JP4234670B2 - Fiber optic cable - Google Patents

Description

  The present invention relates to an optical fiber cable used as an optical drop cable, an optical indoor cable or the like for drawing and wiring from a wiring system cable to a general subscriber's house.

  In recent years, with the spread of communication services such as the Internet, FTTH (Fiber To The Home), which connects all sections from carriers to general subscriber homes with optical fibers, has been rapidly expanding. Development of various optical fiber cables necessary for construction continues.

  FIG. 6 shows an example of such an optical fiber cable, which was developed as an aerial optical drop cable for drawing and wiring into a subscriber's house from an aerial wiring system cable. As shown in the figure, this optical fiber cable has two single-core optical fiber cores 1 sandwiched between tensile strength members 2 and 2 above and below them, and a support wire 3 disposed above them. Has a structure in which a jacket 4 is provided by extrusion-coating a thermoplastic resin such as polyethylene on the outer periphery thereof. A connecting portion (neck portion) 7 that divides the cable into a supporting wire portion 5 and a cable portion 6 is provided between the supporting wire 3 and the strength member 2 of the cable. At notches 8 and 8 for tearing are provided at substantially central portions of both side surfaces.

  Further, FIG. 7 was developed as an underground optical drop cable for drawing into a subscriber's house from a wiring system cable installed underground, or a so-called optical indoor cable for indoor wiring, as shown in FIG. It is comprised similarly to the cable part 6 of an optical fiber cable.

  In such an optical fiber cable, since the strength members 2 are arranged above and below the optical fiber core wire 1, tension is generated when the cable portion 6 is separated from the support wire portion and wired, or the cable is underground or The optical fiber core wire 1 is protected from the tension at the time of laying wiring indoors, and disconnection thereof is prevented. Further, since the tensile strength member 2 is disposed, an increase in transmission loss due to a temperature change when the cable is used is also prevented. That is, if the strength member 2 is not disposed, the jacket 4 expands and contracts due to a temperature change when the cable is used, and as a result, the optical fiber core 1 may be distorted and transmission loss may increase.

  By the way, conventionally, metal wires such as steel wires have been used as the material of the strength member 2, but in recent years, in order to prevent accidents caused by lightning strikes, the materials are reinforced with non-metallic materials such as glass fibers and aramid fibers. Fiber reinforced plastics (FRP), yarns composed of tensile strength fibers such as glass fibers and aramid fibers, and yarns composed of such tensile strength fibers converged with a converging material have been generally used (for example, Patent Document 1). ~ 5).

  However, such a non-metallic material such as fiber reinforced plastic has a high tensile strength, but is relatively weak to bending, and therefore, it may break during laying wiring work. When such a fold occurs, the optical fiber may be disconnected as a result of further local bending of the cable. Further, since the tensile strength of the cable portion or the cable is reduced due to the breakage of the tensile body, the optical fiber may be broken or the cable may be broken when an excessive strain is applied.

Furthermore, recently, in this type of optical fiber cable, there has been a demand for a cable that can be easily wired and stored without taking up space in corner wiring, connection box connection, in-panel wiring, and the like. . In order to meet such demands, high-bend optical fibers have been developed in which the allowable bending radius is reduced from the conventional 30 mm to 60 mm to about 7.5 mm to 15 mm. However, as described above, since the conventional strength member is formed of a material that is not easily bent, even if a high-bend optical fiber applied to an optical fiber is used, the strength member is not bent in the cable portion or the entire cable. In order to prevent this, it has been necessary to increase the bending diameter, and it has been difficult to save space in wiring and storage.
JP 2000-171673 A JP 2002-365499 A JP 2003-98409 A JP 2003-131097 A JP 2003-207702 A

  The present invention has been made in response to the above-described problems of the prior art, and in an optical fiber cable including an optical fiber core wire, a tensile body, and a jacket for covering them all together, Occurrence of folds can be reduced, the occurrence of breaks in optical fibers and cable breaks associated therewith can be suppressed, and space saving in wiring and storage can be achieved. An object is to provide an optical fiber cable.

In order to achieve the above object, an optical fiber cable according to a first invention of the present application is arranged in parallel with a high-bend optical fiber having an allowable bending radius of 7.5 mm to 15 mm and an interval between the optical fiber. An optical fiber cable having a tensile strength member and a jacket for covering them all together, wherein the tensile strength material is a polyester fiber disposed on the outer periphery of a core material made of T glass fiber to form an alicyclic epoxy resin . It is composed of a composite material integrated with each other.

An optical fiber cable according to the second invention of the present application is a high-bend optical fiber having a permissible bending radius of 7.5 mm to 15 mm, and a tensile body arranged in parallel with a distance from the optical fiber. An optical fiber cable having a cable portion having a jacket for covering them all together and a support wire portion having a support wire for supporting the cable portion, wherein the tensile body is made of T glass fiber. It is comprised by the composite material which has arrange | positioned the polyester fiber to the outer periphery of this, and was integrated with the alicyclic epoxy resin .

  According to the optical fiber cable of the present invention, since the bending characteristics of the tensile strength body are improved, the occurrence of breakage of the tensile strength body at the time of laying wiring work can be reduced. And the like, and space saving in wiring and storage can be achieved.

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

  FIG. 1 is a cross-sectional view showing a first embodiment of the optical fiber cable of the present invention.

  As shown in FIG. 1, the optical fiber cable 10 of the present embodiment includes two single-core optical fibers 11 arranged in parallel in the vertical direction, and above and below these single-core optical fibers 11. The first strength member 12a and the second strength member 12b, which are arranged in parallel so that the centers thereof are located on substantially the same plane, are further spaced above the first strength member 12a. And a support wire 13 made of steel wires or the like arranged in parallel, and a jacket 14 made of a thermoplastic resin such as polyethylene which is extrusion-coated on the outside. Between the first strength member 12a of the outer sheath 14 and the support wire 13, the cable 10, the support wire portion 15 including the support wire 13, the single-core optical fiber core wire 11, and the first and second tensile strengths are provided. A neck portion 17 is provided to divide the cable portion 16 including the bodies 12 a and 12 b and to easily separate the support wire portion 15 from the cable portion 16. In addition, tearing notches 18 are provided on both sides of the single-core optical fiber core 11 of the jacket 14 so that the single-core optical fiber core 11 can be easily taken out during cable terminal processing or the like.

  In the present embodiment, the first and second strength members 12a and 12b are enlarged as shown in FIG. 2, and a core material 19a made of T-glass and eight polyester fibers are arranged on the outer periphery thereof. It is composed of a composite material 19b having an outer diameter of 0.4 mm integrated with a batch converging material.

  Examples of the collective converging material include alicyclic epoxy resins and vinyl ester resins having high toughness, and among them, alicyclic epoxy resins are particularly preferable because they have particularly high toughness.

  Tensile bodies 12a, 12b made of such a composite material are compared with those of the same size as compared with conventional tensile bodies made only of fiber reinforced plastics, tensile bodies made only of convergent bodies of tensile fibers, etc. On the other hand, it has good bending characteristics, while it has a tensile strength equal to or higher than that of a conventional tensile body.

  Therefore, in the optical fiber cable 10 of the present embodiment, it is possible to suppress the occurrence of optical fiber breakage and cable breakage caused by breakage of the tensile strength member during laying and wiring work. In addition, since the allowable bending radius of the entire cable portion 16 can be reduced, it can be easily wired and stored without taking up space in corner wiring, drawing into the connection box, wiring in the panel, etc. And space saving in storage. Further, in the wiring at the corner portion, wiring along the corner becomes possible, so that wiring with a good appearance is possible.

  Further, as shown in FIG. 2, the strength members 12a and 12b have irregularities on the surface, and therefore, due to the anchor effect, particularly good adhesion to the outer cover 14 is ensured without providing an adhesive layer. The manufacturing process can be simplified. That is, in order for the strength member disposed in the cable portion 16 to suppress the expansion and contraction of the jacket due to temperature changes when the cable is used and to prevent the increase in transmission loss of the optical fiber associated therewith, Good adhesion to the substrate must be maintained, and conventionally, an adhesive layer is generally provided on the surface of the strength member. In the optical fiber cable 10 of this embodiment, since the unevenness | corrugation is formed in the surface of the strength bodies 12a and 12b, the process of providing such an adhesive layer can be skipped.

  The single-core optical fiber core wire 11 used in the present embodiment is not particularly limited, and the outer periphery of the optical fiber is coated with an ultraviolet curable resin, and the outer periphery thereof is coated with a polyamide resin or a thermoplastic elastomer. Coated material is used, but in order to save space in wiring and storage, a highly bent optical fiber core using an optical fiber with an allowable bending radius of 7.5 mm to 15 mm should be used. Is preferred.

  In addition to polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-propylene copolymer, and the like are used as a material constituting the outer cover 14. These resins may contain a flame retardant, a colorant, and the like.

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

  FIG. 3 is a cross-sectional view according to the second embodiment of the present invention, and parts common to FIG.

  The optical fiber cable 20 according to the present embodiment is used as a so-called underground drop cable wired underground, or an optical indoor cable for wiring indoors after being pulled in by an underground or aerial optical drop cable. The configuration is the same as that of the first embodiment shown in FIG. 1 except that the support line portion 15 and the neck portion 17 are not provided.

  That is, the first tensile body 12a and the second tensile body 12b are arranged in parallel with an interval between the two single-core optical fiber cores 11 arranged in parallel in the vertical direction. Is provided with a jacket 14 made of a thermoplastic resin such as polyethylene. In addition, a tear notch 18 is provided in the center of both sides of the jacket 14 at the portion where the two single-core optical fibers 11 are located. Then, the first and second strength members 12a and 12b are made of a core material 19a made of T-glass and an outer diameter of 0.4 mm in which eight polyester fibers are arranged on the outer periphery and integrated by a batch converging material. It is comprised with the composite material 19b which becomes.

  Also in the optical fiber cable 20 configured in this way, as in the case of the first embodiment, the strength characteristics of the strength members 12a and 12b are better than the conventional one. It is possible to suppress the occurrence of optical fiber breakage and cable breakage accidents caused by bending. In addition, since the allowable bending radius of the entire cable can be reduced, it can be easily routed and stored without taking up space in corner wiring, drawing into the junction box, wiring in the panel, etc. The space can be saved. Further, in the wiring at the corner portion, wiring along the corner becomes possible, so that wiring with a good appearance is possible. In addition, since the unevenness is formed on the surfaces of the tensile strength members 12a and 12b, the anchor effect can ensure good adhesion to the outer cover 14 without providing an adhesive layer. The step of providing can be omitted.

  In the above embodiments, the number of single-core optical fibers 11 is not particularly limited to two, and may be one or three or more.

  Further, as illustrated in FIG. 4, one or a plurality of optical fiber ribbons 111 may be used instead of the single optical fiber core 11. In the optical fiber cable 30 shown in FIG. 4, in the embodiment shown in FIG. 1, a plurality of (four in the example of the drawing) optical fiber strands are arranged in parallel instead of the two single-core optical fibers 11. A single optical fiber ribbon 111 having a single outer coating is disposed on the outer periphery thereof.

  Further, in the examples described above, two strength members, two single-core optical fiber core wire 11 or optical fiber tape core wire 111, are arranged in parallel with a space above and below them. You may make it arrange | position only to either one of the upper and lower sides of the optical fiber core wire 11 or the optical fiber tape core wire 111. FIG. The optical fiber cable 40 shown in FIG. 5 is an example thereof, and in the first embodiment, only the tensile body 12b positioned on the opposite side of the support line 13 is disposed.

  Next, although the Example of this invention is described concretely, this invention is not limited to the following Examples at all.

Example 1
An optical drop cable having the structure shown in FIG. 1 was manufactured.
The single-core optical fiber core 11 is a highly bent single-core optical fiber core wire (allowable bending radius 7.5 mm) having an outer diameter of 250 μm, and the support wire 14 is a galvanized single steel wire having an outer diameter of 1.2 mm. Was used. The first and second strength members 12a and 12b are composite materials having an outer diameter of 0.4 mm in which eight 50 denier polyester fibers are arranged on the outer periphery of a core material made of T-glass and are collectively converged by a vinyl ester resin. (For example, A-type tension member manufactured by NITTOBO FRP Co., Ltd.) was used.

  These two single-core optical fibers 15, two strength members 12 a and 12 b, and a support wire 13 are introduced into the extruder in a state of being arranged in parallel as shown in FIG. Non-halogen flame-retardant polyethylene was coated by extrusion extrusion to produce an optical fiber cable having an overall width of about 2 mm and a height of about 5 mm.

Example 2
A composite material having an outer diameter of 0.4 mm, in which eight 50-denier polyester fibers are arranged on the outer periphery of a core material made of T-glass on the first and second strength members 12a and 12b and converged together by an alicyclic epoxy resin ( For example, an optical fiber having a total width of about 2 mm and a height of about 5 mm is the same as in Example 1 except that a B-type tension member manufactured by NITTOBO FRP Corporation is used. A cable was manufactured.

  The tensile strength member 12a when the cable portion 16 obtained by cutting the support wire portion 15 from the optical fiber cable obtained in each of the above embodiments is bent in the direction in which the notch 18 is formed around the single-core optical fiber core wire 15. The minimum bending radius at which 12b does not break was measured, and its bending resistance was evaluated. The results are shown in Table 1.

In Table 1, for the purpose of comparison with the present invention, the first and second strength members 12a and 12b are made of fiber reinforced fibers having an outer diameter of 0.4 mm made of E glass used for a general optical fiber cable. An optical fiber cable (Comparative Example 1) having a total width of about 2 mm and a height of about 5 mm, manufactured in the same manner as in Example 1, except that a plastic (G-FRP) strength member was used. The second tensile strength members 12a and 12b were manufactured in the same manner as in Example 1 except that a tensile strength member of fiber reinforced plastic (Kevlar-FRP) made of aramid fibers (Kevlar) and having an outer diameter of 0.4 mm was used. The results of the same characteristic evaluation for the optical fiber cable (Comparative Example 2) having an overall width of about 2 mm and a height of about 5 mm are also shown.

It is sectional drawing which shows the optical fiber cable which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the strength body used in 1st Embodiment. It is sectional drawing which shows 2nd Embodiment of the optical fiber cable of this invention. It is sectional drawing which shows the modification of this invention. It is sectional drawing which shows the other modification of this invention. It is sectional drawing which shows an example of the conventional optical fiber cable. It is sectional drawing which shows the other example of the conventional optical fiber cable.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 20, 30, 40 ... Optical fiber cable, 11 ... Single-core optical fiber core wire, 12a, 12b ... 1st and 2nd strength body, 13 ... Support wire, 14 ... Outer jacket, 15 ... Support wire part, 16 ... Cable part, 19a ... Core material, 19b ... Composite material, 111 ... Optical fiber tape core wire

Claims (2)

An optical fiber comprising a high-bend optical fiber having an allowable bending radius of 7.5 mm to 15 mm, a tensile body arranged in parallel with the optical fiber being spaced apart from each other, and a jacket covering them all together A cable,
An optical fiber cable characterized in that the tensile body is composed of a composite material in which polyester fibers are arranged on the outer periphery of a core material made of T glass fibers and integrated with an alicyclic epoxy resin . A high-bend optical fiber having a permissible bending radius of 7.5 mm to 15 mm, a tensile body disposed in parallel with the optical fiber being spaced apart from each other, and a cable portion having a jacket covering them all together An optical fiber cable having a support line portion provided with a support line for supporting the cable portion,
An optical fiber cable characterized in that the tensile body is composed of a composite material in which polyester fibers are arranged on the outer periphery of a core material made of T glass fibers and integrated with an alicyclic epoxy resin .

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