JP2016080747A - Optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber cable capable of preventing coated optical fibers from being damaged when a cable jacket is peeled.SOLUTION: An optical fiber cable 1 includes a cable core 20 housing coated optical fibers and covered by a wrapping tape 19, arranges at least two tension members 22 around the cable core, and entirely covers them with a cable jacket 30. The optical fiber cable includes, on a common tangent of two of the tension members in an outer peripheral side of the two tension members adjacent to each other, an air gap C of the cable jacket that communicates with an internal space S in which the cable core is disposed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical fiber cable that covers a plurality of optical fiber core wires with a cable jacket.

  In addition to increasing the communication speed and the amount of information due to the spread of information communication such as the Internet, the construction of optical networks is progressing to support bidirectional communication and large-capacity communication. In this optical network, FTTH (Fiber To The Home), which provides a high-speed communication service by directly connecting a communication carrier and each home with an optical fiber, has been started. For this reason, the demand for wiring work distributed to a plurality of terminals is increasing.

  Here, when the optical fiber core is accommodated and covered with the upper winding tape and the coarse winding is wound thereon, the coarse winding must be removed when the optical fiber cable is disassembled. It is difficult to take out. Thus, for example, Patent Document 1 discloses a technique for winding an upper winding tape (pressing winding tape).

Japanese Unexamined Patent Publication No. 2014-77877

  By the way, in the optical fiber cable of the said patent document 1, a cable jacket is shaved with tools, such as a peeler, until a tearing string appears. However, when cutting the cable jacket, there is a problem that the optical fiber core wire is damaged if the blade of the tool exceeds the tear string or the upper winding tape.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an optical fiber cable that can prevent damage to the optical fiber core wire when the cable jacket is cut.

  An optical fiber cable according to an aspect of the present invention includes a cable core that accommodates an optical fiber core wire and is covered with an upper tape, and at least two tension members are arranged around the cable core. An optical fiber cable that is collectively covered with a jacket, and is an internal space of the cable jacket in which the cable core is disposed on the common tangent line of the two tension members on the outer peripheral side of the two adjacent tension members It has a void leading to.

  According to the above, damage to the optical fiber core wire in the cable core can be prevented.

It is a figure which shows an example of the optical fiber cable by 1st Embodiment of this invention. It is a figure which shows an example of the structure of an intermittent tape core wire. It is a figure which shows an example of the optical unit which twisted together the intermittent tape core wire. It is explanatory drawing when taking out an optical unit from the optical fiber cable of 1st Embodiment. It is a figure which shows an example of the optical fiber cable by 2nd Embodiment of this invention. It is a figure which shows an example of the optical fiber cable by 3rd Embodiment of this invention.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.
An optical fiber cable according to an aspect of the present invention includes (1) a cable core that accommodates an optical fiber core wire and is covered with an upper winding tape, and at least two tension members are arranged around the cable core. An optical fiber cable collectively covered with a cable jacket, the cable jacket having the cable core disposed on a common tangent line of the two tension members on the outer peripheral side of the two adjacent tension members. It has a space leading to the internal space.
When cutting the cable jacket with a tool, it comes into contact with the tension member before reaching the cable core, and the two adjacent tension members act as stoppers for the tool, so damage to the optical fiber in the cable core Can be prevented.

(2) A tearing member is formed in the gap along the longitudinal direction of the optical fiber cable to tear the cable jacket. If a tearing member is provided, the optical fiber cable can be easily disassembled in the longitudinal direction.
(3) The cable jacket is formed with an outer peripheral projection that allows the formation position of the gap to be recognized from the outside. The outer peripheral projection serves as a mark when cutting the cable jacket.
(4) The cable jacket is formed with a notch for recognizing the formation position of the gap from the outside. The notch serves as a mark when cutting the cable jacket.

[Details of the embodiment of the present invention]
Hereinafter, preferred embodiments of an optical fiber cable according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram showing an example of an optical fiber cable according to the first embodiment of the present invention. Moreover, FIG. 2 is a figure which shows an example of the structure of an intermittent tape core wire, and FIG. 3 is a figure which shows an example of the optical unit which twisted together the intermittent tape core wire. The following optical fiber cable 1 will be described with respect to a structure without a support line, but may be a self-supporting structure with a support line.

  As shown in FIG. 1, the optical fiber cable 1 includes a cable jacket 30 that collectively covers a cable core 20 and, for example, four tension members 22. The cable jacket 30 is formed of a thermoplastic resin such as an olefin resin (for example, low density polyethylene) and houses an optical unit (also referred to as a subunit) 17. The optical unit 17 has, for example, a set of 24 (4 × 6) cores by gathering 6 pieces of 4 intermittent tape core wires.

Specifically, FIG. 2A shows a state in which the intermittent tape core wire is closed, and FIG. 2B shows a state in which the intermittent tape core wire is opened in the arrangement direction. Four optical fiber cores 11 to 14 are arranged in a parallel line (also referred to as a four-fiber intermittent tape core wire), and adjacent optical fiber core wires are intermittently connected by a connecting portion 15a and a non-connecting portion 15b. ing.
As an optical fiber core housed in the intermittent tape core wire, a so-called optical fiber strand obtained by coating a glass fiber having a standard outer diameter of 125 μm with a coating outer diameter of about 250 μm, A coating or a colored coating may be applied, and the number of optical fiber cores accommodated is arbitrary. In addition, the intermittent tape core does not necessarily have a connection part and a non-connection part for every one core, for example, two cores integrated with each other are intermittently connected by a connection part and a non-connection part. May be.

The optical unit 17 is formed by, for example, spirally twisting six sheets of intermittent tape core wires 10 as shown in FIG. 3A, and as shown in FIG. It is bundled with. Note that, for example, three sets of two-layered intermittent tape cores bundled with bundles of various colors may be prepared and then twisted together in a spiral shape, for example.
In addition, the bundle material 18 can be configured by a tape having a width of, for example, about 2 mm, or two intersecting strings, but may be provided with a water absorbing agent (for example, a water absorbing powder). If the bundle material functions as a water absorption layer, the optical unit can be identified and water stopped to the optical unit.

As shown in FIG. 1, the optical fiber cable 1 includes a cable core 20 in which, for example, three optical units 17 are assembled to form a 72 (24 × 3) core and the outer periphery thereof is covered with an upper winding tape 19. .
The upper winding tape 19 is made of, for example, a non-woven fabric containing polyester fibers such as polyethylene terephthalate (PET), and is wound in the longitudinal direction of the cable core 20, for example. As a result, the upper tape 19 may function as a water-absorbing layer by applying a water-insulating agent (for example, water-absorbing powder) in order to stop the cable jacket 30 from being thermally insulated when the cable jacket 30 is extruded. it can.

Here, the cable core 20 is disposed in the internal space S of the cable jacket 30, and for example, four tension members 22 are provided around the cable core 20, but the distances between the adjacent tension members 22 are equal. They are evenly arranged.
When two tension members are provided around the cable core as in the prior art, the optical fiber cable is unlikely to bend in the direction in which the two tension members are connected, and is orthogonal to the line connecting these two tension members. It becomes easy to bend in the direction. On the other hand, if the four tension members are evenly arranged as in the present embodiment, the optical fiber cable can be provided in which the bending directionality does not occur because it bends similarly in any direction.

  The tension member 22 is also called a strength member, and a wire having resistance to tension and compression is used. As this wire, for example, a steel wire having an outer diameter of about 0.4 mm to 0.7 mm, FRP (Fiber Reinforced Plastics), or the like is used. An adhesive layer made of the same material as that of the cable jacket 30 is applied to the outer periphery of the tension member 22, and the tension member 22 adheres to the cable jacket 30 when the cable jacket 30 is pushed out.

  Further, a tearing member 21 for tearing the cable jacket 30 in the longitudinal direction is provided outside the upper winding tape 19. For example, two tearing members 21 are vertically attached to both sides of the cable core 20 when the cable jacket 30 is pushed out, and are in contact with the upper winding tape 19. If the tearing member 21 is used in this way, the optical fiber cable 1 can be easily disassembled in the longitudinal direction.

As shown in FIG. 1, a gap C may be provided on the outer side of the upper winding tape 19 instead of the tearing member 21. The gap C is formed in communication with the internal space S of the cable jacket 30.
Moreover, the embedding position of the tearing member 21 (or the position where the gap C is formed) is formed by, for example, integrally forming the outer peripheral projection 31 on the surface of the cable jacket 30 and cutting the cable jacket 30 with a tool (for example, a peeler). It may be a landmark.

  Here, the tearing member 21 (or the gap C) is installed on the common tangent line of the two tension members 22 on the outer peripheral side of the two adjacent tension members 22. Specifically, the outer peripheral side of the tension member 22 is a region opposite to the side facing the cable core 20. A tear member 21 (not on the cable core 20 but on the outer side of the cable core 20) is located on the common tangent line between the two tension members 22 adjacent to each other and at a substantially intermediate position between the two tension members 22. Alternatively, a gap C) is provided.

  FIG. 4 is an explanatory diagram when the optical unit is taken out from the optical fiber cable of the first embodiment. First, a tool is disposed on the surface of the cable jacket 30 with one outer peripheral projection 31 as a guide, and the cable jacket 30 is shaved until the blade of the tool contacts the two tension members 22. Is provided on a common tangent line between two adjacent tension members 22, the state shown in FIG. 4A is reached, and one tear member 21 is exposed before the blade contacts the tension member 22. To do.

Next, using the other outer peripheral projection 31 as a guide, a tool is placed on the surface of the cable jacket 30, and the cable jacket 30 is shaved until the blade of the tool contacts the two tension members 22. (B) will be in the state and the other tearing member 21 will also be exposed.
Then, when the exposed tearing members 21 are respectively picked and pulled along the longitudinal direction of the cable jacket 30, the cable jacket 30 is divided into two. Thereafter, for example, if the upper winding tape 19 is broken, the state shown in FIG. 4C is obtained, and the optical unit 17 can be taken out.

As described above, when the cable jacket 30 is cut with a tool, the tension member 22 comes into contact with the cable core 20 before reaching the cable core 20, and the adjacent two tension members 22 serve as stoppers for the tool. Can prevent damage to the optical fiber core wire.
In the case of the gap C, if the cable jacket 30 is shaved until the blade of the tool contacts the two tension members 22, the cable jacket 30 is divided into two parts. The optical unit 17 can be taken out.

FIG. 5 is a diagram showing an example of an optical fiber cable according to the second embodiment of the present invention. In the second embodiment, the number of outer peripheral protrusions and tearing members is two more than in the first embodiment, and the cable core 20 and the tension member 22 are the same as in the first embodiment.
In 2nd Embodiment, it is comprised by the four tearing members 21 and the four outer periphery protrusion parts 31, and the location which can cut the cable jacket 30 with a tool is increasing. As in the first embodiment, the tearing member 21 is on the common tangent line of the two tension members 22 on the outer peripheral side of the two adjacent tension members 22 and is substantially in the middle of the two tension members 22. The four tearing members 21 are also arranged at equal intervals.

FIG. 6 is a diagram showing an example of an optical fiber cable according to the third embodiment of the present invention. In the third embodiment, a notch 32 is formed instead of the outer peripheral protrusion, and in this case also, the cable jacket 30 can be cut using the notch 32 as a mark.
In each of the above embodiments, the example of four tension members has been described, but the number of tension members may be three or two as long as the tension member can serve as a stopper for the tool. In the case of two, for example, two adjacent members among the four tension members shown in FIG. 5 can be selected.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the meanings described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 ... Optical fiber cable, 10 ... Intermittent tape core wire, 11-14 ... Optical fiber core wire, 15a ... Connection part, 15b ... Non-connection part, 17 ... Optical unit, 18 ... Bundle material, 19 ... Top wound tape, 20 DESCRIPTION OF SYMBOLS ... Cable core, 21 ... Tearing member, 22 ... Tension member, 30 ... Cable jacket, 31 ... Outer peripheral projection, 32 ... Notch.

Claims (4)

An optical fiber cable that has a cable core that contains an optical fiber core and is covered with an overwrapping tape, and that has at least two tension members arranged around the cable core and is covered with a cable jacket. ,
An optical fiber cable having a gap communicating with an internal space of the cable jacket in which the cable core is arranged on a common tangent line of the two tension members on the outer peripheral side of the two adjacent tension members.   The optical fiber cable according to claim 1, wherein a tearing member is formed in the gap along the longitudinal direction of the optical fiber cable to tear the cable jacket.   3. The optical fiber cable according to claim 1, wherein an outer peripheral protrusion for recognizing the formation position of the gap from outside is formed on the cable jacket. The optical fiber cable according to claim 1 or 2, wherein the cable jacket is formed with a notch for recognizing the formation position of the gap from the outside.

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