JPH09133817A - Optical cable guide-in part structure of optical submarine repeater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for a sleeve for inserting a hollow pipe by contracting the hollow pipe along the center axis and airtightly sealing it. SOLUTION: A buffer member is inserted into the hollow pipe 6 in which an optical fiber is arranged and the hollow pipe 6 corresponding to the position of the inserted buffer member is contracted radially to put the optical fiber 1 and hollow pipe inside in airtight structure. The hollow pipe 6 and the inside of an airtight cone 12 are molded out of the same resin, etc., with a cable jacket 7 to form airtight structure between the airtight cone 12 and hollow pipe 6. The tapered part of the airtight cone 12 is pressed against the tapered part of a pressure-tight cover 13 with screws to obtain airtightness between the side of the sea bottom and the optical submarine repeater.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical submarine repeater, and more particularly to a structure of an optical cable introduction part for introducing an optical fiber into the optical submarine repeater and keeping the inside of the optical submarine repeater airtight.

[0001]

2. Description of the Related Art As shown in FIG. 3, a conventional optical submarine repeater 18 has a case part comprising a pressure-resistant cylinder 17 and a pressure-resistant cover 13, and the optical cable 16 is inserted into the pressure-resistant cover 13 on the side face via an optical cable introduction part 15. Is introduced.

Next, a structure of an optical cable introducing portion of a conventional optical submarine repeater will be described with reference to the configuration diagram of FIG.

[0003] In FIG. 2, an optical fiber 1 is formed by covering a thin silica glass wire having a diameter of about 125 μm comprising a core part and a clad part with a plastic jacket having a thickness of about 100 μm. On the device side of the optical cable introduction part,
The optical fiber 1 protrudes from the hollow pipe 6, and a solder layer 2 is formed outside the optical fiber 1 in a cylindrical shape. A cylindrical hollow tube 4 made of Kovar or the like is arranged outside the solder layer 2 and the hollow pipe 6 near the solder layer 2. The space between the optical fiber 1 and the solder layer 2 has an airtight sealing structure.

[0004] A sleeve 5 is disposed on the outer periphery of the cylindrical hollow tube 4 and the hollow pipe 6 introduced from the sea floor side, and a brazing portion 10 hermetically seals the hollow pipe and the sleeve 5. A sleeve 5 is provided between the cylindrical hollow tube 4 and the sleeve 5.
The hermetic sealing structure is formed by the O-ring 3 provided inside the. A resin layer 9 made of polyethylene or the like is formed between the airtight cone 12 and the outside of the sleeve 5 to form an airtight sealing structure. The resin layer 9 is integrally connected to the sea bottom-side cable coating 7 via the connection mold portion 8 and also serves to insulate the electricity flowing through the hollow pipe 6.

The hermetically sealed cone 12 whose inside is hermetically sealed as described above has the taper portion of the pressure-resistant cover 13 of the optical submarine repeater and the taper portion of the hermetic cone 12 set screw 11.
By crimping, the cable introduction part of the optical submarine repeater is hermetically sealed.

Next, the hermetic sealing action in the hollow cylindrical tube 4 will be described. The optical fiber 1 covered with the solder layer 2 has a sheath removed in advance, and a surface treatment for improving the adhesion to the solder layer 2 such as gold plating is performed on the quartz glass surface. The inner surface of the cylindrical hollow tube 4 is also coated with a solder layer 2 of gold plating or the like in advance.
Surface treatment to improve adhesion. First, when the components are arranged in a state where the solder layer 2 is melted, and then the solder layer 2 is solidified, the solder layer 2 thermally contracts during the solidification. Then, an airtight sealing structure is formed between the solder layer 2 and the optical fiber 1 by the adhesive force between the solder layer 2 and the hollow tube 4 which has been subjected to gold plating in advance, and between the solder layer 2 and the optical fiber 1.

[0007]

However, in the above-described conventional cable introduction structure for an optical submarine repeater, the optical fiber 1
Was sealed airtight with the solder layer 2, so that the solder layer 2
This is a pre-processing step for forming a hollow tube, and further requires a cylindrical hollow tube 4 for adhering solder and a sleeve 5 for inserting the hollow tube 4. Further, in order to airtightly connect the hollow pipe 6 and the sleeve 5 from the seabed side with high strength, a step of brazing the connection portion has occurred. In addition, there is a problem that the hollow pipe 6 at the connection portion is annealed due to the influence of heat at the time of brazing, and the strength of the hollow pipe is reduced.

[0008] The object of the present invention is to solve these problems,
An object of the present invention is to provide a cable introduction structure of an optical submarine repeater that has a small number of parts, can reduce an assembling process, and has no deterioration in quality.

[0009]

In the optical cable introduction structure for an optical submarine repeater of the present invention, a buffer member is inserted into a hollow pipe in which an optical fiber is disposed, and corresponds to the position of the inserted buffer member. The optical fiber and the inside of the hollow pipe are made airtight by shrink-molding the hollow pipe in the radial direction. The hollow pipe and the inside of the airtight cone are molded with, for example, resin or the like, which is the same material as the cable coating, so that the space between the airtight cone and the hollow pipe is airtight. further,
The tapered portion of the hermetic cone is pressure-bonded to the tapered portion of the pressure-resistant cover of the optical submarine repeater with a set screw, so that the space between the submarine side and the optical submarine repeater is airtight.

[0010]

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

FIG. 1 is a sectional view of an embodiment of an optical cable introduction structure for an optical submarine repeater according to the present invention.

First, the structure will be described with reference to FIG. The hollow pipe 6 in which the optical fiber 1 is disposed is introduced into the pressure-resistant cover 13. The optical fiber 1 disposed in the hollow pipe 6 is the same as the optical fiber 1 in the prior art, and is formed by covering a thin quartz glass wire having a diameter of about 125 μm with a plastic jacket having a thickness of about 100 μm. Up to about 12 optical fibers can be arranged in the hollow pipe 6.

The hollow pipe 6 has a tip portion thinner than other portions. In this portion of the hollow pipe 6, a buffer layer 14 is provided between the optical fiber 1 and the inner surface of the hollow pipe 6. , Forming a hermetically sealed structure. If the hermetic sealing is sufficient, it is not necessary to form the entire buffer layer 14 forming area in the hollow pipe 6 thin. The hollow pipe is made of a material such as copper formed in a cylindrical shape and easily plastically deformed, and has an inner diameter of about 2 mm and an outer diameter of about 4 mm. For the buffer member constituting the buffer layer 14, rubbers such as silicon rubber, or a material having a large displacement in an elastic range such as a resin is used. Also, solder can be used. When solder is used, the optical fiber is plated with gold as in the conventional case.

A mold layer 9 is formed on the outer periphery of the hollow pipe 6 by, for example, polyethylene resin, and an airtight cone 12 is formed on the outer periphery of the mold layer 9. The polyethylene resin of the mold layer 9 is in close contact with the cable coating 7 also made of polyethylene resin. The resin of the mold layer 9 is not limited to polyethylene. However, a material that can be integrally formed with the material of the cable coating 7 is desirable. The inner diameter of the hermetic cone 12 is about 50 mm.
The thickness is about 10 mm.

The hermetic cone 12 whose inside is hermetically sealed,
The optical submarine repeater is pressure-bonded to a tapered portion formed in a through hole of the pressure-resistant cover 13 (thickness: about 50 mm) by a set screw 11 disposed on the seabed side (outside) of the pressure-resistant cover 13, and is provided. Hermetically seal the cable inlet of the container. Although the above-mentioned hermetic cone 12, pressure-resistant cover 13, and set screw 11 are made of beryllium / copper alloy, stainless steel or the like can be used.

Next, the configuration method of the present invention will be described. First, the cable coating 7 is removed from the optical cable by a predetermined length. Next, at the center of the hollow portion of the airtight cone 12, the hollow pipe 6 from which the cable coating 7 has been removed is centered and arranged. This can be easily performed using a predetermined mold. However, before this, it is desirable to roughen the surface of the hollow pipe 6, the surface of the hollow portion of the airtight cone 12, or both surface portions. Specifically, there is a method of oxidizing these surfaces with an oxidizing material.

Polyethylene is poured between the airtight cone 12 and the hollow pipe 6 arranged as described above, and the mold layer 9 is formed.
To form Due to the above roughening, polyethylene is formed in close contact with the hermetic cone 12 and the hollow pipe 6. On this occasion,
The portion of the hollow pipe 6 to be contracted later is set so as to protrude from the airtight cone 12. Molding is performed so that the cable coating 7 of the optical cable and the mold layer 9 are in close contact and integrated. In the steps so far, it is better not to insert the optical fiber 1 into the hollow pipe 6.

Next, the optical fiber 1 is passed through a hole formed in a predetermined portion of the buffer layer 14, and these are inserted into the hollow pipe 6 so that the buffer layer 14 is located at the portion of the hollow pipe 6 protruding from the hermetic cone 12. Set in 6. After being configured as described above, this portion is contracted by a mold or the like to form a hollow pipe contracted portion 6a. Due to the contraction of the hollow pipe 6, the buffer layer 14 generates elastic stress, and a self-tension force is applied between the outer jacket of the optical fiber 1 and the buffer layer 14, and between the buffer layer 14 and the inner peripheral surface of the hollow pipe contracted portion 6a. A repulsive force is generated to form a hermetic sealing structure.

Finally, the tapered portion of the hermetic cone 12 whose inside is hermetically sealed and the tapered portion formed in the through hole of the pressure-resistant cover 13 of the optical submarine repeater are arranged outside the pressure-resistant cover 13. It is crimped by the set screw 11 to hermetically seal the cable introduction part of the optical submarine repeater.

[0020]

As described above, according to the present invention, the optical fiber, the buffer layer, and the hollow pipe are concentrically arranged, and the hollow pipe is contracted in the direction of the central axis to form a hermetic seal. The need for a hollow tube and a sleeve for inserting the hollow tube is eliminated. In addition, since it is not necessary to use a solder layer, a pretreatment step for this is not required.

Further, according to the present invention, since the outside of the optical fiber is hermetically sealed by using a hollow pipe from the seabed side, it is not necessary to perform the conventional brazing of the connection, so that the process can be further simplified, and the brazing is performed. In this case, there is no possibility of the strength of the hollow pipe being deteriorated due to the influence of heat when the heat treatment is performed.

As described above, it is possible to reduce the number of parts of the optical cable introducing portion, shorten the working process, and improve the quality.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of an optical cable introduction part of an optical submarine repeater of the present invention.

FIG. 2 is a cross-sectional view of one embodiment of an optical cable introduction portion of a conventional optical submarine repeater.

FIG. 3 is a structural sectional view of an optical submarine repeater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Solder layer 3 O-ring 4 Hollow tube 5 Sleeve 6 Hollow pipe 6a Hollow pipe shrinking part 7 Cable coating 8 Connection molding part 9 Resin layer 10 Brazing part 11 Set screw 12 Airtight cone 13 Pressure-resistant cover 14 Buffer layer 15 Optical cable introduction section 16 Optical cable 17 Pressure-resistant cylinder 18 Optical submarine repeater

Claims (6)

[Claims] 1. A hollow pipe for holding an optical fiber therein, a mold layer formed on an outer peripheral portion of the hollow pipe,
An optical submarine relay equipped with an airtight cone formed on the outer peripheral portion of the mold layer and a screw for crimping the taper portion of the airtight cone to the taper portion of the pressure-resistant cover of the optical submarine repeater to hermetically seal the optical submarine repeater. In the optical cable introduction part structure of the container, a buffer layer is arranged between the optical fiber and the hollow pipe, and a part or all of the hollow pipe portion in which the buffer layer is arranged is formed thinner than the diameter of the other hollow pipe portion. The structure of the optical cable introduction part of the optical submarine repeater characterized in that 2. The thinly formed portion of the hollow pipe portion is:
2. The optical cable introduction section structure of an optical submarine repeater according to claim 1, wherein the optical cable introduction section is mainly located on the device side. 3. The optical cable introduction part structure of an optical submarine repeater according to claim 1, wherein the buffer layer is made of an elastic material. 4. The optical cable introduction part structure for an optical submarine repeater according to claim 1, wherein the outer peripheral surface of the hollow pipe and / or the inner peripheral surface of the hermetic cone are roughened. 5. The optical cable introduction part structure of an optical submarine repeater according to claim 1, wherein a plurality of optical fibers are arranged in the hollow pipe. 6. The optical cable introduction part structure of an optical submarine repeater according to claim 1, wherein the mold layer and the optical cable covering layer are integrally formed.