JPH0843698A - Method for laying aerial optical line - Google Patents

Abstract

PURPOSE:To provide a method capable of laying an aerial optical line by decreasing operations at an elevated place as far as possible for an aerially laid aerial pipeline. CONSTITUTION:A guiding pipeline 10 is connected to the end of the aerial pipeline 1 in a closure 5 prior to feeding of a coated optical fiber 7. The coated optical fiber is then let off from equipment placed on the ground including a force feed head 11 and an air current 12 is introduced into the force feed head 11 to feed the coated optical fiber 7 to the aerial pipeline 1. The introduction of the compressed air is stopped and the force feed head 11 is divided in two to allow a connector 9 to pass when the feeding of the coated optical fiber 7 nearly ends. The connector 9 is introduced into the guiding pipeline 10 and again the compressed air is introduced into the force feed head 11 to pass the air current, thereby, the connector 9 mounted at the coated optical fiber 7 is pulled up to the aerial closure 5 and the connector 9 is connected to a connector 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for laying an optical line suitable for constructing an optical subscriber wiring system for distributing an optical communication network to each subscriber.

[0002]

2. Description of the Related Art Various methods have been proposed for constructing an optical communication network. Among them, it is considered to construct an optical subscriber system by distributing an optical communication network from a station to each subscriber like a conventional telephone.

FIG. 9 is a schematic view of an example thereof. In the figure,
61 is a station, 62 is an underground cable, 63, 64 and 65 are electric poles, 66 is a connection box, 67 is a wiring cable, 68 is a connection box, 69 and 70 are wiring cables, 71, 72 and 73 are connection boxes, and 74, 75 is an optical drop line, and 76 and 77 are subscribers.

A wiring cable 67 connected from a station 61 through an underground cable 62 by a connection box 66 is connected to a pole-mounted type connection box 68 installed on a utility pole 63. From the connection box 68, the wiring cables 69 and 70 are sequentially routed through the telephone poles 64 and 65 to be wired in the area where the subscriber is. The wiring cables 69 and 70 are supported by a support wire stretched between electric poles, and are connected to each other by a connection box 71 on the electric pole 64, for example. The subscriber 76 in demand is withdrawn from the connection box 71 by the optical drop line 74.

In addition to being withdrawn from the connection box provided near the utility pole, the withdrawal to the subscriber may be withdrawn from the connection box 73 provided between the utility poles 64 and 65 like the subscriber 77. . Of course, it is not necessary to provide a connection box for each electric pole, and an electric pole that only holds the electric pole may be arranged.

On the other hand, as a so-called optical drop line for connecting an optical fiber in a wiring cable to extend an optical line to a subscriber and connecting it to a subscriber terminal, an optical cable with a small number of fibers containing one or two optical cables. It has been known. Therefore, the optical subscriber system is configured by pulling down the optical fiber of a small number of fibers connected in series with the optical cable of the multi-core optical cable as described above to the subscriber's house.

The above concept was known from NTT Research Practical Report Vol. 33, No. 3 (1984), pages 116 to 129, etc., but conventionally, the development of optical terminals was not sufficient. Due to the fact that the price was high, the actual use of the optical subscriber system was extremely limited. For this reason, the work of connecting an optical cable from a multi-core optical cable to a small-core optical cable is a special construction with a low frequency, and workability and economic efficiency have not been a problem.

However, with the progress of the advanced information society in recent years, the optical subscriber system is approaching the realization time, and the optical subscriber wiring system is required to be economical, workable, and expandable. Is becoming more common.

That is, as the number of optical subscriber systems expands, the number of installations increases significantly, and it is necessary to simplify the work and save labor, and at the same time, the number of optical fiber cores connected to the optical outdoor line according to the fluctuation of the demand trend. There is also a strong need for the degree of freedom.

Therefore, it is not desirable from the economical point of view to pre-wire a large number of optical fibers.
It was not preferable to lay a conventional cable with a small number of cores according to the demand trend because it would significantly increase the number of installations.

On the other hand, as a simple method for laying an optical fiber, as described in Japanese Patent Laid-Open No. 3-249704, a laying method called "blown fiber method", that is, an optical fiber core is hollowed. There was a known method of laying down the air flow on the pipes of the. But,
This method requires a lot of heavy equipment such as a compressor and a pressure feeding head as the equipment to be used, and there is a problem in using it in a fictitious manner.

The work involved in laying an aerial cable is dangerous because it is at a high place and the scaffolding is unstable, and the laying work also requires a high level of skill. Minimization of fictitious work has been strongly demanded for deployment of optical subscriber networks.

[0013]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an optical fiber can be easily laid in accordance with the demand trend, and an aerial pipeline laid aerial can be installed at a high place. It is an object of the present invention to provide a method capable of laying an aerial optical line by reducing the work of (1) as much as possible.

[0014]

In the present invention, a pipe line is preliminarily laid in an imaginary state, and a connector excellent in workability of connecting a terminal is attached to the optical fiber core wire attached to the end of the sender side. The following method is used in order to simplify the construction and to apply the blown fiber method, which has a problem in application to aerial pipelines, by laying the material by air flow.

That is, according to the first aspect of the invention, there is provided a method of laying an aerial optical line, wherein an optical fiber core wire is laid through an imaginary aerial conduit using an air flow.
A connector is previously installed at the end of the optical fiber core wire on the sender side, and a guide conduit having an inner diameter capable of transmitting the connector is joined to the sender side end of the optical fiber core wire of the overhead conduit. Then, the other end of the guide conduit is pulled down to the ground, the optical fiber core wire is guided from the ground to the aerial conduit through the guide conduit, and the air flow flowing over the entire length of the conduit connected from the device placed on the ground After passing the optical fiber, the connector is inserted into the guide conduit, and after the airflow is pulled up to near the end of the aerial conduit, the guide conduit is separated from the aerial conduit. According to the invention of claim 2, in the method of laying the aerial optical line according to claim 1, the connector of the connector is provided in the vicinity of a joint between the guide conduit and the aerial conduit. It is characterized in that a mechanism capable of stopping the passage.

According to a third aspect of the present invention, the aerial conduit is configured such that at least an aerial infeed end includes a conduit having a small inner diameter such that the inner diameter of the aerial conduit cannot pass through the connector. 5. When the air is pulled up to near the end of the aerial pipeline through the pipeline, the communication of the connector is stopped at the guide pipeline side of the small-diameter pipeline, In the invention described in (1), a blocking member that allows passage of the optical fiber and the air flow and that stops the communication of the connector is arranged near the joint between the guide pipe and the aerial pipe. According to the invention of claim 5, an extension line is attached to the connector, and the extension distance of the connector is limited by the extension line when the connector is pulled up. It is characterized in.

[0017]

According to the present invention, all the equipment of the blown fiber method can be installed on the ground, and the work of laying the optical fiber core wire can be performed by the ground work. That is, when the optical fiber is sent to the overhead conduit by the conventional blown fiber method, the pressure feed head to be placed in the overhead can be installed on the ground by applying the present invention. Also,
Since it is possible to use an optical fiber core wire equipped with a connector on the sender side, compared to the case of using an optical fiber core wire without a connector used in the conventional blown fiber method, the required fictitious optical fiber is required. The fiber fusion splicing operation can be eliminated.

Further, since the work of pulling up the connector to the overhead using the guide conduit can be done on the ground, the work of storing the extra length of the optical fiber core wire in the overhead can be eliminated. The work of pulling up the connector to the overhead is the work of placing the connector on the air flow and leading it to the overhead, but if a mechanism is provided so that the connector part that is pressure-fed stops before the overhead conduit, the connector will be suspended. The work of pulling up to can be performed only by supplying the air flow from the ground, and the work is performed on the ground, so that the work in the air can be significantly reduced. The work in the overhead is only the attachment / detachment of the guide pipeline and the overhead pipeline and the connection of the optical fiber using the connector.

As a mechanism for stopping the connector at an appropriate position, the relationship between the size of the connector and the diameter of the aerial conduit and the guide conduit is such that the connector cannot pass through the aerial conduit. The connector can be stopped at the conversion point of the diameters of the aerial conduit and the guide conduit by setting the guide conduit to a size that allows communication. This method is mentioned as a simple method. In this case, since the overhead pipeline has a small diameter, it is possible to integrate a plurality of pipelines and arrange them.

Alternatively, a blocking member may be provided as a barrier near the joint between the guide conduit and the overhead conduit to stop the connector, and the connector may be stopped there. According to this method, the connector can be parked at a position separated from the entrance of the aerial conduit by a predetermined distance. Therefore, it is effective that the extra length is not required during the subsequent connector connection work.

Alternatively, by attaching an extension wire to the connector and limiting the feed of the extension wire, the length of extension of the connector, that is, when the guide conduit is removed, the optical fiber core from the end of the overhead conduit It is possible to make the distance to the connector through the connector constant and to obtain the same effect as the above-mentioned barrier.

[0022]

EXAMPLE FIG. 7A is an example of an overhead pipeline that can be used in the present invention. In the figure, 41 is an overhead pipeline, 42 is a messenger wire, 43 is a steel core, and 44 is a mold part. The overhead pipeline 41 has, for example, an inner diameter of 12 mm and an outer diameter of 1
A 6 mm polyethylene tube is used, and is integrated with the messenger wire 42 used for the interposition and the mold part 44 to be used as a conduit cable. Mold part 44
May be provided continuously over the entire length, or may be provided intermittently. The messenger wire 42 is a twisted steel core coated with resin and has a diameter of, for example, 2 m.
Seven steel wires of m are twisted and resin-coated to a diameter of 8 mm.

FIG. 7B shows another example of the overhead pipeline which can be used in the present invention. In the figure, 41 is an overhead pipeline, 4
3 is a steel core, 45 is a tensile strength body, and 46 is a sheath. In this example, a plurality of aerial conduits 41 are twisted together with a tensile strength member 42 as a central member, and a sheath 46 is provided.
As the overhead pipeline 41, for example, an inner diameter of 4.5 mm and an outer diameter of 6
Six mm mm tubes were used. As the tension member 45,
For example, seven steel wires having a diameter of 1.2 mm were twisted together to form a steel core, which was coated with a resin and had a diameter of 6 mm. Also,
A polyethylene sheath was used as the sheath 46. In this example, a plurality of overhead pipelines are used to form a multi-strand pipeline cable.

FIG. 8 is a sectional view of various examples of the optical fiber core wire that can be used in the present invention. Any optical fiber can be used in the present invention as long as it is an optical fiber that can be fed by an air flow and can be connected to a connector at its end.
Each example will be described.

In FIG. 8 (A), an optical fiber 50 having a diameter of 0.25 mm is obtained by coating an optical fiber element wire having a diameter of 0.125 mm, and one of the optical fibers 50 is used as a center to surround 6 fibers.
The books are twisted together, a nylon inner sheath 51 is applied thereon to have a diameter of 1 mm, and a foamed polyethylene outer cover 52 is further applied thereon to make the diameter 2 mm.

In FIG. 8 (B), an outer cover 52 made of foamed polyethylene is applied on the two-core tape core wire 53 so as to have a diameter of 1.5 mm. The size of the two-core tape core wire is
It is 0.4 mm × 0.7 mm.

FIG. 8C shows two four-core tape core wires 54.
On the top of the polyethylene cover 52 of diameter 1.8 mm
It was applied so that The dimensions of the four-core tape core wire are 0.4 mm × 1.1 mm.

In FIG. 8D, with the interposition cord 55 as the center,
The optical fiber element wire having a diameter of 0.125 mm is coated and four optical fibers 50 having a diameter of 0.25 mm are twisted together, and the ultraviolet curable resin 56 is coated thereon to a diameter of 1 mm, and the surface friction coefficient is Glass particles 5 to make it smaller
7 is attached. The glass particles 57 are spherical particles having a diameter of about several μm to 10 μm, and are mixed with an ultraviolet curable resin, applied on the surface, and then cured. The glass particles 57 can reduce the friction coefficient of the surface.

FIG. 8E shows the same diameter of 0.125 mm.
2 optical fibers 50 having a diameter of 0.25 mm are provided by coating the optical fiber strand of No. 2, and an inner sheath of an ultraviolet curable resin is applied to have a diameter of 0.6 mm, and a lubricant layer of 50 μm is provided thereon. It is provided thick.

As described above, the optical fiber core wire that can be used in the present invention is a single core wire coated with foamed polyethylene, a group of tape core wires, or a group of optical fibers with smoothness. Various optical fiber core wires can be used, such as a jacket whose surface is treated to impart the above.
Of course, the optical fiber core wire described in FIG. 7 is an example, and specific numerical values and materials are not limited to the above description. Optical fibers other than the structure shown in FIG. 7 can also be used in the present invention.

FIG. 1 is an explanatory view showing the concept of the final state in the laying method of one embodiment of the present invention. 1, 2 in the figure
Is an overhead conduit, 3 is a tensile strength wire, 4 is a power pole, 5 is a closure, 6 and 7 are optical fiber core wires, 8 and 9 are connectors, 10
Is a guide pipe line, 11 is a pressure feed head, and 12 is an air flow.
The aerial conduits 1 and 2 are aerially stretched by an appropriate method such as being suspended on a tensile strength wire 3 by a utility pole 4 or the like. A closure 5 is provided at the connection point between the overhead pipelines 1 and 2,
The ends of the overhead pipelines 1 and 2 open into the closure 5. The optical fiber core wire 6 to which the connector 8 is attached is already laid in the overhead conduit 2, and the connector 8 is
It is stored in the closure 5 with some extra length. Before the optical fiber core wire 7 is sent, the guide line 10 is connected to the end of the aerial line 1 in the closure 5, and the pressure feed head 1 is connected.
1 from the equipment placed on the ground, the optical fiber core wire is fed out, the air flow 12 is introduced into the pumping head 11, and the optical fiber core wire 7 is sent to the overhead conduit 1 via the guide conduit 10. Pass through.

FIG. 2 shows an embodiment of equipment installed on the ground. In the figure, the same parts as those in FIG. 13 is a compressor, 14 is a dryer,
Reference numeral 15 is a supply reel. An optical fiber core wire 7 to which a connector 9 such as an MT type connector is attached is wound around a supply reel 15, and is fed from a pressure feed head 11 to a guide conduit 1.
Pumped to zero. The pressure feed head 11 includes a compressor 1
The compressed air from 3 has been dehumidified by the dryer 14 and introduced.

Returning to FIG. 1, the situation at the end of pressure feeding will be described. When the pressure feeding of the optical fiber core wire 7 approaches the end, the introduction of the compressed air is stopped and the pressure feeding head 11 is divided into two to pass through the connector 9 or the pressure feeding head 11 depending on the structure of the pressure feeding head 11. The connector 9 is attached to the optical fiber core wire 7 by guiding the connector 9 into the guide conduit 10 by introducing the compressed air into the pressure feeding head 11 again and flowing an air flow. 9 is pulled up to the imaginary closure 5. Finally, the guide conduit 10 is removed, and the pulled-up connector 9 is connected to the connector 8 attached to the existing optical fiber core wire 6 to complete the installation work.

Thus, by using the guide conduit,
It is possible to lay an optical fiber core and pull the connector upright while the transmission equipment is placed on the ground. Although the optical fiber 6 has been described as an existing one, the optical fiber 6 may be newly installed as the same work by the method described above.

FIG. 3 is a perspective view of the optical fiber core wire and the MT type connector. A connector 9 is provided at the end of the optical fiber core wire 7.
Is attached. A guide pin hole 16 is provided on the end face of the connector 9, and an end face 17 of the optical fiber is exposed between them. In one example, the diameter of the optical fiber core wire 7 is 2
mm, and the maximum cross section of the connector 9 is 4 × 8 mm.

FIG. 4 is an explanatory view of an embodiment of the guide conduit. In the figure, the same parts as those in FIG. 18 is a pressure feeding nozzle, 19 is a blind plug, 2
Reference numeral 0 is a joint portion, and 21 is a seal rubber. Pumping head 11
The inlet of the optical fiber core wire of the pressure feeding nozzle 18 has a large diameter hole through which the connector 9 can pass, and is closed by a blind plug 19 in the figure. At the time of pressure feeding of the optical fiber core wire, instead of the blind plug 19, a seal rubber 21 having an optical fiber feeding hole at the center is attached. The seal rubber 21 can be attached to and detached from the seal rubber 21 by making a cut from the side surface to the optical fiber through hole or by making the slit separable. To send the connector 9,
With the exception of the seal rubber, the connector is fed, and a blind plug 19 is provided in the introduction hole as shown in the figure, so that the air flow 12 is allowed to flow only to the guide conduit 10 side. It is possible to prevent the compressed air flow from being ejected from the introduction port of the optical fiber core to the outside, and to reduce the size of the air flow supply system. The splicing part 20 has a structure that can be divided into two parts and can be detached from the optical fiber.

In a specific example, the MT type connector shown in FIG. 3 is attached to the optical fiber core wire shown in FIG. 8 (A), and an overhead conduit having the structure shown in FIG. 7 (B) is used. It was sent to an overhead conduit cable with a length of 140 m installed at 5 m. The guide tube used had an inner diameter of 12 mm. The diameter of the joint between the guide pipe with a diameter larger than that of the connector and the overhead pipe with a diameter smaller than that of the connector is tapered, so when the connector is pulled up, the diagonal of the connector When the length is smaller than the length, the connector is caught and stops. Then, by removing the guide conduit and dividing the joint, the connector is pulled up to a predetermined position slightly apart from the end of the aerial conduit, and the connector can be easily connected.

FIG. 5 is an explanatory view of another embodiment of the guide conduit. In the figure, the same parts as those in FIG. Reference numeral 22 is a guide conduit, 23 and 24 are joints, and 25 is a barrier. As shown in FIG. 5 (A), at the tip of the guide conduit 10 in the above-described embodiment, the joint portion 23 is formed.
The guide line 22 having a predetermined length L was attached by, and the tip thereof was attached to the aerial line 1 by the joint portion 24. Joint 2
Although both 3 and 24 have a structure in which they are split into two, a fluid resistance to the air flow is small in the joint portion 23, and a space through which the optical fiber core wire can pass is formed so that the connector cannot pass through. A barrier 25 is provided. An example of the shape of the barrier is shown in FIG.

When the connector is fed through this guide pipe, the pulled-up connector stops at the barrier 25. After stopping the air flow, the joints 23 and 24 are removed in two and the guide conduits 10 and 22 are removed.
As shown in (C), the connector can be pulled up in a state where the optical fiber core wire is pulled out by a distance L (distance from the joint portion 23 to the end of the aerial pipeline 1) from the end of the aerial pipeline 1. . The optical fiber core wire emerging from the overhead conduit 1 is
Since it is highly flexible and can be used when there is a possibility of work using the extra length of the optical fiber core wire such as changing the connection between the optical fiber core wires in the closure, in this embodiment,
It is useful because an extra length of length L can be provided in the closure.

FIG. 6 is an explanatory view of another embodiment for providing the extra length. In the figure, the same parts as those in FIG. 10a and 10b are guide lines,
Reference numerals 26 and 27 are joints, 28 is a seal member, 29 is a drive roller, 30 is a wire, and 31 is a stop plate. The guide conduit is divided into two parts, 10a and 10b, and joined at a joint portion 27. Of course, the guide pipe line may be formed of one line, or may be formed of three or more lines. The lower end of the guide conduit 10a is attached to the pressure feed head 11, and the upper end of the guide conduit 10b is connected to the aerial conduit 1 by a joint 26. The drive roller 29 is shown in FIGS.
Although the description is omitted, the optical fiber core wire is attached to the sealing member 2.
It is pushed into the pressure feeding head via 8. In this embodiment, when the connector 9 is pulled up, the wire 30 is attached to the connector 9 attached for the terminal of the source of the optical fiber core wire, and the feed amount of this wire is stopped by the stop plate 31.
The installation is continued by air flow while the pulling length is restricted. By the wire and the stop plate,
It is easy to set the extra length.

In the above-mentioned embodiment, only the case of laying one optical fiber core wire has been described. However, in the case of laying a plurality of optical fiber core wires at the same time, or additionally, the optical fibers are added. It goes without saying that the present invention can be applied to the case of laying the core wire.

[0042]

As is apparent from the above description, according to the present invention, the overhead work can be reduced as much as possible to define the extra length of the optical fiber core in the closure, so that the optical fiber core can be installed easily. Therefore, it is useful when used for aerial wiring of an optical subscriber system.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a concept of a final state in a laying method according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an example of equipment placed on the ground.

FIG. 3 is a perspective view of an optical fiber core wire and an MT type connector.

FIG. 4 is an explanatory diagram of an example of a guide conduit.

FIG. 5 is an explanatory view of another embodiment of the guide conduit.

FIG. 6 is an explanatory diagram of another embodiment in which a surplus length is provided.

FIG. 7 is a perspective view of an overhead pipeline that can be used in the present invention.

FIG. 8 is a cross-sectional view of various examples of optical fiber core wires that can be used in the present invention.

FIG. 9 is a schematic diagram of an example of an optical communication network.

[Explanation of symbols]

1, 2 ... Overhead conduit, 3 ... Tensile strength wire, 4 ... Utility pole, 5 ... Closure, 6, 7 ... Optical fiber core wire, 8, 9 ... Connector,
10, 10a, 10b ... Guide conduit, 11 ... Pumping head, 12 ... Air flow, 13 ... Compressor, 14 ... Dryer, 15 ... Supply reel, 16 ... Guide pin hole, 17
... optical fiber end face, 18 ... pressure feed nozzle, 19 ... blind plug, 20 ... joint part, 21 ... seal rubber, 22 ... guide conduit, 23, 24 ... joint part, 25 ... barrier, 26, 27 ... joint part, 28 ... Sealing member, 29 ... Driving roller, 30 ... Wire, 31 ... Stop plate.

Continued Front Page (72) Inventor Hiroki Ishikawa 1 Taya-cho, Sakae-ku, Yokohama-shi, Kanagawa Sumitomo Electric Industries, Ltd. Yokohama Works (72) Inventor Shigekazu Hayami 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (5)

[Claims] 1. A method of laying an aerial optical line, in which an optical fiber core wire is laid through an imaginary aerial conduit using an air flow, and the optical fiber core wire is previously attached to an end of a source side of the optical fiber core wire. A connector is installed, and a guide conduit having an inner diameter capable of transmitting the connector is joined to the end of the optical fiber core of the overhead conduit on the sender side, and the other end of the guide conduit is pulled down to the ground. , Guiding the optical fiber core wire from the ground to the aerial conduit through the guide conduit, and sending the optical fiber by an airflow flowing over the entire length of the conduit connected from a device placed on the ground, and then guiding the connector to the guide. A method for laying an aerial optical line, characterized in that the guide conduit is separated from the aerial conduit after being inserted into the conduit and pulled up to the vicinity of the end of the aerial conduit by the same air flow. 2. The method of laying an aerial optical line according to claim 1, further comprising a mechanism for stopping the communication of the connector in the vicinity of the joint between the guide conduit and the aerial conduit. 3. The aerial conduit is configured such that at least an aerial feed end includes a conduit having a small diameter whose inside diameter cannot pass through the connector, and the aerial pipe is caused to flow through the guide conduit through the connector. 3. When the connector is pulled up to near the end of the passage, the passage of the connector is stopped on the side of the guide passage of the small-diameter passage.
The method of laying the aerial optical line described in. 4. A blocking member for allowing passage of the optical fiber and the air flow and for stopping the passage of the connector is arranged near a joint between the guide pipe and the aerial pipe. The method for laying an overhead line according to claim 2. 5. The method of laying an optical overhead line according to claim 2, wherein an extension line is attached to the connector, and a pulling distance of the connector is limited by the extension line when the connector is pulled up.