Hydraulic locking control system for maintenance mode of mining dump truck

Abstract

The invention discloses a maintenance mode hydraulic locking control system for a mining dump truck, which belongs to the technical field of mining machinery and comprises an oil tank, a steering hydraulic pump is connected in the oil tank through a steering pump pipeline, a maintenance locking hydraulic pump is connected in the oil tank through a maintenance locking pipeline, and a lifting hydraulic pump is connected in the oil tank through a lifting pump pipeline; one end, far away from the oil tank, of the maintenance locking hydraulic pump is divided into two paths which are respectively connected with a steering maintenance locking valve group and a lifting maintenance locking valve group; the end, away from the oil tank, of the steering hydraulic pump is connected with a steering gear and a steering oil cylinder through a steering maintenance locking valve set. The end, away from the oil tank, of the lifting hydraulic pump is connected with a lifting valve, a lifting handle and a lifting oil cylinder through a lifting maintenance locking valve set. The maintenance locking hydraulic pump controls connection and disconnection of the steering oil way and the lifting oil way through the steering maintenance locking valve set and the lifting maintenance locking valve set respectively. The method has the advantage that the safety is improved.

Description

Technical Field

[0001] This invention relates to the field of mining machinery technology, specifically to a hydraulic locking control system for the maintenance mode of a mining dump truck. Background Technology

[0002] Mining dump trucks are technically complex and operate under special conditions. Sometimes, vehicle debugging or maintenance work needs to be carried out while the engine is running. Currently, the hydraulic system of vehicles on the market will automatically build up pressure when the engine is running. If someone accidentally operates the vehicle steering or lifting while the engine is running, it may cause damage to components or even safety accidents. The hydraulic pump can be stopped by removing it or disconnecting the hydraulic pump drive shaft, but this is time-consuming and labor-intensive. Summary of the Invention

[0003] The present invention addresses the technical problems mentioned in the background section above by providing a hydraulic locking control system for the maintenance mode of a mining dump truck. By installing a maintenance hydraulic locking valve in the existing hydraulic system, the hydraulic system of the vehicle can be stopped when the engine is running, thus entering the maintenance hydraulic locking mode. This system is convenient to operate and highly safe.

[0004] According to the present invention, the technical solution provided by the present invention is: a hydraulic locking control system for maintenance mode of a mining dump truck, including an oil tank, a steering hydraulic pump connected to the oil tank through a steering pump pipeline, a maintenance locking hydraulic pump connected to the oil tank through a maintenance locking pipeline, and a lifting hydraulic pump connected to the oil tank through a lifting pump pipeline. The maintenance locking hydraulic pump is divided into two lines at the end furthest from the oil tank, which are respectively connected to the steering maintenance locking valve group and the lifting maintenance locking valve group; The end of the steering hydraulic pump furthest from the oil tank is connected to the steering gear and the steering cylinder via a steering maintenance locking valve assembly; The end of the lifting hydraulic pump furthest from the oil tank is connected to the lifting valve, lifting handle, and lifting cylinder via a lifting maintenance locking valve assembly. The maintenance locking hydraulic pump controls the on / off of the steering oil circuit and the lifting oil circuit through the steering maintenance locking valve group and the lifting maintenance locking valve group, respectively.

[0005] In some embodiments, the steering maintenance lock valve assembly includes a maintenance lock solenoid valve and a maintenance lock hydraulic control valve, and the steering maintenance lock valve assembly is further provided with X, A, P, T, T1 and T2 ports. The maintenance locking solenoid valve is a multi-position four-way solenoid valve, including a first working position and a second working position. In the first working position, ports I and III are connected, as are ports II and IV. In the second working position, ports I and IV are connected, as are ports II and III. The maintenance-locking hydraulic control valve is a multi-position four-way hydraulic control valve, including a third working position and a fourth working position. In the third working position, ports V and VII are connected, while ports VI and VIII are not connected. In the fourth working position, ports V and VIII are not connected, while ports VI and VII are connected. The maintenance-locking hydraulic control valve also has a first pilot port and a second pilot port on both sides. The two ends of port X are connected to the maintenance locking pipeline and port III of the maintenance locking solenoid valve, respectively. Port A is connected to the steering gear hydraulic circuit and port V of the maintenance lock hydraulic control valve, respectively. The two ends of port P are connected to the steering pump pipeline and port VII of the maintenance lock hydraulic control valve, respectively. The two ends of port T are connected to the oil tank and port VIII of the maintenance lock hydraulic control valve, respectively. The two ends of port T1 are connected to the oil tank and port IV of the maintenance locking solenoid valve, respectively. The two ends of port T2 are connected to the oil tank and port VI of the maintenance lock hydraulic control valve, respectively. The I port of the maintenance locking solenoid valve is connected to the first pilot port of the maintenance locking hydraulic control valve. The maintenance lock solenoid valve's port II is connected to the maintenance lock hydraulic control valve's second pilot port.

[0006] In some embodiments, the lifting service locking valve assembly and the steering service locking valve assembly have the same internal structure and connection method. The P port of the lifting maintenance locking valve assembly is externally connected to the lifting pump pipeline. The external port A of the lifting maintenance locking valve assembly is connected to the lifting valve. The T, T1, and T2 ports of the lifting and maintenance locking valve assembly are externally connected to the oil tank.

[0007] In some embodiments, a check valve is provided on the steering pump line between the steering hydraulic pump and the steering maintenance lock valve assembly to control the hydraulic oil to flow only from the steering hydraulic pump to the steering maintenance lock valve assembly.

[0008] In some embodiments, one side of the steering pump line is also connected to the parking brake via a parking brake solenoid valve.

[0009] In some embodiments, the parking brake solenoid valve includes a braking position and a release position. When the parking brake solenoid valve is in the brake position, the hydraulic oil in the parking brake is connected to the oil tank. When the parking brake solenoid valve is in the released position, the hydraulic oil in the parking brake is connected to the steering pump line, and the hydraulic oil in the steering pump line enters the parking brake under the drive of the steering hydraulic pump.

[0010] In some embodiments, the parking brake solenoid valve is a multi-position three-way solenoid valve, including a braking position and a release position. Port I and Port II of the braking position are connected, while Port III of the braking position is not connected. Port I and Port III are connected in the release position, while Port II is not connected in the braking position. Port I of the parking brake solenoid valve is connected to the parking brake, port II of the parking brake solenoid valve is connected to the oil tank, and port III of the parking brake solenoid valve is connected to the power steering pump pipeline.

[0011] In some embodiments, a check valve is provided between the steering pump line and the parking brake solenoid valve to control the hydraulic oil to flow only from the hydraulic pump line to the parking brake solenoid valve.

[0012] In some embodiments, a maintenance locking motor is driven to one side of the maintenance locking hydraulic pump, and the maintenance locking hydraulic pump is driven by the maintenance locking motor, which draws power directly from the vehicle battery.

[0013] In some embodiments, the solenoid valves of the steering service lock valve assembly and the lift service lock valve assembly draw power directly from the vehicle battery.

[0014] In some embodiments, a maintenance lock switch is installed on the vehicle, and the steering maintenance lock valve assembly, parking brake solenoid valve, and lifting maintenance lock valve assembly are all controlled by a single button of the vehicle maintenance lock switch.

[0015] The advantages of this invention compared to existing technologies are as follows: 1. By designing a hydraulic locking solenoid valve in the hydraulic system, the pressure oil circuits for hydraulic steering and lifting are depressurized, thereby achieving hydraulic system locking and avoiding safety risks caused by misoperation during vehicle maintenance while the engine is running; 2. The maintenance locking control valve group is controlled by an independent low-power maintenance locking motor and maintenance locking hydraulic pump, requiring little power, easy to install, and applicable to various mining dump trucks, with strong adaptability; 3. The maintenance locking motor is conveniently powered by the vehicle battery, and the vehicle battery continues to charge while the engine is running for maintenance, preventing battery depletion.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the hydraulic locking control system for the maintenance mode of a mining dump truck according to an embodiment of the present invention; Figure 2 for Figure 1 The diagram shows a steering maintenance locking valve assembly. Figure 3 for Figure 1 The diagram shown is a schematic of the parking brake solenoid valve. In the attached diagram: 1. Steering hydraulic pump; 2. Steering maintenance locking valve assembly; 3. Parking brake solenoid valve; 4. Parking brake; 5. Steering gear; 6. Steering cylinder; 7. Lifting cylinder; 8. Lifting handle; 9. Lifting valve; 10. Lifting maintenance locking valve assembly; 11. Lifting hydraulic pump; 12. Maintenance locking hydraulic pump; 13. Maintenance locking motor; 14. Oil tank; 2.1 Maintenance and locking solenoid valve; 2.1.1 First working position; 2.1.2 Second working position; 2.2 Maintenance and locking of the hydraulic control valve; 2.2.1 Third working position; 2.2.2 Fourth working position; 2.2.3 First pilot port; 2.2.4 Second pilot port; 3.1 Braking position; 3.2 Release position. Detailed Implementation

[0018] The present invention will now be described in further detail.

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0020] Combination Figure 1 As shown, a hydraulic locking control system for the maintenance mode of a mining dump truck includes a steering hydraulic pump 1 connected to the oil tank 14 via a steering pump pipeline, a maintenance locking hydraulic pump 12 connected to the oil tank 14 via a maintenance locking pipeline, and a lifting hydraulic pump 11 connected to the oil tank 14 via a lifting pump pipeline. The upper part of the maintenance locking hydraulic pump 12, which is away from the oil tank 14, is divided into two paths: one path is connected to the steering maintenance locking valve group 2, and the other path is connected to the lifting maintenance locking valve group 10. The upper end of the steering hydraulic pump 1, which is away from the oil tank 14, is divided into two paths. One path is connected to the steering gear 5 and the steering cylinder 6 through the steering maintenance locking valve group 2, and the other path is connected to the parking brake 4 through the parking brake solenoid valve 3.

[0021] The upper end of the lifting hydraulic pump 11, away from the oil tank 14, is connected to the lifting valve 9, the lifting handle 8, and the lifting cylinder 7 via the lifting maintenance locking valve assembly 10.

[0022] The vehicle is equipped with a maintenance lock switch. The steering maintenance lock valve group 2, parking brake solenoid valve 3, and lifting maintenance lock valve group 10 are all controlled by the vehicle maintenance lock switch with one button.

[0023] A maintenance locking motor 13 is connected to one side of the maintenance locking hydraulic pump 12. The maintenance locking hydraulic pump 12 is driven by the maintenance locking motor 13, which draws power directly from the vehicle battery. The steering maintenance locking valve group 2, the lifting maintenance locking valve group 10, and the parking brake solenoid valve 3 also draw power directly from the vehicle battery.

[0024] Combination Figure 2 As shown, the steering maintenance lock valve assembly 2 includes a maintenance lock solenoid valve 2.1 and a maintenance lock hydraulic control valve 2.2. The steering maintenance lock valve assembly 2 is also equipped with interfaces such as X, A, P, T, T1 and T2.

[0025] The maintenance locking solenoid valve 2.1 is a two-position four-way solenoid valve. In the first working position 2.1.1, ports I and III are connected, and ports II and IV are connected. In the second working position 2.1.2, ports I and IV are connected, and ports II and III are connected.

[0026] The maintenance-locking hydraulic control valve 2.2 is a two-position four-way hydraulic control valve. In the third working position 2.2.1, ports V and VII are connected, while ports VI and VIII are not connected. In the fourth working position 2.2.2, ports V and VIII are not connected, while ports VI and VII are connected. The maintenance-locking hydraulic control valve 2.2 also has a first pilot port 2.2.3 and a second pilot port 2.2.4 on both sides. The two ends of port X are connected to the maintenance locking pipeline and port III of maintenance locking solenoid valve 2.1, respectively; The two ends of port A are connected to the oil circuit of steering gear 5 and port V of maintenance lock hydraulic control valve 2.2, respectively; The two ends of port P are connected to the steering pump pipeline and port VII of the maintenance lock hydraulic control valve 2.2, respectively; The two ends of port T are connected to the oil tank 14 and port VIII of the maintenance locking hydraulic control valve 2.2, respectively; The two ends of port T1 are connected to port IV of oil tank 14 and maintenance locking solenoid valve 2.1, respectively; The two ends of port T2 are connected to the oil tank 14 and port VI of the maintenance locking hydraulic control valve 2.2, respectively; The first port of the maintenance locking solenoid valve 2.1 is connected to the first pilot port 2.2.3 of the maintenance locking hydraulic control valve 2.2; The second port of the maintenance locking solenoid valve 2.1 is connected to the second pilot port 2.2.4 of the maintenance locking hydraulic control valve 2.2.

[0027] The lifting maintenance locking valve assembly 10 and the steering maintenance locking valve assembly 2 have the same internal structure and connection method; the difference lies in the connection method of their external interfaces, as follows: The P port of the lifting maintenance locking valve assembly 10 is externally connected to the lifting pump pipeline. The external port A of the lifting maintenance locking valve assembly 10 is connected to the lifting valve 9. The T, T1, and T2 ports of the lifting maintenance locking valve assembly 10 are externally connected to the oil tank 14.

[0028] Combination Figure 3 As shown, the parking brake solenoid valve 3 is a two-position three-way solenoid valve, including a braking position 3.1 and a release position 3.2. Port I and port II of the braking position 3.1 are connected, while port III of the braking position 3.1 is not connected; Port I and port III of the release position 3.2 are connected, while port II of the braking position 3.1 is not connected. Port I of the parking brake solenoid valve 3 is connected to the parking brake 4, port II of the parking brake solenoid valve 3 is connected to the oil tank 14, and port III of the parking brake solenoid valve 3 is connected to the power steering pump line. When the parking brake solenoid valve 3 is in the braking position 3.1, the hydraulic oil of the parking brake 4 is connected to the oil tank 14; when the parking brake solenoid valve 3 is in the release position 3.2, the hydraulic oil of the parking brake 4 is connected to the steering pump pipeline, and the hydraulic oil in the steering pump pipeline enters the parking brake 4 under the drive of the steering hydraulic pump 1. This embodiment is used in specific applications.

[0029] Hydraulic steering system maintenance locking principle: If the vehicle is in normal operating mode at this time, the maintenance lock switch is closed, and both the maintenance lock motor 13 and the maintenance lock hydraulic pump 12 are not working. Therefore, the maintenance lock hydraulic pump 12 does not output pressurized oil, the steering maintenance lock valve assembly 2 is not working, and the maintenance lock solenoid valve 2.1 is not energized. Under the action of the spring on the left side of the maintenance lock solenoid valve 2.1, the maintenance lock solenoid valve 2.1 is in the left position (first working position 2.1.1). Since the maintenance lock hydraulic pump 12 is not working, the first pilot port 2.2.3 on the left side of the maintenance lock hydraulic control valve 2.2 is at zero pressure. Simultaneously, the second pilot port 2.2.4 on the right side of the maintenance lock hydraulic control valve 2.2 connects to ports II and IV of the first working position 2.1.1 of the maintenance lock solenoid valve 2.1. The steering maintenance lock valve is directly connected to the hydraulic oil tank 14 via port T1. Therefore, at this time, the first pilot port 2.2.3 on the left and the second pilot port 2.2.4 on the right of the maintenance lock hydraulic control valve 2.2 are both in a zero-pressure state. Under the action of the spring force on the left side of the maintenance lock hydraulic control valve 2.2, the maintenance lock hydraulic control valve 2.2 is also in the left position (third working position 2.2.1). The pressure oil output by the steering hydraulic pump 1 enters through port P of the steering maintenance lock valve, flows through ports VII and V of the third working position 2.2.1 of the maintenance lock hydraulic control valve 2.2, and is output from port A of the steering maintenance lock valve. Then it flows to the steering gear 5. If the driver operates the steering gear 5 at this time, the pressure oil will enter the steering cylinder 6, thereby realizing the steering action.

[0030] If the vehicle is in engine start-up maintenance mode at this time, the maintenance lock switch is activated, and the maintenance lock motor 13 drives the maintenance lock hydraulic pump 12 to work, outputting pressurized oil. Simultaneously, the steering maintenance lock valve operates, energizing the maintenance lock solenoid valve 2.1. Under the action of the solenoid coil, the maintenance lock solenoid valve 2.1 is in the right position (second working position 2.1.2). Therefore, the pressurized oil output by the maintenance lock hydraulic pump 12 flows through ports III and II of the right position (second working position 2.1.2) of the maintenance lock solenoid valve 2.1 to the second pilot port 2.2.4 on the right side of the maintenance lock hydraulic control valve 2.2. At this time, the hydraulic oil from the first pilot port 2.2.3 on the left side of the maintenance lock hydraulic control valve 2.2 flows through ports I and IV of the second working position 2.1.2 of the maintenance lock solenoid valve 2.1 to T... Port T1 of the steering maintenance lock valve is directly connected to the hydraulic oil tank 14. Therefore, at this time, the left pilot port of the maintenance lock hydraulic control valve 2.2 is in a zero-pressure state. The pressure oil at the second pilot port 2.2.4 on the right side of the maintenance lock hydraulic control valve 2.2 overcomes the spring force on the left side of the maintenance lock hydraulic control valve 2.2, and the maintenance lock hydraulic control valve 2.2 is also in the right position (second working position 2.1.2). Then, the pressure oil output by the steering hydraulic pump 1 enters through the P port of the steering maintenance lock valve, flows through the VII and VI ports of the fourth working position 2.2.2 on the right side of the maintenance lock hydraulic control valve 2.2, and is discharged from the T2 port of the steering maintenance lock valve to the oil tank 14. At this time, the steering hydraulic pump 1 is in a zero-pressure mode, and the oil circuit to the steering gear 5 and the steering cylinder 6 is cut off. That is, the steering hydraulic system is in a locked mode at this time, and the steering cylinder 6 will not be activated due to the misoperation of the maintenance personnel. Hydraulic lifting system maintenance locking principle: The maintenance and locking principle of the hydraulic lifting system is the same as that of the hydraulic steering system, except that the steering hydraulic pump 1 of the hydraulic steering system is replaced by the lifting hydraulic pump 11.

[0031] The other similar principles will not be elaborated further. Hydraulic parking brake system maintenance locking principle: When the engine is running.

[0032] If the vehicle is in normal operation and the maintenance lock switch is not open, the parking brake solenoid valve 3 is energized. Under the action of the electromagnetic coil, the parking brake solenoid valve 3 is in the right position (release position 3.2). The pressure oil output by the steering hydraulic pump 1 flows to the parking brake 4 through the III and I ports of the right position of the parking brake solenoid valve 3. At this time, the parking brake 4 is in the released state.

[0033] If the vehicle is in maintenance mode, the maintenance lock switch is turned on, the parking brake solenoid valve 3 is not energized, and the parking brake solenoid valve 3 is in the left position (brake position 3.1) under the action of the left spring. The hydraulic oil in the parking brake 4 is connected to the hydraulic oil tank 14 through the I and II ports of the left position of the parking brake solenoid valve 3. At this time, the parking brake 4 is in the state of applying braking.

[0034] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A hydraulic locking control system for the maintenance mode of a mining dump truck, comprising an oil tank (14), characterized in that: The oil tank (14) is connected to a steering hydraulic pump (1) via a steering pump pipeline, the oil tank (14) is connected to a maintenance locking hydraulic pump (12) via a maintenance locking pipeline, and the oil tank (14) is connected to a lifting hydraulic pump (11) via a lifting pump pipeline. The maintenance locking hydraulic pump (12) is divided into two paths at the end away from the oil tank (14), which are respectively connected to the steering maintenance locking valve group (2) and the lifting maintenance locking valve group (10); The end of the steering hydraulic pump (1) away from the oil tank (14) is connected to the steering gear (5) and the steering cylinder (6) through the steering maintenance locking valve assembly (2); The end of the lifting hydraulic pump (11) away from the oil tank (14) is connected to the lifting valve (9), lifting handle (8) and lifting cylinder (7) through the lifting maintenance locking valve assembly (10); The maintenance locking hydraulic pump (12) controls the opening and closing of the steering oil circuit and the lifting oil circuit through the steering maintenance locking valve group (2) and the lifting maintenance locking valve group (10), respectively.

2. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 1, characterized in that: The steering maintenance locking valve assembly (2) includes a maintenance locking solenoid valve (2.1) and a maintenance locking hydraulic control valve (2.2). The steering maintenance locking valve assembly (2) is also provided with ports X, A, P, T, T1 and T2. The maintenance locking solenoid valve (2.1) is a multi-position four-way solenoid valve, including a first working position (2.1.1) and a second working position (2.1.2). Ports I and III of the first working position (2.1.1) are connected, as are ports II and IV. Similarly, ports I and IV of the second working position (2.1.2) are connected, as are ports II and III. The maintenance locking hydraulic control valve (2.2) is a multi-position four-way hydraulic control valve, including a third working position (2.2.1) and a fourth working position (2.2.2). Ports V and VII of the third working position (2.2.1) are connected, while ports VI and VIII are not connected. Ports V and VIII of the fourth working position (2.2.2) are not connected, while ports VI and VII are connected. The maintenance locking hydraulic control valve (2.2) also has a first pilot port (2.2.3) and a second pilot port (2.2.4) on both sides. The two ends of port X are connected to the maintenance locking pipeline and port III of the maintenance locking solenoid valve (2.1), respectively. The two ends of port A are connected to the oil circuit of the steering gear (5) and port V of the maintenance lock hydraulic control valve (2.2), respectively. The two ends of port P are connected to the steering pump pipeline and port VII of the maintenance lock hydraulic control valve (2.2), respectively. The two ends of port T are connected to the oil tank (14) and port VIII of the maintenance locking hydraulic control valve (2.2), respectively. The two ends of port T1 are connected to the oil tank (14) and port IV of the maintenance locking solenoid valve (2.1), respectively. The two ends of port T2 are connected to the oil tank (14) and port VI of the maintenance locking hydraulic control valve (2.2), respectively. The I port of the maintenance locking solenoid valve (2.1) is connected to the first pilot port (2.2.3) of the maintenance locking hydraulic control valve (2.2). The II port of the maintenance locking solenoid valve (2.1) is connected to the second pilot port (2.2.4) of the maintenance locking hydraulic control valve (2.2).

3. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 2, characterized in that: The lifting maintenance locking valve assembly (10) and the steering maintenance locking valve assembly (2) have the same internal structure and connection method. The P port of the lifting maintenance locking valve assembly (10) is connected to the lifting pump pipeline. The A port of the lifting maintenance locking valve assembly (10) is connected to the lifting valve (9). The T, T1 and T2 ports of the lifting maintenance locking valve assembly (10) are externally connected to the oil tank (14).

4. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 1, characterized in that: A check valve is provided on the steering pump pipeline between the steering hydraulic pump (1) and the steering maintenance locking valve group (2) to control the hydraulic oil to flow only from the steering hydraulic pump (1) to the steering maintenance locking valve group (2).

5. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 1, characterized in that: One side of the steering pump pipeline is also connected to the parking brake (4) via the parking brake solenoid valve (3).

6. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 5, characterized in that: The parking brake solenoid valve (3) includes a braking position (3.1) and a release position (3.2). When the parking brake solenoid valve (3) is in the braking position (3.1), the hydraulic oil of the parking brake (4) is connected to the oil tank (14). When the parking brake solenoid valve (3) is in the release position (3.2), the hydraulic oil of the parking brake (4) is connected to the steering pump pipeline, and the hydraulic oil in the steering pump pipeline enters the parking brake (4) under the drive of the steering hydraulic pump (1).

7. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 6, characterized in that: The parking brake solenoid valve (3) is a multi-position three-way solenoid valve, including a braking position (3.1) and a release position (3.2). Port I and Port II of the braking position (3.1) are connected, while Port III of the braking position (3.1) is not connected. Port I and Port III of the release position (3.2) are connected, while Port II of the braking position (3.1) is not connected. The parking brake solenoid valve (3) has port I connected to the parking brake (4), port II connected to the oil tank (14), and port III connected to the steering pump pipeline.

8. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 5, characterized in that: A check valve is provided between the steering pump pipeline and the parking brake solenoid valve (3) to control the hydraulic oil to flow only from the hydraulic pump pipeline to the parking brake solenoid valve (3).

9. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 2, characterized in that: A maintenance locking motor (13) is connected to one side of the maintenance locking hydraulic pump (12). The maintenance locking hydraulic pump (12) is driven by the maintenance locking motor (13), which draws power directly from the vehicle battery.

10. The hydraulic locking control system for the maintenance mode of the mining dump truck according to claim 3, characterized in that: The solenoid valves of the steering maintenance lock valve assembly (2) and the lift maintenance lock valve assembly (10) are powered directly from the vehicle battery.

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