Suction-injection type small-grain seed precision hole-drilling seed meter and machine
Through the Venturi structure and arc design of the bidirectional airflow seed guide device, the collision problem caused by excessive kinetic energy of small seeds is solved, and the continuous fall and uniform distribution of seed flow are achieved, and the seed quality is improved.
Patent Information
- Application Number
- CN202311779690.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-22
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2043-12-22
AI Technical Summary
When used for sowing small-grain seeds, the existing pneumatic precision seeds have frequent collisions due to excessive kinetic energy, making it difficult to ensure continuous fall and uniform distribution of seed flow.
Using a suction spray-type small-grain seed precision hole seeding discharger, through a two-way air flow seed guide device, including a restraint tube and a drainage tube, the Venturi structure and arc design are used, and the seeds are decelerated in the steady-speed section after accelerating in the jet section, and through The drainage tube obtains a horizontal speed, achieves zero-speed seed casting, and reduces the collision between the seed and the tube wall.
It effectively reduces the number of collisions between seeds and seed guide devices and pipe walls, ensures continuous and stable drop of seeds, and realizes uniform distribution of small seeds and precise hole sowing.
Smart Images
Figure CN117480913B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of agricultural machinery, and specifically discloses a disturbance suction air injection type small-grain seed precision hole sowing seed meter and a machine. Background Art
[0002] The traditional pneumatic precision seeding device for small-grain seeds uses negative pressure seed suction and positive pressure seeding to capture and release small-grain seeds, and the positive and negative pressure areas of the seeding device are connected to the discharge and air inlet of the air pump through pipes, that is, the entire seeding device forms a circulating air path under the action of the air pump, pipes, etc. However, during the stable operation of the pneumatic precision seeding device, the negative pressure demand is much greater than the positive pressure, and the air flow of the entire air path is equal. This results in the process of the seeding disc bringing the seeds into the positive pressure seeding area. The small-grain seeds will obtain excess kinetic energy and collide with the seed guide mechanism of the existing seeding device, and then continue to collide with the tube wall during the process of falling along the seeding tube. At the same time, due to multiple influencing factors such as vibration during the operation of the machine and the shaking of the seed guide tube, the collision of small-grain seeds in the seed guide mechanism or the seed guide tube will be aggravated, resulting in discontinuous seed flow and large differences in the interval of falling time, making it difficult to ensure that small-grain seeds are evenly distributed within the sowing row spacing, resulting in uneven individual growth.
[0003] For example, the utility model patent with application number 202220004256X discloses a positive-negative pressure combined soybean precision seeding device, including a rear shell, a seeding shaft and a front shell, the front shell and the rear shell form a cavity, a seeding disk is arranged in the cavity, the partition in the rear shell separates the inner cavity of the rear shell into a positive pressure zone and a negative pressure zone arranged coaxially inside and outside, the air pressure supply device is connected to the positive pressure zone and the negative pressure zone respectively, the upper part of the front shell is provided with a seed box, and the lower end of the front shell is connected with a seed guide tube. In the process of precision seeding of small-particle seeds, the positive-negative pressure combined soybean precision seeding device disclosed by the utility model is used. Since small-particle seeds (such as rapeseed) are lighter than soybean seeds, the seeds are greatly affected by the airflow after being discharged from the seeding disk. In addition, there is no better seed guiding mechanism, which will cause the small-particle seeds to collide continuously, and the continuous falling state of the seed flow cannot be guaranteed, and it is difficult to ensure that the small-particle seeds are precisely sown in the row spacing according to the sowing requirements. Based on this, the present application proposes a disturbance suction air injection type small-grain seed precision hole sowing seed meter and sowing machine to solve the technical problems existing in the process of using the existing pneumatic seed meter for precision hole sowing of small-grain seeds. Summary of the invention
[0004] The purpose of the present invention is to provide a disturbance suction air injection type small-grain seed precision hole sowing device and sowing machine to solve the problem that the existing positive and negative pressure combined precision seeding devices are used for sowing small-grain seeds such as rapeseed, and the seeds are constantly colliding, and the continuous falling state of the seed flow cannot be ensured, making it difficult to ensure that the small-grain seeds are precisely hole-sown in the row spacing according to the sowing requirements.
[0005] The present invention is achieved through the following technical solutions:
[0006] A small-grain seed precision hole-drilling device with a disturbed suction air jet, comprising a casing and a seeding disc, wherein the interior of the casing is divided into a positive pressure zone and a negative pressure zone by a partition, the casing is provided with a first airflow inlet corresponding to the positive pressure zone, the seeding disc is rotatably arranged in the casing by a seeding shaft, an end cover is installed at the side end of the casing, a bidirectional airflow seed guiding device is arranged in the end cover, the bidirectional airflow seed guiding device comprises a restraining pipe and a drainage pipe, the restraining pipe comprises a seed flow delivery zone, a seed flow acceleration zone and a seed flow steady speed zone, the The seed flow acceleration zone is a venturi tube structure with wide upper and lower ends and narrow middle, and the upper end is connected to the second air flow inlet on the end cover, the seed flow delivery zone is connected to the side end at the middle position of the seed flow acceleration zone, and is in an oblique trapezoidal shape with wide outside and narrow inside, the outer end seed inlet plane of the seed flow delivery zone is arranged in close contact with the seed discharge plate of the positive pressure zone, and the inner end extends to the central axis of the seed flow acceleration zone, and an air pressure connecting port is opened on the top of the outer end seed inlet plane of the seed flow delivery zone, and the seed flow steady speed zone is connected to the lower end of the seed flow acceleration zone;
[0007] The drainage pipe is connected to the lower end of the seed flow steady speed zone, and includes a transition section, a curve section and a straight section from top to bottom. The transition section is connected to the lower end of the flow steady speed zone, and the straight section is tangent to the bottom of the curve section.
[0008] As a further configuration of the above scheme, the first air flow inlet and the second air flow inlet are connected to a multi-way pipe, and a regulating valve is provided on the multi-way pipe connected to the first air flow inlet; through the design of the above-mentioned regulating valve, the size of the airflow delivered into the first air flow inlet and the second air flow inlet in the air path suction can be adjusted and controlled.
[0009] As a specific setting of the above scheme, the middle throat height of the seed flow acceleration zone is 50 mm, the throat width is 20 mm, the contraction angle of the upper part of the seed flow acceleration zone is 60°, and the diffusion angle of the lower part is 30°.
[0010] As a specific setting of the above scheme, the plane height of the outer end seed inlet of the seed flow delivery area is 40 mm, the plane height of the inner end feeding port is 15 mm, the lower bottom of the seed flow delivery area is provided with an inclined surface, and the angle between the inclined surface and the horizontal is 30°, and the angle between the lower end of the inclined surface and the inner wall of the throat of the seed flow acceleration zone is 45°.
[0011] As a specific setting of the above scheme, the overall height of the seed flow steady speed zone is 500 mm, and the overall structure adopts an arc segment transition setting.
[0012] As a specific setting of the above scheme, the curve trajectory equation of the curved section in the drainage tube is 1; wherein x and y are centered on the bottom edge of the transition section, the horizontal axis from the center of the circle to the drainage section outlet is the positive direction of the X axis, and the vertical axis from the center of the circle to the drainage section outlet is the positive direction of the Y axis, and the unit is mm.
[0013] As a specific setting of the above scheme, θ in the curve trajectory equation is 50~80°, and R is 90~180.
[0014] The bidirectional airflow seed guiding device disclosed in the present invention can make the seed discharge process go through four stages: blowing section, jet section, steady speed section and drainage section. Among them, the seeds are first disturbed by the seed disc of the pneumatic seeding device, and the seeds are adsorbed and transported from the seed population to the positive pressure area, and then blown to the feeding inlet by positive pressure to reach the throat of the bidirectional airflow seed guiding device. The seeds will be accelerated by the airflow in the jet section and quickly pass through the bidirectional airflow seed guiding device, and then through the drainage pipe to obtain the horizontal speed corresponding to the machine, and the drainage pipe is placed inside the double disc furrow opener to make it drop seeds at a low position, so as to achieve the effect of dropping seeds at zero speed, effectively reduce the collision between seeds and pipe walls and the bounce with the ground, and improve the sowing quality of the seeder.
[0015] At the same time, the lower end of the seed flow delivery area of the constraint tube in the bidirectional airflow seed guide device is directly inserted into the throat, forming a branch-like Venturi constraint tube similar to the Venturi structure, which can make the vertical airflow in the throat pipe maximum when it is at the feeding port position of the seed flow delivery area (refer to the attached Fig. 9 ), while the upper end of the delivery area is connected to the atmospheric pressure through the air pressure connection port. According to the Bernoulli principle, the air pressure will form a pressure gradient force in the direction of the seed flow acceleration zone at the feeding port, capturing the orderly seed flow delivered by air jet. When the seeds are blown out from the feeding port of the delivery area, the seeds can instantly obtain a very large downward movement speed, which can make the speed of the seeds after the throat acceleration reach more than 5m / s, so as to quickly flush the seeds out of the seed flow acceleration zone, ensuring that the blown seeds will not collide with the inner wall of the seed flow acceleration zone. Subsequently, the seeds will reduce their own kinetic energy in the seed flow steady speed zone due to the decrease in flow velocity, reducing the number of collisions between the seeds and the inner wall of the flow steady speed zone during the falling process. Then, according to the seed speed given by the vertical airflow, the curvature range of the lower end drainage tube is set, so that the seeds can obtain the horizontal component speed balance tool while passing through the drainage tube, and achieve near zero speed seeding.
[0016] The present invention also discloses a sowing machine equipped with the above-mentioned air-suction-jet type small-grain seed precision hole-seeding and metering device, comprising a frame, a disturbance suction air-suction-jet type small-grain seed precision hole-seeding and metering device, a double-disc furrowing device and an air path system, wherein a plurality of the disturbance suction air-suction-jet type small-grain seed precision hole-seeding and metering devices are arranged side by side on the frame, and the lower end of the drainage pipe is extended into the double-disc furrowing device;
[0017] The air circuit system includes an air pump, an air supply pipe and an air extraction pipe, wherein the air supply pipe is connected to a first air flow inlet and a second air flow inlet, and the air extraction pipe is connected to a casing corresponding to the negative pressure zone; the design of the air circuit system enables the internal air flow of all air-suction-type small-grain seed precision hole-sowing seeding devices to circulate.
[0018] The seeding machine disclosed in the present invention can send the positive-pressure airflow in the entire air path system to the positive-pressure area and the two-way airflow seed guiding device from two directions respectively through the cooperation between the air-suction-jet type rapeseed hole-seeding seed meter and the two-way airflow seed guiding device, so that the air pressure value in the positive-pressure area can be reduced under the condition that the negative-pressure area has a sufficiently large negative-pressure area, thereby avoiding that the small-particle seeds obtain excessive kinetic energy during the seed blowing process, reducing the number of collisions between the small-particle seeds and the seed guiding device and the pipeline, making the seed flow fall continuously and stably, and ensuring that the small-particle seeds can be evenly distributed according to the sowing requirements within a narrow row spacing.
[0019] As a further configuration of the above solution, a regulating valve is provided on the multi-way pipe connected to the first air flow inlet.
[0020] As a further configuration of the above scheme, the seed drill also includes a rotary tillage device arranged on a frame in front of the double-disc furrowing device, and a furrowing plow is arranged at a middle position of the rotary tillage device.
[0021] As a further configuration of the above scheme, the seeding machine also includes a fertilizer box arranged on the frame, a fertilizer discharge device is arranged at the lower end of the fertilizer box, and a fertilizer guide groove is arranged at the lower end of the fertilizer discharge device.
[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0023] The invention discloses a small-grain seed precision hole-seeding seed metering device with disturbed suction and air injection, which, through the design of a branch-like Venturi structure constraint tube in a bidirectional airflow seed guide device, can enable the small-grain seeds to be accelerated by the airflow injected vertically downward when entering the throat, and quickly pass through the bidirectional airflow seed guide device, thereby avoiding collision between the seeds and the inner wall of the seed guide device, and then when entering the seed flow steady-speed zone, the seeds' own kinetic energy will be reduced due to the reduction in flow velocity, thereby reducing the number of times that the seeds collide with the inner wall of the flow steady-speed zone during the falling process, thereby making the seed flow fall continuously and stably, ensuring that the small-grain seeds can be evenly distributed within the row spacing according to the sowing requirements, thereby realizing precise, stable and uniform sowing of small-grain seeds.
[0024] The present invention also adopts the design of a drainage tube connected to the lower end of the constraint tube, so that the seeds can obtain a horizontal speed corresponding to the machine through the drainage tube. At the same time, the drainage tube is placed inside the double-disc furrow opener to enable it to be planted at a low position, thereby achieving the effect of planting at zero speed, effectively reducing the collision between the seeds and the tube wall and the bouncing with the ground, and improving the sowing quality of the seeder.
[0025] The seed drill disclosed in the present invention can send the positive pressure airflow in the entire air path system to the positive pressure zone and the two-way airflow seed guide device from two directions respectively, to ensure that the negative pressure zone has sufficient negative pressure seed suction conditions, thereby reducing the air pressure value in the positive pressure zone, thereby avoiding continuous collision of small-particle seeds due to excessive kinetic energy during the positive pressure seed blowing process, further ensuring that the seed flow can fall continuously and stably, ensuring that the small-particle seeds can be evenly distributed within the row spacing according to the sowing requirements, and realizing precise hole sowing of small-particle seeds. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.
[0027] Figure 1 It is a three-dimensional structural schematic diagram of the entire seeding machine in the present invention;
[0028] Figure 2 It is a rear view planar structural schematic diagram of the entire seed drill in the present invention;
[0029] Figure 3 For the present invention Figure 1 A schematic diagram of the enlarged structure at A in the middle;
[0030] Figure 4 It is a schematic diagram of the assembly structure of the seed meter and the bidirectional airflow seed guiding device in the present invention;
[0031] Figure 5 It is a schematic diagram and a partial enlarged diagram of the connection between the seed meter and the bidirectional airflow seed guide device in the present invention;
[0032] Figure 6 It is a plan view and an internal cross-sectional plan view of the bidirectional airflow seed guiding device in the present invention;
[0033] Figure 7 For the present invention Figure 6 A schematic diagram of the enlarged structure at B in the middle;
[0034] Figure 8 It is a plan view and an internal cross-sectional plan view of the drainage tube in the present invention;
[0035] Fig. 9 It is a schematic diagram of the airflow direction and flow rate in the bidirectional airflow seed guiding device of the present invention. DETAILED DESCRIPTION
[0036] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.
[0037] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Figures 1 to 9 , and describes the application in detail with reference to embodiments. Example 1
[0038] Example 1 discloses a small-grain seed precision hole sowing device with agitated air jetting. Figure 4 and attached Figure 5 , including a housing 305, the housing 305 is provided with a partition part inside, and the inside of the housing 305 is divided into two areas, a positive pressure area and a negative pressure area, by the partition part. A seeding shaft 304 is provided at the center of the housing 305, and the outer end of the seeding shaft 304 is connected to the transmission device. Seeding discs 303 are installed at both left and right ends of the seeding shaft 304, so that the suction holes of the seeding discs 303 located in the negative pressure area are used to disturb and absorb small particle seeds (such as rapeseed), and then the suction holes with rapeseed absorbed are transmitted to the positive pressure area under the driving action of the seeding shaft 304, and the rapeseed is blown off by the positive pressure airflow in the positive pressure area.
[0039] End covers 301 are installed at both left and right ends of the seeding disc 303, and seed boxes 302 are arranged on the outer surfaces of the end covers 301. The lower end of the seed box 302 is provided with a seeding tube extending into the casing 305. A two-way airflow seed guiding device 1 is installed in the end cover 301 axially aligned with the positive pressure zone. The perturbed suction air jet type small-grain seed precision hole sowing seeding device in this embodiment is a double-station seeding device, and two two-way airflow seed guiding devices 1 are provided and connected to the two ends of the seeding device respectively. Of course, the perturbed suction air jet type small-grain seed precision hole sowing seeding device in this embodiment can also be set as a single-station seeding device, and the two-way airflow seed guiding device 1 is correspondingly set as a single one.
[0040] Reference Figure 3, a first airflow inlet 306 is connected to the housing 305 corresponding to the positive pressure zone, and a second airflow inlet 307 is provided on the end cover 301 located directly above the bidirectional airflow seed guide device 1. The second airflow inlets 307 on both sides and the first airflow inlet 306 are connected to the air supply pipe through a four-way pipe 308, and then the air supply pipe is connected to the air path system. If it is a single-station seed metering device, a three-way pipe is used for connection. At the same time, in order to control the distribution of airflow, a regulating valve 309 is also provided on the four-way pipe 308 connected to the first airflow inlet 306. When the airflow distribution size needs to be adjusted, the airflow size entering the first airflow inlet 306 and the second airflow inlet 307 is directly adjusted through the regulating valve 309.
[0041] Reference Figure 5 , Attachment Figure 6 and attached Figure 7 The bidirectional airflow seed guiding device 1 includes a constraint tube 101 and a drainage tube 102 connected up and down. Among them, the constraint tube 101 includes a seed flow delivery area a, a seed flow acceleration area b and a seed flow steady speed area c. The seed flow acceleration area b is vertically fixedly installed inside the end cover 301 as a whole, and its upper end opening is aligned and connected with the second air flow inlet 307 up and down, and the whole adopts a venturi tube-like structure. In the specific design, the throat height of the seed flow acceleration area b is set to 50mm, and the throat width is set to 20mm. At the same time, the upper contraction angle of the venturi structure of the seed flow acceleration area b is set to 60°, and the lower diffusion angle is set to 30°.
[0042] The seed flow delivery zone a is arranged on the throat side of the seed flow acceleration zone b, and its cross-sectional shape is an inclined trapezoid, the seed inlet at the outer end is a plane and the height is set to 40mm, then the seed inlet at the outer end of the seed flow delivery zone a is fitted with the surface of the seeding plate 303 in the positive pressure zone, and an air pressure connection port 310 is opened at the top of the plane of the seed inlet at the outer end of the seed flow delivery zone b. The inner end of the seed flow delivery zone a extends to the throat axis of the seed flow acceleration zone b, and its inner end feeding port is also a plane and the height is set to 15mm. At the same time, the lower bottom of the seed flow delivery zone a is provided with an inclined plane, and the angle between the inclined plane and the horizontal is set to 30°, and the lower end of the inclined plane is set at a 45° angle with the inner wall of the throat of the seed flow acceleration zone b. Finally, the seed flow steady speed zone c is connected to the lower end of the seed flow acceleration zone b, and the overall structure adopts a circular arc segment transition, and the overall height of the seed flow steady speed zone c is set to 500mm.
[0043] Reference Figure 5 and attached Figure 8, a fastening bolt hole is opened on the drainage tube 102, and then after the drainage tube 102 is inserted into the plug-in slot at the lower end of the constraint tube 101, it is fixed by fastening bolts. In the specific design, the overall curve of the drainage tube 102 is composed of the transition section ob and the drainage section ocd, and the cd section is tangent to the bottom of the oc section. With the bottom edge of the transition section ob as the center of the circle, the horizontal axis from the center of the circle to the drainage section outlet is the positive direction of the X axis, and the vertical axis from the center of the circle to the drainage section outlet is the positive direction of the Y axis. The equation of the curve segment oc in the specific drainage tube 102 is: ; Among them, θ is set between 50~80°, R is set between 90-180mm, and θ in this embodiment is preferably 60°, and R is set to 180mm.
[0044] In order to verify that the aspiration-inhalation-type small-grain seed precision hole-seeding seed meter disclosed in this embodiment 1 has the effect of precise and stable sowing compared with the traditional seed meter, the following verification experiment was conducted. The experimental conditions are to keep the structure of the seed meter consistent, and use the seed guide tube type seed guide device in the 202220004256X patent to compare with the two-way airflow seed guide device 1 in this embodiment. The qualified rate of the number of seeds in the hole can reach 98%, and the minimum qualified rate of the number of seeds in the hole is 94.8%, which is 4~8% higher than that of the traditional seed guide device. The specific experimental variables and evaluation indicators are shown in the following table.
[0045] Table 1 Test results of precision hole sowing performance of seed metering device:
[0046]
[0047] It can be seen from the above verification experimental data results that the bidirectional airflow seed guide device 1 in this embodiment 1 has a lower hole rate than the traditional seed guide device under different seed disc rotation speeds and working negative pressure conditions, and a higher hole particle number qualified rate than the traditional seed guide device, which has a better precision hole seeding effect. Example 2
[0048] Example 2 discloses a sowing machine equipped with the small-grain seed precision hole sowing device of Example 1, as shown in the attached Figure 1 and attached Figure 2 , including a frame 2, on which a row of disturbing suction air-jet type small-grain seed precision hole-seeding seed-metering devices 3 are installed, and a two-way airflow seed guide device 1 is connected to the left and right ends of each disturbing suction air-jet type small-grain seed precision hole-seeding seed-metering device 3. A row of double-disc furrowing devices 4 are installed on the frame located below the disturbing suction air-jet type small-grain seed precision hole-seeding seed-metering device 3, and then the lower end of the two-way airflow seed guide device 1 is extended into the corresponding double-disc furrowing device 4 for setting.
[0049] An air path system is installed on the frame 2, and the air path system includes an air pump 5, an air supply pipe 501 and an air extraction pipe 502. One ends of the multiple air supply pipes 501 converge at the air outlet end of the air pump 5 and are connected to the air pump, and the other ends are connected to the four-way pipe 308 on the corresponding disturbed suction air-jet type small-grain seed precision hole-seeding seed-metering device 3. Through the action of the air pump 5, a high-speed airflow can be introduced into each air supply pipe 501, and then the high-speed airflow enters the second airflow inlet 307 on both sides of the disturbed suction air-jet type small-grain seed precision hole-seeding seed-metering device 3 and the first airflow inlet 306 in the middle through the four-way pipe 308. The airflow introduced into the first airflow inlet 306 can enter the positive pressure area inside the seed-seeding device to realize positive pressure seed blowing, and the airflow introduced into the second airflow inlet 307 enters the corresponding two-way airflow seed guiding device 1 to realize high-speed airflow seed guiding during the seeding process. One end of the multiple exhaust pipes 502 converges to the exhaust end of the air pump 5 and is connected to the air pump, and the other end is connected to the negative pressure area in the corresponding disturbed suction air injection type small-grain seed precision hole sowing seeding device 3, which can provide the seeding device with sufficient seed suction negative pressure to ensure that the small-grain seeds can be accurately captured and adsorbed in the suction holes of the seeding plate 303.
[0050] A rotary tillage device 6 is installed at the lower end of the frame 2 in front of a row of double disc furrowing devices 4. The rotary tillage device 6 includes a rotary tillage shaft and rotary tillage blades. A plurality of rotary tillage blades are fixedly arranged in a knife seat on the outer circumference of the rotary tillage shaft by bolts and other connecting parts, and then a furrowing plow 10 is arranged at the middle position of the rotary tillage device 6. A fertilizer box 7 is installed on the frame 2 above the rotary tillage device 6. A plurality of fertilizer discharge devices 8 arranged side by side are arranged at the lower end of the fertilizer box 7, and a fertilizer guide groove 9 with a wide upper part and a narrow lower part is connected to the lower end of each fertilizer discharge device 8.
[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A small-grain seed precision hole-seeding device with a disturbed suction air jet, comprising a housing and a seeding disc, wherein the interior of the housing is divided into a positive pressure zone and a negative pressure zone by a partition, and a first air flow inlet corresponding to the positive pressure zone is arranged on the housing, and the seeding disc is rotatably arranged in the housing by a seeding shaft, characterized in that: An end cover is installed at the side end of the casing, and a two-way airflow seed guiding device is arranged in the end cover, and the two-way airflow seed guiding device includes a constraint tube and a drainage tube, and the constraint tube includes a seed flow delivery area, a seed flow acceleration area and a seed flow steady speed area, and the seed flow acceleration area is a venturi tube structure with wide upper and lower ends and narrow middle, and the upper end is connected to the second air flow inlet on the end cover, and the seed flow delivery area is connected to the side end at the middle position of the seed flow acceleration area, and is in an oblique trapezoidal shape with wide outside and narrow inside, the outer end seed inlet plane of the seed flow delivery area is arranged to fit the seed discharge disk in the positive pressure area, and the inner end extends to the central axis of the seed flow acceleration area, and an air pressure connecting port is opened at the top of the outer end seed inlet plane of the seed flow delivery area, and the seed flow steady speed area is connected to the lower end of the seed flow acceleration area; The drainage pipe is connected to the lower end of the seed flow steady speed zone, and the drainage pipe includes a transition section, a curve section and a straight section from top to bottom, the transition section is connected to the lower end of the flow steady speed zone, and the straight section is tangent to the bottom of the curve section; The first air flow inlet and the second air flow inlet are connected to the air supply pipe in the air path system.
2. The perturbed suction air jet small seed precision hole sowing seed metering device according to claim 1, characterized in that: The first airflow inlet and the second airflow inlet are connected to a multi-way pipe, and a regulating valve is arranged on the multi-way pipe connected to the first airflow inlet.
3. The perturbed suction air jet small seed precision hole sowing seed metering device according to claim 1, characterized in that: The middle throat height of the seed flow acceleration zone is 50 mm, the throat width is 20 mm, the contraction angle of the upper portion of the seed flow acceleration zone is 60°, and the diffusion angle of the lower portion is 30°.
4. The aspiration-injection-type small-grain seed precision hole-seeding device according to claim 3 is characterized in that: The plane height of the outer end seed inlet of the seed flow delivery area is 40 mm, and the plane height of the inner end feeding port is 15 mm. The lower bottom of the seed flow delivery area is provided with an inclined surface, and the angle between the inclined surface and the horizontal is 30°, and the angle between the lower end of the inclined surface and the inner wall of the throat of the seed flow acceleration area is 45°.
5. The perturbed suction air jet type small seed precision hole sowing seed metering device according to claim 4, characterized in that: The overall height of the seed flow steady speed zone is 500 mm, and the overall structure adopts an arc segment transition setting.
6. The aspiration-injection-type small-grain seed precision hole-seeding device according to claim 1, characterized in that: The curve trajectory equation of the curve segment in the drainage tube is: ; Where x and y are centered on the bottom edge of the transition section, the horizontal axis from the center of the circle to the outlet of the drainage section is the positive direction of the X axis, and the vertical axis from the center of the circle to the outlet of the drainage section is the positive direction of the Y axis, and the unit is mm.
7. The perturbed suction air jet type small seed precision hole sowing and metering device according to claim 6, characterized in that: In the curve trajectory equation, θ is 50-80°, and R is 90-180°.
8. A sowing machine equipped with the small-grain seed precision hole sowing and metering device according to any one of claims 1 to 7, characterized in that: It comprises a frame, a disturbance suction air jet type small-grain seed precision hole sowing and metering device, a double disc furrowing device and an air circuit system, wherein a plurality of the disturbance suction air jet type small-grain seed precision hole sowing and metering devices are installed side by side on the frame, and the lower end of the drainage pipe is extended into the double disc furrowing device; The air circuit system includes an air pump, an air supply pipe and an air extraction pipe. The air supply pipe is connected to the first air flow inlet and the second air flow inlet, and the air extraction pipe is connected to the casing corresponding to the negative pressure area.
9. The seed drill according to claim 8, characterized in that: The seed drill also includes a rotary tillage device arranged on a frame in front of the double-disc furrowing device, and a furrowing plow is arranged at the middle position of the rotary tillage device.
10. The seed drill according to claim 8, characterized in that: The seeding machine also includes a fertilizer box arranged on the frame, a fertilizer discharge device is arranged at the lower end of the fertilizer box, and a fertilizer guide groove is arranged at the lower end of the fertilizer discharge device.