Timely drip irrigation wetting monitoring device

Abstract

The invention provides a timely drip irrigation wetting monitoring device which comprises two detection units and a water distribution valve, the detection units are separately inserted into two sides of a ridge and are respectively provided with a buried screen pipe coated with a water permeable film, and a floating rod in the screen pipe floats up along with water and is connected with a piston cylinder (with an injection port) which stretches and retracts synchronously; a water distribution valve is connected with two detection units through water pipes, a water inlet is formed in one side of a valve cavity, two water outlets (connected with drip irrigation pipes) are formed in the opposite side of the valve cavity, a valve element in the cavity can coaxially move, a first flow channel and two second flow channels (located at the two ends of the first flow channel) with larger opening degrees are formed in the valve element, and differential water supply of the water outlets in the two sides can be achieved. The device enriches underground water through the buried screen pipe, drives the water distribution valve to act through buoyancy to control the drip irrigation amount, and compared with indirect control through temperature in the prior art, the device directly regulates and controls according to the underground water content, the influence of climate change is avoided, and the drip irrigation water distribution accuracy is improved.

Description

Technical Field

[0001] This invention relates to the field of agricultural irrigation technology, and in particular to a real-time drip irrigation moisture monitoring device. Background Technology

[0002] In some farmland drip irrigation monitoring devices, soil temperature is often used as a control signal to indirectly control the amount of water allocated for drip irrigation in order to differentiate water distribution based on different soil moisture conditions. For example, the water distribution is reduced in areas with lower soil temperatures and increased in areas with higher soil temperatures. However, this method of controlling drip irrigation water distribution using temperature has significant climatic limitations. For instance, a control strategy set according to summer soil temperature will be exactly the opposite of the soil moisture conditions in winter. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a timely drip irrigation moisture monitoring device that overcomes or at least partially solves the above problems, and can solve the problem of poor climate adaptability of existing drip irrigation monitoring devices.

[0004] Specifically, the present invention provides a real-time drip irrigation moisture monitoring device, characterized in that it includes:

[0005] Two detection units are used to be inserted into both sides of the ridge respectively. Each detection unit includes a buried screen tube. The buried screen tube is covered with a water-permeable membrane. A float rod is installed inside the buried screen tube to float with the water. The float rod is connected to a piston cylinder for synchronous extension and retraction. The piston cylinder has an injection port.

[0006] A water distribution valve connected between the two detection units via a water pipe includes a sleeve-shaped valve cavity. One side of the valve cavity has an inlet, and the opposite side has two spaced-apart outlets. The two outlets are respectively connected to drip irrigation pipes. A valve core is coaxially and reciprocally connected within the valve cavity. The valve core has a first flow channel and two second flow channels. The two second flow channels are located at both ends of the first flow channel and have a larger opening than the first flow channel. This ensures that when one outlet is connected to one second flow channel and the other outlet is connected to the first flow channel, the flow rate in the second flow channel is greater than the flow rate in the first flow channel.

[0007] Furthermore, the float rod is connected to the piston cylinder via a reversing mechanism, the reversing mechanism comprising:

[0008] An active cone is coaxially fixed to the upper end of the float, with its larger end facing upwards;

[0009] A driven arc plate coaxially fixed to the end of the piston rod in the piston cylinder, which abuts against the conical surface of the driving cone; and,

[0010] Under the action of water pressure in the water pipe, the piston cylinder presses the driven arc plate against the conical surface of the active cone.

[0011] Furthermore, the detection unit also includes:

[0012] The protective cylinder, which is fitted outside the active cone, has an installation port at its lower end for the float rod to pass through, and a guide port at its upper end that is coaxial with the active cone. The cylinder wall has a side opening for the piston rod of the piston cylinder to pass through.

[0013] A guide rod coaxially connected to the upper end of the active cone passes through the guide port, and its upper end forms a dust cap for blocking the protective cylinder; and,

[0014] At least one of the float rod, the active cone, and the guide rod is made of plastic.

[0015] Furthermore, the central axis of the inlet on the valve cavity coincides with the centerline between the two outlets, and the two outlets have the same diameter. The diameter of the inlet is equal to or greater than the distance between the farthest points of the two outlets.

[0016] Furthermore, the valve cavity wall also has two water inlets for injecting water into the water pipe, which are located at both ends of the valve cavity.

[0017] Furthermore, an extrusion mechanism is provided between the buried screen pipe and the float rod, the extrusion mechanism comprising:

[0018] The hydrophilic material fixed on the inner wall of the buried screen pipe forms an inner conical sleeve with a larger upper part and a smaller lower part, and the bottom of the hydrophilic material is spaced above the lower end of the buried screen pipe.

[0019] A strip-shaped lever, its upper end fixed to the buried screen pipe, is attached to the inner wall of the hydrophilic material, and its lower end is freely disposed; and,

[0020] The lower end of the buried screen pipe has a bypass channel located below the hydrophilic material, and the lower end of the float rod forms a conical float that is adapted to the inner cavity of the hydrophilic material.

[0021] Furthermore, the buried screen pipe includes:

[0022] The outer cylinder has an outer flow channel that gradually slopes upwards from the outside to the inside;

[0023] An inner cylinder is coaxially connected to the outer cylinder, and an inner flow channel is formed on its cylinder wall that gradually slopes downward from the outside to the inside. The inner flow channel and the outer flow channel are arranged opposite to each other, and there is an annular cavity between the inner flow channel and the outer flow channel.

[0024] The beneficial effects of this invention are:

[0025] In the real-time drip irrigation moisture monitoring device of this invention, groundwater is enriched by buried screen pipes, and the buoyancy of the water is used to drive the water distribution valve, thereby achieving control over the amount of drip irrigation water. Compared with the prior art that uses temperature to indirectly control the amount of drip irrigation water, the real-time drip irrigation moisture monitoring device of this invention directly controls the amount of drip irrigation based on the groundwater content, thus avoiding the adverse effects of climate change on the control of drip irrigation water distribution, and making the control of drip irrigation water distribution more accurate.

[0026] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0027] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0028] Figure 1 This is a schematic structural diagram of a real-time drip irrigation moisture monitoring device according to an embodiment of the present invention;

[0029] Figure 2 yes Figure 1 Enlarged view of section A in the image;

[0030] Figure 3 yes Figure 1 Enlarged view of section B in the image;

[0031] Figure 4 This is a schematic structural diagram of a detection unit according to an embodiment of the present invention;

[0032] Figure 5 yes Figure 4 Enlarged view of section C in the image;

[0033] Figure 6 yes Figure 4 Enlarged view of section D in the image;

[0034] Figure 7 This is a schematic structural diagram of a real-time drip irrigation moisture monitoring device according to an embodiment of the present invention used in a farmland drip irrigation system.

[0035] in:

[0036] Detection unit 100, buried screen pipe 110, inner cylinder 111, outer cylinder 112, annular cavity 113, bypass channel 114, permeable membrane 120, float rod 130, piston cylinder 140, active cone 151, driven arc plate 152, protective cylinder 161, guide rod 162, hydrophilic material 171, strip-shaped paddle 172, ground cone 180, fixing sleeve 191, spring 192;

[0037] Water distribution valve 200, water inlet 210, water outlet 220, valve core 230, first flow channel 231, second flow channel 232, water distribution port 240;

[0038] 300mm for the ridge, 400mm for the water pipe, and 500mm for the drip irrigation pipe. Detailed Implementation

[0039] In the description of embodiments in this invention, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] Figure 1 This is a schematic structural diagram of a real-time drip irrigation moisture monitoring device according to an embodiment of the present invention, such as... Figure 1 As shown, and refer to Figures 2 to 7This invention provides a real-time drip irrigation moisture monitoring device, which abandons the limitations of traditional methods that use soil temperature as an indirect control signal. Instead, it drives drip irrigation water distribution adjustment by directly sensing the actual soil moisture content: a buried screen pipe covered with a permeable membrane is inserted into both sides of the ridge. Utilizing the characteristic of the permeable membrane that only allows water to seep in, soil moisture accumulates in the screen pipe, thereby triggering an internal float rod to rise and fall with the water level. The float rod synchronously drives the piston cylinder to extend and retract through a reversing mechanism (the active cone and the driven arc plate cooperate, and the water pressure in the water pipe ensures close contact and transmission). The piston cylinder's movement further pushes the valve core in the water distribution valve to move coaxially and reciprocally. The water distribution valve core has a first flow channel (small opening) and a second flow channel (large opening) with different opening degrees. When the valve core moves so that the outlets on both sides connect to different flow channels, differentiated drip irrigation water supply can be achieved according to the soil moisture content on both sides of the ridge (reflected by the displacement of the float rod; low moisture content results in a lower float rod position and triggers a large flow channel, while high moisture content triggers a small flow channel). Meanwhile, the outer flow channel (inclined upwards from the outside to the inside) and the inner flow channel (inclined downwards from the outside to the inside) of the buried screen tube form an annular cavity. Combined with the extrusion mechanism composed of hydrophilic material and conical float, it can accelerate the accumulation of soil moisture into the screen tube to improve detection sensitivity, and avoid water accumulation in the screen tube from affecting detection accuracy through the bypass flow channel. Ultimately, it can achieve precise drip irrigation control based on actual soil moisture, unaffected by climate and temperature.

[0041] Specifically, in some embodiments of the present invention, the timely drip irrigation moisture monitoring device mainly consists of a detection unit 100 and a water distribution valve 200. Two detection units 100 are respectively inserted into both sides of the ridge 300. Each detection unit 100 includes a buried screen tube 110, the outer surface of which is covered with a permeable membrane 120. A float rod 130 for floating with water is installed inside the buried screen tube 110. The float rod 130 is connected to a piston cylinder 140 for synchronous extension and retraction, and the piston cylinder 140 has an injection port. A water distribution valve 200 connected between two detection units 100 via a water pipe 400 includes a sleeve-shaped valve cavity. One side of the valve cavity has an inlet 210 (dashed line), and the opposite side has two spaced-apart outlets 220. The two outlets 220 are respectively connected to drip irrigation pipes 500. A valve core 230 is coaxially and reciprocally connected within the valve cavity. The valve core 230 has a first flow channel 231 and two second flow channels 232. The two second flow channels 232 are located at both ends of the first flow channel 231 and have a larger opening than the first flow channel 231. This ensures that when one outlet 220 is connected to one second flow channel 232 and the other outlet 220 is connected to the first flow channel 231, the flow rate in the second flow channel 232 is greater than the flow rate in the first flow channel 231.

[0042] In this embodiment, the operation process of the timely drip irrigation moisture monitoring device includes:

[0043] Soil moisture detection stage: Two detection units 100 are inserted into the soil on both sides of the ridge 300. The permeable membrane 120 covering the buried screen tube 110 only allows soil moisture to seep into the screen tube, preventing soil particles from entering. When the soil moisture content changes, the water level inside the screen tube changes synchronously—high soil moisture content results in more water and a higher water level, while low soil moisture content results in less water and a lower water level. The float rod 130 inside the screen tube moves with the rise and fall of the water level, which in turn drives the piston cylinder 140 connected to it to extend and retract synchronously. The piston cylinder 140 is linked to the water pipe 400 through the injection port, converting the soil moisture signal reflected by the float rod 130 into a mechanical action signal.

[0044] Water distribution adjustment stage: Water pipe 400 connects two detection units 100 and water distribution valve 200. The extension and retraction of piston cylinder 140 pushes valve core 230 in water distribution valve 200 to move coaxially along the valve cavity. Water distribution valve 200 has an inlet 210 (connected to water source) on one side of the valve cavity and two outlets 220 on the opposite side (connected to drip irrigation pipes 500 on both sides of the ridge 300 respectively). The first flow channel 231 (small opening) and two second flow channels 232 (large opening, located at both ends of the first flow channel 231) on valve core 230 switch the docking state with outlet 220 as valve core 230 moves. When the detection unit 100 on one side reports low soil moisture content (the displacement of the float rod 130 triggers the corresponding action), the valve core 230 moves to connect the outlet 220 on that side with the second flow channel 232, and the outlet 220 on the other side with the first flow channel 231, thus achieving differentiated water distribution with a large drip irrigation flow on the low moisture content side and a small flow on the high moisture content side. If the moisture content on both sides is similar, the valve core 230 is in the middle position, and the outlets 220 on both sides can connect with either the first flow channel 231 or the second flow channel 232 to ensure uniform water distribution.

[0045] Taking a wheat planting field in the northern plains as an example, a plot of land 100m long and 50m wide was selected. The plot was planted using conventional ridge planting methods, with ridges 0.8m wide and 0.3m high, totaling 60 ridges 300. A detection unit 100 was inserted on both sides of each ridge 300 (0.2m from the ridge edge). A buried screen tube 110 was inserted to a depth of 0.4m (corresponding to the main water absorption layer of the wheat root system). The permeable membrane 120 was made of non-woven fabric with a pore size of 0.1mm to prevent clogging by fine soil sand. The water distribution valve 200 is installed in the middle of each ridge 300 and is connected to the piston cylinder 140 of the detection unit 100 on both sides through a PE water pipe 400 with a diameter of 50mm. The water inlet 210 of the water distribution valve 200 is connected to the main water supply pipe 400 of the field (water pressure is maintained at 0.2MPa). The two outlets 220 are respectively connected to drip irrigation pipes 500 with a diameter of 20mm. A dripper is installed on the drip irrigation pipe 500 every 0.5m.

[0046] During the wheat jointing stage (a water-sensitive stage), if the water content on the east side of a certain ridge 300 drops to 16% (lower than the suitable water content of 18%-22%) due to its proximity to the field ridge and slightly poor soil water retention, the water level in the buried screen pipe 110 of the detection unit 100 on the east side will drop, causing the float rod 130 to move down, which will cause the piston cylinder 140 to contract and push the valve core 230 of the water distribution valve 200 to move eastward, so that the east outlet 220 connects with the second flow channel 232 (with an opening 1.5 times that of the first flow channel 231), and the west outlet 220 connects with the first flow channel 231. At this time, the dripper flow rate of the dripper 500 on the east side is increased from the normal 2L / h to 3L / h, while the flow rate on the west side remains at 2L / h. After two hours of continuous drip irrigation, the soil moisture content on the east side rises to 19%. The float rod 130 rises, causing the piston cylinder 140 to extend and the valve core 230 to reset. Both outlets 220 on both sides are connected to the first flow channel 231, restoring normal water distribution. This satisfies the water replenishment needs of the soil on the east side while avoiding over-irrigation of the soil on the west side.

[0047] Therefore, compared to traditional devices that use ground temperature as a control signal, this device directly adjusts water distribution based on soil moisture content, unaffected by seasonal or diurnal temperature variations. For example, during hot summer months, if a certain area still has high moisture content due to soil texture, the device can reduce the drip irrigation volume in that area, avoiding the misjudgment of "more irrigation for high temperatures." During cold winter months, if the soil is dry, the device can still increase the drip irrigation volume normally, solving the problem of poor climate adaptability of traditional devices and improving the matching degree between drip irrigation water distribution and actual soil moisture by more than 30%.

[0048] By differentiating water allocation, water waste caused by over-irrigation in some areas is avoided, while the differences in crop growth caused by uneven irrigation are reduced. In the wheat planting project example mentioned above, after applying this device, the irrigation water consumption of the entire field was reduced by 15%-20% compared with traditional uniform irrigation, the average irrigation cost per mu was reduced by 8-12 yuan, and the thousand-grain weight of wheat increased by 5%-8%, achieving the dual benefits of water saving and increased yield.

[0049] The permeable membrane 120 of the buried screen pipe 110 is combined with the screen pipe structure, which can efficiently collect soil moisture and prevent clogging. The linkage between the float rod 130 and the piston cylinder 140 is achieved through a mechanical structure, which eliminates the need for electronic components, avoids damage to electronic equipment caused by the wet environment in the field, reduces the failure rate of the device to less than 5%, and has a service life of more than 5 years, reducing the workload and cost of later maintenance.

[0050] In some preferred embodiments of the present invention, the float rod 130 is connected to the piston cylinder 140 via a reversing mechanism. The reversing mechanism mainly includes an active cone 151 and a driven arc plate 152 (integrated with the piston rod of the piston cylinder 140). The active cone 151, coaxially fixed to the upper end of the float, has its larger end facing upwards. The driven arc plate 152, coaxially fixed to the end of the piston rod of the piston cylinder 140, abuts against the conical surface of the active cone 151. Under the action of water pressure within the water pipe 400, the driven arc plate 152 is pressed tightly against the conical surface of the active cone 151 via the piston cylinder 140.

[0051] In this embodiment, the operation process of the timely drip irrigation moisture monitoring device includes:

[0052] Power transmission trigger: When the soil moisture content changes on both sides of the ground ridge 300, the water level in the buried screen tube 110 inside the detection unit 100 changes, causing the float rod 130 to rise and fall synchronously. Since the active cone 151 is coaxially fixed to the upper end of the float rod 130, the rise and fall of the float rod 130 will directly drive the active cone 151 to move in the vertical direction (when the soil moisture content is high, the float rod 130 rises and the active cone 151 moves upward; when the moisture content is low, the float rod 130 falls and the active cone 151 moves downward).

[0053] Motion reversal and transmission: The driven arc plate 152 is coaxially fixed to the end of the piston rod of the piston cylinder 140 and always fits against the conical surface of the driving cone 151. Under the continuous action of water pressure in the water pipe 400, the piston cylinder 140 will generate a thrust on the piston rod, causing the driven arc plate 152 to be tightly pressed against the conical surface of the driving cone 151, ensuring that there is no relative sliding between the two. When the driving cone 151 moves vertically, its conical surface will generate a horizontal component force on the driven arc plate 152, converting the vertical motion of the driving cone 151 into the horizontal motion of the driven arc plate 152, thereby driving the piston rod to extend and retract horizontally, realizing the power transmission and reversal of "vertical displacement of the float rod 130 → vertical movement of the driving cone 151 → horizontal movement of the driven arc plate 152 → extension and retraction of the piston rod".

[0054] Water distribution valve 200 linkage adjustment: The extension and retraction of the piston rod will directly push the valve core 230 in the water distribution valve 200 to move coaxially along the valve cavity, changing the docking state of the first flow channel 231 and the second flow channel 232 on the valve core 230 with the water outlet 220 of the water distribution valve 200, and finally realizing the differential adjustment of drip irrigation flow based on soil moisture content.

[0055] Continuing with the engineering scenario of a wheat planting field in the northern plains (the plot is 100m long and 50m wide, with 60 ridges 300m wide, a detection unit 100 inserted to a depth of 0.4m, and a water distribution valve 200 connecting a PE water pipe 400 to a drip irrigation pipe 500), the reversing mechanism is specifically designed for application: the active cone 151 is made of ABS plastic, with a cone apex angle of 60°, a large end diameter of 50mm, and a small end diameter of 20mm, and is fixed to the upper end of the float rod 130 (a PP plastic rod with a diameter of 25mm) by threads; the driven arc plate 152 is made of wear-resistant nylon, with an arc surface curvature that perfectly matches the cone surface of the active cone 151, and a thickness of 8mm, and is fixed to the end of the piston rod (a stainless steel rod with a diameter of 15mm) by welding; the water pressure in the water pipe 400 is stably maintained at 0.2MPa to ensure that the clamping force of the driven arc plate 152 on the active cone 151 reaches 150N, preventing relative slippage between the two.

[0056] When the soil moisture content on the east side of a certain ridge 300 drops to 16%, the float rod 130 of the east side detection unit 100 drops by 100mm, causing the active cone 151 to move down by 100mm in sync. As the driven arc plate 152 presses against the cone surface of the active cone 151, during the downward movement of the active cone 151, its cone surface generates a horizontal thrust on the driven arc plate 152, pushing the piston rod to retract horizontally by 86.6 mm. The retraction of the piston rod causes the valve core 230 of the water distribution valve 200 to move 57.7 mm to the east, so that the east outlet 220 connects with the second flow channel 232 and the west outlet 220 connects with the first flow channel 231, thereby increasing the drip irrigation flow on the east side. When the soil moisture content on the east side rises to 19%, the float rod 130 rises by 100 mm, the active cone 151 moves upward, pushing the driven arc plate 152 and the piston rod to extend horizontally by 57.7 mm, the valve core 230 resets, and the uniform water distribution on both sides is restored.

[0057] Therefore, under the water pressure of 400, the driven arc plate 152 tightly presses against the cone surface of the active cone 151, preventing relative sliding between the two due to field factors such as vibration and soil settlement. This ensures that the displacement of the float rod 130 can be converted into the extension and retraction of the piston rod in a 1:1 ratio, and the power transmission error is controlled within 5%. Compared with the reversing design without a pressing structure, this scheme can reduce the problem of water distribution adjustment lag caused by transmission gaps, and improve the drip irrigation flow response speed by 20%. The active cone 151 is made of ABS plastic and the driven arc plate 152 is made of wear-resistant nylon, both of which have the characteristics of soil corrosion resistance and UV aging resistance. Moreover, the contact surfaces of the two do not require lubrication (relying on the wear resistance of the materials themselves), avoiding damage to the lubrication system by field dust and moisture. The piston rod is made of stainless steel, which can prevent corrosion caused by salt in the soil. The overall reversing mechanism has a failure rate of less than 3%, and its service life is extended by 2-3 years compared with the metal friction reversing structure, reducing the later maintenance cost. The reversing mechanism consists of only two core components: the active cone 151 and the driven arc plate 152. It does not have complex gears, cams or other transmission components. During assembly, the active cone 151 is fixed to the float rod 130 and the driven arc plate 152 is fixed to the piston rod. Then, the water pressure of 400 is used to achieve the clamping. The assembly time of a single set of mechanisms is controlled within 10 minutes, which improves the assembly efficiency by 50% compared with the traditional multi-component reversing structure, making it easy to promote and apply on a large scale in the field.

[0058] In some further preferred embodiments of the present invention, the detection unit 100 further includes a protective cylinder 161 and a guide rod 162. The protective cylinder 161 is loosely fitted over the active cone 151, with a mounting port at its lower end for the float rod 130 to pass through, and a guide port coaxial with the active cone 151 at its upper end, and a side opening on its cylinder wall for the piston rod of the piston cylinder 140 to pass through. The guide rod 162 is coaxially connected to the upper end of the active cone 151, passes through the guide port, and has a dust cap at its upper end for blocking above the protective cylinder 161. At least one of the float rod 130, the active cone 151, and the guide rod 162 is made of plastic.

[0059] The protective cylinder 161 is loosely fitted over the active cone 151. Through the mounting port at the lower end through which the float rod 130 passes, the guide port at the upper end which is coaxial with the active cone 151, and the side opening in the cylinder wall through which the piston rod passes, a closed protective space is formed for the active cone 151, the connection between the float rod 130 and the piston rod, preventing field impurities from contacting the core transmission components. The guide rod 162 is coaxially connected to the upper end of the active cone 151 and passes through the guide port. When the float rod 130 rises and falls due to changes in soil moisture content, it slides along the guide port to constrain the vertical movement of the active cone 151 and prevent it from swaying. At the same time, the dust cap at the upper end of the guide rod 162 blocks the protective cylinder 161, preventing impurities from entering from the guide port and limiting the active cone 151 when it rises to its maximum stroke, preventing the active cone 151 from detaching from the driven arc plate 152. Its technical advantages are reflected in the following aspects: effectively reducing interference from impurities and transmission jamming, significantly reducing the failure rate of core transmission components; at the same time, through the attitude constraint of the guide rod 162, controlling the sway of the active cone 151 to a very small range, reducing displacement transmission error and ensuring the accuracy of drip irrigation water distribution adjustment; at least one of the float rod 130, active cone 151 and guide rod 162 is made of plastic, which has the characteristics of soil corrosion resistance, UV aging resistance and lightweight, extending the service life of the device in complex field environments (such as saline-alkali land) and reducing the labor intensity of installation; in addition, the protective design reduces the frequency of impurity cleaning, and components can be replaced individually when damaged, significantly reducing the average annual maintenance cost and making it suitable for long-term stable operation in large-scale farmland.

[0060] In some preferred embodiments of the present invention, the central axis of the inlet 210 on the valve cavity coincides with the centerline between the two outlets 220, and the two outlets 220 have the same diameter. The diameter of the inlet 210 is equal to or greater than the distance between the farthest points of the two outlets 220.

[0061] Therefore, the central axis of the inlet 210 coincides with the central axis between the two outlets 220, which ensures that the flow path length and resistance of the water source from the inlet 210 to the two outlets 220 are consistent. This avoids the problem of the flow rate of the outlet 220 being inherently larger on one side due to the water inlet being biased to one side, and lays the foundation for "initial flow balance" for subsequent differentiated water distribution based on the flow channel switching of the valve core 230. The equal diameter design of the two outlets 220 further ensures that the basic flow rate of the drip irrigation pipes 500 on both sides is completely consistent under the same flow channel connection state (such as both connected to the first flow channel 231 or both connected to the second flow channel 232), thus structurally eliminating the uneven water distribution caused by the size difference of the outlets 220. The diameter of the inlet 210 is equal to or greater than the distance between the farthest points of the two outlets 220. This means that the inlet 210 has a sufficiently large flow cross-section, enabling it to quickly receive external water and form a stable water flow field within the valve cavity. This avoids problems such as excessively fast water flow velocity and sudden drops in local pressure caused by an overly narrow inlet 210. Simultaneously, ample flow space reduces eddies and impacts in the water flow within the valve cavity, minimizing pressure loss along the flow path. This ensures that the two outlets 220 consistently receive the water pressure and flow rate required by the design, preventing uneven water distribution from the drip irrigation head and reduced drip irrigation effectiveness due to insufficient pressure. This design works in synergy with the layout of the first flow channel 231 and the second flow channel 232 on the valve core 230. When the valve core 230 moves coaxially along the valve cavity, the coincidence of the central axis of the inlet 210 and the central axis of the outlet 220 allows the water flow to accurately enter the corresponding flow channel of the valve core 230 and then be evenly distributed to the outlets 220 on both sides. The large diameter design of the inlet 210 provides sufficient adjustment space for the water flow rate change when the valve core 230 switches flow channels. Whether it is the small opening of the first flow channel 231 or the large opening of the second flow channel 232, a stable water supply can be obtained through the inlet 210, ensuring the linearity and accuracy of flow rate adjustment when differentiating water distribution, and avoiding the problem that the flow rate does not reach the design value after the flow channel is switched due to insufficient water supply.

[0062] Continuing with the engineering scenario of a wheat planting field in the northern plains (60 ridges 300, water distribution valve 200 connecting a 50mm diameter PE water pipe 400 and a 20mm diameter drip irrigation pipe 500, with water pressure maintained at 0.2MPa in the water pipe 400), the inlet 210 and outlet 220 of the water distribution valve 200 are specifically designed:

[0063] The valve chamber of the water distribution valve 200 is made of stainless steel with an inner diameter of 80mm. Two water outlets 220 are symmetrically distributed on one side of the valve chamber. The center-to-center distance (i.e., the distance between the farthest points of the two water outlets 220, since the water outlets 220 are circular, the distance between the farthest points is equal to the center-to-center distance of the two water outlets 220) is set to 60mm. The inner diameter of each water outlet 220 is 25mm (to be compatible with the drip irrigation pipe 500 and ensure that the water flows smoothly into the drip irrigation pipe 500).

[0064] The inlet 210 is located on the opposite side of the valve chamber, with its central axis completely coinciding with the center line connecting the centers of the two outlets 220. The inner diameter of the inlet 210 is set to 60mm (equal to the distance between the farthest points of the two outlets 220), and the inlet 210 is connected to the main water supply pipe 400 (50mm in diameter) of the field through a flange. The water supply pressure of the main water supply pipe 400 is stable at 0.2MPa, ensuring that the inlet 210 can continuously obtain a sufficient water source.

[0065] In practical applications, when the valve core 230 is in the middle position and both outlets 220 are connected to the first flow channel 231 (opening degree corresponds to a flow rate of 2L / h), because the centerline of the inlet 210 coincides with the centerline of the outlet 220 and the outlets 220 have the same diameter, the actual outflow rate of both outlets 220 is consistently maintained at 2L / h, with a flow rate deviation of less than 2%. When the valve core 230 moves to connect one outlet 220 to the second flow channel 232 (opening degree corresponds to a flow rate of 3L / h), the actual outflow rate of both outlets 220 is consistently maintained at 2L / h, with a flow rate deviation of less than 2%. h) When the other side is connected to the first flow channel 231, the large diameter design of the inlet 21060mm can quickly replenish the water flow. The actual flow rates of the outlets 220 on both sides are stable at 3L / h and 2L / h respectively, and the flow deviation is still controlled within 3%. This fully meets the needs of wheat planting fields for precise adjustment of drip irrigation flow, avoids water distribution deviation caused by improper design of inlet 210 and outlet 220, and ensures that soils in different moisture content areas can obtain appropriate irrigation water.

[0066] In some preferred embodiments of the present invention, the cavity wall of the valve cavity is further provided with a water inlet 240 for injecting water into the water pipe 400. There are two water inlets 240, which are located at both ends of the valve cavity and at both ends of the valve core 230.

[0067] Therefore, the two water inlets 240 are located at both ends of the valve cavity and at both ends of the valve core 230, respectively. When water is injected into the water pipe 400, it can directly act on both sides of the valve core 230, ensuring that the water pressure at both ends of the valve core 230 remains balanced. This design avoids the valve core 230 from shifting or getting stuck due to excessively high or low water pressure on one side, making the valve core 230 move more smoothly along the valve cavity coaxially. This ensures the accuracy of the connection between the first flow channel 231, the second flow channel 232 and the outlet 220, reduces the fluctuation of drip irrigation flow caused by the adjustment deviation of the valve core 230, and provides a stable pressure environment for differentiated water distribution. The water inlets 240 are set at both ends of the valve core 230, and can selectively replenish water to the water pipe 400 section (i.e., the water pipe 400 area on both sides of the valve core 230) connecting the detection unit 100 and the water distribution valve 200. When the piston cylinder 140 extends and retracts with the movement of the float rod 130, the water volume in the water pipes 400 at both ends of the valve core 230 will experience local changes. At this time, the water outlet 240 can quickly replenish the corresponding area with water, avoiding local interruption or insufficient water volume in the water pipes 400. This ensures that the piston cylinder 140 always has a stable water pressure to drive the driven arc plate 152 to adhere to the active cone 151, ensuring the continuity of the transmission link of "soil moisture content - float rod 130 displacement - piston rod extension and retraction - valve core 230 adjustment" and reducing transmission delays caused by untimely water replenishment. When the device is first started or restarted, air may remain in the water pipes 400 at both ends of the valve core 230, forming local air resistance, which will affect the movement of the piston cylinder 140 and the adjustment of the valve core 230. When water is injected through the water inlets 240 located at both ends of the valve core 230, the water pipes 400 on both sides of the valve core 230 can be vented directly "point-to-point" to expel residual air from both ends of the water pipes 400, thus preventing air from accumulating near the valve core 230 and causing adjustment blockage. In daily use, if a small amount of air enters the water pipes 400 at both ends of the valve core 230 due to sealing issues, the water inlets 240 can also expel the air in time, ensuring smooth water flow in the area around the valve core 230 and maintaining the overall adjustment performance of the water distribution valve 200.

[0068] In some preferred embodiments of the present invention, an extrusion mechanism is provided between the buried screen pipe 110 and the float rod 130. The extrusion mechanism mainly includes a hydrophilic material 171 and a strip-shaped lever 172. The hydrophilic material 171 is fixed to the inner wall of the buried screen pipe 110, forming an inner conical sleeve with a larger upper part and a smaller lower part, and the bottom of the hydrophilic material 171 is spaced above the lower end of the buried screen pipe 110. The upper end of the strip-shaped lever 172 is fixed to the buried screen pipe 110, and it is attached to the inner wall surface of the hydrophilic material 171, while its lower end is freely disposed. The lower end of the buried screen pipe 110 has a bypass channel 114 located below the hydrophilic material 171, and the lower end of the float rod 130 forms a conical float adapted to the inner cavity of the hydrophilic material 171.

[0069] Preferably, the strip-shaped lever 172 can be one or more. Especially when there are multiple strip-shaped levers 172, these strip-shaped levers 172 are evenly distributed in the circumferential direction so that the upward push of the conical float is balanced.

[0070] Therefore, in this embodiment, the working process of the timely drip irrigation moisture monitoring device includes:

[0071] Moisture accumulation and float triggering: After the buried screen tube 110 is inserted into the soil, soil moisture seeps into the tube through the permeable membrane 120 on the outer wall of the screen tube and is preferentially adsorbed by the hydrophilic material 171 fixed to the inner wall of the tube. Because the hydrophilic material 171 forms an inner cone shape that is larger at the top and smaller at the bottom, and the bottom is separated from the lower end of the screen tube to form a space, the adsorbed moisture will accumulate in the inner cavity of the hydrophilic material 171 and the area below it. When the moisture content reaches a certain level, the conical float at the lower end of the float rod 130, which is adapted to the inner cavity of the hydrophilic material 171, is subjected to buoyancy and begins to move upward along the inner cavity of the hydrophilic material 171.

[0072] Extrusion and impurity removal and motion guidance: As the conical float moves upward, its conical surface fits tightly against the inner conical sleeve of the hydrophilic material 171, squeezing out excess water absorbed by the hydrophilic material 171 and small soil particles that may be attached to the wall (the permeable membrane 120 may occasionally leak). At the same time, the strip-shaped paddle 172 (free at the lower end) attached to the inner wall of the hydrophilic material 171 deforms synchronously under the push of the conical float, which not only helps to scrape off the residual impurities on the inner wall, but also guides and constrains the upward trajectory of the conical float through its own elasticity, preventing the float from swaying due to uneven force.

[0073] Redundant drainage and reset coordination: When the soil moisture content decreases, the water level in the screen tube drops, and the conical float falls accordingly, allowing the hydrophilic material 171 to reabsorb residual water; if there is redundant water accumulation in the screen tube, excess water can be discharged through the bypass channel 114 located below the hydrophilic material 171 at the lower end of the screen tube, avoiding water accumulation that could affect the float's sensitivity to changes in moisture content; if there are multiple strip-shaped paddles 172 evenly distributed around the circumference, the float can still maintain a balanced posture when falling, ensuring the fit with the inner wall of the hydrophilic material 171 during the next ascent, and maintaining transmission stability.

[0074] Therefore, the strong adsorption of hydrophilic material 171 can quickly enrich soil moisture, enabling the conical float to respond promptly to small changes in water content (the response threshold is reduced by 15%-20% compared to designs without hydrophilic material 171); the matching design of the inner conical sleeve structure and the conical float, together with the guiding effect of the strip-shaped lever 172, reduces the displacement error caused by the float's sway, improving the accuracy of water content signal transmission to the float rod 130 by more than 25%, providing a precise basis for subsequent water distribution adjustment. The extrusion action of the conical float on the inner wall of the hydrophilic material 171 when it rises, combined with the scraping action of the strip-shaped blade 172, can effectively remove small impurities from the wall surface, preventing soil particles from clogging the pores of the hydrophilic material 171 or jamming the float; the redundant drainage function of the bypass channel 114 prevents water accumulation in the screen tube from breeding microorganisms or causing the hydrophilic material 171 to become moldy, reducing the clogging failure rate of the buried screen tube 110 from more than 20% without this mechanism to less than 5%, and extending the service life of a single detection unit 100 by 2-3 years. Multiple circumferentially distributed strip-shaped levers 172 ensure balanced force distribution when the conical float rises and falls. Even in field environments with uneven soil pressure and slight tilting of the screen tube, the float rod 130 can maintain its vertical movement posture, preventing the active cone 151 from disengaging from the driven arc plate 152. The elastic deformation characteristics of the hydrophilic material 171 can adapt to the slight deformation of the screen tube caused by changes in soil temperature, enhancing the adaptability of the lifting device to complex environments such as low-temperature frozen soil in the north and high-temperature soil in summer.

[0075] Continuing with the engineering scenario of a wheat planting field in the northern plains (60 ridges, 300mm diameter, 100 detection units inserted to a depth of 0.4m, 110mm underground screen tubes made of PE material, covered with a 0.1mm pore size non-woven permeable membrane 120), the extrusion mechanism was specifically designed:

[0076] Hydrophilic material 171: Made of polyacrylamide-based super absorbent resin, 8mm thick, forming an inner conical sleeve with an upper diameter of 50mm and a lower diameter of 30mm. The bottom is 40mm away from the lower end of the buried screen pipe 110 (closed design) to ensure that drainage space is reserved below.

[0077] Strip-shaped lever 172: Three strips of corrosion-resistant nylon material are used, with a width of 10mm and a thickness of 2mm. The upper end is fixed to the inner wall of the buried screen pipe 110 by a buckle, and the lower end is freely attached to the inner wall of the hydrophilic material 171. The three strips are evenly distributed along the circumference at 120° to ensure the balance of the float.

[0078] Bypass channel 114: Four 5mm diameter circular holes are opened on the lower side wall of the buried screen pipe 110, which are evenly distributed around the circumference and located directly below the hydrophilic material 171 to form a bypass channel 114. The outside is wrapped with a permeable membrane 120 to prevent soil particles from entering.

[0079] In practical applications, when the soil moisture content in the wheat-growing area rises from 16% (low moisture) to 19% (suitable moisture), the hydrophilic material 171 rapidly absorbs water, causing the conical float (PP plastic material, weighing 5g) to rise 25mm within 30 seconds, driving the float rod 130 to move synchronously. During the ascent, the conical surface of the float squeezes out excess water from the hydrophilic material 171, and the strip-shaped blades 172 scrape off a small amount of fine sand (particle size <0.05mm) adhering to the wall surface. Impurities are discharged with the water through the bypass channel 114. When the soil moisture content drops to 17%, the float falls smoothly, and the three blades ensure that the float does not wobble, allowing for a rapid response when the moisture content rises again. Throughout the entire wheat growth cycle, the extrusion mechanism did not experience any blockage or jamming. The response time of the detection unit 100 to changes in soil moisture content remained stable at 25-35 seconds, fully meeting the precision drip irrigation needs of key stages such as the wheat jointing and grain-filling stages.

[0080] In some preferred embodiments of the present invention, the buried screen pipe 110 includes an inner cylinder 111 and an outer cylinder 112. An outer flow channel that gradually slopes upwards from the outside to the inside is formed on the wall of the outer cylinder 112. The inner cylinder 111 is coaxially connected inside the outer cylinder 112, and an inner flow channel that gradually slopes downwards from the outside to the inside is formed on its wall. The inner and outer flow channels are arranged opposite to each other, and an annular cavity 113 is provided between the inner and outer flow channels.

[0081] Therefore, the outer flow channel of the outer cylinder 112 is "gradually inclined upward from the outside to the inside", which can guide soil moisture to flow upward along the inclined channel. At the same time, the inclined structure can block some soil particles (especially large-diameter silt), and together with the permeable membrane 120 outside the outer cylinder 112, it forms "double filtration" to reduce the probability of impurities entering the screen tube. The inner flow channel of the inner cylinder 111 is "gradually inclined downward from the outside to the inside", which is set up one-to-one with the outer flow channel. It can further guide the water introduced by the outer flow channel to the inner cylinder 111, avoid water from spreading randomly in the screen tube, and make the water quickly gather in the conical float area at the lower end of the float rod 130. Compared with the single cylinder structure, the water gathering efficiency is increased by more than 40%, and the response time of the float rod 130 to changes in soil moisture content is shortened. The annular cavity 113 formed between the inner and outer flow channels serves as a temporary water storage and buffer space. When soil moisture increases rapidly in a short period (such as during a sudden light rain), the annular cavity 113 can temporarily store excess water, preventing water from rapidly flowing into the inner cylinder 111 and causing the float rod 130 to be falsely triggered. When soil moisture decreases rapidly, the annular cavity 113 can slowly release the stored water, maintaining a relatively stable moisture content within the inner cylinder 111, preventing the float rod 130 from frequently rising and falling due to moisture fluctuations, reducing ineffective adjustments of the water distribution valve 200, and improving the stability of drip irrigation control. Simultaneously, the annular cavity 113 can also isolate the direct impact of soil temperature changes on the moisture content inside the screen tube, reducing differences in moisture evaporation caused by temperature fluctuations, and further ensuring the accuracy of moisture content detection. The coaxial dual-structure design of the inner cylinder 111 and the outer cylinder 112 significantly improves the overall resistance to bending and soil compression compared to the single-cylinder structure. The outer cylinder 112 can withstand external soil pressure, while the inner cylinder 111 protects core components such as the internal float rod 130, preventing deformation and damage to the screen tube caused by field cultivation (such as small agricultural machinery operation) or soil subsidence. The inclined flow channel design can also disperse the local pressure of the soil on the screen tube wall, reduce the risk of flow channel blockage, and extend the service life of the buried screen tube 110 by 3-5 years in complex environments such as northern clay soil and saline-alkali soil, reducing the frequency of device replacement and maintenance costs.

[0082] In practical applications, when the soil moisture content in the field increases from 16% to 19%, the soil moisture is filtered through the permeable membrane 120 of the outer cylinder 112 and flows upward into the annular cavity 113 along the 15° inclined outer channel. Then, it flows downward through the 15° inclined inner channel of the inner cylinder 111 and converges at the center of the inner cylinder 111. In just 20 seconds, the water level in the inner cylinder 111 rises by 25 mm, triggering the float rod 130 to rise synchronously. During this period, some sediment particles with a diameter >0.05 mm are blocked by the inclined structure of the outer channel, and the annular cavity 113 temporarily stores about 10 mL of excess water, preventing the float rod 130 from malfunctioning due to a sudden rise in the water level in the inner cylinder 111. When encountering a short period of light rain (5mm), the water stored in the annular cavity 113 reaches 30mL, effectively buffering the impact of rainwater on the water inside the screen tube. The float rod 130 only rises slightly by 5mm, without triggering a significant adjustment in the water distribution valve 200. After the rain, when the soil moisture recedes, the annular cavity 113 slowly releases water, the water level in the inner cylinder 111 drops steadily, and the float rod 130 gradually returns to its original position. This ensures that the water distribution valve 200 accurately adjusts the drip irrigation flow rate according to the actual soil moisture, fully meeting the water supply stability requirements throughout the wheat's growth cycle. Throughout the entire planting season, none of the 120 monitoring units 100 experienced deformation or blockage in their buried screen tubes 110, maintaining a 100% flow channel patency rate.

[0083] In some other embodiments, the lower end of the buried screen pipe 110 is coaxially connected to a ground cone 180, so that the buried screen pipe 110 can be inserted deeper and more effortlessly into the farmland soil. A weight-reducing cavity is provided inside the conical float, and a roller that rotates and engages with the strip-shaped lever 172 is rotatably connected to the outside to facilitate the smoother ascent of the conical float. The buried screen pipe 110 and the protective cylinder 161 are connected by a fixing sleeve 191, and a spring 192 is connected between the fixing sleeve 191 and the float rod 130 to balance the weight of the float rod 130, so that it can float even in small amounts of water.

[0084] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A real-time drip irrigation moisture monitoring device, characterized in that, include: Two detection units are used to be inserted into both sides of the ridge respectively. Each detection unit includes a buried screen tube. The buried screen tube is covered with a water-permeable membrane. A float rod is installed inside the buried screen tube to float with the water. The float rod is connected to a piston cylinder for synchronous extension and retraction. The piston cylinder has an injection port. A water distribution valve connected between the two detection units via a water pipe includes a sleeve-shaped valve cavity. One side of the valve cavity has an inlet, and the opposite side has two spaced-apart outlets. The two outlets are respectively connected to drip irrigation pipes. A valve core is coaxially and reciprocally connected within the valve cavity. The valve core has a first flow channel and two second flow channels. The two second flow channels are located at both ends of the first flow channel and have a larger opening than the first flow channel. This ensures that when one outlet is connected to one second flow channel and the other outlet is connected to the first flow channel, the flow rate in the second flow channel is greater than the flow rate in the first flow channel.

2. The real-time drip irrigation moisture monitoring device according to claim 1, characterized in that, The float rod is connected to the piston cylinder via a reversing mechanism, the reversing mechanism comprising: An active cone is coaxially fixed to the upper end of the float, with its larger end facing upwards; A driven arc plate coaxially fixed to the end of the piston rod in the piston cylinder, which abuts against the conical surface of the driving cone; and, Under the action of water pressure in the water pipe, the piston cylinder presses the driven arc plate against the conical surface of the active cone.

3. The real-time drip irrigation moisture monitoring device according to claim 2, characterized in that, The detection unit further includes: The protective cylinder, which is fitted outside the active cone, has an installation port at its lower end for the float rod to pass through, and a guide port at its upper end that is coaxial with the active cone. The cylinder wall has a side opening for the piston rod of the piston cylinder to pass through. A guide rod coaxially connected to the upper end of the active cone passes through the guide port, and its upper end forms a dust cap for blocking the protective cylinder; and, At least one of the float rod, the active cone, and the guide rod is made of plastic.

4. The real-time drip irrigation moisture monitoring device according to claim 1, characterized in that, The central axis of the inlet on the valve chamber coincides with the centerline between the two outlets, and the two outlets have the same diameter. The diameter of the inlet is equal to or greater than the distance between the farthest points of the two outlets.

5. The real-time drip irrigation moisture monitoring device according to claim 1, characterized in that, The valve chamber wall also has two water inlets for injecting water into the water pipe, located at opposite ends of the valve chamber.

6. The real-time drip irrigation moisture monitoring device according to claim 1, characterized in that, An extrusion mechanism is provided between the buried screen pipe and the float rod, the extrusion mechanism comprising: The hydrophilic material fixed on the inner wall of the buried screen pipe forms an inner conical sleeve with a larger upper part and a smaller lower part, and the bottom of the hydrophilic material is spaced above the lower end of the buried screen pipe. A strip-shaped lever, its upper end fixed to the buried screen pipe, is attached to the inner wall of the hydrophilic material, and its lower end is freely disposed; and, The lower end of the buried screen pipe has a bypass channel located below the hydrophilic material, and the lower end of the float rod forms a conical float that is adapted to the inner cavity of the hydrophilic material.

7. The real-time drip irrigation moisture monitoring device according to claim 1, characterized in that, The buried screen pipe includes: The outer cylinder has an outer flow channel that gradually slopes upwards from the outside to the inside; An inner cylinder is coaxially connected to the outer cylinder, and an inner flow channel is formed on its cylinder wall that gradually slopes downward from the outside to the inside. The inner flow channel and the outer flow channel are arranged opposite to each other, and there is an annular cavity between the inner flow channel and the outer flow channel.

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