JPH03123306A - Branching part for optical fiber cord with connector - Google Patents

Abstract

PURPOSE:To improve the tensile strength of a branching part and the handleability of a protective tube by forming integrally the protective tube with a contraction tube, and simultaneously, fixing a Kepler. CONSTITUTION:On a protective tube 10, a Kepler 13 is folded, a Kepler 14 is attached vertically thereon, and the Keplers 13, 14 are covered with a thermal contraction tube 15. The tip part of an optical fiber cord 5 is covered with a thermal contraction tube 16, a transparent teflon pipe 17 is fitted so as to step over both contraction tubes 15, 16, and also, a transparent thermal contraction tube 18 is placed thereon. In such a manner, by forming integrally the protective tube 10 by the thermal expansion tube 18, and simultaneously, fixing a Kepler 3, the tensile strength of a branching part and the handleability of the protective tube 10 are improved. Therefore, the branching part can be miniaturized and the cost can be reduced, and also, the reliability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a branch section of an optical fiber cord with a connector.

[Prior Art] With the increase in the density of optical fiber cables, the demand for optical tape cables using optical fiber tape cores is increasing. When this optical tape cable is connected to a device using a termination box, an optical fiber cord with a connect connector has conventionally been used. An optical fiber cord accommodates a single core of optical fiber, and an optical fiber cable has a structure in which a single core of optical fiber is housed in a multi-core plastic spacer or the like. Optical fiber ribbon is made by covering a plurality of optical fibers all at once, and when attaching a connector, it is necessary to separate each fiber and optically encode it.

However, if this work is done inside the termination box and each fiber is optically coded, a huge number of connections must be housed inside the termination box, and the huge number of optical cords must be separated and connected to the connectors to the equipment. Need to connect. To solve this problem, each fiber of the optical fiber tape is spliced to form an optical code, and each fiber is separated and attached with a connector before entering the equipment, thereby reducing the number of splices and optical codes. is used.

Figures 3, 4, and 5 show an example of a two-core optical fiber cord, and are a cross-sectional view of the optical fiber cord, a vertical cross-sectional view of the branch part of the optical fiber cord with a connector, and a cross-sectional view of the protective tube, respectively. Show the diagram.

In these figures, 1a is an optical fiber, 1b is an ultraviolet curable resin, and 1 is an optical fiber las ultraviolet curable resin 1.
2 is an optical fiber cord formed by the two-core optical fiber strand 1 and an ultraviolet curable resin 1b; 3 is an optical fiber cord formed from the optical fiber cord 2 made of high-tensile fiber; Kevlar (trade name of DuPont), 4 is a sheath for sheathing Kevlar 3, 5 is an optical fiber cord formed by these parts, 6 is a sleeve for sheathing the terminal end of optical fiber cord 5, 7 is optical fiber cord 5 and one end of the sleeve 6, 8 is a fixture for fixing the Kevlar 3 together, 9 is an end plate fixed to the other end of the sleeve 6, and 10 is a tube for passing the optical fiber 1 through. 10a is a protective tube that protects the optical fiber 1
10b is nylon vibe 1
10c is a sheath that covers Kevlar 10b, 11 is an optical connector attached to the distal end side of the protective tube 10, and 12 is a fixture for fixing the protective tube 10 to the end plate 9.

In FIGS. 3 to 5, an optical fiber 1 is formed by coating the outer periphery of an optical fiber 1a with an ultraviolet curable resin 1b.
An optical fiber cord core 2 is formed by coating the outer periphery of the two cores with an ultraviolet curable resin 1b. Next, a Kevlar 3 is longitudinally attached to the outer periphery of the optical fiber cord core 2 as a tension member and covered with a sheath 4 to form an optical fiber cord 5.

When attaching the optical connector 11 to the optical fiber cord 5, the sheath 4 at the end of the optical fiber cord 5 is removed to expose the Kevlar 3 and the optical fiber cord core 2, and the optical fiber cord core 2 is separated one by one. Then, the optical fiber 1 is made into a state. The part where the optical fiber cord core 2 is separated into the optical fiber strands 1 is covered with a sleeve 6 to protect it. The sleeve 6 is fixed to the sheath 4 of the optical fiber cord 5 with a heat shrink tube 7. Kevlar 3 is gathered together with fixing bracket 8
Fix by caulking, gluing, etc. The fixture 8 is fixed to an end plate 9 fixed to the sleeve 6.

On the other hand, the optical fiber 1 is passed through a hole provided in the end plate 9, pulled out from the sleeve 6, and inserted into the protective tube 10. One end of the protective tube 10 is fixed to a protective tube fixing fitting 12, and an optical connector 11 is attached to the other end. In this way, the optical fiber 1 is transferred to the protective tube 1.
It is inserted into the nylon vibrator 10a of No. 0 and protected from external force (Fig. 5).

[Problems to be Solved by the Invention] Although the branch portion of the optical fiber cord is formed as described above, some problems still remain in this case. That is, there are many parts that make up the branch, and it takes a lot of time to assemble. Further, since a space is required to fix the high-tensile fiber Kevlar, the space and weight of the branching portion are increased, making handling inconvenient. Furthermore, since the arrangement of the optical fibers cannot be observed during assembly, even if twisting or bending occurs, it cannot be corrected, which tends to reduce reliability.

It is an object of the present invention to solve the above-mentioned drawbacks of the prior art, to reduce the size and cost of the branch part, to significantly improve assembly workability, and to improve reliability of the branch part of an optical fiber tape cord with a connector. Our goal is to provide the following.

[Means for Solving the Problems] The present invention provides a coded optical fiber by coating a multi-core optical fiber core with a resin and then covering it with a sheath. A protective tube that is composed of a fiber cord, an insulating pipe, a high-tensile fiber, and a sheath and protects the optical fiber wire passing through it from external forces, and an optical connector that is attached to the tip side of the protective tube and connects to an external device. , at a branching part of the optical fiber cord with a connector that connects and fixes the optical fiber cord and the protective tube and branches the light transmitted through the optical fiber cord through the connector, the high-tensile fiber in the protective tube is placed on the protective tube. The high tensile strength fibers in the optical fiber tape cord are folded back at a certain length, and the high tensile strength fibers in the optical fiber tape cord are vertically attached on top of the high tensile strength fibers. A heat-shrinkable tube to be crimped is covered, and a transparent plastic pipe is placed outside the heat-shrinkable tube and the tip of the optical fiber cord so as to span both, and the optical fiber is shrunk by heating on the outside of the plastic pipe. The branch part is covered with a transparent heat-shrinkable tube that integrally fixes the cord and protection tube together via a plastic pipe, which reduces the number of parts, makes assembly easier, and improves reliability. In this way, we aim to achieve our goals.

[Function] In the branching part of the optical fiber cord with connector of the present invention, after arranging the optical fiber cord and the protective tube so as to face each other, the Kevlar of the protective tube is folded back and arranged on the sheath of the protective tube, and then the optical fiber The Kevlar cord is stacked vertically on top of this, and the multiple protective tubes constructed in this way are wrapped together in a heat shrink tube.
Furthermore, the tip of the optical fiber cord is also surrounded by a heat shrink tube, both tubes are heated and shrunk to fix them, and then one optical fiber is passed through each protective tube, and then straddled over the side heat shrink tube. The optical fiber cord and protective tube are covered with a transparent Teflon tube, which is then covered with a transparent heat shrink tube so that the optical fiber cord and protective tube can be covered with Kevlar, heat shrink tube, Teflon pipe, and the outermost heat shrink tube. This makes assembly work easier, and the branch part can be firmly fixed.Furthermore, since the internal situation can be observed from the outside, reliability can be greatly improved. can.

[Examples] Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the branch part of the optical fiber cord with connector of the present invention, and FIGS. 2(a) to (e) are the first
This is an explanatory diagram showing the assembly work process of the branch section shown in the figure, and the same parts as in FIGS. 3 to 5 are given the same reference numerals.

In both figures, 13 is Kepra folded over the protective tube 10, 14 is Kevlar attached vertically thereon, 15 is a heat shrink tube placed over both Kevlar 13 and 14,
16 is a heat shrink tube placed over the tip of the optical fiber cord 5; 17 is a transparent Teflon pipe fitted across the side heat shrink tubes 15 and 16; and 18 is a transparent heat shrink tube placed over it. It's shrink tubing.

Hereinafter, the work process for assembling the branch section will be explained based on FIG. 2.

(L) Optical fiber cord5. The terminal portion on the optical connector 11 side is peeled off to a required length to expose the twin-core optical fiber core 2 and Kevlar 3. Next, the two-core optical fiber core 2 is separated into individual optical fibers 1. Further, the Kevlar 3 is cut to a length necessary for fixing (FIG. 2(a)).

(2) Prepare two optical fiber strands 1 separated by -6 and two protective tubes 1O of the required length, and sheath 10c at one end.
is peeled off to a required length to expose the nylon pipe 10a and Kevlar 10b. The nylon vibrator 10a and Kevlar 10b are cut into required lengths (FIG. 2(b)).

(3) The optical fiber cord 5 and the protective tube 10 are made to face each other at an arbitrary interval, and the Kevlar 1 of the protective tube 10 is
0b is evenly folded around the outer periphery of the sheath 10c to form a folded part 1.
3, and the Kevlar 3 of the optical fiber cord 5 is evenly longitudinally attached to the outer periphery of the sheath 10c of the protective tube 10 to form a longitudinally attached portion 14 (FIG. 2(C)).

(4) Optical fiber cord 5 and protective tube 1 in advance
Heat shrink tubes 16 and 15 passed through the two tubes of
(with adhesive on the inner surface) is placed in a predetermined position, and the respective heat-shrinkable tubes 15 and 16 are heat-shrinked to fix the two Kevlar 3 and 10b1 protective tubes 10 together. In this case, the heat shrink tube 1 on the optical fiber cord 5 side
6 serves as a dummy for matching the outer diameter with the opposing protective tube 10. After this, optical fiber strand 1
are inserted one core at a time into the nylon vibrator 10a of the protective tube 10 (FIG. 2(d)).

(5) Pass the Teflon pipe 17 through it in advance (D)
It is placed across the heat-shrinkable tubes 15 and 16 covered in step (Fig. 2(e)).

(6) The heat-shrinkable tube 18 (with adhesive inside), which has been passed through in advance, is placed on top of the Teflon pipe 17 and heated and shrunk. The length of the heat shrink tube 18 is Teflon pipe 1
7 and approximately the same length as the end portions of the heat shrink tubes 15 and 16.

With the above steps, the branch portion is completed (FIG. 1), and then the connector 11 is attached to the end portion of the protective tube 10 to complete the optical fiber cord with connector.

In addition, although the above-mentioned embodiment explained the case where the optical fiber cord cores are two cores, this can also be applied to the case where there are multiple cores. In addition, although Teflon pipes are used to protect the branching parts, any material can be used as long as the vibrator is heat resistant and the inside can be seen visually. Moreover, as a method of fixing Kevlar, it was fixed all at once on the protection tube side and fixed with a heat shrink tube, but it may be fixed all at once on the optical fiber cord side. In this case, good results can be obtained by covering the protective tubes with a heat-shrinkable tube for fixing the multiple protective tubes together.

〔Effect of the invention〕

As described above, according to the present invention, the following effects can be obtained.

(1) By integrating the protective tube with a heat-shrinkable tube and fixing Kevlar at the same time, it is possible to improve the practical tensile strength of the branch and the handling of the protective tube.

(2) Since the inside of the Teflon pipe that protects the branch portion can be visually inspected, abnormalities such as twisting and bending of the optical fiber strands during assembly can be detected. In addition, the Teflon pipe prevents the effects of heat during heat shrinkage of the heat shrinkable tube that covers the outer periphery of the Teflon pipe, thereby maintaining the characteristics of the optical fiber.

(3) Reliability can be improved by making the branch part smaller and cheaper.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of the branching part of the optical fiber cord with connector of the present invention, Fig. 2 is an explanatory diagram of the assembly work process of the branching part shown in Fig. 1, and Fig. 3 is the optical fiber cord. FIG. 4 is an explanatory view of a conventional optical fiber cord with a connector, and FIG. 5 is a cross-sectional view of the protective tube shown in FIG. 4. 1: Optical fiber wire, 1a: Optical fiber, 1b: Ultraviolet curable resin, 2: Optical fiber cord core, 3: Kevlar, 4: Sheath, 5: Optical fiber cord, 10: Protective tube, 10a: Nylon pipe , 10b: Kevlar, 10C: Sheath, 11: Optical connector, 13: Folded part of Kevlar 10b, 14: Vertical support part of Kevlar 3, 15.16: Heat shrink tube, 17: Teflon vibe, 18: Heat shrink tube. Party item tC) Boar day item 1: 77 (ba (latitude 3, 1ob: kebura 5: e7)
Eye code 10: Hofi ÷ Knee 1 15, 16, 18
``De 1'' False Keyup himself; Thea 0〉〉] Desired Eve Tomb ■ No. 11: 9th J, 77

Claims (1)

[Claims] 1. Optical fiber cord made by coating multi-core optical fiber strands with resin, coated with high-tensile fibers and sheath, and coded by sheathing; insulated pipe;
The optical fiber cord is provided with a protective tube configured of high-tensile fibers and a sheath to protect the penetrating optical fiber from external forces, and an optical connector attached to the distal end side of the protective tube to connect to an external device. At the branching part of the optical fiber cord with a connector that is connected and fixed to the protective tube and branches the light transmitted through the optical fiber cord through the optical connector, the high-tensile fiber in the protective tube is fixed on the protective tube. The high tensile strength fibers in the optical fiber cord are longitudinally attached on top of the high tensile strength fibers, and the high tensile strength fibers are shrunk by heating, and the high tensile strength fibers and the high tensile strength fibers are A transparent plastic pipe is placed outside the heat-shrinkable tube and the tip of the optical fiber cord so as to straddle both. 1. A branch part of an optical fiber cord with a connector, characterized in that the branch part of an optical fiber cord with a connector is covered with a transparent heat shrinkable tube which is shrunk to integrally fix the optical fiber cord and the protection tube via the plastic pipe.