole 30... Bearing plate 31... Through hole 40... Bolt 41... Nut

Claims

1. A joint structure for joining multiple wooden members, Each of the aforementioned wooden members has a through hole formed therein. A steel plate with a through hole formed in it is attached to at least one outer surface of each of the aforementioned wooden members with a rod-shaped fastener. The sides of the wooden members are arranged so that they are in contact with each other, and are fixed together with bolts inserted through through holes in the wooden members and through holes in the steel plates. A joint structure for wooden members, characterized in that the shear resistance area of ​​the wooden member is increased by the fastener.

2. The joint structure for a wooden member according to claim 1, characterized in that the end face of the rod-shaped fastener is substantially flush with the surface of the steel plate.

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