JP4425497B2 - Communication cable laying structure in underground conduit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention has a structure in which communication cables are laid in underground pipes such as sewer pipes, communication pipes, and power pipes, and more specifically, in a plurality of branch pipes connected to the main pipe of the underground pipe. About.
[0002]
[Prior art]
In recent years, IT strategies have been advocated as a national project, and the construction of high-speed / ultra-high-speed networks, which are information transmission means, has been demanded. In addition, a plan to draw a communication cable into each home, that is, a FTTH (Fiber To The Home) plan is also in progress.
[0003]
As a communication cable which is the medium, an optical fiber cable which is much superior in performance to a steel wire cable used so far has been attracting attention. An optical fiber cable is made of thin fibers of glass or plastic, uses light as an information carrier, and sends a signal obtained by digitalizing information such as sound and video (1, 0 signal). Compared to metal cables, optical fiber cables are superior in broadband, low loss, immunity to electromagnetic waves, light weight, small size, safety, and confidentiality, and can flow information amounts from tens to hundreds of times. It has excellent characteristics as a communication medium.
[0004]
In the above-mentioned FTTH plan, it is considered that the system using this optical fiber cable is used to control the area by dividing it into 200 to 500 small blocks. Specifically, in each small block, it is assumed that public facilities such as public halls and dispatch stations are used as communication bases, and optical fiber cables are laid down to each household.
[0005]
There are two methods for laying communication cables such as optical fiber cables. There are two methods: aerial and underground laying. However, the communication cable laying in the underground laying method is more space-based than the aerial method. ) And is resistant to disasters such as earthquakes and typhoons. From this point of view, the underground burial method is used to lay branch cables (communication cables) of about 24 to 200 cores in the underground conduit main from the communication base and connect the underground conduits to each other. By providing connection branch boxes in manholes, etc., branch cables (communication cables) of about 2 to 4 cores (more than collective housing) for laying to each home are branched, and they are pulled in from manholes, etc. via branch pipes. A method of laying a cable in each home has been proposed.
[0006]
In such an underground burial system, the branch pipe (attachment pipe) connected to the main pipe is already connected to each home and facility, and the upper part of the pipe is vacant and can be laid. Proposals for using sewer pipes are particularly promising as they are unlikely to interfere with their intended use.
[0007]
As a technique for laying a communication cable in an underground conduit such as a sewer pipe, a robot construction method, a saddle construction method, a sheath pipe construction method, a drain construction method, etc. for fixing the communication cable in the pipeline have been proposed. However, these construction methods are mainly related to laying in underground pipe mains.
[0008]
Next, an example of an outdoor communication cable conventionally used will be described with reference to FIGS. As shown in FIG. 11, the communication cable 65 shown in FIG. 10 includes a communication tape core wire 62 having a configuration in which 2 to 8 cores of communication strands 60 are arranged and a resin coating 61 is applied thereon. A plurality of grooves are formed on the outer peripheral surface of the plastic core 64 arranged around the line 63, and a resin coating 61 is further provided thereon. Such a communication cable 65 is very rigid and is arranged so as to be linearly arranged so that no tension is directly applied to the communication wire 60.
[0009]
On the other hand, as the indoor communication cables 67 and 68, as shown in FIG. 12, a communication cable 67 in which a communication strand 60 is accommodated in a braid 66 such as an aramid fiber and a resin film 61 is applied thereon. And the communication cable 68 etc. which gave the resin film 61 to the communication strand 60 and the steel wire 63 as shown in FIG. 13 are developed. These indoor communication cables 67 and 68 are very flexible and have a small outer diameter as compared with the outdoor communication cable 65 described above.
[0010]
[Problems to be solved by the invention]
When laying a communication cable in the sewer pipe, the communication cable passes from the sewer main to the branch pipe and digs underground from the branch pipe end of the branch pipe (in the sewage tank, residential land or on the road). Will be led to each family. However, when one communication cable is laid from a communication base such as a facility to each household through the underground conduit, the laying route is complicated, and the conventional communication cable in the straight underground conduit between manholes is difficult. Although laying has been carried out, laying in the branch pipe branched from the main pipe of the underground conduit has not been carried out due to technical difficulties.
[0011]
Technical difficulties include that the branch pipe has a small inner diameter, that the branch pipe is formed at various angles from the main pipe through the branch pipe port, and that the normal angle changes rapidly in the branch pipe. For example, a curved portion is formed. In general, since the main pipe and the branch pipe are used as lifelines to each home and facility, a communication cable must be installed so that the original functions of the main pipe and the branch pipe are not hindered. That is, at least along the inner wall of the branch pipe, the sewage flow in the pipe is not blocked. Another problem is that a communication cable that can be laid in the branch pipe is still under development. That is, the communication cable to be used has an appropriate bendability that can be laid along the branch pipe opening and the inflection part in the branch pipe, which is a junction between the main pipe and the branch pipe, strength to prevent disconnection, water resistance, Functions such as chemical resistance, weather resistance, that is, performance capable of resisting being broken by being scratched by wrinkles, and high pressure washing resistance against high pressure washing for pipe inspection are required.
[0012]
Here, if the above-mentioned indoor communication cable having a relatively flexible and small outer diameter is laid in the branch pipe as it is, the communication cable will be bent extremely at the branch pipe opening or the inflection part of the branch pipe when laying in the branch pipe. May cause disconnection. In addition, the resin film may be torn, resulting in inconvenience that water resistance and chemical resistance are lost.
[0013]
The present invention has been made in view of the above problems, and as a communication cable to be laid in an underground conduit, an appropriate bend that can be laid along a branch pipe opening and an inflection portion in the branch pipe. Of communication cables that use functions with functions such as durability, strength against disconnection, water resistance, chemical resistance, weather resistance, and high-pressure washing resistance, and do not hinder the original functions of underground conduits A structure for laying in a pipeline is provided.
[0014]
[Means for Solving the Problems]
  The underground laying structure of the communication cable according to claim 1 for solving the above-mentioned problem is characterized in that the underground pipe is a main pipe and a branch pipe branched from a branch pipe port provided in the main pipe. And the communication cable installed in the underground pipeline isStored in the guide pipe in the main pipe,At least from the branch pipe opening to the branch pipe ridge that is the end of the branch pipeDiverge from the guide tubeThe pipe is inserted into the pipe, and the allowable bending radius of the pipe is equal to or larger than the allowable bending radius of the communication cable.The guide pipe is laid in the main pipe by applying tension to the tension member accommodated therein, and is fixed to the branch pipe so as to be fitted and fixed in the branch pipe. And a slide part that protrudes from the cylindrical fixing part to the main pipe side and holds the guide pipe slidably, and is provided inside the cylindrical fixing part, and the pipe is connected to the inner wall of the branch pipe A guide member having a branch slide portion that is slidably held along the guide member.It is characterized by this. According to this configuration, the communication cable is inserted into a pipe having a bending characteristic that exceeds the allowable bending radius of the communication cable from at least the branch pipe port to the branch pipe trough, so the communication cable is extremely bent in the branch pipe. And will not break. In addition, since the communication cable is protected by the pipe, the water resistance and chemical resistance are not lost, and it is possible to prevent the cable from being hit by a hook and disconnecting it. Disconnection of the communication cable is prevented. Even when the inside of a branch pipe is cleaned by high-pressure cleaning, the communication cable does not touch the high-pressure cleaning water and is damaged and does not break. Further, since the communication cable is inserted into the pipe, a plurality of communication cables can be accommodated in one pipe. Therefore, there is no fear of hindering the pipeline function by laying a plurality of communication cables individually, and the laying operation is simplified by arranging the minimum number of pipes in the branch pipe.
  In addition, since a guide tube with a communication cable inserted therein is arranged in the main tube, and the pipe is branched from the guide tube and inserted into the branch tube, the communication cable is protected from the outside by the guide tube or the pipe. Therefore, the communication cable has a structure excellent in water resistance, chemical resistance, weather resistance, high pressure washing resistance, and the like. In addition, it is preferable to protect the branch location from a guide pipe using a branch tool.
In addition, by using a guide member, the guide pipe can be prevented from passing directly under the branch pipe, and the pipe can be installed along the inner wall of the branch pipe, thereby preventing the original function of the branch pipe from being impaired. Can do.
[0015]
  The underground cable laying structure of the communication cable according to claim 2 is as follows.The pipe is made of a flexible pipe made of stainless steel. According to this configuration, since the flexible pipe has an appropriate flexibility, the communication cable can be laid relatively easily. When the flexible pipe does not have water tightness, the communication cable can be reliably protected from water, chemicals, etc. by forming a water tight layer on the inner surface and / or outer surface thereof. This watertight layer is achieved by inserting and / or extrapolating a plastic or rubber tube to the pipe, or by applying a curable resin or a waterproof paint to the inner and / or outer surface of the pipe.
The underground cable laying structure of the communication cable according to claim 3 is characterized in that, in claim 1, the pipe is a woven fabric using a rigid wire or a monofilament yarn having a large single yarn diameter as a weft, or a rigid It is characterized by comprising a tubular fabric made of a knitted fabric or braid using a certain wire or monofilament yarn having a large single yarn diameter in the radial direction. According to this configuration, the pipe can ensure a bending characteristic that is greater than the allowable bending radius of the communication cable, and is not easily bent even at the inflection part in the underground conduit, so that the communication cable is relatively easy. Can be laid. In addition, the tubular fabric itself does not have complete watertightness, but by forming a watertight layer on the inner surface and / or outer surface thereof, the communication cable can be reliably protected from water, chemicals, and the like. This watertight layer is achieved by inserting and / or extrapolating a plastic or rubber tube to the pipe, or by applying a curable resin or a waterproof paint to the inner and / or outer surface of the pipe. Furthermore, weaving resistance can be imparted by weaving the cylindrical fabric using a yarn coated with a chemical or the like having antifungal properties.
[0016]
  Claim4The underground cable laying structure of the communication cable according to claim 1,Any one of 1-3The pipe is characterized in that one end of the pipe is housed in the guide tube and is slidably branched from the guide tube. According to this configuration, when the length of the pipe becomes longer than expected when laying the communication cable in the branch pipe, the extra length of the pipe accommodated in the guide pipe is slid and pulled up, thereby enabling communication. The cable can be protected from the outside. Thus, the communication cable is reliably protected from the outside by the guide tube or pipe. In addition, the pipe length can be prepared with a margin in the factory.
[0018]
The underground laying structure of the communication cable according to claim 5 is the inflection part of any one of claims 1 to 4, wherein the branch pipe forms an inflection portion, and the inflection of the branch pipe. A fixing member for holding the pipe along the inner wall upper surface of the branch pipe is attached to the portion.
By using the fixing member, the pipe can be installed along the substantially upper portion of the inner wall of the branch pipe in the branch pipe having the inflection portion. As a result, it is possible to prevent the function of the branch pipe from being impaired.
[0019]
The underground laying structure of the communication cable according to claim 6 is the structure according to any one of claims 1 to 5, wherein the fixing member for holding the pipe along the upper surface of the inner wall of the branch pipe is It is installed in the branch pipe near the branch pipe port.
By holding the pipe by the fixing member in the branch pipe near the branch pipe port, the pipe can be installed along substantially the upper part of the inner wall of the branch pipe. As a result, it is possible to prevent the original function of the branch pipe from being damaged. In particular, when the guide tube is arranged in the main tube, when the guide tube does not pass directly under the branch tube, that is, when the branch tube port is provided on the side surface of the main tube, there is no need to use a guide member. A configuration using only the fixing member is desirable.
[0020]
  The underground cable laying structure of the communication cable according to claim 75 or 6In,in frontThe pipe is slidable with respect to the fixing member. According to this configuration, PaSlidableHardSince it is held by the fixed member, it is possible to prevent the pipe from being disconnected by pulling the pipe with an excessive force during the laying operation of the communication cable.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, a sewer pipe is assumed as an underground pipe. However, in the present invention, the underground pipe is not limited to a sewer pipe. For example, a gas pipe using a steel pipe or a water pipe using a cast iron pipe. It can be applied to all underground pipelines such as pipelines, rainwater pipelines, and power cable pipelines. Moreover, when the manhole is not provided in the section of the underground conduit where the communication cable is laid, it is possible to implement the present invention by forming a resistance.
[0024]
  FIG. 1 is a cross-sectional view showing an example of an underground pipe laying structure of a communication cable 17 according to the present invention. The communication cable 17 is made of, for example, an optical fiber having relatively excellent characteristics as a communication medium, and is laid in the main pipe 1 of the sewer pipe between the manholes 2 and 3 and the branch pipes 4 and 5. The communication cable 17 is inserted into the pipe 16 at least from the branch pipe ports 6 and 7 to the branch pipe rods 8 and 9 at the end of the branch pipe, and is accommodated in the guide pipe 11 in the main pipe 1. . This is to provide the communication cable 17 with water resistance, chemical resistance, weather resistance, high-pressure washing resistance, and the like. The communication cable 17 branches off from the guide tube 11 and enters a branch port.6,7It is laid in the branch pipes 4 and 5 through the branch pipe rods 8 and 9, and is drawn into each household. It should be noted that another manhole may be provided between the manholes 2 and 3, and the present invention can be similarly applied even if the manhole is a communication base.
[0025]
In carrying out the present invention, in the underground pipeline, particularly in the pipeline where sewage flows in the lower part of the main pipe 1 such as a sewer or rainwater pipe, the communication cable is used in order not to impair the original function of the underground pipeline. 17 and the members used for laying the guide pipe 11 and the like are installed substantially at the top of the main pipe 1 and the branch pipe as shown in FIG. By doing so, it is possible to prevent the communication cable 17 from blocking the flow of sewage or the like, or being struck by a bottle and disconnected.
[0026]
Here, the bending characteristics of the communication cable 17 will be described. Normally, the communication cable 17 may break or lose its function when bent over a certain angle due to the material characteristics of the communication wire. The allowable bending radius is defined by the angle at this time. Among the communication cables 17, an optical fiber cable has a larger allowable bending radius than a steel wire because the strand is made of glass or plastic. For example, as shown in FIG. 13, two tension members are arranged in parallel on both sides of the communication tape core with two communication strands arranged in the center and resin coating is applied to the outside thereof. The allowable bending radius of the optical fiber cable configured as described above is approximately 35 mm, and the optical fiber is configured such that the communication tape core wire is housed in a stainless steel tube, the inside of the tube is filled with jelly, and the tube surface is further coated with a PE sheath. There is data that the allowable bending radius of the cable is approximately 80 mm. On the other hand, an optical fiber cable called a multi-type that transmits information using light refraction has a larger allowable bending radius due to its material characteristics. As described above, the allowable bending radius is defined by the type and configuration of the communication cable 17.
[0027]
In the present embodiment, the pipe 16 is made of a material having a bending characteristic that is equal to or larger than the allowable bending radius of the communication cable 17, preferably stainless steel or plastic so that the pipe 16 does not bend to less than the allowable bending radius of the communication cable 17. Made of flexible pipe. This is to prevent the pipe 16 from being bent extremely below the allowable bending radius of the communication cable 17 and damaging the communication cable 17 inserted into the pipe 16. In addition, a tubular fabric made of woven fabric, knitted fabric, or braid can be used as the pipe 16. When these are used, in order to ensure a bending characteristic that is greater than the allowable bending radius of the communication cable 17 in particular, a weft yarn is used in the case of a woven fabric, and a wire or a single yarn diameter that is separately rigid in the radial direction in the case of a knitted fabric or braid. It is preferred to use large monofilament yarns. By doing so, even when a tubular fabric is used for the pipe 16, the pipe 16 is not extremely bent even at an inflection portion or the like in the underground conduit, so the communication cable 17 can be relatively easily obtained. Can be laid.
[0028]
Furthermore, in the case where a material having no water tightness such as a flexible pipe or a cylindrical fabric made of stainless steel or plastic is used for the pipe 16, by forming a watertight layer on the inner surface and / or outer surface of the pipe 16, It becomes possible to protect the communication cable 17 from water and chemicals more reliably. This watertight layer is achieved by applying a plastic or rubber tube to the pipe 16 by insertion and / or extrapolation, or by applying a curable resin or waterproof paint to the inner surface and / or outer surface of the pipe 16. .
[0029]
The guide pipe 11 provided substantially at the upper part of the main pipe 1 is preferably made of a resin such as polyethylene and having light weight and chemical resistance, but even other materials can be selected depending on the type of underground pipe. is there.
[0030]
A tension member 21 is accommodated in the guide tube 11, and the tension member 21 is tensioned by the tension device 34 between the manholes 2 and 3 and serves to lay the guide tube 11. The tension member 21 is a long piece of rope, string, belt, or the like made of high-strength low-tensile fiber such as polyparaphenylene benzohistoxazole (PBO) fiber, aramid fiber, carbon fiber, metal fiber, or glass fiber. A body, a stainless steel wire, or the like can be used. The tension device 34 is a pair of, for example, a drum-type retractable manual winch and a hook. The tension member 21 accommodated in the guide tube 11 is fixed to the hook on one side, and the other is tensioned by the winch. The guide tube 11 is laid on the upper side in the main tube 1.
[0031]
Further, a plurality of slack preventing members 50 each having a cylindrical fixing portion 51 having a concave portion at the center portion shown in FIG. 14 are arranged at appropriate intervals in the main pipe 1 as shown in FIG. As a result, the guide tube 11 can be prevented from loosening in the inner diameter direction of the main tube 1. As shown in FIG. 15, the columnar fixing portion 51 of the slack preventing material 50 is fixed to the inner wall of the main tube 1 while accommodating the guide tube 11 in the concave portion.
[0032]
Next, the structure form of the main pipe 1 and the branch pipes 4 and 5 will be described. Generally, the main pipe 1 is at a depth of several meters from the road surface, and the branch pipe ports 6 and 7 of the branch pipes 4 and 5 are formed on the upper half surface of the main pipe 1. The branch pipes 4 and 5 rise from the branch pipe ports 6 and 7 at a steep angle (not shown), reach a branch angle 8 and 9 at a gentle angle near the ground surface.
[0033]
When the branch pipe ports 6 and 7 are provided substantially at the upper part of the main pipe 1, the guide pipe 11 is installed at a substantially upper part of the main pipe 1, and therefore passes directly under the branch pipes 4 and 5, so There is a risk of blocking the flow of sewage, etc. In this case, as shown in FIG. 2, a cylindrical fixing member 41, a slide part 31 projecting downward from the cylindrical fixing part 41, and a branch slide provided on the cylindrical fixing part 41 It is preferable to attach the guide member 30 composed of the portion 32 and the like to the branch pipe ports 6 and 7 and hold the guide tube 11 slidably on the slide portion 31. By using such a guide member 30, the guide tube does not pass directly under the branch tubes 4, 5, and the function of the branch tubes 4, 5 can be prevented from being impaired. 2 has a protruding portion 33 that covers the pipe 16 in the radial direction of the cylindrical fixing portion 41, so that no dirt is caught on the pipe 16, and even if filth accumulates on the protruding portion 33, Removed. Further, since the guide tube 11 is slidably held by the slide portion 31, the laying operation becomes relatively easy.
[0034]
On the other hand, when the branch pipe ports 6 and 7 are provided in the side surface portion of the main pipe 1, the guide pipe 11 does not pass directly under the branch pipes 4 and 5. No. Here, as shown in FIG. 3, a fixing member comprising a columnar fixing portion 43 along the inner wall of the branch pipes 4 and 5, and a slide portion 44 that slidably holds the pipe 16 and the tension member 21. 45 is attached to substantially the upper part of the branch pipes 4 and 5 in the vicinity of the branch pipes 6 and 7, and the pipe 16 and the tension member 21 are preferably held substantially at the upper part of the branch pipes 4 and 5. Since the pipe 16 is installed substantially on the inner wall of the branch pipes 4 and 5, the original function of the branch pipes 4 and 5 is not impaired. Further, since the pipe 16 is slidably held by the slide portion 44, it is possible to prevent the pipe 16 from being disconnected by pulling the pipe 16 with an excessive force during the laying operation.
[0035]
Further, when the branch pipes 4 and 5 have the inflection portions 26 whose angles change abruptly as shown in FIGS. 1 and 9 regardless of the formation positions of the branch pipe ports 6 and 7 described above. The pipe 16 into which the communication cable 17 is inserted cannot be laid along the upper portion of the inner wall of the inflection portion 26 of the branch pipes 4 and 5 simply by applying tension with the tension mechanism 34 attached to the branch pipe rods 8 and 9. . Therefore, in order to hold the pipe 16 and the like substantially on the inner walls of the branch pipes 4 and 5, the fixing member 45 including the columnar fixing portion 43 and the slide portion 44 shown in FIG. 9 is used.
[0036]
Next, the configuration in which the communication cable 17 branches from the guide tube 11 will be described in more detail with reference to FIGS.
[0037]
FIG. 4 shows a diagram in which the communication cable 17 in the guide tube 11 is taken out of the guide tube 11 through the opening 18 provided on the side surface of the guide tube 11. The guide tube 11 is a hollow tube having a substantially rectangular cross section, and the guide tube 11 is partitioned by a plurality of partition plates. A large space at the center through which the main line communication cable 17 of the main pipe 1 is passed, and a space that is divided into approximately three layers for passing the communication cable 17 and the like are formed on both sides thereof.
[0038]
In FIG. 5, the communication cable 17 inserted through the guide tube 11 is taken out of the guide tube 11 from the opening of the guide tube 11, and a branching tool 12 is mounted around the opening of the guide tube 11. The branching tool 12 serves to protect the communication cable 17 at a branching point of the communication cable 17 from the guide tube 11, that is, in the vicinity of the opening 18 of the guide tube 11. The communication cable 17 is inserted through the opening of the guide tube 11 and guided into the branch tubes 4 and 5 through the branch tool 12.
[0039]
In order to protect the communication cable 17 from the outside, it is necessary to insert the communication cable 17 into the pipe 16 from at least the branch pipe ports 6 and 7 to the branch pipe rods 8 and 9. Therefore, the configuration shown in FIGS. 4 and 5 is used when the guide member 30 shown in FIG. 2 is used, and the communication cable 17 is protected by the pipe 16 attached to the guide member 30. The pipe 16 extends through the branch slide 32 of the guide member 30 from the branch ports 6 and 7 to the branch pipe rods 8 and 9 through the branch pipes 4 and 5. The guide tube 11 is slidably held by the slide portion 31 of the guide member 30 and the communication cable 17 is inserted into the pipe 16 from the opening 18 of the guide tube 11 and led to the branch pipe rods 8 and 9. It will be drawn into each home.
[0040]
In FIG. 6, the pipe 16 into which the communication cable 17 is inserted is inserted into the guide tube 11 from one end of the guide tube 11 and slidably branches from an opening 18 formed on the side surface of the guide tube 11. Shows the situation. The pipe 16 protects the communication cable 17 from the outside, and extends to the branch pipes 8 and 9.
[0041]
In FIG. 7, a branching tool 12 having a shape different from that of FIG. 5 is attached around the opening of the guide tube 11, and a branching portion of the communication cable 17 from the guide tube 11, that is, the opening 18 of the guide tube 11. In the vicinity, the communication cable 17 is protected. A hollow cylindrical member is attached to the side of the branching tool 12, and the side surface of the guide tube 11 of the hollow cylindrical member can communicate with the space inside the branching tool 12. A pipe 16 is continuously connected to the hollow cylindrical member, protects the communication cable 17 from the outside, and extends to the branch pipe rods 8 and 9. The communication cable 17 passing through the guide tube 11 is inserted through an opening provided on the side surface of the guide tube 11, and attached to the pipe 16 via a space formed on the side surface of the guide tube 11 of the hollow cylindrical member of the branching tool 12. It will be led in and will be laid in the branch pipes 4 and 5.
[0042]
The configuration shown in FIGS. 6 and 7 is used when the guide member 30 shown in FIG. 2 is not introduced because the communication cable 17 is inserted into the pipe 16, and the pipe into which the communication cable 17 is inserted. 16 is supported on the substantially upper part of the branch pipes 4 and 5 by the fixing member 45 shown in FIG. 3, and is guided to each household.
[0043]
The opening 18 provided in the guide pipe 11 is used to draw the communication cable 17 outside the guide pipe 11 and branch it into the branch pipes 4 and 5. The number of branch pipes is formed in a range of about 1 m before and after the mouths 6 and 7. Here, it is desirable to avoid providing the opening 18 immediately below the branch pipes 4 and 5 so that the fluid from the branch pipes 4 and 5 does not flow into the opening 18. Moreover, it is preferable that the opening part 18 is previously formed in a factory etc. under the investigation result in the main pipe 1.
[0044]
FIG. 8 shows another embodiment of the arrangement of the guide tube 11 and the communication cable 17 in the guide tube 11 according to the present invention. Only the main pipe communication cable 28 is passed through the guide pipe 11, and the pipe 16 into which the communication cable 17 corresponding to the number of branch pipes is inserted is bundled and fixed to the outer circumference of the guide pipe 11. The communication cable 17 or the pipe 16 is branched from the guide pipe 11 in the vicinity of each branch pipe port 6, 7 through a branching tool 12 or a fixing band as shown in FIGS. 7 and 8. Since the guide tube 11 and the pipe 16 are only bundled with the branching tool 12 or the like, the assembly is easy, and it is possible to assemble immediately at the laying site using the data after the pipe line condition investigation described later. Very practical.
[0045]
When the number of branch pipes is larger than that of the main pipe 1, the number of traction measures to be passed through the pipelines to be described later increases and the risk of entanglement increases. Is preferably attached in a non-detachable manner. The caller facilitates and smoothes the work of taking out the communication cable 17 from the guide tube 11 through the opening 18. Various shapes such as a hook shape and a ring shape can be adopted as the shape of the caller, but at least the outer diameter of the caller is larger than the size of the opening 18 of the guide tube 11, and the communication taken out to the outside of the guide tube 11 It is important to keep the tip of the cable 17 and the like from returning to the inside of the guide tube 11. For example, as a caller, a wire in which a wire having a diameter of approximately 1 mm is combined into a spherical shape having a diameter of approximately Φ100 mm, for example, a resin ball having a diameter of approximately Φ20 mm such as a ping-pong ball can be used. In addition, the communication cable 17 or the tip of the pipe 16 may be processed into a shape that can be directly hooked or grasped.
[0046]
When the caller is connected to the communication cable 17 or the pipe 16, the communication cable 17 or the pipe 16 is pulled out from the guide tube 11 to a certain length, and is hooked or grasped from the branch pipe ports 6 and 7. It is preferable to facilitate this.
[0047]
In order to prevent the plurality of communication cables 17 and / or pipes 16 in the guide tube 11 from being entangled, the branch tube 4 in which the communication cable 17 and / or the pipe 16 is disposed in the guide tube 11 extends to each home. , 5 and preferably follow a regular placement law. That is, the communication cable 17 and the like are arranged in parallel in the width direction in the guide tube 11 so that the outermost communication cable 17 and the like can be sequentially taken out from one manhole 2 toward the inside of the main pipe 1. .
[0048]
The following is an example of a method for carrying out the present invention.
[0049]
  First, in the main pipe 1, using a TV camera or the like, the distance between the manholes 2 and 3, the distance from the manhole 2 to the branch ports 6 and 7 of the branch pipes 4 and 5 in the main pipe 1, the branch pipe 4 , 5 to the branch pipe rods 8, 9 and the depth of the branch rods 8, 9 are measured accurately. Based on the data obtained from the pipe line survey as described above, an opening 18 is provided in the guide tube 11 at a position corresponding to each branch port 6 and 7 in advance in a factory or the like, and the communication cable 17 or the pipe 16 is It is taken out from the opening 18. When the guide pipe 11 passes directly under the branch pipes 4 and 5 when the guide pipe 11 is arranged in the main pipe 1, that is, when the branch pipes 4 and 5 are provided substantially above the main pipe 1, the communication cable It is necessary to attach the guide member 30 shown in FIG. In this case, in order to improve the work efficiency at the construction site, the diameter of the cylindrical fixing portion 41 is reduced so that it can be inserted into the branch pipes 4 and 5 through the fine wires 36, and the communication cable is previously provided. 17Or pipe 16Branch slide of the guide member 30PartIt is desirable to form a call through 32.
[0050]
The guide tube 11 prepared in advance at the factory is wound around a reel drum or the like and carried into the construction site. In addition, when introducing the slack preventing material 50, the guide member 30, the fixing member 45, etc., there is a risk of being damaged by friction with the inner wall of the main pipe 1 or being caught by a step in the pipe line when moving in the main pipe 1. For this reason, it is preferable that the guide member 30 and the fixed member 45 are moved on a cart or a simple ship that can move in the main pipe 1 and then retracted at the same time as a traction measure described later.
[0051]
At the construction site, first, a traction measure is routed between the manholes 2 and 3. As a method of passing the towing measure between the manholes 2 and 3, there are a method of pushing a rigid body such as a wire, a method of flying a parachute-like wire connecting device by air pressure, a method of connecting to a self-propelled in-pipe mobile vehicle, etc. Known methods can be employed as appropriate. Further, here, a tension mechanism 34 in which a drum type winding type manual winch and a hook are paired in advance is attached to the manholes 2 and 3 and the branch pipe rods 8 and 9 of the branch pipes 4 and 5.
[0052]
Next, one end of the traction measure and the guide tube 11 are connected to one end of the main tube 1, for example, the manhole 2, the traction measure is taken from the other manhole 3, and the guide tube 11 is installed in the main tube 1. At this stage, each of the openings 18 provided in the guide tube 11 is substantially aligned with each of the branch pipe ports 6 and 7. When the guide tube 11 is pulled from one manhole 2 to the other manhole 3, the guide tube may be twisted. Therefore, a twist prevention tool may be interposed between the traction measure and the guide tube 11. When the twist preventing tool is used, the guide tube 11 is removed after being arranged in the main tube 1. When the guide tube 11 is supported using the slack preventing material 50 shown in FIG. 14, the guide tube 11 is fixed to the inner wall of the main tube 1 as shown in FIG. 15 by the columnar fixing portion 51 of the slack preventing material 50.
[0053]
  Next, the communication cable 17 is drawn into the branch pipes 4 and 5. Regarding this work, a case where it is not necessary to use the guide member 30 shown in FIG. 2 will be described first. The guide pipe 11 in the main pipe 1 is finely adjusted back and forth so that the caller at the tip of the pipe 16 or the communication cable 17 is positioned immediately below the branch pipes 4 and 5. Next, an arm-shaped gripping jig or the like is inserted from the branch rods 8 and 9, and the pipe 16 positioned near the branch pipe ports 6 and 7 is confirmed with a TV camera.Or communication cable 17Grab the caller provided at one end of the branch and take it out from the branch rods 8 and 9. Alternatively, a traction measure is routed from the branch pipe rods 8 and 9 to one end of the main pipe 1 through the branch pipes 4 and 5 and the main pipe 1, for example, the manhole 2, and the communication cable 17 or the pipe 16 and the It is also possible to lay the communication cable 17 in the branch pipes 4 and 5 by connecting the tow measures and pulling up the tow measures from the branch pipe rods 8 and 9.
[0054]
When the guide member 30 is not used, the fixing member 45 can be installed in the branch pipes 4 and 5 of the branch pipe ports 6 and 7 in order to install the pipe 16 along substantially the upper part of the inner wall of the branch pipes 4 and 5. preferable. This can prevent the original function of the branch pipes 4 and 5 from being damaged. First, the tension member 21 and the pipe 16 reaching the branch pipe rods 8 and 9 are passed through the slide portion 44 of the fixing member 45. In a state where the tension member 21 and the pipe 16 are passed through the slide portion 44, the cylindrical fixing portion 43 and the slide portion 44 of the fixing member 45 having a reduced diameter are passed through the branch pipes 4 and 5 to the branch pipe ports 6 and 7. Move. An air packer or a dedicated device may be used as an aid for this moving operation. For example, when the air packer is contracted, it is inserted from the branch pipe rods 8 and 9 into the branch pipes 4 and 5 and inserted inside the fixing member 45 so that the diameter of the air packer or the like is reduced at the location where the fixing member 45 is installed. solve. In this way, the cylindrical fixing portion 43 of the fixing member 45 is clamped by an air packer or the like and fixed to the inner walls of the branch pipes 4 and 5.
[0055]
  On the other hand, when the branch pipes 4 and 5 are provided substantially above the main pipe 1 and the guide pipe 11 passes directly under the branch pipes 4 and 5, the guide member 30 shown in FIG. 2 is used. In this case, the communication cable 17 is used in advance.Or pipe 16Branch slide of the guide member 30Part32 and the communication cable 17Or pipe 16A callout is formed at the tip of the. In the same manner as described above, the communication cable 17 is checked while checking with the TV camera.Or pipe 16Grab the tip at the tip and grab it with a jig or the like and take it out from the branch rods 8 and 9. At the same time, the guide member 30 reduced in diameter by a thin wire is inserted into the branch pipe ports 6 and 7 from the tip end portion. As an aid to the operation at this time, the above-described air packer and the like are contracted and inserted into the branch pipe ports 6 and 7 from the branch pipe rods 8 and 9 and inserted into the inner surface of the guide member 30 to be inflated. The guide member 30 may be clamped and the air packer may be pulled up and inserted into the branch pipe ports 6 and 7.
[0056]
Then, the thin wire is cut to release the reduced diameter of the cylindrical fixing portion 41 and fixed in the branch pipes 4 and 5. In this case, if an adhesive, a pressure-sensitive adhesive, or the like is applied to the outer surface of the cylindrical fixing portion 41 in advance, the guide member 30 can be reliably fixed by contact with the inner surfaces of the branch pipes 4 and 5. Alternatively, an elastic body such as rubber or sponge may be attached to the outer surface of the columnar fixing portion 41, or a tapered tapered surface may be formed at the end of the columnar fixing portion 41 and fixed by friction pressure bonding.
[0057]
Subsequently, one end of the tension member 21 accommodated in the guide tube 11 is fixed to the hook of the tension mechanism 34 attached to the manholes 2 and 3, and the other end of the tension member 21 is pulled by the winch of the tension mechanism 34. The guide tube 11 is fixed to substantially the upper part of the main tube 1. Similarly, the pipe 16 or the communication cable 17 can be laid in the branch pipes 4 and 5 using the tension mechanism 34 attached to the branch pipe rods 8 and 9.
[0058]
However, here, when the branch pipes 4 and 5 have the inflection portion 26 whose angle changes abruptly as shown in FIGS. 1 and 9, the inside of the branch pipes 4 and 5 is simply applied by the tension mechanism 34. The pipe 16 or the communication cable 17 cannot be laid along the upper part of the inner wall. In this case, by installing the fixing member 45 shown in FIG. 9 around the inflection part 26 in the branch pipes 4 and 5 as described above, also in the branch pipes 4 and 5 having the inflection part 26, It is possible to install the pipe 16 along substantially the upper part of the inner walls of the branch pipes 4 and 5. The moving means of the fixing member 45 is as described above.
[0059]
As described above, the communication cable 17 can be laid in the upper part of the main pipe 1 and the branch pipes 4 and 5 and led to each home.
[0060]
For a house where the communication cable 17 is not laid, the outer diameter is substantially equal to the outer diameter of the communication cable 17 or the pipe 16 instead of the communication cable 17 or the pipe 16 into which the communication cable 17 is inserted. It is also possible to insert a nominal line made of a string-like material such as a tube into the guide tube 11. By doing so, the call line can be easily replaced with the communication cable 17 or the pipe 16 into which the communication cable 17 is inserted in the future.
[0061]
When the call line and the communication cable 17 or the pipe 16 are exchanged, the communication cable 17 or the pipe is connected to one end of the call line laid on the branch pipe of the home where the communication cable 17 is newly laid on the manhole 2 side. 16 is connected. As this connection method, it may be abutted and crimped with a metal ring or the like, or the material of the coating or pipe 16 of the communication cable 17 and the material of the nominal line are made of plastic and the nominal line is a tube shape. The tip of the communication cable 17 is inserted into the nominal line for an appropriate length to form an overlap portion, and the portion is crimped from the outer surface by thermocompression or dielectric, and the overlap portion plastic is melted and crushed, resulting in almost a step. It is also possible to have no shape. By preventing the communication cable 17 or the like from being disconnected due to an excessive pulling force when the communication cable 17 or the pipe 16 is pulled in by making the nominal line and the communication cable 17 or the pipe 16 have substantially the same outer diameter. Can do. After connecting the communication cable 17 or the pipe 16 and the call line on the manhole 2 side in this way, the communication cable 17 or the pipe 16 is drawn into the guide pipe 11 by pulling the call line from the branch pipe rods 8 and 9. Furthermore, it can be laid in the branch pipes 4 and 5 and led to each home.
[0062]
Further, the underground cable laying structure of the communication cable 17 according to the present invention is not limited to this embodiment, and for example, the following structure can also be adopted.
(1) Temporary tension may be applied to the tension member 21 when the communication cable 17 or the like is laid, and the guide tube 11 may be laid in a substantially suspended state.
(2) When the number of branch pipes is relatively small, the communication cable 17 may be inserted into the pipe 16 and installed in the main pipe 1 without using the guide pipe 11.
(3) The configuration of the guide tube 11 is not limited to this embodiment. For example, the shape of the guide tube 11 is not a rectangle but a hollow cylinder, the partition inside the guide tube 11 is radial, or the guide tube 11 is divided into upper and lower parts. The guide tube 11 and the tension member 21 may be integrated.
(4) The configuration of other laying auxiliary members such as the guide member 30, the fixing member 45, and the slack preventing material 50 is not limited to the configuration of this embodiment.
(5) When the length between the manholes 2 and 3 is long, or when it is difficult to lay the communication cable 17 by laying down the communication cable 17 while saving the area where the houses are crowded, etc. May be used by joining a plurality of guide tubes 11 together.
[0063]
【The invention's effect】
According to the underground cable laying structure of the communication cable in the present invention, the communication cable laid in the underground pipe line has a bending characteristic that is at least the allowable bending radius of the communication cable from the branch pipe port to the branch pipe rod. Since the cable is inserted into the pipe, the communication cable is not extremely bent and disconnected in the branch pipe. In addition, since the communication cable is protected by the pipe, the water resistance and chemical resistance are not lost, and it is possible to prevent the cable from being hit by a hook and disconnecting it. Disconnection of the communication cable is prevented. Even when the inside of a branch pipe is cleaned by high-pressure cleaning, the communication cable does not touch the high-pressure cleaning water and is damaged and does not break. Further, in the main pipe, the communication cable can be protected from the outside in the same manner as described above by housing the communication cable in the guide pipe. In addition, it is possible to prevent obstructing the original function of the pipeline by installing the communication cable in the upper part of the pipeline by appropriately using laying auxiliary members such as guide members, fixing members, loosening prevention materials, etc. in the underground pipeline. it can.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of an underground cable laying structure for a communication cable according to the present invention.
FIG. 2 is a perspective view showing a state in which a guide member holds a guide tube, a communication cable, and the like.
FIG. 3 is a perspective view showing a laying state of communication cables in the main pipe and a state in which a fixing member is used in a branch pipe branched from the main pipe.
FIG. 4 is a perspective view showing a state in which a communication cable is branched from a guide tube.
FIG. 5 is a perspective view showing a state in which a communication cable is branched from a guide tube having a branching tool according to an embodiment.
FIG. 6 is a perspective view showing a state where a communication cable inserted into a pipe is branched from a guide pipe.
FIG. 7 is a perspective view showing a state in which a communication cable is branched from a guide tube having a branching tool according to another embodiment.
FIG. 8 is a perspective view showing another embodiment of the arrangement in the guide tube such as the guide tube and the communication cable according to the present invention.
FIG. 9 is a perspective view showing an embodiment of a fixing member for laying a communication cable or the like on the upper side in a branch pipe.
FIG. 10 is a cross-sectional view showing an example of an outdoor communication cable in the prior art.
FIG. 11 is a cross-sectional view showing an example of a communication tape core wire used in an outdoor communication cable in the prior art.
FIG. 12 is a cross-sectional view showing an example of an indoor communication cable in the prior art.
FIG. 13 is a cross-sectional view showing another example of an indoor communication cable in the prior art.
FIG. 14 is a perspective view showing an embodiment of a slack preventing material for preventing slack of a guide tube or the like in the main pipe.
15 is a cross-sectional view showing a state in which a guide pipe and the like are held substantially in the main pipe using the slack preventing material shown in FIG. 14 in the main pipe.
[Explanation of symbols]
1 Main
A few manholes
4,5 branch pipe
6,7 Branch port
8,9 Branch pipe
11 Guide tube
12 Bifurcation tool
16 pipes
17 Communication cable
18 opening
21 Tension member
26 inflection part
28 Mains communication cable
30 Guide member
31 Slide part
32 Branch slide part
34 Tension mechanism
41 Cylindrical fixing part
42 Tapered surface
43 Cylindrical fixing part
44 Slide part
45 Fixing member
50 Slack prevention material
51 Cylinder fixing part

Claims (7)

The underground pipeline has a main pipe and a branch pipe branched from a branch pipe port provided in the main pipe,
Communication cables installed in the ground conduit is received in the guide tube in the main, from at least the branch pipe opening to the end of the branch pipe Masuichi of the branch pipe, the pipe branching from the guide tube Entered the line,
Allowable bending radius of the pipe, permissible tolerance bend der than the radius of the communication cable,
The guide pipe is laid in the main pipe by applying tension to the tension member accommodated therein,
In the branch pipe port,
A columnar fixing portion fitted and fixed in the branch pipe;
A slide part that protrudes from the cylindrical fixing part toward the main pipe and holds the guide pipe slidably;
A communication cable comprising a branch slide portion provided inside the cylindrical fixed portion and holding the pipe slidably along the inner wall of the branch pipe, and having a guide member attached thereto Underground pipe laying structure. The underground pipe laying structure for a communication cable according to claim 1, wherein the pipe is made of a flexible pipe made of stainless steel. The pipe is a woven fabric using a rigid wire or a monofilament yarn having a large single yarn diameter as a weft, or a tubular shape made of a knitted or braid using a rigid wire or a monofilament yarn having a large single yarn diameter in the radial direction. underground conduit laying structure of the communication cable according to claim 1, characterized in that it is constituted by a fabric. The underground of the communication cable according to any one of claims 1 to 3 , wherein one end of the pipe is accommodated in the guide pipe and slidably branches from the guide pipe. Pipe-laying structure.   The branch pipe has an inflection portion whose angle changes, and a fixing member for holding the pipe along the inner wall of the branch pipe is attached to the inflection portion of the branch pipe. The underground cable laying structure of the communication cable according to any one of claims 1 to 4.   The fixing member for holding the said pipe along the inner wall of the said branch pipe is installed in the said branch pipe near the said branch pipe opening, The Claim 1 characterized by the above-mentioned. Construction structure of underground cables for communication cables. Underground conduit laying structure of the communication cable according to claim 5 or 6 for the previous SL fixing member, the pipe is characterized by a slidable.

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