JPS59119308A - Housing for optical submarine repeater - Google Patents

Abstract

PURPOSE:To improve reliability with simple structure by charging moisture-proof oil and providing an accumulator for hydraulic pressure absorption in the storage chamber of an optical fiber connection part formed between two end surface plates provided airtightly at either end part of a cylindrical barrel body. CONSTITUTION:Three partitioned chambers, i.e. a center partitioned chamber 4 between the left and right internal end surface plates 12, 12, external end plate 11 and the internal end surface plates 12 are formed airtightly in a housing 3. The storage chamber 5 of the optical fiber connection part is charged with the moisture-proof oil, e.g. polybutene and the accumulator 20 made of a rubber tube charged with air is provided therein. The accumulator 20 contracts or expands itself when the moisture-proof oil contracts or expands owing to fluctuations of ambient temperature to hold the inside of the storage chamber 5 below specific pressure. Thus, the reliability of the housing is improved with the simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a casing for an optical submarine repeater, and particularly to the structure of a housing chamber for an optical fiber connection part.

(2) Background of the Technology The casing for an optical submarine repeater includes, in addition to the repeater accommodation chamber, a accommodation chamber for the connection portion of the optical fiber cable. This optical fiber connection housing chamber is required to be highly airtight, similar to the repeater housing chamber. In addition, in the optical fiber connection chamber,
In order to prevent optical fibers from deteriorating due to seawater penetration, they are usually filled with moisture-proof oil (or insulating oil).However, conventional housing structures have the following problems:
Countermeasures are required.

(3) Prior art and problems In the conventional optical submarine repeater case, end plates are airtightly provided at both ends of a cylindrical body to form a repeater housing chamber, and optical fibers are connected to the end plates of the case. It has a structure with a storage room. However, with this structure, the repeater housing chamber and the optical fiber connection housing chamber must be hermetically sealed separately, there are many sealing points, the structure is complex, and airtightness is not guaranteed. There is a problem that high reliability cannot be obtained.

In addition, the moisture-proof oil filled in the optical fiber connection chamber generally has a large coefficient of thermal expansion, and furthermore, the moisture-proof oil is subject to environmental changes.
Especially before and after installation), the temperature changes by dozens of degrees,
Causes volume change. Particularly in the case of volumetric expansion, if the containment chamber is not airtight, the moisture-proof oil will leak, whereas if the containment chamber is completely airtight, the containment chamber will be under high pressure, which will increase the transmission loss of the optical fiber. .

(4) Purpose of the invention The purpose of the present invention is to solve the above problems;
Specifically, the object of the present invention is to provide a casing for an optical submarine repeater that has a simple structure and can achieve highly reliable airtightness and good optical transmission characteristics.

(5) Structure of the Invention The optical submarine intermediate supply and dexterity housing according to the present invention basically has two end plates at each end of an integral cylindrical body, which are airtight against the inner surface of the body. The structure is such that an optical fiber connecting portion accommodating chamber is formed between the two end face plates.

Further, the optical submarine repeater casing according to the present invention has a configuration in which the optical fiber connection portion housing chamber is filled with moisture-proof oil and an achievable evaporator is provided for absorbing pressure changes caused by thermal expansion and contraction of the moisture-proof oil. This is what I did.

(6) Embodiments of the invention Hereinafter, embodiments of the invention will be described in detail with reference to the drawings.

The figure shows an embodiment of the present invention, in which reference numeral 1 indicates a multicore optical fiber cable, 2 indicates a repeater, and 3 indicates a repeater housing. The figure shows the state of connection between the optical fiber cable 1 and the repeater 2, but only one end of the repeater is shown, and the other end is omitted because it is symmetrical to the illustrated end.

The housing 3 has an integral cylindrical body 1o, and two end plates 11 and 1 are provided at each of the left and right ends (only the left end is shown), respectively.
2 is provided. The end plates 11 and 12 are respectively inserted from the ends of the fuselage 1o and fixedly held by the flanges 13 and 14, and are connected to the inner surface of the fuselage 10 and the end plate 11.
, , 12 are hermetically sealed by a rubber O-ring 15 and a metal O-ring 16. As a result, there are three compartments in the T-body 3, namely, the central compartment 4 between the left and right inner end plates 12 (the left (only 111 shown) is shown), and the central compartment 4 between the outer end plate 11 and the inner end plate 12. Two compartments on the left and right 5
(Only the left side is shown) is formed. The central compartment 4 is a room in which the repeater 2 is accommodated. The left and right compartments 5 contain an optical fiber and a power supply line that are airtightly passed from the optical fiber cable 1 to the feedthrough 17 (which also serves as the center tension member retention part) of the outer end plate 11, and the inner end plate 11. This is a chamber for accommodating a connecting portion 19 to an optical fiber and a power supply line that passes through the twelve feedthroughs 18 in an airtight state.

Inside the optical fiber connection chamber 5, there is placed an achievator 20 made of a rubber tube filled with moisture-proof oil such as polybdenum and air. When the moisture-proofing oil expands and contracts due to a change in the environmental temperature, the achievator 20 itself contracts and expands to maintain the pressure within the optical fiber connection chamber 5 below a predetermined square. In addition, %tEU of accumulator 2o
It depends on its volume and is calculated by the following formula.

v1≧P・υ ... (1) υ=αV2(
TI'To) - (2) However, vl: Air volume of the accumulator ■2: Volume of moisture-proof oil at the time of filling To: Temperature of the moisture-proof oil at the time of filling T1: Maximum temperature of the moisture-proof oil α: Volumetric expansion coefficient of the moisture-proof oil υ: Increase in volume of moisture-proofing oil in TI K* P: As an example of the limit pressure of the optical fiber connection chamber at T1, V, = 3000 (In, 'r, = 20°C.

TI=55℃, α=7X10/℃(yW Tarifun)
, P=2 and 4f/d, then according to equation (2), a=7
X10

becomes.

The housing structure described above has the following advantages.

(a) Two end plates are provided at each end of the integrally constructed body to form the optical fiber connection chamber, so there are fewer hermetic sealing points, which simplifies the structure and improves reliability. A highly airtight structure can be obtained. In particular, the repeater storage chamber has a two-hole airtight structure with an outer end plate and an inner end plate, achieving extremely excellent airtightness.

(b) In addition, by providing an achievator to fill the optical fiber connection chamber with moisture-proof oil, deterioration of the optical fiber and increase in transmission loss can be prevented, and optical transmission characteristics can be improved. .

The illustrated embodiment further has the following features.

That is, considering that the connection of the optical fiber cable 1 is ultimately performed on the laying ship, only the repeater 2 and the inner end plate 12 are assembled in the housing 3, and the outer end plate 11 and the achievator 20 are assembled into the housing 3. has a structure assembled on the optical fiber cable 1 side. Assembly in this case is performed as follows. First, after connecting the optical fibers, the outer end plate 11 is inserted into the housing 3 and fixed and held by the clamp 13.

Incidentally, at this time, the boot IA of the optical fiber cable 1 can be moved to the left and does not interfere with the work. After assembly, use the airtightness test hole 21 provided in the outer end plate 11.
Perform an airtightness test using

Thereafter, moisture-proof oil is filled into the optical fiber connection portion storage chamber 5 through the injection hole 22 similarly provided in the outer end plate 11. Although not shown, the airtight test hole 21 and the moisture-proof oil injection hole 22 are sealed by a well-known method such as press-fitting a taper cone. Finally, the boot IA is fixed to the housing 3, completing one assembly.

(7) Effects of the Invention As described above, the present invention makes it possible to obtain a housing for an optical submarine repeater that has a simple structure and can realize highly reliable airtightness and good optical transmission characteristics. The practical effects are significant.

[Brief explanation of drawings]

The figure is a longitudinal cross-sectional view of an embodiment of an optical submarine repeater casing according to the present invention in an assembled state. 1... Optical fiber cable, 2... Repeater, 3...
・Housing, 4... Repeater housing chamber, 5... Optical fiber/interconnection part housing chamber, 10... Body of housing, 11.12...
・End plate of the housing, 13.14... Clamp, 15.1
6...〇-Ring, 17... Feedthrough (center tensile body retention part), 18... Feedthrough, 19... Optical fiber connection part, 20... Achimulator, 21...
・Airtightness test hole, 22... Moisture-proof oil injection hole. Patent applicant Fujitsu Limited Patent agent Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Yukio Uchida Akira Yamaguchi

Claims (1)

[Claims] 1. In a case for an optical submarine repeater having an optical fiber connection chamber, two end plates are cut into the inner surface of each end of the integral cylindrical body to ensure an airtight seal. 2. A casing for an optical submarine repeater having a chamber for accommodating an optical fiber connection portion; A casing for an optical submarine repeater characterized by filling a moisture-proofing oil in the optical fiber connection part accommodation area and providing a 7-cumulator for absorbing pressure changes caused by thermal expansion and contraction of the moisture-proofing oil.