JPH097432A - Cable having water leakage detecting function - Google Patents

Abstract

PURPOSE: To detect production of water leakage around a cable with high sensitivity by using these while protecting water leakage detecting conductors, and wire the cable in a free shape. CONSTITUTION: A sheath to cover a cable body is divided into an inside sheath 5 and an outside sheath 8, and at least a pair of leakage water detecting conductors 6 are arranged between these so as to separate from each other in the circumferential direction. In the outside sheath 8, through holes 9 are arranged in parts to cover the respective leakage water detecting conductors 6. Much preferably, a moisture transmitting member 7 to quickly transmit moisture to both leakage water detecting conductors 6 by a capillary phenomenon is arranged between both leakage water detecting conductors 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable having a water leak detecting function.

[0002]

2. Description of the Related Art In recent years, in addition to electrical equipment such as lighting equipment, computer equipment and
Various information / communication devices such as facsimiles, modems, and telephone facilities have come to be installed side by side (for example, Japanese Patent Laid-Open No. 5-1).
(See Japanese Patent Publication No. 99633). In such an intelligent building, water leakage may cause large damage. Therefore, by installing a water leakage detection system in addition to the above equipment, early detection and treatment of water leakage are being attempted. .

By the way, in the above-mentioned building, an information communication cable is wired over a wide area in accordance with the installation of various information / communication devices, and further, a preceding wiring (which can be used in a future situation). In some cases, wiring is performed as expected. Therefore, by adding a water leak detection function to these cables, it is possible to secure a vast water leak detection area with a smaller number of cables compared to the case where a water leak detection system is constructed using a dedicated cable. .

Therefore, as a cable having the above-described water leakage detection function, Japanese Utility Model Laid-Open No. 62-26817 discloses an under carpet cable in which the cable body is sandwiched between a top shield and a bottom shield from above and below. It is shown that a water leak detection line is provided on the upper surface of the top shield via an insulating layer.

Further, Japanese Unexamined Patent Publication No. 6-187842 discloses a pair of water leak detection wires, which are twisted together with a cable core in a state of being vertically separated from each other and covered with a sheath. .

[0006]

[Problems to be Solved by the Invention] Japanese Utility Model Laid-Open No. 62-2681
In the case of the publication No. 7, since the entire water leak detection line is completely exposed to the upper side, the arrangement of the water leak detection line may be collapsed even if a small external force is applied thereto, and the water leak detection line itself is also damaged. There is an inconvenience that it is easy to do. Moreover, in order to stably arrange this water leak detection line, the water leak detection line must be laid on the upper surface of the cable. From this relationship, the wiring form of the cable is significantly restricted. It is limited to just a few cables, such as carpet cables. Therefore, it is very difficult to detect water leakage using a cable that is wired in advance.

On the other hand, in the case of Japanese Patent Laid-Open No. 6-187842, since the water leak detection line is sealed in the sheath together with the cable core, the water leak detection line is sufficiently protected, but the No leak is detected unless water enters. Therefore, although it is possible to accurately detect whether or not water has entered the cable, it is extremely difficult to detect with high sensitivity whether or not water has leaked in the area around the cable.

In view of such circumstances, the present invention can detect the occurrence of water leakage around a cable with high sensitivity by using the water leakage detection conductor while satisfactorily protecting the water leakage detection conductor.
Moreover, it is an object of the present invention to provide a cable with a water leak detection function that can be wired in a free form.

[0009]

As a means for solving the above problems, the present invention provides a cable comprising a cable main body and a sheath covering the cable main body over the entire circumference thereof, wherein the sheath is an inner sheath. It is divided into an outer sheath, and at least a pair of leak detection conductors are arranged between the inner sheath and the outer sheath so as to be spaced apart from each other in the circumferential direction. A plurality of through holes arranged in the cable axial direction are provided (Claim 1).

In this cable, a plurality of pairs of water leakage detection conductors may be arranged side by side in the circumferential direction between the inner sheath and the outer sheath (claim 2).

Further, by providing a moisture transmitting member for transmitting moisture by the capillary phenomenon between the pair of leak detecting conductors, a more excellent effect as described later can be obtained (claim 3).

[0012]

According to the cable of the present invention, when water leaks around the cable, the water comes into contact with both the water leak detecting conductors through the through holes provided in the outer sheath, and these water leak detecting conductors are contacted. It serves as an electrical medium between the two and reduces the insulation between the two. Therefore, by monitoring this insulation property, it is possible to immediately detect the occurrence of water leakage. Moreover, since each of the water leakage detecting conductors is well protected by the outer sheath and is firmly held, the cable can be wired in a free form. Also, like the conventional cable, the cable body is reliably protected by both the inner sheath and the outer sheath, and the inner sheath prevents water from entering the cable body.

In the cable according to the second aspect, since a plurality of pairs of water leakage detecting conductors are arranged side by side in the circumferential direction, a wider detectable area is provided as compared with the case where only one pair of water leakage detecting conductors is provided. It is possible to further reduce the distance between the pair of water leakage detection conductors while ensuring the distance. Therefore, as this interval is narrowed, the sensitivity of water leakage detection is increased. It is also possible to understand in which direction of the cable the water leakage mainly occurs by confirming which water leakage detection conductor pair the insulation deterioration is remarkable.

In the cable, moisture on the outside of the cable serves as a medium to reduce the insulation between the leak detection conductors. In addition to this, in the cable according to claim 3, the outer sheath has a through hole. Moisture that has entered the sheath through the sheath can quickly spread between the leak detection conductors due to the capillary phenomenon in the moisture transmission member, and serve as a medium between the leak detection conductors. Therefore, the sensitivity of water leak detection is further increased.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, two electric wires 3 each consisting of a conductor 1 and an insulator 2 are twisted in pairs, and four pairs of the twisted wires 4 are bundled to form a cable body.

In the present invention, the concrete structure of the cable body is not limited, and the present invention can be applied to various cables such as a horizontal winding shield wire and a coaxial cable in addition to the multicore cable shown in the figure.

The cable body is entirely covered with a synthetic resin sheath. The sheath is divided into an inner sheath 5 and an outer sheath 8, and a pair of water leakage detection conductors 6 are provided between the both sheaths 5 and 8. These water leakage detection conductors 6 are formed in a thin plate shape in order to reduce the diameter of the cable, and are arranged at positions separated by 180 ° in the circumferential direction.

A plurality of through holes 9 arranged in the axial direction of the cable are provided in a portion of the outer sheath 8 which covers each of the water leak detecting conductors 6. In this embodiment, as shown in FIG. 2, circular through holes 9 having a diameter smaller than the width dimension of the water leakage detecting conductor 6 are arranged in parallel in the cable axial direction at intervals P.

Further, a moisture transmission member 7 is provided between the two water leakage detecting conductors 6. As the moisture transmission member 7, a member that quickly transmits moisture to each water leakage detection conductor 6 by a capillary phenomenon is preferable, and paper tape, cotton, or the like is preferable.

By wiring such a cable at a proper place in a building, when water leakage occurs at the wiring portion, this can be detected with high sensitivity.

Specifically, when water leaks around the cable, the water leaks through the through holes 9 and the water leak detecting conductors 6 are provided.
Since the moisture on the outer side of the cable serves as a medium for electrically connecting both the water leakage detecting conductors 6 with each other, the insulating property of both the water leakage detecting conductors 6 is reduced as compared with the case where no water leakage occurs. Therefore, by measuring and monitoring the insulation resistance between the water leakage detection conductors 6, it is possible to detect the occurrence of water leakage quickly.

Further, in this embodiment, since the moisture transmission member 7 is interposed between the water leak detection conductors 6 of both devices, the moisture that has entered the inside of the outer sheath 8 through the through hole 9 is also described above. Due to the capillary phenomenon in the moisture transmission member 7, the water leakage detection conductor 6 quickly spreads and can serve as an electric medium. Therefore, the water leak detection sensitivity is further enhanced as compared with the case where the moisture transmission member 7 is not provided.

In this cable, since the water leakage detecting conductor 6 is protected by the outer sheath 8 and is stably held at a predetermined position, the water leakage detecting conductor 6 is hardly displaced or damaged and is stable. The cable can be routed in any form as it is. Therefore, the present invention can be applied to a cable that is pre-wired in a building, which brings about an advantage that a pre-wiring that is not used at the present time can be effectively used as a water leakage detection cable.

Further, since the cable body is protected by both the inner sheath 5 and the outer sheath 8, each sheath 5, 8 may be thinner than the conventional sheath, and therefore, the cable outer diameter is hardly increased. A leak detection conductor 6 can be added. Further, the inner sheath 5 can reliably prevent water from entering the cable body.

The second embodiment is shown in FIG. In this embodiment, two pairs of water leakage detecting conductors 6A and 6B are arranged side by side in the circumferential direction, and the moisture transmitting member is provided between each pair of water leakage detecting conductors 6A and between each pair of water leakage detecting conductors 6B. 7
A and 7B are provided. Then, the first sheath is formed on the outer sheath 8 in a portion that covers the water leakage detecting conductors 6A and 6B.
Through holes 9A and 9B similar to those in the embodiment are provided.

By arranging a plurality of pairs of water leakage detecting conductors in this way, it is possible to reduce the distance between the pair of water leakage detecting conductors while ensuring a wide angle area as a water leakage detecting area. Therefore, the water leak detection sensitivity can be increased accordingly. Further, by confirming which of the pairs of water leakage detection conductors has a significant decrease in insulation, it is possible to grasp in which direction of the cable the water leakage mainly occurs.

In the present invention, it is not necessary that the leak detecting conductors are evenly arranged in the circumferential direction, and even if the leak detecting conductors are arranged on one side (right side in FIG. 3). Good.
In this case, it suffices to wire the portions where the leak detection conductors are densely arranged in the direction in which water easily leaks.

A third embodiment is shown in FIG. In this embodiment, the through hole 9 provided in the outer sheath 8 has a rectangular shape. As described above, in the present invention, regardless of the shape, size, and number of the through holes, they may be freely set within a range in which the outer sheath can sufficiently protect the leak detection conductor.

A fourth embodiment is shown in FIG. In this embodiment, four pairs of twisted wires 4 are arranged in a line in the horizontal direction, and the inner sheath 5 and the outer sheath 8 cover the rectangular shape,
A pair of left and right water leakage detection conductors 6 and a moisture transfer member 7 are arranged on the upper surface of the inner sheath 5, and an outer sheath 8 is covered thereon.

As described above, the present invention can be widely applied to various cables regardless of the sectional shape of the entire cable.

[0032]

As described above, according to the present invention, the sheath that covers the cable body is divided into the inner sheath and the outer sheath, and at least a pair of water leakage detecting conductors are arranged between them in the circumferential direction while being spaced apart from each other. Since a plurality of through holes arranged in the cable axial direction are provided in a portion of the outer sheath that covers each of the water leakage detecting conductors, when water leaks around the cable, the moisture is immediately transmitted through the through holes of the outer sheath. The conductor for detecting water leakage can be brought into contact with the conductor, and the sensitivity for detecting water leakage can be remarkably increased as compared with the case where the conductor for detecting water leakage is provided inside the cable. Moreover,
Since each water leakage detecting conductor is well protected by the outer sheath and is firmly held, there is no risk of the arrangement being broken or damaged, and the cable can be freely routed.

Further, like the conventional cable, the cable body is surely protected by both the inner sheath and the outer sheath, and the inner sheath prevents water from entering the cable body.

Here, in the cable according to the second aspect, since a plurality of pairs of water leakage detecting conductors are arranged side by side in the circumferential direction, a wider detectable area is provided as compared with the case where only one pair of water leakage detecting conductors is provided. It is possible to reduce the distance between the pair of conductors for water leakage detection while ensuring the same, and thus it is possible to further increase the sensitivity of water leakage detection. Also, by confirming which water leakage detection conductor pair has a significant decrease in insulation,
It is also possible to know in which direction of the cable the water leakage is significant.

Further, in the cable according to the third aspect, not only the moisture on the outside of the cable but also the moisture that has penetrated into the sheath through the through hole of the outer sheath is caused by the capillary phenomenon in the moisture transmission member to cause the leakage detection of both conductors. Since it becomes a medium between both the water leakage detecting conductors by rapidly spreading between the two, there is an effect that the sensitivity of water leakage detection can be further enhanced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the line AA of FIG.

FIG. 2 is a side view of the cable with a water leak detection function according to the first embodiment of the present invention.

FIG. 3 is a sectional front view of a cable with a water leak detection function according to a second embodiment of the present invention.

FIG. 4 is a side view of a cable with a water leak detection function according to a third embodiment of the present invention.

FIG. 5 is a sectional perspective view of a cable with a water leak detection function in a fourth embodiment of the present invention.

[Explanation of symbols]

 4 twisted pair (constituting the cable body) 5 inner sheath 6,6A, 6B water leakage detection conductor 7,7A, 7B moisture transfer member 8 outer sheath 9,9A, 9B through hole

Claims (3)

[Claims] 1. A cable comprising a cable body and a sheath covering the cable body over the entire circumference thereof, wherein the sheath is divided into an inner sheath and an outer sheath, and at least between the inner sheath and the outer sheath. A pair of water leakage detecting conductors are arranged so as to be spaced apart from each other in the circumferential direction, and a plurality of through holes arranged in the cable axial direction are provided in a portion of the outer sheath that covers each water leakage detecting conductor. Cable with detection function. 2. The water leak detection function according to claim 1, wherein a plurality of pairs of water leak detection conductors are arranged side by side in the circumferential direction between the inner sheath and the outer sheath. With cable. 3. The water leakage detection function cable according to claim 1, wherein a water transmission member that transmits water by a capillary phenomenon is interposed between the pair of water leakage detection conductors. Cable with detection function.