Unmanned mining dump truck with electric wheels and four-wheel hydraulic steering system and method

Abstract

The invention discloses a four-wheel hydraulic steering system which comprises a first electro-hydraulic steering gear, a first flow amplifier, a front axle left steering cylinder, a front axle right steering cylinder, a steering valve set, a plunger pump and a hydraulic oil tank. The plunger pump is used for generating pressure oil and providing pressure and flow for hydraulic oil of the system; the steering valve set is used for providing pressure oil for the first flow amplifier, the first flow amplifier is used for controlling the front axle steering cylinder to act, the first electro-hydraulic steering gear is used for providing pilot control oil for the first flow amplifier, and the front axle steering cylinder serves as an execution device and is used for driving a front wheel steering mechanism of a vehicle to complete steering. The hydraulic oil tank is used for storing hydraulic oil. The invention further discloses an unmanned mining dump truck with the electric wheels and a four-wheel hydraulic steering method. The two flow amplifiers are controlled through the two electro-hydraulic steering gears to achieve steering actions of the front steering cylinder and the rear steering cylinder, and the steering requirement of bidirectional driving is met.

Description

Technical Field

[0001] The invention belongs to the field of electric wheel mining dump trucks, and in particular relates to an unmanned electric wheel mining dump truck, a four-wheel hydraulic 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. Summary of the invention

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

[0005] To achieve the above objectives, the technical solutions used in the present invention are:

[0006] The four-wheel hydraulic steering system includes: a first electro-hydraulic steering gear, a first flow amplifier, a front axle left steering cylinder, a front axle right steering cylinder, a steering valve group, a plunger pump, and a hydraulic oil tank;

[0007] The plunger pump is used to generate pressure oil. The oil inlet is connected to the hydraulic oil tank through a pipeline, and the oil outlet pipeline is connected to the oil inlet P of the steering valve group to provide pressure and flow for the hydraulic oil of the system;

[0008] The steering valve group is used to provide pressure oil to the first flow amplifier, the return oil port T is connected to the oil tank through a pipeline, and the working oil port P1 is connected to the main oil inlet HP of the first flow amplifier through a pipeline;

[0009] The first flow amplifier is used to control the action of the front axle steering cylinder. The right working oil port CL is connected to the oil outlet C1 of the front axle left steering cylinder and the oil inlet C2 of the front axle right steering cylinder through pipelines; the left working oil port CR of the first flow amplifier is connected to the oil inlet C2 of the front axle left steering cylinder and the oil outlet C1 of the front axle right steering cylinder through pipelines;

[0010] The first electro-hydraulic steering gear is used to provide pilot control oil for the first flow amplifier, and the oil inlet L, the oil return port R, the oil inlet P, the oil return port T, and the oil outlet LS are respectively connected to the L port, the R port, the P port, the T port, and the LS port of the first flow amplifier through pipelines;

[0011] The front axle steering cylinder includes: a front axle left steering cylinder and a front axle right steering cylinder, which are used as actuators to drive the front wheel steering mechanism of the vehicle to complete the steering;

[0012] Hydraulic oil tank, used for storing hydraulic oil.

[0013] Further, the working oil port P2 of the steering valve group is connected to the main oil inlet HP of the second flow amplifier through a pipeline; including:

[0014] The second flow amplifier is used to control the action of the rear axle steering cylinder. The right working oil port CL is connected to the oil outlet C1 of the rear axle left steering cylinder and the oil inlet C2 of the rear axle right steering cylinder through pipelines; the CR port of the second flow amplifier is connected to the oil inlet C2 of the rear axle left steering cylinder and the oil outlet C1 of the rear axle right steering cylinder through pipelines;

[0015] The second electro-hydraulic steering gear is used to provide pilot control oil for the second flow amplifier, and L, R, P, T, and LS are respectively connected to the L port, R, P, T port, and LS port of the second flow amplifier through pipelines;

[0016] The rear axle steering cylinder includes: a rear axle left steering cylinder and a rear axle right steering cylinder, which serve as actuators to drive the vehicle's rear wheel steering mechanism to complete steering.

[0017] Furthermore, the steering hydraulic port AC of the steering valve group is connected to an accumulator through a pipeline, and the accumulator is used to provide the system with pressure oil for emergency steering.

[0018] Furthermore, the oil return port T of the steering valve group is connected to a first oil return filter through a pipeline, and the first oil return filter is connected to the hydraulic oil tank through a pipeline.

[0019] 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. The safety valve is installed between P1, P2 and T; the solenoid reversing valve is installed between P1, P2 and T; the throttle valve is installed between the solenoid reversing valve and T; the one-way valve is installed after P and before P1 and P2.

[0020] Furthermore, the plunger pump is a constant pressure variable displacement pump, the oil inlet of the plunger pump is provided with an oil suction filter, and the oil outlet is provided with a high pressure filter.

[0021] Furthermore, the main oil return port HT of the first flow amplifier is connected to the second oil return filter through a pipeline, and the second oil return filter is connected to the hydraulic oil tank through a pipeline; the main oil return port HT of the second flow amplifier is connected to the third oil return filter through a pipeline, and the third oil return filter is connected back to the hydraulic oil tank through a pipeline.

[0022] The unmanned electric wheel mining dump truck comprises: a front wheel steering mechanism, a rear wheel steering mechanism, and a four-wheel hydraulic steering system. The front axle left steering cylinder and the front axle right steering cylinder are respectively connected to the front wheel steering mechanism through pipelines, and the rear axle left steering cylinder and the rear axle right steering cylinder are respectively connected to the rear wheel steering mechanism through pipelines.

[0023] Four-wheel hydraulic steering method, including:

[0024] The hydraulic oil is converted into high-pressure oil by the plunger pump and enters the steering valve group, and the steering valve group provides pressure oil for the first flow amplifier;

[0025] The first electro-hydraulic steering gear is controlled to output pilot pressure oil to the first flow amplifier, the first flow amplifier drives the front axle steering cylinder to operate, and the front axle steering cylinder drives the front wheel steering mechanism of the vehicle to complete the steering.

[0026] Preferably, the steering valve group provides pressure oil for the second electro-hydraulic steering gear, the second electro-hydraulic steering gear is controlled to output pilot pressure oil to the second control flow amplifier, the second control flow amplifier drives the rear axle steering cylinder to move, and the rear axle steering cylinder drives the rear wheel steering mechanism of the vehicle to complete the steering.

[0027] The technical effects of the present invention include:

[0028] The present invention controls two flow amplifiers through two electro-hydraulic steering gears to realize the steering action of the front axle steering cylinder and the rear axle steering cylinder, thereby meeting the steering requirement of bidirectional driving.

[0029] Two electro-hydraulic steering gears (the first electro-hydraulic steering gear and the second electro-hydraulic steering gear) are used to provide pilot control oil for two flow amplifiers (the first flow amplifier and the second flow amplifier) ​​respectively. The two flow amplifiers control the front axle steering cylinder and the rear axle steering cylinder respectively to ensure that the steering system can be switched when the vehicle is driving backward to reverse the direction forward. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The invention discloses a schematic structural diagram of a four-wheel hydraulic steering system for an unmanned electric wheel mining dump truck.

[0031] Among them: 1. The first electro-hydraulic steering gear; 2. The second electro-hydraulic steering gear; 3. The first flow amplifier; 4. The second flow amplifier; 5. The left steering cylinder of the front axle; 6. The right steering cylinder of the front axle; 7. The left steering cylinder of the rear axle; 8. The right steering cylinder of the rear axle; 9. The steering valve group; 9.1. The electromagnetic reversing valve; 9.2. The throttle valve; 9.3. The safety valve; 9.4. The one-way valve; 10. The accumulator; 11. The first return oil filter; 12. The high-pressure filter; 13. The plunger pump; 14. The oil suction filter; 15. The second return oil filter; 16. The third return oil filter; 17. The hydraulic oil tank. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Unless otherwise stated, the term "plurality" means two or more.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] like Figure 1 The figure is a schematic diagram of the structure of the four-wheel hydraulic steering system of the unmanned electric wheel mining dump truck in the present invention.

[0041] The four-wheel hydraulic steering system of the unmanned electric wheel mining dump truck includes: a first electro-hydraulic steering gear 1, a second electro-hydraulic steering gear 2, a first flow amplifier 3, a second flow amplifier 4, a front axle left steering cylinder 5, a front axle right steering cylinder 6, a rear axle left steering cylinder 7, a rear axle right steering cylinder 8, a steering valve group 9, an accumulator 10, a first return oil filter 11, a high-pressure filter 12, a plunger pump 13, an oil suction filter 14, a second return oil filter 15, and a hydraulic oil tank 17;

[0042] The plunger pump 13 is used to generate pressure oil. The oil inlet is connected to the hydraulic oil tank 17 through a pipeline, and the oil outlet pipeline is connected to the P port (oil inlet) of the steering valve group 9 to provide pressure and flow for the hydraulic oil of the system;

[0043] The steering valve group 9 is used to provide pressure oil to the first flow amplifier 3 and the second flow amplifier 4. The T port (return oil port) is connected to the oil tank 17 through a pipeline, the P1 port (working oil port) is connected to the HP port (main oil inlet port) of the first flow amplifier 3 through a pipeline, and the P2 port (working oil port) is connected to the HP port (main oil inlet port) of the second flow amplifier 4 through a pipeline;

[0044] The first flow amplifier 3 is used to control the action of the front axle steering cylinder. The CL port (right working oil port) is connected to the C1 port (oil outlet) of the front axle left steering cylinder 5 and the C2 port (oil inlet) of the front axle right steering cylinder 6 through pipelines; the CR port (left working oil port) of the first flow amplifier 3 is connected to the C2 port (oil inlet) of the front axle left steering cylinder 5 and the C1 port (oil outlet) of the front axle right steering cylinder 6 through pipelines;

[0045] The second flow amplifier 4 is used to control the action of the rear axle steering cylinder. The CL port (right working oil port) is connected to the C1 port (oil outlet) of the rear axle left steering cylinder 7 and the C2 port (oil inlet) of the rear axle right steering cylinder 8 through pipelines; the CR port of the second flow amplifier 4 is connected to the C2 port (oil inlet) of the rear axle left steering cylinder 7 and the C1 port (oil outlet) of the rear axle right steering cylinder 8 through pipelines;

[0046] The first electro-hydraulic steering gear 1 is used to provide pilot control oil for the first flow amplifier 3, and the L port (oil inlet), R port (oil return port), P port (oil inlet), T port (oil return port), and LS port (oil outlet) are respectively connected to the L port, R port, P port, T port, and LS port of the first flow amplifier 3 through pipelines;

[0047] The second electro-hydraulic steering gear 2 is used to provide pilot control oil for the second flow amplifier 4, and the L port (oil inlet), R port (oil return port), P port (oil inlet), T port (oil return port), and LS port (oil outlet) are respectively connected to the L port, R port, P port, T port, and LS port of the second flow amplifier 4 through pipelines;

[0048] The hydraulic oil tank 17 is used for storing hydraulic oil.

[0049] The front axle steering cylinder includes: a front axle left steering cylinder 5 and a front axle right steering cylinder 6, which are used as actuators to drive the vehicle front wheel steering mechanism to complete the steering;

[0050] The rear axle steering cylinders include: a rear axle left steering cylinder 7 and a rear axle right steering cylinder 8, which serve as actuators for driving the vehicle rear wheel steering mechanism to complete steering.

[0051] The AC port (steering hydraulic port) of the steering valve group 9 is connected to an accumulator 10, which provides the system with pressure oil for emergency steering; the T port (return oil port) is connected to a first return oil filter 11 through a pipeline, and the hydraulic oil returns to the hydraulic oil tank 17 through the first return oil filter 11.

[0052] The steering valve group 9 is an integrated valve, and a safety valve, an electromagnetic stop valve and a one-way valve are arranged inside the steering valve group 9. The steering valve group 9 includes: an electromagnetic reversing valve 9.1, a throttle valve 9.2, a safety valve 9.3, a one-way valve 9.4, and an accumulator 10 is installed at the AC port, wherein the safety valve is installed between the P1 port, the P2 port and the T port; the electromagnetic reversing valve 9.1 is installed between the P1 port, the P2 port and the T port; the throttle valve 9.2 is installed between the electromagnetic reversing valve 9.1 and the T port; and the one-way valve 9.4 is installed after the P port and before the P1 port and the P2 port.

[0053] The oil inlet of the plunger pump 13 is provided with an oil suction filter 14, and the oil outlet is provided with a high-pressure filter 12. The plunger pump 13 is a constant-pressure variable displacement pump.

[0054] The HT port (main oil return port) of the first flow amplifier 3 is connected to the second oil return filter 15 through a pipeline, and the second oil return filter 15 is connected to the hydraulic oil tank 17 through a pipeline;

[0055] The HT port (main oil return port) of the second flow amplifier 4 is connected to the third oil return filter 16 through a pipeline, and the third oil return filter 16 is connected back to the hydraulic oil tank 17 through a pipeline;

[0056] The hydraulic oil T ports of the first flow amplifier 3, the second flow amplifier 4 and the steering valve group 9 are returned to the hydraulic oil tank 17 through a separate return oil filter to ensure the cleanliness of the hydraulic system.

[0057] The four-wheel hydraulic steering method of the unmanned electric wheel mining dump truck is as follows:

[0058] Step 1: The hydraulic oil is converted into high-pressure oil by the plunger pump 13 and enters the steering valve group 9;

[0059] An oil suction filter 14 and a high-pressure filter 12 are arranged before and after the plunger pump 13. After the pressure oil enters the steering valve group 9, it first passes through a one-way valve 9.4.

[0060] A safety valve 9.4 is provided between the P port and the T port of the steering valve group 9 to protect the system components from being damaged by excessive pressure; an electromagnetic reversing valve 9.1 is also provided between the P port and the T port of the steering valve group 9 to ensure that the accumulator pressure is released within a certain period of time after parking;

[0061] An accumulator 10 is provided at the AC port of the steering valve group 9 to provide pressure and flow to meet the emergency steering requirements of the vehicle and reduce the system pressure pulse.

[0062] Step 2: The steering valve group 9 provides pressure oil to the first flow amplifier 3 and the second flow amplifier 4 respectively;

[0063] Step 3: The first electro-hydraulic steering gear 1 is controlled to output pilot pressure oil to the first flow amplifier 3, the first flow amplifier 3 drives the front axle steering cylinder to operate, and the front axle steering cylinder drives the front wheel steering mechanism of the vehicle to complete the steering;

[0064] The P1 port and the P2 port of the steering valve group 9 are respectively connected to the HP ports of the first flow amplifier 3 and the second flow amplifier 4 to provide flow therefor, and the P port, T port, L port, R port and LS port of the first flow amplifier 3 are respectively connected to the P port, T port, L port, R port and LS port of the first electro-hydraulic steering gear 1. The first electro-hydraulic steering gear 1 outputs a pilot pressure under the control of an electrical signal (the control port is connected to the steering controller) to control whether the first flow amplifier 3 is actuated.

[0065] The first flow amplifier 3 outputs pressure oil to the front axle steering cylinder of the vehicle, and the front axle steering cylinder drives the front wheel steering mechanism of the vehicle to complete the steering. The CL port and CR port of the first flow amplifier 3 are connected to the front axle steering cylinder, and the front axle steering cylinder controls the steering mechanism of the front axle; the hydraulic oil returns to the hydraulic oil tank 17 through the HT port of the first flow amplifier 3 and the return oil filter 15.

[0066] Step 4: The second electro-hydraulic steering gear 2 is controlled to output pilot pressure oil to the second control flow amplifier 4, the second control flow amplifier 4 drives the rear axle steering cylinder to operate, and the rear axle steering cylinder drives the rear wheel steering mechanism of the vehicle to complete the steering.

[0067] The P port, T port, L port, R port and LS port of the second flow amplifier 4 are respectively connected to the P port, T port, L port, R port and LS port of the second electro-hydraulic steering gear 2. The second electro-hydraulic steering gear 2 can output pilot pressure oil to the second control flow amplifier 4 under the control of electrical signals. The CL and CR ports of the second control flow amplifier 4 are connected to the rear axle steering cylinder, and the rear axle steering cylinder controls the action of the steering mechanism of the rear axle. The hydraulic oil returns to the hydraulic oil tank 17 through the HT port of the front axle steering cylinder and the return oil filter 16.

[0068] Example 1: Front wheels as active steering wheels

[0069] The four-wheel hydraulic steering system of the unmanned electric wheel mining dump truck includes: a first electro-hydraulic steering gear 1, a first flow amplifier 3, a front axle left steering cylinder 5, a front axle right steering cylinder 6, a steering valve group 9, a plunger pump 13, and a hydraulic oil tank 17.

[0070] The plunger pump 13 is used to generate pressure oil. The oil inlet is connected to the hydraulic oil tank 17 through a pipeline, and the oil outlet pipeline is connected to the P port (oil inlet) of the steering valve group 9 to provide pressure and flow for the hydraulic oil of the system;

[0071] The steering valve group 9 is used to provide pressure oil to the first flow amplifier 3, the T port (return oil port) is connected to the oil tank 17 through a pipeline, and the P1 port (working oil port) is connected to the HP port (main oil inlet port) of the first flow amplifier 3 through a pipeline;

[0072] The first flow amplifier 3 is used to control the action of the front axle steering cylinder. The CL port (right working oil port) is connected to the C1 port (oil outlet) of the front axle left steering cylinder 5 and the C2 port (oil inlet) of the front axle right steering cylinder 6 through pipelines; the CR port (left working oil port) of the first flow amplifier 3 is connected to the C2 port (oil inlet) of the front axle left steering cylinder 5 and the C1 port (oil outlet) of the front axle right steering cylinder 6 through pipelines;

[0073] The first electro-hydraulic steering gear 1 is used to provide pilot control oil for the first flow amplifier 3, and the L port (oil inlet), R port (oil return port), P port (oil inlet), T port (oil return port), and LS port (oil outlet) are respectively connected to the L port, R port, P port, T port, and LS port of the first flow amplifier 3 through pipelines;

[0074] The hydraulic oil tank 17 is used for storing hydraulic oil.

[0075] The front axle steering cylinder includes: a front axle left steering cylinder 5 and a front axle right steering cylinder 6, which are used as actuators to drive the vehicle front wheel steering mechanism to complete the steering;

[0076] The four-wheel hydraulic steering method of the unmanned electric wheel mining dump truck is as follows:

[0077] Step 1: The hydraulic oil is converted into high-pressure oil by the plunger pump 13 and enters the steering valve group 9;

[0078] Step 2: The steering valve group 9 provides pressure oil to the first flow amplifier 3;

[0079] Step 3: The first electro-hydraulic steering gear 1 is controlled to output pilot pressure oil to the first flow amplifier 3, the first flow amplifier 3 drives the front axle steering cylinder to operate, and the front axle steering cylinder drives the front wheel steering mechanism of the vehicle to complete the steering.

[0080] The P1 port and the P2 port of the steering valve group 9 are respectively connected to the HP ports of the first flow amplifier 3 and the second flow amplifier 4 to provide flow therefor, and the P port, T port, L port, R port and LS port of the first flow amplifier 3 are respectively connected to the P port, T port, L port, R port and LS port of the first electro-hydraulic steering gear 1. The first electro-hydraulic steering gear 1 outputs a pilot pressure under the control of an electrical signal (the control port is connected to the steering controller) to control whether the first flow amplifier 3 is actuated.

[0081] The first flow amplifier 3 outputs pressure oil to the front axle steering cylinder of the vehicle, and the front axle steering cylinder drives the front wheel steering mechanism of the vehicle to complete the steering. The CL port and the CR port of the first flow amplifier 3 are connected to the front axle steering cylinder, and the front axle steering cylinder controls the steering mechanism of the front axle; the hydraulic oil returns to the hydraulic oil tank 17 through the HT port of the first flow amplifier 3.

[0082] When the vehicle is moving forward, the first electro-hydraulic steering gear 1 controls the first flow amplifier 3 to perform a steering action on the front steering cylinder, so that the front wheels of the vehicle serve as active steering wheels.

[0083] Example 2: Rear wheels as active steering wheels

[0084] The four-wheel hydraulic steering system of the unmanned electric wheel mining dump truck includes: a second electro-hydraulic steering gear 2, a second flow amplifier 4, a rear axle left steering cylinder 7, a rear axle right steering cylinder 8, a steering valve group 9, a plunger pump 13, and a hydraulic oil tank 17.

[0085] The plunger pump 13 is used to generate pressure oil. The oil inlet is connected to the hydraulic oil tank 17 through a pipeline, and the oil outlet pipeline is connected to the P port (oil inlet) of the steering valve group 9 to provide pressure and flow for the hydraulic oil of the system;

[0086] The steering valve group 9 is used to provide pressure oil to the second flow amplifier 4, the T port (return oil port) is connected to the oil tank 17 through a pipeline, and the P2 port (working oil port) is connected to the HP port (main oil inlet port) of the second flow amplifier 4 through a pipeline;

[0087] The second flow amplifier 4 is used to control the action of the rear axle steering cylinder. The CL port (right working oil port) is connected to the C1 port (oil outlet) of the rear axle left steering cylinder 7 and the C2 port (oil inlet) of the rear axle right steering cylinder 8 through pipelines; the CR port of the second flow amplifier 4 is connected to the C2 port (oil inlet) of the rear axle left steering cylinder 7 and the C1 port (oil outlet) of the rear axle right steering cylinder 8 through pipelines;

[0088] The second electro-hydraulic steering gear 2 is used to provide pilot control oil for the second flow amplifier 4, and the L port (oil inlet), R port (oil return port), P port (oil inlet), T port (oil return port), and LS port (oil outlet) are respectively connected to the L port, R port, P port, T port, and LS port of the second flow amplifier 4 through pipelines;

[0089] The hydraulic oil tank 17 is used for storing hydraulic oil.

[0090] The rear axle steering cylinders include: a rear axle left steering cylinder 7 and a rear axle right steering cylinder 8, which serve as actuators for driving the vehicle rear wheel steering mechanism to complete steering.

[0091] The four-wheel hydraulic steering method of the unmanned electric wheel mining dump truck is as follows:

[0092] Step 1: The hydraulic oil is converted into high-pressure oil by the plunger pump 13 and enters the steering valve group 9;

[0093] Step 2: The steering valve group 9 provides pressure oil to the second flow amplifier 4;

[0094] Step 3: The second electro-hydraulic steering gear 2 is controlled to output pilot pressure oil to the second control flow amplifier 4, the second control flow amplifier 4 drives the rear axle steering cylinder to operate, and the rear axle steering cylinder drives the rear wheel steering mechanism of the vehicle to complete the steering.

[0095] The P port, T port, L port, R port and LS port of the second flow amplifier 4 are respectively connected to the P port, T port, L port, R port and LS port of the second electro-hydraulic steering gear 2. The second electro-hydraulic steering gear 2 can output pilot pressure oil to the second control flow amplifier 4 under the control of electrical signals. The CL and CR ports of the second control flow amplifier 4 are connected to the rear axle steering cylinder, which controls the action of the steering mechanism of the rear axle. The hydraulic oil returns to the hydraulic oil tank 17 through the HT port of the front axle steering cylinder.

[0096] When the vehicle travels backward, the second electro-hydraulic steering gear 2 controls the second flow amplifier 4 to perform a steering action on the rear steering cylinder, so that the rear wheels of the vehicle serve as active steering wheels.

[0097] Embodiment 3: The four-wheel hydraulic steering system of an unmanned electric wheel mining dump truck comprises: a first electro-hydraulic steering gear 1, a second electro-hydraulic steering gear 2, a first flow amplifier 3, a second flow amplifier 4, a front axle left steering cylinder 5, a front axle right steering cylinder 6, a rear axle left steering cylinder 7, a rear axle right steering cylinder 8, a steering valve group 9, an accumulator 10, a plunger pump 13, and a hydraulic oil tank 17.

[0098] The plunger pump 13 is a constant pressure variable displacement pump, which is used to generate pressure oil. The oil inlet is connected to the hydraulic oil tank 17 through a pipeline, and the oil outlet pipeline is connected to the P port (oil inlet) of the steering valve group 9 to provide pressure and flow for the hydraulic oil of the system;

[0099] The steering valve group 9 is used to provide pressure oil to the first flow amplifier 3 and the second flow amplifier 4. The T port (return oil port) is connected to the oil tank 17 through a pipeline, the P1 port (working oil port) is connected to the HP port (main oil inlet port) of the first flow amplifier 3 through a pipeline, and the P2 port (working oil port) is connected to the HP port (main oil inlet port) of the second flow amplifier 4 through a pipeline; the steering valve group 9 is an integrated valve, and a safety valve, an electromagnetic stop valve and a check valve are arranged inside the steering valve group 9. The steering valve group 9 includes: an electromagnetic reversing valve 9.1, a throttle valve 9.2, a safety valve 9.3, a check valve 9.4, and an accumulator 10 is installed at the AC port, wherein the safety valve is installed between the P1 port, the P2 port and the T port; the electromagnetic reversing valve 9.1 is installed between the P1 port, the P2 port and the T port; the throttle valve 9.2 is installed between the electromagnetic reversing valve 9.1 and the T port; the check valve 9.4 is installed after the P port and before the P1 port and the P2 port.

[0100] The first flow amplifier 3 is used to control the action of the front axle steering cylinder. The CL port (right working oil port) is connected to the C1 port (oil outlet) of the front axle left steering cylinder 5 and the C2 port (oil inlet) of the front axle right steering cylinder 6 through pipelines; the CR port (left working oil port) of the first flow amplifier 3 is connected to the C2 port (oil inlet) of the front axle left steering cylinder 5 and the C1 port (oil outlet) of the front axle right steering cylinder 6 through pipelines; the second return oil filter 15 is connected to the hydraulic oil tank 17 through a pipeline.

[0101] The second flow amplifier 4 is used to control the action of the rear axle steering cylinder. The CL port (right working oil port) is connected to the C1 port (oil outlet) of the rear axle left steering cylinder 7 and the C2 port (oil inlet) of the rear axle right steering cylinder 8 through pipelines; the CR port of the second flow amplifier 4 is connected to the C2 port (oil inlet) of the rear axle left steering cylinder 7 and the C1 port (oil outlet) of the rear axle right steering cylinder 8 through pipelines;

[0102] The first electro-hydraulic steering gear 1 is used to provide pilot control oil for the first flow amplifier 3, and the L port (oil inlet), R port (oil return port), P port (oil inlet), T port (oil return port), and LS port (oil outlet) are respectively connected to the L port, R port, P port, T port, and LS port of the first flow amplifier 3 through pipelines;

[0103] The second electro-hydraulic steering gear 2 is used to provide pilot control oil for the second flow amplifier 4, and the L port (oil inlet), R port (oil return port), P port (oil inlet), T port (oil return port), and LS port (oil outlet) are respectively connected to the L port, R port, P port, T port, and LS port of the second flow amplifier 4 through pipelines;

[0104] The hydraulic oil tank 17 is used for storing hydraulic oil.

[0105] The front axle steering cylinder includes: a front axle left steering cylinder 5 and a front axle right steering cylinder 6, which are used as actuators to drive the vehicle front wheel steering mechanism to complete the steering;

[0106] The rear axle steering cylinders include: a rear axle left steering cylinder 7 and a rear axle right steering cylinder 8, which serve as actuators for driving the vehicle rear wheel steering mechanism to complete steering.

[0107] The AC port (steering hydraulic port) of the steering valve group 9 is connected to an accumulator 10, which provides the system with pressurized oil for emergency steering.

[0108] The four-wheel hydraulic steering method of the unmanned electric wheel mining dump truck is as follows:

[0109] Step 1: The hydraulic oil is converted into high-pressure oil by the plunger pump 13 and enters the steering valve group 9; after entering the steering valve group 9, the pressure oil first passes through a one-way valve 9.4; a safety valve 9.4 is arranged between the P port and the T port of the steering valve group 9 to protect the system components from being damaged by excessive pressure; an electromagnetic reversing valve 9.1 is also arranged between the P port and the T port of the steering valve group 9 to ensure that the accumulator pressure is released within a certain period of time after parking; an accumulator 10 is arranged at the AC port of the steering valve group 9 to provide pressure and flow to meet the emergency steering requirements of the vehicle and reduce the system pressure pulse;

[0110] Step 2: The steering valve group 9 provides pressure oil to the first flow amplifier 3 and the second flow amplifier 4 respectively;

[0111] Step 3: The first electro-hydraulic steering gear 1 receives control and outputs pilot pressure oil to the first flow amplifier 3, the first flow amplifier 3 drives the front axle steering cylinder to operate, and the front axle steering cylinder drives the front wheel steering mechanism of the vehicle to complete the steering; the P1 port and the P2 port of the steering valve group 9 are respectively connected to the HP port of the first flow amplifier 3 and the second flow amplifier 4 to provide flow for them, the P port, T port, L port, R port, and LS port of the first flow amplifier 3 are respectively connected to the P port, T port, L port, R port, and LS port of the first electro-hydraulic steering gear 1, and the first electro-hydraulic steering gear 1 outputs the pilot pressure under the control of the electrical signal (the control port is connected to the steering controller) to control whether the first flow amplifier 3 operates; the hydraulic oil returns to the hydraulic oil tank 17 through the HT port of the first flow amplifier 3;

[0112] Step 4: The second electro-hydraulic steering gear 2 receives control and outputs pilot pressure oil to the second control flow amplifier 4. The second control flow amplifier 4 drives the rear axle steering cylinder to move, and the rear axle steering cylinder drives the rear wheel steering mechanism of the vehicle to complete the steering. The P port, T port, L port, R port, and LS port of the second flow amplifier 4 are respectively connected to the P port, T port, L port, R port, and LS port of the second electro-hydraulic steering gear 2. The second electro-hydraulic steering gear 2 can output pilot pressure oil to the second control flow amplifier 4 under the control of the electrical signal. The CL and CR ports of the second control flow amplifier 4 are connected to the rear axle steering cylinder, and the rear axle steering cylinder controls the movement of the steering mechanism of the rear axle. The hydraulic oil returns to the hydraulic oil tank 17 through the HT port of the front axle steering cylinder.

[0113] Embodiment 4: Based on Embodiment 3, a first return oil filter 11, a high-pressure filter 12, a second return oil filter 15, and an oil suction filter 14 are added.

[0114] The plunger pump 13 is a constant pressure variable displacement pump for generating pressurized oil. Its oil inlet is connected to the hydraulic oil tank 17 through a pipeline, and its oil outlet pipeline is connected to the P port (oil inlet) of the steering valve group 9 to provide pressure and flow for the hydraulic oil of the system. The oil inlet of the plunger pump 13 is provided with an oil suction filter 14, and the oil outlet is provided with a high-pressure filter 12.

[0115] The steering valve group 9 is used to provide pressure oil to the first flow amplifier 3 and the second flow amplifier 4. The T port (return oil port) is connected to the oil tank 17 through a pipeline, the P1 port (working oil port) is connected to the HP port (main oil inlet port) of the first flow amplifier 3 through a pipeline, and the P2 port (working oil port) is connected to the HP port (main oil inlet port) of the second flow amplifier 4 through a pipeline; the steering valve group 9 is an integrated valve, and a safety valve, an electromagnetic stop valve and a check valve are arranged inside the steering valve group 9. The steering valve group 9 includes: an electromagnetic reversing valve 9.1, a throttle valve 9.2, a safety valve 9.3, a check valve 9.4, and an accumulator 10 is installed at the AC port, wherein the safety valve is installed between the P1 port, the P2 port and the T port; the electromagnetic reversing valve 9.1 is installed between the P1 port, the P2 port and the T port; the throttle valve 9.2 is installed between the electromagnetic reversing valve 9.1 and the T port; the check valve 9.4 is installed after the P port and before the P1 port and the P2 port.

[0116] The first flow amplifier 3 is used to control the action of the front axle steering cylinder. The CL port (right working oil port) is connected to the C1 port (oil outlet) of the front axle left steering cylinder 5 and the C2 port (oil inlet) of the front axle right steering cylinder 6 through pipelines; the CR port (left working oil port) of the first flow amplifier 3 is connected to the C2 port (oil inlet) of the front axle left steering cylinder 5 and the C1 port (oil outlet) of the front axle right steering cylinder 6 through pipelines; the HT port (main oil return port) of the first flow amplifier 3 is connected to the second oil return filter 15 through a pipeline, and the second oil return filter 15 is connected to the hydraulic oil tank 17 through a pipeline; the hydraulic oil T port of the first flow amplifier 3, the second flow amplifier 4 and the steering valve group 9 returns to the hydraulic oil tank 17 through a separate oil return filter to ensure the cleanliness of the hydraulic system.

[0117] The second flow amplifier 4 is used to control the action of the rear axle steering cylinder. The CL port (right working oil port) is connected to the C1 port (oil outlet) of the rear axle left steering cylinder 7 and the C2 port (oil inlet) of the rear axle right steering cylinder 8 through pipelines; the CR port of the second flow amplifier 4 is connected to the C2 port (oil inlet) of the rear axle left steering cylinder 7 and the C1 port (oil outlet) of the rear axle right steering cylinder 8 through pipelines; the HT port (main oil return port) of the second flow amplifier 4 is connected to the third oil return filter 16 through a pipeline, and the third oil return filter 16 is connected back to the hydraulic oil tank 17 through a pipeline;

[0118] The first electro-hydraulic steering gear 1 is used to provide pilot control oil for the first flow amplifier 3, and the L port (oil inlet), R port (oil return port), P port (oil inlet), T port (oil return port), and LS port (oil outlet) are respectively connected to the L port, R port, P port, T port, and LS port of the first flow amplifier 3 through pipelines;

[0119] The second electro-hydraulic steering gear 2 is used to provide pilot control oil for the second flow amplifier 4, and the L port (oil inlet), R port (oil return port), P port (oil inlet), T port (oil return port), and LS port (oil outlet) are respectively connected to the L port, R port, P port, T port, and LS port of the second flow amplifier 4 through pipelines;

[0120] The hydraulic oil tank 17 is used for storing hydraulic oil.

[0121] The front axle steering cylinder includes: a front axle left steering cylinder 5 and a front axle right steering cylinder 6, which are used as actuators to drive the vehicle front wheel steering mechanism to complete the steering;

[0122] The rear axle steering cylinders include: a rear axle left steering cylinder 7 and a rear axle right steering cylinder 8, which serve as actuators for driving the vehicle rear wheel steering mechanism to complete steering.

[0123] The AC port (steering hydraulic port) of the steering valve group 9 is connected to an accumulator 10, which provides the system with pressure oil for emergency steering; the T port (return oil port) is connected to a first return oil filter 11 through a pipeline, and the hydraulic oil returns to the hydraulic oil tank 17 through the first return oil filter 11.

[0124] The four-wheel hydraulic steering method of the unmanned electric wheel mining dump truck is as follows:

[0125] Step 1: The hydraulic oil is converted into high-pressure oil through the plunger pump 13 and enters the steering valve group 9; an oil suction filter 14 and a high-pressure filter 12 are arranged before and after the plunger pump 13, and the pressure oil first passes through a one-way valve 9.4 after entering the steering valve group 9; a safety valve 9.4 is arranged between the P port and the T port of the steering valve group 9 to protect the system components from being damaged by excessive pressure; an electromagnetic reversing valve 9.1 is also arranged between the P port and the T port of the steering valve group 9 to ensure that the accumulator pressure is released within a certain period of time after parking; an accumulator 10 is arranged at the AC port of the steering valve group 9 to provide pressure and flow to meet the emergency steering requirements of the vehicle and reduce the system pressure pulse;

[0126] Step 2: The steering valve group 9 provides pressure oil to the first flow amplifier 3 and the second flow amplifier 4 respectively;

[0127] Step 3: The first electro-hydraulic steering gear 1 receives control and outputs pilot pressure oil to the first flow amplifier 3, the first flow amplifier 3 drives the front axle steering cylinder to operate, and the front axle steering cylinder drives the front wheel steering mechanism of the vehicle to complete the steering; the P1 port and the P2 port of the steering valve group 9 are respectively connected to the HP port of the first flow amplifier 3 and the second flow amplifier 4 to provide flow for them, the P port, T port, L port, R port, and LS port of the first flow amplifier 3 are respectively connected to the P port, T port, L port, R port, and LS port of the first electro-hydraulic steering gear 1, and the first electro-hydraulic steering gear 1 outputs the pilot pressure under the control of the electrical signal (the control port is connected to the steering controller) to control whether the first flow amplifier 3 operates; the hydraulic oil returns to the hydraulic oil tank 17 through the HT port of the first flow amplifier 3 and the return oil filter 15;

[0128] Step 4: The second electro-hydraulic steering gear 2 receives control and outputs pilot pressure oil to the second control flow amplifier 4. The second control flow amplifier 4 drives the rear axle steering cylinder to move, and the rear axle steering cylinder drives the rear wheel steering mechanism of the vehicle to complete the steering. The P port, T port, L port, R port, and LS port of the second flow amplifier 4 are respectively connected to the P port, T port, L port, R port, and LS port of the second electro-hydraulic steering gear 2. The second electro-hydraulic steering gear 2 can output pilot pressure oil to the second control flow amplifier 4 under the control of the electrical signal. The CL and CR ports of the second control flow amplifier 4 are connected to the rear axle steering cylinder, and the rear axle steering cylinder controls the steering mechanism of the rear axle. The hydraulic oil returns to the hydraulic oil tank 17 through the HT port of the front axle steering cylinder and the return oil filter 16.

[0129] The terms used in the present invention are illustrative and exemplary, rather than restrictive. Since the present invention can be implemented in various forms without departing from the spirit or essence of the technical solution, it should be understood that the above embodiments are not limited to any of the aforementioned details, but should be widely interpreted within the spirit and scope defined by the attached claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the attached claims.

Claims

1. A four-wheel hydraulic steering system, characterized in that: include: The first electro-hydraulic steering gear, the first flow amplifier, the front axle left steering cylinder, the front axle right steering cylinder, the steering valve group, the plunger pump, and the hydraulic oil tank; The plunger pump is used to generate pressure oil. The oil inlet is connected to the hydraulic oil tank through a pipeline, and the oil outlet pipeline is connected to the oil inlet P of the steering valve group to provide pressure and flow for the hydraulic oil of the system; The steering valve group is used to provide pressure oil to the first flow amplifier, the return oil port T is connected to the oil tank through a pipeline, and the working oil port P1 is connected to the main oil inlet HP of the first flow amplifier through a pipeline; The first flow amplifier is used to control the action of the front axle steering cylinder. The right working oil port CL is connected to the oil outlet C1 of the front axle left steering cylinder and the oil inlet C2 of the front axle right steering cylinder through pipelines; the left working oil port CR of the first flow amplifier is connected to the oil inlet C2 of the front axle left steering cylinder and the oil outlet C1 of the front axle right steering cylinder through pipelines; The first electro-hydraulic steering gear is used to provide pilot control oil for the first flow amplifier, and the oil inlet L, the oil return port R, the oil inlet P, the oil return port T, and the oil outlet LS are respectively connected to the L port, the R port, the P port, the T port, and the LS port of the first flow amplifier through pipelines; The front axle steering cylinder includes: a front axle left steering cylinder and a front axle right steering cylinder, which are used as actuators to drive the front wheel steering mechanism of the vehicle to complete the steering; Hydraulic oil tank, used for storing hydraulic oil.

2. The four-wheel hydraulic steering system according to claim 1, characterized in that: The working oil port P2 of the steering valve group is connected to the main oil inlet HP of the second flow amplifier through a pipeline; including: The second flow amplifier is used to control the action of the rear axle steering cylinder. The right working oil port CL is connected to the oil outlet C1 of the rear axle left steering cylinder and the oil inlet C2 of the rear axle right steering cylinder through pipelines; the CR port of the second flow amplifier is connected to the oil inlet C2 of the rear axle left steering cylinder and the oil outlet C1 of the rear axle right steering cylinder through pipelines; The second electro-hydraulic steering gear is used to provide pilot control oil for the second flow amplifier, and L, R, P, T, and LS are respectively connected to the L port, R, P, T port, and LS port of the second flow amplifier through pipelines; The rear axle steering cylinder includes: a rear axle left steering cylinder and a rear axle right steering cylinder, which serve as actuators to drive the vehicle's rear wheel steering mechanism to complete steering.

3. The four-wheel hydraulic steering system according to claim 1, characterized in that: The steering hydraulic port AC of the steering valve group is connected to an accumulator through a pipeline. The accumulator is used to provide the system with pressure oil for emergency steering.

4. The four-wheel hydraulic steering system according to claim 1, characterized in that: The oil return port T of the steering valve group is connected to a first oil return filter through a pipeline, and the first oil return filter is connected to a hydraulic oil tank through a pipeline.

5. The four-wheel hydraulic steering system according to claim 1, characterized in that: The steering valve group is an integrated valve, including: solenoid reversing valve, throttle valve, safety valve, and one-way valve. The safety valve is installed between P1, P2 and T; the solenoid reversing valve is installed between P1, P2 and T; the throttle valve is installed between the solenoid reversing valve and T; the one-way valve is installed after P and before P1 and P2.

6. The four-wheel hydraulic steering system according to claim 1, characterized in that: The plunger pump is a constant pressure variable displacement pump. The oil inlet of the plunger pump is provided with an oil suction filter, and the oil outlet is provided with a high pressure filter.

7. The four-wheel hydraulic steering system according to claim 1, characterized in that: The main oil return port HT of the first flow amplifier is connected to the second oil return filter through a pipeline, and the second oil return filter is connected to the hydraulic oil tank through a pipeline; the main oil return port HT of the second flow amplifier is connected to the third oil return filter through a pipeline, and the third oil return filter is connected back to the hydraulic oil tank through a pipeline.

8. An unmanned electric wheel mining dump truck, comprising: The front-wheel steering mechanism and the rear-wheel steering mechanism are characterized in that they include the four-wheel hydraulic steering system described in any one of claims 1 to 7, the front axle left steering cylinder and the front axle right steering cylinder are respectively connected to the front-wheel steering mechanism through pipelines, and the rear axle left steering cylinder and the rear axle right steering cylinder are respectively connected to the rear-wheel steering mechanism through pipelines.

9. The four-wheel hydraulic steering method of an unmanned electric wheel mining dump truck according to claim 8, characterized in that: include: The hydraulic oil is converted into high-pressure oil by the plunger pump and enters the steering valve group, and the steering valve group provides pressure oil for the first flow amplifier; The first electro-hydraulic steering gear is controlled to output pilot pressure oil to the first flow amplifier, the first flow amplifier drives the front axle steering cylinder to operate, and the front axle steering cylinder drives the front wheel steering mechanism of the vehicle to complete the steering.

10. The four-wheel hydraulic steering method of an unmanned electric wheel mining dump truck according to claim 9, characterized in that: The steering valve group provides pressure oil for the second electro-hydraulic steering gear, and the second electro-hydraulic steering gear is controlled to output pilot pressure oil to the second control flow amplifier, and the second control flow amplifier drives the rear axle steering cylinder to move, and the rear axle steering cylinder drives the rear wheel steering mechanism of the vehicle to complete the steering.

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