Connecting structures

Abstract

To provide a connection structure that can ensure tenacity when excessive tensile loads are applied in various types of wooden structures including wooden buildings, and is also cost-effective and easy to construct.SOLUTION: A connection structure between adjacent one material 71 and the other material 81 uses a connecting bolt 21, intermediary hardware 31, 32, and a buffer 11, the intermediary hardware 31, 32 receive axial force generated at the connecting bolt 21, and the buffer 11 is sandwiched between the connecting bolt 21 and the intermediary hardware 31, 32, so that the axial force is transmitted through the buffer 11 toward the intermediary hardware 31, 32. Furthermore, a surface that transmits the axial force from the buffer 11 to the intermediary hardware 31, 32 is secured at an outer edge of the buffer 11, with a void 28 inside it, so that the buffer 11 deforms and enters the void 28 to ensure tenacity when excessive axial force is generated. In addition, ordinary objects can be used for the connecting bolts 21, etc., and components to be embedded in one material 71, etc., are the same as those used in the past, making them cost-effective and easy to construct.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a connecting structure for installing members in various wooden structures, including wooden buildings. [Background technology]

[0002] To ensure the strength of a wooden building, the components that make up its framework must be firmly connected to other components and foundations. For this reason, techniques such as fitting tenons and mortise holes have long been used to connect components, but in recent years, metal parts such as bolts and shafts have been used instead. When a tensile load is applied to such metal components, elastic deformation occurs according to the load. However, once the stress acting on the metal component exceeds its "yield strength," plastic deformation occurs, and the maximum stress measured before fracture becomes its "tensile strength." Furthermore, the value obtained by dividing "yield strength" by "tensile strength" is called the "yield ratio."

[0003] In metal parts such as bolts, if the difference between the "yield strength" and "tensile strength" is small, the "yield ratio" will be close to 1. However, when excessive tensile loads are applied to such metal parts, they will immediately fracture after slight plastic deformation. If such parts are used in the connecting structure of a wooden building, they will easily fracture without exhibiting toughness against excessive tensile loads, which could cause the components to separate and result in major damage. Conversely, if the difference between the "yield strength" and "tensile strength" is large, the "yield ratio" will be close to 0. However, when excessive tensile loads are applied to such metal parts, they will maintain toughness even after plastic deformation occurs before fracture. If such parts are used in the connecting structure of a wooden building, they are expected to be able to tolerate deformation while preventing separation of the components and avoid major damage.

[0004] Techniques for preventing large-scale damage to wooden buildings by deforming metal components have been proposed for some time, including Patent Document 1 (see below). This document discloses a connecting structure for integrating two members, such as a column and a beam. An embedded shaft is embedded in one of the two members, and a fixed shaft is embedded in the other. The embedded shaft and the fixed shaft are then concentrically aligned, and a tension bolt is inserted through them, drawing the embedded shaft and the fixed shaft together. The tension bolt has a deformation region with a low elastic modulus in a section of its shaft. This deformation region induces elastoplastic deformation after connecting the two members, preventing damage to the connecting structure. The document also discloses the use of rolled steel bars (SNR) for building construction, which are joined using a friction welding method or similar to create a tension bolt.

[0005] The following Patent Document 2 discloses a connecting structure with adjustable rigidity and strength. This document also integrates two components, such as a pillar and a beam, but in one of the two components, a rod-shaped embedding tool and a buffer shaft are embedded in series, with the embedding tool positioned at the back and integrated with the component. The buffer shaft's central portion is made smaller in diameter to induce deformation, and a fixing bolt is threaded into the buffer shaft, so the two connected components maintain a state of mutual attraction via the buffer shaft. As a result, the buffer shaft's deformation alleviates impact loads, and the rigidity and strength can be adjusted by changing the shape of the buffer shaft.

[0006] Furthermore, Patent Document 3 discloses a reinforcing device that can maintain the connection between two components even when the lag screw at the connection between the components can no longer withstand the tensile load. In this device, lag screws are embedded in both components, and a stud bolt is inserted through the concentrically aligned lag screws. The two components are tightly attached by tightening inner nuts threaded onto both ends of the stud bolt. In addition, a contact plate, a crown body, and an outer nut are used. The contact plate is in contact with the components, surrounding the end face of the lag screw. The crown body has a stud bolt inserted into its center, and its end face is in contact with the contact plate. When the outer nut is threaded onto the stud bolt, the crown body absorbs the axial force, and the contact plate presses against the components. By using the contact plate, crown body, and outer nut in this way, the connection between the two components can be maintained even if the lag screw is no longer able to perform its intended function for some reason. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-108893 [Patent Document 2] Patent Publication No. 2021-195861 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-245477 Summary of the Invention [Problem to be solved by the invention]

[0008] As mentioned above, it is desirable for metal parts such as bolts used in the connecting structures of wooden buildings to have a yield ratio as close to 0 as possible so that they can maintain sufficient toughness against excessive tensile loads. This can be achieved by using a technology such as that described in Patent Document 1, which provides a deformation region in a section of the bolt (tension bolt). However, using specialized bolts as described in this document poses challenges in terms of cost and procurement, so it is desirable to develop technology that ensures toughness using parts other than bolts, allowing ordinary bolts to be used as is.

[0009] In Patent Document 2, the embedding tool and the buffer shaft are separated, making it easy to adjust the rigidity and strength, and ordinary bolts (fixing bolts) can be used. However, this connection structure requires the embedding tool to be embedded deeper, and increases the amount of work required during construction, such as connecting the embedding tool and the buffer shaft. Furthermore, depending on the shape of the components, it may not be possible to ensure the length required to embed the embedding tool and the buffer shaft in series. Therefore, it is desirable to develop a technology that can ensure toughness without increasing the number of embedded metal parts.

[0010] The present invention was developed based on these circumstances, and aims to provide a connecting structure that can ensure toughness when subjected to excessive tensile loads in various wooden structures, including wooden buildings, and that is also cost-effective and easy to install. [Means for solving the problem]

[0011] To solve the above problems No. 1The invention relates to a connecting structure between adjacent one member and the counterpart member, which uses a connecting bolt, an intermediate metal, and a buffer body. The connecting bolt is positioned so as to maintain a state in which the one member and the counterpart member are attracted to each other. The intermediate metal is positioned at the end of the connecting bolt to receive the axial force, and the intermediate metal has a hole into which the connecting bolt is inserted. The buffer body is positioned between the connecting bolt and the intermediate metal, and the axial force generated in the connecting bolt is transmitted to the intermediate metal via the buffer body. The connecting bolt is inserted into the buffer body. The surface of the buffer body that transmits the axial force generated in the connecting bolt to the intermediate metal is provided at the outer edge of the buffer body, and the inside of this surface is a gap. When an excessive axial force is generated in the connecting bolt, the buffer body deforms and enters the gap before the connecting bolt deforms.

[0012] The connecting structure of the present invention was developed for installing components that constitute the framework of a wooden building, such as a column and a beam, a foundation and a column, or two beams. Of the two components to be connected, one is referred to as the "first member" and the other as the "second member." The first member and the second member may be in surface contact with each other, or may not be in contact with each other because some part is sandwiched between them. Note that the first member is assumed to be any type of wood, but the second member is not limited to any type of wood and may be a concrete structure such as a foundation or a metal part such as a steel frame.

[0013] Furthermore, this invention is premised on the use of three elements: connecting bolts, intermediate metal fittings, and buffers. Of these, the connecting bolts function to maintain the state in which the one material and the other material are attracted to each other, and are therefore necessarily arranged in the direction in which the one material and the other material are attracted to each other. However, the connecting bolts can be arranged in any manner, and one connecting bolt is not necessarily inserted into both the one material and the other material. Different connecting bolts may be arranged on the one material side and the other material side, and the two connecting bolts may be connected by some kind of part. Note that the connecting bolts may be headed bolts or stud bolts.

[0014] An intermediate hardware is a part that restrains the end of a connecting bolt, and its function is to receive the axial force generated by tightening the connecting bolt and transmit it to one or the other material. For this reason, an intermediate hardware is provided with a center hole for the connecting bolt to pass through. The center hole is simply a hole for the connecting bolt to pass through, and is not threaded with the connecting bolt. Furthermore, there is no direct contact between the intermediate hardware and the connecting bolt. Note that intermediate hardware often takes the same form as various metal parts that have been used traditionally, and in the case of a connecting structure in which a column is installed on a foundation, the column base hardware corresponds to the intermediate hardware.

[0015] The buffer is located between the connecting bolt and the intermediate hardware, and its function is to transmit the axial force generated in the connecting bolt to the buffer. The connecting bolt is also inserted into the buffer. Therefore, if the connecting bolt is a headed bolt and an intermediate hardware is placed on the head side, the buffer is placed adjacent to the head of the connecting bolt, just like a normal washer. The side of the buffer opposite the connecting bolt head is in contact with the intermediate hardware to transmit the axial force, which inevitably generates a compressive load on the buffer. However, the majority of the buffer does not come into contact with the intermediate hardware; only the outer edge of the buffer is in contact, and the area inside is not in contact with anything else.

[0016] The shape of the buffer can be freely chosen, but it can be a simple disk with a hole in the center, like a regular washer. If a stud bolt is used as the connecting bolt, a nut is threaded onto the connecting bolt and the buffer is placed adjacent to this nut, making it possible to transmit the axial force generated in the connecting bolt. Even if the connecting bolt is a headed bolt, when an intermediate hardware is placed at the tip of the bolt, the buffer is placed adjacent to the threaded nut, just like when using a stud bolt as described above.

[0017] The gap is simply a space adjacent to the buffer body, and is provided to allow for elastic-plastic deformation of the buffer body. Therefore, the gap must be adjacent to the buffer body, and it must be positioned in the direction in which the buffer body is deformed by the axial force generated in the connecting bolt. As mentioned above, only the outer edge of the buffer body will come into contact with the intermediate metal, but the area inside this contact area becomes a gap, and the connecting bolt will pass through the gap. However, the shape of the gap is flexible, and it can be formed adjacent to the center hole of the intermediate metal, or it can be formed inside the buffer body.

[0018] The buffer has an area where the load is transmitted from the connecting bolt and an area where the load is transmitted to the intermediate hardware. To ensure smooth deformation of the buffer, these two areas must not overlap in the longitudinal direction of the connecting bolt, and the area where the load is transmitted to the intermediate hardware must be located outside the area where the load is transmitted from the connecting bolt. As a result, the axial force generated in the connecting bolt generates not only a compressive load but also a bending moment and shear load in the buffer, which smoothly induces deformation. Moreover, the amount of deformation of the buffer can be freely adjusted by changing its size and thickness.

[0019] If the connecting bolt is a headed bolt, it is possible to have the head of the bolt come into direct contact with the buffer, but it is also possible to sandwich a regular washer between the two. Unlike the buffer, this washer simply generates a compressive load. However, sandwiching a regular washer in this way may affect the deformation of the buffer. Therefore, it is necessary to take measures such as positioning the area of ​​the buffer that transmits the load toward the intermediate metal outside this washer. In addition, with connecting bolts, the opposite end of the intermediate metal is attached to one or the other material in some way. A specific example is a method in which an embedding tool such as a lag screw is embedded in the one or the other material and the connecting bolt is screwed into it.

[0020] In this connection structure between one member and the counterpart member, a connecting bolt, an intermediate metal member, and a buffer are used. The connecting bolt is positioned so as to maintain the one member and the counterpart member in a state of mutual attraction. The axial force generated by tightening the connecting bolt is transmitted to the intermediate metal member via the buffer. Furthermore, by providing a gap adjacent to the buffer member, the buffer member can deform smoothly. Therefore, when an excessive tensile load acts on the connection structure and an excessive axial force is generated in the connecting bolt, the buffer member deforms and enters the gap before the connecting bolt or other components deform, ensuring sufficient tenacity. Naturally, the strength of each component of the connection structure must be ensured so that deformation due to an excessive tensile load is concentrated on the buffer member. Furthermore, the number of connecting bolts used in a single connection structure can be freely determined.

[0021] No. 2 The invention specifies the shape of the buffer, which is composed of a hollow cylindrical portion and a plate portion that closes one end of the cylindrical portion. The connecting bolt penetrates the plate portion, and the inside of the cylindrical portion is left with a gap. The buffer here is not simply flat, but is composed of a cylindrical portion and a plate portion, and has a height, which leaves a gap inside. The opposite side of the plate portion of the cylindrical portion comes into contact with an intermediate metal piece or the like. When excessive axial force is transmitted from the connecting bolt, the center of the plate portion collapses and enters the gap. Note that multiple such buffers can be arranged in series for one connecting bolt.

[0022] Third The invention specifies the configuration of the buffer body, and is characterized in that the buffer body is formed with a female thread for threading onto the connecting bolt. Considering the case where a stud bolt or the like is used as the connecting bolt, it is desirable to diversify the means for transmitting the axial force generated in the connecting bolt to the buffer body. Therefore, in this invention, by forming a female thread on the buffer body and threading this female thread onto the connecting bolt, it becomes possible to transmit the axial force directly between the connecting bolt and the buffer body. Therefore, even if the connecting bolt is a headed bolt, the buffer body can be placed away from the head. [Effects of the Invention]

[0023] No. 1 In the invention of the present invention, a connecting structure between one member and a counterpart member uses a connecting bolt, an intermediate metal, and a buffer body, and the connecting bolt is positioned so as to maintain a state in which the one member and the counterpart member are attracted to each other, and the axial force generated by tightening the connecting bolt is transmitted to the intermediate metal via the buffer body. Furthermore, by providing a gap adjacent to the buffer body, the buffer body can be deformed without strain. Therefore, when an excessive tensile load acts on the connecting structure and an excessive axial force is generated in the connecting bolt, the buffer body deforms and enters the gap before the connecting bolt or other components deform, ensuring sufficient toughness.

[0024] Normal connecting bolts can be used as they are, making their availability easy, and conventional intermediate hardware can also be used as is in some cases. Furthermore, because the buffer is placed adjacent to the head of the connecting bolt, the various components embedded in the one and the other materials are the same as in conventional connecting structures, resulting in advantages in terms of cost and ease of construction. Furthermore, in this invention, excessive tensile loads are absorbed by elastic-plastically deforming the buffer, so the relationship between load and deformation can be easily adjusted by changing the size and thickness of the buffer, making it easy to impart optimal characteristics to each individual connecting structure.

[0025] No. 2 As in the invention of the present invention, by constructing the buffer body from a cylindrical portion and a plate portion and leaving a gap inside, there is no need to form a gap in the intermediate metal. Therefore, conventional intermediate metal can be used as is, which is advantageous in terms of cost. In addition, by changing the size of the cylindrical portion and the thickness of the plate portion, the relationship between load and deformation can be freely adjusted, and the relationship between load and deformation can be easily optimized in various connection structures.

[0026] ThirdAs in the invention of the present invention, by forming a female thread on the buffer body, the axial force generated in the connecting bolt is transmitted to the buffer body via this female thread, which reduces restrictions on the placement of the buffer body and makes it possible to accommodate a variety of connection structures.In addition, it becomes possible to place multiple buffer bodies in series for one connecting bolt, and by changing the number of buffer bodies placed, the relationship between the axial force and the amount of deformation can be adjusted, improving versatility and flexibility. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view showing a specific example of a connecting structure according to the present invention, in which it is assumed that one member and a counterpart member are connected using a pair of intermediate metal fittings. [Figure 2] 2 is a perspective view showing a process of connecting one member and a counterpart member shown in FIG. 1. FIG. [Figure 3] FIG. 2 is a cross-sectional view showing a state in which the connection between one member and the counterpart member in FIG. 1 has been completed, and the lower part of the figure illustrates a state in which the buffer body is deformed. [Figure 4] This is an oblique view showing a connection structure similar to that shown in Figure 1 above, but in this case the width of the intermediate metal fittings has been narrowed and deformed steel bars are used as the embedding devices. [Figure 5] FIG. 1 is a perspective view showing a specific example of a connecting structure according to the present invention, in which one member is an upright pillar and the other member is a foundation, and it is assumed that the one member and the other member are connected with an intermediate metal member interposed therebetween. [Figure 6] FIG. 6 is a perspective view showing a process of connecting one member and a counterpart member shown in FIG. 5. [Figure 7] FIG. 6 is a cross-sectional view showing a state in which the connection between the one member and the counterpart member in FIG. 5 has been completed, and the lower part of the figure illustrates a state in which the buffer body is deformed. [Figure 8] This is a perspective view showing a connecting structure similar to that shown in Figure 5, but in this case, two buffers with different diameters are incorporated into one connecting bolt. [Figure 9] FIG. 9 is a cross-sectional view showing a state in which the connection between the one member and the counterpart member in FIG. 8 has been completed, and the lower part of the figure illustrates a state in which the buffer body has been deformed. [Figure 10]This is a perspective view showing a connecting structure similar to that shown in Figure 5, but in this case, two buffer bodies of the same shape are incorporated into one connecting bolt. [Figure 11] FIG. 11 is a cross-sectional view showing a state in which the connection between the one member and the counterpart member in FIG. 10 has been completed, and the lower part of the figure illustrates a state in which the buffer body is deformed. [Figure 12] 1 is a perspective view showing an example of the shape of a component constituting the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0028] 1 shows a specific example of a connecting structure according to the present invention, in which it is assumed that one member 71 and a counterpart member 81 are connected using a pair of intermediate metal fittings 31 and 32. In this figure, one member 71 is an upright pillar, and the counterpart member 81 is a beam extending horizontally. Both form the framework of a wooden building and are made by processing various types of wood, such as laminated lumber, into a predetermined shape. Furthermore, the one member 71 and the counterpart member 81 are connected by bringing the end face of the counterpart member 81 into contact with the side surface of the one member 71 and integrating the two intermediate metal fittings 31 and 32.

[0029] The two intermediate metal members 31, 32 are both upright rods, with one intermediate metal member 31 attached to the side of one member 71 and the other intermediate metal member 32 attached to the end of the counterpart member 81. The intermediate metal member 31 attached to one member 71 is composed mainly of a rod body 42 with a rectangular cross section, with a wedge-shaped pointed portion 43 formed at the top and a receiving band 44 integrated into the bottom. The receiving band 44 is bent in a U-shape and attached so as to protrude from the side of the rod body 42, leaving a closed space inside. In addition, a band-shaped plate protrudes from the center of the rod body 42, with a pin hole 46 formed therein. The intermediate metal fitting 32 attached to the counterpart member 81 has a configuration in which the intermediate metal fitting 31 on the one member 71 side is turned upside down, and a receiving band 44 is integrated with the upper part of the rod body 42, a wedge-shaped sharpened portion 43 is formed at the lower part, and a pin hole 46 is provided in the center of the rod body 42.

[0030] When the two intermediate metal fittings 31, 32 are brought close to each other and their sharpened portions 43 are fitted inside the mating receiving band 44, the rods 42 come into contact, enabling horizontal load transmission. At this time, the pin holes 46 of both fittings are aligned concentrically, and a through-pin 48 is driven into them, completely integrating the two intermediate metal fittings 31, 32. Naturally, the sharpened portions 43 and the receiving band 44 are finished in shapes that allow the rods 42 to come into contact with each other without any gaps. The intermediate metal fittings 31, 32 are then attached to the one member 71 and the counterpart member 81 via embedding tools 61. Because the other two intermediate metal fittings 31, 32 are both housed in the receiving grooves 85, the through-pin 48 needs to be driven so as to penetrate the side surface of the counterpart member 81. Therefore, a horizontal hole 86 is formed in the counterpart member 81 at a position that is concentric with the pin holes 46 of the intermediate metal fittings 31, 32.

[0031] The embedding tool 61 in this figure is a general-purpose lag screw, which has a spirally extending ridge 64 formed on its side periphery, a hexagonal head 65 formed on one end face for hooking a tool during installation, and a female thread 68 formed in the center of the head 65. In order to embed the embedding tool 61, pilot holes 74 are drilled in two places, one above the other, on the side of the one member 71, and pilot holes 84 are also drilled in two places, one above the other, on the inner surface of the receiving groove 85 of the counterpart member 81. After embedding the embedding tool 61 in the one member 71, an intermediate metal fitting 31 is placed to cover it, and then a connecting bolt 21 is inserted from the intermediate metal fitting 31 into the female thread 68 of the embedding tool 61, completing the installation of the intermediate metal fitting 31. The same applies to the counterpart member 81. After embedding the embedding tool 61, the intermediate metal fitting 32 is placed in the accommodation groove 85 and the connecting bolt 21 is inserted, thereby completing the installation of the intermediate metal fitting 32.

[0032] The lower right of the figure shows cross sections of intermediate fittings 31 and 32, each of which has two center holes 38 at the top and bottom to receive connecting bolts 21. Also, in rod 42, a larger-diameter storage hole 47 is provided on the opposite side of center hole 38, with gap 28 provided between center hole 38 and storage hole 47. Gap 28 has a smaller diameter than storage hole 47 but a larger diameter than center hole 38. Three different-sized holes are arranged concentrically in a stepped pattern, with gap 28 being large enough to comfortably accommodate the head of connecting bolt 21.

[0033] The buffer 11 is a simple disk-shaped body with a loophole 18 at its center. After inserting the connecting bolt 21 into the loophole 18, the buffer 11 is brought into contact with the head of the connecting bolt 21, allowing it to be used in the same manner as a normal washer. The buffer 11 also fits into the storage holes 47 of the intermediate fittings 31 and 32, and is brought into contact with the inner surfaces of the storage holes 47. Therefore, all of the axial force generated by tightening the connecting bolt 21 is transmitted to the intermediate fittings 31 and 32 via the buffer 11. Furthermore, because the buffer 11 is adjacent to the gap 28, only the outer edges of the buffer 11 come into contact with the intermediate fittings 31 and 32, where the axial force is transmitted.

[0034] During construction, after attaching the intermediate metal fitting 31 to the one member 71 and the intermediate metal fitting 32 to the counterpart member 81, the intermediate metal fittings 31 and 32 are brought into contact with each other and then the through pin 48 is driven in, completing the connection between the one member 71 and the counterpart member 81. If an excessive load is subsequently applied in a direction that separates the one member 71 and the counterpart member 81, a large axial force is generated in the connecting bolt 21, which causes the center of the buffer 11 to deform and enter the gap 28. This deformation of the buffer 11 ensures the tenacity of the connected structure.

[0035] 2 shows the process of connecting one member 71 and the counterpart member 81 in FIG. 1. As shown in the upper part of this figure, an embedding tool 61 is embedded in the side surface of one member 71, and an intermediate metal fitting 31 is arranged so as to cover the embedding tool 61. Furthermore, a connecting bolt 21 is inserted into the buffer body 11, and then the connecting bolt 21 is inserted from the intermediate metal fitting 31 toward the embedding tool 61, thereby attaching the intermediate metal fitting 31 to the one member 71. For the counterpart member 81, an embedding tool 61 is embedded in the inner surface of the accommodation groove 85, and then an intermediate metal fitting 32 is arranged so as to cover the embedding tool 61. Furthermore, after the connecting bolt 21 is inserted into the buffer body 11, the connecting bolt 21 is inserted from the intermediate metal fitting 32 toward the embedding tool 61, thereby attaching the intermediate metal fitting 32 to the counterpart member 81.

[0036] Thereafter, one member 71 is installed in an upright position, and then the counterpart member 81 is lifted up and the intermediate metal fitting 32 on the counterpart member 81 side is placed above the intermediate metal fitting 31 on the one member 71 side. After that, the counterpart member 81 is gradually lowered and the pointed portions 43 of both intermediate metal fittings 31, 32 are fitted inside the receiving bands 44 of the other member, until the rod bodies 42 of the two intermediate metal fittings 31, 32 come into contact with each other, and the one member 71 and the counterpart member 81 are connected. Finally, as shown in the lower part of the figure, the through pins 48 are driven from the side of the counterpart member 81 into the pin holes 46 of the intermediate metal fittings 31, 32, making the two intermediate metal fittings 31, 32 inseparable, and the connection between the one member 71 and the counterpart member 81 is completed.

[0037] Figure 3 shows a cross section of the state in which the connection between one member 71 and the counterpart member 81 in Figure 1 has been completed, with the lower part of the figure depicting a deformed state of the buffer 11. When the connection is completed, the side surface of the one member 71 and the end surface of the counterpart member 81 are in contact, and the two intermediate metal members 31 and 32 maintain contact with each other with their sharpened portions 43 fitting into the receiving bands 44 of the other member. The intermediate metal members 31 and 32 are housed in housing grooves 85, and most of them are covered and hidden by the counterpart member 81, etc. In addition, embedding devices 61 are embedded in both the one member 71 and the counterpart member 81, and the intermediate metal members 31 and 32 are attached to the one member 71 and the counterpart member 81 by inserting connecting bolts 21 from the respective intermediate metal members 31 and 32 toward the embedding devices 61.

[0038] Intermediate metal fittings 31 and 32 are provided with a center hole 38 for inserting connecting bolt 21, adjacent to which is provided a void 28, and adjacent to that is provided a storage hole 47. Center hole 38, void 28, and storage hole 47 are all circular in cross section, aligned concentrically, and aligned in this order. The diameter gradually increases from center hole 38 to storage hole 47, and buffer body 11 fits snugly into storage hole 47. Connecting bolt 21 is fastened while threadedly engaged with embedding tool 61. The head of connecting bolt 21 contacts buffer body 11, and the outer edge of buffer body 11 contacts the inner surface of storage hole 47 of intermediate metal fittings 31 and 32. Therefore, the head of connecting bolt 21 does not come into direct contact with intermediate metal fittings 31 and 32. Because the head of connecting bolt 21 is embedded in storage hole 47, it does not interfere with contact between intermediate metal fittings 31 and 32.

[0039] Like a normal washer, buffer 11 contacts the head of connecting bolt 21, but because the opposite side of buffer 11 is adjacent to gap 28, only the outer edge of buffer 11 contacts intermediate fittings 31 and 32. Furthermore, gap 28 is intentionally made larger than the head of connecting bolt 21. Therefore, when the axial force generated in connecting bolt 21 is transmitted to intermediate fittings 31 and 32, buffer 11 is subjected to not only compressive load but also bending moment and shear load. In addition, because buffer 11 is adjacent to gap 28, these loads can cause buffer 11 to deform and enter gap 28.

[0040] In reality, if an excessive load acts in a direction that separates one member 71 and the counterpart member 81, the buffer 11 will deform and enter the gap 28, as shown in the lower part of the figure. However, during this time, the connection between the one member 71 and the counterpart member 81 is consistently maintained, ensuring the tenacity of the connecting structure. Note that by increasing the diameter of the gap 28, the distance between the head of the connecting bolt 21 and the inner circumferential surface of the gap 28 increases, thereby accelerating the deformation of the buffer 11. Furthermore, by reducing the thickness of the buffer 11, the deformation of the buffer 11 is also promoted.

[0041] The simple shape of the buffer 11 makes it easy to adjust its dimensions, ensuring optimal toughness in a variety of connection structures, and is also cost-effective. It is necessary to ensure the strength of each part of the connection structure so that deformation caused by an excessive load is concentrated on the buffer 11. While the illustration shows the buffer 11 incorporated into both of the two intermediate metal fittings 31 and 32, it is also possible to limit it to just one of them. In this case, however, the amount of deformation will be suppressed.

[0042] Figure 4 shows a connection structure similar to that shown in Figure 1, but in this case, the width of intermediate metal fittings 33 and 34 is narrower, and a deformed steel bar is used as the embedding device 62. These intermediate metal fittings 33 and 34 are narrower than those shown in Figure 1, and as a result, the gap 28 and storage hole 47 have rectangular cross sections that extend vertically. The buffer 13 is also rectangular, with a center hole 18. When the buffer 13 is inserted into the storage hole 47, only the upper and lower ends of the buffer 13 contact the inner surface of the storage hole 47, and the inner side is adjacent to the gap 28. Therefore, when excessive axial force is applied to the connecting bolt 21, the center of the buffer 13 enters the gap 28. The cross sections of the intermediate metal fittings 33 and 34 are shown in the lower right corner of the figure.

[0043] Because the buffer 13 in this figure is rectangular rather than circular, its width is reduced, which inevitably enables the width of the intermediate fittings 33, 34 to be reduced as well. The embedding tool 62 here is made by cutting a deformed steel bar with ribs 66 formed on its side periphery to a predetermined length, and is integrated with the one member 71 and the counterpart member 81 using adhesive. Note that a female thread 68 is formed on one end surface of the embedding tool 62, into which the connecting bolt 21 is threaded, just as in Figure 1. In this way, the embedding tool 62 for attaching the intermediate fittings 33, 34 can be freely selected from a variety of conventionally used materials.

[0044] 5 shows a specific example of a connecting structure according to the present invention, in which one member 71 is an upright pillar and the counterpart member 82 is a foundation, and it is assumed that one member 71 and the counterpart member 82 are connected with an intermediate metal fitting 35 interposed between them. Therefore, one member 71 is made of various types of wood, such as laminated lumber, processed into a predetermined shape, while the counterpart member 82 is concrete poured into the ground, with its upper surface finished to a flat surface and anchor bolts 88 embedded inside, only the upper ends of which protrude outside.

[0045] The intermediate metal fitting 35 is a direct adaptation of a conventional column base metal fitting, and is box-shaped, made by welding four metal plates together. The part located at the bottom is called the bottom plate 52, the parts protruding like walls from both ends of the bottom plate 52 are called side plates 54, and the part imaginarily supported by the left and right side plates 54 is called the top plate 55. The bottom plate 52 is provided with a bottom hole 53 for inserting an anchor bolt 88. During installation, the intermediate metal fitting 35 is brought close to the counterpart member 82, the anchor bolt 88 is inserted into the bottom plate 52, and then the intermediate metal fitting 35 is placed on the counterpart member 82. Thereafter, a large washer 59 is inserted into the anchor bolt 88, and a fixing nut 58 is screwed onto the anchor bolt 88, thereby fixing the intermediate metal fitting 35 to the counterpart member 82. Note that the diameter of the bottom hole 53 is made large to take into account positional errors of the anchor bolt 88.

[0046] To attach the intermediate metal fitting 35 to the one member 71, an embedding tool 61 is embedded in the bottom surface of the one member 71. The embedding tool 61 in this figure is a general-purpose lag screw, with a spirally extending ridge 64 formed on its side periphery and a hexagonal head 65 formed on one end surface for attaching tools during installation, with a female thread 68 formed in the center of the head 65. Two pilot holes 74 are drilled in the bottom surface of the one member 71 to embed the embedding tool 61. In addition, a connecting bolt 21 is used to pull the embedding tool 61 to the intermediate metal fitting 35, and a center hole 38 is formed in the top plate 55 of the intermediate metal fitting 35 to insert the connecting bolt 21. After the connecting bolt 21 is placed inside the intermediate metal fitting 35, its tip is inserted through the center hole 38 toward the female thread 68 of the embedding tool 61.

[0047] Connecting bolt 21 is not simply inserted into bore 38; it must first be inserted into buffer 14. Buffer 14 is composed of a simple cylindrical tube portion 27 and a plate portion 26 that closes one end of tube portion 27. A loophole 18 for inserting connecting bolt 21 is provided in the center of plate portion 26, and the inside of tube portion 27 forms a gap 28. When buffer 14 is assembled, plate portion 26 is turned downward, and connecting bolt 21 is inserted from below loophole 18 until the upper end surface of tube portion 27 comes into contact with top plate 55. Therefore, after connecting bolt 21 is tightened, the head of connecting bolt 21 comes into contact with plate portion 26 of buffer 14, and connecting bolt 21 penetrates the center of gap 28. If excessive axial force is applied to connecting bolt 21, plate portion 26 will deform and enter gap 28.

[0048] Figure 6 shows the process of connecting one member 71 and the counterpart member 82 in Figure 5. As shown in the upper part of this figure, after embedding a mounting tool 61 in the bottom surface of one member 71, the one member 71 is placed on the intermediate metal fitting 35, and then a connecting bolt 21 is inserted from inside the intermediate metal fitting 35 toward the embedding tool 61. However, before this, the connecting bolt 21 must be inserted into the buffer 14. When the connecting bolt 21 threaded into the embedding tool 61 is tightened, its head comes into contact with the plate portion 26 of the buffer 14 and the cylindrical portion 27 of the buffer 14 comes into contact with the top plate 55 of the intermediate metal fitting 35, so that the one member 71 is drawn toward the intermediate metal fitting 35, and the axial force generated in the connecting bolt 21 is transmitted to the intermediate metal fitting 35 via the buffer 14.

[0049] After attaching the intermediate metal fitting 35 to the one member 71, the intermediate metal fitting 35 is placed on the counterpart member 82, then the large washer 59 is inserted into the anchor bolt 88, and finally the fixing nut 58 is screwed onto the anchor bolt 88, thereby fixing the intermediate metal fitting 35 to the counterpart member 82 and installing the one member 71 to the counterpart member 82. The installation method of the column 71 using such an intermediate metal fitting 35 is the same as the conventional method, but differs from the conventional method in that the axial force generated in the connecting bolt 21 is transmitted to the intermediate metal fitting 35 via the buffer 14.

[0050] 7 shows a cross section of one member 71 and the counterpart member 82 in FIG. 5 in a state where the connection between them is complete, and the lower part of the figure illustrates a deformed state of the buffer 14. An intermediate metal fitting 35 is sandwiched between the one member 71 and the counterpart member 82, and the one member 71 and the intermediate metal fitting 35 are integrated via the embedding tool 61 and the connecting bolt 21, and the intermediate metal fitting 35 and the counterpart member 82 are integrated via the anchor bolt 88 and the fixing nut 58. The connecting bolt 21 is inserted into the buffer 14, so that the head of the connecting bolt 21 contacts the plate portion 26 of the buffer 14, and furthermore, the upper end surface of the tubular portion 27 of the buffer 14 contacts the top plate 55 of the intermediate metal fitting 35, and the connecting bolt 21 passes through the center of the gap 28.

[0051] The axial force generated in the connecting bolt 21 is transmitted to the intermediate metal fitting 35 via the buffer 14. Therefore, when an excessive tensile load acts on this connecting structure, it is transmitted to the connecting bolt 21 via the buffer 14, increasing the axial force, and eventually, as shown in the lower part of the figure, the plate portion 26 of the buffer 14 deforms and enters the gap 28, preventing damage to the connecting bolt 21 and ensuring toughness. Note that deformation of the buffer 14 creates a gap between the one member 71 and the intermediate metal fitting 35. In addition, it is necessary to ensure the strength of each part that makes up this connecting structure so that deformation when an excessive tensile load acts is concentrated on the buffer 14.

[0052] To allow the buffer 14 to deform smoothly, the inner diameter of its cylindrical portion 27 is made larger than the head of the connecting bolt 21. Therefore, the axial force acting on the connecting bolt 21 generates not only a compressive load but also a bending moment and a shear load on the plate portion 26 of the buffer 14, inducing elastic-plastic deformation of the buffer 14. Increasing the size of the buffer 14 inevitably facilitates deformation, and reducing the thickness of the plate portion 26 also facilitates deformation. However, if the plate portion 26 deforms significantly and comes into contact with the intermediate metal fitting 35, the buffer 14 will no longer function. Therefore, the size of the gap 28 must be determined based on the load conditions, etc.

[0053] Figure 8 shows a connection structure similar to that shown in Figure 5, but in this case, two buffers 14, 15 of different diameters are attached to a single connecting bolt 21. Therefore, in this figure, only the buffers 14, 15 differ from those in Figure 5. One of the buffers 71 has an embedded device 61 embedded therein, and the intermediate hardware 35 is a column base hardware. By assembling two buffers 14, 15 in series vertically, as shown in this figure, the strength of the connection structure can be increased. However, the lower buffer 14 has a smaller diameter and contacts the head of the connecting bolt 21. Furthermore, the upper end surface of the cylindrical portion 27 of the lower buffer 14 contacts the plate portion 26 of the upper buffer 15. Furthermore, the upper end surface of the cylindrical portion 27 of the upper buffer 15 contacts the intermediate hardware 35.

[0054] Figure 9 shows a cross section of the completed connection between one member 71 and counterpart member 82 in Figure 8, with the lower part of the figure depicting the deformed state of buffers 14, 15. Two buffers 14, 15 are installed in series between the head of connecting bolt 21 and top plate 55 of intermediate metal fitting 35, and when an excessive tensile load acts on this connection structure, contact with connecting bolt 21 causes deformation of plate portion 26 of lower buffer 14. In addition, the load transmitted from buffer 14 also causes deformation of plate portion 26 of upper buffer 15. By simultaneously deforming multiple buffers 14, 15 in this way, it is possible to increase the amount of deformation for a given load.

[0055] Figure 10 shows a connecting structure similar to that shown in Figure 5, but in this case, two identical buffers 16 are attached to one connecting bolt 21. As in Figure 5, this buffer 16 is made up of a plate portion 26 and a cylindrical portion 27, but a female thread 19 is formed in the center of the plate portion 26, so that even if the buffer 16 does not come into contact with the head of the connecting bolt 21, the female thread 19 will thread into the connecting bolt 21, thereby transmitting the axial force. However, as before, the buffer 16 must come into contact with the intermediate hardware 35 in some way.

[0056] In this diagram, two buffers 16 are assembled in series with one connecting bolt 21. The lower one contacts the head of the connecting bolt 21 via a small washer 29, and the connecting bolt 21 is threaded into its internal threads 19. The upper one contacts an intermediate metal fitting 35, and the connecting bolt 21 is threaded into its internal threads 19. The two buffers 16 lined up vertically have the same shape, and their cylindrical portions 27 are aligned concentrically. Note that the threads of the connecting bolt 21 are incomplete near its head, making it impossible to thread the buffer 16 there. Therefore, a small washer 29 is inserted.

[0057] Figure 11 shows a cross section of the completed connection between one member 71 and counterpart member 82 in Figure 10, with the bottom of the figure depicting the deformed state of buffer body 16. Two buffer bodies 16 are installed in series between the head of connecting bolt 21 and top plate 55 of intermediate metal fitting 35, and when an excessive tensile load acts on this connection structure, the two buffer bodies 16 deform in approximately the same way due to the engagement between connecting bolt 21 and buffer bodies 16. In this way, when multiple buffer bodies 16 are arranged in series and all are engaged with connecting bolts 21, all buffer bodies 16 deform in approximately the same way, which improves rigidity and inevitably reduces the amount of deformation in response to a load.

[0058] The configuration shown in this figure allows for adjustment of toughness by changing the number of buffers 16 incorporated into a single connecting bolt 21, ensuring versatility while also being compatible with a variety of connecting structures. Also in Figure 8, for the buffer 15 located away from the head of the connecting bolt 21, a female thread 19 is formed in its center instead of a loophole 18, making it possible to directly transmit the axial force generated in the connecting bolt 21.

[0059] Figure 12 shows examples of the shapes of components that make up the present invention. First, the upper part of the figure shows an example of the shape of buffer 12 intended for use in the connecting structure of Figure 1, etc. In this case, buffer 12 has cross-shaped slits formed, which makes buffer 12 flexible and promotes deformation under load. The lower left part of the figure shows an example of the shape of buffer 17 used in the connecting structure of Figure 5, etc. In this case, buffer 17 is dome-shaped, and this shape improves rigidity, thereby suppressing deformation under load.

[0060] The lower right of the figure shows a connecting structure similar to that shown in Figure 5, but uses a stud bolt as the connecting bolt 22, and threads a connecting nut 24 onto its lower end to integrate the one member 71 and the intermediate metal fitting 35. The buffer 11 here is simply disk-shaped, and a cylindrical spacer 57 is combined with it to ensure a gap 28. If the buffer 11 and the spacer 57 are integrated by welding or other means, the buffer 14 shown in Figure 5 is obtained. Additionally, the upper part of the connecting bolt 22 must be integrated with the one member 71 by some means, but this means can be freely selected. Naturally, the present invention is not limited to the connecting structures shown in the previous figures; various connecting structures can be realized by freely combining the components depicted in the figures within a feasible range. [Explanation of symbols]

[0061] 11 Buffer (disk-shaped) 12. Cushion (disc-shaped with slits) 13 Buffer (rectangle) 14 Cushioning body (cylindrical) 15 Buffer body (large diameter cylinder) 16. Cushion (cylindrical with a female thread in the center) 17 Buffer body (dome-shaped) 18 Loopholes 19 Female thread 21 Connecting bolt (headed bolt) 22 Connecting bolt (stud bolt) 24 Connecting nut 26 Board part 27 Cylinder part 28 void 29 Small washer 31 Intermediary hardware (wide) 32 Intermediary hardware (wide) 33 Intermediary hardware (narrow width) 34 Intermediary hardware (narrow width) 35 Intermediary hardware (column base hardware) 38 Middle hole 42 Rod 43 Sharp part 44 Ukeobi 46 pin holes 47 Storage hole 48 through pin 52 Bottom plate 53 Bottom hole 54 Side panel 55 Top plate 57 Spacer 58 Fixing nut 59 Large washer 61 Buried tool (lag screw) 62 Buried equipment (deformed steel bars) 64 Convex strip 65 Head 66 Ribs 68 Female thread 71 One side material (column) 74 pilot hole 81 Other material (beam) 82 Other material (foundation) 84 pilot hole 85 Storage groove 86 Side Cave 88 Anchor Bolt

Claims

1. A connecting structure between adjacent one member (71) and counterpart members (81 to 82), using connecting bolts (21 to 22), intermediate metal fittings (31 to 35), and buffer bodies (11 to 17), the connecting bolts (21 and 22) are arranged so as to maintain a state in which the one member (71) and the counterpart members (81 and 82) are attracted to each other, The intermediate metal fittings (31 to 35) are disposed at the ends of the connecting bolts (21 to 22) to receive the axial force thereof, and the intermediate metal fittings (31 to 35) are provided with holes (38) into which the connecting bolts (21 to 22) are inserted. The buffer bodies (11 to 17) are disposed between the connecting bolts (21 to 22) and the intermediate metal fittings (31 to 35), and the axial force generated in the connecting bolts (21 to 22) is transmitted to the intermediate metal fittings (31 to 35) via the buffer bodies (11 to 17), and the connecting bolts (21 to 22) are inserted into the buffer bodies (11 to 17), In the buffer bodies (11 to 17), the surfaces that transmit the axial force generated in the connecting bolts (21 to 22) toward the intermediate metal fittings (31 to 35) are secured on the outer edge portions of the buffer bodies (11 to 17), When the outer edge portion comes into direct or indirect contact with the intermediate metal fittings (31 to 35), the axial force generated in the connecting bolts (21 to 22) is transmitted to the intermediate metal fittings (31 to 35), The connecting bolts (21 to 22) are inserted into the inner parts of the buffer bodies (11 to 17) that are inside the outer edge parts, and a gap (28) is formed between the inner parts and the intermediate metal fittings (31 to 35). When an excessive axial force is generated in the connecting bolts (21 to 22), the inner parts of the buffer bodies (11 to 17) deform in an out-of-plane direction and enter the gap (28) before the connecting bolts (21 to 22) deform.

2. A connecting structure between adjacent one member (71) and other member (81 to 82), using connecting bolts (21 to 22), intermediate hardware (31 to 35), and buffer bodies (11 to 17), the connecting bolts (21 and 22) are arranged so as to maintain a state in which the one member (71) and the counterpart members (81 and 82) are attracted to each other, The intermediate metal fittings (31 to 35) are disposed at the ends of the connecting bolts (21 to 22) to receive the axial force thereof, and the intermediate metal fittings (31 to 35) are provided with holes (38) into which the connecting bolts (21 to 22) are inserted. The buffer bodies (11 to 17) are disposed between the connecting bolts (21 to 22) and the intermediate metal fittings (31 to 35), and the axial force generated in the connecting bolts (21 to 22) is transmitted to the intermediate metal fittings (31 to 35) via the buffer bodies (11 to 17), and the connecting bolts (21 to 22) are inserted into the buffer bodies (11 to 17), In the buffer bodies (11 to 17), the surfaces that transmit the axial force generated in the connecting bolts (21 to 22) toward the intermediate metal fittings (31 to 35) are secured at the outer edge of the buffer bodies (11 to 17), and the inside thereof is formed as a gap (28). When excessive axial force is generated in the connecting bolts (21 to 22), the buffer bodies (11 to 17) deform and enter the gap (28) before the connecting bolts (21 to 22) deform. The buffer body (14 to 16) is composed of a hollow cylindrical portion (27) and a plate portion (26) that closes one end of the cylindrical portion (27), and the connecting bolt (21 to 22) penetrates the plate portion (26), and the inside of the cylindrical portion (27) becomes the gap (28).

3. A connecting structure between adjacent one member (71) and other member (81 to 82), using connecting bolts (21 to 22), intermediate hardware (31 to 35), and buffer bodies (11 to 17), the connecting bolts (21 and 22) are arranged so as to maintain a state in which the one member (71) and the counterpart members (81 and 82) are attracted to each other, The intermediate metal fittings (31 to 35) are disposed at the ends of the connecting bolts (21 to 22) to receive the axial force thereof, and the intermediate metal fittings (31 to 35) are provided with holes (38) into which the connecting bolts (21 to 22) are inserted. The buffer bodies (11 to 17) are disposed between the connecting bolts (21 to 22) and the intermediate metal fittings (31 to 35), and the axial force generated in the connecting bolts (21 to 22) is transmitted to the intermediate metal fittings (31 to 35) via the buffer bodies (11 to 17), and the connecting bolts (21 to 22) are inserted into the buffer bodies (11 to 17), In the buffer bodies (11 to 17), the surfaces that transmit the axial force generated in the connecting bolts (21 to 22) toward the intermediate metal fittings (31 to 35) are secured at the outer edge of the buffer bodies (11 to 17), and the inside thereof is formed as a gap (28). When excessive axial force is generated in the connecting bolts (21 to 22), the buffer bodies (11 to 17) deform and enter the gap (28) before the connecting bolts (21 to 22) deform. A connecting structure characterized in that the buffer body (16) is formed with a female thread (19) for threadably engaging with the connecting bolt (21 or 22).

4. A connecting structure as described in claim 1 or 2, characterized in that the buffer body (16) is formed with a thread (19) for screwing onto the connecting bolt (21 to 22).

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