JPS60205507A - Method for reinforcing connected part of optical fiber - Google Patents

Abstract

PURPOSE:To form a reinforcing covering layer having a smooth surface free from burr on connected parts by coating and curing an uncured resin on the parts freed of their coverings by a spray means. CONSTITUTION:The outsides of parts 3A, 3B freed of their coverings are passed through a resin spraying region and a curing energy irradiating region by rotation. In the spraying region, an uncured resin 6 is sprayed on the outsides of the parts 3A, 3B from a sprayer 10. When a fixed amount of the resin is coated on the outsides of the parts 3A, 3B, the spraying is stopped once, and curing energy is irradiated on the coated resin 6 from a curing device 11 in the irradiating region to cure the resin 6. The sprayer 10 and the curing device 11 are placed at one end and the other end of a segment of a line which meets at right angles with the parts 3A, 3B.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for reinforcing optical fiber connections connected by fusion means.

(Prior Art) As is well known, when optical fibers are connected in the longitudinal direction by a fusion means, a coating removal section is formed by removing the coating layer from the end of a pair of coated optical fibers, and the coating is removed. After that, the tips of each coat-removed portion (bare fiber) are heated by discharge heating, laser heating, etc., and are abutted against each other and fused and spliced.

FIG. 1 shows the optical fiber splicing section fusion-spliced as described above. In the figure, IA and IB are a pair of coated optical fibers, 2A and 12B are their coating layers, and 3
A and 3B are coating removal parts.

The optical fiber connection part (including the part where the coating is removed) is generally reinforced with a coating means to ensure the strength after the coating is removed. After installing over the ends of the coating layers 2A and 2B,
For example, thermosetting resin 6 is injected into the mold 4 through injection means such as a ring 6, and the mold 4 is heated to harden the resin 6.

As a result, a reinforcing coating layer 7 made of the resin 6 is formed on the outer periphery of the optical fiber connection part as shown in FIG. Burrs 8 are generated, causing problems such as this burr 8 gaggi.

In other words, the burr 8 is removed using scissors, razors, etc. at the connection work site, but the removal work requires a lot of effort and time, and moreover, the reinforcing coating layer 7
Because the diameter of the burr is small, it may damage the same layer 7 or the burr 8 may not be removed sufficiently.In particular, if the burr 8 is left behind, it may be difficult to cover it when forming the core wire or unitizing it afterward. Optical fibers are not assembled properly, and for example, they get caught in the twisting die or break.

(Object of the Invention) In view of the above-mentioned problems, the present invention seeks to provide a method by which a reinforcing coating layer of an optical fiber connection portion can be formed on a smooth surface free from burrs.

(Structure of the Invention) The present invention involves removing the coating layers from the ends of a pair of coated optical fibers to form coat-removed portions, and fusion-splicing the tips of these coat-removed portions by abutting each other. After that, in the method for reinforcing an optical fiber connection part in which a reinforcing coating layer made of resin is formed around the outer periphery of the sheath removed part in the connected state, an uncured resin is applied to the outer periphery of the sheath removed part in the connected state via spray means. At the same time, the uncured resin is cured to form a reinforcing coating layer.

(Example) Next, an example of the present invention will be described based on FIGS. 3 and 4.

In FIG. 3, IA and IB are a pair of coated optical fibers, 2A and 2B are their coating layers, and 3A13B is a coating removal section.The tips of these coating removal sections 3A and 3B are as in the case of FIG. They are fusion spliced via known means.

In the present invention, when reinforcing the optical fiber connection part, the third
As shown, coated optical fiber IA.

The coating layers 2A and 2B of 1B are clamped by a pair of chucks 9A and 9B that can freely rotate forward and backward, and in the clamped state, the coating removal section 3A13B is held in a tensioned state without loosening.

On the line segment perpendicular to the coating removal parts 3A and 3B, there is a resin injector 1o on the negative side and a resin hardener 11 on the other side.
are placed respectively.

These injectors10. Coating removal section 3 via hardener 11
When forming a reinforcing coating layer on the outer periphery of As3B, the coating removal parts 3A and 3B are alternately rotated in forward and reverse directions by a pair of synchronously rotating chucks 9A and 9B.

At this time, the amount of forward rotation and the amount of reverse rotation are equal to each other, and each amount of rotation is at least one time or more, for example, about 2 to 4 times.

Due to the above rotation, the entire outer circumferential surface of the coating removal parts 3A and 3B passes through the resin spray area by the injector 10 and the curing energy irradiation area by the hardener 11, and the equal amount of forward and reverse rotation causes twisting to accumulate. disappears.

In this rotating state, the coating removal section 3 is removed from the injector 1o.
Uncured (liquid) resin 6 is sprayed toward the outer periphery of parts A and 3B, and a certain amount of resin 6 is sprayed onto the coating removal parts 3A and 3B.
Once the outer periphery of the resin 3B is coated, the resin spraying is immediately stopped and the resin 6 is irradiated with curing energy from the curing device 11 to harden the resin 6.

Thereafter, the resin application and its curing are repeated alternately until a predetermined outer diameter of the coating is achieved, thus forming the reinforcing coating layer 7 as shown in FIG. 4.

The surface of the reinforcing coating layer 7 thus formed is smooth and free from the occurrence of flashes that occur when using a mold, and therefore free from various problems caused by flashes.

In the present invention, the resin 6 for forming the reinforcing coating layer 7 is silicone resin (including silicone rubber), thermosetting resin such as epoxy resin, urethane resin, unsaturated polyester resin, epoxy acrylate, urethane acrylate, etc. When a light (ultraviolet) curable resin is used and the resin 6 is thermosetting, a heater such as an electric tanabata is used as the curing device 11, and when the resin 6 is photocurable, the ultraviolet rays A curing device 11 equipped with a lamp is used.

On the other hand, the injector 1o is a coating removal section 3A.

It is preferable that the resin injection area has a wide angle in the longitudinal direction of 3B and a narrow angle in the radial direction, and the nozzle is the coating removal part 3.
The injectors 11 may be scattered along the length of A and 3B.

Further, in the illustrated example, the injector 10 and the curing device 11 are arranged to face each other, but in order to prevent the resin 6 from the injector 10 from adhering to the curing device 11, the coating removal parts 3A, 3
The injector 10 and the curing device 11 may be disposed adjacent to each other within a fan-shaped corner within 90' with B as the center.

When the coating removal parts 3A and 3B are not rotated as described above, that is, when they are in a stationary state, the injector 1 in FIG.
0. By using the support plate 12 of the curing device 11 as a turntable and rotating the turntable alternately in forward and reverse directions, the same resin application as described above can be performed.

The injector 10 may be oscillated from the end of the covering layer 2A to the end of the covering layer 2B.

The method of the invention can be carried out either vertically (FIG. 3) or horizontally.

(Effects of the Invention) As explained above, when using the method of the present invention, an uncured resin is applied to the outer periphery of the uncoated part in a connected state via a spraying means, and is cured to form a reinforcing coating layer. Optical fiber connections that can not only be simply reinforced, but also have their reinforcing coating layer finished with a smooth surface without any burrs, eliminating the need for burr removal work and making them easier to handle when unitizing, etc. can be reinforced.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the conventional method, Fig. 2 is a sectional view of an optical fiber connection reinforced by the same method, Fig. 3 is an explanatory diagram schematically showing one embodiment of the method of the present invention, and Fig. 4 FIG. 2 is a cross-sectional view of an optical fiber connection reinforced by the same method as above. IA, IB...Coated optical fibers 2A, 2B...Coating layers 3A, 3B...Coating removal section 60.e.Resin 7...Reinforcement coating layer 9A, 9B. ... Chuck 10 ... Injector 11 ... Fist curing device Patent applicant representative Patent attorney Yoshio Saito 1st Figure f, i7・31Δ Figure 4

Claims (3)

[Claims] (1) After removing the coating layer from the ends of the pair of covered light 7 eyepers to form a coating removal part, and after butting the tips of these coating removal parts and fusion splicing, the coating removal part in the connected state In a method for reinforcing an optical fiber connection part in which a reinforcing coating layer made of resin is formed on the outer periphery, an uncured resin is applied to the outer periphery of the uncoated part in the connected state via a spray means, and the uncured resin is cured. A method for reinforcing an optical fiber connection part by forming a reinforcing coating layer. (2) A method for reinforcing an optical fiber connection portion according to claim 1, wherein a photocurable uncured resin is applied to the outer periphery of the uncoated portion in a connected state. (3) A method for reinforcing an optical fiber connection portion according to claim 1, wherein a thermosetting uncured resin is applied to the outer periphery of the uncoated portion in a connected state.