Vehicle chassis hydraulic suspension system and control method thereof

Abstract

The present application belongs to the technical field of vehicle chassis, and discloses a vehicle chassis hydraulic suspension system. One end of a main oil path is connected to a recovery cavity of a shock absorber cylinder, and the other end of the main oil path is connected to a compression cavity of the shock absorber cylinder. The main oil path is connected to an energy accumulator. An oil pump oil path is connected to the main oil path, and an oil pump is connected to the oil pump oil path. An upper one-way valve and an upper electromagnetic valve are installed on the main oil path between a combination point of the main oil path and the oil pump oil path and a combination point of the energy accumulator and the main oil path. A lower one-way valve and a lower electromagnetic valve are installed on the main oil path between another combination point of the main oil path and the oil pump oil path and another combination point of the energy accumulator and the main oil path. The vehicle chassis hydraulic suspension system realizes smooth switching between semi-active and active modes and complete independence of oil paths, reduces system redundancy, reduces space occupation and manufacturing cost, improves system working condition adaptability, integration and working reliability, and prolongs service life.

Description

Technical Field

[0001] This invention belongs to the field of vehicle chassis technology, and more specifically, relates to a vehicle chassis hydraulic suspension system. This invention also relates to a control method for a vehicle chassis hydraulic suspension system. Background Technology

[0002] As a core component of the vehicle chassis, the hydraulic suspension system primarily transmits the forces and torques between the wheels and the vehicle body, buffers the impact from uneven road surfaces, and dampens body vibrations, thereby ensuring the smoothness, stability, and ride comfort of the vehicle. It is widely used in passenger cars, commercial vehicles, and special-purpose vehicles. With the automotive industry moving towards intelligent and high-performance systems, traditional passive hydraulic suspensions are no longer sufficient to meet the dynamic adjustment needs under complex road conditions. Active hydraulic suspension systems, because they can adjust damping and stiffness in real time according to road conditions and vehicle posture, have become a key area of ​​research and application in the industry.

[0003] Currently, most existing active hydraulic suspension systems employ multi-accumulator configurations, resulting in complex structures and high costs. Furthermore, the fixed arrangement of the accumulators and oil pumps makes it difficult to adapt to the layout requirements of different vehicles and personalized customer needs. The hydraulic pump connection method is also limited, failing to balance the independence of semi-active and active modes and the flexibility of mode switching. Simultaneously, the fixed structure of the accumulators cannot be flexibly selected according to different operating conditions, and the structural design of the shock absorber guide components suffers from insufficient sealing performance and low guiding accuracy, thus limiting the adaptability, reliability, and service life of the active hydraulic suspension system. Specifically, the shortcomings of existing technologies are as follows: 1. Insufficient independence of mode switching and hydraulic circuit: In existing switchable suspension systems, the hydraulic circuit structure often shares pipelines or valves during the switching between semi-active and active modes. This results in the hydraulic circuits not being completely independent between the two operating modes, potentially causing pressure fluctuations and vehicle vibrations during mode switching, affecting the smoothness of the transition. Simultaneously, the hydraulic circuit pressure recovery time after mode switching is relatively long, affecting the system's response speed. 2. Redundant accumulator configuration and large space occupation: Existing active hydraulic suspension systems often require multiple accumulators, such as independent accumulators for high-pressure and low-pressure circuits respectively, or independent accumulator units for the front and rear suspensions. This multi-accumulator configuration increases system complexity and manufacturing costs, and also occupies a significant amount of chassis space, hindering the lightweight and compact design of the entire vehicle. 3. Limited and inflexible oil pump connection method: In existing systems, the oil pump is typically connected to the hydraulic circuit through a fixed, single path, lacking alternative connection options. This fixed connection method limits the system's adaptability under different operating conditions. For example, in scenarios requiring only semi-active operation, the oil pump still participates in the loop circulation, causing unnecessary energy consumption. Furthermore, in scenarios requiring manual intervention or emergency switching, the system lacks convenient operating methods. 4. Rigid component layout and low integration: In existing hydraulic suspension systems, accumulators, oil pumps, and other components are typically distributed as independent parts throughout the vehicle body, connected by long hydraulic lines. This distributed layout not only increases pipeline length and leakage risk but also constrains the overall vehicle space layout, making it difficult to adapt to the personalized layout requirements of different vehicle models and customers.

[0004] Existing technology includes a patent titled "A Hydraulic Suspension System, Control Method, Storage Medium, and Vehicle," with publication number "118927887A." This technology provides a hydraulic suspension system, control method, storage medium, and vehicle, belonging to the field of vehicle technology. The hydraulic suspension system includes: a lifting hydraulic cylinder, comprising a hydraulic chamber; and a first valve connected to both the hydraulic chamber and the fuel pump, configured to open in response to a chassis height increase signal. When open, the first valve connects the pipeline between the hydraulic chamber and the fuel pump, allowing fuel drawn from the fuel tank by the fuel pump to enter the hydraulic chamber. The fuel pump is configured to draw fuel from the fuel tank based on power provided by the power source. This application, by connecting the lifting hydraulic cylinder to the fuel pump, allows the lifting hydraulic cylinder to share the same pump body with the fuel supply system, reducing the number of pump bodies and thus lowering the difficulty of vehicle structural layout design and manufacturing costs. This achieves the technical effect of reducing the cost required to implement chassis height adjustment functionality in vehicles.

[0005] However, this technology does not address the technical issues and solutions of this application. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a vehicle chassis hydraulic suspension system that optimizes the oil circuit structure design, simplifies the accumulator configuration, provides diversified oil pump access schemes, and improves the flexibility of component layout. This enables smooth switching between semi-active and active modes and complete oil circuit independence, reduces system redundancy, lowers space occupation and manufacturing costs, improves system adaptability, integration and reliability, and extends service life. At the same time, it takes into account the requirements of vehicle lightweighting and compactness as well as the personalized layout requirements of different models and customers, ultimately improving vehicle ride comfort and handling stability, and enhancing the driving experience.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention relates to a vehicle chassis hydraulic suspension system. As an example 1, one end of the main oil circuit is connected to the recovery chamber of the shock absorber cylinder, and the other end of the main oil circuit is connected to the compression chamber of the shock absorber cylinder. The main oil circuit is connected to an accumulator, and the main oil circuit is connected to an oil pump circuit. The oil pump circuit is connected to an oil pump. An upper check valve and an upper solenoid valve are installed on the main oil circuit between one connection point of the main oil circuit and the oil pump circuit and one connection point of the accumulator and the main oil circuit. A lower check valve and a lower solenoid valve are installed on the main oil circuit between another connection point of the main oil circuit and the oil pump circuit and another connection point of the accumulator and the main oil circuit.

[0008] As in Embodiment 2, one end of the main oil circuit is connected to the recovery chamber of the shock absorber cylinder, and the other end of the main oil circuit is connected to the compression chamber of the shock absorber cylinder. The main oil circuit is connected to the accumulator, and the main oil circuit is connected to the oil pump circuit. The oil pump circuit is connected to the oil pump. An upper check valve and an upper solenoid valve are installed on the main oil circuit between one connection point of the main oil circuit and the oil pump circuit and one connection point of the accumulator and the main oil circuit. A lower check valve and a lower solenoid valve are installed on the main oil circuit between another connection point of the main oil circuit and the oil pump circuit and another connection point of the accumulator and the main oil circuit. The oil pump circuit between one connection point of the oil pump circuit and the main oil circuit and the oil pump is the upper section of the oil pump circuit, and the oil pump circuit between the other connection point of the oil pump circuit and the main oil circuit and the oil pump is the lower section of the oil pump circuit. An upper switch valve is provided in the upper section of the oil pump circuit, and a lower switch valve is provided in the lower section of the oil pump circuit.

[0009] As an embodiment 3, the present invention also relates to a vehicle chassis hydraulic suspension system, wherein one end of the main oil circuit is connected to the recovery chamber of the shock absorber cylinder, the other end of the main oil circuit is connected to the compression chamber of the shock absorber cylinder, the main oil circuit is connected to an accumulator, the main oil circuit is connected to an oil pump circuit, the oil pump circuit is connected to an oil pump, an upper solenoid valve is installed on the main oil circuit between one connection point of the main oil circuit and the oil pump circuit and one connection point of the accumulator and the main oil circuit, and another connection point of the main oil circuit and the oil pump circuit and another connection point of the accumulator and the main oil circuit is... A lower solenoid valve is installed on the main oil line. An accumulator oil line is set between the upper and lower sections of the oil pump oil line. The accumulator oil line is connected to the accumulator. The oil pump oil line between one connection point of the oil pump oil line and the main oil line and the oil pump is the upper section of the oil pump oil line. An upper check valve is installed on the branch line between the upper section of the oil pump oil line and the accumulator. The oil pump oil line between the other connection point of the oil pump oil line and the main oil line and the oil pump is the lower section of the oil pump oil line. A lower check valve is installed on the branch line between the lower section of the oil pump oil line and the accumulator.

[0010] The damper body includes a damper cylinder, a piston is installed inside the damper cylinder, the piston divides the damper cylinder into a recovery chamber and a compression chamber, a piston rod is connected to the piston, and the piston rod extends through the recovery chamber to the outside of the damper cylinder.

[0011] As an example 1, the control method of the vehicle chassis hydraulic suspension system includes a semi-active mode and an active mode. In semi-active mode, the oil pump does not operate; however, in the free state, the oil pump's internal components are propelled by the oil, creating a channel that can lead to leakage and prevent the main oil circuit from adjusting damping. To avoid this problem, the system controls the oil pump motor to 0 speed in semi-active mode to "close the oil pump channel," allowing damping force to be adjusted solely by changing the solenoid valve opening.

[0012] During the compression stroke, the wheel jumps upward, the piston moves downward, the piston rod retracts, and the piston 1.2 squeezes downward, the volume of the compression chamber decreases and the oil pressure increases, the volume of the recovery chamber increases and the oil pressure decreases; The oil flow direction is: compression chamber → lower solenoid valve → accumulator → upper solenoid valve / upper check valve 4.1 → recovery chamber; During the recovery stroke, the wheel falls, the piston moves upward, the piston rod extends, the piston is stretched upward, the volume of the recovery chamber decreases and the oil pressure increases; the volume of the compression chamber increases and the oil pressure decreases. The oil flow direction is: recovery chamber → upper solenoid valve → accumulator → lower check valve / lower solenoid valve → compression chamber.

[0013] In Example 1, in active mode, the oil pump operates. Active compression stroke working process: The motor drives the oil pump to pump oil in the forward direction → into the recovery chamber, the oil pressure in the recovery chamber actively increases; at the same time, the oil circuit on the lower side connects to the low-pressure return oil path, the pressure in the compression chamber is reduced by pressure relief; an active pressure difference is formed between the upper chamber with high pressure and the lower chamber with low pressure, which pushes the piston to actively compress downward, and the piston rod is actively pulled down; Active recovery stroke working process: The motor drives the oil pump to pump oil in reverse → into the compression chamber, and the oil pressure in the chamber actively increases; at the same time, the oil circuit on the upper side is connected to the low-pressure return oil path, the pressure in the recovery chamber is reduced by pressure relief, and an active pressure difference is formed between the lower chamber with high pressure and the upper chamber with low pressure, which pushes the piston to actively extend upward.

[0014] In Example 2, In semi-active mode, In semi-active mode, the upper and lower switching valves are closed, the oil pump is disconnected from the main oil circuit, and the oil pump is isolated from the system. The system relies on the piston movement of the damper to squeeze the oil to generate a pressure difference. The oil circuit throttling damping is adjusted by adjusting the opening of the solenoid valve. There is no external active hydraulic power input, only vibration energy is consumed and passive vibration is reduced.

[0015] During the compression stroke, the wheel bounces upward, the piston moves downward, the piston rod retracts, and the piston squeezes downward, reducing the volume of the compression chamber and increasing the oil pressure; the volume of the recovery chamber increases and the oil pressure decreases. The oil flow direction is: compression chamber → lower solenoid valve → accumulator → upper solenoid valve / upper check valve → recovery chamber; During the recovery stroke, the wheel falls, the piston moves upward, the piston rod extends, the piston is stretched upward, the volume of the recovery chamber decreases and the oil pressure increases; the volume of the compression chamber increases and the oil pressure decreases. The oil flow direction is: recovery chamber → upper solenoid valve → accumulator → lower check valve / lower solenoid valve → compression chamber.

[0016] In Example 2, in active mode, When the upper and lower switching valves are open, the high-pressure oil is connected to the oil pump through the switching valves and works in coordination with the accumulator in active mode. At this time, the system no longer relies on piston movement to generate pressure difference. The oil pump actively pumps oil and actively controls the pressure difference between the upper and lower chambers. It can actively drive piston movement, actively offset road impacts, and actively adjust the vehicle body posture and height, thus achieving fully active hydraulic control.

[0017] Active compression stroke working process: The motor drives the oil pump to pump oil in the forward direction → the upper switch valve is energized and fully opened, conducting high-pressure oil → the oil pressure in the recovery chamber actively increases; at the same time, the lower oil circuit is connected to the low-pressure return oil path, and the pressure in the compression chamber is reduced by pressure relief; an active pressure difference is formed between the upper chamber with high pressure and the lower chamber with low pressure, which pushes the piston to actively compress downward, and the piston rod is actively pulled down; Active recovery stroke working process: The motor drives the oil pump to pump oil in reverse → the lower switch valve is energized and fully opened, conducting high-pressure oil → the oil pressure in the compression chamber actively increases; at the same time, the upper oil circuit is connected to the low-pressure return oil path, the pressure in the recovery chamber is reduced by pressure relief, and an active pressure difference is formed between the lower chamber high pressure and the upper chamber low pressure, which pushes the piston to actively extend upward.

[0018] As an example 3, the control method of the vehicle chassis hydraulic suspension system includes a semi-active mode and an active mode. In semi-active mode, oil pump 2 does not work, there is no active oil pumping, the oil pump does not work, and the system relies entirely on the chamber pressure difference generated by the movement of the damper piston to drive the oil flow.

[0019] During the compression stroke, the wheel bounces upward, the piston moves downward, the piston rod retracts, and the piston squeezes downward, reducing the volume of the compression chamber and increasing the oil pressure; the volume of the recovery chamber increases and the oil pressure decreases. The oil flow direction is: compression chamber → lower solenoid valve → accumulator / upper check valve / upper solenoid valve → recovery chamber; During the recovery stroke, the wheel falls, the piston moves upward, the piston rod extends, the piston is stretched upward, the volume of the recovery chamber decreases and the oil pressure increases; the volume of the compression chamber increases and the oil pressure decreases. The oil flow direction is: recovery chamber → upper solenoid valve → accumulator / lower check valve / lower solenoid valve → compression chamber.

[0020] In Example 3, in active mode, the oil pump operates, actively supplying oil and outputting controllable force. Similar to the previous description, it drives the bidirectional oil pump in forward / reverse rotation, actively pumping oil into the upper and lower chambers of the shock absorber to establish a controllable pressure difference, directly driving the piston movement.

[0021] Active compression stroke working process: The upper solenoid valve is closed and the lower solenoid valve is open. The motor drives the oil pump to pump oil in the forward direction → upper check valve → enters the recovery chamber, and the oil pressure in the chamber actively increases; at the same time, the lower oil circuit is connected to the low-pressure return oil path, the pressure in the compression chamber is reduced by pressure relief, and an active pressure difference is formed between the upper chamber with high pressure and the lower chamber with low pressure, which pushes the piston to actively compress downward and the piston rod to actively pull down. Active recovery stroke working process: The upper solenoid valve opens and the lower solenoid valve closes. The motor drives the oil pump to pump oil in reverse → lower check valve → into the compression chamber, and the chamber oil pressure actively increases; at the same time, the upper oil circuit connects to the low-pressure return oil path, the pressure in the recovery chamber is reduced by pressure relief, and an active pressure difference is formed between the lower chamber high pressure and the upper chamber low pressure, which pushes the piston to actively extend upward.

[0022] The working principle and beneficial effects of the technical solution adopted in this invention are as follows: The vehicle chassis hydraulic suspension system described in this invention offers the following advantages: 1. Simplified structure and reduced cost: It adopts a single accumulator design, replacing the existing multi-accumulator structure, reducing the number of parts, simplifying the system structure, and lowering procurement, assembly, and maintenance costs. Both hydraulic circuit schemes employ simple pipeline designs, significantly reducing the failure rate and facilitating maintenance. 2. Flexible and convenient mode switching: It provides three hydraulic circuit schemes. Scheme 1 enables the active mode of the suspension system, switching between semi-active and active modes by controlling the oil pump speed. Scheme 2 allows for autonomous switching of operating modes, achieving complete decoupling of the two modes, and the number of switching valves can be flexibly configured. Scheme 3 enables automatic switching between semi-active and active modes without manual intervention, providing rapid response. It adapts to different user needs and driving conditions, solving the problem of inflexible mode switching in existing systems. 3. Strong installation adaptability: The accumulator and hydraulic pump can be independent or integrated into the shock absorber body. The installation method can be flexibly selected according to the vehicle chassis layout space and customer needs, greatly improving the system's adaptability to different vehicle models and expanding its application range. 4. Wide range of applications: The accumulator can be modified into piston or bag type, which can be flexibly selected according to the vehicle load requirements, vibration frequency, installation space and other scenarios. It takes into account the system's pressure stability, response speed and installation convenience, and is suitable for different application scenarios such as passenger cars, commercial vehicles and special vehicles. Attached Figure Description

[0023] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein: Figure 1 This is a schematic diagram of the structure of the vehicle chassis hydraulic suspension system described in this invention; Figure 2 This is a schematic diagram of the structure of the vehicle chassis hydraulic suspension system described in this invention; Figure 3 This is a schematic diagram of the structure of the vehicle chassis hydraulic suspension system described in this invention; The components in the attached diagram are labeled as follows: A, main oil circuit; B, oil pump oil circuit; C, accumulator oil circuit; 1, damper body; 1.1, damper cylinder; 1.2, piston; 1.3, recovery chamber; 1.4, compression chamber; 2, oil pump; 3.1, upper solenoid valve; 3.2, lower solenoid valve; 4.1, upper check valve; 4.2, lower check valve; 5, accumulator; 6.1, upper switching valve; 6.2, lower switching valve; 7, oil pump motor. Detailed Implementation

[0024] The following description, with reference to the accompanying drawings, provides a more detailed explanation of the specific embodiments of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the functions and working principles of each part: As attached Figure 1As shown, the present invention is a vehicle chassis hydraulic suspension system. As an embodiment 1, one end of the main oil circuit A is connected to the recovery chamber 1.3 of the shock absorber cylinder 1.1, and the other end of the main oil circuit A is connected to the compression chamber 1.4 of the shock absorber cylinder 1.1. The main oil circuit A is connected to the accumulator 5. The main oil circuit A is connected to the oil pump circuit B, and the oil pump circuit B is connected to the oil pump 2. An upper check valve 4.1 and an upper solenoid valve 3.1 are installed on the main oil circuit A between one connection point of the main oil circuit A and the oil pump circuit B and one connection point of the accumulator 5 and the main oil circuit A. A lower check valve 4.2 and a lower solenoid valve 3.2 are installed on the main oil circuit A between another connection point of the main oil circuit A and the oil pump circuit B and another connection point of the accumulator 5 and the main oil circuit A.

[0025] As attached Figure 2 As shown in Example 2, one end of the main oil circuit A is connected to the recovery chamber 1.3 of the shock absorber cylinder 1.1, and the other end of the main oil circuit A is connected to the compression chamber 1.4 of the shock absorber cylinder 1.1. The main oil circuit A is connected to the accumulator 5, and the main oil circuit A is connected to the oil pump circuit B. The oil pump circuit B is connected to the oil pump 2. An upper check valve 4.1 and an upper solenoid valve 3.1 are installed on the main oil circuit A between a junction of the main oil circuit A and the oil pump circuit B and a junction of the accumulator 5 and the main oil circuit A. The main oil circuit A and the oil pump circuit B... A lower check valve 4.2 and a lower solenoid valve 3.2 are installed on the main oil circuit A between another connection point and the accumulator 5 and another connection point of the main oil circuit A. The oil pump circuit B between the oil pump circuit B and one connection point of the main oil circuit A and the oil pump 2 is the upper section B1 of the oil pump circuit. The oil pump circuit B between the oil pump circuit B and the other connection point of the main oil circuit A and the oil pump 2 is the lower section B2 of the oil pump circuit. An upper switch valve 6.1 is installed on the upper section B1 of the oil pump circuit, and a lower switch valve 6.2 is installed on the lower section B2 of the oil pump circuit.

[0026] As attached Figure 3As shown in Embodiment 3, the present invention also relates to a vehicle chassis hydraulic suspension system. One end of the main oil circuit A is connected to the recovery chamber 1.3 of the shock absorber cylinder 1.1, and the other end of the main oil circuit A is connected to the compression chamber 1.4 of the shock absorber cylinder 1.1. The main oil circuit A is connected to the accumulator 5. The main oil circuit A is connected to the oil pump circuit B, and the oil pump circuit B is connected to the oil pump 2. An upper solenoid valve 3.1 is installed on the main oil circuit A between one connection point of the main oil circuit A and the oil pump circuit B and one connection point of the accumulator 5 and the main oil circuit A. Another connection point of the main oil circuit A and the oil pump circuit B is connected to the other connection point of the accumulator 5 and the main oil circuit A. A lower solenoid valve 3.2 is installed on the main oil circuit A. An accumulator oil circuit C is set between the upper section B1 and the lower section B2 of the oil pump oil circuit B. The accumulator oil circuit C is connected to the accumulator 5. The oil pump oil circuit B between one connection point of the oil pump oil circuit B and the main oil circuit A and the oil pump 2 is the upper section B1 of the oil pump oil circuit. An upper check valve 4.1 is set on the branch between the upper section B1 of the oil pump oil circuit B and the accumulator 5. The oil pump oil circuit B between the other connection point of the oil pump oil circuit B and the main oil circuit A and the oil pump 2 is the lower section B2 of the oil pump oil circuit. A lower check valve 4.2 is set on the branch between the lower section B2 of the oil pump oil circuit B and the accumulator 5.

[0027] The vehicle chassis hydraulic suspension system described in this invention achieves smooth switching between semi-active and active modes and complete oil circuit independence by optimizing the oil circuit structure design, simplifying the accumulator configuration, providing diversified oil pump access schemes, improving the flexibility of component layout, and optimizing the shock absorber guide sealing structure. This reduces system redundancy, lowers space occupation and manufacturing costs, improves system adaptability, integration and operational reliability, and extends service life. At the same time, it takes into account the requirements of vehicle lightweighting and compactness as well as the personalized layout requirements of different models and customers, ultimately improving vehicle ride comfort and handling stability, and enhancing the driving experience.

[0028] The damper body 1 includes a damper cylinder 1.1, a piston 1.2 is disposed inside the damper cylinder 1.1, the piston 1.2 divides the damper cylinder 1.1 into a recovery chamber 1.3 and a compression chamber 1.4, and a piston rod 1.5 is connected to the piston 1.2, and the piston rod 1.5 extends through the recovery chamber 1.3 to the outside of the damper cylinder 1.1.

[0029] As an example 1, the control method of the vehicle chassis hydraulic suspension system includes a semi-active mode and an active mode. In semi-active mode, oil pump 2 does not work; however, in the free state, the oil pump's internal components are pushed by the oil, forming a channel, which in turn causes leakage, preventing the main oil circuit from adjusting the damping. To avoid this problem, in semi-active mode, the oil pump motor needs to be controlled at 0 speed to achieve the purpose of "closing the oil pump channel," so that the damping force can be adjusted solely by adjusting the opening of the solenoid valve.

[0030] During the compression stroke, the wheel jumps upward, piston 1.2 moves downward, piston rod 1.5 retracts, piston 1.2 squeezes downward, the volume of compression chamber 1.4 decreases and the oil pressure increases, the volume of recovery chamber 1.3 increases and the oil pressure decreases; The oil flow direction is: compression chamber 1.4 → lower solenoid valve 3.2 → accumulator 5 → upper solenoid valve 3.1 / upper check valve 4.1 → recovery chamber 1.3; During the recovery stroke, the wheel falls, piston 1.2 moves upward, piston rod 1.5 extends, piston 1.2 is stretched upward, the volume of the recovery chamber 1.3 decreases and the oil pressure increases; the volume of the compression chamber 1.4 increases and the oil pressure decreases. The oil flow direction is: restoration chamber 1.3 → upper solenoid valve 3.1 → accumulator 5 → lower check valve 4.2 / lower solenoid valve 3.2 → compression chamber 1.4.

[0031] In Example 1, in active mode, oil pump 2 operates. Active compression stroke working process: The motor drives the oil pump 2 to pump oil in the forward direction → into the recovery chamber 1.3, and the oil pressure in the recovery chamber 1.3 actively increases; at the same time, the oil circuit on the lower side connects to the low-pressure return oil path, and the pressure in the compression chamber 1.4 is reduced by pressure relief; an active pressure difference is formed between the upper chamber with high pressure and the lower chamber with low pressure, which pushes the piston 1.2 to actively compress downward, and the piston rod 1.5 to actively pull down; Active recovery stroke working process: The motor drives the oil pump 2 to pump oil in reverse → into the compression chamber 1.4, and the oil pressure in the chamber actively increases; at the same time, the upper oil circuit is connected to the low-pressure return oil path, the pressure in the recovery chamber 1.3 is reduced by pressure relief, and an active pressure difference is formed between the lower chamber with high pressure and the upper chamber with low pressure, which pushes the piston 1.2 to actively extend upward.

[0032] In Example 2, In semi-active mode, In semi-active mode, the upper switch valve 6.1 and the lower switch valve 6.2 are closed, the oil pump 2 is disconnected from the main oil circuit A, and the oil pump is isolated from the system. The system relies on the piston movement of the damper to squeeze the oil to generate a pressure difference. The oil circuit throttling damping is adjusted by adjusting the opening of the solenoid valve 3. There is no external active hydraulic power input, only vibration energy is consumed and passive vibration is reduced.

[0033] During the compression stroke, the wheel bounces upward, piston 1.2 moves downward, piston rod 1.5 retracts, piston 1.2 squeezes downward, the volume of compression chamber 1.4 decreases and the oil pressure increases; the volume of recovery chamber 1.3 increases and the oil pressure decreases. The oil flow direction is: compression chamber 1.4 → lower solenoid valve 3.2 → accumulator 5 → upper solenoid valve 3.1 / upper check valve 4.1 → recovery chamber 1.3; During the recovery stroke, the wheel falls, piston 1.2 moves upward, piston rod 1.5 extends, piston 1.2 is stretched upward, the volume of the recovery chamber 1.3 decreases and the oil pressure increases; the volume of the compression chamber 1.4 increases and the oil pressure decreases. The oil flow direction is: restoration chamber 1.3 → upper solenoid valve 3.1 → accumulator 5 → lower check valve 4.2 / lower solenoid valve 3.2 → compression chamber 1.4.

[0034] In Example 2, in active mode, the upper switch valve 6.1 and the lower switch valve 6.2 are open, and the high-pressure oil is connected to the oil pump 2 through the switch valves, working in coordination with the accumulator 5 in active mode. The system no longer relies on piston movement to generate pressure difference. The oil pump actively pumps oil and actively controls the pressure difference between the upper and lower chambers. It can actively drive piston movement, actively offset road impacts, and actively adjust the vehicle body posture and height, thus fully realizing fully active hydraulic control.

[0035] Active compression stroke working process: The motor drives the oil pump 2 to pump oil in the forward direction → the upper switch valve 6.1 is energized and fully opened, conducting high-pressure oil → the oil pressure in the recovery chamber 1.3 actively increases; at the same time, the lower oil circuit connects to the low-pressure return oil path, and the pressure in the compression chamber 1.4 is reduced by pressure relief; an active pressure difference is formed between the upper chamber with high pressure and the lower chamber with low pressure, which pushes the piston 1.2 to actively compress downward, and the piston rod 1.5 to actively pull down; Active recovery stroke working process: The motor drives the oil pump 2 to pump oil in reverse → the lower switch valve 6.2 is energized and fully opened, conducting high-pressure oil → the oil pressure in the compression chamber 1.4 actively increases; at the same time, the upper oil circuit is connected to the low-pressure return oil path, the pressure in the recovery chamber 1.3 is reduced by pressure relief, and an active pressure difference is formed between the lower chamber high pressure and the upper chamber low pressure, which pushes the piston 1.2 to actively extend upward.

[0036] As an example 3, the control method of the vehicle chassis hydraulic suspension system includes a semi-active mode and an active mode. In semi-active mode, oil pump 2 does not work, there is no active oil pumping, the oil pump does not work, and the system relies entirely on the chamber pressure difference generated by the movement of the damper piston to drive the oil flow.

[0037] During the compression stroke, the wheel jumps upward, piston 1.2 moves downward, piston rod 1.5 retracts, piston 1.2 squeezes downward, the volume of compression chamber 1.4 decreases and the oil pressure increases; the volume of recovery chamber 1.3 increases and the oil pressure decreases. The oil flow direction is: compression chamber 1.4 → lower solenoid valve 3.2 → accumulator 5 / upper check valve 4.1 / upper solenoid valve 3.1 → recovery chamber 1.3; During the recovery stroke, the wheel falls, piston 1.2 moves upward, piston rod 1.5 extends, piston 1.2 is stretched upward, the volume of the recovery chamber 1.3 decreases and the oil pressure increases; the volume of the compression chamber 1.4 increases and the oil pressure decreases. The oil flow direction is: restoration chamber 1.3 → upper solenoid valve 3.1 → accumulator 5 / lower check valve 4.2 / lower solenoid valve 3.2 → compression chamber 1.4.

[0038] In Example 3, in active mode, oil pump 2 operates, actively supplying oil and outputting controllable force. Similar to the previous description, it drives the bidirectional oil pump in forward / reverse rotation, actively pumping oil into the upper and lower chambers of the shock absorber to establish a controllable pressure difference, directly driving the piston movement.

[0039] Active compression stroke working process: The upper solenoid valve 3.1 is closed and the lower solenoid valve 3.2 is opened. The motor drives the oil pump 2 to pump oil in the forward direction → upper check valve 4.1 → enters the recovery chamber 1.3, and the oil pressure in the chamber actively increases; at the same time, the lower oil circuit is connected to the low-pressure return oil path, the pressure in the compression chamber 1.4 is reduced by pressure relief, and an active pressure difference is formed between the upper chamber with high pressure and the lower chamber with low pressure, which pushes the piston 1.2 to actively compress downward, and the piston rod 1.5 to actively pull down; Active recovery stroke working process: The upper solenoid valve 3.1 is opened and the lower solenoid valve 3.2 is closed. The motor drives the oil pump 2 to pump oil in reverse → the lower one-way valve 4.2 → enters the compression chamber 1.4, and the chamber oil pressure actively increases; at the same time, the upper oil circuit is connected to the low-pressure return oil path, the pressure in the recovery chamber 1.3 is reduced by pressure relief, and an active pressure difference is formed between the lower chamber high pressure and the upper chamber low pressure, which pushes the piston 1.2 to actively extend upward.

[0040] The key point of this invention lies in achieving a simplified design and flexible mode switching for the active hydraulic suspension system through a single accumulator combined with two flexible hydraulic circuit schemes. Simultaneously, by optimizing the installation method, accumulator type, and guide component, the system's adaptability and stability are improved. Specific key points are as follows: 1. Collaborative design of a single accumulator and multiple components: Using a single accumulator as the core, combined with shock absorbers, solenoid valves, check valves, switching valves, and hydraulic pumps, the system achieves switching between active and semi-active modes, simplifying the system structure; 2. Design of three hydraulic circuit schemes: The pump is connected to the system via a check valve (automatic mode switching) and the pump is connected to the system via a switching valve (manual mode switching). Schemes can be selected independently, and the number of switching valves can be flexibly configured (0, 1, or 2); 3. Flexible installation of the accumulator and pump: They can be installed independently or integrated into the shock absorber body to adapt to different vehicle layout requirements; 4. Variable accumulator type: Piston-type or bag-type accumulators can be selected according to requirements.

[0041] The vehicle chassis hydraulic suspension system described in this invention has the following significant advantages compared to existing technologies: 1. Simplified structure and reduced cost: Adopting a single accumulator design replaces the existing multi-accumulator structure, reducing the number of parts, simplifying the system structure, and lowering procurement, assembly, and maintenance costs; both hydraulic circuit schemes use simple pipeline designs, significantly reducing the failure rate and facilitating maintenance. 2. Flexible and convenient mode switching: Three hydraulic circuit schemes are provided. Scheme 1 enables the active mode of the suspension system, switching between semi-active and active modes by controlling the oil pump speed; Scheme 2 allows for autonomous switching of operating modes, achieving complete decoupling of the two modes, and the number of switching valves can be flexibly configured; Scheme 3 enables automatic switching between semi-active and active modes without manual intervention, with rapid response; adaptable to different user needs and driving conditions, solving the problem of inflexible mode switching in existing systems. 3. Strong installation adaptability: The accumulator and hydraulic pump can be independent or integrated into the shock absorber body, allowing for flexible selection of installation methods based on vehicle chassis layout space and customer needs, significantly improving the system's adaptability to different vehicle models and expanding its application range. 4. Wide range of applications: The accumulator can be modified into piston or bag type, which can be flexibly selected according to the vehicle load requirements, vibration frequency, installation space and other scenarios. It takes into account the system's pressure stability, response speed and installation convenience, and is suitable for different application scenarios such as passenger cars, commercial vehicles and special vehicles.

[0042] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A vehicle chassis hydraulic suspension system, characterized in that: One end of the main oil circuit (A) is connected to the recovery chamber (1.3) of the damper cylinder (1.1), and the other end of the main oil circuit (A) is connected to the compression chamber (1.4) of the damper cylinder (1.1). The main oil circuit (A) is connected to the accumulator (5). The main oil circuit (A) is connected to the oil pump circuit (B). The oil pump circuit (B) is connected to the oil pump (2). An upper check valve (4.1) and an upper solenoid valve (3.1) are installed on the main oil circuit (A) between one connection point of the main oil circuit (A) and the oil pump circuit (B) and one connection point of the accumulator (5) and the main oil circuit (A). A lower check valve (4.2) and a lower solenoid valve (3.2) are installed on the main oil circuit (A) between another connection point of the main oil circuit (A) and the oil pump circuit (B) and another connection point of the accumulator (5) and the main oil circuit (A).

2. The vehicle chassis hydraulic suspension system according to claim 1, characterized in that: The oil pump circuit (B) between one connection point of the oil pump circuit (B) and the main oil circuit (A) and the oil pump (2) is the upper section (B1) of the oil pump circuit. The oil pump circuit (B) between the other connection point of the oil pump circuit (B) and the main oil circuit (A) and the oil pump (2) is the lower section (B2) of the oil pump circuit. An upper switch valve (6.1) is installed in the upper section (B1) of the oil pump circuit, and a lower switch valve (6.2) is installed in the lower section (B2) of the oil pump circuit.

3. A vehicle chassis hydraulic suspension system, characterized in that: One end of the main oil circuit (A) is connected to the recovery chamber (1.3) of the damper cylinder (1.1), and the other end of the main oil circuit (A) is connected to the compression chamber (1.4) of the damper cylinder (1.1). The main oil circuit (A) is connected to the accumulator (5). The main oil circuit (A) is connected to the oil pump circuit (B). The oil pump circuit (B) is connected to the oil pump (2). An upper solenoid valve (3.1) is installed on the main oil circuit (A) between one junction of the main oil circuit (A) and the oil pump circuit (B) and one junction of the accumulator (5) and the main oil circuit (A). A lower solenoid valve (3.1) is installed on the main oil circuit (A) between the other junction of the main oil circuit (A) and the oil pump circuit (B) and another junction of the accumulator (5) and the main oil circuit (A). 3.2) An accumulator oil circuit (C) is set between the upper section (B1) and the lower section (B2) of the oil pump oil circuit (B). The accumulator oil circuit (C) is connected to the accumulator (5). The oil pump oil circuit (B) between one connection point of the oil pump oil circuit (B) and the main oil circuit (A) and the oil pump (2) is the upper section (B1) of the oil pump oil circuit. An upper check valve (4.1) is set on the branch between the upper section (B1) of the oil pump oil circuit (B) and the accumulator (5). The oil pump oil circuit (B) between the other connection point of the oil pump oil circuit (B) and the main oil circuit (A) and the oil pump (2) is the lower section (B2) of the oil pump oil circuit. A lower check valve (4.2) is set on the branch between the lower section (B2) of the oil pump oil circuit (B2) and the accumulator (5).

4. The vehicle chassis hydraulic suspension system according to claim 1, 2, or 3, characterized in that: The damper body (1) includes a damper cylinder (1.1), a piston (1.2) is provided inside the damper cylinder (1.1), the piston (1.2) divides the damper cylinder (1.1) into a recovery chamber (1.3) and a compression chamber (1.4), the piston rod (1.5) is connected to the piston (1.2), and the piston rod (1.5) extends through the recovery chamber (1.3) to the outside of the damper cylinder (1.1).

5. The control method for the vehicle chassis hydraulic suspension system according to claim 1, characterized in that: Including semi-active mode and active mode; In semi-active mode, oil pump (2) does not work; During the compression stroke, the wheel jumps upward, the piston (1.2) moves downward, the piston rod (1.5) retracts, the piston (1.2) squeezes downward, the volume of the compression chamber (1.4) decreases and the oil pressure increases, the volume of the recovery chamber (1.3) increases and the oil pressure decreases; The oil flow direction is: compression chamber (1.4) → lower solenoid valve (3.2) → accumulator (5) → upper solenoid valve (3.1) / upper check valve (4.1) → recovery chamber (1.3); During the recovery stroke, the wheel falls, the piston (1.2) moves upward, the piston rod (1.5) extends, the piston (1.2) is stretched upward, the volume of the recovery chamber (1.3) decreases and the oil pressure increases; the volume of the compression chamber (1.4) increases and the oil pressure decreases. The oil flow direction is: recovery chamber (1.3) → upper solenoid valve (3.1) → accumulator (5) → lower check valve (4.2) / lower solenoid valve (3.2) → compression chamber (1.4).

6. The control method for the vehicle chassis hydraulic suspension system according to claim 5, characterized in that: In active mode, oil pump (2) operates. Active compression stroke working process: The motor drives the oil pump (2) to pump oil in the forward direction → into the recovery chamber (1.3), the oil pressure in the recovery chamber (1.3) actively increases; at the same time, the oil circuit on the lower side is connected to the low-pressure return oil path, and the pressure in the compression chamber (1.4) is reduced by pressure relief; the upper and lower chambers form an active pressure difference of high pressure in the upper chamber and low pressure in the lower chamber, which pushes the piston (1.2) to actively compress downward, and the piston rod (1.5) to actively pull down; Active recovery stroke working process: The motor drives the oil pump (2) to pump oil in reverse → into the compression chamber (1.4), and the oil pressure in the chamber actively increases; at the same time, the oil circuit on the upper side is connected to the low-pressure return oil path, the pressure in the recovery chamber (1.3) is reduced by pressure relief, and an active pressure difference is formed between the lower chamber high pressure and the upper chamber low pressure, which pushes the piston (1.2) to actively extend upward.

7. The control method for the vehicle chassis hydraulic suspension system according to claim 2, characterized in that: Including semi-active mode and active mode; In semi-active mode, In semi-active mode, the upper switch valve (6.1) and the lower switch valve (6.2) are closed, and the oil pump (2) is disconnected from the main oil circuit (A). During the compression stroke, the wheel jumps upward, the piston (1.2) moves downward, the piston rod (1.5) retracts, the piston (1.2) squeezes downward, the volume of the compression chamber (1.4) decreases and the oil pressure increases; the volume of the recovery chamber (1.3) increases and the oil pressure decreases. The oil flow direction is: compression chamber (1.4) → lower solenoid valve (3.2) → accumulator (5) → upper solenoid valve (3.1) / upper check valve (4.1) → recovery chamber (1.3); During the recovery stroke, the wheel falls, the piston (1.2) moves upward, the piston rod (1.5) extends, the piston (1.2) is stretched upward, the volume of the recovery chamber (1.3) decreases and the oil pressure increases; the volume of the compression chamber (1.4) increases and the oil pressure decreases. The oil flow direction is: recovery chamber (1.3) → upper solenoid valve (3.1) → accumulator (5) → lower check valve (4.2) / lower solenoid valve (3.2) → compression chamber (1.4).

8. The control method for the vehicle chassis hydraulic suspension system according to claim 7, characterized in that: In active mode, When the upper switch valve (6.1) and the lower switch valve (6.2) are opened, the high-pressure oil is connected to the oil pump (2) through the switch valve and works in coordination with the accumulator (5) in active mode; Active compression stroke working process: The motor drives the oil pump (2) to pump oil in the forward direction → the upper switch valve (6.1) is energized and fully opened, and high pressure oil is conducted → the oil pressure in the recovery chamber (1.3) actively increases; at the same time, the oil circuit on the lower side is connected to the low pressure return oil path, and the pressure in the compression chamber (1.4) is reduced by pressure relief; an active pressure difference is formed between the upper chamber high pressure and the lower chamber low pressure, which pushes the piston (1.2) to actively compress downward, and the piston rod (1.5) to actively pull down; Active recovery stroke working process: The motor drives the oil pump (2) to pump oil in reverse → the lower switch valve (6.2) is energized and fully opened, and high pressure oil is connected → the oil pressure in the compression chamber (1.4) actively increases; at the same time, the upper oil circuit is connected to the low pressure return oil path, the pressure in the recovery chamber (1.3) is reduced by pressure relief, and an active pressure difference is formed between the lower chamber high pressure and the upper chamber low pressure, which pushes the piston (1.2) to actively extend upward.

9. The control method for the vehicle chassis hydraulic suspension system according to claim 3, characterized in that: Including semi-active mode and active mode; In semi-active mode, oil pump (2) does not work. During the compression stroke, the wheel jumps upward, the piston (1.2) moves downward, the piston rod (1.5) retracts, the piston (1.2) squeezes downward, the volume of the compression chamber (1.4) decreases and the oil pressure increases; the volume of the recovery chamber (1.3) increases and the oil pressure decreases. The oil flow direction is: compression chamber (1.4) → lower solenoid valve (3.2) → accumulator (5) / upper check valve (4.1) / upper solenoid valve (3.1) → recovery chamber (1.3); During the recovery stroke, the wheel falls, the piston (1.2) moves upward, the piston rod (1.5) extends, the piston (1.2) is stretched upward, the volume of the recovery chamber (1.3) decreases and the oil pressure increases; the volume of the compression chamber (1.4) increases and the oil pressure decreases. The oil flow direction is: recovery chamber (1.3) → upper solenoid valve (3.1) → accumulator (5) / lower check valve (4.2) / lower solenoid valve (3.2) → compression chamber (1.4).

10. The control method for a vehicle chassis hydraulic suspension system according to claim 1, characterized in that: In active mode, oil pump (2) operates. Active compression stroke working process: The upper solenoid valve (3.1) is closed and the lower solenoid valve (3.2) is opened. The motor drives the oil pump (2) to pump oil in the forward direction → the upper check valve (4.1) → enters the recovery chamber (1.3), and the oil pressure in the chamber actively increases; at the same time, the lower oil circuit is connected to the low-pressure return oil path, the pressure in the compression chamber (1.4) is reduced by pressure relief, and an active pressure difference is formed between the upper chamber with high pressure and the lower chamber with low pressure, which pushes the piston (1.2) to actively compress downward, and the piston rod (1.5) to actively pull down; Active recovery stroke working process: The upper solenoid valve (3.1) is opened and the lower solenoid valve (3.2) is closed. The motor drives the oil pump (2) to pump oil in reverse → the lower check valve (4.2) → into the compression chamber (1.4), and the chamber oil pressure actively increases; at the same time, the upper oil circuit is connected to the low-pressure return oil path, the pressure of the recovery chamber (1.3) is reduced by pressure relief, and the upper and lower chambers form an active pressure difference of high pressure in the lower chamber and low pressure in the upper chamber, which pushes the piston (1.2) to actively extend upward.

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