Seed metering pneumatic seed meter with negative pressure seed suction and positive pressure seed discharge

Abstract

This combined negative pressure seed suction and positive pressure seed dispensing pneumatic seed metering device is a type of agricultural machinery. It features a negative pressure inner chamber supported and fixed on a frame, consisting of a rectangular cross-section ring-shaped seed box, an annular plate, a circular adjusting plate, and a circular sealing plate. Within the negative pressure inner chamber are installed a drive mechanism consisting of an electric motor, drive shaft, and drive bracket; a seed suction mechanism consisting of a seed suction and dispensing annular plate, a seed chamber volume cylinder, and a seed chamber volume adjusting barrel; a seed chamber volume adjusting mechanism consisting of a wheel rod, a grooved cam, and an L-shaped connecting rod; a negative pressure air cut-off mechanism consisting of a barrel sleeve, compression spring, hanging rod, limit seat plate, end cover, and negative pressure air cut-off block; and a positive pressure air dispensing mechanism consisting of a positive pressure air blowing pipe, a flexible hose, a negative pressure air cut-off block, and a seed dispensing pipe. This device achieves a combination of negative pressure seed suction and positive pressure seed dispensing, with adjustable seed dispensing volume, excellent filling and dispensing effect, strong applicability, and a wide range of applications.

Description

Technical Field

[0001] This invention belongs to the field of agricultural machinery and mainly relates to a pneumatic seed metering device. Background Technology

[0002] Pneumatic seed metering devices have become extremely common seed metering components in recent years, especially suitable for use with large, multi-row seeders. However, years of practical application in production have revealed shortcomings in their structural design. Currently used pneumatic seed metering devices can only adapt to one type of seed and a specific seeding rate. When used with different seeds or different seeding rates for the same seed, different seed tray sizes must be used, which not only easily damages the seeder and reduces its efficiency, but also has poor applicability and a limited range. Disassembly and replacement are labor-intensive, time-consuming, and increase operating costs. Furthermore, when using traditional and currently used pneumatic seed metering devices, after the negative pressure suction on the seeds is cut off, the seeds can only be released from the seed tray's holes by their own weight, frequently resulting in seed jamming and significantly reducing the quality of seeding operations. In recent years, various mechanical and pneumatic-assisted seed metering structures have been researched to solve these seed jamming problems. However, many technical issues remain to be overcome and resolved, including complex structures, high failure rates, increased manufacturing costs, poor operational reliability, and limited technical effectiveness. Summary of the Invention

[0003] The purpose of this invention is to address the problems existing in the prior art and, in light of the actual needs of current mechanized agricultural sowing operations for pneumatic seed metering devices, to develop and design a new type of pneumatic seed metering device with a combination of negative pressure seed suction and positive pressure seed metering. This device aims to achieve the following: strong adaptability to different seeds and different sowing rates; wide range of applications; simple and convenient adjustment; good seed unloading and metering effect; low seed jamming rate; and high degree of versatility.

[0004] The purpose of this invention is achieved as follows: A rectangular cross-section broken-ring seed box with a seed inlet hopper is fixedly mounted on a frame, with the broken ring portion of the rectangular cross-section broken-ring seed box located at the bottom. Multiple seed inlet holes are evenly distributed along the circumference on the inner wall of the rectangular cross-section broken-ring seed box. An annular plate and a circular sealing plate are fixedly mounted in the annular holes on both ends of the rectangular cross-section broken-ring seed box, respectively. A circular adjusting plate is rotatably and reciprocally installed within the annular holes of the annular plate. Thus, the rectangular cross-section broken-ring seed box, the annular plate, the circular adjusting plate, and the circular sealing plate constitute a negative pressure inner chamber, enabling negative pressure suction. The positive pressure air blower and the negative pressure suction pipe are respectively installed on the outer walls of the annular plate and the circular sealing plate. The negative pressure suction pipe is connected to the negative pressure inner chamber. A drive shaft and a fixed electric motor are rotatably supported and installed on the middle part of the frame, located on the outer side of the circular sealing plate, via brackets. The electric motor is connected to the drive shaft, which is rotatably inserted into the central holes of the circular sealing plate and the circular adjusting plate. A bushing with a set screw is rotatably fitted on the end of the drive shaft, located outside the circular adjusting plate. The set screw secures the bushing to the drive shaft, and the bushing is integrally fixed to the circular adjusting plate. A drive bracket is fixedly mounted on the drive shaft, located within the negative pressure inner cavity. A seed suction and discharge annular plate is fixedly mounted on the outer circumference of the drive bracket. The outer surface of the seed suction and discharge annular plate is in close contact with the inner wall of the rectangular cross-section broken-ring seed box. Multiple seed delivery holes are evenly distributed along the circumference of the seed suction and discharge annular plate. These seed delivery holes sequentially overlap and communicate with, or are staggered and closed with, the seed inlet holes on the inner wall of the rectangular cross-section broken-ring seed box. A seed chamber volume cylinder is fixedly mounted radially on the inner wall of the seed suction and discharge annular plate and coaxially with the seed delivery holes. A guide sliding hole is opened along the axial direction on the wall plate of the seed chamber volume cylinder. The seed chamber volume adjustment barrel can be axially pulled and moved into the cavity of the seed chamber volume cylinder. The guide column fixed on the outer wall of the seed chamber volume adjustment barrel can be movably inserted into the guide sliding hole. An L-shaped connecting rod and a negative pressure suction hole are fixed on the bottom wall plate of the seed chamber volume adjustment barrel. On the inner wall of the circular adjustment plate, the number of wheel rods is evenly distributed and fixed along the circumference, equal to the number of seed conveying holes on the seed suction and discharge ring plate. A grooved cam is fixed on the wheel rod. The end of the L-shaped connecting rod can be slidably inserted into the cam groove of the grooved cam.A cylindrical sleeve is vertically inverted and fixed on the inner wall of a circular sealing plate, located below the drive shaft. A hanging rod with a limit seat plate is inserted into the center hole of the end cap, circumferentially and radially positioned and axially telescopically movable. The end cap is fixed to the opening of the lower end of the inverted cylindrical sleeve. A compression spring is installed between the outside of the hanging rod and the inner wall of the cylindrical sleeve. The upper and lower ends of the compression spring are in compressive contact with the inner wall of the bottom wall plate of the cylindrical sleeve and the upper end of the limit seat plate, respectively. The lower end of the limit seat plate... The end face and the upper end face of the end cap are in contact with each other in an axial limiting fit or disengagement fit. A negative pressure air cut-off block is fixedly installed on the lower end of the hanging rod. A positive pressure air duct is opened inside the negative pressure air cut-off block. A flexible hose connects the positive pressure inner blowpipe to the air inlet of the positive pressure air duct. The air outlet of the positive pressure air duct is connected in sequence through the negative pressure air intake hole, the seed chamber volume adjustment tank, the seed chamber volume cylinder, and the seed conveying through hole on the seed suction and discharge ring plate to the seed discharge pipe fixed on the bracket. This constitutes a combined negative pressure seed suction and positive pressure seed discharge type adjustable pneumatic seed metering device.

[0005] This invention creates an adjustable seed suction chamber composed of a seed chamber volume cylinder and a seed chamber volume adjustment cylinder, which meets the needs of filling different seeds and different sowing rates. It adopts a negative pressure air cut-off synchronous and positive pressure airflow blowing method to ensure and improve the reliability of seed unloading and discharging operations, avoid and eliminate seed jamming failures. It has the characteristics of novel, unique and reasonable structure, simple, convenient, fast and accurate adjustment of seed chamber volume, strong adaptability to different seeds and different sowing rate requirements, no seed jamming, good filling and discharging effect, high quality, reliable use and low failure rate. It provides technical support for the improvement of the technical performance and product upgrading of pneumatic seed metering devices. Attached Figure Description

[0006] Figure 1 This is a partial three-dimensional cross-sectional schematic diagram of the overall structure of a pneumatic seed metering device with adjustable seed quantity, which combines negative pressure seed suction and positive pressure seed dispensing.

[0007] Figure 2 yes Figure 1 A two-dimensional view in direction A;

[0008] Figure 3 yes Figure 2 B-B section view;

[0009] Figure 4 This is a schematic diagram of the assembly structure of a chamber volume regulating tank;

[0010] Figure 5 This is a schematic diagram of a chamber-volume cylinder structure;

[0011] Figure 6 This is a schematic diagram of the assembly structure of the negative pressure gas shut-off block;

[0012] Figure 7 This is a schematic diagram of the suspension rod structure;

[0013] Figure 8 yes Figure 7 A bottom view;

[0014] Figure 9 yes Figure 7 Top view;

[0015] Figure 10 This is a schematic diagram of the end cap structure;

[0016] Figure 11 This is a schematic diagram of a slotted cam structure.

[0017] Part number description in the image:

[0018] 1. Seed hopper; 2. Rectangular cross-section broken ring seed box; 3. Ring plate; 4. Circular adjusting plate; 5. Drive shaft; 6. Bushing; 7. Negative pressure suction pipe; 8. Circular sealing plate; 9. Drive bracket; 10. Bucket sleeve; 11. Wheel rod; 12. Hanging rod; 13. Groove cam; 14. L-shaped connecting rod; 15. Seed chamber volume adjusting barrel; 15-1. Negative pressure suction hole; 16. Hose; 17. Negative pressure air cut-off block; 17-1. Positive pressure air duct; 18. Top screw; 19. End cap; 20. Seed chamber volume cylinder; 20-1. Guide sliding hole; 21. Seed suction and discharge ring plate; 22. Seed discharge pipe; 23. Bracket; 24. Frame; 25. Electric motor; 26. Positive pressure air blower pipe; 27. Guide column; 28. Limiting seat plate; 29. ​​Compression spring. Detailed Implementation

[0019] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. A combined negative pressure seed suction and positive pressure seed dispensing pneumatic seed dispenser with adjustable seed quantity comprises a rectangular cross-section broken-ring seed box 2 with a seed inlet hopper 1 fixedly mounted on a frame 24. The broken ring portion of the rectangular cross-section broken-ring seed box 2 is located at the bottom. Multiple seed inlet holes are evenly distributed along the circumferential direction on the inner wall of the rectangular cross-section broken-ring seed box 2. An annular plate 3 and a circular sealing plate 8 are fixedly mounted in the annular holes on both ends of the rectangular cross-section broken-ring seed box 2, respectively. A circular adjusting plate 4 is rotatably and reciprocally installed within the annular holes of the annular plate 3. Thus, the rectangular cross-section broken-ring seed box 2, the annular plate 3, the circular adjusting plate 4, and the circular sealing plate 8 constitute a negative pressure inner chamber. A negative pressure suction pipe 7 and... Positive pressure air blower pipes 26 are respectively installed on the outer walls of the annular plate 3 and the circular sealing plate 8. The negative pressure air suction pipe 7 is interconnected with the negative pressure inner chamber. A drive shaft 5 and a fixed electric motor 25 are rotatably supported and installed on the middle part of the frame 24, located on the outer side of the circular sealing plate 8, by a bracket 23. The electric motor 25 is connected to the drive shaft 5. The drive shaft 5 is rotatably inserted into the central holes of the circular sealing plate 8 and the circular adjusting plate 4. A bushing 6 with a set screw 18 is rotatably fitted on the end of the drive shaft 5, located outside the circular adjusting plate 4. The set screw 18 fixes the bushing 6 to the drive shaft 5. The bushing 6 is fixedly integrated with the circular adjusting plate 4. A drive bracket 9 is fixedly mounted on the drive shaft 5 at the inner part of the negative pressure cavity. A seed suction and discharge annular plate 21 is fixedly mounted on the outer circumference of the drive bracket 9. The outer surface of the seed suction and discharge annular plate 21 is in close contact with the inner wall of the rectangular cross-section broken ring seed box 2. Multiple seed conveying holes are evenly distributed along the circumference on the seed suction and discharge annular plate 21. The seed conveying holes on the seed suction and discharge annular plate 21 are sequentially overlapped and connected or staggered and closed with the seed inlet holes on the inner wall of the rectangular cross-section broken ring seed box 2. A seed chamber volume cylinder 20 is fixedly mounted on the inner wall of the seed suction and discharge annular plate 21 along the radial direction and coaxially connected with the seed conveying holes. A guide sliding hole 20-1 is opened axially, and the seed chamber volume adjustment barrel 15 is axially pulled and moved into the cavity of the seed chamber volume cylinder 20. The guide post 27 fixed on the outer wall of the seed chamber volume adjustment barrel 15 is movably inserted into the guide sliding hole 20-1. An L-shaped connecting rod 14 and a negative pressure suction hole 15-1 are fixed on the bottom wall plate of the seed chamber volume adjustment barrel 15. Wheel rods 11 are evenly distributed and fixed on the inner wall of the circular adjustment plate 4 along the circumferential direction, with the number of wheel rods 11 equal to the number of seed conveying holes on the seed suction and discharge annular plate 21. A grooved cam 13 is fixed on the wheel rods 11. The end of the L-shaped connecting rod 14 is slidably inserted into the cam groove of the grooved cam 13.A cylindrical sleeve 10 is vertically inverted and fixed on the inner wall of the circular sealing plate 8, below the drive shaft 5. A hanging rod 12 with a limiting seat plate 28 is inserted into the center hole of the end cover 19, which is circumferentially and radially positioned and axially telescopically movable. The end cover 19 is fixed to the opening of the lower end of the inverted cylindrical sleeve 10. A compression spring 29 is installed between the outside of the hanging rod 12 and the inner wall of the cylindrical sleeve 10. The upper and lower end faces of the compression spring 29 are in compressive contact with the inner wall of the bottom wall plate of the cylindrical sleeve 10 and the upper end face of the limiting seat plate 28, respectively. The lower end face of the limiting seat plate 28 is in contact with the upper end face of the end cover 19, either in an axial limiting fit or a disengaged contact fit. A negative pressure air cut-off block 17 is fixedly installed on the lower end of the hanging rod 12. A positive pressure air duct 17-1 is opened inside the negative pressure air cut-off block 17. A flexible hose 16 connects the positive pressure inner blow pipe 26 to the air inlet of the positive pressure air duct 17-1. The air outlet of the positive pressure air duct 17-1 is connected sequentially through the negative pressure suction hole 15-1, the seed chamber volume regulating barrel 15, the seed chamber volume cylinder 20, and the seed conveying through hole on the seed suction and discharge annular plate 21 to the seed discharge pipe 22 fixed on the bracket 23.

[0020] During operation, seeds are filled from the seed hopper 1 into the rectangular cavity of the rectangular cross-section broken-ring seed box 2. The external negative pressure air source and the pulsating positive pressure air source are connected via the negative pressure suction pipe 7 and the positive pressure blowing pipe 26 to the negative pressure inner chamber formed by the rectangular cross-section broken-ring seed box 2, the annular plate 3, the circular adjusting plate 4, and the circular sealing plate 8, and to the positive pressure air delivery channel formed by the hose 16 and the positive pressure air duct 17-1 on the negative pressure air cut-off block 17. The electric motor 25 is started, and the rotating drive shaft 5 drives the drive bracket 9, which in turn drives the circular adjusting plate 4 to rotate at the same speed via the bushing 6. The drive bracket 9, through the seed suction and discharge annular plate 21, sequentially drives the seed chamber volume cylinder 20, the seed chamber volume adjusting barrel 15, the L-shaped connecting rod 14, the grooved cam 13, and the wheel rod 11 to rotate synchronously with the circular adjusting plate 4. When the seed delivery through hole on the seed suction and discharge annular plate 2 is aligned with the rectangular cross-section... When the seed inlet holes on the inner wall panel of the ring-shaped seed box 2 coincide, the negative pressure suction of the negative pressure inner chamber draws the seeds from the rectangular cross-section ring-shaped seed box 2 through the negative pressure suction hole 15-1 on the seed chamber volume regulating barrel 15, filling the seed chamber volume cylinder 20 and the seed chamber volume regulating barrel 15. When the seed chamber volume regulating barrel 15, filled with seeds, rotates to its lower position and its bottom surface is in close contact with the negative pressure gas cut-off block 17, the negative pressure gas... While the air cut-off block 17 cuts off the negative pressure air intake hole 15-1 from the negative pressure air force in the negative pressure inner chamber, the pulsating positive pressure air is blown from the positive pressure blow pipe 26, the hose 16, and the positive pressure air duct 17-1 on the negative pressure air cut-off block 17 into the seed chamber volume regulating bucket 15 and the seed chamber volume cylinder 20, and blows the seeds into the seed discharge pipe 22 through the seed conveying hole on the seed suction and discharge ring plate 21, thus completing the negative pressure seed suction and positive pressure seed discharge operation process.

[0021] When adjusting the seed chamber volume according to different seeds or different sowing rates, loosen the set screw 18, rotate the bushing 6 on the drive shaft 5, driving the circular adjusting plate 4 to rotate. This, in turn, causes the grooved cam 13 to rotate via the wheel rod 11. The movement of the L-shaped connecting rod 14 within the cam groove of the grooved cam 13 causes the seed chamber volume adjusting barrel 15 to extend or retract within the seed chamber volume cylinder 20, changing the size of the volume cavity. After adjustment, lock the bushing 6 on the drive shaft 5 with the set screw 18. This device achieves stepless adjustment of the seed chamber volume, with high adjustment precision, wide applicability, and strong adaptability.

Claims

1. A pneumatic seed metering device with adjustable seed quantity, combining negative pressure seed suction and positive pressure seed metering, characterized in that: A rectangular cross-section broken-ring seed box (2) with a seed inlet hopper (1) is fixedly mounted on the frame (24). The broken ring part of the rectangular cross-section broken-ring seed box (2) is located at the bottom. Multiple seed inlet holes are evenly distributed along the circumferential direction on the inner wall of the rectangular cross-section broken-ring seed box (2). Annular plates (3) and circular sealing plates (8) are fixedly mounted in the annular holes on both ends of the rectangular cross-section broken-ring seed box (2). A circular adjusting plate (4) is rotatably and circumferentially installed in the annular hole of the annular plate (3). Thus, the rectangular cross-section broken-ring seed box (2), annular plate (3), circular adjusting plate (4), and circular sealing plate (8) form a negative pressure inner chamber. A negative pressure suction pipe (7) and a positive pressure blowing pipe (26) are respectively installed on the annular plate (3) and the ring plate (8). On the outer wall of the circular sealing plate (8), the negative pressure suction pipe (7) is connected to the negative pressure inner chamber; on the middle part of the frame (24), at the outer part of the circular sealing plate (8), the drive shaft (5) and the fixed electric motor (25) are rotatably supported and installed by the bracket (23), respectively. The electric motor (25) is connected to the drive shaft (5). The drive shaft (5) is rotatably inserted into the central hole of the circular sealing plate (8) and the circular adjusting plate (4). On the end of the drive shaft (5), at the outer part of the circular adjusting plate (4), the bushing (6) with the set screw (18) is rotatably fitted. The set screw (18) fixes the bushing (6) to the drive shaft (5). The bushing (6) is fixed to the circular adjusting plate (4) as a whole. A drive bracket (9) is fixedly mounted on the drive shaft (5) at the inner part of the negative pressure cavity. A seed suction and discharge ring plate (21) is fixedly mounted on the outer end of the drive bracket (9). The outer surface of the seed suction and discharge ring plate (21) is in close contact with the inner wall of the rectangular cross-section broken ring seed box (2). Multiple seed conveying holes are evenly distributed along the circumferential direction on the seed suction and discharge ring plate (21). The seed conveying holes on the seed suction and discharge ring plate (21) are sequentially connected to or staggered closed with the seed inlet holes on the inner wall of the rectangular cross-section broken ring seed box (2). A seed chamber volume cylinder (20) is fixedly mounted on the inner wall of the seed suction and discharge ring plate (21) along the radial direction and coaxially connected with the seed conveying holes. A guide is opened along the axial direction on the wall of the seed chamber volume cylinder (20). The seed chamber volume regulating barrel (15) is axially slidably inserted into the cavity of the seed chamber volume cylinder (20) through the sliding hole (20-1). The guide column (27) fixed on the outer wall of the seed chamber volume regulating barrel (15) is movably inserted into the guide sliding hole (20-1). An L-shaped connecting rod (14) and a negative pressure suction hole (15-1) are fixed on the bottom wall plate of the seed chamber volume regulating barrel (15). Wheel rods (11) of the same number as the number of seed conveying holes on the seed suction and discharge ring plate (21) are evenly distributed and fixed on the inner wall of the circular regulating plate (4) along the circumferential direction. A grooved cam (13) is fixed on the wheel rods (11). The end of the L-shaped connecting rod (14) is slidably inserted into the cam groove of the grooved cam (13).A cylindrical sleeve (10) is vertically inverted and fixed on the inner wall of the circular sealing plate (8), below the drive shaft (5). A hanging rod (12) with a limit seat plate (28) is inserted into the center hole of the end cover (19) for circumferential and radial positioning and axial telescopic movement. The end cover (19) is fixed on the opening of the lower end of the inverted cylindrical sleeve (10). A compression spring (29) is installed between the outside of the hanging rod (12) and the inner wall of the cylindrical sleeve (10). The upper and lower ends of the compression spring (29) are in compression contact with the inner wall of the bottom wall plate of the cylindrical sleeve (10) and the upper end of the limit seat plate (28), respectively. The lower end face of the seat plate (28) and the upper end face of the end cover (19) are in contact with each other in an axial limiting fit or disengagement fit. A negative pressure air cut-off block (17) is fixedly installed on the lower end of the hanging rod (12). A positive pressure air duct (17-1) is opened in the negative pressure air cut-off block (17). A hose (16) connects the positive pressure air blowing pipe (26) to the air inlet of the positive pressure air duct (17-1). The air outlet of the positive pressure air duct (17-1) is connected to the negative pressure air intake hole (15-1), the seed chamber volume adjustment barrel (15), the seed chamber volume cylinder (20), the seed conveying through hole on the seed suction and discharge ring plate (21), and the seed discharge pipe (22) fixed on the bracket (23).

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