Pillar assembly control method based on oil-gas integration

Abstract

The invention relates to the technical field of passenger car suspensions, and provides a strut assembly control method based on oil-gas integration, and in the scheme, the switching capacity among a passive mode, a semi-active mode and a full-active mode is combined so as to adapt to different use scenes. The design not only has very high flexibility and adaptability in function, but also can provide a pressure oil source through the motor oil pump, and improves the response frequency and reduces the energy consumption through reversing of the servo valve. According to the strut assembly based on oil-gas integration, through flexible mode switching, simplified motor oil pump driving and application of the servo valve reversing technology, the whole system has higher response speed, lower energy consumption and higher adaptability while meeting the high-performance requirement. The efficiency and the stability of the system are improved, and the system has wide application prospects in various complex application scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of passenger vehicle suspensions, and particularly to a control method for a strut assembly based on oil-gas integration. Background Art

[0002] With the increasing requirements of passenger vehicles for ride comfort, handling performance, and seating comfort, the suspension system has gradually evolved from traditional passive adaptive suspensions towards intelligentization.

[0003] In the prior art, the development of intelligent suspensions has been accompanied by the need for lightweight and compact structures. Due to their large volume and weight, traditional oil-gas suspensions are mainly used in commercial vehicles, while passenger vehicles tend to use air springs as the support components. The existing modes of passenger vehicle suspensions are few and difficult to adapt to complex and changeable road conditions, and it is also difficult to actively adjust to the road conditions ahead. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to propose a control method for a strut assembly based on oil-gas integration to improve the performance of vehicle suspensions.

[0005] To achieve the above object and other related objects, the present invention proposes a control method for a strut assembly based on oil-gas integration, which is characterized in that it is applied to a strut assembly based on oil-gas integration. The oil-gas integrated strut assembly includes a cylinder component and a floating piston. The floating piston is disposed within the cylinder component and divides the inner cavity of the cylinder component into a pneumatic chamber and a hydraulic chamber. The pneumatic chamber is communicated with a gas source to form an air spring unit. A piston rod connected to the lower control arm or the body of the passenger vehicle is disposed within the hydraulic chamber to form a shock absorber unit. The shock absorber unit includes a servo valve and a CDC valve. The control method for the oil-gas integrated strut assembly includes the following steps:

[0006] Control the actions of the pneumatic chamber, the servo valve, and the CDC valve to enter the passive control mode, semi-active control mode, full-active control mode, stiffness control mode, and lift control mode respectively.

[0007] In a specific embodiment of the present invention, the shock absorber unit includes a piston assembly, a first interface, and a second interface. The servo valve is communicated with the first interface and the second interface. The piston assembly is disposed within the hydraulic chamber and divides the hydraulic chamber into an upper oil chamber and a lower oil chamber. The upper oil chamber and the lower oil chamber are communicated through an oil passage. The first interface is communicated with the upper oil chamber, and the second interface is communicated with the lower oil chamber. At least one of the oil passages is provided with a CDC valve.

[0008] In a specific embodiment of the present invention, controlling the pneumatic chamber, the servo valve, and the CDC valve to operate to enter the passive control mode includes:

[0009] Close the pneumatic chamber, close the servo valve, and keep the CDC valve fully open to enter the passive control mode.

[0010] In a specific embodiment of the present invention, controlling the pneumatic chamber, the servo valve, and the CDC valve to operate to enter the semi-active control mode includes:

[0011] Close the pneumatic chamber, close the servo valve, and control the opening of the CDC valve by passing an electric current to enter the semi-active control mode.

[0012] In a specific embodiment of the present invention, controlling the pneumatic chamber, the servo valve, and the CDC valve to operate to enter the fully active control mode includes:

[0013] Close the pneumatic chamber and the CDC valve, control the servo valve to switch the first interface and the second interface to be the liquid inlet or the liquid outlet and control the opening to enter the fully active control mode.

[0014] In a specific embodiment of the present invention, when compression is required in the fully active control mode, control the servo valve to switch the first interface to be the liquid outlet and the second interface to be the liquid inlet;

[0015] When restoration is required in the fully active control mode, control the servo valve to switch the first interface to be the liquid inlet and the second interface to be the liquid outlet.

[0016] In a specific embodiment of the present invention, controlling the pneumatic chamber, the servo valve, and the CDC valve to operate to enter the stiffness control mode includes:

[0017] Connect the air source, close the CDC valve, and control the servo valve to connect the first interface and the second interface to enter the stiffness control mode.

[0018] In a specific embodiment of the present invention, when the stiffness control mode requires an increase in stiffness, control the pneumatic chamber to exhaust air, and control the servo valve to make the first interface or the second interface be the liquid inlet for oil replenishment;

[0019] When the stiffness control mode requires a decrease in stiffness, control the air source to inflate the pneumatic chamber, and control the servo valve to make the second interface or the first interface be the liquid outlet for discharging excess oil.

[0020] In a specific embodiment of the present invention, controlling the pneumatic chamber, the servo valve, and the CDC valve to operate to enter the lifting control mode respectively includes:

[0021] Close the CDC valve and the servo valve, and control the pneumatic chamber to inflate to enter the lifting control mode.

[0022] In a specific embodiment of the present invention, when the lifting control mode is for ascending, control the air pressure chamber to inflate the air pressure chamber;

[0023] When the lifting control mode is for descending, control the air pressure chamber to exhaust air.

[0024] The present invention provides a control method for a strut assembly based on oil-gas integration. The above solution combines the switching ability between passive, semi-active, and fully active modes to adapt to different usage scenarios. This design not only has high flexibility and adaptability in terms of function, but also can provide a pressure oil source through an electric motor oil pump, and improve the response frequency and reduce energy consumption through a servo valve for commutation. The strut assembly based on oil-gas integration, through flexible mode switching, simplified electric motor oil pump drive, and application of servo valve commutation technology, enables the entire system to have a higher response speed, lower energy consumption, and stronger adaptability while meeting high-performance requirements. This not only improves the efficiency and stability of the system, but also makes it have a broad application prospect in a variety of complex application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic structural diagram of the control method for a strut assembly based on oil-gas integration in an embodiment of the present invention;

[0027] Figure 2 It is a schematic structural principle diagram of the control method for a strut assembly based on oil-gas integration in an embodiment of the present invention;

[0028] Figure 3 It is a schematic diagram of the internal valve port through-hole distribution of the control method for a strut assembly based on oil-gas integration in an embodiment of the present invention;

[0029] Figure 4 It is a diagram of the oil flow direction of passive and semi-active control of the control method for a strut assembly based on oil-gas integration in an embodiment of the present invention;

[0030] Figure 5 It is a diagram of the oil flow direction of fully active control of the control method for a strut assembly based on oil-gas integration in an embodiment of the present invention;

[0031] Figure 6 It is a diagram of the oil flow direction of stiffness adjustment of the control method for a strut assembly based on oil-gas integration in an embodiment of the present invention;

[0032] Figure 7 This is the oil flow diagram of the lifting control mode of the pillar assembly control method based on oil and gas integration in an embodiment of the present invention;

[0033] Figure 8 This is the structural schematic diagram of the pillar assembly control method based on oil and gas integration in another embodiment of the present invention;

[0034] Figure 9 This is the structural principle diagram of the pillar assembly control method based on oil and gas integration in another embodiment of the present invention;

[0035] Figure 10 This is the schematic diagram of the internal valve port through-hole distribution of the pillar assembly control method based on oil and gas integration in another embodiment of the present invention;

[0036] Figure 11 This is the oil flow diagram of the passive and semi-active control of the pillar assembly control method based on oil and gas integration in another embodiment of the present invention;

[0037] Figure 12 This is the oil flow diagram of the full active control of the pillar assembly control method based on oil and gas integration in another embodiment of the present invention;

[0038] Figure 13 This is the oil flow diagram of the stiffness adjustment of the pillar assembly control method based on oil and gas integration in another embodiment of the present invention;

[0039] Figure 14 This is the oil flow diagram of the lifting control mode of the pillar assembly control method based on oil and gas integration in another embodiment of the present invention.

[0040] Explanation of reference numerals: 10, cylinder block assembly; 20, floating piston; 30, air spring unit; 31, air pressure chamber; 32, air tank; 33, air pipe; 34, air valve; 40, shock absorber unit; 41, piston rod; 42, piston assembly; 43, bottom valve; 44, upper oil chamber; 45, lower oil chamber; 46, accumulator; 47, dust cover; 51, fuel tank; 52, hydraulic pump; 53, servo valve; 54, first oil pipe; 55, second oil pipe; 56, third oil pipe; 57, fourth oil pipe; 60, vibration isolation block; 70, CDC valve; 80, buffer block assembly. Detailed implementation manners

[0041] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0042] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. In actual implementation, the type, quantity, and ratio of each component can be arbitrarily changed, and the component layout type may also be more complex.

[0043] Currently, the mainstream passenger car suspensions are divided into two categories: traditional passive adaptive suspensions and semi-active control suspensions. Limited by their fixed damping characteristics, traditional passive adaptive suspensions cannot be adjusted in real time according to changes in road conditions or driving conditions. Therefore, their optimization effect on the driving stability and comfort of passenger cars is limited. The semi-active suspension realizes partial adaptive adjustment through the combination of variable damping CDC adjustment and air springs. Its damping force can be adjusted according to road conditions, thereby providing better handling and comfort. However, this semi-active suspension system still follows the logic of "perception - control - execution", that is, the sensor senses the road conditions and the controller adjusts the damping to achieve the dynamic response of the suspension. Although this method can partially optimize the performance of passenger cars, it still has limitations in the face of special usage conditions.

[0044] In the development path of intelligent suspensions, the suspension form gradually transitions from passive and semi-active to more advanced fully active control. Compared with semi-active suspensions, fully active suspensions have higher responsiveness and prediction capabilities. Through the active control method of "perception - pre-control - pre-execution", they can respond before road conditions change, further improving the driving smoothness and handling safety of passenger cars. Therefore, fully active suspensions are considered the future trend of intelligent suspensions, but their current application scale is small and mainly used in a few high-end models. With the increasing demand for intelligent suspensions, the large-scale application of fully active suspensions will become an inevitable path for the development of suspension systems.

[0045] As Figures 1-14 shown, the present invention proposes a control method for a strut assembly based on oil-gas integration, which is applied to a passenger car and includes a cylinder block assembly 10 and a floating piston 20.

[0046] The floating piston 20 is disposed within the cylinder block assembly 10 and divides the inner cavity of the cylinder block assembly 10 into a pneumatic chamber 31 and a hydraulic chamber. The floating piston 20 separates the oil from the gas. Among them, the pneumatic chamber 31 is communicated with a gas source to form an air spring unit 30, and a piston rod 41 connected to the lower control arm or the vehicle body of a passenger car is disposed within the hydraulic chamber to form a shock absorber unit 40. The gas source includes a gas tank 32, a gas pipe 33, and a gas valve 34 provided on the gas pipe 33.

[0047] Due to the pressure of the charged gas, the floating piston 20 is pushed downward, and then the oil is compressed to push out the piston rod 41 to form a supporting force for supporting the unsprung mass. Through design and verification, the hollow spring part and the shock absorber part of the prior art pillar assembly are deeply integrated into a whole, effectively reducing the volume of the air chamber and simplifying the parts. The gas filled into the upper end of the shock absorber into the pneumatic chamber 31 is pressurized nitrogen with relatively stable performance.

[0048] Combining the pneumatic chamber 31 and the hydraulic chamber within a cylinder block assembly 10, and separating the oil and gas through the floating piston 20 not only reduces the volume of the air chamber, but also deeply integrates the air spring and the shock absorber into an overall structure. Compared with the traditional pillar assembly, the structure of the assembly is greatly simplified, the number of parts is reduced, which helps to improve the manufacturing and assembly efficiency. The lightweight effect brought by the simplified structure and reduced parts can effectively reduce the weight of the whole vehicle, thereby improving the fuel economy or the endurance of an electric vehicle. Since pressurized nitrogen is filled into the pneumatic chamber 31, the floating piston 20 can continuously push out the oil downward, thereby pushing out the piston rod 41 to form a stable supporting force. This design not only meets the supporting requirements for the unsprung mass on the vehicle body, but also improves the supporting stability and response speed of the suspension system under different road conditions.

[0049] As Figure 1 shown, the shock absorber unit 40 further includes a first interface ( Figure 3 port A1 in Figure 3 ), a second interface ( port A2 in

[0050] ), and a servo valve 53, and further includes a liquid supply unit. The liquid supply unit includes an oil tank 51, a hydraulic pump 52, a first oil pipe 54, a second oil pipe 55, a third oil pipe 56, and a fourth oil pipe 57. Figure 4 11 In the solution of the present application, a passive control mode can also be adopted. The oil flow direction is as

[0051] When the piston moves upward (compression), the oil pressure in the upper oil chamber 44 increases. A part of the oil flows from the upper oil chamber 44 to the lower oil chamber 45 through the g and h valve ports of the piston assembly 42. A part of the oil flows from the upper oil chamber 44 through port E, through the CDC valve 70, from the through hole C to the lower oil chamber 45, and then flows through the through hole D into the inside of the piston rod 41, and the accumulator 46 realizes energy storage. In addition, according to the size of the upper valve port of the bottom valve 43 and the number and stiffness of the combined valve plates used, part of the oil will flow from the upper oil chamber 44 to the floating lower oil chamber 45 through the a and b valve ports of the bottom valve 43. Since the air pressure chamber 31 in the upper chamber of the floating piston 20 is filled with pressurized nitrogen, the floating piston 20 moves up and down according to the pressure difference between its upper and lower sides.

[0052] Conversely, when the piston moves downward (recovery), the oil pressure in the lower chamber increases. A part of the oil flows from the lower oil chamber 45 to the upper oil chamber 44 through the e and f valve ports of the piston assembly 42. A part of the oil flows from the lower oil chamber 45 through the through hole C, through the CDC valve 70, and then back to the upper oil chamber 44 through port E. Since the piston rod 41 occupies a certain volume, a certain vacuum will be formed in the upper oil chamber 44. A part of the oil enters the lower oil chamber 45 through the through hole D, and then flows back to the upper oil chamber 44 through the CDC valve 70 from port E, and the accumulator 46 instantaneously replenishes the oil. At the same time, according to the size of the upper valve port of the bottom valve 43 and the number and stiffness of the combined valve plates used, part of the oil flows from the lower chamber of the floating piston 20 to the upper oil chamber 44 through the c and d valve ports of the bottom valve 43.

[0053] During calibration, by adjusting the sizes of the valve ports on the piston assembly 42 and the bottom valve 43, the combined valve plates, as well as the sizes of the clearance oil port E, the through hole C, and the through hole D, the required damping force can be achieved, and the damping force remains unchanged in the passive mode after calibration.

[0054] In a specific embodiment of the present invention, the shock absorber unit 40 includes a piston assembly 42. The piston assembly 42 is disposed in the hydraulic chamber and divides the hydraulic chamber into an upper oil chamber 44 and a lower oil chamber 45. The piston rod 41 is connected to the piston assembly 42. The upper oil chamber 44 and the lower oil chamber 45 are communicated through the working cylinder, the oil storage cylinder in the cylinder block assembly 10, and the oil passages at corresponding positions on the working cylinder. At least one oil passage is provided with a CDC valve 70, so that the damping characteristics of the shock absorber can be adjusted according to road conditions and driving requirements. This configuration of the CDC valve 70 enables the suspension system to achieve real-time adjustment during the dynamic process, thereby improving the handling performance and comfort of the passenger car. The CDC valve 70 can adjust the valve opening according to information such as vehicle speed and vibration feedback by sensors, so as to optimize the damping performance under different road conditions. When the road condition is smooth, the damping is small to enhance comfort; while under bumpy road conditions, the damping is increased to improve vehicle body stability. This design of adaptive damping adjustment significantly improves the adaptability and comfort of the passenger car. By setting the hydraulic chamber as the upper oil chamber 44 and the lower oil chamber 45 and connecting it to the oil passage system, the system can effectively control the flow path of the oil during the shock absorption process. This design avoids possible fluid impacts in the hydraulic system, helps to smooth the shock absorption effect, and thus improves the stability of the system.

[0055] The CDC valve 70 can be used for shock absorption in the semi-active control mode. When switched to this mode, the oil flow direction is shown in Figure 4 .

[0056] In the semi-active mode, the front road surface is scanned in real time by on-vehicle sensors (such as lidar, cameras or ultrasonic sensors) to identify road conditions such as bumps, potholes or undulations. The scanned data is transmitted to the control unit (ECU). The CDC valve 70 changes the valve core opening and adjusts the oil flow velocity in the damper by receiving the current signal from the ECU. For example:

[0057] Bumpy road surface: reduce the damping force (large valve opening), and the suspension becomes soft to absorb shocks;

[0058] Flat road: increase the damping force (small valve opening), and the suspension becomes hard to enhance support.

[0059] Among them, the CDC valve 70 remains normally closed in the middle position (both ports A1 and A2 are blocked), the air valve 34 port remains normally closed (Q is blocked), the CDC valve 70 inputs different currents according to the required damping force, maintains the required opening, and both ports B1 and B2 are open. The oil flow direction in the compression and recovery states in the semi-active control mode is the same as that in the passive control mode.

[0060] Such as Figures 1-7As shown in the figure, in the first embodiment, a foot valve 43 is connected in series on the oil circuit where the CDC valve 70 is located, and two check valves with opposite directions are provided on the foot valve 43. The piston assembly 42, the foot valve 43 and the cylinder block assembly 10 form an upper oil chamber 44; the piston assembly 42, the piston rod 41, the cylinder block assembly 10 and the guide assembly form a lower oil chamber 45. Between the upper and lower chambers of the piston are two check valves configured on the piston assembly 42 and the foot valve 43 and the CDC valve 70. This design ensures that the oil can flow through different paths during compression and rebound, thereby achieving more precise damping control. The combined structure of the piston assembly 42 and the foot valve 43 ensures that the fluid channel between the upper oil chamber 44 and the lower oil chamber 45 is controllable, so that the shock absorption system passes through different oil circuits during rebound and compression respectively. This can achieve higher damping control during compression, and at the same time provide an appropriate buffering effect during rebound, improving the dynamic response of the passenger car suspension system.

[0061] As Figures 8-14 shown, in the second embodiment, the foot valve 43 is cancelled, the two check valves on the piston assembly 42 are cancelled, and the working cylinders at the upper and lower ends of the cylinder block assembly 10 and the oil storage cylinder are both welded and provided with oil passing ports. By cancelling the foot valve 43 and the check valves, the oil circuit structure of the system is greatly simplified, and the number of components is reduced. This simplification not only reduces the production and assembly costs, but also makes the system more compact and saves space. The structure in which the working cylinders at the upper and lower ends of the cylinder block assembly 10 are welded to the oil storage cylinder and provided with oil passing ports enables the oil to flow more quickly between the upper oil chamber 44 and the lower oil chamber 45. This valve-less design reduces the hydraulic resistance and the retention in the oil circuit, improves the dynamic response ability of the system, enables the shock absorber to adapt to road surface changes more quickly, and brings a better driving experience.

[0062] The fuel tank 51 is used to store oil, and the fuel tank 51 is a fully enclosed structure.

[0063] The hydraulic pump 52 is connected to the fuel tank 51 for pumping oil. The hydraulic pump 52 is responsible for pumping oil from the fuel tank 51, and an oil filter is configured at its oil inlet end to ensure the cleanliness of the oil entering the shock absorber and prevent the system from being blocked or worn due to impurities. The hydraulic pump 52 is driven by an electric motor to provide the required pressure source to ensure the stable operation of the system.

[0064] The servo valve 53 is used to switch the connection and opening degree of each interface thereon. The servo valve 53 is connected to the first interface and the second interface, and the servo valve 53 is configured to be able to switch the first interface and the second interface to be the liquid inlet or the liquid outlet.

[0065] The servo valve 53 using servo control can precisely control the injection and discharge of hydraulic oil. The connection relationships and opening degrees among the various interfaces of the servo valve 53 are adjustable, so as to realize the flow control of hydraulic oil between different oil cavities. By controlling the position of the piston assembly 42 through the servo valve 53, the system can achieve pre-adjusted damping force control within the stroke, enabling the shock absorber to have the active control ability of an intelligent suspension.

[0066] The first oil pipe 54 is communicated with the servo valve 53 and the hydraulic pump 52.

[0067] The second oil pipe 55 is communicated with the servo valve 53 and the fuel tank 51.

[0068] The third oil pipe 56 is communicated with the servo valve 53 and the first interface.

[0069] The fourth oil pipe 57 is communicated with the servo valve 53 and the second interface.

[0070] On the other side corresponding to the CDC valve 70, there is a parallel active control oil circuit, which can realize more active control of the inflow and outflow of hydraulic oil when needed.

[0071] In the active mode, the vehicle-mounted sensors (such as lidar, camera or ultrasonic sensor) are used to scan the road surface ahead in real time to identify road conditions such as bumps, potholes or undulations. The scanned data is transmitted to the control unit (ECU), and the algorithm is used to predict the amplitude and timing of the suspension adjustment. The hydraulic pump 52 injects or releases hydraulic oil into the suspension strut assembly according to the instruction to dynamically adjust the suspension. For example:

[0072] When encountering a bump, the hydraulic pump quickly raises the suspension to reduce the impact transmitted to the vehicle body;

[0073] When cornering at high speed, actively increase the stiffness of the outer suspension to suppress roll.

[0074] The above solution greatly improves the comfort, handling limit and vehicle body stability, especially outstanding in complex road conditions.

[0075] The active mode can dynamically adjust the suspension stiffness according to road conditions, providing optimal comfort and vehicle body stability. On flat roads, the suspension can remain soft to provide a better sense of comfort; while on uneven roads, the suspension can quickly adjust to reduce impacts, minimize jolts, and improve overall comfort. In the autonomous driving system, the active mode, in conjunction with the intelligent control system, can provide more accurate road feedback and vehicle dynamic adjustment. Through the integration of in-vehicle sensors and the autonomous driving system, the active mode can be adjusted in real time in autonomous driving mode to adapt to different driving environments and complex situations. It can perform suspension adjustments in advance through predictive algorithms to enhance the stability and comfort of the vehicle in the autonomous driving state. The active mode can adjust the suspension stiffness according to changes in vehicle load, avoiding excessive body sag or instability caused by heavy loads. This not only improves driving comfort but also maintains higher stability during cornering, reduces cargo sway, and enhances safety. In the intelligent transportation system, the active mode can exchange data with traffic flow, vehicle speed, road conditions, etc. in real time, adjust the suspension according to road conditions, keep the vehicle body stable, reduce the driver's burden, and enhance safety. For example, on highways, the system can automatically adjust the suspension to cope with changes in the distance between the vehicle and the vehicle ahead, ensuring a smooth vehicle body.

[0076] Among them, the hydraulic pump 52 supplies pressure oil to this oil circuit to apply higher control force under specific circumstances and achieve fine adjustment during the stroke. Through active pre-adjustment, it adjusts in advance to adapt to road conditions and match the vehicle body state. This design enables the shock absorber to have more precise dynamic control when dealing with complex road conditions, enhancing the ride comfort and stability of the passenger car. The servo valve 53 with servo control and the multi-oil circuit configuration enable the system to perform fully active damping adjustment when external conditions such as vehicle speed and road conditions change. The system can not only provide more refined suspension adjustment but also optimize the comfort during driving and the handling stability of the passenger car. This fully active control system meets the intelligent and fast-response suspension control requirements, providing higher safety and comfort for the passenger car.

[0077] As Figure 1 shown, the oil circuit includes an oil passage hole provided on the piston assembly 42. There is an oil port gap between the working cylinder and the oil storage cylinder of the cylinder block assembly 10. When the piston moves, the oil can flow between the working cylinder and the oil storage cylinder. This enhances the adaptability of the passenger car under various driving conditions. This design not only meets the requirement of rapid response but also performs fine adjustment through the servo control servo valve 53, enabling the shock absorber to have an intelligent suspension control function and bringing a more comfortable and stable driving experience for the passenger car.

[0078] In a specific embodiment of the present invention, the cylinder block assembly 10 is connected to the body of the passenger car, the piston rod 41 is connected to the lower control arm of the passenger car, and the pneumatic chamber 31 is located above the hydraulic chamber. With such a structure, most of the mass is connected to the body, and only the piston rod 41 is connected to the lower control arm of the vehicle, thereby greatly reducing the unsprung mass and improving the performance of the passenger car. A buffer block assembly mounting bracket at the lower end of the piston rod 41 is sleeved with a buffer block assembly 80, which can limit and buffer the suspension compression stroke. The shock absorber guide assembly and the piston assembly 42 are connected by a spring, which can limit and buffer the suspension recovery stroke.

[0079] In a specific embodiment of the present invention, a vibration isolation block 60 is provided between the upper end of the cylinder block assembly 10 and the body. The cylinder block assembly 10 at the upper end of the shock absorber and the vibration isolation block 60 are connected by a stud assembly with a boss and installed in the vibration isolation block mounting bracket. The vibration isolation block mounting bracket is connected to the body through a body connecting piece bolt. Through this preferred design, the shock absorber can isolate the vibration of the body and can be slightly deflected within a certain angle, meeting the requirements of the suspension movement characteristics.

[0080] In a specific embodiment of the present invention, a buffer block assembly 80 is provided at the piston rod. The main function of the buffer block assembly 80 is to absorb and consume the instantaneous impact or severe vibration from the movement of the piston rod. When the shock absorber works, the movement of the piston rod may generate sudden impact forces. If these impact forces are not effectively relieved, they will be transmitted to other system components, causing damage or affecting the use effect. By providing a buffer block at the piston rod, these impact forces can be effectively absorbed, reducing the transmission of vibration, thereby protecting other components of the system from damage.

[0081] As Figure 1 shown, a dust cover 47 covering the piston rod 41 is provided between the lower end of the piston rod 41 and the lower end of the cylinder block assembly 10. The lower end of the dust cover 47 and the mounting accessories are fixed to the buffer block assembly mounting bracket, and the upper end is fixed to the lower end of the cylinder block assembly 10 and fixed with a clamp to isolate the dust outside the buffer block assembly 80 and the cylinder block assembly 10.

[0082] As Figure 1 shown, an accumulator 46 communicating with the lower oil chamber 45 is provided inside the piston rod 41. The piston rod 41 is designed as a hollow structure, and the accumulator 46 is designed inside the piston rod 41. There is an oil port on the piston rod 41, which is communicated with the oil in the cylinder barrel, playing a role in energy storage when the pressure difference changes. Conversely, it can also instantaneously supplement the oil volume. At the same time, the upper pneumatic chamber 31 and the floating piston 20 also play the role of the accumulator 46.

[0083] The present invention also provides a control method for a strut assembly based on oil-gas integration, which is applied to the shock absorber assembly as described above, and includes the following steps:

[0084] Control the actions of the pneumatic chamber 31, the servo valve 53, and the CDC valve 70 to enter the passive control mode, semi-active control mode, full-active control mode, stiffness control mode, and lifting control mode respectively.

[0085] Close the pneumatic chamber 31, close the servo valve 53, and keep the CDC valve 70 fully open to enter the passive control mode.

[0086] In the passive control mode, when the piston moves upward (compression), the oil pressure in the upper chamber of the piston increases. Part of the oil flows from the upper oil chamber 44 to the lower oil chamber 45 through the valve ports g and h, and part of the oil flows from the upper oil chamber 44 through port E, through the CDC valve 70, from the through-hole C to the lower oil chamber 45, and then from the through-hole D into the inside of the piston rod, and the accumulator 46 realizes energy storage. In addition, according to the size of the valve port on the bottom valve 43 and the number and stiffness of the combined valve plates used, part of the oil will flow from the upper oil chamber 44 to the lower oil chamber 45 through the valve port of the bottom valve 43. Since the pneumatic chamber 31 is filled with pressurized nitrogen, the piston assembly 42 moves up and down according to the pressure difference between its upper and lower sides.

[0087] Conversely, when the piston moves downward (recovery), the oil pressure in the lower oil chamber 45 increases. Part of the oil flows from the lower oil chamber 45 to the upper oil chamber 44 through the valve ports e and f of the piston assembly 42, and part of the oil flows from the lower oil chamber 45 through the through-hole C, through the CDC valve 70, and then back to the upper oil chamber 44 through port E. Since the piston rod 41 occupies a certain volume, a certain vacuum will be formed in the upper oil chamber 44. Part of the oil enters the lower oil chamber 45 through the through-hole D, and then flows back to the upper oil chamber 44 through the CDC valve 70 from port E, and the accumulator 46 instantaneously replenishes the oil. At the same time, part of the oil flows from the lower oil chamber 45 to the upper oil chamber 44.

[0088] Close the pneumatic chamber 31, close the servo valve 53, and control the opening of the CDC valve 70 by applying current to enter the semi-active control mode. In the semi-active control mode, the CDC valve 70 inputs different currents according to the required damping force and maintains the required opening, and both ports B1 and B2 are open. The oil flow directions in the compression and recovery states in the semi-active control mode are the same as those in the passive control mode.

[0089] Close the pneumatic chamber 31 and the CDC valve 70, control the servo valve 53 to switch the first interface and the second interface to the liquid inlet or outlet and control the opening to enter the full-active control mode. In the full-active control mode, the oil flow direction is as shown in Figure 6 、 12 shown, and includes the following steps:

[0090] Close the CDC valve 70. Closing the CDC valve 70 means that the CDC valve 70 remains fully closed (input maximum current, keep the passage closed), and both ports B1 and B2 are blocked. At the same time, the air valve 34 air port remains normally closed (Q is blocked).

[0091] Start the hydraulic pump 52. The motor starts and drives the hydraulic pump 52 to work. The hydraulic pump 52 sucks oil from the fuel tank 51 through the oil filter, generates oil with a certain pressure, and transports it to the servo valve 53 end through the hydraulic hose.

[0092] When the air pressure chamber 31 is compressed, the shock absorber needs to be compressed accordingly. When the air pressure chamber 31 is restored, the shock absorber needs to be restored accordingly.

[0093] When the air pressure chamber 31 is in the compressed state, it means that the external force causes the shock absorber to absorb the impact. At this time, the shock absorber performs a compression operation according to the signal of the air pressure chamber 31, increasing the damping force to suppress vibration and improve the vehicle's stability.

[0094] When the air pressure chamber 31 is in the restored state, the shock absorber automatically adjusts to the restored mode according to the restoration signal, so that the shock absorber releases the damping force and returns to the initial state to ensure the comfort of the suspension system. The system monitors the pressure change of the air pressure chamber 31, obtains the required compression or restoration control information of the shock absorber in real time, and combines the servo control of the servo valve 53 to achieve precise control of the shock absorber. Through this information feedback loop, the shock absorber can quickly and accurately respond to the road surface changes during vehicle driving, meeting the dynamic control requirements of the intelligent suspension system.

[0095] When compression is required, control the servo valve 53 to connect the first oil pipe 54 with the fourth oil pipe 57, and connect the second oil pipe 55 with the third oil pipe 56. At this time, the pressurized oil passes through the oil port A2, enters the lower oil chamber 45 through the hole C, and pushes the piston assembly 42 upward (compression); at the same time, a part of the oil enters the inside of the piston rod 41 through the hole D, and the accumulator 46 stores energy. Since the upper oil chamber 44 discharges oil to the oil port A1, due to the existence of the oil pressure difference, a part of the oil flows to the upper oil chamber 44 through the e and f ports of the piston assembly 42, and a part of the oil flows from the lower chamber of the floating piston 20 to the upper oil chamber 44 through the c and d ports of the bottom valve 43, and the floating piston 20 moves downward. The oil in the upper oil chamber 44 flows back to the fuel tank 51 through the gap E port from the oil outlet A1 through the servo valve 53. According to the size of the upper valve port of the bottom valve 43 and the number and stiffness of the combined valve plates used, the damping force of the upper valve port of the bottom valve 43 can be adjusted.

[0096] When restoration is required, control the servo valve 53 to connect the first oil pipe 54 with the third oil pipe 56, and connect the second oil pipe 55 with the fourth oil pipe 57. At this time, the pressurized oil passes through the oil port A1, enters the upper oil cavity 44 through the gap E port, and pushes the piston assembly 42 to move downward (restore). Due to the existence of the oil pressure difference, a part of the oil flows back to the lower oil cavity 45 through the g and h ports of the piston assembly 42, and a part of the oil flows from the upper oil cavity 44 to the lower chamber of the floating piston 20 through the a and b ports of the bottom valve 43. The floating piston 20 moves upward. Since the lower oil cavity 45 is connected to the oil outlet A2, a part of the oil in the lower oil cavity 45 flows out through the through-hole C port, and a part of the oil flows out through the through-hole D port inside the piston rod 41. The accumulator 46 replenishes the oil, and then reaches the servo valve 53 end through the A2 port and returns to the fuel tank 51.

[0097] Connect the air source, close the CDC valve 70, and control the servo valve 53 to connect the first interface and the second interface to enter the stiffness control mode. The oil flow direction in the stiffness control mode is as Figure 7 、 13 shown, including the following steps:

[0098] Obtain the spring stiffness adjustment information. The spring stiffness adjustment information can be actively set by the driver.

[0099] Close the CDC valve 70, and the damping adjustment function is suspended. Input the maximum current to keep the passage closed, and both the B1 and B2 ports are blocked.

[0100] Control the air source and the servo valve 53 to work according to the spring stiffness adjustment information;

[0101] Among them, when the spring stiffness adjustment information is that the spring stiffness needs to be increased, control the air pressure chamber 31 to exhaust. At this time, the coil of the air valve 34 is energized, nitrogen is discharged from the Q port, and the volume of the upper air pressure chamber 31 decreases (the stiffness increases accordingly), and the floating piston 20 moves upward, and the oil is supplemented by flowing in one-way through the A1 or A2 port.

[0102] When the spring stiffness adjustment information is that the spring stiffness needs to be decreased, start the hydraulic pump 52, control the air source to inflate the air pressure chamber 31. At this time, the coil of the air valve 34 is energized, pressurized nitrogen is filled into the Q port, and the volume of the upper air pressure chamber 31 increases (the stiffness decreases accordingly), and the floating piston 20 moves downward, and the excess oil flows back to the fuel tank 51 one-way through the A1 or A2 port.

[0103] When the stiffness adjustment remains unchanged, the coil of the air valve 34 is not energized, and the air path of the Q port is cut off.

[0104] In the above solution, on a bumpy road, the volume of the air pressure chamber can be increased (the stiffness is reduced), the suspension becomes softer, the impact can be fully absorbed, the vehicle body vibration can be reduced, and the riding comfort can be improved.

[0105] When cornering or driving at high speeds, the volume of the pneumatic chamber decreases (stiffness increases), the suspension becomes stiffer, the lateral support force is enhanced, body roll is suppressed, and handling stability is improved.

[0106] When adjusting the stiffness, the floating piston compensates for the displacement through the flow of hydraulic fluid to ensure that the suspension height remains unchanged, avoiding sudden changes in the body posture (such as sudden sinking or elevation) caused by stiffness changes and maintaining driving stability.

[0107] The CDC valve individually adjusts the flow resistance of the hydraulic fluid to precisely absorb high-frequency vibrations (such as fine bumps);

[0108] The pneumatic chamber 31 adjusts the gas compressibility to cope with low-frequency large impacts (such as cornering and acceleration). The two work together to achieve a "soft in the middle and hard on the outside" balance state. After closing the CDC valve, the damping parameters are locked to avoid interference with the shock absorption effect caused by stiffness changes.

[0109] Close the CDC valve 70 and the servo valve 53, and control the charging and discharging of the pneumatic chamber 31 to enter the lifting control mode. The oil flow direction in the lifting control mode is as shown in Figure 8 、 14 and includes the following steps:

[0110] Obtain the stroke adjustment information. The stroke adjustment information refers to the extension or shortening of the suspension stroke, which can be actively input and set by the driver.

[0111] Close the CDC valve 70 and the servo valve 53. The servo valve 53 remains normally closed in the middle position (both ports A1 and A2 are blocked), the air valve 34 port remains open (Q is open), the CDC valve 70 remains fully closed (input the maximum current to keep the passage closed), and both ports B1 and B2 are blocked.

[0112] Exhaust or inflate the pneumatic chamber 31 according to the stroke adjustment information.

[0113] Among them, when the stroke adjustment information is to increase the stroke, the pneumatic chamber 31 is inflated. When the stroke adjustment information is to decrease the stroke, the pneumatic chamber 31 is exhausted. At this time, the air valve 34 coil is energized, the Q port is filled with pressurized nitrogen, the volume of the upper pneumatic chamber 31 increases, the floating piston 20 moves downward, and due to the incompressibility of the hydraulic fluid, the piston rod 41 moves downward (restores), completing the lifting.

[0114] The height adjustment realizes the lifting and lowering of the suspension only through the change of the pneumatic chamber volume, meeting the requirements of multiple scenarios:

[0115] Off-road mode: Increase the suspension stroke (lift the body) to improve passability;

[0116] High-speed mode: Decrease the stroke (lower the body) to reduce wind resistance and enhance ground adhesion.

[0117] The lift mode only changes the volume of the pneumatic chamber, and the suspension stiffness maintains the current setting to ensure seamless function switching.

[0118] Through the collaborative design of pneumatic chamber stiffness adjustment, CDC valve damping control and independent height adjustment, the vehicle achieves a balance between ride comfort and handling, where:

[0119] Ride comfort refers to the full-dimensional filtering from fine vibrations to large impacts, and the passenger comfort is comparable to that of luxury cars;

[0120] Handling refers to the full-scenario coverage from daily commuting to extreme driving, and the body response is as precise as that of performance sports cars.

[0121] The present invention proposes a control method for a strut assembly based on oil-gas integration. In the above solution, the air spring and the shock absorber are combined into one, and the two are integrated together, which not only reduces the overall volume of the system and makes it more suitable for the design requirements of compact passenger cars, but also reduces the weight of the suspension system, thus contributing to the lightweight design of the whole vehicle and improving the energy efficiency of the passenger car. The rubber bladder in the traditional air spring is usually exposed outside and is easily affected by environmental factors such as temperature changes, humidity, corrosive gases, etc., which will accelerate its aging. After canceling the exposed rubber bladder, the new integrated design better protects the inside of the air spring, greatly extends the service life of the components, and reduces the maintenance cost. Compared with the traditional structure, an additional layer of air is added at the upper end of the shock absorber to isolate vibration, and an additional vibration isolation block is also added at the upper end of the air spring for filtering and vibration isolation. It filters the fine high-frequency vibrations of the road surface better. Most of the mass of the structure of the present invention is connected to the vehicle body, and only the piston rod 41 is connected to the lower control arm of the vehicle, thus greatly reducing the unsprung mass. The performance of the passenger car is improved. The air spring shock absorber can be switched arbitrarily between passive, semi-active, and fully active to adapt to more usage scenarios. Active control maximally solves the contradiction between the ride comfort and handling safety of passenger cars. The integration of active control and autonomous driving provides a broader design space for autonomous driving. Currently, for the fully active control of the models on the market, the active force is provided by the forward and reverse rotation of the oil pump, and its disadvantage is that the motor drives the oil pump to rotate forward and backward, and a large amount of energy is required to overcome the rotational inertia force during forward and reverse rotation, and the response frequency is not high. However, in the present invention, the motor and the oil pump rotate in the same direction to provide a pressure oil source, and the direction is changed through the CDC valve 70, with a higher response frequency and lower energy consumption required. Some oil circuits in the CDC part can be completely shut off in the active mode, and the active mode is completely decoupled from the semi-active / passive mode without affecting each other, while the existing products cannot meet this requirement. The strut assembly based on oil-gas integration, through flexible mode switching, simplified motor oil pump drive, and the application of servo valve commutation technology, enables the entire system to have a higher response speed, lower energy consumption, and stronger adaptability while meeting high-performance requirements. This not only improves the efficiency and stability of the system, but also makes it have a wide application prospect in a variety of complex application scenarios.

[0122] The above embodiments are only illustrative of the principles and effects of the present invention, and are not used to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

[0123] In the description herein, numerous specific details are provided, such as examples of components and / or methods, to provide a thorough understanding of embodiments of the present invention. However, those skilled in the art will recognize that embodiments of the present invention may be practiced without one or more of the specific details or with other devices, systems, components, methods, parts, materials, articles, etc. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention.

[0124] Throughout the specification, reference to "an embodiment", "embodiment", or "specific embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention and not necessarily in all embodiments. Thus, appearances of the phrases "in an embodiment", "in embodiments", or "in a specific embodiment" in various places throughout the specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the invention described and illustrated herein may be made in accordance with the teachings herein and will be considered part of the spirit and scope of the present invention.

[0125] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separated or more integrated manner, or even removed in some cases as they are inoperable or provided because they may be useful for a particular application.

[0126] In addition, unless otherwise explicitly indicated, any marked arrows in the figures should be considered merely exemplary and not limiting. Further, unless otherwise indicated, the term "or" as used herein generally intends to mean "and / or". Where the term is anticipated to be unclear due to the ability to provide separation or combination, the combination of components or steps will also be regarded as having been specified.

[0127] As used in the description herein and throughout the claims below, unless otherwise indicated, "a", "an", and "the" include plural references. Also, as used in the description herein and throughout the claims below, unless otherwise indicated, the meaning of "in" includes "in" and "on".

[0128] The foregoing description of the embodiments shown in this invention (including what is described in the abstract of the specification) is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of the invention and examples of the invention have been described herein for illustrative purposes only, various equivalent modifications will be apparent to and can be made by those skilled in the art within the spirit and scope of the invention. As noted, these modifications can be made to the invention in accordance with the foregoing description of the embodiments of the invention, and these modifications will be within the spirit and scope of the invention.

[0129] The systems and methods have been described generally herein to facilitate an understanding of the details of the invention. In addition, various specific details have been given to provide a general understanding of embodiments of the invention. However, those skilled in the relevant art will recognize that embodiments of the invention may be practiced without one or more of the specific details, or with other devices, systems, components, methods, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments of the invention.

[0130] Accordingly, while the invention has been described herein with reference to its specific embodiments, modifications, various changes and substitutions are also within the foregoing disclosure, and it should be understood that in some instances, some features of the invention may be employed without a corresponding use of other features without departing from the scope and spirit of the proposed invention. Therefore, many modifications may be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terms and / or the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Accordingly, the scope of the invention will be determined only by the appended claims.

Claims

1. A control method for a pillar assembly based on oil and gas integration, characterized in that: The invention is applied to a strut assembly based on oil-gas integration, wherein the strut assembly includes a cylinder assembly and a floating piston, wherein the floating piston is arranged in the cylinder assembly and divides the inner cavity of the cylinder assembly into a pneumatic cavity and a hydraulic cavity, wherein the pneumatic cavity is connected to an air source to form an air spring unit, wherein a piston rod connected to a lower arm or a vehicle body of a passenger vehicle is arranged in the hydraulic cavity to form a shock absorber unit, wherein the shock absorber unit includes a servo valve and a CDC valve, and wherein the control method of the strut assembly based on oil-gas integration includes the following steps: The pneumatic chamber, the servo valve and the CDC valve are controlled to respectively enter a passive control mode, a semi-active control mode, a full-active control mode, a stiffness control mode and a lifting control mode.

2. The control method of the pillar assembly based on oil and gas integration according to claim 1 is characterized in that: The shock absorber unit includes a piston assembly, a first interface, and a second interface. The servo valve is connected to the first interface and the second interface. The piston assembly is arranged in the hydraulic chamber and divides the hydraulic chamber into an upper oil chamber and a lower oil chamber. The upper oil chamber and the lower oil chamber are connected through an oil circuit. The first interface is connected to the upper oil chamber, and the second interface is connected to the lower oil chamber. A CDC valve is arranged on at least one of the oil circuits.

3. The control method of the pillar assembly based on oil and gas integration according to claim 2 is characterized in that: Controlling the air pressure chamber, the servo valve and the CDC valve to enter the passive control mode includes: The air pressure chamber is closed, the servo valve is closed, and the CDC valve is kept fully open to enter the passive control mode.

4. The control method of the pillar assembly based on oil and gas integration according to claim 2 is characterized in that: Controlling the air pressure chamber, the servo valve and the CDC valve to enter the semi-active control mode includes: The air pressure chamber is closed, the servo valve is closed, and current is introduced to control the opening of the CDC valve to enter a semi-active control mode.

5. The control method of the pillar assembly based on oil and gas integration according to claim 2 is characterized in that: Controlling the air pressure chamber, the servo valve and the CDC valve to enter a full active control mode includes: The air pressure chamber and the CDC valve are closed, and the servo valve is controlled to switch the first interface and the second interface to be a liquid inlet or a liquid outlet and control the opening to enter a full active control mode.

6. The control method of the pillar assembly based on oil and gas integration according to claim 5 is characterized in that: When compression is required in the fully active control mode, the servo valve is controlled to switch the first interface to a liquid outlet and the second interface to a liquid inlet; When restoration is required in the full active control mode, the servo valve is controlled to switch the first interface to a liquid inlet and the second interface to a liquid outlet.

7. The control method of the pillar assembly based on oil and gas integration according to claim 2 is characterized in that: Controlling the air pressure chamber, the servo valve and the CDC valve to enter the stiffness control mode includes: The gas source is connected, the CDC valve is closed, and the servo valve is controlled to connect the first interface and the second interface to enter the stiffness control mode.

8. The control method of the pillar assembly based on oil and gas integration according to claim 7 is characterized in that: When the stiffness control mode is to increase the stiffness, the air pressure chamber is controlled to exhaust, and the servo valve is controlled to make the first interface or the second interface a liquid inlet for oil replenishment; When the stiffness control mode requires reducing the stiffness, the air source is controlled to inflate the air pressure chamber, and the servo valve is controlled to make the second interface or the first interface a liquid outlet to discharge excess oil.

9. The control method of the pillar assembly based on oil and gas integration according to claim 2 is characterized in that: Controlling the air pressure chamber, the servo valve and the CDC valve to respectively enter the lifting control mode includes: The CDC valve and the servo valve are closed, and the inflation of the air pressure chamber is controlled to enter the lifting control mode.

10. The control method of the pillar assembly based on oil and gas integration according to claim 9 is characterized in that: When the lifting control mode requires lifting, controlling the air pressure chamber to inflate the air pressure chamber; When the lifting control mode requires lowering the lift, the air pressure chamber is controlled to exhaust air.

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