Joining structures for timber members and timber frames

Abstract

To provide a joint structure for wooden members that can transmit rotational moments between wooden members. [Solution] The column 10, the first beam 11, and the second beam 12 are constructed by joining a pair of wooden members 30A and 30B together. The opposing ends of the wooden members 30A and 30B are overlapped at an overlapping portion 31, and this overlapping portion 31 of the wooden members 30A and 30B is tightened from the outside with an annular fastening member 41. This allows rotational moment to be transmitted between the wooden members 30A and 30B, unlike when the end faces of the wooden members are simply joined together.

Description

[Technical Field]

[0001] The present invention relates to a joint structure for wooden members constructed by joining a pair of wooden members together, and to a wooden frame equipped with this joint structure for wooden members. [Background technology]

[0002] Conventionally, a pair of wooden members have been joined together using a lap joint (see Patent Documents 1 and 2). Patent Document 1 shows a joining structure for structural materials. A lap joint is provided on one end of each structural material, and the two structural materials are joined together by engaging the lap joints of the two structural materials 1. Patent Document 2 shows a wood joining structure in which a pair of pieces of wood are joined together in a crisscross pattern on the same plane. The pieces of wood have notched recesses formed in the thickness direction that are half the thickness of the material, and the pair of pieces of wood are joined by fitting the notched recesses of the pieces of wood together. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2017-128968 [Patent Document 2] Japanese Patent Publication No. 2007-9437 [Overview of the project] [Problems that the invention aims to solve]

[0004] The present invention aims to provide a joint structure for wooden members that can transmit rotational moments between wooden members, and a wooden frame equipped with this joint structure for wooden members. [Means for solving the problem]

[0005] The joint structure for wooden members of the first invention (for example, the column 10, first beam 11, and second beam 12 described later) is a joint structure for wooden members that joins a pair of wooden members (for example, wooden members 30A and 30B described later) together, wherein the opposing ends of the wooden members are arranged to overlap at an overlapping portion (for example, the overlapping portion 31 described later), and the overlapping portion of the wooden members is fastened from the outside with an annular fastening member (for example, the fastening member 41 described later).

[0006] According to this invention, the overlapping portions of a pair of wooden members are overlapped, and the overlapping portions of these wooden members are fastened from the outside with a ring-shaped fastening member (wrapping fastening). In this way, since the overlapping portions of the wooden members are overlapped and fastened with a binding member, unlike when the end faces of the wooden members are simply joined together, rotational moments can be transmitted between the wooden members, thus ensuring the structural stability of the joint structure of the wooden members.

[0007] Furthermore, by overlapping the wooden components and securing them with fastening members, the rigidity of the joints between the wooden components can be increased, minimizing positional displacement during construction. Furthermore, by removing the binding members, the joint structure of the wooden members can be easily dismantled.

[0008] The joint structure for wooden members of the second invention is characterized in that a notch (for example, a notch 32 described later) and a projection (for example, a projection 33 described later) are formed in the overlapping portion of the wooden members, the projection of one wooden member is fitted into the notch of the other wooden member, and the projection of the other wooden member is fitted into the notch of the one wooden member.

[0009] According to this invention, a projection of one wooden member is fitted into a notch of the other wooden member, and a projection of the other wooden member is fitted into a notch of the first wooden member (lap joint). By fitting the projections of the wooden members into opposing notches in this way, a tight joint between the wooden members becomes possible. Furthermore, misalignment between the wooden members is suppressed, improving durability and stability.

[0010] The third invention is a wooden frame having the above-described joint structure for wooden members (for example, wooden frame 1 described later), comprising a column (for example, column 10 described later) and beams joined to the column (for example, a first beam 11 and a second beam 12 described later), wherein at least one of the column and the beam is constructed by joining a pair of wooden members (for example, wooden members 30A and 30B described later), and the wooden members comprise two or more substantially parallel shaft members (for example, shaft members 20 described later) and a connecting member (for example, a connecting member 21 described later) interposed between the shaft members, wherein the shaft members and the connecting member are joined by at least one of mortise and tenon joints, dowel joints, adhesive, and connecting hardware penetrating the connecting member, and at least one of the plurality of shaft members is shorter in the axial direction than the other shaft members and forms an overlapping portion of the wooden members.

[0011] According to this invention, since a column is constructed by joining multiple axial members with a connecting member (jointed column), the rigidity and buckling strength of the column can be increased. Furthermore, since a beam is constructed by joining multiple axial members with a connecting member (overlapping open beam), the rigidity of the beam can be increased. Furthermore, since the beam is formed by combining two or more axial members and connecting members, the height (beam depth) of the beam can be increased, and the span length of the beam can be increased. Furthermore, since columns and beams are constructed using multiple structural members, small-section timber can be used as structural members, thereby reducing construction costs.

[0012] Furthermore, by joining the shaft member and the connecting member using at least one of the following methods: mortise and tenon joint, dowel joint, adhesive, and connecting hardware, a highly rigid wooden member joining structure can be realized without using large-section timber as the shaft member. Furthermore, since the axial members and connecting members constituting the columns and beams are joined using at least one of the following methods: mortise and tenon joints, dowel joints, adhesive, or metal connectors, the timber frame can be dismantled relatively easily, and the axial members and connecting members can be reused. In addition, since the shaft material and the hanger material have a small cross-section, they are lightweight and can be transported manually and constructed even when heavy machinery cannot be used. Also, the shaft material and the hanger material can be easily reused and easily constructed.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a joining structure of wooden members capable of transmitting a rotational moment between wooden members, and a wooden structure provided with this joining structure of wooden members.

Brief Description of the Drawings

[0014] [Figure 1] It is a schematic perspective view of a wooden structure according to a first embodiment of the present invention. [Figure 2] It is an enlarged perspective view of the portion surrounded by the broken line A of the wooden structure in FIG. 1. [Figure 3] It is an enlarged perspective view of the portion surrounded by the broken line B of the wooden structure in FIG. 1. [Figure 4] It is a side view of the joint portion between the wooden members of the first beam constituting the wooden structure according to the first embodiment. [Figure 5] It is a C-C cross-sectional view of the first beam in FIG. 4. [Figure 6] It is a side view (a view omitting the fiber reinforcing material and the binding member) of the joint portion between the wooden members of the first beam. [Figure 7] It is an exploded perspective view of the first beam. [Figure 8] It is a schematic perspective view of the joint portion between wooden members. [Figure 9] It is a schematic side view and a plan view of the joint portion between wooden members. [Figure 10] It is a side view of the joint portion between the wooden members of the first beam constituting the wooden structure according to a second embodiment of the present invention. [Figure 11] It is an exploded view of the first beam constituting the wooden structure according to the second embodiment.

Mode for Carrying Out the Invention

[0015] The present invention is a joining structure for wooden members, in which the ends of opposing wooden members are overlapped (overlapping portion), and the wooden members are joined together by tightening this overlapping portion from the outside with an annular fastening member. Embodiments of the joint structure for wooden members include a form in which single wooden members are stacked vertically and fastened with a binding member (Figures 8 and 9), a first embodiment (Figures 4 to 7) in which the wooden member is composed of four shaft members and a connecting member of different lengths, with the longest shaft member fitted into the connecting member and a ring-shaped binding member fastened, and a second embodiment (Figures 10 and 11) in which the wooden member is composed of four shaft members and a connecting member of different lengths, with the projection of the longest shaft member fitted into a notch in the connecting member and a ring-shaped binding member fastened.

[0016] Embodiments of the present invention will be described below with reference to the drawings. In the following description of embodiments, identical components will be denoted by the same reference numerals, and their descriptions will be omitted or simplified. [First Embodiment] Figure 1 is a schematic perspective view of a wooden frame structure 1 according to the first embodiment of the present invention. The wooden frame 1 comprises a plurality of columns 10 arranged in two rows on the floor surface 2, a plurality of first beams 11 extending in the longitudinal direction (long side direction) by connecting the column tops of the columns 10, and a plurality of second beams 12 extending in the inter-beam direction (short side direction) by connecting the column tops of the columns 10.

[0017] Figure 2 is an enlarged perspective view of the portion enclosed by dashed line A (first beam 11) of the timber frame 1 in Figure 1. Figure 3 is an enlarged perspective view of the portion enclosed by dashed line B of the timber frame 1 in Figure 1. The first beam 11 will be described below, but the column 10 and the second beam 12 have a similar configuration. The first beam 11 comprises four shaft members 20 that are substantially parallel to each other, and connecting members 21 interposed between the shaft members 20 at predetermined intervals to join the shaft members 20 together. Specifically, the connecting members 21 have four recesses 22 formed therein, and the four shaft members 20 are fitted into these four recesses 22 (see Figure 5). The shaft member 20 and the connecting member 21 are joined by at least one of the following: mortise and tenon joints, dowel joints, adhesive, and connecting hardware that penetrates the connecting member.

[0018] At the joints between the column 10, the first beam 11, and the second beam 12, as shown in Figure 3, the two upper and lower axial members 20 on the outer side in the inter-beam direction of the first beam 11 are sandwiched between the axial members 20 of the column 10, and the two lower axial members 20 of the first beam 11 are sandwiched between the upper and lower axial members 20 of the second beam 12. Furthermore, the two upper and lower axial members 20 on the inner side in the longitudinal direction of the second beam 12 are sandwiched between the axial members 20 of the column 10, and the two upper axial members 20 of the second beam 12 are sandwiched between the upper and lower axial members 20 of the first beam 11. Furthermore, the two axial members 20 on the inner side of the column 10 in the beam direction are sandwiched between the axial members 20 of the first beam 11, and the two axial members 20 on the outer side of the column 10 in the girder direction are sandwiched between the axial members 20 of the second beam 12.

[0019] The first beam 11 described above is constructed by joining a pair of wooden members 30A and 30B that are arranged in a straight line. The same structure is used for the column 10 and the second beam 12. Figure 4 is a side view of the joint between the wooden members 30A and 30B of the first beam 11. Figure 5 is a cross-sectional view of the first beam 11 shown in Figure 4. Figure 6 is a side view of the joint between the wooden members 30A and 30B of the first beam 11 (with the fiber reinforcement 40 and binding member 41 omitted). Figure 7 is an exploded perspective view of the first beam 11.

[0020] The wooden members 30A and 30B each comprise four shaft members 20 that are substantially parallel to each other, and connecting members 21 that are interposed between the shaft members 20 at predetermined intervals to join the shaft members 20 together. An overlapping portion 31 is formed at the mutually opposing ends of the wooden members 30A and 30B. In other words, the two lower shaft members 20 of the wooden member 30A are shorter in the axial direction than the two upper shaft members 20, forming an overlapping section 31. In this overlapping section 31, the lower surface of the connecting member 21 located at the end of the wooden member 30A is exposed. Furthermore, the two upper shaft members 20 of the wooden member 30B are shorter in the axial direction than the two lower shaft members 20, forming an overlapping section 31. In this overlapping section 31, the upper surface of the connecting member 21 located at the end of the wooden member 30B is exposed.

[0021] The overlapping portions 31 of the pair of wooden members 30A and 30B are arranged overlapping each other. Specifically, the upper shaft member 20 of one wooden member 30A abuts against the end faces of the two upper shaft members 20 of the other wooden member 30B and fits into the recess 22 on the upper surface of the joinery member 21 at the end of the wooden member 30B. Also, the lower shaft member 20 of the other wooden member 30B abuts against the end faces of the two lower shaft members 20 of the one wooden member 30A and fits into the recess 22 on the lower surface of the joinery member 21 at the end of the wooden member 30A.

[0022] The overlapping portions 31 of the wooden members 30A and 30B are fastened together from the outside with a binding member 41. Specifically, the upper shaft member 20 of one wooden member 30A, which is fitted into the connecting member 21 of the other wooden member 30B, and the lower shaft member 20 of the other wooden member 30B, which is fitted into the connecting member 21 of the one wooden member 30A, are wrapped with a strip-shaped fiber reinforcement material 40 from the outside, and are then fastened with an annular binding member 41. The fiber reinforcement material 40 is, for example, carbon fiber, aramid fiber, glass fiber, epoxy resin, or vinyl ester resin.

[0023] The following describes the calculation methods for the rotation center, rotational stiffness, yield deformation angle, yield moment, secondary stiffness, and maximum moment of joints between wooden members. For joints between wooden members, the cross-sectional area of ​​each wooden member and the binding member is determined so that the maximum moment generated at the joint is less than the yield moment. Figure 8 is a schematic perspective view of the joint between two wooden members. Figure 9(a) is a schematic side view of the joint between two wooden members, and Figure 9(b) is a schematic plan view of the joint between two wooden members. Specifically, Figures 8 and 9 show a state in which a axial member (wooden member) is placed on top of a bridging member (wooden member) and fastened with a binding member. The force acting vertically on the right side of the joint in Figure 9 is ΣN. R Let's assume this ΣN R This can be expressed by the following equation (1), where k is the overall rigidity of the right side of the joint and θ is the deformation angle of the entire right side of the joint.

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[0024] Furthermore, k is expressed by the following equation (2), where k1 is the rotational stiffness due to the indentation of the wooden member on the right side of Figure 9, and k2 is the rotational stiffness due to the indentation of the wooden member on the left side of Figure 9.

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[0025] Here, k1 is expressed as the indentation of the triangle in Figure 9, with the end distance x1 = 0. k2 is expressed as the indentation of the triangle in Figure 9, with the end distance x1 = ∞. Then k1 and k2 are given by equations (3) and (4) below. Here, E 90 This is the Young's modulus in the orthogonal direction of the shaft member and the connecting member.

[0026]

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[0027] Therefore, k is expressed by the following equation (5), ΣN R This can be expressed by the following equation (6).

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[0028] Here, n is a substitution coefficient that varies depending on the tree species; n=7 for Douglas fir, n=6 for cypress, and n=5 for Japanese cedar. The force acting vertically on the left side of the joint in Figure 9 (the part where the binding member is provided) is ΣN. L Let's assume this ΣN L This is expressed by the following equation (7), where k′ is the vertical indentation rigidity of the entire left side of the joint and δ is the indentation deformation of the entire left side of the joint.

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[0029] Furthermore, k' is expressed by the following equation (8), where k3 is the spring stiffness of the upper and lower washers with equal displacement and k4 is the tensile stiffness of the bolt.

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[0030] k3 is given by the following equation (9). Here, x0, x2, y0, and y2 are the width of the fastening member, the end distance from the fastening band to the end of the member in the x direction, the embedment length of the fastening band, and the edge distance from the fastening band to the edge of the member in the y direction, respectively.

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[0031] Furthermore, k4 is given by equation (10) below. Here, EA is the axial stiffness, which is the product of the Young's modulus and cross-sectional area of ​​the cable tie.

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[0032] Therefore, k' is expressed by the following equation (11), ΣN L This can be expressed by the following equation (12).

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[0033] (A) Center of rotation Vertical balance is expressed by the following equations (13) and (14).

Equation

[0034] (B) Rotational rigidity The balance of the moment around point O is as shown in equation (15).

Equation

Equation

[0035] (C) Yield deformation angle The yield deformation angle θ y becomes smaller as the end distance x1 increases, and is determined by θ2. At this time, θ 2y is expressed by the following equation (17).

Equation

Equation

[0036] (D) Yield moment The yield moment M y is M y = k θ [[ID={73]]·θ y , and is obtained from equations (16) to (18). Here, k θ is the rotational rigidity of the entire joint.

[0037] (E) Secondary stiffness The secondary stiffness k2 due to indentation is k θ Since it is known to be about 1 / 8 of that, it can be calculated using the following formula (19).

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[0038] (F) Maximum moment M / Z = F due to bending stress of the member b The value of M at which this occurs is the maximum bending moment.

[0039] This embodiment provides the following effects. (1) The overlapping portions 31 of a pair of wooden members 30A and 30B are overlapped, and the overlapping portions 31 of these wooden members 30A and 30B are fastened together with a binding member 41 (wrapping and securing). In this way, the overlapping portions 31 of the wooden members 30A and 30B are overlapped and fastened with the fastening member 41. Unlike when the end faces of the wooden members are simply joined together, rotational moment can be transmitted between the wooden members 30A and 30B, thereby ensuring the structural stability of the columns 10 and beams 11 and 12. Furthermore, by overlapping the overlapping portions 31 of the wooden members 30A and 30B and fastening them with the binding member 41, the rigidity of the joint between the wooden members 30A and 30B is increased, minimizing positional displacement during construction. Furthermore, by removing the binding member 41, the columns 10, beams 11, and 12 can be easily dismantled.

[0040] (2) Since the column 10 is constructed by joining four shaft members 20 together with a connecting member 21 (jointed column), the rigidity and buckling strength of the column 10 can be increased. Also, since the beams 11 and 12 are constructed by joining four shaft members 20 together with a connecting member 21 (overlapping open beam), the rigidity of the beams 11 and 12 can be increased. Furthermore, since beams 11 and 12 are formed by combining four axial members 20 and connecting members 21, the height (beam depth) of the beams can be increased, and the span length of the beams can be increased. Furthermore, since the columns 10 and beams 11 and 12 are constructed by including multiple axial members 20, small-section timber can be used as the axial members 20, thereby reducing construction costs. Furthermore, by joining the shaft member 20 and the connecting member 21 with at least one of mortise and tenon joints, dowel joints, adhesives, and connecting hardware, a highly rigid wooden member joining structure can be realized without using large-section timber as the shaft member 20. Furthermore, since the axial members 20 and the connecting members 21 that make up the columns 10 and beams 11 and 12 are joined by at least one of the following: mortise and tenon joints, dowel joints, adhesive, and connecting hardware, the wooden frame 1 can be dismantled relatively easily, and the axial members 20 and connecting members 21 can be reused. Furthermore, the shaft members 20 and the connecting members 21 are lightweight due to their small cross-section, and can be transported and installed manually even when heavy machinery cannot be used. In addition, the shaft members 20 and the connecting members 21 can be easily reused and installed.

[0041] [Second Embodiment] Figure 10 is a side view of the joint between the wooden members 30A and 30B of the first beam 11A constituting the wooden frame 1 according to the second embodiment of the present invention. Figure 11 is an exploded view of the first beam 11A constituting the wooden frame 1 according to the second embodiment. In this embodiment, the overlapping portion 31 of the wooden members 30A and 30B is formed with a notch 32 and a projection 33, which is different from the first embodiment.

[0042] Specifically, a projection 33 is formed on the lower surface of the tip of the upper shaft member 20 of one of the wooden members 30A, and a notch 32 is formed on the lower surface of the connecting member 21 of this wooden member 30A. Similarly, a projection 33 is formed on the upper surface of the tip of the lower shaft member 20 of the other wooden member 30B, and a notch 32 is formed on the lower surface of the connecting member 21 of this wooden member 30B.

[0043] When the overlapping portions 31 of the pair of wooden members 30A and 30B are placed on top of each other, the arrangement will be as follows. In other words, the upper shaft member 20 of one wooden member 30A abuts against the end faces of the two upper shaft members 20 of the other wooden member 30B, and the projection 33 of the wooden member 30A fits into the notch 32 on the upper surface of the connecting member 21 of the wooden member 30B. Furthermore, the lower shaft member 20 of the other wooden member 30B abuts against the end faces of the two lower shaft members 20 of the one wooden member 30A, and the projection 33 of the wooden member 30B fits into the notch 32 on the lower surface of the connecting member 21 of the wooden member 30A. According to this embodiment, in addition to the effects of (1) and (2) described above, the following effects are obtained.

[0044] (3) The projection 33 of one wooden member 30A is fitted into the notch 32 of the other wooden member 30B, and the projection 33 of the other wooden member 30B is fitted into the notch 32 of the one wooden member 30A (lap joint). By fitting the projections 33 of each wooden member 30A and 30B into the notches 32 of the opposing wooden members 30A and 30B in this way, a precise joint between the wooden members 30A and 30B becomes possible. In addition, misalignment between the wooden members 30A and 30B is suppressed, improving durability and stability. 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. [Explanation of Symbols]

[0045] 1...Wood frame 2...Floor 10...Column 11, 11A...First beam 12...Second beam 20...Structural member 21...Connecting member 22...Recess 30A, 30B...Wooden component 31...Overlapping section 32...Notched section 33...Protrusion 40…Fiber reinforcement material 41…Binding material

Claims

1. A joining structure for wooden members that connects a pair of wooden members, The opposing ends of the aforementioned wooden members are arranged to overlap at the overlapping portion. A joining structure for wooden members, characterized in that the overlapping portions of the wooden members are fastened from the outside with an annular fastening member.

2. Notches and protrusions are formed in the overlapping portions of the aforementioned wooden members. The projection of one of the wooden members is fitted into the notch of the other wooden member. The joint structure for wooden members according to claim 1, characterized in that the projection of the other wooden member is fitted into the notch of the one wooden member.

3. A wooden frame comprising the wooden member joining structure described in claim 1 or 2, It comprises a column and a beam joined to the column, At least one of the column and the beam is formed by joining the pair of wooden members together. The aforementioned wooden member comprises four or more shaft members that are substantially parallel to each other, and a connecting member interposed between the shaft members. The shaft member and the connecting member are joined by at least one of the following: mortise and tenon joint, dowel joint, adhesive, and connecting hardware that penetrates the connecting member. A wooden frame characterized in that at least one of the plurality of axial members is shorter in the axial direction than the other axial members and forms an overlapping portion of the wooden members.

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