JP2020026371A - Manufacturing apparatus of optical fiber, and manufacturing method of optical fiber - Google Patents

Abstract

To provide a manufacturing apparatus of optical fiber and a manufacturing method of optical fiber capable of manufacturing high quality optical fiber while suppressing an equipment cost and a workload.SOLUTION: A manufacturing apparatus of optical fiber includes a heating furnace, a taking-in device, and a passage extension device. The heating furnace is installed on an upper floor of a three or more storied building and heats and extends optical fiber preform. The taking-in device is installed below the heating furnace on a floor lower than the upper floor and takes-in the optical fiber drawn out from the heated, extended optical fiber preform. The passage extension device is installed on at least one middle floor between the upper floor and the lower floor and changes the travel direction of the optical fiber traveling from the optical fiber preform to the taking-in device to the direction along the middle floor at a prescribed position on the middle floor and transfers the optical fiber at a prescribed distance and then turns the optical fiber back to the prescribed position and further changes the travel direction of the optical fiber to the direction toward the taking-in device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical fiber manufacturing apparatus and an optical fiber manufacturing method.

  Generally, an optical fiber is manufactured by heating and stretching an optical fiber preform made of glass in a heating furnace, and drawing vertically downward therefrom. The drawn-out optical fiber is taken out by a take-up device installed substantially vertically below the heating furnace, and thereafter, a coating made of a curable resin or the like is formed on the outer periphery thereof, and is taken up by a take-up device (Patent Document 1). . This step is also called a drawing step, and is performed using an optical fiber manufacturing apparatus.

  The optical fiber immediately after being drawn is hot because it is made of heated glass. Therefore, in order to adhere the resin to be coated on the outer periphery of the optical fiber in a good state, it is necessary to control the temperature of the optical fiber before attaching the resin. As a method of controlling the temperature of the optical fiber, there is a method of extending the time from drawing out the optical fiber to adhering the resin so that the temperature of the optical fiber is sufficiently lowered before adhering the resin. In order to realize this method, there is a method of reducing the drawing speed of the optical fiber. However, if the drawing speed is reduced, the manufacturability of the optical fiber is reduced.

  As another method for sufficiently lowering the temperature of the optical fiber in the time until the resin is applied, there is also a method in which the path along which the optical fiber travels from the extraction to the application of the resin is lengthened. However, if the method of increasing the height of the building where the optical fiber manufacturing equipment is installed is adopted in order to lengthen the route, for example, it is necessary to newly build or expand the building, which makes the facility cost difficult. is there.

  On the other hand, there has been disclosed a method of controlling the temperature of an optical fiber before resin is attached by cooling the optical fiber. When the optical fiber is rapidly cooled, the transmission loss of the optical fiber may increase. Therefore, in order to suppress an increase in transmission loss, a method has been disclosed in which a drawn optical fiber is annealed in a heat treatment furnace and then cooled forcibly (Patent Document 2).

  Further, a method has been disclosed in which the direction in which the optical fiber travels is changed by a direction changer to lengthen the path along which the optical fiber travels (Patent Documents 3 and 4). According to these techniques, the path can be lengthened in a building having a limited height. For example, in Patent Literature 3, after the optical fiber is once advanced downward, the optical fiber is advanced upward one or more times, or left or right in the middle thereof. Heating and cooling are performed in the middle of this route.

JP 2003-146708 A Japanese Patent No. 4244925 US Patent Application Publication No. 2017/0073265 JP 2017-160059 A

  However, the techniques disclosed in Patent Documents 3 and 4 still have room for improvement. For example, when the traveling direction of an optical fiber is changed in the up and down direction as in Patent Document 3, it is necessary to alternately route the tip of the drawn optical fiber to the up and down direction changer, particularly in the initial stage of the drawing process. Become. When this operation is performed by an operator, the operator needs to perform a complicated operation of ascending and descending the inside of the building using ascending / descending means such as stairs and maneuvering. In Patent Literature 3, the optical fiber is advanced in the left and right direction in the chamber. However, since the optical fiber is in the chamber, the extension of the path is limited. In the case where the traveling direction of the optical fiber is changed as in Patent Literature 4, the position where the optical fiber travels downward on the upper and lower sides of the direction changer is shifted in a horizontal plane. As a result, it is necessary to significantly remodel the existing manufacturing equipment or newly install a manufacturing equipment, such as re-installing or newly installing a portion below the direction changer. Therefore, there is difficulty in terms of equipment costs.

  The present invention has been made in view of the above, and an object of the present invention is to provide an optical fiber manufacturing apparatus and an optical fiber manufacturing method capable of manufacturing a high-quality optical fiber while suppressing equipment costs and work load. It is in.

  In order to solve the above-described problem and achieve the object, an optical fiber manufacturing apparatus according to one embodiment of the present invention is installed on an upper floor of a building having three or more floors and heats and draws an optical fiber preform. And a take-off device installed below the heating furnace in a lower floor below the upper floor and for taking out an optical fiber drawn from the heated and stretched optical fiber preform, wherein the upper floor and the lower floor Installed on at least one middle floor positioned between the optical fiber preform and the drawing direction of the optical fiber in the process of being taken by the take-off device, at a predetermined position in the middle floor, along the floor of the middle floor. After the optical fiber is advanced by a predetermined distance, then turned back toward the predetermined position, and then further converted the traveling direction of the optical fiber to a direction toward the take-off device. A path extending unit that, characterized in that it comprises a.

  An apparatus for manufacturing an optical fiber according to one aspect of the present invention includes at least one temperature control device that is installed on at least one of the middle floors and controls a temperature of the optical fiber that travels in a direction along the floor. It is characterized by the following.

  An apparatus for manufacturing an optical fiber according to one embodiment of the present invention is characterized in that at least one of the temperature control devices heats the optical fiber.

  An apparatus for manufacturing an optical fiber according to one aspect of the present invention is characterized in that at least one of the temperature control devices cools the optical fiber.

  An apparatus for manufacturing an optical fiber according to one aspect of the present invention includes a plurality of the temperature control devices, wherein the plurality of temperature control devices are configured such that the temperature of the optical fiber is higher on the side of the take-off device than on the side of the optical fiber preform. It is characterized by being installed so as to be lower.

  The optical fiber manufacturing apparatus according to an aspect of the present invention includes a coating forming apparatus that forms a coating on the outer periphery of the optical fiber between the path extending device and the take-off device in the optical fiber path. Features.

  An apparatus for manufacturing an optical fiber according to one aspect of the present invention includes a protective film forming a heat-resistant protective layer around the optical fiber between the heating furnace and the path extending device in the optical fiber path. A device is provided.

  An apparatus for manufacturing an optical fiber according to one aspect of the present invention, wherein the path extending device is configured to convert the traveling direction of the optical fiber a plurality of times in a direction along the floor of the middle floor. Features.

  The method for manufacturing an optical fiber according to one aspect of the present invention is a step of heating and stretching an optical fiber preform on the upper floors of three or more floors of the building, and on the lower floor below the upper floor, the heating and stretching are performed. Taking the optical fiber drawn from the optical fiber preform, wherein at least one middle floor located between the upper floor and the lower floor, the light is being taken from the optical fiber preform. The traveling direction of the fiber is converted from a predetermined position on the middle floor to a direction along the floor of the middle floor, and after traveling the optical fiber by a predetermined distance, the optical fiber is turned back toward the predetermined position, and then further It is characterized in that the traveling direction of the optical fiber is converted to the direction in which it is pulled.

  The method for manufacturing an optical fiber according to one aspect of the present invention is characterized in that at least one of the middle floors controls the temperature of the optical fiber traveling in a direction along the floor.

  A method for manufacturing an optical fiber according to one embodiment of the present invention is characterized in that at least one of heating and cooling is performed on the optical fiber.

  The method for manufacturing an optical fiber according to one aspect of the present invention is characterized in that the temperature of the optical fiber is controlled such that the temperature is lower on the side where the optical fiber is drawn than on the side of the optical fiber preform.

  The method for manufacturing an optical fiber according to one aspect of the present invention includes forming a coating on the outer periphery of the optical fiber between the time when the traveling direction of the optical fiber is changed to the direction in which the optical fiber is pulled and the time when the optical fiber is pulled. Features.

  The method for manufacturing an optical fiber according to one aspect of the present invention is characterized in that a heat-resistant protective layer is formed on the outer periphery of the optical fiber before changing the traveling direction of the optical fiber.

  The method for manufacturing an optical fiber according to one aspect of the present invention is characterized in that a traveling direction of the optical fiber is changed a plurality of times in a direction along the floor of the middle floor.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that a high quality optical fiber can be manufactured, suppressing equipment cost and work load.

FIG. 1 is a schematic diagram illustrating a configuration of an optical fiber manufacturing apparatus according to an embodiment and a manufacturing method using the same. FIG. 2 is a schematic view showing an example of another manufacturing method using the optical fiber manufacturing apparatus shown in FIG. FIG. 3 is a schematic diagram illustrating a first modification of the route extension device and the temperature control device. FIG. 4 is a schematic diagram illustrating a second modification of the route extension device and the temperature control device. FIG. 5 is a schematic diagram illustrating a third modification of the route extension device. FIG. 6 is a schematic diagram illustrating a fourth modification of the route extension device. FIG. 7 is a schematic diagram illustrating a modification of the optical fiber manufacturing apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited by the embodiments described below. In the drawings, the same or corresponding components are denoted by the same reference numerals as appropriate. In addition, xyz coordinate axes are appropriately shown in the drawings, and the directions will be described accordingly.

  FIG. 1 is a schematic diagram illustrating a configuration of an optical fiber manufacturing apparatus according to an embodiment and a manufacturing method using the same. The optical fiber manufacturing apparatus 100 (hereinafter, appropriately referred to as manufacturing apparatus 100) is installed in the building B. The building B is a building having three or more floors including a first floor L1, a second floor L2, a third floor L3, a fourth floor L4, and a fifth floor L5. Each floor has floors F1, F2, F3, F4, and F5 that extend substantially parallel to the xy plane. The xy plane is a horizontal plane, and the + z direction is vertically downward.

  The manufacturing apparatus 100 includes a heating furnace 10, path extension devices 20, 30, and 40, a lower device 50, and temperature controllers 61, 62, and 63.

  The heating furnace 10 is installed on the fifth floor L5, which is the upper floor. The heating furnace 10 is a heating furnace having a known structure having a heater 11. In the heating furnace 10, an optical fiber preform P made of a known quartz glass or the like is set, and this is heated and stretched. Thereby, the optical fiber OF1, which is a glass optical fiber, is drawn out. The glass optical fiber is an optical fiber in a state where the whole is made of glass before a coating is formed on the outer periphery.

  The lower device 50 is installed on the first floor L1, which is a lower floor below the fifth floor L5. The lower device 50 includes a coating forming device 51, a take-up device 52, and a winding device 53.

  The coating forming apparatus 51 is installed substantially vertically below the heating furnace 10 and is disposed between the path extending apparatus 40 and the take-up apparatus 52 in the path of the optical fiber OF1. The coating forming device 51 is a device that forms a coating on the outer periphery of the optical fiber OF1 drawn from the optical fiber preform P between the path extending device 40 and the take-off device 52, thereby forming a coated optical fiber OF2. . The coating forming device 51 is a known device that includes, for example, a resin coating device that applies an ultraviolet curable resin to the outer periphery of the optical fiber OF1, and an ultraviolet light source that cures the applied ultraviolet curable resin and coats the resin. is there.

  The take-off device 52 is installed substantially vertically below the heating furnace 10 and the coating forming device 51. The take-off device 52 has a coating formed on the optical fiber OF1 drawn from the optical fiber preform P and pulls the optical fiber OF2 downward. The take-up device 52 is a known device including a take-up roller and a drive source that drives the take-up roller to rotate. The traveling direction of the optical fiber OF2 taken by the take-up device 52 is changed to the direction in which it travels to the take-up device 53 installed at another position on the fifth floor L5.

  Each of the floors F1, F2, F3, F4, and F5 has a through hole for the optical fiber OF1 to travel downward (+ z direction) from the heating furnace 10 to the take-off device 52.

  The winding device 53 is a device that winds the optical fiber OF2 around a winding bobbin, and is a known device that includes a drive source that rotationally drives the winding bobbin. A guide roll for guiding the optical fiber OF2 from the take-up device 52 to the take-up device 53 is appropriately provided between the take-up device 52 and the take-up device 53.

  The route extension devices 20, 30, and 40 are respectively installed on the fourth floor L4, the third floor L3, and the second floor L2, which are middle floors located between the upper floor and the lower floor.

  The path extension device 20 has direction changers 21, 22, and 23. After being pulled out of the optical fiber preform P, the optical fiber OF1 passes through the through hole of the floor F5 and reaches the direction changer 21 on the fourth floor L4. The direction changer 21 changes the traveling direction of the optical fiber OF1 in the middle of being taken from the optical fiber preform P by the take-up device 52 to a direction along the floor F4 at a predetermined position on the fourth floor L4. In the present embodiment, the direction changer 21 changes the traveling direction of the optical fiber OF1 from the + z direction to a direction along the + x direction. Here, the direction along the floor includes not only a direction parallel to the floor but also a direction inclined to some extent with respect to the floor. Similarly, the direction along a certain direction includes not only a direction parallel to the certain direction but also a direction inclined to some extent with respect to the certain direction.

  The direction converter 22 is arranged at a position spaced apart from the direction converter 21 in the + x direction. The direction changer 21 and the direction changer 22 advance the optical fiber OF1 by a first predetermined distance. The direction changer 22 changes the traveling direction of the optical fiber OF1 from the + x direction to the −x direction, and turns back toward the predetermined position.

  The direction changer 23 is installed below the direction changer 22. The direction converter 23 converts the traveling direction of the optical fiber OF1 into a direction toward the take-off device 52 (+ z direction). The position at which the direction changer 23 changes the traveling direction of the optical fiber OF1 is preferably directly below the predetermined position at which the direction changer 21 changes the direction of travel of the optical fiber OF1, but the take-off device 52 is As long as the fiber OF1 can be pulled, the fiber OF1 may be shifted horizontally with respect to the predetermined position. Thereafter, the optical fiber OF1 passes through a through hole formed in the floor F4 and proceeds to the third floor L3.

  The route extension device 30 has direction changers 31, 32, and 33. The direction changer 31 is installed below the direction changer 23, and changes the traveling direction of the optical fiber OF1 into a direction along the floor F3 at a predetermined position on the third floor L3. In the present embodiment, the direction changer 31 changes the traveling direction of the optical fiber OF1 from the + z direction to a direction along the + x direction.

  The direction changer 32 is arranged at a position separated from the direction changer 31 in the + x direction. The direction changer 31 and the direction changer 32 advance the optical fiber OF1 by a second predetermined distance. The direction changer 32 changes the traveling direction of the optical fiber OF1 from the + x direction to the −x direction, and turns back toward the predetermined position.

  The direction changer 33 is installed below the direction changer 32. The direction converter 33 converts the traveling direction of the optical fiber OF1 into a direction toward the take-off device 52 (+ z direction). The position at which the direction changer 33 changes the traveling direction of the optical fiber OF1 is preferably immediately below the predetermined position at which the direction changer 31 changes the direction of travel of the optical fiber OF1, but the take-off device 52 is As long as the fiber OF1 can be pulled, the fiber OF1 may be shifted horizontally with respect to the predetermined position. Thereafter, the optical fiber OF1 passes through a through hole formed in the floor F3 and proceeds to the second floor L2.

  The route extension device 40 has direction changers 41, 42, 43. The direction converter 41 converts the traveling direction of the optical fiber OF1 into a direction along the floor F2 at a predetermined position on the second floor L2. In the present embodiment, the direction changer 41 changes the traveling direction of the optical fiber OF1 from the + z direction to a direction along the + x direction.

  The direction changer 42 is arranged at a position separated from the direction changer 41 in the + x direction. The direction changer 41 and the direction changer 42 advance the optical fiber OF1 by a third predetermined distance. The direction changer 42 changes the traveling direction of the optical fiber OF1 from the + x direction to the −x direction, and turns back toward the predetermined position.

  The direction changer 43 is installed below the direction changer 42. The direction converter 43 converts the traveling direction of the optical fiber OF1 into a direction toward the take-off device 52 (+ z direction). The position at which the direction changer 43 changes the traveling direction of the optical fiber OF1 is preferably immediately below the predetermined position at which the direction changer 41 changes the direction of travel of the optical fiber OF1, but the take-off device 52 is As long as the fiber OF1 can be pulled, the fiber OF1 may be shifted horizontally with respect to the predetermined position. Thereafter, the optical fiber OF1 passes through a through hole formed in the floor F2 and proceeds to the lower device 50 on the first floor L1.

  The direction changers 21, 22, 23, 31, 32, 33, 41, 42, and 43 change the traveling direction of the optical fiber OF <b> 1 which is a glass optical fiber so as not to break. As the direction changers 21, 22, 23, 31, 32, 33, 41, 42, and 43, those having a fluid bearing shown in Patent Document 3 and a mechanism for floating the optical fiber OF1 by a fluid shown in Patent Document 4 are described. For example, a non-contact type can be adopted. Further, a guide roll made of a soft material that does not break even when the optical fiber OF1 comes into contact with the optical fiber OF1 or a material that allows the optical fiber OF1 to smoothly slide on its surface is provided. The optical fiber OF1 is brought into contact with the guide roll. A direction changer having a mechanism for changing the traveling direction may be employed.

  Next, the temperature control devices 61, 62 and 63 will be described. The temperature control device 61 is installed between the direction changers 21 and 23 and the direction changer 22 on the fourth floor L4. The temperature control device 61 controls the temperature of the optical fiber OF1 traveling between the direction changers 21 and 23 and the direction changer 22 in the direction along the floor F4. The temperature control device 62 is installed between the direction changers 31 and 33 and the direction changer 32 on the third floor L3. The temperature control device 62 controls the temperature of the optical fiber OF1 traveling between the direction changers 31 and 33 and the direction changer 32 in the direction along the floor F3. The temperature control device 63 is installed between the direction changers 41 and 43 on the second floor L2 and the direction changer 42. The temperature control device 63 controls the temperature of the optical fiber OF1 traveling between the direction changers 41 and 43 and the direction changer 42 in the direction along the floor F2.

  The temperature control device 61 controls the temperature of the optical fiber OF1 to be lower than the heating furnace 10 and higher than room temperature. The temperature control device 61 is, for example, an annealing furnace having a known configuration capable of heating and annealing the optical fiber OF1. The temperature control device 62 controls the temperature of the optical fiber OF1 to be lower than the temperature control device 61 and higher than the room temperature. The temperature control device 62 is, for example, a cooling passage having a known configuration that can naturally cool the optical fiber OF1. The temperature control device 63 controls the temperature of the optical fiber OF1 to be lower than the temperature control device 62 and higher than the room temperature. The temperature control device 63 is, for example, a cooling device having a known configuration that can forcibly cool the optical fiber OF1. Each of the temperature control devices 61, 62, and 63 may have a temperature gradient in the longitudinal direction. As described above, the temperature control devices 61, 62, and 63 are installed such that the temperature of the optical fiber OF1 is lower on the take-up device 52 side than on the optical fiber preform P side.

  The process of manufacturing the optical fiber OF2 by the manufacturing apparatus 100 will be described below. In this manufacturing process, the heating furnace 10 installed on the fifth floor L5 heats and stretches the optical fiber preform P. Then, in the lower device 50 installed on the first floor L1, the coating forming device 51 forms a coating on the outer periphery of the optical fiber OF1 drawn from the optical fiber preform P, and the take-off device 52 moves the optical fiber OF2 downward. And the winding device 53 winds the optical fiber OF2.

  At this time, in each of the path extension devices 20, 30, and 40 installed on the fourth floor L4, the third floor L3, and the second floor L2, the traveling direction of the optical fiber OF1 is converted into a direction along the floor of each floor. I do. Then, after the optical fiber OF1 is advanced by a predetermined distance, the optical fiber OF1 is turned back. Then, the traveling direction is changed to a direction toward the take-off device 52.

  In the manufacturing apparatus 100, the take-off apparatus 52 is installed substantially vertically below the heating furnace 10, and has the same structure as the existing manufacturing apparatus. Therefore, the present invention can be implemented without the need to significantly modify an existing manufacturing apparatus or newly install a manufacturing apparatus, so that equipment costs can be reduced. Then, the traveling direction of the optical fiber in the middle of being taken from the optical fiber preform P to the take-up device 52 is changed, and the traveling direction is made along the respective floors of the fourth floor L4, the third floor L3, and the second floor L2, which are the middle floors. After turning back, the traveling direction is again changed to the direction toward the take-off device 52. Thereby, the path of the optical fiber OF1 can be easily lengthened. In addition, the manufacturing apparatus 100 can be configured by simply adding a path extension device to each middle floor of the existing manufacturing apparatus, so that equipment costs can be reduced. Further, taking the fourth floor L4 as an example, in the early stage of the drawing process, when the worker performs the work of routing the leading end of the drawn optical fiber OF1 to the direction changers 21, 22, and 23, the worker simply has to work on the fourth floor. Since it is only necessary to move the floor F4 in L4 to perform the handling, the work is easy and the work load is greatly reduced. Further, since the path of the optical fiber OF1 from the heating furnace 10 to the coating forming apparatus 51 is lengthened, a high quality coating can be formed in the coating forming apparatus 51. Furthermore, since the length of the path can appropriately control the temperature of the optical fiber OF1, it is possible to suppress an increase in transmission loss. In the present embodiment, the temperature of the optical fiber OF1 can be more appropriately controlled by the temperature control devices 61, 62, and 63. Therefore, it is possible to suppress the increase in the transmission loss while increasing the drawing speed to improve the manufacturability. it can. The temperature control by the temperature control devices 61, 62, and 63 can be appropriately designed from the viewpoint of increasing the drawing speed and suppressing the increase in transmission loss.

  As described above, according to the manufacturing apparatus 100, a high-quality optical fiber OF2 can be manufactured while suppressing the equipment cost and the work load, and the manufacturability can be increased.

  In the above description, an annealing furnace is illustrated as the temperature control device 61, a cooling path is illustrated as the temperature control device 62, and a cooling device is illustrated as the temperature control device 63. However, the combination of the configurations of the temperature control devices 61, 62, and 63 is not limited to the above examples as long as the temperature in the path of the optical fiber OF1 can be appropriately adjusted.

  FIG. 2 is a schematic diagram illustrating an example of another manufacturing method using the manufacturing apparatus 100. Here, the direction changers 21, 23, 31, 33, 41, and 43 are configured to be retractable from a path from the heating furnace 10 to the take-off device 52. In the case of FIG. 2, the direction changers 31, 33, 41, and 43 are retracted in the + x direction from the position shown in FIG.

  In the case of FIG. 2, only the path extension device 20 and the temperature control device 61 are used for manufacturing as the path extension device and the temperature control device. As in this example, the routes installed in at least one of the route extending devices 20, 30, 40 and the temperature control devices 61, 62, 63 on the fourth floor L4, the third floor L3, and the second floor L2, which are the middle floors. An extension device and a temperature control device may be used as appropriate. Further, the optical fiber OF1 drawn from the optical fiber preform P is directly advanced to the coating forming device 51 without using any of the path extending device and the temperature control device, and the coating is formed to manufacture the optical fiber OF2. May be. The drawing speed and the operating conditions of the coating forming apparatus 51 are adjusted so that a high quality coating is formed on the optical fiber OF1 in the coating forming apparatus 51 according to the number of use of the path extending apparatus and the temperature control apparatus and the temperature control state. Is preferred.

  Further, as an example of another manufacturing method using the manufacturing apparatus 100, at least one of the path extending apparatuses 20, 30, and 40 is used to lengthen the path of the optical fiber OF1, but the temperature control apparatuses 61, 62, The operation of 63 can be stopped and used. In this case, the optical fiber OF1 is mainly naturally cooled. Also in this case, it is preferable to adjust the drawing speed and the operating conditions of the coating forming apparatus 51 so that a good-quality coating is formed on the optical fiber OF1 in the coating forming apparatus 51.

(Modification)
FIG. 3 is a schematic diagram illustrating a first modification of the path extension device and the temperature control device applicable to the manufacturing apparatus 100. In the first modification, the direction change device 22 of the route extension device 20 installed on the fourth floor L4 of the manufacturing apparatus 100 is replaced with two direction change devices 22a and 22b, and the temperature control device 61 is replaced with three temperature control devices. The devices are replaced by devices 61a, 61b and 61c.

  The direction changer 22a is arranged at a position separated from the direction changer 21 on the fourth floor L4. The direction changer 21 and the direction changer 22a advance the optical fiber OF1 by a fourth predetermined distance along the floor F4. The direction changer 22a changes the traveling direction of the optical fiber OF1 along the floor F4 and in a direction different from the traveling direction between the direction changer 21 and the direction changer 22a. More specifically, the direction changer 22a changes the traveling direction of the optical fiber OF1 to a direction toward the direction changer 22b disposed at a distance from the optical fiber OF1. The direction changers 22a and 22b advance the optical fiber OF1 by a fifth predetermined distance.

  The direction changer 22 b changes the traveling direction of the optical fiber OF <b> 1 into a direction along the floor F <b> 4 and toward the direction changer 23. That is, the direction changers 22a and 22b change the traveling direction of the optical fiber OF1 twice, which is a plurality of times, and turn the optical fiber OF1 traveling from the direction changer 21 back toward the direction changer 23. By changing the traveling direction of the optical fiber OF1 a plurality of times on the same floor in this manner, the path of the optical fiber OF1 can be made longer on a single floor.

  The temperature controller 61a is disposed between the direction changer 21 and the direction changer 22a, and controls the temperature of the optical fiber OF1 traveling along the floor F4. The temperature control device 61b is disposed between the direction changers 22a and 22b, and controls the temperature of the optical fiber OF1 traveling along the floor F4. The temperature control device 61c is arranged between the direction changer 22b and the direction changer 23, and controls the temperature of the optical fiber OF1 traveling along the floor F4. The temperature control devices 61a, 61b, and 61c control the optical fiber OF1 at different temperatures, but it is preferable to control the temperature of the temperature control devices 61a, 61b, and 61c such that the temperatures become lower in this order. As described above, by controlling the optical fibers OF1 to different temperatures on the same floor, finer temperature control can be performed on a single floor. For example, by using the temperature control device 61a as an annealing furnace, the temperature control device 61b as a cooling path, and the temperature control device 61c as a cooling device, a single floor is equivalent to the temperature control devices 61, 62, and 63 in FIG. Temperature control.

  FIG. 4 is a schematic diagram illustrating a second modification of the path extension device and the temperature control device applicable to the manufacturing apparatus 100. In this modified example 2, the direction change device 22 included in the route extension device 20 installed on the fourth floor L4 in the manufacturing apparatus 100 is replaced with three direction change devices 22c, 22d, and 22e, and the temperature control device 61 is replaced with four The temperature controllers 61d, 61e, 61f, and 61g are replaced.

  In the second modification, the direction of travel of the optical fiber OF1 is changed three times by the direction changers 22c, 22d, and 22f arranged apart from each other, and the direction of the optical fiber OF1 traveling from the direction changer 21 is changed. Turn it back toward the container 23. By changing the traveling direction of the optical fiber OF1 a plurality of times on the same floor in this manner, the path of the optical fiber OF1 can be made longer on a single floor.

  The temperature control device 61d is disposed between the direction changer 21 and the direction changer 22c, and controls the temperature of the optical fiber OF1. The temperature control device 61e is arranged between the direction changers 22c and 22d, and controls the temperature of the optical fiber OF1. The temperature control device 61f is arranged between the direction changer 22d and the direction changer 22e, and controls the temperature of the optical fiber OF1. The temperature control device 61f is arranged between the direction changer 22d and the direction changer 22e, and controls the temperature of the optical fiber OF1. The temperature control device 61g is arranged between the direction changer 22e and the direction changer 23, and controls the temperature of the optical fiber OF1. The temperature control devices 61d, 61e, 61f, and 61g control the optical fiber OF1 at different temperatures, but it is preferable that the temperature control devices 61d, 61e, 61f, and 61g be controlled so that the temperatures become lower in this order. As described above, by controlling the optical fibers OF1 to different temperatures on the same floor, finer temperature control can be performed on a single floor. For example, by using the temperature control device 61d as an annealing furnace, the temperature control device 61e as a second annealing furnace, the temperature control device 61f as a cooling path, and the temperature control device 61g as a cooling device, a single floor can be used. It is possible to perform finer temperature control than the one temperature control device 61, 62, 63.

  FIG. 5 is a schematic diagram illustrating a third modification of the route extension device. In the third modification, the direction change device 22 included in the route extension device 20 installed on the fourth floor L4 of the manufacturing apparatus 100 is replaced with a direction change device 22f. Although not shown, the temperature control device 61 is arranged between the direction changers 21 and 23 and the direction changer 22f.

  The direction changer 22f has a columnar shape whose central axis is parallel to the z direction, and is configured so that the optical fiber OF1 can be wound many times. The direction changer 22 f continuously changes the traveling direction of the optical fiber OF <b> 1 traveling from the direction changer 21, and turns back toward the direction changer 23. By using the direction changer 22f having such a configuration, the path of the optical fiber OF1 can be lengthened.

  FIG. 6 is a schematic diagram illustrating a fourth modification of the route extension device. In the fourth modification, the direction change device 22 included in the route extension device 20 installed on the fourth floor L4 of the manufacturing apparatus 100 is replaced with a direction change device 22g. Although not shown, the temperature control device 61 is disposed between the direction changers 21 and 23 and the direction changer 22g.

  The direction changer 22g has a polygonal column shape (a quadrangular column shape in the illustrated example) whose central axis is parallel to the z direction, and is configured to be able to wind the optical fiber OF1 a large number of times. The direction changer 22 g changes the traveling direction of the optical fiber OF <b> 1 traveling from the direction changer 21 a plurality of times, and turns the direction toward the direction changer 23. By using the direction changer 22g having such a configuration, the path of the optical fiber OF1 can be lengthened. The direction changer 22g may have another polygonal column shape such as a triangular prism shape or a hexagonal prism shape.

  The central axes of the direction changers 22f and 22g are not limited to being parallel to the z direction, and can be set in various directions. Further, the direction changers 22f and 22g may be rotated with the center axis as a rotation axis.

  3 to 6 may be applied to a route extension device and a temperature control device installed on the third floor L3 or the second floor L2 in the manufacturing apparatus 100.

  FIG. 7 is a schematic diagram illustrating a modification of the optical fiber manufacturing apparatus. The manufacturing apparatus 100A has a configuration in which a protective film forming apparatus 70 is added to the manufacturing apparatus 100.

  The protective film forming apparatus 70 is disposed between the heating furnace 10 and the first direction changer 21 in the path of the optical fiber OF1. The protective film forming apparatus 70 is an apparatus that forms a heat-resistant protective layer around the optical fiber OF1 before the direction changer 21 changes the traveling direction of the optical fiber OF1.

  By forming such a protective film, it is possible to reduce the possibility that the optical fiber OF1 is damaged when changing the traveling direction of the optical fiber OF1. Since the optical fiber OF1 has a high temperature after coming out of the heating furnace 10, the protective layer has heat resistance enough to withstand the high temperature.

  As the protective film forming apparatus 70, an apparatus that sprays a sol made of, for example, TEOS (tetraethyl orthosilicate) onto the outer periphery of the optical fiber OF1 to form a protective layer made of silica glass gel can be used. The coating may be formed on the outer periphery of the protective layer by the coating forming apparatus 51 as it is. Alternatively, after passing through the last direction changer 43 in the path of the optical fiber OF1, the protective layer may be removed before the coating is formed by the coating forming apparatus 51. As a method of removing the protective layer, a method of spraying a fluid such as a gas or a liquid onto the protective layer and blowing off the protective layer or a method of passing the stored liquid through the protective layer and dissolving and removing the protective layer is used. Etc. can be adopted as appropriate.

  In the above embodiment, the middle floors include the second floor L2, the third floor L3, and the fourth floor L4. However, the number of middle floors is not limited to this, and may be one or more.

  Further, the present invention is not limited by the above embodiments. The present invention also includes a configuration in which the above-described components are appropriately combined. Further, further effects and modified examples can be easily derived by those skilled in the art. Therefore, the broader aspects of the present invention are not limited to the above embodiments, and various modifications are possible.

10 Heating Furnace 11 Heater 20, 30, 40 Path Extension Device 21, 22, 22a, 22b, 22c, 22d, 22e, 22f, 22g, 23, 31, 32, 33, 41, 42, 43 Direction Converter 50 Lower Device Reference Signs List 51 coating forming device 52 take-up device 53 winding device 61, 61a, 61b, 61c, 61d, 61e, 61f, 61g, 62, 63 temperature control device 70 protective film forming device 100, 100A manufacturing device B building F1, F2, F3 , F4, F5 Floor L1 1st floor L2 2nd floor L3 3rd floor L4 4th floor L5 5th floor OF1, OF2 Optical fiber P Optical fiber preform

Claims (15)

A heating furnace installed on the upper floor of a building of three or more floors for heating and stretching an optical fiber preform;
A take-up device that is installed below the heating furnace in a lower floor below the upper floor and that pulls an optical fiber drawn from the heated and stretched optical fiber preform,
The traveling direction of the optical fiber, which is installed on at least one middle floor located between the upper floor and the lower floor and is being taken from the optical fiber preform to the take-up device, is a predetermined position on the middle floor. In the above, the direction is converted into a direction along the floor of the middle floor, and after the optical fiber is advanced by a predetermined distance, the optical fiber is turned back toward the predetermined position, and then the optical fiber is further advanced in the direction toward the take-off device. A path extension device that converts the
An optical fiber manufacturing apparatus, comprising:   The optical fiber according to claim 1, further comprising at least one temperature control device installed on at least one of the middle floors and controlling a temperature of the optical fiber traveling in a direction along the floor. manufacturing device.   The optical fiber manufacturing apparatus according to claim 2, wherein at least one of the temperature control devices heats the optical fiber.   The optical fiber manufacturing apparatus according to claim 2, wherein at least one of the temperature control devices cools the optical fiber.   A plurality of the temperature control devices, wherein the plurality of temperature control devices are installed such that the temperature of the optical fiber is lower on the side of the take-off device than on the side of the optical fiber preform. Item 5. An apparatus for manufacturing an optical fiber according to any one of Items 2 to 4.   The coating device according to any one of claims 1 to 5, further comprising a coating forming device that forms a coating on an outer periphery of the optical fiber, between the path extending device and the take-off device in the optical fiber path. An optical fiber manufacturing apparatus according to the above.   A protective film forming apparatus for forming a heat-resistant protective layer on the outer periphery of the optical fiber, between the heating furnace and the path extending device in the optical fiber path, is provided. The optical fiber manufacturing apparatus according to any one of the above.   The route extension device according to any one of claims 1 to 7, wherein the traveling direction of the optical fiber is changed a plurality of times in a direction along the floor of the middle floor. An optical fiber manufacturing apparatus according to the above. A step of heating and stretching the optical fiber preform on the upper floors of the third or higher building;
On the lower floor below the upper floor, a step of taking out the optical fiber drawn from the heated and drawn optical fiber preform,
Including
In at least one middle floor located between the upper floor and the lower floor, the traveling direction of the optical fiber being taken from the optical fiber preform is changed from a predetermined position in the middle floor to the middle floor. An optical fiber, wherein the optical fiber is converted into a direction along the floor, the optical fiber is advanced by a predetermined distance, then turned back toward the predetermined position, and then further converted into a direction in which the optical fiber is advanced. Manufacturing method.   The method for manufacturing an optical fiber according to claim 9, wherein a temperature of the optical fiber traveling in a direction along the floor is controlled on at least one of the middle floors.   The method according to claim 10, wherein at least one of heating and cooling is performed on the optical fiber.   The method of manufacturing an optical fiber according to claim 10, wherein the temperature of the optical fiber is controlled such that the temperature is lower on a side where the optical fiber is drawn than on a side of the optical fiber preform.   The method according to any one of claims 10 to 12, wherein a coating is formed on the outer periphery of the optical fiber during a period from when the traveling direction of the optical fiber is changed to a direction in which the optical fiber is pulled and before the optical fiber is pulled. The manufacturing method of the optical fiber described in the above.   14. The method of manufacturing an optical fiber according to claim 10, wherein a heat-resistant protective layer is formed on an outer periphery of the optical fiber before changing a traveling direction of the optical fiber.   The method according to any one of claims 10 to 14, wherein the traveling direction of the optical fiber is changed a plurality of times in a direction along the floor of the middle floor.

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