JP6551167B2 - Butt weld joint structure, joint structure, structure and joining method - Google Patents

Description

  The present invention relates to, for example, a butt-welded joint structure forming a butt-welded joint of a column used for non-diaphragm connection of a beam-to-column joint of a steel structure, and a joint structure having the butt-welded joint structure The present invention relates to a structure having a welded joint structure or a connection structure and a joining method.

  Conventionally, a diaphragm or a rib is omitted by using a joint member having a cross section thicker than that of a main member such as a pillar at a node where the members such as a joint of a column and a beam and a truss frame crosses a steel structure The streamlined structure is widely adopted. In the case of adopting such a structure, the size (side length) of the outer shape of the main member such as a column and the submember such as a beam is often the same. As an example of this structure, there is a non-diaphragm connection of a beam-to-column joint.

  Conventional non-diaphragm fittings are those using cast steel for thick-walled joint pipes (for example, see Patent Document 1) or those using square steel pipes by welding assembly (for example, see Patent Document 2). ) Etc. are known. Further, as a structure for joining steel pipes having different corner dimensions, for example, a square steel pipe having a curvature at the corner of the cross section, a structure as shown in Patent Document 3 is known. Patent document 3 joins two main members which consist of a square steel pipe via the square steel pipe which has the same side length as a main member, and is thicker than a main member.

  In Patent Document 1 described above, details of the welded portion between the column and the joint metal are not disclosed, and the configuration method of the groove such as the groove shape and the backing metal is unknown. Further, in Patent Document 2 described above, a backing metal protruding from the end face of the steel pipe is attached to the thinner steel pipe of the thickness, and the end face of the welded assembly steel pipe having a thicker thickness facing the back metal. It is disclosed that the construction of the groove is applied to. In the above-mentioned Patent Document 3, as in Patent Document 2, a backing metal protruding from the end surface of the steel pipe is attached to the square steel pipe having the smaller thickness, and the backing metal having the larger thickness is opposed to the backing metal. It is disclosed that the groove is formed on the end face of a rectangular steel pipe.

Japanese Patent Application Laid-Open No. 2003-82761 JP 2010-106515 A JP, 2014-224377, A

  According to the conventional method of forming the groove shown in the above-mentioned Patent Document 2 or 3, the cross section of the thinner steel pipe crosses the entire cross section of the thicker square steel pipe for the two rectangular steel pipes to be joined. If it is not completely covered over the circumference, a gap will occur in the groove and welding can not be performed.

  Further, as in Patent Document 3 above, by defining the relationship between the corner dimensions of the two rectangular steel pipes to be joined, the cross section of the steel pipe with the thinner plate thickness is changed to the cross section of the steel pipe with the thicker plate thickness. Even when it is completely included over the entire circumference, if the inner peripheral surfaces of the two steel pipes are flush with each other, there is a concern that welding defects may occur due to welding metal being melted from the inside of the groove. Is done. In addition, since square steel pipes are industrial products, they have variations in size and shape, so that the nominal cross section of the thinner steel pipe section is completely included in the thicker steel pipe cross section. Even if planned, there is a concern that a gap may occur in the groove in real.

  Such a problem may also occur when a square steel pipe having a smaller thickness has a cross-sectional corner having a curvature, and a square steel pipe having a thicker thickness has a right angle. That is, the thinner steel pipe section is not completely included in the thicker steel pipe section, and a gap may occur.

  Further, the above problem occurs not only in non-diaphragm connections but also in butt welding of square steel pipes having substantially the same side length in cross section and different corner dimensions. For example, when a cold roll formed square steel pipe BCR 295 having a nominal diameter of 300 mm and a nominal thickness of 22 mm is butted against a hot formed square steel pipe BSH 325 having a nominal diameter of 300 mm and a nominal thickness of 25 mm, The tolerance of ± 3 mm can cause 6 mm discrepancies in the most severe combinations.

  Also, even if each steel pipe has a side length and thickness tolerance of 0 mm, the corner radius of BCR295 is the smallest radius within the range of intersection, the outer radius is 3.0 times the plate thickness, and the inner radius is Even when the thickness is 2.0 times and the radius inside the corner of BSH 325 is 1.0 times the thickness without intersection, the inner surface of BCR 295 is positioned 3.6 mm inside the inner surface of BSH 325.

This will be specifically described with reference to FIG. As shown in the corner model of FIG. 17, a point P is a corner when the cross section is assumed to be a square of 300 mm × 300 mm. As shown in FIG. 17 (1), the distance from the point P to the center Q of the corner inner surface of the BCR295 (dimension 300mm × 300mm, plate thickness 22mm) is L1, and as shown in FIG. If the distance from P to BSH325 (dimensions 300mm x 300mm, plate thickness 25mm) from the corner center inner surface Q is L2,
L1 = (2 ^1/2 −1) × 3 × 22 + 22 = 49.3mm
L2 = 2 ^1/2 × 25 + (2 ^1/2 −1) × 25 = 45.7mm
The inner surface of BCR295 is farther from point P than the inner surface of BSH325 (inward), and the difference is 3.6 mm.

  For this reason, in a structure in which square steel pipes having different corner dimensions are butt-welded, the steel pipe cross section with the thinner plate thickness is not completely included in the steel pipe cross section with the thicker plate thickness, or is completely included. Even when the inner peripheral surfaces of two steel pipes are flush with each other, there has been a demand for a structure that can be butt welded reliably without the occurrence of welding defects due to welding metal being melted from the groove.

  The present invention has been made in view of the above, and has a butt-welded joint structure, joint structure, structure, and joint capable of reliably butt-welding square steel pipes having different corner sizes without welding defects. Intended to provide a method.

  In order to solve the above-described problems and achieve the object, the butt welded joint structure according to the present invention is formed by butt welding square steel pipes having substantially the same cross-sectional side length and different plate thickness and corner dimensions. A joint structure, which is attached to the inner surface of the end of one square steel pipe and protrudes toward the end of the other square steel pipe, and the inner surface of the end of the other square steel pipe It has a second backing metal attached, and is characterized by butt welding of the contact part of the first backing metal and the second backing metal.

  Further, in the butt weld joint structure according to the present invention, in the above-described invention, the inner side surface of the square steel pipe having the thicker plate thickness is more than the inner side surface of the square steel pipe having the thinner plate thickness. Is also located outside the cross section, and the discrepancy dimension of the inner surface of the corners of these two square steel pipes is set to a value that satisfies either of the following (1) or (2) I assume.

(1) When the plate thickness of the square steel pipe having the smaller plate thickness is 15 mm or less, the misalignment dimension is set to 3.0 mm or less.
(2) When the plate thickness of the square steel pipe having the smaller plate thickness exceeds 15 mm, the misalignment dimension is set to 6.0 mm or less and 1/5 or less of the plate thickness.

  Another butt-welded joint structure according to the present invention is characterized in that, in the above-described invention, the thicker square steel pipe is a hot-formed square steel pipe.

  The connection structure according to the present invention is characterized by having the above-mentioned butt-welded joint structure.

  Further, a structure according to the present invention is characterized by having the butt weld joint structure or the joint structure described above.

  The joining method according to the present invention is a joining method in which square steel pipes having substantially the same side length in cross section and different plate thicknesses and corner dimensions are butt-welded, and the inner side surface of the end of one square steel pipe A first backing metal protruding toward the end of the other square steel pipe and a second backing metal attached to the inner surface of the end of the other square steel pipe. It is characterized in that square steel pipes are butt welded with the two backing metal plates in contact.

  According to the butt-welded joint structure according to the present invention, the joint structure is formed by butt-welding square steel pipes having substantially the same side length in cross section and different plate thicknesses and corner portions, and one end of one square steel pipe Has a first backing metal attached to the inner surface of the base and protruding toward the end of the other square steel pipe, and a second backing metal attached to the inner surface of the other square steel pipe end Since the abutting part of the first backing metal and the second backing metal are butt welded, the cross section of the square steel pipe with the thinner plate thickness is the entire cross section of the square steel pipe with the thicker plate thickness. Even if it is not completely included, or even if it is completely included, but the inner surfaces of the two rectangular steel pipes are flush with each other, the first and second backing metal respectively attached to the rectangular steel pipes By making butt welding in contact, it is possible to create gaps in the groove It is possible to prevent the deer. For this reason, according to the present invention, it is possible to reliably butt-weld without welding defects such as welding-off of the weld metal from the inside of the groove.

  In addition, by applying the butt weld joint structure according to the present invention to the joint structure, the details around the joint are simplified, and the effect of facilitating maintenance from the outside is achieved.

FIG. 1 is a transverse sectional view showing Embodiment 1 of the butt-welded joint structure according to the present invention, and is a diagram showing an overlapping state of cross sections of a square steel pipe to be butt welded. FIG. 2 is a view showing an example of attaching a backing metal to a square steel pipe according to Embodiment 1 of the present invention, (1) is a cross-sectional view of the tip of the square steel pipe having a smaller plate thickness, (2 ) Is a cross-sectional view of the end of the thicker square steel pipe. FIG. 3 is a side cross-sectional view before welding along the line AA of FIG. FIG. 4 is a side sectional view before welding along the line B-B of FIG. FIG. 5 is a side view before welding as viewed from the direction along the line AA of FIG. 6 is a side view before welding as viewed from the direction along the line B-B of FIG. FIG. 7 is a side sectional view after welding along the line AA of FIG. FIG. 8 is a side cross-sectional view after welding taken along the line B-B of FIG. FIG. 9 is a transverse sectional view showing Embodiment 2 of the butt weld joint structure according to the present invention, and is a diagram showing an overlapping state of the cross sections of the square steel pipes to be butt welded. FIG. 10 is a view showing an example of attaching a backing metal to a square steel pipe according to Embodiment 2 of the present invention. (1) is a cross-sectional view of the tip of the square steel pipe having a smaller plate thickness, (2 ) Is a cross-sectional view of the end of the thicker square steel pipe. FIG. 11 is a side sectional view before welding along the line AA of FIG. FIG. 12 is a side cross-sectional view before welding along the line B-B in FIG. FIG. 13 is a side view before welding as viewed from the direction along the line AA of FIG. FIG. 14 is a side view before welding as viewed from the direction along the line B-B of FIG. 9. FIG. 15 is a side cross-sectional view after welding taken along the line AA of FIG. FIG. 16 is a side sectional view after welding taken along the line B-B of FIG. FIG. 17 is a view showing a corner model, (1) is a corner model of BCR 295, and (2) is a corner model of BSH 325.

  Hereinafter, embodiments of a butt-welded joint structure, a connection structure, a structure and a joining method according to the present invention will be described in detail based on the drawings. The present invention is not limited by the embodiment.

First Embodiment
First, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a cross-sectional view of the butt welded joint structure according to the first embodiment. As shown in this figure, in a joint structure in which rectangular steel pipes 1 and 2 having the same side length in cross section but different thickness and curvature of corner parts are butt-welded together, Depending on the combination, the inner side surface 1a of the thinner square steel pipe 1 may come inward than the inner side surface 2a of the thicker square steel pipe 2. In the example of FIG. 1, the cross section corner corresponds to this case. At this time, when the end of the thinner square steel pipe 1 is re-bent to make it face the end of the thicker square steel pipe 2, a gap is formed at the corner of the cross section in the groove. It will occur.

  Therefore, in the first embodiment, as shown in FIG. 2 (1) and FIG. 3, a plate is formed on the entire circumference of the inner side surface 1 a of the end of the thinner square steel pipe 1 (one square steel pipe). Attach a backing metal 3a (first backing metal) projecting toward the end of the thicker rectangular steel pipe 2 (the other rectangular steel pipe). On the other hand, as shown in FIG. 2 (2) and FIG. 4, a backing metal 3 b (second backing metal) is attached around the corner of the inner side surface 2 a of the end of the square steel pipe 2. The tip end face of the backing metal 3b is flush with the tip end face of the square steel pipe 2.

  Then, as shown in FIG. 3 and FIG. 4, the tip end surface of the backing metal 3a around the corner and the tip surface of the backing metal 3b are in contact with each other, but the square steel pipes 1, 2 are butted to form the groove 4 Weld. Thereby, the butt weld joint structure of Embodiment 1 as shown in the side cross sectional views of FIGS. 7 and 8 is obtained. In addition, the code | symbol 6 in FIG. 7 and FIG. 8 has shown the weld metal.

  Here, if it is assumed that there is no backing metal 3b as shown in FIG. It is sufficient to attach the backing metal 3b only to a corner portion where a particularly large gap is generated. However, the present invention is not limited to this, and may be attached to the entire inner surface 2a, for example.

  5 and 6 are side views before welding as seen from directions along the lines AA and BB in FIG. 1, respectively. As shown in these drawings, the presence of the backing metal 3b (not shown) on the inner side surface 2a of the corner portion of the thicker square steel pipe 2 can prevent a gap from occurring in the groove. . In addition, the code | symbol 5 in FIG. 5 and FIG. 6 has shown the beveling surface.

  Thus, according to the first embodiment, even if the cross section of the square steel pipe 1 with the smaller plate thickness is not completely included in the cross section of the square steel pipe 2 with the thicker plate thickness over the entire cross section, the square steel pipe. By abutting the square steel pipes 1 and 2 with the backing metal 3a and the backing metal 3b attached respectively to 1 and 2 in abutment, generation of a gap in the groove 4 can be prevented, so from within the groove 4 It is possible to reliably butt-weld the square steel pipes 1 and 2 while avoiding the occurrence of welding defects due to the melting of the weld metal 6 and the like.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 9 shows a cross-sectional view of the butt-welded joint structure according to the second embodiment. As shown in this figure, even in the case of a joint structure in which the square steel pipe 2 having the same side length and having the right angled corner and the square steel pipe 1 having the curvature at the corner are butt-welded, In some cases, the inner side surface 1a of the inner wall 1a may be inward of the inner side surface 2a of the thicker rectangular steel pipe 2. In the example of FIG. 9, the cross section corner corresponds to this case.

  Therefore, as in the case of the first embodiment, the backing metal 3b is arranged at the corner of the inner side surface 2a at the end of the thicker square steel pipe 2. In this way, since the gap in the groove can be closed, reliable butt welding is possible.

  More specifically, as shown in FIG. 10 (1) and FIG. 11, the square steel pipe 2 having the thicker thickness is formed on the entire inner surface 1a of the end of the square steel pipe 1 having the thinner thickness. A backing metal 3a protruding toward the end is attached. On the other hand, as shown in FIG. 10 (2) and FIG. 12, the backing metal 3 b (second backing metal) is attached to the corner of the right side of the inner side surface 2 a of the end of the square steel pipe 2. The backing metal 3 b is in the shape of a prism extending along a right-angled corner of the square steel pipe 2, and the tip surface thereof is flush with the tip surface of the square steel pipe 2.

  Then, as shown in FIGS. 11 and 12, the groove 4 is welded by abutting the square steel pipes 1 and 2 with the tip surface of the backing metal 3a and the tip surface of the backing metal 3b at the corners in contact with each other. To do. Thereby, the butt-welded joint structure of the second embodiment as shown in the side sectional views of FIGS. 15 and 16 is obtained. In addition, the code | symbol 6 in FIG. 15 and FIG. 16 has shown the weld metal.

  13 and 14 are side views before welding, as viewed from the direction along the lines AA and BB in FIG. 9, respectively. As shown in these drawings, the presence of the backing metal 3b (not shown) on the inner side surface 2a of the corner portion of the thicker square steel pipe 2 can prevent a gap from occurring in the groove. . In addition, the code | symbol 5 in FIG. 13 and FIG. 14 has shown the beveling surface.

  As described above, according to the second embodiment, when the square steel pipe 2 having the right angled corner and the square steel pipe 1 having the curvature at the corner are butt-welded, the cross section of the thinner square steel pipe 1 is a plate Even if the cross section of the thicker square steel pipe 2 is not completely included over the entire cross section, the square steel pipes 1 and 2 are brought into contact with the backing metal 3a and the backing metal 3b attached to the square steel pipes 1 and 2, respectively. Can prevent gaps from forming in the groove 4, thereby avoiding the occurrence of welding defects due to the weld metal 6 being melted from the groove 4, and ensuring both the square steel pipes 1 and 2. Can be butt-welded.

[Embodiment 3]
Next, a third embodiment of the present invention will be described. In the third embodiment, in the butt welded joint structures of the first and second embodiments, the offset dimensions at the corner portions of the square steel pipes 1 and 2 are set based on the value of the predetermined range defined in the law. Is.

  According to the law, discrepancies between butt-welded joints are in principle required to satisfy the following requirements (a) and (b) (see Reference 1 below).

(A) When the plate thickness of the square steel pipe having the smaller plate thickness is 15 mm or less, the misalignment dimension is 1.5 mm or less.
(B) When the plate thickness of the square steel pipe having the smaller plate thickness exceeds 15 mm, the discrepancy dimension is set to 3.0 mm or less and 1/10 or less of the plate thickness.

[Reference 1] “Matters for determining the structure of steel-frame joints or joints”, Ministry of Construction Notification No. 1464, May 31, 2000

  Therefore, in the third embodiment, as shown in FIGS. 1 and 9, the inner side surface 2a of the corner of the thicker square steel pipe 2 is the corner of the thinner square steel pipe 1. Of the inner side surfaces 1a and 2a of the corners of these two rectangular steel pipes 1 and 2 are positioned at the cross-sectional outside of the inner side surface 1a of one of the following two (1) and (2) The value was set to satisfy.

(1) When the plate thickness of the square steel pipe 1 having the smaller plate thickness is 15 mm or less, the misalignment dimension is set to 3.0 mm or less.
(2) When the thickness of the thinner square steel pipe 1 exceeds 15 mm, the deviation dimension is set to 6.0 mm or less and 1⁄5 or less of the thickness.

  Here, the above (1) and (2) are set based on the above-mentioned requirements (a) and (b) defined in the law.

  According to the butt-welded joint structure of the third embodiment, the desired axial stress can be obtained by setting the discrepancy dimension at the corners of the square steel pipes 1 and 2 based on a predetermined range of values stipulated by law. Can be borne or transmitted.

  In particular, even in the case where a gap is generated in the groove 4 of the cross-sectional corner without the backing metal 3b, the inner side surface 1a of the square steel pipe 1, 2 as shown in the first and second embodiments. By arranging the backing metals 3a and 3b on 2a and setting the offset dimensions to the limit values shown in the above (1) and (2), it is possible to bear or transmit the desired axial stress. It is.

[Modification of Embodiments 1 to 3]
In said Embodiment 1-3, you may comprise the square steel pipe 2 with thicker plate | board by a hot forming square steel pipe.

  In addition, the butt weld joint structure of the first to third embodiments described above may be applied to the connection structure. In this way, the detail around the joint becomes simple and maintenance from the outside becomes easy. Furthermore, the butt-welded joint structure of the first to third embodiments or the connection structure described above can be applied as a joint or connection used in a structure such as a steel structure. In this case, for example, the butt welded joint structures of the first to third embodiments may be used for a butt welded joint for a column used for a non-diaphragm joint of a column beam joint portion of a steel structure.

  As described above, according to the butt-welded joint structure according to the present invention, the joint structure is formed by butt-welding square steel pipes having substantially the same side length in cross section and different plate thicknesses and corner portions, Attach the first backing metal protruding toward the end of the other square steel pipe to the inner side of the end of the square steel pipe, and attach the second backing metal to the inner side of the end of the other square steel pipe Since the first steel back plate and the second steel back plate are in contact with each other, but the square steel pipes are butt-welded, the cross section of the thinner steel pipe cross section is the cross section of the thicker steel pipe cross section The first backing metal and the second backing attached to the square steel pipe, respectively, even if they are not completely contained over the entire circumference, or even if they are completely contained but the inner surfaces of the two square steel pipes are flush with each other. By butt welding with the latch in contact , It is possible to prevent the gap is formed in the GMA. For this reason, according to the present invention, butt welding can be reliably performed without welding defects due to melting of the weld metal from the inside of the groove or the like.

  Further, it is possible to transmit a desired axial stress by setting the offset dimension at the corner of the square steel pipe based on the value of the predetermined range defined in the law.

  Further, by applying the butt weld joint structure according to the present invention to the joint structure, the detail around the joint becomes simple and maintenance from the outside becomes easy.

  As described above, the butt-welded joint structure, joint structure, structure and joining method according to the present invention butt-weld square steel pipes having substantially the same cross-sectional side length and different plate thicknesses and corner dimensions. In particular, it is suitable for reliably butt welding square steel pipes together without welding defects.

1 Square steel pipe (one square steel pipe)
1a inner surface 2 square steel pipe (the other square steel pipe)
2a inner surface 3a backing metal (first backing metal)
3b Backing gold (second backing gold)
4 groove 5 groove surface 6 weld metal

Claims (6)

A joint structure formed by butt welding two square steel pipes having substantially the same side length in cross section and different plate thickness dimensions and corner curvature dimensions,
Attached to the inner surface of the end portion of the thickness of the thinner square tube, a first backing strip projecting toward the end portion of the plate thickness thicker square tube, plate thickness thicker RHS of It has a second backing metal attached to the inner surface of the corner of the end, the first backing metal and the second backing metal are in contact, and butt-welded rectangular steel pipes Butt welded joint structure characterized by that. The inner surface of the corner portion of the thicker square steel pipe is located on the outer side of the cross section than the inner surface of the corner portion of the thinner square steel pipe, and the corner portions of these two square steel pipes The butt-welded joint structure according to claim 1, characterized in that the staggering dimension of the inner surface of the is set to a value satisfying any of the following (1) and (2).
(1) When the plate thickness of the square steel pipe having the smaller plate thickness is 15 mm or less, the misalignment dimension is set to 3.0 mm or less.
(2) When the thickness of the thinner square steel pipe exceeds 15 mm, the deviation dimension is 6.0 mm or less and 1⁄5 or less of the thickness.   The butt-welded joint structure according to claim 1 or 2, wherein the thicker square steel pipe is made of a hot-formed square steel pipe.   A joint structure comprising the butt weld joint structure according to claim 1.   A structure having the butt weld joint structure according to any one of claims 1 to 3 or the connection structure according to claim 4. It is a joining method in which square steel pipes having substantially the same side length in cross section and different plate thickness dimensions and corner curvature dimensions are butt welded,
The inner surface of the end portion of the thickness of the thinner square tube, is attached to a first backing strip projecting toward the end portion of the plate thickness thicker square tube, plate thickness thicker RHS of A second backing metal is attached to the inner surface of the corner of the end, and the first steel backing and the second metal backing are brought into contact with each other to butt-weld the square steel pipes.

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