Joint member

Abstract

To provide a steel pipe joint structure which can be easily constructed with high quality without forming an opening in a steel pipe, and a joint member used in the same.SOLUTION: A first frame 5 and a second frame 6 are connected to each other through a connection plate 7 in a state where an end face of the first frame 5 fixed to the end of a first steel pipe 2 and an end face of the second frame 6 fixed to the end of a second steel pipe 3 are abutted on each other. The connection plate 7 has one end fixed to the first frame 5, and the other end spliced to the inner surface of the second frame 6. The first frame 5 and the second frame 6 are fixed to each other through the connection plate 7 by screw-fitting a bolt 8 penetrating a through hole 62 formed in the second frame 6 to the connection plate 7.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a connecting member for connecting steel pipes to each other. successive

Background Art

[0002] In the construction of steel pipe piles, steel pipe sheet piles, and steel frame structures, steel pipes may be connected axially. In joining steel pipes, it is common to weld the end faces of the steel pipes in contact with each other. However, on-site welding work requires time and effort for ensuring the working environment and quality inspection. Also, skilled techniques are required to ensure quality.

[0003] On the other hand, Patent Document 1 discloses a joint structure for connecting steel pipes by attaching a plate material across the outer and inner surfaces of a pair of steel pipes with their end faces in contact, and fastening high-strength bolts that penetrate both plate materials and the steel pipes.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the joint structure of Patent Document 1, since bolts are used to fix the plate materials to both steel pipes, the work of fastening a large number of bolts is time-consuming. Also, when attaching the plate material inside the steel pipe or fastening the bolts, it is necessary to provide an opening in the steel pipe for passing an arm inside the steel pipe, so there is a concern about a decrease in the strength of the steel pipe. Furthermore, although through holes for inserting bolts are formed in the steel pipe, it is common to form through holes with a large inner diameter relative to the shaft diameter of the bolts so as to absorb misalignment caused by construction errors or the like. On the other hand, when adding a plurality of steel pipes to form a structure of a predetermined length, there is a concern that the accumulated misalignment may increase.​

[0006] The present invention aims to propose a joint member that can be constructed simply and with high quality without forming an opening in a steel pipe. successive

Means for Solving the Problem

[0008] To solve such problems The joint member of the present invention includes a pair of frames (a first frame and a second frame) that are connected in a state where their end faces are butted against each other, a plurality of connecting plates having one end fixed to one of the frames (the first frame) and the other end abutting against the inner surface of the other frame (the second frame), and bolts that penetrate the other frame and are screwed into the connecting plates.

[0009] According to such a joint member, since the bolts are screwed onto the connecting plates, it is not necessary to form an opening in the steel pipe. Further, it is not necessary to form through holes for bolts in the steel pipe, and cross-sectional defects do not occur in the steel pipe. Therefore, the strength of the steel pipe does not decrease. Also, since the connecting plates are fixed to the first frame in advance, the bolts are only used for joining the connecting plates and the second frame, so the labor required for on-site work can be reduced. The first frame, the second frame, and the connecting plates are formed in a factory or the like and fixed to the steel pipe, so the desired quality is ensured. successive

[0010] The connecting plate to which the bolts are screwed may be formed with bolt holes that are thread-formed corresponding to the positions of the through holes of the second frame, or a second through hole may be formed corresponding to the position of the through hole of the second frame and a nut communicating with the second through hole may be fixed.

[0011] ​​By welding and integrating the bearing plate to the second frame, the thickness of the through-hole in the second frame can be increased, and the hole bearing pressure of the bolt can be increased. It is desirable that the surface of the bearing plate on the frame side is a curved surface corresponding to the inner surface shape of the frame, and the surface of the bearing plate on the side opposite to the frame is a flat surface. By doing so, the fastening force of the bolt can be transmitted to the frame in a surface contact manner through the bearing plate, and the stability is further improved.

[0012] It is desirable to perform processing for welding removal on the end of the frame on the side opposite to the other frame.

[0013] The bolt includes a head and a shaft portion. The shaft portion preferably includes a base portion provided on the head side, a male screw portion having an outer diameter smaller than that of the base portion with a screw formed on the outer surface, and a tapered portion formed between the base portion and the male screw portion and having an inclined surface that tapers as it approaches the male screw portion.

[0014] When the bolt is used, even if there is a deviation in position (central axis) between the through-hole and the screw hole, the bolt is inserted into the hole while the shear deformation portion is sheared and deformed by the lateral force generated when the tapered portion abuts against the edge of the through-hole or the screw hole. Therefore, the clearance (margin, tolerance) between the through-hole and the bolt can be reduced, and it is difficult for a deviation to occur between the members.

Advantages of the Invention

[0015] According to the present invention successive According to the hand member, it is possible to connect steel pipes to each other simply and with high quality without forming an opening in the steel pipe.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0017] <First Embodiment> In the first embodiment, a steel pipe joint structure 1 for connecting steel pipes will be described. As shown in FIG. 1, the steel pipe joint structure 1 of the present embodiment integrally joins circular cross-section steel pipes (first steel pipe 2 and second steel pipe 3) having the same outer diameter dimension arranged vertically with each other by a joint member 4. As shown in FIG. 2(a), the joint member 4 includes a pair of frame bodies (first frame 5 and second frame 6), a connecting plate 7, and a bolt 8.

[0018] One of the frame bodies, the first frame 5, is fixed to the end of the first steel pipe 2. The first frame 5 is composed of a steel pipe having a circular cross-section. The first frame 5 of the present embodiment has the same inner diameter as the first steel pipe 2 and a wall thickness equal to or greater than that. Further, as shown in FIGS. 2(b) and 3, one end portions of a plurality of connecting plates 7 are fixed to the inner surface of the first frame 5 at intervals in the circumferential direction.

[0019] As shown in Fig. 2(a), the end of the first frame 5 on the side of the first steel pipe 2 has been processed for welding groove opening, with the outer diameter decreasing as it goes towards the first steel pipe 2 side. When the end of the first frame 5 is butted against the end of the first steel pipe 2, a groove is formed between the first frame 5 and the first steel pipe 2. When welding the first frame 5 to the first steel pipe 2, this groove is used as the welding groove opening. Optionally, a backing plate 51 may be attached to the first frame 5 or the first steel pipe 2 for welding.

[0020] The other frame body, the second frame 6, is fixed to the end of the second steel pipe 3. The second frame 6 is composed of a steel pipe with a circular cross-section. The second frame 6 of this embodiment has the same inner diameter as the second steel pipe 3 and a wall thickness equal to or greater than that. That is, the second frame 6 is made of a steel pipe with the same cross-sectional shape as the first frame 5.

[0021] The outer diameter of the end of the second frame 6 on the side of the second steel pipe 3 decreases as it goes towards the second steel pipe 3 side. When the end of the second frame 6 is butted against the end of the second steel pipe 3, a groove is formed between the second frame 6 and the second steel pipe 3. When welding the second frame 6 to the second steel pipe 3, this groove is used as the welding groove opening. Optionally, a backing plate 61 may be attached to the second frame 6 or the second steel pipe 3 for welding.

[0022] The first frame 5 and the second frame 6 (a pair of frame bodies) are connected via a connecting plate 7 with their end faces butted against each other. When the end faces of the first frame 5 and the second frame 6 are butted against each other, the other ends of the plurality of connecting plates 7 are attached to the inner surface of the second frame 6. As shown in Figs. 2(a) and 3, a plurality of through holes 62 are formed in the second frame 6 corresponding to the positions of the connecting plates 7. In this embodiment, two rows of upper and lower through holes 62, 62 are formed corresponding to each connecting plate 7. The through hole 62 has an inner diameter through which a bolt 8 can be inserted. Also, on the outer surface of the second frame 6, as shown in Fig. 2(a), a recess (counterbore) 63 is formed around the through hole 62. The recess 63 of this embodiment is circular in plan view (front view) with a diameter larger than that of the head 81 of the bolt 8. The bottom surface of the recess 63 is flat so that the lower surface (the surface on the side of the shaft portion 82) of the head 81 of the bolt 8 is in surface contact.

[0023] As shown in FIG. 2(b), bolt holes 71 are formed in the connecting plate 7 of the present embodiment corresponding to the positions of the through holes 62 of the second frame 6. The inner surface of the bolt holes 71 is subjected to female screw processing for screwing the bolts 8. As shown in FIG. 2(a), by screwing the bolts 8 passing through the through holes 62 formed in the second frame 6 into the bolt holes 71 of the connecting plate 7, the connecting plate 7 and the second frame 6 are fixed.

[0024] As shown in FIG. 4, the bolt 8 includes a head 81 and a shaft portion 82. The shaft portion 82 includes a base portion 83 provided on the head 81 side, a male screw portion 84 having an outer diameter smaller than that of the base portion 83 with a screw formed on the outer surface, a shear deformation portion 85 formed between the male screw portion 84 and the head 81, and a taper portion 86 formed between the base portion 83 and the shear deformation portion 85. The shear deformation portion 85 has an outer diameter smaller than the valley diameter of the male screw portion 84. The taper portion 86 has an inclined surface that reduces in diameter as it approaches the shear deformation portion 85. In the present embodiment, the length of the base portion 83 is equal to the value obtained by subtracting the depth of the recess 63 from the thickness of the second frame 6 (the length of the through hole 62). Also, a taper that engages with the taper portion 86 is provided at the end of the bolt hole 71 on the second frame 6 side. Note that the value obtained by adding the length of the taper portion 86 to the length of the base portion 83 may be made equal to the length of the through hole 62. In this case, the taper of the bolt hole 71 is omitted.

[0025] As shown in FIGS. 2(a) and 3, the bolt 8 connects the second frame 6 and the connecting plate 7 by passing through the through hole 62 and screwing the male screw portion 84 into the bolt hole. By doing so, the first frame 5 and the second frame 6 are connected, and as a result, the first steel pipe 2 and the second steel pipe 3 are connected via the joint member 4. A spring washer is interposed between the head 81 of the bolt 8 and the recess 63 as a locking device.

[0026] The first frame 5 and the second frame 6 are fixed to the first steel pipe 2 or the second steel pipe 3 before being transported to the site. In the present embodiment, at the manufacturing factory of the first steel pipe 2 and the second steel pipe 3, the first frame 5 and the second frame 6 are respectively fixed (welded) to the first steel pipe 2 and the second steel pipe 3.

[0027] First, temporarily fix the connecting plate 7 to the second frame 6 via the bolts 8. Next, abut the end face of the first frame 5 and the end face of the second frame 6. At this time, insert one end of the connecting plate 7 into the inner cavity of the first frame 5 and make it abut against the inner surface of the first frame 5. After abutting the end face of the first frame 5 and the end face of the second frame 6, weld one end of the connecting plate 7 to the inner surface of the first frame 5. At this time, mark the arrangement of the through hole 62 of the second frame 6 and the connecting plate 7 (bolt hole 71).

[0028] After fixing a predetermined number of connecting plates 7 to the first frame 5, remove the bolts 8 and separate the first frame 5 and the second frame 6. At the manufacturing factory of the first steel pipe 2 and the second steel pipe 3, fix (weld) the first frame 5 with the connecting plate 7 fixed thereto to the first steel pipe 2, and fix (weld) the second frame 6 to the second steel pipe 3. When connecting three or more steel pipes, fix the first frame 5 to one end of the steel pipes other than the steel pipes arranged at the upper end and the lower end, and fix the second frame 6 to the other end.

[0029] After fixing the first frame 5 and the second frame 6, carry the steel pipes (first steel pipe 2, second steel pipe 3) to the site. At the site, align the mark of the through hole 62 and the connecting plate 7, arrange the first steel pipe 2 and the second steel pipe 3 vertically, connect the first frame 5 and the second frame 6 with the bolts 8, and connect the first steel pipe 2 and the second steel pipe 3.

[0030] According to the steel pipe joint structure 1 and the joint member 4 of the present embodiment, it is not necessary to form bolt through holes in the first steel pipe 2 and the second steel pipe 3, and no cross-sectional loss occurs in the first steel pipe 2 and the second steel pipe 3. Therefore, the strength of the steel pipe does not decrease. Further, it is not necessary to insert an arm into the inner cavity side of the steel pipe during bolt joining, and it is not necessary to form an opening in the steel pipe.

[0031] In addition, since the connecting plate 7 is fixed to the first frame 5 in advance, the bolting only needs to be performed on the joint between the connecting plate 7 and the second frame 6. Therefore, the labor of on-site work can be reduced, and the construction period can be shortened.

[0032] Since the first frame 5 and the second frame 6 are fixed to the first steel pipe 2 or the second steel pipe 3 in a factory or the like, the desired quality is ensured. That is, the occurrence of distortion and error during fixation is suppressed, and high-quality fixation can be achieved. As a result, when connecting the first frame 5 and the second frame 6 on-site, the displacement of the positions of the through holes 62 and the bolt holes 71 is less likely to occur, and on-site work can be efficiently carried out. In addition, since the joint member 4 can be attached to the steel pipe with high quality, even when the clearance between the bolt 8 and the through hole 62 or the bolt hole 71 is small, construction on-site is possible.

[0033] Since the ends of each frame body (the first frame 5 and the second frame 6) on the side opposite to the other frame body are subjected to processing for welding bevels (taper processing), the frame body can be integrally fixed to the steel pipe by welding using the welding bevels.

[0034] Since the bolt 8 is provided with a tapered portion 86, even if there is a deviation in position (central axis) between the through hole 62 and the bolt hole 71, the deviation can be corrected by the tapered portion 86 abutting against and sliding along the edge of the through hole 62 or the bolt hole 71.

[0035] In addition, since the bolt 8 has a shear deformation portion 85, the bolt 8 is inserted while the shear deformation portion 85 is shearingly deformed by the lateral force generated when the tapered portion 86 abuts against the edge of the through hole 62 or the bolt hole 71. That is, even if there is a deviation in position (central axis) between the through hole 62 and the bolt hole 71, the bolt 8 enables screwing between the second frame 6 and the connecting plate 7. Also, even when the clearance (margin, tolerance) between the through hole 62 and the bolt 8 is small, the bolt 8 can be inserted. Therefore, in the manufacturing stage of the joint member 4, the clearance between the through hole 62 and the bolt 8 can be reduced, so that displacement between members is less likely to occur.

[0036] <Second Embodiment> In the second embodiment, similar to the first embodiment, a steel pipe joint structure 1 for connecting steel pipes to each other will be described. As shown in Fig. 5, the steel pipe joint structure 1 of this embodiment integrally joins circular cross-section steel pipes (first steel pipe 2 and second steel pipe 3) with the same outer diameter dimension arranged vertically by a joint member 4. As shown in Fig. 6(a), the joint member 4 includes a pair of frame bodies (first frame 5 and second frame 6), a connecting plate 7, and bolts 8.

[0037] One of the frame bodies, the first frame 5, is fixed to the end of the first steel pipe 2. The first frame 5 is composed of a steel pipe with a circular cross-section. The first frame 5 of this embodiment has the same outer diameter as the first steel pipe 2 and a wall thickness equal to or greater than that of the first steel pipe 2. Further, as shown in Figs. 6(b) and 7(a), one ends of a plurality of connecting plates 7 are fixed to the inner surface of the first frame 5 at intervals in the circumferential direction.

[0038] The first frame 5 is fixed to the first steel pipe 2 by welding in a state where the end faces of the first frame 5 and the first steel pipe 2 are butted against each other. In this embodiment, the end of the first frame 5 on the first steel pipe 2 side has a reduced outer diameter as it goes towards the first steel pipe 2 side. When the end of the first frame 5 is butted against the end of the first steel pipe 2, a groove is formed between the first frame 5 and the first steel pipe 2. When welding the first frame 5 to the first steel pipe 2, this groove is used as a groove for welding.

[0039] The other frame body, the second frame 6, is fixed to the end of the second steel pipe 3. The second frame 6 is composed of a steel pipe with a circular cross-section. The second frame 6 of this embodiment has the same outer diameter as the second steel pipe 3 and a wall thickness equal to or greater than that of the second steel pipe 3. That is, the second frame 6 is made of a steel pipe having the same cross-sectional shape as the first frame 5.

[0040] The second frame 6 is fixed to the second steel pipe 3 by welding the second frame 6 and the end faces of the second steel pipe 3 together. In the present embodiment, a machining for welding preparation is performed in which the outer diameter of the end of the second frame 6 on the second steel pipe 3 side is reduced as it goes toward the second steel pipe 3 side. When the end of the second frame 6 is abutted against the end of the second steel pipe 3, a groove is formed between the second frame 6 and the second steel pipe 3. When welding the second frame 6 to the second steel pipe 3, this groove is used as a welding start point.

[0041] As shown in FIG. 6(a), the first frame 5 and the second frame 6 (a pair of frame bodies) are connected via a connecting plate 7 with their end faces abutted against each other. When the end faces of the first frame 5 and the second frame 6 are abutted against each other, the other ends of the plurality of connecting plates 7 are attached to the inner surface of the second frame 6. As shown in FIGS. 6(a) and 7(b), a plurality of through holes 62 are formed in the second frame 6 corresponding to the positions of the connecting plates 7. In the present embodiment, two upper and lower through holes 62, 62 are formed corresponding to each connecting plate 7. The through hole 62 has an inner diameter through which a bolt 8 can be inserted. Further, a recess (counterbore) is formed on the outer surface of the second frame 6 around the through hole 62. The recess is circular in plan view (front view) with a diameter larger than that of the head 81 of the bolt 8. Further, the bottom surface of the recess is flat so that the lower surface (the surface on the shaft portion 82 side) of the head 81 of the bolt 8 is in surface contact.

[0042] In the present embodiment, as shown in FIG. 6(a), a support pressure plate is welded to the second frame 6 and integrated. Thereby, the portion where the thickness of the hole cross section is reduced due to the recess (counterbore) is reinforced. The outer surface (the surface on the second frame 6 side) of the support pressure plate 9 is a curved surface equivalent to the inner surface of the second frame 6, and the inner surface (the surface on the connecting plate 7 side) of the support pressure plate 9 is a flat surface according to the plate surface of the connecting plate 7. That is, the support pressure plate 9 is in close contact with the inner surface of the second frame 6 and the outer surface of the connecting plate 7.

[0043] As shown in Fig. 6(a), a second through-hole 72 is formed in the connecting plate 7 of the present embodiment corresponding to the position of the through-hole 62 of the second frame 6. Further, a nut 73 for screwing the bolt 8 is fixed to the inner surface of the connecting plate 7 (the surface opposite to the second frame 6) so as to communicate with the second through-hole 72. By screwing the bolt 8 passing through the through-hole 62 formed in the second frame 6 onto the nut 73, the connecting plate 7 and the second frame 6 are fixed.

[0044] As shown in Fig. 8, the bolt 8 includes a head 81 and a shaft portion 82. The shaft portion 82 includes a base portion 83 provided on the head 81 side, a male screw portion 84 having an outer diameter thinner than that of the base portion 83 with a screw formed on the outer surface, and a tapered portion 86 formed between the male screw portion 84 and the head 81. The tapered portion 86 has an inclined surface that reduces in diameter as it approaches the shear deformation portion 85. In the present embodiment, the length from the proximal end of the base portion 83 (the boundary between the head 81 and the shaft portion 82) to the distal end of the tapered portion 86 (the boundary between the tapered portion 86 and the male screw portion 84) is equal to the total value of the thicknesses of the second frame 6, the pressure plate 9, and the connecting plate 7.

[0045] As shown in Figs. 6(a) and 7(b), the bolt 8 passes through the through-hole 62 and screws the male screw portion 84 onto the nut 73 to connect the second frame 6 and the connecting plate 7. By doing so, the first frame 5 and the second frame 6 are connected, and as a result, the first steel pipe 2 and the second steel pipe 3 are connected via the joint member 4. A spring washer is interposed between the head 81 of the bolt 8 and the recess as an anti-loosening measure.

[0046] According to the steel pipe joint structure 1 and the joint member 4 of the present embodiment, even when joining steel pipes with a relatively small diameter, the same operational effects as those of the steel pipe joint structure 1 and the joint member 4 of the first embodiment can be obtained.

[0047] The embodiments of the present invention have been described above. However, the present invention is not limited to the foregoing embodiments, and each of the above-described components can be appropriately changed without departing from the spirit of the present invention. For example, in the above-described embodiment, the case of connecting steel pipes with circular cross-sections has been described. However, the cross-sectional shape of the steel pipe is not limited, and for example, it may be a square steel pipe. Also, the number of connecting plates 7 and the intervals between the connecting plates 7 may be appropriately determined. The connecting plate 7 may have a curved surface according to the shape of the first frame 5 or the second frame 6. Also, the number and arrangement of the through-holes 62 in the second frame 6 may be appropriately determined.

Explanation of Reference Numerals

[0048] 1 Steel pipe joint structure 2 First steel pipe 3 Second steel pipe 4 Joint member 5 First frame (frame body) 51 Backing plate 6 Second frame (frame body) 61 Backing plate 62 Through-hole 63 Recess 7 Connecting plate 71 Bolt hole 8 Bolt 81 Head 82 Shaft portion 83 Base portion 84 Male screw portion 85 Shearing deformation portion 86 Tapered portion 9 Support plate

Claims

1. A joint member for joining steel pipes of the same outside dimensions arranged above and below, A pair of frame bodies connected together with their end faces butted against each other; A plurality of connecting plates each having one end fixed to one of the frame bodies and the other end attached to an inner surface of the other frame body; a bolt that penetrates the other frame and is screwed into the connecting plate, A joint member, characterized in that one of the frame bodies is fixed to an end of one of the steel pipes arranged above and below, and the other of the frame bodies is fixed to an end of the other of the steel pipes arranged above and below.

2. The joint member according to claim 1 , wherein the connecting plate is formed with a bolt hole into which the bolt is screwed.

3. 2. The joint member according to claim 1, wherein a through hole through which the bolt is inserted is formed in the connecting plate, and a nut communicating with the through hole is fixed to an inner surface of the connecting plate.

4. The joint member according to any one of claims 1 to 3, characterized in that a welding groove is provided at an end of the frame body opposite to the other frame body.

5. Further comprising a bearing plate welded to the other frame body, The surface of the support plate facing the frame body is a curved surface according to the inner shape of the frame body, 5. The joint member according to claim 1, wherein a surface of the support plate opposite to the frame is flat.

6. The bolt has a head and a shaft, The shaft portion has a base portion provided on the head side, A male screw portion having an outer diameter smaller than that of the base portion and having a screw formed on an outer surface thereof; 6. The joint member according to claim 1, further comprising a tapered portion having an inclined surface formed between the base portion and the male thread portion, the inclined surface decreasing in diameter as the inclined surface approaches the male thread portion.

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