JP4123451B2 - Cable conduit and its construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cable conduit for use in constructing a cable such as a power cable, a communication cable, or an optical fiber in the ground, and a method for constructing the conduit.
[0002]
[Prior art]
Generally, in order to embed a power cable or a communication cable in the ground, in order to avoid the influence of earth pressure or groundwater, protect the cable by passing it through a protective tube, and bundle multiple protective tubes together. The pipe is formed by converging on the nozzle and connecting the protective pipe focused by the nozzle to a hand hole for inspection made of concrete or the like installed at an important point in the ground.
[0003]
On the other hand, in recent years, establishment of a communication network using an optical fiber cable having excellent characteristics as a communication method using light is rapidly spreading for such power cables and communication cables.
The construction of the communication network using the optical fiber cable in the ground usually includes a hand hole which is a working groove, a sheath tube which accommodates the optical fiber cable, a protective tube which accommodates the sheath tube, the hand hole and the sheath tube, It is comprised by the pipe line which consists of a bell block for connecting.
[0004]
[Problems to be solved by the invention]
The construction of the communication network using the optical fiber cable is different from the power cable and the communication cable because the target of laying is different from the power cable and the communication cable. It is required to have a dense pipe structure with excellent durability and earthquake resistance.
Moreover, it is required that the construction work is easy and can be constructed at low cost.
[0005]
In view of the present situation, the present invention is sufficiently applicable to the construction of the power cable and the communication cable in the ground, and in particular, constructs a conduit for a communication network using an optical fiber cable safely and easily. It is intended to provide a cable conduit that can be used and a method for constructing the conduit.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a cable conduit according to claim 1 of the present invention is for inserting a cable through a wall surface on a connection side of a handhole arranged at a predetermined distance in the ground. The base of the bell block formed by integrating the sockets with bell mouths for individually receiving a plurality of sheath tubes is fixed, and the sockets with the bell mouths projecting from the wall surface on the connection side of the bell blocks are fixed. The sheath tube is slidably mounted from the distal end portion, and a base end portion of a protective tube provided surrounding the plurality of the sheath tubes is slidably mounted on the bell block, and the sheath tube is mounted on the bell block. And a configuration in which a conduit is formed by exchanging the protective tube with a slide.
[0007]
According to a fourth aspect of the present invention, there is provided a cable conduit construction method comprising a plurality of sheath pipes for accommodating cables between hand holes arranged at a predetermined distance in the ground, and the plurality of sheaths. When constructing a cable conduit using a protective tube that surrounds the tube, one end of the sheath tube can be slid freely in each socket with bell mouth of the bell block provided on the wall on the connection side of each hand hole. At the same time, one end of a protective tube that surrounds multiple sheath tubes is slidably attached to the outer periphery of the bell block, and protects the sheath tube from the other hand hole side sequentially to the other hand hole side. When the other ends of the sheath tube and protective tube connected from both hand holes are close to each other, slide at least one of each sheath tube toward the hand hole inside the socket with bell mouth, Mutual The sheath tubes extending from both sides by the connecting sheath tube having a length approximately equal to the interval formed by the sheath tubes are connected to each other by pulling back the slide sheath tube in the socket with the bell mouth. By sliding at least one of the protective tubes approached by the continuous arrangement, the tip portions of the protective tubes extending from both sides are secretly connected to each other.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The cable conduit according to the present invention lays a cable between a plurality of hand holes installed at a required distance in the ground, a bell block provided on a wall surface on the connection side of each hand hole, and the hand holes. A plurality of sheath tubes and protective tubes for protecting the plurality of sheath tubes. It is to be constructed.
[0009]
The hand hole is formed of resin concrete, concrete, etc., and is basically composed of a hand hole main body with an upper opening and a lid body that closes the opening. Are each provided with a mounting hole for fixing the bell block.
[0010]
The bell block fixed to the hand hole is formed by connecting a plurality of sockets with a bell mouth made of a cylindrical body having a required diameter and length in parallel with a predetermined interval, for example, on the same circumference. Are arranged with a predetermined interval between them, and these are integrally joined by resin concrete, and at least one end of each of the sockets with bell mouths is formed by projecting a predetermined length from one end surface of the bell block. However, there are no particular restrictions on the number of sockets with bell mouths to be joined.
[0011]
There are no particular restrictions on the material of each bell mouth socket that constitutes the bell block, but considering various conditions such as workability and service life, it is preferable to use plastics such as vinyl chloride resin. The sheath diameter can be appropriately selected and used.
[0012]
Each of the sockets with bell mouths is formed by reducing the inner diameter of at least the wall surface on the connection side of the hand hole from the other inner diameter to form a stepped portion, and the sheath tube inserted from the opposite side Is preferably formed so as not to protrude toward the handhole side, and the opening on the handhole side is preferably formed with a trumpet-shaped guide portion so that the cable can be smoothly inserted.
[0013]
The sheath tube for inserting and holding the cable is made of plastic such as hard polyvinyl chloride resin, and the protective tube that surrounds and protects the plurality of sheath tubes is made of flame-retardant polyethylene or polypropylene. Since the protective tube can withstand earth pressure by forming a straight tube on the inside and a so-called corrugated tube in which the tube made of spiral or concave and convex lines is integrated on the outside, it is a preferable aspect in use. is there.
[0014]
[Action]
The cable conduit of the present invention is robust because the cables are substantially double protected by housing a plurality of sheath pipes through which the individual cables are directly inserted into a single protective pipe and connecting each hand hole. Therefore, it is possible to provide a highly safe pipe line.
[0015]
In the cable pipe construction method of the present invention, a plurality of these sheath pipes are simultaneously installed in a bell mouth socket provided on a bell block in which a sheath pipe for inserting a cable is fixed to the wall surface on the connection side of the handhole. The protective pipes to be protected are respectively slidably held on the outer periphery of the bell block, and the sheath pipe and the protective pipe are slid in the connecting direction to communicate with each other. Connection can be made completely without omission.
[0016]
【Example】
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a conduit for a fiber optic cable and a method for constructing the conduit will be specifically described below with reference to the accompanying drawings.
FIG. 1 is a longitudinal sectional view schematically showing the construction of a conduit for an optical fiber cable according to the present invention. The conduit 1 for an optical fiber cable (hereinafter referred to as “the conduit 1”) is a place where a communication network is constructed. A plurality of resin-concrete handholes 2 and 2 that are installed at a required distance in the inside, and a plurality of optical fiber cables (not shown) are inserted between the handholes 2 and 2. A sheath tube 3 (shown as a single tube in the figure) and a protective tube 4 provided between the handholes 2 and 2 that collectively accommodate the plurality of sheath tubes 3 are provided.
[0017]
The sheath tube 3 for individually holding a plurality of optical fiber cables is a hard vinyl chloride resin tube, and the protective tube 4 for accommodating the plurality of the sheath tubes 3 together is formed of flame-retardant polyethylene or polypropylene, respectively. The protective tube 4 is constituted by a so-called corrugated tube in which a tube made of irregularities is integrated on the outside of a straight tube so as to withstand earth pressure.
[0018]
The attachment of the portion of the hand tube 2 of the sheath tube 3 and the protective tube 4 is performed by using the bell block 5 shown in FIGS.
[0019]
The bell block 5 has a plurality of bell mouth sockets 6, 6,... (6 in FIG. 3) made of a cylindrical body having a required diameter and length, arranged at equal intervals on the same circumference, The base ends of the sockets 6, 6... With the bell mouths are aligned in a cylindrical shape with resin concrete so that only the tip ends protrude by the required length. Is attached to the mounting hole formed in the wall surface located in the connecting direction of the hand hole 2 with its end face not protruding into the bell block 5 and fixed using resin concrete, The length of the protective tube 4 is relatively long in order to facilitate exchange by sliding in the connecting direction.
[0020]
As is apparent from FIG. 2, each of the sockets 6 with the bell mouth constituting the bell block 5 is formed with a guide portion 9 that expands from the inside to the outside on the inner peripheral surface of the opening located on the handhole 2 side. , Leaving a necessary length from the opening toward the distal end, and expanding the remaining diameter in the socket 6 with bell mouth to form a sheath tube slide portion 7. A rubber ring holding portion 8 that has a ring-shaped outer periphery and can hold a special-shaped rubber ring inside is provided. The outer surface of the sheath tube slide portion 7 and the guide portion 9 is sanded. To improve familiarity with resin concrete.
[0021]
The mutual connection of each sheath tube 3 between the handholes 2 and 2 is made by connecting sockets 13 and 13 provided with protrusions 13a as stoppers on a separate inner periphery of the center. This is done by engaging a male receiving port 12 formed on the end surface of the protective tube 4 connected to a female receiving port 11 formed on the end surface of one protective tube 4. (See Figure 4)
[0022]
When one end portion of the sheath tube 3 is inserted into the sheath tube slide portion 7 of each bell mouth socket 6 provided in the bell block 5, the end portion of each sheath tube 3 is the bulging portion of the bell mouth socket 6 respectively. It is held tightly by a rubber ring 10 mounted in the inside 8.
[0023]
Next, a protective tube 4 is mounted around each of the sheath tubes 3, 3... And a base end portion of the protective tube 4 is mounted on the outer peripheral portion of the bell block 5 protruding from the wall surface of the hand hole 2. , Until the tip part contacts the wall surface of the hand hole 2.
[0024]
On the other hand, as shown in FIG. 1, the sheath tube 3 and the protective tube 4 are attached to the other handholes 2 arranged at a required distance via the bell block 5 in the same manner as described above. , 4 is connected to the female receiving port 11 provided at the end of one protective tube 4 as described above, and the male receiving port 12 having the ridges provided at the end of the other protective tube 4. The rubber ring packing 15 inserted between the projections and recesses and the lock ring 15a for preventing the slipping are tightly and tightly connected.
[0025]
Thus, as shown in FIG. 4, when the tip ends approach each other and face each other at a predetermined interval while being sequentially connected from both hand holes 2 and 2, respectively, After mounting the socket members 13, 13, separate sheath tubes are cut to prepare a short connecting sheath tube 14 having a length equal to the distance to the central protrusion 13 a of both socket members 13, 13. The outer tube 3 (right side in FIG. 4) is slid in the direction of the arrow to widen the space between the two tube tubes 3, 3 facing each other.
[0026]
This slide is constructed so that the sheath tube 3 can be performed within the range of the sheath tube slide portion 7 formed in the socket 6 with bell mouth. In the case of FIG. What is necessary is just to slide to the right, and the connection sheath tube 14 can be interposed between the socket members 13 and 13 by this.
At that time, since the inside of the vicinity of the hand hole 2 is reduced in diameter, the sheath tube 3 that slides is prevented from moving toward the hand hole 2 beyond the tip surface.
[0027]
In this operation, the protective tubes 4 and 4 are kept at a distance that does not hinder the interposition of the connecting sheath tube 14.
[0028]
Next, as shown in FIG. 5, a connecting sheath tube 14 is interposed in a space portion widened by sliding to one side of the sheath tube 3, and one end of the connecting sheath tube 14 is connected to one socket member. 13 and then pulling the sheath tube 3 back to the original position (leftward in FIG. 5) and attaching the other end of the connecting sheath tube 14 to the other socket member 13, thereby the sheath tubes 3, 3,. .. can be connected together.
In this final stage, the end position of the sheath tube 3 returns to the original position of the sleeve tube slide portion 7 in the socket 6 with bell mouth.
[0029]
In addition, although not shown in figure, it replaces with the said sheath tube 3 and forms the enlarged diameter part which can insert the edge part of the other sheath pipe which connects to an opening part at one end, and a part of this enlarged diameter part is outside Using a sheath tube provided with a female receiving port formed with a rubber ring holding portion capable of holding a rubber ring of a special shape inside and bulging in a ring shape toward the inside. The end of the other sheath tube is inserted into the mouth to connect the sheath tube, and the end of the sheath tube that is approached by connecting from the hand holes on both sides is opposed to the female receiving port. Both ends of the connecting sheath tube 14 can be held at both the receiving ports so as to be integrally connected.
[0030]
Thus, after the connection of the six sheath tubes 3, 3... Is finished, the protective tube 4 is slid to the left as shown in FIG. By fitting the male receiving port 12 of the protective tube 4, the packing 15 and the lock ring 15 a interposed in the concave and convex portions of the male receiving port 12 are hermetically connected to form one conduit.
[0031]
Since the protective tube 4 is not fixed to the wall surface of the handhole 2 and is slidable with respect to the bell block 5, the end surface of at least one protective tube 4 is connected by the connection between the sheath tubes 3 and 3. Although it leaves | separates from the wall surface of the handhole 2 as shown in FIG. 6, it solidifies with resin concrete after installation and maintains airtightness.
[0032]
The sliding of the sheath tube 3 and the protective tube 4 may be achieved by sliding either the sheath tube or the protective tube as described above, or by sliding both the sheath tube or the protective tube. .
[0033]
The pipe line thus formed inserts an optical fiber cable from one hand hole 2 into each sheath tube 3 and pulls it out from the other hand hole 2, and sequentially executes this to establish a communication network using the optical fiber cable as expected. Can be laid in the ground.
[0034]
【The invention's effect】
The cable conduit of the present invention comprises a plurality of sheath pipes through which individual cables are directly inserted and accommodated in a single protective pipe, and a socket with a bell mouth for inserting and holding the sheath pipe. By connecting between each hand hole through the provided bell block, the cable can be substantially double protected by the sheath tube and the protective tube, and a robust and highly safe conduit can be obtained.
[0035]
On the other hand, the construction method of the cable conduit of the present invention is a socket with a bell mouth in which the sheath tube is provided on the bell block via the bell block in which the attachment of the hand hole of the sheath tube and the protection tube is fixed to the side wall of the hand hole. And the protection tube can be slid between the outer circumference of the bell block, and the final pipe line connection between the sheath tube and the protection tube can be completely exchanged by exchanging both tubes. Is something that can be done.
[0036]
The cable conduit of the present invention and its construction method are useful as underground conduits and construction methods for various cables such as power cables, communication cables and optical fiber cables. It is particularly useful when used in a pipeline for a net and its construction method.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view schematically showing the construction of an optical fiber cable conduit as a cable conduit according to the present invention.
2 is a partially cutaway side view of a bell block used in the conduit for the optical fiber cable of FIG. 1. FIG.
FIG. 3 is a side view of FIG. 2;
FIG. 4 is a partial longitudinal sectional view showing a step of constructing the optical fiber cable conduit of FIG. 1 and in a state immediately before a sheath tube is attached.
FIG. 5 is a partial longitudinal sectional view of the state immediately after the connection of the sheath tube.
FIG. 6 is a partial longitudinal sectional view showing a state after the connection of the sheath tube is finished and the connection of the protective tube is finished.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pipeline for optical fiber cables 2 Hand hole 3 Sheath tube 4 Protective tube 5 Bell block 6 Socket with bell mouth 7 Sheath tube slide part 13 Socket member 14 Connection sheath tube

Claims (5)

A bell formed by integrating a socket with a bell mouth for individually receiving a plurality of sheath tubes for inserting cables into the wall on the connection side of the hand hole arranged at a required distance in the ground The base end portion of the block is fixed, and the sheath tube is slidably mounted from the distal end portion of each socket with the bell mouth projecting from the wall surface on the connection side of the bell block, and a plurality of the sheath tubes are surrounded. The cable is characterized in that the base end portion of the provided protective tube is slidably attached to the bell block, and a conduit is formed by exchanging the sheath tube and the protective tube with respect to the bell block. Pipeline. The socket with bell mouth forms a guide part for guiding the cable in the opening located on the handhole side, and the inside from the other end opening part to the vicinity of the guide part has an inner diameter on the guide part side. The cable conduit according to claim 1, wherein the sheath pipe slide portion is formed by expanding the diameter further. The cable conduit according to claim 1, wherein the protective tube is a corrugated tube. In constructing a cable conduit using a plurality of sheath pipes that accommodate cables between hand holes arranged at a required distance in the ground, and a protective pipe that surrounds the plurality of sheath pipes, One end of a sheath tube is slidably mounted in each socket with a bell mouth of a bell block provided on the wall surface on the connection side of each hand hole, and one end portion of a protective tube provided surrounding a plurality of sheath tubes Slidably mounted on the outer periphery of the bell block, the sheath tube and the protective tube are sequentially connected from each hand hole side to the other hand hole side, and the other end portions of the sheath tube and the protective tube connected from both hand holes When the two are close to each other, at least one of the sheath tubes is slid toward the handhole inside the socket with a bell mouth, and the connecting sheath has a length approximately equal to the interval formed by the close mutual sheath tubes. By tube The sheath tubes that have been extended from the side are connected by pulling back the slidable sheath tube in the socket with the bell mouth, and then at least one of the protective tubes that have been approached by the continuous arrangement is slid to extend from both sides. A method for constructing a cable conduit characterized by secretly connecting the tips of protective pipes. The protective tube is formed by integrally connecting the sheath tubes extending from the hand holes on both sides with a connecting sheath tube, and secretly connecting the tip portions of the protective tubes to the wall surface of each hand hole. The method for constructing a cable conduit according to claim 4, wherein the base end portion is integrally fixed with resin concrete.

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