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

Abstract

A pneumatic liquid level gauge, a liquid storage device and a plant protection apparatus. The pneumatic liquid level gauge comprises: a housing comprising a side enclosure wall, and a top cover plate and an inner partition plate which are each connected to the side enclosure wall, wherein a device mounting cavity is enclosed between the top cover plate and the inner partition plate, a ventilation chamber is formed on the side of the inner partition plate facing away from the top cover plate, the ventilation chamber is in communication with the atmosphere, and the inner partition plate is provided with a first ventilation hole enabling the device mounting cavity to be in communication with the ventilation chamber, such that the device mounting cavity can be vented to the atmosphere; and an air pressure sensor mounted in the device mounting cavity, the air pressure sensor comprising a first sensitive element for sensing the air pressure of the device mounting cavity. When raining, cleaning water splashing, and other conditions occur, even if a small amount of water splashes and enters the ventilation chamber, the part of water does not have sufficient kinetic energy to further impact upwardly and enter the device mounting cavity through the first ventilation hole, thereby avoiding the problem of internal devices being damaged by water.

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. 202411378311.1, filed on September 30, 2024, entitled "A gas pressure liquid level meter, liquid storage device and plant protection equipment" and Chinese Patent Application No. 202422413692.4, filed on September 30, 2024, entitled "A gas pressure liquid level meter, liquid storage device and plant protection equipment", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of inductive devices, 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 the pesticide liquid tank, and the air pipe thereof 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.

[0004] In order to ensure detection accuracy, the gas pressure sensor in the gas pressure liquid level meter installed on the pesticide liquid tank is generally a relative gas pressure sensor. The relative gas pressure sensor has at least two gas pressure detection points. One of the detection points is used to detect the gas pressure in the air pipe, and the other detection point is used to detect the atmospheric pressure. By obtaining the difference between the internal and external gas pressures and then converting it into a liquid level height, the problem of affecting the liquid level detection accuracy due to changes in atmospheric pressure can be avoided.

[0005] Since the gas pressure sensor needs to be in communication with the atmosphere to detect the atmospheric pressure, it cannot be installed in an absolutely sealed environment. Therefore, a gas permeable hole is usually provided on the shell of the liquid level meter to maintain communication with the atmosphere. However, since the working environment of the equipment in the field of agricultural plant protection is generally outdoor, rainwater, river water and cleaning water, etc. that are usually encountered can easily enter the liquid level meter through the gas permeable hole, thereby causing the problem that the internal gas pressure sensor and circuit board of the liquid level meter of the related technology are easily damaged by water.

[0006] If the gas pressure sensor and the related circuit board are damaged by water, the liquid level in the pesticide liquid tank cannot be accurately detected, which causes the agricultural equipment to be unable to accurately control the spraying flow of the pesticide liquid. In some places, the pesticide liquid may be excessively sprayed, causing environmental pollution. Moreover, there may be a problem that the agricultural equipment returns before the pesticide liquid is completely sprayed, resulting in waste of energy and increase of carbon emissions. In addition, the gas pressure sensor and the circuit board themselves are electronic devices, which become electronic waste after being damaged by water, posing a risk of polluting the environment. SUMMARY

[0007] The purpose of the embodiments of the present disclosure is to provide a gas pressure liquid level meter, a liquid storage device and a plant protection device, which can solve the problem that the gas pressure sensor and the circuit board are easily damaged by water in the related art.

[0008] To achieve the above purpose, the present disclosure adopts the following technical solutions:

[0009] In one aspect, a gas pressure liquid level meter is provided, comprising:

[0010] A housing includes a side wall, a top cover plate and an inner partition plate connected to the side wall respectively, a device mounting cavity is formed between the top cover plate and the inner partition plate, and an air permeation chamber is formed on the side of the inner partition plate away from the top cover plate; the air permeation chamber is in communication with the atmosphere, and the inner partition plate is provided with a first air permeation hole in communication with the device mounting cavity and the air permeation chamber, so that the device mounting cavity can ventilate with the atmosphere;

[0011] A gas pressure sensor is mounted in the device mounting cavity, and the gas pressure sensor includes a first sensitive element for sensing the gas pressure of the device mounting cavity.

[0012] Optionally, a first waterproof pipe is arranged in the air permeation chamber, one end of the first waterproof pipe is connected to the first air permeation hole, and the other end is a free end, so that the device mounting cavity ventilates with the air permeation chamber through the first waterproof pipe.

[0013] Optionally, the first waterproof pipe includes a first waterproof pipe body and an air permeation connector connected to each other, and the air permeation connector is connected to the first air permeation hole in a plug-in manner.

[0014] Optionally, a flexible pipe is connected between the first waterproof pipe body and the air permeation connector, and the inner diameter of the flexible pipe is greater than the inner diameter of the first waterproof pipe body.

[0015] Optionally, the inner partition plate is provided with a pipe clamping member on the side away from the top cover plate, and the first waterproof pipe is clamped to the pipe clamping member.

[0016] Optionally, the inner partition plate is provided with a connector protruding away from the top cover plate and used for connecting an air guide pipe, and the first waterproof pipe is arranged around the connector.

[0017] Optionally, the pipe clamping member includes an arc-shaped pipe clamping plate, the arc-shaped pipe clamping plate is arranged on the side of the connector away from the first air permeation hole, and a first pipe clamping groove capable of clamping the first waterproof pipe is formed between the arc-shaped pipe clamping plate and the connector.

[0018] Optionally, the pipe clamping member includes a clamping block arranged close to the first air permeation hole, and the clamping block is provided with a second pipe clamping groove capable of clamping the first waterproof pipe.

[0019] Optionally, the first waterproof pipe utilizes the surface tension principle of water to form a water column in the first waterproof pipe when water enters, so as to prevent external water from further invading the air pressure sensor through the first waterproof pipe.

[0020] Optionally, the inner diameter of the first waterproof pipe is 1.5-3.5 mm.

[0021] Optionally, the side wall is provided with a second air permeable hole communicating with the air permeable chamber, so that the air permeable chamber is in communication with the atmosphere.

[0022] Optionally, the shell includes a shell base and a shell upper cover, the shell base includes a first surrounding wall plate and the inner partition plate connected thereto; the shell upper cover includes a second surrounding wall plate and the top cover plate connected thereto, the shell upper cover is buckled on the shell base, the first surrounding wall plate and the second surrounding wall plate are connected to form the side wall, and the second air permeable hole is arranged on the first surrounding wall plate.

[0023] Optionally, the inner partition plate is arranged protruding to the side where the top cover plate is located relative to the first surrounding wall plate, the inner cavity of the second surrounding wall plate corresponds to the outer dimensions of the inner partition plate, and the inner partition plate is arranged embedded in the second surrounding wall plate.

[0024] Optionally, the second surrounding wall plate includes a first surrounding wall part and a second surrounding wall part connected in a stepped structure, a step part parallel to the inner partition plate is formed between the first surrounding wall part and the second surrounding wall part, a waterproof ring abutting against the step part is mounted on the inner side of the first surrounding wall part, and the inner partition plate is embedded in the first surrounding wall part and abuts against the waterproof ring.

[0025] Optionally, the step part is provided with an annular groove, and the waterproof ring is embeddedly mounted in the annular groove.

[0026] Optionally, the peripheral portion of the inner partition plate is provided with an annular flange, and the annular flange is embedded in the annular groove to abut against the waterproof ring.

[0027] Optionally, the side wall and the top cover plate are in an integrated structure, and the inner partition plate is embeddedly mounted in the side wall.

[0028] Optionally, the side wall is provided with a mounting boss away from the top cover plate, and the mounting boss is provided with a mounting hole.

[0029] Optionally, the air pressure liquid level meter is applied to a pesticide liquid tank for plant protection.

[0030] In another aspect, a liquid storage device is provided, including a liquid storage tank and the above-mentioned air pressure liquid level meter.

[0031] On another front, a plant protection device is provided, comprising a vehicle, a spraying system, and the aforementioned liquid storage device, wherein the spraying system and the liquid storage device are mounted on the vehicle, and the spraying system is used to pump out the liquid from the liquid storage device and perform atomized spraying.

[0032] The beneficial effects of this disclosure are as follows: This disclosure provides a barometric level gauge, a liquid storage device, and plant protection equipment. In the outer shell structure of the barometric level gauge, an inner partition plate, separated from the top cover plate, is provided within the side wall, forming a device mounting cavity between the top cover plate and the inner partition plate. A ventilated chamber is formed below the inner partition plate, and a first vent hole is provided in the inner partition plate, allowing the device mounting cavity to ventilate with the atmosphere through the ventilated chamber, enabling the barometric pressure sensor inside the device mounting cavity to sense atmospheric pressure. When this solution is used, in the event of rain or splashing water, even if a small amount of water splashes into the ventilated chamber, this water does not have enough kinetic energy to impact upwards and pass through the first vent hole into the device mounting cavity. Therefore, this solution can effectively protect the devices (such as circuit boards, barometric pressure sensors, etc.) installed inside the device mounting cavity from splashing water, avoiding damage to the internal devices when exposed to water.

[0033] This solution provides effective splash protection for components installed within the device mounting cavity (such as circuit boards and pressure sensors), preventing water ingress and damage to electronic components like pressure sensors and circuit boards, thus avoiding the conversion into electronic waste and environmental pollution. The pressure sensor's resistance to water ingress allows the pressure level gauge to accurately detect the liquid level, ensuring accurate pesticide application and preventing over-spraying that could lead to environmental pollution. The accurate detection of the liquid level in the pesticide tank by the pressure sensor also prevents the tank from needing to be refilled before the pesticide is completely sprayed, reducing unnecessary movement of the plant protection equipment, avoiding energy waste, and reducing carbon emissions. Attached Figure Description

[0034] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments.

[0035] Figure 1 is a structural schematic diagram of one embodiment of the pneumatic level gauge described in this disclosure;

[0036] Figure 2 is a vertical sectional view of the pneumatic level gauge shown in Figure 1;

[0037] Figure 3 is a schematic diagram of the explosion of the pneumatic level gauge shown in Figure 1 with the gas delivery pipe hidden.

[0038] Figure 4 is a vertical sectional view of the pneumatic level gauge shown in Figure 1 with the air delivery pipe concealed.

[0039] Figure 5 is an enlarged view of region A in Figure 4;

[0040] Fig. 6 is an enlarged view of area B in Fig. 4;

[0041] Fig. 7 is a structural schematic view of the top side of the shell base according to an embodiment of the present disclosure;

[0042] Fig. 8 is a structural schematic view of the bottom side of the shell base according to an embodiment of the present disclosure;

[0043] Fig. 9 is a structural schematic view of the shell base and the first waterproof pipe according to an embodiment of the present disclosure;

[0044] Fig. 10 is a structural schematic view of the shell upper cover according to an embodiment of the present disclosure;

[0045] Fig. 11 is a structural schematic view of another embodiment of the air pressure liquid level gauge according to an embodiment of the present disclosure;

[0046] Fig. 12 is a vertical sectional view of the air pressure liquid level gauge shown in Fig. 11;

[0047] Fig. 13 is a vertical sectional view of another embodiment of the shell of the air pressure liquid level gauge according to an embodiment of the present disclosure.

[0048] In the drawings:

[0049] 1, housing; 11, shell base; 111, support boss; 112, air-tight groove; 113, air-tight ring; 1131, protruding rib; 114, pipe clamping member; 1141, arc-shaped pipe clamping plate; 1142, clamping block; 12, shell upper cover; 13, side wall; 131, first wall plate; 132, second wall plate; 1321, first wall portion; 1322, second wall portion; 1323, step portion; 1324, annular groove; 1325, waterproof ring; 14, top cover plate; 15, inner partition plate; 151, annular flange; 16, device mounting cavity; 161, first sensing air chamber; 1611, sensor mounting area; 1612, bypass narrow air passage; 17, air permeation chamber; 18, first air permeation hole; 19, second air permeation hole; 2, connector; 21, mounting seat; 211, second sensing air chamber; 22, connecting head; 221, first connecting column; 222, second connecting column; 223, air passage; 23, flexible pipe; 3, air pressure sensor; 31, sensor main body; 32, sensor insertion pipe; 33, sealing ring; 4, second waterproof pipe; 5, air guide pipe; 6, first waterproof pipe; 7, main control circuit board. DETAILED DESCRIPTION

[0050] 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 further described in 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.

[0051] In the description of the present disclosure, unless explicitly defined and limited otherwise, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0052] In the present disclosure, unless explicitly defined and limited otherwise, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0053] In the field of plant protection, a gas pressure liquid level meter is usually integrated in the pesticide automatic spraying equipment. The main body of the gas pressure liquid level meter is generally installed on the top of the pesticide tank, and a gas pressure sensor is integrated inside, and a ventilation pipe communicating with the gas pressure sensor is arranged, which extends to the bottom of the pesticide tank. The gas pressure liquid level meter can automatically monitor the liquid level in the pesticide tank in real time.

[0054] In order to guarantee the detection accuracy, the air pressure sensor in the air pressure liquid level meter installed on the liquid tank in the related art is generally a relative air pressure sensor. The relative air pressure sensor has at least two air pressure detection points. One of the detection points is used for detecting the air pressure in the air pipe, and the other detection point is used for detecting the atmospheric pressure. By obtaining the difference between the internal and external air pressures and then converting the difference into the liquid level height, the problem that the liquid level detection accuracy is affected by the change of the atmospheric pressure can be avoided. Since the air pressure sensor needs to be in communication with the atmosphere to detect the atmospheric pressure, the air pressure sensor cannot be installed in an absolutely sealed environment. Generally, a gas permeation hole is arranged on the shell of the liquid level meter to keep the atmosphere in communication. 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 and the like contacted in daily life can easily invade the inside of the liquid level meter through the gas permeation hole, thereby causing the problem that the internal air pressure sensor and the circuit board in the liquid level meter in the related art are easily damaged by water.

[0055] In order to overcome the above technical problems, referring to FIG. 4 or FIG. 13, the embodiment provides another air pressure liquid level meter which can effectively prevent the problem that external splashing water such as rainwater and cleaning water invades the inside of the air pressure liquid level meter and causes the internal electronic device to be damaged by water.

[0056] Referring to FIG. 1, FIG. 4 and FIG. 7, the air pressure liquid level meter of the embodiment comprises a shell 1 and an air pressure sensor. The shell 1 comprises a side wall 13, a top cover plate 14 and an inner partition plate 15 connected with the side wall 13 respectively. A device mounting cavity 16 is formed between the top cover plate 14 and the inner partition plate 15. 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. The inner partition plate 15 is provided with a first gas permeation hole 18 which communicates the device mounting cavity 16 and the air permeation chamber 17, so that the device mounting cavity 16 can be ventilated with the atmosphere. The air pressure sensor is installed in the device mounting cavity 16. The air pressure sensor comprises a first sensitive element for sensing the air pressure of the device mounting cavity 16.

[0057] 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. The air pressure sensor and the required main control circuit board 7 and the like can be installed in the device mounting cavity 16, which is reliably protected by the shell 1 to realize the functions of waterproofing, dustproofing and the like.

[0058] The first gas 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 to be in communication with the atmosphere, thereby realizing the purpose that the device mounting cavity 16 is in communication with the atmosphere, so that the air pressure sensor in the device mounting cavity 16 can normally sense the atmospheric pressure.

[0059] The air pressure liquid level meter of the embodiment can be applied in various scenes requiring liquid level detection. Taking the application of the air pressure liquid level meter of the embodiment to a plant protection liquid tank as an example, during installation, the shell 1 is fixed on the top of the liquid tank, that is, the bottom edge of the side wall 13 needs to contact the liquid tank for installation. At this time, the side wall 13, the inner partition plate 15 and the liquid tank 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 can be arranged on the side wall 13, or a hole or groove communicating with the air permeation chamber 17 can be arranged on the liquid tank.

[0060] It can be understood that after the air pressure liquid level meter of the embodiment is installed, the inner partition plate 15 is located above the air permeation chamber 17, that is, the first air permeation hole 18 arranged on the inner partition plate 15 is also located above the air permeation chamber 17. When it rains, washes or the like, even if the splashing water enters the air permeation chamber 17 through the hole, groove or the like on the side wall 13 or the liquid tank communicating with the air permeation chamber 17, it is difficult for the water to splash upward in the air permeation chamber 17 and pass through the first air permeation hole 18 into the device mounting cavity 16.

[0061] In summary, based on the air pressure liquid level meter of the embodiment, the inner partition plate 15 is arranged in the side wall 13 and separated from the top cover plate 14, so that the device mounting cavity 16 is formed between the top cover plate 14 and the inner partition plate 15, the air permeation chamber 17 is formed below the inner partition plate 15, and the first air permeation hole 18 is arranged on the inner partition plate 15, so that the device mounting cavity 16 can be ventilated with the atmosphere through the air permeation chamber 17, and the air pressure sensor in the device mounting cavity 16 can sense the atmospheric pressure. When the air pressure liquid level meter of the present scheme is used, even if a small amount of water splashes into the air permeation chamber 17 when it rains, washes or the like, the water does not have enough kinetic energy to splash upward and pass through the first air permeation hole 18 into the device mounting cavity 16. Therefore, the present scheme can provide effective protection against splashing water for the devices (such as circuit boards, air pressure sensors 3, etc.) installed in the device mounting cavity 16, avoiding the problem of water damage to the internal devices.

[0062] The air pressure liquid level meter 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.

[0063] The air pressure liquid level meter of the embodiment has more obvious advantages when applied in the scene of an agricultural plant protection liquid tank. Because the plant protection liquid tank is used outdoors, it is difficult to avoid rain. Moreover, the user often needs to clean the air pressure liquid level meter after use. The waterproof structure of the present embodiment can meet the needs of the plant protection liquid tank in dealing with various splashing water scenes.

[0064] In an embodiment, in combination with FIG. 3, FIG. 4 and FIG. 9, the air vent chamber 17 is provided with a first waterproof pipe 6, one end of the first waterproof pipe 6 is connected to the first air vent hole 18, and the other end is a free end, so that the device mounting cavity 16 is ventilated with the air vent chamber 17 through the first waterproof pipe 6.

[0065] Wherein, under normal conditions, the first waterproof pipe 6 can communicate the device mounting cavity 16 with the air vent chamber 17, realizing the communication of the device mounting cavity 16 with the atmosphere. When encountering water, effective waterproof can be achieved through the first waterproof pipe 6.

[0066] In an embodiment, the waterproof principle of the first waterproof pipe 6 is similar to that of a capillary tube. When the external liquid enters the first waterproof pipe 6 through the end of the first waterproof pipe 6 away from the device mounting cavity 16, the liquid is easy to form a water column in the first waterproof pipe 6 under the action of liquid tension. The water column can isolate the space between the device mounting cavity 16 and the first waterproof pipe 6 from the outside, which is equivalent to forming a blockage, preventing the air between the air pressure sensor 3 and the first waterproof pipe 6 from being discharged. When the pressure of the external liquid balances with the air pressure in the first waterproof pipe 6, the liquid cannot continue to enter, so as to achieve the purpose of waterproofing the air pressure sensor 3.

[0067] It should be noted that the purpose of providing the first waterproof pipe 6 in this embodiment is to provide an insurance waterproof function. In the conventional use process, the external splashing water cannot enter the first waterproof pipe 6. When encountering water immersion, based on the provision of the first waterproof pipe 6, the external water can be prevented from entering the device mounting cavity 16 through the first waterproof pipe 6, realizing the function of providing normal waterproof even in the water immersion condition. The air pressure liquid level meter with the first waterproof pipe 6 has a particular advantage in the automatic spraying equipment carried by the unmanned aerial vehicle. Because the air pressure liquid level meter of the present scheme can realize effective waterproof function even if the entire air pressure liquid level meter is immersed in water, when the unmanned aerial vehicle carrying the automatic spraying equipment performs plant protection work, and the unmanned aerial vehicle and the chemical tank fall into water due to accidental falling when the unmanned aerial vehicle flies over the water surface, the air pressure liquid level meter can also avoid water entering the inside.

[0068] In addition, when the first waterproof pipe 6 of the air pressure liquid level meter is blocked by water, the water in the first waterproof pipe 6 can be shaken out by shaking or knocking, etc., so as to restore the use.

[0069] 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 at the air permeable opening of the shell, 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 film in the waterproof air permeable valve sticks to water, the entire waterproof air permeable valve needs to be disassembled, the air permeable film is dried and then reassembled, and the drainage process is relatively complex. More importantly, since the air permeable film inside the waterproof air permeable valve cannot be directly observed outside, the user often cannot judge whether the air permeable film sticks to 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 inventor creatively designed the air permeable waterproof structure with the first waterproof pipe 6 of the present embodiment, and the first waterproof pipe 6 is a transparent pipe. Before use, the user can directly observe whether water enters the first waterproof pipe 6, and when water is found, the water in the first waterproof pipe 6 can be drained by swinging or flicking the first waterproof pipe 6. Compared with the waterproofing method using the waterproof air permeable valve, the first waterproof pipe 6 of the present solution is more user-friendly in operation.

[0070] In an embodiment, the first waterproof pipe 6 includes a first waterproof pipe body and an air permeable connector connected to each other, and the air permeable connector is connected to the first air permeable hole 18 in a plug-in manner.

[0071] The first waterproof pipe 6 is divided into a first waterproof pipe body and an air permeable connector, realizing a modular design. This design makes it easier to handle different components during production, installation and maintenance, improving the overall work efficiency and convenience. The air permeable connector is connected to the first air permeable hole 18 in a plug-in manner, which 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, reducing maintenance costs.

[0072] In an embodiment, as shown in FIG. 2, a flexible pipe 23 is connected between the first waterproof pipe body and the air permeable connector, and the inner diameter of the flexible pipe 23 is greater than the inner diameter of the first waterproof pipe body.

[0073] The flexible pipe 23 is provided to give the first waterproof pipe 6 unique maintenance convenience. Specifically, when the first waterproof pipe 6 is filled with water, due to the presence of the flexible pipe 23, the user can directly squeeze the flexible pipe 23 to use air pressure to squeeze out the water column in the first waterproof pipe 6, thereby quickly restoring the normal use function of the air pressure liquid level meter. This design greatly simplifies the maintenance process and improves the operation convenience of the user.

[0074] In an embodiment, in combination with FIG. 8 and FIG. 9, the inner partition plate 15 is provided with a clamping pipe member 114 on the side facing away from the top cover plate 14, and the first waterproof pipe 6 is clamped to the clamping pipe member 114.

[0075] The design of the clamping pipe member 114 enables the first 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 first waterproof pipe 6 during long-term use, preventing water or air leakage problems caused by unstable connection.

[0076] 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 first waterproof pipe 6 is wound around the connector 2.

[0077] Specifically, the air pressure sensor 3 of the present embodiment adopts a relative air pressure sensor 3, which at least has a first sensitive element and a second sensitive element. The first sensitive element is used to sense the atmospheric pressure, and the second 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 first sensitive element and the second 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 second 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 first sensitive element is located on the side of the device mounting cavity 16, and the second sensitive element is directed towards the second sensing gas chamber 211. After the air pressure sensor 3 is installed, the second 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 first sensitive element can sense the atmospheric pressure, and the second sensitive element can sense the air pressure on the liquid side. Referring to FIG. 5, in order to effectively isolate the second sensing gas chamber 211 from the device mounting cavity 16, the air pressure sensor 3 includes a sensor main body 31 and a sensor insertion pipe 32. The first sensitive element is located on the side of the sensor main body 31, and the second sensitive element is aligned with the lumen of the sensor insertion pipe 32. A sealing ring 33 is provided at the position of the second 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 second sensing gas chamber 211 can be effectively isolated from the device mounting cavity 16 based on the installation of the air pressure sensor 3 and the sealing ring 33.

[0078] When the bubble water accident occurs, the external water enters into the first waterproof pipe 6 and forms a water column in the first waterproof pipe 6. The deeper the bubble water 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 first waterproof pipe 6 determines the waterproof capability of the device mounting cavity 16. The longer the length of the water column that can be formed 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. The first waterproof pipe 6 is arranged in a spiral shape around the connector 2 in the scheme, so that the first waterproof pipe 6 can be arranged in the limited space in the air chamber 17 effectively. Importantly, the spiral-shaped first waterproof pipe 6 has the advantage of long length in the case of occupying small space, so that it is beneficial to obtain the first waterproof pipe 6 with a longer length and to obtain better anti-deep water waterproofing capability.

[0079] In an embodiment, in combination with FIG. 8, the clamping pipe member 114 includes an arc-shaped clamping pipe plate 1141 arranged on the side of the connector 2 away from the first air vent hole 18, and a first clamping pipe groove capable of clamping the first waterproof pipe 6 is formed between the arc-shaped clamping pipe plate 1141 and the connector 2.

[0080] Since the first waterproof pipe 6 is usually cylindrical or tubular in structure, the design of the arc-shaped clamping pipe plate 1141 can better adapt to the shape of the first waterproof pipe 6, and the arc-shaped clamping pipe plate 1141 can be tightly fitted therewith to provide uniform clamping force and reduce the problem of preventing air passage caused by the bending of the middle part of the first waterproof pipe 6. Moreover, the arc-shaped clamping pipe plate 1141 can use the outer wall of the connector 2 to fix the first waterproof pipe 6, thereby achieving the purpose of simplifying the structure of the clamping pipe member 114.

[0081] In an embodiment, the clamping pipe member 114 includes a clamping block 1142 arranged close to the first air vent hole 18, and the clamping block 1142 is provided with a second clamping pipe groove capable of clamping the first waterproof pipe 6.

[0082] Specifically, at the position close to the first air vent hole 18, the first waterproof pipe 6 needs to be avoided, so the clamping block 1142 occupying smaller space is arranged to provide fixation, that is, to meet the demand of fixing the first waterproof pipe 6 and to avoid the problem of mutual extrusion caused by the waterproof pipes themselves.

[0083] In an embodiment, the first waterproof pipe 6 uses the principle of surface tension of water to form a water column in the first waterproof pipe 6 when water enters to prevent the further intrusion of external water through the first waterproof pipe 6 into the air pressure sensor 3.

[0084] Specifically, the first waterproof pipe 6 realizes the waterproof function by using the principle of liquid surface tension. Only the inner diameter of the first waterproof pipe 6 needs to be small enough to form a water column when water enters, and the first waterproof pipe 6 of this structure has the advantages of simple structure and low cost.

[0085] In an embodiment, the inner diameter of the first waterproof pipe 6 is 1.5-3.5mm.

[0086] Setting the inner diameter of the first waterproof pipe 6 to 1.5-3.5mm can meet the normal ventilation requirements, and at the same time realize the function of forming a water column in the first waterproof pipe 6 by using the liquid surface tension to realize waterproof.

[0087] Further preferably, the inner diameter of the first waterproof pipe 6 is 2.5-2.7mm, which is a small size that can provide stable ventilation function and ensure the formation of a stable water column when water enters.

[0088] In an embodiment, referring to FIGS. 7-8, the side wall 13 is provided with a second air hole 19 communicating with the air chamber 17, so that the air chamber 17 is in communication with the atmosphere.

[0089] By setting the second air hole 19 in the side wall 13 to realize ventilation, the liquid tank to which it is installed does not need to start a corresponding hole or groove position. The air pressure liquid level meter of this embodiment can be directly applied to the related technical liquid tank and normally used without any improvement of the liquid tank.

[0090] Regarding the setting form of the shell 1, in an embodiment, in combination with FIGS. 3, 4 and 6, the shell 1 includes a shell base 11 and a shell cover 12, the shell base 11 includes a first surrounding wall plate 131 and the inner partition plate 15 connected together; the shell cover 12 includes a second surrounding wall plate 132 and the top cover plate 14 connected together, the shell cover 12 is buckled on the shell base 11, the first surrounding wall plate 131 and the second surrounding wall plate 132 are connected to form the side wall 13, and the second air hole 19 is arranged on the first surrounding wall plate 131.

[0091] The shell 1 is divided into two modules of the shell base 11 and the shell 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 cover 12 is buckled on the shell base 11, and the tight connection between the two is ensured by appropriate fixing methods (such as buckles, screws, etc.). This assembly method is not only simple and fast, but also can ensure the sealing and stability of the shell 1.

[0092] 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 first surrounding wall plate 131, and the inner cavity of the second surrounding wall plate 132 corresponds to the size of the inner partition plate 15, and the inner partition plate 15 is embedded in the second surrounding wall plate 132.

[0093] Since the inner partition plate 15 is embedded in the second surrounding wall plate 132, when the shell upper cover 12 is buckled on the shell base 11, the second surrounding wall plate 132 will automatically align with the first surrounding wall plate 131 and tightly 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 first surrounding wall plate 131 and the embedding of the inner partition plate 15 in the second 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 second surrounding wall plate 132 and the contact between the inner partition plate 15 and the first surrounding wall plate 131, a continuous sealing barrier is formed between the 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 gauge.

[0094] In one embodiment, as shown in FIG. 6, the second surrounding wall plate 132 includes a first surrounding wall part 1321 and a second surrounding wall part 1322 connected in a stepped structure, and a step part 1323 parallel to the inner partition plate 15 is formed between the first surrounding wall part 1321 and the second surrounding wall part 1322. A waterproof ring 1325 abutting against the step part 1323 is installed on the inner side of the first surrounding wall part 1321, and the inner partition plate 15 is embedded in the first surrounding wall part 1321 and abuts against the waterproof ring 1325.

[0095] The waterproof ring 1325 is installed on the inner side of the first surrounding wall part 1321 and tightly abuts against the step part 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 first surrounding wall part 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.

[0096] In one embodiment, the step part 1323 is provided with an annular groove 1324, and the waterproof ring 1325 is embeddedly installed in the annular groove 1324.

[0097] As shown in FIG. 10, 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 shaped and sized to match the waterproof ring 1325, ensuring that the waterproof ring 1325 can be stably embedded therein. 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.

[0098] 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.

[0099] 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. This embedded design forms a continuous and close sealing structure between the inner partition plate 15, the waterproof ring 1325, and the stepped portion 1323, further enhancing the sealing effect of the waterproof ring 1325 and ensuring the dryness and cleanliness of the inside of the shell 1.

[0100] Regarding the arrangement form of the shell 1, in another embodiment, referring to FIG. 13, the side wall 13 and the top cover plate 14 are in an integrated structure, and the inner partition plate 15 is embeddedly installed in the side wall 13.

[0101] This structure can also achieve the structure of forming a device mounting cavity 16 and a gas permeation chamber 17 above and below the inner partition plate 15, respectively, to achieve the waterproof purpose.

[0102] 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.

[0103] 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 by locking the bolt passing through the mounting hole to the threaded hole, reliable fixation of the air pressure liquid level meter can be achieved.

[0104] On the other hand, a liquid storage device is provided, which includes a liquid storage tank and the air pressure liquid level meter described above. The shell 1 of the air pressure liquid level meter is installed on the top of the liquid storage tank, and the air guide pipe 5 of the air pressure liquid level meter extends to the bottom of the liquid storage tank away from the shell 1.

[0105] Similarly, the air pressure liquid level meter in the liquid storage device of the embodiment has the advantage of good waterproof capability.

[0106] 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.

[0107] The carrier can be an unmanned vehicle, an unmanned aerial vehicle, a manually driven vehicle, or the like.

[0108] The spraying system includes a pumping device and an atomizer, and the like. The pipelines at both ends of the pumping device are connected to the liquid storage tank and the atomizer, respectively. The pumping device is used to pump the pesticide in the liquid storage tank, and the pesticide is uniformly sprayed on the crops after being atomized by the atomizer. Based on the carrying of the carrier, mobile spraying operation can be realized.

[0109] Based on the liquid storage device of the present embodiment, the air pressure liquid level meter in the plant protection device of the present embodiment has the advantages of strong waterproof capability and long service life.

[0110] Under normal circumstances, since the air 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 air pressure liquid level meter through the breather pipe. In order to meet the normal ventilation requirements, the air pressure sensor 3 cannot be sealed from the breather pipe. Therefore, the air pressure sensor 3 of the related art is generally exposed to the air connected to the breather pipe. This leads to the problem that when the pesticide tank is accidentally tilted or even inverted, the pesticide is easy to flow back and contact the air pressure sensor 3 through the breather pipe, thereby causing the air pressure sensor 3 to be damaged by water. Therefore, in the air pressure liquid level meter of the related art, there is a risk of water entering the side of the air pressure sensor 3 connected to the breather pipe.

[0111] In order to overcome the above technical problems, the present embodiment also provides another air pressure liquid level meter, which can meet the requirement of the air pressure sensor 3 sensing the gas pressure on the liquid side, and also can provide reliable waterproof function in emergency to provide reliable protection for the air pressure sensor 3. It should be noted that the air pressure liquid level meter of the present embodiment can be combined with the design points of the air pressure liquid level meter of any one or more of the above-mentioned embodiments.

[0112] As shown in FIG. 2, the air pressure liquid level meter of the present embodiment at least includes an air pressure sensor 3, a second waterproof pipe 4, and a gas guide pipe 5. The second waterproof pipe 4 is in communication with the air pressure sensor 3. The inner diameter of the gas guide pipe 5 is greater than that of the second waterproof pipe 4. One end of the gas guide pipe 5 is in communication with the air pressure sensor 3 through the second waterproof pipe 4, and the other end is used to extend into the liquid to sense the water pressure.

[0113] The air pressure liquid level meter of the embodiment utilizes the air pressure detection principle to realize the function of detecting the liquid level height. In specific application, the air guide pipe 5 extends to the liquid at the end far from the second waterproof pipe 4, the air pressure sensor 3, the second waterproof pipe 4, the air guide pipe 5 and the liquid form a closed cavity, the liquid exerts pressure on the air in the cavity, the air pressure sensor 3 detects the air pressure of the air, the higher the liquid level, the greater the pressure exerted by the liquid on the air in the cavity, and the higher the air pressure value detected by the air pressure sensor 3, that is, the air pressure value detected by the air pressure sensor 3 can be converted into the liquid level height.

[0114] The waterproof principle of the second waterproof pipe 4 is similar to that of a capillary tube. When the external liquid enters the second waterproof pipe 4 through the end far from the air pressure sensor 3, the liquid is easy to form a water column in the second waterproof pipe 4 under the action of the liquid tension, which can isolate the space between the air pressure sensor 3 and the second waterproof pipe 4 from the outside, equivalent to forming a blockage to prevent the air between the air pressure sensor 3 and the second waterproof pipe 4 from being discharged, and when the pressure of the external liquid balances with the air pressure in the second waterproof pipe 4, the liquid cannot continue to enter, thereby achieving the purpose of waterproofing the air pressure sensor 3.

[0115] It should be noted that the second waterproof pipe 4 provided in the present disclosure does not extend into the liquid at the end connected to the air guide pipe 5 in the normal use state, because the waterproof principle of the second waterproof pipe 4 is to utilize the tension of the liquid itself. When the liquid enters the second waterproof pipe 4, it is easy to form a water column in the second waterproof pipe 4, which is difficult to be removed freely under the action of its own gravity, and the height of the water column is also difficult to change, which leads to that the air pressure in the second waterproof pipe 4 cannot accurately reflect the pressure exerted by the liquid, that is, the air pressure value sensed by the air pressure sensor 3 cannot sensitively reflect the liquid level height, directly leading to the problem of invalidation of the liquid level meter. Therefore, the air guide pipe 5 plays a crucial role as an intermediate bridge connecting the second waterproof pipe 4 and the liquid. The inner diameter of the air guide pipe 5 is relatively large, and it is also difficult to form a water column in the air guide pipe 5 under the action of the liquid tension. When the liquid level changes, the liquid level in the air guide pipe 5 will also sensitively follow the change, so that the air pressure in the air guide pipe 5 can accurately reflect the liquid pressure. The second waterproof pipe 4 is connected to the air guide pipe 5, so the air pressure in the second waterproof pipe 4 can also accurately reflect the liquid pressure. In summary, on the basis of the second waterproof pipe 4 provided in the present embodiment for air permeation and waterproofing of the air pressure sensor 3, the air guide pipe 5 is further provided to extend into the liquid, so that the second waterproof pipe 4 will not be in contact with water in the normal use state, thereby avoiding the problem of affecting the liquid level detection accuracy after the second waterproof pipe 4 is filled with water.

[0116] In specific applications, the air pressure sensor 3 used in the air pressure liquid level meter can be an absolute air pressure sensor or a relative air pressure sensor according to the use requirements. When the absolute air pressure sensor 3 is adopted, only one sensitive element is arranged on the absolute air pressure sensor 3, and the sensitive element can sense the air pressure in the second waterproof pipe 4. When the relative air pressure sensor is adopted, two sensitive elements are arranged, one of which can sense the air pressure in the second waterproof pipe 4, and the other can sense the atmospheric pressure. The air pressure difference detected by the two sensitive elements can accurately reflect the actual liquid level height, avoiding the problem that the change of atmospheric pressure affects the liquid level detection.

[0117] In summary, based on the air pressure liquid level meter of the embodiment, the second waterproof pipe 4 is arranged to communicate the air guide pipe 5 and the air pressure sensor 3. Under normal circumstances, the air guide pipe 5 and the air pressure sensor 3 can be communicated through the second waterproof pipe 4, so that the air pressure sensor 3 can normally sense the air pressure of the air guide pipe 5, and the function of liquid level detection is realized. The waterproof principle of the second waterproof pipe 4 is similar to that of a capillary tube. When the external liquid enters the air pressure sensor 3 through the end of the second waterproof pipe 4 away from the air pressure sensor 3, the liquid is easy to form a water column in the second waterproof pipe 4 under the action of liquid tension. The water column can isolate the space between the air pressure sensor 3 and the second waterproof pipe 4 from the outside, which is equivalent to forming a blockage to prevent the air between the air pressure sensor 3 and the second waterproof pipe 4 from being discharged. When the pressure of the external liquid balances with the air pressure in the second waterproof pipe 4, the liquid cannot continue to enter, so the purpose of waterproofing the air pressure sensor 3 is achieved.

[0118] The air pressure liquid level meter 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.

[0119] The air pressure liquid level meter 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 leads to the problem that the liquid is polluted and flows into the air pressure sensor 3, and the liquid itself has a certain corrosiveness, which is more likely to cause damage to the air pressure sensor 3. The design of the second waterproof pipe 4 of the present solution 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 meter of the present solution has more obvious advantages when applied in the scene of agricultural plant protection liquid tanks.

[0120] 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 the function of air permeability and water resistance. 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 during use, thereby causing a certain burden to the user. After repeated experiments and research, the inventor creatively designed the air-permeable waterproof structure with the second waterproof pipe 4 of the present embodiment, and the second waterproof pipe 4 is a transparent pipe. Before use, the user can directly observe whether water has entered the second waterproof pipe 4, and when water is found, the water in the second waterproof pipe 4 can be drained by shaking or flicking the second waterproof pipe 4. Compared with the waterproof mode using the waterproof air-permeable valve, the second waterproof pipe 4 of the present solution is more user-friendly in operation.

[0121] In an embodiment, referring to FIGS. 2 and 4, the air pressure sensor 3 further comprises a connector 2, and the connector 2 is internally provided with a second sensing air chamber 211; the air pressure sensor 3 comprises a second sensitive element for sensing the air pressure inside the second sensing air chamber 211, and the second waterproof pipe 4 is connected to the connector 2 and communicates with the second sensing air chamber 211.

[0122] Specifically, the connector 2 can provide mounting support for the air pressure sensor 3, and realize the function of indirect connection between the air pressure sensor 3 and the second waterproof pipe 4. Importantly, the connector 2 can provide a closed second sensing air chamber 211 inside, which is isolated from the outside and communicates with the second waterproof pipe 4 and the air guide pipe 5. The air pressure in the second air pressure sensor 3 can accurately reflect the pressure applied by the liquid, and realize the function of accurately detecting the liquid level. In summary, the connector 2 provides a reliable bridge for the connection between the air pressure sensor 3 and the second waterproof pipe 4, and effectively guarantees the air tightness of the connection structure.

[0123] In specific implementation, the air pressure sensor 3 can be completely or partially installed into the second 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 second sensing air chamber 211), as long as the second sensitive element thereon can be aligned towards the second sensing air chamber 211.

[0124] In another embodiment, the air pressure sensor 3 comprises a sensor body 31 and a sensor cannula 32, and the second sensitive element is aligned with a lumen of the sensor cannula 32; the end of the second waterproof tube 4 is directly sleeved to the sensor cannula 32, so that the second sensitive element can accurately sense the air pressure in the second waterproof tube 4.

[0125] With regard to the connection arrangement of the second waterproof tube 4 and the air guide tube 5, in one embodiment, referring to FIG. 2 or FIG. 12, the connector 2 comprises a connecting head 22, which comprises a second connecting column 222 and a first connecting column 221 connected to each other, and a ventilation channel 223 is arranged in the connecting head 22 and penetrates through the second connecting column 222 and the first connecting column 221, and the ventilation channel 223 communicates with the second sensing air chamber 211; the second waterproof tube 4 is connected to the first connecting column 221, and the air guide tube 5 is sleeved outside the second waterproof tube 4 and connected to the second connecting column 222.

[0126] In this embodiment, the second connecting column 222 and the first connecting column 221 are arranged in the connecting head 22 and are used to connect the air guide tube 5 and the second waterproof tube 4, respectively, so the diameter of the second connecting column 222 needs to be arranged correspondingly to the air guide tube 5, and the diameter of the first connecting column 221 needs to be arranged correspondingly to the second waterproof tube 4. The key of this structure is to realize the sleeving structure of the air guide tube 5 and the second waterproof tube 4, that is, the second waterproof tube 4 is inserted into the air guide tube 5. When the air pressure liquid level meter is inverted, the liquid will first fill the space between the second waterproof tube 4 and the air guide tube 5, and only when the height of the liquid exceeds the height of the free end of the second waterproof tube 4, the liquid can enter the second waterproof tube 4. This is extremely obvious in the application of the plant protection liquid tank. Specifically, the liquid in the used liquid tank cannot be completely emptied, and a small amount of liquid is usually left in the liquid tank. Moreover, the used liquid tank is light in weight and is prone to tilting and inverting. When it is tilted or inverted, a small amount of liquid can easily enter through the free end of the air guide tube 5 and be stored in the space between the second waterproof tube 4 and the air guide tube 5. In this way, the problem of water entering the second waterproof tube 4 can be avoided, and the user does not need to remove the second waterproof tube 4 for drainage in the later use, thereby facilitating the use of the user.

[0127] In one embodiment, the second waterproof tube 4 is sleeved on the first connecting column 221; and / or the air guide tube 5 is sleeved on the second connecting column 222.

[0128] The sleeving connection structure further enhances the sealing and stability of the connection between the tube and the connector 2.

[0129] Preferably, the second connecting column 222 and the first connecting column 221 are both arranged as a pagoda connecting head 22 to improve the reliability of the connection.

[0130] 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 second 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.

[0131] The mounting base 21 can be used to stably mount the air pressure sensor 3. The second sensing air chamber 211 is arranged in the mounting base 21, and after the air pressure sensor 3 is mounted, the second sensing element thereon can be aligned towards the second sensing air chamber 211.

[0132] 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.

[0133] By designing the mounting base 21 and the connecting head 22 in an integrated structure, the overall structural strength of the connector 2 is significantly improved, and this design can resist greater external force and vibration, and ensure the stability and reliability of the connector 2 under harsh working conditions. The integrated structure design simplifies the manufacturing process of the connector 2, and in the manufacturing process, the machining and assembly of the mounting base 21 and the connecting head 22 can be completed at one time, thereby reducing the production cost and improving the production efficiency. Since there is no additional connection gap between the mounting base 21 and the connecting head 22, the risk of leakage caused by poor connection is reduced, and this design helps to ensure the air tightness inside the connector 2 and ensure the accuracy of air pressure transmission.

[0134] 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 second sensing air chamber 211 is arranged in the mounting base 21, and the two ends of the flexible pipe 23 are connected with the mounting base 21 and the connecting head 22 respectively to conduct the second sensing air chamber 211 and the air passage 223.

[0135] 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 second sensing air chamber 211 and the air passage 223, but also endows the connector 2 with unique convenience in maintenance.

[0136] The mounting base 21 can be used to mount the air pressure sensor 3 stably. The second sensing air chamber 211 is arranged on the mounting base 21, and the second sensing element on the air pressure sensor 3 can be aligned to face the second sensing air chamber 211 after the air pressure sensor 3 is mounted. The two ends of the flexible pipe 23 are connected to the mounting base 21 and the connector 22 respectively, ensuring smooth conduction between the second sensing air chamber 211 and the air passage 223, which enables the air pressure to pass through the air guide pipe 5, the connector 22, and the flexible pipe 23 to the second sensing air chamber 211 without obstruction, and be accurately sensed by the air pressure sensor 3. When the second waterproof pipe 4 is filled with water, the conventional connector 2 needs to be disassembled for drainage, while in this embodiment, due to the presence of the flexible pipe 23, the user can directly squeeze the flexible pipe 23 to use the air pressure to squeeze out the water column in the second waterproof pipe 4, thereby quickly restoring the normal use function of the connector 2. This design greatly simplifies the maintenance process and improves the user's operation convenience.

[0137] 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.

[0138] 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.

[0139] In an embodiment, the second waterproof pipe 4 uses the principle of water surface tension to form a water column in the second waterproof pipe 4 when water enters to prevent external water from further invading the air pressure sensor 3 through the second waterproof pipe 4.

[0140] Specifically, the second waterproof pipe 4 uses the principle of liquid surface tension to achieve waterproof function, which only needs to set the inner diameter of the second waterproof pipe 4 small enough to form a water column when water enters. This structure of the second waterproof pipe 4 has the advantages of simple structure and low cost.

[0141] In an embodiment, the inner diameter of the second waterproof pipe 4 is 1.5-3.5mm.

[0142] Setting the inner diameter of the second waterproof pipe 4 to 1.5-3.5mm can meet the normal air permeability requirement, and at the same time, can form a water column in the second waterproof pipe 4 by using the liquid surface tension to achieve the waterproof function.

[0143] Further preferably, the inner diameter of the second waterproof pipe 4 is 2.5-2.7mm, which is small enough to ensure stable air permeability and to form a stable water column when water enters.

[0144] In an embodiment, the inner diameter of the air guide pipe 5 is 5-12mm.

[0145] 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 measurement accuracy and real-time performance.

[0146] In an embodiment, in combination with FIGS. 4-5, the air pressure sensor 3 includes a sensor body 31, one side of the sensor body 31 is provided with a sensor cannula 32; the second sensitive element is arranged in the sensor cannula 32; the connector 2 is provided with a sensing connection hole communicating with the second sensing air chamber 211, and the sensor cannula 32 is inserted into the sensing connection hole, so that the second sensitive element can sense the internal air pressure of the second sensing air chamber 211.

[0147] The specially designed sensing connection hole on the connector 2 is a bridge connecting the second sensing air chamber 211 and the sensor cannula 32. The sensor cannula 32 is connected to the sensing connection hole in a plug-in manner. This connection method is not only simple and fast, but also can ensure the sealing and reliability of the connection. After plugging, the second sensitive element can directly face the inside of the second sensing air chamber 211 and sense the air pressure change in the second sensing air chamber 211.

[0148] 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.

[0149] 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 second sensing air chamber 211, so that the air pressure in the second sensing air chamber 211 can accurately reflect the liquid pressure, thereby ensuring the accuracy of the liquid level detection.

[0150] In an embodiment, the air pressure sensor 3 further includes a first sensitive element for sensing the atmospheric pressure.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] Similarly, the air pressure liquid level meter in the liquid storage device of the embodiment has the advantage of good waterproof capability.

[0157] 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.

[0158] The carrier can be an unmanned vehicle, an unmanned aerial vehicle, a manually driven vehicle, etc.

[0159] 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.

[0160] 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.

[0161] 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 is generally a relative air pressure sensor. The relative air pressure sensor 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 liquid level meter through the gas permeable hole, which in turn causes the problem that the internal air pressure sensor 3 and the circuit board of the liquid level meter of the related technology are easily damaged by water.

[0162] To overcome the above technical problems, with reference to FIG. 1, FIG. 4 and FIG. 5, the embodiment also provides another air pressure liquid level meter which can effectively prevent the problem that the external splashing water such as rainwater, cleaning water and the like enters the air pressure liquid level meter and causes the internal electronic device to be damaged by water. It should be noted that the air pressure liquid level meter of the embodiment can be combined with the design points of the air pressure liquid level meter of any one or more of the above embodiments.

[0163] The air pressure liquid level meter of the embodiment comprises a shell 1, an air pressure sensor 3 and a first waterproof pipe 6. The shell 1 is internally provided with a device mounting cavity 16, and the device mounting cavity 16 is internally provided with a separate first sensing air chamber 161. The shell 1 is also provided with a first air permeable hole 18 which communicates with the first 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 first sensing air chamber 161. One end of the first waterproof pipe 6 is connected to the first air permeable hole 18, and the other end is in communication with the atmospheric pressure. The first sensing air chamber 161 is communicated with the atmosphere through the first waterproof pipe 6.

[0164] The device mounting cavity 16 is used to mount the air pressure sensor 3, the main control circuit board 7 and the like, and the shell 1 can provide sufficient protection. The first sensing air chamber 161 is a part separated from the device mounting cavity 16, and its volume is necessarily smaller than the volume of the entire device mounting cavity 16. The air pressure sensor 3 is provided with a first sensitive element for sensing the air pressure in the first sensing air chamber 161. When the air pressure sensor 3 is mounted, it can be mounted into the first sensing air chamber 161 or outside the first sensing air chamber 161, as long as the first sensitive element on the air pressure sensor 3 can be aligned and directed towards the first sensing air chamber 161.

[0165] The first waterproof pipe 6 can communicate the first sensing air chamber 161 with the outside world under normal conditions, so as to realize the communication between the first sensing air chamber 161 and the atmosphere. When water is encountered, effective waterproofing can be realized through the first waterproof pipe 6. The waterproof principle of the first waterproof pipe 6 is similar to that of a capillary tube. When the external liquid enters the first waterproof pipe 6 through the end of the first waterproof pipe 6 far away from the first sensing air chamber 161, the liquid is easy to form a water column in the first waterproof pipe 6 under the action of liquid tension. The water column can isolate the space between the device mounting cavity 16 and the first waterproof pipe 6 from the outside world, which is equivalent to forming a blockage to prevent the air between the air pressure sensor 3 and the first waterproof pipe 6 from being discharged. When the pressure of the external liquid balances with the air pressure in the first waterproof pipe 6, the liquid cannot continue to enter, so the purpose of waterproofing the air pressure sensor 3 is achieved.

[0166] In summary, based on the gas pressure liquid level meter of the embodiment, a first sensing air chamber 161 is arranged in the device mounting cavity 16 of the gas pressure liquid level meter, and a gas pressure sensor 3 capable of sensing the gas pressure of the first sensing air chamber 161 is arranged; the shell 1 of the gas pressure liquid level meter is provided with a first waterproof pipe 6 in communication with the first sensing air chamber 161 inside, and the first sensing air chamber 161 is in communication with the atmosphere through the first waterproof pipe 6, realizing the function of the gas pressure sensor 3 sensing the atmospheric pressure. Among them, the flow area of the first waterproof pipe 6 is small, similar to a capillary tube, when the external liquid enters the first waterproof pipe 6, the liquid is easy to form a water column in the first waterproof pipe 6 under the action of liquid tension, the water column can isolate the first sensing air chamber 161 from the outside, which is equivalent to forming a blockage, preventing the air in the first sensing air chamber 161 from being discharged, when the pressure of the external liquid and the air pressure in the first sensing air chamber 161 are balanced, the liquid cannot continue to enter, so as to achieve the purpose of waterproofing in the first sensing air chamber 161. Therefore, the gas pressure liquid level meter of the scheme can meet the function of the gas pressure sensor 3 communicating with the atmospheric pressure and detecting the atmospheric pressure in real time under normal use state, and can effectively cut off from 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 first sensing air chamber 161; in addition, since the first sensing air chamber 161 is provided for communication with the atmospheric pressure, the device mounting 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 mounting cavity 16 can be completely avoided.

[0167] The inventors of the present disclosure have found that when water is encountered, the external water enters the first waterproof pipe 6 through the second air permeable hole 19 and forms a water column in the first waterproof pipe 6, the deeper the water, the greater the external water pressure, the greater the counterpressure required in the device mounting cavity 16, and therefore the water column needs to be compressed to a greater extent. It can be understood that when the volume of the device mounting cavity 16 is larger, 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 are also installed in the device mounting cavity 16, which results in that the space of the device mounting cavity 16 cannot be small, therefore, in order to improve the deep water resistance, extending the first waterproof pipe 6 is one of the ways, however, the space available for arranging the first waterproof pipe 6 on the shell 1 is limited, and it is generally difficult to arrange a first waterproof pipe 6 with a very long length to provide sufficient waterproofing capability.

[0168] In order to overcome the above problems, the first sensing air chamber 161 of the embodiment is a part separated from the device mounting cavity 16, so its volume is obviously smaller than the whole device mounting cavity 16, so that when water enters, the water column in the first waterproof pipe 6 can only compress the air in the first sensing air chamber 161, and it is easier to compress the gas in the smaller first sensing air chamber 161 to have enough pressure compared with compressing the whole device mounting cavity 16. Therefore, based on this improvement, a better deep water resistance can be obtained even if a shorter first waterproof pipe 6 is provided.

[0169] Based on the design of the first waterproof pipe 6, the air pressure liquid level meter of the embodiment can not only resist normal splashing water, but also provide a water-proof capability. In other words, even if the air pressure liquid level meter is completely immersed in water, the first waterproof pipe 6 can still prevent water from entering the first sensing air chamber 161. The air pressure liquid level meter is particularly advantageous in the automatic spraying equipment carried by the unmanned aerial vehicle, because the air pressure liquid level meter of the present solution can still achieve effective waterproof function even if the whole air pressure liquid level meter is immersed in water. When the unmanned aerial vehicle carrying the automatic spraying equipment performs plant protection work and accidentally falls into the water, the unmanned aerial vehicle and the chemical tank can also avoid water entering the air pressure liquid level meter.

[0170] In addition, when the first waterproof pipe 6 of the air pressure liquid level meter is blocked by water, the water in the first waterproof pipe 6 can be shaken out by shaking or knocking, and the first waterproof pipe 6 can be restored to use.

[0171] 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 allowing air to pass but not water, which can meet the demand for air and water resistance. However, in actual application, the inventor found that when the air-permeable film in the waterproof air valve is stuck with water, the whole waterproof air valve needs to be disassembled, the air-permeable film needs to be dried, and then the waterproof air valve needs to be reassembled. The drainage process is relatively complex, 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 stuck with water, 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 waterproof structure with the first waterproof pipe 6 of the present embodiment. The first waterproof pipe 6 is made of transparent pipe, so before use, the user can directly observe whether water has entered the first waterproof pipe 6. When water is found, the water in the first waterproof pipe 6 can be drained by shaking or flicking the first waterproof pipe 6. Compared with the waterproof method using the waterproof air valve, the first waterproof pipe 6 of the present solution is more user-friendly.

[0172] In an embodiment, the air pressure sensor is installed in the first sensing air chamber 161, which includes a first sensitive element for sensing the internal air pressure of the first sensing air chamber 161.

[0173] The air pressure sensor is installed in the first sensing air chamber 161, which is more convenient for sealing and isolating the first sensing air chamber 161. Moreover, the air pressure sensor can occupy most of the space in the first sensing air chamber 161, so as to greatly reduce the air volume of the first sensing air chamber 161, which is more conducive to improving the deep water resistance of the present scheme.

[0174] In an embodiment, in combination with FIGS. 3-4, the device mounting cavity 16 is installed with a main 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 main control circuit board 7 is fixed in the shell 1 and covers the air chamber groove to separate the first sensing air chamber 161.

[0175] The main control circuit board 7 is one of the core components of the air pressure liquid level meter, which is responsible for controlling the operation and data processing of the entire device, and also plays a role in separating space in this design. The main control circuit board 7 is installed in the device mounting cavity 16, and its position is cleverly arranged to cover the air chamber groove. In this way, the main control circuit board 7 naturally becomes a partition, which separates the device mounting cavity 16 into two parts: one part is the main control circuit board 7 and its surrounding area, which is used to install other necessary electronic components; the other part is the covered air chamber groove, i.e. the first sensing air chamber 161. Based on this, the independent first sensing air chamber 161 is separated without adding additional components and complex structures by using the original devices of the air pressure liquid level meter, and the purpose of improving the deep water resistance is achieved. Therefore, the present scheme has the advantages of simple structure and low cost.

[0176] 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 main control circuit board 7 is fixed on the shell base 11.

[0177] The shell 1 is composed of two parts, a shell base 11 and a shell cover 12. The shell base 11 is used as a support and fixing structure, on which various electronic components and parts can be installed. The shell cover 12 covers the shell base 11 and is tightly combined with the shell base 11 through a sealing connection (such as screws, buckles or glue, etc.), so as to form a relatively closed space, i.e. a device installation cavity 16, between the two. An air chamber groove is arranged on the shell base 11, which realizes the installation of the air pressure sensor 3 on the shell base 11, so that the air pressure sensor 3 can be directly aligned with the connector 2 on the shell base 11, and the functions of detecting atmospheric pressure and liquid side pressure of the air pressure sensor 3 are realized. The main control circuit board 7 is fixedly installed on the shell base 11, and the main control circuit board 7 naturally plays a role of separating the first sensing air chamber 161 from the device installation cavity 16.

[0178] 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.

[0179] By introducing the gas-tight ring 113, the contact surface between the main control circuit board 7 and the shell base 11 is better sealed, thereby improving the air tightness of the first sensing air chamber 161.

[0180] 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.

[0181] 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 first sensing air chamber 161.

[0182] 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.

[0183] The combined design of the support boss 111 and the gas-tight groove 112 enables the gas-tight ring 113 to be partially embedded in the gas-tight groove 112 and supported and fixed by the support boss 111, thereby improving the reliability of the installation of the gas-tight ring 113, and in addition, the sealing effect of the gas-tight ring 113 is more significant.

[0184] 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.

[0185] 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, and 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 repair.

[0186] 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.

[0187] 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 first air hole 18 is arranged on the shell base 11 and avoids the connector 2; the air chamber groove includes a sensor installation area 1611 and a bypass narrow air channel 1612, the sensor installation area 1611 is arranged corresponding to the connector 2, and the bypass narrow air channel 1612 communicates the sensor installation area 1611 and the first air hole 18.

[0188] Specifically, the air pressure sensor 3 of the embodiment is a relative air pressure sensor, which at least has a first sensing element and a second sensing element. The first sensing element is used to sense the atmospheric pressure, and the second sensing element is used to sense the pressure of the air chamber connected to the liquid. In order to realize the respective functions of the first sensing element and the second sensing element, in the embodiment, 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 second sensing air chamber 211 in communication with the gas guide pipe 5. After the air pressure sensor 3 is fixedly installed in the device installation cavity 16, the first sensing element is just located at the side of the device installation cavity 16, and the second sensing element is just directed to the second sensing air chamber 211. After the air pressure sensor 3 is installed, the second sensing air chamber 211 and the device installation cavity 16 are just cut off. As long as the device installation cavity 16 is communicated with the atmosphere, the first sensing element can sense the atmospheric pressure, and the second sensing element can sense the air pressure on the liquid side. Preferably, referring to FIG. 5, in order to effectively isolate the second sensing air chamber 211 from the device installation cavity 16, the air pressure sensor 3 includes a sensor main body 31 and a sensor insertion pipe 32. The first sensing element is located at the side of the sensor main body 31, and the second sensing element is aligned with the lumen of the sensor insertion pipe 32. A sealing ring 33 is arranged at the position of the second sensing air chamber 211 in the device installation cavity 16. The sensor insertion pipe 32 is inserted into the sealing ring 33. Thus, the second sensing air chamber 211 can be effectively isolated from the device installation cavity 16 based on the installation of the air pressure sensor 3 and the sealing ring 33.

[0189] The air chamber groove is divided into two parts, a sensor installation area 1611 and a bypass narrow air channel 1612. The air pressure sensor 3 is installed in the sensor installation area 1611, so that the sensor insertion pipe thereof can be directly aligned with the second sensing air chamber 211 in the connector 2, facilitating the installation of the air pressure sensor 3. In addition, the bypass narrow air channel 1612 is used to communicate the first air-permeable hole 18 with the sensor installation area 1611, so that the sensor installation area 1611 can be communicated with the first waterproof pipe 6, realizing the function of the air pressure sensor 3 sensing the atmospheric pressure. This structure can minimize the volume of the entire first sensing air chamber 161 to the greatest extent on the basis of meeting the air permeability requirement, thereby realizing the purpose of improving the deep water waterproofing capability.

[0190] In another embodiment, the side of the shell base 11 away from 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 first air-permeable hole 18 is located at the side of the connector 2 and communicates with the air chamber groove.

[0191] In this embodiment, the first air-permeable hole 18 is directly arranged at the side of the connector 2, so that the first air-permeable hole 18 can directly communicate with the air chamber groove inside the connector 2, obtaining the shortest connection path, and the volume of the air chamber groove can be minimized to the greatest extent.

[0192] 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 first waterproof pipe 6 is coiled around the connector 2 in the ventilation chamber 17.

[0193] The ventilation chamber 17 is arranged on the side of the shell base 11 opposite to the shell upper cover 12, and the first waterproof pipe 6 is accommodated in the ventilation chamber 17, so that the first waterproof pipe 6 can be hidden and protected. In addition, when water immersion accident occurs, external water enters the first waterproof pipe 6 and forms a water column in the first waterproof pipe 6. The deeper the water immersion, the greater the external water pressure, the greater the pressure exerted by the water column on the device mounting cavity 16, the longer the water column formed, and the greater the degree of compression of the gas in the device mounting cavity 16, 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 first 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 waterproofing ability. The first waterproof pipe 6 is arranged in a coiled shape around the connector 2, which can effectively utilize the limited space in the ventilation chamber 17 to arrange the first waterproof pipe 6. Importantly, the coiled first waterproof pipe 6 has the advantage of long length while occupying less space, which is conducive to obtaining a first waterproof pipe 6 with a longer length and better deep water waterproofing ability.

[0194] 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 first waterproof pipe 6 is clamped in the pipe clamping member 114.

[0195] The design of the pipe clamping member 114 enables the first 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 first waterproof pipe 6 during long-term use and prevents water or air leakage caused by unstable connection.

[0196] In an embodiment, the side of the shell base 11 is provided with a second ventilation hole 19, and the ventilation chamber 17 is in communication with the atmosphere through the second ventilation hole 19.

[0197] Specifically, the second 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 of the embodiment is installed, the device mounting cavity 16 is located above the air vent chamber 17, that is, the first air vent 18 is also located above the air vent chamber 17. When it rains, is washed, 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 first air vent 18.

[0198] 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 cannot enter the first waterproof pipe 6, so the user can reduce the number of times of draining the first waterproof pipe 6. The main function of the first waterproof pipe 6 of the embodiment becomes a safety waterproof function. In the conventional use process, external splashing water cannot enter the first waterproof pipe 6. When the water is encountered, based on the arrangement of the first waterproof pipe 6, external water can be prevented from entering the device mounting cavity 16 through the first waterproof pipe 6, so that the normal waterproof function can be achieved even in the water. The air pressure liquid level meter application with the first waterproof pipe 6 has the advantage of being carried by the unmanned aerial vehicle. When the unmanned aerial vehicle carrying the automatic spraying device performs plant protection work, when the unmanned aerial vehicle accidentally falls when flying over the water surface, the unmanned aerial vehicle and the liquid tank fall into the water, and the air pressure liquid level meter can also prevent water from entering the inside.

[0199] In an embodiment, the first waterproof pipe 6 utilizes the surface tension principle of water to form a water column in the first waterproof pipe 6 when water enters to prevent external water from further invading the air pressure sensor 3 through the first waterproof pipe 6.

[0200] Specifically, the first waterproof pipe 6 utilizes the liquid surface tension principle to achieve the waterproof function. Only the inner diameter of the first waterproof pipe 6 needs to be small enough to form a water column when water enters. The first waterproof pipe 6 of this structure has the advantages of simple structure and low cost.

[0201] In an embodiment, the inner diameter of the first waterproof pipe 6 is 1.5-3.5 mm.

[0202] The inner diameter of the first waterproof pipe 6 is set to 1.5-3.5 mm, which can meet the normal air permeability requirement and also achieve the function of forming a water column in the first waterproof pipe 6 by utilizing the liquid surface tension to achieve waterproofing.

[0203] In another aspect, a liquid storage device is provided, comprising a liquid storage tank and the air pressure liquid level gauge as described above, the housing 1 of the air pressure liquid level gauge is installed on the top of the liquid storage tank, and the air guide pipe 5 of the air pressure liquid level gauge extends to the bottom of the liquid storage tank from the end of the housing 1.

[0204] Similarly, the air pressure liquid level gauge in the liquid storage device of the present embodiment has the advantage of good waterproof capability.

[0205] In 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 the pesticide liquid in the liquid storage device.

[0206] The carrier can be an unmanned vehicle, a drone, a manually driven vehicle, etc.

[0207] 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.

[0208] Based on the liquid storage device of the present embodiment, similarly, the air pressure liquid level gauge in the plant protection device of the present embodiment has the advantages of strong waterproof capability and long service life.

[0209] 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 "first", "second" are only used to distinguish in the description, and have no special meaning.

[0210] In the description of the present specification, the description referring to the terms "an embodiment", "an example" and the like means that the specific features, structures, materials or characteristics described in connection 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.

[0211] 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.

[0212] 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 application relates to a shell (1) comprising a side wall (13), a top cover plate (14) and an inner partition plate (15) connected with the side wall (13) respectively, a device mounting cavity (16) formed between the top cover plate (14) and the inner partition plate (15), and a gas permeation chamber (17) formed on the side of the inner partition plate (15) away from the top cover plate (14); the gas permeation chamber (17) is communicated with the atmosphere, and the inner partition plate (15) is provided with a first gas permeation hole (18) communicated with the device mounting cavity (16) and the gas permeation chamber (17), so that the device mounting cavity (16) can be ventilated with the atmosphere. A gas pressure sensor is arranged in the device mounting cavity (16), and the gas pressure sensor comprises a first sensitive element for sensing the gas pressure of the device mounting cavity (16). A first waterproof pipe (6) is arranged in the gas permeation chamber (17), one end of the first waterproof pipe (6) is connected with the first gas permeation hole (18), and the other end is a free end, so that the device mounting cavity (16) is ventilated with the gas permeation chamber (17) through the first waterproof pipe (6).

2. The air pressure liquid level gauge according to claim 1, characterized in that The first waterproof pipe (6) comprises a first waterproof pipe body and a ventilation connector connected with each other, and the ventilation connector is connected with the first gas permeation hole (18) in a plug-in mode.

3. The air pressure liquid level gauge according to claim 2, characterized in that A flexible pipe (23) is connected between the first waterproof pipe body and the ventilation connector, and the inner diameter of the flexible pipe (23) is larger than that of the first waterproof pipe body.

4. The air pressure liquid level gauge according to claim 3, characterized in that The inner partition plate (15) is provided with a pipe clamping element (114) on the side away from the top cover plate (14), and the first waterproof pipe (6) is clamped on the pipe clamping element (114).

5. A gas pressure liquid level gauge according to any one of claims 2 to 4, characterised in that, The inner partition plate (15) is provided with a connector (2) protruding away from the top cover plate (14) and used for connecting a gas guide pipe (5), and the first waterproof pipe (6) is arranged around the connector (2).

6. The air pressure liquid level gauge according to claim 5, wherein The pipe clamping element (114) comprises an arc-shaped pipe clamping plate (1141), the arc-shaped pipe clamping plate (1141) is arranged on the side of the connector (2) away from the first gas permeation hole (18), and a first pipe clamping groove capable of clamping the first waterproof pipe (6) is formed between the arc-shaped pipe clamping plate (1141) and the connector (2).

7. The air pressure liquid level gauge according to claim 6, characterized in that The pipe clamping element (114) comprises a clamping block (1142) arranged close to the first gas permeation hole (18), and the clamping block (1142) is provided with a second pipe clamping groove capable of clamping the first waterproof pipe (6).

8. The air pressure liquid level gauge according to claim 7, characterized in that The first waterproof pipe (6) utilizes the surface tension principle of water, and a water column is formed in the first waterproof pipe (6) when water enters, so as to prevent external water from further invading the gas pressure sensor (3) through the first waterproof pipe (6).

9. A gas pressure liquid level gauge according to any one of claims 2 to 8, characterised in that, The inner diameter of the first waterproof pipe (6) is 1.5-3.5 mm.

10. The air pressure liquid level gauge according to claim 9, characterized in that The side wall (13) is provided with a second gas permeation hole (19) communicated with the gas permeation chamber (17), so that the gas permeation chamber (17) is communicated with the atmosphere.

11. A gas pressure liquid level gauge according to any one of claims 1 to 10, characterised in that, ​ 12. The air pressure liquid level gauge according to claim 11, characterized in that The shell (1) comprises a shell base (11) and a shell upper cover (12), the shell base (11) comprises a first surrounding wall plate (131) and the inner partition plate (15) connected with each other; the shell upper cover (12) comprises a second surrounding wall plate (132) and the top cover plate (14) connected with each other, the shell upper cover (12) is buckled on the shell base (11), the first surrounding wall plate (131) and the second surrounding wall plate (132) are connected to form the side surrounding wall (13), and the second air hole (19) is arranged on the first surrounding wall plate (131).

13. The air pressure liquid level gauge according to claim 12, characterized in that The inner partition plate (15) is arranged protruding to the side where the top cover plate (14) is located relative to the first surrounding wall plate (131), an inner cavity of the second surrounding wall plate (132) corresponds to the outer dimension of the inner partition plate (15), and the inner partition plate (15) is arranged embedded in the second surrounding wall plate (132).

14. The air pressure liquid level gauge according to claim 13, characterized in that The second surrounding wall plate (132) comprises a first surrounding wall part (1321) and a second surrounding wall part (1322) connected in a stepped structure, a step part (1323) parallel to the inner partition plate (15) is formed between the first surrounding wall part (1321) and the second surrounding wall part (1322), a waterproof ring (1325) abutting against the step part (1323) is arranged on the inner side of the first surrounding wall part (1321), and the inner partition plate (15) is embedded in the first surrounding wall part (1321) and abuts against the waterproof ring (1325).

15. The air pressure liquid level gauge according to claim 14, characterized in that The step part (1323) is provided with an annular groove (1324), and the waterproof ring (1325) is embeddedly arranged in the annular groove (1324).

16. The air pressure liquid level gauge according to claim 15, wherein A circumferential flange (151) is arranged on the inner partition plate (15), the circumferential flange (151) is embedded in the annular groove (1324) to abut against the waterproof ring (1325).

17. A gas pressure liquid level gauge according to any one of claims 1 to 16, wherein The side surrounding wall (13) and the top cover plate (14) are in an integrated structure, and the inner partition plate (15) is embeddedly arranged in the side surrounding wall (13).

18. A gas pressure liquid level gauge according to any one of claims 1 to 17, wherein An installation boss is arranged on the side of the side surrounding wall (13) away from the top cover plate (14), and the installation boss is provided with an installation hole.

19. The gas pressure liquid level gauge according to any one of claims 1-18, characterized in that The air pressure liquid level meter is applied to a pesticide liquid tank for plant protection.

20. A liquid storage device, characterized by The air pressure liquid level meter comprises a liquid storage tank and the air pressure liquid level meter according to any one of claims 1-19.

21. An agricultural protection apparatus, comprising: The air pressure liquid level meter comprises a carrier, a spraying system and the liquid storage device according to claim 20, the spraying system and the liquid storage device are mounted on the carrier, and the spraying system is used for pumping and atomizing spraying pesticide liquid in the liquid storage device.

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