Metal fittings for connecting hollow rectangular pipes in construction.

Abstract

The present invention provides a lightweight, high-strength metal joint that allows multiple hollow rectangular pipes made of metal such as aluminum or steel to be easily fastened together using only screw fastening, as well as a support structure using the joint, and a steel frame structure in which multiple support structures are connected by purlins. [Solution] The metal joint 10 comprises a metal core material 11 having opposing planes and a reinforcing material 12 fixed to the core material 11 so as to cover at least two opposing surfaces of the core material 11, and the width of the joint 10 in two orthogonal directions is loosely fitted with a minute gap between it and the inner diameter of the hollow rectangular metal pipe 15 to be connected.

Description

Technical Field

[0001] The present invention relates to a metal joint for connecting a plurality of hollow square pipes to each other.

Background Art

[0002] Conventionally, in steel frame structures, when connecting beams such as H-shaped (I-shaped) steel materials or connecting columns and beams, methods such as butting and welding them to each other or screwing and fixing them using auxiliary plates were often used. On the other hand, in recent years, especially in lightweight structures such as carports, it has become mainstream to use hollow square pipes made of metal such as aluminum and steel and connect them to each other by welding or screwing.

[0003] As a method of connecting the above-mentioned hollow square pipes to each other, a method of using a joining body or a metal joint by utilizing the internal space of the hollow square pipe is known. In Patent Document 1, an example of screwing / welding square steel pipe columns 1a and 1b through a joining body 2 is shown. Also, in Patent Document 2, for the hollow square support pipes 7 and 8 of a metal L-shaped joint 12, a hollow square vertical beam pipe 5 and a cross beam pipe 6 are similarly inserted and joined by welding or adhesion.

[0004] Furthermore, in Patent Document 3, in order to connect a plurality of hollow metal columnar members 1, it is shown that the outer surface of a metal connecting fixture 2 composed of a plurality of angle pipes 21 is inserted into the hollow interior of the metal columnar member 1 and fixed with an adhesive.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the prior art, when joining hollow rectangular steel pipe columns as described in Patent Document 1, it is necessary to insert a joint of a predetermined length with an outer diameter approximately equal to the inner diameter of the hollow rectangular steel pipes so as to straddle them. Similarly, in Patent Document 2, hollow rectangular vertical and horizontal beam pipes are inserted into a hollow rectangular support pipe of a metal L-shaped joint and joined by welding or adhesive, making it clear that the outer diameter of the support pipe is approximately equal to the inner diameter of the hollow rectangular vertical and horizontal beam pipes.

[0007] On the other hand, Patent Document 3 states that "the cross-sectional shape of the square pipe of the metal connecting jig is not limited, but is the same as the cross-sectional shape of the hollow interior of the metal columnar member, and is slightly smaller than this cross-sectional shape," and also states that "it is preferable to arrange a spacer as a means of stably securing the gap between the metal connecting jig and the metal columnar member."

[0008] However, firstly, the outer diameter of the square pipe joint, hollow square vertical beam pipes, and horizontal beam pipes must be approximately the same as the inner diameter of the hollow square pipes to be connected. This means that it is not possible to select and combine steel pipes as specified in JIS-G3466 (General Structural Square Steel Pipes). Therefore, if one of the steel pipes is a square steel pipe as described in JIS-G3466, the other square steel pipe that fits into it must be specially manufactured, which presents problems in terms of manufacturing costs and lead times.

[0009] Furthermore, because the joints are made by welding or bonding, constructing steel frame structures requires on-site welding or bonding work, which poses a problem as the work is complicated and prevents shortening the delivery time. In addition, once welding or bonding is performed, disassembly and reassembly are not possible, making it difficult to change the height or length of the steel frame structure.

[0010] One way to solve this problem is to connect multiple hollow rectangular pipes using screw fastenings when connecting them with hollow rectangular steel pipe joints or hollow rectangular vertical and horizontal beam pipes (for example, Japanese Utility Model Publication No. 2-68905). However, in order to improve the bending strength of the connection, it is necessary to significantly improve the strength of the hollow rectangular steel pipe joint, such as by increasing the wall thickness of the hollow rectangular steel pipe in the joint, which also leads to the problem of a significant increase in the weight of the joint. [Means for solving the problem]

[0011] This invention has been made in view of the problems of the aforementioned technology, and aims to provide a lightweight and high-strength metal joint that can easily fasten multiple hollow rectangular pipes made of metal such as aluminum or steel together using only screw fastening.

[0012] The first solution according to the present invention is a joint that fits into the internal space of a hollow rectangular pipe made of metal such as aluminum or steel and connects the hollow rectangular pipes together, characterized in that it comprises a metal core material having opposing planes and a reinforcing material fixed to the core material so as to cover at least two of the opposing outer surfaces of the core material.

[0013] Furthermore, it is preferable that the core material is a hollow rectangular steel pipe or a combination thereof having at least one rectangular or square cross-section.

[0014] Furthermore, the reinforcing material is a plate-shaped reinforcing plate, and the joint formed by fixing the reinforcing plate to the core material is fitted such that its width in two orthogonal directions (width in the Z direction and width in the Y direction in Figure 1) is loosely fitted with the inner diameter of the hollow rectangular metal pipe to be connected with a minute gap, and is connected to the hollow rectangular metal pipe to be connected by screw fastening. Furthermore, the reinforcing material is a plate-shaped reinforcing plate with a plurality of protrusions, the protrusions are provided to protrude in the width direction of the reinforcing plate, and the protrusions loosely fit into the internal space of the hollow rectangular tubes to connect the hollow rectangular tubes together. It is characterized by the following. [Effects of the Invention]

[0015] According to the present invention, a hollow rectangular steel pipe having at least one rectangular or square cross-section is used as the core material, and a reinforcing plate, whose thickness and width are freely selected to fit loosely with minimal play according to the inner diameter of the hollow rectangular metal pipe to be connected, is fixed to the core material so as to cover at least two opposing outer surfaces of the core material. Multiple protrusions, which are provided projecting in the width direction of the reinforcing plate, are recessed into the internal space of the hollow rectangular tubes, connecting the hollow rectangular tubes together. This allows us to provide lightweight metal joints with excellent bending strength and torsional strength.

[0016] (Examples of application) As an example of application of the present invention, a T-shaped, Π-shaped, or L-shaped metal joint is provided with a reinforcing plate fixed to the core material so as to cover at least two sides of the core material, a crossbeam pipe of at least one hollow rectangular metal pipe connected to the joint in the horizontal direction (X-axis direction or Y-axis direction in Figure 1), a column pipe of a hollow rectangular metal pipe connected to the joint in the vertical direction (Z-axis direction in Figure 1) such that one end is perpendicular to the crossbeam pipe, and an RC foundation with a shaft, which is provided so as to be connected to the other end of the column pipe, and the connection is fastened with screws to form a support structure.

[0017] A further advantage is that the two opposing surfaces of the aforementioned core material to which the reinforcing plate is fixed face each other in a direction perpendicular to the axis perpendicular to the ground (Z-axis direction) (the X-axis direction or Y-axis direction in Figure 1).

[0018] According to this application example, the various joints and RC foundation parts with shafts mentioned above can be manufactured in advance at a factory rather than at the construction site, and necessary adjustments can be made there. As a result, the foundation pouring (reinforced concrete formwork, concrete pouring, etc.), welding, and bonding work that were previously required at the construction site become unnecessary, and the large-scale work required is reduced to just screw fastening assembly, resulting in a significant reduction in delivery time.

[0019] Furthermore, by fixing reinforcing plates to two opposing surfaces of the metal core material facing each other in directions perpendicular to the vertical axis (Z-axis direction) relative to the ground (X-axis direction or Y-axis direction), there is an advantage in that the bending strength and torsional strength of T-shaped, Π-shaped, or L-shaped metal joints can be significantly improved when manufacturing support structures.

[0020] A further application example according to the present invention is that a plurality of the aforementioned column structures are prepared, and the column structures are connected to each other by a plurality of roofs to form a steel frame structure.

[0021] According to this further application example, if a plurality of column structures are connected to form a roof portion above the roof, a carport can be easily realized, and if a column structure is added, an extension can be easily made. Also, when used as a carport, the column structure is substantially T-shaped and the column can be installed near the center. Compared with a large-scale structure where the columns are at the four corners, there is an additional effect that the columns do not get in the way and the operability during parking is greatly improved.

[0022] Furthermore, by changing the length of the aforementioned column pipe and sequentially changing the height direction of the column structure, an inclined steel frame structure can be fabricated, so it can also be easily used as a pedestal for a solar power generation system. Therefore, there is an effect of realizing a very versatile steel frame structure.

Brief Description of the Drawings

[0023] [Figure 1] A perspective view showing a first embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 2] A view showing a state where metal hollow square pipes are connected using the metal joint of FIG. 1, where (a) is an overall perspective view and (b) is an exploded perspective view. [Figure 3] A sectional view taken along the line A-A of FIG. 2. [Figure 4] A detailed view of part B of FIG. 2. [Figure 5] A perspective view showing a second embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 6] A view showing a state where metal hollow square pipes are connected using the metal joint of FIG. 5. [Figure 7] A sectional view taken along the line C-C of FIG. 6. [Figure 8]This figure shows a modified example of a second embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view. [Figure 9] This is a perspective view showing a third embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 10] This is a cross-sectional view taken along the DD arrow in Figure 9. [Figure 11] This is a perspective view showing a fourth embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 12] This is a cross-sectional view taken along the EE arrow in Figure 11. [Figure 13] This is a perspective view showing a fifth embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 14] This is a cross-sectional view taken along the FF arrow in Figure 13. [Figure 15] This is a perspective view showing a sixth embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 16] Figure 15 shows a configuration in which hollow metal rectangular pipes are connected using the metal fittings shown in Figure 15. [Figure 17] This is a cross-sectional view taken along the GG arrow in Figure 16. [Figure 18] This is a perspective view showing a seventh embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 19] This figure shows the state of connecting hollow metal rectangular pipes using the metal fittings shown in Figure 18. [Figure 20] This is a cross-sectional view taken along the line HH in Figure 19. [Figure 21] This is a perspective view showing an eighth embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 22] Figure 21 shows a configuration in which hollow metal rectangular pipes are connected perpendicularly in a T-shape using the metal fittings shown in Figure 21. (a) is an overall perspective view, and (b) is an exploded perspective view thereof. [Figure 23]This is a perspective view showing a ninth embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 24] Figure 23 shows a configuration in which hollow metal rectangular pipes are connected perpendicularly in a T-shape using the metal fittings shown in Figure 23. (a) is an overall perspective view, and (b) is an exploded perspective view thereof. [Figure 25] This is a perspective view showing a tenth embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 26] Figure 25 shows a configuration in which hollow metal rectangular pipes are connected perpendicularly in a pi shape using the pi-shaped metal fittings shown in Figure 25. (a) is an overall perspective view, and (b) is an exploded perspective view thereof. [Figure 27] This is a perspective view showing an eleventh embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 28] Figure 27 shows a configuration in which hollow metal rectangular pipes are connected perpendicularly in an L-shape using an L-shaped metal fitting, with (a) being an overall perspective view and (b) being an exploded perspective view. [Figure 29] This is a perspective view showing a twelfth embodiment of the metal joint of the present invention, where (a) is an overall perspective view and (b) is an exploded perspective view thereof. [Figure 30] This is an overall perspective view showing a first support structure constructed by connecting hollow rectangular metal pipes in a T-shape perpendicularly using a T-shaped metal joint according to the eighth embodiment of the present invention, and connecting the other end of one hollow rectangular pipe to an RC foundation with an axis. [Figure 31] Figure 30 is an exploded perspective view showing the assembly of the support structure. [Figure 32] This is an overall perspective view showing a second support structure constructed by connecting two hollow rectangular metal pipes in a pi shape perpendicularly using a pi-shaped metal joint according to the tenth embodiment of the metal joint of the present invention, and connecting the other ends of the two hollow rectangular pipes to an RC foundation with a shaft. [Figure 33] Figure 32 is an exploded perspective view showing the assembly of the support structure. [Figure 34]This is a perspective view showing a third support structure in which two sets of support structures are connected by a hollow square metal connecting pipe, using two T-shaped metal joints according to the eighth embodiment of the present invention. [Figure 35] Figure 34 is an exploded perspective view showing the assembly of the support structure, where (a) is a perspective view of a method of connecting two RC foundations with shafts to the other ends of two hollow square metal pipes, (b) is a perspective view of a method of connecting two T-shaped metal joints with hollow square metal pipes, (c) is a perspective view of a method of connecting the metal joint assembly connected in (b) to the two hollow square metal pipes connected to the two RC foundations with shafts in (a), and (d) is a perspective view of a method of connecting two hollow square metal pipes from both sides of the metal joint assembly in the state of (c). [Figure 36] This is a perspective view of a steel frame structure created by using multiple support structures as shown in Figure 30 and connecting each support structure with purlins. [Figure 37] Figure 30 is a perspective view of another steel frame structure created by connecting support structures of different heights with purlins. [Figure 38] Figure 36 is a perspective view showing a steel frame structure used as a carport. [Figure 39] This is a photograph showing an example of a T-shaped joint that was actually prototyped. [Figure 40] This is a photograph showing an example of the construction of a prototype support structure. [Figure 41] This is a photograph showing an example of a completed prototype steel frame structure. [Figure 42] This is an exploded perspective view showing another example of a metal joint, this time with an integrated reinforcing plate. [Figure 43] This perspective view shows yet another example of a metal joint, this time using a block-shaped reinforcing material. [Modes for carrying out the invention]

[0024] The embodiments for carrying out the present invention will be described in detail below with reference to the drawings. As shown in Figure 1, the X, Y, and Z axes are defined as follows: the Z-axis (up and down in the figure) is the direction perpendicular to the ground; the X-axis (front and back in the figure) is the direction perpendicular to the Z-axis; and the Y-axis (left and right in the figure) is the direction perpendicular to the Z and X axes, respectively. These are shown in the perspective views (Figures 1, 2, 21, 27, 29, 30, and 36) and the cross-sectional view (Figure 3). The Z-axis direction is also referred to as the vertical direction, and the X-axis and Y-axis directions are also referred to as the horizontal directions. (The same applies hereafter.)

[0025] (First embodiment) Figures 1 to 4 show a metal joint 10 of the first embodiment of the present invention, and its configuration / structure will be explained according to the figures. First, the metal joint 10 uses a hollow square steel pipe 11 as a core material, as specified in JIS-G3466, and two flat reinforcing plates 12 are attached to two opposing side surfaces 11f in the Y-axis (left and right) direction of the hollow square steel pipe 11, with the mounting surfaces 12f of the reinforcing plates 12 facing each other, and welded to the hollow square steel pipe 11. (In Figure 1, the * marks indicate welding, which is shown as multiple ★ marks in the figure.) The welded parts are near the corners of the outer shape of the hollow square steel pipe 11 and the mounting surface 12f is located between the mounting surface 12f, and continuous welding is possible, but fillet welding may also be performed at multiple locations. (See Figure 3, ● marks)

[0026] The reinforcing plates 12 on both sides are identical in shape, and multiple convex guide portions 12a are provided on the central part in the longitudinal direction (X-axis direction) and near both end faces, protruding in the width direction (Z-axis direction) of the reinforcing plate 12 and on the same line. The dimension CH between the convex guide portions 12a in the width direction (Z-axis direction) is such that they loosely fit with the upper and lower inner surfaces 15a of the hollow rectangular metal tube (beam tube) 15 shown in Figure 2, and abut with a small gap. In addition, the central convex guide portion 12a has projections 12b above and below that protrude in the width direction (Z-axis direction). Multiple stepped portions 12c are provided in the longitudinal direction (X-axis direction) as clearances between the convex guide portions 12a, set one step lower. Furthermore, the multiple through holes 12d in the reinforcing plate 12 and the multiple through holes 11d in the hollow rectangular steel pipe 11 of the core material are welded together so as to be on the same axis, allowing bolts to pass through when attaching and fixing the metal hollow rectangular pipe (beam pipe) 15, which will be described later.

[0027] The external dimensions of the metal joint 10, which is made by welding reinforcing plates 12 to the opposing sides 11f of the hollow rectangular steel pipe 11 core material, are such that the height direction (Z-axis direction) is the dimension CH between the convex guide portions 12a, and the width direction (Y-axis direction) is the dimension CW between the surfaces 12e of the two reinforcing plates 12. The length direction (X-axis direction) dimension CL is appropriately selected depending on the hollow rectangular metal pipe (beam pipe) 15 to be connected.

[0028] In the hollow square pipe assembly 210, which connects metal hollow square pipes (beam pipes) 15 on both sides using metal joints 10, as shown in Figure 2, the metal hollow square pipes (beam pipes) 15 are inserted from both ends of the metal joints 10 in the direction of the arrows and secured by tightening with hexagonal bolts 18 and nuts 19 from both sides of the through hole 15d in the Y-axis direction. As shown in Figure 4, the abutment surface 15e of the metal hollow square pipe (beam pipe) 15 abuts against the end face of the projection 12b, and the through holes 12d, 11d, and 15d are aligned on the same axis, through which the hexagonal bolts 18 are inserted. At this time, the abutment surfaces 15c of the metal hollow square pipes (beam pipes) 15 may also abut against each other.

[0029] The hollow rectangular pipe (beam pipe) 15 made of metal may be a general structural rectangular steel pipe as specified in JIS-G3466, similar to the hollow rectangular steel pipe 11, or it may be a hollow rectangular pipe made of aluminum alloy (such as A6063), but its inner dimensions are PH in the height direction (Z-axis direction) and PW in the width direction (Y-axis direction), as shown in Figure 2(b), and a metal joint 10 is inserted inside it as shown in Figure 3. Here, the dimensional relationships are PH > CH and PW > CW. As a result, the surface 12e of the reinforcing plate 12 is in contact with the inner surface 15b of the hollow rectangular pipe (beam pipe) 15 in the Y-axis direction with a small gap, and similarly, the convex guide portions 12a of the reinforcing plates 12 on both sides are in contact with the inner surface 15a in the Z-axis direction with a small gap.

[0030] When connecting a hollow rectangular metal pipe (beam pipe) 15 to a metal joint 10, the convex guide portions 12a near both ends of the metal joint 10 are inserted into the opening on the abutment surface 15c side of the hollow rectangular metal pipe (beam pipe) 15. However, if the width (Z-axis direction) dimension of the reinforcing plate 12 is CH across its entire surface, the workability is poor, and the dimension must also be made across the entire surface. Therefore, a stepped portion 12c is provided in the longitudinal direction (X-axis direction) with a step down to allow clearance between the convex guide portions 12a, improving the ease of insertion. In addition, there is the advantage that the CH dimension only needs to be made in the necessary parts, making manufacturing easier. Finally, when insertion is complete, the convex guide portions 12a near both ends of the reinforcing plate 12 are located on the back side of the hollow rectangular metal pipe (beam pipe) 15, and the convex guide portion 12a in the center is located near the ends.

[0031] As shown in Figure 2, when a bending moment M (around the Y axis) is applied to the metal hollow rectangular pipe (beam pipe) 15 relative to the metal joint 10, the lower inner surface of the inner surface 15a in the Z-axis direction near the end face of the metal hollow rectangular pipe (beam pipe) 15 comes into contact with the lower end face of the convex guide portion 12a in the center of the reinforcing plate 12, and the upper inner surface of the inner surface 15a in the Z-axis direction on the far side comes into contact with the upper end face of the convex guide portion 12a near the end face of the reinforcing plate 12, and both are subjected to pressure. (Indicated by arrow P in Figure 2)

[0032] The metal joint 10 is manufactured by welding reinforcing plates 12 to both sides of a hollow rectangular steel pipe 11, which serves as the core material. Compared to the case of the hollow rectangular steel pipe 11 alone, the combined effect of the reinforcing plates 12 in the width direction (Z-axis direction) significantly improves the second moment of area I, resulting in very high bending rigidity. As a result, the wall thickness of the hollow rectangular steel pipe 11 can be reduced, thereby lowering the weight of the metal joint 10. Furthermore, since the joint is manufactured by welding two reinforcing plates 12, the combined effect of the reinforcing plates 12 improves the second moment of area I and the polar second moment of area IP compared to the case of the hollow rectangular steel pipe 11 alone, resulting in very high bending and torsional rigidity.

[0033] <Example 1> In the first specific embodiment of the first design, a hollow rectangular steel pipe 11 was made of STKR400 from JIS-G3466 with an outer diameter of 150 mm x 75 mm and a thickness of t=3.2 mm. Flat reinforcing plates 12 made of SS400 from JIS-G3101 (rolled steel for general structural use) with a thickness of 6 mm were welded to both sides 11f of the long side. On the other hand, a hollow rectangular metal pipe (beam pipe) 15 was made of STKR400 from JIS-G3466 with an outer diameter of 200 mm x 100 mm and a thickness of t=6 mm.

[0034] As a result, the inner diameter of the hollow rectangular metal pipe (beam pipe) 15 becomes PH=188mm and PW=88mm, and the width (Y-axis direction) of the metal joint 10 becomes CW=87mm. Furthermore, the dimension CH between the convex guide portions 12a of the reinforcing plate 12 can be arbitrarily selected, but here it is set to CH=186mm to improve insertability and minimize rattle.

[0035] (Second embodiment) Figures 5 to 7 show a metal joint 20 according to a second embodiment of the present invention. The only differences from the metal joint 10 are that the core material is the same, and the shape of the reinforcing plate 22 and the method of attachment to the hollow rectangular steel pipe 11 are different.

[0036] First, the shape of the reinforcing plate 22 is such that the upper end face is bent 90° in an L shape with respect to the Z-axis (up and down) direction, and mounting surfaces 22f and 22g are formed on the inside, facing the side surface 11f and mounting surface 11g of the hollow rectangular steel pipe 11, respectively. In Figure 5, two reinforcing plates 22 are in contact with the hollow rectangular steel pipe 11, with their side surfaces 11f and mounting surfaces 22f of the reinforcing plates 22 facing each other, and the mounting surface 22g of the reinforcing plate 22 contacts the mounting surface 11g of the top surface of the hollow rectangular steel pipe 11, and are welded to the hollow rectangular steel pipe 11.

[0037] The two reinforcing plates 22 are positioned facing each other, and when the side surface 11f of the hollow square steel pipe 11 and the mounting surface 22f of the reinforcing plate 22 come into contact, the tip portions 22j face each other with a gap δ between them (see Figures 5 and 7). This gap δ is provided so that the mounting surface 22g of the reinforcing plate 22 and the mounting surface 11g of the hollow square steel pipe 11 can be reliably welded at the ● mark in Figure 7, and the weld marks do not protrude from the upper surface 22h. In this state, as shown in Figure 5(a), the metal joint 20 is manufactured by welding the tip portion 22j of the reinforcing plate 22 to the hollow square steel pipe 11 on the upper surface in the Z-axis direction. (Welding is indicated by * marks at multiple ★ marks in Figure 5)

[0038] Furthermore, the other end of the reinforcing plate 22 is provided with a convex guide portion 22a, a projection portion 22b, and a stepped portion 22c, similar to the case of the reinforcing plate 12. When the reinforcing plate 22 is welded to the hollow square steel pipe 11 and the metal joint 20 is completed, the multiple through holes 22d and through holes 11d provided on the surface 22e are aligned on the same axis. Also, as shown in the areas marked with ● on both sides of Figure 7, the welded portions near the other end of the reinforcing plate 22 are similarly welded at multiple locations near the corners of the outer shape of the hollow square steel pipe 11, such as the mounting surface 22f, using fillet welding.

[0039] In the hollow square pipe assembly 220, which connects two hollow square pipes (beam pipes) 25 using a metal joint 20, as shown in Figure 6, the hollow square pipes (beam pipes) 25 are inserted from both ends of the metal joint 20 and secured by tightening with hexagonal bolts 18 and nuts 19 from both sides of the through hole 25d in the Y-axis direction. As shown in Figures 5 and 7, the dimensions of the metal joint 20 are CH, which is the dimension between the top surface 22h and the convex guide portions 22a on both sides, and CW, which is the dimension between the surfaces 22e of the two reinforcing plates 22, with PH being the dimension between the inner surfaces 25a in the Z-axis (up and down) direction and PW being the dimension between the inner surfaces 25b in the Y-axis (left and right) direction, while the dimensions of the metal joint 20 are CH, which is the dimension between the top surface 22h and the convex guide portions 22a on both sides, and CW, which is the dimension between the surfaces 22e of the two reinforcing plates 22, with the relationship PH > CH and PW > CW.

[0040] The advantage of the second embodiment is that the shape of the reinforcing plate 22 is such that the upper end face of the reinforcing plate 22 is bent at an L-shape at 90° with respect to the Z-axis (up and down) direction, forming mounting surfaces 22f and 22g, which are welded on three sides facing the side surface 11f and mounting surface 11g of the hollow rectangular steel pipe 11, respectively. As a result, the strength of the reinforcing plate 22 itself is improved, and because three sides are welded, the second moment of area I and the polar moment of inertia IP of the area are improved compared to the metal joint 10 using the flat reinforcing plate 12 of the first embodiment. Therefore, the bending strength against bending moment M (around the Y axis) and bending moment N (around the Z axis), and the torsional strength against torsional moment S (around the X axis) are further improved.

[0041] <Example 2> In the second specific embodiment of the second design, the hollow rectangular steel pipe 11 was made of STKR400 of JIS-G3466 with an outer diameter of 150 mm x 75 mm and a thickness of t=3.2 mm. Reinforcement plates 22 made of SS400 of JIS-G3101 (rolled steel for general structural use) with a thickness of 6 mm and bent into an L shape were welded to both sides 11f of the long side. On the other hand, the hollow rectangular metal pipe (beam pipe) 25 was similarly made of STKR400 of JIS-G3466 with an outer diameter of 200 mm x 100 mm and a thickness of t=6 mm. In addition, the gap δ between the tip portions 22j of the reinforcement plates 22 was left at 5 mm and they were welded so that the weld marks did not protrude from the upper surface 22h.

[0042] As a result, the inner diameter of the hollow rectangular metal pipe (beam pipe) 25 becomes PH = 188 mm and PW = 88 mm, and the width (Y-axis direction) of the metal joint 20 becomes CW = 87 mm. Furthermore, the dimension CH between the upper surface 22h of the reinforcing plate 22 and the convex guide portions 22a on both sides can be arbitrarily selected, but here it was set to CH = 186 mm.

[0043] In the second embodiment, an example was shown in which two reinforcing plates 22 were used to attach and weld around three sides of the hollow rectangular steel pipe 11 (both side surfaces 11f and the mounting surface 11g). However, as shown in the metal joint 90 of Figure 42, a U-shaped reinforcing plate 92 can be formed by integrating two reinforcing plates 22 and attached and welded over the hollow rectangular steel pipe 11. In this case, the inner mounting surfaces 92f of the reinforcing plate 92 abut against the side surfaces 11f of the hollow rectangular steel pipe 11, and the inner mounting surface 92g abuts against the mounting surface 11g and is welded. Here, the relief hole 92k of the reinforcing plate 92 is a relief hole to ensure that the reinforcing plate 92 is securely welded to the mounting surface 11g of the hollow rectangular steel pipe 11 and that the weld marks do not protrude from the upper surface 92h, and welding is performed through this relief hole 92k. Furthermore, considering that the inner mounting surface of the reinforcing plate must be in firm contact with the side surfaces 11f on both sides of the hollow rectangular steel pipe 11, it is preferable to use two reinforcing plates 22 rather than a single integrated reinforcing plate 92.

[0044] (Modified version of the second embodiment) Figure 8 shows a modified metal joint 30 of the second embodiment of the present invention. The difference from the metal joint 20 of the second embodiment is that the core material is not a hollow square steel pipe but an H-beam or I-beam as specified in JIS-G3192 (Hot-rolled steel shapes and dimensions...). Reinforcing plates 22 are provided facing the H-beam 31 core material from both sides, and the mounting surfaces 31f and 22f, and mounting surfaces 31g and 22g of the H-beam 31 core material and the reinforcing plates 22 are in contact and welded in the same manner. Specifically, for the H-beam 31 core material, an H-beam with standard cross-sectional dimensions of 150mm x 75mm can be used instead of the hollow square steel pipe 11 of JIS-G3466 STKR400.

[0045] (Third embodiment) Figures 9 and 10 show a metal joint 40 according to a third embodiment of the present invention. The difference from the metal joint 10 of the first embodiment is that the core material is different, and it is a core material assembly 44. In the previous embodiments, the core material was a single piece such as a hollow square steel pipe 11 or an H-shaped steel 31, but the core material assembly 44 of the metal joint 40 is a hollow square steel pipe 41 with two auxiliary plates (spacers) 43 welded to it.

[0046] Here, the inner surface 43b of the auxiliary plate (spacer) 43 is welded to the opposing upper and lower mounting surfaces 41g of the hollow square steel pipe 41 at the * portions (4 places) indicated by ● marks, respectively, to form the core material assembly 44. The shape of the reinforcing plate 42 is similar to that of the reinforcing plate 22, with the upper end face bent 90° in an L shape with respect to the Z axis (up and down) direction, and mounting surfaces 42f and 42g are formed on the inside, facing the four end faces 43a and mounting surfaces 43g of the auxiliary plate (spacer) 43 of the core material assembly 44, respectively. In Figure 9, the two reinforcing plates 42 are in contact with the core material assembly 44 in between, with the end face 43a of the auxiliary plate (spacer) 43 and the mounting surface 42f of the reinforcing plate 42 facing each other. The mounting surface 42g of the reinforcing plate 42 is in contact with the mounting surface 43g of the top surface of the auxiliary plate (spacer) 43, and they are welded together at the * parts (a total of 3 places) indicated by the ● marks, as in the second embodiment.

[0047] The advantage of the third embodiment is that the degree of freedom in selecting the dimensions of the hollow square steel pipe 41 used in the core material assembly 44 is greatly improved, and the second moment of area I of the core material assembly 44 is also increased by welding auxiliary plates (spacers) 43 to the top and bottom, which is expected to further improve the bending strength.

[0048] <Example 3> In the third embodiment, a specific example 3 uses a hollow rectangular steel pipe 41 made of STKR400 of JIS-G3466 with an outer diameter of 150mm x 100mm and a thickness of t=3.2mm. Two flat auxiliary plates (spacers) 43 made of SS400 of JIS-G3101 (rolled steel for general structural use) with a thickness of 6mm are welded to the mounting surfaces 41g on both short sides, with a distance of 125mm between the end faces 43a at both ends, to form a core assembly 44. Furthermore, L-shaped reinforcing plates 42 made of SS400 of JIS-G3101 (rolled steel for general structural use) with a thickness of 6mm are welded so that there is a gap δ of 5mm between the tips 42j of the reinforcing plates 42 and that the weld marks do not protrude from the upper surface 42h. On the other hand, the metal hollow rectangular tube (beam tube) 45 was similarly made using STKR400 of JIS-G3466, with an outer diameter of 200 mm x 150 mm and a thickness of t=6 mm.

[0049] As a result, the inner diameter of the hollow rectangular metal pipe (beam pipe) 45 becomes PH = 188 mm and PW = 138 mm, and the width (Y-axis direction) of the metal joint 40 becomes CW = 137 mm. Furthermore, the dimension CH between the upper surface 42h of the reinforcing plate 42 and the convex guide portions 42a on both sides can be arbitrarily selected, but here it was set to CH = 186 mm.

[0050] In the third embodiment of the present invention, the core assembly 44 is made by welding two auxiliary plates (spacers) 43 to a hollow square steel pipe 41. However, as shown by the dashed line (imaginary line) in Figure 10, another auxiliary plate (spacer) 47 may be provided to fill the gap between the side surface 41f of the hollow square steel pipe 41 and the mounting surface 42f of the reinforcing plate 42, and the reinforcing plate 42 may be fixed to the hollow square steel pipe 41 by welding or fixing screws 49. In this case, the fixing screws 49 should be countersunk screws or the like as specified in JIS B1111 so as not to protrude from the surface 42e of the reinforcing plate 42.

[0051] (Fourth embodiment) Figures 11 and 12 show a metal joint 50 according to a fourth embodiment of the present invention. The difference from the metal joint 10 is that two hollow rectangular steel pipes 51 are placed spaced apart on a core material, and two U-shaped reinforcing plates 52 are welded and connected to surround the hollow rectangular steel pipes 51.

[0052] First, the shape of the reinforcing plate 52 is such that its upper and lower end faces are bent at a 90° angle in the Z-axis (up and down) direction, and it has an inner mounting surface 52f and an upper and lower mounting surface 52g, which contact the side surfaces 51f and mounting surfaces 51g of two spaced-apart hollow square steel pipes 51, respectively. In Figure 11, the two reinforcing plates 52 are attached to each other with their side surfaces 51f and mounting surfaces 52f facing each other, sandwiching the two hollow square steel pipes 51, and the mounting surfaces 52g of the upper and lower reinforcing plates 52 contact the mounting surfaces 51g of the two hollow square steel pipes 51, and are welded together to connect the two hollow square steel pipes 51. In this case, the external dimensions of the metal joint 50 are such that the height CH is equal to the distance between the upper surfaces 52h of the reinforcing plates 52 that do not directly affect the hollow square steel pipe 51, and the width CW is equal to the distance between the surfaces 52e of the two reinforcing plates 52 welded to the hollow square steel pipe 51.

[0053] As shown in Figure 12, the hollow rectangular steel pipe 51 and the reinforcing plate 52 are welded at three locations marked with * (●) for each hollow rectangular steel pipe 51. Since the welding of the short side of the hollow rectangular steel pipe 51 is performed on the inside of the U-shaped reinforcing plate 52, the reinforcing plate 52 is provided with multiple relief holes 52k that open near the welding points. The mounting surface 52f of the reinforcing plate 52 and the vicinity of the corners of the outer shape of the hollow rectangular steel pipe 51 are welded through these relief holes 52k.

[0054] In this way, by arranging two hollow rectangular steel pipes 51 spaced apart as core material, connecting them with two U-shaped reinforcing plates 52 that surround the hollow rectangular steel pipes 51, and welding all four sides to the core material, the metal joint 50 has a very large second moment of area I, which greatly improves its bending strength, and also increases the degree of freedom in selecting the hollow rectangular steel pipes 51.

[0055] <Example 4> In the fourth embodiment, specific example 4 used two hollow square steel pipes as core materials. The hollow square steel pipe 51 was made of STKR400 according to JIS-G3466, with an outer diameter of 125 mm x 75 mm and a thickness of t=3.2 mm. Two U-shaped reinforcing plates 52 made of SS400 according to JIS-G3101 (rolled steel for general structural use), with a plate thickness of 6 mm, were welded to the side 51f and mounting surface 51g of the pipe, with a gap δ of 5 mm between the tips 52j of the reinforcing plates 52 facing each other, and the welding was done so that the weld marks did not protrude from the upper surface 52h. On the other hand, the metal hollow square pipe (beam pipe) 55 was similarly made of STKR400 according to JIS-G3466, with an outer diameter of 200 mm x 150 mm and a thickness of t=6 mm.

[0056] As a result, the inner diameter of the hollow rectangular metal pipe (beam pipe) 55 becomes PH = 188 mm and PW = 138 mm, and the width (Y-axis direction) of the metal joint 50 becomes CW = 137 mm. Furthermore, the dimension CH between the upper surfaces 52h of the reinforcing plate 52 can be arbitrarily selected, but here it was set to CH = 186 mm.

[0057] (Fifth embodiment) Figures 13 and 14 show a metal joint 60 according to a fifth embodiment of the present invention. The difference from the metal joint 10 is that auxiliary plates (spacers) 63 are provided on the upper and lower mounting surfaces 11g of the hollow square steel pipe 11 as the core material, and four L-shaped reinforcing plates 62 are welded and connected to the core material assembly 64 so as to surround it.

[0058] First, as shown in Figure 14, auxiliary plates (spacers) 63 of a certain thickness are welded to the upper and lower mounting surfaces 11g of the hollow rectangular steel pipe 11 as a core material, at the points marked with ●, to form a core material assembly 64. Four reinforcing plates 62 are provided to surround the core material assembly 64 from four directions, and the side surface 11f and mounting surface 62f and mounting surface 63f and mounting surface 62g of each plate are in contact and welded at four points marked with ● and *.

[0059] At this time, the respective ends 62j of the reinforcing plates 62 are arranged to face each other, with a gap δ between them (4 locations, see Figure 14). This gap δ is provided so that the side surface 11f of the hollow square steel pipe 11 and the mounting surface 62f, and the mounting surface 62g of the reinforcing plate 62 and the mounting surface 63f of the auxiliary plate 63 can be reliably welded, and the weld marks do not protrude from the upper surface 62h and surface 62e of the reinforcing plate 62. In this case, the external dimensions of the metal joint 60 are such that the height CH is equal to the distance between the upper surfaces 62h of the reinforcing plates 62 welded to the core assembly 64, and the width CW is equal to the distance between the surfaces 62e of the four reinforcing plates 62 welded to the hollow square steel pipe 11.

[0060] In this way, the core assembly 64 is constructed by welding auxiliary plates (spacers) 63 to a hollow rectangular steel pipe 11, and by covering all four sides of the core with four L-shaped reinforcing plates 62 so as to surround the hollow rectangular steel pipe 11 and auxiliary plates (spacers) 63 and welding them, the metal joint 60 has a very large second moment of area I, similar to the fourth embodiment, and its bending strength is greatly improved. In addition, by using four L-shaped reinforcing plates 62, the height CH of the outer dimensions of the core assembly 64 can be adjusted with the auxiliary plates (spacers) 63, making it easier to determine the dimensions of CH, compared to the U-shaped reinforcing plate 52 of the fourth embodiment.

[0061] <Example 5> In the fifth specific embodiment, the hollow rectangular steel pipe 11 was made of STKR400 of JIS-G3466 with an outer diameter of 150 mm x 75 mm and a thickness of t=3.2 mm. Flat auxiliary plates (spacers) 63 made of JIS-G3194 (hot-rolled flat steel) with dimensions of 12 (thickness) x 50 (width) were welded to the mounting surfaces 11g on both sides of the short side. In addition, four L-shaped reinforcing plates 62 made of SS400 of JIS-G3101 (rolled steel for general structural use) with a plate thickness of 6 mm were welded so that the mounting surface 62g and mounting surface 63f and the mounting surface 62f and the side surface 11f were in contact, with a gap δ of 5 mm between the tip portions 62j of the reinforcing plates 62 facing each other, and so that the weld marks do not protrude from the upper surface 62h. On the other hand, the hollow rectangular metal tube (beam tube) 15 was the same as in Example 1, using STKR400 of JIS-G3466 with an outer diameter of 200 mm x 100 mm and a thickness of t=6 mm.

[0062] As a result, the inner diameter of the hollow rectangular metal pipe (beam pipe) 15 becomes PH = 188 mm and PW = 88 mm, and the width (Y-axis direction) of the metal joint 60 becomes CW = 87 mm. Furthermore, the dimension CH between the upper surfaces 62h of the reinforcing plate 62 becomes CH = 186 mm.

[0063] (Sixth embodiment) Figures 15 to 17 show a metal joint 70 according to a sixth embodiment of the present invention. The difference from the metal joint 10 is that instead of a hollow square steel pipe 11 as the core material, one hollow square steel pipe 76 and two hollow square steel pipes 77 are provided on both sides, and their contact points are integrated by welding to form a core material assembly 74, and two reinforcing plates 72 are welded so as to contact the opposing sides 77f of the core material assembly 74.

[0064] First, as shown in Figure 15, one hollow rectangular steel pipe 76 and two hollow rectangular steel pipes 77 are provided on either side as the core material. This shape is similar to the H-shaped steel 31 described in the modified example of the second embodiment of the present invention. In other words, the shape of the H-shaped steel 31 is realized by combining multiple hollow rectangular steel pipes. Therefore, a hollow rectangular steel pipe 76 is placed between the two hollow rectangular steel pipes 77 to connect them, and the two are joined by welding at the contact points indicated by the * marks in Figure 17 to form a core material assembly 74.

[0065] Furthermore, the mounting surfaces 72f of two reinforcing plates 72 are brought into contact with the sides 77f on both sides of the short side of the hollow rectangular steel pipe 77 that constitutes the core material assembly 74, and a metal joint 70 is fabricated by welding at four locations marked with * and ●. Note that if relief holes 72k (not shown) are provided in the reinforcing plate 72 as shown in Figure 12, the reinforcing plate 72 can be welded to the other corners of the hollow rectangular steel pipe 77 through the relief holes 72k to improve the overall strength.

[0066] Figure 16 shows a hollow square pipe (beam pipe) 75 made of metal inserted from both ends of a metal joint 70 and fastened with hexagonal bolts 48 and nuts 19 from both sides in the Y-axis direction to create a hollow square pipe connector 270. This structure allows the height direction (Z-axis direction) PH of the inner surface dimension of the hollow square pipe (beam pipe) 75 of metal to be made very large, so its second moment of area I becomes very large and the bending strength is greatly improved. Therefore, even if the wall thickness of the hollow square steel pipes 76 and 77 is made thin, high strength can be ensured, and there is an advantage in that high strength can be achieved. Furthermore, because the inner surface dimension PH of the hollow square pipe (beam pipe) 75 of metal can be made large, not only the second moment of area I of the metal joint 70 but also the polar moment of inertia IP of the area necessary for improving torsional strength can be made very large, and as will be described later, there is also the advantage that when connected to the column pipe of a support structure, a support with high bending strength and torsional strength can be realized.

[0067] <Example 6> In the sixth specific embodiment, the sixth hollow square steel pipe 76 was made of STKR400 according to JIS-G3466, with an outer diameter of 150 mm x 75 mm and a thickness of t=3.2 mm, and the sixth hollow square steel pipe 77 was made of STKR400 according to JIS-G3466, with an outer diameter of 125 mm x 75 mm and a thickness of t=3.2 mm. Two hollow square steel pipes 77 were placed horizontally, and the short side of the hollow square steel pipe 76 was brought into contact with the long side of the two pipes and welded in four places to form a core assembly 74. In addition, two flat reinforcing plates 72 made of SS400 according to JIS-G3101 (rolled steel for general structural use), with a thickness of 6 mm, were welded in four places indicated by the * marks, so that the side surface 77f of the hollow square steel pipe 77 and the mounting surface 72f of the reinforcing plates 72 were in contact. On the other hand, the hollow rectangular metal pipe (beam pipe) 55 used was STKR400 according to JIS-G3466, with an outer diameter of 350mm x 150mm and a thickness of t=6mm.

[0068] As a result, the inner diameter of the hollow rectangular metal pipe (beam pipe) 55 becomes PH = 338 mm and PW = 138 mm, and the width (Y-axis direction) of the metal joint 70 becomes CW = 137 mm. Furthermore, the dimension CH between the convex guide portions 72a of the reinforcing plate 72 can be arbitrarily selected, but here it was set to CH = 336 mm.

[0069] (Seventh Embodiment) Figures 18 to 20 show a metal joint 80 according to the seventh embodiment of the present invention. The difference from the metal joint 10 is that a hollow rectangular steel pipe 81 is used as the core material, and in the reinforcing plate 82 welded to its side surface 81f, three cut-out protrusions 82j and 82k of the same height are provided approximately in the center in the width direction (Z-axis direction) so as to protrude from the surface 82e in the longitudinal direction (X-axis direction).

[0070] First, a hollow rectangular steel pipe 81 is provided as the core material, and reinforcing plates 82 are welded to both sides 81f of the pipe at four locations marked with * in Figure 20. On the other hand, the reinforcing plate 82 has three cut-out protrusions 82j and 82k of the same height formed approximately in the center in the width direction (Z-axis direction) so as to protrude from the surface 82e in the longitudinal direction (X-axis direction). When this reinforcing plate 82 is welded to the side 81f of the hollow rectangular steel pipe 81 to produce a metal joint 80, the distance between the protruding end faces 82je and 82ke of the welded reinforcing plates 82 on both sides becomes CW.

[0071] When a hollow rectangular pipe connector 280 is manufactured by connecting two hollow rectangular pipes (beam pipes) 85 using this metal joint 80, the cross-section is as shown in Figure 20, with the protruding end faces 82je and 82ke of the reinforcing plates 82 on both sides loosely fitting and contacting the inner surfaces (left and right) 85b of the hollow rectangular pipe (beam pipe) 85 at approximately the center. On the other hand, the convex guide portions 82a of the reinforcing plates 82 on both sides loosely fitting and contacting the inner surfaces (top and bottom) 85a of the hollow rectangular pipe (beam pipe) 85. At this time, the contact position of the convex guide portion 82a is at a position away from the inner corner of the hollow rectangular pipe (beam pipe) 85.

[0072] Generally, hollow square steel pipes as defined in JIS-G3466 often have a small curve (corner radius) on the inside. When using the metal joint 80 of the seventh embodiment, it is possible to reliably contact the flat surface of the inner surface (top and bottom) 85a while avoiding this dimensionally unstable corner radius, thus providing the effect of stable connection.

[0073] <Example 7> In the specific example 7 of the seventh embodiment, the hollow rectangular steel pipe 81 was made of STKR400 according to JIS-G3466, with an outer diameter of 150 mm x 100 mm and a thickness of t=3.2 mm. On the other hand, the reinforcing plate 82 was made of SS400 according to JIS-G3101 (rolled steel for general structural use), with a plate thickness of 6 mm, and was a flat plate shape with three cut-out projections 82j and 82k of the same height, with a height of 12.5 mm, protruding from the surface 82e in the longitudinal direction (X direction) approximately in the center in the width direction (Z direction). This reinforcing plate 82 was welded at four locations indicated by *, with the mounting surface 82f in contact with the side surface 81f of the hollow rectangular steel pipe 81. In addition, the metal hollow rectangular pipe (beam pipe) 85 was made of STKR400 according to JIS-G3466, with an outer diameter of 200 mm x 150 mm and a thickness of t=6 mm.

[0074] As a result, the inner diameter of the hollow rectangular metal pipe (beam pipe) 85 becomes PH=188mm and PW=138mm, and the width direction (Y-axis direction) of the metal joint 80 is the distance CW=137mm between the protruding end faces 82je and 82ke. Furthermore, the dimension CH between the convex guide portions 82a of the reinforcing plate 82 can be arbitrarily selected, but here it is set to CH=186mm. Note that the position where the convex guide portions 82a of the reinforcing plate 82 contact is 13mm inward from both inner surfaces (left and right) 85b. Note that by changing the height of the cut-out protrusions 82j and 82k, the distance CW between the protruding end faces 82je and 82ke can also be freely set.

[0075] The above describes the case in which two hollow rectangular metal pipes (beam pipes) are connected in series, from the first to the seventh embodiment. The technical features of the metal joint of the present invention can be summarized as follows. 1) In a metal joint, when reinforcing plates are welded to two opposing surfaces of the core material: First embodiment, sixth embodiment, seventh embodiment 2) In a metal joint, when reinforcing plates are welded to three surfaces including two opposing surfaces of the core material: Second embodiment, third embodiment 3) In a metal joint, when reinforcing plates are welded to four surfaces including two opposing surfaces of the core material: Fourth embodiment, fifth embodiment In other words, the most important feature is the provision of reinforcing plates on at least two opposing surfaces of the core material. As a result, compared to the conventional case of a core material alone (hollow rectangular steel pipe), the combined effect of the reinforcing plates significantly improves the second moment of area I and the polar moment of inertia IP, resulting in very high bending and torsional rigidity. Furthermore, increasing the number of welded surfaces of the core material to three or four surfaces will further enhance the effect.

[0076] Furthermore, another technical feature of the metal joint of the present invention is that, with the exception of the modifications of the second embodiment, the core material is always a hollow rectangular steel pipe or a combination thereof having at least one rectangular or square cross-section. This is because using a hollow rectangular steel pipe improves the second moment of area I, resulting in significantly increased rigidity and reduced weight.

[0077] When connecting hollow rectangular metal pipes (beam pipes), the reinforcing material is a plate-shaped reinforcing plate, and the joint formed by fixing the reinforcing plate to the core material can be fitted so that the width in two orthogonal directions (width in the Z direction and width in the Y direction in Figure 1) is loosely fitted with a minute gap between it and the inner diameter of the hollow rectangular metal pipe to be connected. This has the advantage that the minute gap can be adjusted by selecting the shape and dimensions of the reinforcing material. In addition, although the reinforcing material has been described as a plate-shaped reinforcing plate in both embodiments and examples, as long as it can be loosely fitted with a minute gap between it and the inner diameter of the hollow rectangular metal pipe to be connected, for example, the reinforcing plate 82 in Figure 18 is not limited to a plate-shaped reinforcing plate, it may be a block-shaped reinforcing material 97 as shown in Figure 43, or a combination of a plate-shaped reinforcing plate and a block-shaped reinforcing material may be used (see Figure 43, explanation omitted).

[0078] Furthermore, when using the various metal joints mentioned above, the orientation in which they are installed relative to the load is important. For example, as shown in Figure 2, the bending strength against the bending moment M (around the Y axis) is greatest when the two opposing surfaces face each other in a direction perpendicular to the axis perpendicular to the ground (the Z axis in Figure 2) (either the X-axis or Y-axis in Figure 2). Therefore, it is effective to select and use this orientation when manufacturing the support structures and steel frame structures described later.

[0079] From here on, we will explain based on various joint embodiments, focusing not on cases where hollow rectangular metal pipes (beam pipes) are connected in series, but rather on cases where hollow rectangular metal pipes (beam pipes) intersect with each other, such as when one hollow rectangular metal pipe (beam pipe) is connected to another.

[0080] (Eighth embodiment) Figures 21 and 22 show a metal T-shaped joint 110 according to the eighth embodiment of the present invention. Its configuration / structure will be described according to the figures. First, the core material of the metal T-shaped joint 110 is a T-shaped core material assembly 114 formed when the lower mounting surface 111g of the hollow square steel pipe 111 and the end surface of the hollow square steel pipe 119 abut at approximately the center of the front-to-back (X-axis direction) position of the hollow square steel pipe 111, and the abutting portion is welded around the perimeter (4 sides) (see Figure 21(b)*). At this time, the hollow square steel pipe 111 and the hollow square steel pipe 119 are hollow square steel pipes having the same cross-sectional shape, and the side surfaces 111f and 119f are on the same plane.

[0081] The metal T-shaped joint 110 is manufactured by welding two T-shaped reinforcing plates 112, each having a roughly T-shaped flat section 112s and a flat section 112t, to the T-shaped core assembly 114, with the mounting surfaces 112sf and 112tf of the T-shaped reinforcing plates 112sf and 112tf facing each other (indicated by * in Figure 21, with multiple ★ marks indicating welding). The welding locations are near the corners of the outer shapes of the hollow square steel pipes 111 and 119, and are similar to those in Figure 3 of the metal joint 10 of the first embodiment. Continuous welding is possible, but fillet welding may be performed at multiple locations. (See ● marks in Figure 3)

[0082] The T-shaped reinforcing plate 112 has an external shape similar to the reinforcing plate 12 of the metal joint 10, with multiple convex guide portions 112sa and 112ta provided on the flat portion 112s and flat portion 112t. The convex guide portion 112sa located approximately in the center of the X-axis (front-back) direction of the flat portion 112s is further provided with a projection 112b that protrudes in the width direction (Z-axis direction).

[0083] The T-shaped hollow rectangular pipe connector 310, which connects metal hollow rectangular pipes (beam pipes) 115 in the X-axis direction on both sides and metal hollow rectangular pipes (column pipes) 116 in the downward Z-axis direction using a metal T-shaped joint 110, is fixed by inserting the metal hollow rectangular pipes (beam pipes) 115 in the direction of the arrows from both ends of the metal T-shaped joint 110 and tightening them with hexagonal bolts 18 and nuts 19 from both sides in the Y-axis direction, as shown in Figure 22. At this time, as shown in Figure 22, the abutment surface 115e of the metal hollow rectangular pipe (beam pipe) 115 abuts against the end surface of the projection 112b. The metal hollow rectangular pipe (column pipe) 116 is inserted from below the metal T-shaped joint 110 in the direction of the arrow, and its end surface 116d abuts against the convex guide portion 112ta at the base of the metal T-shaped joint 110 and is fixed by tightening with hexagonal bolts 18 and nuts 19. Furthermore, the notched relief portion 115h of the metal hollow rectangular pipe (beam pipe) 115 is the relief portion of the metal hollow rectangular pipe (column pipe) 116 when each metal hollow rectangular pipe is connected.

[0084] <Example 8> In the eighth embodiment, a specific example 8 used hollow rectangular steel pipes 111 and 119 made of STKR400 according to JIS-G3466, with an outer diameter of 150 mm x 75 mm and a thickness of t=3.2 mm. Furthermore, flat T-shaped reinforcing plates 112 made of SS400 according to JIS-G3101 (rolled steel for general structural use), with a plate thickness of 6 mm, were welded to both long sides 111f and 119f. Meanwhile, the metal hollow rectangular pipe (beam pipe) 115 and the metal hollow rectangular pipe (column pipe) 116 were similarly made of STKR400 according to JIS-G3466, with an outer diameter of 200 mm x 100 mm and a thickness of t=6 mm. The spacing between the convex guide portions 112sa and 112ta of the T-shaped reinforcing plates 112 was set to 186 mm, allowing for a loose fit with the inner surfaces of the metal hollow rectangular pipes 115 and 116 at a gap of 2 mm.

[0085] (Ninth embodiment) Figures 23 and 24 show a metal T-shaped joint 120 according to the ninth embodiment of the present invention. First, the core material of the metal T-shaped joint 120 is formed when the lower mounting surface 121g of the hollow square steel pipe 121 and the end face of the hollow square steel pipe assembly 129 abut at approximately the center of the hollow square steel pipe 121 in the front-to-back (X-axis direction), perpendicular to each other, and the surrounding area (4 sides) is welded at the abutment point (see part 23(b)*) to form a T-shaped core material assembly 124. This hollow square steel pipe assembly 129 is welded so that two hollow square steel pipes 127 are connected by a hollow square steel pipe 128, for example, as in the sixth embodiment shown in Figures 15 to 17. Here, the width dimension (in the Y-axis direction) between the two sides 121f of the hollow rectangular steel pipe 121 and the width dimension (in the Y-axis direction) between the two sides 127f of the hollow rectangular steel pipe 127 are the same, and the sides 121f and 127f of the T-shaped core assembly 124 are on the same plane, and the area around the abutment (4 sides) is welded.

[0086] On the other hand, the T-shaped reinforcing plate 122, similar to the second embodiment shown in Figure 5, is formed by a flat plate with planar sections 122s and 122t, and its tip 122j is bent at a right angle from the planar section 122s. In addition, the outer surface of the T-shaped reinforcing plate 122 has multiple convex guide sections 122sa and 122ta formed in the same shape as the reinforcing plate 22 in Figure 5, which loosely fit and engage with the metal hollow rectangular pipe (beam pipe) 125 and the metal hollow rectangular pipe (column pipe) 126, which will be described later. The projection 122b is a cut-out projection for positioning the metal hollow rectangular pipe (beam pipe) 125 which is inserted from both sides.

[0087] The metal T-shaped joint 120 is formed by attaching and welding two T-shaped reinforcing plates 122 from the Y-axis direction (left and right) with the aforementioned T-shaped core assembly 124 in between. At this time, the two side surfaces 121f of the hollow square steel pipe 121 and the two side surfaces 127f of the hollow square steel pipe 127 are on the same plane and abut against the mounting surfaces 122sf and 122tf of the T-shaped reinforcing plates 122, respectively. Furthermore, the mounting surface 121g of the hollow square steel pipe 121 and the mounting surfaces 122g of the two T-shaped reinforcing plates 122 abut and are welded together. The welding points are as shown by the * marks in Figure 7 for the hollow square steel pipe 121 and in Figure 17 for the hollow square steel pipe assembly 129, and are completed by welding at multiple points.

[0088] Figure 24 shows a method for manufacturing a T-shaped hollow rectangular pipe assembly 320 by connecting metal hollow rectangular pipes (beam pipes) 125 in the X-axis direction on both sides and metal hollow rectangular pipes (column pipes) 126 in the downward Z-axis direction using a metal T-shaped joint 120. As shown in Figure 24, the metal hollow rectangular pipes (beam pipes) 125 are inserted from both ends of the metal T-shaped joint 120 and secured by tightening with hexagonal bolts 48 and nuts 19 from both sides in the Y-axis direction, but as shown in Figure 24, the abutment surface 125e of the metal hollow rectangular pipe (beam pipe) 125 abuts against the end surface of the projection 122b. The metal hollow rectangular pipe (column pipe) 126 is inserted from below the metal T-shaped joint 120 in the direction of the arrow, and its end surface 126d abuts against the convex guide portion 122sa at the base of the metal T-shaped joint 120 and secured by tightening with hexagonal bolts 48 and nuts 19. Furthermore, the notched relief portion 125h of the metal hollow rectangular pipe (beam pipe) 125 is the relief portion of the metal hollow rectangular pipe (column pipe) 126 when each metal hollow rectangular pipe is connected.

[0089] In the ninth embodiment, the T-shaped reinforcing plate 122 was manufactured by bending its tip portion 122j at a right angle from its flat portion 122s, but it may also be a flat T-shaped reinforcing plate as in the eighth embodiment. Furthermore, the T-shaped core assembly 124, which is provided perpendicular to the hollow square steel pipe 121, has a significantly increased cross-sectional shape compared to a single pipe as in the eighth embodiment, thereby greatly improving the second moment of area I. As will be described later, this is an effective means of improving the torsional strength against twisting (rotational moment T around the Z axis) of the tip portion when a column structure is manufactured using a metal T-shaped joint as shown in Figure 30.

[0090] <Example 9> In the 9th embodiment, a specific example 9 used a hollow square steel pipe 121 made of JIS-G3466 STKR400 with an outer diameter of 125mm x 125mm and a thickness of t=3.2mm. The T-shaped core assembly 124 was made by using two hollow square steel pipes 127 made of JIS-G3466 STKR400 with an outer diameter of 125mm x 75mm and a thickness of t=3.2mm, and welding a hollow square steel pipe 128 made of JIS-G3466 STKR400 with an outer diameter of 150mm x 75mm and a thickness of t=3.2mm between them. The T-shaped reinforcing plate 122 was made of JIS-G3101 (rolled steel for general structural use) SS400 with a plate thickness of 6mm and welded to both sides of the T-shaped core assembly 124. Meanwhile, the hollow rectangular metal tube (beam tube) 125 was similarly made of STKR400 according to JIS-G3466, with an outer diameter of 200mm x 150mm and a thickness of t=6mm, and the hollow rectangular metal tube (column tube) 126 was similarly made of STKR400 according to JIS-G3466, with an outer diameter of 350mm x 150mm and a thickness of t=6mm. The distance between the upper surface 122sh of the T-shaped reinforcing plate 122 and the convex guide portion 122sa was 186mm, and the distance between the convex guide portions 122ta was 336mm, allowing for a loose fit with a 2mm gap between the inner surfaces of the hollow rectangular metal tubes 125 and 126.

[0091] (Tenth embodiment) Figures 25 and 26 show a metal pi-shaped joint 130 according to the tenth embodiment of the present invention. First, the core material of the metal pi-shaped joint 130 is formed when the lower mounting surface 131sg of the hollow square steel pipe 131 and the end faces of the two hollow square steel pipes 139 meet perpendicularly and abut at a position approximately near the center (in the X-axis direction) of the hollow square steel pipe 131, at a distance Q from each other, and the surrounding area (4 sides) is welded at the abutment point (see Figure 25(b)*), forming a pi-shaped core material assembly 134. At this time, the hollow square steel pipe 131 and the two hollow square steel pipes 139 are hollow square steel pipes having the same cross-sectional shape, and the side surface 131sf and the side surface 139tf are on the same plane.

[0092] On the other hand, the pi-shaped reinforcing plate 132 is formed by a flat section 132s and two flat sections 132t, with the tip 132j ​​of the flat section 132s bent at a right angle. In addition, the two flat sections 132t are each partially bent at a right angle in opposite directions to form the upper surface 132th and the mounting surface 132tg. Furthermore, the outer surface of the pi-shaped reinforcing plate 132 has multiple convex guide sections 132sa and 132ta formed in the same shape as the reinforcing plate 22 in Figure 5, which loosely fit and engage with the metal hollow rectangular pipe (beam pipe) 135 and the metal hollow rectangular pipe (column pipe) 136, which will be described later. The projection 132b is a cut-out projection for positioning the metal hollow rectangular pipe (beam pipe) 135 which is inserted from both sides.

[0093] The metal pi-shaped joint 130 is formed by attaching and welding two pi-shaped reinforcing plates 132 from the Y-axis direction (left and right) with the aforementioned pi-shaped core assembly 134 in between. At this time, the side surfaces 131sf on both sides of the hollow square steel pipe 131 and the four side surfaces 139tf of the hollow square steel pipe 139 are on the same plane and abut against the mounting surfaces 132sf and two mounting surfaces 132tf of the pi-shaped reinforcing plates 132, respectively. Furthermore, the mounting surface 131sg of the hollow square steel pipe 131 and the mounting surface 132sg of the pi-shaped reinforcing plate 132, and the mounting surfaces 139tg of the two hollow square steel pipes 139 and the mounting surfaces 132tg of the pi-shaped reinforcing plates 132, respectively, abut and are welded together. The welding points are the same as in Figure 7 for the hollow square steel pipe 131, and the hollow square steel pipe 139 is also welded at multiple points as shown by the ★ marks in Figure 25, as in Figure 7. However, since the positioning of the weld between the Π-shaped reinforcing plate 132 and the hollow square steel pipe 139 becomes unstable, it is preferable to make the two flat sections 132t into flat plates as shown in Figure 21, which do not have bent mounting surfaces 132tg.

[0094] Figure 26 shows a method for manufacturing a pi-shaped hollow rectangular pipe assembly 330 by connecting metal hollow rectangular pipes (beam pipes) 135 on both sides and a metal hollow rectangular pipe (column pipe) 136 below using a metal pi-shaped joint 130. As shown in Figure 26, the metal hollow rectangular pipes (beam pipes) 135 are inserted from both ends of the metal pi-shaped joint 130 and secured by tightening with hexagonal bolts 18 and nuts 19 from both sides in the Y-axis direction, but as shown in Figure 26, the abutment surface 135e of the metal hollow rectangular pipe (beam pipe) 135 comes into contact with the end surface of the projection 132b. Furthermore, the two hollow rectangular metal pipes (column pipes) 136 are inserted from below the metal pi-shaped joint 130 in the direction of the arrow, and their end faces 136d come into contact with the convex guide portion 132sa at the base of the metal pi-shaped joint 130, and are secured by tightening with hexagonal bolts 18 and nuts 19. The notched relief portion 135h of the hollow rectangular metal pipe (beam pipe) 135 is the relief portion for the hollow rectangular metal pipe (column pipe) 136 when the individual hollow rectangular metal pipes are connected.

[0095] The metal pi-shaped joint 130 is composed of a pi-shaped core assembly 134 made of two hollow square steel pipes 139 that are spaced at a distance Q perpendicular to the hollow square steel pipe 131, and pi-shaped reinforcing plates 132 that reinforce it from both sides. As shown in Figure 32, which will be described later, when a column structure is made using the metal pi-shaped joint 130, the torsional force can be received by two axes spaced at a distance Q, compared to the metal T-shaped joint 120 of the ninth embodiment. Furthermore, the distance Q can be set arbitrarily, and the torsional strength against twisting at the tip (rotational moment T around the Z axis) can be further improved.

[0096] <Example 10> In the specific example 10 of the 10th embodiment, hollow rectangular steel pipes 131 and 139 were made of JIS-G3466 STKR400 with an outer diameter of 150 mm x 75 mm and a thickness of t=3.2 mm. The distance Q between the two hollow rectangular steel pipes 139 was set to 500 mm, and Π-shaped reinforcing plates 132, made of JIS-G3101 (rolled steel for general structures) SS400 with a plate thickness of 6 mm and bent into an L shape at the end, were welded to both sides 131sf and 139tf on the long side. Meanwhile, the metal hollow rectangular pipe (beam pipe) 135 and the metal hollow rectangular pipe (column pipe) 136 were similarly made of JIS-G3466 STKR400 with an outer diameter of 200 mm x 100 mm and a thickness of t=6 mm. Furthermore, the spacing between the upper surface 132sh and the convex guide portion 132sa of the Π-shaped reinforcing plate 132, and between the upper surface 132th and the convex guide portion 132ta, is set to 186 mm, allowing for loose fitting with the inner surfaces of the hollow rectangular metal tubes 135 and 136 at a distance of 2 mm.

[0097] As described above, the eighth to tenth embodiments describe a joint structure in which three types of shafts are perpendicular: a metal T-shaped joint 110, 120, and a metal Π-shaped joint 130. However, the cross-section of the shaft can be selected from various shapes shown in the first to seventh embodiments when connecting hollow rectangular metal pipes (beam pipes) in series, and the combinations are also free.

[0098] (11th embodiment) Figures 27 and 28 show a metal L-shaped joint 140 according to the 11th embodiment of the present invention. First, the core material of the metal L-shaped joint 140 is formed when the lower mounting surface 141sg of the hollow square steel pipe 141 and the end surface of the hollow square steel pipe 149 abut each other perpendicularly at a position near the front and rear (X-axis direction) ends of the hollow square steel pipe 141, and the surrounding area (4 sides) is welded at the abutment point (see Figure 27(b)*), forming an L-shaped core material assembly 144. At this time, the hollow square steel pipe 141 and the hollow square steel pipe 149 are hollow square steel pipes having the same cross-sectional shape, and the side surfaces 141sf and 149tf are on the same plane. Note that as long as the side surfaces 141sf and 149tf on both sides are on the same plane, they do not necessarily have the same cross-sectional shape, and the distance between the mounting surfaces 141sg and the distance between the mounting surfaces 149tg may be different. In other words, it can be arbitrarily selected to match the cross-sectional shape of the hollow rectangular metal pipe (beam pipe) 145 and the hollow rectangular metal pipe (column pipe) 146, which will be described later.

[0099] On the other hand, the L-shaped reinforcing plate 142 forms an L shape with flat sections 142s and 142t, and its external shape is similar to that of the reinforcing plate 12 of the metal joint 10, with multiple convex guide sections 142sa and 142ta provided on the flat sections 142s and 142t, and a projection 142b that protrudes in the width direction (Z-axis direction) is provided on the upper surface of the far end of the flat section 142s in the X-axis (front-to-back) direction.

[0100] The metal L-shaped joint 140 is constructed by attaching and welding two L-shaped reinforcing plates 142 from the Y-axis direction (left and right) on either side of the aforementioned L-shaped core assembly 144. The two L-shaped reinforcing plates 142 are welded to the L-shaped core assembly 144, with their mounting surfaces 142sf and 149tf respectively facing each other in the Y-axis direction (left and right). (In Figure 27, welds are indicated by * marks and multiple ★ marks in the figure.)

[0101] Figure 28 shows a method for manufacturing an L-shaped hollow rectangular pipe assembly 340 by connecting a metal hollow rectangular pipe (beam pipe) 145 horizontally (in the X-axis direction) and a metal hollow rectangular pipe (column pipe) 146 vertically (in the Z-axis direction) using a metal L-shaped joint 140. As shown in Figure 28, the metal hollow rectangular pipe (beam pipe) 145 and the metal hollow rectangular pipe (column pipe) 146 are inserted from both orthogonal ends of the metal L-shaped joint 140 in the direction of the arrows, and then tightened and fixed from both sides in the Y-axis direction with hexagonal bolts 18 and nuts 19. As shown in Figure 28, the abutment surface 145e of the metal hollow rectangular pipe (beam pipe) 145 abuts against the end face of the projection 142b, and the abutment surface 146e of the metal hollow rectangular pipe 146 abuts against the other end face of the projection 142b. At this time, the slanted end faces 145c and 146c are positioned with a small gap between them. In the description of the 11th embodiment, it was stated that the end faces of the hollow rectangular steel pipe 141 and the hollow rectangular steel pipe 149 are butt-welded perpendicularly to each other. However, it is also possible for the core material assembly to be butt-welded at a certain angle, such as 45 degrees, and for the metal joint to have an angle.

[0102] <Example 11> In the specific example 11 of the 11th embodiment, hollow rectangular steel pipes 141 and 149 have the same cross-sectional shape, and hollow rectangular steel pipes of JIS-G3466 STKR400 with an outer diameter of 150 mm x 75 mm and a thickness of t=3.2 mm were used. Flat L-shaped reinforcing plates 142 made of JIS-G3101 (rolled steel for general structures) SS400 with a plate thickness of 6 mm were welded to both sides 141sf and 149tf of the long side. On the other hand, metal hollow rectangular pipes (beam pipes) 145 and metal hollow rectangular pipes (column pipes) 146 similarly used JIS-G3466 STKR400 with an outer diameter of 200 mm x 100 mm and a thickness of t=6 mm. Furthermore, the spacing between the convex guide portions 142sa and 142ta of the L-shaped reinforcing plate 142 was set to 186 mm, allowing it to be loosely fitted with the inner surfaces of the hollow rectangular metal tubes 145 and 146 with a gap of 2 mm.

[0103] (12th embodiment) Figure 29 shows a metal L-shaped joint 150 according to the twelfth embodiment of the present invention. First, the core material of the metal L-shaped joint 150 is formed when the right side surface 151f of the hollow square steel pipe 151 and the end surface of the hollow square steel pipe 159 abut each other perpendicularly at a position near the front and rear (X-axis direction) ends of the hollow square steel pipe 151, and the surrounding area (4 sides) is welded at the abutment point (see Figure 29(b)*), forming an L-shaped core material assembly 154. At this time, the hollow square steel pipe 151 and the hollow square steel pipe 159 may be hollow square steel pipes having the same cross-sectional shape, and the distance between the side surfaces 151f and the distance between the side surfaces 159f may be different.

[0104] On the other hand, the L-shaped reinforcing plate 152 has its surface 152e bent inward at approximately its center, and the L-shaped reinforcing plate 153 has its mounting surface 153f bent inward at approximately its center. Multiple convex guide portions 152a and 153a are provided on the outer circumference of the L-shaped reinforcing plates 152 and 153, and a projection 153b that protrudes in the width direction (Z-axis direction) is provided on the upper surface of the bent portion of the L-shaped reinforcing plate 153. As shown in Figure 29(b), the bent portion of the L-shaped reinforcing plate 152 approximately coincides with the inner welded portion of the hollow square steel pipe 151 and the hollow square steel pipe 159, and the bent portion of the L-shaped reinforcing plate 153 approximately coincides with the outer end of the hollow square steel pipe 151.

[0105] The metal L-shaped joint 150 is constructed by attaching and welding bent L-shaped reinforcing plates 152 and 153 to the aforementioned L-shaped core assembly 154 from the X-axis direction (front and back) and the Y-axis direction (left and right), respectively. The right mounting surface 152f of the L-shaped reinforcing plate 152 and the right mounting surface 153f of the L-shaped reinforcing plate 153 abut against two opposing sides 151f of the L-shaped core assembly 154 in the Y-axis direction (left and right). Similarly, the left mounting surface 152f of the L-shaped reinforcing plate 152 and the left mounting surface 153f of the L-shaped reinforcing plate 153 abut against two opposing sides 159f in the X-axis direction (front and back), and are welded to the L-shaped core assembly 154. (Welding is indicated by * marks in Figure 29, where multiple ★ marks are shown in the figure.)

[0106] As described above, the first to seventh embodiments of the present invention describe a metal joint that connects two hollow rectangular metal pipes in series, the eighth and ninth embodiments describe a metal joint that connects two hollow rectangular metal pipes perpendicularly in a T-shape, the tenth embodiment describes a metal joint that connects three hollow rectangular metal pipes perpendicularly in a Π-shape, and the tenth and eleventh embodiments describe a metal joint that connects two hollow rectangular metal pipes perpendicularly in an L-shape. The present invention is not limited to these, however, and may also include, for example, a metal joint that connects four hollow rectangular metal pipes in a cross shape, or a metal joint that connects three hollow rectangular metal pipes perpendicularly from three axial directions (X, Y, and Z axes), or a metal joint in which three or more hollow rectangular steel pipes are butted perpendicularly from below (Z-axis direction) to a hollow rectangular steel pipe extending in the lateral direction (X-axis direction).

[0107] Furthermore, as mentioned above, when two hollow rectangular metal pipes are joined perpendicularly to each other in a T-shape, Π-shape, or L-shape, the hollow rectangular steel pipes constituting the core assembly do not necessarily need to have the same cross-sectional shape, as long as the mounting surfaces of the reinforcing plates are on the same plane, as in the metal T-shaped joint 120 of the ninth embodiment. Moreover, in the case of a metal L-shaped joint with a curved reinforcing plate, as in the twelfth embodiment, it is acceptable if butt welding of the hollow rectangular steel pipes is possible, even if one of the long side / short side of the hollow rectangular steel pipes is not on the same plane.

[0108] Hereafter, for reference, various embodiments of a support structure will be described in which hollow metal square pipes are joined using the metal joint of the present invention to create a support structure. Figures 30 and 31 show the case in which the first support structure 510 is made using the metal T-shaped joint 110 of the eighth embodiment. The support structure 510 consists of the metal T-shaped joint 110, two hollow metal square pipes (beam pipes) 515 inserted from the horizontal direction (X-axis direction) at both ends of the metal T-shaped joint 110, a hollow metal square pipe (column pipe) 516 with one end inserted from the vertical direction (Z-axis direction) of the metal T-shaped joint 110, and an RC foundation part with a shaft 514 provided at the other end of the hollow metal square pipe (column pipe) 516, and each connection is fastened and fixed from the Y-axis (left and right) direction with hexagonal bolts 18 and nuts 19.

[0109] Here, the relationship between the metal T-shaped joint 110 and the two metal hollow rectangular pipes (beam pipes) 515 and the metal hollow rectangular pipe (column pipe) 516 is the same as that of the T-shaped hollow rectangular pipe connector 310 described in Figure 22 of the eighth embodiment, so no further explanation is provided. On the other hand, the shaft-mounted RC foundation 514, as shown in Figure 31, consists of a shaft portion 519 in which reinforcing plates 512 are welded to both sides of a hollow rectangular steel pipe 511 in the Y-axis (left and right) direction, a plurality of studs (steel materials) 518 are provided protruding perpendicularly to the shaft portion from a part (lower part) of the shaft portion, and a concrete foundation portion 513 reinforced with reinforcing bars so as to conceal the studs (steel materials) 518.

[0110] The hollow rectangular steel pipe 511 of the shaft portion 519 is a steel pipe with the same cross-sectional shape as the hollow rectangular steel pipe 119 of the aforementioned metal T-shaped joint 110, and the reinforcing plate 512 also has the same shape as the flat portion 112t of the T-shaped reinforcing plate 112, with multiple convex guide portions 512ta provided near the tip of its outer circumference and near the foundation concrete portion 513. Here, the distance between the convex guide portions 512ta of the reinforcing plate 512 is the same as the distance between the convex guide portions 112ta of the T-shaped reinforcing plate 112 of the metal T-shaped joint 110. Furthermore, the welding of the hollow rectangular steel pipe 511 and the reinforcing plate 512 facing both sides is performed at multiple ★ points indicated by * marks in Figure 31. (Four directions of the hollow rectangular steel pipe 511)

[0111] As shown in Figure 31, the assembly of the support structure 510 begins by inserting the lower end of the hollow rectangular metal pipe (column pipe) 516 into the RC foundation 514 with a shaft. At this time, the distance between the convex guide portions 512ta and the distance between the surfaces 512e of the reinforcing plate 512 is approximately equal to the inner dimensions of the hollow rectangular metal pipe (column pipe) 516, allowing for a loose fit. In this state, the lower end of the hollow rectangular metal pipe (column pipe) 516 is fixed to the RC foundation 514 with a shaft by tightening with a hexagonal bolt 18 and a nut 19.

[0112] Next, the shaft portion of the metal T-shaped joint 110, which extends in the Z-axis (up and down) direction, is inserted into the upper end of the metal hollow rectangular pipe (column pipe) 516, and secured by tightening with a hexagonal bolt 18 and nut 19. Finally, the two metal hollow rectangular pipes (beam pipes) 515 are inserted from both ends of the shaft portion of the metal T-shaped joint 110, which extends in the X-axis (front and back) direction, and secured by tightening with a hexagonal bolt 18 and nut 19. Note that the order of assembly is not related and can be changed arbitrarily.

[0113] Here, as shown in Figure 30, a force is applied to the metal hollow rectangular pipe (beam pipe) 515 of the first support structure 510, generating a rotational moment T around the Z axis. In this case, it is necessary to improve the torsional strength of the metal hollow rectangular pipe (column pipe) 516, the shaft portion extending in the Z-axis (up and down) direction of the metal T-shaped joint 110, and the shaft portion 519 of the shaft-mounted RC foundation 514. In such cases, the polar moment of inertia IP of the shaft can be greatly improved by creating a core material assembly by combining hollow rectangular steel pipes, as in the hollow rectangular steel pipe assembly 129 of the metal T-shaped joint 120 described in the ninth embodiment of the present invention, and welding reinforcing plates to create the shaft portion.

[0114] Furthermore, as another means of improving torsional strength, other embodiments of the support structure will be described below. Figure 32 shows a second support structure 520, which consists of two metal hollow rectangular pipes (beam pipes) 525 inserted from the X-axis (front-to-back) direction using a metal pi-shaped joint 130, two metal hollow rectangular pipes (column pipes) 526 inserted from below the metal pi-shaped joint 130, and two shaft-mounted RC foundations 524 provided at the other ends of the metal hollow rectangular pipes (column pipes) 526.

[0115] In this second support structure 520, the tip of the pi-shaped reinforcing plate 132 of the metal pi-shaped joint 130 is bent into an L shape, and it is welded to the hollow square steel pipes 131 and 139 on three sides. Similarly, the two shafts 529 of the two shaft-attached RC foundation section 524 are composed of a hollow square steel pipe 521 and two reinforcing plates 522, and have a similar configuration. The shafts 529 have three surfaces in contact with the hollow square steel pipe 521, with the two reinforcing plates 522 surrounding it, and are welded at multiple ★ points indicated by the asterisks in Figure 33.

[0116] Here, the distance between the two shaft portions 529 is set to a distance that allows the hollow square metal pipe (column pipe) 526, which is attached to the metal pi-shaped joint 130, to be loosely fitted and installed. In other words, if the cross-sectional configuration of the shaft portion 529 is exactly the same as the cross-sectional configuration of the Z-axis (up and down) direction axis of the metal pi-shaped joint 130, then the distance between the opposing side walls of the opposing hollow square steel pipes 521 is the same as the distance between the inner sides of the two opposing hollow square steel pipes 139 of the metal pi-shaped joint 130, and is therefore distance Q.

[0117] Here, the two shaft portions 529 are loosely fitted and connected, with the distance between the upper surface 522h of the reinforcing plate 522 and the convex guide portion 522ta, and the distance between the surfaces 522e, being approximately the same as the inner diameter of the hollow rectangular metal tube (column tube) 526 that engages with them.

[0118] As yet another means of improving torsional strength, yet another embodiment of the support structure will be described below. The support structure in Figure 34 is an example of a third support structure 530 in which two metal T-shaped joints 160 are prepared and connected horizontally (in the X-axis direction) with a metal hollow rectangular connecting pipe 537, and two metal hollow rectangular pipes (beam pipes) 535 inserted from the X-axis (front and rear) direction are connected. Two sets of shaft-mounted RC foundations 514 are connected to the two vertical ends (in the Z-axis direction) of the metal T-shaped joints 160 with two metal hollow rectangular pipes (column pipes) 536.

[0119] The metal T-shaped joint 160 has, for example, the same cross-sectional shape as the metal T-shaped joint 110, and is a joint in which the length of the arm in the X-axis (front-rear) direction is different from the dimension U>V of the length of the arm as shown in Fig. 35(b). When the short-side (V-dimension side) of two metal T-shaped joints 160 is arranged facing each other and connected by a metal hollow square connecting pipe 537 between them, a joint assembly 539 similar to the metal Π-shaped joint 130 in Fig. 33 can be fabricated. The distance R between the axial centers of the two metal hollow square pipes (column pipes) 536 connected to this joint assembly 539 satisfies the relationship R≧2*V, and the distance R can be arbitrarily set within the range that satisfies the above formula. Here, the metal T-shaped joint 160 has an asymmetric left-right T-shape in consideration of the freedom of the arrangement position of the two sets of RC base parts 514 with shafts. Conversely, it may be different with U<V, or it may be a metal T-shaped joint 110 with the relationship U=V.

[0120] At the other ends of the two metal hollow square pipes (column pipes) 536 connected to the metal T-shaped joint 160, two independent sets of RC base parts 514 with shafts are respectively connected. That is, by using the metal T-shaped joint 160, the distance R between the two metal hollow square pipes (column pipes) 536 can be changed only by changing the metal hollow square connecting pipe 537, so that the positions of the two sets of RC base parts 514 with shafts can be freely set. Of course, it is obvious that if the distance R is increased, the torsional strength is improved because the two metal hollow square pipes (column pipes) 536 separated by the distance R receive the rotational moment (around the Z-axis) T.

[0121] The assembly of the support structure 530 is shown in Figures 35(a) to (d). First, two sets of RC foundations with shafts 514 are installed at positions corresponding to the distance R between two predetermined hollow square metal pipes (column pipes) 536, and the two hollow square metal pipes (column pipes) 536 are inserted from the direction of the arrow and fastened with hexagonal bolts 18 and nuts 19 (a). Next, the short sides (arms on the V side) of two metal T-shaped joints 160 are inserted into both ends of the hollow square metal connecting pipe 537 in the direction of the arrow and fastened with hexagonal bolts 18 and nuts 19 to assemble the joint assembly 539 (b). The two arms of the joint assembly 539 extending in the Z-axis direction are inserted into the upper ends of the two hollow square metal pipes (column pipes) 536 in the state of (a) from the direction of the arrow and fastened with hexagonal bolts 18 and nuts 19 (c). Finally, insert the two hollow metal square tubes (beam tubes) 535 into both ends of the joint assembly 539 in the X-axis (front-to-back) direction in the direction of the arrows and fasten them with hexagonal bolts 18 and nuts 19 (d). Note that the order of the assembly procedure can be changed as appropriate.

[0122] Having described the first to third support structures 510, 520, and 530 above, we will now describe a steel frame structure constructed by using multiple of these support structures and connecting their upper surfaces with multiple purlins.

[0123] Figure 36 shows a steel frame structure 1 made by preparing three sets of the aforementioned support structure 510 and connecting the upper ends of their metal hollow rectangular pipes (beam pipes) 515 with multiple purlins 570. First, three sets of shaft-mounted RC foundation sections 514 are embedded in the ground 2 so that the upper ends of the concrete protrude slightly. For each shaft-mounted RC foundation section 514, a metal hollow rectangular pipe (column pipe) 516, a metal T-shaped joint 110, and a metal hollow rectangular pipe (beam pipe) 515 are assembled and the three sets of support structure 510 are arranged in parallel. Multiple purlins 570 are connected so as to straddle the upper surface of the metal hollow rectangular pipe (beam pipe) 515 of the support structure 510 (the fastening method is not shown). Note that although three sets of support structure 510 are prepared in Figure 36, any number of sets, two or more, may be used.

[0124] Figure 38 shows an example of a carport assembled using this steel frame structure 1. A roof 3 is provided on the top surface of the main beam 570 of the steel frame structure 1, creating a carport that can accommodate two cars 4. The roof could be a corrugated metal roof or a solar power generation unit with multiple solar panels.

[0125] Figure 37 shows a steel frame structure 5 made up of three sets of support structures 561, 562, and 563 of different heights, with the upper ends of their metal hollow rectangular pipes (beam pipes) 515 connected by multiple purlins 571. In this way, by creating an inclination angle θ in the steel frame structure 5 using the support structures 561, 562, and 563, it can also be used as a mounting frame for a solar power generation system. Generally, due to latitude, an inclination angle of around 20-30° is efficient and commonly used for solar panels in Japan. By adjusting the height of these support structures 561, 562, and 563, the inclination angle θ can be freely set. Note that any number of support structures, as long as there are two or more sets, is acceptable.

[0126] Figure 39 shows a photograph of the actual prototype metal T-shaped joint 110, Figure 40 shows a photograph of the prototype steel structure 1 under construction, and Figure 41 shows a photograph of the completed prototype steel structure 1. Here, the cross-sectional shape of the metal T-shaped joint 110 is the same as the cross-sectional shape of the joint in the fifth embodiment of the present invention shown in Figures 13 and 14. The order of construction and assembly is arbitrary.

[0127] The metal joint of the present invention and the support structure and steel frame structure made using it have been described in detail above. The most distinctive feature of the metal joint of the present invention is that it is a metal joint for fastening multiple hollow rectangular pipes made of metal such as aluminum or steel, comprising a metal core material having opposing planes and a reinforcing material welded to the core material so as to cover at least two opposing surfaces of the outer surface of the core material. The reinforcing material is a reinforcing plate having a plurality of protrusions, the protrusions are provided protruding in the width direction of the reinforcing plate, the protrusions are loosely contained in the internal space of the hollow rectangular tubes, and the hollow rectangular tubes are connected to each other. It is characterized by the following.

[0128] As a result, even if standard hollow square metal pipes with dimensions specified in JIS are used for connection, metal joints that loosely fit into their inner diameters can be easily manufactured using hollow square steel pipes and reinforcing plates of similar dimensions specified in JIS. Furthermore, when using metal joints to manufacture support structures or steel frame structures, welding reinforcing plates to at least two opposing surfaces of the hollow square steel pipe in a direction perpendicular to the axis perpendicular to the ground (Z-axis in Figure 1) makes it possible to realize a lightweight metal joint with very large inert moment of area I and polar moment of area IP, and high bending and torsional strength. In addition, connecting hollow square metal pipes can be easily assembled using only metal joints and screw fastening, eliminating the need for welding or bonding on site and resulting in a metal joint with excellent workability.

[0129] Furthermore, with regard to support structures and steel structures manufactured using the metal joints of the present invention, all of the constituent elements—metal joints, hollow square metal pipes (beam pipes), hollow square metal pipes (column pipes), and RC foundations with shafts—can be manufactured in advance at the factory when manufacturing the steel structure. Moreover, as mentioned above, the connection of hollow square metal pipes can be easily assembled using only metal joints and screw fastening, eliminating the need for welding or bonding work at the site and shortening the installation period. As long as the metal joints can be manufactured in advance at the factory, the fixing of the metal core material and reinforcing material may be done not only by welding but also by bonding, screw fastening, or a combination thereof, but welding is preferable from the viewpoint of strength.

[0130] Furthermore, as mentioned above, the RC foundation section with a precast shaft made of reinforced concrete can be manufactured in advance at the factory, eliminating the need for foundation pouring (reinforcement formwork, concrete pouring, etc.) at the construction site, which has the effect of significantly shortening the construction period.

[0131] Although embodiments of the present invention and support structures and steel structures manufactured using the metal joints of the present invention have been described in detail above, the embodiments are not limited to these, and various other configurations can be taken without departing from the spirit of the present invention. [Explanation of symbols]

[0132] 1, 1, 5: Steel frame structure 2: Ground (ground surface) 3: Roof 4: car 10, 20, 30, 40, 50, 60, 70, 80, 90: Metal fittings 11, 41, 51, 76, 77, 81: Hollow rectangular steel pipes 11f, 41f, 51f, 77f, 81f: Side view 11g, 41g, 51g: Mounting surface 12, 22, 42, 52, 62, 72, 82, 92: Reinforcement plates 12a, 22a, 42a, 72a, 82a: Convex guide section 12e, 22e, 42e, 52e, 62e, 82e: Surface 12f, 22f, 42f, 52f, 62f, 72f, 82f, 92f: Mounting surface 22g, 42g, 52g, 62g, 92g: Mounting surface 82j, 82k: Cut-out projection 15, 25, 45, 55, 75, 85: Hollow rectangular metal pipes (beam pipes) 15a, 25a, 85a: Inner surfaces (top and bottom) of hollow rectangular metal tubes 15b, 25b, 85b: Inner surfaces (left and right) of hollow rectangular metal tubes 18, 48: Hex bolts 19: Nut 31:H-shaped steel 43, 47, 63: Auxiliary plates (spacers) 44, 64, 74: Core material assembly 49: Fixing screw 97: Reinforcement material 110, 120, 160: Metal T-shaped joint 111, 119, 121: Hollow rectangular steel pipe 111f, 119f, 121f: Side 111g, 121g: Mounting surface 112, 122: T-shaped reinforcing plate 112sa, 112ta, 122sa, 122ta: Convex guide section 112s, 112t, 122s, 122t: Flat part 112sf, 112tf, 122sf, 122tf: Mounting surface 122g: Mounting surface 114, 124: T-shaped core material assembly 115, 125, 135, 145: Hollow rectangular metal pipes (beam pipes) 116, 126, 136, 146: Hollow rectangular metal pipes (column pipes) 116d, 126d, 136d: End face 127, 128: Hollow rectangular steel pipe 127f: Side 129: Hollow rectangular steel pipe assembly 130: Metal Pi-shaped joint 131, 139: Hollow rectangular steel pipe 131sf, 139tf: Side view 131sg, 139tg: Mounting surface 132: Pi-shaped reinforcing plate 132sa, 132ta: Convex guide section 132s, 132t: Flat part 132sf, 132tf: Mounting surface 132sg, 132tg: Mounting surface 134: Pi-shaped core material assembly 140, 150: Metal L-shaped fittings 141, 149, 151, 159: Hollow rectangular steel pipes 141sf, 149tf, 151f, 159f: Side view 141sg, 149tg: Mounting surface 142, 152, 153: L-shaped reinforcement plate 142sa, 142ta, 152a, 153a: Convex guide section 142s, 142t: Flat part 142sf, 142tf, 152f, 153f: Mounting surface 144, 154: L-shaped core material assembly 210, 220, 270, 280, 310, 320, 330, 340: Hollow rectangular pipe connectors 510, 520, 530, 561, 562, 563: Support structure 511, 521: Hollow rectangular steel pipe 512, 522: Reinforcement plate 513: Foundation concrete section 514, 524: RC foundation with shaft 515, 525, 535: Hollow rectangular metal pipes (beam pipes) 516, 526, 536: Hollow rectangular metal pipes (column pipes) 537: Metal hollow rectangular connecting tube 539: Fitting Assembly 570, 571: Main house

Claims

1. A joint that fits into the internal space of a hollow rectangular metal pipe and connects two such hollow rectangular pipes together, A metal core material comprising at least one hollow rectangular steel pipe having a rectangular or square cross-section, A metal reinforcing material fixed to the core material so as to cover at least two opposing surfaces of the outer surface of the core material, A metal joint comprising a reinforcing plate having a plurality of protrusions, wherein the protrusions are provided projecting in the width direction of the reinforcing plate, and the protrusions are loosely fitted into the internal space of the hollow rectangular pipe, thereby connecting the hollow rectangular pipes together.

2. The metal joint, which is formed by fixing the reinforcing material to the core material, is fastened to the hollow rectangular metal pipe to be connected by screws, as described in claim 1.

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