Active hydraulic suspension

Abstract

The application discloses an active hydraulic suspension, which comprises an actuator, a compression damping valve assembly, a recovery damping valve assembly, a pulsation accumulator, a bidirectional hydraulic pump and a balance accumulator; the first end of the bidirectional hydraulic pump is connected with the first end of the actuator and the compression damping valve assembly respectively, the second end of the bidirectional hydraulic pump is connected with the second end of the actuator and the recovery damping valve assembly respectively, the compression damping valve assembly and the recovery damping valve assembly are connected with two ends of the balance accumulator respectively, and the pulsation accumulator is arranged between the bidirectional hydraulic pump and the compression damping valve assembly and between the bidirectional hydraulic pump and the recovery damping valve assembly respectively; the double-accumulator split structure of the pulsation accumulator and the balance accumulator is adopted, the use demand of the system on the air chamber volume is met, the gas rebound force is weakened, the oil cavitation risk is reduced, the transverse size of the shock absorber is not increased, the interference problem of the chassis assembly with surrounding components is effectively avoided, and the whole vehicle arrangement adaptability is improved.

Description

Technical Field

[0001] This invention relates to the field of automotive suspension technology, and more specifically, to an active hydraulic suspension. Background Technology

[0002] With the development of electronically controlled suspension technology, fully active suspension systems monitor the vehicle body and wheel status in real time, and the suspension controller calculates and outputs control signals to drive hydraulic actuators to generate active force within milliseconds. This directly counteracts road excitation and vehicle inertial force, thereby controlling the vehicle body posture and achieving ultimate smoothness, stability, and handling. This represents a new stage in suspension technology, moving from "passive adaptation" to "active control".

[0003] Currently, existing fully active suspension systems integrate accumulators and shock absorbers, with the accumulator mounted obliquely at the lower end of the shock absorber. Single-accumulator fully active suspension systems require a large accumulator chamber volume to minimize the impact of gas rebound force on damping force and reduce the risk of system cavitation. However, the accumulator's external dimensions are typically not very compact, significantly increasing the overall lateral dimensions of the shock absorber, which is detrimental to chassis mounting and increases the risk of interference with other components.

[0004] Furthermore, existing technology uses a positively open dual-valve as the damping control valve, meaning the damping control valve cannot be completely closed; even at maximum control current, the damping valve still has a certain opening for oil to pass through. A positively open damping valve is detrimental to the establishment of system power; after quickly adjusting the suspension height, maintaining the height will continuously consume energy and generate a large amount of heat, making it impossible to maintain height control for an extended period.

[0005] Therefore, how to provide an active hydraulic suspension has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a new technical solution for active hydraulic suspension.

[0007] According to a first aspect of the present invention, an active hydraulic suspension is provided, comprising: an actuator, a compression damping valve assembly, a recovery damping valve assembly, a pulsating accumulator, a bidirectional hydraulic pump, and a balance accumulator;

[0008] The first end of the bidirectional hydraulic pump is connected to the first end of the actuator and the compression damping valve assembly, respectively. The second end of the bidirectional hydraulic pump is connected to the second end of the actuator and the recovery damping valve assembly, respectively. The compression damping valve assembly and the recovery damping valve are respectively connected to the two ends of the balance accumulator. The pulsating accumulator is respectively disposed between the bidirectional hydraulic pump and the compression damping valve assembly, and between the bidirectional hydraulic pump and the recovery damping valve assembly.

[0009] The compression damping valve assembly includes a first check valve and a first zero-opening damping valve. The first check valve and the first zero-opening damping valve are connected in parallel, and the first end of the first check valve and the first end of the first zero-opening damping valve are both connected to the first end of the bidirectional hydraulic pump. The second end of the first check valve and the second end of the first zero-opening damping valve are both connected to the balance accumulator.

[0010] Optionally, the recovery damping valve assembly includes a second check valve and a second zero-opening damping valve. The second check valve and the second zero-opening damping valve are connected in parallel, and the first end of the second check valve and the first end of the second zero-opening damping valve are both connected to the second end of the bidirectional hydraulic pump. The second end of the second check valve and the second end of the second zero-opening damping valve are both connected to the balance accumulator.

[0011] Optionally, the actuator is equipped with a two-way safety valve.

[0012] Optionally, the active hydraulic suspension also includes a controller;

[0013] Both the first zero-opening damping valve and the second zero-opening damping valve are equipped with position sensors to detect the position of the valve core, and the controller is electrically connected to the position sensors.

[0014] Optionally, both the pulsating accumulator and the balancing accumulator are metal bellows accumulators.

[0015] Optionally, both the pulsating accumulator and the balanced accumulator include a housing, a bellows, and a sealing cap. The bottom of the housing is provided with an opening, and the sealing cap is inserted into the opening from the outside of the housing. The bellows is disposed inside the housing and is made of metal.

[0016] The bellows is filled with inert gas.

[0017] Optionally, the end of the housing is provided with a front flange for connecting to a hydraulic system.

[0018] Optionally, the housing is provided with a front cover and a rear flange inside, and the two ends of the bellows are respectively connected to the front cover and the rear flange, with a gap between the front cover and the front flange.

[0019] Optionally, the active hydraulic suspension further includes a motor connected to the bidirectional hydraulic pump.

[0020] The beneficial effects of this invention are as follows:

[0021] This invention employs a dual-accumulator split structure, consisting of a pulse accumulator and a balanced accumulator, abandoning the traditional design of integrating the accumulator with the lower end of the shock absorber at an angle. It eliminates the need for a single large-capacity accumulator located on the shock absorber body, satisfying the system's requirements for air chamber volume, reducing gas rebound force, and lowering the risk of oil cavitation, without increasing the lateral dimensions of the shock absorber. This effectively avoids interference with surrounding components during chassis assembly, improving overall vehicle layout adaptability. Furthermore, the compression damping valve assembly features a first zero-opening damping valve, combined with a parallel one-way valve, unlike traditional open dual-valve designs. The zero-opening structure of the damping valve allows for complete valve port closure, completely eliminating the inherent flow gap and ensuring that the hydraulic energy output from the bidirectional hydraulic pump is efficiently converted into suspension active force, significantly improving the system's active force establishment efficiency and response speed.

[0022] When the suspension completes height adjustment and maintains its posture, the zero-opening damping valve can cut off the oil flow channel, avoiding the ineffective work caused by the continuous oil flow of the traditional positive-opening valve, significantly reducing the continuous energy consumption of the system, suppressing the generation of a large amount of heat in the valve group and hydraulic circuit, and enabling the suspension to maintain the set height stably for a long time, thus improving the reliability and durability of the height control condition.

[0023] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0025] Figure 1 This is a structural diagram of the active hydraulic suspension of the present invention;

[0026] Figure 2 This is a structural diagram of the pulsed energy accumulator of the present invention.

[0027] The following are labeled in the diagram: 1. Actuator; 2. Compression damping valve assembly; 21. First check valve; 22. First zero-opening damping valve; 3. Reset damping valve assembly; 31. Second check valve; 32. Second zero-opening damping valve; 4. Pulsating accumulator; 41. Housing; 42. Bellows; 43. Air seal cover; 44. Front flange; 45. Front end cover; 46. Rear flange; 5. Bidirectional hydraulic pump; 6. Balance accumulator; 7. Motor. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0029] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0030] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0031] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0032] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides an active hydraulic suspension, including: an actuator 1, a compression damping valve assembly 2, a recovery damping valve assembly 3, a pulsating accumulator 4, a bidirectional hydraulic pump 5, and a balance accumulator 6.

[0033] The first end of the bidirectional hydraulic pump 5 is connected to the first end of the actuator 1 and the compression damping valve assembly 2, respectively. The second end of the bidirectional hydraulic pump 5 is connected to the second end of the actuator 1 and the recovery damping valve assembly 3, respectively. The compression damping valve assembly 2 and the recovery damping valve are connected to the two ends of the balance accumulator 6, respectively. The pulsating accumulator 4 is respectively disposed between the bidirectional hydraulic pump 5 and the compression damping valve assembly 2, and between the bidirectional hydraulic pump 5 and the recovery damping valve assembly 3.

[0034] The bidirectional hydraulic pump 5 plays a role in flow control in the closed hydraulic system. When controlling the main force, it works with the compression damping valve assembly 2 and the recovery damping valve assembly 3 to build up system pressure and output the main force. When controlling the damping, the damping bandwidth can be increased by controlling the direction and speed of the hydraulic pump.

[0035] The function of the pulsating accumulator 4 is to absorb the pressure pulsations caused by the bidirectional hydraulic pump 5, thereby improving the stability of the main power output. The function of the balancing accumulator 6 is to balance the changes in the amount of oil in the pipeline system during the movement of the shock absorber. The accumulator absorbs oil during the compression movement of the shock absorber and discharges oil during the recovery movement of the shock absorber.

[0036] The compression damping valve assembly 2 includes a first check valve 21 and a first zero-opening damping valve 22. The first check valve 21 and the first zero-opening damping valve 22 are connected in parallel, and the first end of the first check valve 21 and the first end of the first zero-opening damping valve 22 are both connected to the first end of the bidirectional hydraulic pump 5. The second end of the first check valve 21 and the second end of the first zero-opening damping valve 22 are both connected to the balance accumulator 6.

[0037] Specifically, the bidirectional hydraulic pump 5, the compression damping valve assembly 2, the recovery damping valve assembly 3, the pulsating accumulator 4, and the balance accumulator 6 form an independent and interconnected hydraulic circuit, which can precisely cooperate with the actuator 1 to complete millisecond-level active force output. It can not only rely on active control to offset road excitation and vehicle inertial force to ensure vehicle body posture stability, but also adjust the damping characteristics of compression and recovery strokes in zones to take into account vehicle ride comfort, driving stability and handling performance, and give full play to the technical advantages of active control of fully active suspension.

[0038] This invention employs a dual-accumulator split structure consisting of a pulse accumulator 4 and a balanced accumulator 6, abandoning the traditional design of integrating the accumulator with the lower end of the shock absorber at an angle. It eliminates the need for a single large-capacity accumulator located on the shock absorber body, satisfying the system's requirements for air chamber volume, reducing gas rebound force and lowering the risk of oil cavitation, without increasing the lateral dimensions of the shock absorber. This effectively avoids interference with surrounding components during chassis assembly, improving overall vehicle layout adaptability. Furthermore, the compression damping valve assembly 2 is equipped with a first zero-opening damping valve 22, combined with a one-way valve in parallel, unlike traditional open dual valves. The zero-opening structure of the damping valve allows for complete valve port closure, completely eliminating the inherent flow gap and ensuring that the hydraulic energy output from the bidirectional hydraulic pump 5 is efficiently converted into suspension active force, significantly improving the system's active force establishment efficiency and response speed.

[0039] When the suspension completes height adjustment and maintains its posture, the zero-opening damping valve can cut off the oil flow channel, avoiding the ineffective work caused by the continuous oil flow of the traditional positive-opening valve, significantly reducing the continuous energy consumption of the system, suppressing the generation of a large amount of heat in the valve group and hydraulic circuit, and enabling the suspension to maintain the set height stably for a long time, thus improving the reliability and durability of the height control condition.

[0040] In one embodiment of the active hydraulic suspension of the present invention, the recovery damping valve assembly 3 includes a second check valve 31 and a second zero-opening damping valve 32. The second check valve 31 and the second zero-opening damping valve 32 are arranged in parallel, and the first end of the second check valve 31 and the first end of the second zero-opening damping valve 32 are both connected to the second end of the bidirectional hydraulic pump 5. The second end of the second check valve 31 and the second end of the second zero-opening damping valve 32 are both connected to the balance accumulator 6.

[0041] Specifically, the recovery damping valve assembly 3 adopts a parallel structure of a second one-way valve 31 and a second zero-opening damping valve 32, forming a symmetrical layout with the compression-side valve group. The zero-opening structure of the second zero-opening damping valve 32 can achieve complete sealing of the valve port, solving the defect of traditional positive-opening valves that cannot completely cut off the flow, allowing the suspension recovery stroke to efficiently establish active hydraulic pressure and improve the active control capability throughout the entire stroke.

[0042] When the suspension is in recovery mode and height holding mode, the second zero-opening damping valve 32 can cut off the oil passage, eliminating the problem of continuous oil leakage and ineffective work caused by the valve port being open. In conjunction with the compression side valve group, it reduces the overall system energy consumption, reduces heat accumulation, and ensures the long-term stable operation of the height control function.

[0043] Compression damping valve assembly 2 and recovery damping valve assembly 3 correspond to the two major strokes of suspension compression and recovery, respectively. With the help of a one-way valve, the oil can be unidirectionally circulated, and the zero-opening damping valve can be adjusted to control the on / off state and damping. The damping parameters of the two strokes can be independently and precisely adjusted to match the shock absorption requirements under different driving conditions and simultaneously optimize the vehicle's ride comfort and handling.

[0044] In one embodiment of the active hydraulic suspension of the present invention, a two-way safety valve is provided on the actuator 1. The two-way safety valve can limit the pressure in both directions of movement of the actuator 1, and release pressure in time when the instantaneous pressure in the circuit surges abnormally, so as to avoid high pressure impact damaging the actuator 1, compression damping valve assembly 2, recovery damping valve assembly 3, two-way hydraulic pump 5 and other core components.

[0045] Furthermore, it can quickly absorb the instantaneous high pressure caused by road impacts and sudden changes in vehicle body posture, mitigate hydraulic shocks in pipelines, reduce oil cavitation, and ensure stable operation of the hydraulic system.

[0046] In one embodiment of the active hydraulic suspension of the present invention, the active hydraulic suspension further includes a controller;

[0047] Both the first zero-opening damping valve 22 and the second zero-opening damping valve 32 are equipped with position sensors to detect the position of the valve core. The controller is electrically connected to the position sensors.

[0048] It should be noted that traditional damping valves use open-loop control, which only controls the damping valve current, making it impossible to observe and monitor the actual state of the damping valve. Because damping valves are affected by hydraulic pressure, friction, and electromagnetic forces, open-loop control cannot solve the hysteresis problem of damping valves.

[0049] This invention uses position sensors to collect real-time valve core position signals of the first zero-opening damping valve 22 and the second zero-opening damping valve 32, accurately feeding back the valve opening degree and opening / closing state, allowing the controller to grasp the actual working conditions of the valve assembly. The controller combines the valve core position data to correct control commands, forming a closed-loop control, eliminating control deviations, and improving the accuracy and response speed of damping adjustment, active force output, and height control, which is beneficial for damping force and active force control.

[0050] Specifically, the controller receives a target displacement signal from the valve core of the suspension system. This signal is calculated by the vehicle controller based on the current driving conditions (such as road bumps, changes in vehicle posture, and height adjustment requirements), and represents the target opening position that the zero-opening damping valve needs to achieve.

[0051] The controller compares the target displacement of the valve core with the actual displacement of the valve core fed back by the position sensor, and calculates the deviation between the two. Based on the deviation, it outputs a corresponding control current signal through a built-in control algorithm (such as PID control) to drive the electromagnets in the first zero-opening damping valve 22 and the second zero-opening damping valve 32. After receiving the control current, the electromagnet generates an electromagnetic force proportional to the magnitude of the current. This electromagnetic force acts on the valve core, pushing it to move in the direction of the target displacement to adjust the actual opening of the valve.

[0052] When the valve core moves under the action of electromagnetic force, the position sensor collects the actual displacement of the valve core in real time and feeds it back to the controller to form a closed loop. The controller continuously compares the target displacement with the actual displacement and dynamically adjusts the control current until the actual displacement of the valve core is consistent with the target displacement, so as to achieve precise control of the valve opening.

[0053] In one embodiment of the active hydraulic suspension of the present invention, such as Figure 2 As shown, both the pulsating accumulator 4 and the balancing accumulator 6 are metal bellows 42 accumulators. The metal bellows 42 accumulator uses the bellows 42 as the elastic element, which has a fast response speed and stable working pressure. It can accurately match the functional requirements of the pulsating accumulator 4 to absorb high-frequency pressure pulsations and the balancing accumulator 6 to stabilize the system pressure, thereby improving the dynamic response and control accuracy of hydraulic circuit pressure regulation.

[0054] Furthermore, the bellows 42 structure can completely isolate oil and gas, eliminating the sealing and leakage risks of traditional bladder and piston accumulators, avoiding cavitation and elastic modulus changes caused by gas mixing into the oil, and ensuring the long-term stable operation of the fully active suspension hydraulic system.

[0055] The 42-type metal bellows accumulator allows for a compact, high-pressure-resistant structural design, eliminating the need for large installation space. It meets the system's requirements for air chamber volume without increasing the lateral dimensions of the shock absorbers or chassis, effectively avoiding interference with surrounding components and improving the overall vehicle chassis layout adaptability. It also possesses excellent fatigue and impact resistance, capable of withstanding high-frequency, repeated pressure changes from the suspension. Long-term operation carries no risk of aging or breakage, significantly extending the service life of the accumulator and hydraulic system, and reducing subsequent maintenance costs.

[0056] In one embodiment of the active hydraulic suspension of the present invention, only the structure of the pulse accumulator 4 is described in this embodiment. Both the pulse accumulator 4 and the balance accumulator 6 include a housing 41, a bellows 42 and an air seal 43. The bottom of the housing 41 is provided with an opening. The air seal 43 is inserted into the opening from the outside of the housing 41. The bellows 42 is disposed inside the housing 41 and the bellows 42 is made of metal.

[0057] The bellows 42 is filled with inert gas.

[0058] Specifically, the design of the sealing cap 43 being inserted into the bottom opening from the outside of the housing 41, combined with the all-metal elastic element structure of the metal bellows 42, achieves complete physical isolation between inert gas and hydraulic oil. This eliminates the problem of oil-gas crosstalk caused by aging or damage of the sealing lip of traditional bladder-type accumulators, avoids the risk of cavitation, system pressure drift and power output failure caused by gas mixing into the oil, and ensures the long-term stable operation of the suspension hydraulic system.

[0059] Furthermore, a front flange 44 is provided at the end of the housing 41 for connecting to the hydraulic system. When the liquid end pressure of the pulsating accumulator 4 and the balancing accumulator 6 is greater than the gas pressure inside the pulsating accumulator 4 and the balancing accumulator 6, the liquid pushes the front end face to move and compresses the metal bellows 42 and its inert gas. At this time, the pulsating accumulator 4 and the balancing accumulator 6 absorb liquid, and the gas pressure rises until it is balanced with the hydraulic system pressure. Conversely, when the liquid end pressure is less than the gas pressure inside the pulsating accumulator 4 and the balancing accumulator 6, the gas pushes the front end face to move and stretches the metal bellows 42. At this time, the pulsating accumulator 4 and the balancing accumulator 6 discharge liquid, and the gas pressure drops until it is balanced with the liquid end pressure.

[0060] In one embodiment of the active hydraulic suspension of the present invention, a front cover 45 and a rear flange 46 are provided inside the housing 41, and the two ends of the bellows 42 are respectively connected to the front cover 45 and the rear flange 46, and there is a gap between the front cover 45 and the front flange 44.

[0061] Specifically, the front cover 45 and the rear flange 46 provide reliable fixation at both ends of the bellows 42. The distance between the front cover 45 and the front flange 44 provides sufficient space for the axial expansion and contraction of the bellows 42, allowing the bellows 42 to be freely compressed and extended during the charging and degassing process of the accumulator. This avoids excessive stress caused by the limited deformation of the bellows 42 and ensures the normal elastic energy storage and pressure regulation functions of the accumulator.

[0062] This spacing can prevent the bellows 42 from rigidly colliding or being squeezed with the front cover 45 under extreme compression conditions, prevent local stress concentration, wrinkling deformation or even cracking of the bellows 42, significantly reduce the risk of fatigue damage under high-frequency pressure pulsation conditions, and improve the long-term working reliability and service life of the accumulator.

[0063] In one embodiment of the active hydraulic suspension of the present invention, the active hydraulic suspension further includes a motor 7, which is connected to a bidirectional hydraulic pump 5. The motor 7 provides independent power to the bidirectional hydraulic pump 5 and can adjust the speed and steering in real time according to the controller command, driving the hydraulic pump to output bidirectional hydraulic oil flow to the actuator 1, providing active support force for the suspension, realizing active control of vehicle body posture and height, and upgrading from "passive damping" to "active intervention".

[0064] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. An active hydraulic suspension, characterized in that, include: Actuators, compression damping valve assemblies, recovery damping valve assemblies, pulsating accumulators, bidirectional hydraulic pumps, and balance accumulators; The first end of the bidirectional hydraulic pump is connected to the first end of the actuator and the compression damping valve assembly, respectively. The second end of the bidirectional hydraulic pump is connected to the second end of the actuator and the recovery damping valve assembly, respectively. The compression damping valve assembly and the recovery damping valve are respectively connected to the two ends of the balance accumulator. The pulsating accumulator is respectively disposed between the bidirectional hydraulic pump and the compression damping valve assembly, and between the bidirectional hydraulic pump and the recovery damping valve assembly. The compression damping valve assembly includes a first check valve and a first zero-opening damping valve. The first check valve and the first zero-opening damping valve are connected in parallel, and the first end of the first check valve and the first end of the first zero-opening damping valve are both connected to the first end of the bidirectional hydraulic pump. The second end of the first check valve and the second end of the first zero-opening damping valve are both connected to the balance accumulator.

2. The active hydraulic suspension according to claim 1, characterized in that, The recovery damping valve assembly includes a second check valve and a second zero-opening damping valve. The second check valve and the second zero-opening damping valve are connected in parallel, and the first end of the second check valve and the first end of the second zero-opening damping valve are both connected to the second end of the bidirectional hydraulic pump. The second end of the second check valve and the second end of the second zero-opening damping valve are both connected to the balance accumulator.

3. The active hydraulic suspension according to claim 1, characterized in that, The actuator is equipped with a two-way safety valve.

4. The active hydraulic suspension according to claim 2, characterized in that, The active hydraulic suspension also includes a controller; Both the first zero-opening damping valve and the second zero-opening damping valve are equipped with position sensors to detect the position of the valve core, and the controller is electrically connected to the position sensors.

5. The active hydraulic suspension according to claim 1, characterized in that, Both the pulsating accumulator and the balanced accumulator are metal bellows accumulators.

6. The active hydraulic suspension according to claim 5, characterized in that, Both the pulsating accumulator and the balanced accumulator include a housing, a bellows, and a sealing cap. The bottom of the housing is provided with an opening, and the sealing cap is inserted into the opening from the outside of the housing. The bellows is disposed inside the housing and is made of metal. The bellows is filled with inert gas.

7. The active hydraulic suspension according to claim 6, characterized in that, The end of the housing is provided with a front flange for connecting to the hydraulic system.

8. The active hydraulic suspension according to claim 7, characterized in that, The housing has a front cover and a rear flange inside. The two ends of the bellows are connected to the front cover and the rear flange, respectively, and there is a gap between the front cover and the front flange.

9. The active hydraulic suspension according to claim 1, characterized in that, The active hydraulic suspension also includes a motor, which is connected to the bidirectional hydraulic pump.

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