Four-wheel steering electro-hydraulic control system and vehicle

Abstract

The utility model relates to the field of vehicle four-wheel steering, and specifically relates to a four-wheel steering electro-hydraulic control system and vehicle, include: front wheel steering module, including front steering oil cylinder for driving front wheel and control the steering action of front wheel, rear wheel steering module, including rear steering oil cylinder for driving rear wheel and control the steering action of rear wheel. It can not only realize front wheel steering, but also can realize rear wheel steering, improve vehicle control flexibility, improve driving experience and safety.

Description

Technical Field

[0001] This utility model relates to the field of four-wheel steering in vehicles, specifically to a four-wheel steering electro-hydraulic control system and a vehicle. Background Technology

[0002] With the continuous development of the automotive industry and the constant advancement of intelligent technologies, modern vehicles are becoming increasingly diverse in design and function. As a core component of vehicle control, the steering system's performance directly affects driving agility and safety.

[0003] In traditional vehicle design, most vehicles employ a front-wheel steering system, where the steering wheel controls the left and right turns of the front wheels, while the rear wheels remain fixed or passively follow the steering angle of the front wheels. This design meets basic needs in ordinary driving scenarios, but in complex road conditions, such as parking in tight spaces, high-speed cornering, or emergency obstacle avoidance, the vehicle's handling agility is limited. The main limitation of the front-wheel steering system is that the rear wheels cannot actively participate in steering, resulting in a larger turning radius or less rapid vehicle attitude adjustment, thus affecting the driving experience and safety. Utility Model Content

[0004] The purpose of this invention is to provide a four-wheel steering electro-hydraulic control system device, which can not only realize front wheel steering, but also rear wheel steering, thereby improving vehicle handling flexibility, driving experience and safety.

[0005] Another objective of this invention is to provide a vehicle that can not only achieve front-wheel steering but also rear-wheel steering, thereby improving vehicle handling flexibility, driving experience, and safety.

[0006] The technical solution of this utility model is implemented as follows: A four-wheel steering electro-hydraulic control system, comprising: A front wheel steering module, including a front steering cylinder, for driving the front wheels and controlling the steering action of the front wheels; The rear wheel steering module includes a rear steering cylinder for driving the rear wheels and controlling their steering action.

[0007] Furthermore, the front wheel steering module includes: First fuel tank; A first gear pump, the inlet of which is connected to the outlet of the first oil tank, is used to draw hydraulic oil from the first oil tank. A front steering cylinder, wherein the two ports of the front steering cylinder are A end and B end, respectively, are used to control the steering of the front wheels; A first reversing valve is disposed between the front steering cylinder and the first gear pump. The first reversing valve has a P port, a T port, an L port and an R port, which are used to control the flow direction of hydraulic oil. The output port of the first gear pump is connected to the P port through a first pipeline, the R port is connected to the A end of the front steering cylinder through a second pipeline, and the L port is connected to the B end of the front steering cylinder through a third pipeline. The steering mechanism is used to control the connection between port P and any one of ports R, T, or L. The first return line has an output end connected to the oil inlet of the first oil tank. The input end of the first return line branches into a first return pipe and a second return pipe. The inlet end of the first return pipe is connected to the second line, and the inlet end of the second return pipe is connected to the third line.

[0008] Furthermore, the front wheel steering module also includes an overflow valve assembly for adjusting and balancing system pipeline pressure, the overflow valve assembly comprising: A first overflow valve is provided between the first pipeline and the first return pipeline, and the first overflow valve is provided on the first overflow valve. A second overflow valve is provided on the first return pipe; The third overflow valve is installed on the second return pipe.

[0009] Furthermore, the rear wheel steering module includes: Second fuel tank; The second gear pump has its inlet connected to the outlet of the second oil tank and is used to draw hydraulic oil from the second oil tank. A rear steering cylinder, wherein the two ports of the rear steering cylinder are end E and end F, respectively; The reversing valve assembly connects the output port of the second gear pump to the two ports of the rear steering cylinder through the reversing valve assembly, and is used to control the hydraulic oil path so that the hydraulic oil enters from the E end or the F end of the rear steering cylinder; The second return line is used to return the hydraulic oil flowing into the rear steering cylinder to the second oil tank.

[0010] Furthermore, the directional valve assembly includes a second directional valve, a third directional valve, and a fourth directional valve; The rear wheel steering module also includes: The priority valve is connected to the input port of the second gear pump via a fourth pipeline. The priority valve is used to distribute the hydraulic oil flow. The output port of the second gear pump is also connected to the input port of the second directional valve via a fifth pipeline. The second directional valve is used to control the hydraulic oil flow direction. The output end of the priority valve is connected to the input end of the fourth directional valve via a sixth pipeline and to the oil inlet of the second oil tank via a seventh pipeline. The output ports of the first solenoid valve and the second directional valve are respectively connected to the first solenoid valve, the third directional valve and the second return pipeline. The output port of the second directional valve is connected to the second return pipeline for overflow. The first solenoid valve is used to control the hydraulic oil signal and transmit it to the third directional valve. The output port of the third directional valve is also connected to the solenoid valve assembly through an eighth pipeline. The solenoid valve assembly is used to receive electrical signals and control the action of the fourth directional valve to allow hydraulic oil to enter from the E or F end of the rear steering cylinder. The third directional valve is also connected to the fourth relief valve. When the valve core of the third directional valve is in the right chamber, the hydraulic oil flows back to the second oil tank through the fourth relief valve.

[0011] Furthermore, the output end of the second return pipeline is connected to the oil inlet of the second oil tank, and the input end of the second return pipeline branches into a third return pipeline and a fourth return pipeline. The inlet end of the third return pipeline is connected to the E end of the rear steering cylinder, and a fifth overflow valve is installed on the third return pipeline. The inlet end of the fourth return pipeline is connected to the F end of the rear steering cylinder, and a sixth overflow valve is installed on the fourth return pipeline.

[0012] Furthermore, the solenoid valve assembly includes a second solenoid valve, a third solenoid valve, a fourth solenoid valve, and a fifth solenoid valve. The second solenoid valve, the third solenoid valve, the fourth solenoid valve, and the fifth solenoid valve are used to form a pilot control structure for a directional valve to precisely control the action of the fourth directional valve. The two ports of the fourth reversing valve are C and D, respectively. The rear-wheel steering module can achieve multiple rear-wheel steering modes through different combinations of the activation states of the second, third, fourth, and fifth solenoid valves, including but not limited to: When the second and third solenoid valves are turned on and the fourth and fifth solenoid valves are not turned on, the hydraulic oil flows directly back to the second oil tank. The fourth directional valve receives the hydraulic oil signal and does not turn on. At this time, the rear steering cylinder does not move. When the third and fourth solenoid valves are turned on and the second and fifth solenoid valves are turned off, the hydraulic oil is transmitted to the C end of the fourth directional valve through the fourth solenoid valve. The fourth directional valve receives the hydraulic oil signal and turns on, and the hydraulic oil flows to the third directional valve. Then it flows from the third directional valve to the E end of the rear steering cylinder and controls the rear steering cylinder to move. The hydraulic oil then flows out from the F end of the rear steering cylinder and flows back to the second oil tank through the sixth relief valve. When the second and fifth solenoid valves are turned on, and the third and fourth solenoid valves are turned off, the hydraulic oil is transmitted to the D end of the fourth directional valve through the fourth solenoid valve. The fourth directional valve receives the hydraulic oil signal and turns on, and the hydraulic oil flows to the third directional valve. Then, it flows from the third directional valve to the F end of the rear steering cylinder and controls the rear steering cylinder to move. The hydraulic oil then flows out from the E end of the rear steering cylinder and flows back to the second oil tank through the fifth relief valve.

[0013] Furthermore, a second overflow pipe is provided between the output port of the third reversing valve and the input port of the second reversing valve; When the pressure value at the output port of the third directional valve exceeds the set value, the hydraulic oil is diverted through the second overflow pipe to the second directional valve, causing the second directional valve to switch the valve core and return the excess hydraulic oil to the second oil tank.

[0014] Furthermore, it also includes a controller for sending electrical signals to control the valve core position of the solenoid valve assembly to control the action of the solenoid valve assembly, thereby achieving precise control of the rear wheel steering.

[0015] A vehicle includes front wheels and rear wheels, and also includes the aforementioned four-wheel steering electro-hydraulic control system, wherein the front steering cylinder is connected to the front wheel via a linkage mechanism for driving the front wheel and controlling the steering action of the front wheel; The rear steering cylinder is connected to the rear wheel via a linkage mechanism and is used to drive the rear wheel and control its steering action.

[0016] Compared with the prior art, the beneficial effects of this utility model are: This solution proposes a brand-new four-wheel steering electro-hydraulic control system, which significantly improves the vehicle's handling performance. Even in complex road conditions, such as parking in narrow spaces, high-speed cornering, or emergency obstacle avoidance, the vehicle's handling agility will not be limited. Through hydraulic control, the front and rear wheels can be steered independently, allowing for rapid adjustments to the vehicle's posture even when the turning radius is large, thereby improving the driving experience and safety. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the four-wheel steering electro-hydraulic control system of this utility model; Figure 2 This is a schematic diagram of the structure within the first dashed box of this utility model; Figure 3 This is a schematic diagram of the structure within the second dashed box of this utility model.

[0019] In the picture: 1-First oil tank; 2-First gear pump; 3-Front steering cylinder; 4-First directional valve; 5-Steering gear; 6-First return line; 7-First line; 8-Second line; 9-Third line; 10-First relief valve; 11-Second relief valve; 12-Third relief valve; 13-Second oil tank; 14-Second gear pump; 15-Rear steering cylinder; 16-Second directional valve; 17-Third directional valve; 18-Fourth directional valve; 19-Second return line; 20-Priority valve; 21-Fourth relief valve; 22-Fifth relief valve; 23-Sixth relief valve; 24-First solenoid valve; 25-Second solenoid valve; 26-Third solenoid valve; 27-Fourth solenoid valve; 28-Fifth solenoid valve; 29-Fourth pipe; 30-Fifth pipe; 31-Sixth pipe; 32-Seventh pipe; 33-Eighth pipe; 34-Ninth pipe; 35-Tenth pipe; 36-Eleventh pipe; 37 - First dashed box; 38 - Second dashed box. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this utility model, it should be noted that the terms "center," "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 utility model is in use. They are only for the convenience of describing this utility model 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 utility model. 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.

[0024] Furthermore, terms such as "horizontal," "vertical," and "sag" 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 relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 utility model based on the specific circumstances.

[0026] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] Example 1 Reference Figures 1-3 This embodiment provides a four-wheel steering electro-hydraulic control system, including: The front wheel steering module includes a front steering cylinder 3, which is used to drive the front wheels and control the steering action of the front wheels; The rear wheel steering module includes a rear steering cylinder 15 for driving the rear wheels and controlling the steering action of the rear wheels.

[0028] The rear wheel steering module uses a combination of solenoid valves and directional valves to achieve precise control of the rear wheel steering angle.

[0029] The front wheel steering module includes: First fuel tank 1; The first gear pump 2 has its input port connected to the oil outlet of the first oil tank 1, and is used to draw hydraulic oil from the first oil tank 1. The front steering cylinder 3 has two ports, A and B, which are used to control the steering of the front wheels. The first reversing valve 4 is located between the front steering cylinder 3 and the first gear pump 2. The first reversing valve 4 has a P port, a T port, an L port and an R port, which are used to control the flow direction of hydraulic oil. The output port of the first gear pump 2 is connected to the P port through the first pipeline 7, the R port is connected to the A end of the front steering cylinder 3 through the second pipeline 8, and the L port is connected to the B end of the front steering cylinder 3 through the third pipeline 9. Steering device 5 is used to control the connection between port P and any one of ports R, T, and L; The first return line 6 has its output end connected to the oil inlet of the first oil tank 1. The input end of the first return line 6 branches into a first return pipe and a second return pipe. The inlet end of the first return pipe is connected to the second line 8, and the inlet end of the second return pipe is connected to the third line 9.

[0030] The front wheel steering module also includes an overflow valve assembly for regulating and balancing system line pressures. The overflow valve assembly includes: The first overflow valve 10 is provided between the first pipeline 7 and the first return pipeline 6, and the first overflow valve 10 is provided on the first overflow pipe; The second overflow valve 11 is installed on the first return pipe; The third overflow valve 12 is installed on the second return pipe.

[0031] The first gear pump 2 draws hydraulic oil from the first oil tank 1, which is then diverted to port P via point P1. Port R is connected to end A of the front steering cylinder 3, and port L is connected to end B of the front steering cylinder 3. The steering gear 5 controls the first directional valve 4 to connect port P to any one of port R, port T, or port L, as follows: When port P is connected to port T, the hydraulic oil flows directly back to the first oil tank 1. When the pressure between the first gear pump 2 and port P exceeds the pressure value of the first relief valve 10, the excess hydraulic oil flows out through the first relief valve 10. When port P is connected to port R, hydraulic oil flows out through port R to end A of the front steering cylinder 3 and controls the front steering cylinder 3 to move. The hydraulic oil at end B of the front steering cylinder 3 flows back to the first oil tank 1 after passing through the third relief valve 12. When port P is connected to port L, hydraulic oil flows out through port L to end B of the front steering cylinder 3 and controls the front steering cylinder 3 to move. The hydraulic oil at end A of the front steering cylinder 3 flows back to the first oil tank 1 after passing through the second relief valve 11.

[0032] For ease of description, Figure 1 The front wheel steering module section establishes a first dashed box 37. This first dashed box 37 intersects with the first pipe 7, the first output pipe, the second pipe 8, and the third pipe 9, forming four corner points. These four intersection points are P1, T1, R1, and L1, respectively. Figure 1 and Figure 2 As shown.

[0033] The principle of front wheel steering is: The first gear pump 2 draws hydraulic oil from the first oil tank 1, and the oil is diverted to the first directional valve 4 through point P1. The position is controlled by the steering gear 5. When the P port and T port of the first directional valve 4 are connected, the hydraulic oil flows back to the first oil tank 1 directly through point T1. When the pressure at point P1 exceeds the pressure value of the first relief valve 10, the excess hydraulic oil will flow out through the first relief valve 10 to ensure the pressure at the first directional valve 4 is stable.

[0034] When the P port of the first directional valve 4 is connected to the R port, hydraulic oil flows out through point R1 and controls the front steering cylinder 3 to actuate, driving the front wheels to turn in one direction. At this time, the pressure at point L1 increases, and the hydraulic oil at end B of the front steering cylinder 3 flows back to the first oil tank 1 through the third relief valve 12 and point T1. When the P port of the first directional valve 4 is connected to the L port, hydraulic oil flows out through point L1 and enters the front steering cylinder 3 to actuate, driving the front wheels to turn in another direction. At this time, the pressure at point R1 increases, and the hydraulic oil at end A of the front steering cylinder 3 flows back to the first oil tank 1 through the second relief valve 11 and point T1.

[0035] The rear-wheel steering module includes: Second fuel tank 13; The second gear pump 14 has its inlet connected to the outlet of the second oil tank 13 and is used to draw hydraulic oil from the second oil tank 13. The rear steering cylinder 15 has two ports, E and F, respectively. The output port of the second gear pump 14 is connected to the two ports of the rear steering cylinder 15 through the reversing valve assembly, which is used to control the hydraulic oil path so that the hydraulic oil enters from the E end or the F end of the rear steering cylinder 15. The second return line 19 is used to return the hydraulic oil flowing into the rear steering cylinder 15 to the second oil tank 13.

[0036] The directional valve assembly includes a second directional valve 16, a third directional valve 17, and a fourth directional valve 18; The rear-wheel steering module also includes: Priority valve 20 is connected to the output port of the second gear pump 14 via the fourth pipeline 29. Priority valve 20 is used to distribute hydraulic oil flow. The output port of the second gear pump 14 is also connected to the input port of the second directional valve 16 via the fifth pipeline 30. The second directional valve 16 is used to control the direction of hydraulic oil flow. The fifth pipeline 30 is connected to the fourth pipeline 29. The output end of the fourth pipeline 29 branches into two ports, one of which is connected to the input port of priority valve 20 and the other port is connected to the fifth pipeline 30. The output end of priority valve 20 is connected to the input end of the fourth directional valve 18 via the sixth pipeline 31 and to the inlet of the second oil tank 13 via the seventh pipeline 32. The output ports of the first solenoid valve 24 and the second directional valve 16 are respectively connected to the first solenoid valve 24, the third directional valve 17 and the second return line 19. The output port of the second directional valve 16 is connected to the second return line 19 for overflow. The first solenoid valve 24 is used to control the hydraulic oil signal and transmit it to the third directional valve 17. The three output ports of the solenoid valve assembly and the third directional valve 17 are respectively connected to the solenoid valve assembly through the eighth pipe 33, to the E end of the rear steering cylinder 15 through the ninth pipe 34, and to the F end of the rear steering cylinder 15 through the tenth pipe 35. The solenoid valve assembly is used to receive electrical signals and control the action of the fourth directional valve 18 to allow hydraulic oil to enter from the E end or F end of the rear steering cylinder 15. The third directional valve 17 is also connected to the fourth relief valve 21. The third directional valve 17 has a left chamber and a right chamber. When the valve core of the third directional valve 17 is in the right chamber, the hydraulic oil flows back to the second oil tank 13 through the fourth relief valve 21.

[0037] In this embodiment, the output end of the second return pipe 19 is connected to the oil inlet of the second oil tank 13. The input end of the second return pipe 19 branches into a third return pipe and a fourth return pipe. The inlet end of the third return pipe is connected to the E end of the rear steering cylinder 15 through the ninth pipe 34. A fifth overflow valve 22 is provided on the third return pipe. The inlet end of the fourth return pipe is connected to the F end of the rear steering cylinder 15 through the tenth pipe 35. A sixth overflow valve 23 is provided on the fourth return pipe.

[0038] The solenoid valve assembly includes a second solenoid valve 25, a third solenoid valve 26, a fourth solenoid valve 27, and a fifth solenoid valve 28. The second solenoid valve 25, the third solenoid valve 26, the fourth solenoid valve 27, and the fifth solenoid valve 28 are used to form a pilot control structure for a directional valve to precisely control the action of the fourth directional valve 18. The two ports of the fourth directional valve 18 are C and D, respectively; The rear-wheel steering module can achieve various rear-wheel steering modes through different combinations of the activation states of the second solenoid valve 25, the third solenoid valve 26, the fourth solenoid valve 27, and the fifth solenoid valve 28, including but not limited to: When the second solenoid valve 25 and the third solenoid valve 26 are turned on, and the fourth solenoid valve 27 and the fifth solenoid valve 28 are not turned on, the hydraulic oil flows directly back to the second return pipeline 19 through the eleventh pipeline 36, and then back to the second oil tank 13. The fourth directional valve 18 receives the hydraulic oil signal and does not turn on. At this time, the rear steering cylinder 15 does not move. When the third solenoid valve 26 and the fourth solenoid valve 27 are turned on, and the second solenoid valve 25 and the fifth solenoid valve 28 are not turned on, the hydraulic oil is transmitted to the C end of the fourth directional valve 18 through the fourth solenoid valve 27. The fourth directional valve 18 receives the hydraulic oil signal and turns on, and the hydraulic oil flows to the third directional valve 17. Then it flows from the third directional valve 17 to the E end of the rear steering cylinder 15 and controls the rear steering cylinder 15 to move. The hydraulic oil then flows out from the F end of the rear steering cylinder 15 and flows back to the second oil tank 13 through the sixth relief valve 23. When the second solenoid valve 25 and the fifth solenoid valve 28 are turned on, and the third solenoid valve 26 and the fourth solenoid valve 27 are not turned on, the hydraulic oil is transmitted to the D end of the fourth directional valve 18 through the fourth solenoid valve 27. The fourth directional valve 18 receives the hydraulic oil signal and turns on, and the hydraulic oil flows to the third directional valve 17. Then, it flows from the third directional valve 17 to the F end of the rear steering cylinder 15 and controls the rear steering cylinder 15 to move. The hydraulic oil then flows out from the E end of the rear steering cylinder 15 and flows back to the second oil tank 13 through the fifth relief valve 22.

[0039] A second overflow pipe is provided between the left output port of the third directional valve 17 and the input port of the second directional valve 16. When the pressure value at the left output port of the third directional valve 17 exceeds the set value, the hydraulic oil is diverted through the second overflow pipe to the second directional valve 16, causing the second directional valve 16 to switch its valve core and return the excess hydraulic oil to the second oil tank 13. A third overflow pipe is provided at one output port on the right end of the third directional valve 17. The other end of the third overflow pipe is connected to the second return pipe 19. A fourth overflow valve 21 is provided on the third overflow pipe. When the pressure value at the right end of the third directional valve 17 exceeds the set value, the hydraulic oil flows through the third overflow pipe and the fourth overflow valve 21, and then through the second return pipe 19 back to the second oil tank 13.

[0040] In summary, the second directional valve 16 is used to ensure that the first solenoid valve 24 receives a constant hydraulic flow; the third directional valve 17 is used to open or close the hydraulic oil path according to the solenoid valve signal; and the fourth directional valve 18 is used to control the action of the rear steering cylinder 15 according to the hydraulic oil signal.

[0041] The electro-hydraulic control system also includes a controller for sending electrical signals to control the valve core position of the solenoid valve assembly to control the movement of the solenoid valve assembly, thereby achieving precise control of the rear wheel steering.

[0042] For ease of understanding, Figure 1 The rear wheel steering module establishes a second dashed box 38. This second dashed box 38, along with the fourth pipe 29, eleventh pipe 36, eighth pipe 33, ninth pipe 34, tenth pipe 35, second return pipe 19, and seventh pipe 32, forms seven intersection points. These seven intersection points are P2, TE, PE, LC, LR, T2, and EF, respectively. Figure 2 and Figure 3 As shown.

[0043] The principle of rear wheel steering is: Hydraulic oil is drawn from the second oil tank 13 by the second gear pump 14 and split at point P2. One branch goes to the priority valve 20, where, to ensure system safety, the priority valve 20 prioritizes supplying oil to the fourth directional valve 18. The other branch of hydraulic oil from the second gear pump 14 is split through the fifth pipeline 30 to the second directional valve 16. The function of the second directional valve 16 is to ensure a constant hydraulic flow rate received by the first solenoid valve 24. The second directional valve 16 provides a constant flow rate to the first solenoid valve 24 and a flow rate to the third directional valve 17. After the pressure value at the output port of the third directional valve 17 exceeds the set value, the hydraulic oil is diverted through the second overflow pipe to the second directional valve 16, causing the second directional valve 16 to switch the valve core, and the excess hydraulic oil flows back to the second oil tank 13 through point T2; after the first solenoid valve 24 passes, the steering cylinder 15 sends an electrical signal to conduct hydraulic oil to control the third directional valve 17 to switch the valve core position, so that the hydraulic oil of the third directional valve 17 is open or closed; after the third directional valve 17 is open, the oil of the second directional valve 16 flows through the third directional valve 17 to point PE and then flows into the solenoid valve assembly; When the second solenoid valve 25 and the third solenoid valve 26 are turned on, and the fourth solenoid valve 27 and the fifth solenoid valve 28 are not turned on, the hydraulic oil signal flows back to the second oil tank 13 through the TE point and the T2 point. The fourth directional valve 18 receives the hydraulic oil signal and does not turn on. At this time, the rear steering cylinder 15 does not move. When the third solenoid valve 26 and the fourth solenoid valve 27 are turned on, and the second solenoid valve 25 and the fifth solenoid valve 28 are not turned on, the hydraulic oil is transmitted to the C end of the fourth directional valve 18 through the fourth solenoid valve 27. The fourth directional valve 18 receives the hydraulic oil signal and turns on, and the hydraulic oil flows to the third directional valve 17. Through the third directional valve 17, the hydraulic oil flows to the LC point and the E end of the rear steering cylinder 15, thereby controlling the rear steering cylinder 15 to move and drive the rear wheels to turn in one direction. When the hydraulic oil pressure at the LR point increases, the hydraulic oil flows out from the F end of the rear steering cylinder 15 and flows back to the second oil tank 13 through the sixth relief valve 23 and the T2 point. When the second solenoid valve 25 and the fifth solenoid valve 28 are turned on, and the third solenoid valve 26 and the fourth solenoid valve 27 are turned off, the hydraulic oil is transmitted to the D end of the fourth directional valve 18 through the fourth solenoid valve 27. The fourth directional valve 18 receives the hydraulic oil signal and turns on, and the hydraulic oil flows to the third directional valve 17. From the third directional valve 17, the hydraulic oil flows to the LR point and the F end of the rear steering cylinder 15, thereby controlling the rear steering cylinder 15 to move and drive the rear wheels to turn in another direction. When the hydraulic oil pressure at the LC point increases, the hydraulic oil at the E end of the rear steering cylinder 15 flows back to the second oil tank 13 through the fifth relief valve 22 and the T2 point. The first solenoid valve 24, the second solenoid valve 25, the third solenoid valve 26, the fourth solenoid valve 27 and the fifth solenoid valve 28 are all controlled by the controller through electrical signals to control the valve core position.

[0044] This solution has the following key technical aspects: 1. Solenoid valve pilot control structure: The combination of the second solenoid valve 25, the third solenoid valve 26, the fourth solenoid valve 27 and the fifth solenoid valve 28 forms a directional valve pilot control structure, which precisely controls the action of the fourth directional valve 18.

[0045] 2. Independent control of rear wheel steering: The rear wheel steering module achieves independent steering through the coordinated operation of various directional valves, solenoid valves and rear steering cylinder 15.

[0046] 3. Precise adjustment of hydraulic oil pressure: Using the relief valve and priority valve 20, the system pressure is kept stable to avoid overload or loss of control.

[0047] Example 2 A vehicle, which is a four-wheeled automobile, includes front wheels and rear wheels, and also includes the aforementioned four-wheel steering electro-hydraulic control system. The front steering cylinder 3 is connected to the front wheel via a linkage mechanism and is used to drive the front wheel and control the steering action of the front wheel; the rear steering cylinder 15 is connected to the rear wheel via a linkage mechanism and is used to drive the rear wheel and control the steering action of the rear wheel.

[0048] The beneficial effects of the technical solution of this utility model are: The four-wheel steering electro-hydraulic control system of this utility model has the following significant advantages: 1. Precise control: Through the combination of solenoid valves and directional valves, the steering angle of the front and rear wheels can be precisely controlled.

[0049] 2. Rapid response: The hydraulic system uses hydraulic oil as the medium to transmit power, resulting in low energy loss and fast response speed.

[0050] 3. Smooth transition: The hydraulic system can avoid jerking or shock during steering, ensuring smooth operation.

[0051] 4. High reliability: Key components (such as oil pumps and cylinders) have been proven through long-term practical application and have high reliability and stability.

[0052] 5. Innovation: There is currently no similar hydraulic system for four-wheel steering in China, filling a market gap.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

[0054] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A four-wheel steering electro-hydraulic control system, characterized in that, include: The front wheel steering module is used to drive the front wheels and control their steering action. The rear wheel steering module is used to drive the rear wheels and control their steering. The front wheel steering module includes: First fuel tank (1); The first gear pump (2) has its input port connected to the oil outlet of the first oil tank (1) and is used to draw hydraulic oil from the first oil tank (1). The front steering cylinder (3) has two ports, A and B, which are used to control the steering of the front wheels. The first reversing valve (4) is located between the front steering cylinder (3) and the first gear pump (2). The first reversing valve (4) has a P port, a T port, an L port and an R port, which are used to control the flow direction of hydraulic oil. The output port of the first gear pump (2) is connected to the P port through the first pipeline (7), the R port is connected to the A end of the front steering cylinder (3) through the second pipeline (8), and the L port is connected to the B end of the front steering cylinder (3) through the third pipeline (9). Steering mechanism (5) is used to control the connection between port P and any one of port R, port T, or port L; The first return pipeline (6) has an output end connected to the oil inlet of the first oil tank (1). The input end of the first return pipeline (6) has a first return pipe and a second return pipe. The inlet end of the first return pipe is connected to the second pipeline (8), and the inlet end of the second return pipe is connected to the third pipeline (9). The rear wheel steering module includes: Second fuel tank (13); The second gear pump (14) has its inlet connected to the outlet of the second oil tank (13) and is used to draw hydraulic oil from the second oil tank (13). The rear steering cylinder (15) has two ports, E and F, respectively. The reversing valve assembly connects the output port of the second gear pump (14) to the two ports of the rear steering cylinder (15) through the reversing valve assembly, and is used to control the hydraulic oil path so that the hydraulic oil enters from the E end or F end of the rear steering cylinder (15); The second return line (19) is used to return the hydraulic oil flowing into the rear steering cylinder (15) to the second oil tank (13).

2. The four-wheel steering electro-hydraulic control system according to claim 1, characterized in that, The front wheel steering module also includes an overflow valve assembly for adjusting and balancing system pipeline pressure, the overflow valve assembly comprising: A first overflow valve (10) is provided between the first pipeline (7) and the first return pipeline (6), and the first overflow valve (10) is provided on the first overflow pipe. The second overflow valve (11) is provided on the first return pipe. The third overflow valve (12) is installed on the second return pipe.

3. The four-wheel steering electro-hydraulic control system according to claim 1, characterized in that, The directional valve assembly includes a second directional valve (16), a third directional valve (17), and a fourth directional valve (18). The rear wheel steering module also includes: Priority valve (20), the output port of the second gear pump (14) is connected to the input port of the priority valve (20) through the fourth pipeline (29), the priority valve (20) is used to distribute the hydraulic oil flow; the output port of the second gear pump (14) is also connected to the input port of the second directional valve (16) through the fifth pipeline (30), the second directional valve (16) is used to control the hydraulic oil flow direction; the output end of the priority valve (20) is connected to the input end of the fourth directional valve (18) through the sixth pipeline (31), and connected to the oil inlet of the second oil tank (13) through the seventh pipeline (32); The output ports of the first solenoid valve (24) and the second directional valve (16) are respectively connected to the first solenoid valve (24), the third directional valve (17) and the second return line (19). The output port of the second directional valve (16) is connected to the second return line (19) for overflow. The first solenoid valve (24) is used to control the hydraulic oil signal and transmit it to the third directional valve (17). The output port of the third directional valve (17) is also connected to the solenoid valve assembly through the eighth pipeline (33). The solenoid valve assembly is used to receive electrical signals and control the action of the fourth directional valve (18) so that hydraulic oil enters from the E end or F end of the rear steering cylinder (15). The third directional valve (17) is also connected to the fourth relief valve (21). When the valve core of the third directional valve (17) is in the right side chamber, the hydraulic oil flows back to the second oil tank (13) through the fourth relief valve (21).

4. The four-wheel steering electro-hydraulic control system according to claim 3, characterized in that, The output end of the second return pipe (19) is connected to the oil inlet of the second oil tank (13). The input end of the second return pipe (19) is branched into a third return pipe and a fourth return pipe. The inlet end of the third return pipe is connected to the E end of the rear steering cylinder (15). A fifth overflow valve (22) is provided on the third return pipe. The inlet end of the fourth return pipe is connected to the F end of the rear steering cylinder (15). A sixth overflow valve (23) is provided on the fourth return pipe.

5. The four-wheel steering electro-hydraulic control system according to claim 4, characterized in that, The solenoid valve assembly includes a second solenoid valve (25), a third solenoid valve (26), a fourth solenoid valve (27), and a fifth solenoid valve (28). The second solenoid valve (25), the third solenoid valve (26), the fourth solenoid valve (27), and the fifth solenoid valve (28) are used to form a pilot control structure for a directional valve to precisely control the action of the fourth directional valve (18). The two ports of the fourth reversing valve (18) are C and D, respectively; The rear wheel steering module can achieve multiple rear wheel steering operation modes through different combinations of the conduction states of the second solenoid valve (25), the third solenoid valve (26), the fourth solenoid valve (27), and the fifth solenoid valve (28). These multiple operations include, but are not limited to: When the second solenoid valve (25) and the third solenoid valve (26) are turned on, and the fourth solenoid valve (27) and the fifth solenoid valve (28) are not turned on, the hydraulic oil flows directly back to the second oil tank (13). The fourth directional valve (18) receives the hydraulic oil signal and does not turn on. At this time, the rear steering cylinder (15) does not move. When the third solenoid valve (26) and the fourth solenoid valve (27) are turned on, and the second solenoid valve (25) and the fifth solenoid valve (28) are not turned on, the hydraulic oil is transmitted to the C end of the fourth directional valve (18) through the fourth solenoid valve (27). The fourth directional valve (18) receives the hydraulic oil signal and turns on, and the hydraulic oil flows to the third directional valve (17). Then, it flows from the third directional valve (17) to the E end of the rear steering cylinder (15) and controls the rear steering cylinder (15) to move. The hydraulic oil then flows out from the F end of the rear steering cylinder (15) and flows back to the second oil tank (13) through the sixth relief valve (23). When the second solenoid valve (25) and the fifth solenoid valve (28) are turned on, and the third solenoid valve (26) and the fourth solenoid valve (27) are not turned on, the hydraulic oil is transmitted to the D end of the fourth directional valve (18) through the fourth solenoid valve (27). The fourth directional valve (18) receives the hydraulic oil signal and turns on, and the hydraulic oil flows to the third directional valve (17). Then, it flows from the third directional valve (17) to the F end of the rear steering cylinder (15) and controls the rear steering cylinder (15) to move. The hydraulic oil then flows out from the E end of the rear steering cylinder (15) and flows back to the second oil tank (13) through the fifth relief valve (22).

6. The four-wheel steering electro-hydraulic control system according to claim 3, characterized in that, A second overflow pipe is provided between the output port of the third reversing valve (17) and the input port of the second reversing valve (16); When the pressure value at the output port of the third directional valve (17) exceeds the set value, the hydraulic oil is diverted through the second overflow pipe to the second directional valve (16) and the second directional valve (16) switches the valve core, so that the excess hydraulic oil flows back to the second oil tank (13).

7. The four-wheel steering electro-hydraulic control system according to claim 5, characterized in that, It also includes a controller for sending electrical signals to control the valve core position of the solenoid valve assembly to control the action of the solenoid valve assembly, thereby achieving precise control of the rear wheel steering.

8. A vehicle comprising front wheels and rear wheels, characterized in that, It also includes the four-wheel steering electro-hydraulic control system according to any one of claims 1-7, wherein the front steering cylinder (3) is connected to the front wheel through a linkage mechanism and is used to drive the front wheel and control the steering action of the front wheel; The rear steering cylinder (15) is connected to the rear wheel via a linkage mechanism and is used to drive the rear wheel and control the steering action of the rear wheel.

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