CFD-EDM-based pulse jet power-assisted on-membrane precision seeding device and design method

Abstract

The invention provides a CFD-EDM-based pulse jet power-assisted on-film precision seeding device and a design method, the CFD-EDM-based pulse jet power-assisted on-film precision seeding device comprises a hole making device and a seed sowing device which are arranged in parallel, the hole making device comprises a bottom plate, a motor fixed on the bottom plate through a bracket, a crank fixedly connected with the motor and a first connecting rod hinged with the crank, the device further comprises a second connecting rod, a third connecting rod and a fourth connecting rod. The tail end of the fourth connecting rod is connected with a guide rod. A drill bit is fixedly connected to the guide rod; the seed-metering device comprises a shell, a seed-metering wheel and a blocking wheel, the seed-metering wheel is rotationally connected with the shell, one side of the seed-metering wheel is attached to the inner wall of the shell, and a plurality of nest holes are formed in the seed-metering wheel; a seeding opening is formed in the bottom of the shell, and a cycloid guide rail and an air injection pump are arranged at the seeding opening. According to the invention, the cooperative working mode of the hole making device and the seed metering device is comprehensively considered, and the seed metering success rate of seeds with small and medium particle sizes can be obviously improved through simulation optimization design, so that the seed filling is stable, and the seed metering is uniform.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural machinery design, and in particular to a pulse jet-assisted membrane precision seeding device based on CFD-EDM and a design method thereof. Background Art

[0002] In modern agricultural production, efficient and accurate sowing technology has a decisive impact on the quality and yield of crops. In facility agriculture, small and medium-sized seeds are mainly planted by manual broadcasting, with uneven planting density, and tedious manual thinning work is required after the seeds emerge, which has problems such as high labor intensity, poor sowing uniformity, and low seed survival rate. Since small-sized seeds are small, light and easily damaged, pneumatic seeders are widely used in the field of precision sowing of small and medium-sized seeds. However, pneumatic seeders and supporting facilities are complex in structure and bulky in size, and are not suitable for facility agriculture.

[0003] Chinese invention patent: Publication number is "CN117918089A", title is "A small-particle seed precision seeder", which discloses a small-particle seed precision seeder, including a cleaning seed box, the bottom of which is detachably connected to a cover plate, and also includes: a water storage chamber opened in the cleaning seed box, wherein the water storage chamber is filled with water for sorting seeds, and the cover plate is rotatably connected to a rotating shaft 1. This technical solution utilizes the buoyancy of water in the water storage chamber to sort seeds, so that shrunken seeds and impurities can float upward under the buoyancy of water, thereby sorting out seeds with full particles, improving the survival rate of seeds during sowing, and during sowing, the water continuously sprayed by the water nozzle can increase the falling speed of seeds when the seeds are discharged through the discharge end of the sowing tube, so that the seeds discharged from the sowing tube can be embedded in the soil, and the seeds can be covered, further improving the survival rate of seeds. However, since this technical solution only considers the sowing method of the seeder and does not consider the hole-making function of the hole-making device, it cannot solve the problems of unstable seed filling and uneven seeding.

[0004] Chinese invention patent: Publication number is "CN117016114A", and the name is "A seeding device and method based on air pressure detection and air flow disturbance correction", which discloses a seeding device and method based on air pressure detection and air flow disturbance correction, including an air chamber shell, a sowing shell, a seed box, a seeding shaft, a seed suction disc, an air pressure detection device, and an air flow disturbance correction device: the seed suction disc is provided with a plurality of suction holes for adsorbing seeds: the air pressure detection device is used to detect the air pressure data of the suction holes and identify whether the suction holes adsorb seeds normally: the air flow disturbance correction device is used to blow air to disturb the seeds that are not adsorbed normally, so as to promote the seeds to maintain normal adsorption in the suction holes. This technical solution can detect the air pressure at the suction holes, identify whether the suction holes adsorb seeds normally, and when it is identified that the suction holes are adsorbing seeds abnormally, the seeds on the suction holes are disturbed by positive pressure airflow, so as to promote the seeds to maintain normal adsorption in the suction holes, thereby correcting the adsorption state of the seeds, ensuring that one suction hole can better adsorb one seed, and thus improving the sowing accuracy. However, this technical solution performs negative pressure adsorption on each seed when sowing, which may not only cause damage to small and medium-sized seeds but also increase energy consumption and cause waste. At the same time, this technical solution only considers the sowing method of the seeder, but does not consider the hole-making function of the hole-making device, and thus cannot solve the problems of unstable seed filling and uneven seed arrangement. Summary of the invention

[0005] In order to solve the problems of unstable seed filling, uneven seeding and small and medium-sized seeds being easily destroyed due to negative pressure adsorption in the above-mentioned prior art, the present invention proposes a pulse jet-assisted membrane precision seeding device and design method based on CFD-EDM. The present invention has a simple structure and is easy to disassemble and assemble. The seeding of seeds of different sizes can be achieved by replacing the seeding wheel, and it has good versatility.

[0006] The present invention is realized through the following technical scheme: it comprises a hole-making device and a seed-metering device arranged in parallel, the hole-making device and the seed-metering device are fixed on a mobile device, the hole-making device comprises a base plate arranged vertically and fixedly connected to the mobile device, a motor arranged horizontally and fixed to the base plate through a bracket, a crank fixedly connected to the output end of the motor and a first connecting rod hinged to the crank, and also comprises a second connecting rod, a third connecting rod and a fourth connecting rod, the first connecting rod, the second connecting rod, the third connecting rod and the fourth connecting rod are connected end to end in sequence, the end of the fourth connecting rod is connected to a guide rod; the other end of the guide rod is fixedly connected to a drill bit by a thread; the seed-metering device comprises an outer shell composed of two square boxes vertically stacked, a seed-metering wheel passing through a circular opening in the middle of the lower box of the outer shell and mounted in the outer shell, and a blocking wheel extending into the seed-metering wheel, the two square The vertical center lines of the shaped box body do not overlap, and the box body on the upper side is offset in the direction away from the hole maker, the seed wheel is rotatably connected to the shell, and the circumferential surface of the seed wheel close to the hole maker is in contact with the inner wall of the shell. The seed wheel is a cylindrical shell with an opening at one end, and a plurality of socket holes arranged in an array along the circumferential surface direction are penetrated on the circumferential surface of the seed wheel, and a connecting shaft connected to a rotating component on the mobile device is provided at the axis of the seed wheel, and the blocking wheel extends into the seed wheel from one end of the seed wheel opening, and the outer wall of the blocking wheel is in contact with the inner wall of the seed wheel; a sowing port is provided in the center of the bottom of the shell, and a cycloid guide rail is provided at the sowing port, one end of the cycloid guide rail is provided at the sowing port at the bottom of the shell, and the other end is horizontally facing the hole maker; a jet pump is also provided at the sowing port at the bottom of the shell, and the jet pump includes a jet port, and the jet port faces the cycloid guide rail from top to bottom.

[0007] Furthermore, a limiter is sleeved on the guide rod, and the limiter is fixedly connected to the bottom plate. A baffle is also arranged near the position where the guide rod is connected to the drill bit, and the baffle is cylindrical and parallel to the guide rod.

[0008] Furthermore, a drainage plate is provided between the seeding wheel and the seeding opening at the bottom of the shell.

[0009] Furthermore, the blocking wheel is provided with a notch in the circumferential direction, and a seeding brush is provided at the notch, and the seeding brush faces the seeding wheel and is perpendicular to the circumferential surface of the seeding wheel.

[0010] Furthermore, the notch of the blocking wheel occupies one quarter of the complete circumference of the blocking wheel, and the seeding brush is arranged vertically.

[0011] Furthermore, a left slider and a right slider connected to the shell through a slide groove are provided on the side of the seeding wheel away from the hole making device.

[0012] Furthermore, the upper box body of the shell is arranged to be inclined away from the hole making device and toward the seeding wheel, and a discharge plate is arranged at the inclined position of the shell.

[0013] Furthermore, a seed cleaning brush is vertically arranged inside the upper box body of the shell, the seed cleaning brush is fixedly connected to the shell and faces the seed wheel, and the seed cleaning brush is in contact with the circumferential surface of the seed wheel.

[0014] The present invention also provides a design method for the pulse jet assisted membrane precision seeding device based on CFD-EDM applicable to the present invention, comprising the following steps:

[0015] Step 1: According to the long axis size L0 of small and medium-sized seeds, the outer diameter D and inner diameter D1 of the seed wheel are obtained in mm. The formula is as follows:

[0016]

[0017] Step 2: According to the long axis size L0, short axis size W0 and thickness H0 of small and medium-sized seeds, the formula Get the sphericity S of small and medium-sized seeds p , if the sphericity S p If it is greater than or equal to 50%, a dome-shaped cylindrical socket hole is selected; otherwise, a special-shaped socket hole is selected;

[0018] Step 3, according to the planting process of the specific seed type, the number of the eyelets in each row of the eyelets is obtained;

[0019] Step 4: According to the major axis size L0, minor axis size W0, thickness H0 of the small and medium-sized seeds and the posture restrictions of the small and medium-sized seeds in the sockets, the preliminary diameter d and preliminary depth y range of the sockets are obtained. The formula is as follows:

[0020]

[0021]

[0022] In the formula, k a is the length correction factor; k b is the width correction factor; k c is the thickness correction factor;

[0023] Step 5: Preliminarily select the adduction angle γ of the socket hole;

[0024] Step 6: According to the major axis size L0 of the small and medium-sized seeds, the depth y of the socket hole, and the friction coefficient μ between the small and medium-sized seeds and the wall of the socket hole, the formula cotθ>μ is used to obtain the initial range of the depth of the seed guide groove and the inclination angle θ;

[0025] Step 7: According to the outer diameter D of the seed wheel, the diameter d of the socket holes, the spacing d1 of the socket holes in each row, the arc length l of the seed filling area I, and the angle α occupied by the seed filling area I, the number of rows of the socket holes is obtained, and the formula is as follows:

[0026]

[0027] Step 8. According to the forward speed V, plant spacing x, and number of rows of eyelets z of the unit, the rotation speed of the seeding wheel is obtained. The formula is as follows:

[0028]

[0029] Step 9: According to the cycloid equation The center of the sowing port at the bottom of the housing is taken as the origin of the coordinate axis; the straight line passing through the origin and perpendicular to the axis of the guide rod is taken as the X-axis, and the positive direction of the X-axis is the ray direction from the origin to the axis; the straight line passing through the origin and parallel to the axis of the guide rail is taken as the Y-axis to establish a cycloid guide rail model;

[0030] Step 10: According to the bottom diameter d of the seed pile s 、Aerodynamic viscosity μ a , conveying air flow density ρ a and the seed density ρ s , and obtain the resistance coefficient partition determination value k a According to k a Query the drag coefficient partition table and take the corresponding shape correction coefficient K x , substituting into the formula, we get the theoretical suspension speed v x ; According to the theoretical suspension speed v x , and wind speed v is obtained xmax and air pump flow V a , and according to the wind speed v xmax and air pump flow V a Select the corresponding jet pump; the formula is as follows:

[0031]

[0032] Step 11. Use all the dimensional parameters obtained in steps 1 to 10 to establish a seed meter model in Solidworks software. Use the depth y of the socket hole, the diameter d of the socket hole, the inward angle γ of the socket hole, the inclination θ of the seed guide groove, and the rotation speed n of the seed wheel as adjustment variables to establish multiple simulation models. Convert the models into STL format and import them into EDEM. Select the socket depth y, socket diameter d, socket inward angle γ, seed guide groove inclination θ, and seed wheel rotation speed n of the simulation model with the highest pass rate among several simulation models as the parameters of the final seed meter.

[0033] Furthermore, the length correction coefficient k in step 4 is a The value range is 1-2, the width correction coefficient k b The value range is 1-2, and the thickness correction factor k c The value range is 1.5-3.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The invention has a simple structure and is easy to disassemble and assemble. The seeding wheel can be replaced to realize the sowing of seeds with different particle sizes, and has good versatility.

[0036] 2. The present invention optimizes the design of various parts of the socket wheel seed metering device based on the three-axis dimensions of small and medium-sized seeds in combination with SW and EDEM software, thereby solving the problems of unstable seed filling and uneven seeding of traditional mechanical seed metering devices.

[0037] 3. The present invention adds a cycloid guide rail and a pulse jet assist device at the seed dispensing port. When the hole-making device completes the drilling, the seeds fall at the entrance of the cycloid track at the same time, and with the assistance of the jet, they quickly fall into the hole. The time difference between the two is very short, thus achieving precise hole sowing of small-diameter seeds.

[0038] 4. The present invention comprehensively considers the cooperative working mode of the hole-making device and the seed-dispensing device, and through simulation optimization design, can significantly improve the success rate of seed dispensing of small and medium-sized seeds, so that the seed filling is stable and the seed dispensing is uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0040] Figure 2 It is an exploded view of the parts of the seed metering device of the present invention.

[0041] Figure 3 It is a top view of the seed metering device part of the present invention.

[0042] Figure 4 for Figure 3 AA cross-section diagram.

[0043] Figure 5 for Figure 4 Schematic diagram of the medium-jet seeding structure.

[0044] Figure 6 It is an exploded view of the seeding wheel and blocking wheel parts of the present invention.

[0045] Figure 7 It is a partially enlarged schematic diagram of the cylindrical socket hole in the present invention.

[0046] Figure 8 for Figure 7 BB cross-section diagram.

[0047] Fig. 9 It is a partial enlarged schematic diagram of the socket hole with an increased inward angle in the present invention.

[0048] Fig.10 for Fig. 9Middle DD cross-section.

[0049] Fig.11 It is a partial enlarged schematic diagram of the socket hole with the added inward angle and the seed guide groove in the present invention.

[0050] Fig.12 for Fig.11 The EE cross-section diagram also includes schematic diagrams of small and medium-sized seeds.

[0051] Fig.13 Schematic diagram of a seed in a vertical position inside a socket.

[0052] Fig.14 Schematic diagram of two seeds in the socket in a vertical state.

[0053] Fig.15 Schematic diagram of a seed in a supine position inside a socket.

[0054] Fig.16 It is a schematic diagram of two seeds in the socket in a supine position.

[0055] Fig.17 Schematic diagram of a seed in a side-lying position inside a socket.

[0056] Fig.18 It is a schematic diagram of two seeds in the socket in the side-lying position.

[0057] Indicated in the figure:

[0058] 1. Jet pump; 2. Left slider; 3. Right slider; 4. Discharge plate; 5. Cycloidal guide rail; 6. Seed wheel; 7. Housing; 8. Drainage plate; 9. Blocking wheel; 10. Seed brush; 11. Seed cleaning brush; 12. Motor; 13. Bracket; 14. Bottom plate; 15. Crank; 16. First connecting rod; 17. Second connecting rod; 18. Third connecting rod; 19. Fourth connecting rod; 20. Guide rod; 21. Stopper; 22. Drill bit; 23. Baffle; 101. Jet port; 102. Seed; 601. Eyelet; 603. Seed guide groove. DETAILED DESCRIPTION

[0059] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments thereof, which are given by way of example only with reference to the accompanying drawings.

[0060] like Figure 1 and Figure 2As shown, the present invention provides a pulse jet assisted precision seeding device on a membrane based on CFD-EDM, including a hole maker and a seed meter, the seed meter and the hole maker are arranged in parallel and fixedly connected to a mobile device, and the hole maker includes a motor 12, a bracket 13, a base plate 14, a crank 15, a first connecting rod 16, a second connecting rod 17, a third connecting rod 18, a fourth connecting rod 19, a guide rod 20, a stopper 21, a drill bit 22 and a baffle 23. The base plate 14 is vertically arranged to support the entire hole maker and install the hole maker on the mobile device. The bracket 13 is arranged parallel to the base plate 14, and is used to support the motor 12, the motor 12 is horizontally arranged, and the crank 15 is fixedly connected to the output end of the motor 12. The crank 15 is also hinged to the first connecting rod 16. The first connecting rod 16, the second connecting rod 17, the third connecting rod 18, and the fourth connecting rod 19 are connected end to end in sequence, and the end of the fourth connecting rod 19 is connected to a guide rod 20, and the limiter 21 is sleeved on the guide rod 20 and fixedly connected to the bottom plate 14. The limiter 21 is used to play a guiding role, so that the guide rod 20 moves linearly along the direction of the limiter 21. The stroke of the limiter 21 is 5mm, in order to prevent the device from being damaged or to prevent the device from damaging the cultivated land. The other end of the guide rod 20 is fixedly connected with a drill bit 22 by a thread. As a preference, the drill bit 22 is a conical drill bit, because the conical drill bit has a large hole diameter, the sizes of each hole diameter are approximately the same, and it is not easy to scratch the ground film. A baffle 23 is also provided near the position where the guide rod 20 is connected to the drill bit 22. The baffle 23 is cylindrical and parallel to the guide rod 20, and is used to ensure that the seeds fall into the hole and prevent the seeds from flying around. When the machine advances one plant spacing, the hole maker moves downward at high speed to open a hole for sowing and resets instantly, realizing direct insertion reciprocating motion, effectively avoiding the occurrence of film tearing, film picking, and misalignment of the hole and the film hole. The crank 15, the first connecting rod 16, the second connecting rod 17, the third connecting rod 18, the fourth connecting rod 19 and the guide rod 20 form a set of crank slider mechanism, and the motor 12 drives the crank 15 to make a circular motion, thereby making the guide rod 20 make a linear reciprocating motion in the limiter 21.

[0061] The seeding device includes a jet pump 1, a left slider 2, a right slider 3, a discharge plate 4, a cycloidal guide rail 5, a seeding wheel 6, a shell 7, a drainage plate 8, a blocking wheel 9, a seeding brush 10 and a seed cleaning brush 11. The shell 7 is composed of two vertically stacked square boxes. The vertical center lines of the two square boxes do not overlap, and the upper box is offset away from the hole maker. The shell 7 can also be formed in one piece. A circular opening is provided in the middle of the lower box of the shell 7 perpendicular to the two sides of the hole maker. The seeding wheel 6 is rotatably connected to the shell 7 through the circular opening on the shell 7. The seeding wheel 6 is a cylindrical shell with an opening at one end. A plurality of eyelet holes 601 are provided on the circumferential surface of the seeding wheel 6, such as Figure 2 , Figure 6 and Fig.10 As shown, the socket holes 601 are arranged in a plurality of rows along the circumferential surface of the seed wheel 6, and the number of holes in each row is determined according to the sowing requirements of the specific type of seeds. The axis of the seed wheel 6 is provided with a connecting shaft, and the connecting shaft is connected to the rotating component on the mobile device. The connecting shaft is used to transmit the power transmitted from the rotating component on the mobile device, thereby driving the seed wheel 6 to rotate. The blocking wheel 9 extends into the interior of the seed wheel 6 from one end of the opening of the seed wheel 6, and the outer wall of the blocking wheel 9 fits with the inner wall of the seed wheel 6. The blocking wheel 9 is used to prevent the seeds that fall into the socket holes on the seed wheel 6 from falling prematurely before reaching the sowing position. The blocking wheel 9 is provided with a notch in the circumference, and a seed brush 10 is provided at the notch. The seed brush 10 faces the seed wheel 6 and is perpendicular to the circumferential surface of the seed wheel 6, as shown in FIG. Figure 4 , Figure 5 and Figure 6 As shown. The notch of the blocking wheel 9 preferably occupies one quarter of the complete circumference of the blocking wheel 9, and the seeding brush 10 is preferably arranged vertically, that is, one of the starting position or the end position where the inner wall of the seeding wheel 6 and the outer wall of the blocking wheel 9 fit together is in the vertical direction. The circumferential surface of the seeding wheel 6 close to the hole-making device fits with the inner side of the outer shell 7. A sowing port is provided at the center of the bottom of the outer shell 7, and one end of the cycloid guide rail 5 is arranged at the sowing port at the bottom of the outer shell 7, and the other end is horizontally facing the hole-making device. A jet pump 1 is also provided at the sowing port at the bottom of the outer shell 7, and the jet pump 1 includes a jet port 101, and the jet port 101 faces the cycloid guide rail 5 from top to bottom, as shown. Figure 4 and Figure 5 As shown. Figure 3 and Figure 4 As shown, the left slider 2 and the right slider 3 are arranged inside the shell 7 and connected to the shell 7 through a slide groove. The left slider 2 and the right slider 3 are arranged on the side of the seed wheel 6 away from the hole maker and fit with the seed wheel 6 to ensure that the other side of the seed wheel 6 is always in contact with the inner side of the shell 7. The upper side box of the shell 7 is inclined away from the hole maker and is arranged toward the seed wheel 6. The unloading plate 4 is arranged at the inclined position of the shell 7. A seed cleaning brush 11 is also vertically arranged inside the upper side box of the shell 7. The seed cleaning brush 11 is fixedly connected to the shell 7 and faces the seed wheel 6. The seed cleaning brush 11 fits the circumferential surface of the seed wheel 6. A drainage plate 8 is also arranged between the seed wheel 6 and the sowing port at the bottom of the shell 7. The drainage plate 8 is used to guide the small and medium-sized seeds sown by the seed wheel 6 to the sowing port at the bottom of the shell 7.

[0062] like Figure 4 and Figure 5As shown, the upper box body of the shell 7, the seed wheel 6 and the discharge plate 8 are combined to form a seed filling area I, the part from the seed cleaning brush 11 to the lower box body of the shell 7 and the seed wheel 6 that are not in contact with each other forms a seed cleaning area II, the part where the lower box body of the shell 7 and the seed wheel 6 are in contact with each other forms a seed protection area III, and the part from the seed brush 10 to the discharge plate 8 forms a seed filling area IV. The seed meter starts with the entry of small and medium-sized seeds 102, and passes through the seed filling area I, seed cleaning area II, seed protection area III and seed filling area IV in sequence, and is then sown on the cultivated land. Before operation, the seeds 102 are piled up and wait in the seed filling area I; during operation, the rotating assembly drives the seeding wheel 6 to rotate through the transmission shaft, and when the socket hole 601 rotates to the seed filling area I, the seeds 102 are enclosed in the socket hole 601 under the combined action of gravity, population force and the like, and the seed filling is completed; when the socket hole 601 rotates to the seed cleaning area II, the seed cleaning brush 11 will remove the excess seeds 102 inside and outside the socket hole 601; after the socket hole 601 enters the seed protection area III, under the protection of the blocking wheel 9 and the shell 7, the seeds 102 are always in the socket hole 601; finally, when it rotates to the seed discharging area IV, the seeds 102 slide out of the socket hole 601 under the combined action of their own gravity and the seed discharging brush 10, pass through the drainage plate 8, and enter the cycloid guide rail 5. With the help of the jet pump 1, the seeds 102 pass through the cycloid guide rail 5 and finally fall into the hole, completing the entire sowing process.

[0063] Most of the parts in the present invention are made by 3D printing, so if a part is damaged, it is easy to remake it. The parts are easy to assemble and replace and repair.

[0064] The present invention also designs a design method for the pulse jet assisted membrane precision seeding device based on CFD-EDM applicable to the present invention, comprising the following steps:

[0065] Step 1: According to the long axis size L0 of small and medium-sized seeds, the outer diameter D and inner diameter D1 of the seed wheel 6 are obtained in mm. The formula is as follows:

[0066]

[0067] The seeding wheel 6 is the core component of the seeding device. The size of the seeding wheel 6 is an important factor affecting the seeding effect, and its size determines the structural dimensions of other components. In order to study the influence of the diameter of the seeding wheel 6 on the seeding time T, an equation group of the seeding time T, the sowing operation parameters, and the structural parameters of the seeding wheel 6 is established, namely:

[0068]

[0069] In the formula: T is the seed filling time (s), θ is the angle of the seed filling area (°), ω is the angular velocity of the seed wheel 6 (rad / s), n is the rotation speed of the seed wheel 6 (r / min), z is the number of holes, and s is the plant spacing (cm). The equations are sorted out to get:

[0070]

[0071] It can be seen from the above formula that the seed filling time has nothing to do with the diameter of the seeding wheel 6. Referring to the "Agricultural Machinery Design Manual", the diameter selection range of the seeding wheel 6 of the socket wheel seeding device is generally 80 to 260 mm.

[0072] When the seeds 102 reach the seeding position, they cannot fall by their own gravity, so a forced seeding device is set to solve the problem of uneven seeding. Now, a certain space is hollowed out inside the seeding wheel 6 to ensure that the entire seed filling and seed protection process is not affected after the hollowing out of the seeding wheel. The remaining radial distance ΔD of the seeding wheel 6 after hollowing out is greater than or equal to 80% of the seed long axis L0.

[0073] Step 2: According to the long axis size L0, short axis size W0 and thickness H0 of small and medium-sized seeds, the formula Get the sphericity S of small and medium-sized seeds p , if the sphericity S p If the ratio is greater than or equal to 50%, the dome-shaped cylindrical socket hole 601 is selected; otherwise, the special-shaped socket hole 601 is selected; Figure 7 and Figure 8 shown.

[0074] Step 3: According to the planting process of the specific seed type, the number of the socket holes 601 in each row of the socket holes 601 is obtained.

[0075] The combination of seeds 102 in the socket holes 601 has various shapes, and multiple seeds in one hole. The seeds 102 will squeeze each other in the socket holes 601, which is easy to block the socket holes 601, resulting in poor seeding. Therefore, the present invention selects single seed with multiple holes. According to the hole sowing planting process of a specific type of seed in the agricultural manual, the number of seeds sown in each hole is determined. The number of socket holes 601 in each row is the lower limit of the number of seeds sown in each hole to meet the sowing requirements.

[0076] Step 4: According to the major axis size L0, minor axis size W0, thickness H0 of the small and medium-sized seeds and the posture restrictions of the small and medium-sized seeds in the socket hole 601, the preliminary diameter d and preliminary depth y range of the socket hole 601 are obtained, and the formula is as follows:

[0077]

[0078] In the formula, k a is the length correction factor, ranging from 1 to 2; k b is the width correction factor, ranging from 1 to 2; k c is the thickness correction factor, ranging from 1.5-3.

[0079] like Figures 13 to 18The following are possible postures of small and medium-sized seeds in the socket hole 601. In order to ensure that there is only one small and medium-sized seed in one socket hole 601, the present invention optimizes the vertical, horizontal and sideways states of small and medium-sized seeds in the socket hole 601. The diameter d and depth y of the socket hole 601 must meet the following conditions:

[0080] In the vertical state, the depth y of the socket hole 601 should be greater than the long axis of the seed, and the diameter d should be greater than the short axis and thickness of the seed. However, reseeding should not occur in the long axis and short axis directions of the seed. Therefore, it is necessary to correct it through a correction coefficient to prevent reseeding. The formula is as follows:

[0081]

[0082] In the horizontal state, the diameter d of the socket hole 601 should be larger than the long axis and short axis of the seed, and the depth y should be larger than the thickness of the seed. However, in the thickness direction of the seed, reseeding should not occur. Therefore, a correction coefficient should be used to correct it to prevent reseeding. The formula is as follows:

[0083]

[0084] In the side-lying state, the diameter d of the socket hole 601 should be larger than the long axis and thickness of the seed, and the depth y should be larger than the short axis. However, in the short axis and thickness direction of the seed, reseeding should not occur. Therefore, a correction coefficient should be used to correct it to prevent reseeding. The formula is as follows:

[0085]

[0086] The major axis size L0, minor axis size W0, thickness H0, and length correction coefficient k of small and medium-sized seeds are a , Width correction factor k b and thickness correction factor k c , substituting into the above formula, we can obtain the preliminary diameter d and preliminary depth y range of the socket hole 601.

[0087] Step 5: Preliminarily select the adduction angle of the socket hole 601.

[0088] like Fig. 9 and Fig.10 As shown, the seeding effect is a direct reflection of the performance of the seeding device. If the portion of the socket hole 601 close to the housing 7 is cylindrical, the seeds 102 are easily stuck in the socket hole 601 during the seeding process and are not easy to fall. In order to solve this problem, the socket hole 601 is retracted by a certain angle γ. When the retraction angle γ is too large, the volume of the socket hole 601 will be reduced, affecting the seed filling. Therefore, the retraction degree γ is initially set between 0-45 degrees.

[0089] The adduction angle γ is the angle between the generatrix L1 of the cylindrical part of the socket hole 601 close to the shell 7 when there is no adduction angle and the generatrix L2 of the conical part of the socket hole 601 close to the shell 7 when there is an adduction angle. The point of the socket hole 601 on the circumferential surface of the seed wheel 6 remains unchanged before and after the adduction angle.

[0090] The center of mass of a single seed 102 in the socket 601 is selected as the coordinate point O, and an XOY coordinate system is established along the tangential and normal directions of the seed wheel 6. The force analysis of this state is performed, and the seed 102 is subjected to its own gravity G, the support force N of the socket 601 wall on the seed 102, and the friction force f of the socket 601 wall on the seed 102. To ensure that the seed 102 can fall, it means that the resultant force in the negative direction of the Y axis must be greater than 0, that is:.

[0091]

[0092] Where: μ is the friction coefficient between the seed 102 and the wall of the socket hole 601. Simplifying the above formula, G>2μN is obtained. Substituting the adduction angle γ into the formula, we can get Simplifying the above formula, we get G>2N(μcosγ-sinγ). Analysis and calculation results show that after increasing the adduction angle, the resistance of the seed 102 becomes smaller and the larger the adduction angle γ, the more conducive to seeding. However, if the adduction angle is too large, the volume of the socket hole 601 will become smaller, thereby reducing the seed filling capacity.

[0093] Step six: According to the major axis size L0 of the small and medium-sized seeds, the depth y of the socket hole 601, and the friction coefficient μ between the small and medium-sized seeds and the wall of the socket hole 601, the formula cotθ>μ is used to obtain the preliminary range of the depth of the seed guide groove 603 and the inclination angle θ.

[0094] like Fig.11 and Fig.12 As shown, the seed guiding groove 603 is a chamfer formed on the circumferential surface of the seed wheel 6 that contacts the seed 102 based on the original eyelet hole 601 .

[0095] The depth of the socket hole 601 minus the depth of the seed guiding groove 603 is y1, and y1 should be not less than 80% of the long axis dimension of the seed 102. The inclination angle of the seed guiding groove 603 is θ, which is the angle between the generatrix L1 of the socket hole 601 close to the cylindrical part of the housing 7 and the hypotenuse L3 of the seed guiding groove 603 on the EE section when there is no adduction angle.

[0096] Before starting work, the seeds 102 are in a stable state in the material box under the action of gravity. When the size of the socket hole 601 is similar to that of the seed 102, it is easy to produce arching and overhead phenomena. The seed guide groove 603 is provided on the socket hole 601 to effectively increase the contact area between the socket hole 601 and the seed 102; and during the rotation of the seed wheel 6, the seed 102 can slide into the socket hole 601 along the seed guide groove 603, which is conducive to seed filling. If the inclination angle of the seed guide groove 603 is too small, the seed filling capacity will not be significantly improved, but if it is too large, it will easily cause reseeding. Therefore, according to the major axis size L0 of the small and medium-sized seeds of the seeds 102, the depth y of the socket hole 601, and the friction coefficient μ between the small and medium-sized seeds and the wall of the socket hole 601, the seed guide groove is designed. To ensure that the seed 102 does not fall out of the hole in a vertical state, that is, the depth y1 of the socket hole 601 minus the depth of the seed guide groove 603 is not less than 80% of the long axis size of the seed 102, the length of the seed guide groove 603 in the depth direction of the socket hole 601 is designed to be a fixed value of 0.5 mm. The setting of the inclination angle of the seed guide groove 603 needs to ensure that the component force of the gravity on the seed 102 is greater than the friction force, that is, cotθ>μ. The preliminary range of the inclination angle θ of the seed guide groove 603 is obtained.

[0097] Step 7: According to the outer diameter D of the seed wheel 6, the diameter d of the socket holes 601, the spacing d1 of the socket holes 601 in each row, the arc length l of the seed filling area I, and the angle α occupied by the seed filling area I, the number of rows of the socket holes 601 is obtained, and the formula is as follows:

[0098]

[0099] The seeding device is driven by a speed-adjustable motor. The number of sockets 601 on the seeding wheel 6 is not affected by the ground wheel size and plant spacing, but is only related to the outer diameter D of the seeding wheel 6, the diameter d of the sockets 601, the spacing d1 of the sockets 601 in each row, and the arc length l of the seeding area I. In order to prevent seed confusion during the seeding process, the number of rows z of the sockets 601 can be expressed as:

[0100]

[0101] When the rotation speed of the seed wheel 6 is constant, the more rows of the socket holes 601 there are, the faster the forward speed of the unit is and the higher the efficiency is. Therefore, z takes the maximum value that satisfies the above formula.

[0102] Step 8: According to the forward speed V of the unit, the plant spacing x, and the number of rows z of the eyelets 601, the rotation speed of the seeding wheel 6 is obtained, and the formula is as follows:

[0103]

[0104] Step 9: According to the cycloid equation The center of the sowing port at the bottom of the shell 7 is taken as the origin of the coordinate axis; the straight line passing through the origin and perpendicular to the axial direction of the guide rod 20 is taken as the X-axis, and the positive direction of the X-axis is the ray direction from the origin to the axis; the straight line passing through the origin and parallel to the axial direction of the guide rail 20 is taken as the Y-axis to establish a cycloid guide rail 5 model.

[0105] The key to precision hole seeding is whether the hole making time can be fully matched with the seed 102 falling time. In the experiment, it was found that due to the influence of factors such as environment and equipment accuracy, it is difficult for the seed 102 to fall accurately into the hole, so a cycloid guide 5 and a jet pump 1 are added to the seeding port at the bottom of the shell 7. The cycloid equation is

[0106] When the hole making device completes the drilling work, the seeds 102 fall out of the seed wheel 6 under the action of the seed cleaning brush 10, and reach the entrance of the cycloid guide 5 through the drainage plate 8. In order to make the seeds 102 reach the hole as soon as possible after the drilling is completed, an air jet 101 is provided at the entrance of the cycloid guide 5. Because the tangent of the cycloid at the entrance is vertical, the air jet 101 is close to the drainage plate 8 and placed vertically. Under the action of the air jet, the seeds 102 pass through the cycloid guide 5 quickly, and this time can be ignored, thereby completing the precise hole sowing of the seeds.

[0107] Step 10: According to the bottom diameter d of the seed pile s , Aerodynamic viscosity μ a , conveying air flow density ρ a and the seed density ρ a , and obtain the resistance coefficient partition determination value k a According to k a Query the drag coefficient partition table and take the corresponding shape correction coefficient K x , substituting into the formula, we get the theoretical suspension speed v x ; According to the theoretical suspension speed v x , and wind speed v is obtained xmax and air pump flow V a , and according to the wind speed v xmax and air pump flow V a Select the corresponding jet pump. The formula is as follows:

[0108]

[0109] Suspension velocity is one of the important parameters for determining wind speed. Its expression is determined by the resistance coefficient determination value and is affected by the physical properties of the seed particle size, density, etc. The resistance coefficient partition determination value k a and the theoretical suspension speed v x satisfy:

[0110]

[0111] Where, ka is the resistance coefficient partition determination value; d s is the bottom diameter of the seed pile, in mm; μ a is the air dynamic viscosity; ρ a is the transport air flow density; ρ s is the seed density; v x is the theoretical suspension speed, in m / s; K x is the shape correction factor.

[0112] Substitute the specific seed material characteristic parameters into the above formula to obtain the resistance coefficient partition determination value k a , according to k a Query the drag coefficient partition table and take the corresponding shape correction coefficient K x , we can get the theoretical suspension speed v x The appropriate wind speed can ensure stable seed transportation and reduce power consumption and seed damage rate. The upper limit of the stable wind speed of the track should meet the stable suspension transportation of seeds. The upper limit of the wind speed is 1.5 times the theoretical suspension speed. xmax and air pump flow V a Should meet:

[0113]

[0114] In the formula, v xmax is wind speed, unit is m / s; d d V is the diameter of the jet hose, in mm; a is the air pump flow rate, unit: m 3 / s.

[0115] Step 11. Use all the dimensional parameters obtained in steps 1 to 10 to establish a seed meter model in Solidworks software. Use the depth y of the socket hole 601, the diameter d of the socket hole 601, the inward angle γ of the socket hole 601, the inclination θ of the seed guide groove 603, and the rotation speed n of the seed wheel 6 as adjustment variables to establish multiple simulation models. After converting the models into STL format, import them into EDEM. Select the depth y of the socket hole 601, the diameter d of the socket hole 601, the inward angle γ of the socket hole 601, the inclination θ of the seed guide groove 603, and the rotation speed n of the seed wheel 6 of the simulation model with the highest pass rate among several simulation models as the parameters of the final seed meter.

[0116] Embodiment 1:

[0117] Taking spinach seeds as an example, various physical properties of spinach seeds are substituted into the design method of the present invention to further explain the design method of the present invention.

[0118] Step 1: Spinach is planted in a narrow row and densely planted pattern, so the overall structure of the seed wheel 6 should not be too large. After comprehensive consideration, the outer diameter D of the seed wheel 6 is 80 mm. The long axis size L0 of spinach seeds is 2.64 mm. Substituting it into the formula The inner diameter D1 of the seed wheel 6 is obtained to be ≤77.885, which is 77 mm.

[0119] Step 2: Substitute the spinach seed's major axis dimension L0 = 2.64 mm, minor axis dimension W0 = 2.42 mm, and thickness H0 = 1.71 mm into the formula Get the sphericity S of spinach seeds p Therefore, the shape of the socket hole 601 is preliminarily designed to be a dome-shaped column.

[0120] Step 3: According to the hole-seeding planting process of spinach, 3-5 seeds are sown in each hole, so the number of the socket holes 601 in each row of the seed wheel 6 is 3.

[0121] Step 4: Set the spinach seed’s major axis dimension L0 = 2.64 mm, minor axis dimension W0 = 2.42 mm, thickness H0 = 1.71 mm, and length correction factor k a is 1.2, width correction factor k b is 1.5 and the thickness correction factor k c Substituting 2 into the formula, the preliminary parameter range of the socket hole 601 is obtained as follows:

[0122]

[0123] Step 5: Preliminarily select the adduction angle range as 0-20°.

[0124] Step six, according to the major axis dimension L0=2.64mm of the spinach seeds and the range of the depth y of the socket hole 601, determine that the length of the seed guide groove 603 in the depth direction of the socket hole 601 is a fixed value of 0.5mm; substitute the friction coefficient μ of 0.45 between the small and medium-sized seeds and the wall of the socket hole 601 into the formula, and obtain the inclination angle θ of the seed guide groove 603 <67.22°.

[0125] Step seven, substitute the outer diameter D of the seed wheel 6 = 80 mm, the maximum diameter d of the socket holes 601 as 3.42 mm, the spacing d1 of the socket holes 601 in each row, the arc length l of the seed filling area I and the angle α occupied by the seed filling area I as 60° into the formula, and obtain the number of rows of socket holes 601 z < 10.31. When the rotation speed of the seed wheel is constant, the more rows of socket holes 601, the faster the forward speed of the unit and the higher the efficiency, so z is taken as 10.

[0126] Step 8: Taking into account the operation efficiency and seeding performance, the rotation speed of the seeding wheel 6 is determined to be 10-40 r / min.

[0127] Step 9: According to the cycloid equation The center of the sowing port at the bottom of the shell 7 is taken as the origin of the coordinate axis; the straight line passing through the origin and perpendicular to the axial direction of the guide rod 20 is taken as the X-axis, and the positive direction of the X-axis is the ray direction from the origin to the axis; the straight line passing through the origin and parallel to the axial direction of the guide rail 20 is taken as the Y-axis to establish a cycloid guide rail 5 model.

[0128] Step 10: According to the bottom diameter d of the seed pile s 、Aerodynamic viscosity μ a 18.1×10 -6 Pa·s, conveying air flow density ρ a 1.205kg / m 3 and the seed density ρ s 1180kg / m 3 , and obtain the resistance coefficient partition determination value k a =28.42; according to k a Query the drag coefficient partition table and take the corresponding shape correction coefficient K x =1.1, substitute into the formula, and get the theoretical suspension speed v x =8.639m / s; According to the theoretical suspension speed v x , and wind speed v is obtained xmax =12.95m / s and air pump flow rate V a =14.04L / min, and according to the wind speed v xmax and air pump flow V a Select the corresponding jet pump. Considering the installation location and working environment, the jet pump model JS500U01 is selected with a flow rate of 15L / min.

[0129] Step 11: Use all the dimension parameters obtained in Steps 1 to 10 to build a seed meter model in Solidworks software, with the depth y of the socket hole 601 and the diameter d of the socket hole 601 in the range of The retraction angle γ of the socket hole 601 is 0-20°, the inclination angle θ of the seed guide groove 603 is <67.22°, and the rotation speed n of the seed wheel 6 is 10-40r / min as adjustment variables, and multiple simulation models are established. The models are converted into STL format and imported into EDEM for simulation analysis. Table 1 is the EDEM simulation parameter table, and Table 2 is the orthogonal experimental results of the retraction angle γ, inclination angle θ and rotation speed n:

[0130] Table 1 EDEM simulation parameters

[0131]

[0132]

[0133] Table 2

[0134]

[0135] From Table 2, it can be seen that the best combination parameters are: γ = 5°, θ = 60°, n = 24r / min. Through the single factor analysis of the diameter d of the socket hole 601, it is found that d = 3mm; through the single factor analysis of the depth y of the socket hole 601, it is found that y = 3.1mm is the best combination. Therefore, γ = 5°, θ = 60°, n = 24r / min, d = 3mm and y = 3.1mm are used as output to produce the seed meter.

[0136] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A pulse jet-assisted precision seeding device on a membrane based on CFD-EDM, comprising a hole-making device and a seed-seeding device arranged in parallel, wherein the hole-making device and the seed-seeding device are fixed on a mobile device, and characterized in that: The hole making device comprises a base plate (14) arranged vertically and fixedly connected to the moving device, a motor (12) arranged horizontally and fixed to the base plate (14) via a bracket (13), a crank (15) fixedly connected to the output end of the motor (12), and a first connecting rod (16) hinged to the crank (15), and further comprises a second connecting rod (17), a third connecting rod (18) and a fourth connecting rod (19), wherein the first connecting rod (16), the second connecting rod (17), the third connecting rod (18), the fourth connecting rod (19) and the fourth connecting rod (19) are connected to the base plate (14) and the second connecting rod (17), the third connecting rod (18), the fourth connecting rod (19) and the fourth connecting rod (19). Four connecting rods (19) are connected end to end in sequence, and the end of the fourth connecting rod (19) is connected to a guide rod (20); the other end of the guide rod (20) is fixedly connected to a drill bit (22) by means of a thread; the seeding device comprises a housing (7) composed of two vertically stacked square boxes, a seeding wheel (6) passing through a circular opening in the middle of the lower box of the housing (7) and mounted in the housing (7), and a blocking wheel (9) extending into the seeding wheel (6); the vertical center lines of the two square boxes of the housing (7) do not overlap, The upper box body is offset in a direction away from the hole-making device, the seed-discharging wheel (6) is rotatably connected to the outer shell (7), and the circumferential surface of the seed-discharging wheel (6) close to the hole-making device is in contact with the inner wall of the outer shell (7), the seed-discharging wheel (6) is a cylindrical shell with an opening at one end, and a plurality of socket holes (601) arranged in an array along the circumferential surface are penetrated on the circumferential surface of the seed-discharging wheel (6), and a connecting shaft connected to a rotating component on the mobile device is provided at the axis of the seed-discharging wheel (6), and the blocking wheel (9) extends from the open end of the seed-discharging wheel (6). The outer wall of the blocking wheel (9) is fitted into the interior of the seeding wheel (6); a sowing opening is provided at the center of the bottom of the housing (7); a cycloidal guide rail (5) is provided at the sowing opening; one end of the cycloidal guide rail (5) is provided at the sowing opening at the bottom of the housing (7); and the other end is horizontally directed toward the hole-making device; an air jet pump (1) is also provided at the sowing opening at the bottom of the housing (7); the air jet pump (1) comprises an air jet port (101), and the air jet port (101) is directed from top to bottom toward the cycloidal guide rail (5).

2. The pulse jet assisted membrane precision seeding device based on CFD-EDM according to claim 1 is characterized in that: The guide rod (20) is also sleeved with a stopper (21), the stopper (21) is fixedly connected to the bottom plate (14), and a baffle (23) is also provided near the position where the guide rod (20) is connected to the drill bit (22), the baffle (23) is cylindrical and parallel to the guide rod (20).

3. The pulse jet assisted membrane precision seeding device based on CFD-EDM according to claim 2 is characterized in that: A drainage plate (8) is also provided between the seeding wheel (6) and the seeding opening at the bottom of the housing (7).

4. The pulse jet assisted membrane precision seeding device based on CFD-EDM according to claim 3 is characterized in that: The blocking wheel (9) is provided with a notch in the circumferential direction, and a seeding brush (10) is provided at the notch. The seeding brush (10) faces the seeding wheel (6) and is perpendicular to the circumferential surface of the seeding wheel (6).

5. The pulse jet assisted membrane precision seeding device based on CFD-EDM according to claim 4 is characterized in that: The notch of the blocking wheel (9) occupies one quarter of the complete circumference of the blocking wheel (9), and the seeding brush (10) is arranged vertically.

6. The pulse jet assisted membrane precision seeding device based on CFD-EDM according to claim 4 is characterized in that: A left slider (2) and a right slider (3) connected to the outer shell (7) via a slide groove are provided in close contact with the seeding wheel (6) on the side away from the hole making device.

7. The pulse jet assisted membrane precision seeding device based on CFD-EDM according to claim 4 is characterized in that: The upper box body of the outer shell (7) is arranged to be inclined away from the hole-making device and toward the seed-discharging wheel (6), and a discharge plate (4) is arranged at the inclined position of the outer shell (7).

8. The pulse jet assisted membrane precision seeding device based on CFD-EDM according to claim 4 is characterized in that: A seed cleaning brush (11) is also vertically arranged inside the upper box body of the outer shell (7). The seed cleaning brush (11) is fixedly connected to the outer shell (7) and faces the seeding wheel (6). The seed cleaning brush (11) is in contact with the circumferential surface of the seeding wheel (6).

9. A design method for a pulse jet assisted membrane precision seeding device based on CFD-EDM applicable to any one of claims 4 to 8, characterized in that: The steps include: Step 1: According to the long axis size L0 of small and medium-sized seeds, the outer diameter D and inner diameter D1 of the seed wheel (6) are obtained in mm, and the formula is as follows: Step 2: According to the long axis size L0, short axis size W0 and thickness H0 of small and medium-sized seeds, the formula Get the sphericity S of small and medium-sized seeds p , if the sphericity S p If the percentage is greater than or equal to 50%, a dome-shaped cylindrical eyelet (601) is selected; otherwise, a special-shaped eyelet (601) is selected; Step 3: according to the planting process of the specific seed type, the number of the eyelet holes (601) in each row of the eyelet holes (601) is obtained; Step 4: According to the major axis size L0, minor axis size W0, thickness H0 of the small and medium-sized seeds and the posture restrictions of the small and medium-sized seeds in the socket hole (601), the preliminary diameter d and preliminary depth y range of the socket hole (601) are obtained, and the formula is as follows: In the formula, k a is the length correction factor; k b is the width correction factor; k c is the thickness correction factor; Step 5: Preliminarily select the adduction angle γ of the socket hole (601); Step 6: According to the major axis size L0 of the small and medium-sized seeds, the depth y of the socket hole (601), and the friction coefficient μ between the small and medium-sized seeds and the wall of the socket hole (601), the depth of the seed guide groove (603) and the preliminary range of the inclination angle θ are obtained by the formula cotθ>μ; Step 7: According to the outer diameter D of the seed wheel (6), the diameter d of the socket holes (601), the spacing d1 of the socket holes (601) in each row, the arc length l of the seed filling area I, and the angle α occupied by the seed filling area I, the number of rows of the socket holes (601) is obtained, and the formula is as follows: Step 8: According to the forward speed V of the unit, the plant spacing x, and the number of rows z of the eyelets (601), the rotation speed of the seeding wheel (6) is obtained, and the formula is as follows: Step 9: According to the cycloid equation The center of the sowing opening at the bottom of the housing (7) is taken as the origin of the coordinate axis; a straight line passing through the origin and perpendicular to the axial direction of the guide rod (20) is taken as the X-axis, and the positive direction of the X-axis is the direction of the ray from the origin to the axis; and a straight line passing through the origin and parallel to the axial direction of the guide rail (20) is taken as the Y-axis to establish a cycloid guide rail (5) model; Step 10: According to the bottom diameter d of the seed pile s 、Aerodynamic viscosity μ a , conveying air flow density ρ a and the seed density ρ s , and obtain the resistance coefficient partition determination value k a According to k a Query the drag coefficient partition table and take the corresponding shape correction coefficient K x , substituting into the formula, we get the theoretical suspension speed v x ; According to the theoretical suspension speed v x , and get the wind speed v xmax and air pump flow V a , and according to the wind speed v xmax and air pump flow V a Select the corresponding jet pump; the formula is as follows: Step 11, using all the dimensional parameters obtained in steps 1 to 10 to establish a seed meter model in Solidworks software, using the depth y of the socket hole (601), the diameter d of the socket hole (601), the inward angle γ of the socket hole (601), the inclination angle θ of the seed guide groove (603), and the rotation speed n of the seed wheel (6) as adjustment variables, to establish multiple simulation models, and converting the models into STL format and importing them into EDEM, and selecting the depth y of the socket hole (601), the diameter d of the socket hole (601), the inward angle γ of the socket hole (601), the inclination angle θ of the seed guide groove (603), and the rotation speed n of the seed wheel (6) of the simulation model with the highest pass rate among the multiple simulation models as the parameters of the final seed meter.

10. The design method of the pulse jet assisted membrane precision seeding device based on CFD-EDM according to claim 9, characterized in that: The length correction coefficient k in step 4 a The value range is 1-2, the width correction coefficient k b The value range is 1-2, and the thickness correction factor k c The value range is 1.5-3.

Images