JPS5968708A - Production of optical cable unit - Google Patents

Abstract

PURPOSE:To eliminate the clearance between cores and to improve watertightness in the stage of supplying plural optical fibers into a twisting mouthpiece by extruding a filler in such a way as to enclose the same and forcing the filler to enter the inside of the cores in the stage of reducing the diameter. CONSTITUTION:Plural optical fiber cores 7 are twisted by the revolution of a core supply machine and the rotation of an eye plate 20 driven by a motor 14 and are supplied to a twisting mouthpiece 21. A unit filler 8 is extruded and coated so as to enclose the cores 7 in this stage. The filler 8 enters the inside through the clearance between the cores 7 and fills fully the clearance between the cores 7 and the central fiber 1 in the stage of reducing the diameter of the cores 7 with the mouthpiece 21. Therefore the optical cable unit 22 having good watertightness without any clearance between the cores is thus obtd. as shown in the figure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a watertight optical cable unit.

An optical cable unit having a structure in which a plurality of optical fiber core wires twisted together around the outer periphery of a center line are embedded in a unit filler is being considered as an optical submarine cable unit.

However, conventionally, as shown in FIG. 1, around the centerline 1 having the centerline sheath 2 on the surface, and around the optical fiber 3 as shown in FIG. (sometimes) 4. A plurality of optical fiber cores 7 each having a gel-like filling layer 5 and a core coating 6 sequentially provided thereon are twisted together as shown in FIG.
It had a structure in which a unit filler 8 was extruded around its outer periphery.

However, in such a structure, since adjacent optical fiber core wires 7 are in contact with each other, unit filler material 8
During extrusion seeding, this unit filler 8 does not enter inside the layer formed by each party fiber core 7, and the center line @f1f
There is a problem that a void 9 is formed on the outer periphery of 2, and water runs through this void 9, resulting in poor watertightness.

An object of the present invention is to provide a method for manufacturing an optical cable unit that can improve watertightness.

In the method for manufacturing an optical cable unit according to the present invention, a plurality of optical fiber cores are positioned at intervals around the center line so that a required spacing exists between the cores, and each of the optical fibers is When supplying the core wires to the twisting base while rotating them around the center line and twisting them together, the optical fiber core wires are surrounded at positions where there are gaps between the optical fiber core wires. A unit filler is extruded on the outer periphery of the optical fiber to break it, and in the process of the unit filler being pulled out to the twisted white metal side and being reduced in diameter, the layers formed by these optical fiber cores are exposed through the gaps between the fiber cores of each party. The present invention is characterized in that the unit filler is moved inward, and the gap between the layer formed by each of the optical fiber cores and the center line is filled with the unit filler.

Embodiments of the present invention will be described in detail below with reference to the drawings.

4 to 86 show a first embodiment of the present invention. As shown in the figure, from the center line supply 10, the center line 1
is supplied to the extruder crosshead 11. Further, each of the optical fiber core wires 12 rotating on its own axis while revolving around the center line 1 redirects the optical fiber core wire 7 toward the extruder crosshead 11. The extruder cross rad 11 of this embodiment has a cylindrical Niraglu 1 inside the die 13.
4 is supported by a tapered cylindrical nipple holder 15, and this nipple holder 15 is rotatably supported by a bearing 16, and a gear 17 is attached to the outer end of this nipple holder 15. It is connected to a motor 19 via a drive gear 18, so that the batten 2o in the Niraguru 14 can be rotated via the Niraguru 14. The center line 1 fed into the crosshead 11 is the batten 2
The optical fibers 7 are passed through the center hole of 0, and the fibers 7 are spaced around the center line 1, and the fibers 7 are placed near the outer periphery of the batten 7 so that the required spacing exists between the fibers 7 of each optical fiber 7. Perform positioning through the hole. In this state, each fiber core 7 is twisted by the revolution of the core wire supply 12 and the rotation of the batten 2o, and is supplied to the twisted 90 gold 21 together with the center line 1. In the extruder crosshead 11, when there is a gap between the optical fiber cores 7 as shown in FIG.
A unit filler 8 is extruded into a pipe shape so as to enclose these optical fiber cores 7 all at once, and the phase is detected. The diameter of the unit filler 8 is gradually reduced in the process of being drawn into the twist cap 21, and a part of the unit filler 8 is inserted into the layer formed by these optical fibers 7 through the gaps between the optical fibers 7. Then, the gap between the layer formed by each optical fiber core wire 7 and the center line 1 is filled with a unit filler 8 as shown in FIG. In this way, an optical cable unit 22 with good watertightness as shown in FIG. 7 is obtained. The optical cable unit 22 is passed through a cooling tank 23 to be cooled, and a scraping machine 24 takes advantage of the edge, while a scraping machine 25 inspects the edge.

In the extruder crosshead 11, it is preferable to evacuate the inside of the Nilaglu 14 to further prevent the generation of voids. Further, it is preferable that the replacement cap 21 be heated in order to prevent the unit filling material 8 from cooling rapidly.

Furthermore, when the distance between the twisting cap 21 and the batten plate 20 is t1, the diameter of the core wire passing through the batten plate 20 is 5-2r, and the twisting pitch is P1, the core diameter of the twisted layer is 2R, r 2πR p It is convenient to position the fibers so as to satisfy the following relationship without disturbing the twisted state.

As the unit filler 8, for example, nylon, polyethylene, which is the same material as the core wire inspection 6, or ethylene-vinyl acetate copolymer, which has low viscosity and excellent filling properties in a molten state, is used. As the optical fiber core wire 7, a gel-like substance-filled optical fiber core wire is preferable because it has excellent stability and is advantageous in terms of elongation relaxation.

FIG. 8 shows a second embodiment of the present invention. In this embodiment, in the extruder cross head 11, the Niraglu 14
This shows an example in which only the batten 20 is rotated without being rotated. That is, the batten 20 is supported by a tapered cylindrical batten holder 26, this batten holder 26 is rotatably supported by a bearing 16, and this batten holder 2
A gear 17 is attached to the outer end of 6, and this gear 17 is connected to a motor 19 via a drive gear 6-18, so that the batten 20 can be rotated.

Even in this case, the same effects as in the first embodiment can be obtained.

Incidentally, the batten 20 can also be arranged on the fiber inlet side of the cross head 11 instead of being placed inside the cross head 11.

As explained above, in the method for manufacturing an optical cable unit according to the present invention, extrusion coating with the unit filler is performed when there is a gap between the optical fiber cores during the twisting process of the optical fiber cores. Therefore, by using the gaps between the optical fiber cores, the unit filler can be filled into the gaps inside the layers formed by these optical fiber cores, making it easy to manufacture optical cable units with excellent watertightness. be able to.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a conventional lateral center line, Fig. 2 is a cross-sectional view of an optical fiber core, Fig. 3 is a cross-sectional view of a conventional optical cable unit, and Fig. 4 is a cross-sectional view of a conventional optical cable unit. An explanatory diagram showing the manufacturing process of the optical cable unit, FIG. 5 is a vertical cross-sectional view of the vicinity of the extrusion crosshead of the first embodiment, and FIG. 6 is a diagram showing FIG. 5 A-A.
7 is a cross-sectional view taken along the line B-B' in FIG. 7... Optical fiber core wire, 8... Unit filler, 9... Gap, 10... Center line saglai, 11... Extruder cross head, 12... Core wire saglai, 1<,':,, 3... Tice, 14... Niraguru, 15... Niraguru 71 ・Holder, 16... Bearing, 17.18... Gear, 1
9... Motor, 20... Eye plate, 21... Twisting cap, 22... Optical cable unit.

Claims (1)

[Claims] A plurality of optical fiber cores are positioned at intervals around the centerline so that a required spacing exists between the cores, and each of the fiber cores is twisted while rotating around the centerline. When the optical fiber core wires are supplied to the base and twisted together, a unit filler is extruded and coated on the outer periphery so as to surround the optical fiber core wires at positions where there are gaps between the fiber core wires of each party, and the unit filler material is In the process of being drawn to the twisting cap side and being reduced in diameter, the unit filler is moved from the gap between the respective optical fiber cores to the inside of the layer formed by these optical fiber cores, A method for manufacturing an optical cable unit, characterized in that a gap between the layer formed by the fibers and the center line is filled with the unit filler.