JP2939607B2 - Optical fiber coating head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber coating head for coating an optical fiber with a resin when manufacturing an optical fiber.

[0002]

2. Description of the Related Art A coating head as shown in FIG. 3 is conventionally used as an apparatus for coating an optical fiber with a resin at the time of manufacturing an optical fiber. The coating head includes a cylindrical holder 30 provided with a resin supply path 42,
The distal end portion 31 is formed in a hollow body having a substantially conical shape and an optical fiber wire guiding nozzle 32 is provided at the distal end thereof. The holder 30 is positioned so that the distal end portion 31 is located in the rear end opening of the holder 30. It has a nipple 33 attached to the rear end, a joining surface 35 slidably joined to the tip end surface 34 of the holder 30 on one end surface, and a resin guiding wall 36 formed of a substantially conical concave portion. A die 39 provided with an optical fiber core take-out nozzle 38 for forming a resin-coated outer shape of the optical fiber strand 37, and the other end surface of the die 39 are pressed against the die 39 so that the die 39 can slide on the tip of the holder 30. Die attaching body 40 to be attached to
9, the optical fiber strand 37 fed from the rear end opening of the nipple 33 is fed from the optical fiber strand guiding nozzle 32. , Formed between the tip portion 31 of the nipple 33 and the resin guide wall 36 of the die 39,
The resin enters a resin coating chamber 43 that receives a supply of resin from a resin supply path 42 provided therein. The resin is coated here, and is taken out as an optical fiber core 44 from an optical fiber core extraction nozzle 38 of a die 39. I have.

[0003]

In the above-mentioned coating head, when the die 39 is aligned, the joining surface 35 of the die 39 on which the resin in the resin coating chamber 43 slides and the distal end surface 34 of the holder 30 are not aligned. It is feared that it will leak from between the rooms. Holder 3 to prevent this resin leakage
Although a sealing 45 is interposed between the leading end surface 34 of the die 39 and the joining surface 35 of the die 39, it is difficult to completely prevent leakage of the resin even with this.

When resin leaks from between the front end surface 34 of the holder 30 and the joining surface 35 of the die 39, the resin pressure in the coating head, that is, the resin coating chamber 43 is reduced, and the resin coating of the optical fiber is reduced. This uneven thickness of the coating resin causes the side pressure applied to the optical fiber to be evenly applied to the optical fiber, causing micro bending (microbending) to the optical fiber. Therefore, transmission loss increases. In addition, there is a concern about the influence on the fine operation of the adjustment mechanism 41 due to the seizure of the resin or the like.

SUMMARY OF THE INVENTION In view of the above, the present invention prevents the occurrence of resin leakage at the time of aligning a die, obtains a high-quality optical fiber core without uneven thickness of a coating resin, and adjusts the alignment of the die. An object of the present invention is to provide an optical fiber coating head which aims to eliminate the concern about the influence of the adjustment mechanism on the fine operation.

[0006]

In order to achieve the above object, the present invention provides a cylindrical holder provided with a resin supply passage, and an optical fiber wire guiding nozzle provided at the tip of a substantially conical tip. A nipple that is formed of a hollow body provided with a nipple and is attached to the holder; a resin guiding wall having a joint surface slidably joined to the tip end surface of the holder at one end surface and a substantially conical concave portion; A die provided with an optical fiber core ejection nozzle, and pressed against the other end surface of the die,
A die attachment body for slidably attaching the die to the tip of the holder; and an adjusting mechanism for sliding the die to align the die. The die has one end opened to the resin guiding wall and the other end opened. A resin passage opening to the die attachment body contact surface,
Further, the die attachment body is provided with a resin retaining groove communicating with the resin passage and having an opening area larger than an opening area of the resin passage on a die contact surface.

[0007]

[Function] The resin supplied at a predetermined pressure into the holder from the resin supply path of the holder fills the holder, and
The resin passages formed in the die are filled with the resin retaining grooves provided on the die contact surface of the die attaching body. When the resin stay groove is filled with the resin, the resin pressure is applied to the surface of the die exposed in the resin stay groove, and acts as a force for pressing the die to the tip of the holder and bringing the die into close contact. Thereby, the movement at the time of the alignment of the die becomes sliding while maintaining the state where the joining surface of the die is in close contact with the tip end surface of the holder by receiving the resin pressure in the resin retaining groove, and the inside of the holder is moved. Prevents resin leakage and keeps the resin pressure in the holder constant.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. 1 and 2 show an embodiment of the present invention, in which 1 is a cylindrical holder,
The wall of the holder 1 is provided with a resin supply path 2 for supplying a resin therein. 3 is provided with an optical fiber guide nozzle 6 at the tip of a tip 5 formed in a substantially conical shape;
The inside is a nipple made of a cylindrical hollow body having an optical fiber guide path 4, and is attached to the holder 1 by bolts 28. The tip 5 of the nipple 3 attached to the holder 1 is inserted into the holder 1.

Reference numeral 7 denotes a die attached to the tip of the holder 1. One end surface of the die 7 has the holder 1
And a resin guide wall 10 formed of a substantially conical concave portion. At the center of the resin guiding wall 10, an optical fiber core take-out nozzle 11 for forming a resin-coated outer shape of the optical fiber is provided.

The die 7 is attached to the tip of the holder 1 such that the resin guide wall 10 faces the opening of the tip of the holder 1, and the tip 5 of the nipple 3 is mounted on the die 7.
A resin coating chamber 12 is formed between the die and the resin guiding wall 10 of the die 7. The tip surface of the holder 1 with which the joining surface 9 of the die 7 contacts is formed on a surface orthogonal to the axis of the holder 1, and the die 7 joined to the tip surface 8 is orthogonal to the axis of the holder 1. Attached to slide in the direction.

Reference numeral 13 denotes a plate-shaped die attachment body which is pressed against the other end surface of the die 7 and slidably attaches the die 7 to the tip of the holder 1. The die mount 13 is bolted to a mounting frame 14 fixed to the end of the holder 1, and is mounted so as to press the die 7 against the end of the holder 1. A large-diameter hole 15 is provided at the center of the die attachment body 13 at a position corresponding to the optical fiber core extraction nozzle 11 provided on the die 7. Further, the die 7 is slid on the mounting frame 14 by centering the die 7, ie, the nipple 3.
An adjustment mechanism 16 having a miometer for aligning the optical fiber guide nozzle 6 with the optical fiber core extraction nozzle 11 of the die 7 is attached. 17,1
8 is a bolt.

The die 7 is provided with a resin passage 20 having one end opened to the resin guide wall 10 and the other end opened to the die attachment body contact surface 19. The plurality of resin passages 20 are provided at equal intervals on the same circumference around the optical fiber core extraction nozzle 11. In this embodiment, four resin passages 20 are provided. Further, the tip end surface of the die 7, that is, the die contact surface 21 of the die attach body 13 that contacts the die attach body contact surface 19, communicates with the resin passage 20 opened in the die attach body contact surface 19, and A resin stay groove 22 having an opening area larger than the opening area of the passage 20 is provided. The resin stay groove 22 is formed as a ring-shaped groove having a constant groove width communicating with each resin passage 20 provided in the die 7. Reference numeral 23 denotes an O-ring for sealing between the front end surface 8 of the holder 1 and the joining surface 9 of the die 7, and reference numerals 24 and 25 refer to O-rings for sealing between the die attaching body contact surface 19 and the die contact surface 21. , 26 is an optical fiber, and 27 is an optical fiber. In the above embodiment, the resin retaining groove 22 of the die attaching body 13 is formed as a ring-shaped groove. However, the resin retaining groove 22 may be provided so as to correspond to the plurality of resin passages 20.

Next, the operation of the above embodiment will be described.
From the resin supply path 2 of the holder 1 to the resin coating chamber 12
When a UV curable resin is supplied at a predetermined pressure, the resin fills the resin coating chamber 12 and passes through a resin passage 20 provided in the die 7 to form a resin retaining groove 22 provided in the die contact surface 21. Fulfill. When the resin stay groove 22 is filled with resin, the pressure of the resin is applied to the die take-out body contact surface 19 of the die 7 exposed in the resin stay 22, and the die 7 is moved to the tip of the holder 1. It acts as a force F to press and adhere to the surface. In the resin passage 20, a plurality of resin passages 20 are provided at equal intervals on the same circumference centered on the optical fiber take-out nozzle 11.
The resin stay groove 22 communicating with the plurality of resin passages 2
The resin pressure in the resin retaining groove 22 is evenly applied to the die 7 because the groove width communicating with 0 is formed in a ring-shaped groove having a constant width. To improve adhesion.

As a result, the movement of the die 7 during alignment is
Upon receiving the resin pressure in the resin retaining portion 22, the joining surface 9 of the die 7 is strongly pressed against the front end surface 8 of the holder 1 and slides while maintaining a state of close contact. The resin in the resin coating chamber 12 is prevented from leaking out from between the bonding surface 9 of the die 7 and the resin pressure in the resin coating chamber 12 is kept constant.

Accordingly, the optical fiber 26 guided from the optical fiber guide nozzle 6 into the resin coating chamber 12 through the optical fiber guide path 4 of the nipple 3 is:
The resin is coated by the resin pressure maintained at a uniform pressure in the resin coating chamber 12, and can be taken out from the optical fiber take-out nozzle 11 of the die 7 as an optical fiber core 27 without uneven thickness of the coating resin.

[0016]

As described above, according to the present invention, the resin pressure of the holder through the resin passage formed in the die is filled by the resin pressure filling the resin ditch formed in the die contact surface of the die attaching body. The die attached to the tip is strongly pressed against the tip of the holder to increase the adhesion to the tip of the holder, and even if the die is moved for alignment, resin leakage from the joint surface between the holder and the die Can be reliably prevented, the resin pressure in the holder can be kept constant, and a high-quality optical fiber core without uneven thickness of the coating resin can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view showing an example of a conventional optical fiber coating head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Holder 2 Resin supply path 3 Nipple 5 Tip part 6 Fiber optic wire guide nozzle 7 Die 8 Tip face 9 Joining face 10 Resin guide wall 11 Optical fiber core wire takeout nozzle 13 Die mounting body 16 Adjustment mechanism 19 Die mounting body contact Surface 20 Resin passage 21 Die abutment surface 22 Resin ditch 26 Optical fiber strand 27 Optical fiber core

Claims (3)

(57) [Claims] A cylindrical holder provided with a resin supply path;
A nipple, which is formed of a hollow body provided with an optical fiber guide nozzle at the tip of a substantially conical tip and is attached to the holder, and a joining surface slidably joined to the tip end surface of the holder at one end. A die having a resin guiding wall formed of a substantially conical concave portion and having an optical fiber core take-out nozzle at the center of the resin guiding wall, and being pressed against the other end surface of the die to slide the die to the tip of the holder. A die mounting body that can be mounted, and an adjusting mechanism that slides the die to align the die. The die has one end opened to the resin guiding wall and the other end opened to the die mounting body contact surface. An optical fiber coating head comprising: a resin passage formed in the die attachment body; and a resin ditch having an opening area larger than an opening area of the resin passage and communicating with the resin passage on a die contact surface of the die attachment body. 2. The optical fiber coating head according to claim 1, wherein a plurality of resin passages provided in said die are provided at equal intervals on a circumference centered on an optical fiber core take-out nozzle. 3. The resin retaining groove provided in the die attaching body,
3. The optical fiber coating head according to claim 1, wherein the optical fiber coating head is formed in a ring shape communicating with each resin passage provided in the die.