JP3044243B2 - Underground cable pipeline - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground cable laying cable for laying cables such as power cables, communication cables such as telephone lines and optical fibers underground.

[0002]

2. Description of the Related Art As shown in FIG. 10, for example, a conventional cable underground pipeline has a large number of concrete or ceramics provided with a plurality of cable insertion holes (through holes) 2, 2,. The perforated pipe blocks 1, 1 ... are connected to each other in the longitudinal direction and buried, and a concrete handhole (box for insertion and branching) 4 having a lid 6 which can be opened and closed on the ground portion is provided at intervals of 20 to 30 m. Is formed by being connected to the perforated pipe block 1.

These porous tube blocks 1, 1... Are formed in a substantially rectangular parallelepiped shape, and their end faces are abutted with a sheet-like rubber packing therebetween, and are connected by being tightened via bolts and nuts. The connection between the perforated tube blocks 1 and 1 is firmly fixed. Also,
The hand hole 4 is formed into a substantially rectangular parallelepiped box shape having a size necessary for cable insertion work, and can be connected to the perforated tube block 1 by breaking the side wall portion. The connection portion with the block 1 is firmly fixed via concrete or the like.

[0004]

As described above, since the perforated tube block 1 is made of concrete or ceramic, burrs may be formed at the edges of the cable insertion holes 2, 2,. Dimensional errors occur in the positions and sizes of the holes 2, 2,.... Therefore, if the perforated tube blocks 1, 1,... Are connected only by abutting the end faces as in the prior art, when cables are inserted into the cable insertion holes 2, 2,. There is a problem that the coating of the cable may be damaged by the formed burrs or steps.

[0005] When it is necessary to form a bent pipe in order to avoid underground obstacles such as gas pipes, sewer pipes and manholes, and to install the pipes along a curved road,
A porous tube block having a bent cable insertion hole is required, and there are various problems in manufacturing and construction. In addition, as described above, the connection between the perforated pipe blocks 1 and 1 and the connection between the perforated pipe block 1 and the handhole 4 are firmly fixed via bolts and nuts, concrete, and the like. There is a problem that the connecting portion is easily broken when the ground fluidizes.

Further, conventionally, since the branch cable is led out from the handhole 4 installed at a predetermined distance, if it is necessary to lay the branch cable to a new building after the completion of the cable laying, the building is required to be installed. If it is away from the handhole 4, there is a problem that a long branch cable needs to be routed.

[0007] The present invention has been made in view of such conventional problems, it is possible to insert the cable insertion hole without damaging the cables, the connecting portion between the perforated pipe block and the insertion operation and the branching box during an earthquake or the like An object of the present invention is to provide a cable underground laying conduit that can prevent breakage and can easily lead out a branch cable from a perforated pipe block.

[0008]

SUMMARY OF THE INVENTION The features of the present invention for solving the conventional problems as described above and achieving the intended purpose are as follows.
In a cable underground pipe line in which a plurality of perforated pipe blocks having a plurality of cable insertion holes into which cables such as power cables and communication cables are inserted are connected and buried, Widening portions are provided at both ends of the cable insertion hole, and one end of a connection pipe having flexibility and having a smaller inner peripheral opening width than the cable insertion hole is fitted into the widening portion of the cable insertion hole, A cable access hole corresponding to the cable insertion hole of the perforated tube block is provided in the insertion work and branching box that can be opened and closed from the ground, and the other end of the connection pipe is fitted into the cable insertion hole, and through the connection pipe the porous tube block and said insertion operation and the branching box is flexibly connected, the
The connecting pipe has a wave in which concave and convex portions are alternately continuous in the longitudinal direction.
A bellows-shaped cylinder with a continuous cross section over the entire length
Formed in the recess at both ends of the connection pipe
O-ring is mounted .

It is preferable that a side wall of the hole tube block is provided with a branch hole recess which forms a thin wall that can be broken between the hole and the cable insertion hole.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. In FIGS. 1, 7 to 9, 10, 10,... Are reinforced concrete perforated pipe blocks which are interconnected and buried under a sidewalk or the like.
Reference numeral 0 denotes a connection pipe made of a synthetic resin for connecting the perforated pipe blocks 10, 10 with flexibility, and reference numeral 40 denotes reinforced concrete installed between the perforated pipe blocks 10, 10,. Hand hole (insertion work and branching box).

As shown in FIGS. 4 to 6, the perforated tube block 10 is formed in a substantially rectangular parallelepiped shape having a length of about 1 m, and has a plurality of cylindrical cable insertion holes 1 therein.
Are arranged in a line from top to bottom and in a straight line from the front end face to the rear end face. At the front and rear ends of the cable insertion hole 12, widened portions 13, 13 having an inner diameter larger than the intermediate portion are provided.
Each of the reference numerals 3 and 13 is formed in a tapered cylindrical shape slightly expanding outward.

On the side surface of the perforated pipe block 10, a branch hole recess 15 is provided at a position corresponding to a predetermined cable insertion hole 12, and between the branch hole recess 15 and the cable insertion hole 12 is provided. The straight thin wall 14 is formed so that it can be broken by a hammer or the like. Note that the recesses 15 for branch holes may be provided for all the cable insertion holes 12. In addition, on the top and side surfaces of the perforated tube block 10,
An insert 19 for attaching a hanging bracket or the like during transportation or construction,
19 are fixed.

[0013] connecting pipe 20, as shown in FIG. 3, the waveform cross-section recess and the projection are continuous alternately longitudinally the entire length
The connecting pipe 20 is formed in a bellows-like cylindrical shape and has rubber stoppers at the front and rear ends of the outer periphery of the connecting pipe 20.
O-rings 25 for water are mounted. The outer diameter of the connection pipe 20 is substantially equal to the inner diameter of the widened portion 13 of the cable insertion hole 12 of the perforated pipe block 10.
Of the cable insertion hole 12 is slightly smaller than the inside diameter of the cable insertion hole 12.

One end of the connection pipe 20 is connected to the widened portion 13 of the cable insertion hole 12 of the one perforated pipe block 10.
And the other end is fitted into the widened portion 13 of the cable insertion hole 12 of the other perforated pipe block 10 and is fixed with an adhesive or the like. The O-rings 25, 25 are in close contact with the inner peripheral surfaces of the widened portions 13, 13 of the cable insertion holes 12, 12, and the O-rings 2,
The penetration of water, earth and sand into the cable insertion holes 12 and 12 is prevented by the holes 5 and 25. Then, as shown in FIG. 2, each cable insertion hole 12, 12
The fitting pipes 20, 20 ... are fitted and fixed to the fitting pipes, and the perforated pipe blocks 10, 10 are connected via the connecting pipes 20, 20 ....

In addition, as shown in FIG. 1, at a position where there is no obstacle or the like and a linear installation is made, a gap is slightly opened between the end faces of the perforated tube blocks 10, 10.
The perforated tube blocks 10, 10 are relatively (compared to the bent part)
Are connected via short connecting pipes 20, 20,....

On the other hand, as shown in FIG. 8, at a position where an underground obstacle 9 such as a gas pipe, a sewage pipe, a manhole or the like is present, a predetermined interval is provided between the perforated pipe blocks 10, 10. Are relatively long (compared to the straight section) with long connecting pipes 20, 20,.
, And the long connecting pipes 20, 20,... Are bent to avoid the underground obstacle 9. Similarly, FIG.
As shown in the figure, a predetermined interval is provided between the perforated tube blocks 10, 10 even at a position where the perforated tube blocks 10, 10 are installed along a curved sidewalk or the like, and these perforated tube blocks 10, 10 are relatively long. Are connected via pipes 20, 20,.... That is, even if a perforated pipe block having a bent cable insertion hole is not used, the straight cable insertion hole 1 can be used.
A perforated tube block 10 provided with 2,12 ...
And the flexible connection pipes 20, 20,... Can easily form a bent pipe.

The handhole 40 is, as shown in FIG.
It is formed in a substantially rectangular parallelepiped box shape having a size necessary for cable insertion work, and a lid 46 that can be opened and closed from the ground is provided at the upper part. Also, the cable insertion holes 12, 12 of the perforated tube block 10 are provided on the side walls of the handhole 40.
Are provided corresponding to the cable entrance / exit holes. One end of the connection pipes 20, 20,... Are connected to the cable insertion holes 12, 12,.
, And the other ends of the connection pipes 20, 20,... Are inserted into the cable outlets 42, 42,... Of the handhole 40, and are connected to the perforated pipe block 10 through these connection pipes 20, 20,. The handhole 40 is connected.

The underground cable line constructed as described above is constituted by a perforated pipe block 10, 10.
., And the perforated pipe block 10 and the handhole 40 are connected to each other by the connecting pipe 2.
Since they are connected flexibly via 0, 20,..., They can be prevented from being damaged at the time of land subsidence, ground fluidization at the time of an earthquake, and the like.

In order to insert cables into the underground cable duct, the cables are inserted into the cable insertion holes 12, 12,... Of the perforated pipe blocks 10, 10,. Kind of insert. At this time, cable insertion holes 12, 12.
Are covered from inside by the connecting pipes 20, 20,..., And the inner diameter of the connecting pipes 20, 20,... Is slightly smaller than the inner diameter of the cable insertion holes 12, 12,. Therefore, the cables can be suitably inserted without being damaged by a portion projecting toward the inner peripheral side such as a burr or a step. Note that the cable insertion hole 12 may be formed in a corrugated shape to reduce the number of contact portions with cables.

When it is necessary to draw the cables into a new building after the completion of the cable laying, the vicinity of the branching concave portion 15 of the perforated pipe block 10 which is the shortest distance from the building is dug back and thinned. The wall 14 is crushed and removed with a hammer or the like. Then, a branch hole is opened in the side surface of the perforated tube block 10, and the branch cable can be led out from the cable insertion hole 12. In addition, the connection pipe 20
Since the cable is inserted into the end of the cable insertion hole 12, it does not become an obstacle when the branch cable is led out. Therefore, the branch cable can be laid at the shortest distance by connecting the branch cable insertion pipe 50 to the branch hole on the side surface of the perforated pipe block 10 and burying it underground.

Although the perforated tube block 10 is made of concrete in the above embodiment, it may be a perforated tube block made of ceramic.

[0022]

As described above, the underground cable laying line according to the present invention is provided with a cable access hole in a box for insertion and branching, and one end of a flexible connection pipe is connected to a perforated pipe block. And the other end of the connection pipe is inserted into the cable entry / exit hole of the insertion / branching box, so that the perforated pipe block and the insertion / branching box can be flexibly connected via the connection pipe. And the connection pipe has a concave and a convex in the longitudinal direction.
Snake with continuous wavy cross-sections over its entire length
The connection pipe is formed in a belly-like cylindrical shape,
Since the water-stopping O-ring is mounted in the recess, it is possible to prevent the connection portion from being damaged when the ground is fluidized during an earthquake.

In addition, by providing a branch hole recess forming a thin wall that can be broken between the cable insertion hole and the side wall of the perforated pipe block, it is necessary to draw the cable into a new building after the completion of the cable laying. If it becomes
The cable can be led out by breaking the thin wall of the perforated tube block at an arbitrary position to open the branch port, and the branch cable can be laid at the shortest distance.

[Brief description of the drawings]

FIG. 1 is an example of an embodiment of a cable underground laying pipe according to the present invention, and is a horizontal sectional view showing a straight line portion.

FIG. 2 is an enlarged view showing a connected state of the perforated tube blocks in FIG. 1;

FIG. 3 is an enlarged view of a connecting pipe portion in FIG. 2;

FIG. 4 is a front view of the perforated tube block shown in FIG.

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

FIG. 6 is a sectional view taken along line AA of FIG. 4;

FIG. 7 is a vertical sectional view showing a portion of a box (hand hole) for insertion and branching in the cable underground pipe shown in FIG. 1;

FIG. 8 is a vertical sectional view showing a bent portion in the cable underground laying conduit shown in FIG.

9 is a horizontal cross-sectional view showing a bent portion in the cable underground laying conduit shown in FIG.

FIG. 10 is a vertical sectional view showing an example of a conventional cable underground pipe.

[Explanation of symbols]

 Reference Signs List 9 underground obstacle 10 perforated pipe block 12 cable insertion hole 13 widened section 14 thin wall 15 branch recess 19 insert 20 connection pipe 25 O-ring 40 hand hole 42 cable entry / exit hole 46 lid 50 branch cable insertion pipe

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-182267 (JP, A) JP-A-8-223728 (JP, A) JP-A-9-130950 (JP, A) JP-A-7-182 JP-A-3-41290 (JP, A) JP-A-2-21389 (JP, U) JP-A-63-83933 (JP, U) JP-A-51-78998 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) H02G 9/00-9/12

Claims (2)

(57) [Claims] 1. A cable underground laying line in which a plurality of perforated tube blocks having a plurality of cable insertion holes into which cables such as a power cable and a communication cable are inserted are connected and buried. Widening portions are provided at both ends of the cable insertion hole of the perforated pipe block, and one end of a connection pipe having flexibility and having an inner peripheral opening width smaller than that of the cable insertion hole has the widening portion of the cable insertion hole. A cable access hole corresponding to the cable insertion hole of the perforated pipe block is provided in the insertion work and branching box that can be opened and closed from the ground, and the other end of the connection pipe is inserted into the cable insertion hole. The perforated pipe block and the insertion and branching box are flexibly connected via a connection pipe , and the connection pipe is
A wavy cross section in which concave and convex portions are alternately continued in the longitudinal direction is the entire length
Is formed in a bellows-like cylindrical shape having a continuous
O-rings for stopping water are provided in the recesses at both ends of the connection pipe.
Underground cable laying conduit characterized by being installed . 2. A cable insertion hole is provided on a side surface of the perforated tube block.
Recess for forming a thin wall that can be broken between
The underground cable laying conduit according to claim 1, further comprising :