Unmanned mining dump truck and dual-redundancy hydraulic four-wheel steering system and method

Abstract

The invention discloses a dual-redundancy hydraulic four-wheel steering system which comprises a steering valve group, a plunger pump, a hydraulic oil tank, a front axle steering cylinder, a first electro-hydraulic steering valve, a second electro-hydraulic steering valve, a rear axle steering cylinder, a third electro-hydraulic steering valve, a fourth electro-hydraulic steering valve, a first flow amplifier, a second flow amplifier, a first converging valve group and a second converging valve group. The invention further discloses an unmanned mining dump truck and a dual-redundancy hydraulic four-wheel steering method. The two flow amplifiers are controlled through the four electro-hydraulic steering valves to achieve the steering action of the front steering cylinder and the rear steering cylinder, the steering requirement of bidirectional driving is met, meanwhile, the front axle and rear axle dual-redundancy steering function is achieved, and steering safety is improved.

Description

Technical Field

[0001] The present invention belongs to the field of unmanned electric wheel mining dump trucks, and in particular relates to an unmanned mining dump truck, a dual redundant hydraulic four-wheel steering system and a method. Background Art

[0002] Electric wheel mining dump truck is an off-road dump truck, mainly used for large open-pit mines and the transportation of mineral materials. Electric wheel mining dump truck is mainly composed of frame, power system, travel system, electrical system and hydraulic system, among which the hydraulic steering system is an important component of electric wheel mining dump truck, which plays a vital role in the controllability and safety of the vehicle.

[0003] With the development of unmanned driving technology and the intelligent construction of mining areas in recent years, the technology of unmanned mining dump trucks has become increasingly mature. Some mining truck manufacturers at home and abroad have successively released unmanned mining truck products, which can achieve four-wheel steering and two-way driving, greatly improving transportation efficiency. The hydraulic steering system of traditional one-way mining trucks can no longer meet the requirements of new mining trucks, and the safety of unmanned driving also needs to be greatly improved. Summary of the invention

[0004] The purpose of the present invention is to provide an unmanned mining dump truck, a dual-redundant hydraulic four-wheel steering system and method, which realizes the steering action of the front and rear steering cylinders by controlling two flow amplifiers through four electro-hydraulic steering valves, meets the steering requirements of two-way driving, and realizes the dual-redundant steering function of the front and rear axles to improve steering safety.

[0005] To achieve the above purpose, the technical solution used in the present invention is:

[0006] Dual redundant hydraulic four-wheel steering system, including: steering valve group, plunger pump, hydraulic oil tank, front axle steering cylinder, first electro-hydraulic steering valve, second electro-hydraulic steering valve, first flow amplifier, first confluence valve group;

[0007] The plunger pump is used to pressurize the hydraulic oil, and its oil inlet is connected to the hydraulic oil tank through a pipeline, and its oil outlet is connected to the oil inlet P1 of the steering valve group through a pipeline;

[0008] The steering valve group is used to provide pressure oil to the first flow amplifier, the oil return port T is connected to the oil tank through a pipeline, and the oil outlet STR1 of the steering valve group is connected to the oil inlet HP of the first flow amplifier through a pipeline;

[0009] The first electro-hydraulic steering valve and the second electro-hydraulic steering valve receive the control signal and output the pilot pressure oil to the first flow amplifier. The oil inlet, oil return port and oil outlet of the first electro-hydraulic steering valve and the second electro-hydraulic steering valve are respectively connected to the oil inlet, oil return port and oil outlet of the first flow amplifier through the first converging valve group;

[0010] The first flow amplifier is used to control the steering mechanism action of the front axle, and its oil outlet is connected to the front axle steering cylinder through a pipeline. The front axle steering cylinder is used to control the steering of the front wheels.

[0011] Furthermore, it also includes: a second flow amplifier, a rear axle steering cylinder, a third electro-hydraulic steering valve, a fourth electro-hydraulic steering valve, and a second converging valve group; the steering valve group is used to provide pressure oil to the first flow amplifier and the second flow amplifier, and the oil outlet STR2 is connected to the oil inlet HP of the second flow amplifier through a pipeline; the third electro-hydraulic steering gear and the fourth electro-hydraulic steering valve respectively receive control signals and output pilot pressure oil to the second flow amplifier, and their oil inlet, oil return port and oil outlet are correspondingly connected to the oil inlet, oil return port and oil outlet of the second flow amplifier through the second converging valve group; the second flow amplifier is used to control the steering mechanism action of the rear axle, and its oil outlet is connected to the rear axle steering cylinder through a pipeline, and the rear axle steering cylinder is used to control the steering of the rear wheels.

[0012] Furthermore, the front axle steering cylinder includes: a front axle left steering cylinder and a front axle right steering cylinder. The oil outlet CL and the oil outlet CR of the first flow amplifier are respectively connected to the front axle left steering cylinder and the front axle right steering cylinder through pipelines; the oil outlet CL and the oil outlet CR of the second flow amplifier are respectively connected to the rear axle left steering cylinder and the rear axle right steering cylinder through pipelines, and the return oil ports of the first flow amplifier, the second flow amplifier and the steering valve group are connected to the hydraulic oil tank through pipelines.

[0013] Furthermore, the plunger pump is a constant pressure variable displacement pump.

[0014] Further, the hydraulic oil is converted into high-pressure oil by the plunger pump and enters the P1 port of the steering valve group through the pipeline. The STR1 port and STR2 port of the steering valve group are respectively connected to the HP port of the first flow amplifier and the HP port of the second flow amplifier through the pipeline; the L port, R port, P port, T port and LS port of the first electro-hydraulic steering valve and the second electro-hydraulic steering valve are respectively connected to the L port, R port, P port, T port and LS port of the first flow amplifier through the first confluence valve group; the L port, R port, P port, T port and LS port of the third electro-hydraulic steering gear and the fourth electro-hydraulic steering valve are respectively connected to the L port, R port, P port, T port and LS port of the second flow amplifier through the second confluence valve group; the CL port and CR port of the first flow amplifier are respectively connected to the front axle left steering cylinder and the front axle right steering cylinder through the pipeline to control the steering of the front wheels; the CL port and CR port of the second flow amplifier are connected to the rear axle left steering cylinder and the rear axle right steering cylinder to control the steering of the rear wheels, and return to the hydraulic oil tank through the HT port of the first flow amplifier, the second flow amplifier and the T of the steering valve group.

[0015] Furthermore, the steering valve group is an integrated valve, including: a solenoid reversing valve, a throttle valve, a safety valve, and a one-way valve, wherein accumulators are installed at the A1, A2, and A3 ports, wherein the safety valve is installed between the P1 port, the P2 port, and the T port; the solenoid reversing valve is located between the P1 port and the T port; the throttle valve is located between the solenoid reversing valve and the P port; and the one-way valve is located after the P1 port and before the A1 port and the A2 port.

[0016] Furthermore, a pressure sensor is provided at the TSB port of the steering valve group, and the pressure sensor is connected to the pressure switch via a wire.

[0017] Unmanned mining dump truck, including dual redundant hydraulic four-wheel steering system.

[0018] The dual redundant hydraulic four-wheel steering method of the unmanned mining dump truck includes:

[0019] The plunger pump outputs pressure oil to the steering valve group, and the steering valve group provides pressure oil to the first flow amplifier and the second flow amplifier respectively;

[0020] The first electro-hydraulic steering valve and the second electro-hydraulic steering valve receive a control signal and output pilot pressure oil to the first flow amplifier; the third electro-hydraulic steering valve and the fourth electro-hydraulic steering valve receive a control signal and output pilot pressure oil to the second flow amplifier. The first flow amplifier controls the steering mechanism of the front axle, and the second flow amplifier controls the steering mechanism of the rear axle.

[0021] Preferably, when the vehicle is traveling forward, the first electro-hydraulic steering valve and the second electro-hydraulic steering valve control the first flow amplifier to perform steering action on the front steering cylinder, so that the front wheels of the vehicle serve as active steering wheels; when the vehicle is traveling backward, the third electro-hydraulic steering valve and the fourth electro-hydraulic steering valve control the second flow amplifier to perform steering action on the rear steering cylinder, so that the rear wheels of the vehicle serve as active steering wheels.

[0022] Preferably, the first electro-hydraulic steering valve and the second electro-hydraulic steering valve output pilot pressure oil to the first flow amplifier under the control of the electrical signal, and the oil outlet CL and the oil outlet CR of the first flow amplifier are connected to the front axle steering cylinder to control the steering mechanism of the front axle, and the excess pressure oil returns to the hydraulic oil tank through the HT port of the first flow amplifier and the return oil filter; the third electro-hydraulic steering valve and the fourth electro-hydraulic steering valve output pilot pressure oil to control the second flow amplifier under the control of the electrical signal, and the oil outlet CL and the oil outlet CR of the second flow amplifier 16 are connected to the rear axle steering cylinder to control the steering mechanism of the rear axle, and the excess pressure oil returns to the hydraulic oil tank through the return oil filter at the HT port of the second flow amplifier.

[0023] The technical effects of the present invention include:

[0024] 1. The present invention adopts the principle that every two electro-hydraulic steering valves control one flow amplifier to realize the dual-redundant steering function of a single flow amplifier.

[0025] Two electro-hydraulic steering valves are used to provide pilot control oil for the flow amplifier. The two flow amplifiers control the front and rear axle steering cylinders respectively. The front and rear axles use electro-hydraulic steering valves for redundant steering control respectively. Even if one of the electro-hydraulic steering valves fails, the steering function of the mine car will not be affected.

[0026] 2. The present invention is easy to implement and improves the safety of the hydraulic steering function of the unmanned mining vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural principle diagram of a dual redundant hydraulic four-wheel steering system of an unmanned mining dump truck in the present invention.

[0028] Among them: 1. Steering valve group; 1.1. Stop valve; 1.2. Throttle valve; 1.3. Safety valve; 1.4. Check valve; 2. Plunger pump; 3. Hydraulic oil tank; 4. Filter; 5. Accumulator; 6. Pressure switch; 7. Front axle left steering cylinder; 8. Front axle right steering cylinder; 9. First electro-hydraulic steering valve; 10. Second electro-hydraulic steering valve; 11. Rear axle left steering cylinder; 12. Rear axle right steering cylinder; 13. Third electro-hydraulic steering valve; 14. Fourth electro-hydraulic steering valve; 15. First flow amplifier; 16. Second flow amplifier; 17. First confluence valve group; 18. Second confluence valve group. DETAILED DESCRIPTION

[0029] In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

[0030] The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0031] In the embodiments of the present disclosure, the terms "upper", "lower", "inside", "middle", "outside", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly intended to better describe the embodiments of the present disclosure and their embodiments, and are not intended to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction. Moreover, in addition to being used to indicate directions or positional relationships, some of the above terms may also be used to indicate other meanings. For example, the term "upper" may also be used to indicate a certain dependency or connection relationship in certain circumstances. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0032] In addition, the terms "disposed", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0033] Unless otherwise stated, the term "plurality" means two or more.

[0034] In the embodiment of the present disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B indicates: A or B.

[0035] The term "and / or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or, A and B.

[0036] It should be noted that, in the case of no conflict, the embodiments and features in the embodiments of the present disclosure can be combined with each other. The following description fully illustrates the specific embodiments of the present invention so that those skilled in the art can practice and reproduce.

[0037] like Figure 1 Shown is a structural schematic diagram of the dual redundant hydraulic four-wheel steering system of the present invention.

[0038] The dual redundant hydraulic four-wheel steering system is applied to unmanned mining dump trucks; the hydraulic oil tank 3 is a storage device for hydraulic oil; the plunger pump 2 provides pressure and flow for the system; among the four electro-hydraulic steering valves, every two electro-hydraulic steering valves provide pilot control oil for a flow amplifier respectively; the steering cylinder acts as an actuator to drive the vehicle steering mechanism to complete the steering.

[0039] The dual redundant hydraulic four-wheel steering system comprises: a steering valve group 1, a plunger pump 2, a hydraulic oil tank 3, a front axle left steering cylinder 7, a front axle right steering cylinder 8, a first electro-hydraulic steering valve (EHI) 9, a second electro-hydraulic steering valve (EHI) 10, a rear axle left steering cylinder 11, a rear axle right steering cylinder 12, a third electro-hydraulic steering valve (EHI) 13, a fourth electro-hydraulic steering valve 14, a first flow amplifier 15, a second flow amplifier 16, a first merging valve group 17, and a second merging valve group 18.

[0040] The hydraulic oil is converted into high-pressure oil by the plunger pump 2 and enters the P1 port (oil inlet) of the steering valve group 1 through the pipeline. The STR1 port (oil outlet) and the STR2 port (oil outlet) of the steering valve group 1 are respectively connected to the HP port (oil inlet) of the first flow amplifier 15 and the HP port (oil inlet) of the second flow amplifier 16 through pipelines; the L port, R port, P port, T port, and LS port of the first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 are respectively connected to the L port, R port, P port, T port, and LS port of the first flow amplifier 15 through the first converging valve group 17; the L port, R port of the third electro-hydraulic steering gear 13 and the L port, R port of the fourth electro-hydraulic steering valve 14 are respectively connected to the L port, R port, P port, T port, and LS port of the first flow amplifier 15. The , P, T and LS ports are respectively connected to the L, R, P, T and LS ports of the second flow amplifier 16 through the second converging valve group 18; the CL and CR ports of the first flow amplifier 15 are respectively connected to the front axle steering cylinders (front axle left steering cylinder 7 and front axle right steering cylinder 8) through pipelines to control the front wheel steering; the CL port (oil outlet) and CR port (oil outlet) of the second flow amplifier 16 are connected to the rear axle steering cylinders (rear axle left steering cylinder 11 and rear axle right steering cylinder 12) to control the rear wheel steering, and return to the hydraulic oil tank 3 through the first flow amplifier 15, the HT port of the second flow amplifier 16 and the T of the steering valve group 1.

[0041] The plunger pump 2 is used to pressurize the hydraulic oil. The oil inlet of the plunger pump 2 is connected to the hydraulic oil tank 3 through a pipeline, and the oil outlet of the plunger pump 2 is connected to the P1 port (oil inlet) of the steering valve group 1 through a pipeline; the plunger pump 2 is a constant pressure variable pump.

[0042] The steering valve group 1 is used to provide pressure oil to the first flow amplifier 15 and the second flow amplifier 16. The T port (oil return port) is connected to the oil tank 3 through a pipeline. The STR1 port (oil outlet) of the steering valve group 1 is connected to the HP port of the first flow amplifier 15 through a pipeline. The STR2 port (oil outlet) of the steering valve group 1 is connected to the HP port (oil inlet) of the second flow amplifier 16 through a pipeline.

[0043] The first electro-hydraulic steering valve 9 receives the control signal and outputs the first flow amplifier 15 of the pilot pressure oil, and the P port (oil inlet) and the T port (oil return port) are respectively connected to the P port and the T port of the first flow amplifier 15 through pipelines; the L port (oil inlet) of the first electro-hydraulic steering valve 9 is connected to the L1 port (oil inlet) of the first converging valve group 17 through a pipeline, the R port (oil return port) is connected to the R1 port (oil return port) of the first converging valve group 17 through a pipeline, and the LS1 port (oil outlet) is connected to the LS2 port (oil outlet) of the first converging valve group 17 through a pipeline;

[0044] The second electro-hydraulic steering valve 10 receives the control signal and outputs the pilot pressure oil to the second flow amplifier 16. The P port (oil inlet) and the T port (oil return port) are respectively connected to the P port and the T port of the first flow amplifier 15 through the pipeline; the L port (oil inlet) of the second electro-hydraulic steering valve 10 is connected to the L2 port (oil inlet) of the first converging valve group 17, and the R port (oil return port) of the second electro-hydraulic steering valve 10 is connected to the R2 port (oil return port) of the first converging valve group 17; the LS1 port (oil outlet) of the second electro-hydraulic steering valve 10 is connected to the LS3 port (oil outlet) of the first converging valve group 17 through the pipeline;

[0045] The first flow amplifier 15 is used to control the steering mechanism action of the front axle. The L port (oil inlet) is connected to the L3 port (oil inlet) of the first merging valve group 17 through a pipeline, the R port is connected to the R3 port (oil return port) of the first merging valve group 17 through a pipeline, and the LS port (oil outlet) is connected to the LS1 port (oil outlet) of the first merging valve group 17 through a pipeline; the CL of the first flow amplifier 15 is connected to the C1 port of the front axle left steering cylinder 7 and the C2 port of the front axle right steering cylinder 8; the CR of the first flow amplifier 15 is connected to the C2 port of the front axle left steering cylinder 7 and the C2 port of the front axle right steering cylinder 8; the HT port (oil return port) of the first flow amplifier 15 is connected to the oil tank 3 through pipelines respectively;

[0046] The P port (oil inlet) and the T port (oil return port) of the third electro-hydraulic steering valve 13 are connected to the P port and the T port of the second flow amplifier 16 through pipelines, respectively; the L port (oil inlet) of the third electro-hydraulic steering valve 13 is connected to the L1 port (oil inlet) of the second converging valve group 18 through a pipeline; the R port (oil return port) of the third electro-hydraulic steering valve 13 is connected to the R1 port (oil return port) of the second converging valve group 18 through a pipeline; the LS1 port (oil outlet) of the third electro-hydraulic steering valve 13 is connected to the LS2 port (oil outlet) of the second converging valve group 18;

[0047] The P port (oil inlet) and T port (oil return port) of the fourth electro-hydraulic steering valve 14 are connected to the P port and T port of the second flow amplifier 16 through pipelines, respectively; the L port is connected to the L2 port (oil inlet) of the second converging valve group 18 through a pipeline; the R port (oil return port) is connected to the R2 port (oil return port) of the second converging valve group 18 through a pipeline; the LS1 (oil outlet) of the fourth electro-hydraulic steering valve 14 is connected to the LS3 (oil outlet) of the second converging valve group 18;

[0048] The second flow amplifier 16 controls the steering mechanism of the rear axle, the L port (oil inlet) is connected to the L3 port (oil inlet) of the second merging valve group 18 through a pipeline, the R port (oil return port) is connected to the R3 port (oil return port) of the second merging valve group 18 through a pipeline, and the LS port (oil outlet) is connected to the LS1 (oil outlet) of the second merging valve group 18;

[0049] The CL of the second flow amplifier 16 is connected to the C1 port of the rear axle left steering cylinder 11 and the C2 port of the rear axle right steering cylinder 12; the CR of the second flow amplifier 16 is connected to the C2 port of the rear axle left steering cylinder 11 and the C1 port of the rear axle right steering cylinder 12; the HT port (return oil port) of the second flow amplifier 16 is connected to the oil tank 3 through pipelines.

[0050] The dual redundant hydraulic four-wheel steering method for unmanned mining dump trucks has the following specific steps:

[0051] Step 1: The plunger pump 2 outputs pressure oil to the steering valve group 1;

[0052] Step 2: The steering valve group 1 provides pressure oil to the first flow amplifier 15 and the second flow amplifier 16 respectively.

[0053] The STR1 port and the STR2 port of the steering valve group 1 are respectively connected to the HP ports of the first flow amplifier 15 and the second flow amplifier 16; the P port, T port, L port, R port and LS port of the first flow amplifier 15 are respectively connected to the P port, T port, L port, R port and LS port of the first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 through the first converging valve group 17; the steering valve group 1 provides pressure oil to the first flow amplifier 15 and the second flow amplifier 16 respectively.

[0054] Step 3: The first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 receive the control signal and output the pilot pressure oil to the first flow amplifier 15; the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 receive the control signal and output the pilot pressure oil to the second flow amplifier 16. The first flow amplifier 15 controls the steering mechanism of the front axle, and the second flow amplifier 16 controls the steering mechanism of the rear axle;

[0055] The first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 output pilot pressure oil to the first flow amplifier 15 under the control of the electric signal. The CL port (oil outlet) and the CR port (oil outlet) of the first flow amplifier 15 are connected to the front axle steering cylinder to control the steering mechanism of the front axle. The excess pressure oil returns to the hydraulic oil tank 3 through the HT port of the first flow amplifier 15 and the return oil filter.

[0056] The P port, T port, L port, R port, and LS port of the second flow amplifier 16 are respectively connected to the P port, T port, L port, R port, and LS port of the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 through the second converging valve group 18; the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 output pilot pressure oil to control the second flow amplifier 16 under the control of the electric signal, and the CL port (oil outlet) and the CR port (oil outlet) of the second flow amplifier 16 are connected to the rear axle steering cylinder to control the steering mechanism of the rear axle. The excess pressure oil returns to the hydraulic oil tank 3 through the return oil filter of the HT port of the second flow amplifier 16.

[0057] When the vehicle is moving forward, the first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 control the first flow amplifier 15 to perform steering action on the front steering cylinder, so that the front wheels of the vehicle serve as active steering wheels; when the vehicle is moving backward, the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 control the second flow amplifier 16 to perform steering action on the rear steering cylinder, so that the rear wheels of the vehicle serve as active steering wheels.

[0058] Each individual flow amplifier (the first flow amplifier 15 / the second flow amplifier 16) is controlled in parallel by two electro-hydraulic steering valves (the first electro-hydraulic steering valve 9, the second electro-hydraulic steering valve 10, or the third electro-hydraulic steering valve 13, the fourth electro-hydraulic steering valve 14). Even if a single electro-hydraulic steering valve fails, the other electro-hydraulic steering valve can provide a control signal to ensure that the vehicle steering is not out of control, thereby realizing the dual redundant hydraulic steering function of the front and rear axles.

[0059] Example 1: Vehicle moving forward

[0060] The dual redundant hydraulic four-wheel steering system comprises: a steering valve group 1, a plunger pump 2, a hydraulic oil tank 3, a front axle left steering cylinder 7, a front axle right steering cylinder 8, a first electro-hydraulic steering valve (EHI) 9, a second electro-hydraulic steering valve (EHI) 10, a first flow amplifier 15, and a first converging valve group 17.

[0061] The hydraulic oil is converted into high-pressure oil by the plunger pump 2 and enters the P1 port (oil inlet) of the steering valve group 1 through the pipeline. The STR1 port (oil outlet) and the STR2 port (oil outlet) of the steering valve group 1 are respectively connected to the HP port (oil inlet) of the first flow amplifier 15 through pipelines; the L port, R port, P port, T port and LS port of the first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 are respectively connected to the L port, R port, P port, T port and LS port of the first flow amplifier 15 through the first converging valve group 17; the CL port and the CR port of the first flow amplifier 15 are respectively connected to the front axle steering cylinders (front axle left steering cylinder 7 and front axle right steering cylinder 8) through pipelines to control the steering of the front wheels; and return to the hydraulic oil tank 3 through the T of the steering valve group 1 of the first flow amplifier 15.

[0062] The plunger pump 2 is used to pressurize the hydraulic oil. The oil inlet of the plunger pump 2 is connected to the hydraulic oil tank 3 through a pipeline, and the oil outlet of the plunger pump 2 is connected to the P1 port (oil inlet) of the steering valve group 1 through a pipeline; the plunger pump 2 is a constant pressure variable pump.

[0063] The steering valve group 1 is used to provide pressure oil to the first flow amplifier 15, the T port (oil return port) is connected to the oil tank 3 through a pipeline, and the STR1 port (oil outlet) of the steering valve group 1 is connected to the HP port of the first flow amplifier 15 through a pipeline;

[0064] The first electro-hydraulic steering valve 9 receives the control signal and outputs the first flow amplifier 15 of the pilot pressure oil, and the P port (oil inlet) and the T port (oil return port) are respectively connected to the P port and the T port of the first flow amplifier 15 through pipelines; the L port (oil inlet) of the first electro-hydraulic steering valve 9 is connected to the L1 port (oil inlet) of the first converging valve group 17 through a pipeline, the R port (oil return port) is connected to the R1 port (oil return port) of the first converging valve group 17 through a pipeline, and the LS1 port (oil outlet) is connected to the LS2 port (oil outlet) of the first converging valve group 17 through a pipeline;

[0065] The second electro-hydraulic steering valve 10 receives the control signal and outputs the pilot pressure oil to the second flow amplifier 16. The P port (oil inlet) and the T port (oil return port) are respectively connected to the P port and the T port of the first flow amplifier 15 through the pipeline; the L port (oil inlet) of the second electro-hydraulic steering valve 10 is connected to the L2 port (oil inlet) of the first converging valve group 17, and the R port (oil return port) of the second electro-hydraulic steering valve 10 is connected to the R2 port (oil return port) of the first converging valve group 17; the LS1 port (oil outlet) of the second electro-hydraulic steering valve 10 is connected to the LS3 port (oil outlet) of the first converging valve group 17 through the pipeline;

[0066] The first flow amplifier 15 is used to control the steering mechanism action of the front axle, the L port (oil inlet) is connected to the L3 port (oil inlet) of the first merging valve group 17 through a pipeline, the R port is connected to the R3 port (oil return port) of the first merging valve group 17 through a pipeline, and the LS port (oil outlet) is connected to the LS1 port (oil outlet) of the first merging valve group 17 through a pipeline; the CL of the first flow amplifier 15 is connected to the C1 port of the left steering cylinder 7 of the front axle, and is connected to the C2 port of the right steering cylinder 8 of the front axle; the CR of the first flow amplifier 15 is connected to the C2 port of the left steering cylinder 7 of the front axle, and is connected to the C2 port of the right steering cylinder 8 of the front axle; the HT port (oil return port) of the first flow amplifier 15 is connected to the oil tank 3 through pipelines.

[0067] The dual redundant hydraulic four-wheel steering method for unmanned mining dump trucks has the following specific steps:

[0068] Step 1: The plunger pump 2 outputs pressure oil to the steering valve group 1;

[0069] Step 2: The steering valve group 1 provides pressure oil to the first flow amplifier 15 .

[0070] The STR1 port and the STR2 port of the steering valve group 1 are connected to the HP port of the first flow amplifier 15, and the P port, T port, L port, R port and LS port of the first flow amplifier 15 are respectively connected to the P port, T port, L port, R port and LS port of the first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 through the first converging valve group 17; the steering valve group 1 provides pressure oil for the first flow amplifier 15.

[0071] Step 3: The first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 receive the control signal and output the pilot pressure oil to the first flow amplifier 15; the first flow amplifier 15 controls the steering mechanism of the front axle;

[0072] The first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 output pilot pressure oil to the first flow amplifier 15 under the control of the electric signal. The CL port (oil outlet) and the CR port (oil outlet) of the first flow amplifier 15 are connected to the front axle steering cylinder to control the steering mechanism of the front axle. The excess pressure oil returns to the hydraulic oil tank 3 through the HT port of the first flow amplifier 15 and the return oil filter.

[0073] When the vehicle is moving forward, the first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 control the first flow amplifier 15 to implement steering action on the front steering cylinder, so that the front wheels of the vehicle serve as active steering wheels. Each individual flow amplifier (first flow amplifier 15) is controlled in parallel by two electro-hydraulic steering valves (first electro-hydraulic steering valve 9 and second electro-hydraulic steering valve 10). Even if a single electro-hydraulic steering valve fails, the other electro-hydraulic steering valve can provide a control signal to ensure that the vehicle steering does not lose control, thereby realizing the dual redundant hydraulic steering function of the front and rear axles.

[0074] Example 2: Vehicle driving backwards

[0075] The dual redundant hydraulic four-wheel steering system comprises: a steering valve group 1, a plunger pump 2, a hydraulic oil tank 3, a rear axle left steering cylinder 11, a rear axle right steering cylinder 12, a third electro-hydraulic steering valve (EHI) 13, a fourth electro-hydraulic steering valve 14, a second flow amplifier 16, and a second converging valve group 18.

[0076] The hydraulic oil is converted into high-pressure oil by the plunger pump 2 and enters the P1 port (oil inlet) of the steering valve group 1 through the pipeline. The STR2 port (oil outlet) of the steering valve group 1 is connected to the HP port (oil inlet) of the second flow amplifier 16 through the pipeline; the L port, R port, P port, T port, and LS port of the third electro-hydraulic steering gear 13 and the fourth electro-hydraulic steering valve 14 are respectively connected to the L port, R port, P port, T port, and LS port of the second flow amplifier 16 through the second converging valve group 18; the CL port (oil outlet) and CR port (oil outlet) of the second flow amplifier 16 are connected to the rear axle steering cylinder (rear axle left steering cylinder 11, rear axle right steering cylinder 12) to control the steering of the rear wheels, and return to the hydraulic oil tank 3 through the HT port of the second flow amplifier 16 and T of the steering valve group 1.

[0077] The plunger pump 2 is used to pressurize the hydraulic oil. The oil inlet of the plunger pump 2 is connected to the hydraulic oil tank 3 through a pipeline, and the oil outlet of the plunger pump 2 is connected to the P1 port (oil inlet) of the steering valve group 1 through a pipeline; the plunger pump 2 is a constant pressure variable pump.

[0078] The steering valve group 1 is used to provide pressure oil to the second flow amplifier 16, the T port (oil return port) is connected to the oil tank 3 through a pipeline, and the STR2 port (oil outlet) of the steering valve group 1 is connected to the HP port (oil inlet) of the second flow amplifier 16 through a pipeline;

[0079] The P port (oil inlet) and the T port (oil return port) of the third electro-hydraulic steering valve 13 are connected to the P port and the T port of the second flow amplifier 16 through pipelines, respectively; the L port (oil inlet) of the third electro-hydraulic steering valve 13 is connected to the L1 port (oil inlet) of the second converging valve group 18 through a pipeline; the R port (oil return port) of the third electro-hydraulic steering valve 13 is connected to the R1 port (oil return port) of the second converging valve group 18 through a pipeline; the LS1 port (oil outlet) of the third electro-hydraulic steering valve 13 is connected to the LS2 port (oil outlet) of the second converging valve group 18;

[0080] The P port (oil inlet) and T port (oil return port) of the fourth electro-hydraulic steering valve 14 are connected to the P port and T port of the second flow amplifier 16 through pipelines, respectively; the L port is connected to the L2 port (oil inlet) of the second converging valve group 18 through a pipeline; the R port (oil return port) is connected to the R2 port (oil return port) of the second converging valve group 18 through a pipeline; the LS1 (oil outlet) of the fourth electro-hydraulic steering valve 14 is connected to the LS3 (oil outlet) of the second converging valve group 18;

[0081] The second flow amplifier 16 controls the steering mechanism of the rear axle, the L port (oil inlet) is connected to the L3 port (oil inlet) of the second merging valve group 18 through a pipeline, the R port (oil return port) is connected to the R3 port (oil return port) of the second merging valve group 18 through a pipeline, and the LS port (oil outlet) is connected to the LS1 (oil outlet) of the second merging valve group 18;

[0082] The CL of the second flow amplifier 16 is connected to the C1 port of the rear axle left steering cylinder 11 and the C2 port of the rear axle right steering cylinder 12; the CR of the second flow amplifier 16 is connected to the C2 port of the rear axle left steering cylinder 11 and the C1 port of the rear axle right steering cylinder 12; the HT port (return oil port) of the second flow amplifier 16 is connected to the oil tank 3 through pipelines.

[0083] The dual redundant hydraulic four-wheel steering method for unmanned mining dump trucks has the following specific steps:

[0084] Step 1: The plunger pump 2 outputs pressure oil to the steering valve group 1;

[0085] Step 2: The steering valve group 1 provides pressure oil to the first flow amplifier 15 and the second flow amplifier 16 respectively.

[0086] The STR2 port of the steering valve group 1 is connected to the HP port of the second flow amplifier 16 , and the steering valve group 1 provides pressure oil to the second flow amplifier 16 .

[0087] Step 3: The third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 receive the control signal and output the pilot pressure oil to the second flow amplifier 16, and the second flow amplifier 16 controls the steering mechanism of the rear axle;

[0088] The P port, T port, L port, R port, and LS port of the second flow amplifier 16 are respectively connected to the P port, T port, L port, R port, and LS port of the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 through the second converging valve group 18; the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 output pilot pressure oil to control the second flow amplifier 16 under the control of the electric signal, and the CL port (oil outlet) and the CR port (oil outlet) of the second flow amplifier 16 are connected to the rear axle steering cylinder to control the steering mechanism of the rear axle. The excess pressure oil returns to the hydraulic oil tank 3 through the return oil filter of the HT port of the second flow amplifier 16.

[0089] When the vehicle travels backward, the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 control the second flow amplifier 16 to perform a steering action on the rear steering cylinder, so that the rear wheels of the vehicle serve as active steering wheels.

[0090] Each individual flow amplifier (the second flow amplifier 16) is controlled in parallel by two electro-hydraulic steering valves (the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14). Even if a single electro-hydraulic steering valve fails, the other electro-hydraulic steering valve can provide a control signal to ensure that the vehicle steering is not out of control, thereby realizing the dual redundant hydraulic steering function of the front and rear axles.

[0091] Embodiment 3: Based on Embodiment 1 or 2, an oil suction filter and a high-pressure filter 4 are provided before and after the plunger pump 2. The HT ports (return oil ports) of the first flow amplifier 15 and the second flow amplifier 16 are connected to return oil filters through pipelines, and the hydraulic oil returns to the oil tank 3 through the return oil filters. An electromagnetic reversing valve 1.1, a throttle valve 1.2, a safety valve 1.3, and a non-return valve 1.4 are provided between the P1 port and the T port inside the steering valve group 1, and the electromagnetic reversing valve 1.1, the throttle valve 1.2, the safety valve 1.3, and the non-return valve 1.4 are connected in series between the P1 port and the T port.

[0092] The dual redundant hydraulic four-wheel steering method for unmanned mining dump trucks has the following specific steps:

[0093] Step 1: The plunger pump 2 outputs pressure oil to the steering valve group 1;

[0094] The oil outlet of the plunger pump 2 is connected to the P1 port of the steering valve group 1 through the high-pressure filter 4. The hydraulic oil is converted into high-pressure oil through the plunger pump 2, and the high-pressure oil enters the steering valve group 1 through the oil suction filter.

[0095] Step 2: The steering valve group 1 provides pressure oil to the first flow amplifier 15 and the second flow amplifier 16 respectively.

[0096] After the pressure oil enters the steering valve group 1, it first passes through a one-way valve 1.4. The safety valve 1.3 protects the system components from being damaged by excessive pressure. The electromagnetic reversing valve 1.1 and the throttle valve 1.2 ensure that the accumulator pressure is released within a certain period of time after parking.

[0097] The STR1 port and the STR2 port of the steering valve group 1 are respectively connected to the HP ports of the first flow amplifier 15 and the second flow amplifier 16; the P port, T port, L port, R port and LS port of the first flow amplifier 15 are respectively connected to the P port, T port, L port, R port and LS port of the first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 through the first converging valve group 17; the steering valve group 1 provides pressure oil to the first flow amplifier 15 and the second flow amplifier 16 respectively.

[0098] Step 3: The first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 receive the control signal and output the pilot pressure oil to the first flow amplifier 15; the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 receive the control signal and output the pilot pressure oil to the second flow amplifier 16. The first flow amplifier 15 controls the steering mechanism of the front axle, and the second flow amplifier 16 controls the steering mechanism of the rear axle;

[0099] The first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 output pilot pressure oil to the first flow amplifier 15 under the control of the electric signal. The CL port (oil outlet) and the CR port (oil outlet) of the first flow amplifier 15 are connected to the front axle steering cylinder to control the steering mechanism of the front axle. The excess pressure oil returns to the hydraulic oil tank 3 through the HT port of the first flow amplifier 15 and the return oil filter.

[0100] The P port, T port, L port, R port, and LS port of the second flow amplifier 16 are respectively connected to the P port, T port, L port, R port, and LS port of the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 through the second converging valve group 18; the third electro-hydraulic steering valve 13 and the fourth electro-hydraulic steering valve 14 output pilot pressure oil to control the second flow amplifier 16 under the control of the electric signal, and the CL port (oil outlet) and the CR port (oil outlet) of the second flow amplifier 16 are connected to the rear axle steering cylinder to control the steering mechanism of the rear axle. The excess pressure oil returns to the hydraulic oil tank 3 through the return oil filter of the HT port of the second flow amplifier 16.

[0101] When the vehicle is moving forward, the first electro-hydraulic steering valve 9 and the second electro-hydraulic steering valve 10 control the first flow amplifier 15 to implement steering action on the front steering cylinder, so that the front wheels of the vehicle serve as active steering wheels;

[0102] Embodiment 4: Based on Embodiments 1 and 2, the A1 port, A2 port, and A3 port (working oil port) of the steering valve group 1 are provided with an accumulator 5, which provides pressure and flow to provide the system with an emergency steering function, meet the vehicle emergency steering requirements, and reduce the system pressure pulse.

[0103] Embodiment 5: The TSB ports (working oil ports) of the steering valve groups 1 and 2 are provided with pressure sensors, which are connected to the pressure switch 6 via a wire. When the steering pressure is low, the pressure switch 6 turns on the alarm device.

[0104] The above description and the accompanying drawings sufficiently illustrate the embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A dual redundant hydraulic four-wheel steering system, characterized in that: include: Steering valve group, plunger pump, hydraulic oil tank, front axle steering cylinder, first electro-hydraulic steering valve, second electro-hydraulic steering valve, first flow amplifier, first converging valve group; The plunger pump is used to pressurize the hydraulic oil, and its oil inlet is connected to the hydraulic oil tank through a pipeline, and its oil outlet is connected to the oil inlet P1 of the steering valve group through a pipeline; The steering valve group is used to provide pressure oil to the first flow amplifier, the oil return port T is connected to the oil tank through a pipeline, and the oil outlet STR1 of the steering valve group is connected to the oil inlet HP of the first flow amplifier through a pipeline; The first electro-hydraulic steering valve and the second electro-hydraulic steering valve receive the control signal and output the pilot pressure oil to the first flow amplifier. The oil inlet, oil return port and oil outlet of the first electro-hydraulic steering valve and the second electro-hydraulic steering valve are respectively connected to the oil inlet, oil return port and oil outlet of the first flow amplifier through the first converging valve group; The first flow amplifier is used to control the steering mechanism action of the front axle, and its oil outlet is connected to the front axle steering cylinder through a pipeline. The front axle steering cylinder is used to control the steering of the front wheels.

2. The dual redundant hydraulic four-wheel steering system according to claim 1, characterized in that: Also includes: The second flow amplifier, the rear axle steering cylinder, the third electro-hydraulic steering valve, the fourth electro-hydraulic steering valve, and the second converging valve group; the steering valve group is used to provide pressure oil to the first flow amplifier and the second flow amplifier, and the oil outlet STR2 is connected to the oil inlet HP of the second flow amplifier through a pipeline; the third electro-hydraulic steering gear and the fourth electro-hydraulic steering valve respectively receive control signals and output pilot pressure oil to the second flow amplifier, and their oil inlet, oil return port and oil outlet are correspondingly connected to the oil inlet, oil return port and oil outlet of the second flow amplifier through the second converging valve group; the second flow amplifier is used to control the steering mechanism action of the rear axle, and its oil outlet is connected to the rear axle steering cylinder through a pipeline, and the rear axle steering cylinder is used to control the steering of the rear wheels.

3. The dual redundant hydraulic four-wheel steering system according to claim 2, characterized in that: The front axle steering cylinder includes: a front axle left steering cylinder and a front axle right steering cylinder. The oil outlet CL and the oil outlet CR of the first flow amplifier are respectively connected to the front axle left steering cylinder and the front axle right steering cylinder through pipelines; the oil outlet CL and the oil outlet CR of the second flow amplifier are respectively connected to the rear axle left steering cylinder and the rear axle right steering cylinder through pipelines, and the return oil ports of the first flow amplifier, the second flow amplifier and the steering valve group are connected to the hydraulic oil tank through pipelines.

4. The dual redundant hydraulic four-wheel steering system according to claim 2, characterized in that: The hydraulic oil is converted into high-pressure oil by the plunger pump and enters the P1 port of the steering valve group through the pipeline. The STR1 port and STR2 port of the steering valve group are connected to the HP port of the first flow amplifier and the HP port of the second flow amplifier through pipelines respectively; the L port, R port, P port, T port and LS port of the first electro-hydraulic steering valve and the second electro-hydraulic steering valve are respectively connected to the L port, R port, P port, T port and LS port of the first flow amplifier through the first confluence valve group; the L port, R port, P port, T port and LS port of the third electro-hydraulic steering gear and the fourth electro-hydraulic steering valve are respectively connected to the L port, R port, P port, T port and LS port of the second flow amplifier through the second confluence valve group; the CL port and CR port of the first flow amplifier are respectively connected to the front axle left steering cylinder and the front axle right steering cylinder through pipelines to control the steering of the front wheels; the CL port and CR port of the second flow amplifier are connected to the rear axle left steering cylinder and the rear axle right steering cylinder to control the steering of the rear wheels, and return to the hydraulic oil tank through the HT port of the first flow amplifier, the second flow amplifier and the T of the steering valve group.

5. The dual redundant hydraulic four-wheel steering system according to claim 2, characterized in that: The steering valve group is an integrated valve, including: a solenoid reversing valve, a throttle valve, a safety valve, and a one-way valve. Accumulators are installed at its A1, A2, and A3 ports, wherein the safety valve is installed between the P1 port, the P2 port, and the T port; the solenoid reversing valve is located between the P1 port and the T port; the throttle valve is located between the solenoid reversing valve and the P port; the one-way valve is located after the P1 port and before the A1 port and the A2 port.

6. The dual redundant hydraulic four-wheel steering system according to claim 2, characterized in that: The TSB port of the steering valve group is provided with a pressure sensor, and the pressure sensor is connected to the pressure switch through a wire.

7. An unmanned mining dump truck, characterized in that: A dual-redundant hydraulic four-wheel steering system comprising any one of claims 1-6.

8. The dual redundant hydraulic four-wheel steering method for an unmanned mining dump truck according to claim 7, characterized in that: include: The plunger pump outputs pressure oil to the steering valve group, and the steering valve group provides pressure oil to the first flow amplifier and the second flow amplifier respectively; The first electro-hydraulic steering valve and the second electro-hydraulic steering valve receive a control signal and output pilot pressure oil to the first flow amplifier; the third electro-hydraulic steering valve and the fourth electro-hydraulic steering valve receive a control signal and output pilot pressure oil to the second flow amplifier. The first flow amplifier controls the steering mechanism of the front axle, and the second flow amplifier controls the steering mechanism of the rear axle.

9. The dual redundant hydraulic four-wheel steering method for an unmanned mining dump truck according to claim 8, characterized in that: When the vehicle is moving forward, the first electro-hydraulic steering valve and the second electro-hydraulic steering valve control the first flow amplifier to perform steering action on the front steering cylinder, so that the front wheels of the vehicle serve as active steering wheels; when the vehicle is moving backward, the third electro-hydraulic steering valve and the fourth electro-hydraulic steering valve control the second flow amplifier to perform steering action on the rear steering cylinder, so that the rear wheels of the vehicle serve as active steering wheels.

10. The dual redundant hydraulic four-wheel steering method for an unmanned mining dump truck according to claim 8, characterized in that: The first electro-hydraulic steering valve and the second electro-hydraulic steering valve output pilot pressure oil to the first flow amplifier under the control of the electrical signal. The oil outlet CL and the oil outlet CR of the first flow amplifier are connected to the front axle steering cylinder to control the steering mechanism of the front axle, and the excess pressure oil returns to the hydraulic oil tank through the HT port and the return oil filter of the first flow amplifier; the third electro-hydraulic steering valve and the fourth electro-hydraulic steering valve output pilot pressure oil to control the second flow amplifier under the control of the electrical signal. The oil outlet CL and the oil outlet CR of the second flow amplifier 16 are connected to the rear axle steering cylinder to control the steering mechanism of the rear axle, and the excess pressure oil returns to the hydraulic oil tank through the return oil filter of the HT port of the second flow amplifier.

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