JP4317099B2 - Leak sensor and leak detection system - Google Patents

Description

  The present invention relates to a water leakage sensor and a water leakage detection system for detecting water leakage, and more particularly to a water leakage sensor and a water leakage detection system using a chemical battery as a detection mechanism.

In factories and buildings, accidents involving water leaks from circulating cooling water and water pipes can lead to serious situations such as the suspension of business operations. For this reason, in the past, in factories and buildings, water leakage sensors have been installed in places where water leakage is likely to occur or where water leakage must be avoided to monitor the occurrence of water leakage.
Also in the fields of childcare and elderly care, delays in changing diapers have led to reduced work efficiency for caregivers and increased discomfort for newborns and caregivers. For this reason, it has been proposed to provide a diaper with a water leak sensor to detect incontinence at an early stage.

The water leakage sensor used in the scene as described above detects water leakage mainly by monitoring a resistance change and a capacity change that occur at the time of water leakage between two different metal electrodes. Specifically, a current vector between two kinds of electrodes is measured (for example, see Patent Document 1), or a current flowing through two kinds of metal tubes is measured (for example, see Patent Document 2). A leak is detected.
The applicant has not yet found prior art documents related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in this specification.
Japanese Patent Laid-Open No. 5-18849 JP-A-8-166313

However, since the conventional water leakage sensor detects water leakage by energizing the sensor, it is indispensable to supply electric power to the sensor. For this reason, for example, if a large number of sensors are arranged, the electrical wiring becomes complicated, requiring complicated work, and labor and cost are required. Moreover, even if a battery is used as a power supply source in order to avoid complicated construction of electric wiring, it takes time for maintenance such as battery replacement and battery life management, and high cost is inevitable. Furthermore, in the case where the water leakage sensor is disposed in the diaper, it is an essential condition that the cost is low in consideration of circumstances such as disposable.
Therefore, the present invention has been made to solve the above-described problems, and an object thereof is to provide a water leakage sensor and a water leakage detection system that are inexpensive and easy to use.

In order to solve the above problems, water leakage sensor that written to the present invention includes a housing having an opening, a catalyst for reducing the metal electrode and the oxygen which is disposed in the housing electrochemically is A metal electrode having an added carbon electrode, at least an electrolyte disposed between the metal electrode and the carbon electrode, a separator film for preventing a short circuit, and an electronic circuit connected to the metal electrode and the carbon electrode; When the water enters the housing through the opening, the carbon electrode acts as the anode and cathode of the battery due to a chemical change with the aqueous electrolyte solution, and the electronic circuit is activated by the potential difference generated between the metal electrode and the carbon electrode. It is characterized by notifying that water leakage has occurred. When moisture is supplied to the inside of the housing, the electrolyte dissolves and an electrolytic solution is generated. A chemical change occurs between the electrolytic solution, oxygen in the air by the carbon electrode, and the metal electrode, and between the carbon electrode and the metal electrode. A potential difference occurs.

  In the water leakage sensor, the carbon electrode is disposed on a surface of the housing having a plurality of holes formed therein, and moisture disposed on the surface and the opening of the housing excluding the surface provided with the holes. You may make it have further the polymer to absorb.

  In the water leakage sensor, a plurality of water leakage sensors may be electrically connected in series or in parallel.

  In the water leakage sensor, the electronic circuit may be configured by any one of a wireless device that transmits a wireless signal, an acoustic device that generates an alarm sound, and a lighting device that lights a warning lamp.

  The water leakage detection system according to the present invention includes at least one water leakage sensor, at least one detection device that detects the occurrence of water leakage from the water leakage sensor, and the detection device connected by a communication line. It is comprised from the management apparatus which receives the information regarding that the water leak occurred.

  According to the present invention, when water leaks and moisture enters the inside of the housing, a chemical change occurs inside the housing and the electronic circuit is activated by a potential difference generated between the electrodes. Thus, in this invention, it can alert | report that the water leak occurred without the electric power supply from the outside. Thereby, since an electrical wiring and a battery are unnecessary, low cost is realizable. In addition, it is easy to use because there is no need for troublesome electrical wiring and battery replacement.

[First Embodiment]
The first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of a water leakage sensor according to the present embodiment.
The water leakage sensor 1 includes a housing 10 having an opening 10 a on one side surface, a positive electrode 11 disposed inside the upper surface of the housing 10, and a negative electrode 12 disposed inside the bottom surface of the housing 10. A pair of separators 13 and 14 disposed between the positive electrode 11 and the negative electrode 12, an electrolyte 15 disposed between the separators 13 and 14, and electricity disposed on the outer surface of the housing 10. A circuit 16, a conductive wire 17 that connects the electrical circuit 16 and the positive electrode 11, a conductive wire 18 that connects the electrical circuit 16 and the negative electrode 12, and a switch 19 that is disposed on the top surface of the housing 10 and relays the conductive wire 18. The water absorption body 20 that covers the outer surface of the housing 10 and the water conduit 21 that is continuous with the water absorption body 20 and is disposed in the opening 10 a of the housing 10.

  The housing 10 is made of, for example, resin or the like, has a rectangular parallelepiped shape as shown in FIG. 1, and has an opening 10a on one side surface. The shape of the housing 10 is not limited to a rectangular parallelepiped as long as the components constituting the water leakage sensor 1 such as the positive electrode 11, the negative electrode 12, and the electrolyte 15 can be disposed therein. It can be set freely as appropriate.

The positive electrode 11 is made of a material containing manganese dioxide, and is disposed inside the upper surface of the housing 10.
Here, the material of the positive electrode 11 is preferably in the form of fine particles in order to increase the speed of the battery reaction when moisture generated by water leakage flows into the housing.
Manganese dioxide has low electrical conductivity and may have high internal resistance. For this reason, 30-40% carbon powder per weight of the positive electrode as a conductive additive and 10-20% polytetrafluoroethylene (PTFE) or polyvinylidene chloride (PVDF) per weight of the positive electrode as a binder as manganese dioxide powder. A composite electrode that is mixed and molded into a film shape by a roll press or the like may be used as the positive electrode 11.

The negative electrode 12 is made of a material containing zinc, and is disposed inside the bottom surface of the housing 10.
Such a negative electrode 12 may be configured by disposing a sheet-like zinc foil inside the bottom surface of the housing 10. As in the case of the positive electrode 12, a composite electrode in which carbon powder and a binder are mixed with zinc powder may be used.
In this way, the positive electrode 11 is disposed on the top surface of the housing 10 and the negative electrode 12 is disposed on the bottom surface of the housing 10, so that the positive electrode 11 and the negative electrode 12 face each other inside the housing 10. Is done.

The separator 13 is made of a known material having hydrophilicity, and is cut into an appropriate shape and size from a sheet-like material using an appropriate jig such as a punch in accordance with the shape and size of the housing. The separator 14 and the positive electrode 11 that are paired with each other are separated from or in contact with each other, and are disposed inside the housing 10 so as to be substantially parallel to each other.
The separator 14 is made of a known hydrophilic material, and is cut into an appropriate shape and size from a sheet-like material using an appropriate jig such as a punch in accordance with the shape and size of the housing. The separator 13 and the negative electrode 12 that are paired with each other are separated or in contact with each other, and are disposed in the housing 10 so as to be substantially parallel to each other.

Thus, by arranging the separators 13 and 14 between the positive electrode 11 and the negative electrode 12, it is possible to prevent the positive electrode 11 and the negative electrode 12 from coming into contact with each other and causing a short circuit.
For example, the separators 13 and 14 may be disposed inside the housing 10 by, for example, connecting one end of the separators 13 and 14 to the absorber 20 to efficiently introduce moisture into the housing 10. .
As the separators 13 and 14, either a polymer sheet such as polyethylene or polyester, a sheet made of glass fiber, or a composite film including these may be used.

The electrolyte 15 is composed of any of ammonium chloride, potassium hydroxide, or sodium hydroxide, and is disposed between the separators 13 and 14.
Here, the electrolyte 15 is preferably in the form of a fine powder so that the water generated by water leakage can be easily dissolved when flowing into the housing 10.
By disposing the electrolyte 15 between the separators 13 and 14, it is possible to prevent the electrolyte 15, the positive electrode 11 and the negative electrode 12 from contacting and corroding before water leakage.

The amount of the electrolyte 15 is preferably set so that the concentration of the electrolytic solution is 3 mol / l or more when the inside of the housing is filled with moisture due to water leakage. In addition, when the electrolyte 15 can be added in a large amount due to the structure of the casing 10, the electrolyte concentration is preferably about 8 mol / l.
When potassium hydroxide or sodium hydroxide is used as the electrolyte 15, it is desirable to add zinc oxide to the inside of the housing 10 at the same time in order to suppress hydrogen generation due to water decomposition.

The electronic circuit 16 includes an acoustic device such as a buzzer and a speaker, a light emitting device such as an LED (Light Emitting Diode), a communication device that transmits a radio signal, and the like. The electronic circuit 16 is connected to a conductive wire 17 connected to the positive electrode 11 and a conductive wire 18 connected to the negative electrode 12, and electric power generated by water leakage is supplied through these conductive wires 17 and 18, Operate.
The position where the electronic circuit 16 is disposed is not limited to the outside of the upper surface of the housing 10 as long as it is a position that can be connected to the conductors 17 and 18. It can be set freely as appropriate according to the application.

The conducting wire 17 is composed of a copper wire or the like, and is embedded in the housing 10 so as not to contact moisture flowing into the housing 10 due to water leakage. One end is connected to the positive electrode 11 and the other end is connected to the electronic circuit 16. The
The conducting wire 18 is composed of a copper wire or the like, and is embedded in the housing 10 so as not to contact moisture flowing into the housing 10 due to water leakage, with one end connected to the negative electrode 12 and the other end connected to the electronic circuit 16. Is done.

The switch 19 is composed of a known switch, is connected to the conductor 18, and is disposed outside the upper surface of the housing 10 so that it can be operated from the outside of the water leakage sensor 1. By providing this switch 19, the user can control the ON / OFF operation of the electronic circuit 16.
The position where such a switch 19 is disposed is not limited to the upper surface of the housing 10 as long as the user can operate from the outside of the water leakage sensor 1, and the water leakage sensor 1 such as a side surface or a bottom surface of the housing 10. It can be set freely according to the application.

The absorbent body 20 is made of a known absorbent polymer or the like that is used in a paper diaper or the like and has a function of not oozing out when moisture is absorbed inside, and is disposed on the outer surface of the housing 10.
The absorber 20 may not be disposed on the surfaces of the electronic circuit 16 and the switch 19.

  The water conduit 21 is made of a known absorbent polymer or the like used for a disposable diaper or the like, and is arranged so as to be connected to the separators 13 and 14 in the housing 10 through the opening 10 a of the housing 10 continuously with the absorber 20. The

  When moisture is supplied to such a water leakage sensor 1, the moisture is absorbed into the polymer constituting the absorber 20 disposed on the surface of the water leakage sensor 1. This moisture penetrates the inside of the absorber 20 by capillary action and reaches the water conduit 21, and is supplied from the water conduit 21 into the housing 10. The water supplied into the housing 10 dissolves the electrolyte 15 and generates an electrolytic solution. Then, a potential difference is generated between the positive electrode 11 and the negative electrode 12 according to the following chemical formula.

Positive electrode: 2MnO ₂ + 2H ₂ O + 2e ⁻ → 2MnOOH + 2OH ⁻
Negative electrode: Zn + 4OH ⁻ → Zn (OH) ₄ ²⁻ + 2e ⁻
Total reaction: Zn + 2MnO ₂ + 2H ₂ O + 2OH ⁻ → Zn (OH) ₄ ²⁻ + 2MnOOH

  Although depending on the size of the water leakage sensor 1, a voltage of about 1 V, a current of about 1 to 10 mA, that is, a power of about 1 to 10 mW is obtained by this reaction, and the electronic circuit 16 is activated by this power to A warning signal, an alarm such as an alarm, and a warning light such as an LED can be turned on.

  Thus, according to this Embodiment, it can alert | report that the water leak occurred, without supplying electric power from the outside. For this reason, since electric wiring and a battery are unnecessary, cost reduction can be implement | achieved. In addition, it is easy to use because there is no need for troublesome electrical wiring and battery replacement.

The operation time during which the warning signal can be generated can be adjusted according to the characteristics of the place where the sensor is used, depending on the size of the water leakage sensor 1. For example, when a radio signal is generated by the electronic circuit 16, it is possible to send a warning to a maintenance center or the like located far away even in a short time operation and cope with water leakage, so that the water leakage sensor 1 can be downsized. .
On the other hand, when water leakage is detected from the warning light of the electronic circuit 16 by visual inspection of the user or the like, the sensor operating time is set by setting the amounts of the positive electrode 11, the negative electrode 12, and the electrolyte 15 based on the time interval that the user patrols. Can be adjusted.

  Further, the water leakage sensor 1 is semipermanent without deterioration because the constituent materials of the positive electrode 11, the negative electrode 12, and the electrolyte 15 are stable in the air even when moisture does not flow into the water leak sensor 1. It is possible to continue laying.

  Further, when a high-output type high-intensity LED or the like is used as the electronic circuit 16, when the power output is insufficient with one sensor, the water leakage sensor 1 having the electronic circuit 16 does not have a plurality of electronic circuits 16. It becomes possible to operate the water leakage sensor 1 by wiring it in series or in parallel. When a plurality of water leakage sensors 1 are used in this way, the electronic circuit 16 cannot be operated unless the plurality of water leakage sensors 1 are operated, so that malfunction of the water leakage sensor 1 can be prevented.

  In order to quickly detect water leakage, it is desirable to use a wireless communication circuit for the electronic circuit 16 to construct a sensor network that notifies the central management center of water leakage by radio waves or ultrasonic waves. When an acoustic device or a light emitting device is used for the electronic circuit 16, early water leakage is detected by building a sensor network system including a microphone system for detecting a buzzer sound and a monitoring camera system for confirming an optical signal. It becomes possible.

  Moreover, in this Embodiment, by arrange | positioning the absorber 20 outside the housing | casing 10, it can prevent that the electrolyte solution inside the housing | casing 10 leaks outside.

Moreover, in this Embodiment, the threshold value which detects a water leak can be set by adjusting the water absorption amount of the absorber 20, and the capacity | capacitance of the housing | casing 10. FIG. For example, when it is desired to detect water leakage even with a small amount of water, it is possible to detect water leakage even with a small amount of water by reducing the amount of the absorber 20 covering the housing 10 and further reducing the capacity of the housing 10. It becomes.
In addition, in order to distinguish water droplets caused by condensation or the like from leakage and prevent malfunction, the amount of the absorber 20 may be increased. In this way, if a large amount of moisture is not absorbed by the absorber 20, moisture does not flow into the housing 10, so that a malfunction with a small amount of moisture does not occur.

[Example 1]
Examples of the above-described embodiment will be described.
For the positive electrode 11, electric field manganese dioxide (EMD), acetylene black, and PTFE are thoroughly mixed at a weight ratio of 50:35:15, formed into a sheet of 500 μm by a roll press, cut into a circle with a radius of 1 cm, and a titanium mesh The one crimped on top was used. At this time, the amount of EMD contained in the positive electrode 11 was 46 mg.
As the negative electrode 12, a zinc foil having a thickness of 0.1 mm was cut out in the same shape as the positive electrode and pressure-bonded onto a titanium mesh.
The positive electrode 11 and the negative electrode 12 were fixed by spot welding to a PTFE casing 10 having a capacity of about 10 ml. At this time, the positive electrode 11 and the negative electrode 12 are welded to the housing 10 so as to be connected to the conductive wires 17 and 18 made of copper wire disposed in the housing 10.

Potassium hydroxide is used for the electrolyte 15, and 0.45 g of potassium hydroxide powder is adjusted to the shape of the casing 10 so that the concentration of the electrolyte is about 8 mol / l when the moisture fills the inside of the casing 10. It was sandwiched between two separators 13 and 14 made of a polymer material appropriately cut.
For the absorbent body 20 and the water conduit 21, a water-absorbing polymer (0.5 g) used in commercially available paper diapers was used and attached to the housing 10 with a known adhesive. This polymer performance has the ability to absorb 100 ml of moisture per gram of polymer. Therefore, the absorber 20 and the water conduit 21 have a water absorption capacity of 50 ml.
Further, an electronic buzzer (manufactured by Star Co., MMB-01, required power 3.4 mW) was used for the electronic circuit 16.

  In order to confirm the operation of the water leakage sensor 1, 60 ml of water was gradually absorbed by the water absorbing body 20, and confirmation of buzzer sound by the electronic circuit 16 at this time and changes in current and voltage were monitored. The results are shown in Table 1.

When the supply of moisture to the absorber 20 was started, the water leakage sensor 1 of this example immediately generated a buzzer sound. The volume of the buzzer sound fluctuated for about 2 to 3 minutes from the start of ringing, but after that, it ringed at a stable volume. This is presumably because the degree of penetration of the electrolytic solution into the positive electrode 11 and the negative electrode 12 and the initial concentration of the electrolytic solution were uneven.
The buzzer sounded for 4 hours, and the utilization efficiency of EMD was as high as about 90%. Further, leakage of the potassium hydroxide aqueous solution did not occur from the inside of the housing 10.

  Thus, it was confirmed that the water leakage sensor 1 of the present example does not require electrical wiring and can operate for 4 hours.

  In the present embodiment, silver oxide may be used for the positive electrode 11, zinc for the negative electrode 12, and ammonium chloride, potassium hydroxide, or sodium hydroxide may be used for the electrolyte 15. Even if it does in this way, it becomes possible to operate a water leak sensor, without electrical wiring.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a cross-sectional view showing the configuration of the water leakage sensor according to the present embodiment.
The water leakage sensor 2 includes a housing 30 having an opening 30a on one side surface and a plurality of holes 30b provided on the upper surface, a positive electrode 31 disposed inside the upper surface of the housing 30, and a housing 30. , A pair of separators 33, 34 disposed between the positive electrode 31 and the negative electrode 32, an electrolyte 35 disposed between the separators 33, 34, and a housing. An electrical circuit 36 disposed outside the upper surface of the body 30, a conductive wire 37 connecting the electrical circuit 36 and the positive electrode 31, a conductive wire 38 connecting the electrical circuit 36 and the negative electrode 32, and a side surface of the housing 30. A switch 39 that relays the conductive wire 38, a water absorber 40 that covers the outer surface of the housing 30, and a water conduit 31 that is continuous with the water absorber 40 and disposed in the opening 30 a of the housing 30. Have.

The housing 30 is made of, for example, resin or the like, has a rectangular parallelepiped shape as shown in FIG. 2, and has an opening 30a on one side surface. A plurality of holes 30 b that are through holes are provided on the upper surface of the housing 30.
The shape of the housing 30 is not limited to a rectangular parallelepiped as long as the components constituting the water leakage sensor 2 such as the positive electrode 31, the negative electrode 32, and the electrolyte 35 can be disposed therein. It can be set freely as appropriate.

The positive electrode 31 is composed of a gas diffusion electrode (hereinafter referred to as an air electrode) mainly composed of carbon, and is disposed on the upper surface of the housing 30 provided with a plurality of holes 30b. Such a positive electrode 31 uses oxygen in the air as an active material, and reacts oxygen in the air with the electrolyte in the housing 30. As described above, a plurality of holes 30b, which are through holes, are provided on the upper surface of the housing 30, and the positive electrode 31 is disposed inside the upper surface. Thereby, the air outside the housing 30 is conveyed to the vicinity of the positive electrode 31.
In addition, it is desirable to add an oxygen reduction catalyst to the positive electrode 31 so that the reaction between oxygen and the electrolyte proceeds smoothly. As the catalyst, a noble metal such as platinum or ruthenium, an organometallic complex such as cobalt porphyrin, a metal oxide such as manganese oxide or a perovskite oxide, or the like can be used.
Such a positive electrode 31 can be produced by mixing carbon, a catalyst, and PTFE or PVDF as a binder and hot pressing.

The negative electrode 32 is made of a material containing any of zinc, aluminum, iron, and magnesium, and is disposed inside the bottom surface of the housing 10.
The negative electrode 32 is preferably made of zinc in consideration of cost and stability in the electrolytic solution. Such a negative electrode 32 can be manufactured by a method equivalent to that of the negative electrode 12 of the first embodiment.
As described above, the positive electrode 31 is disposed on the upper surface of the housing 30 and the negative electrode 32 is disposed on the bottom surface of the housing 10, so that the positive electrode 31 and the negative electrode 32 face each other inside the housing 30. Is done.

The separator 33 is made of a known material having hydrophilicity, and is cut into an appropriate shape and size from a sheet-like material using an appropriate jig such as a punch in accordance with the shape and size of the housing. It is disposed inside the housing 30 so as to be separated from or in contact with the paired separator 34 and the positive electrode 31 and to be substantially parallel to each other.
The separator 34 is made of a known material having hydrophilicity, and is cut out from a sheet-like material into an appropriate shape and size using an appropriate jig such as a punch according to the shape and size of the housing. In other words, the separator 33 and the negative electrode 32 that are paired with each other are separated from or in contact with each other and are substantially parallel to each other.

Thus, by arranging the separators 33 and 34 between the positive electrode 31 and the negative electrode 32, it is possible to prevent the positive electrode 31 and the negative electrode 32 from contacting and short-circuiting.
The separators 33 and 34 are disposed in the housing 30 by, for example, connecting one end of the separators 33 and 34 to the absorber 40 so that moisture is efficiently introduced into the housing 30. Is desirable.
As the separators 13 and 14, either a polymer sheet such as polyethylene or polyester, a sheet made of glass fiber, or a composite film including these may be used.

The electrolyte 35 is made of any of ammonium chloride, potassium hydroxide, or sodium hydroxide, and is disposed between the separators 33 and 34.
Here, the electrolyte 35 is preferably in the form of a fine powder so that the water generated by water leakage can be easily dissolved when flowing into the housing 30.
By disposing the electrolyte 35 between the separators 33 and 34, it is possible to prevent the electrolyte 35 from contacting the positive electrode 31 and the negative electrode 32 before being leaked and corroding.

The amount of the electrolyte 35 is desirably set so that the concentration of the electrolytic solution is 3 mol / l or more when the inside of the housing is filled with moisture due to water leakage. In addition, when the electrolyte 35 can be added in a large amount due to the structure of the housing 30, the electrolyte concentration is preferably about 8 mol / l.
When potassium hydroxide or sodium hydroxide is used as the electrolyte 35, it is desirable to add zinc oxide to the inside of the housing 30 at the same time in order to suppress hydrogen generation due to water decomposition.

The electronic circuit 36 includes an acoustic device such as a buzzer and a speaker, a light emitting device such as an LED, a communication device that transmits a radio signal, and the like. The electronic circuit 36 is connected to a conductive wire 37 connected to the positive electrode 31 and a conductive wire 38 connected to the negative electrode 32, and electric power generated by water leakage is supplied through these conductive wires 37 and 38. Operate.
The position where the electronic circuit 36 is disposed is not limited to the outside of the upper surface of the housing 30 as long as it is a position that can be connected to the conductors 37 and 38. It can be set freely as appropriate according to the application.

The conducting wire 37 is composed of a copper wire or the like, and is embedded in the housing 30 so as not to come into contact with moisture flowing into the housing 30 due to water leakage. One end is connected to the positive electrode 31 and the other end is connected to the electronic circuit 36. The
The conducting wire 38 is composed of a copper wire or the like, and is embedded in the housing 30 so as not to contact moisture flowing into the housing 30 due to water leakage. One end is connected to the negative electrode 32 and the other end is connected to the electronic circuit 36. Is done.

The switch 39 is composed of a known switch, is connected to the conducting wire 38, and is disposed outside the side surface of the housing 30 so as to be operable from the outside of the water leakage sensor 2. By providing the switch 39, the user can control the ON / OFF operation of the electronic circuit 36.
The position where such a switch 39 is disposed is not limited to the side surface of the housing 30 as long as the user can operate from the outside of the water leakage sensor 2, and the water leakage sensor 2 such as the upper surface or the bottom surface of the housing 10. It can be set freely according to the application.

The absorbent body 40 is made of a known absorbent polymer or the like that is used in a paper diaper or the like and has a function of not oozing out when moisture is absorbed inside, and is disposed on the outer surface of the housing 30.
Here, the absorber 40 is disposed on the outer surface of the housing 30 so as not to block the hole 30a provided on the upper surface of the housing 30, for example, not disposed on the upper surface of the housing 30. .
Further, the absorber 40 may not be disposed on the surfaces of the electronic circuit 36 and the switch 39.

  The water conduit 41 is made of a known absorbent polymer or the like used for a disposable diaper or the like, and is arranged so as to be connected to the separators 33 and 34 inside the housing 30 from the opening 30a of the housing 30 continuously with the absorber 40. The

When moisture is supplied to such a water leakage sensor 2, the water is absorbed into the polymer constituting the absorber 40 disposed on the surface of the water leakage sensor 2. The moisture penetrates into the absorber 40 by capillary action, reaches the water conduit 41, and is supplied from the water conduit 41 into the housing 30. The water supplied to the inside of the housing 30 dissolves the electrolyte 35 and generates an electrolytic solution. Then, a potential difference is generated between the positive electrode 31 and the negative electrode 32 according to the following chemical formula.
The following chemical formula shows the reaction when zinc is used for the negative electrode 32.

Positive electrode: O ₂ + 2H ₂ O + 4e ⁻ → 4OH ⁻
Negative electrode: 2Zn + 8OH ⁻ → 2Zn (OH) ₄ ²⁻ + 4e ⁻
Total reaction: 2Zn + O ₂ + 2H ₂ O + 4OH ⁻ → 2Zn (OH) ₄ ²⁻

  Although depending on the size of the water leakage sensor 1, a voltage of about 1 V, a current of about 1 to 10 mA, that is, a power of about 1 to 10 mW is obtained by this reaction, and the electronic circuit 36 is activated by this power to A warning signal, an alarm such as an alarm, and a warning light such as an LED can be turned on.

  By having the configuration as described above, the present embodiment can have the same operational effects as the first embodiment.

  Further, in this embodiment, oxygen in the air is used as an active material, so that it is possible to operate for a long time even in the same volume as in the first embodiment. Therefore, the water leakage sensor 2 according to the present embodiment is suitable for use when a warning signal due to water leakage is issued for a long time.

In the present embodiment, in order to allow the reaction to proceed smoothly, oxygen in the air is always supplied from the hole 30b into the housing 30 at a stable speed, and moisture from the hole 30b into the housing 30. It is necessary to prevent intrusion. For this reason, in the present embodiment, a configuration is adopted in which the hole 30b is disposed on the top surface of the housing 30, the absorber 40 is disposed on the bottom surface and the side surface of the housing 40, and water leakage is detected from the side surface and bottom surface of the housing 30. . With this configuration, in the present embodiment, air is stably supplied into the housing 30 from the hole 30b, so that the water repellent coat may be applied to the upper surface of the housing 30 at this time. . As a result, it is possible to prevent moisture from blocking the hole 30b and intrusion of moisture from the hole 30b into the housing 30.
The electronic circuit 36 is preferably disposed at a position away from the housing 30 by extending the upper portion of the housing 30 or the conductive wire 37 or 38.

[Example 2]
Examples of the above-described embodiment will be described.
For the positive electrode 31, a perovskite oxide (La _0.6 Sr _0.4 MnO ₃ ), ketjen black, and PTFE are mixed well at a weight ratio of 50:35:15, and hot-pressed onto a titanium mesh with a radius of 1 cm. What was produced was used.
As the negative electrode 32, a powder obtained by pressing 100 mg of zinc powder on a titanium mesh was used.
Such positive electrode 31 and negative electrode 32 were fixed by spot welding to a PTFE casing 30 having a capacity of about 10 ml. At this time, the positive electrode 31 and the negative electrode 32 are welded to the housing 30 so as to be connected to the conductive wires 37 and 38 made of copper wire disposed in the housing 30.

For the electrolyte 35, potassium hydroxide is used, and 0.45 g of potassium hydroxide powder is adjusted to the shape of the casing 30 so that the concentration of the electrolytic solution is about 8 mol / l when moisture fills the inside of the casing 30. It was sandwiched between two separators 33 and 34 made of a polymer material appropriately cut.
For the absorber 40 and the water conduit 41, a water-absorbing polymer (0.4 g) used in commercially available paper diapers was used and attached to the housing 30 with a known adhesive. This polymer performance has the ability to absorb 100 ml of moisture per gram of polymer. Therefore, the absorber 20 and the water conduit 21 have a water absorption capacity of 40 ml.
In the present embodiment, unlike the first embodiment, a plurality of holes 30b are formed on the upper surface of the housing 30, and oxygen is sent to the air electrode. For this reason, the absorber 40 was affixed on the side surface and bottom surface of the housing 30. In addition, a known water repellent coating agent was applied to the upper surface of the housing 30 in order to prevent water from entering the holes 30b.
A commercially available LED element was used for the electronic circuit 16. Other experimental methods are the same as in Example 1.

  In order to confirm the operation of the water leakage sensor 2, 60 ml of urine was gradually absorbed by the water absorbing body 20, and confirmation of light emission of the LED element by the electronic circuit 16 and changes in current and voltage were monitored. The results are shown in Table 2.

  The operation time of the water leakage sensor 2 of the present embodiment depends on the filling amount of zinc because air is always supplied. In the water leakage sensor 2 of this example, the utilization efficiency of zinc was 70%, which is a low value compared to Example 1, but a long-time operation of 18.5 hours was confirmed. In addition, leakage of the sodium hydroxide aqueous solution from the inside of the housing 30 did not occur.

  Thus, it was confirmed that the water leakage sensor 2 of the present example does not require electrical wiring and can operate for a long time of 18.5 hours.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a cross-sectional view showing the configuration of the water leakage sensor according to the present embodiment.
The present embodiment is a water leakage sensor that can be used repeatedly unlike the water leakage sensor for disposable use shown in the first and second embodiments, and the water leakage sensor 1 of the first embodiment is the same as the water leakage sensor 1 of the first embodiment. It is an improvement. Therefore, in the present embodiment, the same reference numerals and names are assigned to the same components as those in the first embodiment, and description thereof is omitted as appropriate.

  The water leakage sensor 3 includes a housing 50 having a bottom surface 50a opened, a cartridge 51 that is disposed inside the housing 50 and has a housing 51a having an opening 51a on the bottom surface, and is disposed inside the top surface of the cartridge 51. A positive electrode 11, a negative electrode 12 disposed inside the bottom surface of the cartridge 51, and a pair of separators 13 and 14 made of a polymer material disposed between the positive electrode 11 and the negative electrode 12 and cut into an appropriate shape, The electrolyte 15 disposed between the separators 13, 14, the electric circuit 16 disposed outside the upper surface of the housing 50, the conducting wire 17 connecting the electric circuit 16 and the positive electrode 11, and the electric circuit 16 and the negative electrode 12, a switch 19 disposed on the upper surface of the housing 50 for relaying the conductive wire 18, a water absorbent 20 covering the bottom surface of the cartridge 51, and a continuous connection with the water absorbent 20. And a headrace 21 disposed in the cartridge 51 and the opening 51a and.

  The housing 50 is made of, for example, resin or the like, and has a rectangular parallelepiped shape with an open bottom surface 50a as shown in FIG.

The cartridge 51 is made of, for example, resin or the like, has a rectangular parallelepiped shape as shown in FIG. 3, and an opening 51a is formed at an arbitrary location near the side surface of the bottom surface.
Such a cartridge 51 is disposed inside the housing 50 by being inserted into the housing 50 with the upper surface facing the bottom surface of the housing 50.

The conducting wire 17 includes a conducting wire 17 a provided in the housing 50 and a conducting wire 17 b provided in the cartridge 51. The conducting wire 17a and the conducting wire 17b are disposed in the housing 50 or the cartridge 51 so as to be connected to each other when the cartridge 51 is disposed in the housing 50.
The conducting wire 18 includes a conducting wire 18 a provided in the housing 50 and a conducting wire 18 b provided in the cartridge 51. The conducting wire 18a and the conducting wire 18b are disposed in the housing 50 or the cartridge 51 so as to be connected to each other when the cartridge 51 is disposed in the housing 50.

  The absorbent body 20 is made of a known absorbent polymer or the like that is used in a paper diaper or the like and has a function of not oozing out when moisture is absorbed inside, and is disposed outside the bottom surface of the cartridge 51.

  The water guide channel 21 is made of a known absorbent polymer or the like used for a paper diaper or the like, and is arranged so as to be connected to the separators 13 and 14 in the cartridge 51 through the opening 51 a of the cartridge 51 continuously with the absorber 20.

Thus, in the water leakage sensor 3 according to the present embodiment, the positive electrode 11, the negative electrode 12, the separators 13 and 14, the electrolyte 15, the absorber 20, and the water conduit 21 are disposed in the cartridge 51. It can be removed from the body 50.
The water leak sensor shown in the first and second embodiments cannot be reused as a water leak sensor after moisture has entered the inside of the housing and once the water leak has been detected. In contrast, the water leakage sensor 3 according to the present embodiment can detect water leakage again by replacing the cartridge 51 even when water leakage is detected. As a result, the electronic circuit 16 and the switch 19 arranged in the housing 50 can be reused, so that the cost can be reduced.

Next, a water leakage detection system using the above-described water leakage sensor will be described with reference to FIG. FIG. 4 is a diagram illustrating the configuration of the water leakage detection system.
The water leakage detection system 4 includes a centralized management center 5 that manages the entire system, and a wireless device 6, a sound collection device 7, a monitoring camera 8, and a wireless device 6 that are connected to the centralized management center 5 by radio or wire. A water leakage sensor 1a to be monitored, a water leakage sensor 1b to be monitored by the sound collecting device 7, and a water leakage sensor 1c to be monitored by the monitoring camera 8 are configured.
In FIG. 4, the water leakage sensor 1 described in the first embodiment is applied to the water leakage sensors 1a, 1b, and 1c, but the water leakage sensors 2 and 3 described in the second and third embodiments are applied. You may apply.

The centralized management device 5 is connected to the wireless device 6, the sound collection device 7, and the monitoring camera 8 by wireless or wired, and receives centralized management when receiving information on water leakage from the wireless device 6, the sound collection device 7, and the monitoring camera 8. The user is warned by stopping the operation of the device corresponding to the water leakage location in the system to which the device 5 is applied or by displaying on the display device that the water leakage has occurred.
Such a centralized management device 5 includes an arithmetic device such as a CPU, a memory, a storage device such as an HDD, a wireless device 6, a sound collecting device 7, and an I / F device that transmits and receives various information to and from the monitoring camera 8, a keyboard, and a mouse. Computer equipped with a display device such as CRT (Cathode Ray Tube), LCD (Liquid Crystal Display), FED (Field Emission Display) or organic EL (Electro Luminescence), etc., and a program installed on this computer Each function unit of the centralized management device 5 is realized by controlling the hardware device by a program, that is, by cooperating hardware resources and software.

When the wireless device 6 receives a wireless signal indicating that water leakage has occurred from the water leakage sensor 1a, the wireless device 6 notifies the centralized management device 5 that water leakage has occurred. At this time, the wireless device 6 may transmit information indicating the position of the wireless device 6 or the water leakage sensor 1a to the centralized management device 5.
When the sound collecting device 7 detects an alarm sound indicating that water leakage has occurred from the water leakage sensor 1b, the sound collecting device 7 notifies the centralized management device 5 that water leakage has occurred. At this time, the sound collecting device 7 may transmit information indicating the position of the sound collecting device 7 or the water leakage sensor 1b to the centralized management device 5.
When the monitoring camera 8 detects a warning light indicating that water leakage has occurred from the water leakage sensor 1c, the monitoring camera 8 notifies the central management device 5 that water leakage has occurred. At this time, the monitoring camera 8 may transmit information indicating the position of the monitoring camera 8 or the water leakage sensor 1c to the central management device 5.

The water leakage sensor 1 a includes a wireless transmitter as the electronic circuit 16, and transmits a wireless signal indicating that water leakage has occurred when moisture enters the housing 10 and power is generated.
In addition, as shown in FIG. 4, the leak sensor 1a may connect three same leak sensors 1a in series. Thus, by connecting a plurality of water leakage sensors, it is possible to generate electric power according to the standard of the electronic circuit 16.

  The water leakage sensor 1 b includes an electronic buzzer as the electronic circuit 16, and generates a buzzer sound when water enters the housing 10 and power is generated.

  The water leakage sensor 1c includes an LED element as the electronic circuit 16, and turns on the LED element when water enters the housing 10 and power is generated.

  In the water leakage detection system 4 having such a configuration, when any of the water leakage sensors 1a to 1c detects water leakage and performs a wireless signal, a buzzer sound, or a light lighting operation, these operations or the wireless signal are transmitted to the wireless device 6, Sound collecting device 7 or surveillance camera 8 detects. The wireless device 6, the sound collection device 7, or the monitoring camera 8 transmits information regarding the occurrence of water leakage, information regarding the position where water leakage occurred, and the like to the central management device 5. Thereby, the centralized management apparatus 5 detects the occurrence of water leakage and the location of the water leakage.

  Such a water leakage detection system 4 does not use any electrical wiring for the water leakage sensors 1a to 1c, so that it is possible to install the water leakage sensors in locations where there is a risk of water leakage in large quantities.

  In the first to third embodiments described above, the electrode and the electrolyte may be combined so as to function as a secondary battery.

It is sectional drawing which shows the structure of the water leak sensor concerning 1st Embodiment. It is sectional drawing which shows the structure of the water leak sensor concerning 2nd Embodiment. It is sectional drawing which shows the structure of the water leak sensor concerning 3rd Embodiment. It is a figure explaining composition of a water leak detection system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2, 3 ... Water leak sensor, 4 ... Water leak detection system, 5 ... Central control apparatus, 6 ... Wireless apparatus, 7 ... Sound collector, 8 ... Surveillance camera 10, 30, 50 ... Case, 10a, 30a ... Opening 11, 31, ... positive electrode, 12, 32 ... negative electrode, 13, 14, 33, 34 ... separator, 15, 35 ... electrolyte, 16, 36 ... electric circuit, 17, 18, 17a, 17b, 18a, 18b, 37 , 38 ... Conductor, 19, 39 ... Switch, 20, 40 ... Absorber, 21, 41 ... Water conduit, 30b ... Hole, 51 ... Cartridge, 51a ... Opening.

Claims (5)

A housing having an opening;
A metal electrode disposed in the casing and a carbon electrode to which a catalyst for electrochemically reducing oxygen in the atmosphere is added ;
An electrolyte disposed at least between the metal electrode and the carbon electrode ;
A separator film having hydrophilicity disposed between the electrolyte and the electrode;
An electronic circuit connected to the metal electrode and the carbon electrode,
The metal electrode and the carbon electrode, when moisture in the housing from the front Symbol opening enters acts as the anode and cathode of the battery by a chemical change in an aqueous solution of the electrolyte,
The electronic circuit is activated by a potential difference generated between the metal electrode and the carbon electrode to notify that a water leak has occurred. The housing is disposed on the surface and the opening of, and further have the polymer to absorb moisture,
The carbon electrode is disposed on a surface formed with a plurality of holes in the housing inside the housing,
The polymer, water leakage sensor according to claim 1, characterized in that the holes are disposed on the surface and the opening of the housing excluding the surface provided. The water leakage sensor according to claim 1 or 2, wherein a plurality of water leakage sensors are electrically connected in series or in parallel . It said electronic circuit is a wireless device that transmits a radio signal, any one of claims 1 to 3, characterized in that consists of any of the lighting device for lighting a sound device and a warning light to generate an alarm sound water leakage sensor according to. At least one water leakage sensor according to any one of claims 1 to 4,
At least one detection device for detecting the occurrence of water leakage from the water leakage sensor;
A management device connected to the detection device via a communication line and receiving information on the occurrence of water leakage from the detection device;
Leak detection system, characterized in that composed.

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