Braking system for an engineering vehicle and a mining dump truck

Abstract

The application relates to the technical field of engineering machinery, in particular to a brake system for an engineering vehicle and a mine dump truck. The brake system for the engineering vehicle is characterized in that two oil inlets of a first hand self-switching valve are respectively communicated with a first electric proportional brake valve and a first pedal valve, and two oil inlets of a second hand self-switching valve are respectively communicated with a second electric proportional brake valve and a second pedal valve. Thus, the first hand self-switching valve can selectively communicate the first brake oil port A1 with the first electric proportional brake valve or the first pedal valve according to the driving state of the vehicle, and the second hand self-switching valve can selectively communicate the second brake oil port A2 with the second electric proportional brake valve or the second pedal valve according to the driving state of the vehicle, so that the brake purpose during manual driving or automatic driving of the vehicle can be achieved. The safety and reliability of driving are further improved. Meanwhile, the priority of manual brake operation is improved.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to a braking system for engineering vehicles and a mining dump truck. Background Technology

[0002] Mining dump trucks mainly consist of a diesel engine, generator, electric wheels, electronic control system, hydraulic system, frame, suspension, and cargo box. The hydraulic system is further divided into steering, lifting, and braking components. The braking hydraulic system is a crucial part of the entire vehicle. For safety and reliability, and to meet operational requirements, mining dump trucks typically have parking brakes, service brakes, loading brakes, and emergency brakes.

[0003] Currently, the hydraulic braking system of mining dump trucks generally consists of a hydraulic oil tank, hydraulic pump, filter, brake valve block, accumulator, brake pedal valve, relay valve, brake, brake disc, and hydraulic lines. When the operator presses the brake pedal valve, high-pressure oil is distributed through the brake valve block to the brake cylinder of the brake. The brake cylinder then pushes the friction pads against the brake disc, thus achieving braking.

[0004] Mining dump trucks are widely used in earthmoving and rock transportation in several major industries, including metallurgy, non-ferrous metals, chemicals, coal, building materials, and hydropower, and are currently the main transportation tool in large open-pit mines. Many mining dump trucks operate 24 hours a day, and the harsh working environment in mines, including noise, dust, and bumps, poses a great threat to the health of drivers, especially at night and in rainy or snowy weather when visibility and the environment are even worse, increasing the risk of accidents.

[0005] Therefore, existing technologies have led to the development of unmanned driving control for mining dump trucks. Currently, braking systems that enable both manned and unmanned driving typically integrate a proportional pressure reducing valve into the brake valve block. When manned, braking is achieved using the original vehicle's brake pedal valve. When switching to unmanned driving, the output pressure of the proportional pressure reducing valve is adjusted by sending an electrical signal to achieve braking function. However, if a fault occurs in the brake hydraulic system when the mining dump truck is unmanned, manned braking cannot be achieved, posing a safety hazard.

[0006] Therefore, there is an urgent need for a braking system for engineering vehicles to solve the above-mentioned technical problems. Summary of the Invention

[0007] The purpose of this invention is to provide a braking system for engineering vehicles and a mining dump truck that can achieve both manned and unmanned braking, thereby improving safety.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] Braking systems for engineering vehicles include:

[0010] The brake valve block has a first brake oil port A1 and a second brake oil port A2;

[0011] An electric proportional brake valve includes a first electric proportional brake valve and a second electric proportional brake valve, wherein the first brake oil port A1 is connected to the oil inlet of the first electric proportional brake valve, and the second brake oil port A2 is connected to the oil inlet of the second electric proportional brake valve.

[0012] The manual / automatic switching valve includes a first manual / automatic switching valve and a second manual / automatic switching valve. The oil outlet of the first electro-proportional brake valve is connected to the first oil inlet of the first manual / automatic switching valve, and the oil outlet of the second electro-proportional brake valve is connected to the second oil inlet of the second manual / automatic switching valve.

[0013] The brake includes a first brake and a second brake, wherein the oil outlet of the first manual-automatic switching valve is connected to the rodless chamber of the first brake, and the oil outlet of the second manual-automatic switching valve is connected to the rodless chamber of the second brake.

[0014] A dual-circuit pedal valve assembly includes a first pedal valve and a second pedal valve. The first pedal valve and the second pedal valve can operate synchronously and send a manned braking signal to power a proportional brake valve. The first brake fluid port A1 is connected to the inlet of the first pedal valve, the outlet of the first pedal valve is connected to the third inlet of the first manual-automatic switching valve, the second brake fluid port A2 is connected to the inlet of the second pedal valve, and the outlet of the first pedal valve is connected to the fourth inlet of the second manual-automatic switching valve.

[0015] The hydraulic oil supply structure is connected to the oil supply port of the brake valve block to supply oil to the brake.

[0016] As a preferred technical solution for the braking system of the aforementioned engineering vehicle, the brake valve block also has a brake oil loading port A3, and a brake solenoid valve is also provided inside the brake valve block. The oil inlet of the brake solenoid valve is connected to the oil supply port of the brake valve block, and the oil outlet of the brake solenoid valve is connected to the brake oil loading port A3. The brake oil loading port A3 is connected to the pilot end of the second pedal valve, and the second brake is configured to brake the rear wheels.

[0017] As a preferred technical solution for the braking system of the aforementioned engineering vehicle, the brake valve block also has an automatic emergency brake port A4. The brake valve block is also provided with a pressure selection valve group. The inlet of the pressure selection valve group is connected to the first brake port A1 and the second brake port A2, and the outlet of the pressure selection valve group is connected to the automatic emergency brake port A4. The automatic emergency brake port A4 is connected to the pilot end of the first pedal valve and the pilot end of the second pedal valve, respectively. The pressure selection valve group is configured to obtain the oil pressure of the first brake port A1 and the second brake port A2 and close or open the automatic emergency brake port A4 according to the oil pressure of the first brake port A1 and the second brake port A2.

[0018] As a preferred technical solution for the braking system of the above-mentioned engineering vehicle, the brake valve block also has an electric emergency brake port A5, and an electric emergency brake valve is also provided inside the brake valve block. The oil inlet of the electric emergency brake valve is connected to the oil supply port of the brake valve block, and the oil outlet of the electric emergency brake valve is connected to the electric emergency brake port A5. The electric emergency brake port A5 is connected to the pilot end of the first pedal valve and the pilot end of the second pedal valve, respectively.

[0019] As a preferred technical solution for the aforementioned braking system for engineering vehicles, the braking system for engineering vehicles further includes a first shuttle valve and a second shuttle valve. The two inlets of the first shuttle valve are respectively connected to the automatic emergency brake port A4 and the electric emergency brake port A5. The outlet of the first shuttle valve is respectively connected to one of the inlets of the second shuttle valve and the pilot end of the first pedal valve. The other inlet of the second shuttle valve is connected to the loading brake port A3. The outlet of the second shuttle valve is connected to the pilot end of the second pedal valve.

[0020] As a preferred technical solution for the braking system of the aforementioned engineering vehicle, the hydraulic oil supply structure includes a hydraulic oil tank, a hydraulic pump, a first accumulator, and a second accumulator. The oil inlet of the hydraulic pump is connected to the hydraulic oil tank, and the oil outlet of the hydraulic pump is connected to the oil supply port of the brake valve block. The oil supply port of the brake valve block includes a first oil supply port P1, a second oil supply port ACC1, and a third oil supply port ACC2. The first accumulator is connected to the second oil supply port ACC1, and the second accumulator is connected to the third oil supply port ACC2. The hydraulic pump is connected to the first oil supply port P1. The first oil supply port P1 is connected to both the second oil supply port ACC1 and the third oil supply port ACC2. The second oil supply port ACC1 is also connected to the oil inlet of the pressure selection valve group, the first brake oil port A1, and the oil inlet of the mounted brake solenoid valve. The third oil supply port ACC2 is connected to the second brake oil port A2, the electric emergency brake valve, and the oil inlet of the pressure selection valve group.

[0021] As a preferred technical solution for the braking system of the aforementioned engineering vehicle, the pressure selection valve group includes a hydraulic control valve and an automatic emergency braking valve. The two inlets of the hydraulic control valve are respectively connected to the first accumulator and the second accumulator, and the two hydraulic control terminals of the hydraulic control valve are respectively connected to the first accumulator and the second accumulator. The outlet of the hydraulic control valve is connected to the pilot terminal of the automatic emergency braking valve. The inlet of the automatic emergency braking valve is selectively connected to the second oil supply port ACC1 or the third oil supply port ACC2 through a third shuttle valve. The outlet of the automatic emergency braking valve is connected to the automatic emergency braking port A4.

[0022] As a preferred technical solution for the braking system of the above-mentioned engineering vehicle, a first check valve is provided between the first oil supply port P1 and the second oil supply port ACC1, and a second check valve is provided between the first oil supply port P1 and the third oil supply port ACC2. The first check valve only allows oil to flow from the first oil supply port P1 to the second oil supply port ACC1, and the second check valve only allows oil to flow from the first oil supply port P1 to the third oil supply port ACC2.

[0023] As a preferred technical solution for the braking system of the above-mentioned engineering vehicle, the hydraulic oil supply structure further includes a third accumulator, the valve block has a fourth oil supply port ACC3, the third accumulator is connected to the hydraulic pump, the first accumulator and the second accumulator through the fourth oil supply port ACC3, and the third accumulator can compensate the oil for the first accumulator and the second accumulator.

[0024] As a preferred technical solution for the braking system of the above-mentioned engineering vehicle, the brake also includes a parking brake. A parking brake solenoid valve is provided in the brake valve block. The oil inlet of the parking brake solenoid valve is connected to the oil supply port of the brake valve block, and the oil outlet of the parking brake solenoid valve is connected to the parking oil port of the brake valve block. The parking brake solenoid valve is used to control the connection or disconnection between the oil supply port of the brake valve block and the parking brake.

[0025] As a preferred technical solution for the above-mentioned braking system for engineering vehicles, the braking system for engineering vehicles further includes an emergency braking power unit. The pilot end of the automatic emergency braking valve is also connected to the emergency braking power unit, and the emergency braking power unit is also connected to the first oil supply port P1. An emergency braking check valve is directly provided between the emergency braking power unit and the pilot end of the automatic emergency braking valve. The emergency braking check valve only allows oil to flow from the emergency braking power unit to the automatic emergency braking valve.

[0026] The present invention also provides a mining dump truck, including a control system as described in any of the above embodiments.

[0027] Beneficial effects of this invention:

[0028] In this invention, the two inlets of the first manual / automatic switching valve are connected to the first electro-proportional brake valve and the first pedal valve, respectively, and the two inlets of the second manual / automatic switching valve are connected to the second electro-proportional brake valve and the second pedal valve, respectively. Thus, the first manual / automatic switching valve can selectively connect the first brake fluid port A1 to either the first electro-proportional brake valve or the first pedal valve according to the vehicle's driving state, and the second manual / automatic switching valve can selectively connect the second brake fluid port A2 to either the second electro-proportional brake valve or the second pedal valve according to the vehicle's driving state. This achieves the braking purpose during both manual and automatic driving, thereby improving driving safety and reliability. Since the dual-circuit pedal valve assembly and the electro-proportional brake valve act simultaneously on the braking system of the engineering vehicle, when the driver discovers an emergency requiring braking during autonomous driving, the lower positions of the first and second pedal valves are activated, and hydraulic fluid flows directly from the dual-circuit pedal valve assembly into the manual-automatic switching valve. After the dual-circuit pedal valve assembly is activated, the valve core of the manual-automatic switching valve changes to connect with the brake. The dual-circuit pedal valve assembly sends a manned braking signal to the electro-proportional brake valve, which then de-energizes and stops working. In this way, the controller can receive the signal from the dual-circuit pedal valve assembly and control the electro-proportional brake valve to stop working, thus improving the priority of manned operation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0030] Figure 1 Hydraulic schematic diagram of a braking system for engineering vehicles provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the internal hydraulic principle of the brake valve block provided in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram showing the connection relationship between the electric proportional brake valve, the manual / automatic switching valve, and the dual-circuit pedal valve group provided in an embodiment of the present invention.

[0033] In the picture:

[0034] 1. Brake valve block; 11. Loading brake solenoid valve; 12. Hydraulic control valve; 13. Automatic emergency brake valve; 14. Electric emergency brake valve; 15. Third check valve; 17. Third shuttle valve; 18. First check valve; 19. Second check valve; 110. Parking brake solenoid valve; 111. Pressure reducing valve; 112. Emergency brake check valve; 113. First manual throttle valve; 114. Second manual throttle valve; 21. First electric proportional brake valve; 22. Second electric proportional brake valve; 3 1. First manual / automatic switching valve; 32. Second manual / automatic switching valve; 41. First brake; 42. Second brake; 43. Parking brake; 51. First pedal valve; 52. Second pedal valve; 61. Hydraulic oil tank; 62. Hydraulic pump; 63. First accumulator; 64. Second accumulator; 65. Third accumulator; 66. Suction filter; 67. High-pressure filter; 68. First filter check valve; 69. Second filter check valve; 7. First shuttle valve; 8. Second shuttle valve. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0036] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0039] This invention provides a braking system for engineering vehicles and a mining dump truck, the latter including the engineering vehicle braking system. This engineering vehicle braking system enables both manual and automatic braking, improving the driving safety of the mining dump truck.

[0040] like Figures 1 to 3 As shown, the braking system for this engineering vehicle includes a brake valve block 1, an electric proportional brake valve, a manual / automatic switching valve, a brake, a dual-circuit pedal valve assembly, and a hydraulic oil supply structure. The brake valve block 1 has a first brake oil port A1 and a second brake oil port A2, which allow hydraulic fluid to flow out of the brake valve block 1. The electric proportional brake valve includes a first electric proportional brake valve 21 and a second electric proportional brake valve 22. The first brake oil port A1 is connected to the inlet of the first electric proportional brake valve 21, and the second brake oil port A2 is connected to the inlet of the second electric proportional brake valve 22. The manual / automatic switching valve includes a first manual / automatic switching valve 31 and a second manual / automatic switching valve 32. The oil outlet of the first electro-proportional brake valve 21 is connected to the first oil inlet of the first manual / automatic switching valve 31, and the oil outlet of the second electro-proportional brake valve 22 is connected to the second oil inlet of the second manual / automatic switching valve 32. The brake includes a first brake 41 and a second brake 42. The oil outlet of the first manual / automatic switching valve 31 is connected to the rodless chamber of the first brake 41, and the oil outlet of the second manual / automatic switching valve 32 is connected to the rodless chamber of the second brake 42.

[0041] The dual-circuit pedal valve assembly includes a first pedal valve 51 and a second pedal valve 52. The first pedal valve 51 and the second pedal valve 52 can operate synchronously and send a manned braking signal to power the proportional brake valve. The first brake oil port A1 is connected to the oil inlet of the first pedal valve 51, the oil outlet of the first pedal valve 51 is connected to the third oil inlet of the first manual-automatic switching valve 31, the second brake oil port A2 is connected to the oil inlet of the second pedal valve 52, and the oil outlet of the first pedal valve 51 is connected to the fourth oil inlet of the second manual-automatic switching valve 32. The hydraulic oil supply structure is connected to the oil supply port of the brake valve block 1 to supply oil to the brake.

[0042] In this embodiment, since the two inlets of the first manual / automatic switching valve 31 are connected to the first electro-proportional brake valve 21 and the first pedal valve 51 respectively, and the two inlets of the second manual / automatic switching valve 32 are connected to the second electro-proportional brake valve 22 and the second pedal valve 52 respectively, the first manual / automatic switching valve 31 can selectively connect the first brake fluid port A1 to the first electro-proportional brake valve 21 or the first pedal valve 51 according to the vehicle's driving state, and the second manual / automatic switching valve 32 can selectively connect the second brake fluid port A2 to the second electro-proportional brake valve 22 or the second pedal valve 52 according to the vehicle's driving state. This achieves the braking purpose during manual or automatic driving, thereby improving driving safety and reliability. Since the dual-circuit pedal valve assembly and the electric proportional brake valve act simultaneously on the braking system of the engineering vehicle, when the driver discovers an emergency requiring braking during automatic driving, the lower positions of the first pedal valve 51 and the second pedal valve 52 are activated, and the hydraulic fluid flows directly from the dual-circuit pedal valve assembly into the manual-automatic switching valve. After the dual-circuit pedal valve assembly is activated, the valve core of the manual-automatic switching valve changes to connect with the brake. The dual-circuit pedal valve assembly sends a manned braking signal to the electric proportional brake valve, which then de-energizes and stops working. In this way, the controller can receive the signal from the dual-circuit pedal valve assembly and control the electric proportional brake valve to stop working, thus improving the priority of manned operation.

[0043] Specifically, the dual-circuit pedal valve assembly also includes a limit switch. When the driver depresses the pedal, the limit switch is activated, causing the controller to de-energize the manual / automatic switching valve and the electric proportional brake valve, forcibly switching back to the manned braking state and ensuring priority for manned operation. The specific structure of the dual-circuit pedal valve assembly is existing technology and will not be described in detail here.

[0044] To enable parking brakes to be applied when the vehicle is parked in a safe position to prevent it from rolling, in some embodiments, such as Figure 1 and Figure 2 As shown, the brake also includes a parking brake 43. A parking brake solenoid valve 110 and a pressure reducing valve 111 are provided in the brake valve block 1. The brake valve block 1 has a parking oil port and a return oil port. The oil inlet of the parking brake solenoid valve 110 is connected to the oil outlet of the pressure reducing valve 111. The oil return port of the parking brake solenoid valve 110 is connected to the return oil port in the brake valve block 1. The oil inlet of the pressure reducing valve 111 is connected to the oil supply port of the brake valve block 1. The parking brake solenoid valve 110 is used to control the connection or disconnection of the oil supply port of the brake valve block 1 with the parking brake 43.

[0045] refer to Figure 1 and Figure 2When parking brake is required, the driver presses the parking brake button, or the controller sends a parking brake electrical signal in an unmanned driving state. The parking brake solenoid valve 110 is de-energized, and the valve core of the parking brake solenoid valve 110 returns to its natural state under the action of the spring force. The oil in the parking brake 43 enters the parking brake solenoid valve 110 through the parking oil port on the brake valve block 1. The oil outlet of the parking brake solenoid valve 110 is connected to the oil tank through the oil return port T1 of the brake valve block 1. At this time, the oil in the parking brake 43 is released through the pipeline to the parking oil port and then through the brake valve block 1, and the parking brake 43 applies the brake under the action of the spring force. When the parking brake solenoid valve 110 is energized, the oil is depressurized through the pressure reducing valve 111 and then flows into the parking brake 43 through the parking brake solenoid valve 110 to release the brake.

[0046] Because large-tonnage dump trucks carry heavy loads, they are often loaded using large-tonnage loaders or electric shovels. The loading and unloading of materials generates significant impact on the truck bed, and a standalone parking brake would damage the parking brake 43. Therefore, in some embodiments, such as... Figure 2 As shown, the brake valve block 1 has a brake fluid loading port A3. A brake solenoid valve 11 is also installed within the brake valve block 1. The inlet of the brake solenoid valve 11 is connected to the supply port of the brake valve block 1, and the outlet of the brake solenoid valve 11 is connected to the brake fluid loading port A3. The brake fluid loading port A3 is connected to the pilot end of the second pedal valve 52, while the second brake 42 is used to brake the rear wheels. This reduces the impact on the entire frame, body, and critical components when materials fall.

[0047] When the driver presses the loading brake button, or when the controller sends an electrical signal command in unmanned driving mode, the loading brake solenoid valve 11 in the brake valve block 1 is energized. The loading brake oil port A3 provides oil to the pilot end of the second pedal valve 52, causing the brake valve core of the second pedal valve 52 to move and the valve port to open. The oil enters the second brake 42 through the second manual-automatic switching valve 32. The second brake 42 is used to limit the rotation of the rear wheels, thereby achieving rear wheel braking.

[0048] In some embodiments, such as Figure 1As shown, the hydraulic oil supply structure includes a hydraulic oil tank 61, a hydraulic pump 62, a first accumulator 63, a second accumulator 64, and a third accumulator 65. The oil inlet of the hydraulic pump 62 is connected to the hydraulic oil tank 61, and the oil outlet of the hydraulic pump 62 is connected to the oil supply port of the brake valve block 1. The oil supply port of the brake valve block 1 includes a first oil supply port P1, a second oil supply port ACC1, a third oil supply port ACC2, and a fourth oil supply port ACC3. The first accumulator 63 is connected to the second oil supply port ACC1, the second accumulator 64 is connected to the third oil supply port ACC2, and the third accumulator 65 is connected to the fourth oil supply port ACC3. The first accumulator 63 and the second accumulator 64 provide oil to the first brake 41 and the second brake 42, respectively. When the oil in the first accumulator 63 and the second accumulator 64 is insufficient, the third accumulator 65 provides oil to the first accumulator 63 and the second accumulator 64. The hydraulic pump 62 is connected to the first oil supply port P1. The first oil supply port P1 is connected to the second oil supply port ACC1, the third oil supply port ACC2, and the fourth oil supply port ACC3. In this way, the hydraulic pump 62 supplies oil to the first accumulator 63, the second accumulator 64, and the third accumulator 65 through the first oil supply port P1. The second oil supply port ACC1 is also connected to the first brake oil port A1 and the oil inlet of the mounted brake solenoid valve 11. The third oil supply port ACC2 is connected to the second brake oil port A2 and the electric emergency brake valve 14.

[0049] To facilitate subsequent maintenance, the first accumulator 63 and the second accumulator 64 are connected to the oil return port T2 of the brake valve block 1. A first manual throttle valve 113 is provided between the first accumulator 63 and the oil return port T2, and a second manual throttle valve 114 is provided between the second accumulator 64 and the oil return port T2. When the first accumulator 63 and the second accumulator 64 need maintenance, the first manual throttle valve 113 and the second manual throttle valve 114 are opened, allowing the oil in the first accumulator 63 and the second accumulator 64 to flow back to the oil tank through the oil return port T2.

[0050] The hydraulic oil supply structure also includes an oil suction filter 66 installed at the oil inlet of the hydraulic pump 62 and a high-pressure filter 67 installed at the outlet of the hydraulic pump 62. A first filter check valve 68 is also installed in parallel at the oil suction filter 66, and a second filter check valve 69 is also installed in parallel at the high-pressure filter 67. The first filter check valve 68 only allows oil to flow from the hydraulic oil tank 61 to the hydraulic pump 62, and the second filter check valve 69 only allows oil to flow from the hydraulic pump 62 to the brake valve block 1.

[0051] When the oil pressure in the first accumulator 63 and the second accumulator 64 is low, it may lead to subsequent braking failure. To ensure the safety of the mining dump truck, in some embodiments, combined with... Figures 1 to 3As shown, the brake valve block 1 has an automatic emergency brake port A4. A pressure selection valve assembly is also provided within the brake valve block 1. The inlet of the pressure selection valve assembly is connected to the first brake port A1 and the second brake port A2, and the outlet of the pressure selection valve assembly is connected to the automatic emergency brake port A4. The automatic emergency brake port A4 is connected to the pilot end of the first pedal valve 51 and the pilot end of the second pedal valve 52, respectively. The two inlets of the pressure selection valve assembly are connected to the first brake port A1 and the second brake port A2, respectively. The pressure selection valve assembly is configured to acquire the oil pressure of the first brake port A1 and the second brake port A2 and close or open the automatic emergency brake port A4 according to the oil pressure of the first brake port A1 and the second brake port A2.

[0052] The pressure selector valve assembly determines whether to open based on the oil pressure at the inlet, allowing oil to flow through the automatic emergency brake port A4 and act on the dual-circuit pedal valve assembly. This achieves safe braking and prevents brake failure due to insufficient brake fluid during driving, ensuring driving safety. It should be noted that the pressure selector valve remains operational regardless of whether the vehicle is in automatic or manual driving mode, thus guaranteeing the safety of both driver and vehicle.

[0053] Specifically, combined Figures 1 to 3 As shown, the pressure selection valve group includes a hydraulic control valve 12 and an automatic emergency brake valve 13. The two oil inlets of the hydraulic control valve 12 are connected to the first accumulator 63 and the second accumulator 64, respectively. That is, the two oil inlets of the hydraulic control valve 12 are connected to the first brake oil port A1 and the second brake oil port A2, respectively. The two hydraulic control terminals of the hydraulic control valve 12 are connected to the first accumulator 63 and the second accumulator 64, respectively. For ease of description, the two inlets of the hydraulic control valve 12 are defined as the first hydraulic control inlet and the second hydraulic control inlet, and the two hydraulic control terminals of the hydraulic control valve 12 are defined as the first hydraulic control terminal and the second hydraulic control terminal. The first hydraulic control inlet and the first hydraulic control terminal are both connected to the first brake oil port A1, and the second hydraulic control inlet and the second hydraulic control terminal are both connected to the second brake oil port A2. The outlet of the hydraulic control valve 12 is connected to the pilot terminal of the automatic emergency brake valve 13. When the oil pressure of the second brake oil port A2 is higher than the oil pressure of the first brake oil port A1, the valve core of the hydraulic control valve 12 will be pushed upward. At this time, the lower position of the hydraulic control valve 12 is open, and the low-pressure oil of the first brake oil port A1 is output to the pilot terminal of the automatic emergency brake valve 13. When the oil pressure at the first brake port A1 is higher than that at the second brake port A2, the valve core of the hydraulic control valve 12 will be pushed downward. At this time, the upper position of the hydraulic control valve 12 is turned on, and the low-pressure oil from the second brake port A2 is output to the pilot end of the automatic emergency brake valve 13. The hydraulic control valve 12 always selects low-pressure oil output.

[0054] In some embodiments, combined with Figures 1 to 3As shown, the braking system for this engineering vehicle also includes a first shuttle valve 7 and a second shuttle valve 8. The two inlets of the first shuttle valve 7 are connected to the automatic emergency brake port A4 and the electric emergency brake port A5, respectively. The outlet of the first shuttle valve 7 is connected to one inlet of the second shuttle valve 8 and the pilot end of the first pedal valve 51. The other inlet of the second shuttle valve 8 is connected to the loading brake port A3, and the outlet of the second shuttle valve 8 is connected to the pilot end of the second pedal valve 52. By selecting the valve with the higher oil pressure, braking can be ensured.

[0055] The inlet of the automatic emergency brake valve 13 is selectively connected to either the second oil supply port ACC1 or the third oil supply port ACC2 via the third shuttle valve 17. This allows the inlet of the automatic emergency brake valve 13 to receive high-pressure oil from either the second or third oil supply port ACC1. The pilot end of the automatic emergency brake valve 13 receives oil from the outlet of the hydraulic control valve 12. If the pressure is insufficient to overcome the spring force set in the automatic emergency brake valve 13, the valve core moves upward, and the lower position of the automatic emergency brake valve 13 is opened. Oil then flows through the outlet of the automatic emergency brake valve 13 to its outlet and into the dual-circuit pedal valve assembly for braking. This ensures that the remaining oil is sufficient for automatic emergency braking.

[0056] Automatic emergency brake valve 13 is a reversing valve.

[0057] Combination Figures 1 to 3 As shown, when the system pressure drops to the set value, the pressure selection valve group automatically selects the low-pressure signal from the first brake port A1 and the second brake port A2 and sends it to the automatic emergency brake valve 13. When the pressure of the first brake port A1 and the second brake port A2 drops to the set value, the automatic emergency brake valve 13 resets under the action of the spring force, connects the high-pressure oil circuit in the first brake port A1 and the second brake port A2 that has been filtered by the third shuttle valve 17, and outputs high-pressure oil through the automatic emergency brake port A4. The high-pressure oil ultimately acts on the pilot end PP1 port of the first pedal valve 51 and the pilot end PP2 port of the second pedal valve 52, which is equivalent to a person quickly and urgently pressing the pedal to apply emergency braking and maintain it.

[0058] To prevent insufficient hydraulic fluid from achieving automatic emergency braking, in some embodiments, the braking system for engineering vehicles also includes an emergency braking power unit. The pilot end of the automatic emergency braking valve 13 is connected to the emergency braking power unit. An emergency braking check valve 112 is directly connected between the emergency braking power unit and the pilot end of the automatic emergency braking valve 13. The emergency braking check valve 112 only allows hydraulic fluid to flow from the emergency braking power unit to the automatic emergency braking valve 13. This enables automatic emergency braking in the event of a malfunction of the hydraulic pump 62.

[0059] In some embodiments, in order to enable emergency braking of the vehicle in case of a sudden situation, the brake valve block 1 also has an electric emergency brake port A5, and an electric emergency brake valve 14 is also provided in the brake valve block 1. The oil inlet of the electric emergency brake valve 14 is connected to the third oil supply port ACC2 (or the second brake port A2), and the oil outlet of the electric emergency brake valve 14 is connected to the electric emergency brake port A5. The electric emergency brake port A5 is connected to the pilot end of the first pedal valve 51 and the pilot end of the second pedal valve 52 respectively.

[0060] For example, when a driver encounters a sudden situation and needs to apply emergency braking to the vehicle, after the driver presses the emergency brake button, the valve core of the electric emergency brake valve 14 moves to the left and is in the right position. At this time, the second accumulator 64 supplies oil to the electric emergency brake valve 14. The oil enters the dual-circuit pedal valve group through the electric emergency brake port A5. At this time, the pilot ends of the first pedal valve 51 and the second pedal valve 52 are in the open position, the valve core moves down, and the upper position of the first pedal valve 51 and the second pedal valve 52 is in the open position. The oil enters the first pedal valve 51 and the second pedal valve 52 through the oil inlet (first oil supply port P1) of the brake valve block 1. Then, the oil enters the brake through the first manual-automatic switching valve 31 and the second manual-automatic switching valve 32 respectively.

[0061] For example, when the vehicle is unmanned and encounters an emergency, the controller sends an emergency braking signal. The valve core of the electric emergency brake valve 14 moves to the left and is in the right position. At this time, the second accumulator 64 supplies oil to the electric emergency brake valve 14. The oil enters the dual-circuit pedal valve group through the electric emergency brake port A5. At this time, the pilot ends of the first pedal valve 51 and the second pedal valve 52 are in the open position, the valve core moves down, and the upper position of the first pedal valve 51 and the second pedal valve 52 is in the open position. The oil enters the first pedal valve 51 and the second pedal valve 52 through the brake valve block inlet (first oil supply port P1). Then, the oil enters the brake through the first manual-automatic switching valve 31 and the second manual-automatic switching valve 32 respectively.

[0062] To prevent the oil in the first accumulator 63 and the second accumulator 64 from flowing back into the hydraulic pump 62, in some embodiments, a first check valve 18 is provided between the first oil supply port P1 and the second oil supply port ACC1, and a second check valve 19 is provided between the first oil supply port P1 and the third oil supply port ACC2. The first check valve 18 only allows oil to flow from the first oil supply port P1 to the second oil supply port ACC1, and the second check valve 19 only allows oil to flow from the first oil supply port P1 to the third oil supply port ACC2. A third check valve 15 is provided between the first oil supply port P1 and the fourth oil supply port ACC3. The third check valve 15 only allows oil to flow from the first oil supply port P1 to the fourth oil supply port ACC3. It should be noted that the fourth oil supply port ACC3 is also connected to the second oil supply port ACC1 through the first check valve 18, and the fourth oil supply port ACC3 is also connected to the third oil supply port ACC2 through the second check valve 19. This can prevent the oil in the first accumulator 63 and the second accumulator 64 from entering the third accumulator 65.

[0063] Furthermore, the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A braking system for engineering vehicles, characterized in that, include: The brake valve block (1) has a first brake oil port A1 and a second brake oil port A2; The electric proportional brake valve includes a first electric proportional brake valve (21) and a second electric proportional brake valve (22), wherein the first brake oil port A1 is connected to the oil inlet of the first electric proportional brake valve (21), and the second brake oil port A2 is connected to the oil inlet of the second electric proportional brake valve (22). The manual-automatic switching valve includes a first manual-automatic switching valve (31) and a second manual-automatic switching valve (32). The oil outlet of the first electric proportional brake valve (21) is connected to the first oil inlet of the first manual-automatic switching valve (31), and the oil outlet of the second electric proportional brake valve (22) is connected to the second oil inlet of the second manual-automatic switching valve (32). The brake includes a first brake (41) and a second brake (42), the oil outlet of the first manual-automatic switching valve (31) is connected to the rodless chamber of the first brake (41), and the oil outlet of the second manual-automatic switching valve (32) is connected to the rodless chamber of the second brake (42). The dual-circuit pedal valve assembly includes a first pedal valve (51) and a second pedal valve (52). The first pedal valve (51) and the second pedal valve (52) can operate synchronously and send a manned braking signal to power the proportional brake valve. The first brake oil port A1 is connected to the oil inlet of the first pedal valve (51). The oil outlet of the first pedal valve (51) is connected to the third oil inlet of the first manual-automatic switching valve (31). The second brake oil port A2 is connected to the oil inlet of the second pedal valve (52). The oil outlet of the first pedal valve (51) is connected to the fourth oil inlet of the second manual-automatic switching valve (32). The hydraulic oil supply structure is connected to the oil supply port of the brake valve block (1) to supply oil to the brake. The brake valve block (1) also has a brake oil loading port A3. A brake solenoid valve (11) is installed inside the brake valve block (1). The oil inlet of the brake solenoid valve (11) is connected to the oil supply port of the brake valve block (1). The oil outlet of the brake solenoid valve (11) is connected to the brake oil loading port A3. The brake oil loading port A3 is connected to the pilot end of the second pedal valve (52). The second brake (42) is configured to brake the rear wheel. The brake valve block (1) also has an automatic emergency brake port A4. The brake valve block (1) is also provided with a pressure selection valve group. The inlet of the pressure selection valve group is connected to the first brake port A1 and the second brake port A2. The outlet of the pressure selection valve group is connected to the automatic emergency brake port A4. The automatic emergency brake port A4 is connected to the pilot end of the first pedal valve (51) and the pilot end of the second pedal valve (52). The pressure selection valve group is configured to obtain the oil pressure of the first brake port A1 and the second brake port A2 and close or open the automatic emergency brake port A4 according to the oil pressure of the first brake port A1 and the second brake port A2.

2. The braking system for engineering vehicles according to claim 1, characterized in that, The brake valve block (1) also has an electric emergency brake port A5. An electric emergency brake valve (14) is also provided inside the brake valve block (1). The oil inlet of the electric emergency brake valve (14) is connected to the oil supply port of the brake valve block (1). The oil outlet of the electric emergency brake valve (14) is connected to the electric emergency brake port A5. The electric emergency brake port A5 is connected to the pilot end of the first pedal valve (51) and the pilot end of the second pedal valve (52) respectively.

3. The braking system for engineering vehicles according to claim 2, characterized in that, The braking system for the engineering vehicle also includes a first shuttle valve (7) and a second shuttle valve (8). The two inlets of the first shuttle valve (7) are respectively connected to the automatic emergency brake port A4 and the electric emergency brake port A5. The outlet of the first shuttle valve (7) is respectively connected to one of the inlets of the second shuttle valve (8) and the pilot end of the first pedal valve (51). The other inlet of the second shuttle valve (8) is connected to the loading brake port A3. The outlet of the second shuttle valve (8) is connected to the pilot end of the second pedal valve (52).

4. The braking system for engineering vehicles according to claim 3, characterized in that, The hydraulic oil supply structure includes a hydraulic oil tank (61), a hydraulic pump (62), a first accumulator (63), and a second accumulator (64). The inlet of the hydraulic pump (62) is connected to the hydraulic oil tank (61), and the outlet of the hydraulic pump (62) is connected to the supply port of the brake valve block (1). The supply ports of the brake valve block (1) include a first supply port P1, a second supply port ACC1, and a third supply port ACC2. The first accumulator (63) is connected to the second supply port ACC1, and the second accumulator (64) is connected to... The third oil supply port ACC2 is connected, the hydraulic pump (62) is connected to the first oil supply port P1, the first oil supply port P1 is connected to the second oil supply port ACC1 and the third oil supply port ACC2 respectively, the second oil supply port ACC1 is also connected to the oil inlet of the pressure selection valve group, the first brake oil port A1, and the oil inlet of the loading brake solenoid valve (11) respectively, and the third oil supply port ACC2 is connected to the second brake oil port A2, the electric emergency brake valve (14), and the oil inlet of the pressure selection valve group respectively.

5. The braking system for engineering vehicles according to claim 4, characterized in that, The pressure selection valve group includes a hydraulic control valve (12) and an automatic emergency brake valve (13). The two inlets of the hydraulic control valve (12) are connected to the first accumulator (63) and the second accumulator (64) respectively, and the two hydraulic control terminals of the hydraulic control valve (12) are connected to the first accumulator (63) and the second accumulator (64) respectively. The outlet of the hydraulic control valve (12) is connected to the pilot terminal of the automatic emergency brake valve (13). The inlet of the automatic emergency brake valve (13) is selectively connected to the second oil supply port ACC1 or the third oil supply port ACC2 through the third shuttle valve (17). The outlet of the automatic emergency brake valve (13) is connected to the automatic emergency brake oil port A4.

6. The braking system for engineering vehicles according to claim 5, characterized in that, A first check valve (18) is provided between the first oil supply port P1 and the second oil supply port ACC1, and a second check valve (19) is provided between the first oil supply port P1 and the third oil supply port ACC2. The first check valve (18) only allows oil to flow from the first oil supply port P1 to the second oil supply port ACC1, and the second check valve (19) only allows oil to flow from the first oil supply port P1 to the third oil supply port ACC2.

7. The braking system for engineering vehicles according to claim 1, characterized in that, The brake also includes a parking brake (43). A parking brake solenoid valve (110) is provided inside the brake valve block (1). The oil inlet of the parking brake solenoid valve (110) is connected to the oil supply port of the brake valve block (1), and the oil outlet of the parking brake solenoid valve (110) is connected to the parking oil port of the brake valve block (1). The parking brake solenoid valve (110) is used to control the connection or disconnection between the oil supply port of the brake valve block (1) and the parking brake (43).

8. A mining dump truck, characterized in that, Includes the braking system for engineering vehicles as described in any one of claims 1-7.

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