JP2005070483A - Optical drop cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical drop cable which is has superior wiring work efficiency and ease of taking out a coated optical fiber therefrom, and enables the coated optical fiber to be connected to a computer or the like, at the terminal via a connector. <P>SOLUTION: An optical fiber cable consists of a cable body section 12 and a support wire section 11 which supports the cable body section 12. The cable body section 12 is provided with an optical fiber cord 19, in which a resin coating 18 is provided on the outer periphery of a coated optical fiber core 16 via a buffer coating 17 made of tension fibers, two tension members 20 which are arranged on both sides of the optical fiber cord 19 in parallel and an outer sheath 21 which covers the outer periphery of them altogether. The cross section of the optical drop cable is formed into a circular shape. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical drop cable used for lead-in wiring from a wiring system cable installed in an aerial or underground to a general subscriber's house.

  The concept of spreading the optical fiber communication network to the homes of subscribers such as ordinary houses and buildings is progressing concretely, and accordingly, development of various optical fiber cables necessary for the construction of such a communication network is continued.

  Of these, steel wires and FRP (glass fiber reinforced plastic) are installed on both sides of a single-core optical fiber as a so-called optical drop cable for wiring from a cable system installed in the ground or underground to a general subscriber's house. There are known tensile strength bodies consisting of materials such as those covered with a resin such as polyethylene (underground optical drop cable) or integrated with a support line along such a cable (aerial optical drop cable). (For example, refer to Patent Document 1).

  FIG. 9 shows an example of an aerial optical drop cable. As shown in this figure, this optical drop cable has single-strand optical fiber cores 1 sandwiched between them, and tensile members 2 and 2 made of FRP (glass fiber reinforced plastic) on the upper and lower sides of the optical fiber cable. The support wire 3 is arranged, and the outer periphery thereof is collectively covered with a resin such as polyethylene, and the outer cover 4 is provided. Between the support wire 3 and the strength member 2 of the cable, a neck portion (connection portion) 7 for dividing the cable into the support wire portion 5 and the cable main body portion 6 is provided. 4, tearing notches 8 and 8 are provided at the portions where the single-core optical fiber 1 is located.

  In such an optical drop cable, since the support wire 3 is provided, the aerial laying is possible, and the tensile strength member 2 is disposed with the optical fiber core wire 1 interposed therebetween. An increase in fiber transmission loss can be prevented. Further, after the cable is pulled down to the subscriber's house, the cable main body portion 8 can be separated from the support wire portion 5 and only the cable main body portion 8 can be used for indoor wiring. In addition, the support line part 5 is normally fixed to a housing wall surface. Further, since the notch 8 for tearing is provided, it is possible to easily take out the optical fiber core wire 1 by tearing the jacket 4 in the width direction of the cable at the time of cable end processing or the like.

However, in such a conventional optical drop cable, since the cross-sectional shape of the cable body 8 is rectangular or elliptical, directionality occurs in the bending direction (as indicated by the arrow in FIG. 9). It is possible to bend only in the width direction), and there is a problem that the indoor wiring work cannot be performed smoothly. In addition, since the outer diameter of the single-core optical fiber 1 is very thin (usually 250 μm), there is a problem that when the optical fiber 1 is taken out, it may be easily bent if it is bent carelessly. . For this reason, it is necessary for the operator to take out the core wire with great care, which is a heavy burden. Further, when connecting the optical fiber core wire 1 taken out from the jacket 4 to a device such as a router or a computer, it is necessary to temporarily store it in a terminal box such as a rosette. That is, the optical fiber core wire 1 must be connected by fusion or the like to an optical fiber connected to a device such as a router or a computer in the terminal box, and directly connected to these devices via a simple connector. I couldn't.
JP 2001-337255 A

  The present invention has been made in order to solve the above-described problems of the prior art, and is excellent in workability during indoor wiring, and even if careless bending is applied when the optical fiber core is taken out, the optical fiber core Another object of the present invention is to provide an optical drop cable that can be directly connected to a device such as a router or a computer by attaching a connector to the tip of the optical fiber core taken out.

  In order to achieve the above object, an optical drop cable according to claim 1 of the present application includes an optical fiber cord in which a resin coating layer is provided on the outer periphery of an optical fiber core wire through a buffer layer made of a tensile strength fiber, It comprises two strength members arranged in parallel on both sides of the optical fiber cord, and a jacket that is collectively covered on the outer periphery thereof, and is formed by forming a circular cross section. .

  The invention according to claim 2 is an optical fiber cable comprising a cable body portion and a support wire portion that supports the cable body portion, and the cable body portion is made of a tensile fiber on the outer periphery of the optical fiber core wire. An optical fiber cord provided with a resin coating layer through a buffer layer, two strength members arranged in parallel on both sides of the optical fiber cord, and a jacket that is collectively covered on the outer periphery thereof, The cross section is formed into a circular shape.

  According to a third aspect of the present invention, in the optical drop cable according to the first or second aspect, the optical fiber cord has an outer diameter of 1.0 mm to 2.0 mm.

  According to the optical drop cable of the present invention, by making the cross section of the cable or the cable main body circular, the directionality when bending is improved as compared with the conventional one, and the workability of wiring work indoors is improved. Can do. Moreover, since the optical fiber core wire can be taken out from the jacket as the optical fiber cord, it is possible to prevent the optical fiber core wire from being broken when it is taken out. Furthermore, by attaching a connector to the tip of the optical fiber cord taken out in this way, it can be directly connected to a device such as a router or a computer without being accommodated in a terminal box such as a rosette as in the past. It becomes possible.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an embodiment of the optical drop cable of the present invention.
As shown in FIG. 1, the optical drop cable 101 of this embodiment has the support wire | line part 11, the cable main-body part 12, and the connection part 13 which connects these. The support wire part 11 is comprised from the support wire 14 which consists of a steel wire etc., and the outer sheath 15 provided in the outer periphery. On the other hand, the cable body 12 includes an optical fiber cord 19 provided with a buffer layer 17 made of a tensile strength fiber around one single-core optical fiber core 16 and a resin coating layer 18 on the outer side thereof, and upper and lower sides thereof. It consists of two strength members 20 attached vertically and an outer cover 21 which is collectively covered on the outside thereof.

  Then, the outer sheath 15 of the support wire portion 11, the outer sheath 21 of the cable main body portion 12, and the connecting portion 13 are formed on the support wire portion 11 and the cable main body portion 12 by batch extrusion of a thermoplastic resin such as polyethylene or polyvinyl chloride. Each of the cross-sectional shapes is formed in a circular shape. In addition, the notches 22a and 22b for tearing are provided on the left and right surfaces of the outer cover 21 of the cable body portion 12 formed in a circular cross-section in this way. By tearing the jacket 21 starting from the tearing notches 22a and 22b, the inner optical fiber cord 19 can be easily taken out.

  The single-core optical fiber core wire 16 is not particularly limited, and the outer periphery of the optical fiber is coated with a silicone resin or an ultraviolet curable resin, and the outer periphery is further coated with a nylon resin (usually nylon) And so on).

  Further, examples of the tensile strength fiber constituting the buffer layer 17 provided around the single-core optical fiber core wire 16 include an aramid fiber such as poly-p-phenylene terephthalamide fiber and a polyester fiber such as polyethylene terephthalate fiber. Nylon fiber etc. are used. The buffer layer 17 is formed by vertically attaching such tensile strength fibers around each single-core optical fiber core wire 16.

  Further, as the resin constituting the resin coating layer 18, a thermoplastic resin such as polyethylene or polyvinyl chloride is used as in the case 21, and is formed by extrusion coating on the buffer layer 17. In addition, a coloring agent and a flame retardant may be mix | blended with these resin.

  In addition to steel wire and glass FRP, the tensile strength material 20 is made of aramid fibers such as poly-p-phenylene terephthalamide fibers, polyester fibers such as polyethylene terephthalate fibers, nylon fibers, and polyester fibers such as these. -Composite materials converged and bound with an acrylate resin or the like.

In the present invention, the buffer layer 17 and the resin coating layer 18 are connected to equipment such as a router and a computer via the connector after taking out the optical fiber cord 19 from the outer cover 21 after indoor wiring and attaching a connector to the terminal. It is desirable to set its thickness so that it can be done. However, if the thickness is too large, the outer diameter of the entire cable body 12 is increased (the outer diameter of the entire cable body 12 can be reduced if the thickness of the outer cover 21 is reduced, but the outer cover 21 Decreases in strength). From this point of view, the thicknesses of the buffer layer 17 and the resin coating layer 18 depend on the type of material constituting them, the type and number of optical fiber cores 16 to be accommodated, and the like. The layer 17 has an outer diameter in the range of about 0.75 mm to 1.40 mm, and the resin coating layer 18 has an outer diameter (the outer diameter of the optical fiber cord 19).
Provided in a range of about 1.0 mm to 2.0 mm.

  In the optical fiber cable 101 configured as described above, the cross section of the cable main body 12 is circular, so that the directionality when bending is improved as compared with the conventional one, and the indoor wiring can be smoothly advanced. . Further, since the optical fiber core wire 16 can be taken out from the outer sheath 21 as an optical fiber cord, the optical fiber core wire 16 may be broken even if careless bending or the like is applied when the optical fiber core wire 16 is taken out. Such a thing disappears. Thereby, both the operator and the burden are reduced. Furthermore, by attaching a connector such as a simple connector to the tip of the optical fiber cord 19 taken out in this way, the optical fiber cord 16 is not temporarily accommodated in a terminal box such as a rosette as in the prior art. It is possible to connect directly to a device such as a router or a computer without performing fusion or mechanical connection in the terminal box.

  2 and 3 schematically show wiring examples of the optical drop cable 101 of the present embodiment. In these figures, an optical drop cable 101 connected to a wiring system cable (not shown) in the closure is wired outdoors to the eaves of the subscriber's house 30, where the support line portion 11 is separated, and the cable body. Only the unit 12 is drawn into the subscriber home 30 and wired indoors. The support line part 11 is fixed to the wall surface of the house of the subscriber house 30. The cable body 12 wired indoors is taken out of the optical fiber cord 19 in the vicinity of the computer 31 (FIG. 2) or the router 32 (FIG. 3), and a connector is attached to the tip thereof. Connected. The router 32 is connected to the computer 31 and its peripheral devices (not shown) via another optical fiber cable 33. 2 and 3, reference numerals 35 and 36 denote fixing portions of the support wire portion 11 and the cable main body portion 12, respectively.

  In the optical fiber cable 101 of the present embodiment, by making the cross section of the cable main body portion 12 circular, the directionality when bending is improved as compared with the conventional one, and indoor wiring can be smoothly advanced. Further, since the optical fiber core wire 16 can be taken out from the outer sheath 21 as an optical fiber cord, the optical fiber core wire 16 may be broken even if careless bending or the like is applied when the optical fiber core wire 16 is taken out. Such a thing disappears. Thereby, both the operator and the burden are reduced. Furthermore, by attaching a connector such as a simple connector to the tip of the optical fiber cord 19 taken out in this way, the optical fiber cord 16 is not temporarily accommodated in a terminal box such as a rosette as in the prior art. It is possible to connect directly to a device such as a router or a computer without performing fusion or mechanical connection in the terminal box.

  Next, another embodiment of the present invention will be described.

  FIG. 4 is a cross-sectional view according to the second embodiment of the present invention, and parts common to FIG.

  The optical fiber cable 102 according to the present embodiment is generally used as a so-called underground drop cable wired underground, and does not have the support line portion 11 and the connecting portion 13. The configuration is the same as that of the first embodiment.

  That is, a buffer layer 17 made of a tensile strength fiber is provided around one single-core optical fiber core wire 16, and two strength members 20 are vertically arranged above and below an optical fiber cord 19 provided with a resin coating layer 18 on the outer side thereof. At the same time, the outer cover 21 is collectively covered on the outside. The outer casing 21 has a circular cross-sectional shape, and tearing notches 22 a and 22 b are provided on the left and right surfaces of the outer casing 21.

  Also in the optical fiber cable 102 configured in this way, as in the case of the first embodiment, by making the cross section of the cable main body 12 circular, the directionality when bending is improved compared to the conventional one. , Indoor wiring can proceed smoothly. Further, since the optical fiber core wire 16 can be taken out from the outer sheath 21 as an optical fiber cord, the optical fiber core wire 16 may be broken even if careless bending or the like is applied when the optical fiber core wire 16 is taken out. Such a thing disappears. Thereby, both the operator and the burden are reduced. Furthermore, by attaching a connector such as a simple connector to the tip of the optical fiber cord 19 taken out in this way, the optical fiber cord 16 is not temporarily accommodated in a terminal box such as a rosette as in the prior art. It is possible to connect directly to a device such as a router or a computer without performing fusion or mechanical connection in the terminal box.

  In the present invention, for example, as shown in FIGS. 5 and 6, the number of single-core optical fibers 16 may be two or more. An optical fiber cable 103 shown in FIG. 5 is obtained by arranging two single-core optical fibers 16 in the first embodiment, and the optical fiber cable 104 shown in FIG. 5 is the same as that of the first embodiment. In FIG. 3, three single-core optical fiber core wires 16 are arranged.

  For example, as shown in FIGS. 7 and 8, one or a plurality of optical fiber ribbons 161 and 162 may be used instead of the single-fiber ribbon 16. The optical fiber cable 105 shown in FIG. 7 has two optical fiber strands arranged in parallel instead of the two single optical fiber core wires 16 in the first embodiment, and the outer periphery thereof is collectively covered. One optical fiber cable core 161 is disposed, and the optical fiber cable 106 shown in FIG. 8 is replaced with two single optical fiber cables 16 in the first embodiment. Four optical fiber strands are arranged in parallel, and a single four-fiber optical fiber ribbon 162 is disposed on the outer periphery of the optical fiber.

  EXAMPLES Next, although this invention is described in an Example, this invention is not limited to a following example at all.

Example An optical drop cable having the structure shown in FIG. 1 was produced. A single-core UV curable resin-coated optical fiber core wire having an outer diameter of 250 μm is used for the single-core optical fiber core wire 16, and an FRP rod having an outer diameter of 0.4 mm is used for the tensile body 17 of the cable body 12. For No. 14, a single steel wire having an outer diameter of 1.2 mm was used.

  First, poly-p-phenylene terephthalamide fiber (Kevlar 49: Trademark) is vertically attached to the outer periphery of one single-core optical fiber core wire 16 and introduced into the first extruder. Polyethylene (trade name, Trinity FR ANA9982N, manufactured by Riken Technos Co., Ltd.) was extrusion-coated into a pipe shape having a thickness of 0.15 mm to produce an optical fiber cord 19 having an outer diameter of 1.1 mm.

  Next, the optical fiber cord 19, the two strength members 17, and the support wire 14 are introduced in parallel into the second extruder as shown in FIG. Polyethylene (trade name NUC9739 manufactured by Nippon Unicar Co., Ltd.) was collectively extrusion coated to produce an optical drop cable having a cable body portion 12 with a circular cross section having an outer diameter of about 2.5 mm and a cable height of about 5.5 mm.

  The obtained optical fiber cable was subjected to a heat cycle test (-40 ° C to + 85 ° C, 10 cycles), and the maximum increase in transmission loss was examined. It was less than 0.05 dB / km and had good temperature characteristics. It was. Moreover, when the support wire portion 11 was actually separated and indoor wiring of the cable main body portion 12 was attempted, the cable main body portion 12 could be freely bent in an arbitrary direction and could be smoothly wired. It was easy to take out the single-core optical fiber 16 at the terminal.

Sectional drawing which shows 1st Embodiment of the optical drop cable of this invention. The figure which shows typically the example of wiring of the optical drop cable of 1st Embodiment. The figure which shows typically the example of another wiring of the optical drop cable of 1st Embodiment. Sectional drawing which shows 2nd Embodiment of the optical drop cable of this invention. Sectional drawing which shows other embodiment of the optical drop cable of this invention. Sectional drawing which shows other embodiment of the optical drop cable of this invention. Sectional drawing which shows other embodiment of the optical drop cable of this invention. Sectional drawing which shows other embodiment of the optical drop cable of this invention. Sectional drawing which shows an example of the conventional optical fiber cable.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Support wire part, 12 ... Cable main-body part, 13 ... Connection part, 14 ... Support line, 15, 21 ... Outer sheath, 16 ... Single-core optical fiber core wire, 17 ... Buffer layer, 18 ... Resin coating layer, 19 ... Optical fiber cord, 20 ... Tensile body, 101 to 106 ... Optical fiber cable, 161 and 162 ... Optical fiber ribbon

Claims (3)

  An optical fiber cord in which a resin coating layer is provided on the outer periphery of the optical fiber core via a buffer layer made of a tensile strength fiber, two strength members arranged in parallel on both sides of the optical fiber cord, and an outer periphery of these optical fiber cords An optical drop cable comprising a jacket that is collectively covered and having a circular cross section. An optical fiber cable comprising a cable main body and a support wire that supports the cable main body,
The cable main body includes an optical fiber cord in which a resin coating layer is provided on the outer periphery of the optical fiber core via a buffer layer made of a tensile strength fiber, and two strength members disposed in parallel on both sides of the optical fiber cord. And an outer cover that is collectively covered on the outer periphery thereof, and has a cross-section formed into a circular shape, and is an optical drop cable.   The optical drop cable according to claim 1 or 2, wherein the optical fiber cord has an outer diameter of 1.0 mm to 2.0 mm.

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