Rice transplanter

Abstract

When the HST lever is moved to the neutral position and pressure relief control is performed, there is a risk of plant loss. [Solution] When the planting clutch is engaged and the HST lever is in the neutral position, the control unit performs pressure relief control by swinging the HST trunnion alternately to the reverse and forward sides for a predetermined time or a predetermined number of times. While the pressure relief control is being performed, the control unit keeps the planting clutch disengaged. After the pressure relief control is completed, the HST trunnion is moved to the neutral position and the planting clutch is returned to the engaged position. However, if the HST lever is moved to the forward position before the pressure relief control is completed, the forward detection from the lever sensor is not accepted and is put on hold. After completing the pressure relief control and returning the planting clutch to the engaged position, the HST trunnion is driven according to the forward detection from the lever sensor.

Description

Technical Field

[0001] The present invention relates to a rice transplanter for planting seedlings in a field.

Background Art

[0002] A conventional rice transplanter is a four-wheel drive vehicle provided with left and right front wheels and rear wheels, which are driving wheels, on a work vehicle such as a seedling transplanter that performs operations such as planting seedlings in a field.

[0003] On the front side of the main frame that constitutes the vehicle body skeleton of this traveling vehicle body, a transmission case that transmits driving force to a working machine or the like, and a hydraulic continuously variable transmission device that outputs the driving force supplied from the engine to the transmission case are provided. This continuously variable transmission device is a hydrostatic continuously variable transmission called a so-called HST (Hydro Static Transmission).

[0004] The rotational power of the engine is transmitted to the transmission via the belt transmission part and the continuously variable transmission device. The rotational power shifted by this transmission is separated into traveling power and externally extracted power.

[0005] When stopping the travel, the HST lever (forward and reverse lever) is operated to the neutral position. At that time, the machine body can be surely stopped by pressure release control.

[0006] That is, by the pressure release control, the HST trunnion is moved back and forth in a minute range (for example, for 5 seconds), and it is possible to prevent a decrease in the transmission accuracy to the traveling power and a decrease in the braking performance due to an increase in the oil temperature of the HST and deterioration of parts (Patent Document 1, Patent Document 2).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

[0008] However, in such rice transplanters, there is a regulation that requires the planting clutch to be disengaged when the HST (Hyper-Speed ​​Transmission) is moving in reverse, in order to prevent damage to the inter-plant gear.

[0009] On the other hand, as mentioned above, when the HST lever is in the neutral position, the HST pressure release control causes the HST to move towards the reverse direction, and at that time the engagement clutch is forcibly disengaged.

[0010] After the pressure release is complete, the planting clutch automatically returns to the engaged position. However, if the HST lever is moved to the forward position before this is complete, the planting operation will begin with forward movement.

[0011] As a result, because the vehicle is driven with the clutch disengaged, there is a problem of missing parts for a short distance during that time.

[0012] This invention aims to provide a rice transplanter that can prevent missing plants, taking into consideration the problems of such rice transplanters. [Means for solving the problem]

[0013] The first invention is, A rice transplanter equipped with an electric HST having an HST lever, a lever sensor for detecting the position of the HST lever, and a control unit for driving an HST trunnion based on the output of the lever sensor, and a planting clutch, When the planting clutch is engaged and the HST lever is in the neutral position, the control unit performs pressure relief control by swinging the HST trunnion alternately to the reverse and forward directions for a predetermined time or a predetermined number of times. While the pressure relief control is being performed, the control unit keeps the planting clutch disengaged. The control unit, after completing the pressure relief control, returns the HST trunnion to the neutral position and the planting clutch to the engaged position. However, if the HST lever is in the forward position between the start and completion of the pressure relief control, the control unit does not accept and holds the forward detection from the lever sensor, completes the pressure relief control, and after completion, returns the planting clutch to the engaged position and drives the HST trunnion according to the forward detection from the lever sensor.

[0014] The second aspect of the present invention is: The control unit, while detecting that planting has been engaged by a planting clutch sensor that detects the operation of the planting clutch, prohibits the movement of the HST lever to the reverse side, or even if the HST lever moves to the reverse side, does not drive the HST trunnion to the reverse side, in the first rice transplanter of the present invention.

[0015] The third invention is, The second rice transplanter of the present invention is characterized in that the control unit prohibits the movement of the HST lever to the reverse side, or does not drive the HST trunnion to the reverse side even if the HST lever moves to the reverse side, while the planting clutch sensor is unable to detect whether the planting is on or off due to a malfunction.

[0016] The fourth aspect of the present invention is The second or third rice transplanter of the present invention is characterized in that, even if the HST lever is moved to the reverse side, if the HST trunnion is not driven to the reverse side, the restriction prohibiting movement to the reverse side is released as an emergency action while the planting start button is pressed.

[0017] The fifth aspect of the present invention is a rice transplanter according to the fourth aspect of the present invention, wherein the height of the leveling rotor is increased during straight-line assist driving compared to when driving without straight-line assist driving.

[0018] The sixth aspect of the present invention is It has a mechanism that can change the height of the leveling rotor by an actuator, and when the planting depth is changed, the height of the leveling rotor is automatically changed accordingly to maintain the height of the leveling rotor with respect to the field. This is the fifth rice transplanter of the present invention.

Advantages of the Invention

[0019] According to the first aspect of the present invention, it is possible to prevent the occurrence of missing plants when the HST lever is moved to the neutral position and punching control is performed.

[0020] According to the second to fourth aspects of the present invention, it is possible to prevent damage to the inter-row gears.

[0021] According to the fifth aspect of the present invention, the load is reduced, the durability of the leveling rotor is improved, and mud pushing and water pushing can be reduced.

[0022] According to the sixth aspect of the present invention, even when the planting depth is changed, the height of the leveling rotor with respect to the field surface can be maintained the same as before.

Brief Explanation of Drawings

[0023] [Figure 1] Side view of the rice transplanter according to the embodiment of the present invention [Figure 2] Plan view of the same rice transplanter [Figure 3] Configuration diagram centered on the control unit of the same rice transplanter [Figure 4] Flowchart showing the operation of the control unit of the same rice transplanter [Figure 5] Flowchart showing another operation of the control unit of the same rice transplanter [Figure 6] Flowchart showing another operation of the control unit of the same rice transplanter [Figure 7] Plan view of the field where the same rice transplanter travels [Figure 8] Side view showing the lower part of the seedling planting device of the same rice transplanter [Figure 9] Side view showing the changes in the float and leveling rotor when the planting depth in the seedling planting device of the same rice transplanter is changed [Figure 10]Side view showing the changes in the float and leveling rotor when the planting depth is changed in the seedling planting device of a rice transplanter. [Figure 11] Side view showing the changes in the float and leveling rotor when the planting depth is changed in the seedling planting device of a rice transplanter. [Figure 12] Side view showing the changes in the float and leveling rotor when the planting depth is changed in the seedling planting device of a rice transplanter. [Figure 13] Side view showing the changes in the float and leveling rotor when the planting depth is changed in the seedling planting device of a rice transplanter. [Figure 14] Side view showing the changes in the float and leveling rotor when the planting depth is changed in the seedling planting device of a rice transplanter. [Figure 15] Side view showing the changes in the float and leveling rotor when the planting depth is changed in the seedling planting device of a rice transplanter. [Modes for carrying out the invention]

[0024] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0025] Figure 1 is a left side view of a rice transplanter according to an embodiment of the present invention, and Figure 2 is a top view thereof. Hereafter, the front and rear and left and right will be used with reference to the direction of travel of the rice transplanter.

[0026] In Figure 1, the rice transplanter according to the embodiment of the present invention comprises a vehicle body 1, front wheels 2, rear wheels 3, and an engine 4.

[0027] An electric HST mechanism 5 is installed on the output side of the engine 4 and is connected to the transmission case. This HST mechanism 5 has an HST lever 5a located in the driver's seat, a lever sensor 5b that detects the position of the HST lever 5a, and an HST trunnion 5c.

[0028] A seedling planting device 6 is mounted on the rear of the vehicle body 1 so as to be able to move up and down. 6a is a planting rod for planting seedlings in the field.

[0029] Figure 3 is a control configuration diagram centered on the control unit 7. The control unit 7 receives a detection signal from the lever sensor 5b, which detects the operating position of the HST lever 5a.

[0030] Furthermore, the control unit 7 receives a detection signal from the planting clutch sensor 8a, which detects when the planting clutch 8 is engaged or disengaged.

[0031] Furthermore, the control unit 7 controls the HST trunnion 5c and also controls the planting clutch 8.

[0032] The control flow of the control unit 7 is explained using the flowchart shown in Figure 4.

[0033] Currently, with the planting clutch 8 engaged, the operator moves the HST lever 5a to the neutral position (step S1). For example, this occurs when planting seedlings with the planting clutch 8 engaged while moving forward, and then moving the HST lever 5a to the neutral position to stop the vehicle 1.

[0034] The control unit 7 performs pressure relief control by swinging the HST trunnion 5c alternately to the reverse and forward sides for a predetermined time, for example, 5 seconds, or a predetermined number of times, for example, 5 times (step S2).

[0035] At the same time, disengage the planting clutch 8 (step S2).

[0036] Normally, the operator leaves the HST lever 5a in the neutral position and does not move it forward, so in step S3 the result is NO and the operator proceeds to step S4.

[0037] Therefore, the control unit 7 checks whether a predetermined time has elapsed for the pressure release control or whether the forward and reverse swinging motions have been performed a predetermined number of times (step S4). If the time has not yet elapsed or the number of swinging motions has not been reached, it waits until the time has elapsed or the number of motions has been reached. The planting clutch 8 is left in the disengaged state.

[0038] After a predetermined time has elapsed or the number of cycles has reached a predetermined number, the control unit 7 completes the pressure release control and turns the planting clutch 8 into the engaged state (step S5).

[0039] Next, the control unit 7 checks whether or not it had suspended forward movement detection, which will be described later (step S6).

[0040] Normally, forward detection is not pending, so the result is NO, and the control unit 7 drives the HST trunnion 5c to neutral (step S7).

[0041] Incidentally, before the pressure relief control is completed after it has started, the operator may move the HST lever 5a to the forward position (if YES is selected in step S3).

[0042] In that case, the control unit 7 does not accept the forward detection signal from the lever sensor 5b and puts it on hold (step S8), completes the pressure release control, and engages the planting clutch 8 (step S5).

[0043] Then, since the forward detection signal is held in reserve by the control unit 7's check in step S6, the control unit 7 drives the HST trunnion 5c according to the forward detection signal from the lever sensor 5b (step S9), and the vehicle body 1 moves forward with the planting clutch 8 engaged. Therefore, it is possible to prevent the occurrence of missing plants.

[0044] Figure 5 shows the control details of a rice transplanter according to another embodiment of the present invention.

[0045] Here, if the planting clutch 8 is engaged (step S1), even if the HST lever 5a moves to the reverse position, the control unit 7 does not drive the HST trunnion 5c to the reverse side (step S2). This prevents damage to the inter-plant gears when the planting clutch remains engaged due to a malfunction of the planting motor relay or other reasons, and the HST travel moves to the reverse side.

[0046] Furthermore, if the planting clutch cannot be detected as engaged or disengaged due to a malfunction (open wire, 5V short circuit) in the planting clutch sensor or other components (step S1), the control unit 7 will not drive the HST trunnion 5c in the reverse direction (step S2). In this way, damage to the inter-plant gear can be prevented.

[0047] However, if the planting clutch 8 is engaged, or if the planting clutch cannot be detected as engaged or disengaged due to a malfunction of the planting clutch sensor or other factors (step S1), the HST trunnion 5c will not be driven in the reverse direction. However, as an emergency measure, while the operator is pressing a separately provided planting button (not shown), the restriction prohibiting the driving of the HST trunnion 5c in the reverse direction is released (step S3).

[0048] This is because, as an emergency measure, there are times when it is necessary to reverse the vehicle body 1 to avoid danger.

[0049] Figure 6 shows an example where, if the planting clutch 8 is engaged, or if the planting clutch 8 cannot be detected as engaged or disengaged due to a malfunction in the planting clutch sensor or other components (open circuit, 5V short circuit) (step S1), the movement of the HST lever 5a itself to the reverse position is mechanically prohibited. This also prevents damage to the inter-plant gear.

[0050] Next, another embodiment of the present invention will be described.

[0051] Figures 7 and 8 show the relationship between the straight-line assist and the leveling rotor.

[0052] Figure 7 shows the situation in which straight-line assistance is provided in field 10. In Figure 7, straight-line assistance is provided when driving back and forth in the center of field 10, but not when driving in a circular motion along the headland.

[0053] In such cases, in a rice transplanter equipped with a straight-line assist function, the height of the leveling rotor 9 automatically changes depending on whether the straight-line assist is turned ON or OFF.

[0054] Specifically, when the straight-line assist is ON, the height of the leveling rotor 9 is raised above the standard value, and when the straight-line assist is OFF, the height of the leveling rotor 9 is set to the standard value.

[0055] As described above, when the straight-line assist is ON, the machine is considered to be moving back and forth in the center, so the field 10 is often less rough than the headland. Therefore, the height of the leveling rotor 9 can be raised when the straight-line assist is ON and the machine is moving back and forth in the center, compared to when the straight-line assist is OFF and the machine is moving in the headland.

[0056] By doing this, the load is reduced in central straight-line assist driving by raising the height of the leveling rotor 9, improving the durability of the rotor, and mud and water displacement can be reduced in straight-line assist driving at higher speeds.

[0057] Next, another embodiment of the present invention will be described with reference to Figures 9 to 15.

[0058] Conventionally, the planting depth and the height of the leveling rotor 9 are not linked, so changing the planting depth changes the height of the leveling rotor 9 relative to the field 10. This is because the leveling rotor 9 is connected to the seedling planting device 6. Therefore, if you want to return to the height of the leveling rotor 9 before changing the planting depth, you have to manually change the height of the leveling rotor 9 each time you change the planting depth, and it is difficult to know how much the height needs to be changed.

[0059] Therefore, in a rice transplanter having a mechanism that changes the height of the leveling rotor 9 using an actuator, the height of the leveling rotor 9 is automatically changed according to the planting depth.

[0060] Furthermore, the planting depth and the height of the leveling rotor 9 can be controlled via a monitor, and the depth and height are displayed. This centralizes the information on the monitor, making it easier to operate the planting depth and rotor height, and allowing the current status to be seen at a glance on the monitor.

[0061] Furthermore, conventionally, changing the planting sensitivity dial does not change the height of the leveling rotor 9, which means that the height of the leveling rotor 9 relative to the field surface changes.

[0062] Therefore, the height of the leveling rotor 9 is automatically adjusted according to the planting sensitivity dial. Specifically, when the planting sensitivity dial is set to "soft," the planting depth is shallower, so the height of the leveling rotor 9 is lowered, and when the planting sensitivity dial is set to "hard," the planting depth is deeper, so the height of the leveling rotor 9 is raised.

[0063] Next, another embodiment of the present invention will be described.

[0064] The Ministry of Agriculture, Forestry and Fisheries' "Guidelines for Ensuring Safety Regarding Automated Driving of Agricultural Machinery" and other documents clarify the content of "conditions for runaway" in relation to "taking safety measures to prevent robotic agricultural machinery from running out of control outside the field," as follows: 1. When a rice transplanter is operating under remote monitoring, if it is detected that the tilt of the machine exceeds a predetermined level, it will be judged as an error. 2. In a rice transplanter operating under remote monitoring, if it is detected that communication between each ECU (Serial, Wireless, CAN, etc.) is interrupted for a predetermined period of time or longer without being updated, an error is determined. 3. If an abnormality is detected in the steering motor of a rice transplanter while it is being remotely monitored, it will be determined to be an error. 4. In the case of a rice transplanter operating under remote monitoring, if the machine cannot be stopped even after a command to stop operation has been issued, such as by continuing to detect the rotation of the front and rear wheels, an error will be determined. 5. If a GNSS abnormality (GNSS failure) is detected in a rice transplanter during remote monitoring operation, it will be judged as an error. 6. When a remotely monitored rice transplanter is in operation, if an abnormality such as a disconnection or short circuit is detected in the drive system sensors (HST trunnion, neutral sensor, etc.), it will be determined to be an error. 7. If an abnormality in the drive system (such as clutch disengagement) is detected in a rice transplanter during remote monitoring, it will be judged as an error. 8. If an abnormality in the steering system (such as a steering sensor or phase detection of a 3-layer brushless motor) is detected in a rice transplanter during remote monitoring, it will be judged as an error. 9. If the operation of the main gear lever is detected while a rice transplanter is being remotely monitored, it will be determined to be a manual intervention error. 10. In a rice transplanter operating under remote monitoring, if the operation of the brake (stop) pedal is detected, it is determined to be a manual intervention error. 11. If a decrease in the GNSS reception level (e.g., from fix to float) is detected in a rice transplanter operating under remote monitoring, it will be determined to be a temporary stop error. 12. In the cases described in 1. through 8. above, if an abnormality (error) is detected that makes it difficult to continue work, the HST will be activated to stop, the engine will be stopped, and the brakes will be applied. 13. In the cases described in 1. through 8. above, if an abnormality (error) is detected that makes it difficult to continue the work, the remote operation will be canceled. 14. In the cases described in 9. and 10. above, if a manual intervention error is detected that can be determined to be caused by human operation, the HST will be set to the stop position and the brakes will be applied, but the engine will not be stopped. 15. In the cases described in 9. and 10. above, if a manual intervention error is detected that can be determined to be caused by human operation, the remote control operation will be canceled. 16. In the case of item 11 above, if a decrease in the GNSS reception level is detected, the HST will be set to a stopping position and the brakes will be applied, but the engine will not be stopped. 17. In the case of item 11 above, if a decrease in the GNSS reception level is detected, the remote mode will be continued. 18. In a remotely monitorable rice transplanter, during remote monitoring operation, the user (monitor) shall be able to give instructions for acceleration / deceleration, buzzer / horn sounding, stopping, engine shutdown, and resuming operation via telecontrol using an internet connection or similar means. According to the "Safety Assurance Guidelines," when the user recognizes a warning, they may reduce the driving speed to observe the situation, sound the buzzer / horn to warn a third party on site, or, in some cases, stop the machine.

[0065] Next, another embodiment of the present invention will be described.

[0066] The seedling planting device 6 has a seedling tank 6b and a guide plate 6c for the seedling tank 6b to move back and forth. When storing the rice transplanter in a barn, in the case of a 10-row rice transplanter, the width is large, so the left and right ends of the seedling tank 6b and guide plate 6c may be folded towards the center.

[0067] In this process, the seedling tank 6b moves left and right on the guide plate 6c to plant seedlings, so the question arises as to where on the guide plate 6c it should stop. It is desirable to stop the seedling tank 6b at the center of the guide plate 6c. This is referred to here as "perfect position" control.

[0068] In that case, first move it to the edge, then start it in the center position, begin counting, and control its movement.

[0069] The details will be explained below.

[0070] A switch is provided on the rod of the seedling tank lateral feed shifter, and the switch that is pressed changes depending on the position of the shifter. A gear for detecting rotation is provided on the seedling feed shaft that is linked to the lateral feed of the seedling tank 6b, and a sensor for detecting the rotation of the gear is provided on the frame of the seedling planting device 6.

[0071] By installing gears on the seedling feeding shaft and sensors on the planting section frame, the rotation speed of the seedling feeding shaft can be detected. Combined with the detected number of lateral movements, this also allows for the detection of the amount the seedling tank has moved.

[0072] A switch located at the top of the planting unit is pressed when the seedling tank 6b moves to the end, which cuts off the drive to the planting unit (perfect stop). The system is controlled using a set number of lateral movements and the number of pulses detected from the rotation axis of the seedling feeding shaft. The number of pulses output when the seedling tank 6b moves from the end to the center is set for each lateral movement rotation, and when the set number of pulses is reached, the drive to the planting unit is stopped (the planting clutch 8 is disengaged).

[0073] In this way, the system automatically stops when the seedling tank 6b is positioned from the edge to the center.

[0074] At this point, even if the rising state of the seedling tank 6b's edge detection switch is detected, the control does not terminate. This is because the control starts when the seedling tank 6b is positioned near the edge, thus preventing detection of the edge-positioning switch.

[0075] Pulse counting is performed after the start of the "Pita-naka" control. Since the gear is linked to the lateral movement of the seedling tank 6b, starting the counting from the start of the "Pita-naka" control saves labor.

[0076] To move the seedling tank 6b from an arbitrary position to the center, it is necessary to know the current position of the seedling tank 6b, the distance to the center, and the rotation speed of the planting rod 6a. However, there are advantages to performing precise center control after precise position control. Control can be simplified by utilizing the conventional precise positioning technology.

[0077] If there is no lateral movement detection unit, the pulse count is set to 12 pulses, which is half of the 24 lateral movement counts (control is possible even without a lateral movement count detection unit). Reducing the number of detection units (switches) leads to cost reduction. Furthermore, control can be incorporated even in models without a detection unit.

[0078] Furthermore, the program according to the embodiment of the present invention is a program that causes a computer to execute all or part of the steps (or processes, operations, and actions, etc.) of the operation control method of the present invention described above, and is a program that operates in cooperation with the computer.

[0079] Furthermore, the recording medium according to the embodiment of the present invention is a recording medium that records a program for causing a computer to execute all or part of the steps (or processes, operations, and actions, etc.) of the operation control method of the present invention described above, and is a computer-readable recording medium in which the read program is used in cooperation with the computer.

[0080] Furthermore, the "some steps (or processes, actions, and functions, etc.)" mentioned above refers to one or more of those steps.

[0081] Furthermore, the "actions of the steps (or processes, movements, and actions, etc.)" mentioned above refer to all or part of the actions of the steps mentioned above.

[0082] Furthermore, one way in which the program of the embodiment of the present invention may be used is that it is transmitted through a transmission medium such as the internet, light, radio waves, or sound waves, read by a computer, and operates in cooperation with the computer.

[0083] Furthermore, recording media include ROM (Read Only Memory), among others.

[0084] Furthermore, a computer is not limited to pure hardware such as a CPU (Central Processing Unit), but may also include firmware, an OS (Operating System), and even peripheral devices.

[0085] As mentioned above, the configuration of the present invention may be implemented in software or in hardware. [Industrial applicability]

[0086] This invention is ideal for rice transplanters because it can prevent the occurrence of missing plants when the HST lever is moved to the neutral position and pressure relief control is performed. [Explanation of Symbols]

[0087] 1. Running vehicle 2 Front wheels 3 Rear wheels 4 engines 5 HST mechanism 5a HST lever 5b Lever Sensor 5c HST Trunnion 6 Seedling planting device 6a Planting rod 6b Seedling tank 6c Guide Plate 7 Control Unit 8. Planting clutch 8a Planting clutch sensor 9. Ground leveling rotor 10 fields 11 Floats 12. Planting depth lever

Claims

1. A rice transplanter equipped with an electric HST having an HST lever, a lever sensor for detecting the position of the HST lever, and a control unit for driving an HST trunnion based on the output of the lever sensor, and a planting clutch, When the planting clutch is engaged and the HST lever is in the neutral position, the control unit performs pressure relief control by swinging the HST trunnion alternately to the reverse and forward directions for a predetermined time or a predetermined number of times. While the pressure relief control is being performed, the control unit keeps the planting clutch disengaged. The control unit, after completing the pressure relief control, sets the HST trunnion to the neutral position and returns the planting clutch to the engaged position. However, if the HST lever is in the forward position between the start and completion of the pressure relief control, the control unit does not accept the forward detection from the lever sensor and holds it in reserve. After completing the pressure relief control and returning the planting clutch to the engaged position, the control unit drives the HST trunnion according to the forward detection from the lever sensor.

2. The rice transplanter according to claim 1, wherein the control unit, while detecting that planting has been engaged by a planting clutch sensor that detects the operation of the planting clutch, prohibits the movement of the HST lever to the reverse side, or does not drive the HST trunnion to the reverse side even if the HST lever moves to the reverse side.

3. The rice transplanter according to claim 2, wherein the control unit prohibits the movement of the HST lever to the reverse side, or does not drive the HST trunnion to the reverse side even if the HST lever moves to the reverse side, while the planting clutch sensor is unable to detect the on / off of planting due to a malfunction.

4. The rice transplanter according to claim 2 or 3, wherein if the HST lever is moved to the reverse side but the HST trunnion is not driven to the reverse side, the restriction prohibiting movement to the reverse side is released as an emergency action while the planting start button is pressed.

5. The rice transplanter according to claim 4, having a mechanism that allows the height of the leveling rotor to be changed by an actuator, wherein the height of the leveling rotor is increased during straight-line assist driving compared to when driving without straight-line assist driving.

6. The rice transplanter according to claim 5, having a mechanism that can change the height of the leveling rotor by an actuator, and which automatically changes the height of the leveling rotor in accordance with the change in planting depth to maintain the height of the leveling rotor relative to the field.

Images