Load sensing priority valve hydraulic system

Abstract

This invention relates to the field of hydraulic systems, and specifically discloses a load-sensing priority valve hydraulic system, comprising: a load-sensing variable pump, the suction port of which is connected to an oil tank; a priority valve having a CF port for priority oil supply and an EF port for regular oil supply, the inlet of the priority valve being connected to the pressure port of the load-sensing variable pump; a load-sensing steering gear, the inlet of which is connected to the CF port of the priority valve, and the return port of which is connected to the oil tank; a load-sensing multi-way valve, the inlet of which is connected to the EF port of the priority valve, and the return port of which is connected to the oil tank; and a shuttle valve having V1 and V2 ports as signal input ports, and a C port as a signal output port; the V1 port is connected to the LS port of the load-sensing steering gear, the V2 port is connected to the LS port of the load-sensing multi-way valve, and the C port is connected to the LS port of the load-sensing variable pump. This invention solves the problems of high energy consumption and poor steering and suspension coordination performance in existing tractor hydraulic systems.

Description

Technical Field

[0001] This invention relates to the field of hydraulic systems, and more specifically to a load-sensing priority valve hydraulic system. Background Technology

[0002] Wheeled tractors are the core power machinery for agricultural production. During operation, they need to frequently perform complex actions such as driving and steering, lifting and lowering implements, turning at the edge of the field and lifting the plow. The steering system and the hydraulic system for implementing suspension are the core components to ensure operational safety and efficiency.

[0003] In the existing technology, tractor hydraulic systems mainly have two solutions: dual-pump independent oil supply and single fixed displacement pump + priority valve oil supply.

[0004] The dual-pump independent oil supply scheme features separate steering pumps and suspension working pumps, with each hydraulic system supplying oil independently. This scheme involves numerous pipelines, presents challenges in chassis layout, and results in a compact tractor chassis and engine space. The additional pumps and pipelines significantly increase the overall weight and manufacturing cost. When both pumps operate simultaneously, there is high ineffective energy consumption and severe hydraulic oil overheating. Prolonged operation in the field can easily lead to excessively high oil temperatures, aging and leakage of seals, and other problems. Furthermore, the complex dual-pump structure makes field maintenance of agricultural machinery difficult.

[0005] The single fixed-displacement pump + priority valve oil supply scheme uses a single fixed-displacement hydraulic pump in conjunction with a priority valve to achieve steering priority oil supply; this scheme is currently a common solution for small and medium horsepower tractors. However, the fixed-displacement pump has a fixed output flow rate, and regardless of whether the suspended implements are in motion or the load size, the pump always outputs at full flow. Excess oil is unloaded through the overflow valve, resulting in significant overflow losses and high overall fuel consumption. At the same time, the tractor's field conditions are complex, with large fluctuations in the load when the implements enter and exit the soil. The fixed-displacement pump cannot adapt to load changes, resulting in vibration and poor smoothness during implement lifting and lowering.

[0006] In existing technologies, although some high-horsepower tractors have introduced load sensing elements, most of them only provide load feedback for a single circuit of the steering system or suspension system, and cannot achieve coordinated acquisition of load signals from both circuits. The most typical working condition of a tractor is to lift implements while turning at the end of the field. If the steering system and suspension system are used with hydraulics at the same time, it is easy to cause insufficient steering flow, heavy steering, or slow implementation lifting speed and work jamming.

[0007] The existing hydraulic systems of tractors have the following problems: 1. High energy consumption, poor coordination between steering and suspension, complex structure, low reliability in the field, and inconvenient maintenance. Summary of the Invention

[0008] The purpose of this invention is to provide a load-sensing priority valve hydraulic system to address the above problems, thereby solving the issues of high energy consumption and poor coordination between steering and suspension in existing tractor hydraulic systems.

[0009] To achieve the above objectives, the present invention discloses a load-sensing priority valve hydraulic system, comprising: A load-sensitive variable pump, whose suction port is connected to the oil tank; The priority valve has a CF port for priority oil supply and an EF port for regular oil supply. Its inlet is connected to the pressure port of the load-sensitive variable pump, and its return port is connected to the oil tank. The load-sensing steering gear has its inlet port connected to the CF port of the priority valve and its return port connected to the oil tank. The load-sensitive multi-way valve has its inlet port connected to the EF port of the priority valve, and its return port connected to the oil tank. The shuttle valve has V1 and V2 ports as signal input ports and C port as signal output port. V1 port is connected to the LS port of the load-sensing diverter, V2 port is connected to the LS port of the load-sensitive multi-way valve, and C port is connected to the LS port of the load-sensitive variable pump. The shuttle valve is used to select the maximum load signal from the load signals input through V1 and V2 ports by pressure comparison, and feeds back the pressure signal to the load-sensitive variable pump through C port. The load-sensitive variable pump adjusts its output displacement and flow rate according to the feedback signal from C port.

[0010] With the above structure, the priority valve is divided into two independent working oil circuits: a priority oil supply branch CF and a regular oil supply branch EF, through an internal flow distribution structure. The CF port supplies oil to the load-sensing steering gear, while the EF port supplies oil to the load-sensitive multi-way valve. This structure, through the priority oil supply branch CF, rigidly guarantees the oil supply priority for tractor steering operations, effectively avoiding the problem of the suspension circuit competing for oil in the steering oil circuit under combined operating conditions. This ensures that when the tractor performs high-frequency combined operations such as turning at the edge of the field and simultaneously lifting implements, the system always prioritizes allocating sufficient flow to the steering circuit, avoiding the problem of the suspension circuit competing for steering oil in combined operating conditions. This effectively improves the potential risks of heavy steering, delayed response, and even control failure caused by competing for oil flow in traditional confluence systems, significantly enhancing the safety and handling stability of the tractor in complex farmland conditions. It effectively adapts to the combined operating conditions of tractor steering and implement lifting in the field, significantly improving the coordinated operation performance of steering and suspension.

[0011] This invention connects the LS port of the load-sensing steering gear and the LS port of the load-sensitive multi-way valve to the V1 and V2 ports of the shuttle valve, respectively. The shuttle valve uses pressure comparison to select the maximum load signal of the steering circuit and suspension circuit, and feeds this signal back to the LS port of the load-sensitive variable pump via the C port. The load-sensitive variable pump dynamically adjusts its output displacement and flow rate according to the real-time load of the system, achieving precise on-demand flow distribution. Compared with the energy consumption mode of traditional fixed displacement pump systems that always output at full flow and rely on the overflow valve for unloading, this invention effectively reduces ineffective overflow losses, significantly reduces fuel consumption of tractors in field operations, and greatly alleviates the problem of system heat generation, effectively extending the continuous operation time and the service life of the entire system.

[0012] Compared to the complex dual-pump and branch pipeline layout of traditional dual-pump independent oil supply schemes, this invention uses a single load-sensitive variable pump as the sole hydraulic power source for the system, in conjunction with a priority valve and a shuttle valve; forming an integrated structure with centralized single-pump oil supply and load-coordinated sensing. Through the single-pump confluence structure, steering priority is ensured by the priority valve, and energy-saving oil supply is achieved by combining load sensing. This structure significantly simplifies the number of hydraulic pipelines and valve groups around the chassis and engine, optimizes the layout of the tractor in its confined space, and effectively reduces the overall manufacturing cost, assembly difficulty, and subsequent field maintenance costs.

[0013] This invention, through the dual protection of rigid priority oil supply and load coordination sensing, makes the tractor's steering and implement lifting actions more responsive and stable in operation, with no obvious impact or vibration during operation, effectively improving the quality of farm operations such as plowing and rotary tillage, and thus effectively reducing driver fatigue.

[0014] Preferably, the suction port of the load-sensitive variable pump is connected to the oil tank via a suction pipe; the pressure port of the load-sensitive variable pump is connected to the inlet of the priority valve via a pressure pipe; the LS ports of the load-sensing steering gear and the load-sensitive multi-way valve are respectively connected to a first LS feedback pipe and a second LS feedback pipe, which are respectively connected to the V1 and V2 ports of the shuttle valve. This structure, by setting independent first and second LS feedback pipes, effectively avoids crosstalk and pressure fluctuation superposition between the two circuit signals during transmission, ensuring that the shuttle valve can accurately and stably obtain the true load pressure of each circuit, thereby making the displacement adjustment response of the load-sensitive variable pump more rapid and accurate.

[0015] Preferably, a return oil pipe is connected to the oil tank, and the return oil ports of the priority valve, the load-sensing steering gear, and the load-sensitive multi-way valve are all converged into a unified return oil path through the return oil pipe. The oil tank has a built-in first filter device for pre-filtering the hydraulic oil drawn into the load-sensitive variable pump from the oil tank; the first filter device is a 100-mesh filter. A second filter device is located on the return oil pipe near the oil tank for filtering the hydraulic oil that enters the oil tank after being collected through the return oil pipe; the second filter device is a 10μm filter. Preferably, the priority valve is a hydraulically controlled priority valve.

[0016] This structure incorporates a built-in 100-mesh filter in the oil tank, providing pre-filtering of the incoming hydraulic oil. This effectively intercepts large particles of impurities, preventing wear and jamming of the pump's internal structure and ensuring stable operation of the power source. The return ports of the load-sensing steering gear, load-sensitive multi-way valve, and priority valve are all connected via a return pipe to form a unified return path. The collected hydraulic oil then undergoes fine filtration through a 10μm filter before returning to the oil tank, forming a complete closed-loop hydraulic circuit. The entire system employs two stages of filtration: coarse and fine filtration. This intercepts large particles of contaminants before the pump to protect the core power components, while simultaneously filtering out fine abrasive particles and impurities generated during system circulation at the return end. This ensures that the oil entering each control valve group and actuator maintains a high level of cleanliness, significantly reducing the failure rate of the overall hydraulic system and extending the service life of the components.

[0017] In summary, the beneficial effects of the present invention are as follows: compared with the existing traditional hydraulic system of tractors, the present invention has many significant advantages and practical value.

[0018] The load-sensing priority valve hydraulic system provided by this invention constructs a rigid priority oil supply logic for the steering circuit through a hydraulically controlled priority valve. When the tractor performs high-frequency composite operations such as turning at the end of the field and simultaneously lifting implements, the system can stably allocate sufficient hydraulic flow to the steering circuit. This avoids the defects such as heavy steering and delayed response caused by implement operations occupying the oil flow in traditional confluence systems, avoids the hidden danger of steering failure under complex field conditions, and significantly improves the overall operating safety and handling stability of the tractor.

[0019] This system, through a load-sensitive variable pump paired with a shuttle valve structure, can simultaneously acquire real-time load signals from the steering and suspension circuits. It automatically filters the maximum load pressure parameters in the system and dynamically adjusts the pump's output displacement and flow rate, achieving precise on-demand distribution of hydraulic oil. This eliminates the overflow energy loss caused by the continuous operation of traditional fixed-displacement pumps, effectively reducing fuel consumption during tractor field operations. Simultaneously, the load-sensing priority valve hydraulic system provided by this invention significantly alleviates the problem of hydraulic system overheating, preventing excessive oil temperature and seal aging failures caused by prolonged continuous tractor operation. It is better suited to the working conditions of tractors operating continuously for extended periods in the field.

[0020] This invention employs a single-pump confluence integrated oil supply structure, replacing the traditional dual-pump independent oil supply mode of tractors. This significantly simplifies the hydraulic lines and valve components of the chassis and engine, optimizing the layout of the tractor chassis and engine within their limited space. This effectively reduces the overall manufacturing cost, assembly difficulty, and subsequent maintenance costs. Through a dual-circuit load coordination control mode of the steering and suspension circuits, the tractor's steering and implement lifting actions are more responsive and stable, with no significant impact or vibration during operation. This effectively improves the quality of plowing, rotary tillage, and other agricultural operations, reducing driver fatigue. Furthermore, this structure is compatible with multi-horsepower wheeled tractors and various conventional agricultural implements, possessing strong adaptability and versatility. It solves the problems of high energy consumption in tractor hydraulic systems and poor coordination between steering and suspension in existing technologies. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of one embodiment of the load sensing priority valve hydraulic system of the present invention; In the diagram: 1. Oil tank, 2. Load-sensitive variable pump, 3. Priority valve, 4. Load-sensitive steering gear, 5. Load-sensitive multi-way valve, 6. Shuttle valve, 7. Suction pipe, 8. Pressure pipe, 9. First LS feedback pipe, 10. Second LS feedback pipe, 11. Return pipe, 12. First filter device, 13. Second filter device. Detailed Implementation

[0022] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0023] Reference Figure 1 In some embodiments of the present invention, the load-sensing priority valve hydraulic system includes: The load-sensitive variable pump 2 has its suction port connected to the oil tank 1; Priority valve 3 has a CF port for priority oil supply and an EF port for regular oil supply. The oil inlet of priority valve 3 is connected to the pressure oil port of load-sensitive variable pump 2, and the oil return port of priority valve 3 is connected to oil tank 1. The load-sensing steering gear 4 has its oil inlet connected to the CF port of the priority valve 3, and its oil return port connected to the oil tank 1. The load-sensitive multi-way valve 5 has its inlet port connected to the EF port of the priority valve 3, and its return port connected to the oil tank 1. The shuttle valve 6 has ports V1 and V2 as signal input ports, and port C as a signal output port. Port V1 is connected to the LS port of the load-sensing diverter 4, port V2 is connected to the LS port of the load-sensitive multi-way valve 5, and port C is connected to the LS port of the load-sensitive variable pump 2. The shuttle valve 6 is used to select the maximum load signal from the load signals input through ports V1 and V2 by pressure comparison, and feeds back the pressure signal to the load-sensitive variable pump 2 through port C. The load-sensitive variable pump 2 adjusts its output displacement and flow rate according to the feedback signal from port C. Preferably, the priority valve 3 is a priority valve 3.

[0024] Among them, the load-sensing steering gear 4 and the load-sensitive multi-way valve 5 respectively control the steering cylinder and the rear implement suspension cylinder.

[0025] Hydraulic oil flows sequentially from the CF port of the priority valve 3 through the load-sensing steering gear 4 and the steering cylinder, and then flows back to the oil tank 1 through the return port of the load-sensing steering gear 4, forming the main steering oil circuit; the LS port of the load-sensing steering gear 4 is connected to the V1 port of the shuttle valve 6, which is used to transmit the pressure signal of the load-sensing steering gear 4 to the shuttle valve 6, forming the steering load feedback branch; the main steering oil circuit and the steering load feedback branch together constitute the steering circuit.

[0026] Hydraulic oil flows sequentially from the priority valve 3EF port through the load-sensitive multi-way valve 5 and the suspension cylinder, and then flows back to the oil tank 1 through the return port of the load-sensitive multi-way valve 5, forming the main suspension oil circuit. The LS port of the load-sensitive multi-way valve 5 is connected to the V2 port of the shuttle valve 6, which is used to transmit the pressure signal of the load-sensitive multi-way valve 5 to the shuttle valve 6, forming the suspension load feedback branch. The main suspension oil circuit and the suspension load feedback branch together constitute the suspension circuit.

[0027] Through the aforementioned improvements, the priority valve 3 is divided into two independent working oil circuits—a priority oil supply branch CF and a regular oil supply branch EF—through its internal flow distribution structure. Specifically, the CF port supplies oil to the load-sensing steering gear 4, and the EF port supplies oil to the load-sensitive multi-way valve 5. This structure, through the priority oil supply branch CF, rigidly guarantees the oil supply priority for tractor steering operations, effectively avoiding the problem of the suspension circuit competing for oil in the steering oil circuit under complex operating conditions. This ensures that when the tractor performs high-frequency complex operations such as turning at the edge of the field and simultaneously lifting implements, the system always prioritizes allocating sufficient flow to the steering circuit, avoiding the problem of the suspension circuit competing for steering oil in complex operating conditions. This effectively improves the potential hazards of heavy steering, delayed response, and even control failure caused by competing for oil flow in traditional confluence systems, significantly enhancing the safety and handling stability of the tractor in complex farmland conditions. It effectively adapts to the complex operating conditions of tractor steering and implement lifting in the field, significantly improving the coordinated operation performance of steering and suspension.

[0028] This invention connects the LS port of the load-sensing steering gear 4 and the LS port of the load-sensitive multi-way valve 5 to the V1 and V2 ports of the shuttle valve 6, respectively. The shuttle valve 6 uses pressure comparison to select the maximum load signal of the steering circuit and the suspension circuit, and feeds this signal back to the LS port of the load-sensitive variable pump 2 via the C port. The load-sensitive variable pump 2 dynamically adjusts its output displacement and flow rate according to the real-time load of the system, achieving precise on-demand flow distribution. Compared with the energy consumption mode of traditional fixed displacement pump systems that always output at full flow and rely on the overflow valve for unloading, this invention effectively reduces ineffective overflow losses, significantly reduces fuel consumption of tractors in field operations, and greatly alleviates the problem of system heat generation, effectively extending the continuous operation time and the service life of the entire system.

[0029] Compared to the complex dual-pump and branch pipeline layout of traditional dual-pump independent oil supply schemes, this invention uses a single load-sensitive variable pump 2 as the sole hydraulic power source for the system, in conjunction with a priority valve 3 and a shuttle valve 6, forming an integrated structure with centralized single-pump oil supply and load-coordinated sensing. Through the single-pump confluence structure, the priority valve 3 ensures steering priority, and the load-sensing steering gear 4 and load-sensitive multi-way valve 5 achieve energy-saving oil supply. This structure significantly simplifies the number of hydraulic pipelines and valve groups around the chassis and engine, optimizes the layout of the tractor in its confined space, and effectively reduces the overall manufacturing cost, assembly difficulty, and subsequent field maintenance costs.

[0030] This invention, through the dual protection of rigid priority oil supply and load coordination sensing, makes the tractor's steering and implement lifting actions more responsive and stable in operation, with no obvious impact or vibration during operation, effectively improving the quality of farm operations such as plowing and rotary tillage, and thus effectively reducing driver fatigue.

[0031] Reference Figure 1In some embodiments of the present invention, the suction port of the load-sensitive variable pump 2 is connected to the oil tank 1 via the suction pipe 7; the pressure port of the load-sensitive variable pump 2 is connected to the inlet of the priority valve 3 via the pressure pipe 8; the LS ports of the load-sensing steering gear 4 and the load-sensitive multi-way valve 5 are respectively connected to the first LS feedback pipe 9 and the second LS feedback pipe 10, and the first LS feedback pipe 9 and the second LS feedback pipe 10 are respectively connected to the V1 port and V2 port of the shuttle valve 6. By adopting this structure and setting independent first LS feedback pipes 9 and second LS feedback pipes 10, crosstalk and pressure fluctuation superposition between the two circuit signals during transmission are effectively avoided, ensuring that the shuttle valve 6 can accurately and stably obtain the true load pressure of each circuit, thereby making the displacement adjustment response of the load-sensitive variable pump 2 more rapid and accurate.

[0032] Reference Figure 1 In some embodiments of the present invention, a return oil pipe 11 is connected to the oil tank 1. The return oil ports of the priority valve 3, the load-sensing steering gear 4, and the load-sensitive multi-way valve 5 are all converged into a unified return oil path through the return oil pipe 11. The oil tank 1 has a built-in first filter device 12 for pre-filtering the hydraulic oil drawn into the load-sensitive variable pump 2 from the oil tank 1; the first filter device 12 is a 100-mesh filter screen. A second filter device 13 is provided on the return oil pipe 11 near the oil tank 1 for filtering the hydraulic oil that enters the oil tank 1 after being converged through the return oil pipe 11; the second filter device 13 is a 10μm filter.

[0033] This structure incorporates a built-in 100-mesh filter in the oil tank 1, which performs pre-filtering of the intake hydraulic oil, effectively intercepting large particles and preventing wear and jamming malfunctions in the pump's internal structure, thus ensuring stable operation of the power source. The return ports of the load-sensing steering gear 4, the load-sensitive multi-way valve 5, and the priority valve 3 are all converged into a unified return path via the return pipe 11. The converged hydraulic oil then undergoes fine filtration via a 10μm filter 8 before returning to the oil tank 1, forming a complete closed-loop hydraulic circuit. The hydraulic oil, after being converged via the return pipe 11, undergoes fine filtration via a 10μm filter before returning to the oil tank 1. Through this two-stage filtration, the entire system intercepts large particles of contaminants before the pump to protect the core power components, and filters out fine abrasive particles and impurities generated during system circulation at the return end. This ensures that the oil entering each control valve group and actuator maintains a high level of cleanliness, significantly reducing the failure rate of the entire hydraulic system and extending the service life of the components.

[0034] Reference Figure 1 The working principle of this invention is as follows: When the tractor is working alone in straight-line steering, the load-sensitive multi-way valve 5 is in the neutral standby state, and there is no load pressure output in the suspension circuit. When the driver operates the load-sensing steering gear 4, the steering circuit generates a working load. The load pressure signal is transmitted to the shuttle valve 6 via the first LS feedback pipe 9. The shuttle valve 6 feeds back the single steering load signal to the load-sensitive variable pump 2. Hydraulic oil enters the load-sensitive variable pump 2 from the oil tank 1 through the suction pipe 7 and a 100-mesh filter, and is then delivered to the priority valve 3 via the pressure pipe 8. The priority valve 3 distributes all hydraulic flow to the steering circuit to meet the steering requirements of the tractor. The system return oil is collected through the return pipe 11 and then finely filtered through a 10μm filter before flowing back to the oil tank 1. The load-sensitive variable pump 2 adaptively adjusts the output flow according to the steering load, with no excess overflow loss, resulting in smooth and sensitive steering control.

[0035] When the tractor implement suspension operates independently, the load-sensing steering gear 4 is in a neutral standby state, and the steering circuit has no load pressure output. The load-sensitive multi-way valve 5 is activated to control the lifting and lowering of the implement. The suspension circuit generates a corresponding working load, and the load pressure signal is input to the shuttle valve 6 through the second LS feedback pipe 10. The shuttle valve 6 selects the load signal from the suspension circuit and feeds it back to the load-sensitive variable pump 2. Hydraulic oil, after coarse filtration, is pressurized and delivered by the variable pump to the priority valve 3. The priority valve 3 switches the oil circuit to supply the full flow to the load-sensitive multi-way valve 5, driving the implement to complete lifting, deep tillage, and other operational actions. The load-sensitive variable pump 2 adjusts its displacement in real time according to the implement's operating load, achieving on-demand oil supply and effectively reducing system energy consumption and operating temperature rise.

[0036] When the tractor's steering and suspension are operating in a synchronized manner, the load-sensing steering gear 4 and the load-sensitive multi-way valve 5 work simultaneously. The steering circuit and the suspension circuit simultaneously generate load pressure signals, which are then connected to the shuttle valve 6 via the corresponding first LS feedback pipe 9 and second LS feedback pipe 10, respectively. The shuttle valve 6 automatically compares the two pressure values ​​and selects the maximum load signal to feed back to the load-sensitive variable pump 2, ensuring that the pump output matches the hydraulic flow required by the machine under maximum operating conditions. The priority valve 3 always follows the steering priority principle, prioritizing the allocation of sufficient hydraulic fluid to ensure stable operation of the steering circuit. The remaining flow is supplied to the suspension circuit to complete the lifting and lowering of implements, ensuring safe and reliable steering during high-frequency operations such as turning and plowing. The two actions do not interfere with each other, balancing operational safety and efficiency.

[0037] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A load-sensing priority valve hydraulic system, comprising an oil tank (1), characterized in that, Also includes: A load-sensitive variable pump (2) has its suction port connected to the oil tank (1); The priority valve (3) has a CF port for priority oil supply and an EF port for regular oil supply. Its inlet is connected to the pressure port of the load-sensitive variable pump (2), and its return port is connected to the oil tank (1). The load-sensing steering gear (4) has its oil inlet connected to the CF port of the priority valve (3) and its oil return port connected to the oil tank (1). The load-sensitive multi-way valve (5) has its inlet port connected to the EF port of the priority valve (3) and its return port connected to the oil tank (1). The shuttle valve (6) has a V1 port and a V2 port as signal input ports, and a C port as signal output port. The V1 port is connected to the LS port of the load sensing diverter (4), the V2 port is connected to the LS port of the load-sensitive multi-way valve (5), and the C port is connected to the LS port of the load-sensitive variable pump (2). The shuttle valve (6) is used to select the maximum load signal from the load signals input by the V1 port and the V2 port by pressure comparison, and to feed back the pressure signal to the load-sensitive variable pump (2) through the C port. The load-sensitive variable pump (2) adjusts its output displacement and flow rate according to the feedback signal of the C port.

2. The load-sensing priority valve hydraulic system as described in claim 1, characterized in that, The oil inlet of the load-sensitive variable pump (2) is connected to the oil tank (1) through the oil inlet pipe (7).

3. The load-sensing priority valve hydraulic system as described in claim 1, characterized in that, The pressure port of the load-sensitive variable pump (2) is connected to the inlet of the priority valve (3) through the pressure pipe (8).

4. The load-sensing priority valve hydraulic system as described in claim 1, characterized in that, The LS ports of the load-sensing steering gear (4) and the load-sensitive multi-way valve (5) are respectively connected to the first LS feedback tube (9) and the second LS feedback tube (10), and the first LS feedback tube (9) and the second LS feedback tube (10) are respectively connected to the V1 port and V2 port of the shuttle valve (6).

5. The load-sensing priority valve hydraulic system as described in claim 1, characterized in that, The oil tank (1) is connected to a return oil pipe (11). The return oil ports of the priority valve (3), the load-sensing steering gear (4), and the load-sensitive multi-way valve (5) are all connected to a unified return oil passage through the return oil pipe (11).

6. The load-sensing priority valve hydraulic system as described in claim 1, characterized in that, The oil tank (1) is equipped with a first filter device (12) for pre-filtering the hydraulic oil drawn from the oil tank (1) into the load-sensitive variable pump (2).

7. The load-sensing priority valve hydraulic system as described in claim 6, characterized in that, The first filter device (12) is a 100-mesh filter.

8. The load-sensing priority valve hydraulic system as described in claim 5, characterized in that, A second filter device (13) is provided on the return oil pipe (11) near the oil tank (1) to filter the hydraulic oil that enters the oil tank (1) after being collected through the return oil pipe (11).

9. The load-sensing priority valve hydraulic system as described in claim 8, characterized in that, The second filtration device (13) is a 10μm filter.

10. The load-sensing priority valve hydraulic system as described in claim 1, characterized in that, The priority valve (3) is a hydraulic priority valve.

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