A high-speed precision seed metering device based on watt linkage active damping device

Abstract

The application discloses a high-speed precision seed metering device active damping device based on a Watt linkage; a seed metering device and a high-precision position sensor are installed on a shell; a first side column and a second side column are respectively fixed to two ends of a top beam; first one-long-rod mounting points and second one-long-rod mounting points of first and second Watt linkage groups are connected with first side column bearings of a rack, and first two-long-rod mounting points and second two-long-rod mounting points of the first and second Watt linkage groups are connected with second side column bearings of the rack; first fulcrums and second fulcrums of the first and second Watt linkage groups are hinged with Watt linkage fixing holes on the shell; upper ends and lower ends of first and second air cylinders are respectively fixed with the rack and the shell, and the lower ends of the first and second air cylinders are respectively fixedly connected with first and second sides of the shell. The application adopts the Watt linkage structure, can effectively prevent the lateral deviation of the seed metering device, and keeps the longitudinal vibration amplitude in a small range.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of seeding machine parts of seeding, and particularly relates to a high-speed precision seed metering device active damping device based on a Watt linkage. BACKGROUND

[0002] In corn planting in China, precision seeding technology is widely used to improve seeding accuracy and thus improve corn germination rate, emergence rate and final yield. As a key component of precision seeding technology, the stability of the attitude of the seed metering device directly determines the seeding accuracy and the qualified rate.

[0003] In field work, due to the complex farmland topography, the changes of soil hardness and humidity often cause the ground to be uneven, which is particularly prominent when the seeding machine is working at high speed. During high-speed travel, the seeding machine will not only be subjected to strong jolts caused by the terrain, but also be subjected to severe vibrations caused by the high-speed operation of the engine and the transmission system. These vibrations significantly affect the running stability of the seeding machine and the working attitude of the seed metering device, causing the opening and closing of the seed discharge port to frequently fluctuate, resulting in a significant decrease in seed metering accuracy.

[0004] The damage to seed metering accuracy directly leads to uneven seeding and unbalanced distribution of crops in the field: part of the area is limited in growth due to resource competition caused by excessive seed density, and other areas are caused by seedling deficiency or broken ridges, resulting in waste of land resources. This problem of seeding quality not only weakens the crop yield, but also significantly increases the difficulty of field management. The vibration under high-speed operation exacerbates the complexity and cost of seedling supplement, weeding and fertilization.

[0005] Scholars at home and abroad have carried out a number of technical researches and innovations on the problem of missed seeding caused by vibration during high-speed seed metering, and have improved the structure of the seed metering device to improve the operation reliability. However, these improvements are made by improving the seed metering device to improve the seed metering performance, thus having the problem of high structural complexity. At the same time, these researches are mostly focused on the optimization of the seed transmission process, so the vibration is still not effectively solved. Therefore, a damping device for the seed metering device is needed to solve the problem of difficulty in ensuring the stability of the overall attitude of the seed metering device. SUMMARY

[0006] In view of the demand for high-speed precision seeding in modern agriculture in the background art, the application provides a high-speed precision seed metering device active damping device based on a Watt linkage, which can ensure the uniform distribution of seeds in the field, reduce the seeding quality problems caused by vibration, and thus improve the production efficiency of corn, realize efficient and accurate mechanized seeding operation, and the technical scheme comprises a shell, a rack, a first cylinder, a second cylinder, an air pump, a first tension spring and a second tension spring, wherein the shell is provided with a seed metering device and a high-precision attitude sensor. The frame fixed with the tractor frame comprises a top beam, a first side column, a second side column and a bottom sill which enclose a rectangular frame, wherein the first side column and the second side column are respectively fixed at both ends of the top beam; the first one long rod mounting point and the second one long rod mounting point of the first Watt linkage group and the second Watt linkage group are connected with the first side column bearing of the frame, and the first two long rod mounting points and the second two long rod mounting points of the first Watt linkage group and the second Watt linkage group are connected with the second side column bearing of the frame; the first fulcrum and the second fulcrum of the first Watt linkage group and the second Watt linkage group are hinged with the Watt linkage fixing hole on the shell, and the shell is displaced along the line connecting the first fulcrum and the second fulcrum; The upper ends of the first cylinder and the second cylinder are respectively fixed with the first side column and the second side column, and the lower ends of the first cylinder and the second cylinder are fixedly connected with the cylinder fixing hole on the first side and the second side of the shell; the air ports at both ends of the first cylinder body are connected with the air pump through the two-position three-way electromagnetic valve, and the air ports at both ends of the second cylinder body are respectively provided with the speed regulating valve; the first two-position three-way electromagnetic valve and the high-precision position sensor are connected with the control system; the upper ends of the first tension spring and the second tension spring are connected with the first side column and the second side column respectively; The upper ends of the first tension spring and the second tension spring are connected with the first side column and the second side column through the tension spring frame fixing pin, and the lower ends of the first tension spring and the second tension spring are connected with the first side and the second side of the shell through the tension spring shell fixing pin and the thin hexagonal nut; wherein the tension spring shell fixing pin passes through the tension spring fixing hole on the shell, and the two thin hexagonal nuts below are hung from below the tension spring fixing hole, and the thin hexagonal nut and the tension spring shell fixing pin are threadedly connected.

[0007] The first Watt linkage group comprises a first group of first long rods, a first group of short rods and a first group of second long rods, and the first side column, the first group of first long rods, the first group of short rods, the first group of second long rods and the second side column are sequentially connected through bearings, and the first one long rod mounting point in the middle of the first group of short rods is hinged with the shell; the lengths of the first group of first long rods and the first group of second long rods are equal; The second Watt linkage group comprises a second group of first long rods, a second group of short rods and a second group of second long rods, and the first side column, the second group of first long rods, the second group of short rods, the second group of second long rods and the second side column are sequentially connected through bearings, and the second one long rod mounting point in the middle of the second group of short rods is hinged with the shell; the lengths of the second group of first long rods and the second group of second long rods are equal.

[0008] The first fulcrum is arranged at the center of the first group of short rods, and the distance between the first fulcrum and the first group of first long rod connecting point and the first group of second long rod connecting point is equal; The second fulcrum is arranged at the center of the second group of short rods, and the distance between the second fulcrum and the second group of first long rod connecting point and the second group of second long rod connecting point is equal.

[0009] The first group of first long rods, the first group of second long rods, the second group of first long rods and the second group of second long rods are identical in structure and each comprises a screw rod, two rod end joints, a deep groove ball bearing and a screw clamping mechanism; the inner sides of the two rod end joints are connected to the screw rod through the screw clamping mechanism, and the outer ends of the two rod end joints are each provided with a deep groove ball bearing, which is fixed in the rod end joint.

[0010] The air pump is fixed to the underbody.

[0011] The present application has the following advantages:

[0012] 1. The present application adopts a Watt linkage structure, which can effectively prevent the transverse deviation of the seed metering device and keep the longitudinal vibration amplitude and acceleration within a small range. By effectively limiting the transverse and longitudinal deviation of the seed metering device during operation, the accuracy of the seeding interval is ensured, thereby significantly improving the stability and qualification rate of seeding.

[0013] 2. The present application integrates a suspension damping and active control system, which can effectively buffer the adverse effects of frame vibration, reduce the vibration amplitude and acceleration of the seed metering device, reduce the seed drop and missed planting phenomenon, and improve the reliability of the operation.

[0014] 3. The suspension damping structure of the present application is simple in design, small in transverse proportion and small in space occupation, and is easy to install and use in complex farmland environment. At the same time, the maintenance cost and use difficulty of the overall equipment are reduced, the efficiency of crop planting is improved, and the missed planting rate is reduced; in particular, the corn seeding efficiency and operation quality can be greatly improved.

[0015] 4. By adjusting the opening of the speed regulating valve to change the damping coefficient, the second air cylinder provides effective energy buffering, so that the damping device adapts to various vibration environments, thereby improving the overall seeding quality and efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is an overall structure isometric view of the embodiment of the high-speed precision seed metering device active damping device based on the Watt linkage of the present application; Figure 2 It is a rear view of the overall structure in the embodiment of the present application; Figure 3 It is a side view of the overall structure in the embodiment of the present application; Figure 4 It is a front view of the overall structure in the embodiment of the present application; Figure 5 It is a shell structure diagram in the embodiment of the present application; Figure 6 It is a structure diagram of two groups of Watt linkage groups in the embodiment of the present application; Figure 7Structure diagram of each long rod in the Watt linkage group in the embodiment of the present application; Figure 8 Structure diagram of the tension spring suspension group in the embodiment of the present application; Figure 9 Structure diagram of the cylinder active control group in the embodiment of the present application; Figure 10 Structure diagram of the first cylinder damping group in the embodiment of the present application; Figure 11 Structure diagram of the second cylinder damping group in the embodiment of the present application.

[0017] Wherein, 100 - shell, 110 - cylinder fixing hole, 120 - tension spring fixing hole, 130 - Watt linkage fixing hole, 140 - seed metering device fixing hole, 200 - first Watt linkage group, 210 - first group of first long rod, 211 - first long rod mounting point, 220 - first group of short rod, 221 - first fulcrum, 230 - first group of second long rod, 231 - second long rod mounting point, 300 - second Watt linkage group, 310 - second group of first long rod, 311 - second long rod mounting point, 320 - second group of short rod, 321 - second fulcrum, 330 - second group of second long rod, 331 - second long rod mounting point, 400 - machine frame, 410 - first side column, 420 - second side column, 500 - first tension spring suspension group, 510 - tension spring machine frame fixing pin, 530 - tension spring shell fixing pin, 540 - thin hexagonal nut, 700 - first cylinder damping group, 720 - first cylinder, 750 - two-position three-way electromagnetic valve, 760 - air pump, 770 - high-precision pose sensor, 800 - second cylinder damping group, 820 - second cylinder, 830 - speed regulating valve, 600 - second tension spring suspension group, 900 - seed metering device, 212 - screw rod, 213 - screw clamping mechanism, 215 - deep groove ball bearing. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below with reference to the accompanying drawings.

[0019] As Figures 1-11 shown in the embodiment of the present application, comprising: Seed metering device 900 for uniform seed distribution, thereby sowing, through the seed metering device fixing hole 140 on the shell 100 and the shell 100 fixed; Shell 100 for installing seed metering device 900 and high-precision pose sensor 770, the first fulcrum 221 and the second fulcrum 321 of the first Watt linkage group 200 and the second Watt linkage group 300 are hinged with the Watt linkage fixing hole 130 on the shell 100; A frame 400, fixed to a tractor frame, includes: a top beam 430 forming a rectangular frame, a first side post 410, a second side post 420, and a bottom sill 440, wherein the first side post 410 and the second side post 420 are respectively fixed to both ends of the top beam 430; the first long rod mounting point 211 and the second long rod mounting point 311 of the first Watt's linkage 200 and the second Watt's linkage 300 are bearing connected to the first side post 410 of the frame 400, and the first long rod mounting points 231 and 221 of the first Watt's linkage 200 and the second long rod mounting points 311 are bearing connected to the first side post 410 of the frame 400. The rod mounting point 331 is connected to the bearing of the second side column 420 of the frame 400; two sets of proportionally sized (1:1 in this embodiment) first Watt's linkage group 200 and second Watt's linkage group 300 constrain the movement direction of the housing 100 to the direction of the line connecting the first fulcrum 221 and the second fulcrum 321, that is, the line connecting the two fulcrums is in the vertical direction; due to the constraint of the line connecting the two fulcrums in the two sets of Watt's linkages, the frame 400 has only 1 degree of freedom; therefore, when the field operation encounters vibration, the seed meter will not shift laterally, and the longitudinal shift is also kept within a small range. This suspension mechanism effectively avoids the longitudinal or lateral rotation of the mechanism, thereby maximizing the consistency of the sowing interval and improving the stability of the structure; The first cylinder 720 and the second cylinder 820 are respectively fixed to the first side post 410 and the second side post 420 at their upper ends, and respectively fixed to the cylinder fixing holes 110 on the first and second sides of the housing 100 at their lower ends. The air ports at both ends of the cylinder body of the first cylinder 720 are respectively connected to the air pump 760 through the two-position three-way solenoid valve 750. The air ports at both ends of the cylinder body of the second cylinder 820 are equipped with speed regulating valves 830. The first two-position three-way solenoid valve 750 and the high-precision position and posture sensor 770 are connected to the control system. When working, the air pump 760 controls and pulls the first cylinder 720 through the first and second position three-way solenoid valve 750, causing the frame 400 to be in a suspended state; the air pump 760 is fixed to the bottom sill 440. A first tension spring 500 and a second tension spring 600 are connected at their upper ends to a first side post 410 and a second side post 420, respectively. The upper ends of both springs are pinned to the first side post 410 and the second side post 420 via a tension spring frame fixing pin 510. The lower ends of both springs are connected to the first and second sides of the housing 100 via a tension spring housing fixing pin 530 and a thin hexagonal nut 540. The tension spring housing fixing pin 530 passes through a tension spring fixing hole 120 on the housing 100. Two thin hexagonal nuts 540 are hung from below the tension spring fixing hole 120. The thin hexagonal nuts 540 are threadedly connected to the tension spring housing fixing pin 530, thereby tightening the first tension spring 500 and the second tension spring 600 through their respective tension spring housing fixing pins 530. The first tension spring 500 and the second tension spring 600 allow the seed metering device to be suspended in a stable horizontal position even when the air pump 760 is not working, and also form a flexible connection between the seed metering device and the frame. This can also buffer the impact of frame vibration on the seed metering device during sowing (when the air pump 760 and the high-precision posture sensor 770 are working). By selecting an appropriate spring stiffness coefficient, the optimal response speed and buffering effect can be achieved, thereby reducing the missed sowing rate and improving the sowing qualification rate.

[0020] like Figure 11 The cylinder damping assembly 800 shown is used for energy buffering and vibration reduction of the seed metering device 900, and includes a second cylinder 820 and two speed regulating valves 830. When the free end of the second cylinder 820 reciprocates with the vibration of the housing 100 and the seed metering device 900, its weak damping can dissipate the vibration energy of the seed metering device. When facing vibrations of different frequencies and amplitudes, the damping coefficient of the cylinder damping can be adjusted by adjusting the opening of the speed regulating valves, achieving high damping for large amplitudes and low damping for small amplitudes, ensuring the stability of the seed metering device and a more suitable buffering effect.

[0021] like Figure 10 The active cylinder control group 700 shown is used for active position control and vibration reduction of the seed metering device 900. It includes: a first cylinder 720, a two-position three-way solenoid valve 750, an air pump 760, and a high-precision position sensor 770. The high-precision position sensor 770 collects the vibration data of the seed metering device. Based on the vibration amplitude, the air pressure of the air pump 760 is dynamically adjusted; based on the direction of vibration, the opening direction of the two-position three-way solenoid valve 750 is adjusted to achieve active position control of the seed metering device.

[0022] like Figure 2 and Figure 6The first Watt's linkage assembly 200 shown includes: a first group of first long rods 210, a first group of short rods 220, and a first group of second long rods 230. The first side post 410, the first group of first long rods 210, the first group of short rods 220, the first group of second long rods 230, and the second side post 420 are connected in sequence by bearings. The first long rod mounting point 211 in the middle of the first group of short rods 220 is hinged to the housing 100. The lengths of the first group of first long rods 210 and the first group of second long rods 230 are equal, and the length ratio of the first group of first long rods 210 to the first group of short rods 220 is 3:1. A first fulcrum 221 is provided in the center of the first group of short rods 220, and the distance between the first fulcrum 221 and the connection point of the first group of first long rods 210 and the connection point of the first group of second long rods 230 is equal.

[0023] like Figure 2 and Figure 7 The second Watt's linkage assembly 300 shown includes: a second set of first long rods 310, a second set of short rods 320, and a second set of second long rods 330. The first side post 410, the second set of first long rods 310, the second set of short rods 320, the second set of second long rods 330, and the second side post 420 are connected in sequence by bearings. The mounting point 311 of the second set of short rods 320 and the second set of first long rods is hinged to the housing 100. The lengths of the second set of first long rods 310 and the second set of second long rods 330 are equal, and the length ratio of the second set of first long rods 310 to the second set of short rods 320 is 3:1. A second fulcrum 321 is provided in the center of the second set of short rods 320, and the distance between the second fulcrum 321 and the connection point of the second set of first long rods 310 and the connection point of the second set of second long rods 330 is equal.

[0024] like Figure 8 As shown, the first long rod 210 of the first group, the second long rod 230 of the first group, the first long rod 310 of the second group, and the second long rod 330 of the second group have the same structure, all including: a screw 212, two rod end joints 216, a deep groove ball bearing 215, and a screw clamping mechanism 213; wherein, the inner sides of the two rod end joints 216 are connected to the screw 212 through the screw clamping mechanism 213, and the outer ends of the two rod end joints 216 are equipped with deep groove ball bearings 215. The deep groove ball bearings 215 are interference-fitted into the rod end joints 216. The deep groove ball bearings and the hinge structure make the rotational resistance of the overall mechanism small, which is beneficial to the operation of the vibration damping device.

[0025] In a static state, two tension springs (first tension spring 500 and second tension spring 600) ensure the positioning of the seed meter by pulling the frame fixing pin and the housing fixing pin; the length of the tension springs can be changed by adjusting the position of the thin hexagonal nut 540 on the housing positioning pin.

[0026] During operation, the air pump 760 is turned on first, and the first cylinder 720 is contracted by controlling the two-position three-way solenoid valve 750, which in turn causes the seed metering device 900 to reach the working height.

[0027] The sowing operation then begins. During the sowing process, the cylinder active control group 700 monitors the displacement of the seed metering device in real time through a high-precision position sensor 770. When the deviation exceeds a set threshold, the system activates active damping and adjusts the cylinder action through closed-loop PID control: when the seed metering device shifts upward, the upper port of the two-position three-way solenoid valve 750 is pressurized and the lower port is released, causing the first cylinder 720 to extend and the seed metering device 900 to move downward; when the seed metering device shifts downward, the lower port of the two-position three-way solenoid valve 750 is pressurized and the upper port is released, causing the first cylinder 720 to shorten and the seed metering device 900 to move upward. The control system dynamically adjusts the air pressure input of the air pump 760 according to the magnitude of the deviation, achieving precise displacement control, and automatically stops adjustment when the deviation shrinks to within the dead zone, significantly improving the stability of the seed metering device and the sowing accuracy.

[0028] In this embodiment, DA-VMD and wavelet thresholding are used together to optimize the displacement signal emitted by the high-precision pose sensor 770 for noise reduction.

[0029] When in operation, the two tension springs can also reduce vibration acceleration and act as a buffer.

Claims

1. An active vibration damping device for a high-speed precision seed metering device based on a Watt's linkage, characterized in that, include: The machine includes a housing (100), a frame (400), a first cylinder (720), a second cylinder (820), an air pump (760), a first tension spring (500), and a second tension spring (600), wherein a seed metering device (900) and a high-precision position sensor (770) are installed on the housing (100). The frame (400) fixed to the tractor frame includes: a top beam (430) forming a rectangular frame, a first side post (410), a second side post (420), and a bottom sill (440), wherein the first side post (410) and the second side post (420) are respectively fixed to both ends of the top beam (430); the first long rod mounting point (211) and the second long rod mounting point (311) of the first Watt's linkage (200) and the second Watt's linkage (300) are bearing connected to the first side post (410) of the frame (400), and the first Watt's linkage... The first and second long rod mounting points (231) of the connecting rod assembly (200) and the second Watt's connecting rod assembly (300) are connected to the bearing of the second side column (420) of the frame (400); the first fulcrum (221) and the second fulcrum (321) of the first Watt's connecting rod assembly (200) and the second Watt's connecting rod assembly (300) are hinged to the Watt's connecting rod fixing hole (130) on the housing (100), and the housing (100) is displaced along the line connecting the first fulcrum (221) and the second fulcrum (321); The upper ends of the first cylinder (720) and the second cylinder (820) are fixed to the first side post (410) and the second side post (420) respectively. The lower ends of the first cylinder (720) and the second cylinder (820) are fixedly connected to the cylinder fixing holes (110) on the first side and the second side of the housing (100) respectively. The air ports at both ends of the cylinder body of the first cylinder (720) are connected to the air pump (760) through the two-position three-way solenoid valve (750) respectively. The air ports at both ends of the cylinder body of the second cylinder (820) are equipped with speed regulating valves (830). The first two-position three-way solenoid valve (750) and the high-precision position and posture sensor (770) are connected to the control system. The upper ends of the first tension spring (500) and the second tension spring (600) are connected to the first side post (410) and the second side post (420) respectively.

2. The active vibration damping device for a high-speed precision seed metering device based on a Watt's linkage according to claim 1, characterized in that, The upper ends of the first tension spring (500) and the second tension spring (600) are pinned to the first side post (410) and the second side post (420) by tension spring frame fixing pin (510). The lower ends of the first tension spring (500) and the second tension spring (600) are connected to the first side and the second side of the housing (100) by tension spring housing fixing pin (530) and thin hexagonal nuts (540). The tension spring housing fixing pin (530) passes through the tension spring fixing hole (120) on the housing (100), and the two thin hexagonal nuts (540) below are hooked from below the tension spring fixing hole (120). The thin hexagonal nuts (540) and the tension spring housing fixing pin (530) are threaded together.

3. The active vibration damping device for a high-speed precision seed metering device based on a Watt's linkage according to claim 1, characterized in that, The first Watt linkage assembly (200) includes: a first group of first long rods (210), a first group of short rods (220), and a first group of second long rods (230). The first side post (410), the first group of first long rods (210), the first group of short rods (220), the first group of second long rods (230), and the second side post (420) are connected in sequence by bearings. The first long rod mounting point (211) in the middle of the first group of short rods (220) is hinged to the housing (100). The lengths of the first group of first long rods (210) and the first group of second long rods (230) are equal. The second Watt linkage assembly (300) includes: a second group of first long rods (310), a second group of short rods (320), and a second group of second long rods (330). The first side post (410), the second group of first long rods (310), the second group of short rods (320), the second group of second long rods (330), and the second side post (420) are connected in sequence by bearings. The mounting point (311) of the second group of short rods (320) and the second long rod is hinged to the housing (100). The lengths of the second group of first long rods (310) and the second group of second long rods (330) are equal.

4. The active vibration damping device for a high-speed precision seed metering device based on a Watt's linkage according to claim 3, characterized in that, The first fulcrum (221) is located in the center of the first group of short rods (220), and the distance between the first fulcrum (221) and the connection point of the first long rod (210) and the connection point of the second long rod (230) of the first group is equal; The second fulcrum (321) is located in the center of the second group of short rods (320). The distance between the second fulcrum (321) and the connection point of the first long rod (310) of the second group and the connection point of the second long rod (330) of the second group is equal.

5. The active vibration damping device for a high-speed precision seed metering device based on a Watt's linkage according to claim 3 or 4, characterized in that, The first long rod (210) of the first group, the second long rod (230) of the first group, the first long rod (310) of the second group, and the second long rod (330) of the second group have the same structure, each including: a screw (212), two rod end joints (216), a deep groove ball bearing (215), and a screw clamping mechanism (213); wherein, the inner sides of the two rod end joints (216) are connected to the screw (212) through the screw clamping mechanism (213), and the outer ends of the two rod end joints (216) are equipped with deep groove ball bearings (215), which are fixed inside the rod end joints (216).

6. The active vibration damping device for a high-speed precision seed metering device based on a Watt's linkage according to claim 1, characterized in that, The air pump (760) is fixed to the bottom sill (440).

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