Pneumatic liquid level gauge, liquid storage device and plant protection apparatus

Abstract

A pneumatic liquid level gauge, a liquid storage device, and a plant protection apparatus. The pneumatic liquid level gauge comprises: a housing (1), which is internally provided with a component mounting cavity (16), an independent first sensing air chamber (161) being provided in the component mounting cavity (16), and the housing being further provided with a first vent hole (18) in communication with the first sensing air chamber (161); an air pressure sensor (3) mounted in the component mounting cavity (16), the air pressure sensor (3) being capable of sensing the internal air pressure of the first sensing air chamber (161); and a first waterproof pipe (6), one end thereof being connected to the first vent hole (18), the other end thereof being in communication with the atmospheric pressure, and the first sensing air chamber (161) being in communication with the atmosphere by means of the first waterproof pipe (6).

Description

Air pressure liquid level meter, liquid storage device and plant protection equipment

[0001] Cross-reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 2024113783395, filed on September 30, 2024, entitled "An air pressure liquid level meter, liquid storage device and plant protection equipment", and priority to the Chinese patent application No. 2024224137965, filed on September 30, 2024, entitled "An air pressure liquid level meter, liquid storage device and plant protection equipment", the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of inductive devices, and in particular to an air pressure liquid level meter, liquid storage device and plant protection equipment. BACKGROUND

[0004] In the field of plant protection, an air pressure liquid level meter is usually integrated in an automatic pesticide spraying device. The main body of the air pressure liquid level meter is generally installed on the top of the pesticide liquid tank, and the air pipe thereof extends to the bottom of the pesticide liquid tank. The air pressure liquid level meter can be used to automatically monitor the liquid level in the pesticide liquid tank in real time. In order to ensure the detection accuracy, the air pressure sensor in the air pressure liquid level meter installed on the pesticide liquid tank is generally a relative air pressure sensor. The relative air pressure sensor has at least two air pressure detection points. One of the detection points is used to detect the air pressure in the air pipe, and the other detection point is used to detect the atmospheric pressure. By obtaining the difference between the internal and external air pressures and then converting it into a liquid level height, the problem of affecting the liquid level detection accuracy caused by the change of atmospheric pressure can be avoided. Since the air pressure sensor needs to be in communication with the atmosphere to detect the atmospheric pressure, it cannot be installed in an absolutely sealed environment. Therefore, an air hole is usually provided on the shell of the liquid level meter to maintain communication with the atmosphere. However, since the working environment of the equipment in the field of agricultural plant protection is generally an outdoor environment, rainwater, river water and cleaning water, etc. that are usually encountered can easily enter the liquid level meter through the air hole, thereby causing the internal air pressure sensor and circuit board of the existing liquid level meter to be easily damaged by water. At the same time, the short service life and resource inefficiency problems caused by the waterproof defects of the existing liquid level meter also significantly contradict the core requirements of relevant national (such as Brazil) green technology regulations (such as low-carbon agriculture, waste reduction, and material sustainability). Therefore, it is urgent to improve it to meet the local environmental protection standards. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide an air pressure liquid level meter, liquid storage device and plant protection equipment, which can solve the above-mentioned problems existing in the prior art.

[0006] To achieve the above-mentioned purpose, the following technical solutions are adopted in the present application:

[0007] In a first aspect, the application provides a gas pressure liquid level gauge, comprising: a shell, which is internally provided with a device mounting cavity, and the device mounting cavity is internally provided with a separate first sensing air chamber, and the shell is further provided with a first air-permeable hole communicating with the first sensing air chamber; a gas pressure sensor, which is mounted in the device mounting cavity, and the gas pressure sensor can sense the internal air pressure of the first sensing air chamber; and a first waterproof pipe, one end of which is connected to the first air-permeable hole, and the other end of which is in communication with the atmospheric pressure, and the first sensing air chamber is communicated with the atmosphere through the first waterproof pipe.

[0008] In a second aspect, the application provides a liquid storage device, comprising a liquid storage tank and the gas pressure liquid level gauge of any one of the first aspect, the shell of the gas pressure liquid level gauge is mounted on the top of the liquid storage tank, and the gas guide pipe of the gas pressure liquid level gauge extends to the bottom of the liquid storage tank away from the shell.

[0009] In a second aspect, the application provides a plant protection device, comprising a carrier, a spraying system and the liquid storage device of any one of the second aspect, the spraying system and the liquid storage device are mounted on the carrier, and the spraying system is used for pumping and atomizing the liquid medicine in the liquid storage device.

[0010] The application has the following beneficial effects: the application provides a gas pressure liquid level gauge, a liquid storage device and a plant protection device, a separate first sensing air chamber is arranged in the device mounting cavity of the gas pressure liquid level gauge, and a gas pressure sensor is arranged, which can sense the internal air pressure of the first sensing air chamber; the shell of the gas pressure liquid level gauge is provided with a first waterproof pipe communicating with the internal first sensing air chamber, and the first sensing air chamber is communicated with the atmosphere through the first waterproof pipe, thereby realizing the function of the gas pressure sensor sensing the atmospheric pressure. Since the flow area of the first waterproof pipe is small, it is similar to a capillary tube, and when the external liquid enters the first waterproof pipe, the liquid is easy to form a water column in the first waterproof pipe under the action of liquid tension, the water column can isolate the first sensing air chamber from the outside, which is equivalent to forming a blockage to prevent the air in the first sensing air chamber from being discharged, and when the pressure of the external liquid balances with the air pressure in the first sensing air chamber, the liquid cannot continue to enter, thereby achieving the purpose of waterproofing in the first sensing air chamber. Therefore, the gas pressure liquid level gauge of the present application can meet the function of the gas pressure sensor communicating with the atmospheric pressure and detecting the atmospheric pressure in real time under normal use, and can effectively isolate the outside when encountering water, thereby realizing effective waterproofing, i.e. achieving the purpose of providing effective protection for the gas pressure sensor. In addition, since the first sensing air chamber is provided for communicating with the atmospheric pressure, the device mounting cavity does not need to provide air permeability, i.e. the device mounting cavity can be completely sealed, thereby completely avoiding the problem of water entering the main control circuit board and other circuit devices in the device mounting cavity.

[0011] Importantly, the first sensing air chamber is a part separated from the device mounting cavity, so its volume is obviously smaller than the whole device mounting cavity. When the first waterproof pipe is filled with water, the water column in the first waterproof pipe can only compress the air in the first sensing air chamber, which is easier to compress the gas in the smaller first sensing air chamber to have enough pressure compared with compressing the whole device mounting cavity. Therefore, based on this improvement, a better deep water resistance can be obtained even if a shorter first waterproof pipe is arranged.

[0012] In addition, the gas pressure liquid level meter, liquid storage device and plant protection equipment provided by the application solve the problem of water damage to the traditional liquid level meter, and significantly improve the environmental protection and sustainability of the equipment, which is highly consistent with the core requirements of relevant national (such as Brazil) green technology regulations and low-carbon agriculture (ABC+ plan), and embodies the following aspects:

[0013] 1. The first waterproof pipe realizes the waterproof function without relying on consumables (such as filter membranes) or chemical coatings, reducing the frequency of maintenance and replacement and the generation of electronic waste (WEEE), and meeting the requirements of relevant national (such as Brazil) solid waste policies on equipment maintainability.

[0014] 2. The design of the first sensing air chamber makes the gas compression response faster, reduces the risk of circuit board damage caused by waterproof failure, prolongs the service life of the equipment, indirectly reduces resource consumption, and meets the durability standards in relevant national (such as Brazil) INMETRO energy efficiency certification (Procel).

[0015] 3. The liquid level is detected by the gas pressure sensor to ensure the accuracy of liquid level measurement, optimize the pesticide spraying amount, avoid soil and water pollution caused by excessive pesticide application, and directly support the "precision agriculture" and "chemical reduction" goals in relevant national plans (such as Brazil ABC+ plan).

[0016] 4. The completely sealed device mounting cavity design eliminates the risk of liquid seepage into the circuit, prevents harmful waste from being generated after the pesticide contacts with the electronic components, and meets the strict restrictions on toxic substance leakage in relevant national (such as Brazil) environmental crime law.

[0017] 5. The adaptability of the first waterproof pipe to high humidity environment (such as Amazon region rainy season or irrigation operation) reduces the energy waste caused by water damage of the equipment, indirectly reduces the overall carbon footprint of the plant protection equipment, and echoes the relevant national (such as Brazil) climate change policy.

[0018] 6. The modular air chamber and main cavity separation design facilitates the individual replacement of faulty components, reduces the overall scrap rate, and meets the recycling requirements of relevant national (such as Brazil) "reverse logistics law" for electronic products.

[0019] 7. In the above technical solution, the materials of the outer shell and the waterproof pipe can be seamlessly replaced with bio-based plastics or recycled polymers (such as PE derived from sugarcane ethanol), which can meet the requirements of relevant national certifications (such as Brazil's Selo Verde certification) for sustainable materials without structural adjustments.

[0020] In summary, the technical solution proposed in this application, through its innovative physical waterproofing design, simultaneously improves equipment reliability and optimizes environmental benefits without requiring additional energy consumption or chemical treatment. It provides agricultural sectors in relevant countries (such as Brazil) with a plant protection solution that meets green technology certifications (such as Selo Verde) and is both economical and ecological. Attached Figure Description

[0021] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0022] Figure 1 is a schematic diagram of the structure of a pneumatic level gauge provided in an embodiment of this application;

[0023] Figure 2 is a vertical sectional view of the pneumatic level gauge shown in Figure 1;

[0024] Figure 3 is a schematic diagram of the explosion of the pneumatic level gauge shown in Figure 1 with the gas delivery tube concealed.

[0025] Figure 4 is a vertical sectional view of the pneumatic level gauge shown in Figure 1 with the air delivery pipe concealed.

[0026] Figure 5 is an enlarged view of region A in Figure 4;

[0027] Figure 6 is an enlarged view of region B in Figure 4;

[0028] Figure 7 is a structural schematic diagram of the shell base from the top side view of another embodiment of this application;

[0029] Figure 8 is a structural schematic diagram of the shell base from the bottom side view of another embodiment of this application;

[0030] Figure 9 is a structural schematic diagram of the shell base and the first waterproof pipe connected in another embodiment of this application;

[0031] Figure 10 is a schematic diagram of the structure of the shell cover provided in another embodiment of this application;

[0032] Figure 11 is a structural schematic diagram of a pneumatic level gauge provided in another embodiment of this application;

[0033] Figure 12 is a vertical sectional view of the pneumatic level gauge shown in Figure 11;

[0034] Figure 13 is a vertical sectional view of the housing of a pneumatic level gauge provided in another embodiment of this application.

[0035] In the figure: 1, the shell; 11, the shell base; 111, the support boss; 112, the airtight groove; 113, the airtight ring; 1131, the convex rib; 114, the clamping pipe; 1141, the arc-shaped clamping pipe plate; 1142, the clamping block; 12, the shell upper cover; 13, the side wall; 131, the first wall plate; 132, the second wall plate; 1321, the first wall part; 1322, the second wall part; 1323, the step part; 1324, the annular groove; 1325, the waterproof ring; 14, the top cover plate; 15, the inner partition plate; 151, the annular flange; 16, the device mounting cavity; 161, the first sensing air chamber; 1611, the sensor mounting area; 1612, the bypass narrow air passage; 17, the air permeation chamber; 18, the first air permeation hole; 19, the second air permeation hole; 2, the connector; 21, the mounting seat; 211, the second sensing air chamber; 22, the connecting head; 221, the first connecting column; 222, the second connecting column; 223, the air passage; 23, the flexible pipe; 3, the air pressure sensor; 31, the sensor main body; 32, the sensor cannula; 33, the sealing ring; 4, the second waterproof pipe; 5, the air guide pipe; 6, the first waterproof pipe; 7, the main control circuit board. DETAILED DESCRIPTION

[0036] In order to make the technical problems solved in the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present application are described in further detail below. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0037] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] In this application, unless specifically defined otherwise, a first feature "on" or "under" a second feature can include the first and second features being directly in contact with each other, or the first and second features not being directly in contact with each other but being in contact with each other through another feature between them. In addition, the first feature "on", "above" and "over" the second feature includes the first feature being directly above and obliquely above the second feature, or only indicating that the first feature is higher than the second feature in horizontal height. The first feature "under", "below" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or only indicating that the first feature is lower than the second feature in horizontal height.

[0039] In the field of plant protection, a gas pressure liquid level meter is usually integrated in an automatic pesticide spraying device. The main body of the gas pressure liquid level meter is generally installed on the top of the pesticide liquid tank, and a gas pressure sensor 3 is integrated inside, and a gas inlet pipe communicating with the gas pressure sensor 3 is arranged, which extends to the bottom of the pesticide liquid tank. The gas pressure liquid level meter can be used to automatically monitor the liquid level in the pesticide liquid tank in real time. In order to ensure the detection accuracy, the gas pressure sensor 3 in the gas pressure liquid level meter installed on the pesticide liquid tank is generally a relative gas pressure sensor 3. The relative gas pressure sensor 3 has at least two gas pressure detection points, one of which is used to detect the gas pressure in the gas inlet pipe, and the other is used to detect the atmospheric pressure. By obtaining the difference between the internal and external gas pressures and then converting it into the liquid level height, the problem of affecting the liquid level detection accuracy due to the change of atmospheric pressure can be avoided. Since the gas pressure sensor 3 needs to be in communication with the atmosphere to detect the atmospheric pressure, it cannot be installed in an absolutely sealed environment. Therefore, a gas permeable hole is usually provided on the shell 1 of the liquid level meter to maintain communication with the atmosphere. However, since the working environment of the equipment in the field of agricultural plant protection is generally outdoor environment, rainwater, river water and cleaning water etc. contacted in daily life can easily enter the inside of the liquid level meter through the gas permeable hole, thereby causing the problem that the internal gas pressure sensor 3 and circuit board of the existing liquid level meter are easily damaged by water.

[0040] In order to overcome the above technical problems, referring to FIG. 4, the present embodiment provides a gas pressure liquid level meter which can effectively prevent the problem of water damage to internal electronic devices caused by the entry of external splashing water such as rainwater and cleaning water into the inside of the gas pressure liquid level meter. It should be noted that the gas pressure liquid level meter of this embodiment can be combined with the design points of any one or more of the above-mentioned embodiments of the gas pressure liquid level meter.

[0041] The air pressure liquid level gauge comprises a shell 1, an air pressure sensor 3 and a first waterproof pipe 6. The shell 1 is internally provided with a device mounting cavity 16, and the device mounting cavity 16 is internally provided with a first independent air sensing chamber 161. The shell 1 is further provided with a first air permeable hole 18 communicating with the first air sensing chamber 161. The air pressure sensor is mounted in the device mounting cavity 16, and the air pressure sensor can sense the internal air pressure of the first air sensing chamber 161. One end of the first waterproof pipe 6 is connected with the first air permeable hole 18, and the other end is in communication with the atmospheric pressure. The first air sensing chamber 161 is communicated with the atmosphere through the first waterproof pipe 6.

[0042] In some embodiments, the device mounting cavity 16 is used to mount the air pressure sensor 3, the main control circuit board 7 and other devices, and the shell 1 can provide sufficient protection. The first air sensing chamber 161 is a part separated from the device mounting cavity 16, and its volume is necessarily smaller than that of the entire device mounting cavity 16. The air pressure sensor 3 is provided with a first sensitive element for sensing the air pressure in the first air sensing chamber 161. When the air pressure sensor 3 is mounted, it can be mounted in the first air sensing chamber 161 or outside the first air sensing chamber 161, as long as the first sensitive element on the air pressure sensor 3 can be aligned and directed towards the first air sensing chamber 161.

[0043] Under normal conditions, the first waterproof pipe 6 can communicate the first air sensing chamber 161 with the outside world, realizing the communication of the first air sensing chamber 161 with the atmosphere. When encountering water, effective waterproof can be realized through the first waterproof pipe 6. The waterproof principle of the first waterproof pipe 6 is similar to that of a capillary tube. When the external liquid enters the first waterproof pipe 6 through the end of the first waterproof pipe 6 far away from the first air sensing chamber 161, the liquid is easy to form a water column in the first waterproof pipe 6 under the action of liquid tension. The water column can isolate the space between the device mounting cavity 16 and the first waterproof pipe 6 from the outside world, which is equivalent to forming a blockage to prevent the air between the air pressure sensor 3 and the first waterproof pipe 6 from being discharged. When the pressure of the external liquid balances with the air pressure in the first waterproof pipe 6, the liquid cannot continue to enter, so as to achieve the purpose of waterproofing the air pressure sensor 3.

[0044] In summary, the gas pressure liquid level meter based on the embodiment is provided with the independent first sensing air chamber 161 in the device installation cavity 16 of the gas pressure liquid level meter, and is provided with the gas pressure sensor 3 capable of sensing the internal air pressure of the first sensing air chamber 161. The shell 1 of the gas pressure liquid level meter is provided with the first waterproof pipe 6 in communication with the internal first sensing air chamber 161, and the first sensing air chamber 161 is communicated with the atmosphere through the first waterproof pipe 6, thereby realizing the function of the gas pressure sensor 3 sensing the atmospheric pressure. Since the flow area of the first waterproof pipe 6 is small, it is similar to a capillary tube, and when the external liquid enters the first waterproof pipe 6, the liquid is easy to form a water column in the first waterproof pipe 6 under the action of liquid tension, the water column can isolate the first sensing air chamber 161 from the outside, which is equivalent to forming a blockage to prevent the air in the first sensing air chamber 161 from being discharged, and when the pressure of the external liquid balances with the air pressure in the first sensing air chamber 161, the liquid cannot continue to enter, so as to achieve the purpose of waterproofing in the first sensing air chamber 161. Therefore, the gas pressure liquid level meter of the scheme can meet the function of the gas pressure sensor 3 communicating with the atmospheric pressure and detecting the atmospheric pressure in real time under normal use, and can effectively cut off the outside when encountering water, thereby realizing effective waterproofing, that is, achieving the purpose of providing effective protection for the gas pressure sensor 3. In addition, since the first sensing air chamber 161 is provided for communicating with the atmospheric pressure, the device installation cavity 16 does not need to provide air permeability, that is, the device installation cavity 16 can be completely sealed, so that the problem of water entering the main control circuit board 7 and other circuit devices in the device installation cavity 16 can be completely avoided.

[0045] The inventor of the present application has found that when the water bubble accident occurs, the external water enters the first waterproof pipe 6 through the second air permeable hole 19 and forms a water column in the first waterproof pipe 6. The deeper the water bubble, the greater the external water pressure, and the greater the counter air pressure required in the device installation cavity 16, so the water column needs to be compressed to a greater extent. It can be understood that the greater the volume of the device installation cavity 16, the more gas needs to be compressed when the same pressure needs to be increased, that is, the length of the water column needs to be longer. Generally, the control circuit board and other devices are also installed in the device installation cavity 16, which leads to the fact that the space of the device installation cavity 16 cannot be small, therefore, in order to improve the deep water resistance, the length of the first waterproof pipe 6 is one of the ways, however, the space available on the shell 1 for setting the first waterproof pipe 6 is limited, and it is generally difficult to set a first waterproof pipe 6 with a very long length to provide sufficient waterproofing capability.

[0046] In order to overcome the above problems, the first sensing air chamber 161 of the embodiment is a part separated from the device mounting cavity 16, so its volume is obviously smaller than the whole device mounting cavity 16. When the first waterproof pipe 6 is filled with water, the water column in the first waterproof pipe 6 can only compress the air in the first sensing air chamber 161. Compared with compressing the whole device mounting cavity 16, it is easier to compress the gas in the first sensing air chamber 161 with smaller volume to have sufficient pressure. Therefore, based on this improvement, better deep water resistance can be achieved even if the first waterproof pipe 6 is relatively short.

[0047] Based on the design of the first waterproof pipe 6, the air pressure liquid level meter of the embodiment can not only resist normal splashing water, but also provide water immersion resistance. In other words, even if the air pressure liquid level meter is completely immersed in water, the first waterproof pipe 6 can still prevent water from entering the first sensing air chamber 161. The air pressure liquid level meter has obvious advantages in unmanned aerial vehicle-mounted automatic spraying equipment. Even if the whole air pressure liquid level meter is immersed in water, the air pressure liquid level meter of the present solution can still achieve effective waterproof function. When the unmanned aerial vehicle-mounted automatic spraying equipment is working for plant protection, if the unmanned aerial vehicle accidentally falls into the water when flying over the water surface, the unmanned aerial vehicle and the chemical tank will also fall into the water. However, the air pressure liquid level meter can still avoid water entering the inside.

[0048] In addition, when the first waterproof pipe 6 of the air pressure liquid level meter is filled with water and blocked, the water in the first waterproof pipe 6 can be shaken out by shaking or knocking, so that the air pressure liquid level meter can be restored to use.

[0049] When the inventors of the present application initially considered the waterproof design of the gas pressure sensor 3 of the liquid level meter, the most direct idea was to set a waterproof air valve at the air vent of the shell. The waterproof air valve has the function of allowing air to pass through but not water, which can meet the functional requirements of air and water resistance. However, in actual application, the inventors found that when the air-permeable film in the waterproof air valve is stuck with water, the whole waterproof air valve needs to be disassembled, the air-permeable film needs to be dried, and then the waterproof air valve needs to be reassembled. The drainage process is relatively complex. More importantly, since the air-permeable film inside the waterproof air valve cannot be directly observed outside the waterproof air valve, users often cannot judge whether the air-permeable film is stuck with water. Therefore, the waterproof air valve often needs to be disassembled for inspection of the air-permeable film, which causes a certain burden to the user. After many experiments and researches, the inventors of the present application creatively designed the air-permeable waterproof structure with the first waterproof pipe 6 of the embodiment. The first waterproof pipe 6 is made of transparent pipe. Before use, the user can directly observe whether water has entered the first waterproof pipe 6. When water is found, the water in the first waterproof pipe 6 can be drained by shaking or flicking the first waterproof pipe 6. Compared with the waterproof method using the waterproof air valve, the first waterproof pipe 6 of the present solution is more user-friendly.

[0050] In one embodiment, the air pressure sensor is installed in the first sensing air chamber 161, which includes a first sensitive element for sensing the internal air pressure of the first sensing air chamber 161.

[0051] The air pressure sensor is installed in the first sensing air chamber 161, which is more convenient for sealing and isolating the first sensing air chamber 161. Moreover, the air pressure sensor can occupy most of the space in the first sensing air chamber 161, so as to greatly reduce the air volume of the first sensing air chamber 161, which is more conducive to improving the deep water resistance of the present scheme.

[0052] In one embodiment, in combination with FIGS. 3-4, the device mounting cavity 16 is installed with the main control circuit board 7, the housing 1 is provided with an air chamber groove located on one side of the device mounting cavity 16, and the main control circuit board 7 is fixed in the housing 1 and covers the air chamber groove to separate the first sensing air chamber 161.

[0053] The main control circuit board 7 is one of the core components of the air pressure liquid level meter, which is responsible for controlling the operation and data processing of the entire device, and also plays a role in separating space in this design. The main control circuit board 7 is installed in the device mounting cavity 16, and its position is cleverly arranged to cover the air chamber groove. In this way, the main control circuit board 7 naturally becomes a partition, which separates the device mounting cavity 16 into two parts: one part is the main control circuit board 7 and its surrounding area, which is used to install other necessary electronic components; the other part is the covered air chamber groove, i.e. the first sensing air chamber 161. Based on this, the independent first sensing air chamber 161 is separated without adding additional components and complex structures by using the original devices of the air pressure liquid level meter, and the purpose of improving the deep water resistance is achieved. Therefore, the present scheme has the advantages of simple structure and low cost.

[0054] In one embodiment, referring to FIGS. 3-4, the housing 1 includes a shell base 11 and a shell cover 12, the shell cover 12 covers the shell base 11 to form the device mounting cavity 16 between the shell base 11 and the shell cover 12; the air chamber groove is arranged on the shell base 11, and the main control circuit board 7 is fixed on the shell base 11.

[0055] The shell 1 is composed of two parts, a shell base 11 and a shell cover 12. The shell base 11 is used as a support and fixing structure, on which various electronic components and parts can be installed. The shell cover 12 covers the shell base 11 and is tightly combined with the shell base 11 through a sealing connection (such as screws, buckles or glue, etc.), so as to form a relatively closed space, i.e. a device installation cavity 16, between the two. An air chamber groove is arranged on the shell base 11, which realizes the installation of the air pressure sensor 3 on the shell base 11, so that the air pressure sensor 3 can be directly aligned with the connector 2 on the shell base 11, and the functions of detecting atmospheric pressure and liquid side pressure of the air pressure sensor 3 are realized. The main control circuit board 7 is fixedly installed on the shell base 11, and the main control circuit board 7 naturally plays a role of separating the first sensing air chamber 161 from the device installation cavity 16.

[0056] In an embodiment, a gas-tight ring 113 is arranged between the main control circuit board 7 and the shell base 11, and surrounds the air chamber groove.

[0057] By introducing the gas-tight ring 113, the contact surface between the main control circuit board 7 and the shell base 11 is better sealed, thereby improving the air tightness of the first sensing air chamber 161.

[0058] In an embodiment, one side of the gas-tight ring 113 for contacting the main control circuit board 7 is provided with a protruding rib strip 1131 surrounding the air chamber groove, and the protruding rib strip 1131 is arranged in at least two rows and is spaced apart.

[0059] The design of the protruding rib strip 1131 forms a plurality of sealing lines, which can more effectively block the penetration of water and gas, thereby effectively ensuring the air tightness of the first sensing air chamber 161.

[0060] In an embodiment, the shell base 11 is provided with a support boss 111 surrounding the air chamber groove, and the support boss 111 is provided with a gas-tight groove 112, and the gas-tight ring 113 is embedded in the gas-tight groove 112 for installation.

[0061] The combined design of the support boss 111 and the gas-tight groove 112 enables the gas-tight ring 113 to be partially embedded in the gas-tight groove 112 and supported and fixed by the support boss 111, thereby improving the reliability of the installation of the gas-tight ring 113, and in addition, the sealing effect of the gas-tight ring 113 is more significant.

[0062] In an embodiment, a plurality of installation threaded holes surrounding the air chamber groove are arranged on the shell base 11, and the main control circuit board 7 is provided with positioning holes corresponding to the installation threaded holes, and installation screws are screwed into the installation threaded holes through the positioning holes, so as to tightly press the main control circuit board 7 against the gas-tight ring 113.

[0063] During the installation process, the installation screw is used to pass through the positioning hole on the main control circuit board 7 and is screwed into the installation screw hole on the shell base 11. As the screw is tightened, the main control circuit board 7 is gradually pressed against the shell base 11, and at the same time, the air-tight ring 113 is tightly pressed between the two. This pressing method ensures that the air-tight ring 113 forms a reliable sealing interface with the main control circuit board 7 and the shell base 11, effectively preventing the penetration of moisture and gas. At the same time, this structure has the advantage of being able to be repeatedly disassembled and repaired.

[0064] Preferably, a plurality of circuit board locking platforms are arranged on the shell base 11, and installation screw holes are arranged in the circuit board locking platforms. After the main control circuit board 7 is installed on the circuit board locking platform, the screw is fixed, so that the main control circuit board 7 can be reliably installed, and the main control circuit board 7 can be in close contact with the air-tight ring 113.

[0065] In an embodiment, the side of the shell base 11 facing away from the shell upper cover 12 is provided with a connector 2 for connecting the air guide pipe 5, and the first air hole 18 is arranged on the shell base 11 and avoids the connector 2; the air chamber groove includes a sensor installation area 1611 and a bypass narrow air channel 1612, the sensor installation area 1611 is arranged corresponding to the connector 2, and the bypass narrow air channel 1612 communicates the sensor installation area 1611 and the first air hole 18.

[0066] Specifically, the air pressure sensor 3 of the embodiment is a relative air pressure sensor 3, which at least has a first sensing element and a second sensing element. The first sensing element is used to sense the atmospheric pressure, and the second sensing element is used to sense the pressure of the air chamber connected to the liquid. In order to realize the respective functions of the first sensing element and the second sensing element, in the embodiment, the side of the shell base 11 is provided with a connector 2, the connector 2 is connected with a gas guide pipe 5 capable of extending into the liquid, and the connector 2 is provided with a second sensing air chamber 211 in communication with the gas guide pipe 5. After the air pressure sensor 3 is fixedly installed in the device installation cavity 16, the first sensing element is just located at the side of the device installation cavity 16, and the second sensing element is just directed to the second sensing air chamber 211. After the air pressure sensor 3 is installed, the second sensing air chamber 211 and the device installation cavity 16 are just cut off. As long as the device installation cavity 16 is communicated with the atmosphere, the first sensing element can sense the atmospheric pressure, and the second sensing element can sense the air pressure on the liquid side. Preferably, referring to FIG. 5, in order to effectively isolate the second sensing air chamber 211 from the device installation cavity 16, the air pressure sensor 3 comprises a sensor main body 31 and a sensor insertion pipe 32. The first sensing element is located at the side of the sensor main body 31, and the second sensing element is aligned with the lumen of the sensor insertion pipe 32. The position where the second sensing air chamber 211 is connected in the device installation cavity 16 is provided with a sealing ring 33, and the sensor insertion pipe 32 is inserted into the sealing ring 33. Thus, the second sensing air chamber 211 can be effectively isolated from the device installation cavity 16 based on the installation of the air pressure sensor 3 and the sealing ring 33.

[0067] The air chamber groove is divided into two parts, a sensor installation area 1611 and a bypass narrow air channel 1612. The air pressure sensor 3 is installed in the sensor installation area 1611, so that the sensor insertion pipe thereof can be directly aligned with the second sensing air chamber 211 in the connector 2, facilitating the installation of the air pressure sensor 3. In addition, the bypass narrow air channel 1612 is used to communicate the first air-permeable hole 18 with the sensor installation area 1611, so that the sensor installation area 1611 can be communicated with the first waterproof pipe 6, realizing the function of the air pressure sensor 3 sensing the atmospheric pressure. This structure can minimize the volume of the entire first sensing air chamber 161 to the greatest extent on the basis of meeting the air permeability requirement, thereby realizing the purpose of improving the deep water waterproofing capability.

[0068] In another embodiment, the side of the shell base 11 opposite to the shell upper cover 12 is provided with a connector 2 for connecting the gas guide pipe 5, and the air chamber groove is arranged corresponding to the connector 2. The first air-permeable hole 18 is located at the side of the connector 2 and communicates with the air chamber groove.

[0069] In this embodiment, the first air-permeable hole 18 is directly arranged at the side of the connector 2, so that the first air-permeable hole 18 can directly communicate with the air chamber groove inside the connector 2, obtaining the shortest connection path, and the volume of the air chamber groove can be minimized to the greatest extent.

[0070] In an embodiment, the side of the shell base 11 opposite the shell cover 12 is provided with a ventilation chamber 17, and the first waterproof pipe 6 is coiled around the connector 2 in the ventilation chamber 17.

[0071] The ventilation chamber 17 is arranged on the side of the shell base 11 opposite the shell cover 12, and the first waterproof pipe 6 is accommodated in the ventilation chamber 17, which can provide hiding and protection for the first waterproof pipe 6. In addition, when a water immersion accident occurs, external water enters the first waterproof pipe 6 and forms a water column in the first waterproof pipe 6. The deeper the water immersion, the greater the external water pressure, the greater the pressure exerted by the water column on the device mounting cavity 16, the longer the water column formed, and the greater the degree of compression of the gas in the device mounting cavity 16. Therefore, the pressure in the device mounting cavity 16 increases at a greater rate. When the air pressure in the device mounting cavity 16 balances with the external water pressure, the water column cannot continue to extend inward, and therefore the length of the water column that can be formed in the first waterproof pipe 6 determines the waterproof capability of the device mounting cavity 16. The longer the length of the water column that can be formed, the deeper the water in which the device mounting cavity 16 can maintain effective waterproofing, i.e., the better the deep water resistance. The first waterproof pipe 6 is arranged in a coiled shape around the connector 2, which can effectively utilize the limited space in the ventilation chamber 17 to arrange the first waterproof pipe 6. Importantly, the coiled first waterproof pipe 6 has the advantage of a long length while occupying a small amount of space, which is conducive to obtaining a longer first waterproof pipe 6 and achieving better deep water resistance.

[0072] In an embodiment, in combination with FIGS. 8-9, the side of the shell base 11 opposite the shell cover 12 is provided with a pipe clamping member 114, and the first waterproof pipe 6 is clamped in the pipe clamping member 114.

[0073] The design of the pipe clamping member 114 enables the first waterproof pipe 6 to be firmly fixed to the inner partition plate 15, avoiding loosening or falling off due to external factors such as vibration and impact. This stable connection ensures the reliability of the first waterproof pipe 6 during long-term use and prevents water or air leakage caused by unstable connection.

[0074] In an embodiment, the side of the shell base 11 is provided with a second ventilation hole 19, and the ventilation chamber 17 is in communication with the atmosphere through the second ventilation hole 19.

[0075] Specifically, the second ventilation hole 19 is arranged on the side of the shell base 11 to communicate with the atmosphere. It can be understood that after the air pressure liquid level meter of the present embodiment is installed, the device mounting cavity 16 is located above the ventilation chamber 17, i.e., the first ventilation hole 18 is also located above the ventilation chamber 17. When it rains or is washed, even if the splashing water enters the ventilation chamber 17 through the side wall 13 or the hole or groove of the liquid tank that communicates with the ventilation chamber 17, it is difficult for the water to splash upward in the ventilation chamber 17 and enter the device mounting cavity 16 through the first ventilation hole 18.

[0076] Thus, the design structure of the shell itself can resist most of the splashing water to achieve the waterproof purpose, in most cases, water will not enter the first waterproof pipe 6, so as to reduce the number of times of the user to drain the first waterproof pipe 6. The main function of the first waterproof pipe 6 of the embodiment becomes to provide an insurance waterproof function, and in the conventional use process, the external splashing water cannot enter the first waterproof pipe 6. When encountering the water immersion situation, based on the setting of the first waterproof pipe 6, the external water can be prevented from entering the device mounting cavity 16 through the first waterproof pipe 6, so as to provide a normal waterproof function in the water immersion situation. The air pressure liquid level meter with the first waterproof pipe 6 has a great advantage in the automatic spraying equipment carried by the unmanned aerial vehicle, because the air pressure liquid level meter of the present scheme can realize effective waterproof function even if the whole air pressure liquid level meter is immersed in water. When the unmanned aerial vehicle carrying the automatic spraying equipment performs plant protection work, when the unmanned aerial vehicle accidentally falls when flying over the water surface, the unmanned aerial vehicle and the chemical tank fall into the water, and the air pressure liquid level meter can also avoid water entering the inside.

[0077] In an embodiment, the first waterproof pipe 6 utilizes the principle of water surface tension to form a water column in the first waterproof pipe 6 when water enters to prevent external water from further invading the air pressure sensor 3 through the first waterproof pipe 6.

[0078] Specifically, the water surface tension principle is used to realize the waterproof function of the first waterproof pipe 6. Only the inner diameter of the first waterproof pipe 6 needs to be set small enough to form a water column when water enters. The first waterproof pipe 6 of this structure has the advantages of simple structure and low cost.

[0079] In an embodiment, the inner diameter of the first waterproof pipe 6 is 1.5-3.5mm.

[0080] Setting the inner diameter of the first waterproof pipe 6 to 1.5-3.5mm can meet the normal air permeability requirement, and at the same time, the water column formed in the first waterproof pipe 6 by the liquid surface tension can realize the waterproof function.

[0081] In an embodiment, the bottom of the shell 1 is provided with an air permeation chamber 17, the first air permeation hole 18 communicates with the air permeation chamber 17, and the first waterproof pipe 6 is accommodated in the air permeation chamber 17.

[0082] Similarly, the structure of the shell 1 of this embodiment itself has good ability to resist the invasion of splashing water.

[0083] On the other hand, a liquid storage device is provided, which comprises a liquid storage tank and the above-mentioned air pressure liquid level meter, the shell 1 of the air pressure liquid level meter is installed on the top of the liquid storage tank, and the air guide pipe 5 of the air pressure liquid level meter extends to the bottom of the liquid storage tank away from the shell 1.

[0084] Similarly, the air pressure liquid level gauge in the liquid storage device of the embodiment has the advantage of good waterproof capability.

[0085] In another aspect, a plant protection device is provided, which includes a carrier, a spraying system, and the above-described liquid storage device. The spraying system and the liquid storage device are installed on the carrier, and the spraying system is used to pump and atomize the pesticide liquid in the liquid storage device.

[0086] In some embodiments, the carrier can be an unmanned vehicle, a drone, a manually driven vehicle, or the like.

[0087] The spraying system includes a pumping device and an atomizer, and the like. The pipelines at both ends of the pumping device are connected to the liquid storage tank and the atomizer, respectively. The pumping device is used to pump the pesticide liquid in the liquid storage tank out, and the pesticide liquid is uniformly sprayed on crops after being atomized by the atomizer. Based on the carrying of the carrier, mobile spraying operation can be realized.

[0088] Based on the liquid storage device of the embodiment, similarly, the air pressure liquid level gauge in the plant protection device of the embodiment has the advantages of strong waterproof capability and long service life.

[0089] Under normal circumstances, since the air pressure liquid level gauge is located at the top of the pesticide liquid tank, the pesticide liquid in the pesticide liquid tank cannot flow back to contact the air pressure liquid level gauge through the breather pipe. Moreover, in order to meet the normal ventilation requirements, the air pressure sensor 3 cannot be sealed from the breather pipe. Therefore, the existing air pressure sensor 3 is generally exposed to the air connected to the breather pipe. This leads to the problem that when the pesticide liquid tank is accidentally overturned or even inverted, the pesticide liquid is easy to flow back and contact the air pressure sensor 3 through the breather pipe, thereby causing the air pressure sensor 3 to be damaged by water. Therefore, in the existing air pressure liquid level gauge, there is a risk of water entering the side of the air pressure sensor 3 connected to the breather pipe.

[0090] In order to overcome the above technical problems, the embodiment provides an air pressure liquid level gauge, which can meet the requirement of the air pressure sensor 3 sensing the gas pressure on the liquid side, and also can provide reliable waterproof function in emergency to provide reliable protection for the air pressure sensor 3. It should be noted that the air pressure liquid level gauge of the embodiment can be combined with the design points of the air pressure liquid level gauges of any one or more of the above-described embodiments.

[0091] The air pressure liquid level gauge of the embodiment at least includes an air pressure sensor 3, a second waterproof pipe 4, and a gas guide pipe 5. The second waterproof pipe 4 is in communication with the air pressure sensor 3. The inner diameter of the gas guide pipe 5 is greater than that of the second waterproof pipe 4. One end of the gas guide pipe 5 is in communication with the air pressure sensor 3 through the second waterproof pipe 4, and the other end is used to extend into the liquid to sense the water pressure.

[0092] The air pressure liquid level gauge of the embodiment utilizes the air pressure detection principle to realize the function of detecting the liquid level height. In specific application, the air guide pipe 5 extends to the liquid at the end far from the second waterproof pipe 4, the air pressure sensor 3, the second waterproof pipe 4, the air guide pipe 5 and the liquid form a closed cavity, the liquid exerts pressure on the air in the cavity, the air pressure sensor 3 detects the air pressure of the air, the higher the liquid level, the greater the pressure exerted by the liquid on the air in the cavity, and the higher the air pressure value detected by the air pressure sensor 3, that is, the air pressure value detected by the air pressure sensor 3 can be converted into the liquid level height.

[0093] In some embodiments, the waterproof principle of the second waterproof pipe 4 is similar to that of a capillary tube. When the external liquid enters the second waterproof pipe 4 through the end far from the air pressure sensor 3, the liquid is easy to form a water column in the second waterproof pipe 4 under the action of liquid tension, which can isolate the space between the air pressure sensor 3 and the second waterproof pipe 4 from the outside, equivalent to forming a blockage to prevent the air between the air pressure sensor 3 and the second waterproof pipe 4 from being discharged. When the pressure of the external liquid balances with the air pressure in the second waterproof pipe 4, the liquid cannot continue to enter, thereby achieving the purpose of waterproofing the air pressure sensor 3.

[0094] The second waterproof pipe 4 provided in the application does not extend into the liquid at the end connected to the air guide pipe 5 in the normal use state, because the waterproof principle of the second waterproof pipe 4 is to utilize the self-tension of the liquid. When the liquid enters the second waterproof pipe 4, it is easy to form a water column in the second waterproof pipe 4, which is difficult to be removed freely under the action of its own gravity, and the height of the water column is also difficult to change, which leads to that the air pressure in the second waterproof pipe 4 cannot accurately reflect the pressure exerted by the liquid, that is, the air pressure value sensed by the air pressure sensor 3 cannot sensitively reflect the liquid level height, directly leading to the problem of invalidation of the liquid level gauge. Therefore, the air guide pipe 5 plays a crucial role as an intermediate bridge connecting the second waterproof pipe 4 and the liquid. The inner diameter of the air guide pipe 5 is relatively large, and it is also difficult to form a water column in the air guide pipe 5 under the action of the self-tension of the liquid. When the liquid level changes, the liquid level height in the air guide pipe 5 will also sensitively follow the change, so that the air pressure in the air guide pipe 5 can accurately reflect the liquid pressure. The second waterproof pipe 4 is in communication with the air guide pipe 5, so the air pressure in the second waterproof pipe 4 can also accurately reflect the liquid pressure. In summary, on the basis of the second waterproof pipe 4 provided in the embodiment for air permeation and waterproofing of the air pressure sensor 3, the air guide pipe 5 is further provided to extend into the liquid, so that the second waterproof pipe 4 will not be in contact with water in the normal use state, thereby avoiding the problem of affecting the liquid level detection accuracy after the second waterproof pipe 4 is filled with water.

[0095] In specific applications, the air pressure sensor 3 used in the air pressure liquid level gauge can be an absolute air pressure sensor 3 or a relative air pressure sensor 3 according to the use requirements. When the absolute air pressure sensor 3 is adopted, only one sensitive element is arranged thereon, which can sense the air pressure in the second waterproof pipe 4. When the relative air pressure sensor 3 is adopted, two sensitive elements are arranged, one of which can sense the air pressure in the second waterproof pipe 4, and the other can sense the atmospheric pressure. The air pressure difference detected by the two sensitive elements can accurately reflect the actual liquid level height, avoiding the problem of affecting liquid level detection when the atmospheric pressure changes.

[0096] In summary, based on the air pressure liquid level gauge of the embodiment, the second waterproof pipe 4 is arranged to communicate the air guide pipe 5 and the air pressure sensor 3. Under normal circumstances, the air guide pipe 5 and the air pressure sensor 3 can be communicated through the second waterproof pipe 4, so that the air pressure sensor 3 can normally sense the air pressure of the air guide pipe 5, and the function of liquid level detection is realized. The waterproof principle of the second waterproof pipe 4 is similar to that of a capillary tube. When the external liquid enters the air pressure sensor 3 through the end of the second waterproof pipe 4 far away from the air pressure sensor 3, the liquid is easy to form a water column in the second waterproof pipe 4 under the action of liquid tension. The water column can isolate the space between the air pressure sensor 3 and the second waterproof pipe 4 from the outside, which is equivalent to forming a blockage to prevent air between the air pressure sensor 3 and the second waterproof pipe 4 from being discharged. When the pressure of the external liquid balances with the air pressure in the second waterproof pipe 4, the liquid cannot continue to enter, so the purpose of waterproofing the air pressure sensor 3 is achieved.

[0097] The air pressure liquid level gauge of the embodiment can be applied in various scenes requiring liquid level detection, which can be but is not limited to industrial facilities such as reaction kettles and filter tanks; can be but is not limited to household electrical appliances such as washing machines and dishwashers; and can be but is not limited to plant protection equipment such as agricultural liquid tanks and water tanks.

[0098] The air pressure liquid level gauge of the embodiment has more obvious advantages when applied in the scene of agricultural plant protection liquid tanks. The liquid tank needs to be continuously moved in the farmland, so it is generally carried on an unmanned vehicle, an unmanned aerial vehicle, or a manually driven vehicle, or directly carried by a person, that is, the liquid tank is a structure easy to move and transfer. During use, the liquid tank is easy to be tilted, which may cause the liquid to flow and pollute the air pressure sensor 3. Moreover, the liquid itself has a certain corrosive property, which is more likely to cause damage to the air pressure sensor 3. The design of the second waterproof pipe 4 of the present scheme can effectively avoid the problem of water entering the air pressure sensor 3 caused by the tilting of the liquid tank. Therefore, the air pressure liquid level gauge of the present scheme has more obvious advantages when applied in the scene of agricultural plant protection liquid tanks.

[0099] When the inventors of the present application initially considered waterproofing the air pressure sensor 3 of the liquid level meter, the most direct idea was to provide a waterproof air-permeable valve between the air pressure sensor 3 and the air guide pipe 5, which has the function of air permeability and water impermeability, and can exactly meet the demand for air permeability and water resistance. However, in actual application, the inventors found that when the air-permeable membrane in the waterproof air-permeable valve is sticky with water, the entire waterproof air-permeable valve needs to be disassembled, the air-permeable membrane needs to be dried, and then the waterproof air-permeable valve needs to be reassembled, and the drainage process is relatively complex. More importantly, since the air-permeable membrane inside the waterproof air-permeable valve cannot be directly observed outside the waterproof air-permeable valve, the user often cannot judge whether the air-permeable membrane is sticky with water, and often needs to disassemble the waterproof air-permeable valve to check the air-permeable membrane during use, thereby causing a certain burden to the user. After repeated experiments and research, the inventors of the present application creatively designed the air-permeable waterproof structure with the second waterproof pipe 4 of the embodiments of the present application. The second waterproof pipe 4 is made of a transparent pipe, and before use, the user can directly observe whether water has entered the second waterproof pipe 4. When water is found to have entered, the water in the second waterproof pipe 4 can be drained by shaking or flicking the second waterproof pipe 4. Compared with the waterproofing method using the waterproof air-permeable valve, the second waterproof pipe 4 of the present solution is more user-friendly in use.

[0100] In an embodiment, referring to FIGS. 2 and 4, the air pressure sensor 3 further comprises a connector 2, and the connector 2 is internally provided with a second sensing air chamber 211; the air pressure sensor 3 comprises a second sensitive element for sensing the air pressure inside the second sensing air chamber 211, and the second waterproof pipe 4 is connected to the connector 2 and communicates with the second sensing air chamber 211.

[0101] Specifically, the connector 2 can provide mounting support for the air pressure sensor 3, and realize the function of indirect connection between the air pressure sensor 3 and the second waterproof pipe 4. Importantly, the connector 2 can provide a closed second sensing air chamber 211 inside, which is isolated from the outside and communicates with the second waterproof pipe 4 and the air guide pipe 5. The air pressure in the second air pressure sensor 3 can accurately reflect the pressure applied by the liquid, and realize the function of accurately detecting the liquid level. In summary, the provision of the connector 2 provides a reliable bridge for the connection between the air pressure sensor 3 and the second waterproof pipe 4, and effectively guarantees the air tightness of the connection structure.

[0102] In specific implementation, the air pressure sensor 3 can be completely or partially installed into the second sensing air chamber 211; the air pressure sensor 3 can also be installed on the outer surface of the connector 2 (i.e., the air pressure sensor 3 does not extend into the second sensing air chamber 211), as long as the second sensitive element thereon can be aligned towards the second sensing air chamber 211.

[0103] In another embodiment, the air pressure sensor 3 comprises a sensor body 31 and a sensor cannula 32, and the second sensitive element is aligned with a lumen of the sensor cannula 32; the end of the second waterproof tube 4 is directly sleeved to the sensor cannula 32, so that the second sensitive element can accurately sense the air pressure in the second waterproof tube 4.

[0104] With regard to the connection arrangement of the second waterproof tube 4 and the air guide tube 5, in one embodiment, referring to FIG. 2 or FIG. 12, the connector 2 comprises a connecting head 22, which comprises a second connecting column 222 and a first connecting column 221 connected to each other, and the connecting head 22 is provided with an air passage 223 penetrating through the second connecting column 222 and the first connecting column 221, and the air passage 223 communicates with the second sensing air chamber 211; the second waterproof tube 4 is connected to the first connecting column 221, and the air guide tube 5 is sleeved outside the second waterproof tube 4 and connected to the second connecting column 222.

[0105] In this embodiment, the second connecting column 222 and the first connecting column 221 are arranged in the connecting head 22 and are used to connect the air guide tube 5 and the second waterproof tube 4 respectively, so the diameter of the second connecting column 222 needs to be arranged correspondingly to the air guide tube 5, and the diameter of the first connecting column 221 needs to be arranged correspondingly to the second waterproof tube 4. The key of this structure is to realize the sleeving structure of the air guide tube 5 and the second waterproof tube 4, that is, the second waterproof tube 4 is inserted into the air guide tube 5. When the air pressure liquid level meter is inverted, the liquid will first fill the space between the second waterproof tube 4 and the air guide tube 5, and only when the height of the liquid exceeds the height of the free end of the second waterproof tube 4, the liquid can enter the second waterproof tube 4. This is extremely obvious in the application of the plant protection liquid tank. Specifically, the liquid in the used liquid tank cannot be completely emptied, and a small amount of liquid is usually left in the liquid tank. Moreover, the used liquid tank is light in weight and is prone to tilting and inverting. When it is tilted or inverted, a small amount of liquid can easily enter through the free end of the air guide tube 5, and the small amount of liquid will be stored in the space between the second waterproof tube 4 and the air guide tube 5. In this way, the problem of water entering the second waterproof tube 4 can be avoided, and the user does not need to remove the second waterproof tube 4 for drainage in the later use, so as to facilitate the use of the user.

[0106] In one embodiment, the second waterproof tube 4 is sleeved on the first connecting column 221; and / or, the air guide tube 5 is sleeved on the second connecting column 222.

[0107] The sleeving connection structure further enhances the sealing and stability of the connection between the tube and the connector 2.

[0108] Preferably, the second connecting column 222 and the first connecting column 221 are both arranged as a pagoda connecting head 22 to improve the reliability of the connection.

[0109] With reference to the arrangement of the connector 2, in one embodiment, as shown in FIGS. 11-12, the connector 2 comprises a mounting base 21 and a connecting head 22, and the second sensing air chamber 211 is arranged in the mounting base 21, and the mounting base 21 and the connecting head 22 are in an integrated structure.

[0110] The mounting base 21 can be specifically used for mounting the air pressure sensor 3, so that the air pressure sensor 3 is stably mounted. The second sensing air chamber 211 is arranged in the mounting base 21, and after the air pressure sensor 3 is mounted, the second sensing element thereon can be aligned towards the second sensing air chamber 211.

[0111] In implementation, the mounting base 21 can also be arranged to be capable of mounting air pressure devices (such as the main control circuit board 7, etc.). In addition, the mounting base 21 can also be arranged to be capable of being connected with the liquid tank in a cooperative manner, so that the air pressure liquid level meter of the embodiment can be reliably mounted on the liquid tank.

[0112] By designing the mounting base 21 and the connecting head 22 in an integrated structure, the overall structural strength of the connector 2 is significantly improved, and this design can resist greater external force and vibration, and ensure the stability and reliability of the connector 2 under harsh working conditions. The integrated structure design simplifies the manufacturing process of the connector 2, and in the manufacturing process, the machining and assembly of the mounting base 21 and the connecting head 22 can be completed at one time, thereby reducing the production cost and improving the production efficiency. Since there is no additional connection gap between the mounting base 21 and the connecting head 22, the risk of leakage caused by poor connection is reduced, and this design helps to ensure the air tightness inside the connector 2 and ensure the accuracy of air pressure transmission.

[0113] With reference to the arrangement of the connector 2, in another embodiment, as shown in FIGS. 1-2, the connector 2 comprises a mounting base 21, a flexible pipe 23 and a connecting head 22, the second sensing air chamber 211 is arranged in the mounting base 21, and the two ends of the flexible pipe 23 are connected with the mounting base 21 and the connecting head 22 respectively to conduct the second sensing air chamber 211 and the air passage 223.

[0114] The connector 2 adopts an innovative design comprising the mounting base 21, the flexible pipe 23 and the connecting head 22, wherein the flexible pipe 23 as a key component for connecting the mounting base 21 and the connecting head 22 not only realizes the conduction between the second sensing air chamber 211 and the air passage 223, but also endows the connector 2 with unique convenience in maintenance.

[0115] The mounting base 21 can be used to mount the air pressure sensor 3 stably. The second sensing air chamber 211 is arranged on the mounting base 21, and the second sensing element on the air pressure sensor 3 can be aligned to face the second sensing air chamber 211 after the air pressure sensor 3 is mounted. The two ends of the flexible pipe 23 are connected to the mounting base 21 and the connector 22 respectively, ensuring smooth conduction between the second sensing air chamber 211 and the air passage 223, which enables the air pressure to pass through the air guide pipe 5, the connector 22, and the flexible pipe 23 to the second sensing air chamber 211 without obstruction, and be accurately sensed by the air pressure sensor 3. When the second waterproof pipe 4 is filled with water, the conventional connector 2 needs to be disassembled for drainage, while in this embodiment, due to the presence of the flexible pipe 23, the user can directly squeeze the flexible pipe 23 to use the air pressure to squeeze out the water column in the second waterproof pipe 4, thereby quickly restoring the normal use function of the connector 2. This design greatly simplifies the maintenance process and improves the user's operation convenience.

[0116] In an embodiment, the connector 22 is provided with a third connecting column, and the mounting base 21 is provided with a fourth connecting column, and the two ends of the flexible pipe 23 are sleeved on the third connecting column and the fourth connecting column respectively.

[0117] The sleeve connection structure further enhances the sealing and stability of the connection between the flexible pipe 23 and the mounting base 21 and the connector 22 at both ends.

[0118] In an embodiment, the second waterproof pipe 4 uses the surface tension principle of water to form a water column in the second waterproof pipe 4 when water enters to prevent external water from further invading the air pressure sensor 3 through the second waterproof pipe 4.

[0119] Specifically, the waterproof function of the second waterproof pipe 4 is realized by using the liquid surface tension principle, which only needs to set the inner diameter of the second waterproof pipe 4 small enough to form a water column when water enters. This structure of the second waterproof pipe 4 has the advantages of simple structure and low cost.

[0120] In an embodiment, the inner diameter of the second waterproof pipe 4 is 1.5-3.5 mm.

[0121] Setting the inner diameter of the second waterproof pipe 4 to 1.5-3.5 mm can meet the normal air permeability requirement and realize the function of forming a water column in the second waterproof pipe 4 by using the liquid surface tension to achieve waterproof.

[0122] Further preferably, the inner diameter of the second waterproof pipe 4 is 2.5-2.7 mm, which is a small size range that can provide stable air permeability and ensure the stable formation of a water column when water enters.

[0123] In an embodiment, the inner diameter of the air guide pipe 5 is 5-12 mm.

[0124] The inner tube diameter of the air guide pipe 5 is set to 5-12 mm, which can ensure the response speed of the air pressure, so that the air pressure sensor 3 can more timely sense the air pressure change, and improve the accuracy and real-time performance of the measurement.

[0125] In an embodiment, in combination with FIGS. 4-5, the air pressure sensor 3 includes a sensor body 31, one side of the sensor body 31 is provided with a sensor cannula 32; the second sensitive element is arranged in the sensor cannula 32; the connector 2 is provided with a sensing connection hole communicating with the second sensing air chamber 211, and the sensor cannula 32 is inserted into the sensing connection hole, so that the second sensitive element can sense the internal air pressure of the second sensing air chamber 211.

[0126] The specially designed sensing connection hole on the connector 2 is a bridge connecting the second sensing air chamber 211 and the sensor cannula 32, and the sensor cannula 32 is connected to the sensing connection hole in a plug-in manner. This connection method is not only simple and fast, but also can ensure the sealing and reliability of the connection. After plugging, the second sensitive element can directly face the inside of the second sensing air chamber 211 and sense the air pressure change in the second sensing air chamber 211.

[0127] In an embodiment, a sealing ring 33 is arranged in the sensing connection hole, and the sensor cannula 32 is inserted into the sealing ring 33.

[0128] The sealing ring 33 is placed in the sensing connection hole, and when the sensor cannula 32 is inserted, the sealing ring 33 will be tightly compressed between the cannula and the connection hole, forming an effective sealing barrier. This sealing effect effectively guarantees the air tightness of the second sensing air chamber 211, so that the air pressure in the second sensing air chamber 211 can accurately reflect the liquid pressure, thereby ensuring the accuracy of the liquid level detection.

[0129] In an embodiment, the air pressure sensor 3 further includes a first sensitive element for sensing the atmospheric pressure.

[0130] That is, this air pressure sensor 3 is a relative sensor, which can also accurately detect the liquid level when the atmospheric pressure changes.

[0131] In an embodiment, the air pressure liquid level meter includes a shell upper cover 12, which is installed on the connector 2 and covers the air pressure sensor 3.

[0132] Specifically, the main function of the shell upper cover 12 is to protect the air pressure sensor 3 from the external environment. It is installed on the connector 2 and forms a space to isolate the air pressure sensor 3 from dust, moisture, corrosive gases and the like, thereby prolonging the service life of the air pressure sensor 3 and improving its measurement accuracy.

[0133] In addition, the sealed space between the shell upper cover 12 and the connector 2 can also be used to install the main control circuit board 7 and other components required in the air pressure liquid level meter, which also has the function of isolation protection.

[0134] In another aspect, the embodiment also provides a liquid storage device, which comprises a liquid storage tank and the air pressure liquid level meter. The connector 2 of the air pressure liquid level meter is installed on the top of the liquid storage tank, and the air guide pipe 5 of the air pressure liquid level meter extends to the bottom of the liquid storage tank away from the connector 2.

[0135] Similarly, the air pressure liquid level meter in the liquid storage device of the embodiment has the advantage of good waterproof capability.

[0136] In another aspect, a plant protection equipment is provided, which comprises a carrier, a spraying system, and the liquid storage device. The spraying system and the liquid storage device are installed on the carrier, and the spraying system is used to pump out and atomize and spray the pesticide liquid in the liquid storage device.

[0137] The carrier can be an unmanned vehicle, a drone, a manually driven vehicle, etc.

[0138] The spraying system comprises a pumping device and an atomizer, etc. The pipelines at both ends of the pumping device are connected to the liquid storage tank and the atomizer, respectively. The pumping device is used to pump out the pesticide liquid in the liquid storage tank, which is then atomized by the atomizer and uniformly sprayed on crops. Based on the carrying of the carrier, mobile spraying operation can be realized.

[0139] Based on the liquid storage device of the embodiment, similarly, the air pressure liquid level meter in the plant protection equipment of the embodiment has the advantages of strong waterproof capability and long service life.

[0140] In order to ensure the detection accuracy, the air pressure sensor 3 in the air pressure liquid level meter installed on the existing pesticide liquid tank is generally a relative air pressure sensor 3. The relative air pressure sensor 3 has at least two air pressure detection points. One of the detection points is used to detect the air pressure in the air pipe, and the other detection point is used to detect the atmospheric pressure. By obtaining the difference between the internal and external air pressures and then converting it into the liquid level height, the problem of affecting the liquid level detection accuracy due to the change of atmospheric pressure can be avoided. Since the air pressure sensor 3 needs to be in communication with the atmosphere to detect the atmospheric pressure, the air pressure sensor 3 cannot be installed in an absolutely sealed environment. Therefore, a gas permeable hole is usually provided on the shell 1 of the liquid level meter to maintain communication with the atmosphere. However, since the working environment of the equipment in the field of agricultural plant protection is generally an outdoor environment, rainwater, river water, and cleaning water, etc. are easily invaded into the liquid level meter through the gas permeable hole, which further leads to the problem that the existing liquid level meter has the air pressure sensor 3 and the circuit board inside which are easily damaged by water.

[0141] To overcome the above technical problems, with reference to FIG. 4 or FIG. 13, the embodiment also provides another air pressure liquid level meter which can effectively prevent the problem of water damage to the internal electronic devices caused by the entry of external splashing water such as rainwater and cleaning water into the air pressure liquid level meter. It should be noted that the air pressure liquid level meter of this embodiment can be combined with the design points of the air pressure liquid level meter of any one or more of the above embodiments.

[0142] The air pressure liquid level meter of the embodiment includes a shell 1 and an air pressure sensor, the shell 1 includes a side wall 13, a top cover plate 14 and an inner partition plate 15 connected with the side wall 13 respectively, a device mounting cavity 16 is formed between the top cover plate 14 and the inner partition plate 15, and an air permeation chamber 17 is formed on the side of the inner partition plate 15 away from the top cover plate 14; the air permeation chamber 17 is in communication with the atmosphere, and the inner partition plate 15 is provided with a first air permeation hole 18 which communicates the device mounting cavity 16 and the air permeation chamber 17, so that the device mounting cavity 16 can be ventilated with the atmosphere; the air pressure sensor is installed in the device mounting cavity 16, and the air pressure sensor includes a first sensitive element for sensing the air pressure of the device mounting cavity 16.

[0143] Specifically, the side wall 13, the top cover plate 14 and the inner partition plate 15 provided by the shell 1 can exactly form an independent device mounting cavity 16, and the air pressure sensor and the required main control circuit board 7 can be installed in the device mounting cavity 16, which is reliably protected by the shell 1 to realize the functions of waterproofing and dustproofing.

[0144] The first air permeation hole 18 is arranged on the inner partition plate 15, and the air permeation chamber 17 below the inner partition plate 15 is arranged in communication with the atmosphere, so as to realize the purpose of communication between the device mounting cavity 16 and the atmosphere, and enable the air pressure sensor in the device mounting cavity 16 to normally sense the atmospheric pressure.

[0145] The air pressure liquid level meter of the embodiment can be applied in various scenes requiring liquid level detection. For example, the air pressure liquid level meter of the embodiment is applied to a pesticide liquid tank for plant protection. In the specific installation, the shell 1 is fixed on the top of the pesticide liquid tank, that is, the bottom edge of the side wall 13 needs to contact the pesticide liquid tank for installation. At this time, the side wall 13, the inner partition plate 15 and the pesticide liquid tank exactly form the above-mentioned air permeation chamber 17. In order to realize the communication between the air permeation chamber 17 and the atmosphere, a hole position can be arranged on the side wall 13, or a hole position or a groove position which communicates with the air permeation chamber 17 can be arranged on the pesticide liquid tank.

[0146] It can be understood that after the application of the air pressure liquid level meter of the present embodiment is installed, the inner partition plate 15 is located above the air chamber 17, that is, the first air hole 18 provided on the inner partition plate 15 is also located above the air chamber 17. When it rains, is washed, or the like, even if the splashing water enters the air chamber 17 through the side wall 13 or the hole or groove of the liquid tank that communicates with the air chamber 17, it is difficult for the water to splash upward in the air chamber 17 and pass through the first air hole 18 into the device mounting cavity 16.

[0147] In summary, based on the air pressure liquid level meter of the present embodiment, the inner partition plate 15 is provided in the side wall 13 and separated from the top cover plate 14, so that the device mounting cavity 16 is formed between the top cover plate 14 and the inner partition plate 15, the air chamber 17 is formed below the inner partition plate 15, and the first air hole 18 is provided on the inner partition plate 15, so that the device mounting cavity 16 can be ventilated with the atmosphere through the air chamber 17, and the air pressure sensor in the device mounting cavity 16 can sense the atmospheric pressure. When the present scheme is used, when it rains, is washed, or the like, even if a small amount of water splashes into the air chamber 17, the water does not have enough kinetic energy to splash upward and pass through the first air hole 18 into the device mounting cavity 16. Therefore, the present scheme can provide effective protection against splashing water for the devices (such as circuit boards, air pressure sensors 3, etc.) installed in the device mounting cavity 16, and avoid the problem of water damage to the internal devices.

[0148] The air pressure liquid level meter of the present embodiment can be applied in various scenarios that require liquid level detection, such as but not limited to reaction kettles, filter tanks, and other industrial facilities; it can also be but not limited to washing machines, dishwashers, and other household appliances, and it can also be but not limited to agricultural liquid tanks, water tanks, and other plant protection equipment.

[0149] The air pressure liquid level meter of the present embodiment has more obvious advantages when applied in the scenario of an agricultural plant protection liquid tank, because the plant protection liquid tank is used outdoors and it is difficult to avoid rain. In addition, the user often needs to clean the air pressure liquid level meter after use, and the waterproof structure of the present embodiment can meet the needs of the plant protection liquid tank in various splashing water scenarios.

[0150] In one embodiment, in combination with FIGS. 4 and 9, the air chamber 17 is provided with a first waterproof pipe 6, one end of the first waterproof pipe 6 is connected to the first air hole 18, and the other end is a free end, so that the device mounting cavity 16 is ventilated with the air chamber 17 through the first waterproof pipe 6.

[0151] Wherein, under normal conditions, the first waterproof pipe 6 can communicate the device mounting cavity 16 with the air chamber 17, realizing the communication of the device mounting cavity 16 with the atmosphere. When encountering water, the effective waterproof can be realized through the first waterproof pipe 6, and the waterproof principle of the first waterproof pipe 6 is similar to that of the capillary. When the external liquid enters the first waterproof pipe 6 through the end of the first waterproof pipe 6 far away from the device mounting cavity 16, the liquid is easy to form a water column in the first waterproof pipe 6 under the action of liquid tension. The water column can isolate the space between the device mounting cavity 16 and the first waterproof pipe 6 from the outside, which is equivalent to forming a blockage, preventing the air between the air pressure sensor 3 and the first waterproof pipe 6 from being discharged. When the pressure of the external liquid is balanced with the air pressure in the first waterproof pipe 6, the liquid cannot continue to enter, so the purpose of waterproofing the air pressure sensor 3 is achieved.

[0152] It should be noted that the purpose of setting the first waterproof pipe 6 in the embodiment is to provide an insurance waterproof function. In the conventional use process, the external splashing water cannot enter the first waterproof pipe 6. When encountering water immersion, based on the setting of the first waterproof pipe 6, the external water can be prevented from entering the device mounting cavity 16 through the first waterproof pipe 6, realizing the function of providing normal waterproofing in the water immersion condition. The air pressure liquid level meter with the first waterproof pipe 6 has obvious advantages in the automatic spraying equipment carried by the unmanned aerial vehicle. Because the air pressure liquid level meter of the scheme can realize effective waterproofing even if the entire air pressure liquid level meter is immersed in water, when the unmanned aerial vehicle carrying the automatic spraying equipment performs plant protection work, when the unmanned aerial vehicle flies over the water surface and accidentally falls, the unmanned aerial vehicle and the chemical tank fall into the water, and the air pressure liquid level meter can also avoid water entering the inside.

[0153] In addition, when the first waterproof pipe 6 of the air pressure liquid level meter is blocked by water, the water in the first waterproof pipe 6 can be shaken out by swinging or knocking, and the use can be restored.

[0154] When the inventors of the present application initially considered waterproofing the air pressure sensor 3 of the liquid level meter, the most direct idea was to provide a waterproof air permeable valve at the air permeable opening of the housing, which has the function of air permeability and water impermeability, and can exactly meet the functional requirements of air permeability and water resistance. However, in actual application, the inventors found that when the air permeable membrane in the waterproof air permeable valve is sticky with water, the entire waterproof air permeable valve needs to be disassembled, the air permeable membrane needs to be dried, and then the waterproof air permeable valve needs to be reassembled, which is a relatively complex process. More importantly, since the air permeable membrane inside the waterproof air permeable valve cannot be directly observed outside, the user often cannot determine whether the air permeable membrane is sticky with water, and often needs to disassemble the waterproof air permeable valve to check the air permeable membrane during use, thereby causing a certain burden to the user. After repeated experiments and research, the inventors of the present application creatively designed the air permeable and waterproof structure with the first waterproof pipe 6 of the embodiments of the present application. The first waterproof pipe 6 is made of a transparent pipe, and before use, the user can directly observe whether water has entered the first waterproof pipe 6. When water is found, the water in the first waterproof pipe 6 can be discharged by swinging or flicking the first waterproof pipe 6. Compared with the waterproof method using the waterproof air permeable valve, the first waterproof pipe 6 of the present application is more user-friendly in operation.

[0155] In an embodiment, the first waterproof pipe 6 includes a first waterproof pipe 6 main body and an air vent connector connected thereto, and the air vent connector is connected to the first air permeable hole 18 in a plug-in connection manner.

[0156] The first waterproof pipe 6 is divided into a first waterproof pipe 6 main body and an air vent connector, realizing a modular design. This design makes it easier to handle different components during production, installation, and maintenance, improving overall work efficiency and convenience. The air vent connector is connected to the first air permeable hole 18 in a plug-in connection manner. This connection method is not only simple and fast, but also ensures the sealing and stability of the connection. The plug-in connection also facilitates disassembly, maintenance, and replacement when needed, reducing maintenance costs.

[0157] In an embodiment, a flexible pipe 23 is connected between the first waterproof pipe 6 main body and the air vent connector, and the inner diameter of the flexible pipe 23 is greater than the inner diameter of the first waterproof pipe 6 main body.

[0158] The flexible pipe 23 is provided to give the first waterproof pipe 6 unique maintenance convenience. Specifically, when the first waterproof pipe 6 is filled with water, due to the presence of the flexible pipe 23, the user can directly squeeze the flexible pipe 23 to use air pressure to squeeze out the water column in the first waterproof pipe 6, thereby quickly restoring the normal use function of the air pressure liquid level meter. This design greatly simplifies the maintenance process and improves the user's operation convenience.

[0159] In an embodiment, in combination with FIGS. 8 and 9, the side of the inner partition plate 15 away from the top cover plate 14 is provided with a pipe clamping piece 114, and the first waterproof pipe 6 is clamped in the pipe clamping piece 114.

[0160] The design of the card tube 114 enables the first waterproof tube 6 to be firmly fixed on the inner partition plate 15, avoiding loosening or falling off due to external factors such as vibration and impact. This stable connection ensures the reliability of the first waterproof tube 6 during long-term use, preventing water or air leakage caused by unstable connection.

[0161] In an embodiment, the inner partition plate 15 is provided with a connector 2 protruding away from the top cover plate 14 for connecting the air guide tube 5, and the first waterproof tube 6 is wound around the connector 2.

[0162] Specifically, the air pressure sensor 3 of the present embodiment is a relative air pressure sensor 3, which at least has a first sensing element and a second sensing element. The first sensing element is used to sense the atmospheric pressure, and the second sensing element is used to sense the pressure of the gas chamber connected to the liquid. In order to realize the respective functions of the first and second sensing elements, in the present embodiment, one side of the inner partition plate 15 is provided with a connector 2, which is connected with an air guide tube 5 capable of extending into the liquid. The connector 2 is provided with a second sensing gas chamber 211 in communication with the air guide tube 5. After the air pressure sensor 3 is fixedly installed in the device mounting cavity 16, the first sensing element is located on the side of the device mounting cavity 16, and the second sensing element is directed towards the second sensing gas chamber 211. After the air pressure sensor 3 is installed, it just separates the second sensing gas chamber 211 and the device mounting cavity 16. As long as the device mounting cavity 16 is in communication with the atmosphere, the first sensing element can sense the atmospheric pressure, and the second sensing element can sense the air pressure on the liquid side. Preferably, referring to FIG. 5, in order to effectively isolate the second sensing gas chamber 211 from the device mounting cavity 16, the air pressure sensor 3 includes a sensor main body 31 and a sensor insertion tube 32. The first sensing element is located on the side of the sensor main body 31, and the second sensing element is aligned with the lumen of the sensor insertion tube 32. A sealing ring 33 is provided at the position of the second sensing gas chamber 211 in the device mounting cavity 16. The sensor insertion tube 32 is inserted into the sealing ring 33. In this way, the second sensing gas chamber 211 can be effectively isolated from the device mounting cavity 16 based on the installation of the air pressure sensor 3 and the sealing ring 33.

[0163] When the bubble water accident occurs, the external water enters into the first waterproof pipe 6 and forms a water column in the first waterproof pipe 6. The deeper the bubble water, the greater the external water pressure, the greater the pressure applied by the water column to the device mounting cavity 16, the longer the water column formed, and the greater the compression of the gas in the device mounting cavity 16. Therefore, the pressure in the device mounting cavity 16 increases at a greater rate. When the air pressure in the device mounting cavity 16 balances with the external water pressure, the water column cannot continue to extend inwardly. Therefore, the length of the water column that can be formed in the first waterproof pipe 6 determines the waterproof capability of the device mounting cavity 16. The longer the length of the water column that can be formed, the deeper the water in which the device mounting cavity 16 can maintain effective waterproofing, i.e., the better the anti-deep water waterproofing capability. The first waterproof pipe 6 is arranged in a spiral shape around the connector 2 in the present scheme, which can effectively utilize the limited space in the air vent chamber 17 to arrange the first waterproof pipe 6. Importantly, the spiral-shaped first waterproof pipe 6 has the advantage of long length while occupying a small space. This is conducive to obtaining a first waterproof pipe 6 with a longer length and achieving better anti-deep water waterproofing capability.

[0164] In an embodiment, in combination with FIG. 8, the clamping pipe member 114 includes an arc-shaped clamping pipe plate 1141 arranged on the side of the connector 2 away from the first air vent hole 18, and a first clamping pipe groove capable of clamping the first waterproof pipe 6 is formed between the arc-shaped clamping pipe plate 1141 and the connector 2.

[0165] Since the first waterproof pipe 6 is usually cylindrical or tubular in structure, the design of the arc-shaped clamping pipe plate 1141 can better adapt to the shape of the first waterproof pipe 6, and the arc-shaped clamping pipe plate 1141 can be tightly fitted therewith to provide uniform clamping force and reduce the problem of preventing ventilation caused by the bending of the middle part of the first waterproof pipe 6. Moreover, the arc-shaped clamping pipe plate 1141 can utilize the outer wall of the connector 2 to fix the first waterproof pipe 6, thereby achieving the purpose of simplifying the structure of the clamping pipe member 114.

[0166] In an embodiment, the clamping pipe member 114 includes a clamping block 1142 arranged close to the first air vent hole 18, and the clamping block 1142 is provided with a second clamping pipe groove capable of clamping the first waterproof pipe 6.

[0167] Specifically, at the position close to the first air vent hole 18, the first waterproof pipe 6 needs to be avoided, and therefore the clamping block 1142 occupying a smaller space is arranged to provide fixation, i.e., to meet the demand of fixing the first waterproof pipe 6 and to avoid the problem of mutual extrusion caused by the waterproof pipes themselves.

[0168] In an embodiment, the first waterproof pipe 6 utilizes the principle of surface tension of water to form a water column in the first waterproof pipe 6 when water enters to prevent further intrusion of external water through the first waterproof pipe 6 into the air pressure sensor 3.

[0169] Specifically, the liquid surface tension principle is used to realize the waterproof function of the first waterproof pipe 6. Only the inner diameter of the first waterproof pipe 6 needs to be small enough to form a water column when water enters, and the first waterproof pipe 6 of this structure has the advantages of simple structure and low cost.

[0170] In an embodiment, the inner diameter of the first waterproof pipe 6 is 1.5-3.5mm.

[0171] Setting the inner diameter of the first waterproof pipe 6 to 1.5-3.5mm can meet the normal air permeability requirement, and at the same time, the water column formed in the first waterproof pipe 6 by the liquid surface tension can realize the waterproof function.

[0172] Further preferably, the inner diameter of the first waterproof pipe 6 is 2.5-2.7mm, which is a small size range that can provide stable air permeability and ensure the formation of a stable water column when water enters.

[0173] In an embodiment, referring to FIGS. 7-8, the side wall 13 is provided with a second air permeation hole 19 communicating with the air permeation chamber 17, so that the air permeation chamber 17 is in communication with the atmosphere.

[0174] By providing the second air permeation hole 19 in the side wall 13 to realize air permeation, the liquid tank on which the air pressure liquid level gauge is installed does not need to have a corresponding hole or groove, and the air pressure liquid level gauge of this embodiment can be directly applied to the existing liquid tank and used normally without any improvement of the liquid tank.

[0175] Regarding the setting form of the shell 1, in an embodiment, in combination with FIGS. 3, 4 and 6, the shell 1 includes a shell base 11 and a shell cover 12, the shell base 11 includes a first surrounding wall plate 131 and an inner partition plate 15 connected together; the shell cover 12 includes a second surrounding wall plate 132 and a top cover plate 14 connected together, the shell cover 12 is buckled on the shell base 11, the first surrounding wall plate 131 and the second surrounding wall plate 132 are connected to form the side wall 13, and the second air permeation hole 19 is arranged on the first surrounding wall plate 131.

[0176] The shell 1 is divided into two modules, the shell base 11 and the shell cover 12, which can be manufactured and processed separately and then assembled, and this modular design not only improves the production efficiency, but also facilitates subsequent maintenance and replacement. The shell cover 12 is buckled on the shell base 11, and appropriate fixing methods (such as buckles, screws, etc.) are used to ensure the tight connection between the two, and this assembly method is not only simple and fast, but also can ensure the sealing and stability of the shell 1.

[0177] In an embodiment, in combination with FIGS. 6 and 7, the inner partition plate 15 is protrudingly arranged on the side of the first surrounding wall plate 131 relative to the top cover plate 14, the inner cavity of the second surrounding wall plate 132 corresponds to the outer dimensions of the inner partition plate 15, and the inner partition plate 15 is embedded in the second surrounding wall plate 132.

[0178] When the shell top cover 12 is buckled on the shell base 11, the second surrounding wall plate 132 is automatically aligned with and tightly contacted with the first surrounding wall plate 131 due to the embedding of the inner partition plate 15 into the second surrounding wall plate 132, which simplifies the assembly process, reduces the requirement for assembly accuracy, and improves the production efficiency. The inner partition plate 15 is protrudingly arranged relative to the first surrounding wall plate 131 towards the side where the top cover plate 14 is located and is embedded into the second surrounding wall plate 132, so that the inner partition plate 15 can serve as a positioning and fixing point between the shell top cover 12 and the shell base 11 during the assembly process, thereby enhancing the overall structural stability of the shell 1. Through the tight cooperation between the inner partition plate 15 and the second surrounding wall plate 132 and the contact between the inner partition plate 15 and the first surrounding wall plate 131, a continuous sealing barrier is formed between the gas permeation chamber 17 and the device mounting cavity 16 of the shell 1. This sealing barrier effectively prevents the infiltration of liquid medicine or other impurities into the internal components, thereby ensuring the normal operation and long-term stability of the gas pressure liquid level meter.

[0179] In an embodiment, in combination with FIG. 6, the second surrounding wall plate 132 includes a first surrounding wall portion 1321 and a second surrounding wall portion 1322 connected in a stepped structure, a step portion 1323 parallel to the inner partition plate 15 is formed between the first surrounding wall portion 1321 and the second surrounding wall portion 1322, a waterproof ring 1325 abutting against the step portion 1323 is mounted on the inner side of the first surrounding wall portion 1321, and the inner partition plate 15 is embedded into the first surrounding wall portion 1321 and abuts against the waterproof ring 1325.

[0180] The waterproof ring 1325 is mounted on the inner side of the first surrounding wall portion 1321 and tightly abuts against the step portion 1323. The waterproof ring 1325 is usually made of soft and elastic materials such as rubber or silicone to ensure good sealing effect. The inner partition plate 15 is embedded into the first surrounding wall portion 1321 and directly abuts against the waterproof ring 1325. This design not only provides stable support for the inner partition plate 15, but also forms a tight sealing connection between the waterproof ring 1325 and the shell 1, effectively preventing liquid or gas from leaking from the gaps of the shell 1.

[0181] In an embodiment, the step portion 1323 is provided with an annular groove 1324, and the waterproof ring 1325 is embeddedly mounted in the annular groove 1324.

[0182] The step portion 1323 is provided with an annular groove 1324, which is specially designed for the installation of the waterproof ring 1325. The shape and size of the annular groove 1324 are matched with those of the waterproof ring 1325 to ensure that the waterproof ring 1325 can be stably embedded therein. The waterproof ring 1325 is embeddedly mounted in the annular groove 1324, which not only simplifies the assembly process, but also forms a tight fit between the waterproof ring 1325 and the step portion 1323, thereby improving the sealing effect.

[0183] In an embodiment, the peripheral portion of the inner partition plate 15 is provided with an annular flange 151, which is embedded in the annular groove 1324 to abut against the waterproof ring 1325.

[0184] The peripheral portion of the inner partition plate 15 is provided with an annular flange 151, which is embedded in the annular groove 1324 on the stepped portion 1323 and tightly abuts against the waterproof ring 1325. Such an embedded design forms a continuous and tight sealing structure among the inner partition plate 15, the waterproof ring 1325 and the stepped portion 1323, further enhancing the sealing effect of the waterproof ring 1325 and ensuring the dryness and cleanliness of the inside of the shell 1.

[0185] Regarding the arrangement form of the shell 1, in another embodiment, referring to FIG. 13, the side wall 13 and the top cover plate 14 are in an integrated structure, and the inner partition plate 15 is embeddedly installed in the side wall 13.

[0186] This structure can also achieve the structure of forming the device mounting cavity 16 and the air permeation chamber 17 above and below the inner partition plate 15 respectively, achieving the waterproof purpose.

[0187] In an embodiment, the side wall 13 away from the top cover plate 14 is provided with a mounting boss, and the mounting boss is provided with a mounting hole.

[0188] The peripheral portion of the side wall 13 is provided with a mounting boss, and the mounting boss is provided with a mounting hole, which facilitates the installation of the air pressure liquid level meter of the embodiment on the liquid tank. Specifically, during installation, a threaded hole is provided on the liquid tank, and the air pressure liquid level meter can be reliably fixed by locking the bolt passing through the mounting hole to the threaded hole.

[0189] On the other hand, a liquid storage device is provided, which includes a liquid storage tank and the air pressure liquid level meter described above. The shell 1 of the air pressure liquid level meter is installed on the top of the liquid storage tank, and the air guide pipe 5 of the air pressure liquid level meter extends to the bottom of the liquid storage tank away from the shell 1.

[0190] Similarly, the air pressure liquid level meter in the liquid storage device of the embodiment has the advantage of good waterproof capability.

[0191] In another aspect, a plant protection equipment is provided, which includes a carrier, a spraying system and the liquid storage device described above. The spraying system and the liquid storage device are installed on the carrier, and the spraying system is used to pump out and atomize and spray the liquid in the liquid storage device.

[0192] The carrier can be an unmanned vehicle, a drone, a manually driven vehicle, etc.

[0193] The spraying system comprises a pumping device and an atomizer, and pipelines at both ends of the pumping device are connected with a liquid storage tank and the atomizer respectively, the liquid in the liquid storage tank is pumped out by the pumping device, and is uniformly sprayed on crops after being atomized by the atomizer.

[0194] Based on the liquid storage device, the air pressure liquid level gauge in the plant protection equipment has the advantages of strong waterproof ability and long service life.

[0195] In the description herein, it should be understood that the terms "upper", "lower", "left", "right", and the like orientation or position relationship are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0196] In the description of the present specification, the description referring to the terms "an embodiment", "an example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0197] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

[0198] The technical principles of the present application are described above in combination with specific embodiments. These descriptions are only for the purpose of explaining the principles of the present application, and cannot be interpreted in any way as a limitation on the scope of protection of the present application. Based on the explanation here, those skilled in the art do not need to make creative efforts to conceive other specific embodiments of the present application, and these embodiments will fall within the scope of protection of the present application.

Claims

1. A gas pressure liquid level gauge, comprising: a housing, in which a device mounting cavity is arranged, and a first independent sensing gas chamber is arranged in the device mounting cavity, and the housing is further provided with a first air hole communicating with the first sensing gas chamber; a gas pressure sensor, which is mounted in the device mounting cavity, and the gas pressure sensor can sense the internal gas pressure of the first sensing gas chamber; a first waterproof pipe, one end of which is connected with the first air hole, and the other end of which is communicated with the atmospheric pressure, and the first sensing gas chamber is communicated with the atmosphere through the first waterproof pipe.

2. The air pressure liquid level gauge according to claim 1, wherein, The gas pressure sensor is mounted in the first sensing gas chamber, which includes a first sensitive element for sensing the internal gas pressure of the first sensing gas chamber.

3. The air pressure liquid level gauge according to claim 1, wherein, A main control circuit board is mounted in the device mounting cavity, and a gas chamber groove is arranged in one side of the device mounting cavity in the housing, and the main control circuit board is fixed in the housing and covers the gas chamber groove to separate the first sensing gas chamber.

4. The air pressure liquid level gauge according to claim 3, wherein, The housing includes a shell base and a shell cover, and the shell cover covers the shell base to form the device mounting cavity between the shell base and the shell cover; the gas chamber groove is arranged on the shell base, and the main control circuit board is fixed on the shell base.

5. The air pressure liquid level gauge according to claim 4, wherein, A gas-tight ring is arranged between the main control circuit board and the shell base and surrounds the gas chamber groove.

6. The air pressure liquid level gauge according to claim 5, wherein, One side of the gas-tight ring for contacting the main control circuit board is provided with a convex rib strip surrounding the gas chamber groove, and the convex rib strip is at least two and is arranged at intervals.

7. The air pressure liquid level gauge according to claim 5, wherein, The shell base is provided with a supporting boss surrounding the gas chamber groove, and the supporting boss is provided with a gas-tight groove, and the gas-tight ring is embedded in the gas-tight groove for installation.

8. The air pressure liquid level gauge according to claim 5, wherein, A plurality of mounting screw holes surrounding the gas chamber groove are arranged on the shell base, and the main control circuit board is provided with positioning holes corresponding to the mounting screw holes, and mounting screws pass through the positioning holes and are screwed to the mounting screw holes, so that the main control circuit board is tightly pressed against the gas-tight ring.

9. The air pressure liquid level gauge according to claim 4, wherein, A connector for connecting a gas guide pipe is convexly arranged on one side of the shell base away from the shell cover, and the first air hole is arranged on the shell base and avoids the connector; the gas chamber groove includes a sensor mounting area and a bypass narrow air passage, and the sensor mounting area is arranged corresponding to the connector, and the bypass narrow air passage communicates the sensor mounting area and the first air hole.

10. The air pressure liquid level gauge according to claim 4, wherein, A connector for connecting a gas guide pipe is convexly arranged on one side of the shell base away from the shell cover, and the gas chamber groove is arranged corresponding to the connector, and the first air hole is arranged on the side of the connector and communicates with the gas chamber groove.

11. The air pressure liquid level gauge according to claim 10, wherein, A gas permeation chamber is arranged on one side of the shell base away from the shell cover, and the first waterproof pipe spirals in the gas permeation chamber around the connector.

12. The air pressure liquid level gauge according to claim 11, wherein, A clamping pipe element is arranged on one side of the shell base away from the shell cover, and the first waterproof pipe is clamped in the clamping pipe element.

13. The air pressure liquid level gauge of claim 11, wherein, A second air hole is arranged on the side of the shell base, and the gas permeation chamber is communicated with the atmosphere through the second air hole.

14. The air pressure liquid level gauge of claim 1, wherein, The first waterproof pipe utilizes the principle of surface tension of water, and when water enters, a water column is formed in the first waterproof pipe to prevent external water from further invading the gas pressure sensor through the first waterproof pipe.

15. The air pressure liquid level gauge of claim 14, wherein, The inner diameter of the first waterproof pipe is 1.5-3.5 mm.

16. The air pressure liquid level gauge of claim 1, wherein, The bottom of the shell is provided with a gas-permeable chamber, the first gas-permeable hole is communicated with the gas-permeable chamber, and the first waterproof pipe is accommodated in the gas-permeable chamber.

17. The gas pressure liquid level gauge according to any one of claims 1 to 16, wherein The gas pressure liquid level meter is applied to a pesticide liquid tank for plant protection.

18. A liquid storage device comprising a liquid storage tank and the gas pressure liquid level meter according to any one of claims 1 to 17.

19. A plant protection equipment comprising a carrier, a spraying system and the liquid storage device according to claim 18, wherein the spraying system and the liquid storage device are mounted on the carrier, and the spraying system is used for pumping and atomizing spraying the pesticide liquid in the liquid storage device.

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