JPH0253763B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a submarine repeater used in optical communications. Currently, submarine communication systems using coaxial cables are widely used for multiplex communication between continents or between islands.

Since the repeaters used in this submarine communication system are installed on the seabed, they are housed in a watertight, pressure-resistant repeater housing.

The recent development of optical communication technology has already seen the emergence of so-called optical fibers, which have transmission characteristics superior to coaxial cables, and it is clear that optical communication systems will be used in place of coaxial cable communication.

At both the front and rear ends of a submarine repeater, the end of the communication cable, the so-called tail cable, must be connected to the repeater unit's input/output cable, but in conventional coaxial cable systems, the copper conductor of the cable is brazed. PE insulators are connected using a molding method, etc., but since there is only one cable, the connection part is formed relatively small, and it is attached to the front and rear ends of the watertight, pressure-resistant structure together with the repeater. It is accommodated.

Fig. 1 shows a partially sectional side view of the accommodation structure of this connection part, where 1 is a watertight, pressure-resistant casing that houses the repeater unit 2, and 3 is a welded etc. at both ends of the casing 1. 4 is a tail cable of an input (output) connection cable; 5 is a tail cable of a terminal of a submarine coaxial cable 6;
7 is a connection part between cable 4 and cable 5, 8 is a joint ring, 9 is a cable retaining fitting, 10
is a cable housing part filled with insulating oil and at a pressure that is balanced with the external pressure (water pressure).

Since the connecting portion 7 only electrically connects the corresponding core wires of the cables 4 and 5, it is constructed relatively small, and for example, in the case of the current CS-36M system, it has a diameter of about 20 mm. Approximately 30mm in length,
It is accommodated together with the front and rear tail cables 4 and 5 in a narrow space of a cable accommodation section 10 within the joint ring as shown.

In a submarine repeater using optical fiber cables, both 4 and 5 correspond to optical fiber cables, but in this case, the connecting portion 7 of both cables is an optical connection instead of a conductive connection.

In order to prevent changes in transmission characteristics etc. due to seawater pressure being applied to the optical fiber cable, the optical fiber cable 11,
11' (the figure shows an example of cables accommodating two cables each) and a pressure-resistant metal pipe 13 whose periphery is coated with polyethylene 12, 12' to protect it from external pressure.
In order to properly align the axis of the optical fiber core wires 11 and 11' housed in the optical fiber core wire 11, 11' using a jig and tools and optically connect them by fusion or the like. For this purpose, it must be pulled out quite long (for example, more than 500 mm on one side). In addition, the optical fiber core wires 11 and 11' that have been connected are connected again to 13 and 1 by appropriate means to withstand voltage.
It is necessary to protect and reinforce the space between 3' and 12' and 12', and to accommodate the long optical fiber core mentioned above without applying excessive force. The length of the cable connection part is significantly longer (200 mm or more) compared to the coaxial cable method, and the flexibility is reduced due to the protection and reinforcement of the optical fiber core, making it impossible to accommodate it in the space of the conventional cable storage part. . Therefore, the diameter of this space must be made significantly larger than the diameter of the casing, or the length in the axial direction must be increased, resulting in an extremely large repeater body.

The present invention provides an optical submarine repeater having a structure that avoids the above-mentioned drawbacks.

In the present invention, a sealed end plate that seals the end face of a pressure-resistant casing of a repeater and has a sealed lead-out portion for the optical fiber core from the repeater, and a cable retaining portion facing the sealed end plate are provided. a sealed pressure-resistant container extending from the pressure-resistant housing and integrally connected; and a seal that seals the side of the sealed pressure-resistant container facing the cable retention part and through which the pressure-resistant cable from the cable retention part is introduced. a pressure-resistant bulkhead having an introduction part, and the optical fiber core led out from the sealed lead-out part of the sealed end plate into the sealed pressure-resistant container, and the pressure-resistant cable introduced through the sealed introduction part of the pressure-resistant partition. This object is achieved by accommodating the optical fibers drawn out from inside the fiber optics and a connecting portion that optically connects both the optical fibers drawn out and introduced.

Unlike the conventional method, by providing a sealed pressure-resistant container that forms a sealed space between the sealed end plate and the cable stopper, there is no need for a means to protect the outer periphery of the optical fiber core and the connecting portion contained within the sealed space. Since the optical fiber can be accommodated in an exposed state, a considerably long optical fiber can be accommodated even in a narrow space.

The gist of the present invention will be specifically explained below with reference to illustrated examples.

FIG. 3 shows an embodiment of the present invention in a sectional view of a main part, and the same reference numerals as in FIGS. 1 and 2 indicate the same objects.

A space 14 corresponding to a conventional cable accommodating portion (corresponding to 10 in FIG. 1) adjacent to an end plate 3 that seals both ends (only one side is shown in the figure) of a pressure-resistant case 1 that accommodates a repeater unit 2 is provided. It is completely separated from the cable retaining fitting 9 by a pressure-resistant cover 15 which is a pressure-resistant bulkhead on the side of the sealed pressure-resistant container facing the cable retaining portion formed by this space 14 . For this reason, the cover 15 is fitted with a suitable packing 16,
It is screwed to the tip of the joint ring 8, and the flange 17 at the tip of the cable retaining fitting presses the periphery of the cover plate 15 and is tightened by the tightening ring 18 to the threaded portion at the tip of the joint ring 8. They are screwed together to maintain a pressure-resistant sealing function against external pressure. As described above, a sealed pressure-resistant container composed of the joint ring 8 extending from the pressure-resistant case 1 is integrated between the sealed end plate 3 that seals the end face of the pressure-resistant case 1 and the cable retention part at the tip. Connections will be formed continuously. A cable seal introduction part 19 is provided in the center of the cover plate 15, and the optical fiber core 1 extracted from the protection (envelopment) of the cable is provided.
1' and, at the same time, the optical fiber core 11 from the sealed lead-out part 20 of the pressure-resistant end plate 3 are drawn out long to the outside in advance and joined using a jig to properly align the optical axis at the joint part 21. Together with this, it is rolled up and housed in a space 14, that is, a sealed pressure-resistant container. Optical fiber core wires, which are housed after removing the pressure-resistant pipes and jackets that make up the cable, are highly flexible, and even fairly long cables can be accommodated in a sealed pressure-resistant container in a narrow space without any problems, so the repeater itself It can be manufactured in a small size.

In the optical fiber accommodating portion of the present invention, a portion corresponding to a conventional joint ring is made into a sealed pressure-tight container with a watertight and pressure-tight structure, thereby securing a space corresponding to the inner diameter of the pressure-tight casing. This allows the optical fiber to be wound and accommodated with a sufficient bending diameter, so that optical transmission characteristics are not impaired. In addition, the work of housing and fixing the optical fiber through the space opening becomes easier and the work efficiency is improved.
Furthermore, it has a simple structure, is practical, and has remarkable effects.

The present invention is not limited to the illustrated embodiment, but can be modified in various ways within the scope of the claims, particularly as a sealing means for a sealed pressure-resistant container.

[Brief explanation of drawings]

Figure 1 shows a partially sectional side view of an example of a conventional submarine repeater using coaxial cables, Figure 2 shows a schematic diagram of the connection of optical fiber cables used in optical communications, and Figure 3 shows a schematic diagram of the connection of optical fiber cables used in optical communications. 1 is a side view showing a cross section of essential parts of an optical communication submarine repeater according to the present invention. In the figure, 1 is a pressure-resistant case that houses the repeater unit 2, 3 is a sealed end plate, 8 is a joint ring, 9 is a cable stopper, 10 is a cable accommodation section, 14 is a sealed pressure-resistant container, and 15 is its cover. board, 1
8 indicates a tightening ring.

Claims (1)

[Claims] 1. The end face of the pressure-resistant housing of the repeater is sealed, and the above-mentioned pressure-resistant structure is installed between the sealed end plate having a sealed lead-out portion of the optical fiber core from the repeater and the cable retaining portion opposite to the sealed end plate. It has a sealed pressure-resistant container that extends from the casing and is integrally and continuously connected, and a sealed introduction part that seals the side of the sealed pressure-resistant container facing the cable retention part and through which the pressure-resistant cable from the cable retention part is introduced. It consists of a pressure-resistant bulkhead,
The optical fiber core led out from the sealed lead-out part of the sealed end plate and the optical fiber core led out from the inside of the pressure-resistant cable introduced through the sealed lead-out part of the pressure-resistant bulkhead into the sealed pressure vessel. and,
An optical submarine repeater characterized by accommodating a connection part that optically connects both the optical fiber core wires led in and out.