JP2023128450A - Non-contact guide and method for manufacturing optical fiber - Google Patents

Abstract

To easily maintain a non-contact guide.SOLUTION: A non-contact guide includes an inner member, a first flange and a second flange. The inner member has a plurality of gas ports capable of emitting gas on the outer peripheral surface; first and second flanges are stored so as to sandwich the inner member in a first direction intersecting the emitting direction of gas emitted from the plurality of gas ports; at least one of the first and second flanges is attached to the inner member so that a gap passing the gas emitted from the plurality of gas ports is provided between the outer edge part of the first flange and the outer edge part of the second flange; and at least one of the first and second flanges is movable in the direction of changing the width of the gap.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to a non-contact guide and a method of manufacturing an optical fiber.

Patent Document 1 discloses an example of a method for manufacturing an optical fiber wire. In this manufacturing method, an optical fiber preform is melted and drawn, and a coating layer is provided around the outer periphery of the drawn bare optical fiber. During this drawing, the direction of the bare optical fiber is changed by a direction changer (non-contact guide). Patent Document 2 and Patent Document 3 disclose other examples of a non-contact guide or a method of manufacturing an optical fiber using a non-contact guide.

Japanese Patent Application Publication No. 2016-124727 Japanese Unexamined Patent Publication No. 62-3037 Special Publication No. 2010-510957

When manufacturing an optical fiber using a non-contact guide, a drawn bare optical fiber is passed through a gap provided along the outer periphery of the non-contact guide to change its direction. At this time, the bare optical fiber may be broken in the non-contact guide, and the broken bare optical fiber may become stuck in the gap in the non-contact guide. In this case, it is not easy to remove the bare optical fibers stuck in the gap. Therefore, a non-contact guide that can be easily maintained is desired.

An object of the present disclosure is to provide a non-contact guide that can be easily maintained, and a method for manufacturing an optical fiber using the non-contact guide.

The present disclosure provides a non-contact guide that includes an internal member, a first flange, and a second flange. The internal member has a plurality of ejection ports capable of ejecting gas on the outer peripheral surface. The first flange and the second flange accommodate the internal member so as to sandwich the internal member in a first direction that intersects with a direction in which gas is ejected from the plurality of ejection ports. At least one of the first flange and the second flange has an internal member configured such that a gap is provided between the outer edge of the first flange and the outer edge of the second flange through which the gas ejected from the plurality of ejection ports passes. can be attached to. At least one of the first flange and the second flange is movable in a direction that changes the width of the gap.

The present disclosure provides a method for manufacturing an optical fiber using the above-described non-contact guide. The method for manufacturing an optical fiber includes a step of melting an optical fiber preform to form a bare optical fiber, a step of cooling the bare optical fiber, and a step of coating the bare optical fiber with a resin. In the cooling process, the bare optical fiber is passed through the gap in the non-contact guide, and the direction of the bare optical fiber is oriented around the non-contact guide while floating the bare optical fiber by blowing gas from the jet nozzle. change.

According to the present disclosure, maintenance of a non-contact guide can be easily performed.

FIG. 1 is a schematic diagram of an optical fiber manufacturing apparatus according to an embodiment. FIG. 2 is a perspective view of the non-contact guide. FIG. 3 is an exploded perspective view of the non-contact guide shown in FIG. 2 taken apart along the central axis C. FIG. 4 is a cross-sectional view of the non-contact guide shown in FIG. 2 taken along line IV-IV. FIG. 5 is an exploded perspective view of the internal member of the non-contact guide shown in FIG. 2 taken apart along the central axis C. FIG. 6 is an enlarged view of a region A surrounded by a broken line in the non-contact guide shown in FIG. FIG. 7 is a cross-sectional view of the non-contact guide shown in FIG. 2 taken along line VII-VII.

[Description of embodiments of the present disclosure]
First, the contents of the embodiments of the present disclosure will be listed and explained. A non-contact guide according to one embodiment includes an internal member, a first flange, and a second flange. The internal member has a plurality of ejection ports capable of ejecting gas on the outer peripheral surface. The first flange and the second flange accommodate the internal member so as to sandwich the internal member in a first direction that intersects with a direction in which gas is ejected from the plurality of ejection ports. At least one of the first flange and the second flange has an internal member configured such that a gap is provided between the outer edge of the first flange and the outer edge of the second flange through which the gas ejected from the plurality of ejection ports passes. is attached to. At least one of the first flange and the second flange is movable in a direction that changes the width of the gap.

In this non-contact guide, by moving at least one of the first flange and the second flange, the width of the gap for passing the bare optical fiber or bare optical fiber (hereinafter also referred to as "bare optical fiber, etc.") can be expanded. This makes it possible to easily perform maintenance of the non-contact guide, such as removing bare optical fibers or the like stuck in the gap and cleaning the surfaces of the first flange and second flange that define the gap. Furthermore, by changing the width of the gap, the pressure of the gas blown out from the non-contact guide can be adjusted. Therefore, gas at an appropriate pressure can be blown onto the bare optical fiber, etc., depending on the type and condition of the bare optical fiber, etc. that is passed through the gap.

As one embodiment, the outer circumferential surface of the internal member may have a buffer groove extending along the circumferential direction of the outer circumferential surface. The plurality of ejection ports may be provided at the bottom of the buffer groove. The buffer groove may be spatially connected to the gap in the jetting direction. In this case, the gas ejected from the plurality of ejection ports is dispersed in the circumferential direction in the buffer groove and then blown out from the gap to the outside. That is, the buffer groove reduces pressure unevenness of the gas blown out from the gap. Thereby, the direction of the bare optical fiber etc. can be changed more stably.

In one embodiment, the internal member is disk-shaped and may include a gas supply section to which gas is supplied from the outside, and a plurality of gas flow paths that respectively connect the gas supply section and the plurality of jet ports. . The gas supply may be located in a central portion of the inner member. The plurality of gas channels may be provided radially from the gas supply section to the plurality of jet ports. The plurality of jet ports may be located along the circumferential direction of the outer peripheral surface. In this case, the plurality of ejection ports are not concentrated in a specific area on the outer circumferential surface of the internal member, but are arranged in a dispersed manner, so that the pressure unevenness of the gas blown out from the gap is reduced. Thereby, the direction of the bare optical fiber etc. can be changed more stably.

In one embodiment, the gas flow path may have a circular cross section, and the inner diameter on the side of the ejection port may be larger than the inner diameter on the side of the gas supply section. In this case, by increasing the inner diameter on the side of the ejection port, the pressure unevenness of the gas blown out from the gap is reduced. Thereby, the direction of the bare optical fiber etc. can be changed more stably.

As one embodiment, the outer circumferential surface of the internal member may have a first cylindrical surface and a second cylindrical surface located across the plurality of jet ports in the first direction. The first flange may have a first accommodating portion defined by an inner circumferential surface that faces the first cylindrical surface when the internal member is accommodated. The second flange may have a second accommodating portion defined by an inner circumferential surface that faces the second cylindrical surface when the internal member is accommodated. A sealing member may be provided between the first cylindrical surface and the inner circumferential surface of the first accommodating portion, and between the second cylindrical surface and the inner circumferential surface of the second accommodating portion. In this case, the gap between the first cylindrical surface and the inner circumferential surface of the first accommodating section and the gap between the second cylindrical surface and the inner circumferential surface of the second accommodating section are each sealed by the sealing member, and the jet is ejected from the jet port. This prevents the gas from flowing into gaps other than those provided between the flanges. That is, the gas supplied to the non-contact guide is prevented from flowing into unintended gaps, and the gas can be efficiently used for floating bare optical fibers and the like.

In one embodiment, the device may further include a sealing member that seals at least one of the plurality of ejection ports. In this case, the outlet can be sealed with a sealing member so that gas does not leak out from the outlet that does not contribute to floating of the bare optical fiber. That is, the gas supplied to the non-contact guide can be efficiently used for floating the bare optical fiber.

In one embodiment, the Vickers hardness of at least one of the outer edge surface of the first flange and the outer edge surface of the second flange that defines the gap may be 800 HV or more. In this case, even if a bare optical fiber or the like comes into contact with the surface of each flange defining the gap, scratches are unlikely to occur. Therefore, the flow of gas blown out from the gap is less likely to be disturbed by scratches, and the gas is blown out stably. This makes it easier to maintain a floating state of a bare optical fiber or the like passed through the gap.

An optical fiber manufacturing method according to one embodiment is an optical fiber manufacturing method using the above-described non-contact guide. The method for manufacturing an optical fiber includes a step of melting an optical fiber preform and drawing a bare optical fiber, a step of cooling the bare optical fiber, and a step of coating the bare optical fiber with a resin. In the cooling process, the bare optical fiber is passed through the gap in the non-contact guide, and the direction of the bare optical fiber is oriented around the non-contact guide while floating the bare optical fiber by blowing gas from the jet nozzle. change. In this optical fiber manufacturing method, gas is directly blown onto the bare optical fiber through a gap in a non-contact guide. Thereby, the bare optical fiber is efficiently cooled.

As an embodiment of the optical fiber manufacturing method, in the above manufacturing method, at least one of the first flange and the second flange may be moved to adjust the width of the gap. In this case, the width of the gap can be adjusted depending on the diameter or type of the bare optical fiber, etc., and the pressure of the gas blown onto the bare optical fiber can be maintained at an appropriate level. Thereby, the floating state of the bare optical fiber can be maintained.

[Details of embodiments of the present disclosure]
Specific examples of the non-contact guide and the method of manufacturing an optical fiber according to the present disclosure will be described below with reference to the drawings. In the following description, the same elements or elements having the same function will be denoted by the same reference numerals, and redundant description will be omitted. Note that the present invention is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all changes within the meaning and scope equivalent to the scope of the claims.

With reference to FIG. 1, an optical fiber manufacturing method and an optical fiber manufacturing apparatus according to one embodiment will be described. FIG. 1 is a schematic diagram of an optical fiber manufacturing apparatus 1 according to an embodiment. As shown in FIG. 1, the manufacturing apparatus 1 heats and melts an optical fiber preform 2 to draw a bare optical fiber 10, and forms an optical fiber by providing a coating resin on the outer periphery of the bare optical fiber 10. This is an apparatus for manufacturing strands 11. The manufacturing apparatus 1 includes a drawing furnace 3, a cooling section 4, a coating section 5, a curing section 6, a roller directly below 7, a pulling roller 8, and a winding section 9, in the passage path of the bare optical fiber 10 and the bare optical fiber 11. It is equipped in order along.

The drawing furnace 3 forms a bare optical fiber 10 by heating and melting the optical fiber preform 2 so that it can be drawn along the vertical direction (direction X shown in FIG. 1). The drawing furnace 3 has a heater located around the optical fiber preform 2 . The optical fiber preform 2 is a glass body (preform) containing, for example, quartz glass. The bare optical fiber 10 is, for example, a glass wire including a core and a cladding covering the outer periphery of the core. The drawing furnace 3 heats the lower end of the optical fiber preform 2 with a heater to soften it, and then draws it. The drawn bare optical fiber 10 is sent to the cooling section 4.

The cooling unit 4 cools the bare optical fiber 10. The cooling unit 4 has an internal space S surrounded by an outer wall, for example, and the bare optical fiber 10 passes through the internal space S. The outer wall of the cooling unit 4 may be made of transparent glass or resin so that the inside of the cooling unit 4 can be confirmed. The cooling unit 4 may have an intake port (not shown) for injecting dry gas into the internal space S to cool the bare optical fiber 10. The heat of the bare optical fiber 10 is released to the outside using dry gas as a coolant. The cooling unit 4 has an exhaust port (not shown) for discharging dry gas. By surrounding it with an outer wall, it is possible to control the dew point inside the cooling unit 4 and prevent the optical fiber from scattering in the event of a disconnection. It is also possible to simply cool it. Further, even if it is surrounded by an outer wall, drying gas may not be injected into the internal space S, and the bare optical fiber 10 may be prevented from directly touching the outside air.

The bare optical fiber 10 passes through the internal space S in a meandering manner while its traveling direction is changed by a plurality of non-contact guides 20. The bare optical fiber 10 passes between each non-contact guide 20 in a direction oblique to the direction X and the direction Y. In this embodiment, the height direction of the manufacturing apparatus 1 is defined as a direction X, the width direction is defined as a direction Y, and the depth direction is defined as a direction Z. In this embodiment, direction X, direction Y, and direction Z are orthogonal to each other. The cooling unit 4 has seven non-contact guides 20. The non-contact guides 20A, 20B, 20C, 20D, 20E, 20F, and 20G are provided in this order on the running path of the bare optical fiber 10. Hereinafter, when it is not necessary to separately explain each non-contact guide 20, the non-contact guides 20 will be simply referred to collectively as non-contact guides 20. The number of non-contact guides 20 that the cooling unit 4 has may be plural and is not limited to seven. For example, the cooling unit 4 may have 3 or more and 15 or less non-contact guides 20.

Each non-contact guide 20 is a member that changes the moving direction of the bare optical fiber 10. The non-contact guide 20 is a disc-shaped member, and the bare optical fiber 10 is passed through a gap 80 (see FIG. 2) provided on the outer periphery. Each non-contact guide 20 may be movable along the direction Y so as to traverse the internal space S, or may be at a predetermined position without moving. When the non-contact guides 20 are movable, in this embodiment, the three non-contact guides 20 (non-contact guides 20B, 20D, 20F) move along the direction Y toward the right side of the paper in FIG. The bare optical fiber 10 cooled by the cooling section 4 is sent to the coating section 5. Details of the non-contact guide 20 will be described later.

The coating section 5 applies a coating resin to the outer periphery of the bare optical fiber 10. The coating resin is, for example, an ultraviolet curable resin. The coating part 5 may apply two different types of coating resin to the outer periphery of the bare optical fiber 10. The coating section 5 may, for example, apply a primary resin to the bare optical fiber 10 and then apply a secondary resin that is harder than the primary resin to the outside of the primary resin. The coating section 5 may apply the primary resin and the secondary resin to the bare optical fiber 10 substantially simultaneously. The bare optical fiber 10 coated with the coating resin is sent to the curing section 6 .

The curing section 6 cures the coating resin applied to the bare optical fiber 10 by irradiating it with ultraviolet rays. The curing section 6 has a light emitting element such as an ultraviolet lamp that emits ultraviolet light. When the coating resin applied to the bare optical fiber 10 is cured, the optical fiber 11 is completed. The completed optical fiber strand 11 is sent directly to the lower roller 7.

The direct roller 7 changes the moving direction of the optical fiber strand 11 from the direction along the direction X to a predetermined direction. The optical fiber strand 11 whose moving direction has been changed by the direct roller 7 is sent to the pulling roller 8 . The pulling roller 8 pulls and moves the optical fiber 11. By changing the rotational speed of the pulling roller 8, the moving speed of the optical fiber strand 11 may be adjustable. The optical fiber strand 11 is sent from the pulling roller 8 to the winding section 9, and is wound up by the winding section 9. With this, the manufacturing process of the optical fiber strand 11 is completed.

Next, the structure of the non-contact guide 20 will be explained with reference to FIGS. 2 to 6. FIG. 2 is a perspective view showing the non-contact guide 20. FIG. FIG. 3 is an exploded perspective view of the non-contact guide 20 taken apart along the central axis C. FIG. 4 is a cross-sectional view of the non-contact guide 20 taken along the line IV--IV shown in FIG. FIG. 5 is an exploded perspective view of the internal member 40 taken apart along the central axis C. FIG. 6 is an enlarged view of area A surrounded by broken lines shown in FIG.

The non-contact guide 20 is a member that changes the moving direction of the bare optical fiber 10. The non-contact guide 20 has a circular shape in plan view. The non-contact guide 20 has a gap 80 between the first flange 30 and the second flange 70, as shown in FIG. The gap 80 is provided in an annular shape along the outer periphery of the non-contact guide 20. The bare optical fiber 10 is passed through the gap 80. The gas introduced into the non-contact guide 20 is blown out from the gap 80. The blown gas is blown onto the bare optical fiber 10 passed through the gap 80. The bare optical fiber 10 is suspended by being blown with gas, so that it does not come into contact with the first flange 30 and the second flange 70 .

The non-contact guide 20 includes a first flange 30, an internal member 40, and a second flange 70, as shown in FIG. The first flange 30 is a member that is provided on the side of the non-contact guide 20 and accommodates a part of the internal member 40. The first flange 30 has a disk portion 31 having a circular shape in a plan view, and a peripheral wall portion 32 formed along the outer periphery of the disk portion 31. As shown in FIG. 3, the disk portion 31 is provided with one hole 31a and a plurality of screw holes 31b. The hole portion 31a is a through hole provided at the center of the disk portion 31. As shown in FIG. 4, the shaft portion 42 of the internal member 40 can be inserted through the hole portion 31a. The plurality of screw holes 31b are small-diameter through holes provided in a scattered manner so as to surround the hole portion 31a. A plurality of screws 90 can be inserted into each of the plurality of screw holes 31b. First flange 30 is secured to internal member 40 by screws 90 .

The peripheral wall portion 32 has an outer peripheral surface 32a facing the outside of the first flange 30, and an inner peripheral surface 32b facing the inside of the first flange 30 (the side of the first accommodating portion 33 described later). As shown in FIG. 4, the end of the outer circumferential surface 32a on the second flange 70 side is curved inward toward the central axis C and connected to the end of the inner circumferential surface 32b. That is, the end portion of the outer circumferential surface 32a has a curved shape in cross-sectional view. A gap 80 through which the bare optical fiber 10 passes is provided between the outer circumferential surface 32a and an outer circumferential surface 72a of a second flange 70, which will be described later. The Vickers hardness of the surface of the outer edge of the first flange 30 that defines the gap 80 (in this embodiment, the outer circumferential surface 32a) may be, for example, 800 HV or more, and more preferably 1500 HV or more. Vickers hardness is measured based on JISZ2244:2009. Specifically, a square pyramidal diamond indenter is pressed into the surface of the sample (in this embodiment, the outer peripheral surface 32a), and the Vickers hardness is determined from the diagonal length of the depression remaining on the surface.

The first flange 30 has a first accommodating portion 33 in which a part of the internal member 40 is accommodated. The first accommodating portion 33 is a substantially cylindrical space defined by the surface of the disk portion 31 and the inner circumferential surface 32b of the peripheral wall portion 32. When the internal member 40 is accommodated in the first accommodating portion 33, the inner circumferential surface 32b of the peripheral wall portion 32 faces the first cylindrical surface 50 of the internal member 40, as shown in FIG.

The internal member 40 is a member that blows out the introduced gas to the outside through a gap 80 between the first flange 30 and the second flange 70. The internal member 40 has a disk shape. The internal member 40 includes a main body portion 41 and a plate 60, as shown in FIG. As shown in FIG. 4, the main body portion 41 has a shaft portion 42 extending along the central axis C and a cylindrical portion 43 provided at one end of the shaft portion 42. A first gas flow path 44 extending along the central axis C is formed inside the shaft portion 42 . The first gas flow path 44 has an opening 42b in the end surface 42a of the shaft portion 42. The opening 42b is connected to an external gas supply source (such as an air pump). Gas supplied from the gas supply source flows into the first gas flow path 44 via the opening 42b. The gas supplied from the gas supply source may be, for example, dry gas that fills the internal space S (see FIG. 1) of the cooling unit 4. An end portion of the first gas flow path 44 located on the opposite side to the opening 42b is connected to a flow path branch portion 45 (gas supply portion) that the columnar portion 43 has. The gas that has flowed into the first gas flow path 44 is supplied to the flow path branch portion 45 . The first gas flow path 44 is formed such that its inner diameter gradually decreases from the opening 42b side toward the flow path branch portion 45 side.

The cylindrical portion 43 is a substantially cylindrical member, and is accommodated so as to be sandwiched between the first accommodating portion 33 and a second accommodating portion 73, which will be described later. The cylindrical portion 43 has a flow path branch portion 45 , a plurality of second gas flow paths 46 , and a plurality of jet ports 47 . The flow path branching portion 45 is an internal space having a substantially cylindrical shape, and branches the flow direction of the gas supplied from the first gas flow path 44 into a plurality of directions. A plurality of openings are provided at equal intervals along the circumferential direction of the inner circumferential surface 45a that defines the flow path branching portion 45. The plurality of openings are connected to the plurality of second gas flow paths 46, respectively.

The plurality of second gas flow paths 46 are provided radially from the flow path branch portion 45 toward the outer peripheral surface of the columnar portion 43 (see FIG. 7). As described above, one end of the second gas flow path 46 is connected to the opening provided on the inner circumferential surface 45a, and the other end is connected to the ejection port 47 provided on the outer circumferential surface of the cylindrical portion 43. A plurality of jet ports 47 are provided at equal intervals along the outer circumferential surface. The gas supplied from the first gas flow path 44 stays at the flow path branching portion 45 and is then branched off, flowing into the second gas flow path 46 . The gas that has flowed into the second gas flow path 46 is ejected from the ejection port 47. The gas ejected from the ejection port 47 is blown onto the bare optical fiber 10 from the gap 80 via a buffer groove 51, which will be described later. In this embodiment, the cross section of the second gas flow path 46 is circular. The portion of the second gas flow path 46 located on the side of the jet port 47 is formed to have a larger inner diameter than the portion located on the side of the inner circumferential surface 45a. The shape of the second gas flow path 46 is not limited to the shape described above. The cross section of the second gas flow path 46 may be elliptical or polygonal. The second gas flow path 46 may be a straight flow path with a constant cross-sectional area.

As shown in FIG. 4, the outer peripheral surface of the cylindrical portion 43 has a first cylindrical surface 50, a buffer groove 51, and a second cylindrical surface 52 in this order along the central axis C. The first cylindrical surface 50 is located closer to the shaft portion 42 than the buffer groove 51 is. When the internal member 40 is accommodated in the first accommodating portion 33 , the first cylindrical surface 50 faces the inner circumferential surface 32 b of the peripheral wall portion 32 . The first cylindrical surface 50 has a first groove portion 54, as shown in FIG. The first groove portion 54 is a recessed portion recessed toward the inside of the internal member 40 (toward the central axis C side shown in FIG. 4), and is continuously provided in an annular shape along the first cylindrical surface 50. The first groove portion 54 is a rectangular groove with a bottom, and is defined by a bottom surface 54a and a pair of opposing side surfaces 54b.

A first seal member 65 is fitted into the first groove portion 54 . The first seal member 65 may be an O-ring made of elastic resin, for example. The first seal member 65 seals the gap between the first cylindrical surface 50 and the inner peripheral surface 32b of the peripheral wall portion 32, and prevents the gas ejected from the jet port 47 from flowing into the gap. The width of the first groove portion 54 in the direction along the central axis C (the distance between the pair of side surfaces 54b) is slightly larger than the width of the cross section of the first seal member 65. Thereby, the first flange 30 can be smoothly moved relative to the internal member 40.

The buffer groove 51 is a concave portion that is depressed toward the central axis C, and is continuously provided in an annular shape along the outer peripheral surface of the internal member 40. The buffer groove 51 is a bottomed rectangular groove, and a plurality of ejection ports 47 are provided on the bottom surface. The buffer groove 51 disperses the gas ejected from the plurality of ejection ports 47 in the circumferential direction, and then blows the gas out from the gap 80 between the first flange 30 and the second flange 70 .

The second cylindrical surface 52 is located further away from the shaft portion 42 than the buffer groove 51 is. When the internal member 40 is accommodated in the second accommodating portion 73 described later, the second cylindrical surface 52 faces the inner circumferential surface 72b of the peripheral wall portion 72. The second cylindrical surface 52 has a second groove 56, as shown in FIG. The second groove portion 56 is a recessed portion recessed inside the internal member 40 (on the central axis C side shown in FIG. 4), and is continuously provided in an annular shape along the second cylindrical surface 52. The second groove portion 56 is a bottomed rectangular groove defined by a bottom surface 56a and a pair of opposing side surfaces 56b.

A second seal member 66 is fitted into the second groove portion 56 . The second seal member 66 may be an O-ring made of elastic resin, for example. The second seal member 66 seals the gap between the second cylindrical surface 52 and the inner peripheral surface 72b of the peripheral wall portion 72, and prevents the gas ejected from the jet port 47 from flowing into the gap. The width of the second groove portion 56 in the direction along the central axis C (the distance between the pair of side surfaces 56b) is slightly larger than the width of the cross section of the second seal member 66. Thereby, the second flange 70 can be smoothly moved relative to the internal member 40.

The internal member 40 has a plate accommodating portion 57, as shown in FIG. The plate accommodating portion 57 is a substantially cylindrical space that can accommodate the plate 60. The inner diameter of the plate accommodating portion 57 is larger than the inner diameter of the flow path branching portion 45 . An inner circumferential surface 57 a defining the plate accommodating portion 57 and an inner circumferential surface 45 a defining the flow path branching portion 45 are connected by an inner circumferential surface 58 . The inner surface 58 extends along a plane perpendicular to the central axis C, and is provided in an annular shape surrounding the central axis C. The inner surface 58 is provided with a plurality of screw holes 58a into which a plurality of screws 91 for fixing the plate 60 to the main body portion 41 are respectively attached.

As shown in FIG. 5, the plate 60 is a plate member having a circular shape in plan view. The plate 60 is accommodated in the plate accommodating portion 57 of the main body portion 41 . The plate 60 has a first side surface 61, a second side surface 62, and an outer peripheral surface 63. The first side surface 61 and the second side surface 62 are surfaces forming side surfaces of the plate 60 in the direction along the central axis C. The outer peripheral surface 63 is a surface connecting the outer edge of the first side surface 61 and the outer edge of the second side surface 62. When the plate 60 is accommodated in the plate accommodating portion 57 , a region of the first side surface 61 closer to the outer circumferential surface 63 contacts the inner surface 58 of the plate accommodating portion 57 . Further, the central region of the first side surface 61 does not contact the inner surface 58 and functions as a wall surface defining the flow path branching portion 45 .

As shown in FIG. 4, the first side surface 61 is provided with a third groove portion 61a. The third groove portion 61a is continuously provided in an annular shape surrounding the central axis C. The third groove portion 61a is a bottomed rectangular groove, into which the third seal member 67 is fitted. The third seal member 67 may be an O-ring made of elastic resin, for example. The third seal member 67 seals the gap between the inner side surface 58 and the first side surface 61, and prevents the gas supplied to the flow path branching part 45 from leaking to the outside from the gap.

As shown in FIG. 5, the plate 60 is provided with a plurality of through holes 64 that penetrate from the first side surface 61 toward the second side surface 62. The plurality of through holes 64 are arranged in a ring shape surrounding the central axis C. A plurality of screws 91 are inserted into the plurality of through holes 64, respectively. The tip of the screw 91 inserted into the through hole 64 is attached to the screw hole 58a of the main body 41. Thereby, the plate 60 is fixed to the main body 41 while being accommodated in the plate accommodating portion 57 .

The second flange 70 is a member that is provided on the side of the non-contact guide 20 and accommodates a portion of the internal member 40. The second flange 70 has the same configuration as the first flange 30. As shown in FIG. 3, the second flange 70 is located on the opposite side of the first flange 30 in the direction along the central axis C, and is attached to the internal member 40 in the opposite direction to the first flange 30. Good too. That is, in this embodiment, one flange can be used for both the first flange 30 and the second flange 70, so there is no need to prepare flanges of different shapes for the first flange 30 and the second flange 70, respectively. good.

The second flange 70 has a disk portion 71 having a circular shape in plan view, and a peripheral wall portion 72 formed along the outer periphery of the disk portion 71. As shown in FIG. 3, the disk portion 71 is provided with one hole 71a and a plurality of screw holes 71b. The hole portion 71a is a through hole provided at the center of the disk portion 71. The plurality of screw holes 71b are small-diameter through holes provided in a scattered manner so as to surround the hole portion 31a. When the second flange 70 is replaced with the first flange 30, the shaft portion 42 of the internal member 40 can be inserted into the hole 71a, and a plurality of screws 90 can be inserted into the plurality of screw holes 71b. It is possible to insert it.

The peripheral wall portion 72 has an outer peripheral surface 72a facing the outside of the second flange 70, and an inner peripheral surface 72b facing the inside of the second flange 70 (the side of the second accommodating portion 73 described later). As shown in FIG. 4, the end of the outer circumferential surface 72a on the first flange 30 side is curved inward toward the central axis C and connected to the end of the inner circumferential surface 72b. That is, the end portion of the outer circumferential surface 72a has a curved shape in cross-sectional view. A gap 80 is provided between the outer circumferential surface 72a of the second flange 70 and the outer circumferential surface 32a of the first flange 30, as described above, through which the bare optical fiber 10 passes. The Vickers hardness of the surface of the outer edge of the second flange 70 that defines the gap 80 (in this embodiment, the outer circumferential surface 72a) may be, for example, 800 HV or more, and more preferably 1500 HV or more. The method for measuring the Vickers hardness is the same as the method for measuring the Vickers hardness of the surface of the first flange 30 described above.

The second flange 70 has a second accommodating portion 73 in which a portion of the internal member 40 is accommodated. The second accommodating portion 73 is a substantially cylindrical space defined by the surface of the disk portion 71 and the inner circumferential surface 72b of the peripheral wall portion 72. When the internal member 40 is accommodated in the second accommodating portion 73, the inner circumferential surface 72b of the peripheral wall portion 72 faces the second cylindrical surface 52 of the internal member 40, as shown in FIG. The second flange 70 is not fixed to the internal member 40 and is movable relative to the internal member 40. The second flange 70 may be detachably attached to the internal member 40. Since the second flange 70 is removable, maintenance of the gap 80 (removal of the bare optical fiber 10 stuck in the gap 80, checking for scratches on the outer peripheral surfaces 32a, 72a, etc.) can be easily performed. .

The configuration of the non-contact guide 20 when the bare optical fiber 10 is passed through the gap 80 will be described with reference to FIGS. 6 and 7. FIG. 7 is a cross-sectional view of the non-contact guide 20 taken along line VII-VII shown in FIG. The first flange 30 and the second flange 70 are attached to the internal member 40 such that a gap 80 is provided between the outer edge of the first flange 30 and the outer edge of the second flange 70, as shown in FIG. . In this embodiment, a gap 80 is provided between the outer peripheral surface 32a of the first flange 30 and the outer peripheral surface 72a of the second flange 70.

The gap 80 is provided so as to surround the central axis C along the circumferential direction of the non-contact guide 20, as shown in FIG. The bare optical fiber 10 is passed through the gap 80. Specifically, the bare optical fiber 10 enters the gap 80 from the input line part 81, moves along the gap 80, and then exits from the output line part 82. In the example shown in FIG. 7, the bare optical fiber 10 moves through approximately one half of the area in the circumferential direction of the gap 80. In the example shown in FIG. That is, the moving direction of the bare optical fiber 10 is changed by about 180 degrees by the non-contact guide 20. The positions of the incoming line part 81 and the outgoing line part 82 described above are determined by the amount of change in the moving direction of the bare optical fiber 10. In this embodiment, the moving direction of the bare optical fiber 10 is changed by about 180 degrees as described above. Therefore, the outgoing line part 82 is set at a position shifted from the incoming line part 81 by approximately one half of the length of the gap 80 in the circumferential direction. For example, when changing the moving direction of the bare optical fiber 10 by about 90 degrees, the outgoing line part 82 is shifted from the incoming line part 81 by about one quarter of the length in the circumferential direction of the gap 80 (in FIG. (at the top of the gap 80).

The gap 80 is spatially connected to the buffer groove 51 and the jet port 47, as shown in FIG. As a result, the gas ejected from the ejection port 47 passes through the buffer groove 51 and is blown out from the gap 80 to the outside of the non-contact guide 20 . The gas blown out from the gap 80 is blown onto the bare optical fiber 10 passed through the gap 80. Due to the gas wind pressure, the bare optical fiber 10 is maintained floating from the outer circumferential surface 32a of the first flange 30 and the outer circumferential surface 72a of the second flange 70. That is, the bare optical fiber 10 is in a floating state in the gap 80.

The second flange 70 is not fixed to the internal member 40 and is movable in a direction that changes the width W of the gap 80. The width W of the gap 80 refers to the distance between the closest portions of the outer circumferential surface 32a of the first flange 30 and the outer circumferential surface 72a of the second flange 70, which face each other. The method of moving the second flange 70 is not limited. As an example, the width W of the gap 80 may be changed by moving the second flange 70 in the direction along the central axis C. As another example, the width W of the gap 80 may be changed by rotating the second flange 70 in the direction of the arrow T around the virtual point P shown in FIG. In this case, the width W of the part of the gap 80 that is close to the virtual point P (the lower part in FIG. 4) becomes smaller, and the width W of the part that is farther from the virtual point P (the upper part in FIG. 4) changes to become larger. do.

The pressure of the gas blown out from the gap 80 (blowout pressure) depends on factors such as the pressure (inlet pressure) of the gas supplied to the first gas flow path 44 (see FIG. 4), the width W of the gap 80, etc. It changes and is also influenced 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 (circle B shown by a solid line and a broken line in FIG. 7) when the bare optical fiber 10 is passed around the entire circumference of the gap 80. Refers to the diameter. The blowing pressure is optimized by adjusting each of the above factors according to the tension of the bare optical fiber 10, the diameter of the bare optical fiber 10, or the like.

Generally, in the process of increasing the linear speed (moving speed) of the bare optical fiber 10, the tension applied to the bare optical fiber 10 is small, and when the pressure of the blown gas is large, the bare optical fiber 10 resonates and becomes non-conductive. It comes into contact with the contact guide 20. Therefore, in the process of increasing the linear speed of the bare optical fiber 10, the blowing pressure is reduced. On the other hand, when the wire speed is stable, the tension of the bare optical fiber 10 is maintained high, so the blowing pressure is increased. As a method of increasing the blowing pressure, for example, a method of increasing the inlet pressure or decreasing the width W of the gap 80 can be adopted.

For example, when a bare optical fiber 10 with a diameter of 125 μm is suspended, the width W of the gap 80 is adjusted so that the inlet pressure becomes an optimal pressure condition in the range of 50 kPa or more and 200 kPa or less. At this time, the flow rate of the gas blown out from the gap 80 of one non-contact guide 20 may be 30 L/min or more and 150 L/min or less.

When adjusting the blowout pressure to an appropriate level, first, while a constant flow rate of gas is flowing, the width W of the gap 80 is reduced until the inlet pressure reaches a predetermined value (for example, 200 kPa). At this time, the width W of the gap 80 may be reduced, for example, by bringing the second flange 70 closer toward the first flange 30. Thereafter, the width W of the gap 80 is gradually increased until the blowing pressure reaches an optimum level (a size at which the bare optical fiber 10 is properly suspended). At this time, the width W of the gap 80 may be increased, for example, by separating the second flange 70 from the first flange 30. This blowing pressure adjustment work may be performed for each non-contact guide 20 shown in FIG. 1. Further, the adjustment work may be performed at any timing in the manufacturing process of the optical fiber 11.

The non-contact guide 20 has a sealing member 68, as shown in FIG. For convenience of explanation, illustration of the sealing member 68 is omitted in figures other than FIG. 7. The sealing member 68 seals at least one of the plurality of jet ports 47 and prevents gas from passing through the jet port 47 . The sealing member 68 may be made of an elastic material such as resin, for example. The sealing member 68 has an elongated shape and is fitted into a part of the buffer groove 51 so as to close the ejection port 47 . In this embodiment, the sealing member 68 is fitted into approximately half the area of the buffer groove 51 . Gas does not flow into some of the second gas channels 46 whose jet ports 47 are sealed by the sealing member 68, and gas flows into other second gas channels 46 whose jet ports 47 are not sealed. .

In the direction from the central axis C toward the outer periphery of the non-contact guide 20 (radial direction of the non-contact guide 20), most of the sealing member 68 is provided so as not to overlap with the bare optical fiber 10 passed through the gap 80. It will be done. In the example shown in FIG. 7, the portion of the sealing member 68 excluding both ends is provided so that the position in the circumferential direction does not overlap with the bare optical fiber 10 passed through the gap 80. Further, a pair of gas escape portions 84 are provided between both ends of the sealing member 68 and the bare optical fiber 10, through which the gas inside the buffer groove 51 flows out. By smoothly flowing out the gas accumulated in the buffer groove 51 from the gas escape part 84, excessively high-pressure gas is not blown out from the gap 80, and the bare optical fiber 10 can be suspended in a stable state. The shape of the sealing member 68 is not limited to that described above. In this embodiment, the plurality of ejection ports 47 are sealed by one continuous sealing member 68, but for example, the plurality of ejection ports 47 are each sealed by a plurality of separate sealing members 68. may have been done.

As described above, according to the non-contact guide 20 according to the present embodiment, the width of the gap 80 can be increased by moving at least one of the first flange 30 and the second flange 70. Thereby, maintenance of the non-contact guide 20 such as removing the bare optical fiber 10 stuck in the gap 80 and cleaning the surfaces of the first flange 30 and the second flange 70 that define the gap 80 can be easily performed. Further, by changing the width of the gap 80, the pressure of the gas blown out from the non-contact guide 20 can be adjusted. Therefore, gas at an appropriate pressure can be blown onto the bare optical fiber 10 according to the type and condition of the bare optical fiber 10 passed through the gap 80.

In this embodiment, the outer peripheral surface of the internal member 40 may have a buffer groove 51 extending along the circumferential direction of the outer peripheral surface. The plurality of ejection ports 47 may be provided at the bottom of the buffer groove 51. The buffer groove 51 may be spatially connected to the gap 80 in the ejection direction. In this case, the gas ejected from the plurality of ejection ports 47 is dispersed in the buffer groove 51 and then blown out from the gap 80 to the outside. That is, the pressure unevenness of the gas blown out from the gap 80 is reduced by the buffer groove 51. Thereby, the direction of the bare optical fiber 10 can be changed more stably.

In this embodiment, the internal member 40 has a disk shape, and connects a flow path branch part 45 (gas supply part) to which gas is supplied from the outside, and the flow path branch part 45 and a plurality of jet ports 47, respectively. It may have a plurality of second gas flow paths 46 (gas flow paths). The flow path branch portion 45 may be located in the central portion of the internal member 40. The plurality of second gas flow paths 46 may be provided radially from the flow path branch portion 45 to the plurality of jet ports 47 . The plurality of jet ports 47 may be located along the circumferential direction of the outer peripheral surface. In this case, the plurality of ejection ports 47 are not concentrated in a specific area on the outer circumferential surface of the internal member 40 but are arranged in a dispersed manner, so that the pressure unevenness of the gas blown out from the gap 80 is reduced. Thereby, the direction of the bare optical fiber 10 can be changed more stably.

In the present embodiment, the second gas flow path 46 (gas flow path) has a circular cross section, and the inner diameter on the jet port 47 side may be larger than the inner diameter on the flow path branch portion 45 side. In this case, by increasing the inner diameter on the side of the ejection port 47, the pressure unevenness of the gas blown out from the gap 80 is reduced. Thereby, the direction of the bare optical fiber 10 can be changed more stably.

In this embodiment, the outer circumferential surface of the internal member 40 may have a first cylindrical surface 50 and a second cylindrical surface 52 located across the plurality of jet ports 47 in the first direction. The first flange 30 may have a first accommodating portion 33 defined by an inner circumferential surface 32b that faces the first cylindrical surface 50 when the internal member 40 is accommodated. The second flange 70 may have a second accommodating portion 73 defined by an inner circumferential surface 72b that faces the second cylindrical surface 52 when the internal member 40 is accommodated. A first seal member 65, A second seal member 66 (seal member) may be provided. In this case, the gap between the first cylindrical surface 50 and the inner circumferential surface 32b of the first accommodating part 33 and the gap between the second cylindrical surface 52 and the inner circumferential surface 72b of the second accommodating part 73 are the first seal member 65, respectively. , is sealed by the second seal member 66, and gas injected from the jet port 47 is prevented from flowing into gaps other than the gaps provided between the flanges. That is, the gas supplied to the non-contact guide 20 is prevented from flowing into an unintended gap, and the gas can be efficiently used for floating the bare optical fiber 10.

This embodiment may further include a sealing member 68 that seals at least one of the plurality of jet ports 47 . In this case, the spout 47 that does not contribute to floating of the bare optical fiber 10 can be sealed with a sealing member 68 so that gas does not leak out from the spout 47 . That is, the gas supplied to the non-contact guide 20 can be efficiently used for floating the bare optical fiber 10.

In this embodiment, the Vickers hardness of at least one of the outer edge surface of the first flange 30 and the outer edge surface of the second flange 70 that define the gap 80 may be 800 HV or more. In this case, even if the bare optical fiber 10 comes into contact with the surface of each flange defining the gap 80, scratches are unlikely to occur. Therefore, the flow of gas blown out from the gap 80 is less likely to be disturbed by scratches, and the gas is blown out stably. This makes it easier to maintain the floating state of the bare optical fiber 10 passed through the gap 80.

As described above, according to the method for manufacturing the optical fiber strand 11 according to the present embodiment, gas is directly blown onto the bare optical fiber 10 from the gap 80 of the non-contact guide 20. Thereby, the bare optical fiber 10 is efficiently cooled.

Further, in this embodiment, at least one of the first flange 30 and the second flange 70 may be moved to adjust the width of the gap 80. In this case, the width of the gap 80 can be adjusted depending on the diameter or type of the bare optical fiber 10, and the pressure of the gas blown onto the bare optical fiber 10 can be maintained at an appropriate level. Thereby, the floating state of the bare optical fiber 10 can be maintained.

Although the embodiments according to the present disclosure have been described in detail above, the present invention is not limited to the above embodiments and can be applied to various embodiments.

For example, the first flange 30 may not be fixed to the internal member 40 but may be movably attached to the internal member 40. In this case, the size of the width W of the gap 80 may be adjusted by moving the first flange 30 together with the second flange 70 or instead of the second flange 70. By fixing either the first flange 30 or the second flange 70 to the internal member 40, the movement mechanism for moving the flange can be simplified. The first flange 30 and the second flange 70 only need to be movable relative to the internal member 40, but the first flange 30 is fixed to the internal member 40, and the second flange 70 is fixed to the internal member 40. If the flange can be moved relative to the flange, the moving mechanism for moving the flange can be further simplified.

1... Manufacturing equipment 2... Optical fiber preform 3... Drawing furnace 4... Cooling section 5... Coating section 6... Curing section 7... Directly below roller 8... Traction roller 9... Winding section 10... Optical fiber bare wire 11... Optical fiber element Wires 20, 20A, 20B, 20C, 20D, 20E, 20F, 20G...Non-contact guide 30...First flange 31, 71...Disc part 31a, 71a...Hole part 31b, 71b...Screw hole 32, 72...Surrounding wall part 32a , 72a...outer circumferential surface 32b, 72b...inner circumferential surface 33...first housing part 40...internal member 41...main body part 42...shaft part 42a...end surface 42b...opening 43...cylindrical part 44...first gas flow path 45...flow Path branching portion 45a...inner peripheral surface 46...second gas flow path 47...spout port 50...first cylindrical surface 51...buffer groove 52...second cylindrical surface 54...first groove portions 54a, 56a...bottom surface 54b, 56b...side surface 56...Second groove 57...Plate accommodating part 57a...Inner peripheral surface 58...Inner surface 58a...Screw hole 60...Plate 61...First side 61a...Third groove 62...Second side 63...Outer peripheral surface 64...Through hole 65 ...First seal member 66...Second seal member 67...Third seal member 68...Sealing member 70...Second flange 73...Second accommodating part 80...Gap 81...Incoming line part 82...Outgoing line part 84...Gas escape part 90, 91...Screw A...Area C...Central axis D1...Wound diameter P...Virtual point S...Internal space T...Arrow W...Width

Claims (9)

an internal member having a plurality of ejection ports capable of ejecting gas on an outer peripheral surface;
a first flange and a second flange that accommodate the internal member so as to sandwich the internal member in a first direction intersecting the jetting direction of the gas jetted from the plurality of jetting ports;
Equipped with
At least one of the first flange and the second flange is provided with a gap between an outer edge of the first flange and an outer edge of the second flange through which the gas ejected from the plurality of ejection ports passes. attached to the internal member so that the
A non-contact guide, wherein at least one of the first flange and the second flange is movable in a direction that changes the width of the gap. The outer circumferential surface of the internal member has a buffer groove extending along the circumferential direction of the outer circumferential surface,
The plurality of jet ports are provided at the bottom of the buffer groove,
The buffer groove is spatially connected to the gap in the jetting direction.
The non-contact guide according to claim 1. The internal member has a disk shape, and has a gas supply section to which the gas is supplied from the outside, and a plurality of gas flow paths that respectively connect the gas supply section and the plurality of jet ports,
The gas supply section is located in a central portion of the internal member,
The plurality of gas flow paths are provided radially from the gas supply section to the plurality of jet ports,
The plurality of jet ports are located along the circumferential direction of the outer peripheral surface,
The non-contact guide according to claim 1 or claim 2. The gas flow path has a circular cross section, and the inner diameter on the side of the jet port is larger than the inner diameter on the side of the gas supply part.
The non-contact guide according to claim 3. The outer circumferential surface of the internal member has a first cylindrical surface and a second cylindrical surface located across the plurality of jet ports in the first direction,
The first flange has a first accommodating portion defined by an inner circumferential surface that faces the first cylindrical surface when the internal member is accommodated,
The second flange has a second accommodating portion defined by an inner circumferential surface that faces the second cylindrical surface when the internal member is accommodated,
Seal members are provided between the first cylindrical surface and the inner circumferential surface of the first accommodating portion, and between the second cylindrical surface and the inner circumferential surface of the second accommodating portion, respectively.
The non-contact guide according to any one of claims 1 to 4. further comprising a sealing member that seals at least one of the plurality of jet ports;
The non-contact guide according to any one of claims 1 to 5. Vickers hardness of at least one of the outer edge surface of the first flange and the outer edge surface of the second flange that defines the gap is 800 HV or more;
The non-contact guide according to any one of claims 1 to 6. A method for manufacturing an optical fiber using the non-contact guide according to any one of claims 1 to 7, comprising:
a step of melting an optical fiber base material and drawing a bare optical fiber;
cooling the bare optical fiber;
Coating the bare optical fiber with resin;
Equipped with
In the cooling step, the bare optical fiber is passed through the gap of the non-contact guide, and the bare optical fiber is suspended by blowing the gas ejected from the spout, while the non-contact guide is pivoted. changing the direction of the bare optical fiber as;
Method of manufacturing optical fiber. moving at least one of the first flange and the second flange to adjust the width of the gap;
The method for manufacturing an optical fiber according to claim 8.

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