JPH0522208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for reinforcing a fusion splice of an optical fiber used in an optical transmission line.

(Background Art) Optical fibers are provided with a coating layer made of plastic or the like on the outside of the optical fibers in order to provide mechanical strength. Therefore, when connecting optical fibers, it is necessary to remove the coating layer from the end portions of the optical fibers. Therefore, after connection, it is necessary to re-reinforce the part by some method.

As this reinforcing method, there is a conventional method as illustrated in FIGS. 1 and 2. In FIG. 1, the connecting part of the optical fiber 1 is inserted into a tube 20 made of hot melt adhesive, and the rigid thin rod 2 is inserted into the tube 20.
1 are placed vertically, a heat-shrinkable reinforcing sleeve 4 is placed over their outer peripheries, and the sleeves are heated and shrunk to be reinforced.

In FIG. 2, two reinforcing plates 5, 5 each having a hot melt adhesive 7 pasted on one side of a substrate 6 made of a glass or ceramic plate are placed facing each other with the adhesive 7 side facing inside, and there is a gap between them. The connecting portion 3 of the optical fiber 1 is inserted, and the two reinforcing plates 5, 5 are put together and reinforced by heat and pressure bonding. 2 is a coating layer of the optical fiber.

All of these methods require a heat source and have drawbacks such as the need for several minutes for heating and cooling after heating. That is, the conventional method is not suitable for increasing the speed of optical fiber connection and for simplifying and downsizing the device.

This improves the efficiency of optical fiber connection work,
Development of new reinforcement methods is desired to simplify reinforcement devices and reduce costs.

(Disclosure of the Invention) The present invention has been made in view of the above-mentioned circumstances, and is capable of fusion splicing and splicing of optical fibers, which eliminates the above-mentioned drawbacks, speeds up the reinforcing work, and makes the reinforcing device smaller and simpler. This paper aims to provide a method for reinforcing the parts.

The present invention relates to a flat strip base material made of plastic foam having a pressure-sensitive adhesive layer on one side and a metal or plastic protective cover on the other side, or two or two reinforcing substrates connected together. An optical device characterized in that the adhesive layers are arranged so as to face each other, and a fusion splicing portion of an optical fiber is inserted between the adhesive layers, and then the opposing reinforcing substrates are pressed against each other and integrated. This is a method for reinforcing fiber fusion splices.

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 3A, 3B, and 3C are cross-sectional views for explaining the first embodiment of the present invention, in which FIG. 3A shows a cross section immediately before reinforcement, and FIGS.

To explain the structure of the reinforcing member 8, 9 is a substrate made of plastic foam, and has a pressure-sensitive adhesive layer 10 on one side. And the base material 9 is 2
The two adhesive layers 10 are fixed to the protective cover 12 with an adhesive so as to face each other. The protective cover 12 has an opening 13 on one side, and the opening 1
3 is provided with hooks 14 and 15, and when the protective cover 12 is closed, the hooks 14 and 15 are engaged and do not open. To explain the reinforcing method using this reinforcing member 8 in order, first, 1 part of the fusion spliced optical fiber and the covering layers 2 and 2 parts on both sides of the fusion spliced optical fiber are attached to the opening 13 while applying a certain tension to the optical fiber. Insert the protective cover 12 as shown in Figure A, close the protective cover 12 as shown in Figure B, and crimp it with a crimping tool prepared in advance. The reason for applying tension to the optical fiber here is to prevent the connecting portion from meandering within the reinforcing member 8.

Then, the pressure sensitive adhesive exerts adhesive force due to the pressure bonding effect, and the fusion bonded portion is fixed in the reinforcing member 8 and is reinforced by the protective cover 12. The material of the protective cover 12 is metal, and its main role is to improve strength and prevent local bending.

Note that the crimping tool used is adjusted in advance to provide a constant tightening pressure, and the reinforcing member 8 is also designed to provide an appropriate tightening pressure, so the tightening force of the reinforcing portion is always constant. becomes.

After the reinforcement, as shown in Figures B and C, the adhesive layer 10 and the base material 9 made of plastic foam are deformed along the optical fiber 1 and the coating layers 2 on both sides thereof, and are bonded to each other. .

FIGS. 4A and 4B are cross-sectional views for explaining the second embodiment of the present invention in the order of steps. In the figure, the same reference numerals as in FIG. 3 indicate the same parts. Second
The difference between this embodiment and the first embodiment is the protective cover.

The protective cover of the second embodiment consists of a pair of U-shaped protective covers 16 and 17 that have a fitting structure as shown in FIG. They touch each other to form a box-like shape, and are prevented from opening by being engaged by hooks 18 and 19 provided at the mating portions, respectively.

To explain the reinforcement procedure in this case, first, as shown in Figure A, the protective covers 16 and 17 are placed apart, and then one part of the fusion spliced optical fiber and two parts of the coating layer on both sides are With tension applied to the fiber, place it on the adhesive layer 10 on either side of the protective cover, and then fit the remaining protective cover in the pair until the hooks 18 and 19 engage, as shown in the diagram, and then attach both. Crimp. Regarding the mutual tightening pressure between the protective covers 16 and 17, when designing the reinforcing member 8, consideration was given so that the tightening pressure would be an appropriate constant, and after reinforcement, two adhesive layers were applied as in the case of the first embodiment. A reinforcing part is obtained in which the 10 are bonded to each other. Furthermore, the engagement of the hooks can prevent the pressure-sensitive adhesive from peeling off or deteriorating.

In the first and second embodiments, the case of a single-core optical fiber was explained, but the present invention is not limited to this, and the present invention is not limited to this. It is clear that the same applies to the case of lines.

(Effects of the Invention) The method for reinforcing the fusion spliced portion of an optical fiber according to the present invention described above has the following effects.

Since no heating is required during reinforcement, there is no need for a heater, and since a pressure-sensitive adhesive is used, there is no need to wait for the adhesive to harden, reducing work time.

In addition, since the adhesive layer is on the plastic foam, even if there is a step between the bare optical fiber section and the covering sections at both ends, the step can be absorbed by the foam cushion layer, making it particularly suitable for reinforcing members. There is no need to provide a step between the parts, and the connecting part can be set to the reinforcing member extremely easily. That is, if a step is required in the reinforcing member, mutual alignment is required when setting the connecting portion to the reinforcing member, but in this case, this is not necessary, and work efficiency is greatly improved. Furthermore, since the structure of the reinforcing member and the reinforcing method are simplified, costs can also be reduced.

Also, in terms of transmission characteristics, since there is a cushion layer made of foam, this cushion layer can absorb the expansion and contraction of the protective cover due to temperature changes, and has various advantages such as being extremely stable.

[Brief explanation of the drawing]

FIGS. 1 and 2 are perspective views for explaining examples of conventional optical fiber reinforcing methods, respectively. FIGS. 2A, 2B, and 4C and 4A and 4B are sectional views for explaining the first and second embodiments of the method of the present invention in the order of steps, respectively. DESCRIPTION OF SYMBOLS 1... Optical fiber, 2... Coating layer, 3... Connection part, 4... Heat-shrinkable reinforcing sleeve, 5... Reinforcement plate, 6... Substrate, 9... Base material, 7... Hot melt adhesive , 8... Reinforcement member, 10... Pressure sensitive adhesive layer, 12... Protective cover, 13... Opening, 1
4, 15, 18, 19... Futsuku, 16, 17...
... U-shaped protective cover, 20 ... tube made of hot melt adhesive, 21 ... rigid thin rod.

Claims (1)

[Scope of Claims] 1. A reinforcing substrate having a pressure-sensitive adhesive layer on one side of a flat base material made of plastic foam and a metal or plastic protective cover on the other side.
After arranging the two or two connected substrates so that the adhesive layers face each other and inserting the fusion splice of the optical fiber between the pressure sensitive adhesive layers, the opposing reinforcing substrates are connected to each other. The reinforcing substrate and the optical fiber fused are pressed together, and the step due to the difference in outer diameter between the bare optical fiber and the optical fiber having the coating layer in the optical fiber fusion spliced portion is absorbed and relaxed by the base material made of the plastic foam. A method for reinforcing an optical fiber fusion splice, which comprises integrating the spliced parts by fixing them with an adhesive. 2. When an optical fiber fusion splice is inserted between the mutually facing pressure-sensitive adhesive layers of the reinforcing substrates provided with interlocking hooks on both sides of the two protective covers, and the reinforcing substrates are pressed together, 2. The method of reinforcing an optical fiber fusion splice as claimed in claim 1, wherein the interlocking hooks are engaged with each other and the adhesive fixation of the pressure sensitive adhesive layer is maintained under a constant pressure.