JP2017083240A - Moisture detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a moisture detector capable of easily cleaning a part for detecting capacitance even when the part gets dirty.SOLUTION: A moisture detector 1 comprises: a conductive member 10 arranged to cover a bottom of a device 2; a capacitance sensor 11 for detecting a change in capacitance of an electrode plate 110 in a non-contact manner; and a control part 12 for detecting water leakage from the device 2 from a change in an output of the capacitance sensor 11 generated when the conductive member 10 is grounded due to the water leakage. By separately arranging the conductive member 10 and the capacitance sensor 11, surfaces of the conductive member 10 and the capacitance sensor 11 can be easily cleaned.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a technique for detecting moisture using electrostatic capacity.

  It has been practiced to prevent serious accidents by installing water detection sensors that detect water in locations where there is a concern about the occurrence of water leaks. Water leaks may occur from the joints of pipes installed in the building, but may also occur from equipment installed in the building.

  In the case of detecting a water leak generated from a device installed in a building, it is necessary to incorporate a moisture detection sensor for detecting moisture in the device. For example, in Patent Document 1, a washing machine incorporating a moisture detection sensor is required. It is disclosed.

  The moisture detection sensor according to Patent Document 1 includes a plurality of electrodes facing each other on the surface of an insulating plate, and a hydrophilic or water-absorbing synthetic fiber is adhered and pasted onto the surface of the insulating plate including the electrodes. The water is detected by taking advantage of the fact that the electrical resistance between the electrodes is remarkably reduced when water is attached to the synthetic fiber. The moisture detection sensor according to Patent Document 1 detects moisture by using a change in electrical resistance. However, as in Patent Document 2, moisture can be detected from a change in capacitance between two electrodes. .

JP-A-7-229867 JP 2002-357582 A

  If the moisture detected by the moisture detection sensor does not contain many impurities, even if the moisture detection sensor detects moisture, the water attached to the electrode of the moisture detection sensor dries and the moisture is detected after the moisture is detected. A detection sensor can be used. However, in the case of water that contains a lot of impurities, if this water adheres to the electrode of the moisture detection sensor, the impurities remain on the electrode of the moisture detection sensor even if the water attached to the electrode of the moisture detection sensor dries. The moisture detection sensor may not operate normally after It is sufficient that the electrode of the moisture detection sensor can be cleaned. However, the conventional moisture detection sensor is usually formed by integrating a pair of electrodes or a plurality of electrodes and is connected to the control device of the device. If it does not work, it will necessitate complicated repairs or replacement of the equipment.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a moisture detection device that can be easily cleaned even if a portion where the capacitance is detected becomes dirty.

  The present invention that solves the above-described problems includes a conductive member disposed so as to cover the bottom surface of a device, a capacitance sensor that detects a change in capacitance of a built-in electrode plate in a non-contact manner, A moisture detection apparatus comprising a control unit for detecting water leakage of the device from a change in output of the capacitance sensor caused by grounding the conductive member due to leakage. In the present invention, when a film coated with conductive ink is used for the conductive member, the conductive member can be manufactured at low cost.

  In the moisture detection device according to the present invention, the conductive member is installed separately from the capacitance sensor that detects a change in capacitance, so that water containing a large amount of water leaks and the impurity is conductive. Even if it adheres to the surface of a member or a capacitance sensor, the surface of the conductive member or the capacitance sensor can be easily cleaned. In addition, since the moisture detection device according to the present invention detects the leakage of the equipment by utilizing the fact that the conductive member is grounded due to the leakage of water, it is only necessary to arrange the conductive member so as to cover the bottom surface of the equipment. , It is possible to detect water leaks from any location rather than a specific location.

The figure explaining the apparatus which installed the moisture detection apparatus which concerns on this embodiment. The block diagram of the moisture detection apparatus which concerns on this embodiment. The figure explaining operation | movement of the moisture detection apparatus which concerns on this embodiment.

  From here, preferred embodiments of the present invention will be described. The following description is not intended to limit the technical scope of the present invention, but is provided to aid understanding.

  FIG. 1 is a diagram for explaining a device 2 in which a moisture detection device 1 according to the present embodiment is installed. In the device 2 in which the moisture detection device 1 according to the present embodiment is installed, the water supply port 2a is provided on the upper surface and the drain port 2b is provided on the lower side surface, and the device 2 is grounded in the present embodiment.

  The moisture detection device 1 according to the present embodiment is a device installed in the device 2 so as to detect water leakage from the bottom surface of the device 2 so as to cover the bottom surface of the device 2 as shown in FIG. A conductive member 10 disposed; a capacitance sensor 11 that detects a change in capacitance in a non-contact manner; and a controller 12 that determines the occurrence of water leakage based on the output of the capacitance sensor 11. In the embodiment, the control unit 12 is connected to a speaker 13 that issues an alarm notifying the occurrence of water leakage.

  The conductive member 10 of the moisture detecting device 1 according to the present embodiment is a conductive member. In FIG. 1, a rectangular conductive member 10 larger than the size of the floor surface of the device 2 is installed on the floor surface of the device 2. doing. The surface of the conductive member 10 in contact with water needs to have conductivity, but the conductive member 10 does not have to be made of metal. For example, an anchor coating and a conductive ink (carbon) coating are applied to a PET film of 1888 μm. What has been obtained can be used for the conductive member 10.

  FIG. 2 is a block diagram of the moisture detection apparatus 1 according to the present embodiment. As described above, the moisture detection device 1 according to the present embodiment includes the control member 12 to which the conductive member 10, the capacitance sensor 11, and the speaker 13 are connected. The capacitance sensor 11 is an electrode plate. 110 and an electric circuit 111 are built in, and the capacitance sensor 11 and the control unit 12 are connected by a cable 14.

  The electric circuit 111 of the capacitance sensor 11 includes a circuit that generates an electric field using the electrode plate 110, a circuit that converts a change in capacitance between the conductive member 10 and the electrode plate 110 into an electric signal, and the like. Then, the capacitance sensor 11 converts the change in capacitance between the conductive member 10 and the electrode plate 110 into an electric signal and outputs it to the control unit 12. As such a capacitive sensor 11, for example, a known capacitive proximity sensor used for detecting the presence or absence of liquid or solid in a container can be used. If used, the length d between the conductive member 10 and the electrode plate 110 of the capacitance sensor 11 can be set to about 20 mm.

  The control unit 12 of the moisture detection device 1 according to the present embodiment is a function realized using a PLC (Programmable Logic Controller), and the control unit 12 according to the present embodiment outputs the output of the capacitance sensor 11 as follows: When the threshold value set in advance in the capacitance sensor 11 is exceeded, a logic for causing the speaker 13 to send an alarm that indicates a water leak is incorporated.

  FIG. 3 is a diagram for explaining the operation of the moisture detection device 1 according to the present embodiment. FIG. 3A is a diagram illustrating a case where no water leakage occurs. When water leakage does not occur from the pipe 2c in the device 2, the conductive member 10 and the device 2 are not electrically connected, and the conductive member 10 is not grounded. The output is low level 11a. FIG. 3B is a diagram for explaining a case when water leakage occurs in the device 2. When water leaks from the pipe 2c in the device 2, the conductive member 10 and the device 2 are electrically connected by the water leaked from the device 2, and the grounded device 2 or the pipe 2c of the device 2 is connected. Since the conductive member 10 is grounded, the output of the capacitance sensor 11 changes to a level 11b higher than the level 11a when there is no water leakage. Therefore, if the threshold is determined based on the output of the capacitance sensor 11 when the conductive member 10 is grounded, the control unit 12 of the moisture detection device 1 can determine the water content of the device 2 from the output of the capacitance sensor 11. Leakage can be judged.

DESCRIPTION OF SYMBOLS 1 Moisture detection apparatus 10 Conductive member 11 Capacitance sensor 110 Electrode plate 111 Electric circuit 12 Control part 2 Apparatus

Claims (2)

  A conductive member arranged to cover the bottom surface of the device, a capacitance sensor that detects a change in capacitance of the built-in electrode plate in a non-contact manner, and the conductive member is grounded due to water leakage A moisture detection apparatus comprising a control unit that detects water leakage of the device based on a change in the output of the capacitance sensor generated in step (b). The moisture detecting device according to claim 1, wherein a film coated with conductive ink is used for the conductive member.

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