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

Abstract

A pneumatic level gauge, comprising: an air pressure sensor (3); a first waterproof pipe (4) communicated with the air pressure sensor (3); and an air guide pipe (5), wherein the inner diameter of the air guide pipe (5) is greater than that of the first waterproof pipe (4), and the air guide pipe (5) has one end communicated with the air pressure sensor (3) by means of the first waterproof pipe (4), and the other end used for extending into liquid so as to sense water pressure. Under normal circumstances, the air guide pipe (5) can be communicated with the air pressure sensor (3) by means of the first waterproof pipe (4), so that the air pressure sensor (3) can normally sense the air pressure of the air guide pipe (5), thereby realizing a liquid level measurement function; and the first waterproof pipe (4) can also provide a waterproofing effect on the air pressure sensor (3). Also provided are a liquid storage device and a plant protection device.

Description

A gas pressure liquid level meter, liquid storage device and plant protection equipment

[0001] The present disclosure claims priority to Chinese Patent Application No. 202411378335.7, filed on September 30, 2024, entitled "A gas pressure liquid level meter, liquid storage device and plant protection equipment" and Chinese Patent Application No. 202422413752.2, filed on September 30, 2024, entitled "A gas pressure liquid level meter, liquid storage device and plant protection equipment", both of which are incorporated by reference in their entirety in the present disclosure. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of sustainable agriculture, and in particular, to a gas pressure liquid level meter, liquid storage device and plant protection equipment. BACKGROUND

[0003] 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 a pesticide tank. A gas pressure sensor is integrated inside the main body, and a gas inlet pipe is arranged to communicate with the gas pressure sensor. The gas inlet pipe extends to the bottom of the pesticide tank. The gas pressure liquid level meter can be used to automatically monitor the liquid level in the pesticide tank in real time.

[0004] Under normal circumstances, since the gas pressure liquid level meter is located at the top of the pesticide tank, the pesticide in the pesticide tank cannot flow back to contact the gas pressure sensor through the gas inlet pipe. Moreover, in order to meet the normal ventilation requirements, the gas pressure sensor cannot be sealed from the gas inlet pipe. Therefore, the gas pressure sensor in the related art is generally exposed to the air communicated with the gas inlet pipe. This leads to the problem that when the pesticide tank is accidentally tipped over or even inverted, the pesticide can easily flow back through the gas inlet pipe and contact the gas pressure sensor, thereby causing the gas pressure sensor to be damaged by water. Therefore, in the gas pressure liquid level meter in the related art, there is a risk of water entering the side of the gas pressure sensor connected to the gas inlet pipe.

[0005] If the gas pressure sensor is damaged by water, it will not be able to accurately detect the liquid level in the pesticide tank, thereby causing the agricultural equipment to be unable to accurately control the spraying flow of the pesticide. In some places, the pesticide may be excessively sprayed, causing environmental pollution. Moreover, there may be a problem that the agricultural equipment returns before the pesticide is completely sprayed, resulting in waste of energy and increase of carbon emissions. In addition, the gas pressure sensor itself is an electronic device, which becomes electronic waste after being damaged by water, posing a risk of environmental pollution. SUMMARY

[0006] The purpose of the embodiments of the present disclosure is to provide a gas pressure liquid level meter, liquid storage device and plant protection equipment, which can solve the problem of the risk of water entering the side of the gas pressure sensor connected to the gas inlet pipe in the related art.

[0007] To achieve the above object, the present disclosure adopts the following technical solutions:

[0008] In one aspect, a gas pressure liquid level gauge is provided, comprising:

[0009] a gas pressure sensor;

[0010] a first waterproof pipe in communication with the gas pressure sensor;

[0011] a gas guide pipe having an inner diameter larger than that of the first waterproof pipe, one end of the gas guide pipe being in communication with the gas pressure sensor through the first waterproof pipe, and the other end being used to extend into a liquid to sense water pressure.

[0012] Optionally, a connector is further included, the connector having a first sensing air chamber inside; the gas pressure sensor includes a first sensitive element for sensing the air pressure inside the first sensing air chamber, and the first waterproof pipe is connected to the connector and in communication with the first sensing air chamber.

[0013] Optionally, the connector includes a connector head, the connector head including a first connecting column and a second connecting column connected to each other, the connector head having an air passage passing through the first connecting column and the second connecting column, the air passage being in communication with the first sensing air chamber; the first waterproof pipe is connected to the second connecting column, and the gas guide pipe is sleeved outside the first waterproof pipe and connected to the first connecting column.

[0014] Optionally, the first waterproof pipe is sleeved to the second connecting column; and / or, the gas guide pipe is sleeved to the first connecting column.

[0015] Optionally, the connector includes a mounting seat and the connector head, the first sensing air chamber being arranged in the mounting seat, and the connector head and the mounting seat being an integral structure.

[0016] Optionally, the connector includes a mounting seat, a flexible pipe and the connector head, the first sensing air chamber being arranged in the mounting seat, and two ends of the flexible pipe being connected to the mounting seat and the connector head respectively to lead the first sensing air chamber and the air passage.

[0017] Optionally, the connector head is provided with a third connecting column, the mounting seat is provided with a fourth connecting column, and two ends of the flexible pipe are sleeved to the third connecting column and the fourth connecting column respectively.

[0018] Optionally, the first waterproof pipe utilizes the surface tension principle of water, and when water enters, a water column is formed in the first waterproof pipe to prevent further intrusion of external water into the gas pressure sensor through the first waterproof pipe.

[0019] Optionally, the inner diameter of the first waterproof pipe is 1.5-3.5 mm.

[0020] Optionally, the inner diameter of the air guide tube is 5-12mm.

[0021] Optionally, the air pressure sensor comprises a sensor body, one side of the sensor body is provided with a sensor insertion tube; the first sensitive element is arranged in the sensor insertion tube; the connector is provided with a sensing connection hole communicating with the first sensing air chamber, and the sensor insertion tube is inserted into the sensing connection hole, so that the first sensitive element can sense the internal air pressure of the first sensing air chamber.

[0022] Optionally, a sealing ring is arranged in the sensing connection hole, and the sensor insertion tube is inserted into the sealing ring.

[0023] Optionally, the air pressure sensor further comprises a second sensitive element for sensing atmospheric pressure.

[0024] Optionally, a shell upper cover is arranged, which is mounted on the connector and covers the air pressure sensor.

[0025] Optionally, the air pressure liquid level meter is applied to a pesticide liquid tank for plant protection.

[0026] In another aspect, a liquid storage device is provided, comprising a liquid storage tank and the air pressure liquid level meter.

[0027] In yet another aspect, a plant protection equipment is provided, comprising a carrier, a spraying system and the liquid storage device, the spraying system and the liquid storage device are mounted on the carrier, and the spraying system is used for pumping and atomizing the pesticide liquid in the liquid storage device.

[0028] The air pressure liquid level meter, the liquid storage device and the plant protection equipment provided by the present disclosure have the following beneficial effects: the first waterproof pipe is arranged in the air pressure liquid level meter to communicate the air guide tube and the air pressure sensor, under normal circumstances, the air guide tube and the air pressure sensor can be communicated through the first waterproof pipe, so that the air pressure sensor can normally sense the air pressure of the air guide tube, and the function of liquid level detection is realized; in addition, the first waterproof pipe can also realize waterproof of the air pressure sensor, so as to avoid the air pressure sensor from being damaged by water and becoming electronic waste, thereby causing pollution to the environment. The air pressure sensor is not easy to be damaged by water, so the air pressure liquid level meter can accurately detect the liquid level, thereby ensuring the accuracy of the spraying amount of the pesticide liquid, so as to prevent the problem of environmental pollution caused by excessive spraying of the pesticide liquid. The air pressure sensor accurately detects the liquid level in the pesticide liquid tank, which can also avoid the situation that the pesticide liquid in the pesticide liquid tank is not sprayed completely before returning to supplement the liquid, reduce the invalid movement of the plant protection equipment, avoid the waste of energy, and reduce carbon emissions. BRIEF DESCRIPTION OF DRAWINGS

[0029] The present disclosure will be further described in detail below according to the drawings and examples.

[0030] Fig. 1 is a structural schematic diagram of one embodiment of the gas pressure liquid level meter according to the present disclosure;

[0031] Fig. 2 is a vertical sectional view of the gas pressure liquid level meter shown in Fig. 1;

[0032] Fig. 3 is an exploded schematic diagram of the gas pressure liquid level meter shown in Fig. 1 in a state of hiding the gas guide pipe;

[0033] Fig. 4 is a vertical sectional view of the gas pressure liquid level meter shown in Fig. 1 in a state of hiding the gas guide pipe;

[0034] Fig. 5 is an enlarged view of the area A in Fig. 4;

[0035] Fig. 6 is an enlarged view of the area B in Fig. 4;

[0036] Fig. 7 is a structural schematic diagram of the top side of the shell base according to the present disclosure;

[0037] Fig. 8 is a structural schematic diagram of the bottom side of the shell base according to the present disclosure;

[0038] Fig. 9 is a structural schematic diagram of the shell base and the second waterproof pipe in a connected state according to the present disclosure;

[0039] Fig. 10 is a structural schematic diagram of the shell upper cover according to the present disclosure;

[0040] Fig. 11 is a structural schematic diagram of another embodiment of the gas pressure liquid level meter according to the present disclosure;

[0041] Fig. 12 is a vertical sectional view of the gas pressure liquid level meter shown in Fig. 11;

[0042] Fig. 13 is a vertical sectional view of another embodiment of the shell of the gas pressure liquid level meter according to the present disclosure.

[0043] Fig. 1 is a structural schematic diagram of one embodiment of the gas pressure liquid level meter according to the present disclosure;

[0044] 1, housing; 11, housing base; 111, support boss; 112, airtight groove; 113, airtight ring; 1131, convex rib; 114, clamping pipe; 1141, arc-shaped clamping pipe plate; 1142, clamping block; 12, housing upper cover; 13, side wall; 131, second wall plate; 132, first wall plate; 1321, second wall part; 1322, first wall part; 1323, step part; 1324, annular groove; 1325, waterproof ring; 14, top cover plate; 15, inner partition plate; 151, annular flange; 16, device mounting cavity; 161, second induction air chamber; 1611, inductor mounting area; 1612, bypass narrow air channel; 17, air permeation chamber; 18, second air permeation hole; 19, first air permeation hole; 2, connector; 21, mounting seat; 211, first induction air chamber; 22, connecting head; 221, second connecting column; 222, first connecting column; 223, air passage; 23, flexible pipe; 3, air pressure sensor; 31, sensor main body; 32, sensor cannula; 33, sealing ring; 4, first waterproof pipe; 5, air guide pipe; 6, second waterproof pipe; 7, main control circuit board. DETAILED DESCRIPTION

[0045] In order to make the technical problems solved by the present disclosure, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present disclosure are described in further detail below. Obviously, the described embodiments are only some of the embodiments of the present disclosure, not all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present disclosure.

[0046] In the description of the present disclosure, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrated; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; 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 disclosure can be understood according to the specific circumstances.

[0047] In the present disclosure, unless explicitly specified and limited, a second feature is "on" or "under" a first feature can include that the second and first features are in direct contact, or can include that the second and first features are not in direct contact but are in contact through another feature between them. Moreover, the second feature "on", "above" and "over" the first feature includes that the second feature is directly above and obliquely above the first feature, or simply means that the second feature is higher in horizontal height than the first feature. The second feature "under", "below" and "underneath" the first feature includes that the second feature is directly below and obliquely below the first feature, or simply means that the second feature is lower in horizontal height than the first feature.

[0048] In the field of plant protection, a gas pressure liquid level meter is generally 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.

[0049] Under normal circumstances, since the gas pressure liquid level meter is located at the top of the pesticide liquid tank, the pesticide liquid in the pesticide liquid tank cannot flow back to contact the gas pressure liquid level meter through the gas inlet pipe. Moreover, in order to meet the normal ventilation requirements, the gas pressure sensor 3 cannot be sealed from the gas inlet pipe. Therefore, the gas pressure sensor 3 in the related art is generally exposed to the air communicating with the gas inlet pipe. This leads to the problem that when the pesticide liquid tank is accidentally tipped over or even inverted, the pesticide liquid is easy to flow back and contact the gas pressure sensor 3 through the gas inlet pipe, thereby causing the gas pressure sensor 3 to be damaged by water. Therefore, in the gas pressure liquid level meter in the related art, there is a risk of water entering the side of the gas pressure sensor 3 connected to the gas inlet pipe.

[0050] In order to overcome the above technical problems, the present embodiment provides a gas pressure liquid level meter which can meet the requirement of the gas pressure sensor 3 sensing the gas pressure on the liquid side, and at the same time, can provide reliable waterproof function in emergency to provide reliable protection for the gas pressure sensor 3.

[0051] The gas pressure liquid level meter of the present embodiment at least includes a gas pressure sensor 3, a first waterproof pipe 4 and a gas guide pipe 5. The first waterproof pipe 4 communicates with the gas pressure sensor 3. The gas guide pipe 5 has an inner pipe diameter greater than that of the first waterproof pipe 4. One end of the gas guide pipe 5 communicates with the gas pressure sensor 3 through the first waterproof pipe 4, and the other end is used to extend into the liquid to sense the water pressure.

[0052] 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 first waterproof pipe 4, the air pressure sensor 3, the first 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.

[0053] In an embodiment, the waterproof principle of the first waterproof pipe 4 is similar to that of a capillary tube. When the external liquid enters the first waterproof pipe 4 through the end far from the air pressure sensor 3, the liquid is easy to form a water column in the first waterproof pipe 4 under the action of the liquid tension, which can isolate the space between the air pressure sensor 3 and the first waterproof pipe 4 from the outside, equivalent to forming a blockage to prevent the air between the air pressure sensor 3 and the first waterproof pipe 4 from being discharged. When the pressure of the external liquid balances with the air pressure in the first waterproof pipe 4, the liquid cannot continue to enter, so the purpose of waterproofing the air pressure sensor 3 is achieved.

[0054] It should be noted that the first waterproof pipe 4 provided in the embodiment 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 first waterproof pipe 4 is to utilize the tension of the liquid itself. When the liquid enters the first waterproof pipe 4, it is easy to form a water column in the first 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 first 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 provided in the disclosure plays a crucial role as an intermediate bridge connecting the first 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 liquid tension. When the liquid level changes, the liquid level in the air guide pipe 5 will also sensitively follow the change, so the air pressure in the air guide pipe 5 can accurately reflect the liquid pressure. The first waterproof pipe 4 is connected to the air guide pipe 5, so the air pressure in the first waterproof pipe 4 can also accurately reflect the liquid pressure. In summary, on the basis of the first 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 first waterproof pipe 4 does not contact water in the normal use state, thereby avoiding the problem of affecting the liquid level detection accuracy after the first waterproof pipe 4 is filled with water.

[0055] 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 first 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 first 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.

[0056] In summary, based on the air pressure liquid level gauge of the embodiment, the first 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 first 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 first 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 first waterproof pipe 4 away from the air pressure sensor 3, the liquid is easy to form a water column in the first waterproof pipe 4 under the action of liquid tension. The water column can isolate the space between the air pressure sensor 3 and the first waterproof pipe 4 from the outside, which is equivalent to forming a blockage to prevent air between the air pressure sensor 3 and the first waterproof pipe 4 from being discharged. When the pressure of the external liquid balances with the air pressure in the first waterproof pipe 4, the liquid cannot continue to enter, so the purpose of waterproofing the air pressure sensor 3 is achieved.

[0057] 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.

[0058] 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 first 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.

[0059] When the inventor initially considered waterproofing the air pressure sensor 3 of the liquid level meter, the most direct idea was to set 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 waterproofing. However, in actual application, the inventor 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 is dried and then 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 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, thereby causing a certain burden to the user in use. After repeated experiments and research, the inventor creatively designed the air-permeable waterproof structure with the first waterproof pipe 4 of the present embodiment, and the first waterproof pipe 4 is a transparent pipe. Before use, the user can directly observe whether water has entered the first waterproof pipe 4, and when water is found to have entered, the water in the first waterproof pipe 4 can be drained by swinging or flicking the first waterproof pipe 4. Compared with the waterproofing mode using the waterproof air-permeable valve, the first waterproof pipe 4 of the present solution is more user-friendly in use.

[0060] 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 first sensing air chamber 211; the air pressure sensor 3 comprises a first sensitive element for sensing the air pressure inside the first sensing air chamber 211, and the first waterproof pipe 4 is connected to the connector 2 and communicates with the first sensing air chamber 211.

[0061] 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 first waterproof pipe 4. Importantly, the connector 2 can provide a closed first sensing air chamber 211 inside, which is isolated from the outside and communicates with the first waterproof pipe 4 and the air guide pipe 5. The air pressure in the first 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 connector 2 provides a reliable bridge for the connection between the air pressure sensor 3 and the first waterproof pipe 4, and effectively guarantees the air tightness of the connection structure.

[0062] In specific implementation, the air pressure sensor 3 can be completely or partially installed into the first sensing air chamber 211; or the air pressure sensor 3 can be installed on the outer surface of the connector 2 (i.e., the air pressure sensor 3 does not extend into the first sensing air chamber 211), as long as the first sensitive element thereon can be aligned towards the first sensing air chamber 211.

[0063] In another embodiment, the air pressure sensor 3 comprises a sensor body 31 and a sensor cannula 32, the first sensitive element is aligned with a lumen of the sensor cannula 32; the end of the first waterproof pipe 4 is directly sleeved to the sensor cannula 32, so that the first sensitive element can accurately sense the air pressure in the first waterproof pipe 4.

[0064] Regarding the connection arrangement of the first waterproof pipe 4 and the air guide pipe 5, in an embodiment, referring to FIG. 2 or FIG. 12, the connector 2 comprises a connecting head 22, the connecting head 22 comprises a first connecting column 222 and a second connecting column 221 connected to each other, the connecting head 22 is provided with an air passage 223 penetrating through the first connecting column 222 and the second connecting column 221, the air passage 223 communicates with the first sensing air chamber 211; the first waterproof pipe 4 is connected to the second connecting column 221, and the air guide pipe 5 is sleeved outside the first waterproof pipe 4 and connected to the first connecting column 222.

[0065] In this embodiment, the first connecting column 222 and the second connecting column 221 are arranged in the connecting head 22 and are used to connect the air guide pipe 5 and the first waterproof pipe 4 respectively, so the diameter of the first connecting column 222 needs to be arranged corresponding to the air guide pipe 5, and the diameter of the second connecting column 221 needs to be arranged corresponding to the first waterproof pipe 4. The key of this structure is to realize the sleeving structure of the air guide pipe 5 and the first waterproof pipe 4, that is, the first waterproof pipe 4 is inserted into the air guide pipe 5. When the air pressure liquid level meter is inverted, the liquid will first fill the space between the first waterproof pipe 4 and the air guide pipe 5, and only when the height of the liquid exceeds the height of the free end of the first waterproof pipe 4, the liquid can enter the first waterproof pipe 4. The application advantage is extremely obvious in 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 enter through the free end of the air guide pipe 5, and the small amount of liquid will be stored in the space between the first waterproof pipe 4 and the air guide pipe 5 after entering. In this way, the problem of water entering the first waterproof pipe 4 can be avoided, and the user does not need to remove and drain the first waterproof pipe 4 in the later use, so as to facilitate the use of the user.

[0066] In an embodiment, the first waterproof pipe 4 is sleeved on the second connecting column 221; and / or, the air guide pipe 5 is sleeved on the first connecting column 222.

[0067] The sleeving connection structure further enhances the sealing and stability of the connection between the pipe and the connector 2.

[0068] Preferably, the first connecting column 222 and the second connecting column 221 are both arranged as a pagoda connecting head 22 to improve the reliability of the connection.

[0069] 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 the connecting head 22, the first sensing air chamber 211 is arranged in the mounting base 21, and the connecting head 22 is in an integrated structure with the mounting base 21.

[0070] The mounting base 21 can be used to stably mount the air pressure sensor 3. The first sensing air chamber 211 is arranged in the mounting base 21, and after the air pressure sensor 3 is mounted, the first sensitive element thereon can be aligned towards the first sensing air chamber 211.

[0071] 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 present embodiment can be reliably mounted on the liquid tank.

[0072] 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, ensuring 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 production costs and improving 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 ensures the accuracy of air pressure transmission.

[0073] 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 the connecting head 22, the first 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 first sensing air chamber 211 and the air passage 223.

[0074] 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 connecting the mounting base 21 and the connecting head 22 not only realizes the conduction between the first sensing air chamber 211 and the air passage 223, but also endows the connector 2 with unique convenience in maintenance.

[0075] The mounting base 21 can be used to mount the air pressure sensor 3 stably. The first sensing air chamber 211 is arranged on the mounting base 21, and the first sensing element of the air pressure sensor 3 can be aligned to the first 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 first 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 first sensing air chamber 211 and be accurately sensed by the air pressure sensor 3. When the first waterproof pipe 4 is filled with water, the conventional connector 2 needs to be disassembled for drainage, but 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 first waterproof pipe 4, thereby quickly restoring the normal use function of the connector 2. This design greatly simplifies the maintenance process and improves the operation convenience of the user.

[0076] 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.

[0077] 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.

[0078] In an embodiment, the first waterproof pipe 4 uses the surface tension principle of water to form a water column in the first waterproof pipe 4 when water enters to prevent external water from further invading the air pressure sensor 3 through the first waterproof pipe 4.

[0079] Specifically, the waterproof function of the first waterproof pipe 4 is realized by using the liquid surface tension principle. Only the inner diameter of the first waterproof pipe 4 needs to be small enough to form a water column when water enters. This structure of the first waterproof pipe 4 has the advantages of simple structure and low cost.

[0080] In an embodiment, the inner diameter of the first waterproof pipe 4 is 1.5-3.5mm.

[0081] Setting the inner diameter of the first waterproof pipe 4 to 1.5-3.5mm can meet the normal air permeability requirement and realize the function of forming a water column in the first waterproof pipe 4 by using the liquid surface tension to achieve waterproof.

[0082] Further preferably, the inner diameter of the first waterproof pipe 4 is 2.5-2.7mm. This size range can provide stable air permeability and ensure the stable formation of a water column when water enters.

[0083] In an embodiment, the inner diameter of the air guide pipe 5 is 5-12mm.

[0084] 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.

[0085] 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 first sensitive element is arranged in the sensor cannula 32; the connector 2 is provided with a sensing connection hole communicating with the first sensing air chamber 211, and the sensor cannula 32 is inserted into the sensing connection hole, so that the first sensitive element can sense the internal air pressure of the first sensing air chamber 211.

[0086] The specially designed sensing connection hole on the connector 2 is a bridge connecting the first sensing air chamber 211 and the sensor cannula 32. 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 first sensitive element can directly face the inside of the first sensing air chamber 211 and sense the air pressure change in the first sensing air chamber 211.

[0087] 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.

[0088] The sealing ring 33 is placed in the sensing connection hole. 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 first sensing air chamber 211, so that the air pressure in the first sensing air chamber 211 can accurately reflect the liquid pressure, thereby ensuring the accuracy of the liquid level detection.

[0089] In an embodiment, the air pressure sensor 3 further includes a second sensitive element for sensing the atmospheric pressure.

[0090] That is, this air pressure sensor 3 is a relative sensor. When the atmospheric pressure changes, it can also accurately detect the liquid level height.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] On the other hand, the embodiment also provides a liquid storage device, which comprises a liquid storage tank and the air pressure liquid level meter described above, wherein 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 end of the connector 2.

[0095] Similarly, the air pressure liquid level meter in the liquid storage device of the embodiment has the advantage of good waterproof capability.

[0096] In another aspect, a plant protection equipment is provided, which comprises a carrier, a spraying system, and the liquid storage device described above, wherein 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.

[0097] The carrier can be an unmanned vehicle, an unmanned aerial vehicle, a manually driven vehicle, etc.

[0098] The spraying system comprises a pumping device and an atomizer, etc., and 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.

[0099] 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.

[0100] In order to ensure the detection accuracy, the air pressure sensor 3 in the air pressure liquid level meter installed on the pesticide liquid tank in the related art is generally a relative air pressure sensor 3. The relative air pressure sensor 3 has at least two air pressure detection points, one of which is used to detect the air pressure in the air pipe, and the other of which 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 that the change of atmospheric pressure affects the liquid level detection accuracy 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 permeation 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. that are usually contacted are easy to invade the inside of the liquid level meter through the gas permeation hole, which in turn leads to the problem that the internal air pressure sensor 3 and the circuit board of the liquid level meter in the related art are easy to be damaged by water.

[0101] 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.

[0102] 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 to 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 second air permeation hole 18 communicating 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 second sensitive element for sensing the air pressure of the device mounting cavity 16.

[0103] 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.

[0104] The second 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.

[0105] 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 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 communicating with the air permeation chamber 17 can be arranged on the pesticide liquid tank.

[0106] It can be understood that after the application of the air pressure liquid level meter of the embodiment is installed, the inner partition plate 15 is located above the air chamber 17, that is, the second 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 is connected to the air chamber 17, it is difficult for the water to splash upward in the air chamber 17 and pass through the second air hole 18 into the device mounting cavity 16.

[0107] In summary, based on the air pressure liquid level meter of the embodiment, the inner partition plate 15 is provided in the side wall 13 and is 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 second 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 purpose of enabling the air pressure sensor in the device mounting cavity 16 to sense the atmospheric pressure is achieved. 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 second air hole 18 into the device mounting cavity 16, so that the device (such as a circuit board, an air pressure sensor 3, or the like) installed in the device mounting cavity 16 can be effectively protected from splashing water, and the problem of damage to the internal device due to water is avoided.

[0108] The air pressure liquid level meter of the embodiment can be applied in various scenarios that require detection of the liquid level, such as but not limited to industrial facilities such as reaction kettles and filter tanks; household electrical appliances such as but not limited to washing machines and dishwashers; and plant protection equipment such as but not limited to agricultural liquid tanks and water tanks.

[0109] The air pressure liquid level meter of the 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 is difficult to avoid rain, and the user often needs to clean the air pressure liquid level meter after use. The waterproof structure of the embodiment can meet the needs of the plant protection liquid tank in various scenarios of splashing water.

[0110] In one embodiment, in combination with FIGS. 4 and 9, the air chamber 17 is provided with a second waterproof pipe 6, one end of the second waterproof pipe 6 is connected to the second 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 second waterproof pipe 6.

[0111] Wherein, under normal conditions, the second 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 second waterproof pipe 6 can realize the waterproof effect of the related art, and the waterproof principle of the second waterproof pipe 6 is similar to that of a capillary tube. When the external liquid enters the second waterproof pipe 6 through the end of the second waterproof pipe 6 away from the device mounting cavity 16, the liquid is easy to form a water column in the second waterproof pipe 6 under the action of liquid tension. The water column can isolate the space between the device mounting cavity 16 and the second waterproof pipe 6 from the outside, which is equivalent to forming a blockage, preventing the air in the air pressure sensor 3 and the second waterproof pipe 6 from being discharged. When the pressure of the external liquid is balanced with the air pressure in the second waterproof pipe 6, the liquid cannot continue to enter, so as to achieve the purpose of waterproofing the air pressure sensor 3.

[0112] It should be noted that the purpose of setting the second 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 second waterproof pipe 6. When encountering a water immersion situation, based on the setting of the second waterproof pipe 6, the external water can be prevented from entering the device mounting cavity 16 through the second waterproof pipe 6, realizing the function of providing normal waterproofing in a water immersion situation. The air pressure liquid level meter with the second waterproof pipe 6 has a particularly obvious 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 the waterproof function 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 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.

[0113] In addition, when the second waterproof pipe 6 of the air pressure liquid level meter is blocked by water, the water in the second waterproof pipe 6 can be shaken out by swinging or knocking, and the second waterproof pipe 6 can be restored to use.

[0114] When the inventors initially considered waterproofing the air pressure sensor 3 of the liquid level meter, they directly thought of setting a waterproof air permeable valve at the air permeable opening of the shell. The waterproof air permeable valve has the function of air permeability and water impermeability, which can exactly meet the demand for the function of air permeability and water impermeability. However, in actual application, the inventors found that when the air permeable film in the waterproof air permeable valve is sticky with water, the entire waterproof air permeable valve needs to be disassembled, the air permeable film needs to be dried, and then the waterproof air permeable valve needs to be reassembled. The drainage process is relatively complex, and more importantly, since the air permeable film 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 film is sticky with water, and often needs to disassemble the waterproof air permeable valve to check the air permeable film during use, thereby causing a certain burden to the user. After repeated experiments and research, the inventors of the present disclosure creatively designed the air permeable and waterproof structure with the second waterproof pipe 6 of the embodiment of the present disclosure. The second waterproof pipe 6 is made of a transparent pipe. Before use, the user can directly observe whether water has entered the second waterproof pipe 6. When water is found to have entered, the water in the second waterproof pipe 6 can be drained by swinging or flicking the second waterproof pipe 6. Compared with the waterproof mode using the waterproof air permeable valve, the second waterproof pipe 6 of the present scheme is more user-friendly in use.

[0115] In an embodiment, the second waterproof pipe 6 includes a second waterproof pipe main body and an air permeable connector connected to each other, and the air permeable connector is connected to the second air permeable hole 18 in a plug-in manner.

[0116] The second waterproof pipe 6 is divided into a second waterproof pipe main body and an air permeable connector, realizing a modular design. This design makes it possible to more flexibly handle different components during production, installation and maintenance, thereby improving the overall work efficiency and convenience. The air permeable connector is connected to the second air permeable hole 18 in a plug-in manner. This connection method is not only simple and fast, but also can ensure the sealing and stability of the connection. The plug-in connection also facilitates disassembly, maintenance and replacement when needed, thereby reducing the maintenance cost.

[0117] In an embodiment, a flexible pipe 23 is connected between the second waterproof pipe main body and the air permeable connector, and the inner diameter of the flexible pipe 23 is greater than the inner diameter of the second waterproof pipe main body.

[0118] The flexible pipe 23 is provided to give the second waterproof pipe 6 unique maintenance convenience. Specifically, when the second waterproof pipe 6 is filled with water, the user can directly squeeze the flexible pipe 23 to use air pressure to squeeze out the water column in the second 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 operation convenience of the user.

[0119] In an embodiment, in combination with FIG. 8 and FIG. 9, the inner partition plate 15 is provided with a clamping pipe element 114 on the side facing away from the top cover plate 14, and the second waterproof pipe 6 is clamped to the clamping pipe element 114.

[0120] The design of the clamping pipe element 114 enables the second waterproof pipe 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 second waterproof pipe 6 during long-term use, preventing water or air leakage problems caused by unstable connection.

[0121] 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 pipe 5, and the second waterproof pipe 6 is wound around the connector 2.

[0122] Specifically, the air pressure sensor 3 of the present embodiment adopts a relative air pressure sensor 3, which at least has a second sensitive element and a first sensitive element. The second sensitive element is used to sense the atmospheric pressure, and the first sensitive element is used to sense the pressure of the gas chamber connected to the liquid. In order to realize the respective functions of the second sensitive element and the first sensitive element, in the present embodiment, one side of the inner partition plate 15 is provided with a connector 2, and the connector 2 is connected with an air guide pipe 5 that can extend into the liquid. The connector 2 is provided with a first sensing gas chamber 211 that communicates with the air guide pipe 5. After the air pressure sensor 3 is fixedly installed in the device mounting cavity 16, the second sensitive element is located on the side of the device mounting cavity 16, and the first sensitive element is directed towards the first sensing gas chamber 211. After the air pressure sensor 3 is installed, the first sensing gas chamber 211 and the device mounting cavity 16 are separated. As long as the device mounting cavity 16 is connected with the atmosphere, the second sensitive element can sense the atmospheric pressure, and the first sensitive element can sense the air pressure on the liquid side. Preferably, referring to FIG. 5, in order to effectively isolate the first 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 pipe 32. The second sensitive element is located on the side of the sensor main body 31, and the first sensitive element is aligned with the lumen of the sensor insertion pipe 32. A sealing ring 33 is provided at the position of the first sensing gas chamber 211 in the device mounting cavity 16, and the sensor insertion pipe 32 is inserted into the sealing ring 33. In this way, the first 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.

[0123] When the bubble water accident occurs, the external water enters into the second waterproof pipe 6 and forms a water column in the second waterproof pipe 6. The deeper the bubble water is, the greater the external water pressure is, the greater the pressure applied by the water column to the device mounting cavity 16 is, the longer the water column is, and the greater the compression degree of the gas in the device mounting cavity 16 is. 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. Therefore, the length of the water column that can be formed in the second 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 is, the deeper the water in which the device mounting cavity 16 can maintain effective waterproofing is, that is, the better the anti-deep water waterproofing capability is. In the present scheme, the second waterproof pipe 6 is arranged in a spiral shape around the connector 2. The limited space in the air vent chamber 17 can be effectively utilized to arrange the second waterproof pipe 6. Importantly, the spiral-shaped second waterproof pipe 6 has the advantage of long length while occupying a small space. This is conducive to obtaining a second waterproof pipe 6 with a longer length and achieving better anti-deep water waterproofing capability.

[0124] In an embodiment, in combination with FIG. 8, the clamping pipe piece 114 includes an arc-shaped clamping pipe plate 1141 arranged on the side of the connector 2 away from the second air vent hole 18. A second clamping pipe groove capable of clamping the second waterproof pipe 6 is formed between the arc-shaped clamping pipe plate 1141 and the connector 2.

[0125] Since the second 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 second waterproof pipe 6, and the arc-shaped clamping pipe plate 1141 can tightly fit the second waterproof pipe 6 to provide uniform clamping force and reduce the problem of preventing air passage caused by the bending of the middle part of the second waterproof pipe 6. Moreover, the arc-shaped clamping pipe plate 1141 can utilize the outer wall of the connector 2 to fix the second waterproof pipe 6, thereby achieving the purpose of simplifying the structure of the clamping pipe piece 114.

[0126] In an embodiment, the clamping pipe piece 114 includes a clamping block 1142 arranged close to the second air vent hole 18. The clamping block 1142 is provided with a first clamping pipe groove capable of clamping the second waterproof pipe 6.

[0127] Specifically, at the position close to the second air vent hole 18, the second waterproof pipe 6 needs to be avoided. Therefore, the clamping block 1142 occupying a smaller space is arranged to provide fixation, that is, to meet the demand of fixing the second waterproof pipe 6 and to avoid the problem of mutual extrusion caused by the waterproof pipes themselves.

[0128] In an embodiment, the second waterproof pipe 6 utilizes the principle of surface tension of water to form a water column in the second waterproof pipe 6 when water enters to prevent the external water from further invading the air pressure sensor 3 through the second waterproof pipe 6.

[0129] Specifically, the second waterproof pipe 6 realizes the waterproof function by using the principle of liquid surface tension. Only the inner diameter of the second waterproof pipe 6 needs to be small enough to form a water column when water enters, and the second waterproof pipe 6 of this structure has the advantages of simple structure and low cost.

[0130] In an embodiment, the inner diameter of the second waterproof pipe 6 is 1.5-3.5mm.

[0131] Setting the inner diameter of the second 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 second waterproof pipe 6 by using the liquid surface tension can realize the waterproof function.

[0132] Further preferably, the inner diameter of the second waterproof pipe 6 is 2.5-2.7mm, which is a small size range that can provide stable air permeability function and ensure the stable formation of a water column when water enters.

[0133] In an embodiment, referring to FIGS. 7-8, the side wall 13 is provided with a first air permeable hole 19 communicating with the air permeable chamber 17, so that the air permeable chamber 17 is in communication with the atmosphere.

[0134] By setting the first air permeable hole 19 in the side wall 13 to realize air permeability, the liquid tank to 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 liquid tank of the related technology and used normally without any improvement of the liquid tank.

[0135] 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 upper cover 12, the shell base 11 includes a second surrounding wall plate 131 and the inner partition plate 15 connected together; the shell upper cover 12 includes a first surrounding wall plate 132 and the top cover plate 14 connected together, the shell upper cover 12 is buckled on the shell base 11, the second surrounding wall plate 131 and the first surrounding wall plate 132 are connected to form the side wall 13, and the first air permeable hole 19 is arranged on the second surrounding wall plate 131.

[0136] The shell 1 is divided into two modules, the shell base 11 and the shell upper cover 12. This design allows each part to be manufactured and processed separately, and then assembled. This modular design not only improves production efficiency, but also facilitates subsequent maintenance and replacement. The shell upper cover 12 is buckled on the shell base 11, and a proper fixing method (such as buckle, screw, etc.) is used to ensure the tight connection between the two. This assembly method is not only simple and fast, but also can ensure the sealing and stability of the shell 1.

[0137] In one embodiment, as shown in FIGS. 6 and 7, the inner partition plate 15 is arranged protruding towards the side of the top cover plate 14 relative to the second surrounding wall plate 131, the inner cavity of the first surrounding wall plate 132 corresponds to the size of the inner partition plate 15, and the inner partition plate 15 is embedded in the first surrounding wall plate 132.

[0138] Since the inner partition plate 15 is embedded in the first surrounding wall plate 132, when the shell upper cover 12 is buckled on the shell base 11, the first surrounding wall plate 132 is automatically aligned with the second surrounding wall plate 131 and in close contact, which simplifies the assembly process, reduces the requirement for assembly accuracy, and improves the production efficiency. The protruding arrangement of the inner partition plate 15 towards the side of the top cover plate 14 relative to the second surrounding wall plate 131 and the embedding of the inner partition plate 15 in the first surrounding wall plate 132 enable the inner partition plate 15 to serve as a positioning and fixing point between the shell upper cover 12 and the shell base 11 during the assembly process, thereby enhancing the overall structural stability of the shell 1. Through the close cooperation between the inner partition plate 15 and the first surrounding wall plate 132 and the contact between the inner partition plate 15 and the second surrounding wall plate 131, a continuous sealing barrier is formed between the air 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 air pressure liquid level meter.

[0139] In one embodiment, as shown in FIG. 6, the first surrounding wall plate 132 includes a second surrounding wall portion 1321 and a first surrounding wall portion 1322 connected in a stepped structure, a step portion 1323 parallel to the inner partition plate 15 is formed between the second surrounding wall portion 1321 and the first surrounding wall portion 1322, a waterproof ring 1325 abutting against the step portion 1323 is installed on the inner side of the second surrounding wall portion 1321, and the inner partition plate 15 is embedded in the second surrounding wall portion 1321 and abuts against the waterproof ring 1325.

[0140] The waterproof ring 1325 is installed on the inner side of the second 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 in the second 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 the leakage of liquid or gas from the gaps of the shell 1.

[0141] In one embodiment, the step portion 1323 is provided with an annular groove 1324, and the waterproof ring 1325 is embeddedly installed in the annular groove 1324.

[0142] The stepped portion 1323 is provided with an annular groove 1324, which is specially designed for installing a waterproof ring 1325. The annular groove 1324 is matched with the waterproof ring 1325 in shape and size, so as to ensure that the waterproof ring 1325 can be stably embedded in the annular groove 1324. The waterproof ring 1325 is embeddedly installed in the annular groove 1324, which not only simplifies the assembly process, but also forms a close fit between the waterproof ring 1325 and the stepped portion 1323, thereby improving the sealing effect.

[0143] 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.

[0144] 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 closely abuts against the waterproof ring 1325. Such an embedded design forms a continuous and close sealing structure among the inner partition plate 15, the waterproof ring 1325 and the stepped portion 1323, further enhances the sealing effect of the waterproof ring 1325 and ensures the dryness and cleanliness of the inside of the shell 1.

[0145] Regarding the setting 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.

[0146] This structure can also achieve the structure that the device mounting cavity 16 and the air chamber 17 are respectively formed above and below the inner partition plate 15, and achieve the waterproof purpose.

[0147] 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.

[0148] 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.

[0149] On the other hand, a liquid storage device is provided, which comprises a liquid storage tank and the 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.

[0150] Similarly, the air pressure liquid level meter in the liquid storage device of the embodiment has the advantage of good waterproof capability.

[0151] In another aspect, a plant protection device 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 and atomize the pesticide in the liquid storage device.

[0152] The carrier can be an unmanned vehicle, an unmanned aerial vehicle, a manually driven vehicle, etc.

[0153] The spraying system includes 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 the pesticide in the liquid storage tank, and the pesticide is uniformly sprayed on crops after being atomized by the atomizer. Based on the carrying of the carrier, mobile spraying operation can be realized.

[0154] Based on the liquid storage device of the embodiment, the air pressure liquid level meter in the plant protection device of the embodiment has the advantages of strong waterproofness and long service life.

[0155] In order to ensure the detection accuracy, the air pressure sensor 3 in the air pressure liquid level meter installed on the pesticide tank is generally a relative air pressure sensor 3, which has at least two air pressure detection points, one of which is used to detect the air pressure in the air pipe, and the other 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 caused by 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, 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 an outdoor environment, rainwater, river water and cleaning water, etc. are easily invaded into the inside of the liquid level meter through the gas permeable hole, which further causes the internal air pressure sensor 3 and circuit board of the liquid level meter of the related art to be easily damaged by water.

[0156] In order to overcome the above technical problems, referring to FIG. 4, the embodiment further provides another air pressure liquid level meter, which can effectively prevent the external splashing water such as rainwater and cleaning water from entering the inside of the air pressure liquid level meter and causing the internal electronic devices to be damaged by water. 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 meters of any one or more of the above-mentioned embodiments.

[0157] The air pressure liquid level gauge comprises a shell 1, an air pressure sensor 3 and a second 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 separate second sensing air chamber 161. The shell 1 is further provided with a second air hole 18 communicating with the second sensing air 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 second sensing air chamber 161. One end of the second waterproof pipe 6 is connected to the second air hole 18, and the other end is in communication with the atmospheric pressure. The second sensing air chamber 161 is communicated with the atmosphere through the second waterproof pipe 6.

[0158] The device mounting cavity 16 is used for mounting the air pressure sensor 3, the main control circuit board 7 and other devices, and the shell 1 can provide sufficient protection. The second sensing air 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 second sensitive element for sensing the air pressure in the second sensing air chamber 161. When the air pressure sensor 3 is mounted, it can be mounted in the second sensing air chamber 161 or outside the second sensing air chamber 161, as long as the second sensitive element on the air pressure sensor 3 can be aligned and directed towards the second sensing air chamber 161.

[0159] Under normal conditions, the second waterproof pipe 6 can communicate the second sensing air chamber 161 with the outside world, realizing the communication between the second sensing air chamber 161 and the atmosphere. When encountering water, effective waterproof can be realized through the second waterproof pipe 6. The waterproof principle of the second waterproof pipe 6 is similar to that of a capillary tube. When the external liquid enters the second waterproof pipe 6 through the end of the second waterproof pipe 6 far away from the second sensing air chamber 161, the liquid is easy to form a water column in the second waterproof pipe 6 under the action of liquid tension. The water column can isolate the space between the device mounting cavity 16 and the second 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 second waterproof pipe 6 from being discharged. When the pressure of the external liquid balances with the air pressure in the second waterproof pipe 6, the liquid cannot continue to enter, so as to achieve the purpose of waterproofing the air pressure sensor 3.

[0160] In summary, the gas pressure liquid level meter based on the embodiment is provided with a second independent sensing air chamber 161 in the device installation cavity 16 of the gas pressure liquid level meter, and a gas pressure sensor 3 capable of sensing the gas pressure of the second sensing air chamber 161 is arranged; the shell 1 of the gas pressure liquid level meter is provided with a second waterproof pipe 6 in communication with the second sensing air chamber 161 inside, and the second sensing air chamber 161 is in communication with the atmosphere through the second waterproof pipe 6, realizing the function of the gas pressure sensor 3 sensing the atmospheric pressure. The flow area of the second waterproof pipe 6 is small, similar to a capillary tube, when the external liquid enters the second waterproof pipe 6, the liquid is easy to form a water column in the second waterproof pipe 6 under the action of liquid tension, the water column can isolate the second sensing air chamber 161 from the outside, which is equivalent to forming a blockage to prevent the air in the second sensing air chamber 161 from being discharged, when the pressure of the external liquid balances with the air pressure in the second sensing air chamber 161, the liquid cannot continue to enter, so as to achieve the purpose of waterproofing the second 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, realize effective waterproofing, and provide effective protection for the gas pressure sensor 3 for sensing the gas pressure in the second sensing air chamber 161; in addition, since the second sensing air chamber 161 is provided for communication with the atmospheric pressure, the device installation cavity 16 does not need to provide air permeability, and 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.

[0161] The inventor found through in-depth research that when the water immersion accident occurs, the external water enters the second waterproof pipe 6 through the first air permeable hole 19 and forms a water column in the second waterproof pipe 6, the deeper the water immersion, the greater the external water pressure, and the greater the counterpressure required to be provided in the device installation cavity 16, so the water column needs to be compressed to a greater extent. It can be understood that the larger 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, control circuit boards and other devices need to be 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 and waterproofing capability, extending the second waterproof pipe 6 is one of the ways, however, the space available on the shell 1 for arranging the second waterproof pipe 6 is limited, and it is generally difficult to arrange a second waterproof pipe 6 with a very long length to provide sufficient waterproofing capability.

[0162] In order to overcome the above problems, the second 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, so that when water enters, the water column in the second waterproof pipe 6 can only compress the air in the second sensing air chamber 161, and it is easier to compress the gas in the second sensing air chamber 161 with smaller volume to have sufficient pressure compared with compressing the whole device mounting cavity 16. Therefore, based on this improvement, better deep water resistance can be achieved even if a shorter second waterproof pipe 6 is provided.

[0163] Based on the design of the second 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, water can be prevented from entering the second sensing air chamber 161 by the isolation of the second waterproof pipe 6. The air pressure liquid level meter is particularly advantageous in automatic spraying equipment carried by a drone, because the air pressure liquid level meter of the present solution can achieve effective waterproof function even if the whole air pressure liquid level meter is immersed in water. When the drone carrying the automatic spraying equipment performs plant protection work and the drone and the chemical tank fall into the water due to accidental falling when flying over the water surface, the air pressure liquid level meter can also prevent water from entering the inside.

[0164] In addition, when the second waterproof pipe 6 of the air pressure liquid level meter is blocked by water, the water in the second waterproof pipe 6 can be shaken out by shaking or knocking, and the second waterproof pipe 6 can be restored to use.

[0165] When the inventor 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 air permeability and water resistance, which can meet the demand for air permeability and water resistance. However, in actual application, the inventor found that when the air permeable film in the waterproof air valve is sticky, 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, and more importantly, since the air permeable film inside the waterproof air valve cannot be directly observed outside the waterproof air valve, the user often cannot judge whether the air permeable film is sticky, and often needs to disassemble the waterproof air valve to check the air permeable film, which causes a certain burden to the user. After many experiments and researches, the inventor creatively designed the air permeable and waterproof structure including the second waterproof pipe 6 of the present embodiment. The second waterproof pipe 6 is made of transparent pipe, so that the user can directly observe whether water has entered the second waterproof pipe 6 before use. When water is found, the water in the second waterproof pipe 6 can be drained by shaking or flicking the second waterproof pipe 6. Compared with the waterproof method using the waterproof air valve, the second waterproof pipe 6 of the present solution is more user-friendly.

[0166] In an embodiment, the air pressure sensor is installed in the second sensing air chamber 161, which includes a second sensing element for sensing the internal air pressure of the second sensing air chamber 161.

[0167] The air pressure sensor is installed in the second sensing air chamber 161, which is more convenient for sealing and isolating the second sensing air chamber 161. Moreover, the air pressure sensor can occupy most of the space in the second sensing air chamber 161, so as to greatly reduce the air volume of the second sensing air chamber 161, which is more conducive to improving the deep water resistance of the present scheme.

[0168] In an embodiment, in combination with FIGS. 3-4, the device mounting cavity 16 is installed with a master control circuit board 7, the shell 1 is provided with an air chamber groove located on one side of the device mounting cavity 16, and the master control circuit board 7 is fixed in the shell 1 and covers the air chamber groove to separate the second sensing air chamber 161.

[0169] The master 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 master 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 master control circuit board 7 naturally becomes a partition, which separates the device mounting cavity 16 into two parts: one part is the master 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 second sensing air chamber 161. Based on this, the independent second 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.

[0170] In an embodiment, in combination with FIGS. 3-4, the shell 1 includes a shell base 11 and a shell upper cover 12, the shell upper cover 12 covers the shell base 11, so as to form the device mounting cavity 16 between the shell base 11 and the shell upper cover 12; the air chamber groove is arranged on the shell base 11, and the master control circuit board 7 is fixed on the shell base 11.

[0171] 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 second sensing air chamber 161 from the device installation cavity 16.

[0172] In an embodiment, a gas-tight ring 113 is arranged between the main control circuit board 7 and the shell base 11, and the gas-tight ring 113 is arranged around the air chamber groove.

[0173] 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 second sensing air chamber 161.

[0174] 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 around the air chamber groove, and the protruding rib strip 1131 is arranged in at least two rows and is spaced apart.

[0175] The design of the protruding rib strip 1131 forms multiple sealing lines, which can more effectively block the penetration of water and gas, thereby effectively ensuring the air tightness of the second sensing air chamber 161.

[0176] In an embodiment, the shell base 11 is provided with a support boss 111 arranged around 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.

[0177] 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 additionally, the sealing effect of the gas-tight ring 113 is more significant.

[0178] In an embodiment, the shell base 11 is provided with a plurality of installation threaded holes arranged around the air chamber groove, and the main control circuit board 7 is provided with positioning holes corresponding to the installation threaded holes, and installation screws pass through the positioning holes and are threadedly locked to the installation threaded holes, so that the main control circuit board 7 is tightly pressed against the gas-tight ring 113.

[0179] 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. With the screwing of the screw, the main control circuit board 7 is gradually pressed on the shell base 11, and at the same time, the air-tight ring 113 is tightly pressed between the two. This pressing mode 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 repeated disassembly and maintenance.

[0180] Preferably, a plurality of circuit board locking platforms are arranged on the shell base 11, and the installation screw hole is arranged in the circuit board locking platform. 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.

[0181] In an embodiment, the side of the shell base 11 away from the shell upper cover 12 is provided with a connector 2 for connecting the air guide pipe 5, and the second 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 second air hole 18.

[0182] Specifically, the air pressure sensor 3 of the embodiment is a relative air pressure sensor 3, which at least has a second sensing element and a first sensing element. The second sensing element is used to sense the atmospheric pressure, and the first 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 second sensing element and the first sensing element, in the embodiment, one 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 first 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 second sensing element is just located at the side of the device installation cavity 16, and the first sensing element is just directed to the first sensing air chamber 211. After the air pressure sensor 3 is installed, the first sensing air chamber 211 and the device installation cavity 16 are just separated. As long as the device installation cavity 16 is communicated with the atmosphere, the second sensing element can sense the atmospheric pressure, and the first sensing element can sense the air pressure on the liquid side. Preferably, referring to FIG. 5, in order to effectively isolate the first sensing air chamber 211 and the device installation cavity 16, the air pressure sensor 3 comprises a sensor main body 31 and a sensor insertion pipe 32. The second sensing element is located at the side of the sensor main body 31, and the first sensing element is aligned with the lumen of the sensor insertion pipe 32. A sealing ring 33 is arranged at the position of the first sensing air chamber 211 in the device installation cavity 16. The sensor insertion pipe 32 is inserted into the sealing ring 33. Thus, the first sensing air chamber 211 and the device installation cavity 16 can be effectively isolated based on the installation of the air pressure sensor 3 and the sealing ring 33.

[0183] The air chamber groove is divided into two parts, an inductor installation area 1611 and a bypass narrow air channel 1612. The air pressure sensor 3 is installed in the inductor installation area 1611, so that the sensor insertion pipe thereof can be directly aligned with the first 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 second air hole 18 with the inductor installation area 1611, so that the inductor installation area 1611 can be communicated with the second 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 second sensing air chamber 161 to the greatest extent on the basis of meeting the demand of air permeability, thereby realizing the purpose of improving the deep water resistance.

[0184] 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. The air chamber groove is arranged corresponding to the connector 2. The second air hole 18 is located at the side of the connector 2 and communicates with the air chamber groove.

[0185] In this embodiment, the second air hole 18 is directly arranged at the side of the connector 2, so that the second air 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.

[0186] In an embodiment, the side of the shell base 11 opposite to the shell upper cover 12 is provided with a ventilation chamber 17, and the second waterproof pipe 6 is coiled around the connector 2 in the ventilation chamber 17.

[0187] The ventilation chamber 17 is arranged on the side of the shell base 11 opposite to the shell upper cover 12, and the second waterproof pipe 6 is accommodated in the ventilation chamber 17, so that the second waterproof pipe 6 can be hidden and protected. In addition, when water immersion accident occurs, external water enters the second waterproof pipe 6 and forms a water column in the second 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, so the pressure in the device mounting cavity 16 increases at a greater rate. When the air pressure in the device mounting cavity 16 and the external water pressure are balanced, the water column cannot continue to extend inward, so the length of the water column that can be formed in the second waterproof pipe 6 determines the waterproof ability 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 waterproofing ability. The second 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 second waterproof pipe 6. Importantly, the coiled second waterproof pipe 6 has the advantage of long length while occupying a small space, which is conducive to obtaining a second waterproof pipe 6 with a longer length and better deep water resistance waterproofing ability.

[0188] In an embodiment, as shown in FIGS. 8-9, the side of the shell base 11 opposite to the shell upper cover 12 is provided with a pipe clamping member 114, and the second waterproof pipe 6 is clamped in the pipe clamping member 114.

[0189] The pipe clamping member 114 is designed to enable the second waterproof pipe 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 second waterproof pipe 6 during long-term use and prevents water or air leakage caused by unstable connection.

[0190] In an embodiment, the side of the shell base 11 is provided with a first ventilation hole 19, and the ventilation chamber 17 is in communication with the atmosphere through the first ventilation hole 19.

[0191] Specifically, the first air vent 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 application is installed, the device mounting cavity 16 is located above the air vent chamber 17, that is, the second air vent 18 is also located above the air vent chamber 17. When it rains, washes, or the like, even if the splashing water enters the air vent chamber 17 through the side wall 13 or the hole or groove of the liquid tank that communicates with the air vent chamber 17, it is difficult for the water to splash upward in the air vent chamber 17 and enter the device mounting cavity 16 through the second air vent 18.

[0192] In this way, the design structure of the shell itself can resist most of the splashing water to achieve the purpose of waterproofing. In most cases, water will not enter the second waterproof pipe 6, so the user can reduce the number of times of draining the second waterproof pipe 6. The main function of the second waterproof pipe 6 of the present embodiment becomes to provide a safety waterproof function. In the conventional use process, external splashing water cannot enter the second waterproof pipe 6. When encountering a water immersion situation, based on the arrangement of the second waterproof pipe 6, external water can be prevented from entering the device mounting cavity 16 through the second waterproof pipe 6, so that the normal waterproof function can be provided even in a water immersion situation. The air pressure liquid level meter application with the second waterproof pipe 6 has a great advantage in the automatic spraying equipment carried by the unmanned aerial vehicle. Even if the entire air pressure liquid level meter is immersed in water, the present scheme can also achieve effective waterproofing. When the unmanned aerial vehicle carrying the automatic spraying equipment performs plant protection work, and the unmanned aerial vehicle and the liquid tank accidentally fall into the water when flying over the water surface, water can also be prevented from entering the air pressure liquid level meter.

[0193] In an embodiment, the second waterproof pipe 6 utilizes the surface tension principle of water to form a water column in the second waterproof pipe 6 when water enters to prevent external water from further invading the air pressure sensor 3 through the second waterproof pipe 6.

[0194] Specifically, the liquid surface tension principle is used to achieve the waterproof function of the second waterproof pipe 6. Only the inner diameter of the second waterproof pipe 6 needs to be small enough to form a water column when water enters. The second waterproof pipe 6 of this structure has the advantages of simple structure and low cost.

[0195] In an embodiment, the inner diameter of the second waterproof pipe 6 is 1.5-3.5 mm.

[0196] Setting the inner diameter of the second waterproof pipe 6 to 1.5-3.5 mm can meet the normal air permeability requirement and at the same time achieve the function of forming a water column in the second waterproof pipe 6 by using the liquid surface tension to achieve waterproofing.

[0197] In another aspect, a liquid storage device is provided, comprising a liquid storage tank and the gas pressure liquid level gauge as described above, the housing 1 of the gas pressure liquid level gauge is installed on the top of the liquid storage tank, and the gas guide pipe 5 of the gas pressure liquid level gauge extends to the bottom of the liquid storage tank from the end of the housing 1.

[0198] Similarly, the gas pressure liquid level gauge in the liquid storage device of the present embodiment has the advantage of good waterproof capability.

[0199] In yet another aspect, a plant protection device is provided, comprising a carrier, a spraying system, and the liquid storage device as 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 pesticide liquid in the liquid storage device.

[0200] The carrier can be an unmanned vehicle, a drone, a manually driven vehicle, etc.

[0201] 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, and the pesticide liquid is atomized by the atomizer and uniformly sprayed on crops. Based on the carrying of the carrier, mobile spraying operation can be realized.

[0202] Based on the liquid storage device of the present embodiment, similarly, the gas pressure liquid level gauge in the plant protection device of the present embodiment has the advantages of strong waterproof capability and long service life.

[0203] In the description herein, it should be understood that the terms "upper", "lower", "left", "right", etc. 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 specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present disclosure. In addition, the terms "second", "first" are only used to distinguish in the description, and have no special meaning.

[0204] In the description of the present specification, the description referring to the terms "an embodiment", "an example", etc. 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 disclosure. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0205] In addition, it should be understood that although the present specification is described in terms of embodiments, each embodiment does not necessarily contain 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.

[0206] The technical principles of the present disclosure are described above in conjunction with specific embodiments. These descriptions are only to explain the principles of the present disclosure and cannot be explained as limitations on the protection scope of the present disclosure in any way. Based on the explanations here, other specific embodiments of the present disclosure can be thought of by those skilled in the art without creative labor, and these embodiments will all fall within the protection scope of the present disclosure.

Claims

1. A gas pressure liquid level gauge, characterized in that, The utility model relates to a waterproof air pressure sensor, comprising: an air pressure sensor (3); a first waterproof tube (4) in communication with the air pressure sensor (3); a gas guide tube (5) having an inner diameter larger than that of the first waterproof tube (4), one end of the gas guide tube (5) being in communication with the air pressure sensor (3) through the first waterproof tube (4), and the other end being used to extend into liquid to sense water pressure.

2. The air pressure liquid level gauge according to claim 1, characterized in that The utility model further comprises a connector (2) provided with a first air sensing chamber (211) inside; the air pressure sensor (3) comprises a first sensitive element for sensing air pressure inside the first air sensing chamber (211); and the first waterproof tube (4) is connected to the connector (2) and in communication with the first air sensing chamber (211).

3. The air pressure liquid level gauge according to claim 2, characterized in that The connector (2) comprises a connecting head (22) comprising a first connecting column (222) and a second connecting column (221) connected to each other, and the connecting head (22) is provided with an air passage (223) penetrating through the first connecting column (222) and the second connecting column (221), the air passage (223) being in communication with the first air sensing chamber (211); the first waterproof tube (4) is connected to the second connecting column (221), and the gas guide tube (5) is sleeved outside the first waterproof tube (4) and connected to the first connecting column (222).

4. The air pressure liquid level gauge according to claim 3, characterized in that The first waterproof tube (4) is sleeved on the second connecting column (221); and / or the gas guide tube (5) is sleeved on the first connecting column (222).

5. The air pressure liquid level gauge according to claim 3, wherein The connector (2) comprises a mounting seat (21) and the connecting head (22), and the first air sensing chamber (211) is arranged in the mounting seat (21), and the connecting head (22) is an integral structure with the mounting seat (21).

6. A gas pressure liquid level gauge according to any one of claims 2 to 5, characterised in that, The connector (2) comprises a mounting seat (21), a flexible tube (23) and a connecting head (22), the first air sensing chamber (211) is arranged in the mounting seat (21), and two ends of the flexible tube (23) are connected to the mounting seat (21) and the connecting head (22) respectively to lead through the air passage (223) in the first air sensing chamber (211) and the connecting head (22).

7. The air pressure liquid level gauge according to claim 6, characterized in that The connecting head (22) is provided with a third connecting column, the mounting seat (21) is provided with a fourth connecting column, and two ends of the flexible tube (23) are sleeved on the third connecting column and the fourth connecting column respectively.

8. A gas pressure liquid level gauge according to any one of claims 1 to 7, characterised in that, The first waterproof tube (4) utilizes the surface tension principle of water, and when water enters, a water column is formed in the first waterproof tube (4) to prevent external water from further invading the air pressure sensor (3) through the first waterproof tube (4).

9. The air pressure liquid level gauge according to claim 8, characterized in that The inner diameter of the first waterproof tube (4) is 1.5-3.5 mm.

10. A gas pressure liquid level gauge according to any one of claims 1 to 9, characterised in that, The inner diameter of the gas guide tube (5) is 5-12 mm.

11. A gas pressure liquid level gauge according to any one of claims 2 to 7, wherein The air pressure sensor (3) comprises a sensor main body (31) provided with a sensor insertion pipe (32) on one side; the first sensitive element is arranged in the sensor insertion pipe (32); the connector (2) is provided with a sensing connection hole communicating with the first sensing air chamber (211), and the sensor insertion pipe (32) is inserted into the sensing connection hole, so that the first sensitive element can sense the internal air pressure of the first sensing air chamber (211).

12. The air pressure liquid level gauge according to claim 11, characterized in that A sealing ring (33) is arranged in the sensing connection hole, and the sensor insertion pipe (32) is inserted into the sealing ring (33).

13. The air pressure liquid level gauge according to claim 11, wherein The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure.

14. The air pressure liquid level gauge according to claim 11, wherein The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure.

15. The gas pressure liquid level gauge according to any one of claims 1-14, characterized in that, The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure.

16. A liquid storage device, characterized by The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure.

17. An agricultural protection apparatus, characterized by, The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a second sensitive element for sensing the atmospheric pressure. The air pressure sensor (3) further comprises a

Images