Electromagnetic Flowmeter and Agricultural Plant Protection Machine

Abstract

The present invention provides an electromagnetic flowmeter and an agricultural plant protection machine, which include a bracket (401), a pipeline (402), measuring electrodes (403), a coil assembly (404) and two signal acquisition boards (405). One end of the pipeline is arranged on the bracket; the measuring electrodes include two first electrodes, the two first electrodes are oppositely arranged on both sides of the outer side wall of the pipeline, and respectively pass through the side wall of the pipeline to contact the liquid flowing through the pipeline, and the detection ends of the two first electrodes are oppositely arranged; the coil assembly is arranged on one side of the outer side wall of the pipeline, and the axial direction of the coil assembly is orthogonal to the connection line of the detection ends of the two first electrodes; the two signal acquisition boards are used for acquiring the signals of the first electrodes on the corresponding side; the pipeline includes two oppositely arranged planar electrode mounting surfaces (4021), first electrode mounting holes are formed on the electrode mounting surfaces, the detection ends of the first electrodes pass through the first electrode mounting holes, and the end surfaces of the detection ends of the first electrodes are substantially flush with the inner side wall of the pipeline.

Description

Technical Field

[0001] The present invention relates to the field of flow detection, and in particular to an electromagnetic flowmeter and an agricultural plant protection machine. Background Art

[0002] With the gradual popularization of agricultural plant protection machines, the requirements for spraying accuracy are getting higher and higher. Too low spraying flow rate will cause missed spraying or insufficient protection, while too high flow rate will cause adverse effects such as burning seedlings. In addition, during plant protection operations, the amount of sprayed medicine is an important parameter. The existing liquid level gauges have limited accuracy, which will affect the flyer's statistics of the operation area. In order to improve the control accuracy of spraying and the calculation accuracy of the amount of sprayed medicine, electromagnetic flowmeters are applied.

[0003] The potential detection of the existing electromagnetic flowmeter is realized by a pair of metal electrodes inserted into the pipeline, called detection electrodes. Currently, the pipeline is generally circular, and the end face of the detection electrode is flat. Therefore, after the detection electrode extends into the pipeline, it will necessarily extend a certain length and cannot be flush with the pipeline, which will cause the flow field to be disordered and affect the measurement accuracy; the protruding detection electrode will also accumulate dirt and will block the electromagnetic flowmeter in the long run. Summary of the Invention

[0004] The present invention provides an electromagnetic flowmeter and an agricultural plant protection machine.

[0005] Specifically, the present invention is realized through the following technical solutions:

[0006] According to the first aspect of the present invention, there is provided an electromagnetic flowmeter, which includes:

[0007] A bracket;

[0008] A plurality of pipelines, one end of the pipeline is arranged on the bracket, and the opening end of the pipeline close to the bracket is exposed outside the bracket;

[0009] A plurality of measurement electrodes, which cooperate with the pipeline. The measurement electrodes include two first electrodes, and the two first electrodes are oppositely arranged on both sides of the outer side wall of the pipeline. After the detection ends of the two first electrodes pass through the side wall of the pipeline, they can contact the liquid flowing through the pipeline, and the detection ends of the two first electrodes are oppositely arranged;

[0010] A coil assembly for generating an electromagnetic field, which is arranged on one side of the outer side wall of the pipeline, and the axis of the coil assembly is orthogonal to the connection line of the detection ends of the two first electrodes; and

[0011] Two signal acquisition boards, which are arranged on the same side of the outer side wall of the pipeline corresponding to the two first electrodes, and the signal acquisition board is electrically coupled to the first electrode on the corresponding side for acquiring the signal of the first electrode on the corresponding side;

[0012] Among them, the electromagnetic flowmeter includes a main water inlet, and the main water inlet is respectively communicated with a plurality of the pipelines at the open end of the bracket; the plurality of pipelines are arranged substantially in parallel, the plurality of measuring electrodes are correspondingly matched with the plurality of pipelines, and the first electrodes of the plurality of measuring electrodes are arranged in two rows opposite to each other.

[0013] Optionally, the pipeline includes two oppositely arranged planar electrode mounting surfaces, first electrode mounting holes are formed on the electrode mounting surfaces, the detection ends of the first electrodes respectively pass through the first electrode mounting holes, and the end surfaces of the detection ends of the first electrodes are substantially flush with the inner side wall of the pipeline, and the flow channel cross-section of the pipeline is a regular polygon.

[0014] Optionally, the two first electrodes are coaxially arranged, and the axial direction of the two first electrodes is perpendicular to the axial direction of the coil assembly;

[0015] Or, the signal acquisition board is provided with a through hole, and the signal acquisition board is sleeved on the tail end of the first electrode through the through hole to realize the electrical connection between the signal acquisition board and the first electrode; the tail end and the detection end of the first electrode are respectively located at both ends of the first electrode.

[0016] Optionally, the electromagnetic flowmeter further includes two second electrodes, the two second electrodes are respectively arranged at the two open ends of the pipeline, and the two second electrodes are arranged on both sides of one of the first electrodes. After the heads of the two second electrodes respectively pass through the side wall of the pipeline, they can contact the liquid flowing through the pipeline;

[0017] A second electrode mounting hole is further formed on one of the electrode mounting surfaces, the head of the second electrode passes through the second electrode mounting hole, and the head end surface of the second electrode is substantially flush with the inner side wall of the pipeline;

[0018] The tails of the two second electrodes are in contact with the signal acquisition board on the corresponding side to be grounded.

[0019] Optionally, the signal acquisition board is provided with a grounding hole at a position corresponding to the second electrode, and the tail of the second electrode is matched with the grounding hole to realize the grounding of the second electrode.

[0020] Optionally, the coil assembly includes an iron core, a coil bobbin sleeved on the iron core, and a coil wound on the coil bobbin;

[0021] The coil bobbin is fixedly connected to the outer side wall of the pipeline.

[0022] Optionally, the pipeline and the measurement electrodes each include a plurality. The plurality of pipelines are arranged substantially in parallel, the plurality of measurement electrodes are correspondingly matched with the plurality of pipelines, and the first electrodes of the plurality of measurement electrodes are arranged opposite to each other in two rows;

[0023] The electromagnetic flowmeter includes a main water inlet, and the main water inlet is respectively communicated with the plurality of pipelines at the open end of the bracket.

[0024] Optionally, there are four pipelines and two coil assemblies. One coil assembly is arranged between one group of two adjacent pipelines, and the other coil assembly is arranged between another group of two adjacent pipelines; the two coil assemblies are coaxially arranged.

[0025] Optionally, the four signal acquisition boards corresponding to one row of the first electrodes are integrally formed into a first signal acquisition board;

[0026] Among the four signal acquisition boards corresponding to the other row of the first electrodes, two of them are integrally formed into a second signal acquisition board and a third signal acquisition board respectively;

[0027] The first signal acquisition board is parallel to the second signal acquisition board and the third signal acquisition board, and the first signal acquisition board is arranged opposite to the second signal acquisition board and the third signal acquisition board, and the second signal acquisition board and the third signal acquisition board are located on the same plane.

[0028] Optionally, the electromagnetic flowmeter further includes a main circuit board and two parallel signal lines;

[0029] The main circuit board is arranged on one side of the first signal acquisition board, and electrical connection parts are arranged at positions on the main circuit board facing the second signal acquisition board and the third signal acquisition board. Electrical cooperation parts are arranged at corresponding positions of the first signal acquisition board. The electrical connection parts are connected to the electrical cooperation parts to realize the electrical connection between the first signal acquisition board and the main circuit board;

[0030] Both ends of one of the signal lines are respectively connected to the same side of the first signal acquisition board and the second signal acquisition board to realize the electrical connection between the first signal acquisition board and the second signal acquisition board;

[0031] Both ends of the other signal line are respectively connected to the same side of the first signal acquisition board and the third signal acquisition board to realize the electrical connection between the first signal acquisition board and the third signal acquisition board;

[0032] The main circuit board is used to obtain the flow rate and / or velocity of the liquid in the four pipelines according to the signals collected by the first signal acquisition board, the second signal acquisition board and the third signal acquisition board.

[0033] According to a second aspect of the present invention, an agricultural plant protection machine is provided. The agricultural plant protection machine includes a frame, a water tank, a water distributor, the electromagnetic flowmeter described in any one of the above, a pump device, and a nozzle. Among them, the water tank and the nozzle are installed on the frame. The water inlet of the water distributor is communicated with the water outlet of the water tank. The water outlet of the water distributor is communicated with the water inlet of the pump device through the electromagnetic flowmeter. The water outlet of the pump device is communicated with the nozzle.

[0034] According to the technical solution provided by the embodiment of the present invention, multiple measuring electrodes are correspondingly matched with multiple pipelines to realize the measurement of the flow rate and / or flow velocity of the liquid in multiple pipelines at the same time. The electromagnetic flowmeter of the present invention realizes the function of the water distributor.

[0035] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0037] Figure 1 is a cross-sectional schematic view of the electromagnetic flowmeter in an embodiment of the present invention;

[0038] Figure 2 is a cross-sectional schematic view of the electromagnetic flowmeter in another embodiment of the present invention;

[0039] Figure 3 is a cross-sectional schematic view of the electromagnetic flowmeter in another embodiment of the present invention;

[0040] Figure 4 is a three-dimensional schematic view of the electromagnetic flowmeter in an embodiment of the present invention;

[0041] Figure 5 is a cross-sectional schematic view of the electromagnetic flowmeter in another embodiment of the present invention;

[0042] Figure 6 is a cross-sectional schematic view of the electromagnetic flowmeter in another embodiment of the present invention;

[0043] Figure 7 is a split schematic view of a part of the structure of the electromagnetic flowmeter in an embodiment of the present invention;

[0044] Figure 8 is a split schematic view of another part of the structure of the electromagnetic flowmeter in an embodiment of the present invention;

[0045] Figure 9 is a three-dimensional schematic view of the electromagnetic flowmeter in another embodiment of the present invention;

[0046] Figure 10 It is a schematic diagram of the structural disassembly of an agricultural plant protection machine in another embodiment of the present invention;

[0047] Figure 11 It is a three-dimensional schematic diagram of an agricultural plant protection machine in another embodiment of the present invention;

[0048] Figure 12 It is a three-dimensional schematic diagram of the agricultural plant protection machine in another direction in another embodiment of the present invention.

[0049] Reference numerals:

[0050] 100: Frame;

[0051] 200: Water tank; 201: Box body; 2011: Groove; 202: Main pipeline; 2021: First water outlet;

[0052] 300: Water distributor;

[0053] 400: Electromagnetic flowmeter; 401: Bracket; 402: Pipeline; 4021: Electrode mounting surface; 403: Measuring electrode; 404: Coil assembly; 4041: Iron core; 4042: Coil holder; 4043: Coil; 405: Signal acquisition board; 4051: First signal acquisition board; 4052: Second signal acquisition board; 4053: Third signal acquisition board; 406: Fastener; 407: Quick-release connector; 408: Second electrode; 409: Main water inlet; 410: Main circuit board; 4101: Electrical connection part; 4102: Coil socket; 4103: External interface; 411: Signal line; 412: Shock-absorbing structure; 413: Reinforcing plate; 414: Outer shell; 415: Cover; 416: Water distribution cavity; 417: Flow guiding structure; 418: Transition surface; 419: Sealing structure;

[0054] 500: Pump device;

[0055] 600: Quick-release fixing part; 601: Fastening nut; 602: Flange nut;

[0056] 700: Branch pipeline;

[0057] 800: Washer;

[0058] 900: Sealing ring;

[0059] 1000: Fixing part. Detailed implementation manners

[0060] Exemplary embodiments will be described in detail herein, and examples thereof are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0061] The terms used in the present invention are for the purpose of describing particular embodiments only and are not intended to limit the present invention. The singular forms "a", "the", and "said" used in the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0062] It should be understood that although the terms first, second, third, etc. may be used in the present invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0063] It should be noted that, without conflict, the features in the following embodiments and implementation manners may be combined with each other.

[0064] Please refer to Figures 1 to 6 , an embodiment of the present invention provides an electromagnetic flowmeter, and the electromagnetic flowmeter 400 may include a bracket 401, a pipeline 402, measuring electrodes 403, a coil assembly 404, and a signal acquisition board 405. Among them, one end of the pipeline 402 is provided on the bracket 401, and the opening end of the pipeline 402 close to the bracket 401 exposes outside the bracket 401. The pipeline 402 in this embodiment is used for a liquid (such as when the electromagnetic flowmeter 400 is applied to an agricultural plant protection machine, the liquid may be water or liquid pesticide) to flow through.

[0065] The measuring electrode 403 cooperates with the pipeline 402. The measuring electrode 403 in this embodiment includes two first electrodes. The two first electrodes are oppositely arranged on both sides of the outer sidewall of the pipeline 402. After the detection ends of the two first electrodes pass through the sidewall of the pipeline 402 respectively, they can contact the liquid flowing through the pipeline 402. Moreover, the detection ends of the two first electrodes are oppositely arranged, that is, the connection line of the detection ends of the two first electrodes is orthogonal to the flow direction of the liquid in the pipeline 402. In this embodiment, the pipeline 402 includes two oppositely arranged planar electrode mounting surfaces 4021. First electrode mounting holes are formed on the electrode mounting surfaces 4021. The detection ends of the first electrodes respectively pass through the first electrode mounting holes, and the end surfaces of the detection ends of the first electrodes are substantially flush with the inner sidewall of the pipeline 402. It should be noted that in the embodiments of the present invention, being substantially flush means that within the allowable error range, it is considered that the end surfaces of the detection ends of the first electrodes and the inner sidewall of the pipeline 402 are coplanar.

[0066] Furthermore, the coil assembly 404 is used to generate an electromagnetic field, and the coil assembly 404 is arranged on one side of the outer sidewall of the pipeline 402. In this embodiment, the axial direction of the coil assembly 404 is orthogonal to the connection line of the detection ends of the two first electrodes, that is, the flow direction of the liquid in the pipeline 402 in this embodiment, the axial direction of the coil assembly 404, and the connection line of the detection ends of the two first electrodes are orthogonal to each other, meeting the requirements of electromagnetic induction detection. In this embodiment, the coil assembly 404 is used to generate an electromagnetic field, and this electromagnetic field is an alternating magnetic field. The electromagnetic field generated by the coil assembly 404 can pass through the pipeline 402 and enter the pipeline 402. When the flow rate of the liquid flowing through the pipeline 402 changes, under the action of the electromagnetic field, the difference in the induced electromotive forces of the two first electrodes will also change accordingly. Moreover, the two signal acquisition boards 405 are arranged on the same side of the outer sidewall of the pipeline 402 corresponding to the two first electrodes, and the signal acquisition board 405 is electrically coupled to the first electrode on the corresponding side. The signal acquisition board 405 in this embodiment is used to acquire the signals of the first electrode on the corresponding side.

[0067] In the electromagnetic flowmeter 400 according to the embodiment of the present invention, by designing the electrode mounting surface 4021 on the pipeline 402 as a planar shape, when the first electrode (i.e., the detection electrode) is installed in the first electrode mounting hole on the electrode mounting surface 4021, the end surface of the detection end of the first electrode is substantially flush with the inner sidewall of the pipeline 402, ensuring the continuity of the flow field and improving the measurement accuracy; at the same time, preventing fouling makes the cleaning and maintenance of the flowmeter more convenient.

[0068] The flow rate and / or rate of the liquid flowing through the pipeline 402 can be obtained according to the signals collected by the two signal acquisition boards 405. Optionally, the calculation formula for the flow rate Q of the liquid flowing through the pipeline 402 is as follows:

[0069]

[0070] In Formula (1), B is the magnetic field strength; U is the induced electromotive force generated by the two first electrodes; A is the cross-sectional area of the pipeline 402; d is the distance between the two electrode mounting surfaces 4021 on the pipeline 402 for mounting the two first electrodes; k is a correction coefficient, and the magnitude of k can be set by considering factors such as the liquid rate in the pipeline 402 and the fact that the magnetic field strength is not uniform, so as to reduce the error between the flow rate Q of the liquid flowing through the pipeline 402 obtained by calculating according to Formula (1) and the actual flow rate of the liquid flowing through the pipeline 402.

[0071] Optionally, k is approximately 0.8. For example, k can be 0.8 ± 0.05. For an electromagnetic flowmeter 400 with specific dimensions and for specific working conditions, the volumetric method (the volume of the liquid flowing through the pipeline 402 within a certain time) can be used to calibrate the magnitude of k.

[0072] After calculating the flow rate Q of the liquid flowing through the pipeline 402 according to Formula (1), the rate of the liquid flowing through the pipeline 402 can be calculated based on the flow rate Q of the liquid flowing through the pipeline 402.

[0073] Optionally, the bracket 401 is made of plastic material, which can reduce the weight of the electromagnetic flowmeter 400. Of course, the material of the bracket 401 is not limited to plastic, and other materials with lighter texture can also be selected.

[0074] The pipeline 402 in this embodiment can be a straight pipeline or a curved pipeline. In addition, the pipeline 402 can be made of plastic material, which is convenient for the magnetic field to penetrate and can also reduce the weight of the electromagnetic flowmeter 400. Of course, the material of the pipeline 402 is not limited to plastic, and other materials with lighter texture and convenient for magnetic field penetration can also be selected. It can be understood that the material of the pipeline 402 and the material of the bracket 401 can be the same or different. In addition, the pipeline 402 and the bracket 401 can be integrally formed; of course, the pipeline 402 and the bracket 401 can also be independent structures.

[0075] Optionally, the flow channel cross-section of the pipeline 402 is a regular polygon, such as a square or other regular polygon. Among them, the electrode mounting surface 4021 is two opposite and parallel side walls on the pipeline 402.

[0076] Since the first electrode needs to extend into the liquid in the pipeline 402, the problem of waterproofing needs to be considered. To prevent the liquid in the pipeline 402 from leaking from the first electrode mounting hole and entering the signal acquisition board 405, the existing method is to use a sealing ring sleeved on the detection electrode to achieve waterproofing, and the detection electrode is fixed on the pipeline 402 through the electrode fixing screw. In this embodiment, the first electrode mounting hole communicates with the flow channel of the pipeline 402, and the first electrode is integrally formed in the first electrode mounting hole. By integrally forming the first electrode in the first electrode mounting hole, the fixed connection between the first electrode and the pipeline 402 is realized, the liquid in the pipeline 402 will not leak from the first electrode mounting hole, and at the same time, the step of installing the first electrode in the first electrode mounting hole is omitted, and the existing sealing ring and electrode fixing screw are saved, thereby reducing the cost and the installation difficulty. Optionally, the first electrode is embedded in the first electrode mounting hole by in-mold injection, that is, the first electrode is integrally formed in the first electrode mounting hole by in-mold injection; it should be understood that other processes or methods can also be used to integrally form the first electrode in the first electrode mounting hole.

[0077] To enable the two first electrodes to better generate the induced electromotive force, the two first electrodes are coaxially arranged, that is, the detection ends of the two first electrodes face each other; and, the axial directions of the two first electrodes are perpendicular to the axial direction of the coil assembly 404, realizing the orthogonality of the flow direction of the liquid in the pipeline 402, the axial direction of the coil assembly 404, and the axial directions of the two first electrodes, so as to meet the electromagnetic induction detection requirements. By adopting the arrangement mode of the first electrode and the coil assembly 404 in this embodiment, the structure of the electromagnetic flowmeter 400 is more compact, thereby reducing the volume of the electromagnetic flowmeter 400. For example, the extending direction of the pipeline 402 is the left-right direction, that is, the flow direction of the liquid in the pipeline 402 is the left-right direction, and the two first electrodes are coaxially arranged on the upper and lower sides of the pipeline 402, and the axial direction of the coil assembly 404 coincides with the front-back direction of the pipeline 402.

[0078] The signal acquisition board 405 in this embodiment can be made of plastic material or other materials with lighter texture to reduce the weight of the electromagnetic flowmeter 400.

[0079] The signal acquisition board 405 and the first electrode on the corresponding side can be electrically coupled and connected by a direct contact method. For example, in some embodiments, the signal acquisition board 405 is provided with through holes (not marked), and the signal acquisition board 405 is sleeved on the tail end of the first electrode through the through holes to achieve electrical connection between the signal acquisition board 405 and the first electrode. In this embodiment, by providing through holes on the signal acquisition board 405, electrical plug-in connection between the signal acquisition board 405 and the tail end of the first electrode is achieved, thereby realizing electrical connection between the signal acquisition board 405 and the first electrode. At the same time, the electrical plug-in connection method is beneficial to the stable transmission of signals. It should be understood that in some other embodiments, other direct contact methods (such as the end face of the tail end of the signal acquisition board 405 directly abutting against the first electrode) can also be used to achieve electrical connection between the signal acquisition board 405 and the first electrode. Among them, the tail end of the first electrode and the detection end of the first electrode are located at both ends of the first electrode.

[0080] The signal acquisition board 405 and the first electrode on the corresponding side can be electrically coupled and connected by an indirect connection method. For example, the signal acquisition board 405 and the first electrode are connected through a conductive connector. One end of the conductive connector is connected to the signal acquisition board 405 to achieve electrical connection between the conductive connector and the signal acquisition board 405, and the other end of the conductive connector is connected to the tail end of the first electrode to achieve electrical connection between the conductive connector and the first electrode. Optionally, the signal acquisition board 405 is provided with a first conductive hole, and the tail end of the first electrode is provided with a second conductive hole. One end of the conductive connector is electrically matched with the first conductive hole, and the other end of the conductive connector is matched with the second conductive hole.

[0081] Please refer to Figure 2 , in some embodiments, the signal acquisition board 405 is installed on the tail of the first electrode through a fastener 406. The signal acquisition board 405 is stably connected to the first electrode through the fastener 406, so that the electrical connection between the signal acquisition board 405 and the first electrode is more stable, which is beneficial to the stable transmission of signals between the signal acquisition board 405 and the first electrode. The type of the fastener 406 can be selected according to needs. In this embodiment, the fastener 406 includes at least one of the following: threaded fasteners, buckles. Among them, the threaded fastener can be a screw or a bolt. It can be understood that the type of the fastener 406 is not limited to this, and it can also be other quick-release structures.

[0082] Please refer to Figure 3, in some embodiments, the signal acquisition board 405 is mounted on the side wall of the pipeline 402 through a quick-release connector 407. The signal acquisition board 405 is stably connected to the outer side wall of the pipeline 402 through the quick-release connector 407, so that the electrical connection between the signal acquisition board 405 and the first electrode is more stable, which is beneficial to the stable transmission of signals between the signal acquisition board 405 and the first electrode. The type of the quick-release connector 407 can be selected according to needs. The quick-release connector 407 in this embodiment may include at least one of the following: threaded fasteners, snap fasteners. Among them, the threaded fasteners can be screws or bolts. It can be understood that the type of the quick-release connector 407 is not limited to this, and it can also be other quick-release structures.

[0083] It should be understood that the two embodiments of mounting the signal acquisition board 405 on the tail of the first electrode through fasteners and mounting the signal acquisition board 405 on the side wall of the pipeline 402 through the quick-release connector 407 can be combined, so that the electrical connection between the signal acquisition board 405 and the first electrode is more stable, which is beneficial to the stable transmission of signals between the signal acquisition board 405 and the first electrode.

[0084] In addition, the signal acquisition board 405 can be in contact with the first electrode to increase the compactness of the structure, which is beneficial to the miniaturized design of the electromagnetic flowmeter 400.

[0085] Since the signals detected by the two first electrodes are differential signals, the electromagnetic flowmeter 400 needs a potential reference point. In this embodiment, please refer to again Figures 1 to 6, the electromagnetic flowmeter 400 may further include two second electrodes 408, which are respectively disposed at two open ends of the pipeline 402, and the two second electrodes 408 are disposed on both sides of one of the first electrodes. After the heads of the two second electrodes 408 pass through the side wall of the pipeline 402 respectively, they can contact the liquid flowing through the pipeline 402. A second electrode 408 mounting hole is formed on one of the electrode mounting surfaces 4021. The head of the second electrode 408 passes through the second electrode 408 mounting hole, and the end face of the head of the second electrode 408 is substantially flush with the inner side wall of the pipeline 402. Further, the tails of the two second electrodes 408 are in contact with the signal acquisition board 405 on the corresponding side to be grounded. By grounding the second electrode 408, the signal acquisition board 405 is connected to the liquid in the pipeline 402, and the grounding point is used as the potential reference point of the electromagnetic flowmeter 400 to achieve accurate detection of the flow rate and / or flow velocity. It should be noted that in the embodiment of the present invention, one of the two open ends of the pipeline 402 is used as the water inlet of the pipeline 402, and the other open end is used as the water outlet of the pipeline 402. By respectively arranging the second electrodes 408 at the water inlet and the water outlet of the pipeline 402, the liquids in the water inlet and the water outlet of the pipeline 402 are respectively grounded, and the circulation of the current is realized. The grounding path includes: the liquid in the water inlet of the pipeline 402 -> the corresponding second electrode 408 -> the signal acquisition board 405, the liquid in the water outlet of the pipeline 402 -> the corresponding second electrode 408 -> the signal acquisition board 405.

[0086] In this embodiment, the second electrode 408 mounting hole communicates with the flow channel of the pipeline 402, and the second electrode 408 is integrally formed in the second electrode 408 mounting hole. By integrally forming the second electrode 408 in the second electrode 408 mounting hole, the fixed connection between the second electrode 408 and the pipeline 402 is realized, and the liquid in the pipeline 402 will not leak from the second electrode 408 mounting hole. At the same time, the step of installing the second electrode 408 in the second electrode 408 mounting hole is omitted, and it is not necessary to use a sealing ring to seal the second electrode 408, nor is it necessary to use an electrode fixing screw to fix the second electrode 408, thereby reducing the cost and the installation difficulty. Optionally, the second electrode 408 is embedded in the second electrode 408 mounting hole by in-mold injection, that is, the second electrode 408 is integrally formed in the second electrode 408 mounting hole by in-mold injection; it should be understood that other processes or methods can also be used to integrally form the second electrode 408 in the second electrode 408 mounting hole.

[0087] In this embodiment, a grounding hole is provided at the position of the signal acquisition board 405 corresponding to the second electrode 408, and the tail of the second electrode 408 cooperates with the grounding hole to realize the grounding of the second electrode 408. In this embodiment, by providing a grounding hole on the signal acquisition board 405, the grounding of the second electrode 408 is realized.

[0088] Further, please refer to Figure 2 , in some embodiments, the signal acquisition board 405 is mounted on the tail of the second electrode 408 through a fastener 406. The signal acquisition board 405 is stably connected to the second electrode 408 through the fastener 406 to ensure that the second electrode 408 is always grounded. The type of the fastener 406 can be selected according to needs. In this embodiment, the fastener 406 includes at least one of the following: a threaded fastener, a snap fastener. Among them, the threaded fastener can be a screw or a bolt. It can be understood that the type of the fastener 406 is not limited to this, and it can also be other quick-release structures.

[0089] The first electrode and the second electrode 408 in this embodiment are both metal electrodes.

[0090] Please refer to Figure 5 , the coil assembly 404 may include an iron core 4041, a bobbin 4042 sleeved on the iron core 4041, and a coil 4043 wound around the bobbin 4042. Among them, the iron core 4041 can constrain the magnetic field direction and reduce magnetic leakage. The bobbin 4042 in this embodiment is fixedly connected to the outer side wall of the pipeline 402. The bobbin 4042 and the outer side wall of the pipeline 402 cooperate to form a closed receiving space, and the iron core 4041 is received in the receiving space, so that the electromagnetic field is sealed in the receiving space through the bobbin 4042 and the pipeline 402. Optionally, the bobbin 4042 is a metal frame, such as an iron frame or a steel frame, etc. The metal frame can block the electromagnetic field generated by the coil assembly 404 and seal the electromagnetic field in the receiving space.

[0091] The pipeline 402 in this embodiment may include one, two, three, four or more than four, so as to realize the measurement of the liquid flow rate and / or flow velocity of a single channel, two channels, three channels, four channels or more than four channels.

[0092] Please refer to Figures 4 to 9 , the pipeline 402 and the measurement electrodes 403 each include a plurality. The plurality of pipelines 402 are arranged substantially in parallel. The plurality of measurement electrodes 403 are correspondingly matched with the plurality of pipelines 402. Among them, the implementation process of the measurement electrode 403 cooperating with the pipeline 402 to measure the liquid flow rate and / or flow velocity in the pipeline 402 can refer to the description of the corresponding part of the above embodiment, which will not be elaborated here. It should be noted that in the embodiments of the present invention, substantially parallel means that within the allowable angular error range, it is considered that the plurality of pipelines 402 are parallel to each other.

[0093] In this embodiment, the first electrodes of the multiple measurement electrodes 403 are arranged in two rows opposite to each other. For example, if the extending direction of the pipeline 402 is the left-right direction, one of the two first electrodes corresponding to each pipeline 402 is arranged at the bottom of the pipeline 402, and the other is arranged at the top of the pipeline 402. Further, the electromagnetic flowmeter 400 may further include a main water inlet 409, and the main water inlet 409 is respectively communicated with the open ends of the multiple pipelines 402 provided on the bracket 401. The electromagnetic flowmeter 400 in this embodiment also realizes the function of a water distributor. If the electromagnetic flowmeter 400 is applied to an agricultural plant protection machine, the main water inlet 409 can be communicated with the water outlet of the water tank 200 of the agricultural plant protection machine. The liquid in the water tank 200 flows into the main water inlet 409 through the water outlet of the water tank 200, and then flows into the corresponding pipeline 402 through the open ends of the pipelines 402 provided on the bracket 401, realizing the function of a water distributor.

[0094] Correspondingly, second electrodes 408 are respectively provided at the two open ends of each pipeline 402. The manner in which the second electrodes 408 cooperate with the pipeline 402 can refer to the description of the corresponding part of the above embodiment, and will not be elaborated here.

[0095] In the following embodiment, taking the pipeline 402 including four as an example, the structure of the electromagnetic flowmeter 400 in this embodiment will be described in detail.

[0096] Please refer to Figure 5 and Figure 6 , the coil assembly 404 in this embodiment may include two. One coil assembly 404 is arranged between one group of two adjacent pipelines 402, and the other coil assembly 404 is arranged between another group of two adjacent pipelines 402. In this embodiment, the magnetic field direction is perpendicular to the liquid direction. The two groups of coils are symmetrically arranged in the middle of the four pipelines 402 to ensure that the magnetic field intensity at the centers of the four pipelines 402 is as consistent as possible, ensuring the measurement accuracy. It should be noted that in the embodiment of the present invention, the magnetic field intensity at the centers of the two middle pipelines 402 among the four pipelines 402 is slightly greater than the magnetic field intensity at the centers of the two outer pipelines 402. The correction coefficient k in formula (1) can be adjusted according to the difference in the magnetic field intensity to eliminate the influence of the magnetic field intensity difference and improve the detection accuracy of the liquid flow rate in each pipeline 402.

[0097] The coil assembly 404 is clamped between two adjacent pipelines 402, and the two ends of the coil frame 4042 of the coil assembly 404 are respectively hermetically connected to the outer side walls of the corresponding pipelines 402 on the corresponding sides, so that the coil frame 4042 and the outer side walls of the two pipelines 402 on its two sides cooperate to form a closed receiving space, so as to seal the electromagnetic field in the receiving space through the coil frame 4042 and the pipeline 402.

[0098] In this embodiment, the two coil assemblies 404 are coaxially arranged, and the axial direction of the two coil assemblies 404 is perpendicular to the axial direction of the two first electrodes corresponding to each pipeline 402. The axes of the two coil assemblies 404 are also perpendicular to the center line of the pipeline 402. By adopting the arrangement mode of the second electrode 408 and the coil assembly 404 in this embodiment, the structure of the electromagnetic flowmeter 400 is more compact, thereby reducing the volume of the electromagnetic flowmeter 400.

[0099] For the two rows of first electrodes on the four pipelines 402, four signal acquisition boards 405 corresponding to one row of first electrodes are integrally formed into a first signal acquisition board 4051, and two of the four signal acquisition boards 405 corresponding to the other row of first electrodes are integrally formed into a second signal acquisition board 4052 and a third signal acquisition board 4053 respectively. When the first signal acquisition board 4051, the second signal acquisition board 4052, and the third signal acquisition board 4053 are installed on the pipeline 402, the first signal acquisition board 4051 is parallel to the second signal acquisition board 4052 and the third signal acquisition board 4053, and the first signal acquisition board 4051 is disposed opposite to the second signal acquisition board 4052 and the third signal acquisition board 4053. The second signal acquisition board 4052 and the third signal acquisition board 4053 are located on the same plane. This structural design method facilitates the fixation between structures.

[0100] Further, please refer to Figures 6 to 8 , the electromagnetic flowmeter 400 further includes a main circuit board 410 and two signal lines 411. The main circuit board 410 is disposed on one side of the first signal acquisition board 4051. And at a position on the main circuit board 410 facing the second signal acquisition board 4052 and the third signal acquisition board 4053, an electrical connection portion 4101 is provided. At the corresponding position of the first signal acquisition board 4051, an electrical cooperation portion is provided. The electrical connection portion 4101 is connected to the electrical cooperation portion to realize the electrical connection between the first signal acquisition board 4051 and the main circuit board 410. Both ends of one signal line 411 are respectively connected to the same side of the first signal acquisition board 4051 and the second signal acquisition board 4052 to realize the electrical connection between the first signal acquisition board 4051 and the second signal acquisition board 4052. Both ends of the other signal line 411 are respectively connected to the same side of the first signal acquisition board 4051 and the third signal acquisition board 4053 to realize the electrical connection between the first signal acquisition board 4051 and the third signal acquisition board 4053. And the two signal lines 411 are substantially parallel. Optionally, the main circuit board 410 is used to obtain the flow rate and / or rate of the liquid in the four pipelines 402 according to the signals collected by the first signal acquisition board 4051, the second signal acquisition board 4052, and the third signal acquisition board 4053.

[0101] In this embodiment, the detection circuit is arranged on the signal acquisition board 405 where the signals are relatively weak, while the power supply signal and the processing circuit are arranged on the main circuit board 410 where the signals are relatively strong, thus avoiding the interference of strong signals on weak signals and ensuring the detection accuracy. At the same time, the electrical connection part 4101 and the electrical cooperation part are arranged at the directly opposite positions in the middle of the second signal acquisition board 4052 and the third signal acquisition board 4053, ensuring that the detection loop lengths of the four pipes 402 are not much different and improving the detection accuracy.

[0102] In addition, the main circuit board 410 of this embodiment can supply power to the first signal acquisition board 4051, the second signal acquisition board 4052, the third signal acquisition board 4053, the coil assembly 404, etc., and can perform operations such as signal calculation and amplification.

[0103] Furthermore, please refer to Figure 7 , the main circuit board 410 may further include a coil socket 4102 for electrically coupling connection with the coil assembly 404 to energize the coil assembly 404 through the main circuit board 410.

[0104] Please refer to Figure 7 again. The main circuit board 410 is also provided with an external interface 4103 for electrically connecting with an external device to realize the electrical connection between the electromagnetic flowmeter 400 and the external device. Optionally, after calculating the flow rate and / or velocity of the liquid in the four pipes 402, the main circuit board 410 sends the flow rate and / or velocity of the liquid in the four pipes 402 to the external device through the external interface 4103. Optionally, the main circuit board 410 acquires the signals collected by the first signal acquisition board 4051, the second signal acquisition board 4052, and the third signal acquisition board 4053 respectively and amplifies them. Moreover, the main circuit board 410 also sends the amplified signals to the external device, and the external device calculates the flow rate and / or velocity of the liquid in the four pipes 402 according to the amplified signals.

[0105] Due to structural limitations, signal lines pass through the electromagnetic field, which results in closed conductor loops in the electromagnetic field. Since the electromagnetic field in the electromagnetic flowmeter is an alternating magnetic field, if the plane formed by the conductor loop is not parallel to the magnetic field direction, an induced electromotive force will be generated under the influence of the changing magnetic field, interfering with the measurement signal. This kind of interference is called differential interference. The existence of differential interference affects the stability of the flow velocity signal and reduces the measurement accuracy. For a long time, there has been a lack of effective solutions in the industry. Methods such as manual adjustment and software avoidance cannot solve this problem very well. Currently, most electromagnetic flowmeters design a mechanical structure to finely adjust the position of the signal line. After the electromagnetic flowmeter is assembled, the differential interference signal is observed manually, and the mechanical structure is manually finely adjusted to reduce the interference signal. This method is inefficient, and it is difficult to accurately evaluate the adjustment effect. It is not suitable for large-scale use in mass-produced products. Manual fine adjustment can only be used in the manufacture of small-batch customized flowmeters. This solution cannot be mass-produced on a large scale, cannot ensure the consistency of products, and cannot measure the effectiveness of adjustment with objective indicators. The software avoidance method sets an accurate sampling time to avoid the signal time with interference. This method will shorten the sampling time of the effective signal. For high-frequency excitation scenarios, if interference cannot be effectively suppressed, the upper limit of the excitation frequency will be restricted. Especially for micro and small electromagnetic flowmeters, when the signal is weak, if the interference is too large, it will seriously affect signal measurement.

[0106] For this, in the embodiment of the present invention, by adjusting the orientation of the signal line, the projection area of the conductor loop formed by the signal line in the direction of the electromagnetic field is reduced as much as possible, the differential interference is suppressed within a reasonable range to reduce the interference degree, and the differences between individuals are effectively controlled to ensure that the differences of the assembled flowmeters are small.

[0107] The arrangement direction of the signal line 411 intersects with the axis of the coil assembly 404, and the signal line 411 is arranged around the outer sides of the four pipes 402. One signal line 411 and the first signal acquisition board 4051 and the second signal acquisition board 4052 form a structure similar to a "gate" shape, and the other signal line 411 and the first signal acquisition board 4051 and the third signal acquisition board 4053 also form a structure similar to a "gate" shape. It should be noted that in the embodiment of the present invention, the arrangement direction of the signal line 411 refers to the extension direction of the two connection ends of the signal line 411 for connecting the two signal acquisition boards 405. Through the reasonable design of the structural limitation between the signal line 411 and the two signal acquisition boards 405 in the embodiment of the present invention, the projection area of the conductor loop formed by the signal line 411 in the direction of the electromagnetic field is reduced as much as possible, the influence of differential interference on the signal can be eliminated, the measurement accuracy of the electromagnetic flowmeter 400 can be improved, the differences between individuals can be effectively controlled, and the differences of the assembled flowmeters can be ensured to be small, making the signal consistency of the electromagnetic flowmeter 400 better.

[0108] Further optionally, a shock-absorbing structure 412 is provided between the signal line 411 and the pipeline 402 to prevent electromagnetic interference caused by the vibration of the signal line 411. The shock-absorbing structure 412 may include shock-absorbing foam or may also include a structure made of other materials capable of shock absorption.

[0109] Optionally, the pipeline 402 is a straight pipeline, and the signal line 411 is arranged substantially perpendicular to the extension direction of the pipeline 402. Since the axis of the coil assembly 404 is perpendicular to the extension direction of the pipeline 402, the central axis of the signal line 411 is also perpendicular to the axis of the coil assembly 404. The projection of the conductor loop formed by the signal line 411 in the direction of the electromagnetic field is a point. Therefore, this structural design method can minimize the projection area of the conductor loop formed by the signal line 411 in the direction of the electromagnetic field, thereby maximizing the elimination of the influence of differential interference on the signal and improving the measurement accuracy of the electromagnetic flowmeter 400. It can be understood that the signal line 411 being substantially perpendicular to the extension direction of the pipeline 402 means that the angle between the signal line 411 and the extension direction of the pipeline 402 is 90° ± error value, that is, within the allowable error range, it can be considered that the signal line 411 is substantially perpendicular to the extension direction of the pipeline 402.

[0110] Optionally, the two first electrodes of each measurement electrode 403 are coaxially arranged, and the central axis of the signal line 411 is arranged coplanarly with the central axis of the first electrode. Since the axis of the coil assembly 404 is perpendicular to the central axis of the first electrode, the central axis of the signal line 411 is also perpendicular to the axis of the coil assembly 404. The projection of the conductor loop formed by the signal line 411 in the direction of the electromagnetic field is a point. Therefore, this structural design method can minimize the projection area of the conductor loop formed by the signal line 411 in the direction of the electromagnetic field, thereby maximizing the elimination of the influence of differential interference on the signal and improving the measurement accuracy of the electromagnetic flowmeter 400.

[0111] Optionally, the signal line 411 has a preset width and a preset length. The width direction of the signal line 411 is parallel to the extension direction of the pipeline 402. This layout method can also make the central axis of the signal line 411 perpendicular to the axis of the coil assembly 404, thereby maximizing the elimination of the influence of differential interference on the signal and improving the measurement accuracy of the electromagnetic flowmeter 400. It should be noted that in the embodiments of the present invention, the width of the signal line 411 refers to the width of the signal line 411 perpendicular to the arrangement direction of the signal line 411. Among them, the preset width can be determined according to the number of signal paths between the two signal acquisition boards 405.

[0112] Further optionally, the first signal acquisition board 4051, the second signal acquisition board 4052, and the third signal acquisition board 4053 are all square, and one signal line 411 is arranged along the symmetry axis of the side parts of the first signal acquisition board 4051 and the second signal acquisition board 4052; the other signal line 411 is arranged along the symmetry axis of the side parts of the first signal acquisition board 4051 and the third signal acquisition board 4053, so as to ensure that the axes of the two solenoid coil assemblies 404 pass through the signal line 411.

[0113] The above-mentioned wiring design of the signal line 411 ensures that the signal loop plane is parallel to the magnetic field direction, so that the signal loop will not be interfered by the alternating magnetic field.

[0114] The shape of the signal line 411 can be designed as needed. To increase the structural compactness and reduce the volume of the electromagnetic flowmeter 400, optionally, the signal line 411 is a sheet structure, and the signal line 411 is basically parallel to the side wall of the bracket 401.

[0115] The implementation manner of connecting the signal line 411 to the two signal acquisition boards 405 can be selected as needed. For example, in some embodiments, both ends of the signal line 411 are detachably connected to the corresponding signal acquisition boards 405 through electrical connectors to achieve the electrical coupling connection of the two signal acquisition boards 405.

[0116] In other embodiments, one end of the signal line 411 is integrally formed with one of the signal acquisition boards 405, and an electrical connector is provided at the other end of the signal line 411 for detachably connecting with the electrical connector of the other signal acquisition board 405. The signal line 411 is not easy to lose, and such a design will not cause trouble to the installation of the signal acquisition board 405 and reduces the weight of the electromagnetic flowmeter 400. It can be understood that the electrical connector of the signal line 411 and the electrical connector of the signal acquisition board 405 are a male head and a female head that cooperate with each other, and the cooperation of the male head and the female head can achieve the electrical coupling connection of the signal line 411 and the signal acquisition board 405.

[0117] The signal line 411 in this embodiment can be an FPC line. The FPC line is convenient to bend, so that it can more conveniently connect the signal acquisition boards 405 arranged oppositely on both sides of the bracket 401. It should be understood that the signal line 411 can also be other types of wires.

[0118] It can be understood that the layout methods of the signal line 411 in the above embodiments can be combined with each other.

[0119] Please refer to Figure 8 , reinforcing plates 413 are provided on both sides of the signal line 411 to improve the strength of the signal line 411 and extend the service life of the signal line 411.

[0120] In addition, in an alternative embodiment, two signal acquisition boards 405 are overlapped by a signal transmission circuit board to achieve signal transmission. The two signal acquisition boards 405 and the signal transmission board form a "gate"-shaped structure, thereby eliminating the influence of differential interference on the signal and improving the measurement accuracy of the electromagnetic flowmeter 400.

[0121] Please combine Figures 4 to 9 The electromagnetic flowmeter 400 may further include a housing 414, a main water inlet 409 is disposed on one side of the bracket 401, and the housing 414 is disposed on the other side of the bracket 401, and the housing 414 is fixedly connected to the bracket 401. The housing 414 cooperates with the bracket 401 to form a receiving cavity, and the opening end of the pipe 402 away from the bracket 401 is exposed outside the housing 414, and the portion of the pipe 402 located between the two opening ends is received in the receiving cavity. The measuring electrode 403, the coil assembly 404, the signal acquisition board 405, the second electrode 408, the main circuit board 410 and the signal line 411 are also received in the receiving cavity.

[0122] In the following embodiments, the pipeline 402 is referred to as a water distribution pipeline.

[0123] The embodiment of the present invention provides an airborne spraying system, which can be applied to an agricultural plant protection machine, such as a plant protection drone or other agricultural spraying devices. The agricultural plant protection machine of this embodiment includes a frame 100. Figures 10 to 12 The airborne spraying system may include a water tank 200, a water distributor 300, a flow meter, a pump device 500, a quick-release fixture 600, and a branch pipe 700. The water tank 200 includes a box body 201 and a main pipe 202. The box body 201 is used to be installed on the frame 100, and the main pipe 202 is arranged outside the box body 201. The box body 201 of this embodiment has a liquid storage cavity, which is used to store liquids such as water or pesticides. In addition, a groove 2011 is provided on one side of the box body 201, and the groove 2011 is close to the frame 100.

[0124] In this embodiment, the water distributor 300 is integrated on the flow meter to form the electromagnetic flow meter 400 of the above embodiment, which solves the problem of multiple pipes being divided into one. At the same time, there is no need to add a special water distributor module, and the structure is more compact.

[0125] Further, the main pipeline 202 includes a first water inlet (not shown) and a first water outlet 2021. The water distributor 300 is provided with a second water inlet (i.e., the main water inlet 409 in the above embodiment) and a plurality of second water outlets. The flowmeter is used to detect the flow rate and / or velocity of the liquid in each second water outlet. In this embodiment, the main pipeline 202, the water distributor 300, and the flowmeter are all housed in the groove 2011, and the main pipeline 202 is arranged along the side wall of the box body 201. The first water inlet is communicated with the liquid storage cavity, and the first water outlet 2021 is arranged at the top of the groove 2011. Moreover, the first water outlet 2021 is located between the water tank 200 and the frame 100. Further, the pump device 500 is used to be installed on the box body 201, and the pump device 500 is located at the bottom of the frame 100. The second water inlet of this embodiment is installed on the first water outlet 2021 through a quick-release fixing member 600, and the second water outlet is communicated with the water inlet of the pump device 500 through a branch pipeline 700.

[0126] In the airborne spraying system according to the embodiment of the present invention, by providing a groove 2011 on one side of the box body 201 of the water tank 200, the main pipeline 202, the water distributor 300, and the flowmeter of the water tank 200 are all housed in the groove 2011, and the main pipeline 202 is arranged along the side wall of the box body 201, which solves the problem of messy pipeline layout of the multi-channel spraying system and improves the compactness of the pipelines of the spraying system; at the same time, through the quick-release fixing member 600, the quick disassembly and assembly of the water distributor 300 and the main pipeline 202 are realized, which is convenient for the maintenance and replacement of the water distributor 300.

[0127] The two open ends of the water distribution pipeline are respectively a first open end and a second open end, and the first open end and the second open end are located at both ends of the water distribution pipeline. Moreover, the water distribution pipeline of this embodiment includes a water inlet end and a water outlet end, and one of the first open end and the second open end serves as the water inlet end, and the other serves as the water outlet end. The first open end is fixedly connected to the bracket 401, and the second open end is exposed outside the housing 414. Optionally, the part of the water distribution pipeline except the second open end is housed in the accommodation cavity jointly formed by the housing 414 and the bracket 401.

[0128] The electromagnetic flowmeter 400 further includes a cover body 415. The second water inlet is arranged on the cover body 415. The cover body and the bracket 401 enclose to form a water distribution cavity 416. The second water inlet, the first open end, and the water distribution cavity 416 are respectively communicated, and the second water outlet is the second open end.

[0129] In this embodiment, the liquid flow path includes: liquid storage cavity -> first water inlet -> flow channel of the main pipeline 202 -> first water outlet 2021 -> second water inlet -> water distribution cavity 416 -> first open end -> flow channel of the water distribution pipeline -> second open end (i.e., the second water outlet).

[0130] Please refer to againFigure 6 The electromagnetic flowmeter 400 further includes a flow guiding structure 417. A part of the flow guiding structure 417 is received in the accommodating cavity, and multiple water distribution pipes are respectively arranged on both sides of the flow guiding structure 417. The flow guiding structure 417 of this embodiment is provided with a flow guiding cone, which is received in the water distribution cavity 416 and is opposite to the second water inlet. After the liquid flows into the water distribution cavity 416 from the second water inlet, it is shunted by the flow guiding cone, so that the liquid is evenly distributed on both sides of the flow guiding cone. Optionally, the surface of the flow guiding cone is arc-shaped to reduce the impact force generated when the liquid passes through the surface of the flow guiding cone.

[0131] Optionally, the flow guiding structure 417 is an axisymmetric structure, and the central axis of the flow guiding structure 417 coincides with the center line of the second water inlet. Multiple water distribution pipes are symmetrically arranged on both sides of the flow guiding structure 417. For example, for four-channel shunting, two water distribution pipes are respectively arranged on both sides of the flow guiding structure 417, and the four water distribution pipes are symmetrically arranged along the central axis of the flow guiding structure 417, so that the liquid flow rates flowing into the four water distribution pipes are basically the same, realizing uniform shunting.

[0132] Please refer to again Figure 6 On the inner side wall of the first open end near the side of the flow guiding cone, there is a transition surface 418, so that the flow rates of the liquid flowing into the multiple water distribution pipes are basically the same, and finally the uniform spraying effect of the pump device 500 is realized. Optionally, the bending degree of the transition surface 418 at the first open end is proportional to the distance from the first open end to the flow guiding cone, that is, the closer the first open end is to the flow guiding cone, the smaller the bending degree of the transition surface 418 at the first open end, and the smaller the opening of the corresponding first open end; the farther the first open end is from the flow guiding cone, the greater the bending degree of the transition surface 418 at the first open end, and the larger the opening of the corresponding first open end, so that the flow rates of the liquid flowing into the multiple pipes tend to be consistent, solving the problem of uneven spraying.

[0133] The matching manner between the cover body 415 and the bracket 401 can be designed as needed. For example, in some embodiments, a clamping groove is provided at the edge of the cover body 415, and a clamping portion is provided at the corresponding position of the bracket 401. The clamping portion cooperates with the clamping groove to realize the cooperation between the cover body 415 and the bracket 401; of course, the matching manner between the cover body 415 and the bracket 401 is not limited to the clamping manner, and other matching manners can also be selected.

[0134] The matching manner between the housing 414 and the bracket 401 can also be designed as needed. For example, in some embodiments, the housing 414 is fixed on the bracket 401 through a quick-release structure, where the quick-release structure can include at least one of a threaded fastener and a buckle, and the threaded fastener can be a screw or a bolt; it should be understood that the type of the quick-release structure is not limited to this, and it can also be other.

[0135] Further, sealing structures 419, such as sealing rings, are respectively provided at the connection between the cover body 415 and the bracket 401, the connection between the outer shell 414 and the bracket 401, and the connection between the second open end and the outer shell 414 to achieve the waterproof function.

[0136] The structure of the quick-release fixing member 600 can be designed as required. Please refer to Figure 5 and Figure 6 again. The quick-release fixing member 600 may include a fastening nut 601. The fastening nut 601 is sleeved on the second water inlet. And the fastening nut 601 is provided with internal threads, and the outer side wall of the first water outlet is provided with external threads that cooperate with the internal threads.

[0137] Further, the quick-release fixing member 600 further includes a flange nut 602. The flange nut 602 is used to fix the fastening nut 601 on the outer side wall of the second water inlet. Specifically, the flange nut 602 is sleeved on the second water inlet, and one end of the flange nut 602 is received inside the fastening nut 601. The end of the flange nut 602 received inside the fastening nut 601 cooperates with the end of the first water outlet.

[0138] Furthermore, a washer 800 is provided between the end of the flange nut 602 received inside the fastening nut 601 and the end of the first water outlet. The washer 800 tightly fits the flange nut 602 and the first water outlet, thereby realizing the tight fit between the first water outlet and the fastening nut 601.

[0139] In addition, to prevent liquid leakage, a sealing ring 900 is provided between the end of the flange nut 602 away from the fastening nut 601 and the outer side wall of the second water inlet. The inner ring of the sealing ring 900 is sleeved on the outer side wall of the second water inlet, and the outer ring of the sealing ring 900 is hermetically connected to the inner side wall of the end of the flange nut 602 away from the fastening nut 601.

[0140] Please refer to Figure 10 again. The airborne spraying system may further include a fixing member 1000. The fixing member 1000 is used to install the second water outlet on the side wall of the groove 2011, thereby fixing the water divider on the box body 201. Specifically, the fixing member 1000 is provided with a sleeving portion and a fixing portion. Among them, the sleeving portion is sleeved on the second water outlet, and the fixing portion is detachably connected to the side wall of the groove 2011. Specifically, the fixing portion can be detachably connected to the side wall of the groove 2011 by means of threaded connection, snap connection, etc.

[0141] The direction of the pipeline between the flowmeter and the pump device 500 will inevitably turn multiple times. The general solution is to increase the elbows. However, one elbow means two interfaces and at least two nuts need to be screwed. When the number of the second water outlets and the pump device 500 is large, the number of nuts to be screwed is also large, and the operation is very complicated. In this embodiment, the branch pipeline 700 is a U-shaped pipe, that is, the branch pipeline 700 is directly integrally formed into a U-shaped pipe. One U-shaped pipe saves 2 elbow interfaces and at least 4 nuts. In this embodiment, one opening of the U-shaped pipe is communicated with the second water outlet, and the other opening is communicated with the water inlet of the pump device 500, so as to realize the connection between the flowmeter and the pump device 500.

[0142] Optionally, the pump device 500 is accommodated in the U-shaped groove of the U-shaped pipe to improve the structural compactness. Of course, to prevent the pump device 500 from colliding with the U-shaped pipe and causing the U-shaped pipe to be easily damaged, the pump device 500 may not be accommodated in the U-shaped groove of the U-shaped pipe. For example, please refer to Figure 12 and the U-shaped pipe is arranged below the pump device 500.

[0143] Since the U-shaped pipe cannot be demolded by conventional methods and cannot be processed by conventional injection molding processes, in this embodiment of the present invention, the blow molding process is used to process the U-shaped pipe, that is, the branch pipeline 700 in this embodiment of the present invention is a pipe integrally formed by blow molding.

[0144] In addition, the hardness of the material of the branch pipeline 700 is greater than a preset hardness threshold, which is convenient for processing into a U-shaped pipe.

[0145] In this embodiment, the number of the pump devices 500 may be equal to the number of the second water outlets, or the number of the pump devices 500 is less than the number of the second water outlets. In this embodiment, the number of the pump devices 500 is equal to the number of the second water outlets, and each second water outlet is communicated with the water inlet of the corresponding pump device 500 through a branch pipeline 700. In this embodiment, multiple pump devices 500 form a pump group, and the pump group is fixed on the box body 201.

[0146] It is worth mentioning that the electromagnetic flowmeter 400 in the above embodiment can be applied to an agricultural plant protection machine or other equipment with a liquid channel.

[0147] Please refer to Figures 10 to 12, embodiments of the present invention further provide an agricultural plant protection machine, which may include a frame 100, a water tank 200, a water distributor 300, the electromagnetic flowmeter 400 of the above embodiments, a pump device 500, and a nozzle. Among them, the water tank 200 and the nozzle are installed on the frame 100. The water inlet of the water distributor 300 is communicated with the water outlet of the water tank 200, and the water outlet of the water distributor 300 is communicated with the water inlet of the pump device 500 through the electromagnetic flowmeter 400. The water outlet of the pump device 500 is communicated with the nozzle. In this embodiment, the pipe 402 of the electromagnetic flowmeter 400 is exposed outside the bracket 401 near the open end of the bracket 401 and is communicated with the water outlet of the water distributor 300. The open end of the pipe 402 away from the bracket 401 is communicated with the water inlet of the pump device 500.

[0148] The number of nozzles is the same as the number of pump devices 500, and the nozzles are correspondingly communicated with the water outlets of the pump devices 500.

[0149] In this embodiment, the water distributor 300 is integrated on the electromagnetic flowmeter 400. Optionally, please refer to Figure 11 , the agricultural plant protection machine includes a plurality of pump devices 500. The plurality of pump devices 500 are communicated with the liquid storage cavity of the box body 201 through the main pipe 202, the electromagnetic flowmeter 400, and the branch pipe 700, and are communicated with the corresponding nozzles through the water outlet pipes. The liquid in the liquid storage cavity is sprayed after passing through the following flow path: the first water inlet of the main pipe 202 -> the flow path of the main pipe 202 -> the first water outlet 2021 -> the second water inlet -> the water distribution cavity 416 -> the first open end -> the flow path of the water distribution pipe -> the second open end -> the branch pipe 700 -> the water inlet of the pump device 500 -> the water outlet of the pump device 500 -> the water outlet pipe -> the nozzle, so as to spray liquid (pesticide, water) on the crops. Among them, the water distributor 300 evenly distributes the liquid to each pump device 500, and the plurality of pump devices 500 pump the liquid medicine to the corresponding nozzles.

[0150] The agricultural plant protection machine of this embodiment can be a plant protection unmanned aerial vehicle, or a pesticide spraying vehicle or a manual spraying device.

[0151] In this embodiment, the box body 201 is fixedly connected to the frame 100. Taking the plant protection unmanned aerial vehicle as an example, the frame 100 includes a fuselage and a landing gear connected to the bottom of the fuselage. The box body 201 is fixedly connected to the fuselage. The fixed connection method between the box body 201 and the fuselage can be any existing fixed method, such as threading, clamping, etc. In addition, the frame 100 may further include an arm connected to the fuselage, and the nozzle is provided at one end of the arm away from the fuselage.

[0152] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An electromagnetic flowmeter, characterized in that, The electromagnetic flowmeter includes: A bracket; A plurality of pipes, one end of each pipe is provided on the bracket, and the opening end of the pipe close to the bracket is exposed outside the bracket; A plurality of measuring electrodes, which cooperate with the pipes. The measuring electrodes include two first electrodes. The two first electrodes are oppositely arranged on both sides of the outer side wall of the pipe. After the detection ends of the two first electrodes respectively pass through the side wall of the pipe, they can contact the liquid flowing through the pipe, and the detection ends of the two first electrodes are oppositely arranged; A coil assembly for generating an electromagnetic field. The coil assembly is arranged on one side of the outer side wall of the pipe, and the axial direction of the coil assembly is orthogonal to the connection line of the detection ends of the two first electrodes; and Two signal acquisition boards, which are arranged on the same side of the outer side wall of the pipe corresponding to the two first electrodes, and the signal acquisition board is electrically coupled to the first electrode on the corresponding side for acquiring the signal of the first electrode on the corresponding side; Wherein, the electromagnetic flowmeter includes a main water inlet, and the main water inlet is respectively communicated with the opening ends of the plurality of pipes provided on the bracket; the plurality of pipes are arranged substantially in parallel, the plurality of measuring electrodes cooperate with the plurality of pipes correspondingly, and the first electrodes of the plurality of measuring electrodes are arranged in two rows oppositely.

2. The electromagnetic flowmeter according to claim 1, wherein The pipe includes two oppositely arranged planar electrode mounting surfaces, and first electrode mounting holes are formed on the electrode mounting surfaces. The detection ends of the first electrodes respectively pass through the first electrode mounting holes, and the end surfaces of the detection ends of the first electrodes are substantially flush with the inner side wall of the pipe. The connection line of the detection ends of the two first electrodes is orthogonal to the flow direction of the liquid in the pipe, and the flow channel cross-section of the pipe is a regular polygon.

3. The electromagnetic flowmeter according to claim 1, wherein The two first electrodes are coaxially arranged, and the axial direction of the two first electrodes is perpendicular to the axial direction of the coil assembly; Alternatively, the signal acquisition board is provided with a through hole, and the signal acquisition board is sleeved on the tail end of the first electrode through the through hole to realize the electrical connection between the signal acquisition board and the first electrode; the tail end and the detection end of the first electrode are respectively located at both ends of the first electrode.

4. The electromagnetic flowmeter according to claim 1, characterized in that The electromagnetic flowmeter further includes two second electrodes, which are respectively arranged at the two opening ends of the pipe, and the two second electrodes are arranged on both sides of one of the first electrodes. After the heads of the two second electrodes respectively pass through the side wall of the pipe, they can contact the liquid flowing through the pipe; A second electrode mounting hole is further formed on one of the electrode mounting surfaces, and the head of the second electrode passes through the second electrode mounting hole, and the head end surface of the second electrode is substantially flush with the inner side wall of the pipe; The tails of the two second electrodes are in contact with the signal acquisition board on the corresponding side to be grounded.

5. The electromagnetic flowmeter according to claim 4, wherein, The signal acquisition board is provided with a grounding hole corresponding to the position of the second electrode, and the tail of the second electrode is matched with the grounding hole to realize the grounding of the second electrode.

6. The electromagnetic flowmeter according to claim 1, characterized in that, The coil assembly includes an iron core, a coil bobbin sleeved on the iron core, and a coil wound on the coil bobbin; The coil bobbin is fixedly connected to the outer side wall of the pipe.

7. The electromagnetic flowmeter according to claim 1, characterized in that, The pipes include four, and the coil assemblies include two. One of the coil assemblies is arranged between one group of two adjacent pipes, and the other coil assembly is arranged between the other group of two adjacent pipes; the two coil assemblies are coaxially arranged.

8. The electromagnetic flowmeter according to claim 1, wherein, Four signal acquisition boards corresponding to one row of the first electrodes are integrally formed to form a first signal acquisition board; Among the four signal acquisition boards corresponding to the other row of the first electrodes, two of them are integrally formed in pairs to form a second signal acquisition board and a third signal acquisition board respectively; The first signal acquisition board is parallel to the second signal acquisition board and the third signal acquisition board, and the first signal acquisition board is arranged opposite to the second signal acquisition board and the third signal acquisition board, and the second signal acquisition board and the third signal acquisition board are located on the same plane.

9. The electromagnetic flowmeter according to claim 8, wherein, The electromagnetic flowmeter further includes a main circuit board and two parallel signal lines; The main circuit board is arranged on one side of the first signal acquisition board, and electrical connection parts are arranged at positions on the main circuit board facing the second signal acquisition board and the third signal acquisition board, and electrical cooperation parts are arranged at corresponding positions of the first signal acquisition board. The electrical connection parts are connected to the electrical cooperation parts to realize the electrical connection between the first signal acquisition board and the main circuit board; Both ends of one of the signal lines are respectively connected to the same side of the first signal acquisition board and the second signal acquisition board to realize the electrical connection between the first signal acquisition board and the second signal acquisition board; Both ends of the other signal line are respectively connected to the same side of the first signal acquisition board and the third signal acquisition board to realize the electrical connection between the first signal acquisition board and the third signal acquisition board; The main circuit board is used to obtain the flow rate and / or velocity of the liquid in the four pipes according to the signals collected by the first signal acquisition board, the second signal acquisition board and the third signal acquisition board.

10. An agricultural plant protection machine, characterized in that, The agricultural plant protection machine includes a frame, a water tank, a water distributor, the electromagnetic flowmeter according to any one of claims 1 to 9, a pump device and a nozzle. Among them, the water tank and the nozzle are installed on the frame, the water inlet of the water distributor is communicated with the water outlet of the water tank, the water outlet of the water distributor is communicated with the water inlet of the pump device through the electromagnetic flowmeter, and the water outlet of the pump device is communicated with the nozzle.

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