Profiling single body for corn triangular final singling mode air suction type seed metering and seeding machine

Abstract

The invention discloses a profiling monomer for triangular final singling mode air-suction type seed metering of corn and a seeder, the profiling monomer comprises a rack, air-suction type seed metering devices, a soil covering wheel and a press wheel, the two air-suction type seed metering devices are symmetrically arranged on the rack, the two air-suction type seed metering devices are coaxially linked and drive suckers in the two air-suction type seed metering devices to rotate, and the soil covering wheel and the press wheel are arranged on the rack. Connecting holes connected with a through shaft are formed in the suckers, a radial deflection angle is formed between the connecting holes in the two suckers, the through shaft is linked with a transmission shaft linked with a driving mechanism through a reverser, a disc furrow opener, a press wheel and a soil covering wheel are arranged on the rack, and the disc furrow opener and the press wheel correspond to each other front and back; the rotating shafts and the suckers between the two air-suction type seed-metering devices are integrally deflected into the rotating shafts which do not deflect and only the suckers deflect, so that the exposed rotating shafts correspond to each other, the two air-suction type seed-metering devices can be conveniently connected through shafts, only the suckers with connecting holes with different deflection angles need to be replaced when the deflection angles are adjusted, and the operation is simple and convenient. And the rotating shaft does not need to be operated.

Description

Technical Field

[0001] The invention relates to the technical field of agriculture, and in particular to a contoured monomer and a seeder for pneumatic seeding in a triangular seedling determination mode for corn. Background Art

[0002] In the corn triangle seedling determination mode for small double-row staggered sowing of corn, the commonly used seed metering device was the spoon wheel type seed metering device before. Since the air-suction seed metering device is more accurate in seeding precision, it is gradually being applied to this sowing mode. However, the existing air-suction seed meters all form a staggered deflection angle by deflecting the rotating shaft together with the suction cup as a whole, thereby changing the seed placement time to form small double-row staggered sowing. However, in actual use, since there is a deflection angle between the rotating shafts of the two air-suction seed meters, this overall deflection scheme is not convenient for coaxial connection between the two air-suction seed meters during production, installation and later maintenance. If each air-suction seed meter is equipped with a transmission mechanism for separate driving, the number of transmission mechanisms used is increased, resulting in complex structure and high cost. Summary of the invention

[0003] The technical problem to be solved by the present invention is that the coaxial connection of the rotating shafts of the existing air-suction seed metering device is inconvenient.

[0004] In order to solve the above technical problems, the present invention provides a technical solution: a contoured monomer for air-suction seeding in a triangular seedling determination mode of corn, comprising a frame, an air-suction seeding device, a covering wheel and a pressing wheel, wherein the two air-suction seeding devices are symmetrically arranged on the frame, and the two air-suction seeding devices are linked by a through-shaft, and drive the suction cups in the two air-suction seeding devices to rotate synchronously, and a connecting hole connected to the through-shaft is arranged on the suction cup, and a connecting hole on the suction cup rotates along the through-shaft in a direction parallel to the through-shaft. The suction cup is deflected clockwise at an angle a, and the connecting hole on the other suction cup is deflected counterclockwise at an angle b around the through shaft. A sprocket or a commutator is provided on the through shaft, and a sprocket transmission or a transmission shaft transmission is performed with the driving mechanism. A disc furrow opener is provided on the frame under the air-suction seeding device, and the seeding port of the seeding device is located between two discs in the disc furrow opener. The pressing wheel is arranged between the two disc furrow openers, and the covering wheel is arranged on the frame behind the disc furrow opener, and the disc furrow opener and the pressing wheel correspond to each other front and back.

[0005] Furthermore, the angle a and the angle b are both 2.5-10°.

[0006] Furthermore, the through shaft is cut in the middle and is detachably connected to opposite sides of the sprocket or the commutator.

[0007] Furthermore, connection holes for adjusting the spacing between the two air-suction seeding devices are provided on the front and rear sides of the frame, and the connection holes are at least two groups corresponding to each other. The covering wheel is connected to the connection holes on the rear side of the frame through a profiling mechanism.

[0008] Furthermore, a drip tape placement rack is provided on the frame, a drip tape furrow opener and a drip tape guide wheel are provided on the frame between the disc furrow opener and the covering wheel, and the pressing wheel, the drip tape furrow opener and the drip tape guide wheel correspond to each other front to back.

[0009] To solve the above technical problems, the present invention provides another technical solution: a seeder for pneumatic seeding in a triangular seedling mode of corn, comprising a traction frame, a ground wheel, a sowing unit and an air suction fan, wherein the sowing unit is a contoured unit for pneumatic seeding in a triangular seedling mode of corn as described above, and is characterized in that at least two of the sowing units are arranged side by side on the traction frame through a four-linkage, the ground wheel is connected to the traction frame through a connecting frame, the ground wheel is linked to a transmission on the connecting frame through a chain, the transmission drives the commutator to rotate synchronously through a driving mechanism, and the air suction fan is arranged on the traction frame.

[0010] Furthermore, there are at least two ground wheels, and the input shafts of two transmissions are connected through the shaft and linked with the chain, and the output shafts of the two transmissions are connected through the shaft and linked with the driving mechanism.

[0011] Furthermore, the driving mechanism includes a second sprocket or a second commutator, the second sprocket or the second commutator is arranged on the driven shaft, the second sprocket is linked to the sprocket through a chain, and the second commutator is linked to the commutator through a transmission shaft.

[0012] Furthermore, a fertilizer box and a fertilizer leg are provided on the traction frame, and the fertilizer box and the fertilizer leg are connected through a hose.

[0013] Furthermore, a rotary tillage shaft linked to a gearbox is arranged on the traction frame in front of the fat leg, and rotary tillage blades are arranged on the rotary tillage shaft. The rotary tillage blades are evenly arranged on the rotary tillage shaft or the rotary tillage blades are divided into multiple groups and multiple groups of rotary tillage blades are arranged on the rotary tillage shaft at intervals, and each group of rotary tillage blades corresponds to the front and back of the air-suction sowing unit.

[0014] The beneficial effects of the present invention are: The present application is modified on the basis of the existing air-suction seed-metering device, and the rotating shaft and the suction cup between the two air-suction seed-metering devices are deflected as a whole, so that the rotating shaft does not deflect but only the suction cup deflects, so that the exposed rotating shafts correspond to each other, and there is no deflection angle, which is convenient for the coaxial connection of the two air-suction seed-metering devices. The rotating shafts in the two air-suction seed-metering devices are changed into a through shaft to prevent the coaxial connection and installation errors of the two air-suction seed-metering devices. When adjusting the deflection angle, it is only necessary to replace the suction cups with connection holes with different deflection angles, and there is no need to operate the rotating shaft; the covering wheel and the seed-metering device are both hinged to the frame through a profiling mechanism, and the covering wheel and the seed-metering device are pressed on the ground by their own gravity and springs, so that the covering wheel and the seed-metering device as a whole float up and down according to the terrain, thereby ensuring the sowing quality; the transmission and the ground wheel are connected as a whole, and the power of the ground wheel is directly transmitted to the input shaft of the transmission through a chain, and then the output shaft of the transmission drives the air-suction seed-metering device uniformly through a sprocket or a coupling. The air-suction seeding device can be driven by one transmission to complete the speed adjustment, which is convenient to operate and reduces the cost. The integrated design also saves the internal space of the seeding machine and reduces the interference with other equipment during maintenance. The input shafts of the two transmissions are connected through the shafts, and the output shafts are connected through the shafts. When the ground is uneven, when one ground wheel does not contact the ground and rotates, the air-suction seeding device can still be driven by the other ground wheel. A drip irrigation belt placement rack is arranged on the frame, and the drip irrigation belt is laid on the ground through a drip irrigation belt furrow opener and a drip irrigation belt guide wheel, which is convenient to operate. The fertilizer leg performs fertilization operation to complete the integrated operation of fertilization, sowing and drip irrigation belt laying. The setting of the rotary tillage blade can perform rotary tillage operation on the land, realize the effects of straw crushing and soil tillage, and is convenient for sowing operation. A plurality of groups of rotary tillage blades are arranged at intervals on the rotary tillage shaft, and each group of rotary tillage blades corresponds to the front and rear of the air-suction seeding unit. Only the area to be sown needs to be rotary tilled, which reduces the rotary tillage area and reduces the damage to the soil structure.

[0015] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only five of the drawings of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 The structure of the air-suction seeding unit in this application is shown in FIG. Figure 1 .

[0018] Figure 2 The structure of the air-suction seeding unit in this application is shown in FIG. Figure 2 .

[0019] Figure 3 The structure of the air-suction seeding unit in this application is shown in FIG. Figure 3 .

[0020] Figure 4 This is a schematic diagram of the structure of the air-suction staggered seeder for this application.

[0021] Figure 5 This is a schematic diagram of the structure of the ground wheel.

[0022] In the figure, B1-air suction seed metering device, B2-covering wheel, B3-pressing wheel, B4-disc furrow opener, B5-frame, B6-profiling mechanism, B7-commutator, B8-through shaft, B9-drip irrigation tape placement rack, B10-drip irrigation tape furrow opener, B11-drip irrigation tape guide wheel, B12-connecting hole.

[0023] A-traction frame, B-seeding unit, C-ground wheel, D-connecting frame, E-chain, F-transmission, G-input shaft, H-output shaft, J-second commutator, K-air suction fan, L-four-link, M-fat leg. DETAILED DESCRIPTION

[0024] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0025] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0026] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes, and are not used to limit the scope of these messages or information. Embodiment 1

[0027] like Figure 1-2As shown, a profiling unit for air-suction seeding in a triangular seedling determination mode for corn comprises a frame B5, an air-suction seeding device B1, a covering wheel B2 and a pressing wheel B3. Two air-suction seeding devices B1 are symmetrically arranged on the frame B5, and the two air-suction seeding devices B1 are linked by a through shaft B8, and drive the suction cups in the two air-suction seeding devices B1 to rotate synchronously. The suction cups are provided with connecting holes connected to the through shaft B8. The connecting hole on one suction cup is deflected clockwise around the through shaft B8 by an angle a. When the suction cup is installed on the through shaft B8, the suction cup is deflected clockwise around the through shaft B8 by an angle a as a whole. The connecting hole on the other suction cup is deflected counterclockwise around the through shaft B8 by an angle b. When the suction cup is installed on the through shaft B8, the suction cup is deflected clockwise around the through shaft B8 by an angle b as a whole. A sprocket or a commutator B7 is provided on the through shaft B8. , and the driving mechanism is driven by a sprocket or a transmission shaft. A disc furrow opener B4 is arranged on the frame B5 under the air-suction seed metering device B1, and the seed discharge port of the air-suction seed metering device B1 is located between the two discs in the disc furrow opener B4. The pressing wheel B3 is arranged between the two disc furrow openers B4 (playing the role of pressing and limiting the depth), and the covering wheel B2 is arranged on the frame B5 behind the disc furrow opener B4, and the disc furrow opener B4 and the pressing wheel B3 correspond to each other front and back; the rotating shaft and the suction cup between the two air-suction seed metering devices B1 in the prior art are deflected as a whole so that the rotating shaft does not deflect but only the suction cup deflects, so that the exposed rotating shafts correspond to each other, which is convenient for through-axis connection of the two air-suction seed metering devices B1, and the rotating shafts in the two air-suction seed metering devices B1 are changed into a through-axis B8, so as to prevent the through-axis connection and installation errors of the two air-suction seed metering devices B1.

[0028] Among them, angle a and angle b are both 2.5-10°, preferably 2.5°, 5°, 7.5° and 10°; when adjusting the seed dropping time, it is only necessary to replace the suction cup with connecting holes with different deflection angles, and there is no need to replace or rotate the through shaft B8.

[0029] Among them, a drip irrigation tape placement rack B9 is arranged on the frame B5, a drip irrigation tape furrow opener B10 and a drip irrigation tape guide wheel B11 are arranged on the frame B5 between the disc furrow opener B4 and the covering wheel B2, and the pressing wheel B3, the drip irrigation tape furrow opener B10 and the drip irrigation tape guide wheel B11 correspond to each other front and back; a drip irrigation tape placement rack B9 is arranged on the frame B5, and the drip irrigation tape is laid between the small double-row corns through the drip irrigation tape furrow opener B10 and the drip irrigation tape guide wheel B11, which improves the utilization rate of water and fertilizer and is easy to operate. Embodiment 2

[0030] like Figure 1 and 2As shown, this embodiment is obtained by changing the connection method of technical features such as the through shaft B8 and the commutator B7 on the basis of the first embodiment. The remaining technical features are the same as those of the first embodiment, and the similarities are not repeated here. Among them, the difference between this embodiment and the first embodiment is that the through shaft B8 is cut in the middle and is detachably connected to the opposite sides of the commutator B7.

[0031] In this embodiment, a detachable connection between two air-suction seed-metering devices B1 is realized. This connection is more flexible. Sleeves that are sleeved on the rotating shaft of the air-suction seed-metering device B1 are arranged on opposite sides of the commutator B7. At this time, there is no deflection angle between the sleeves on opposite sides of the commutator B7, which is convenient for connection with the rotating shaft. Embodiment 3

[0032] like Figure 1 and 2 As shown, this embodiment is obtained by adding technical features such as connecting holes B12 and a profiling mechanism B6 on the basis of the second embodiment. The remaining technical features are the same as those of the first embodiment, and the similarities are not repeated here. The difference between this embodiment and the first embodiment is that: connecting holes B12 for adjusting the distance between the two air-suction seeding devices B1 are provided on the front and rear sides of the frame B5, and the connecting holes B12 are at least two groups and correspond to each other front and back, and the covering wheel B2 is connected to the connecting hole B12 on the rear side of the frame B5 through the profiling mechanism B6.

[0033] In this embodiment, each group of connecting holes B12 on the front and rear sides of the frame B5 corresponds to each other (two connecting holes B12 form a group), which is convenient for personnel to adjust the distance between the two air-suction seeding devices B1 and the two covering wheels B2 according to the sowing row spacing, adapting to the sowing operations with different small row spacings in the corn triangular seedling mode, and the preferred adjustment distance is 20-30CM; the four-link L is connected to the traction frame A by U-bolts, so that the sowing unit B moves as a whole on the traction frame A, adapting to the sowing operations with different large row spacings in the corn triangular seedling mode, and the preferred adjustment distance is 55-80CM; angle a and angle b can be adjusted according to the spacing of the other air-suction seeding device B1 to realize triangular seeding and sowing with different row spacings.

[0034] The soil-covering wheel B2 is hinged to the frame B5 through a contouring mechanism B6. The soil-covering wheel B2 is pressed on the ground by its own gravity and a spring, so that the soil-covering wheel B2 as a whole floats up and down according to the terrain, thereby ensuring the sowing quality.

[0035] Among them, after replacing the air-suction sowing unit B disclosed in the above embodiment with the existing sowing machine and improving the structure of the ground wheel C and the transmission F, another technical solution disclosed in the present application is formed, which is: Figure 1-4As shown, a seeder for pneumatic seeding in a triangular seedling determination mode of corn comprises a traction frame A, a ground wheel C, a sowing unit B and an air suction fan K. The sowing unit B is one of the above-mentioned air suction sowing units B, at least two sowing units B are arranged side by side on the traction frame A through a four-link L, the ground wheel C is connected to the traction frame A through a connecting frame D, the ground wheel C is linked to a transmission F on the connecting frame D through a chain E, the transmission F drives a commutator B7 to rotate synchronously through a transmission mechanism, and the air suction fan K is arranged on the traction frame A; the transmission F and the ground wheel C are connected as a whole, the power of the ground wheel C is directly transmitted to the input shaft G of the transmission F through the chain E, and then the output shaft H of the transmission F drives the air suction seeding device B1 uniformly through the driving mechanism, and one transmission F can complete the speed adjustment of all air suction seeding devices B1, which is easy to operate and reduces costs. The integrated design also saves the internal space of the seeder and reduces the interference with other equipment during maintenance.

[0036] Among them, there are at least two ground wheels C, and the input shafts G of the two transmissions F are connected through the shaft and linked with the chain E, and the output shafts H of the two transmissions F are connected through the shaft and linked with the driving mechanism; the driving mechanism includes a second sprocket or a second commutator J, and the second sprocket or the second commutator J is arranged on the driven shaft H, the second sprocket is linked with the sprocket through the chain, and the second commutator J is linked with the commutator B7 through the transmission shaft. The specific transmission through the sprocket or the transmission shaft can be selected according to the usage; the number of transmissions F is adjusted according to the number of ground wheels C, and the output shafts H between multiple transmissions F can be connected through the shaft. When the ground is uneven and one ground wheel C does not rotate in contact with the ground, it can still drive the air-suction seed metering device B1 under the drive of another ground wheel C. One ground wheel C can drive all air-suction seed metering devices B1 to work, thereby ensuring the sowing effect.

[0037] A fertilizer box and a fertilizer leg M are arranged on the traction frame A, and the fertilizer box and the fertilizer leg M are connected by a hose, thereby completing the integrated operation of fertilizing, sowing and laying of drip irrigation belts.

[0038] Among them, a rotary tillage shaft (not shown in the figure) linked to the gearbox is arranged on the traction frame in front of the fat leg, and a rotary tillage blade (not shown in the figure) is arranged on the rotary tillage shaft. The rotary tillage blades are evenly arranged on the rotary tillage shaft or the rotary tillage blades are divided into multiple groups and multiple groups of rotary tillage blades are arranged on the rotary tillage shaft at intervals, and each group of rotary tillage blades corresponds to the front and back of the sowing unit B; the setting of the rotary tillage blades can perform rotary tillage operations on the land, achieve the effects of straw crushing and soil turning, and facilitate sowing operations, and multiple groups of rotary tillage blades are arranged on the rotary tillage shaft at intervals, and each group of rotary tillage blades corresponds to the front and back of the sowing unit B, and only the area that needs to be sown needs to be rotary tilled, thereby reducing the rotary tillage area and reducing damage to the soil structure.

[0039] The process of using the overall technical solution formed by the above embodiments is as follows: the tractor is connected to the traction frame A, the air suction fan K is linked to the hydraulic motor, the hydraulic motor is connected to the hydraulic system of the tractor, and can provide adsorption air pressure to the air suction seed metering device B1, the gearbox is linked to the tractor PTO shaft, the rotary tillage shaft drives the rotary tillage blade to rotate to perform rotary tillage operations on the land, the ground wheel C rotates and drives the input shaft G of the transmission F to rotate through the chain E, the output shaft H of the transmission F is linked to the through shaft B8 through the coupling to drive the air suction seed metering device B1 to work, and after the seeds discharged by the air suction seed metering device B1 fall into the disc-type furrow opener, they are suppressed and covered by the pressing wheel B3 and the covering wheel B2, and the drip irrigation belt is automatically laid under the action of the drip irrigation belt furrow opener B10 and the drip irrigation belt guide wheel B11 to complete the small double-row triangular seedling sowing.

[0040] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A profiling unit for air-suction seeding in a triangular seedling determination mode for corn, comprising a frame, an air-suction seeding device, a covering wheel and a pressing wheel, characterized in that: The two air-suction seed-metering devices are symmetrically arranged on the frame, and the two air-suction seed-metering devices are linked by a through shaft, and drive the suction cups in the two air-suction seed-metering devices to rotate synchronously. The suction cup is provided with a connecting hole connected to the through shaft, the connecting hole on one suction cup is deflected clockwise around the through shaft by an angle a, and the connecting hole on the other suction cup is deflected counterclockwise around the through shaft by an angle b, a sprocket or a commutator is provided on the through shaft, and a sprocket drive or a transmission shaft drive is performed with a driving mechanism, a disc furrow opener is provided on the frame below the air-suction seed-metering device, and the seed discharge port of the seed-metering device is located between the two discs in the disc furrow opener, the pressing wheel is provided between the two disc furrow openers, and the covering wheel is provided on the frame behind the disc furrow opener, and the disc furrow opener and the covering wheel correspond to each other front and back.

2. The profiling monomer for air-suction seeding in a triangular seedling determination mode of corn according to claim 1, characterized in that: Angle a and angle b are both 2.5-10°.

3. The profiling monomer for air-suction seeding in a triangular seedling determination mode of corn according to claim 1, characterized in that: The through shaft is cut in the middle and is detachably connected to the opposite sides of the sprocket or the commutator.

4. The profiling monomer for air-suction seeding in a triangular seedling determination mode of corn according to claim 1, characterized in that: The front and rear sides of the frame are provided with connection holes for adjusting the spacing between the two air-suction seeding devices. The connection holes are at least two groups and correspond to each other. The covering wheel is connected to the connection holes on the rear side of the frame through a profiling mechanism.

5. The profiling monomer for air-suction seeding in a triangular seedling determination mode of corn according to claim 1, characterized in that: A drip irrigation belt placement rack is arranged on the frame, a drip irrigation belt furrow opener and a drip irrigation belt guide wheel are arranged on the frame between the disc furrow opener and the covering wheel, and the pressing wheel, the drip irrigation belt furrow opener and the drip irrigation belt guide wheel correspond to each other front and back.

6. A seeder for pneumatic seeding in a triangular seedling determination mode for corn, comprising a traction frame, a ground wheel, a sowing unit and an air suction fan, wherein the sowing unit is a contoured unit for pneumatic seeding in a triangular seedling determination mode for corn according to any one of claims 1 to 5, characterized in that: At least two of the sowing units are arranged side by side on the traction frame through a four-link connection, the ground wheel is connected to the traction frame through a connecting frame, the ground wheel is linked to a transmission on the connecting frame through a chain, the transmission drives the commutator to rotate synchronously through a driving mechanism, and the air suction fan is arranged on the traction frame.

7. The seeder for corn triangular seedling mode air suction seeding according to claim 6, characterized in that: There are at least two ground wheels, and the input shafts of two transmissions are connected through the shaft and linked with the chain, and the output shafts of the two transmissions are connected through the shaft and linked with the driving mechanism.

8. The seeder for corn triangular seedling mode air suction seeding according to claim 7, characterized in that: The driving mechanism comprises a second sprocket or a second commutator, the second sprocket or the second commutator is arranged on the driven shaft, the second sprocket is linked with the sprocket through a chain, and the second commutator is linked with the commutator through a transmission shaft.

9. The seeder for corn triangular seedling mode air suction seeding according to claim 8, characterized in that: A fertilizer box and a fertilizer leg are arranged on the traction frame, and the fertilizer box and the fertilizer leg are connected through a hose.

10. The seeder for corn triangular seedling mode air suction seeding according to claim 9, characterized in that: A rotary tillage shaft linked to a gearbox is arranged on the traction frame in front of the fat leg, and rotary tillage blades are arranged on the rotary tillage shaft. The rotary tillage blades are evenly arranged on the rotary tillage shaft or the rotary tillage blades are divided into multiple groups and multiple groups of rotary tillage blades are arranged on the rotary tillage shaft at intervals, and each group of rotary tillage blades corresponds to the front and back of the air-suction sowing unit.

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