JPH0989198A - Construction method for gas pipe housing optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously bury gas pipes and optical fibers, so as to effectively use an original function of the optical fiber to the maximum extent, by melting a film so that mutual adjacent drawing parts and a protective material may be covered after the ends are connected to each other. SOLUTION: The connecting parts on the end surfaces of gas pipes 1 are heated and melted in a state where drawing parts 4 provided on the outer peripheries on the ends of side walls 2 of the plastic gas pipes 1 are in contact with each other so as to be arranged in the same line. Protective materials 10 are formed on optical fiber core wires 3 drawn to the mutually adjacent drawing part sides, the ends are connected to each other, and then films 11 are melted so as to cover mutually adjacent drawing parts 4 and the protective materials 10. Accordingly, connection of the mutual ends of the mutually adjacent and drawn optical fiber core wires 3 can be easily performed even after the connection of the gas pipes 1 is completed. Burying of the gas pipes 1 and burying of optical fiber cables are simultaneously performed, and the signal shut-off parts of the optical fiber core wires 3 can be specified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a gas pipe containing an optical fiber cable containing an optical fiber.

[0002]

2. Description of the Related Art Generally, lifeline pipelines for gas and the like are
A conduit line leading to the supply source facility is laid under the road, and a number of supply pipes are branched from the low-pressure main pipe at the end of the conduit line to form a gas supply system for supplying gas to customers in each district.

By the way, in such a gas pipe,
If the material is a metal gas pipe, the circumference of the gas pipe body is protected by a plastic coating material to prevent corrosion.
After the end faces of the adjacent gas pipes are butted and welded to each other, the coating material is applied again to the joined portion.

Further, in the case of a plastic gas pipe (polyethylene: PE pipe), the end faces of adjacent gas pipes are butted against each other and fused.

[0005]

By the way, once the above-mentioned gas pipe is buried in the ground, it cannot be observed from the ground, and it is irregular due to ground changes or earthquakes. If there is an external force due to a large vibration and the gas pipe is damaged, etc., a search is made for a location where a gas leak has occurred, the buried gas pipe is dug up, and repair work is performed. Since it is extremely difficult to identify the cut or the like of the gas pipe, there has been a problem that the repair work for the cut or the like is hindered.

Therefore, by integrating the optical fiber cable and the gas pipe and utilizing the original communication function of the optical fiber cable, it is possible to identify the cut point of the gas pipe without digging up the gas pipe. it is conceivable that.

If such a situation can be achieved, not only the cut point of the gas pipe can be specified, but also the gas pipe and the optical fiber cable are embedded at the same time. Compared to burying the cable alone underground, it will be possible to significantly reduce the installation cost of the optical fiber cable, and it will be possible to bury the gas pipe and attach the optical fiber cable to the gas supply destination at the same time. So, for example, automatic meter reading,
It can be used for telephone, CATV, multimedia communication, etc., and it is expected that the spread of optical fiber cables can be promoted.

The present invention has been made in response to such a situation, and by embedding a gas pipe and an optical fiber at the same time, a built-in optical fiber cable capable of maximally utilizing the original function of the optical fiber. The purpose is to provide a construction method for a gas pipe.

[0009]

According to the first aspect of the present invention,
In a state in which the drawn-out portions provided on the outer periphery of the end portion of the side wall of the plastic-based gas pipe are in contact with each other so as to be aligned on the same line, the joint portion between the end faces of the gas pipe is heated and fused, Next, a protective material is formed on the optical fiber pulled out to the adjacent pulling-out portion side, these end portions are joined, and then a film is fused so as to cover both the neighboring pulling-out portions and the protective material. It is characterized by

According to a second aspect of the present invention, the end portions of the gas pipes made of metal are in contact with each other so that the drawn-out portions provided on the outer periphery of the end portions of the side walls of the gas pipes are in line with each other so as to be aligned with each other. And then a protective material is formed on the optical fiber pulled out to the adjacent extraction portion side, and after joining these end portions, a film is formed so as to cover both the adjacent extraction portions and the protective material. Is fused.

According to a third aspect of the present invention, after the end portions of the gas pipe and the branch pipe are joined to each other at their joints, the optical fiber is connected in three directions through the optical multi-branching device. An optical / electrical converter, which is a modem installed on the ground, is connected via the optical fiber.

[0012]

In the method of constructing a gas pipe with a built-in optical fiber cable according to the present invention, the drawer portions provided on the outer periphery of the end portion of the side wall of the plastic gas pipe are brought into contact with each other so as to be aligned on the same line, The joints between the end faces of the gas pipe are heated and fused, and then a protective material is formed on the optical fiber drawn to the adjacent drawer side, and after joining these ends, both adjacent draw parts Also, since the coating is fused so as to cover the protective material, it is possible to easily join the ends of the adjacent optical fibers that have been pulled out, even after the joining of the gas pipes is completed. Since it is possible to embed the gas pipe and the optical fiber cable at the same time, it is possible to identify the cut portion of the gas pipe by identifying the signal interruption portion of the optical fiber.

In the case of metal gas pipes, the end faces of adjacent gas pipes are butted to each other and joined by welding or the like, and then the ends of the optical fibers pulled out to the adjacent pull-out portions are connected in the same manner as described above. By joining to the above, not only the gas pipe and the optical fiber can be embedded at the same time, but also the cut point of the gas pipe can be specified by specifying the signal blocking part of the optical fiber.

Further, after connecting the end portions of the gas pipe and the branch pipe to each other at their joints, the optical fiber is connected in three directions through the optical multiplex splitter, and the modem installed on the ground with respect to the optical multiplex splitter. Since a certain optical / electrical converter is connected via an optical fiber, it is possible to identify the cut point of the gas pipe or branch pipe by determining the part where the signal communication between the optical multi-branch devices is interrupted. Not only can it be performed easily, but by detecting the light transmittance due to strain, not only the cut point of the gas pipe or the branch pipe but also the deformed part of the gas pipe or the branch pipe can be easily identified. Can be done.

Furthermore, since the optical fiber built into the gas pipe is used for communication, it is possible to attach the optical fiber cable to the gas supply destination at the same time as burying the gas pipe. For example, automatic meter reading, telephone, CATV, multi Since it can be used for media communication, etc., the spread of optical fiber cables can be promoted.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 show an embodiment of a method for constructing a gas pipe with a built-in optical fiber cable according to the present invention.

The gas pipe 1 shown in these figures is made of, for example, polyethylene (PE). Inside the side wall 2 of the gas pipe 1, a plurality of optical fiber core wires 3 including a core 3a having a high refractive index, a clad 3b having a low refractive index, and a protective coating 3c are embedded along the pipe axis direction of the gas pipe 1. . In the state where the optical fiber core wire 3 is embedded inside the side wall 2 of the gas pipe 1, the side wall 2 has a protective coating 3c.
Since it plays the role of, the protective coating 3c can be omitted.

Draw-out portions 4 for pulling out the end portions of the respective optical fiber core wires 3 are provided on the outer circumferences of both end portions of the side wall 2 of the gas pipe 1, and the end faces of the gas pipe 1 are butted against each other for fusion bonding. Even after this, the ends of the pulled out adjacent optical fiber core wires 3 can be easily joined.

Incidentally, the number of optical fiber core wires 3 to be embedded may be two in the upper and lower parts inside the side wall 2 of the gas pipe 1, and further, a plurality of optical fiber core wires 3 may be embedded inside the side wall 2 of the gas pipe 1 at equal intervals. Of course, when a plurality of optical fiber core wires 3 are embedded, it is possible to specify the cut-off portion of the gas pipe 1 more finely.

Here, such polyethylene (PE)
The gas tube 1 made of the above material has a plurality of optical fiber core wires 3 previously arranged inside the mold along the tube axis direction, and the polyethylene material poured into the mold is solidified and integrally molded. That is, when the gas pipe 1 is made of plastic and the optical fiber core wire 3 is made of glass, the melting temperature of the optical fiber core wire 3 is higher than the melting temperature of the gas pipe 1, so that the gas pipe 1 and the fiber core wire 3 are integrated. It is possible.

Next, a method of burying the gas pipe 1 having the above structure will be described. First, after excavating a buried hole having a predetermined depth, the gas pipe 1 is sequentially arranged in the hole. Here, when the end faces of the adjacent gas pipes 1 are butted against each other, as shown in FIG. 3, the lead-out portions 4 provided on the outer periphery of the end portions of the side walls 2 of the gas pipes 1 are aligned so as to be aligned with each other. Contact. In this state, the joint portion between the end faces of the gas pipe 1 is heated and fused.

Next, after the protective material 10 is formed on the exposed portion of the optical fiber core wire 3 drawn out to the adjacent drawing portion 4 side, these end portions are joined (the portion indicated by reference numeral 3A in FIG. 3). Further, the coating 11 is fused so as to cover both the drawn-out portions 4 and the protective material 10.

Here, when joining the ends of the optical fiber core wire 3 to each other, for example, after forming the protective material 10 on the exposed portions pulled out from both the lead-out portions 4, the ends are cut and mirror-finished. Then, the cut surfaces finished to the mirror surface are fusion-bonded to each other, and finally both the drawing portions 4 and the protective material 1 are formed.
By fusing the film 11 so as to cover 0, the joining of the ends of the optical fiber core wire 3 is completed.

At this time, the drawn-out portion 4 is located on the side wall 2 of the gas pipe 1.
Since they are provided on the outer circumferences of both end portions, the end portions of the adjacent optical fiber core wires 3 that are pulled out can be easily joined together even after the end surfaces of the gas pipe 1 are butted against each other and fused and joined.

As described above, in this embodiment, when the gas pipes 1 are buried underground, the end faces of the adjacent gas pipes 1 are butted and melt-bonded to each other and then buried inside the side wall 2 of each gas pipe 1. The end faces of the gas pipe 1 are abutted and melted by joining the ends of a plurality of adjacent optical fiber core wires 3 that are pulled out from the lead-out portions 4 provided on the outer periphery of both ends of the side wall 2 of the gas pipe 1. Even after joining, the adjacent optical fiber core wire 3 is pulled out.
Not only can you easily join the ends of the
By specifying the signal cut-off point of the optical fiber core wire 3, it becomes easy to specify the cut-off point of the gas pipe 1.

Since the burying of the gas pipe 1 and the burying of the optical fiber core wire 3 are carried out simultaneously, the optical fiber core wire 3 is formed.
It is possible to significantly reduce the installation cost of the optical fiber cable as compared with the case where the optical fiber cable with the built-in cable is buried underground alone.

Further, since the optical fiber core wire 3 built in the gas pipe 1 is used for communication, it is possible to attach the optical fiber cable to the gas supply destination at the same time as burying the gas pipe 1, for example, automatic meter reading, telephone, Since it can be used for CATV, multimedia communication, etc., the spread of optical fiber cables can be promoted.

FIG. 4 shows a method of joining the optical fiber core wires 3 when the plastic gas tube of FIG. 1 is a short tube. In the drawings to be described below, the same parts as those in FIGS.

In the structure shown in the figure, the side wall 16 of the short pipe 15 is provided.
The above-mentioned lead-out portions 4 are not provided on the outer peripheries of both ends, and the end portions of the optical fiber core wire 3 are directly pulled out on the outer peripheries of both end portions of the side wall 16.

In the case of such a short pipe 15, adjacent short pipes 1
After the end faces of 5 are abutted and melt-bonded to each other, the end portion of the optical fiber core wire 3 is pulled out as it is, and the protective material 10 is formed on the exposed portion outside the side wall 16 of the optical fiber core wire 3, and these end portions are joined together. The coating 11 is formed so as to be bonded (a portion indicated by reference numeral 3A in FIG. 3) and further cover the protective material 10.
Is fused.

As described above, in this embodiment, the short pipe 1
Since the end portions of the optical fiber core wire 3 are directly drawn to the outer circumferences of both end portions of the side wall 16 of No. 5, the fusion area of the coating film 11 can be reduced when the short tubes 15 are joined together.

5 to 7 show another embodiment in which the gas pipe is made of metal. That is, in the case of the metal gas pipe 5 shown in the figure, the melting temperature of the gas pipe 5 is higher than the melting temperature of the optical fiber core wire 3, and like the plastic gas pipe 1 described above, a resin material is poured into the mold. Since the metal pipe 5 is solidified, a plurality of optical fiber core wires 3 are attached to the outer peripheral surface of the side wall 6 of the gas pipe 5 along the pipe axial direction because the gas pipe 5 made of metal is solidified. The optical fiber core wire 3 is integrated with the gas tube 5 by attaching a plastic film 7 for preventing corrosion so as to cover the optical fiber core wire 3 on the outer peripheral surface of the side wall of the tube 5.

When burying such metal gas pipes 5, as shown in FIG. 7, after the end faces of adjacent gas pipes 5 are butted and joined together, the outer peripheral surfaces of the side walls of the respective gas pipes 5 are joined. Protective material 10 is provided on the exposed portions of the plurality of adjacent optical fiber core wires 3 that are attached and that are pulled out from the lead-out portion 8.
After forming the above, these end portions are joined to each other (a portion indicated by reference numeral 3A in FIG. 3), and further, both the drawn-out portions 8 and the protective material 10 are formed.
By fusing the film 11 so as to cover the end portions of the gas pipes 5, the end portions of the adjacent optical fiber core wires 3 can be easily joined even after the end surfaces of the gas pipes 5 are butted and joined in the same manner as described above. Can be done.

FIG. 8 shows a method of joining the optical fiber core wires in the branch pipe. As shown in the figure, a branch pipe 20 made of the same material is fusion-bonded between the gas pipes 1 made of the above-mentioned polyethylene (PE).

A plurality of optical fiber core wires 3 are embedded in each of the gas pipes 1 and the branch pipes 20, and the optical fiber core wires 3 are extended from the lead-out portion 4 provided on the outer circumference of each end.
The end of is pulled out.

Further, each gas pipe 1 and branch pipe 20
The end portion of the optical fiber core wire 3 is covered with a protective material 10A and is joined via an optical multiplex / branching device 30. The connection of the optical fiber core wire 3 through the optical multiplex / branching device 30 is a three-way connection, which enables bidirectional communication.

Further, the optical multiplex / branching device 30 between the gas pipes 1 has an optical / electrical converter 40 which is a modem installed on the ground.
Are connected, and signals are transmitted and received by using the optical signal branched by the optical multiplex / branching device 30 as a demodulation output and the electric signal as a modulation input.

Incidentally, in the figure, is a symbol indicating the connection destination of the optical fiber core wire 3. Subsequently, a method of joining the optical fiber core wires 3 in the gas pipe 1 and the branch pipe 20 having the above-described configurations will be described.

First, after excavating a buried hole having a predetermined depth, the gas pipe 1 is arranged and the branch pipe 20 is arranged between the gas pipes 1. Here, when the end faces of the adjacent gas pipes 1 are butted against each other via the branch pipe 20, the respective drawing portions 4 are brought into contact with each other so as to be aligned on the same line.
In this state, the joint portion between the end faces of the gas pipe 1 and the branch pipe 20 is heated and fused.

Next, the ends of the optical fiber core wires 3 pulled out to the adjacent pull-out portions 4 side are joined, but when the optical multiplex / branching device 30 is interposed, the optical fiber core wires 3 are joined.
After the protective material 10A is formed on the exposed portion of the optical fiber core wire 3, the optical fiber core wires 3 are connected to each other by connecting the end portion of the protective material 10A to the connection portion of the optical multiplex / divider 30.

Further, when the optical / electrical converter 40, which is a modem installed on the ground, is connected to the optical multiplex / branching device 30, the end of the optical fiber core wire 3 is pulled out to the installation location on the ground and the optical / electrical conversion is performed. Connect to electrical converter 40. Also in this case, the protective material 10A is formed on the exposed portion of the end of the optical fiber core wire 3 to protect the exposed portion of the end. As a result, the optical fiber core wire 3 can be installed at the same time when the gas pipes 1 and the branch pipes 20 are buried.

As described above, in this embodiment, the end faces of the gas pipe 1 and the branch pipe 20 are heated at their joints to fuse them, and then the optical multi-branch unit 30 and the optical multi-branch unit 30 are used. Since the optical fiber core wire 3 is connected in three directions and the optical / electrical converter 40, which is a modem installed on the ground, is connected to the optical multiplex / branching device 30, signal communication between the optical multiplex / branching devices 30 is cut off. By determining the location
It is possible to easily identify the cut point of the gas pipe 1 or the branch pipe 20.

Further, by detecting the light transmittance due to the strain, not only the cut point of the gas pipe 1 or the branch pipe 20 but also the deformed place of the gas pipe 1 or the branch pipe 20 can be easily specified. It can be carried out. In this case, the transmittance of the optical fiber core wire 3 is measured in advance at the time when the embedding of the gas pipe 1 or the branch pipe 20 is completed, and the light transmittance is measured based on the data when the periodic inspection is performed. By measuring, the cutting or deformation of the gas pipe 1 or the branch pipe 20 can be easily known. Also, an optical / electrical converter 40, which is a modem installed on the ground
It is possible to measure the transmittance of light between the respective optical / electrical converters 40 by installing each of them at a predetermined interval, and by this, the cut point of the gas pipe 1 or the branch pipe 20 can be specified. Not limited to this, it is possible to easily and surely identify the deformed portion of the gas pipe 1 or the branch pipe 20.

Further, by forming a pit for disposing the optical / electrical converter 40 and covering it with a lid, the light / electricity converter 40 can be turned on / off at each inspection.
It is not necessary to perform excavation work for making a connection with the electric converter 40. Further, not only the inspection of the gas pipe 1 and the branch pipe 20, but also the inspection of the service pipe up to each home can be performed. In this case, for example, the optical fiber core wire 3 is connected to the meter portion exposed on the ground. It becomes easier by providing points.
Furthermore, since the optical fiber core wire 3 is disposed at the same time as the gas pipe 1 is buried, it can be used as a communication line for remote monitoring and control of the governor.

[0045]

As described above, according to the method for constructing a gas pipe with a built-in optical fiber cable of the present invention, the lead-out portions provided on the outer periphery of the end portion of the side wall of the plastic gas pipe are on the same line. In the state of being brought into contact with each other in a line, the joint portions between the end faces of the gas pipe are heated and fused,
Next, a protective material was formed on the optical fiber pulled out to the adjacent drawer portion side, and after these end portions were joined together, the film was fused so as to cover both adjacent drawer portions and the protective material. Therefore, it is possible to easily join the ends of adjacent optical fibers that have been pulled out, even after finishing the joining of the gas pipes, and to bury the gas pipes and the optical fiber cables at the same time. Therefore, it is possible to specify the cut-off point of the gas pipe by specifying the signal cut-off point of the optical fiber.

In the case of a metal gas pipe, the end faces of adjacent gas pipes are butted and joined together by welding or the like. By joining to the above, not only the gas pipe and the optical fiber can be embedded at the same time, but also the cut point of the gas pipe can be specified by specifying the signal blocking part of the optical fiber.

Further, after joining the end portions of the gas pipe and the branch pipe to each other at the joint portion, the optical fiber is connected in three directions through the optical multiplex splitter, and the modem installed on the ground with respect to the optical multiplex splitter. Since a certain optical / electrical converter is connected via an optical fiber, it is possible to identify the cut point of the gas pipe or branch pipe by determining the part where the signal communication between the optical multi-branch devices is interrupted. Not only can it be performed easily, but by detecting the light transmittance due to strain, not only the cut point of the gas pipe or the branch pipe but also the deformed part of the gas pipe or the branch pipe can be easily identified. Can be done.

Furthermore, since the optical fiber built into the gas pipe is used for communication, it is possible to attach the optical fiber cable to the gas supply destination at the same time as burying the gas pipe. For example, automatic meter reading, telephone, CATV, multi Since it can be used for media communication, etc., the spread of optical fiber cables can be promoted. Therefore, by embedding the gas pipe and the optical fiber at the same time, the original function of the optical fiber can be utilized to the maximum extent.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment when a method for constructing a gas pipe with a built-in optical fiber cable of the present invention is applied to a plastic gas pipe.

2 is a side view showing the gas pipe of FIG. 1. FIG.

FIG. 3 is a cross-sectional view showing a method of constructing the gas pipe of FIG.

FIG. 4 is a cross-sectional view showing another embodiment in which the plastic gas pipe of FIG. 1 is a short pipe.

5 is a perspective view showing another embodiment in which a metal gas pipe is used in place of the plastic gas pipe of FIG.

6 is a side view showing the gas pipe of FIG. 5. FIG.

7 is a cross-sectional view showing a method of constructing the gas pipe of FIG.

FIG. 8 is a cross-sectional view showing another embodiment in which the gas pipe of FIG. 1 is branched by a branch pipe.

[Explanation of symbols]

 1,5 Gas pipe 2,6,16 Side wall 3 Optical fiber core wire 3a Core 3b Clad 3c Protective coating 4,8 Drawer 10 Protective material 11 Film 15 Short tube 20 Branch pipe 30 Optical multi-brancher 40 Optical / electrical converter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G02B 6/24 G02B 6/00 351

Claims (3)

[Claims] 1. A joint portion between the end faces of the gas pipe is heated in a state where the drawn-out portions provided on the outer periphery of the end portion of the side wall of the plastic-based gas pipe are in contact with each other so as to be aligned on the same line. Fusing, then forming a protective material on the optical fiber pulled out to the adjacent drawer portion side, after joining these end portions, so as to cover both the adjacent drawer portions and the protective material, A method for constructing a gas pipe with a built-in optical fiber cable, characterized by fusing the coating. 2. The end faces of the gas pipe made of metal are joined to each other in a state where the drawn-out parts provided on the outer periphery of the end part of the side wall of the metal gas pipe are in contact with each other so as to be aligned on the same line, and then the end faces of the gas pipe are joined together. A protective material is formed on the optical fiber pulled out to the corresponding drawn-out portion side, and after these end portions are joined together, a film is fused so as to cover both the adjacent drawn-out portions and the protective material. A method of constructing a gas pipe with a built-in optical fiber cable. 3. After the end portions of the gas pipe and the branch pipe are joined to each other at their joints, the optical fiber is connected to the optical fiber via the optical multi-branching device.
A method of constructing a gas pipe with a built-in optical fiber cable, characterized by directional connection and further connecting an optical / electrical converter, which is a modem installed on the ground, to the optical multiplex / divider via the optical fiber.