Joint structure for channel steel, frame member, panel member and method for manufacturing joint structure of channel steel

Abstract

To provide channel steel, a joint structure for channel steel, a frame member, a panel member, a method for manufacturing channel steel, and a method for manufacturing a joint structure for channel steel, which can achieve both a reduction in cross-sectional dimensions and the ensuring of bending resistance while suppressing the burden of joint work.SOLUTION: Channel steel 10 is a long channel steel formed from a single steel plate and having a web 12 and a pair of flanges 14. At least one flange 14 comprises: a strip-shaped base portion 14A continuous with the web 12; a folded portion 14B located at an end of the base portion 14A opposite to the web 12; and a strip-shaped outer layer portion 14C disposed on an outer surface side of the base portion 14A in portions excluding an end in a longitudinal direction L of the flange 14, the outer layer portion 14C extending from the folded portion 14B toward the web 12 alongside the base portion 14A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a channel steel, a channel steel joint structure, a frame member, a panel member, a channel steel manufacturing method, and a channel steel joint structure manufacturing method. [Background technology]

[0002] Conventionally, panel members that integrate steel frame members, interior / exterior facing materials, and functional materials such as thermal insulation materials have been known as building materials. Panel members are, for example, building materials such as roofing materials and wall facing materials. As the steel frame members used for panel members, long channel steel having a C-shaped cross section and including a web and a pair of flanges is often used.

[0003] Specifically, a frame member can be manufactured by, for example, integrating multiple channel steel beams as vertically extending longitudinal members and multiple channel steel beams as horizontally extending transverse members in a mutually intersecting state at a manufacturing factory by welding, screwing, or the like. Furthermore, a panel member can be constructed by joining components such as interior and exterior facing materials or functional materials to the plate surfaces of the flanges of the channel steel beams of the integrated frame member. The manufactured panel member can be transported to the construction site of the building and attached to the building's framework at the construction site.

[0004] Here, since the dimensions of panel members or frame members are relatively large, there is a need to reduce the burden of on-site work at construction sites where installation work is performed. Furthermore, particularly in the construction field, the decline and aging of skilled workers is becoming a problem. For this reason, there is a need to reduce the cross-sectional dimensions of the channel steel that makes up the frame members in order to further reduce the burden of on-site work regarding the handling of panel members or frame members.

[0005] The cross-sectional dimensions of a channel steel can be reduced by shortening at least one of the web height and flange width. However, as the cross-sectional dimensions become smaller, the bending resistance of the channel steel decreases. In other words, it is not easy to achieve both a reduction in the cross-sectional dimensions and sufficient bending resistance. In this specification, "bending resistance" refers to the performance of a member, including its rigidity and strength against bending.

[0006] With regard to reducing the cross-sectional dimensions and ensuring bending resistance, for example, Prior Art Document 1 discloses a light-gauge channel steel in which the flange is overlapped two or more times by performing a hemming and folding process on the end of the flange opposite the web. In Prior Art Document 1, the folded-back portion of the flange is overlapped on the inner surface of the portion of the flange that is continuous with the web. The technology in Prior Art Document 1 makes it possible to partially increase the cross-sectional area of ​​only the flange portion, excluding the web portion, and therefore is said to be able to obtain a light-gauge channel steel with greater cross-sectional performance, such as a moment of inertia, compared to a light-gauge channel steel with the same outer diameter.

[0007] Prior Art Document 2 also discloses a channel steel as a structural steel material in which the end of the flange opposite the web is folded back onto the outer surface of the part of the flange that continues to the web, making the flange twice as thick as the web. The part of the folded flange that continues to the web and the folded back part are joined by welding.

[0008] In Prior Art Document 2, the total plate thickness of the flange is the (number of folds + 1) times the plate thickness of the web. For example, if there is one fold, the total plate thickness of the flange is twice the plate thickness of the web. According to the technology in Prior Art Document 2, by overlapping the flange plates twice, a flange that is thicker than the web can be manufactured from a single steel plate without requiring two types of steel plate, and it is said that this prevents an increase in the number of processing steps and makes it possible to manufacture structural members such as columns or beams economically. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 5382798 [Patent Document 2] Japanese Patent Application Publication No. 2-296952 Summary of the Invention [Problem to be solved by the invention]

[0010] However, in Prior Art Document 1, in order to align and join the outer surface of the flange of the light channel steel with the outer surface of the flange at the center of the channel steel that is arranged orthogonally to the light channel steel, it is necessary to narrow the end of the orthogonally arranged channel steel from the center by the thickness of the inner layer of the double flange of the light channel steel. As a result, additional work such as drawing is required for the end of the channel steel of the orthogonally arranged member.

[0011] Furthermore, for example, when the flanges of a light-gauge channel steel are doubled by hemming, if the hemming accuracy is low, there is a risk of bulging at the boundary of the folded flange when thick plates or high-strength steel plates with large springback are used. Alternatively, there is a risk of gaps forming between the plate portions of the folded flange. This can result in a step between the flange surfaces of the light-gauge channel steel and the member positioned perpendicular to the light-gauge channel steel at the joint, resulting in a risk of the flange surfaces not being aligned. Therefore, after the hemming operation, additional readjustment work, such as surface processing, is required.

[0012] Furthermore, in the case of the channel steel in Prior Art Document 2, the folding process is performed over the entire length, so the total plate thickness of the flange is increased over the entire length. Therefore, when joining other structural members to the folded portion of the flange, a large pressure must be applied when inserting the joining portion to compensate for the increased thickness. As a result, the joining work becomes more difficult. Furthermore, Prior Art Document 2 also requires the burden of welding the portion of the overlapping flange that continues to the web and the folded portion to manufacture structural members with relatively high strength, such as columns or beams.

[0013] In view of the above problems, the present disclosure aims to provide a channel steel, a channel steel joining structure, a frame member, a panel member, a method for manufacturing a channel steel, and a method for manufacturing a channel steel joining structure, which can reduce the burden of joining work while achieving both a reduction in cross-sectional dimensions and ensuring bending resistance. [Means for solving the problem]

[0014] The channel steel according to the first aspect of the present disclosure is a long channel steel formed from a single steel plate and having a web and a pair of flanges, and at least one of the flanges has a band-shaped base portion continuous with the web, a folded portion located at the end of the base opposite the web, and a band-shaped outer layer portion located on the outer surface side of the base in a portion excluding the longitudinal end of the flange, and extending from the folded portion toward the web alongside the base.

[0015] In the channel steel according to the first aspect, the longitudinal end of the flange has no outer layer disposed on the outer surface of the base, exposing the outer surface of the base. The longitudinal end of the flange functions as a joint with another structural member. For example, by preparing another channel steel and joining the flange of the prepared channel steel to the outer surface of the base at its end, a joined structure in which two channel steels are joined can be obtained. In other words, since the flange plate thickness is not increased at the end where the joint is formed in the joined structure, the burden of the joining work can be reduced compared to when, for example, a portion of the flange is folded over to increase the plate thickness at the end where the joint is formed.

[0016] In the first embodiment, in the portion of the flange excluding the longitudinal end portion, the outer layer portion, which is the portion folded back toward the web side, is arranged on the outer surface side of the base in a state extending side by side. Therefore, the thickness of the portion of the channel steel excluding the end portion having the outer layer portion is thicker than the thickness of the end portion not having the outer layer portion. For example, when the channel steel is formed from a single steel plate with a substantially uniform thickness, the thickness of the flange in the portion excluding the end portion having the outer layer portion can be increased to twice the thickness of the flange at the end portion consisting only of the base portion.

[0017] In other words, in the portion of the channel steel excluding the ends, the steel material is concentrated at the flange position, which is the outer edge of the cross section and is effective in improving bending resistance. Therefore, even if the cross section dimension is reduced, the bending resistance per unit weight can be strengthened compared to that of channel steel without an outer layer portion. In other words, the bending resistance can be reinforced by the outer layer portion of the portion excluding the ends so that the bending resistance does not decrease due to the reduction in the cross section dimension.

[0018] Therefore, according to the channel steel of the first aspect, it is possible to provide a channel steel that can achieve both a smaller cross-sectional dimension and sufficient bending resistance while reducing the burden of joining work.

[0019] In addition, the joining structure of a channel steel according to a second aspect of the present disclosure is a joining structure in which a long-length first channel steel formed from a single steel plate and having a web and a pair of flanges, and a long-length second channel steel formed from a separate steel plate and having a web and a pair of flanges, are joined with their longitudinal directions perpendicular to each other, and the pair of flanges of the first channel steel have a band-shaped base portion continuous with the web, a folded portion located at the end of the base opposite the web, and a band-shaped outer layer portion arranged on the outer surface of the base in a portion excluding the longitudinal ends of the flanges, and extending from the folded portion toward the web alongside the base, and the pair of flanges of the second channel steel are joined onto the outer surfaces of the respective bases at the longitudinal ends of the pair of flanges of the first channel steel.

[0020] In the joining structure of the channel steel of the second aspect, a first channel steel configured in the same manner as the channel steel of the first aspect is joined to a second channel steel, thereby providing a joining structure that can reduce the burden of joining work while achieving both a reduced cross-sectional dimension and ensuring bending resistance.

[0021] A frame member according to a third aspect of the present disclosure comprises a set of vertical members arranged parallel to each other with a gap therebetween, each vertical member being formed from a single steel plate and including a long first channel steel having a web and a pair of flanges, and a set of horizontal members being formed from a separate steel plate and including a long second channel steel having a web and a pair of flanges, each horizontal member being joined at one end and the other end of the set of vertical members with their longitudinal direction perpendicular to the longitudinal direction of the vertical members, and at least one of the joints between the vertical members and the horizontal members forms a channel steel joint structure according to the second aspect.

[0022] The frame member according to the third aspect, like the first aspect, includes a joining structure in which a first channel steel is joined to a second channel steel, which can achieve both a reduction in cross-sectional size and ensuring bending resistance while reducing the burden of joining work. Therefore, in the third aspect, it is possible to achieve both a reduction in the cross-sectional size of the frame member itself and ensuring bending resistance.

[0023] A panel member according to a fourth aspect of the present disclosure comprises the frame member according to the third aspect and a face material provided on the frame member.

[0024] The panel member according to the fourth aspect, like the first aspect, includes a frame member in which a first channel steel is joined to a second channel steel, which allows for both a reduced cross-sectional size and sufficient bending resistance while reducing the burden of joining work. Therefore, in the fourth aspect, it is possible to reduce the cross-sectional size of the panel member itself while ensuring sufficient bending resistance. Furthermore, since the frame member is made smaller and lighter, it is easier to add components other than the frame member to the panel member. This allows for diversification of the functions of the surface material. Furthermore, it is possible to improve the transportation efficiency of the panel member, i.e., improve logistics, and improve the on-site workability of the panel member.

[0025] A manufacturing method of a channel steel according to a fifth aspect of the present disclosure is a manufacturing method of a long channel steel having a web and a pair of flanges, in which, in a steel plate having a planned web region that forms the web and planned flange regions that form the pair of flanges, at least one of the planned flange regions is divided into a band-shaped planned base region that is continuous with the planned web region and a band-shaped planned outer layer region that is located on the opposite side of the planned base region from the planned web region, and an end portion in the longitudinal direction of the planned outer layer region of the steel plate is removed. a step of folding the outer layer intended region toward the web intended region, thereby arranging the folded outer layer intended region as an outer layer above the base intended region, and forming the base intended region with the outer layer disposed above as a base; and a step of folding the base opposite the outer layer portion so as to be perpendicular to the web intended region, thereby forming the web intended region as the web of the channel steel, and forming the base and the outer layer portion as the flange of the channel steel.

[0026] In the manufacturing method of channel steel according to the fifth aspect, as in the first aspect, it is possible to manufacture channel steel that can achieve both a reduced cross-sectional dimension and sufficient bending resistance while reducing the burden of joining work.

[0027] In the fifth aspect, when a bending moment caused by an external force in the out-of-plane direction is received by the channel steel, the base and outer layer are in close contact with each other throughout. This close contact allows the base and outer layer to resist the bending moment while mutually constraining each other in the out-of-plane direction in the entire region where the bending moment occurs, i.e., the entire region in the flange where compressive stress and tensile stress are distributed along the material axis, thereby suppressing buckling due to the compressive stress. Furthermore, in the flange, the outer layer is partially compressed as a result of the direct action of the external force in the out-of-plane direction itself. This compressed portion is subjected to the action of an external force, further locally enhancing the mutual constraint between the base and outer layer caused by the action of the bending moment. As a result, the effect of mutual constraint on buckling is enhanced, eliminating the need to previously integrate the base and outer layer by welding or other means.

[0028] A manufacturing method for a channel steel joint structure relating to the sixth aspect of the present disclosure is a manufacturing method for a channel steel joint structure in which a long-length first channel steel formed from a single steel plate and having a web and a pair of flanges, and a long-length second channel steel formed from a separate steel plate and having a web and a pair of flanges, are joined with their longitudinal directions perpendicular to each other, and the pair of flanges of the second channel steel are respectively joined onto the outer surfaces of the bases of the pair of flanges of the first channel steel manufactured using the channel steel manufacturing method relating to the fifth aspect.

[0029] In the manufacturing method for a channel steel joint structure according to the sixth aspect, as in the second aspect, a channel steel joint structure can be realized that can reduce the burden of joining work while achieving both a reduced cross-sectional dimension and sufficient bending resistance. [Effects of the Invention]

[0030] According to the present disclosure, it is possible to provide channel steel, channel steel joining structures, frame members, panel members, methods for manufacturing channel steel, and methods for manufacturing channel steel joining structures, which can reduce the burden of joining work while achieving both a reduction in cross-sectional dimensions and ensuring bending resistance. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view illustrating a channel steel according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a side view of the channel steel according to the present embodiment as viewed along the longitudinal direction. [Figure 3] FIG. 3(A) is a side view of a channel steel having an outer layer portion according to a first modified example, and FIG. 3(B) is a side view of a channel steel having an outer layer portion according to a second modified example. [Figure 4] FIG. 4(A) is a side view of a channel steel having an outer layer portion according to a third modified example, and FIG. 4(B) is a side view of a channel steel having an outer layer portion according to a fourth modified example. [Figure 5] FIG. 10 is a side view of a channel steel having an outer layer portion according to a fifth modified example. [Figure 6] FIG. 1 is a diagram (part 1) illustrating a method for manufacturing a channel steel according to the present embodiment, showing the plate surface of a steel plate, which is the raw material for the channel steel, from the front. [Figure 7] FIG. 2 is a side view (part 2) illustrating the manufacturing method of the channel steel according to the present embodiment. [Figure 8] FIG. 10 is a front view illustrating a frame member in which the channel steel according to this embodiment is used as a first channel steel. [Figure 9] 9 is an enlarged view of one corner portion of the frame member in FIG. 8 in which the joining structure of the channel steel according to the present embodiment is formed. [Figure 10] 9 is a diagram illustrating one corner portion of the frame member in FIG. 8, with the plate surface of the web of the first channel steel viewed from the front. FIG. [Figure 11] 11 is a cross-sectional view taken along line 11-11 in FIG. 9. [Figure 12] 12 is a cross-sectional view of a panel member according to the present embodiment, in which a face material is provided on a frame member, cut at the same position as the cross-sectional view of FIG. 11. FIG. [Figure 13] FIG. 2 is a perspective view illustrating a manufacturing method of a channel steel joining structure according to the present embodiment. [Figure 14]Figure 14(A) is a side view illustrating the channel steel of this embodiment when it is bent from the plate surface side of the flange along the plate surface of the web, and Figure 14(B) is a side view that schematically illustrates the behavior of the channel steel of this embodiment when it is bent. [Figure 15] Figure 15(A) is a side view illustrating a channel steel according to a comparative example when it is bent from the plate surface side of the flange along the plate surface of the web, and Figure 15(B) is a side view that schematically illustrates the behavior of the channel steel according to a comparative example when it is bent. [Figure 16] 12 is a cross-sectional view of a frame member according to a first comparative example taken at the same position as the cross-sectional view of FIG. 11. FIG. [Figure 17] This is a diagram illustrating the method of the constant bending test performed using the channel steel of this embodiment, showing the plate surface of the web of the channel steel of a test specimen having a test section where constant bending is performed and a stiffened portion outside the test section, viewed from the front. [Figure 18] This is a photograph of a channel steel in which local buckling occurred in the outer layer during an equal bending test. [Figure 19] 10 is a graph illustrating the results of an equal bending test. [Figure 20] FIG. 10 is a diagram illustrating the method of bending shear testing performed on the channel steel joint structure according to this embodiment, looking from the front at the plate surface of the outer layer of the first channel steel. [Figure 21] Figure 21(A) is a photograph illustrating the final state of the joint of the joint structure of the example, which was destroyed by a bending shear test, and Figure 21(B) is a photograph illustrating the final state of the joint of the joint structure of the second comparative example. [Figure 22] 1 is a graph illustrating the results of a bending shear test. DETAILED DESCRIPTION OF THE INVENTION

[0032] An embodiment of the present disclosure will be described below. In the following description of the drawings, identical or similar parts are designated by the same or similar reference numerals. However, the relationship between thickness and planar dimensions in the drawings, the thickness ratios of each device and each component, etc., differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined with reference to the following description. Furthermore, parts with different dimensional relationships and ratios are included among the drawings.

[0033] <Channel steel> First, the channel steel according to this embodiment will be described with reference to Figures 1 to 4. As shown in Figure 1, the channel steel 10 according to this embodiment is a long channel steel 10 formed from a single steel plate and having a web 12 and a pair of flanges 14. Specifically, the channel steel 10 can be formed by bending and shaping a single steel plate using a roll forming device, a bender device, or the like.

[0034] Each of the pair of flanges 14 of the channel steel 10 includes a base 14A, a folded portion 14B located at the end of the base 14A opposite the web 12, and an outer layer portion 14C. Note that in the present disclosure, it is not essential that both of the pair of flanges of the channel steel include a base, a folded portion, and an outer layer portion. In the present disclosure, it is sufficient that at least one of the flanges includes a base, a folded portion, and an outer layer portion.

[0035] In this embodiment, the pair of flanges 14 are configured symmetrically across a horizontal center line C that passes through the web 12 in Fig. 2. Therefore, the configuration of one flange 14 on the upper side in Fig. 2 is the same as the configuration of the other flange 14 on the lower side. Therefore, in this specification, only the base portion 14A, folded portion 14B, and outer layer portion 14C of one flange 14 will be described in detail, and a duplicated description of the other flange 14 will be omitted.

[0036] (base) The base 14A is a flat, band-shaped portion that is continuous with the web 12 in each of the pair of flanges 14. As shown in Fig. 1, the outer surface of the base 14A is exposed at the end in the longitudinal direction L1. In this specification, the "longitudinal direction of the channel steel" means a direction that is perpendicular to the opposing direction of the pair of flanges 14 (the up-and-down direction in Fig. 1) and extends parallel to the plate surface of the web 12 (the direction extending between the lower left and upper right in Fig. 1).

[0037] (outer layer) 1, the outer layer portion 14C is disposed on the outer surface side of the base portion 14A in a portion excluding the end portion in the longitudinal direction L1 of the flange 14. The outer layer portion 14C is a band-shaped flat portion of the flange 14 that is continuous with the folded-back portion 14B and extends from the folded-back portion 14B toward the web 12 alongside the base portion 14A.

[0038] In this embodiment, the outer layer portion 14C is not disposed at either end in the longitudinal direction L1, but this disclosure is not limited to this. In this disclosure, an outer layer portion may be disposed at one of the end portions in the longitudinal direction, and no outer layer portion may be disposed at the other end. In addition, "the outer surface side of the base portion 14A" means the side opposite the opening 16 of the channel steel 10.

[0039] In this embodiment, the length in the longitudinal direction L1 can be set to, for example, approximately 2800 mm to approximately 3000 mm. The flange width WF measured along the horizontal left-right direction in FIG. 2 can be set to approximately 33 mm, the web-direction height HW measured along the vertical up-down direction in FIG. 2 can be set to approximately 60 mm, and the plate thickness of the channel steel 10 can be set to approximately 1.2 mm. That is, the channel steel 10 according to this embodiment is a so-called light-gauge channel steel formed from a thin plate. In the present disclosure, the channel steel is not limited to a light-gauge thin-plate steel, and may be a steel having any plate thickness.

[0040] The "web height HW" in this embodiment is one of the dimensional elements that defines the outer edge of the rectangular cross-sectional shape of the channel steel, and corresponds to the "web height" in a general channel steel that does not have an outer layer portion. In addition, in this disclosure, the longitudinal length, flange width, web height, and plate thickness can be changed as appropriate.

[0041] Here, the aspect ratio of the length to width of the plate surface of the web 12 when viewed from the front is defined as (length in the longitudinal direction L1) / (web direction height HW). In this embodiment, the aspect ratio of the channel steel 10 can be set to, for example, about 4 to 5 times. Specifically, for example, when the web direction height HW is about 60 mm to 75 mm, the length in the longitudinal direction L1 can be set to about 300 mm. In this embodiment, "long" means that the aspect ratio of the channel steel is 4 times or more. Note that in the present disclosure, the aspect ratio is not limited to 4 to 5 times and can be set to any value.

[0042] In addition, in this embodiment, the length from the right end of the folded portion 14B to the left end of the outer layer portion 14C, measured along the left-right direction in Figure 2, will be described as the "width WC of the outer layer portion 14C." The width WC of the outer layer portion 14C is preferably set to be 50% or more and 100% or less of the flange width WF. If the width WC of the outer layer portion 14C is less than 50% of the flange width WF, it is difficult to ensure the bending resistance of the channel steel 10. Furthermore, if the width WC of the outer layer portion 14C exceeds 100% of the flange width WF, it is likely to hinder the miniaturization of the channel steel 10 and make it difficult to manufacture the channel steel 10.

[0043] In this embodiment, the width WC of the outer layer portion 14C is approximately 90% of the flange width WF. Furthermore, in the present disclosure, the width WC of the outer layer portion 14C can be set arbitrarily.

[0044] (Another example of the outer layer: Modified example 1) In the present embodiment, the outer layer portion 14C is overlapped on the outer surface of the base portion 14A, thereby forming the outer layer portion 14C disposed on the outer surface side of the base portion 14A. However, the present disclosure is not limited to this. In the present disclosure, for example, the outer layer portion 14C may be disposed substantially parallel to the base portion 14A with a small gap G therebetween, as in the first modified example illustrated in FIG. 3(A). From the viewpoint of ensuring accuracy during assembly of the structure, it is preferable that the width of the gap G measured in the vertical direction in FIG. 3(A) be at least 1.5 mm or less.

[0045] If the width of the gap G exceeds 1.5 mm, the fluctuation range of the dimension in the height direction (web height direction) becomes large, making it difficult to ensure precision when manufacturing a structure by assembling the channel steel 10. Furthermore, from the viewpoint of ensuring precision, it is more preferable that the width of the gap G be 1.0 mm or less.

[0046] The outer layer portion 14C of the first modified example is included in the "outer layer portion arranged on the outer surface side of the base portion" of the present disclosure. Even if the outer layer portion 14C is arranged substantially parallel to the base portion 14A with a small gap G therebetween, it is possible to achieve both a reduction in the cross-sectional dimensions of the channel steel 10 and ensuring bending resistance.

[0047] (Another example of the outer layer: Modified example 2) Furthermore, in the present disclosure, as in a second modified example illustrated in FIG. 3(B), the folded portion 14B may extend toward the opening 16 of the channel steel 10, thereby protruding toward the opening 16. The protruding folded portion 14B can function like the lip portion of a so-called lip channel steel in the channel steel 10. In the case of the channel steel 10 illustrated in FIG. 3(B), the joint with another structural member is formed at the end of the portion where the outer layer portion 14C is not located, so even if the folded portion 14B protrudes, no step is created between the outer surface of the outer layer portion 14C and the outer surface of the flange of the other structural member.

[0048] In other words, when the plate thickness is large or when a steel plate with large spring back, such as a high-strength steel plate, is used, for example, low accuracy in hemming bending may cause a bulge in the folded portion 14B of the flange 14. However, by applying the configuration of the second modified example, it is possible to avoid a step from occurring between the outer surface of the outer layer portion 14C and the outer surface of the flange of another structural member.

[0049] The outer layer portion 14C according to the second modification is included in the "outer layer portion arranged on the outer surface side of the base portion" of the present disclosure. Even the outer layer portion 14C that is in partial contact with the base portion 14A can achieve both a reduction in the cross-sectional dimensions of the channel steel 10 and ensuring bending resistance.

[0050] In addition, although the present embodiment illustrates a case in which the outer layer portion 14C is folded back at approximately 180 degrees, the present disclosure is not limited to this. As can be seen from the state of the outer layer portion 14C in Figure 3(B), the folding angle may be other than 180 degrees and can be changed as appropriate.

[0051] (Another example of the outer layer: third modified example) In the present embodiment, a single outer layer portion 14C is superimposed on the outer surface of the base portion 14A, but this disclosure is not limited to this. In the present disclosure, multiple outer layer portions 14C may be superimposed on the outer surface of the base portion 14A. In the third modified example in FIG. 4(A), a case where two outer layer portions 14C are superimposed on the outer surface of the base portion 14A is illustrated. According to the third modified example, the total plate thickness of the flange 14 is greater than when there is a single outer layer portion 14C, thereby further strengthening bending resistance.

[0052] (Another example of the outer layer: Fourth modified example) Furthermore, as in a fourth modified example illustrated in Fig. 4(B), the tip region of the outer layer portion 14C on the side opposite the folded portion 14B (left side in Fig. 4(B)) may extend beyond the web 12 to the outside of the channel steel 10 (left side in Fig. 4(B)). By extending the tip region of the outer layer portion 14C beyond the web 12, it is possible to increase the area of ​​the portion that can be used for joining to other building components, for example.

[0053] (Another example of the outer layer: fifth modified example) 5, the portion of the outer layer portion 14C at the tip end opposite the folded-back portion 14B (left side in FIG. 5) that extends beyond the web 12 is bent by approximately 90 degrees along the plate surface of the web 12. The inner surface of the bent tip end portion of the outer layer portion 14C contacts the outer surface of the web 12.

[0054] Here, when a single outer layer portion 14C is placed on the outer surface of the base portion 14A, the outer layer portion 14C may float above the designed range from the base portion 14A, i.e., may separate from the base portion 14A. In the fifth modified example, the floating state of the outer layer portion 14C can be suppressed by using the frictional resistance of the contact surface between the outer surface of the web 12 and the tip of the outer layer portion 14C, making the floating state of the outer layer portion 14C less noticeable in appearance.

[0055] <Channel steel manufacturing method> Next, a method for manufacturing a channel steel according to this embodiment will be described with reference to Figures 6 and 7. In this embodiment, a case will be described as an example in which a channel steel 10 is manufactured by bending a single steel plate 100, which is a raw material.

[0056] As shown in Fig. 6 , first, a single steel plate 100 having a rectangular shape in a plan view is prepared, and the prepared steel plate 100 is divided into one web intended region 120 and two flange intended regions 140 located on both the left and right ends of the web intended region 120. The web intended region 120 forms the web 12 when the steel plate 100 is formed into the channel steel 10. The two flange intended regions 140 form a pair of flanges 14 when the steel plate 100 is formed into the channel steel 10.

[0057] Furthermore, in one steel plate 100, the two planned flange regions 140 are divided into a band-shaped planned base region 140A that is continuous with the planned web region 120, and a band-shaped planned outer layer region 140C that is located on the opposite side of the planned base region 140A from the planned web region 120. The boundary region between the planned base region 140A and the planned outer layer region 140C is divided into a planned bent portion region 140B. In the present disclosure, it is sufficient that at least one of the two planned flange regions in one steel plate is divided into a planned base region and a planned outer layer region.

[0058] Next, the longitudinal direction L1 ends of the outer layer portion planned region 140C of the steel plate 100 are removed using a cutting device or the like. In Fig. 6, the four planned removal regions X located at the four corners of the steel plate 100 and to be removed are illustrated as rectangular regions with diagonal lines for ease of viewing.

[0059] Next, as shown in Fig. 7, the two left and right intended outer layer portion regions 140C are folded back toward the intended web region 120 along the intended folding portion region 140B. In Fig. 7, the intended outer layer portion region 140C before folding back is illustrated by a dotted line, and the intended outer layer portion region 140C after folding back is illustrated by a solid line. The folded intended outer layer portion region 140C is disposed as an outer layer portion above the intended base region 140A. The intended base region 140A with the outer layer portion disposed above it is formed as a base.

[0060] Next, the intended base region 140A with the intended outer layer region 140C arranged on the upper side is folded toward the side opposite the intended outer layer region 140C, i.e., toward the web side (the center side in the left-right direction in FIG. 7), so as to be perpendicular to the intended web region 120. In FIG. 7, the intended base region 140A and the intended outer layer region 140C after folding are illustrated by dashed lines.

[0061] By bending perpendicularly, the web intended region 120 is formed as the web 12 of the channel steel 10 in FIG. 1. The base intended region 140A is formed as the base 14A of the flange 14 of the channel steel 10 in FIG. 1. The bent portion intended region 140B is formed as the folded portion 14B of the flange 14 of the channel steel 10 in FIG. 1. The outer layer intended region 140C is formed as the outer layer 14C of the flange 14 of the channel steel 10 in FIG. 1. The channel steel 10 according to this embodiment can be obtained by the above series of steps.

[0062] In the present disclosure, after removing the four intended removal regions X from one steel plate 100, the channel steel 10 may be formed by first bending the steel plate 100 at approximately 90 degrees at the boundary between the intended web region 120 and the intended base region 140A. Then, the outer layer portion 14C can be formed by bending the steel plate 100 at approximately 180 degrees along the intended bend region 140B in the intended outer layer portion region 140C.

[0063] In the present disclosure, for example, by roll forming or the like, a shaped steel may first be formed having an outer diameter with a C-shaped cross section and a flange on which the outer layer portion planned region 140C is superimposed over the entire flange including the end in the longitudinal direction L1. That is, a shaped steel having a C-shaped cross section is formed without removing the planned removal region X.

[0064] Then, a channel steel 10 having the outer layer portion 14C may be manufactured by partially removing the portions corresponding to the intended removal regions X from the intended outer layer portion regions 140C at the four ends in the longitudinal direction L1 of the formed steel beam using a cutting device or the like. However, when first removing the four intended removal regions X using a cutting device or the like, there may be cases where the workload is heavy, such as requiring accurate alignment during cutting. For this reason, a method in which the four intended removal regions X are first removed from a single steel plate 100 and then the steel plate 100 is formed is more likely to reduce the overall manufacturing cost.

[0065] <Channel steel joint structure> Next, the joining structure of the channel steel according to this embodiment will be described with reference to FIGS.

[0066] (frame member) As shown in FIG. 8, the frame member 300 according to this embodiment has a set of vertical members 310 and a set of horizontal members 320. The set of vertical members 310 is disposed at both ends in the left-right direction in FIG. 8, and extends in the up-down direction. In this embodiment, in addition to the set of vertical members 310 disclosed herein, a vertical member 310 is also disposed secondary to the center in the left-right direction in FIG. 8. Note that, in this disclosure, it is not essential that the vertical members 310 be disposed secondary. Furthermore, the number of secondary vertical members 310 is not limited to one, and may be two or more, and can be set arbitrarily.

[0067] Furthermore, a pair of horizontal members 320 are arranged at both ends in the up-down direction in FIG. 8 . A pair of vertical members 310 and a pair of horizontal members 320 form the frame portion of the frame member 300. Note that, in the present disclosure, a pair of vertical members does not have to be arranged at both ends in the arrangement direction of the pair of vertical members, and one or two vertical members of the pair may be arranged at positions displaced a certain distance from the end toward the center in the arrangement direction, as long as a frame member can be formed. Similarly, in the present disclosure, a pair of horizontal members does not have to be arranged at both ends in the arrangement direction of the pair of horizontal members, and one or two horizontal members of the pair may be arranged at positions displaced a certain distance from the end toward the center in the arrangement direction.

[0068] (Vertical member) The vertical members 310 at both the left and right ends in FIG. 8 and the vertical member 310 secondary placed in the center are arranged parallel to each other with a gap between them. The channel steel 10 illustrated in FIG. 1 is used as the vertical members 310. The vertical members 310 constitute the first channel steel of the present disclosure. Note that in the present disclosure, the vertical members 310 are not limited to the first channel steel, and members other than the first channel steel may be attached to the vertical members 310.

[0069] In the present embodiment, a case where a first channel steel is used for the vertical member 310 and a second channel steel is used for the horizontal member 320 will be exemplified below, but in the present disclosure, a first channel steel may be used for the horizontal member and a second channel steel may be used for the vertical member. In the present disclosure, when one first channel steel and one second channel steel are used, there is no limitation as to whether each channel steel is arranged in a vertical member or a horizontal member.

[0070] (Horizontal material) The set of horizontal members 320 is formed from a single steel plate 100 separate from the single steel plate 100 for the first channel steel, and has a web 12 and a pair of flanges 14. The horizontal members 320 constitute the second channel steel of the present disclosure. In the present disclosure, similar to the vertical members 310, the horizontal members 320 may also be attached to members other than the second channel steel, and are not limited to only the second channel steel.

[0071] The horizontal members 320 are joined to the vertical members 310 at one end (for example, the upper end in FIG. 8) and the other end (for example, the lower end in FIG. 8) of all the vertical members 310, with the longitudinal direction L2 of the horizontal members 320 perpendicular to the longitudinal direction L1 of the vertical members 310. In the present disclosure, it is sufficient that at least one set of horizontal members 320 is joined to one set of vertical members 310 at one end and the other end of the set of vertical members 310, with the longitudinal direction L2 of the horizontal members 320 perpendicular to the longitudinal direction L1 of the vertical members 310.

[0072] In this embodiment, both one steel plate 100 constituting the first channel steel as the vertical member 310 and another steel plate 100 constituting the second channel steel as the horizontal member 320 are plated steel plates that have been plated in advance, i.e., pre-plated steel plates. Note that in the present disclosure, it is sufficient that at least one of the one steel plate 100 and the other steel plate 100 is a plated steel plate.

[0073] (joint structure) Next, the joining structure of the channel steel according to this embodiment will be described in detail. In this embodiment, as shown in FIG. 8, the joining structure of the channel steel is formed at all six joints between the vertical members 310 and the horizontal members 320. For this reason, in the following description, the joint corresponding to the corner A at the bottom left in FIG. 8 will be described as a representative example. Note that in this disclosure, it is not necessary for the joining structure of the channel steel similar to that of corner A in FIG. 8 to be formed at all joints between the vertical members and the horizontal members; it is sufficient that it is formed at at least one.

[0074] As shown in Figure 9, in the joining structure of channel steel, a vertical member 310 as a long first channel steel and a horizontal member 320 as a long second channel steel are joined in a state where the longitudinal direction L1 of the vertical member 310 and the longitudinal direction L2 of the horizontal member 320 are perpendicular to each other.

[0075] In this embodiment, as shown in Fig. 9, a case where the vertical member 310 serving as the first channel steel and the horizontal member 320 serving as the second channel steel are perpendicular to each other is exemplified in which the crossing angle between the plate surface of the flat web 312 of the vertical member 310 and the plate surface of the flat web 322 of the horizontal member 320 is 90 degrees. However, in this disclosure, "perpendicular" is not limited to a crossing angle of exactly 90 degrees. If the crossing angle between the plate surface of the flat web of the vertical member and the plate surface of the flat web of the horizontal member is 85 degrees or more and 95 degrees or less, it can be considered "perpendicular."

[0076] As shown in Figures 10 and 11, in this embodiment, a pair of flanges 324 of the horizontal member 320 as the second channel steel are joined to the outer surfaces of the respective bases 314A at the longitudinal end portions L1 of a pair of flanges 314 of the vertical member 310 as the first channel steel.

[0077] In this embodiment, the thickness of the base 314A of the flange 314 of the vertical member 310 is the same as the thickness of the flange 324 of the horizontal member 320. Furthermore, in the vertical member 310 formed from a single steel plate, the thickness of the outer layer portion 314C of the flange 314 is also the same as the thickness of the base 314A. Therefore, as shown in FIG. 10 , the outer surface of the outer layer portion 314C of the flange 314 of the vertical member 310 and the outer surface of the flange 324 of the horizontal member 320 are flush with each other in the vertical direction. As a result, in the joining structure of channel steel according to this embodiment, no unevenness occurs with the outer surface of the joint. Note that, in the present disclosure, the thickness of the base of the flange of the vertical member and the thickness of the flange of the horizontal member may be different from each other.

[0078] (Joint tool) In this embodiment, the joining method between the base 314A of the flange 314 of the vertical member 310 as the first channel steel and the flange 324 of the horizontal member 320 as the second channel steel is a dry joining method using connectors 30. Specifically, two screws are used as connectors 30 for the base 314A of one flange 314.

[0079] In this embodiment, the number of joining positions for the screws serving as the fasteners 30 is exemplified as two for the base 14A of one flange 14, but the number of joining positions is not limited to this in the present disclosure. In the present disclosure, the number of joining positions for the base 14A of one flange 14 may be one, or may be any number, such as two or more, depending on the joining method.

[0080] Furthermore, in this embodiment, a method in which screws are used as the fasteners 30 is exemplified as a specific method of dry joining, but this disclosure is not limited to this. In this disclosure, other dry joining fasteners, such as bolts and nuts, may also be used. In addition, in this disclosure, the joining structure may be formed by "caulking." Note that in this disclosure, the joining method is not limited to dry joining, and may also be wet joining.

[0081] As shown in Figure 11, when the screws serving as the connector 30 are driven in the same straight line into each of the opposing flanges 14 in the left-right direction in which they extend, the screws are positioned so that they do not overlap when the heads of the screws serving as the connector 30 are viewed from the front, as shown in Figure 9.

[0082] For example, imaginary line V1 in Fig. 9 is a dashed line that connects the centers of the screw heads of two fasteners 30 that appear in a circular shape on the front side of the paper in Fig. 9. Also, imaginary line V2 in Fig. 9 is a dashed line that connects the centers of the screw heads of two fasteners 30 that appear in a circular shape on the back side of the paper in Fig. 9. The screws to be driven into each of the opposing flanges 14 are positioned so that imaginary line V1 and imaginary line V2 intersect.

[0083] Note that protrusion of the screw heads may be suppressed by, for example, forming an area with a lower surface height by embossing or the like around the intended placement position of the screws of the connector 30 on the outer surface of the flange 324 of the horizontal member 320. By suppressing the protrusion of the screw heads, the outer surface of the flange 324 of the horizontal member 320 and the outer surface of the outer layer portion 314C of the flange 314 of the vertical member 310 can be made even more flush.

[0084] Furthermore, instead of simply joining the flanges 314 of the vertical members 310 and the flanges 324 of the horizontal members 320, it is also possible to integrate the flanges 314 of the vertical members 310 and the flanges 324 of the horizontal members 320 with the face member 40, as shown in Fig. 12. By providing the face member 40 to the frame member 300 according to this embodiment, a panel member 400 comprising the frame member 300 and the face member 40 can be realized.

[0085] Furthermore, as shown in Figure 12, when one or more components are integrated into the frame member 300 using, for example, screws, it is preferable to form through holes in advance in the flange 314 of the vertical member 310 and the flange 324 of the horizontal member 320 to reduce the burden when driving the screws.

[0086] 12, when a fastener 30 such as a screw is driven from the opening 16 side of the inside of the joint, it may be difficult to secure sufficient space for the driving work. In other words, since a rod-shaped tool such as a screwdriver is required for the driving work, the work may only be performed from the outside of the joint.

[0087] For this reason, through holes for inserting tools are formed in advance along the thickness direction as tool holes, such as through holes TH1 and TH2 provided in the base 314A of the vertical member 310 and the flange 324 of the horizontal member 320 located on the right side in Fig. 12. When the vertical member 310 and the horizontal member 320 are aligned in a stacked position, the through hole TH1 in the base 314A of the vertical member 310 and the through hole TH2 in the flange 324 of the horizontal member 320 function as a single tool hole when the plate surface of the flange 324 of the horizontal member 320 is viewed from the front.

[0088] Although not shown, a second tool hole separate from the first tool hole formed by the through holes TH1 and TH2 is formed in each of the base 314A of the vertical member 310 and the flange 324 of the horizontal member 320. The second tool hole can be formed in the same manner as the first tool hole, for example, at a position corresponding to the center position of the screw head at the lower left on the imaginary line V2 in Fig. 9. In other words, two tool holes are arranged overall on one flange side on the right side in Fig. 12.

[0089] When the plate surface of the flange 324 of the horizontal member 320 is viewed from the front, an imaginary line connecting the centers of the two tool holes (see imaginary line V2 in FIG. 9) intersects with an imaginary line connecting the heads of the two screws of the connector 30 arranged on the right side in FIG. 12 (see imaginary line V1 in FIG. 9). Then, by overlapping and aligning the vertical member 310 and the horizontal member 320 at the construction site, two tool holes are formed at the joint between the vertical member 310 and the horizontal member 320 on the right side, which corresponds to one flange side in FIG. 12. Then, by inserting a rod-shaped tool such as a screwdriver into the two tool holes and reaching the tip of the tool to the position of the left joint, which corresponds to the other flange side in FIG. 12, it becomes possible to drive screws into the left joint from the inside opening 16 side before fastening the right joint with screws.

[0090] <Manufacturing method for channel steel joint structure> As a manufacturing method for the joining structure of the channel steel according to this embodiment, the channel steel 10 according to this embodiment is manufactured as the vertical member 310 by the "manufacturing method of channel steel" described above using Figures 6 and 7. In addition, a general channel steel without an outer layer portion is prepared as the horizontal member 320. Next, as shown in Figure 13, the inner surfaces of the pair of flanges 324 of the horizontal member 320 are overlapped on the outer surfaces of the base portions 314A exposed at the ends in the longitudinal direction L1 of the pair of flanges 314 of the manufactured vertical member 310.

[0091] In this embodiment, the vertical member 310 and the horizontal member 320 overlap so that the longitudinal direction L1 of the vertical member 310 and the longitudinal direction L2 of the horizontal member 320 are perpendicular to each other. In FIG. 13 , the joining position 30A corresponding to the position where a screw is driven into the flange 324 of the horizontal member 320 is illustrated by a dotted oval. Then, the overlapping flanges 314 of the vertical member 310 and the flanges 324 of the horizontal member 320 can be joined together, for example, by screws. The above series of steps constitutes the manufacturing method for a channel steel joining structure according to this embodiment. [Example]

[0092] (Behavior of channel steel) Next, the behavior of the channel steel 10 according to the example of this embodiment will be described with reference to Figures 14 and 15. Note that the configuration of the channel steel 10Z according to the first comparative example illustrated in Figure 15 is the same as the longitudinal dimensions, web height, and flange width of the channel steel 10 according to this embodiment illustrated in Figure 1, respectively, as the channel steel 10 according to the example. Furthermore, the channel steel 10Z according to the first comparative example has a base 14A and a folded portion 14B, similar to the channel steel 10 according to the example. However, the first comparative example differs from the example in that the portion of the flange 14 opposite the web 12, which is continuous with the base 14A, is overlapped on the inner surface of the base 14A on the opening 16 side as an inner layer portion 14Z.

[0093] First, as shown in Figure 14(A), consider the case where a bending moment acts on the channel steel 10 according to the embodiment, for example, on the outer layer 14C of the upper flange 14 due to an external force acting vertically from above to below. In this case, compressive stress acts on the upper flange 14 of the channel steel 10 in a direction perpendicular to the cross section (the material axis direction of the channel steel 10), and tensile stress acts on the lower flange 14 in a direction perpendicular to the cross section. Therefore, if an excessive bending moment acts, the upper flange 14 (especially the outer layer 14C) subjected to the compressive stress may buckle in an out-of-plane direction, resulting in a decrease in bending resistance. Furthermore, the channel steel 10 is deformed downward by the bending moment. At this time, as shown in Figure 14(B), the cross section of the channel steel 10 deforms so that the upper outer layer 14C and the base 14A, which are subjected to compressive stress, are pushed toward the lower opening 16. In FIG. 14(B), for the sake of convenience of explanation, the deformation behavior of the flange 14 of the channel steel 10 after receiving a force is illustrated by a dotted line.

[0094] That is, in the embodiment, when an external bending moment is received by the channel steel 10, the base portion 14A and the outer layer portion 14C are in close contact with each other over substantially the entire width direction of the flange (the left-right direction in FIG. 14(B)). Due to this close contact, in the section where the bending moment occurs, i.e., the entire region in the flange 14 where compressive stress and tensile stress are distributed along the material axis direction, the base portion 14A and the outer layer portion 14C resist the bending moment while mutually restraining each other in the out-of-plane direction, thereby suppressing buckling due to the compressive stress.

[0095] Furthermore, within the flange 14, the outer layer portion 14C is partially compressed as a result of the direct action of the external force in the out-of-plane direction. Because the external force acts on this compressed portion, the mutual constraint state between the base portion 14A and the outer layer portion 14C caused by the action of the bending moment is further enhanced locally. As a result, the effect of mutual constraint in suppressing buckling can be enhanced, and therefore, there is no need to previously integrate the base portion 14A and the outer layer portion 14C by, for example, welding.

[0096] 15(A), consider a case where a bending moment acts on the channel steel 10Z according to the first comparative example due to an external force acting vertically from above to below, for example, on the base 14A of the upper flange 14. In this case, as in the example, a compressive stress acts on the upper flange 14 of the channel steel 10Z in the direction perpendicular to the cross section, and a tensile stress acts on the lower flange 14 in the direction perpendicular to the cross section.

[0097] At this time, as shown in Figure 15(B), the cross section of the channel steel 10Z is deformed such that the inner layer portion 14Z and the base portion 14A on the side receiving the compressive stress move away from each other and are pushed toward the lower opening 16. As a result, a gap is formed between the base portion 14A and the inner layer portion 14Z. Note that in Figure 15(B), as in Figure 14(B), the deformation behavior of the flange 14 of the channel steel 10Z after receiving the force is illustrated by dotted lines.

[0098] That is, in the first comparative example, there is no mutual constraint between the base portion 14A and the inner layer portion 14Z. Therefore, when an external bending moment is received by the channel steel 10Z, the base portion 14A, which is separated from the inner layer portion 14Z, resists the compressive stress almost solely. As a result, in the first comparative example, it is difficult to prevent the upper flange 14 (especially the inner layer portion 14Z) from buckling in the out-of-plane direction, and it is difficult to achieve the bending resistance obtained in the example.

[0099] FIG. 16 also illustrates a joining structure in which a channel steel 10Z according to a first comparative example, serving as a first channel steel, is joined to a channel steel 20, serving as a second channel steel. In the joining structure illustrated in FIG. 16, an inner layer portion 14Z of the channel steel 10Z of the first comparative example is joined to a flange 24 of the channel steel 20. The joining position in FIG. 16 can be identified by a connector 30. A countersink hole 14A1 is provided at a position corresponding to the connector 30 on the base portion 14A of the channel steel 10Z of the first comparative example. The connector 30 is positioned inside the countersink hole 14A1 and penetrates the inner layer portion 14Z and the flange 24 of the channel steel 20, serving as the second channel steel.

[0100] Here, in the channel steel 10Z of the first comparative example, the inner layer portion 14Z is not directly continuous with the web, but is connected to the web via the base portion 14A. Also, in the channel steel 10Z of the first comparative example, the connector 30 does not directly contact the base portion 14A. Therefore, the distance along the plate element from the joining position between the channel steel 10Z and the channel steel 20 to the web of the channel steel 10Z becomes longer.

[0101] 10 and 11, in this embodiment, the cross member 320 as the second channel steel is joined not to the outer layer portion 14C of the channel steel 10 as the first channel steel, but to the base portion 14A that is directly continuous with the web 12. That is, in the first comparative example in which the inner layer portion 14Z is not directly continuous with the web but is connected to the web via the base portion 14A, when a force acting on the joint flows from the plate portion of the flange to the plate portion of the web, the overall length of the force conduction path formed by the plate portions is longer than in this embodiment.

[0102] In other words, for example, if a channel steel bent from a single steel plate is unfolded and reverted to a single steel plate, the shortest distance between the web plate portion and the joint position within the single steel plate in the first comparative example is longer than the shortest distance in the present embodiment. Therefore, in the case of the joint structure of the channel steel 10 according to the example, which is the joint structure of the channel steel according to the present embodiment, the joint position is closer to the web 12 than in the first comparative example. As a result, the joint strength of the joint structure of the channel steel 10 according to the example can be increased compared to the joint strength of the joint structure using the channel steel 10Z according to the first comparative example. On the other hand, in the first comparative example, the overall length of the force conduction path is longer than in the present embodiment, which reduces the efficiency of stress transmission, potentially resulting in unnecessary deformation.

[0103] (Equal bending test of channel steel) Next, the constant bending test of the channel steel 10 according to the example will be described with reference to Figs. 17 to 19. As shown in Fig. 17, in the constant bending test, a load was applied to both ends in the longitudinal direction L1 of the test section R, which has a certain length in the center of the channel steel 10 according to the example, so that a constant bending state was generated in the test section R. Note that in this example, the portions other than the test section R were reinforced so as not to collapse before the test section R, but the present disclosure is not limited to whether or not they are reinforced.

[0104] The magnitude of bending resistance was measured when an out-of-plane bending force such as wind pressure was applied to the channel steel 10. Specifically, the initial elastic stiffness, yield strength, and maximum strength were measured from the time the bending force started to be applied until the flange 14 buckled and the member strength decreased. Figure 18 shows an example of the outer layer portion 14C of the flange 14 deformed in a wavy manner due to buckling.

[0105] The measured values ​​of initial elastic stiffness, yield strength, and maximum strength were then divided by the target values ​​set for each based on design requirements to calculate the values. During the constant bending test, the flange 14 did not buckle until the target values ​​were reached. In other words, after the initial elastic stiffness, yield strength, and maximum strength exceeded their respective target values, the outer layer portion 14C buckled as shown in FIG. 18.

[0106] The values ​​on the vertical axis in Figure 19 are target achievement rates, which are values ​​obtained by dividing the measured value by the target value. As shown in Figure 19, the target achievement rate for initial elastic stiffness was 1.06. The target achievement rate for yield strength was 1.48. The target achievement rate for maximum strength was 1.03.

[0107] As a result of the bending test, it was found that the initial elastic stiffness, yield strength, and maximum strength of the channel steel 10 according to the embodiment all met the target values. In other words, it was confirmed that the channel steel 10 according to the embodiment meets the required performance as a frame for panel members in terms of both stiffness and strength as bending resistance.

[0108] (Bending shear test using a channel steel joint structure) Next, a bending shear test using a channel steel joint structure according to an example of this embodiment will be described with reference to Fig. 20 to Fig. 22. First, as shown in Fig. 20, an L-shaped test specimen having a joint structure of one channel steel 10 as a first channel steel and one channel steel 20 as a second channel steel was fabricated as the channel steel joint structure according to the example. In the example, the channel steel 10 and the channel steel 20 were joined by screw joining as a dry joint.

[0109] Next, the channel steel 20 of the prepared specimen according to the example was fixed to a fixing jig 52 having a flat upper surface, which was fixed on a reaction floor 50. Specifically, the plate surface of the web of the channel steel 20 was brought into contact with the upper surface of the fixing jig 52, and the web of the channel steel 20 was bolted to the upper part of the fixing jig 52. In addition, the channel steel 10 was arranged so that the longitudinal direction of the channel steel 10 was vertical, and a hydraulic jack capable of applying a horizontal force was attached to the upper part of the channel steel 10 as a loading device 54.

[0110] The height HA from the top surface of the fixing jig 42 to the center of the mounting position of the hydraulic jack serving as the loading device 54 was 500 mm. The length D of the channel steel 20 in the longitudinal direction was 250 mm.

[0111] Then, a horizontal force was applied to the channel steel 10 of the test specimen, and while the horizontal force was gradually increased, the deformation followability of the channel steel joint structure against in-plane bending shear such as earthquake force was confirmed until the joint collapsed. Specifically, during the horizontal force loading, the deformation amount of the channel steel 10 at the loading position was measured until the strength of the joint in the joint structure deteriorated.

[0112] In addition, a test specimen for the joining structure of the channel steel of the test specimen according to the second comparative example was prepared. In the second comparative example, lip channel steels having the same shape and dimensions were joined. At the joint, the two lip channel steels were joined using wet welding, with the plate surfaces of the lips of a pair of flanges of one lip channel steel butting against the longitudinal end face of the other lip channel steel.

[0113] The web height and plate thickness of the lip channel steel of the second comparative example were the same as those of the channel steel 10 of the test specimen according to the example. The lip length of the lip channel steel of the second comparative example was 10 mm, and the flange width of the lip channel steel of the second comparative example was set so that the moment of inertia about the strong axis was the same as that of the channel steel 10 in the example. The deformation amount at the horizontal force loading position was also measured for the second comparative example, as in the example.

[0114] Figure 21(A) illustrates the state in which the joint collapses in the second comparative example. In the second comparative example, the welded joint breaks. Figure 21(B) illustrates the state in which the joint collapses in the example. In the example, the screw at the joint has come loose.

[0115] As shown in Fig. 22, in the case of the second comparative example, the maximum deformation amount at the horizontal force loading position was 27.1 mm. In addition, in the case of the channel steel joining structure according to the example, the maximum deformation amount at the horizontal force loading position was 26.0 mm. In other words, it was found that even in the example having two joining positions by dry joining, it is possible to achieve deformation followability of the joining structure to approximately the same extent as the deformation followability of the joining structure of the second comparative example using wet joining by welding.

[0116] (Action and effect) In the channel steel 10 according to this embodiment, the outer layer 14C is not disposed on the outer surface of the base 14A at the end of the flange 14 in the longitudinal direction L1, so that the outer surface of the base 14A is exposed. The end of the flange 14 in the longitudinal direction L1 functions as a joint with another structural member. For example, by preparing another channel steel 10 and joining the flange 14 of the prepared channel steel 10 to the outer surface of the base 14A at the end, a joined structure in which two channel steels 10 are joined can be obtained. In other words, since the plate thickness of the flange 14 is not increased at the end where the joint is formed in the joined structure, the burden of the joining work can be reduced compared to when, for example, a portion of the flange 14 is folded over to increase the plate thickness at the end where the joint is formed.

[0117] In this embodiment, in the portion of the flange 14 excluding the ends in the longitudinal direction L1, i.e., the central portion, the outer layer portions 14C, which are portions folded back toward the web 12, are arranged on the outer surface side of the base portion 14A in a state of extending side by side. Therefore, the thickness of the portion of the channel steel 10 excluding the ends, which has the outer layer portions 14C, is thicker than the thickness of the end portion not having the outer layer portions 14C. For example, if the channel steel 10 is formed from a single steel plate 100 with a substantially uniform thickness, the thickness of the flange 14 in the portion excluding the ends, which has the outer layer portions 14C, can be increased to twice the thickness of the flange 14 at the end portion consisting only of the base portion 14A.

[0118] That is, in the portion excluding the ends of the channel steel 10, the steel material is concentrated at the flange 14, which is the outer edge of the cross section, which is effective in improving bending resistance. Therefore, even if the cross-sectional dimension is reduced, the bending resistance per unit weight can be strengthened compared to the case of a channel steel 10 that does not have the outer layer portion 14C. In other words, the bending resistance can be reinforced by the outer layer portion 14C in the portion excluding the ends so that the bending resistance does not decrease due to the reduction in the cross-sectional dimension.

[0119] Therefore, according to this embodiment, it is possible to provide a channel steel 10 that can achieve both a smaller cross-sectional dimension and ensure bending resistance while reducing the burden of joining work.

[0120] In this embodiment, the width WC of the outer layer portion 14C is 50% to 100% of the flange width WF, which allows for more efficient balancing of bending resistance, i.e., rigidity and strength, with a smaller cross-sectional dimension.

[0121] In the joining structure of channel steel according to this embodiment, a first channel steel configured in the same manner as the channel steel 10 illustrated in Figure 1 is joined to a second channel steel, thereby providing a joining structure that can reduce the burden of joining work while achieving both a reduced cross-sectional dimension and ensuring bending resistance.

[0122] Furthermore, in this embodiment, the thickness of the base 14A of the flange 14 of the first channel steel is the same as the thickness of the flange 14 of the second channel steel. This makes it easy to align the outer surface of the flange 14 of the first channel steel, excluding the end portion, flush with the outer surface of the flange 14 of the second channel steel. In other words, unevenness in the outer surface of the joint can be eliminated. As a result, other components, such as face plates, can be joined to the joint in a snug and tight manner, thereby increasing the strength of the structural members, including the joint structure.

[0123] Furthermore, in this embodiment, when aligning the outer surface of the flange 14 of the portion excluding the end of the first channel steel flush with the outer surface of the flange 14 of the second channel steel, it is only necessary to process the first channel steel, and there is no need to process the shape of the second channel steel to be the same as the first channel steel. In this regard, in the case of the joint structure using the first channel steel of the first comparative example, the end of the second channel steel is inserted inside the C-shaped groove of the first channel steel, so in order to align the outer surfaces flush with each other, it is necessary to process the end of the second channel steel so that it is narrower than the portion excluding the end.

[0124] Furthermore, in this embodiment, unlike the first comparative example, there is no need to take the time and effort of processing the shape of the second channel steel, so the frame member 300 including the joining structure of the channel steel can be easily manufactured.

[0125] Furthermore, in this embodiment, one type of steel plate 100 having the same thickness can be used not only as the steel plate 100 for the first channel steel, but also as the steel plate 100 for the second channel steel, thereby reducing material costs.

[0126] Furthermore, in this embodiment, the vertical members 310 as the first channel steel and the horizontal members 320 as the second channel steel are integrated by dry joining using, for example, screws. In other words, the burden of wet joining welding, which requires skilled techniques, is not required. This reduces the manufacturing burden and ensures the required structural performance.

[0127] In this embodiment, the number of joining positions is two for the base 314A of one flange 314. If there is only one joining position, for example, when a single screw is used at the joining position, the vertical member 310 serving as the first channel steel and the horizontal member 320 serving as the second channel steel tend to rotate around the screw of the fastener 30. In this embodiment, because there are two joining positions for the base 314A of one flange 314, the occurrence of rotation, which occurs when there is only one joining position, is suppressed. Therefore, bending moments at the joints are easily transmitted between the first channel steel and the second channel steel. As a result, stable structural performance can be achieved.

[0128] In this embodiment, both the one steel plate 100 constituting the first channel steel and the other steel plate 100 constituting the second channel steel are pre-plated steel plates. By joining channel steels 10 formed from pre-plated steel plates, it is possible to save the effort of performing surface treatment such as plating or painting on the joined structure by electrodeposition or the like after joining unplated channel steels together.

[0129] Furthermore, when the joining method for the channel steel joining structure is wet welding, the welding damages the plated portion, and the damaged portion needs to be repaired after welding. Therefore, in the present embodiment, which uses dry joining without welding, the burden of repairing the damaged portion is reduced compared to when wet welding is used.

[0130] The frame member 300 according to this embodiment includes a joining structure in which a first channel steel is joined to a second channel steel, which can reduce the burden of joining work while simultaneously reducing the cross-sectional dimensions and ensuring bending resistance. This makes it possible to simultaneously reduce the cross-sectional dimensions of the frame member 300 itself and ensure bending resistance.

[0131] The panel member 400 according to this embodiment includes a frame member 300 in which a first channel steel is joined to a second channel steel, which can reduce the burden of joining work while simultaneously achieving a reduced cross-sectional size and ensuring bending resistance. This allows the cross-sectional size of the panel member 400 itself to be reduced while also ensuring bending resistance. Furthermore, since the frame member 300 is made smaller and lighter, it is easier to add components other than the frame member 300 to the panel member 400. This allows for diversification of the functions of the face plate 40. Furthermore, this improves the transportation efficiency of the panel member 400, i.e., improves logistics, and improves the on-site workability of the panel member 400.

[0132] The manufacturing method for channel steel according to this embodiment makes it possible to manufacture channel steel 10 that can achieve both a reduced cross-sectional dimension and sufficient bending resistance while reducing the burden of joining work, as in this embodiment.

[0133] Furthermore, as described in the example using FIG. 14 , in the present disclosure, when a bending moment caused by an external force in the out-of-plane direction is received by the channel steel 10, the base 14A and the outer layer 14C are in close contact with each other throughout. Due to this close contact, in the section where the bending moment occurs, the base 14A and the outer layer 14C are mutually constrained in the out-of-plane direction while resisting the bending moment, thereby suppressing buckling due to the compressive stress. Furthermore, within the flange 14, the outer layer 14C is partially compressed as a result of the direct action of the external force in the out-of-plane direction itself. Because the external force acts on this compressed portion, the mutual constraint between the base 14A and the outer layer 14C caused by the action of the bending moment is further locally enhanced. As a result, the buckling suppression effect due to the mutual constraint can be enhanced, eliminating the need to previously integrate the base 14A and the outer layer 14C by welding or the like.

[0134] In addition, the manufacturing method for the channel steel joint structure of this embodiment makes it possible to realize a channel steel joint structure that can achieve both a reduced cross-sectional dimension and sufficient bending resistance while reducing the burden of the joining work.

[0135] <Other embodiments> Although the present disclosure has been described by the above embodiments, this description does not limit the present disclosure, and it should be understood that various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from the present disclosure.

[0136] For example, in this embodiment, as shown in FIG. 1, the outer layer portion 14C is disposed on the outer surface side of the base portion 14A in the portion of the flange 14 excluding the end portion in the longitudinal direction L1. However, this disclosure is not limited to this. In this disclosure, the outer layer portion can be disposed at one or more locations, any number, at any position other than the end portion in the longitudinal direction of the flange, for example, at any position in the central portion. By disposing the outer layer portion at any position, the position where the joining structure is formed can be set arbitrarily. In other words, channel steel with a variety of specifications can be realized. Furthermore, by applying the joining structure of channel steel of the present disclosure to frame members or panel members, the types of frame members or panel members can also be diversified.

[0137] The present disclosure can also be configured by partially combining the configurations shown in Figures 1 to 22. The present disclosure includes various embodiments not described above, and the technical scope of the present disclosure is defined only by the invention-specifying matters in the claims that are appropriate from the above description. [Explanation of symbols]

[0138] 10 Channel steel (1st channel steel) 10Z channel steel 12. Web 14 flange 14A base 14A1 Zabori Hole 14B Folded part 14C Outer layer 14Z Inner layer 16 Opening 20 Channel steel (second channel steel) 30 Joints 40 Surface material 42 Fixture 50 Reaction floor 52 Fixture 54 Loading device 100 steel plate 120 Web Schedule Area 140 flange planned area 140A Base area 140B Planned folded area 140C Outer layer planned area 300 Frame members 310 Vertical member (first channel steel) 312 Web 314 flange 314A base 314C outer layer 320 Cross member (second channel steel) 322 Web 324 flange 400 Panel members A Corner part C center line G Gap HA Mounting height HW Web direction height L1 Longitudinal direction L2 Longitudinal direction R test section TH1 through hole TH2 through hole V1 Virtual Line V2 Virtual Line WF flange width WC Outer layer width X Area to be removed

Claims

1. A joining structure in which a long-sized first channel steel formed from a single steel plate and having a web and a pair of flanges, and a long-sized second channel steel formed from a single steel plate other than the single steel plate and having a web and a pair of flanges are joined together with their longitudinal directions perpendicular to each other, The pair of flanges of the first channel steel are a band-shaped base portion continuous with the web; a folded portion located at an end of the base opposite the web; a band-shaped outer layer portion disposed on the outer surface side of the base portion in a portion of the flange excluding the longitudinal end portion, and extending parallel to the base portion from the folded-back portion toward the web, a pair of flanges of the second channel steel are joined onto outer surfaces of the bases at longitudinal ends of the pair of flanges of the first channel steel, Channel steel joint structure.

2. The thickness of the base of the flange of the first channel steel is the same as the thickness of the flange of the second channel steel. The joining structure of a channel steel according to claim 1.

3. The joining method between the base of the flange of the first channel steel and the flange of the second channel steel is dry joining. The joining structure of a channel steel according to claim 1 or 2.

4. The number of joining positions where the dry joining is performed is two or more for the base portion of one flange. The joining structure of a channel steel according to claim 3.

5. At least one of the one steel sheet and the other steel sheet is a plated steel sheet. The joining structure of a channel steel according to any one of claims 1 to 4.

6. a pair of vertical members including a first channel steel member formed from a single steel plate and having a web and a pair of flanges, the vertical members being arranged parallel to each other with a gap therebetween; a set of horizontal members including a long second channel steel member formed from a steel plate other than the one steel plate and having a web and a pair of flanges, the horizontal members being joined at one end and the other end of the set of vertical members in a state where the longitudinal direction is perpendicular to the longitudinal direction of the vertical members; The channel steel joint structure according to any one of claims 1 to 5 is formed at at least one of the joints between the vertical member and the horizontal member. Frame components.

7. A frame member according to claim 6; a face material provided on the frame member; A panel member comprising:

8. A manufacturing method of a joining structure of channel steel in which a long-sized first channel steel formed from a single steel plate and having a web and a pair of flanges, and a long-sized second channel steel formed from a single steel plate other than the single steel plate and having a web and a pair of flanges are joined together with their longitudinal directions perpendicular to each other, A manufacturing method of a long channel steel having a web and a pair of flanges, In a steel plate having a web planned region forming the web and flange planned regions forming the pair of flanges, when at least one of the flange planned regions is divided into a band-shaped base planned region continuous with the web planned region and a band-shaped outer layer planned region located on the opposite side of the base planned region from the web planned region, removing an end portion in the longitudinal direction of the outer layer portion planned region of the steel plate; a step of folding back the outer layer portion intended region toward the web intended region, thereby disposing the folded outer layer portion intended region above the base intended region as an outer layer portion, and forming the base intended region with the outer layer portion disposed above it as a base; A process of forming the web planned area as the web of the channel steel by folding the base portion opposite to the outer layer portion so that it is perpendicular to the web planned area, and forming the base portion and the outer layer portion as the flange of the channel steel; The pair of flanges of the second channel steel are respectively joined onto the outer surfaces of the base portions of the pair of flanges of the first channel steel manufactured using a channel steel manufacturing method including: A manufacturing method for channel steel joint structures.

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