JPS60208717A - Submarine optical cable and its manufacturing device - Google Patents

Abstract

PURPOSE:To improve various mechanical and electric characteristics and to increase reliability by forming a pressure-tight layer of plural coupled sectorial metallic pieces, and thus eliminating deviation between matching edges. CONSTITUTION:The pressure-tight layer 7 consists of three metallic pieces 7a, 7b, and 7c across slits 8 and 9, and they are coupled together. The pressure- tight layer raw material 10 forming said pressure-tight layer, on the other hand, consists of sectorial metallic pieces 10a, 10b, and 10c, which are each coupled together at one end. Therefore, the pressure-tight layer raw material 10 is manufactured by a conforming device and supplied to a pressure-tight layer former to form the pressure-tight layer 7 of an optical fiber unit 1 as shown by an alternate long and short dash line. Then, the seamless pressure-tight layer 7 is formed and deviation between matching edges is eliminated to improve various mechanical and electric characteristics, increasing the reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a particularly high-voltage submarine optical cable using optical fiber as a transmission medium and an apparatus for manufacturing the same.

[Background technology and its problems]

Communication channels that use low-loss optical fibers as the transmission medium can dramatically increase the amount of information transmitted, so using submarine optical cables to connect long distances has great economic benefits.

FIG. 1 shows an example of a cross-sectional structure proposed for such a submarine optical cable, in which 1 is an optical fiber unit, 2 is an optical fiber unit that protects the optical fiber unit 1 from high water pressure,
In addition, it is a metallic voltage-resistant layer that is also used as a power supply path, and this voltage-resistant layer 2 is divided into three fan-shaped divided pieces 2a, 2.
It consists of 2c and 2c aligned vertically.

3 indicates a compound filled in the pressure-resistant layer 2 to ensure watertightness.

4 is a tensile strength wire twisted around the outer periphery of the pressure-resistant layer 2, which applies tensile force to the submarine optical cable. 5 is a metal tube fixing the tensile strength wire 4, and 6 is an insulating layer made of plastic or the like.

Note that the outer periphery of the insulating layer 6 may be provided with an exterior covering to prevent damage to the cable, if necessary.

The structure of this submarine optical cable is particularly characterized by the three divided pieces 2a, 2b, and 2c that constitute the pressure-resistant layer 2.

In other words, the pressure-resistant layer 2 is made by vertically aligning the divided pieces 2a, 2b, and 2c manufactured by the cold drawing method, and then fixing them by wrapping with tape, etc., so that the thickness of the layer 2 allows sufficient light even under high water pressure. It has the advantage that it can be made thick enough to protect the fiber unit 1, and can also be used as a power supply path even when it becomes a long-distance transmission path.

However, there are drawbacks as shown below.

■ Since the materials of the divided pieces 2a, 2b, and 2c are formed by cold drawing, it is difficult to obtain long ones (5 km at most), so we manufactured submarine optical cables with a length of 50 km. If so, at least 9 locations, 3
Since the cable includes 277 connection points made of wood, it must be said that the reliability of submarine optical cables, which are ideally designed to be unconnected, is poor.

■ The pressure-resistant layer 2 formed by the divided pieces 2a, 2b, and 2c is easy to fall apart due to its wood quality, so when the cable is bent or twisted, the divided pieces 2a, 2b, and 2c behave in different ways. , including during manufacturing, each divided piece 2a
, 2b.

The seams of 2C tend to shift, making it difficult to configure the inside of the voltage-resistant layer 2 into a right circle. In the worst case, the optical fiber unit 1 may become wedged in the seam and breakage may occur.

Furthermore, since each divided piece 2a, 2b, and 2c is manufactured individually by drawing, the tensile strength of each piece is different.

According to actual measurements, the yield strength may differ by several percent,
There is a problem in that the above-mentioned disjointed behavior is further multiplied.

■ Compound 3 is put into the gap between the optical fiber unit 1 and the pressure-resistant layer 2 in order to provide watertightness, but this compound 3 is especially applied to the divided pieces 2 at the manufacturing stage.
It is easy to leak from the gaps between a, 2b, and 2c, and sufficient watertightness cannot be ensured.

■ Divided pieces 2a, 2 manufactured by cold drawing
Materials b and 2c are individually wrapped in drums and supplied to the production line, resulting in poor workability and poor space efficiency within the facility. Furthermore, the divided individual pieces 2a are drum-wound.

The lowest layer portions 2b and 2c may be crushed and deformed by the winding pressure, making it impossible to ensure the uniformity of the formed pressure-resistant layer 2.

[Purpose of the invention]

The purpose of this invention is to improve various problems without losing the advantages of submarine optical cables made of divided individual pieces. An object of the present invention is to provide a submarine optical cable that improves performance and is easy to manufacture, and an apparatus for manufacturing the same.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A submarine optical cable and an apparatus for manufacturing the same according to the present invention will be explained below based on the drawings.

FIG. 2 shows a cross-sectional structure of a submarine optical cable showing an embodiment of the present invention, and the same parts as in FIG. 1 are given the same symbols.

That is, the optical fiber unit 1. Pressure-resistant layer 7° compound (layer) 3. Tensile strength line4. Metal tube5. Insulating layer 6
This is a submarine optical cable whose main components are:

The pressure-resistant layer 7 of the present invention is made up of three metal pieces 7a, 7b, and 7c by slits 8.9, and is characterized in that these metal pieces are connected to each other.

That is, the inner periphery is cut at three places, but the outer periphery is made up of three individual metal pieces 7a and 7b.

Since 7c is connected, remarkable effects are exhibited in terms of manufacturing and properties, as will be described later.

FIG. 3 shows a pressure-resistant layer material 10 for forming the pressure-resistant layer 7 of the present invention, in which fan-shaped metal pieces 10a and 10b are shown.
, 10c are connected at one end.

This pressure-resistant layer material 1o is manufactured by feeding a base material of copper or aluminum to a continuous forming machine usually called a conformer.

The Funforma device, as known among those skilled in the art,
For example, it was developed by the UK Atomic Energy Company (UKAEA), and its detailed explanation will be omitted, but the supply base material that is sandwiched between the rotating wheel and shoe is continuously pushed out by frictional force, and the shape shown in Figure 3 is It is extruded and molded from an open-hole die.

Therefore, materials with fairly complex shapes can be manufactured with high dimensional accuracy, and even if the supplied base material is interrupted, seamless products can be manufactured continuously by supplying the next supplied base material to the conform device. This feature allows continuous molding of long objects.

Therefore, if the pressure-resistant layer material 10 shown in FIG. 3 is manufactured using a conforming device and then supplied to a pressure-resistant layer former to be described later to form the pressure-resistant layer 7 of the optical fiber/fiber unit 1 as shown by the dashed line, a long Since the pressure layer 7 can be made seamless in a long submarine optical cable, the drawbacks that occur in the conventional pressure layer 2 consisting of divided pieces 2a + 2b, 2C can be solved, and the mechanical strength of the submarine optical cable can be improved. This has the effect of improving electrical characteristics.

FIG. 4 shows the shape of a pressure-resistant layer material 11 showing another embodiment of the present invention. In this embodiment, individual metal pieces 11a,
1 lb and 11c are formed into a shape close to the final forming shape. Therefore, there are advantages in that the load on the pressure-resistant layer former is reduced, the inner periphery is easily filled with compound, etc., and there is little leakage (sagging) of the compound at that time.

FIG. 5 shows yet another pressure-resistant layer material 12, in which a circular relief hole 12d is provided at the inner joining portion (slit) of the individual metal pieces 12a, 12b, and 12c.

12e is formed.

In this embodiment, when the pressure layer 7 is formed by the pressure layer former, the relief hole 12d is formed.

12e absorbs the distortion or error of the abutting surfaces of the metal pieces 12a, 12b, 12c, so the metal pieces (12a, 12c)
This has the effect that the abutting surfaces of b and 12c) become tighter and the pressure resistance is strengthened.

Furthermore, since the thickness t of the connection region indicated by diagonal lines can be increased, the strength of the pressure-resistant layer 7 can be further increased.

In each of the above embodiments, a case has been described in which the metal pieces are formed of three metal pieces, but the number of metal pieces may be set to a plurality of three or more, particularly an odd number.

In this case as well, since the voltage-resistant layer 7 of the present invention is supplied to the voltage-resistant layer former in a state in which individual metal pieces are connected, there is no particular difficulty in manufacturing, and when the voltage-resistant layer 7 is constructed, The effect is that there is almost no misalignment of the seams. Furthermore, increasing the number of metal pieces has the characteristic that flexibility is added to the submarine optical cable.

FIG. 6 shows a schematic diagram of a submarine optical cable manufacturing apparatus according to the present invention. In this figure, 20 is an optical fiber unit supply that supplies the optical fiber unit 1, 21 is a base material supplier that supplies the base material of the pressure-resistant layer 7, and 22 is a material that molds the pressure-resistant layer material from the base material. The conforming device 23 is a processing device for cleaning, cooling, or drying the pressure-resistant layer material as required. Reference numeral 24 indicates a pressure-resistant layer former for forming the pressure-resistant layer 7 on the outer periphery of the optical fiber unit 1;
Compound 3 is then filled. 25 indicates a gathering machine for twisting the tensile strength wires 4 around the outer periphery of the pressure-resistant layer 7;
6 is a tensile strength wire 4 provided with another compound tank 26a.
is the set of dice.

27 is a metal tape supply that supplies the material for the metal tube 5, and 28 is a metal tape former that forms the vertically laid metal tape into a tube shape.

In the welding line, 28a is a welding machine, and 29 is a winding drum.

The submarine optical cable manufacturing apparatus of the present invention includes the pressure-resistant layer 7 that protects the optical fiber unit 1, the base material supply 21. Conform device 22. Since forming is performed using the pressure-resistant layer material that is continuously supplied via the processing device 23 as necessary, it is characterized in that long submarine optical cables can be manufactured continuously.

Moreover, since only one material is supplied to the pressure-resistant layer former 24, the forming mechanism is simpler than conventional ones, and there is less leakage of the filled compound, making maintenance and repair of the production line easier and easier. Increased efficiency. Since the molded connected individual pieces are supplied to the production line in a tandem manner, it is possible to eliminate the curling of the individual pieces when drum-wound and the dip in the winding pressure of the bottom layer.

〔Effect of the invention〕

As explained above, the submarine optical cable of the present invention can improve various problems of submarine optical cables that are divided into three individual pieces by forming the pressure-resistant layer from connected metal pieces.

That is, the variation in the elongation strength of the pressure layer over one cross section of the cable is extremely small, and since the individual metal pieces are connected to each other, there is almost no possibility that the joints will shift or open. Therefore, the mechanical and electrical properties of the submarine optical cable are uniform, and reliable cables can be manufactured.

In addition, since the individual metal pieces are connected, it is easy to form while leaving the mold pound inside.
Even if the distance to the pile tension line gathering die, which is the next process, is long, there is no risk of the pressure-resistant layer coming apart, so the compound can be filled in front of the gathering machine cage, simplifying the equipment. Furthermore, since the pressure-resistant layer material can be supplied from conforming devices installed in tandem on the production line, the material has many advantages such as almost no deformation of the material and smooth forming.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing an example of a conventional submarine optical cable, Fig. 2 is a cross-sectional view of a submarine optical cable showing an embodiment of the present invention, and Figs. 3, 4, and 5 are submarine optical cables of the present invention. A cross-sectional view showing an example of a pressure-resistant layer material that can be adopted for
The figure is a schematic diagram showing a manufacturing apparatus of the present invention. In the figure, 1 is an optical fiber unit, 3 is a compound, and 4 is an optical fiber unit.
is a tensile strength wire, 5 is a metal tube, 6 is an insulating layer, 7 is a pressure layer, 10, 11.12 is a pressure layer material, 21 is a base material supply, 22 is a conforming device, 23 is a processing device, 24 is a pressure layer Indicates forma. Figure 1 Figure 2 Figure 3 Role Figure 4 Figure 1]b Figure 5 Li Zb

Claims (2)

[Claims] (1) A submarine optical cable comprising at least an optical fiber unit and a pressure-resistant layer that protects the optical fiber unit, wherein the pressure-resistant layer is formed by molding a plurality of connected metal pieces in a fan shape. A submarine optical cable characterized by: (2) A base material supply that supplies the base material of the pressure-resistant layer, a Hunform device that extrudes and molds the connected metal pieces from the base material, and a pressure-resistant layer that covers the optical fiber unit with the connected metal pieces. A submarine optical cable manufacturing device characterized in that a pressure-resistant layer former to be formed is incorporated in tandem in a submarine optical cable manufacturing line.