JPH1141772A - Protective tube for communication cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a protective tube by which a tube body can be inserted easily into a master tube, by a method wherein the top part of every protruding wavy shape of a tube wall is formed to be a nearly flat face, and the length in the direction of its tube axis of every protruding wavy shape is constituted to be longer than the length, in the direction of the tube axis, which is formed of the bottom part of a recessed wavy shape and of wall parts on both sides of it. SOLUTION: A tube body (p) is a tube body in which a tube wall 1 is formed to be annular recessed and protruding wavy shapes in the direction of its tube axis. The top part of every protruding wavy shape part is formed to be a flat face 2 along the direction of the tube axis. The ratio of the length L in the direction of the tube axis of every flat face 2 to the sum l of lengths in the direction of the tube axis of every bottom part 3 and of wall parts 4, 5 on both sides is set at L>l. Then, a plurality of tube devices (p) are inserted into the inside of a large-diameter tube (a master-conduit formation tube) which is buried in the ground. At this time, the tube bodies (p) are inserted sequentially into the upper-part space of an already inserted tube body while they come into contact with the already inserted tube body. However, since the ratio is set at L>l, recessed parts and protruding parts are being engaged although the tube bodies whose tube walls are formed to be the recessed and protruding wavy shapes are used. Their relative movement is not obstructed. As a result, the tube body (p) can be inserted smoothly and quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of burying a communication optical fiber cable or a conductor cable in each of a plurality of cables buried underground or in a parent pipe already buried. The present invention relates to a pipe for piping in a main pipeline used for protection.

[0002]

2. Description of the Related Art Conventionally, pipes of this kind for protecting communication cables can be roughly classified into a means for bundling a required number of pipes and directly burying them in the ground or the like, and a pipe having a large diameter being buried in the ground or the like. A means for inserting the pipe into the pipe and piping the pipe has been adopted.

[0003]

When the former means, that is, means for directly burying a pipe in the ground, is advantageous in that the size and shape of the pipe are not limited. However, it is necessary that each pipe itself has a thickness and a structure having a pressure resistance capable of withstanding a large external pressure applied to the ground. On the other hand, in the case of using the latter means, that is, the means of inserting the large diameter pipe into the inside thereof, the large diameter pipe (parent pipe forming pipe) opposes the large external pressure applied to the ground. Therefore, there is an advantage that pressure resistance is not required. However,
It is necessary to have a structure which is as small as possible in diameter, thin and lightweight, and has a low insertion resistance when inserted into the main pipeline. The tube according to the present invention is intended for the latter tube.

Accordingly, the present invention is directed to a cable protection tube which is used by being inserted into such a main pipeline, and is a flexible tube having a tube wall having an irregular corrugated shape.
When inserting into the main duct, the insertion resistance is extremely low,
In other words, it is an object of the present invention to provide a tube having a structure in which the insertion resistance is extremely low, such as a straight tube having no corrugated waveform, and which can be easily inserted into the main conduit.

[0005]

The structure of the present invention for achieving the above object will be described with reference to the reference numerals used in the embodiments. The present invention is characterized in that the tube wall 1 has an irregular wave shape in the tube axis direction. The top of the convex waveform is formed on the substantially flat surface 2, and the length L of the flat surface 2 in the tube axis direction and the bottom 3 of the concave waveform and both side walls 4 and 5 forming the concave are formed. The configuration is such that the ratio to the length l in the tube axis direction satisfies L> l.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has such a configuration. In the embodiment, the tube wall 1 has an annular uneven waveform or a spiral uneven waveform. Can be implemented. The use of a synthetic resin material is advantageous in that molding is easy. The type of the resin is not particularly limited.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing a tube body according to a first embodiment of the present invention. FIG. 1 is an external view in which a part of the tube wall is cut away, and FIG. 2 is an enlarged view of a cross section of the tube wall. FIG. 3 is a perspective view showing the outer shape of the tubular body.

The tube p shown in this embodiment is a tube having a tube wall 1 having an annular uneven wave shape in which the tube wall 1 is annularly uneven in the tube axis direction. As shown in FIG. 2, the flat surface 2 is formed on the flat surface 2 along the direction, and the length L of the flat surface 2 in the tube axis direction is formed into a concave waveform, and the side wall portions on both sides forming the concave portion are formed. 4 and 5 are formed to be longer than the length l in the tube axis direction. That is, the flat surface is formed in a shape in which the ratio of the length L in the tube axis direction to the sum l of the length in the tube axis direction of the bottom portion 3 and the side wall portions 4 and 5 satisfies the relationship of L> 1. Things.

Naturally, there are several types of pipes p, large and small, and the values of typical pipes are as follows. Outer diameter = 63 mmφ, inner diameter = 50 mmφ, average thickness = 1.7 mm, length L of the flat surface in the tube axis direction L = 9.5 mm, length l = 5 of the bottom 3 and both side walls 4 and 5 in the tube axis direction .9mm.

As shown in FIGS. 4 and 5, the pipe p thus formed has a length of 200 m or 300 m, for example.
Or a large-diameter pipe buried in the ground with a length longer than that (a main pipe forming pipe), for example, a large-diameter pipe P having an inner diameter of 250 mmφ
Against, and inserting the tube p ₁ ~p ₅ of five therein. At this time, after the three pipes p ₁ , p ₂ , and p ₃ have already been inserted, or after the insertion work has been completed in advance,
When a new pipe is inserted into the upper space s of the already inserted pipes p ₁ , p ₂ , p ₃ , as in the case of inserting two other pipes p ₄ , p ₅ , a new inserted pipe p ₄ and p ₅ are sequentially inserted while being in contact with the inserted tube while the load is supported by the already inserted tube.

At this time, the newly inserted pipes p ₄ and p ₅ tend to mesh with the already inserted pipes p ₁ , p ₂ and p _{3 due} to their own weight. The body is
As described above, the length L of the flat surface in the tube axis direction is 9.5 mm, and the length l of the bottom portion 3 and the side walls 4 and 5 in the tube axis direction is 5.
Since the distance is set to 9 mm, that is, the relation of L> l is established, the concave and convex portions are engaged with each other even though the pipe walls are formed in a corrugated shape. Since the flat surfaces 2 and 2 are always in contact with each other without hindering relative movement, the tubes can be inserted very smoothly. This smoothness is the same even when the pipes p are inserted one by one.

FIG. 6 and FIG. 7 show the relationship with another large-diameter pipe.
The case where _five small-diameter pipes p _{1 to} p 5 having an outer diameter of 63 mmφ are inserted into a large-diameter pipe P of mφ, but in this case, the internal space s of the large-diameter pipe P is sufficient. Ample room remains. However, the large diameter pipe P and the small diameter pipe p
Depending on the diameter difference, there may be little room for extra space. In the case of this embodiment, although an extreme example is shown, for example, when two pipes p ₁ and p ₂ are already inserted, another three pipes p ₃ and p _{3 4,} as in the case of inserting the p _5, without stopping only the interference of each other top and bottom of the tube,
Even in the case where interference between the left and right pipes occurs, the pipe p according to the present invention is extremely smoothly formed as described above.
It can be inserted inside.

FIGS. 8 and 9 show another tube p. In the tube p shown in this embodiment, a tube in which the corrugated shape of the tube wall 1 is formed in a spiral shape. It is an example of the body. Also in the case of this pipe p, the top of the convex corrugated portion is formed on the flat surface 2 along the pipe axis direction, and the length L in the pipe axis direction is set to be a concave corrugated bottom 3 and both sides thereof. It is formed longer than the length 1 of the side wall portions 4 and 5 in the tube axis direction. That is, the ratio of the length L of the flat surface in the tube axis direction to the sum l of the lengths of the bottom portion 3 and the side wall portions 4 and 5 in the tube axis direction is L.
> L.

Although the embodiments which are considered to be representative of the present invention have been described above, the present invention is not necessarily limited to only the structures of the embodiments, and has the above-mentioned constitutional requirements according to the present invention. The present invention achieves the object of the present invention and can be appropriately modified and implemented within the range having the following effects.

[0015]

As is clear from the above description, the tube according to the present invention has a tube wall formed in an irregular wave shape, and the top of the convex wave portion has a substantially flat surface. ,
Since the ratio between the length L in the tube axis direction and the length l in the tube axis direction formed by the bottom of the concave waveform and the side walls thereof is such that L> l is satisfied, the large diameter pipe At the time of insertion, without the irregularities of the pipes mesh with each other and hinder the insertion or fall into an uninsertable state, while the pipe wall has an irregular wave shape and is a flexible tubular body The flat surfaces are always in contact with each other, so that a remarkable effect on the insertion operation that the insertion can be performed very smoothly and quickly can be expected.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a tube of a first embodiment.

FIG. 2 is an enlarged sectional view of a tube wall portion of the tube.

FIG. 3 is a perspective view of a tubular body.

FIG. 4 is a perspective view showing a use state.

FIG. 5 is a side view of FIG. 4;

FIG. 6 is a perspective view showing another use state.

FIG. 7 is a side view of FIG. 6;

FIG. 8 is a front view of a portion corresponding to FIG. 1 showing the second embodiment.

FIG. 9 is a sectional view of a portion corresponding to FIG. 2 in FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe wall 2 Flat surface 3 Valley part 4 Side wall part 5 Side wall part p Pipe body L Length of flat surface in the pipe axis direction l Length of valley part and both side wall parts in the pipe axis direction

Claims (2)

[Claims] A pipe for inserting and piping a plurality of pipes into a parent pipe, and inserting and protecting a communication cable in each of the pipes, wherein a pipe wall (1) is provided.
Are formed in an irregular wave shape in the tube axis direction, the top of the convex waveform is formed on a substantially flat surface (2), the length L of the flat surface (2) in the tube axis direction, and the bottom portion (3 ) And the length l in the tube axis direction formed by the side walls (4) and (5) forming the recessed portion is L>
A communication cable protection tube formed in a state that satisfies 1. 2. The communication cable protection tube according to claim 1, wherein the uneven waveform of the pipe wall is an annular uneven waveform.