CN214309016U

CN214309016U - Capacitance type water level detection device

Info

Publication number: CN214309016U
Application number: CN202120232125.2U
Authority: CN
Inventors: 尤雅楠; 曹桂水; 庄玮; 王凯
Original assignee: Beijing Tashan Technology Co ltd
Current assignee: Beijing Tashan Technology Co ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2021-09-28
Anticipated expiration: 2031-01-27

Abstract

The utility model provides a capacitance type water level detection device, which comprises a non-metal shell, at least two capacitance plates, a capacitance digital conversion circuit and a control module, wherein the shell is internally provided with the at least two capacitance plates; it is characterized in that the shell corresponding to the position of the polar plate has a structure that the sinking area changes along with the change of water level; the capacitance digital conversion circuit comprises a capacitance excitation signal circuit; the capacitor plate is connected with a capacitor digital conversion circuit; the capacitance digital conversion circuit is connected with the control module, and the control module outputs a control signal of the water level; the product has the characteristics of simple structure, low cost, high detection precision, high stability, strong anti-interference capability, good reliability and the like.

Description

Capacitance type water level detection device

Technical Field

The utility model relates to a capacitanc water level detection device for the water level detection of water tank, specially adapted steam ager.

Background

With the development of new household appliances, kitchen appliances have more and more new categories. Kitchen appliances such as steam boxes, steam-baking integrated machines and the like are emerging continuously.

In order to improve the working efficiency of the steam box and save energy, the water quantity in a heating state is required to be kept at a lower level when the steam box works, and meanwhile, the heating device cannot be in a dry-burning state, so that the whole service life of an electric appliance is not influenced.

In view of the presence of large quantities of water vapor in water tanks, particularly steam boxes, and the effect of bubbles in boiling water, no particularly suitable water level detection device is currently available on the market to solve this problem.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's not enough, provide one kind and be used for the steam ager among the water tank, especially domestic appliance, can integrate the miniature capacitanc water level monitoring device on the heating plate even, can satisfy the inside operational environment of steam ager, richen and the boiling state down the existence of bubble to the reliability requirement that the product provided including steam.

In order to achieve the above object, the utility model provides a following technical scheme: a capacitance type water level detection device comprises a nonmetal shell, at least two capacitance plates, a capacitance digital conversion circuit and a control module, wherein the shell is internally provided with the capacitance plates; it is characterized in that the shell corresponding to the position of the polar plate has a structure that the sinking area changes along with the change of water level; the capacitance digital conversion circuit comprises a capacitance excitation signal circuit; the capacitor plate is connected with a capacitor digital conversion circuit; the capacitance digital conversion circuit is connected with the control module, and the control module outputs a control signal of the water level.

The utility model discloses a capacitanc water level detection device adopts the change of capacitanc detection water level, can accomplish less size, can integrate even on the heating plate, cooperates electric capacity digital conversion circuit (CDC) simultaneously for this product has stronger interference killing feature and higher reliability.

Preferably, the plurality of detection electrodes are arranged in a step shape parallel to the horizontal plane direction, and the shell is a coating material containing the electrode plates of the capacitor and is made of a non-metal material; the shape of the coating material is also in a step shape, and the distance from the outer surface of the coating material to the surface of the detection electrode needs to be smaller than the distance from the side surface of the coating material to the side surface of the detection electrode.

Preferably, the coating material is made of ceramic, glass, PPS and other high-temperature-resistant, non-toxic, environment-friendly and insulating materials.

Preferably, the surface of the coating material is coated with a hydrophobic coating, such as teflon and the like.

Preferably, the electrode material is selected from conductive materials such as red copper, stainless steel and the like.

Preferably, the detection electrode and the coating material are fixed on a heating plate of the steam box, a hole is formed in the center of the heating plate, and the detection electrode and the coating material are located in the center of the heating plate.

Preferably, the detection electrode polar plate is connected with the circuit board with the microcontroller through a cable with a shielding function, a shielding layer of the shielding cable is connected with the steam box heating plate or the steam box casing, and the shielding heating plate is connected with other circuits, the heating rod and the like to interfere the detection device.

Drawings

Fig. 1 is a schematic block diagram of the circuit of the present invention.

Fig. 2 is a sectional structure view of the water level detecting device of the present invention in a ladder arrangement.

Fig. 3 is a sectional structure view of the water level detecting device of the present invention, in which a plurality of electrodes are horizontally arranged in an inclined plane.

Fig. 4 is a sectional structure view of the water level detecting device of the present invention, in which the electrodes are disposed at an angle to the horizontal plane.

Fig. 5 is a sectional structure view of the water level detecting device with the ring-shaped electrode arrangement according to the present invention.

Fig. 6 is a top view of the water level detecting device of the present invention installed in the heating water tray.

Fig. 7 is a sectional structure view of the water level detecting device of the present invention installed in the heating water tray.

Fig. 8 is a schematic view of the general assembly of the product applied in a steaming and baking integrated box.

Detailed Description

The present invention will be described in detail with reference to the following embodiments and the accompanying drawings, wherein the described embodiments are only intended to facilitate the understanding of the present invention, and do not limit the present invention in any way.

The orientations described in the present application, such as up, down, left, right, and left, are convenient to use and described with reference to the drawings, and do not limit the scope of protection.

As fig. 1, for the circuit schematic block diagram of the utility model, electrode plate 11, electrode plate 12 pass through patch cord 5 and insert electric capacity digital conversion circuit 30, contain excitation signal 32 and CDC circuit 31 among the electric capacity digital conversion circuit, and when electrode plate 11, electrode plate 12 become the falling layer of ladder and arrange, can sink respectively or expose the surface of water when the water level changes, cause the change of capacitance value. The highest water level and the lowest water level can be set by adjusting the falling height d 11, and different capacitance values of the electrode plates 12 are changed through the electrode plates 11 and the control module 4 to output control signals of the water levels.

As shown in fig. 2, the electrode plate 11 and the electrode plate 12 are installed inside the non-conductor 40 in a step-wise arrangement, and the outer surface of the non-conductor 40 is also provided with a hydrophobic coating 41 in a step-wise arrangement. d, reference 7, is the maximum minimum detectable water head. The electrode plate 11 and the electrode plate 12 can be made of conductive materials such as red copper, stainless steel and the like, and are connected to the capacitance digital conversion circuit 30 through the lead 5. The non-conductor 40 can be made of glass or ceramic, and the hydrophobic layer 41 can be made of Teflon coating.

Detecting electrode board 12 and detecting electrode board 11 form mutual capacitance, and simultaneously, detecting electrode board 12 and ground, detecting electrode board 11 and ground form the self-capacitance respectively, through the capacitance value that detects these 2 self-capacitances and 1 mutual capacitance to the relation between the contrastive analysis 3 capacitances, can obtain the relevant information of current water level.

For mutual capacitance formed by the electrode plate 12 and the electrode plate 11, in the process of increasing and changing the water level, a medium between the electrode plate 12 and the electrode plate 11 is detected, and in the first stage, the coating material 40, air and water vapor are adopted; the second stage is coating material 40, water, air and water vapor; the third stage is the coating material 40, water; in the second stage, the content of water is continuously increased, and the content of air and water vapor is continuously reduced. Because the water has surface tension, the influence of the water on the

detection electrodes

12 and 11 is sudden change in the process of converting the first stage into the second stage and converting the second stage into the third stage, so that the influence on the capacitance value is obvious. During the water level decreasing change, the medium between the detection electrode 12 and the detection electrode 11 changes, and the whole change process is opposite to the change process of the water level increasing.

For the self-capacitance formed by the electrode plate 12 to the ground, in the process of increasing and changing the water level, detecting a medium between the electrode plate 12 and the ground, wherein in the first stage, the medium comprises a coating material, air and water vapor; the second stage is that the coating material, water, air, water vapor and then water are continuously and rapidly increased;

in the process of reducing and changing the water level, detecting a medium between the electrode 12 and the ground, wherein in the first stage, the medium is coated with materials, water, air and water vapor, and then the water is continuously reduced; the second stage is coating material, air and water vapor; the change in capacitance caused by the change in the medium is significant.

For the third group of capacitors, in the process of increasing and changing the water level, a medium between the electrode 11 and the ground is detected, and in the first stage, the medium is made of a coating material, air and water vapor; the second stage is that the coating material, water, air, water vapor and water amount are rapidly stopped and reduced;

in the process of reducing and changing the water level, detecting a medium between the electrode 11 and the ground, wherein in the first stage, the medium is coated with materials, water, air and water vapor, and then the water is continuously reduced; the second stage is that the coating material, air, water vapor and then water begin to decrease slowly; the change in capacitance caused by the change in the medium is significant.

Through the obvious capacitance value change, the water level information can be clearly determined by comparing the relative relation of several groups of capacitance values.

The shape of the detection head and the number of the detection electrode plates can be correspondingly changed as shown in fig. 3, 4 and 5, and the detection head is in other forms of electrode arrangement, wherein fig. 3 is a three-electrode horizontal arrangement mode. The

electrode plates

11, 12 and 13 are arranged in a horizontal manner at the lower part of the inclined plane formed by the insulator 40, in the figure, the reference numeral 7 is the fall between the three electrode plates, the fall d formed by the

electrode plates

11 and 12 and the fall d1 formed by the

electrode plates

12 and 13 can be equal or unequal, and the electrode plates can be 3 or more electrode plates which are respectively connected into the capacitance digital conversion circuit through the lead 5. The multi-polar plate has the advantage that the water level change can be accurately detected, so that the product can be applied to more scenes, such as the water level detection of a sewage tank or a drinking kettle of a sweeper. Fig. 4 shows an arrangement in which the detecting electrode plate 11 and the detecting electrode plate 12 are parallel to the inclined plane formed by the insulator 40, the electrode plate 11 and the electrode plate 12 have the same height difference d 7, and are connected to the capacitance-to-digital conversion circuit through the lead 5. In fig. 5, the detecting electrode 11 disposed inside the insulator 40 having the hydrophobic layer 41 on the surface thereof may be circular or square and triangular, and the detecting electrode 12 and the detecting electrode 11 are disposed in a manner of a drop d 7, the detecting electrode 12 is circular or square, and the triangle is disposed around the detecting electrode 11 and connected to the capacitance-to-digital conversion circuit through the conducting wire 5.

The housing 40 may have a step structure as shown in fig. 2, or may have a slope structure as shown in fig. 3 or fig. 4; the

capacitor plates

11 and 12 in the housing 40 should have a height difference, but may also be arranged horizontally, so that the matching between the capacitor plates and the housing can reflect the water level change and the capacitance change caused by the water level change, and therefore, all the housings corresponding to the positions of the plates may have a structure in which the sinking area changes along with the water level change.

Fig. 6 and 7 are schematic diagrams of the water level detection device applied to an electric heating plate in a steaming and baking integrated box, and fig. 8 is a general assembly schematic diagram of the water level detection device applied to the steaming and baking integrated box. In the area indicated by the dotted line in the figure, a water level detecting device 10 is provided, a detecting electrode plate having a height difference is provided for falling

layers

11 and 12, and the detecting device 10 is fixed to the heating plate 100 by screws. The electric heating plate 100 is arranged at the lower part in the steaming and baking integrated box 200, and the detection electrode plate is connected into the capacitance digital conversion circuit through a lead 5. The detection device 10 detects the water level change inside the electric heating plate, and controls a water injection pipe positioned at the upper part of the steaming and baking integrated box to inject water into the electric heating plate through a control circuit when the water level is reduced to a certain degree so as to avoid dry burning.

The utility model discloses a to the design of detection device structure appearance, utilize water to have this characteristic of surface tension for the small change of water level converts the huge change of capacitance value into, thereby more clear judgement water level change.

It should be finally noted that the above embodiments are only intended to illustrate the technical solutions of the present invention, and not to limit the scope of the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present invention can be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A capacitance type water level detection device comprises a capacitance digital conversion circuit, a control module and a nonmetal shell, wherein at least two capacitance polar plates are arranged in the shell; it is characterized in that the shell corresponding to the position of the polar plate has a structure that the sinking area changes along with the change of water level; the capacitance digital conversion circuit comprises a capacitance excitation signal circuit; the capacitor plate is connected with a capacitor digital conversion circuit; the capacitance digital conversion circuit is connected with the control module, and the control module outputs a control signal of the water level.

2. The water level detecting apparatus according to claim 1, wherein the surface of the housing has a hydrophobic coating.

3. The water level detecting apparatus according to claim 1, wherein the housing is stepped corresponding to the position of the pole plate.

4. The water level detecting apparatus according to claim 1, wherein the housing is inclined in accordance with the position of the pole plate.

5. The water level detecting apparatus according to claim 1, wherein the plates are arranged with a height difference therebetween.

6. The water level detecting apparatus according to claim 1, wherein the pole plate is disposed parallel to a horizontal plane.

7. The water level detecting device of claim 1, wherein the plate is disposed to be inclined at an angle to a horizontal plane.

8. The water level detecting device of claim 1, wherein the housing is fixed to a heating plate of a steam box.

9. The water level detecting apparatus according to claim 1, wherein the number of the capacitive electrode pads is three.

10. The apparatus of claim 1, wherein the two capacitor plates are concentrically arranged.