Steel pipe Hangzhou joint structure

Abstract

To provide a joint structure for steel pipe piles that facilitates connection work.SOLUTION: A joint structure includes a first joint connected to an end of a first steel pipe pile, a second joint connected to an end of a second steel pipe pile, and a pin, and is configured to connect the first joint and the second joint by the pin. The first joint and the second joint are provided with a pin hole penetrating both when they are fitted together. The pin comprises: a pin body inserted into the pin hole; a flexible portion provided at a tip of the pin body, having a larger diameter than that of the pin hole in an unloaded state, engaged with a peripheral edge of an inner peripheral side opening of the pin hole, and reduced in diameter when the pin body is inserted into the pin hole; and a projection formed on the other end of the pin body and engaged with a periphery of an outer peripheral side opening of the pin hole.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an improvement in the joint structure of a steel pipe pile. [Background technology]

[0002] Steel pipe piles for construction and civil engineering works are extended depending on the condition of the ground and driven to the desired depth. Various methods have been proposed for connecting steel pipe piles, one of which is a structure in which a joint is connected to the upper end of the lower steel pipe pile and the lower end of the upper steel pipe pile, and the two are connected with a pin (Patent Document 1, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-161662 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-031717 Summary of the Invention [Problem to be solved by the invention]

[0004] The pin used in the joint structure disclosed in Patent Document 1 has a bolt structure, and the joints of the upper and lower steel pipe piles are connected by screwing this bolt into a fixing plate welded to the inner surface of the fitted joint (Figure 1, citing Figure 2 of Patent Document 1). When a bolt is used as a pin in this way, sufficient torque is required at the threaded portion of the bolt, which requires a thick bolt shaft, which increases costs and makes the tightening process time-consuming. In the joint structure of Patent Document 2, a thin bolt is passed through the pin (Figure 2, quoting Figure 1 of Patent Document 2), which requires two steps: driving in the pin and then driving in the bolt, making the connection work time-consuming. [Means for solving the problem]

[0005] The present invention has been made to solve such problems, and its first aspect is defined as follows: A joint structure for a steel pipe pile comprising a first joint connected to an end of a first steel pipe pile, a second joint connected to an end of a second steel pipe pile, and a pin, and connecting the first joint and the second joint with the pin, The first and second joints are provided with pin holes that pass through them when they are fitted together, The pin a pin body to be inserted into the pin hole; a flexible portion provided at the tip of the pin body, the flexible portion having a diameter larger than that of the pin hole in an unloaded state, engaging with the periphery of the inner peripheral opening of the pin hole, and contracting in diameter when the pin body is inserted into the pin hole; a protrusion formed on the other end of the pin body, the protrusion engaging with the periphery of the outer peripheral opening of the pin hole; A joint structure for a steel pipe pile comprising:

[0006] According to the joint structure of the first aspect defined above, the flexible portion provided at the tip of the pin body engages with the periphery of the inner opening of the pin hole, and the protrusion provided at the other end of the pin body engages with the periphery of the outer opening of the pin hole, thereby connecting the fitted first and second joints. Here, by providing the flexible portion with an elastic repulsive force, the connection between the two is made even stronger. When the pin body is inserted into the pin hole, the flexible portion contracts in diameter and does not interfere with the insertion process. In other words, the pin can be inserted into the pin hole from the outer periphery of the joint fitting between the first and second joints by simply striking the other end of the pin body with a hammer or the like while the tip of the pin body is facing the pin hole. This simplifies the process of connecting joint fittings using a pin. A protrusion on the other end of the pin body engages with the periphery of the outer opening of the pin hole, preventing the pin body from being struck too hard and falling out toward the inner periphery of the joint fitting. Furthermore, the protrusion engages with the periphery of the outer opening, fixing the position of the other end of the pin body, thereby fixing the position of the flexible portion, thereby stabilizing the engagement of the flexible portion with the periphery of the inner opening of the pin hole.

[0007] The second aspect of the present invention is defined as follows: In the joint structure defined in the first aspect, the distance from the protrusion to the tip of the pin body is longer than the pin hole, and the tip of the pin body protrudes from the pin hole when the pin body is inserted into the pin hole, The flexible portion is made of flexible steel and includes a fixed portion fixed to the tip portion, and a flexible portion main body connected to the fixed portion, the flexible portion main body having an engaging portion that protrudes outward from the tip portion toward the outer periphery and engages with the periphery of the inner opening of the pin hole.

[0008] According to the joint structure of the second aspect defined above, by projecting the tip of the pin body from the inner circumferential opening of the pin hole, the engaging portion of the flexible portion attached to the tip is released from the pin hole, thereby reliably engaging the engaging portion with the periphery of the inner circumferential opening. On the other hand, if the tip of the pin body does not protrude from the pin hole, the engagement between the engaging portion of the flexible portion body and the inner opening of the pin hole becomes unstable because there is a risk that the engaging portion will not come out completely from the pin hole.

[0009] The third aspect of the present invention is defined as follows: In the joint structure defined in the second aspect, a recess is provided on the periphery of the tip of the pin body, and the engaging portion of the flexible portion body engages with the periphery of the inner opening of the pin hole when stored in the recess. According to the joint structure defined in this way, the engaging portion of the flexible portion main body is housed in a recess formed on the periphery of the tip of the pin main body and engages with the periphery of the inner opening of the pin hole.

[0010] Since the tip of the pin body protrudes from the inner peripheral surface of the joint fitting, in order for the engaging part of the flexible part attached to the tip to engage with the periphery of the opening on the inner peripheral side of the pin hole, a barb (a part extending from the tip of the pin body toward its base) is required on the engaging part of the flexible part according to the length of the protrusion. This barb part provides resistance when the pin is inserted. Here, by providing a recess at the tip and accommodating the engaging portion in this recess, resistance when inserting the pin can be reduced. Furthermore, by providing a recess and accommodating the engaging portion, the position of the engaging portion can be brought closer to the periphery of the inner opening of the pin hole. In other words, the distance between the engaging portion and the side of the pin body can be reduced. This reduces the amount of diameter contraction of the flexible portion when inserting the pin, which also reduces resistance when inserting the pin.

[0011] A fourth aspect of the present invention is defined as follows: In the joint structure defined in the third aspect, the recess has an axial depth of the pin body that reaches the pin hole when the pin body is inserted into the pin hole, and its radial depth accommodates the outermost part of the engaging portion that faces the recess when the pin body passes through the pin hole. According to the coupling structure of the fourth aspect defined above, the recess is designed to reach the pin hole in the axial direction of the pin body, so that the engaging portion can reliably engage near the periphery of the inner opening of the pin hole. The recess is designed to be deep enough in the radial direction of the tip end so that the engaging portion is entirely housed within the recess when the pin body passes through the pin hole. This further reduces resistance when driving the pin into the pin hole.

[0012] The fifth aspect of the present invention is defined as follows: In the joint structure of the fourth aspect, the flexible portion is an M-shaped linear or thin plate-like member, and while it stands up from the tip of the pin body, the central part of the M-shape is fixed to the center of the tip, and in an unloaded state, both ends of the M-shape are stored in the recess as the engaging portion, while the lower end thereof protrudes outward from the recess and engages with the periphery of the inner opening of the pin hole. According to the joint structure of the fifth aspect defined in this way, the structure of the flexible portion can be simplified. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view showing a conventional joint structure. [Figure 2]FIG. 2 is an exploded perspective view showing another conventional joint structure. [Figure 3] FIG. 3 is a cross-sectional view showing a connection structure of a steel pipe pile according to one embodiment of the present invention. [Figure 4] FIG. 4 shows the pin of the embodiment, with FIG. 4(A) being a front view, (B) being a right side view, (C) being a left side view, and (D) being a bottom view. [Figure 5] FIG. 5 is a partial enlarged view showing the structure of the recess. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Figure 3 is a cross-sectional view showing a joint structure 1 of one embodiment of the present invention. In the figure, reference numerals 3 and 5 denote steel pipe piles. A first joint 10 is welded to the upper first steel pipe pile 3, and a second joint 20 is welded to the lower second steel pipe pile 5. In this example, the first steel pipe pile 3 and the second steel pipe pile 5 have the same diameter, but they can also have different diameters.

[0015] The first joint 10 comprises a joint base 11, an outer ring 13, and an inner ring 15. The joint base 11 is thicker than the first joint 10, the outer ring 13, and the inner ring 15, and the lower end of the first steel pipe pile 3 is welded to the center of its upper surface through an opening. The outer ring 13 is welded to the outer edge of its lower surface, and the inner ring 15 is welded to the inner edge of its lower surface through an opening, respectively. A pin hole 17 is drilled in the outer ring 13, and a pin hole 18 is drilled in the inner ring 15.

[0016] The lower edge of the second joint 20 is welded to the upper end of the second steel pipe pile 5 through the opening. A pin hole 21 is drilled in the second joint 20. It is also possible to drill a pin hole 21 directly into the upper end portion of the second steel pipe pile 5 and insert this into the first joint 10. In this case, the upper end portion of the second steel pipe pile 5 becomes the second joint. In other words, there are cases where the second joint is integrally connected to the second steel pipe pile. By inserting the second joint 20 between the outer ring portion 13 and the inner ring portion 15 of the first joint 10, a joint fitting body is formed between the first joint 10 and the second joint 20, and at this time the three pin holes 17, 21, and 18 are connected.

[0017] A pin 30 is inserted into the pin holes 17, 21, and 18. The pin 30 comprises a pin body 31 , a flexible portion 40 and a protrusion 50 . The pin body 31 is a cylindrical member having a diameter slightly smaller than the diameter of the pin hole, and has a flexible portion 40 at its tip end 33 and a protrusion 50 on the periphery of the other end 35. As shown in Figure 4, the flexible portion 40 consists of a wire of spring steel bent into an M shape, and the lower edge of the central part of the M (fixed part 41) is welded to the central part of the tip portion 33 of the pin body 31.

[0018] A pair of flexible portion bodies 43 rise from the fixed portion 41 toward the axial tip side of the pin body 31 and are bent outward. The tip (engagement portion 45) of each flexible portion body 43 protrudes outward from the tip portion 33 of the pin body 31. In other words, in an unloaded state, the flexible portion 40 has a larger diameter than the tip portion 33. A recess 37 is provided on the periphery of the tip portion 33 at a position facing the engaging portion 45. In an unloaded state, a portion of the inner peripheral side of the engaging portion 45 is housed in this recess 37. The lower end of the engaging portion 45 protrudes outward from the recess 37 toward the outer periphery, thereby engaging with the periphery of the opening on the inner peripheral side of the pin hole 18 (see FIG. 5). The lower end of the engaging portion 45 is also housed in the recess 37, and is therefore located closer to the base of the pin body 31 (towards the other end 35) than the tip portion 33.

[0019] The recess 37 has a depth U1 in the axial direction of the pin body 31. This depth U1 is greater than the length (protrusion amount L) by which the pin body 31 protrudes from the pin hole 18. By storing the portion of the flexible portion body 43 continuing to the engaging portion 45 in this recess 37, the position of the engaging portion 45 can be brought as close as possible to the periphery of the opening of the pin hole 18. The recess 37 has a depth U2 in the radial direction of the tip 33 of the pin body 31. This depth U2 is set so that when the pin 30 is driven into the pin hole, the outer periphery (outermost part) of the engagement portion 45 is housed in the recess 37. This reduces the resistance to driving the pin 30 into the pin hole.

[0020] A pair of protrusions 37 are formed on the periphery of the other end 35 of the pin body 31. By making the distance between these protrusions 37 and the engaging portion 45 the same as the thickness of the first joint 10, the pin 30 can firmly connect the joint fitting body of the first joint 10 and the second joint 20 without any rattle. In this example, as shown in FIG. 4(C), the protrusion 50 is provided at a position displaced by 90 degrees from the recess 37 in a side view, but the position and number of the protrusions are not particularly limited.

[0021] The construction method for this joint structure is as follows. It is assumed that a first joint 10 is welded to the lower end of the first steel pipe pile 3 in advance, and a second joint 20 is welded to the upper end of the second steel pipe pile 5 in advance. After the second steel pipe pile 5 is embedded in the ground, the first joint 10 of the first steel pipe pile 3 is fitted into its second joint 20. The pin holes 17, 21, 18 of each joint are passed through, and pins 30 are driven in from the outer periphery.

[0022] Because the flexible portion 40 fixed to the tip 33 of the pin body 31 is M-shaped, it can be inserted into the pin hole 17 from the tip side without resistance. After being inserted into the pin hole 17, it interferes with the periphery of the pin hole 17 and reduces in diameter, and the engaging portion 45 is housed in the recess 37, so there is no resistance when driving the pin 30. With the tip 33 of the pin body 31 protruding from the pin hole 18, the engaging portion 45 is released from interference with the peripheral surface of the pin hole 18, expands in diameter, and engages with the periphery of the opening of the pin hole 18.

[0023] In the above description, an M-shaped flexible section has been taken as an example, but the present invention is not limited to this. Any design can be used as long as it is made of flexible steel, a portion of which is fixed to the tip of the pin body, a portion of which protrudes outward from the tip of the pin body to engage with the inner peripheral opening edge of the pin hole of the joint, and can reduce in diameter when the pin is inserted to reduce insertion resistance.

[0024] The structure of the joints is not limited to the example shown in Fig. 3. For example, a ring-shaped joint may be welded to each of the first steel pipe pile and the second steel pipe pile, and the two may be fitted together. As described above, the present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the claims and within the scope that can be easily conceived by a person skilled in the art. [Explanation of symbols]

[0025] 1 Joint structure 3 First steel pipe pile 5 Second steel pipe pile 10 1st joint 20 Second joint 17, 18, 21 pin holes 30-pin 31-pin body 33 Tip 35 Other end 37 Recess 40 Flexible part 41 Fixed part 43 Flexible part main body 45 Engagement part 50 protrusions

Claims

1. A joint structure for a steel pipe pile comprising a first joint connected to an end of a first steel pipe pile, a second joint connected to an end of a second steel pipe pile, and a pin, and connecting the first joint and the second joint with the pin, The first and second joints are provided with pin holes that pass through them when they are fitted together, The pin a pin body to be inserted into the pin hole; a flexible portion provided at the tip of the pin body, the flexible portion having a diameter larger than that of the pin hole in an unloaded state, engaging with the periphery of the inner peripheral opening of the pin hole, and contracting in diameter when the pin body is inserted into the pin hole; a protrusion provided on the other end of the pin body, the protrusion engaging with a peripheral edge of an outer peripheral opening of the pin hole; A joint structure for a steel pipe pile comprising: a distance from the projection to the tip of the pin body is longer than the pin hole, and when the pin body is inserted into the pin hole, the tip of the pin protrudes from the pin hole; The flexible portion is made of a flexible steel material, and the coupling structure includes a fixed portion fixed to the tip portion, and a flexible portion main body that bulges outward from the fixed portion and includes an engaging portion that engages with the periphery of the inner opening of the pin hole.

2. 2. The coupling structure according to claim 1, wherein a recess is provided on the periphery of the tip of the pin body, and the tip of the flexible portion body serves as the engaging portion, which engages with the periphery of the inner opening of the pin hole when housed in the recess.

3. 3. The coupling structure according to claim 2, wherein the recess has a depth in the axial direction of the pin body that reaches the pin hole when the pin body is inserted into the pin hole, and a radial depth in which an outermost portion of the engaging portion that faces the recess is accommodated when the front pin body passes through the pin hole.

4. 4. The coupling structure according to claim 3, wherein the flexible portion is an M-shaped linear or thin plate-like member, and the central portion of the M-shape is fixed to the center of the tip portion while standing up from the tip portion of the pin body, and in an unloaded state, both ends of the M-shape are housed in the recess as the engaging portion, while the lower end thereof protrudes outward from the recess and engages with the periphery of the opening on the inner periphery side of the pin hole.

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