Planting mechanism for pot seedlings with adjustable plant spacing and method for adjusting plant spacing

Abstract

This invention discloses an adjustable-spacing potted seedling planting mechanism and its method for adjusting plant spacing. The main shaft and planetary carrier drive shaft are driven by different power sources, and the planting box is fixed to the planetary carrier drive shaft. The sun gear is fitted around the planetary carrier drive shaft and connected to the main shaft via a gear transmission assembly. The intermediate shaft is fixed to the planting box, and the intermediate wheel and intermediate shaft form a revolute joint. The planetary gears are fixed to the planetary shaft, and the planetary shaft and planting box form a revolute joint, driving the planting nozzle assembly to rotate. The intermediate wheel meshes with both the sun gear and the planetary gears. Changing the plant spacing or horizontal operating speed calls the corresponding target angular displacement mapping relationship between the sun gear and the planting box, altering the input-coordinated speed change motion relationship, resulting in changes to the output motion of the planetary gears and the static trajectory of the planting nozzle. This invention eliminates the need to redesign or replace gears and sprockets for different plant spacing trajectories. Furthermore, the sun gear, intermediate gear, and planetary gears are all round gears, ensuring smooth transmission, high load-bearing capacity, and easy processing.

Description

Technical Field

[0001] This invention belongs to the field of potted seedling transplanting technology, specifically relating to an adjustable potted seedling planting mechanism and its plant spacing adjustment method. Background Technology

[0002] Transplanting seedlings is a crucial step in the production of crops such as vegetables, rice, tobacco, and flowers. The planting mechanism, as a key component of the transplanter, directly affects the uprightness of the planted seedlings, the damage rate, and the stability of the plant spacing due to its movement trajectory, soil insertion posture, and seedling placement position. Plant spacing refers to the distance between two adjacent seedlings planted along the transplanter's operating direction; different crops and agronomic conditions typically have different plant spacing requirements.

[0003] For a periodic motion-type seedling planting mechanism, when only the movement of the planting nozzle assembly relative to the frame is considered, the trajectory formed by the tip of the planting nozzle relative to the frame is a static trajectory. When horizontal relative motion occurs between the frame and the soil, the static trajectory and the horizontal working motion of the frame relative to the soil superimpose to form a dynamic trajectory. The time interval between two adjacent planting events and the horizontal working speed of the frame relative to the soil jointly determine the theoretical plant spacing, while the static trajectory of the planting nozzle affects the soil entry position, seedling placement posture, and exit path of the dynamic trajectory. Therefore, when adjusting the plant spacing, it is also necessary to adjust the static trajectory of the planting nozzle according to the corresponding horizontal working speed and planting cycle to ensure the planting quality under different plant spacing conditions.

[0004] Existing planetary gear planting mechanisms typically employ non-circular gears to create periodically variable transmission ratios, achieving planting trajectories that meet specific agronomical requirements. Once the pitch curve and tooth profile parameters of the non-circular gears are determined, their periodic transmission law and the corresponding static trajectory of the planting nozzle are essentially established. However, when significant changes occur in the horizontal operating speed or plant spacing, the dynamic trajectory formed by the superposition of the original static trajectory and the horizontal operating motion may be insufficient to meet the requirements for the planting nozzle's entry into the soil, seedling placement, and emergence from the soil, often necessitating a redesign or replacement of the non-circular gears. Furthermore, non-circular gears also present challenges such as complex pitch curve design and manufacturing processes, potential root cutting in certain tooth profiles, and limitations on transmission load-bearing capacity due to tooth shape.

[0005] Circular gears offer advantages such as fixed mechanical transmission ratios, ease of manufacturing, high load-bearing capacity, and smooth transmission. However, when using a planetary gear system driven by a constant speed, the motion relationships between its components and the static trajectory of the planting nozzle remain relatively fixed. The key technical challenge in achieving planting at different spacings lies in independently controlling the two power input paths—the sun gear and the planting box—without altering the fixed mechanical transmission ratio of the circular gears or replacing transmission components. This would allow the two to form a coordinated, variable-speed motion relationship that changes with the position of the gear within a planting cycle, thereby altering the output motion of the planetary gears and the trajectory of the planting nozzle tip. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of existing seedling planting mechanisms where the planting trajectory is limited by fixed mechanical transmission laws and the need to redesign or replace transmission components when adjusting the plant spacing by a large margin. The invention provides a potted seedling planting mechanism with adjustable plant spacing and its plant spacing adjustment method. Under the condition that the mechanical transmission ratio of the circular gear remains unchanged, the output motion of the planetary gear and the static trajectory of the tip of the planting nozzle assembly are changed by controlling the coordinated speed change relationship of the two power inputs during the planting cycle, so as to adapt to potted seedling planting operations under different plant spacing conditions.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The present invention discloses an adjustable spacing potted seedling planting mechanism, comprising a frame, a seedling box, a planetary gear seedling planting assembly, a planting nozzle assembly, a transmission box, and a gear transmission assembly.

[0009] The transmission housing is fixed to the frame, and both the drive shaft and the planetary carrier drive shaft are rotatably supported on the transmission housing; the drive shaft and the planetary carrier drive shaft are driven by different power sources. The seedling box is fixed to the planetary carrier drive shaft.

[0010] The planetary gear planting assembly includes a sun gear, an intermediate gear, planetary gears, an intermediate shaft, and a planetary shaft. The sun gear is mounted on the drive shaft of the planetary carrier and connected to the drive shaft via a gear transmission assembly. The intermediate shaft is fixed to the planting box, and the intermediate gear and the intermediate shaft form a revolute joint. The planetary gears are fixed to the planetary shaft, and the planetary shaft and the planting box form a revolute joint, driving the planting nozzle assembly to rotate. The planting nozzle assembly opens and closes periodically during rotation. The sun gear, intermediate gear, and planetary gears are all spur gears, and the intermediate gear meshes with both the sun gear and the planetary gears.

[0011] Preferably, the seedling box includes a boss shell and a toothed shell, the boss shell and the toothed shell being fixed together. A circular groove is provided inside the boss shell, and a boss bushing is disposed in the circular groove and sleeved on the planetary carrier drive shaft. The boss shell, the boss bushing, and the planetary carrier drive shaft are fixed together by pins.

[0012] Preferably, the gear transmission assembly includes a driving gear, a driven gear, and a driven gear bushing. The driving gear is fixed to the driving shaft and meshes with the driven gear. The driven gear is sleeved outside the planetary carrier drive shaft, and a driven gear bushing is provided between the driven gear and the planetary carrier drive shaft. The driven gear is fixed to the sun gear.

[0013] Preferably, the drive shaft and the planetary carrier drive shaft are driven by a power transmission assembly. The power transmission assembly includes a first drive sprocket, a first driven sprocket, a first chain, a second drive sprocket, a second driven sprocket, and a second chain. The first driven sprocket is connected to the drive shaft and is connected to the first drive sprocket via the first chain. The second driven sprocket is connected to the planetary carrier drive shaft and is connected to the second drive sprocket via the second chain.

[0014] More preferably, both the first and second drive sprockets are driven by a drive assembly. The drive assembly includes a first servo motor, a second servo motor, a first reducer, and a second reducer. The output shaft of the first servo motor is connected to the first drive sprocket via the first reducer, and the output shaft of the second servo motor is connected to the second drive sprocket via the second reducer. Both the first and second servo motors are controlled by a controller.

[0015] Preferably, the planting nozzle assembly includes a fixed plate, a left swing arm, a right swing arm, a left planting nozzle, a right planting nozzle, a cam, a roller, a tension spring, and a pin. The fixed plate is fixed to the planetary shaft. Both the left and right swing arms are hinged to the fixed plate. One of the left and right swing arms is fixed to the pin, and the other has a groove that forms a rolling friction pair with the pin. The left planting nozzle is fixed to the left swing arm, and the right planting nozzle is fixed to the right swing arm. The cam is fixed to the outer surface of the seedling box. The roller is hinged to the right swing arm and forms a cam pair with the cam. The roller is located above the hinge positions of the left and right swing arms and the fixed plate. A U-shaped frame is fixed to each of the left and right planting nozzles, and a connecting ring is fixed to each of the two U-shaped frames. The two ends of the tension spring are connected to the two connecting rings.

[0016] Preferably, encoder one is mounted on the drive shaft, and encoder two is mounted on the planetary carrier drive shaft.

[0017] The present invention discloses a method for adjusting the plant spacing of an adjustable-spacing potted seedling planting mechanism, as detailed below:

[0018] The controller determines the planting cycle based on the plant spacing and the horizontal operating speed of the frame relative to the soil. It then calls upon the target angular displacement mapping relationship between the corresponding sun gear and the planting box. Based on the transmission ratio from the drive shaft to the sun gear, it converts the angular displacement of the drive shaft detected by encoder one into the angular displacement of the sun gear. It compares the angular displacement relationship of the planting box detected by the sun gear and encoder two with the target angular displacement mapping relationship. If a deviation exists, it corrects the control quantities of servo motor one and servo motor two, forming a coordinated speed-changing motion relationship between them. If the plant spacing or horizontal operating speed is changed, the corresponding target angular displacement mapping relationship between the sun gear and the planting box is invoked, thereby altering the coordinated speed-changing motion relationship between servo motor one and servo motor two. This results in changes to the output motion of the planetary gears and the static trajectory of the planting nozzle.

[0019] Preferably, the plant spacing is H, and the horizontal operating speed of the machine frame relative to the soil is... The seedling planting cycle is ,but:

[0020] .

[0021] Preferably, an electronic cam curve is used to represent the target angular displacement mapping relationship between the sun gear and the seedling box. The angular displacement of the seedling box relative to the frame is used as the main variable, and the angular displacement of the sun gear relative to the frame is used as the secondary variable. The controller generates target motion commands for servo motor one and servo motor two at each control moment based on the angular displacement mapping relationship.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The planetary gear system planting assembly of this invention uses spur gears for motion transmission. Each gear meshing pair maintains a fixed mechanical transmission ratio during operation, featuring smooth transmission, strong load-bearing capacity, and easy processing. Two independent power sources drive the sun gear and the planting box respectively, and the controller changes the angular displacement relationship between the two within a planting cycle, causing the planetary gears to generate different output motions, thereby changing the static trajectory of the tip of the planting nozzle assembly. The planting cycle is determined based on the set plant spacing and the horizontal operating speed of the frame relative to the soil, and different static trajectories are superimposed with the corresponding horizontal operating motions to form a dynamic trajectory that meets the requirements of different plant spacing conditions. Different plant spacing operations can be achieved without redesigning or replacing transmission components such as gears and sprockets, improving the adaptability of the planting mechanism to different crops and different agronomic plant spacing requirements. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural schematic diagram of an adjustable-spacing potted seedling planting mechanism according to the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the seedling box, the planetary gear seedling assembly, and the planting nozzle assembly in this invention;

[0026] Figure 3 This is a schematic diagram of the gear transmission assembly in this invention;

[0027] Figure 4 This is a schematic diagram of the power transmission component and drive component in this invention;

[0028] Figure 5 This is a schematic diagram of the coaxial assembly structure of the driven gear, sun gear, and planet carrier drive shaft in this invention;

[0029] Figure 6 This is a control flowchart of the plant spacing adjustment method of the present invention;

[0030] Figure 7 This is a schematic diagram of the simulated seedling planting experiment of the present invention;

[0031] Figure 8 It is a graph showing the relationship between the angular displacement of the sun wheel and the target angular displacement of the seedling box for different plant spacings;

[0032] Figure 9 This is a schematic diagram of the static trajectory of the planting nozzle, the dynamic trajectory of the planting nozzle, and the plant spacing when the plant spacing is 200mm.

[0033] In the diagram: 1. Frame; 2. Seedling box; 2-1. Boss housing; 2-2. Toothed housing; 3. Planetary gear seedling assembly; 3-1. Boss bushing; 3-2. Pin; 3-3. Sun gear; 3-4. Intermediate gear; 3-5. Planetary gear; 3-6. Intermediate shaft; 3-7. Planetary shaft; 3-8. Sun gear bushing; 4. Planting nozzle static trajectory; 4-1. Planting nozzle dynamic trajectory; 5. Planting nozzle assembly; 5-1. Fixing plate; 5-2. Left swing arm; 5-3. Right swing arm; 5-4. Left planting nozzle; 5-5. Right planting nozzle; 5-6. Cam; 5-7. Roller; 5-8. Tension spring; 5-9. U-shaped... Frame, 5-10, Connecting ring, 5-11, Pin, 6, Transmission housing, 7, Gear transmission assembly, 7-1, Drive shaft, 7-2, Planetary carrier drive shaft, 7-3, Drive gear, 7-4, Driven gear, 7-5, Driven gear bushing, 8, Power transmission assembly, 8-1, Drive sprocket one, 8-2, Driven sprocket one, 8-3, Chain one, 8-4, Drive sprocket two, 8-5, Driven sprocket two, 8-6, Chain two, 9, Drive assembly, 9-1, Servo motor one, 9-2, Servo motor two, 9-3, Reducer one, 9-4, Reducer two, 10, Conveyor belt, 10-1, Soil trough. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0035] like Figures 1 to 5 As shown, this embodiment provides a potted seedling planting mechanism with adjustable plant spacing, including a frame 1, a planting box 2, a planetary gear planting assembly 3, a planting nozzle assembly 5, a transmission box 6, and a gear transmission assembly 7. The transmission box 6 is fixed on the frame 1, and both the drive shaft 7-1 and the planetary carrier drive shaft 7-2 are rotatably supported on the transmission box 6; the drive shaft 7-1 and the planetary carrier drive shaft 7-2 are driven by different power sources. The planting box 2 is fixed to the planetary carrier drive shaft 7-2, allowing the planting box 2 to rotate relative to the transmission box 6 and the frame 1 along with the planetary carrier drive shaft 7-2.

[0036] like Figure 1 and Figure 2As shown, the seedling box 2 includes a boss shell 2-1 and a toothed shell 2-2. The boss shell 2-1 and the toothed shell 2-2 are fixed together to form a box structure for accommodating and supporting the planetary gear train seedling assembly 3. Figure 2 This is a structural diagram after removing the dental insert housing 2-2, used to show the installation relationship of the boss housing 2-1 and its internal components.

[0037] Furthermore, the planetary gear system seedling assembly 3 includes a sun gear 3-3, an intermediate gear 3-4, planetary gears 3-5, an intermediate shaft 3-6, and a planetary shaft 3-7. A circular groove is provided inside the boss housing 2-1, and the boss bushing 3-1 is disposed within the circular groove and fitted onto the planetary carrier drive shaft 7-2. The boss housing 2-1, the boss bushing 3-1, and the planetary carrier drive shaft 7-2 are fixed by pins 3-2, enabling the planetary carrier drive shaft 7-2 to drive the seedling box 2 to rotate synchronously.

[0038] like Figure 2 and Figure 5 As shown, the sun gear 3-3 is sleeved on the planetary carrier drive shaft 7-2 and connected to the drive shaft 7-1 via a gear transmission assembly 7; a sun gear sleeve 3-8 is provided between the sun gear 3-3 and the planetary carrier drive shaft 7-2. The sun gear sleeve 3-8 is used to separate the sun gear 3-3 from the planetary carrier drive shaft 7-2, so that the sun gear 3-3 can rotate independently relative to the planetary carrier drive shaft 7-2.

[0039] The intermediate shaft 3-6 is fixed on the seedling box 2, and the intermediate wheel 3-4 and the intermediate shaft 3-6 form a rotating pair; the planetary wheel 3-5 is fixed on the planetary shaft 3-7, the planetary shaft 3-7 and the seedling box 2 form a rotating pair, and drive the planting nozzle assembly 5 to rotate. The planting nozzle assembly 5 opens and closes periodically during the rotation.

[0040] Furthermore, the sun gear 3-3, intermediate gear 3-4, and planetary gear 3-5 are all spur gears. The intermediate gear 3-4 meshes with both the sun gear 3-3 and the planetary gear 3-5. The meshing ratio is determined by the gear ratio and remains constant during the seedling planting process. In this embodiment, the sun gear 3-3, intermediate gear 3-4, and planetary gear 3-5 use the same module and number of teeth.

[0041] Furthermore, during operation, the intermediate wheel 3-4 revolves around the planetary frame drive shaft 7-2 along with the seedling box 2, and simultaneously rotates around the intermediate shaft 3-6 under the meshing action of the sun wheel 3-3, transmitting the motion of the sun wheel 3-3 relative to the seedling box 2 to the planetary wheel 3-5. The planetary wheel 3-5 drives the planetary shaft 3-7 to rotate synchronously, and the planetary shaft 3-7 further drives the planting nozzle assembly 5 to move. The actual output motion of the planetary wheel 3-5 is determined by the input motion of the sun wheel 3-3 and the rotation of the seedling box 2.

[0042] As a preferred embodiment, such as Figure 3As shown, the gear transmission assembly 7 includes a driving gear 7-3, a driven gear 7-4, and a driven gear sleeve 7-5. The driving gear 7-3 is fixed to the driving shaft 7-1 and meshes with the driven gear 7-4. The driven gear 7-4 is sleeved on the planetary carrier drive shaft 7-2, and the driven gear sleeve 7-5 is disposed between the driven gear 7-4 and the planetary carrier drive shaft 7-2. The driven gear sleeve 7-5 is coaxially arranged with the planetary carrier drive shaft 7-2 and is used to separate the driven gear 7-4 from the planetary carrier drive shaft 7-2, allowing the driven gear 7-4 to rotate independently relative to the planetary carrier drive shaft 7-2. The driving shaft 7-1 can drive the sun gear 3-3 to rotate via the driving gear 7-3 and the driven gear 7-4.

[0043] Furthermore, such as Figure 5 As shown, the driven gear 7-4 and the sun gear 3-3 have mutually cooperating protrusions and grooves on their opposite end faces. After assembly, they form an end face toothed structure, which enables the driven gear 7-4 and the sun gear 3-3 to form a circumferential transmission connection and rotate synchronously, while not affecting the independent rotation of the planetary carrier drive shaft 7-2.

[0044] In a preferred embodiment, the drive shaft 7-1 and the planetary carrier drive shaft 7-2 are driven by the power transmission assembly 8. Figure 4 As shown, the power transmission assembly 8 includes a drive sprocket 8-1, a driven sprocket 8-2, a chain 8-3, a second drive sprocket 8-4, a second driven sprocket 8-5, and a second chain 8-6. The driven sprocket 8-2 is connected to the drive shaft 7-1 and is connected to the drive sprocket 8-1 via the chain 8-3. The driven sprocket 8-5 is connected to the planetary carrier drive shaft 7-2 and is connected to the drive sprocket 8-4 via the chain 8-6.

[0045] As a preferred embodiment, such as Figure 1 As shown, both drive sprocket 1 8-1 and drive sprocket 2 8-4 are driven by drive assembly 9. Figure 4 As shown, the drive assembly 9 includes a servo motor 9-1, a servo motor 9-2, a reducer 9-3, and a reducer 9-4. The output shaft of servo motor 9-1 is connected to the drive sprocket 8-1 via reducer 9-3. The power output from servo motor 9-1 is transmitted sequentially through reducer 9-3, drive sprocket 8-1, chain 8-3, and driven sprocket 8-2 to the drive shaft 7-1. The output shaft of servo motor 9-2 is connected to the drive sprocket 8-4 via reducer 9-4. The power output from servo motor 9-2 is transmitted sequentially through reducer 9-4, drive sprocket 8-4, chain 8-6, and driven sprocket 8-5 to the planetary carrier drive shaft 7-2, which then drives the seedling box 2 to rotate. Both servo motors 9-1 and 9-2 are controlled by a controller.

[0046] As a preferred embodiment, such as Figure 2 As shown, the planting nozzle assembly 5 includes a fixed plate 5-1, a left swing arm 5-2, a right swing arm 5-3, a left planting nozzle 5-4, a right planting nozzle 5-5, a cam 5-6, a roller 5-7, a tension spring 5-8, a U-shaped frame 5-9, a connecting ring 5-10, and a pin 5-11. The fixed plate 5-1 is fixed to the planetary shaft 3-7. Both the left swing arm 5-2 and the right swing arm 5-3 are hinged to the fixed plate 5-1. One of the left swing arm 5-2 and the right swing arm 5-3 is fixed to the pin 5-11, and the other has a groove that forms a rolling friction pair with the pin 5-11. The left planting nozzle 5-4 is fixed to the left swing arm 5-2, and the right planting nozzle 5-5 is fixed to the right swing arm 5-3.

[0047] Cam 5-6 is fixed to the outer surface of the seedling box 2; roller 5-7 is hinged to the right swing arm 5-3 and forms a cam pair with cam 5-6. Roller 5-7 is located above the hinge position of the left swing arm 5-2 and the right swing arm 5-3 with the fixed plate 5-1. Roller 5-7 moves with the right swing arm 5-3 relative to cam 5-6 and contacts the push section, the far rest section and the return section of cam 5-6 in sequence, so that the left planting nozzle 5-4 and the right planting nozzle 5-5 complete the opening, holding the opening and closing actions in sequence.

[0048] A U-shaped frame 5-9 is fixed on the left planting nozzle 5-4 and the right planting nozzle 5-5 respectively. A connecting ring 5-10 is fixed on each of the two U-shaped frames 5-9. The two ends of the tension spring 5-8 are connected to the two connecting rings 5-10, which are used to apply a closing force to the left planting nozzle 5-4 and the right planting nozzle 5-5, so that the left planting nozzle 5-4 and the right planting nozzle 5-5 return to their original position and close after the seedling is released.

[0049] In a preferred embodiment, encoder one is mounted on drive shaft 7-1 to detect the angular displacement of drive shaft 7-1; encoder two is mounted on planetary carrier drive shaft 7-2 to detect the angular displacement of seedling box 2.

[0050] This embodiment provides a method for adjusting the plant spacing of an adjustable potted seedling planting mechanism, as detailed below:

[0051] like Figure 6As shown, the controller determines the time interval (planting cycle) between adjacent planting events based on the plant spacing and the horizontal operating speed of the frame relative to the soil (the speed at which the frame moves forward with the transplanter when it is installed on the transplanter). It then calls the target angular displacement mapping relationship between the sun gear 3-3 and the planting box 2. Based on the transmission ratio from the drive shaft 7-1 to the sun gear 3-3, it converts the angular displacement of the drive shaft detected by encoder one into the angular displacement of the sun gear 3-3. The controller then compares the relationship between the angular displacement of the planting box 2 detected by the sun gear 3-3 and encoder two (which is equal to the angular displacement of the planetary carrier drive shaft 7-2) with the target angular displacement mapping relationship. When there is a deviation between the two, the controller corrects the control quantities of servo motor one 9-1 and servo motor two 9-2, ultimately forming the input coordinated speed change motion relationship of servo motor one 9-1 and servo motor two 9-2. In this embodiment, an electronic cam curve is used to represent the target angular displacement mapping relationship between the sun gear 3-3 and the seedling box 2 within a seedling cycle. The angular displacement of the seedling box 2 relative to the frame 1 is used as the main variable, and the angular displacement of the sun gear 3-3 relative to the frame 1 is used as the secondary variable. The controller generates target motion commands for servo motor 9-1 and servo motor 9-2 at each control moment based on the angular displacement mapping relationship.

[0052] Furthermore, by changing the plant spacing or horizontal operating speed, the target angular displacement mapping relationship between the sun gear 3-3 and the planting box 2 can be altered, causing the sun gear 3-3 and the planting box 2 to form different coordinated speed-changing motion patterns. This, in turn, changes the output motion of the planetary gear 3-5 and the static trajectory 4 of the planting nozzle. The change in the static trajectory 4 of the planting nozzle is generated by the periodic non-uniform motion relationship input by servo motor 1 9-1 and servo motor 2 9-2, while the transmission ratio inside the planetary gear system planting assembly 3 remains unchanged.

[0053] Furthermore, the electronic cam curves corresponding to different plant spacings and horizontal operating speeds exhibit different curve shapes and local slopes, indicating that under different plant spacings and horizontal operating speeds, the sun wheel 3-3 and the seedling box 2 have different angular displacement relationships within a single seedling cycle. Let the angular displacement of the seedling box 2 relative to the frame 1 be... The angular displacement of the sun gear 3-3 relative to the frame 1 is The target angular displacement mapping relationship between the two can be expressed as:

[0054]

[0055] In the formula, H is the plant spacing. Let H be the target angular displacement mapping function corresponding to the plant spacing H. The local slope of the target angular displacement mapping relationship satisfies:

[0056]

[0057] In the formula, Let ω be the angular velocity of the sun gear 3-3. The angular velocity of the seedling box 2 is given by the local slope of the electronic cam curve, which reflects the angular velocity relationship between the sun gear 3-3 and the seedling box 2.

[0058] Furthermore, when the controller switches the electronic cam curve corresponding to the plant spacing and horizontal operating speed, the angular displacement and angular velocity relationship between the sun wheel 3-3 and the seedling box 2 within a seedling cycle changes accordingly, and the output motion of the planet wheel 3-5 changes accordingly, thereby causing the unfolding width, soil entry position and soil exit position of the planting nozzle static trajectory 4 along the operating direction to change.

[0059] As a preferred embodiment, such as Figure 7 As shown, to simulate the seedling planting process under actual transplanter forward conditions, a conveyor belt 10 is installed below the planting nozzle assembly 5, and a soil trough 10-1 filled with soil is installed on the conveyor belt 10. During the test, the frame 1 remains stationary, and the conveyor belt 10 drives the soil trough 10-1 to move horizontally in the direction of ( Figure 9 The direction of the straight arrow in the middle is opposite to the actual forward direction of the transplanter, so as to equivalently simulate the horizontal relative movement between the frame 1 and the soil during the actual seedling planting process.

[0060] Furthermore, initially, the planting nozzle assembly 5 is located at the seedling planting position and is in a vertical state. When the planting nozzle assembly 5 moves to the seedling receiving position of the planting nozzle static trajectory 4, the potted seedling is manually placed between the left planting nozzle 5-4 and the right planting nozzle 5-5 to simulate the process of the seedling receiving device supplying seedlings to the planting nozzle assembly 5. The planting nozzle assembly 5 then carries the potted seedling and sequentially completes the actions of transporting the seedling, inserting it into the soil, releasing the potted seedling, removing it from the soil, and resetting.

[0061] Furthermore, such as Figure 8 As shown, the horizontal axis represents the angular displacement of the seedling box 2 relative to the frame 1, and the vertical axis represents the angular displacement of the sun gear 3-3 relative to the frame 1. Figure 8 In Figures (a), (b), and (c), the target angular displacement mapping relationship between the sun wheel 3-3 and the planting box 2 is shown when the plant spacing is 200 mm, 250 mm, and 600 mm, respectively. To demonstrate the periodic repeatability of the electronic cam curve during continuous operation, Figure 8 The diagram shows three consecutive planting cycles, with each 360° rotation of the planting box 2 corresponding to one planting cycle.

[0062] Furthermore, such as Figure 9 As shown, taking the planting operation of potted seedlings with a plant spacing of 200mm as an example, according to... Figure 9As indicated by the arc-shaped arrow, the planting nozzle assembly 5 moves clockwise along the planting nozzle stationary trajectory 4, while the conveyor belt 10 drives the soil trough 10-1 to move in the opposite direction to the actual forward direction of the transplanter. The planting nozzle stationary trajectory 4 is the trajectory of the tip of the planting nozzle assembly 5 relative to the frame 1; after the planting nozzle stationary trajectory 4 and the horizontal movement of the soil trough 10-1 relative to the frame 1 are superimposed, the planting nozzle moving trajectory 4-1 of the planting nozzle assembly 5 relative to the soil trough 10-1 is formed.

[0063] Furthermore, taking the continuous planting of three seedlings in pots as an example, within three consecutive planting cycles, when the planting nozzle component 5 along the [missing information] in each planting cycle... Figure 9 When the planter moves clockwise to the highest position (the receiving position) of the planting nozzle stationary trajectory 4, the potted seedling is manually placed between the left planting nozzle 5-4 and the right planting nozzle 5-5. The planting nozzle assembly 5 continues to move clockwise carrying the potted seedling, completing the actions of transporting the seedling, placing it in the soil, releasing the potted seedling, removing it from the soil, and resetting it in sequence. Thus, the three potted seedlings are planted in the soil trough 10-1, which moves in the opposite direction with the conveyor belt 10. The center distance between the planting positions of two adjacent potted seedlings along the direction of movement of the soil trough 10-1 is denoted as H, which is the plant spacing.

[0064] In other alternative embodiments, other transmission ratios may be used between the sun gear 3-3, the intermediate gear 3-4 and the planetary gear 3-5, and the input coordinated speed change motion relationship between the servo motor 9-1 and the servo motor 9-2 shall be determined according to the transmission ratio used.

Claims

1. A seedling planting mechanism with adjustable spacing, comprising a planting box, a planetary gear planting assembly, a planting nozzle assembly, a transmission box, and a gear transmission assembly, characterized in that: The transmission housing is fixed on the frame, and both the drive shaft and the planetary carrier drive shaft are rotatably supported on the transmission housing. The drive shaft and the planetary carrier drive shaft are driven by different power sources. The seedling box is fixed to the planetary carrier drive shaft. The planetary gear seedling assembly includes a sun gear, an intermediate gear, planetary gears, an intermediate shaft, and a planetary shaft. The sun gear is sleeved on the planetary carrier drive shaft and connected to the drive shaft through a gear transmission assembly. The intermediate shaft is fixed on the seedling box, and the intermediate gear and the intermediate shaft form a revolute pair. The planetary gears are fixed to the planetary shaft, and the planetary shaft and the seedling box form a revolute pair, driving the planting nozzle assembly to rotate. The planting nozzle assembly opens and closes periodically during rotation. The sun gear, intermediate gear, and planetary gears are all spur gears, and the intermediate gear meshes with both the sun gear and the planetary gear.

2. The adjustable spacing potted seedling planting mechanism according to claim 1, characterized in that: The seedling box includes a boss shell and a toothed shell, the boss shell and the toothed shell are fixed together; a circular groove is provided in the boss shell, the boss bushing is provided in the circular groove and sleeved on the planetary carrier drive shaft, the boss shell, the boss bushing and the planetary carrier drive shaft are fixed by pins.

3. The adjustable spacing potted seedling planting mechanism according to claim 1, characterized in that: The gear transmission assembly includes a driving gear, a driven gear, and a driven gear bushing; the driving gear is fixed to the driving shaft and meshes with the driven gear, the driven gear is sleeved outside the planetary carrier drive shaft, and a driven gear bushing is provided between the driven gear and the planetary carrier drive shaft; the driven gear is fixed to the sun gear.

4. The adjustable spacing potted seedling planting mechanism according to claim 1, characterized in that: The drive shaft and planetary carrier drive shaft are driven by a power transmission assembly; the power transmission assembly includes a drive sprocket one, a driven sprocket one, a chain one, a drive sprocket two, a driven sprocket two, and a chain two; the driven sprocket one is connected to the drive shaft and is connected to the drive sprocket one via the chain one; the driven sprocket two is connected to the planetary carrier drive shaft and is connected to the drive sprocket two via the chain two.

5. The adjustable spacing potted seedling planting mechanism according to claim 4, characterized in that: Both the first and second drive sprockets are driven by a drive assembly; the drive assembly includes a first servo motor, a second servo motor, a first reducer, and a second reducer; the output shaft of the first servo motor is connected to the first drive sprocket via the first reducer, and the output shaft of the second servo motor is connected to the second drive sprocket via the second reducer; both the first and second servo motors are controlled by a controller.

6. The adjustable spacing potted seedling planting mechanism according to claim 1, characterized in that: The planting nozzle assembly includes a fixed plate, a left swing arm, a right swing arm, a left planting nozzle, a right planting nozzle, a cam, a roller, a tension spring, and a pin. The fixed plate is fixed to a planetary shaft. Both the left and right swing arms are hinged to the fixed plate. One of the left and right swing arms is fixed to the pin, and the other has a groove that forms a rolling friction pair with the pin. The left planting nozzle is fixed to the left swing arm, and the right planting nozzle is fixed to the right swing arm. The cam is fixed to the outer surface of the seedling box. The roller is hinged to the right swing arm and forms a cam pair with the cam. The roller is located above the hinge positions of the left and right swing arms and the fixed plate. A U-shaped frame is fixed to each of the left and right planting nozzles, and a connecting ring is fixed to each of the two U-shaped frames. The two ends of the tension spring are connected to the two connecting rings.

7. The adjustable-spacing potted seedling planting mechanism according to any one of claims 1 to 6, characterized in that: Encoder 1 is mounted on the drive shaft, and encoder 2 is mounted on the planetary carrier drive shaft.

8. The method for adjusting the plant spacing of an adjustable-spacing potted seedling planting mechanism according to claim 7, characterized in that: The controller determines the planting cycle based on the plant spacing and the horizontal operating speed of the frame relative to the soil. It then calls up the target angular displacement mapping relationship between the corresponding sun gear and the planting box. Based on the transmission ratio from the drive shaft to the sun gear, it converts the angular displacement of the drive shaft detected by encoder one into the angular displacement of the sun gear. It then compares the angular displacement relationship of the planting box detected by the sun gear and encoder two with the target angular displacement mapping relationship. If there is a deviation, it corrects the control quantities of servo motor one and servo motor two, forming an input coordinated variable speed motion relationship between servo motor one and servo motor two. If the plant spacing or horizontal operating speed is changed, the corresponding target angular displacement mapping relationship between the sun gear and the planting box is called up, thereby changing the input coordinated variable speed motion relationship between servo motor one and servo motor two. The output motion of the planetary gears and the static trajectory of the planting nozzle change.

9. The method for adjusting the plant spacing of an adjustable-spacing potted seedling planting mechanism according to claim 8, characterized in that: Let the plant spacing be H, and the horizontal operating speed of the machine frame relative to the soil be... The seedling planting cycle is ,but: 。 10. The method for adjusting the plant spacing of an adjustable-spacing potted seedling planting mechanism according to claim 8, characterized in that: An electronic cam curve is used to represent the target angular displacement mapping relationship between the sun gear and the seedling box. The angular displacement of the seedling box relative to the frame is used as the main variable, and the angular displacement of the sun gear relative to the frame is used as the secondary variable. The controller generates target motion commands for servo motor 1 and servo motor 2 at each control moment based on the angular displacement mapping relationship.

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