JPH0240620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin coating die device for coating an optical fiber immediately after spinning with a resin for surface protection.

The optical fiber is manufactured, for example, by a method as shown in FIG.

That is, the base material 1 of the optical fiber connected to the dummy rod is held between the chucks and suspended vertically. The tip of this base material 1 is guided to a spinning furnace 2, where the base material 1 is softened, and one end is drawn by a wire drawing device to form an optical fiber 3 with a predetermined diameter. It is. In this case, the spinning furnace 2
The outer diameter of the optical fiber 3 guided out from the fiber is measured in an optical non-contact manner by an outer diameter measuring device 4, and immediately after that, it is passed through a resin coating die 5,
In order to protect the surface of the optical fiber 3, a resin coating is applied and dried in a drying oven 6.

However, when forming the resin coating on the optical fiber 3 using the coating die 5, the following problem occurred.

That is, the coating die 5 usually has a two-part structure, is set on the base 7, and after centering via the fine adjustment mechanism 8, the die 5 is attached to a band or a clip. The fasteners 9 are used to prevent the coating resin from leaking outside from the joints of the coating dies.

However, in the case of the above method, since the resin coating die 5 is precisely centered and then fastened with the fastener 9, the resin coating die 5 may be misaligned or carelessly moved, and the small diameter light There was a risk of cutting the fiber 3. In addition, due to loosening or deterioration of the fasteners that fasten the resin coating die 5, a gap is created between the split molds, and the coating resin leaks to the outside from this gap, and the leaked resin adheres to the optical fiber 3. However, there were problems such as making uniform coating impossible.

The present invention has been made based on the above circumstances, and is a coating die that prevents coating resin from leaking to the outside, enables uniform resin coating, facilitates setting, and prevents optical fiber breakage accidents. The purpose is to provide

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a perspective view of a die main body in an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view showing the overall configuration of the embodiment. In FIG. 2, the die body 11
has a two-part structure divided in a plane including its axis, and consists of divided parts A and B. Dice body 1
1 is a right cylindrical part 12 with a large diameter at the upper end, and a tapered part 13 which is connected to the lower end of this right cylindrical cylinder and whose diameter decreases downward.
and a small-diameter right cylindrical portion 1 connected to this tapered lower end.
It has an external shape consisting of 4.

Therefore, the die body 11 has the die body 1
A conical inner cavity 15 is provided which opens at the upper end of the tapered part 13, decreases in diameter toward the vicinity of the lower end of the tapered part 13, and terminates near the lower end. A die hole 16 provided through it is in communication.

Further, near the upper end of the tapered portion 13, a plurality of horizontal and radial through holes 17 communicating with the inner cavity 15 are provided at equal intervals in the circumferential direction.

Further, the right cylindrical portion 1 at the lower end of the die body 11
4 is provided with a diffusion surface 18 which is a tapered concave surface whose diameter increases from the center toward the periphery.

Note that the dividing surface of the die body 11, that is, the abutting surfaces of the divided pieces A and B are precisely finished by rubbing or the like. Further, the diameter of the through hole 17 provided near the upper end of the tapered portion 13 and its drilling position are determined as will be explained later in relation to the die holder which will be explained later.

As shown in FIG. 3, the die holder 19 includes a hollow cylindrical container portion 20 with an open top end for accommodating a coating resin agent, and a bottom plate 21 provided at the center of the container portion 20 and having a taper angle equal to the taper portion 13 of the die body. It has a die body holding hole 22 with which the die body 11 is tightly engaged.

The die body 11 is attached to the die holder 19 having the above configuration.
is retained as follows. That is, the divided pieces A and B are brought into contact with each other at their divided surfaces, and their axial positions are matched, and then they are placed in the die holder 19.
The die body holding hole 22 is inserted into the die body holding hole 22, and a pressing force is applied appropriately. By doing so, the divided parts A and B constituting the die body 11 are integrated by abutting their precision-finished divided surfaces to form the die body 11, and at the same time, this die body 11 can be used as a die holder. It will be firmly held at 19.

The diameter of the through hole 17 and its drilling position are as follows:
The die body 11 is selected so that when the die body 11 is inserted and held in the die body holding hole 22, at least a portion of the through hole 17 is located above the inner surface of the bottom plate 21.

In the above configuration, when the coating agent 23 is injected into the container portion 20 of the holder 19, the coating agent 23 flows into the inner cavity 15 through the through hole 17 of the die body 11.

Therefore, if the optical fiber 24 is passed through the center of the inner cavity 15 in the axial direction,
The coating agent within the lumen 15 flows out through the outflow groove 16 and adheres to the outer surface of the optical fiber 24, forming a resin coating 25 of a predetermined thickness.

In this case, the excess coating agent 23 is guided by the tapered shape of the diffusing surface 18 and is removed from the optical fiber 2.
Since the flow is in the direction away from 4, it is no longer possible to form a resin coating with a non-uniform outer shape as in the conventional case.

That is, in the past, as shown in FIG. 4, the bottom surface of the resin coating die 11 was formed flat, so the coating agent 23 flowing out from the die hole 16 went around the bottom surface, and the coating agent accumulated there. 23 was partially attached to the outer periphery of the optical fiber 25, and a knob-like coating 26 was easily formed.

However, in the present invention, since the diffusion surface 18 is provided at the tip of the resin coating die 11, as shown in FIG. The resin coating 25 can be formed uniformly since the resin is guided toward the optical fiber 24 and does not adhere to the optical fiber 24.

As described above, according to the present invention, it is easy to set up the resin coating die, and once it is set, there is no need to touch it with your hands, thereby preventing the accident of cutting the optical fiber due to careless horizontal movement. can be prevented and the yield can be significantly improved. Furthermore, leakage of the coating agent is guided by the diffusion surface and directed outward with respect to the optical fiber, so that a uniform resin coating can be formed since there is no risk of the coating agent adhering to the optical fiber.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a method for manufacturing an optical fiber, FIG. 2 is a perspective view of a die body which is a main part of the present invention, and FIG. 3 is a cross-sectional view showing the overall configuration of an embodiment of the present invention. 4 is a sectional view showing a state in which a resin coating is formed on an optical fiber using a conventional resin coating die, and FIG. 5 is a sectional view showing a state in which a resin coating is formed on an optical fiber using the above-mentioned die of the present invention. FIG. 11...Dice body, 12, 14...Right cylindrical part, 13...Tapered part, 15...Inner cavity, 16...
Dice hole, 17... Through hole, 18... Diffusion surface, 19
... Dice holder, 20 ... Container part, 21 ... Bottom plate, 22 ... Dice body holding hole, 23 ... Coating agent, 24 ... Optical fiber, 25 ... Resin coating.

Claims (1)

[Claims] 1. The outer shape consists of a large-diameter right cylindrical part that is divided into two in a plane including the axis, a tapered part that continues to the lower end of this right cylinder and whose diameter decreases downward, and a small-diameter right cylindrical part that continues to the lower end of this taper. The inner lumen has a tapered surface that opens at the upper surface of the large-diameter right cylindrical part and whose diameter decreases downward, and a die hole that communicates with the lower end of the inner lumen, and the inner lumen is located near the upper end of the tapered part. A die body is provided with a plurality of horizontal and radial through holes communicating with the die body, and a hollow cylindrical shape with an open top end is provided at the center of the bottom plate and has a taper that matches the tapered surface of the die body. A die device for resin coating, comprising: a die holder having a die body holding hole into which a portion below the plurality of through holes is fitted.