CN113179711B

CN113179711B - Positive pressure seeder is with ditching earthing device of pressing kind

Info

Publication number: CN113179711B
Application number: CN202110453542.4A
Authority: CN
Inventors: 严伟; 张文毅; 祁兵; 王云霞
Original assignee: Nanjing Research Institute for Agricultural Mechanization Ministry of Agriculture
Current assignee: Nanjing Research Institute for Agricultural Mechanization Ministry of Agriculture
Priority date: 2021-04-26
Filing date: 2021-04-26
Publication date: 2022-08-12
Anticipated expiration: 2041-04-26
Also published as: CN113179711A

Abstract

The invention discloses a ditching, seed pressing and earthing device for a positive-pressure seeder, which comprises a machine base, wherein the machine base is provided with a ditching device, a seed feeding pipe, a seed pressing device and an earthing and pressing device; the ditching device is used for digging a seed groove in the soil; the seed throwing pipe is used for throwing seeds into the seed groove; the seed pressing device comprises a seed pressing wheel, and the seed pressing wheel is used for pressing the seeds thrown into the seed groove by the seed throwing pipe; the earthing device is used for earthing and burying the seed groove. According to the ditching, seed pressing and earthing device for the positive pressure seeder, the seeds thrown by the seed throwing pipe are pressed in time by the seed pressing wheel, so that the seeds can be prevented from bouncing, the planting distance can be ensured, and the seeding quality is improved.

Description

Positive pressure seeder is with ditching earthing device of pressing kind

Technical Field

The invention relates to the technical field of agricultural machinery, in particular to a ditching, seed pressing and soil covering device for a positive pressure seeder.

Background

In the agricultural seeding operation, in order to guarantee the seeding plant spacing of seed, need the input interval of controlling the seed comparatively accurately on the one hand, on the other hand needs the spring of control seed, among the prior art, can realize the equidistant input of seed through the precision seeding seed metering ware, but the seed is put in to the soil after, and the spring that the seed produced is difficult to avoid, because the irregularity of seed spring for the planting quality of seed receives great influence.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects in the prior art and ensure the sowing row spacing of seeds, the invention provides the ditching, seed pressing and soil covering device for the positive pressure sowing machine, which can effectively control the bounce of the seeds.

The technical scheme is as follows: in order to achieve the purpose, the ditching, seed pressing and soil covering device for the positive pressure seeder comprises a base, wherein the base is provided with:

a ditching device for opening a seed trough in the ground;

a seed feeding pipe for feeding seeds into the seed tank;

the seed pressing device comprises a seed pressing wheel, and the seed pressing wheel is used for pressing the seeds thrown into the seed groove by the seed throwing pipe; the hub part and the outer wheel ring of the seed pressing wheel are both flexible; and

and the soil covering device is used for covering soil and burying the seed grooves.

Further, the hub part of the seed pressing wheel is provided with a hollow hole.

Further, the seed throwing pipe is provided with a vertical extending section and an inclined extending section, and the inclined extending section is inclined backwards.

Further, the ditching device comprises two symmetrically-arranged disk openers, and the seed feeding pipe of the seed feeding pipe is provided with a part arranged between the two disk openers.

Further, the ditching device also comprises a depth wheel; the depth wheels are arranged on two sides of the base respectively.

Further, the ditching device also comprises a first mud scraping blade acting on the periphery of the depth wheel.

Further, the earthing device includes the earthing wheel of two symmetries settings, two the earthing wheel is the slope setting, sees on the front and back direction, two the earthing wheel is the layout of V font.

Further, the soil covering device also comprises a second mud scraping blade acting on the periphery of the soil covering wheel.

Has the advantages that: according to the ditching, seed pressing and earthing device for the positive pressure seeder, the seeds thrown by the seed throwing pipe are pressed in time by the seed pressing wheel, so that the seeds can be prevented from bouncing, the planting distance can be ensured, and the planting quality is improved.

Drawings

FIG. 1 is an overall structure diagram of a ditching, seed pressing and soil covering device for a positive pressure seeder;

FIG. 2 is a cross-sectional view of the ditching, seed pressing and soil covering device for the positive pressure seeder;

FIG. 3 is a first perspective view of a second adjustment mechanism;

FIG. 4 is a second perspective view of the second adjustment mechanism;

FIG. 5 is a third perspective view of the second adjustment mechanism;

FIG. 6 is an enlarged structural view of portion A of FIG. 1;

FIG. 7 is a view showing the construction of a seed feeding tube and a seed pressing wheel.

In the figure: 1-a machine base; 11-indicating scale; 12-a receiving groove; 2-ditching device; 21-a disc furrow opener; 22-depth wheel; 23-a first wiper blade; 3-seed casting; 31-a vertically extending section; 32-an obliquely extending section; 4-seed pressing device; 41-a seed pressing wheel; 42-wheel seat; 43-tension spring; 5-a soil covering device; 51-a soil covering wheel; 52-second wiper blade; 6-a first adjustment mechanism; 61-a first rotating frame; 611-a strip-shaped groove; 62-adjusting the screw; 63-adjusting the nut seat; 631-a shaft portion; 64-scale; 65-an indicator; 7-a second adjustment mechanism; 71-a second turret; 711-a holding groove; 712-an elongated slot; 713-the blocking portion; 714-an arc-shaped slot; 715-a docking slot; 72-a resilient member; 73-a third turret; 731-first chute; 732-a second runner; 74-a spacing pin; 75-a connecting rod; 76-a locking screw; 77-rotating the handle; 10-speed detection sensor; 20-electric push rod.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

The ditching, seed pressing and soil covering device for the positive pressure seeder shown in the attached drawings 1 and 2 comprises a base 1, wherein the base 1 is provided with a ditching device 2, a seed feeding pipe 3, a seed pressing device 4 and a soil covering device 5. Wherein, the ditching device 2 is used for digging a seed groove in the soil; the seed feeding pipe 3 is used for feeding seeds into the seed groove; the seed pressing device 4 comprises a seed pressing wheel 41, and the seed pressing wheel 41 is used for pressing the seeds thrown into the seed groove by the seed throwing pipe 3; the soil covering device 5 is used for covering soil and burying the seed grooves.

The respective components will be described in detail below.

Above-mentioned seed wheel 41 is the flexbile wheel, its wheel hub portion all has the flexibility with outer wheel circle part, so, when seed wheel 41 contacts with ground, through the deformation of self, the area of contact on outer wheel circle and ground is big, the regional grow that the seed wheel 41 pressed has been pressed to one side, the drop point of the seed of throwing the kind pipe 3 and throwing has certain deviation also can be pushed down, on the other hand, because seed wheel 41's flexibility is pressed, can make its pressure to ground comparatively suitable, can not crush the seed, the third aspect, the area of contact on outer wheel circle and ground can increase the friction greatly, press kind of in-process can not skid and lead to seed position to change.

Preferably, in order to make the seed pressing wheel 41 more flexible, the hub portion thereof has a hollow hole, and in order to save the manufacturing cost, the hub portion and the outer rim portion thereof are integrally formed, and the whole is made of the same flexible material.

The seed feeding pipe 3 is provided with a vertical extension section 31 and an inclined extension section 32, and the inclined extension section 32 inclines backwards; in this way, the seed dropping direction in the seed feeding tube 3 can be directed to the front side of the ground contact area of the seed pressing wheel 41. Preferably, the intersection point of the extension direction of the inclined extension section 32 and the ground is located in front of the front end point of the contact area when viewed in the axial direction of the seed pressing wheel 41, so that the seeds thrown by the seed throwing pipe 3 can be prevented from hitting the seed pressing wheel 41 and causing more disordered bouncing.

The seed pressing wheel 41 is arranged on the machine base 1 through a wheel seat 42; the wheel seat 42 is rotatably installed relative to the machine base 1, a tension spring 43 is arranged between the wheel seat 42 and the machine base 1, the tension spring 43 can enable the seed pressing wheel 41 to be always in contact with the bottom of the groove and not to be separated from the ground, and in addition, seed pressing force can be provided, and the seed pressing effect is ensured.

In addition, if the seed freely falls kind in seed throwing pipe 3, the seed falls kind in-process can frequently collide with the inner wall of seed throwing pipe 3, the direction that leads to the seed when throwing out is unset, can influence the point of fall of seed like this, lead to pressing wheel 41 probably not to press the seed, in order to solve above-mentioned problem, intraductal the leading-in has high velocity air when seed throwing pipe 3 falls kind, the air current plays acceleration effect to the seed, and make the direction of motion of seed and the extending direction of seed throwing pipe 3 keep unanimous basically, can reduce the collision of seed and inside pipe wall by a wide margin, so final seed is fixed when shooting out from the lower extreme of seed throwing pipe 3 its motion orbit comparison, and the point of falling kind is also comparatively unanimous, can guarantee the quality of seeding.

The ditching device 2 comprises two disc openers 21 which are symmetrically arranged, and the seed feeding pipe 3 of the seed feeding pipe 3 is provided with a part which is arranged between the two disc openers 21. Preferably, in the overlooking direction, the rearmost end of the seed feeding pipe 3 is in front of the rearmost end of the disc opener 21, so that the seed outlet of the seed feeding pipe 3 is also in the real-time ditching range of the disc opener 21, the seed fed out can be ensured to effectively fall into the bottom of the seed groove, and the situation that the seed groove is collapsed to cause that the seed feeding is not in place can not occur.

In order to ensure the consistency of the depth of the ditches dug by the disc ditcher 21, the ditching device 2 also comprises a depth limiting wheel 22; the number of the depth wheels 22 is two, and the two depth wheels 22 are respectively arranged on two sides of the machine base 1. The wheel width of the depth wheel 22 is large, and under the same condition, the depth of the depth wheel 22 which can penetrate into the soil is far less than that of the disc furrow opener 21, so that the depth wheel 22 can effectively limit the furrowing depth of the disc furrow opener 21, and along with the fluctuation of the ground, the depth of the groove formed by the disc furrow opener 21 is consistent.

In addition, ditching device 2 still including acting on depth wheel 22 is first mud scraper 23 all around, and first mud scraper 23 can prevent that depth wheel 22 outer wheel face from wrapping up in earth for effective wheel footpath increase leads to the ditch groove degree of depth that disc furrow opener 21 opened to diminish.

In order to ensure that the seeds can be pressed by the seed pressing wheel 41 just after landing, the relationship between the seed landing point and the seed speed thrown by the seed throwing pipe 3 is calculated according to the following formula:

;

wherein: x-target displacement of the seed in the horizontal direction; y-the height above the ground of the center of the tail end of the seed throwing pipe 3; v-actual detachment speed of the seeds when the seeds are detached from the tail end of the seed throwing pipe 3; v. of ₀ -the running speed of the stand 1; beta-the target projection angle when the seeds are separated from the seed-casting tube 3; g-acceleration of gravity. The intuitive meanings of the above parameters are shown in FIG. 7.

According to the above formula, the speed v and the projection angle β when the seed leaves the end of the seed-feeding tube 3 directly affect the horizontal displacement x of the seed, so that the drop point of the seed can be controlled by controlling the speed v or the projection angle β when the seed leaves the end of the seed-feeding tube 3, and the drop point is more reasonable. Based on this, in a preferred embodiment, as shown in fig. 7, a speed detection sensor 10 may be provided at the end of the seed feeding tube 3, and a controller may be provided, by which the dropping point of the seed is controlled in the following two ways.

The method comprises the following steps: step one, calculating the target speed of the seed according to a preset target displacement (namely the target value of x in the formula) and the formula; and step two, acquiring the actual separation speed of the seeds in real time through the speed detection sensor 10, and adjusting the airflow speed passing through the seed throwing pipe 3, so that the difference between the actual separation speed of the subsequent seeds and the target speed does not exceed a preset range.

The second method comprises the following steps: the inclined extension section 32 is a hard pipe, the other parts are hoses, the electric push rod 20 is additionally arranged to adjust the inclined angle (namely, the projection angle beta can be adjusted) of the inclined extension section 32 of the seed casting pipe 3, the rotating shaft position of the inclined extension section 32 is the tail end of the seed casting pipe 3, so that the numerical value of y in the formula can be kept unchanged, the electric push rod 20 is connected with a controller, and the controller adjusts the falling point of the seeds based on the following process: step one, acquiring the actual separation speed of the seeds in real time through a speed detection sensor 10; substituting the actual separation speed and the target displacement into the formula to calculate a target projection angle; step three, controlling the electric push rod 20 to operate according to the target projection angle, so that the inclination angle of the inclined extension section 32 is equal to the target projection angle; the second step and the third step are operated circularly, so that the controller can adjust the projection angle of the seeds in real time according to the actual speed of the seeds when the seeds are separated from the tail end of the seed-throwing tube 3, the consistency of the falling points of the seeds is ensured, and the seeds can be pressed by the seed-pressing wheel 41 after a very small time interval when just falling to the ground.

The soil covering device 5 comprises two soil covering wheels 51 which are symmetrically arranged, the two soil covering wheels 51 are obliquely arranged, and the two soil covering wheels 51 are arranged in a V shape when seen from the front and the back. The soil covering device 5 further comprises a second mud scraping sheet 52 acting on the periphery of the soil covering wheel 51, and the second mud scraping sheet 52 can timely scrape soil wrapped on the periphery of the soil covering wheel 51 so as to guarantee the soil covering effect.

Preferably, in order to make the ditching and seed pressing earthing device of the present application be used for sowing different seeds, the ditching depth of the ditching device 2 and the soil covering amount of the earthing device 5 per unit time are required, therefore, the ditching and seed pressing earthing device of the present application further comprises a first adjusting mechanism 6 and a second adjusting mechanism 7, the depth wheel 22 is installed on the frame 1 through the first adjusting mechanism 6, and the earthing device 5 is installed on the frame 1 through the second adjusting mechanism 7.

The first adjustment mechanism 6 includes a first rotating frame 61; the first rotating frame 61 is rotatably connected with respect to the base 1, and the relative angle between the first rotating frame and the base can be controllably adjusted.

As shown in fig. 3, the second adjusting mechanism 7 includes a second rotating frame 71; the second rotating frame 71 is rotatably connected with respect to the base 1, and an elastic member 72 is disposed therebetween, and the amount of pretension of the elastic member 72 can be adjusted. In this embodiment, the elastic member 72 is a spring, and the elastic member 72 can ensure that the soil covering device 5 is sufficiently contacted with the ground, and the soil covering device 5 cannot be separated from the ground along with the bumping movement of the machine base 1 in the field; on the other hand, by adjusting the amount of pretension of the elastic member 72, the relative angle between the second rotating frame 71 and the frame 1 is different in actual operation, so that the soil covering amount per unit time of the soil covering device 5 can be adjusted to change the soil covering performance of the soil covering device 5. The larger the pretensioning amount of the elastic member 72 is, the larger the initial effective stiffness of the elastic member 72 is, the more difficult the deformation thereof is, the larger the rotation difficulty of the second rotating frame 71 relative to the machine base 1 is, the deeper the acting depth of the soil covering device 5 in the field is, and the larger the soil covering amount per unit time is, and conversely, the smaller the pretensioning amount of the elastic member 72 is, the shallower the acting depth of the soil covering device 5 is, and the smaller the soil covering amount per unit time is.

Specifically, as shown in fig. 3, a rotating handle 77 is installed on the second rotating frame 71, and both ends of the elastic member 72 are respectively connected to the base 1 and the rotating handle 77; the second rotating frame 71 is provided with a plurality of holding grooves 711 for the stop of the rotating handle 77; the relative angles of the rotating handle 77 and the second rotating frame 71 are different when the rotating handle is stopped in different holding grooves 711. With the above-described structure, when the handle 77 is stopped in the different holding grooves 711, the amount of pretension of the elastic member 72 is different, and thus the initial stiffness of the spring is different. The handle 77 is stopped in the different holding grooves 711, which corresponds to the different shift positions, as shown in fig. 3, there are 5 holding grooves 711, and there are 5 shift positions.

In order to facilitate the movement of the operating handle 77 and switch the operating handle to different shift positions, the second rotating frame 71 is formed with a long groove 712 for the inner movement of the operating handle 72, and all the retaining grooves 711 are alternately arranged on both sides of the long groove 712, that is: if the two sides of the long groove 712 are referred to as the first side and the second side, two adjacent holding grooves 711 are provided, one holding groove 711 is disposed on the first side of the long groove 712, and the other holding groove 711 is disposed on the second side of the long groove 712, so that the arrangement compactness of the holding grooves 711 can be ensured, and the arrangement distance of the holding grooves 711 is not limited by the width of the rotating handle 77. When the shift position is switched, the operating handle 77 is moved out of the holding groove 711 where it is currently located, the operating handle 77 is moved along the long groove 712 to the position of the target holding groove 711, and finally the operating handle 77 is stopped at the target holding groove 711.

The end of the holding groove 711 close to the housing 1 is provided with a stopper 713, and since the rotating handle 77 is pulled by the elastic member 72, it is directly against the end of the elastic member 72 close to the housing 1, so that the stopper 713 prevents the rotating handle 77 from coming out of the holding groove 711.

Since the relative angle between the second rotating frame 71 and the machine base 1 is different when the rotating handle 77 is at different gear positions and during actual operation, in order to avoid the influence of the relative angle between the two on the soil covering effect of the soil covering device 5, preferably, the second adjusting mechanism 7 further comprises a third rotating frame 73, and the soil covering device 5 is mounted on the third rotating frame 73; the third rotating frame 73 is rotatably mounted on the second rotating frame 71, and the relative angle between the third rotating frame and the second rotating frame can be reliably adjusted.

Specifically, as shown in fig. 4 and 5, the third rotating frame 73 is provided with a limiting pin 74, the second rotating frame 71 is provided with an arc-shaped groove 714, a side edge of the arc-shaped groove 714 is provided with a plurality of stopping grooves 715, the number of the stopping grooves 715 is equal to the number of the holding grooves 711, and each holding groove 711 corresponds to each gear of the rotating handle 77; when the limit pin 74 is inserted into different stop grooves 715, the relative angles between the second rotating frame 71 and the third rotating frame 73 are different. A connecting rod 75 is arranged on the third rotating frame 73; the limit pin 74 is fixed at one end of the connecting rod 75, and a locking screw 76 is arranged at the other end of the connecting rod 75; the third rotating frame 73 has a first slide groove 731 and a second slide groove 732, in which the stopper pin 74 and the locking screw 76 slide, respectively.

Through the structure, when the rotating handle 77 is switched to different gears, the limiting pin 74 is correspondingly embedded into the corresponding retaining groove 711, so that the orientation of the soil covering device 5 is correct during operation, and the soil covering effect is ensured. When the angle of the third rotating frame 73 needs to be adjusted, the locking screw 76 is firstly unscrewed; then, the connecting rod 75 is integrally translated relative to the third rotating frame 73, and at this time, the locking screw 76 and the limiting pin 74 respectively slide in the first sliding groove 731 and the second sliding groove 732; then, the third rotating frame 73 is pulled to rotate relative to the second rotating frame 71, so that the limit pin 74 reaches the position of the target holding groove 711, and at the moment, the limit pin 74 moves in the arc-shaped groove 714; finally, the link 75 is integrally translated with respect to the third rotating frame 73 to fit the stopper pin 74 into the target holding groove 711, and the lock screw 76 is tightened.

As shown in fig. 1 and fig. 2, the first adjusting mechanism 6 further includes an adjusting screw 62 rotatably mounted with respect to the housing 1, and an adjusting nut seat 63 used in cooperation with the adjusting screw 62; the adjustment nut holder 63 includes a shaft portion 631, and the first rotating frame 61 includes a strip groove 611 in which the shaft portion 631 moves. With the structure, the first rotating frame 61 can be driven to rotate relative to the machine base 1 through the adjusting screw rod 62 so as to adjust the height position of the depth wheel 22, and thus the depth of the groove formed by the ditching device can be limited. A rotating handle is fixed to the adjusting screw 62 for convenient operation.

In order to facilitate the user to adjust the height position of the depth wheel 22, the first adjusting mechanism 6 further includes a scale 64 extending along the axial direction of the adjusting screw 62, one end of the scale is connected to the adjusting nut seat 63, the other end of the scale is provided with an indicating member 65, the machine base 1 is provided with an indicating scale 11, and the indicating member 65 can move along the indicating scale 11 due to the movement of the adjusting nut seat 63. In this embodiment, as shown in fig. 6, the indicating member 65 is a pin, the housing 1 is formed with an accommodating groove 12, the pin can slide in the accommodating groove 12, and the indicating scale 11 is a plurality of pointed concave portions formed on one side of the accommodating groove 12. In this way, when the user rotates the adjusting screw 62, the height position of the depth wheel 22 can be known according to the scale position of the indicating member 65, and the adjustment is more accurate without relying on experience or trial and error.

According to the ditching, seed pressing and earthing device for the positive pressure seeder, the seeds thrown by the seed throwing pipe are pressed in time by the seed pressing wheel, so that the seeds can be prevented from bouncing, the planting distance can be ensured, and the planting quality is improved.

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention, and such modifications and adaptations are intended to be within the scope of the invention.

Claims

1. The utility model provides a malleation is ditching for seeder presses kind earthing device, its characterized in that, it includes frame (1), install on frame (1):

a ditching device (2) for opening a seed trough in the ground;

a seed feeding pipe (3) for feeding seeds into the seed groove, wherein the seed feeding pipe (3) feeds air flow into the pipe while dropping the seeds;

the seed pressing device (4) comprises a seed pressing wheel (41), and the seed pressing wheel (41) is used for pressing the seeds thrown into the seed groove by the seed throwing pipe (3); the soil covering device (5) is used for covering soil and burying the seed grooves;

the pressure wheel (41) is a flexible wheel, and a hub part and an outer wheel ring part of the pressure wheel are flexible;

the soil covering device (5) is arranged on the base (1) through a second adjusting mechanism (7); the second adjusting mechanism (7) comprises a second rotating frame (71) and a third rotating frame (73); the third rotating frame (73) is rotatably arranged on the second rotating frame (71), and the soil covering device (5) is arranged on the third rotating frame (73); the second rotating frame (71) is rotatably connected relative to the base (1), an elastic piece (72) is arranged between the second rotating frame and the base, and the pretension amount of the elastic piece (72) can be adjusted;

the method is characterized in that:

the hub part and the outer wheel ring part are integrally formed, and the whole seed pressing wheel (41) is made of the same flexible material;

a limiting pin (74) is mounted on the third rotating frame (73), an arc-shaped groove (714) is formed in the second rotating frame (71), and a plurality of stopping grooves (715) are formed in the side edge of the arc-shaped groove (714); when the limiting pin (74) is embedded into different parking grooves (715), the relative angles between the second rotating frame (71) and the third rotating frame (73) are different;

a connecting rod (75) is arranged on the third rotating frame (73); the limiting pin (74) is fixed at one end of the connecting rod (75), and a locking screw (76) is arranged at the other end of the connecting rod (75); a first sliding groove (731) and a second sliding groove (732) which are respectively used for the limiting pin (74) and the locking screw (76) to slide inwards are formed on the third rotating frame (73); the seed feeding pipe (3) is provided with a vertical extending section (31) and an inclined extending section (32), and the inclined extending section (32) inclines backwards; the inclined extension section (32) is set as a hard tube, an electric push rod (20) is additionally arranged to adjust the inclination angle of the inclined extension section (32), the rotating shaft position of the inclined extension section (32) is the tail end of the seed throwing tube (3), the electric push rod (20) is connected with a controller, and the controller adjusts the falling point of the seeds based on the following procedures: step one, acquiring the actual separation speed of the seeds in real time through a speed detection sensor (10); substituting the actual separation speed and the target displacement into the following formula to calculate a target projection angle;

；

wherein: x-target displacement of the seed in the horizontal direction; y is the ground clearance of the center of the tail end of the seed throwing pipe (3); v-actual speed of seed detachment from the end of seed feeding pipe (3); v. of ₀ -the running speed of the stand (1); beta-a target projection angle when the seeds are separated from the seed-casting tube (3); g-acceleration of gravity; and step three, controlling the electric push rod (20) to operate according to the target projection angle, so that the inclination angle of the inclined extension section (32) is equal to the target projection angle.

2. The ditching, seed pressing and soil covering device for the positive pressure seeder according to claim 1, wherein the hub portion of the seed pressing wheel (41) has a hollowed-out hole.

3. The ditching, seed-pressing and covering device for the positive pressure seeder according to claim 1, wherein the ditching device (2) comprises two symmetrically arranged disc openers (21), and the seed feeding pipe (3) has a portion disposed between the two disc openers (21).

4. The ditching, seed-pressing and covering device for the positive pressure seeder according to claim 3, wherein the ditching device (2) further comprises a depth-limiting wheel (22); the number of the depth wheels (22) is two, and the two depth wheels (22) are respectively arranged on two sides of the machine base (1).

5. The ditching, seed pressing and soil covering device for the positive pressure seeder according to claim 4, wherein the ditching device (2) further comprises a first mud scraper (23) acting on the periphery of the depth wheel (22).

6. The ditching, seed-pressing and soil-covering device for the positive pressure seeder according to claim 1, wherein the soil-covering device (5) comprises two symmetrically arranged soil-covering wheels (51), both soil-covering wheels (51) are obliquely arranged, and the two soil-covering wheels (51) are arranged in a V-shape as viewed in the front-rear direction.

7. The ditching, seed-pressing and soil-covering device for the positive pressure seeder as claimed in claim 6, wherein the soil-covering device (5) further comprises a second scraper blade (52) acting on the periphery of the soil-covering wheel (51).