JP6413593B2 - Fiber optic cable - Google Patents

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, there is an increasing demand for wiring work in which an optical fiber cable is disassembled and distributed to a plurality of terminals.

  Here, when the optical fiber core wire is buried in the extruded cable jacket, it is difficult to take out the optical fiber core wire when the optical fiber cable is disassembled. Thus, for example, Patent Document 1 discloses a technique of an optical unit in which a plurality of optical fiber cores are bundled and wrapped with a film.

Japanese Unexamined Patent Publication No. 2014-77869

  However, in the technique of Patent Document 1, the extruded cable jacket is blocked by the film and does not reach the optical fiber core, but reaches the periphery of the optical unit. For this reason, when bending force is given to an optical unit with the pressure from a cable jacket, there exists a problem that an optical fiber core wire may be damaged. Further, when the optical unit is buried in the cable jacket, there is a problem that it is difficult to take out the optical unit when the optical fiber cable is disassembled.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical fiber cable that prevents damage to an optical fiber core and facilitates removal of an optical unit.

An optical fiber cable according to an aspect of the present invention includes an optical unit row in which optical units each formed by collecting a plurality of tape cores are arranged in a row, and two tension members disposed on both sides of the optical unit row. And two intervening tapes arranged across the optical unit row in a direction perpendicular to the line connecting the two tension members, and the two tension members and the two intervening tapes are collectively covered. An optical fiber cable provided with a cable jacket, wherein the cable jacket is filled inside the optical unit array, which is partitioned by the two tension members and the two intervening tapes. is to have a inner space not, the two intervening tape, so as to approach the segment ends of the respective tape connecting tension members of the two, position in contact with the tension member of the two That it not deflected in.

  According to the above, it is possible to provide an optical fiber cable that can prevent the optical fiber core wire from being damaged and that can easily take out the optical unit when the optical fiber cable is disassembled.

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 explanatory drawing when taking out an optical unit from the optical fiber cable of 2nd Embodiment. 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) an optical unit array in which optical units each formed by collecting a plurality of tape cores are arranged in a line; and two optical units arranged on both sides of the optical unit array. Tension members, two intervening tapes sandwiched between the optical unit rows in a direction perpendicular to the line connecting the two tension members, the two tension members and the two intervening tapes An optical fiber cable having a cable jacket that covers all of the cables, wherein the optical unit array is disposed, and the cable outer sheath is disposed inside the two tension members and the two intervening tapes. possess an inner space which the is not filled, the two intervening tape, so as to approach the segment ends of the respective tape connecting tension members of the two, contacts the tension members of the two That that not bent at the position.
An optical unit in which a plurality of tape cores are collected is arranged in a line between two tension members, and even if bending force is applied to the optical fiber cable, the load is a part of the tape core. Concentration on the optical fiber core can be avoided, and damage to the optical fiber core due to bending strain can be prevented. Further, an inner space not filled with the cable jacket is formed around the optical unit, and the bending force due to the pressure from the cable jacket does not act on the optical unit, so that the optical fiber core wire can be prevented from being damaged. Furthermore, it is easy to take out the optical unit when the optical fiber cable is disassembled. If the intervening tape is bent and comes into contact with the tension member, the inner space not filled with the cable jacket can be more securely secured.

( 2 ) On the long diameter surface of the cable jacket whose cross-sectional outer shape is formed in an oval shape, there are two pairs of notches formed by sandwiching the two tension members, respectively, It is formed toward the center side of the optical fiber cable. If the tip of the notch is directed toward the center of the optical fiber cable, it becomes easier to grasp each notch with a tool when the optical fiber cable is disassembled.
( 3 ) The cable jacket having a cross-sectional outer shape formed in a rectangular shape or an oval shape has two pairs of notches formed by sandwiching the two tension members on the longitudinal surface or the long diameter surface of the cable jacket, The tension member is disposed on a line connecting the tips of the notches. If the tension member is arranged on the line connecting the notch tips, damage to the optical fiber core can be prevented when the optical fiber cable is disassembled.
( 4 ) In the direction orthogonal to the line segment connecting the two tension members, the width of the cable jacket in which the optical unit is arranged is the width of the cable jacket in which the optical unit arranged on both sides thereof is not arranged. It is made smaller than the width. The thickness of the end portion of the cable jacket is increased like a dumbbell, for example, and the pressure from the direction perpendicular to the line connecting the two tension members is received at the portion where the thickness is increased. Can provide fiber cable.

( 5 ) There is an interposition between the adjacent tension member and the optical unit. Since the contact between the tension member and the optical unit is avoided by the interposition, the external force is not transmitted from the tension member to the optical unit. This also contributes to preventing damage to the optical fiber core.
( 6 ) A water-absorbing agent is added to the interposition. If the interposition functions as a water-absorbing layer, water can be stopped to the optical unit.
( 7 ) The plurality of tape core wires are bundled with a bundle material, and a water absorbing agent is applied to the bundle material. If the bundle material functions as a water absorption layer, the optical unit can be identified and water stopped to the optical unit.

[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 has a cable jacket 30 in which, for example, two tension members 22 and two intervening tapes 24 are collectively covered. 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.

Here, the intermittent tape core wire is formed by arranging a plurality of optical fiber core wires in a parallel row and intermittently connecting adjacent optical fiber core wires by a connecting portion and a non-connecting portion.
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, for example, three optical units 17 are accommodated in the cable jacket 30, and a 72 (24 × 3) core optical fiber cable 1 is configured. These three optical units 17 are arranged in a row to form an optical unit row, and two tension members 22 are arranged on both sides of the optical unit row.
In this way, the optical units 17 are arranged in a row so that the centers thereof are positioned on, for example, a line segment (also referred to as a bending neutral axis) connecting the centers of the two tension members 22. The outer periphery of each is within, for example, 750 μm from the neutral axis of bending. For this reason, even if bending force is given to optical fiber cable 1, it can avoid that the load concentrates on a part of optical fiber cores, and can prevent damage to optical fiber core wires by bending distortion.

  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 1.0 mm, FRP (Fiber Reinforced Plastics), or the like is used. An adhesive layer 22 a 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.

  Two intervening tapes 24 are arranged in a direction orthogonal to the line segment connecting the two tension members 22, and are provided with the three optical units 17 interposed therebetween. The intervening tape 24 is a tape-like member made of, for example, polyethylene terephthalate (PET), for example, having a thickness of 0.1 mm or less, and is formed with a width that can contact the two tension members 22. The inner optical unit 17 can be protected at the time of extrusion of 30 or the disassembly of the optical fiber cable 1.

Specifically, the outer peripheral surface of the tension member 22 and the inner surface of the interposition tape 24 are in contact with each other, and entry of the cable jacket 30 can be prevented at this contact portion. Therefore, as shown in FIG. 1, the inner space in which the three optical units 17 are arranged and partitioned by the two tension members 22 and the two intervening tapes 24 is not filled with the cable jacket 30. S.
In this way, the inner space S is formed around the optical unit 17, and the bending force due to the pressure from the cable jacket 30 does not act on the optical unit 17, thereby preventing damage to the optical fiber core in the optical unit 17. it can.

In particular, as shown in FIG. 1, if the intervening tape 24 has a contact portion 24 a that contacts the outer peripheral surface of the tension member 22, and the contact portion 24 a is bent toward the tension member 22 by the pressure from the cable jacket 30. The internal space S can be secured more firmly.
The cable jacket 30 is formed in, for example, an oval shape (also referred to as a long-diameter flat type) having a major axis of about 10 mm and a minor axis of about 4 mm, and an upper surface 31 and a lower surface 32 that cover the outside of the intervening tape 24. And side surfaces 33 that cover the outside of the tension member 22. The upper surface 31 and the lower surface 32 correspond to the long diameter surface of the cable jacket of the present invention.

Also, two pairs of tear notches 35 formed by sandwiching the two tension members 22 are formed in the cable jacket 30 near the boundary between the upper surface 31 and the side surface 33 and near the boundary between the lower surface 32 and the side surface 33, for example. Has been. The tear notch 35 corresponds to the notch of the present invention.
The tear notch 35 is formed in a V-shaped cross section, and the tip located on the V-shaped bisector is formed toward the center side of the optical fiber cable 1 (for example, the tension member 22). For this reason, it becomes easy to grasp each notch with a tool (for example, slant blade nipper) at the time of disassembly of the optical fiber cable 1.

FIG. 4 is an explanatory diagram when the optical unit is taken out from the optical fiber cable of the first embodiment. First, as shown in FIG. 4A, when the two slit notches 35 formed near the boundary between the upper surface 31 and the side surface 33 of the cable jacket 30 are gripped with a tool, the intervening tape 24 starts from the tip of the slit notch 35. As a result, the upper surface 31 can be pulled upward.
When the pulled-up portion is cut with, for example, a cutter and the upper surface 31 gripped with a tool is peeled off along the longitudinal direction of the optical fiber cable 1, a state as shown in FIG. In some cases, the intervening tape 24 may be peeled off together with the upper surface 31 of the cable jacket 30.

  In the state of FIG. 4B, for example, when the side surfaces 33 and 33 are respectively grasped by hand and the optical fiber cable 1 is bent so that the exposed intervening tape 24 protrudes toward the upper surface 31, the end of the intervening tape 24 is connected to the cable. It appears away from the side surface 33 of the jacket 30. Then, if the intervening tape 24 is removed, the optical fiber cable 1 can be disassembled and the optical unit 17 can be taken out as shown in FIG. In particular, since the inner space S not filled with the cable jacket 30 is formed around the optical unit 17, the optical unit 17 can be easily taken out when the optical fiber cable 1 is disassembled.

  FIG. 5 is a diagram illustrating an example of an optical fiber cable according to the second embodiment of the present invention, and FIG. 6 is an explanatory diagram when an optical unit is taken out from the optical fiber cable of the second embodiment. In the second embodiment, the shape of the cable jacket and the tear notch is different from that of the first embodiment, and the optical unit 17, the tension member 22, and the interposition tape 24 are the same as those of the first embodiment. Explained.

The cable jacket 30 according to the second embodiment has a cross-sectional outer shape formed in, for example, a rectangular shape having a major axis of about 10 mm and a minor axis of about 4 mm (also referred to as a minor axis planar type), and covers the outside of the intervening tape 24. The upper surface 31 and the lower surface 32 and side surfaces 33 and 33 that cover the outside of the tension member 22 are provided.
The cable jacket 30 has a width from the upper surface 31 to the lower surface 32 of the cable jacket 30 in which the optical unit 17 is disposed in a direction perpendicular to the direction connecting the two tension members 22 (also referred to as a short cross-sectional direction). The width of the side surface 33 of the cable jacket 30 where the optical units 17 arranged on both sides thereof are not arranged is made smaller.

Thus, the thickness of the side surface 33 of the cable jacket 30 is increased more than the thickness from the upper surface 31 to the lower surface 32 like a dumbbell, for example. Therefore, an optical fiber cable with high side pressure resistance can be provided.
In addition, two pairs of tear notches 36 are formed in the cable jacket 30, for example, near the boundary between the upper surface 31 and the side surface 33 and near the boundary between the lower surface 32 and the side surface 33. Has been. The upper surface and the lower surface correspond to the longitudinal surface of the cable jacket of the present invention, and the tear notch 36 corresponds to the notch of the present invention.

The tear notch 36 is formed in a V-shaped cross section, and, for example, the tension member 22 is disposed on a line connecting the tips. Thereby, damage of an optical fiber core wire can be prevented when the optical fiber cable 1 is disassembled.
Specifically, as shown in FIG. 6 (A), when a cut is made by, for example, a cutter from four slit notches 36 formed in the cable jacket 30, the cut reaches the intervening tape 24 near the tension member 22. Enter to do.

  When the upper surface 31 and the lower surface 32 of the cable jacket 30 with cuts are pulled outward and the side surfaces 33 and 33 are also pulled outward, the cable jacket 30 is divided into four parts as shown in FIG. 6B. The optical unit 17 can be taken out.

FIG. 7 is a diagram showing an example of an optical fiber cable according to the third embodiment of the present invention. In the third embodiment, the shape of the tear notch and the like are different from those in the first embodiment, and the shape of the cable jacket 30, the optical unit 17, the tension member 22, and the interposition tape 24 are the same as those in the first embodiment.
In the third embodiment, there are intervening cords 26 between the adjacent tension members 22 and the optical unit 17, and the optical units 17 located at both ends are in contact with the two interposing tapes 24 and the intervening cords 26, and the cable. The outer cover 30 is in a non-contact state. The interposing string 26 corresponds to the interposition of the present invention.

In this manner, the contact between the tension member 22 and the optical unit 17 is avoided by the interposition string 26, so that no external force is transmitted from the tension member 22 to the optical unit 17. This also contributes to preventing damage to the optical fiber core.
Moreover, you may provide a water absorbing agent (for example, water absorption powder) to the interposition string 26. If the intervening string functions as a water absorption layer, water can be stopped to the optical unit.

Further, two pairs of tear notches 36 are formed in the cable jacket 30, for example, near the boundary between the upper surface 31 and the side surface 33 and near the boundary between the lower surface 32 and the side surface 33. Has been. The tear notch 36 is formed in a V-shaped cross section, and, for example, the tension member 22 is disposed on a line connecting the tips.
As a result, when the slits are cut from the four cut notches 36 by, for example, a cutter, the upper surface 31 and the lower surface 32 of the cable jacket 30 having the cuts are pulled outward, and the side surfaces 33 and 33 are also pulled outward, respectively. The outer cover 30 is divided into four, and the optical unit 17 can be taken out.

The tear notch shown in the third embodiment may be provided so that the boundary portion between the tension member 22 and the interposition string 26 is disposed on the extension line of the notch tip.
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, 22 ... Tension member, 22a ... Adhesive layer, 24 ... intervening tape, 24a ... contact portion, 26 ... intervening string, 30 ... cable jacket, 31 ... upper surface, 32 ... lower surface, 33 ... side surface, 35, 36 ... notch.

Claims (7)

An optical unit array in which optical units formed by collecting a plurality of tape cores are arranged in a line, two tension members arranged on both sides of the optical unit array, and a line segment connecting the two tension members An optical fiber cable comprising two intervening tapes arranged with the optical unit row sandwiched in a direction perpendicular to the cable, and a cable jacket covering the two tension members and the two intervening tapes together. There,
Placing the light unit string, the inside partitioned by the two tension members and the two intervening tape, have a inner space in which the cable jacket is not filled,
The two intervening tape, so as to approach the segment ends of the respective tape connecting tension members of the two, that have deflected at the position in contact with the tension member of the two optical fiber cables. The cable jacket having an oval cross-sectional outer shape has two pairs of notches formed by sandwiching the two tension members on the long diameter surface of the cable jacket, and the ends of the notches are formed on the optical fiber cable. of that are formed toward the center, the optical fiber cable according to claim 1. The cable jacket having a rectangular or oval cross-sectional outer shape has two pairs of notches formed on both sides of the two tension members on the long or long surface of the cable jacket, and the tips of the notches wherein the line connecting the tension members that are arranged, an optical fiber cable according to claim 1. In the direction perpendicular to the line connecting the two tension members, the width of the cable jacket in which the optical unit is disposed is larger than the width of the cable jacket in which the optical unit disposed on both sides thereof is not disposed. Ru is small, the optical fiber cable according to any one of claims 1 3. That having a interposed between the tension member and the light unit adjacent optical fiber cable according to any one of claims 1 4. Wherein the intervening water absorbing agent is that has been granted, the optical fiber cable according to claim 5. It said plurality of ribbons are bundled in bundles material, the said bundle material, water-absorbing agent that has been granted, the optical fiber cable according to any one of claims 1 6.

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