JPH0140961B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a method for coating an optical fiber fusion splice.

(b) Prior Art When optical fibers are connected, the coating layer that protects the optical fibers is peeled off, and the optical fibers are butted against each other and fusion spliced. Therefore, since the glass portion of the optical fiber is exposed at the connection portion, it is necessary to cover, protect and reinforce this portion.
For example, when connecting optical fibers used in optical submarine cables, etc., the outer diameter of the sheath covering the splicing part must be approximately the same as the outer diameter of the sheathing layer, as the cable is formed after fusion splicing. As shown in FIG. 3, the coating is formed by a molding method in which the connecting portion 4 of the optical fiber 3 is sandwiched between an upper mold 1 and a lower mold 2, and resin is injected from the resin injection port 5 and cured. be done. In this case, it is necessary to sequentially insert the optical fiber into the mold, harden it, and remove it from the mold, which takes time and effort, and furthermore, when the optical fiber is inserted into the mold, it comes into contact with the mold, etc. The drawback was that it could cause severe damage.

(C) Purpose The purpose of the present invention is to provide a method for coating an optical fiber fusion spliced part in a perfect circle easily and in a short time without damaging it.

(d) Structure The method of the present invention involves bringing a split die into contact with the surrounding area of the optical fiber coating near the fusion spliced part from which the coating layer has been peeled off, filling the split die with an ultraviolet curable resin, The split die filled with this ultraviolet curable resin is moved relatively in the axial direction of the optical fiber to apply the ultraviolet curable resin onto the fusion spliced part from which the coating layer has been peeled off, and the resin is exposed to ultraviolet rays. It is cured by irradiation.

(E) Embodiment FIG. 1 shows an example of a coating forming device, and the coating forming device 6 has a pair of movable tables 8 and 9 held by a substrate 7 so as to move from side to side. By operating the vernier knobs 10 and 11, it can be slightly moved left and right. These movable tables 8, 9 are equipped with a pair of split dies 12, 13 for applying a coating material such as epoxy resin, and ultraviolet spot light sources 14, 15.
Note that the split dice 12 and 13 are mounted on movable tables 8 and 9.
L-shaped plate-shaped support parts 33 and 44 are fixed to the front surface of the support parts 33 and 44 with screws or adhesive, and a plate-shaped base part 55 is fixed to the bottom of these support parts 33 and 44 with screws or adhesive. , 66, and semi-funnel-shaped recesses 77, 88 are formed in the inner walls of the end portions of the bases 55, 66.
8 are aligned to form a funnel-shaped die. Note that the inner diameter of this die is set to approximately match the outer diameter of the optical fiber coating layer. Further, the substrate 7 is moved up and down along the optical fiber by a motor (not shown).

As shown in FIG.
19. Next, a coating forming device 6 as shown in FIG.
11 to move the movable tables 8, 9, and align the semi-funnel-shaped recesses 77, 88 of the split dies 12, 13 to form a funnel-shaped die. As described above, the inner diameter of the die is made to substantially match the outer diameter of the optical fiber coating layer, so that the inner surface of the die is in contact with the periphery of the coating layer of the optical fiber 16 below. Next, this die is filled with ultraviolet curable resin 23. The substrate 7 of the coating former 6 is then moved upwards, so that the viscosity and surface tension of the resin 23 causes the resin 23 to be exposed on the surfaces of the optical fibers 16, 17, particularly at the connection portion 22 of the glass fiber 20. , 21. At this time, the coating forming device 6
As a whole moves upward, the spot light sources 14 and 15 also move upward together with the splitting dies 12 and 13 at the same time as the splitting dies 12 and 13, a little later than these.
The resin 23 attached to the surface of the glass fiber 2 is hardened by ultraviolet irradiation before flowing down, and the glass fiber 2
A good coating is formed over 0 and 21 to protect and reinforce them.

As described above, since the ultraviolet curing resin 23 is applied and cured at the same time, the work is simple and the work time is short. In addition, resin 23
Since coating and curing can be performed while observing, it is possible to pay attention to whether or not the splitting dies 12, 13, etc. have come into contact with the glass fibers 20, 21. damage and strength deterioration caused by this can be prevented. Also split dice 1
2 and 13 are used, so it can be coated in a perfect circle.

(F) Effects The method of coating an optical fiber connection part according to the present invention involves applying an ultraviolet curable resin to the optical fiber coating part near the connection part using a split die, and then irradiating this resin with ultraviolet rays to harden it. This method allows the coating to be made into a perfect circle, and the work is simple. Moreover, the work time can be shortened, and it is also possible to observe the condition of the optical fiber during work. Since it is easy to use, it is also easy to prevent damage to the optical fiber wire.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing an example of a coating forming device according to the present invention, FIG. 2 is a schematic front view for explaining a method for covering a connection part, and FIG. 3 is a schematic diagram of a conventional example. be. 16, 17...optical fiber, 22...connection part,
6... Coating former, 7... Substrate, 8, 9... Moving table, 10, 11... Vernier knob, 12, 13
...split dice, 14,15...spot light source,
20, 21...Glass fiber, 23...Ultraviolet curing resin, 77, 88...Semi-funnel-shaped recess.

Claims (1)

[Claims] 1. A split die is brought into contact with the area surrounding the optical fiber coating near the fusion spliced part from which the coating layer has been peeled off, and an ultraviolet curable resin is filled into the split die. A splitting die is moved relatively in the axial direction of the optical fiber to apply an ultraviolet curable resin on the fusion spliced part from which the coating layer has been peeled off, and the resin is cured by irradiating ultraviolet rays. A method for coating optical fiber fusion splices.