JP2575466B2 - Optical fiber coating equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical fiber coating apparatus used for coating the surface of an optical fiber with a coating fluid such as a resin liquid.

[Prior Art] As shown in FIG. 2, an optical fiber is manufactured by heating and melting an optical fiber preform 1 in a heating furnace 2 and spinning the melted optical fiber preform 1 to obtain an optical fiber 3. The fiber 3 is passed through an optical fiber coating device 4 to coat the surface thereof with a coating fluid such as a resin solution, and then passed through a curing device 5 to cure the coating fluid. It was done by winding at 8.

In this case, the conventional optical fiber coating apparatus 4 includes a coating die 9 and a nipple 10 combined with the coating die 9 as shown in FIG. Is formed between the inner surface of the tapered hole 11 of the coating die 9 and the outer peripheral surface of the distal end portion of the nipple 10. The coating fluid 14 is supplied and passes through the nipple 10 to the tapered hole 11.
The optical fiber 3 passing through the center of the optical fiber 3 is coated with the coating fluid 14. In addition, 15 is a die land part. In this case, the supply of the coating fluid 14 is performed from the fluid introduction hole 13 above the tip of the nipple 10 as shown in FIG. The flow of the coating fluid 14 is made uniform by narrowing the flow path formed between the coating die 9 and the nipple 10 so as to go around the entire circumference.

[Problems to be Solved by the Invention] However, the conventional optical fiber coating apparatus has the following problems.

(A) Since the fluid flow path portion 12 is formed between the nipple 10 and the coating die 9, eccentricity after assembly is likely to occur, and thus the coating layer of the optical fiber 3 is easily eccentric.

(B) In order to improve the uniformity of the flow of the coating fluid 14, a sufficient length of the nipple 10 to protrude into the coating die 9 is necessary, and in particular, the drilling of the nipple 10 becomes troublesome.

(C) The length of the optical fiber coating device in the optical fiber penetration direction becomes large.

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical fiber coating apparatus which can coat a coating fluid well even if the length is shortened and which can be easily processed at the time of manufacture.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a coated die and a nipple combined with the coated die, and an optical fiber passing through the center of the tapered hole of the coated die. In the optical fiber coating apparatus having a structure in which the coating fluid is coated, the coating die is provided with a fluid flow path for flowing the coating fluid in a direction opposite to a traveling direction of the optical fiber, and the fluid flow path is A gap between the nipple and the coating die communicates with the tapered hole.

[Function] A structure in which the coating die is provided with a fluid flow path portion in a direction opposite to the traveling direction of the optical fiber, and the fluid flow path portion communicates with the tapered hole in a gap between the nipple and the coating die. Accordingly, the required fluid flow path length can be obtained without increasing the length of the coating apparatus in the optical fiber penetration direction by the fluid flow path section in the opposite direction and the fluid flow path section in the tapered hole. The length of the nipple in the optical fiber penetrating direction can be shortened, so that the nipple can be easily drilled. The hole length of the coating die also becomes short, and the hole drilling of the coating die becomes easy.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. Parts corresponding to those in FIG. 3 described above are denoted by the same reference numerals. In the optical fiber coating apparatus according to the present embodiment, the coating die 9 is provided with a fluid flow path 16 for flowing the coating fluid 14 in a direction opposite to the traveling direction of the optical fiber 3. The fluid introduction hole 13 corresponds to the bottom of the fluid flow path 16.
Is provided. The fluid flow path portion 16 is opened on the upper surface of the coating die 9 and has a gap 17 between the nipple 10 and the coating die 9.
Communicates with the tapered hole 11. In order to form such a gap 17, a concave portion 18 is formed at the center of the lower surface of the nipple 10, and a downwardly protruding edge 10 A of the outer periphery of the lower surface of the nipple 10 is fitted to the outer periphery of the upper surface of the coating die 9 so as to secure the gap 17. Joint recess 9A
Is fitted. Due to such a structure, the nipple 10 has a flat shape, and the length of the nipple hole 19 is significantly shorter than that of the conventional one shown in FIG.

In such an optical fiber coating apparatus, the coating fluid 14 supplied from the fluid introduction hole 13 flows through the fluid flow path 16 in a direction opposite to the traveling direction of the optical fiber 3. At this time, since the fluid flow path portion 16 is formed larger than the fluid introduction hole 13, the coating fluid 14 can sufficiently flow around the entire circumference. The coating fluid 14 that has flowed in the reverse direction through the fluid flow path 16 flows into the tapered hole 11 of the coating die 9 through the gap 17 between the nipple 10 and the coating die 9. At this time, the coating fluid 14
Is uniformly squeezed by the gap 17 to flow into the tapered hole 11 uniformly. The coating fluid 14 is coated with a required thickness on the surface of the optical fiber 3 by the coating fluid 14 flowing in the tapered hole 11 in the forward direction (the traveling direction of the optical fiber 3).

According to experiments, the optical fiber coating device according to the present invention is:
It has been found that the length can be reduced to about half of the conventional length.

[Effect of the Invention] As described above, the optical fiber coating apparatus according to the present invention provides the coating die with the fluid flow path for flowing the coating fluid in a direction opposite to the traveling direction of the optical fiber. Utilizing the gap between the nipple and the coating die, the structure is made to communicate with the tapered hole of the coating die, so that the length of the optical fiber coating device in the traveling direction of the optical fiber is significantly shorter than the conventional one. There are advantages that can be. Also,
The nipple has the advantage that the length of the nipple in the optical fiber penetrating direction can be shortened, so that the nipple can be easily drilled. Furthermore, the coating die has both a fluid flow path portion and a tapered hole opened on the surface facing the nipple, and the length of the coating die in the direction in which the optical fiber penetrates is short. Also has the advantage of not having to be as high as in the past. Further, according to the present invention, coating without eccentricity can be easily performed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of an optical fiber coating apparatus according to the present invention, FIG. 2 is a schematic configuration diagram showing an example of an optical fiber manufacturing apparatus, and FIG. 3 is a longitudinal section of a conventional optical fiber coating apparatus. FIG. 3 ... optical fiber, 4 ... optical fiber coating device, 9 ...
Coating die, 10: Nipple, 11: Tapered hole, 13: Fluid introduction hole, 14: Coating fluid, 16: Fluid flow path, 17 ...
Gap.

Claims (1)

(57) [Claims] An optical fiber coating apparatus comprising a coating die and a nipple combined with the coating die, wherein an optical fiber passing through the center of the tapered hole of the coating die is coated with a coating fluid in the tapered hole. The coating die is provided with a fluid flow path for flowing the coating fluid in a direction opposite to the traveling direction of the optical fiber, and the fluid flow path includes a tapered hole formed in a gap between the nipple and the coating die. An optical fiber coating device, wherein the optical fiber coating device is in communication with the optical fiber coating device.