JPH0453616Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is aimed at an apparatus for manufacturing tape-shaped optical fiber cores, and more specifically, The present invention relates to an apparatus for forming a coating layer.

(Prior art) The optical fiber core wire of the above type has a structure in which a plurality of strands (wires in which the optical fiber body is covered with a primary coating layer) arranged on the same plane are covered with a synthetic resin coating layer. , and has a flat cross-sectional shape as a whole.

In such optical fiber core wires, uncured resin is attached to a collection of multiple strands, and the uncured resin is molded into a predetermined shape by passing through a die hole in that state, and then the resin is heated using an ultraviolet lamp device. The coating layer is completed by cross-linking and curing.

(Prior art) Since the above-mentioned uncured resin is in a liquid state, the resin deforms due to its own surface tension etc. after passing through the die hole and before reaching the irradiation area (curing area) of the ultraviolet lamp device. When this amount of deformation increases, it becomes difficult to accurately set the dimensions and shape of the coating layer at the product stage. Therefore, in order to reduce the flow deformation of the liquid resin and improve the accuracy of the dimensional shape of the coating layer, the distance from the exit of the die hole to the irradiation area is shortened, and that section is It is preferable that the structure is such that the attached strands of wire pass through in a short period of time.

However, in order to mold resin with a predetermined precision using a die, it is necessary to maintain the die at a low temperature (for example, room temperature), whereas heat is generated in the ultraviolet lamp device and its irradiation area. Therefore, if the distance between the die and the ultraviolet lamp device is shortened, heat from the ultraviolet lamp device and the irradiation area is transmitted to the die, making it impossible to maintain the temperature of the die low.

(Problems to be Solved by the Invention) In order to solve the above-mentioned problems, the present invention proposes that the material of the optical fiber core is composed of the optical fiber element and the uncured resin for the coating layer attached around the optical fiber. A die for molding the outer periphery of the uncured resin into a predetermined size and shape is provided at the upper part of the processing section in which the core material moves vertically downward, and a die for molding the outer periphery of the uncured resin into a predetermined size and shape is provided at the lower part of the processing section. A curing device for curing the resin is provided, a heat insulating device is provided in the middle of the processing section, and the heat insulating device is provided with heat in the partition structure located between the upper space on the die side and the lower space on the curing device side. It is characterized by the provision of a shielding plate.

Further, in the embodiment, the passage hole provided in the heat shielding plate for passing the strand assembly is set to have an appropriate size and shape, and the distance between the inner periphery of the passage hole and the strand assembly is An orifice is formed to regulate the flow of atmosphere from the lower space to the upper space.

Further, in an embodiment, the heat insulating device includes a heat insulating member between the heat shield plate and the curing device. The heat insulating device may also be provided with means for supplying cooling gas to the lower space.

(Function) According to the configuration of the present invention described above, the heat generated from the curing device is blocked by the heat insulating device and is not transmitted to the die at all (or hardly at all). Therefore, an increase in the temperature of the die is effectively prevented.

(Example) First, the optical fiber core 1 manufactured by the apparatus according to the embodiment of the present invention will be described. In FIG. 2, the optical fiber core 1 is composed of a plurality of (for example, four) strands 2 arranged in the same plane, and a coating layer 3 that covers a collection of these strands 2.
The overall outer circumferential shape is an elongated oval. Each strand 2 is composed of an optical fiber body and a synthetic resin outer sheath covering it. The covering layer 3 is made of, for example, a polyurethane acrylate resin, an epoxy urethane resin, or a polybutadiene acrylate resin.

The apparatus for forming the coating layer 3 is constructed as shown in FIG. In the apparatus shown in FIG. 1, a resin supply section 10, a die 11, a heat insulating device 12, and a curing device 13 are provided in order from the top. The strands 2 are fed downward from above in an aligned state as shown in FIG. 2 to the illustrated processing section in which these devices and processing sections are arranged.

The resin supply section 10 serves as a kind of liquid resin reservoir, and when the wire 2 passes therethrough, the liquid resin for the coating layer 3 adheres to the periphery of the wire 2 . The bottom wall of this resin reservoir is formed by a die 11.

The die 11 is for molding the resin attached to the wire 2 into a predetermined size and shape, and is provided with a die hole 15 through which the wire 2 with the resin attached passes through. The dimensions and shape of the die hole 15 generally correspond to the dimensions and shape of the coating layer 3. Specifically, the resin attached to the wire 2 is molded by passing through the die hole 15, and then flows and deforms to some extent due to surface tension etc. until it reaches the crosslinking hardening area 16, which will be described later. The size and shape of the die hole 15 are appropriately set in consideration of the above-mentioned flow deformation so that the coating layer 3 has a predetermined size and shape after being cured in the hardening region 16.

The curing device 13 basically consists of a UV (ultraviolet) lamp and a reflecting mirror, and has a space (i.e., a cross-linked curing area 1
6), the resin is crosslinked and cured by the ultraviolet rays (and infrared rays) irradiated from the curing device 13 as the wire 2 with the resin attached passes therethrough, thereby completing the coating layer 3.

In the above-mentioned curing process, the curing device 13 itself generates heat, and the space within the crosslinking curing region 16 and the space 17 above it are also heated.
1, the insulation device 12 is provided.

The insulation device 12 includes a generally horizontal heat shield plate 20 that covers the cross-linked cure area 16 and the space 17 above it. The heat shielding plate 20 is provided with a passage hole 21 through which the wire 2 coated with resin passes. The dimensions of this passage hole 21 are set small enough to avoid contact with the resin around the wire 2, and constitute a kind of orifice. This orifice is the lower space 17
Almost completely (or significantly) prevents atmospheric gas from flowing into the upper space 22 above the heat shielding plate 20.
To prevent. The outer periphery of the heat shielding plate 20 is seated on the upper surface of the curing device 13 with a plurality of layered heat insulating films 23 interposed therebetween. Furthermore, a gas inlet 25 is provided on the outer periphery of the heat shield plate 20 for supplying an inert gas such as nitrogen to the lower space 17 from an external gas supply source (not shown). Further, a slit is formed in the heat insulating film 23 in the assembled state, and the slit serves as a gas outlet 27.

By configuring the heat insulating device 12 in this way, the heat shielding plate 20 prevents the heat of the curing device 13, the cross-linked curing region 16, and the lower space 17 from being transmitted to the die 11 by radiation. Of course, the heat shield plate 20 also prevents relatively high temperature gas in the lower space 17 from flowing into the upper space 22 due to convection. Furthermore, a gas inlet 25 is connected to the lower space 17.
Since low-temperature gas is supplied from the lower space 17, a significant temperature rise in the lower space 17 is effectively suppressed. Of course, the heat insulating film 23 prevents the heat of the curing device 13 from being directly transmitted to the outer periphery of the heat shield plate 20.
In this way, the heat caused by the curing device 13 is effectively prevented from being transmitted to the die 11, so the die 11 is maintained at a low temperature, and the die 11 molds the liquid resin with high precision. Note that the crosslinked hardened region 16
The nitrogen gas flowing into the resin promotes crosslinking of the resin.

(Effect of the invention) As explained above, according to the invention, the die 1
By providing the heat insulating device 12 between the die 1 and the curing device 13, it is possible to effectively prevent the temperature of the die 11 from rising due to the heat of the curing device 13. Therefore, the distance between the die 11 and the curing device 13 can be shortened, and the time it takes for the optical fiber core 1 (strand 2 to which uncured resin is attached) to move from the die 11 to the crosslinking and curing region 16 can be shortened. Therefore, it becomes possible to reduce the amount of flow deformation of the resin, eliminate the influence of flow deformation as much as possible, and accurately set the size and shape of the coating layer 3 after curing using the die 11.

In other words, the size and shape of the coating layer 3 in the product state (cured state) are determined by the size and shape of the die hole 15 and the degree of flow deformation of the uncured resin (i.e., the size and shape of the die hole 15).
However, in the device according to the present invention, the minimum value of the travel time can be reduced, so at the device design stage, There are fewer restrictions on the size and shape of the die hole 15, and therefore, it becomes possible to set the size and shape of the die hole 15 to the most optimal value and shape in consideration of the accuracy of the coating layer 3, etc.

[Brief explanation of the drawing]

FIG. 1 is a schematic vertical cross-sectional view of an apparatus according to an embodiment, and FIG. 2 is a schematic cross-sectional view of a core wire manufactured by the apparatus shown in FIG. 1...Optical fiber core wire, 2...Element wire, 3...
Covering layer, 11... Dice, 12... Heat insulation device, 1
3... Curing device, 17... Lower space, 20... Heat shielding plate, 21... Passage hole, 22... Upper space, 2
3...Insulating film, 25...Gas inlet.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The material of the optical fiber core comprises an optical fiber element and an uncured resin for a coating layer attached to the periphery of the optical fiber, and the core material is directed vertically downward. A die for molding the outer periphery of the uncured resin into a predetermined size and shape is provided in the upper part of the processing section that moves to the processing section, and a curing device for curing the uncured resin is provided in the lower part of the processing section, A light source characterized in that a heat insulating device is provided in the middle of the processing section, and the heat insulating device is provided with a heat shielding plate having a partition wall structure located between an upper space on the die side and a lower space on the curing device side. Fiber core coating layer forming equipment. (2) A passage hole provided in the heat shielding plate for passing the strand assembly is provided so that the space between the inner periphery of the passage hole and the strand assembly allows the atmosphere to flow from the lower space to the upper space. The device according to claim 1, which is configured to form a regulating orifice. (3) The device according to claim 1 or 2, wherein the heat insulating device includes a heat insulating member between the heat shield plate and the curing device. (4) The device according to any one of claims 1 to 3, wherein the heat insulating device includes means for supplying cooling gas to the lower space.