Active hydraulic suspension system with continuously variable and fast real-time adjustable stiffness

Abstract

The utility model discloses a kind of stiffness stepless quick real-time adjustable active hydraulic suspension systems, corresponding control unit is respectively set to each wheel of vehicle, each control unit is provided with oil tank and shock absorber, shock absorber is provided with rodless cavity and rod cavity, rodless cavity is connected to oil tank by lower cavity oil circuit, rod cavity is connected to oil tank by upper cavity oil circuit;Lower cavity oil circuit is provided with the lower cavity pressure sensor of monitoring rodless cavity real-time pressure value, upper cavity oil circuit is provided with the upper cavity pressure sensor of monitoring rod cavity real-time pressure value;Upper cavity pressure sensor, lower cavity pressure sensor connect suspension controller;When using, suspension controller is adjusted to the oil pressure of the two cavities of shock absorber according to the real-time feedback value of upper cavity pressure sensor, lower cavity pressure sensor, to adjust the stiffness of suspension system.

Description

Technical Field

[0001] This utility model relates to the field of vehicle suspension system technology, and in particular to an active hydraulic suspension system with stepless, rapid and real-time adjustable stiffness. Background Technology

[0002] The suspension system is a crucial component of a car, significantly impacting its ride comfort and handling stability. It elastically connects the car body to the wheels, transmitting forces and torques between them and continuously mitigating and absorbing shocks and vibrations during driving.

[0003] There are two main ways in which automotive suspension systems provide suspension stiffness: one is an air suspension system with air springs, where stiffness adjustment is achieved by adjusting the gas volume inside the air springs. This method is not only costly but also slow in terms of stiffness change, response time, and efficiency. The other is a hydraulic suspension system with hydro-air springs (such as accumulators). The accumulator provides system stiffness. Since the effective volume of the accumulator is a fixed value after manufacturing, the stiffness of a single accumulator is usually not adjustable. To achieve stiffness adjustment, different numbers of accumulators must be connected. This method only allows for multi-level adjustment based on the number of connected accumulators, not stepless stiffness adjustment. Neither of these methods significantly improves vehicle comfort.

[0004] Currently, fully hydraulic active suspension systems can achieve rapid stepless adjustment of damping by controlling the opening of a valve that connects the upper and lower chambers of the shock absorber. However, the effect of rapid stepless adjustment of damping is limited, the adjustable range is small, and it does not significantly improve vehicle comfort.

[0005] Currently, there is no effective solution in automotive suspension systems to achieve stepless, rapid, and real-time adjustment of shock absorber stiffness, which does not adequately improve vehicle comfort. Utility Model Content

[0006] To address the shortcomings of current automotive suspension systems in improving vehicle comfort, this applicant provides a structurally sound active hydraulic suspension system with continuously and rapidly adjustable stiffness in real time. By adjusting the oil supply pressure within the shock absorber in real time, the system achieves continuous and rapid stiffness adjustment, thereby improving vehicle comfort.

[0007] The technical solution adopted in this utility model is as follows:

[0008] An active hydraulic suspension system with stepless, rapid, and real-time adjustable stiffness is provided, with a control unit set for each wheel of the vehicle. Each control unit is equipped with an oil tank and a shock absorber. The shock absorber is equipped with a rodless chamber and a rod chamber. The rodless chamber is connected to the oil tank through a lower chamber oil circuit, and the rod chamber is connected to the oil tank through an upper chamber oil circuit.

[0009] A lower chamber pressure sensor is installed on the lower chamber oil circuit to monitor the real-time pressure value of the rodless chamber, and an upper chamber pressure sensor is installed on the upper chamber oil circuit to monitor the real-time pressure value of the rod chamber. The upper and lower chamber pressure sensors are connected to the suspension controller. In use, the suspension controller adjusts the oil pressure of the two chambers of the shock absorber according to the real-time feedback values ​​of the upper and lower chamber pressure sensors, thereby adjusting the stiffness of the suspension system.

[0010] As a further improvement to the above technical solution:

[0011] Energy storage devices are installed in the lower chamber oil circuit and the upper chamber oil circuit respectively. The upper chamber pressure sensor is installed between the rod chamber and the corresponding energy storage device, and the lower chamber pressure sensor is installed between the rodless chamber and the corresponding energy storage device.

[0012] Control valves are installed on the lower and upper oil circuits respectively. The control valves are connected to the suspension controller and control the opening and closing of the oil circuits.

[0013] The lower and upper oil circuits are independently connected to the oil tank. Oil pumps are installed on the lower and upper oil circuits, respectively. The oil pumps are connected to the control motor, and the control motor is connected to the suspension controller. In use, the suspension controller outputs control commands to the control motor and control valve based on the real-time feedback value of the pressure sensor, thereby adjusting the pressure in the two chambers of the shock absorber and thus adjusting the stiffness of the suspension system.

[0014] The lower and upper oil circuits converge into the main oil circuit, which in turn connects to the oil tank. A main oil pump is installed on the main oil circuit, which is connected to the main control motor. Proportional valves are installed on both the lower and upper oil circuits, and the main control motor and proportional valves are connected to the suspension controller. During use, the suspension controller outputs control commands to the main control motor, proportional valves, and control valves based on the real-time feedback value from the pressure sensor, thereby adjusting the pressure in the shock absorber oil chamber and thus adjusting the stiffness of the suspension system.

[0015] When the stiffness of the suspension system is increased, the control motor is energized and the control valve is de-energized, and the system supplies oil from the oil tank to the shock absorber, increasing the oil volume in both chambers of the shock absorber; when the stiffness of the suspension system needs to be decreased, the control motor is de-energized and the control valve is energized, and the shock absorber oil flows back to the oil tank, reducing the oil volume in both chambers of the shock absorber.

[0016] The control motor adjusts its speed according to the control commands of the suspension controller, thereby regulating the oil pressure in the hydraulic circuit; the proportional valve adjusts its opening according to the control commands of the suspension controller, thereby regulating the oil pressure in the hydraulic circuit.

[0017] One-way valves are installed in the lower chamber oil circuit and the upper chamber oil circuit respectively. The one-way valves are located between the oil pump or proportional valve and the control valve.

[0018] An oil pump overflow valve is installed between the oil pump and the check valve, and the oil pump overflow valve is connected to the oil tank through an overflow circuit.

[0019] The beneficial effects of this utility model are as follows:

[0020] This invention enables real-time, rapid, and stepless adjustment of stiffness during vehicle operation, significantly improving vehicle comfort and stability. The real-time, rapid, and stepless stiffness adjustment offers a wider adjustable range and a better effect on improving vehicle comfort. Furthermore, when vibrations or impacts occur during vehicle operation, the real-time, rapid, and stepless stiffness adjustment allows for timely adjustment of the stiffness value, protecting the vehicle and providing a significant advantage in enhancing vehicle safety. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a first embodiment of the control unit of the 1 / 4 axle suspension system of this utility model.

[0022] Figure 2 This is a schematic diagram of a second embodiment of the control unit of the 1 / 4 axle suspension system of this utility model.

[0023] In the diagram: 1. Oil tank; 2. Shock absorber; 21. Rodless chamber; 22. Rod chamber; 3. Lower chamber oil pump; 31. Lower chamber oil pump overflow valve; 4. Lower chamber check valve; 5. Lower chamber accumulator; 6. Upper chamber oil pump; 61. Upper chamber oil pump overflow valve; 7. Upper chamber check valve; 8. Upper chamber accumulator; 11. Lower chamber control motor; 12. Upper chamber control motor; 13. Lower chamber control valve; 14. Upper chamber control valve; 17. Upper chamber pressure sensor; 18. Lower chamber pressure sensor; 9. Main oil pump; 91. Main oil pump overflow valve; 19. Main control motor; 32. Lower chamber proportional valve; 33. Upper chamber proportional valve;

[0024] 10. Lower chamber oil circuit; 20. Upper chamber oil circuit; 30. Main oil circuit. Detailed Implementation

[0025] The specific embodiments of this utility model are described below with reference to the accompanying drawings.

[0026] This invention provides an active hydraulic suspension system with continuously adjustable stiffness in real time, improving vehicle comfort, stability, and safety. The active hydraulic suspension system described in this invention is an independent suspension control system, with a control unit for each wheel of the vehicle. Example 1

[0027] like Figure 1As shown, each control unit is equipped with an oil tank 1 and a shock absorber 2, with the shock absorber 2 mounted on the wheel. The shock absorber 2 is provided with a rodless chamber 21 and a rod chamber 22. The rodless chamber 21 is connected to the oil tank 1 through a lower chamber oil passage 10, and the rod chamber 22 is connected to the oil tank 1 through an upper chamber oil passage 20.

[0028] On the lower chamber oil circuit 10, along the direction from the oil tank 1 to the rodless chamber 21, a lower chamber oil pump 3, a lower chamber check valve 4, a lower chamber control valve 13, and a lower chamber accumulator 5 are sequentially arranged. The lower chamber oil pump 3 is connected to and controlled by the lower chamber control motor 11. A lower chamber oil pump overflow valve 31 is installed between the lower chamber oil pump 3 and the lower chamber check valve 4. The lower chamber oil pump overflow valve 31 is connected to the oil tank 1 through an overflow circuit. The lower chamber oil pump overflow valve 31 is a system safety valve. When the outlet pressure of the lower chamber oil pump 3 reaches the set value of the lower chamber oil pump overflow valve 31, the lower chamber oil pump overflow valve 31 opens, and the pump oil flows back to the oil tank 1 through the lower chamber oil pump overflow valve 31, limiting the maximum pump outlet pressure to the set pressure of the lower chamber oil pump overflow valve 31, thus protecting the pump and the system. A lower chamber pressure sensor 18 is installed between the lower chamber accumulator 5 and the rodless chamber 21. The lower chamber pressure sensor 18 is used to monitor the real-time pressure value of the rodless chamber 21. The lower chamber control motor 11, lower chamber control valve 13, and lower chamber pressure sensor 18 are connected to the suspension controller. The lower chamber pressure sensor 18 provides the real-time pressure value to the suspension controller. The suspension system outputs control commands to the lower chamber control motor 11 and lower chamber control valve 13 through the control algorithm to adjust the oil pressure of the rodless chamber 21 of the shock absorber 2.

[0029] On the upper chamber oil circuit 20, along the direction from the oil tank 1 to the rod chamber 22, an upper chamber oil pump 6, an upper chamber check valve 7, an upper chamber control valve 14, and an upper chamber accumulator 8 are sequentially arranged. The upper chamber oil pump 6 is connected to the upper chamber control motor 12 and is controlled by the upper chamber control motor 12. An upper chamber oil pump overflow valve 61 is provided between the upper chamber oil pump 6 and the upper chamber check valve 7. The upper chamber oil pump overflow valve 61 is connected to the oil tank 1 through an overflow circuit. The upper chamber oil pump overflow valve 61 is a system safety valve. When the outlet pressure of the upper chamber oil pump 6 reaches the set value of the upper chamber oil pump overflow valve 61, the upper chamber oil pump overflow valve 61 opens, and the pump oil flows back to the oil tank 1 through the upper chamber oil pump overflow valve 61, limiting the maximum pump outlet pressure to the set pressure of the upper chamber oil pump overflow valve 61, thus protecting the pump and the system. An upper chamber pressure sensor 17 is provided between the upper chamber accumulator 8 and the rod chamber 22. The upper chamber pressure sensor 17 is used to monitor the real-time pressure value of the rod chamber 22. The upper chamber control motor 12, upper chamber control valve 14, and upper chamber pressure sensor 17 are connected to the suspension controller. The upper chamber pressure sensor 17 provides the pressure value to the suspension controller. The suspension system obtains the control commands of the upper chamber control motor 12 and upper chamber control valve 14 through the control algorithm, and adjusts the oil pressure of the rod chamber 22 of the shock absorber 2.

[0030] The lower chamber control motor 11 and the upper chamber control motor 12 adjust their speeds according to the control commands of the suspension controller, thereby adjusting the oil pressure in the two chambers of the shock absorber 2.

[0031] The lower chamber control valve 13 and the upper chamber control valve 14 are solenoid directional valves, and their control inputs are on / off inputs. When the lower chamber control valve 13 and the upper chamber control valve 14 are de-energized, they are closed, and the oil flows from the oil tank 1 to the shock absorber 2; when the lower chamber control valve 13 and the upper chamber control valve 14 are energized, they are open, and the oil flows from the shock absorber 2 to the oil tank 1. Of course, other types of control valves, such as solenoid switching valves, can also be used, as long as they can achieve the purpose of controlling the on / off state of the oil circuit.

[0032] When the stiffness of the suspension system needs to be increased, the lower chamber control motor 11 and the upper chamber control motor 12 are energized, while the lower chamber control valve 13 and the upper chamber control valve 14 are de-energized. The system then supplies oil from the oil tank 1 to the shock absorber 2, increasing the oil level in both chambers of the shock absorber 2. When the stiffness of the suspension system needs to be decreased, the lower chamber control motor 11 and the upper chamber control motor 12 are de-energized, while the lower chamber control valve 13 and the upper chamber control valve 14 are energized. The oil in the shock absorber 2 flows back to the oil tank 1, decreasing the oil level in both chambers of the shock absorber 2. Example 2

[0033] like Figure 2 As shown, unlike Embodiment 1, in this embodiment, the lower chamber oil passage 10 and upper chamber oil passage 20 of each control unit are not connected to the oil tank 1 separately, but are instead connected to the main oil passage 30 and then connected to the oil tank 1 through the main oil passage 30. The lower chamber oil passage 10 and upper chamber oil passage 20 are no longer equipped with oil pumps and oil pump overflow valves, but instead, a main oil pump 9 and a main oil pump overflow valve 91 are installed on the main oil passage 30. The main oil pump 9 is connected to the main control motor 19.

[0034] In this embodiment, a lower chamber proportional valve 32 is provided on the lower chamber oil circuit 10 between the connection point of the main oil circuit 30 and the lower chamber check valve 4. By controlling the opening degree of the lower chamber proportional valve 32, the flow rate of oil entering and exiting the rodless chamber 21 of the shock absorber 2 is controlled, thereby regulating the oil pressure of the rodless chamber 21. On the upper chamber oil circuit 20, an upper chamber proportional valve 33 is provided between the connection point of the main oil circuit 30 and the upper chamber check valve 7. By controlling the opening degree of the upper chamber proportional valve 33, the flow rate of oil entering and exiting the rod chamber 22 of the shock absorber 2 is controlled, thereby regulating the oil pressure of the rod chamber 22.

[0035] In this embodiment, while adjusting the oil pressure in the two chambers of the shock absorber 2, the power (speed and torque) of the main control motor 19 is controlled simultaneously.

[0036] The formula for calculating the stiffness of a hydro-air spring suspension system with an accumulator is:

[0037]

[0038] Where C is the spring stiffness; k is the thermodynamic polytropic index, where k=1 when the car vibrates slowly and the gas change is approximately isothermal, and k=1.4 when the car vibrates violently and the gas change is close to an adiabatic process; A is the area of ​​the shock absorber piston; p0 is the pre-charge pressure in the accumulator; V0 is the volume of the accumulator; p1 is the pressure inside the hydropneumatic spring at the design position, which is the equilibrium state caused by the design load; V1 is the gas volume inside the hydropneumatic spring at the design position; V x - The gas volume inside the gas spring when the piston displacement of the gas spring damper changes by x relative to the design position.

[0039] As can be seen from the above stiffness calculation formula, the stiffness of the suspension system is related to the piston area of ​​the shock absorber 2, the pre-charge pressure and volume of the energy storage device, the design position load, and the change in the gas volume inside the energy storage device caused by the dynamic excitation load. When the piston area of ​​the shock absorber 2, the pre-charge pressure and volume of the energy storage device, and the design position load remain unchanged, the change in the gas volume inside the energy storage device caused by the dynamic excitation load will cause a change in stiffness.

[0040] Each control unit of this utility model, based on actual working conditions, uses real-time feedback values ​​from the vehicle height sensor, upper chamber pressure sensor 17, and lower chamber pressure sensor 18 to output control commands to the suspension controller for the control motors (upper chamber control motor 12, lower chamber control motor 11, and main control motor 19) and / or valves (upper chamber control valve 14, lower chamber control valve 13, lower chamber proportional valve 32, and upper chamber proportional valve 33). When the required stiffness of the shock absorber 2 changes due to sudden changes in dynamic excitation load, the pressure of the rod chamber 22 and the rodless chamber 21 of the shock absorber 2 can be adjusted quickly and in real time, so that the pressure of the rod chamber 22 and the rodless chamber 21 can quickly and stably reach the target value, and the stiffness of the suspension can be quickly adjusted to and stably maintained at the required stiffness value, thereby achieving stepless, rapid, and real-time adjustment of stiffness. When a wheel of the vehicle experiences a sudden load change due to road surface excitation, the suspension controller, based on real-time feedback values ​​received from various sensors, calculates and outputs commands to the control motor and control valve of the corresponding wheel control unit through a control algorithm. By controlling the control motor and control valve, the amount of oil entering and exiting the rodless chamber 21 and the rod chamber 22 of the shock absorber 2 is controlled, thereby regulating the oil chamber pressure. The oil chamber pressure of the accumulator in the rodless chamber 21 and the rod chamber 22 of the shock absorber 2 is independently controlled. While ensuring the stability of the vehicle body height, the change in gas volume in the accumulator caused by the excitation load is changed, thereby achieving rapid adjustment of the suspension system stiffness. According to different load changes, by controlling the amount of oil entering and exiting the rodless chamber 21 and the rod chamber 22, the change in gas volume in the accumulator caused by the excitation load is rapidly and steplessly adjusted in real time, thereby achieving real-time rapid stepless adjustment of the suspension system stiffness.

[0041] This invention enables real-time, rapid, and stepless adjustment of stiffness during vehicle operation, significantly improving vehicle comfort and stability. The real-time, rapid, and stepless stiffness adjustment offers a wider adjustable range and a better effect on improving vehicle comfort. Furthermore, when vibrations or impacts occur during vehicle operation, the real-time, rapid, and stepless stiffness adjustment allows for timely adjustment of the stiffness value, protecting the vehicle and providing a significant advantage in enhancing vehicle safety.

[0042] The above description is an explanation of the present utility model and not a limitation thereof. The present utility model can be modified in any form without departing from its spirit.

Claims

1. A stiffness continuously variable quick real-time adjustable active hydraulic suspension system, a control unit is respectively arranged for each wheel of a vehicle, characterized in that: Each control unit is equipped with an oil tank (1) and a shock absorber (2). The shock absorber (2) is equipped with a rodless chamber (21) and a rod chamber (22). The rodless chamber (21) is connected to the oil tank (1) through the lower chamber oil passage (10), and the rod chamber (22) is connected to the oil tank (1) through the upper chamber oil passage (20). A lower chamber pressure sensor (18) is installed on the lower chamber oil circuit (10) to monitor the real-time pressure value of the rodless chamber (21), and an upper chamber pressure sensor (17) is installed on the upper chamber oil circuit (20) to monitor the real-time pressure value of the rod chamber (22). The upper chamber pressure sensor (17) and the lower chamber pressure sensor (18) are connected to the suspension controller. In use, the suspension controller adjusts the oil pressure of the two chambers of the shock absorber (2) according to the real-time feedback values ​​of the upper chamber pressure sensor (17) and the lower chamber pressure sensor (18), thereby adjusting the stiffness of the suspension system.

2. The active hydraulic suspension system with continuously variable stiffness and fast real-time adjustability according to claim 1, characterized in that: Energy storage devices are respectively installed on the lower chamber oil passage (10) and the upper chamber oil passage (20). The upper chamber pressure sensor (17) is installed between the rod chamber (22) and the corresponding energy storage device, and the lower chamber pressure sensor (18) is installed between the rodless chamber (21) and the corresponding energy storage device.

3. The active hydraulic suspension system of claim 1, wherein: Control valves are respectively installed on the lower chamber oil circuit (10) and the upper chamber oil circuit (20). The control valves are connected to the suspension controller and control the opening and closing of the oil circuit.

4. The active hydraulic suspension system of claim 3, wherein: The lower chamber oil circuit (10) and the upper chamber oil circuit (20) are independently connected to the oil tank (1). Oil pumps are installed on the lower chamber oil circuit (10) and the upper chamber oil circuit (20). The oil pumps are connected to the control motor, and the control motor is connected to the suspension controller. When in use, the suspension controller outputs control commands to the control motor and control valve according to the real-time feedback value of the pressure sensor, and adjusts the pressure of the two chambers of the shock absorber (2), thereby adjusting the stiffness of the suspension system.

5. The active hydraulic suspension system of claim 3, wherein: The lower chamber oil circuit (10) and the upper chamber oil circuit (20) converge into the main oil circuit (30) and are connected to the oil tank (1) through the main oil circuit (30); the main oil circuit (30) is equipped with a main oil pump (9), which is connected to the main control motor (19); the lower chamber oil circuit (10) and the upper chamber oil circuit (20) are respectively equipped with proportional valves, and the main control motor (19) and the proportional valves are connected to the suspension controller; when in use, the suspension controller outputs control commands to the main control motor (19), the proportional valves, and the control valves according to the real-time feedback value of the pressure sensor, so as to adjust the pressure of the oil chamber of the shock absorber (2) and thus adjust the stiffness of the suspension system.

6. The actively controlled hydraulic suspension system with continuous quick real-time adjustable stiffness according to any one of claims 3-5, characterized in that: When the stiffness of the suspension system is increased, the control motor is energized and the control valve is de-energized. The system supplies oil from the oil tank (1) to the shock absorber (2), increasing the oil in the two chambers of the shock absorber (2). When the stiffness of the suspension system needs to be reduced, the control motor is de-energized and the control valve is energized. The oil in the shock absorber (2) flows back to the oil tank (1), reducing the oil in the two chambers of the shock absorber (2).

7. The active hydraulic suspension system with continuously variable stiffness and fast real-time adjustability according to claim 4 or 5, characterized in that: The control motor adjusts its speed according to the control commands of the suspension controller, thereby regulating the oil pressure in the hydraulic circuit; the proportional valve adjusts its opening according to the control commands of the suspension controller, thereby regulating the oil pressure in the hydraulic circuit.

8. The active hydraulic suspension system with continuously variable stiffness and fast real-time adjustability according to claim 4 or 5, characterized in that: One-way valves are respectively installed on the lower chamber oil circuit (10) and the upper chamber oil circuit (20), and the one-way valves are located between the oil pump or proportional valve and the control valve.

9. The active hydraulic suspension system with continuously variable stiffness and fast real-time adjustability according to claim 4 or 5, characterized in that: An oil pump overflow valve is installed between the oil pump and the check valve, and the oil pump overflow valve is connected to the oil tank (1) through an overflow circuit.

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