JPS612108A - Reinforcing method of welding part of optical fiber - Google Patents

Abstract

PURPOSE:To make reinforcing work efficient and to reduce the cost of the reinforcement by charging a housing having a resin tank with ultraviolet-ray hardening resin, embedding an optical fiber welding part in the resin and applying ultraviolet rays to harden the whole parts unitedly. CONSTITUTION:The housing 11 to be used for reinforcement is formed by metal or plastic and provided with the resin tank 12 of which inside is a reflecting part and a resin storing tank 14 on both the sides. The resin tank 12 is charged with the ultraviolet-ray hardening resin, the welding part 2a of the optical fiber is positioned and embedded in the resin and then ultraviolet rays are applied to the welding part to harden the whole parts unitedly. Consequently, the reinforcing work is made extremely easy and its hardening time is shortened down to about 20sec, so that the reinforcing work can be made efficient. Since the housing 11 is made of a metallic or plastic mold, the cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a method of reinforcing a fusion spliced portion of an optical fiber by using an ultraviolet curable resin and curing it by irradiating it with ultraviolet rays.

(Background of the invention) There are two types of optical fibers used in optical transmission lines: single-core type and multi-core type. The single-core type has a resin layer and a plastic layer on the optical fiber (hereinafter referred to as optical fiber core). In the multi-core type, a plurality of the above-mentioned optical fibers, for example, 5 to 10 cores, are arranged in a tape shape, and when fusion splicing the mechanical optical fibers, the coating at the ends of the optical fibers is removed. After fusion splicing, the exposed optical fiber connection portion must be reinforced by some method to provide mechanical strength.

1 and 2 are explanatory diagrams of conventional reinforcing methods, with FIG. 1 showing the case of a single-core optical fiber and FIG. 2 showing the case of a multi-core optical fiber μ.

In the case of the single-core optical fiber shown in Figure 1, heat shrink tube (3
) in which a steel core (4) and a hot melt adhesive tube ■ are housed. After pushing the adhesive tube (5) through the adhesive tube (5) in advance and fusion splicing the optical fiber (2) to obtain the connection part (2^), move the optical fiber core (1) and attach the above connection part (2^). ^
) at approximately the center of the hot melt adhesive tube ■. Figure (b) is a left front view of this state. After that, when the external heat-shrinkable tube '7 f3) is heated with a burner or the like and shrunk, the hot-melt adhesive tube (■) inside it melts, and the optical fiber core (1) and its connection part melt. As shown in Figure (c), it is embedded in the melted adhesive (54), solidified, and reinforced.

In this type of reinforcing method using a tube, it is necessary to insert the optical fiber core into the tube before fusion splicing the optical fiber, and if you forget to do this, you have to cut the spliced part and reconnect it. In the case of the multicore optical fiber shown in Figure 2, it is necessary to use two ceramic glass plates (6) with a hot melt adhesive layer ω on one side, as shown in Figure 2 (A). The surfaces of the hot-melt adhesive layers (■) are placed facing each other, and the optical fiber connection section of the multi-core optical fiber (1') is set between them. The melt adhesive layer (2) is melted, and the connecting portion of the multi-core optical fiber (1') is embedded in the adhesive layer (7α), solidified and reinforced, as shown in FIG.

In this method of reinforcing the joints of multicore optical fibers, the material cost is high because a ceramic glass plate is used as the substrate. .4IIm) has the drawback that it requires a lot of cost, effort, and time for processing and processes such as cutting, cutting, removing, cleaning, and baking and applying a layer of hot melt adhesive on one side. .

Furthermore, both single-core fibers and multi-core fibers require heating shrinkage or heat compression using a heater, so the former requires about 2 minutes and the latter about 3 minutes, making it unsuitable for high-speed reinforcement. It is.

For this reason, we aim to improve the efficiency of reinforcing methods for optical fiber fusion splices,
There was an urgent need to develop a new reinforcement method that would reduce costs and shorten reinforcement time.

(Disclosure of the Invention) This invention is based on the above-mentioned l! This was developed to solve the problem of Im, and provides a reinforcing method that provides good reinforcement of the optical fiber fusion part, improves the reinforcing workability, reduces costs, and speeds up the reinforcing process by shortening the reinforcing time. , the housing is made of metal or plastic and has a reflective part on the inner surface, and is equipped with a resin tank and resin reservoirs on both sides.The resin tank is filled with an ultraviolet curable resin, and the ultraviolet curable resin is irradiated with ultraviolet rays. It is characterized in that it is irradiated and cured integrally with the optical fiber fusion splicing section set in the housing.

The reinforcing method of the present invention will be explained in detail below with reference to the drawings.

Figure 3 shows the housing used in the method of the present invention (A and opening in the figure), the shield member (C in the figure), and the cover of the housing (
2) of the same figure both show perspective views.

Figure 3 (a) shows a housing GD used for reinforcing a single-core optical fiber, which is molded from metal or plastic.
Resin tank 03 in the center. Resin reservoirs 041 are provided on both sides thereof. For example, the resin tank Gb has a length [i0+u, a width of 3
It is open and U-shaped, about 3mm deep, and has a reflective part on its inner surface. If the housing 021 is made of metal, the inner reflective part of the inner surface will form the reflective part as it is, but if it is made of plastic, it should be pasted with aluminum foil or coated with metal. Rising treatment is performed to form a reflective part.

Also, after filling the resin tank 0shi with ultraviolet curable resin,
Until the reinforcement work is completed, it is sealed with a shield part 1fA061 as shown in FIG. 3(c).

The resin tank OΦ is provided on both sides of the resin tank Ob through a partition wall, and during reinforcement work, the shield member 0e is peeled off, the optical fiber fusion spliced part is set in the resin tank 021, and ultraviolet rays are irradiated. This is for receiving and curing the resin flowing out through the optical fiber guide groove q1 until the ultraviolet curing resin starts curing (about 10 seconds).

In addition, there is an optical fiber guide groove on the partition wall between the resin tank 0b and the resin reservoir 0Φ, which is designed so that once the optical fiber is set, vertical and linearity can be obtained and it can be positioned at a predetermined position in the resin tank Ob. has been done.

(II'), and the size is the same as the single-core type, but since the shape and outer diameter of the optical fiber in the multi-core type differs from the single-core type, the optical fiber guide groove (+3') The shape and size of the core are different from those of the single core type. Furthermore, in the case of a multi-core type, the optical fibers are flat, and the optical fiber guide groove (13')
is large, and the amount of resin that flows out is larger than that of the multi-core type.
Resin tank (14^) (+461) is provided in two stages, which is different from the single core type housing (JD) shown in Fig. 3 (1').

Figure 3) shows the cover of the housing H)C++'), which protects the reinforcing part after the ultraviolet curing resin has cured. Hook 08 is inserted in line with groove 0!3 of the housing. , 0 nails! Clamp and secure D to the bottom of the housing.

FIG. 4 is an explanatory diagram of the work of the reinforcing method of the present invention, in which (a) shows a state in which single-core optical fibers are fusion-spliced, (1) is an optical fiber core, and (■) is an optical fiber core wire. Optical fiber, (2a
) is its connection. UV curable resin in resin tank 02
) and sealed with the shield member OD
After setting D in the ultraviolet irradiation device (21) (see Fig. 4 (c)), remove the shield member Cθ and
A) While holding the optical fiber (1) and applying tension outward, position the fusion splicing part (2^) in the resin filled in the resin tank 021 of the housing OD. Fix it in the clamp. (See the opening in FIG. 4) During this time, the resin flows out from the resin tank surface through the gap between the optical fiber guide groove a3 and the optical fiber core (1), but a small amount of resin is received in the resin reservoir tank 044.

In this state, as shown in FIG. 4(c), ultraviolet rays are irradiated from above by an ultraviolet irradiation device (21) to completely cure the ultraviolet irradiation type resin.

The resin cures in about 20 seconds when using an ultraviolet lamp with an output of 50 mW. This curing time is due to the effect of the reflective section provided on the inner surface of the resin; in the case without the reflective section, it would have taken 2 to 3 times as much time even with the same output.

The above explained the reinforcing force method for single-core optical fibers, but when reinforcing multi-core optical fibers, the reinforcing method is the same just by replacing the housing, and the workability and reinforcing time are almost the same as for the small-core type. Nothing has changed.

In addition, although the above explanation is based on the case where the housing is pre-filled with ultraviolet curable resin, if a housing is not filled with resin and the optical fiber fusion spliced part is inserted into the housing seven times during reinforcement, the resin is inserted into the tube. Alternatively, injection and filling may be performed using a jig such as a syringe.

(Effects of the Invention) According to the above-described reinforcing method of the present invention, the housing is filled with ultraviolet curable resin and cured by ultraviolet irradiation, which improves work efficiency. This has the advantage of shortening the curing time and significantly shortening the reinforcing time. Furthermore, since the housing can be easily obtained by molding metal or plastic, it does not require special processing unlike conventional multicore reinforcing members.
You can save effort, time, and cost.

[Brief explanation of the drawing]

Both Fig. 1 and Fig. 2 are explanatory diagrams of the conventional reinforcing method for optical fiber fusion splicing parts.
FIG. 2 shows the case of a multicore optical fiber. Figure 3 shows the housing (A and mouth in the figure), shield member (C in the figure), and cover (2 in the figure) used in the reinforcing method of the present invention.
Both are perspective views, and FIG. 4 is an explanatory diagram of the reinforcing method of the present invention. FIG. 4 (a) is a fusion-spliced optical fiber, and FIG. , same figure (c)
FIG. 2 is a cross-sectional view showing a state of ultraviolet irradiation. 1... Optical fiber core wire, 2... Optical fiber, 2a.
...Optical fiber fusion splicing part, II, I+'...Reinforcement housing, +2...Resin tank, 13.13'...Optical fiber guide groove, 14.146L, 14 people...Resin tank , 16... Shield member, 17... Cover. Official 1 Official 4 (A) (B) (C)

Claims (3)

[Claims] (1) Filling the resin tank of a housing made of metal or plastic with a reflective part on the inner surface and a resin tank and resin reservoirs on both sides following the resin tank, filling the resin tank with an ultraviolet curable resin; A method for reinforcing an optical fiber fusion splice, comprising: irradiating it with ultraviolet rays to harden it integrally with the optical fiber fusion splice set in the housing. (2) The method for reinforcing an optical fiber fusion splicing section according to claim 1, wherein the housing is molded from plastic and has a reflective section made of metal foil on the inner surface. (3) Claim 1, characterized in that the housing is filled with an ultraviolet curable resin and sealed with an ultraviolet blocking shielding member, and reinforcement is performed after removing the shielding member before use. The method for reinforcing the optical fiber fusion splicing section described above.