JOINT METAL AND BUILDING STRUCTURE

The present invention relates to a joint metal used when a horizontal structural member is joined to a support material and to a building structure when a support material and a horizontal structural member are joined together using the joint metal.

Conventionally, in a wooden building, as a method for joining a wood such as a pillar and a wood such as a beam, joint metals in various shapes are used for the purposes of streamlining construction, ensuring resistance of a joint portion, and similar purpose.

As this joint metal, for example, there is a joint metal constituted in a U shape by a front plate and a pair of side plates (for example, see Patent Document 1). The front plate is secured in contact with the side surface of the pillar. The side plates project toward the beam side by folding both ends of the front plate. In this joint metal, a plurality of front holes for inserting bolts through the front plate is formed to be arranged in the up-down direction. The front plate is fastened with nuts in a state where the bolts inserted through these front holes have passed through the pillar, so as to be secured to the side surface of the pillar. Additionally, on the side plate, a plurality of pinholes is formed to be arranged in the up-down direction. In a state where the side plate has been inserted into grooves formed on the end surface of the beam, the drift pin is driven from the side hole formed on the side surface of the beam so as to couple the side plate to the beam.

However, in this joint metal, in the case where an excessive load acts on the joint portion, cracking occurs in the beam before the metal deforms. Finally, the beam fractures and then the joint portion is broken. Here, the woods have individual differences in strength due to a factor such as a water content rate. Accordingly, in the case where this joint metal is used, variation in yield resistance or similar parameter becomes large due to the fracture of the wood as a determination factor of the yield point. Therefore, a plurality of deficient portions, which is widely opened in up, down, right, and left directions, is formed in a region other than the pinholes formed on the side plate. Accordingly, when an excessive load acts on the beam, the side plate elastically deforms. The energy is absorbed by this elastic deformation so as to reduce the local load acting on the beam. This slows occurrence of cracking in the beam. This joint metal has been disclosed (for example, see Patent Document 2).

• Patent Document 1: Japanese Unexamined Patent Application Publication No. 2007-278027
• Patent Document 2: Japanese Unexamined Patent Application Publication No. 2011-214354

However, in the joint metal of Patent Document 2, since the region of the deficient portion formed on the side plate occupies the large part of the side plate, the rigidity of the entire metal is decreased. Accordingly, when a load acts on the joint portion, an elastic deformation occurs at an unnecessarily early stage. Thus, the value of the yield resistance decreases so as to reduce the variation in fracture behavior of the beam. However, a high strength performance cannot be always obtained as the entire joint portion. As illustrated in FIG. 27, in a conventional joint metal 100 formed in a U shape, in the case where a front plate 4 where front holes for insertion of bolts are formed is fastened with a bolt 6 so as to be secured to the side surface of a pillar 2 or similar member with a high torque, the front plate 4 is pulled to the bolt 6 side (arrow direction) as illustrated in FIG. 27A. Accordingly, as illustrated in FIG. 27B, a pair of side plates 5 might fall over to the inside or outside. Thus, there is a problem of interference with the grooves formed on the end surface of the beam.

The present invention has been made in view of the above-described problems, and it is an object of the present invention to provide a joint metal and a building structure that do not ruin yield resistance, initial rigidity, energy absorbing ability, and similar property of a joint portion between a support material such as a pillar and a horizontal structural member such as a beam when an excessive load acts on the joint portion and that are excellent in stability of strength as the joint portion and have high reliability. Additionally, it is an object of the present invention to provide a joint metal and a building structure that suppress falling over of a coupling plate disposed to project from a securing plate to a horizontal structural member side when the securing plate secured to a side surface of a support material is fastened with a bolt.

To achieve the above-described objects, a first joint metal according to the present invention is a joint metal for joining an end surface of a horizontal structural member to a side surface of a support material. The joint metal includes a securing plate and a coupling plate. The securing plate is to be secured to the side surface of the support material. The coupling plate is disposed to project from the securing plate toward the horizontal structural member side. The coupling plate is to be coupled in a state inserted into a groove formed over a vertical direction on the end surface of the horizontal structural member. The coupling plate includes a coupling hole and a first deficient portion. The coupling hole allows insertion of a rod-shaped coupling tool within the groove. The coupling tool is to pass through the horizontal structural member. The first deficient portion is formed by cutting out a peripheral area of the coupling hole. The first deficient portion is formed in an arc shape centered at the coupling hole.

In a second joint metal according to the present invention, the first deficient portion is formed in an arc shape centered at the coupling hole with a constant diameter.

In a third joint metal according to the present invention, a plurality of the first deficient portions are formed in arc shapes centered at the coupling holes with a same diameter. One of portions between end portions of the first deficient portions adjacent to one another in a circumferential direction is disposed to be positioned on a horizontal straight line passing through a center of the coupling hole and on a distal end side of the coupling plate with respect to the coupling hole in a horizontal direction.

In a fourth joint metal according to the present invention, the first deficient portion is formed symmetrically to a horizontal straight line passing through a center of the coupling hole.

A fifth joint metal according to the present invention is a joint metal for joining an end surface of a horizontal structural member to a side surface of a support material. The joint metal includes a securing plate and a coupling plate. The securing plate is to be secured to the side surface of the support material. The coupling plate is disposed to project from the securing plate toward the horizontal structural member side. The coupling plate is to be coupled in a state inserted into a groove formed over a vertical direction on the end surface of the horizontal structural member. The coupling plate includes a plurality of coupling holes and a second deficient portion. The coupling holes allow insertion of rod-shaped coupling tools within the groove. The coupling tools are to pass through the horizontal structural member. The second deficient portion is along a vertical straight line that passes through a center of the coupling hole. The second deficient portion is formed to be long in a vertical direction between the adjacent coupling holes.

A sixth joint metal according to the present invention is a joint metal for joining an end surface of a horizontal structural member to a side surface of a support material. The joint metal includes a securing plate and a coupling plate. The securing plate is to be secured to the side surface of the support material. The coupling plate is disposed to project from the securing plate toward the horizontal structural member side. The coupling plate is to be coupled in a state inserted into a groove formed over a vertical direction on the end surface of the horizontal structural member. The coupling plate includes a plurality of coupling holes, a third deficient portion, and a fourth deficient portion. The coupling holes allow insertion of rod-shaped coupling tools within the groove. The coupling tools are to pass through the horizontal structural member. The third deficient portion is cut out in a peripheral area of the coupling hole. The fourth deficient portion is along a vertical straight line that passes through the coupling hole. The third deficient portion is formed in an arc shape centered at the coupling hole. The fourth deficient portion is formed to be long in a vertical direction between the adjacent coupling holes.

In a seventh joint metal according to the present invention, the third deficient portion is formed in an arc shape with a constant diameter centered at the coupling hole.

In an eighth joint metal according to the present invention, a plurality of the third deficient portions are formed in arc shapes centered at the coupling holes with a same diameter. One of portions between end portions of the first deficient portions adjacent to one another in a circumferential direction is disposed to be positioned on a horizontal straight line passing through a center of the coupling hole and on a distal end side of the coupling plate with respect to the coupling hole in a horizontal direction.

In a ninth joint metal according to the present invention, the third deficient portion is formed symmetrically to a horizontal straight line passing through a center of the coupling hole.

In a tenth joint metal according to the present invention, the coupling plate includes a pin groove and a fifth deficient portion and/or a sixth deficient portion. The pin groove is formed on an upper end of the coupling plate. The fifth deficient portion is formed by cutting out in an arc shape in a peripheral area of the pin groove. The sixth deficient portion is formed by cutting out to be long in a vertical direction between the pin groove and the coupling hole adjacent to the pin groove.

An eleventh joint metal according to the present invention is a joint metal for joining an end surface of a horizontal structural member to a side surface of a support material. The joint metal includes a securing plate and a coupling plate. The securing plate is to be secured to the side surface of the support material. The coupling plate is disposed to project from the securing plate toward the horizontal structural member side. The coupling plate is to be coupled in a state inserted into a groove formed over a vertical direction on the end surface of the horizontal structural member. The coupling plate includes a coupling hole and a seventh deficient portion. The coupling hole allows insertion of a rod-shaped coupling tool within the groove. The coupling tool is to pass through the horizontal structural member. The seventh deficient portion is in communication with the coupling hole. The seventh deficient portion is formed to be long along a horizontal straight line.

In a twelfth joint metal according to the present invention, the seventh deficient portion has a vertical width smaller than a diameter of the coupling hole.

In a thirteenth joint metal according to the present invention, the securing plate includes a plurality of fixing holes for inserting fixtures. The fixing holes are formed to be aligned in a vertical direction. A securing-plate reinforcing bead is disposed. The securing-plate reinforcing bead projects from a back-side portion of the securing plate in contact with the side surface of the support material toward a projection direction of the coupling plate.

In a fourteenth joint metal according to the present invention, the securing-plate reinforcing bead is formed in a shape where a plurality of arcs communicate with one another in a vertical direction centered at the fixing holes so as to surround peripheral areas of the fixing holes.

In a fifteenth joint metal according to the present invention, a reinforcing rib is disposed on a bended portion at a boundary between the securing plate and the coupling plate.

In a sixteenth joint metal according to the present invention, the securing plate includes a plurality of fixing holes for inserting fixtures. The fixing holes are formed to be aligned in a vertical direction. A reinforcing rib is disposed on a bended portion at a boundary between the securing plate and the coupling plate.

In a seventeenth joint metal according to the present invention, the reinforcing rib is disposed in each portion between the fixing holes adjacent to one another in the vertical direction.

In an eighteenth joint metal according to the present invention, the securing plate includes a plurality of fixing holes for inserting fixtures. The fixing holes are formed to be aligned in a vertical direction. A bended-portion reinforcing bead is disposed in communication with the securing plate from the coupling plate through a bended portion at a boundary between the securing plate and the coupling plate.

In a nineteenth joint metal according to the present invention, end-portion reinforcing beads are disposed on both end portions in a width direction of the securing plate. The end-portion reinforcing bead is long in a vertical direction and projects from a back-side portion of the securing plate in contact with the side surface of the support material toward a projection direction of the coupling plate.

A building structure according to the present invention includes any one of the first to nineteenth joint metals. The joint metal joins the support material and the horizontal structural member together.

According to the first joint metal, the first deficient portion in an arc shape centered at the coupling hole is formed in the peripheral area of the coupling hole through which the rod-shaped coupling tool, which passes through the horizontal structural member, is inserted within the groove formed over the vertical direction on the end surface of the horizontal structural member. When an excessive load acts on the joint portion between the support material and the horizontal structural member, locally deforming the peripheral area of the coupling hole allows reducing the fracture of the horizontal structural member and allows controlling the deformation of the entire joint metal so as to reduce the variation in resistance of the joint portion. Additionally, this does not ruin the rigidity of the region other than the peripheral area of the coupling hole, thus maintaining relatively high yield resistance so as to improve a proof stress evaluation value.

According to the second joint metal, the first deficient portion in the arc shape centered at the coupling hole with the constant diameter is formed. This allows more efficiently causing local deformation of the peripheral area of the coupling hole when an excessive load acts on the joint portion between the support material and the horizontal structural member.

According to the third joint metal, the plurality of the first deficient portions are formed in arc shapes centered at the coupling hole with the same diameter. One of the portions between the end portions of the first deficient portions adjacent to one another in the circumferential direction is disposed to be positioned on the horizontal straight line passing through the center of the coupling hole and on the distal end side of the coupling plate with respect to the coupling hole in the horizontal direction. This allows improving the resistance against a tension load that acts on the horizontal structural member toward the horizontal direction side of the coupling plate.

According to the fourth joint metal, the first deficient portion is formed symmetrically to the horizontal straight line passing through the center of the coupling hole. Therefore, in either case where an excessive load acts on the horizontal structural member upward or downward in the vertical direction, the peripheral area of the coupling hole efficiently deforms. This allows reducing the fracture of the horizontal structural member.

According to the fifth joint metal, the coupling plate includes the coupling hole and the second deficient portion. The coupling hole allows insertion the rod-shaped coupling tool, which passes through the horizontal structural member, within the groove formed over the vertical direction on the end surface of the horizontal structural member. The second deficient portion is along the straight line that passes through the center of the coupling hole, and is formed to be long in the vertical direction between the adjacent coupling holes. Therefore, when an excessive load acts on the joint portion between the support material and the horizontal structural member, the peripheral area of the coupling hole deforms. This allows reducing the fracture of the horizontal structural member. Additionally, increasing the deficient amount in the vertical direction including the coupling hole, which receives the stress from the coupling tool, allows controlling the deformation of the joint metal so as to reduce the variation in resistance on the joint portion. Additionally, this allows improving the resistance against a tension load that acts on the horizontal structural member toward the horizontal direction side of the coupling plate.

According to the sixth joint metal, the third deficient portion in the arc shape centered at the coupling hole is formed in the peripheral area of the coupling hole. Therefore, when an excessive load acts on the joint portion between the support material and the horizontal structural member, the peripheral area of the coupling hole locally deforms. This allows reducing the fracture of the horizontal structural member, and allows controlling the deformation of the entire joint metal so as to reduce the variation in resistance of the joint portion. Additionally, the fourth deficient portion is along the straight line that passes through the center of the coupling hole, and is formed to be long in the vertical direction between the adjacent coupling holes. Therefore, increasing the deficient amount in the vertical direction including the coupling hole, which receives the stress from the coupling tool, allows controlling the deformation of the joint metal so as to reduce the variation in resistance of the joint portion.

According to the seventh joint metal, the third deficient portion in the arc shape centered at the coupling hole is formed in the peripheral area of the coupling hole. This allows more efficiently causing local deformation of the peripheral area of the coupling hole when an excessive load acts on the joint portion between the support material and the horizontal structural member.

According to the eighth joint metal, the plurality of the third deficient portions are formed in the arc shapes centered at the coupling hole with the same diameter. One of the portions between the end portions of the deficient portions adjacent to one another in the circumferential direction is disposed to be positioned on the horizontal straight line passing through the center of the coupling hole and on the distal end side of the coupling plate with respect to the coupling hole in the horizontal direction. This allows improving the resistance against a tension load that acts on the horizontal structural member toward the horizontal direction side of the coupling plate.

According to the ninth joint metal, the third deficient portion is formed symmetrically to the horizontal straight line passing through the center of the coupling hole. Therefore, in either case where an excessive load acts on the horizontal structural member upward or downward in the vertical direction, the peripheral area of the coupling hole efficiently deforms. This allows reducing the fracture of the horizontal structural member.

According to the tenth joint metal, the coupling plate includes the pin groove and the fifth deficient portion and/or the sixth deficient portion. The pin groove is formed on the upper end of the coupling plate. The fifth deficient portion is formed by cutting out in the arc shape in the peripheral area of the pin groove. The sixth deficient portion is formed by cutting out to be long in the vertical direction between the pin groove and the coupling hole adjacent to the pin groove. Therefore, when an excessive load acts on the joint portion between the support material and the horizontal structural member, the peripheral area of the pin groove locally deforms. This allows reducing the fracture of the horizontal structural member and allows controlling the deformation of the entire joint metal so as to reduce the variation in resistance of the joint portion.

According to the eleventh joint metal, the coupling plate includes the coupling hole and the seventh deficient portion. The coupling hole allows insertion of the rod-shaped coupling tool, which passes through the horizontal structural member, within the groove formed over the vertical direction on the end surface of the horizontal structural member. The seventh deficient portion is in communication with the coupling hole, and is formed to be long along the horizontal straight line. Therefore, when an excessive load acts on the joint portion between the support material and the horizontal structural member, the peripheral area of the coupling hole deforms. This allows reducing the fracture of the horizontal structural member. Additionally, the deficient portion is formed to be long in the horizontal direction of the coupling hole. This allows inducing stable lateral displacement deformation of the joint metal so as to reduce the variation in resistance of the joint portion. Additionally, this does not ruin the rigidity of the region other than the peripheral area of the coupling hole, thus maintaining relatively high yield resistance so as to improve the proof stress evaluation value.

According to the twelfth joint metal, the seventh deficient portion has the vertical width smaller than the diameter of the coupling hole. This allows preventing movement of the coupling tool from the coupling hole in the horizontal direction.

According to the thirteenth joint metal, the securing-plate reinforcing bead is disposed. The securing-plate reinforcing bead projects from the back-side portion of the securing plate in contact with the side surface of the support material toward the projection direction of the coupling plate. This allows improving the rigidity of the securing plate, so as to suppress falling over of the coupling plate when the securing plate is fastened with a fixture such as a bolt due to pulling the securing plate to the bolt side. Additionally, as described above, the rigidity of the securing plate can be improved so as to suppress falling over of the coupling plate. This allows thinning the plate thicknesses of the securing plate and the coupling plate while ensuring high strength.

According to the fourteenth joint metal, the securing-plate reinforcing bead is formed in the shape where the plurality of the arcs communicate with one another in the vertical direction centered at the fixing holes so as to surround the peripheral areas of the fixing holes. This allows efficiently improving the strength around the fixing holes of the securing plate, thus more reliably suppressing falling over of the coupling plate when the securing plate is fastened with a fixture such as a bolt.

According to the fifteenth joint metal, the reinforcing rib is further disposed on the bended portion at the boundary between the securing plate and the coupling plate. This allows improving the strength of the bended portion, thus suppressing falling over of the coupling plate when the securing plate is fastened with a fixture such as a bolt.

According to the sixteenth joint metal, the reinforcing rib is disposed on the bended portion at the boundary between the securing plate and the coupling plate. This allows improving the strength of the bended portion, thus suppressing falling over of the coupling plate when the securing plate is fastened with a fixture such as a bolt. Additionally, as described above, the strength of the bended portion can be improved so as to suppress falling over of the coupling plate. This allows thinning the plate thicknesses of the securing plate and the coupling plate while ensuring high strength.

According to the seventeenth joint metal, the reinforcing rib is disposed in each portion between the fixing holes adjacent to one another in the vertical direction. This allows ensuring high strength in any position of the bended portion in the vertical direction, thus more reliably suppressing falling over of the coupling plate when the securing plate is fastened with a fixture such as a bolt.

According to the eighteenth joint metal, the bended-portion reinforcing bead is disposed in communication with the securing plate from the coupling plate through the bended portion at the boundary between the securing plate and the coupling plate. This allows improving the strength of the bended portion, thus suppressing falling over of the coupling plate when the securing plate is fastened with a fixture such as a bolt. Additionally, as described above, the strength of the bended portion can be improved so as to suppress falling over of the coupling plate. This allows thinning the plate thicknesses of the securing plate and the coupling plate while ensuring high strength.

According to the nineteenth joint metal, the end-portion reinforcing beads are further disposed on both the end portions in the width direction of the securing plate. The end-portion reinforcing bead is long in the vertical direction, and projects from the back-side portion of the securing plate in contact with the side surface of the support material toward the projection direction of the coupling plate. This allows improving the strength of both the ends in the width direction of the securing plate, thus more reliably suppressing falling over of the coupling plate when the securing plate is fastened with a fixture such as a bolt.

With the building structure according to the present invention, when an excessive load acts on the joint portion between the support material and the horizontal structural member, the peripheral area of the coupling hole of the coupling plate to be coupled to the horizontal structural member deforms. This allows reducing the fracture of the horizontal structural member, thus reducing the variation in resistance. Additionally, this does not ruin the rigidity of the region other than the peripheral area of the coupling hole, thus maintaining relatively high yield resistance so as to improve the proof stress evaluation value. Additionally, this allows suppressing falling over of the coupling plate when the securing plate is fastened with a fixture such as a bolt, so as to thin the plate thicknesses of the securing plate and the coupling plate while ensuring high strength.

The following describes embodiments of a joint metal according to the present invention with reference to the drawings. As illustrated in FIGS. 1A and 1B and FIG. 2, a joint metal 1 according to a first embodiment of the present invention is for joining the end surface of a horizontal structural member 3 such as a beam to the side surface of a support material 2 such as a pillar in a wooden building structure. The joint metal 1 is constituted to have a U shape in top view by a securing plate 4 and a pair of coupling plates 5. The securing plate 4 is secured to the side surface of the support material 2. The coupling plates 5 project from both ends of the securing plate 4 approximately in the horizontal direction on the horizontal structural member 3 side. This joint metal 1 is used, for example, as a joist hanger for joining the end surface of the beam to the side surface of the pillar. Here, the support material 2 is not limited to the pillar and only needs to be a structural member for supporting the horizontal structural member 3. For example, the support material 2 may be a beam or similar member that is different from a girth or the horizontal structural member 3. Also, the horizontal structural member 3 is not limited to the beam and only needs to be a structural member where the end surface is joined to the support material 2 in the approximately horizontal direction. For example, the horizontal structural member 3 may be a girder, a girth, or similar member.

The securing plate 4 is secured to the side surface of the support material 2 in contact with each other. As illustrated in FIG. 2, in the securing plate 4, a plurality of fixing holes 41 for allowing insertion of fixtures such as the bolts 6 is formed to be aligned in the longitudinal direction. On the side surface of the support material 2, bolt holes 21 and counter sink holes 22 are formed. The bolt hole 21 is for insertion of the bolt 6 for securing the securing plate 4. The counter sink hole 22 is for housing a nut 7 to be threadably mounted on the bolt 6 inserted through the bolt hole 21. When the securing plate 4 is secured to the side surface of the support material 2, the bolts 6 are inserted from the fixing holes 41 in a state where a back-side portion 42 of the securing plate 4 is in contact with the side surface of the support material 2 such that the fixing holes 41 correspond to the respective bolt holes 21. Then, in a state where the bolt 6 is inserted until the distal end of the bolt 6 has reached the counter sink hole 22, the nut 7 is threadably mounted so as to secure the securing plate 4 to the side surface of the support material 2. Here, the method for securing the securing plate 41 is not limited to this method. Instead of the bolt 6, nails or similar tool may be driven to the side surface of the support material 2 from the fixing hole 41 for securing the securing plate.

The coupling plates 5 are coupled to the horizontal structural member 3. As illustrated in FIGS. 1A and 1B and FIG. 2, the coupling plates 5 are folded at approximately a right angle from both the ends of the securing plate 4 and are extended to project toward the horizontal structural member 3 side. This coupling plate 5 includes a pin groove 51, a sixth deficient portion 531, a plurality of coupling holes 52, and a plurality of second deficient portions 532 and 533. The pin groove 51 is a cutout approximately in a U shape. The sixth deficient portion 531 is formed by cutting out the peripheral area on the lower side of the pin groove 51. The coupling hole 52 allows insertion of the drift pin 8 to be coupled to the horizontal structural member 3. The second deficient portions 532 and 533 are formed by cutting out the peripheral area of the coupling hole 52.

The pin groove 51 is formed on the upper end of the coupling plate 5 so as to receive the drift pin 8. The plurality of coupling holes 52 is formed to be aligned in the vertical direction below the pin groove 51. The sixth deficient portion 531 and the plurality of second deficient portions 532 and 533 are formed in vertically long slit shapes while passing through a straight line A, on which the pin groove 51 and the plurality of coupling holes 52 are arranged, in the vertical direction. On the end surface of the horizontal structural member 3, grooves 31 for allowing insertion of the pair of the respective coupling plates 5 are formed over the longitudinal direction (vertical direction). On the side surface of the horizontal structural member 3, a plurality of pinholes 32 into which the drift pin 8 driven is formed to be aligned in the longitudinal direction. When this horizontal structural member 3 and the coupling plates 5 are coupled to each other, firstly, the horizontal structural member 3 is moved so as to be positioned on the upper side of the joint metal 1 where the securing plate 4 is secured to the side surface of the support material 2. At this time, the drift pin 8 is preliminarily driven to the uppermost pinhole 32 of the horizontal structural member 3. Subsequently, the horizontal structural member 3 is gradually moved down until the drift pin 8 that has been driven is brought into contact with the pin groove 51. In a state where the pair of coupling plates 5 is inserted into the grooves 31 of the horizontal structural member 3, the drift pins 8 are driven to the remaining pinholes 32 so as to couple the horizontal structural member 3 and the coupling plate 5 together.

The sixth deficient portion 531 and the second deficient portions 532 and 533 formed in the coupling plate 5 are for reducing the fracture of the horizontal structural member by facilitating deformation of the peripheral area of the pin groove 51 and the coupling hole 52 when an excessive load acts on the joint portion between the support material 2 and the horizontal structural member 3 in a state where the coupling plate 5 and the horizontal structural member 3 are coupled together. As illustrated in FIGS. 1A and 1B, the sixth deficient portion 531 is formed to be long in the vertical direction between the pin groove 51 and the second deficient portion 532, which is formed adjacent to the pin groove 51 in the vertical direction. The second deficient portion 532 is formed in the position at a predetermined distance from the respective coupling holes 52, so as to be positioned between the coupling holes 52 adjacent to each other in the vertical direction. This second deficient portion 532 is formed to be long along the vertical straight line A passing through the centers of the respective coupling holes 52. As illustrated in FIGS. 1A and 1B, the second deficient portion 532 is formed to have a width narrower than a diameter Φ of the coupling hole 51, and is disposed in the position at a predetermined distance W from the securing plate 4.

As illustrated in FIG. 1B, this predetermined distance W is the distance from the base end of the coupling plate 5 up to the base end side of the sixth deficient portion 531 and the second deficient portions 532 and 533. This distance W can be changed corresponding to the position of the coupling hole 52 or similar parameter. However, the coupling hole 52, the sixth deficient portion 531, and the respective second deficient portions 532 and 533 are preferred to be disposed on the distal end side with respect to the center of the width W1 in the horizontal direction of the coupling plate 5. This allows improving the rigidity of the region other than the peripheral area of the coupling hole 52. Here, the securing plate 4 side of the coupling plate 5 is defined as the base end side while the opening side of the coupling plate 5 is defined as the distal end side. Additionally, the longitudinal lengths of the sixth deficient portion 531 and the second deficient portions 532 and 533 are changed corresponding to the position of the pin groove 51 and the longitudinal distance between the coupling holes 52. In the joint metal 1 according to this embodiment, a length L1 of the sixth deficient portion 531, which is disposed between the pin groove 51 and the uppermost coupling hole 52, and the second deficient portion 533, which is disposed on the lower side of the lowermost coupling hole 52, are formed to be shorter than the second deficient portions 532 disposed between the coupling holes 52.

The following describes a joint metal 1a according to a second embodiment of the present invention with reference to FIG. 3 and FIG. 4. In this joint metal 1a, mainly, the sixth deficient portion 531 and the second deficient portions 532 and 533 are changed in shape in the joint metal 1 according to the first embodiment. For the configuration similar to that of the joint metal 1 or similar configuration, like reference numerals designate corresponding or identical elements, and therefore such elements will not be further elaborated here.

In the joint metal 1a, three first deficient portions 54 are formed at equal spaces in the circumferential direction. The first deficient portions 54 are arc-shaped elongated holes having the same diameter centered at the coupling hole 52 in the peripheral area of the coupling hole 52. Additionally, two arc-shaped fifth deficient portions 55 are formed in the peripheral area of the lower side of the pin groove 51. The width perpendicular to the circumferential direction of the first deficient portion 54 and the fifth deficient portion 55 is formed to be equal to or less than half of the diameter of the coupling hole 52. Regarding the length of the arc, the first deficient portion 54 is formed to be longer than the fifth deficient portion 55. Accordingly, in the joint metal 1a, the first deficient portion 54 and the fifth deficient portion 55 are disposed only at the periphery of the coupling hole 52 and the pin groove 51. This allows efficiently deforming the peripheral area of the coupling hole 52 and the pin groove 51 when an excessive load acts on the joint portion between the support material 2 and the horizontal structural member 3 in a state where the coupling plates 5a and the horizontal structural member 3 are coupled together. Thus, the fracture of the horizontal structural member 3 can be reduced.

As illustrated by drawing diagonal lines in FIG. 4, the first deficient portion 54 adjacent to one another in the circumferential direction are coupled to one another by respective coupling portions 56. This coupling portion 56 is a portion positioned between the end portions of the adjacent first deficient portions 54. As illustrated in FIG. 3 and FIG. 4, in the case where three first deficient portions 54 are formed, the first deficient portions 54 are disposed in three positions in the peripheral area of the coupling hole 52. In the joint metal 1a, one of the coupling portions 56 is disposed to be on a virtual line B, which passes through the center of the coupling hole 52 and extends in the horizontal direction, and to be positioned on the distal end side of the coupling plate 5a with respect to the coupling hole 52. This allows improving the resistance against the tension load acting on the horizontal direction side of the coupling plate 5a with respect to the horizontal structural member 3 in a state where this coupling plate 5a and the horizontal structural member 3 are coupled together. Additionally, the first deficient portion 54 is formed symmetrically to the straight line B. Accordingly, when an excessive load acts on the horizontal structural member 3 in any direction of the upper and lower directions in the vertical direction, the peripheral area of the coupling hole efficiently deforms. This allows reducing the fracture of the horizontal structural member 3. Here, similarly to the second deficient portion 532, this first deficient portion 54 is preferred to be disposed on the distal end side with respect to the center of the width in the horizontal direction of the coupling plate 5a in order to keep a predetermined rigidity.

In the joint metal 1a illustrated in FIG. 5, two arc-shaped first deficient portions 54a are formed in the peripheral area of the coupling hole 52. This first deficient portion 54a is formed to have the same width as that of the first deficient portion 54 illustrated in FIG. 3 while having a longer length of the arc. Regarding this first deficient portion 54a, similarly to the first deficient portion 54, the first deficient portions 54a adjacent to each other in the circumferential direction are coupled together by respective coupling portions 56. One of the coupling portions 56 is disposed to be on the virtual line B, which passes through the center of the coupling hole 52 and extends in the horizontal direction, and to be positioned on the distal end side of the coupling plate 5a with respect to the coupling hole 52.

In a first deficient portion 54b of the joint metal 1a illustrated in FIG. 6, the width perpendicular to the circumferential direction is about twice as wide as that of the first deficient portion 54 illustrated in FIG. 4. Like this first deficient portion 54a, expanding the lost region in the peripheral area of the coupling hole 52 allows the peripheral area of the coupling hole 52 to efficiently deform when an excessive load acts on the horizontal structural member 3 in a state where the coupling plate 5a and the horizontal structural member 3 are coupled together. A first deficient portion 54c of the joint metal 1a illustrated in FIG. 7 is formed to have the same width as that of the first deficient portion 54b illustrated in FIG. 5 while having a longer length of the arc.

The following describes a joint metal 1b according to a third embodiment of the present invention with reference to FIG. 8. In this joint metal 1b, third deficient portions 57 and fourth deficient portions 58 in mutually different shapes are formed on a coupling plate 5b. For the configuration similar to those of the joint metals 1 and 1a or similar configuration, like reference numerals designate corresponding or identical elements, and therefore such elements will not be further elaborated here.

As illustrated in FIG. 8, the coupling plate 5b of the joint metal 1b has the third deficient portions 57 and fourth deficient portions 581 and 582. The third deficient portion 57 has a shape similar to that of the arc-shaped first deficient portion 54 formed on the coupling plate 5a of the joint metal 1a illustrated in FIG. 3. The fourth deficient portions 581 and 582 have respective shapes similar to those of the second deficient portions 532 and 533, which have slit shapes long in the vertical direction and are formed on the coupling plate 5 of the joint metal 1 illustrated in FIGS. 1A and 1B and FIG. 2. As illustrated in FIG. 8, the respective third deficient portion 57 and fourth deficient portion 58 only need to be formed in the peripheral area of the coupling hole 52 and between the coupling holes 52 adjacent to each other in the vertical direction, corresponding to a required resistance and similar parameter.

The following describes a joint metal 1c according to a fourth embodiment of the present invention with reference to FIG. 9. In this joint metal 1c, a seventh deficient portion 59 in a horizontally long slit shape is formed in communication with the coupling hole 52. For the configuration similar to that of the joint metal 1 or similar configuration, like reference numerals designate corresponding or identical elements, and therefore such elements will not be further elaborated here.

A coupling plate 5c of the joint metal 1c has the seventh deficient portion 59 cut out in communication with the coupling hole 52. This seventh deficient portion 59 is formed to be long along a horizontal straight line C passing through the coupling hole 52. The width in the vertical direction of this seventh deficient portion 59 is formed to be smaller than the diameter of the coupling hole 52, and is formed from the coupling hole 52 toward respective both sides of the base end side and the distal end side of the coupling plate 5c. A length W3 of a seventh deficient portion 59a is formed to be longer than a length W4 of a seventh deficient portion 59b. The length W3 is formed to be elongated toward the base end side. The length W4 is formed to be elongated toward the distal end side. In this joint metal 1c where the seventh deficient portions 59 are formed on the coupling plate 5c, when an excessive load acts on the joint portion between the support material 2 and the horizontal structural member 3 in a state where the coupling plate 5c and the horizontal structural member 3 are coupled together, the peripheral area of the coupling hole 52 can be efficiently deformed. This allows reducing the fracture of the horizontal structural member 3. Additionally, this allows improving the rigidity of the region other than the peripheral area of the coupling hole 52. Here, while in this embodiment deficient portions are not formed in the peripheral area on the lower side of the pin groove 51, the sixth deficient portion 531 in the vertically elongated slit shape as illustrated in FIGS. 1A and 1B or the fifth deficient portion 55 in the arc shape as illustrated in FIG. 3 may be formed.

The following describes proof stress evaluation tests using the joint metals 1, 1a, and 1c according to the present invention. The testing method and the shape of the specimen are compliant with the description in page 583 of “Allowable stress design for houses using timber framework method (2008 edition)” (hereinafter referred to as Document). The test employs a specimen in a structure where one horizontal structural member is supported by two support materials. For the joint portions in two positions where the horizontal structural member and the support material are to be joined together, the same joint metal is used. In the test, a pressure plate made of steel is placed on the top surface of the horizontal structural member. When the load acts on the center of the pressure plate, displacement of the horizontal structural member is measured. Then, based on the graph showing the relationship between the measured displacement and the load, a proof stress evaluation value is calculated. Displacement meters are disposed four positions in total on the near side and the far side on the bottom surface near the respective end portions of the horizontal structural member, so as to calculate the average of the respective measured values as a displacement amount. For the test, joint metals in shapes described in the following working examples 1 to 3 and comparative examples 1 and 2 were used. During the test, respective three specimens are used to calculate the average. Here, the respective joint metals are different only in shape of the deficient portion. The joint metals are otherwise similar to one another.

The working example 1 employs the joint metal 1 illustrated in FIGS. 1A and 1B where the sixth deficient portion 531 and the second deficient portions 532 and 533 in the vertically elongated slit shapes are formed on the coupling plate 5. In this joint metal 1, a height H is 266 mm, a width W1 is 90 mm, a diameter Φ of the coupling hole 52 is 12.5 mm, and a distance W2 from the base end of the coupling plate 5 up to the center of the coupling hole 52 is 65 mm. For these values, the same applies to the other working examples 2 and 3 and the comparative examples 1 and 2. For the respective sixth deficient portion 531 and second deficient portions 532 and 533, the length L1 in the longitudinal direction of the sixth deficient portion 531 is 31 mm, a length L2 in the longitudinal direction of the second deficient portion 532 is 36 mm, a length L3 in the longitudinal direction of the second deficient portion 533 is 11 mm, and the widths of the sixth deficient portion 531 and the second deficient portions 532 and 533 are all 6 mm.

The working example 2 employs the joint metal 1a where the first deficient portions 54 and the fifth deficient portions 55 in the arc shapes are formed on the coupling plate 5a as illustrated in FIG. 3. As illustrated in FIG. 4, in the first deficient portion 54 and the fifth deficient portion 55 of this joint metal 1a, the curvature radius of the outer peripheral portion in the arc shape is 16.25 mm, the curvature radius of the inner peripheral portion is 11.25 mm, and a distance L4 between the first deficient portions 54 is 6 mm. Similarly, the distance between the fifth deficient portions 55 is also 6 mm.

The working example 3 employs the joint metal 1c where the seventh deficient portions 59 in the horizontally long slit shapes are formed in communication with the coupling hole 52 as illustrated in FIG. 9. For the respective seventh deficient portions 59a and 59b of this joint metal 1c, the length W3 in the lateral direction of the seventh deficient portion 59a is 26.65 mm, the length W4 in the lateral direction of the seventh deficient portion 59b is 6.75 mm, and the widths in the vertical direction of the seventh deficient portions 59a and 59b are 6.0 mm.

The comparative example 1 employs a conventional joint metal 100a where the deficient portions are not formed on a coupling plate 101a as illustrated in FIG. 10A.

As illustrated in FIG. 10B, the comparative example 2 employs a joint metal 100b where deficient portions 102b widely opened in up, down, right, and left directions are formed on a coupling plate 101b. For the deficient portion 102b of this joint metal 100b, a length L5 in the longitudinal direction of the uppermost deficient portion 102b is 26 mm and a length L6 in in the longitudinal direction of the other deficient portions 102b is 46 mm. Additionally, a length W5 in the lateral direction of the deficient portion 102b is 46 mm.

Table 1 below shows the result of the proof stress evaluation tests of the working examples 1 to 3 and the comparative examples 1 and 2. Here, Py (kN) shown in Table 1 shows yield resistance, and ⅔Pmax (kN) is obtained by multiplying the maximum load (Pmax) by ⅔. These values can be calculated from the graph illustrating the relationship between the measured displacement and the load using the method described in pages 571 and 572 of Document. The dispersion coefficient is calculated as a dispersion coefficient=1−a variation coefficient CV×k in compliance with the description in page 586 of Document. Note that k is set to a value of 3.152 corresponding to three as the number of specimens here. Table 1 shows Py (kN) and ⅔Pmax (kN) of the average values of three specimens when the tests were performed under the respective conditions of the working examples 1 to 3 and the comparative examples 1 and 2. The respective evaluation values shown on the last lines of these Py and ⅔Pmax are calculated with the method (calculating the dispersion coefficient×the average value) described in page 586 of Document. Additionally, an initial rigidity K (kN/mm) shown in Table 1 is calculated in compliance with the description in page 572 of Document while an energy E (kN·mm) is considered as the area of a perfect elasto-plastic model in page 572 of Document. Additionally, an initial crack occurrence displacement D (mm) denotes a displacement for test evaluation when occurrence of a crack is seen in the position of the drift pin. FIGS. 11 to 15 are graphs illustrating the respective relationships between a deformation D (mm) and a load P (kN) in the working examples 1 to 3 and the comparative examples 1 and 2.

As illustrated in Table 1, when the working examples 1 to 3 are compared with the comparative example 1, in the yield resistance Py, the average values keep values equivalent to that of the comparative example 1 while the dispersion coefficients have been considerably improved in all of the working examples 1 to 3. Accordingly, the proof stress evaluation values have been obviously improved. Additionally, in ⅔Pmax, the average values keep values equivalent to that of the comparative example 1 while the dispersion coefficients have been considerably improved in all of the working examples 1 to 3. Accordingly, the proof stress evaluation values have been obviously improved. In the initial rigidity and the energy, there was no noticeable reduction in the respective average values in any of the working examples 1 to 3 compared with the comparative example 1.

When the working examples 1 to 3 are compared with the comparative example 2, in the yield resistance Py, there is no reduction in the average value like the comparative example 2 in any of the working examples 1 to 3. The dispersion coefficients of the working examples 1 to 3 have not improved as much as that of the comparative example 2 have, but has been improved. Accordingly, the proof stress evaluation values have been improved equally or more than the comparative example 2 with respect to the comparative example 1. Additionally, in ⅔Pmax, there is no reduction in the average value like the comparative example 2 in any of the working examples 1 to 3. The dispersion coefficients of the working examples 1 to 3 have been improved equally or more than that of the comparative example 2. Accordingly, the proof stress evaluation values have been obviously improved. In the initial rigidity and the energy, there was no considerable reduction in the average value like the comparative example 2 in any of the working examples 1 to 3. The initial rigidity and the energy were equivalent to those of the comparative example 1.

In this embodiment, the description has been given of the joint metals 1 to 1c that have the U shapes in top view and include the pairs of coupling plates 5 to 5c, the coupling plate is not necessarily limited to the pairs of the coupling plates 5a to 5c. The present invention is applicable to a joint metal that has a T shape in top view and includes only one of the coupling plates 5 to 5c.

The following describes embodiments where reinforcement is performed to suppress falling over of the coupling plates 5 as illustrated in FIGS. 27A and 27B when the securing plate 4 is fastened with a fixture such as a bolt with reference to FIGS. 16A and 16B to FIG. 26. For the configuration similar to that of the joint metal 1 or similar configuration, like reference numerals designate corresponding or identical elements, and therefore such elements will not be further elaborated here.

As illustrated in FIGS. 16A and 16B to FIG. 18, a joint metal 1d according to the fifth embodiment of the present invention is folded at approximately a right angle from both the ends of the securing plate 4. In the joint metal 1d, the pair of coupling plates 5 is disposed approximately in the horizontal direction. The joint metal 1d is constituted to have a U shape in top view. For the joint metal 1d, similarly to the joint metal 1 according to the first embodiment, on the securing plate 4, a plurality of fixing holes 41 for allowing insertion of fixtures (not illustrated) such as bolts is formed to be aligned in the longitudinal direction. On the coupling plate 5, the pin groove 51, the coupling holes 52, the sixth deficient portion 531, and the plurality of second deficient portions 532 and 533 are formed. The pin groove 51 is a cutout approximately in a U shape. The coupling holes 52 are disposed to be aligned in the vertical direction below the pin groove 51. The sixth deficient portion 531 and the second deficient portions 532 and 533 have vertically long slit shapes so as to pass through a vertical straight line A on which the pin groove 51 and the plurality of coupling holes 52 are arranged.

In this joint metal 1d, as illustrated in FIGS. 16A and 16B to FIG. 18, reinforcing ribs 10 are disposed on bended portions 9 at the boundaries between the securing plate 4 and the coupling plates 5. As illustrated in FIGS. 16A and 16B and FIG. 17, the respective reinforcing ribs 10 are disposed to be positioned between the fixing holes 41 adjacent to one another in the vertical direction.

The reinforcing rib 10 is formed by, for example, press work or similar work so as to project inwardly in an approximately triangular shape in top view as illustrated in FIG. 18. Accordingly, as illustrated in FIG. 16B, in the case where the joint metal 1d is viewed from outside, depressed portions in approximately triangular shapes in plan view are formed on the outer surface on the base end side of the coupling plate 5. Similarly, as illustrated in FIG. 17, depressed portions in approximately triangular shapes in plan view are formed on the back-side portion 42 of the securing plate 4. Thus, in the joint metal 1d, disposing the reinforcing ribs 10 on the bended portions 9 allows improving the strength of the bended portions 9. Accordingly, when the securing plate 4 is fastened with fixtures such as bolts at a high torque, this allows suppressing falling over of the pair of coupling plates 5 as illustrated in FIGS. 27A and 27B.

Here, in this embodiment, the description has been given of the example where the reinforcing ribs 10 are disposed in the joint metal where the sixth deficient portion 531, which is formed by cutting out the peripheral area on the lower side of the pin groove 51, and the plurality of second deficient portions 532 and 533, which are formed by cutting out the peripheral area of the coupling hole 52, are formed on the coupling plate 5 similarly to the joint metal 1 according to the first embodiment illustrated in FIGS. 1A and 1B. However, the structure of the coupling plate 5 is not limited to this. The reinforcing rib is applicable to the joint metals 1a to 1c having the other coupling plates 5a to 5c illustrated in FIG. 3 to FIG. 9. The same applies to other embodiments describe later.

The following describes a joint metal 1e according to a sixth embodiment of the present invention with reference to FIG. 19 and FIG. 20. As illustrated in FIG. 19 and FIG. 20, this joint metal 1e includes securing-plate reinforcing beads 11 disposed on the securing plate 4.

As illustrated in FIG. 19 and FIG. 20, the securing-plate reinforcing beads 11 are disposed on both lateral sides of the fixing holes 41, and are formed in the shape where a plurality of arcs centered at the fixing holes 41 communicate with one another in the vertical direction so as to surround the peripheral area of the fixing holes 41. This securing-plate reinforcing bead 11 is formed by, for example, press work or similar work so as to project from the back-side portion 42 of the securing plate 4 toward the inside (in the projection direction of the coupling plate 4) as illustrated in FIG. 20. Accordingly, as illustrated in FIG. 19, in the case where the joint metal 1e is viewed from the outside, depressed portions in the shapes where a plurality of arcs centered at the fixing holes 41 are formed in the back-side portion 42 of the securing plate 4. Thus, the joint metal 1e includes the securing-plate reinforcing beads 11, which project from the back-side portion 42 of the securing plate 4 in contact with the side surface of the support material 2 toward the projection direction of the coupling plate 5. This allows improving the rigidity of the securing plate 4, and allows suppressing falling over of the pair of coupling plates 5 when the securing plate 4 is fastened with fixtures such as bolts.

In a joint metal 1f according to a seventh embodiment of the present invention illustrated in FIG. 21, the reinforcing ribs 10 of the joint metal 1d according to the fifth embodiment are further disposed in the joint metal where the securing-plate reinforcing beads 11 are disposed on the securing plate 4 like the joint metal 1e according to the sixth embodiment. In the joint metal 1f, as illustrated in FIG. 21, the reinforcing ribs 11 are formed on the bended portions 9 so as not to interfere with the securing-plate reinforcing beads 11. Thus, the securing-plate reinforcing beads 11 and the reinforcing ribs 10 may be combined together. This allows improving the rigidity of the securing plate 4 and improving the strength of the bended portions 9.

The following describes a joint metal 1g according to an eighth embodiment of the present invention with reference to FIG. 22 to FIG. 24. As illustrated in FIG. 22 to FIG. 24, the joint metal 1g includes bended-portion reinforcing beads 12, which communicate with the securing plate 4 from the coupling plates 5 through the bended portions 9 at the boundaries between the securing plate 4 and the coupling plates 5.

As illustrated in FIG. 22, the respective bended-portion reinforcing beads 12 are disposed to be positioned between the fixing holes 41 adjacent to one another in the vertical direction. As illustrated in FIG. 24, the bended-portion reinforcing bead 12 is formed by, for example, press work or similar work so as to project inwardly, and is formed in approximately an L shape in top view. As illustrated in FIG. 22 and FIG. 23, this bended-portion reinforcing bead 12 is formed, on the securing plate 4 side, to have a width L8 and to extend form the bended portion 9 in the straight line by a predetermined distance W8 in the horizontal direction. On the coupling plate 5 side, the bended-portion reinforcing bead 12 is formed to have the width L8 similarly to the securing plate 4 side and to extend from the base end (the bended portion 9) of the coupling plate 5 toward the distal end side in the straight line by a predetermined distance W9 in the horizontal direction. Accordingly, as illustrated in FIG. 22, when the joint metal 1d is viewed from outside, depressed portions extending from the bended portions 9 in the horizontal direction by the predetermined distance W8 are formed in the back-side portion 42 of the securing plate 4. On the outer surface of the coupling plate 5, as illustrated in FIG. 23, depressed portions extending from the bended portions 9 toward the distal end side of the coupling plates 5 in the horizontal direction by the predetermined distance W9 are formed. Thus, the joint metal 1g includes the bended-portion reinforcing beads 12, which are disposed in communication with the securing plate 4 from the coupling plate 5 through the bended portions 9. This allows improving the strength of the bended portions 9, thus suppressing falling over of the pair of coupling plates 5 when the securing plate 4 is fastened with fixtures such as bolts at a high torque. Additionally, the bended-portion reinforcing bead 12 is disposed to extend in the horizontal direction of the securing plate 4 and the coupling plate 5 by the respective predetermined distances W8 and W9. This allows improving the strength near the bended portions 9 of the securing plate 4 and the coupling plate 5.

The following describes a joint metal 1h according to a ninth embodiment of the present invention with reference to FIG. 25 and FIG. 26. As illustrated in FIG. 25 and FIG. 26, the joint metal 1h includes bended-portion reinforcing beads 12a and end-portion reinforcing beads 13. The bended-portion reinforcing beads 12a are disposed in communication with the securing plate 4 from the coupling plate 5 through the bended portions 9 at the boundaries between the securing plate 4 and the coupling plates 5. The end-portion reinforcing beads 13 are formed in both the end portions in the width direction of the securing plate 4 to be long in the vertical direction.

A plurality of the bended-portion reinforcing beads 12a are disposed at shorter intervals in the vertical direction than the bended-portion reinforcing beads 12 disposed in the joint metal 1g according to the eighth embodiment. Additionally, a width L9 of the bended-portion reinforcing bead 12a is formed to be a width larger than the width L8 of the bended-portion reinforcing bead 12 disposed in the joint metal 1g according to the eighth embodiment.

As illustrated in FIG. 25, the end-portion reinforcing bead 13 is formed to have a width W10 longer than the size extending in the horizontal direction from the bended portion 9 toward the securing plate 4 side of the bended-portion reinforcing bead 12a. The end-portion reinforcing beads 13 are formed over the vertical direction (the longitudinal direction) of both the end portions of the securing plate 4. The end-portion reinforcing bead 13 is formed by, for example, press work or similar work so as to project from the back-side portion 42 of the securing plate 4 toward the inside (the projection direction of the coupling plate 4). Accordingly, as illustrated in FIG. 25, in the case where the joint metal 1h is viewed from the outside, depressed portions in the vertically long shapes on both the ends of the back-side portion 42 of the securing plate 4. Here, this embodiment describes the example where the end-portion reinforcing beads 13 are formed over the vertical direction in both the end portions of the securing plate 4. This, however, should not be construed in a limiting sense. The end-portion reinforcing bead 13 may be formed to be broken in the course of the securing plate 4 in the vertical direction. Thus, the joint metal 1h includes the end-portion reinforcing beads 13 in both the end portions in the width direction of the securing plate. This allows improving the strength of both the ends in the width direction of the securing plate.

The following describes the experiment results of the measurement of the deformation amount in the pair of coupling plates 5 when the securing plates 4 of the joint metals 1d to 1g according to the present invention are fastened with the bolts 6 so as to be secured to the support material 2 as illustrated in FIGS. 27A and 27B. Here, measurement was performed on a distance W11 between the pair of coupling plates 5 in the position of Q illustrated in FIGS. 16A and 16B before the bolts were fastened and on the sizes of the distance W11 between the pair of coupling plates 5 when the bolts were fastened at 40 N·m and 80 N·m, so as to obtain the deformation rate with respect to the size before the bolts were fastened. In the experiments, the joint metals in the shapes described in the following working examples 4 to 7 and comparative examples 3 and 4 were used. Here, the joint metals in the working examples 4 to 7 and the comparative example 4 are different only in presence of the reinforcing portions and in shape, and otherwise similar to one another. The comparative example 3 employs the securing plate 4 and the coupling plate 5 that have plate thicknesses thicker than those of the working examples 4 to 7 and the comparative example 4.

The working example 4 employs the joint metal 1e where the securing-plate reinforcing beads 11 are disposed as illustrated in FIG. 19 and FIG. 20. In this joint metal 1e, the height H is 266 mm, the width W1 is 85 mm, the diameter Φ of the coupling hole 52 is 12.5 mm, the distance W2 from the base end of the coupling plate 5 up to the center of the coupling hole 52 is 65 mm, and a diameter Φ1 of the fixing hole 41 is 17 mm. For these values, the same applies to the other working examples 5 to 7 and the comparative examples 3 and 4. Additionally, a plate thickness t of the securing plate 4 and the coupling plate 5 is 2.3 mm. For this value, the same applies to the other working examples 5 to 7 and the comparative example 4. Here, the comparative example 3 employs the example that has the plate thickness t of the securing plate 4 and the coupling plate 5 is 3.2 mm. Additionally, a width W7 of the securing-plate reinforcing bead 11 is 3 mm, and the diameter of the arc on the inside of the securing-plate reinforcing bead 11 is 28 mm.

As illustrated in FIGS. 22 to 24, the working example 5 employs the joint metal 1g where the bended-portion reinforcing beads 12 are disposed. In this joint metal 1g, the width L8 of the bended-portion reinforcing bead 12 is 7 mm, the length W8 in the horizontal direction on the securing plate 4 side is 10 mm, and the length W9 in the horizontal direction on the coupling plate 5 side is 25 mm.

The working example 6 employs the joint metal 1d where the reinforcing ribs 10 are disposed as illustrated in FIGS. 16A and 16B to FIG. 18. In the reinforcing rib 10 of this joint metal 1d, W6 in the horizontal direction on the securing plate 4 side and the coupling plate 5 side is 10 mm and a length L7 in the vertical direction from the position of the inner surface in the securing plate 4 and the coupling plate 5 is 10 mm.

As illustrated in FIG. 21, the working example 7 employs the joint metal 1f where the reinforcing ribs 10 and the securing-plate reinforcing beads 11 are disposed. This joint metal 1f includes members similar to the securing-plate reinforcing bead 11 in the working example 4 and to the reinforcing rib 10 in the working example 6.

The comparative example 3 employs a joint metal where any of the reinforcing rib 10, the securing-plate reinforcing bead 11, and the bended-portion reinforcing bead 12 in the working examples 4 to 7 is not disposed and where the plate thickness t of the securing plate 4 and the coupling plate 5 is 3.2 mm.

The comparative example 4 employs a joint metal where any of the reinforcing rib 10, the securing-plate reinforcing bead 11, and the bended-portion reinforcing bead 12 in the working examples 4 to 7 is not disposed.

Table 2 below shows the measurement result of the working examples 4 to 7 and the comparative examples 3 and 4. Table 2 shows the size of the distance W11 of the pair of coupling plates 5 in the position of Q illustrated in FIGS. 16A and 16B before the bolts are fastened, the sizes of the distance W11 of the pair of coupling plates 5 when the bolts are fastened at 40 N·m and 80 N·m, and the deformation rates of the sizes when the bolts are fastened at 40 N·m and 80 N·m with respect to the size before the bolts are fastened.

As illustrated in Table 2, the working examples 4 to 7 are found to ensure equivalent or superior performances compared with the working example 3, which employs the joint metal where the plate thickness t of the securing plate 4 and the coupling plate 5 is formed to be thick like the conventional joint metal.

The working examples 4 to 7 are found to considerably improve the strength compared with the case using the joint metal where reinforcement is not performed and the plate thickness t of the securing plate 4 and the coupling plate 5 is thinned like the comparative example 4. Especially, at a high torque of 80 N·m, the difference is large.

Based on the measurement result in Table 2, as illustrated in the working examples 4 to 7, using the joint metal where any of the reinforcing rib 10, the securing-plate reinforcing bead 11, and the bended-portion reinforcing bead 12 is disposed allows suppressing falling over of the pair of coupling plates 5 as illustrated in FIGS. 27A and 27B even when the bolts are fastened at a high torque. This allows thinning of the plate thickness t of the securing plate 4 and the coupling plate 5 while ensuring the strength.

Here, the embodiment of the present invention is not limited to the above-described embodiments. Various modifications are possible without departing from the technical scope of the present invention.

• 1, 1a to 1h joint metal
• 2 support material
• 3 horizontal structural member
• 31 groove
• 4 securing plate
• 5, 5a to 5c coupling plate
• 51 pin groove
• 52 coupling hole
• 531 sixth deficient portion
• 532 and 533 second deficient portion
• 54 first deficient portion
• 55 fifth deficient portion
• 56 coupling portion
• 57 third deficient portion
• 58 fourth deficient portion
• 59 seventh deficient portion
• 8 drift pin (coupling tool)
• 9 bended portion
• 10 reinforcing rib
• 11 securing-plate reinforcing bead
• 12 bended-portion reinforcing bead
• 13 end-portion reinforcing bead
• A straight line
• B virtual line (straight line)