Joint metal fittings, deformed steel pipe column-beam joint structure, and steel pipe column joint structure

Abstract

To provide joint hardware, a joint structure of irregular-shaped steel pipes, a column-beam joint structure of irregular-shaped steel pipes and a joint structure of steel pipe column, which can be realized easily and for low costs.SOLUTION: Joint hardware 1 connects square steel pipes and circular members, wherein the joint hardware forms a cylindrical shape in which one end 1a is formed into a square shape and the other end 1b is formed into a circular shape, a triangular first steel plate 2 in which a bottom side 2b is formed into a linear shape and a triangular second steel plate 3 in which a bottom side 3b is bent to form an arc shape are provided by being alternately inverted upside down in a circumferential direction, both oblique sides 2s, 3s are welded together, and a cross-sectional shape changes continuously between the one end 1a and the other end 1b.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a metal joint for connecting a square steel pipe and a circular member, different This relates to the column-beam connection structure of steel tubular columns and the connection structure of steel tubular columns. [Background technology]

[0002] For example, a square steel pipe may be joined to a member with a circular cross section in a column of a building structure, etc. In such a case, a metal fitting is used between the square steel pipe and the member with a circular cross section, with one end connectable to the square steel pipe and the other end connectable to the member with a circular cross section. For example, Patent Document 1 discloses a metal fitting for connecting a steel pipe pole with a circular cross section and a steel pipe pole with a polygonal cross section. The cross-sectional shape of the end face of this metal fitting is formed to be substantially the same as the cross-sectional shape of the steel pipe pole to be connected. However, the metal fittings disclosed in Patent Document 1 are manufactured by casting or forging. Therefore, a casting mold for casting and a press mold for forging are required. The manufacture of these casting molds and press molds (so-called metal dies) is large-scale, requiring time and cost. In addition, a new die must be manufactured to change the shape (dimension) of the metal fittings to match the cross-sectional dimensions of the square steel pipe and the circular cross-section member to be joined, which is not easy. This manufacturing method using a press mold is suitable for mass-produced items such as piping, but is not suitable for items that must be produced in small quantities, such as joining steel pipe columns in building structures.

[0003] Patent Document 2 discloses a metal hollow joint for square steel pipes that can join the end of a square steel pipe to another structural member. This metal hollow joint for square steel pipes is provided on one axial end side of a cylindrical joint body, and includes a charging part with a square cross section that is inserted into the square steel pipe, and an end plate that is fixed to the other axial end side of the joint body. This metal hollow joint for square steel pipes joins the end of the square steel pipe to another structural member by inserting the charging part into the square steel pipe and bolting the end plate to another structural member. Patent Document 3 discloses a metal hollow joint for circular steel pipes that can join the end of a circular steel pipe to another structural member. This metal hollow joint for circular steel pipes is provided on one axial end side of a cylindrical joint body, and includes a charging part with a circular cross section that is provided on the other axial end side of the joint body and is inserted into the circular steel pipe, and a plate joint part to which an end plate is fixed to the end face of the other end side. This metal hollow joint for circular steel pipes joins the end of the circular steel pipe to another structural member by inserting the charging part into the circular steel pipe and bolting the end plate to the other structural member. The hollow joints disclosed in Patent Documents 2 and 3 are formed by hydroforming. Therefore, a mold for hydroforming is required for production. The production of the mold is large-scale, and requires time and cost. In addition, it is difficult to newly produce the shape (dimensions) of the mold according to the cross-sectional dimensions of the square steel pipes and other structural members to be joined. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 7-259181 [Patent Document 2] JP 2010-59624 A [Patent Document 3] JP 2010-101008 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a metal joint, a joint structure for deformed steel pipes, a beam-column joint structure for deformed steel pipes, and a joint structure for steel pipe columns that can be easily and inexpensively realized. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention employs the following means. In other words, the connecting hardware of the present invention is a connecting hardware that connects a square steel pipe and a circular component, and is tubular with one end formed in a square shape and the other end formed in a circular shape, and is formed by arranging steel plates of different shapes in the circumferential direction and welding them to each other, and is characterized in that the cross-sectional shape changes continuously between the one end and the other end. According to this configuration, by connecting a square steel pipe to one end of the joint metal and a circular member to the other end, the square steel pipe and the circular member can be easily connected via the joint metal. In addition, since the joint metal can be manufactured by arranging steel plates of different shapes in the circumferential direction and welding them together, the joint metal can be easily manufactured without using a die, which requires a lot of time and cost to manufacture. Furthermore, the steel plate can be cut out from the steel plate material and processed according to the cross-sectional shape and cross-sectional dimensions of the square steel pipe and the circular member, the interval between the square steel pipe and the circular member, etc., and the joint metal can be manufactured with a high degree of freedom even in small-scale production. Therefore, it is possible to provide a joint metal that connects a square steel pipe and a circular member, which can be easily and inexpensively realized.

[0007] In one aspect of the present invention, the column-beam joint structure of deformed steel pipes of the present invention is characterized in that a steel beam is joined to the outer surface of the connecting metal as described above, a square steel pipe column is joined to the one end side of the connecting metal, and a circular steel pipe column is joined to the other end side of the connecting metal. According to this configuration, by connecting a square steel pipe column and a circular steel pipe column with the above-mentioned metal joint, it becomes possible to continuously transmit stresses such as axial force and bending moment between the members, thereby increasing the degree of freedom in the design of architectural structures. Moreover, by using the above-mentioned metal joint, such effects can be achieved easily and inexpensively.

[0008] In one aspect of the present invention, the steel pipe column joint structure of the present invention is characterized in that the above-mentioned connecting metal is arranged with one end facing upward and the other end facing downward, a square steel pipe column is joined to the upper end side of the connecting metal, and a circular flange of a laminated rubber seismic isolation bearing part is joined to the lower end side of the connecting metal. According to this configuration, by connecting the square steel pipe column and the laminated rubber seismic isolation bearing with the above-mentioned metal joint, it becomes possible to continuously transmit stresses such as axial force and bending moment between the members. Moreover, by using the above-mentioned metal joint, such effects can be achieved easily and inexpensively. Effect of the Invention

[0009] According to the present invention, it is possible to provide metal joints, joint structures for deformed steel pipes, beam-to-column joint structures for deformed steel pipes, and joint structures for steel pipe columns that can be easily and inexpensively realized. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view showing the configuration of a metal joint according to an embodiment of the present invention; [Diagram 2] 2 is a perspective view showing a first steel plate constituting the metal joint of FIG. 1. FIG. [Diagram 3] 2 is a perspective view showing a second steel plate constituting the metal joint of FIG. 1. FIG. [Figure 4] FIG. 2 is a perspective view showing the assembled state of the metal joint shown in FIG. [Diagram 5] 1 is a perspective view showing the configuration of a column-beam joint structure for a deformed steel pipe according to a first embodiment of the present invention; [Figure 6] FIG. 5 is a perspective view showing the configuration of a joint structure for a steel pipe column according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a perspective view showing the configuration of a joint structure for a steel pipe column according to a third embodiment of the present invention. [Figure 8] FIG. 11 is a perspective view showing the configuration of a joint structure for a deformed steel pipe according to a fourth embodiment of the present invention. [Figure 9] A cross-sectional view showing the configuration of a modified example of a metal joint according to an embodiment of the present invention. [Figure 10] A cross-sectional view showing the configuration of another modified example of the metal joint according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention relates to a joint metal that connects a square steel pipe and a circular member, a column-beam joint structure of a deformed steel pipe that uses the joint metal to join a square steel pipe column and a circular steel pipe column, a joint structure of a square steel pipe column and a laminated rubber seismic isolation bearing using the joint metal, and a joint structure of a deformed steel pipe in which the joint metal is provided between a square steel pipe column and a circular steel pipe column. Specifically, the joint metal is made by alternately flipping up and down and welding the same number (e.g., four sheets) of triangular flat steel plates and triangular steel plates whose bases are bent in an arc shape out of the plane, with their hypotenuses butted against each other. Thus, the joint metal is a hollow body whose one end is square (e.g., quadrangle) and the other end is circular, and whose cross section changes continuously from square to circular to enable smooth stress transfer between the square steel pipe and the circular steel pipe. Hereinafter, with reference to the attached drawings, a description will be given of embodiments for implementing the metal joint, the joint structure of a deformed steel pipe, the beam-to-column joint structure of a deformed steel pipe, and the joint structure of a steel pipe column according to the present invention, based on the drawings. (Basic structure of metal joints) FIG. 1 is a perspective view showing the configuration of a metal joint according to an embodiment of the present invention. As shown in FIG. 1, the joint metal 1 is used to connect a square steel pipe and a circular member as shown in each of the following embodiments. This joint metal 1 is tubular and extends in the direction of the central axis. One end 1a of the joint metal 1 in the direction of the central axis is polygonal (e.g., rectangular) when viewed from the direction of the central axis. The other end 1b of the joint metal 1 in the direction of the central axis is circular when viewed from the direction of the central axis. The cross-sectional shape of the joint metal 1 changes continuously from circular to rectangular between the one end 1a and the other end 1b. The joint metal 1 is composed of four first steel plates 2 and four second steel plates 3. The joint metal 1 is formed into a cylindrical shape by welding together and integrating the first steel plates 2 and the second steel plates 3, which are alternately arranged in the circumferential direction around the central axis.

[0012] Fig. 2 is a perspective view showing a first steel plate constituting the metal joint of Fig. 1. In Fig. 2, the first steel plate 2 is shown upside down. As shown in Fig. 2, the first steel plate 2 has a base 2b and two oblique sides 2s, and forms a triangle shape when viewed from a direction perpendicular to the surface of the steel plate. In this embodiment, the lengths of the two oblique sides 2s are set to be equal. The first steel plate 2 is made of a flat steel plate in which the base 2b and the two oblique sides 2s each extend linearly. The length of the base 2b of the first steel plate 2 is set to match the width of one side of the square steel pipe to be joined to one end 1a. The two oblique sides 2s intersect at a top 2t on the opposite side to the base 2b. As will be described later, these two oblique sides 2s are welded to the second steel plate 3. In this embodiment, the top 2t where the two oblique sides 2s intersect is slightly chamfered to form a flat surface 2k so that the two oblique sides 2s are not adjacent to each other across a single angle. This is intended to prevent the welding of the already welded oblique side 2s from melting due to the welding heat when welding the other oblique side 2s after welding one oblique side 2s. Such a first steel plate 2 can be easily manufactured by cutting out a flat steel plate material to a predetermined size.

[0013] FIG. 3 is a perspective view showing a second steel plate constituting the metal joint of FIG. As shown in FIG. 3, the second steel plate 3 has a base 3b and two oblique sides 3s, and forms a triangular shape as a whole when viewed from a direction perpendicular to the steel plate surface. In this embodiment, the lengths of the two oblique sides 3s are set to be equal. The second steel plate 3 is curved so that the center part 3m in the width direction (circumferential direction) of the second steel plate 3 protrudes toward the outer periphery of the joint metal 1 with respect to the two oblique sides 3s. The base side 3b of the second steel plate 3 is curved to form an arc shape when viewed from below. The curvature radius of the base side 3b of the second steel plate 3 is set to match the curvature radius of the circular member connected to the other end 1b of the joint metal 1. The second steel plate 3 is formed so that the curvature radius gradually decreases from the base side 3b side toward the top part 3t side so that the oblique side 3s is linear. The top part 3t of the second steel plate 3 may be curved to match the curvature radius of the corner part when the corner part of the square steel pipe connected to one end 1a of the joint metal 1 is bent into an arc shape. Such a second steel plate 3 is manufactured by cutting out a flat steel plate material to a predetermined dimension and bending it by rolling, pressing, etc. In other words, the second steel plate 3 can be easily manufactured by ordinary metal processing without using a die as in casting, forging, or hydroforming.

[0014] FIG. 4 is a perspective view showing the assembled state of the metal joint shown in FIG. As shown in FIG. 4, when manufacturing the joint metal 1, the first steel plate 2 and the second steel plate 3 as described above are arranged alternately in the circumferential direction. At this time, the first steel plate 2 is turned upside down so that the top 2t faces downward and the bottom 2b faces upward. The first steel plate 2 is arranged so that the top 2t is sandwiched between the bottoms 3b of the two second steel plates 3 arranged on both sides in the circumferential direction. The second steel plate 3 is arranged so that the top 3t is sandwiched between the bottoms 3b of the two first steel plates 2 arranged on both sides in the circumferential direction. In this way, the oblique sides 2s and 3s of the first steel plate 2 and the oblique sides 3s of the second steel plate 3 are butted against each other, and the oblique sides 2s and 3s are welded together. In this way, the joint metal 1 as shown in FIG. 1 is manufactured. The plate thicknesses of the first steel plate 2 and the second steel plate 3 are set according to the plate thicknesses of the square steel pipe and the circular member (circular steel pipe) to be joined. When the plate thicknesses of the square steel pipe and the circular member are different, it is preferable to set the plate thicknesses of the first steel plate 2 and the second steel plate 3 according to the plate thickness of the square steel pipe or the circular member, whichever is thicker. Thus, the manufacturing method of the connecting hardware 1 in this embodiment is a manufacturing method of the connecting hardware 1 which connects a square steel pipe and a circular component, in which the first steel plate 2 is formed into a triangular shape with the base 2b being straight, and the second steel plate 3 is formed into a triangular shape with the base 3b curved so that it forms an arc, and the first steel plate 2 and the second steel plate 3 are arranged by alternately flipping them upside down in the circumferential direction so that the connecting hardware 1 has a tubular shape with one end 1a being polygonal (e.g., rectangular) and the other end 1b being circular, and the cross-sectional shape changes continuously between the one end 1a and the other end 1b, and the hypotenuses 2s, 3s of both plates are welded together.

[0015] (First embodiment) Next, a column-beam joint structure of a deformed steel pipe using the above-mentioned metal joint 1 according to this embodiment will be described. FIG. 5 is a perspective view showing the configuration of a beam-to-column joint structure for deformed steel pipes according to the first embodiment of the present invention. As shown in Figure 5, in the deformed steel pipe column-beam connection structure in this embodiment that joins a square steel pipe column (square steel pipe) 11 and a circular steel pipe column (circular member) 12, the above-mentioned connecting hardware 1 is provided at the connection portion J1 between the square steel pipe column 11, the circular steel pipe column 12, and the steel beam 21. The square steel pipe column 11 and the circular steel pipe column 12 constitute a steel pipe column 10 of a building structure. The square steel pipe column 11 is a cylindrical column having a rectangular shape in a plan view and extends in the vertical direction. The circular steel pipe column 12 is a cylindrical column having a circular shape in a plan view and extends in the vertical direction. The circular steel pipe column 12 is disposed vertically below the square steel pipe column 11, and the square steel pipe column 11 and the circular steel pipe column 12 are disposed concentrically. The square steel pipe column 11 and the circular steel pipe column 12 are connected via a joint metal 1. The lower end of the square steel pipe column 11 is connected to one end 1a of the joint metal 1 via an upper diaphragm 14. The upper end of the circular steel pipe column 12 is connected to the other end 1b of the joint metal 1 via a lower diaphragm 15. The upper diaphragm 14 and the lower diaphragm 15 are plate-shaped and disposed along a horizontal plane.

[0016] The steel beam 21 is joined to the steel pipe column 10. In this embodiment, the steel beam 21 is arranged, for example, on all four sides of the steel pipe column 10. Each steel beam 21 is provided at a height between the square steel pipe column 11 and the circular steel pipe column 12. The steel beam 21 is joined to the outer circumferential surface of the joint metal 1 between the square steel pipe column 11 and the circular steel pipe column 12. The steel beam 21 is made of H-shaped steel and integrally has a web 21a extending in the vertical direction and flanges 21b, 21c formed above and below the web 21a. The upper flange 21b of the steel beam 21 is welded to the upper diaphragm 14. The lower flange 21c of the steel beam 21 is welded to the lower diaphragm 15. The web 21a of the steel beam 21 is welded to the outer circumferential surface of the joint metal 1, specifically, to the flat portion formed by the flat first steel plate 2 in the joint metal 1. The portion of the metal joint 1 formed by the curved second steel plate 3 is disposed between the adjacent steel beams 21.

[0017] The connecting hardware 1 as described above connects a square steel pipe column 11, which is a square steel pipe, and a circular steel pipe column 12, which is a circular member. The connecting hardware 1 is tubular with one end 1a formed in a square shape and the other end 1b formed in a circular shape, and is formed by arranging steel plates 2 and 3 of different shapes in the circumferential direction and welding them together, so that the cross-sectional shape changes continuously between one end 1a and the other end 1b. According to this configuration, by connecting a square steel pipe column 11 to one end 1a of the joint metal 1 and connecting a circular steel pipe column 12 to the other end 1b, the square steel pipe column 11 and the circular steel pipe column 12 can be easily connected via the joint metal 1. In addition, since the joint metal 1 is made by arranging steel plates 2 and 3 of different shapes in the circumferential direction and welding them to each other, the joint metal 1 can be easily manufactured without using a die, which requires a lot of time and cost to manufacture. Furthermore, the steel plates 2 and 3 can be cut out and processed from a steel plate material according to the cross-sectional shape and cross-sectional dimensions of the square steel pipe column 11 and the circular steel pipe column 12, the interval between the square steel pipe and the circular member, etc., and the joint metal 1 can be manufactured with a high degree of freedom even in small-scale production. Therefore, it is possible to provide a joint metal 1 for connecting a square steel pipe and a circular member that can be easily and inexpensively realized.

[0018] In the column-beam joint structure of deformed steel pipes as described above, a steel beam 21 is joined to the outer surface of the joint metal 1, a square steel pipe column 11 is joined to one end 1a of the joint metal 1, and a circular steel pipe column 12 is joined to the other end 1b of the joint metal 1. According to this configuration, by joining the square steel pipe column 11 and the circular steel pipe column 12 with the above-mentioned connecting metal 1, the square steel pipe column 11 and the circular steel pipe column 12 can be connected with a continuous cross section. This enables continuous transmission of stresses such as axial force and bending moment between the members, thereby increasing the degree of freedom in designing architectural structures. Moreover, by using the above-mentioned connecting metal 1, the above-mentioned effects can be achieved easily and inexpensively.

[0019] Second Embodiment Next, a joint structure for a steel pipe column according to a second embodiment of the present invention will be described. In the second embodiment described below, the same reference numerals are given to the configurations common to the first embodiment, and the description thereof will be omitted. FIG. 6 is a perspective view showing the configuration of a joint structure for a steel pipe column according to the second embodiment of the present invention. As shown in Figure 6, the joint structure of the steel pipe column 10B in this embodiment is a joint structure between a square steel pipe column (square steel pipe) 11 and a circular laminated rubber seismic isolation bearing portion 30, and includes the square steel pipe column 11, the laminated rubber seismic isolation bearing portion 30, and the above-mentioned connecting hardware 1.

[0020] The laminated rubber seismic isolation bearing 30 is disposed at the lower end of the square steel pipe column 11 constituting the steel pipe column 10B. The laminated rubber seismic isolation bearing 30 includes a concrete base 31 and a seismic isolation device body 32 placed on the base 31. The seismic isolation device body 32 includes an upper flange (circular member) 32a, a lower flange 32b, and a laminated rubber part 32c. The upper flange 32a and the lower flange 32b are plate-shaped circular when viewed from the top-bottom direction. The upper flange 32a and the lower flange 32b are disposed at an interval in the top-bottom direction. The laminated rubber part 32c is sandwiched between the upper flange 32a and the lower flange 32b. The laminated rubber part 32c is formed by stacking steel plates and elastic bodies made of rubber-based materials in multiple layers in the top-bottom direction. The lower flange 32b of the seismic isolation device body 32 is bolted to the base 31.

[0021] The connecting metal 1 is provided at the connection J2 between the laminated rubber seismic isolation bearing 30 and the square steel pipe column 11. The connecting metal 1 is provided so that one end 1a faces upward and the other end 1b faces downward. The square steel pipe column 11 and the laminated rubber seismic isolation bearing 30 are connected via the connecting metal 1. The lower end of the square steel pipe column 11 is connected to the one end 1a side of the connecting metal 1 via an upper diaphragm 14. A base plate 35 is joined to the other end 1b side of the connecting metal 1. The base plate 35 is disposed below the lower diaphragm 15 provided on the other end 1b side of the connecting metal 1. The base plate 35 is joined to the lower end of the tubular portion 36 extending downward from the lower diaphragm 15, and is provided integrally on the other end 1b side of the connecting metal 1. The base plate 35 is bolted to the upper flange 32a of the seismic isolation device main body 32.

[0022] In this embodiment, a steel beam 21 is connected to the steel pipe column 10B at a height between the square steel pipe column 11 and the laminated rubber seismic isolation bearing portion 30. The steel beam 21 is joined to the outer circumferential surface of the connecting metal 1 between the square steel pipe column 11 and the tubular portion 36. An upper flange 21b of the steel beam 21 is welded to the upper diaphragm 14. A lower flange 21c of the steel beam 21 is welded to the lower diaphragm 15. A web 21a of the steel beam 21 is welded to the outer circumferential surface of the connecting metal 1.

[0023] In the steel pipe column joint structure as described above, the joint metal 1 is arranged with one end 1a facing upward and the other end 1b facing downward, and a square steel pipe column 11 is joined to the upper end side of the joint metal 1, and a circular flange 32a of the laminated rubber seismic isolation bearing part 30 is joined to the lower end side of the joint metal 1. According to this configuration, by joining the square steel pipe column 11 and the laminated rubber seismic isolation bearing 30 with the above-mentioned connecting metal 1, it becomes possible to continuously transmit stresses such as axial force and bending moment between the components. In addition, for example, when a square steel pipe column 11 is joined to a circular flange 32a via a base plate 35, if the square steel pipe column 11 is simply joined to the base plate 35 directly, the stress of the square steel pipe column 11 is not continuously transmitted to the flange 32a because the cross-sectional shape of the square steel pipe column 11 and the shape of the flange 32a are different. For this reason, in the past, it was necessary to provide ribs to join the square steel pipe column 11 and the base plate 35, respectively. However, according to the above-mentioned configuration, since the stress is continuously transmitted as described above, it is not necessary to provide ribs as in the past. In this way, by using the metal joint 1, the above-mentioned effects can be achieved easily and at low cost.

[0024] (Third embodiment) Next, a joint structure for a steel pipe column according to a third embodiment of the present invention will be described. In the third embodiment described below, the same reference numerals are given to the configurations common to the first and second embodiments, and the description thereof will be omitted. FIG. 7 is a perspective view showing the configuration of a joint structure for a steel pipe column according to the third embodiment of the present invention. As shown in Figure 7, the joint structure of the steel pipe column 10C in this embodiment is a joint structure between a square steel pipe column (square steel pipe) 11C and a circular laminated rubber seismic isolation bearing 30, and includes a square steel pipe column 11C, a laminated rubber seismic isolation bearing 30, and the above-mentioned connecting hardware 1.

[0025] In this embodiment, a steel beam 21 is connected to the lower end of the square steel pipe column 11C. An upper diaphragm 14C and a lower diaphragm 15C are provided at a distance from each other at the lower end of the square steel pipe column 11C. The steel beam 21 is joined to the outer circumferential surface of the square steel pipe column 11C. An upper flange 21b of the steel beam 21 is welded to the upper diaphragm 14C. A lower flange 21c of the steel beam 21 is welded to the lower diaphragm 15C. A web 21a of the steel beam 21 is welded to the outer circumferential surface of the square steel pipe column 11C. The laminated rubber seismic isolation bearing 30 is disposed below the square steel pipe column 11C that constitutes the steel pipe column 10C. The laminated rubber seismic isolation bearing 30 includes an upper flange (circular member) 32a. The connecting metal 1 is provided at the connection J3 between the laminated rubber seismic isolation bearing 30 and the square steel pipe column 11C. The connecting metal 1 is provided so that one end 1a faces upward and the other end 1b faces downward. The square steel pipe column 11C and the laminated rubber seismic isolation bearing 30 are connected via the connecting metal 1. The lower end of the square steel pipe column 11C is connected to one end 1a of the connecting metal 1 via a lower diaphragm 15C. A base plate 35C is joined to the other end 1b of the connecting metal 1. The base plate 35C is bolted to the upper flange 32a of the seismic isolation device main body 32.

[0026] In the steel pipe column joint structure as described above, the joint metal 1 is arranged with one end 1a facing upward and the other end 1b facing downward, and a square steel pipe column 11C is joined to the upper end side of the joint metal 1, and a circular flange 32a of the laminated rubber seismic isolation bearing part 30 is joined to the lower end side of the joint metal 1. According to this configuration, by joining the square steel pipe column 11C and the laminated rubber seismic isolation bearing 30 with the above-mentioned connecting metal 1, it becomes possible to continuously transmit stresses such as axial force and bending moment between the members. In addition, for example, when a square steel pipe column 11C is joined to a circular flange 32a via a base plate 35C, if the square steel pipe column 11C is directly joined to the base plate 35C, the stress of the square steel pipe column 11C is not continuously transmitted to the flange 32a because the cross-sectional shape of the square steel pipe column 11C and the shape of the flange 32a are different. For this reason, in the past, it was necessary to provide ribs to join the square steel pipe column 11C and the base plate 35C, respectively. However, according to the above-mentioned configuration, since the stress is continuously transmitted as described above, it is not necessary to provide ribs as in the past. In this way, by using the metal joint 1, the above-mentioned effects can be achieved easily and at low cost.

[0027] (Fourth embodiment) Next, a joining structure of a deformed steel pipe according to a fourth embodiment of the present invention will be described. In the fourth embodiment described below, the same reference numerals are given to the components common to the first and second embodiments, and the description thereof will be omitted. FIG. 8 is a perspective view showing the configuration of a joint structure for a deformed steel pipe according to the fourth embodiment of the present invention. As shown in Figure 8, the deformed steel pipe joint structure in this embodiment is a deformed steel pipe joint structure that joins a square steel pipe column (square steel pipe) 11 and a circular steel pipe column (circular member) 12, and the above-mentioned joint hardware 1 is provided at the connection portion J4 between the square steel pipe column 11 and the circular steel pipe column 12. The square steel pipe column 11 and the circular steel pipe column 12 constitute a steel pipe column 10D of an architectural structure. The square steel pipe column 11 is a cylindrical column having a rectangular shape in a plan cross section, and extends in the vertical direction. The circular steel pipe column 12 is a cylindrical column having a circular shape in a plan cross section, and extends in the vertical direction. The circular steel pipe column 12 is disposed vertically below the square steel pipe column 11. The square steel pipe column 11 and the circular steel pipe column 12 are connected via a connecting metal 1. The lower end of the square steel pipe column 11 is connected to one end 1a of the connecting metal 1. The upper end of the circular steel pipe column 12 is connected to the other end 1b of the connecting metal 1. In the connecting metal 1, the top 3t of the second steel plate 3 is curved with a curvature radius that matches the bending radius of the corner portion 11c of the square steel pipe column 11. As a result, the top 3t of the second steel plate 3 and the corner portion 11c at the lower end of the square steel pipe column 11 form a continuous curved surface, making it possible to easily perform welding and improving the continuity of stress transmission between the square steel pipe column 11 and the connecting metal 1.

[0028] In the joint structure of the deformed steel pipe as described above, a square steel pipe column 11 is joined to one end 1a of the joint metal 1, and a circular steel pipe column 12 is joined to the other end 1b of the joint metal 1. According to this configuration, by connecting the square steel pipe column 11 and the circular steel pipe column 12 with the above-mentioned metal joint 1, it becomes possible to continuously transmit stresses such as axial force and bending moment between the members, thereby increasing the degree of freedom in designing architectural structures. Moreover, by using the above-mentioned metal joint 1, such effects can be achieved easily and inexpensively.

[0029] (Modifications of each embodiment) Furthermore, the connecting metal fittings, connecting structure of deformed steel pipes, column-beam connecting structure of deformed steel pipes, and connecting structure of steel pipe columns of the present invention are not limited to the above-mentioned embodiments described with reference to the drawings, and various modified examples are contemplated within the technical scope. For example, in the connecting metal 1 illustrated in each of the above embodiments, the diagonal dimension S (see Figure 1) of the rectangular cross-sectional portion at one end 1a of the connecting metal 1 is approximately equal to the diameter D (see Figure 1) of the other end 1b of the connecting metal 1, but this is not limited to this. For example, as shown in Figure 9, the connecting metal 1 may be formed so that the sum (4L) of the lengths L of the four sides of the rectangular cross-sectional portion at one end 1a of the connecting metal 1 is approximately equal to the circumference M of the circular cross-sectional portion at the other end 1b. Also, as shown in FIG. 10, the metal joint 1 may be formed so that the length L of one side of the rectangular cross-sectional portion at one end 1a of the metal joint 1 and the diameter D of the other end 1b of the metal joint 1 are approximately equal. 9 and 10, the connecting metal 1 shown in FIG. 1 is depicted upside down, i.e., the other end 1b forming a circle is positioned above and one end 1a forming a polygon (e.g., a rectangle) is positioned below. The connecting metal 1 may be positioned upside down in this manner. For example, in the first and fourth embodiments, the connecting metal 1 is used to connect the square steel pipe column 11 located above and the circular steel pipe column 12 located below, but the connecting metal 1 may be used to connect the circular steel pipe column 12 located above and the square steel pipe column 11 located below.

[0030] (Other variations) In the joint metal 1 shown in the above embodiment, the first steel plate 2 and the second steel plate 3 each form a so-called isosceles triangle with the two hypotenuses 2s, 3s of equal length, but this is not limited to this. If the square steel pipe at one end 1a of the joint metal 1 and the circular member at the other end 1b are not concentrically arranged but are eccentric, the lengths of the two hypotenuses 2s, 3s of the first steel plate 2 and the second steel plate 3 may be made different. In the above embodiment, the square steel pipe has a rectangular cross section, but the cross section of the square steel pipe connected to one end 1a of the joint metal 1 may be triangular or polygonal with 5 or more sides. In that case, the number of pairs of the first steel plate 2 and the second steel plate 3 constituting the joint metal 1 may be set according to the number of sides of the polygonal square steel pipe. In addition, in the column-beam joint structure of deformed steel pipes and the joint structure of deformed steel pipes according to the above embodiments, a square steel pipe column is provided at the upper end side of the joint metal and a circular steel pipe column is provided at the lower end side, but it is also possible to provide a circular steel pipe column at the upper end side of the joint metal and a square steel pipe column at the lower end side. In addition, the configurations described in the above embodiments can be selected or changed as appropriate without departing from the spirit of the present invention. [Explanation of symbols]

[0031] 1 Joint metal fittings 10, 10B, 10C, 10D Steel pipe column 1a One end 11, 11C Square steel pipe column (square steel pipe) 1b Other end 12 Circular steel pipe column (circular member) 2 First steel plate 21 Steel beam 2b Base 30 Laminated rubber seismic isolation bearing 2s hypotenuse 32a flange 3 Second steel plate 35, 35C Base plate 3b Bottom J1~J4 connection 3s hypotenuse

Claims

1. A metal joint that connects a square steel pipe and a circular member, It is cylindrical with one end square and the other end circular, a first steel plate having one side formed to be linear and a second steel plate having one side curved to be arc-shaped are arranged in a circumferential direction and welded to each other so that the one side of the first steel plate forms the one end and the one side of the second steel plate forms the other end, A metal joint characterized in that the cross-sectional shape changes continuously between the one end and the other end.

2. A column-beam connection structure for deformed steel pipes, characterized in that a steel beam is connected to the outer peripheral surface of the connecting metal as described in claim 1, a square steel pipe column is connected to the one end side of the connecting metal, and a circular steel pipe column is connected to the other end side of the connecting metal.

3. A steel pipe column connection structure characterized in that the connecting metal as described in claim 1 is arranged so that one end faces upward and the other end faces downward, a square steel pipe column is connected to the upper end side of the connecting metal, and a circular flange of a laminated rubber seismic isolation bearing part is connected to the lower end side of the connecting metal.

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