A Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange

Abstract

The present invention proposes a Z-shaped double-flange purlin with a reinforced cavity on the outer side of the flange, comprising a wide flange, a narrow flange and a web; the wide flange and the narrow flange are orthogonally connected to the two ends of the web; the wide flange and the narrow flange are both double-flanges formed by folding the full flanges at both ends of the web; a curling edge is provided at one end of the double-flange away from the web; the curling edge is bent more than twice to form a polygonal cavity; when two identical double-flange purlins are overlapped, the narrow flange of one purlin and the outer edge line of its curling plate are enveloping between the curling edge of the wide flange of the other purlin and the web. The present invention improves the plate stability of the compressed flange by folding the full flange to form a double-flange and setting a reinforced cavity on the outer side of the flange, thereby improving the material strength utilization rate of the purlin flange and the web, and improving the bearing capacity and economy of the purlin; compared with the traditional Z-shaped purlin, the technical effect of increasing the bearing capacity of the purlin by more than 15% with the same material usage is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of building profiles, in particular to a Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange. Background Art

[0002] At present, purlins usually adopt C-section steel or Z-section steel formed by cold-bending thin-walled steel plates, which are mainly used in light steel roof systems and wall systems with large spans and small loads. Although the cross-sections of C-section purlins and Z-section purlins are simple, their failure modes under roof / wall loads and wind loads are very complex due to their thin wall thickness. Under the premise of ensuring overall stability, the failure mode of purlins is usually local buckling of the compression flange. The premature local buckling of the flange leads to the failure to fully utilize the material strength of the flange and the web. When calculating the bending bearing capacity of the purlin, the buckling coefficient of the compression flange can be taken as 3.0, while the buckling coefficient of the web can reach 23.9 due to the large stress gradient, and the web material strength is relatively surplus. Therefore, in order to improve the economy of the purlin, it is necessary to optimize the cross-sectional form of the purlin. Summary of the invention

[0003] The purpose of the present invention is to propose a Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange, which improves the stability of the plate of the compressed flange by folding and reinforcing the entire flange and setting a reinforced cavity on the outer side of the flange, thereby improving the material strength utilization rate of the purlin flange and web, and improving the bearing capacity and economy of the purlin.

[0004] To achieve the above-mentioned purpose, the present invention proposes a Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange, wherein the purlin is a Z-shaped cross-section steel formed by cold bending a flat steel plate; it comprises a wide flange, a narrow flange and a web; the wide flange and the narrow flange are orthogonally connected to the two ends of the web;

[0005] The wide flange and the narrow flange are both double-layer flanges formed by folding the full flanges at both ends of the web; the double-layer flange includes a folded flange and an initial flange, and the folded flange is attached to the inner side or the outer side of the connected initial flange;

[0006] The double-layer flange is provided with a curling edge at one end away from the web; the curling edge is bent more than twice to form a polygonal cavity;

[0007] When two identical Z-shaped double-flange purlins are overlapped, the outer edge line of the narrow flange of one purlin and its rolled plate is wrapped around the area between the rolled edge of the wide flange of the other purlin and the web.

[0008] Furthermore, the cross-sectional length of the folded flange is greater than the cross-sectional length of the initial flange, so that the folded flange extends an extension relative to the initial flange and the bent portion of the web; the extension is vertically bent and fits against the web; the extension and the web are fixedly connected by welding or riveting, and the welding or riveting connection points are arranged at equal intervals along the length direction of the purlin.

[0009] Furthermore, the angle between the curled edge and the horizontal portion of the connected flange is 30 to 150 degrees.

[0010] Furthermore, the length of the extended edge is greater than or equal to 10 mm;

[0011] The distance between adjacent welding or riveting connection points is less than or equal to 300 mm.

[0012] Furthermore, the height-to-thickness ratio of the web is less than or equal to 250.

[0013] Furthermore, the width-to-thickness ratios of the wide flange and the narrow flange are different and are both less than or equal to 60.

[0014] Furthermore, the surface of the web is provided with a plurality of grooves at equal intervals through groove processing.

[0015] Compared with the prior art, the advantages of the present invention are:

[0016] 1. The present invention mainly folds the flange of the cold-formed steel and fixes it with the web, which not only increases the moment of inertia of the purlin in the bending plane, realizes the coordinated force of the flange and the folded flange, improves the stability of the compressed plate, but also enhances the constraint effect of the web on the flange, which is conducive to delaying the local buckling and distortion buckling of the flange. Studies have shown that compared with traditional purlins with the same thickness of flanges and webs, the present invention can achieve a purlin bearing capacity increase of more than 15% with the same material usage.

[0017] 2. The outer side of the flange of the purlin of the present invention is cold-bent into a polygonal cavity, which can enhance the constraint of the flange and the outer side of the folded flange by the curling, improve the stability of the flange plate and the out-of-plane stiffness of the Z-shaped purlin.

[0018] 3. The present invention adopts a special matching mode of narrow flange and wide flange and a reasonable setting of riveted outer convex surface, such as Figure 3 and 4 As shown, the influence of the polygonal cavity and the riveting points on the overlapping mode between adjacent Z-shaped purlins can be avoided, and the existing construction method is not changed while the bearing capacity of the purlins is improved, thereby ensuring the construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of the Z-shaped double-flange purlin in Example 1 of the present invention;

[0020] Figure 2 It is a plan view of a cross section of a Z-shaped double-flange purlin in Example 1 of the present invention;

[0021] Figure 3 Schematic diagram of overlapping of Z-shaped double-flange purlins in Example 1 of the present invention;

[0022] Figure 4 It is a plan view of the cross section of the overlapped portion of the purlin of the Z-shaped double-layer flange in Example 1 of the present invention;

[0023] Figure 5 Schematic diagram of the structure of the Z-shaped double-flange purlin in Example 2 of the present invention;

[0024] Figure 6 is a plan view of a cross section of a Z-shaped double-flange purlin in Example 2 of the present invention;

[0025] Figure 7 Schematic diagram of the structure of the Z-shaped double-flange purlin in Example 3 of the present invention;

[0026] Figure 8 is a plan view of a cross section of a Z-shaped double-flange purlin in Example 3 of the present invention;

[0027] Fig. 9 Schematic diagram of the structure of the Z-shaped double-flange purlin in Example 4 of the present invention;

[0028] Fig.10 It is a plan view of the cross section of the Z-shaped double-flange purlin in Example 4 of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further described below.

[0030] Embodiment 1:

[0031] A Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange, such as Figure 1 and Figure 2 As shown in the figure, a steel section with Z-shaped cross-section characteristics is formed by cold bending a flat steel plate with a thickness of 2 mm; the steel section includes a web 1, a wide flange 8 and a narrow flange 7; the wide flange 8 and the narrow flange 7 are orthogonally connected to the two ends of the web 1; the wide flange 8 and the narrow flange 7 are both double-layer flanges formed by folding the full flanges at both ends of the web 1; the double-layer flange includes a folded flange 3 and an initial flange 2, and the folded flange 3 is attached to the inner side or the outer side of the connected initial flange 2; a curling edge 4 is provided at one end of the double-layer flange away from the web 1; the curling edge 4 is bent more than twice to form a polygonal cavity, as shown in FIG. Figure 4As shown, the polygonal cavities of the wide flange 8 and the narrow flange 7 of this embodiment are two bilaterally symmetrical triangular cavities.

[0032] like Figure 3 and Figure 4 As shown, when two identical Z-shaped double-flange purlins are overlapped, the outer edge line of the narrow flange 7 of one purlin and its rolled plate is wrapped around the curling edge of the wide flange 8 of the other purlin to the web 1. Therefore, in the present invention, the wide and narrow in the wide flange 8 and the narrow flange 7 mean that the distance between the curling edge of the wide flange 8 and the web 1 can wrap around the narrow flange 7. The part that can wrap around is wide, and the part that is wrapped around is narrow.

[0033] The cross-sectional length of the folded flange 3 is greater than the cross-sectional length of the initial flange 2, so that the folded flange 3 extends an extension 5 relative to the initial flange 2 and the bent portion of the web 1; the extension 5 is vertically bent and fits with the web 1; the extension 5 and the web 1 are connected by rivets, and the connection points 6 of the rivet connection are arranged at equal intervals along the length direction of the purlin. In addition, this embodiment can also adopt welding or rivetless connection.

[0034] In this embodiment, the angle between the flange and the bead 4 directly connected to it is 135 degrees, and the angle between the folded flange 3 and the bead 4 directly connected to it is 90 degrees. The width-to-thickness ratio of the wide flange 8 is 35, and the width-to-thickness ratio of the narrow flange 7 is 32. The inner edge of the wide flange 8 and the bead 4 connected to it can envelop the outer edge of the narrow flange 7 and the bead connected to it. The height of the web 1 is 150 times its thickness; the side length of the extended edge 5 of the folded flange 3 is 15mm; the spacing between the rivet connection points 6 is 150mm.

[0035] Embodiment 2:

[0036] A Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange, such as Figure 5 and Figure 6 As shown in the figure, a steel section with Z-shaped cross-section characteristics is formed by cold bending a flat steel plate with a thickness of 2 mm; the steel section includes a web 1, a wide flange 8 and a narrow flange 7; the wide flange 8 and the narrow flange 7 are orthogonally connected to the two ends of the web 1; the wide flange 8 and the narrow flange 7 are both double-layer flanges formed by folding the full flanges at both ends of the web 1; the double-layer flange includes a folded flange 3 and an initial flange 2, and the folded flange 3 is attached to the inner side or the outer side of the connected initial flange 2; a curling edge 4 is provided at one end of the double-layer flange away from the web 1; the curling edge 4 is bent more than twice to form a polygonal cavity, as shown in FIG. Figure 6 As shown, the polygonal cavities of the wide flange 8 and the narrow flange 7 of this embodiment are two asymmetric triangular cavities.

[0037] Referring to Example 1 Figure 3As shown in the figure, when two identical Z-shaped double-flange purlins are overlapped, the outer edge line of the narrow flange 7 of one purlin and its rolled plate is wrapped around the curling edge of the wide flange 8 of the other purlin to the web 1. Therefore, in the present invention, the wide and narrow in the wide flange 8 and the narrow flange 7 mean that the distance between the curling edge of the wide flange 8 and the web 1 can wrap around the narrow flange 7. The part that can wrap around is wide, and the part that is wrapped around is narrow.

[0038] The cross-sectional length of the folded flange 3 is greater than the cross-sectional length of the initial flange 2, so that the folded flange 3 extends an extension 5 relative to the initial flange 2 and the bent portion of the web 1; the extension 5 is vertically bent and fits with the web 1; the extension 5 and the web 1 are connected without rivets, and the connection points 6 of the riveted connection are arranged at equal intervals along the length direction of the purlin. In addition, this embodiment can also be connected by welding or riveting.

[0039] In this embodiment, the angle between the two flanges and the directly connected curling edges 4 is 90 degrees, the angle between the folded flange 3 on the wide flange 8 side and the directly connected curling edges 4 is 135 degrees, and the angle between the folded flange 3 on the narrow flange 7 side and the directly connected curling edges 4 is 45 degrees. The height of the web 1 is 125 times its thickness; the side length of the extended edge 5 of the folded flange 3 is 16 mm; the spacing between the rivetless connection points 6 is 120 mm.

[0040] Embodiment 3:

[0041] A Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange, such as Figure 7 and Figure 8 As shown in the figure, a steel section with Z-shaped cross-section characteristics is formed by cold bending a flat steel plate with a thickness of 2.2 mm; the steel section includes a web 1, a wide flange 8 and a narrow flange 7; the wide flange 8 and the narrow flange 7 are orthogonally connected to the two ends of the web 1; the wide flange 8 and the narrow flange 7 are both double-layer flanges formed by folding the full flanges at both ends of the web 1; the double-layer flange includes a folded flange 3 and an initial flange 2, and the folded flange 3 is attached to the inner side or the outer side of the connected initial flange 2; a curling edge 4 is provided at one end of the double-layer flange away from the web 1; the curling edge 4 is bent more than twice to form a polygonal cavity, such as Figure 8 As shown, the curling edge of the wide flange 8 of this embodiment is a triangular cavity, and the curling edge of the narrow flange 7 is a closed curling edge inclined toward the web 1.

[0042] Referring to Example 1 Figure 3 As shown in the figure, when two identical Z-shaped double-flange purlins are overlapped, the outer edge line of the narrow flange 7 of one purlin and its rolled plate is wrapped around the curling edge of the wide flange 8 of the other purlin to the web 1. Therefore, in the present invention, the wide and narrow in the wide flange 8 and the narrow flange 7 mean that the distance between the curling edge of the wide flange 8 and the web 1 can wrap around the narrow flange 7. The part that can wrap around is wide, and the part that is wrapped around is narrow.

[0043] The cross-sectional length of the folded flange 3 is greater than the cross-sectional length of the initial flange 2, so that the folded flange 3 extends an extension 5 relative to the initial flange 2 and the bent portion of the web 1; the extension 5 is vertically bent and fits against the web 1; the extension 5 and the web 1 are connected by spot welding, and the connection points 6 of the riveted connection are arranged at equal intervals along the length direction of the purlin. In addition, this embodiment can also adopt rivetless or riveted connection.

[0044] In this embodiment, the width-to-thickness ratio of the wide flange 8 is 32, and the width-to-thickness ratio of the narrow flange 7 is 30. The angle between the two flanges and the directly connected curling edges 4 is 45 degrees, the angle between the folded flange 3 on the wide flange 8 side and the directly connected curling edges 4 is 90 degrees, and the angle between the folded flange 3 on the narrow flange 7 side and the directly connected curling edges 4 is 45 degrees. The height of the web 1 is 220 times its thickness; the side length of the extended edge 5 of the folded flange 3 is 18 mm; and the spacing between the spot welding connection points 6 is 150 mm.

[0045] Embodiment 4:

[0046] A Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange, such as Figure 7 and Figure 8 As shown in the figure, a steel section with Z-shaped cross-section characteristics is formed by cold bending a flat steel plate with a thickness of 2.2 mm; the steel section includes a web 1, a wide flange 8 and a narrow flange 7; the wide flange 8 and the narrow flange 7 are orthogonally connected to the two ends of the web 1; the wide flange 8 and the narrow flange 7 are both double-layer flanges formed by folding the full flanges at both ends of the web 1; the double-layer flange includes a folded flange 3 and an initial flange 2, and the folded flange 3 is attached to the inner side or the outer side of the connected initial flange 2; a curling edge 4 is provided at one end of the double-layer flange away from the web 1; the curling edge 4 is bent more than twice to form a polygonal cavity, such as Fig.10 As shown, the curling edges of the wide flange 8 and the narrow flange 7 of this embodiment are rectangular with symmetrical structure.

[0047] Referring to Example 1 Figure 3 and Figure 4 As shown, when two identical Z-shaped double-flange purlins are overlapped, the outer edge line of the narrow flange 7 of one purlin and its rolled plate is wrapped around the curling edge of the wide flange 8 of the other purlin to the web 1. Therefore, in the present invention, the wide and narrow in the wide flange 8 and the narrow flange 7 mean that the distance between the curling edge of the wide flange 8 and the web 1 can wrap around the narrow flange 7. The part that can wrap around is wide, and the part that is wrapped around is narrow.

[0048] The cross-sectional length of the folded flange 3 is greater than the cross-sectional length of the initial flange 2, so that the folded flange 3 extends an extension 5 relative to the initial flange 2 and the bent portion of the web 1; the extension 5 is vertically bent and fits against the web 1; the extension 5 and the web 1 are connected by spot welding, and the connection points 6 of the riveted connection are arranged at equal intervals along the length direction of the purlin. In addition, this embodiment can also adopt rivetless or riveted connection.

[0049] In this embodiment, the width-to-thickness ratio of the wide flange 8 is 32, and the width-to-thickness ratio of the narrow flange 7 is 30. The angle between the two flanges and the directly connected curling edges 4 is 90 degrees, and the angle between the two folded wide flanges 8 and the directly connected curling edges 4 is 90 degrees. The height of the web 1 is 140 times its thickness; the length of the vertical bending edge of the folded flange 3 is 18 mm; the spacing between the spot welding connection points 6 is 200 mm.

[0050] The above is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, makes any form of equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which does not depart from the content of the technical solution of the present invention and still falls within the protection scope of the present invention.

Claims

1. A Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange, characterized in that: The purlin is a Z-shaped cross-section steel formed by cold bending a flat steel plate; it includes a wide flange, a narrow flange and a web; the wide flange and the narrow flange are orthogonally connected to the two ends of the web; The wide flange and the narrow flange are both double-layer flanges formed by folding the full flanges at both ends of the web; the double-layer flange includes a folded flange and an initial flange, and the folded flange is attached to the inner side or the outer side of the connected initial flange; The double-layer flange is provided with a curling edge at one end away from the web; the curling edge is bent more than twice to form a polygonal cavity; When two identical Z-shaped double-flange purlins are overlapped, the outer edge of the narrow flange of one purlin and its rolled plate is wrapped around the area between the rolled edge of the wide flange of the other purlin and the web; The cross-sectional length of the folded flange is greater than the cross-sectional length of the initial flange, so that the folded flange extends an extension relative to the initial flange and the bent portion of the web; the extension is vertically bent and fits with the web; the extension and the web are fixedly connected by welding or riveting, and the welding or riveting connection points are arranged at equal intervals along the length direction of the purlin; The angle between the curling edge and the horizontal portion of the connected flange is 30 to 150 degrees; The width-to-thickness ratios of the wide flange and the narrow flange are different and are both less than or equal to 60.

2. The Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange according to claim 1, characterized in that: The length of the extended edge is greater than or equal to 10 mm; The distance between adjacent welding or riveting connection points is less than or equal to 300 mm.

3. The Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange according to claim 1, characterized in that: The height-to-thickness ratio of the web is less than or equal to 250.

4. The Z-shaped double-layer flange purlin with a reinforced cavity on the outer side of the flange according to claim 1, characterized in that: The surface of the web is provided with a plurality of grooves at equal intervals through groove processing.

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