KR101816636B1 - Water level sensing system of apparatus - Google Patents

Abstract

The present invention relates to a water level sensing system for a device, comprising: a water level sensing system for a device having a container capable of containing a liquid, wherein the liquid in the container or the container is grounded, And sensing the water level in accordance with the capacitance between the grounded container or the liquid inside the container and the single electrode sensor unit, wherein the ground level sensing system comprises: And the single-electrode sensor unit is used as another electrode, the capacitance between the grounded container and the single-electrode sensor unit can be measured according to the height of the liquid contained in the container, and the water level can be sensed so that the measurement object is connected to the ground It is possible to provide a water level sensing system capable of sensing a change in capacitance.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a water level sensing system,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a water level sensing system of an apparatus, and more particularly, to a water level sensing system of an apparatus having a liquid containing container.

In general, a water level sensor is used in a device that uses water such as a washing machine, a dishwasher, a water purifier, a humidifier, a bidet, and a boiler. In a manufacturing process of a semiconductor, a device using a liquid, such as a chemical, Liquid level sensors have been used, especially in the storage tanks of such solutions.

Such a water level sensor can be measured by various methods. In the fields of rainfall measurement and environmental monitoring such as river height measurement, high measurement reliability, small and inexpensive sensors are required for a service combined with a sensor network. In addition, there is an increasing need for a simple and easy-to-install sensor tag.

Recently, household appliances using water have been trying to reduce power consumption and water consumption by regulating water consumption as well as improving power consumption. For this purpose, a more accurate control of the water level is required. For example, in the washing machine, the water level is measured by a mechanical pressure sensor up to now, but a water level sensor capable of accurate water level measurement is required in order to reduce water consumption.

Conventionally, the water level sensor has been commercialized in various forms. The water level sensor uses a capacitance type water level sensor for measuring the liquid level using the difference in permittivity of air and liquid, an ultrasonic level sensor using an ultrasonic wave generator and a sensor, And a water level sensor for measuring a pressure change according to the pressure.

Among them, the capacitance type water level sensor has been spotlighted in terms of precision and economy, and its measurement principle is as shown in Fig. That is, the capacitance type water level sensor 10 is constituted by a double cylindrical shape of the internal electrode 11 and the external electrode 12 (see Fig. 1 (a)), and the capacitance between the internal electrode 11 and the external electrode 12 (C _h ) between the electrodes according to the height (h) of the liquid (1) of the liquid (1). At this time, the change of the capacitance C _h can be expressed by the following equation (1), which is the capacitance C: the relative permittivity? _R , about 1 of air between the electrodes and the relative permittivity? _r , and about 80 in the case of water.

[ Formula 1 ]

(C: capacitance,? ₀ : vacuum permittivity,? _R : relative dielectric constant, L: cylinder height, a: internal electrode radius, b: external electrode radius)

When a plate type electrostatic capacity level sensor (see Fig. 1 (b)) such as a film is used, the electrostatic capacity can be calculated by the following equation (2).

[ Formula 2 ]

(C: capacitance,? ₀ : vacuum permittivity,? _R : relative dielectric constant, S: electrode area,

Such a capacitance type water level sensor is problematic when it is used in a device in which a liquid container such as a washing machine, a dishwasher, etc., may be made of a metallic material. That is, in the case of a device provided with a container capable of containing liquid, there is a risk of electric shock when the user operates it, so that the capacitance measurement object is generally grounded in many cases. However, in this case, since the liquid contained in the container is regarded as a ground instead of a dielectric, the capacitance type water level sensor using the difference in relative dielectric constant of air and liquid can not measure the capacitance itself.

Therefore, there is a demand for a new water level sensing system that can be applied even when the electrostatic capacitance level sensor is grounded.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a water level sensing system for a device in which the capacitance type water level sensor can be applied even when the object to be measured is grounded.

The present invention also provides a water level sensing system for a device that can increase the measurement reliability.

In addition, the present invention provides a water level sensing system for a device that is easy to install and economical.

According to an aspect of the present invention,

(1) A liquid level sensing system for a device having a container capable of containing a liquid, wherein the liquid in the container or the container is grounded and has a single electrode sensor portion inside or outside the container, And sensing the water level according to the capacitance between the liquid inside the container and the single electrode sensor unit.

(2) In the above (1), the single electrode sensor unit may include: a capacitance sensor having a single electrode of a predetermined length; And a signal processing unit disposed at an upper end of the capacitance sensor and detecting a water level through a sensing signal generated by the capacitance sensor to generate a detection signal.

(3) In the above (2), the water level sensing system may include an antenna for transmitting a detection signal of the signal processing unit to the outside, or supplying power to the signal processing unit and the capacitance sensor; And a solar battery or a battery for power supply. The present invention provides a water level sensing system for a device.

(4) In the above (2), the level sensing system may include: a connection line for transmitting a detection signal of the signal processing unit to the outside; And a connection line for power supply, wherein the system is a streamlined system.

(5) In the above-mentioned (1), the single electrode sensor part is formed between the first insulating film and the second insulating film, and an adhesive film is formed on the back surface of the first insulating film, The present invention provides a water level sensing system for a device.

(6) In the above (5), a shield electrode is further formed between the single electrode sensor part and the first insulating film.

(7) In the above (1), the apparatus may further include a water level measuring hose connected to the container and capable of maintaining the water level equal to the water level in the container, wherein the water level measuring hose includes an inner hose and an outer hose And the single electrode sensor unit is formed in the middle of the inner hose and the outer hose.

(8) In the above (7), a shield electrode is further formed between the single electrode sensor unit and the inner hose.

According to the present invention, the grounded container or the liquid inside the container is used as one electrode, the single electrode sensor portion is used as another electrode, and the grounded container or the liquid inside the container and the single electrode It is possible to provide a water level sensing system for a device capable of sensing the water level by measuring the capacitance between the sensor units.

Further, it is possible to provide a water level sensing system having a sensor having a relatively high sensitivity and a shield electrode and having excellent measurement reliability, a low material cost, an economical use of a film or an adhesive film such as plastic, It is possible to provide a water level sensing system that can be easily mounted.

1 is an explanatory view showing a measurement principle of a capacitance type water level sensor,
2 is a schematic diagram illustrating a water level sensing system of an apparatus according to an embodiment of the present invention,
3 is a layout diagram for explaining the single electrode sensor unit of FIG. 2,
FIG. 4 is a conceptual view for explaining a capacitance change by the system of FIG. 2,
5 is a cross-sectional view illustrating a single electrode sensor unit according to an embodiment of the present invention.
FIG. 6 is a layout view for explaining a wireless type single electrode sensor unit according to an embodiment of the present invention; FIG.
7 is a layout diagram illustrating a streamlined water level sensing system according to an embodiment of the present invention,
8 is a schematic view for explaining an apparatus equipped with a hose for level measurement according to an embodiment of the present invention,
Fig. 9 is an explanatory view showing a manufacturing process of the hose for water level measurement of Fig. 8; Fig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the drawings, the same or equivalent reference numerals are given to the same or similar reference numerals, and the directions are described with reference to the drawings. Also, throughout the specification, when an element is referred to as "including " an element, it means that it may include other elements, not excluding other elements, unless specifically stated otherwise.

FIG. 2 is a schematic view illustrating a water level sensing system of an apparatus according to an embodiment of the present invention, FIG. 3 is a layout diagram for explaining the single electrode sensor unit of FIG. 2, Fig. 3 is a simplified illustration for explaining the position and arrangement of the single electrode 121, the signal processing unit 130 and the solar cell 160 of the single electrode sensor unit 120, The second insulating film 123 is not shown in the completed structure, and the same applies to FIGS. 6 and 7. FIG.

2 to 4, a water level sensing system 100 of an apparatus according to the present invention is a water level sensing system 100 of an apparatus having a container 110 capable of containing a liquid 1, (110) or the liquid (1) inside the container (110) is grounded (111), and a single electrode sensor unit (120) is provided inside or outside the container (110) (C) between the liquid (1) in the container (110) or the single electrode sensor part (120) inside the container (110).

In the water level sensing system 100 according to the present invention, when the water level sensing in a device using a liquid 1 such as water is performed by a difference in capacitance C, It is possible to detect a change in the capacitance C due to the water level even when the liquid 110 contained in the container 110 or the liquid 110 contained in the container 110 is grounded 111 .

That is, the liquid 110 contained in the container 110 or the liquid 110 contained in the container 110 may be used as one electrode and the other electrode may be used as the single electrode sensor unit 120, The liquid level in the container 110 or the liquid 1 in the container 110 and the capacitance C between the single electrode sensor unit 120 are measured and the change is detected to detect the water level.

At this time, if the container 110 of the device or the liquid 110 in the container 110 is not grounded 111 or if the ground 111 is weakly treated, The change in capacitance C can be sensed by the same principle by adding an electrode connected to the capacitor 111. [

The single electrode sensor unit 120 includes a capacitance sensor 121 having a single electrode having a predetermined length and a sensing signal generator 122 disposed at an upper end of the capacitance sensor 121, And a signal processing unit 130 for detecting a water level through the sensing unit 130 and generating a detection signal. The single electrode 121 may be made of a metallic material such as copper, nickel, or silver, and may be electrically connected to the signal processing unit 130 at one end of the single electrode 121. The signal processing unit 130 detects a water level through a sensing signal generated from the single electrode 121 constituting the capacitance sensor 121 to generate a detection signal.

The arrangement of the signal processor 130 may be linear or circular as shown in FIG. 3, and the shape, size, arrangement structure, etc. of the chips or elements constituting the signal processor 130 And may be configured in various ways such as 'a' or 'b'.

An antenna 140 may be disposed at an upper end of the signal processing unit 130 and a battery 150 may be disposed at a side of the antenna 140. The antenna 140 and the battery 150 The solar cell 160 may be disposed at an upper end portion of the solar cell 160. The antenna 140 supplies power to the signal processing unit 130 and the single electrode 121 such as a general RF tag or transmits a detection signal of the signal processing unit 130 to the outside. The shape of the antenna 140 may have a hollow square shape as shown in FIG. 3, or may be arranged in various shapes such as a rectangle, a circle, and a straight line.

3 is a layout diagram of a solar cell 160. The solar cell 100 according to the present invention may be a wireless type or a wire type solar cell having no solar cell 160, ≪ / RTI >

In the case of the wireless type water level sensing system 100 having the solar cell 160 as described with reference to FIG. 3 and the wireless type water level sensing system 100 having no solar cell 160, A signal processing unit 130, an antenna 140 for communication, and a battery (battery) 150 constituting the capacitance sensor 121, 3 < / RTI >

As another example, the wireless type water level sensing system 100 having no solar cell 160 may be a passive type water level sensing system 100 that does not include a battery 150.

7, the single electrode 121 and the signal processing unit 130 constituting the electrostatic capacitance sensor 121 are connected to each other in the case of the streamline type water level sensing system 100 having no solar cell 160, And may include connection lines 170 for transmitting the signal of the signal processing unit 130 to the outside or supplying power to the signal processing unit 130.

Referring to FIG. 4, the water level sensing system 100 according to the present invention as described above includes a single electrode 121 and a grounded container 110 (see FIG. 1) as the level of the liquid 1 increases ) Or the capacitance (C) between the liquid (1) in the container (110) increases. Therefore, in the case of the capacitance type water level sensor in which the container 110 is not used as an electrode, the liquid 110 in the container 110 or the inside of the container 110 is grounded 111, It is possible to overcome the problem that the liquid (1) is grounded (111) and the capacitance (C) can not be measured.

If the liquid 110 is not present in the container 110, the capacitance C appears to be '0' because only the single electrode 121 exists.

Conversely, when liquid 1 is present, the electrostatic capacitance value C between a single electrode and ground can be calculated by Equation (2). The relative dielectric constant ( _r ) of the liquid (l) is about 80, for example, in the case of water.

Accordingly, as the liquid level of the liquid 1 becomes higher, the electrostatic capacitance value C through the single electrode 121 increases proportionally, and the electrostatic capacitance value C obtained in proportion to the liquid level of the liquid (1) The liquid level of the liquid 1 can be grasped through the signal processing unit 130.

Hereinafter, a case where the single electrode sensor unit 120 is located inside or outside the container 110 will be described.

5 is a cross-sectional view illustrating a single electrode sensor unit according to an embodiment of the present invention. 5 and 2, when the single-electrode sensor unit 120 is positioned inside the container 110, the single-electrode sensor unit 120 may include the first insulating film 122 and the second insulating film 122 An adhesive film 124 may be formed on the back surface of the first insulating film 122 and may be vertically attached to the inner surface of the container 110. [

The first insulating film 122 and the second insulating film 123 may be formed of PET (polyethylene terephthalate) or PI (polyimide) for insulation from the liquid 1 of the single electrode 121.

In addition, the adhesive film 124 may be adhered or fixed to a specific site such as one side of the inside of the container by forming an adhesive material film in the form of a double-sided adhesive.

Meanwhile, a shield electrode 125 may be further formed between the single electrode sensor unit 120 and the first insulation film 122. The shield electrode 125 has a wider surface than the single electrode 121, so that the capacitance C can be more stably measured.

FIG. 8 is a schematic view illustrating an apparatus equipped with a hose for level measurement according to an embodiment of the present invention, and FIG. 9 is an explanatory view showing a manufacturing process of the hose for level measurement of FIG.

8 and 9, in an apparatus water level sensing system 200 according to an exemplary embodiment of the present invention, the apparatus is connected to the vessel 210 and has the same water level as the water level in the vessel 210 And the hose 230 for measuring the water level is formed as a double injection molded product of the inner hose 231 and the outer hose 232 so that the single electrode sensor unit 220, May be formed between the inner hose (231) and the outer hose (232).

Generally, in order to measure the level of liquid such as water or oil, a method of measuring the height of a hose which maintains a water level equal to a water level in a container is connected by connecting the container to a vertical type hose. However, when the measurement object exists in the hose and the measurement object is grounded, even if an electrode capable of measuring the capacitance is provided in the hose, it is impossible to detect a change in capacitance due to the change in the water level.

Therefore, according to the present invention, even when the liquid 1 as the object of measurement of the capacitance C is grounded, the hose 230 is formed as a double injection molded body, and the single electrode sensor unit 220 is formed therebetween The single electrode sensor unit 220 is used as one electrode and the liquid 1 and the container 210 connected to the ground 211 are used as other electrodes to measure the electrostatic capacity C ). ≪ / RTI >

The single electrode sensor unit 220 is formed between the double hull 231 and the external hose 232 for insulation with the liquid 1 which is an object of capacitance C measurement. At this time, the single electrode metal layer 220 constituting the single electrode sensor unit 220 is preferably braided to the mesh structure 220 'in order to increase the withstand voltage characteristic of the hose 230. In addition, a shield electrode (not shown) may be further formed between the single electrode metal layer 220 and the inner hose 231 so as to more stably measure the capacitance C.

Hereinafter, a process for manufacturing a hose for level measurement according to an embodiment of the present invention will be described in detail.

First, the combination of the insulating material is manufactured and cooled through the inner hose mold and the injection through the inner hose 231. After the step S1, the woven metal wire 220 'is attached to the outer surface of the inner hose 231 (S2) After the outer hose 232 is formed (S2) through the outer hose mold and injection (S3), the metal hose 232 is cooled (S4) so that the metal wire 220 ' A hose 230 for measuring the level of the electrode 220 is manufactured.

The above-described water level sensing system according to the present invention makes it possible to measure the electrostatic capacitance level of the liquid to be measured connected to the ground, thereby making it possible to perform more precise measurement, thereby suppressing water consumption in the case of a washing machine, etc., . Further, measurement can be performed regardless of the kind of liquid to be measured. That is, the same measurement value can be obtained even when the dielectric constant of the measurement object changes and the measurement object itself changes, and the capacitance of various liquids can be measured with the same sensor.

The foregoing is a description of specific embodiments of the present invention. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments or constructions. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It should be understood that this is possible. It is therefore to be understood that all such modifications and alterations are intended to fall within the scope of the invention as disclosed in the following claims or their equivalents.

100, 200: water level sensing system 110, 210: container
111, 211: ground 120, 220: single electrode sensor unit
121, 221: a single electrode 122: a first insulating film
123: second insulating film 124: adhesive film
125: shield electrode 130: signal processing unit
140: Antenna 150: Battery (battery)
160: Solar cell 230: Hose
231: inner hose 232: outer hose
l: liquid

Claims (8)

1. A level sensing system for a device having a container capable of containing liquid,
Wherein the liquid in the container or the container is grounded and has a single electrode sensor part inside or outside the container so that the liquid level in the container or the liquid inside the container and the capacitance of the single electrode sensor part Sensing,
Wherein the apparatus comprises a hose for level measurement connected to the vessel and capable of maintaining the same level as the level in the vessel, the hose for level measurement being formed of a double injection of an inner hose and an outer hose, Wherein the sensor unit is formed in the middle of the inner hose and the outer hose. The method according to claim 1,
The single-
A capacitance sensor having a single electrode of constant length; And
A signal processing unit disposed at an upper end of the capacitance sensor for detecting a water level through a sensing signal generated by the capacitance sensor and generating a detection signal;
And a sensor for detecting the level of the device. 3. The method of claim 2,
The level sensing system comprises:
An antenna for transmitting a detection signal of the signal processing unit to the outside or supplying power to the signal processing unit and the capacitance sensor; And
Solar cells or batteries for power supply;
Wherein the system is a wireless type system having a plurality of sensors. 3. The method of claim 2,
The level sensing system comprises:
A connection line for transmitting a detection signal of the signal processing unit to the outside; And
Connection line for power supply;
Wherein the system is a streamlined system having a water level sensing system. The method according to claim 1,
Wherein the single-electrode sensor unit is formed between the first insulating film and the second insulating film, and an adhesive film is formed on the back surface of the first insulating film and is vertically attached to one surface of the inside of the container. Sensing system. 6. The method of claim 5,
And a shield electrode is further formed between the single electrode sensor unit and the first insulating film. delete The method according to claim 1,
And a shield electrode is further formed between the single electrode sensor unit and the inner hose.

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