JPH0575640U - Leak detection device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a liquid leakage detection device in which the end of the detection cable can be easily inserted into a narrow space. A structure comprising at least two conductors arranged substantially side by side and a pair of lead wires provided along the conductors,
A detection cable having a structure in which the impedance value between the conductors changes according to an incoming liquid is used, an impedance value change sensing device is connected between the conductors at the ends of the detection cable, and a terminating resistor is provided between the lead wires at the same end. A leak detecting device, characterized in that the conductor and the lead wire are connected at the other end of the detection cable. [Effect] Since the terminating resistor is connected to the impedance value change sensing device side, the other end of the detection cable is made smaller,
It is easy to insert into a narrow space.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to leak detection from, for example, a liquid transport pipe or a liquid container, and particularly to a leak detection device having a structure that can be easily inserted into a narrow portion.

[0002]

[Prior Art]

 As a device used for this type of application, the "conductive liquid detection sensor" described in Japanese Utility Model Laid-Open No. 58-96248 has been proposed. When this sensor is formed into a flat cable, it is used as a liquid leakage detection device 1a shown in a plan view of FIG. 1 and a side view of FIG.

Describing based on these drawings, there is a detection cable 5a in which conductors 2a and 2a 'which are substantially arranged side by side are supported by an insulator 3a such as a strip-shaped resin tape. In this detection cable 5a, a plurality of through holes 4a are provided on at least one surface of the insulator 3a at positions corresponding to the conductors 2a and 2a ', and the conductive liquid that has come between the conductors 2a and 2a' is provided. The presence or arrival of the conductive liquid is electrically detected by utilizing the fact that the impedance value between the conductors rapidly drops due to the bridge.

For that purpose, the impedance value change sensing device 6a is connected to one end of the conductors 2a and 2a ', and the terminating resistor 7a is connected to the other end. The terminating resistor 7a is provided to maintain the impedance value before the detection and detect the disconnection of the conductors 2a and 2a '. Further, since the detection cable 5a is used by being wound around a liquid transport pipe, a liquid container, or the like, or inserted in a narrow space, the periphery of the terminating resistor 7a is generally covered with a protective box 10a. The insulator 3a shown in the figure may use, for example, a mesh or an insulator capable of penetrating a conductive liquid, in addition to partially exposing the conductors 2a and 2a 'through the through holes 4a.

Further, as in a “distilled water leak detection element” described in Japanese Utility Model Laid-Open No. 59-137554, two comb-shaped conductors in which a large number of conductors are alternately connected in parallel are arranged apart from each other. There is also a leak detector (not shown) that facilitates the detection of liquids with high specific resistance, such as pure water, by using the detection cable supported by the insulator shown in.

Further, as in the “fluid sensing element” described in JP-A-53-145697, a carbon-containing resin is arranged between at least two conductors, and an insulating liquid such as oil is brought into contact with the resin. There is also a liquid leakage detection device (not shown) that uses a detection cable that detects the arrival of insulating liquid such as oils by taking advantage of the sudden increase in the resistance value of the resin.

[0007]

[Problems to be solved by the device]

 However, like the liquid leakage detection device 1a shown in FIGS. 1 and 2, a terminating resistor 7a and a protective box 10a, which are larger than the thickness and width of the detection cable 5a, are provided at one end (right side of the drawing) of the detection cable 5a. Therefore, the end of the detection cable 5a cannot be inserted and installed in a portion narrower than these. In view of the above problems, it is an object of the present invention to provide a liquid leakage detection device which has a terminating resistor and facilitates insertion and installation in a narrow space.

[0008]

[Means for Solving the Problems]

 The present invention has been made to achieve the above-mentioned object, and is provided with at least two conductors that are substantially spaced apart and arranged side by side, and a pair of lead wires along the conductors. A sensing cable having a structure that changes depending on the incoming liquid is used, an impedance value change sensing device is connected between the conductors at the end of the sensing cable, and a terminating resistor is connected between the lead wires at the same end, and the sensing is performed. A leak detecting device is characterized in that the conductor and the lead wire are connected at the other end of the cable.

[0009]

[Action]

 According to the present invention, the lead wire is connected to the conductor end of the detection cable, and the lead wire is arranged so as to return along the conductor, so that the terminating resistor is connected to the impedance value change sensing device side. It Therefore, since there is no end resistor on the tip side of this detection cable, the size of this part can be made smaller than before, and it is easy to insert and install it in a narrow space. It should be noted that it is of course possible to detect a leak by using the phenomenon that the impedance between the conductors of the detection cable changes depending on the incoming liquid and monitor it with an impedance value change sensing device connected to this conductor end.

[0010]

【Example】

 FIG. 3 is a plan view showing a leak detection device 1b according to an embodiment of the present invention. That is, the detection cable 5b in which the strip-shaped insulator 3b supports the conductors 2b and 2b 'arranged substantially side by side and the pair of lead wires 8b and 8b' provided along both sides of the conductor is supported. This insulator 3b has a plurality of through holes 4b between the conductors 2b and 2b 'for passing the incoming liquid. The impedance value change sensing device 6b is connected to one end of the conductors 2b and 2b ', the terminating resistor 7b is connected to the lead wires 8b and 8b' of the same end, and the conductors 2b and 2b 'are connected to the other ends. And the lead wires 8b and 8b 'are connected to each other and covered with a cover 9b.

In the above-described liquid leakage detection device 1b, since the conductors 2b and 2b ′ are connected to the lead wires 8b and 8b ′ respectively (the right side in the figure), there is no terminating resistor, so that the thickness of the insulator 3b is reduced. It is possible to provide the covering 9b that does not exceed the width or the width, which facilitates insertion and installation in a narrow space. The insulator 3b may be extended and used for the cover 9b.

FIG. 4 is a plan view showing a liquid leakage detection device 1c according to another embodiment of the present invention. That is, the detection cable in which the strip-shaped insulator 3c supports the conductors 2c and 2c 'which are substantially arranged side by side and the pair of lead wires 8c and 8c' which are provided along one side of the conductors. 5c, the insulator 3c has a plurality of through holes 4c between the conductors 2c and 2c 'for passing the incoming liquid. The impedance value change sensing device 6c is connected to one ends of the conductors 2c and 2c ', the terminating resistor 7c is connected to the lead wires 8c and 8c' of the same ends, and the conductors 2c and 2c 'are connected to the other ends thereof. The lead wires 8c and 8c 'are connected to each other and covered with a cover 9c.

It goes without saying that the liquid leakage detection device 1c has the same effect as the liquid leakage detection device 1b, and moreover, the left ends of the lead wires 8c and 8c ′ in the figure are the conductors 2c and 2c ′. Wiring can be done without crossing, facilitating construction.

The present invention is not limited to the above embodiment, and various modifications can be made within the technical concept of the present invention, for example, as shown in the following. A flexible printed circuit board-like detection cable is used that uses printed wiring in which at least two conductors and a pair of lead wires that are substantially separated and arranged side by side are printed on an insulator. A detection cable for a double-sided flexible printed circuit board is used, which has a conductor on the front surface of a strip-shaped insulator and a lead wire on the back surface. A detection cable whose conductor is a comb-shaped conductor is used. Use a sensing cable whose insulation is a mesh or permeable material. A coaxial cable-like detection cable is used in which each of the two conductors is an inner conductor and an outer conductor arranged around the inner conductor. A pair of lead wires is provided so as to be returned along this conductor. A terminating resistor is provided in the impedance value change sensing device.

[0015]

[Effect of the device]

 As described above, according to the present invention, since the terminating resistor is connected to the impedance value change sensing device side of the detection cable, the other end side of this detection cable can be made small, and this makes it easy to place it in a narrow space. It has a unique effect that it can be installed so that it slides in.

[Brief description of drawings]

FIG. 1 is a plan view showing a conventional leak detection device.

FIG. 2 is a side view showing another conventional leak detection device.

FIG. 3 is a plan view showing a liquid leakage detection device according to an embodiment of the present invention.

FIG. 4 is a plan view showing a liquid leakage detection device according to another embodiment of the present invention.

[Explanation of symbols]

1a, 1b, 1c Liquid leakage detection device 2a, 2a ', 2b, 2b', 2c, 2c 'Conductor 3a, 3b, 3c Insulator 4a, 4b, 4c Through hole 5a, 5b, 5c Detection cable 6a Impedance value change detection Device 7a, 7b, 7c Termination resistor 8a, 8a ', 8b, 8b', 8c, 8c 'Lead wire 9b, 9c Cover 10a Protective box

Claims (1)

[Scope of utility model registration request] 1. A detection cable having a structure comprising at least two conductors arranged substantially side by side and a pair of lead wires provided along the conductors, the impedance value between the conductors being changed by an incoming liquid. An impedance value change sensing device is connected between the conductors at the end of the detection cable, and a terminating resistor is connected between the lead wires at the same end, and at the other end of the detection cable, the conductor and the lead wire are connected. A leak detection device characterized in that each is connected.