JPH0519681B2 - - Google Patents

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 removed portion is formed by removing the coating layer from the ends of a pair of coated optical fibers, and the coating is removed. The fibers are cut to an appropriate length, and then the tips of the coated fibers (bare fibers) are heated by discharge heating, laser heating, etc., and are butted against each other to be fused and spliced.

FIG. 1 shows the optical fiber connection section fusion spliced as described above, and in the same figure, 1
A, 1B are a pair of coated optical fibers, 2A, 2B
are these coating layers, and 3A 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 the coating layers 2A and 2B are attached across the ends, thermosetting resin 6 is injected into the mold 4 through injection means such as a syringe 5, and the mold 4 is heated to inject the resin 6. It is hardened.

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. A burr 8 is generated, and this burr 8 causes the following problems.

In other words, the burr 8 is removed at the connection work site using scissors, razors, etc., but the removal work requires a lot of effort and time, and the diameter of the reinforcing coating layer 7 may be small. This may damage the same layer 7, or the burr 8 may not be removed sufficiently, and especially if the burr 8 is left behind, the coated optical fibers may not be assembled properly when they are later formed into a core or unit. For example, the wire may get stuck to 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 forms coat-removed portions by removing the coating layers from the ends of a pair of coated optical fibers, and after abutting the tips of these coat-removed portions against each other and fusion splicing, 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 of the coated removed part in the connected state, a die-shaped die that can be moved freely over the coated removed part in the connected state is provided on the outer periphery of one of the coated optical fibers. One coating device is provided, and after storing the uncured resin in the coating device, the coating removal section and the coating device in the connected state are moved relative to each other along the axial direction of the coating removal section. According to this method, an uncured resin is applied to the outer periphery of the uncoated portion in a connected state, and the uncured resin is cured to form a reinforcing coating layer.

(Example) Next, an example of the present invention will be described with reference to FIGS. 3 to 5.

In FIGS. 3 and 4, 1A and 1B are a pair of coated optical fibers, 2A and 2B are coating layers thereof, and 3
Reference numerals A and 3B indicate coating removal parts, and the tips of these coating removal parts 3A and 3B are fusion-spliced via known means, as in the case of FIG. 1.

In the present invention, when reinforcing the optical fiber connection part, first, the coating layers 2A, 2B of the coated optical fibers 1A, 1B are held by a pair of clamps 9A, 9B, and the coating removed parts 3A, 3B are held in the clamped state. Maintain tension with no slack.

Next, a dice-shaped coating device 10 is provided around the outer periphery of the one coated optical fiber 1B.

This coating machine 10 has a die part 11 and a resin storage part 12, and has a split structure that allows it to be disassembled into two or more parts.

Therefore, when the coater 10 is attached to the outer periphery of the coated optical fiber 1B as described above, the coating device 10 is applied to the outer periphery of the coated optical fiber 1B in a disassembled state, and these split mold parts are joined together.

The coating device 10 is arranged on an adjustment table (stage) 1 so that it can be adjusted in the front-back and left-right directions with respect to the coated optical fiber 1B having an axis in the vertical direction.
3, and the coating device 10 is set on the outer periphery of the coated optical fiber 1B as described above, so that the center of the die portion 11 and the axes of the coating removal portions 3A and 3B coincide with each other. It is centered via the adjustment table 13.

Further, the adjustment table 13 supporting the coating device 10 includes a guide 14 parallel to the coating removal parts 3A and 3B, a wire 15 connected to the coating device 10, and a drum 16A for winding and unwinding the wire 15. and sheave 16B, drum 16A
It is adapted to be moved in the axial direction of the coating removal parts 3A and 3B via a handle 17 etc. provided in the coating removal parts 3A and 3B.

In this state, the uncured (liquid) resin 6 is stored in the resin accommodating portion 12 of the coating device 10, and then, by operating the handle 17, the coating device 10 is moved from the coated optical fiber 1B side to the coated optical fiber 1A side. During the movement, the coating device 10 applies uncured resin 6 to the outer periphery of the coating removal portions 3A and 3B.

That is, in FIG. 4, an uncured reinforcing coating layer 7 is formed which undergoes a curing treatment.

The resin 6 forming this reinforcing coating layer 7 is made of silicone resin (including silicone rubber), thermosetting resin such as epoxy resin, urethane resin, unsaturated polyester resin, epoxy acrylate, urethane acrylate, etc. ) A suitable curable resin is adopted.

The uncured reinforcing coating layer 7 formed as described above is immediately cured by the curing means shown in FIG.

In FIG. 4, assuming that the resin 6 described above is photocurable, an ultraviolet lamp 19A and a reflector plate 19B are provided as a curing means 18 on both sides of the uncured reinforcing coating layer 7. The reinforcing coating layer 7 is cured by receiving the curing energy.

On the other hand, when the resin 6 is thermosetting, a heater such as an electric heater is provided as the curing means 18 around the uncured reinforcing coating layer 7, thereby curing the same layer 7.

In addition, if the outer diameter of the reinforcing coating layer 7 formed as described above is finished to be slightly smaller than the inner diameter of the die part 11, the above-mentioned steps may be repeated two or more times. The outer diameter of 7 is approximately the same as the outer diameter of the covering layers 2A and 2B.

Further, in the above-mentioned embodiment, the coating removal parts 3A and 3B
Although the coating device 10 was moved with the coating device 10 in a stationary state, conversely, even if the coating device 10 was kept in a stationary state and the coating removal parts 3A and 3B were moved in the axial direction, the same resin application as before could be performed. I can do it.

Coated optical fiber 1A, 1B with standard outer diameter
When forming the reinforcing coating layer 7 on the outer periphery of the connecting portion, approximately 0.2 ml (one dose) of uncured resin 6 may be stored in the resin storage portion 12 of the coating device 10.

FIG. 5 shows the reinforcing coating layer 7 formed as described above.

This reinforcing coating layer 7 has a smooth surface and does not generate burrs unlike the conventional method, and is therefore free from various problems caused by burrs.

(Effect of occurrence) As explained above, when using the method of the present invention, uncured resin is applied to the outer periphery of the coated removed part by the relative movement of the coated removed part in the connected state and the die-type coating machine, and the uncured resin is cured. By forming a reinforcing coating layer, not only can the optical fiber connection portion be reinforced, but the reinforcing coating layer can be finished with a smooth surface without burrs and with high accuracy in outer diameter.
Therefore, there is no need to remove burrs, and it is possible to reinforce the optical fiber connection part, which makes it easier to handle when unitizing the fibers.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the conventional method, Fig. 2 is a cross-sectional view of an optical fiber connection reinforced by the same method as above, and Figs. 3 and 4 are explanatory diagrams schematically showing one embodiment of the method of the present invention. , FIG. 5 is a cross-sectional view of an optical fiber connection reinforced by the above method. 1A, 1B...Coated optical fiber, 2A, 2B...
...Coating layer, 3A, 3B... Coating removal section, 6... Resin, 7... Reinforcement coating layer, 10... Coating device, 18... Curing means.

Claims (1)

[Scope of Claims] After removing the coating layer from the ends of a pair of coated optical fibers to form a coating removal section, abutting the tips of these coating removal sections against each other and fusion splicing, the connected state 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 coated optical fiber, the outer periphery of one of the coated optical fibers is provided with die-shaped coding that is movable across the coated removed part in the connected state. One container is provided, and after storing the uncured resin in the coating device, the coating remover and coating device in the above-mentioned connected state are connected.
By relatively moving the coating removed portion along the axial direction, an uncured resin is applied to the outer periphery of the coating removed portion in the connected state, and the uncured resin is cured to form a reinforcing coating layer. Reinforcement method. 2. The method for reinforcing an optical fiber connection portion according to claim 1, wherein the reinforcing coating layer is formed of either a photocurable resin or a thermosetting resin.