JPH02227633A - Water immersion sensor tool - Google Patents

Abstract

PURPOSE:To speedily and accurately detect water immersion by providing a couple of water-absorptive expansion materials with curved surface parts facing each other across coated optical fibers on an upper porous bottom plate which is charged in a casing. CONSTITUTION:The coated optical fibers 5 and 5a are arranged as shown by a chain A while arranged between a couple of pressure plates 24 and 25 whose coupling parts are combined with the water-absorptive expansion materials 26. Then a box type casing 20 that the coated optical fibers 5 and 5a penetrate is covered with a lid to form the water immersion sensor tool, which is arranged on the bottom part of a closure 6. When water enters the closure 6 in this state, the water is speedily absorbed by the upper porous bottom plate 23 through through holes of the bottom surface of the casing 20 and absorbed by the expansion materials 26. The expansion materials speedily expand by the water absorption to narrow down the gap between both the pressure plates 24 and 25, so the coated optical fibers 5 and 5a which are straight when not impregnated with water bend as shown by a chain line B to increase the transmission loss of light. For the purpose, this is detected to speedily and accurately grasp the water immersion in the closure 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a water intrusion sensor device used for detecting the intrusion of water into a cylindrical closure housing a connecting portion of an optical fiber cable.

[Conventional technology]

Conventional communication networks use copper wire cables, and if the W4 wire inside this copper wire gets wet, communication will be disrupted, causing damage to the outer surface of the copper wire cable and flooding the inner copper wire. Preventing the situation was an important issue. To prevent the above-mentioned flooding, a measure called the so-called "gas maintenance method" has usually been taken. This is a situation in which a certain amount of gas is always sealed inside the cable and maintained at a certain pressure, and when the gas leaks out of the cable, the above pressure decreases, causing damage to the cable (and eventually water intrusion into the cable). The purpose is to detect.

However, recently, optical fiber cables have been used instead of the copper wire cables mentioned above, and since the optical fiber core wires used for communication in these optical fiber cables are sufficiently protected, water intrusion etc. can only be detected at the connection part. It is now sufficient to carry out maintenance and management.

[Problem that the invention seeks to solve]

This type of optical fiber cable connection generally uses a cylindrical closure, in which one end of the optical fiber cable is introduced into the closure from one end face, and the other end of the optical fiber cable is introduced from the other end face. Optical fiber cores drawn out from both ends are connected with their ends butted against each other. It is not appropriate to use the conventional gas maintenance method for the connection portion of an optical fiber cable having such a structure because of problems such as structural problems and management costs.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a water intrusion sensor device that is easy to maintain and manage and can quickly detect water intrusion at a connecting portion.

[Means for solving problems]

In order to achieve the above object, the water immersion sensor device of the present invention is disposed in the bottom part of a cylindrical closure that coaxially accommodates a connecting part connecting the ends of one and the other optical fiber cable, and A water immersion sensor device that coaxially accommodates any one of a plurality of optical fiber core wires pulled out and connected from the end of an optical fiber cable so as to come into contact with infiltrating water, the bottom surface of which is the cylindrical closure. A box-shaped casing with a bottom through hole formed on a curved surface that follows the curved surface of the bottom surface, optical fiber core outlet ports formed opposite to each other on both end surfaces perpendicular to the axial direction of the casing, and a bottom surface of the casing. a porous upper bottom plate formed into a curved surface along the bottom surface and a flat top surface, which is filled in the casing; It has a configuration including a pair of water-absorbing and expanding materials.

[Effect]

The present inventors focused on the characteristic of optical fibers that the amount of light passing through the optical fiber changes when the optical fiber is physically bent. The idea was that the above water intrusion could be detected quickly and accurately by converting it into a bending force. Then, as the material used for the above conversion, a water-absorbing and expanding material that absorbs water and expands is used, and
The present invention was achieved by discovering that a highly reliable water immersion sensor tool could be obtained by devising the mounting tools.

Next, the present invention will be explained based on examples.

〔Example〕

FIGS. 1 and 2 show how a water immersion sensor device according to an embodiment of the present invention is installed. In these figures,
1. la is a pair of left and right optical fiber cables, 2=2a
3.3a are cable grips for fixing and holding the ends of the optical fiber cables 1 and 1a, respectively; The tension member 4.48 drawn out from the end of la is a tension member gripping portion that fixes and holds the tension members 3, 3a. Reference numerals 5 and 5a designate a plurality of optical fibers drawn out long from the end of the optical fiber cable, and the end surfaces of the optical fibers 5.5a are butted against each other and connected, and the outer periphery of the connecting portion is covered with tape or the like. Covered and sealed.

1O is its covering seal, and 6 is a cylindrical closure that accommodates these in a watertight manner. Further, 7 is an end plate that closes both ends of the closure 6. Then,
Bottom optical fiber core not used for optical communication 5.5
The water immersion sensor device 8 of the present invention is attached to the cover sealing portion 10 of a. As shown in FIGS. 3 to 6, the water immersion sensor device 8 includes a box-shaped casing 20 with a bottom through hole, the bottom of which is curved along the curved surface of the bottom of the cylindrical closure 6, and four The casing 20 is removed by the engagement of the claws of the leg portions 21 with the recesses of the casing 20.
It is equipped with a lid body that can be attached and detached at will. As shown in FIG. 4, a porous upper base plate 23 made of a porous water-absorbing resin whose main component is polyethylene or phenol resin is accommodated in the casing. The porous upper base plate 23 has a bottom surface formed into a curved surface along the bottom surface of the casing 20, and a top surface formed into a flat surface.

Then, on the upper surface of this porous upper bottom plate 23, a push plate 2 having a protrusion with an optical fiber core indicated by a chain line A sandwiched therebetween.
4 and a push plate 25 having a recessed portion are arranged in a facing state. Between these push plates 24, 25 and the wall surface of the box-shaped casing 20, ethylene-propylene-diene rubber (EPD)
A water-absorbing and expanding material 26 made of water-absorbing and expanding rubber containing M) as a main component and having a water-swelling agent and a water-absorbing agent dispersed throughout is disposed. The optical fiber core 5.5a is formed in a facing state, and the optical fiber core 5.5a
The state in which the inside of the casing 20 is crossed (11 is line A)
It is a drawer opening for passing through.

In this configuration, the optical fiber core wires 5, 5a are connected to each other by a water-absorbing and expanding material 2, as shown in FIGS. 5 and 6.
The chain l! is placed between the pair of push plates 24 and 25 combined with 6! It is arranged like liA. Next, the box-shaped casing 2 is passed through the optical fiber core wires 5, 5a.
0 and 122 to form a water immersion sensor device, which is disposed at the bottom of the closure 6. In this state, when water enters the closure 6, the water passes through the holes in the bottom of the box-shaped casing 20, is quickly absorbed by the porous upper base plate 23, and then absorbed by the water-absorbing and expanding material 26. Due to this water absorption by the water-absorbing and expanding material 26, the water-absorbing and expanding material 26 rapidly swells and the distance between the push plates 24 and 25 narrows, so that the optical fiber cores 5 and 5a, which were in a straight state in the non-water immersed state,
is bent as shown by the chain line B, thereby increasing the transmission loss of light. Therefore, by detecting this, it becomes possible to quickly and accurately determine whether water has entered the closure 6.

In the above embodiment, the push plates 24 and 25 and the water-absorbing and expanding material 26 are separate bodies, but they may be integrated, for example by making the front surface 4 of the water-absorbing and expanding material 26 into a pushing plate. , the lid 22 of the box-shaped casing 20 may be removed depending on the case.

〔Effect of the invention〕

Since the water immersion sensor device of the present invention is configured as described above, it is possible to quickly and accurately detect water immersion within a cylindrical closure, and maintenance management at this time is extremely simple.

In particular, this water immersion sensor device has a box-shaped casing whose bottom surface is formed into a curved surface that follows the bottom surface of the cylindrical closure. Provided with a porous upper bottom plate,
A water-absorbing and expanding material is disposed on the flat surface of this porous upper bottom plate when it expands due to water absorption and applies bending force to the optical fiber core, so if even a small amount of water enters the bottom of the cylindrical closure, The infiltrated water passes through the perforations in the bottom of the box-shaped casing along the bottom of the cylindrical closure, passes through the porous upper base plate, and reaches the water-absorbing and inflatable material accurately and quickly. Therefore, it becomes possible to quickly detect water intrusion into the cylindrical closure.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing an installed state of an embodiment of the present invention, Fig. 2 is a cross-sectional view taken along the line C-C', Fig. 3 is a perspective view of the water immersion sensor, and Fig. 4 is an exploded perspective view thereof. , FIG. 5, and FIG. 6 are diagrams explaining the operating state. 1.la...optical fiber cable 5.5a...
Optical fiber core 6...Cylindrical closure 8.
... Water immersion sensor tool 20 ... Box-shaped casing 23
...Porous upper bottom plate 24.25...Press Fi26...
・Water-absorbing expansion material 27... Outlet patent applicant Tokai Rubber Industries Co., Ltd.

Claims (1)

[Claims] (1) A plurality of fiber optic cables disposed on the bottom surface of a cylindrical closure that coaxially accommodates the connecting parts that connect the ends of one and the other optical fiber cables, pulled out from the ends of both optical fiber cables, and connected. A water immersion sensor device coaxially accommodates any one of the optical fiber cores in such a manner that it comes into contact with infiltrating water, the bottom surface being transparent and having a bottom surface formed in a curved surface along the curved surface of the bottom surface of the cylindrical closure. A box-shaped casing with a hole, optical fiber outlet openings formed opposite to each other on both end surfaces perpendicular to the axial direction of the casing, a bottom surface formed in a curved surface along the bottom surface of the casing, and an upper surface formed in a flat surface. The casing is filled with a porous upper base plate, and a pair of water-absorbing and expanding materials with curved surfaces facing each other on the porous upper base plate with the optical fiber core sandwiched therebetween. Water immersion sensor device.