Active hydraulic suspension liquid supply unit

Abstract

The utility model relates to the field of vehicle hydraulic suspensions, in particular to an active hydraulic suspension liquid supply unit, which is characterized in that electromagnetic valves with relatively small volumes are integrated in a valve block to form an integrated liquid supply unit, and the integrated liquid supply unit comprises a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve, a fourth electromagnetic valve and a one-way pump, the one-way pump is powered by a one-way motor, the first oil supply end of the first electromagnetic valve and the first oil supply end of the third electromagnetic valve are both communicated with a second liquid supply port of the active hydraulic suspension liquid supply unit, and the first oil supply end of the second electromagnetic valve and the first oil supply end of the fourth electromagnetic valve are both communicated with a first liquid supply port of the active hydraulic suspension liquid supply unit. The second oil feeding ends of the third electromagnetic valve and the fourth electromagnetic valve are communicated with the oil outlet end of the one-way pump, the second oil feeding ends of the first electromagnetic valve and the second electromagnetic valve are communicated with the oil inlet end of the one-way pump, control modes of different modes can be provided for a suspension according to different conditions, and therefore various defects of a suspension liquid supply system in the prior art are overcome.

Description

Technical Field

[0001] The utility model relates to the field of vehicle hydraulic suspension, in particular to an active hydraulic suspension fluid supply unit. Background Art

[0002] Suspension is the general term for all force-transmitting connections between a vehicle's frame and wheels. It is responsible for transmitting the forces and torque acting between the wheels and frame, as well as cushioning the impact forces transmitted to the frame or body from uneven roads, reducing the resulting vibrations to ensure a smooth ride. Traditional suspension is passive, with fixed stiffness and damping that cannot be adjusted during driving. Currently, it is primarily used in low-end vehicles, while active suspension is mostly used in mid- to high-end models. This is because the stiffness, height, and damping of active suspension can be adjusted in real time during driving, allowing the vehicle to travel smoothly on varying road conditions and provide excellent driving performance.

[0003] Active hydraulic suspension is a commonly used structural form of active suspension. It is mainly composed of hydraulic shock absorbers, electric motors, hydraulic pumps, solenoid valves, control units and hydraulic pipelines. The motors used are divided into two types: unidirectional motors and bidirectional motors.

[0004] In suspension systems employing bidirectional hydraulic pumps, a bidirectional internal gear pump is typically used to control the direction of the oil flow. However, a bidirectional internal gear pump has a complex internal structure, consisting of an internal gear, an external pinion, a crescent plate between the internal and external pinion gears, a pump body, a drive shaft, and more. Therefore, the internal operating conditions of a bidirectional internal gear pump in a suspension system are more complex, requiring higher standards in materials and processes to meet the durability requirements of such a suspension system.

[0005] The bidirectional hydraulic pump uses a bidirectional motor as its power source, which drives the hydraulic pump to deliver hydraulic oil in both directions, thereby achieving dynamic adjustment of the suspension. Due to the defects of the bidirectional motor itself, this suspension system still has the following shortcomings:

[0006] ① The suspension system's circuitry is complex: During dynamic suspension adjustments, the bidirectional motor changes its rotational direction by altering the current flow through its control circuit. However, this control circuit alone is insufficient to drive the bidirectional motor properly. Various additional functional modules are required, such as:

[0007] 1.1 Set up the drive circuit module so that the motor can obtain enough power to overcome the load resistance and drive the bidirectional motor to operate normally;

[0008] 1.2 Set up an overload protection module to prevent emergencies (such as overload, motor failure) from damaging the motor or even the entire control circuit.

[0009] Although the introduction of these additional functional modules ensures the normal operation of the bidirectional motor, it also greatly increases the circuit complexity of the entire suspension system and reduces the operational reliability of the suspension system.

[0010] ② The suspension system has difficulty controlling dynamic adjustments and has low control accuracy: In order to ensure that the vehicle can travel smoothly on different road surfaces, the commutation time of the bidirectional motor is often adjusted according to the current suspension load so that the hydraulic actuators (such as hydraulic cylinders and hydraulic motors) can smoothly transition when changing the direction of movement. However, when the bidirectional motor receives the commutation command from the suspension system and prepares to perform the commutation operation, the bidirectional motor is often affected by the rotational inertia due to the change in the direction of motor rotation. This rotational inertia will cause the bidirectional motor to continue to rotate in the current direction and speed for a period of time, which prolongs the commutation time of the motor, resulting in reduced control accuracy and increased control difficulty for the entire suspension system for dynamic adjustments, thereby reducing the handling performance of the suspension system;

[0011] ③ The suspension system has a high manufacturing technical threshold and high cost: The bidirectional motor contains a complex internal structure, including a commutator, stator windings, rotor windings, and other auxiliary structures. During vehicle operation, the suspension load changes dynamically and is difficult to predict. To cope with these loads, the suspension system often frequently switches the bidirectional motor's operating mode. However, frequent switching of operating modes accelerates wear of the bidirectional motor's internal components. Therefore, the suspension system can only use bidirectional motors with high strength, high hardness, and good wear resistance, which increases the technical threshold and cost of manufacturing hydraulic suspension.

[0012] To avoid these drawbacks of suspension systems using bidirectional hydraulic pumps and adapt them to more demanding environments, unidirectional hydraulic pumps are often used to construct automotive suspension systems. However, this creates a number of new technical problems. For example, "A Slow Active Hydraulic Suspension System Based on a Reversing Valve," published in CN116176198A, while avoiding the technical drawbacks of bidirectional hydraulic pumps, still suffers from the following drawbacks:

[0013] ① The unidirectional motor in a unidirectional hydraulic pump is multifunctional. It drives the hydraulic pump to draw hydraulic oil from the tank, pressurizes the oil, and controls the rise and fall of the shock absorber with the pressurized oil. It also drives the air compressor, which draws in and compresses outside air for delivery to the air spring. This multifunctional design requires the unidirectional motor's internal mechanical components (such as bearings, rotors, and stators) and various external transmission components (such as gears and belts) to frequently switch operating modes based on different functional requirements. This leads to complex friction and wear between the various transmission components, accelerating wear of the unidirectional motor and significantly shortening its service life.

[0014] ② A large, two-position, four-way solenoid directional valve (e.g., a solenoid directional valve measuring 200 mm long, 50 mm wide, and 85.5 mm high) is used in one-way hydraulic pumps to change the direction of fluid flow. This valve is primarily composed of a valve body, a valve core, an electromagnet, a spring, and other components. The valve body has four oil ports (inlet, return, working port A, and working port B). The valve has a complex internal structure and a large valve core mass. This results in high inertia during reversal, which prolongs the reversal time and prevents the vehicle from quickly reversing under operating conditions requiring it. Furthermore, the valve also requires a complex piping system, exponentially increasing the complexity of the entire suspension system layout and significantly increasing the cost (both manufacturing and maintenance) of the entire suspension system.

[0015] ③ The entire suspension system has no device to monitor pipeline pressure, nor does it have a pressure-limiting safety valve to protect the hydraulic pump. When the vehicle encounters certain abnormal conditions (such as driving on extremely bumpy roads), the wheels will be frequently subjected to high-intensity impacts. In order to cope with these impacts, the suspension system will continuously compress the hydraulic oil in the pipeline, resulting in excessive pipeline pressure. The high pressure of this pipeline will directly act on the hydraulic pump and continue until the vehicle is no longer affected by this abnormal condition. This process is very likely to directly destroy the entire one-way hydraulic pump (including the motor), causing the vehicle to have abnormal body posture (such as obvious sinking or tilting) and steering difficulties (such as understeer or oversteer) when driving, seriously affecting the safety of the vehicle driving process;

[0016] ④ A hydraulic pump separates the upper and lower chambers of the shock absorber. This structure allows the pump's ends to communicate directly with the upper and lower chambers of the shock absorber when not in operation. If the vehicle experiences a significant impact (such as high-speed travel over an uneven surface), the oil in the upper and lower chambers of the shock absorber will quickly surge into the hydraulic pump, causing a sharp increase in the oil level at both ends of the hydraulic pump. This in turn severely impacts the hydraulic pump, significantly reducing its service life and disrupting its efficiency. This structure necessitates the use of two accumulators to receive the hydraulic oil in the hydraulic system to prevent the life of the hydraulic pump from being shortened due to severe impact, significantly increasing the cost of the entire hydraulic suspension system.

[0017] How to avoid the technical defects of the suspension system using a bidirectional hydraulic pump while avoiding the technical defects of the current suspension system using a unidirectional hydraulic pump so as to fundamentally improve the technology of the entire suspension system has always been an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0018] The purpose of the present utility model is to address the corresponding deficiencies of the existing technology and provide an active hydraulic suspension fluid supply unit, which integrates a relatively small solenoid valve in a valve block to form an integrated fluid supply unit, and cooperates with a unidirectional motor to provide different modes of control for the suspension according to different situations, thereby avoiding various defects of the suspension fluid supply system in the existing technology.

[0019] The purpose of the present utility model is achieved by adopting the following scheme: an active hydraulic suspension fluid supply unit, comprising an integrated fluid supply unit, the integrated fluid supply unit being provided with a first fluid supply port and a second fluid supply port, which are used to respectively connect the two oil ports of the hydraulic shock absorber, the integrated fluid supply unit comprising a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, and a one-way pump, the one-way pump being powered by a one-way motor, the first oil delivery ends of the first solenoid valve and the third solenoid valve being connected to the second fluid supply port of the active hydraulic suspension fluid supply unit, the first oil delivery ends of the second solenoid valve and the fourth solenoid valve being connected to the first fluid supply port of the active hydraulic suspension fluid supply unit, the second oil delivery ends of the third solenoid valve and the fourth solenoid valve being connected to the oil outlet end of the one-way pump, and the second oil delivery ends of the first solenoid valve and the second solenoid valve being connected to the oil inlet end of the one-way pump.

[0020] Preferably, it further comprises a valve block having a size of 80 mm×80 mm×40 mm, and the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve are integrated in the valve block.

[0021] Preferably, the valve block is further provided with a pressure-limiting safety valve, the oil inlet of the pressure-limiting safety valve is communicated with the oil outlet of the one-way pump, and the oil outlet of the pressure-limiting safety valve is communicated with the oil inlet of the one-way pump.

[0022] Preferably, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve are all two-position, two-way solenoid valves.

[0023] Preferably, it also includes a continuous damping control unit, which is provided with a first damping control port and a second damping control port, and the continuous damping control unit is arranged between the hydraulic shock absorber and the integrated liquid supply unit, so that the first damping control port and the second damping control port of the continuous damping control unit are respectively connected to the first liquid supply port and the second liquid supply port of the integrated liquid supply unit, so as to realize continuous damping control of the suspension.

[0024] Preferably, the continuous damping control unit includes a first solenoid proportional valve, a first damping valve, a first one-way valve, a second solenoid proportional valve, a second damping valve, a second one-way valve, and an accumulator, one end of the first solenoid proportional valve, the first damping valve, the first one-way valve, the second solenoid proportional valve, the second damping valve, and the second one-way valve are all connected to the accumulator, the other end of the first solenoid proportional valve, the first damping valve, and the first one-way valve are all connected to the first damping control port of the continuous damping control unit, and the other end of the second solenoid proportional valve, the second damping valve, and the second one-way valve are all connected to the second damping control port of the continuous damping control unit.

[0025] The beneficial effects of the utility model are as follows:

[0026] An active hydraulic suspension fluid supply unit includes an integrated fluid supply unit, which is provided with a first fluid supply port and a second fluid supply port, which are used to respectively connect the two oil ports of the hydraulic shock absorber. The integrated fluid supply unit includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a fourth solenoid valve, and a one-way pump, which is powered by a one-way motor. The first oil delivery ends of the first solenoid valve and the third solenoid valve are both connected to the second fluid supply port of the active hydraulic suspension fluid supply unit, the first oil delivery ends of the second solenoid valve and the fourth solenoid valve are both connected to the first fluid supply port of the active hydraulic suspension fluid supply unit, the second oil delivery ends of the third solenoid valve and the fourth solenoid valve are connected to the oil outlet end of the one-way pump, and the second oil delivery ends of the first solenoid valve and the second solenoid valve are connected to the oil inlet end of the one-way pump.

[0027] The liquid supply system of this structure has a simple oil circuit structure and a small oil transportation path within the system. Through the mutual cooperation of various solenoid valves, the transportation state of the oil circuit can be quickly switched to cope with most working conditions that require rapid reversing.

[0028] Preferably, a valve block is further included, the size of which is 80mm×80mm×40mm, and the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve are integrated into the valve block. The first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve are all two-position two-way solenoid valves.

[0029] Since the two-position two-way solenoid valve is small in size, it will not take up too much internal space of the valve block. The oil passages connecting each solenoid valve to the outside can also be set inside the valve block, making the entire valve block fully functional but compact.

[0030] Preferably, the valve block is further provided with a pressure-limiting safety valve, the oil inlet of the pressure-limiting safety valve is communicated with the oil outlet of the one-way pump, and the oil outlet of the pressure-limiting safety valve is communicated with the oil inlet of the one-way pump.

[0031] In other words, to ensure the normal and stable operation of the hydraulic system, a pressure-limiting safety valve is also installed in the valve block. When the vehicle's hydraulic suspension system experiences an abnormality, the internal pressure of the hydraulic circuit where the one-way pump is located rises rapidly and exceeds the set value. The pressure-limiting safety valve will open, and some of the oil in the one-way pump will flow from the oil outlet of the one-way pump to the oil inlet of the pressure-limiting safety valve. Then, the oil outlet of the pressure-limiting safety valve will flow back to the oil inlet of the one-way pump, forming a pipeline pressure relief circuit to reduce the excessive oil pressure in the pipeline and prevent high pressure from impacting the hydraulic pump.

[0032] Preferably, the suspension further comprises a continuous damping control unit, which is provided with a first damping control port and a second damping control port, and is arranged between the hydraulic shock absorber and the integrated liquid supply unit, so that the first damping control port and the second damping control port of the continuous damping control unit are respectively connected to the first liquid supply port and the second liquid supply port of the integrated liquid supply unit, so as to realize continuous damping control of the suspension. The continuous damping control unit comprises a first electromagnetic proportional valve, a first damping valve, a first check valve, a second electromagnetic proportional valve, a second damping valve, a second check valve, and an accumulator, one end of the first electromagnetic proportional valve, the first damping valve, the first check valve, the second electromagnetic proportional valve, the second damping valve, and the second check valve are all connected to the accumulator, the other end of the first electromagnetic proportional valve, the first damping valve, and the first check valve are all connected to the first damping control port of the continuous damping control unit, and the other end of the second electromagnetic proportional valve, the second damping valve, and the second check valve are all connected to the second damping control port of the continuous damping control unit.

[0033] In this way, the present invention can adopt a variety of different modes to control the suspension according to different situations. The method of controlling the suspension using the above-mentioned active hydraulic suspension supply unit includes an active control mode, a semi-active continuous damping control mode, and a passive damping control mode, and sets a suspension vibration frequency threshold to determine the timing of entering each mode:

[0034] 1) When the real-time suspension vibration frequency is less than or equal to the suspension vibration frequency threshold, the active hydraulic suspension fluid supply unit uses the active control mode to control the suspension. The specific steps include:

[0035] 1-1) Calculating a current target moving speed of a piston of a hydraulic shock absorber using a real-time vehicle signal, wherein the target moving speed includes a target ascending speed or a target descending speed;

[0036] 1-2) Determine the type of target movement speed and control each valve in the following manner:

[0037] If the target moving speed is the target ascending speed, the second solenoid valve and the third solenoid valve are opened, and the other valves are closed;

[0038] If the target moving speed is the target descending speed, the first solenoid valve and the fourth solenoid valve are opened, and the other valves are closed;

[0039] 1-3) Use the motor speed-piston target movement speed characteristic curve to obtain the motor target speed, and make the motor real-time speed equal to the motor target speed;

[0040] 1-4) Repeat steps 1-1) to 1-3) with a repetition frequency equal to the real-time vibration frequency of the suspension.

[0041] 2) When the real-time suspension vibration frequency is greater than the suspension vibration frequency threshold, the active hydraulic suspension fluid supply unit uses a semi-active continuous damping control mode to control the suspension. The specific steps include:

[0042] 2-1) Close the one-way motor, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve;

[0043] 2-2) Using real-time vehicle signals, calculate the current target piston velocity of the hydraulic shock absorber and the target vertical force of the suspension.

[0044] 2-3) Based on the target piston movement speed and the target suspension vertical force obtained in step 2-2), query the shock absorber damping characteristic curve to obtain the current target openings of the first and second solenoid proportional valves, and set the real-time openings of the first and second solenoid proportional valves equal to the current target openings;

[0045] 2-4) Repeat steps 2-2) to 2-3) until the real-time vibration frequency of the suspension is no longer greater than the suspension vibration frequency threshold.

[0046] 3) When the active control mode and the semi-active continuous damping control mode fail, the one-way motor, as well as the first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, the first solenoid proportional valve, and the second solenoid proportional valve are turned off, and the active hydraulic suspension fluid supply unit adopts the passive damping control mode to control the suspension.

[0047] The advantages of the present invention are as follows:

[0048] ① Existing hydraulic systems have large motor rotational inertia, complex oil circuits, low switching frequency limits (typically only 5-6Hz), and a low active control frequency threshold. However, the present invention features a simple oil circuit structure and a smaller oil delivery path within the system. Through the coordinated operation of the various solenoid valves (the spools within the reversing valves are relatively lightweight), the oil circuit's delivery state can be rapidly switched. This results in a high switching frequency and a high active control frequency threshold (10-12Hz), enabling it to handle most operating conditions requiring rapid switching and maximizing vehicle handling stability and comfort.

[0049] ② This utility model features a simple system layout and low cost. It utilizes a few simple solenoid valves to isolate the hydraulic pump from the shock absorber. These solenoid valves protect the one-way pump from oil shock. This prevents the oil in the hydraulic shock absorber from rapidly compressing and impacting the one-way pump during severe vehicle impacts, significantly extending the lifespan (including service life) of the motor and hydraulic pump.

[0050] ③ This utility model adopts a unidirectional rotating motor. The motor products and control technology are very mature and the cost is lower. The unidirectional hydraulic pump has a low technical threshold and low cost, avoiding the problems of high technical threshold and high cost of components of the bidirectional hydraulic pump and the difficulty of controlling the bidirectional motor.

[0051] Glossary

[0052] Rotational inertia: It is a measure of the inertia of a rigid body when it rotates, and it is related to the mass distribution of the object and the position of the axis of rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a schematic diagram of the active hydraulic suspension fluid supply unit of the utility model, wherein: Figure 1 (a) is the hydraulic circuit schematic diagram of the active hydraulic suspension fluid supply unit. Figure 1 (b) is a schematic structural diagram of the integrated liquid supply unit of the present invention;

[0054] Figure 2 This is a schematic diagram of the oil direction when the target moving speed type is the target descending speed in the active control mode of an embodiment of the present utility model;

[0055] Figure 3 This is a schematic diagram of the oil direction when the target moving speed type is the target rising speed in the active control mode of an embodiment of the present utility model;

[0056] Figure 4 Schematic diagram of the oil direction in the semi-active continuous damping control mode in the embodiment of the present invention;

[0057] Figure 5 Schematic diagram of the oil direction in the passive damping control mode in an embodiment of the present invention;

[0058] Figure 6 This is a schematic diagram of pressure relief according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0059] like Figure 1As shown, an active hydraulic suspension fluid supply unit includes an integrated fluid supply unit, which is provided with a first fluid supply port 26 and a second fluid supply port 27, which are used to respectively connect the two oil ports of the hydraulic shock absorber. The integrated fluid supply unit includes a first solenoid valve 4, a second solenoid valve 5, a third solenoid valve 6, a fourth solenoid valve 7, and a one-way pump 2. The one-way pump 2 is powered by a one-way motor 1. The first oil delivery ends of the first solenoid valve 4 and the third solenoid valve 6 are both connected to the second fluid supply port 27 of the active hydraulic suspension fluid supply unit, the first oil delivery ends of the second solenoid valve 5 and the fourth solenoid valve 7 are both connected to the first fluid supply port 26 of the active hydraulic suspension fluid supply unit, the second oil delivery ends of the third solenoid valve 6 and the fourth solenoid valve 7 are connected to the oil outlet end of the one-way pump 2, and the second oil delivery ends of the first solenoid valve 4 and the second solenoid valve 5 are connected to the oil inlet end of the one-way pump 2.

[0060] This type of fluid supply system not only simplifies the oil circuit structure and reduces the oil flow path within the system, but also enables rapid switching of the oil circuit's flow state through the coordinated operation of the various solenoid valves, thus addressing most operating conditions requiring rapid direction changes. Furthermore, the system cleverly utilizes the first, second, third, and fourth solenoid valves (4, 5, 6, and 7) to isolate the hydraulic pump from the shock absorber. These solenoid valves act to mitigate oil shock and protect the one-way pump (2). This prevents the sudden compression of the oil within the hydraulic shock absorber from impacting the one-way pump (2) during significant vehicle impacts.

[0061] To enable the present invention to have a faster response speed and be more flexible in its installation within the suspension system, thereby reducing the space occupied by the hydraulic system, a valve block 3 may also be provided, into which four two-position, two-way solenoid valves, namely, a first solenoid valve 4, a second solenoid valve 5, a third solenoid valve 6, and a fourth solenoid valve 7, are integrated (the valve block 3 in this embodiment measures 80 mm × 80 mm × 40 mm). These two-position, two-way solenoid valves are all cylindrical solenoid valves with a diameter of 15 mm and a height of 25 mm. The valve core of such cylindrical solenoid valves is also very small. Combined with the oil circuit design of the present invention, the direction of the medium in the oil circuit can be quickly switched (with virtually no delay), thus addressing most operating conditions requiring rapid reversal.

[0062] In this embodiment, the lower coils of the four two-position, two-way solenoid valves—the first solenoid valve 4, the second solenoid valve 5, the third solenoid valve 6, and the fourth solenoid valve 7—are connected to a circuit board 8, while the upper ends of the solenoid valves are connected via hydraulic lines in the valve block 3. The ECU exchanges signals with the circuit board (which also has a protective housing 9 at its outer end) via a connector 10 to control the operating state of the motor and the opening and closing of the first, second, third, and fourth solenoid valves 4, 5, 6, and 7, thereby controlling the direction and flow rate of oil between the upper and lower chambers of the shock absorber.

[0063] In order to enable the utility model to adjust the stiffness, height and damping of the suspension in real time according to road conditions during vehicle driving, a continuous damping control unit is also arranged between the hydraulic shock absorber and the integrated liquid supply unit. The continuous damping control unit is provided with a first damping control port and a second damping control port, and the first damping control port and the second damping control port of the continuous damping control unit are respectively connected to the first liquid supply port 26 and the second liquid supply port 27 of the integrated liquid supply unit, so as to realize continuous damping control of the suspension.

[0064] In this embodiment, the continuous damping control unit includes a first electromagnetic proportional valve 13, a first damping valve 14, a first one-way valve 15, a second electromagnetic proportional valve 16, a second damping valve 17, a second one-way valve 18, and an accumulator 12. One ends of the first electromagnetic proportional valve 13, the first damping valve 14, the first one-way valve 15, the second electromagnetic proportional valve 16, the second damping valve 17, and the second one-way valve 18 are all connected to the accumulator 12, and the other ends of the first electromagnetic proportional valve 13, the first damping valve 14, and the first one-way valve 15 are all connected to the first damping control port of the continuous damping control unit. The other ends of the second electromagnetic proportional valve 16, the second damping valve 17, and the second one-way valve 18 are all connected to the second damping control port of the continuous damping control unit.

[0065] In this embodiment, the hydraulic shock absorber includes a shock absorber cylinder 19, a one-way valve 20, a shock absorber piston 21, a shock absorber piston rod 22, an air spring 23, a buffer block 24, and a shock absorber top mounting bushing 25. The upper and lower chambers of the hydraulic shock absorber are connected through respective damping valves, requiring only a single accumulator 12 for shock absorption, thus saving costs.

[0066] In this way, the present invention can control the suspension in different modes according to different situations. In this embodiment, the vehicle's hydraulic suspension system has three control modes: active control mode, semi-active continuous damping control mode, and passive damping control mode. The suspension vibration frequency threshold is set at 10Hz to determine the timing of entering each mode:

[0067] 1) The active control mode is as follows Figures 2 and 3 As shown in FIG, when the real-time vibration frequency of the suspension is ≤10 Hz, the active hydraulic suspension supply unit adopts the active control mode to control the suspension. The specific steps include:

[0068] 1-1) Calculating a current target moving speed of a piston of a hydraulic shock absorber using a real-time vehicle signal, wherein the target moving speed includes a target ascending speed or a target descending speed;

[0069] 1-2) Determine the type of target movement speed and control each valve in the following manner:

[0070] If the target moving speed type is the target ascending speed, the second solenoid valve 5 and the third solenoid valve 6 are opened, and the other valves are closed;

[0071] If the target moving speed type is the target descending speed, the first solenoid valve 4 and the fourth solenoid valve 7 are opened, and the other valves are closed;

[0072] 1-3) Use the motor speed-piston target movement speed characteristic curve to obtain the motor target speed, and make the motor real-time speed equal to the motor target speed;

[0073] 1-4) Repeat steps 1-1) to 1-3) with a repetition frequency equal to the real-time vibration frequency of the suspension.

[0074] The motor speed-piston target moving speed characteristic curve in this embodiment is a two-dimensional curve used to reflect the relationship between the motor speed and the shock absorber piston moving speed, and can usually be obtained from a prior calibration test.

[0075] 2) The semi-active continuous damping control mode is as follows Figure 4 As shown in the figure, when the real-time vibration frequency of the suspension is greater than 10 Hz, the active hydraulic suspension supply unit adopts a semi-active continuous damping control mode to control the suspension. The specific steps include:

[0076] 2-1) Close the one-way motor 1, the first solenoid valve 4, the second solenoid valve 5, the third solenoid valve 6, and the fourth solenoid valve 7;

[0077] 2-2) Using real-time vehicle signals, calculate the current target piston velocity of the hydraulic shock absorber and the target vertical force of the suspension.

[0078] 2-3) Based on the target piston movement speed and the target suspension vertical force obtained in step 2-2), the shock absorber damping characteristic curve is consulted to obtain the current target openings of the first solenoid proportional valve 13 and the second solenoid proportional valve 16, and the real-time openings of the first solenoid proportional valve 13 and the second solenoid proportional valve 16 are set equal to the current target openings;

[0079] It is worth noting that the shock absorber damping characteristic curve is actually a two-dimensional plane coordinate system with multiple relationship curves between the vertical force of the suspension and the piston movement speed. Each relationship curve corresponds to an opening of the electromagnetic proportional valve. This shock absorber damping characteristic curve is obtained through prior calibration experiments.

[0080] 2-4) Repeat steps 2-2) to 2-3) until the real-time vibration frequency of the suspension is no longer greater than the suspension vibration frequency threshold of 10 Hz.

[0081] 3) The passive damping control mode is as follows Figure 5 As shown, when the active control mode and the semi-active continuous damping control mode fail, the unidirectional motor 1, as well as the first solenoid valve 4, the second solenoid valve 5, the third solenoid valve 6, the fourth solenoid valve 7, the first solenoid proportional valve 13, and the second solenoid proportional valve 16 are closed, so that the active hydraulic suspension fluid supply unit adopts the passive damping control mode to control the suspension.

[0082] In this embodiment, in order to ensure the normal and stable operation of the hydraulic system, a pressure-limiting safety valve 11 is further provided in the valve block, and the oil inlet end of the pressure-limiting safety valve is connected to the oil outlet end of the one-way pump, and the oil outlet end of the pressure-limiting safety valve is connected to the oil inlet end of the one-way pump. When an abnormality occurs in the vehicle hydraulic suspension system, the internal pressure of the hydraulic circuit where the one-way pump 2 is located rises rapidly and is greater than the set value, the pressure-limiting safety valve 11 opens, and part of the oil of the one-way pump 2 flows from the oil outlet end of the one-way pump 2 to the oil inlet end of the pressure-limiting safety valve 11, and then flows from the oil outlet end of the pressure-limiting safety valve 11 to the oil inlet end of the one-way pump 2, forming a pipeline pressure relief circuit to reduce the excessive oil pressure in the pipeline and prevent the excessive oil pressure from causing impact on the hydraulic pump, such as Figure 6 shown.

[0083] Comparative experiments have demonstrated that the present invention, while ensuring smooth vehicle travel under varying road conditions, expands the selection of hydraulic suspension components and reduces the cost of the integrated hydraulic suspension unit. For example, the overall cost of a suspension fluid supply system using a bidirectional motor (including the motor, hydraulic pump, and circuit board) typically ranges from 2,000 to 3,000 yuan, while the overall cost of a suspension fluid supply system using a unidirectional motor (including the motor, hydraulic pump, and circuit board) typically ranges from 1,500 to 2,000 yuan. However, the structural design of the present invention reduces the overall cost of the suspension fluid supply system (motor, hydraulic pump, and circuit board) to just 800 to 1,200 yuan, significantly expanding the development and application potential of automotive suspension hydraulic control systems.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the scope of protection of the present invention.

Claims

1. An active hydraulic suspension fluid supply unit, characterized in that: The invention comprises an integrated liquid supply unit, which is provided with a first liquid supply port (26) and a second liquid supply port (27) for respectively connecting the two oil ports of the hydraulic shock absorber. The integrated liquid supply unit comprises a first solenoid valve (4), a second solenoid valve (5), a third solenoid valve (6), a fourth solenoid valve (7), and a one-way pump (2). The one-way pump (2) is powered by a one-way motor (1). The first oil supply ends of the first solenoid valve (4) and the third solenoid valve (6) are both connected to the second liquid supply port (27) of the active hydraulic suspension liquid supply unit. The first oil supply ends of the second solenoid valve (5) and the fourth solenoid valve (7) are both connected to the first liquid supply port (26) of the active hydraulic suspension liquid supply unit. The second oil supply ends of the third solenoid valve (6) and the fourth solenoid valve (7) are connected to the oil outlet end of the one-way pump (2). The second oil supply ends of the first solenoid valve (4) and the second solenoid valve (5) are connected to the oil inlet end of the one-way pump (2).

2. The active hydraulic suspension fluid supply unit according to claim 1, characterized in that: It also includes a valve block (3) having a size of 80 mm×80 mm×40 mm, and the first solenoid valve (4), the second solenoid valve (5), the third solenoid valve (6), and the fourth solenoid valve (7) are integrated into the valve block.

3. The active hydraulic suspension fluid supply unit according to claim 2, characterized in that: The valve block (3) is further provided with a pressure-limiting safety valve (11), the oil inlet end of the pressure-limiting safety valve (11) being in communication with the oil outlet end of the one-way pump (2), and the oil outlet end of the pressure-limiting safety valve (11) being in communication with the oil inlet end of the one-way pump (2).

4. An active hydraulic suspension fluid supply unit according to claim 1 or 2, characterized in that: The first solenoid valve (4), the second solenoid valve (5), the third solenoid valve (6), and the fourth solenoid valve (7) are all two-position, two-way solenoid valves.

5. The active hydraulic suspension fluid supply unit according to claim 1, characterized in that: The invention also includes a continuous damping control unit, which is provided with a first damping control port and a second damping control port. The continuous damping control unit is arranged between the hydraulic shock absorber and the integrated liquid supply unit, so that the first damping control port and the second damping control port of the continuous damping control unit are respectively connected to the first liquid supply port (26) and the second liquid supply port (27) of the integrated liquid supply unit, so as to realize continuous damping control of the suspension.

6. The active hydraulic suspension fluid supply unit according to claim 5, characterized in that: The continuous damping control unit comprises a first electromagnetic proportional valve (13), a first damping valve (14), a first one-way valve (15), a second electromagnetic proportional valve (16), a second damping valve (17), a second one-way valve (18), and an accumulator (12), wherein one end of the first electromagnetic proportional valve (13), the first damping valve (14), the first one-way valve (15), the second electromagnetic proportional valve (16), the second damping valve (17), and the second one-way valve (18) are all communicated with the accumulator (12), the other end of the first electromagnetic proportional valve (13), the first damping valve (14), and the first one-way valve (15) are all communicated with a first damping control port of the continuous damping control unit, and the other end of the second electromagnetic proportional valve (16), the second damping valve (17), and the second one-way valve (18) are all communicated with a second damping control port of the continuous damping control unit.

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