JP6887207B2 - Optical fiber manufacturing equipment and optical fiber manufacturing method - Google Patents

Description

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

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

The optical fiber immediately after being drawn out is hot because it consists of heated glass. Therefore, in order to adhere the coating resin to 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 lengthening the time from pulling out the optical fiber to adhering the resin so that the temperature of the optical fiber is sufficiently lowered until the resin is adhered. In order to realize this method, there is a method of slowing down the drawing speed of the optical fiber. However, if the drawing speed is slowed down, the manufacturability of the optical fiber is lowered.

As another method in which the temperature of the optical fiber is sufficiently lowered in the time until the resin is attached, there is also a method of lengthening the path through which the optical fiber travels after drawing out until the resin is attached. However, if a method of increasing the height of the building in which the optical fiber manufacturing equipment is installed is adopted in order to lengthen the route, it is necessary to construct a new building or add an extension, which makes it difficult in terms of equipment cost. is there.

On the other hand, a method of controlling the temperature of the optical fiber before adhering the resin by cooling the optical fiber is disclosed. If 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 of annealing the drawn optical fiber with a heat treatment furnace and then forcibly cooling the drawn optical fiber is also disclosed (Patent Document 2).

Further, a method of changing the traveling direction of the optical fiber by a direction converter to lengthen the traveling path of the optical fiber is also disclosed (Patent Documents 3 and 4). According to these techniques, the route can be lengthened in a building of limited height. For example, in Patent Document 3, the optical fiber is once advanced downward and then advanced upward one or more times, or is advanced left and right in the middle of the operation. Then, heating and cooling are performed in the middle of this path.

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

However, the techniques disclosed in Patent Documents 3 and 4 still have room for improvement. For example, when the traveling direction of the optical fiber is changed to the vertical direction as in Patent Document 3, it is necessary to alternately route the tip of the drawn optical fiber to the vertical direction converter, especially at the initial stage of the drawing process. Become. When a worker performs this work, a complicated work is required in which the worker moves up and down the building by using a means of raising and lowering stairs and the like to handle the work. Further, in Patent Document 3, the optical fiber is advanced in the left-right direction in the chamber, but since it is in the chamber, the extension of the path is limited. Further, when the traveling direction of the optical fiber is changed as in Patent Document 4, the positions where the optical fiber travels downward are shifted in the horizontal plane above and below the direction converter. As a result, it is necessary to significantly remodel the existing manufacturing equipment or newly install the manufacturing equipment, such as re-installing or newly installing the part below the direction changer. Therefore, there is a difficulty in terms of equipment cost.

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 a method for manufacturing an optical fiber capable of manufacturing a high-quality optical fiber while suppressing equipment costs and workloads. It is in.

In order to solve the above-mentioned problems and achieve the object, the optical fiber manufacturing apparatus according to one aspect of the present invention is installed on the upper floor of a building on the third floor or higher, and a heating furnace for heating and stretching the optical fiber base material. An optical fiber pick-up device installed below the heating furnace on the lower floor below the upper floor and taking out the optical fiber drawn from the heat-stretched optical fiber base material, and the upper floor and the lower floor. The traveling direction of the optical fiber, which is installed on at least one middle floor located between the optical fibers and is being picked up from the optical fiber base material by the taking device, is set along the floor of the middle floor at a predetermined position on the middle floor. A path extension device that converts the optical fiber into a direction, advances the optical fiber by a predetermined distance, folds back toward the predetermined position side, and then further converts the traveling direction of the optical fiber into a direction toward the take-up device. It is characterized by being prepared.

The optical fiber manufacturing apparatus according to one aspect of the present invention includes at least one temperature control device installed on at least one of the middle floors and controlling the temperature of the optical fiber traveling in a direction along the floor. It is characterized by that.

The optical fiber manufacturing apparatus according to one aspect of the present invention is characterized in that at least one of the temperature control devices heats the optical fiber.

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

The optical fiber manufacturing apparatus according to one aspect of the present invention includes a plurality of the temperature control devices, and in the plurality of temperature control devices, the temperature of the optical fiber is higher on the take-up device side than on the optical fiber base material side. It is characterized by being installed so as to be low.

The optical fiber manufacturing apparatus according to one aspect of the present invention includes a coating forming apparatus for forming a coating on the outer periphery of the optical fiber between the path extending apparatus and the taking-up apparatus in the optical fiber path. It is a feature.

The optical fiber manufacturing apparatus according to one aspect of the present invention forms a protective film that forms a heat-resistant protective layer on the outer periphery of the optical fiber between the heating furnace and the path extension device in the path of the optical fiber. It is characterized by being provided with a device.

The optical fiber manufacturing apparatus according to one aspect of the present invention is configured such that the path extending apparatus converts the traveling direction of the optical fiber into a direction along the floor of the middle floor a plurality of times. It is a feature.

The method for producing an optical fiber according to one aspect of the present invention includes a step of heat-stretching an optical fiber base material on the upper floors of a building on the third floor or higher, and the heat-stretching on the lower floors below the upper floors. The light in the process of being taken from the optical fiber base material in at least one middle floor located between the upper floor and the lower floor, including a step of taking out the optical fiber drawn from the optical fiber base material. The traveling direction of the fiber is changed from a predetermined position on the middle floor to a direction along the floor of the middle floor, the optical fiber is advanced by a predetermined distance, then folded back toward the predetermined position side, and then further described. It is characterized in that the traveling direction of the optical fiber is converted into a taking direction.

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 traveling in a direction along the floor is controlled in at least one of the middle floors.

The method for producing an optical fiber according to one aspect 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 so that the temperature is lower on the side where the optical fiber is taken up than on the side where the optical fiber base material is taken.

The method for manufacturing an optical fiber according to one aspect of the present invention is to form 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 taken and the time when the optical fiber is taken over. It is a feature.

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 the traveling direction of the optical fiber is changed a plurality of times in a direction along the floor of the middle floor.

According to the present invention, it is possible to produce a high-quality optical fiber while suppressing the equipment cost and the work load.

FIG. 1 is a schematic view showing 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 view showing a modification 1 of the path extension device and the temperature control device. FIG. 4 is a schematic view showing a modification 2 of the path extension device and the temperature control device. FIG. 5 is a schematic view showing a modification 3 of the path extension device. FIG. 6 is a schematic view showing a modified example 4 of the path extension device. FIG. 7 is a schematic view showing a modified example 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 to the embodiments described below. Further, in each drawing, the same or corresponding components are appropriately designated by the same reference numerals. In addition, the xyz coordinate axes are appropriately shown in the drawings, and the directions will be described thereby.

FIG. 1 is a schematic view showing 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, referred to as the manufacturing apparatus 100 as appropriate) is installed in the building B. Building B is a building on the third floor or higher having the first floor L1, the second floor L2, the third floor L3, the fourth floor L4, and the fifth floor L5. Each floor has floors F1, F2, F3, F4 and F5 extending substantially parallel to the xy plane. The xy plane is a horizontal plane, and the + z direction is downward in the vertical direction.

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

The heating furnace 10 is installed on the 5th 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 base material P made of known quartz-based glass or the like is set, and the optical fiber base material P is heated and stretched. As a result, the optical fiber OF1 which is a glass optical fiber is pulled out. The glass optical fiber is an optical fiber in a state in which the entire surface 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 taking-up device 52, and a winding device 53.

The coating forming device 51 is installed substantially vertically below the heating furnace 10, and is arranged between the path extending device 40 and the take-up device 52 in the path of the optical fiber OF1. The coating forming device 51 is an apparatus in which a coating is formed on the outer periphery of the optical fiber OF1 drawn from the optical fiber base material P between the path extending device 40 and the taking-up device 52 to form the coated optical fiber OF2. .. The coating forming device 51 is a known device including, for example, a resin coating device for applying an ultraviolet curable resin to the outer periphery of the optical fiber OF1 and an ultraviolet light source for curing the applied ultraviolet curable resin to form a coating. is there.

The take-up device 52 is installed substantially vertically below the heating furnace 10 and the coating forming device 51. In the take-up device 52, a coating is formed on the optical fiber OF1 drawn out from the optical fiber base material P, and the optical fiber OF2 is taken down. The take-up device 52 is a known device including a take-up roller and a drive source for rotationally driving the take-up roller. The optical fiber OF2 taken up by the take-up device 52 is changed in the traveling direction to the winding device 53 installed at another position on the fifth floor L5.

The floors F1, F2, F3, F4, and F5 are each provided with through holes for the optical fiber OF1 to travel downward (+ z direction) from the heating furnace 10 to the take-up device 52.

The take-up device 53 is a device for winding the optical fiber OF2 on the take-up bobbin, and is a known device provided with a drive source for rotationally driving the take-up 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 installed on the fourth floor L4, the third floor L3, and the second floor L2, which are the middle floors located between the upper floor and the lower floor, respectively.

The path extension device 20 includes direction changers 21, 22, and 23. After being drawn out from the optical fiber base material P, the optical fiber OF1 passes through the through hole of the floor F5 and reaches the direction converter 21 of the fourth floor L4. The direction converter 21 converts the traveling direction of the optical fiber OF1 being picked up from the optical fiber base material P by the picking device 52 into a direction along the floor F4 at a predetermined position on the fourth floor L4. In the present embodiment, the direction converter 21 converts the traveling direction of the optical fiber OF1 from the + z direction to the direction along the + x direction. Here, the direction along the floor includes not only the direction parallel to the floor but also the direction inclined to some extent with respect to the floor. Similarly, the direction along a certain direction includes not only a direction parallel to a certain direction but also a direction inclined to some extent with respect to a certain direction.

The direction changer 22 is arranged at a position separated from the direction changer 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 converter 22 converts the traveling direction of the optical fiber OF1 from the + x direction to the −x direction, and folds back toward the predetermined position side.

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 (+ z direction) toward the take-up device 52. The position where the direction converter 23 converts the traveling direction of the optical fiber OF1 is preferably just below the vertical direction of the predetermined position where the direction converter 21 converts the traveling direction of the optical fiber OF1, but the take-up device 52 is optical. As long as the fiber OF1 can be taken over, the fiber OF1 may be displaced in the horizontal direction with respect to the predetermined position. After that, the optical fiber OF1 passes through the through hole formed in the floor F4 and proceeds to the third floor L3.

The path extension device 30 includes direction changers 31, 32, 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 converter 31 converts the traveling direction of the optical fiber OF1 from the + z direction to the 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 converter 32 converts the traveling direction of the optical fiber OF1 from the + x direction to the −x direction, and folds back toward the predetermined position side.

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 (+ z direction) toward the take-up device 52. The position where the direction converter 33 converts the traveling direction of the optical fiber OF1 is preferably just below the vertical direction of the predetermined position where the direction converter 31 converts the traveling direction of the optical fiber OF1, but the take-up device 52 is optical. As long as the fiber OF1 can be taken over, the fiber OF1 may be displaced in the horizontal direction with respect to the predetermined position. After that, the optical fiber OF1 passes through the through hole formed in the floor F3 and proceeds to the second floor L2.

The path extension device 40 includes direction changers 41, 42, and 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 converter 41 converts the traveling direction of the optical fiber OF1 from the + z direction to the 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 converter 42 converts the traveling direction of the optical fiber OF1 from the + x direction to the −x direction, and folds back toward the predetermined position side.

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 (+ z direction) toward the take-up device 52. The position where the direction converter 43 converts the traveling direction of the optical fiber OF1 is preferably just below the vertical direction of the predetermined position where the direction converter 41 converts the traveling direction of the optical fiber OF1, but the take-up device 52 is optical. As long as the fiber OF1 can be taken over, the fiber OF1 may be displaced in the horizontal direction with respect to the predetermined position. After that, the optical fiber OF1 passes through the through hole formed in the floor F2 and proceeds to the lower device 50 of the first floor L1.

The direction converters 21, 22, 23, 31, 32, 33, 41, 42, 43 change the traveling direction of the optical fiber OF1 which is a glass optical fiber so as not to break. The direction converters 21, 22, 23, 31, 32, 33, 41, 42, 43 have 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. Non-contact type such as, can be adopted. Further, a guide roll made of a soft material that is not damaged even if 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 the surface thereof is provided, and 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 adopted.

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

The temperature control device 61 controls the temperature of the optical fiber OF1 to a temperature lower than that of 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 an optical fiber OF1. The temperature control device 62 controls the temperature of the optical fiber OF1 to a temperature lower than that of the temperature control device 61 and higher than room temperature. The temperature control device 62 is, for example, a cooling path having a known configuration capable of naturally cooling the optical fiber OF1. The temperature control device 63 controls the temperature of the optical fiber OF1 to a temperature lower than that of the temperature control device 62 and higher than room temperature. The temperature control device 63 is, for example, a cooling device having a known configuration capable of forcibly cooling the optical fiber OF1. Each of the temperature control devices 61, 62, and 63 may have a temperature gradient in the longitudinal direction. In this way, the temperature control devices 61, 62, and 63 are installed so that the temperature of the optical fiber OF1 is lower on the take-up device 52 side than on the optical fiber base material 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 5th floor L5 heats and stretches the optical fiber base material 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 base material P, and the taking-up device 52 lowers the optical fiber OF2. The take-up device 53 winds up the optical fiber OF2.

At this time, in each of the path extension devices 20, 30, and 40 installed on the 4th floor L4, the 3rd floor L3, and the 2nd floor L2, the traveling direction of the optical fiber OF1 is changed to the direction along the floor surface of each floor. To do. Then, the optical fiber OF1 is advanced by a predetermined distance, then folded back, and then the traveling direction is changed to the direction toward the take-up device 52.

In the manufacturing apparatus 100, the take-up apparatus 52 is installed substantially vertically below the heating furnace 10, and has the same structure as the existing manufacturing apparatus. Therefore, it can be carried out without the need to significantly modify the existing manufacturing equipment or newly install the manufacturing equipment, so that the equipment cost can be suppressed. Then, the traveling direction of the optical fiber being taken from the optical fiber base material P to the taking-up device 52 is changed, and the optical fiber is advanced in the direction along each floor of the 4th floor L4, the 3rd floor L3, and the 2nd floor L2, which are the middle floors. After that, it is turned back and the traveling direction is changed to the direction toward the taking-up device 52 again. As a result, the path of the optical fiber OF1 can be easily lengthened. Further, since the manufacturing apparatus 100 can be configured only by adding a route extension device to each middle floor of the existing manufacturing apparatus, the equipment cost can be suppressed. Taking L4 on the 4th floor as an example, when a worker performs the work of routing the tip of the drawn optical fiber OF1 to the direction converters 21, 22, and 23 at the initial stage of the drawing process, the worker simply goes to the 4th floor. Since the floor F4 may be moved and handled in L4, the work is easy and the work load is significantly reduced. Further, since the path of the optical fiber OF1 from the heating furnace 10 to the coating forming apparatus 51 is lengthened, a good quality coating can be formed in the coating forming apparatus 51. Further, by lengthening the path, the temperature of the optical fiber OF1 can be appropriately controlled, so that an increase in transmission loss can be suppressed. In the present embodiment, since the temperature of the optical fiber OF1 can be controlled more preferably by the temperature control devices 61, 62, 63, it is possible to increase the drawing speed to improve the manufacturability and suppress the increase in transmission loss. it can. The temperature control by the temperature control devices 61, 62, 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, it is possible to manufacture a high-quality optical fiber OF2 while suppressing the equipment cost and the work load, and it is possible to improve the manufacturability.

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

FIG. 2 is a schematic view showing an example of another manufacturing method using the manufacturing apparatus 100. Here, the direction converters 21, 23, 31, 33, 41, and 43 are configured to be retractable from the path from the heating furnace 10 to the take-up device 52. In the case of FIG. 2, the direction converters 31, 33, 41, and 43 are retracted from the positions shown in FIG. 1 in the + x direction.

In the case of FIG. 2, only the route extension device 20 and the temperature control device 61 are used for manufacturing as the route extension device and the temperature control device. As in this example, the routes installed in at least one of the route extension 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, without using any of the path extension device and the temperature control device, the optical fiber OF1 drawn from the optical fiber base material P is directly advanced to the coating forming apparatus 51 to form a coating to manufacture the optical fiber OF2. You may. The drawing speed and the operating conditions of the coating forming apparatus 51 are adjusted so that the optical fiber OF1 is formed with a good quality coating in the coating forming apparatus 51 according to the number of the route extension device and the temperature control device used and the temperature control state. Is preferable.

Further, as an example of another manufacturing method using the manufacturing apparatus 100, at least one of the path extending devices 20, 30, and 40 is used to lengthen the path of the optical fiber OF1, but the temperature control devices 61, 62, It is also possible to stop the operation of 63 and use it. In this case, the optical fiber OF1 is mainly naturally cooled. In this case as well, it is preferable to adjust the drawing speed and the operating conditions of the coating forming apparatus 51 so that the optical fiber OF1 is formed with a good quality coating in the coating forming apparatus 51.

(Modification example)
FIG. 3 is a schematic view showing a modification 1 of a path extension device and a temperature control device applicable to the manufacturing apparatus 100. In this modification 1, the direction converter 22 included in the path extension device 20 installed on the fourth floor L4 of the manufacturing apparatus 100 is replaced with two direction converters 22a and 22b, and the temperature control device 61 is controlled by three temperatures. It is replaced with the devices 61a, 61b, 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 along the floor F4 by a fourth predetermined distance. The direction converter 22a converts the traveling direction of the optical fiber OF1 into a direction along the floor F4 and different from the traveling direction between the direction converter 21 and the direction converter 22a. Specifically, the direction changer 22a changes the traveling direction of the optical fiber OF1 into a direction toward the direction changer 22b arranged at a distant position. The direction changer 22a and the direction changer 22b advance the optical fiber OF1 by a fifth predetermined distance.

The direction changer 22b changes the traveling direction of the optical fiber OF1 into a direction along the floor F4 and toward the direction changer 23. That is, the direction converters 22a and 22b convert the traveling direction of the optical fiber OF1 twice, which is a plurality of times, and fold back the optical fiber OF1 traveling from the direction converter 21 toward the direction converter 23. By changing the traveling direction of the optical fiber OF1 a plurality of times on the same floor in this way, the path of the optical fiber OF1 can be made longer on the single floor.

Further, the temperature control device 61a is arranged 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 arranged between the direction changer 22a and the direction changer 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 to different temperatures, but it is preferable to control the temperature control devices 61a, 61b, and 61c so that the temperatures are lowered in this order. In this way, by controlling the optical fibers OF1 to different temperatures on the same floor, finer temperature control can be performed on the 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, it is equivalent to the temperature control devices 61, 62, 63 of FIG. 1 on a single floor. The temperature can be controlled.

FIG. 4 is a schematic view showing a modification 2 of the path extension device and the temperature control device applicable to the manufacturing apparatus 100. In this modification 2, the direction converter 22 included in the path extension device 20 installed on the fourth floor L4 in the manufacturing apparatus 100 is replaced with three direction converters 22c, 22d, 22e, and the temperature control device 61 is replaced with four. It is replaced with temperature control devices 61d, 61e, 61f, 61g.

In this modification 2, the traveling directions of the optical fiber OF1 are changed three times by the direction converters 22c, 22d, and 22f arranged apart from each other, and the direction of the optical fiber OF1 traveling from the direction converter 21 is changed. Fold back toward the vessel 23. By changing the traveling direction of the optical fiber OF1 a plurality of times on the same floor in this way, the path of the optical fiber OF1 can be made longer on the single floor.

Further, the temperature control device 61d is arranged 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 changer 22c and the direction changer 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, 61g control the optical fiber OF1 to different temperatures, but it is preferable to control the temperature control devices 61d, 61e, 61f, 61g so that the temperatures are lowered in this order. In this way, by controlling the optical fibers OF1 to different temperatures on the same floor, finer temperature control can be performed on the single floor. For example, the temperature control device 61d is used as an annealing furnace, the temperature control device 61e is used as a second annealing furnace, the temperature control device 61f is used as a cooling path, and the temperature control device 61g is used as a cooling device. It is possible to perform finer temperature control than the temperature control devices 61, 62, 63 of 1.

FIG. 5 is a schematic view showing a modification 3 of the path extension device. In this modification 3, the direction converter 22 included in the path extension device 20 installed on the fourth floor L4 of the manufacturing apparatus 100 is replaced with the direction converter 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 converter 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 only a large number of times. The direction converter 22f continuously converts the traveling direction of the optical fiber OF1 traveling from the direction converter 21 and turns back toward the direction converter 23. By using the direction converter 22f having such a configuration, the path of the optical fiber OF1 can be lengthened.

FIG. 6 is a schematic view showing a modified example 4 of the path extension device. In this modification 4, the direction changer 22 included in the path extension device 20 installed on the 4th floor L4 in the manufacturing apparatus 100 is replaced with the direction changer 22g. Although not shown, the temperature control device 61 is arranged between the direction changers 21 and 23 and the direction changer 22g.

The direction changer 22g has a polygonal columnar shape (square columnar shape in the illustrated example) whose central axis is parallel to the z direction, and is configured so that the optical fiber OF1 can be wound only a large number of times. The direction changer 22g changes the traveling direction of the optical fiber OF1 traveling from the direction changing device 21 only a plurality of times and turns back toward the direction changing device 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 other polygonal columnar shapes such as a triangular columnar shape and a hexagonal columnar shape.

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

Further, the configurations of the modifications 1 to 4 shown in FIGS. 3 to 6 may be applied to the path extension device and the temperature control device installed on the third floor L3 or the second floor L2 in the manufacturing apparatus 100.

FIG. 7 is a schematic view showing a modified example 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 arranged between the heating furnace 10 and the first direction converter 21 in the path of the optical fiber OF1. The protective film forming device 70 is a device that forms a heat-resistant protective layer on the outer periphery of 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 the traveling direction of the optical fiber OF1 is changed. Since the optical fiber OF1 has a high temperature after coming out of the heating furnace 10, the protective layer has heat resistance that can withstand the high temperature.

As the protective film forming apparatus 70, for example, an apparatus can be used in which a sol made of TEOS (tetraethyl orthosilicate) is sprayed on the outer periphery of the optical fiber OF1 to form a protective layer made of silica glass gel. A coating may be formed on the outer periphery of the protective layer by the coating forming apparatus 51 as it is. Alternatively, the protective layer may be removed after passing through the last direction converter 43 in the path of the optical fiber OF1 and before forming the coating with the coating forming apparatus 51. As a method of removing the protective layer, a method of spraying a fluid such as gas or liquid on the protective layer to blow off the protective layer to remove the protective layer, or a method of passing the stored liquid through the protective layer to dissolve and remove the protective layer. 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, but the number of middle floors is not limited to this, and may be one or more.

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

10 Heating furnace 11 Heaters 20, 30, 40 Path extension devices 21, 22, 22a, 22b, 22c, 22d, 22e, 22f, 22g, 23, 31, 32, 33, 41, 42, 43 Direction converter 50 Lower device 51 Coating forming device 52 Taking-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 Buildings 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 base material

Claims (10)

A heating furnace installed on the upper floors of the building on the third floor and above to heat and stretch the optical fiber base material,
A take-up device installed below the heating furnace on the lower floor below the upper floor and taking out the optical fiber drawn from the heat-stretched optical fiber base material.
The traveling direction of the optical fiber installed on at least one middle floor located between the upper floor and the lower floor and being taken from the optical fiber base material to the taking device is set at a predetermined position on the middle floor. In the direction along the floor of the middle floor, the optical fiber is advanced by a predetermined distance, then folded back toward the predetermined position side, and then the traveling direction of the optical fiber is further directed toward the take-up device. A route extension device that converts to
A temperature control device, which is installed on at least one of the middle floors and controls the temperature of the optical fiber traveling in a direction along the floor, is provided .
At least one optical fiber manufacturing apparatus, wherein you cool heat or force the optical fiber of the temperature control device. A claim comprising a plurality of the temperature control devices, wherein the plurality of temperature control devices are installed so that the temperature of the optical fiber is lower on the take-up device side than on the optical fiber base material side. Item 2. The optical fiber manufacturing apparatus according to Item 1. The optical fiber according to claim 1 or 2 , wherein a coating forming device for forming a coating on the outer periphery of the optical fiber is provided between the path extending device and the taking-up device in the path of the optical fiber. manufacturing device. Claims 1 to 3 include a protective film forming device 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 path of the optical fiber. The optical fiber manufacturing apparatus according to any one. According to any one of claims 1 to 4 , the path extending device is configured to change the traveling direction of the optical fiber a plurality of times in a direction along the floor of the middle floor. The optical fiber manufacturing apparatus described. The process of heating and stretching the optical fiber base material on the upper floors of the building on the third floor and above,
In the lower floor below the upper floor, a step of taking out the optical fiber drawn from the heat-stretched optical fiber base material, and
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 base material is set from a predetermined position on the middle floor to the middle floor. It is converted into a direction along the floor, the optical fiber is advanced by a predetermined distance, then folded back toward the predetermined position side, and then further converted into a direction in which the traveling direction of the optical fiber is taken over.
A method for producing an optical fiber , which comprises heating and cooling the optical fiber traveling in a direction along the floor in at least one of the middle floors to control the temperature of the optical fiber. The method for manufacturing an optical fiber according to claim 6 , wherein the temperature of the optical fiber is controlled so that the temperature is lower on the side where the optical fiber is taken up than on the side of the optical fiber base material. The optical fiber according to claim 6 or 7 , wherein a coating is formed 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 taken up and the time when the optical fiber is taken over. Production method. The method for manufacturing an optical fiber according to any one of claims 6 to 8 , wherein 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 any one of claims 6 to 9 , 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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