KR20050011176A - Small-sized high-count optical fiber drop cable - Google Patents

Abstract

PURPOSE: A small-sized multi-core male optical fiber cable is provided to improve a manipulation efficiency by using an ultraviolet resin rather than a gel-type compound for coating the optical fiber cable. CONSTITUTION: A small-sized multi-core male optical fiber cable includes a cable body(1) and a support member(2). The cable body includes an optical fiber unit, an extensible line, and an outer surface surrounding the optical fiber and the extensible line. The support member includes a support line in the center thereof and an external surface surrounding the support line. The external surface of the support member is coupled with the external surface of the cable body which has the extensible line. The optical fiber unit includes a central extensible line(13), at least two optical fiber core lines, and an ultraviolet resin(14). The optical fiber core lines are condensed in a length direction by a helical twist or an SZ twist around the central extensible line. The ultraviolet resin encloses the central extensible line and the optical fiber core line.

Description

Multi-Conductor Small Entry Fiber Cable {SMALL-SIZED HIGH-COUNT OPTICAL FIBER DROP CABLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an optical fiber drop cable (FTTH) for indoor entry, and more particularly, to an optical cable for incorporation having a small outer diameter while mounting multi-core optical fibers.

Optical cables, also called fiber optic cables, are used to carry optical signals. Optical cables are classified into various types according to their structure and usage environment. An optical fiber for pulling in (hereinafter, simply referred to as a cable) is a cable which is introduced into a building such as each home or office from an optical cable installed in the air.

Fig. 1 shows a configuration example of a lead cable according to the prior art. The entry cable of FIG. 1 disclosed in Unexamined-Japanese-Patent No. 2001-337255 consists largely of the cable main body 1 and the support part 2 for supporting a cable main body. The cable main body 1 includes a sheath 3 made of polyolefin-based thermoplastic resin such as polyethylene, an optical fiber 4 of one core basically disposed at the center of the sheath 3, and an optical fiber 4 as a tension line. It consists of a copper wire 5 arranged symmetrically with respect to On the other hand, notches 6 are formed in the sheath 3 so as to easily peel off at both sides of the portion where the optical fiber 4 is disposed.

The support part 2 consists of the steel wire 7 and the coating layer 8 which coat | covered this steel wire 7 with the polyolefin thermoplastic resin, and is connected with the cable main body 1 by the bridge 9. The bridge 9 is formed to be narrow in order to facilitate the separation of the cable body 1 and the support 2. The sheath 3 of the cable main body 1 and the covering layer 8 of the support part 2 are formed of the same material, so that the sheath 3 and the covering layer 8 can be integrally formed including the bridge 9. .

However, the incoming cable shown in Fig. 1 is basically a structure that employs a single fiber and is not suitable for transmitting a large amount of information to a building such as a multi-family house or a building. Furthermore, since the optical fiber of one core extends in a straight line, it is vulnerable to stress caused by the optical fiber due to the bending of the optical cable during the laying of the optical cable or the winding of the drum.

On the other hand, U.S. Patent Application Publication No. 2003/0012529 A1 discloses an entry cable having a structure in which a transmission amount can be increased compared to the one-core structure by employing a two-core optical fiber ribbon. However, the incoming cable disclosed in this U.S. Patent Publication still has the disadvantage of being vulnerable to the above stress by extending the optical fiber in a straight line, and it is also difficult to manufacture an optical cable that accommodates more multi-core optical fibers with this structure.

FIG. 2 is a cross-sectional view of an inlet cable having a structure capable of mounting a multi-core optical fiber by applying a loose tube to the cable body 1. The cable main body 1 of the lead-in cable shown in FIG. 2 mounts the number of optical fibers 4 core wires required in the buffer tube 10 together with the jelly compound 11 for preventing water penetration, and the tube 10 In the outer circumference of the) is placed a tension member 12 for minimizing the various stresses applied to the drum winding or indoor installation of the cable, the outer structure is to surround the outer shell (8) for protecting them.

The incoming cable of FIG. 2 can accommodate a multi-core optical fiber, but due to the application of a loose tube, the outer diameter becomes large and the jelly compound is filled, so handling is poor, and it is not suitable for indoor use. In addition, unlike the inlet cable shown in Figure 1 there is no notch, and since the tension member 12 is disposed on the outer periphery of the tube 10, there is a problem that the coating stripping is not easy.

The present invention has been made in view of the above-described problems, and an object thereof is to provide an optical cable that is capable of multiplexing and has a small outer diameter and suitable for use indoors or outdoors.

In addition, an object of the present invention is to provide an optical cable that can minimize the stress applied to the bending of the optical cable.

In addition, an object of the present invention is to provide an optical cable that can be diversified and has good handleability.

The following drawings attached to the present specification are intended to assist in understanding the technical idea of the present invention together with the following detailed description of the invention, and the present invention should not be construed as being limited to only the matters shown in the following drawings.

1 is a cross-sectional view showing an example of the configuration of an optical cable for entry according to the prior art.

2 is a cross-sectional view showing another example of the configuration of the optical cable for entry according to the prior art.

Figure 3 is a cross-sectional view showing the configuration of the optical cable for entry according to a preferred embodiment of the present invention.

<Description of main reference numerals in the drawings>

1.Cable body 2.Supporting part 3.Outer shell

4 ... optical fiber 5 ... tension line 6 ... notch

7 ... Support 8 ... Outer 9 ... Bridge

13 ... central tension line 14 ... ultraviolet curable resin 15 ... fiber optic unit

In order to achieve the above object, an optical cable according to the present invention includes a cable body and a support portion connected to the cable body to support the cable body, wherein the cable body has at least two optical fiber core wires, and A tensile line disposed symmetrically on both sides, and an outer shell surrounding the optical fiber unit and the tensile line, wherein the optical fiber unit has a central tensile line disposed at its center and a helical twist or SZ twist around the central tensile line. And at least two or more optical fiber core wires arranged in a longitudinal direction, and an ultraviolet curable resin surrounding the central tensile wire and the optical fiber core wire. In addition, the support portion includes a support line disposed at the center thereof, and an outer shell surrounding the support line, wherein the outer shell of the support portion is connected to the outer shell of the cable main body on which one of the tensile lines is disposed.

According to an embodiment of the present invention, the cross section of the cable body is preferably a long rectangular or oval with the tensile line disposed, the size of the cross section of the optical cable including the support is preferably 3mm x 6mm or less.

In addition, according to an embodiment of the present invention, the outer diameter of the tube (optical fiber unit) is preferably 1.5mm or less.

In addition, the center tensile line is preferably made of fiber reinforced plastic (FRP), glass yarn (Glass Yarn), aramid yarn (Aramid Yarn), or an optical fiber.

In addition, the ultraviolet curable resin includes an acrylic resin, a urethane resin, or a resin mixed with them.

Moreover, it is preferable that the notch is formed in the outer part of the said cable main body in the part in which the said optical fiber unit is arrange | positioned so that peeling may be easy.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the terms used in the present specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to explain their invention in the best way. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention on the basis of the principle of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one of the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

3 is a cross-sectional view showing the configuration of a lead cable according to a preferred embodiment of the present invention.

Referring to FIG. 3, the incoming cable according to the present embodiment includes a cable main body 1 and a support 2 extending parallel to the cable main body 1 and supporting the cable main body. The cable main body 1 includes an optical fiber unit 15 and a tensile line 5 symmetrically arranged on both sides (up and down in the figure) of the optical fiber unit 15, and the optical fiber unit 15 and the tensile line 5 ) Is wrapped by the sheath 3.

The optical fiber unit 15 twists and gathers as many colored optical fiber 4 core wires as necessary around the central tensile line 13 in an SZ method or a helical manner, and coats them using an ultraviolet curable resin 14. Has a structure. The number of optical fibers 4 is not particularly limited here, but about 2 to 12 cores are suitable so that the outer diameter of the entire cable is not too large. In this case, according to the embodiment of the present invention, the outer diameter of the optical fiber unit can be made 1.5 mm or less.

The center tensile line 13 is to minimize the stress applied to the optical fiber unit 15, and may be made of FRP, glass yarn, aramid yarn or optical fiber. Thus, since the optical fiber 4 core wire is twisted and gathered around the center tensile line 13, the bending characteristic of an optical cable can be improved compared with the conventional structure in which an optical fiber extends linearly.

As the ultraviolet curable resin 14, an acrylic resin, a urethane resin, or a mixed resin thereof may be used, and the resin is cured by irradiating ultraviolet rays after coating the resin. These resins can be easily detached by hand, and the handleability is remarkably improved because no conventional jelly compound is used.

The tension line 5 is used to prevent an increase in transmission loss due to deformation of the outer skin 3 due to the use environment temperature of the optical cable and deformation of the optical fiber 4, such as FRP, glass yarn, aramid yarn, and the like. Made of nonmetallic material. On the other hand, at least one of the tension line 5 may be made of a conductive metal such as copper, aluminum, in this case, the tension line 5 may serve as a feeder for supplying power.

The outer shell 3 may be polyethylene (PE), polyvinyl chloride (PVC), or the like, as a flame retardant plastic. On the other hand, the notch 6 is formed in the outer part 3 in the part in which the optical fiber unit 15 is arrange | positioned, and the outer skin can be easily peeled off by hand.

The support part 2 consists of the support line 7 and the outer shell 8 which surrounds this support line 7, and the cable main body 1 and any tension line 5 are arrange | positioned by the bridge 9 It is connected to one side. The bridge 9 is formed to be narrow in order to facilitate the separation of the cable body 1 and the support 2.

On the other hand, the outer shell 3 of the cable main body 1 and the outer shell 9 of the support part 2 are formed of the same material, so that the outer shell 3 and the support part 2 of the cable main body 1 including the bridge 9 are formed. The outer shell 9 of) can be integrally formed.

On the other hand, the drawn cable of the embodiment described above was actually created and its size and performance were tested, and the result is described.

First, an optical fiber was used as the center tensile wire, and 6 cores of colored optical fiber cores (0.20 mm to 0.26 mm in diameter) were twisted in SZ to form a core, and the acrylic and urethane UV curable resins were coated thereon. And then cured to form an optical fiber unit. At this time, the outer diameter of the optical fiber unit was able to produce less than 1.2mm.

The tensile line was positioned symmetrically up and down of the optical fiber unit using an FRP of 0.4 mm in diameter. In addition, the support wire was manufactured using a steel wire with a diameter of 1.2mm, and black PE, a flame retardant, was used as the cable jacket.

Tensile testing of the finished cable (IEC 60794-1-2 Method E1) revealed that the product had more than the tensile strength required, with no change in loss even at tensions of 1200 N or more. On the other hand, in the optical loss measurement, good results were found to be 0.25 dB or less for light at 1550 nm wavelength and 0.36 dB or less for light at 1310 nm wavelength.

In addition, the cross-sectional size of the optical cable including the support is 3mm x 6mm or less, despite the multiplicity, it was possible to manufacture a very small cable. Therefore, it is suitable for drawing into a building.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

According to the present invention, the optical fiber structure for the inlet can accommodate a multi-core optical fiber, and furthermore, it can be miniaturized and lightweight despite the multi-core, and solves the problems of use indoors and the problem of stripping the coating.

In addition, according to the optical cable for pulling in the present invention, the handling properties are remarkably improved by using an ultraviolet curable resin without using a jelly compound.

In addition, according to the present invention, since the optical fiber unit is manufactured by twisting the optical fiber core wire in the SZ or helical manner, the stress received when the cable is bent can be minimized.

Claims (12)

A cable body including an optical fiber unit having at least two optical fiber core wires, a tensile wire symmetrically disposed on both sides of the optical fiber unit, and an outer shell surrounding the optical fiber unit and the tensile wire; And And a support including a support line disposed at the center thereof and an envelope surrounding the support line. The outer shell of the support portion is connected to the outer shell of the cable body on which one of the tension lines is disposed, The optical fiber unit includes a central tensile line disposed at the center thereof, the at least two optical fiber cores longitudinally assembled by helical twist or SZ twist around the central tensile wire, and ultraviolet rays surrounding the central tensile wire and the optical fiber core wire. Optical cable containing hardening resin. The optical cable according to claim 1, wherein the cross section of the cable main body has a long rectangular or oval shape in which the tension line is disposed, and the size of the cross section including the support portion is 3 mm x 6 mm or less. The optical cable according to claim 1, wherein an outer diameter of the optical fiber unit is 1.5 mm or less. The optical cable according to claim 1, wherein the at least two optical fiber core wires are colored in different colors. The optical cable according to claim 1, wherein the center tensile line is made of fiber-reinforced plastic, glass yarn, aramid yarn, or optical fiber. The optical cable according to claim 1, wherein the ultraviolet curable resin is an acrylic resin, a urethane resin, or a mixed resin thereof. The optical cable of claim 1, wherein the tensile line is made of a nonmetallic material. The optical cable according to claim 1, wherein at least one of the tension lines is made of a conductive metal. The optical cable according to claim 1, wherein the support line is made of steel wire, plastic coated steel wire, or fiber reinforced plastic. The optical cable according to claim 1, wherein a notch is formed in a portion of the cable main body in which the optical fiber unit is disposed. The optical cable of claim 1, wherein the outer shell of the cable body and the outer shell of the support part are integrally formed of the same material. The optical cable according to claim 1 or 11, wherein the outer shell of the cable body and / or the outer shell of the support portion are made of flame retardant plastic.