A pressure control valve and system for agricultural spraying and irrigation

Abstract

The present application discloses a pressure control valve and its system for agricultural spraying and irrigation, including a supply device for providing pressure liquid, a plurality of pressure control valves respectively connected to the outlet end of the supply device through pipelines, and any of the pressure control valves are respectively connected to a spray nozzle and an irrigation nozzle through pipelines; the pressure control valve is implemented by the following pressure control valve, the spray nozzle is connected to the high-pressure outlet, and the irrigation nozzle is connected to the low-pressure outlet. The present application creatively adds the operation of automatically selecting different outlets according to pressure, corresponding to different nozzles to realize different functions, such as spraying liquid medicine or irrigation, to realize the integration of the irrigation system and the spraying system, save the maintenance cost investment of the garden system, and improve the convenience. The whole system does not need to be debugged, and only needs to change the pressure of the supply device according to demand, which is convenient and fast.

Description

Technical Field

[0001] The present application relates to the technical field of agricultural and forestry machinery, in particular to the technical field of irrigation auxiliary devices for agriculture / forestry, flow control valves and their systems, and specifically to a pressure control valve and its system for dual-purpose agricultural spraying and irrigation. Background Art

[0002] In order to improve production efficiency, the existing agricultural and forestry planting has generally formed industrialization, clustering and batching, gradually developing from traditional scattered planting to small-scale planting, and finally to large-scale, standardized and industrialized planting. In the planting process of agriculture and forestry, the two most indispensable tasks are fertilization and irrigation and spraying of pesticides to eliminate pests.

[0003] The most widely used batch spraying operations for existing fruit orchards are low-cost pipeline spraying systems and high-cost aircraft aerial spraying. The advantages of using a spraying system are low cost, high degree of automation, and low manual labor. The disadvantages are that the spraying operation surface is limited, the spraying area between multiple nozzles is fixed, the blind area is obvious, and uniform full coverage cannot be achieved, and a large amount of liquid medicine is wasted. Aerial spraying by aircraft has high uniformity and wide coverage, but the cost of aircraft spraying is very huge, and it is not suitable for small and medium-sized plantations.

[0004] There is no unified, practical, and widely used irrigation system for batch irrigation in gardens. Most of them are based on laying pipes underground, and the pressure is uniformly supplied by the machine room to supply water to the branch pipes for irrigation. The effectiveness and uniformity of irrigation depend on the density of pipe laying. Since the irrigation operation requires a large flow rate and a very small pressure requirement, while the spraying operation requires a small flow rate and a very high pressure requirement, there is currently no system that can meet both irrigation and spraying operations. In order to solve the problem of spraying irrigation in large-scale agriculture and forestry, it is extremely necessary to provide a system with a high degree of integration, good reliability, and compatibility with multiple functions, which can greatly reduce infrastructure investment, reduce subsequent labor resource investment, and unnecessary waste of liquid medicine. Summary of the invention

[0005] In order to solve the practical problems in the prior art that the spraying and pest control system and the irrigation system cannot be combined into one, and need to be independently set up, installed and operated, resulting in high cost investment and poor operating effect, the present application provides a pressure control valve and its system for agricultural spraying and irrigation, which realizes the combination of the high pressure, low flow, and strong atomization requirements required for spraying operations and the low pressure and high flow requirements required for irrigation, and automatically realizes them through a set of systems according to actual needs, thus solving the many problems in the prior art of separately laying pipelines, installing systems, and independently operating and maintaining them, resulting in high cost investment and large manpower investment.

[0006] This application creatively proposes a new pressure control valve, which can automatically select different outlets by providing different pressures, and achieve different operation purposes and effects by installing different nozzles at different outlets. In this way, only one set of the system of this application is needed to perform spraying or irrigation operations according to actual needs; the whole system adopts a purely mechanical structure setting, does not rely on any electrical system, communication system support, has high reliability, and has strong adaptability to the environment, achieving extremely low maintenance cost investment to achieve long-term use effects.

[0007] In order to achieve the above purpose, the technical solution adopted in this application is:

[0008] A dual-purpose system for agricultural spraying and irrigation, comprising a supply device for providing pressurized liquid, and a plurality of pressure control valves respectively connected to the outlet ends of the supply device through pipelines, wherein any of the pressure control valves is respectively connected to a spray nozzle and an irrigation nozzle through pipelines; the pressure control valve is implemented by the following pressure control valve, wherein the spray nozzle is connected to the high-pressure outlet, and the irrigation nozzle is connected to the low-pressure outlet.

[0009] Brief description of working principle: When using this system, if you need to spray medicine, you only need to replace the supply medium of the supply device with the liquid medicine that needs to be sprayed. The supply device adopts existing technology, such as centralized supply pump room, machine room, liquid increase pump, etc. After the medium is pressurized by the supply device, it will be sent to multiple pressure control valves. The pressure control valve will choose to spray from the high-pressure outlet or the low-pressure outlet according to the medium pressure provided by the supply device, and finally spray the liquid medicine through the corresponding spray nozzle or irrigate through the irrigation nozzle. The key to this system is that the pressure control valve can automatically select different outlets to discharge according to the level of medium pressure, such as high-pressure outlet or low-pressure outlet. As the key to this system, the pressure control valve selects the corresponding outlet according to the input liquid medium pressure, and corresponds to different applicable nozzles for atomization spraying or irrigation. Then the structural reliability of the pressure control valve directly determines the stability of the system. In order to ensure that the system can operate according to actual needs, the pressure control valve structure used in this system is set as follows:

[0010] A pressure control valve for agricultural spraying and irrigation, comprising a housing, on which a water inlet, a high-pressure outlet and a low-pressure outlet are respectively arranged, the water inlet is connected to a water inlet pipe, the high-pressure outlet is connected to a high-pressure outlet pipe, and the low-pressure outlet is connected to a low-pressure outlet pipe, the water inlet pipe is connected to the high-pressure outlet pipe through a blind pipe, a first piston and a first elastic structure for abutting against the first piston to block the blind pipe are slidably arranged in the blind pipe;

[0011] The water inlet pipe and the low-pressure water outlet pipe are connected through a low-pressure bypass pipe and a high-pressure cut-off pipe respectively arranged in parallel. A second piston is slidably installed in the high-pressure cut-off pipe. The end of the second piston close to the water inlet pipe is connected to a second elastic structure for controlling the position of the second piston.

[0012] As a feasible structural setting, preferably, the first elastic structure is a first spring connecting the first piston and the housing, and when the first piston is in a blind pipe blocking state, the first spring is in a natural state or a compressed state.

[0013] As another feasible structural setting, preferably, the first elastic structure includes a first permanent magnet arranged in the first piston and a second permanent magnet arranged on the circumferential side wall of the blind tube close to one end of the water inlet pipe and attracted to the first permanent magnet and / or a third permanent magnet arranged away from one end of the water inlet pipe and repelled from the first permanent magnet.

[0014] Further preferably, a first convex ring and a second convex ring for limiting the movement limit position of the first piston and contacting with the end surface of the first piston to form a sealing structure are respectively provided in the blind tube.

[0015] As a feasible structural setting, preferably, the second elastic structure is a second spring connecting the second piston and the shell, and when the low-pressure bypass pipe is in a connected state with the low-pressure water outlet pipe, the second spring is in a natural state or a stretched state.

[0016] As another feasible structural setting, preferably, the second elastic structure includes a fourth permanent magnet arranged in the second piston and a fifth permanent magnet arranged on the circumferential side wall of the high-pressure cut-off tube near one end of the water inlet pipe and attracted to the fourth permanent magnet and / or a sixth permanent magnet arranged in the circumferential side wall of the low-pressure water outlet pipe and repelled from the fourth permanent magnet.

[0017] Preferably, a third convex ring for limiting the lower limit of the movement position of the second piston is provided in the high-pressure cut-off pipe, and a fourth convex ring for limiting the upper limit of the movement position of the second piston is provided in the low-pressure water outlet pipe.

[0018] As another structural setting of the high-pressure cut-off tube, the second piston adopts a conical setting. The high-pressure cut-off tube has a conical tube structure for accommodating the second piston. The end of the conical tube structure close to the low-pressure water outlet pipe has a convergent annular section for achieving contact sealing with the conical surface of the second piston.

[0019] Beneficial Effects

[0020] The present application creatively adds the function of automatically selecting different outlets according to the pressure, and corresponding to different nozzles to realize different functions, such as spraying liquid medicine or irrigation, thereby realizing the integration of the irrigation system and the spraying system, saving the maintenance cost of the garden system and improving the convenience. The whole system does not need to be debugged, and it only needs to change the pressure of the supply device according to the demand, which is convenient and fast.

[0021] The pressure control valve provided in the present application adopts a dual-piston linkage, and selects a conduction method to automatically open a piston for different pressures, and closes the other piston to switch the pipeline. The entire pressure controller is implemented with a purely mechanical structure, does not require any electronic components and sensors to be connected, does not require communication module access, is not limited by the use environment, has high stability and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 It is a three-dimensional structural diagram of the pressure control valve;

[0024] Figure 2 yes Figure 1 A top view of

[0025] Figure 3 yes Figure 2 Full section view with the midline cutting symbol AA;

[0026] Figure 4 The pressure control valve is in high-pressure spraying working state;

[0027] Figure 5 The pressure control valve is in low-pressure irrigation working state;

[0028] Figure 6 It is a schematic diagram of the system structure of the present invention.

[0029] In the figure: 00-supply device; 01-pressure control valve; 02-spray nozzle; 03-irrigation nozzle; 1-shell; 2-water inlet; 3-high-pressure outlet; 4-low-pressure outlet; 5-mounting ear; 6-water inlet pipe; 7-high-pressure outlet pipe; 8-low-pressure bypass pipe; 9-high-pressure cut-off pipe; 10-low-pressure outlet pipe; 11-blind pipe; 12-first spring; 13-first piston; 14-first convex ring; 15-second convex ring; 16-second piston; 17-second spring; 18-third convex ring; 19-fourth convex ring. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In the description of this application, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on this application. In addition, if the terms "first", "second", etc. appear in the description of this application, they are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0034] In addition, if the terms "horizontal" or "vertical" appear in the description of this application, it does not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0035] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0036] Embodiment 1:

[0037] A pressure control valve for agricultural spraying and irrigation, such as Figure 1 and Figure 2 As shown, it comprises a shell 1, on which a water inlet 2, a high-pressure outlet 3 and a low-pressure outlet 4 are respectively provided, the water inlet 2 is connected to a water inlet pipe 6, the high-pressure outlet 3 is connected to a high-pressure water outlet pipe 7, and the low-pressure outlet 4 is connected to a low-pressure water outlet pipe 10, the water inlet pipe 6 is connected to the high-pressure water outlet pipe 7 through a blind pipe 11, and a first piston 13 and a first elastic structure for abutting against the first piston 13 to block the blind pipe 11 are slidably provided in the blind pipe 11;

[0038] The water inlet pipe 6 is connected to the low-pressure water outlet pipe 10 through a low-pressure bypass pipe 8 and a high-pressure cut-off pipe 9 respectively arranged in parallel. A second piston 16 is slidably installed in the high-pressure cut-off pipe 9. The end of the second piston 16 close to the water inlet pipe 6 is connected to a second elastic structure for controlling the position of the second piston 16.

[0039] Working principle:

[0040] When the liquid enters the pressure control valve from the water inlet 2, it first enters the water inlet pipe 6 connected to the water inlet 2. Due to the action of the first elastic structure, the first piston 13 is at the lower part of the blind pipe 11. Figure 3 As shown, the water inlet pipe 6 and the water outlet pipe 7 are in a blocked state, and the liquid cannot connect the water inlet pipe 6 and the water outlet pipe 7 through the blind pipe 11. At this time, no liquid will flow out of the high-pressure outlet 3. The liquid continues to pass through the water inlet pipe 6 and then enters the low-pressure bypass pipe 8. Due to the effect of the second elastic structure, the second piston 16 is in the high-pressure cut-off pipe 9 at this time, and the low-pressure bypass pipe 8 and the low-pressure outlet pipe 10 are not blocked. Therefore, under low-pressure conditions, no matter how small the liquid flow rate is, the liquid can pass through the water inlet 2 → water inlet pipe 6 → low-pressure bypass pipe 8 → low-pressure outlet pipe 10 → low-pressure outlet 4 in sequence. Specifically, Figure 5 As shown, it is realized that when the pressure is low, the water flows in from the water inlet 2 and out from the low-pressure outlet 4. This state is suitable for irrigation purposes. Since it is necessary to irrigate a forest or crop, it is only necessary to transport a preset amount of water to a designated area according to demand. There is no requirement for pressure. Generally, as long as there is 1Mpa, the irrigation demand can be met. The best effect of irrigation is a small flow rate and continuous action, rather than inputting too much water in a very short time, which can easily lead to soil compaction. Therefore, when irrigation is needed, a low-pressure medium, such as water, is provided, and the pressure control valve can automatically discharge it from the low-pressure outlet 4.

[0041] When pest control is required, the liquid pressure containing the medicine is very high, generally reaching 20Mpa, to achieve the effect of nozzle atomization. When the high-pressure aqueous solution enters the water inlet 2, as described above, it enters the water inlet pipe 6 and the low-pressure bypass pipe 8, and finally is discharged to the low-pressure outlet 4 through the low-pressure outlet pipe 10; however, since the input liquid pressure is very high, the pressure difference between the two end surfaces of the first piston 13 and the second piston 16 is very large at this time. Under the action of the high-pressure liquid medium, the first piston 13 and the second piston 16 will respectively overcome the first elastic structure and the second elastic structure to move upward, such as Figure 3 and Figure 4 When the first piston 13 is moved upward by the liquid pressure to overcome the resistance provided by the first elastic structure, the blind pipe 11 is opened, and the water inlet pipe 6 and the high-pressure water outlet pipe 7 are connected, and the liquid passes through the high-pressure water outlet pipe 7 to the high-pressure outlet 3, and is finally discharged through the high-pressure outlet 3; at the same time, the second piston 16 overcomes the resistance provided by the second elastic structure and continues to move upward until the intersection of the low-pressure bypass pipe 8 and the low-pressure water outlet pipe 10 is blocked, and the cut-off state is achieved. At this time, the liquid medium can only be sprayed out through the high-pressure outlet 3.

[0042] After the above principle discussion, combined with the instructions attached Figure 4 The high voltage working state and attached Figure 5 The low-pressure working state shown can be clearly understood, and the pressure controller provided in this embodiment can meet the needs of irrigation and spraying, and can select high-pressure outlet 3 or low-pressure outlet 4 for discharge according to different pressures. This pressure control valve does not rely on any electrical structure and communication unit, is not affected or limited by any use environment, and has strong practicality and high reliability.

[0043] Embodiment 2:

[0044] On the basis of Example 1, this embodiment provides a structural setting, wherein the first elastic structure is a first spring 12 connecting the first piston 13 and the housing 1. When the first piston 13 is in the state of blocking the blind pipe 11, the first spring 12 is in a natural state or a compressed state. The elastic coefficient of the first spring 12 is selected according to the actual operating pressure and the force area of ​​the first piston 13. As long as the first spring 12 can maintain the initial state of the first piston 13 under the pressure state used for low-pressure irrigation, and the first piston 13 can overcome the elastic force provided by the first spring 12 and move upward until the blind pipe 11 is opened under the pressure state used for high-pressure spraying. Since the pressure difference between spraying and irrigation is very large, there are infinite combinations that can be selected under the above conditions. Any specific solution selected within this range can achieve the same technical effect. This is obvious to those skilled in the art, and the essence belongs to the technical scope disclosed in this embodiment, so it will not be described in detail here. All the structural surfaces used should have an anti-corrosion layer that overcomes the contact with the liquid required in the working state, and the selection of the coating adopts the existing electroplating or material penetration process, such as galvanizing, copper plating, carburizing treatment, etc.

[0045] Embodiment 3:

[0046] This embodiment also provides another achievable structural setting, wherein the first elastic force structure includes a first permanent magnet disposed in the first piston 13 and a second permanent magnet disposed on the circumferential side wall of the blind tube 11 close to one end of the water inlet pipe 6 and attracting the first permanent magnet and / or a third permanent magnet disposed at one end away from the water inlet pipe 6 and repelling the first permanent magnet. Compared with Embodiment 2, this embodiment omits the structure exposed in the pipeline, such as a spring, and thus omits the anti-corrosion structural treatment, so that the service life is longer than that of the structure described in Embodiment 2.

[0047] In this embodiment, a first convex ring 14 and a second convex ring 15 are respectively disposed in the blind tube 11 to limit the movement limit position of the first piston 13 and to contact with the end surface of the first piston 13 to form a sealing structure.

[0048] Embodiment 4:

[0049] This embodiment provides a feasible structural setting, wherein the second elastic structure is a second spring 17 connecting the second piston 16 and the housing 1, and when the low-pressure bypass pipe 8 is in a connected state with the low-pressure water outlet pipe 10, the second spring 17 is in a natural state or a stretched state. The principle is similar to that of Embodiment 2 and will not be described in detail here.

[0050] Embodiment 5:

[0051] As another achievable structural setting, in this embodiment, the second elastic structure includes a fourth permanent magnet disposed in the second piston 16 and a fifth permanent magnet disposed on the circumferential side wall of the high-pressure cut-off pipe 9 near one end of the water inlet pipe 6 and mutually attracted to the fourth permanent magnet and / or a sixth permanent magnet disposed in the circumferential side wall of the low-pressure water outlet pipe 10 and mutually repelled from the fourth permanent magnet. The principle described in this embodiment is substantially the same as the working principle of the first piston 13 in Example 3, and will not be repeated here.

[0052] In this embodiment, a third convex ring 18 for limiting the lower limit of the movement position of the second piston 16 is provided in the high-pressure cut-off pipe 9 , and a fourth convex ring 19 for limiting the upper limit of the movement position of the second piston 16 is provided in the low-pressure water outlet pipe 10 .

[0053] Embodiment 6:

[0054] This embodiment further provides another structural setting of the high-pressure cut-off tube 9 on the basis of embodiment 5, wherein the second piston 16 is set in a conical shape, and the high-pressure cut-off tube 9 has a conical tube structure for accommodating the second piston 16, and the conical tube structure has a converging annular section at one end close to the low-pressure water outlet pipe 10, which realizes contact sealing with the conical surface of the second piston 16. When the second piston 16 is pushed by the high-pressure liquid, the conical surface of the conical second piston 16 contacts the converging annular section to realize a sealing structure, thereby achieving the effect of sealing and blocking the low-pressure water outlet pipe 10. Due to the conical structure setting, no matter how large the liquid pressure is, the conical piston will only be pressed tightly against the converging annular section, further improving the sealing effect. When the pressure provided by the liquid decreases, under the action of the second elastic structure, the second piston 16 returns to its initial position.

[0055] Embodiment 7:

[0056] In conjunction with the instruction manual Figure 6 A dual-purpose system for agricultural spraying and irrigation is shown, comprising a supply device 00 for providing pressurized liquid, and a plurality of pressure control valves 01 respectively connected to the outlet ends of the supply device 00 through pipelines, and any of the pressure control valves 01 is respectively connected to a spray nozzle 02 and an irrigation nozzle 03 through pipelines; the pressure control valve 01 is implemented by the following pressure control valve, the spray nozzle 02 is connected to the high-pressure outlet 3, and the irrigation nozzle 03 is connected to the low-pressure outlet 4.

[0057] Brief description of working principle: When using this system, if you need to spray medicine, you only need to replace the supply medium of the supply device 00 with the liquid medicine to be sprayed. The supply device 00 adopts existing technology, such as a centralized supply pump room, a machine room, a liquid increase pump, etc. After the medium is pressurized by the supply device 00, it will be sent to multiple pressure control valves 01. The pressure control valve 01 will choose to spray from the high-pressure outlet 3 or the low-pressure outlet 4 according to the medium pressure provided by the supply device 00, and finally spray the liquid medicine through the corresponding spray nozzle 02 or irrigate through the irrigation nozzle 03. The key to this system is that the pressure control valve 01 can automatically select different outlets to discharge according to the level of medium pressure, such as high-pressure outlet 3 or low-pressure outlet 4. As the key to this system, the pressure control valve selects the corresponding outlet according to the input liquid medium pressure, and corresponds to different applicable nozzles for atomization spraying or irrigation. Then the structural reliability of the pressure control valve directly determines the stability of the system operation. In order to ensure that the system can operate according to actual needs, the pressure control valve structure used in this system is as shown in the above embodiments 1-5.

[0058] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pressure control valve for agricultural spraying and irrigation, comprising a housing (1), characterized in that: The shell (1) is provided with a water inlet (2), a high-pressure outlet (3) and a low-pressure outlet (4), respectively; the water inlet (2) is connected to a water inlet pipe (6), the high-pressure outlet (3) is connected to a high-pressure outlet pipe (7), and the low-pressure outlet (4) is connected to a low-pressure outlet pipe (10); the water inlet pipe (6) and the high-pressure outlet pipe (7) are connected via a blind pipe (11), a first piston (13) and a first elastic structure for abutting against the first piston (13) to block the blind pipe (11) are slidably arranged in the blind pipe (11); the water inlet pipe (6) and the low-pressure outlet pipe (10) are connected via a low-pressure bypass pipe (8) and a high-pressure cut-off pipe (9) arranged in parallel, respectively; a second piston (16) is slidably installed in the high-pressure cut-off pipe (9), and an end of the second piston (16) close to the water inlet pipe (6) is connected to a second elastic structure for controlling the position of the second piston (16); The first elastic structure is a first spring (12) connecting the first piston (13) and the housing (1), and when the first piston (13) is in a blind tube (11) blocking state, the first spring (12) is in a natural state or a compressed state; The second elastic structure is a second spring (17) connecting the second piston (16) and the housing (1); when the low-pressure bypass pipe (8) and the low-pressure water outlet pipe (10) are in a connected state, the second spring (17) is in a natural state or a stretched state.

2. A pressure control valve for agricultural spraying and irrigation according to claim 1, characterized in that: The first elastic force structure comprises a first permanent magnet arranged in the first piston (13), and a second permanent magnet arranged on the circumferential side wall of the blind tube (11) close to one end of the water inlet pipe (6) and mutually attracted to the first permanent magnet, and / or a third permanent magnet arranged on one end away from the water inlet pipe (6) and mutually repelled from the first permanent magnet.

3. A pressure control valve for agricultural spraying and irrigation according to any one of claims 1-2, characterized in that: A first convex ring (14) and a second convex ring (15) are respectively arranged in the blind tube (11) for limiting the movement limit position of the first piston (13) and contacting with the end surface of the first piston (13) to form a sealing structure.

4. A pressure control valve for agricultural spraying and irrigation according to claim 1, characterized in that: The second elastic structure comprises a fourth permanent magnet arranged in the second piston (16), a fifth permanent magnet arranged on the circumferential side wall of the high-pressure cut-off pipe (9) near one end of the water inlet pipe (6) and attracting the fourth permanent magnet, and / or a sixth permanent magnet arranged in the circumferential side wall of the low-pressure water outlet pipe (10) and repelling the fourth permanent magnet.

5. A pressure control valve for agricultural spraying and irrigation according to claim 1 or 4, characterized in that: A third convex ring (18) for limiting the lower limit of the movement position of the second piston (16) is arranged in the high-pressure cut-off pipe (9), and a fourth convex ring (19) for limiting the upper limit of the movement position of the second piston (16) is arranged in the low-pressure water outlet pipe (10).

6. A pressure control valve for agricultural spraying and irrigation according to claim 1, characterized in that: The second piston (16) is arranged in a conical shape, the high-pressure cut-off tube (9) has a conical tube structure for accommodating the second piston (16), and the end of the conical tube structure close to the low-pressure water outlet pipe (10) has a converging annular cross-section for achieving contact sealing with the conical surface of the second piston (16).

7. A dual-purpose system for agricultural spraying and irrigation, characterized in that: The invention comprises a supply device (00) for providing pressurized liquid, and a plurality of pressure control valves (01) respectively connected to the outlet ends of the supply device (00) through pipelines, wherein each of the pressure control valves (01) is respectively connected to a spray nozzle (02) and an irrigation nozzle (03) through pipelines; the pressure control valve (01) is implemented by the pressure control valve described in claims 1 to 3, 5, and 6, the spray nozzle (02) is connected to the high-pressure outlet (3), and the irrigation nozzle (03) is connected to the low-pressure outlet (4).

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