JPH07209561A - Optical fiber coating head - Google Patents

Abstract

PURPOSE:To obtain a coated optical fiber having good quality free from unequal thickness of a coating resin by preventing generation of resin leakage at the time of aligning a die. CONSTITUTION:This optical fiber coating head has a holder 1 which is provided with a resin supply path 2, a nipple 3 which has an optical fiber guiding nozzle 6 at its front end and is mounted at this holder 1, a die 7 which has a joint surface 9 to be freely slidably joined to the front end face 8 of the holder l and a resin guiding wall 10 consisting of a recessed point of an approximately circular conical shape at its one end face and is provided with a coated optical fiber taking out nozzle 11 at the center of this resin guiding wall 10, a die mounting body 13 which mounts the die 7 slidably at the front end of the holder 1 by making pressurized contact with the other end face of the die 7 and an adjusting mechanism 16 which aligns the die 7 by sliding the die 7. The die 7 is provided with a resin passage 20 which opens at one end to the resin guiding wall 10 and opens at the other end to the contact surface 19 of the die mounting body. The die mounting body 13 is provided with a resin reserving groove 22 which communicates with the resin passage 20 and has an opening area larger than the opening area of the resin passage 20 at the die contact surface 21.

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 element wire with a resin when manufacturing an optical fiber core wire.

[0002]

2. Description of the Related Art A coating head as shown in FIG. 3 has been known as an apparatus for coating a resin on an optical fiber when manufacturing an optical fiber. This coating head includes a cylindrical holder 30 provided with a resin supply path 42,
The holder 31 is formed of a hollow body in which the tip portion 31 is protruded in a substantially conical shape and an optical fiber element guide nozzle 32 is provided at the tip of the holder 30. A nipple 33 attached to the rear end, a joint surface 35 slidably joined to the front end surface 34 of the holder 30 on one end surface, and a resin guide wall 36 composed of a substantially conical recess, and the center of the resin guide wall 36. A die 39 provided with an optical fiber core wire 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 by pressure contact, and the die 39 can slide on the tip of the holder 30. Attached to the die 40 and the die 3
9 is slid to adjust the die 39, and the optical fiber strand 37 fed from the rear end opening of the nipple 33 is fed from the optical fiber strand guide nozzle 32. Formed between the tip portion 31 of the nipple 33 and the resin guide wall 36 of the die 39,
The resin coating chamber 43 receives the resin supplied from the resin supply passage 42 provided at the position where the resin is coated and is taken out as the optical fiber core wire 44 from the optical fiber core wire take-out nozzle 38 of the die 39. There is.

[0003]

In the above 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 tip surface 34 of the holder 30 are formed. There is a concern that it will leak from between. Holder 3 to prevent this resin leakage
Although the sealing 45 is interposed between the front end surface 34 of 0 and the bonding surface 35 of the die 39, even with this, it is difficult to completely prevent the leakage of the resin.

When resin leakage occurs between the tip surface 34 of the holder 30 and the bonding surface 35 of the die 39, the resin pressure in the coating head, that is, in the resin coating chamber 43 decreases, and the coating resin for the optical fiber strands is reduced. This uneven thickness of the coating resin causes the lateral pressure applied to the optical fiber element wire to not evenly apply to the optical fiber element wire, and causes minute bending (microbending) in the optical fiber element wire. , Will increase the transmission loss. Further, there is a concern that the fine movement of the adjusting mechanism 41 may be affected by the seizure of the resin or the like.

In view of the above points, the present invention prevents the occurrence of resin leakage at the time of centering the die, makes it possible to obtain a high-quality optical fiber core without uneven thickness of the coating resin, and aligns the die. (EN) An optical fiber coating head intended to eliminate the fear of the influence of the adjusting mechanism on the fine movement.

[0006]

In order to achieve the above object, the present invention has a cylindrical holder provided with a resin supply passage and an optical fiber strand guide nozzle at the tip of the tip portion formed in a substantially conical shape. A nipple which is made up of a hollow body and is attached to a holder, and a resin guide wall consisting of a conical surface and a joint surface which slidably joins the tip surface of the holder at one end surface, and the center of the resin guide wall A die provided with an optical fiber core wire extraction nozzle, and by pressure contact with the other end surface of the die,
It consists of a die mounting body that slidably attaches the die to the tip of the holder, and an adjusting mechanism that slides the die to align the die. One end of the die is opened in the resin guide wall and the other end is opened. Is provided with a resin passage opening to the die attachment body contact surface,
Further, in the die mounting body, a resin retaining groove is provided on the die contact surface so as to communicate with the resin passage and have an opening area larger than the opening area of the resin passage.

[0007]

[Function] The resin supplied from the holder resin supply path into the holder at a predetermined pressure fills the holder and
The resin retaining groove provided in the die contact surface of the die mounting body is filled through the resin passage provided in the die. When the resin retaining groove is filled with the resin, the resin pressure is applied to the surface of the die exposed in the resin retaining groove, and works as a force for pressing the die to the tip of the holder to bring the die into close contact. As a result, the movement of the die at the time of aligning becomes sliding while receiving the resin pressure in the resin retaining groove and maintaining the state that the joining surface of the die is in close contact with the tip surface of the holder. Prevents resin leakage and keeps the resin pressure in the holder constant.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. 1 and 2 show an embodiment of the present invention, in which 1 is a cylindrical holder,
A resin supply path 2 for supplying resin is provided inside the wall of the holder 1. 3, an optical fiber strand guide nozzle 6 is provided at the tip of a tip portion 5 formed in a substantially conical shape,
Then, the inside is a nipple made of a cylindrical hollow body that serves as the optical fiber strand guide path 4, and is attached to the holder 1 by a bolt 28. The tip 5 of the nipple 3 attached to the holder 1 is inserted into the holder 1.

A die 7 is attached to the tip of the holder 1. The holder 1 is attached to one end surface of the die 7.
Has a joint surface 9 slidably joined to the front end surface 8 and a resin guide wall 10 composed of a substantially conical recess. At the center of the resin guiding wall 10, an optical fiber core wire take-out nozzle 11 for forming a resin-coated outer shape of an optical fiber element wire is provided.

The die 7 is attached to the tip of the holder 1 so that the resin guide wall 10 faces the tip opening of the holder 1, and the tip 5 of the nipple 3 is attached.
A resin coating chamber 12 is formed between the resin guiding wall 10 of the die 7 and the resin guiding wall 10. The tip surface of the holder 1 with which the joining surface 9 of the die 7 abuts is formed in a plane 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. It is mounted so as to slide in the direction.

Reference numeral 13 denotes a plate-shaped die mounting body which is pressed against the other end surface of the die 7 and slidably mounts the die 7 on the tip of the holder 1. The die attachment body 13 is attached to the attachment frame 14 fixed to the tip of the holder 1 by bolts so that the die 7 is pressed against the tip of the holder 1. A large-diameter hole 15 is provided in the center of the die mounting body 13 at a position corresponding to the optical fiber core take-out nozzle 11 provided in the die 7. Further, the die 7 is slid on the mounting frame 14 to align the die 7, that is, the nipple 3
An adjusting mechanism 16 equipped with a myrometer for aligning the optical fiber bare wire guiding nozzle 6 and the optical fiber taking-out 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. A plurality of resin passages 20 are provided at equal intervals on the same circumference centered on the optical fiber core take-out nozzle 11. In this embodiment, four resin passages 20 are provided. In addition, the tip end surface of the die 7, that is, the die contact surface 21 of the die attachment body 13 that contacts the die attachment body contact surface 19, communicates with the resin passage 20 that opens to the die attachment body contact surface 19 and is made of resin. A resin retaining groove 22 having an opening area larger than the opening area of the passage 20 is provided. The resin retaining groove 22 is formed as a ring-shaped groove having a constant groove width that communicates with each resin passage 20 provided in the die 7. Reference numeral 23 is an O-ring that seals between the tip surface 8 of the holder 1 and the joint surface 9 of the die 7, and 24 and 25 are O-rings that seal between the die mounting body contact surface 19 and the die contact surface 21. , 26 are optical fiber strands, and 27 is an optical fiber core wire. Although the resin retaining groove 22 of the die mounting body 13 is formed as a ring-shaped groove in the above embodiment, it 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 the UV curable resin is supplied at a predetermined pressure, the resin fills the resin coating chamber 12 and passes through the resin passage 20 provided in the die 7 to form the resin retaining groove 22 provided in the die contact surface 21. Fulfill. When the resin is filled in the resin retaining groove 22, the pressure of the resin is applied to the die pick-up body contact surface 19 of the die 7 exposed in the resin retaining 22, and the die 7 is attached to the tip of the holder 1. It acts as a force F that is pressed against and adheres to. 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 core extraction nozzle 11.
The resin retaining groove 22 communicating with the
Since it is formed as a ring-shaped groove having a constant groove width communicating with 0, the resin pressure in the resin retaining groove 22 is uniformly applied to the die 7, and the joining surface 9 of the die 7 and the tip surface 8 of the holder 1 are formed. Improves adhesion with.

As a result, the movement of the die 7 during alignment is
When the resin pressure in the resin retaining portion 22 is received, the joint surface 9 of the die 7 is strongly pressed against the tip surface 8 of the holder 1 and slides while maintaining a close contact with the tip surface 8 of the holder 1. The resin in the resin coating chamber 12 is prevented from leaking to the outside through the space between the die 7 and the joint surface 9, and the resin pressure in the resin coating chamber 12 is kept constant.

Therefore, the optical fiber strand 26 guided through the optical fiber strand guide path 4 of the nipple 3 from the optical fiber strand guide nozzle 6 into the resin coating chamber 12 is
The coating is performed by the resin pressure kept at a uniform pressure in the resin coating chamber 12, and the optical fiber core 27 having no uneven thickness of the coating resin can be taken out from the optical fiber core take-out nozzle 11 of the die 7.

[0016]

As described above, according to the present invention, the pressure of the resin of the holder is filled by the resin pressure which fills the resin retaining groove provided on the die contact surface of the die mounting body through the resin passage provided in the die. The die attached to the tip is strongly pressed against the tip of the holder to increase adhesion with the tip surface of the holder, and even if the die is moved for centering, resin leakage from the joint surface of the holder and die Since it is possible to reliably prevent the occurrence of the above, it is possible to keep the resin pressure in the holder constant, and thus it is possible to obtain a high-quality optical fiber core wire without uneven thickness of the coating resin.

[Brief description of 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 Optical fiber bare wire guide nozzle 7 Die 8 Tip surface 9 Joining surface 10 Resin guide wall 11 Optical fiber core wire take-out nozzle 13 Die mount 16 Adjustment mechanism 19 Die mount contact Surface 20 Resin passage 21 Die contact surface 22 Resin retaining groove 26 Optical fiber element wire 27 Optical fiber core wire

Claims (3)

[Claims] 1. A cylindrical holder provided with a resin supply path,
A nipple that is attached to a holder and is composed of a hollow body provided with an optical fiber element guide nozzle at the tip of the tip formed in a substantially conical shape, and a joint surface that is slidably joined to the tip surface of the holder at one end surface. A die having a resin guide wall consisting of a substantially conical recess, and an optical fiber core wire extraction nozzle provided in the center of the resin guide wall, and the other end surface of the die under pressure contact, and the die slides on the tip of the holder. It consists of a die attachment body that can be attached and an adjustment mechanism that aligns the die by sliding the die.One end of the die is opened in the resin guide wall and the other end is opened in the die attachment body contact surface. An optical fiber coating head, wherein a resin passage is provided, and the die mounting 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. 2. The optical fiber coating head according to claim 1, wherein a plurality of resin passages provided in the die are provided at equal intervals on a circumference centered on the optical fiber core take-out nozzle. 3. The resin retaining groove provided in the die mounting body,
An optical fiber coating head formed in a ring shape that communicates with each resin passage provided in a die.