Coating apparatus and coating method

Abstract

To provide a coating device capable of uniformly controlling the flow of a resin coated on a glass fiber in the circumferential direction of the glass fiber and reducing the size of the device in the vertical direction.SOLUTION: A coating device includes: a fiber passage through which a glass fiber passes downward in the vertical direction; a first passage circulating a first resin toward the fiber passage and including a first branch passage for horizontally branching the first resin horizontally moving; a first temperature controller arranged along the first passage and for controlling the temperature of the first passage; a second passage circulating a second resin toward the fiber passage, including a second branch passage for horizontally branching the second resin horizontally moving and positioned below the first passage; and a second temperature controller arranged along the second passage and for controlling the temperature of the second passage.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a coating device and a coating method.

Background Art

[0002] Patent Document 1 discloses a resin coating device. This device includes a first die that applies a first resin to the outside of a drawn glass fiber, and a second die that applies a second resin to the outside of the first resin. The first die and the second die are integrally assembled, and the first resin and the second resin are collectively applied to the glass fiber. Further, this device includes a first fluid circulation unit and a second fluid circulation unit. The first fluid circulation unit is provided around the first die, and adjusts the temperature of the first resin supplied to the first die by controlling the temperature of the circulating fluid. The second fluid circulation unit is provided around the second die, and adjusts the temperature of the second resin supplied to the second die by controlling the temperature of the circulating fluid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the technology related to the above resin coating device, it is desirable that the flow of the resin applied to the glass fiber is uniformly adjusted in the circumferential direction of the glass fiber. Further, in this technology, it is desirable to reduce the size of the device in the vertical direction.

[0005] An object of the present disclosure is to provide a coating device that can uniformly adjust the flow of the resin applied to the glass fiber in the circumferential direction of the glass fiber and can reduce the size of the device in the vertical direction.

Means for Solving the Problems

[0006] The coating device according to an embodiment of the present disclosure includes a fiber passage through which glass fibers pass vertically downward, a flow path for flowing a first resin toward the fiber passage, the first flow path having a first branch path that horizontally branches the first resin moving in the horizontal direction, a first temperature adjuster disposed along the first flow path for adjusting the temperature of the first flow path, a flow path for flowing a second resin toward the fiber passage, the second flow path having a second branch path that horizontally branches the second resin moving in the horizontal direction and being located below the first flow path, and a second temperature adjuster disposed along the second flow path for adjusting the temperature of the second flow path.

Effects of the Invention

[0007] According to the coating device of the present disclosure, the flow of the resin applied to the glass fiber can be uniformly adjusted in the circumferential direction of the glass fiber, and the vertical size of the device can be reduced.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] [Description of Embodiments of the Present Disclosure] First, the content of the embodiments of the present disclosure will be listed and described. A coating apparatus according to an embodiment of the present disclosure includes a fiber passage through which glass fibers pass vertically downward, a flow path for flowing a first resin toward the fiber passage, the first flow path having a first branch path for horizontally branching the first resin moving in the horizontal direction, a first temperature adjuster disposed along the first flow path for adjusting the temperature of the first flow path, a flow path for flowing a second resin toward the fiber passage, the second flow path having a second branch path for horizontally branching the second resin moving in the horizontal direction and being located below the first flow path, and a second temperature adjuster disposed along the second flow path for adjusting the temperature of the second flow path.

[0010] In the above coating apparatus, the first resin that flows through the first flow path and is temperature-adjusted by the first temperature adjuster is applied to the glass fibers passing through the fiber passage. Further, the second resin that flows through the second flow path and is temperature-adjusted by the second temperature adjuster is further applied to the glass fibers to which the first resin has been applied. In the first flow path and the second flow path, a first branch path and a second branch path for horizontally branching the resin are respectively formed. Therefore, flow paths can be formed from a plurality of positions in the circumferential direction toward the fiber passage. Accordingly, the flow of the resin applied to the glass fibers can be uniformly adjusted in the circumferential direction of the glass fibers. Further, since the branch paths branch only in the horizontal direction, the size of the apparatus in the vertical direction can be reduced.

[0011] The first flow path and the first temperature adjuster in one example may form a first annular body having an annular shape disposed around the fiber passage. The second flow path and the second temperature adjuster may form a second annular body having an annular shape disposed below the first annular body around the fiber passage. In this configuration, it is easy to evenly arrange each flow path and each temperature adjuster around the fiber passage.

[0012] In the vertical direction, a heat insulating layer may be formed between the first annular body and the second annular body. In this configuration, it is suppressed that the heat of the first temperature adjuster affects the second annular body and that the heat of the second temperature adjuster affects the first annular body.

[0013] The first flow path and the second flow path are located between the first temperature regulator and the second temperature regulator in the vertical direction. The temperature of the first flow path may be adjusted by the first temperature regulator, and the temperature of the second flow path may be adjusted by the second temperature regulator. In this configuration, it is possible to suppress the heat of the first temperature regulator from affecting the second annular body and the heat of the second temperature regulator from affecting the first annular body.

[0014] The heat source in the first temperature regulator is a heater arranged along the first flow path, and the heat source in the second temperature regulator may be a third flow path arranged along the second flow path through which the temperature-adjusted fluid flows. In this configuration, for example, the first resin flowing through the first flow path can be easily adjusted to a higher temperature than the second resin.

[0015] The first branch path has one inlet and two outlets, and the cross-sectional area of each of the two outlets may be half of the cross-sectional area of one inlet. In this configuration, the first resin can be evenly branched by the first branch path.

[0016] The first branch path has one inlet and a plurality of outlets, and the cross-sectional area of one inlet may be equal to the sum of the cross-sectional areas of each of the plurality of outlets. In this configuration, the first resin can be evenly branched by the first branch path.

[0017] The first flow path includes four outlets branched by the first branch path, and the four outlets may be evenly arranged in the circumferential direction around the fiber passage. In this configuration, the flow of the first resin in the vicinity of the fiber passage is likely to be uniform in the circumferential direction. Note that "evenly in the circumferential direction" includes not only the case of being strictly equidistant but also substantially evenly spaced and regarded as substantially equidistant.

[0018] The second branch path has one inlet and two outlets, and the cross-sectional area of each of the two outlets may be half of the cross-sectional area of one inlet. In this configuration, the second resin can be evenly branched by the second branch path.

[0019] The second branch path has one inlet and a plurality of outlets, and the cross-sectional area of the one inlet may be equal to the sum of the cross-sectional areas of the plurality of outlets. In this configuration, the second resin can be evenly branched by the second branch path.

[0020] The second flow path includes four outlets branched by the second branch path, and the four outlets may be evenly arranged in the circumferential direction around the fiber passage. In this configuration, the flow of the second resin in the vicinity of the fiber passage is likely to be uniform in the circumferential direction. In this case as well, "evenly in the circumferential direction" includes not only the case of being strictly equidistant but also substantially evenly spaced and regarded as substantially equidistant.

[0021] A coating method according to an embodiment includes a step of passing a glass fiber vertically downward through a fiber passage, a step of flowing a first resin through a first flow path that branches in the horizontal direction and adjusting the temperature by a first temperature adjuster to adjust the temperature of the first resin to a first temperature, a step of flowing a second resin through a second flow path that is located below the first flow path and branches in the horizontal direction and adjusting the temperature by a second temperature adjuster to adjust the temperature of the second resin to a second temperature, a step of coating the glass fiber moving in the fiber passage with the first resin that has flowed through the first flow path, and a step of coating the glass fiber that has moved in the fiber passage and has the first resin coated thereon with the second resin that has flowed through the second flow path.

[0022] In the above coating method, the first resin that has flowed through the first flow path and has been adjusted to the first temperature is coated on the glass fiber passing through the fiber passage. Further, the second resin that has flowed through the second flow path and has been adjusted to the second temperature is further coated on the glass fiber on which the first resin has been coated. In the first flow path and the second flow path, since the resin is branched, flow paths can be formed from a plurality of positions in the circumferential direction toward the fiber passage. Therefore, the flow of the resin coated on the glass fiber can be adjusted uniformly in the circumferential direction of the glass fiber. Also, since the resin is branched only in the horizontal direction, the size of the apparatus in the vertical direction can be reduced.

[0023] [Details of Embodiments of the Present Disclosure] A specific example of the coating apparatus according to the present disclosure will be described below with reference to the drawings. The coating apparatus is an apparatus for manufacturing an optical fiber element wire in which a resin is coated on the surface of a glass fiber, and may mean the entire optical fiber manufacturing apparatus or a part of the optical fiber manufacturing apparatus. Note that the present disclosure is not limited to these examples, and is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims. In the following description, the same reference numerals are given to the same elements in the description of the drawings, and duplicate descriptions are omitted.

[0024] FIG. 1 shows the configuration of an optical fiber manufacturing apparatus 1 as an example. As shown in FIG. 1, the optical fiber manufacturing apparatus 1 is an apparatus for manufacturing an optical fiber element wire F having a glass fiber F11 including a core and a cladding and a coating resin, and includes a wire drawing furnace 11, a forced cooling device 12, an outer diameter measuring device 13, a resin coating device 100, an eccentricity measuring device 16, a UV furnace 17, an outer diameter measuring device 18, a guide roller 20, a capstan 21, and a take-up bobbin 22 in order along the passage of the glass fiber F11 and the optical fiber element wire F.

[0025] In the optical fiber manufacturing apparatus 1, the initial moving direction of the optical fiber element wire F is set in the vertical direction, and in the subsequent stage from the guide roller 20, the moving direction of the optical fiber element wire F is set in the horizontal direction or the diagonal direction. The wire drawing furnace 11 draws a preform (glass base material) 10 mainly composed of quartz glass to form a glass fiber F11 including a core and a cladding. The wire drawing furnace 11 has a heater disposed sandwiching the preform 10 set in the wire drawing furnace 11. The heater may surround the preform 10. The end of the preform 10 is melted by the heating of the heater and drawn into the glass fiber F11. The drawn glass fiber F11 moves downward along the vertical direction.

[0026] The forced cooling device 12 cools the drawn glass fiber F11. The forced cooling device 12 has a sufficient length along the vertical direction in order to sufficiently cool the glass fiber F11. The forced cooling device 12 is provided with, for example, an intake port and an exhaust port (not shown) for cooling, and cools the glass fiber F11 by introducing cooling gas from this intake port.

[0027] The outer diameter measuring device 13 measures the outer diameter of the glass fiber F11 after cooling. For example, the outer diameter measuring device 13 irradiates light on the glass fiber F11 and images the light after passing through the glass fiber F11, thereby measuring the outer diameter of the glass fiber F11.

[0028] The resin coating device 100 coats the glass fiber F11 with resin. The resin coating device 100 holds two types of liquid resins that are cured by ultraviolet rays. In the resin coating device 100, as the glass fiber F11 passes through the held resin, an inner layer resin (first resin 14) and an outer layer resin (second resin 15) are sequentially coated on the surface of the glass fiber F11. Details of the resin coating device 100 will be described later.

[0029] The eccentricity measuring device 16 measures the deviation of the center position of the glass fiber F11 with respect to the center position of the optical fiber element wire F. In other words, the eccentricity measuring device 16 measures the eccentricity of the glass fiber F11 and the inner layer resin and outer layer resin coated on its peripheral surface. For example, the eccentricity measuring device 16 irradiates light on the optical fiber element wire F and images the light after passing through the optical fiber element wire F, thereby measuring the center deviation.

[0030] The UV furnace 17 is a resin curing unit that irradiates ultraviolet rays to cure two types of resins (first resin 14, second resin 15) coated on the surface of the glass fiber F11. As the glass fiber F11 having two types of resins 14 and 15 coated on its surface passes through the UV furnace 17, an optical fiber element wire F having a glass fiber F11 and a two-layer coating layer is formed.

[0031] The outer diameter measuring device 18 measures the outer diameter of the optical fiber element wire F formed by applying resin to the glass fiber F11. The method for measuring the outer diameter is the same as that of the outer diameter measuring device 13 described above.

[0032] The guide roller 20 guides the optical fiber element wire F so that the optical fiber element wire F moves along a predetermined direction. The moving direction of the optical fiber element wire F is changed by the guide roller 20, and it is taken up by the capstan 21 and sent to the take-up bobbin 22. The take-up bobbin 22 winds up the completed optical fiber element wire F.

[0033] Subsequently, the resin coating device 100 will be described in more detail. An example of the resin coating device 100 applies two types of resins 14 and 15 to the glass fiber in order while adjusting the two types of resins 14 and 15 to different temperatures. FIG. 2 is a schematic cross-sectional view showing a longitudinal section of an example of the resin coating device 100. FIG. 3 is a schematic cross-sectional view taken along line III-III of FIG. 2. FIG. 4 is a schematic cross-sectional view taken along line IV-IV of FIG. 2.

[0034] As shown in FIG. 2, an example of the resin coating device 100 is fixed to a stage 101 provided at a predetermined height position in the optical fiber manufacturing device 1. The stage 101 has a plate shape with the vertical direction as the thickness direction. An opening 101a for setting the resin coating device 100 is formed at the center of the stage 101. As an example, the opening 101a may have a circular shape when viewed from above or below.

[0035] The resin coating device 100 includes an inner sleeve 102, an outer sleeve 103, and a die 105. The inner sleeve 102 includes a main body portion 111 and a support piece 113. The main body portion 111 has a cylindrical shape having a central axis 100a along the vertical direction. When viewed from the axial direction, the outer diameter of the main body portion 111 is smaller than the diameter of the opening 101a of the stage 101. A plurality of first through holes 112a and a plurality of second through holes 112b penetrating the side wall are formed in the main body portion 111.

[0036] The first through holes 112a are formed at equal intervals in the circumferential direction of the main body portion 111 and are formed at the same height positions relative to each other. In the illustrated example, four first through holes 112a are formed. The second through holes 112b are formed at equal intervals in the circumferential direction of the main body portion 111 and are formed at the same height positions relative to each other. In the illustrated example, four second through holes 112b are formed.

[0037] The height position at which the second through holes 112b are formed is spaced downward from the height position at which the first through holes 112a are formed. In the middle between the height position at which the first through holes 112a are formed and the height position at which the second through holes 112b are formed, the outer peripheral surface of the main body portion 111 has a recess 111b that is continuous in the circumferential direction.

[0038] The support piece 113 is located at the lower end of the main body portion 111. The support piece 113 includes, for example, a small-diameter portion 113a and a large-diameter portion 113b. The small-diameter portion 113a extends radially outward from the lower end of the main body portion 111 and has a plate shape. The outer shape of the small-diameter portion 113a is circular when viewed from above or below. The outer diameter of the small-diameter portion 113a may be substantially the same as the diameter of the opening 101a of the stage 101.

[0039] The large-diameter portion 113b is located above the small-diameter portion 113a. The large-diameter portion 113b and the small-diameter portion 113a are adjacent to each other. The large-diameter portion 113b and the small-diameter portion 113a may be integrally formed. The large-diameter portion 113b extends radially outward from the outer peripheral surface of the main body portion 111 and has a plate shape. The outer shape of the large-diameter portion 113b may be circular when viewed from above or below. The outer diameter of the large-diameter portion 113b is larger than the outer diameter of the small-diameter portion 113a, that is, the diameter of the opening 101a of the stage 101. By fitting the small-diameter portion 113a into the opening 101a of the stage 101 and placing the large-diameter portion 113b on the upper surface 101b of the stage 101, the resin coating device 100 is fixed to the stage 101.

[0040] The die 105 is disposed in the inner space of the inner sleeve 102. The die 105 includes a first die 120, a second die 130, and a point 140. The first die 120 is cylindrical. The first die 120 shares an axis (central axis 100a) with the main body portion 111 of the inner sleeve 102. The outer diameter of the first die 120 may be the same as the inner diameter of the inner sleeve 102. The die hole 120S of the cylindrical first die 120 forms a part of the fiber passage 105S through which the glass fiber F11 passes. The first die 120 is provided in a range between the height positions of the first through hole 112a and the second through hole 112b.

[0041] The second die 130 is disposed adjacent to the lower side of the first die 120. The second die 130 is cylindrical. The second die 130 shares an axis (central axis 100a) with the main body portion 111 of the inner sleeve 102. The outer diameter of the second die 130 may be the same as the inner diameter of the inner sleeve 102. The end face of the second die 130 on the side of the first die 120 includes an inner portion 131 that is radially inner and an outer portion 132 that is radially outer. The die hole 130S of the cylindrical second die 130 is located at the center of the inner portion 131. The die hole 130S forms a part of the fiber passage 105S through which the glass fiber F11 passes. The height position of the inner portion 131 is lower than the height position of the outer portion 132. Therefore, in a state where the second die 130 is adjacent to the first die 120, the outer portion 132 contacts the first die 120, and a gap 131S is formed between the inner portion 131 and the first die 120. A substantially cylindrical recess is formed on the lower surface of the second die 130. The die hole 130S communicates with this recess.

[0042] Between the inner portion 131 and the outer portion 132 in the second die 130, a groove 133 is formed along the outer periphery of the inner portion 131 and the inner periphery of the outer portion 132. In the second die 130, a plurality of flow paths 136 communicating with the groove 133 are formed. The plurality of flow paths 136 communicate the outer peripheral surface of the second die 130 and the groove 133. The plurality of flow paths 136 are evenly arranged in the circumferential direction when viewed from the axial direction. In the illustrated example, the plurality of flow paths 136 are four flow paths, and in a state where the second die 130 is disposed in the inner sleeve 102, they are respectively connected to the second through holes 112b. The plurality of flow paths 136 extend horizontally along the radial direction of the second die 130.

[0043] The point 140 is disposed adjacent to the upper side of the first die 120. The point 140 has a cylindrical shape. The point 140 shares the axis (central axis 100a) with the main body portion 111 of the inner sleeve 102. The outer diameter of the point 140 may be the same as the inner diameter of the inner sleeve 102. The end face of the point 140 on the side of the first die 120 includes an inner portion 141 that is radially inner and an outer portion 142 that is radially outer. The point hole 140S of the cylindrical point 140 is located at the center of the inner portion 141. The point hole 140S forms a part of the fiber passage 105S through which the glass fiber F11 passes. In the illustrated example, the point hole 140S of the point 140, the die hole 120S of the first die 120, and the die hole 130S of the second die 130 constitute a fiber passage 105S through which the glass fiber F11 passes vertically downward. The fiber passage 105S extends along the vertical direction with the central axis 100a as the center.

[0044] The height position of the inner portion 141 of the point 140 is higher than the height position of the outer portion 142. Therefore, in a state where the point 140 is adjacent to the first die 120, the outer portion 142 contacts the first die 120, and a gap 141S is formed between the inner portion 141 and the first die 120. A substantially conical recess is formed on the upper surface of the point 140. The point hole 140S communicates with this recess.

[0045] Between the inner portion 141 and the outer portion 142 at the point 140, a groove 143 is formed along the outer circumference of the inner portion 141 and the inner circumference of the outer portion 142. At the point 140, a plurality of flow paths 146 communicating with the groove 143 are formed. The plurality of flow paths 146 communicate the outer peripheral surface of the point 140 with the groove 143. The plurality of flow paths 146 are evenly arranged in the circumferential direction when viewed from the axial direction. In the illustrated example, the plurality of flow paths 146 are four flow paths, and in a state where the point 140 is disposed in the inner sleeve 102, they are respectively connected to the first through holes 112a. The plurality of flow paths 146 extend horizontally along the radial direction of the point 140.

[0046] The outer sleeve 103 is fixed to the outer peripheral surface of the inner sleeve 102. The outer sleeve 103 includes a first annular body 150 and a second annular body 170. The first annular body 150 has an annular shape arranged around the fiber passage 105S (central axis 100a). In one example, the first annular body 150 has a cylindrical shape with an inner diameter the same as the outer diameter of the inner sleeve 102. The first annular body 150 includes a first flow path 151 and a first temperature adjuster 160.

[0047] The first flow path 151 allows the first resin 14 to flow toward the fiber passage 105S. The first flow path 151 has a supply port 152 to which the first resin 14 is supplied and a discharge port 153 connected to the first through hole 112a of the inner sleeve 102. The first resin 14 supplied from the supply port 152 is discharged from the discharge port 153 and thus supplied to the first through hole 112a. The first resin 14 supplied to the first through hole 112a reaches the fiber passage 105S through the flow path 146, the groove 143, and the gap 141S of the point 140.

[0048] The first flow path 151 has a branch path that horizontally branches the first resin 14 moving in the horizontal direction. The first flow path 151 extends horizontally inside the first annular body 150. The first flow path 151 branches into a plurality of flow paths by the branch path so as to correspond to the number of the first through holes 112a formed in the inner sleeve 102. Note that the first flow path 151 does not necessarily exactly follow the horizontal direction, and it may substantially follow the horizontal direction. For example, the first flow path 151 may be formed at an angle of about -3° to 3° with respect to the horizontal.

[0049] The first flow path 151 in the illustrated example includes an upstream branch path 154 (the first branch path on the upstream side) and a downstream branch path 155 (the first branch path on the downstream side). The upstream branch path 154 branches the flow path 151a continuing from the supply port 152 into a plurality of paths. The downstream branch path 155 further branches each of the plurality of flow paths 151b branched by the upstream branch path 154 into a plurality of paths. In the illustrated example, both the upstream branch path 154 and the downstream branch path 155 have one inlet and two outlets. That is, the upstream branch path 154 and the downstream branch path 155 branch the flow path into two paths.

[0050] As shown in FIG. 3, the flow path 151a connected to the supply port 152 branches into two flow paths 151b by the upstream branch path 154. The two branched flow paths 151b extend in opposite directions along the circumferential direction. The lengths of the two flow paths 151b are equal to each other. The branched flow paths 151b are respectively connected to the downstream branch paths 155. The downstream branch paths 155 face each other with the fiber passage 105S interposed therebetween. The downstream branch path 155 branches the flow path 151b along the circumferential direction. That is, the downstream branch path 155 extends radially inward from the end of the flow path 151b, branches at that position, and is connected to two flow paths 151c extending in opposite directions along the circumferential direction. The lengths of the two flow paths 151c are equal to each other. The four flow paths 151c branched by the pair of downstream branch paths 155 facing each other extend in the circumferential direction such that the terminal positions are evenly arranged in the circumferential direction. The four flow paths 151c are respectively connected to the four first through holes 112a via the discharge ports 153.

[0051] The cross-sectional area of the inlet of the branch is equal to the sum of the cross-sectional areas of each of the plurality of outlets. That is, in the illustrated example, the cross-sectional area of each of the two flow paths 151b (outlets) connected to the upstream branch path 154 may be half of the cross-sectional area of the flow path 151a (inlet) connected to the upstream branch path 154. Similarly, the cross-sectional area of each of the two flow paths 151c (outlets) connected to the downstream branch path 155 may be half of the cross-sectional area of the flow path 151b (inlet) connected to the downstream branch path 155. Note that the cross-sectional area of the inlet of the branch only needs to be substantially equal to the sum of the cross-sectional areas of each of the plurality of outlets, and for example, an error of 10% or less is allowed. Similarly, the cross-sectional areas of each of the plurality of outlets only need to be substantially equal, and for example, an error of 10% or less is allowed.

[0052] The first temperature regulator 160 is arranged along the first flow path 151 and adjusts the temperature of the first resin 14 flowing through the first flow path 151. In one example, the heat source of the first temperature regulator 160 may be a heater 162 arranged along the first flow path 151. The heater 162 may include, for example, a resistor that generates heat by electric power supplied from the outside. The heater 162 is horizontally arranged at a height position shifted in either the vertical direction with respect to the first flow path 151. In the illustrated example, the heater 162 is arranged above the first flow path 151. Also, for example, when viewed from above or below, the ends 162a, 162b of the heater 162 are located at positions on the opposite side of the supply port 152 with respect to the fiber passage 105S as the center. The heater 162 extends along the circumferential direction from the end 162a to the end 162b. In the radial direction, the heater 162 extends so as to include from the inner edge of the flow path 151c to the outer edge of the flow path 151b. Also, in the circumferential direction, the heater 162 extends at least in the range where the flow paths 151b, 151c are formed. Thereby, when viewed from above or below, the positions of the flow paths 151b and 151c overlap the position of the heater 162.

[0053] The second annular body 170 has an annular shape arranged around the fiber passage 105S. In one example, the second annular body 170 has a cylindrical shape with an inner diameter the same as the outer diameter of the inner sleeve 102. The second annular body 170 includes a second flow path 171 and a second temperature regulator 180.

[0054] The second flow path 171 allows the second resin 15 to flow toward the fiber passage 105S. The second flow path 171 has a supply port 172 to which the second resin 15 is supplied and a discharge port 173 connected to the second through hole 112b of the inner sleeve 102. The second resin 15 supplied from the supply port 172 is discharged from the discharge port 173 and thus supplied to the second through hole 112b. The second resin 15 supplied to the second through hole 112b reaches the fiber passage 105S via the flow path 136, the groove 133, and the gap 131S of the second die 130.

[0055] The second flow path 171 has a branch path that branches the second resin 15 moving in the horizontal direction in the horizontal direction. In one example, the second flow path 171 extends horizontally inside the second annular body 170. The second flow path 171 branches into a plurality of flow paths by the branch path so as to correspond to the number of the second through holes 112b formed in the inner sleeve 102. Note that the second flow path 171 does not have to be exactly along the horizontal direction, and it may be substantially along the horizontal direction. For example, the second flow path 171 may be formed at an angle of about -3° to 3° with respect to the horizontal.

[0056] The second flow path 171 in the illustrated example includes an upstream branch path 174 (the second branch path on the upstream side) and a downstream branch path 175 (the second branch path on the downstream side). The upstream branch path 174 branches the flow path 171a continuing from the supply port 172 into a plurality of paths. The downstream branch path 175 further branches each of the plurality of flow paths 171b branched by the upstream branch path 174 into a plurality of paths. In the illustrated example, both the upstream branch path 174 and the downstream branch path 175 have one inlet and two outlets. That is, the upstream branch path 174 and the downstream branch path 175 branch the flow path into two paths.

[0057] As shown in FIG. 4, the flow path 171a connected to the supply port 172 branches into two flow paths 171b by the upstream branch path 174. The branched flow paths 171b extend in opposite directions along the circumferential direction respectively. The two branched flow paths 171b are respectively connected to the downstream branch paths 175. The lengths of the two flow paths 171b are equal to each other. The downstream branch paths 175 face each other across the fiber passage 105S. The downstream branch path 175 branches the flow path 171b along the circumferential direction. That is, the downstream branch path 175 extends radially inward from the end of the flow path 171b, branches at that position, and is connected to two flow paths 171c that extend in opposite directions along the circumferential direction. The lengths of the two flow paths 171c are equal to each other. The four flow paths 171c branched by the pair of downstream branch paths 175 facing each other extend in the circumferential direction so that the terminal positions are evenly arranged in the circumferential direction. The four flow paths 171c are respectively connected to the four second through holes 112b via the discharge ports 173.

[0058] The cross-sectional area of the inlet of the branch path is equal to the sum of the cross-sectional areas of each of the plurality of outlets. That is, in the illustrated example, it may be half of the cross-sectional area of the flow path 171a (inlet) connected to the upstream branch path 174. Similarly, the cross-sectional area of each of the two flow paths 171c (outlets) connected to the downstream branch path 175 may be half of the cross-sectional area of the flow path 171b (inlet) connected to the downstream branch path 175.

[0059] The second temperature regulator 180 is arranged along the second flow path 171 and adjusts the temperature of the second resin flowing through the second flow path 171. In one example, the heat source of the second temperature regulator 180 may be a flow path (hereinafter referred to as a temperature-controlled water flow path) through which the temperature-controlled fluid flows. The fluid may be temperature-controlled water (hereinafter referred to as temperature-controlled water). The second temperature regulator 180 is arranged along the second flow path 171.

[0060] The temperature control water flow path 182 (the third flow path) is horizontally arranged at a height position shifted either upward or downward with respect to the second flow path 171. In the illustrated example, the temperature control water flow path 182 is arranged below the second flow path 171. Therefore, the first flow path 151 and the second flow path 171 are located between the first temperature regulator 160 and the second temperature regulator 180 in the vertical direction.

[0061] The end portions 182a and 182b of the temperature control water flow path 182 are located at positions on the opposite side of the supply port 172 with respect to the fiber passage 105S as the center. The temperature control water flow path 182 extends along the circumferential direction from the end portion 182a to the end portion 182b. The temperature control water flowing through the temperature control water flow path 182 is supplied, for example, from the end portion 182a and discharged from the end portion 182b. Connection ends 181 for supplying or discharging the temperature control water are separately provided at the end portions 182a and 182b. The temperature control water discharged from the end portion 182b may be temperature-adjusted again and supplied to the end portion 182a. In the radial direction, the temperature control water flow path 182 extends so as to include from the inner edge of the flow path 171c to the outer edge of the flow path 171b. Also, in the circumferential direction, the temperature control water flow path 182 extends at least in the range where the flow paths 171b and 171c are formed. Thereby, when viewed from above or below, the positions of the flow paths 171b and 171c overlap the position of the temperature control water flow path 182.

[0062] In the vertical direction, a heat insulating layer 191 is formed between the first annular body 150 and the second annular body 170. In the illustrated example, the first annular body 150 and the second annular body 170 are separated from each other in the vertical direction. That is, an air layer functioning as the heat insulating layer 191 is formed between the first annular body 150 and the second annular body 170. In one example, the air layer is formed along the position of the recess 111b formed on the outer peripheral surface of the inner sleeve 102.

[0063] Next, a method for manufacturing an optical fiber in the optical fiber manufacturing apparatus 1 will be described. In the above-described optical fiber manufacturing apparatus 1, first, a preform 10 serving as a base material is set in the drawing furnace 11. Then, the preform 10 is melted by a heater. The melted preform 10 is drawn, and a glass fiber F11 is formed. The glass fiber F11 moves downward along the vertical direction and passes through the forced cooling device 12. In the forced cooling device 12, the drawn glass fiber F11 is cooled.

[0064] The cooled glass fiber F11 passes through the outer diameter measuring device 13, and the outer diameter of the glass fiber F11 is measured. The glass fiber F11 with the measured outer diameter moves downward along the vertical direction and passes through the resin coating device 100.

[0065] In the resin coating device 100, a first resin 14 is supplied to the first flow path 151 at a predetermined flow rate, and a second resin 15 is supplied to the second flow path 171 at a predetermined flow rate. The first resin 14 supplied to the first flow path 151 is adjusted to a predetermined first temperature by the first temperature adjuster 160, and the second resin 15 supplied to the second flow path 171 is adjusted to a predetermined second temperature by the second temperature adjuster 180. The temperature adjusted by the first temperature adjuster 160 and the temperature adjusted by the second temperature adjuster 180 are different from each other.

[0066] In the resin coating apparatus 100, the viscosity of the resin is adjusted to fall within a predetermined range by adjusting the temperature of the resin. Generally, the viscosity (Pa·s) of the resin depends on the temperature, being lower as the temperature is higher and higher as the temperature is lower. In the above optical fiber manufacturing apparatus 1, by adjusting the viscosity of the resin to a predetermined range, the resin can be appropriately coated on the peripheral surface of the glass fiber F11. In one example, the first resin 14 needs to be flexible in order to absorb external distortion by contacting the glass fiber F11 and tends to have a high viscosity. Also, the second resin 15 needs to have hardness and toughness in order to withstand external stress and tends to have a low viscosity. That is, under the same temperature conditions, the viscosity of the first resin 14 is higher than the viscosity of the second resin 15. In this case, in order to adjust the viscosities of the first resin 14 and the second resin 15 to a range suitable for coating, it is necessary to adjust the temperature of the first resin 14 to a temperature higher than the temperature of the second resin 15. Therefore, in one example of the resin coating apparatus 100, the first temperature is set higher than the second temperature.

[0067] In one example of the resin coating apparatus 100, the viscosities of the first resin 14 and the second resin 15 when being coated on the glass fiber F11 are adjusted to about 0.8 Pa·s to 2.0 Pa·s. As an example, when the first temperature adjusted by the first temperature adjuster 160 is about 35°C to 70°C and the second temperature adjusted by the second temperature adjuster 180 is 30°C to 45°C, the first resin 14 and the second resin 15 can satisfy the above-mentioned viscosities. In this case, the viscosity ratio (viscosity of the second resin / viscosity of the first resin) of the first resin 14 and the second resin 15 may be, for example, about 0.5 to 0.9.

[0068] The temperature-adjusted first resin 14 flows into the fiber passage 105S through the first flow path 151, the first through-hole 112a, the flow path 146, the groove 143, and the gap 141S. The first resin 14 flows into the groove 143 and the gap 141S that surround the fiber passage 105S over the entire circumferential direction from the plurality of flow paths 146 arranged evenly in the circumferential direction. Thereby, the flow of the first resin 14 in the vicinity of the fiber passage 105S becomes uniform in the circumferential direction. Similarly, the second resin 15 flows into the fiber passage 105S through the second flow path 171, the second through-hole 112b, the flow path 136, the groove 133, and the gap 131S. The second resin flows into the groove 133 and the gap 131S that surround the fiber passage 105S over the entire circumferential direction from the flow paths 136 arranged evenly in the circumferential direction. Thereby, the flow of the second resin 15 in the vicinity of the fiber passage 105S becomes uniform in the circumferential direction.

[0069] When the glass fiber F11 moving vertically downward passes through the fiber passage 105S, first, the first resin 14 is applied to the circumferential surface of the glass fiber F11. Then, as the glass fiber F11 moves downward, the second resin 15 is further applied onto the first resin 14 applied to the glass fiber F11.

[0070] Subsequently, the displacement of the central position of the glass fiber F11 with respect to the central position of the optical fiber element wire F is measured by the eccentricity measuring device 16. Then, the glass fiber F11 coated with the resins 14 and 15 moves downward along the vertical direction and passes through the UV furnace 17. When the glass fiber F11 passes through the UV furnace 17, the resins 14 and 15 are irradiated with ultraviolet rays, and the optical fiber element wire F is formed. The optical fiber element wire F moves along a predetermined direction via the guide roller 20, is taken up by the capstan 21, and is sent to the winding bobbin 22.

[0071] In the resin coating device 100 of the optical fiber manufacturing device 1 described above, in the first flow path 151 and the second flow path 171, upstream branch paths 154 and downstream branch paths 155 (first branch paths), and upstream branch paths 174 and downstream branch paths 175 (second branch paths) for branching the resin in the horizontal direction are respectively formed. Therefore, flow paths leading to the fiber passage 105S can be formed from a plurality of positions in the circumferential direction. Accordingly, the flow of the resin applied to the glass fiber F11 can be uniformly adjusted in the circumferential direction of the glass fiber F11. Further, since the flow paths including each branch path branch only in the horizontal direction, the size of the resin coating device 100 in the vertical direction can be reduced. Thereby, an increase in the overall height of the optical fiber manufacturing device 1 is suppressed.

[0072] In one example, the first flow path 151 and the first temperature adjuster 160 are formed in a first annular body 150 having an annular shape arranged around the fiber passage 105S. Further, the second flow path 171 and the second temperature adjuster 180 are formed in a second annular body 170 having an annular shape arranged below the first annular body 150 around the fiber passage 105S. With this configuration, it is easy to arrange the flow paths 151, 171 and the temperature adjusters 160, 180 evenly around the fiber passage 105S.

[0073] In one example, in the vertical direction, a heat insulating layer 191 is formed between the first annular body 150 and the second annular body 170. With this configuration, it is suppressed that the first temperature adjuster 160 formed in the first annular body 150 affects the second annular body 170. Further, it is suppressed that the second temperature adjuster 180 formed in the second annular body 170 affects the first annular body 150.

[0074] Further, the first flow path 151 and the second flow path 171 are located between the first temperature regulator 160 and the second temperature regulator 180 in the vertical direction. The temperature of the first flow path 151 is adjusted by the first temperature regulator 160, and the temperature of the second flow path 171 is adjusted by the second temperature regulator 180. In this configuration, it is possible to suppress the first temperature regulator 160 formed in the first annular body 150 from affecting the second annular body 170. Further, it is possible to suppress the second temperature regulator 180 formed in the second annular body 170 from affecting the first annular body 150.

[0075] In one example, the first temperature regulator 160 uses a heater 162 arranged along the first flow path 151 as a heat source. Further, the second temperature regulator 180 is arranged along the second flow path 171 and uses a temperature-controlled water flow path 182 through which the temperature-adjusted fluid flows as a heat source. In this configuration, for example, the first resin 14 flowing through the first flow path 151 can be easily adjusted to a higher temperature than the second resin 15.

[0076] The upstream branch path 154 has a flow path 151a as an inlet and two flow paths 151b as outlets. The flow path cross-sectional area of one flow path 151b is half of the flow path cross-sectional area of the flow path 151a. Further, the downstream branch path 155 has a flow path 151b as an inlet and two flow paths 151c as outlets. The flow path cross-sectional area of one flow path 151c is half of the flow path cross-sectional area of the flow path 151b. Further, the cross-sectional area of the inlet of each branch path is equal to the sum of the cross-sectional areas of the outlets. With this configuration, the first resin 14 can be evenly branched by each branch path. Note that the above operation is the same for the upstream branch path 174 and the downstream branch path 175.

[0077] The first flow path 151 includes four outlets, the flow paths 151c, branched by the upstream branch path 154 and the downstream branch path 155. The four flow paths 151c are evenly arranged in the circumferential direction around the fiber passage 105S. With this configuration, the flow of the first resin 14 in the vicinity of the fiber passage 105S is likely to be uniform in the circumferential direction.

[0078] The upstream branch path 174 has the flow path 171a as an inlet and has two flow paths 171b as outlets. The flow path cross-sectional area of one flow path 171b is half of the flow path cross-sectional area of the flow path 171a. Further, the downstream branch path 175 has the flow path 171b as an inlet and has two flow paths 171c as outlets. The flow path cross-sectional area of one flow path 171c is half of the flow path cross-sectional area of the flow path 171b. Also, the cross-sectional area of the inlet of each branch path is equal to the sum of the cross-sectional areas of the respective outlets. With this configuration, the second resin 15 can be evenly branched by each branch path.

[0079] The second flow path 171 includes the flow paths 171c which are the four outlets branched by the upstream branch path 174 and the downstream branch path 175. The four flow paths 171c are evenly arranged in the circumferential direction around the fiber passage 105S. With this configuration, the flow of the second resin 15 in the vicinity of the fiber passage 105S is likely to be uniform in the circumferential direction.

[0080] The present disclosure is not limited to the above-described embodiments and can be appropriately changed without departing from the gist described in the claims.

[0081] For example, although an example in which the heat insulation layer 191 is formed by air is shown, the heat insulation layer 191 may be formed by a heat insulating material or the like.

[0082] Also, although an example in which the heat source of the first temperature regulator 160 is the heater 162 arranged along the first flow path 151 is shown, the heat source of the first temperature regulator 160 may be a flow path arranged along the first flow path 151 instead of the heater 162. The flow path may have the same configuration as the temperature control water flow path 182, and hot water managed at a temperature different from the hot water supplied to the temperature control water flow path 182 may be supplied. Further, the heat source of the second temperature regulator 180 may be a heater similar to the heater 162 instead of the temperature control water flow path 182.

[0083] In the upstream side branch paths 154 and 174 and the downstream side branch paths 155 and 175, an example in which the flow path is branched into two is shown, but the configuration of each branch path is not limited to this. For example, the branch path may have three or more outlets for one inlet. Also, the flow paths 151 and 171 may include only the upstream side flow path. Even in this case, the branch path may have three or more outlets for one inlet.

Explanation of Signs

[0084] 1…Optical fiber manufacturing apparatus 10…Preform (glass base material) 11…Wire drawing furnace 12…Forced cooling device 13…Outer diameter measuring device 14…Resin 15…Resin 16…Eccentricity measuring device 17…UV furnace 18…Outer diameter measuring device 20…Guide roller 21…Capstan 22…Take-up bobbin 100…Resin coating device 100a…Central axis 101…Stage 101a…Opening 101b…Upper surface 102…Inner sleeve 103…Outer sleeve 105…Die 105S…Fiber passage 111…Body part 111b…Recess 112a…First through hole 112b…Second through hole 113…Support piece 113a…Small diameter part 113b…Large diameter part 120…First die 120S…Die hole 130…Second die 130S…Die hole 131…Inner part 131S…Gap 132…Outer part 133…Groove 136…Flow path 140…Point 140S…Point hole 141…Inner part 141S…Gap 142…Outer part 143…Groove 146…Flow path 150…First annular body 151…First flow path 151a…Flow path 151b…Flow path 151c…Flow path 152…Supply port 153…Discharge port 154…Upstream side branch path 155…Downstream side branch path 160…First temperature regulator 162…Heater 162a…End part 162b…End part 170…Second annular body 171…Second flow path 171a…Flow path 171b…Flow path 171c…Flow path 172…Supply port 173…Discharge port 174…Upstream side branch path 175…Downstream side branch path 180…Second temperature regulator 182…Temperature control water flow path (third flow path) 182a…End part 182b…End part 191…Heat insulation layer F…Optical fiber element wire F11…Glass fiber

Claims

1. a fiber passage through which glass fibers pass vertically downward; a flow path for flowing a first resin toward the fiber passage, the first flow path having a first branch path that branches the first resin moving in the horizontal direction in the horizontal direction; a first temperature adjuster disposed along the first flow path for adjusting the temperature of the first flow path; a flow path for flowing a second resin toward the fiber passage, the second flow path having a second branch path that branches the second resin moving in the horizontal direction in the horizontal direction, and the second flow path being located below the first flow path; a second temperature adjuster disposed along the second flow path for adjusting the temperature of the second flow path, and comprising: The first flow path and the second flow path are each branched into two and then further branched into four flow paths from positions advanced 90° in the circumferential direction around the fiber passage, and the four flow paths are spaced 90° apart from each other in the circumferential direction. Coating device.

2. The first flow path and the first temperature adjuster form a first annular body having an annular shape disposed around the fiber passage; The second flow path and the second temperature adjuster form a second annular body having an annular shape disposed below the first annular body around the fiber passage. The coating device according to claim 1.

3. The first annular body and the second annular body are separated in the vertical direction, and a heat insulating layer made of an air layer is formed between the first annular body and the second annular body. The coating device according to claim 2.

4. The first flow path and the second flow path are located between the first temperature adjuster and the second temperature adjuster in the vertical direction, the temperature of the first flow path is adjusted by the first temperature adjuster, and the temperature of the second flow path is adjusted by the second temperature adjuster. The coating device according to any one of claims 1 to 3.

5. The heat source in the first temperature adjuster is a heater disposed along the first flow path; The heat source in the second temperature adjuster is a third flow path disposed along the second flow path through which a temperature-adjusted fluid flows. The coating device according to any one of claims 1 to 4.

6. The first branch path has one inlet and two outlets, and the cross-sectional area of each of the two outlets is half of the cross-sectional area of the one inlet. The coating device according to any one of claims 1 to 5.

7. The first branch path has one inlet and a plurality of outlets, and the cross-sectional area of the one inlet is equal to the sum of the cross-sectional areas of each of the plurality of outlets. The coating apparatus according to any one of claims 1 to 5.

8. The first flow path includes four outlets branched by the first branch path. The four outlets are evenly arranged in the circumferential direction around the fiber passage. The coating apparatus according to any one of claims 1 to 5.

9. The second branch path has one inlet and two outlets, and the cross-sectional area of each of the two outlets is half of the cross-sectional area of the one inlet. The coating apparatus according to any one of claims 1 to 8.

10. The second branch path has one inlet and a plurality of outlets, and the cross-sectional area of the one inlet is equal to the sum of the cross-sectional areas of each of the plurality of outlets. The coating apparatus according to any one of claims 1 to 8.

11. The second flow path includes four outlets branched by the second branch path. The four outlets are evenly arranged in the circumferential direction around the fiber passage. The coating apparatus according to any one of claims 1 to 8.

12. A method of coating a glass fiber with a resin, comprising: a step of passing the glass fiber vertically downward through a fiber passage; a step of flowing a first resin through a first flow path that branches in the horizontal direction and adjusting the temperature by a first temperature adjuster to adjust the temperature of the first resin to a first temperature; a step of flowing a second resin through a second flow path that is located below the first flow path and branches in the horizontal direction and adjusting the temperature by a second temperature adjuster to adjust the temperature of the second resin to a second temperature; a step of coating the glass fiber moving in the fiber passage with the first resin that has flowed through the first flow path; a step of coating the glass fiber that has moved in the fiber passage and on which the first resin has been coated with the second resin that has flowed through the second flow path. The first flow path and the second flow path each further branch into four branches after branching into two branches and then advancing 90° in the circumferential direction around the fiber passage, and the four-branched flow paths are spaced 90° apart from each other in the circumferential direction. Coating method.

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