CN217407026U

CN217407026U - Combined drill seeder

Info

Publication number: CN217407026U
Application number: CN202221267330.3U
Authority: CN
Inventors: 郏孟安; 董兵; 李海星; 汪艳政; 闫照鑫
Original assignee: Weichai Lovol Heavy Industry Co Ltd
Current assignee: Weichai Lovol Intelligent Agricultural Technology Co Ltd
Priority date: 2022-05-24
Filing date: 2022-05-24
Publication date: 2022-09-13
Anticipated expiration: 2032-05-24

Abstract

The utility model relates to a combined type drill seeder relates to agricultural machine field, include by preceding power harrow mechanism and the drill seeding mechanism that sets gradually after to, the seed metering shell cover of seed metering ware is in the outside of seed metering nail wheel subassembly, and the seed metering shell has seed entry and seed export, and the seed metering shell of seed entrance is equipped with portable or the picture peg that rotates and fix a position, and the seed metering shell of seed exit is equipped with portable or the seed metering spoon that rotates and fix a position. The beneficial effects are that: the combined drill seeder carries out a combined operation mode by connecting the power harrow with the drill seeder, improves the working efficiency and reduces the operation cost. The seed metering device flashboard controls the size of the seed inlet opening, the seed metering spoon controls the size of the seed outlet opening, and the seed metering nail wheel component rotates in the circumferential direction to realize seed metering. According to the sizes, the shapes and the seeding quantity of different seeds, one or more of the sizes of the seed inlets, the sizes of the seed outlets and the rotating speed of the seed metering nail wheel assembly are adjusted, so that different seeds are sown.

Description

Combined drill seeder

Technical Field

The utility model relates to the field of agricultural machinery, concretely relates to combined type drill seeder.

Background

At present, wheat in the central plain region needs to be sown after rotary tillage, the number of times of sowing is large, and the time and operation cost are high.

The rotary cultivator has low working efficiency, and the working efficiency is usually 5-6 km/h. The seeder has single operation variety, the seeding quantity, the seeding speed and the size of the seed discharging port are difficult to adjust, and only one crop can be sown. The seeding rate is difficult to be uniformly adjusted, and the operation effect is poor.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the utility model is how to simplify the seeding operation steps and adapt to the seeding of various crops.

The utility model provides an above-mentioned technical problem's technical scheme as follows: a composite drill seeder, which comprises a power harrow mechanism and a drill seeding mechanism which are arranged from front to back in sequence,

the drilling sowing mechanism comprises a seed sowing device, the seed sowing device comprises a seed sowing shell and a seed sowing nail wheel assembly, the seed sowing shell covers the outside of the seed sowing nail wheel assembly, the seed sowing shell is provided with a seed inlet and a seed outlet, the seed sowing shell is provided with a movable or rotatable and positioned inserting plate at the seed inlet, the seed outlet is provided with a movable or rotatable and positioned seed sowing spoon.

The utility model has the advantages that: the combined drill seeder carries out a combined operation mode by connecting the power harrow with the drill seeder, improves the working efficiency and reduces the operation cost. The rotary tillage and then the seeding can be carried out under the traditional working condition, and the seeding operation can also be directly carried out by plowing and turning the soil. The power harrow and the drill seeder are operated in a combined way, and the operation speed of the power harrow can reach 8-10 km/h.

The seed metering device flashboard controls the size of the opening of the seed inlet, the seed metering spoon controls the size of the opening of the seed outlet, and the seed metering nail wheel component rotates in the circumferential direction to drive seeds to move, so that the seeds are brought from the seed inlet to the seed outlet to be uniformly discharged, and the seed metering is realized. According to the sizes, the shapes and the seeding quantity of different seeds, one or more of the sizes of the seed inlets, the sizes of the seed outlets and the rotating speed of the seed metering nail wheel assembly are adjusted, so that different seeds are sown.

On the basis of the technical scheme, the utility model discloses can also do following improvement.

Further, the seed metering ware still includes spring and guide, the picture peg with seed metering shell sliding connection, have on the picture peg along the bar guide way and a plurality of that the slip direction set up with the spacing groove of bar guide way intercommunication, the one end of guide with seed metering shell fixed connection, the other end passes in proper order the spring with the bar guide way, the one end of spring with the one end butt or the fixed connection of guide, the other end can slide and block into one of them in the bar guide way the spacing groove.

The beneficial effect of adopting the further scheme is that: when the plug board needs to be adjusted, the manual compression spring or the end part of the spring is provided with the truncated cone-shaped gasket, and when the plug board moves, the spring is guided by the truncated cone-shaped gasket to compress and move out of the limiting groove. Then, the insert plate moves under the guide action of the guide member and the strip-shaped guide groove, thereby adjusting the size of the seed inlet opening. When the spring is adjusted in place, the spring extends under the action of elastic force and is clamped into the corresponding limiting groove.

Further, the seed outlet is located the downside of seed metering shell, the one end of seed metering spoon with seed metering shell rotates to be connected and the location, the other end extend to in the seed outlet.

The beneficial effect of adopting the further scheme is that: the seed-metering spoon rotates to adjust the size of the opening of the seed outlet.

Furthermore, the drill seeding mechanism also comprises a seed shaft and a stepless speed change component, the seed screw wheel component of the seed sowing device is fixed on the seed shaft, and the stepless speed change component is in transmission connection with the seed shaft.

The beneficial effect of adopting the further scheme is that: the stepless speed change assembly can uniformly adjust the rotating speed of the seeding shaft and realize the stepless regulation of the seeding quantity.

Further, the drill seeding mechanism comprises at least two seed metering devices which are arranged at intervals along the axial direction of the seed metering shaft.

Further, drill seeding mechanism still includes the variable speed shell, infinitely variable subassembly is including installing one-way bearing, pendulum rod, power input cam, slide rail and the piece that resets in the variable speed shell, one-way bearing has inner circle and the outer lane that can one-way transmission, the inner circle with seed metering axle fixed connection, the one end of pendulum rod with the outer lane is articulated, and the other end is followed the slide rail slides, the slide rail can move or rotate and with variable speed shell location connects, the middle part of pendulum rod with the piece that resets is connected, power input cam with the middle part butt of pendulum rod.

The beneficial effect of adopting the further scheme is that: a power mechanism of the combined drill seeder drives a power input cam to rotate circumferentially, a swing rod moves downwards under the compression action of the power input cam, the other end of the swing rod slides along the slide rail, and one end of the swing rod drives a one-way bearing to rotate for a certain angle and drives a seeding shaft to rotate. Then the swing rod is reset under the action of the reset piece, and the one-way bearing does not drive the seeding shaft to rotate in the reset process. The amount of exercise of the one-way bearing driven by the oscillating bar is influenced by the track of the slide rail every time, when the slide rail is rotated to change the angle of the slide rail, the transmission ratio is changed, and the angle of the slide rail can be changed at will by the handle arranged on the outer side of the slide rail, so that the stepless regulation of the seeding amount is realized. The seeding quantity adjusting range is large, various operations such as seeding wheat, barley, oat, alfalfa, rape, rice and the like can be realized, and one machine can realize multicast.

Furthermore, the two groups of continuously variable transmission assemblies are coaxially arranged, and power input cams of the two groups of continuously variable transmission assemblies have phase differences.

The beneficial effect of adopting the further scheme is that: the two power input cams alternately press the corresponding swing rods, and the swing rods sequentially drive the corresponding one-way bearings to rotate, so that the one-way bearings move uninterruptedly to perform transmission output.

Further, the power harrow mechanism includes at least one power harrow knife tackle, every power harrow knife tackle includes harrow arbor and harrow sword, the harrow arbor is vertical to be set up and can rotate around self axis, the harrow sword is a plurality of, a plurality of the harrow sword is in the circumference interval setting of harrow arbor.

The beneficial effect of adopting the further scheme is that: usually, the shaft of the rotary blade is horizontally arranged, and the rotary blade rotates around the shaft, so that the rotary blade sequentially cuts into soil from the top to the bottom and throws the soil in the top to back direction. The working principle of the power harrow cutter set is that a harrow cutter shaft rotates along the direction of a ground vertical line, so that the harrow cutter cuts soil in the left-right direction and throws the soil backwards. The rotary cultivator has large vibration when working, and the normal operation speed is 5-6 km/h. The power harrow has small vibration and the operation speed can reach 8-10 km/h.

Further, power harrow mechanism still includes flat native thick stick and compression roller, power harrow knife tackle flat native thick stick with the compression roller sets gradually by preceding to back.

The beneficial effect of adopting the further scheme is that: the power harrow cutter set rotates under the drive of the PTO shaft of the tractor to smash soil and carry out soil preparation operation, the soil leveling bar is used for leveling the smashed soil, and the pressing roller is used for compacting the leveled soil to form a good seedbed.

Further, the drill seeding mechanism also comprises a seeding press wheel arranged at the rear part of the seed sowing device.

The beneficial effect of adopting the further scheme is that: the drilling and seeding mechanism is connected with the rear part of the power harrow mechanism in a hanging way, the seed sowing device of the seeding unit ditches on the seed bed and performs seeding, and the seeding press wheel at the rear part presses after seeding to complete the seeding operation.

Drawings

FIG. 1 is a schematic view of the composite drill of the present invention;

FIG. 2 is a cross-sectional view of the seed metering device of the present invention;

FIG. 3 is an enlarged view of a portion of the seed meter of FIG. 2 at A;

FIG. 4 is a bottom view of the seed meter of FIG. 2;

FIG. 5 is a structural diagram of the continuously variable transmission assembly of the present invention;

fig. 6 is a schematic structural view of the power rake blade set of the present invention, and the two-dot chain line in the figure indicates the ground.

In the drawings, the components represented by the respective reference numerals are listed below:

1. a power rake mechanism; 2. a drill seeding mechanism; 3. a seed shaft; 4. a seed metering housing; 401. a seed inlet; 402. a seed outlet; 5. inserting plates; 501. a strip-shaped guide groove; 502. a limiting groove; 6. a seed discharging spoon; 7. a spring; 8. a guide member; 9. a one-way bearing; 10. a swing rod; 11. a power input cam; 12. a slide rail; 13. a reset member; 14. raking the cutter shaft; 15. raking a cutter; 16. leveling the soil; 17. a press roller; 18. a sowing press wheel; 19. a power harrow cutter group; 20. sowing the single seeds; 21. a seed-sowing nail wheel component.

Detailed Description

The principles and features of the present invention are described below in conjunction with the following drawings, the examples given are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

As shown in fig. 1 to 5, the present embodiment provides a composite seed drill, which comprises a power rake mechanism 1 and a seed drill mechanism 2 arranged in sequence from front to back,

the drilling sowing mechanism 2 comprises a seed sowing device, the seed sowing device comprises a seed sowing shell 4 and a seed sowing nail wheel component 21, the seed sowing shell 4 covers the outside of the seed sowing nail wheel component 21, the seed sowing shell 4 is provided with a seed inlet 401 and a seed outlet 402, the seed inlet 401 is provided with a movable or rotatable and positioned inserting plate 5 of the seed sowing shell 4, the seed outlet 402 is provided with a movable or rotatable and positioned seed sowing spoon 6 of the seed sowing shell 4.

The combined drill seeder is connected with the power harrow and the drill seeder to carry out combined operation, thereby improving the working efficiency and reducing the operation cost. The rotary tillage and then the seeding can be carried out under the traditional working condition, and the seeding operation can also be directly carried out by plowing and turning the soil. The power harrow and the drill seeder are operated in a combined way, and the operation speed of the power harrow can reach 8-10 km/h.

The seed metering device flashboard 5 controls the opening size of the seed inlet 401, the seed metering scoop 6 controls the opening size of the seed outlet 402, and the seed metering nail wheel component 21 rotates in the circumferential direction to drive the seeds to move, so that the seeds are brought from the seed inlet 401 to the seed outlet 402 to be uniformly discharged, and the seed metering is realized. One or more of the size of the seed inlet 401, the size of the seed outlet 402 and the rotating speed of the seed sowing nail wheel assembly 21 are adjusted according to the size, the shape and the sowing quantity of different seeds, so that different seeds are sowed.

Specifically, the combined seed drill further comprises a frame, and the seed discharging shell 4 is fixed on the frame.

Specifically, as shown in fig. 4, the seed sowing nail wheel assembly 21 includes a big nail wheel and a small nail wheel which are arranged side by side on a rotation axis thereof, and the big nail wheel and the small nail wheel are respectively provided with nail teeth with different sizes and intervals.

On the basis of the scheme, the inserting plate 5 and the seed discharging shell 4 can be connected by adopting any adjustable structure. In a specific embodiment, the seed metering ware still includes spring 7 and guide 8, picture peg 5 with seed metering shell 4 sliding connection, the last bar guide way 501 and a plurality of and the spacing groove 502 of bar guide way 501 intercommunication that set up along the slip direction that have of picture peg 5, the one end of guide 8 with seed metering shell 4 fixed connection, the other end passes in proper order spring 7 with bar guide way 501, the one end butt or the fixed connection of spring 7 with the one end butt of guide 8, the other end can slide and block into one of them spacing groove 502 in the bar guide way 501.

When the adjustment is needed, the manual compression spring 7 or the end part of the spring 7 is provided with a circular truncated cone-shaped gasket, and when the inserting plate 5 moves, the spring 7 is guided by the circular truncated cone-shaped gasket to compress and move out of the limiting groove 502. Then, the insert plate 5 is moved by the guide of the guide member 8 and the bar-shaped guide groove 501, thereby adjusting the size of the opening of the seed inlet 401. When the position is adjusted, the spring 7 extends under the action of elastic force and is clamped into the corresponding limit groove 502.

Specifically, as shown in fig. 3 and 4, the strip-shaped guide groove 501 is a through hole penetrating through the board 5, and the limiting groove 502 is a blind hole. The retaining groove 502 may be a circular hole or other geometric shaped hole.

On the basis of the scheme, the seed-metering spoon 6 and the seed-metering shell 4 can be connected by adopting any adjustable structure. In one particular embodiment, the seed outlet 402 is located on the underside of the seed housing 4, and the seed scoop 6 is pivotally connected to and positioned within the seed housing 4 at one end and extends into the seed outlet 402 at the other end.

The seed-metering spoon 6 rotates to adjust the opening size of the seed outlet 402.

The seed-metering spoon 6 is rotatably connected with the seed-metering shell 4, one feasible implementation mode is that a seed-metering spoon mounting shaft is fixed on the seed-metering shell 4, one end of the seed-metering spoon 6 is sleeved on the seed-metering spoon mounting shaft and is pressed tightly through a nut, and when adjustment is needed, the nut can be loosened and the seed-metering spoon 6 can be rotated. Another feasible implementation mode is that a seed discharging spoon mounting shaft is rotatably arranged on the seed discharging shell 4, one end of the seed discharging spoon 6 is fixed on the seed discharging spoon mounting shaft, a clamping part is arranged at the end part of the seed discharging spoon mounting shaft, the seed discharging shell 4 is provided with a plurality of clamping grooves, and the clamping part is detachably clamped with one of the clamping grooves.

On the basis of any one of the above schemes, the drill seeding mechanism 2 further comprises a seeding shaft 3 and a stepless speed change assembly, the seeding nail wheel assembly 21 of each seeding device is fixed on the seeding shaft 3, and the stepless speed change assembly is in transmission connection with the seeding shaft 3.

The stepless speed change assembly can uniformly adjust the rotating speed of the seeding shaft 3 and realize the stepless regulation of the seeding quantity.

Preferably, the drill seeding mechanism 2 comprises at least two seed metering devices, and the at least two seed metering devices are arranged at intervals along the axial direction of the seed metering shaft 3.

On the basis of any scheme, the drilling and seeding mechanism 2 further comprises a variable speed shell, the stepless speed change component comprises a one-way bearing 9, a swing rod 10, a power input cam 11, a slide rail 12 and a reset piece 13 which are arranged in the variable speed shell, the one-way bearing 9 is provided with an inner ring and an outer ring which can be in one-way transmission, the inner ring is fixedly connected with the seed sowing shaft 3, one end of the swing rod 10 is hinged with the outer ring, the other end of the swing rod slides along the slide rail 12, the slide rail 12 can move or rotate and is connected with the variable speed shell in a positioning mode, the middle part of the swing rod 10 is connected with the reset piece 13, and the power input cam 11 is abutted to the middle part of the swing rod 10.

A power mechanism of the composite drill seeder drives a power input cam 11 to rotate circumferentially, a swing rod 10 moves downwards under the compression action of the power input cam 11, the other end of the swing rod 10 slides along the slide rail 12, and one end of the swing rod 10 drives a one-way bearing 9 to rotate for a certain angle and drives the seeding shaft 3 to rotate. Then the swing link 10 is reset under the action of the reset piece 13, and the unidirectional bearing 9 does not drive the seeding shaft 3 to rotate in the resetting process. The amount of movement of the unidirectional bearing 9 driven by the oscillating bar 10 is influenced by the track of the slide rail 12 each time, when the slide rail 12 is rotated to change the angle of the slide rail 12, the transmission ratio is changed, and the angle of the slide rail can be changed at will by the handle arranged on the outer side of the slide rail 12, so that the stepless regulation of the seeding amount is realized. The seeding quantity adjusting range is large, various operations such as seeding wheat, barley, oat, alfalfa, rape, rice and the like can be realized, and one machine can realize multicast.

Wherein, the reset piece 13 can be an elastic component such as a spring or a gas spring, one end of the reset piece 13 is hinged with the middle part of the swing rod 10, and the other end is hinged with the speed change housing.

Preferably, the other end of the swing link 10 is provided with a bearing, so as to reduce the friction force with the slide rail 12.

Wherein the slide rail 12 is rotatably adjustable and positionable to adjust the transmission ratio. Similar to the mounting manner of the seed-metering spoon 6. One of the feasible embodiments is that a slide rail mounting shaft is fixed on the speed change housing, the slide rail 12 is sleeved on the slide rail mounting shaft and is pressed tightly by a nut, and when the adjustment is needed, the nut can be loosened, the slide rail 12 is rotated and then screwed down. Another feasible implementation manner is that a sliding rail mounting shaft is rotatably arranged on the speed change housing, the sliding rail 12 is fixed on the sliding rail mounting shaft, a clamping portion is arranged at the end of the sliding rail mounting shaft, the speed change housing is provided with a plurality of clamping grooves, and the clamping portion is detachably clamped with one of the clamping grooves.

The continuously variable transmission assembly may be provided with one or more sets. In one specific embodiment, the two continuously variable transmission assemblies are arranged in two groups, and the power input cams 11 of the two groups of continuously variable transmission assemblies are coaxially arranged and have a phase difference.

Preferably, the phase difference between the two power input cams 11 is 180 degrees, the two power input cams 11 alternately press the corresponding swing rods 10, and the swing rods 10 sequentially drive the corresponding one-way bearings 9 to rotate, so that the one-way bearings 9 continuously move to perform transmission output.

On the basis of any one of the above schemes, the power rake mechanism 1 includes at least one power rake cutter set 19, each power rake cutter set 19 includes a rake cutter shaft 14 and a rake cutter 15, the rake cutter shaft 14 is vertically arranged and can rotate around its own axis, the rake cutters 15 are multiple, and the multiple rake cutters are arranged at intervals in the circumferential direction of the rake cutter shaft 14.

Usually, the shaft of the rotary blade is horizontally arranged, and the rotary blade rotates around the shaft, so that the rotary blade sequentially cuts into soil from the top to the bottom and throws the soil in the top to back direction. As shown in fig. 6, the power harrow cutter set 19 works in such a manner that the harrow cutter shaft 14 rotates in the direction of the vertical line of the ground, so that the harrow cutters 15 cut soil in the left-right direction and throw the soil backward. The rotary cultivator has large vibration when working, and the normal operation speed is 5-6 km/h. The power harrow has small vibration and the operation speed can reach 8-10 km/h.

On the basis of any one of the above schemes, the power harrow mechanism 1 still includes flat earth thick stick 16 and press roll 17, power harrow knife tackle 19 flat earth thick stick 16 with press roll 17 sets gradually from the front to the back.

The power harrow cutter group 19 rotates under the drive of the PTO shaft of the tractor to smash soil and carry out soil preparation operation, the soil leveling bar 16 levels the smashed soil, and the press roller 17 compacts the leveled soil to form a good seedbed.

Specifically, the soil leveling bar 16 is fixed on the frame, and the press roller 17 and the power harrow cutter group 19 are both rotatably arranged on the frame.

On the basis of any scheme, the drill seeding mechanism 2 further comprises a seeding press wheel 18 arranged behind the seed sowing device.

The drill seeding mechanism 2 is hung behind the power harrow mechanism 1, the seed sowing device of the seeding single body 20 ditches on the seed bed and performs seeding, and the seeding press wheel 18 at the rear performs seeding and pressing again to complete the seeding operation.

Specifically, the sowing press wheel 18 is rotatably mounted on the frame.

In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "axial", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite drill seeder is characterized in that the composite drill seeder comprises a power harrow mechanism (1) and a drill seeding mechanism (2) which are arranged from front to back in sequence,

drilling sowing mechanism (2) are including the seed metering ware, the seed metering ware includes seed metering shell (4) and seed metering nail wheel subassembly (21), seed metering shell (4) cover the outside of seed metering nail wheel subassembly (21), seed metering shell (4) have seed entry (401) and seed export (402), seed entry (401) department seed metering shell (4) are equipped with picture peg (5) portable or that rotate and fix a position, seed export (402) department seed metering shell (4) are equipped with portable or that rotate and seed metering spoon (6) of fixing a position.

2. The combined seed drill as claimed in claim 1, wherein the seed metering device further comprises a spring (7) and a guide member (8), the inserting plate (5) is slidably connected with the seed metering shell (4), the inserting plate (5) is provided with a strip-shaped guide groove (501) arranged along the sliding direction and a plurality of limiting grooves (502) communicated with the strip-shaped guide groove (501), one end of the guide member (8) is fixedly connected with the seed metering shell (4), the other end of the guide member sequentially passes through the spring (7) and the strip-shaped guide groove (501), one end of the spring (7) is abutted against or fixedly connected with one end of the guide member (8), and the other end of the spring can slide in the strip-shaped guide groove (501) and is clamped into one of the limiting grooves (502).

3. A combined seed drill as claimed in claim 1, characterised in that the seed outlet (402) is located on the underside of the seed housing (4), and the seed scoop (6) is rotatably connected to and positioned at one end with the seed housing (4) and extends with its other end into the seed outlet (402).

4. The combined seed drill according to claim 1, wherein the seed drilling and sowing mechanism (2) further comprises a seed shaft (3) and a stepless speed change assembly, the seed screw wheel assembly (21) of the seed drill is fixed on the seed shaft (3), and the stepless speed change assembly is in transmission connection with the seed shaft (3).

5. A compound seed drill as claimed in claim 4, characterized in that the seed-drilling mechanism (2) comprises at least two seed-metering devices, which are arranged at intervals in the axial direction of the seed-metering shaft (3).

6. The combined seed drill according to claim 4, wherein the seed drill mechanism (2) further comprises a variable speed housing, the continuously variable transmission assembly comprises a one-way bearing (9), a swing link (10), a power input cam (11), a slide rail (12) and a reset member (13) which are arranged in the variable speed housing, the one-way bearing (9) is provided with an inner ring and an outer ring which can be driven in a one-way manner, the inner ring is fixedly connected with the seed shaft (3), one end of the swing link (10) is hinged with the outer ring, the other end of the swing link slides along the slide rail (12), the slide rail (12) can move or rotate and is connected with the variable speed housing in a positioning manner, the middle part of the swing link (10) is connected with the reset member (13), and the power input cam (11) is abutted against the middle part of the swing link (10).

7. A compound seed drill as claimed in claim 6, characterised in that the continuously variable transmission assemblies are in two groups, the power input cams (11) of the two groups being coaxially disposed and having a phase difference.

8. A compound seed drill as claimed in any one of claims 1 to 7, characterised in that the power harrow mechanism (1) comprises at least one power harrow cutter group (19), each power harrow cutter group (19) comprises a harrow cutter shaft (14) and a harrow cutter (15), the harrow cutter shaft (14) is vertically arranged and can rotate around the axis thereof, the harrow cutter (15) is a plurality of harrow cutters, and the harrow cutters are arranged at intervals in the circumferential direction of the harrow cutter shaft (14).

9. The combined seed drill as claimed in claim 8, wherein the power harrow mechanism (1) further comprises a soil leveling bar (16) and a press roller (17), and the power harrow knife set (19), the soil leveling bar (16) and the press roller (17) are sequentially arranged from front to back.

10. A combined seed drill according to any one of claims 1-7, characterised in that the seed drilling and sowing mechanism (2) further comprises a sowing press wheel (18) arranged behind the seed metering device.