JP2011232374A - Multicore optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multicore optical fiber cable to which an effective water stop property can be imparted without any change in outer diameter of the cable.SOLUTION: A multicore optical fiber cable 10 is obtained by collecting and twisting a plurality of optical fiber units 11 made from a plurality of single-core optical fiber ribbons 23-26. The outer circumference of the optical fiber units 11 is integrated with a water-absorbing yarn 27.

Description

  The present invention relates to a multi-core optical fiber cable in which a large number of single-core optical fibers or optical fiber ribbons are assembled.

  As an example of a conventional multi-core optical fiber cable, the multi-core optical fiber cable 200 shown in FIG. 5 is obtained by straightening or twisting four single-core coated optical fibers 201 and winding an identification yarn 202 and integrating them. The spacer 203 having the tension member 204 at the center is assembled in the spacer groove 205, the press-wound tape 206 is wound around the outer periphery thereof, and the outer cover 207 is formed around the outer periphery (see, for example, Patent Document 1).

  As a method for imparting water-stopping properties to such a multi-core optical fiber cable 200, there is a method in which a water-absorbing tape (water-absorbing powder is attached to the inner surface) is used for holding and winding.

JP-A-11-6943

  Multi-fiber optical fiber cables are generally thinner and lighter, and are more excellent in laying workability and handling. However, since the water-absorbing tape has a thickness of about 0.2 to 0.6 mm, the cable outer diameter becomes thicker by about 0.5 to 1.5 mm, and the cable weight becomes heavier accordingly. was there.

  An object of the present invention is to solve the above-described problems, and to provide a multi-core optical fiber cable that can have an effective water stop characteristic without changing the cable outer diameter. is there.

  A multi-core optical fiber cable according to the present invention capable of solving the above-mentioned problems is a multi-core optical fiber cable in which a plurality of units each composed of a plurality of single-core optical fiber cores or optical fiber tape core wires are assembled together. In addition, the unit is characterized by being bundled with water-absorbing yarn.

  According to the multi-core optical fiber cable configured in this way, the unit is bundled with water-absorbing yarns so that it can be stored per unit of cable length compared to when water-absorbing yarns are vertically attached. The length of the absorbed water yarn can be increased. Further, since the water absorbing yarn is not parallel to the running direction, the water absorbing yarn becomes a physical obstacle to the running water, and the water stopping performance can be greatly improved. Moreover, since the unit is bundled with the water absorbing yarn, the unit is uniformly contacted with the plurality of optical fiber core wires, so that the entire unit can have uniform and stable water stop performance.

  Moreover, in the multi-core optical fiber cable according to the present invention, it is preferable that the core wires inside the unit or the small core wires constituting the core wire group are gathered by being twisted in the longitudinal direction.

  According to the multi-core optical fiber cable configured as described above, even if there is an optical fiber core wire that is not in contact with the water-absorbing yarn in one cross section by twisting the core wire group in the longitudinal direction, In another cross section, the probability of contact with the water-absorbing yarn is increased, and the water stop performance can be enhanced.

  Further, in the multi-fiber cable according to the present invention, one or a plurality of the units are arranged in the spacer groove of the spacer having the tension member at the center, and the pressing unit is thinner than the water absorbing yarn on the outer periphery thereof. It is preferable that a winding tape is wound and a jacket made of a thermoplastic resin is applied to the outer periphery.

  According to the multi-core optical fiber cable configured in this way, water absorption yarns can be arranged uniformly in the entire core group for each unit without increasing the outer diameter, so that the entire cable is stable. The water stop performance can be given.

  Moreover, in the multi-core optical fiber cable according to the present invention, it is preferable that the constituent material of the water absorbing yarn is colored in various colors with a dye or the like.

  According to the multi-core optical fiber cable configured as described above, the water-absorbing yarn can also serve as a colored identification yarn that binds each unit by coloring the water-absorbing yarn in various colors. Thereby, the enlargement of the unit outer diameter due to the unit periphery being bundled with the water absorbing yarn can be prevented.

According to the multi-core optical fiber cable according to the present invention, the unit is bundled with water-absorbing yarn around the unit, so that the water-absorbing yarn is stored vertically per unit length as compared with the case where the water-absorbing yarn is vertically attached. The length of the water absorbing yarn will increase.
In addition, by uniting the unit with water-absorbing yarn, the water-absorbing yarn becomes a physical obstacle for running water and dramatically improves water stopping performance, and evenly contacts with multiple optical fiber core wires, The entire unit can have an even and stable water stop performance.

It is an external appearance perspective view of the optical fiber unit applied to the multi-core optical fiber cable which concerns on one Embodiment of this invention. It is sectional drawing explaining the contact state of the water absorption yarn shown in FIG. 1, and an optical fiber unit. It is another sectional view in the longitudinal direction for explaining the contact state between the water absorbing yarn shown in FIG. 1 and the optical fiber unit. It is sectional drawing of the multi-core optical fiber cable which concerns on one Embodiment of this invention. It is sectional drawing of the conventional multi-core optical fiber cable.

  Hereinafter, a multi-core optical fiber cable according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a multi-core optical fiber cable composed of a plurality of single-core optical fibers is described as an example, but a multi-core optical fiber cable composed of a plurality of optical fiber ribbons has the same function and effect. Have

  A multi-core optical fiber cable 10 according to an embodiment of the present invention includes an optical fiber unit 11 to be described later disposed in a spacer groove 4 of a spacer 2 having a tension member 3 at the center, and then pressed and wound on the outer periphery thereof. A tape 5 is wound, and a jacket 6 made of a thermoplastic resin is provided on the outer periphery. (See FIG. 4).

As shown in FIG. 1, the optical fiber unit 11 includes three bundles of a first core group 19 and a second core group 20 each including four single optical fiber cores 23, 24, 25, and 26. The third core wire group 21 is provided. Each of the optical fiber core wires 23 to 26 has a glass fiber 15 to 18 made of a core and a clad at the center, and the outer periphery of the glass fiber 15 to 18 is covered with a resin protective coating 22.
Each of the optical fiber cores 23 to 26 may have a colored layer having a thickness of about 1 μm to 10 μm formed on the outer periphery of the protective coating 22. Further, a thin film-like carbon layer may be coated around each of the optical fiber core wires 23 to 26.

  Each core group 19-21 is twisted in the longitudinal direction, and a single water-absorbing yarn 27 is spirally wound in the longitudinal direction of each core group 19-21. Thereby, each core wire group 19-21 is bundled by the water absorption yarn 27.

  The water-absorbing yarn 27 swells due to water absorption. For example, a water-absorbing resin such as polypropylene fiber, polyacrylate resin, polyvinyl alcohol resin, polyacrylamide resin, or polyoxyethylene resin is made into a fiber. It consists of water-absorbing fibers. The water-absorbing yarn 27 has a constituent material colored in a predetermined color with a dye or the like.

  As shown in FIG. 2, in one longitudinal section of the optical fiber unit 11, the optical fiber core wires 23 and 25 of the first core group 19 and the optical fiber core 26 of the third core group 21 are water-absorbing yarns. 27 is in contact. Therefore, the optical fiber cores 24 and 26 of the first core group 19, the optical fiber cores 23 to 26 of the second core group 20, and the optical fiber cores 23 to 25 of the third core group 21 are The water-absorbing yarn 27 is not in contact.

Further, as shown in FIG. 3, in the other cross section in the longitudinal direction of the optical fiber unit 11, since the core wire groups 19 to 21 are twisted, the optical fiber core wires 23 to 25 of the first core wire group 19. The optical fiber core wires 23 to 26 of the second core wire group 20 and the optical fiber core wires 25 and 26 of the third core wire group 21 are in contact with the water absorbing yarn 27.
Accordingly, substantially the entire circumference of each of the core groups 19 to 21 of the optical fiber unit 11 is in contact with the water absorbing yarn 27, and the water absorbing yarn 27 is in contact with each of the optical fiber core wires 23 to 26 evenly. A uniform and stable water stopping performance can be provided over the entire circumference of the fiber unit 11.

  As shown in FIG. 4, in the multi-fiber optical fiber cable 10, a water absorption yarn 27 is spirally wound around the outer periphery of each optical fiber unit 11. Thereby, the water absorption yarns 27 are uniformly arranged in the spacer groove 4.

  In such a multi-fiber optical fiber cable 10, when water such as rainwater or condensation enters the spacer groove 4 inside the cable after laying, the water flows along the longitudinal direction of the optical fiber unit 11. However, since the water absorbing yarn 27 is not parallel to the running direction and is wound so as to be a physical obstacle to the running water, the water absorbing yarn 27 absorbs the running water. The water absorption yarn 27 is swollen by this water absorption, and water is prevented from adhering to each of the optical fiber core wires 23 to 25. Thereby, it is possible to prevent water from adversely affecting the optical characteristics of the optical fiber cores 23 to 25.

  As described above, the multi-core optical fiber cable 10 of the present embodiment is a multi-core optical fiber cable in which a plurality of optical fiber units 11 composed of a plurality of single-core optical fibers 23 to 26 are gathered together. Then, the periphery of the optical fiber unit 11 was bundled with the water absorption yarn 27. As a result, the length of the water absorbing yarn 27 accommodated per cable unit length is increased and the water absorbing yarn 27 is not parallel to the running direction as compared with the case where the water absorbing yarn 27 is vertically attached. Becomes a physical obstacle to running water and can significantly improve the water stop performance. Moreover, since the water absorption yarn 27 bundles the optical fiber unit 11 so as to be in uniform contact with the plurality of optical fiber core wires 23 to 26, the entire unit can have an even and stable water stop performance. .

  Moreover, since each core group 19-21 in the optical fiber unit 11 is twisted and gathered in the longitudinal direction, there is an optical fiber core 23-26 that is not in contact with the water absorbing yarn 27 in a certain cross section. However, in another cross section in the longitudinal direction, the probability of contact with the water absorbing yarn 27 is increased. Thereby, the water stop performance of the multi-core optical fiber cable 10 can be improved.

  In addition, one or a plurality of optical fiber units 11 are arranged in the spacer groove 4 of the spacer 2 having the tension member 3 in the center, and then the presser winding tape 5 thinner than the water absorbing yarn 27 is wound on the outer periphery thereof. Further, a jacket 6 made of a thermoplastic resin is provided on the outer periphery. Thereby, the water absorption yarn 27 can be uniformly arranged over the entire core group 19 to 21 for each optical fiber unit 11, and the entire multi-core optical fiber cable 10 can have a stable water stop performance. .

  Further, by coloring the water absorbing yarn 27 in various colors, the water absorbing yarn 27 can also serve as a colored identification thread that binds each optical fiber unit 11. Thereby, the enlargement of the unit outer diameter due to the bundle of the water-absorbing yarns 27 around the optical fiber unit 11 can be prevented.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved. For example, an optical fiber ribbon may be applied instead of a single optical fiber.

2 Spacer 3 Tension Member 4 Spacer Groove 5 Presser Wound Tape 6 Outer Cover 10 Multi-core Optical Fiber Cable 11 Optical Fiber Unit 19 First Core Group 20 Second Core Group 21 Third Core Group 23, 24, 25, 26 Optical fiber core wire 27 Water absorption yarn

Claims (4)

A multi-core optical fiber cable in which a plurality of units consisting of a plurality of single-core optical fiber cores or optical fiber tape core wires are assembled by twisting,
A multi-core optical fiber cable in which the periphery of the unit is bundled with water absorbing yarn.   The multi-core optical fiber cable according to claim 1, wherein the core wires in the unit or the small core wires constituting the core wire group are twisted and gathered in the longitudinal direction.   The unit is arranged in a spacer groove of a spacer having a tension member in the center, and then a winding tape is wound around the outer periphery of the unit, and a jacket made of a thermoplastic resin is applied to the outer periphery. The multi-core optical fiber cable according to claim 1 or 2. The multi-core optical fiber cable according to any one of claims 1 to 3, wherein a constituent material of the water absorbing yarn is colored in various colors with a dye or the like.

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