JP2008310040A - Multi-fiber cable - Google Patents

Abstract

An object of the present invention is to remove an optical fiber bundle immediately when a unit is taken out, to easily remove an identification yarn or tape, and to have excellent unit discrimination. An object of the present invention is to provide a multi-core optical fiber cable excellent in working efficiency.
In the present invention, an optical fiber unit is formed by winding a unit identification yarn or tape around an outer periphery in which a plurality of single-core coated optical fibers are gathered straight or twisted together. A multi-fiber optical fiber cable having a structure in which a jacket 14 is provided on the outer periphery of a plurality of straight or twisted assemblies, and the winding pitch of the unit identification yarn 12 or tape is 10 mm or more and 50 mm or less. It is characterized by.
[Selection] Figure 1

Description

  The present invention relates to an optical fiber cable which is a component of information wiring using an optical fiber outdoors or indoors, and relates to a multi-core optical fiber cable in which single-core coated optical fibers coated on the outer periphery of the optical fiber are assembled. It is.

  Currently, in order to provide a wide variety of broadband services, optical fibers having the characteristics of low loss and broadband have been introduced into communication networks. When an optical fiber is used for a communication network, the optical fibers are bundled and coated to provide a multi-core optical fiber cable (see, for example, Patent Document 1).

  Recently, by increasing the amount of germanium added to the center (core) of the optical fiber to increase refraction, or adding fluorine to the outer periphery (cladding) to lower the refractive index of the outer periphery, An optical fiber for confining and guiding has been proposed (see, for example, Non-Patent Document 1). Also, a photonic crystal fiber or the like that has a number of holes near the center of an optical fiber made of glass and confines light in the center by equivalently lowering the refractive index than the center of the optical fiber. An optical fiber called a hole assist fiber has been proposed (see, for example, Non-Patent Document 2). These optical fibers can significantly suppress an increase in optical loss when the optical fiber is bent. For example, low bending loss characteristics different from those of conventional optical fibers, such as 0.2 dB / 10 turn or less at a bending radius of 15 mm. have.

  Also, as described in Patent Document 2, a multi-core optical fiber cable is proposed in which single-core coated optical fibers coated concentrically on the outer periphery of the optical fiber having low bending loss characteristics are mounted at high density. ing. In the multi-core optical fiber cable, a unit in which an identification yarn or tape is wound around the outer periphery of a collection of single-core coated optical fibers composed of several cores so that a desired single core can be taken out from the multi-fiber optical fiber. A structure in which a plurality of wires are twisted together has been proposed.

JP-A-62-204214 JP 2007-41568 A S. Matsuo et.al., “Low-bending-loss and low-splice-loss single-mode fibers containing a trench index profile”, IEICE Transactions on Electronics, Vol. E88-C, No. 5, May 2005, P889 -895 Takeshi Zhou et al. “Examination of application of photonic crystal fiber to home and building wiring” The Institute of Electronics, Information and Communication Engineers IEICE Technical Report, January 2003, p. 41-46

  However, in the conventional multi-core optical fiber cable using the identification yarn or tape, when the outer sheath of the multi-core optical fiber cable is removed and one unit including the desired optical fiber is taken out, the optical fiber bundle is There was a problem of dismantling immediately. For this reason, it becomes difficult to distinguish from the optical fiber bundles of other units, and there is a problem in that the distinctiveness is remarkably lowered.

  The present invention has been made in view of the above circumstances. When a unit is taken out, the optical fiber bundle is not immediately separated, and the identification yarn or tape can be easily removed, so that the unit can be identified. An object of the present invention is to provide a multi-core optical fiber cable excellent in performance and work efficiency.

  In order to achieve the above object, the present invention comprises an optical fiber unit formed by winding a unit identification yarn or tape around an outer periphery in which a plurality of single-core coated optical fibers are gathered straight or twisted together, and the optical fiber unit is A multi-core optical fiber cable having a structure in which a plurality of straight or twisted assemblies are provided with a jacket, wherein the winding pitch of the unit identification yarn or tape is 10 mm or more and 50 mm or less. To do.

  The present invention is also characterized in that in the multi-fiber optical fiber cable, a unit identification thread or tape is wound in a cross.

  The multi-core optical fiber cable of the present invention is characterized by a structure in which an outer jacket is provided on an outer periphery in which a plurality of the multi-fiber optical fiber cables are gathered straight or twisted around a tensile strength body.

  The present invention is also characterized in that, in the multi-core optical fiber cable, an optical fiber having an increase in optical loss of 0.2 dB / 10 turn or less is used as a single-core coated optical fiber even when bent at a radius of 15 mm. .

  The multi-core optical fiber cable according to the present invention removes the jacket of the multi-fiber cable and removes one unit including a desired optical fiber, so that the optical fiber bundle does not break immediately and other units The unit containing the desired optical fiber can be easily removed while maintaining the mutual identification with the optical fiber bundle, and at the same time, the identification yarn or tape for identifying the unit can be easily removed. The connection work using the multi-fiber optical fiber cable can be performed efficiently.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a structural cross-sectional view showing a multi-core optical fiber cable used in an embodiment of the present invention. As shown in FIG. 1, a unit-identifying yarn 12 is wound around the outer periphery of an optical fiber bundle in which a plurality of, for example, 20 single-core coated optical fibers 11 that are concentrically coated on the outer periphery of the optical fiber are densely assembled. Further, a high-density multi-core optical fiber cable is formed by applying a jacket 14 to the outer periphery in which a plurality of optical fiber units 13 are twisted together, for example, five to form a dense assembly. The A tensile strength body 15 such as a steel wire is embedded in the jacket 14 in the axial direction, and a tear string 16 capable of tearing the jacket 14 is embedded in the axial direction.

  In order to identify the optical fiber unit 13 including the desired single-core coated optical fiber 11 from the plurality of optical fiber units 13, the identification yarn 12 is colored. In addition, in order to identify the desired single-core coated optical fiber 11 from the optical fiber unit 13 including the desired single-core coated optical fiber 11, the plurality of single-core coated optical fibers 11 constituting the optical fiber unit 13 are colored. In addition, identification is possible by means such as dot printing. Further, as the single-core coated optical fiber 11, an optical fiber having a characteristic that the optical loss does not increase with respect to the bending when the optical loss increase is 0.2 dB / 10 turn or less even when bent at a radius of 15 mm may be used.

  FIG. 2 is a perspective view illustrating the configuration of the optical fiber unit according to the embodiment of the present invention. As shown in FIG. 2, the optical fiber unit 13 is formed on the outer periphery of an optical fiber bundle in which a plurality of, for example, 20 single-core coated optical fibers 11 concentrically coated on the outer periphery of the optical fiber are densely assembled. Two unit identification threads 12 are wound so as to cross at a winding pitch P of 10 mm or more and 50 mm or less.

  That is, when the identification yarn 12 is wound at a winding pitch P of 10 mm or more and 50 mm or less, the outer cover 14 is cut and removed by the tear string 16, and one optical fiber unit 13 including the desired optical fiber 11 is taken out. In addition, the optical fiber unit 13 including the desired optical fiber 11 can be easily taken out while maintaining the discriminability with the optical fiber bundles of other optical fiber units 13 without immediately disassembling the optical fiber bundle. At the same time, the identification yarn 12 for identifying the optical fiber unit 13 can be easily removed, and the performance of taking out the desired optical fiber 11 from the optical fiber unit 13 can be maintained. Connection work using a core optical fiber cable can be performed.

  Note that a unit identification tape may be used instead of the unit identification thread 12 of the above embodiment. The optical fiber unit 13 may use an optical fiber bundle in which a plurality of, for example, 20 single-core coated optical fibers 11 are twisted and densely assembled. Further, a high-density multi-core optical fiber cable may be formed by applying a jacket 14 to the outer periphery of a plurality of optical fiber units 13 that are densely gathered, for example, five straight.

  In addition, a multi-core optical fiber cable may be configured by applying a jacket to the outer periphery of a multi-core optical fiber cable configured as described above, gathered by a plurality of straight or twisted pieces around the tensile strength body. Can accommodate more single-core coated optical fibers 11.

  FIG. 3 is an explanatory diagram showing experimental results of the multi-core optical fiber cable according to the embodiment of the present invention. That is, for example, when considering connection work in an optical fiber cable, the outer cover of the optical fiber cable is usually removed with a length of about 500 mm, and therefore, an optical fiber with a length of 500 mm at various winding pitches of identification yarns. The unit was actually manufactured, and the optical fiber unit was shaken strongly ten times, and an experiment was conducted to determine whether the optical fiber unit frayed and the optical fiber bundle was broken. In the determination, if the identification yarn is not frayed at a length of 100 mm or more out of the length of 500 mm and the bundle of optical fibers is maintained, it can be easily distinguished from other optical fiber units. Is sufficiently maintained, “○” is given in that case, and “X” is given in other cases.

  Further, when connecting the identified optical fiber unit, it is necessary to remove the identification yarn. At this time, in order to work efficiently, it is necessary to have sufficient removability. Therefore, an optical fiber unit having a length of 1000 mm is actually manufactured with various winding pitches of the identification yarn, and the identification yarn is cut at the center of the optical fiber unit, and from the center to one end of the optical fiber unit. The finger was slid to test whether the identification thread could be easily removed over a length of 500 mm. In the determination, the removal experiment is performed twice in total from the center of the optical fiber unit to both ends, and the case where the removal can be performed to the end of the optical fiber unit both times is “◯”. The case where the identification yarn was entangled in the middle and could not be removed was marked with “x”.

  The single-core coated optical fiber used in the above experiment was an optical fiber core wire coated with an ultraviolet curable resin having an outer diameter of 0.25 mm, and an identification fiber was cross-wound to constitute an optical fiber unit. Further, the winding pitch P was 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 75 mm, and 100 mm.

  As can be seen from FIG. 3, when the winding pitch was 50 mm or less, the identification yarn was not frayed, and it was found that the bundle property could be maintained. Further, as for the removability of the identification yarn, when the winding pitch was 5 mm, the yarn was tangled in the middle and could not be removed. On the other hand, it was found that when the winding pitch was 10 mm or more, it had sufficient removability. For this reason, if a winding pitch of 10 mm or more and 50 mm or less is set, an optical fiber cable with high work efficiency can be realized while ensuring high unit discrimination.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

It is composition explanation sectional view showing the multi-core optical fiber cable used for the embodiment of the present invention. It is a composition explanation perspective view showing an optical fiber unit concerning an embodiment of the present invention. It is explanatory drawing which shows the experimental result of the multi-core optical fiber cable which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Single fiber covering optical fiber, 12 ... Identification thread | strain, 13 ... Optical fiber unit, 14 ... Outer jacket, 15 ... Strength body, 16 ... Rupture string

Claims (4)

  An optical fiber unit is constructed by winding unit identification yarn or tape around the outer periphery of a single fiber coated optical fiber that is assembled by straight or twisting, and the outer periphery of the optical fiber unit is assembled by straightening or twisting the optical fiber unit. A multi-core optical fiber cable having a structure with a jacket, wherein the winding pitch of the unit identification thread or tape is 10 mm or more and 50 mm or less.   2. The multi-core optical fiber cable according to claim 1, wherein the unit identification yarn or tape is wound in a cross manner.   A multi-core optical fiber cable having a structure in which an outer cover is provided on an outer periphery in which a plurality of the multi-fiber optical fiber cables according to claim 1 or 2 are gathered straight or twisted around a tensile strength body.   4. The multi-core optical fiber cable according to claim 1, wherein an optical fiber having an increase in optical loss of 0.2 dB / 10 turn or less is used as a single-core coated optical fiber even when bent at a radius of 15 mm. Multi-fiber cable.

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