Method for manufacturing an optical fiber and device for manufacturing an optical fiber

Abstract

A method of manufacturing an optical fiber includes: a step of melting an optical fiber preform to draw an optical fiber bare wire; a step of changing a direction of the optical fiber bare wire by a plurality of non-contact guides while cooling the optical fiber bare wire by the plurality of non-contact guides; and a step of coating the optical fiber bare wire with a resin. Each non-contact guide has a guide portion capable of winding a portion of the optical fiber bare wire along an outer peripheral surface. A blowout port that blows out a gas that makes the optical fiber bare wire float is provided in the guide portion. A winding length of the optical fiber bare wire with respect to the plurality of non-contact guides is increased or decreased by adjusting a position of at least one non-contact guide among the plurality of non-contact guides, thereby controlling a cooling capacity of the optical fiber bare wire.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing optical fibers and an apparatus for manufacturing optical fibers.

[0002] This application claims priority based on Japanese Application No. 2022-032800 and Japanese Application No. 2022-032803, filed on March 3, 2022, and invokes all the contents set forth in those Japanese applications. Background Technology

[0003] Patent Document 1 discloses an example of a method for manufacturing optical fibers. In this method, a pre-fiber material is molten and drawn into fibers, and a resin coating is applied to the outer periphery of the drawn bare fiber. Before the resin coating, the drawn bare fiber is cooled while its orientation is changed by a direction changer (non-contact guide). During this cooling, the position of the non-contact guide is moved horizontally based on the outer diameter of the resin coating on the bare fiber, thereby adjusting the length of the bare fiber between the non-contact guides.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-147771 Summary of the Invention

[0007] Methods for solving problems

[0008] This disclosure provides a method for manufacturing an optical fiber. The method includes: a step of melting an optical fiber preform to draw a bare optical fiber; a step of changing the orientation of the bare optical fiber using a plurality of non-contact guides while simultaneously cooling the bare optical fiber using the plurality of non-contact guides; and a step of coating the bare optical fiber with resin. Each non-contact guide has a guide portion along its outer peripheral surface capable of winding a portion of the bare optical fiber, and the guide portion is provided with an outlet for blowing out gas that allows the bare optical fiber to float. By adjusting the position of at least one of the plurality of non-contact guides, the winding length of the bare optical fiber relative to the plurality of non-contact guides is increased or decreased, thereby controlling the cooling capacity of the bare optical fiber. Attached Figure Description

[0009] [ Figure 1 ] Figure 1 This is a schematic diagram of an optical fiber manufacturing apparatus according to one embodiment.

[0010] [ Figure 2 ] Figure 2 It is shown Figure 1 A perspective view of the non-contact guide component of the optical fiber manufacturing apparatus shown.

[0011] [ Figure 3 ] Figure 3 It is shown in Figure 1 The diagram shows the state of the bare optical fiber wound around the non-contact guide in the internal space.

[0012] [ Figure 4 ] Figure 4 It is shown in Figure 1 The diagram shows the state in which bare optical fibers are wound around a non-contact guide within the internal space.

[0013] [ Figure 5 ] Figure 5 It is shown Figure 4 The diagram shows two non-contact guides that are adjacent in direction X among a plurality of non-contact guides.

[0014] [ Figure 6 ] Figure 6 It is a graph showing the relationship between cooling distance and fiber temperature.

[0015] [ Figure 7 ] Figure 7 It is a graph showing the relationship between the traverse distance and the total winding length.

[0016] [ Figure 8 ] Figure 8 It is a graph showing the relationship between lateral distance and total air length.

[0017] [ Figure 9 ] Figure 9 It is a graph showing the relationship between the lateral distance and the total winding length.

[0018] [ Figure 10 ] Figure 10 This is a diagram showing the state in which a bare optical fiber is wound around a non-contact guide within the internal space of the optical fiber manufacturing apparatus according to the first variation.

[0019] [ Figure 11 ] Figure 11 This is a diagram showing the state in which a bare optical fiber is wound around a non-contact guide within the internal space of the optical fiber manufacturing apparatus according to the second variation.

[0020] [ Figure 12 ] Figure 12 This is a schematic diagram of the optical fiber manufacturing apparatus involved in the third variation.

[0021] [ Figure 13 ] Figure 13 This is an enlarged cross-sectional view of the guide area of ​​the non-contact guide component.

[0022] [ Figure 14 ] Figure 14 This is a cross-sectional view of a non-contact guide component. Detailed Implementation

[0023] [The problem this disclosure aims to solve]

[0024] In methods that only adjust the length of the bare fiber optic cable between the aforementioned non-contact guides, the variation in the cooling degree of the bare fiber optic cable is small, sometimes making it difficult to achieve the desired cooling efficiency. Furthermore, the size of the equipment is often spatially limited, sometimes preventing significant lateral movement of the non-contact guides in the horizontal direction. Therefore, a technique is desired that allows for appropriate control of the cooling capacity of the bare fiber optic cable using a compact device.

[0025] [The Effects of This Disclosure]

[0026] According to this disclosure, the cooling capacity of bare optical fiber cables using non-contact guides can be appropriately controlled.

[0027] [Description of embodiments of this disclosure]

[0028] First, embodiments of this disclosure are listed and described. One embodiment of an optical fiber manufacturing method includes: a step of melting an optical fiber preform to draw a bare optical fiber wire; a step of changing the direction of the bare optical fiber wire using a plurality of non-contact guides while simultaneously cooling the bare optical fiber wire using the plurality of non-contact guides; and a step of coating the bare optical fiber wire with resin. Each non-contact guide has a guide portion along its outer peripheral surface capable of winding a portion of the bare optical fiber wire, and a blow-out port is provided in the guide portion for blowing out gas that causes the bare optical fiber wire to float. The cooling capacity of the bare optical fiber wire is controlled by increasing or decreasing the winding length of the bare optical fiber wire relative to the plurality of non-contact guides by adjusting the position of at least one of the plurality of non-contact guides.

[0029] In this optical fiber manufacturing method, the bare optical fiber is redirected via multiple non-contact guides. Adjusting the positions of these guides increases or decreases the winding length of the bare fiber, i.e., increases or decreases the length of the portion of the bare fiber where gas from the non-contact guides can more directly contact the fiber. This increase or decrease in the winding length of the bare fiber has a greater impact on cooling efficiency than the increase or decrease in the length of the bare fiber in the air between the non-contact guides—that is, the length of the portion only passing through the gas atmosphere. Therefore, according to the above manufacturing method, the cooling efficiency of the bare optical fiber can be adjusted over a wider range, thereby allowing for appropriate control of the fiber's cooling capacity.

[0030] In one implementation, at least one of the plurality of non-contact guides can be a movable non-contact guide capable of lateral movement along a horizontal direction. In this method, the winding length can be increased or decreased by adjusting the lateral movement distance of the movable non-contact guide, thereby controlling the cooling capacity of the bare optical fiber. In this case, the movable non-contact guide moves along a horizontal direction. Therefore, compared to the case where the movable non-contact guide moves in an irregular direction, the winding length of the bare optical fiber can be easily calculated, and the cooling capacity of the bare optical fiber can be easily controlled.

[0031] In one implementation, the plurality of non-contact guides can be three or more in an odd number. In this configuration, the non-contact guide located at the even-numbered position from the fiber optic mother material is a movable non-contact guide, which can be moved horizontally to increase or decrease the winding length. In this case, the entry position of the bare fiber relative to the non-contact guide closest to the device for melting the fiber optic mother material (which side of the non-contact guide it contacts) and the exit position of the bare fiber relative to the non-contact guide closest to the device for covering the bare fiber can be aligned on the same side. This facilitates control of the winding length.

[0032] In one implementation, there may be four or more non-contact guides. Among these, the non-contact guides other than the first non-contact guide closest to the fiber optic mother material and the second non-contact guide closest to the coated resin can be movable non-contact guides. Movable non-contact guides located at odd-numbered distances from the fiber optic mother material and movable non-contact guides located at even-numbered distances from the fiber optic mother material can be moved laterally by approximately the same distance in different directions in the horizontal direction, thereby increasing or decreasing the winding length. In this case, the lengths of the bare fiber optic wires among the non-contact guides other than the first and second non-contact guides are approximately the same, and the total winding length of the bare fiber optic wire (the sum of the winding lengths of the bare fiber optic wire relative to each non-contact guide) can be easily calculated. Therefore, the cooling capacity of the bare fiber optic wire can be easily and appropriately controlled.

[0033] As one implementation, the lateral movement distance of the movable non-contact guide can be greater than 0 mm and less than 350 mm. In this case, by keeping the lateral movement distance below 350 mm, the large size of the optical fiber cooling mechanism can be suppressed. Furthermore, when the lateral movement distance is below 350 mm, the change in the total winding length of the bare optical fiber is relatively large relative to the change in the lateral movement distance. Therefore, by adjusting the lateral movement distance slightly, the cooling efficiency of the bare optical fiber can be significantly adjusted, and the cooling capacity of the bare optical fiber can be effectively controlled.

[0034] In one implementation, when the lateral movement of the movable non-contact guide is complete, an imaginary line extending downwards vertically from the non-contact guide closest to the fiber optic mother material among the plurality of non-contact guides coincides with an imaginary line extending downwards vertically from the non-contact guide closest to the coated resin device among the plurality of non-contact guides. In this case, the winding length of the bare fiber relative to the non-contact guide is easily controlled, and the cooling capacity of the bare fiber can be more appropriately controlled.

[0035] As one implementation, the movable non-contact guide can be configured to move laterally, intersecting with an imaginary line extending downwards in the vertical direction from the non-contact guide closest to the fiber optic mother material among a plurality of non-contact guides. In this case, the range of increase or decrease in the winding length toward the non-contact guide can be further increased, and the cooling capacity of the bare fiber can be effectively controlled. In addition, the large-scale development of fiber cooling devices can be suppressed.

[0036] In one implementation, adjacent non-contact guides in the direction of fiber optic cable travel can be spaced apart vertically. The multiple non-contact guides can be arranged at intervals such that the spacing H between them is greater than the outer diameter D2 of each guide. In this case, because the non-contact guides are spaced apart, the angle of inclination of the fiber optic cable's travel direction relative to the horizontal direction, from one guide to the next, can vary depending on the lateral distance of the guide along the horizontal direction. This allows for easy adjustment of the fiber optic cable's winding length relative to the guides. Therefore, the cooling capacity of the fiber optic cable can be appropriately controlled.

[0037] As one implementation, the cooling capacity of the bare optical fiber can be controlled by increasing or decreasing the winding length of the bare optical fiber towards the non-contact guide. This increase or decrease in winding length can be performed during the cooling process of the bare optical fiber. By simultaneously performing the cooling process and controlling the cooling, the cooling of the bare optical fiber can be controlled at a more appropriate time, resulting in higher precision optical fiber. It should be noted that the extent to which the winding length should be increased or decreased can be predetermined before the actual cooling process in manufacturing. In this case, cooling control does not need to be performed every time during manufacturing, thus simplifying the manufacturing method.

[0038] In one embodiment, during the cooling process, gas is ejected from the inside of at least one of the plurality of non-contact guides toward the bare optical fiber. This gas can be dry air with a dew point controlled below 0°C. In this optical fiber manufacturing method, gas (dry air) is ejected onto the bare optical fiber from the inside of a non-contact guide that non-contactly changes the direction of travel of the bare optical fiber. In this case, since dry air is directly blown onto the bare optical fiber in the area close to it, the bare optical fiber can be effectively cooled. Furthermore, the non-contact guide, which changes the direction of the bare optical fiber without contact by ejecting dry air, has a portion (e.g., a groove portion) that receives and guides the bare optical fiber. When the direction of travel of the bare optical fiber changes, the ejected dry air is rapidly released from its narrow guiding portion to a wide area along the entire portion of the non-contact guide. At this time, due to the effect of adiabatic expansion, a local temperature drop occurs, causing condensation of the dry air. This condensation comes into contact with the bare optical fiber, potentially causing a breakage. However, in this manufacturing method, since the dew point of the dry air is controlled below 0°C, condensation can be prevented. Therefore, according to this manufacturing method, the bare optical fiber can be effectively cooled without causing fiber breakage due to condensation. It should be noted that the dry air is not limited to air; any gas can be used. For example, the dry air can be nitrogen.

[0039] In one implementation, during the cooling process, dry air can be supplied to the non-contact guide via a gas filter with a filtration accuracy of 0.03 μm or less. In this case, since impurities are removed from the dry air blown directly onto the bare fiber optic cable by the non-contact guide, breakage of the bare fiber optic cable caused by collisions with impurities contained in the dry air can be prevented. Thus, the bare fiber optic cable can be effectively cooled without causing breakage.

[0040] As one implementation, during the cooling process, the supply of dry air to the non-contact guide can be adjusted using an on / off valve without a metal sliding part. In this case, dust (metal powder, etc.) from the on / off valve adjusting the supply of dry air to the non-contact guide can be reduced, preventing breakage of the bare fiber optic cable due to dust. For example, a pneumatic valve can be used as the on / off valve without a metal sliding part. A solenoid valve can be used in the on / off control of the pneumatic valve.

[0041] One embodiment of the optical fiber manufacturing apparatus includes a melting device, a cooling mechanism, and a coating device. The melting device melts an optical fiber preform to draw bare optical fiber wires from the preform. The cooling mechanism cools the bare optical fiber wires. The coating device coats the bare optical fiber wires with resin. The cooling mechanism has a plurality of non-contact guides that change the travel direction of the bare optical fiber wires. Each non-contact guide has a guide portion along its outer peripheral surface capable of winding a portion of the bare optical fiber wire, and the guide portion has an outlet for blowing out gas that allows the bare optical fiber wire to float. At least one of the plurality of non-contact guides is a movable non-contact guide capable of moving by increasing or decreasing the winding length of the bare optical fiber wire relative to the guide portion.

[0042] In this optical fiber manufacturing apparatus, the winding length of the bare optical fiber can be increased or decreased by adjusting the positions of multiple non-contact guides. As mentioned above, the increase or decrease in the winding length of the bare optical fiber has a greater impact on cooling efficiency than the increase or decrease in the aerial length of the bare optical fiber between the non-contact guides. Therefore, by using the above-described manufacturing apparatus, the cooling efficiency of the bare optical fiber can be adjusted within a wider range, thereby allowing for appropriate control of the cooling capacity of the bare optical fiber.

[0043] As one embodiment of the optical fiber manufacturing apparatus, the apparatus may further include a device for laterally moving a movable non-contact guide. The movable non-contact guide is capable of lateral movement along a horizontal direction. Multiple non-contact guides can be configured to increase or decrease the winding length by adjusting the lateral movement distance of the movable non-contact guides, thereby controlling the cooling capacity of the bare optical fiber. In this case, the non-contact guide moves along a horizontal direction. Therefore, compared to the case where the non-contact guide moves in an irregular direction, the winding length of the bare optical fiber can be easily calculated, and the cooling capacity of the bare optical fiber can be easily controlled.

[0044] As one embodiment of the optical fiber manufacturing apparatus, the movable non-contact guide can be configured to move laterally, intersecting with an imaginary line extending downwards in the vertical direction from among a plurality of non-contact guides closest to the optical fiber mother material. In this case, the range of increase or decrease in the winding length toward the non-contact guide can be further increased, and the cooling capacity of the bare optical fiber can be effectively controlled. In addition, the large-scale development of the optical fiber cooling device can be suppressed.

[0045] In one embodiment of an optical fiber manufacturing apparatus, adjacent non-contact guides in the direction of travel of the bare optical fiber are spaced apart vertically. These non-contact guides can be arranged at intervals such that the spacing H between them is greater than the outer diameter D2 of each guide. In this configuration, because the non-contact guides are spaced apart, the angle of inclination of the direction of travel of the bare optical fiber leading from one guide to the next relative to the horizontal direction can be varied according to the lateral displacement of the guide along the horizontal direction. This allows for easy adjustment of the winding length of the bare optical fiber relative to the guides. Consequently, the cooling capacity of the bare optical fiber can be appropriately controlled.

[0046] As one embodiment of the optical fiber manufacturing apparatus, the cooling mechanism can have 3 to 15 non-contact guides. In this case, by having 3 or more non-contact guides, the total winding length of the bare optical fiber can be adjusted. Furthermore, by having 15 or fewer non-contact guides, the large-scale development of the optical fiber manufacturing apparatus can be suppressed.

[0047] In one embodiment of the optical fiber manufacturing apparatus, the winding diameter of each non-contact guide can be 50 mm or more and 200 mm or less. In this case, by making the winding diameter of each non-contact guide 50 mm or more, the winding length of the bare optical fiber relative to each non-contact guide can be sufficiently ensured, thereby allowing appropriate control of the cooling capacity of the bare optical fiber. Furthermore, by making the winding diameter of each non-contact guide 200 mm or less, the large-scale development of the optical fiber manufacturing apparatus can be suppressed.

[0048] As one embodiment of the optical fiber manufacturing apparatus, the aforementioned optical fiber manufacturing apparatus may further include a supply device for supplying gas to a cooling mechanism. The cooling mechanism may have at least three non-contact guides that eject gas from the inside to the outside in a manner that non-contactly changes the travel direction of the bare optical fiber. The gas supplied from the supply device to the non-contact guides may be dry air with a dew point controlled below 0°C. In this case, since dry air is directly blown onto the bare optical fiber in the area close to it, the bare optical fiber can be effectively cooled. Furthermore, the non-contact guide, which changes the direction of the bare optical fiber without contacting it by ejecting dry air, has a portion (e.g., a groove portion) that receives and guides the bare optical fiber. When the travel direction of the bare optical fiber is changed, the ejected dry air is rapidly released from its narrow guiding portion to a wide area along the entire portion of the non-contact guide. At this time, due to the effect of adiabatic expansion, a local temperature drop occurs, causing condensation of the dry air. This condensation comes into contact with the bare optical fiber, potentially causing a breakage. However, in this manufacturing apparatus, since the dew point of the dry air is controlled below 0°C, this condensation can be prevented. Therefore, according to this manufacturing apparatus, bare optical fiber can be effectively cooled without causing breakage of the bare optical fiber due to condensation.

[0049] As one embodiment of the optical fiber manufacturing apparatus, the aforementioned apparatus may further include a filter disposed between the non-contact guide and the supply device. The filter may be a gas filter with a filtration accuracy of 0.03 μm or less. In this case, since impurities are removed from the dry air directly blown onto the bare optical fiber by the non-contact guide through the filter, breakage of the bare optical fiber caused by collisions with impurities contained in the dry air can be prevented. Thus, the bare optical fiber can be effectively cooled without causing breakage.

[0050] As one embodiment of the optical fiber manufacturing apparatus, the aforementioned apparatus may further include an on / off valve disposed between the non-contact guide and the supply device, which adjusts the supply amount of dry air to the non-contact guide. The on / off valve may be a valve without a metal sliding part. In this case, dust (metal powder, etc.) from the on / off valve adjusting the supply amount of dry air to the non-contact guide can be reduced, preventing breakage of the bare optical fiber due to dust. It should be noted that, for example, a pneumatic valve can be used as an on / off valve without a metal sliding part. A solenoid valve can be used in the opening and closing control of the pneumatic valve.

[0051] [Details of the embodiments disclosed herein]

[0052] Hereinafter, specific examples of the optical fiber manufacturing apparatus and method relating to this disclosure will be described with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same elements or elements having the same function, and repeated descriptions are omitted. It should be noted that the present invention is not limited to these examples, but is indicated by the claims, and is intended to include all modifications of the same meaning and scope as the claims.

[0053] Reference Figure 1 and Figure 2 The optical fiber manufacturing apparatus and optical fiber manufacturing method according to one embodiment will be described. Figure 1 This is a schematic diagram of an optical fiber manufacturing apparatus 1 according to one embodiment. Figure 2 This is a perspective view showing the non-contact guide 20. In this embodiment, the height direction (vertical direction) of the manufacturing apparatus 1 is designated as direction X, the width direction (horizontal direction) as direction Y, and the inward direction as direction Z. In this embodiment, directions X, Y, and Z are orthogonal to each other.

[0054] like Figure 1 As shown, the manufacturing apparatus 1 is an apparatus for manufacturing fiber optic cables 11 by heating and melting the fiber optic mother material 2 to draw the bare fiber optic cable 10, and then applying a coating resin to the outer periphery of the bare fiber optic cable 10. Figure 1 As shown, the manufacturing apparatus 1 includes, in sequence along the path of the bare optical fiber 10 and the fiber optic cable 11: a drawing furnace 3, a cooling section 4, a coating section 5, a curing section 6, a straight roller 7, a traction roller 8, and a winding section 9. Additionally, the manufacturing apparatus 1 includes a transverse transfer device 50.

[0055] The drawing furnace 3 is a melting device for heating and melting the optical fiber mother material 2. The optical fiber mother material 2 can be heated and melted in the drawing furnace 3, and then melted along the vertical direction (…). Figure 1 The fiber is drawn in the direction X shown. The drawing furnace 3 has heaters located around the fiber optic mother material 2. The fiber optic mother material 2 can be, for example, a glass body (preform) containing quartz glass. The drawn fiber optic mother material 2 becomes a bare fiber optic wire 10. The bare fiber optic wire 10 can be, for example, a glass wire containing a core and a cladding covering the outer periphery of the core. The drawn bare fiber optic wire 10 is fed to the cooling section 4.

[0056] The cooling section 4 is a cooling mechanism for cooling the bare optical fiber 10. The cooling section 4 has an internal space S surrounded by an outer wall (including side walls, a top plate, and a bottom plate), through which the bare optical fiber 10 passes. By having an outer wall, the cooling section 4 can prevent broken bare optical fiber 10 from scattering, and can also suppress foreign objects from entering the internal space S, maintaining the cleanliness of the internal space S. The outer wall of the cooling section 4 can also be made of transparent glass or resin, allowing a view of the interior of the cooling section 4.

[0057] The cooling section 4 may also have an intake port (not shown) for injecting dry gas for overall cooling of the bare optical fiber 10 into the internal space S. Heat from the bare optical fiber 10 is released to the outside using the dry gas as a refrigerant. The cooling section 4 may also have an exhaust port (not shown) for discharging the dry gas. The height of the cooling section 4 in the X direction (height of the sidewall) may, for example, be between 1000 mm and 1600 mm. The width of the cooling section 4 in the Y direction (width of the sidewall) may, for example, be between 800 mm and 1400 mm. It should be noted that by surrounding the cooling section 4 with an outer wall, dew point control inside the cooling section 4 can be achieved, preventing the optical fiber from scattering in case of breakage. However, it is also possible to cool the bare optical fiber 10 solely through the non-contact guide 20 described later, without surrounding it with an outer wall. Furthermore, even when surrounded by an outer wall, it is possible to prevent the bare optical fiber 10 from directly contacting the external gas without injecting dry gas into the internal space S.

[0058] The bare fiber optic cable 10 travels through the internal space S in a serpentine manner, with its direction of travel altered by multiple non-contact guides 20. The bare fiber optic cable 10 passes between the non-contact guides 20 along directions inclined relative to both X and Y. The cooling unit 4 has nine non-contact guides 21 to 29. Each non-contact guide 21 to 29 is sequentially arranged along the travel path of the bare fiber optic cable 10. Hereinafter, unless it is necessary to distinguish between the individual non-contact guides 21 to 29, they will be collectively referred to as non-contact guides 20 and described accordingly. The cooling unit 4 may have multiple non-contact guides 20, not limited to nine. For example, the cooling unit 4 may have three or more, or up to fifteen, non-contact guides 20.

[0059] The non-contact guide 20 is a component that changes the travel direction of the bare optical fiber 10 in a non-contact manner. For example... Figure 2 As shown, the non-contact guide 20 includes a first flange 30 and a second flange 35. The first flange 30 and the second flange 35 are disk-shaped components arranged to overlap each other in a direction along the central axis C. The non-contact guide 20 has a guide portion 40 between the first flange 30 and the second flange 35. The guide portion 40 is a gap provided between the outer edges of the first flange 30 and the second flange 35. The guide portion 40 is annular along the outer periphery of the non-contact guide 20. The bare optical fiber 10 passes through the guide portion 40.

[0060] The internal component 41 is housed within the first flange 30 and the second flange 35 (see reference). Figure 13The internal component 41 is connected to an external gas supply source (air pump, etc.). The internal component 41 blows gas supplied from the gas supply source to the outside of the non-contact guide 20 via a blowout port inside the guide section 40. The gas supplied from the gas supply source may, for example, fill the internal space S of the cooling section 4 (see reference). Figure 1 The blown gas is a dry gas. The blown gas is directed onto the bare optical fiber 10 passing through the guide section 40. The bare optical fiber 10 floats due to the blowing gas. Figure 13 (as shown in the diagram), so as not to contact the first flange 30 and the second flange 35.

[0061] The second flange 35 can also be movably mounted on the internal component 41. In this case, by moving the second flange 35 to change the width of the guide portion 40, the pressure of the gas blown from the guide portion 40 can be adjusted. The pressure of the gas blown from the guide portion 40 can also be appropriately adjusted according to the diameter or type of the bare optical fiber 10 passing through the guide portion 40. The first flange 30 can be fixed to the internal component 41, or, like the second flange 35, can be mounted on the internal component 41 in a manner that allows it to move in the direction that changes the width of the guide portion 40.

[0062] At least one of the non-contact guides 20 is a movable non-contact guide capable of moving along the direction Y in a manner traversing the internal space S. During the optical fiber manufacturing process, the position of at least one of the multiple non-contact guides 20 is adjusted to increase or decrease the winding length of the bare optical fiber 10 relative to the non-contact guide 20. This controls the cooling capacity of the bare optical fiber 10. The winding length of the bare optical fiber 10 is the length of the portion of the bare optical fiber 10 passing through the guide portion 40 located on an arc centered on the central axis C of the non-contact guide 20 (hereinafter referred to as the winding portion).

[0063] In this embodiment, the even-numbered non-contact guides 20 (non-contact guides 22, 24, 26, and 28) are positioned along the Y direction. Figure 1 The paper moves to the right. The even-numbered non-contact guide 20 is the one located at the even-numbered distance from the optical fiber mother material 2, and is counted as the even-numbered position when counting the non-contact guides 20 in the order in which the bare optical fiber 10 passes. On the other hand, the odd-numbered non-contact guide 20 is the one located at the odd-numbered distance from the optical fiber mother material, and is counted as the odd-numbered position when counting the non-contact guides 20 in the order in which the bare optical fiber 10 passes. In this embodiment, the odd-numbered non-contact guides 20 are non-contact guides 21, 23, 25, 27, and 29.

[0064] The manufacturing apparatus 1 includes a lateral movement device 50 for laterally moving each non-contact guide 20. Here, lateral movement of the non-contact guide 20 means moving the non-contact guide 20 along the Y direction (horizontal direction). That is, the lateral movement device 50 is configured to move each non-contact guide 20 along the Y direction (horizontal direction). Each non-contact guide 20 is mounted on the lateral movement device 50. Each non-contact guide 20 can be attached to and detached from the lateral movement device 50. That is, the number of non-contact guides 20 in the cooling section 4 can be changed. By changing the number of non-contact guides 20, the total winding length of the bare optical fiber 10 relative to the non-contact guides 20 can be adjusted. The total winding length of the bare optical fiber 10 refers to the sum of the winding lengths of the bare optical fiber 10 relative to each non-contact guide 20 in the cooling section 4.

[0065] The bare optical fiber 10 is deflected by multiple non-contact guides 20 and moves within the internal space S. After being cooled by the cooling unit 4, the bare optical fiber 10 is sent to the coating unit 5.

[0066] The coating section 5 is a coating apparatus that coats the outer periphery of the bare optical fiber 10 with a coating resin. The coating resin is, for example, an ultraviolet-curable resin. The coating section 5 may also coat the outer periphery of the bare optical fiber 10 with two different types of coating resin. For example, the coating section 5 may coat the primary resin onto the bare optical fiber 10, and then coat the secondary resin on the outside of the primary resin. Alternatively, the coating section 5 may coat the primary resin and the secondary resin onto the bare optical fiber 10 approximately simultaneously. The bare optical fiber 10 coated with the coating resin is then fed to the curing section 6.

[0067] The curing section 6 is a curing apparatus that cures the coating resin applied to the bare optical fiber 10 by irradiating it with ultraviolet light. The curing section 6 has a light-emitting element such as an ultraviolet lamp that emits ultraviolet light. By curing the coating resin applied to the bare optical fiber 10, the optical fiber 11 is completed. The optical fiber 11 is then fed to the direct roller 7.

[0068] The direct-descent roller 7 is a roller that changes the travel direction of the fiber optic cable 11 from the direction along direction X to a predetermined direction. The fiber optic cable 11, whose travel direction has been changed by the direct-descent roller 7, is fed to the traction roller 8. The traction roller 8 is a roller that pulls the fiber optic cable 11 and moves it. By changing the rotational speed of the traction roller 8, the movement speed of the bare fiber optic cable 10 and the fiber optic cable 11 can be adjusted. The fiber optic cable 11 is fed from the traction roller 8 to the winding section 9. The winding section 9 is a component that winds the fiber optic cable 11. The winding section 9 may, for example, be a spool capable of winding the fiber optic cable 11. As described above, the manufacturing process of the fiber optic cable 11 is completed.

[0069] Reference Figure 3 and Figure 4The method of winding the bare optical fiber 10 onto the non-contact guide 20 and the method of adjusting the winding length of the bare optical fiber 10 are described. Figure 3 This is a diagram showing the state before the bare optical fiber 10 is wound around the non-contact guide 20. Figure 4 This diagram shows the state in which the bare optical fiber 10 is wound around the non-contact guide 20. Figure 4 In the diagram, the bare optical fiber 10 and the non-contact guide 20 are represented by dashed lines before being wound around the non-contact guide 20, and the bare optical fiber 10 and the non-contact guide 20 are represented by solid lines after being wound.

[0070] Before the bare fiber optic cable 10 is wound around the non-contact guide 20, as follows: Figure 3 As shown, the bare optical fiber 10 is arranged to extend along the X direction. The bare optical fiber 10 is arranged to be held in the Y direction by odd-numbered and even-numbered non-contact guides 20. The plurality of non-contact guides 20 are arranged such that adjacent non-contact guides 20 in the direction of travel of the bare optical fiber 10 are spaced apart from each other by a predetermined distance in the X direction. That is, the odd-numbered and even-numbered non-contact guides 20 are alternately arranged such that their positions in the X direction do not overlap.

[0071] In this state, the non-contact guide 20 is moved laterally. The lateral movement of the non-contact guide 20 is performed using the lateral movement device 50 provided in the manufacturing apparatus 1 (see reference). Figure 1 This is done by moving the odd-numbered non-contact guide 20 and the even-numbered non-contact guide 20 laterally toward the bare optical fiber 10 in different directions.

[0072] like Figure 4 As shown, the odd-numbered non-contact guide 20 is moved laterally until its outer edge approximately overlaps with the bare optical fiber 10 extending along the X direction (until the bare optical fiber 10 passes through the guide portion 40). The even-numbered non-contact guide 20 is moved laterally intersecting with an imaginary line extending downward along the X direction from the uppermost non-contact guide 21 closest to the optical fiber mother material 2. The even-numbered non-contact guide 20 passes between the odd-numbered non-contact guides 20, moving laterally until it is closer to the position where the bare optical fiber 10 was positioned before the lateral movement. Figure 4 The position on the right side of the paper. By laterally moving each non-contact guide 20, thereby affecting the outer periphery of the non-contact guide 20 ( Figure 2 The guide section 40 shown is wound with the bare optical fiber 10.

[0073] By appropriately adjusting the lateral movement distance of the non-contact guide 20, the winding length of the bare optical fiber 10 can be increased or decreased, thereby controlling the cooling capacity of the bare optical fiber 10. The control of the cooling capacity of the bare optical fiber 10 (the increase or decrease in winding length) can be performed during the cooling process of the bare optical fiber 10 in the optical fiber manufacturing process. When increasing or decreasing the winding length, it is not necessary to move all the non-contact guides 20 laterally; for example, only the even-numbered non-contact guides 20 can be moved laterally, or only any one of the non-contact guides 20 can be moved laterally. Regarding the relationship between the lateral movement distance and the winding length, refer to... Figure 7 To be discussed later.

[0074] With the lateral movement of the non-contact guide 20 completed, the bare optical fiber 10 introduced into the uppermost non-contact guide 21 closest to the optical fiber mother material 2 and the bare optical fiber 10 discharged from the lowermost non-contact guide 29 closest to the coating section 5 extend along the direction X. On the other hand, the bare optical fiber 10 between each non-contact guide 20 extends in a direction inclined relative to the direction X. In this embodiment, the lengths of the bare optical fiber 10 between each non-contact guide 20 are approximately the same. With the lateral movement of the non-contact guide 20 completed, the imaginary line extending downward in the vertical direction from the non-contact guide 21 coincides with the imaginary line extending downward in the vertical direction from the non-contact guide 29.

[0075] The travel direction of the bare optical fiber 10 is changed by a predetermined angle α by each non-contact guide 20. The angle α by which the travel direction is changed by the non-contact guide 20 is the angle between the travel direction of the bare optical fiber 10 assuming its travel direction is not changed by the non-contact guide 20 and the travel direction of the bare optical fiber 10 whose travel direction has been changed by the non-contact guide 20. That is, the angle α changed by the non-contact guide 21 is the travel direction of the bare optical fiber 10 assuming its travel direction is not changed by the non-contact guide 21 (along...). Figure 4 The direction of travel of the straight line SL1 (towards the bottom of the paper) and the direction of travel of the bare optical fiber 10 (along the direction of travel of the non-contact guide 21) are different. Figure 4 The angle α1 formed by the direction of travel of the straight line SL2 (as shown) to the right of the paper is, when using the angle θ described later, α1 = π / 2 + θ. Furthermore, the angle α changed by the non-contact guide 22 is the travel direction of the bare fiber optic cable 10 (along the direction of travel) assuming the travel direction is not changed by the non-contact guide 22. Figure 4 The direction of travel of the straight line SL2 (towards the right side of the paper) and the direction of travel of the bare optical fiber 10 whose direction of travel has been changed by the non-contact guide 22 (along the direction of travel of the bare optical fiber 10) Figure 4The angle α2 formed by the method of the straight line SL3 traveling to the left of the paper is 2θ when the angle θ described later is used. Here, the straight line SL3 is the straight line along the bare optical fiber 10 that is discharged from the non-contact guide 22 and introduced into the non-contact guide 23.

[0076] In this embodiment, the travel direction of the bare optical fiber 10 is changed by an angle α slightly more than 90° (e.g., an angle of 95° to 110°) by the non-contact guide 21 and the non-contact guide 29, and the travel direction of the bare optical fiber 10 is changed by an angle α (e.g., an angle of 10° to 40°) by the other non-contact guides 22 to 28.

[0077] Figure 5 This diagram shows two adjacent non-contact guides 20 in the X direction. Figure 5 In this example, non-contact guide 21 and non-contact guide 22 are shown. Figure 5 For ease of explanation, the width between the non-contact guide 21 and the non-contact guide 22 in the Y direction is compared with... Figure 4 Shown in comparison to a smaller size. Figure 5 In the diagram, non-contact guides 21 and 22, representing the end of the lateral movement state, are indicated by solid lines. Additionally, in... Figure 5 In the process, when the non-contact guide 22 begins to move laterally and the bare fiber optic cable 10 extends vertically along the direction X, the non-contact guide 22 located at the point where the bare fiber optic cable 10 passes through the guide portion 40 without bending (hereinafter referred to as the reference point) is designated as non-contact guide 22A and indicated by a double-dotted line.

[0078] Here, for Figure 5 The distances between the locations shown are explained. Figure 5 The spacing width H shown is the distance in direction X between the central axes C of adjacent non-contact guides 20. The spacing width H can be adjusted by changing the position of each non-contact guide 20 in direction X. Additionally, the horizontal distance L is the distance in direction Y between the central axes C of adjacent non-contact guides 20. The horizontal distance L can be, for example, between 50 mm and 450 mm. The horizontal distance L can also be adjusted by changing the position of each non-contact guide 20 in direction Y (by laterally shifting each non-contact guide 20).

[0079] The winding diameter D1 refers to the diameter of the circle formed by the bare optical fiber 10 when it is wound around the entire outer circumference of the guide portion 40 in each non-contact guide 20. The winding diameter D1 can be, for example, 50 mm or more and 200 mm or less. The outer diameter D2 is the diameter of the flange portion of each non-contact guide 20 (the diameter of the outer edge of the non-contact guide 20 when viewed from direction Z). The outer diameter D2 can be, for example, 80 mm or more and 230 mm or less. Multiple non-contact guides 20 are arranged at certain intervals such that the spacing width H between the multiple non-contact guides 20 is greater than the outer diameter D2 of each of the multiple non-contact guides 20. The spacing width H can be, for example, 150 mm or more and 200 mm or less. The lateral movement distance L11 refers to the distance between the non-contact guides 20 located at the reference point (…). Figure 5 The central axis C of the non-contact guide 22A shown is parallel to the transverse non-contact guide 20 (e.g. Figure 5 The distance of the central axis C of the non-contact guide 22) shown in the direction Y. The lateral distance L11 only needs to be greater than 0 mm, for example, it can be more than 100 mm and less than 500 mm, more than 200 mm and less than 400 mm, or about 350 mm.

[0080] The bare fiber optic cable 10, having entered the internal space S, moves along the direction X and then passes through the guide portion 40 of the non-contact guide 21. The bare fiber optic cable 10 then moves in a manner that winds around the non-contact guide 21 along the guide portion 40, exits from the guide portion 40, and is fed to the non-contact guide 22. The bare fiber optic cable 10 between the non-contact guide 21 and the non-contact guide 22 extends in a direction intersecting the direction X at an angle θ. The bare fiber optic cable 10 fed to the non-contact guide 22 passes through the guide portion 40 of the non-contact guide 22. The bare fiber optic cable 10 then moves in a manner that winds around the non-contact guide 22 along the guide portion 40, exits from the guide portion 40, and is fed to the non-contact guide 23 (see reference). Figure 4 At this point, the horizontal distance L is calculated using the following mathematical formula (1).

[0081] L=(H-D1 / cosθ) / tanθ…(1)

[0082] Next, the winding length and air length of the bare optical fiber 10 will be explained. As described above, the winding length of the bare optical fiber 10 is the length of the portion of the bare optical fiber 10 passing through the guide portion 40 located on the arc centered on the central axis C of the non-contact guide portion 20 (hereinafter referred to as the winding portion). The winding length L21 of the bare optical fiber 10 relative to the non-contact guide member 21 is calculated by the following mathematical formula (2).

[0083] L21=D1(π-2θ) / 4…(2)

[0084] Additionally, regarding the bare fiber optic cable 10 relative to the non-contact guide 29 (see reference) Figure 4 The winding length of ) can also be calculated using the same formula as mathematical formula (2).

[0085] The winding length L22 of the bare fiber optic cable 10 relative to the non-contact guide 22 is calculated by the following mathematical formula (3).

[0086] L22=D1(π-2θ) / 2…(3)

[0087] Additionally, regarding the bare fiber optic cable 10 relative to the non-contact guides 23 to 28 (see reference) Figure 4 The winding length of ) can also be calculated using the same formula as mathematical formula (3).

[0088] The aerial length of the bare fiber optic cable 10 refers to the length of the portion of the bare fiber optic cable 10 that connects the wound portions to each other. The aerial length L31 of the bare fiber optic cable 10 between the non-contact guide 21 and the non-contact guide 22 is calculated by the following mathematical formula (4).

[0089] L31=D1tanθ+L / cosθ…(4)

[0090] In addition, the aerial length of the bare fiber optic cable 10 between the other non-contact guides 20 can also be calculated using the same formula as mathematical formula (4).

[0091] Figure 6 This is a graph showing the results of calculations relating cooling distance to fiber temperature. Figure 6 In the diagram, the horizontal axis represents the cooling distance (unit: mm), and the vertical axis represents the fiber temperature (unit: °C). Here, the cooling distance refers to the distance within the internal space S of the cooling section 4 (refer to...). Figure 1 The distance the bare fiber optic cable 10 moves. The cooling distance is calculated using the mathematical formulas described above. Fiber temperature refers to the temperature of the bare fiber optic cable 10. Figure 6 The lines shown represent the fiber temperatures when the bare optical fiber 10 is cooled under different conditions, A1 to A3. In the measurements of conditions A1 and A2, the bare optical fiber 10 is moved linearly along direction X within the internal space S without using the non-contact guide 20. Furthermore, in the measurement of condition A1, the linear velocity of the bare optical fiber 10 is set to Y1 m / min under existing conditions, and in the measurement of condition A2, the linear velocity of the bare optical fiber 10 is set to 1.2 × Y1 m / min.

[0092] On the other hand, in the measurement under condition A3, non-contact guides 20 are used to change the direction of travel of the bare optical fiber 10 and move it simultaneously. Eight non-contact guides 20 are used in the measurement under condition A3, and the horizontal distance L between each non-contact guide 20 (refer to...) Figure 5 The length is set to 500mm, and the line speed of the bare fiber optic cable 10 is set to 1.2 × Y1m / minute. Furthermore, under all conditions A1 to A3, it is assumed that the temperature of the bare fiber optic cable 10 upon entering the internal space S is approximately 600°C.

[0093] like Figure 6 As shown, in the measurement under condition A3, compared to the measurements under conditions A1 and A2, the fiber temperature was reduced to approximately 100°C with a shorter cooling distance. By cooling the bare optical fiber 10 to approximately 100°C, a resin coating can be appropriately applied to the outer periphery of the bare optical fiber 10.

[0094] Furthermore, in the measurements under conditions A1 and A2, the fiber temperature decreased slowly. On the other hand, in the measurement under condition A3, the portion of the fiber temperature decreasing slowly and the portion decreasing rapidly alternated. The portion of the fiber temperature decreasing rapidly corresponds to the portion of the bare optical fiber 10 wound towards the non-contact guide 20. According to the inventors, it is believed that when the bare optical fiber 10 is wound around the non-contact guide 20, the fiber temperature decreases rapidly due to the gas blown from the guide portion 40. That is, compared to the air length between the non-contact guides 20, the cooling efficiency of the bare optical fiber 10 can be adjusted more significantly by increasing or decreasing the winding length towards the non-contact guide 20.

[0095] Figure 7 This is a graph showing the relationship between the lateral displacement L11 and the total winding length L20. Figure 7 In the figure, the horizontal axis represents the lateral movement distance L11 (unit: mm) of the even-numbered non-contact guide 20, and the vertical axis represents the total winding length L20 (unit: mm) of the bare optical fiber 10. Figure 7 The graph shows the change in the total winding length L20 when the lateral displacement distance L11 of the even-numbered non-contact guide 20 changes under conditions B1 to B3. The spacing width H between the non-contact guides 20 is 150 mm under condition B1, 170 mm under condition B2, and 190 mm under condition B3. Another example common to all conditions is when the number of non-contact guides 20 in the cooling section 4 is set to 9, and the winding diameter D1 of each non-contact guide 20 is set to 120 mm.

[0096] like Figure 7As shown, under any of conditions B1 to B3, the total winding length L20 increases as the lateral movement distance L11 of the even-numbered non-contact guide 20 increases. However, the increase in the total winding length L20 relative to the increase in the lateral movement distance L11 gradually decreases as the lateral movement distance L11 increases. It can be seen that when the lateral movement distance L11 exceeds approximately 300 mm, the total winding length L20 remains almost constant even when the lateral movement distance L11 is increased. The same tendency is observed when calculating the total winding length L20 by setting the number of non-contact guides 20 in the cooling section 4 to 5 and 7.

[0097] Figure 8 This is a graph showing the relationship between the lateral movement distance L11 and the total aerial length L30. Figure 8 In the diagram, the horizontal axis represents the lateral movement distance L11 (unit: mm) of the even-numbered non-contact guide 20, and the vertical axis represents the total aerial length L30 (unit: mm). Here, the total aerial length refers to the sum of the aerial lengths between all non-contact guides 20. Figure 8 The graph shows the change in the total air length L30 when the lateral movement distance L11 of the even-numbered non-contact guide 20 changes under conditions C1 to C3. Regarding the number of non-contact guides 20 in the cooling section 4, there are 5 under condition C1, 7 under condition C2, and 9 under condition C3. Furthermore, all conditions share the common feature of setting the spacing width H to 170 mm and the winding diameter D1 of each non-contact guide 20 to 120 mm.

[0098] like Figure 8 As shown, under any of conditions C1 to C3, the total aerial length L30 increases with the increase of the lateral movement distance L11 of the even-numbered non-contact guide 20. Figure 7 In contrast, unlike the total winding length L20 mentioned above, the increase in the total aerial length L30 does not decrease even when the lateral distance L11 exceeds 300mm. The total aerial length L30 also exhibits the same tendency when the spacing width H of the non-contact guide 20 is set to 150mm and 190mm.

[0099] Figure 9 This is a graph showing the relationship between the lateral displacement L11 and the total winding length L20. Figure 9 In the figure, the horizontal axis represents the lateral movement distance L11 (unit: mm) of the even-numbered non-contact guide 20, and the vertical axis represents the total winding length L20 (unit: mm). Figure 9 The graph shows the change in total winding length L20 when the lateral displacement distance L11 of the even-numbered non-contact guide 20 changes under conditions E1 to E3.

[0100] In condition E1, the cooling section 4 has 9 non-contact guide members 20, with a winding diameter D1 of 100 mm and a spacing width H of 150 mm. In condition E2, the cooling section 4 has 9 non-contact guide members 20, with a winding diameter D1 of 120 mm and a spacing width H of 170 mm. In condition E3, the cooling section 4 has 7 non-contact guide members 20, with a winding diameter D1 of 150 mm and a spacing width H of 190 mm. Furthermore, the total height T from the top of the uppermost non-contact guide member 20 to the bottom of the lowermost non-contact guide member 20 in the cooling section 4 (refer to...) Figure 4 The value is 1300mm under condition E1, 1480mm under condition E2, and 1350mm under condition E3.

[0101] like Figure 9 As shown, the total winding length L20 under condition E3, where the number of non-contact guides 20 is 7, is greater than the total winding length L20 under condition E1, where the number of non-contact guides 20 is 9. That is, even when the number of non-contact guides 20 is reduced, the total winding length L20 can be increased by adjusting the winding diameter D1 and the spacing width H. Furthermore, in conditions E1 and E3, even if the total height T (and therefore the height of the cooling unit) is equal or the same, setting it to condition E3 will increase the total winding length L20 compared to condition E1.

[0102] Furthermore, the total winding length L20 under condition E2, where the winding diameter D1 is 120 mm, is greater than the total winding length L20 under condition E3, where the winding diameter D1 is 150 mm. That is, even when the winding diameter D1 is reduced, the total winding length L20 can be increased by adjusting the number of non-contact guides 20 and the spacing width H.

[0103] As described above, the winding length of the bare optical fiber 10 can be increased or decreased by appropriately changing the number of non-contact guides 20, the winding diameter D1, the spacing width H, and the lateral movement distance L11. The increase or decrease in winding length can also be performed during the cooling process of the bare optical fiber 10 in the optical fiber manufacturing process. Alternatively, the total winding length L20 of the bare optical fiber 10 can be maximized by considering factors such as the configuration space of the manufacturing apparatus 1 and the weight of each non-contact guide 20.

[0104] As described above, according to the optical fiber manufacturing method of this embodiment, the winding length of the bare optical fiber 10 can be increased or decreased by adjusting the positions of the plurality of non-contact guides 20. The increase or decrease in the winding length of the bare optical fiber 10 has a greater impact on the cooling efficiency than the increase or decrease in the air length of the bare optical fiber 10 between each non-contact guide 20. Therefore, according to the above manufacturing method, the cooling efficiency of the bare optical fiber 10 can be adjusted within a wider range, thereby allowing for appropriate control of the cooling capacity of the bare optical fiber 10.

[0105] <First Variation>

[0106] Reference Figure 10 A first variation of the optical fiber manufacturing apparatus 1 and manufacturing method will be described. Figure 10 This diagram shows the state in which a bare optical fiber 10 is wound around a non-contact guide 20 within the internal space S of the optical fiber manufacturing apparatus according to the first modification. In the following description, the differences from the above-described embodiment will be mainly explained, while common points will sometimes be omitted. Figure 10 In the diagram, the bare optical fiber 10 and the non-contact guide 20 are represented by dashed lines before being wound around the non-contact guide 20, and the bare optical fiber 10 and the non-contact guide 20 are represented by solid lines after being wound.

[0107] In the above embodiments, such as Figure 4 As shown, in the cooling section 4, the even-numbered non-contact guide 20 moves laterally more than the odd-numbered non-contact guide 20. On the other hand, in this modified example, in the cooling section 4A, a portion of the odd-numbered non-contact guide 20 moves laterally by the same distance as the even-numbered non-contact guide 20, which differs from the above embodiment.

[0108] Before the bare optical fiber 10 is wound around the non-contact guide 20, it is arranged to extend along the X direction, similar to the embodiment described above. The bare optical fiber 10 is arranged to be held in the Y direction by the odd-numbered and even-numbered non-contact guides 20. For the plurality of non-contact guides 20, adjacent non-contact guides 20 in the direction of travel of the bare optical fiber 10 are spaced apart from each other in the X direction. That is, the odd-numbered and even-numbered non-contact guides 20 are alternately arranged such that their positions in the X direction do not overlap.

[0109] In this state, the odd-numbered and even-numbered non-contact guides 20 move laterally toward the bare fiber optic cable 10 in different directions from each other. Specifically, the odd-numbered non-contact guide 20 is moved along... Figure 10 The arrow A shown is moved laterally, causing the even-numbered non-contact guide 20 to move along... Figure 10 The arrow B shown indicates a horizontal movement.

[0110] Among the odd-numbered non-contact guides 20, the uppermost non-contact guide 21 (first non-contact guide) closest to the optical fiber mother material 2 and the lowermost non-contact guide 29 (second non-contact guide) closest to the coating section 5 are moved laterally until their outer edges approximately overlap with the bare optical fiber 10 extending along the X direction (until the bare optical fiber 10 passes through the guide section 40). The odd-numbered non-contact guides 20 (non-contact guides 23, 25, and 27), excluding non-contact guides 21 and 29, are moved laterally by approximately the same distance as the even-numbered non-contact guides 20. By appropriately adjusting the lateral movement distance of each non-contact guide 20, the winding length of the bare optical fiber 10 can be increased or decreased, thus controlling the cooling capacity of the bare optical fiber 10.

[0111] In the optical fiber manufacturing method of this modified example, there are four or more non-contact guides 20. Among the multiple non-contact guides 20, the non-contact guides 21 to 28, except for the non-contact guide 21 closest to the optical fiber mother material 2 and the non-contact guide 29 closest to the coating resin device (coating section 5), are movable non-contact guides. By moving the non-contact guides 23, 25, and 27 located at odd-numbered distances from the optical fiber mother material 2 and the non-contact guides 22, 24, 26, and 28 located at even-numbered distances from the optical fiber mother material 2 by approximately the same distance in different directions in the horizontal direction (direction Y), the winding length is increased or decreased. In this case, the lengths of the bare optical fiber 10 among the non-contact guides 20 other than non-contact guides 21 and 29 are approximately the same, and the total winding length L20 of the bare optical fiber 10 can be easily calculated. Therefore, the cooling capacity of the bare optical fiber 10 can be easily and appropriately controlled.

[0112] <Second Variation>

[0113] Reference Figure 11 A second variation of the optical fiber manufacturing apparatus 1 and manufacturing method will be described. Figure 11 This diagram shows the state in which a bare optical fiber 10 is wound around a non-contact guide 20 within the internal space S of the optical fiber manufacturing apparatus according to the second modification. In the following description, the differences from the above-described embodiment will be mainly explained, while common points will sometimes be omitted. Figure 11 In the diagram, the bare optical fiber 10 and the non-contact guide 20 are represented by dashed lines before being wound around the non-contact guide 20, and the bare optical fiber 10 and the non-contact guide 20 are represented by solid lines after being wound.

[0114] like Figure 4As shown, the cooling section 4 according to the above embodiment has an odd number (9) of non-contact guides 20. On the other hand, as Figure 11 As shown, the cooling section 4B involved in this modified example has an even number (8) of non-contact guides 20, which is different from the above embodiment.

[0115] Before the bare optical fiber 10 is wound around the non-contact guide 20, it is arranged to extend along the X direction, similar to the embodiment described above. The bare optical fiber 10 is arranged to be held in the Y direction by the odd-numbered and even-numbered non-contact guides 20. For the plurality of non-contact guides 20, adjacent non-contact guides 20 in the direction of travel of the bare optical fiber 10 are arranged spaced apart from each other in the X direction. That is, the odd-numbered and even-numbered non-contact guides 20 are alternately arranged such that their positions in the X direction do not overlap.

[0116] In this state, the odd-numbered and even-numbered non-contact guides 20 move laterally toward the bare fiber optic cable 10 in different directions from each other. Specifically, the odd-numbered non-contact guide 20 is moved along... Figure 11 The arrow A shown is moved laterally, causing the even-numbered non-contact guide 20 to move along... Figure 11 The arrow B shown indicates a horizontal movement.

[0117] Among the odd-numbered non-contact guides 20, the uppermost non-contact guide 21 closest to the optical fiber mother material 2 and the lowermost non-contact guide 28 closest to the coating section 5 are moved laterally until their outer edges approximately overlap with the bare optical fiber 10 extending along the X direction (until the bare optical fiber 10 passes through the guide section 40). The odd-numbered non-contact guides 20 (excluding non-contact guide 21) are moved laterally by approximately the same distance as the even-numbered non-contact guides 20 (excluding non-contact guide 28) (excluding non-contact guide 22, 24, and 26). By appropriately adjusting the lateral movement distance of each non-contact guide 20, the winding length of the bare optical fiber 10 can be increased or decreased, and the cooling capacity of the bare optical fiber 10 can be controlled.

[0118] In the optical fiber manufacturing method of this modified example, there are four or more non-contact guides 20. Among the multiple non-contact guides 20, the non-contact guides 21 to 27, excluding the non-contact guide 21 closest to the optical fiber mother material 2 and the non-contact guide 28 closest to the coating resin device (coating section 5), are movable non-contact guides. The non-contact guides 20 located at odd-numbered distances from the optical fiber mother material 2 (non-contact guides 23, 25, and 27) and the non-contact guides 20 located at even-numbered distances from the optical fiber mother material 2 (non-contact guides 22, 24, and 26) are moved laterally by approximately the same distance in different directions in the horizontal direction (direction Y), thereby increasing or decreasing the winding length. In this case, the lengths of the bare optical fiber 10 among the non-contact guides 20, excluding non-contact guides 21 and 28, are approximately the same, and the total winding length L20 of the bare optical fiber 10 can be easily calculated. Therefore, the cooling capacity of the bare optical fiber 10 can be easily and appropriately controlled.

[0119] <3rd Variation>

[0120] Reference Figure 12 A third variation of the optical fiber manufacturing apparatus 1 and manufacturing method will be described. Figure 12 This is a schematic diagram of the optical fiber manufacturing apparatus involved in the third variation. (See diagram below.) Figure 12 As shown, the manufacturing apparatus 1A involved in the third modification is an apparatus for manufacturing optical fiber strand 11 by heating and melting the optical fiber mother material 2 to draw the bare optical fiber 10 and applying a coating resin to the outer periphery of the bare optical fiber 10. Similar to manufacturing apparatus 1, manufacturing apparatus 1A includes, in sequence along the path of the bare optical fiber 10 and the optical fiber strand 11, a drawing furnace 3, a cooling section 4, a coating section 5, a curing section 6, a straight roller 7, a traction roller 8, and a winding section 9. Manufacturing apparatus 1A further includes a gas supply device 60, a control device 61, a filter 62, and an on / off valve 63. It should be noted that in... Figure 12 The example shown is of a cooling section 4 with seven non-contact guides 20, but the number of non-contact guides 20 is not limited to this. Additionally, in Figure 12 Although the description of the transverse movement device 50 is omitted in the present invention, the non-contact guide members 20 involved in the third modification are also configured to transverse along the Y direction as in the above embodiment.

[0121] Each non-contact guide 20 also functions as a component for cooling the bare optical fiber 10. That is, as... Figure 12 and Figure 13As shown, gas (dry air) supplied from the gas supply device 60 to the interior of the non-contact guide 20 is blown radially outward from the gap 80 of the guide portion 40, which serves as the non-contact guide 20. The blown dry air is directed from the inside to the bare optical fiber 10 passing through the gap 80. By directly blowing dry air, the bare optical fiber 10 is cooled in a floating state. The bare optical fiber 10, cooled by such a cooling section 4, is then sent to the coating section 5. It should be noted that the dry air is not limited to air, but can be any gas. For example, the dry air can also be nitrogen.

[0122] Next, the gas supply device 60 and control device 61 that supply cooling gas (dry air) to the cooling section 4 (non-contact guide 20) will be described. Based on the control of the control device 61, the gas supply device 60 supplies dry air with a dew point controlled to below 0°C to the cooling section 4. More specifically, the gas supply device 60 supplies dry air to each non-contact guide 20 via a filter 62 and an on / off valve 63. It should be noted that other cooling gases can also be supplied to the housing 4a of the cooling section 4 from other gas supply devices.

[0123] The filter 62 used for supplying dry air is, for example, a gas filter for removing impurities from the dry air. For instance, a gas filter with a filtration accuracy (also called "filtration degree") of 0.03 μm or less can be used. Alternatively, a gas filter with a filtration accuracy of 0.01 μm or less can be used as filter 62. Since there are many foreign particles at the 0.01 μm level in dry air, by setting the filtration accuracy of filter 62 to 0.03 μm or less, the breakage frequency of the bare fiber optic cable 10 caused by collisions with impurities can be reduced by about half. By setting the filtration accuracy of the filter 62 used to 0.01 μm or less, its breakage frequency can be further reduced. Here, "filtration accuracy" refers to a collection efficiency of 99.99% or more for particles of a corresponding size (e.g., particles larger than 0.01 μm when the filtration accuracy is 0.01 μm). Furthermore, the on / off valve 63 used for regulating the flow rate of dry air is, for example, a valve (regulating valve) without a metal sliding part, which can suppress the generation of dust (metal powder) accompanying the sliding. For example, a pneumatic valve can be used as such an on / off valve 63. In the opening and closing control of pneumatic valves, solenoid valves can be used. If the dust collection capacity of the downstream filter 62 is sufficient, the opening and closing valve 63 can also be a solenoid valve.

[0124] The gas supply device 60 includes a gas supply source 60a, a dryer 60b, and a dew point meter 60c. Gas is supplied from the gas supply source 60a at a predetermined pressure. This gas is, for example, air, but could also be nitrogen. The dryer 60b generates dry air by drying the gas supplied from the gas supply source 60a. Through drying by the dryer 60b, the water vapor content in the dry air supplied from the gas supply source 60a is reduced, thereby lowering the dew point of the dry air. More specifically, drying by the dryer 60b reduces the dew point of the dry air to below 0°C. The reduction of water vapor can be achieved, for example, through evaporation or adsorption of water vapor. It should be noted that "dew point" refers to the temperature at which condensation from water vapor to water begins when cooling a gas containing water vapor. When the dew point is below 0°C, condensation from water vapor to water and freezing from water to ice begin when the gas containing water vapor is cooled to the dew point. It should be noted that the dry air used here can be dried using a dryer 60b to achieve a dew point below -10°C, or it can be dried using a dryer 60b to achieve a dew point below -20°C.

[0125] The dew point meter 60c of the gas supply device 60 measures the dew point of the dried air after it has been dried by the dryer 60b. The dried air is dried by the dryer 60b until the dew point measured by the dew point meter 60c reaches a preset dew point, i.e., below 0°C. That is, the gas supply device 60 is controlled by the control device 61 to ensure that the dew point of the dried air supplied to the non-contact guide 20, etc., of the cooling section 4 is below 0°C. As described above, the dew point-controlled dried air is supplied to the cooling section 4 (non-contact guide 20, etc.) via the filter 62, and the internal space S of the cooling section 4 is filled with the dew point-controlled dried air.

[0126] The control device 61 is a device that controls the gas supply device 60 as described above. The control device 61 is, for example, a computer, and is configured with a CPU, a storage medium such as a memory, and an input / output interface. The control device 61 controls the flow rate of the gas supplied from the gas supply source 60a and the gas drying performed by the dryer 60b, so that the dried air supplied from the gas supply device 60 reaches a predetermined dew point, i.e., below 0°C, as measured by the dew point meter 60c.

[0127] Next, refer to Figure 2 and Figure 13 The structure of the non-contact guide 20, which is an example of a non-contact roller, will be described. Figure 2 This is a perspective view showing the non-contact guide 20. Figure 13 yes Figure 2 Enlarged view of the gap around 80.

[0128] The non-contact guide 20 is a component that changes the movement direction of the bare optical fiber 10 without contact. The non-contact guide 20 has a circular shape when viewed from above. Figure 2 and Figure 13 As shown, the non-contact guide 20 has a gap 80 between the first flange 30 and the second flange 35. The gap 80 is annular along the outer periphery of the non-contact guide 20. The bare optical fiber 10 passes through the gap 80. Dry air introduced into the interior of the non-contact guide 20 is blown out radially outward from the gap 80. The blown dry air is directed towards the bare optical fiber 10 passing through the gap 80. The bare optical fiber 10 floats due to the blowing of the dry air, thus avoiding contact with the first flange 30 and the second flange 35. In addition, as described above, the bare optical fiber 10 is cooled by the blowing of the dry air. It should be noted that in the non-contact guide 20, the second flange 35 is configured to be movable relative to the first flange 30, thereby allowing adjustment of the width of the gap 80 between them.

[0129] Next, refer to Figure 13 and Figure 14 The structure of the non-contact guide 20 when the bare optical fiber 10 passes through the gap 80 will be explained. Figure 14 This is a cross-sectional view of the non-contact guide 20. (See diagram below.) Figure 13 As shown, the first flange 30 and the second flange 35 are mounted on the internal component 41 with a gap 80 between the outer edge of the first flange 30 and the outer edge of the second flange 35. In this embodiment, the gap 80 is provided between the outer peripheral surface 32a of the peripheral wall portion 32 of the first flange 30 and the outer peripheral surface 37a of the peripheral wall portion 37 of the second flange 35.

[0130] like Figure 14 As shown, the gap 80 is arranged to surround the central axis C circumferentially along the non-contact guide 20. The bare fiber optic cable 10 passes through the gap 80. Specifically, the bare fiber optic cable 10 enters the gap 80 from the inlet 81, moves along the gap 80, and then exits from the outlet 82 to the outside. Figure 14 In the example shown, the bare fiber optic cable 10 moves in approximately half of the region of the gap 80. That is, the direction of movement of the bare fiber optic cable 10 is changed by approximately 180° by the non-contact guide 20. The positions of the aforementioned inlet portion 81 and outlet portion 82 are determined by the amount of change in the direction of movement of the bare fiber optic cable 10. In this embodiment, as described above, the direction of movement of the bare fiber optic cable 10 is changed by approximately 180°. Therefore, the outlet portion 82 is positioned at a location approximately half the circumferential length of the gap 80 offset from the inlet portion 81. For example, if the direction of movement of the bare fiber optic cable 10 is changed by approximately 90°, the outlet portion 82 can be positioned at a location approximately one-quarter the circumferential length of the gap 80 offset from the inlet portion 81. Figure 14(the uppermost part of the gap 80 in the middle).

[0131] like Figure 13 and Figure 14 As shown, the gap 80 is spatially connected to the buffer groove 45 and the nozzle 47. Thus, dry air ejected from the nozzle 47 passes through the buffer groove 45 and is blown from the gap 80 to the outside of the non-contact guide 20. The dry air blown from the gap 80 is directed towards the bare optical fiber 10 passing through the gap 80. The air pressure of the dry air maintains the bare optical fiber 10 in a state of levitation from the outer peripheral surface 32a of the first flange 30 and the outer peripheral surface 37a of the second flange 35. That is, the bare optical fiber 10 is in a floating state within the gap 80.

[0132] The pressure of the dry air blown out from the gap 80 (blowout pressure) varies depending on factors such as the pressure of the dry air supplied to the gas flow path (not shown) within the non-contact guide 20 (inlet pressure), the width W of the gap 80, and is also affected by factors such as the winding diameter D1 of the non-contact guide 20. Here, the winding diameter D1 refers to the circle formed by the bare optical fiber 10 as it passes through the entire outer circumference of the gap 80. Figure 14 The diameter of circle B, shown by solid and dashed lines. The blow-out pressure is optimized by adjusting the above factors, such as the tension of the bare fiber optic cable 10 or the diameter of the bare fiber optic cable 10.

[0133] Typically, during the process of increasing the linear velocity (moving speed) of the bare optical fiber 10, the tension applied to the bare optical fiber 10 is small. When the pressure of the blown dry air is high, the bare optical fiber 10 resonates and comes into contact with the non-contact guide 20. Therefore, the blowing pressure is reduced during the process of increasing the linear velocity of the bare optical fiber 10. On the other hand, since the tension of the bare optical fiber 10 is maintained at a high level when the linear velocity is stable, the blowing pressure is increased. As a method to increase the blowing pressure, for example, increasing the inlet pressure and reducing the width W of the gap 80 can be used.

[0134] For example, when floating a bare optical fiber 10 with a diameter of 125 μm, the inlet pressure can be set to 50 kPa or more and 200 kPa or less, and the width W of the gap 80 can be set to approximately 0.2 mm. In this case, the airflow rate blown out from the gap 80 of the non-contact guide 20 can be 30 L / min or more and 150 L / min or less.

[0135] When adjusting the blow-out pressure to an appropriate level, first reduce the width W of the gap 80 while a certain flow rate of dry air is passing through, until the inlet pressure reaches a predetermined value (e.g., 200 kPa). At this point, for example, the width W of the gap 80 can be reduced by bringing the second flange 35 closer to the first flange 30. Then, gradually increase the width W of the gap 80 until the blow-out pressure reaches an optimal level (the level at which the bare fiber optic cable 10 floats appropriately). At this point, for example, the width W of the gap 80 can be increased by separating the second flange 35 from the first flange 30. This blow-out pressure adjustment operation can also be performed on... Figure 13 The adjustment is performed on each of the non-contact guides 20 shown. Alternatively, the adjustment operation can be performed at any time during the manufacturing process of the fiber optic cable 11.

[0136] like Figure 14 As shown, the non-contact guide 20 has a sealing member 68. For ease of explanation, in addition to... Figure 14 The sealing member 68 is omitted from the figures other than those shown. The sealing member 68 seals at least one of the plurality of nozzles 47 to impede the passage of dry air from the nozzle 47. The sealing member 68 may be made of, for example, an elastic material such as resin. The sealing member 68 has an elongated shape and is embedded in a portion of the buffer groove 45 in a manner that blocks the nozzle 47. In this embodiment, the sealing member 68 is embedded in approximately half of the buffer groove 45. Dry air does not flow into the portion of the airflow path 46 of the nozzle 47 sealed by the sealing member 68; instead, dry air flows into the other airflow paths 46 of the nozzle 47 that are not sealed.

[0137] In the direction from the central axis C to the outer periphery of the non-contact guide 20 (radial direction of the non-contact guide 20), most of the sealing member 68 is arranged in a manner that does not overlap with the bare optical fiber 10 passing through the gap 80. Figure 14 In the example shown, the portion of the sealing member 68, except for its two ends, is arranged such that it does not overlap with the bare optical fiber 10 passing through the gap 80 in a circumferential position. Furthermore, a pair of air escape sections 84 are provided between the two ends of the sealing member 68 and the bare optical fiber 10, allowing dry air to flow out from the buffer groove 45. By allowing the dry air accumulated in the buffer groove 45 to flow smoothly out through the air escape sections 84, excessive high-pressure dry air is prevented from being blown out of the gap 80, enabling the bare optical fiber 10 to float stably. The shape of the sealing member 68 is not limited to the shape described above. In this embodiment, multiple nozzles 47 are sealed by a single, continuous sealing member 68; however, multiple nozzles 47 may also be sealed separately by multiple, independent sealing members 68.

[0138] Here, refer to Figure 12The method for manufacturing optical fibers using the aforementioned optical fiber manufacturing apparatus 1A will be described. First, fiber drawing begins by melting the optical fiber mother material 2 using a drawing furnace 3 and winding the molten optical fiber strand 11 using a winding unit 9. At this time, the predetermined bare optical fiber strand 10 being drawn is arranged such that its travel direction is changed by each non-contact guide member 20.

[0139] Next, the travel direction of the bare optical fiber 10 drawn from the optical fiber mother material 2 is changed by each non-contact guide 20, while the bare optical fiber 10 is cooled by dry air sprayed from the inside of each non-contact guide 20 onto the bare optical fiber 10. As described above, this dry air is dry air with a dew point controlled below 0°C by a gas supply device 60 and a control device 61. In addition, this dew point-adjusted dry air is supplied from the gas supply device 60 to each non-contact guide 20 via an on / off valve 63 and a filter 62.

[0140] Next, the fully cooled bare optical fiber 10 exits from the cooling section 4 and is coated with a predetermined resin in the coating section 5. Then, the coated resin is cured in the curing section 6 and wound up as an optical fiber 11 by the winding section 9.

[0141] In addition to the aforementioned effects, the optical fiber manufacturing method and apparatus according to this modified example also spray dry air onto the optical fiber bare wire 10 from the inside of the non-contact guide 20, which changes the traveling direction of the optical fiber bare wire 10 without contact. In this case, since dry air is directly blown onto the optical fiber bare wire 10 in the area close to it, the optical fiber bare wire 10 can be effectively cooled. Furthermore, the non-contact guide 20, which changes the direction of the optical fiber bare wire without contact by spraying dry air, has a portion (e.g., gap 80) that receives and guides the optical fiber bare wire 10. When the traveling direction of the optical fiber bare wire 10 is changed, the sprayed dry air is rapidly released from the narrow gap 80 into a wide area along the entire portion of the non-contact guide 20. At this time, due to the effect of adiabatic expansion, a local temperature drop occurs, causing condensation of the dry air. This condensation comes into contact with the optical fiber bare wire 10, which may result in wire breakage. However, in the manufacturing method described in the above embodiments, since the dew point of the dry air is controlled to be below 0°C, condensation can be prevented. Therefore, according to this manufacturing method, fiber optic cable breakage caused by condensation will not occur, and the fiber optic cable can be effectively cooled by the non-contact guide 20 and the like.

[0142] The embodiments and various modifications involved in this disclosure have been described in detail above. However, the present invention is not limited to the above embodiments and can be applied to various embodiments and modifications.

[0143] For example, in the embodiments described above, the lateral movement distance of each non-contact guide 20 may be different. Furthermore, the winding diameter D1 and outer diameter D2 of each non-contact guide 20 may also be different. Each non-contact guide 20 may move along directions X and Z or directions intersecting these directions, and is not limited to direction Y.

[0144] Furthermore, regarding the manufacturing apparatus and method involved in the third modification, the case where the cooling section 4 is described in which the non-contact guide 20 moves laterally in the Y direction to increase or decrease the winding length of the bare optical fiber 10 has been explained. However, this can also be applied to the case where the non-contact guide 20 does not move laterally. That is, for an optical fiber manufacturing apparatus equipped with a cooling section 4 in which the non-contact guide 20 does not move laterally, a gas supply device 60, a control device 61, a filter 62, and an on / off valve 63 can also be provided. In this case, the same effect can be achieved. As such, the following is noted.

[0145] [Postscript 1]

[0146] A method for manufacturing optical fiber, comprising:

[0147] The process of drawing bare optical fiber wires by melting the optical fiber matrix;

[0148] A cooling process that simultaneously cools the bare optical fiber by changing its travel direction using at least one non-contact guide; and

[0149] The process of coating the bare optical fiber with resin to form an optical fiber wire.

[0150] In the cooling process, gas is ejected from the inside of the non-contact guide toward the bare optical fiber. The gas is dry air with a dew point controlled below 0°C.

[0151] [Postscript 2]

[0152] The method for manufacturing optical fibers described in Appendix 1, wherein,

[0153] In the cooling process, dry air is supplied to the non-contact guide via a gas filter with a filtration accuracy of less than 0.03 μm.

[0154] [Postscript 3]

[0155] The method for manufacturing optical fibers described in Appendix 1 or Appendix 2, wherein,

[0156] In the cooling process, the supply of dry air to the non-contact guide is adjusted by opening and closing a valve that does not have a metal sliding part.

[0157] [Postscript 4]

[0158] An optical fiber manufacturing apparatus comprising:

[0159] A melting apparatus for drawing bare optical fibers from optical fiber mother material, and a cooling apparatus for cooling the bare optical fibers.

[0160] A gas supply device for supplying gas to the cooling device, and

[0161] A coating device for forming optical fiber strands by coating the bare optical fiber with resin.

[0162] The cooling device has at least three non-contact guides that spray the gas from the inside to the outside in a manner that non-contactly changes the direction of travel of the bare optical fiber.

[0163] The gas supplied from the supply device to the non-contact guide is dry air with a dew point controlled below 0°C.

[0164] [Postscript 5]

[0165] The optical fiber manufacturing apparatus described in Appendix 4

[0166] It further includes a filter disposed between the non-contact guide and the supply device.

[0167] The filter is a gas filter with a filtration accuracy of less than 0.03 μm.

[0168] [Postscript 6]

[0169] The optical fiber manufacturing apparatus described in Appendix 4 or Appendix 5.

[0170] Furthermore, it includes an on / off valve disposed between the non-contact guide and the supply device, which adjusts the supply amount of the dry air to the non-contact guide.

[0171] The aforementioned on / off valve is an on / off valve without a metal sliding part.

[0172] Explanation of symbols

[0173] 1, 1A… Manufacturing apparatus

[0174] 2…Fiber optic mother material

[0175] 3… Wire drawing furnace

[0176] 4, 4A, 4B... Cooling section

[0177] 4a…shell

[0178] 5…Coating Section

[0179] 6…Cure Department

[0180] 7…Straight Down Roller

[0181] 8…traction rollers

[0182] 9… Rolling Section

[0183] 10…Bare fiber optic cable

[0184] 11…Fiber optic cable

[0185] 20, 21, 22, 22A, 23, 24, 25, 26, 27, 28, 29… Non-contact guide components

[0186] 30…First flange

[0187] 32… Zhoubi section

[0188] 32a…outer peripheral surface

[0189] 35…Second flange

[0190] 37… Zhoubi section

[0191] 37a…outer peripheral surface

[0192] 40…Guide Section

[0193] 45… Buffer slot

[0194] 46…Airflow path

[0195] 47…spray outlet

[0196] 50…Transverse movement device

[0197] 60…Gas supply device

[0198] 60a…Gas supply source

[0199] 60b…dryer

[0200] 60c… Dew Point Meter

[0201] 61…Control device

[0202] 62… filter

[0203] 63… On / off valve

[0204] 68…Sealing components

[0205] 80…gap

[0206] 81…Inlet section

[0207] 82…out of bounds

[0208] 84…Air Escape Section

[0209] B… circle

[0210] C…Central axis

[0211] D1…wound diameter

[0212] D2…Outer Diameter

[0213] H… Spacing width

[0214] L…horizontal distance

[0215] L11… Lateral movement distance

[0216] L20…Total winding length

[0217] L21, L22… winding length

[0218] L30…total aerial length

[0219] L31…Aerial Length

[0220] S…interior space

[0221] θ… angle

Claims

1. A method for manufacturing an optical fiber, comprising: The process of drawing bare optical fiber wires by melting the optical fiber matrix; The process of changing the direction of the bare optical fiber through multiple non-contact guides and simultaneously cooling the bare optical fiber through the multiple non-contact guides. as well as The process of coating the bare optical fiber with resin. Each of the plurality of non-contact guides has a guide portion along its outer peripheral surface capable of winding a portion of the bare optical fiber, and the guide portion is provided with an outlet for blowing out gas to make the bare optical fiber float. The cooling capacity of the bare optical fiber is controlled by increasing or decreasing the winding length of the bare optical fiber relative to the plurality of non-contact guides by adjusting the position of at least one of the plurality of non-contact guides. The winding length is the length of the portion of the bare optical fiber from which gas from the plurality of non-contact guides directly contacts the bare optical fiber. Among the plurality of non-contact guides, adjacent non-contact guides in the direction of travel of the bare optical fiber are spaced apart from each other in the vertical direction. The plurality of non-contact guides are arranged at certain intervals, such that the spacing width H between the plurality of non-contact guides is greater than the outer diameter D2 of each of the plurality of non-contact guides.

2. The method for manufacturing optical fiber according to claim 1, wherein, At least one of the plurality of non-contact guides is a movable non-contact guide capable of lateral movement along the horizontal direction. The cooling capacity of the bare optical fiber is controlled by adjusting the lateral movement distance of the movable non-contact guide to increase or decrease the winding length.

3. The method for manufacturing optical fiber according to claim 2, wherein, The plurality of non-contact guides is an odd number of three or more non-contact guides. Among the plurality of non-contact guides, the non-contact guide located at the even-numbered position from the optical fiber mother material is the movable non-contact guide, which moves laterally along the horizontal direction to increase or decrease the winding length.

4. The method for manufacturing optical fiber according to claim 2, wherein, The plurality of non-contact guides are four or more non-contact guides. Of the plurality of non-contact guides, the non-contact guides other than the first non-contact guide closest to the optical fiber matrix and the second non-contact guide closest to the device coated with the resin are the movable non-contact guides. The moving non-contact guide located at an odd-numbered position from the optical fiber mother material and the moving non-contact guide located at an even-numbered position from the optical fiber mother material are moved laterally by the same distance in different directions in the horizontal direction, thereby increasing or decreasing the winding length.

5. The method for manufacturing an optical fiber according to any one of claims 2 to 4, wherein, The lateral movement distance of the movable non-contact guide is greater than 0 mm and less than 350 mm.

6. The method for manufacturing an optical fiber according to any one of claims 1 to 4, wherein, The cooling capacity of the bare optical fiber is controlled by increasing or decreasing the winding length, which is performed during the cooling process of the bare optical fiber.

7. The method for manufacturing an optical fiber according to any one of claims 1 to 4, wherein, In the process of cooling the bare optical fiber, gas is ejected from the inside of at least one of the plurality of non-contact guides toward the bare optical fiber. The gas is dry air with a dew point controlled below 0°C.

8. The method for manufacturing optical fiber according to claim 7, wherein, In the process of cooling the bare optical fiber, dry air is supplied to the non-contact guide via a gas filter with a filtration accuracy of less than 0.03 μm.

9. The method for manufacturing optical fiber according to claim 7, wherein, In the process of cooling the bare optical fiber, the supply of dry air to the non-contact guide is adjusted by using an opening and closing valve without a metal sliding part.

10. The method for manufacturing optical fiber according to claim 8, wherein, In the process of cooling the bare optical fiber, the supply of dry air to the non-contact guide is adjusted by using an opening and closing valve without a metal sliding part.

11. An apparatus for manufacturing optical fibers, comprising: A melting apparatus for melting the optical fiber mother material to draw bare optical fiber from the optical fiber mother material; Cooling mechanism for cooling the bare optical fiber wire, and A coating device that uses resin to coat the bare optical fiber wire. The cooling mechanism has multiple non-contact guides that change the travel direction of the bare optical fiber. Each of the plurality of non-contact guides has a guide portion along its outer peripheral surface capable of winding a portion of the bare optical fiber, and the guide portion is provided with an outlet for blowing out gas to make the bare optical fiber float. At least one of the plurality of non-contact guides is a movable non-contact guide capable of moving by increasing or decreasing the winding length of the bare optical fiber relative to the guide portion, wherein the winding length is the length of the portion from which gas from the plurality of non-contact guides directly contacts the bare optical fiber. Among the plurality of non-contact guides, adjacent non-contact guides in the direction of travel of the bare optical fiber are spaced apart from each other in the vertical direction. The plurality of non-contact guides are arranged at certain intervals, such that the spacing width H between the plurality of non-contact guides is greater than the outer diameter D2 of each of the plurality of non-contact guides.

12. The optical fiber manufacturing apparatus according to claim 11, Furthermore, it includes a device for lateral movement of the movable non-contact guide. The movable non-contact guide can move laterally in the horizontal direction. The plurality of non-contact guides are configured to increase or decrease the winding length by adjusting the lateral displacement distance of the movable non-contact guides, thereby controlling the cooling capacity of the bare optical fiber.

13. The optical fiber manufacturing apparatus according to claim 11 or claim 12, wherein, The cooling mechanism has 3 to 15 of the aforementioned non-contact guides.

14. The optical fiber manufacturing apparatus according to claim 11 or claim 12, wherein, The winding diameter of each non-contact guide is between 50mm and 200mm.

15. The optical fiber manufacturing apparatus according to claim 11 or claim 12, Furthermore, it includes a gas supply device for supplying gas to the cooling mechanism. The cooling mechanism has at least three non-contact guides that spray the gas from the inside to the outside in a manner that non-contactly changes the direction of travel of the bare optical fiber. The gas supplied from the supply device to the non-contact guide is dry air with a dew point controlled below 0°C.

16. The optical fiber manufacturing apparatus according to claim 15, It further includes a filter disposed between the non-contact guide and the supply device. The filter is a gas filter with a filtration accuracy of less than 0.03 μm.

17. The optical fiber manufacturing apparatus according to claim 15, Furthermore, it includes an on / off valve disposed between the non-contact guide and the supply device, which adjusts the amount of dry air supplied to the non-contact guide. The aforementioned on / off valve is an on / off valve without a metal sliding part.

18. The optical fiber manufacturing apparatus according to claim 16, Furthermore, it includes an on / off valve disposed between the non-contact guide and the supply device, which adjusts the amount of dry air supplied to the non-contact guide. The aforementioned on / off valve is an on / off valve without a metal sliding part.

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