Load-sensitive hydraulic control system of four-wheel drive lifting type agricultural universal chassis

Abstract

The invention discloses a load-sensitive hydraulic control system of a four-wheel drive lifting type agricultural universal chassis, and relates to the field of agricultural machinery, and the four-wheel drive lifting type agricultural universal chassis comprises a control device and a plurality of hydraulic loads; the load-sensitive hydraulic control system comprises a hydraulic oil tank, a power source, a load-sensitive hydraulic control module, a plurality of hydraulic control modules, a liquid supply pipe, a liquid return pipe and a control oil pipe; and each hydraulic control module is provided with a three-position five-way multi-path control electromagnetic valve and is connected with a hydraulic load. According to the load-sensitive hydraulic control system of the four-wheel-drive lifting type agricultural universal chassis, steering, wheel track adjustment, load power supply and chassis lifting of the agricultural universal chassis are integrated into one hydraulic system, meanwhile, hydraulic pressure is provided according to load sensitivity, and the load-sensitive hydraulic control system has the advantages of being simple in system structure, low in control difficulty, low in energy consumption, low in manufacturing cost and the like.

Description

Technical Field

[0001] The invention relates to the field of agricultural machinery, and in particular to a load-sensitive hydraulic control system of a four-wheel drive liftable agricultural universal chassis. Background Art

[0002] With the development of science and technology, agricultural machinery vehicles have become important equipment for agricultural production and are widely used in various links of agricultural production, such as sowing, spraying, irrigation, harvesting, etc. However, currently, existing agricultural machinery vehicles at home and abroad are mainly operated manually, which requires a high level of operator operation, and the harsh working environment sometimes affects the health of the operator, resulting in a waste of human resources and increasing the cost of agricultural production; in addition, manual operation increases the load of the vehicle.

[0003] The chassis widely used in agricultural machinery currently adopts the traditional mechanical transmission system with human driving to realize field walking operations. To achieve improvements to adapt to unmanned farms, the focus is mainly on the use of electronic steering wheels, electronic clutches, etc. However, agricultural machinery still needs to be controlled by hydraulic means during work due to many factors such as terrain, crops, loads, lack of charging stations, and cost. In the prior art, the steering, wheelbase adjustment to adapt to row spacing requirements or reduce the impact on crops, load power supply, chassis lifting to avoid obstacles and other operations of agricultural general chassis are all equipped with separate hydraulic systems. At the same time, the hydraulic pressure required between each system is also different, which makes it difficult to control each hydraulic system, high cost, and high energy consumption. Summary of the invention

[0004] The purpose of the present invention is to provide a load-sensitive hydraulic control system for a four-wheel drive liftable agricultural universal chassis, which integrates the steering, wheelbase adjustment, load power supply, and chassis lifting of the agricultural universal chassis into one hydraulic system, and provides hydraulic pressure according to load sensitivity. It has the advantages of simple system structure, low control difficulty, low energy consumption, low cost, etc.

[0005] The technical solution adopted by the present invention is as follows.

[0006] The load-sensitive hydraulic control system of a four-wheel drive liftable agricultural universal chassis is characterized in that: the four-wheel drive liftable agricultural universal chassis includes a control device and a plurality of hydraulic loads; the load-sensitive hydraulic control system includes a hydraulic oil tank, a power source, a load-sensitive hydraulic control module, a plurality of hydraulic control modules, a long liquid supply pipe, a long liquid return pipe, and a long control oil pipe; the load-sensitive hydraulic control module includes a variable pump and a variable blade electromagnetic control valve assembly; the variable pump is connected to the power source, the hydraulic oil tank is connected to the liquid inlet of the variable pump through a first liquid inlet pipe, the liquid outlet of the variable pump is connected to the first return pipe through a first liquid outlet pipe, and the first return pipe is connected to the hydraulic oil tank; the first liquid outlet pipe is connected to the long liquid supply pipe; the long return pipe is far away from the load-sensitive The end of the load-sensitive hydraulic control module is connected to the long control oil pipe, and the end of the long return pipe close to the load-sensitive hydraulic control module is connected to the first return pipe; the end of the long control oil pipe close to the load-sensitive hydraulic control module is connected to the oil inlet of the variable vane electromagnetic control valve assembly of the variable pump, and the oil inlet of the variable vane electromagnetic control valve assembly is provided with a pressure sensor; the oil outlet of the variable vane electromagnetic control valve assembly of the variable pump is connected to the first return pipe through the second liquid outlet pipe; the pressure sensor is connected to the variable vane electromagnetic control valve assembly and the control device of the variable pump through lines respectively; the variable vane electromagnetic control valve assembly is connected to the control vane of the variable pump; a plugging device is provided at the end of the long supply pipe away from the load-sensitive hydraulic control module;

[0007] Each hydraulic control module includes a three-position five-way multi-way control solenoid valve, a first pressure compensation valve, and a shuttle valve. The oil inlet of the three-position five-way multi-way control solenoid valve is connected to the long supply pipe through the second inlet pipe; the two oil outlets of the three-position five-way multi-way control solenoid valve are respectively connected to the third outlet pipe through a sixth outlet pipe, and the third outlet pipe is connected to the long return pipe; each fourth outlet pipe is respectively connected to the shuttle valve through a bypass pipe; the two ends of each hydraulic load are respectively connected to the two working oil ports of the three-position five-way multi-way control solenoid valve of a hydraulic control module through a fourth outlet pipe; the hydraulic load is one or more of a wheel steering hydraulic drive device, a wheelbase adjustment cylinder, a lifting cylinder, and a working hydraulic power output device; each three-position five-way multi-way control solenoid valve, a negative variable blade electromagnetic control valve assembly, and a pressure sensor are respectively connected to the control device; the first pressure compensation valve is located on the second inlet pipe; the first pressure compensation valve is connected to the shuttle valve through the fifth outlet pipe; each shuttle valve is located on the long control oil pipe;

[0008] The first liquid outlet pipe is connected to the first return pipe through the second return pipe, and the second return pipe is provided with a second pressure compensation valve; the second pressure compensation valve is connected to the long control oil pipe through the third return pipe, the first liquid outlet pipe is connected to the long return pipe through the fourth return pipe, and the fourth return pipe is provided with a first overflow valve; the fourth return pipe is connected to the third return pipe.

[0009] The beneficial effects of the present invention are: each wheel steering hydraulic drive device, each wheel spacing adjustment oil cylinder, each lifting oil cylinder, and each working hydraulic power output device are respectively connected to a three-position five-way multi-way control solenoid valve, and the oil circuit is controlled to enter or flow out of each wheel steering hydraulic drive device, each wheel spacing adjustment oil cylinder, each lifting oil cylinder, and each working hydraulic power output device through the three-position five-way multi-way control solenoid valve, so as to realize the independent control of each wheel steering hydraulic drive device, each wheel spacing adjustment oil cylinder, each lifting oil cylinder, and each working hydraulic power output device under the same hydraulic oil supply system. Each hydraulic control module is provided with a shuttle valve and a first pressure compensation valve, which can compensate for the pressure. Each shuttle valve is arranged in a long control oil pipe, and the long control oil pipe extracts oil from each shuttle valve. The long control oil pipe is connected to a pressure sensor, and the pressure sensor can measure the pressure in the control oil circuit and provide pressure information to the control device. The control device controls the operation of the variable blade electromagnetic control valve assembly according to the provided pressure information, and controls the flow and pressure of the variable pump. The greater the real-time pressure measured by the pressure sensor, the greater the flow and pressure the variable pump needs to provide. The second pressure compensation valve and the first relief valve are provided to achieve flow pressure balance of the oil inlet, oil return, and control oil circuits, thereby preventing the system from running unsteadily due to excessive flow difference.

[0010] As a preferred technical solution, each three-position five-way multi-way control solenoid valve is provided with a manual control device.

[0011] By adopting this technical solution, the opening and closing of the three-position four-way multi-control solenoid valve can be manually controlled.

[0012] As a preferred technical solution, sleeves are provided transversely at both ends of the front end and the rear end of the frame assembly, and sliding transverse sleeves are inserted at both ends of each sleeve; at least one wheel-track adjustment cylinder is hingedly connected to the middle of each sleeve, and the power output shaft of the wheel-track adjustment cylinder is hinged to the sliding transverse sleeve closest to it in the sleeve, and a lifting cylinder is vertically connected to the end of each sliding transverse sleeve away from the center of the sleeve, and the bottom end of each lifting cylinder is connected to a wheel through a plurality of wheel steering hydraulic drive devices, and a wheel drive device is provided on the wheel.

[0013] As a preferred technical solution, the first liquid outlet pipe is connected to the long liquid return pipe through a pressure reducing valve and a second overflow valve.

[0014] This technical solution can achieve pressure balance between the oil inlet and return lines, preventing the system from running unsteadily due to excessive pressure difference.

[0015] As a preferred technical solution, the second return pipe, the second pressure compensation valve, the third return pipe, the fourth return pipe, the first overflow valve, the pressure reducing valve and the second overflow valve are all installed on the third raft.

[0016] As a preferred technical solution, a load-sensitive hydraulic control module is installed on the first raft.

[0017] As a preferred technical solution, each hydraulic control module is installed on a second raft respectively.

[0018] As a preferred technical solution, the two fourth liquid outlet pipes of each wheel steering hydraulic drive device, lifting cylinder, and wheelbase adjustment cylinder are connected to a balance valve.

[0019] As a preferred technical solution, the working hydraulic power output device is a working hydraulic cylinder.

[0020] As a preferred technical solution, the working hydraulic power output device is a working hydraulic motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The invention is a three-dimensional structural diagram of a four-wheel drive liftable agricultural universal chassis.

[0022] Figure 2 yes Figure 1 A partial enlarged view of part A.

[0023] Figure 3 yes Figure 1 A partial enlarged view of part B.

[0024] Figure 4 yes Figure 1 A partial enlarged view of part C.

[0025] Figure 5 yes Figure 1 The schematic diagram of the sleeve at the front end of the hidden frame assembly (1) of the four-wheel drive liftable agricultural universal chassis is shown.

[0026] Figure 6 yes Figure 5 A partial enlarged view of part D.

[0027] Figure 7 It is a structural schematic diagram of a preferred embodiment of a load-sensitive hydraulic control system.

[0028] Figure 8 yes Figure 7 A partial enlarged view of part F.

[0029] Fig. 9 yes Figure 8 A partial enlarged view of part J.

[0030] Fig.10 yes Figure 7 A partial enlarged view of part G.

[0031] Fig.11 yes Fig.10 A partial enlarged view of part K.

[0032] Fig.12 yes Figure 7 A partial enlarged view of part H.

[0033] Fig.13 yes Figure 7 A partial enlarged view of part I.

[0034] Fig.14 The invention is a three-dimensional structural diagram of a four-wheel drive liftable agricultural universal chassis.

[0035] Fig.15 yes Fig.14 The schematic diagram of the sleeve at the front end of the hidden frame assembly (1) of the four-wheel drive liftable agricultural universal chassis is shown.

[0036] Among them: frame assembly-1; sliding cross sleeve-10; sleeve-11; wheel-12; wheel drive motor-121; wheel hydraulic drive motor-122;

[0037] Wheel steering hydraulic drive device-13; lifting cylinder-14; wheelbase adjustment cylinder-15; working hydraulic power output device-16; balance valve-17; suspension frame-18; wheel hydraulic drive motor hydraulic supply station-19; battery-110;

[0038] Hydraulic oil tank-2; first liquid inlet pipe-21;

[0039] Power source - 3;

[0040] Load-sensing hydraulic control module-4; variable displacement pump-41; variable displacement vane electromagnetic control valve assembly-42; oil inlet of variable displacement vane electromagnetic control valve assembly-421;

[0041] First liquid outlet pipe-43; second liquid outlet pipe-44; control blade of variable pump-45;

[0042] Hydraulic control module-5; three-position five-way multi-way control solenoid valve-51; first pressure compensation valve-52; shuttle valve-53; bypass pipe-54; third liquid outlet pipe-55; sixth liquid outlet pipe-551; oil inlet-57 of three-position five-way multi-way control solenoid valve; oil outlet-56 of three-position five-way multi-way control solenoid valve; second liquid inlet pipe-58; fourth liquid outlet pipe-59; working oil port-510 of three-position five-way multi-way control solenoid valve; fifth liquid outlet pipe-511; emergency manual control device-512;

[0043] Long liquid supply tube-6;

[0044] Long liquid return pipe-7; first return pipe-71; second return pipe-72; second pressure compensation valve-73; third return pipe-74; fourth return pipe-75; first overflow valve-76; pressure reducing valve-77; second overflow valve-78;

[0045] Long control oil pipe-8; pressure sensor-81; plugging device-82;

[0046] The first raft plate is 91; the second raft plate is 92; the third raft plate is 93. DETAILED DESCRIPTION

[0047] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0048] Example 1. Figure 1-13 As shown, the load-sensitive hydraulic control system of the four-wheel drive liftable agricultural universal chassis is characterized in that: the four-wheel drive liftable agricultural universal chassis includes a control device and twelve hydraulic loads; the load-sensitive hydraulic control system includes a hydraulic oil tank 2, a power source 3, a load-sensitive hydraulic control module 4, twelve hydraulic control modules 5, a long liquid supply pipe 6, a long liquid return pipe 7, and a long control oil pipe 8; the load-sensitive hydraulic control module 4 includes a variable pump 41 and a variable blade electromagnetic control valve assembly 42; the variable pump 41 is connected to the power source 3.

[0049] The hydraulic oil tank 2 is connected to the liquid inlet of the variable pump 41 through the first liquid inlet pipe 21 , the liquid outlet of the variable pump 41 is connected to the first return pipe 71 through the first liquid outlet pipe 43 , and the first return pipe 71 is connected to the hydraulic oil tank 2 .

[0050] The first liquid outlet pipe 43 is connected to the long liquid supply pipe 6; the end of the long return pipe 7 away from the load-sensitive hydraulic control module 4 is connected to the long control oil pipe 8, and the end of the long return pipe 7 close to the load-sensitive hydraulic control module 4 is connected to the first return pipe 71.

[0051] The end of the long control oil pipe 8 close to the load-sensitive hydraulic control module 4 is connected to the oil inlet 421 of the variable vane electromagnetic control valve assembly of the variable pump 41. The oil inlet 421 of the variable vane electromagnetic control valve assembly is provided with a pressure sensor 81. The pressure sensor 81 is connected to the control device. The control device is a PLC. The frame assembly is provided with a plurality of sensors and a remote controller connected to the control device.

[0052] The oil outlet 422 of the variable vane electromagnetic control valve assembly of the variable pump 41 is connected to the first return pipe 71 through the second liquid outlet pipe 44; the pressure sensor 81 is connected to the variable vane electromagnetic control valve assembly 42 and the control device of the variable pump 41 through lines respectively; the variable vane electromagnetic control valve assembly 42 is connected to the control vane 45 of the variable pump; a plugging device 82 is provided at the end of the long liquid supply pipe 6 away from the load-sensitive hydraulic control module 4.

[0053] Each hydraulic control module 5 includes a three-position five-way multi-way control solenoid valve 51, a first pressure compensation valve 52, and a shuttle valve 53. The oil inlet 57 of the three-position five-way multi-way control solenoid valve is connected to the long supply pipe 6 through a second liquid inlet pipe 58; the two oil outlets 56 of the three-position five-way multi-way control solenoid valve 51 are respectively connected to the third liquid outlet pipe 55 through a sixth liquid outlet pipe 551, and the third liquid outlet pipe 55 is connected to the long return liquid pipe 7; each fourth liquid outlet pipe 551 is respectively connected to the shuttle valve 53 through a bypass flow pipe 54; the two ends of each hydraulic load are respectively connected to the two working oil ports 510 of the three-position five-way multi-way control solenoid valve 51 of a hydraulic control module 5 through a fourth liquid outlet pipe 59. The hydraulic load is one or more of the wheel steering hydraulic drive device 13, the wheelbase adjustment cylinder 15, the lifting cylinder 14, and the working hydraulic power output device 16; each three-position five-way multi-way control solenoid valve 51, the variable blade solenoid control valve assembly 42, and the pressure sensor 81 are respectively connected to the control device; the first pressure compensation valve 52 is located on the second liquid inlet pipe 58; the first pressure compensation valve 52 is connected to the shuttle valve 53 through the fifth liquid outlet pipe 511; each shuttle valve 53 is located on the long control oil pipe 8. In each hydraulic control module 5, when the upper position of the three-position five-way multi-way control solenoid valve 51 is connected, the hydraulic oil flows in from the right end of the hydraulic load, flows out from the left end of the hydraulic load, and flows into the long return pipe 7 from the fourth liquid outlet pipe 551 close to the hydraulic load; when the lower position of the three-position five-way multi-way control solenoid valve 51 is connected, the hydraulic oil flows in from the left end of the hydraulic load, flows out from the right end of the hydraulic load, and flows into the long return pipe 7 from the fourth liquid outlet pipe 551 far away from the hydraulic load. When the middle position of the three-position five-way multi-way control solenoid valve 51 is connected, the hydraulic oil in the hydraulic load does not flow.

[0054] The first liquid outlet pipe 43 is connected to the first return pipe 71 through the second return pipe 72, and the second return pipe 72 is provided with a second pressure compensation valve 73; the second pressure compensation valve 73 is connected to the long control oil pipe 8 through the third return pipe 74, the first liquid outlet pipe 43 is connected to the long return pipe 7 through the fourth return pipe 75, and the fourth return pipe 75 is provided with a first overflow valve 76; the fourth return pipe 75 is connected to the third return pipe 74.

[0055] Each three-position five-way multi-way control electromagnetic valve 51 is provided with an artificial control device 512. With this technical solution, the three-position four-way multi-way control electromagnetic valve 51 can be manually controlled to open and close.

[0056] Both ends of the front end and the rear end of the frame assembly 1 are laterally provided with sleeves 11, and both ends of each sleeve 11 are inserted with sliding transverse sleeves 10; a wheel-track adjustment cylinder 15 is laterally hinged in the middle of each sleeve 11, and the power output shaft of the wheel-track adjustment cylinder 15 is hinged to the sliding transverse sleeve 10 closest to it in the sleeve 11, and each sliding transverse sleeve 10 is vertically connected to a lifting cylinder 14 at the center end away from the sleeve 11, and the bottom end of each lifting cylinder 14 is connected to a wheel 12 through a wheel steering hydraulic drive device 13, and a wheel drive device is provided on the wheel 12.

[0057] The frame assembly 1 is provided with four wheels 12, four wheel steering hydraulic drive devices 13, four lifting cylinders 14, two wheel track adjustment cylinders 15, and two working hydraulic power output devices 16. The two ends of the four wheel steering hydraulic drive devices 13, the four lifting cylinders 14, the two wheel track adjustment cylinders 15, and the two working hydraulic power output devices 16 are respectively connected to the two working oil ports 510 of the three-position five-way multi-way control solenoid valve 51 of a hydraulic control module 5 through a fourth outlet pipe 59. The frame assembly 1 is provided with a battery, and each wheel drive device is a wheel drive motor 121, and each wheel drive motor 121 is connected to the battery 110.

[0058] The first liquid outlet pipe 43 is connected to the long liquid return pipe 7 through the pressure reducing valve 77 and the second overflow valve 78. With this technical solution, the pressure balance between the oil inlet pipeline and the oil return pipeline can be achieved to prevent the system from running unsteadily due to excessive pressure difference.

[0059] The second return pipe 72 , the second pressure compensation valve 73 , the third return pipe 74 , the fourth return pipe 75 , the first overflow valve 76 , the pressure reducing valve 77 and the second overflow valve 78 are all installed on the third raft 93 .

[0060] The load sensing hydraulic control module 4 is mounted on the first raft 91 .

[0061] Each hydraulic control module 5 is mounted on a second raft 92 .

[0062] The two fourth liquid outlet pipes 59 connected to the wheel steering hydraulic drive device 13, the lifting cylinder 14, and the wheelbase adjustment cylinder 15 are connected to a balancing valve 17. The balancing valve 17 is a dynamic differential pressure balancing valve. The dynamic differential pressure balancing valve uses the differential pressure to adjust the valve opening, and uses the pressure drop change of the valve core to compensate for the change of pipeline resistance, so that the differential pressure can be kept basically unchanged when the working conditions change. Its principle is that within a certain flow range, it can effectively control the differential pressure of the controlled system to be constant, that is, when the differential pressure of the system increases, through the automatic closing action of the valve, it can ensure that the differential pressure of the controlled system increases. On the contrary, when the differential pressure decreases, the valve automatically opens and the differential pressure remains constant. The self-powered differential pressure control valve automatically closes the valve plug within the control range. When the differential pressure at both ends of the valve exceeds the preset value, the valve plug automatically opens and automatically adjusts the opening under the action of the pressure-sensitive membrane to keep the differential pressure at both ends of the valve relatively constant.

[0063] Each working hydraulic power output device 16 is a working hydraulic cylinder.

[0064] The beneficial effects of the present invention are as follows: each wheel steering hydraulic drive device 13, each wheel gauge adjustment cylinder 15, each lifting cylinder 14, and each working hydraulic power output device 16 are respectively connected to a three-position five-way multi-way control solenoid valve 51, and the three-position five-way multi-way control solenoid valve 51 is used to control the oil circuit to enter or flow out of each wheel steering hydraulic drive device 13, each wheel gauge adjustment cylinder 15, each lifting cylinder 14, and each working hydraulic power output device 16, so as to realize independent control of each wheel steering hydraulic drive device 13, each wheel gauge adjustment cylinder 15, each lifting cylinder 14, and each working hydraulic power output device 16 under the same hydraulic oil supply system. Each hydraulic control module 5 is provided with a shuttle valve 53 and a first pressure compensation valve 52, which can compensate for pressure. Each shuttle valve 53 is arranged on a long control oil pipe 8, and the long control oil pipe 8 extracts oil from each shuttle valve 53. The long control oil pipe 8 is connected to a pressure sensor 81, and the pressure sensor 81 can measure the pressure in the control oil circuit and provide pressure information to the control device. The control device controls the operation of the variable blade electromagnetic control valve assembly according to the pressure information provided, and controls the flow and pressure of the variable pump. The greater the real-time pressure measured by the pressure sensor 81, the greater the flow and pressure that the variable pump needs to provide. The second pressure compensation valve 73 and the first overflow valve 76 can achieve flow balance of the oil inlet pipeline, the oil return pipeline, and the long control oil pipe 8 to prevent the situation where the system is unstable due to excessive flow difference.

[0065] Example 2. Figure 14-15 As shown, the difference between this embodiment and embodiment 1 is that the frame assembly 1 is provided with four wheels 12, eight wheel steering hydraulic drive devices 13, four lifting cylinders 14, four wheel spacing adjustment cylinders 15, and two working hydraulic power output devices 16.

[0066] The two ends of the front end and the two ends of the rear end of the frame assembly 1 are each provided with a sleeve 11 transversely, and the two ends of each sleeve 11 are inserted with a sliding transverse sleeve 10; the middle part of each sleeve 11 is transversely hinged with two wheel spacing adjustment cylinders 15, and the power output shaft of the wheel spacing adjustment cylinder 15 is hinged with the sliding transverse sleeve 10 closest to it in the sleeve 11, and the end of each sliding transverse sleeve 10 away from the center of the sleeve 11 is vertically connected with a lifting cylinder 14, and the bottom end of each lifting cylinder 14 is connected to a wheel 12 through two wheel steering hydraulic drive devices 13, and the wheel 12 is provided with a wheel drive device. The two ends of the eight wheel steering hydraulic drive devices 13, the four lifting cylinders 14, the four wheel spacing adjustment cylinders 15, and the two working hydraulic power output devices 16 are respectively connected to the two working oil ports of a three-position five-way multi-way control solenoid valve of a hydraulic control module through a fourth outlet pipe. The wheel drive device is a wheel hydraulic drive motor 122, and the wheel hydraulic drive motor 122 is connected to the wheel hydraulic drive motor hydraulic supply station 19. Each working hydraulic power output device 16 is a working hydraulic motor.

[0067] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A load-sensitive hydraulic control system for a four-wheel drive liftable agricultural universal chassis, characterized in that: The four-wheel drive liftable agricultural universal chassis comprises a control device and a plurality of hydraulic loads; the load-sensitive hydraulic control system comprises a hydraulic oil tank (2), a power source (3), a load-sensitive hydraulic control module (4), a plurality of hydraulic control modules (5), a long liquid supply pipe (6), a long liquid return pipe (7), and a long control oil pipe (8); the load-sensitive hydraulic control module (4) comprises a variable pump (41) and a variable blade electromagnetic control valve assembly (42); the variable pump (41) is connected to the power source (3); the hydraulic oil tank (2) is connected to the liquid inlet of the variable pump (41) through a first liquid inlet pipe (21); the liquid outlet of the variable pump (41) is connected to a first return pipe (71) through a first liquid outlet pipe (43); the first return pipe (71) is connected to the hydraulic oil tank (2); the first liquid outlet pipe (43) is connected to the long liquid supply pipe (6); the end of the long return pipe (7) away from the load-sensitive hydraulic control module (4) is connected to the long control oil pipe (8) The end of the long return pipe (7) close to the load-sensitive hydraulic control module (4) is connected to the first return pipe (71); the end of the long control oil pipe (8) close to the load-sensitive hydraulic control module (4) is connected to the oil inlet (421) of the variable vane electromagnetic control valve assembly of the variable pump (41), and the oil inlet (421) of the variable vane electromagnetic control valve assembly is provided with a pressure sensor (81); the oil outlet (422) of the variable vane electromagnetic control valve assembly of the variable pump (41) is connected to the first return pipe (71) through the second liquid outlet pipe (44); the pressure sensor (81) is connected to the variable vane electromagnetic control valve assembly (42) and the control device of the variable pump (41) through lines respectively; the variable vane electromagnetic control valve assembly (42) is connected to the control vane (45) of the variable pump; and the end of the long supply pipe (6) far from the load-sensitive hydraulic control module (4) is provided with a plug (82); Each hydraulic control module (5) comprises a three-position five-way multi-way control solenoid valve (51), a first pressure compensation valve (52), and a shuttle valve (53); an oil inlet (57) of the three-position five-way multi-way control solenoid valve is connected to a long liquid supply pipe (6) through a second liquid inlet pipe (58); two oil outlets (56) of the three-position five-way multi-way control solenoid valve (51) are respectively connected to a third liquid outlet pipe (55) through a sixth liquid outlet pipe (551); the third liquid outlet pipe (55) is connected to a long liquid return pipe (7); each sixth liquid outlet pipe (551) is respectively connected to the shuttle valve (53) through a bypass pipe (54); both ends of each hydraulic load are respectively connected to a hydraulic control module (51) through a fourth liquid outlet pipe (59); 5) are connected to two working oil ports (510) of a three-position five-way multi-way control solenoid valve (51); the hydraulic load is one or more of a wheel steering hydraulic drive device (13), a wheelbase adjustment cylinder (15), a lifting cylinder (14), and a working hydraulic power output device (16); each three-position five-way multi-way control solenoid valve (51), a variable blade solenoid control valve assembly (42), and a pressure sensor (81) are respectively connected to the control device; the first pressure compensation valve (52) is located on the second liquid inlet pipe (58); the first pressure compensation valve (52) is connected to the shuttle valve (53) through the fifth liquid outlet pipe (511); each shuttle valve (53) is located on the long control oil pipe (8); The first liquid outlet pipe (43) is connected to the first return pipe (71) via the second return pipe (72), and the second return pipe (72) is provided with a second pressure compensation valve (73); the second pressure compensation valve (73) is connected to the long control oil pipe (8) via the third return pipe (74); the first liquid outlet pipe (43) is connected to the long return pipe (7) via the fourth return pipe (75), and the fourth return pipe (75) is provided with a first overflow valve (76); the fourth return pipe (75) is connected to the third return pipe (74).

2. The load-sensitive hydraulic control system of the four-wheel drive liftable agricultural universal chassis according to claim 1, characterized in that: Each three-position five-way multi-way control solenoid valve (51) is provided with a manual control device (512).

3. The load-sensitive hydraulic control system of the four-wheel drive liftable agricultural universal chassis according to claim 1, characterized in that: The two ends of the front end and the two ends of the rear end of the frame assembly (1) are each laterally provided with a sleeve (11), and the two ends of each sleeve (11) are respectively inserted with a sliding transverse sleeve (10); at least one wheelbase adjustment cylinder (15) is laterally hinged in the middle of each sleeve (11), and the power output shaft of the wheelbase adjustment cylinder (15) is hinged to the sliding transverse sleeve (10) closest to it in the sleeve (11); the center end of each sliding transverse sleeve (10) away from the sleeve (11) is vertically connected to a lifting cylinder (14), and the bottom end of each lifting cylinder (14) is connected to a wheel (12) through a plurality of wheel steering hydraulic drive devices (13), and the wheel (12) is provided with a wheel drive device.

4. The load-sensitive hydraulic control system of the four-wheel drive liftable agricultural universal chassis as claimed in claim 3, characterized in that: The first liquid outlet pipe (43) is connected to the long liquid return pipe (7) via a pressure reducing valve (77) and a second overflow valve (78).

5. The load-sensitive hydraulic control system of the four-wheel drive liftable agricultural universal chassis as claimed in claim 4, characterized in that: The second return pipe (72), the second pressure compensation valve (73), the third return pipe (74), the fourth return pipe (75), the first overflow valve (76), the pressure reducing valve (77) and the second overflow valve (78) are all installed on the third raft (93).

6. The load-sensitive hydraulic control system of the four-wheel drive liftable agricultural universal chassis according to claim 1, characterized in that: A load sensing hydraulic control module (4) is mounted on the first raft (91).

7. The load-sensing hydraulic control system of the four-wheel drive liftable agricultural universal chassis according to claim 1, characterized in that: Each hydraulic control module (5) is mounted on a second raft (92).

8. The load-sensing hydraulic control system of the four-wheel drive liftable agricultural universal chassis according to claim 1, characterized in that: Two fourth liquid outlet pipes (59) connected to the wheel steering hydraulic drive device (13), the lifting cylinder (14) and the wheelbase adjustment cylinder (15) are connected to a balance valve (17).

9. The load-sensitive hydraulic control system of the four-wheel drive liftable agricultural universal chassis according to claim 1, characterized in that: The working hydraulic power output device (16) is a working hydraulic cylinder.

10. The load-sensing hydraulic control system of the four-wheel drive liftable agricultural universal chassis according to claim 1, characterized in that: The working hydraulic power output device (16) is a working hydraulic motor.

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