KR20230009607A - Steel Tube for CFT and Manufacturing method thereof - Google Patents

Abstract

The present invention relates to a steel pipe structure for a CFT, which can be manufactured in a more robust structure, and to a manufacturing method thereof. The manufacturing method of the present invention comprises: a flat plate preparation step; a bending step; a diaphragm temporary fixing step; and a steel pipe structure forming step.

Description

Steel tube structure for CFT and its manufacturing method {Steel Tube for CFT and Manufacturing method thereof}

The present invention relates to a steel pipe structure for CFT and a method for manufacturing the same, and more specifically, to a simpler, more economical and superior quality steel pipe structure for CFT and a method for manufacturing the same.

Concrete Filled Steel Tube (hereinafter abbreviated as CFT) refers to a concrete filled steel tube filled with concrete in a round or square steel tube. . The CFT structure has the characteristics of enhancing the strength of members due to the restraint force of the external steel pipe surrounding the concrete core, and thus is different from the existing steel frame structure (S-structure), reinforced concrete structure (RC structure), and steel-reinforced concrete structure (SRC structure). This is a fourth structure that has recently been in the limelight. This CFT structure is a new structural system that has been developed recently. Relatively many studies have been conducted in the United States and Japan, etc., and it has been smoothly applied to the field.

In general, a concrete filled steel pipe is composed of a rectangular steel pipe and concrete filled therein.

The outer square steel pipe mainly resists the bending moment, and the inner filled concrete mainly resists the axial force. In addition, since the steel is placed at the outermost periphery, the utilization of the strength of the steel against bending and compression is maximized, the performance (strength and ductility) of the concrete is increased due to the lateral confinement effect of the steel, and the local buckling of the steel is reduced due to the internal concrete. Since the composite effect is maximized, such as increased stability, the CFT column becomes a very efficient column shape in terms of strength and ductility.

On the other hand, in order to increase the effect of combining the square steel pipe and concrete, a plurality of stud bolts, which are shear connectors, are installed in advance on the inner surface of the square steel pipe before filling the concrete.

In addition, the CFT column may cause out-of-plane deformation (local buckling) of the steel pipe or breakage of the weld due to the load and direction of the steel beam to which the steel beam is to be welded. CFT column-cheolgolbo connection requires high strength, rigidity, and deformability, so for this, a diaphragm is installed and reinforced at the junction between CFT column and cheolgolbo.

Diaphragm installation methods are usually divided into inner diaphragm, outer diaphragm, and through diaphragm.

Internal diaphragm is a method of inserting a diaphragm inside a steel pipe column and positioning it in contact with the flange of the steel beam. Although there is an advantage that the shear force of the cheolgolbo is directly transferred to the concrete as a pressure stress through the diaphragm, it is difficult to manufacture and the flange thickness of the cheolgolbo is relatively thick compared to the thickness of the steel pipe column due to the long span, etc. Excessive tensile stress may occur, and in particular, it is difficult to fill the lower part of the diaphragm tightly with concrete, and there is a disadvantage in that the concrete must be filled with pressure from the lower part.

The external diaphragm is a method in which the diaphragm is inserted into a steel pipe column and then interconnected through welding, and there are many protrusions, and thus, the transportation and work process are difficult. In particular, the shear force of the steel beam is transmitted only to the steel pipe column, and is indirectly transmitted to the concrete inside the steel pipe column through chemical adhesion, microcoupling force, friction, and bending effect, so the identification of the stress transmission mechanism is not clear.

The through diaphragm is a method in which the steel pipe is cut at the joint of the cheolgolbo and then directly welded to the flange of the cheolgolbo by penetrating the diaphragm. Although the stress transmission is clear, there is a disadvantage in that the number of man-hours for manufacturing and the amount of welding increases. In addition, the risk of fracture of the welded part increases due to the stress concentration phenomenon caused by the shape change at the joint surface of the flange and the diaphragm of the cheolgolbo.

Meanwhile, the currently used square steel pipe for CFT is a 4-seam plate rectangular steel pipe.

After preparing each of the four iron plates constituting one side of the column, these four iron plates are welded (that is, by welding the four corners of the square steel pipe) to produce a rectangular steel pipe.

In the case of the 4-Seam Plate rectangular steel pipe, welding is required at 4 places, so the welding amount is large, so the work takes a long time, and the possibility of welding defects is high, and the possibility of thermal deformation of the rectangular steel pipe is high.

In addition, all three conventional diaphragm methods are manufactured using a 4-seam plate rectangular steel pipe.

Republic of Korea Patent Registration No. 10-0918974 "Concrete Filled Steel Pipe Column and Manufacturing Method" (registered on September 18, 2009) Republic of Korea Patent Registration No. 10-2196491 "Method of manufacturing CFT column and CFT column produced by this method" (registered on December 22, 2020)

The present invention has been made to solve the problems of the prior art as described above, by minimizing the welded joint of the rectangular steel pipe, increasing productivity by reducing manufacturing cost and manufacturing period, as well as minimizing welding defects and creating a more robust structure. It is intended to provide a steel pipe structure for CFT that can be manufactured and a manufacturing method thereof.

In order to solve the above problems, the present invention provides a flat plate material preparation step of preparing a flat plate material including a plate-like metal plate in which a plurality of slits for fixing the diaphragm are formed; After the flat plate material preparation step, a bending step of bending the flat metal plate in the width direction to form a bent metal plate in which at least four or more unit metal plates extending flat in the longitudinal direction are bent and connected in the width direction; After the bending step, a first diaphragm plate extending in the longitudinal direction as a cross-sectional structure, and a flat plate provided at right angles to the first diaphragm plate on both sides in the longitudinal direction of the first diaphragm plate and having a central through hole (formed in the center) A diaphragm comprising a pair of second diaphragm plates of the shape and a coupling aid coupled to the first diaphragm plate and the second diaphragm plate such that outer edges of the first diaphragm plate and the second diaphragm plate protrude outward. is temporarily fixed to the bent metal plate, while the coupling aid of the diaphragm contacts the inner surface of the unit metal plate and the outer edge of the diaphragm is inserted into any one of the plurality of diaphragm fixing slits of the bendable metal plate A diaphragm temporary fixing step of temporarily fixing the diaphragm; After the shear connector coupling step, both ends of the bendable metal plate in the width direction are welded together to form a rectangular steel pipe, and the outer edge of the diaphragm is welded to the unit metal plate It is characterized in that it comprises a;

In the above, in the flat plate material preparation step, a plurality of fixing nuts are provided on the upper surface of the plate-like metal plate, and in the bending step, the plate-like metal plate is bent in a direction in which the plurality of fixing nuts are located inside, After the diaphragm temporary fixing step and before the rectangular steel pipe forming step, a shear connector coupling step of screwing a shear connector including a male thread into the female threaded hole of the fixing nut of the bent metal plate may be added.

In the above, the shear connection member may be any one of a bolt, a stud bolt, and a shape member.

In the above, a plurality of fixing holes are formed in the flat metal plate in the flat plate material preparation step, and after the diaphragm temporary fixing step and before the rectangular steel pipe forming step, shear connectors in the fixing holes of the bent metal plate A shear connector coupling step of inserting a portion of and welding-joining a portion of the shear connector to the bend-type metal plate from the outside of the bend-type metal plate to position the shear connector inside the bend-type metal plate may be added.

In the above, the plate-like metal plate has a plurality of diaphragm fixing grooves formed at both ends in the width direction, and in the step of forming the rectangular steel pipe, the unit metal plate disposed at one end of the bend-type metal plate in the width direction of the bend-type metal plate They may be welded to each other in a state of being disposed on the extension surface of the unit metal plate disposed at the other end in the width direction.

According to another idea of the present invention, in the steel pipe structure for CFT, both ends in the width direction of a bent metal plate in which at least four or more unit metal plates extending flat in the longitudinal direction and having a plurality of slits for fixing the diaphragm are bent in the width direction are connected to each other. Rectangular steel pipes joined by welding; A first diaphragm plate that has a cross-sectional structure and extends in the longitudinal direction, and is provided on both sides of the first diaphragm plate in the longitudinal direction at right angles to the first diaphragm plate and has a central through hole in the center. 2 diaphragm plates, and a coupling aid coupled to the first diaphragm plate and the second diaphragm plate so that outer edges of the first diaphragm plate and the second diaphragm plate protrude to the outside, wherein the coupling aid is the unit a diaphragm in which outer edges of the first diaphragm and the second diaphragm are inserted into a diaphragm-fixing slit of the unit metal plate and welded to the unit metal plate while contacting an inner surface of the metal plate; a plurality of fixing nuts fixed to the inner surface of the unit metal plate; a shear connector including a male threaded portion screwed into the female threaded hole of the fixing nut; It is characterized in that it includes.

In another aspect of the present invention, in the steel pipe structure for CFT, at least four unit metal plates extending flat in the longitudinal direction and having a plurality of diaphragm fixing slits and a plurality of fixing holes are bent and connected in the width direction. A rectangular steel pipe in which both end portions in the width direction of a metal plate are joined by welding to each other; A first diaphragm plate that has a cross-sectional structure and extends in the longitudinal direction, and is provided on both sides of the first diaphragm plate in the longitudinal direction at right angles to the first diaphragm plate and has a central through hole in the center. 2 diaphragm plates, and a coupling aid coupled to the first diaphragm plate and the second diaphragm plate so that outer edges of the first diaphragm plate and the second diaphragm plate protrude to the outside, wherein the coupling aid is the unit a diaphragm in which outer edges of the first diaphragm and the second diaphragm are inserted into a diaphragm-fixing slit of the unit metal plate and welded to the unit metal plate while contacting an inner surface of the metal plate; A plurality of shear connectors located inside the rectangular steel pipe and fixed to the rectangular steel pipe while a portion thereof is inserted into the fixing hole; It is characterized in that it includes.

In the above, it is preferable that the unit metal plates disposed at one end of the bendable metal plate in the width direction are welded to each other while being disposed on an extension surface of the unit metal plate disposed at the other end in the width direction of the bendable metal plate.

As described above, the present invention minimizes the welding joint of the rectangular steel pipe, thereby increasing productivity by reducing manufacturing cost and manufacturing period, as well as minimizing welding defects and manufacturing a steel pipe structure for CFT that can be manufactured in a more robust structure and manufacturing thereof provides a way

That is, manufacturing of the steel pipe structure for CFT is simplified, and welding defects are minimized by significantly reducing the welding joint of the rectangular steel pipe, and structural reliability can be improved with a more robust structure while minimizing welding stress.

Accordingly, the present invention can reduce the manufacturing cost and period of the steel pipe structure for CFT and increase productivity.

1 is a perspective view of a flat plate according to a first embodiment of the present invention;
2 is a cross-sectional view based on AA of FIG. 1;
3 is a cross-sectional view based on BB of FIG. 1;
4 is a front view of a bent plate material in a state of being bent after FIG. 1;
5 is a front view of a bent plate material in a state in which the diaphragm is temporarily fixed after FIG. 4;
6 is a front view of a bent plate member in a state in which the shear connector is coupled after FIG. 5;
Figure 7 is a perspective view of Figure 6;
8 is a front view of a state in which the steel pipe structure is completed as the bent metal plate is formed into a rectangular steel pipe after FIG. 6;
9 is a perspective view of the diaphragm of FIG. 5;
Figure 10 is a front view of Figure 9;
11 is a plan view of FIG. 9;
12 is a perspective view of a flat plate according to a second embodiment of the present invention;
13 is a conceptual cross-sectional view of a bent plate material in a bent state after FIG. 12;
14 is a front view of a bent plate member in a state in which the diaphragm is temporarily fixed after FIG. 13;
15 is a front view of a bent plate member in a state in which the shear connector is coupled after FIG. 14;
16 is a front view of a state in which the steel pipe structure is completed as the bent metal plate is formed into a rectangular steel pipe after FIG. 15;
17 is a conceptual diagram illustrating a phenomenon in which a stud bolt interferes with a mold when bending in a state in which a stud bolt is previously attached;

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

The present inventor intends to adopt a rectangular steel pipe for CFT having only one weld joint (seam) in order to minimize the weld joint.

However, as in the prior art, when a shear connector such as a stud bolt is pre-coupled to the flat metal plate before bending, the shear connector and the mold interfere with each other in the process of bending the flat metal plate as shown in FIG. I have a problem that I can't.

The present invention is proposed to solve this problem.

First, a first embodiment according to the present invention will be described.

1 is a perspective view of a flat plate according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view based on AA of FIG. 1, FIG. 3 is a cross-sectional view based on B-B of FIG. 1, and FIG. Figure 5 is a front view of the bent sheet material in a state in which the diaphragm is temporarily fixed after FIG. 4, Figure 6 is a front view of the bent sheet material in a state in which the shear connector is coupled after FIG. 7 is a perspective view of FIG. 6, FIG. 8 is a front view of a state in which the steel pipe structure is completed as the bent metal plate is formed into a rectangular steel pipe after FIG. 6, and FIG. 9 is a perspective view of the diaphragm of FIG. 5, and FIG. It is a front view, and FIG. 11 is a plan view of FIG.

This embodiment largely includes a flat plate preparation step -> bending step -> diaphragm temporary fixing step -> shear connector coupling step -> steel pipe structure forming step.

1. Flat plate preparation step

As shown in FIGS. 1 to 3 , a flat plate material 110 composed of a flat metal plate 111 and a fixing nut 112 is prepared.

A plurality of diaphragm fixing slits 111a, a plurality of diaphragm fixing grooves 111b, a plurality of bending markings 111c, and a plurality of groove welding improvement parts 111d are formed in the flat metal plate 111. .

The slit 111a for fixing the diaphragm is formed inside the flat metal plate 111, and is formed in an “I” shape in the present embodiment.

The grooves 111b for fixing the diaphragm are formed at both ends of the flat metal plate 111 in the width direction and are formed in a "[" shape. Combining the “[” shape of the pair of diaphragm fixing grooves 111b formed opposite each other in the width direction results in the same shape as the “I” shape of the diaphragm fixing slit 111a.

In addition, a bending marking 111c is displayed on the upper surface of the flat metal plate 111 in the form of a line extending in the longitudinal direction.

In this embodiment, four markings 111c for bending are displayed.

Marking for bending (111c) is displayed for the bending step to be described later.

In addition, the flat metal plate 111 has groove welding improvement portions 111d formed along both ends in the width direction thereof. The shape of the improved portion 111d for groove welding can be variously changed, which is formed for CO2 welding or SAW welding, which will be described later.

The fixing nut 112 is attached and fixed to the upper surface of the flat metal plate 111 by welding or the like.

A female screw hole is formed in the center of the fixing nut 112 .

The position where the fixing nut 112 is fixed is the position where the shear connector 123 described later will be installed.

That is, in this embodiment, before the bending step, instead of the shear connector 123, the fixing nut 112 is installed in advance.

2. Bending step

After the flat plate material preparation step, the flat plate material 110 is formed into a bent plate material 120 by bending the flat metal plate 111 of the flat plate material 110 as shown in FIG. 4 .

Specifically, the flat metal plate 111 is bent in the width direction by press forming to form the bent metal plate 121 . That is, in this embodiment, a press cold forming method is applied, and the bending is performed by pressing with a press along the bending marking 111c.

At this time, the number of bendable metal plates 121 is at least four (five in this embodiment, and depending on the embodiment, four, six, seven, eight, etc. may be applied) of unit metal plates 121a. ) is bent and connected in the width direction.

Each unit metal plate 121a extends flatly in the longitudinal direction, and each unit metal plate 121a is connected while being bent at an end of another adjacent unit metal plate 121a in the width direction.

In this way, when the flat metal plate 111 is bent in the width direction to form the bent metal plate 121, the fixing nut 112 is located inside the bent metal plate 121.

At this stage, the cross-sectional structure of the bendable metal plate 121 is not completely closed, but is partially open.

3. Diaphragm temporary fixing step

After the bending step, the diaphragm 122 is temporarily fixed to the diaphragm fixing slit 111a of the bendable metal plate 121 as shown in FIG. 5 .

Since the shear connector 123 is not yet installed, the diaphragm 122 can be installed.

The structure of the diaphragm 122 will be described with reference to FIGS. 9 to 11 .

The diaphragm 122 of this embodiment includes a first diaphragm plate 122a, a pair of second diaphragm plates 122b, and a coupling aid 122c.

The first diaphragm plate 122a has a cross-sectional structure and extends in the longitudinal direction.

The pair of second diaphragm plates 122b are provided at right angles to the first diaphragm plate 122a on both sides in the longitudinal direction of the first diaphragm plate 122a and have a central through hole 122b-1 formed in the center of the flat plate. It is a form.

The coupling aid 122c is coupled to the first diaphragm plate 122a and the second diaphragm plate 122b such that outer edges of the first diaphragm plate 122a and the second diaphragm plate 122b protrude outward.

The coupling aid (122c) is to adjust the installation interval when the diaphragm 122 is installed, and also to prevent melting from occurring during welding.

The outer edge of the diaphragm 122 having such a structure is inserted into any one of the plurality of diaphragm fixing slits 111a of the bendable metal plate 121, and at this time, the coupling aid 122c is the inner surface of the unit metal plate 121a. come into contact with

In this state, the outer edge of the diaphragm 122 may be tack welded to the bent metal plate 121 by CO2 welding.

4. Shear connector joining step

After the diaphragm temporary fixing step, as shown in FIG. 6, a shear connector 123 is coupled to the fixing nut 112 of the bent plate 120.

The shear connector 123 includes a male threaded portion screwed into the female threaded hole of the fixing nut 112, and the male threaded portion of the shear connector 123 is screwed into the female threaded hole of the fixed nut 112.

As a result, the shear connector 123 is located inside the bendable plate member 120 .

At this time, the shear connector 123 may be any one of a bolt, a stud bolt, and a shape member.

The shape material means a material having a shape other than bolts and stud bolts.

On the other hand, after the screw connection of the shear connector 123, a simple welding operation between the shear connector 123 and the fixing nut 112 may be additionally performed for a more robust coupling.

7 is a perspective view of the bent plate member 120 to which the diaphragm 122 and the shear connector 123 are coupled.

5. Steel pipe structure formation step

After the shear connector coupling step, as shown in FIG. 8, the bent metal plate 121 is pressed to form a square tube, and then both ends of the bendable metal plate 121 in the width direction are welded and combined, thereby a pair of diaphragms facing each other. The fixing groove 111b is formed as an “I” shaped slit, and the edge of the diaphragm 122 is inserted into the diaphragm fixing slit 111a and the diaphragm fixing groove 111b, and is used for fixing the diaphragm. An edge of the diaphragm 122 inserted into the slit 111a and the groove 111b for fixing the diaphragm is externally welded to the unit metal plate 121a.

As a result, the bendable metal plate 121 is formed as a rectangular steel pipe 131, and the diaphragm 122 is permanently coupled to the inside of the rectangular steel pipe 131, thereby completing the steel pipe structure 130.

In the case of this embodiment, a rectangular steel pipe 131, that is, a rectangular steel pipe 131 is formed.

The formation of the rectangular steel pipe 131 is performed by pressing the bendable metal plate 121 from the side and top to bring the parts to be welded into contact with each other while maintaining the shape of the rectangular steel pipe, and then tack welding (tag welding) to form the rectangular steel pipe After temporarily fixing the shape of , the welding joint 131a is formed by welding the welded part from the outside by Submerged Arc Welding (SAW) (or CO2 welding) method.

In addition, in a state where the bent metal plate 121 is pressed from the side and top to maintain the shape of a rectangular steel pipe, a pair of diaphragm fixing grooves 111b facing each other are formed as "I" shaped slits, and the diaphragm The edge of 122 is inserted into the diaphragm fixing slit 111a and the diaphragm fixing groove 111b, and in this state, the diaphragm inserted into the diaphragm fixing slit 111a and the diaphragm fixing groove 111b. The edge of 122 is temporarily fixed by tack welding (tag welding) to the unit metal plate 121a from the outside, and then submerged arc welding (SAW) (or CO2 welding) The edge of the diaphragm 122 is welded to the unit metal plate 121a by welding from the outside.

Meanwhile, in the present embodiment, the unit metal plate 121a-1 disposed at one end of the bendable metal plate 121 in the width direction is a unit metal plate 121a-2 disposed at the other end of the bendable metal plate 121 in the width direction. It is welded in a state disposed on the extension surface.

In such a rectangular steel pipe 131, only one welding joint 131a (welding seam) is formed.

In addition, the weld joint 131a is located at the center of the side of the rectangular steel pipe 131, where stress concentration is less, and thus the clarity and robustness of stress transmission are excellent.

Although the welding joint 131a may be formed at the corner of the rectangular steel pipe 131, which is vulnerable to brittleness, if the welding joint 131a is located at the center of the side of the rectangular steel pipe 131, it is very strong and has excellent rigidity.

Meanwhile, after forming the weld joint 131a, it is preferable to correct the shape of the rectangular steel pipe 131 using a press or a roll.

As a result, at least four or more unit metal plates 121a extending flat in the longitudinal direction are joined by welding both ends in the width direction of the bent metal plates 121 bent and connected in the width direction to each other. A rectangular steel pipe 131 and a unit metal plate 121a A plurality of fixing nuts 112 fixed to the inner surface of the fixing nut 112, a shear connector 123 including a male screw portion screwed into the female threaded hole of the fixing nut 112, a diaphragm whose edge is welded to the unit metal plate 121a ( A steel pipe structure 130 for CFT including 122 is manufactured.

On the other hand, according to the embodiment, after the melting prevention plate (molding supporting plate) is attached to one end of the width direction of the flat metal plate 111 in advance, welding is performed while being assisted by the melting prevention plate when forming the weld joint 131a You may.

A second embodiment of the present invention will be described.

12 is a perspective view of a flat plate material according to a second embodiment of the present invention, FIG. 13 is a conceptual cross-sectional view of a bent plate material in a bent state after FIG. 12, and FIG. 14 is a state in which the diaphragm is temporarily fixed after FIG. 13 15 is a front view of the bent plate material in a state in which the shear connector is coupled after FIG. 14, and FIG. 16 is a state in which the steel pipe structure is completed as the bent metal plate is formed into a rectangular steel pipe after FIG. 15 17 is a conceptual diagram illustrating a phenomenon in which a stud bolt interferes with a mold during bending in a state in which a stud bolt is previously attached.

1. Flat plate preparation step

As shown in FIG. 12, a flat plate material 110 made of a flat metal plate 111 is prepared.

In the flat metal plate 111, as in the first embodiment, a plurality of diaphragm fixing slits 111a, a plurality of diaphragm fixing grooves 111b, a plurality of bending markings 111c, and a plurality of groove welding grooves. A portion 111d is formed.

In this embodiment, a plurality of fixing holes 111e are formed in the flat metal plate 111 instead of fixing nuts.

2. Bending step

After the flat plate material preparation step, the flat plate material 110 is formed into a bent plate material 120 by bending the flat metal plate 111 of the flat plate material 110 as shown in FIG. 13 .

Specifically, the flat metal plate 111 is bent in the width direction to form a bent metal plate 121 .

This is substantially the same as the first embodiment.

3. Diaphragm temporary fixing step

After the bending step, the diaphragm 122 is temporarily fixed to the diaphragm fixing slit 111a of the bendable metal plate 121 as shown in FIG. 14 .

This is substantially the same as the first embodiment.

4. Shear connector bonding step

After the diaphragm temporary fixing step, as shown in FIG. 15, a shear connector 123 is coupled to the fixing hole 111e of the bendable plate 120.

Specifically, after positioning the shear connector 123 inside the bendable metal plate 121, a portion of the shear connector 123 is inserted into the fixing hole 111e of the bendable metal plate 121, and the bendable metal plate ( A part of the shear connector 123 is welded to the bent metal plate 121 from the outside of 121).

As a result, the shear connector 123 is coupled to the bendable plate member 120 while being positioned inside the bendable plate member 120 .

5. Steel pipe structure formation step

After the shear connector coupling step, as shown in FIG. 16, both ends in the width direction of the bendable metal plate 121 are welded and coupled to each other, whereby a pair of diaphragm fixing grooves 111b facing each other are formed with an “I” shaped slit. , and the edge of the diaphragm 122 is inserted into the diaphragm fixing slit 111a and the diaphragm fixing groove 111b, and is inserted into the diaphragm fixing slit 111a and the diaphragm fixing groove 111b. The edge of the diaphragm 122 is welded to the unit metal plate 121a from the outside.

This is substantially the same as the first embodiment.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention. do.

110: flat plate
111: flat metal plate
111a: slit for fixing diaphragm 111b: groove for fixing diaphragm
111c: Marking for bending 111d: Improvement for groove welding
111e: fixing hole
112: fixing nut
120: bent plate
121: bendable metal plate 121a: unit metal plate
122: diaphragm 122a: first diaphragm plate
122b: second diaphragm plate 122b-1: central through-hole
122c: Combined Auxiliary
123: shear connector
130: steel pipe structure
131: rectangular steel pipe
131a: welding joint

Claims (8)

A flat plate material preparation step of preparing a flat plate material including a flat plate type metal plate in which a plurality of slits for fixing the diaphragm are formed;
After the flat plate material preparation step, a bending step of bending the flat metal plate in the width direction to form a bent metal plate in which at least four or more unit metal plates extending flat in the longitudinal direction are bent and connected in the width direction;
After the bending step,
A first diaphragm plate extending in the longitudinal direction as a cross-sectional structure, provided at right angles to the first diaphragm plate on both sides in the longitudinal direction of the first diaphragm plate, and a central through hole (a pair of flat plates formed) A diaphragm including a second diaphragm plate and a coupling aid coupled to the first diaphragm plate and the second diaphragm plate so that outer edges of the first and second diaphragm plates protrude outwardly, and the bendable metal plate includes a diaphragm. Temporarily fixed to
Diaphragm temporary fixing for temporarily fixing the diaphragm by allowing the outer edge of the diaphragm to be inserted into any one of a plurality of diaphragm fixing slits of the bendable metal plate while the coupling aid of the diaphragm contacts the inner surface of the unit metal plate step ;
After the shear coupling member coupling step, forming a rectangular steel pipe by welding both end portions of the bendable metal plate in the width direction to each other, and welding an outer edge of the diaphragm to the unit metal plate;
A method for manufacturing a steel pipe structure for CFT, characterized in that it comprises a.
According to claim 1,
In the flat plate preparation step, a plurality of fixing nuts are provided on the upper surface of the flat metal plate,
In the bending step, the flat metal plate is bent in a direction in which the plurality of fixing nuts are located inside,
After the diaphragm temporary fixing step and before the rectangular steel pipe forming step, a shear connector coupling step of screwing a shear connector including a male thread into the female threaded hole of the fixing nut of the bent metal plate is added
Method for manufacturing a steel pipe structure for CFT, characterized in that.
According to claim 2,
The shear connecting member is a method for manufacturing a steel pipe structure for CFT, characterized in that any one of bolts, stud bolts, and shape members.
According to claim 1,
In the flat plate preparation step, a plurality of fixing holes are formed in the flat metal plate,
After the diaphragm temporary fixing step and before the rectangular steel pipe forming step, insert a portion of the shear connector into the fixing hole of the bendable metal plate and weld a portion of the shear connector to the bendable metal plate from the outside of the bendable metal plate Adding a shear connector coupling step of positioning the shear connector inside the bent metal plate by
Method for manufacturing a steel pipe structure for CFT, characterized in that.
According to any one of claims 1 to 4,
The flat metal plate has a plurality of diaphragm fixing grooves formed at both ends in the width direction,
In the step of forming the rectangular steel pipe, the unit metal plates disposed at one end of the bendable metal plate in the width direction are welded to each other while being disposed on the extension surface of the unit metal plate disposed at the other end in the width direction of the bendable metal plate.
Method for manufacturing a steel pipe structure for CFT, characterized in that.
A rectangular steel pipe in which at least four unit metal plates extending flat in the longitudinal direction and formed with a plurality of slits for fixing a diaphragm are joined by welding both ends in the width direction of bent metal plates connected by bending in the width direction;
A first diaphragm plate that has a cross-sectional structure and extends in the longitudinal direction, and is provided on both sides of the first diaphragm plate in the longitudinal direction at right angles to the first diaphragm plate and has a central through hole in the center. 2 diaphragm plates, and coupling aids coupled to the first diaphragm plate and the second diaphragm plate so that outer edges of the first and second diaphragm plates protrude outward,
a diaphragm in which outer edges of the first diaphragm and the second diaphragm are inserted into a diaphragm-fixing slit of the unit metal plate and welded to the unit metal plate while the coupling support is in contact with an inner surface of the unit metal plate;
a plurality of fixing nuts fixed to the inner surface of the unit metal plate;
a shear connector including a male threaded portion screwed into the female threaded hole of the fixing nut;
Steel pipe structure for CFT, characterized in that it comprises a.
A rectangular steel pipe in which at least four or more unit metal plates having a plurality of diaphragm fixing slits and a plurality of fixing holes extending flat in the longitudinal direction are connected by bending in the width direction are joined by welding both ends in the width direction to each other;
A first diaphragm plate that has a cross-sectional structure and extends in the longitudinal direction, and is provided on both sides of the first diaphragm plate in the longitudinal direction at right angles to the first diaphragm plate and has a central through hole in the center. 2 diaphragm plates, and coupling aids coupled to the first diaphragm plate and the second diaphragm plate so that outer edges of the first and second diaphragm plates protrude outward,
a diaphragm in which outer edges of the first diaphragm and the second diaphragm are inserted into a diaphragm-fixing slit of the unit metal plate and welded to the unit metal plate while the coupling support is in contact with an inner surface of the unit metal plate;
A plurality of shear connectors located inside the rectangular steel pipe and fixed to the rectangular steel pipe while a portion thereof is inserted into the fixing hole;
Steel pipe structure for CFT, characterized in that it comprises a.
According to claim 6 or 7,
A steel pipe structure for CFT, characterized in that the unit metal plates disposed at one end of the bendable metal plate in the width direction are welded to each other while being disposed on an extension surface of the unit metal plate disposed at the other end in the width direction of the bendable metal plate.

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