WO2011111688A1

WO2011111688A1 - Optical fiber cable

Info

Publication number: WO2011111688A1
Application number: PCT/JP2011/055332
Authority: WO
Inventors: 悟塩原; 直樹岡田; 惇久野
Original assignee: 株式会社フジクラ
Priority date: 2010-03-08
Filing date: 2011-03-08
Publication date: 2011-09-15
Also published as: JP2011186156A

Abstract

Disclosed is a optical fiber cable, comprising optical fibers (1) positioned two or more cores in the x-axis direction, and two or more cores in the y-axis direction, where the x-axis is treated as the major axis and the y-axis is treated as the minor axis in a cross-section of a sheath (3); and tensile strength bodies (5, 5) that are positioned on either side of the optical fibers (1) in the x-axis direction in the cross-section of the sheath (3). Two pair of notches (A, A', B, B') are formed in mutual opposition in both surface portions in the Y-axis direction upon the sheath (3). In the cross-section of the sheath (3), two straight lines that join the opposing notches (A, B, A', B') are approximately parallel to the y-axis and pass through both x-axis direction end portions of the optical fibers (1).

Description

Fiber optic cable

The present invention relates to an optical fiber cable in which an optical fiber is covered with a sheath.

Optical fiber cables used in optical communications include overhead aggregating drop optical fiber cables installed as subscriber optical fiber cables and branching from aerial aggregated drop optical fiber cables to lead them into subscribers' homes Are used as overhead drop optical fiber cables.

As an aerial drop optical fiber cable for lead-in wiring to an apartment house such as an apartment or a condominium, as shown in FIG. 1, a self-supporting unit 101 and a cable main body 102 are connected via a neck 103. Support structure fiber optic cables are used. Note that an optical fiber cable used in a subscriber's house, a building, a condominium, or the like is an optical fiber cable having a structure including only a cable main body portion 102 that does not have the support wire portion 101.

The support wire portion 101 includes a support wire 104 made of steel wire. An optical fiber 105 and a tensile body 106 are built in the cable main body 102. A non-halogen flame retardant sheath is used as the outer sheath (sheath) 107 of such an optical fiber cable.

In the case of an optical fiber cable having a structure in which a multi-fiber optical fiber 105 is mounted, when the outer fiber 107 is torn out from a notch (cut groove) 108 in the cable body, the multi-fiber optical fiber 105 is taken out. There is a possibility that the optical fibers 105 on both side portions (portions close to the tensile body 106) of 105 are buried in the jacket 107 and remain. In this case, in order to take out these optical fibers 105 from the outer sheath 107, it is necessary to deform the outer sheath 107 by bending or twisting, and workability is poor, and the optical fiber 105 is broken during the operation. There is a fear.

In Patent Document 1, Patent Document 2 and Patent Document 3, in the optical fiber cable in which the multi-fiber optical fiber 105 is mounted, the workability of taking out the optical fibers located on both sides of the multi-fiber optical fiber 105 is improved. A structure has been proposed. That is, in the optical fiber cable having the structure described in these patent documents, the major axis direction of the cable body 102 is X-axis and the minor axis direction is Y in the cross section of the optical fiber cable, as shown in FIG. When defining the axis, when tearing the jacket 107, as shown in FIG. 2 (b), an oblique direction (other than the X-axis direction and the Y-axis direction) passing through the optical fibers on both sides of the multi-fiber optical fiber 105 The notch 108 or the deepest part of the notch 108 is positioned so that a crack is formed.

In Patent Document 4, Patent Document 5, Patent Document 6, and Patent Document 7, a structure 109 such as an inclusion or a peeling tape is mounted on the cable main body 102 together with the optical fiber 105 as shown in FIG. An optical fiber cable having a structure is described. In the optical fiber cable having this structure, the jacket 107 is cut by making a cut from a notch 108 provided on the surface of the jacket 107 of the cable body 102 toward the structure 109 such as an inclusion or a peeling tape. Are divided and the optical fiber 105 can be taken out.

JP 2005-338305 A JP 2006-267600 A JP 2007-047680 A Japanese Patent No. 4252991 Japanese Patent No. 4297372 JP 2009-186713 A JP 2009-217195 A

However, in the optical fiber cables described in Patent Document 1 to Patent Document 3, when the notch 108 is cut from the notch 108 to the outer cover 107 using a nipper or the like, the cross section of the optical fiber cable is cut. On the other hand, it is necessary to make a cut in an oblique direction, and the work is complicated. In addition, if the notch is detached from the notch 108, there is a problem in workability such that the outer jacket 107 is not easily torn.

In addition, in the optical fiber cables described in Patent Documents 4 to 7, it is necessary to mount the structure 109 such as an inclusion and a peeling tape together with the optical fiber 105. Therefore, the cost of these members increases. It becomes a factor. Further, in this optical fiber cable manufacturing process, a manufacturing apparatus for sending the structure 109 together with the optical fiber 105 is required, which makes it difficult and complicated to manufacture.

Therefore, the present invention has been proposed in view of the above-described circumstances, and an object of the present invention is to provide an optical fiber cable that can easily cut the jacket without complicating the manufacture.

One aspect of the present invention is an optical fiber cable in which a multi-core optical fiber is covered with a jacket made of a thermoplastic synthetic resin material, the major axis direction in the cross section of the jacket being the X-axis direction and the minor axis direction. When the Y-axis direction is adopted, an optical fiber having two or more cores in the X-axis direction and two or more cores in the Y-axis direction, and a tensile body disposed on both sides in the X-axis direction of the optical fiber in the cross section of the jacket In the outer cover, two pairs of notches are formed opposite to each other on both side surfaces in the Y-axis direction, and two straight lines connecting the notches facing each other in the cross section of the outer cover are: It is substantially parallel to the Y axis and passes through both end portions in the X axis direction of the optical fiber.

A support line portion having a built-in support line may be integrally formed on the outer jacket via a neck portion.

It is preferable that the notch has a shape in which the tearing force when tearing the jacket simultaneously at each notch on one side is not more than the breaking strength of the jacket piece.

According to the optical fiber cable according to the present invention, it is possible to easily take out all the optical fibers from the jacket without leaving the optical fibers in the jacket.

That is, the present invention can provide an optical fiber cable that can easily cut the outer cover without complicating the manufacture.

It is sectional drawing which shows the structure of the conventional optical fiber cable. It is sectional drawing which shows the structure of the conventional optical fiber cable. It is sectional drawing which shows the structure of the conventional optical fiber cable. It is sectional drawing which shows the structure of the optical fiber cable which concerns on one Embodiment of this invention. It is sectional drawing which shows the other example of a structure of the optical fiber cable which concerns on one Embodiment of this invention. It is sectional drawing which shows the further another example of a structure of the optical fiber cable which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 4 is a cross-sectional view showing the configuration of the optical fiber cable according to the present embodiment.

As shown in FIG. 4A, the optical fiber cable according to the present embodiment includes a main body 1a in which the optical fiber 1 is covered with an outer sheath (sheath) 3 made of a synthetic resin material, and a support wire 2 with an outer sheath 3. The support portion 2a is covered with The main body 1a and the support 2a are connected by a thin neck 4. The jacket 3 is made of a thermoplastic synthetic resin material. The support wire 2 is made of a metal wire or the like, is parallel to the optical fiber 1, and is enclosed in the outer jacket 3.

The optical fiber 1 of the present embodiment is, for example, an optical fiber or an optical fiber core. The optical fiber is an optical fiber in which an ultraviolet curable resin is coated on a bare optical fiber composed of a core and a clad. An optical fiber core is an optical fiber in which a resin such as a thermoplastic resin or an ultraviolet curable resin is coated on an optical fiber and the diameter thereof is larger than that of the optical fiber.

In this optical fiber cable, the optical fiber 1 has two or more cores in the X-axis direction and two cores in the Y-axis direction when the major axis direction in the cross section of the jacket 3 is the X-axis direction and the minor axis direction is the Y-axis direction. The above is an arrangement.

In the present embodiment, an 8-fiber (2 × 4) optical fiber 1 is used. In addition, the optical fiber 1 may have two rows of optical fibers arranged at the same position in the Y-axis direction as shown in FIG. 4A, or as shown in FIG. Two rows of optical fibers may be alternately (alternately) arranged in the Y-axis direction. The optical fiber 1 may be an optical fiber ribbon. The optical fiber ribbon is made of several optical fibers arranged in parallel and covered with an ultraviolet curable resin. The number of cores of the optical fiber 1 is not limited to eight, and may be, for example, 6 (2 × 3) or 10 (2 × 5).

As shown in FIG. 4 (a), the outer jacket 3 contains two strength members (tension members) 5 and 5 made of fiber-reinforced plastic together with the optical fiber 1. These

strength members

5 and 5 are arranged in parallel to the optical fiber 1. These

strength members

5 and 5 are disposed on both sides of the optical fiber 1 in the X-axis direction in the cross section of the outer jacket 3.

The outer jacket 3 is formed with two parallel groove-shaped notches A, B, A ′, B ′ facing each other across the optical fiber 1 on both side portions in the Y-axis direction. The jacket 3 can be easily torn at these notches A, B, A ′, B ′. By tearing the jacket 3, the optical fiber 1 can be pulled out and connected to the optical fiber of another optical fiber cable. As will be described later, each notch A, B, A ′, B ′ preferably has such a shape that the tearing force when tearing the jacket 3 simultaneously at each notch on one side is equal to or less than the breaking strength of the jacket piece 3. .

In the cross section of the jacket 3, two straight lines connecting the notches A and B and A ′ and B ′ facing each other are substantially parallel to the Y axis and both end portions in the X axis direction of the optical fiber 1. Through. Further, the tearing force Fna when tearing the outer cover 3 simultaneously at the notches A and A ′ on one side and the tearing force Fnb when simultaneously tearing at the notches B and B ′ on the other side are: The breaking strengths of Fja and Fjb are below. Here, since the tearing forces Fna and Fnb when tearing the jacket 3 simultaneously at the notches A, A ′, B and B ′ on one side are less than the breaking strengths Fja and Fjb of the jacket piece, The piece b does not break into upper and lower outer pieces b1 and b2 during tearing.

This optical fiber cable can easily take out all the optical fibers 1 from the jacket 3 without leaving the optical fiber 1 in the jacket 3 by the following procedure. Hereinafter, description will be made with reference to FIG.

First, at the end portion of the optical fiber cable, the outer cover is formed by using a nipper or the like from the two straight lines connecting the notches A, B and A ′, B ′ facing each other toward the longitudinal direction of the optical fiber cable. Make a cut in 3. In this state, the terminal portion of the jacket 3 is divided into three in the X-axis direction into a jacket piece c, a jacket piece d, and a jacket piece b. The optical fiber 1 is sandwiched between the center portions of the jacket pieces b.

Next, the outer cover piece c and the outer cover piece d on both ends in the X-axis direction in the terminal portion are pressed, and the cover piece b in the center is moved in the Y-axis direction as indicated by an arrow C in FIG. Torn. As a result, the jacket piece b is cut into the jacket piece b1 and the jacket piece b2 in the Y-axis direction starting from the notches A, A ′, B, and B ′, and the jacket piece c on both ends in the X-axis direction. And the outer casing piece d. Then, since the jacket 3 is divided into four, all the optical fibers 1 can be easily taken out.

FIG. 5 is a cross-sectional view showing another example of the configuration of the optical fiber cable according to the present embodiment.

For example, when the optical fiber 1 having 6 cores (2 × 3) is used, the distance between the notches A and B and the notches A ′ and B ′ is compared with the case of using 8 fibers (2 × 4). Becomes narrower, the cross-sectional areas of the jacket piece b1 and the jacket piece b2 become smaller, and the breaking strengths Fja and Fjb of the jacket piece b decrease. In this case, it is necessary to make the tearing forces Fna and Fnb when tearing the jacket 3 simultaneously at the notches A, A ′, B and B ′ on one side lower than the breaking strengths Fja and Fjb of the jacket piece. Therefore, it becomes necessary to shorten the distance between the bottom of each notch A, A ′, B, B ′ and the optical fiber 1. However, if this distance is too small, the notch portion is easily torn by a mechanical external force such as impact, twisting, or bending, and there is a possibility that the mechanical strength of the optical fiber cable is lowered. The distance between the bottom of each notch and the optical fiber 1 is preferably about 0.1 mm to 0.4 mm in consideration of the mechanical strength of the optical fiber cable and the ease of tearing of the notch portion.

Therefore, in this case, as shown in FIG. 5, the shape of the outer cover 3 of the main body 1a is such that the dimensions of the outer cover pieces b1 and b2 in the Y-axis direction are the Y axis of the outer cover piece c and the outer cover piece d. It is desirable not to decrease the breaking strengths Fja and Fjb of the outer cover piece as a shape in which both side surfaces in the Y-axis direction are bulged laterally so as to be larger than the dimension in the direction.

FIG. 6 is a cross-sectional view showing still another example of the configuration of the optical fiber cable according to the present embodiment.

In this optical fiber cable, if the optical fiber 1 has, for example, 12 cores (2 × 6), the number of optical fibers 1 in the X-axis direction increases, and the interval between the notches A and A ′ increases. Since the cross-sectional area of the jacket piece b1 and the jacket piece b2 is increased, the dimension of the jacket 3 in the Y-axis direction can be reduced.

As Example 1, an optical fiber cable having the configuration shown in FIG. 4B was prototyped, and the takeout property of the optical fiber 1 was verified. The optical fiber 1 is an optical fiber having 8 cores in which four optical fibers having a diameter of 0.25 mm are arranged in the X-axis direction and two fibers in the Y-axis direction. In the optical fiber 1, two rows of optical fibers are arranged alternately (alternately) in the Y-axis direction. The notches A, A ′, B, and B ′ are located on a straight line parallel to the Y axis that passes through both end portions of the optical fiber 1 in the X axis direction. As the strength member 5, an aramid FRP wire having a diameter of 0.5 mm was used. The material of the jacket 3 was flame retardant polyolefin.

The outer diameter of the main body 1a was about 6 mm × 2.5 mm. The tearing forces Fna and Fnb when tearing the jacket 3 simultaneously at the notches A, A ′, B and B ′ on one side were about 5N. The breaking strengths Fja and Fjb of the jacket pieces b1 and b2 were about 7N.

When the optical fiber 1 was taken out by the procedure described above, the whole core wire could be taken out easily. Further, assuming the work in the low temperature period and the high temperature period and verifying the workability of taking out the optical fiber 1 in an environment of −10 ° C. and + 40 ° C., the whole core wire could be easily taken out.

As Example 2, an optical fiber cable having a configuration shown in FIG. 5 was manufactured using a 6-fiber (2 × 3) optical fiber 1. In this optical fiber cable, both side surfaces in the Y-axis direction are side so that the dimensions in the Y-axis direction of the jacket pieces b1 and b2 are larger than the dimensions in the Y-axis direction of the jacket pieces c and d. The shape bulged to the side.

The tearing forces Fna and Fnb when the jacket 3 was torn simultaneously at the notches A, A ′, B and B ′ on one side were about 5N. The breaking strengths Fja and Fjb of the jacket pieces b1 and b2 were about 6.5N.

As Example 3, an optical fiber cable having the configuration shown in FIG. 6 was manufactured using a 12-fiber (2 × 6) optical fiber 1. If the optical fiber 1 has 12 cores (2 × 6), the number of optical fibers 1 in the X-axis direction increases, the distance between the notches A and A ′ increases, and the jacket piece b1 and the jacket piece b2 Therefore, the dimension of the outer jacket 3 in the Y-axis direction can be reduced. In this embodiment, the outer diameter of the main body 1a is about 6 mm × 2 mm.

The tearing forces Fna and Fnb when the jacket 3 was torn simultaneously at the notches A, A ′, B and B ′ on one side were about 5N. The breaking strengths Fja and Fjb of the jacket pieces b1 and b2 were about 9N.

The present invention is applied to an optical fiber cable in which an optical fiber is covered with a sheath.

Claims

An optical fiber cable in which a multi-core optical fiber is covered with a jacket made of a thermoplastic synthetic resin material,
An optical fiber in which two or more cores are arranged in the X-axis direction and two or more cores are arranged in the Y-axis direction when the major axis direction in the cross section of the jacket is the X-axis direction and the minor axis direction is the Y-axis direction;
In the transverse cross section of the jacket, comprising tension members disposed on both sides in the X-axis direction of the optical fiber,
The outer cover is formed with two pairs of notches facing each other on both side surfaces in the Y-axis direction, and two straight lines connecting the notches facing each other in the cross section of the outer cover are Y-axis And an optical fiber cable passing through both end portions of the optical fiber in the X-axis direction.
The optical fiber cable according to claim 1, wherein a support line portion including a support line is integrally formed on the outer jacket via a neck portion.
3. The light according to claim 1, wherein the notch has a shape in which a tearing force when simultaneously tearing the outer cover at each notch on one side is equal to or less than a breaking strength of the outer cover piece. Fiber cable.