A negative pressure type rapeseed precision seed metering device based on Bernoulli principle

Abstract

The application discloses a negative pressure type rapeseed precision seed sowing device based on Bernoulli principle and relates to the technical field of seed sowing equipment. The device comprises a shell, a seed cleaning scraper, an end cover, a roller, a vacuum generator and a pneumatic rotary joint. The end cover is installed at the side opening of the shell, the roller is arranged in the cavity formed by the end cover and the shell, the roller is rotationally connected with the shell and the end cover, the transmission shaft is connected with the roller in an interference fit, the vacuum generator and the pneumatic rotary joint are installed in the roller, the air inlet of the vacuum generator is connected with the pneumatic rotary joint, the air inlet of the pneumatic rotary joint is connected with the air outlet of the air pump, and the pneumatic rotary joint is connected to the inner wall of the roller. The seed suction hole is arranged on the barrel wall of the roller, the vacuum port of the vacuum generator is communicated with the seed suction hole, and the seed cleaning scraper is installed in the shell. The seed dropping hole is arranged below the seed cleaning scraper, and the seed dropping hole is arranged below the seed cleaning scraper. The upper surface of the shell is provided with a seed dropping hole. The application has the advantages of compact structure, small volume, low seed breakage rate and easy realization of precision sowing.

Description

Technical Field

[0001] This invention belongs to the field of seed metering equipment technology, and more specifically, relates to a negative pressure precision seed metering device for rapeseed based on Bernoulli's principle. Background Technology

[0002] Rapeseed is an important oilseed crop in my country. Its seeds are small (approximately 1.5 mm in diameter), lightweight, thin-skinned, and highly mobile. It has multiple uses, including as a vegetable, feed, and green manure. Rapeseed is primarily cultivated through manual sowing or mechanical row sowing followed by thinning. Manual sowing is labor-intensive and inefficient, while mechanized sowing reduces labor intensity and improves efficiency and quality. However, traditional row sowing and semi-precision hill sowing methods suffer from high production costs, high labor input, and time-consuming processes. Therefore, developing precision sowing technology is of significant practical importance. The seed metering device is a key component determining the performance of a precision seeder. With the rapid development of precision seeders in China, the performance requirements for precision seed metering devices are gradually increasing, directly affecting the seeder's sowing efficiency, uniformity, and seed damage rate. This research aims to improve the seed filling performance of small-diameter rapeseed, enhance metering accuracy, and reduce seed breakage. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a negative pressure precision seed metering device for rapeseed based on Bernoulli's principle. It has a compact structure, small size, light weight, and simple principle. Compared with other types of seed metering devices, it has a low seed breakage rate and can more easily achieve precision sowing.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A negative pressure precision seed metering device for rapeseed based on Bernoulli's principle includes a shell, a seed cleaning scraper, an end cap, a roller, a vacuum generator, and a pneumatic rotary joint. The shell is a hollow shell with an opening on one side. The end cap is installed at the side opening of the shell. The roller is disposed in the cavity formed by the end cap and the shell. The roller is rotatably connected to the shell via bearings and is also rotatably connected to the end cap via bearings. A drive shaft passes through the roller and is interference-fitted with the roller, driving the roller to rotate together. The vacuum generator and the pneumatic rotary joint are installed inside the roller. The air inlet of the vacuum generator is connected to the pneumatic rotary joint via an air pipe. The air inlet of the pneumatic rotary joint is connected to the air outlet of the air pump via an air pipe. The pneumatic rotary joint is bolted to the inner wall of the drum. The drum wall is provided with a seed suction hole, and the vacuum port of the vacuum generator is connected to the seed suction hole. The seed cleaning scraper is installed inside the outer shell and located diagonally below the drum. Below the seed cleaning scraper is a seed drop port, and above the outer shell is a seed inlet. Seeds enter the outer shell through the seed inlet and are then adsorbed onto the seed suction hole of the drum under the action of the vacuum generator. As the drum rotates, the seed cleaning scraper scrapes off the seeds adsorbed on the drum, and the scraped seeds fall into the seed drop port below the seed cleaning scraper for sowing.

[0006] Preferably, the seed suction hole is divided into two sections along the axial direction: one section is a frustum hole and the other section is a cylindrical hole. Seeds can be adsorbed onto the frustum hole, which can hold 1 / 3 of a seed.

[0007] Preferably, four grooves are evenly provided along the circumference of the inner wall of the drum, and each groove is provided with a seed suction hole. Four vacuum generators are embedded in the grooves and connected to the inner wall of the drum by bolts.

[0008] Preferably, a through hole is provided on the side of the housing for the air pipe connecting the pneumatic rotary joint and the air pump to pass through.

[0009] Preferably, the upper part of the cleaning scraper is an arc structure that is concentric with the drum and close to the outer surface of the drum.

[0010] The beneficial effects of adopting the above technical solution are as follows:

[0011] 1. This invention is based on Bernoulli's principle, using a vacuum generator to create negative pressure, and to suck up and carry seeds, as well as a seed cleaning scraper to drop seeds, thereby achieving precise seed sowing.

[0012] 2. This invention is based on Bernoulli's principle to generate negative pressure to achieve seed suction and then sowing. It is innovative, with a low seed damage rate and high efficiency. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0014] Figure 2This is a schematic diagram of the outer shell structure;

[0015] Figure 3 This is a schematic diagram of the main structure of the drum;

[0016] Figure 4 yes Figure 3 A schematic diagram of the AA cross-sectional structure in the diagram;

[0017] Figure 5 This is a rear view schematic diagram of the roller structure;

[0018] In the diagram: 1. Outer shell; 11. Seed filling area; 12. Transition area; 13. Through hole; 14. Seed feeding area; 15. First threaded hole; 16. Seed cleaning scraper; 17. Seed dropping port; 2. End cap; 3. Bearing; 4. Roller; 41. Seed suction hole; 42. Groove; 43. Second threaded hole; 44. Vacuum generator; 45. Air pipe; 46. Pneumatic rotary joint; 5. Drive shaft. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] like Figure 1 and Figure 5As shown, the seed metering device of the present invention mainly includes a housing 1, a seed cleaning scraper 16, an end cap 2, a roller 4, a vacuum generator 44, and a pneumatic rotary joint 46. The housing 1 is a hollow shell with an opening on one side, and the end cap 2 is installed at the opening on the side of the housing 1. The roller 4 is disposed in the cavity formed by the end cap 2 and the housing 1. The roller 4 is rotatably connected to the housing 1 through a bearing. The roller 4 is also rotatably connected to the end cap 2 through a bearing 3. A drive shaft 5 passes through the roller 4 and is interference-fitted with the roller 4, and the drive shaft 5 drives the roller 4 to rotate together. Four vacuum generators 44 are installed inside the roller 4. The air inlet of the vacuum generator 44 is connected to the pneumatic rotary joint 46 through an air pipe, and the air inlet of the pneumatic rotary joint 46 is connected to the air outlet of the air pump through an air pipe. The pneumatic rotary joint 46 is fixed to the inner wall of the roller 4 by bolts and a first threaded hole 15. A seed suction hole 41 is provided on the cylinder wall of the roller 4, and the vacuum port of the vacuum generator 44 is connected to the seed suction hole 41. The seed suction hole 41 is divided into two sections along the axial direction: a frustum-shaped hole and a cylindrical hole. Seeds are adsorbed onto the frustum-shaped hole, which can hold about one-third of a seed. The frustum-shaped hole facilitates seed adsorption, and its inner side provides support for the seed. The diameter of the cylindrical hole is smaller than the seed diameter to prevent seeds from being adsorbed into the vacuum generator and causing damage. The seed cleaning scraper 16 is installed inside the outer casing 1 and located diagonally below the roller 4. The upper part of the scraper is an arc structure concentric with the roller and close to its outer surface. Below the scraper 16 is a seed drop port 17, and above the outer casing 1 is a seed inlet. Seeds enter the outer casing 1 through the seed inlet and are then adsorbed onto the seed suction hole 41 of the roller 4 under the action of the vacuum generator 44. As the roller 1 rotates, the scraper 16 scrapes off the seeds adsorbed on the roller 1, and the scraped seeds fall along the scraper into the seed drop port below for sowing.

[0021] like Figure 2 As shown, the outer casing 1 is located on the right side of the integrated seed metering device, cooperating with the bearing 3 and the roller 4, and dividing the outer casing 1 into a seed filling area 11, a transition area 12, and a seed feeding area 14. The seed filling area 11 is located in the region approximately from 5 o'clock to 7 o'clock below the center of the inner side of the outer casing 1, the transition area 12 is located in the region approximately from 7 o'clock to 12 o'clock on the left side of the outer casing 1, and the seed feeding area 14 is located in the region approximately from 12 o'clock to 7 o'clock on the right side of the outer casing 1. The through hole 13 and the first threaded hole 15 for installing the pneumatic rotary joint are both located on the inner rear wall of the outer casing 1. The seed cleaning scraper 16 is located in the seed feeding area 14 inside the outer casing 1.

[0022] End cap 2 is located on the left side of the overall seed metering device. The inner ring of bearing 3 mates with roller 4, and the outer ring mates with outer shell 1 and end cap 2 respectively. Roller 4 has four grooves 42 inside for mounting vacuum generators 44, each groove 42 communicating with a seed suction hole 41. Vacuum generator 44 is embedded in the groove 42, and its vacuum port is connected to the frustum-shaped hole of the seed suction hole 41. The second threaded hole 43 is the bolt mounting hole for vacuum generator 44. Vacuum generator 44 is connected to pneumatic rotary joint 46 via air pipe 45, solving the problem of air pipe entanglement during roller 4 rotation. The air inlet of pneumatic rotary joint 46 is connected to the air outlet of air pump via air pipe.

[0023] This invention is based on Bernoulli's principle. High-speed flowing gas enters through the inlet of the vacuum generator 44, passes through the vacuum port, and exits through the outlet. According to Bernoulli's principle, under ideal conditions, at any cross-section of the same flow tube, the sum of the kinetic energy, potential energy, and pressure potential energy of a unit volume of fluid is a constant. Therefore, it can be deduced that for flow at constant height, the greater the flow velocity, the lower the pressure. The pressure decreases at the vacuum port of the vacuum generator, generating negative pressure for seed absorption.

[0024] Sowing process: First, the seeds are placed into the seed filling area 11 from the top of the outer shell 1, and the drive shaft 5 drives the drum 4 to rotate. At the same time, under the influence of the population and the negative pressure of the drum, the rapeseed seeds are adsorbed into the frustum-shaped suction hole 41 by the negative pressure generated by the vacuum generator 44 in the seed filling area 11. The adsorbed seeds rotate with the drum 4 to the transition area 12, where they will not fall off due to the lateral support force of the suction hole and the negative pressure adsorption force. When the drum 4 rotates to the seed feeding area 14, the seeds adsorbed in the suction hole 41 are scraped off by the seed cleaning scraper 16 and fall along the outer contour of the seed cleaning scraper 16 through the seed dropping port 17 to the outside of the seed metering device, thus completing one round of seed metering. This process is repeated to achieve precision seed metering.

[0025] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A negative pressure precision seed metering device for rapeseed based on Bernoulli's principle, characterized in that, It includes an outer shell, a seed cleaning scraper, an end cap, a roller, a vacuum generator, and a pneumatic rotary joint. The outer shell is a hollow shell with an opening on one side. The end cap is installed at the side opening of the outer shell, and the roller is set in the cavity formed by the end cap and the outer shell. The roller is rotatably connected to the outer shell through a bearing, and the roller is also rotatably connected to the end cap through a bearing. The drive shaft passes through the roller and is interference-fitted with the roller. The drive shaft drives the roller to rotate together. A vacuum generator and a pneumatic rotary joint are installed inside the roller. The air inlet of the vacuum generator is connected to the pneumatic rotary joint through an air pipe. The air inlet of the pneumatic rotary joint is connected to the air outlet of the air pump through an air pipe. The pneumatic rotary joint is bolted to the inner wall of the roller. The outer shell is located on the side of the integrated seed metering device, and cooperates with the bearing and roller. The outer shell is divided into a seed filling area, a transition area, and a seed feeding area. The seed filling area is located below the center of the inner side of the outer shell, the transition area is located on one side of the outer shell, and the seed feeding area is located on the other side of the outer shell. The through hole and the first threaded hole for installing the pneumatic rotary joint are both located on the inner rear wall of the outer shell. The seed cleaning scraper is located in the seed feeding area inside the outer shell. The drum wall is provided with seed suction holes, and the vacuum port of the vacuum generator is connected to the seed suction holes. The seed cleaning scraper is installed inside the outer shell and located diagonally below the drum. Below the seed cleaning scraper is a seed drop port, and above the outer shell is a seed inlet. Seeds enter the outer shell through the seed inlet and are then adsorbed onto the seed suction holes of the drum by the action of the vacuum generator. As the drum rotates, the seed cleaning scraper scrapes off the seeds adsorbed on the drum, and the scraped seeds fall into the seed drop port below the seed cleaning scraper for sowing. The seed suction hole is divided into two sections along the axial direction: one section is a frustum hole and the other section is a cylindrical hole. The seed is adsorbed onto the frustum hole, which can hold 1 / 3 of a seed. Four grooves are evenly provided along the circumference of the inner wall of the drum, and each groove has a seed suction hole. Four vacuum generators are embedded in the grooves and connected to the inner wall of the drum by bolts. The side of the housing also has a through hole for the air pipe connecting the pneumatic rotary joint and the air pump to pass through; The upper part of the cleaning scraper is an arc structure that is concentric with the drum and close to the outer surface of the drum.

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