JP2003050340A - Optical fiber unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a cable passing property when inserting an optical fiber unit which requires print into the pipe of a pipe composite cable for future laying. SOLUTION: A resin sheath 13 to cover the outer periphery of a coated optical fiber 12 has a bilayer structure consisting of an inner layer 14 and an outer layer 15, and printing 16 is applied to the circumferential surface of the inner layer 14, and the outer layer is formed by a transparent resin to compose the optical fiber unit 11. The optical fiber unit 11 is inserted into the pipe of the pipe composite cable for future laying in which a DV line (insulated wire) is integrated with the pipe for inserting the optical fiber unit. The insertion of the optical fiber unit 11 into the pipe does not cause the problem that friction becomes large under the effect of a printing ink layer 16, and the cable passing property is satisfactorily maintained. There is also no risk of causing print peeling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber unit which is inserted through the pipe of a pipe composite cable for optical post installation in which an insulated electric wire and a pipe for inserting the optical fiber unit are integrated.

[0002]

2. Description of the Related Art So-called FTTH (Fiber To The Home) for laying optical cables to individual consumers (general households)
When constructing an optical communication network called, an optical cable is installed alongside an overhead distribution line network. Further, in order to facilitate the handling of this FTTH, when the DV wire (vinyl-insulated electric wire for lead-in) is dropped from the utility pole to the house of the customer, as shown in FIG. 4, the DV wire 1 and the optical fiber unit are inserted. It is also practiced to pull down the DV line 1 by using a pipe composite cable 4 in which a common pipe 2 is integrated with a bind line 3, for example. As a result, when it becomes necessary to pull in the optical fiber to the customer later, that is, when optical post-laying is required, by inserting the optical fiber unit into the optical fiber unit insertion pipe 2, the demand is increased. It is possible to pull the optical fiber into the house.

FIG. 5 shows a conventional optical fiber unit 5 to be inserted into the pipe 2 of the pipe composite cable 4. As shown in the figure, the conventional optical fiber unit 5 has a structure in which the outer circumference of the optical fiber core wire 6 is covered with a single layer of resin coating 7 made of expanded polyethylene or the like.

[0004]

By the way, the optical fiber unit 5 is provided with a print (printing ink layer is shown by 8) on the outer peripheral surface thereof, for example, so that it can be distinguished from other optical fiber units. It may be given,
When printing is performed, due to the influence of the printing ink layer 8, friction when the optical fiber unit 5 is fed into the pipe 2 becomes large, and the wire passability deteriorates. Further, the print may be peeled off due to friction when the optical fiber unit 5 is passed through the pipe 2.

The present invention has been made in order to solve the above-mentioned conventional drawbacks, and has a small friction when inserting an optical fiber unit into a pipe of a pipe composite cable for optical post-laying, and has a good wire passability. An object of the present invention is to provide an optical fiber unit in which there is no fear that the printed characters printed on the optical fiber unit will be peeled off when passing the wire.

[0006]

SUMMARY OF THE INVENTION The present invention which solves the above-mentioned problems is an optical fiber which is inserted into the pipe of a pipe composite cable for optical post installation in which an insulated wire and a pipe for inserting an optical fiber unit are integrated. A unit, which has a two-layer structure of an inner layer and an outer layer with a resin coating applied to the outer periphery of the optical fiber core, and performs printing on the outer peripheral surface of the inner layer,
In addition, the outer layer is formed of a transparent resin.

A second aspect of the invention is characterized in that the outer layer of the optical fiber unit of the first aspect is made of a lubricating resin.

According to a third aspect of the present invention, in the optical fiber unit according to the first aspect, the inner layer is made of a soft resin and the outer layer is made of a hard resin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG.
~ It demonstrates with reference to FIG. FIG. 1 is a sectional view showing an optical fiber unit 11 according to an embodiment of the present invention. The optical fiber unit 11 has a two-layer structure of an inner layer 14 and an outer layer 15 for covering the outer circumference of the optical fiber core wire 12 with a resin coating 13, and prints on the outer peripheral surface of the inner layer 14 (printing ink layer is indicated by 16). ), And the outer layer 15 is made of a transparent resin. Here, the transparent resin means a resin that is transparent enough to clearly read the characters on the outer peripheral surface of the inner layer. The illustrated optical fiber core wire 12 is a single-mode, two-core tape core wire. Also, the inner layer 1
4 and the outer layer 15 are provided with V-shaped grooves for facilitating the peeling of the coating. A soft resin such as foamed polyethylene may be used for the inner layer 14 in order to protect the optical fiber core wire 12. The outer layer 15 includes a conductor and an optical fiber core wire 12.
In order to protect the above, it is preferable to use a hard and smooth surfaced lubricating resin (details will be described later). The thicknesses of the inner layer 14 and the outer layer 15 are, for example, 1.0 to 1.5 when the outer diameter of the optical fiber unit 11 is 2.5 mm.
mm, and the thickness of the outer layer 15 may be about 0.75 to 0.5 mm.

When manufacturing the above-mentioned optical fiber unit 11, first, the inner layer 14 is extruded on the outer periphery of the optical fiber core wire 12 with a resin such as foamed polyethylene. Immediately thereafter, the outer peripheral surface of the inner layer 14 is printed ( Printing ink layer 16),
The outer layer 15 is then covered with a hard, smooth and transparent resin.
Is extruded. The extrusion molding of the outer layer 15 may be performed in a line continuous with the extrusion molding of the inner layer 14 or in another line.

As the above-mentioned lubricating resin suitable as the resin for the outer layer 15, for example, silicone-dispersed polyethylene, silicone-grafted polyethylene, fluororesin-dispersed polyethylene, fluororesin or the like can be used. Silicone-dispersed polyethylene is one in which a silicone resin is uniformly dispersed in polyethylene. The silicone resin is not particularly limited, but one having an average molecular weight of 100,000 or more, preferably 300,000 to 5,000,000 is preferable, and a methyl group, a phenyl group, a chlorophenyl group, a vinyl group, a carboxyl group or the like as an organic group is preferable. Those that have are preferable. If the average molecular weight is less than 100,000, the dispersibility will be poor,
The desired slipperiness may not be obtained. Further, as the fluororesin-dispersed polyethylene, the particle size is 10 to 100 μm.
It is preferable to disperse fluororesin powder such as polytetrafluoroethylene in 1 to 10% by weight in polyethylene. Further, the outer layer 15 may be configured such that a coating layer such as polyethylene is further coated with a fluororesin or the like. Examples of such a material include, for example, a coating of low density polyethylene coated with polytetrafluoroethylene having a film thickness of several μm to several tens of μm.

The optical fiber unit 11 is a case where an optical cable is installed side by side with an overhead distribution network, and a DV line (vinyl insulated wire for lead-in) from a utility pole to a house of a customer using the pipe composite cable 4 of FIG. It is used for laying after light when 1 is drawn. That is, when it becomes necessary to pull in the optical fiber to the customer later, as shown in FIG. 2, the optical fiber unit 11 is inserted into the pipe 2 of the pipe composite cable 4 to pull in the optical fiber to the customer. To do. When the optical fiber unit 11 is inserted into the pipe 2 of the pipe composite cable 4, the optical composite insulated electric wire 4A is obtained. FIG. 3 shows a state in which post-lighting is performed. In the figure, 23 is an overhead optical cable, 24 is an optical closure, 25 is an optical branch box, 26 is a utility pole, 27 is a DV wire anchor on the utility pole 26 side, 28 is a DV wire anchor on the house 22 side, and 29 is an electric meter. , 30 are photo-termination boxes.

In the above optical post-laying work, when the optical fiber unit 11 is inserted into the pipe 2 of the pipe composite cable 4, the printing ink layer 16 is covered with the outer layer 15, so that the printing ink layer 8 causes friction. Does not occur and the passability is good. In addition, there is no fear of peeling of the print. Further, since the outer layer 15 is made of a hard and smooth resin, the friction is small and the wire passability is good in this respect as well. In addition, since the inner layer 14 that directly wraps the optical fiber core wire 12 is made of a soft resin, it is possible to prevent the optical fiber core wire 12 from being impacted, and the outer layer 15 is made of a hard resin, so that an external force is applied to the optical fiber core wire 12. Can be prevented from acting locally, and the optical fiber core wire 12 is effectively protected.

In the embodiment, the resin coating 13 surrounding the optical fiber core wire 12 has only two layers, that is, the inner layer 14 and the outer layer 15, but the provision of the intermediate layer between the inner layer and the outer layer is excluded. Absent. Further, the optical fiber core wire is not limited to the two cores of the embodiment, and may be a multi-core of three or more cores or a single core.

[0015]

According to the optical fiber unit of the present invention,
Since the resin coating applied to the outer circumference of the optical fiber core has a two-layer structure of an inner layer and an outer layer, the outer peripheral surface of the inner layer is printed, and the outer layer is formed of a transparent resin, the following effects are achieved. . (1) When the optical fiber unit is inserted into the pipe of the pipe composite cable, the printing ink layer is covered with the outer layer, so that there is no problem that friction increases due to the influence of the printing ink layer, and the wire passability is good. . (2) Since the printing ink layer is not exposed on the outer surface, there is no risk of peeling of the print. (3) When the outer layer is made of a lubricating resin as in the second aspect, the effect of reducing friction and improving the passability is further enhanced. (4) When the inner layer is made of a soft resin and the outer layer is made of a hard resin, it is possible to prevent the inner layer directly enclosing the optical fiber core from being impacted by the softness of the inner layer, and to prevent the outer layer receiving an external force. By using a hard resin, it is possible to prevent an external force from locally acting on the optical fiber core wire, and the optical fiber core wire is effectively protected.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an optical fiber unit according to an embodiment of the present invention.

2 is a cross-sectional view of an optical composite insulated wire in which the optical fiber unit of FIG. 1 is inserted in the pipe composite cable of FIG.

FIG. 3 is a diagram illustrating a state in which a DV wire (insulated electric wire) has been pulled from an overhead distribution line to a customer's house using the pipe composite cable, and then the customer has installed an optical cable afterwards. is there.

FIG. 4 is a cross-sectional view of a pipe composite cable in which a pipe into which an optical fiber unit can be inserted later is integrated with a DV line.

FIG. 5 is a cross-sectional view of a conventional optical fiber unit.

[Explanation of symbols]

1 DV wire (vinyl insulated electric wire for pulling in (insulated electric wire)) 2 Pipe (for inserting optical fiber unit) 3 bind lines 4 pipe composite cable 4A Optical composite insulated wire 11 Optical fiber unit 12 Optical fiber core 13 Resin coating 14 Inner layer 15 outer layer 21 Overhead distribution line 22 houses 23 Overhead optical cable

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazunaga Kobayashi             1440 Rokuzaki, Sakura City, Chiba Prefecture Fujikura Sa Co., Ltd.             Inside the warehouse (72) Inventor Suehiro Miyamoto             1440 Rokuzaki, Sakura City, Chiba Prefecture Fujikura Sa Co., Ltd.             Inside the warehouse F-term (reference) 2H001 BB04 BB22 DD24 FF00 FF02                       KK17 KK22                 5G313 AA01 AB03 AC12 AD03 AE01

Claims (3)

[Claims] 1. An optical fiber unit which is inserted into the pipe of a pipe composite cable for optical post-installation in which an insulated electric wire and a pipe for inserting the optical fiber unit are integrated and which is put on the outer periphery of an optical fiber core wire. An optical fiber unit comprising a resin coating having a two-layer structure of an inner layer and an outer layer, printing the outer peripheral surface of the inner layer, and forming the outer layer with a transparent resin. 2. The optical fiber unit according to claim 1, wherein the outer layer is made of a lubricating resin. 3. The optical fiber unit according to claim 1, wherein the inner layer is made of a soft resin and the outer layer is made of a hard resin.