Bare optical fiber coating device and bare optical fiber coating method
A bare optical fiber coating device includes: a nipple having a nipple hole through which a bare optical fiber is inserted vertically from above; an intermediate die that has an intermediate die hole through which the bare optical fiber passing through the nipple hole is inserted and that is disposed vertically below the nipple; a first coating die that has a first coating die hole through which the bare optical fiber passing through the intermediate die hole is inserted and that is provided vertically below the intermediate die; and a first resin circulation chamber that is formed by the nipple and the intermediate die, is formed between the nipple hole and the intermediate die hole in an annular shape surrounding the bare optical fiber passing through the nipple hole, and is configured to circulate liquid resin.
1. A bare optical fiber coating device, comprising:
a nipple having a nipple hole through which a bare optical fiber is inserted vertically from above;
an intermediate die that has an intermediate die hole through which the bare optical fiber after passing through the nipple hole is inserted and that is disposed vertically below the nipple;
a first coating die that has a first coating die hole through which the bare optical fiber after passing through the intermediate die hole is inserted and that is provided vertically below the intermediate die;
a first resin circulation chamber that comprises the nipple and the intermediate die, the first resin circulation chamber being disposed between the nipple hole and the intermediate die hole in an annular shape surrounding the bare optical fiber after passing through the nipple hole, and being configured to circulate liquid resin;
a second resin circulation chamber that comprises the intermediate die and the first coating die, the second resin circulation chamber being disposed between the intermediate die hole and the first coating die hole in an annular shape surrounding the bare optical fiber passing through the intermediate die hole, and being configured to circulate liquid resin;
a first resin supply passage configured to supply liquid resin to the first resin circulation chamber;
a second resin supply passage configured to supply liquid resin to the second resin circulation chamber;
at least one resin supply source which supplies a resin to one or both of the first resin supply passage and the second resin supply passage,
a first resin reservoir chamber provided on an inlet side of the first resin supply passage and being divided from the first resin circulation chamber by a first inner intermediate wall; and
a second resin reservoir chamber provided on an inlet side of the second resin supply passage and being divided from the second resin circulation chamber by a second inner intermediate wall;
wherein a first resin circulation chamber side of the first inner intermediate wall is parallel to a traveling direction of the bare optical fiber and a second resin circulation chamber side of the second inner intermediate wall is parallel to the traveling direction of the bare optical fiber, and
the first and second resin supply passages are provided separately and independently from each other, and a first resin path from the first resin supply passage to the intermediate die hole through the first resin circulation chamber and a second resin path from the second resin supply passage to the first coating die hole through the second resin circulation chamber are independent of each other.
2. The bare optical fiber coating device according to claim 1 , further comprising:
a second coating die that has a second coating die hole through which the bare optical fiber after passing through the first coating die hole is inserted and that is provided vertically below the first coating die;
a third resin circulation chamber that comprises the first coating die and the second coating die, is formed between the first coating die hole and the second coating die hole in an annular shape surrounding the bare optical fiber after passing through the first coating die hole, and is configured to circulate the liquid resin;
a third resin supply passage configured to supply the liquid resin to the third resin circulation chamber,
a third resin reservoir chamber provided on an inlet side of the third resin supply passage and divided from the third resin circulation chamber by a third inner intermediate wall;
wherein a third resin circulation chamber side of the third inner intermediate wall is parallel to the traveling direction of the bare optical fiber and,
the first resin supply passage, the second resin supply passage, and the third resin supply passage are provided separately and independently from each other, and the first resin path, the second resin path, and a third resin path from the third resin supply passage to the second coating die hole through the third resin circulation chamber are formed independently of each other.
3. The bare optical fiber coating device according to claim 1 , wherein
the first resin reservoir chamber has an annular shape with a center on a traveling position of the bare optical fiber,
the second resin reservoir chamber has an annular shape with the center on the traveling position of the bare optical fiber,
wherein a resin inlet through which liquid resin is introduced from an outside is disposed in each of the first and second resin reservoir chambers, and the first and second resin supply passages are continuous in an annular shape with a center on the traveling position of the bare optical fiber.
4. The bare optical fiber coating device according to claim 2 , wherein
the first resin reservoir chamber has an annular shape with a center on a traveling position of the bare optical fiber;
the second resin reservoir chamber has an annular shape with the center on the traveling position of the bare optical fiber; and
a third resin reservoir chamber has an annular shape with the center on the traveling position of the bare optical fiber,
wherein a resin inlet through which the liquid resin is introduced from an outside is formed in each of the first resin reservoir chamber, the second resin reservoir chamber, and the third resin reservoir chamber, and the first resin supply passage, the second resin supply passage, and the third resin supply passage are continuous in an annular shape with a center on the traveling position of the bare optical fiber.
5. The bare optical fiber coating device according to claim 1 ,
wherein a length of the second resin circulation chamber along the traveling direction of the bare optical fiber is greater than a length of the first resin circulation chamber along the traveling direction of the bare optical fiber.
6. The bare optical fiber coating device according to claim 5 ,
wherein the length of the first resin circulation chamber along the traveling direction of the bare optical fiber is 1.5 mm to 10 mm, and the length of the second resin circulation chamber along the traveling direction of the bare optical fiber is 20 mm to 40 mm.
7. The bare optical fiber coating device according to claim 2 ,
wherein a length of the first resin circulation chamber along the traveling direction of the bare optical fiber is 1.5 mm to 10 mm, a length of the second resin circulation chamber along the traveling direction of the bare optical fiber is 20 mm to 40 mm, and a length of the third resin circulation chamber along the traveling direction of the bare optical fiber is 1.0 mm to 2.0 mm.
8. The bare optical fiber coating device according to claim 1 ,
wherein, in a plane perpendicular to the traveling direction of the bare optical fiber, an inner diameter of the first resin circulation chamber is Φ5 mm±Φ2 mm, and an inner diameter of the second resin circulation chamber is Φ3 mm±Φ1 mm.
9. The bare optical fiber coating device according to claim 2 ,
wherein, in a plane perpendicular to the traveling direction of the bare optical fiber, an inner diameter of the first resin circulation chamber is Φ 5 mm±Φ 2 mm, an inner diameter of the second resin circulation chamber is Φ3 mm±Φ1 mm, and an inner diameter of the third resin circulation chamber is Φ15 mm±Φ5 mm.
10. The bare optical fiber coating device according to claim 1 ,
wherein, a hole diameter of an outlet in the nipple hole is Φdn, a hole diameter of an outlet in the intermediate die hole is Φdm, and a hole diameter of an outlet in the first coating die hole is Φdc, the hole diameters satisfy conditions of Φdn>Φdc>Φdm.
11. The bare optical fiber coating device according to claim 2 ,
wherein, a hole diameter of an outlet in the nipple hole is Φdn, a hole diameter of an outlet in the intermediate die hole is Φdm, a hole diameter of an outlet in the first coating die hole is Φdp, and a hole diameter of an outlet in the second coating die hole is Φds, the hole diameters satisfy conditions of Φdn>Φdp>Φdm and Φds>Φdp>Φdm.
12. The bare optical fiber coating device according to claim 1 ,
wherein, in each of the first and second resin supply passages, an inner size in a direction along the traveling direction of the bare optical fiber is 0.5 mm±0.2 mm.
13. The bare optical fiber coating device according to claim 2 ,
wherein, in each of the first resin supply passage, the second resin supply passage, and the third resin supply passage, an inner size in a direction along the traveling direction of the bare optical fiber is 0.5 mm±0.2 mm.
14. The bare optical fiber coating device according to claim 1 ,
wherein a resin outlet to each of the resin circulation chambers in each of the resin supply passages is located above each of the resin circulation chambers.
15. The bare optical fiber coating device according to claim 1 ,
wherein pressure of liquid resin supplied to the first resin circulation chamber is equal to or higher than pressure of liquid resin supplied to the second resin circulation chamber.
16. The bare optical fiber coating device according to claim 15 ,
wherein, the pressure of liquid resin supplied to the first resin circulation chamber is P 1 and the pressure of liquid resin supplied to the second resin circulation chamber is P 2 , a resin pressure difference [P 1 -P 2 ] is within a range of 0.01 MPa±0.01 MPa.
17. The bare optical fiber coating device according to claim 1 ,
wherein a hole diameter of an outlet in the intermediate die hole is within a range of 0.17 mm to 0.23 mm.
18. The bare optical fiber coating device according to claim 1 ,
wherein a hole diameter of an outlet in the intermediate die hole is within a range of 0.25 mm to 0.27 mm.
19. The bare optical fiber coating device according to claim 2 ,
wherein a hole diameter of an outlet in the intermediate die hole is within a range of 0.17 mm to 0.23 mm.
20. A bare optical fiber coating method for performing resin coating on a bare optical fiber, the method comprising:
providing the bare optical fiber coating device according to claim 1 ,
causing a circulation flow of liquid resin in each of the first and second resin circulation chambers when performing resin coating on the bare optical fiber by:
making the bare optical fiber pass through the nipple hole, the first resin circulation chamber, the intermediate die hole, the second resin circulation chamber, and the first coating die hole in this order from a side above the nipple;
supplying liquid resin to the first resin circulation chamber from the first resin supply passage so that liquid resin in the first resin circulation chamber flows into the intermediate die hole; and
supplying liquid resin to the second resin circulation chamber from the second resin supply passage so that liquid resin in the second resin circulation chamber flows into the first coating die hole.
21. The bare optical fiber coating method according to claim 20 , further comprising
causing only a single circulation flow in each of the first and second resin circulation chambers.
22. A bare optical fiber coating method for performing resin coating on a bare optical fiber, the method comprising:
providing the bare optical fiber coating device according to claim 2 ,
causing a circulation flow of liquid resin in each of the first resin circulation chamber, the second resin circulation chamber, and the third resin circulation chamber when performing resin coating on the bare optical fiber by:
making the bare optical fiber pass through the nipple hole, the first resin circulation chamber, the intermediate die hole, the second resin circulation chamber, the first coating die hole, the third resin circulation chamber, and the second coating die hole in this order from a side above the nipple;
supplying liquid resin to the first resin circulation chamber from the first resin supply passage so that the liquid resin in the first resin circulation chamber flows into the intermediate die hole;
supplying liquid resin to the second resin circulation chamber from the second resin supply passage so that liquid resin in the second resin circulation chamber flows into the first coating die hole; and
supplying liquid resin to the third resin circulation chamber from the third resin supply passage so that liquid resin in the third resin circulation chamber flows into the second coating die hole.
23. The bare optical fiber coating method according to claim 22 , further comprising
causing only a single circulation flow in each of the first resin circulation chamber, the second resin circulation chamber, and the third resin circulation chambers.
24. The bare optical fiber coating device according to claim 2 ,
wherein a resin outlet to each of the resin circulation chambers in each of the resin supply passages is located above each of the resin circulation chambers.
25. The bare optical fiber coating device according to claim 2 ,
wherein pressure of liquid resin supplied to the first resin circulation chamber is equal to or higher than pressure of liquid resin supplied to the second resin circulation chamber.
26. The bare optical fiber coating device according to claim 25 ,
wherein, the pressure of liquid resin supplied to the first resin circulation chamber is P 1 and the pressure of liquid resin supplied to the second resin circulation chamber is P 2 , a resin pressure difference [P 1 -P 2 ] is within a range of 0.01 MPa±0.01 MPa.
27. The bare optical fiber coating method according to claim 22 ,
wherein liquid resin supplied to the third resin circulation chamber is different from liquid resin supplied to the first and second resin circulation chambers.
28. The bare optical fiber coating method according to claim 22 ,
wherein liquid resin supplied to the third resin circulation chamber is the same liquid resin supplied to the first and second resin circulation chambers.