JP2014231465A - Apparatus and method for manufacturing glass fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass fiber manufacturing apparatus and a manufacturing method, which can cool a glass fiber in an excellent cooling efficiency while preventing the occurrence of a deficiency that a glass fiber contacts with a cooling device and breaks.SOLUTION: An apparatus for manufacturing a glass fiber G1 comprises: a heating furnace 2 for heating and softening a glass preform G, and a cooling device 7 for cooling the glass fiber G1 drawn from the glass preform G softened in the heating furnace 2. The cooling device 7 includes a cylindrical cooling pipe 21 having an insertion passage 22 therein for passing the glass fiber G1 advancing in a fiber drawing direction A and adapted to be supplied with a cooling gas in the insertion passage 22. In the cooling pipe 21, the distance normal to the drawing direction A and between the inner face of the insertion passage 22 and the glass fiber G1 is made shorter toward the downstream side of the drawing direction A.

Description

  The present invention relates to a glass fiber manufacturing apparatus and a manufacturing method for manufacturing a glass fiber by drawing a glass fiber from a glass base material.

  An optical fiber having a configuration in which a glass fiber having a core and a cladding is coated with a resin is known. The glass fiber constituting the optical fiber is manufactured by heating and softening the lower end side of a glass preform made of a material such as quartz, and stretching the softened portion to reduce the diameter. The high-temperature glass fiber after being stretched is forcedly cooled before the resin coating by passing through a cylindrical cooling device to which a cooling gas such as helium is supplied (see, for example, Patent Document 1). .

JP-A-11-130458 JP 2007-63086 A JP 2004-250292 A JP-A-11-171582

  In the section from the lower end portion of the glass base material to the coating device that coats the resin, the drawn glass fiber is not supported, and thus a phenomenon called line runout in which the glass fiber vibrates may occur. Due to this line runout, the glass fiber may come into contact with the inner surface of the insertion path in the cooling device and break. On the other hand, the cooling efficiency of the glass fiber in the cooling device is determined by the distance between the inner surface of the insertion path through which the glass fiber passes and the glass fiber, the flow rate of the cooling gas, and the like. If the inner diameter of the insertion path in the cooling device is increased in order to prevent disconnection due to the contact of the glass fiber, the cooling efficiency of the glass fiber is lowered. As described above, in consideration of preventing the breakage of the glass fiber, it is difficult to increase the cooling efficiency by the cooling device.

  The present invention provides a glass fiber manufacturing apparatus and manufacturing method capable of cooling a glass fiber with good cooling efficiency while preventing the occurrence of a problem that the glass fiber contacts the cooling device and breaks. Objective.

The glass fiber manufacturing apparatus of the present invention comprises:
A heating furnace that heats and softens the glass base material;
A cooling device for cooling the glass fiber drawn from the glass base material softened in the heating furnace,
The cooling device has a cylindrical cooling pipe having an insertion passage for allowing the glass fiber traveling in the drawing direction to pass therethrough and a cooling gas being supplied into the insertion passage,
In the cooling pipe, the distance perpendicular to the drawing direction between the inner surface of the insertion passage and the glass fiber is smaller toward the downstream side in the drawing direction.

The method for producing the glass fiber of the present invention comprises:
A glass fiber is drawn from a glass base material that has been softened by heating, and the glass fiber that advances in the drawing direction is passed through the insertion passage of a cooling pipe having an insertion passage to which a cooling gas is supplied to cool the glass fiber. In the process,
The distance orthogonal to the drawing direction between the inner surface of the insertion path of the cooling pipe and the glass fiber is reduced toward the downstream side in the drawing direction.

  ADVANTAGE OF THE INVENTION According to this invention, glass fiber can be cooled by favorable cooling efficiency, preventing generation | occurrence | production of the malfunction which a glass fiber contacts a cooling device and breaks.

It is a schematic block diagram of the optical fiber manufacturing apparatus provided with the glass fiber manufacturing apparatus which concerns on this invention. It is a schematic sectional drawing of a cooling device. It is a schematic sectional drawing of the cooling pipe which has the insertion path of the same internal diameter over the longitudinal direction. 6 is a schematic cross-sectional view of a cooling pipe according to Modification 1. FIG. 6 is a schematic cross-sectional view of a cooling pipe according to Modification 2. FIG. 10 is a schematic cross-sectional view of a cooling pipe according to Modification 3. FIG.

<Outline of Embodiment of the Present Invention>
First, an outline of an embodiment of the present invention will be described.
One embodiment of a glass fiber manufacturing apparatus according to the present invention,
(1) a heating furnace that heats and softens the glass base material;
A cooling device for cooling the glass fiber drawn from the glass base material softened in the heating furnace,
The cooling device has a cylindrical cooling pipe having an insertion passage for allowing the glass fiber traveling in the drawing direction to pass therethrough and a cooling gas being supplied into the insertion passage,
In the cooling pipe, the distance perpendicular to the drawing direction between the inner surface of the insertion passage and the glass fiber is smaller toward the downstream side in the drawing direction.
According to the structure of (1), the distance orthogonal to the drawing direction of the inner surface of the insertion path of a cooling pipe and glass fiber is so small that it goes to the downstream of a drawing direction. In general, the glass fiber linear vibration becomes the vibration of the primary mode, and thus becomes the maximum at the intermediate portion of the fixed point. In other words, considering the normal arrangement of the device, the upper part of the cooling device has more line runout. The contact between the inner surface of the insertion path and the glass fiber can be prevented. Further, since the cooling gas is pulled downstream by the glass fiber, the cooling gas concentration on the downstream side where the distance between the inner surface of the insertion path and the glass fiber is small is increased, and the cooling efficiency is further improved. Thereby, it is possible to cool the glass fiber with a good cooling efficiency while preventing the occurrence of a problem that the glass fiber contacts the cooling device and breaks. Therefore, a high quality glass fiber can be manufactured with a high yield.

(2) The cooling pipe may be configured such that a distance perpendicular to the drawing direction between the inner surface of the insertion passage and the glass fiber is the largest at the inlet of the cooling pipe and the smallest at the outlet of the cooling pipe. Good.
According to the configuration of (2), since the inlet portion of the cooling pipe is the largest and the outlet portion is the smallest, it is easier to prevent contact with the inner surface of the glass fiber insertion path on the inlet portion side, It is easy to further improve the cooling efficiency.

(3) The cooling pipe is configured such that a distance perpendicular to the drawing direction between the inner surface of the insertion passage and the glass fiber gradually decreases from an inlet portion of the cooling pipe toward an outlet portion of the cooling pipe. Also good.
According to the structure of (3), it becomes easy to make the flow of the cooling gas in an insertion path smooth, and can aim at the further improvement of cooling efficiency.

(4) In the cooling pipe, a plurality of divided bodies formed in a cylindrical shape may be connected along the drawing direction.
According to the structure of (4), since the cooling pipe is comprised by connecting a some division body, it is easy to produce a elongate cooling pipe.

(5) In the cooling pipe, a distance perpendicular to the drawing direction between the inner surface of the insertion passage and the glass fiber may continuously change at the connection portion of the divided body.
According to the structure of (5), it becomes easy to make the flow of the cooling gas in an insertion path smooth, and it can aim at the further improvement of cooling efficiency.

In addition, an embodiment of a method for producing a glass fiber according to the present invention,
(6) A glass fiber is drawn from a glass base material that has been softened by heating, and the glass fiber that advances in the drawing direction is passed through the insertion passage of a cooling pipe having an insertion passage to which cooling gas is supplied. In the process of cooling
The distance orthogonal to the drawing direction between the inner surface of the insertion path of the cooling pipe and the glass fiber is reduced toward the downstream side in the drawing direction.
According to the structure of (6), like the manufacturing apparatus of (1), it is possible to cool the glass fiber with good cooling efficiency while preventing the occurrence of the problem that the glass fiber contacts the cooling pipe and breaks. it can.

<Details of Embodiment of the Present Invention>
Hereinafter, an example of an embodiment of a manufacturing device and a manufacturing method of a glass fiber concerning the present invention is explained with reference to drawings. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to a claim are included.

(Configuration of manufacturing equipment)
FIG. 1 is a schematic configuration diagram of an optical fiber manufacturing apparatus including a glass fiber manufacturing apparatus according to the present embodiment.
As shown in FIG. 1, the glass fiber manufacturing apparatus 1 includes a heating furnace 2 for heating the glass base material G on the most upstream side, and includes a cooling device 7 and an outer diameter measuring device 8 on the downstream side. Yes. The heating furnace 2 includes a cylindrical furnace core tube 3 to which a glass base material G is supplied, and a heating element 4 surrounding the furnace core tube 3. Heating the heating element 4 raises the temperature of the core tube 3, and a heating region is formed in the inner space to heat and soften the glass base material G. The heating furnace 2 is provided with a gas supply unit 5 for supplying a purge gas such as helium or nitrogen to the heating region.

  The glass base material G is fed into the heating furnace 2 such that the upper support rod portion thereof is gripped by the feeding means 6 and the lower end portion thereof is positioned in the heating region inside the core tube 3. As described above, the glass base material G supplied into the heating furnace 2 is heated and softened at the lower end side in the heating region, and is drawn downward to be reduced in diameter to obtain a glass fiber G1.

  Below the heating furnace 2 (downstream side), a cooling device 7 using a cooling gas such as helium gas is provided, and the glass fiber G1 immediately after leaving the heating furnace 2 is forced by the cooling device 7. To be cooled. Thereby, the glass fiber G1 is rapidly cooled to near room temperature.

  Further, for example, a laser beam type outer diameter measuring device 8 is provided on the downstream side of the cooling device 7, and the outer diameter of the glass fiber G1 exiting the cooling device 7 is measured by the outer diameter measuring device 8. The outer diameter of the glass fiber G1 at the time of drawing is managed.

  On the downstream side of the glass fiber manufacturing apparatus 1, a die 9 for applying an ultraviolet curable resin to the glass fiber G1 and an ultraviolet irradiation apparatus 10 for curing the applied ultraviolet curable resin are sequentially provided. The glass fiber G1 that has passed through the die 9 and the ultraviolet irradiation device 10 is formed with an ultraviolet curable resin coating layer on the outer periphery thereof to form an optical fiber G2.

  Thereafter, the optical fiber G2 is drawn into the capstan 13 via the guide rollers 11 and 12, and sent to the take-up bobbin 17 via the screening device 14 and the dancer rollers 15 and 16, and taken up.

(Configuration of cooling device)
Next, the cooling device 7 constituting the glass fiber manufacturing apparatus 1 will be described.
FIG. 2 is a schematic cross-sectional view of the cooling device 7.

  As shown in FIG. 2, the cooling device 7 includes a cylindrical cooling pipe 21. The cooling pipe 21 is formed with an insertion passage 22 penetrating vertically. The cooling pipe 21 has an upper end as an inlet portion 21a and a lower end as an outlet portion 21b. The glass fiber G1 drawn from the glass base material G is drawn from the inlet portion 21a and pulled out from the outlet portion 21b. It is. That is, the glass fiber G1 that travels downstream in the drawing direction A is inserted through and passed through the cooling pipe 21 at substantially the center of the insertion passage 22.

  A cooling gas supply pipe 23 is connected to the cooling pipe 21 in the vicinity of its upper end, and the cooling gas is supplied from the cooling gas supply pipe 23 into the insertion path 22. As the cooling gas, helium gas having excellent thermal conductivity is used.

  The insertion passage 22 of the cooling pipe 21 is gradually narrowed toward the downstream side in the drawing direction A of the glass fiber G. That is, the cooling pipe 21 is formed such that the distance perpendicular to the drawing direction A between the inner surface 22a of the insertion path 22 and the glass fiber G1 passing through the insertion path 22 decreases toward the downstream side in the drawing direction A. ing.

  Specifically, in the cooling pipe 21, the distance perpendicular to the drawing direction A between the inner surface 22a of the insertion path 22 and the glass fiber G1 is the largest at the inlet 21a of the cooling pipe 21, and at the outlet 21b of the cooling pipe 21. Smallest. Further, the cooling pipe 21 is formed such that the distance perpendicular to the drawing direction A between the inner surface 22a of the insertion passage 22 and the glass fiber G1 gradually decreases from the inlet portion 21a of the cooling pipe 21 toward the outlet portion 21b. ing.

  The cooling pipe 21 of this example has, for example, a total length (length along the drawing direction A) of 5 m, an inner diameter of the inlet portion 21a of about 10 mm, an inner diameter of the outlet portion 21b of about 5 mm, and the insertion passage 22 extends from the inlet portion 21a. A tapered surface is formed such that the inner diameter is 10 mm to 5 mm toward the outlet 21 b.

  The glass fiber G1 passed through the insertion passage 22 of the cooling pipe 21 has an unconstrained section L in which the position from the lower end of the glass base material G to the die 9 for applying the resin is not restrained on the pass line. It is said that. On the other hand, the cooling pipe 21 is installed such that the inlet portion 21a having the maximum diameter of the insertion passage 22 is disposed closer to the central portion Lc in the unconstrained section L of the glass fiber G1 than the outlet portion 21b. ing.

(Cooling process of glass fiber)
In the cooling device 7 including such a cooling pipe 21, the drawn glass fiber G1 travels downstream in the drawing direction A through the insertion path 22 of the cooling pipe 21 to which the cooling gas is supplied from the vicinity of the upper end. pass. The glass fiber G1 is rapidly cooled to near room temperature by the cooling gas when passing through the insertion passage 22.

  At this time, in the insertion passage 22, a traction flow of the cooling gas from the upstream side in the drawing direction A to the downstream side is generated by the glass fiber G <b> 1 that travels downstream in the drawing direction A. Since the insertion path 22 of the cooling pipe 21 has a smaller inner diameter toward the downstream side, the cooling gas concentration on the downstream side is increased by the traction flow, the cooling efficiency is improved, and the glass fiber G1 is efficiently cooled.

  Further, the glass fiber G1 that is drawn and travels downstream at a high speed may vibrate in the unconstrained section L to cause a line runout, and the line runout is usually large near the central portion Lc of the unconstrained section L. Become. In the cooling pipe 21 of this example, the inlet portion 21a disposed at a position near the central portion Lc in the unconstrained section L of the glass fiber G1 is the maximum diameter of the insertion passage 22, and the inner surface 22a of the insertion passage 22 and the glass fiber G1. The distance perpendicular to the line drawing direction A is the largest. Therefore, contact with the inner surface 22a of the insertion path 22 of the glass fiber G1 which shakes is prevented.

As a comparison with the cooling pipe 21 of this example, FIG. 3 shows a cooling pipe having an insertion passage having the same inner diameter over the longitudinal direction.
In the cooling pipe 121 having the same inner diameter along the longitudinal direction shown in FIG. There is a high possibility that the glass fiber G1 is disconnected by coming into contact with the inner surface 122a of the insertion path 122 at a position near the central portion Lc of the unconstrained section L of the glass fiber G1 that becomes large.

  Therefore, in such a cooling pipe 121, in order to prevent disconnection due to contact with the inner surface 122a of the insertion path 122 of the glass fiber G1, it is necessary to design the inner diameter to a certain extent in the longitudinal direction. In that case, it becomes necessary to increase the amount of cooling gas used, or the cooling efficiency of the glass fiber G1 is limited.

  On the other hand, according to the cooling pipe 21 of the said embodiment, the distance orthogonal to the drawing direction A of the inner surface 22a of the insertion path 22 of the cooling pipe 21 and the glass fiber G1 goes to the downstream of the drawing direction A. Since it is small, it is possible to improve the cooling efficiency by increasing the concentration of the cooling gas while preventing the contact with the inner surface 22a of the insertion path 22 at the location where the linear fluctuation of the glass fiber G1 is large. Can be cooled to. Thereby, the glass fiber G1 can be efficiently cooled without causing problems such as disconnection. That is, a high-quality glass fiber G1 can be manufactured by drawing from the glass base material G, and further, a high-quality optical fiber G2 can be manufactured.

  In particular, the distance perpendicular to the drawing direction A between the inner surface 22a of the insertion passage 22 of the cooling pipe 21 and the glass fiber G1 is the largest at the inlet 21a of the cooling pipe 21 and the smallest at the outlet 21b of the cooling pipe 21. Thus, it is possible to improve the cooling efficiency on the outlet portion 21b side while suppressing the contact with the inner surface 22a of the insertion path 22 of the glass fiber G1 on the inlet portion 21a side more reliably.

  Further, the distance orthogonal to the drawing direction A between the inner surface 22a of the insertion passage 22 of the cooling pipe 21 and the glass fiber G1 gradually decreases from the inlet portion 21a of the cooling pipe 21 toward the outlet portion 21b of the cooling pipe 21. The flow of the cooling gas becomes smooth, and the cooling efficiency can be further improved while suppressing the fluctuation of the glass fiber G1.

  And according to this embodiment, compared with the case where the inner diameter of an inlet_port | entrance part is the same as this embodiment, and uses the cooling pipe 121 of the same internal diameter over the longitudinal direction of 5 m in total length, the disconnection frequency of the glass fiber G1 is worsened. Without this, the temperature of the glass fiber G1 at the outlet 21b of the cooling pipe 21 when helium was used at the same flow rate as the cooling gas could be lowered by 5 ° C.

Next, another embodiment of the cooling pipe will be described.
(Modification 1)
FIG. 4 is a schematic cross-sectional view of a cooling pipe according to Modification 1.
As illustrated in FIG. 4, the cooling pipe 21 </ b> A according to the first modification has the same outer diameter in the longitudinal direction. And also in this cooling pipe 21A, the distance orthogonal to the drawing direction A between the inner surface 22a of the insertion path 22 and the glass fiber G1 gradually decreases from the inlet portion 21a to the outlet portion 21b of the cooling pipe 21A. Is formed. As a result, in the cooling pipe 21A, the distance orthogonal to the drawing direction A between the inner surface 22a of the insertion path 22 and the glass fiber G1 is the largest at the inlet 21a of the cooling pipe 21A and the smallest at the outlet 21b of the cooling pipe 21A. It has become.

  Even when the cooling pipe 21A according to the first modification is used in place of the cooling pipe 21 of the manufacturing apparatus 1 described above, as in the case where the cooling pipe 21 is used, the glass fiber G1 is inserted at a location where the line runout is large. While preventing the contact with the inner surface 22a of the passage 22, the cooling gas concentration can be increased on the downstream side to improve the cooling efficiency.

(Modification 2)
FIG. 5 is a schematic cross-sectional view of a cooling pipe according to the second modification.
As shown in FIG. 5, the cooling pipe 21 </ b> B according to the modification 2 is configured by connecting a plurality of divided bodies 31 a and 31 b formed in a cylindrical shape along a drawing direction A of the glass fiber G <b> 1. Each of the divided bodies 31a and 31b has through holes 32a and 32b that gradually reduce in diameter toward the lower end side, and the cooling pipe 21B connects the divided bodies 31a and 31b to thereby form the through holes 32a and 32b. Communicate with each other to form an insertion passage 22.

  In the cooling pipe 21B, the inner diameter of the through hole 32a at the lower end of the upper divided body 31a is the same as the inner diameter of the through hole 32b at the upper end of the lower divided body 31b. Thereby, in this cooling pipe 21B, the distance orthogonal to the drawing direction A between the inner surface 22a of the insertion path 22 and the glass fiber G1 continuously changes at the connecting portions of the divided bodies 31a and 31b.

  Therefore, also in the cooling pipe 21B according to the modified example 2, the distance orthogonal to the drawing direction A between the inner surface 22a of the insertion path 22 and the glass fiber G1 is gradually decreased from the inlet portion 21a to the outlet portion 21b of the cooling pipe 21B. It is formed to become. As a result, in the cooling pipe 21B, the distance orthogonal to the drawing direction A between the inner surface 22a of the insertion path 22 and the glass fiber G1 is the largest at the inlet 21a of the cooling pipe 21B and the smallest at the outlet 21b of the cooling pipe 21B. It has become. A cooling gas supply pipe 23 is connected to the cooling pipe 21B in the vicinity of the upper ends of the respective divided bodies 31a and 31b, and the cooling gas is supplied into the insertion passage 22 from these cooling gas supply pipes 23.

  Even when the cooling pipe 21B according to the second modification is used in place of the cooling pipe 21 of the manufacturing apparatus 1, the glass fiber G1 has a large runout as in the case where the cooling pipes 21 and 21A are used. It is possible to improve the cooling efficiency by increasing the concentration of the cooling gas on the downstream side while preventing contact with the inner surface 22a of the insertion passage 22. In particular, since the cooling pipe 21B is configured by connecting the plurality of divided bodies 31a and 31b, the long cooling pipe 21B can be easily manufactured. Moreover, since cooling gas is supplied in the insertion path 22 from the upper end vicinity of each division body 31a, 31b, the improvement of further cooling efficiency can be aimed at. In addition, since the distance perpendicular to the drawing direction A between the inner surface 22a of the insertion passage 22 and the glass fiber G1 continuously changes at the connection part of the divided bodies 31a and 31b, the flow of the cooling gas in the insertion passage 22 is changed. It becomes easy to make smooth and can improve cooling efficiency.

(Modification 3)
FIG. 6 is a schematic cross-sectional view of a cooling pipe according to Modification 3.
As shown in FIG. 6, in the cooling pipe 21C according to the modification 3, a plurality of divided bodies 35a and 35b formed in a cylindrical shape are connected along the drawing direction A of the glass fiber G1 in the same manner as the cooling pipe 21B. Configured. In the cooling pipe 21C, for example, divided bodies 35a and 35b having the same shape are used. Each of the divided bodies 35a and 35b has through holes 36a and 36b that gradually decrease in diameter toward the lower end side, and the cooling pipe 21C connects the divided bodies 35a and 35b to thereby connect the through holes 36a and 36b. Communicate with each other to form an insertion passage 22.

  In the cooling pipe 21C, the inner diameter of the through hole 36a at the lower end of the upper divided body 35a is smaller than the inner diameter of the through hole 36b at the upper end of the lower divided body 35b. Thereby, in the cooling pipe 21 </ b> C, the change in the distance orthogonal to the drawing direction A between the inner surface 22 a of the insertion passage 22 and the glass fiber G <b> 1 is discontinuous at the connecting portion of the divided body 35. Although the cooling pipe 21C has this discontinuous portion, the distance perpendicular to the drawing direction A between the inner surface 22a of the insertion path 22 and the glass fiber G1 is the largest at the inlet portion 21a of the cooling pipe 21C, and the cooling pipe 21C It becomes smaller toward the downstream side, and is smallest at the outlet 21b of the cooling pipe 21C. In addition, a cooling gas supply pipe 23 is connected to the cooling pipe 21C in the vicinity of the upper ends of the respective divided bodies 35a and 35b similarly to the cooling pipe 21B.

  Even when the cooling pipe 21C according to the third modification is used in place of the cooling pipe 21 of the manufacturing apparatus 1 described above, the line vibration of the glass fiber G1 is substantially the same as when the cooling pipes 21, 21A, and 21B are used. The cooling efficiency can be improved by increasing the concentration of the cooling gas on the downstream side while preventing contact with the inner surface 22a of the insertion passage 22 at a large location. Further, similarly to the cooling pipe 21B, the long cooling pipe 21C can be easily manufactured, and the cooling efficiency can be further improved. In addition, by making the divided bodies 35a and 35b have the same shape, it is possible to reduce costs by sharing parts.

1: Manufacturing device 2: Heating furnace 3: Furnace core tube 4: Heating element 5: Gas supply unit 6: Feeding means 7: Cooling device 8: Outer diameter measuring device 9: Die 10: Ultraviolet irradiation device 11, 12: Guide roller 13 : Capstan 14: Screening device 15, 16: Dancer roller 17: Winding bobbins 21, 21 A, 21 B, 21 C, 121: Cooling pipe 21 a: Inlet part 21 b: Outlet part 22, 122: Insertion passage 23, 123: Cooling gas supply Tubes 22a, 122a: Inner surfaces 31a, 31b, 35a, 35b: Divided bodies 32a, 32b, 36a, 36b: Through holes A: Drawing direction G: Glass preform G1: Glass fiber G2: Optical fiber L: Unconstrained section Lc: Center

Claims (6)

A heating furnace that heats and softens the glass base material;
A cooling device for cooling the glass fiber drawn from the glass base material softened in the heating furnace,
The cooling device has a cylindrical cooling pipe having an insertion passage for allowing the glass fiber traveling in the drawing direction to pass therethrough and a cooling gas being supplied into the insertion passage,
The cooling pipe is a glass fiber manufacturing apparatus in which a distance perpendicular to the drawing direction between the inner surface of the insertion path and the glass fiber is smaller toward the downstream side in the drawing direction.   2. The cooling pipe according to claim 1, wherein a distance perpendicular to the drawing direction between the inner surface of the insertion passage and the glass fiber is the largest at the inlet of the cooling pipe and the smallest at the outlet of the cooling pipe. Glass fiber manufacturing equipment.   The distance between the inner surface of the insertion passage and the glass fiber that is perpendicular to the drawing direction of the cooling pipe gradually decreases from an inlet portion of the cooling pipe toward an outlet portion of the cooling pipe. The glass fiber manufacturing apparatus according to claim 2.   The said cooling pipe is a glass fiber manufacturing apparatus as described in any one of Claim 1 to 3 with which the several division body formed in the cylinder shape is connected along the said drawing direction.   The said cooling pipe manufactures the glass fiber of Claim 4 with which the distance orthogonal to the said drawing direction of the inner surface of the said insertion path and the said glass fiber is changing continuously in the connection part of the said division body. apparatus. A glass fiber is drawn from a glass base material that has been softened by heating, and the glass fiber that advances in the drawing direction is passed through the insertion passage of a cooling pipe having an insertion passage to which a cooling gas is supplied to cool the glass fiber. In the process,
The glass fiber manufacturing method, wherein a distance perpendicular to the drawing direction between the inner surface of the insertion passage of the cooling pipe and the glass fiber is reduced toward the downstream side in the drawing direction.

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