JP3194142B1 - Tensile jig for pipe laying - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To easily connect a tension member to an end of a pipe when newly inserting and laying a pipe in an existing pipe, and to connect the pipe securely without fear of damage to the end of the pipe. To provide a tension jig. SOLUTION: A screw shaft 1 provided with a locking portion 2 for locking a tension member 21 at one end, a plurality of rubber elastic bodies 3 loosely fitted on the screw shaft 1, and a rubber elastic body 3 as a shaft. Clamping members 4 and 5 arranged on the screw shaft 1 so as to sandwich from both sides in the direction.
At least one of the clamping members 4, 5 has clamping nuts 4 a, 5 a screwed to the screw shaft 1, and when the rubber elastic body 3 is inserted into the pipe end 20 a, the clamping member 5 is tightened. By tightening the attached nut 5a, the rubber elastic body 3 is squeezed to expand and deform its diameter, and is brought into pressure contact with the inner peripheral surface of the pipe 20 to be engaged by frictional force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension jig for inserting a new pipe inside a pipe such as an existing cable pipe and laying the pipe.

[0002]

2. Description of the Related Art In recent years, switching to an optical cable in an existing cable conduit or the like made of a weak pipe, such as a cast iron pipe or a concrete pipe having a low strength, in which rust or corrosion is likely to occur. For example, a pipe with excellent corrosion resistance, strength, and durability, such as a steel pipe with a highly corrosion-resistant synthetic resin laminated on both the inside and outside, or a hard polyethylene pipe wrapped with a cloth tape and steel strip around the outside. A so-called pipe-in-pipe method has been carried out in which a pipe such as a pipe formed by laminating a corrosion-resistant soft polyethylene on the outermost layer is newly inserted and laid inside the existing pipeline.

In this pipe-in-pipe method, as shown in FIG. 3, the tip of a newly inserted pipe (20) faces one manhole (31) in an existing pipe (30) and the next manhole (31). The end of a tension member (21) such as a wire rope inserted from (31) is connected to the tension member (21).
Is pulled from the next manhole (31) side by a pulling device (40) such as a winch and inserted into the pipeline (30).

At this time, as means for connecting the end of the tension member (21) to the end of the pipe (20), as shown in FIG. 4, the end (20a) of the pipe (20) is connected to its axis. It is fixed by a nut (24) through a pin (23) such as a bolt in the orthogonal direction, and the end of the tension member (21) is connected to this. At this time, a cap (25) made of wooden or synthetic resin is fitted to the end of the pipe for the purpose of connecting the tension member (21) to the axial center position and protecting the tip of the pipe.

[0005] However, in the case of the above-mentioned coupling system, the insertion hole (2
Stress tends to concentrate near 4), and even if the cap (25) is used as described above, the pipe end (20a) may be damaged. In addition, the pin (23) is a pipe (20)
Pipe (20) that can be inserted because it protrudes from the outer circumference
Must be considerably smaller in diameter than the inner diameter of the conduit (30). In addition, since the pin (23) needs to be passed in the direction perpendicular to the pipe axis and fixed with the nut (24) and further connected to the tension member (21), the connecting operation is troublesome. .

The present invention has been made in view of the above, and in a pipe-in-pipe method or the like, when a new pipe is inserted through an existing pipeline and laid, the operation of connecting a tension member to an end of the pipe is facilitated. It is another object of the present invention to provide a tension jig which can be securely connected without fear of breakage of a pipe end.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a tensioning jig for inserting and laying a pipe through an existing pipeline, wherein a screw provided with a locking portion for locking a tensioning member at one end is provided. Axis and
An annular rubber elastic body loosely fitted to the screw shaft; and a pressing member arranged on the screw shaft so as to be smaller in diameter than the rubber elastic body and to sandwich the rubber elastic body from both sides in the axial direction. At least one of the pressure members has a tightening nut screwed to the screw shaft,
By tightening the tightening nut of the one pressing member in a state where the rubber elastic body is inserted into the end of the pipe, the rubber elastic body is squeezed to expand and deform, and is pressed against the inner peripheral surface of the pipe. It is characterized in that they are combined.

According to the tension jig of the present invention having the above-described structure, when a pipe having a diameter smaller than the inner diameter of the tension jig is newly inserted into an existing pipeline, a portion of the rubber elastic body of the tension jig is connected to the pipe end. In a state where the rubber elastic body is inserted into the portion, at least one of the tightening nuts of the pressing member is tightened to expand and deform the rubber elastic body.
Thus, the outer peripheral surface of the rubber elastic body is strongly pressed against the inner peripheral surface of the pipe and is engaged by frictional force. In this way, if the end of the tension member such as the wire rope passed through the pipe from the next manhole is locked to the locking portion at the end of the screw shaft of the tension jig by the locking means such as a hook. Often, the tension member can be easily and securely connected to the pipe end. In this state, the pipe can be inserted into the pipeline by pulling the pipe with a pulling device such as a winch through a pulling member and a pulling jig. In particular, since the tension jig engages with the frictional force of the rubber elastic body that strongly presses against the inner peripheral surface of the pipe end, the pipe end can be maintained without damaging the pipe end.

In the above-mentioned tension jig, a plurality of rubber elastic bodies are arranged on the screw shaft, and a seat plate for preventing the rubber elastic bodies from sticking to each other is interposed between the rubber elastic bodies.
It is preferable to arrange a pressing member on both sides of the rubber elastic body group.

[0010] That is, by using a plurality of the rubber elastic bodies, the pressing force against the inner peripheral surface of the pipe end can be increased. In particular, by interposing a seat plate between each rubber elastic body,
When the rubber elastic bodies are squeezed by the squeezing members from both sides, the rubber elastic bodies do not come into close contact with each other and are integrated with each other. Therefore, the pipe can be pressed against the inner peripheral surface of the pipe, so that the frictional engagement can be further increased as a whole, and the pipe can be pulled with a stronger force.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described based on embodiments shown in the drawings.

FIG. 1 is a cross-sectional view of a tension jig according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a use state of the tension jig.

As shown in the drawing, the tension jig (A) of the present invention comprises a screw shaft (1) and one or more annular rubber elastic bodies (1) loosely fitted on the screw shaft (1). 3) and a pressing member (4) which is smaller in diameter than the elastic body (3) and is arranged on the screw shaft (1) so as to sandwich the rubber elastic body (3) from both sides in the axial direction.
(5).

The screw shaft (1) is provided at one end thereof with a locking portion (2) for locking a tension member (21) such as a wire rope. As this locking part (2),
As shown in the drawing, a substantially U-shaped member is attached to the end of the screw shaft (1) by welding means to form an elongated ring shape extending in the axial direction, and a hook ( twenty one
a) can be locked. In addition, a hook-shaped locking portion may be used, or a ring-shaped member may be detachably attached to the end of the screw shaft (1) by screwing means or fastening means using another nut. It is possible.

The rubber elastic body (3) is made of a rubber body having moderate elasticity and strength or a rubber-like body such as a synthetic resin having the same effect, and is a circle which can be loosely fitted to the screw shaft (1). The outer diameter is slightly smaller than the inner diameter of the pipe (20) to be inserted.
The pipe (20) is provided so that it can be deformed to be larger than the inner diameter of the pipe (20) by the pinching pressure from both axial side surfaces. In the case of the drawing, the outer peripheral surface of the rubber elastic body (3) is formed to have the same diameter over substantially the entire width in the axial direction so that the pressure contact area with the inner peripheral surface of the pipe can be increased. Of course, the outer peripheral surface of the rubber elastic body (3) may be provided with irregularities so as to increase the frictional force caused by pressing against the inner peripheral surface of the pipe, or a part may be formed in a bulging shape.

Although the rubber elastic body (3) cannot be implemented with one piece, it is not possible to obtain a strong pressing force against the pipe (20).
It is preferable that these rubber elastic bodies are provided so that they can be pressed by the pressing members (4) and (5) from both sides. In this case, between the rubber elastic bodies (3) and (3),
It is preferable to interpose a thin disk-shaped seat plate (6) having a diameter slightly smaller than the outer diameter of the rubber elastic body (3) as a spacer for preventing the elastic bodies (3) from adhering to each other.

That is, when the seating plate (6) is not provided between the rubber elastic bodies, when the rubber elastic bodies (3) and (3) are pressed from both sides, the adjacent rubber elastic bodies (3) and (3) are brought into close contact and integrated, and as if they were. As in the case of one rubber elastic body, the diameter is greatly expanded and deformed toward the center, and each rubber elastic body (3) cannot be evenly pressed against the inner peripheral surface of the pipe (20), and a strong pressing force as a whole is obtained. However, by interposing the seat plate (6) between the rubber elastic bodies as described above, the rubber elastic bodies (3) can be individually expanded without being in close contact with each other. As a result, it is possible to substantially uniformly press the inner peripheral surface of the pipe (20), thereby obtaining a stronger pressing force.

The width (thickness) of the rubber elastic body (3) in the axial direction varies depending on its outer diameter, material, elasticity and the like. The pressure contact force is good and is preferably used. The number of the rubber elastic bodies (3) varies depending on the thickness thereof, but is usually from 2 to 8, particularly preferably from 3 to 5.

The clamping members (4) and (5) are each provided with a tightening nut (4a) screwed to the screw shaft (1).
(5a) and pressing plates (4b) and (5b) that are in contact with the side surfaces of the rubber elastic bodies (3) and (3) at both axial positions of the rubber elastic body group. The rubber elastic body (3) can be pressed by tightening the tightening nut (5a) on the 2) side. The tightening nuts (4a) and (5a) are double nuts to prevent loosening. (4c) and (5c) show lock-side nuts. Further, the pressing plates (4b) and (5b) are slightly smaller in diameter than the outer diameter of the rubber elastic body (3) so that the pressing action on the rubber elastic body (3) can be performed in a well-balanced manner.
It has a slightly thick disk shape.

When the pressing members (4) and (5) both comprise the fastening nuts (4a) and (5a) and the pressing plates (4b) and (5b), as in the above-described embodiment, The rubber elastic body (3) can be pressed from its side in a well-balanced manner, and the rubber elastic body (3) can be easily replaced with another having a different diameter according to the inner diameter of the pipe, or the number thereof can be easily changed. (7) is a stopper pin for fixing the clamping member (4) at a predetermined position at the end of the screw shaft (1), and is detachable.

In addition, a tightening nut (5a) is provided only on one of the pressing members (4) and (5), for example, only the pressing member (5) on the locking portion (2) side. The clamping member (4) on the side does not have a tightening nut, and the clamping plate (4b)
It is also possible to fix only the screw shaft (1) to the embodiment (not shown). Also in this case, it is preferable that the pressure plate (4b) is provided detachably.

The above-mentioned tension jig (A) by Nokonome is used to carry out a pipe-in-pipe method for newly inserting a pipe (20) smaller than the inside diameter into an existing pipe (30). It is used to connect the tension member (21) to the end of the pipe (20). For example, in the case of the tension jig (A) of the illustrated embodiment, the pipe is formed so that a plurality of rubber elastic bodies (3) project from a locking portion (2) provided at one end of a screw shaft (1). In a state of being inserted into the end (20a) of (20), at least one of the clamping members (4) and (5), for example, the tightening nut (5a) on the locking portion (2) side is tightened. Due to the tightening, the rubber elastic bodies (3) adjacent to each other via the seat plate (6) are squeezed by the squeezing members (4) and (5), so that the respective rubber elastic bodies (3) are individually and substantially evenly deformed. The outer peripheral surface is strongly pressed against the inner peripheral surface of the pipe (20) and engaged and fixed by frictional force.

Therefore, the hook (21a), which is an engaging means having the end of a tension member (21) such as a wire rope passed through the pipe (30) from the next manhole at the end, is connected to the pipe ( 20) By locking to the locking portion (2) projecting more. The tension member (21) can be easily connected to the pipe end (20a).

In this state, the pipe (20) is pulled by the pulling device such as a winch through the pulling member (21) and the pulling jig (A), thereby connecting the pipe (20) to the conduit (30). Can be inserted. In particular, since the tension jig (A) engages with the frictional force of the rubber elastic body (3) which strongly presses against the inner peripheral surface of the pipe end (20a), the pipe end (20a) may be damaged. In addition, since each rubber elastic body (3) frictionally engages with each other, sufficient bonding strength can be maintained. Therefore, the pipe (20) can be pulled with a considerably high force as a whole.

[0025]

As described above, according to the tension jig of the present invention, when a pipe is newly inserted into an existing pipeline and laid in a pipe-in-pipe method or the like, the tension member is not attached to the end of the pipe. The connecting operation can be easily performed, and the connecting operation can be surely performed without fear of breakage of the pipe end, and the operation can be simplified. Also, since there is no portion protruding from the outer periphery of the pipe, it becomes possible to insert a pipe having a larger diameter than the conventional pipe into the pipe.

[Brief description of the drawings]

FIG. 1 is a sectional view of a tension jig according to one embodiment of the present invention.

FIG. 2 is a sectional view showing a use state of the tension jig.

FIG. 3 is an explanatory diagram of a pipe insertion state in the pipe-in-pipe method.

FIG. 4 is a vertical cross-sectional view showing a conventional connection state between a pipe and a tension member.

[Explanation of symbols]

 (1) Screw shaft (2) Locking part (3) Rubber elastic body (4) (5) Clamping member (4a) (5a) Clamping nut (4b) (5b) Clamping plate (6) Seat plate (7) Stopper Pin

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinobu Nakata 3-9-25 Kyomachibori, Nishi-ku, Osaka-shi, Osaka Japan Telecommunications Civil Engineering Co., Ltd. In-house (56) References JP-A-2000-59940 (JP, A) Open 2000-193137 (JP, A) Registered utility model 3011094 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02G 1/06 H02G 9/06

Claims (2)

(57) [Claims] 1. A tensioning jig for inserting and laying a pipe through an existing pipeline, comprising: a screw shaft provided with a locking portion for locking a tension member at one end; An annular rubber elastic body fitted therein; and a pressing member arranged on the screw shaft so as to be smaller in diameter than the rubber elastic body and to sandwich the rubber elastic body from both sides in the axial direction, at least one of the pressing members. Has a tightening nut screwed to a screw shaft, and tightens the tightening nut of the one pressing member in a state where the rubber elastic body is inserted into the end of the pipe, thereby clamping the rubber elastic body. A tensile jig for laying a pipe, wherein the tensile jig is press-fitted to expand and deform, and is pressed against and engaged with an inner peripheral surface of the pipe. 2. A plurality of rubber elastic bodies are arranged on the screw shaft,
2. A pipe laying device according to claim 1, wherein a seat plate for preventing the rubber elastic bodies from sticking to each other is interposed between the rubber elastic bodies, and clamping members are arranged on both sides of the rubber elastic bodies. Tensile jig.