Liquid level sensor

Abstract

The liquid level sensor comprises a detection head, a shell and a fastening nut, the detection head is fixedly arranged at the top of the shell, a plurality of liquid detection openings are formed in the surface of the detection head, a polymer film is installed at the top in the shell, a PCBA board is installed at the bottom in the shell, and a pressure chip is installed at the top of the PCBA board. A pressure cavity is arranged in the shell and between the polymer film and the PCBA board; compared with traditional pressure ceramic and other materials, the pressure chip which is used as a semiconductor material for high-sensitivity application occasions such as a microphone has higher sensitivity and stability, millimeter-level liquid depth measurement can be achieved, and data stability is kept. The product is simple in structure and excellent in performance, can be widely applied to various occasions needing liquid depth measurement, such as swimming pool robots, water tanks, consumer electric appliances, road surface water depth monitoring and swimming pool water depth monitoring, and meets the measurement requirements in different scenes.

Description

Technical Field

[0001] This utility model relates to the field of liquid level sensor technology, specifically to a liquid level sensor. Background Technology

[0002] In the field of liquid level measurement, traditional liquid level sensors typically use materials such as pressure ceramics as sensing elements. However, these traditional materials have certain limitations in terms of sensitivity and stability, making it difficult to meet the requirements of high-precision liquid level measurement. With the development of industrial automation, consumer electronics, and environmental monitoring, higher demands are being placed on the performance of liquid level sensors. They not only need to achieve millimeter-level measurement accuracy but also need to have broad applicability to adapt to liquid depth measurement in different scenarios. Utility Model Content

[0003] The purpose of this invention is to provide a liquid level sensor to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a liquid level sensor, comprising a detection head, a housing, and a fastening nut. The detection head is fixedly mounted on the top of the housing, and the surface of the detection head has multiple liquid detection ports. A polymer film is installed on the top of the housing, and a PCBA board is installed on the bottom of the housing. A pressure chip is installed on the top of the PCBA board. A pressure cavity is provided inside the housing and between the polymer film and the PCBA board. Multiple through holes are provided on the top of the housing, and a fastening thread is provided on the surface of the housing. The housing is threadedly connected to the fastening nut through the fastening thread.

[0005] The process involves installing the sensor in the water at the appropriate location using fastening threads and nuts, bringing the exterior of the polymer membrane into contact with the water / liquid. The pressure exerted on the membrane varies at different depths. The polymer membrane deforms under pressure, transmitting this pressure to an internal pressure chamber. This pressure chamber is a completely sealed cavity isolated from the outside, consisting of a shell, the polymer membrane, and a PCBA board. The interior is filled with silicone oil to exclude any internal gas. After the polymer membrane transmits pressure to the pressure chamber, the increased internal pressure is further transmitted by the silicone oil to a pressure chip. This pressure chip senses the water pressure on the membrane and transmits the pressure parameters to the MCU. The pressure chip parameters are then calibrated against the pressure at different liquid depths, converting the pressure parameters into water / liquid depth parameters, ultimately yielding the sensor's depth data.

[0006] The pressure chip uses semiconductor materials typically found in highly sensitive applications such as microphones. Due to the nature of electronic products, they cannot directly contact liquids like water. Therefore, a pressure chamber is designed into the structure to isolate the internal and external environments and conduct pressure. The sensor uses a polymer film with good ductility and corrosion resistance, and can effectively conduct water pressure at different depths to the internal chamber to maximize the performance of the pressure chip.

[0007] Preferably, the detection head has a hollow structure and is hexagonal in shape.

[0008] Preferably, the pressure chamber is filled with silicone oil to expel internal gas.

[0009] Preferably, the bottom of the housing has a cable through hole, the PCBA board is connected to a cable, one end of the cable passes through the cable through hole and is placed outside the housing, and the cable is connected to an external device for power supply and data transmission.

[0010] Preferably, the PCBA board is equipped with a serial communication interface, which allows users to easily connect the sensor and the motherboard using a compatible connector.

[0011] Compared with the prior art, the beneficial effects of this utility model are:

[0012] This pressure chip, employing semiconductor materials typically used in highly sensitive applications such as microphones, offers higher sensitivity and stability compared to traditional pressure ceramics. It enables millimeter-level liquid depth measurement while maintaining data stability. With its simple structure and superior performance, the product can be widely used in various applications requiring liquid depth measurement, including pool robots, water tanks, consumer electronics, road surface water depth monitoring, and swimming pool water depth monitoring, meeting diverse measurement needs. The pressure chamber design, utilizing a polymer film and silicone oil to isolate the internal and external environments, prevents the pressure chip from direct contact with the liquid. This not only protects the pressure chip but also improves the sensor's corrosion resistance and lifespan. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model;

[0014] Figure 2 This is a bottom view of the present invention;

[0015] Figure 3 This is a cross-sectional view of the present invention;

[0016] Figure 4 This is the circuit schematic diagram of this utility model.

[0017] In the diagram: 1. Detection head; 2. Liquid detection port; 3. Outer shell; 4. Fastening thread; 5. Fastening nut; 6. Polymer film; 7. Pressure chip; 8. Cable; 9. PCBA board; 10. Through hole; 11. Cable perforation; 12. Pressure chamber. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0019] Please see Figure 1-4 This utility model provides a liquid level sensor, including a detection head 1, a housing 3, and a fastening nut 5. The detection head 1 is fixedly mounted on the top of the housing 3. The surface of the detection head 1 has multiple liquid detection ports 2. A polymer film 6 is installed on the top of the housing 3. A PCBA board 9 is installed on the bottom of the housing 3. A pressure chip 7 is installed on the top of the PCBA board 9. A pressure cavity 12 is provided inside the housing 3 and between the polymer film 6 and the PCBA board 9. Multiple through holes 10 are opened on the top of the housing 3. The surface of the housing 3 is provided with fastening threads 4. The housing 3 is threadedly connected to the fastening nut 5 through the fastening threads 4.

[0020] The detection head 1 has a hollow structure and a hexagonal shape, which facilitates the uniform application of liquid to the polymer film 6 through the liquid detection port 2. At the same time, the hexagonal shape has good structural stability.

[0021] The pressure chamber 12 is filled with silicone oil. The silicone oil effectively conducts pressure, eliminates the interference of gas inside the pressure chamber 12 on the measurement, and ensures the stability and accuracy of pressure transmission.

[0022] The bottom of the housing 3 has a cable through hole 11. The PCBA board 9 is connected to a cable 8. One end of the cable 8 passes through the cable through hole 11 and is placed outside the housing 3. The cable through hole 11 facilitates the lead-out of the cable 8 and realizes the electrical connection between the sensor and external devices.

[0023] The PCBA board 9 is equipped with a serial communication interface, which facilitates data transmission and communication between the sensor and external control equipment, improving the sensor's compatibility and practicality.

[0024] Working Principle: After the sensor is installed at the corresponding position in the liquid to be measured via the fastening nut 5, the liquid acts on the polymer film 6 through the liquid detection port 2 on the surface of the detection head 1. Liquids at different depths exert different pressures on the polymer film 6, causing it to deform and transmit the pressure to the pressure chamber 12. Since the pressure chamber 12 is filled with silicone oil and is completely sealed, the pressure is transmitted to the pressure chip 7 through the silicone oil. The pressure chip 7 converts the sensed pressure parameters into electrical signals and transmits them to the MCU on the PCBA board. By pre-calibrating the parameters of the pressure chip 7 with the pressure at different liquid depths, the MCU converts the pressure parameters into liquid depth parameters and finally outputs the sensor's depth data through the cable 8 and serial communication interface.

[0025] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A liquid level sensor comprising a detection head (1), a housing (3) and a fastening nut (5), characterized in that The top of the outer shell (3) is fixedly provided with a detection head (1), and the surface of the detection head (1) is provided with multiple liquid detection ports (2). A polymer film (6) is installed on the top of the outer shell (3), and a PCBA board (9) is installed on the bottom of the outer shell (3). A pressure chip (7) is installed on the top of the PCBA board (9). A pressure cavity (12) is provided inside the outer shell (3) and between the polymer film (6) and the PCBA board (9). Multiple through holes (10) are provided on the top of the outer shell (3). A fastening thread (4) is provided on the surface of the outer shell (3). The outer shell (3) is threadedly connected to a fastening nut (5) through the fastening thread (4).

2. A liquid level sensor according to claim 1, characterised in that: The detection head (1) has a hollow structure and is hexagonal in shape.

3. A liquid level sensor according to claim 1, wherein: The pressure chamber (12) is filled with silicone oil.

4. A liquid level sensor according to claim 1, wherein: The bottom of the outer casing (3) is provided with a cable through hole (11), and the PCBA board (9) is connected to a cable (8). One end of the cable (8) passes through the cable through hole (11) and is placed outside the outer casing (3).

5. The liquid level sensor of claim 1, wherein: The PCBA board (9) is equipped with a serial communication interface.

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