JP2014021251A - Optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber cable in which the number of components used can be decreased and reduction in size and reduction in cost can be achieved.SOLUTION: An optical fiber unit 10 includes a plurality of coated optical fibers 11a to 11g and a coated optical fiber 12 for bundling, which bundles the plurality of coated optical fibers 11a to 11g. The coated optical fiber 12 for bundling is used not only as a coated optical fiber for optical transmission but as a bundling material to bundle the coated optical fibers 11a to 11g. The optical fiber unit 10 thus configured is stored in an optical fiber cable.

Description

  The present invention relates to an optical fiber cable in which an optical fiber unit composed of a plurality of optical fiber cores is housed.

  Conventionally, in an optical fiber cable, optical fiber core wires are bundled with a bundle material every 4 cores or every 8 cores in order to ensure the discriminability and take-out property, and this is stored as one unit in the optical fiber cable. There is something. At this time, a thread-like or tape-like material (cotton yarn, polyethylene terephthalate (PET) yarn or the like) is usually used for the bundle material.

  For example, in Patent Document 1 below, a multi-core optical fiber cable having a structure in which a plurality of optical fiber units are gathered and a jacket is provided on the outer periphery, and the winding pitch of the unit identification thread or tape is set to a predetermined pitch What has been made to be disclosed is disclosed.

  Further, in Patent Document 2 below, a unit configured by winding an identification yarn around the outer periphery of an optical fiber bundle in which a plurality of single-core coated optical fibers are assembled is formed. A multi-core optical fiber cable having a presser wound layer composed of a thin sheet of protective tape and further having a polyethylene jacket on its outer periphery is disclosed.

JP 2008-31040 A JP 2010-008923 A

  However, the multi-core optical fiber cables disclosed in Patent Documents 1 and 2 use a bundle material such as a thread or a tape to bundle the optical fibers. Therefore, as the number of optical fiber units inserted into the optical fiber cable increases, the amount of the bundle material increases, which may cause a problem in the space and cost in which the bundle material is disposed.

  In view of the above, an object of the present invention is to provide an optical fiber cable capable of reducing the number of members to be used, realizing downsizing and cost reduction.

  In order to solve the above problems, an optical fiber cable according to the present invention is an optical fiber cable in which an optical fiber unit configured by bundling a plurality of optical fiber cores is housed, and the plurality of optical fibers An optical fiber core wire is used as a bundle material for bundling the core wires.

  Moreover, it is preferable that the diameter of the optical fiber core wire used as the said bundle material is 200-500 micrometers in the optical fiber cable of this invention.

  In the optical fiber cable of the present invention, it is preferable that a winding pitch of the optical fiber core wire used as the bundle material is 50 to 500 mm.

  In the optical fiber cable of the present invention, it is preferable that the number of optical fiber cores used as the bundle material is plural.

  In the optical fiber cable of the present invention, it is preferable that the diameter of the optical fiber core used as the bundle material is different from the diameter of the bundled optical fibers.

  In the optical fiber cable of the present invention, it is preferable that the diameter of the optical fiber core used as the bundle material is larger than the diameter of the bundled optical fibers.

  In the optical fiber cable of the present invention, it is preferable that the color of the optical fiber cores used as the bundle material is different from the color of the bundled optical fiber cores.

  In the optical fiber cable of the present invention, it is preferable that a plurality of the optical fiber units are accommodated, and the color of the optical fiber used as the bundle material is different for each optical fiber unit.

  According to the optical fiber cable of the present invention, since the optical fiber core wire is used as a bundle material for bundling the optical fiber core wires, the bundle material can be used for communication in the same manner as other optical fiber core wires. . Therefore, the number of members used can be reduced as compared with the case of using a bundle material that is not an optical fiber core wire, and the outer diameter of the cable can be reduced or the cost of the cable can be reduced. In addition, it is possible to realize a multi-fiber and high-density optical fiber cable.

It is sectional drawing which shows one Embodiment of the optical fiber cable which concerns on this invention. It is a perspective view which shows the optical fiber unit accommodated in the optical fiber cable which concerns on this invention. It is a perspective view which shows one form of the optical fiber core wire which comprises the optical fiber unit. It is a perspective view which shows the modification 1 of an optical fiber unit. It is a perspective view which shows the modification 2 of an optical fiber unit.

  Embodiments of an optical fiber cable according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of an optical fiber cable. As shown in FIG. 1, the optical fiber cable 1 includes a plurality (five in this example) of optical fiber units 10 in which a plurality of optical fiber cores 11 are bundled.

  The optical fiber cable 1 includes a tension member 2, a slot rod 3, an absorbent material 6, a jacket 7, a jacket tear string 8, and an optical fiber unit 10 (10A to 10E).

  The tension member 2 is a reinforcing member against tension or bending applied to the optical fiber cable 1 at the time of laying or after laying, and is made of, for example, steel wire, fiber reinforced plastic (FRP) or the like.

  The slot rod 3 is a rod in which slot grooves 5 (5A to 5E) in which the optical fiber unit 10 is accommodated are formed on the outer peripheral surface 4, and is made of polyethylene (PE) resin or the like. The slot rod 3 is manufactured by extruding polyethylene or the like around the tension member 2.

  Although not shown, as the optical fiber cable 1, a type of cable called an SZ slot cable is used. This is a cable in which the spiral direction of the slot groove 5 formed on the outer peripheral surface 4 of the slot rod 3 is reversed at a constant period. However, the present invention is not limited to this, and for example, an S-type or Z-type slot rod in which the slot groove 5 is formed in one spiral direction may be used.

  The absorbent 6 is a member for imparting water-stopping properties to the optical fiber cable 1, and also functions as a press roll wound on the outer peripheral surface 4 of the slot rod 3. The absorbent material 6 is composed of, for example, a water-absorbing fiber obtained by fiberizing a water-absorbing resin, a water-absorbing tape (a water-absorbing powder that is a water-swellable material attached to the inner surface) or the like.

  The jacket 7 is a covering member provided in the outermost layer in order to protect the optical fiber core wire from the laying environment, and is made of a polyethylene resin or the like having excellent mechanical strength or flame retardancy. Note that a color band may be provided on the outer cover in order to improve discrimination.

  The outer jacket tear string 8 is a string inserted or embedded in the longitudinal direction of the optical fiber cable 1 of the outer jacket 7, and for tearing the outer jacket 7. By pulling out the jacket tear string 8, the jacket 7 can be torn in the longitudinal direction and the optical fiber unit 10 can be taken out. The jacket tear string 8 is made of a plastic material (for example, polyester) that is resistant to pulling.

  The optical fiber units 10 (10A to 10E) are accommodated in slot grooves 5 (5A to 5E) formed in the slot rod 3, respectively.

FIG. 2 is a schematic configuration diagram showing one form of the optical fiber unit 10 housed in the optical fiber cable 1.
The optical fiber unit 10 includes seven optical fiber cores 11 (11a to 11g) and one bundle optical fiber core 12 used for bundling the seven optical fiber cores 11. . That is, the seven optical fiber cores 11 are used as optical fiber cores for optical transmission for communicating optical signals, and the one optical fiber core 12 is used as an optical fiber core for optical transmission. In addition, it is also used as a bundle material for bundling the other seven optical fiber core wires 11. The optical fiber unit 10 is configured by closely assembling seven optical fiber cores 11 and winding and bundling one bundle optical fiber core 12 around the optical fiber cores 11.

  The bundled optical fiber core 12 may have the same configuration as the other optical fiber cores 11, but other optical fibers may be used to improve discrimination or suppress deterioration of transmission characteristics. A configuration different from that of the core wire 11 may be used.

Next, the single optical fiber core wire 11 (12) will be described with reference to FIG.
The optical fiber core wire 11 (12) includes a glass fiber 21 composed of a core 21a and a clad 21b, a protective coating 22 covering the outer periphery of the glass fiber 21, and further covering the outer periphery of the protective coating 22 and each light. A colored coating 23 colored so as to be distinguishable between the fiber cores is provided.

  As the glass fiber 21, a glass fiber having any curvature distribution such as a glass fiber including a core 21 a and a plurality of layers of clads 21 b. Further, as the optical fiber core wire 11 (12), a colored protective film 24 may be further provided on the outer periphery of the colored film 23. Further, the outer periphery of the glass fiber 21 may be covered with the protective coating 22 and the colored protective coating 24 so that the colored coating 23 is not provided.

  Specifically, as the optical fiber core wire 11 (12), for example, a glass fiber 21 having an outer diameter of 125 μm and an outer diameter of 250 μm coated with an ultraviolet curable resin as the protective coating 22 is used. The colored coating 23 has a thickness of about 1 μm to 10 μm. Furthermore, when the outer periphery of the colored coating 23 is coated with a plastic resin as the protective coating 24, the outer diameter of the optical fiber core wire 11 (12) is 500 μm.

  Returning to FIG. 2, as the optical fiber core wire 11 (11a to 11g) and the bundle optical fiber core wire 12 constituting the optical fiber unit 10, those having the following configurations can be used.

  In order to easily identify the seven optical fiber cores 11 (11a to 11g) and the one bundle optical fiber core 12 that bundles the seven optical fiber cores 11 (11a to 11g), The fiber cores having different thicknesses (outer diameters) can be used. For example, a core wire having an outer diameter of 250 μm can be used as the optical fiber core wire 11 (11a to 11g), and a core wire having an outer diameter of 500 μm can be used as the bundle optical fiber core wire 12. The outer diameter of the bundle optical fiber 12 is preferably 200 to 500 μm.

  Further, in order to easily identify the optical fiber core wire 11 (11a to 11g) and the bundle optical fiber core wire 12, the colors of the optical fiber core wires may be different. This color can be set by the color of the colored coating 23 or the color of the protective coating 24. For example, the colors of the optical fiber cores 11 (11a to 11g) are set to different colors (red, orange, yellow, green, blue, purple, gray, white), respectively, and the bundle optical fiber core 12 Can be set to a different color (brown).

  Moreover, you may make it make the color of an optical fiber core wire different for each optical fiber unit 10A-10E arrange | positioned for each of the five slot grooves 5A-5E provided in FIG. When the color of each optical fiber core of the optical fiber unit 10A disposed in the slot groove 5A is set as described above, the color of each optical fiber core of the optical fiber unit 10B disposed in the slot groove 5B The optical fiber core wires 11 (11a to 11g) are set to different colors (brown, orange, yellow, green, blue, purple, gray, white) in order, and the optical fiber core wires 12 for bundles are set. Can be set to a color (red) different from these. Similarly, the colors of the optical fiber cores of the optical fiber unit 10C disposed in the slot groove 5C are colors (brown, red, yellow) that are different from the colors of the optical fiber cores 11 (11a to 11g) in order. , Green, blue, purple, gray, white), and the color of the bundle optical fiber 12 can be set to a different color (orange).

  As a result, when searching for any one of the optical fiber cores in the optical fiber cable 1, the optical fiber core wire “red” of the bundle optical fiber “red” is simply designated, or more simply “red”. It is possible to identify and specify that the corresponding optical fiber core wire is the blue optical fiber core wire in the optical fiber unit 10B disposed in the slot groove 5B. .

  Similarly, when a plurality of optical fiber units are accommodated in the slot grooves 5A to 5E, the color of the optical fiber core 11 (11a to 11g) and the bundle optical fiber core 12 are similarly set for each optical fiber unit. Different colors may be used. Also in this case, the same effect can be obtained.

  Furthermore, a configuration in which the thickness (outer diameter) of the optical fiber core is made different from a configuration in which the color of the optical fiber core is made different may be combined. In this case, since the two identification elements of the outer diameter and the color are provided, a higher identification effect can be obtained.

  Further, in order to maintain the high transmission characteristics of the optical fiber cable 1, a core wire having an outer diameter of 500 μm can be used as the bundle optical fiber core wire 12. The bundle optical fiber core wire 12 is used in a state bent to some extent. In order to suppress the deterioration of the transmission characteristics of the bundle optical fiber core 12 due to the bending, it is preferable to use a 500 μm core wire (thick core wire) having a smaller decrease rate.

  When a plurality of optical fiber cores 11 (11a to 11g) are bundled by one bundle optical fiber core wire 12, it is necessary to wind them at a narrow pitch to some extent in order to secure the binding property. However, although the binding property can be ensured by winding at a narrow pitch, the optical fiber core is bent by a larger amount by the narrow pitch, and the transmission characteristics of the bundle optical fiber 12 are deteriorated. May end up. Therefore, in order to satisfy the requirements of both the binding property and the transmission characteristic, it is preferable to set the winding pitch of the bundle optical fiber core wire 12 to 50 to 500 mm. It is more preferable to set the winding pitch to 200 mm or less in order to ensure a sense of unity between the optical fiber units and high transmission characteristics.

  Further, the number of optical fiber cores constituting one unit is not limited to this form. For example, it may be a unit bundled for every four optical fiber cores, for every 10, ten optical fiber core wires, or the like. Further, the number of slot grooves 5 is not limited to the number (5) in this form.

  Next, with reference to FIG. 4, the modification 1 of an optical fiber unit is demonstrated. In the modification 1, the two optical fiber core wires 12a and 12b for bundles are used as the optical fiber core wire for bundling the optical fiber core wires 11 (11a to 11f). As shown in FIG. 4, the bundle optical fiber cores 12a and 12b are wound around the outer periphery of the optical fiber core wire 11 (11a to 11f).

  In this way, the number of the bundle optical fiber cores 12 for bundling the optical fiber core wires 11 is plural (two in this example), and compared with the case of bundling with one bundle optical fiber core wire 12. Thus, the binding property can be maintained while setting the winding pitch of the bundle optical fiber core wires 12 (12a and 12b) wide. That is, compared to the case of bundling with a single bundle optical fiber core wire 12, it becomes a configuration that can easily satisfy both requirements of binding property and transmission characteristics.

  The number of the bundle optical fiber core wires 12 is not limited to two, and may be three or more. In particular, when the number of optical fiber cores 11 to be bundled is large, the number of optical fiber core wires 12 for bundles may be increased from the viewpoint of satisfying both requirements of binding property and transmission characteristics.

Next, with reference to FIG. 5, the modification 2 of an optical fiber unit is demonstrated.
In the second modification, a laminated optical fiber unit 40 is configured by bundling a plurality (three in this example) of optical fiber ribbons 41, 42, and 43 by a bundle optical fiber 12c.

  The optical fiber ribbon 41 has an even number (four in this example) of optical fiber cores 41a, 41b, 41c, 41d arranged in parallel, and the outer periphery of the optical fiber ribbon cores 41a, 41b, 41c, 41d are formed integrally and in the longitudinal direction. 41e. The optical fiber ribbons 42 and 43 have the same configuration.

  The bundle optical fiber core 12c is an optical fiber core provided separately from the optical fiber cores 41a, 41b, 41c, 41d and the like constituting the optical fiber tape cores 41, 42, 43. The optical fiber core wire 12c for bundling bundles the optical fiber core wires constituting the optical fiber tape core wires 41, 42, 43 by being wound around the outer periphery of the optical fiber tape core wires 41, 42, 43. Thus, the present invention can also be applied to a configuration in which a plurality of optical fiber ribbons 41, 42, 43 are bundled.

  As the bundle optical fiber core wire 12c, one of the optical fiber core wires 41a, 41b, 41c, 41d constituting the optical fiber tape core wires 41, 42, 43 is separated and taken out. It may be used as an optical fiber core wire. Further, a plurality of bundle optical fiber cores may be used, and an optical fiber tape core wire may be used as the bundle optical fiber core wire.

  Further, even in the case of the laminated optical fiber unit 40 constituted by a plurality of optical fiber ribbons 41, 42, 43, the distinctiveness can be improved by changing the color or diameter of the bundle optical fiber core 12. Alternatively, it is the same as in the above-described example that the requirements for binding and transmission characteristics can be satisfied by appropriately setting the winding pitch.

  Moreover, the number of optical fiber ribbons constituting the laminated optical fiber unit 40 and the number of optical fiber strands constituting the optical fiber ribbon are not limited to this example.

  As described above, according to the optical fiber cable 1 of the present embodiment, a plurality of optical fiber core wires (11, 41 to 43) constituting the optical fiber unit (10, 30, 40) are bundled. In place of the thread-like or tape-like member used as the bundle material, the optical fiber core wire 12 (12a, 12b, 12c) is not only used as an optical fiber core wire for optical transmission, but also a plurality of other light beams. It is also used as a bundle material for bundling the fiber core wires (11, 41 to 43). Thereby, size reduction of an optical fiber unit (10, 30, 40) can be achieved, and the multi-fiber and high-density optical fiber cable 1 can be implement | achieved. Further, the number of members used can be reduced, and cost reduction can be realized.

  While the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

  1: optical fiber cable, 2: tension member (strength member), 3: slot rod, 5: slot groove, 6: absorbent, 7: jacket, 8: jacket tear string, 10 (10A to 10E), 30 : Optical fiber unit, 11 (11a to 11g): Optical fiber core wire, 12, 12a, 12b, 12c: Optical fiber core wire for bundle, 21: Glass fiber, 21a: Core, 21b: Clad, 22, 24: Protection Coating, 23: colored coating, 40: laminated optical fiber unit

Claims (8)

An optical fiber cable containing an optical fiber unit configured by bundling a plurality of optical fiber cores,
An optical fiber cable, wherein an optical fiber core wire is used as a bundle material for bundling the plurality of optical fiber core wires.   2. The optical fiber cable according to claim 1, wherein a diameter of an optical fiber core wire used as the bundle material is 200 to 500 μm.   The optical fiber cable according to claim 1 or 2, wherein a winding pitch of the optical fiber core wire used as the bundle material is 50 to 500 mm.   4. The optical fiber cable according to claim 1, wherein the number of optical fiber cores used as the bundle material is plural.   5. The diameter of the optical fiber cores used as the bundle material is different from the diameter of the bundled optical fiber cores. 6. Fiber optic cable.   The optical fiber cable according to claim 5, wherein a diameter of the optical fiber core wire used as the bundle material is larger than a diameter of the bundled optical fiber core wires.   7. The color of the optical fiber cores used as the bundle material is different from the color of the bundled optical fiber cores. 8. Fiber optic cable.   The plurality of optical fiber units are housed, and the color of the optical fiber core wire used as the bundle material is different for each optical fiber unit. An optical fiber cable as described in 1.

Images