JP2002371546A - Connector for steel pipe pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connector that can fully acquire the connection strength of steel pipe piles with simple structure without a possibility of causing looseness and slip-off by stress due to the torque when the piles are rotationally pressed in. SOLUTION: This connector is provided with an external thread cylinder 1 and an internal thread cylinder 2. The side face of the internal thread cylinder is provided with a communicating hole 8 for communicating the inside and outside in the radial direction of the internal thread cylinder, and an external thread part is formed with a non-threaded part 6 by cutting out the screw of the external thread part facing the communicating hole in the screwed state of the internal thread cylinder and external thread cylinder. An engaging piece with the outer peripheral edge shape copying the inner peripheral edge shape of the communicating hole is provided, and the external thread cylinder and the internal thread cylinder respectively connected to steel pipe piles in advance are screwed with each other to allow the non-threaded part to face the communicating hole. The engaging piece is fitted into the communicating hole and engaged with the cutout end face of the screw around the non-threaded part. The steel pipe piles are thereby connected to each other in the locked state of the external thread cylinder and internal thread cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connector for steel pipe piles that supports a foundation of a building such as a building or a civil engineering structure.
More specifically, the present invention relates to a connector suitable for connecting a steel pipe pile for rotary press fitting.

[0002]

2. Description of the Related Art There are piles made of steel pipes that support the foundation of a building such as a building or a civil engineering structure. The steel pipe piles reach the underground supporting ground, or It is supposed to be driven into the ground while connecting a plurality of steel pipe piles to a depth where the load capacity (proof strength) can be obtained.

[0003] As shown in FIG. 8, for example, a connecting portion of a conventional steel pipe pile is formed by fitting a lower half of a relay pipe 32 into a lower steel pipe pile 31 which has been pressed into the ground first. Generally, the lower end of the new steel pipe pile 33 on the upper side is fitted around the half part, and the outward flange 32a of the relay pipe is welded to the ends of the upper and lower steel pipe piles.

[0004] The above-mentioned conventional connection portion of steel pipe piles connects the upper and lower steel pipe piles and the relay pipe by on-site welding, so that the connection strength is unstable, and welding requires skill. In addition, there is a disadvantage that welding itself cannot be performed depending on the weather at the site, or sufficient welding strength cannot be obtained even if welding can be performed.

In order to drive a steel pipe pile into the ground, rotary press-fitting, which is performed by applying pressure from the upper end of the steel pipe pile and driven into the ground, is widely performed. There is a possibility that the stress due to the rotational moment of the above will concentrate on the welded portion and the welded portion may be destroyed. If the welded portion is broken in the ground, it cannot be repaired.

[0006] In order to solve the above-mentioned problem, a male screw is formed on the outer peripheral surface of the relay pipe and a female screw is formed on the inner peripheral surface of the end of the steel pipe pile, and the direction of these screws is tightened by rotation at the time of press-fitting the pile. Some have done so.

However, when press-fitting a steel pipe pile, the pile is not always rotated in a fixed direction. For example, the lower end of the pile often hits an obstacle such as rubble in the ground. In such a case, an operation is performed in which one end of the pile is rotated backward and then rotated forward again.

Therefore, in the connection structure of the pile by screwing the relay pipe and the steel pipe pile described above, the connection portion may be loosened or disconnected when the pile is rotated in the reverse direction.

[0009]

[Purpose] The object of the present invention is to obtain sufficient connection strength of a steel pipe pile, to have a simple structure, and to prevent the pile from being loosened or dislodged due to a stress caused by a rotational moment during rotational press-fitting. An object of the present invention is to provide a connector which is unlikely to occur.

[0010]

In order to achieve the above object, a connecting device for a steel pipe pile according to the present invention comprises a cylindrical body having a connecting portion to a steel pipe pile at an upper end portion and having a male screw portion formed on an outer peripheral surface. A male screw cylinder having a connection portion to a steel pipe pile at a lower end portion, and a female screw tube formed of a cylindrical body having at least an upper portion formed with an internal thread portion screwed to the male thread portion on an inner peripheral surface, A communication hole is provided on the side surface of the female screw cylinder for communicating the inside and the outside in the radial direction of the female screw cylinder, and the thread of the male screw part facing the communication hole in a state where the female screw cylinder and the male screw cylinder are screwed is cut out to form a male screw part. An engaging piece whose outer peripheral shape follows the shape of the inner peripheral edge of the communication hole is provided, and the male screw tube and the female screw tube respectively connected to the steel pipe pile in advance are screwed together to form the screwless portion. Facing the communication hole, and fitting the engagement piece into the communication hole. By caulking engage the engagement piece in the notch end surface of the screw strip in around Munishi ridges, male screw cylinder and the female screw cylinder is detent is as steel pipe piles each other is configured to be connected.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing an embodiment of a connector according to the present invention. The connector according to the present invention includes a male screw cylinder 1, a female screw cylinder 2, and an engagement piece 3. The male screw cylinder 1 is a cylindrical body having an opening at the top and bottom, and a fitting portion 1a for fitting into a steel pipe pile at an upper end portion and a portion following the fitting portion 1a. The upper surface has a flange 1b whose upper surface is inclined downward outward, and an external thread portion 4 made of a trapezoidal screw is formed on the outer peripheral surface following the flange.

The female screw cylinder 2 is a tubular body having an opening at the top and bottom, and has, at the lower end, a fitting portion 2a for fitting into a steel pipe pile and a step portion 2b which is outwardly inclined upward following the fitting portion. A female screw portion 5 made of a trapezoidal screw is formed on the surface.

The male screw portion 4 of the male screw cylinder 1 is formed with a threadless portion 6 lacking the thread 4a, and the threadless portion is engaged with a notched end face 4b of the thread 4a. The joint piece 3 has a shape following the peripheral portion 3 a, and a female screw hole 7 is formed substantially at the center of the threadless portion 6.

Further, on the side surface of the female screw cylinder 2,
An inner peripheral edge 8a is provided with a communication hole 8 having a shape following the peripheral edge 3a of the engagement piece 3, and a cutout end face of the thread 5a in the female screw portion 5 appears on the inner edge of the communication hole.

When the male screw cylinder 1 and the female screw cylinder 2 are screwed together until the flange 1b of the male screw cylinder abuts on the upper end edge of the female screw cylinder 2, the non-thread part 6 and the communication hole 8 are formed. It is formed at a position where the outer circumference and the inner circumference of the communication hole are aligned in the radial direction,
A hole into which the engagement piece 3 is fitted is formed by the threadless portion and the communication hole.

The threadless portion and the communication hole are formed at a plurality of locations (two locations in FIGS. 1 and 4) in pairs at equal intervals in the circumferential direction of the male screw cylinder and the female screw cylinder, respectively. How many pairs of parts and communication holes are provided is determined according to the diameter and the load capacity of the steel pipe pile to which the connector is to be attached. In some cases, only one pair of the threadless portion and the communication hole may be provided. The above-described male screw cylinder 1 and female screw cylinder 2 may be manufactured by cutting,
In some cases, it is cast in a mold.

As shown in FIG. 2, the engaging piece 3 has, for example, an elliptical front shape, and has a through hole 9 substantially at the center. A tapered outer surface 9a for receiving the head of the countersunk screw 10 is formed.

The connecting device of the present invention configured as described above,
As shown in FIG. 3, a male pipe 1 is welded to a lower end of a steel pipe pile 11 and a female screw pipe 2 is welded to an upper end thereof. These male and female screw pipes are welded to the steel pipe pile in a factory or the like. Perform in a stable work environment. FIG.
Reference numeral 12 indicates a welded portion.

FIG. 4 shows a steel pipe pile 11 using the connector according to the present invention.
A and 11B show the connection state, and as described above, the female screw cylinder 2 is provided at the upper end of the lower steel pipe pile 11A previously pressed into the ground, and the lower end of the newly connected upper steel pipe pile 11B. The male screw cylinder 1 is attached to each by welding.

More specifically, wedge-shaped gaps are formed between the upper end surface of the steel pipe pile 11A and the stepped portion 2b of the female screw cylinder 2 and between the lower end surface of the steel pipe pile 11B and the upper surface of the flange 1b of the male screw cylinder 1. As a weld.

In order to connect the upper and lower steel pipe piles, the male screw cylinder 1 of the upper steel pipe pile 11B is screwed into the female screw cylinder 2 of the lower steel pipe pile 11A, and the threadless portion 6 of the male screw cylinder is connected to the female screw cylinder. The engaging piece 3 faces the inside of the communication hole and is fitted into the threadless portion from the communication hole.

The engaging piece 3 functions as a key for preventing rotation of the male screw cylinder 1 and the female screw cylinder 2, and the engagement piece has such a size that the fitting tolerance between the communication hole and the threadless portion is tight. And the engaging piece is driven into the communication hole with a tool such as a hammer.

Further, a countersunk screw 10 is inserted into the through hole 9 of the engagement piece 3 and the tip of the screw portion of the countersunk screw is screwed into the female screw hole 7 of the threadless portion 6. Seat 9a
Put in. The through hole 9 is a hole in which no thread is formed, and is not screwed with the flathead screw 10. Also, countersunk screw 1
In FIG. 4, it is sufficient that a thread is formed only at a tip portion to be screwed into the female screw hole as shown in FIG. 4, but a thread having a thread formed on the entire shaft portion may be used. .

When the steel pipe pile is rotationally press-fitted, the connector slightly deforms due to the stress caused by the rotary press-fitting. The rate of this deformation depends not only on the material and dimensions of the connector itself but also on the ground into which the pile is to be driven. Depending on various conditions such as hardness and dimensions of the pile, the engagement piece may fall off when the connecting tool is deformed.

In the embodiment described above, the engagement piece 3
Is fixed with a countersunk screw 10 screwed into the female screw hole 7 formed in the threadless portion 6 to prevent the engagement piece from falling off. However, if the stress applied to the connection tool is small, the engagement In some cases, the piece is merely fitted into the communication hole, or the blind hole 1 communicating with the through-hole 9 of the engagement piece in the threadless portion 6 as shown in FIG.
In some cases, the rivet 14 is driven into the blind hole through the through hole to prevent the engaging piece from falling off. In addition,
Although the rivet 14 shown in FIG. 5 has a head, a rivet without a head may be used in some cases.

As shown in FIG. 6, a straight hole 15 is formed in place of the female screw hole of the threadless portion 6, a screw anchor 16 is inserted through the through hole 9 of the engagement piece, and the straight hole is penetrated. In some cases, the anchor 16 may be turned to expand and engage the sheath 16 a on the inner peripheral surface of the male screw cylinder 1.

Further, in order to attach the engagement piece 3 more firmly, female screw holes 17, 17 consisting of blind holes are formed on the left and right of the communication hole 8 in the female screw cylinder 2 as shown in FIG.
In addition, a flat plate 1 is formed by holding a holding plate 18 made of a metal plate having a hole communicating with these female screw holes between the engaging piece and the holding plate.
9 and 19 are screwed into the female screw holes 17 and 17, respectively. In this case, it is not necessary to form the through hole 9 of the engagement piece 3 and the female screw hole 7 of the threadless portion 6.

If the head of the flat screw has a large diameter, the engaging piece may be directly pressed by the head of the flat screw without attaching the holding plate 18.

Although the male screw cylinder 1 in the above-described embodiment has a cylindrical shape with an opening at the top and bottom, a reinforcing material may be provided inside to increase the strength.

In the above-described embodiment, the communication hole 8 and the threadless portion 6 and the engagement pieces fitted therein have an oval front shape, but are not oblong but rectangular or other polygonal. Alternatively, the shape may be circular or elliptical.

Further, in the above-described embodiment, the threadless portion 6 is formed by cutting out a part of the thread of the male screw portion 4, and the threadless portion is formed at the same height as the root of the male screw. However, there is a case where a depression is further formed to be deeper than a root of the external thread.

[0032]

According to the connecting device of the present invention, a male screw tube and a female screw tube are provided, and the male screw tube and the female screw tube can be welded to the upper and lower ends of the steel pipe pile in advance. In this case, since the male screw cylinder and the female screw cylinder may be screwed together and the engagement piece is fitted, the steel pipe piles can be reliably and easily connected to each other.

In addition, since conventional welding of steel pipe piles at a site can be performed in a stable work environment such as a factory, the welding can be performed without being affected by the weather at the site or the skill of a welding engineer. A high welding strength can be obtained stably.

Further, since the male screw cylinder and the female screw cylinder are configured to be prevented from rotating by the engagement pieces, the problem that the connection portion is loosened or detached at first even when the pile is rotated forward and reverse at the time of press-fitting may occur. Absent.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a male screw tube and a female screw tube of a connector according to the present invention.

FIG. 2 is a perspective view showing an embodiment of the engagement piece of the connecting device according to the present invention.

FIG. 3 is a front view showing a state in which the connector according to the present invention is attached to a steel pipe pile.

FIG. 4 is a longitudinal sectional view showing a use state of the connecting device according to the present invention.

FIG. 5 is a cross-sectional view showing another example of a means for fixing an engagement piece.

FIG. 6 is a cross-sectional view showing still another example of a means for fixing an engagement piece.

FIG. 7 is a cross-sectional view showing still another example of a means for fixing an engagement piece.

FIG. 8 is a partially broken longitudinal sectional view showing a connection portion of a conventional steel pipe pile.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Male screw cylinder 2 Female screw cylinder 3 Engagement piece 4 Male screw part 5 Female screw part 6 No thread part 7 Female screw hole 8 Communication hole 9 Through hole 10 Countersunk screw 11, 11A, 11B Steel pipe pile 12 Welded part 13 Blind hole 14 Rivet 15 Straight Hole 16 Screw anchor 17 Female screw hole 18 Holding plate 19 Flat screw

Continued on the front page (72) Inventor Fujio Itagaki 583 Kaminakajima, Asahi-mura, Iwafune-gun, Niigata Prefecture (72) Inventor Atsushi Itagaki 583, Kaminakajima, Asahi-mura, Iwafune-gun, Niigata (72) Inventor Jang Bo, Shanghai, China No.2883, Fengyang Road 1803 Room F Term (Reference) 2D041 AA02 BA05 CA01 CB06 DB02 DB13 FA14

Claims (1)

[Claims] A male screw tube having a cylindrical body having an external thread formed on an outer peripheral surface thereof; and a lower end having a connection portion to the steel pipe pile. A female screw cylinder formed of a cylindrical body having at least an upper part opened and having a female screw portion screwed to the male screw portion on the surface, and a communication hole communicating radially inward and outward of the female screw cylinder on a side surface of the female screw cylinder. Along with providing the female screw tube and the male screw tube, the thread of the male screw portion facing the communication hole is cut out to form a threadless portion in the male screw portion, and the outer peripheral shape is the inner peripheral edge of the communication hole. An engaging piece that conforms to the shape is provided, and the male screw cylinder and the female screw cylinder that are respectively connected to the steel pipe pile in advance are screwed together so that the threadless portion faces the communication hole. Notch end face of thread around unthreaded part By caulking engage external thread cylinder and the internal thread cylinder are detent in connecting device for steel pipe piles consisting configured such steel piles each other are connected.