Connecting structure

Abstract

To provide a connecting structure that connects columns on upper and lower floors and is suitable for medium and high-rise buildings.SOLUTION: A connecting structure 100 connects a lower floor column 1 and an upper floor column 2, and has a connection hardware 130 provided between the lower floor column 1 and the upper floor column 2, a second bolt 120 protruding from the lower floor column 1 toward the upper floor column 2, and a pair of second nuts 121 screwed onto the second bolt 120. The connection hardware 130 has a lower surface portion 131 through which the second bolt 120 penetrates, and an upper surface portion 132 that is fixed to the upper floor column 2. The lower surface portion 131 is sandwiched from above and below by the pair of second nuts 121 that are screwed onto the second bolts 120. Furthermore, the connection hardware 130 has a lower surface portion 131, an upper surface portion 132, and a side portion 133 connecting the lower surface portion 131 and the upper surface portion 132. The side portion 133 is more extensible than the lower surface portion 131 and the upper surface portion 132.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a connection structure.

Background Art

[0002] Patent Document 1 discloses a column including a column timber as a column body and connecting metal objects attached to both ends of the column timber. In this column, the connecting metal object attached to the lower end of the column timber is in direct contact with the floor part.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The invention described in Patent Document 1 is an invention of a mobile unit that can be easily relocated and installed. Since the mobile unit is generally a low - rise building, the load from the column (the load applied to the floor part) is not so large. On the other hand, in the case of a building with many floors such as a mid - to high - rise building, the load from the column becomes larger on the lower floors. Therefore, there is a risk that the load from the column may cause indentation in other structural members (such as the floor part). The present invention has been made in view of the above circumstances, and its problem is to provide a connection structure for connecting columns of upper and lower floors, which is suitable for mid - to high - rise buildings.

Means for Solving the Problems

[0005] The invention according to claim 1 is, for example, as shown in FIGS. 1 to 14, connection structures 100, 200, 300 for connecting a lower - floor column 1 and an upper - floor column 2, a connecting metal object 130 provided between the lower - floor column 1 and the upper - floor column 2, A bolt (second bolt 120) protruding from the lower column 1 toward the upper column 2, and a pair of nuts (pair of second nuts 121) screwed onto the bolt, The connecting fitting 130 includes a lower surface portion 131 through which the bolt passes and an upper surface portion 132 fixed to the upper column 2. The lower surface portion 131 is characterized by being sandwiched from above and below by the pair of nuts screwed onto the bolt.

[0006] According to the invention described in claim 1, among the pair of nuts (pair of second nuts 121), the lower nut can resist downward force (support the load from the upper column 2), so it is possible to avoid indentation into other structural members of the building body (such as the lower column 1), and it is suitable for mid - to high - rise buildings.

[0007] According to the invention described in claim 2, as shown in FIGS. 1 to 14 for example, in the connection structures 100, 200, 300 described in claim 1, The connecting fitting 130 includes the lower surface portion 131, the upper surface portion 132, and a side surface portion 133 connecting the lower surface portion 131 and the upper surface portion 132. The side surface portion 133 is characterized by having higher extensibility than the lower surface portion 131 and the upper surface portion 132.

[0008] According to the invention described in claim 2, since the energy absorption performance of the side surface portion 133 is higher than that of the lower surface portion 131 and the upper surface portion 132, it is possible to sufficiently resist horizontal loads during earthquakes, typhoons, etc., and it is suitable for mid - to high - rise buildings.

[0009] According to the invention described in claim 3, as shown in FIGS. 1 to 13 for example, in the connection structures 100, 200 described in claim 1, The upper column 2 includes column timbers 11, 12, 13 and wood fittings 21, 22, 23 covering the upper and lower ends of the column timbers 11, 12, 13. The lower floor column 1 is characterized by including column timbers 11, 12, 13 and wooden caps 21, 22, 23 that cover both the upper and lower ends of the column timbers 11, 12, 13.

[0010] According to the invention described in claim 3, splitting of the column timbers 11, 12, 13 can be prevented. Further, since the lower floor column 1 and the upper floor column 2 are wooden columns, it becomes possible to contribute to the realization of a decarbonized society through the promotion of carbon neutrality and the achievement of the goals of SDGs (Sustainable Development Goals).

[0011] The invention described in claim 4 is, for example, as shown in FIGS. 12 and 13, in the connection structure 200 described in claim 3, the connection structure 200 includes a transmission member 40 that constitutes the upper end portion of the lower floor column 1, the lower floor column 1 includes a plurality of the column timbers 11, 12, 13, the transmission member 40 includes first metal fittings fixed to each of the plurality of column timbers 11, 12, 13 and a second metal fitting (plate-like metal fitting 41) that connects the first metal fittings to each other, the bolt (second bolt 120) is characterized by protruding from any one of the plurality of first metal fittings toward the upper floor column 2.

[0012] According to the invention described in claim 4, the transmission member 40 can disperse a downward force (load from the upper floor column 2) to the plurality of column timbers 11, 12, 13 that constitute the lower floor column 1, so it is possible to avoid the occurrence of indentation in the lower floor column 1, and it is suitable for mid- to high-rise buildings.

[0013] The invention described in claim 5 is, for example, as shown in FIGS. 12 and 13, in the connection structure 200 described in claim 4, the connection metal fitting 130 can be diverted to the first metal fitting, which is characterized.

[0014] According to the invention described in claim 5, it is not necessary to prepare a metal fitting different from the connection metal fitting 130 as the first metal fitting of the transmission member 40.

[0015] The invention according to claim 6 is, for example, as shown in FIGS. 12 and 13, in the connection structure 200 according to claim 4, the second metal fitting (plate-shaped metal fitting 41) is characterized by having higher extensibility than the lower surface portion 131 and the upper surface portion 132.

[0016] According to the invention of claim 6, since the energy absorption performance of the second metal fitting (plate-shaped metal fitting 41) is higher than the energy absorption performance of the lower surface portion 131 and the upper surface portion 132, it is possible to sufficiently resist horizontal loads such as during an earthquake or a typhoon, and it is suitable for mid- to high-rise buildings.

[0017] The invention according to claim 7 is, for example, as shown in FIG. 14, in the connection structure 300 according to claim 1, the upper floor column 2 includes column timbers 11, 12, 13 and metal fittings for the ends 21, 22, 23 that cover the upper and lower ends of the column timbers 11, 12, 13, the lower floor structure including the lower floor column 1 is made of reinforced concrete, the bolt (second bolt 120) is characterized by protruding from the lower floor structure toward the upper floor column 2.

[0018] According to the invention of claim 7, splitting of the column timbers 11, 12, 13 can be prevented. Also, since the lower floor structure including the lower floor column 1 is made of reinforced concrete, it is suitable for mid- to high-rise buildings. Further, since the upper floor column 2 is a wooden column, it is possible to contribute to the realization of a decarbonized society through the promotion of carbon neutrality and the achievement of the SDGs goals.

[0019] The invention according to claim 8 is, for example, as shown in FIG. 14, in the connection structure 300 according to claim 7, the connection structure 300 includes a fixing plate (second fixing plate 125) through which the bolt (second bolt 120) passes, the fixing plate is a nut that screws onto the bolt and is fixed to the lower floor structure by a nut (sixth nut 126) different from the pair of nuts (second nuts 121).

[0020] According to the invention described in claim 8, since the downward force (load from the upper-story column 2) transmitted to the lower-story structure can be dispersed by the fixing plate (the second fixing plate 125), it is possible to avoid the occurrence of subsidence in the lower-story structure, and it is suitable for mid-rise and high-rise buildings.

Effect of the Invention

[0021] According to the present invention, a connection structure suitable for mid-rise and high-rise buildings can be provided.

Brief Description of the Drawings

[0022]

Figure 1

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Figure 8

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Figure 14

Mode for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, although various technically preferable limitations are imposed on the embodiments described below for carrying out the present invention, the technical scope of the present invention is not limited to the following embodiments (and modified examples) and illustrated examples. In addition, the directions (front-back direction, left-right direction, up-down direction) in the following embodiments (and modified examples) and illustrated examples are set only for convenience of explanation.

[0024] In the following description, when ordinal numbers such as "first" and "second" are attached to a common name, the ordinal numbers are used only for the purpose of identifying the object to which they are attached. The ordinal number does not limit the object to which it is attached to a specific object, and the ordinal number does not specify the order, rank, sequence, class, priority, and inferiority of the object to which it is attached.

[0025] <First Embodiment> [Connection Structure] FIG. 1 is a longitudinal sectional view showing an example of a connection structure 100. The connection structure 100 is a structure for connecting the lower-story column 1 and the upper-story column 2 in a building, and is provided in a multi-story building. The lower-story column 1 includes a column timber 11, a wooden base member 21 that covers the lower end portion of the column timber 11, and a wooden base member 21 that covers the upper end portion of the column timber 11. The upper-story column 2 includes a column timber 11, a wooden base member 21 that covers the lower end portion of the column timber 11, and a wooden base member 21 that covers the upper end portion of the column timber 11.

[0026] The column timber 11 has a square cross-section. In the present embodiment, the dimension of the column timber 11 in the left-right direction is set to 90 mm, and the dimension of the column timber 11 in the front-back direction (the direction orthogonal to both the up-down direction and the left-right direction) is set to 90 mm. That is, in the present embodiment, the cross-sectional dimension of the column timber 11 is set to 90×90 mm, but it is not limited thereto.

[0027] As shown in FIG. 3(b) described later, a notch portion 10a is formed at the upper end portion of the column timber 11 by cutting out the corner portion between the upper end surface of the column timber 11 and the side surface of the column timber 11. That is, four notch portions 10a that are connected in an L-shape are provided at the upper end portion of the column timber 11. Further, four notch portions 10a that are connected in an L-shape are also provided at the lower end portion of the column timber 11. In the present embodiment, the height dimension (the dimension in the up-down direction) of the notch portion 10a is set to 17.5 mm, but it is not limited thereto. Further, in the present embodiment, the depth dimension of the notch portion 10a is set to 3 mm, but it is not limited thereto. Here, the depth dimension of the notch portion 10a is the dimension in the front-back direction when the notch portion 10a is provided along the left-right direction (the notch portion 10a provided on the front side surface and the rear side surface among the four side surfaces of the column timber 11), and is the dimension in the left-right direction when the notch portion 10a is provided along the front-back direction (the notch portion 10a provided on the left side surface and the right side surface among the four side surfaces of the column timber 11).

[0028] FIG. 2 is a view showing an example of the lower-story column 1 and the upper-story column 2 in a state where the bolts 110 and 120 project. Bolt insertion holes are formed at the lower end portion and the upper end portion of the column timber 11. The first bolt 110 is inserted into the bolt insertion hole at the lower end portion of the column timber 11, and the second bolt 120 is inserted into the bolt insertion hole at the upper end portion of the column timber 11. In this embodiment, the wooden material 11 for columns and the bolts 110 and 120 are joined by a method of inserting and adhesively bonding steel bars (a method of inserting steel bars into pre-drilled holes in the wooden member and filling with an adhesive), but it is not limited thereto.

[0029] The first bolt 110 is a fully threaded bolt. The first bolt 110 is inserted into the lower end of the wooden material 11 for columns in a state where the center line of the first bolt 110 (the center line parallel to the length direction of the first bolt 110) coincides with the center line of the wooden material 11 for columns (the center line parallel to the length direction of the wooden material 11 for columns). In this embodiment, for the wooden material 11 for columns installed on the top floor, the embedding depth of the first bolt 110 (the depth of the bolt insertion hole formed at the lower end of the wooden material 11 for columns) is set to 300 mm, and for the wooden material 11 for columns installed on floors other than the top floor, the embedding depth of the first bolt 110 is set to 800 mm, but it is not limited thereto. Also, in this embodiment, the diameter (nominal diameter) of the first bolt 110 is set to 24 mm, but it is not limited thereto.

[0030] The second bolt 120 is a fully threaded bolt. The second bolt 120 is inserted into the upper end of the wooden material 11 for columns in a state where the center line of the second bolt 120 (the center line parallel to the length direction of the second bolt 120) coincides with the center line of the wooden material 11 for columns (the center line parallel to the length direction of the wooden material 11 for columns). In this embodiment, the second bolt 120 is not embedded in the wooden material 11 for columns installed on the top floor. That is, no bolt insertion hole is formed at the upper end of the wooden material 11 for columns installed on the top floor. Also, in this embodiment, the embedding depth of the second bolt 120 (the depth of the bolt insertion hole formed at the upper end of the wooden material 11 for columns) is set to 800 mm, but it is not limited thereto. Also, in this embodiment, the diameter (nominal diameter) of the second bolt 120 is set to 24 mm, but it is not limited thereto.

[0031] FIG. 3 is a diagram showing an example of the end cap 21, where (a) is a plan view and (b) is a longitudinal sectional view showing the relationship with the column timber 11. In FIG. 3, the end cap 21 covering the upper end portion of the column timber 11 is illustrated. Since the end cap 21 covering the lower end portion of the column timber 11 is the same as the end cap 21 covering the upper end portion of the column timber 11, the illustration and description thereof are omitted. The end cap 21 is a member for preventing the column timber 11 from splitting and has a U-shaped longitudinal section. Specifically, the end cap 21 includes a substantially square bottom surface portion 21a and upright surface portions 21b that stand up from each of the four end portions of the bottom surface portion 21a.

[0032] In a state where the end cap 21 is attached to the column timber 11, the bottom surface portion 21a of the end cap 21 contacts the end surface of the column timber 11 (the lower end surface when the end cap 21 is the end cap covering the lower end portion of the column timber 11, and the upper end surface when the end cap 21 is the end cap covering the upper end portion of the column timber 11), and the upright surface portions 21b of the end cap 21 are disposed within the notch portion 10a of the column timber 11.

[0033] In this embodiment, the dimensions (front - rear direction dimension, left - right direction dimension) of the end cap 21 are set to be shorter than the dimensions (front - rear direction dimension, left - right direction dimension) of the column timber 11. Therefore, in a state where the end cap 21 is attached to the column timber 11, the surface (outer surface) of the upright surface portion 21b is located inside (the center side in the front - rear direction and the center side in the left - right direction) of the side surface of the column timber 11. Note that, in a state where the end cap 21 is attached to the column timber 11, for example, the surface (outer surface) of the upright surface portion 21b and the side surface of the column timber 11 may be flush. That is, the dimensions (front - rear direction dimension, left - right direction dimension) of the end cap 21 may be set to be equal to the dimensions (front - rear direction dimension, left - right direction dimension) of the column timber 11.

[0034] Specifically, in this embodiment, the front - rear direction dimension of the end cap 21 is set to 89 mm and the left - right direction dimension of the end cap 21 is set to 89 mm, but it is not limited thereto. In addition, in the present embodiment, the height dimension (vertical dimension) of the wooden base 21 is set to 15 mm, but it is not limited to this. In addition, the wooden base 21 of the present embodiment is formed by bending a plated steel sheet with a thickness of 2.3 mm, but it is not limited to this.

[0035] A first through hole 20a penetrating in the thickness direction (vertical direction) of the bottom surface portion 21a is formed in the bottom surface portion 21a. The first through hole 20a is provided at a position where the center of the first through hole 20a coincides with the center of the bottom surface portion 21a. The diameter of the first through hole 20a is set to a diameter into which the bolts 110 and 120 can be inserted. In the present embodiment, the diameter of the first through hole 20a is set to 24 mm, but it is not limited to this.

[0036] In addition, a plurality (four in the case of the present embodiment) of second through holes 20b penetrating in the thickness direction (vertical direction) of the bottom surface portion 21a are formed in the bottom surface portion 21a. In the present embodiment, the second through holes 20b are provided one by one at four locations: the front left side, the front right side, the rear left side, and the rear right side of the bottom surface portion 21a. The diameter of the second through hole 20b is set to a diameter into which a fixture (for example, a coarse thread) for fixing the wooden base 21 to the column wood 11 can be inserted. In the present embodiment, the diameter of the second through hole 20b is set to 4 mm, but it is not limited to this. In addition, in the present embodiment, countersinking is performed on the second through hole 20b, but it is not limited to this. In addition, in the present embodiment, the protruding dimension of the first bolt 110 (the length dimension of the portion protruding from the wooden base 21) is set to 58 mm, but it is not limited to this. In addition, in the present embodiment, the protruding dimension of the second bolt 120 (the length dimension of the portion protruding from the wooden base 21) is set to 288 mm, but it is not limited to this.

[0037] As shown in FIG. 1, the connection structure 100 includes a second bolt 120 protruding from the lower-story column 1 toward the upper-story column 2, a pair of second nuts 121 screwed onto the second bolt 120, a first bolt 110 protruding from the upper-story column 2 toward the lower-story column 1, a first nut 111 screwed onto the first bolt 110, and a connecting metal fitting 130 provided between the lower-story column 1 and the upper-story column 2.

[0038] FIG. 4 is a diagram showing an example of the connecting metal fitting 130, where (a) is a perspective view, (b) is a plan view, and (c) and (d) are side views. The connecting metal fitting 130 is a box-shaped member having a substantially regular quadrangular prism outer shape. Specifically, the connecting metal fitting 130 includes a square lower surface portion 131 and an upper surface portion 132, and a pair of side surface portions 133 connecting the lower surface portion 131 and the upper surface portion 132. The pair of side surface portions 133 are provided facing each other. Of the pair of side surface portions 133, one side surface portion 133 is provided extending from the left end surface of the lower surface portion 131 to the left end surface of the upper surface portion 132, and the other side surface portion 133 is provided extending from the right end surface of the lower surface portion 131 to the right end surface of the upper surface portion 132. Therefore, the front side surface and the rear side surface among the four side surfaces of the connecting metal fitting 130 are open surfaces.

[0039] A third through hole 131a penetrating in the thickness direction (vertical direction) of the lower surface portion 131 is formed in the lower surface portion 131. The third through hole 131a is provided at a position where the center of the third through hole 131a coincides with the center of the lower surface portion 131. The diameter of the third through hole 131a is set to a diameter into which the second bolt 120 can be inserted. In the present embodiment, the diameter of the third through hole 131a is set to 26 mm, but it is not limited thereto.

[0040] A fourth through hole 132a penetrating in the thickness direction (vertical direction) of the upper surface portion 132 is formed in the upper surface portion 132. The fourth through hole 132a is provided at a position where the center of the fourth through hole 132a coincides with the center of the upper surface portion 132. The diameter of the fourth through-hole 132a is set to a diameter that allows the insertion of the first bolt 110. In the present embodiment, the diameter of the fourth through-hole 132a is set to 26 mm, but it is not limited thereto.

[0041] In the present embodiment, the dimensions (dimensions in the front-rear direction and the left-right direction) of the connecting fitting 130 are set to be shorter than the dimensions (dimensions in the front-rear direction and the left-right direction) of the wooden fitting 21 and the dimensions (dimensions in the front-rear direction and the left-right direction) of the column timber 11. Therefore, in a state where the lower-story column 1 and the upper-story column 2 are connected by the connecting structure 100, the surface (outer surface) of the side surface portion 133 of the connecting fitting 130 is located inside (toward the center in the left-right direction) of the surface (outer surface) of the standing surface portion 21b of the wooden fitting 21 and the side surface of the column timber 11.

[0042] Specifically, in the present embodiment, the dimension of the connecting fitting 130 in the front-rear direction is set to 83 mm, and the dimension of the connecting fitting 130 in the left-right direction is set to 83 mm, but it is not limited thereto. Also, in the present embodiment, the height dimension (dimension in the up-down direction) of the connecting fitting 130 is set to 150 mm, but it is not limited thereto. Also, in the present embodiment, the thickness dimension (dimension in the up-down direction) of the lower surface portion 131 and the upper surface portion 132 of the connecting fitting 130 is set to 12 mm, but it is not limited thereto. Also, in the present embodiment, the thickness dimension (dimension in the left-right direction) of the side surface portion 133 of the connecting fitting 130 is set to 9 mm, but it is not limited thereto.

[0043] In the connecting fitting 130 of the present embodiment, the properties of the lower surface portion 131 and the upper surface portion 132 are different from those of the side surface portion 133. Specifically, the side surface portion 133 has higher stretchability than the lower surface portion 131 and the upper surface portion 132. Therefore, the side surface portion 133 has higher energy absorption performance than the lower surface portion 131 and the upper surface portion 132. Thereby, the connecting structure 100 is made to be able to sufficiently resist horizontal loads such as during an earthquake or a typhoon.

[0044] As shown in FIG. 1, the connecting fitting 130 is fixed to the upper floor column 2 by a first bolt 110 protruding from the upper floor column 2 and a first nut 111 screwed onto the first bolt 110. Specifically, the tip (lower end) of the first bolt 110 protruding from the upper floor column 2 penetrates through a fourth through hole 132a provided in the upper surface portion 132 of the connecting fitting 130, and a first nut 111 located inside the connecting fitting 130 (between the lower surface portion 131 and the upper surface portion 132) is screwed onto the tip via a washer (not shown). Therefore, the upper surface portion 132 of the connecting fitting 130 is sandwiched from above and below by the upper floor column 2 (specifically, the bottom surface portion 21a of the column fitting 21 covering the lower end of the column timber 11) and the first nut 111.

[0045] Also, the connecting fitting 130 is fixed to the lower floor column 1 by a second bolt 120 protruding from the lower floor column 1 and a second nut 121 screwed onto the second bolt 120. Here, an upper floor 3 is provided between the lower floor column 1 and the upper floor column 2. The upper floor 3 is composed of a floor panel 30 and a body difference 31. The floor panel 30 is a building panel. Vertical and horizontal frame members A are assembled in a rectangular shape to form a rectangular frame, and auxiliary cross members are assembled vertically and horizontally inside this rectangular frame to form a frame body, and a facing material C is attached to both sides or one side of this frame body, having an internally hollow structure. Heat insulating materials such as glass wool and rock wool are filled in the internally hollow portion (the back side of the facing material C) as required.

[0046] The upper floor 3 is in contact with the upper end surface of the lower floor column 1 (specifically, the bottom surface portion 21a of the column fitting 21 covering the upper end of the column timber 11). Specifically, the end portion (frame member A) of the floor panel 30 and the body difference 31 are in contact with the upper end surface of the lower floor column 1. A bolt insertion hole 3a penetrating in the thickness direction (vertical direction) of the upper floor 3 is formed in the upper floor 3. The bolt insertion hole 3a is provided at a position corresponding to the second bolt 120 protruding from the lower floor column 1. The dimensions of the bolt insertion hole 3a (the dimension in the front - rear direction and the dimension in the left - right direction) are set to dimensions that allow the second bolt 120 to be inserted.

[0047] On the boundary surface with the body difference 31 in the bed panel 30, a groove portion is provided along the thickness direction (vertical direction) of the bed panel 30. Also, on the boundary surface of the body difference 31 with the bed panel 30, a groove portion is provided along the thickness direction (vertical direction) of the body difference 31. And the bolt insertion hole 3a is formed by combining these groove portions. In the present embodiment, the dimensions (front - rear direction dimension, left - right direction dimension) of the groove portions provided in the bed panel 30 (specifically, the frame member A and the face member C), and the dimensions (front - rear direction dimension, left - right direction dimension) of the groove portions provided in the body difference 31 are set to 36×18 mm, but it is not limited thereto. That is, in the present embodiment, the dimensions (front - rear direction dimension, left - right direction dimension) of the bolt insertion hole 3a are set to 36×36 mm, but it is not limited thereto.

[0048] The protruding portion of the second bolt 120 protruding from the lower - story column 1 (the portion protruding from the wooden fitting 21) penetrates through the bolt insertion hole 3a of the upper - story floor 3. Therefore, the upper - end portion (the tip of the protruding portion) of the second bolt 120 protruding from the lower - story column 1 is located above the upper - story floor 3 (on the side of the upper - story column 2). And the upper - end portion of the second bolt 120 protruding from the lower - story column 1 penetrates through the third through - hole 131a provided in the lower - surface portion 131 of the connecting fitting 130. A second nut 121 located between the upper - story floor 3 and the connecting fitting 130 is screwed onto the upper - end portion via a washer (not shown), and a second nut 121 located inside the connecting fitting 130 (between the lower - surface portion 131 and the upper - surface portion 132) is also screwed onto the upper - end portion via a washer (not shown). Therefore, the lower - surface portion 131 of the connecting fitting 130 is sandwiched from above and below by the second nut 121 located between the lower - surface portion 131 and the upper - story floor 3 and the second nut 121 located between the lower - surface portion 131 and the upper - surface portion 132.

[0049] In the connection structure 100, among the pair of second nuts 121, the upper second nut 121 (the second nut 121 located between the lower surface portion 131 and the upper surface portion 132) can resist an upward force (a force in the direction of pulling out the connecting hardware 130), and the lower second nut 121 (the second nut 121 located between the lower surface portion 131 and the upper floor 3) can resist a downward force (a force in the direction of pushing the connecting hardware 130). For example, if only the upper second nut 121 is provided without providing the lower second nut 121 and the connecting hardware 130 is in contact with the upper floor 3, a downward force is transmitted through the connecting hardware 130, and there is a risk of indentation in the upper floor 3 and the lower floor column 1. On the contrary, as in this embodiment, the lower second nut 121 is provided at a position away from the upper floor 3, and the lower second nut 121 supports the connecting hardware 130 from below to resist the downward force, thereby preventing indentation in the upper floor 3 and the lower floor column 1.

[0050] [Connection method] Next, a method of connecting the lower floor column 1 and the upper floor column 2 using the connection structure 100 will be described. First, install the lower floor column 1 with the second bolt 120 protruding (lower floor column installation step). Next, install the upper floor 3 (upper floor installation step). At this time, insert the second bolt 120 protruding from the lower floor column 1 into the bolt insertion hole 3a of the upper floor 3. Next, screw the lower second nut 121 onto the second bolt 120 protruding from the lower floor column 1 and attach a washer (lower nut attachment step). Also, fix the connecting hardware 130 to the upper floor column 2 with the first bolt 110 protruding (connecting hardware fixing step). Specifically, insert the first bolt 110 protruding from the upper floor column 2 into the fourth through hole 132a of the upper surface portion 132 in the connecting hardware 130, and attach a washer from the opening (front opening or rear opening) of the connecting hardware 130 to the first bolt 110 and screw in the first nut 111.

[0051] Next, the upper floor column 2 to which the connecting fitting 130 is fixed is arranged above the lower floor column 1 (upper floor column arranging step). At this time, until the lower surface portion 131 of the connecting fitting 130 contacts the lower second nut 121 that is screwed onto the second bolt 120 protruding from the lower floor column 1, the second bolt 120 is inserted into the third through hole 131a of the lower surface portion 131. In the present embodiment, the lower second nut 121 is screwed in the lower nut mounting step until the dimension between the connecting fitting 130 and the upper floor 3 at the end of the upper floor column arranging step becomes a dimension (for example, 40 mm) shorter than the design dimension (for example, 50 mm).

[0052] Next, a washer is attached to the second bolt 120 protruding from the lower floor column 1 through the opening (front side opening or rear side opening) of the connecting fitting 130, and the upper second nut 121 is screwed in (upper nut mounting step). Finally, the positions of the lower second nut 121 and the upper second nut 121 screwed onto the second bolt 120 protruding from the lower floor column 1 are adjusted so that the dimension between the connecting fitting 130 and the upper floor 3 becomes the design dimension (for example, 50 mm) (adjusting step). As described above, the lower floor column 1 and the upper floor column 2 can be connected using the connecting structure 100.

[0053] <Modification Example> Next, a modification example of the first embodiment will be described. For the sake of convenience of explanation, elements common to the above first embodiment are denoted by common reference numerals, and the description thereof is omitted or simplified.

[0054] <<First Modification Example>> FIG. 5 is a longitudinal sectional view showing an example of the connecting structure 100 in the first modification example. FIG. 6 is a view showing an example of a column in the first modification example, and shows the lower floor column 1 in a state where the bolts 110 and 120 protrude. FIG. 7 is a view showing an example of the end fitting 22 in the first modification example, (a) is a plan view, and (b) is a longitudinal sectional view. In the first embodiment, the lower-story column 1 and the upper-story column 2 with the same cross-sectional dimensions are connected by the connecting structure 100, but it is not limited thereto. For example, the lower-story column 1 and the upper-story column 2 with different cross-sectional dimensions may be connected by the connecting structure 100. That is, as shown in FIG. 5, the connecting structure 100 in the first embodiment is applicable even when the cross-sectional dimension of the lower-story column 1 is different from the cross-sectional dimension of the upper-story column 2.

[0055] The upper-story column 2 in the first modification is configured to include a column timber 11, a wood base member 21 that covers the lower end portion of the column timber 11, and a wood base member 21 that covers the upper end portion of the column timber 11. That is, the upper-story column 2 in the first modification is the same as the upper-story column 2 in the first embodiment. On the other hand, the lower-story column 1 in the first modification is configured to include a column timber 12 thicker than the column timber 11, a wood base member 22 that covers the lower end portion of the column timber 12, and a wood base member 22 that covers the upper end portion of the column timber 12. In this modification, the cross-sectional dimension of the column timber 12 is set to 120×120 mm, but it is not limited thereto. Similar to the column timber 11, four notch portions 10a that are continuously connected in an L-shape are provided at the upper end portion of the column timber 12, and four notch portions 10a that are continuously connected in an L-shape are provided at the lower end portion of the column timber 12.

[0056] In the first modification, similar to the first embodiment, the outdoor side surface (right side surface) among the four side surfaces of the lower-story column 1 and the outdoor side surface (right side surface) among the four side surfaces of the upper-story column 2 are aligned (that is, the outdoor side surface of the upper-story column 2 is located on the extension line of the outdoor side surface of the lower-story column 1). Therefore, the embedding positions of the bolts 110 and 120 with respect to the column timber 12 are set at positions where this can be realized. Specifically, as shown in FIGS. 5 and 6, the second bolt 120 is embedded in the column timber 12 of the lower-story column 1 in the first modification at a position where the center line of the second bolt 120 does not coincide with the center line of the column timber 12.

[0057] Specifically, in the upper-story column 2 of the first modification example, similar to the lower-story column 1 and the upper-story column 2 of the first embodiment, the first bolt 110 is inserted into the lower end portion of the column timber 11 with the center line of the first bolt 110 and the center line of the column timber 11 being in alignment, and the second bolt 120 is inserted into the upper end portion of the column timber 11 with the center line of the second bolt 120 and the center line of the column timber 11 being in alignment. On the other hand, in the lower-story column 1 of the first modification example, the first bolt 110 is inserted into the lower end portion of the column timber 12 with the center line of the first bolt 110 and the center line of the column timber 12 not being in alignment, and the second bolt 120 is inserted into the upper end portion of the column timber 12 with the center line of the second bolt 120 and the center line of the column timber 12 not being in alignment.

[0058] Therefore, as shown in FIG. 7, in the wood fitting 22 of the lower-story column 1 in the first modification example, the first through hole 20a is provided at a position where the center of the first through hole 20a and the center of the bottom surface portion 22a do not coincide. Note that the embedding positions of the bolts 110 and 120 with respect to the column timber 12 of the lower-story column 1 are not limited to the positions shown in FIGS. 5 and 6. Also, the position of the first through hole 20a in the wood fitting 22 of the lower-story column 1 is not limited to the positions shown in FIGS. 5 to 7. In the case of the wood fitting 22 that covers the lower end portion of the column timber 12, the position of the first through hole 20a can be appropriately set according to the position of the first bolt 110 with respect to the lower end surface of the column timber 12. Also, in the case of the wood fitting 22 that covers the upper end portion of the column timber 12, the position of the first through hole 20a can be appropriately set according to the position of the second bolt 120 with respect to the upper end surface of the column timber 12.

[0059] The wood fitting 22 of the lower-story column 1 in the first modification example is a member for preventing the splitting of the column timber 12 and has a U-shaped longitudinal cross section. Specifically, the wood fitting 22 includes a substantially square bottom surface portion 22a and upright surface portions 22b that stand up from the four end portions of the bottom surface portion 22a, respectively. In a state where the wooden fitting 22 is attached to the column timber 12, the bottom surface portion 22a of the wooden fitting 22 contacts the end surface of the column timber 12 (when the wooden fitting 22 covers the lower end of the column timber 12, it is the lower end surface, and when the wooden fitting 22 covers the upper end of the column timber 12, it is the upper end surface), and the standing surface portion 22b of the wooden fitting 22 is disposed within the notch portion 10a of the column timber 12.

[0060] In this modified example, the dimension in the front - rear direction of the wooden fitting 22 is set to 119 mm, and the dimension in the left - right direction of the wooden fitting 22 is set to 119 mm, but it is not limited to this. Also, in this modified example, the height dimension (dimension in the up - down direction) of the wooden fitting 22 is set to 15 mm, but it is not limited to this. Also, the wooden fitting 22 of this modified example is formed by bending a plated steel sheet with a thickness of 2.3 mm, but it is not limited to this.

[0061] As shown in FIG. 5, the connection structure 100 in the first modified example, similar to the connection structure 100 in the first embodiment, includes a second bolt 120 protruding from the lower - story column 1 toward the upper - story column 2, a pair of second nuts 121 screwed onto the second bolt 120, a first bolt 110 protruding from the upper - story column 2 toward the lower - story column 1, a first nut 111 screwed onto the first bolt 110, and a connecting fitting 130 provided between the lower - story column 1 and the upper - story column 2.

[0062] The lower - story column 1 in the first modified example is thicker than the lower - story column 1 in the first embodiment. Accordingly, the body difference 32 of the upper - story floor 3 in the first modified example has a longer thickness dimension (dimension in the left - right direction) than the body difference 31 of the upper - story floor 3 in the first embodiment. Specifically, the lower - story column 1 in the first embodiment has a dimension in the left - right direction of 90 mm, and the lower - story column 1 in the first modified example has a dimension in the left - right direction of 120 mm. And the body difference 31 in the first embodiment has a dimension in the left - right direction of 45 mm, and the body difference 32 in the first modified example has a dimension in the left - right direction of 75 mm. Also, in the first modification example, as shown in FIG. 5, the through hole provided in the body difference 32 is the bolt insertion hole 3a of the upper floor 3.

[0063] 《Second Modification Example》 FIG. 8 is a longitudinal sectional view showing an example of the connection structure 100 in the second modification example. FIG. 9 is a view showing an example of a column in the second modification example, and shows the lower floor column 1 and the upper floor column 2 in a state where bolts 110 and 120 are protruding. In the first modification example, as the lower floor column 1, a column thicker than the lower floor column 1 in the first embodiment is used, and as the upper floor column 2, a column having the same thickness as the upper floor column 2 in the first embodiment is used. However, the present invention is not limited to this. For example, as the lower floor column 1, a column thicker than the lower floor column 1 in the first embodiment may be used, and as the upper floor column 2, a column thicker than the upper floor column 2 in the first embodiment may be used. That is, the connection structure 100 in the first embodiment is applicable not only when the cross-sectional dimensions of the lower floor column 1 and the upper floor column 2 are 90×90 mm, but also when the cross-sectional dimensions of the lower floor column 1 and the upper floor column 2 are larger than 90×90 mm (for example, 120×120 mm) as shown in FIG. 8.

[0064] The upper floor column 2 in the second modification example includes a column timber 12 thicker than the column timber 11, a wooden cap 22 covering the lower end portion of the column timber 12, and a wooden cap 22 covering the upper end portion of the column timber 12. That is, the upper floor column 2 in the second modification example is the same as the lower floor column 1 in the first modification example. Also, the lower floor column 1 in the second modification example includes a column timber 12 thicker than the column timber 11, a wooden cap 22 covering the lower end portion of the column timber 12, and a wooden cap 22 covering the upper end portion of the column timber 12. That is, the lower floor column 1 in the second modification example is the same as the lower floor column 1 in the first modification example.

[0065] In the second modification example, similar to the first modification example, the outdoor side surface (right side surface) among the four side surfaces of the lower floor column 1 and the outdoor side surface (right side surface) among the four side surfaces of the upper floor column 2 are aligned (that is, the outdoor side surface of the upper floor column 2 is located on the extension line of the outdoor side surface of the lower floor column 1). Also, in the second modification example, similar to the first modification example, the body difference 32 of the upper floor 3 is thicker than the body difference 31 in the first embodiment. On the other hand, in the second modification example, different from the first modification example, the bolt insertion holes 3a are formed by combining the groove portion provided at the boundary surface with the body difference 32 in the floor panel 30 and the groove portion provided at the boundary surface with the floor panel 30 in the body difference 32 (see Fig. 8).

[0066] Therefore, the positions where the outdoor side surface of the lower floor column 1 and the outdoor side surface of the upper floor column 2 are aligned, and the bolt insertion holes 3a are formed by combining the groove portion of the floor panel 30 and the groove portion of the body difference 32, are set at positions where both can be realized. The embedding positions of the bolts 110 and 120 with respect to the column timber 12 of the lower floor column 1 and the embedding positions of the bolts 110 and 120 with respect to the column timber 12 of the upper floor column 2 are set (see Figs. 8 and 9).

[0067] Note that the embedding positions of the bolts 110 and 120 with respect to the column timber 12 of the lower floor column 1 are not limited to the positions shown in Figs. 8 and 9. Also, the embedding positions of the bolts 110 and 120 with respect to the column timber 12 of the upper floor column 2 are not limited to the positions shown in Figs. 8 and 9. Also, the position of the first through hole 20a in the wooden fitting 22 of the lower floor column 1 is not limited to the position shown in Figs. 8 and 9. Also, the position of the first through hole 20a in the wooden fitting 22 of the upper floor column 2 is not limited to the position shown in Figs. 8 and 9. Also, the position of the bolt insertion hole 3a in the upper floor 3 is not limited to the position shown in Fig. 8. For example, the position of the bolt insertion hole 3a in the upper floor 3 may be the same as that in the first modification example.

[0068] As shown in Fig. 8, the connection structure 100 in the second modification is the same as the connection structure 100 in the first embodiment, and includes a second bolt 120 protruding from the lower column 1 toward the upper column 2, a pair of second nuts 121 screwed onto the second bolt 120, a first bolt 110 protruding from the upper column 2 toward the lower column 1, a first nut 111 screwed onto the first bolt 110, and a connecting fitting 130 provided between the lower column 1 and the upper column 2.

[0069] <<Third Modification>> Fig. 10 is a view showing an example of a column in the third modification, and shows the lower column 1 and the upper column 2 in a state where the bolts 110 and 120 are protruding. Fig. 11 is a view showing an example of the end fitting 23 in the third modification, where (a) is a plan view and (b) is a longitudinal sectional view. In the first embodiment, columns having a square cross-section were used as the lower column 1 and the upper column 2, but the present invention is not limited thereto. For example, at least one of the lower column 1 and the upper column 2 may be a column having a rectangular cross-section. That is, the connection structure 100 in the first embodiment is applicable not only when the lower column 1 and the upper column 2 have a square cross-section, but also when one of the lower column 1 and the upper column 2 has a square cross-section and the other has a rectangular cross-section, or when the lower column 1 and the upper column 2 have a rectangular cross-section. In the present application, a rectangle does not include a square.

[0070] The lower column 1 in the third modification includes a column timber 13, an end fitting 23 covering the lower end portion of the column timber 13, and an end fitting 23 covering the upper end portion of the column timber 13. The upper column 2 in the third modification includes a column timber 13, an end fitting 23 covering the lower end portion of the column timber 13, and an end fitting 23 covering the upper end portion of the column timber 13.

[0071] The column timber 13 has a rectangular cross-section. In this modified example, the dimension of the column timber 13 in the left-right direction is set to 120 mm, and the dimension of the column timber 13 in the front-back direction is set to 90 mm. That is, in this modified example, the cross-sectional dimension of the column timber 13 is set to 120×90 mm, but it is not limited to this. Also, the dimension of the column timber 13 in the left-right direction may be shorter than the dimension of the column timber 13 in the front-back direction. Similar to the column timbers 11 and 12, four notch portions 10a connected in an L-shape are provided at the upper end portion of the column timber 13, and four notch portions 10a connected in an L-shape are provided at the lower end portion of the column timber 13.

[0072] The wooden fitting 23 is a member for preventing the column timber 13 from splitting, and has a U-shaped longitudinal cross-section. Specifically, the wooden fitting 23 includes a substantially rectangular bottom surface portion 23a and upright surface portions 23b standing from the four end portions of the bottom surface portion 23a. In a state where the wooden fitting 23 is attached to the column timber 13, the bottom surface portion 23a of the wooden fitting 23 contacts the end surface of the column timber 13 (the lower end surface when the wooden fitting 23 is a fitting covering the lower end portion of the column timber 13, and the upper end surface when the wooden fitting 23 is a fitting covering the upper end portion of the column timber 13), and the upright surface portions 23b of the wooden fitting 23 are disposed within the notch portions 10a of the column timber 13.

[0073] In this modified example, the dimension of the wooden fitting 23 in the front-back direction is set to 89 mm, and the dimension of the wooden fitting 23 in the left-right direction is set to 119 mm, but it is not limited to this. Also, in this modified example, the height dimension (dimension in the up-down direction) of the wooden fitting 23 is set to 15 mm, but it is not limited to this. Also, the wooden fitting 23 of this modified example is formed by bending a plated steel sheet with a thickness of 2.3 mm, but it is not limited to this.

[0074] In the third modification, similar to the first embodiment, the outdoor side surface (right side surface) among the four side surfaces of the lower floor column 1 and the outdoor side surface (right side surface) among the four side surfaces of the upper floor column 2 are aligned (that is, the outdoor side surface of the upper floor column 2 is located on the extension line of the outdoor side surface of the lower floor column 1). Therefore, the embedding positions of the bolts 110 and 120 with respect to the column timber 13 of the lower floor column 1 and the embedding positions of the bolts 110 and 120 with respect to the column timber 13 of the upper floor column 2 are set at positions where this can be realized (see Fig. 10).

[0075] Note that the embedding positions of the bolts 110 and 120 with respect to the column timber 13 of the lower floor column 1 are not limited to the positions shown in Fig. 10. Also, the embedding positions of the bolts 110 and 120 with respect to the column timber 13 of the upper floor column 2 are not limited to the positions shown in Fig. 10. Also, the position of the first through hole 20a in the wooden fitting 23 of the lower floor column 1 is not limited to the position shown in Fig. 11. Also, the position of the first through hole 20a in the wooden fitting 23 of the upper floor column 2 is not limited to the position shown in Fig. 11.

[0076] Although illustration is omitted, the connection structure 100 in the third modification, similar to the connection structure 100 in the first embodiment, includes a second bolt 120 protruding from the lower floor column 1 toward the upper floor column 2, a pair of second nuts 121 screwed onto the second bolt 120, a first bolt 110 protruding from the upper floor column 2 toward the lower floor column 1, a first nut 111 screwed onto the first bolt 110, and a connecting fitting 130 provided between the lower floor column 1 and the upper floor column 2.

[0077] 《Effect》 According to the first embodiment (including the modifications), the following excellent effects are achieved. The connection structure 100 of the first embodiment is a connection structure that connects the lower-story column 1 and the upper-story column 2, and includes a connection fitting 130 provided between the lower-story column 1 and the upper-story column 2, a second bolt 120 protruding from the lower-story column 1 toward the upper-story column 2, and a pair of second nuts 121 screwed onto the second bolt 120. The connection fitting 130 includes a lower surface portion 131 through which the second bolt 120 passes and an upper surface portion 132 fixed to the upper-story column 2. The lower surface portion 131 is sandwiched from above and below by a pair of second nuts 121 screwed onto the second bolt 120.

[0078] That is, in the connection structure 100, among the pair of second nuts 121, the upper second nut 121 can resist upward forces, and the lower second nut 121 can resist downward forces. Therefore, since the lower second nut 121 can resist downward forces (support the load from the upper-story column 2), it is possible to avoid indentation into other building structure members (the upper floor 3 and the lower-story column 1), making it suitable for mid- to high-rise buildings.

[0079] Also, in the connection structure 100 of the first embodiment, the connection fitting 130 can be configured to include a lower surface portion 131, an upper surface portion 132, and a side surface portion 133 that connects the lower surface portion 131 and the upper surface portion 132, and the side surface portion 133 can be made more extensible than the lower surface portion 131 and the upper surface portion 132. By configuring it in this way, the energy absorption performance of the side surface portion 133 becomes higher than the energy absorption performance of the lower surface portion 131 and the upper surface portion 132. Therefore, it is possible to sufficiently resist horizontal loads during earthquakes, typhoons, etc., making it suitable for mid- to high-rise buildings.

[0080] Further, in the connection structure 100 of the first embodiment, the upper floor column 2 can be configured to include column timbers 11, 12, 13 and wooden caps 21, 22, 23 that cover both the upper and lower ends of the column timbers 11, 12, 13. Similarly, the lower floor column 1 can be configured to include column timbers 11, 12, 13 and wooden caps 21, 22, 23 that cover both the upper and lower ends of the column timbers 11, 12, 13. By configuring in this way, splitting of the column timbers 11, 12, 13 can be prevented. Moreover, by configuring in this way, wooden columns can be used as the lower floor column 1 and the upper floor column 2, which enables contribution to the realization of a decarbonized society through the promotion of carbon neutrality and the achievement of the SDGs goals. In recent years, there has been a demand for the realization of a decarbonized society through the promotion of carbon neutrality, which aims to substantially reduce carbon dioxide emissions to zero, and the achievement of the SDGs goals. In the construction industry, efforts are underway to use wooden buildings with low carbon dioxide emissions. Since the connection structure 100 in the first embodiment is a structure for connecting wooden columns, it can contribute to the realization of a decarbonized society through the promotion of carbon neutrality and also contribute to the achievement of SDGs Goal 7, "Ensure access to affordable, reliable, sustainable and modern energy for all," and Goal 13, "Take urgent action to combat climate change and its impacts."

[0081] <Second Embodiment> Next, the second embodiment of the present invention will be described. For the sake of convenience in explanation, elements common to the above first embodiment (including modifications) will be denoted by common reference numerals, and the description will be omitted or simplified. In the second embodiment, the lower floor column 1 is different from that in the first embodiment. Specifically, the lower floor column 1 in the first embodiment is configured to include one column timber 11 (it may also be column timber 12 or column timber 13). In contrast, the lower floor column 1 in the second embodiment is configured to include a plurality of column timbers 12 (it may also be column timber 11 or column timber 13).

[0082] [Connection Structure] FIG. 12 is a longitudinal sectional view showing an example of the connection structure 200 in the second embodiment. The connection structure 200 is a structure for connecting the lower-story column 1 and the upper-story column 2 in a building, and is provided in a multi-story building. The upper-story column 2 includes a single column timber 12, a wooden base member 22 covering the lower end portion of the column timber 12, and a wooden base member 22 covering the upper end portion of the column timber 12. That is, the upper-story column 2 in the second embodiment is the same as the upper-story column 2 in the second modification (see FIG. 8). Note that the column timber constituting the upper-story column 2 in the second embodiment may be any of the column timbers 11, 12, and 13.

[0083] The lower-story column 1 includes two column timbers 12 arranged side by side, a wooden base member 22 covering the lower end portion of the left column timber 12, a wooden base member 22 covering the upper end portion of the left column timber 12, a wooden base member 22 covering the lower end portion of the right column timber 12, a wooden base member 22 covering the upper end portion of the right column timber 12, and a transmission member 40 provided across the two column timbers 12. Note that in the lower-story column 1 of the present embodiment, the two column timbers 12 are joined with an adhesive, but the present invention is not limited thereto. In addition, the number of column timbers constituting the lower-story column 1 in the second embodiment is not limited to two, and may be three or more. Also, the column timber constituting the lower-story column 1 in the second embodiment may be any of the column timbers 11, 12, and 13.

[0084] In the lower-story column 1 of the present embodiment, a third bolt 140 instead of the second bolt 120 is inserted into the bolt insertion hole at the upper end portion of the column timber 12. The third bolt 140 is a fully threaded bolt. In the present embodiment, the column timber 12 and the third bolt 140 are joined by steel bar insertion and adhesive bonding, but the present invention is not limited thereto. In addition, in this embodiment, the embedding depth of the third bolt 140 (the depth of the bolt insertion hole formed in the upper end portion of the column timber 12) is set to 800 mm, but it is not limited thereto. In addition, in this embodiment, the diameter (nominal diameter) of the third bolt 140 is set to 24 mm, but it is not limited thereto. In addition, in this embodiment, the protruding dimension of the third bolt 140 (the length dimension of the portion protruding from the wooden fitting 22) is set to 62 mm, but it is not limited thereto.

[0085] FIG. 13 is a diagram showing an example of the transmission member 40, where (a) is a perspective view, (b) is a plan view, (c) is a side view, and (d) is a longitudinal sectional view. The transmission member 40 includes two connecting fittings 130 arranged side by side and a plate-shaped fitting 41 that connects the connecting fittings 130 to each other. The plate-shaped fitting 41 is provided from the central portion in the front-rear direction of the right side surface portion 133 of the left connecting fitting 130 to the central portion in the front-rear direction of the left side surface portion 133 of the right connecting fitting 130.

[0086] In this embodiment, the height dimension (dimension in the vertical direction) of the plate-shaped fitting 41 is set to 140 mm, but it is not limited thereto. In addition, in this embodiment, the thickness dimension (dimension in the front-rear direction) of the plate-shaped fitting 41 is set to 12 mm, but it is not limited thereto. In addition, in this embodiment, the width dimension (dimension in the left-right direction) of the plate-shaped fitting 41 is set to 37 mm, but it is not limited thereto. Also, the number of the connecting fittings 130 constituting the transmission member 40 is not limited to two, and may be three or more. It is preferable that the number of the connecting fittings 130 constituting the transmission member 40 is the same as the number of the column timbers 12 constituting the lower column 1.

[0087] As described above, in the connecting fitting 130, the properties of the lower surface portion 131 and the upper surface portion 132 are different from those of the side surface portion 133. Specifically, the side surface portion 133 has higher stretchability than the lower surface portion 131 and the upper surface portion 132. Therefore, the side surface portion 133 has higher energy absorption performance than the lower surface portion 131 and the upper surface portion 132. Therefore, also in the connecting fitting 130 that constitutes the transmission member 40, the stretchability of the side surface portion 133 is higher than the stretchability of the lower surface portion 131 and the upper surface portion 132. Furthermore, in the transmission member 40, the stretchability of the plate-shaped fitting 41 is higher than the stretchability of the lower surface portion 131 and the upper surface portion 132. Due to these, the connection structure 200 is configured to be able to sufficiently resist horizontal loads such as during an earthquake or a typhoon.

[0088] As shown in FIG. 12, the connection structure 200, similar to the connection structure 100 in the first embodiment, includes a second bolt 120 protruding from the lower-story column 1 toward the upper-story column 2, a pair of second nuts 121 screwed onto the upper end portion of the second bolt 120, a first bolt 110 protruding from the upper-story column 2 toward the lower-story column 1, a first nut 111 screwed onto the first bolt 110, and a connecting fitting 130 provided between the lower-story column 1 and the upper-story column 2. Furthermore, different from the connection structure 100 in the first embodiment, the connection structure 200 includes a transmission member 40 that constitutes the upper end portion of the lower-story column 1, a third bolt 140 protruding from the column timber 12 that constitutes the lower-story column 1 toward the upper-story column 2, a third nut 141 screwed onto the third bolt 140, and a pair of fourth nuts 122 screwed onto the lower end portion of the second bolt 120.

[0089] The transmission member 40 is fixed across the left and right column timbers 12 in the lower-story column 1 by a third bolt 140 protruding from the column timber 12 of the lower-story column 1 and a third nut 141 screwed onto the third bolt 140. Specifically, the tip (upper end) of the third bolt 140 protruding from the left pillar wood 12 in the lower floor column 1 passes through the third through-hole 131a provided in the lower surface portion 131 of the left connecting metal fitting 130 in the transmission member 40. A third nut 141 located inside the left connecting metal fitting 130 (between the lower surface portion 131 and the upper surface portion 132) is screwed onto the tip through a washer (not shown). Therefore, the lower surface portion 131 of the left connecting metal fitting 130 is sandwiched from above and below by the left pillar wood 12 in the lower floor column 1 (specifically, the bottom surface portion 22a of the wood cap 22 covering the upper end of the left pillar wood 12) and the third nut 141. Also, the tip (upper end) of the third bolt 140 protruding from the right pillar wood 12 in the lower floor column 1 passes through the third through-hole 131a provided in the lower surface portion 131 of the right connecting metal fitting 130 in the transmission member 40. A third nut 141 located inside the right connecting metal fitting 130 (between the lower surface portion 131 and the upper surface portion 132) is screwed onto the tip through a washer (not shown). Therefore, the lower surface portion 131 of the right connecting metal fitting 130 is sandwiched from above and below by the right pillar wood 12 in the lower floor column 1 (specifically, the bottom surface portion 22a of the wood cap 22 covering the upper end of the right pillar wood 12) and the third nut 141.

[0090] Further, the second bolt 120 is fixed to the transmission member 40 by a pair of fourth nuts 122 screwed onto the lower end of the second bolt 120, and thus protrudes from the lower floor column 1. Specifically, the lower end portion of the second bolt 120 penetrates through a fourth through-hole 132a provided on the upper surface portion 132 of one of the connecting metal fittings 130 (the right connecting metal fitting 130 in this embodiment) in the transmission member 40. A fourth nut 122 positioned between one of the connecting metal fittings 130 and the upper floor 3 is screwed via a washer (not shown) to the lower end portion, and a fourth nut 122 positioned within one of the connecting metal fittings 130 (between the lower surface portion 131 and the upper surface portion 132) is also screwed via a washer (not shown). Therefore, the upper surface portion 132 of one of the connecting metal fittings 130 is sandwiched from above and below by the fourth nut 122 positioned between the upper surface portion 132 and the upper floor 3 and the fourth nut 122 positioned between the upper surface portion 132 and the lower surface portion 131.

[0091] Further, the connecting metal fitting 130 is fixed to the upper floor column 2 by a first bolt 110 protruding from the upper floor column 2 and a first nut 111 screwed to the first bolt 110. Specifically, the tip portion (lower end portion) of the first bolt 110 protruding from the upper floor column 2 penetrates through a fourth through-hole 132a provided on the upper surface portion 132 of the connecting metal fitting 130. A first nut 111 positioned within the connecting metal fitting 130 (between the lower surface portion 131 and the upper surface portion 132) is screwed to the tip portion via a washer (not shown). Therefore, the upper surface portion 132 of the connecting metal fitting 130 is sandwiched from above and below by the upper floor column 2 (specifically, the bottom surface portion 22a of the wood fitting 22 covering the lower end portion of the column timber 12) and the first nut 111.

[0092] Also, the connecting metal fitting 130 is fixed to the lower floor column 1 by a second bolt 120 protruding from the lower floor column 1 and a second nut 121 screwed to the second bolt 120. Specifically, the protruding portion of the second bolt 120 protruding from the lower floor column 1 (the portion protruding from the wood fitting 22) penetrates through the bolt insertion hole 3a of the upper floor 3. Therefore, the upper end portion (the tip portion of the protruding portion) of the second bolt 120 protruding from the lower floor column 1 is positioned above the upper floor 3 (on the side of the upper floor column 2). And the upper end of the second bolt 120 protruding from the lower floor column 1 penetrates through the third through hole 131a provided in the lower surface portion 131 of the connecting fitting 130. A second nut 121 positioned between the upper floor 3 and the connecting fitting 130 is screwed onto the upper end through a washer (not shown), and a second nut 121 positioned inside the connecting fitting 130 (between the lower surface portion 131 and the upper surface portion 132) is screwed through a washer (not shown). Therefore, the lower surface portion 131 of the connecting fitting 130 is sandwiched from above and below by the second nut 121 positioned between the lower surface portion 131 and the upper floor 3 and the second nut 121 positioned between the lower surface portion 131 and the upper surface portion 132.

[0093] In the connecting structure 200, among the pair of second nuts 121, the upper second nut 121 (the second nut 121 positioned between the lower surface portion 131 and the upper surface portion 132) can resist an upward force (a force in the direction of pulling out the connecting fitting 130), and the lower second nut 121 (the second nut 121 positioned between the lower surface portion 131 and the upper floor 3) can resist a downward force (a force in the direction of pushing the connecting fitting 130). For example, if only the upper second nut 121 is provided without providing the lower second nut 121 and the connecting fitting 130 is in contact with the upper floor 3, a downward force may be transmitted through the connecting fitting 130, causing the upper floor 3 and the lower floor column 1 to sink. On the contrary, as in this embodiment, by providing the lower second nut 121 at a position away from the upper floor 3 and supporting the connecting fitting 130 from below with the lower second nut 121 to resist the downward force, it is possible to prevent the upper floor 3 and the lower floor column 1 from sinking.

[0094] Furthermore, in the connecting structure 200, the load (downward force) from the upper floor column 2 can be dispersed to the two column timbers 12 constituting the lower floor column 1 by the transmission member 40. Specifically, the load from the upper-story column 2 is transmitted to the right connection fitting 130 (one connection fitting 130) in the transmission member 40 via the second bolt 120. Then, the force transmitted to the right connection fitting 130 is transmitted to the right column timber 12 (one column timber 12) via the right connection fitting 130, and is also transmitted to the left column timber 12 (the other column timber 12) via the right connection fitting 130, the plate-shaped fitting 41, and the left connection fitting 130 (the other connection fitting 130). This makes it possible to prevent the lower-story column 1 (especially the right column timber 12) from being recessed.

[0095] Since the lower-story column 1 in the second embodiment is thicker than the lower-story column 1 in the first modification or the second modification, accordingly, the thickness dimension (the dimension in the left-right direction) of the column difference in the upper-story floor 3 is longer than the column difference 32 in the first modification or the second modification. Specifically, the upper-story floor 3 in the second embodiment includes, as the column difference, the column difference 32 in the first modification or the second modification, and an indoor-side column difference 33 located between the column difference 32 (outdoor-side column difference) and the floor panel 30. In this embodiment, although the dimension in the left-right direction of the outdoor-side column difference (column difference 32) is set to 75 mm, it is not limited thereto. Also, in this embodiment, although the dimension in the left-right direction of the indoor-side column difference 33 is set to 120 mm, it is not limited thereto.

[0096] In the second embodiment, similar to the first embodiment, the outdoor-side surface among the four side surfaces of the lower-story column 1 (the right-side surface of the right column timber 12) and the outdoor-side surface among the four side surfaces of the upper-story column 2 (the right-side surface) are aligned (that is, the outdoor-side surface of the upper-story column 2 is located on the extension line of the outdoor-side surface of the lower-story column 1). Also, in the second embodiment, the bolt insertion hole 3a is formed by combining the groove provided at the boundary surface between the outdoor-side column difference (column difference 32) and the indoor-side column difference 33 in the indoor-side column difference 33 and the groove provided at the boundary surface between the indoor-side column difference 33 and the outdoor-side column difference (column difference 32) in the outdoor-side column difference (see FIG. 12).

[0097] Therefore, the positions are set such that the outdoor side surfaces of the lower floor column 1 and the upper floor column 2 are aligned, and a bolt insertion hole 3a is formed by combining the groove portion of the indoor side body difference 33 and the groove portion of the outdoor side body difference (body difference 32), specifically, the embedding position of the third bolt 140 with respect to the column timber 12 of the lower floor column 1 and the embedding position of the first bolt 110 with respect to the column timber 12 of the upper floor column 2 (see Fig. 12).

[0098] Note that the embedding position of the third bolt 140 with respect to the column timber 12 of the lower floor column 1 is not limited to the position shown in Fig. 12. Also, the embedding position of the first bolt 110 with respect to the column timber 12 of the upper floor column 2 is not limited to the position shown in Fig. 12. Also, the position of the first through hole 20a in the wooden fitting 22 of the lower floor column 1 is not limited to the position shown in Fig. 12. Also, the position of the first through hole 20a in the wooden fitting 22 of the upper floor column 2 is not limited to the position shown in Fig. 12. Also, the position of the bolt insertion hole 3a in the upper floor 3 is not limited to the position shown in Fig. 12.

[0099] [Connection method] Next, a method for connecting the lower floor column 1 and the upper floor column 2 using the connection structure 200 will be described. First, a transmission member 40 is fixed to the two column timbers 12 constituting the lower floor column 1 (transmission member fixing step). Specifically, the third bolt 140 is inserted into the upper end portions of the two column timbers 12, and the wooden fittings 22 are attached to the upper and lower end portions of the two column timbers 12, and the two column timbers 12 are joined with an adhesive. Then, the third bolt 140 protruding from the column timber 12 is inserted into the third through hole 131a of the lower surface portion 131 of the connection fitting 130 constituting the transmission member 40, and a washer is attached to the third bolt 140 from the opening (front opening or rear opening) of the connection fitting 130, and the third nut 141 is screwed in. Thereby, the lower floor column 1 is manufactured.

[0100] Next, fix the second bolt 120 to the lower-story column 1 (second bolt fixing step). Specifically, insert the second bolt 120 into the fourth through-hole 132a on the upper surface portion 132 of the right connecting fitting 130 (one connecting fitting 130) that constitutes the transmission member 40. From the opening (front opening or rear opening) of the right connecting fitting 130, attach a washer to the second bolt 120 and screw in the fourth nut 122. Also, attach a washer from above the right connecting fitting 130 and screw in the fourth nut 122. As a result, the second bolt 120 projects from the lower-story column 1.

[0101] Next, install the lower-story column 1 with the second bolt 120 projecting therefrom (lower-story column installation step). Next, install the upper-story floor 3 (upper-story floor installation step). At this time, insert the second bolt 120 projecting from the lower-story column 1 into the bolt insertion hole 3a of the upper-story floor 3. Next, screw in the lower second nut 121 onto the second bolt 120 projecting from the lower-story column 1 and attach a washer (lower nut attachment step). Also, fix the connecting fitting 130 to the upper-story column 2 with the first bolt 110 projecting therefrom (connecting fitting fixing step). Specifically, insert the first bolt 110 projecting from the upper-story column 2 into the fourth through-hole 132a on the upper surface portion 132 of the connecting fitting 130. From the opening (front opening or rear opening) of the connecting fitting 130, attach a washer to the first bolt 110 and screw in the first nut 111.

[0102] Next, dispose the upper-story column 2 with the connecting fitting 130 fixed thereon above the lower-story column 1 (upper-story column disposition step). At this time, insert the second bolt 120 into the third through-hole 131a on the lower surface portion 131 until the lower surface portion 131 of the connecting fitting 130 contacts the lower second nut 121 that is screwed onto the second bolt 120 projecting from the lower-story column 1. In this embodiment, the lower second nut 121 is screwed in the lower nut attachment step until the dimension between the connecting fitting 130 and the upper-story floor 3 at the end of the upper-story column disposition step becomes a dimension (e.g., 40 mm) shorter than the design dimension (e.g., 50 mm).

[0103] Next, a washer is attached to the second bolt 120 protruding from the lower floor column 1 through the opening (front side opening or rear side opening) of the connecting fitting 130, and the upper second nut 121 is screwed in (upper nut attachment step). Finally, the positions of the lower second nut 121 and the upper second nut 121 screwed onto the second bolt 120 protruding from the lower floor column 1 are adjusted so that the dimension between the connecting fitting 130 and the upper floor 3 becomes the designed dimension (for example, 50 mm) (adjustment step). As described above, the lower floor column 1 and the upper floor column 2 can be connected using the connection structure 200.

[0104] 《Effect》 According to the second embodiment, the following excellent effects are obtained. The connection structure 200 of the second embodiment is a connection structure that connects the lower floor column 1 and the upper floor column 2, and includes a connecting fitting 130 provided between the lower floor column 1 and the upper floor column 2, a second bolt 120 protruding from the lower floor column 1 toward the upper floor column 2, and a pair of second nuts 121 screwed onto the second bolt 120. The connecting fitting 130 includes a lower surface portion 131 through which the second bolt 120 passes and an upper surface portion 132 fixed to the upper floor column 2. The lower surface portion 131 is sandwiched from above and below by a pair of second nuts 121 screwed onto the second bolt 120.

[0105] That is, in the connection structure 200, among the pair of second nuts 121, the upper second nut 121 can resist upward forces, and the lower second nut 121 can resist downward forces. Therefore, the lower second nut 121 can resist downward forces (support the load from the upper floor column 2), so it is possible to avoid indentation into other building structure materials (upper floor 3 and lower floor column 1), making it suitable for mid-rise and high-rise buildings.

[0106] In addition, in the connection structure 200 of the second embodiment, the connecting hardware 130 can be configured to include a lower surface portion 131, an upper surface portion 132, and a side surface portion 133 that connects the lower surface portion 131 and the upper surface portion 132, and the side surface portion 133 can be made to have higher extensibility than the lower surface portion 131 and the upper surface portion 132. By configuring in this way, the energy absorption performance of the side surface portion 133 becomes higher than the energy absorption performance of the lower surface portion 131 and the upper surface portion 132. Therefore, it is possible to sufficiently resist horizontal loads during earthquakes, typhoons, etc., and thus it is suitable for mid- to high-rise buildings.

[0107] In addition, in the connection structure 200 of the second embodiment, the upper-story column 2 can be configured to include column timbers 11, 12, 13 and wooden fittings 21, 22, 23 that cover the upper and lower ends of the column timbers 11, 12, 13, and the lower-story column 1 can be configured to include column timbers 11, 12, 13 and wooden fittings 21, 22, 23 that cover the upper and lower ends of the column timbers 11, 12, 13. By configuring in this way, splitting of the column timbers 11, 12, 13 can be prevented. In addition, by configuring in this way, wooden columns can be used as the lower-story column 1 and the upper-story column 2, so it becomes possible to contribute to the realization of a decarbonized society through the promotion of carbon neutrality and the achievement of the SDGs goals. In recent years, the realization of a decarbonized society through the promotion of carbon neutrality, which substantially reduces carbon dioxide emissions, and the achievement of the SDGs goals have been demanded. Also in the construction industry, efforts are being made to make buildings wooden with low carbon dioxide emissions. Since the connection structure 100 in the second embodiment is a structure for connecting wooden columns, it can contribute to the realization of a decarbonized society through the promotion of carbon neutrality and can also contribute to the achievement of SDGs goal 7 "Ensure access to affordable, reliable, sustainable and modern energy for all" and goal 13 "Take urgent action to combat climate change and its impacts", etc.

[0108] Further, the connection structure 200 of the second embodiment can include a transmission member 40 that constitutes the upper end portion of the lower-story column 1. The lower-story column 1 can be configured to include a plurality of column timbers 11, 12, and 13, and the transmission member 40 can include a first metal fitting (connection metal fitting 130) fixed to each of the plurality of column timbers 11, 12, and 13, and a second metal fitting (plate-shaped metal fitting 41) that connects the first metal fittings. The second bolt 120 can be configured to protrude from any one of the plurality of first metal fittings toward the upper-story column 2. By configuring it in this way, the downward force (load from the upper-story column 2) can be dispersed to the plurality of column timbers 11, 12, and 13 that constitute the lower-story column 1 by the transmission member 40. That is, it is possible to avoid having the load from the upper-story column 2 applied only to one of the plurality of column timbers 11, 12, and 13 that constitute the lower-story column 1 (for example, the column timber located directly below the upper-story column 2), so it is possible to avoid the lower-story column 1 from sinking, making it suitable for mid-rise buildings. Also, by configuring it in this way, the lower-story column 1 is thicker than the upper-story column 2, so it is suitable for mid-rise buildings.

[0109] Further, in the connection structure 200 of the second embodiment, the connection metal fitting 130 can be diverted for use as the first metal fitting. By configuring it in this way, it becomes possible to produce the transmission member 40 simply by preparing a plurality of connection metal fittings 130 and connecting them with the second metal fitting (plate-shaped metal fitting 41). Therefore, since it is not necessary to prepare a metal fitting different from the connection metal fitting 130 as the first metal fitting of the transmission member 40, the manufacturing of the transmission member 40 becomes easy. Note that the first metal fitting of the transmission member 40 may be a metal fitting different from the connection metal fitting 130 (for example, a metal fitting having a shape different from that of the connection metal fitting 130).

[0110] Further, in the connection structure 200 of the second embodiment, the second metal fitting (plate-shaped metal fitting 41) can be made to have higher stretchability than the lower surface portion 131 and the upper surface portion 132 of the connection metal fitting 130. By configuring in this way, the energy absorption performance of the second metal fittings becomes higher than the energy absorption performance of the lower surface portion 131 and the upper surface portion 132. Therefore, it is possible to sufficiently resist horizontal loads such as during earthquakes and typhoons, and thus it is suitable for mid-rise and high-rise buildings.

[0111] <Third Embodiment> Next, a third embodiment of the present invention will be described. For convenience of explanation, elements common to the above-described first embodiment (including modifications) are denoted by common reference numerals, and the description thereof will be omitted or simplified. In the third embodiment, the lower-story structure including the lower-story column 1 is different from that of the first embodiment. Specifically, the lower-story structure (the lower-story column 1, the upper-story floor 3, and the lower-story ceiling beam not shown, etc.) including the lower-story column 1 in the first embodiment is made of wood. On the other hand, the lower-story structure (the lower-story column 1, the upper-story floor 3, the lower-story ceiling beam 4, the lower-story beam 5, etc.) including the lower-story column 1 in the third embodiment is made of reinforced concrete.

[0112] [Connection Structure] FIG. 14 is a longitudinal sectional view showing an example of the connection structure 300 in the third embodiment. The connection structure 300 is a structure for connecting the lower-story column 1 (the lower-story structure including the lower-story column 1) and the upper-story column 2 in a building, and is provided in a multi-story building. The upper-story column 2 includes column timber 12, a metal fitting 22 covering the lower end portion of the column timber 12, and a metal fitting 22 covering the upper end portion of the column timber 12. That is, the upper-story column 2 in the third embodiment is the same as the upper-story column 2 in the second modification (see FIG. 8). Note that the column timber constituting the upper-story column 2 in the third embodiment may be any of column timber 11, column timber 12, and column timber 13.

[0113] The lower-story structure including the lower-story column 1 is made of reinforced concrete, and includes the lower-story column 1, the upper-story floor 3, the lower-story ceiling beam 4, and the lower-story beam 5 located above the floor slab 34 of the upper-story floor 3 (on the side of the upper-story column 2). The upper end surface of the lower floor beam 5 is formed by the leveling material 14. A wooden base 15 is installed on the leveling material 14. A groove portion 15a penetrating in the left - right direction is formed in the base 15.

[0114] A second bolt 120 is embedded in the lower floor beam 5. The lower end portion of the second bolt 120 reaches inside the lower floor ceiling beam 4 and penetrates through the first fixing plate 123 located inside the lower floor ceiling beam 4. Also, a pair of fifth nuts 124 for fixing the first fixing plate 123 to the second bolt 120 are screwed onto the lower end portion of the second bolt 120. Therefore, the first fixing plate 123 is sandwiched from above and below by the pair of fifth nuts 124. In this embodiment, the embedding depth of the second bolt 120 (the distance from the upper surface of the first fixing plate 123 to the upper surface of the leveling material 14) is set to 500 mm, but it is not limited to this. Also, in this embodiment, the protruding dimension of the second bolt 120 (the length dimension of the portion protruding from the leveling material 14) is set to 206 mm, but it is not limited to this.

[0115] The protruding portion of the second bolt 120 (the portion protruding from the leveling material 14) penetrates through the second fixing plate 125 located in the groove portion 15a of the base 15. Also, a sixth nut 126 is screwed onto the protruding portion of the second bolt 120 from above the second fixing plate 125. Therefore, the second fixing plate 125 is fixed to the lower floor structure including the lower floor column 1 (specifically, the lower floor beam 5) by the sixth nut 126. The protruding portion of the second bolt 120 penetrates through the base 15. Therefore, the upper end portion (the tip of the protruding portion) of the second bolt 120 is located above the base 15 (on the upper floor column 2 side).

[0116] As shown in FIG. 14, similar to the connection structure 100 in the first embodiment and the connection structure 200 in the second embodiment, the connection structure 300 includes a second bolt 120 protruding from the lower-story structure including the lower-story column 1 toward the upper-story column 2, a pair of second nuts 121 screwed onto the upper end of the second bolt 120, a first bolt 110 protruding from the upper-story column 2 toward the lower-story structure including the lower-story column 1, a first nut 111 screwed onto the first bolt 110, and a connecting fitting 130 provided between the lower-story structure including the lower-story column 1 and the upper-story column 2. Furthermore, different from the connection structure 100 in the first embodiment and the connection structure 200 in the second embodiment, the connection structure 300 includes a first fixing plate 123 through which the lower end of the second bolt 120 penetrates, a pair of fifth nuts 124 screwed onto the lower end of the second bolt 120, a second fixing plate 125 through which the protruding portion of the second bolt 120 penetrates, and a sixth nut 126 screwed onto the protruding portion of the second bolt 120.

[0117] The lower end of the second bolt 120 is fixed to the lower-story structure including the lower-story column 1 by the first fixing plate 123. Also, the protruding portion of the second bolt 120 is fixed to the lower-story structure including the lower-story column 1 by the sixth nut 126. And in this embodiment, a second fixing plate 125 is interposed between the sixth nut 126 and the lower-story structure including the lower-story column 1.

[0118] Also, the connecting fitting 130 is fixed to the upper-story column 2 by a first bolt 110 protruding from the upper-story column 2 and a first nut 111 screwed onto the first bolt 110. Specifically, the tip (lower end) of the first bolt 110 protruding from the upper-story column 2 penetrates through a fourth through-hole 132a provided in the upper surface portion 132 of the connecting fitting 130, and a first nut 111 located inside the connecting fitting 130 (between the lower surface portion 131 and the upper surface portion 132) is screwed onto the tip via a washer (not shown). Therefore, the upper surface portion 132 of the connecting fitting 130 is sandwiched from above and below by the upper-story column 2 (specifically, the bottom surface portion 21a of the end fitting 21 covering the lower end of the column timber 11) and the first nut 111.

[0119] Further, the connecting hardware 130 is fixed to the lower floor structure including the lower floor column 1 by a second bolt 120 protruding from the lower floor beam 5 and a second nut 121 screwed onto the second bolt 120. Specifically, the protruding portion of the second bolt 120 protruding from the lower floor beam 5 penetrates the base 15 on the lower floor beam 5. Therefore, the upper end portion (the tip of the protruding portion) of the second bolt 120 protruding from the lower floor beam 5 is located above the base 15 (on the side of the upper floor column 2). And, the upper end portion of the second bolt 120 protruding from the lower floor beam 5 penetrates the third through hole 131a provided in the lower surface portion 131 of the connecting hardware 130. A second nut 121 located between the upper floor slab 3 and the connecting hardware 130 is screwed onto the upper end portion via a washer (not shown), and a second nut 121 located inside the connecting hardware 130 (between the lower surface portion 131 and the upper surface portion 132) is screwed onto the upper end portion via a washer (not shown). Therefore, the lower surface portion 131 of the connecting hardware 130 is sandwiched from above and below by the second nut 121 located between the lower surface portion 131 and the upper floor slab 3 and the second nut 121 located between the lower surface portion 131 and the upper surface portion 132.

[0120] In the connection structure 300, among the pair of second nuts 121, the upper second nut 121 (the second nut 121 located between the lower surface portion 131 and the upper surface portion 132) can resist an upward force (a force in the direction of pulling out the connecting hardware 130), and the lower second nut 121 (the second nut 121 located between the lower surface portion 131 and the upper floor slab 3) can resist a downward force (a force in the direction of pushing the connecting hardware 130). For example, if only the upper second nut 121 is provided without providing the lower second nut 121 and the connecting hardware 130 is brought into contact with the base 15, a downward force is transmitted through the connecting hardware 130, and there is a risk of indentation occurring in the base 15 and the lower floor beam 5. On the other hand, as in the present embodiment, by providing the lower second nut 121 at a position away from the base 15 and supporting the connecting hardware 130 from below with the lower second nut 121 to resist the downward force, it is possible to prevent the bending of the lower floor beam 5 from becoming small.

[0121] Furthermore, in the connection structure 300, the first fixing plate 123 can resist an upward force (the force in the direction of pulling out the second bolt 120), and the second fixing plate 125 can disperse a downward force (the force in the direction of pushing the second bolt 120). For example, if only the first fixing plate 123 is provided without providing the second fixing plate 125 and the sixth nut 126 is in contact with the lower floor beam 5 (or the sixth nut 126 is in contact with the lower floor beam 5 via a washer), a downward force is transmitted through the sixth nut 126, and there is a risk of the lower floor beam 5 being sunken. On the contrary, as in the present embodiment, by providing the second fixing plate 125 between the sixth nut 126 and the lower floor beam 5 and dispersing the downward force (the force from the sixth nut 126 to the lower floor beam 5) by the second fixing plate 125, it is possible to reduce the deflection of the lower floor beam 5.

[0122] [Connection method] Next, a method for connecting the lower structure including the lower column 1 and the upper column 2 using the connection structure 300 will be described. First, install the lower structure including the lower column 1 (the lower column 1, the upper floor 3, the lower ceiling beam 4, and the lower floor beam 5) (reinforced concrete structure installation step). At that time, after disposing the second bolt 120 with the first fixing plate 123 and a pair of fifth nuts 124 sandwiching the first fixing plate 123 from above and below at a predetermined position, pour concrete to embed the second bolt 120 in the lower structure including the lower column 1. Next, after attaching the second fixing plate 125 to the second bolt 120 protruding from the lower structure including the lower column 1 (specifically, the lower floor beam 5), screw in the sixth nut 126 to fix the second fixing plate 125 to the second bolt 120 (second fixing plate fixing step).

[0123] Next, screw in the lower second nut 121 to the second bolt 120 protruding from the lower floor beam 5 and attach a washer (lower nut attachment step). Also, a connection fitting 130 is fixed to the upper floor column 2 provided with the first bolt 110 (connection fitting fixing step). Specifically, the first bolt 110 provided on the upper floor column 2 is inserted into the fourth through hole 132a of the upper surface portion 132 of the connection fitting 130, and a washer is attached to the first bolt 110 from the opening (front opening or rear opening) of the connection fitting 130, and the first nut 111 is screwed in.

[0124] Next, the upper floor column 2 with the connection fitting 130 fixed is arranged above the lower floor beam 5 (upper floor column arrangement step). At this time, until the lower surface portion 131 of the connection fitting 130 contacts the lower second nut 121 screwed onto the second bolt 120 provided on the lower floor beam 5, the second bolt 120 is inserted into the third through hole 131a of the lower surface portion 131. In this embodiment, the lower second nut 121 is screwed in the lower nut attachment step until the dimension between the connection fitting 130 and the upper floor 3 at the end of the upper floor column arrangement step becomes a dimension shorter than the design dimension (for example, 50 mm) (for example, 40 mm).

[0125] Next, a washer is attached to the second bolt 120 provided on the lower floor beam 5 from the opening (front side opening or rear side opening) of the connection fitting 130, and the upper second nut 121 is screwed in (upper nut attachment step). Finally, the positions of the lower second nut 121 and the upper second nut 121 screwed onto the second bolt 120 provided on the lower floor beam 5 are adjusted so that the dimension between the connection fitting 130 and the upper floor 3 becomes the design dimension (for example, 50 mm) (adjustment step). As described above, the connecting structure 300 can be used to connect the reinforced concrete lower structure and the wooden upper floor column 2.

[0126] 《Effect》 According to the third embodiment, the following excellent effects are achieved. The connection structure 300 of the third embodiment is a connection structure that connects the lower-story column 1 (the lower-story structure including the lower-story column 1) and the upper-story column 2, and includes a connecting fitting 130 provided between the lower-story structure including the lower-story column 1 and the upper-story column 2, a second bolt 120 protruding from the lower-story structure including the lower-story column 1 toward the upper-story column 2, and a pair of second nuts 121 screwed onto the second bolt 120. The connecting fitting 130 includes a lower surface portion 131 through which the second bolt 120 passes and an upper surface portion 132 fixed to the upper-story column 2. The lower surface portion 131 is sandwiched from above and below by a pair of second nuts 121 screwed onto the second bolt 120.

[0127] That is, in the connection structure 300, among the pair of second nuts 121, the upper second nut 121 can resist upward forces, and the lower second nut 121 can resist downward forces. Therefore, the lower second nut 121 can resist downward forces (support the load from the upper-story column 2), so it is possible to avoid indentation into other building structure materials (such as the foundation 15 and the lower-story structure including the lower-story column 1), making it suitable for mid- to high-rise buildings.

[0128] Also, in the connection structure 300 of the third embodiment, the connecting fitting 130 can be configured to include a lower surface portion 131, an upper surface portion 132, and a side surface portion 133 that connects the lower surface portion 131 and the upper surface portion 132, and the side surface portion 133 can be made more extensible than the lower surface portion 131 and the upper surface portion 132. By configuring it in this way, the energy absorption performance of the side surface portion 133 becomes higher than the energy absorption performance of the lower surface portion 131 and the upper surface portion 132. Therefore, it is possible to sufficiently resist horizontal loads during earthquakes, typhoons, etc., making it suitable for mid- to high-rise buildings.

[0129] Also, in the connection structure 300 of the third embodiment, the upper floor column 2 can be configured to include column timbers 11, 12, 13 and wooden end fittings 21, 22, 23 that cover both the upper and lower ends of the column timbers 11, 12, 13. Further, the lower floor structure including the lower floor column 1 can be made of reinforced concrete, and the second bolt 120 protrudes from the lower floor structure including the lower floor column 1 toward the upper floor column 2. By configuring in this way, splitting of the column timbers 11, 12, 13 can be prevented. Also, by configuring in this way, a reinforced concrete structure can be used as the lower floor structure including the lower floor column 1, which is suitable for mid-rise buildings (especially the lower floors in mid-rise buildings). Also, by configuring in this way, a wooden column can be used as the upper floor column 2, which enables contribution to the realization of a carbon-neutral society through the promotion of carbon neutrality and the achievement of the SDGs goals. In recent years, there has been a demand for the realization of a carbon-neutral society by promoting carbon neutrality with substantially zero carbon dioxide emissions and the achievement of the SDGs goals. In the construction industry, efforts have been made to use wooden structures with low carbon dioxide emissions for buildings. Since the upper floor column among the upper and lower floor columns connected by the connection structure 300 in the third embodiment is made of wood, it can contribute to the realization of a carbon-neutral society through the promotion of carbon neutrality and the achievement of SDGs goals such as Goal 7 "Affordable and Clean Energy for All" and Goal 13 "Take Urgent Action to Combat Climate Change".

[0130] Also, the connection structure 300 of the third embodiment can be provided with a second fixing plate 125 through which the second bolt 120 passes. And the second fixing plate 125 can be fixed to the lower floor structure including the lower floor column 1 by a nut (sixth nut 126) that is screwed onto the second bolt 120 and is different from the pair of second nuts 121. By configuring in this way, it becomes possible to disperse the downward force (load from the upper floor column 2) transmitted to the lower floor structure including the lower floor column 1 by the second fixing plate 125. Therefore, it is possible to avoid the occurrence of subsidence in the lower floor structure including the lower floor column 1, and it is suitable for medium and high-rise buildings.

[0131] Note that the first embodiment (including the modification), the second embodiment, and the third embodiment can be combined. That is, in one building, it is possible to provide any one of the connection structures 100, 200, and 300, it is also possible to provide any two of them, or it is also possible to provide all of them. Specifically, for example, in one building, the column on the first floor and the column on the second floor are connected by the connection structure 300 (FIG. 14) in the third embodiment, the column on the second floor and the column on the third floor are connected by the connection structure 100 (FIG. 8) in the second modification of the first embodiment, the column on the third floor and the column on the fourth floor are connected by the connection structure 100 (FIG. 5) in the first modification of the first embodiment, and the column on the fourth floor and the column on the fifth floor may be connected by the connection structure 100 (FIG. 1) in the first embodiment.

Explanation of reference numerals

[0132] 1 Lower floor column 2 Upper floor column 11, 12, 13 Timber for column 21, 22, 23 Wood fittings 40 Transmission member 41 Plate-shaped fitting (second fitting) 100, 200, 300 Connection structure 120 Second bolt (bolt) 121 Second nut (nut) 125 Second fixing plate (fixing plate) 126 Sixth nut (another nut) 130 Connection fitting (first fitting) 131 Lower surface part 132 Upper surface part 133 Side surface part

Claims

1. A connecting structure for connecting a lower column and an upper column, comprising: A connecting fitting provided between the lower column and the upper column; A bolt protruding from the lower column toward the upper column; A pair of nuts screwed onto the bolt; and The connecting fitting includes a lower surface portion through which the bolt passes and an upper surface portion fixed to the upper column; The connecting structure is characterized in that the lower surface portion is sandwiched from above and below by the pair of nuts screwed onto the bolt.

2. In the connecting structure according to Claim 1, The connecting fitting includes a lower surface portion, an upper surface portion, and a side surface portion connecting the lower surface portion and the upper surface portion; The connecting structure is characterized in that the side surface portion has higher extensibility than the lower surface portion and the upper surface portion.

3. In the connecting structure according to Claim 1, The upper column includes a column timber and a wooden fitting covering both upper and lower ends of the column timber; The connecting structure is characterized in that the lower column includes a column timber and a wooden fitting covering both upper and lower ends of the column timber.

4. In the connecting structure according to Claim 3, The connecting structure includes a transmission member constituting the upper end portion of the lower column; The lower column includes a plurality of the column timbers; The transmission member includes a first fitting fixed to each of the plurality of column timbers and a second fitting connecting the first fittings; The connecting structure is characterized in that the bolt protrudes from any one of the plurality of first fittings toward the upper column.

5. In the connecting structure according to Claim 4, The connecting structure is characterized in that the connecting fitting can be diverted to the first fitting.

6. In the connecting structure according to Claim 4, The connecting structure is characterized in that the second fitting has higher extensibility than the lower surface portion and the upper surface portion.

7. In the connecting structure according to Claim 1, The upper column includes a column timber and a wooden fitting covering both upper and lower ends of the column timber; The lower structure including the lower column is made of reinforced concrete; The connecting structure is characterized in that the bolt protrudes from the lower structure toward the upper column.

8. In the connecting structure according to Claim 7, The connecting structure includes a fixing plate through which the bolt passes. The fixing plate is a nut that is screwed onto the bolt and is fixed to the lower structure by a nut different from the pair of nuts, and is characterized by a connection structure.

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