JP7461164B2 - Liquid Detection Sensor - Google Patents

Description

The present invention relates to a liquid detection sensor equipped with a metal-air battery.

For example, the following patent document discloses a water level sensor that can detect the water level of a river or the like.

In the invention described in Patent Document 1, a reed switch board is provided inside the main pipe, and a reed switch corresponding to the height position of the float is turned on according to the water level of the float. Power to the reed switch board is supplied by a solar panel and a radio board. The radio board is configured with a microcomputer, a radio, and a rechargeable battery. Power from the solar panel is supplied to and stored in the rechargeable battery. The solar panel and the rechargeable battery make up the power supply unit of the water level sensor.

In the invention described in Patent Document 2, a float that floats on water is inserted into a support, and the height of the float floating on the water is detected by a sensor unit to measure the water level. The power supply unit is composed of a power supply Vcc consisting of a battery and a power switch SW consisting of a reed switch.

JP 2018-194363 A JP 2018-189505 A

However, the water level sensors in the inventions described in these patent documents require a rechargeable battery as an external power source, and the battery must be fully charged when measuring the water level. For this reason, in a method in which the rechargeable battery is charged by a solar panel, as in Patent Document 1, depending on the conditions of use, the rechargeable battery may not be fully charged, making it impossible to measure the water level properly. Furthermore, in these patent documents, the battery must be constantly charged regardless of whether or not the water level is being measured, making it difficult to extend its lifespan, and maintenance, etc., is also considered to be necessary.

The present invention has been made in view of this point, and provides a sensor that detects liquid containing water, which can supply generated power to the water level sensor and appropriately detect the water level when measuring the water level. The purpose is to provide.

The liquid detection sensor of the present invention comprises a metal-air battery having an air electrode and a metal electrode, and a water level sensor, wherein the water level sensor is operated by the generated power generated in the metal-air battery when immersed in liquid, the water level sensor has a length in the direction of increase or decrease of the water level corresponding to the measurement range of the water level of the liquid, the water level sensor is positioned so as to be able to come into contact with the liquid, the metal-air battery as a power source generates power by coming into contact with the liquid in which the water level sensor is immersed , the water level sensor is operated by the generated power of the metal-air battery, and is characterized in that the water level of the liquid is measured by coming into contact with the liquid and the water level in which the metal-air battery is immersed is used as the starting water level for measurement .

The present invention further includes a casing having an air chamber and holding the metal air battery, one surface of the air electrode is exposed to the air chamber, and the other surface of the air electrode is exposed to the air chamber. , the metal electrodes may face each other.

In the present invention, the water level sensor can be configured to be supported by the housing.

In the present invention, the housing can be configured to include a liquid chamber having a water supply port for the liquid, and the metal electrode can be disposed in the liquid chamber.

In the present invention, the air electrode and the metal electrode can be configured to face each other with a space between them.

In the present invention, the air electrode and the metal electrode may be configured to face each other with a separator interposed therebetween.

According to the liquid detection sensor of the present invention, the water level sensor can be operated by the power generated by the metal air battery immersed in the liquid, and when measuring the water level, the generated power can be appropriately supplied to the water level sensor. It can be detected with high precision.

FIG. 1 is a longitudinal sectional view of a liquid detection sensor according to a first embodiment. FIG. 2 is a longitudinal cross-sectional view of a liquid detection sensor in a second embodiment. FIG. 3 is a longitudinal cross-sectional view of a liquid detection sensor in a third embodiment.

Hereinafter, one embodiment of the present invention (hereinafter abbreviated as "embodiment") will be described in detail. Note that the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist.

The liquid detection sensor 1 shown in FIG. and. Note that the air electrode 2 and the metal electrode 3 disposed in each metal-air battery 4 are preferably approximately the same size (facing area), although not particularly limited.

As shown in FIG. 1, the metal-air battery 4 is held within a housing 6. The housing 6 is provided with an air chamber 6a and a liquid chamber 6b. As shown in FIG. 1, the upper end of the air chamber 6a is open. A window that penetrates between the air chamber 6a and the liquid chamber 6b is provided below the inner wall 6c that separates the air chamber 6a and the liquid chamber 6b, and the window is closed by the air electrode 2. There is. The air electrode 2 is bonded to the outer frame of the window with an adhesive or the like. When the air electrode 2 is held in the air chamber 6a by the inner wall 6c, one surface 2a of the air electrode 2 is exposed to the air chamber 6a side. Further, the other surface 2b of the air electrode 2 faces the metal electrode 3. In this way, the air chamber 6a is a closed space except for the upper end due to the assembly of the casing 6 and the air electrode 2. Therefore, air fills the air chamber 6a and is in contact with the air electrode 2.

As shown in FIG. 1, the metal electrode 3 is arranged within the liquid chamber 6b. A space is provided in the X direction between the metal electrode 3 and the air electrode 2, and the liquid that has flowed into the liquid chamber 6b can be interposed between the metal electrode 3 and the air electrode 2. As shown in FIG. 1, the lower part of the metal electrode 3 is preferably a free end. By forming the free end in this way, the lower part of the metal electrode 3 can be swung. Therefore, when products are deposited between the air electrode 2 and the metal electrode 3, the metal electrode 3 can be bent, the pressing force caused by the products can be alleviated, and the metal electrode 3 and the air electrode 2 can be Damage can be suppressed.

As shown in FIG. 1, the housing 6 is provided with a water supply port 7 that communicates with the liquid chamber 6b. Liquid is supplied into the liquid chamber 6b through this water supply port 7.

Although not limited to this, the air electrode 2 is configured to include a current collector and a catalyst layer (reaction part). The properties required of the current collector are conductivity to transfer electrons emitted from the metal electrode 3 to the catalyst layer, and air permeability to allow oxygen to pass through. Although the structure of the current collector is not limited, for example, existing ones such as wire mesh or foam metal can be used. Further, the characteristics required of the catalyst layer are hydrophobicity that does not release liquid to the outside, and air permeability that allows oxygen to pass through. Existing materials can be used for the catalyst layer.

The metal electrode 3 is preferably made of magnesium (Mg), Mg alloy, zinc (Zn), Zn alloy, aluminum (Al), or Al alloy. Among these, the metal constituting the metal electrode 3 is more preferably Mg or an Mg alloy.

In the liquid detection sensor 1 shown in FIG. 1, when a liquid containing water is supplied into the liquid chamber 6b, for example, when the metal constituting the metal electrode 3 is Mg, the following occurs on the metal electrode 3 side. The oxidation reaction shown in (1) occurs. Further, in the air electrode 2, a reduction reaction shown in (2) below occurs. Therefore, as a whole, the reaction shown in (3) below occurs and discharge occurs.
(1) 2Mg → 2Mg ²⁺ +4e ^-
(2) O ₂ +2H ₂ O+4e ^- →4OH ^-
(3) 2Mg+O ₂ +2H ₂ O → 2Mg(OH) ₂

Due to the above battery reaction, the metal-air battery 4 starts generating electricity. The power generated by the metal-air battery 4 is then supplied to the water level sensor 5 via a supply line 9. Thereby, when measuring the water level, generated power can be appropriately supplied to the water level sensor 5, and the water level can be detected with high accuracy. In other words, the metal-air battery 4 does not generate electricity in environments other than water level measurement (in which liquid does not flow into the liquid chamber 6b), and a rechargeable battery that must be constantly charged even when water level is not being measured is used. The configuration is different from the previous version. In this way, in this embodiment, the power generated by the metal-air battery 4 is supplied to the water level sensor 5 only when water level measurement is necessary, so that a longer life can be achieved, and No regular maintenance is required. In this embodiment, by installing the liquid detection sensor 1 at the place where you want to measure the water level, water level measurement can be started by the inflow of liquid into the liquid detection sensor 1, and it is not affected by the usage environment. This makes it possible to perform appropriate water level measurements.

Here, the "liquid level" includes, but is not limited to, the water level caused by flooding into rivers, seawater, dams, water tanks, bathtubs, sewage tanks, indoors, and cars. In a usage environment where rain or liquid falls from above, it is preferable to close the upper part of the air chamber 6a while ensuring the supply of air to the air chamber 6a so that rain or liquid does not enter the air chamber 6a. .

The water level sensor 5 can be of any existing type. For example, but not limited to, a capacitance type, float type, electrode type, pressure detection type, optical type, vibration type, ultrasonic type, or laser type water level sensor can be used.

As shown in FIG. 1, when the liquid 8 flows into the liquid chamber 6b of the housing 6, the metal-air battery 4 generates power, and the generated power is supplied to the water level sensor 5. The water level sensor 5 has a length in the water level increase/decrease direction (Y direction) according to the water level measurement range, and the water level sensor 5 can measure the water level of the liquid 8. The metal air battery 4 is arranged below the water level sensor 5, and can ensure a wide measurement range from low water level to high water level. Furthermore, if low water level measurement is not required, measurements can be made from any water level by placing the metal air battery 4 at the water level where you want to start measurement, instead of below the water level sensor 5. possible. The water level can be reported at a remote location by recognizing the water level signal obtained from the water level sensor 5 by wireless notification from a wireless transmitter operated by the power generation of the metal-air battery 4. The wireless method is not limited, and existing methods such as wireless LAN, Bluetooth (registered trademark), Wi-Fi, etc. can be used.

As shown in FIG. 1, the water level sensor 5 can be placed on the side 6d of the housing 6 that holds the metal-air battery 4. Thereby, both the metal air battery 4 and the water level sensor 5 can be held in the common housing 6, the number of parts can be reduced, and the structure can be simplified. Note that in this embodiment, the side portion 6d of the housing 6 has the same length as the water level sensor 5 in the Y direction, but the length of the housing 6 is not limited; The length of the portion 6d may be shorter than the water level measurement range. At this time, it is necessary to configure the air chamber 6a so that no liquid enters it. However, in order to reliably support the water level sensor 5 on the side part 6d of the housing 6, it is preferable that the side part 6d has a length dimension equal to or greater than that of the water level sensor 5.

Moreover, the position of the water supply port 7 is not limited to the position shown in FIG. For example, the water supply port 7 can be provided on the side of the housing 6. Alternatively, by providing the water supply port 7 at a higher position than in FIG. 1, water level measurement can be started only when the water level of the liquid 8 rises to a position comparable to or higher than the water supply port 7. Therefore, low water level measurements can be intentionally excluded. Further, it is preferable that the housing 6 has an air port near the top of the liquid chamber 6b. For example, if the only opening of the liquid chamber 6b is the water supply port 7, it is preferable to provide an air port in the liquid chamber because air exchange will not be possible due to rising water in the river, making it difficult for the liquid 8 to enter the liquid chamber. .

The housing 6 shown in FIG. 1 has both an air chamber 6a and a liquid chamber 6b, but may have a structure in which at least the air chamber 6a is provided. In the second embodiment shown in FIG. 2, the housing 6 has an air chamber 6a with an open upper end. On the other hand, the housing 6 shown in FIG. 2 does not have a liquid chamber 6b surrounded by a wall, and the metal electrode 3 is placed on the outside facing the air electrode 2 placed in the air chamber 6a, with the metal electrode 3 exposed to the outside. In the liquid detection sensor 10 shown in FIG. 2, the liquid 8 comes into direct contact with the metal electrode 3 exposed to the outside, so that power generation of the metal-air battery 4 begins immediately, and it is possible to prevent the occurrence of a detection time lag.

In the third embodiment shown in FIG. 3, a separator 11 is interposed between the air electrode 2 and the metal electrode 3 constituting the second embodiment shown in FIG. 2.

Note that, although not limited to this, the air electrode 2 and the separator 11 and the metal electrode 3 and the separator 11 can be fixed via an adhesive layer. The adhesive layer is preferably provided partially on the edges of the air electrode 2 and the metal electrode 3.

The separator 11 is made of a material that is electrically insulating and ion-permeable. For example, it may be a nonwoven fabric, a woven fabric, a porous thin film, etc.

In FIG. 3, the separator 11 is only interposed between the air electrode 2 and the metal electrode 3, but it is also possible to extend the separator 11 from the state shown in FIG. 3 to the outer surface 3a side of the metal electrode 3.

Further, the support of the laminate structure in which the separator 11 is interposed between the air electrode 2 and the metal electrode 3 may not be the housing 6 shown in FIG. 3. However, the surface of the air electrode 2 opposite to the side facing the metal electrode 3 needs to have a structure in which air is always in contact with the surface.

The metal-air batteries 4 disposed in the liquid detection sensors 1, 10, and 20 of this embodiment self-generate power by contact with the liquid 8, but in order to self-generate power in this way, although it is not necessarily necessary, Preferably, salt is present in the liquid 8. Examples of salts include, but are not limited to, sodium chloride. Therefore, when the liquid 8 is a component that does not contain salt, it is preferable to provide a salt supply means capable of supplying salt into the liquid 8 when the liquid 8 comes into contact with the metal-air battery. For example, as shown in FIG. 3, in a configuration in which a separator 11 is interposed between the air electrode 2 and the metal electrode 3, it is possible to contain salt in the separator 11.

As described above, the liquid level can be detected by using the liquid detection sensors 1, 10, and 20 of this embodiment. In particular, in this embodiment, the water level can be measured using the existing water level sensor 5, and by selecting an appropriate water level sensor 5 according to the intended use, the water level can be detected with high accuracy. be.

Further, in this embodiment, a battery cell is configured with one set of an air electrode 2 and a metal electrode 3, but the metal-air battery 4 can also be configured with a battery unit including a plurality of such battery cells. .

According to the liquid detection sensor of the present invention, when the water level is to be measured, the metal-air battery as a power source generates electricity to operate the water level sensor, allowing appropriate water level measurement to be performed both indoors and outdoors. In the present invention, no preparation or regular maintenance is required to operate the liquid detection sensor, making it easy to use and less susceptible to the effects of the external environment, and allowing accurate water level measurement with a simple structure.

1, 10, 20: Liquid detection sensor 2: Air electrode 2a: Surface 2b: Surface 3: Metal electrode 3a: Outer surface 4: Metal air battery 5: Water level sensor 6: Housing 6a: Air chamber 6b: Liquid chamber 6c: Inner wall Part 6d: Side part 7: Water supply port 8: Liquid 9: Supply line 11: Separator

Claims (6)

A metal-air battery having an air electrode and a metal electrode;
A water level sensor,
The water level sensor is activated by the power generated in the metal-air battery when immersed in liquid,
the water level sensor has a length in a direction in which the water level increases or decreases according to a measurement range of the water level of the liquid, and the water level sensor is positioned so as to be able to come into contact with the liquid;
the metal-air battery as a power source generates electricity by contacting the liquid in which the water level sensor is immersed ;
The water level sensor is powered by the power generated by the metal-air battery, and is in contact with the liquid, measuring the level of the liquid using the water level in which the metal-air battery is immersed as the starting water level for measurement. The liquid detection sensor according to claim 1, further comprising a housing having an air chamber and holding the metal-air battery, one surface of the air electrode being exposed to the air chamber, and the other surface of the air electrode being opposed to the metal electrode. The liquid detection sensor according to claim 2, characterized in that the water level sensor is supported by the housing. 4. The liquid detection sensor according to claim 2, wherein the housing includes a liquid chamber having a water supply port for the liquid, and the metal electrode is disposed in the liquid chamber. The liquid detection sensor according to any one of claims 1 to 4, characterized in that the air electrode and the metal electrode face each other via a space. 5. The liquid detection sensor according to claim 1, wherein the air electrode and the metal electrode face each other with a separator interposed therebetween.

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