Steel joint structure

Abstract

To provide a grooved joint plate excellent in manufacturability and capable of obtaining a high slip coefficient, and a steel material joint structure using the same.SOLUTION: A protrusion 13 is formed by a linear inclined surface. An angle formed by the linear inclined surface constituting the protrusion 13 is 60° to 120°. Here, if the base of the straight slope constituting the protrusion 13 is used as the reference plane, the protrusion 13 is on the tip side of the reference plane B, and the groove part 11 is on the base side of the reference plane B between the protrusions 13. The groove part 11 is formed in an arc shape as a whole with respect to the reference plane B. Here, when the width of the groove part 11 on the reference plane B is L2, L1 (protrusion pitch) / L2 (groove width) is 2 or more and 10 or less. Also, when the height of the protrusion 13 from the reference plane B is H1 and the depth of the groove part 11 from the reference plane B is H2, H1 / H2 is 3 or more and 15 or less.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a grooved joint plate and a steel material joint structure for connecting, for example, H-shaped steel beams. [Background technology]

[0002] Steel materials such as H-shaped steel can be joined together by high-strength bolt friction joints using splice plates. In this case, the splice plate is placed along both steel materials and fastened to them using high-strength bolts and nuts.

[0003] The strength of such a joint using high-strength bolt friction joints is ensured by the axial force applied to the high-strength bolt, the slip coefficient of the friction surfaces between the splice plate and the steel material, and the number of friction surfaces.

[0004] For this reason, the surface of the splice plate that comes into contact with the steel material is given red rust or shot blasted to ensure a specified coefficient of slip (for example, 0.45 in the "Standard Specification for Construction Works JASS6" compiled by the Architectural Institute of Japan).

[0005] However, in recent years, the strength required for joints has tended to increase due to the trend toward higher tensile strength and larger cross-section steel materials. Although it is possible to increase the strength by increasing the number of high-strength bolts, this comes with the problem of increased costs and labor.

[0006] On the other hand, if the slip coefficient of the friction surface is improved, the number of high-strength bolts can be prevented from increasing. Patent documents 1 and 2 describe examples of splice plates with grooves that have approximately triangular protrusions at a specified pitch in order to improve the slip coefficient. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 2936455 [Patent Document 2] Patent No. 3569758 Summary of the Invention [Problem to be solved by the invention]

[0008] It is believed that the sharper the tip of the protrusion of the grooved joint plate having the above-mentioned protrusion, the better it will bite into the H-shaped steel, but there is a limit to how sharp the tip of the protrusion can be made from a manufacturing standpoint. Even if the protrusion can be made sharp to a certain extent, if the rigidity of the protrusion is reduced, sufficient joint strength between steel materials cannot be obtained.

[0009] The present invention has been made in consideration of the above problems, and aims to provide a grooved joint plate that is easy to manufacture and has a high slip coefficient, and a steel joint structure using the same. [Means for solving the problem]

[0010] The first invention for solving the above-mentioned problems is, The grooved joint plate has a pair of steel members with ends butted against each other, and a grooved joint plate fixed to straddle the steel members. The grooved joint plate has a plurality of parallel projections arranged on only one surface, and a plurality of parallel grooves arranged between the projections. The projections are formed by a pair of inclined surfaces. In a cross section of the grooved joint plate in the thickness direction, the inclined surfaces are formed as straight lines. When a base of a straight line constituting the inclined surface of the projection is taken as a reference in a cross section of the grooved joint plate in the thickness direction, the groove is formed in an arc shape in the other surface direction with respect to the reference. When a distance between the tips of the projections is taken as L1 and a width of the groove at the reference is taken as L2 in a cross section of the grooved joint plate in the thickness direction, L1 / L2 is 2 or more and 10 or less, when the height of the protrusion from the reference is H1 and the depth of the groove from the reference is H2, H1 / H2 is 3 or more and 15 or less, a plurality of through holes are arranged in a direction perpendicular to the width direction in each of the vicinity of both ends in the width direction of the grooved joint plate, at least the one surface of the grooved joint plate is surface-treated, and the hardness of the one surface is at least twice as high as the hardness of the protrusion-forming surface of the material before the treatment, a pair of the steel materials are sandwiched between the one surfaces of the pair of the grooved joint plates, and the pair of steel materials are arranged so that the juxtaposition direction of the protrusions is the opposing direction of the steel materials, and the pair of steel materials are fixed with a plurality of bolts passed through the through holes, It is.

[0013] According to the first invention, The high slip coefficient allows for a steel joint structure that can reliably join steel materials together. Since the bottom of the groove is, for example, arc-shaped, when the grooved joint plate is fixed to the joint object with a bolt, stress concentration in the groove can be alleviated, and deformation and damage of the grooved joint plate can be suppressed.

[0014] In addition, since the ratio (L1 / L2) of the distance L1 between the tips of the protrusions to the width L2 of the groove on the reference surface is between 2 and 10, the groove width is not too narrow, which facilitates manufacturing and efficiently relieves stress concentration. Also, a sufficient number of protrusions can be arranged, resulting in a high slip coefficient.

[0015] In addition, since the ratio (H1 / H2) of the height H1 of the protrusion from the reference plane to the depth H2 of the groove from the reference plane is 3 or more, the protrusion can be reliably secured to bite into the steel material, and a high slip coefficient can be obtained. Furthermore, since the ratio (H1 / H2) is 15 or less, the height of the protrusion is not too high relative to the groove, and the rigidity of the protrusion is secured and processing is easy. In particular, if the angle formed by the linear inclined surfaces constituting the protrusion is 60° to 120°, manufacturability and rigidity can be both achieved. Furthermore, since the groove has a sufficient depth relative to the height of the protrusion, the groove can absorb the bulge formed on the surface of the steel material when the protrusion bites into the steel material.

[0016] In addition, by performing a surface treatment on the surface of the grooved joint plate on which the protrusions are formed, so that the hardness after the treatment is at least twice as high as the hardness of the steel material before the treatment, it is possible to achieve both workability during processing of the protrusions and rigidity of the protrusions during use. Note that the Vickers hardness before the treatment can be measured, for example, on a cross section obtained by cutting the grooved joint plate. Effect of the Invention

[0019] According to the present invention, it is possible to provide a grooved joint plate that is easy to manufacture and has a high slip coefficient, and a steel joint structure using the same. [Brief description of the drawings]

[0020] [Figure 1] 1A and 1B are perspective views showing a grooved joint plate 100. FIG. [Diagram 2] FIG. 3A is a diagram showing a steel joint structure 300 using a grooved joint plate 100, and FIG. 3B is a cross-sectional view of the joint portion. [Diagram 3] 1A is a cross-sectional view of a grooved joint plate 100 in the thickness direction, and FIG. 1B is an enlarged view of part A in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0022] (Grooved joint plate 100) 1(a) and 1(b) are diagrams showing a grooved joint plate 100 according to a first embodiment of the present invention, and the two differ only in the direction in which the protrusions 13 (grooves 11) are formed. The grooved joint plate 100 is a so-called splice plate, and is used, for example, when joining the web or flange of an H-shaped steel.

[0023] A grooved joint plate 100, which is a plate-shaped member, has a plurality of projections 13 arranged in parallel on at least one surface that contacts the joint object. That is, grooves 11 are formed in parallel between adjacent projections 13. Also, a plurality of through holes 12 for passing high-strength bolts are formed.

[0024] For example, in the example shown in FIG. 1(b), the through holes 12 are arranged in two rows near both ends of the grooved joint plate 100 in the width direction (direction perpendicular to the formation direction of the protrusions 13). In this case, the through holes 12 may be arranged in a line in the juxtaposition direction of the protrusions 13 as shown in the figure, or adjacent through holes 12 may be arranged in a staggered manner with mutual deviation in the direction along the protrusions 13 (direction perpendicular to the width direction). By aligning the through holes 12 in the width direction, the length of the grooved joint plate 100 can be shortened, and by arranging the through holes 12 in a staggered manner, the width of the grooved joint plate 100 can be narrowed. The number and arrangement of the through holes 12 are not limited to the example shown in the figure.

[0025] FIG. 2(a) is a diagram showing a steel material joint structure 300 in which steel materials to be joined are joined together using a grooved joint plate 100, and FIG. 2(b) is a cross-sectional view of the joint. The grooved joint plate 100 is used, for example, when joining webs or flanges (hereinafter referred to as flanges, etc.) of H-shaped steel 200 (steel material) to be joined in a steel beam. The ends of a pair of H-shaped steel 200 are butted against each other, and the grooved joint plate 100 is arranged so as to straddle the flanges, etc. of the adjacent H-shaped steel 200, and is fixed to both flanges, etc. using high-strength bolts 101, nuts 102, etc. Note that the grooved joint plate 100 used for joining the web and the grooved joint plate 100 used for joining the flanges may differ in the formation direction of the protrusions 13 relative to the formation direction of the through holes 12.

[0026] For example, metal plates made of rolled steel for general structure, rolled steel for architectural structure, rolled steel for welded structure, carbon steel for mechanical structure, alloy steel for mechanical structure, etc. are used for the grooved joint plate 100. The total thickness of the two grooved joint plates 100 that sandwich the steel material is set according to the thickness of the objects to be joined, and is set, for example, so that the total thickness of the grooved joint plate 100 is equal to or greater than the thickness of a flange or the like.

[0027] The grooved joint plate 100 shown in Fig. 1(b) is used, for example, to join webs together. In this case, the direction in which the grooves 11 (protrusions 13) are formed is approximately perpendicular to the butt direction (i.e., joining direction) of the H-shaped steel 200. Therefore, by sandwiching the grooved joint plate 100 from both sides of the web and fastening the high-strength bolts 101, the tips of the protrusions 13 are forced into the web, and thus, even if a tensile force is generated in the joint between the H-shaped steel 200, slippage between the grooved joint plate 100 and the H-shaped steel 200 is unlikely to occur, and the H-shaped steel 200 can be reliably joined together.

[0028] Next, the protrusions 13 and grooves 11 of the grooved joint plate 100 will be described in detail. Fig. 3(a) is a diagram showing a cross section in the thickness direction of the grooved joint plate 100, and Fig. 3(b) is an enlarged view of part A in Fig. 3(a). As described above, the protrusions 13 and grooves 11 are alternately formed on one surface (referred to as the protrusion forming surface 111) of the grooved joint plate 100.

[0029] The protrusions 13 are substantially isosceles triangles (including equilateral triangles), and the distance between the tips of the protrusions 13 is L1 (see FIG. 3(b)). That is, the protrusions 13 and the grooves 11 are arranged at a uniform pitch L1. The pitch L1 of the protrusions 13 is preferably about 0.1 mm to 3.0 mm, and more preferably 0.5 mm to 2.0 mm.

[0030] The protrusions 13 are formed by linear inclined surfaces. The angle between the linear inclined surfaces constituting the protrusions 13 is 60° to 120°. If the angle is too small, the rigidity of the protrusions 13 decreases. If the angle is too large, the protrusions 13 become difficult to bite into the steel material, and the width of the protrusions 13 increases, so the number of protrusions 13 decreases and the coefficient of slip for the steel material decreases.

[0031] Here, if the base of the linear inclined surface constituting the protrusion 13 (for example, the change point of the inclination angle) is taken as the reference plane (B in the figure), the tip side (upper in the figure) of the reference plane B is the protrusion 13, and the base side (lower in the figure) of the reference plane B between the protrusions 13 is the groove 11. That is, the groove 11 is not formed on the extension line of the inclined surface of the protrusion 13, but is formed at an angle different from the inclination angle of the protrusion 13. Therefore, the groove 11 is formed at the base of the inclined surface of the protrusion 13, between the change points of the inclination angle. The groove 11 is formed, for example, in an arc shape as a whole with respect to the reference plane B. Note that the groove 11 does not have to be completely arc-shaped, and may be formed, for example, in a polygonal shape in which straight lines of a plurality of different angles are continuous. That is, it is sufficient if the groove 11 is approximately arc-shaped as a whole.

[0032] Here, when the width of the groove 11 on the reference plane B is L2 (see FIG. 3(b)), L1 (projection pitch) / L2 (groove width) is set to 2 or more and 10 or less. For example, if the tip angle of the projection 13 is constant and L1 / L2 is less than 2, the width of the groove 11 becomes too wide, the number of projections 13 decreases, and it is difficult to ensure a high slip coefficient. On the other hand, if the width of the groove 11 is constant and L1 / L2 is less than 2, the projection 13 becomes too thin and sharp, and the rigidity of the projection 13 decreases. Also, if the angle of the projection 13 is constant and L1 / L2 exceeds 10, the width of the groove 11 becomes too narrow, which deteriorates manufacturability and reduces the effect of relaxing the stress concentration in the groove 11. On the other hand, if the width of the groove 11 is constant and L1 / L2 exceeds 10, the number of projections 13 decreases, and it is difficult to ensure a high slip coefficient.

[0033] 3(b), when the height of the protrusion 13 from the reference plane B is H1 and the depth of the groove 11 from the reference plane B is H2, H1 / H2 is set to be equal to or greater than 3 and equal to or less than 15. If H1 / H2 is less than 3, the height of the protrusion 13 becomes too low, making it impossible to ensure a sufficient amount of penetration into the steel material.

[0034] Furthermore, if H1 / H2 exceeds 15, the height of the protrusion 13 becomes too high, resulting in insufficient rigidity of the protrusion 13 and excessive penetration into the steel material, requiring a greater tightening force. Furthermore, if the depth of the groove 11 becomes too small, the stress relaxation effect decreases and it becomes difficult for the groove 11 to absorb the deformed portion of the steel material (the bulge caused by the penetration of the protrusion 13) when the protrusion 13 is penetrated into the steel material.

[0035] The surface layer of the protrusion-forming surface 111 on at least one side of the grooved joint plate 100 has been subjected to a surface treatment (e.g., nitriding treatment, etc.), and has a harder hardness than the flanges of the H-shaped steel 200 to be joined. Here, it is desirable that the hardness (e.g., Vickers hardness) of the protrusion-forming surface 111 after the surface treatment is at least twice as hard as the protrusion-forming surface of the material before the treatment. The Vickers hardness of the protrusion-forming surface of the material before the treatment can be measured in the cross section of the grooved joint plate 100, near the protrusion-forming surface, excluding the surface-treated portion.

[0036] Such a grooved joint plate 100 can be manufactured by, for example, the method disclosed in JP 2018-164956 A. According to this method, the tip of the protrusion 13 can be sharpened, and the groove 11 can be easily formed into an arc shape.

[0037] As described above, in this embodiment, by forming the projections 13 in a shape that satisfies specific conditions, when steel materials are joined using this, the projections 13 can be securely inserted into the steel materials to obtain a high slip coefficient. In addition, no stress concentration occurs in the grooves 11, making manufacturing easy.

[0038] Furthermore, by carrying out a surface treatment to make the surface layer of the projection forming surface 111 at least twice as hard as the steel material to be joined, the tips of the projections 13 can be caused to bite into the steel material, providing an anti-slip effect.

[0039] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the above examples. It is clear that a person skilled in the art can come up with various modified or altered examples within the scope of the technical ideas disclosed in this application, and it is understood that these also naturally belong to the technical scope of the present invention. [Explanation of symbols]

[0040] 11...Groove 12...Through hole 13....Protrusion 14……Flat area 100……Grooved joint plate 101………High strength bolt 102………Nut 111……Protrusion forming surface 200……H-beam steel 300……Steel joint structure

Claims

[Claim 1] A pair of steel members having ends butted together; A grooved joint plate is fixed so as to span the steel materials, The grooved joint plate is A plurality of projections are provided in parallel on only one surface, and a plurality of grooves are provided in parallel between the projections, The protrusion is formed by a pair of inclined surfaces, and in a cross section in the thickness direction of the grooved joint plate, the inclined surfaces are formed as straight lines, In a cross section in the thickness direction of the grooved joint plate, when a base of a straight line constituting the inclined surface of the protrusion is used as a reference, the groove is formed in an arc shape in the other surface direction with respect to the reference, In the cross section of the grooved joint plate in the thickness direction, when the distance between the tips of the protrusions is L1 and the width of the groove portion in the reference is L2, L1 / L2 is 2 or more and 10 or less, When the height of the protrusion from the reference point is H1 and the depth of the groove from the reference point is H2, H1 / H2 is equal to or greater than 3 and equal to or less than 15, A plurality of through holes are arranged in a direction perpendicular to the width direction near both ends of the grooved joint plate in the width direction, At least one surface of the grooved joint plate is subjected to a surface treatment, the hardness of said one surface is at least twice as high as the hardness of the protrusion-forming surface of the material before treatment; A steel material joining structure characterized in that a pair of the steel materials are sandwiched between one surface of a pair of the grooved joining plates, the protrusions are arranged so that the adjacent directions of the steel materials are in the opposing directions, and each of the pair of steel materials is fixed with a plurality of bolts passed through the through holes.

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