JPS62196610A - Production of flat optical cable - Google Patents

Abstract

PURPOSE:To prevent a diaphragm between optical fiber cores from being broken owing to the united extrusion molding of a sheath and the dimension of a shape from being disturbed by previously preparing a thread-lie member having the shape of the section of the diaphragm between optical fiber cores, and arraying an optical fiber core sandwiching the thread-lie member. CONSTITUTION:The thread-like diaphragm 6 previously produced by extrusion molding or the like is wound around a feeding reel, the optical fiber cores 1 are entered into aggregate dies 7 together with tension members 2 and the tension members 2 are uniformly arrayed around each core. Side pressure members 3 are led into an aggregate die 8 together with the diaphragm 6, the cores 1 and the tension members 2 and these members are aligned with the prescribed positional relation on the back of the aggregate die 8. The aligned members are led into a die of an extrusion molding machine 9 and sheathed to complete an optical under carpet cable 11. Consequently, it is unnecessary to charge the diaphragm area with molding resin at the time of sheath extrusion molding and increase resin pressure for extrusion molding, so that the prescribed shape dimension of respective parts of the cable can be obtained.

Description

[Detailed Description of the Invention] [Summary] In order to stabilize the shape and dimensions of a flat optical cable and improve precision,
After the partition walls between the optical fiber cores are manufactured in advance, they are assembled together with the core wires and other components and sheathed, thereby making the shape and dimensions of the flat optical cable stable and highly accurate.

[Industrial application field]

The present invention relates to a flat optical cable, in particular, a synthetic fiber member with a small tension wheel and a steel wire that protects the optical fiber from pressing force are arranged in parallel around the optical fiber core, and a notch that can be vertically split is provided. Regarding the manufacturing method of flat optical cables, in recent years, FA and OA are mainly used in factories and offices.

Various types of automation and labor saving are being promoted, which are called CAD, CAM, FMS, POS, etc.

All of these technologies are information communications, or in other words, data highways and local area networks.

It is based on network technology such as public communications, and recently optical communication systems called optical data highways and optical local area networks using optical fibers have been increasingly used to cope with larger communication capacities and faster speeds. It's starting to look like this.

One of the reasons behind the use of optical communications is an attempt to reduce the increasing amount of cables by utilizing the large capacity, which is one of the characteristics of optical communications. Particularly in offices, etc., the aesthetics of the environment, changes in the layout of terminal equipment, installation of structures on walls and pillars are not easily permitted (in the case of tenant buildings), or cable conduits and racks are connected to existing cables. There is a need to take measures to deal with the fact that the facilities are full. In order to meet these demands, the most advanced technology currently available is a method in which a 50 cm square carpet is laid on the floor of an office, and a flat optical cable several inches thick is routed underneath. For this reason, there is a need for a thin and strong flat optical cable that will not protrude from the tile surface even when laid under a tile carpet. Furthermore, flat optical cables that are laid under carpets are made of multiple optical fiber cores and multiple steel wires arranged in parallel and covered with insulation such as synthetic fibers, making it difficult to separate them into single-core cords. Therefore, a multi-connector is required to connect to the device, and it is weak against tension and pressure forces, and there is a risk of damage if it is laid under a carpet. Therefore, a flat optical cable that is resistant to tension and pressure forces and can be split easily is used. There is a strong demand for the development of

[Conventional technology]

Figure 4 is a schematic cross-sectional view of a conventional flat optical cable.
at is a structure in which two optical fibers and two steel wires are closely connected in parallel, (b) is a structure in which two optical fibers and one steel wire are separated and arranged in parallel, and (c> is a structure in which two optical fibers and a steel wire are arranged in parallel. It has a structure in which two wires are separated and placed in parallel.

FIG. 4(a) shows two optical fiber cores 45 and a steel lj
[Place the two 46 and the optical fiber core 45 in the center,
Steel wires 46 are closely attached to both sides in parallel, and a sheath 47 (sheath) made of synthetic resin, for example, vinyl chloride, etc. is molded to cover the wires.

FIG. 4(b) shows two optical fiber core wires 45 and a steel wire 4.
6 is placed in a sheath 47 (sheath) made of synthetic resin, such as vinyl chloride, with the steel wire 46 in the center and optical fiber cores 45 arranged in parallel at both ends with a slight interval between them. It is coated and molded 4 Figure 4 (cl is two optical fiber cores 45 and steel @ 4
6 are arranged in parallel with an optical fiber core 45 in the center with a slight spacing between them, and with steel wires 46 arranged in parallel with a slight spacing on both sides, they are made of synthetic resin such as vinyl chloride. It is coated and molded with an outer cover 47 made of, etc.

FIG. 5 is a detailed sectional view of FIG. 4(c). This is light 7
After assembling the Aiva core wire l, tension member 2 (tensile strength fiber such as aromatic aramid fiber), and lateral pressure member 3 (steel wire, etc.) that prevents vertical forces from directly reaching the core wire, sheath 4 is applied. It has a similar structure.

FIG. 6 is a perspective view illustrating an example of a conventional flat optical cable.

The figure shows that when connecting the flat optical cable 1' explained in FIG. A multi-connector 2'' is connected to the other end of a plurality of single-fiber optical cords 3' with a single-fiber connector 4' attached to one end, and the multi-connector 2 is connected to the end of the flat optical cable 1. This structure is such that the single-core connector 4' is connected to the optical transmission device 8' after being connected to the ! Luna connector 2' attached to the unit.

The conventional flat optical cable described above requires a pair of multi-connectors to connect the flat optical cable to a device, which requires a lot of man-hours and is expensive.
There was a problem that the wires were weak against tension and pressure and could be damaged if placed under the carpet.

In order to solve these problems, the present applicant filed a patent application in 1983.
No. 0-147923 proposes a flat optical couple that can be divided into single optical fibers.

FIG. 7 is a diagram for explaining the above-mentioned flat optical cable.
(a) is a front view of the flat cable, (b) is a perspective view of the flat cable torn apart, and (C) is a perspective view of the optical fiber core. Parts equivalent to those in Figure 5 are given the same reference numerals. .

Figure 1 (at is 2) in which a synthetic fiber member 9 (equivalent to Tenshi, Nmenba 2VC) such as aromatic polyamide fiber with small tensile stretch (product name: KUBU Y->) is arranged around the outer periphery of Hikari 7 AIPA core wire 1. The optical fiber cores 1 are arranged in parallel at a predetermined distance in the center, and steel wires (n-pressure members) protect the optical fiber cores 1 from damage from pressing force (load) on both sides.
3 are lined up in parallel at a predetermined interval and are covered with a jacket 4 made of synthetic resin, such as vinyl chloride, and the thickness is about 2 waa. Cuts 10 are provided at opposing positions on the upper and lower surfaces of the jacket 4 between the optical fiber core 1 and the steel wire 3 to allow vertical tearing.

Cut the flat optical cable explained in Figure 7 (&) with a cut of 10
By tearing along the two central optical fibers 1, the two central optical fibers 1 are divided into single-core optical cord-like 10' as shown in FIG. 7(b).

FIG. 7(e) is a block diagram of the optical fiber core 1, in which the optical fiber 51 is coated with a primary coat 52 as a buffer layer, and a secondary coat 53 is applied on the primary coat 52. Its outer diameter is approximately 0.9111-.

FIG. 8 is a plan view illustrating an example of application of this flat optical cable, in which the same parts as in FIG. 7 are given the same reference numerals.

In the figure, when the flat optical cable is torn along the notch 10, the two central optical fiber cores 1 are divided into single-fiber optical cord-like 10', and each single-fiber optical fiber 10' has a single core. A connector 16' may be attached to connect to an optical transmission electrical equipment (not shown). In this case steel wire 30
The optical fiber core 1 is not limited to two, but may be two or more.

[Problem that the invention seeks to solve]

When sheath extrusion molding is performed on the flat optical cable shown in Figure 7, the partition wall between the core wires 1 and 1 is narrow as shown in Figure 9, so the resin does not go around and the wall is torn (see Figure 9). part 5). Furthermore, if the resin pressure is increased to allow the resin to go around, the sheath portion other than the partition wall becomes thicker, as shown in FIG. 10, and there is a manufacturing problem in that it is difficult to obtain a predetermined size and shape. Note that if the bulkhead is made larger, the above problem will not occur, but in order to move the core wire further away from the cable center, when one cable is bent in a plane, the compressive force applied to the core wire (the center core inside the cable center) wire), the tensile force (core wires outside the cable center) further increases,
High-quality transmission characteristics may not be obtained, or in the worst case, the core wire may break. For these reasons, it is necessary to keep the dimensions (thickness) of the bulkheads of the core wires to the minimum required size (thickness) to maintain the optical code shape after the cable is split, and to maintain the specified shape and dimensions without tearing the bulkheads. There is a need for a cable manufacturing method that yields the following.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, a filamentous member having the cross-sectional shape of the partition between the optical fibers is prepared in advance, and the filamentous member is sandwiched between the optical fiber cores and The wires are arranged and then integrally formed with a sheath.

[Effect]

Since the filament-like member corresponding to the partition wall between the core wires of the optical cable is prepared in advance, there is no need to fill this partition area with molding resin during sheath extrusion molding, so the wall does not tear, and the extrusion molding resin Since there is no need to increase the pressure, the shapes and dimensions of each part of the cable can be kept as specified.

〔Example〕

Embodiments of the present invention will be explained below with reference to the drawings. FIG. 1 shows an embodiment of the invention. In the figure, reference numeral 6 denotes a filament-like partition wall manufactured in advance by extrusion molding or the like, and the material is the same or equivalent plastic as that of the sheath. A perspective view of this partition wall 6 is shown in FIG. The bulkhead 6 is wound onto a supply reel. Reference numerals 1 and 1 denote optical fiber cores, which enter a gathering die 7 together with tension members (tensile strength fibers) 2, and tension members are arranged evenly around the core.

The cluster die 8 has the aforementioned partition wall 6. Core wire 1. In addition to the tension member 2, an expansion member 3 is guided, and after the assembled die 8, these members are aligned in a predetermined positional relationship. The aligned members enter a die of an extrusion molding machine 9, are sheathed, and the optical undercarpet cable 11 is completed. Although not shown in the drawings, it actually passes through a cooling tank, is dried, and is wound up. Partition wall 2 T Core wire 1-1' e Tension member 2. @
The supply drum of the pressure member 3 is provided with a moderate back tension (several tens to hundreds of grams). Although FIG. 1 shows a two-core production line, it goes without saying that the present invention can be carried out in cables with three or more cores by arranging bulkhead supply reels between the core supply reels. .

The cross-sectional shape of the partition wall manufactured in advance is shown in FIG.
The position it occupies in the completed cable as shown in K,
Depending on the area, various shapes of variegation cables can be considered as shown in Figures 2 (at to (c)).Fifth, K is a cable that facilitates dividing the completed cable into individual optical cords (core wires). As shown in Fig. 2(d)k, a longitudinally continuous gap 12 may be provided inside the partition wall.If the partition wall is made of the same material as the sheath, it will be completely fused to the sheath after the sheath is extruded. In addition, even if a different material is used, it will essentially adhere to the sheath, so there is no difference in function and handling compared to a cable whose sheath is extruded, including the bulkhead. .

As a modification or application, although not shown, it is conceivable to use a pre-manufactured partition wall also for the partition wall portion between the core wire and the side pressure member. This is particularly effective when the distance between the core wire and the lateral pressure member is narrow.

[Effects of the Invention] According to the present invention, breakage of the fiber separation wall and disturbance of shape and dimensions due to integral extrusion of the sheath are prevented.
It is possible to provide a thin cable that is suitable for an optical undercarpet cable, has extremely high dimensional stability, and has high quality transmission characteristics. Furthermore, when manufacturing extrusion molds, the design was designed by omitting the partition wall, which requires extremely precise dimensional accuracy (particularly because the dimensional relationship between the partition wall and other parts is affected by resin pressure). ．． Since it can be manufactured, it is possible to significantly reduce man-hours and costs.

[Brief explanation of drawings]

Fig. 1 is a detailed explanatory diagram of the present invention, Fig. 2 (al to (c) is an explanatory diagram of a thread-like member equivalent to a partition wall,
Figure 3 (at to (c)) shows the completed flat optical cable;
8 are diagrams for explaining conventional flat optical cables, FIG. 9 is an example of a defect produced using the conventional method, and FIG. 10 is an example of a defect produced using the conventional method. In the figure, 1 is an optical fiber core (it 0.4 to 0.9 ff), 2 is a tensile strength member (tensile strength T/A fiber such as aromatic aramid fiber), and 3 is a lateral pressure member (steel). wire, etc.), 4 is a sheath. 8 figure t”1lait hawk i arxaF
l structure'e 敞ri＊+ll structurez (iL)
(b)
(C) rMr side view of conventional flat optical cable Figure 6

Claims (2)

[Claims] (1) A thread-like member having the cross-sectional shape of a partition between optical fiber cores is prepared in advance, the thread-like member is sandwiched to align and gather the optical fibers, and then an outer jacket is formed and integrally molded. A method for manufacturing a flat optical cable. (2) The thread-like member is made of the same material as the outer cover,
2. The method of manufacturing a flat optical cable according to claim 1, wherein the outer sheath and the filamentous member are fused together.