JPH0422285Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a liquid detection sensor that detects the location of leakage of water, oil, etc.

[Conventional technology]

Conventionally, as this type of liquid detection sensor, there is a conductive liquid detection sensor as disclosed in Japanese Utility Model Application No. 188536/1983. This conductive liquid detection sensor is
At least two electric wires are arranged with insulation between each other and the outside with an insulating material, and these at least two electric wires are exposed at the conductive liquid detection position to constitute a unit sensor. Multiple unit sensors are fixed in parallel on the surface of a wide resin sheet to expand the detection area for liquid leakage, etc., and detect leakage of conductive liquid by checking continuity at exposed positions of electric wires. etc. are detected.

[Problem that the invention attempts to solve]

However, in such conventional examples,
Since the sensor itself is wide, there was a problem that it could not be placed properly depending on the location for detection purpose.

Further, there is a problem in that at least two electric wires are required to secure one detection position, and a large number of electric wires are required to perform detection at multiple locations.

Furthermore, there was a problem in that leakage etc. could not be detected at locations other than the exposed position of the electric wire.

This device was devised by focusing on the problems of the conventional method, and is a liquid detection method that has a wide detection position area for leaks, etc., and also enables detection of conductive liquids, oil liquids, etc. The purpose is to obtain a sensor.

[Means for solving problems]

This invention includes an inner conductor, at least two insulated wires disposed along the inner conductor, electrically insulated from the inner conductor by the insulated wires, and disposed along the inner conductor. The structure includes a liquid-permeable outer conductor that is disposed to form a liquid intrusion space between the inner conductor and the inner conductor.

[Effect]

When liquid enters the liquid intrusion space interposed between the inner conductor and the outer conductor through the liquid-permeable outer conductor, if the liquid is a conductive liquid, both conductors are electrically conductive and insulated. It is possible to detect the location of leakage etc. using the Murray loop method using covered electric wires,
When the liquid is oil, the position of oil leakage etc. can be detected by pulse reflection method or other means using the insulated wire.

〔Example〕

Hereinafter, details of the liquid detection sensor according to the invention will be described with reference to a first embodiment shown in the drawings.

In the figure, 1 is an internal conductor, and two insulated wires 2a and 2b are wound around the internal conductor 1 with a gap between them. Furthermore, a braided conductor layer is provided on the outside of the insulated wire 2 as a liquid-permeable outer conductor 3, so that leakage liquid can enter the inside through the gaps 3a between the braided wires of the outer conductor 3. It's becoming possible. Further, a liquid intrusion space 4 is formed between the inner conductor 1 and the outer conductor 3 by the insulated wires 2a and 2b so that the liquid intruding from the space 3a can reach the inner conductor 1. ing.

When such a liquid detection sensor A is used as a sensor for detecting leakage of conductive liquid or oil liquid, the liquid detection sensor A should be used to detect leakage in pipes, tanks, etc. for liquid conveyance where leakage is to be managed. It should be placed in a position where it can come into contact with leaking liquid.

When confirming the leakage position of the conductive liquid using the liquid detection sensor A arranged in this way, as shown in Fig. 2, this is done by determining the short circuit position S of the inner and outer conductors 1 and 3. be. This method connects the insulated wire 2a and the inner conductor 1, and also connects the insulated wire 2b and the outer conductor 3 at one end of the liquid detection sensor A. The short circuit position S is determined by comparing the resistance values of the a section and the b-a section from the other end to the short circuit position S. Note that the resistance values in the a section and the b-a section are the inner and outer conductors 1 and 3 and the insulated wires 2a and 2b on the other end side of the liquid detection sensor A.
It is calculated by appropriately measuring the resistance value between the terminals.

FIG. 3 shows a second embodiment of the liquid detection sensor A according to this invention.

In this embodiment, four insulated wires 2
are disposed along the longitudinal direction on the outer circumferential surface of the internal conductor 1, and an external conductor is further braided and surrounded from the outside of the insulated wire 2.

Two of the insulated wires 2 can be used as power supply lines.

It goes without saying that in this embodiment as well, by using the same method as in the first embodiment, it is possible to detect the leakage position of the conductive liquid.

Although the first embodiment and the second embodiment have been described above, the liquid detection sensor according to the present invention allows considerable design changes depending on the gist of its configuration.

In addition, the liquid detection sensor according to this invention not only detects conductive liquids but also detects crude oil, petroleum, gasoline, etc. by using pulse reflection method etc.
It is also possible to detect the leakage position of oil such as kerosene MEK, water vapor or other gas.

Furthermore, in both of the above embodiments, the liquid-permeable external conductor 3 is disposed on the outermost side, but the outside of the external conductor 8 is made of a wire-shaped insulating material or porous tetrafluoroethylene resin. It is of course possible to apply this invention to a structure that can be coated with a selectively permeable membrane, and can also be applied to detection locations such as aboveground or underground metal conveyance pipes and tanks.

[Effect of idea]

As is clear from the above description, the liquid detection sensor according to this invention has the effect of being able to detect liquid at any position in the longitudinal direction.

In addition, since there is no need to separately install electric wires for position detection, power supply, etc., not only can the sensor be made smaller, but it can also be manufactured at low cost, and it does not take up much space for installation, which improves work efficiency. There is.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway side view showing the first embodiment of this invention, Fig. 2 is an explanatory diagram showing the connection state of the liquid detection sensor when detecting the short circuit position S, and Fig. 3 is an explanatory diagram showing the connection state of the liquid detection sensor when detecting the short circuit position S. FIG. 3 is a cross-sectional view showing a second embodiment. 1...Liquid detection sensor, 1...Internal conductor, 2
a, 2b...Insulated wire, 3...External conductor, 4
...Liquid infiltration space.

Claims (1)

[Claims for Utility Model Registration] (1) An internal conductor, at least two insulated wires disposed along the internal conductor, and electrically insulated from the internal conductor by the insulated wires, A liquid detection sensor comprising: a liquid-permeable outer conductor that is disposed along the inner conductor and forms a liquid intrusion space between the inner conductor and the inner conductor. (2) The insulated wire is wound around the inner conductor, and the outer conductor is braided to integrally surround the inner conductor and the insulated wire. Liquid sensor as described.