A biomimetic helical directional seed casting device

Abstract

The present application relates to the field of agricultural equipment and precision seeding technology, and relates to a bionic spiral directional seed dropping device, which comprises an air suction seed dropping device, a preliminary directional device, a seed spiral directional device, a directional conveying device, a seed guide groove and a transmission mechanism; the random posture input is reduced through two-stage gap arrangement at the end of the seed dropping disc; the forward convergence of the tip is realized through throat discrimination of the spiral directional track, torque triggering of the offset guide rib, and locking of the tip capture groove; the rebound reversal is inhibited through point constraint and flexible damping of the brush fixing wheel, and the anisotropic friction characteristics of the one-way micro-spine of the locking section; the posture is maintained and conveyed through low-friction sliding of the bottom surface, side wall friction limiting, and division of the double-layer directional brush belt in the directional conveying section; and finally, the tip is downward and the embryo surface is close to the groove wall in the wedge-shaped turning track, so as to meet the directional seeding demand under the condition of high-speed and dense planting.

Description

Technical Field

[0001] This invention relates to the field of agricultural equipment and precision seeding technology, specifically to the design of a corn seed orientation control and orientation delivery mechanism, and more particularly to a corn seed orientation device for seeding operations and its spiral orientation, elastic compression and biomimetic unidirectional friction track structure, used to achieve seed posture convergence, maintenance and orientation into the furrow during the conveying process. Background Technology

[0002] Sowing, as a crucial step in agricultural production, directly impacts crop emergence uniformity, population evenness, and yield stability through its operational precision. Currently, precision sowing parameters for maize primarily focus on single-seed rate, plant spacing, and sowing depth. However, under conditions of high-speed, dense planting and field vibration, seeds frequently collide, bounce, roll, and slip during the seed delivery path, leading to randomized seed placement posture and difficulty in ensuring consistent seed placement, resulting in low sowing quality. Because maize kernels exhibit significant geometric and structural anisotropy—with differences in morphology and frictional contact characteristics between the pointed and blunt ends, and between the embryonic and dorsal surfaces—different placement postures alter the soil covering force and seed-soil contact state, thus affecting the initial direction of radicle extension, emergence speed, and uniformity. According to agronomic requirements, sowing with the radicle facing down and the embryonic surface facing the adjacent row achieves the best sowing results. Therefore, based on traditional seed metering and placement precision, developing methods to control seed posture convergence before furrow placement and the consistency of furrow placement posture has significant engineering value.

[0003] The core of corn seed orientation technology lies in achieving controllable adjustment and maintenance of the seed's posture through mechanical constraints and flexible drive without significantly increasing the risk of damage and blockage. This allows the seed to enter the furrow stably in a preset posture, providing crucial support for high-speed and high-quality sowing.

[0004] Existing patented technologies for corn seed orientation mainly include spiral coil orientation, offline shaping orientation, fully constrained carrying orientation, and media-induced orientation. Spiral coil orientation introduces randomly positioned seeds output from the seed metering device into the spiral pipe path. Through path geometric constraints and the forces of airflow or centrifugation, the seeds are gradually oriented and enter the soil with an orientation such as "point down and embryo surface facing the adjacent row." Spiral coil orientation has high compatibility with seeders and can be used as a seeding device for seeders. However, it usually relies on the coordination of airflow organization, coil structure, and the wedge-shaped groove capture structure below. The system is sensitive to installation space, air source, and path layout, and places higher demands on cycle matching and secondary disturbance control under high-speed operation. Offline seed setting and orientation achieves directional seeding by mechanized constraint and clamping positioning of the germ end of maize kernels. This technology employs a special mechanical structure distinct from conventional agricultural machinery, serving as an independent pre-sowing seed preparation and orientation tool. It departs from the continuous dynamic main operation line of modern seeders ("ditching-sowing-covering"), and is typically complex in transmission and bulky in size, making it difficult to physically match and integrate with existing high-speed field seeders. It cannot be directly applied to the real-time directional seeding stage within the seed furrow. Media-induced orientation utilizes electromagnetic vibration, electrostatic adsorption, and other methods to achieve directional seeding. Its orientation mechanism is relatively clear, but the system is highly complex and heavily dependent on environmental and operational conditions, making it difficult to achieve low-cost, high-reliability, high-speed integration and speed matching on conventional field seeders. Fully constrained seed-carrying orientation achieves stable spatial isolation and speed control by capturing and carrying seeds, thereby maintaining consistent plant spacing and reducing the impact of row unit dynamics on the seeding point. However, this technology focuses on seed transport and cannot fundamentally solve the orientation requirements of maize seeds. Furthermore, a reliable attitude locking mechanism is still needed after orientation to suppress secondary tumbling and rebound reversal.

[0005] Therefore, there is an urgent need to design a corn seed directional dispensing device that can be integrated with existing seeders, matched for high-speed operations, and has attitude convergence and locking closed-loop capabilities. Summary of the Invention

[0006] The purpose of this invention is to address the technical shortcomings of existing corn seed orientation devices, such as difficulty in integrating with existing planter row units, difficulty in matching high-speed planting rhythms, poor orientation effect, and easy secondary disturbance of posture. This invention provides a biomimetic spiral orientation seeding device that achieves rapid convergence and stable maintenance of seed posture through a continuous closed loop of "initial posture adjustment in the seed tray - forced orientation via spiral orientation track - orientation conveying posture locking - final orientation via wedge-shaped furrow entry". This improves the consistency of furrow entry posture and sowing quality under high-speed dense planting conditions.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows.

[0008] A biomimetic spiral directional seed dispensing device includes an air suction seed meterer, which includes a negative pressure chamber shell and a seed chamber shell. The negative pressure chamber shell is connected to an air circuit system. A seed metering disc is rotatably connected inside the seed chamber shell. The seed metering disc has multiple air suction holes arranged along its circumference, which communicate with the negative pressure chamber shell as seed carrying areas. The improvement is that it also includes a preliminary orientation device, a seed spiral orientation device, an orientation conveying device, a seed guide groove, and a transmission mechanism. The preliminary orientation device is fixed inside the seed chamber shell and corresponds to the rotation trajectory of the air suction hole on the seed metering tray. The preliminary orientation device is used to control the rolling of the seeds on the seed metering tray, so that the seeds in the edge adsorption or spot adsorption state are controlled to roll, gradually transforming them into surface adsorption and maintaining the surface adsorption state into the seed spiral orientation device. The seed spiral orientation device is fixed to the seed chamber shell and connected to the seed unloading area outlet of the seed chamber shell. The seed spiral orientation device is used to control the seeds to gradually transition from free fall to a constrained sliding state, and to complete the attitude adjustment with the tip facing forward and to transport them stably. The directional conveying device is fixed to the seed chamber shell and connected to the outlet end of the seed spiral directional device. The directional conveying device is used to convey seeds with a uniform posture to the seed guide groove. The seed guide groove is installed at the outlet end of the directional conveying device. The seed guide groove is used to lock the final discharged seed into the bottom of the groove with the tip facing down. The transmission mechanism is installed on the seed chamber shell and is used to connect with the seed spiral orientation device and the orientation conveying device to achieve the rhythm matching of the spiral orientation and the orientation conveying.

[0009] As a preferred embodiment of the present invention, the preliminary orientation device includes: a concave reversing plate fixedly connected to the seed chamber shell, and a positioning plate fixedly connected to the bottom of the concave reversing plate, wherein the concave reversing plate extends a concave arc-shaped finishing surface along the radial direction of the air suction hole of the seed metering disc, the concave reversing plate is S-shaped, the concave arc-shaped finishing surface is the lower half of the S-shape, the lower half of the S-shape extends a concave arc-shaped finishing surface along the radial direction of the air suction hole of the seed metering disc, and the concave arc-shaped finishing surface and the surface of the seed metering disc form a first finishing gap g in the seed carrying area. s The positioning plate has a limiting surface extending tangentially along the air suction hole of the seed metering disc. The positioning plate is in the shape of two stepped plates, with the inner side of the upper stepped surface being a circular arc with tangent ends, and the lower stepped surface being a plane. The limiting surface forms a second tidying gap g with the surface of the seed metering disc. o Furthermore, the concave reversing plate and the positioning plate are arranged sequentially along the rotation direction of the seed metering disc to form a continuous sorting channel, so that the seeds in the edge-adsorbed or point-adsorbed state are controlled to roll into surface-adsorbed state at the air suction hole and the secondary flipping is suppressed. First sorting gap g sWith the second cleaning gap g o satisfy: g s =(0.65~0.90) T, g o =(0.80~1.05) T, g o >g s ; Where T represents the characteristic thickness of the corn seed, in mm; The radius of the concave arc finishing surface is 1.0 to 3.0 times the radius of the air suction hole, and the working area of ​​the concave reversing plate along the circumference of the seed metering disc covers 10° to 25° of the rotation angle of the seed metering disc. The radius R of the concave arc finishing surface s satisfy: R s =(1.0~3.0) R p ; Where R p The radius of the air suction hole in the seed metering disc is in mm. The plane (limiting surface) of the positioning plate is parallel to or offset at 5° from the tangential direction of the seed metering disc, and the junction of the positioning plate and the concave reversing plate is provided with a rounded transition to avoid seed rebound and secondary flipping caused by the step.

[0010] In a preferred embodiment of the present invention, the seed spiral orientation device includes a spiral orientation housing, a spiral orientation track, a seed brush wheel, a seed orientation composite wheel, a seed receiving track, and a connecting slope. The spiral orientation housing is fixedly connected to the seed chamber housing. The spiral orientation track is formed on the inner arc surface (inner wall) of the spiral orientation housing and extends along the circumference of the spiral orientation housing. The seed orientation composite wheel is rotatably connected to the seed brush wheel within the spiral orientation housing and arranged tangentially to the spiral orientation track. The seed orientation composite wheel is formed by a spring orientation wheel and a brush fixing wheel coaxially fixedly connected via an inner fixing plate and an outer fixing plate to form an integral structure, thereby oriented the spiral orientation. The seeds within the directional track are simultaneously provided with variable compliant normal compression and stable tangential friction drive, enabling the seeds to complete their forward-pointing posture adjustment and stable transport within the spiral directional track. The seed-accepting track is located at the entrance of the spiral directional track and is positioned between the seed brush wheel and the seed-directing composite wheel, arranged tangentially to both. The connecting slope is located between the exit of the spiral directional track and the entrance of the directional conveying device, used to smoothly connect the seed exit process of the spiral directional track to the lower directional conveying device, while buffering seed posture disturbances; thereby transitioning the seeds from free fall to a constrained sliding state, thus reducing bouncing and random tumbling.

[0011] As a preferred embodiment of the present invention, the brush fixing wheel includes intermittent annular brushes and rubber protrusions embedded in the middle of the brushes. The brushes and rubber protrusions are arranged alternately. The brushes provide continuous flexible support and damping, while the rubber protrusions provide stable support. The rubber protrusions can achieve discrete point constraint and anti-rebound anchoring, thereby improving the attitude retention capability after orientation. The inner fixing plate and the outer fixing plate are connected by a tie rod end plate and screws, so that the spring orientation wheel and the brush fixing wheel are coaxially locked and rotate synchronously.

[0012] The spring-guided wheel includes a wheel body and an elastic clamping element mounted on the wheel body. The wheel body consists of a paddle tip and a spring support. Multiple spring connecting holes (threaded holes) are evenly distributed on the circumferential surface of the annular spring support. The paddle tip is fixed to the circumferential surface of the spring support and is arranged alternately with the spring connecting holes. The outer diameter of the annular ring (concentric with the spring support) formed by the multiple paddle tips is consistent with the inner diameter of the helical directional track, ensuring that the paddle tip forms a uniform diameter following and stable contact with the inner wall of the channel during operation. This provides a continuous tangential bearing surface for the seed and reliable geometric guidance when the seed slips, suppressing the clamping failure caused by wheel slippage. The paddle tip and the inner wall surface of the helical directional housing achieve... The travel limit is used to restrict the maximum pressing stroke to prevent overpressure from damaging the seeds or causing channel blockage. The elastic clamping element is used to adjust the pre-tightening pressing amount, so that the spring directional wheel can establish sufficient normal clamping force under different seed sizes, coating thicknesses, and friction conditions, ensuring effective frictional contact between the seeds and the spiral directional track wall. The elastic clamping element consists of multiple ring-shaped paddles and springs. The lower end of the spring is fixed to the spring connecting hole of the spring support and is arranged alternately with the paddle top finger. The paddle is fixed to the upper end of the spring. A threaded hole is provided on the side of the paddle near the spring. The upper end of the spring is fixed in the threaded hole. The paddle supports the seeds in the spiral directional track under the support of the spring.

[0013] The seed brushing wheel is located at the entrance of the spiral directional track. The seed brushing wheel and the seed directional composite wheel form a clamping and feeding cooperation to apply tangential disturbance to the seeds in the stable section of the entrance and reduce accumulation and jamming. The seed brushing wheel includes: a seed brushing wheel body, and an outer end cover and an inner end cover located on both sides of the seed brushing wheel body and fixedly connected to the seed brushing wheel body on the same axis to form an integral structure.

[0014] As a preferred embodiment of the present invention, the spiral directional track is divided into an inlet stabilization section, a directional turning section, and a locking and retaining section; the slot width of the inlet stabilization section is 9.2 mm, and the slot width of the locking and retaining section is 8.8 mm. The cross-section of the spiral directional track is groove-shaped. Under the pressure of the spring directional wheel, the groove-shaped spiral directional track forms a stable contact side. The bottom radius of the spiral directional track is 4.2mm, the gentle side wall angle is 35 degrees, the steep side wall angle is 65 degrees, and the height is 6.2mm. The directional steering section is provided with a tapered throat section, the inlet and outlet widths of the tapered throat section are 9.2mm, the middle throat width is 6.0mm, and the tapering length from the inlet to the outlet is 5.0mm. The directional steering section is provided with an offset guide rib at the exit position of the tapering throat section. The offset guide rib has a height of 1.5 mm, a top width of 8.2 mm, and a length of 1.5 mm. A tip-capturing groove is provided near the offset guide rib of the directional steering section. The tip-capturing groove is located on the side away from the tapered throat section and on the steep side of the directional steering section. The groove width is 3.2 mm, the groove depth is 1.3 mm, and the groove length is 1.5 mm. The spiral directional track has a unidirectional micro-spine group on the surface of the locking and holding section. The unidirectional micro-spine group is arranged in a forward inclined direction along the seed's forward direction so that the equivalent frictional resistance of the seed in the forward direction is less than the equivalent frictional resistance in the backward direction. The unidirectional micro-spine group is a periodic oblique rib array. The rib height is 0.3~0.8mm, the pitch is 1.5~3.0mm, the radius of the rib tip radius is 0.2~0.5mm, and the angle between the oblique rib and the center line of the spiral directional track is 10°~30°.

[0015] As a preferred embodiment of the present invention, the equivalent normal clamping force N1 of the spring-guided wheel on a single seed satisfies: N1 = N0 + k·δ1, 0 ≤ δ1 ≤ δ max ; Where N0 is the preload, k is the equivalent stiffness, δ1 is the indentation, and δ max This is the maximum push-in limit; The spiral directional track, under the pressure of the spring directional wheel and the action of the offset guide rib, satisfies the forward-pointing steering criterion M: M=μ·tanβ·r e ≥M r ; Where μ is the equivalent friction coefficient, r e M is the equivalent force arm from the point of application of the lateral force to the center of mass of the seed. r β is the anti-overturning resistance torque when the tapered throat segment is locked, and β is the inclination angle of the tapered throat segment's contact slope.

[0016] As a preferred embodiment of the present invention, the directional conveying device includes an inner shell, an outer shell, a directional brush belt, a directional brush belt drive wheel, and a directional brush belt driven wheel. The outer shell is provided with a seed conveying track, which consists of a vertical wall and a sloping bottom surface connecting to the bottom of the vertical wall. The sloping bottom surface is made of polished metal, and the vertical wall surface is made of rubber-coated surface, to form low-friction sliding at the bottom surface and friction-limited positioning at the side wall, maintaining boundary conditions. The directional brush belt is fitted onto the drive wheel and the driven wheel, and the directional brush belt has a double-layer brush structure. The drive wheel and the driven wheel drive the directional brush belt to rotate within the inner and outer shells and convey seeds along the seed conveying track. The double-layer brush structure includes alternating short-bristle brush layers and long-bristle brush layers. The short-bristle brush layers provide tangential conveying driving force to the seeds, while the long-bristle brush layers contact the bottom surface of the seed conveying track to form flexible support and, together with the side wall of the outer shell, form a positioning limit to suppress secondary turning during the conveying process.

[0017] Preferably, in this invention, the bristle height of the short-bristle brush layer is less than that of the long-bristle brush layer, and each bristle of the long-bristle brush layer has a composite bristle structure, including an elastic bristle body and a hard end set at the tip of the bristle, wherein the elastic modulus E of the hard end is... t The elastic modulus E of the elastic bristle body is greater than that of the elastic bristle body. s ,satisfy: E t ≥2E s ; The elastic modulus E of the hard end t At 5~7 GPa, the elastic modulus E of short-bristled brushes z At 3.5~5 GPa; This allows the tips of the long-bristled brush layer to form high local bending stiffness when in contact with the seed, thus inhibiting seed deflection, while the elastic bristle body remains supple to reduce compression damage.

[0018] The rigid end is made of polyamide, and the elastic bristle body is made of polyurethane elastomer. The short-bristle brush layer is made of polyurethane elastomer, so that the equivalent coefficient of friction between the short-bristle brush layer and the seed is μ. s The equivalent coefficient of friction between the long-bristled brush layer and the seed transport track is μ. l And satisfy: μ s >μ l ; This achieves a division of labor where the short-bristle brush layer drives the conveying, while the long-bristle brush layer and the sidewall of the seed conveying track work together to suppress secondary deflection.

[0019] As a preferred embodiment of the present invention, the seed guide groove is provided with a conveying track, and its end is connected to a steering track. The steering track is a wedge-shaped limiting channel, which is used to lock the seed's long axis and embryo side before it enters the furrow, so that the seed enters the furrow with its tip facing down and its embryo side against the furrow wall.

[0020] As a preferred embodiment of the present invention, the transmission mechanism includes a motor and a gear reducer. The gear reducer is connected to the seed brush wheel, the seed orientation composite wheel, and the orientation brush belt drive wheel to achieve rhythm matching of wheel rotation orientation and orientation conveying. The gear reducer includes a motor shaft gear, a primary double-drive gear, a seed brush wheel gear, a secondary double-drive gear, an orientation brush belt drive wheel gear, an orientation brush belt drive wheel transmission gear, and a seed orientation composite wheel gear. The primary and secondary double-drive gears enable the branch output and speed ratio setting of the seed brush wheel, the orientation brush belt drive wheel, and the seed orientation composite wheel.

[0021] The beneficial effects of this invention are as follows: The two-stage gap adjustment of the initial orientation device within the seed metering tray improves the stability of single-grain adsorption and reduces random posture input; the throat discrimination of the spiral orientation track, the torque triggering of the offset guide rib, and the locking of the tip-capturing groove achieve deterministic orientation with the tip pointing forward; the adjustable preload and stroke limit of the spring orientation wheel achieve a low-damage, low-blockage normal load window, and the equal-diameter following of the paddle tip suppresses slippage failure; the "intermittent brush + rubber protrusion" of the brush fixing wheel achieves anti-rebound anchoring and posture maintenance, and the superimposed anisotropic friction of low forward resistance and high backward resistance, mimicking earthworm unidirectional micro-spines, suppresses secondary reversal; the "low-friction liner on the bottom surface + wear-resistant rubber limit on the side wall + double-layer orientation brush belt with division of labor" achieves stable conveying after orientation; finally, the wedge-shaped steering track achieves final orientation with the tip pointing downward and the embryo surface attached to the furrow wall, thus significantly improving the consistency of furrow orientation and sowing quality under high-speed dense planting conditions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a biomimetic spiral directional seeding device according to the present invention; Figure 2 This is an exploded view of the overall structure of a biomimetic spiral directional seeding device according to the present invention; Figure 3 This is a schematic diagram of the orientation device structure of a biomimetic spiral directional seeding device according to the present invention; Figure 4 This is a schematic diagram of the structure of a biomimetic spiral directional seeding device air suction seed metering device in this invention; Figure 5 This is a schematic diagram of the orientation process of a biomimetic spiral directional seeding device according to the present invention; Figure 6This is a schematic diagram of the spiral directional track structure of a biomimetic spiral directional seeding device according to the present invention; Figure 7 This is a front view of the spiral directional track structure of a biomimetic spiral directional seeding device according to the present invention; Figure 8 yes Figure 7 AA section view; Figure 9 This is a partial structural diagram of the outer shell of a biomimetic spiral directional seeding device according to the present invention; Figure 10 This is a schematic diagram of the seed-directing composite wheel structure of a biomimetic spiral directional seed-dispensing device according to the present invention; Figure 11 This is a schematic diagram of the seed brush wheel structure of a biomimetic spiral directional seed dispensing device according to the present invention; Figure 12 This is a schematic diagram of the spring-oriented wheel structure of a biomimetic spiral directional seeding device according to the present invention; Figure 13 This is a front view of the spring-oriented wheel structure of a biomimetic spiral directional seeding device according to the present invention; Figure 14 This is a schematic diagram of the preliminary orientation device structure of a biomimetic spiral directional seeding device in this invention; Figure 15 This is a schematic diagram of the seed guide groove structure of a biomimetic spiral directional seeding device according to the present invention; Figure 16 This is a schematic diagram of the gradual transition section of the seed guide groove in a biomimetic spiral directional seeding device of the present invention; Figure 17 This is a schematic diagram of the seed guide groove limiting section structure of a biomimetic spiral directional seeding device according to the present invention; Figure 18 This is a schematic diagram of the seed-accepting track structure of a biomimetic spiral directional seed-dispensing device according to the present invention; Figure 19 This is a schematic diagram of the connecting slope structure of a biomimetic spiral directional seeding device in this invention; Figure 20 This is a schematic diagram of the directional brush belt structure of a biomimetic spiral directional seeding device according to the present invention; Figure 21 yes Figure 20 A magnified view of part B; Figure 22 This is a schematic diagram of the gearbox structure of a biomimetic spiral directional seeding device in this invention.

[0023] 1. Air suction seed metering device; 2. Transmission mechanism; 3. Spiral orientation device; 4. Oriented conveying device; 5. Seed guide groove; 11. Seed metering tray; 12. Seed cleaning device; 13. Preliminary orientation device; 14. Seed chamber shell; 131. Concave reversing plate; 132. Positioning plate; 21. Motor; 22. Gear housing; 23. Gearbox cover; 31. Seed tray; 32. Seed-oriented composite wheel; 33. Connecting slope; 34. Seed brush wheel; 35. Spiral directional shell; 321. Outer fixing plate; 322. Brush fixing wheel; 323. Spring directional wheel; 324. Inner fixing plate; 341. Outer end cap; 342. Seed brush wheel body; 343. Inner end cap; 3231. Paddle; 3232. Spring; 3233. Paddle tip; 3234. Spring support; 41. Outer shell; 42. Driven brush wheel; 43. Drive brush wheel; 44. Oriented brush belt; 45. Inner shell; 441. Long-bristle brush layer; 442. Short-bristle brush layer; 51. Conveying track; 52. Turning track; 521. Gradual transition section; 522. Limiting section; S1, Inlet stabilization section; S2, Directional steering section; S3, Locking and holding section; S21, Tapered throat section; S22, Offset guide rib; S23, Tip capture groove; S31, Unidirectional microspine group; R1, fillet radius at the bottom of the groove; α1, gentle sidewall angle; α2, steep sidewall angle; a. Helical directional track; b. Directional conveying track; I. Motor shaft gear; II. First-stage double-drive gear; III. Second-stage double-drive gear; IV. Brush seed wheel shaft gear; V. Brush drive wheel shaft gear; VI. Third-stage drive gear; VII. Seed orientation composite wheel shaft gear; Detailed Implementation

[0024] To make the technical solution, structural features and beneficial effects of the present invention clearer, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] like Figures 1-3As shown, a biomimetic spiral directional seeding device of the present invention includes an air suction seed metering device 1, a transmission mechanism 2, a seed spiral directional device 3, a directional conveying device 4, and a seed guide groove 5. The air suction seed metering device 1 includes a negative pressure chamber shell and a seed chamber shell 14 arranged on the left and right sides. The seed chamber shell 14 is equipped with a seed metering disc 11, a seed cleaning device 12, a preliminary directional device 13, and other structures. The transmission mechanism 2 includes a motor 21, a gear shell 22, and a gearbox cover 23. The seed spiral directional device 3 includes a seed receiving track 31, a seed directional composite wheel 32, a connecting slope 33, a seed brush wheel 34, and a spiral directional shell 35. The directional conveying device 4 includes an outer shell 41, a brush driven wheel 42, a brush driving wheel 43, a directional brush belt 44, and an inner shell 45. The seed guide groove 5 includes a conveying track 51 and a steering track 52.

[0026] like Figure 2 , Figure 4 and Figure 5 As shown, the seed metering disc 11 is rotatably connected to the seed chamber housing 14 of the air suction seed meterer 1. The seed metering disc 11 has multiple air suction holes arranged around its circumference. The two limiting plates of the seed cleaning device 12 are fixed inside the seed chamber housing 14 and located at the trajectory position of the air suction holes. They are used to remove multiple adsorbed particles at the air suction holes and reduce reseeding. The seed chamber housing 14 can be matched and fixedly connected with the seed spiral orientation device below.

[0027] like Figure 2 , Figure 5 , Figure 14 As shown, the preliminary orientation device 13 is installed below the seed cleaning device 12. The preliminary orientation device 13 consists of a concave reversing plate 131 fixed to the limiting plate and a positioning plate 132 fixed to the concave reversing plate 131. The concave reversing plate 131 has a concave arc-shaped tidying surface extending radially along the air suction hole of the seed metering disc 11. The cross-section of the concave reversing plate 131 is S-shaped. The positioning plate 132 has a limiting surface extending tangentially along the air suction hole of the seed metering disc 11. The positioning plate 132 and the concave reversing plate 131 are arranged sequentially in the rotation direction of the seed metering disc 11 and form a continuous tidying channel. The preliminary orientation device 13 achieves "strong sorting - weak holding" attitude control through a continuous sorting channel, which has two levels of gaps: the concave reversing plate 131 and the surface of the seed metering disc 11 form the first sorting gap g in the seed carrying area. s The positioning plate 132 and the surface of the seed metering disc 11 form a second sorting gap g. o , and g o >g s As the seed metering disc 11 rotates, carrying seeds through the concave reversing plate 131, the first sorting gap g... sIt provides strong geometric constraints and frictional disturbances, causing the seeds in the edge-adhesive or point-adhesive state to undergo controlled rolling, gradually transforming into surface-adhesive adhesion, thereby improving the coverage of the suction holes and the adhesion stability; subsequently, the seeds enter the action area of ​​the positioning plate 132, and the second sorting gap g o While ensuring passability, it restricts lateral movement and secondary flipping, thus achieving stable maintenance of the adhesive posture.

[0028] In this embodiment, the two-stage gap satisfies: g s =(0.65~0.90) T, g o =(0.80~1.05) T, g o >g s ; Where T represents the characteristic thickness of the corn seed, in mm.

[0029] To ensure sufficient initial alignment and reversing time under high-speed operating conditions, the radius R of the concave arc alignment surface of the concave reversing plate 131 is [not specified]. s Preferred satisfaction: R s =(1.0~3.0) R p ; Where R p The radius of the suction hole trajectory on the seed metering disc is in mm.

[0030] The concave reversing plate 131 covers the circumferential rotation angle of the seed metering disc 11 by 10°~25° along the circumference of the seed metering disc 11 to ensure sufficient posture adjustment time under high-speed conditions, thus ensuring good adjustment effect and passability.

[0031] like Figures 1-5 , Figures 6-13 , Figures 18-19As shown, the seed spiral orientation device 3 is fixedly connected to the lower side of the seed unloading area of ​​the air suction seed metering device 1. It can be fixedly connected to the seed chamber shell. It includes a seed receiving track 31, a seed orientation composite wheel 32, a connecting slope 33, a seed brushing wheel 34, a spiral orientation shell 35, and a spiral orientation track a. The spiral orientation shell 35 is fixedly connected to the seed chamber shell 14. The spiral orientation track a is opened on the inner arc surface of the spiral orientation shell 35 and extends along the circumference of the spiral orientation shell 35. The seed receiving track 31 is located at the entrance of the spiral orientation shell 35 and is tangentially arranged with the seed brushing wheel 34 and the seed orientation composite wheel 32. It is used to receive single seeds unloaded by the air suction seed metering device 1. The seed receiving track 31, in conjunction with the seed brushing wheel 34 and the seed orientation composite wheel 32, allows the seeds to gradually transition from free fall to a constrained sliding state, which is beneficial for the seeds to enter the spiral orientation shell 35 and reduces bouncing and random tumbling. The connecting slope 33 is set between the brush fixing wheel 322 and the directional brush belt 44 to smoothly connect the seed output process of the spiral directional shell 35 to the directional conveying device 4 below, while buffering the seed posture disturbance.

[0032] like Figure 10 As shown, the seed orientation composite wheel 32 consists of an outer fixed plate 321, a brush fixing wheel 322, a spring orientation wheel 323, and an inner fixed plate 324. The outer fixed plate 321 and the inner fixed plate 324 are connected by a tie rod end plate and screws, which coaxially locks the brush fixing wheel 322 and the spring orientation wheel 323 and makes them rotate synchronously to form an integrated composite wheel. The brush fixing wheel 322 adopts a combination structure of intermittent annular brushes and rubber protrusions, which are arranged alternately: the brushes provide continuous flexible support and damping, and the rubber protrusions provide discrete point constraints and anti-rebound anchoring. Together, they improve the attitude retention capability after orientation and reduce the probability of rebound and reversal under high-speed conditions.

[0033] like Figures 12-13 As shown, the spring-guided wheel 323 includes a paddle 3231, a spring 3232, a paddle tip finger 3233, and a spring support 3234. The paddle 3231 provides radially compliant clamping under the action of the spring 3232, forming a variable normal load. The annular spring support 3234 is used for installation positioning and force transmission. The paddle tip finger 3233 is evenly distributed along the circumference, and its outer diameter is consistent with the inner diameter of the helical guide housing 35, ensuring that the paddle tip finger 3233 forms a constant diameter following and stable fit against the inner wall of the helical guide housing 35 during operation. When there is a tendency for slippage between the seed and the wheel body, the paddle tip finger 3233 can provide a continuous tangential bearing surface and reliable geometric guidance, suppressing the failure of clamping without force transmission. The paddle tip finger 3233 is also used to limit the maximum pressing stroke, preventing over-pressure from causing seed damage or channel jamming.

[0034] The elastic clamping element composed of the paddle 3231 and the spring 3232 is used to adjust the pre-tightening amount, so that the spring directional wheel 323 can establish sufficient normal clamping force under different seed sizes, coating thicknesses and friction conditions. The equivalent normal clamping force N1 of the spring-guided wheel 323 on a single seed preferably satisfies the following: N1 = N0 + k·δ1, 0 ≤ δ1 ≤ δ max ; Where N0 is the preload (N), k is the equivalent stiffness (N / mm), and δ is the indentation (mm). max The maximum indentation limit is set in mm; and preferably δ1 = 2.0 mm, δ max =3.5mm, and the equivalent normal force working window is 1.5~3.0N.

[0035] like Figure 11 As shown, the seed brushing wheel 34 is composed of an outer end cover 341, a seed brushing wheel body 342 and an inner end cover 343 fixedly connected, and is located at the entrance of the spiral directional housing 35. It forms a clamping and feeding cooperation with the seed directional composite wheel 32: the seed brushing wheel 34 applies tangential disturbance to the seeds, which is beneficial to improve the seed entry into the seed receiving track 31 and being captured by the seed directional composite wheel 32 for directional process.

[0036] like Figures 6-8 As shown, the helical directional track a is divided into an inlet stabilization section S1, a directional turning section S2, and a locking and holding section S3. Preferably, the lengths of the three sections satisfy the following conditions: L S1 =18, L S2 =35, L S3 =18; The basic cross-section of the spiral directional track a is an asymmetric U / V composite groove, with a groove bottom radius R1=4.2mm, a gentle side wall angle α1=35 degrees, a steep side wall angle α2=65 degrees, and a net height H=6.2mm; The groove width of the inlet stabilizing section S1 of the spiral directional track a is W1=9.2mm, and the groove width of the locking and holding section S3 is W2=8.8mm. This process is used to form a stable contact side under the pressing action of the spring directional wheel 323, so that the rolling path of the seed in the channel is controllable and the orientation process is repeatable.

[0037] Furthermore, the directional steering section is equipped with a tapered throat section S21, with a throat inlet width of W. t1 =9.2mm, width of the middle throat W t2 =6.0mm, tapering length L t =5.0mm; the directional steering section S2 is equipped with an offset guide rib S22, the height of which is H. r =1.5mm, top width W r =8.2mm, the effective length of the offset guide rib is L r=1.5mm. A tip-catching groove S23 is provided on the steep side of the groove bottom in the directional steering section S2, with a groove width W. p =3.2mm, groove depth H p =1.3mm, groove length L p =1.5mm.

[0038] In this embodiment, the orientation mechanism of the seed achieving "tip facing forward" within the helical orientation housing 35 is as follows: After entering the stabilizing section S1, the seed is stably pressed against one side of the helical orientation track a by the normal pressure of the spring orientation wheel 323, and slides forward along the helical orientation track a under the tangential friction drive of the spring orientation wheel 323; when the seed enters the orientation turning section S2, if the seed tip faces forward, the seed tip preferentially passes through the tapered throat section S21 and enters the biased guide rib S22, and is then captured by the tip capturing groove S23, achieving geometric locking; if the seed tip faces backward, the blunt end forms a locking point at the throat, the spring orientation wheel 323 continuously provides tangential drive, the biased guide rib S22 converts the tangential drive into a lateral component force and forms a flipping torque, causing the seed to roll under forced rotation and guide the tip into the capturing groove S23 to complete the turning, ultimately with the tip facing forward. The criterion for determining whether the turning has been completed after passing through the orientation turning section S2 is: M=μ∙tanβ∙r e ≥M r ; Where μ is the equivalent friction coefficient, r e M is the equivalent force arm (mm) from the point of application of the lateral force to the center of mass of the seed. r β is the anti-rollover resistance torque (N·mm) when the throat is locked, and β is the inclination angle of the tapered throat section. After entering the locking and holding section S3, the continuous flexible support of the brush fixing wheel 322 and the point constraint of the rubber protrusion work together to suppress secondary rollover and rebound reversal, thus maintaining the tip-forward posture.

[0039] Furthermore, to better improve seed stability and resilience, a unidirectional micro-spine group S31, mimicking the shape of an earthworm, is arranged on the surface of the locking and holding section S3. The unidirectional micro-spine group S31 is arranged at an angle along the seed's forward direction, ensuring that the frictional resistance in the forward direction is less than that in the backward direction. The unidirectional micro-spine group S31 is a periodic array of oblique ribs, with a rib height H. a =0.3~0.8mm, pitch P a =1.5~3.0mm, the radius of the spine tip radius R4 = 0.2~0.5mm, and the angle between the inclined direction of the oblique rib and the center line of the helical directional track a is 10°~30°. Under the Coulomb friction model, the equivalent friction coefficients of the unidirectional micro-spine group S31 in the forward and reverse directions are... and satisfy: ; ; ; ; in The Coulomb friction coefficient of the substrate surface without microthorns. The micro-thorn angle is designed to achieve anisotropic friction characteristics of low drag in the forward direction and high drag in the reverse direction; and the unidirectional micro-thorns cover 40% to 80% of the directional steering segment length. Preferably... =0.3, micro-thorn slope angle Friction amplification ratio This creates a locked track that is smooth to move forward but difficult to roll or reverse.

[0040] like Figures 1-3 , Figure 9 , Figure 20 , Figure 21 As shown, the directional conveying device 4 includes an outer shell 41, a brush driven wheel 42, a brush drive wheel 43, a directional brush belt 44, and an inner shell 45. The outer shell 41 and the inner shell 45 cooperate to form a closed conveying cavity. A seed conveying track b is provided inside the outer shell. The seed conveying track b consists of a vertical wall and a sloping bottom surface connecting to the bottom of the vertical wall. The sloping bottom surface is made of polished metal to reduce friction and facilitate seed sliding. The cross-section of the vertical wall is arc-shaped, and the vertical wall surface is coated with a wear-resistant rubber as the friction material, forming a low-friction sliding bottom surface and a friction-limiting side wall boundary condition to maintain the posture of the seed during its forward movement, ensuring stable contact and posture constraint. The directional brush belt 44 is mounted on the brush drive wheel 43 and the brush driven wheel 42, and adopts a double-layer brush structure. The double-layer brush structure includes alternating long-bristle brush layer 441 and short-bristle brush layer 442. The short-bristle brush layer 442 is used to provide tangential pushing and sealing of the seeds. The long-bristle brush layer 441 contacts the bottom surface of the seed conveying track b to form elastic support, and together with the vertical wall surface, forms an attitude limiting boundary, thereby suppressing secondary turning during the conveying process.

[0041] like Figures 20-21 As shown, the individual bristles of the long-bristle brush layer 441 have a composite bristle structure, comprising an elastic bristle body and a hard tip at the bristle tip. The elastic modulus E of the hard tip is... t Greater than the elastic modulus E of the elastic bristle body s and satisfy E t ≥2E s In a preferred embodiment, the elastic modulus E of the rigid end is... t =5~7GPa, elastic modulus E of short-bristled brush z=3.5~5GPa, the rigid end material is made of polyamide, and the bristle body material is made of polyurethane elastomer; through the division of labor of short bristle drive and long bristle support and limit, the posture stability is improved and the extrusion damage is reduced while ensuring the conveying efficiency.

[0042] like Figures 15-17 As shown, the seed guide groove 5 is installed at the outlet end of the directional conveying device 4, and includes a conveying track 51 and a turning track 52. The turning track 52 is a wedge-shaped limiting channel, and includes a gradual transition section 521 and a limiting section 522: the gradual transition section is used to eliminate residual attitude disturbance when entering the seed guide groove 5; the limiting section is used to lock the seed's long axis and embryo side before entering the groove, so that the seed finally enters the bottom of the groove with its tip facing down and its embryo side against the groove wall.

[0043] like Figure 2 and Figure 22 As shown, the transmission mechanism 2 includes a motor 21 and a gear reducer. The gear reducer includes a gear housing 22, a gearbox cover 23, a motor shaft gear I, a first-stage double-drive gear II, a second-stage double-drive gear III, a seed-brush wheel shaft gear IV, a brush drive wheel shaft gear V, a third-stage transmission gear VI, and a seed-oriented composite wheel shaft gear VII. The motor shaft gear I drives the first-stage double-drive gear II and the second-stage double-drive gear III, which in turn drive the seed-brush wheel shaft gear IV, the brush drive wheel shaft gear V, the third-stage transmission gear VI, and the seed-oriented composite wheel shaft gear VII, respectively, to achieve rhythm matching between the seed-brush wheel 34, the seed-oriented composite wheel 32, and the brush drive wheel 43.

[0044] In a preferred embodiment, the seed-oriented composite wheel 32 has an equivalent contact diameter of 80 mm, the seed-brushing wheel 34 has a diameter of 32 mm, and the brush drive wheel 43 has a diameter of 25 mm. The gear transmission ratio is set so that the linear velocity of the seed-brushing wheel is slightly higher than that of the composite wheel to prevent accumulation. The linear velocity of the directional brush belt 44 matches the discharge speed of the spiral directional track a with a slight margin to ensure continuous material reception, thereby avoiding posture disturbances caused by accumulation or bouncing. The overall working speed should match the normal professional speed of the seeder to meet the corresponding sowing rhythm.

[0045] Further optimization involves setting the linear velocity of the seed-oriented composite wheel 32 to be 1.05 to 1.30 times the average linear velocity of the seed within the spiral-oriented shell 35, in order to improve directional convergence efficiency and reduce the risk of jamming.

[0046] In summary, this implementation reduces random attitude input by adjusting the two-stage gap at the seeding tray end, achieves deterministic convergence with the tip pointing forward through the "throat discrimination + offset guide rib torque trigger + tip capture groove locking" of the spiral directional track, suppresses rebound and reversal through the point constraint and flexible damping of the brush fixing wheel and the anisotropic friction characteristics of the unidirectional micro-thorns in the locking section, and achieves attitude-maintaining conveying by "low friction sliding on the bottom surface + friction limiting on the side wall + division of labor of the double-layer directional brush belt" in the directional conveying section, and finally achieves final orientation of entering the furrow with the tip pointing downward and the embryo surface attached to the furrow wall in the wedge-shaped turning track, thereby meeting the directional sowing requirements under high-speed dense planting conditions.

Claims

1. A biomimetic spiral directional seed dispensing device, comprising an air-suction seed metering device, the air-suction seed metering device comprising a negative pressure chamber shell and a seed chamber shell, the negative pressure chamber shell being connected to an air circuit system, a seed metering disc being rotatably connected inside the seed chamber shell, and the seed metering disc having a plurality of air-suction type holes arranged along its circumference and communicating with the negative pressure chamber shell as a seed carrying area, characterized in that, It also includes a preliminary orientation device, a seed spiral orientation device, an orientation conveying device, a seed guide groove, and a transmission mechanism; The preliminary orientation device is fixed inside the seed chamber shell and corresponds to the rotation trajectory of the air suction hole on the seed metering tray. The preliminary orientation device is used to control the rolling of the seeds on the seed metering tray, so that the seeds in the edge adsorption or spot adsorption state are controlled to roll, gradually transforming them into surface adsorption and maintaining the surface adsorption state into the seed spiral orientation device. The seed spiral orientation device is fixed to the seed chamber shell and connected to the seed unloading area outlet of the seed chamber shell. The seed spiral orientation device is used to control the seeds to gradually transition from free fall to a constrained sliding state, and to complete the attitude adjustment with the tip facing forward and to transport them stably. The directional conveying device is fixed to the seed chamber shell and connected to the outlet end of the seed spiral directional device. The directional conveying device is used to convey seeds with a uniform posture to the seed guide groove. The seed guide groove is installed at the outlet end of the directional conveying device. The seed guide groove is used to lock the final discharged seed into the bottom of the groove with the tip facing down. The transmission mechanism is installed on the seed chamber shell and is used to connect with the seed spiral orientation device and the orientation conveying device to achieve the rhythm matching of the spiral orientation and the orientation conveying. The preliminary orientation device includes: a concave reversing plate fixedly connected to the seed chamber shell, and a positioning plate fixedly connected to the bottom of the concave reversing plate. The concave reversing plate has a concave arc-shaped finishing surface extending radially along the air suction hole of the seed metering disc. The concave arc-shaped finishing surface and the surface of the seed metering disc form a first finishing gap g in the seed carrying area. s The positioning plate has a limiting surface extending tangentially along the air suction hole of the seed metering disc, and the limiting surface forms a second sorting gap g with the surface of the seed metering disc. o Furthermore, the concave reversing plate and the positioning plate are arranged sequentially along the rotation direction of the seed metering disc to form a continuous sorting channel, so that the seeds in the edge-adsorbed or point-adsorbed state are controlled to roll into surface-adsorbed state at the air suction hole and the secondary flipping is suppressed. First sorting gap g s With the second cleaning gap g o satisfy: g s =(0.65~0.90) T,g o =(0.80~1.05) T,g o >g s ; Where T represents the characteristic thickness of the corn seed, in mm; The radius of the concave arc finishing surface is 1.0 to 3.0 times the radius of the air suction hole, and the working area of ​​the concave reversing plate along the circumference of the seed metering disc covers 10° to 25° of the rotation angle of the seed metering disc. The radius R of the concave arc finishing surface s satisfy: R s =(1.0~3.0) R p ; Where R p The radius of the air suction hole in the seed metering disc is in mm.

2. The biomimetic spiral directional seeding device according to claim 1, characterized in that, The seed spiral orientation device includes a spiral orientation shell, a spiral orientation track, a seed brush wheel, a seed orientation composite wheel, a seed receiving track, and a connecting slope. The spiral orientation shell is fixed to the seed chamber shell. The spiral orientation track is formed on the inner arc surface of the spiral orientation shell and extends along the circumference of the spiral orientation shell. The seed orientation composite wheel and the seed brush wheel are rotatably connected inside the spiral orientation shell and arranged tangentially to the spiral orientation track. The seed orientation composite wheel is formed by a spring orientation wheel and a brush fixing wheel coaxially fixedly connected by an inner fixing plate and an outer fixing plate to form an integral structure, so as to simultaneously provide compression and stable tangential friction drive for the seeds in the spiral orientation track, so that the seeds can complete the orientation adjustment with the tip facing forward and be stably transported in the spiral orientation track. The seed receiving track is located at the entrance of the spiral orientation track and is arranged tangentially to the seed brush wheel and the seed orientation composite wheel. The connecting slope is located between the exit of the spiral orientation track and the entrance of the orientation conveying device, so as to smoothly connect the seed exit process of the spiral orientation track to the orientation conveying device below, and at the same time buffer the seed orientation disturbance.

3. The biomimetic spiral directional seeding device according to claim 2, characterized in that, The brush fixing wheel includes intermittent annular brushes and rubber protrusions embedded in the middle of the brushes. The brushes and rubber protrusions are arranged alternately. The brushes are used to provide continuous flexible support and damping, and the rubber protrusions are used to provide stable support. The inner and outer fixed plates are connected by a tie rod end plate and screws, so that the spring directional wheel and the brush fixed wheel are coaxially locked and rotate synchronously. The spring-guided wheel includes a wheel body and an elastic clamping element disposed on the wheel body. The wheel body is composed of a paddle tip and a spring support. Multiple spring connecting holes are evenly distributed on the circumferential surface of the annular spring support. The paddle tip is fixed to the circumferential surface of the spring support and is arranged alternately with the spring connecting holes. The outer diameter of the annular ring formed by the multiple paddle tips is consistent with the inner diameter of the spiral directional track, so that the paddle tip forms a uniform diameter following and stable fit against the inner wall of the channel in the working state. The elastic clamping element is used to adjust the pre-tightening pressure, so that the spring directional wheel can establish sufficient normal clamping force under different seed sizes, coating thicknesses and friction conditions, ensuring effective frictional contact between the seed and the spiral directional track wall. The elastic clamping element consists of multiple ring-shaped paddles and springs. The lower end of the spring is fixed to the spring connection hole of the spring support and is arranged alternately with the paddle tops. The paddles are fixed to the upper end of the springs, and the paddles support the seeds in the spiral directional track under the support of the springs. The seed brushing wheel is located at the entrance of the spiral directional track. The seed brushing wheel and the seed directional composite wheel form a clamping and feeding cooperation to apply tangential disturbance to the seeds in the stable section of the entrance and reduce accumulation and jamming. The seed brushing wheel includes: a seed brushing wheel body, and an outer end cover and an inner end cover located on both sides of the seed brushing wheel body and fixedly connected to the seed brushing wheel body on the same axis to form an integral structure.

4. The biomimetic spiral directional seeding device according to claim 2, characterized in that, The spiral directional track is divided into an inlet stabilization section, a directional turning section, and a locking and holding section; the slot width of the inlet stabilization section is 9.2 mm, and the slot width of the locking and holding section is 8.8 mm. The cross-section of the spiral directional track is groove-shaped. Under the pressure of the spring directional wheel, the groove-shaped spiral directional track forms a stable contact side. The bottom radius of the spiral directional track is 4.2mm, the gentle side wall angle is 35 degrees, the steep side wall angle is 65 degrees, and the height is 6.2mm. The directional steering section is provided with a tapered throat section, the inlet and outlet widths of the tapered throat section are 9.2mm, the middle throat width is 6.0mm, and the tapering length from the inlet to the outlet is 5.0mm. The directional steering section is provided with an offset guide rib at the exit position of the tapering throat section. The offset guide rib has a height of 1.5 mm, a top width of 8.2 mm, and a length of 1.5 mm. A tip-catching groove is provided near the offset guide rib of the directional steering section. The tip-catching groove is located on the steep side of the directional steering section. The groove width is 3.2 mm, the groove depth is 1.3 mm, and the groove length is 1.5 mm. The spiral directional track has a unidirectional micro-spine group on the surface of the locking and holding section. The unidirectional micro-spine group is arranged in a forward inclined direction along the seed's forward direction so that the equivalent frictional resistance of the seed in the forward direction is less than the equivalent frictional resistance in the backward direction. The unidirectional micro-spine group is a periodic oblique rib array. The rib height is 0.3~0.8mm, the pitch is 1.5~3.0mm, the radius of the rib tip radius is 0.2~0.5mm, and the angle between the oblique rib and the center line of the spiral directional track is 10°~30°.

5. A biomimetic spiral directional seeding device according to claim 2, characterized in that, The equivalent normal compressive force N1 of the spring-guided wheel on a single seed satisfies: N1=N0+k∙δ1,0≤δ1≤δ max ; Where N0 is the preload, k is the equivalent stiffness, δ1 is the indentation, and δ max This is the maximum push-in limit; The spiral directional track, under the pressure of the spring directional wheel and the action of the offset guide rib, satisfies the forward-pointing steering criterion M: M = μ∙tanβ∙re ≥ Mr; Where μ is the equivalent friction coefficient, r e M is the equivalent force arm from the point of application of the lateral force to the center of mass of the seed. r β is the anti-overturning resistance torque when the tapered throat segment is locked, and β is the inclination angle of the tapered throat segment's contact slope.

6. The biomimetic spiral directional seeding device according to claim 1, characterized in that, The directional conveying device includes an inner shell, an outer shell, a directional brush belt, a directional brush belt drive wheel, and a directional brush belt driven wheel. The outer shell is equipped with a seed conveying track, which consists of a vertical wall and a sloping bottom surface connecting to the bottom of the vertical wall. The sloping bottom surface is made of polished metal, and the vertical wall surface is made of rubber-coated material to create low-friction sliding at the bottom and friction-limited positioning at the side walls, maintaining boundary conditions. The directional brush belt is fitted onto the drive wheel and the driven wheel, and the directional brush belt has a double-layer brush structure. The drive wheel and the driven wheel drive the directional brush belt to rotate within the inner and outer shells, conveying seeds along the seed conveying track. The double-layer brush structure includes alternating short-bristle brush layers and long-bristle brush layers. The short-bristle brush layers provide tangential conveying driving force for the seeds, while the long-bristle brush layers contact the bottom surface of the seed conveying track to form flexible support and, together with the side walls of the outer shell, form posture limiting to suppress secondary turning during the conveying process.

7. A biomimetic spiral directional seeding device according to claim 6, characterized in that, The bristle height of the short-bristle brush layer is less than that of the long-bristle brush layer. Each bristle in the long-bristle brush layer has a composite bristle structure, including an elastic bristle body and a hard end set at the tip of the bristle. The elastic modulus E of the hard end is... t The elastic modulus E of the elastic bristle body is greater than that of the elastic bristle body. s ,satisfy: AND t ≥2E s ; The elastic modulus E of the hard end t At 5~7 GPa, the elastic modulus E of short-bristled brushes z At 3.5~5 GPa; This allows the tips of the long-bristled brush layer to form localized bending stiffness when in contact with the seed to inhibit seed deflection, while the elastic bristle body remains supple to reduce compression damage. The rigid end is made of polyamide, and the elastic bristle body is made of polyurethane elastomer. The short-bristle brush layer is made of polyurethane elastomer, so that the equivalent coefficient of friction between the short-bristle brush layer and the seed is μ. s The equivalent coefficient of friction between the long-bristled brush layer and the seed transport track is μ. l And satisfy: m s >m l ; This achieves a division of labor where the short-bristle brush layer drives the conveying, while the long-bristle brush layer and the sidewall of the seed conveying track work together to suppress secondary deflection.

8. A biomimetic spiral directional seeding device according to claim 1, characterized in that, The seed guide groove is equipped with a conveying track, and its end is connected to a steering track. The steering track is a wedge-shaped limiting channel, which is used to lock the seed's long axis and embryo side before it enters the furrow, so that the seed enters the furrow with its tip facing down and its embryo side against the furrow wall.

9. A biomimetic spiral directional seeding device according to claim 1, characterized in that, The transmission mechanism includes a motor and a gear reducer. The gear reducer is connected to the seed brush wheel, the seed-oriented composite wheel, and the oriented brush belt drive wheel. The gear reducer includes a motor shaft gear, a primary double-drive gear, a seed brush wheel gear, a secondary double-drive gear, a oriented brush belt drive wheel gear, a oriented brush belt drive wheel transmission gear, and a seed-oriented composite wheel gear. The primary and secondary double-drive gears enable the branched output and speed ratio setting of the seed brush wheel, the oriented brush belt drive wheel, and the seed-oriented composite wheel.

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