Hydraulic cylinder with high frequency damping and hydraulic suspension device

Abstract

The hydraulic cylinder with high-frequency buffering device and the hydraulic suspension device are provided. The hydraulic cylinder comprises single-ear-ring cylinder bottom, cylinder cover, cylinder barrel, piston and piston rod, etc. Two oil ports are arranged on the side wall of the cylinder barrel and located at both ends of the cylinder barrel. The piston is arranged in the cylinder barrel, and the hydraulic pressure is applied to the piston to drive the piston to move in the cylinder barrel. The piston rod is connected to the piston, and the hydraulic pressure is transmitted to the piston through the piston rod. The buffering device is installed on the cylinder barrel to absorb impact force and vibration. In the buffering device, the end sealing plate is arranged at both ends of the vibration absorption cylinder body, the vibration absorption piston and the elastic device are arranged in the vibration absorption cylinder body, two vibration absorption pistons are arranged at both ends of the vibration absorption cylinder body, and the elastic device is arranged between the two vibration absorption pistons. The outer sides of the two vibration absorption pistons are oil channels, and the inner cavity of the hydraulic cylinder and the pipeline are communicated through the two oil ports. When no hydraulic pressure is applied, the elastic device presses the two vibration absorption pistons on the end sealing plate, and the gap between the vibration absorption piston and the vibration absorption cylinder body is X.

Description

Technical Field

[0001] This invention relates to the field of hydraulic suspension technology, and more particularly to a hydraulic cylinder with a high-frequency buffer device and a hydraulic suspension device. Background Technology

[0002] Hydraulic interconnected suspension can increase vehicle speed by improving vehicle cornering stability. It was already used in rally cars at the end of the last century and has since been widely used in automobiles, rail transportation, ships and military vehicles.

[0003] Hydraulic interconnected suspension has the following advantages:

[0004] (1) Flexible and variable performance and short development cycle: The anti-roll stiffness can be changed by adjusting the accumulator parameters and working pressure of the hydraulic system, without being limited by hardware size;

[0005] (2) Nonlinear stiffness: The hydraulic interconnection system is a nonlinear system. The roll stiffness provided by the system to the vehicle increases significantly with the increase of the roll angle of the vehicle body, thus better balancing comfort and safety.

[0006] (3) Integration: Installing a damping valve on the pipeline can achieve the integration of anti-roll torsion bar and vertical damper;

[0007] (4) Lightweight, cost-effective, and with minimal installation requirements: The steel anti-roll torsion bar is simplified into cylinders, accumulators, and pipelines, which can reduce the weight between the springs; component integration can reduce the cost of the suspension unit; the arrangement of the two hydraulic cylinders is more flexible than that of the steel anti-roll torsion bar device, and the installation requirements are minimal.

[0008] (5) It is easy to achieve active and semi-active control.

[0009] Commonly used hydraulic interconnected suspension systems, such as Figure 1 As shown, it consists of interconnected hydraulic cylinders, damping valves, accumulators, and piping systems. Utilizing the incompressibility of liquids and the compressibility of gases, it provides nonlinear anti-rolling torque, which can significantly improve the safety, comfort, reliability, and efficiency of buses.

[0010] Two hydraulic cylinders are installed on the left and right sides of the vehicle. The upper end of the hydraulic cylinder is connected to the vehicle body, and the lower end is connected to the bogie frame. The upper and lower parts of the two hydraulic cylinders are interconnected to form a circuit. Two accumulators are designed in the middle of the circuit to provide the angle and stiffness for the vehicle body during passive torsion. Working principle: The upper chamber LU of the left hydraulic cylinder is connected to the lower chamber RL of the right hydraulic cylinder, and the lower chamber LL of the left hydraulic cylinder is connected to the upper chamber RU of the right hydraulic cylinder. In this way, the vertical stiffness of the two hydraulic cylinders is close to zero, while the torsional stiffness is not zero. When the vehicle body height decreases, the volume of the two upper chambers LU and RU increases, while the volume of the two lower chambers LL and RL decreases. Due to the circuit connection, the liquid in RL flows to LU, and the liquid in LL flows to RU. If the speed is not high and the effect of liquid viscosity is ignored, the hydraulic pressure change in each chamber and hydraulic cylinder is very small, so the vertical force generated is very small. Conversely, when the vehicle body height increases, the vertical force generated is also very small. When the vehicle rolls, for example, clockwise, the volumes of hydraulic chambers LL and RU increase, while the volumes of chambers LU and RL decrease. This results in a decrease in hydraulic pressure within LL and RU, and an increase in hydraulic pressure within LU and RL, generating a larger restoring torque in the roll direction. When the vehicle moves vertically, the hydraulic oil experiences pressure loss through the damping valve, providing the necessary damping force for the vehicle.

[0011] Hydraulic interconnected suspension systems can integrate vertical dampers and anti-roll torsion bars, offering numerous advantages. However, due to space constraints under the vehicle, the pipeline between the hydraulic cylinder port and the accumulator is relatively long, resulting in lag in oil flow. Transient excitation can cause oil accumulation inside the hydraulic cylinder, leading to a rapid increase in local pressure, similar to a "water hammer" phenomenon. This generates significant vertical forces, resulting in considerable additional stiffness. Consequently, it cannot effectively filter high-frequency vibrations, increasing the vehicle's vertical acceleration and reducing the vehicle's ride quality. Summary of the Invention

[0012] The purpose of this invention is to provide a hydraulic cylinder and a hydraulic suspension device with a high-frequency buffer device, which can eliminate the "water hammer" phenomenon under high-frequency vertical vibration of the hydraulic cylinder, reduce the additional stiffness of the hydraulic cylinder, and thus improve the running quality of the vehicle.

[0013] Therefore, in a first aspect, embodiments of the present invention provide a hydraulic cylinder with a high-frequency buffer device, the hydraulic cylinder comprising:

[0014] The cylinder bottom with a single lug is the bottom of the hydraulic cylinder, and its interior has an inner cavity to accommodate the piston rod movement.

[0015] The cylinder barrel is connected to the cylinder bottom with a single lug and is used to accommodate the piston and withstand hydraulic pressure; two oil ports are opened on the side wall of the cylinder barrel, located at both ends of the cylinder barrel respectively;

[0016] The cylinder head, located on top of the hydraulic cylinder, is used to seal the cylinder barrel;

[0017] A piston is housed within the cylinder. Hydraulic pressure acts on the piston, pushing it to move within the cylinder.

[0018] A piston rod is connected to the piston and transmits hydraulic pressure to the piston; one end of the piston rod passes through the cylinder head and extends outside the hydraulic cylinder.

[0019] A buffer device, installed on the cylinder, is used to absorb impact and vibration;

[0020] The buffer device includes: an end sealing plate, a vibration-absorbing cylinder, a vibration-absorbing piston, and an elastic device;

[0021] The end sealing plates are disposed at both ends of the vibration-absorbing cylinder body, and the vibration-absorbing pistons and elastic devices are disposed within the vibration-absorbing cylinder body. There are two vibration-absorbing pistons, respectively disposed at both ends of the vibration-absorbing cylinder body, with an elastic device between the two vibration-absorbing pistons. The outer sides of the two vibration-absorbing pistons are oil passages, which connect the hydraulic cylinder cavity and pipeline through the two oil ports. When no hydraulic pressure is applied, the elastic device presses the two vibration-absorbing pistons against the end sealing plates, and the gap between the vibration-absorbing pistons and the vibration-absorbing cylinder body is X.

[0022] Preferably, the space between the two vibration-absorbing pistons is filled with vibration-absorbing material and sealed in the vibration-absorbing cylinder by a screw plug.

[0023] Preferably, the end sealing plate is fixed to the vibration-absorbing cylinder body by screws, and an elastic washer is provided between the screws and the end sealing plate; the end sealing plate and the vibration-absorbing cylinder body are sealed by a sealing ring.

[0024] Preferably, the hydraulic cylinder further includes a piston sealing system located outside the piston for sealing the hydraulic fluid inside the cylinder while allowing the piston to move within the cylinder.

[0025] Preferably, the hydraulic cylinder further includes a cylinder head sealing system located at the bottom of the cylinder head to prevent hydraulic fluid leakage.

[0026] Preferably, the hydraulic cylinder further includes:

[0027] The upper piston rod sealing system, located between the piston rod passing through the cylinder head and the cylinder head, is used to prevent hydraulic fluid leakage;

[0028] The lower piston rod sealing system, located between the lower piston rod and the cylinder bottom with a single lug, is used to prevent hydraulic fluid leakage.

[0029] Preferably, when the hydraulic cylinder is filled with hydraulic fluid and reaches the equilibrium pressure, the hydraulic fluid enters the buffer device through the oil circuit, and the gap between the vibration-absorbing piston, the vibration-absorbing cylinder body, and the end sealing plate all become X / 2, and the hydraulic cylinder is in a balanced state.

[0030] Preferably, when the oil pressure changes, the damping piston of the buffer device responds to the oil pressure change, reduces the vibration and impact caused by the oil pressure change through the elastic device, and adapts to the pressure change of the oil circuit by moving the damping piston, thereby reducing the vibration of the hydraulic cylinder.

[0031] Preferably, the hydraulic cylinder further includes:

[0032] The lower rubber ball joint is press-fitted into the bottom of the cylinder with a single lug through an interference fit, serving as the connection point of the lower part of the hydraulic cylinder;

[0033] A single lug is mounted on the piston rod at one end that passes through the cylinder head;

[0034] The upper rubber ball joint is press-fitted into the single lug through an interference fit, serving as the connection point for the upper part of the hydraulic cylinder.

[0035] Secondly, embodiments of the present invention provide a hydraulic suspension device, including the hydraulic cylinder with a high-frequency buffer device described in the first aspect above.

[0036] The hydraulic cylinder with a high-frequency buffer device provided in this invention has a compact structure and occupies little space. When applied to a hydraulically interconnected suspension, it can eliminate the "water hammer" phenomenon inside the hydraulic cylinder under high-frequency vertical vibration, avoid generating large vertical forces in the hydraulic cylinder, effectively reduce additional stiffness under high-frequency operating conditions, better filter out high-frequency vibrations, and improve the vehicle's running quality. At the same time, it has minimal impact on the device's anti-roll and damping functions. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a hydraulically interconnected suspension system commonly used in existing technologies.

[0038] Figure 2 A schematic diagram of a hydraulic cylinder with a high-frequency buffer device provided in an embodiment of the present invention;

[0039] Figure 3 A cross-sectional schematic diagram of the buffer device provided in an embodiment of the present invention;

[0040] Figure 4 A three-dimensional structural schematic diagram of the buffer device provided in an embodiment of the present invention;

[0041] Figure 5 A schematic diagram of a hydraulic interconnected suspension device with a buffer device provided in an embodiment of the present invention;

[0042] Figure 6 The additional stiffness test comparison curves of hydraulic cylinders with and without buffer devices are provided for embodiments of the present invention. Detailed Implementation

[0043] To more clearly illustrate the purpose and advantages of the present invention, the present invention will be further described below with reference to embodiments. The embodiments described in the present invention are only some embodiments. Based on the embodiments described in the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention. In addition, it should be understood that these embodiments are only for more detailed description and should not be construed as limiting the present invention in any way, that is, they are not intended to limit the protection scope of the present invention.

[0044] This invention provides a hydraulic cylinder with a high-frequency buffer device, the structure of which is as follows: Figure 2 As shown, the hydraulic cylinder includes:

[0045] The cylinder bottom 2 with a single lug is the bottom of the hydraulic cylinder, and its interior has an inner cavity that accommodates the piston rod movement.

[0046] The cylinder 6 is connected to the cylinder bottom 2 with a single lug and is used to house the piston and withstand hydraulic pressure. Two oil ports are opened on the side wall of the cylinder 6, located at both ends of the cylinder 6. The cylinder 6 is made of metal and has a smooth internal surface to reduce friction.

[0047] The cylinder head 8, located on top of the hydraulic cylinder, is used to seal the cylinder barrel 6; the cylinder head 8 can be removed for maintenance and repair.

[0048] Piston 4 is housed inside cylinder 6. Hydraulic pressure acts on piston 4, pushing piston 4 to move inside cylinder 6.

[0049] The piston rod 7 is connected to the piston 4, and hydraulic pressure is transmitted to the piston 4 through the piston rod 7; one end of the piston rod 7 passes through the cylinder head 8 and extends out of the hydraulic cylinder.

[0050] The piston sealing system 5, located outside the piston 4, is used to seal the hydraulic fluid inside the cylinder 6 while allowing the piston 4 to move within the cylinder 6.

[0051] Cylinder head sealing system 9, located at the bottom of cylinder head 8, is used to prevent hydraulic fluid leakage.

[0052] The upper piston rod sealing system 10 is located between the piston rod 7, which passes through the cylinder head 8, and the cylinder head 8, and is used to prevent hydraulic fluid leakage.

[0053] The lower piston rod sealing system 3, located between the lower piston rod 7 and the cylinder bottom 2 with a single lug, is used to prevent hydraulic fluid leakage.

[0054] The lower rubber ball joint 1 is press-fitted into the bottom of the cylinder 2 with a single lug by an interference fit, serving as the connection point of the lower part of the hydraulic cylinder, allowing a certain degree of deflection and torsion.

[0055] A single earring 11 is disposed on the piston rod 7, which passes through one end of the cylinder head 8.

[0056] The upper rubber ball joint 12 is press-fitted into the single lug 11 with an interference fit, serving as the connection point of the upper part of the hydraulic cylinder, allowing a certain degree of swing.

[0057] The buffer device 13 is installed on the cylinder 6 to absorb impact and vibration.

[0058] The aforementioned components work together to transmit pressure and power through hydraulic principles, thereby enabling the movement and operation of the hydraulic cylinder. The addition of the buffer device 13 helps to smooth the movement of the hydraulic cylinder and reduce impact and vibration.

[0059] Specifically, the three-dimensional structure of the buffer device is as follows: Figure 4 As shown, the buffer device is welded between the two oil ports of the hydraulic cylinder. The cross-sectional structure of the buffer device 13 is as follows. Figure 3 As shown, it includes: an end sealing plate 131, a vibration-absorbing cylinder 132, a vibration-absorbing piston 133, and an elastic device 135;

[0060] End sealing plates 131 are installed at both ends of the vibration-absorbing cylinder body 132, and vibration-absorbing pistons 133 and elastic devices 135 are installed inside the vibration-absorbing cylinder body 132. There are two vibration-absorbing pistons 133, which are respectively installed at both ends inside the vibration-absorbing cylinder body 132. There is an elastic device 135 between the two vibration-absorbing pistons 133. The elastic device 135 can be a steel spring or a rubber column. The outer side of the two vibration-absorbing pistons 133 is an oil passage, which connects the hydraulic cylinder cavity and the pipeline through two oil ports.

[0061] The space between the two vibration-absorbing pistons 133 is filled with vibration-absorbing material 136, such as asphalt or soft silicone, and sealed in the vibration-absorbing cylinder 132 by a screw plug 134; the end sealing plate 131 is fixed to the vibration-absorbing cylinder 132 by screws 138, and an elastic washer 139 is provided between the screws 138 and the end sealing plate 131; the end sealing plate 131 and the vibration-absorbing cylinder 132 are sealed by a sealing ring 137.

[0062] In the aforementioned buffer device 13, the vibration-absorbing piston 133 is connected to the hydraulic fluid in the hydraulic cylinder via oil passages on both sides, while allowing the piston to move freely within the vibration-absorbing cylinder body 132. Springs and vibration-absorbing material 136 are located around the vibration-absorbing piston 133 to provide vibration absorption and cushioning. A plug 134 is used to seal the interior of the vibration-absorbing device, ensuring that all components are securely held in place. This combination enables the buffer device 13 to effectively absorb and mitigate vibrations and impacts in the hydraulic system, improving system stability and performance.

[0063] Specifically, under different hydraulic conditions, the working states of the hydraulic cylinder with high-frequency buffer device and the buffer device 13 are as follows:

[0064] When no hydraulic pressure is applied, the elastic device 135 presses the two vibration-absorbing pistons 133 onto the end sealing plate 131, and the gap between the vibration-absorbing pistons 133 and the vibration-absorbing cylinder 132 is X.

[0065] When the hydraulic cylinder is filled with hydraulic fluid and reaches the equilibrium pressure, the hydraulic fluid enters the buffer device 13 through the oil circuit. The vibration-absorbing piston 133 is in an intermediate state to ensure that the vibration-absorbing piston 133 has room to expand and contract when the hydraulic cylinder vibrates. At this time, the gap between the vibration-absorbing piston 133, the vibration-absorbing cylinder body 132, and the end sealing plate 131 all become X / 2, and the hydraulic cylinder is in a balanced state. If the equilibrium pressure is large, the elastic device 135 will be compressed, and the vibration-absorbing material 136, such as asphalt or soft silicone, filled around the elastic device 135 can ensure the gap value of X / 2 after filling to the equilibrium pressure.

[0066] When the oil pressure changes, the vibration-absorbing piston 133 of the buffer device 13 responds to the oil pressure change. The vibration-absorbing piston 133 moves from the high-pressure oil circuit to the low-pressure oil circuit to avoid a rapid increase in the oil pressure of a certain oil circuit. That is, the movement of the vibration-absorbing piston 133 adapts to the pressure change of the oil circuit, thereby reducing the vibration of the hydraulic cylinder. At the same time, the elastic device 135 reduces the vibration and impact caused by the oil pressure change. Asphalt or soft silicone shock-absorbing materials can produce a good absorption effect for some high-frequency, low-amplitude oil pressure changes.

[0067] In summary, the buffer device 13, through the vibration absorption characteristics of the elastic device 135 and the vibration-absorbing material 136, as well as the movement of the vibration-absorbing piston 133, can quickly and sensitively adjust the pressure inside the hydraulic cylinder, reduce vibration and impact in the hydraulic system, effectively eliminate the "water hammer" phenomenon caused by high-frequency vibration of the hydraulic cylinder, thereby protecting the hydraulic system and improving its stability and performance.

[0068] The hydraulic cylinder provided in this embodiment of the invention is used in a hydraulic interconnected suspension device with a buffer device. Figure 5 It provides a specific application method.

[0069] The installation method of hydraulic cylinders with buffer devices in hydraulic interconnected suspension devices is as follows: Figure 5 As shown. The upper oil circuit of the buffer is welded to the upper oil port of the hydraulic cylinder, and the lower oil circuit is welded to the lower oil port of the hydraulic cylinder. The upper interface of the hydraulic cylinder 101 buffer is connected to the damping valve 1, accumulator 121 and damping valve 4 through pipelines, and is connected to the lower interface of the hydraulic cylinder 201 buffer. The lower interface of the hydraulic cylinder 101 buffer is connected to the damping valve 2, accumulator 221 and damping valve 3 through pipelines, and is connected to the upper interface of the buffer valve of the hydraulic cylinder 201.

[0070] Hydraulic cylinders with vibration absorption devices provide damping and anti-roll functions in hydraulic interconnected suspension systems.

[0071] Damping function: At low and medium frequencies, the upper platform vibrates vertically, and the oil flows fully between the pipelines, so the damper has little effect on damping.

[0072] Anti-roll function: When the upper platform rolls counterclockwise, the space in the lower chamber of hydraulic cylinder 101 and the upper chamber of hydraulic cylinder 201 decreases, increasing the pressure; conversely, the space in the upper chamber of hydraulic cylinder 101 and the lower chamber of hydraulic cylinder 201 increases, decreasing the pressure. Therefore, the two pistons of buffer valve 111 move upward, and the two pistons of buffer valve 211 move downward. Due to the small internal volume of the buffer, the anti-roll torque is reduced under small-amplitude roll conditions, while the impact on the anti-roll torque is smaller under large-amplitude roll conditions, thus still achieving the anti-roll function well.

[0073] The present invention also compared the hydraulic cylinder without a buffer device with the hydraulic cylinder with a buffer device proposed in this embodiment through testing, and the results are as follows. Figure 6 As shown, compared to the design without a buffer device, the additional stiffness of the hydraulic cylinder with a buffer device is greatly reduced.

[0074] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydraulic cylinder with a high-frequency buffer device, characterized in that, The hydraulic cylinder includes: The cylinder bottom with a single lug is the bottom of the hydraulic cylinder, and its interior has an inner cavity to accommodate the piston rod movement. The cylinder barrel is connected to the cylinder bottom with a single lug and is used to accommodate the piston and withstand hydraulic pressure; two oil ports are opened on the side wall of the cylinder barrel, located at both ends of the cylinder barrel respectively; The cylinder head, located on top of the hydraulic cylinder, is used to seal the cylinder barrel; A piston is housed within the cylinder. Hydraulic pressure acts on the piston, pushing it to move within the cylinder. A piston rod is connected to the piston and transmits hydraulic pressure to the piston; one end of the piston rod passes through the cylinder head and extends outside the hydraulic cylinder. A buffer device, installed on the cylinder, is used to absorb impact and vibration; The buffer device includes: an end sealing plate, a vibration-absorbing cylinder, a vibration-absorbing piston, and an elastic device; The end sealing plates are disposed at both ends of the vibration-absorbing cylinder body, and the vibration-absorbing pistons and elastic devices are disposed within the vibration-absorbing cylinder body. There are two vibration-absorbing pistons, respectively disposed at both ends of the vibration-absorbing cylinder body, with an elastic device between the two vibration-absorbing pistons. The outer sides of the two vibration-absorbing pistons are oil passages, which connect the hydraulic cylinder cavity and pipeline through the two oil ports. When no hydraulic pressure is applied, the elastic device presses the two vibration-absorbing pistons against the end sealing plates, and the gap between the vibration-absorbing pistons and the vibration-absorbing cylinder body is X.

2. The hydraulic cylinder with high-frequency buffer device according to claim 1, characterized in that, The space between the two vibration-absorbing pistons is filled with vibration-absorbing material and sealed in the vibration-absorbing cylinder by a screw plug.

3. The hydraulic cylinder with a high-frequency buffer device according to claim 1, characterized in that, The end sealing plate is fixed to the vibration-absorbing cylinder body by screws, and an elastic washer is provided between the screws and the end sealing plate; the end sealing plate and the vibration-absorbing cylinder body are sealed by a sealing ring.

4. The hydraulic cylinder with a high-frequency buffer device according to claim 1, characterized in that, The hydraulic cylinder also includes a piston sealing system located outside the piston. This system seals the hydraulic fluid inside the cylinder while allowing the piston to move within the cylinder.

5. The hydraulic cylinder with high-frequency buffer device according to claim 1, characterized in that, The hydraulic cylinder also includes a cylinder head sealing system located at the bottom of the cylinder head to prevent hydraulic fluid leakage.

6. The hydraulic cylinder with high-frequency buffer device according to claim 1, characterized in that, The hydraulic cylinder also includes: The upper piston rod sealing system, located between the piston rod passing through the cylinder head and the cylinder head, is used to prevent hydraulic fluid leakage; The lower piston rod sealing system, located between the lower piston rod and the cylinder bottom with a single lug, is used to prevent hydraulic fluid leakage.

7. The hydraulic cylinder with high-frequency buffer device according to claim 1, characterized in that, When the hydraulic cylinder is filled with hydraulic fluid and reaches the equilibrium pressure, the hydraulic fluid enters the buffer device through the oil circuit. The gap between the vibration-absorbing piston, the vibration-absorbing cylinder body, and the end sealing plate all become X / 2, and the hydraulic cylinder is in a balanced state.

8. The hydraulic cylinder with a high-frequency buffer device according to claim 1, characterized in that, When the oil pressure changes, the damping piston of the buffer device responds to the oil pressure change, and the elastic device reduces the vibration and impact caused by the oil pressure change. The damping piston moves to adapt to the pressure change in the oil circuit, thereby reducing the vibration of the hydraulic cylinder.

9. The hydraulic cylinder with a high-frequency buffer device according to claim 1, characterized in that, The hydraulic cylinder also includes: The lower rubber ball joint is press-fitted into the bottom of the cylinder with a single lug through an interference fit, serving as the connection point of the lower part of the hydraulic cylinder; A single lug is mounted on the piston rod at one end that passes through the cylinder head; The upper rubber ball joint is press-fitted into the single lug through an interference fit, serving as the connection point for the upper part of the hydraulic cylinder.

10. A hydraulic suspension device, characterized in that, The hydraulic suspension device includes a hydraulic cylinder with a high-frequency buffer device as described in any one of claims 1-9.

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