Active hydro-pneumatic suspension system

Abstract

The utility model belongs to the technical field of vehicle suspension systems, and particularly relates to an active oil gas suspension system which comprises a hydraulic cylinder, a hydraulic two-way pump, a motor and two one-way throttling energy storage branches, the motor is connected with the hydraulic two-way pump, and the hydraulic two-way pump is respectively communicated with a rod cavity and a rodless cavity of the hydraulic cylinder; the two one-way throttling energy storage branches are connected with a rod cavity and a rodless cavity of the hydraulic cylinder respectively, each one-way throttling energy storage branch comprises an energy accumulator and a one-way throttling valve which are connected in series, and each one-way throttling valve comprises a one-way valve and a throttling valve which are connected in parallel; when the hydraulic cylinder is compressed and stretched, the two one-way throttling energy storage branches control fluid to flow in opposite directions. The active hydro-pneumatic suspension system is simple in structure and capable of effectively improving the performance of a vehicle and reducing energy consumption at the same time.

Description

Technical Field

[0001] This utility model belongs to the technical field of vehicle suspension systems, specifically relating to an active hydropneumatic suspension system. Background Technology

[0002] The suspension is one of the most important assemblies in a car. It elastically connects the chassis or body to the axles or wheels, transmitting torque and mitigating road impacts, thus affecting the vehicle's handling stability and ride comfort. Hydro-pneumatic suspension uses hydraulic pressure transmission and an inert gas as the elastic medium. It not only has excellent cushioning and energy storage capabilities but also offers ride height adjustment, further improving ride comfort. Hydro-pneumatic suspension shows great promise for use in heavy-duty vehicles and off-road vehicles.

[0003] Traditional hydropneumatic suspensions are passive suspensions. Currently, controllable hydropneumatic suspensions can be divided into semi-active and active hydropneumatic suspensions. Semi-active hydropneumatic suspensions can adjust the damping of their shock absorbers to better adapt the vehicle to different road conditions, but the improvement effect is limited. Active hydropneumatic suspensions mainly rely on actuators such as hydraulic pumps and motors to actively adjust the vehicle's posture, which can significantly improve the ride comfort of the vehicle, but still have disadvantages such as complex structure, excessive energy consumption, and very high cost.

[0004] Chinese patent CN206344652U discloses a hydropneumatic suspension system capable of switching between active and semi-active control. The system includes a controller connected to a vehicle attitude signal device and a vehicle driving signal device, controlling a motor, an electromagnetic directional valve, and an accumulator switch. The motor drives an oil pump, one end of which is connected to a filter and then to an oil tank, while the other end is connected to a check valve and then to the A port of the electromagnetic directional valve. A relief valve connects between the check valve and the oil pump, connecting the filter and the oil tank. A branch of the relief valve between the filter and the oil tank connects to the B port of the electromagnetic directional valve. One end of the accumulator switch is connected between the P port of the electromagnetic directional valve and a hydraulic cylinder, while the other end is connected to an accumulator. This suspension system switches between active and semi-active modes by controlling the switching of the electromagnetic directional valve. However, the accumulator limits the total travel of this suspension system to a small value. In semi-active mode, it cannot individually adjust the damping for compression or extension strokes, while in active mode, the operating speed is low. The two modes cannot be coordinated, resulting in coupling effects.

[0005] Therefore, a new type of active hydropneumatic suspension system is needed that can effectively improve vehicle performance and reduce energy consumption. Utility Model Content

[0006] The purpose of this invention is to provide an active hydropneumatic suspension system to solve the technical problems of complex structure and high energy consumption in existing hydropneumatic suspension systems.

[0007] To solve the above problems, the active hydropneumatic suspension system provided by this utility model adopts the following technical solution:

[0008] An active hydropneumatic suspension system includes a hydraulic cylinder, a hydraulic bidirectional pump, a motor, and two unidirectional throttling energy storage branches;

[0009] The motor is connected to the hydraulic bidirectional pump;

[0010] The hydraulic bidirectional pump is connected to both the rod-side chamber and the rodless chamber of the hydraulic cylinder.

[0011] Two one-way throttling energy storage branches are connected to the rod chamber and rodless chamber of the hydraulic cylinder, respectively. Each one-way throttling energy storage branch includes an accumulator and a one-way throttling valve connected in series. The one-way throttling valve includes a one-way valve and a throttling valve connected in parallel. The two one-way throttling energy storage branches control fluid flow in opposite directions during the compression and tension processes of the hydraulic cylinder, respectively.

[0012] Furthermore, in both unidirectional throttling energy storage branches, the fluid flows into the accumulator through the throttling valve and flows out of the accumulator through the one-way valve.

[0013] Furthermore, a safety branch is connected between the rod-side chamber and the rodless chamber of the hydraulic cylinder.

[0014] Furthermore, the safety branch includes two relief valves connected in parallel, with the two relief valves controlling fluid flows in opposite directions.

[0015] Furthermore, the throttle valve is an electrically controlled throttle valve.

[0016] Furthermore, the rod chamber sidewall of the hydraulic cylinder is provided with a first communication port and a second communication port, and the rodless chamber sidewall of the hydraulic cylinder is provided with a third communication port and a fourth communication port. The hydraulic bidirectional pump is connected to the second communication port and the fourth communication port respectively, and the two accumulators are connected to the first communication port and the third communication port respectively through two one-way throttle valves.

[0017] Furthermore, the two accumulators are of the same model.

[0018] Furthermore, the two check valves are of the same model.

[0019] Furthermore, the two throttle valves are of the same model.

[0020] The beneficial effects of this utility model are:

[0021] 1. When the motor is controlled, the active hydropneumatic suspension system operates in fully active mode. The active hydropneumatic suspension system of this application can adjust the damping force of the compression and extension strokes by adjusting the opening of two throttle valves, achieving stepless adjustment. This results in simple control, a lightweight structure, and low energy consumption. The fully active mode of the hydropneumatic suspension offers fast operation and high efficiency. In active mode, the hydropneumatic suspension system of this application can control the motor to quickly adjust the speed of the hydraulic pump, directly applying hydraulic pressure to the piston rod to achieve active driving power. The opening of the throttle valves can be adjusted to complement the active mode's operation, reducing energy consumption while ensuring improved vehicle ride comfort.

[0022] 2. Two-way overload protection is designed in the active compression stroke and active extension stroke to ensure the safe and stable operation of the active hydropneumatic suspension system. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the active hydropneumatic suspension system of this utility model;

[0024] Figure 2 This is a schematic diagram of the oil flow direction of the active hydropneumatic suspension system of this utility model when it is in the active compression stroke;

[0025] Figure 3 This is a schematic diagram of the oil flow direction when the active hydropneumatic suspension system of this utility model is in the active extension stroke.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Piston rod; 2. Hydraulic cylinder; 3. First one-way throttle valve; 4. Second one-way throttle valve; 5. First accumulator; 6. Second accumulator; 7. First relief valve; 8. Second relief valve; 9. Hydraulic bidirectional pump; 10. Motor. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Those skilled in the art should understand that the embodiments described below are only some, not all, of the embodiments disclosed. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0029] An embodiment of the active hydropneumatic suspension system provided by this utility model:

[0030] like Figure 1 , Figure 2 and Figure 3 As shown, the active hydropneumatic suspension system includes a hydraulic cylinder 2, a hydraulic bidirectional pump 9, a motor 10, two unidirectional throttling energy storage branches, and a safety branch.

[0031] The hydraulic cylinder 2 includes a cylinder body, a piston located inside the cylinder body, and a piston rod 1 connected to the piston. The piston divides the internal space of the hydraulic cylinder 2 into a rod chamber and a rodless chamber. The other end of the piston rod 1 extends out of the cylinder body of the hydraulic cylinder 2. A first communication port and a second communication port are provided on the side wall of the rod chamber; a third communication port and a fourth communication port are provided on the side wall of the rodless chamber.

[0032] The two unidirectional throttling energy storage branches are designated as the first unidirectional throttling energy storage branch and the second unidirectional throttling energy storage branch. The first unidirectional throttling energy storage branch includes a first accumulator 5 and a first unidirectional throttling valve 3 connected in series; the second unidirectional throttling energy storage branch includes a second accumulator 6 and a second unidirectional throttling valve 4 connected in series. The first accumulator 5 is connected to the first connecting port through the first unidirectional throttling valve 3; the second accumulator 6 is connected to the third connecting port through the second unidirectional throttling valve 4. Specifically, the first accumulator 5 is connected to the rod-side chamber of the hydraulic cylinder 2 through the first unidirectional throttling valve 3, and the second accumulator 6 is connected to the rodless chamber of the hydraulic cylinder 2 through the second unidirectional throttling valve 4.

[0033] In this embodiment, both the first one-way throttle valve 3 and the second one-way throttle valve 4 are electrically controlled one-way throttle valves. The first one-way throttle valve 3 includes a first one-way valve and a first throttle valve connected in parallel, and the second one-way throttle valve 4 includes a second one-way valve and a second throttle valve connected in parallel. The first throttle valve and the second throttle valve adjust their opening degree by changing the input current, thereby regulating the flow rate. The oil circulates between the first accumulator 5, the second accumulator 6, the rodless chamber, and the rod chamber. The oil in the rodless chamber flows into the second accumulator 6 through the second throttle valve, and the oil in the rod chamber flows into the first accumulator 5 through the first throttle valve. The oil in the first accumulator 5 flows into the rod chamber through the first one-way valve, and the oil in the second accumulator 6 flows into the rodless chamber through the second one-way valve.

[0034] In this embodiment, the first accumulator 5 is of the same model as the second accumulator 6, the first check valve and the second check valve are of the same model, and the first throttle valve and the second throttle valve are of the same model. This achieves balanced damping adjustment and energy storage during the active compression stroke and active extension stroke.

[0035] The motor 10 is connected to the hydraulic bidirectional pump 9, which is connected to the second and fourth connecting ports respectively.

[0036] A safety branch is also connected between the rod-side chamber and the rodless chamber, including a first relief valve 7 and a second relief valve 8 connected in parallel; the first relief valve 7 and the second relief valve 8 control the flow direction of the fluid to be opposite. The first relief valve 7 and the second relief valve 8 act as safety valves, capable of providing overload protection during the active compression stroke and the active extension stroke, respectively.

[0037] The specific working principle of the active hydropneumatic suspension system in this application is as follows:

[0038] like Figure 2 As shown, during the active compression stroke of the active hydropneumatic suspension system, the hydraulic bidirectional pump 9 pumps oil to the rod chamber of the hydraulic cylinder 2 to provide active force, at which time the piston rod 1 moves downward; the oil inside the rod chamber enters the first accumulator 5 through the first throttle valve to achieve energy storage and buffering, while the oil in the second accumulator 6 flows into the rodless chamber through the second check valve to replenish the oil in the rodless chamber, and the oil in the rodless chamber flows back to the hydraulic bidirectional pump 9 to maintain oil circulation.

[0039] like Figure 3 As shown, during the active extension stroke of the active hydropneumatic suspension system, the hydraulic bidirectional pump 9 pumps oil into the rodless chamber of the hydraulic cylinder 2 to provide active force, and the piston rod 1 moves upward; the oil inside the rodless chamber enters the second accumulator 6 through the second throttle valve, the oil in the first accumulator 5 flows into the rod chamber through the first check valve, and the oil in the rod chamber flows back to the hydraulic bidirectional pump 9, completing the circulation of the oil.

[0040] Based on the vehicle posture signal and road surface prediction information, the desired damping force can be calculated. By controlling the speed of the motor 10, the flow rate of the hydraulic two-way pump 9 is adjusted, thereby changing the oil pressure and flow rate, which directly drives the piston rod 1 to generate the required working force. At the same time, by adjusting the opening of the first one-way throttle valve 3 and the second one-way throttle valve 4, the damping force of the compression stroke and extension stroke can be adjusted respectively, realizing stepless adjustment to adapt to different road conditions and driving needs.

[0041] This invention provides an active hydropneumatic suspension system. When the control motor 10 is activated, the active hydropneumatic suspension system operates in a fully active mode. This active hydropneumatic suspension system allows for stepless adjustment of the damping force during the compression and extension strokes by adjusting the opening of two electronically controlled one-way throttle valves. This results in simple control, a lightweight structure, and low energy consumption. The fully active mode of the active hydropneumatic suspension system offers fast operation and high efficiency. In fully active mode, the motor 10 can be controlled to rapidly adjust the speed of the hydraulic bidirectional pump 9, directly applying hydraulic pressure to the piston rod 1 to achieve the active driving power effect. The opening of the electronically controlled one-way throttle valves can be adjusted to complement the fully active mode's operation, reducing energy consumption while ensuring improved vehicle ride comfort.

[0042] It should be noted that the models of the first accumulator 5 and the second accumulator 6 can also be different, as can the models of the first check valve and the second check valve, and the models of the first throttle valve and the second throttle valve. For example, typically, the volume of the rodless chamber of a hydraulic cylinder is larger than that of the rod chamber. If the same amount of energy needs to be stored under the same pressure change, the second accumulator 6 needs to have a larger volume. During the active compression stroke, the pressure change in the rod chamber may differ from the pressure change in the rodless chamber during the extension stroke. Energy storage efficiency can be optimized by using accumulators of different specifications. If the same damping force gradient is desired during the compression / extension strokes, the second check valve 4 (corresponding to the rodless chamber) may need a larger diameter or a looser throttling characteristic to match the larger oil flow requirements of the rodless chamber.

[0043] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An active hydropneumatic suspension system, characterized in that, Includes a hydraulic cylinder, a two-way hydraulic pump, a motor, and two one-way throttling energy storage branches; The motor is connected to the hydraulic bidirectional pump; The hydraulic bidirectional pump is connected to both the rod-side chamber and the rodless chamber of the hydraulic cylinder. Two one-way throttling energy storage branches are connected to the rod chamber and rodless chamber of the hydraulic cylinder, respectively. Each one-way throttling energy storage branch includes an accumulator and a one-way throttling valve connected in series. The one-way throttling valve includes a one-way valve and a throttling valve connected in parallel. The two one-way throttling energy storage branches control fluid flow in opposite directions during the compression and tension processes of the hydraulic cylinder, respectively.

2. The active hydropneumatic suspension system according to claim 1, characterized in that, In both unidirectional throttling energy storage branches, the fluid flows into the accumulator through the throttling valve and flows out of the accumulator through the one-way valve.

3. The active hydropneumatic suspension system according to claim 1, characterized in that, A safety branch is connected between the rod chamber and the rodless chamber of the hydraulic cylinder.

4. The active hydropneumatic suspension system according to claim 3, characterized in that, The safety branch includes two relief valves connected in parallel, with the two relief valves controlling fluid flows in opposite directions.

5. An active hydropneumatic suspension system according to any one of claims 1-4, characterized in that, The throttle valve is an electrically controlled throttle valve.

6. An active hydropneumatic suspension system according to any one of claims 1-4, characterized in that, The hydraulic cylinder has a first and a second connecting port on the rod chamber sidewall, and a third and a fourth connecting port on the rodless chamber sidewall. The hydraulic bidirectional pump is connected to the second and fourth connecting ports respectively, and the two accumulators are connected to the first and third connecting ports respectively through two one-way throttle valves.

7. The active hydropneumatic suspension system according to claim 1, characterized in that, The two accumulators are of the same model.

8. The active hydropneumatic suspension system according to claim 1, characterized in that, The two check valves are of the same model.

9. The active hydropneumatic suspension system according to claim 1, characterized in that, The two throttle valves are of the same model.

Images