Steel pipe joint structure and plug receiver of the same, and steel pipe joint method

Abstract

To increase efficiency of a work when steel pipes are joined to each other, and improve so-called workability.SOLUTION: A steel pipe joint structure for joining one steel pipe to the other steel pipe includes: at least a pair of first plug insertion holes 11 which are provided at opposed positions in a circumferential direction of the steel pipe 10 in one steel pipe 10; at least a pair of second plug insertion holes which are provided on the other steel pipe corresponding to the first plug insertion holes 11; and a plug receiver 50 for receiving a plug inserted into the first plug insertion holes 11 and the second plug insertion holes. The plug receiver 50 has a non-circular plate-like member having a plurality of top parts 51 and side parts 52 between the top part 51 and the top part 51 whose external size is not uniform in plan view, and has a screw hole 54 on its side face.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a steel pipe joint structure, a plug holder therefor, and a steel pipe joining method. [Background technology]

[0002] As one of the mechanical joints used when joining steel pipes, a steel pipe joint has been proposed that is primarily designed to prevent a large protrusion onto the outer periphery while suppressing increases in manufacturing costs (see Patent Document 1). This steel pipe joint comprises a plurality of sheath pipe side plug insertion holes 13 provided along the circumferential direction of a sheath pipe 12, a plurality of insertion pipe side plug insertion holes 23 provided in an insertion pipe 22 and arranged to correspond to the sheath pipe side plug insertion holes 13, a plurality of plug receivers 45 provided on an inner circumferential surface 25 of the insertion pipe 22 and that receive the sheath pipe side plug insertion holes 13 and the plugs 31 inserted into the insertion pipe side plug insertion holes 23, and the plugs 31 are fastened to the plug receivers 45 by threading bolts 7 inserted into the bolt insertion holes of the plugs 31 into the threaded holes of the plug receivers 45 and tightening them. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-3206 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when considering the actual situation of joining steel pipes using the above-described steel pipe joint, the structure of the steel pipe joint makes it difficult to improve the efficiency of the work, resulting in work that is poor in terms of workability.

[0005] Therefore, an object of the present invention is to provide a steel pipe joint structure, a plug holder therefor, and a steel pipe joining method that can improve the efficiency of work when joining steel pipes and thereby enhance workability. [Means for solving the problem]

[0006] One aspect of the present invention is a steel pipe joint structure for joining one steel pipe to another steel pipe, At least a pair of first plug insertion holes provided in one steel pipe at positions facing each other along the circumferential direction of the steel pipe; at least a pair of second plug insertion holes provided in another steel pipe corresponding to the first plug insertion holes; a plug receptacle for receiving a plug inserted into the first plug insertion hole and the second plug insertion hole; Including, The plug receptacle is a steel pipe joint structure in which the outer dimensions are not constant when viewed in a plane, and it is a non-circular plate-like member having multiple tops and sides between the tops, and has a screw hole on the side.

[0007] In conventional steel pipe joint structures, each plug must be received in a separate plug receptacle, which requires a lot of work. The steel pipe joint structure of one aspect of the present invention, which was developed by addressing this problem, makes it possible to receive multiple plugs collectively using only one plug receptacle with a threaded hole on the side. Furthermore, this plug receptacle is sized and structured so that it can be inserted into a steel pipe with its plate surface held approximately vertical and then rotated a predetermined amount in that state to engage its top with a first plug insertion hole or the like. Furthermore, it can be tilted in that state so that the plate surface faces up and down to be positioned in a predetermined position. This makes it possible to improve work efficiency and ease of installation compared to using individual plug receptacles one by one.

[0008] In the steel pipe joint structure as described above, the plug receiver may have a polygonal shape in plan view.

[0009] In the steel pipe joint structure as described above, the plug receiver may have a hexagonal shape in plan view.

[0010] In the steel pipe joint structure described above, the plug receiver may be annular.

[0011] In the steel pipe joint structure as described above, the plug may be provided with a bolt insertion hole through which a fixing bolt is inserted.

[0012] In the steel pipe joint structure described above, the threaded hole of the plug receiver may be provided so as to be threadedly engaged with a bolt.

[0013] 7. A steel pipe joint structure as set forth in any one of claims 1 to 6, wherein an engaging portion is formed on the inner peripheral surface of one of the steel pipes to engage with the top of the plug holder and restrict downward movement of the plug holder in the engaged state.

[0014] In the steel pipe joint structure as described above, the locking portion may be formed by a step where the inner diameter changes on the inner peripheral surface of one of the steel pipes.

[0015] In the steel pipe joint structure as described above, the step forming the locking portion may extend around the inner peripheral surface of one of the steel pipes.

[0016] In the steel pipe joint structure as described above, the step may be a part of an annular groove formed on the inner peripheral surface of one of the steel pipes.

[0017] In the steel pipe joint structure as described above, the locking portion may be formed to match the position of the end of the first plug insertion hole.

[0018] Another aspect of the present invention is a plug receiver constituting a steel pipe joint structure for joining one steel pipe having at least a pair of first plug insertion holes provided at positions opposite to each other in the circumferential direction, and another steel pipe having at least a pair of second plug insertion holes provided corresponding to the first plug insertion holes, The plug receptacle is a non-circular plate-like member that does not have uniform outer dimensions when viewed in a plane, has multiple vertices and sides between the vertices, and has a structure with screw holes on the side surfaces.

[0019] Yet another aspect of the present invention is a steel pipe joining method for joining one steel pipe to another steel pipe using the steel pipe joint structure as described above, a step of inserting the plug receiver into one steel pipe with its plate surface approximately vertical; a step of rotating the plug receiver out of and within the plane of its plate surface to lock the top of the plug receiver onto the locking portion; a step of fastening the plug to the plug receiver by inserting a plug into the first plug insertion hole and the second plug insertion hole and threading a bolt inserted into a bolt insertion hole of the plug into a threaded hole of the plug receiver and tightening the bolt; A steel pipe joining method comprising:

[0020] The above steel pipe joining method is as follows: a step of fitting one steel pipe to another steel pipe; a step of aligning at least a pair of first plug insertion holes provided in one steel pipe at positions facing each other along the circumferential direction of the steel pipe with at least a pair of second plug insertion holes provided in another steel pipe corresponding to the first plug insertion holes; The method may further include the step of inserting plugs into the aligned second plug insertion holes and the first plug insertion holes. [Effects of the Invention]

[0021] According to the present invention, it is possible to provide a steel pipe joint structure, a plug holder therefor, and a steel pipe joining method that make it possible to improve the efficiency of work when joining steel pipes and thereby improve so-called workability. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a longitudinal cross-sectional view showing an example of a steel pipe. [Figure 2] FIG. 2 is a plan view showing an example of a bolt fixing ring (plug receiver) according to an embodiment of the present invention. [Figure 3] 1A and 1B are a plan view and a longitudinal cross-sectional view, respectively, seen from the side, showing how a bolt-fastening ring (plug receiver) is inserted into a steel pipe with its plate surface held substantially vertical. [Figure 4]FIG. 1A is a plan view showing a bolt-fastening ring (plug receptacle) being inserted into a steel pipe with its plate surface approximately vertical and the part with the smallest outer dimension facing horizontally, and FIG. 1B is a longitudinal cross-sectional view seen from the side. [Figure 5a] FIG. 1A is a plan view and FIG. 1B is a longitudinal cross-sectional view seen from the side, showing how a bolt-stop ring (plug receptacle) inserted into a steel pipe is rotated out of and within the plane of its plate surface to lock the top of the bolt-stop ring (plug receptacle) into the locking portion. [Figure 5b] (A) A longitudinal cross-sectional view taken along a horizontal axis (the axis around which the bolt locking ring rotates) showing, in chronological order (A) and (B), the state in which a bolt locking ring (plug receptacle) inserted into a steel pipe is rotated out of and within the plane of its plate surface until the top of the bolt locking ring (plug receptacle) is locked onto the locking portion. [Figure 6] 1A and 1B are a plan view and a longitudinal cross-sectional view, respectively, showing the state when the bolt fixing ring (plug receiver) is turned over so that the plate surface faces up and down. [Figure 7] 1A and 1B are a plan view and a longitudinal cross-sectional view, respectively, of a bolt-fastening ring (plug receiver) when the ring is turned over so that the plate faces up and down. [Figure 8] FIG. 10 is a plan view showing the state when the bolt fixing ring (plug receiver) is turned over so that the plate surface faces up and down and rotated around a vertical axis. [Figure 9] FIG. 2 is a diagram illustrating the relationship between the inner diameter of one steel pipe and the outer dimensions of a bolt fixing ring (plug receiver). DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, a steel pipe joint structure, its plug receptacle, and a steel pipe joining method according to the present invention will be described in detail based on an example of an embodiment shown in the drawings (see Figs. 1 to 9).

[0024] The steel pipe joint structure 1 is provided as a structure for joining one steel pipe 10 to another steel pipe 20 (see Fig. 1). The steel pipe joint structure 1 of this embodiment is provided to include a first plug insertion hole 11, a second plug insertion hole 21, a plug 30, a bolt 40, and a plug receptacle (hereinafter also referred to as a bolt locking ring) 50 (see Fig. 3, etc.). For convenience, in the following description, the central axis of the one steel pipe 10 will be referred to as the vertical axis, and the axis perpendicular to the vertical axis will be referred to as the horizontal axis, and these will be represented by the symbols 10A and 10B in the drawings, respectively.

[0025] A first steel pipe 10 and another steel pipe 20 are joined by a steel pipe joint structure 1 to form a steel pipe pile, such as a flanged pile, that is driven into the ground. In this embodiment, the steel pipe joint structure 1 is used to join another steel pipe 20 to the upper part of the first steel pipe 10 that has been driven into the ground (see FIG. 1 ). A flange portion 10f is provided on the outer periphery of the upper part of the first steel pipe 10, against which the lower end of the other steel pipe 20 abuts (see FIG. 1 , etc.). Furthermore, a plurality of first plug insertion holes 11 are provided along the circumferential direction in the upper part of the first steel pipe 10, and a plurality of second plug insertion holes 21 are provided along the circumferential direction in the lower part of the other steel pipe 20. These first plug insertion holes 11 and second plug insertion holes 21 are arranged so that they all overlap midway when the other steel pipe 20 is rotated relative to the first steel pipe 10. By inserting plugs 30 into the overlapping first plug insertion holes 11 and second plug insertion holes 21 from the outer periphery of the other steel pipe 20, the other steel pipe 20 becomes locked with respect to the one steel pipe 10. In this embodiment, the first plug insertion holes 11 of the one steel pipe 10 and the second plug insertion holes 21 of the other steel pipe 20 are each composed of three pairs of holes provided at opposing positions along the circumferential direction, for a total of six holes, but this is merely a suitable example, and it is sufficient if at least one pair (two holes in total) is provided.

[0026] An annular groove 14 is formed around the inner peripheral surface 12 of the first steel pipe 10 (see FIG. 4(B), FIG. 9, etc.). The inner diameter of the inner peripheral surface 12 of the first steel pipe 10 (where the annular groove 14 is not provided) is D1, and the inner diameter of the portion where the annular groove 14 is provided is D2 (D2 > D1). The lower portion of the annular groove 14 has a step 16 whose radial difference is (D2 - D1) / 2. In the steel pipe joint structure 1 of this embodiment, this step 16 forms a locking portion 15 that locks only the apex 51 constituting the apex of the bolt locking ring 50 (described later) and restricts downward movement of the bolt locking ring 50 in the locked state. In this embodiment, the locking portion 15 configured in this manner is formed to match the position of the lower end 11b of the first plug insertion hole 11 (see FIGS. 1, 4, etc.).

[0027] The plug 30 is a component that is inserted into the overlapping first plug insertion hole 11 and second plug insertion hole 21 to lock one steel pipe 20 against the other steel pipe 10. Although not shown in particular detail, the plug 30 of this embodiment is substantially cylindrical, and has a bolt insertion hole 34 at its center through which the threaded portion 44 of the bolt 40 is inserted (see FIG. 1). The end of the plug 30 may be provided with a concave seat into which the head 42 of the bolt 40 is housed.

[0028] The bolt 40 is used to fasten the plug 30 inserted into the first plug insertion hole 11 and the second plug insertion hole 21 to the bolt locking ring 50. The threaded portion 44 of the bolt 40 inserted into the bolt insertion hole 34 of the plug 30 has its tip portion threadably engaged with the threaded hole 54 of the bolt locking ring 50 (see FIGS. 1 and 2).

[0029] The bolt locking ring 50 is a single member configured to receive the plugs 30 inserted into the first plug insertion hole 11 and the second plug insertion hole 21, and to fix the plugs 30 by screwing in the bolts 40. In conventional steel pipe joint structures, each plug was received in a separate plug receiving member, which required a lot of work, but in this embodiment, it is possible to receive multiple plugs 30 collectively by using just one bolt locking ring 50 having threaded holes 54 on the side surface.

[0030] The bolting ring 50 of this embodiment has a noncircular polygonal shape, such as a circular hexagonal shape, with variable outer dimensions in plan view. It is formed from a plate-like member having a plurality of, for example, three pairs of opposing apexes 51 (total of six), and six sides 52 between adjacent apexes 51 (total of six sides 52) (see FIG. 2, etc.). In plan view showing the upper (or lower) plate surface 56 of the bolting ring 50, the maximum outer dimension (maximum width) Y is the distance between the opposing apexes 51, and the minimum outer dimension (minimum width) X is the distance between the opposing sides 52 (see FIG. 2). The maximum outer dimension Y is greater than the inner diameter D1 of the inner circumferential surface 12 of one steel pipe 10 and less than the inner diameter D2 of the portion where the annular groove 14 is provided (D2>Y>D1). Furthermore, the minimum outer dimension X is less than the inner diameter D1 of the inner circumferential surface 12 of one steel pipe 10 (D2>Y>D1>X). Furthermore, a screw hole 54 is provided at the approximate center of each side portion 52 so that the threaded portion 44 of the bolt 40 can be threadedly engaged therewith (see FIG. 2, etc.). As shown in the figure, the ring 50 of this embodiment is symmetrical about a center line (here, the center line includes both the line connecting the opposing top portions 51 and the line connecting the opposing side portions 52), and has a shape in which the weight is balanced on both sides of the center line. A bolt-fastening ring 50 with such a shape can be easily inserted into a steel pipe 10, rotated, tilted, and so on, as will be described later.

[0031] An example of a procedure for joining one steel pipe 10 to another steel pipe 20 using the above-described steel pipe joint structure 1 will be described (see Figures 3 to 8, etc.). For ease of explanation, the axis that is perpendicular to the plate surface 56 of the bolted ring 50 and passes through the center of the annular bolted ring 50 will be defined as the "center axis 50c" (see Figures 4, 5a, 5b, etc.).

[0032] First, the bolt-fastening ring 50 is inserted into the upper opening of one steel pipe 10 that has been driven into the ground along the vertical axis 10A with its side portions 52 positioned on the left and right and its width being the minimum outer dimension X, and with its plate surface 56 in a substantially vertical position (see Figures 3 and 4).

[0033] When the center of the bolting ring 50 is at a height approximately equal to the annular groove 14 of one steel pipe 10, the bolting ring 50 is rotated appropriately out of the plane of the plate surface 56 around the vertical axis 10A (out-of-plane rotation here refers to rotation that does not fit within a plane including the plate surface 56) so that a pair of first plug insertion holes 11 are positioned on both sides of the edge 52 of the bolting ring 50 (see FIG. 5a). Next, the bolting ring 50 is rotated within the plane of the plate surface 56. The in-plane rotation here refers to rotation within a plane including the plate surface 56, or in other words, rotation (or pivoting) around the central axis 50c (see FIG. 5a). In this embodiment, the bolting ring 50 is rotated approximately 30° around the central axis 50c, which is horizontal (in other words, horizontal with the horizontal axis 10B), so that at least a portion of the left and right peaks 51 are within the area of ​​the annular groove 14. At this time, the left-right width of the bolt fixing ring 50 becomes the maximum outer dimension Y, and the tops 51 located on the left and right are respectively capable of being locked onto the steps 16.

[0034] Next, with the left and right apexes 51 still engaged with the steps 16, the bolting ring 50 is tilted to a horizontal position (see FIGS. 5B, 6, and 7). In light of the above explanation, this constitutes an out-of-plane rotation. When the bolting ring 50 is tilted to a horizontal position, all (six in this embodiment) of the apexes 51 are engaged with the steps 16 of one steel pipe 10, preventing the bolting ring 50 from moving downward (falling) (see FIG. 7). Then, the bolting ring 50 is rotated within the plane of the plate surface 56, i.e., rotated (or pivoted) by approximately 30° around the now-vertical central axis 50c, and the positions of the screw holes 54 are aligned so that they are linearly connected to the first plug insertion holes 11 of one steel pipe 10 (see FIG. 8). As described above, in this embodiment, the step 16 or locking portion 15 is formed to match the position of the lower end portion 11b of the first plug insertion hole 11, so that the height of the screw hole 54 of the bolt fixing ring 50 when locked to the step 16 matches the height of the first plug insertion hole 11 (see Figure 7).

[0035] After completing the steps up to this point, another steel pipe 20 is fitted onto the top of the first steel pipe 10, and the other steel pipe 20 is rotated appropriately around the vertical axis to align the first plug insertion holes 11 with the second plug insertion holes 21. In the case of this embodiment, this brings into communication three pairs of first plug insertion holes 11 (six in total) provided at positions facing each other along the circumferential direction of the first steel pipe 10 with three pairs of second plug insertion holes 21 (six in total) provided in the other steel pipe 20 corresponding to the first plug insertion holes 11. Then, plugs 30 are inserted into the second plug insertion holes 21 and first plug insertion holes 11 from the outside of the other steel pipe 20 and pushed in until they abut against the bolt locking ring 50. After the plug 30 is inserted, the bolt 40 is inserted into the bolt insertion hole 34 of the plug 30, and the tip of the threaded portion 44 of the bolt 40 is screwed into the threaded hole 54 of the bolt fixing ring 50 and tightened (see Figures 1 and 2). By tightening all of the plugs (six in this embodiment) 30 to the bolt fixing ring 50 in the same procedure, the operation of joining one steel pipe 10 to another steel pipe 20 is completed.

[0036] According to the above-described bolt locking ring (plug receiver) 50 and the steel pipe joint structure 1 including it, the bolt locking ring 50 can be inserted into one steel pipe 10 with its plate surface 56 held approximately vertical (see Figure 4), and then rotated a predetermined amount in that state (out-of-plane rotation, in-plane rotation) to lock the top 51 into the first plug insertion hole 11 or the like (specifically, the locking portion 15 formed by the step 16 of the annular groove portion 14 in this embodiment) (see Figure 5a), and furthermore, the structure allows the bolt locking ring 50 to be positioned in a predetermined position by tilting it so that the plate surface 56 faces up or down in that state, making it possible to make work more efficient and improve what is called workability compared to using individual bolt locking rings 50 one by one.

[0037] The above-described embodiment is one example of a preferred embodiment of the present invention, but is not limited to this and various modifications are possible within the scope of the present invention. For example, in the above-described embodiment, the locking portion 15 is described as being formed by a flat step 16 in the annular groove portion 14, but this is merely one preferred example. Although not specifically shown, the locking portion 15 may also be formed by a step 16 in which the inner diameter changes continuously, such as a tapered surface, or a step 16 in which the inner diameter changes intermittently.

[0038] Furthermore, in the above-described embodiment, a structure was shown in which the step 16 constituting the locking portion 15 surrounds the inner surface 12 of one steel pipe 10, but this is also only one suitable example, and although not specifically shown, the locking portion 15 may also be constituted by a step 16 formed partially or intermittently along the circumferential direction of the inner surface 12.

[0039] In the above embodiment, the annular bolting ring 50 is shown, but this is merely one suitable example. The bolting ring 50 does not have to have a bilaterally symmetrical structure, and may have a C-ring shape with a broken portion in the middle. [Industrial Applicability]

[0040] The present invention is suitable for application to a steel pipe joint structure, a plug holder therefor, and a steel pipe joining method. [Explanation of symbols]

[0041] 1...Steel pipe joint structure 10...One steel pipe 10A...Vertical axis 10B…Horizontal axis 10f...flange 11...First plug insertion hole 11b...Lower end of first plug insertion hole 12...Inner peripheral surface 14...Annular groove 15...Latching part 16...Step 20...Other steel pipes 21...Second plug insertion hole 30...Plug 34...Bolt insertion hole 40...volts 42...Head 44...Threaded section 50...Bolt fixing ring (plug holder) 50c…Central axis 51...Top 52...Edge 54...Screw hole 56...Plate surface D1: Inner diameter of the inner circumferential surface 12 of one steel pipe 10 D2: Inner diameter of the portion where the annular groove portion 14 is provided X: Minimum outer dimension Y: Maximum outer dimension

Claims

1. A steel pipe joint structure for joining one steel pipe to another steel pipe, at least a pair of first plug insertion holes provided in the one steel pipe at positions opposing each other along the circumferential direction of the steel pipe; at least one pair of second plug insertion holes provided in the other steel pipe corresponding to the first plug insertion holes; a plug receiver for receiving plugs inserted into the first plug insertion hole and the second plug insertion hole; Including, The plug receptacle is a non-circular plate-like member having a plurality of apexes and sides between the apexes, and does not have a constant outer dimension when viewed in a plane, and has a screw hole on the side.

2. The steel pipe joint structure according to claim 1, wherein the plug receiver has a polygonal shape in a plan view.

3. The steel pipe joint structure according to claim 2, wherein the plug receiver has a hexagonal shape in a plan view.

4. The steel pipe joint structure according to claim 3, wherein the plug receiver is annular.

5. 2. The steel pipe joint structure according to claim 1, wherein the plug is provided with a bolt insertion hole through which a fixing bolt is inserted.

6. The steel pipe joint structure according to claim 5, wherein the threaded hole of the plug receiver is provided so as to be threadably engaged with the bolt.

7. 7. The steel pipe joint structure according to claim 1, wherein an engaging portion is formed on an inner peripheral surface of the one steel pipe to engage with the top of the plug receiver and to restrict downward movement of the plug receiver in the engaged state.

8. The steel pipe joint structure according to claim 7, wherein the locking portion is formed by a step where the inner diameter changes on the inner peripheral surface of the first steel pipe.

9. 9. The steel pipe joint structure according to claim 8, wherein the step forming the locking portion extends around the inner peripheral surface of the first steel pipe.

10. The steel pipe joint structure according to claim 9, wherein the step is a part of an annular groove formed on the inner peripheral surface of the first steel pipe.

11. The steel pipe joint structure according to claim 9, wherein the locking portion is formed to align with the position of an end of the first plug insertion hole.

12. A plug receiver constituting a steel pipe joint structure for joining one steel pipe having at least a pair of first plug insertion holes provided at positions opposite to each other in the circumferential direction, and another steel pipe having at least a pair of second plug insertion holes provided corresponding to the first plug insertion holes, A plug receiver that is a non-circular plate-like member whose outer dimensions are not constant when viewed in a plane, has multiple vertices and sides between the vertices, and has a structure with screw holes on the sides.

13. A steel pipe joining method for joining one steel pipe to another steel pipe using the steel pipe joint structure according to any one of claims 7 to 11, a step of inserting the plug receiver into the first steel pipe with its plate surface approximately vertical; a step of rotating the plug receiver out of and within the plane of its plate surface to engage the top of the plug receiver with the engaging portion; a step of fastening the plug to the plug receiver by inserting a plug into the first plug insertion hole and the second plug insertion hole and threading a bolt inserted into a bolt insertion hole of the plug into a threaded hole of the plug receiver and tightening the bolt; A steel pipe joining method comprising:

14. a step of fitting another steel pipe onto the one steel pipe; a step of aligning at least a pair of first plug insertion holes provided in the one steel pipe at positions opposing each other in the circumferential direction of the steel pipe with at least a pair of second plug insertion holes provided in the other steel pipe corresponding to the first plug insertion holes; The steel pipe joining method according to claim 13, further comprising the step of inserting plugs into the aligned second plug insertion holes and the aligned first plug insertion holes.

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