Pilot sequence valve for planter hydraulic system and planter hydraulic system

Abstract

The present application relates to the technical fields of seeding machine hydraulic control, and especially relates to a pilot sequence valve for seeding machine hydraulic system and a seeding machine, the pilot sequence valve for seeding machine hydraulic system comprises a cylinder body, a valve core and an elastic flow control component, the cylinder body has a first cavity, a first hole and a second hole, the valve core is movably arranged in the first cavity in the width direction of the cylinder body, the first hole and the second hole are arranged at intervals in the width direction of the cylinder body, the valve core is arranged with a first ring groove, a second ring groove and a third ring groove at intervals, a first flow path is in communication with the second ring groove, a first throttling hole is connected with the first ring groove and the second ring groove, a second throttling hole is connected with the second ring groove and the third ring groove, the elastic flow control component is arranged in the first hole and the second hole, and the radial dimension of at least part of the first hole and the second hole close to the first cavity gradually decreases along the direction close to the first cavity. The pilot sequence valve for seeding machine hydraulic system is convenient for controlling the flow direction of the flow channel to realize the requirement of different functions.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology for seeders, and in particular to a pilot sequence valve for a hydraulic system of a seeder and a seeder. Background Technology

[0002] With the widespread application of seeders, their technological platforms have gradually advanced, and their auxiliary functions have become increasingly sophisticated, including features such as marking machines and support wheels. Existing technologies require multiple valves and multi-path hydraulic circuits to control the flow path for reversing and closing. Related technologies propose a seeder control hydraulic system and method that uses two sets of directional valves and multiple check valves to control the movement of two components. However, existing directional valves can only open or close the flow path in both directions, not in one direction. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention provide a pilot sequence valve for a seeder hydraulic system, which facilitates flow direction control in the flow channel to meet different functional requirements. The present invention also provides a seeder hydraulic system.

[0005] The pilot sequence valve for the hydraulic system of a seeder according to an embodiment of the present invention is characterized in that it comprises: The cylinder body and valve core are provided. The cylinder body has a first cavity, a first hole, a second hole, and a first flow path. The valve core is movably disposed in the first cavity in the width direction of the cylinder body. The first hole and the second hole are spaced apart in the width direction of the cylinder body. The valve core is provided with a first annular groove, a second annular groove, and a third annular groove arranged sequentially and spaced apart in the width direction of the cylinder body. The first flow path is connected to the second annular groove. The valve core is also provided with a first throttling orifice and a second throttling orifice. The first throttling orifice is connected to the first annular groove and the second annular groove. The second throttling orifice is connected to the second annular groove and the third annular groove. The valve core has a first position and a second position. At least a portion of the radial dimension of the first and second holes near the first cavity gradually decreases along the direction approaching the first cavity. In the first position, the elastic flow control component of the first orifice is in contact with the inner wall of the first orifice to allow the liquid in the first annular groove to flow unidirectionally towards the first orifice; the elastic flow control component of the second orifice is away from the inner wall of the second orifice to allow the third annular groove to communicate bidirectionally with the second orifice. In the second position, the elastic flow control component of the first hole is away from the inner wall of the first hole to enable bidirectional communication between the first hole and the first annular groove, and the elastic flow control component of the second hole is in contact with the inner wall of the second hole to enable the liquid in the third annular groove to flow unidirectionally to the second hole.

[0006] The pilot sequence valve used in the hydraulic system of the seeder in this embodiment of the invention facilitates the control of the flow direction in the flow channel to meet different functional requirements.

[0007] In some embodiments, the valve core is further provided with a first pilot flow path communicating with the first annular groove and a second pilot flow path communicating with the third annular groove at both ends in the cylinder width direction, and the radial dimensions of at least a portion of the first throttling orifice and the second throttling orifice gradually increase in the direction away from the second annular groove.

[0008] In some embodiments, the elastic flow control component includes a slider, an elastic element, a valve ball, and a hollow element. Both the first and second holes include a mounting section, an abutment section, and a connecting section connected in sequence. The radial dimension of the connecting section is smaller than the radial dimension of the mounting section, and the radial dimension of the abutment section gradually decreases towards the connecting section. The hollow component has a through hole, one end of the elastic element is disposed within the through hole, and the other end of the elastic element abuts against the valve ball. The radial dimension of the valve ball is larger than the radial dimension of the connecting section, and the sliding ball is at least partially disposed within the connecting section. The valve core moves in the width direction of the cylinder body to move the slider in the height direction of the cylinder body, so that the end of the valve ball away from the elastic element is adapted to contact the opening or closing connection section.

[0009] In some embodiments, the radial dimension of the ball is 0.75 to 0.95 of the radial dimension of the connecting section, or a size difference thereof, and the size ratio of the ball to the connecting section is 0.75 to 0.95.

[0010] In some embodiments, the first annular groove includes a first annular portion and a second annular portion, one end of the second annular portion away from the second annular groove is connected to the first annular portion, and the size of the first annular portion in the radial direction of the valve core gradually decreases along the direction away from the second annular portion; The third annular groove includes a third annular portion and a fourth annular portion. The end of the fourth annular portion away from the second annular groove is connected to the third annular portion. The size of the third annular portion in the radial direction of the valve core gradually decreases along the direction away from the fourth annular portion.

[0011] In some embodiments, the pilot sequence valve for the seeder hydraulic system further includes an elastic positioning component and a conical ring. The second ring groove contains a conical ring, which is positioned at the center of the valve core axially. The positioning ball extends into the first cavity and contacts the conical ring. The cylinder has a mounting hole located between the first hole and the second hole. One end of the elastic positioning component is installed in the mounting hole to seal it, and the other end of the elastic positioning component extends into the first cavity and contacts the conical ring.

[0012] In some embodiments, the elastic positioning component includes a seal, a positioning ball, and an elastic abutment. One end of the elastic abutment is connected to the seal, and the other end of the elastic abutment is connected to the positioning ball. A conical ring is provided in the second annular groove. The conical ring is located at the center of the valve core axial direction. The positioning ball extends into the first cavity and contacts the conical ring.

[0013] In some embodiments, the tapered annulus includes a first segment and a second segment connected to each other, wherein the first segment gradually increases in size in the radial direction of the valve core away from the first annulus groove, and the second segment gradually decreases in size in the radial direction of the valve core away from the first annulus groove.

[0014] In some embodiments, the pilot sequence valve for the hydraulic system of the seeder further includes: a first check valve and a first flow regulating valve disposed on the cylinder body, the cylinder body having a first flow path communicating with a second annular groove, the first flow path being respectively connected to one end of the first check valve and one end of the first flow regulating valve; A second flow regulating valve and a second check valve are installed on the cylinder body. The cylinder body has a third hole, a fourth hole, and a second flow path. One end of the second flow path is connected to the third hole and the fourth hole respectively, and the other end of the second flow path is connected to one end of the second flow regulating valve and one end of the second check valve respectively.

[0015] The hydraulic system of the seeder of this invention includes: The sequence valve is a pilot-operated sequence valve for the seeder hydraulic system described above; A reversing valve, comprising a first port, a second port, an oil supply port, and an oil return port, wherein the oil supply port is connected to the outlet of the liquid supply assembly, the oil return port is connected to the tractor's liquid tank, the first port is connected to the other end of the second flow regulating valve and the other end of the second check valve respectively, and the second port is connected to the other end of the first check valve and the other end of the first flow regulating valve respectively. A first hydraulic element and a second hydraulic element, wherein one end of the first hydraulic element is connected to the first hole and the other end of the first hydraulic element is connected to the third hole, one end of the second hydraulic element is connected to the second hole and the other end of the second hydraulic element is connected to the fourth hole.

[0016] The hydraulic system of the seeder in the embodiment of the present invention adopts a pilot sequence valve for the hydraulic system of the seeder, which facilitates the control of the flow direction of the flow channel to achieve different functional requirements. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the valve core of the pilot sequence valve for the hydraulic system of a seeder in the first position, according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram showing the valve core of the pilot sequence valve for the hydraulic system of a seeder in the second position according to an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of a pilot sequence valve used in the hydraulic system of a seeder according to an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the valve core in front view according to an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the valve core according to an embodiment of the present invention.

[0022] Figure 6 This is a schematic diagram of the second throttling orifice in an embodiment of the present invention.

[0023] Figure 7 This is one of the schematic diagrams of the hydraulic system of the seeder in an embodiment of the present invention.

[0024] Figure 8 This is the second schematic diagram of the hydraulic system of the seeder in an embodiment of the present invention.

[0025] Figure 9 This is the third schematic diagram of the hydraulic system of the seeder in this embodiment of the invention.

[0026] Figure 10 This is the fourth schematic diagram of the hydraulic system of the seeder in this embodiment of the invention.

[0027] Figure 11 This is the fifth schematic diagram of the hydraulic system of the seeder in this embodiment of the invention.

[0028] Figure 12 This is the sixth schematic diagram of the hydraulic system of the seeder in this embodiment of the invention.

[0029] Figure label: Elastic flow control component 1, slider 11, elastic element 12, valve ball 13, hollow element 14 Cylinder body 2, first chamber 21, first hole 22, second hole 23, mounting section 231, abutment section 232, connecting section 233, first flow path 24, third hole 25, fourth hole 26. Valve core 3, first annular groove 31, first annular portion 311, second annular portion 312, second annular groove 32, third annular groove 33, third annular portion 331, fourth annular portion 332, first throttling orifice 34, second throttling orifice 35, first pilot flow path 36, second pilot flow path 37. Elastic positioning component 4, seal 41, positioning ball 42, elastic abutment component 43. Conical ring 5, first segment 51, second segment 52. First check valve 6, first flow regulating valve 7 Second flow regulating valve 8, second check valve 9 Reversing valve 10, first port 101, second port 102, oil supply port 103, oil return port 104. Sequence valve 20, First hydraulic component 30, second hydraulic component 40. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] The pilot sequence valve 20 for the hydraulic system of the seeder according to an embodiment of the present invention includes: The cylinder body 2 and valve core 3 are provided. The cylinder body 2 has a first cavity 21, a first hole 22 and a second hole 23. The valve core 3 is movably disposed in the first cavity 21 in the width direction of the cylinder body 2. The first hole 22 and the second hole 23 are spaced apart in the width direction of the cylinder body 2. The valve core 3 is provided with a first annular groove 31, a second annular groove 32 and a third annular groove 33 arranged sequentially and spaced apart in the width direction of the cylinder body 2. The first flow path 24 is connected to the second annular groove 32. The valve core 3 is also provided with a first throttling hole 34 and a second throttling hole 35. The first throttling hole 34 is connected to the first annular groove 31 and the second annular groove 32. The second throttling hole 35 is connected to the second annular groove 32 and the third annular groove 33. The elastic flow control component 1 is provided in both the first hole 22 and the second hole 23. At least a portion of the radial dimension of the first hole 22 and the second hole 23 near the first cavity 21 gradually decreases along the direction near the first cavity 21. The valve core 3 has a first position and a second position. In the first position, the elastic flow control component 1 of the first hole 22 is in contact with the inner wall surface of the first hole 22 so that the liquid in the first annular groove 31 flows unidirectionally to the first hole 22, and the elastic flow control component 1 of the second hole 23 is away from the inner wall surface of the second hole 23 so that the third annular groove 33 is bidirectionally connected to the second hole 23. In the second position, the elastic flow control component 1 of the first hole 22 is away from the inner wall of the first hole 22 so that the first hole 22 and the first annular groove 31 are bidirectionally connected, and the elastic flow control component 1 of the second hole 23 is in contact with the inner wall of the second hole 23 so that the liquid in the third annular groove 33 flows unidirectionally to the second hole 23.

[0032] The pilot sequence valve 20 used in the hydraulic system of the seeder in this embodiment of the invention facilitates the control of the flow direction in the flow channel to meet the needs of different functions.

[0033] Specifically, such as Figure 1-6 As shown. The cylinder body 2 has a first cavity 21 for mounting the valve core 3. For ease of description, the width direction of the cylinder body 2 is the left-right direction, and the height direction of the cylinder body 2 is the up-down direction. The first hole 22 and the second hole 23 extend vertically and are spaced apart horizontally. The lower end of the first hole 22 is connected to the first cavity 21, and the lower end of the second hole 23 is connected to the first cavity 21. The valve core 3 is provided with a first annular groove 31, a second annular groove 32 and a third annular groove 33 from left to right. The second annular groove 32 is located between the first annular groove 31 and the third annular groove 33. The first throttling orifice 34 connects the first annular groove 31 and the second annular groove 32. The second throttling orifice 35 connects the second annular groove 32 and the third annular groove 33. The second annular groove 32 is connected to the first annular groove 31 through the first throttling orifice 34 and to the third annular groove 33 through the second throttling orifice 35.

[0034] Furthermore, a pressurized liquid is introduced into the second annular groove 32, and then flows into the first annular groove 31 and the third annular groove 33 through the first throttling orifice 34 and the second throttling orifice 35. When the valve core 3 is located at the leftmost position, i.e. the first position, the lower end of the elastic flow control component 1 of the first hole 22 contacts the inner wall surface of the first hole 22 to form a one-way valve structure, thereby allowing the liquid in the first annular groove 31 to flow unidirectionally to the first hole 22. That is, the liquid in the first annular groove 31 can flow unidirectionally to the first hole 22, but the liquid in the first hole 22 cannot flow into the first annular groove 31. At this time, the lower end of the elastic flow control component 1 of the second hole 23 is away from the inner wall surface of the second hole 23, so that the second hole 23 and the third annular groove 33 are bidirectionally connected. That is, the liquid in the second hole 23 can flow into the third annular groove 33, or the liquid in the third annular groove 33 can flow into the second hole 23.

[0035] When the valve core 3 is located at the rightmost position, i.e., the second position, the lower end of the elastic flow control component 1 of the first hole 22 moves away from the inner wall of the first hole 22, thereby enabling the first annular groove 31 to communicate bidirectionally with the first hole 22. That is, the liquid in the first annular groove 31 can flow to the first hole 22, and the liquid in the first hole 22 can also flow into the first annular groove 31. At this time, the lower end of the elastic flow control component 1 of the second hole 23 moves down to contact the inner wall of the second hole 23 to form a one-way valve structure, thereby enabling the liquid in the third annular groove 33 to flow unidirectionally to the second hole 23, and the liquid in the second hole 23 cannot flow into the third annular groove 33.

[0036] The pilot sequence valve 20 of the hydraulic system of the seeder in this embodiment of the invention controls the unidirectional and bidirectional flow of the first hole 22 and the first chamber 21 and the second hole 23 and the first chamber 21 by moving the valve core 3 left and right, or switching between the first position and the second position. This is to meet the different action requirements of the seeder, without the need to set up multiple valves and multiple sets of oil circuits or oil pipes, reducing the volume and the probability of valve failure.

[0037] The flow control function is fully integrated into the cylinder body 2, and the first hole 22 and the second hole 23 are directly connected to the cavity of the first chamber 21, reducing the number of external transition oil pipes and threaded connection points. This eliminates the risk of loosening and oil leakage caused by pipeline vibration, and also avoids chain failures caused by multiple sets of external valve cores 3 due to jamming or spring failure. At the same time, the contact / separation action of the elastic flow control component 1 within the tapered orifice wall is simple and reliable. Compared with the traditional complex slide valve structure, the moving parts experience less wear, have stronger anti-contamination capabilities, and improve operational stability and safety.

[0038] By uniformly controlling the two flow channels through the three-position valve core, pressure and flow deviations caused by individual differences when multiple valves are connected in parallel are eliminated. This simplifies the debugging of the seeder's hydraulic system, and due to the reduction in the number of components, assembly time and material costs are also reduced. It achieves significant economic benefits while ensuring high reliability. At the same time, reducing the types and number of valves will reduce the overall size and weight of the structure, thus lowering costs.

[0039] In some embodiments, the valve core 3 is further provided with a first pilot flow path 36 communicating with the first annular groove 31 and a second pilot flow path 37 communicating with the third annular groove 33 at both ends in the width direction of the cylinder body 2. The radial dimensions of at least a portion of the first throttling orifice 34 and the second throttling orifice 35 gradually increase in the direction away from the second annular groove 32. The valve core 3 is further provided with a first pilot flow path 36 communicating with the first annular groove 31 and a second pilot flow path 37 communicating with the third annular groove 33 at both ends in the width direction of the cylinder body 2. The radial dimensions of at least a portion of the first throttling orifice 34 and the second throttling orifice 35 gradually increase in the direction away from the second annular groove 32, so that the pressure of the liquid flowing from the second annular groove 32 to the third annular groove 33 or the first annular groove 31 decreases.

[0040] Specifically, such as Figure 1-6 As shown. The first pilot flow path 36 and the second pilot flow path 37 are arranged at intervals relative to each other in the left-right direction of the valve core 3, and the first pilot flow path 36 is adapted to pass the liquid in the first annular groove 31 into the area on the left side of the first chamber 21 that is not filled by the valve core 3. The second pilot flow path 37 is adapted to pass the liquid in the third annular groove 33 through the area on the right side of the first chamber 21 that is not filled by the valve core 3.

[0041] When valve core 3 is in the first position, it is located on the left side of the first chamber 21. At this time, the first hole 22 is in a one-way valve state, and the second hole 23 is in a bidirectional flow state. The pressure oil output by the oil pump is output to the second annular groove 32, and the pressure oil flows out of the cylinder body 2 from the first hole 22 and the second hole 23. When it is necessary to move valve core 3 to the second position, it should be noted that in the actual installation structure, the upper end of the first hole 22 is connected to the large chamber of the left arm cylinder, and the upper end of the second hole 23 is connected to the large chamber of the right arm cylinder. When valve core 3 is in the first position, the oil pump output can be output to the large chambers of the left and right arm cylinders through the first hole 22 and the second hole 23 to complete the extension of the left and right arm cylinders. The small chambers of the left and right arm cylinders are connected to the liquid tank through the oil circuit.

[0042] Adjust the output end of the oil pump to connect the output end to the small chambers of the left and right arm cylinders. The second annular groove 32 is connected to the liquid tank through the oil circuit to return the liquid. At this time, the right arm cylinder retracts. Since the first hole 22 of the left arm cylinder is in the one-way valve state, the oil in the first hole 22 cannot flow back to the first chamber 21, nor can it flow back to the liquid tank. At this time, the left arm cylinder remains in the extended state.

[0043] The oil pump output is switched again to connect to the second annular groove 32 of the first chamber 21. The liquid tank is connected to the small chambers of the left and right arm cylinders respectively. At this time, the left arm cylinder remains in the extended state, and the right arm cylinder switches from the retracted state to the extended state. At this time, the oil in the third annular groove 33 flows to the second hole 23 and finally flows to the large chamber of the right arm cylinder. Under the action of the second throttling hole 35, the oil pressure in the third annular groove 33 is less than the oil pressure in the first annular groove 31. The second pilot flow path 37 is suitable for guiding the liquid in the third annular groove 33 through the area on the right side of the first chamber 21 that is not filled by the valve core 3, thereby causing the oil pressure on the right side of the first chamber 21 to be less than the oil pressure on the left side of the first chamber 21. At this time, the pressure on the left end face of the valve core 3 is greater than the pressure on the right end face, and the valve core 3 moves to the right to the second position. Then the first hole 22 switches to a bidirectional flow state, and the second hole 23 switches to a one-way valve state. At this time, the valve core 3 moves to the right.

[0044] Then adjust the output end of the oil pump to connect the output end with the small chambers of the left and right arm cylinders. The second annular groove 32 is connected to the liquid tank through the oil circuit to return the liquid. At this time, the left arm cylinder retracts. Because the second hole 23 of the right arm cylinder is in the one-way valve state, the oil in the second hole 23 cannot flow back to the third annular groove 33 of the first chamber 21, nor can it flow back to the liquid tank. At this time, the right arm cylinder remains in the extended state. The oil pump output is switched again to connect with the second annular groove 32 of the first chamber 21. The liquid tank is connected to the small chambers of the left and right arm cylinders respectively. At this time, the right arm cylinder remains in the extended state, and the left arm cylinder switches from the retracted state to the extended state. At this time, the oil in the first annular groove 31 flows to the first hole 22 and finally flows to the large chamber of the left arm cylinder. Under the action of the first throttling hole 34, the oil pressure in the first annular groove 31 is less than the oil pressure in the third annular groove 33. The first pilot flow path 36 is suitable for passing the liquid in the first annular groove 31 into the area on the left side of the first chamber 21 that is not filled by the valve core 3, which causes the oil pressure on the right side of the first chamber 21 to be greater than the oil pressure on the left side of the first chamber 21. At this time, the pressure on the left end face of the valve core 3 is less than the pressure on the right end face, and the valve core 3 moves to the left to the first position. Then the second hole 23 switches to a bidirectional flow state, and the first hole 22 switches to a one-way valve state. At this time, the valve core 3 moves to the left, and different functional requirements are achieved in sequence through the switching of the oil circuit output and input states.

[0045] The pilot sequence valve 20 used in the hydraulic system of the seeder in this embodiment of the invention integrates the complex flow logic that traditionally requires multiple independent directional valves 10 and check valves in parallel into a single valve body through the ingenious cooperation of three annular grooves on the valve core 3 and the double elastic flow control component 1. This not only significantly reduces the installation volume and simplifies the external oil circuit layout, but also reduces the number of pipe joints and threaded connection points. It reduces the probability of loosening and oil leakage caused by field vibration, and improves the overall sealing durability and operational reliability of the hydraulic system. It eliminates the need to rely on solenoid valves and complex controllers. Different functional requirements are achieved sequentially by switching the state of oil circuit output and input. The oil pump only needs to perform a simple oil supply and return switch, and the valve core 3 will autonomously complete the left and right displacement logic judgment based on the real-time pressure difference between the two end faces, switching between bidirectional flow and unidirectional locking states, thereby realizing the sequential control of the extension-holding-alternating action of the left and right arm cylinders of the seeder. This fully hydraulic self-feedback mechanism not only has a direct response and strong action synchronization, but also has a strong anti-electromagnetic interference capability and is suitable for harsh field conditions.

[0046] In some embodiments, the elastic flow control component 1 includes a slider 11, an elastic element 12, a valve ball 13, and a hollow element 14. The first hole 22 and the second hole 23 each include a mounting section 231, an abutment section 232, and a connecting section 233 connected in sequence. The radial dimension of the connecting section 233 is smaller than the radial dimension of the mounting section 231, and the radial dimension of the abutment section 232 gradually decreases along the direction approaching the connecting section 233. The hollow component 14 has a through hole, one end of the elastic component 12 is disposed in the through hole, and the other end of the elastic component 12 abuts against the valve ball 13. The radial dimension of the valve ball 13 is larger than the radial dimension of the connecting section 233. The sliding ball 11 is at least partially disposed in the connecting section 233. The valve core 3 moves in the width direction of the cylinder body 2 so that the slider 11 moves in the height direction of the cylinder body 2, so that the end of the valve ball 13 away from the elastic member 12 is suitable to contact the opening or closing connection section 233.

[0047] The sliding ball 11 can be set in the connecting section 233. A hollow part 14 is installed in the mounting section 231. The lower end of the mounting section 231 is connected to the upper end of the abutting section 232. The lower end of the abutting section 232 is connected to the upper end of the connecting section 233. The lower end of the connecting section 233 is connected to the first cavity 21.

[0048] The abutting section 232 is a conical surface with a gradually decreasing radial dimension, that is, the radial dimension of at least part of the first hole 22 and the second hole 23 gradually decreases towards the first cavity 21, that is, the radial dimension of the first hole 22 and the second hole 23 gradually decreases from top to bottom.

[0049] For ease of description, the mounting section 231 of the first hole 22 is referred to as the first mounting section 231, and the mounting section 231 of the second hole 23 is referred to as the second mounting section 231. The abutting section 232 of the first hole 22 is the first abutting section 232, the abutting section 232 of the second hole 23 is the second abutting section 232, the connecting section 233 of the second hole 23 is the second connecting section 233, and the connecting section 233 of the first hole 22 is the first connecting section 233.

[0050] Specifically, such as Figure 1-6 As shown. The hollow component 14 has a hollow structure inside, i.e., it has a through hole. An elastic component 12 is installed inside the hollow component 14, with its upper end either touching or abutting against the upper end of the elastic component 12. The lower end of the elastic component 12 abuts against the valve ball 13. The valve ball 13 moves downward so that its outer peripheral surface contacts the inner wall surface of the abutting section 232, thereby causing the liquid in the first cavity 21 to flow unidirectionally to the first hole 22 or the second hole 23. For example, in the first position, the valve ball 13 in the first hole 22 moves downward and contacts the first abutment section 232, then the first hole 22 forms a one-way valve structure, that is, the first hole 22 is in a one-way valve state at this time. The slider 11 of the first hole 22 extends at least partially out of the first connecting section 233, then the lower end of the slider 11 of the first hole 22 contacts the outer peripheral surface of the first annular groove 31, and the liquid in the first annular groove 31 can flow unidirectionally to the first hole 22, and then the liquid in the first hole 22 cannot flow to the first annular groove 31. The valve ball 13 of the second hole 23 moves upward so that the valve ball 13 disengages from the inner wall surface of the second abutment section 232. At this time, the second hole 23 is in a bidirectional flow state, and the liquid in the second hole 23 can flow to the third annular groove 33, and the liquid in the third annular groove 33 can also flow to the second hole 23.

[0051] For example, in the second position, the valve ball 13 in the second hole 23 moves downward and contacts the second abutment section 232, and then the second hole 23 forms a one-way valve structure, that is, the second hole 23 is in a one-way valve state at this time. The slider 11 of the second hole 23 extends at least partially out of the second connecting section 233, and then the lower end of the slider 11 of the second hole 23 contacts the outer peripheral surface of the third annular groove 33. The liquid in the third annular groove 33 can flow unidirectionally to the second hole 23, and then the liquid in the second hole 23 cannot flow to the third annular groove 33. The slider 11 of the first hole 22 moves upward to move the valve ball 13 of the first hole 22 upward to disengage the valve ball 13 from the inner wall surface of the first abutment section 232. At this time, the first hole 22 is in a bidirectional flow state, and the liquid in the first hole 22 can flow to the first annular groove 31, and the liquid in the first annular groove 31 can also flow to the first hole 22.

[0052] In this embodiment of the invention, the valve ball 13 and the abutment section 232 constitute a typical line-contact hard seal structure. Compared to traditional planar or spool valve gap seals, this ball-cone fit, under the action of spring preload and hydraulic back pressure, can generate extremely high contact stress. When the valve core 3 is in the first or second position, the valve ball 13 on the corresponding side is pressed tightly against the conical surface under the spring force, which can cut off the passage between the first cavity 21 and the corresponding channel. Therefore, whether the left arm remains extended or the right arm is locked, the oil in the large cavity of the cylinder has no backflow channel, fundamentally eliminating the phenomenon of soft leg or position drift caused by internal leakage, and ensuring the absolute rigidity and positional accuracy of the seeder's actions.

[0053] Slight horizontal movement of valve core 3 is immediately converted into vertical movement via slider 11 within connecting section 233, directly opening or releasing valve ball 13. This changes the contact or non-contact state between valve ball 13 and abutment section 232. The linkage of slider 11 ensures that the opening and closing timing of valve ball 13 is perfectly synchronized with the position of valve core 3, ensuring no lag in flow channel switching. This reduces hydraulic fluctuations during hydraulic switching, resulting in clean and crisp hydraulic action switching without unexpected instantaneous "double-open" or "double-close" pressure buildup caused by signal transmission delays.

[0054] Furthermore, during the movement and rotation of the ball 11, the contact between it and the conical surface of the contact section 232 is an instantaneous point / line contact, and the spherical surface has a "scraping effect." Even if tiny particles are mixed in the oil, the rolling ball can crush or push the contaminants to the edge recesses, unlike precision slide valves (clearance fit) where impurities get stuck in the fit clearance, causing the valve core 3 to "stick up" or the valve ball 13 to fail to close properly. This greatly improves the long-term reliability of agricultural machinery operating under conditions of high dust and limited oil filtration precision.

[0055] In some embodiments, the radial dimension of the sliding ball 11 is 0.75 to 0.95 of the radial dimension of the connecting section 233, and the size ratio of the valve ball 13 to the mounting section 231 is 0.6 to 0.9.

[0056] Specifically, such as Figure 1-6 As shown. The radial dimension of the slider 11 is 0.75 to 0.95 of the radial dimension of the connecting segment 233.

[0057] In this structure, the slider 11 acts as a transmission mechanism that converts the horizontal displacement of the valve core 3 into vertical thrust. Setting the diameter of the slider 11 to 0.75~0.95 of the orifice diameter of the connecting section 233 means that the slider 11 has only a small movement clearance within the orifice. This limits and guides the vertical movement of the slider 11, ensuring that it can only perform strict reciprocating translational motion along the axis within the connecting section 233, preventing significant radial offset or tilting. When the valve core 3 moves horizontally, the slider 11 can vertically and centrally push the valve ball 13, ensuring that the point of force application is approximately located at the center of the valve ball 13. This fundamentally avoids jamming or lateral force caused by the slider 11's deflection, improving the rigidity and operational certainty of the transmission chain and ensuring immediate response during flow channel switching.

[0058] Unlike the sliding ball 11, the valve ball 13 performs the sealing and shut-off function. Its larger radial clearance allows for slight radial floating within the orifice under the influence of spring force and hydraulic pressure. When the valve ball 13 is pushed towards the conical surface of the contact section 232, this floating characteristic enables it to automatically find the optimal sealing line. Even if the valve ball 13 itself has slight manufacturing roundness errors or coaxiality deviations in the installation section 231, the valve ball 13 can compensate through translation to ensure line contact between its spherical and conical surfaces, thereby achieving an absolutely reliable zero-leakage sealing effect. The larger radial clearance also facilitates the return of liquid to the oil tank or output to the cylinder through the first hole 22 or the second hole 23. When the valve ball 13 is in the open state, the oil can quickly bypass the ball, effectively avoiding pressure loss due to excessive throttling and ensuring the rapid action and strong thrust of the seeder cylinder. The large gap between the valve ball 13 and the mounting section 231 provides flow space for tiny metal powders or impurities in the oil. Hard particles are not easily wedged at this point, and are easily carried out by the oil flow, reducing the probability of blockage.

[0059] In some embodiments, the first annular groove 31 includes a first annular portion 311 and a second annular portion 312. One end of the second annular portion 312 away from the second annular groove 32 communicates with the first annular portion 311. The size of the first annular portion 311 in the radial direction of the valve core 3 gradually decreases along the direction away from the second annular portion 312. The third annular groove 33 includes a third annular portion 331 and a fourth annular portion 332. The end of the fourth annular portion 332 away from the second annular groove 32 is connected to the third annular portion 331. The size of the third annular portion 331 in the radial direction of the valve core 3 gradually decreases in the direction away from the fourth annular portion 332.

[0060] Specifically, such as Figure 1-6 As shown. The left end of the first ring 311 is connected to the first pilot flow path 36, and the right end is connected to the second ring 312. The radial dimension of the first ring in the valve core 3 gradually decreases from right to left, that is, the radial dimension of the valve core 3 portion corresponding to the first ring 311 gradually decreases from left to right. The right end of the third ring 331 is connected to the second pilot flow path 37, and the right end of the fourth ring 332 is connected to the left end of the third ring 331. The radial dimension of the third ring in the valve core 3 gradually decreases from left to right, that is, the radial dimension of the valve core 3 portion corresponding to the third ring 331 gradually increases from left to right. Furthermore, when the valve core 3 moves from the first position to the second position, the ball 11 of the first hole 22 moves downward under the action of the first ring portion 311 and the elastic element 12 of the first hole 22, while the ball 11 of the second hole 23 moves upward under the action of the third ring portion 331. When the valve core 3 moves from the second position to the first position, the ball 11 of the second hole 23 moves downward under the action of the third ring portion 331 and the elastic element 12 of the second hole 23, while the ball 11 of the first hole 22 moves upward under the action of the first ring portion 311.

[0061] Whether the valve core 3 moves from the first position to the second position or back from the second position to the first position, there is an active pushing force provided by the conical surface of the third annular groove 33 or the first annular groove 31 in both directions. That is, one conical surface actively pushes up the sliding ball 11, while the other conical surface, in conjunction with the spring, causes the sliding ball 11 to descend slowly. This ensures the absolute reliability of the reversing action of the seeder under extreme working conditions such as low temperature and high dust. It ensures that the elastic flow control components 1 of the first hole 22 and the second hole 23 are always in an alternating switching state, without any brief fully open or fully closed window period caused by action delay. Especially for the hydraulic system of the seeder's double arm, this rigid synchronous linkage prevents oil leakage accidents caused by high pressure oil simultaneously entering the first hole 22 and the second hole 23 from the second annular groove 32 at the moment of switching, or by the simultaneous depressurization of the large chambers of the two cylinders to the oil tank, thus enhancing the safety and pressure stability of the system during the action switching transition phase.

[0062] In some embodiments, the pilot sequence valve 20 of the seeder hydraulic system further includes an elastic positioning component 4 and a conical ring 5. The conical ring 5 is provided in the second ring groove 32 and is located at the center of the valve core 3 in the axial direction. The positioning ball 42 extends into the first cavity 21 and contacts the conical ring 5. The cylinder body 2 has a mounting hole located between the first hole 22 and the second hole 23. One end of the elastic positioning component 4 is installed in the mounting hole to seal the mounting hole, and the other end of the elastic positioning component 4 extends into the first cavity 21 and contacts the conical ring 5.

[0063] Specifically, such as Figure 1-6 As shown. The conical ring 5 is positioned at the axial center of the valve core 3, that is, at the middle position in the left-right direction of the valve core 3. The upper end of the elastic positioning component 4 is installed in the mounting hole, and the lower end of the elastic positioning component 4 extends into the first cavity 21 and contacts the outer periphery of the conical ring 5. The elastic positioning component 4 has a certain elasticity, which, in conjunction with the conical ring 5 on the valve core 3, prevents the valve core 3 from getting stuck in the middle position due to insufficient hydraulic pressure or friction, ensuring the smooth switching of the valve core 3 between the first and second positions. During the operation of agricultural machinery such as seeders, the machine body will be continuously subjected to impacts such as uneven ground and seed bed vibration. The mechanical locking / positioning mechanism formed by the elastic positioning component 4 and the conical ring 5 can reliably maintain the position of the main valve core 3, preventing the valve core 3 from accidentally changing direction due to vibration, thereby avoiding malfunction of the hydraulic cylinder and ensuring consistent sowing depth and operational accuracy.

[0064] Furthermore, the elastic positioning component 4 includes a seal 41, a positioning ball 42, and an elastic abutment 43. One end of the elastic abutment 43 is connected to the seal 41, and the other end of the elastic abutment 43 is connected to the positioning ball 42. A conical ring 5 is provided in the second annular groove 32. The conical ring 5 is located at the center of the valve core 3 in the axial direction. The positioning ball 42 extends into the first cavity 21 and contacts the conical ring 5.

[0065] The seal 41 is installed in the mounting hole, and its lower end is connected to or abuts against the upper end of the elastic abutment 43. The lower end of the elastic abutment 43 is connected to one end of the positioning ball 42. The other end of the positioning ball 42 is in contact with the conical ring 5. The conical ring 5 is located at the axial center of the valve core 3 in the left-right direction. When the main valve core 3 moves from the first position to the second position or from the second position to the first position, the positioning ball 42 rises and then falls.

[0066] This implementation sets the highest point of the conical ring 5 at the axial center of the valve core 3, and the positioning ball 42 is in its maximum compression state when in the center position. Once the main valve core 3 deviates from the center, the positioning ball 42 will slide to one side of the inclined surface of the conical ring 5, and the elastic force will push the main valve core 3 to continue moving to the left or right, thereby preventing the valve core 3 from getting stuck in the middle position due to insufficient hydraulic pressure or friction, ensuring the stability of the main valve core 3 when switching between the first and second positions, and improving the certainty of system operation. During the operation of agricultural machinery such as seeders, the machine body will be continuously subjected to impacts such as uneven ground and vibration. The mechanical locking / positioning mechanism formed by the elastic abutment 43 and the conical ring 5 can reliably maintain the position of the main valve core 3, prevent the valve core 3 from accidentally changing direction due to vibration, thereby avoiding malfunction of the hydraulic cylinder, ensuring consistent sowing depth and operational accuracy. The elastic positioning component 4 is directly embedded in the mounting hole of the cylinder body 2 and cooperates with the conical ring 5 in the second ring groove 32 of the main valve core 3, without occupying additional external space or adding an independent positioning device. To maintain the overall compactness of the hydraulic control components, making it easy to arrange within the limited installation space of the seeder.

[0067] In some embodiments, the conical ring 5 includes a first segment 51 and a second segment 52 that are interconnected. The first segment 51 gradually increases in size in the radial direction away from the first annular groove 31, and the second segment 52 gradually decreases in size in the radial direction away from the first annular groove 31. The first segment 51 and the second segment 52 are integrally formed. The first segment 51 gradually increases in size in the radial direction of the valve core 3 from left to right, and the second segment 52 gradually decreases in size in the radial direction of the valve core 3 from left to right.

[0068] In this embodiment, the conical ring 5 first decreases and then increases in size along the axial direction of the main valve core 3. The conical ring 5's axial profile—meaning it is thinner in the middle and thicker at both ends, or highest in the middle—cooperates with the positioning ball 42. When the main valve core 3 moves to the first or second position, the positioning ball 42 falls into the "recessed areas" on both sides of the conical ring 5, and the pre-pressure of the elastic abutment member 43 stabilizes the main valve core 3 at its end position. This prevents the valve core 3 from drifting due to vibration or pressure fluctuations, ensuring reliable switching. When the main valve core 3 switches between the second and first positions, the positioning ball 42 first rises along the slope of the conical ring 5, compressing the elastic abutment member 43 and storing energy. After passing the highest point of the axial center, it descends along the other slope to release energy, pushing the valve core 3 to accelerate towards the other end. This rise-then-fall motion achieves mechanical jump assistance, helping the valve core 3 complete the switching quickly, reducing the dwell time in the middle position, and improving the system response speed.

[0069] In some embodiments, the pilot sequence valve 20 for the hydraulic system of the seeder further includes: a first check valve 6 and a first flow regulating valve 7 disposed on the cylinder body 2. The cylinder body 2 is also provided with a first flow path 24 connected to the second annular groove 32. The first flow path 24 is respectively connected to one end of the first check valve 6 and one end of the first flow regulating valve 7. The cylinder body 2 is provided with a second flow regulating valve 8 and a second check valve 9. The cylinder body 2 has a third hole 25, a fourth hole 26 and a second flow path. One end of the second flow path is connected to the third hole 25 and the fourth hole 26 respectively, and the other end of the second flow path is connected to one end of the second flow regulating valve 8 and one end of the second check valve 9 respectively.

[0070] Specifically, such as Figure 1-6 As shown, the cylinder body 2 is provided with a first flow path 24, which is connected to the second annular groove 32. The other end of the first flow path 24 is connected to a first check valve 6 and a second check valve 9. Oil can then be delivered to the first flow path 24 through the first check valve 6 and the first flow regulating valve 7. The oil in the first chamber 21 can also flow back to the oil tank through the first flow regulating valve 7. The amount of oil flowing back can be controlled by the first flow regulating valve 7 to control the cylinder's contraction speed. Simultaneously, when the first flow regulating valve 7 is closed, the first check valve 6 prevents the liquid in the first flow path 24 from flowing back to the oil tank, thus keeping the cylinder in an extended state to achieve the corresponding functional requirements.

[0071] A second flow regulating valve 8 and a second check valve 9 are installed on the cylinder body 2. The cylinder body 2 has a third hole 25, a fourth hole 26, and a second flow path. One end of the second flow path is connected to the third hole 25 and the fourth hole 26 respectively, and the other end of the second flow path is connected to one end of the second flow regulating valve 8 and one end of the second check valve 9 respectively. Oil can be delivered to the second flow path through the second check valve 9 and the second flow regulating valve 8, and can also flow back to the oil tank through the second flow regulating valve 8. The amount of oil flowing back is controlled by the second flow regulating valve 8 to control the contraction speed of the cylinder.

[0072] At the same time, when the second flow regulating valve 8 is closed, the second check valve 9 can prevent the liquid in the second flow path from flowing back into the liquid tank, so that the oil cylinder remains in the extended state to achieve the corresponding functional requirements.

[0073] The cylinder body 2 may also have a fifth hole, one end of which is connected to the inlet of the second flow regulating valve 8 and the second check valve 9 respectively, and the other end of which is connected to the reversing valve 10, thereby eliminating the need to connect the second flow regulating valve 8 and the second check valve 9 to external components respectively, thus improving the system integration.

[0074] The hydraulic system of the seeder of this invention includes: Sequence valve 20, sequence valve 20 is a pilot sequence valve 20 for the seeder hydraulic system described above; The reversing valve 10 includes a first port 101, a second port 102, an oil supply port 103, and an oil return port 104. The oil supply port 103 is connected to the outlet of the liquid supply component, and the oil return port 104 is connected to the tractor's liquid tank. The first port 101 is connected to the other end of the second flow regulating valve 8 and the other end of the second check valve 9, respectively. The second port 102 is connected to the other end of the first check valve 6 and the other end of the first flow regulating valve 7, respectively. A first hydraulic element 30 and a second hydraulic element 40 are connected. One end of the first hydraulic element 30 is connected to the first hole 22, and the other end of the first hydraulic element 30 is connected to the third hole 25. One end of the second hydraulic element 40 is connected to the second hole 23, and the other end of the second hydraulic element 40 is connected to the fourth hole 26.

[0075] For ease of description, the first hydraulic component 30 can be the left arm cylinder, and the second hydraulic component 40 can be the right arm cylinder. The cylinder body 2 has a fifth hole, one end of which is connected to the inlet of the second flow regulating valve 8 and the second check valve 9 respectively, and the other end of which is connected to the reversing valve 10.

[0076] Specifically, such as Figure 1-6 As shown. In the first state, the oil supply port 103 is connected to the second port 102, and the oil return port 104 is connected to the first port 101. At this time, both the left arm cylinder and the right arm cylinder are in the extended state. In the second state, the oil supply port 103 is connected to the first port 101, and the oil return port 104 is connected to the second port 102. At least one of the left arm cylinder and the right arm cylinder is in the retracted state.

[0077] The reversing valve 10 also has a closed state, in which the first port 101, the second port 102, the oil supply port 103 and the oil return port 104 are not connected to each other, so that the seeder can be stopped.

[0078] The following describes the operation of the hydraulic system of this seeder. Step 1: As Figure 7 As shown, the reversing valve 10 is in the closed state, that is, the oil supply port 103, the second port 102, the oil return port 104, and the first port 101 are not connected to each other. At this time, the left arm cylinder and the right arm cylinder are also in the fully retracted state, and the whole machine is on standby and remains stationary.

[0079] Step 2: As Figure 8 As shown, when the reversing valve 10 is switched to the first state, the oil supply port 103 is connected to the second port 102, and the oil return port 104 is connected to the first port 101. Pressure oil is output from its outlet, passes through the second port 102 to the sequence valve 20, and after passing through the first flow valve, reaches the valve core 3. The valve core 3 is in the first position, and the pressure oil directly flows to the large chambers of the left and right arm cylinders, causing both cylinders to extend outwards simultaneously. The oil in the small chambers of the left and right arm cylinders flows back to the liquid tank through the second flow regulating valve 8, the first port 101, and the oil return port 104. After the left and right arm cylinders have extended to their designated positions, the reversing valve 10 is switched to the closed position, and both cylinders are in a holding state. This state is the transport state; the entire machine is raised, and the seeder's overall mechanism is in a retracted state, minimizing its size for easy storage and transport.

[0080] Step 3: As Figure 9 As shown, switch the reversing valve 10 to the second state, connecting the oil supply port 103 to the first port 101 and the oil return port 104 to the second port 102. Pressurized oil is output from the outlet to the second flow regulating valve 8 and the second check valve 9. After passing through the second flow valve, it reaches the small chamber of the left arm cylinder and the small chamber of the right arm cylinder. At this time, the main valve core 3 is in the first position. The oil return from the large chamber of the left arm cylinder cannot flow from the first hole 22 to the second annular groove 32 or back to the liquid tank, so the left arm cylinder remains stationary. The oil from the large chamber of the left arm cylinder passes through the second hole 23 and the first flow valve, then through the reversing valve 10, and returns to the liquid tank. After the lifting cylinder and the right arm cylinder have reached their positions, switch the reversing valve 10 to the closed position. The lifting cylinder, left arm cylinder, and right arm cylinder are all in the holding state. This is the operating state; the entire machine is lowered, the right arm cylinder is also lowered, and the left arm cylinder is extended. Maintaining this state is sufficient for operation.

[0081] Step 4: As Figure 10 As shown, at this time, the directional valve 10 switches to the first state, and the pressurized oil is output from the oil supply port 103, passing through the first flow valve and reaching the valve core 3. Since the left arm cylinder is already in the raised position and the right arm cylinder extends, the oil in the third annular groove 33 is output into the second hole 23. Under the action of the second throttle hole 35, the pressure on the left side of the valve core 3 is higher than that on the right side, and the main valve core 3 switches from the first position to the second position. The pressurized oil passes through the main valve core 3 and then to the large chamber of the right arm cylinder, and the right arm cylinder extends outward and gradually rises. After the lifting cylinder and the right arm cylinder have reached their positions, the directional valve 10 is switched to the closed state, and all cylinders are in the holding state. This state is the non-operating state, and all cylinders are extended and maintain this state.

[0082] Step 5: As Figure 11 As shown, at this time, the reversing valve 10 switches to the second state. Pressure oil is output from the oil supply port 103 to the second flow regulating valve 8 and the second check valve 9 of the sequence valve 20. After passing through the second flow valve, it flows to the small chamber of the left arm cylinder and then to the small chamber of the right arm cylinder. At this time, the valve core 3 is in the second position. The return oil from the large chamber of the right arm cylinder is locked by the check valve structure of the second hole 23 and remains stationary. The large chamber of the left arm cylinder, after passing through the main valve core 3 and the first flow valve, flows from the third port to the reversing valve 10, and then returns to the liquid tank. After the left arm cylinder retracts to its designated position, the reversing valve 10 is switched to the closed position, and both the left and right arm cylinders are in a holding state. This is the operating state. When the entire machine lowers, the left arm cylinder also lowers, and the right arm cylinder rises. Maintaining this state allows for operation.

[0083] Step 6: As Figure 12 As shown, at this time, the directional valve 10 switches to the first state, and the pressurized oil is output from the oil supply port 103, passes through the first flow valve, and reaches the valve core 3. Because the right arm cylinder is already in the raised position, the left arm cylinder extends, and the oil in the first annular groove 31 flows to the first hole 22. Under the action of the first throttle hole 34, the pressure on the right side of the main valve core 3 is higher than that on the left side, and the main valve core 3 switches to the first position. After the left arm cylinder has moved to its position, the directional valve 10 is switched to the closed state. This state is the non-operating state, and all cylinders are extended and maintain this state.

[0084] The process repeats from step one to step six to switch between the seeder's operating and transport modes.

[0085] The hydraulic system of the seeder in the embodiment of the present invention adopts a pilot sequence valve 20 for the seeder hydraulic system, which facilitates the control of the flow direction of the flow channel to meet the needs of different functions. In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0087] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0088] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0089] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0090] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A pilot sequence valve for a seeder hydraulic system, characterized in that, include: The cylinder body and valve core are provided. The cylinder body has a first cavity, a first hole and a second hole. The valve core is movably disposed in the first cavity in the width direction of the cylinder body. The first hole and the second hole are spaced apart in the width direction of the cylinder body. The valve core is provided with a first annular groove, a second annular groove and a third annular groove arranged sequentially and spaced apart in the width direction of the cylinder body. The first flow path is connected to the second annular groove. The valve core is also provided with a first throttling orifice and a second throttling orifice. The first throttling orifice is connected to the first annular groove and the second annular groove. The second throttling orifice is connected to the second annular groove and the third annular groove. The valve core has a first position and a second position. At least a portion of the radial dimension of the first and second holes near the first cavity gradually decreases along the direction approaching the first cavity. In the first position, the elastic flow control component of the first orifice is in contact with the inner wall of the first orifice to allow the liquid in the first annular groove to flow unidirectionally towards the first orifice; the elastic flow control component of the second orifice is away from the inner wall of the second orifice to allow the third annular groove to communicate bidirectionally with the second orifice. In the second position, the elastic flow control component of the first hole is away from the inner wall of the first hole to enable bidirectional communication between the first hole and the first annular groove, and the elastic flow control component of the second hole is in contact with the inner wall of the second hole to enable the liquid in the third annular groove to flow unidirectionally to the second hole.

2. The pilot sequence valve for the hydraulic system of a seeder according to claim 1, characterized in that, The valve core is provided with a first pilot flow path communicating with the first annular groove and a second pilot flow path communicating with the third annular groove at both ends in the cylinder width direction. The radial dimensions of at least part of the first throttling orifice and the second throttling orifice gradually increase in the direction away from the second annular groove.

3. The pilot sequence valve for the hydraulic system of a seeder according to claim 1, characterized in that, The elastic flow control component includes a slider, an elastic element, a valve ball, and a hollow component. Both the first and second holes include a mounting section, an abutment section, and a connecting section connected in sequence. The radial dimension of the connecting section is smaller than that of the mounting section, and the radial dimension of the abutment section gradually decreases towards the connecting section. The hollow component has a through hole, one end of the elastic element is disposed within the through hole, and the other end of the elastic element abuts against the valve ball. The radial dimension of the valve ball is larger than the radial dimension of the connecting section, and the sliding ball is at least partially disposed within the connecting section. The valve core moves in the width direction of the cylinder body to move the slider in the height direction of the cylinder body, so that the end of the valve ball away from the elastic element is adapted to contact the opening or closing connection section.

4. The pilot sequence valve for the hydraulic system of a seeder according to claim 3, characterized in that, The radial dimension of the sliding ball is 0.75 to 0.95 of the radial dimension of the connecting section, or the size difference, and the ratio of the size of the valve ball to the size of the connecting section is 0.75 to 0.

95.

5. The pilot sequence valve for the hydraulic system of a seeder according to claim 1, characterized in that, The first annular groove includes a first annular portion and a second annular portion, the end of the second annular portion away from the second annular groove is connected to the first annular portion, and the size of the first annular portion in the radial direction of the valve core gradually decreases along the direction away from the second annular portion; The third annular groove includes a third annular portion and a fourth annular portion. The end of the fourth annular portion away from the second annular groove is connected to the third annular portion. The size of the third annular portion in the radial direction of the valve core gradually decreases along the direction away from the fourth annular portion.

6. The pilot sequence valve for the hydraulic system of a seeder according to claim 1, characterized in that, It also includes an elastic positioning component and a conical ring. The second ring groove is provided with a conical ring, which is located at the center of the valve core axial direction. The positioning ball extends into the first cavity and contacts the conical ring. The cylinder body has a mounting hole, which is located between the first hole and the second hole. One end of the elastic positioning component is installed in the mounting hole to seal the mounting hole, and the other end of the elastic positioning component extends into the first cavity and contacts the conical ring.

7. The pilot sequence valve for a seeder hydraulic system according to claim 5, characterized in that, The elastic positioning component includes a seal, a positioning ball, and an elastic abutment. One end of the elastic abutment is connected to the seal, and the other end of the elastic abutment is connected to the positioning ball. A conical ring is provided in the second annular groove. The conical ring is located at the center of the valve core axial direction. The positioning ball extends into the first cavity and contacts the conical ring.

8. The pilot sequence valve for a seeder hydraulic system according to claim 6, characterized in that, The tapered ring includes a first segment and a second segment connected to each other. The first segment gradually increases in size in the radial direction of the valve core away from the first annular groove, and the second segment gradually decreases in size in the radial direction of the valve core away from the first annular groove.

9. The pilot sequence valve for a seeder hydraulic system according to claim 5, characterized in that, Also includes: A first check valve and a first flow regulating valve are disposed on the cylinder body. The cylinder body has a first flow path communicating with a second annular groove. The first flow path is respectively connected to one end of the first check valve and one end of the first flow regulating valve. A second flow regulating valve and a second check valve are installed on the cylinder body. The cylinder body has a third hole, a fourth hole, and a second flow path. One end of the second flow path is connected to the third hole and the fourth hole respectively, and the other end of the second flow path is connected to one end of the second flow regulating valve and one end of the second check valve respectively.

10. A hydraulic system for a seeder, characterized in that, include: The sequence valve is a pilot-operated sequence valve for a seeder hydraulic system according to any one of claims 1-9; A reversing valve, comprising a first port, a second port, an oil supply port, and an oil return port, wherein the oil supply port is connected to the outlet of the liquid supply assembly, the oil return port is connected to the tractor's liquid tank, the first port is connected to the other end of the second flow regulating valve and the other end of the second check valve respectively, and the second port is connected to the other end of the first check valve and the other end of the first flow regulating valve respectively. A first hydraulic element and a second hydraulic element, wherein one end of the first hydraulic element is connected to the first hole and the other end of the first hydraulic element is connected to the third hole, one end of the second hydraulic element is connected to the second hole and the other end of the second hydraulic element is connected to the fourth hole.

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