Hydraulic brake system of mining dump truck and mining dump truck
By using a parallel design of steering accumulator and braking accumulator, the hydraulic pump works in conjunction with the first steering accumulator to provide a stable and reliable braking system for mining dump trucks, solving the problem of braking system failure and achieving rapid braking and improved safety.
Patent Information
- Application Number
- CN202423128053.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2034-12-17
AI Technical Summary
In harsh environments, the hydraulic braking system of mining dump trucks is prone to failure due to damage to the brake accumulator or air leakage, which affects safety and efficiency.
The system adopts a parallel design of steering accumulator and brake accumulator. The hydraulic pump works in conjunction with the first steering accumulator to supply pressurized oil to the front and rear brakes. During emergency braking, the hydraulic pump, the first steering accumulator, and the brake accumulator jointly provide pressurized oil. An emergency braking and parking brake mechanism is set up, and one emergency braking accumulator is removed to improve utilization efficiency.
It improves braking stability and reliability, enables rapid braking, reduces braking distance, enhances safety and fuel efficiency, reduces vehicle weight, and increases design flexibility.
Smart Images
Figure CN223702552U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to engineering machinery technical field especially a kind of hydraulic braking system of mine dump truck and mine dump truck. BACKGROUND
[0002] Mine dump truck is widely used in large-scale mining machinery operation, mainly used for transporting mineral resources such as ore, coal and sandstone, effectively improve transportation efficiency and production benefit. To ensure the safety performance in the process of vehicle driving, hydraulic braking system is usually used. However, the mining operation environment is poor, which can easily cause problems such as loosening, air leakage and insufficient pressure of brake accumulator, and further cause brake system failure, reduce work efficiency, even cause vehicle out of control, lead to serious traffic accidents, threaten the life safety of driver and other personnel.
[0003] Figure 1 is a kind of schematic diagram of existing hydraulic braking system of mine dump truck, please refer to Figure 1 , existing mine dump truck usually adopts the way of series connection of variable pump and brake accumulator to provide pressure oil for brake system, including variable pump 1, steering accumulator 2, brake pedal 3, front axle brake 4, rear axle brake 5, parking brake 6, brake accumulator 7, emergency brake accumulator 8, emergency brake reversing solenoid valve 9, brake valve group 10, parking brake reversing solenoid valve 11 and steering valve group 12. The hydraulic braking system is provided with pressure oil by variable pump 1, brake accumulator 7 and emergency brake accumulator 8. In normal driving, when the driver steps on brake pedal 3, the pressure oil in variable pump 1 and brake accumulator 7 enters front and rear axle brakes 4, 5 through reversing valve, so as to realize the braking of vehicle. When the vehicle needs emergency braking, brake pressure oil is provided by variable pump 1, emergency brake accumulator 8 and brake accumulator 7 together.
[0004] When brake accumulator 7 or emergency brake accumulator 8 is damaged or leaks, or when any one of brake accumulator 7 is damaged or leaks, etc. during driving, the other accumulators in series cannot provide more pressure oil, which adversely affects the performance of vehicle brake system, and potentially causes safety hazards.
[0005] In addition, the accumulators of steering system and brake system are in series, which also reduces the utilization efficiency of accumulator. INVENTION CONTENTS
[0006] Therefore, the utility model provides a kind of hydraulic braking system of mine dump truck, which is safe and reliable in braking, and can improve the utilization efficiency of steering accumulator and brake accumulator, to solve the problems of brake system abnormality, failure or poor braking effect caused by accumulator damage, air leakage, etc. during driving of mine dump truck.
[0007] This utility model provides a hydraulic braking system for a mining dump truck, including a steering valve assembly, a hydraulic pump, a first steering accumulator, a brake valve assembly, a pedal valve, a first brake accumulator, a second brake accumulator, a front brake, and a rear brake. The inlet P and filling port Ac2 of the steering valve assembly are both connected to the outlet Pb. The outlet of the hydraulic pump is connected to the inlet P of the steering valve assembly, and the inlet of the hydraulic pump is connected to an oil tank. The first steering accumulator is connected to the filling port Ac2 of the steering valve assembly, and the outlet Pb of the steering valve assembly is connected to the inlet P of the brake valve assembly. The inlet P of the brake valve assembly and the brake port Pb... 1. Brake fluid port P2 is open; the filling port ACF of the brake valve assembly is open to brake fluid port P1; the filling port ACR of the brake valve assembly is open to brake fluid port P2; the brake fluid port P1 of the brake valve assembly is connected to the inlet port P1 of the pedal valve; the brake fluid port P2 of the brake valve assembly is connected to the inlet port P2 of the pedal valve; the filling port ACF of the brake valve assembly is connected to the first brake accumulator; the filling port ACR of the brake valve assembly is connected to the second brake accumulator; the working port A1 of the pedal valve is connected to the rodless chamber of the front brake; the working port A2 of the pedal valve is connected to the rodless chamber of the rear brake.
[0008] Furthermore, the brake valve assembly includes an emergency brake reversing valve and a first shuttle valve. The inlet of the emergency brake reversing valve is connected to the outlet of the first shuttle valve. The working port of the emergency brake reversing valve is connected to the control port Px of the brake valve assembly. The control port Px of the brake valve assembly is connected to the pilot port Pp of the pedal valve. One inlet of the first shuttle valve is connected to the filling port acf and the inlet P of the brake valve assembly, and the other inlet of the first shuttle valve is connected to the filling port acr and the inlet P of the brake valve assembly.
[0009] Furthermore, it also includes a parking brake, and the brake valve assembly is further provided with a parking brake reversing valve. The oil inlet of the parking brake reversing valve is connected to the oil inlet P of the brake valve assembly, and the working oil port of the parking brake reversing valve is connected to the control port Pb of the brake valve assembly. The control port Pb of the brake valve assembly is connected to the rod chamber of the parking brake.
[0010] Furthermore, the brake valve assembly is also provided with a first pressure reducing valve, which is located in the oil line between the oil inlet P of the brake valve assembly and the parking brake reversing valve.
[0011] Further, the brake valve group is further provided with an auxiliary brake reversing valve and a second shuttle valve, one oil inlet of the second shuttle valve is communicated with the oil inlet P3 of the brake valve group, the other oil inlet of the second shuttle valve is communicated with the working oil port of the auxiliary brake reversing valve, the oil outlet of the second shuttle valve is communicated with the control port Pr of the brake valve group, the oil inlet of the auxiliary brake reversing valve is communicated with the filling port acf and the oil inlet P of the brake valve group; the oil inlet P3 of the brake valve group is connected to the working oil port A2 of the pedal valve, and the control port Pr of the brake valve group is connected to the rodless cavity of the rear brake.
[0012] Further, the oil circuit between the brake reversing valve and the second shuttle valve is further connected with a second pressure reducing valve and a first check valve in parallel; the oil outlet of the second pressure reducing valve is communicated with the oil inlet of the first check valve and the oil outlet of the second shuttle valve, and the oil inlet of the second pressure reducing valve is communicated with the oil outlet of the first check valve and the working oil port of the auxiliary brake reversing valve.
[0013] Further, a second steering accumulator connected to the oil supply port Ac1 of the steering valve group is further included, the oil supply port Ac1 of the steering valve group is communicated with the oil outlet P1, and the oil outlet P1 of the steering valve group is connected to the steering oil cylinder.
[0014] Further, the steering valve group is further provided with a second check valve and a third check valve, the second check valve and the third check valve are arranged on the oil circuit between the oil inlet P and the oil outlet P1 of the steering valve group, and the communication position of the oil circuit between the oil supply port Ac2 and the control port Pb of the steering valve group and the oil circuit between the oil inlet P and the oil outlet P1 of the steering valve group is located between the second check valve and the third check valve.
[0015] The utility model further provides a mine dump truck, including above-mentioned mine dump truck's hydraulic braking system.
[0016] In summary, the mine dump truck's hydraulic braking system and mine dump truck of the utility model have the following beneficial effects:
[0017] 1, through the hydraulic pump, steering accumulator and brake accumulator cooperate, synchronous for front, rear brake supply pressure oil, improved the stability and reliability of vehicle braking, and realized the quick brake, reduced the distance required for braking.
[0018] 2, the first steering accumulator and the second steering accumulator are connected in parallel to supply oil to the steering oil cylinder, the first steering accumulator and the hydraulic pump supply oil to the brake system together, and can also provide the filling function for the brake accumulator, thereby improving the utilization efficiency of each accumulator.
[0019] 3. The first brake accumulator and the second brake accumulator are connected in parallel and supply oil to the emergency brake at the same time as the first steering accumulator, thereby improving the safety factor of the vehicle.
[0020] 4. The emergency brake mechanism is provided, so that the brake system failure caused by damage, air leakage and other reasons of the brake accumulator is avoided.
[0021] 5. Compared with the prior art, one accumulator for emergency braking is removed, so that the weight of the vehicle is reduced, flexibility, fuel efficiency and transportation capacity are improved, and the released space can be used to install other components, thereby improving design flexibility.
[0022] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, the content of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 is a schematic diagram of a hydraulic braking system of a mine dump truck of the prior art.
[0024] Figure 2 is a schematic diagram of a hydraulic braking system of a mine dump truck of the preferred embodiment of the present application.
[0025] Figure 3 is a schematic diagram of a brake valve group in the hydraulic braking system of the mine dump truck of the preferred embodiment of the present application. DETAILED DESCRIPTION
[0026] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined application purpose, the present application is described in detail as follows in combination with the drawings and the preferred embodiments.
[0027] Figure 2 is a schematic diagram of a hydraulic braking system of a mine dump truck of the preferred embodiment of the present application, please refer to Figure 2 , Figure 3 is a schematic diagram of a brake valve group in the hydraulic braking system of the mine dump truck of the preferred embodiment of the present application, please refer to Figure 2 and Figure 3 , the hydraulic braking system of the mine dump truck of the present embodiment comprises a steering valve group 10, a hydraulic pump 20, a first steering accumulator 31, a brake valve group 40, a pedal valve 50, a first brake accumulator 61, a second brake accumulator 62, a front brake 70 and a rear brake 80.
[0028] The oil inlet P of the steering valve group 10 and the oil filling port Ac2 are communicated with the oil outlet Pb, that is, the oil inlet P of the steering valve group 10 is communicated with the oil outlet Pb of the steering valve group 10 through an oil path inside the steering valve group 10, and the oil filling port Ac2 of the steering valve group 10 is communicated with the oil outlet Pb of the steering valve group 10 through another oil path inside the steering valve group 10. The oil paths can have a part as a common oil path, such as the part communicated with the oil outlet Pb of the steering valve group 10. The structures inside the valve group are described similarly below. The hydraulic pump 20 is a variable pump, the oil outlet of the hydraulic pump 20 is connected to the oil inlet P of the steering valve group 10 through an oil pipe, and the oil inlet of the hydraulic pump 20 is connected to the oil tank 21 through an oil pipe; the first steering accumulator 31 is connected to the oil filling port Ac2 of the steering valve group 10 through an oil pipe, and the oil outlet Pb of the steering valve group 10 is connected to the oil inlet P of the brake valve group 40 through an oil pipe.
[0029] The oil inlet P of the brake valve group 40 is unidirectionally communicated with the brake oil port P1 and the brake oil port P2, that is, the oil inlet P of the brake valve group 40 is unidirectionally communicated with the brake oil port P1 of the brake valve group 40 through an oil path inside the brake valve group 40, that is, the hydraulic oil can only flow from the oil inlet P to the brake oil port P1. The flow direction of the hydraulic oil can be controlled by setting a valve capable of controlling the flow direction of the hydraulic oil, such as a check valve and a relief valve. Similarly, the oil inlet P of the brake valve group 40 is unidirectionally communicated with the brake oil port P2 of the brake valve group 40 through an oil path inside the brake valve group 40. In this embodiment, the oil inlet P of the brake valve group 40 is communicated with the main oil path 400 inside the brake valve group 40, and the end of the main oil path 400 away from the oil inlet P of the brake valve group 40 is divided into the first oil path 401 and the second oil path 402, which are respectively communicated with the brake oil port P1 and the brake oil port P2 of the brake valve group 40. A check valve is arranged on each of the main oil path 400, the first oil path 401 and the second oil path 402.
[0030] The oil filling port acf of the brake valve group 40 is communicated with the brake oil port P1, and the oil filling port acr of the brake valve group 40 is communicated with the brake oil port P2. In this embodiment, the oil filling port acf of the brake valve group 40 is communicated with the first oil path 401 through the third oil path 403, and then communicated with the brake oil port P1 of the brake valve group 40 through the first oil path 401; the oil filling port acr of the brake valve group 40 is communicated with the second oil path 402 through the fourth oil path 404, and then communicated with the brake oil port P2 of the brake valve group 40 through the second oil path 402.
[0031] The brake oil port P1 of the brake valve group 40 is connected to the oil inlet P1 of the pedal valve 50 through an oil pipe, the brake oil port P2 of the brake valve group 40 is connected to the oil inlet P2 of the pedal valve 50 through an oil pipe, the oil filling port acf of the brake valve group 40 is connected to the first brake accumulator 61 through an oil pipe, and the oil filling port acr of the brake valve group 40 is connected to the second brake accumulator 62 through an oil pipe.
[0032] The pedal valve 50 includes two synchronous three-position three-way valves, and a mechanical brake pedal (not shown in the figure) is arranged on the pedal valve 50. The inlet port P1 of the pedal valve 50 is connected to the brake oil port P1 of the brake valve group 40, and the inlet port P2 of the pedal valve 50 is connected to the brake oil port P2 of the brake valve group 40. The working oil port A1 of the pedal valve 50 is connected to the rodless cavity of the front brake 70, and the working oil port A2 of the pedal valve 50 is connected to the rodless cavity of the rear brake 80. The rod cavities of the front brake 70 and the rear brake 80 are provided with springs.
[0033] The hydraulic brake system of the mine dump truck can supply pressure oil to the front brake 70 and the rear brake 80 synchronously by the hydraulic pump 20, the first steering accumulator 31, the first brake accumulator 61 and the second brake accumulator 62 during braking, thereby improving the stability and reliability of vehicle braking, achieving rapid braking, and reducing the required braking distance.
[0034] Further, the emergency brake reversing valve 411 and the first shuttle valve 412 are arranged in the brake valve group 40. The inlet port of the emergency brake reversing valve 411 is communicated with the outlet port of the first shuttle valve 412, the working oil port of the emergency brake reversing valve 411 is communicated with the control port Px of the brake valve group 40, and the return oil port of the emergency brake reversing valve 411 is connected to the return oil tank 21. The control port Px of the brake valve group 40 is connected to the pilot port Pp of the pedal valve 50 through an oil pipe, one of the inlet ports of the first shuttle valve 412 is communicated with the filling port acf and the inlet port P of the brake valve group 40, and the other inlet port of the first shuttle valve 412 is communicated with the filling port acr and the inlet port P of the brake valve group 40. Specifically, one of the inlet ports of the first shuttle valve 412 is communicated to the third oil path 403 through an oil path, and the other inlet port is communicated to the fourth oil path 404 through an oil path, and the first shuttle valve 412 can selectively communicate the pressure oil with higher oil pressure in the third oil path 403 and the fourth oil path 404 to the emergency brake reversing valve 411.
[0035] In the embodiment, the emergency brake reversing valve 411 is a two-position three-way electromagnetic reversing valve, and when the electric control end of the emergency brake reversing valve 411 is powered, the inlet port and the working oil port are communicated, and when the electric control end of the emergency brake reversing valve 411 loses power, the working oil port and the return oil port are communicated.
[0036] When the pressure of the first brake accumulator 61 and / or the second brake accumulator 62 is lower than a preset value (e.g. 90 bar) during the driving of the vehicle, the emergency braking mechanism will be triggered. To ensure the vehicle to stop quickly, the on-board controller can control the emergency braking directional electromagnetic valve 8 to be powered and reversed, at this time, the pressure oil pumped by the hydraulic pump 20, the pressure oil in the first steering accumulator 31 and the pressure oil in the first brake accumulator 61 or the second brake accumulator 62 jointly act on the pilot oil port Pp of the pedal valve 50, forcing the pedal valve 50 to move and reverse. Subsequently, the pressure oil enters the front and rear brakes 70, 80, causing the vehicle to brake urgently and eventually stop. Compared with the prior art, the process shortens the emergency braking stopping time, realizes the rapid braking in the emergency state, and the first shuttle valve 412 can selectively conduct the brake accumulator with higher pressure, avoiding the failure of the brake system caused by the damage, air leakage and other reasons of the brake accumulator.
[0037] Further, in order to enable the parking brake of the vehicle when it is parked, prevent the vehicle from sliding due to its own weight or external force, the hydraulic braking system of the mining dump truck further comprises a parking brake 90. The brake valve group 40 is further provided with a parking brake directional valve 421, the inlet of the parking brake directional valve 421 is in communication with the inlet P of the brake valve group 40, and in the embodiment, the inlet of the parking brake directional valve 421 is connected to the main oil line 400 through an oil line and the connection point is located behind the one-way valve on the main oil line 400, the working oil port of the parking brake directional valve 421 is in communication with the control port Pb of the brake valve group 40, and the return oil port of the parking brake directional valve 421 is connected to the return tank 21. The control port Pb of the brake valve group 40 is connected to the rod cavity of the parking brake 90 through an oil pipe, and the rodless cavity of the parking brake 90 is provided with a spring.
[0038] The parking brake directional valve 421 is a two-position three-way electromagnetic directional valve, when the electric control end of the parking brake directional valve 421 is powered, the working oil port and the return oil port of the parking brake directional valve 421 are in communication, and when the electric control end of the parking brake directional valve 421 loses power, the inlet and the working oil port of the parking brake directional valve 421 are in communication. When the parking brake directional valve 421 loses power, the valve core of the parking brake directional valve 421 moves to the normal position, and the oil in the parking brake 90 returns to the return tank 21 through the parking brake directional valve 421, at this time, the oil in the rod cavity of the parking brake 90 is released, and the parking brake 90 extends under the action of the spring force to implement the brake. When the parking brake directional valve 421 is powered, the pressure oil in the hydraulic pump 20 and the first steering accumulator 31 flows into the parking brake 90 through the parking brake directional valve 421 and the control port Pb of the brake valve group 40, thereby releasing the parking brake.
[0039] Further, the first pressure reducing valve 423 is arranged on the oil passage between the oil inlet P of the brake valve group 40 and the parking brake reversing valve 421, and specifically on the oil passage between the parking brake reversing valve 421 and the main oil passage 400.
[0040] Further, the parking brake shuttle valve 422 is arranged on the oil passage between the parking brake reversing valve 421 and the control port Pb of the brake valve group 40. The oil outlet of the parking brake shuttle valve 422 is connected to the control port Pb of the brake valve group 40. One of the oil inlets of the parking brake shuttle valve 422 is connected to the working oil port of the parking brake reversing valve 421, and the other oil inlet of the parking brake shuttle valve 422 is connected to a control port of the brake valve group 40. Through the control port and the parking brake shuttle valve 422, another oil supply method for the parking brake 90 can be provided.
[0041] Further, since the mine dump truck has a large load, the loading and unloading of materials will generate a large impact on the vehicle, and the separate parking brake will damage the parking brake 90. Therefore, the auxiliary brake reversing valve 431 and the second shuttle valve 432 are arranged in the brake valve group 40. One of the oil inlets of the second shuttle valve 432 is connected to the oil inlet P3 of the brake valve group 40, and the other oil inlet of the second shuttle valve 432 is connected to the working oil port of the auxiliary brake reversing valve 431. The oil outlet of the second shuttle valve 432 is connected to the control port Pr of the brake valve group 40. The oil inlet of the auxiliary brake reversing valve 431 is connected to the oil passage between the first shuttle valve 412 and the third oil passage 403. The oil return port of the auxiliary brake reversing valve 431 is connected to the oil tank 21. The oil inlet P3 of the brake valve group 40 is connected to the working oil port A2 of the pedal valve 50 through an oil pipe. The control port Pr of the brake valve group 40 is connected to the rodless chamber of the rear brake 80 through an oil pipe.
[0042] The auxiliary brake reversing valve 431 is a two-position three-way electromagnetic reversing valve. When the electric control end of the auxiliary brake reversing valve 431 is powered, the oil inlet and the working oil port of the auxiliary brake reversing valve 431 are connected. When the electric control end of the auxiliary brake reversing valve 431 loses power, the working oil port and the oil return port of the auxiliary brake reversing valve 431 are connected. When the auxiliary brake reversing valve 431 loses power, the valve core of the auxiliary brake reversing valve 431 moves to the normal position, and the oil in the rear brake 80 returns to the oil tank 21 through the auxiliary brake reversing valve 431 to release the brake. When the auxiliary brake reversing valve 431 is powered, the pressure oil in the hydraulic pump 20, the first steering accumulator 31 and the first brake accumulator 61 flows into the rear brake 80 through the control port Pr of the brake valve group 40, so as to brake the rear brake 80 to reduce the impact on the vehicle during loading and unloading of materials.
[0043] Further, to control the flow and pressure on the oil path between the auxiliary brake reversing valve 431 and the second shuttle valve 432, a second pressure reducing valve 433 and a first check valve 434 are also connected in parallel on the oil path between the brake reversing valve 431 and the second shuttle valve 432; the oil outlet of the second pressure reducing valve 433 is communicated with the oil inlet of the first check valve 434 and the oil outlet of the second shuttle valve 432, and the oil inlet of the second pressure reducing valve 433 is communicated with the oil outlet of the first check valve 434 and the working oil port of the auxiliary brake reversing valve 431.
[0044] The hydraulic braking system of the mine dump truck further comprises a second steering accumulator 32, which is connected to an oil supply port Ac1 of the steering valve group 10, the oil supply port Ac1 of the steering valve group 10 is communicated with an oil outlet port P1, and the oil outlet port P1 of the steering valve group 10 is connected to a steering oil cylinder (not shown in the figure). When the mine dump truck needs to realize steering action, the hydraulic pump 2, the first steering accumulator 31 and the second steering accumulator 32 jointly provide pressure oil for the steering oil cylinder.
[0045] Further, the steering valve group 10 further comprises a second check valve 111 and a third check valve 112, which are arranged on the oil path between the oil inlet port P and the oil outlet port P1 of the steering valve group 10, and the communication position of the oil path between the oil supply port Ac2 and the control port Pb of the steering valve group 10 and the oil path between the oil inlet port P and the oil outlet port P1 of the steering valve group 10 is located between the second check valve 111 and the third check valve 112.
[0046] The hydraulic braking system of the mine dump truck has the following beneficial effects:
[0047] 1. The hydraulic pump, the steering accumulator and the brake accumulator work cooperatively to synchronously supply pressure oil for the front and rear brakes, thereby improving the stability and reliability of vehicle braking and realizing rapid braking and reducing the required braking distance.
[0048] 2. The first steering accumulator and the second steering accumulator are connected in parallel to supply oil for the steering oil cylinder, the first steering accumulator and the hydraulic pump supply oil for the braking system together, and can also provide oil charging function for the brake accumulator, thereby improving the utilization efficiency of each accumulator.
[0049] 3. The first brake accumulator and the second brake accumulator are connected in parallel and supply oil for the emergency brake at the same time as the first steering accumulator, thereby improving the safety factor of the vehicle.
[0050] 4. The emergency braking mechanism is arranged to avoid failures such as failure of the braking system caused by damage, air leakage and the like of the brake accumulator.
[0051] 5. Compared with the prior art, removing an accumulator for emergency braking can reduce the weight of the vehicle, improve flexibility, fuel efficiency and transport capacity. At the same time, the released space can be used to install other components, improving design flexibility.
[0052] The utility model also relates to a mine dump truck, including the hydraulic brake system of mine dump truck above-mentioned. The other structure of this mine dump truck is known to those skilled in the art, and will not be repeated here.
[0053] The above is only the preferred embodiment of the utility model, and does not limit the utility model in any form. Although the utility model has been disclosed as above, it is not intended to limit the utility model. Any skilled person in the art can make some changes or modifications to the disclosed technical content without departing from the scope of the utility model technical scheme. Any simple modification, equivalent change and modification of the above embodiment according to the technical essence of the utility model still belong to the scope of the utility model technical scheme.
Claims
1. A hydraulic braking system for a mining dump truck, characterized in that, The steering valve group (10), the hydraulic pump (20), the first steering accumulator (31), the brake valve group (40), the pedal valve (50), the first brake accumulator (61), the second brake accumulator (62), the front brake (70) and the rear brake (80) are included. The oil inlet P and the liquid filling port Ac2 of the steering valve group (10) are communicated with the oil outlet Pb, the oil outlet of the hydraulic pump (20) is connected to the oil inlet P of the steering valve group (10), and the oil inlet of the hydraulic pump (20) is connected to the oil tank (21); the first steering accumulator (31) is connected to the liquid filling port Ac2 of the steering valve group (10), and the oil outlet Pb of the steering valve group (10) is connected to the oil inlet P of the brake valve group (40). The oil inlet P of the brake valve group (40) is communicated with the brake oil port P1 and the brake oil port P2, the liquid filling port acf of the brake valve group (40) is communicated with the brake oil port P1, and the liquid filling port acr of the brake valve group (40) is communicated with the brake oil port P2; the brake oil port P1 of the brake valve group (40) is connected to the oil inlet P1 of the pedal valve (50), the brake oil port P2 of the brake valve group (40) is connected to the oil inlet P2 of the pedal valve (50), the liquid filling port acf of the brake valve group (40) is connected to the first brake accumulator (61), and the liquid filling port acr of the brake valve group (40) is connected to the second brake accumulator (62). The working oil port A1 of the pedal valve (50) is connected to the rodless chamber of the front brake (70), and the working oil port A2 of the pedal valve (50) is connected to the rodless chamber of the rear brake (80).
2. The hydraulic braking system of a mining dump truck as claimed in claim 1, wherein, The emergency brake reversing valve (411) and the first shuttle valve (412) are arranged in the brake valve group (40), the oil inlet of the emergency brake reversing valve (411) is communicated with the oil outlet of the first shuttle valve (412), the working oil port of the emergency brake reversing valve (411) is communicated with the control port Px of the brake valve group (40), the control port Px of the brake valve group (40) is connected to the pilot oil port Pp of the pedal valve (50), one of the oil inlets of the first shuttle valve (412) is communicated with the liquid filling port acf and the oil inlet P of the brake valve group (40), and the other oil inlet of the first shuttle valve (412) is communicated with the liquid filling port acr and the oil inlet P of the brake valve group (40).
3. The hydraulic braking system of a mining dump truck as claimed in claim 1, wherein, The parking brake (90) is further included, and the parking brake reversing valve (421) is further arranged in the brake valve group (40), the oil inlet of the parking brake reversing valve (421) is communicated with the oil inlet P of the brake valve group (40), the working oil port of the parking brake reversing valve (421) is communicated with the control port Pb of the brake valve group (40), and the control port Pb of the brake valve group (40) is connected to the rod chamber of the parking brake (90).
4. The hydraulic braking system of a mining dump truck as claimed in claim 3, wherein, The brake valve group (40) is further provided with a first pressure reducing valve (423), which is arranged on an oil passage between an oil inlet P of the brake valve group (40) and the parking brake reversing valve (421).
5. The hydraulic braking system of a mining dump truck as claimed in claim 1, wherein, The brake valve group (40) is further provided with an auxiliary brake reversing valve (431) and a second shuttle valve (432), one oil inlet of the second shuttle valve (432) is communicated with the oil inlet P3 of the brake valve group (40), the other oil inlet of the second shuttle valve (432) is communicated with a working oil port of the auxiliary brake reversing valve (431), an oil outlet of the second shuttle valve (432) is communicated with a control port Pr of the brake valve group (40), and the oil inlet of the auxiliary brake reversing valve (431) is communicated with a filling port acf and the oil inlet P of the brake valve group (40); the oil inlet P3 of the brake valve group (40) is connected to a working oil port A2 of the pedal valve (50), and the control port Pr of the brake valve group (40) is connected to a rodless chamber of the rear brake (80).
6. The hydraulic braking system of a mining dump truck as claimed in claim 5, wherein, The oil passage between the brake reversing valve (431) and the second shuttle valve (432) is further provided with a second pressure reducing valve (433) and a first check valve (434) in parallel; an oil outlet of the second pressure reducing valve (433) is communicated with an oil inlet of the first check valve (434) and an oil outlet of the second shuttle valve (432), and an oil inlet of the second pressure reducing valve (433) is communicated with an oil outlet of the first check valve (434) and a working oil port of the auxiliary brake reversing valve (431).
7. The hydraulic braking system of a mining dump truck as claimed in claim 1, wherein, The hydraulic brake system further comprises a second steering accumulator (32) connected to an oil supply port Ac1 of the steering valve group (10), the oil supply port Ac1 of the steering valve group (10) is communicated with an oil outlet P1, and the oil outlet P1 of the steering valve group (10) is connected to a steering oil cylinder.
8. The hydraulic braking system of a mining dump truck as claimed in claim 7, wherein, The steering valve group (10) is further provided with a second check valve (111) and a third check valve (112), which are arranged on an oil passage between an oil inlet P and an oil outlet P1 of the steering valve group (10), and a communication position between an oil passage between an oil supply port Ac2 and a control port Pb of the steering valve group (10) and the oil passage between the oil inlet P and the oil outlet P1 of the steering valve group (10) is located between the second check valve (111) and the third check valve (112).
9. A mining dump truck, characterized in that The hydraulic brake system of the mine dump truck comprises the hydraulic brake system of the mine dump truck according to any one of claims 1 to 8.