Hydraulic gear shifting control system of agricultural machine

Abstract

The invention belongs to the technical field of hydraulic control, and relates to an agricultural machine hydraulic gear shifting control system. Comprising an energy accumulator, a lubricating module, a gear control module, a power take-off control module, a differential lock control module, a four-wheel drive control module and a parking control module, and by means of the accurate control characteristic of a hydraulic system, all the control modules can achieve accurate control over steering, hanging, operation device adjustment, power output and other functions of the agricultural machine. Operators can accurately control various actions of the agricultural machine through simple operation, the requirement of modern agriculture for accurate operation is met, and the operation quality is improved. The trafficability and the driving stability are improved; emergency support can be provided when system pressure fluctuates or power is insufficient, it is ensured that the agricultural machine can work normally under various complex working conditions, and the adaptability of the agricultural machine to different working environments is enhanced. And due to the arrangement of the oil path filter module, impurities in the hydraulic oil are effectively filtered, and abrasion and the fault occurrence rate in the system can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic control and relates to a hydraulic shift control system for agricultural machinery. Background Art

[0002] As one of the core technologies of modern agricultural machinery, hydraulic control systems play a key role in improving operational efficiency, enabling precise control, and adapting to complex working conditions. Using the principle of hydraulic transmission, they convert the mechanical energy of the engine or electric motor into hydraulic energy. Using components such as valves, actuators, and sensors, they distribute power and control motion. These systems are widely used in steering, suspension, operating mechanism adjustment, and power output for equipment such as tractors, harvesters, and seeders.

[0003] Traditional hydraulic systems consist of a power unit (hydraulic pump), control elements (directional valves, pressure valves, flow valves), actuators (hydraulic cylinders, motors), and auxiliary components (oil tanks, piping). Early systems often used mechanical or manual valve control, which resulted in delayed response and low control accuracy. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydraulic shift control system for agricultural machinery to solve the technical problems of delayed response and low control accuracy of traditional hydraulic systems.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention discloses a hydraulic shift control system for agricultural machinery, comprising an oil supply circuit and an oil return circuit. The oil supply circuit is respectively connected to an accumulator, a lubrication module, a gear control module, a power take-off control module, a differential lock control module, a four-wheel drive control module and a parking control module through an oil circuit filter module. The lubrication module, the gear control module, the power take-off control module, the differential lock control module, the four-wheel drive control module and the parking control module are all connected to the oil return circuit.

[0006] Furthermore, an oil pump is provided on the oil supply line, the outlet of the oil pump is respectively connected to the inlet of the oil pump safety valve and the inlet of the oil filter module, and the outlet of the oil pump safety valve is connected to the oil return line.

[0007] Furthermore, the oil filter module includes a coarse filter and a fine filter, the oil supply line passes through the coarse filter and the fine filter in sequence, and the fine filter is respectively connected to the accumulator, the gear control module, the lubrication module, the power take-off control module, the differential lock control module, the four-wheel drive control module and the parking control module; The coarse filter is connected in parallel with a coarse filter safety valve, and the fine filter is respectively connected in parallel with a fine filter safety valve and a pressure difference switch; A main oil circuit temperature sensor and a main oil circuit pressure sensor are provided at the outlet of the fine filter.

[0008] Furthermore, the lubrication module includes an oil circuit cooling module, a lubrication pressure sensor and several lubrication oil channels. The oil circuit filter module is connected to the several lubrication oil channels through the oil circuit cooling module. The lubrication pressure sensor is provided between the oil circuit cooling module and the several lubrication oil channels.

[0009] Furthermore, the oil circuit cooling module includes a main pressure regulating valve and an oil cooler, the outlet of the oil circuit filter module is connected to the inlet of the main pressure regulating valve, the outlet of the main pressure regulating valve is connected to the inlet of the oil cooler, the outlet of the oil cooler is respectively connected to the lubrication module and the return oil circuit, and the oil cooler is connected in parallel with an oil cooler safety valve.

[0010] Furthermore, the gear control module includes a first gear control module, a second gear control module, and a reverse gear control module; the outlet of the oil filter module is connected to the first gear control module, the second gear control module, and the reverse gear control module, respectively; and the first gear control module, the second gear control module, and the reverse gear control module are all connected to the oil return line; The first gear control module includes a first proportional control solenoid valve, a first buffer pressure hole, and a first clutch control piston chamber connected in sequence, a first clutch pressure sensor is provided between the first proportional control solenoid valve and the first buffer pressure hole, and the first proportional control solenoid valve is connected to the oil return line; The second gear control module includes a second proportional control solenoid valve, a second buffer pressure hole, and a second clutch control piston chamber connected in sequence, a second clutch pressure sensor is provided between the second proportional control solenoid valve and the second buffer pressure hole, and the second proportional control solenoid valve is connected to the oil return line; The reverse gear control module includes a third proportional control solenoid valve, a third buffer pressure hole and a third clutch control piston chamber connected in sequence. A third clutch pressure sensor is provided between the third proportional control solenoid valve and the third buffer pressure hole. The third proportional control solenoid valve is connected to the return oil circuit.

[0011] Furthermore, the power take-off control module includes a fourth proportional control solenoid valve, a fourth buffer pressure hole and a fourth clutch control piston chamber connected in sequence, a fourth clutch pressure sensor is provided between the fourth proportional control solenoid valve and the fourth buffer pressure hole, and the fourth proportional control solenoid valve is connected to the return oil circuit.

[0012] Furthermore, the differential lock control module includes a fifth proportional control solenoid valve, a fifth buffer pressure hole and a fifth clutch control piston chamber connected in sequence, a fifth clutch pressure sensor is provided between the fifth proportional control solenoid valve and the fifth buffer pressure hole, and the fifth proportional control solenoid valve is connected to the return oil circuit.

[0013] Furthermore, the four-wheel drive control module includes a four-wheel drive switch control solenoid valve, a sixth buffer pressure hole and a sixth clutch control piston chamber connected in sequence, a sixth clutch pressure sensor is provided between the four-wheel drive switch control solenoid valve and the sixth buffer pressure hole, and the four-wheel drive switch control solenoid valve is connected to the return oil circuit.

[0014] Furthermore, the parking control module includes a parking switch solenoid valve, a parking pressure valve, a seventh buffer pressure hole and a seventh clutch control piston chamber connected in sequence, a seventh clutch pressure sensor is provided between the parking pressure valve and the seventh buffer pressure hole, and the parking switch solenoid valve is connected to the return oil circuit.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a continuous and stable supply of hydraulic oil to each functional module through the oil supply circuit; filters out impurities in the hydraulic oil through the oil circuit filter module; ensures the stability of the system by absorbing pressure shocks and fluctuations; provides lubrication for each moving part through the lubrication module; realizes rapid gear adjustment of the agricultural machinery through the gear control module to meet the speed and torque requirements in different operating scenarios; realizes additional power take-off function in any gear through the power take-off control module; improves the vehicle's ability to escape from difficulties through the differential lock control module, and improves the passability and driving stability of the agricultural machinery; enables the agricultural machinery to match more types of allowable working conditions through the four-wheel drive control module; controls the parking brake of the agricultural machinery through the parking control module; collects the hydraulic oil after the working cycle is completed through the return oil circuit and transports it back to the oil pool. The present invention realizes precise control and rapid response of multiple functions of the agricultural machinery through the coordinated work of various modules. With the help of the precise control characteristics of the hydraulic system, the present invention enables each control module to realize precise control of the steering, suspension, working device adjustment and power output functions of the agricultural machinery. Operators can precisely control the various movements of agricultural machinery through simple operations, meeting the precision work requirements of modern agriculture and improving work quality. This system improves passability and driving stability; it can provide emergency support when system pressure fluctuates or power is insufficient, ensuring the machinery's normal operation in a variety of complex working conditions and enhancing its adaptability to diverse operating environments. The oil filter module effectively filters impurities from the hydraulic oil, reducing wear and tear within the system and the incidence of failures. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1A system schematic diagram of an embodiment disclosed in the present invention; Figure 2 This is a usage status diagram of the CR gear + PTO + two-wheel drive function of the embodiment disclosed by the present invention.

[0017] Among them: 1. Oil pump; 2. Coarse filter; 3. Fine filter; 4. Accumulator; 5. Main pressure regulating valve; 6. First proportional control solenoid valve; 7. Second proportional control solenoid valve; 8. Third proportional control solenoid valve; 9. Fourth proportional control solenoid valve; 10. Fifth proportional control solenoid valve; 11. Four-wheel drive switch control solenoid valve; 12. Parking pressure valve; 13. Parking switch solenoid valve; 14. Oil cooler; 15. Oil filter module; 16. Oil supply line; 17. Oil return line; 18. Oil cooling module ;19, gear control module;20, lubrication module;C1, first gear control module;C2, second gear control module;CR, reverse gear control module;CP, power take-off control module;DIF, differential lock control module;4WD, four-wheel drive control module;PB, parking control module;S1, oil pump safety valve;S2, coarse filter safety valve;S3, fine filter safety valve;S4, oil cooler safety valve;S5, lubrication safety valve;K, pressure differential switch;P1, main oil circuit temperature sensor;P2, main oil circuit pressure sensor; P3, lubrication pressure sensor; P4, first clutch pressure sensor; P5, second clutch pressure sensor; P6, third clutch pressure sensor; P7, fourth clutch pressure sensor; P8, fifth clutch pressure sensor; P9, sixth clutch pressure sensor; P10, seventh clutch pressure sensor; H1, first clutch control piston chamber; H2, second clutch control piston chamber; H3, third clutch control piston chamber; H4, fourth clutch control piston chamber; H5, fifth clutch control piston chamber; H6, sixth clutch control piston chamber; H7, seventh clutch control piston chamber; K1, first buffer pressure hole; K2, second buffer pressure hole; K3, third buffer pressure hole; K4, fourth buffer pressure hole; K5, fifth buffer pressure hole; K6, sixth buffer pressure hole; K7, seventh buffer pressure hole; TL, lubrication oil channel. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "first," "second," and the like in the description of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatus.

[0020] The present invention is described in further detail below with reference to the accompanying drawings: Example 1: See also Figure 1The present invention discloses a hydraulic shift control system for agricultural machinery, including an oil supply circuit 16 and an oil return circuit 17. The oil supply circuit 16 provides a continuous and stable supply of hydraulic oil to each functional module to ensure that each component of the system can operate normally. It is a basic channel for realizing power distribution and motion control. The oil return circuit 17 is used to collect the hydraulic oil after completing the working cycle and transport it back to the oil pool. The oil supply circuit 16 is respectively connected to the accumulator 4, the lubrication module 20, the gear control module 19, the power take-off control module CP, the differential lock control module DIF, the four-wheel drive control module 4WD and the parking control module PB through the oil filter module 15. The lubrication module 20, the gear control module 19, the power take-off control module CP, the differential lock control module DIF, the four-wheel drive control module 4WD and the parking control module PB are all connected to the oil return circuit 17. The oil filter module 15 removes impurities, particulate matter, and other contaminants from the hydraulic oil, preventing them from entering the subsequent control modules and actuators. This prevents wear and blockage caused by impurities, extends the service life of system components, and ensures stable and reliable operation. The accumulator 4 absorbs pressure shocks and fluctuations, stabilizing system pressure. It also serves as an auxiliary hydraulic source, further ensuring system stability. The lubrication module 20 provides lubrication for all moving parts. The gear control module 19 enables rapid and accurate shifting of the agricultural machinery's gears, meeting the speed and torque requirements of various operating scenarios and improving the machinery's operating efficiency and adaptability. The power take-off control module CP enables additional power take-off in any gear. The differential lock control module DIF allows the vehicle to escape muddy conditions with all tires rotating at the same speed, improving the machinery's maneuverability and driving stability and preventing wheel slippage that could affect operation progress. The four-wheel drive control module 4WD allows the machinery to adapt to a wider range of permitted operating conditions while enhancing the user experience. The parking control module PB is used to control the parking brake of the agricultural machinery.

[0021] In the embodiment of the present invention, an oil pump 1 is provided on the oil supply circuit 16 , and the outlet of the oil pump 1 is respectively connected to the inlet of the oil pump safety valve S1 and the inlet of the oil circuit filter module 15 , and the outlet of the oil pump safety valve S1 is connected to the oil return circuit 17 .

[0022] In the embodiment of the present invention, the oil filter module 15 includes a coarse filter 2 and a fine filter 3. The oil supply line 16 passes through the coarse filter 2 and the fine filter 3 in sequence. The fine filter 3 is respectively connected to the accumulator 4, the gear control module 19, the lubrication module 20, the power take-off control module CP, the differential lock control module DIF, the four-wheel drive control module 4WD, and the parking control module PB. The coarse filter 2 is connected in parallel with a coarse filter safety valve S2, and the fine filter 3 is connected in parallel with a fine filter safety valve S3 and a pressure difference switch K; A main oil circuit temperature sensor P1 and a main oil circuit pressure sensor P2 are provided at the outlet of the fine filter 3 .

[0023] In an embodiment of the present invention, the lubrication module 20 includes an oil circuit cooling module 18, a lubrication pressure sensor P3 and several lubrication oil channels TL. The oil circuit filter module 15 is connected to the several lubrication oil channels TL through the oil circuit cooling module 18. The lubrication pressure sensor P3 is provided between the oil circuit cooling module 18 and the several lubrication oil channels TL.

[0024] In an embodiment of the present invention, the oil circuit cooling module 18 includes a main pressure regulating valve 5 and an oil cooler 14. The outlet of the oil circuit filter module 15 is connected to the inlet of the main pressure regulating valve 5, and the outlet of the main pressure regulating valve 5 is connected to the inlet of the oil cooler 14. The outlet of the oil cooler 14 is respectively connected to the lubrication module 20 and the return oil circuit 17. The oil cooler 14 is connected in parallel with an oil cooler safety valve S4.

[0025] In the embodiment of the present invention, the gear control module 19 includes a first gear control module C1, a second gear control module C2, and a reverse gear control module CR. The outlet of the oil filter module 15 is connected to the first gear control module C1, the second gear control module C2, and the reverse gear control module CR, respectively. The first gear control module C1, the second gear control module C2, and the reverse gear control module CR are all connected to the oil return line 17. The first gear control module C1 includes a first proportional control solenoid valve 6, a first buffer pressure hole K1, and a first clutch control piston chamber H1 connected in sequence. A first clutch pressure sensor P4 is provided between the first proportional control solenoid valve 6 and the first buffer pressure hole K1. The first proportional control solenoid valve 6 is connected to the oil return line 17. The second gear control module C2 includes a second proportional control solenoid valve 7, a second buffer pressure hole K2, and a second clutch control piston chamber H2, which are connected in sequence. A second clutch pressure sensor P5 is provided between the second proportional control solenoid valve 7 and the second buffer pressure hole K2. The second proportional control solenoid valve 7 is connected to the oil return line 17. The reverse gear control module CR includes a third proportional control solenoid valve 8, a third buffer pressure hole K3 and a third clutch control piston chamber H3 connected in sequence. A third clutch pressure sensor P6 is provided between the third proportional control solenoid valve 8 and the third buffer pressure hole K3. The third proportional control solenoid valve 8 is connected to the return oil circuit 17.

[0026] In an embodiment of the present invention, the power take-off control module CP includes a fourth proportional control solenoid valve 9, a fourth buffer pressure hole K4 and a fourth clutch control piston chamber H4 connected in sequence. A fourth clutch pressure sensor P7 is provided between the fourth proportional control solenoid valve 9 and the fourth buffer pressure hole K4. The fourth proportional control solenoid valve 9 is connected to the return oil circuit 17.

[0027] In an embodiment of the present invention, the differential lock control module DIF includes a fifth proportional control solenoid valve 10, a fifth buffer pressure hole K5 and a fifth clutch control piston chamber H5 connected in sequence. A fifth clutch pressure sensor P8 is provided between the fifth proportional control solenoid valve 10 and the fifth buffer pressure hole K5. The fifth proportional control solenoid valve 10 is connected to the return oil circuit 17.

[0028] In an embodiment of the present invention, the four-wheel drive control module 4WD includes a four-wheel drive switch control solenoid valve 11, a sixth buffer pressure hole K6 and a sixth clutch control piston chamber H6 connected in sequence. A sixth clutch pressure sensor P9 is provided between the four-wheel drive switch control solenoid valve 11 and the sixth buffer pressure hole K6. The four-wheel drive switch control solenoid valve 11 is connected to the return oil circuit 17.

[0029] In an embodiment of the present invention, the parking control module PB includes a parking switch solenoid valve 13, a parking pressure valve 12, a seventh buffer pressure hole K7 and a seventh clutch control piston chamber H7 connected in sequence. A seventh clutch pressure sensor P10 is provided between the parking pressure valve 12 and the seventh buffer pressure hole K7, and the parking switch solenoid valve 13 is connected to the return oil circuit 17.

[0030] The present invention realizes precise control and rapid response of multiple functions of agricultural machinery through the coordinated work of various modules. With the help of the precise control characteristics of the hydraulic system, each control module can realize precise control of functions such as steering, suspension, working device adjustment and power output of agricultural machinery. Operators can precisely control various actions of agricultural machinery through simple operations, meet the requirements of modern agriculture for precise operations, and improve the quality of operations. The design of the differential lock control module DIF, the four-wheel drive control module 4WD, etc. enables agricultural machinery to quickly adjust the drive mode when encountering complex road conditions such as muddy, soft, and rugged roads, thereby improving passability and driving stability; the presence of the accumulator 4 can provide emergency support when the system pressure fluctuates or the power is insufficient, ensuring that the agricultural machinery can work normally under various complex working conditions, and enhancing the adaptability of agricultural machinery to different working environments. The setting of the oil filter module 15 effectively filters impurities in the hydraulic oil, which can reduce wear and failure rate within the system.

[0031] Example 2: See also Figure 1This embodiment discloses a hydraulic shift control system for agricultural machinery, including an oil supply circuit 16, an oil filter module 15, an oil cooling module 18, a lubrication module 20, a gear control module 19, a power take-off control module CP, a differential lock control module DIF, a four-wheel drive control module 4WD, and a parking control module PB.

[0032] The oil filter module 15 includes a coarse filter 2 with a one-way coarse filter safety valve S2 and a fine filter 3 with a one-way fine filter safety valve S3 and a pressure differential switch K.

[0033] The modules connected to and controlled by the hydraulic system are mainly divided into a lubrication module 20 and a control system.

[0034] The lubrication module 20 includes an oil cooler 14 with an oil cooler safety valve S4 and a lubrication oil channel TL to which the cooled oil is directed. The oil cooler safety valve S4 is a safety one-way valve.

[0035] The control system can be divided into a gear control module 19 and a function control module.

[0036] The gear control module 19 includes three modules: a first gear control module C1 , a second gear control module C2 and a reverse gear control module CR. Each gear control module is composed of a control solenoid valve connected to a control clutch.

[0037] The functional control modules include the power take-off control module CP, the differential lock control module DIF, the four-wheel drive control module 4WD and the parking control module PB. The parking control module PB includes a parking switch solenoid valve 13, a parking pressure valve 12 and the seventh clutch control piston chamber H7 connected to the control oil channel. The composition and structure of the other three functional modules are consistent with those of the gear control module.

[0038] The hydraulic control system's connections are divided into oil supply and return connections. The oil supply connection is as follows: the oil sump is connected to the oil pump 1, which is then connected to the coarse filter 2 and the fine filter 3 in sequence. The first oil outlet of the fine filter 3 is connected to the main pressure regulating valve 5, which is then connected to the oil cooler 14, which is then connected to each lubricating oil channel TL. The second to seventh oil outlets of the fine filter 3 are connected in sequence to the control solenoid valves of the first gear control module C1, the second gear control module C2, the reverse gear control module CR, the power take-off control module CP, the differential lock control module DIF, and the four-wheel drive control module 4WD, and then to the control clutches corresponding to each solenoid valve. The eighth oil outlet of the fine filter 3 is connected in sequence to the parking switch solenoid valve 13 and the parking pressure valve 12, and then to the control piston chamber of the parking clutch. The ninth oil outlet of the fine filter 3 is connected to the accumulator 4, which is used to absorb pressure shocks and fluctuations to stabilize the system pressure. It can also serve as an auxiliary hydraulic source to further ensure system stability.

[0039] In the oil supply connection, the front section of each of the seven control clutches is equipped with a buffer pressure hole to reduce clutch pressure fluctuations and improve control accuracy.

[0040] Safety valves are installed at the inlets of the coarse filter 2, fine filter 3, and oil cooler 14. These valves prevent the corresponding devices from becoming clogged or failing, allowing for gear shifting. A pressure differential switch K is also installed at the inlet of the fine filter 3. This monitors the pressure difference between the oil filter inlet and outlet, and is used to determine if the filter is clogged, facilitating timely cleaning and replacement of the filter element.

[0041] The return oil connection is: the first return oil channel is the outlet of the oil pump 1 connected to the oil pool through the return oil channel 17; the second return oil channel is the outlet of the oil cooler 14 connected to the oil pool through the return oil channel 17; the third to eighth return oil channels are the control clutches of the first gear control module C1, the second gear control module C2, the reverse gear control module CR, the power take-off control module CP, the differential lock control module DIF and the four-wheel drive control module 4WD connected to the oil pool through the return oil channel in the proportional control solenoid valve of the corresponding module; the ninth return oil channel is the clutch of the parking control module PB connected to the oil pool through the return oil channels of the parking pressure valve 12 and the parking switch solenoid valve 13 in sequence.

[0042] In summary, as agricultural machinery hydraulic systems develop towards modularization, intelligence, and high energy efficiency, the demand for various functions is increasing. This invention divides the demand for agricultural machinery hydraulic systems into different modules to meet the different types and quantities of hydraulic control systems required by different OEMs. Positions for most modules available on the market can be reserved on the hydraulic valve plate, and the specific requirements can be determined by the OEM. The cost of each module is refined, making it more suitable for OEMs with high cost control requirements. The modular arrangement structure of the present invention is more conducive to accurately finding the location of the fault and facilitating the replacement of the corresponding fault module; Each module in the control system of the present invention is independently self-controlled, and the mutual influence between modules is almost negligible. Therefore, the use requirements of different modules can be freely combined and matched according to actual working conditions, which has higher compatibility.

[0043] The solenoid valves used in the modules of the control system of the present invention are all of the same type. Using the same type of hydraulic components in batches has a natural advantage in cost control and is more convenient for subsequent maintenance and replacement.

[0044] The safety valves used in the hydraulic system of the present invention are all traditional spring-type safety valves, which have the advantages of low cost, simple structure, easy layout, and easy assembly and disassembly.

[0045] The parking control system module of the present invention adds an additional pressure valve to the structure of the control solenoid valve to limit the maximum pressure required by the parking clutch; at the same time, the solenoid valve is used as the parking switch valve, so that other modules can also operate normally when the vehicle is parked, such as the function of the CP power take-off module used for parking.

[0046] In order to cater to the development trend of intelligent agricultural machinery, the setting of multiple sensor interfaces will become a common phenomenon. The lubrication system in the hydraulic system and each module in the control system are equipped with independent sensor detection ports to facilitate the collection of data and transmit it to the TCU controller to realize the subsequent development of fully intelligent operations in the industry.

[0047] The overall hydraulic system has a simple structure, and all control components can use the same type, so it has an excellent cost advantage. It is also equipped with a high-precision proportional solenoid valve and a buffer pressure hole, which can perform high-precision electronic signal control.

[0048] Example 3: See also Figure 1 This embodiment provides a hydraulic shift control system for agricultural machinery and its working principle. The hydraulic control system includes five hydraulic components, namely an oil pump 1, a coarse filter 2, a fine filter 3, an accumulator 4, and an oil cooler 14; a main pressure regulating valve 5; seven hydraulic control modules with different functions, each module has a clutch control piston chamber and a proportional control solenoid valve, the parking module has not only a parking switch solenoid valve 13, but also a parking pressure valve 12; the rest are additionally equipped with six safety valves.

[0049] First, as Figure 1 As shown, at this time, all hydraulic control components are in an inoperative state, and all types of solenoid valves and pressure valves are also in an oil drain / closed state; when the parking switch solenoid valve 13 is in the current state, it represents that the parking function is in a normally open mode. When the solenoid valve is energized and the state is switched, the parking function is canceled.

[0050] like Figure 2 The figure shows the CR gear position, PTO, and two-wheel drive function. The main oil line from oil pump 1 connects to coarse filter 2 and fine filter 3 in sequence. The outlet oil of fine filter 3 is divided into nine oil lines. The first oil line is connected to accumulator 4; the second oil line is connected to main pressure regulating valve 5; the third through ninth oil lines are connected to the control solenoid valves of seven control system modules: the first proportional control solenoid valve 6, the second proportional control solenoid valve 7, the third proportional control solenoid valve 8, the fourth proportional control solenoid valve 9, the fifth proportional control solenoid valve 10, the four-wheel drive switch control solenoid valve 11, and the parking switch solenoid valve 13.

[0051] The oil at the first outlet of the fine filter 3 is led to the accumulator 4, which is used to absorb pressure shocks and fluctuations to stabilize the system pressure. It can also be used as an auxiliary hydraulic source to further ensure the stability of the system.

[0052] The second outlet of the fine filter 3 flows to the main pressure-regulating valve 5, which has its own feedback oil passage. When the oil pump begins operating, pressurized oil pushes the valve core through the feedback oil passage, causing the main pressure-regulating valve 5 to switch to its operating state. The oil at the outlet of the main pressure-regulating valve 5 is connected to the oil cooler 14. The cooled oil then flows directly through the various lubrication passages TL to the transmission / load-bearing mechanisms requiring lubrication.

[0053] The third to ninth outlet oil lines of the fine filter 3 are respectively connected to the proportional control solenoid valves corresponding to seven control system modules, including the first gear control module C1, the second gear control module C2, the reverse gear control module CR, the power take-off control module CP, the differential lock control module DIF, the four-wheel drive control module 4WD and the parking control module PB; for modules other than the parking control module PB, the outlet oil of the first proportional control solenoid valve 6, the second proportional control solenoid valve 7, the third proportional control solenoid valve 8, the fourth proportional control solenoid valve 9, the fifth proportional control solenoid valve 10 and the four-wheel drive switch control solenoid valve 11 goes directly to the clutch pressure control chamber for control through the buffer pressure hole; the ninth outlet oil line of the fine filter 3 is connected to the parking switch solenoid valve 13, and then the maximum pressure is limited by the parking pressure valve 12 with a feedback oil channel. The pressure after the limit is directly controlled by the oil through the seventh buffer pressure hole K7 to the seventh clutch control piston chamber H7.

[0054] exist Figure 2 In the state of , the reverse gear control module CR, the differential lock control module DIF, and the four-wheel drive control module 4WD function are enabled in the control module. Therefore, only the third proportional control solenoid valve 8, the fifth proportional control solenoid valve 10, and the four-wheel drive switch control solenoid valve 11 in the corresponding modules are in the open state. The closed solenoid valve can drain the oil in the clutch control chamber and return it to the oil sump through the oil return channel for oil circulation.

[0055] An oil pump safety valve S1 is provided at the outlet of the oil pump 1, which allows the oil at the oil pump outlet that is higher than the set pressure to pass through the oil pump safety valve S1 to the return oil channel for oil recirculation.

[0056] The coarse filter 2 is also equipped with a coarse filter safety valve S2, which can ensure that when the coarse filter fails / is blocked / damaged, the pressure of the oil going to the coarse filter 2 will gradually increase. After increasing to a certain value, it will break through the pressure limit of the coarse filter safety valve S2 and go to the next hydraulic component. The safety valve and the corresponding oil channel can be used as a safe alternative oil channel.

[0057] The fine filter 3 is also equipped with a fine filter safety valve S3, whose function and effect are equivalent to the coarse filter safety valve S2; the fine filter 3 is additionally equipped with a pressure difference switch K, which is used to monitor the pressure difference between the oil inlet and outlet of the fine filter 3, and is used to determine whether the oil filter is blocked, so as to facilitate timely cleaning and replacement of the oil filter element.

[0058] The oil cooler 14 is also equipped with an oil cooler safety valve S4 , whose function and effect are equivalent to those of the coarse filter safety valve S2 .

[0059] A lubrication safety valve S5 is provided at the outlet of the oil cooler 14. Generally speaking, the pressure value required for the lubricating oil is generally too low, so it is necessary to reduce the pressure through the lubrication safety valve S5 to avoid damage to the components that need to be lubricated due to excessive lubricating oil pressure.

[0060] In the corresponding control system modules, the first gear control module C1 enables the vehicle to move forward in first gear; the second gear control module C2 enables the vehicle to move forward in second gear; the reverse gear control module CR enables the vehicle to reverse in reverse. On some vehicles, reverse gear can also be achieved through motor reversal or other means. In this case, the reverse gear control module CR can be directly eliminated; the power take-off control module CP enables additional power take-off in any gear. The specific module combination mode depends on the OEM's requirements and electronic control. The combination of the differential lock control module DIF allows the vehicle to escape from muddy conditions by rotating all tires at the same speed, so this mode is also called escape mode. The combination of the four-wheel drive control module 4WD allows agricultural machinery to adapt to a wider range of permitted operating conditions while improving the user experience. The parking control module PB is standard on the vehicle and is equipped with an additional switch control solenoid valve for use in conjunction with other control modules, such as parking power take-off, when the vehicle is parked.

[0061] The agricultural machinery hydraulic system of the present invention has strong modularity, which is conducive to the development of the agricultural machinery hydraulic system towards intelligence and high energy efficiency, and provides more powerful technical support for precision agriculture.

[0062] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A hydraulic shift control system for agricultural machinery, characterized in that: The invention comprises an oil supply circuit (16) and an oil return circuit (17), wherein the oil supply circuit (16) is respectively connected to an accumulator (4), a lubrication module (20), a gear control module (19), a power take-off control module (CP), a differential lock control module (DIF), a four-wheel drive control module (4WD) and a parking control module (PB) through an oil filter module (15), and the lubrication module (20), the gear control module (19), the power take-off control module (CP), the differential lock control module (DIF), the four-wheel drive control module (4WD) and the parking control module (PB) are all connected to the oil return circuit (17).

2. The hydraulic shift control system for agricultural machinery according to claim 1, characterized in that: An oil pump (1) is provided on the oil supply circuit (16), the outlet of the oil pump (1) is respectively connected to the inlet of an oil pump safety valve (S1) and the inlet of the oil circuit filter module (15), and the outlet of the oil pump safety valve (S1) is connected to the oil return circuit (17).

3. The hydraulic shift control system for agricultural machinery according to claim 1, characterized in that: The oil filter module (15) includes a coarse filter (2) and a fine filter (3), the oil supply circuit (16) passes through the coarse filter (2) and the fine filter (3) in sequence, and the fine filter (3) is respectively connected to an accumulator (4), a gear control module (19), a lubrication module (20), a power take-off control module (CP), a differential lock control module (DIF), a four-wheel drive control module (4WD), and a parking control module (PB); The coarse filter (2) is connected in parallel with a coarse filter safety valve (S2), and the fine filter (3) is connected in parallel with a fine filter safety valve (S3) and a pressure difference switch (K); A main oil circuit temperature sensor (P1) and a main oil circuit pressure sensor (P2) are provided at the outlet of the fine filter (3).

4. The hydraulic shift control system for agricultural machinery according to claim 1, characterized in that: The lubrication module (20) comprises an oil circuit cooling module (18), a lubrication pressure sensor (P3) and a plurality of lubrication oil passages (TL); the oil circuit filter module (15) is connected to the plurality of lubrication oil passages (TL) via the oil circuit cooling module (18); and the lubrication pressure sensor (P3) is provided between the oil circuit cooling module (18) and the plurality of lubrication oil passages (TL).

5. The hydraulic shift control system for agricultural machinery according to claim 4, characterized in that: The oil circuit cooling module (18) comprises a main pressure regulating valve (5) and an oil cooler (14); the outlet of the oil circuit filter module (15) is connected to the inlet of the main pressure regulating valve (5); the outlet of the main pressure regulating valve (5) is connected to the inlet of the oil cooler (14); the outlet of the oil cooler (14) is respectively connected to the lubrication module (20) and the oil return circuit (17); and the oil cooler (14) is connected in parallel with an oil cooler safety valve (S4).

6. The hydraulic shift control system for agricultural machinery according to claim 1, characterized in that: The gear control module (19) includes a first gear control module (C1), a second gear control module (C2) and a reverse gear control module (CR); the outlet of the oil filter module (15) is connected to the first gear control module (C1), the second gear control module (C2) and the reverse gear control module (CR), respectively; the first gear control module (C1), the second gear control module (C2) and the reverse gear control module (CR) are all connected to the oil return circuit (17); The first gear control module (C1) comprises a first proportional control solenoid valve (6), a first buffer pressure hole (K1) and a first clutch control piston chamber (H1) connected in sequence, a first clutch pressure sensor (P4) is provided between the first proportional control solenoid valve (6) and the first buffer pressure hole (K1), and the first proportional control solenoid valve (6) is connected to the oil return line (17); The second gear control module (C2) comprises a second proportional control solenoid valve (7), a second buffer pressure hole (K2) and a second clutch control piston chamber (H2) connected in sequence, a second clutch pressure sensor (P5) is provided between the second proportional control solenoid valve (7) and the second buffer pressure hole (K2), and the second proportional control solenoid valve (7) is connected to the oil return line (17); The reverse gear control module (CR) comprises a third proportional control solenoid valve (8), a third buffer pressure hole (K3) and a third clutch control piston chamber (H3) connected in sequence, a third clutch pressure sensor (P6) is provided between the third proportional control solenoid valve (8) and the third buffer pressure hole (K3), and the third proportional control solenoid valve (8) is connected to the oil return line (17).

7. The hydraulic shift control system for agricultural machinery according to claim 1, characterized in that: The power take-off control module (CP) comprises a fourth proportional control solenoid valve (9), a fourth buffer pressure hole (K4) and a fourth clutch control piston chamber (H4) connected in sequence, a fourth clutch pressure sensor (P7) is provided between the fourth proportional control solenoid valve (9) and the fourth buffer pressure hole (K4), and the fourth proportional control solenoid valve (9) is connected to the oil return line (17).

8. The hydraulic shift control system for agricultural machinery according to claim 1, characterized in that: The differential lock control module (DIF) comprises a fifth proportional control solenoid valve (10), a fifth buffer pressure hole (K5) and a fifth clutch control piston chamber (H5) connected in sequence, a fifth clutch pressure sensor (P8) is provided between the fifth proportional control solenoid valve (10) and the fifth buffer pressure hole (K5), and the fifth proportional control solenoid valve (10) is connected to the oil return line (17).

9. The hydraulic shift control system for agricultural machinery according to claim 1, characterized in that: The four-wheel drive control module (4WD) comprises a four-wheel drive switch control solenoid valve (11), a sixth buffer pressure hole (K6) and a sixth clutch control piston chamber (H6) connected in sequence, a sixth clutch pressure sensor (P9) is provided between the four-wheel drive switch control solenoid valve (11) and the sixth buffer pressure hole (K6), and the four-wheel drive switch control solenoid valve (11) is connected to the oil return line (17).

10. The agricultural machinery hydraulic shift control system according to claim 1, characterized in that: The parking control module (PB) comprises a parking switch solenoid valve (13), a parking pressure valve (12), a seventh buffer pressure hole (K7) and a seventh clutch control piston chamber (H7) connected in sequence, a seventh clutch pressure sensor (P10) is provided between the parking pressure valve (12) and the seventh buffer pressure hole (K7), and the parking switch solenoid valve (13) is connected to the oil return line (17).

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