JPH07146428A - Band-shaped optical fiber tape core coating head - Google Patents

Abstract

PURPOSE:To prevent bubbles from being mixed in covering resin when resin coating is performed on plural optical fibers by arranging them in parallel with each other and extruding them continuously while making them travel. CONSTITUTION:A coating head for optical fiber tape has a resin supply port communicated with the outside to insert resin forcibly from outside, on a wall surface, a die 3 which is installed on the tip of a holder 2 and in which a fiber discharge port 9 is formed to regulate an external shape of a belt-like optical fiber whose almost center is covered with resin and a resin covered chamber 5 installed in a rear end part of the holder 2 so as to communicate with a resin supply port of the holder 2 between it and the die 3, and is composed of a nipple 4 having a nozzle which has a passing port 15 in the resin-covered chamber 5 so as to make plural optical fibers 300 travel in a condition of being properly arranged in parallel with each other, and the nipple 4 is formed so that a prescribed length from the tip of a nozzle part becomes a sharp part having an inclination angle theta less than 20 deg. in the traveling direction of the optical fiber 300.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating head for optical fiber ribbons, and more particularly to coating when a plurality of optical fiber strands are arranged in parallel while running and continuously extruded for resin coating. The present invention relates to a coating head for an optical fiber ribbon, which is capable of preventing air bubbles from entering the resin.

[0002]

2. Description of the Related Art Generally, an optical fiber has a remarkably different physical or mechanical characteristic from that of a conventional copper conductor. Various characteristics and easy handling. However, in the case of making a cable, if a large external force such as lateral pressure is applied to the optical fiber strand, a slight bending (microbending) occurs in the optical fiber core wire, which increases the transmission loss. Need to be considered. Considering this point, there is a spacer type as the structure of the optical fiber cable. This spacer type fiber cable
The structure is such that the mechanical characteristics of the cable are improved, and particularly high reliability against lateral pressure is obtained.

The optical fiber strand is a glass fiber that is drawn from an electric furnace and spun in an optical fiber drawing device, and is subjected to a primary coating and a secondary coating. In this state, the surface of this optical fiber strand is easily scratched and its mechanical strength is weak.Therefore, a single-core optical fiber core made of resin coating or multiple optical fiber strands arranged in parallel. To form a multi-fiber optical fiber ribbon which is lined up with and coated with a resin to form a tape.

An optical fiber tape core wire formed by combining a plurality of optical fiber element wires has conventionally been resin-coated with a coating head as shown in FIG. That is, the coating head 100 includes a holder 110 formed in a cylindrical shape, a die 120 attached to the holder 110, and a nipple 130. The die 120 is formed in a cylindrical shape and has a flange portion 1
Holder 11 by means of bolts (not shown) at 21
It is attached to 0. Reference numeral 122 denotes a fiber core wire outlet, which is an opening for discharging the resin coated on the optical fiber tape core wire to the outside of the coating head 100. The resin coated optical fiber tape core wire passing through the fiber core wire discharge port 122 is shown in FIG. It has the function of adjusting the outer shape. Reference numeral 123 denotes an open portion, which is formed in a truncated cone shape. After the fiber core wire outlet 122 regulates the outer shape of the optical fiber tape core wire,
The pressure is released so that the outer circumference of the fiber core is uniformly coated with the resin. Reference numeral 124 denotes a tapered portion for allowing the resin to be coated to flow smoothly.

At the rear end of the nipple 130, the flange portion 1
31 is formed, and the inside of the nipple 130, that is, the optical fiber introducing portion is hollow, and the hollow portion 132 is formed.
Are formed. This nipple 130 is a holder 1
It is fitted to the rear end of the holder 10, and is attached to the holder 11 by a bolt (not shown) at the flange of the nipple 130.
It is attached tightly to 0. A space is formed between the die 120 and the nipple 130, and the space is filled with a resin coating chamber 140 filled with the UV curable resin 200 that coats a plurality of optical fiber strands 300 bundled in a band.
Is formed.

Reference numeral 133 denotes a nozzle portion, which is formed so as to be narrowed from 20 ° to 45 ° from the contact surface of the nipple 130 with the holder 110 toward the fiber core wire outlet 122 of the die 120. Reference numeral 134 denotes a vertical end surface, which is the nozzle 133.
Is formed at the tip of the. Reference numeral 135 denotes a fiber core wire passing port, which communicates with the cavity 132. The fiber core wire passing port 135 is a state in which a plurality of optical fiber bare wires 300 introduced into the optical fiber introducing portion 132 are aligned in parallel. It is an insertion port that travels in and is fed into the resin coating chamber 140.

And, on the upper side wall of the holder 110,
A resin supply port 111 for introducing the UV curable resin 200 covering the plurality of optical fiber strands 300 aligned in parallel by the nipple 130 and bundled in a strip shape is provided. A resin transport pipe 400 is connected to the resin supply port 111, and a tip of the resin transport pipe 400 is connected to the resin supply device 500. This resin supply device 5
00 stores UV curable resin 200, and UV is appropriately supplied by supplying air 650 from the conduit 600.
The curable resin 200 is supplied to the resin transport pipe 400. In addition, on the lower side wall of the holder 110, in the UV curable resin 200 when the UV curable resin 200 is charged at the beginning of the production of the belt-shaped optical fiber core wires in the plurality of optical fiber element wires 300 bundled in the belt shape. May contain bubbles, and in order to prevent the resin containing bubbles from covering the strip-shaped optical fiber core, the resin that was added at the beginning of the manufacturing of the strip-shaped optical fiber was A resin overflow port 112 for discarding is provided. Also,
The resin supply port 111 communicates with the resin coating chamber 140. Therefore, when the resin 200 for coating is introduced from the resin supply port 111, the inside of the resin coating chamber 140 is exposed to UV.
It is filled with the curable resin 200.

As described above, in the coating head 100, a plurality of (for example, two, four, six, eight, etc.)
UV curable resin 2 is placed on the optical fiber strands 300 that are arranged.
00 is coated. Then, UV (ultraviol)
et) In a resin curing furnace such as a furnace, an optical fiber having a plurality of cores (2 cores, 4 cores, 6 cores, 8 cores, etc.) is obtained by curing the UV curable resin 200 coated on the plurality of optical fiber strands 300. The tape core wire 350 is manufactured.

[0009]

As described above, in the conventional coating head 100 for the optical fiber ribbon,
A plurality of optical fiber strands 300 continuously supplied to the nipple 130 are supplied to the resin coating chamber 140 in a state where they are aligned in parallel in the nipple 130, and a plurality of optical fibers parallelized in the resin coating chamber 140 are supplied. The UV curable resin 200 is extruded and coated on the outer circumference of the fiber strand 300.

However, a plurality of optical fiber strands 300
Where the nipple 130 exits, that is, the nipple 130
A surface perpendicular to the optical fiber strand 300 is formed at the tip of the nipple 13, and the nipple 13 forming this vertical surface is formed.
The thickness of the tip portion of 0 is formed with a considerable thickness. For this reason, the optical fiber strand 300 is attached to the nipple 130.
Is output from the tip of the optical fiber and travels in the resin coating chamber 140, and is pulled by the surface of the optical fiber element wire 300 to generate UV.
The curable resin 200 moves as shown by arrows A and B. Then, depending on the viscosity of the UV-curable resin 200 in the resin coating chamber 140, the UV-curable resin 200 that has been in contact with the tip of the nipple 130 by being pulled by the surface of the optical fiber element wire 300 of the nipple 130. Trying to get away from the tip.

On the other hand, the inside of the nipple 130, that is, the optical fiber introducing portion 132 is hollow, and the nipple 13
The supply side of the optical fiber strand 300 of 0 is open to the atmosphere side. Therefore, the UV curable resin 20
When 0 is about to leave the tip of the nipple 130, the pressure is reduced and a void 700 is generated. When the void 700 is generated, a suction force is generated in the portion of the void 700.
Due to this suction force, air is introduced from the gap between the inner wall of the outlet of the nipple 130 and the optical fiber strand 300 into the resin coating chamber 14
It is sucked into 0 as the optical fiber strand 300 runs. The air sucked from the outlet of the nipple 130 becomes air bubbles and is caught between the plurality of optical fiber strands 300. The UV curable resin 2 is attached to the outer circumference of the plurality of optical fiber strands 300 while the fine air bubbles are caught therein.
Since 00 is extruded and coated, bubbles 360 are mixed in the UV curable resin 200 coated on the outer periphery as shown in FIG.

When air bubbles 360 are mixed in the UV curable resin 200 coated on the outer circumference of the optical fiber element wire 300 in this manner, when uniform pressure is applied from the outside of the optical fiber tape core wire 350, the UV curable resin is cured. Since the degree of shrinkage of the bubble 360 is larger than the degree of shrinkage of the portion of the resin 200, stress is intensively applied to the bubble 360 and a minute bend (microbending) appears partially, and the optical fiber tape core There are problems that the transmission loss of the wire 350 increases and mechanical properties such as tensile strength and bending stress deteriorate. When bubbles 360 are mixed in the UV curable resin 200 coated on the outer circumference of the optical fiber strand 300, the thermal expansion coefficient of the bubbles 360 is larger than that of the UV curable resin 200, so that the ambient temperature changes. Then, it expands or contracts under the influence of the temperature change, but the difference in the coefficient of thermal expansion appears as a minute bend (microbending) in the optical fiber tape core wire 350, and the optical fiber tape core wire 350 is expanded. There is a problem that transmission loss increases.

An object of the present invention is to prevent air bubbles from being mixed into the coating resin when a plurality of optical fiber strands are arranged in parallel while running and continuously extruded for resin coating. is there.

[0014]

In order to achieve the above object, in a coating head for an optical fiber ribbon according to the present invention, a holder provided with a resin supply port that communicates with the outside and press-fits the resin from the outside into a wall surface. A die having a fiber core wire discharge port that is attached to the tip of the holder and regulates the outer shape of the band-shaped optical fiber core wire that is coated with resin in the substantially center, and is attached to the rear end of the holder,
A nozzle provided with a resin coating chamber communicating with the resin supply port of the holder between the die and a passage port for running a plurality of optical fiber strands in parallel in the resin coating chamber A nipple, and the nipple is formed as a sharp portion having a predetermined length from the tip of the nozzle portion and having an inclination angle of less than 20 ° with respect to the traveling direction of the optical fiber strand.

In order to achieve the above object, in the coating head for the optical fiber ribbon according to the present invention, a holder provided with a resin supply port communicating with the outside on the wall surface to press the resin from the outside, and the holder. A die having a fiber core outlet for controlling the outer shape of the band-shaped optical fiber core, which is attached to the tip of the optical fiber and is coated with a resin in the approximate center, and a die attached to the rear end of the holder, A resin coating chamber communicating with the resin supply port of the holder is formed between them, and a nipple with a nozzle having a passage port for running a plurality of optical fiber strands in parallel in the resin coating chamber is provided. The nipple is formed by forming a sharp portion having the same inclination angle as the nozzle and the inclination angle being less than 20 °.

Further, in order to achieve the above object, the coating head of the optical fiber ribbon according to the present invention is formed in a cylindrical shape with a resin supply port communicating with the outside and press-fitting the resin from the outside on the wall surface. A holder, a die attached to the tip of the holder and having a fiber core discharge port that regulates the outer shape of a band-shaped optical fiber core coated with resin in the approximate center, and a die attached to the rear end of the holder A nozzle provided with a resin coating chamber communicating with the resin supply port of the holder between the die and the die, and having a passage port for running a plurality of optical fiber element wires in parallel in the resin coating chamber. The nipple is provided with a thin-walled cylindrical portion protruding toward the fiber core wire discharge port of the die on the vertical end face of the tip of the nozzle portion.

Furthermore, in order to achieve the above object,
In the coating head of the optical fiber ribbon according to the present invention, a cylindrical holder having a resin supply port communicating with the outside and press-fitting the resin from the outside to the wall surface is attached to the tip of the holder, and the substantially central portion A die having a fiber core wire discharge port for regulating the outer shape of the band-shaped optical fiber core wire coated with resin, and a die attached to the rear end of the holder, and a resin supply port of the holder between the die and the die. And a nipple having a passage opening through which a plurality of optical fiber strands run in parallel in the resin coating chamber. A vertical surface is formed on the side of the resin coating chamber, the vertical surface is located in the vicinity of the resin supply port, and the optical fiber element wire introducing portion and the outlet of the thin-walled tubular portion are provided with a space.

[0018]

Function: A plurality of running optical fiber wires are introduced in parallel in a tape shape into the optical fiber wire introducing portion of the nipple. A plurality of optical fiber strands aligned in parallel run in the optical fiber strand introducing portion of the nipple, pass through the passage port, and are liquid UV from the resin supply port of the holder at a predetermined pressure.
The curable resin is introduced into the resin coating chamber. The plurality of optical fiber strands introduced into the resin coating chamber are coated with the UV curable resin in the resin coating chamber. When the plurality of optical fiber strands pass through the passage opening, the sharp portion extending from the nozzle is formed into a taper with an acute angle of less than 20 ° with respect to the traveling direction of the optical fiber strands of a predetermined length. ,
When the flow of the UV curable resin becomes smooth and the UV curable resin adheres to the multiple optical fiber strands from the tip of the nipple and tries to separate from the nipple, there is a gap between the UV curable resin and the outer wall surface of the nipple. Does not occur, and the suction force for sucking the air in the nipple does not occur. That is,
It is not necessary to extrude and coat the UV curable resin on the outer periphery in a state in which fine air bubbles are caught between a plurality of optical fiber strands.

Also, in the case where the nozzle of the nipple and the tip of the sharpened portion are formed with the same inclination angle and the passage portion is sharpened, the UV curable resin is formed along the outer wall surface of the tapered nipple. Is induced, and the flow of the UV curable resin becomes smooth to the tip of the passage opening. Therefore, when the UV curable resin is attached to the plurality of optical fiber strands from the tip of the nipple to separate from each other, no gap is generated between the UV curable resin and the outer wall surface of the nipple.

Further, a part of the rear end portion of the nipple is tightly fitted to the inner wall of the holder, and a thin-walled cylindrical body portion for guiding a plurality of optical fiber wires running to the passage forming portion at the front end of the die. Also in the case of the configuration in which it is projected toward the fiber core wire outlet, the UV curable resin is guided from the outer wall surface of the nipple to the passage opening forming portion, and further the outer peripheral surface of the thin-walled cylindrical body provided in the passage opening forming portion. Be guided through. When the UV curable resin adheres to the plurality of optical fiber wires from the tip of the cylinder at the tip of the nipple and tries to separate, the UV curable resin and the tip of the cylinder are thin. There is no room for a gap between and. Therefore, the suction force for sucking the air in the nipple does not occur. That is, it becomes unnecessary to extrude and coat the UV curable resin on the outer periphery in a state in which fine air bubbles are caught between a plurality of optical fiber strands.

Further, the nipple is fitted to the rear end of the holder, and a thin-walled cylindrical body is attached to the tip of the passage formed at a position where the center of the die is aligned with the fiber core outlet of the die. Even when the UV curable resin is projected toward the outlet, the UV curable resin is on the outer peripheral surface of the thin-walled cylinder provided in the passage forming portion, and the UV curable resin is plural from the cylinder tip at the tip of the nipple. When it adheres to the optical fiber strand of the book and tries to separate from it, it moves along the outer peripheral surface of the thin cylindrical body. When the plurality of optical fiber strands are attached to and separated from the tip of the tubular body, since the tubular body is thin, there is room for a gap between the UV curable resin and the tip of the tubular body. There is no. Therefore, it is not necessary to extrude and coat the UV curable resin on the outer periphery in a state where fine air bubbles are caught between the plurality of optical fiber strands.

[0022]

EXAMPLES Examples of coating heads for optical fiber ribbons according to the present invention will be described below. FIG. 1 shows a first embodiment of a coating head for an optical fiber ribbon according to the present invention.

In the figure, 1 is a coating head,
A plurality of flat optical fibers (for example, four, eight, etc.) that are guided from the guide member
A UV-curable resin 200 such as an acrylate, an acrylate, or an acrylate resin such as an acrylic resin is extrusion-coated. This UV curable resin 200
Has the property of curing when irradiated with ultraviolet rays,
Usually, it has a property of being cured by 90% or more just by irradiating it for about 1 second after coating the UV curable resin 200. In the coating head 1, a plurality of colored optical fiber element wires are arranged in parallel, and a transparent or semitransparent matrix material (liquid) is attached to the outer periphery thereof.

The coating head 1 is composed of a holder 2 formed in a cylindrical shape, a die 3 attached to the holder 2, and a nipple 4. A space is formed between the die 3 attached to the holder 2 and the nipple 4, and the space is filled with the UV curable resin 200 that covers the plurality of optical fiber strands 300 bundled in a band. The resin coating chamber 5 is formed.
On the upper side wall of the holder 2, a plurality of optical fiber strands 3 aligned in parallel by the nipple 4 and bundled in a band shape.
A resin supply port 6 for introducing the UV curable resin 200 for coating 00 is provided, and the resin supply port 6 communicates with the resin coating chamber 5. Further, on the lower side wall of the holder 2, a plurality of optical fiber strands 3 bundled in a strip shape are provided.
00 is a resin for discarding the UV curable resin that has been initially added at the start of the production of the band-shaped optical fiber core wire in order to prevent the UV curable resin containing bubbles from being covered at the time of initializing. An overflow port 7 is provided. Then, from the resin supply port 6, U for coating
When the V-curable resin 200 is charged, the inside of the resin coating chamber 5 becomes U.
Filled with V-curable resin 200.

The die 3 is formed in a cylindrical shape and has a flange portion 8 at one end. The die 3 is fitted to the tip of the cylindrical holder 2, and the flange portion 8 of the die 3 is attached to the holder 2 with a bolt (not shown). A fiber core wire outlet 9 that regulates the outer shape of the band-shaped optical fiber core wire coated with resin is formed at substantially the center of the die 3. Reference numeral 10 denotes an open portion, which is formed in a truncated cone shape and has a fiber core wire outlet 9
After the outer shape of the optical fiber ribbon is regulated by, the pressure is released so that the outer circumference of the fiber is uniformly coated with resin. Reference numeral 11 denotes a tapered concave portion forming one side wall (side wall of the outlet) of the resin coating chamber 5 having a substantially conical shape, which is for allowing the resin to be coated to flow smoothly. The nipple 4 is formed by a cylindrical main body portion 4a and a substantially conical nozzle portion 4b, and a flange portion 12 is provided on the main body portion 4a. The nipple 4 is tightly fitted to the rear end of the cylindrical holder 2 (closely to the inner wall of the holder 2), and the flange 12 of the nipple 4 is held by a bolt (not shown) in the holder 2 Is attached to. Further, the inside of the nipple 4, that is, the optical fiber introducing portion 13 through which the optical fiber strand 300 travels is hollow. The optical fiber introducing unit 13 is a place where a plurality of optical fiber strands 300 are guided and arranged in parallel. Further, the nipple 4 is formed such that a portion (tip portion) on the side opposite to the side where the flange portion 12 is formed is tapered from the tip of the inner wall contact surface of the holder 2 of the nipple 4 toward the center of the plurality of optical fiber strands 300. Nozzle part 14 is die 3
It is formed so as to face the tapered concave portion 11. Therefore, the space formed by the nozzle portion 14 of the nipple 4 and the tapered recess 11 of the die 3 is formed as the resin coating chamber 5. At the center of the tip of the nozzle portion 14, there is a passage port 15 for passing a plurality of optical fiber strands 300 in parallel at a position where the center coincides with the fiber core discharge port 9 of the die 3. The sharpened portion 16 that is formed projects from the resin coating chamber 5. The sharpened portion 16 extends from the nozzle portion 14 and becomes narrower in the running direction of the optical fiber strand 300, and the angle θ with respect to the optical fiber strand 300 is less than 20 °, preferably 16 °. It is formed below. The taper angle of the sharp portion 16 is larger than that of the nozzle portion 14 than the taper angle θ _1.
It is formed at an acute angle with respect to 0. And the sharpened portion 16
The tip of is sharp. That is, the sharp portion 16
Is formed in such a length that the tip end surface perpendicular to the optical fiber strand 300 becomes infinitely small. Further, the opening shape of the passage port 15 is formed into a substantially elliptical shape suitable for aligning a plurality of optical fiber element wires 300 in parallel and bundling them in a band shape.

Next, the operation of this embodiment will be described.
First, a plurality of optical fiber element wires 300 supplied from the supply device are collectively introduced into the optical fiber element wire introducing portion 13 of the nipple 4, and are arranged in a plurality of tapes in parallel. The plurality of optical fiber strands 300 aligned in parallel run in the optical fiber strand introducing portion 13 of the nipple 4, and pass the sharp portion 16 formed at less than 20 ° with respect to the optical fiber strand 300. The resin supply port 6 of the holder 2 is passed through the port 15.
Is introduced into the resin coating chamber 5 to which the liquid UV curable resin 200 is supplied at a predetermined pressure. The plurality of optical fiber strands 300 introduced into the resin coating chamber 5 are coated with the UV curable resin 200 in the resin coating chamber 5, and are molded into a predetermined shape at the fiber core wire outlet 9 at the center of the die 3. And is pulled out from the outlet of the die 3 on the flange portion 8 side.

When the plurality of optical fiber strands 300 pass through the passage port 15 and are coated with the UV curable resin 200, the plurality of optical fiber strands 300 passing through the sharpened portion 16 are not covered with the resin coating chamber. 5 is entered and coating is performed while pulling the resin in the resin coating chamber 5. At the time of this coating, the UV curable resin 200 flows from the nozzle portion 14 along the outer periphery of the sharpened portion 16. Then, the UV curable resin 200 adheres to the plurality of optical fiber strands 300 output from the sharp portions 16 of the nipple 4 and is attached to the sharp portions 16.
Since the sharp portion 16 is formed into a taper with an acute angle of less than 20 ° with respect to the running direction of the optical fiber strand 300 of a predetermined length when it is going to be separated from, the direction of the flow of the UV curable resin 200 is increased. The optical fiber strand 300 is smoothly followed without being changed, and is pulled, the depressurized state of the resin as seen at the tip of the nipple 130 of the conventional coating head 100 does not occur, and the occurrence of the void 700 is also seen. I can't. That is, there is no gap between the UV curable resin 200 and the sharp portion 16 which is the outer wall surface of the nipple 4, and the suction force for sucking the air in the nipple 4 is not generated. Therefore, the UV curable resin 200 is not extruded and covered on the outer periphery in a state where fine air bubbles are caught between the plurality of optical fiber strands 300, and the UV curable resin 200 is bundled into a band shape through the nipple 4 to form a resin coating chamber. The UV curable resin 200 containing no air bubbles is coated around the plurality of optical fiber strands 300 supplied to 5. In addition, when the angle of the sharpened portion 16 is set to less than 20 ° with respect to the optical fiber strand 300, as a result of the experiment,
May entrap air.

FIG. 2 shows a second embodiment of the coating head for the optical fiber ribbon according to the present invention. In the figure, the present embodiment differs from the embodiment shown in FIG. 1 in that the embodiment shown in FIG. 1 differs from the embodiment shown in FIG.
In addition, the nozzle portion 14 is extended from the nozzle portion 14
The taper-shaped sharp portion 16 of less than 20 ° is provided to the optical fiber strand 300 so that the optical fiber strand 300 becomes narrower in the traveling direction than the taper of the present embodiment. This is a point formed by the sharpened portions formed by the same taper from the nozzle to the tip of the sharpened portion. That is, in the figure, 20 is a coating head, which is composed of a holder 2 formed in a cylindrical shape, a die 3 attached to the holder 2, and a nipple 21. The holder 2 and the die 3 are the same as the holder 2 and the die 3 shown in FIG. Therefore, the description of the holder 2 and the die 3 is omitted here.

The nipple 21 is composed of a cylindrical main body portion 21a and a substantially conical nozzle portion 21b. The first nipple 21 shown in FIG.
It is attached to the holder 2 as in the embodiment. 22
Is a flange portion. Further, the inside of the nipple 21, that is, the optical fiber introducing portion 23 through which the optical fiber strand 300 runs is hollow, and a cavity is formed.
Reference numeral 24 denotes a sharpened portion that allows the plurality of optical fiber strands 300 formed in the nozzle portion 21b to pass in a state where they are aligned in parallel, and a plurality of sharpened portions from the inner wall contact surface of the holder 2 of the nipple body portion 21a to the tip of the sharpened portion 24. The outer peripheral surface of the nozzle portion 21b, which becomes thinner toward the center of the optical fiber strand 300, is integrally formed as one peripheral body. Further, the outer peripheral surface of the integrated nozzle portion 21b and the sharpened portion 24 are both formed with a taper angle of less than 20 ° with respect to the optical fiber element wire 300.

Therefore, according to the present embodiment, when the plurality of optical fiber strands 300 pass through the sharp portions 24 and are coated with the UV curable resin 200, the UV curable resin 200 is illustrated in FIG. As shown by the arrows A and B, the particles flow toward the center of the plurality of optical fiber strands 300 along the nozzle portion 21b. Then, the UV curable resin 200
Is attached to the plurality of optical fiber strands 300 output from the passage port 24a of the sharpened portion 24 and tends to separate from the sharpened portion 24, the nozzle portion 21b is continuously tapered to the tip of the sharpened portion 24. Therefore, UV curable resin 200
The optical fiber strand 300 is smoothly followed and pulled without significantly changing the direction of the flow, and the depressurized state of the resin as seen at the tip of the nipple 130 of the conventional coating head 100 does not occur. Therefore, it is not necessary to extrude and coat the UV curable resin 200 on the outer periphery in a state where fine air bubbles are caught between the plurality of optical fiber strands 300.

FIG. 4 shows a third embodiment of the coating head of the optical fiber ribbon according to the present invention. In the figure, the present embodiment differs from the embodiment shown in FIG. 1 in that the embodiment shown in FIG. 1 differs from the embodiment shown in FIG.
In addition, the nozzle portion 14 is extended from the nozzle portion 14
The taper-shaped sharp portion 16 of less than 20 ° is provided to the optical fiber strand 300 so that the optical fiber strand 300 becomes narrower in the traveling direction than the taper of the present embodiment. At the tip of the nozzle that is formed in a taper shape from the tip of the inner wall contact surface of the nipple holder, a thin-walled cylinder that guides multiple optical fiber strands passing through the passage of the nozzle is attached The point is that it is provided so as to project toward the exit. That is, in the drawing, 30 is a coating head, which is a holder 2 formed in a cylindrical shape.
And a die 3 attached to the holder 2 and a nipple 31. Holder 2 and die 3
Is the same as the holder 2 and the die 3 shown in FIG. Therefore, the description of the holder 2 and the die 3 is omitted here.

The nipple 31 comprises a cylindrical main body 31a and a substantially frustoconical nozzle 31b, and is attached to the holder 2 as in the first embodiment shown in FIG. 32 is a flange portion, and 33 is an inner space of the nipple 31, that is, an optical fiber introducing portion through which the optical fiber element wire 300 travels. Further, 31b is a plurality of optical fiber strands 3 from the inner wall contact surface of the holder 2 of the nipple 31.
00 is a nozzle portion that becomes thinner toward the center. Reference numeral 35 denotes a passage opening of the nozzle portion 31b, which is communicated with a passage opening of a thin-walled cylindrical body portion 36, which will be described later, and is formed at a position where the center coincides with the fiber core wire discharge opening 9 of the die 3. At the tip of the nozzle portion 31b, a thin-walled cylinder portion 36 that guides a plurality of optical fiber strands passing through the passage opening 35 is provided so as to project toward the fiber core wire outlet 9 of the die 3. . That is, the passage opening 35 of the nozzle portion 31 b and the passage opening 36 a of the thin-walled tubular body portion 36 communicate with each other, and the opening shape of the thin-walled tubular body portion 36 is the same as that of the passage opening 35. It is formed in a substantially elliptical shape suitable for bundling the strands 300 aligned in parallel. The thin-walled tubular portion 36 is formed thin because the optical fiber strand 30 of the thin-walled tubular portion 36 is formed.
This is because the tip surface perpendicular to 0 is made smaller.

Therefore, according to this embodiment, when the plurality of optical fiber strands 300 pass through the passage port 36a of the thin-walled tubular portion 36 and are coated with the UV curable resin 200, the UV curable resin 200 is Arrows C and D shown in FIG.
As shown in FIG. 5, it flows from the nozzle portion 31b along the thin-walled cylindrical body portion 36. Then, when the UV curable resin 200 adheres to the plurality of optical fiber strands 300 output from the thin-walled tubular body portion 36 of the nipple 31 and tries to separate from the thin-walled tubular body portion 36, Optical fiber strand 3 at the tip
UV curable resin 20
The flow direction of 0 smoothly follows the optical fiber element wire 300 without being largely changed, and is pulled, and a reduced pressure state of the resin occurs as seen at the tip of the nipple 130 of the conventional coating head 100. There is nothing to do.

As described above, when the light is output from the tip of the thin-walled cylindrical portion 36, the UV-curable resin 200 is discharged from the thin-walled cylindrical portion 36.
It is important to reduce the wall thickness T of the thin-walled cylindrical body portion 36 as shown in FIG. 6 in order to prevent a reduced pressure state due to the UV curable resin 200 from occurring when they are about to leave. When the wall thickness T of the thin-walled tubular portion 36 shown in FIG. 6 is reduced, the cut surface at the tip of the thin-walled tubular portion 36 becomes smaller, and the UV curable resin flowing along the outer peripheral surface of the thin-walled tubular portion 36. 200
Is a plurality of optical fiber strands 3 at the tip of the thin-walled tubular portion 36.
There is no room for generating a gap between the UV curable resin 200 and the cut surface of the tip end of the thin-walled cylindrical body portion 36 when the thin-walled cylindrical body portion 36 adheres to the substrate 00, and thus a depressurized portion is prevented from being generated. Therefore, it is not necessary to extrude and coat the UV curable resin 200 on the outer periphery in a state where fine air bubbles are caught between the plurality of optical fiber strands 300. The wall thickness is preferably equal to or greater than the diameter of the optical fiber, and in the example, 0.2 mm to
It is formed to 0.4 mm.

FIG. 7 shows a fourth embodiment of the coating head for the optical fiber ribbon according to the present invention. In the figure, the present embodiment differs from the third embodiment shown in FIG. 4 in that the third embodiment shown in FIG. 4 has a nozzle portion formed in a tapered shape from the tip of the inner wall contact surface of the holder 2 of the nipple 31. At the tip of 34, a thin-walled cylinder portion 36 for guiding a plurality of optical fiber strands is provided with a fiber core wire outlet 9 of the die 3.
In the present embodiment, a vertical surface is formed on the resin coating chamber side of the nipple, and this vertical surface is formed in the vicinity of the resin supply port, and at the same time as the optical fiber bare wire introducing portion. This is a point in which the outlets of the thin-walled cylindrical portions are separated.
That is, in the figure, 40 is a coating head, which is constituted by a holder 2 formed in a cylindrical shape, a die 3 attached to the holder 2, and a nipple 41. The holder 2 and the die 3 are the same as the holder 2 and the die 3 shown in FIG. Therefore, the description of the holder 2 and the die 3 is omitted here.

The nipple 41 is attached to the holder 2 as in the first embodiment shown in FIG. Reference numeral 42 is a flange portion, and 43 is an optical fiber introducing portion. Further, the nipple 41 is formed with a vertical surface 44, which is erected perpendicularly to the traveling direction of the plurality of optical fiber strands 300, at its tip (portion opposite to the side where the flange 42 is formed). Reference numeral 45 denotes a passage opening, which is formed at a position where the center coincides with the fiber core outlet 9 of the die 3. This nipple 4
On the vertical surface 44 of No. 1, the thin-walled cylindrical body portion 46 having the passage opening portion 46a for guiding the plurality of optical fiber strands passing through the passage opening 45 is connected to the passage opening 45. It is provided so as to project toward the wire discharge port 9. The reason why the thin-walled tubular portion 46 is formed thin is to reduce the tip surface of the thin-walled tubular portion 46 which is perpendicular to the optical fiber element wire 300.

Therefore, according to this embodiment, when a plurality of optical fiber strands 300 pass through the passage port 45 and are coated with the UV curable resin 200, the UV curable resin 200 is applied to the thin wall tube of the nipple 41. It adheres to the plurality of optical fiber element wires 300 output from the body portion 46, is pulled by the plurality of optical fiber element wires 300, and flows toward the tip on the outer peripheral surface of the thin-walled cylindrical body portion 46. When the UV curable resin 200 adheres to the plurality of optical fiber strands 300 output from the thin-walled tubular portion 46 of the nipple 41 and tries to separate from the tip of the thin-walled tubular portion 46, the thin-walled tubular portion is formed. 46
Since the vertical surface of the tip of the optical fiber to the optical fiber strand 300 is small, the direction of the flow of the UV curable resin 200 does not change greatly and smoothly follows the optical fiber strand 300 and is pulled. Head 100
The depressurized state of the resin as seen at the tip of the nipple 130 does not occur. Therefore, it is not necessary to extrude and coat the UV curable resin 200 on the outer periphery in a state where fine air bubbles are caught between the plurality of optical fiber strands 300.

[0038]

According to the present invention, since the tip portion is formed as a sharp portion having an acute angle of less than 20 ° with respect to the running direction of the optical fiber strand of a predetermined length, a plurality of optical fiber strands are formed. When the UV curable resin flows smoothly when exiting the passage opening and passing through the resin coating chamber, and when the UV curable resin adheres to the plurality of optical fiber strands from the tip of the nipple and separates, No air gap is generated between the curable resin and the outer wall surface of the nipple, and the suction force for sucking the air in the nipple is not generated. Therefore, according to the present invention, it is possible to prevent the outer periphery of the UV curable resin from being extruded and covered with fine air bubbles being caught between the plurality of optical fiber strands.

Further, according to the present invention, since the sharpened portion is integrally formed with the outer peripheral surface of the nozzle portion of the nipple as one peripheral body, the UV curable resin is provided along the nozzle portion at the passage of the sharpened portion. When the UV curable resin flows smoothly to the tip and tries to separate from the tip of the nipple onto a plurality of optical fiber strands, a gap is created between the UV curable resin and the outer wall surface of the nipple. There is no. Therefore, it is possible to prevent the UV curable resin from being extruded and coated on the outer periphery in a state where fine air bubbles are caught between the plurality of optical fiber strands.

Further, according to the present invention, since the thin-walled cylinder portion is made to project toward the fiber core wire discharge port of the die at the nozzle portion of the nipple fitted to the inner wall of the holder, UV curing is performed. The mold resin is guided to the passage opening forming portion, and further guided through the outer peripheral surface of the thin-walled cylinder body provided in the passage opening forming portion, and the UV curable resin is fed from the tip of the cylinder body at the tip of the nipple to a plurality of optical fibers. There is no room for a gap to be formed between the UV curable resin and the tip of the tubular body when it is attached to the strand and is going to be separated. Therefore, according to the present invention, it is possible to prevent the outer periphery of the UV curable resin from being extruded and covered with fine air bubbles being caught between the plurality of optical fiber strands.

Furthermore, according to the present invention, a vertical surface is formed on the resin coating chamber side of the nipple, the vertical surface is formed in the vicinity of the resin supply port, and the optical fiber core wire introducing portion and the thin-walled tubular portion are formed. Since the outlets are separated, the UV curable resin is on the outer peripheral surface of the thin-walled tubular portion, and when the thin-walled tubular portion is attached to a plurality of optical fiber strands to be separated from each other. , Because it moves along the outer peripheral surface of the thin-walled cylinder,
There is no room for a gap between the UV curable resin and the tip of the thin-walled cylindrical body. Therefore, according to the present invention, it is possible to prevent the outer periphery of the UV curable resin from being extruded and covered with fine air bubbles being caught between the plurality of optical fiber strands.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a coating head for an optical fiber ribbon according to the present invention.

FIG. 2 is a sectional view showing another embodiment of the coating head for the optical fiber ribbon according to the present invention.

FIG. 3 is a partially enlarged cross-sectional view of a coating head for explaining a resin flow in the coating head illustrated in FIG.

FIG. 4 is a cross-sectional view showing another embodiment of the coating head of the optical fiber ribbon according to the present invention.

5 is a partially enlarged cross-sectional view of the coating head for explaining the flow of resin in the coating head shown in FIG.

FIG. 6 is a diagram for explaining the principle that a resin pressure reducing portion does not occur at the tip of the cylindrical body in the coating head shown in FIG.

FIG. 7 is a sectional view showing still another embodiment of the coating head for the optical fiber ribbon according to the present invention.

FIG. 8 is a cross-sectional view showing a conventional coating head for an optical fiber ribbon.

9 is a partially enlarged cross-sectional view of a coating head for explaining a state in which voids are generated by the flow of resin in the conventional coating head shown in FIG.

FIG. 10 is a sectional view of an optical fiber element wire coated with a UV curable resin by a conventional coating head for an optical fiber ribbon.

[Explanation of symbols]

1,20,30,40 ………………………………………………
Coating head 2 …………………………………………………………………………
Holder 3 ……………………………………………………………………
Die 4, 21, 31, 41 ………………………………………………
Nipple 5 ……………………………………………………………………
Resin coating room 9 ……………………………………………………………………
Fiber core outlet 11,33 ………………………………………………………………
Tapered recess 13,23,35,43 …………………………………………
Optical fiber strand introduction part 14, 21b, 31b ………………………………………………
Nozzle part 15, 24a, 36a, 45 …………………………………………
Passageway 16, 24 …………………………………………………………
Sharp part 36,46 …………………………………………………………
Thin-walled cylinder part 44 ……………………………………………………………………
Vertical plane 200 ………………………………………………………………
UV curable resin 300 ………………………………………………………………
Optical fiber strand 700 ………………………………………………………………
Void

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[Procedure amendment]

[Submission date] March 9, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

At the rear end of the nipple 130, the flange portion 1
31 is formed, and the inside of the nipple 130, that is, the optical fiber introducing portion is hollow, and the hollow portion 132 is formed.
Are formed. This nipple 130 is a holder 1
10 is fitted to the rear end of the nipple 130, and is tightly attached to the holder 110 with a flange portion 131 of the nipple 130 by a bolt (not shown). A space is formed between the die 120 and the nipple 130, and the plurality of optical fiber strands 300 in which the space is bundled in a band shape.
A resin coating chamber 140 filled with the UV curable resin 200 is formed.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

When the plurality of optical fiber strands 300 pass through the passage port 15 and are coated with the UV curable resin 200, the plurality of optical fiber strands 300 passing through the sharpened portion 16 are not covered with the resin coating chamber. 5 is entered and coating is performed while pulling the resin in the resin coating chamber 5. At the time of this coating, the UV curable resin 200 flows from the nozzle portion 14 along the outer periphery of the sharpened portion 16. Then, the UV curable resin 200 adheres to the plurality of optical fiber strands 300 output from the sharp portions 16 of the nipple 4 and is attached to the sharp portions 16.
Since the sharp portion 16 is formed into a taper with an acute angle of less than 20 ° with respect to the running direction of the optical fiber strand 300 of a predetermined length when it is going to be separated from, the direction of the flow of the UV curable resin 200 is increased. The optical fiber strand 300 is smoothly followed without being changed, and is pulled, the depressurized state of the resin as seen at the tip of the nipple 130 of the conventional coating head 100 does not occur, and the occurrence of the void 700 is also seen. I can't. That is, there is no gap between the UV curable resin 200 and the sharp portion 16 which is the outer wall surface of the nipple 4, and the suction force for sucking the air in the nipple 4 is not generated. Therefore, the UV curable resin 200 is not extruded and covered on the outer periphery in a state where fine air bubbles are caught between the plurality of optical fiber strands 300, and the UV curable resin 200 is bundled into a band shape through the nipple 4 to form a resin coating chamber. The UV curable resin 200 containing no air bubbles is coated around the plurality of optical fiber strands 300 supplied to 5. In addition, when the angle of the sharp portion 16 is 20 ° or more with respect to the optical fiber strand 300, the result of the experiment shows that
May entrap air.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

As described above, when the light is output from the tip of the thin-walled cylindrical portion 36, the UV-curable resin 200 is discharged from the thin-walled cylindrical portion 36.
It is important to reduce the wall thickness T of the thin-walled cylindrical body portion 36 as shown in FIG. 6 in order to prevent a reduced pressure state due to the UV curable resin 200 from occurring when they are about to leave. When the wall thickness T of the thin-walled tubular portion 36 shown in FIG. 6 is reduced, the cut surface at the tip of the thin-walled tubular portion 36 becomes smaller, and the UV curable resin flowing along the outer peripheral surface of the thin-walled tubular portion 36. 200
Is a plurality of optical fiber strands 3 at the tip of the thin-walled tubular portion 36.
There is no room for generating a gap between the UV curable resin 200 and the cut surface of the tip end of the thin-walled cylindrical body portion 36 when the thin-walled cylindrical body portion 36 adheres to the substrate 00, and thus a depressurized portion is prevented from being generated. Therefore, it is not necessary to extrude and coat the UV curable resin 200 on the outer periphery in a state where fine air bubbles are caught between the plurality of optical fiber strands 300. The wall thickness is preferably equal to or less than the diameter of the optical fiber, and in the example, 0.2 mm to
It is formed to 0.4 mm.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction content]

Further, according to the present invention, since the thin-walled cylinder portion is made to project toward the fiber core wire discharge port of the die at the nozzle portion of the nipple fitted to the inner wall of the holder, UV curing is performed. Mold resin is guided to the nozzle ,
When the UV curable resin is guided through the outer peripheral surface of the thin-walled cylindrical body provided at the tip of the nozzle portion, and adheres to a plurality of optical fiber strands from the tip of the cylindrical body at the tip of the nipple and tries to separate from it. In addition, there is no room for a gap between the UV curable resin and the tip of the cylinder. Therefore, according to the present invention, it is possible to prevent the outer periphery of the UV curable resin from being extruded and covered with fine air bubbles being caught between the plurality of optical fiber strands.

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Change

[Correction content]

[Figure 3]

Claims (4)

[Claims] 1. A holder provided with a resin supply port communicating with the outside on the wall surface to press-fit the resin from the outside, and an outer shape of a strip-shaped optical fiber core attached to the tip of the holder and covered with the resin in the approximate center. Attached to the rear end of the holder and a die having a fiber core outlet for regulating
A nozzle provided with a resin coating chamber communicating with the resin supply port of the holder between the die and a passage port for running a plurality of optical fiber strands in parallel in the resin coating chamber A strip-shaped optical fiber having a predetermined length from the tip of the nozzle portion as a sharp portion having an inclination angle of less than 20 ° with respect to the running direction of the optical fiber strand. Tape core coating head. 2. An outer shape of a belt-shaped optical fiber core which is provided at the tip of the holder and which is provided with a resin supply port that communicates with the outside on the wall surface and press-fits the resin from the outside, and whose center is covered with the resin. Attached to the rear end of the holder and a die having a fiber core outlet for regulating
A nozzle provided with a resin coating chamber communicating with the resin supply port of the holder between the die and a passage port for running a plurality of optical fiber strands in parallel in the resin coating chamber A nipple, wherein the nipple has the same inclination angle as the nozzle and the inclination angle is 2
A coating head for a ribbon-shaped optical fiber ribbon, which is formed by forming a sharp portion of less than 0 °. 3. A holder, which is formed in a tubular shape and has a resin supply port that communicates with the outside on the wall surface and presses the resin from the outside, and a strip-shaped optical fiber that is attached to the tip of the holder and is covered with the resin in the approximate center. A die having a fiber core outlet for regulating the outer shape of the core is attached to the rear end of the holder, and a resin coating chamber communicating with the resin supply port of the holder is formed between the die and the die. A nipple with a nozzle provided with a passage opening for running a plurality of optical fiber strands aligned in parallel in the resin coating chamber, the nipple having a vertical end face at the tip of the nozzle portion. A coating head for a ribbon-shaped optical fiber tape core, wherein the thin-walled cylindrical portion is provided so as to protrude toward the fiber core wire discharge port of the die. 4. A holder, which is formed in a tubular shape and has a resin supply port that communicates with the outside on the wall surface and press-fits the resin from the outside, and a band-shaped optical fiber that is attached to the tip of the holder and is covered with the resin in the approximate center. A die having a fiber core outlet for regulating the outer shape of the core is attached to the rear end of the holder, and a resin coating chamber communicating with the resin supply port of the holder is formed between the die and the die. , A nipple having a passage opening for running a plurality of optical fiber strands arranged in parallel in the resin coating chamber, the nipple having a surface vertical to the resin coating chamber side of the nipple. A coating head for a ribbon-shaped optical fiber ribbon, which is formed by forming the vertical surface in the vicinity of the resin supply port and in which the optical fiber element introducing portion and the outlet of the thin-walled tubular portion are separated from each other.