JPH0313905A - Water immersion sensor tool - Google Patents

Abstract

PURPOSE:To reduce the size of whole water immersion sensor tool by providing a slider whose one end can oscillate about the other end and operating this slider by the water-absorption expansion of a water-absorbing expansion material. CONSTITUTION:The water immersion sensor tool is so constituted that when water entering a closure enters a casing 40, the water-absorbing expansion material 46 expands, and consequently the slider 45 rotates around the axis 43 of one end of the slider 45. Consequently, a coated optical fiber A is pressed to abut on the slider 45 and a stopper part 46 deforms, so the transmission loss of the optical fiber deforms and water immersion into the closure is detected. Thus, the slider 45 rotates around the axis 45 of one end, so the other end surface rotates with a large force through lever operation even if the water- absorption expansion quantity of the water absorbing expansion material 46 is slight. Thus, the whole water immersion sensor tool is reduced in size and variation in the transmission loss of the optical fiber is obtained in case of water immersion.

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 cables, and if the copper wires in the copper cables get wet, communication will be disrupted.
It has become an important issue to prevent the outer surface of copper wire cables from being damaged and the internal copper wires from being flooded with water. To prevent the above-mentioned flooding, a measure called the so-called "gas maintenance method" has usually been taken. This is done by filling a constant amount of gas inside the cable and keeping it at a constant pressure, and then the pressure decreases as the gas flows out of the cable.
The purpose is to detect damage to the cable (and eventually water intrusion into the cable).

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.

This type of optical fiber cable end 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 inserted from the other end face. The optical fibers are introduced and pulled out from both ends and 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.

[Problem that the invention seeks to solve]

For this reason, the present inventors have developed and researched a water immersion sensor device that is easy to maintain and have a long life, and have already filed patent applications (Japanese Patent Application No. 1-46860 and 1-51768).

[Problem that the invention seeks to solve]

The water immersion sensor device (hereinafter referred to as “
As shown in FIG. 5, the water immersion sensor device according to the first proposal is disposed at the bottom of a cylindrical closure 6, and is connected to a pair of left and right optical fiber cables 1 and 1a introduced into the closure 6. The optical fiber core A that has been pulled out and butted together is housed inside. In FIG. 5, 2, 2a are cable gripping parts, 3, 3a
is a tension member, 4.4a is a tension member gripping portion, 10 is a connecting portion storage portion (excess length processing portion) for the optical fiber core A, and 7 is an end plate. As is clear from the above drawing, the water immersion sensor device 8 according to the first proposal houses the connecting portion of the optical fiber core A at the lowest stage, which is not used for optical communication, and as shown in FIG. , a rectangular box-shaped casing 20 with a bottom through hole, and four legs 2
The casing 20 is provided with a lid body 20a that removably covers the casing 20 by engaging the first claw with the recessed portions at the four corners of the four casings 20. The above rectangular box-shaped casing 20
Inside, a water-absorbing expansion material 26 and end plates 24 and 25 provided on the front surface thereof are disposed, and the optical fiber core A passing through the pair of optical fiber core openings 27 provided in the casing 20 is protected from water ingress. It is sometimes bent. That is, when water enters the casing 20, the water-absorbing and swelling material 26 absorbs water and expands, sandwiching the optical fiber core A and bending it as shown by arrow B. This changes the transmission loss of the optical fiber, which can be used to detect flooding. However, this water immersion sensor device has a drawback in that its widthwise dimension (W) is somewhat large.

In addition, the water immersion sensor device of Japanese Patent Application No. 1-51768 (hereinafter abbreviated as “the water immersion sensor device according to the second proposal”) is
As shown in the figure, it has a rectangular box-shaped casing 20 and four claws 22a, and the claws 22a are attached to the casing 2.
The casing 22 is provided with a lid body 22 having a through hole on the upper surface which engages with the recessed portion of the casing 2 and removably covers the casing 22. Inside the rectangular box-shaped casing 20, the left side is a room block 30.
The right side portion is formed into a solid block 31. In the room block 30, a pair of left and right water absorbing and expanding materials 26 and their end plates 24 are arranged.

34 is a stopper for fixing the optical fiber core A to the end plate 34. The solid block 31 is provided with a housing portion 29 that accommodates the optical fiber core A when it is curved as shown in B. 35 connects the optical fiber core A to the solid part 31
A fixture 31a is a concave portion thereof. In this water immersion sensor device, when water floods into the casing 22, the water-absorbing and swelling material 26 expands and advances the end plate 32 to the position indicated by the arrow C, thereby bending and deforming the optical fiber core A as shown by the chain line B. It is designed to change optical transmission loss. However, this water immersion sensor device has a drawback in that the length 2 in the axial direction is long.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a water immersion sensor device that has a small length in the width direction and length direction and can be miniaturized.

[Means for solving problems]

In order to achieve the above object, the water immersion sensor device of the present invention is disposed on the bottom part of a cylindrical closure that coaxially accommodates a connection part that connects the ends of one optical fiber cable and the other end of the optical fiber cable. and a box-shaped casing that accommodates any one of the plurality of optical fiber cores pulled out and connected from the end of the other optical fiber cable, the box-shaped casing having at least the bottom side formed as a water absorption part. , provided in the casing approximately along an imaginary line connecting the pair of optical fiber outlet ports formed on the wall surface of the box-shaped casing and the pair of optical fiber outlet ports, with one end as the center and the other end. The slider is provided with a swingable slider, and a water absorbing and expanding material provided in the box-shaped casing so as to press and bias the other end of the slider in the direction of the imaginary line when the slider absorbs water and expands.

[Effect]

The water immersion sensor device of the present invention is provided with a slider in a casing, the other end of which is swingable around one end, and the other end moves in an arc around one point by the water absorption and expansion of the water-absorbing and expanding material. , so to speak, applies leverage to bend the optical fiber. Therefore, the small water absorption expansion of the water absorption expansion material can be amplified and utilized, and can be converted into a strong force.

As a result, the entire water immersion sensor device can be made smaller.

Next, examples will be described.

〔Example〕

1 and 2 show one embodiment of the invention. In these figures, 40 is a box-shaped casing;
An optical fiber outlet 41 is provided at one end, and an optical fiber outlet 42 is formed at the other end diagonally to the optical fiber outlet 41. Then, the optical fiber core outlet 4 on the one end side
A shaft body 43 is implanted in the vicinity of the shaft body 43, and a long plate-shaped slider 45 formed on a cylinder body 44 whose end part fits loosely into the shaft body 43 is attached to the cylinder body 44. The shaft body 43
4G is a substantially triangular water-absorbing and expanding member that is fitted in the box-shaped casing 40 and is installed at a corner inside the casing surrounded by the slider 45 and the wall of the box-shaped casing 40. A portion of the casing facing the front portion of the water-absorbing and expanding material 46 is formed into a solid abutting portion 47 . 4
Locking protrusions 8 engage with locking claws 50 provided at the four corners of the lid 49 to removably cover the box-shaped casing 40. A denotes an optical fiber that passes through the pair of optical fiber outlet ports. The water immersion sensor device having such a structure is disposed in the closure 6 shown in FIG. 5 as shown in the figure, like the water immersion sensor device according to the above proposal.

In this configuration, when water that has entered the closure reaches the inside of the casing 40, the water-absorbing and expanding material 46 expands, thereby causing the slider 45 to rotate around one end as shown by the 20th chain line. As a result, optical fiber core A
is pushed and deformed by being sandwiched between the slider 45 and the abutting portion 47, the transmission loss of the optical fiber changes and water intrusion into the closure is detected. in this way,
Since the slider 45 rotates around one end, even if the amount of water absorption and expansion of the water absorption and expansion material 46 at the other end is small, the slider 45 rotates with a large and strong force due to the lever action. Therefore, even if the water immersion sensor device is small, it will bring about a change in the transmission loss of the optical fiber that is sufficient to detect water immersion.

FIG. 3 is a block diagram of another embodiment. In this example,
The optical fiber core A is formed to cross the center of the box-shaped casing 40. Other than that, this embodiment is substantially the same as the embodiment described above, and produces the same effects.

FIG. 4 shows yet another embodiment. In this embodiment, a pair of shaft bodies 43 are provided inside the box-shaped casing 40 so as to be diagonal to each other, and an end cylinder 43 is provided on each of the shaft bodies.
A slider 45 with 4 is attached, and a water-absorbing and expanding material 46 is provided to operate the slider 45 in combination with the slider 45, so that bending forces are applied to the - optical fiber cores A from mutually opposite directions. . With this configuration, even the relatively rigid optical fiber core wire A can be bent to a large extent, thereby making it possible to reliably change the transmission loss of light.

In the above embodiment, the box-shaped casing 40 is arranged horizontally in the closure 6, but depending on the situation, the box-shaped casing 40 may be arranged in an upright state.

〔Effect of the invention〕

As described above, the water immersion sensor device of the present invention is provided with a slider whose one end is pivotable and the other end is swingable, and this slider is operated by water absorption and expansion of the water-absorbing and expanding material. Even when the amount of fat expands, the lever action causes the other end of the slider to rotate with great force.

Therefore, even if the overall size of the water immersion sensor device is made smaller, the transmission loss of the optical fiber can be sufficiently changed when immersed in water.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of one embodiment of the present invention, Fig. 2 is a plan view with the lid removed, Fig. 3 is a plan view of another embodiment with the cover removed, and Fig. 4. 5 is a plan view of another embodiment with the lid removed, FIG. 5 is a vertical sectional view of the water immersion sensor attached to the closure, and FIG. 6 is an example of the water immersion sensor that is the basis of this invention. An exploded perspective view, and FIG. 7 is a plan view of another example with the lid removed.

Claims (1)

[Claims] (1) Disposed on the bottom of a cylindrical closure that coaxially accommodates a connection part that connects the ends of one and the other optical fiber cables, and is pulled out and connected from the ends of the one and other optical fiber cables. A water immersion sensor device for accommodating any one of a plurality of optical fiber cores, which comprises a box-shaped casing with at least a bottom surface formed as a water absorption part, and a pair of casings formed on the walls of the box-shaped casing. a slider provided in the casing substantially along a virtual line connecting the optical fiber outlet and the pair of optical fiber outlet, the other end being swingable around one end; and the slider when expanded by water absorption. A water immersion sensor device comprising a water-absorbing and expanding material provided in the box-shaped casing so as to press and bias the other end in the direction of the imaginary line.