Tie-down system for wooden buildings

Abstract

In wooden buildings, when horizontal external forces such as earthquakes or wind pressure occur, this system can prevent the collapse of the wooden building due to uplift forces, and reliably prevents the tie rods from lifting up in response to the shrinkage of the wood due to drying or the weight of the building. [Solution] The wooden building 2 comprises a plurality of fixing hardware 11 fixed to beam members 22, 23, and 24, which are wooden structural members provided opposite each other at intervals, a pair of tie rods 12a and 12b whose rear ends are fixed to the upper and lower fixing hardware 11 of each floor (level), and a tensile force transmission hardware 13 connected to the ends of each of the tie rods 12a and 12b, which absorbs the contraction between the ends of the tie rods 12a and 12b and transmits the tensile force acting between the tie rods 12a and 12b.

Description

Technical Field

[0001] The present invention relates to a wood building tie-down system using tie rods used in wooden buildings.

Background Art

[0002] When an external force in the horizontal direction such as an earthquake or wind pressure occurs in a wooden building, it is necessary to prevent the collapse of the wooden building due to the pulling force, and at the same time, shrinkage of the wood occurs due to drying of the wood and settlement due to the weight of the building. Therefore, in relatively high-rise wooden buildings, a tie-down system for wooden buildings is adopted in which tie rod fittings that absorb the gap between the nut and washer are installed on the tie rods passing through each floor to cope with shrinkage due to drying of the wood and settlement due to the weight of the building (see, for example, Patent Documents 1 and 2).

[0003] For example, the prior art of Patent Document 1 is a structure in which a shear wall is provided between columns of a wooden building whose skeleton is formed by columns and beams. Even when an excessive horizontal force acts on the beam, the facing material is firmly fixed so as not to separate from the beam or the like, and at the same time, the shear wall is formed without requiring much labor and time. An attachment structure of a facing material attached away from the column between adjacent columns on which beams are installed at intervals on a foundation or a base, and a rod-shaped fixing member that connects the foundation and the beam near both sides in the axial direction of the beam of the CLT panel, which is the facing material, sandwiches and fixes the CLT panel with the foundation and the beam.

[0004] Furthermore, the prior art disclosed in Patent Document 2 aims to provide a packing that is highly versatile and easy to install, while preventing the lifting of a shear wall even when a large uplift force acts on the end of the shear wall during a typhoon or earthquake. The packing comprises an inner cylinder member through which the tie rod is inserted and which has a male threaded portion formed on its outer circumference, an outer cylinder member through which the inner cylinder member is inserted and which has a female threaded portion formed on its inner circumference into which the male threaded portion is screwed, and a biasing means that biases the inner cylinder member and the outer cylinder member with a rotational force that causes the other to rotate relative to one of the inner cylinder member and the other. The inner cylinder member is inserted in an unlocked state, and the biasing means biases the inner cylinder member with a rotational force that causes it to protrude from the outer cylinder member. The coil spring is arranged to surround the outer cylinder member, one end of the coil spring is connected to the inner cylinder member, and the other end of the coil spring is connected to the outer cylinder member. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-139251 [Patent Document 2] Japanese Patent Publication No. 2014-20423 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, the rod-shaped fixing member described in Patent Document 1 above consists of multiple tie rods, couplers, nuts, etc., and resists the pull-out force (tensile force) when a horizontal force is generated, but does not take into account the shrinkage of the wood. As a result, when the wood shrinks, a gap is created between the washer and the beam.

[0007] Furthermore, even if the mechanism disclosed in the prior art of Patent Document 2, which follows the shrinkage of wood, is attached to the prior art of Patent Document 1, the tie rods are not fixed to the beams of each floor (level), so the tie rods and couplers cannot move independently for each floor. Therefore, if the amount of shrinkage of structural members such as columns differs for each floor (level), when the tie rods are connected in a series, the entire rod-shaped fixing member cannot uniformly follow the shrinkage occurring on each floor, resulting in a gap between the washer and nut, and there remains a possibility that the rod-shaped fixing member will not be able to perform as expected.

[0008] Therefore, the present invention has been made in view of these problems, and aims to provide a tie-down system for wooden buildings that can prevent the collapse of wooden buildings due to uplift forces when horizontal external forces such as earthquakes and wind pressure occur in wooden buildings, and can reliably prevent the tie rods from lifting up in response to the shrinkage of wood due to drying of the wood or the weight of the building itself. [Means for solving the problem]

[0009] To solve the above problems, the tie-down system for wooden buildings according to the present invention is characterized by comprising: a plurality of fixing hardware fixed to wooden structural members that are spaced apart and facing each other in a wooden building; a pair of tie rods whose rear ends are fixed to the plurality of fixing hardware; and a tensile force transmitting hardware connected to the ends of each of the pair of tie rods, which absorbs the contraction between the ends of the pair of tie rods and transmits the tensile force between the pair of tie rods. Furthermore, the tie-down system for wooden buildings according to the present invention is also characterized in that the tensile force transmission hardware comprises a box-shaped frame having a tie rod fixing portion to which the tip of one of the pair of tie rods is fixed, and a tie rod passing portion having a tie rod through hole through which the tip of the other of the pair of tie rods passes, and a tensile force transmission member provided between the tip of the other tie rod that passes through the tie rod through hole of the box-shaped frame and the tie rod passing portion, which absorbs the contraction between the pair of tie rod tips and transmits the tensile force between the pair of tie rods. Furthermore, in the tie-down system for wooden buildings according to the present invention, the box-shaped frame has a tapered inner surface recess having an inner surface that narrows downwards, and a tie rod through hole is provided in the center of the recess. The tensile force transmission member has a tapered outer surface that contacts the inner surface of the tapered inner surface recess, and has a tie rod through hole in the center through which the tip of the other tie rod passes. The member is housed in the tapered inner surface recess of the box-shaped frame, and when a tensile force is applied to the box-shaped frame, the outer surface of the tensile force transmission member is pressed by the tapered inner surface of the tapered inner surface recess, causing the tie rod through hole to narrow, thereby elastically deforming and gripping the other tie rod, and transmitting the tensile force to the other tie rod. Furthermore, the tie-down system for wooden buildings according to the present invention is also characterized in that a compression coil spring is provided between the upper surface of the tensile force transmission member and the fastening nut that is screwed onto the male threaded portion of the other tie rod tip that passes through the tie rod through hole of the tensile force transmission member, thereby pressing the tensile force transmission member toward the tapered inner surface recess. Furthermore, the tie-down system for wooden buildings according to the present invention is characterized in that the tensile force transmission member comprises an inner coupler having a female threaded portion that screws into the male threaded portion at the tip of the other tie rod and a male threaded portion on its outer circumference, an outer coupler having a female threaded portion that screws into the male threaded portion of the inner coupler, a tightening ring having a tie rod through hole for the other tie rod to pass through and installed above the inner coupler and the outer coupler, and a coil spring whose upper end is fixed to the tightening ring and whose lower end is fixed to the outer coupler and is provided to cover the outer circumference of the outer coupler, and the tightening ring is provided with a bolt hole that penetrates from its outer circumference to the tie rod through hole, and a tightening ring fixing bolt is provided which is inserted into the bolt hole and screwed in, and whose tip protrudes from the tie rod through hole and abuts against the other tie rod to fix the tightening ring to the other tie rod. [Effects of the Invention]

[0010] The tie-down system for wooden buildings according to the present invention comprises a plurality of fastening hardware fixed to wooden structural members that are spaced apart and facing each other in a wooden building, a pair of tie rods whose rear ends are fixed to the plurality of fastening hardware, and a tensile force transmitting member connected to the tip of each of the tie rods, which transmits the tensile force acting on the tie rods and follows the reduction in the distance between the tips of the tie rods by contracting. Therefore, the tensile force transmission members installed on each floor (level) transmit the tensile force to the foundation, etc., when excessive tensile force is generated in a pair of tie rods due to horizontal external forces such as earthquakes or wind pressure, thereby preventing the collapse of wooden buildings. Furthermore, when the wood shrinks due to drying or the weight of the building, causing the distance between the ends of the tie rods to decrease, each floor (level) will contract independently to follow the contraction, thereby reliably preventing the tie rods from lifting up. [Brief explanation of the drawing]

[0011] [Figure 1](a) and (b) are diagrams showing examples of wooden buildings using the wooden building tie-down system of Embodiment 1 according to the present invention, respectively, with the columns of each floor shown in the state before shrinkage and the state after shrinkage. [Figure 2] (a) and (b) are enlarged plan and front views, respectively, of portion A in Figure 1(a), which includes the fastening hardware that constitutes the tie-down system for wooden buildings of Embodiment 1 according to the present invention. [Figure 3] (a) to (d) are plan view, front view, side view, and cross-sectional view along line CC of the fastening hardware constituting the wooden building tie-down system of Embodiment 1 according to the present invention, respectively. [Figure 4] (a) and (b) are front views showing the upper tie rod and lower tie rod, respectively, which constitute the wooden building tie-down system of Embodiment 1 according to the present invention. [Figure 5] (a) to (c) are plan view, front view, and side view of portion B in Figure 1(a), which includes the tensile force transmission hardware that constitutes the tie-down system for wooden buildings of Embodiment 1 according to the present invention. [Figure 6] (a) and (b) are figures showing the state before reduction of the distance between the tie rod tips in the tensile force transmission hardware constituting the wooden building tie-down system of Embodiment 1 according to the present invention, and a cross-sectional view showing the state after the distance between the tie rod tips has been reduced. [Figure 7] (a) to (e) are plan view, front view, and side view of Modified Example 1 of the fixing hardware constituting the wooden building tie-down system of Embodiment 1 according to the present invention, a plan view showing Modified Example 1 fixed to a beam, and a front view showing that state. [Figure 8] (a) to (d) are plan view, front view, and side view of Modified Example 2 of the fixing hardware constituting the wooden building tie-down system of Embodiment 1 according to the present invention, a plan view showing Modified Example 2 fixed to a beam, and a front view showing that state. [Figure 9] (a) to (d) are plan view, front view, and side view of Modified Example 3 of the fixing hardware constituting the wooden building tie-down system of Embodiment 1 according to the present invention, a plan view showing Modified Example 3 fixed to a beam, and a front view showing that state. [Figure 10] (a) to (d) are respectively a plan view, a front view, a side view of Modification Example 4 of the fixture constituting the tie-down system for wooden buildings according to Embodiment 1 of the present invention, a plan view showing the state where Modification Example 4 is fixed to a beam member, and a front view of that state. [Figure 11] It is a front view of a wooden building using a well-known washer and nut as Modification Example 5 of the fixture constituting the tie-down system for wooden buildings according to Embodiment 1. [Figure 12] (a) to (c) are respectively a front view, a side view, and a bottom view of the state where a tie rod is connected to the tensile force transmission member constituting the tie-down system for wooden buildings according to Embodiment 2 of the present invention. [Figure 13] It is an enlarged front view of the main part showing the main part of the tensile force transmission member (tie rod fastening member) constituting the tie-down system for wooden buildings according to Embodiment 2 of the present invention. [Figure 14] It is a view showing the installation procedure of the tensile force transmission member (tie rod fastening member) constituting the tie-down system for wooden buildings according to Embodiment 2 of the present invention, and is a view showing the state immediately before attaching the inner coupler to the lower tie rod. [Figure 15] It is a view showing the installation procedure of the tensile force transmission member (tie rod fastening member) constituting the tie-down system for wooden buildings according to Embodiment 2 of the present invention, and is a view showing the state immediately before attaching in a state where an outer coupler, a tightening ring, and a coil spring are connected to the lower tie rod to which the inner coupler is attached. [Figure 16] (a) and (b) are respectively views showing the installation procedure of the tensile force transmission member (tie rod fastening member) constituting the tie-down system for wooden buildings according to Embodiment 2 of the present invention. After attaching an inner coupler, an outer coupler, a tightening ring, etc. to the lower tie rod, the tightening ring is lowered to compress the coil spring, and it is a view showing the state where the nut is screwed onto the male screw portion of the tie rod, and then it is a view showing the state where the nut is lowered to the upper surface of the lowered tightening ring. [Figure 17](a), (b) These are diagrams showing the installation procedure of the tension transmission hardware (tie rod fastening hardware) that constitutes the tie-down system for wooden buildings according to Embodiment 2 of the present invention. In the state where the tightening ring is lowered to the compressed state of the coil spring, it shows the state where the nut is tightened and fixed to the lower tie rod, and it is a diagram showing the operation of the tension transmission hardware (tie rod fastening hardware) when the lower tie rod floats after the installation of the tension transmission hardware (tie rod fastening hardware). [Figure 18] (a), (b) These are diagrams showing the reset procedure of the tension transmission hardware (tie rod fastening hardware) that constitutes the tie-down system for wooden buildings according to Embodiment 2 of the present invention. It shows the state where the tightening ring is lowered again and the coil spring is twisted by rotating the tightening ring, and then it shows the state where the nut is lowered again to the upper surface of the tightening ring and tightened, and the tightening ring fixing bolt is tightened and fixed again.

Mode for Carrying Out the Invention

[0012] Embodiment 1. Hereinafter, the tie-down system 1 for wooden buildings according to Embodiment 1 of the present invention will be described. Note that the tie-down system 1 for wooden buildings in Embodiment 1 described below is merely an example of the present invention, and the present invention is not limited to the tie-down system 1 for wooden buildings in Embodiment 1 below, and can be appropriately changed within the scope of the creation of the technical idea of the present invention.

[0013] <Configuration of the Tie-Down System 1 for Wooden Buildings According to Embodiment 1 of the Present Invention> The wooden building tie-down system 1 of Embodiment 1 according to the present invention, as shown in Figure 1, transmits tensile force acting on the upper tie rod 12a and lower tie rod 12b, which are a pair of tie rods that connect opposing wooden structural members such as the foundation 21, floor beams 22 and 23 of the 2nd and 3rd floors, and ceiling beams 24 of the 3rd floor, to each floor individually, and also follows the contraction of the space between the ends of the tie rods 12a and 12b due to the shrinkage or sinking of the wooden beams 22-24 and columns 25-27 of each floor, respectively. The structure comprises a plurality of fixing hardware 11 fixed to the base 21 and a pair of upper tie rods 12a and lower tie rods 12b fixed to each other via the plurality of fixing hardware 11 between the opposing base 21 and beam members 22, 23, 24, respectively, and a tensile force transmission hardware 13 connected to the lower end of the upper tie rod 12a and the upper end of the lower tie rod 12b, respectively, which absorbs the reduction between the ends of the tie rods 12a and 12b in accordance with the reduction or sinking of beam members 22-24 and column members 25-27, and transmits tensile force between the tie rods 12a and 12b.

[0014] Furthermore, the lower tie rod 12b, which is connected to the lower part of the tensile force transmission hardware 13 on the first floor, is fixed via a washer 12c to a nut 12d embedded in the sill 21 or the foundation below it (not shown) by passing through the sill 21. However, it is also possible to embed fixing hardware 11 in the sill 21, similar to the beam members 22, 23, 24, etc., and fix the lower end of the lower tie rod 12b to the fixing hardware 11 fixed to the sill 21.

[0015] (Fixing hardware 11) The fixing hardware 11 is a cylindrical or cylindrical rod-shaped metal fitting that is inserted into a cylindrical through-hole provided to penetrate the beam members 22, 23, and 24 in the vertical direction, as shown in Figures 1 and 2, and is fixed with a fixing pin 14a. As shown in Figures 3(a) to (d), the upper and lower ends of the fixing hardware are provided with female threaded portions 11a and 11b into which the male threaded portions 12a1 and 12b1 of the upper tie rod 12a and lower tie rod 12b are screwed, respectively. Between the female threaded portions 11a and 11b, there are three pin holes 11c into which a rod-shaped, well-known fixing pin 14a that penetrates the beam members 22, 23, and 24 is inserted.

[0016] (Upper tie rod 12a and lower tie rod 12b) As shown in Figure 4(a), the upper tie rod 12a is a longer tie rod than the lower tie rod 12b and is made of a rod-shaped member such as iron. Its upper and lower ends are provided with male threaded portions 12a1 that screw into the lower female threaded portion 11b of the fixing hardware 11 and the female threaded portion 13a11 of the tensile force transmission hardware 13, which will be described later.

[0017] As shown in Figure 4(b), the lower tie rod 12b is shorter than the upper tie rod 12a and, like the upper tie rod 12a, is made of a rod-shaped member such as iron. Its upper and lower ends are provided with male threaded portions 12b1 that screw into the fastening nut 13d or the upper female threaded portion 11a of the fixing hardware 11.

[0018] (Tensile force transmission hardware 13) As shown in Figures 5(a) to (c), the tensile force transmission hardware 13 includes a box-shaped steel frame 13a, which is box-shaped and has no front or rear sides; a frustoconical washer 13b, which is a tensile force transmission member, and a compression coil spring 13c, which are provided inside the box-shaped steel frame 13a.

[0019] As shown in Figures 5(a) to (c), the box-shaped frame 13a has an upper part 13a1 as a tie rod fixing part, which is provided with a female threaded part 13a11 into which the male threaded part 12a1 at the lower end of the upper tie rod 12a is screwed; a lower part 13a2 as a tie rod passing part, which is provided with a frustoconical recess 13a21 as a tapered inner surface recess for housing a frustoconical washer 13b and a tie rod through hole 13a22 (see Figure 6) through which the lower tie rod 12b passes; and the upper part 13a1 and the lower part 13a2 are formed into a box shape by a pair of lateral parts 13a3, 13a3, which are open in the front-rear direction and form a working space 13e for tightening fastening nuts 13d, 13d that are screwed onto the male threaded part 12a1 of the upper tie rod 12a and the male threaded part 12b1 of the lower tie rod 12b, respectively.

[0020] As shown in Figure 6, the frustoconical washer 13b has an inner diameter approximately the same as the outer diameter of the lower tie rod 12b, a tie rod through hole 13b1 through which the lower tie rod 12b passes, and a frustoconical outer surface 13b2 formed in a tapered shape that narrows downwards. Like the box frame 13a, it is made of steel. Therefore, the frustoconical recess 13a21 that accommodates the frustoconical washer 13b is also formed in a frustoconical shape that narrows downwards, and its lower part is continuous with the tie rod through hole 13a22. In particular, the frustoconical washer 13b and the frustoconical recess 13a21 are provided in such a state that the frustoconical outer surface 13b2 of the frustoconical washer 13b and the inner surface of the frustoconical recess 13a21 are in close contact and fitted together.

[0021] The reason why the shape of the frustoconical washer 13b's frustoconical outer surface 13b2 and the frustoconical recess 13a21's inner surface are tapered cones that narrow towards the bottom is that when an uplift force is applied to a load-bearing wall or the like on which this tensile force transmission hardware 13 is installed, the box-shaped frame 13a of the tensile force transmission hardware 13 tries to move upward, and the frustoconical washer 13b (lower tie rod 12b) resists the upward movement of the box-shaped frame 13a and is pushed downward relatively. As a result, an external force acts on the frustoconical washer 13b from the outside toward the center on the frustoconical outer surface 13b2 that is in contact with the frustoconical recess 13a21, narrowing the inner diameter of the tie rod through hole 13a22 of the frustoconical washer 13b. This increases the chuck force when gripping the lower tie rod 12b, and ensures that the pull-out force acting on the shear wall, etc., is reliably transmitted as tensile force to the lower tie rod 12b.

[0022] Therefore, the frustoconical washer 13b may be made of the same steel material as the box-shaped frame 13a, which is a steel frame. However, since it is necessary for the frustoconical washer 13b to elastically deform when pressed against the frustoconical recess 13a21 of the box-shaped frame 13a to chuck the lower tie rod 12b, a softer steel material than that of the box-shaped frame 13a is preferable. However, it is not limited to steel; for example, elastic rubber may also be used. Furthermore, the shape of the outer surface of the frustoconical washer 13b and the inner surface of the frustoconical recess 13a21 are not limited to a frustoconical shape, but can be any trapezoidal shape that tapers downwards. In addition, the inner surface of the tie rod through hole 13a22 of the frustoconical washer 13b may be formed not only as a cylindrical shape but also as an uneven shape, etc. By making the inner surface of the tie rod through hole 13a22 uneven, the frictional force is improved, so the lower tie rod 12b can be held more firmly.

[0023] The compression coil spring 13c is a well-known compression coil spring. The presence of the compression coil spring 13c ensures that the frustoconical washer 13a is constantly pressed against the lower tie rod 12b, thereby more reliably transmitting tensile force. However, since the frustoconical washer 13b falls freely due to its own weight and is pressed against the lower tie rod 12b along the frustoconical recess 13a21, the compression coil spring 13c may be omitted.

[0024] <Operation of the wooden building tie-down system 1 of Embodiment 1 according to the present invention> Next, the operation of the tie-down system 1 for wooden buildings, which is installed in a wooden building 2, according to Embodiment 1 of the present invention will be described.

[0025] (Transmission of tensile force) In the wooden building tie-down system 1 of Embodiment 1 of the present invention, as shown in Figure 1, the upper tie rod 12a and lower tie rod 12b connected to the tensile force transmission hardware 13 on each floor from the 1st to the 3rd floor are fixed to wooden structural members such as beams 22, 23, and 24 via fixing hardware 11. On each floor, the lower tie rod 12b is fastened with a fastening nut 13 via a frustoconical washer 13b, with the frustoconical outer surface 13b2 in contact with the inner surface of the frustoconical recess 13a21 of the box-shaped frame 13a.

[0026] Therefore, if an uplift force acts on load-bearing walls constructed of wooden structural members such as beams 22, 23, and 24 on a specific floor due to an earthquake or the like, and the box-shaped frame 13a of the tensile force transmission hardware 13 attempts to move upward, the frustoconical washer 13b and the lower tie rod 12b resist the upward movement of the box-shaped frame 13a, and are pushed downward relatively.

[0027] As a result, an external force acts on the frustoconical washer 13b, which is housed in a state where its frustoconical outer surface 13b2 is in contact with the inner surface 13a21 of the frustoconical recess 13a21. This causes the washer to elastically deform, narrowing the inner diameter of the tie rod through hole 13b1. Consequently, the chuck force of the frustoconical washer 13b gripping the lower tie rod 12b increases, allowing the pull-out force acting on the shear wall, etc., to be reliably transmitted as tensile force to the lower tie rod 12b.

[0028] In particular, in the wooden building tie-down system 1 of Embodiment 1, the tensile force transmission hardware 13 on each floor is provided with a compression coil spring 13c that constantly presses the frustoconical washer 13b toward the frustoconical recess 13a21 between the upper surface of the frustoconical washer 13b and the fastening nut 13d that screws onto the male threaded portion 12b1 at the tip of the lower tie rod 12b that penetrates the frustoconical washer 13b. As a result, the frustoconical washer 13b can more reliably transmit tensile force to the lower tie rod 12b by the amount of the compression force of the compression coil spring 13c.

[0029] (Absorption of the reduction in the distance between the tips of tie rods 12a and 12b) Furthermore, for example, in a three-story wooden building 2 where the wooden building tie-down system 1 of Embodiment 1 according to the present invention, as shown in Figure 1(a), is installed, if the columns 25, 26, 27 or beams 22, 23, 24, etc., shrink or settle, the entire wooden building 2 will shrink as shown in Figure 1(b).

[0030] As a result, although each tensile force transmission fitting 13 installed on each floor from the 1st to the 3rd floor is connected to the upper tie rod 12a and the lower tie rod 12b at the upper part 13a1 and lower part 13a2 respectively, as shown in Figure 6(a), at the upper part 13a1, the male threaded part 12a1 of the upper tie rod 12a is screwed into the female threaded part 13a11 and fastened with a fastening nut 13d, and is fixed to the upper tie rod 12a, the upper part 13a1 cannot absorb the reduction in the gap between the lower end of the upper tie rod 12a and the upper end of the lower tie rod 12b due to the shrinkage or sinking of beam members 22-24 or columns 25-27, etc. Furthermore, since the lower end of the upper tie rod 12a is fastened by a fastening nut 13d as shown in Figures 5 and 6, the upper part 13a1 of the tensile force transmission fitting 13 may be made into a tie rod through hole without forming a female threaded portion 13a11, so that the tensile force transmission fitting 13 falls out under its own weight when contraction or sinking occurs.

[0031] On the other hand, in the lower part 13a2 of each tension transmission fitting 13, the lower tie rod 12b penetrates through the tie rod through-hole 13a22 and is exposed in the working space part 13e of each tension transmission fitting 13. Since the male screw part 12b1 at the tip (upper end) of the lower tie rod 12b is fastened by the nut 13d via the frustum-shaped washer 13b and the compression coil spring 13c, when the column members 25, 26, 27, the beam members 22, 23, 24, etc. contract, as shown in the state before reduction in Fig. 6(a) to the state after reduction in Fig. 6(b), the tip (upper end) of the lower tie rod 12b extends further into the working space part 13e, and the interval between the lower end of the upper tie rod 12a and the upper end of the lower tie rod 12b contracts from the interval G1 before contraction to the interval G2 (<G1) after contraction.

[0032] Then, in the tension transmission fittings 13 provided on each of the 1st to 3rd floors, the compression coil spring 13c extends as shown in Fig. 6(b), and independently on each of the 1st to 3rd floors, it follows the reduction in the distance between the tips of the tie rods 12a and 12b due to shrinkage or settlement of the wood such as the beam members 22 to 24 and the column members 25 to 27, and absorbs the amount of shrinkage.

[0033] In addition, when the frustum-shaped washer 13b and the compression coil spring 13c of the tension transmission fitting 13 extend due to aging changes such as one year or two years, the fastening nut 13d that is screwed onto the male screw part 12b1 at the upper end of the lower tie rod 12b and presses the frustum-shaped washer 13b and the compression coil spring 13c is tightened more, and the frustum-shaped washer 13b and the compression coil spring 13c are contracted (compressed) again, and again, independently on each floor, it is reset to a state where it can follow the reduction in the distance between the tips of the tie rods 12a and 12b due to shrinkage or settlement of the wood and absorb the amount of shrinkage.

[0034] <Effects of the tie-down system 1 for wooden buildings according to Embodiment 1 of the present invention> As described above, in the wooden building tie-down system 1 of Embodiment 1, the upper tie rod 12a and lower tie rod 12b of the tensile force transmission hardware 13 on each floor are fixed to wooden structural members such as beams 22, 23, and 24 via fixing hardware 11. In the tensile force transmission hardware 13 on each floor, the lower tie rod 12b is fastened with a fastening nut 13 via a frustoconical washer 13b, which is housed in a frustoconical recess 13a21 of a box-shaped frame 13a with its frustoconical outer surface 13b2 in contact with the inner surface 13a21.

[0035] Therefore, an external force acts on the frustoconical outer surface 13b2 of the frustoconical washer 13b from the outside toward the center due to the frustoconical inner surface of the frustoconical recess 13a21, narrowing the inner diameter of the tie rod through hole 13b1 of the frustoconical washer 13b, and the frustoconical washer 13b can grip the lower tie rod 12b and reliably transmit the pull-out force acting on the shear wall, etc., to the lower tie rod 12b as a tensile force.

[0036] Furthermore, even if excessive tensile force is generated in the upper tie rod 12a and lower tie rod 12b connected to the tensile force transmission fittings 13 installed on each floor from the 1st to the 3rd floor when an external force acting horizontally, such as an earthquake or wind pressure, the lower tie rod 12b is inserted into the frustoconical washer 13b and installed within the frustoconical recess 13a21 of the box-shaped frame 13a of the tensile force transmission fittings 13 on each floor from the 1st to the 3rd floor. Therefore, when tensile force is generated, the force is transferred from the frustoconical washer 13b to the lower tie rod 12b, and further, to the foundation, etc. By transmitting force to the tensile force transmission hardware 13, when the columns 25, 26, 27 and beams 22, 23, 24 contract due to the drying of the wood or the weight of the building, and the distance between the tips of the upper tie rods 12a and lower tie rods 12b connected to each tensile force transmission hardware 13 decreases, the tensile force transmission hardware 13 independently performs a follow function for each floor (level) and follows the decrease in the distance between the tips of the upper tie rods 12a and lower tie rods 12b, thereby reliably preventing the lower tie rods 12b from floating up on each floor.

[0037] In particular, in the wooden building tie-down system 1 of Embodiment 1, a compression coil spring 13c is provided between the upper surface of the frustoconical washer 13b and the fastening nut 13d that screws onto the male threaded portion 12b1 at the tip of the lower tie rod 12b. This compression coil spring 13c constantly presses the frustoconical washer 13b toward the frustoconical recess 13a21. As a result, the frustoconical washer 13b strongly grips the lower tie rod 12b by the amount of the compression force of the compression coil spring 13c, enabling the tensile force acting between the upper tie rod 12a and the lower tie rod 12b to be transmitted more reliably with a simple configuration. Furthermore, as the gap between the tips of the upper tie rod 12a and the lower tie rod 12b shrinks, the lifting of the lower tie rod 12b on each floor can be reliably prevented.

[0038] In the description of Embodiment 1 above, the tensile force transmission hardware 13 was described as having a frustoconical washer 13b and a compression coil spring 13c inside a box-shaped frame 13a. However, the present invention is not limited to this, and of course, a washer may be provided between the frustoconical washer 13b and the compression coil spring 13c, or even just one of the frustoconical washer 13b or the compression coil spring 13c may be provided.

[0039] Furthermore, since other configurations are possible for the fixing hardware 11 and the tensile force transmission hardware 13, we will also explain modified examples 1 to 5, which are alternative configurations of the fixing hardware 11 and the tensile force transmission hardware 13.

[0040] <Example 1 of fixing hardware> Figures 7(a) to 7(e) show a plan view, front view, and side view of a fixing hardware 15 which is a modified example 1 of the fixing hardware constituting the wooden building tie-down system 1 of Embodiment 1 according to the present invention, a plan view showing the modified example 1 fixed to a beam member 22, and a front view of that state, respectively.

[0041] As shown in Figures 7(a) to 7(c), the fixing hardware 15 of the modified example consists of a fixing hardware body 15a, which is a rectangular steel plate with nine pin holes 15a1, and nut bodies 15b, 15b, each having a female screw portion 15b1, which are joined to the upper and lower end faces of the fixing hardware body 15a by welding or the like.

[0042] Then, a slit is formed in the beam member 22 in advance into which the fixing hardware body 15a of the modified example 1 can be inserted, and pin insertion holes are formed through the slit at the positions of the nine pin holes 15a1 of the fixing hardware body 15a. As shown in Figures 7(d) and (e), the fixing hardware 15 of the modified example 1 is inserted into the slit of the beam member 22, causing the nut bodies 15b, 15b to protrude from the top and bottom of the beam member 22, respectively.

[0043] Next, the fixing pins 14a are passed through the nine pin insertion holes in the beam member 22 and the nine pin holes 15a1 in the fixing hardware body 15a to fix the fixing hardware 15 of Modification 1 to the beam member 22. The male threaded portion 12b1 at the lower end of the lower tie rod 12b is screwed into the female threaded portion 15b1 of the upper nut body 15b, while the male threaded portion 12a1 at the upper end of the upper tie rod 12a is screwed into the female threaded portion 15b1 of the lower nut body 15b. In this way, the lower tie rod 12b of the second floor and the upper tie rod 12a of the first floor can be fixed to the beam member 22, etc., in the same way as the fixing hardware 11 described above.

[0044] <Modified example of fixing hardware 2> Figures 8(a) to 8(e) show a plan view, front view, and side view of a fixing hardware 16, which is a modified example 2 of the fixing hardware constituting the wooden building tie-down system 1 of Embodiment 1 according to the present invention, a plan view showing the fixing hardware 16 fixed to the beam member 22, and a front view of that state, respectively.

[0045] The fixing hardware 16 of the modified example 2 is constructed by dividing the fixing hardware 15 of the modified example 1 described above into two parts, upper and lower. As shown in Figures 8(a) to (c), it consists of a fixing hardware body 16a made of a rectangular steel plate with three pin holes 16a1, and a nut body 16b having a female screw portion 16b1 joined to the upper side of the fixing hardware body 16a by welding or the like. As shown in Figure 8(e), two of these are used as a set.

[0046] Furthermore, the beam member 22, etc., has slits formed in advance on its upper and lower sides into which the fixing hardware body 16a of modified example 2 can be inserted, and pin insertion holes are formed through the slits at the positions of three pin holes 16a1 in each of the two fixing hardware bodies 16a. As shown in Figures 8(d) and (e), the fixing hardware 16 of modified example 2 is inserted into the slits from the upper and lower sides of the beam member 22, causing the nut bodies 16b, 16b to protrude from the upper and lower sides of the beam member 22, respectively.

[0047] Then, by passing the fixing pins 14a through the six pin insertion holes in the beam member 22 and the pin holes 16a1 in the fixing hardware body 16a, respectively, and fixing the fixing hardware 16 of Modified Example 2 to the top and bottom of the beam member 22, and screwing the male threaded portion 12b1 of the lower end of the lower tie rod 12b into the female threaded portion 16b1 of the nut body 16b of the upper fixing hardware 16 that protrudes from the upper side surface of the beam member 22, and screwing the male threaded portion 12a1 of the upper end of the upper tie rod 12a into the female threaded portion 16b1 of the nut body 16b of the lower fixing hardware 16 that protrudes from the lower side surface of the beam member 22, the lower tie rod 12b of the second floor and the upper tie rod 12a of the first floor can be fixed to the beam member 22 that constitutes the floor of the second floor, similar to the fixing hardware 11 and the fixing hardware 15 of Modified Example 1 described above.

[0048] Furthermore, in the case of the fixing hardware 16 of the modified example 2 shown in Figure 8, unlike the fixing hardware 11 of Embodiment 1 and the fixing hardware 15 of Modified Example 1, the upper tie rod 12a of the lower floor and the lower tie rod 12b of the upper floor are not connected via the fixing hardware 16.

[0049] <Modification example 3 of the fixing hardware> Figures 9(a) to 9(e) show a plan view, front view, and side view of a fixing hardware 17, which is a modified example 3 of the fixing hardware constituting the wooden building tie-down system 1 of Embodiment 1 according to the present invention, a plan view showing the fixing hardware 17 fixed to the beam member 22, and a front view of that state, respectively.

[0050] As shown in Figures 9(a) to 9(c), the fixing hardware 17 of the modified example consists of a fixing hardware body 17a, which is a square-shaped steel plate with six pin holes 17a1, and nut bodies 17b, 17b, each having a female screw portion 17b1, which are joined to the upper and lower sides of the fixing hardware body 17a by welding or the like.

[0051] Furthermore, in the case of the fixing hardware 17 of the modified example 3, the beam member 22, etc., is provided with a nut fitting recess on its upper side surface into which the lower nut body 17b of the fixing hardware 17 fits, and a rod insertion hole is formed through the fitting recess in the vertical direction through which the upper tie rod 12a passes.

[0052] Then, as shown in Figures 9(d) and (e), the lower nut body 17b of the fixing hardware 17 of Modified Example 3 is fitted into the nut body fitting recess provided on the upper side surface of the beam member 22, and screws 14b or the like are driven into the six pin holes 17a1 of the fixing hardware body 17a to fix the fixing hardware 17 of Modified Example 3 to the upper side surface of the beam member 22. The male threaded portion 12b1 of the lower end of the lower tie rod 12b is screwed into the female threaded portion 17b1 of the upper nut body 17b, while the male threaded portion 12a1 of the upper end of the upper tie rod 12a is screwed into the female threaded portion 17b1 of the lower nut body 17b through the rod insertion hole of the beam member 22. In this way, the lower tie rod 12b of the second floor and the upper tie rod 12a of the first floor can be fixed to the beam member 22 that constitutes the floor of the second floor, similar to the fixing hardware 11 and the fixing hardware 15 and 16 of Modified Examples 1 and 2 described above.

[0053] <Modification of fixing hardware 4> Figures 10(a) to (e) show a plan view, front view, and side view of a fixing hardware 18, which is a modified example 4 of the fixing hardware constituting the wooden building tie-down system 1 of Embodiment 1 according to the present invention, a plan view showing the fixing hardware 18 fixed to the beam member 22, and a front view of that state, respectively.

[0054] As shown in Figures 10(a) to (c), the fixing hardware 18 of the modified example consists of a fixing hardware body 18a made of a square-shaped steel plate with six pin holes 18a1, and a nut body 18b having a female screw portion 18b1 joined only to the upper side surface of the fixing hardware body 18a by welding or the like. As shown in Figure 10(e), two of these are used as a set.

[0055] Furthermore, in the case of the fixing hardware 18 of the modified example 4, it is not necessary to process the beam material 22 with recesses or rod insertion holes.

[0056] Then, as shown in Figures 10(d) and (e), the fixing hardware 18 of Modification 4 is placed against the upper and lower sides of the beam member 22, and screws 14b or the like are driven into the six pin holes 18a1 of the fixing hardware body 18a to secure them. The female threaded portion 18b1 of the nut body 18b of the fixing hardware 18 on the upper side of the beam member 22 is screwed into the male threaded portion 12b1 of the lower end of the lower tie rod 12b, while the male threaded portion 12a1 of the upper end of the upper tie rod 12a is screwed into the female threaded portion 18b1 of the nut body 18b of the fixing hardware 18 on the lower side of the beam member 22. In this way, the lower tie rod 12b of the second floor and the upper tie rod 12a of the first floor can be fixed to the beam member 22 that constitutes the floor of the second floor, similar to the fixing hardware 11 described above and the fixing hardware 15 to 17 of Modifications 1 to 3.

[0057] Furthermore, in the case of the fixing hardware 18 of Modification 4 shown in Figure 10, similar to the case of the fixing hardware 16 of Modification 2, the upper tie rod 12a of the lower floor and the lower tie rod 12b of the upper floor are not connected via the fixing hardware 16.

[0058] <5 Modifications of Fixing Hardware> In the fixing hardware 11 of Embodiment 1 and the fixing hardware 15-18 of Modifications 1-4 described above, dedicated fixing hardware was provided as described above. However, in Modification 5 of the fixing hardware, for example, as shown in Figure 11, only the upper end of the upper tie rod 12a is fixed to the beam members 22-24 by a well-known washer 12c and nut 12d instead of the fixing hardware 11, and the upper tie rod 12a of the lower floor and the lower tie rod 12b of the upper floor are configured so that they are not continuous via the fixing hardware 11.

[0059] Embodiment 2. Next, the tie-down system 1' for wooden buildings of Embodiment 2 according to the present invention will be described. The tie-down system 1' for wooden buildings of Embodiment 2 according to the present invention uses a tie rod fastening fitting 19 as shown in Figure 12 as the tensile force transmission fitting, instead of the tensile force transmission fitting 13 of the tie-down system 1 for wooden buildings of Embodiment 1 which uses a frustoconical washer 13b and a compression coil spring 13c. The configuration of the upper tie rod 12a and lower tie rod 12b, the fixing pin 14a, the fixing fittings 11, 15~18, etc., and their usage methods are the same as those of the tie-down system 1 for wooden buildings of Embodiment 1 described above. Therefore, in the tie-down system 1' for wooden buildings of Embodiment 2, only the configuration and effects of the tie rod fastening fitting 19, which differ from the configuration of the tie-down system 1 for wooden buildings of Embodiment 1 described above, will be explained.

[0060] <Configuration of tie rod fastening hardware 19> Figures 12(a) to 12(c) are a plan view, front view, and side view of the tie rod fastening hardware 19 that constitutes the wooden building tie-down system 1' of Embodiment 2 according to the present invention.

[0061] The tie rod fastening hardware 19 is composed of a box-shaped steel frame 19a, which has a box shape and no front or rear sides, as shown in Figures 12(a) to (c), and a metal inner coupler 19b, outer coupler 19c, tightening ring 19d, coil spring 19e, two nuts 19f, washer 19g, etc., which serve as the tensile force transmission member of the present invention.

[0062] (Box-shaped frame 19a) As shown in Figures 12(a) to (c), the box-shaped frame 19a is formed in a box shape with an upper part 19a1 which serves as a tie rod fixing part and has a female threaded part 19a11 into which the male threaded part 12a1 at the tip, which is the lower end of the upper tie rod 12a is screwed; a lower part 19a2 which has a tie rod through hole 19a21 through which the lower tie rod 12b passes; and a pair of lateral parts 19a3, 19a3 which connect the upper part 19a1 and the lower part 19a2. It forms a working space 19h for tightening nuts 19f and the like, and is open in the front-to-back direction with the front and rear sides omitted. However, since the upper tie rod 12a is inserted and joined by the nut 19f, the tensile force transmission hardware 13 will fall by its own weight when contraction or sinking occurs, so it is not necessary for the female screw portion 19a11 to be formed on the upper part 19a1 of the box-shaped frame 19a.

[0063] (Inner coupler 19b) The inner coupler 19b is a cylindrical nut having a male threaded portion 19b1 on its outer circumference and a female threaded portion 19b2 on its inner circumference that screws onto the male threaded portion 12b1 of the lower tie rod 12b, as shown in Figures 13 and 14. In this embodiment, the screw pitch P1 of the male threaded portion 19b1 on the outer circumference (see Figures 13 and 14) is made larger than the screw pitch P2 of the female threaded portion 19b2 on the inner circumference (see Figure 13), that is, the screw pitch of the male threaded portion 12b1 of the lower tie rod 12b.

[0064] (Outer coupler 19c) The outer coupler 19c is a nut cylinder having a female threaded portion 19c1 that screws onto the male threaded portion 19b1 of the inner coupler 19b, as shown in Figure 13, and has a coil spring lower end insertion recess 19c2 (see Figure 15) at the lower end of its outer surface into which the lower end portion 19e2 of the coil spring 19e is inserted and fixed.

[0065] (Tightening ring 19d) The tightening ring 19d is a disc-shaped ring with a tie rod through hole 19d1 through which the lower tie rod 12b passes, as shown in Figure 15, etc., and has a coil spring upper end insertion recess 19d2 on its outer circumferential surface into which the upper end 19e1 of the coil spring 19e is inserted and fixed, and is provided on the upper part of the coil spring 19e.

[0066] As shown in Figure 15, the tightening ring 19d is provided with a bolt hole 19d3 that is perpendicular to the tie rod through hole 19d1, that is, it penetrates from the outer surface of the tightening ring 19d to the tie rod through hole 19d1. The bolt thread portion 19d41 of the tightening ring fixing bolt 19d4 is screwed into the bolt hole 19d3, and as the tightening ring fixing bolt 19d4 rotates, the tip of the bolt thread portion 19d41 protrudes into the tie rod through hole 19d1 and comes into contact with the male thread portion 12b1 of the lower tie rod 12b, thereby fixing the tightening ring 19d to the lower tie rod 12b.

[0067] (Coil spring 19e) As shown in Figure 15, the upper end 19e1 of the coil spring is inserted into and fixed in the coil spring upper end insertion recess 19d2 of the tightening ring 19d, while the lower end 19e2 is inserted into and fixed in the coil spring lower end insertion recess 19c2 of the outer coupler 19c, and is provided so as to cover the entire outer circumference of the outer coupler 19c.

[0068] (Nut 19f) As shown in Figures 12 and 13, the nut 19f is a nut that is screwed onto the male threaded portion 12a1 of the upper tie rod 12a and the male threaded portion 12b1 of the lower tie rod 12b. The tie rod fastening hardware 19 transmits the tensile force acting between the upper tie rod 12a and the lower tie rod 12b. The male threaded portion 12a1 of the upper tie rod 12a is screwed onto the female threaded portion 19a11 of the upper part 19a1 and then fastened with the nut 19f.

[0069] Furthermore, the nut 19f, which is screwed onto the male threaded portion 12b1 of the lower tie rod 12b above the tightening ring 19d, is a component that serves to prevent the tightening ring 19d from loosening in this embodiment. Therefore, it is not expected to have tensile strength, and a low-strength nut is acceptable.

[0070] (Washer 19g) The washer 19g is used when attaching the tie rod fastening hardware 19 to the base 21 or beam 23, and the lower end of the outer coupler 19c abuts against it.

[0071] <Installation method and operation of the tie rod fastening fitting 19 according to Embodiment 2 of the present invention> Next, the installation method, operation, and resetting of the tie rod fastening hardware 19 in the wooden building tie-down system 1' of Embodiment 2 according to the present invention will be described with reference to the drawings.

[0072] (Installation method for tie rod fastening hardware 19) First, the upper part 19a1 of the box-shaped frame 19a of the tie rod fastening hardware 19 in Embodiment 2 is fixed to the upper tie rod 12a by fastening nuts 13d, similar to the case of the upper part 13a1 of the box-shaped frame 13a of the tensile force transmission hardware 13 in Embodiment 1, with the male threaded part 12a1 of the upper tie rod 12a screwed into the female threaded part 19a11 of the upper part 19a1 and fastened with fastening nuts 13d. Therefore, the upper part 19a1 does not follow the shrinkage or sinking of beam members 22-24 or columns 25-27, etc.

[0073] In contrast, as shown in Figure 12, etc., on the lower side 19a2 of the box-shaped frame 19a, the lower tie rod 12b passes through the tie rod through hole 19a21, and a coil spring 19e, etc., is provided. Therefore, similar to the case of the tensile force transmission hardware 13 in Embodiment 1, the tie rod fastening hardware 19 on the lower side 19a2 of the box-shaped frame 19a follows the contraction and sinking of beam members 22-24 and column members 25-27, etc.

[0074] Therefore, in the wooden building tie-down system 1' of Embodiment 2, in order to install the tie rod fastening hardware 19 between the upper tie rod 12a and the lower tie rod 12b, first, as shown in Figure 14, a washer 19g is passed through the lower tie rod 12b which penetrates the lower part 19a2 of the box-shaped frame 19a and protrudes into the working space 19h, and then the inner coupler 19b is lowered and the lower tie rod 12b is passed through the inner coupler 19b. At this time, since the inner coupler 19b is provided with a female threaded portion 19b2 (see Figure 13), the inner coupler 19b is lowered while rotating, and the female threaded portion 19b2 is screwed into the male threaded portion 12b1 of the lower tie rod 12b. The inner coupler 19b is lowered while rotating until the lower end of the inner coupler 19b contacts the upper surface of the washer 19g, as shown in Figure 15, and is fixed to the lower part 19a2 of the box-shaped frame 19a via the washer 19g.

[0075] When the lower end of the inner coupler 19b contacts the upper surface of the washer 19g, as shown in Figure 15, the tightening ring 19d and the outer coupler 19c are connected and integrated via the coil spring 19e from above, and then lowered towards the upper end of the male threaded portion 12b1 of the lower tie rod 12b.

[0076] First, the male threaded portion 12b1 of the lower tie rod 12b passes through the outer coupler 19c, and the female threaded portion 19c1 of the outer coupler 19c screws onto the male threaded portion 19b1 of the inner coupler 19b, which was screwed onto the male threaded portion 12b1 of the lower tie rod 12b. The worker then rotates the outer coupler 19c, the tightening ring 19d, and the coil spring 19e to lower the outer coupler 19c until the lower end of the outer coupler 19c contacts the upper surface of the washer 19g. At this time, although the female threaded portion 19c1 of the outer coupler 19c screws onto the male threaded portion 19b1 of the inner coupler 19b, the tightening ring 19d only passes over the lower tie rod 12b and does not screw onto the male threaded portion 12b1 of the lower tie rod 12b, so the coil spring 19e is not compressed.

[0077] Next, the worker lowers the nut 19f from above the tightening ring 19d onto the upper end of the male threaded portion 12b1 of the lower tie rod 12b, and rotates the nut 19f to screw it onto the male threaded portion 12b1 of the lower tie rod 12b, as shown in Figure 16(a).

[0078] Furthermore, as shown in Figure 16(a), the worker presses down the tightening ring 19d to compress the coil spring 19e, then rotates the nut 19f to lower it, and as shown in Figure 16(b), screws the nut 19f down to the point where it does not interfere with the tightening ring 19d, bringing it close to the top surface of the tightening ring 19d.

[0079] It is also possible to compress the coil spring 19e by bringing the nut 19f into contact with the upper surface of the tightening ring 19d and lowering the tightening ring 19d by the rotation of the nut 19f. However, in this case, the nut 19f receives the elastic force of the coil spring 19e as a reaction force via the tightening ring 19d, which worsens workability. Therefore, the coil spring 19e is compressed by pushing down the tightening ring 19d. As a result, when compressing the coil spring 19e, the elastic force of the coil spring 19e hardly acts in the tightening direction of the nut 19f, thus improving the workability of tightening the nut 19f.

[0080] Then, after compressing the coil spring 19e, the tightening ring fixing bolt 19d4 provided on the tightening ring 19d is used as a handle to grasp it, or the tightening ring 19d is grasped directly and the tightening ring 19d is rotated half a turn or one or two turns relative to the lower tie rod 12b to twist the coil spring 19e, and the restoring force (elastic force) of the twisted coil spring 19e imparts a rotational force to the outer coupler 19c relative to the inner coupler 19b.

[0081] Once the compression and twisting of the coil spring 19e is complete, the worker tightens and secures the tightening ring 19d to the inner coupler 19b by sandwiching the tightening ring 19d with the nut 19f, while maintaining the compressed and twisted state of the tightening ring 19d as shown in Figure 17(a). Then, the tightening ring fixing bolt 19d4 is rotated to fix its tip to the male threaded portion 12b1 of the lower tie rod 12b, thereby preventing the tightening ring 19d from loosening.

[0082] This secures the inner coupler 19b, the tightening ring 19d, and the nut 19f to the lower tie rod 12b, completing the installation of the tie rod fastening hardware 19 in this embodiment.

[0083] (Operation of tie rod fastening hardware 19) After the tie rod fastening hardware 19 of Embodiment 2 is installed between the upper tie rod 12a and the lower tie rod 12b on each floor, the beam members 22-24 and column members 25-27 shrink due to drying and aging changes such as sinking due to the weight of the building, and as shown in Figure 17(b), the upper end of the lower tie rod 12b protrudes from the lower part 19a2 of the box-shaped frame 19a by an amount α, and the tightening ring 19d Since it is fixed to the lower tie rod 12b, it rises together with the lower tie rod 12b by an amount of lift α, while the coil spring 19e extends due to its restoring force as it tries to return to its original shape from a compressed and torsioned state, and at the same time rotates the lower end 19e2 of the coil spring 19e so that the torsion is eliminated, causing the outer coupler 19c fixed to the lower end 19e2 of the coil spring 19e to rotate relative to the inner coupler 19b.

[0084] Then, the outer coupler 19c rotates relative to the inner coupler 19b, causing the outer coupler 19c to lower as shown in Figure 17(b), pressing the washer 19g against the lower part 19a2 of the box-shaped frame 19a, and following the upward movement of the upper end of the lower tie rod 12b.

[0085] As a result, even if the upper end of the lower tie rod 12b rises by an amount α due to the contraction of beam members 22-24 and column members 25-27, etc. (see Figure 1, etc.), as shown in Figure 17(b), and the gap between the nut 19f and washer 19g screwed onto the upper end of the lower tie rod 12b widens, the restoring force (elastic force) of the coil spring 19e, which is in a compressed and torsional state, causes the outer coupler 19c to rotate and descend relative to the inner coupler 19b, following the widening of the gap between the nut 19f and washer 19g, thereby preventing the upper end of the lower tie rod 12b from rising.

[0086] (Tie rod fastening hardware 19 reset) As described above, when the upper end of the lower tie rod 12b, to which the tie rod fastening fitting 19 is screwed, lifts up, the tie rod fastening fitting 19 operates, and the restoring force of the coil spring 19e, which is in a compressed and torsional state, causes the outer coupler 19c to rotate and descend, pushing down the washer 19g and preventing the lower tie rod 12b from lifting up. However, this weakens or eliminates the compressed and torsional state of the coil spring 19e, so the tie rod fastening fitting 19 will not function properly when the upper end of the lower tie rod 12b lifts up further.

[0087] Therefore, as shown in Figure 17(b), if the tie rod fastening fitting 19 is functioning correctly, the worker will reset the tie rod fastening fitting 19 as follows.

[0088] Specifically, during inspections, etc., the worker first loosens the tightening ring fixing bolt 19d4 of the tightening ring 19d of the tie rod fastening fitting 19, which has been operating normally and whose compression and torsion states have weakened or disappeared, as shown in Figure 17(b), by rotating it in the reverse direction as shown in Figure 18(a), thereby freeing the tightening ring 19d that was fixed to the lower tie rod 12b. Then, the worker rotates the inner coupler 19b and the outer coupler 19c again to tighten them by an amount α (see Figure 17(b)) that lifts the upper end of the lower tie rod 12b, while simultaneously pushing down the tightening ring 19d to compress the coil spring 19e. Furthermore, the worker rotates the tightening ring 19d half a turn or one or two turns relative to the lower tie rod 12b to twist the coil spring 19e and apply rotational force to the outer coupler 19c.

[0089] Subsequently, as in the case of installing the tie rod fastening fitting 19 as described above, the tightening ring 19d is fixed by sandwiching it between the nut 19f and the inner coupler 19b as shown in Figure 18(b). Then, the tightening ring fixing bolt 19d4 is rotated to bring the tip of the bolt threaded portion 19d41 into contact with the male threaded portion 12b1 of the lower tie rod 12b, thereby fixing the tightening ring 19d to the lower tie rod 12b, and the readjustment of the tie rod fastening fitting 19 is completed. This makes it possible to accommodate the lifting of the upper end of the lower tie rod 12b to which the tie rod fastening fitting 19 is connected.

[0090] <Summary of the wooden building tie-down system 1' of Embodiment 2 according to the present invention> As described above, the wooden building tie-down system 1' of Embodiment 2 according to the present invention is configured as shown in Figures 12 and 13, etc., instead of the tensile force transmission hardware 13 of the wooden building tie-down system 1 of Embodiment 1, and uses a tie rod fastening hardware 19 as the tensile force transmission hardware, which absorbs the tensile and compressive forces acting between the upper tie rod 12a and the lower tie rod 12b and follows the lifting of the lower tie rod 12b.

[0091] Therefore, in the wooden building tie-down system 1' of Embodiment 2 according to the present invention, similar to the wooden building tie-down system 1 of Embodiment 1, the tensile force acting between the upper tie rod 12a and the lower tie rod 12b can be reliably transmitted by the tie rod fastening hardware 19 provided on each floor. Furthermore, even if the distance between the tips of the tie rods 12a and 12b decreases due to shrinkage or sinking of timber such as beams 22-24 and columns 25-27 on each floor, the tie rod fastening hardware 19 provided on each floor from the 1st to the 3rd floor can independently perform their follow-up function, thereby reliably preventing the lower tie rod 12b on each floor from floating up.

[0092] In particular, the tie rod fastening hardware 19 constituting the wooden building tie-down system 1' of Embodiment 2 of the present invention comprises a box-shaped frame 19a, an inner coupler 19b having a male threaded portion 19b1 on its outer circumference and a female threaded portion 19b2 on its inner circumference that screws onto the male threaded portion 12b1 of the lower tie rod 12b, an outer coupler 19c having a female threaded portion 19c1 that screws onto the male threaded portion 19b1 of the inner coupler 19b, a tightening ring 19d provided with a tie rod through hole 19d1 for the lower tie rod 12b to pass through, and fixing the tightening ring 19d to the lower tie rod 12b. The system includes a nut 19f, a coil spring 19e whose upper end is fixed to the tightening ring 19d and whose lower end is fixed to the outer coupler 19c, and which is provided to cover the outer circumferential surface of the outer coupler 19c. The tightening ring 19d has a bolt hole 19d3 that penetrates from its outer circumferential surface to the tie rod through hole 19d1, and the bolt hole 19d3 is made up of a tightening ring fixing bolt 19d4 whose tip protrudes from the tie rod through hole 19d1 and abuts against the lower tie rod 12b, thereby fixing the tightening ring 19d to the lower tie rod 12b.

[0093] Therefore, the tip of the male threaded portion 12b1 of the lower tie rod 12b is passed through the tie rod through hole 19a21 of the lower part 19a2 of the box-shaped frame 19a, through the washer 19g, the inner coupler 19b, and the tightening ring 19d. Furthermore, by pressing down the tightening ring 19d, the coil spring 19e is compressed, and by rotating the tightening ring 19d, a torsional force is applied to the coil spring 19e, and the nut 19f is tightened, and further tightening ring By fixing the tightening ring 19d to the lower tie rod 12b with the fixing bolt 19d4, when the lower tie rod 12b connected to the tie rod fastening fitting 19 rises, the coil spring 19e extends and at the same time the torsion of the coil spring 19e is eliminated. This rotates the outer coupler 19c so that the outer coupler 19c is lowered relative to the inner coupler 19b, thereby preventing the lower tie rod 12b from rising.

[0094] Furthermore, the outer coupler 19c, which rotates and descends due to the extension of the coil spring 19e, is screwed into the inner coupler 19b, and the inner coupler 19b is screwed into the male threaded portion 12b1 of the lower tie rod 12b. As a result, the entire couplers of the inner coupler 19b and the outer coupler 19c are installed without eccentricity relative to the lower tie rod 12b. Therefore, even if the lower tie rod 12b lifts up and the gap between the lower part 19a2 of the box-shaped frame 19a and the washer 19g becomes larger, the outer coupler 19c can smoothly rotate and descend relative to the inner coupler 19b due to the extension of the coil spring 19e, and the tie rod fastening hardware 19 can perform its intended function without any problems, thereby reliably preventing the lower tie rod 12b from lifting up.

[0095] In particular, the tie rod fastening fitting 19 of Embodiment 2 has an inner coupler 19b having a male threaded portion 19b1 that screws into the female threaded portion 19c1 of the outer coupler 19c, and a female threaded portion 19b2 that screws into the male threaded portion 12b1 of the lower tie rod 12b, and the upper end of the coil spring 19e is fixed to the tightening ring 19d, so that the constant competition between the screwed portions of the outer coupler 19c and the inner coupler 19b is reduced, the frictional resistance between the outer coupler 19c and the inner coupler 19b is reduced, and smooth rotation can be maintained.

[0096] Furthermore, in the second embodiment, the tie rod fastening fitting 19 has a female threaded portion 19b2 on the inner circumferential surface of the inner coupler 19b that screws onto the male threaded portion 12b1 of the lower tie rod 12b. As a result, the inner coupler 19b is no longer installed eccentrically with respect to the lower tie rod 12b. This eliminates the frictional resistance caused by the threaded portions of the outer coupler 19c and the inner coupler 19b constantly competing, as well as the increased frictional resistance caused by the inner coupler 19b contacting the lower tie rod 12b at an angle. Consequently, the outer coupler 19c can rotate smoothly relative to the inner coupler 19b.

[0097] Furthermore, since the inner coupler 19b has a female threaded portion 19b2 on its inner circumferential surface that screws onto the male threaded portion 12b1 of the lower tie rod 12b, the female threaded portion 19b2 of the inner coupler 19b screws onto the male threaded portion 12b1 of the lower tie rod 12b, thus integrating the member with the tracking function and the member that bears the load into one unit. Therefore, in the initial installation state where the lower end of the inner coupler 19b is pressed against the lower part 19a2 of the box-shaped frame 19a via the washer 19g, stress is transmitted in the order of the lower part 19a2 of the box-shaped frame 19a to the inner coupler 19b and then the lower tie rod 12b. When the lower part 19a2 of the box-shaped frame 19a protrudes, causing the outer coupler 19c, coil spring 19e, etc. to follow, the stress is transmitted in the order of the lower part 19a2 of the box-shaped frame 19a to the outer coupler 19c, inner coupler 19b, and then the lower tie rod 12b. As a result, the number of components in the stress transmission path is reduced, making it less likely for malfunctions to occur. Furthermore, even when the components follow, stress can be transmitted at a position as close as possible to the lower part 19a2 of the box-shaped frame 19a.

[0098] Furthermore, in the tie rod fastening fitting 19 of Embodiment 2, the screw pitch P1 of the male screw portion 19b1 on the outer surface of the inner coupler 19b is formed to be larger than the screw pitch P2 of the female screw portion 19b2 of the inner coupler 19b.

[0099] Therefore, because the screw pitch P1 of the male screw portion 19b1 on the outer circumference of the inner coupler 19b and the screw pitch P2 of the female screw portion 19b2 are different, the screwed portions of the outer coupler 19c and the inner coupler 19b are less likely to be constantly in a state of competition, and the frictional resistance between the outer coupler 19c and the inner coupler 19b is reduced, so that the smooth rotation of the outer coupler 19c and the like can be maintained.

[0100] In the description of Embodiment 2 above, the tie rod fastening hardware 19 was described as being connected to the lower tie rod 12b that penetrates the sill 21 and beams 22, 23 joined between the columns 25-27 of the wooden building 2. However, the present invention is not limited to this, and of course, the tie rod fastening hardware 19 may be configured to follow the reduction of horizontal members such as the sill 21 and beams 22, 23, for example, by installing the upper tie rod 12a and lower tie rod 12b that constitute the wooden building tie-down system 1' horizontally between multiple columns 25-27 on each floor, that is, parallel to the sill 21 and beams 22, 23, etc., rather than vertically, and connecting the tie rod fastening hardware 19 to the upper tie rod 12a and lower tie rod 12b installed horizontally, and by configuring the tie rod fastening hardware 19 to mainly follow the reduction of horizontal members such as the sill 21 and beams 22, 23. [Explanation of symbols]

[0101] 1.1' Tie-down system for wooden buildings 11 Fixing hardware 11a, 11b Female threaded section 11c pin hole 12a Upper tie rod 12a1,12a2 Male thread part 12b Lower tie rod 12b1,12b2 Male thread part 12c washer 12d nut 13. Tensile force transmission hardware 13a Box-shaped frame 13a1 Upper part 13a11 Female thread section 13a2 Lower part 13a21 Cone-shaped recess 13a22 Tie rod through hole 13a3 Lateral view 13b. Truncated cone washer (tensile force transmission member) 13b1 Tie rod through hole 13b2 Outer surface of a frustoconical shape 13c Compression Coil Spring 13d Fastening nut (tensile force transmission member) 13e Working space 14a Fixing pin 14b Bis 15 Fixing hardware (Variation 1) 16 Fixing hardware (Variation 2) 17 Fixing hardware (Variation 3) 18 Fixing hardware (Variation 4) 19. Tie rod fastening hardware (tensile force transmission hardware) 19a Box-shaped frame 19a1 Upper part 19a11 Female thread section 19a2 Lower part 19a21 Tie rod through hole 19b Inner coupler (tensile force transmission member) 19b1 Male threaded section 19b2 ​​Female thread section 19c Outer coupler (tensile force transmission member) 19c1 Female thread section 19c2 Coil spring lower end insertion recess 19d Clamping ring (tensile force transmission member) 19d1 Tie rod through hole 19d2 Coil spring upper end insertion recess 19d3 bolt hole 19d4 Tightening ring fixing bolt 19e Coil spring (tensile force transmission member) 19e1 Upper end 19e2 Bottom end 19f Nut (Tensile force transmission member) 19g Washer (Tensile Force Transmission Member) 19h Working space 2 Wooden buildings 21 Base 22,23,24 Beam material 25,26,27 Pillar material

Claims

1. Multiple fastening hardware pieces are fixed to wooden structural members that are spaced apart and facing each other in a wooden building, A pair of tie rods, each having its rear end fixed to the aforementioned plurality of fixing hardware, A tensile force transmission fitting connected to the tip of each of the pair of tie rods, which absorbs the contraction between the tips of the pair of tie rods and transmits the tensile force between the pair of tie rods, A tie-down system for wooden buildings, characterized by having the following features.

2. In the wooden building tie-down system according to claim 1, The aforementioned tensile force transmission hardware is A box-shaped frame having a tie rod fixing portion to which the tip of one of the pair of tie rods is fixed, and a tie rod passing portion having a tie rod through hole through which the tip of the other of the pair of tie rods passes, A tensile force transmission member is provided between the tip of the other tie rod that passes through the tie rod through hole of the box-shaped frame and the tie rod passing portion, and absorbs the contraction between the pair of tie rod tips and transmits the tensile force between the pair of tie rods, A tie-down system for wooden buildings, characterized by having the following features.

3. In the wooden building tie-down system according to claim 2, The box-shaped frame has a tapered inner surface recess having an inner surface that narrows downwards, and the tie rod through hole is provided in the center thereof, The tensile force transmission member is A tie-down system for wooden buildings, characterized in that it has a tapered outer surface that contacts the inner surface of the tapered inner surface recess, and has a tie-rod through-hole in the center through which the tip of the other tie rod passes, is housed in the tapered inner surface recess of the box-shaped frame, and when a tensile force is applied to the box-shaped frame, the outer surface of the tensile force transmission member is pressed by the tapered inner surface of the tapered inner surface recess, and the tie-rod through-hole is elastically deformed to narrow, thereby clamping the other tie rod and transmitting the tensile force to the other tie rod.

4. In the wooden building tie-down system described in claim 3, A tie-down system for wooden buildings is characterized in that a compression coil spring is provided between the upper surface of the tensile force transmission member and a fastening nut that screws onto the male threaded portion of the other tie rod tip passing through the tie rod through hole of the tensile force transmission member, thereby pressing the tensile force transmission member toward the tapered inner surface recess.

5. In the wooden building tie-down system according to claim 2, The tensile force transmission member is An inner coupler having a female threaded portion that screws into the male threaded portion at the tip of the other tie rod, and having a male threaded portion on its outer circumference, An outer coupler having a female threaded portion that screws into the male threaded portion of the inner coupler, A tightening ring having a tie rod through hole for the other tie rod, and installed above the inner coupler and the outer coupler, The coil spring is provided such that its upper end is fixed to the clamping ring and its lower end is fixed to the outer coupler, and it covers the outer circumferential surface of the outer coupler. A tie-down system for wooden buildings, characterized in that the tightening ring is provided with a bolt hole that penetrates from its outer circumference to the tie rod through hole, and a tightening ring fixing bolt is provided which is inserted into the bolt hole and screwed in, with its tip protruding from the tie rod through hole and contacting the other tie rod to fix the tightening ring to the other tie rod.

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