JPH11149021A - Optical fiber cord and optical tape cord using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture an optical cord tape from optical fiber cords by specifying the radius of curvature of a high-tensile wire as the high-tensile wire of the cord tape to eliminate the generation of meandering caused by the meandering of the metallic high-tensile wires. SOLUTION: Relating to an optical fiber cord 5, metallic high-tensile wires 2... whose radiuses of curvature of meandering are >=200 mm are used. When wires are originally wires whose radiuses of curvature of meandering are >=200 mm, they may be used as high-tensile wires radiuses of curvature of meandering are >=200 mm as they are. Moreover, when wires are wires whose radiuses of curvature of meandering are <200 mm, meandering of the wires are reduced by passing them through a wire straightening device and wires whose radiuses of curvature are made >=200 mm, or are made preferably >=400 mm may be used. in the case of such an optical fiber code 5, since wires whose meandering are small are used as its high-tensile wires 2, it is hardly generated that the meandering appears in the optical fiber code 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cord and an optical tape cord which are suitable for high-density optical wiring in the office.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed an optical fiber cord having a structure shown in FIGS. 2 and 3 as an ultra-fine diameter and high strength optical fiber cord, and FIG. An optical tape cord having the structure shown is also proposed. In FIG. 2, reference numeral 1 denotes an optical fiber. This optical fiber 1 is a normal one having an outer diameter of 250 μm by providing a primary coating and a secondary coating on a bare optical fiber having an outer diameter of 125 μm. This optical fiber 1 has 3
Tensile strength members 3, 3 in which one set of tensile strength lines 2, 2, 2
Are attached vertically, and the strength members 3 are covered with a coating layer 4 and integrated to form an optical fiber cord 5.

In this optical fiber cord 5, the coating layer 4 has a rectangular cross-sectional shape, and two sets of strength members 3, 3 are provided at positions facing each other on the short side of the coating layer 4. Symmetrically arranged with the optical fiber 1 interposed therebetween,
A portion where 3 does not exist is disposed at a position facing the long side of the coating layer 4. The tensile strength wire 2 is made of a material having a high elastic modulus such as aramid fiber, PBO fiber, glass fiber, steel wire, or the like, and has a very small diameter of 20 to 50 μm. Further, for the coating layer 4, a thermoplastic resin, a thermosetting resin, an ultraviolet curable resin, or the like is used. Further, the optical fiber cord 5 has a cross-sectional dimension of usually 0.35 to 0.4 mm in the long side direction and 0.28 to 0.48 mm in the short side direction.
It is 0.25 mm, but is not limited to this range.

The optical fiber cord 5 shown in FIG.
On one side of the short side of the coating layer 4, two tensile strength lines 2, 2
Is different from the optical fiber cord 5 of the previous example in that a set of tensile strength members 3 composed of

FIG. 4 shows an example of the optical tape cord. The optical tape cord 7 of this example is a tape-shaped one in which eight single-core optical fiber cords 5, 5,... Shown in FIG. Each of the optical fiber cords 5 is arranged such that portions of the coating layer 4 where the tensile strength members 3 do not exist are adjacent to each other, that is, long sides of the coating layer 4 are adjacent to each other. With this arrangement, the tensile members 3, 3,... Of the optical fiber cords 5, 5,. The same material as the resin forming the coating layer 4 is used for the tape forming layer 6, but the Young's modulus of the resin forming the tape forming layer 6 is lower than the Young's modulus of the resin forming the coating layer 4. Preferably, each of the optical fiber cords 5, 5
The branching operation when branching to becomes easy.

In the tape cord 7 having such a structure, the tensile strength member 3 does not exist between the optical fiber wires 1 of the adjacent optical fiber cords 5 and only the coating layer 4 exists. By adjusting the thickness of 4, the width of the tape cord 7 can be made to match the width of a normal tape core wire, and can be made to match the interval between bare optical fibers. For this reason, the tape cord 7 and a normal tape core wire can be fusion-bonded together.

Further, as described above, since there is no strength member in the width direction of the tape cord 7, the dimension of the width itself can be reduced, and the density can be increased. Further, since the tensile members 3, 3,... Are arranged side by side on both surface sides, the mechanical strength is also sufficient. Further, in this structure, the tensile members 3 are provided only on both surfaces of the tape cord 7.
.. Exist, the tensile members 3, 3,... Can be easily cut and removed at once, and the taped layer 6 and the coating layer 4 can also be easily removed at once.

When the tape cord 7 is branched into the optical fiber cord 5, the cord 5 itself is also protected by the tensile members 3, 3,..., And there is no need to reinforce with a reinforcing tube or the like. It has excellent features such as being able to be used as it is as a branching cord of the heart, and is evaluated as satisfying the demand for high-density in-house optical wiring and the like.

2 and FIG. 3 are manufactured by arranging a plurality of tensile wires 2, 2,... On one optical fiber 1 as shown in FIG. The coating liquid is fed into a coating die while maintaining this arrangement. The coating liquid is used to apply a resin liquid to be the coating layer 4, and then sent to a curing device such as an ultraviolet irradiation device or a heating device. Is carried out by a method of curing.

The production of the optical tape cord 7 shown in FIG. 4 is performed by the same method as the conventional optical fiber ribbon. That is, a plurality of pre-manufactured optical fiber cords 5.
In a state where the portions where... Do not exist are arranged so as to be adjacent to each other, they are fed into the coating die from the wire entrance portion (nipple), where the resin liquid to be the taped layer 6 is applied, and then the wire exit portion. (Die), and is cured by heating or irradiating ultraviolet rays.

However, when the above-mentioned optical fiber cord 5 is manufactured, a Young's modulus of 7000 k
When a metal wire such as a steel wire or a brass wire having a high modulus of elasticity of not less than g / mm ² is used, the tensile strength wire 2 may have undulations such as winding habits. Swelling may occur in code 5. This is because many tensile strength lines 2, 2,... Are attached vertically to the optical fiber 1 as it is, and the ratio of the volume occupying the entire optical fiber cord 5 is large. Appears as it is.

Further, manufacturing the optical tape cord 7 using the undulating optical fiber cord 5 is as follows.
This is impossible because it cannot be fed into the coating die while maintaining the alignment. In order to solve such inconvenience, there is a method of removing the undulation by increasing the tension applied to the tensile wires 2, 2,... And the optical fiber 1 when the optical fiber cord 5 is manufactured. If the radius of curvature of the undulations is less than a certain value, it will not be possible to cope. The undulations of the tensile strength members 2, 2,... Differ greatly depending on the manufacturing rod, and the undulations of the optical fiber cord 5 largely depend on the undulations of the tensile strength lines 2, 2,.

[0013]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to prevent undulation in an optical fiber cord having the above-mentioned structure, and to prevent the production of an optical tape cord from being impossible due to the undulation of the optical fiber cord. Is to do.

[0014]

This problem is solved by using a tensile strength wire having a curvature radius of 200 mm or more, such as a metal tensile strength wire whose waviness is reduced by a straightening device.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The optical fiber cord according to the present invention uses a metal tensile strength wire 2, 2,... Such as a steel wire or a brass wire having an undulation curvature radius of 200 mm or more in the optical fiber cord 5 having the structure shown in FIG. 2 or FIG. It was what was. If the curvature radius of the undulation is 200 mm or more, the tensile strength line 2 having a curvature of 200 mm or more may be used as it is. If the radius of curvature is less than 200 mm, it is passed through a straightening device to reduce the swell and increase the radius of curvature to 200 mm or more, preferably 400 mm or more.
mm or more can be used.

FIG. 1 shows an example of the straightening device.
A plurality of straightening rolls 11 are arranged in multiple stages. The tensile strength wire 2 such as a steel wire sent out from the take-up roll 12 is run between the straightening rolls 11, 11,... As shown in the drawing. And the upper roll 1
The upper rolls 11, 11,... Are urged downward to apply a slight tensile tension to the tensile strength line 2 to forcibly plastically deform the wire, thereby reducing the undulation. I have. The tensile strength wires 2, 2... With reduced undulations are sent directly to the coating die together with the optical fiber 1 without being wound as they are, and are made into the optical fiber cord 5.

In the optical fiber cord 5, since the tensile wires 2, 2,... Having a small undulation are used, the undulation hardly appears on the optical fiber cord 5. Therefore, by using the optical fiber cord 5, the optical tape cord 7 can be manufactured without any problem. In addition, in the case of a tensile strength wire having a large undulation, it can be used by reducing the undulation by passing it through a straightening device, and the material can be used without waste.

The optical tape cord of the present invention is obtained by assembling a plurality of optical fiber cords 5, 5,... Manufactured using the undulating tensile wires 2, 2,. The portions of the coating layers 4 of the optical fiber cords 5, 5,... Where the tensile strength members 3 do not exist are arranged so as to be adjacent to each other and integrated by the taped layer 6, which is the same as that described above. It is.

A specific example will be described below. (Test example) As tensile strength line 2, diameter 20 μm, Young's modulus 7
The steel wire of 000kg / mm ^2, as the coating layer 4, the optical fiber cord 5 of the structure shown in FIG. 2 by using the ultraviolet ray curable resin
(Major axis: 0.35 mm, minor axis: 0.25 mm). At this time, the undulation generated in the optical fiber cord 5 was examined by using a steel wire in which the radius of curvature of the undulation was forcibly given to the values shown in Table 1, and the results are shown in Table 1. When the curvature radius of the undulation generated in the optical fiber cord 5 is 300 mm or more, it is marked as “○”.
Was evaluated. Further, an attempt was made to manufacture an optical tape cord using eight of these optical fiber cords 5, and the feasibility was examined. The results are shown in Table 1.

[0020]

[Table 1]

From the results shown in Table 1, if the curvature radius of the undulation of the steel wire as the tensile strength wire is 200 mm or more, the obtained optical fiber cord does not substantially exhibit undulation. It turns out that an optical tape cord can be manufactured favorably if used.

[0022]

As described above, in the optical fiber cord of the present invention, no undulation caused by the undulation of the metal tensile strength wire is generated, and the optical tape cord can be easily converted from this optical fiber cord. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a straightening device that can be used in the present invention.

FIG. 2 is a sectional view showing an example of an optical fiber cord according to the present invention.

FIG. 3 is a sectional view showing another example of the optical fiber cord according to the present invention.

FIG. 4 is a sectional view showing an example of the optical tape cord according to the present invention.

[Explanation of symbols]

1 ··· bare optical fiber, 2 ··· tensile strength wire, 4 ··· coating layer, 5 ··· optical fiber cord, 6, taped layer, 7 ···
Optical tape cord, 11 ... straightening roll

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunaga Kobayashi 1440, Mukurosaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant (72) Inventor Katsuyoshi Ishida 1,440, Musaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant (72) Inventor Keiji Ohashi 1440, Misaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant Co., Ltd. (72) Inventor Masao Tachikura Nippon Telegraph and Telephone Corporation, 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo, Japan (72) Inventor Kazu Takemoto 3-19-2 Nishi Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (3)

[Claims] An optical fiber is obtained by longitudinally adding a plurality of metal tensile wires to an optical fiber, covering and integrating a coating layer, and has a rectangular cross-sectional shape. An optical fiber cord in which a portion to be bent and a portion not to be formed are present, and the bending radius of the undulation is 200 mm as the tensile strength line.
An optical fiber cord using the above. 2. The optical fiber cord according to claim 1, wherein the tensile strength wire made of metal has a curvature radius of 200 mm or more by a straightening device. 3. An optical fiber according to claim 1, wherein the optical fiber cords according to claim 1 or 2 are arranged such that portions of the plurality of coating layers where no tensile strength lines are present are arranged adjacent to each other, and are covered and integrated with a tape-forming layer. Tape code.