Vehicle rear axle electrically-controlled hydraulic steering system and vehicle

Abstract

The application provides a vehicle rear axle electric control hydraulic steering system and a vehicle, the vehicle rear axle electric control hydraulic steering system comprising an oil power module, a steering control module and an execution element, the oil power module being connected with the execution element through the steering control module, the oil power module comprising an oil tank and a steering pump, the steering control module comprising a power valve group, a steering valve group and a centering valve group, the oil tank being connected with the power valve group through the steering pump, the power valve group being connected with the steering valve group and the centering valve group, and the steering valve group and the centering valve group being connected with the execution element. The vehicle rear axle electric control hydraulic steering system can make the vehicle realize four functions of ordinary steering, crab steering, rear axle steering and all-wheel steering, is reliable in technology, high in safety, effectively solves the problems of too large steering diameter of the vehicle, poor maneuverability and inability to meet the use requirements of specific working conditions, can guarantee accurate control of the rear axle steering, reduce the minimum turning diameter of the vehicle and improve the passability of the vehicle in narrow road conditions.

Description

Technical Field

[0001] This application relates to the field of vehicle hydraulic system technology, and in particular to a vehicle rear axle electro-hydraulic steering system and vehicle. Background Technology

[0002] Vehicles operating in specific environments, such as fire trucks and airport snowplows, require small steering diameters and good maneuverability. However, existing vehicles typically use front-axle steering, which results in a large steering diameter, poor maneuverability, and low efficiency, failing to meet the demands of specific operational conditions.

[0003] Currently, the main structures of rear-wheel steering systems for commercial vehicles are rear-wheel mechanical steering, rear-wheel follow-up steering, electro-hydraulic steering, and electric wheel speed control steering. Among them, rear-wheel mechanical steering and follow-up steering systems suffer from problems such as inaccurate steering, tire wear, and instability at high speeds. Electric wheel speed control steering systems are complex in structure, technically difficult and costly, and have limited applicability. Electro-hydraulic steering systems are reliable and safe, accurately control the steering angle, and effectively solve the problems of insufficient passability, tire wear, and instability at high speeds, making them the main direction of development.

[0004] Based on this, a rear axle electro-hydraulic steering system is designed to address the problems of large steering diameter, poor maneuverability, low efficiency, and inability to meet the needs of specific working conditions in existing front axle steering systems. Summary of the Invention

[0005] In view of this, in order to overcome the shortcomings of the prior art, the present invention provides a rear axle electro-hydraulic steering system and vehicle, which effectively solves the problems of large steering diameter, poor maneuverability, low efficiency and inability to meet the needs of specific working conditions of the existing front axle steering system.

[0006] According to a first aspect of the present invention, a rear axle electro-hydraulic steering system for a vehicle is provided, wherein the rear axle electro-hydraulic steering system includes a hydraulic power module, a steering control module, and an actuator. The hydraulic power module is connected to the actuator via the steering control module. The hydraulic power module includes a tank and a steering pump. The steering control module includes a power valve group, a steering valve group, and a centering valve group. The tank is connected to the power valve group via the steering pump. The power valve group is connected to the steering valve group and the centering valve group. The steering valve group and the centering valve group are connected to the actuator.

[0007] Preferably, the hydraulic power module further includes a pressure filter and a first check valve, the steering pump is connected to the first check valve through the pressure filter, and the pressure filter is connected to the power valve assembly through the first check valve.

[0008] Preferably, the hydraulic power module further includes a return oil filter, and the return oil port of the power valve assembly is connected to the oil tank through the return oil filter.

[0009] Preferably, the hydraulic power module further includes a radiator, and the return port of the power valve assembly is connected to the return oil filter through the radiator.

[0010] Preferably, the power valve assembly includes a P2 port connected to the oil inlet line of the hydropneumatic suspension and a T4 port connected to the oil return line of the hydropneumatic suspension.

[0011] Preferably, the steering valve assembly includes a compensation valve, a performance balance valve, and a hydraulic lock. The compensation valve can overcome speed changes, the performance balance valve can prevent the actuator from being passively offset under external force, and the hydraulic lock can enable the steering chamber of the steering valve assembly to float or steer.

[0012] Preferably, the centering valve assembly includes a second check valve and a solenoid valve.

[0013] Preferably, the steering valve assembly is connected in parallel with the centering valve assembly.

[0014] Preferably, the steering control module further includes an accumulator, and the centering valve assembly is connected to the accumulator.

[0015] According to a second aspect of the invention, a vehicle is provided, the vehicle including the rear axle electro-hydraulic steering system as described above.

[0016] The rear axle electro-hydraulic steering system of the present invention, through the cooperation of the hydraulic power module, steering control module, and actuators, enables the vehicle to achieve four functions: normal steering, crab steering, rear axle steering, and all-wheel steering. It is technically reliable, highly safe, and effectively solves the problems of excessively large steering diameter, poor maneuverability, and inability to meet the needs of specific operating conditions. When the front wheels of the vehicle are steering, the steering wheel angle sensor transmits a signal to the controller. The controller, based on the vehicle speed and steering angle input, sends signals to the power valve group, steering valve group, and centering valve group to control the flow of the actuators, achieving synchronous steering of the rear axle. Simultaneously, the angle sensor feeds back the rear axle steering angle to the controller, forming a closed-loop control system. This ensures precise control of the rear axle steering, reduces the minimum turning diameter of the vehicle, and improves the vehicle's passability in narrow road conditions.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the structure of a vehicle rear axle electro-hydraulic steering system according to an embodiment of the present invention is shown.

[0020] Figure 2 A schematic diagram of the structure of a power valve assembly according to an embodiment of the present invention is shown;

[0021] Figure 3 A schematic diagram of the steering valve assembly according to an embodiment of the present invention is shown;

[0022] Figure 4 A schematic diagram of the centering valve assembly according to an embodiment of the present invention is shown;

[0023] Figure 5 A schematic diagram of the structure of an execution element according to an embodiment of the present invention is shown;

[0024] Figure 6 A schematic diagram of the steering pump according to an embodiment of the present invention is shown.

[0025] Attached reference numerals: 1-Fuel tank; 101-5ST; 2-Steering pump; 3-Pressure filter; 301-1DT; 4-First check valve; 5-Power valve assembly; 501-P0 port; 502-T0 port; 503-P1' port; 504-T2' port; 505-T3 port; 506-P2 port; 507-T4 port; 508-2DT; 509-3DT; 510-4ST; 6-Accumulator; 7-Centering valve assembly; 701-P1” port; 702-T2” port; 703-ACC port; 704-C1' port; 705-C2' port; 706-5DT; 707-3ST; 8-Actuator; 801-A” port; 802-B” port; 803-L” port; 804-C1” port; 805-C2” port; 9-Steering valve assembly; 901-P port; 902-T port; 903-A' port; 904-B' port; 905-L' port; 906-1ST; 907-2ST; 10-Radiator; 1001-6DT; 11-Return oil filter; 1101-4DT. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of the embodiments of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] According to a first aspect of the present invention, a vehicle rear axle electro-hydraulic steering system is provided, such as... Figures 1 to 6As shown, this rear axle electro-hydraulic steering system can be used in vehicles operating in specific environments, such as fire trucks and snowplows. This system enables these vehicles to have a smaller steering diameter and excellent maneuverability. The rear axle electro-hydraulic steering system includes a hydraulic power module, a steering control module, and an actuator 8.

[0031] In the following description, reference will be made to Figures 1 to 6 This section describes the detailed structure of the hydraulic power module, steering control module, and actuator 8 of the rear axle electro-hydraulic steering system of the vehicle.

[0032] like Figures 1 to 6 As shown, in this embodiment, the hydraulic power module is connected to the actuator 8 via the steering control module. The hydraulic power module can provide hydraulic oil and drive the steering control module to move. The steering control module can drive the rear axle of the vehicle to rotate at a precise angle. The actuator 8 can be, for example, a steering centering cylinder (such as...). Figure 5 (As shown). The control logic of the rear axle electro-hydraulic steering system of this vehicle is as follows: When the front wheels of the vehicle are turning, the steering wheel angle sensor (not shown) transmits a signal to the controller (not shown). The controller, based on the vehicle speed and steering angle input, sends signals to the hydraulic power module and the steering control module to control the flow rate of the steering cylinder, achieving synchronous steering of the rear axle. At the same time, the angle sensor feeds back the rear axle steering angle to the controller, forming a closed-loop control to ensure precise control of the rear axle steering. This precise control enables the vehicle to achieve four functions: normal steering, crab steering, rear axle steering, and all-wheel steering, greatly reducing the minimum turning diameter of the vehicle and improving its passability in narrow road conditions. Furthermore, the steering wheel angle sensor, controller, rear axle steering angle sensor, and the connection methods of these controllers are all existing technologies, which are known to those skilled in the art.

[0033] Specifically, the hydraulic power module may include an oil tank 1 and a steering pump 2, and the steering control module may include a power valve assembly 5, a steering valve assembly 9, and a centering valve assembly 7. The oil tank 1 is connected to the power valve assembly 5 via the steering pump 2. The steering pump 2 delivers hydraulic oil from the oil tank 1 to the power valve assembly 5. The steering pump 2 has the function of low energy consumption and simultaneously provides easy steering at low speeds and heavy and stable steering at high speeds (e.g., Figure 6 (As shown). The power valve group 5 is connected to the steering valve group 9 and the centering valve group 7. The power valve group 5 executes the input of hydraulic oil to meet the specific steering of the rear axle of the vehicle. The steering valve group 9 and the centering valve group 7 are connected to the actuator 8. After receiving the hydraulic oil, the steering valve group 9 and the centering valve group 7 drive the actuator 8 to perform the corresponding rotation action.

[0034] A specific control logic is as follows: when the front wheels of the vehicle are turning, the steering wheel angle sensor transmits a signal to the controller. The controller sends signals to the power valve group 5, the steering valve group 9 and the centering valve group 7 based on the vehicle speed and steering angle input, thereby controlling the flow of the actuator 8.

[0035] The vehicle's rear axle electro-hydraulic steering system, through the cooperation of the hydraulic power module, steering control module, and actuator 8, enables the vehicle to perform four functions: normal steering, crab steering, rear axle steering, and all-wheel steering. The system is technically reliable, highly safe, and effectively solves the problems of excessively large steering diameters, poor maneuverability, and inability to meet specific operating conditions. When the front wheels are steering, the steering wheel angle sensor transmits a signal to the controller. Based on the vehicle speed and steering angle input, the controller sends signals to the power valve group 5, steering valve group 9, and centering valve group 7 to control the flow rate of actuator 8, achieving synchronous steering of the rear axle. Simultaneously, the angle sensor feeds back the rear axle steering angle to the controller, forming a closed-loop control system. This ensures precise rear axle steering control, reduces the vehicle's minimum turning diameter, and improves the vehicle's passability in narrow road conditions.

[0036] Preferably, such as Figure 1 As shown in the embodiment, the hydraulic power module may further include a pressure filter 3 and a first check valve 4. The steering pump 2 is connected to the first check valve 4 via the pressure filter 3, and the pressure filter 3 is connected to the power valve assembly 5 via the first check valve 4. The pressure filter 3 ensures the cleanliness of the hydraulic oil and improves the reliability of the steering solenoid valve assembly. The first check valve 4 prevents the hydraulic oil from flowing backward, protects the steering pump 2 from reverse impact, and improves the pump's service life.

[0037] Preferably, such as Figure 1 As shown, in this embodiment, the hydraulic power module may further include a return oil filter 11, and the return oil port of the power valve assembly 5 is connected to the oil tank 1 through the return oil filter 11.

[0038] Preferably, such as Figure 1 As shown, in this embodiment, the hydraulic power module may further include a radiator 10, and the return port of the power valve assembly 5 is connected to the return oil filter 11 through the radiator 10. The radiator 10 may be, for example, an air-cooled radiator, which can maintain the heat balance of the electro-hydraulic system and ensure the normal operation of the steering system.

[0039] Preferably, such as Figure 1 and Figure 2 As shown, in this embodiment, the power valve assembly 5 may include a P2 port 506 connected to the oil inlet line of the air suspension and a T4 port 507 connected to the oil return line of the air suspension. Thus, the power valve assembly 5 can simultaneously provide power to the air suspension.

[0040] Preferably, in this embodiment, the steering valve assembly 9 may include a compensation valve, a performance balance valve, and a hydraulic lock. The compensation valve can overcome speed variations, which is beneficial for overcoming speed changes caused by load instability, making the cylinder operation smoother and more stable. The performance balance valve can prevent the actuator 8 from being passively offset under external force, improving safety. The hydraulic lock enables the steering chamber of the steering valve assembly 9 to float or steer, reducing the logic control of the electronic control and making the system simpler and more reliable.

[0041] Preferably, in an embodiment, the centering valve assembly 7 may include a second check valve and a solenoid valve. The second check valve may be, for example, a check valve with a cone valve structure, and the solenoid valve may be a leak-free solenoid valve. Both of these can be connected to the accumulator 6 described below, which can maintain the pressure in the accumulator 6 for a longer period of time, greatly reducing the number of times the steering pump 2 starts and stops, and extending the service life of the steering pump 2.

[0042] Preferably, such as Figure 1 As shown, in this embodiment, the steering valve assembly 9 and the centering valve assembly 7 are connected in parallel. In the entire hydraulic system, the centering valve assembly 7 and the steering valve assembly 9 are designed separately, simplifying the overall design of the valve assemblies, facilitating troubleshooting, and also benefiting pipeline layout and equipment installation.

[0043] Preferably, such as Figure 1 As shown, in this embodiment, the steering control module also includes an accumulator 6, and the centering valve group 7 is connected to the accumulator 6. The accumulator 6 can absorb the flow pulsations output by the steering pump 2, reducing pressure fluctuations and noise in the system, making the system operate more smoothly. When the steering pump 2 malfunctions, the accumulator 6 acts as an emergency power source, providing power to the actuator 8 under the command of the control unit, ensuring that the actuator 8 is in a centered state. In other words, when the rear axle electro-hydraulic steering system malfunctions, the controller can transmit a signal to the centering valve group 7 to control the actuator 8 to achieve centering. During this process, the accumulator 6 can provide continuous pressure maintenance, causing the rear axle steering to lock and ensuring the safety of vehicle operation.

[0044] See Figures 1 to 5 The specific connection relationships of the various components in the rear axle electro-hydraulic steering system of the vehicle are as follows: the P0 port 501 of the power valve group 5 is connected to the oil pipe of the first one-way valve 4; the T0 port 502 of the power valve group 5 is connected to the return oil pipe of the oil tank 1; the P1' port 503 of the power valve group 5 is connected to the P port 901 of the steering valve group 9 and the P1” port 701 of the centering valve group 7 through a three-way valve; the T2' port 504 of the power valve group 5 is connected to the T2” port 702 of the centering valve group 7; the T3 port 505 of the power valve group 5 is connected to the T port 902 of the steering valve group 9; the P2 port 506 and the T4 port 507 of the power valve group 5 are respectively connected to the oil inlet pipe of the air suspension and the oil inlet pipe of the air suspension.

[0045] The P port 901 of the steering valve assembly 9 is connected to the P1' port 503 of the power valve assembly 5, the T port 902 of the steering valve assembly 9 is connected to the T3 port 505 of the power valve assembly 5, the A' port 903 of the steering valve assembly 9 is connected to the A” port 801 of the actuator 8, the B' port 904 of the steering valve assembly 9 is connected to the B” port 802 of the actuator 8, and the L' port 905 of the steering valve assembly 9 is connected to the L” port 803 of the actuator 8.

[0046] The ACC port 703 of the centering valve group 7 can be connected to the accumulator 6 via a ball valve. The P1” port 701 of the centering valve group 7 is connected to the P1' port 503 of the power valve group 5. The T2” port 702 of the centering valve group 7 is connected to the T2' port 504 of the power valve group 5. The C1' port 704 of the centering valve group 7 is connected to the C1” port 804 of the actuator 8. The C2’ port 705 of the centering valve group 7 is connected to the C2” port 805 of the actuator 8.

[0047] The T0 port 502 of the power valve assembly 5 is connected to the radiator 10, and the radiator 10 is connected to the return oil filter 11.

[0048] See Figures 1 to 5 The specific connection relationships of the various components in the rear axle electro-hydraulic steering system of this vehicle are as follows:

[0049] The control logic method of the rear axle electro-hydraulic steering system of this vehicle is as follows: When power valve group 5's 3DT509, centering valve group 7's 5DT706, and steering valve group 9's 1ST906 are all active simultaneously, the rear axle performs a left steering action. When power valve group 5's 3DT509, centering valve group 7's 5DT706, and steering valve group 9's 2ST907 are all active simultaneously, the rear axle performs a right steering action. When only power valve group 5's 3DT509 is active, for example, the actuator 8 of the steering centering cylinder is in the centering state. When power valve group 5's 3DT509 and centering valve group 7's 3ST707 are active simultaneously, the accumulator 6 performs a charging action. When only power valve group 5's 4ST510 is active, a pump source fault alarm is triggered. When radiator 10's 6DT1001 and hydraulic oil tank 1's 5ST101 are active simultaneously, radiator 10 starts working. When only hydraulic oil tank 1's 5ST101 is active, radiator 10 stops working. When pressure filter 3's 1DT301 and power valve assembly 5's 3DT509 are both active, pressure filter 3 will issue an alarm. When power valve assembly 5's 3DT509 and return oil filter 11's 4DT1101 are both active, return oil filter 11 will issue an alarm. When only power valve assembly 5's 2DT508 is active, the hydropneumatic suspension will begin to operate. Furthermore, DT and ST can be understood as common electrically operated regulating valves in valve assemblies; their operating principles are based on existing, commonly used technology and will not be elaborated upon here.

[0050] The vehicle's rear axle electro-hydraulic steering system, through the coordination of a hydraulic power module, a steering control module, and actuators, enables the vehicle to perform four functions: normal steering, crab steering, rear axle steering, and all-wheel steering. The system is technically reliable, highly safe, and effectively solves the problems of excessively large steering diameters, poor maneuverability, and inability to meet specific operating conditions. When the front wheels are steering, the steering wheel angle sensor transmits a signal to the controller. Based on the vehicle speed and steering angle input, the controller sends signals to the power valve group, steering valve group, and centering valve group to control the flow of the actuators, achieving synchronous steering of the rear axle. Simultaneously, the angle sensor feeds back the rear axle steering angle to the controller, forming a closed-loop control system. This ensures precise rear axle steering control, reduces the vehicle's minimum turning diameter, and improves the vehicle's passability in narrow road conditions.

[0051] Furthermore, according to a second aspect of the present invention, a vehicle is provided, the vehicle including the rear axle electro-hydraulic steering system as described above. During operation, the vehicle, through the rear axle electro-hydraulic steering system, can achieve four functions: normal steering, crab steering, rear axle steering, and all-wheel steering, greatly reducing the minimum turning diameter of the vehicle and improving its passability in narrow road conditions.

[0052] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. An electrically controlled hydraulic steering system for a vehicle rear axle, characterized by, The vehicle rear axle electrically-controlled hydraulic steering system comprises an oil power module, a steering control module and an execution element, the oil power module is connected with the execution element through the steering control module, the oil power module comprises an oil tank and a steering pump, the steering control module comprises a power valve group, a steering valve group and a centering valve group, the oil tank is connected with the power valve group through the steering pump, the power valve group is connected with the steering valve group and the centering valve group, and the steering valve group and the centering valve group are connected with the execution element. The oil power module further comprises a pressure filter and a first one-way valve, the steering pump is connected with the first one-way valve through the pressure filter, and the pressure filter is connected with the power valve group through the first one-way valve. The P0 port of the power valve group is connected with an oil pipe of the first one-way valve, the T0 port of the power valve group is connected with an oil return pipe of the oil tank, the P1' port of the power valve group is connected with the P port of the steering valve group and the P1" port of the centering valve group through a three-way valve, the T2' port of the power valve group is connected with the T2" port of the centering valve group, the T3 port of the power valve group is connected with the T port of the steering valve group, and the P2 port of the power valve group and the T4 port of the power valve group are respectively connected with an oil gas suspension oil inlet pipeline and an oil gas suspension oil inlet pipeline. The P port of the steering valve group is connected with the P1' port of the power valve group, the T port of the steering valve group is connected with the T3 port of the power valve group, the A' port of the steering valve group is connected with the A" port of the execution element, the B' port of the steering valve group is connected with the B" port of the execution element, and the L' port of the steering valve group is connected with the L" port of the execution element. The steering control module further comprises an accumulator, and the centering valve group is connected with the accumulator. The ACC port of the centering valve group can be connected with the accumulator through a ball valve, the P1" port of the centering valve group is connected with the P1' port of the power valve group, the T2" port of the centering valve group is connected with the T2' port of the power valve group, the C1' port of the centering valve group is connected with the C1" port of the execution element, and the C2' port of the centering valve group is connected with the C2" port of the execution element.

2. The electronically controlled hydraulic vehicle rear axle steering system of claim 1, wherein, The oil power module further comprises an oil return filter, and an oil return port of the power valve group is connected with the oil tank through the oil return filter.

3. The electronically controlled hydraulic vehicle rear axle steering system of claim 2, wherein, The oil power module further comprises a radiator, and an oil return port of the power valve group is connected with the oil return filter through the radiator.

4. The electronically controlled hydraulic vehicle rear axle steering system of claim 1, wherein, The power valve group comprises the P2 port connected with the oil gas suspension oil inlet pipeline and the T4 port connected with the oil gas suspension oil return pipeline.

5. The electronically controlled hydraulic vehicle rear axle steering system of claim 1, wherein, The steering valve group comprises a compensation valve, a performance balance valve and a hydraulic lock, the compensation valve can overcome speed changes, the performance balance valve can avoid passive deviation of the execution element under external force, and the hydraulic lock can make a steering cavity of the steering valve group float or steer.

6. The electronically controlled hydraulic vehicle rear axle steering system of claim 1, wherein, The centering valve group comprises a second one-way valve and a solenoid valve.

7. The electronically controlled hydraulic vehicle rear axle steering system of claim 1, wherein, The steering valve group is connected with the centering valve group in parallel.

8. A vehicle characterized by comprising: The vehicle comprises the vehicle rear axle electrically-controlled hydraulic steering system in any one of claims 1 to 7.

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