JPH11228187A - Method for cooling optical fiber and cooling device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for cooling an optical fiber capable of preventing the occurrence of the degradation in the strength and coating defect of the optical fiber by suppressing vibration at the time of drawing the optical fiber and a cooling device therefor. SOLUTION: A cooling gas controller 4 formed with a conical cooling gas guide part 14, a through-hole 16 allowing the passage of the optical fiber 15 and a discharge hole 13 for discharging a cooling gas is mounted at a cooling pipe 2 for cooling the optical fiber 15. At the time of drawing the optical fiber 15, the flowing direction of the cooling gas supplied into the cooling pipe 2 is guided in a direction parting from the optical fiber 15 by the tapered surface of the cooling gas guide part 14 and thereafter, the gas is discharged from the discharge hole 13. The cooling gas does not stagnate in the cooling pipe 2 and does not give rise to turbulence and, therefore, the vibration of the optical fiber 15 is suppressed and the degradation in strength and coating defect occurring in the vibration may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling method for cooling an optical fiber drawn in an optical fiber manufacturing process, and a cooling device for performing the cooling method.

[0002]

2. Description of the Related Art An example of a conventional optical fiber manufacturing method and a conventional manufacturing apparatus will be described with reference to FIGS. The heating furnace 31 is provided with a heater 32, and draws an optical fiber preform 33 supplied into the furnace while heating and melting the fiber preform 33 to obtain a fiber optical fiber 34. At this stage, the optical fiber 34 is easily damaged on the glass surface and has low tensile strength and bending strength. Therefore, a coating device 35 such as a dice is provided in the drawing path of the optical fiber 34, and the optical fiber 34 is continuously passed through the coating device 35, and the outer periphery thereof is coated with a silicone resin, a UV curing resin, or the like. . In addition, the resin for coating and the like are stored in
And supplied to the coating device 35 via a resin supply pipe 37. A curing furnace 38 is provided below the coating device 35. This curing furnace 38
The optical fiber 34 whose outer periphery is covered with a resin or the like is cured by heat or ultraviolet rays. The cured optical fiber 34 is taken up by a take-up device (not shown) provided below the curing furnace 38.

By the way, the optical fiber 3 in the spun state
Reference numeral 4 is obtained by heating and melting the optical fiber preform 33 as described above. When the drawing speed of the optical fiber 34 is low, or when the distance between the heating furnace 31 and the coating device 35 is sufficiently large, the optical fiber 34 is air-cooled before reaching the coating device 35, so that the optical fiber 34 is intentionally cooled. No need. However, when the drawing speed is high, or when the distance between the heating furnace 31 and the coating device 35 is short, the optical fiber 34 passes through the coating device 35 at a high temperature. Insufficient coating such as disturbance of coating or defective outer diameter of coating occurs. Conventionally, a cooling device 41 is disposed between the heating furnace 31 and the coating device 35 as shown in FIG. 12 to forcibly cool the drawn optical fiber 34 in order to prevent the coating defect. I was .

[0004] An example of a conventional cooling device 41 will be described below with reference to FIG. At the center of the cooling device 41, a cooling tube 42 formed in a cylindrical space in the vertical direction is provided, and small holes 42A and 42B for passing the optical fiber 34 are formed at the upper and lower ends thereof. . A cooling gas inlet 43 is provided at a lower portion of the cooling pipe 42, and is configured to supply a cooling gas such as helium into the cooling pipe 42 and to cool the optical fiber 34 by flowing the cooling gas from the lower part to the upper part of the cooling pipe 42. ing. The helium gas that has reached the upper part of the cooling pipe 42 is discharged from the upper small hole 42A. Cooling pipe 4
The outside of 2 is covered by an annular cooling section 44.
The cooling unit 44 supplies a cooling liquid from a cooling liquid inlet 45 formed at a lower part, and a cooling liquid discharge hole 46 formed at an upper part.
It is configured to discharge from. Then, while the cooling liquid flows through the cooling section 44, heat of the cooling gas flowing through the cooling pipe 42 is taken away, and the cooling effect of the optical fiber 34 is improved. In Japanese Patent Application Laid-Open No. 61-72645,
A cooling device having a cooling function similar to the above is disclosed.

[0005]

However, the cooling device 41 and the cooling device disclosed in the above publication have the following problems. That is, the cooling gas supplied from the cooling gas inlet 43 flows upward through the cooling pipe 42 and is discharged to the outside through the small hole 42A, but the upper part of the cooling pipe 42 indicated by the arrow X, in other words, For example, turbulence tends to occur near the position where the optical fiber 34 is introduced into the cooling pipe 42, and when the turbulence occurs, the optical fiber 34 vibrates. On the other hand, when increasing the linear velocity of the optical fiber 34,
In order to increase the cooling efficiency, a large amount of cooling gas needs to be circulated. However, if a large amount of cooling gas is circulated as the linear velocity increases, the optical fiber 34 vibrates more violently. When the vibration of the optical fiber 34 increases,
The optical fiber 34 abuts on a die, a nipple, or the like of the coating device 35, and as a result, the strength of the optical fiber 34 may be reduced or a coating defect may occur due to vibration.

As a means for solving the problem of vibration of the optical fiber 34, Japanese Patent Application Laid-Open No. 7-330384 discloses a "method of manufacturing an optical fiber and a cooling device used for the same". Hereinafter, the outline will be described with reference to FIG.
The cooling device 51 has gas inlets 53 and 54 for supplying a cooling gas in two upper and lower stages at substantially the center in the longitudinal direction of the cooling pipe 52, and gas reservoirs 55 and 56 communicating with the gas inlets 53 and 54, respectively. Injection ports 57 and 58 for injecting the cooling gas in the circumferential direction in the cooling pipe 52 are formed. However, the blowing directions of the blowing ports 57 and 58 are opposite to each other.

The optical fiber 34 is cooled by the cooling device 51.
Is cooled, the cooling gas is supplied from the gas inlets 53 and 54 while passing the optical fiber 34 through the cooling pipe 52. The cooling gas once enters the gas reservoirs 55 and 56 and then blows out from the blowing ports 57 and 58 into the cooling pipe 52. At this time, the cooling gas turns around the optical fiber 34, and the turning direction of the cooling gas blown out from the upper blowing port 57 turns clockwise as viewed from above the cooling device 51, and the lower blowing The turning direction of the cooling gas blown out from the port 58 turns counterclockwise. The cooling gas blown out from the blowing port 57 is discharged from the upper end of the cooling pipe 52, and the cooling gas blown out from the blowing port 58 is discharged from the lower end of the cooling pipe 52. In the cooling device 51, the optical fiber 34 can be cooled and the optical fiber 3 can be cooled.
By forming a vortex of the cooling gas around the optical fiber 4, the rotational force acting on the optical fiber 34 is offset, and the optical fiber 34
Is suppressed.

However, in this apparatus, since the optical fiber 34 is cooled by the vortex of the cooling gas and the entry of external air is prevented, it is necessary to supply a large amount of cooling gas as the linear velocity increases. Therefore, the optical fiber 34
In response to the increase in the production of, the consumption of the cooling gas has increased, which has contributed to the high cost. Note that Japanese Patent Application Laid-Open
JP-A-65747 and JP-A-2-267139 also disclose optical fiber manufacturing methods and cooling methods, but none of these problems can be solved at once.

The present invention has been made in view of the above circumstances, and has as its object to suppress the vibration of an optical fiber caused by the flow of a cooling gas when cooling a drawn optical fiber with a cooling gas. It is an object of the present invention to provide an optical fiber cooling method and an optical fiber cooling device that prevent a decrease in fiber strength and a coating failure from occurring.

[0010]

The object according to the present invention is achieved by an optical fiber cooling method and an optical fiber cooling device described in the following (1) to (4). (1) An optical fiber formed by heating and melting an optical fiber base material and drawing the optical fiber is passed through a cooling device having a cylindrical cooling pipe before the step of coating with a resin, and the passage direction of the optical fiber and Is a method of cooling an optical fiber cooled by a cooling gas flowing in the opposite direction, wherein the cooling gas is guided in a direction away from the optical fiber and discharged near the position where the optical fiber has entered the cooling pipe. A method for cooling an optical fiber, comprising:

(2) An optical fiber formed by heating and melting an optical fiber preform and drawing the fiber is passed through a cylindrical cooling pipe before the step of coating with a resin, and in a direction opposite to the direction in which the optical fiber passes. In a cooling device for an optical fiber that cools by a cooling gas flowing through, a passing hole through which the optical fiber passes, a cooling gas guide portion formed in a conical shape with the passing hole as a top, and a cooling gas guide portion. A cooling gas controller having a hole-shaped cooling gas outlet formed at an outer edge base portion is detachably provided at an opening for introducing the optical fiber among the openings of the cooling pipe. Optical fiber cooling device.

(3) The cooling gas controller is divided into two parts to form a half-split structure, which is removed from the cooling pipe when the optical fiber is passed through the cooling pipe. The optical fiber cooling device according to (2), which is attached to a tube.

(4) The cooling gas outlet provided in the cooling gas controller is configured to discharge the cooling gas in a direction parallel to the optical fiber inside the cooling pipe and away from the optical fiber outside the cooling pipe. The optical fiber cooling device according to (2) or (3), wherein the cooling device is formed as follows.

In the cooling method of the optical fiber, the cooling gas flowing through the cooling pipe is guided near the position where the optical fiber enters the cooling pipe in a direction away from the optical fiber, and is discharged. Gas stagnation and turbulence are eliminated. As a result, there is no interference with the optical fiber by the cooling gas, and the vibration of the optical fiber can be suppressed.
Various problems caused by vibration can be prevented from occurring.

According to the optical fiber cooling device, the flow of the cooling gas flowing through the cooling pipe is converted in a direction away from the optical fiber by the conical cooling gas guide provided in the cooling gas controller. Since a plurality of cooling gas outlets are formed at the base of the cooling gas controller, the cooling gas whose flow has been converted is discharged from the cooling gas outlet without staying in the cooling pipe. Therefore, there is no interference of the cooling gas with the optical fiber, the vibration of the optical fiber can be reduced, and various problems caused by the vibration can be prevented.

Further, the cooling gas controller is divided in half so that the optical fiber is introduced into the cooling pipe and then stabilized before being attached to the cooling pipe. Undesirable contact with the controller can be prevented, and cutting and coating failure of the optical fiber can be prevented. Further, by forming the cooling gas outlet into a shape that discharges the cooling gas in a direction away from the optical fiber, it is possible to prevent the cooling gas from being blown against the optical fiber, which is caused by vibration or vibration of the optical fiber. Can be prevented from occurring.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of an optical fiber cooling method and an optical fiber cooling apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of the cooling device, FIG. 2 is a perspective view showing the configuration of the cooling gas controller, FIG. 3 is a bottom view showing the configuration of the cooling gas controller, and FIG. FIG. 5 is a side view showing the configuration of the cooling gas controller, and FIG. 6 is a characteristic diagram showing the measurement results of the breaking strength and breaking probability of the optical fiber. In the description of the embodiment, the configuration of the cooling device will be described, and then the operation of the cooling method and the like will be described. The drawings and the like referred to in the conventional example are appropriately used.

The cooling device 1 shown in FIG. 1 is disposed below the heating furnace 31 in the process of manufacturing an optical fiber as described with reference to FIG. Hereinafter, the configuration of the cooling device 1 will be described. In the configuration, an annular cooling section 3 is integrally provided outside a cylindrical cooling pipe 2, and a cooling gas controller 4 is disposed at an upper opening of the cooling pipe 2. Has become. A cooling gas inlet 5 for supplying a cooling gas is provided at a lower portion of the cooling pipe 2.
Is provided. A cooling liquid inlet 6 for supplying a cooling liquid is provided at a lower part of the cooling part 3, and a cooling liquid outlet 7 is provided at an upper part thereof.
Is provided.

As shown in FIGS. 2 to 5, the overall shape of the cooling gas controller 4 is such that the upper portion is formed in a plane and the lower portion is formed in a conical shape. The outer periphery of the cooling gas controller 4 is formed in an annular flange portion 11, and a plurality of cooling gas outlets 13 are formed in an annular flat portion 12 having a step with respect to the flange portion 11. The conical portion constitutes the cooling gas guide portion 14 according to the present invention, and changes the traveling direction of the cooling gas in a direction away from the optical fiber 15, in other words, in a direction toward the inner wall of the cooling pipe 2. A passage hole 16 for allowing the optical fiber 15 to pass therethrough is formed.

When the cooling gas controller 6 is mounted on the cooling pipe 2, as shown in FIG. 1, the flange 11 is hung on the upper edge of the cooling pipe 2, and the flat plate 12 and the cooling gas guide 14 are connected to the cooling pipe 2. 2 In the present embodiment, the upper part of the cooling pipe 2 is opened in a cylindrical shape, but by attaching the cooling gas controller 6, the inside and the outside of the cooling pipe 2 are connected to a plurality of cooling gas outlets 13 and the light formed in the center. The communication is established with the passage hole 16 of the fiber. The number and intervals of the cooling gas outlets 13 are not particularly limited, but a plurality of cooling gas outlets 13 are formed at equal intervals in order to smoothly discharge the cooling gas and prevent stagnation and turbulence. Is preferred.

The cooling device 1 according to the present embodiment has a structure shown in FIG.
Can be applied. Therefore, the embodiment will be described with reference to FIG. 12. The optical fiber preform 33 shown in FIG. 12 has an outer diameter of 36 mm, and the temperature of the heater 32 is set to 2000 ° C. to heat the optical fiber preform 33. It was melted and drawn so that the optical fiber 15 became 125 μm.

The optical fiber 15 is cooled by the cooling device 1. At the time of cooling, the following notable actions are performed. That is, the optical fiber 15 is introduced into the cooling pipe 2 through a passage hole 16 formed at the center of the cooling gas controller 4, passes through the cooling pipe 2 in the longitudinal direction, and passes through a cooling hole 17 formed at the lower part through the cooling pipe 17. 2 out. On the other hand, a cooling gas is supplied from the cooling gas inlet 5 into the cooling pipe 2, and a cooling liquid is supplied from the cooling liquid inlet 6 into the cooling unit 3. The cooling gas rises in the cooling pipe 2 as shown by an arrow A while cooling the optical fiber 15 passing through the cooling pipe 2. When the cooling gas reaches the lower part of the cooling gas controller 14,
The flow direction changes in a direction away from the optical fiber 15 as shown by an arrow B while rising along the tapered surface of the cooling gas guide portion 14.

Since the cooling gas guide 14 is formed in a conical shape downward as shown in each figure, the flow of the cooling gas in the direction of arrow B is diffused throughout the radial direction (360 °). The cooling gas flowing along the cooling gas guide 14 is discharged from the plurality of cooling gas outlets 13 to the outside of the cooling pipe 2 as shown by an arrow C. Therefore, in the present embodiment, there is no stagnation of the cooling gas in the upper part of the cooling pipe 2, that is, in the vicinity of the position where the optical fiber 15 is introduced, and no turbulence occurs. As a result, the vibration of the optical fiber 15 is greatly reduced, and an accident in which the optical fiber 15 comes into contact with the die or the nipple of the coating device 35 is prevented beforehand, and the strength can be prevented from lowering.

Here, the measurement results of the breaking strength and the breaking probability of the optical fiber 34 cooled by the cooling device 41 described with reference to FIG. 13 and the optical fiber 15 cooled by the cooling device 1 in this embodiment are shown. This will be described with reference to FIG.
As is clear from FIG. 6, according to the present embodiment, the breaking strength was constant and all the samples broke under a load of 6 kgf. On the other hand, according to the conventional example, many samples broke even if the breaking strength was 5 kgf or less. From this, the optical fiber 15 manufactured by applying the cooling device of the present embodiment,
It can be seen that the strength has increased significantly. This means that the vibration of the optical fiber 15 during drawing is reduced. Further, no coating failure occurred on the optical fiber 15 manufactured by applying the cooling device 1 of the present embodiment.

In this embodiment, the cooling gas controller 4 removes a high-temperature air layer which is wound around the cooling pipe 2 from outside the cooling device 1 by the optical fiber 15 and formed around the optical fiber 15. ing. When the linear velocity is increased, the problem is that the air is caught from the outside,
The temperature rise of the optical fiber 15 itself. In the configuration of the present embodiment, since the optical fiber 15 passes through the narrow passage hole 16 of the cooling gas controller 4, the air following the movement of the optical fiber 15 is physically scraped by the upper surface of the cooling gas controller 4. Has been removed. Therefore, according to the present embodiment, the amount of the cooling gas used can be reduced as compared with the conventional configuration in which the inflow of external air is prevented by the vortex of the cooling gas facing the inlet direction of the cooling device. In addition, since the cooling gas that has contributed to the cooling of the optical fiber 15 is guided by the cooling gas controller 4 in a direction away from the optical fiber 15 and is discharged, the flow of the cooling gas becomes smooth and the cooling efficiency also increases. Therefore, the optical fiber 15 can be efficiently cooled even when the linear velocity increases.

As described above, in this embodiment, the cooling gas controller 4 physically removes the high-temperature air that is to follow the optical fiber 15 in the cooling pipe 2. Further, the cooling gas that has reached the vicinity of the entrance of the cooling pipe 2 by contributing to the cooling of the optical fiber 15 is scooped from the optical fiber 15 by the cooling gas guide 14 of the cooling gas controller 4 and physically removed. Discharge. This makes it possible to efficiently cool the optical fiber, prevent coating defects due to turbulence of the cooling gas, and provide an optical fiber with high strength.

Next, a second embodiment of the present invention will be described with reference to FIG. Note that the present embodiment relates to a cooling gas controller, and FIG. 7 is a perspective view showing a configuration of the cooling gas controller. Cooling gas controller 21 in the present embodiment
The cooling gas controller 4 described in the first embodiment is divided into two, that is, halved from the center, and two cooling gas controllers 21 are attached to the cooling pipe 2 together. The cooling gas controller 21 has a flange 11, a flat portion 12, a plurality of cooling gas outlets 13, a cooling gas guide 14, and a through hole 16 formed in half, and a vertically formed mating surface 22. By joining, the same function as described above is exhibited.

The reason for such a half-split configuration is that after the start of the optical fiber 15, the cooling gas controller 2
1 is attached to the cooling pipe 2. That is, when the optical fiber 15 is drawn, the cooling gas controller 21 is not attached at the time of the start line. Therefore, the upper portion of the cooling pipe 2 has a large-diameter opening, and the optical fiber 15 can be easily introduced into the cooling pipe 2. And the optical fiber 1
5 is set from the cooling pipe 2 to a coating device and further to a winding device (not shown), and after the optical fiber 15 is stabilized, the cooling gas controller 21 is inserted so as to sandwich the optical fiber 15.
Attach. In this manner, when the cooling gas controller 21 is attached together, the configuration is substantially the same as that of the cooling gas controller 4, and the same function is exhibited.

According to this configuration, the optical fiber 15 can be smoothly passed through. Immediately after the optical fiber 15 is drawn, the optical fiber 15 is likely to vibrate until the drawing speed or the tension becomes a certain level. However, by dividing the cooling gas controller 21 in half, the optical fiber 15 can be attached to the cooling pipe 2 after the optical fiber 15 is stabilized, so that the optical fiber 15 does not hit the cooling gas controller 21 and the optical fiber 15 is drawn. Cutting, damage, etc. can be prevented beforehand.

Next, a third embodiment of the present invention will be described with reference to FIGS. 8 is a perspective view showing the configuration of the cooling gas controller, FIG. 9 is a bottom view, FIG. 10 is a plan view, and FIG. 11 is a side view. The cooling gas controller 25 according to the present embodiment has a configuration in which the cooling gas controller 25 is halved similarly to the second embodiment, but the configuration of the cooling gas outlet 26 is different from each of the above embodiments. That is, as shown in FIGS. 8 and 11, the upper ends of the plurality of cooling gas outlets 26 are opened outward at the upper part of the flange portion 11. This configuration is such that the cooling gas outlet 26 is formed radially with respect to the passage hole 16 through which the optical fiber 15 passes, and the discharged cooling gas is not directed upward but in the lateral direction, and the optical fiber 15 Will diffuse away from the surface.

The cooling device 1 is disposed below the heating furnace 31 in the same manner as described above, but if the distance between them is short, the cooling gas may enter the heating furnace 31 and disturb the outer diameter of the optical fiber 15. is there. Also, the cooling gas from the cooling device 1
There is also a possibility that vibration may be given by hitting 5. However, according to the present embodiment, the cooling gas is
Therefore, the above problem can be prevented from occurring. This configuration is suitable when the distance between the heating furnace and the cooling device is short, and when the flow rate of the cooling gas is large.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above. For example, the structure of the cooling gas outlet 26 shown in the third embodiment can be applied to the cooling gas controller 4 shown in the first embodiment. Also in this case, the cooling gas can be discharged in the lateral direction as in the above case, and the same effects as in the third embodiment can be obtained.

[0033]

The optical fiber cooling method and the optical fiber cooling device according to the present invention described above have the following various effects. (1) Since the flow direction of the cooling gas for cooling the optical fiber is guided in a direction away from the optical fiber and is smoothly discharged, the cooling gas does not stay in the cooling pipe or becomes turbulent, and the vibration of the optical fiber does not occur. Can be suppressed. (2) By suppressing the vibration of the optical fiber, it is possible to prevent the optical fiber from hitting a die or a nipple of the coating apparatus, and it is possible to prevent the occurrence of accidents such as lower strength and cutting.

(3) By suppressing the vibration of the optical fiber, coating defects of the optical fiber can be reduced. (4) By constructing the cooling gas controller in half so as to attach the optical fiber to a cooling pipe after drawing the optical fiber to a cooling device or the like, the drawing operation at the start of drawing becomes easy. Further, even when the vibration of the optical fiber immediately after the drawing is severe, the cooling gas controller can be mounted after the vibration has subsided, so that the optical fiber can be prevented from being damaged or cut. (5) The direction of the cooling gas outlet provided in the cooling gas controller is
By arranging the cooling gas to be discharged in the direction away from the optical fiber, even if the distance between the heating furnace and the cooling device is short, it is possible to prevent the cooling gas from hitting the optical fiber or the heating furnace. Even if the flow rate of the cooling gas is large, fluctuations in the outer diameter of the optical fiber, generation of vibration, and the like can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cooling device according to a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a configuration of a cooling gas controller.

FIG. 3 is a bottom view showing a configuration of a cooling gas controller.

FIG. 4 is a plan view showing a configuration of a cooling gas controller.

FIG. 5 is a side view showing a configuration of a cooling gas controller.

FIG. 6 is a characteristic diagram showing measured values of breaking strength and breaking probability of an optical fiber.

FIG. 7 is a perspective view of a cooling gas controller according to a second embodiment of the present invention.

FIG. 8 is a perspective view of a cooling gas controller according to a third embodiment of the present invention.

FIG. 9 is a bottom view of the cooling gas controller.

FIG. 10 is a plan view of a cooling gas controller.

FIG. 11 is a side view of the cooling gas controller.

FIG. 12 is a configuration diagram illustrating an example of a conventional optical fiber manufacturing apparatus.

FIG. 13 is a sectional view showing a first example of a conventional cooling device.

FIG. 14 is a sectional view showing a second example of a conventional cooling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling device 2 Cooling pipe 3 Cooling part 4 Cooling gas controller 5 Cooling gas inlet 6 Cooling liquid inlet 7 Cooling liquid outlet 11 Flange part 12 Flat part 13 Cooling gas outlet 14 Cooling gas guide part 15 Optical fiber 16 Passing hole 17 Discharge Hole 31 Heating furnace 35 Coating device

Claims (4)

[Claims] An optical fiber formed by heating and melting an optical fiber preform and drawing the optical fiber is passed through a cooling device having a cylindrical cooling pipe before the resin coating step, and the optical fiber is passed through the optical fiber. In a method for cooling an optical fiber cooled by a cooling gas flowing in a direction opposite to a direction, the cooling gas is guided in a direction away from the optical fiber and discharged near a position where the optical fiber enters the cooling pipe. A method for cooling an optical fiber. 2. An optical fiber formed by heating and melting an optical fiber preform and drawing the optical fiber is passed through a cylindrical cooling pipe before coating with a resin, and is passed in a direction opposite to a direction in which the optical fiber passes. An optical fiber cooling device for cooling with a flowing cooling gas, comprising: a through hole through which the optical fiber passes; a conical cooling gas guide having the through hole as a top; and an outer edge of the cooling gas guide. A cooling gas controller having a hole-shaped cooling gas outlet formed in a base portion, the cooling gas controller being detachably provided in an opening for introducing the optical fiber among the openings of the cooling pipe; Fiber cooling device. 3. The cooling gas controller is divided into two parts to form a half-split structure, which is removed from the cooling pipe when the optical fiber is passed through the cooling pipe, and the cooling pipe is aligned after the optical fiber is passed through the cooling pipe. 3. The optical fiber cooling device according to claim 2, wherein the optical fiber cooling device is mounted on the optical fiber. 4. The cooling gas outlet provided in the cooling gas controller is parallel to the optical fiber in the cooling pipe,
4. The optical fiber cooling device according to claim 2, wherein a cooling gas is discharged outside the cooling pipe in a direction away from the optical fiber.