Load-sensitive prefill valve, steering and braking hydraulic system and mining dump truck

Abstract

The utility model relates to a prefill valve, in particular to a load-sensitive prefill valve, a steering and braking hydraulic system and a mining dump truck, in the prefill valve, the oil inlet end and the oil outlet end of a first one-way valve are correspondingly connected with an oil receiving opening and a steering oil conveying opening; two ends of the first electromagnetic switch valve are correspondingly connected with the oil outlet end of the first one-way valve and the steering liquid filling oil port; two ends of the second electromagnetic switch valve are communicated with the steering liquid filling oil port and the oil return port; the oil receiving port is simultaneously communicated with the hydraulic control end of the liquid filling pressure control valve and the oil inlet end of the first liquid filling shuttle valve; the two liquid filling ends of the first liquid filling shuttle valve are correspondingly connected with the steering liquid filling oil port and the oil inlet end of the second liquid filling shuttle valve; the liquid filling end of the second liquid filling shuttle valve is connected with a brake liquid filling oil port; the first oil inlet end of the shuttle valve is connected with the LS1 oil port, and the oil outlet end of the shuttle valve is connected with the LS oil port; the oil inlet end, the oil outlet end and the oil return end of the liquid filling pressure control valve are correspondingly connected with the hydraulic control end, the second oil inlet end of the shuttle valve and the oil return opening. The prefill valve and the system thereof are simple, convenient to arrange and safe.

Description

Technical Field

[0001] The utility model relates to a liquid filling valve, in particular to a load-sensitive liquid filling valve, a steering and braking hydraulic system and a mining dump truck. Background Art

[0002] The steering and braking hydraulic systems of mining dump trucks use constant pressure variable systems, such as Figure 1 As shown, the steering system is usually composed of components such as a constant pressure variable displacement pump 38, a steering diverter valve block 35, a hydraulic steering control unit 50, a steering accumulator 40, and a steering cylinder 33. The braking system is composed of components such as a brake diverter valve block 36, a hydraulic brake control unit 34, and a brake accumulator 60.

[0003] In the above-mentioned steering and braking hydraulic system, the working process of the steering hydraulic system is as follows:

[0004] When the vehicle is started without steering, the constant pressure variable pump 38 draws oil from the hydraulic oil tank 31 and outputs it at high pressure. After being filtered by the high pressure filter 32, the oil enters the steering diverter valve block 35 to connect the steering accumulator 40 and fill the steering accumulator 40 with fluid. When the set upper limit pressure of the steering accumulator 40 is reached, the filling stops and the pressure is maintained.

[0005] When the vehicle is turning, the hydraulic steering control unit 50 is activated, and the steering accumulator 40 and the constant pressure variable pump 38 simultaneously provide hydraulic oil for steering. The overload valve absorbs the impact of the road surface on the steering cylinder during the steering process.

[0006] When the power source fails and emergency steering is performed, the steering accumulator 40 alone provides pressurized oil for emergency steering to ensure driving safety.

[0007] When the vehicle is overhauled, the electromagnetic reversing valve inside the steering diverter valve block 35 is turned on, and the oil in the steering accumulator 40 returns to the hydraulic oil tank 31 for pressure relief, thereby ensuring the safety of the overhaul.

[0008] In the above steering and braking hydraulic systems, the working process of the braking hydraulic system is as follows:

[0009] When the vehicle is started, the flow diversion pipeline of the steering diverter valve block 35 is connected to the brake diverter valve block 36, and then the flow is diverted to each accumulator in the brake accumulator 60 for filling through the brake diverter valve block 36. When the upper limit pressure of the brake accumulator is reached, the filling is stopped and the pressure is maintained.

[0010] During driving, parking and braking: by operating the brake switch in the cab, the brake accumulator 60 preferentially provides pressurized oil to the hydraulic brake control unit to realize the braking function.

[0011] The above steering and brake hydraulic system has the following deficiencies:

[0012] When the vehicle is in a non-steering state, such as parking or driving in a straight line in the starting state, the steering hydraulic system is in a high-pressure unloading state and the energy loss is still large.

[0013] The entire system includes both a steering diverter valve block 35 and a brake diverter valve block 36, which has many components and a high failure rate, and is not conducive to arrangement on a complete vehicle.

[0014] The steering accumulator 40 used for emergency steering also needs to provide pressurized oil to participate in the steering action. If the power source fails when the system steering pressure is low, the steering accumulator 40 cannot provide sufficient pressurized oil for emergency steering, resulting in the emergency steering function not meeting the requirements and posing a driving safety hazard. Utility Model Content

[0015] The technical problem to be solved by the utility model is the shortcomings of the steering and braking hydraulic systems of the existing mining dump trucks, and provides a load-sensitive filling valve, a steering and braking hydraulic system and a mining dump truck.

[0016] The utility model provides a technical solution to achieve its purpose: a load-sensitive filling valve, which has an oil receiving port, an LS oil port, an LS1 oil port, a steering oil delivery port, a steering filling oil port, a brake filling oil port, and an oil return port;

[0017] It includes: a first one-way valve, a first electromagnetic switch valve and a second electromagnetic switch valve which are normally cut off, a first liquid-filling shuttle valve, a second liquid-filling shuttle valve, a shuttle valve, and a liquid-filling pressure control valve;

[0018] The oil inlet and outlet ends of the first one-way valve are connected to the oil receiving port and the steering oil delivery port; the two ends of the first electromagnetic switch valve are connected to the oil outlet end of the first one-way valve and the steering oil filling port; one end of the second electromagnetic switch valve is connected to the steering oil filling port, and the other end is connected to the oil return port;

[0019] The oil receiving port is simultaneously connected to the hydraulic control end of the filling pressure control valve and the oil inlet end of the first filling shuttle valve; the first filling end of the first filling shuttle valve is connected to the steering filling oil port, the second filling end of the first filling shuttle valve is connected to the oil inlet end of the second filling shuttle valve; the filling end of the second filling shuttle valve is connected to the brake filling oil port;

[0020] The first oil inlet end of the shuttle valve is connected to the LS1 oil port, and the oil outlet end is connected to the LS oil port;

[0021] The filling pressure control valve is a two-position three-way valve, whose oil inlet end is connected to the hydraulic control end, the oil outlet end is connected to the second oil inlet end of the shuttle valve, the oil return end is connected to the oil return port, and the oil outlet end is selectively connected to the oil inlet end or the oil return end and is connected to the oil inlet end under normal conditions.

[0022] In the load-sensitive filling valve of the utility model, the load-sensitive filling valve further comprises a first damping valve, and the first damping valve is arranged on the communicating oil path between the second electromagnetic switch valve and the oil return port.

[0023] In the load-sensitive filling valve of the utility model, the load-sensitive filling valve also includes a second one-way valve, which is arranged in the connecting oil path between the oil receiving port and the oil inlet end of the first filling shuttle valve, and the oil inlet end is connected to the oil receiving port, and the oil outlet end is simultaneously connected to the oil inlet end of the first filling shuttle valve and the hydraulic control end of the filling pressure control valve.

[0024] In the load-sensitive filling valve of the utility model, the load-sensitive filling valve further comprises a second damping valve, and the second damping valve is arranged on the communicating oil path between the oil receiving port and the oil inlet end of the second one-way valve.

[0025] In the load-sensitive filling valve of the utility model, the load-sensitive filling valve also includes a pressure switch, a first pressure sensor, and a second pressure sensor. The pressure detection end of the pressure switch is connected to the oil receiving port; the pressure detection end of the first pressure sensor is connected to the oil outlet end of the first one-way valve, and the pressure detection end of the second pressure sensor is connected to the steering filling oil port.

[0026] In the load-sensitive filling valve of the utility model, the brake filling oil port includes a first brake filling oil port and a second brake filling oil port; the two filling ends of the second filling shuttle valve are correspondingly connected to the first brake filling oil port and the second brake filling oil port.

[0027] In the load-sensitive filling valve of the utility model, the load-sensitive filling valve further comprises a third brake filling oil port, and the third brake filling oil port is connected to the second filling end of the first filling shuttle valve.

[0028] The utility model provides a technical solution to achieve its purpose: a steering and braking hydraulic system, comprising a hydraulic oil tank, a load-sensitive variable pump whose oil suction port is connected to the hydraulic oil tank, a steering cylinder, a hydraulic steering control unit for controlling and driving the steering cylinder, a hydraulic brake control unit, a steering accumulator, and a brake accumulator; the system also includes the aforementioned load-sensitive filling valve, the oil receiving port is connected to the pump port of the load-sensitive variable pump, the steering oil delivery port is connected to the working oil inlet of the hydraulic steering control unit, the steering accumulator is connected to the steering filling oil port, the working oil inlet of the hydraulic brake control unit and the brake accumulator are both connected to the brake filling oil port, the return oil port is connected to the hydraulic oil tank via an oil return filter, the load signal output end of the hydraulic steering control unit is connected to the LS1 oil port, and the LS oil port is connected to the control oil port of the load-sensitive variable pump.

[0029] In the steering and braking hydraulic system of the utility model, the system further comprises a third brake accumulator;

[0030] The load-sensing filling valve also has a third brake filling oil port connected to the second filling end of the first filling shuttle valve;

[0031] The brake filling oil port comprises a first brake filling oil port and a second brake filling oil port corresponding to the two filling ends of the second filling shuttle valve;

[0032] The working oil inlet of the hydraulic brake control unit includes a first brake oil inlet, a second brake oil inlet, and a third brake oil inlet;

[0033] The brake accumulator comprises a first brake accumulator and a second brake accumulator;

[0034] The first brake oil inlet and the first brake accumulator are connected to the first brake filling oil port;

[0035] The second brake oil inlet port and the second brake accumulator are connected to the second brake filling oil port;

[0036] The third brake oil inlet port and the third brake accumulator are connected to the third brake filling oil port.

[0037] The utility model provides a technical solution for achieving the purpose: a mining dump truck, which has the aforementioned load-sensitive filling valve, or has the aforementioned steering and braking hydraulic system.

[0038] Compared with the prior art, in the utility model, a load-sensitive filling valve is matched with a load-sensitive variable pump and a load-sensitive steering gear in the system, and the flow and pressure required for hydraulic braking and hydraulic steering are transmitted to the load-sensitive variable pump through a load-sensitive signal. The load-sensitive variable pump adjusts the pressure and displacement at any time to realize oil supply on demand and achieve energy saving; the load-sensitive filling valve is highly integrated, with fewer pipeline connections, thereby improving the reliability of the system and the convenience of layout; the pressure oil in the steering accumulator is used to supply oil to the hydraulic steering control unit when the first electromagnetic switch valve is powered off, thereby avoiding the problem of insufficient pressure during emergency steering oil supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the steering and braking hydraulic system of an existing mining dump truck.

[0040] Figure 2 It is a schematic diagram of the load-sensitive liquid-filling valve of the utility model.

[0041] Figure 3 The utility model is a schematic diagram of a steering and braking hydraulic system of a mining dump truck.

[0042] Parts names and serial numbers in the figure:

[0043] Load-sensitive filling valve 10, first one-way valve 11, first solenoid switch valve 12, second solenoid switch valve 13, first filling shuttle valve 14, second filling shuttle valve 15, filling pressure control valve 16, shuttle valve 17, second one-way valve 18, first damping valve 19, second damping valve 20, pressure switch 21, first pressure sensor 22, second pressure sensor 23.

[0044] Hydraulic oil tank 31 , high-pressure filter 32 , steering cylinder 33 , hydraulic brake control unit 34 , steering diverter valve block 35 , brake diverter valve block 36 , return oil filter 37 , constant pressure variable pump 38 , load sensitive variable pump 39 .

[0045] Turn to the accumulator 40.

[0046] Hydraulic steering control unit 50 , steering gear 51 , flow amplification valve 52 .

[0047] Brake accumulator 60 , first brake accumulator 61 , second brake accumulator 6 , third brake accumulator 63 . DETAILED DESCRIPTION

[0048] The specific implementation scheme is described below with reference to the accompanying drawings.

[0049] In this specification, ordinal numbers such as "first" and "second" are added to avoid confusion between constituent elements, and do not indicate a certain order or sequence such as order of importance or logical order. Terms without ordinal numbers in this specification may have ordinal numbers added to them in the claims, and terms with ordinal numbers in this specification may have their ordinal numbers omitted in the claims.

[0050] Embodiment 1.

[0051] like Figure 2 As shown, the load-sensitive filling valve in this embodiment has: an oil receiving port (P port), an LS oil port, an LS1 oil port, a steering oil delivery port (A port), a steering filling oil port (A1 port), a brake filling oil port (B1 port, B2 port, B3 port), and an oil return port (T port). In addition, optional spare interfaces (SW1 port, SW2 port) and the like may be provided.

[0052] The load-sensitive filling valve includes: a first one-way valve 11, a first electromagnetic switch valve 12 and a second electromagnetic switch valve 13 which are normally cut off, a first filling shuttle valve 14, a second filling shuttle valve 15, a filling pressure control valve 16, a shuttle valve 17, etc.

[0053] The oil inlet and outlet ends of the first one-way valve 11 are connected to the oil receiving port (P port) and the steering oil delivery port (A port) respectively. The two ends of the first electromagnetic switch valve 12 are connected to the oil outlet end of the first one-way valve 11 and the steering filling oil port (A1 port) respectively. One end of the second electromagnetic switch valve 13 is connected to the steering filling oil port (A1 port), and the other end is connected to the oil return port (T port).

[0054] The first electromagnetic switch valve 12 and the second electromagnetic switch valve 13 are normally in the power-off state. In the power-off state, the oil circuits between the oil ports at both ends of the first electromagnetic switch valve 12 and the second electromagnetic switch valve 13 are connected. When the electromagnets of the first electromagnetic switch valve 12 and the second electromagnetic switch valve 13 are powered on, the oil circuits between the oil ports at both ends are cut off.

[0055] The oil receiving port (P port) is simultaneously connected to the hydraulic control end of the filling pressure control valve 16 and the oil inlet end of the first filling shuttle valve 14. The first filling end of the first filling shuttle valve 14 is connected to the steering filling oil port (A1 port), and the second filling end of the first filling shuttle valve 14 is connected to the oil inlet end of the second filling shuttle valve 15. The filling end of the second filling shuttle valve 15 is connected to the brake filling oil port.

[0056] The first oil inlet end of the shuttle valve 17 is connected to the LS1 oil port, and the oil outlet end is connected to the LS oil port.

[0057] The filling pressure control valve 16 is a two-position three-way valve, whose oil inlet end (E end) is connected to the hydraulic control end, the oil outlet end (F end) is connected to the second oil inlet end of the shuttle valve 17, the oil return end (G end) is connected to the oil return port (T port), and the oil outlet end (F end) is selectively connected to the oil inlet end (E end) or the oil return end (G end) and the oil outlet end (F end) is connected to the oil inlet end (E end) in normal state. The normal state of the filling pressure control valve 16 is that there is no pressure oil acting on its valve stem at its hydraulic control end, and the valve stem is in the right position in the figure.

[0058] Optionally, the load-sensitive filling valve further includes a first damping valve 19, and the first damping valve 19 is arranged on the connecting oil path between the second electromagnetic switch valve 13 and the oil return port (T port). When the steering filling oil port (A1 port) needs to be depressurized, the second electromagnetic switch valve 13 is powered off, and the oil in the steering filling oil port (A1 port) is depressurized through the second electromagnetic switch valve and the first damping valve. The first damping valve 19 is used to control the depressurization speed.

[0059] Optionally, the load-sensing filling valve further includes a second one-way valve 18, which is disposed on the connecting oil path between the oil receiving port (P port) and the oil inlet end of the first filling shuttle valve 16, the oil inlet end of the second one-way valve 18 is connected to the oil receiving port (P port), and the oil outlet end of the second one-way valve 18 is simultaneously connected to the oil inlet end of the first filling shuttle valve 14 and the hydraulic control end of the filling pressure control valve 16. The second one-way valve 18 is used to prevent oil backflow when there is no pressure oil input to the oil receiving port (P port).

[0060] Optionally, the load-sensitive filling valve further comprises a second damping valve 20, which is arranged in the oil path between the oil receiving port and the oil inlet end of the second one-way valve. The second damping valve 20 is used to control the filling speed to make the filling speed stable.

[0061] Optionally, the load-sensitive filling valve further includes a pressure switch 21, a first pressure sensor 22, and a second pressure sensor 23. The pressure detection end of the pressure switch 21 is connected to the oil receiving port (P port). The pressure detection end of the first pressure sensor 22 is connected to the oil outlet end of the first check valve 11, and the pressure detection end of the second pressure sensor 23 is connected to the steering filling oil port (A1 port). The pressure switch and each pressure sensor are used to detect the pressure of each oil port in the load-sensitive filling valve, so as to perform corresponding logic control when the load-sensitive filling valve is applied to the hydraulic system.

[0062] The pressure switch 21 is used to control the opening and closing of the first electromagnetic switch valve 12. When the pressure of the oil receiving port (P port) is lower than the set value, the pressure switch 21 is disconnected, the first electromagnetic switch valve 12 is powered off, and the steering accumulator connected to the steering filling oil port (A port) can supply oil to the steering oil delivery port (A port) through the first electromagnetic switch valve 12 to realize emergency steering oil supply. The first pressure sensor and the second pressure sensor are used to detect the pressure of the oil receiving port (A port) and the steering filling oil port (A port) to realize the normal system and the high and low pressure monitoring and alarm of the steering accumulator.

[0063] Optionally, the brake filling oil port includes a first brake filling oil port (B1 port) and a second brake filling oil port (B2 port); the two filling ends of the second brake filling shuttle valve 15 are correspondingly connected to the first brake filling oil port (B1 port) and the second brake filling oil port (B2 port). The first brake filling oil port (B1 port) and the second brake filling oil port (B2 port) can be used to supply oil to the working oil inlets of different modules in the hydraulic brake control unit and to fill the brake accumulators of the corresponding modules.

[0064] Optionally, the load-sensing filling valve 10 further has a third brake filling oil port (B3 port), which is connected to the second filling end of the first filling shuttle valve 14. The third brake filling oil port (B3 port) can be connected to the working oil inlet of the third brake module in the hydraulic brake control unit 34 for oil supply and to fill the third brake accumulator 63.

[0065] Embodiment 2.

[0066] like Figure 3As shown, the steering and brake hydraulic system includes a hydraulic oil tank 31, a load-sensitive variable pump 39 whose oil suction port is connected to the hydraulic oil tank, a steering cylinder 33, a hydraulic steering control unit 50 for controlling and driving the steering cylinder 33, a hydraulic brake control unit 34, a steering accumulator 40, a brake accumulator 60, and a load-sensitive filling valve 10. The pump port of the load-sensitive variable pump is connected to the oil receiving port (P port) through a high-pressure filter 32. The steering oil delivery port (A port) is connected to the working oil inlet of the hydraulic steering control unit 50. The steering accumulator 40 is connected to the steering filling oil port (A1 port), and the return oil port (T port) is connected to the hydraulic oil tank 31 through the return oil filter 37. The steering load signal output end of the hydraulic steering control unit 50 is connected to the LS1 oil port, and the LS oil port is connected to the control oil port of the load-sensitive variable pump 39.

[0067] In this embodiment, the hydraulic steering control unit 50 is composed of a steering gear 51 and a flow amplification valve 52 , and the steering oil delivery port (port A) is connected to the working oil inlet of the flow amplification valve 52 .

[0068] The brake accumulator 60 includes a first brake accumulator 61 , a second brake accumulator 62 , and a third brake accumulator 63 .

[0069] The working oil inlet of the hydraulic brake control unit 34 includes a first brake oil inlet, a second brake oil inlet, and a third brake oil inlet.

[0070] The first brake oil inlet and the first brake accumulator 61 are connected to the first brake filling oil port (B1 port); the second brake oil inlet and the second brake accumulator 62 are connected to the second brake filling oil port (B2 port); the third brake oil inlet and the third brake accumulator 63 are connected to the third brake filling oil port (B3 port).

[0071] In the hydraulic brake control unit 34, the first brake oil inlet port can be used to supply oil to the auxiliary brake module, the second brake oil inlet port can be used to supply oil to the front axle brake module of the mining dump truck, and the third brake oil inlet port can be used to supply oil to the rear axle brake module of the mining dump truck.

[0072] The working principle of the steering and brake hydraulic system is as follows:

[0073] After the mining dump truck is started, the pressure oil output by the load-sensitive variable pump 39 is transmitted to the load-sensitive filling valve 10, and the pressure oil is fed back to the control port of the load-sensitive variable pump 39 through the LS loop. The displacement of the load-sensitive variable pump 39 gradually increases, and each accumulator is quickly filled with liquid. The filling pressure value is determined by the filling pressure control 16. When the pressure in each accumulator is lower than the lower limit pressure of the filling pressure control valve 16, the pressure of each accumulator is transmitted to the control port of the load-sensitive variable pump 39 through the oil inlet end (E end), the oil outlet end (F end) and the shuttle valve 17 of the filling pressure control valve 16, and the load-sensitive variable pump 39 fills each accumulator. When the pressure in each accumulator is higher than the upper limit pressure of the filling pressure control valve 16, the filling pressure control valve 16 is reversed, and its oil outlet end (F end) is connected to the oil return end (G end), and the shuttle valve 17 does not output the accumulator pressure signal. The load-sensitive variable pump 39 works at the minimum displacement to keep its pump port in a high-pressure state.

[0074] When the mining dump truck is in driving state and there is a steering demand, the steering load pressure is transmitted to the control port of the load-sensitive variable pump 39 through the LS load signal port of the steering gear 51 and the shuttle valve 17 in the load-sensitive filling valve 10. The load-sensitive variable pump 39 provides pressure oil of the docking flow according to the feedback signal to form the steering.

[0075] The mining dump truck is in an emergency steering state: when the power source fails, the load-sensitive variable pump 39 stops outputting pressure oil, the pressure at the oil receiving port (P port) is lower than the set value, the pressure switch 21 is disconnected, the electromagnet D1 of the first electromagnetic switch valve 12 is powered off, and the pressure oil of the steering accumulator 40 is output from the steering oil delivery port (A port) to the hydraulic steering control unit 50 through the first electromagnetic switch valve 12 to supply oil for emergency steering. Since the steering accumulator 40 does not supply oil to the outside when the vehicle is in normal use, it always maintains a high pressure state, so it can ensure that the pressure oil inside it can meet the needs of emergency steering, ensuring driving safety.

[0076] When the mining dump truck is in system maintenance, the truck is stopped and the power is cut off, the electromagnet D2 of the second electromagnetic switch valve 13 is powered off, the second electromagnetic switch valve 13 is turned on, and the pressure oil in the steering accumulator 40 flows back to the hydraulic oil tank 31 through the second electromagnetic switch valve 13 and the first damping valve 19, thereby depressurizing the hydraulic steering system.

[0077] Driving, parking and emergency braking of mining dump trucks: By operating the brake switch in the cab, the pressure oil in each brake accumulator is provided to each module in the hydraulic brake control unit 34 to realize the braking function of each brake module.

[0078] In this embodiment, the load-sensitive filling valve 10 is matched with the load-sensitive variable pump 39 and the load-sensitive steering gear 51 in the system. The flow and pressure required for hydraulic braking and hydraulic steering are transmitted to the load-sensitive variable pump 39 through the load-sensitive signal. The load-sensitive variable pump 39 adjusts the pressure and displacement at any time to realize oil supply on demand and achieve energy saving. The load-sensitive filling valve 10 is highly integrated with fewer pipeline connections, which improves the reliability of the system and the convenience of layout. The pressure oil in the steering accumulator 40 is only used for emergency steering oil supply to the hydraulic steering control unit 50 when the first solenoid switch valve 12 is powered off, avoiding the problem of insufficient pressure during emergency steering oil supply.

[0079] Embodiment three.

[0080] This embodiment provides a mining dump truck, which has the load-sensitive filling valve 10 of the first embodiment, or has the steering and braking hydraulic system of the second embodiment.

Claims

1. A load-sensitive filling valve, characterized in that: With: oil receiving port, LS oil port, LS1 oil port, steering oil delivery port, steering oil filling port, brake oil filling port, oil return port; It includes: a first one-way valve, a first electromagnetic switch valve and a second electromagnetic switch valve which are normally cut off, a first liquid-filling shuttle valve, a second liquid-filling shuttle valve, a shuttle valve, and a liquid-filling pressure control valve; The oil inlet and outlet ends of the first one-way valve are connected to the oil receiving port and the steering oil delivery port; the two ends of the first electromagnetic switch valve are connected to the oil outlet end of the first one-way valve and the steering oil filling port; one end of the second electromagnetic switch valve is connected to the steering oil filling port, and the other end is connected to the oil return port; The oil receiving port is simultaneously connected to the hydraulic control end of the filling pressure control valve and the oil inlet end of the first filling shuttle valve; the first filling end of the first filling shuttle valve is connected to the steering filling oil port, the second filling end of the first filling shuttle valve is connected to the oil inlet end of the second filling shuttle valve; the filling end of the second filling shuttle valve is connected to the brake filling oil port; The first oil inlet end of the shuttle valve is connected to the LS1 oil port, and the oil outlet end is connected to the LS oil port; The filling pressure control valve is a two-position three-way valve, whose oil inlet end is connected to the hydraulic control end, the oil outlet end is connected to the second oil inlet end of the shuttle valve, the oil return end is connected to the oil return port, and the oil outlet end is selectively connected to the oil inlet end or the oil return end and is connected to the oil inlet end under normal conditions.

2. The load-sensing filling valve according to claim 1, characterized in that: The load-sensitive filling valve further includes a first damping valve, which is arranged on the communicating oil path between the second electromagnetic switch valve and the oil return port.

3. The load-sensing filling valve according to claim 1, characterized in that: The load-sensitive filling valve also includes a second one-way valve, which is arranged in the connecting oil path between the oil receiving port and the oil inlet end of the first filling shuttle valve, and the oil inlet end is connected to the oil receiving port, and the oil outlet end is simultaneously connected to the oil inlet end of the first filling shuttle valve and the hydraulic control end of the filling pressure control valve.

4. The load-sensing filling valve according to claim 1, characterized in that: The load-sensing filling valve further comprises a second damping valve, which is arranged on the communicating oil path between the oil receiving port and the oil inlet end of the second one-way valve.

5. The load-sensing filling valve according to claim 1, characterized in that: The load-sensitive filling valve also includes a pressure switch, a first pressure sensor, and a second pressure sensor. The pressure detection end of the pressure switch is connected to the oil receiving port; the pressure detection end of the first pressure sensor is connected to the oil outlet end of the first one-way valve, and the pressure detection end of the second pressure sensor is connected to the steering filling oil port.

6. The load-sensing filling valve according to any one of claims 1 to 5, characterized in that: The brake filling oil port comprises a first brake filling oil port and a second brake filling oil port; and the two filling ends of the second filling shuttle valve are correspondingly connected to the first brake filling oil port and the second brake filling oil port.

7. The load-sensing filling valve according to claim 6, characterized in that: The load-sensing filling valve also has a third brake filling oil port, and the third brake filling oil port is connected to the second filling end of the first filling shuttle valve.

8. A steering and braking hydraulic system, comprising a hydraulic oil tank, a load-sensitive variable displacement pump whose oil suction port is connected to the hydraulic oil tank, a steering cylinder, a hydraulic steering control unit for controlling and driving the steering cylinder, a hydraulic brake control unit, a steering accumulator, and a brake accumulator, characterized in that: The system also includes a load-sensitive filling valve according to any one of claims 1 to 5, the oil receiving port is connected to the pump port of the load-sensitive variable pump, the steering oil delivery port is connected to the working oil inlet of the hydraulic steering control unit, the steering accumulator is connected to the steering filling oil port, the working oil inlet of the hydraulic brake control unit and the brake accumulator are both connected to the brake filling oil port, the oil return port is connected to the hydraulic oil tank via a return oil filter, the load signal output end of the hydraulic steering control unit is connected to the LS1 oil port, and the LS oil port is connected to the control oil port of the load-sensitive variable pump.

9. The steering and braking hydraulic system according to claim 8, characterized in that: The system also includes a third brake accumulator; The load-sensing filling valve also has a third brake filling oil port connected to the second filling end of the first filling shuttle valve; The brake filling oil port comprises a first brake filling oil port and a second brake filling oil port corresponding to the two filling ends of the second filling shuttle valve; The working oil inlet of the hydraulic brake control unit includes a first brake oil inlet, a second brake oil inlet, and a third brake oil inlet; The brake accumulator comprises a first brake accumulator and a second brake accumulator; The first brake oil inlet and the first brake accumulator are connected to the first brake filling oil port; The second brake oil inlet port and the second brake accumulator are connected to the second brake filling oil port; The third brake oil inlet port and the third brake accumulator are connected to the third brake filling oil port.

10. A mining dump truck, characterized in that: A load sensing filling valve according to any one of claims 1 to 5, or a steering and braking hydraulic system according to claim 8 or 9.

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