JPH0392801A - Branching part for optical fiber tape - Google Patents

Abstract

PURPOSE:To fix a reinforcing body and a jacket to a coated optical fiber protection part and a single-fiber protection part respectively by applying the protection parts with the reinforcing body and jacket and their branching part with a heat-shrinkable tube. CONSTITUTION:The optical fiber tape 1 whose tip branches into single-fiber units is inserted into an optical fiber branching part A from an optical fiber fixation part 2, the respective branched single coated fibers 4 pass through the projection part 5, and then the optical fiber tape 1 is fixed to an optical fiber fixation part 2 with an adhesive as necessary. Then the optical fiber branching part A is applied with the reinforcing body 12 and jacket 13 to form a multi-branching pipe B. Further, the heat-shrinkable tube 18 is provided by covering both the branching part A and multi-branching tube B and then treated thermally. Consequently, the reinforcing body 12 and jacket 13 are fixed by securely adhering with the protection part. Further, when an adhesive layer 19 is used inside the heat-shrinkable tube 18, the reinforcing body and jacket can be fixed further strongly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the structure of a branching section for branching a tape-type optical fiber core into a single fiber at its terminal. More specifically, the present invention relates to a structure of a branch part of an optical fiber ribbon, which is closely fixed with a heat shrink tube. (Prior art) Conventionally, the structure of the branch part of an optical fiber ribbon is as follows:
For example, there is an example of an optical fiber cord as shown in Figure 7. That is, in the same figure, l is a tape core wire, 12 is a reinforcing body, 13 is an outer jacket, 4 is a single fiber wire, 15 is a branch protection plate, 1
Reference numeral 6 designates an injected hardened resin, 17 a reinforcing tube for reinforcing the entire tape core wire, and 7 an optical connector for connecting each single fiber wire.

Note that the tape core wire 1 is adhesively and temporarily fixed to the branch protection temporary 15. Also, the 1986 Institute of Electronics, Information and Communication Engineers 4PM National Conference B-
There is also an example of a branch part of an optical fiber as shown in 599r5 single-fiber conversion code J. (Problems to be Solved by the Invention) In the prior art, as shown in FIG.
3 and their joint points were covered with the reinforcing tube 17, and then resin 16 was poured into the reinforcing tube 17, and the tape core wire 1 and the single fiber wire 4 were directly fixed to the protection part with the resin 16. Therefore, the tape core wire 1 and the single core wire 4 were in bare contact with the resin 16, resulting in the following problems. ■ Stress is applied to the tape core wire 1 and single fiber wire 4 when the resin flows in and hardens, increasing light transmission loss. In addition, since the work of fixing the branch part of the tape core wire l to the protection plate 15 is delicate, if the alignment is not good, the transmission loss of light will increase, among other problems. There was a point.

Therefore, the present inventors proposed the previously published IWI (Japanese Patent Application No. 1983-
No. 40742), in order to solve the above-mentioned problems, as shown in FIGS. At the branch point where the tape core wire 1 is covered with the manifold tube B constituted by the protection section 5, the tape core wire protection section 6 and the single fiber protection section 5 are respectively covered with a reinforcing body 12 and an outer sheath 13, and further this branch After covering the reinforcing pipe 17 in the section, the reinforcing pipe 17 is
It was proposed that resin 16 be injected into the inside, harden, and adhere to each protective part. By adopting such a method of using the reinforcing tube 17, there is no danger that the tape fiber 1 and the single fiber fI4 will come into contact with the resin l6, and stress will not be applied to the optical fiber during the curing process of the resin etc. Even when the resin 16, etc. thermally expanded due to changes in environmental temperature during use, no stress was applied to the optical fiber, and an optical fiber with no increase in light transmission loss was obtained. However, even with this method, the problems that resin injection requires labor and time and that it takes a considerable amount of time to harden and solidify the resin remain unsolved.

(Means for Solving the Problems) As a result of intensive studies on means for solving the above problems, the inventors of the present invention have developed a heat-shrinkable tube, in particular a heat-shrinkable tube with an adhesive layer on the inner layer, instead of the reinforcing tube. The present invention was completed by using a tube to tightly adhere and fix the protective and reinforcing portions of the tape core wire and single core wire. That is, the present invention is: (1) A manifold tube consisting of a tape core fixing part or a tape core protector, a branch part accommodation space, and a single fiber protector is placed over a tape core whose tip end is branched. At the branch part of the optical fiber tape, the tape core protection part and the single fiber protection part are covered with a reinforcing body and an outer jacket, respectively, and the branch part is further covered with a heat shrinkable tube, so that the reinforcing body and the jacket are covered. (1) An optical fiber tape coated wire comprising: an adhesive layer provided on the inner layer of the heat-shrinkable tube; The branching part of the tree is also distinctive.

The present invention will be specifically explained based on the drawings.

FIG. 1 schematically shows the main parts of the branch part of the present invention. In the branch part, (a) shows the fixing part 2 of the tape core wire 1, the branch part accommodation space 3, and the part of the single fiber 4. In addition, (b) shows the manifold B which is placed horizontally from the protection part 5, and (b) shows another manifold which is made up of the protection part 6 of the tape core wire l, the branch part accommodation space 3, and the protection part 5 of the single fiber wire 4. Manifold B is shown. Figure 2 (a) schematically shows the main part of the manifold B in Figure 1 (a), and (b) and (C) are examples of multi-core wires with different tape core wire cross-sections. It shows.

FIG. 3 shows a top view (a) and a side view ('b) of a manifold of a different type from that shown in FIG. 2(a).

FIG. 4 schematically shows the main parts of manifold B in FIG. 1(b). Figure 5 shows the branch section (including manifold B) shown in Figures 1 to 4.
(a) covers the reinforcing tube 17, and O) covers the bento box type reinforcing box l8, injects the resin 16 into the reinforcing tube 17 or the bento box type reinforcing box l8, and hardens the main part of the branch part of the structure. An outline is shown.

FIG. 6 shows a branch portion of a structure in which a heat shrinkable tube (with an adhesive layer) is covered with a heat shrinkable tube (with an adhesive layer) and then heat-treated and shrunk according to the present invention, instead of injecting and curing the resin 16 in FIG. This shows an outline of the main parts. FIG. 7 schematically shows the main parts of the branch section of a conventional optical fiber cord. Basically, the optical fiber branch A and the manifold B
It is composed of. Even if the optical fiber branch A is fixed to the tape fiber fixing part 2 via the branch part accommodation space 3 as it is (see FIG. 1(a)), the optical fiber branch A can be accommodated in the branch part without being fixed. It is also possible to have a structure in which it is stored in space 3 (see Figure 1 (I)). In addition, when the tape core wire 1 is not fixed, it is preferable to provide a tape core protector 6 on the tape core wire 1 in order to avoid damage due to oscillation of the tape core wire ends (see FIG. 1(b). ), see Figure 4).

In addition, the tape fiber fixing section 2 is configured with a multi-core box 8 and a tube 9, as shown in FIG. 3, so that each of the multi-core wires can be protected and fixed. It can be fixed by

The manifold B is composed of a single-fiber protection section 5 that protects a large number of single-fiber wires, and a branch accommodation space 3. Moreover, as shown in FIG. 3, without providing the branch part accommodation space 3,
Each tube 9 may be placed directly in the multicore box 8.

Insert the tape fiber l whose tip is single-branched into the optical fiber branch 8 shown in FIG. 1(a) of A B from the tape fiber fixing portion 2 shown in FIGS. After passing the single fiber wire 4 through its protective portion 5, the tape core wire I is passed through the tape core wire fixing portion 2.
If necessary, fix with adhesive l1. Furthermore, in the optical fiber branch A shown in FIG. 1(b), it is also possible to store the tape core l directly in the branch housing space 3 without fixing it to the branch A as shown in FIG. It is.

Next, as shown in FIG. 6, in the optical fiber cord branching section, the optical fiber branching section A is covered with a reinforcing body 12 and a jacket 13, respectively, and a manifold pipe B is prepared.

Furthermore, a heat shrink tube l8 is placed so as to wrap both the branch part and the manifold, and heat treatment is performed to cover the reinforcing body 12.
And the outer sheath 13 is firmly attached and fixed to each protective part. In this case, if an adhesive layer 19 such as a real-melt adhesive is provided on the inner layer of the heat-shrinkable tube 18, more reliable adhesion and fixation can be ensured.

Note that, if necessary, the reinforcing tube 17 may be placed over the entire branch portion covered with the heat shrink tube 18.

In addition, this reinforcing pipe is not limited to a tubular one,
For example, a bento box-shaped reinforced box 17' shown in FIG. 5) may be used. When using the reinforcing tube 17, the heat treatment may be performed after covering the heat shrink tube 18 and further covering the reinforcing tube 17, or immediately after covering the heat shrink tube 17,
After that, the reinforcing tube 17 may be covered.

Tube The heat-shrinkable tube used in the present invention can be made of any thermoplastic, rubber, or a blend thereof; for example, ethylene-vinyl acetate copolymer, polyolefin, fluororesin, etc. , fluorine rubber, etc. The heat-shrinkable tube is generally produced by shaping these constituent base materials into a tube or sheet shape, then crosslinking as necessary, and then heat-stretching this in a predetermined direction, or inserting a mold core and expanding it. Then, it can be obtained by rapidly cooling and fixing.

If desired, various additives such as stabilizers, fillers, colorants, and antistatic agents may be incorporated into the structural base material of the heat-shrinkable tube used in the present invention.

Further, by providing an adhesive layer on the inner surface or both surfaces of the heat-shrinkable tube base material, the tight fixation of the reinforcing body 12 and the outer sheath 13 and the protective portion to the reinforcing tube 17 of the outer layer becomes more reliable. It is preferable to use a hot melt adhesive for this adhesive layer. True-melt adhesives that can be preferably used in the present invention include ethylene homo or cobolymer polyamides such as styrene and butadiene, polyesters, and butyl rubber. In addition, various additives such as tackifiers such as rosin and petroleum-based hydrocarbon resins, plasticizers such as paraffin waxes, and antioxidants can be added to the hot-melt adhesive base material. To prepare a heat shrink tube with an adhesive layer, a sheet of hot melt adhesive is applied to the reinforcing body 12 and the outer jacket l.
3. After lamination, heat-shrink tubing is coated or a heat-shrink tube is pre-integrated with an adhesive layer consisting of a heat-shrinkable base resin and a hot-melt adhesive by means such as extrusion lamination. Shrink tubing can be used. (Operations and Effects of the Invention) In the present invention, the optical fiber branching portion is an optical fiber branching portion that uses a heat shrink tube to fix the single fiber wire and the tape core wire to the reinforcing body and the outer jacket. It has the effect of finishing the work faster than the method of injecting it. In addition, if you use a heat-shrinkable tube with a (true melt type) adhesive layer on the inside, you can further strengthen the reinforcing body.
It has the effect of being able to be fixed to the outer covering.

[Brief explanation of drawings]

1 to 4 are schematic diagrams showing the structure of the main parts of the optical fiber branching section of the present invention. FIG. 5 is a schematic diagram showing the main parts of the optical fiber branch of the prior invention, which is covered with a reinforcing body and a jacket, and furthermore, a resin is injected between it and the reinforcing tube and hardened. FIG. 6 is a schematic diagram showing the structure of the main part of the optical fiber branching part of the present invention, in which both the manifold part A and the branching part B are covered with heat shrinkable tubes. FIG. 7 is a schematic diagram showing the structure of the main part of a conventional optical fiber branching section. DESCRIPTION OF SYMBOLS 1... Tape core wire, 2... Tape core wire fixing part, 3... Branch part accommodation space, 4... Single fiber wire, 5, 6... Single fiber wire, tape core wire Protection Department, 7...
Optical connector, 8... Porous box, 9... Tube, 10... Lid, l1... Adhesive layer, 12... Reinforcement body, l3... Outer cover (tape core wire and single core line), 16...
Resin, 1 7. 1 8 ・ 1 ・ 8B ・ 7″ ...Reinforcement tube, reinforcement box, ・Heat shrink tube, ・Adhesive layer, ・Optical fiber branch, ・Manifold, Figure 1 (α) (b) A Fig. 2 (a) Fig. 5 (α) (b) ￥6 Fig. 7

Claims (2)

[Claims] (1) A fixing part of the tape core wire or a protection part of the tape core wire,
At the branch part of the optical fiber ribbon, which is formed by covering the tape core whose tip end is covered with a manifold consisting of a branch part accommodation space and a single fiber protection part, a tape core protection part,
An optical fiber characterized in that the reinforcing body and the jacket are fixed to the respective protective parts by covering each of the single-fiber protection parts with a reinforcing body and a jacket, and further covering the branch part with a heat-shrinkable tube. Branch of tape core wire. (2) The branch part of the optical fiber tape core according to claim (1), characterized in that an adhesive layer is provided on the inner layer of the heat-shrinkable tube.