JP2018036369A - Slot rod for fiber cable, and optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slot rod for a fiber cable and an optical fiber cable that are capable of suppressing fall-down of ribs in manufacturing a slot rod.SOLUTION: There is provided a slot rod 20 for an optical fiber cable that includes slot ribs 23 for forming plural streaks of slot grooves 22. The outermost circumferential surface of the slot ribs is recessed toward the center of the slot rod. Preferably, the slot ribs each have rib bend portions 24c on side faces extending in a radial direction of the slot rod, and are provided with a rib tip end 24 with a roughly Y-shape formed on a side closer to an outer circumference side than the rib bend portions.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a slot rod and an optical fiber cable for an optical fiber cable, and more particularly to a slot rod and an optical fiber cable for an optical fiber cable having ribs forming a plurality of grooves.

  Some types of optical fiber cables include slot rods (also referred to as spacers) in which a plurality of grooves are formed. Each groove accommodates an optical fiber ribbon (hereinafter referred to as a tape ribbon) in which a plurality of optical fibers are arranged in parallel, a single-fiber ribbon, or the like. The outside of the slot rod is wound with, for example, a press-wrapping tape, and further covered with a cable jacket (also referred to as a sheath).

  In order to efficiently construct an FTTH (Fiber To The Home) wiring network that provides a high-speed communication service, it is preferable to store tape core wires, single-core optical fiber core wires, and the like in grooves at high density. However, if the ribs constituting the gaps are narrowed to increase the cross-sectional area of the grooves, the ribs may fall due to insufficient strength of the ribs (also referred to as rib collapse). For this reason, for example, Patent Document 1 discloses a technique for defining the thickness of the rib, and Patent Document 2 discloses a technique for forming the rib into a two-layer structure of an inner layer and an outer layer.

JP 2003-195129 A JP 2002-228901 A

  However, in the methods described in Patent Literatures 1 and 2, the shape of the rib becomes complicated and the cost increases. For this reason, further improvement for suppressing rib collapse by a simple method is desired.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a slot rod for an optical fiber cable and an optical fiber cable that can suppress rib collapse at the time of manufacturing the slot rod. .

  A slot rod for an optical fiber cable according to an aspect of the present invention is a slot rod for an optical fiber cable having ribs forming a plurality of grooves, and an outermost peripheral surface of the rib is the slot rod of the slot rod. It is recessed toward the center.

  According to the above, rib collapse during manufacturing of the slot rod can be suppressed.

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 fiber cable by 2nd Embodiment. It is a figure for demonstrating the slot rod of FIG. It is a figure for demonstrating the front-end | tip part Y-shaped rib.

[Description of Embodiment of the Present Invention]
First, the contents of the embodiment of the present invention will be listed and described.
A slot rod for an optical fiber cable according to an aspect of the present invention is (1) a slot rod for an optical fiber cable having a rib that forms a plurality of grooves, and the outermost peripheral surface of the rib is It is recessed toward the center of the slot rod. Since the tip portion of the rib is lightened by the recess provided on the outer peripheral surface of the rib, rib collapse at the time of manufacturing the slot rod can be suppressed by a simple method. Moreover, since a fiber can be accommodated in a hollow part, further densification can be achieved.

(2) The rib has a bent portion on a side surface extending in the radial direction of the slot rod, and includes a substantially Y-shaped rib tip portion formed on the outer peripheral side from the bent portion. Compared to the case without a Y-shaped rib tip, the groove width around the outermost peripheral surface of the rib is reduced, but the groove height can be increased, resulting in an increase in the cross-sectional area of the groove. it can. Therefore, the cross-sectional area of the groove can be increased without changing the outermost peripheral position of the slot rod.

  An optical fiber cable according to an aspect of the present invention includes (3) the above-described slot rod, a press-winding tape wound around the slot rod, and a cable jacket provided around the press-wrapping tape. ing. It is possible to provide an optical fiber cable in which a tape core wire or a single optical fiber core wire is stored in a groove at a high density.

[Details of the embodiment of the present invention]
DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a slot rod for an optical fiber cable and 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, and FIG. 2 is a diagram showing an example of the structure of an intermittent tape core wire.

The optical fiber cable 1 shown in FIG. 1 includes a slot rod 20, a press-wound tape 30 wound vertically or horizontally around the slot rod 20, and a cable jacket applied around the press-wound tape 30. 31.
The slot rod 20 has a tension member 21 embedded in the center thereof. The tension member 21 is made of a wire having a resistance to tension and compression, for example, a steel wire or FRP (Fiber Reinforced Plastics).

Further, a plurality of (for example, five) spiral or SZ-shaped slot grooves 22 are formed on the outer peripheral surface of the slot rod 20 along the longitudinal direction of the cable. The slot groove 22 corresponds to the groove of the present invention.
In the slot groove 22, for example, 100 pieces of four intermittent tape cores 10 are used to accommodate 400 pieces.

  The intermittent tape core wire is formed by arranging a plurality of optical fiber core wires in parallel 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 parallel (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. Yes.

  The optical fiber core wire constituting the intermittent tape core wire is further coated with a colored coating on the outside of what is called an optical fiber strand in which a glass fiber having a standard outer diameter of 125 μm is coated with a coating outer diameter of about 250 μm. The example of FIG. 2 has four cores, but the number of optical fiber core wires can be arbitrarily determined. In addition, an intermittent tape core does not need to provide a connection part and a non-connection part for every 1 core, for example, even if it connects the core wires which integrated 2 cores with a connection part and a non-connection part intermittently Good.

As shown in FIG. 1, the slot rod 20 is wound with a press-wound tape 30 so that the intermittent tape core wire 10 does not jump out, and is collected into, for example, a substantially pentagonal shape.
As the press-wrapping tape 30, for example, a non-woven fabric formed in a tape shape, a laminate of a base material such as polyethylene terephthalate (PET) and the non-woven fabric, or the like is used. In addition, you may provide a water absorbing agent (for example, water absorption powder) to the press-wound tape. If the holding tape functions as a water absorbing layer, it is possible to stop water on the intermittent tape core.

  The outer side of the press-wound tape 30 is covered with a cable jacket 31 made of, for example, PE (polyethylene), PVC (polyvinyl chloride), or the like, and is formed in a round shape, for example.

  Here, the slot rod 20 has, for example, five slot ribs 23 extending radially from the periphery of the tension member 21, and the slot ribs 23 form slot grooves 22, which are separated from the other slot grooves 22. Yes. The slot rib 23 corresponds to the rib of the present invention. A rib tip 24 having a recess 26 is formed on the outer peripheral side of each slot rib 23.

Specifically, as shown in FIG. 1, the outermost peripheral surface of the slot rib 23 (the surface located on the outermost peripheral side in the radial direction of the rib, also referred to as the rib head) is recessed toward the center of the slot rod 20. A recess 26 is formed in the rib tip 24.
Thereby, since the front-end | tip part of the slot rib 23 can be lightened, the rib collapse at the time of manufacture of a slot rod can be suppressed. In addition to the slot groove 22, the tape core or single-core optical fiber can be stored in the recess 26, so that an optical fiber cable stored at a high density can be provided.

FIG. 3 is a diagram illustrating an example of an optical fiber cable according to the second embodiment, FIG. 4 is a diagram for explaining the slot rod of FIG. 3, and FIG. 5 is a diagram illustrating a Y-shaped rib at the tip portion. FIG.
The slot ribs 23 according to the first embodiment are formed with the same width. However, as shown in FIGS. 3 to 5, the slot ribs 23 according to the second embodiment are gradually narrowed as they approach the rib tip 24. It may be formed so as to spread at the tip.

  Specifically, as shown in FIG. 5, each slot rib 23 includes a rib base 25 extending from between the groove bottoms 22a of adjacent slot grooves 22 with a rib bent portion 24c described later as a boundary, and a rib base. 25 and a substantially Y-shaped rib front end portion 24 provided outside. A recessed portion 26 is formed in the rib tip portion 24 as in the first embodiment. Therefore, rib collapse at the time of manufacturing the slot rod can be suppressed, and a tape core or the like can be stored in the recess 26.

More specifically, if the hollow portion 26 of the slot rib 23 described in the first and second embodiments is approximated by a triangle, the thickness of the slot rib 23 (the length of the rib bent portion 24c in the second embodiment, hereinafter referred to as rib). (Referred to as thickness) 1.1 mm and the depth of the recess 26 is 0.5 mm, the area of one recess 26 is 1.1 × 0.5 × 1/2 = 0.275 mm ² , and the slot groove The total area of the recess 26 in Equation 5 is 0.275 × 5 = 1.375 mm ² . Therefore, the five hollow portions 26 can accommodate 1.375 / (π × (0.26 / 2) ² ) = 25 optical fiber core wires (φ0.26 mm).

Further, the rib base portion 25 has the narrowest width at the boundary position with the rib tip end portion 24 (position of the rib bent portion 24c). For example, the rib bent portion 24c is provided closer to the rib top 24b than the position of ½ of the length from the rib top 24b to the groove bottom 22a (hereinafter referred to as rib height).
The rib tip 24 includes a rib head 24b that forms the upper portion of the Y shape, a rib bent portion 24c that is provided inside the rib head 24b and forms the lower end of the Y shape, and a side surface of the Y shape. And a rib side wall 24a. The rib tip portion 24 is formed so as to gradually become thicker as it is separated from the rib base portion 25, and the rib bent portion 24c is formed with a width shorter than the rib top portion 24b.

  Thus, if the Y-shaped rib tip 24 is provided, the groove width around the outermost peripheral surface of the slot rib is narrower than the slot rib described in the first embodiment, but the height of the slot groove is increased. In particular, the height of the slot groove at the outermost peripheral position of the slot rod can be gained, and the cross-sectional area of the slot groove can be increased without changing the outermost peripheral position of the slot rod (that is, the diameter of the cable). Therefore, it is possible to provide an optical fiber cable in which a tape core wire or the like is stored in the slot groove with high density.

(Comparative Example 1)
In the case of a slot rod configured with five slot grooves, a rib height of 3 mm, a constant rib thickness of 1.1 mm, and no recess, a total of 400 optical fiber cores could be accommodated in the five slot grooves. . However, in Comparative Example 1, rib collapse occurred.
Example 1
Example 1 described in the first embodiment, that is, in the case of a slot rod configured with 5 slot grooves, 3 mm rib height, 1.1 mm constant rib thickness, and 0.5 mm deep recess 26 depth A total of 400 optical fiber cores could be stored in the five slot grooves 22, and a total of 25 optical fiber cores could be stored in the five recesses 26. Moreover, rib collapse did not occur.

(Example 2)
Example 2 described in the second embodiment, that is, the number of slot grooves is 5, the rib height is 3 mm, the rib thickness (rib bent portion 24 c) is 1.1 mm, the Y-shaped rib tip portion 24, and the recess portion 26. In the case of a slot rod having a depth of 0.5 mm, a total of 420 optical fiber cores can be accommodated in the five slot grooves 22, and a total of 25 optical fiber cores can be accommodated in the five recesses 26. did it. Moreover, rib collapse did not occur.

  1 and 3, an example in which five slot grooves 22 are formed by five slot ribs 23 is described. However, the number of slot ribs and slot grooves is not limited to this. Further, it is possible to provide a tracer mark for identifying the position of the slot groove 22 on the outermost peripheral surface of the slot rib 23.

  As described above, the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is not limited to the examples described above, but is defined by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope 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, 20 ... Slot rod, 21 ... Tension member, 22 ... Slot groove, 22a ... Groove bottom, 23 ... Slot rib, 24 ... Rib tip, 24a ... Rib side wall, 24b ... Rib head, 24c ... Rib bent part, 25 ... Rib base, 26 ... Recessed part, 30 ... Pressing tape, 31 ... Cable Jacket.

Claims (3)

A slot rod for an optical fiber cable having ribs forming a plurality of grooves,
A slot rod, wherein an outermost peripheral surface of the rib is recessed toward a center of the slot rod.   2. The slot rod according to claim 1, wherein the rib has a bent portion on a side surface extending in a radial direction of the slot rod, and includes a substantially Y-shaped rib tip portion formed on an outer peripheral side from the bent portion. . An optical fiber cable comprising the slot rod according to claim 1, a press-winding tape wound around the slot rod, and a cable jacket provided around the press-winding tape.

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