A centrifugal seed meter with constant seed filling amount and uniform seeding

Abstract

The invention relates to the technical field of agricultural sowing machinery, and discloses a centrifugal seeding device with constant seed filling amount and uniform seed discharge, comprising a seeding mechanism, a seeding mechanism and a controller; the seeding mechanism comprises a cover plate, a seeding ring, an inner cone and an outer cone, the cover plate, the seeding ring and the outer cone are fixedly connected in sequence, the inner cone is coaxially rotatably arranged in the outer cone, a plurality of seed outlet holes are evenly distributed on the circumference of the seeding ring, a plurality of seed outlet tubes are fixedly arranged on the cover plate, one end of the seed outlet tube is connected with the seed outlet hole, and a pressure film sensor is arranged on the inner wall of the seeding ring; the seeding mechanism comprises a seed box, a seed filling tube and a seed filling amount adjusting device, the seed box is arranged above the cover plate, the two ends of the seed filling tube are respectively connected with the inner cavity of the seed box and the seeding ring, and the seed filling amount adjusting device is used for adjusting the size of the flow channel in the seed filling tube; the pressure film sensor and the seed filling amount adjusting device are both electrically connected with the controller; the invention has a simple structure, is light and simple, has a low seed breakage rate, has good seeding uniformity and high seeding accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural sowing machinery, in particular to a centrifugal seeding device with constant seed filling amount and uniform seeding. Background Art

[0002] At present, Chinese medicinal materials sowing machines in my country are still in the research and development stage. Due to the differences in planting agronomy in various regions, the mechanization rate of Chinese medicinal materials sowing in my country is low. As for the sowing of organic Chinese medicinal materials under the forest in Yunnan Province, the existing field Chinese medicinal materials sowing machines are too large to enter the forest for operation, and they are mainly planted manually. The current manual planting method has extremely low mechanization efficiency of sowing and high labor costs. Since the sowing period of Chinese medicinal materials is often around the Spring Festival, there is no one available during the sowing period, resulting in low yields, which restricts the development of the Chinese medicinal materials industry under the forest in Yunnan Province. In order to solve the above problems, it is necessary to develop an automatic sowing machine specifically for the sowing environment of Chinese medicinal materials under the forest in Yunnan Province.

[0003] The seed meter is one of the core components of the seeder and is also the technical key to the seeding of the seeder. Existing field Chinese medicinal material seeders usually use pneumatic pressure hole type seed meters, which use the positive and negative air pressures generated by the airflow to achieve negative pressure seed suction and positive pressure seed discharge. It has the advantages of low requirements on seed size, strong adaptability, and high sowing accuracy at medium and low speeds; but it has high requirements on air pressure and high energy consumption at high speeds, and a high rate of missed sowing when the air pressure is unstable. At the same time, since the fan equipped with the pneumatic seed meter is heavy, the overall seeder is heavy, resulting in excessive compaction of the soil, affecting the emergence rate of Chinese medicinal materials, and affecting the root and stem growth and yield of Chinese medicinal materials. It is not suitable for the light and energy-saving design requirements that need to be met for understory operations in hilly and mountainous areas. In the selection of the seeding device structure of the automatic seeder, the centrifugal seeding device is a relatively light and energy-saving seeding device. However, when the existing centrifugal seeding device is in operation, the number of seeds in its inner cone will gradually decrease as the seeding process progresses. As the seeding process progresses, the seeding accuracy is difficult to control, and it is difficult to achieve precise seeding. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a centrifugal seed metering device with constant seed filling amount and uniform seeding.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A centrifugal seed metering device with constant seed filling amount and uniform seed discharge comprises a seed discharge mechanism, a seed filling mechanism and a controller;

[0007] The seeding mechanism comprises a cover plate, a seeding ring, an inner cone and an outer cone, wherein the cover plate, the seeding ring and the outer cone are coaxially arranged from top to bottom and are fixedly connected in sequence, the large diameter end of the outer cone is open and arranged upward, the inner cone is coaxially and rotatably arranged in the outer cone, the large diameter end of the inner cone is open and arranged upward, the large diameter end of the inner cone is matched with the seeding ring, a plurality of seeding holes are evenly distributed on the circumference of the seeding ring, a plurality of seeding tubes are fixedly arranged on the cover plate, one end of the plurality of seeding tubes is respectively connected with the plurality of seeding holes, and a pressure film sensor is arranged on the inner wall of the seeding ring;

[0008] The seed filling mechanism includes a seed box, a seed filling tube, and a seed filling amount adjustment device. The seed box is arranged above the cover plate, the top end of the seed filling tube is connected to the bottom end of the seed box, a seed filling hole is opened in the center of the cover plate, the bottom end of the seed filling tube is connected to the seed filling hole, and the seed filling amount adjustment device is used to adjust the size of the flow channel in the seed filling tube;

[0009] The pressure film sensor and the seed filling amount regulating device are both electrically connected to the controller.

[0010] Furthermore, the center line of the seed outlet tube is a quasi-parallel curve, and the design curve of the center line of the seed outlet tube is designed to simulate the natural movement trajectory of the seeds when they fly out of the seed outlet hole only under the action of gravity.

[0011] Specifically, the rotation speed of the inner cone is within the range of 120r / min-200r / min, the intersection of the central axis of the seeding ring and the plane where the centers of the plurality of seeding holes are located is taken as the origin of coordinates, the direction from the origin of coordinates to the center of one of the seeding holes is taken as the positive direction of the x-axis, the upward direction is taken as the positive direction of the z-axis, and the direction perpendicular to the x-axis and the z-axis is taken as the y-axis direction, a spatial coordinate system is established, and the equation of the centerline curve of the seeding tube is:

[0012] ,

[0013] In the formula,

[0014] r is the radius of the seeding ring, r=92mm,

[0015] v is the speed of the seed when it leaves the seed hole, and the average value of v is 225.77 mm / s.

[0016] t is the movement time of the seeds in the seed tube, which is a design parameter, <t<0.0664s,

[0017] ɵ is the angle between the line connecting the center of the seed hole and the origin of the coordinate system and the positive direction of the x-axis.

[0018] β is the angle between the plane where the center of the seed hole and the central axis of the seed ring are located and the plane where the seed moves horizontally when leaving the seed hole. The average value of β is 18.17°.

[0019] g is the acceleration due to gravity, and its value is 9806.65 mm / s 2 .

[0020] Specifically, the seed filling amount adjustment device includes a seed filling motor, a seed filling screw, a seed filling slider, and a seed filling baffle. The seed filling screw is rotatably connected to the outer wall of the seed box, the seed filling slider is slidably connected to the outer wall of the seed box, the seed filling slider is threadedly connected to the seed filling screw, one end of the seed filling baffle passes through the side wall of the seed filling tube and is slidably connected to the seed filling tube, the other end of the seed filling baffle is fixedly connected to the seed filling slider, the seed filling motor is used to drive the seed filling screw to rotate, and the seed filling motor is electrically connected to the controller.

[0021] Specifically, the seed-discharging mechanism further includes a frustum, which is coaxially arranged in the inner cone, and the large-diameter end of the frustum is fixedly connected to the small-diameter end of the inner cone.

[0022] Specifically, it also includes a seeding motor, which is used to drive the inner cone to rotate, and the seeding motor is electrically connected to the controller.

[0023] The beneficial effects of the present invention are:

[0024] The centrifugal seeding device with constant seed filling amount and uniform seeding includes a seeding mechanism, a seed filling mechanism and a controller. The seed filling mechanism includes a seed box and a seed filling tube. The seeding mechanism includes a cover plate, a seeding ring, an inner cone and an outer cone. The cover plate, the seeding ring and the outer cone are fixedly connected in sequence, and the inner cone is rotatably arranged in the outer cone. A seed filling hole is opened in the center of the cover plate, one end of the seed filling tube is connected to the bottom end of the seed box, and the other end of the seed filling tube is connected to the seed filling hole. A plurality of seed outlet holes are evenly distributed on the circumference of the seeding ring, and a plurality of seed outlet tubes are fixedly arranged on the cover plate, and one end of the seed outlet tube is connected to the seed outlet hole. The seeds in the seed box enter the inner cone through the seed filling tube. As the inner cone continues to operate, the seed population in the inner cone rises along the inner wall of the inner cone to the position in the seeding ring under the action of centrifugal force, and then is discharged outward through each seed outlet hole and seed outlet tube, completing the centrifugal seeding process. On this basis, a pressure film sensor is arranged on the inner wall of the seed ring, which can monitor in real time the collision force value generated by the collision between the seed population and the inner wall of the seed ring during the operation of the centrifugal seed metering device; a seed filling amount adjusting device is also arranged in the seed filling mechanism, and the seed filling amount adjusting device can adjust the size of the flow channel in the seed filling tube; the pressure film sensor and the seed filling amount adjusting device are both electrically connected to the controller, which can realize dynamic regulation of the seed filling amount under different seeding speeds, thereby improving the seeding uniformity, stability and ability of the centrifugal seed metering device to adapt to a variety of crops and complex environments.

[0025] The center line of the seed tube is a quasi-parabolic curve, and its design curve simulates the natural movement trajectory of the seeds when they fly out of the seed hole under the action of gravity alone. It can reduce the collision of seeds in the seed tube, reduce the damage to the seed flow, and improve the orderliness and implantation uniformity of the seeds; at the same time, it avoids the seeds from being retained in the seed tube, especially at the seed hole position at the end of the seed tube, so as to avoid unnecessary mutual collisions between the seeds at this position and affect the monitoring force value of the pressure film sensor.

[0026] In general, the centrifugal seed meter has a simple and lightweight structure, low seed breakage rate, good seeding uniformity and high seeding accuracy, and is suitable for understory planting operations in hilly and mountainous areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a centrifugal seed metering device with constant seed filling amount and uniform seeding according to the present invention;

[0028] Figure 2 It is a schematic diagram of the internal structure of a centrifugal seed metering device with constant seed filling amount and uniform seeding according to the present invention;

[0029] Figure 3 It is an exploded schematic diagram of the seeding mechanism in the present invention;

[0030] Figure 4 It is a structural schematic diagram of the seed filling mechanism in the present invention;

[0031] Figure 5 It is a schematic diagram of the position of the space coordinate system in the horizontal plane when the seed tube curve is designed in the present invention;

[0032] Figure 6 It is a schematic diagram of analyzing the horizontal movement trajectory of seeds when the seed tube curve is designed in the present invention;

[0033] Figure 7 It is a schematic diagram of the position of the space coordinate system in the vertical plane established when designing the seed tube curve in the present invention;

[0034] Figure 8 It is a schematic diagram of the analysis of the vertical movement trajectory of seeds when the seed tube curve is designed in the present invention;

[0035] In the figure, 10-seed discharging mechanism, 11-cover plate, 12-seed discharging ring, 13-inner cone, 14-outer cone, 15-seed outlet hole, 16-seed outlet tube, 17-seed discharging motor, 18-cone, 20-seed filling mechanism, 21-seed box, 22-seed filling tube, 23-seed filling motor, 24-seed filling screw, 25-seed filling slider, 26-seed filling baffle. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0037] like Figures 1 to 4 As shown, a centrifugal seed metering device with constant seed filling amount and uniform seeding includes a seeding mechanism 10, a seed filling mechanism 20 and a controller.

[0038] The seeding mechanism 10 includes a cover plate 11, a seeding ring 12, an inner cone 13 and an outer cone 14. The cover plate 11, the seeding ring 12 and the outer cone 14 are coaxially arranged from top to bottom and fixedly connected in sequence. The large diameter end of the outer cone 14 is open and arranged upward; the inner cone 13 is coaxially rotatably arranged in the outer cone 14, and the large diameter end of the inner cone 13 is open and arranged upward. The large diameter end of the inner cone 13 is adapted to the bottom end of the seeding ring 12, so that a seeding cavity is formed between the inner cavity of the inner cone 13, the inner cavity of the seeding ring 12 and the cover plate 11. A plurality of seeding holes 15 are evenly distributed on the circumference of the seeding ring 12, and a plurality of seeding tubes 16 are fixedly arranged on the cover plate 11, and one end of the plurality of seeding tubes 16 is respectively connected to the plurality of seeding holes 15. The seed filling mechanism 20 includes a seed box 21 and a seed filling tube 22. The seed box 21 is arranged above the cover plate 11. The top of the seed filling tube 22 is connected to the bottom of the seed box 21. A seed filling hole is provided in the center of the cover plate 11. The bottom of the seed filling tube 22 is connected to the seed filling hole. When in use, the seeds stored in the seed box 21 fall into the above-mentioned seed discharging cavity through the seed filling tube 22. As the inner cone 13 continues to operate, the seeds in the seed discharging cavity are thrown to the inner wall of the inner cone 13 under the action of centrifugal force. Thereafter, the seed flow spirally rises along the inner wall of the inner cone 13 to the seed discharging layer (the position of the seed discharging ring 12). When the seed flow leaves the upper end of the inner cone 13, it still has inertia. The seeds at the seed discharging hole 15 enter the seed discharging tube 16 and are discharged, thereby realizing the centrifugal seed discharging process; other seeds fall into the seed discharging cavity after colliding with the inner wall of the seed discharging ring 12, and enter the next cycle with the rotation of the inner cone 13.

[0039] On this basis, a pressure film sensor is provided on the inner wall of the seeding ring 12, which can monitor in real time the collision force value generated by the collision between the seed population and the inner wall of the seeding ring 12 during the operation of the centrifugal seeding device; a seed filling amount adjustment device is also provided in the seed filling mechanism 20, and the seed filling amount adjustment device can adjust the size of the flow channel in the seed filling tube 22. The pressure film sensor and the seed filling amount adjustment device are both electrically connected to the controller, and the collision force value data monitored by the pressure film sensor is fed back to the controller in real time, and the controller controls the seed filling amount adjustment device according to the set value. When in use, first set the seeding speed (the speed of the inner cone 13) and the corresponding seed filling amount at the speed, that is, set the theoretical pressure value of the pressure film sensor during the working process, and compare the collision force value detected in real time by the pressure film sensor with the set theoretical value. When the detected collision force value is less than the theoretical value, the controller controls the seed filling amount adjustment device to work, increase the flow channel in the seed filling tube 22, and increase the seed filling speed from the seed box 21 to the seed filling cavity. The seed filling speed is greater than the seeding speed, which will increase the number of seeds in the seeding cavity. At the same time, more seeds act on the pressure film sensor to increase the collision force value detected by it until the collision force value increases to the set theoretical value; conversely, when the detected collision force value is greater than the theoretical value, the controller controls the seed filling amount adjustment device to work, so that the flow channel in the seed filling tube 22 becomes smaller, and the seed filling speed from the seed box 21 to the seed filling cavity is reduced, thereby realizing dynamic regulation, so that the seed filling amount is relatively constant at the set seeding speed, and the seeding is more uniform.

[0040] It should be noted that the collision force value monitored by the pressure film sensor is the sum of the centrifugal forces of the seeds colliding with the pressure film sensor at the same time. The detected collision force value reflects the seed density of the centrifugal movement to the seeding layer area, but the collision force value is directly related to the seeding speed. It should be understood that the relative constancy of the above-mentioned seed filling amount does not mean that the seed filling speed is the same as the seeding speed so that the number of seeds in the seeding cavity is always constant. If the seeding speed can always remain unchanged, the constant number of seeds in the seeding cavity can ensure uniform seeding. However, in actual applications, the seeding speed cannot remain unchanged. Depending on the working conditions, the seeding speed will vary within a certain range. When the seeding speed changes, the centrifugal force will also change. Even if the number of seeds in the seeding cavity is constant, uniform seeding cannot be guaranteed.

[0041] When implementing:

[0042] The seeding mechanism 10 also includes a seeding motor 17, which is used to drive the inner cone 13 to rotate. The rotation speed of the seeding motor 17 is the above-mentioned seeding speed. The seeding motor 17 is electrically connected to the controller, and can monitor the seeding speed in real time, and dynamically set different aforementioned theoretical pressure values ​​according to the different monitored seeding speeds, thereby realizing dynamic regulation of the seed filling amount at different seeding speeds, so as to improve the seeding uniformity, stability and ability of the centrifugal seeding device to adapt to a variety of crops and complex environments.

[0043] The seed filling amount adjustment device includes a seed filling motor 23, a seed filling screw 24, a seed filling slider 25 and a seed filling baffle 26. The seed filling screw 24 is rotatably connected to the outer wall of the seed box 21, the seed filling slider 25 is slidably connected to the outer wall of the seed box 21, and the seed filling slider 25 is threadedly connected to the seed filling screw 24, which constitutes a screw nut mechanism. When the seed filling screw 24 rotates, it can drive the seed filling slider 25 to slide. One end of the seed filling baffle 26 passes through the side wall of the seed filling tube 22 and is slidably connected to the seed filling tube 22, and the other end of the seed filling baffle 26 is fixedly connected to the seed filling slider 25. The seed filling motor 23 is electrically connected to the controller. Under the control of the controller, the seed filling motor 23 can drive the seed filling screw 24 to rotate, and then drive the seed filling baffle 26 to slide through the seed filling slider 25 to adjust the length of one end of the seed filling baffle 26 extending into the seed filling tube 22, that is, to achieve the aforementioned adjustment of the size of the flow channel in the seed filling tube 22.

[0044] The seeding mechanism 10 also includes a cone 18, which is coaxially arranged in the inner cone 13, and the large diameter end of the cone 18 is fixedly connected to the small diameter end of the inner cone 13. Since the central area of ​​the inner cone 13 has a relatively small rotational centrifugal force, seeds tend to accumulate in the central area; the cone 18 occupies the central area of ​​the inner cone 13, and the top of the cone 18 is arranged opposite to the seed filling hole of the cover plate 11, which can guide the fallen seeds to spread rapidly around, and after obtaining a relatively large centrifugal force, they quickly spirally rise along the inner wall of the inner cone 13 to the seeding layer (the position of the seeding ring 12) to complete the seeding process, which can avoid accumulation and reduce the occurrence of seed breakage caused by the interaction force of the seeds in the inner cone 13.

[0045] On the seeding ring 12, the seeding hole 15 is designed to be a round hole, and its shape and size are adapted to the shape and size of the Chinese medicinal material seeds to be seeded, so that only one Chinese medicinal material seed can be discharged from the seeding hole 15 at the same time. Different seeding rings 12 can be replaced during application to be suitable for Chinese medicinal material seeds of different types and sizes.

[0046] Furthermore, the center line of the seed tube 16 is a quasi-parabolic curve, and the design curve of the center line of the seed tube 16 is designed to simulate the natural movement trajectory of the seeds under the action of gravity when they fly out of the seed hole 15, so as to reduce the collision of the seeds in the seed tube 16, reduce the damage to the seed flow, and improve the orderliness and implantation uniformity of the seeds; at the same time, it is prevented that the seeds are retained in the seed tube 16, especially in the seed hole 15 at the end of the seed tube 16, so as to avoid unnecessary mutual collisions between the seeds at this position and affect the monitoring force value of the pressure film sensor. Specifically, according to the dynamic analysis, as the inner cone 13 continues to rotate, the seeds in the inner cone 13 move to the seed row layer and fly out of the seed hole 15 naturally, and the movement trajectory of the seeds is a quasi-parabolic curve, which is a synthesis of horizontal movement and vertical movement. In the horizontal direction, due to the interaction between seeds in the population and the collision between the population and the seed metering device, the speed and angle of the seeds when they fly out of the seed hole 15 are changed. When the seeds fly out of the seed hole 15, they are not along the tangent direction of the seed ring 12, but there is a certain angle. The horizontal speed and angle cannot be calculated, and the horizontal motion trajectory needs to be determined by discrete element simulation analysis; in the vertical direction, the seeds are only affected by their own gravity after leaving the seed hole, and the vertical motion trajectory can be calculated. By synthesizing the above-mentioned horizontal motion trajectory and vertical motion trajectory, the natural flight trajectory of the seeds after flying out of the seed hole 15 under the action of only their own weight can be obtained. Designing the seed tube 16 with this synthetic trajectory as the design curve can reduce the collision or retention of seeds in the seed tube 16.

[0047] like Figures 5 to 8 As shown, when designing the seeding tube 16, a seeding device with a radius of the seeding ring 12 of 92 mm, a seeding rotation speed of 120 r / min-200 r / min, and 14 seeding tubes 16 simultaneously discharging seeds is taken as an example.

[0048] By using EDEM discrete element simulation software, the seeding speed of the seed metering device was set to 120r / min, 160r / min and 200r / min, and the motion trajectory of the seeds after leaving the seed hole 15 was analyzed respectively, and it was found that the seeds performed a quasi-parallel motion after leaving the seed hole 15. Among them, at the three speeds of 120r / min, 160r / min and 200r / min, the angles β between the plane where the parallel motion was located and the plane where the center axis of the seed metering device and the center of the seed hole 15 on the seeding ring were 15.6°, 18.5° and 20.4° respectively. The comprehensive average value was taken to determine that at the speed range of 120r / min-200r / min, the angle β between the plane where the parallel motion was located and the plane where the center axis of the seed metering device and the center of the seed hole 15 on the seeding ring were 18.17°.

[0049] Since the theoretically calculated speed of the seeds when leaving the seed hole 15 does not take into account the interaction between the seed population and the seed ring 12 and the interaction between the seeds, resulting in kinetic energy loss, the curve obtained by the theoretical calculation does not match the actual seed movement curve. Here, through the simulation results, the speeds of the seeds when leaving the seed hole 15 at three speeds of 120r / min, 160r / min and 200r / min are 135.83mm / s, 225.79mm / s and 315.68mm / s respectively. The comprehensive average value is taken to determine that the average speed of the seeds when leaving the seed hole 15 in the speed range of 120r / min-200r / min is 225.77mm / s.

[0050] Based on this, the curve of the seed discharge tube 16 is designed to relatively effectively reduce the collision or retention of seeds in the seed discharge tube 16 at a seed discharge speed of 120 r / min-200 r / min.

[0051] Specifically, the intersection of the central axis of the seeding ring 12 and the plane where the centers of the seeding holes 15 are located is taken as the origin of the coordinates, the direction from the origin of the coordinates to the center of one of the seeding holes 15 is taken as the positive direction of the x-axis, the upward direction is taken as the positive direction of the z-axis, and the y-axis direction perpendicular to the x-axis and the z-axis is taken as the direction to establish a spatial coordinate system, then:

[0052] like Figure 6 As shown, in the horizontal movement, after the seed leaves the seed hole 15, it moves at a speed v from point A (x0, y0) to point B (x, y) at a constant speed over a period of time t. Then:

[0053] ,

[0054] Where:

[0055] x0=rcosɵ, y0=rsinɵ, r is the radius of the seed ring 12, r=92mm;

[0056] v is the speed of the seed when it leaves the seed hole 15. When designing a seed meter with a seeding speed of 120 r / min-200 r / min and a radius of the seeding ring 12 of 92 mm, the above average value v=225.77 mm / s is taken;

[0057] ɵ is the angle between the line connecting the seed hole 15 and the coordinate origin and the positive direction of the x-axis;

[0058] β is the angle between the plane where the center of the seed hole 15 and the central axis of the seed ring 12 are located, and the plane where the seed moves horizontally when leaving the seed hole 15. When designing a seeding device with a seeding speed of 120r / min-200r / min and a radius of the seed ring 12 of 92mm, the above average value β=18.17° is taken.

[0059] like Figure 8 As shown, in the vertical motion, after the seed leaves the seed hole 15, it moves uniformly accelerated from point A (x0, 0) to point B (x, z) after a period of time t. Then:

[0060] z=-gt 2 / 2

[0061] Where:

[0062] g is the acceleration due to gravity, which is 9806.65 mm / s 2 ;

[0063] t is the time that the seeds move in the seed tube 16, which is the design parameter of the length of the seed tube 16. <t<0.0664s。

[0064] By synthesizing the above horizontal movement and vertical movement, the center line curve equation of the 14 seed tubes 16 can be obtained as follows:

[0065] ,

[0066] Where:

[0067] r=92mm, v=225.77mm / s, β=18.17°, g=9806.65mm / s 2 ; The ɵ values ​​of the 14 seed tubes 16 are 0°, 25.71°, 51.43°, 77.14°, 102.86°, 128.57°, 154.29°, 180°, 205.71°, 231.43°, 257.14°, 282.86°, 308.57°, and 334.29°, respectively; t is a design parameter, 0 <t<0.0664s。

[0068] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A centrifugal seed metering device with constant seed filling amount and uniform seeding, characterized in that: It includes a seed discharging mechanism, a seed filling mechanism and a controller; The seeding mechanism comprises a cover plate, a seeding ring, an inner cone and an outer cone, wherein the cover plate, the seeding ring and the outer cone are coaxially arranged from top to bottom and are fixedly connected in sequence, the large diameter end of the outer cone is open and arranged upward, the inner cone is coaxially and rotatably arranged in the outer cone, the large diameter end of the inner cone is open and arranged upward, the large diameter end of the inner cone is matched with the seeding ring, a plurality of seeding holes are evenly distributed on the circumference of the seeding ring, a plurality of seeding tubes are fixedly arranged on the cover plate, one end of the plurality of seeding tubes is respectively connected with the plurality of seeding holes, and a pressure film sensor is arranged on the inner wall of the seeding ring; The seed filling mechanism includes a seed box, a seed filling tube, and a seed filling amount adjustment device. The seed box is arranged above the cover plate, the top end of the seed filling tube is connected to the bottom end of the seed box, a seed filling hole is opened in the center of the cover plate, the bottom end of the seed filling tube is connected to the seed filling hole, and the seed filling amount adjustment device is used to adjust the size of the flow channel in the seed filling tube; The pressure film sensor and the seed filling amount adjustment device are both electrically connected to the controller; The center line of the seed outlet tube is a quasi-parallel curve, and the design curve of the center line of the seed outlet tube is designed to simulate the natural movement trajectory of the seeds when they fly out of the seed outlet hole only under the action of gravity. The rotation speed of the inner cone is within the range of 120r / min-200r / min. The intersection of the central axis of the seeding ring and the plane where the centers of the seeding holes are located is taken as the origin of the coordinate system. The direction from the origin of the coordinate system to the center of one of the seeding holes is taken as the positive direction of the x-axis, the upward direction is taken as the positive direction of the z-axis, and the direction perpendicular to the x-axis and the z-axis is taken as the y-axis direction. A spatial coordinate system is established, and the equation of the centerline curve of the seeding tube is: ， In the formula, r is the radius of the seeding ring, r=92mm, v is the speed of the seed when it leaves the seed hole, and the average value of v is 225.77 mm / s. t is the movement time of the seeds in the seed tube, which is a design parameter, <t<0.0664s, ɵ is the angle between the line connecting the center of the seed hole and the origin of the coordinate system and the positive direction of the x-axis. β is the angle between the plane where the center of the seed hole and the central axis of the seed ring are located and the plane where the seed moves horizontally when leaving the seed hole. The average value of β is 18.17°. g is the acceleration due to gravity, and its value is 9806.65 mm / s 2 ; The seed filling amount adjustment device includes a seed filling motor, a seed filling screw, a seed filling slider, and a seed filling baffle. The seed filling screw is rotatably connected to the outer wall of the seed box, the seed filling slider is slidably connected to the outer wall of the seed box, the seed filling slider is threadedly connected to the seed filling screw, one end of the seed filling baffle passes through the side wall of the seed filling tube and is slidably connected to the seed filling tube, the other end of the seed filling baffle is fixedly connected to the seed filling slider, the seed filling motor is used to drive the seed filling screw to rotate, and the seed filling motor is electrically connected to the controller; The seed-discharging mechanism further comprises a frustum, which is coaxially arranged in the inner cone, and the large-diameter end of the frustum is fixedly connected to the small-diameter end of the inner cone.

2. A centrifugal seed metering device with constant seed filling and uniform seeding according to claim 1, characterized in that: It also includes a seeding motor, which is used to drive the inner cone to rotate, and the seeding motor is electrically connected to the controller.

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