Hydraulic pilot type adjustable pre-load damper

Abstract

The present application relates to the technical field of shock absorber, in particular to a hydraulic pilot type adjustable pre-tightening shock absorber. The hydraulic pilot type adjustable pre-tightening shock absorber comprises a piston assembly for providing damping and a hydraulic drive assembly, the piston assembly is externally provided with a spring member, one end of the spring member is fixed on the piston assembly, the spring member is used for providing damping force for the piston assembly, wherein the other end of the spring member is connected with the hydraulic drive assembly, the hydraulic drive assembly provides axial adjustment force to change the pre-tightening force of the spring member on the piston assembly; the hydraulic drive assembly comprises a valve sleeve provided with a pressure control part and an output mover, the output mover is installed in the valve sleeve, and there is a gap between the output mover and the upper part of the valve sleeve, the output mover is in sliding fit with the valve sleeve, and can rotate and axially move relative to the valve sleeve. The problem solved by the present application is to provide a shock absorber with compact structure, fast response, easy engineering implementation and effective improvement of vehicle adaptability.

Description

Technical Field

[0001] This invention relates to the field of vibration damper technology, and more specifically, to a hydraulically piloted adjustable preload vibration damper. Background Technology

[0002] Motorcycles are compact, lightweight, and have short suspension travel, making them more susceptible to impacts from uneven road surfaces, potholes, and continuous vibrations during riding. The performance of the suspension system directly affects the overall comfort, handling, and safety of the motorcycle.

[0003] Currently, motorcycle suspension systems generally employ a combination of springs and hydraulic damping elements to achieve both vibration reduction and support. The spring preload directly determines the static deflection of the suspension, the vehicle's posture, and its adaptability under different loads. Traditional motorcycles mostly use threaded retaining rings or multi-position slot structures to adjust the spring preload. While these methods are simple in structure and low in manufacturing cost, they suffer from inconvenience in operation, limited adjustment range, and inability to achieve dynamic adjustment. In scenarios where frequent suspension optimization based on road conditions, load, or riding mode is required, these traditional adjustment methods often fail to meet actual needs.

[0004] In recent years, some high-end motorcycle models have attempted to introduce motor-driven automated adjustment mechanisms to achieve rapid adjustment of spring preload through lead screws or gear mechanisms. However, such mechanical solutions generally suffer from drawbacks such as large size, complex transmission chains, high energy consumption, and limited response speed. On motorcycles, a platform highly sensitive to space, weight, and energy efficiency, complex motor drive solutions not only increase system costs but also pose challenges in terms of durability and reliability.

[0005] Meanwhile, hydraulic drive has attracted attention in adjustable suspension technology due to its high power density and fast response speed. However, most existing adjustable preload solutions based on hydraulic valve control require additional electro-hydraulic control units, pipelines and valves, resulting in high system complexity and integration difficulty. Moreover, they are often difficult to engineer in the limited installation space of motorcycles.

[0006] In summary, existing methods for adjusting the preload of motorcycle shock absorbers are either too simplistic and difficult to adapt to complex working conditions, or the systems are complex and limited in integration. There is still a lack of a shock absorber that is compact in structure, fast in response, and easy to implement in engineering. Summary of the Invention

[0007] The problem solved by this invention is to provide a shock absorber that is compact in structure, fast in response, easy to implement in engineering, and can effectively improve vehicle adaptability.

[0008] The present invention adopts the following technical solution: a hydraulically piloted adjustable preload damper, comprising: a piston assembly for providing damping and a hydraulic drive assembly; a spring element is provided on the outside of the piston assembly, one end of the spring element is fixed on the piston assembly, and the spring element is used to provide damping force to the piston assembly; the other end of the spring element is connected to the hydraulic drive assembly, and the hydraulic drive assembly provides axial adjustment force to change the preload force of the spring element on the piston assembly; the hydraulic drive assembly includes a valve sleeve with a pressure control part and an output mover; the output mover is installed in the valve sleeve and has a gap with the upper part of the valve sleeve to accommodate hydraulic oil; the output mover slides with the valve sleeve and can rotate and move axially relative to the valve sleeve; the output mover is provided with a fluid flow channel, which connects the gap and the pressure control part; wherein, when the output mover rotates, the connecting area of ​​the fluid flow channel changes, thereby causing the output mover to move axially, so as to change the axial adjustment force.

[0009] Compared with existing technologies, the technical effects achieved by this solution are as follows: By connecting the spring component to the hydraulic drive assembly, the preload of the spring component can be dynamically and rapidly adjusted using the hydraulic servo principle. Specifically, the output mover in the hydraulic drive assembly can rotate and move axially within the valve sleeve. By changing the connectivity area of ​​the fluid flow channel, the oil pressure acting on the gap between the valve sleeve and the output mover is adjusted, thereby generating a variable axial adjustment force. This axial adjustment force directly changes the preload state of the spring component on the piston assembly, allowing the damping characteristics of the shock absorber to be adjusted as needed. This design combines the high precision and large thrust of hydraulic servo control with the controllability of screw transmission, achieving linear and continuous adjustment of the preload, improving the shock absorber's adaptability to different working conditions. By adjusting the preload in real time, the shock absorber can provide soft damping to improve comfort under no-load conditions and provide sufficient support to ensure stability and safety under heavy load conditions. Secondly, the hydraulic servo-based control method has a fast response speed and high adjustment precision, which is conducive to achieving synergistic optimization between the shock absorber and the entire vehicle system, improving overall performance. Furthermore, this structure integrates the drive and actuator inside the shock absorber, resulting in a relatively compact structure that helps save installation space and improves the overall reliability of the system.

[0010] Furthermore, the output mover is a column with a spiral groove, through which the fluid flow channel passes. The spiral groove cooperates with the pressure control part on the valve sleeve. One end face of the column forms a pressure bearing surface. The pressurized oil flowing through the spiral groove acts on the pressure bearing surface, causing the column to move axially and generate an axial adjustment force. When the column rotates, the communication area between the spiral groove and the pressure control part changes.

[0011] Compared with existing technologies, the technical effects achieved by this solution are as follows: By designing the output mover as a column with a helical groove and cooperating with the pressure control part on the valve sleeve, a highly integrated mechanical and hydraulic conversion mechanism is formed. This design utilizes the geometric characteristics of the helical groove to linearly convert the rotation angle into the flow area, thereby regulating the flow rate and pressure of the oil flowing towards the pressure-bearing surface. The pressurized oil acts on the pressure-bearing surface at the end of the column, directly converting the hydraulic pressure into the driving force that propels the column to move axially. This solves the problems of traditional shock absorbers, such as complex structure, large space occupation, long transmission chain, and significant response delay, enabling its effective application in space-constrained scenarios such as motorcycle shock absorbers where rapid response is required.

[0012] Furthermore, the pressure control unit includes a hydraulic port and a hydraulic circuit. The hydraulic port is located on the valve sleeve and is connected to the spiral groove. The hydraulic circuit pressurizes or depressurizes the fluid flow channel through the hydraulic port.

[0013] Compared with existing technologies, the technical advantages of this solution are as follows: First, due to the highly integrated and extremely short flow channels, the process of hydraulic oil acting on the pressure-bearing surface or releasing pressure and dissipating force is much faster, significantly reducing the system's response time. Simultaneously, it avoids pressure attenuation and fluctuations caused by long pipelines, making the axial displacement control of the output mover more precise, indirectly improving the linearity and accuracy of spring preload adjustment. Second, this compact integrated design reduces potential leakage points and cavity volume in the system, contributing to improved hydraulic system rigidity. This allows the system to more effectively suppress pressure fluctuations when dealing with rapidly changing loads, ensuring the shock absorber provides stable damping force under various operating conditions. Third, the coordinated design of hydraulic orifices and hydraulic circuits integrates key pressure control functions within the valve sleeve, facilitating the miniaturization and modularization of the entire hydraulic drive assembly, making it easier to install on platforms with limited installation space, such as motorcycles. Furthermore, the reduction in the number of components and the simplification of connecting pipelines also reduce the risk of failures due to loose joints, pipe wall wear, etc., improving the overall reliability of the system.

[0014] Furthermore, the hydraulic circuit includes a hydraulic pump and a two-position two-way solenoid valve. The hydraulic pump is used to provide pressurized oil, and the outlet of the hydraulic pump is connected to the oil inlet of the two-position two-way solenoid valve. The working oil port of the two-position two-way solenoid valve is connected to the hydraulic port, and the two-position two-way solenoid valve is used to control the on / off state of the hydraulic circuit.

[0015] Compared with existing technologies, the technical advantages achieved by this solution are as follows: Highly efficient and precise hydraulic circuit control is achieved through direct coupling of a hydraulic pump and a 2-position 2-way solenoid valve. The hydraulic pump, as the power source, continuously supplies pressurized hydraulic fluid, and its outlet is directly connected to the inlet of the 2-position 2-way solenoid valve. This solenoid valve, as the core control switch, has its working port directly connected to the hydraulic port of the actuator. When the solenoid valve is energized and opened, pressurized hydraulic fluid flows through, driving the output mover to move axially; when the solenoid valve is de-energized and closed, the hydraulic circuit is cut off, and the system can achieve pressure holding or unloading according to the design.

[0016] Furthermore, the hydraulic drive assembly also includes a drive unit, which is connected to the output mover and is used to drive the output mover to rotate.

[0017] Compared with existing technologies, the technical effects achieved by this solution are as follows: By introducing a drive unit and connecting it to the output mover, the drive unit, valve sleeve, and pressure control unit of the hydraulic drive assembly can be modularly designed and arranged. This improves the space utilization of the hydraulic drive assembly and makes the entire hydraulic drive assembly structure more compact.

[0018] Furthermore, the drive unit includes a stepper motor and a drive gear driven by the stepper motor; the end of the output mover is fixed to the driven gear, and the driven gear meshes with the drive gear.

[0019] Compared with existing technologies, the technical effects achieved by this solution are as follows: The stepper motor receives pulse signals from the damper control unit, with each pulse corresponding to a fixed rotation angle. High-precision positioning under open-loop control can be achieved without additional feedback sensors. Through gear transmission and possible speed reduction and torque amplification, the precise rotation angle of the stepper motor is ultimately converted into an equally precise rotation angle of the output mover, thereby accurately adjusting the opening of the fluid flow channel and achieving stepless or graded adjustment of the damping force. Simultaneously, the meshing transmission between the driving and driven gears allows for a lateral arrangement of the motor, fully utilizing the narrow space on the side of the damper, achieving a high degree of integration and modularity.

[0020] Furthermore, the hydraulic drive assembly also includes: a connector that is fixedly connected to the end of the driven gear and the output mover, so that the rotation of the driven gear can drive the output mover to rotate synchronously; and an end cover with a constraint mechanism that cooperates with the connector to allow the whole consisting of the output mover and the driven gear to move axially and restrict the whole circumferential rotation.

[0021] Compared with existing technologies, the technical advantages achieved by this solution are as follows: First, the rigid connection between the output end of the driven gear and the drive end of the output mover by the connector eliminates backlash in the transmission chain to the greatest extent, ensuring that every precise angular displacement command from the stepper motor can be transmitted to the output mover without delay or loss. Second, the constraint mechanism integrated in the end cover cooperates with the connector, allowing the output mover and gear to slide freely along the axial direction to accommodate the adjustment stroke of the preload, while strictly limiting their overall circumferential rotation. This allows the spiral groove on the end cover to precisely control the relative position with the hydraulic holes on the valve sleeve, achieving accurate metering of the hydraulic circuit, ensuring the linearity and accuracy of the adjustment, and avoiding system malfunction or efficiency loss due to accidental rotation of the output mover. Third, integrating the guiding function into the end cover eliminates the need for additional long guide shafts or complex splined shafts, making the entire hydraulic drive assembly very compact and ideal for applications in motorcycles where installation space is limited.

[0022] Furthermore, a linear bushing is provided between the output mover and the valve sleeve, which provides axial guidance and sealing for the output mover.

[0023] Compared with existing technologies, the technical effects achieved by this solution are as follows: In a hydraulic servo system, the output mover needs to perform precise rotation and axial compound motion within the valve sleeve to achieve accurate control of the fluid flow channel. If the output mover and the valve sleeve metal parts directly mate, the friction pair will inevitably wear after long-term operation, leading to an increase in the clearance between them. By setting a linear bushing between the output mover and the valve sleeve, a low-friction, high-precision guide track can be provided for the axial movement of the output mover, ensuring that the output mover maintains good straightness during repeated movements. This effectively prevents jamming or motion distortion caused by uneven wear, extends the service life of core components such as the output mover and valve sleeve, and improves the reliability and stability of the vibration damper under long-term, harsh operating conditions.

[0024] Furthermore, the piston assembly includes a piston cylinder, and a spring element is concentrically fitted onto the outside of the piston cylinder; the lower end of the spring element is supported by a spring base fixed relative to the piston cylinder; the upper end of the spring element is limited by a spring retainer threadedly connected to the piston cylinder; the spring retainer and the spring base together limit the installation length of the spring element.

[0025] Compared with existing technologies, the technical effects achieved by this solution are as follows: Through the coordinated design of a concentric gap sleeve structure, a spring base support, and a threaded spring retainer, stable control of the spring preload is achieved. Specifically, the spring is sleeved concentrically around the piston cylinder, ensuring the alignment of the spring axis with the piston cylinder axis and avoiding abnormal wear and stress concentration caused by eccentricity. The spring base is fixed relative to the piston cylinder, providing a stable lower support reference for the spring; while the upper end, connected to the piston cylinder by a thread, allows for precise adjustment of its axial position through rotation, thereby changing the distance between the spring retainer and the spring base, i.e., the pre-compression amount of the spring's installation length. The spring retainer and the spring base together constitute a quantifiable, adjustable, and mechanically locked preload limiting mechanism.

[0026] Furthermore, the upper end of the piston cylinder is threadedly connected to the lower end of the end cap. The axial adjustment force pushes the piston cylinder to move axially, thereby changing the axial distance between the spring retainer and the spring base, and thus adjusting the preload of the spring component.

[0027] Compared with existing technologies, the technical effects achieved by this solution are as follows: By connecting the upper end of the piston cylinder to the lower end of the end cap with a threaded connection, a rigid and continuous force transmission chain is constructed. The axial adjustment force generated by the hydraulic drive assembly acts on the end cap, which in turn drives the entire piston cylinder to move axially synchronously through the threaded connection. The axial displacement of the piston cylinder directly changes the axial distance between the spring retainer and the spring base fixed thereon, thereby precisely and linearly changing the installation length of the spring component, i.e., the pre-compression of the spring component, ultimately achieving stepless adjustment of the spring component's preload. Attached Figure Description

[0028] Figure 1 A schematic diagram of the structure of the hydraulic servo helical adjustable preload damper provided in an embodiment of the present invention;

[0029] Figure 2 An exploded view of the hydraulic servo helical adjustable preload damper provided in an embodiment of the present invention;

[0030] Figure 3 This is an assembly diagram of a hydraulic servo-driven adjustable preload damper provided in an embodiment of the present invention.

[0031] Figure 4 for Figure 3 Schematic diagram of the cross section of AA;

[0032] Figure 5 This is a schematic diagram of the structure of the column provided in an embodiment of the present invention;

[0033] Figure 6 This is an exploded view of a portion of the hydraulic drive assembly provided in an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the assembly of the output mover;

[0035] Figure 8 This is a schematic diagram of the initial position and a partial internal structure of the hydraulic servo helical drive principle diagram of the hydraulic servo adjustable preload damper provided in the embodiment of the present invention.

[0036] Figure 9 for Figure 8 A schematic diagram of the central column rotating clockwise along the positive Y-axis and a partial schematic diagram of its internal structure;

[0037] Figure 10 for Figure 8 A schematic diagram showing the movement of the central column along the negative Y-axis and a partial schematic diagram of its internal structure.

[0038] Explanation of reference numerals in the attached figures:

[0039] 100-Piston assembly; 200-Spring component; 300-Hydraulic drive assembly; 2-Motor bracket; 3-Valve sleeve; 4-Stepper motor; 5-Left gear housing; 6-Linear bushing; 7-Piston cylinder; 8-Spring retaining ring; 10-Damping piston; 11-Bottom seal; 12-Piston rod; 13-Spring base; 14-Right gear housing; 15-Column; 16-Connector; 17-Driven gear; 18-End cap; 22-Constraint mechanism; 32-Clearance; 33-Output mover; 34-Helical groove; 35-Pressure bearing surface; 36-Hydraulic hole; 38-Hydraulic pump; 39-Two-position two-way solenoid valve; 40-Drive unit; 41-Flow channel; 42-Driving gear. Detailed Implementation

[0040] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0041] This embodiment provides a hydraulically piloted adjustable preload shock absorber, which is one of the important components of a motorcycle. Its function is to absorb and dissipate the vibration energy generated by the motorcycle due to uneven road surface by using the damping force generated by the shock absorber, thereby ensuring the vehicle's ride comfort, handling stability and driving safety.

[0042] Existing methods for adjusting the preload of motorcycle shock absorbers are either too simplistic and difficult to adapt to complex working conditions, or the systems are complex and limited in integration. There is still a lack of a shock absorber that is compact in structure, fast in response, and easy to implement in engineering.

[0043] In view of the above issues, see Figures 1-7The present invention adopts the following technical solution: a hydraulically piloted adjustable preload damper, comprising: a piston assembly 100 for providing damping and a hydraulic drive assembly 300, wherein a spring element 200 is provided on the outside of the piston assembly 100, one end of the spring element 200 is fixed to the piston assembly 100, and the spring element 200 is used to provide damping force to the piston assembly 100, wherein the other end of the spring element 200 is connected to the hydraulic drive assembly 300, and the hydraulic drive assembly 300 provides axial adjustment force to make the spring element 200 on the piston assembly 100. The preload changes; the hydraulic drive assembly 300 includes a valve sleeve 3 with a pressure control part and an output mover 33. The output mover 33 is installed in the valve sleeve 3 and has a gap 32 with the upper part of the valve sleeve 3 to accommodate hydraulic oil. The output mover 33 is slidably engaged with the valve sleeve 3 and can rotate and move axially relative to the valve sleeve 3. The output mover 33 is provided with a fluid flow channel 41, which connects the gap 32 and the pressure control part. When the output mover 33 rotates, the connecting area of ​​the fluid flow channel 41 changes, thereby causing the output mover 33 to move axially, so as to change the axial adjustment force.

[0044] By connecting the spring element 200 to the hydraulic drive assembly 300, the preload of the spring element 200 can be dynamically and rapidly adjusted using the principle of hydraulic servo. Specifically, the output mover 33 in the hydraulic drive assembly 300 can rotate and move axially within the valve sleeve 3. By changing the communication area of ​​the fluid flow channel 41, the oil pressure acting on the gap 32 between the valve sleeve 3 and the output mover 33 is adjusted, thereby generating a variable axial adjustment force. This axial adjustment force directly changes the preload state of the spring element 200 on the piston assembly 100, allowing the damping characteristics of the shock absorber to be adjusted as needed. This design combines the high precision and large thrust of hydraulic servo control with the controllability of screw drive, achieving linear and continuous adjustment of the preload, improving the adaptability of the shock absorber to different working conditions. By adjusting the preload in real time, the shock absorber can provide soft damping to improve comfort when unloaded, and provide sufficient support to ensure stability and safety when heavily loaded. Secondly, the hydraulic servo-based control method offers fast response and high adjustment precision, which facilitates synergistic optimization between the shock absorber and the entire vehicle system, thereby improving overall performance. Furthermore, this structure integrates the drive and actuator mechanisms within the shock absorber, resulting in a relatively compact design that saves installation space and enhances the overall reliability of the system.

[0045] The working principle of the hydraulically piloted adjustable preload shock absorber is explained below. The working process can be broken down into the following three stages, see below. Figures 8-10In the initial static state, the hydraulic circuit supplies oil through the hydraulic pump 38. The oil enters the gap 32 through the hydraulic hole 36 of the valve sleeve 3. The oil pressure acts on the bearing surface 35 of the column 15, generating an axial thrust in the negative Y-axis direction. At the same time, the spring 200 has an initial preload. This preload is fed back through the piston cylinder 7 and the end cover 18, generating a reverse, upward force. This force is balanced with the axial thrust generated by the oil pressure. The system maintains a static force balance state, the position of the column 15 remains stable, the two-position two-way solenoid valve 39 is in the closed state, and the system maintains pressure closure. Referring to the figure, when the spring preload needs to be increased, the stepper motor 4 drives the driven gear 17 through the driving gear 42, causing the column 15 to rotate. The helical groove 34 of the output mover 33 forms a variable opening with the valve sleeve 3, increasing the oil flow. The pressure in the gap 32 increases, breaking the original balance and pushing the column 15 to move in the negative Y-axis direction. This increased downward thrust pushes the output mover 33 and drives the piston cylinder 7 downward through the end cover 18. The downward movement of the piston cylinder 7 compresses the external spring element 200, thereby increasing the preload of the spring element 200. In this way, the system will automatically reach a new force balance position. At this time, the spring element 200 is compressed to a new length, and the preload increases to adapt to the new load or working condition. The rotation angle of the column 15 determines the final preload magnitude. When it is necessary to reduce the preload or reset the system, the two-position two-way solenoid valve 39 in the hydraulic circuit is energized and switched to the pressure relief state. The oil pressure inside the entire system is quickly relieved, and the downward hydraulic thrust acting on the column 15 disappears or decreases sharply. At this time, the elastic restoring force of the compressed spring 200 is much greater than the remaining hydraulic pressure. This restoring force will push the piston cylinder 7 output mover 33 to move upward back to its original position, thereby reducing the spring preload until it returns to or approaches the initial state.

[0046] Specifically, see Figures 2-5 The output mover 33 is a column 15 with a spiral groove 34. The fluid flow channel 41 passes through the spiral groove 34. The spiral groove 34 cooperates with the pressure control part on the valve sleeve 3. One end face of the column 15 forms a pressure bearing surface 35. The pressurized oil flowing through the spiral groove 34 acts on the pressure bearing surface 35, causing the column 15 to move axially and generate an axial adjustment force. When the column 15 rotates, the communication area between the spiral groove 34 and the pressure control part changes.

[0047] For example, the column 15 can be cylindrical, and the spiral groove 34 can be a single spiral groove, a double spiral groove, or a symmetrical spiral groove. The groove can be considered as a spiral guide rail that runs through the column 15. When high-pressure oil flows in from the pressure control unit, the oil enters this groove. At this time, if the column 15 is forced to rotate, the groove wall will interact with the high-pressure oil, or in other words, the oil pressure will generate a component force along the inclined surface of the groove, pushing the column 15 to move linearly along its axial direction.

[0048] By designing the output mover 33 as a cylinder 15 with a helical groove 34 and cooperating it with the pressure control part on the valve sleeve 3, a highly integrated mechanical and hydraulic conversion mechanism is formed. This design utilizes the geometric characteristics of the helical groove 34 to linearly convert the rotation angle into the flow area, thereby regulating the flow rate and pressure of the oil flowing to the pressure bearing surface 35. The pressurized oil acts on the pressure bearing surface 35 at the end of the cylinder 15, directly converting the hydraulic pressure into the driving force that pushes the cylinder 15 to move axially. This solves the problems of traditional shock absorbers, such as complex structure, large space occupation, long transmission chain, and significant response delay. It enables its effective application in space-constrained scenarios such as motorcycle shock absorbers that require rapid response. Furthermore, the helical pair has good self-locking characteristics. Combined with the mechanical feedback of the spring 200, it can achieve stable automatic return during hydraulic unloading, ensuring that the entire adjustment process is sensitive, stable, and safe, and avoiding preload drift caused by external disturbances or system leakage.

[0049] Specifically, see Figures 1-5 The pressure control unit includes a hydraulic hole 36 and a hydraulic circuit. The hydraulic hole 36 is located on the valve sleeve 3 and is connected to the spiral groove 34. The hydraulic circuit pressurizes or depressurizes the fluid flow channel 41 through the hydraulic hole 36.

[0050] For example, the hydraulic holes 36 can be configured in multiple ways, corresponding to the number of spiral grooves 34.

[0051] Firstly, due to the highly integrated and extremely short path of the fluid flow channel 41, the process of hydraulic oil acting on the pressure bearing surface 35 from pressurization, or from depressurization to the removal of force, is much faster, significantly reducing the system's response time. Simultaneously, it avoids pressure attenuation and fluctuations caused by long pipelines, making the axial displacement control of the output mover 33 more precise, indirectly improving the linearity and accuracy of spring preload adjustment. Secondly, this compact integrated design reduces potential leakage points and cavity volume in the system, helping to improve the rigidity of the hydraulic system. This allows the system to more effectively suppress pressure fluctuations when dealing with rapidly changing loads, ensuring that the shock absorber provides stable damping force under various operating conditions. Thirdly, through the coordinated design of the hydraulic port 36 and the hydraulic circuit, key pressure control functions are integrated inside the valve sleeve 3, which facilitates the miniaturization and modularization of the entire hydraulic drive assembly 300, making it easier to install on platforms with limited installation space, such as motorcycles. Furthermore, the reduction in the number of components and the simplification of connecting pipelines also reduce the risk of failures due to loose joints, pipe wall wear, etc., improving the overall reliability of the system.

[0052] Specifically, see Figure 2The hydraulic circuit includes a hydraulic pump 38 and a two-position two-way solenoid valve 39. The hydraulic pump 38 is used to provide pressurized oil. The outlet of the hydraulic pump 38 is connected to the oil inlet of the two-position two-way solenoid valve 39. The working oil port of the two-position two-way solenoid valve 39 is connected to the hydraulic port 36. The two-position two-way solenoid valve 39 is used to control the on / off state of the hydraulic circuit.

[0053] Efficient and precise hydraulic circuit control is achieved through direct coupling between hydraulic pump 38 and 2-position 2-way solenoid valve 39. Hydraulic pump 38, as the power source, continuously supplies pressurized hydraulic fluid, and its outlet is directly connected to the inlet of 2-position 2-way solenoid valve 39. This solenoid valve, as the core control switch, has its working port directly connected to the hydraulic port 36 of the actuator. When the solenoid valve is energized and opened, pressurized hydraulic fluid flows through, driving the output mover 33 to move axially; when the solenoid valve is de-energized and closed, the hydraulic circuit is cut off, and the system can achieve pressure holding or unloading according to the design.

[0054] Specifically, see Figure 1 and Figure 5 The hydraulic drive assembly 300 also includes a drive unit 40, which is connected to the output mover 33 for driving the output mover 33 to rotate.

[0055] By introducing the drive unit 40 and connecting it to the output mover 33, the drive unit 40, valve sleeve 3, and pressure control unit of the hydraulic drive assembly 300 can be modularly designed and arranged. This improves the space utilization of the hydraulic drive assembly 300 and makes the entire hydraulic drive assembly 300 structure more compact.

[0056] Specifically, see Figures 1-5 The drive unit 40 includes a stepper motor 4 and a drive gear 42 driven by the stepper motor 4; the end of the output mover 33 is fixed to the driven gear 17, and the driven gear 17 meshes with the drive gear 42.

[0057] For example, the driven gear 17 is a sector gear that meshes with the armature of the driving gear 42 of the stepper motor 4. The stepper motor 4 will drive the sector gear to rotate, thereby reducing speed and amplifying torque.

[0058] Stepper motor 4 receives pulse signals from the vibration damper control unit. Each pulse corresponds to a fixed rotation angle, achieving high-precision positioning under open-loop control without the need for additional feedback sensors. Through gear transmission and possible speed reduction and torque amplification, the precise rotation angle of stepper motor 4 is ultimately converted into an equally precise rotation angle of output mover 33, thereby accurately adjusting the opening of fluid channel 41 and achieving stepless or graded adjustment of damping force. Simultaneously, the meshing transmission between drive gear 42 and driven gear 17 allows for a lateral arrangement of the motor, fully utilizing the narrow space on the side of the vibration damper, achieving a high degree of integration and modularity.

[0059] Specifically, see Figures 1-5 The hydraulic drive assembly 300 also includes: a connector 16 and an end cap 18 with a constraint mechanism 22. The connector 16 is fixedly connected to the end of the driven gear 17 and the output mover 33, so that the rotation of the driven gear 17 can drive the output mover 33 to rotate synchronously. The constraint mechanism 22 cooperates with the connector 16 to allow the whole consisting of the output mover 33 and the driven gear 17 to move axially and restrict the whole circumferential rotation.

[0060] For example, connector 16 can be set with mushroom-shaped screws, and the constraint structure is set as a slot on end cap 18. The limit rotation angle of the sector gear is limited by the slot. The column 15 and the sector gear are fixed by mushroom-head screws, and the sector gear will drive the column 15 to rotate in the slot. At the same time, the mushroom-shaped screws of connector 16 can be embedded in the slot on end cap 18, so that the two are fixed like a groove, which can realize a push-pull effect.

[0061] For example, the valve sleeve 3 is fixed to the end cover 18 by the motor bracket 2, the left gear housing 5, and the right gear housing 14, further integrating the structure.

[0062] First, the rigid connection between the output end of the driven gear 17 and the drive end of the output mover 33 by the connector 16 minimizes backlash in the transmission chain, ensuring that every precise angular displacement command from the stepper motor 4 is transmitted to the output mover 33 without delay or loss. Second, the constraint mechanism 22 integrated within the end cover 18 cooperates with the connector 16, allowing the output mover 33 and the gear as a whole to slide freely axially to accommodate the adjustment stroke of the preload force, while strictly limiting their overall circumferential rotation. This allows the spiral groove 34 on it to precisely control its relative position to the hydraulic hole 36 on the valve sleeve 3, achieving accurate metering of the hydraulic oil circuit, ensuring the linearity and accuracy of the adjustment, and avoiding system malfunction or efficiency loss due to accidental rotation of the output mover 33. Third, integrating the guiding function within the end cover 18 eliminates the need for an additional long guide shaft or complex spline shaft, making the entire hydraulic drive assembly 300 very compact, ideal for applications in motorcycles where installation space is limited.

[0063] Specifically, see Figures 1-5 A linear bushing 6 is provided between the output actuator 33 and the valve sleeve 3, which provides axial guidance and sealing for the output actuator 33.

[0064] For example, the bushing is made of a material with certain elasticity or self-lubricating properties, such as polytetrafluoroethylene, graphite, nylon or bronze. When it is pressed into the inner wall of the valve sleeve 3 with an interference fit and forms a tight gap 32 with the output mover 33, it can effectively block the leakage of high pressure oil along the fit gap 32.

[0065] In a hydraulic servo system, the output mover 33 needs to perform precise rotation and axial compound motion within the valve sleeve 3 to achieve precise control of the fluid flow channel 41. If the output mover 33 and the valve sleeve 3 metal parts directly mate, the friction pair will inevitably wear after long-term operation, leading to an increase in the mating clearance 32. By setting a linear bushing 6 between the output mover 33 and the valve sleeve 3, a low-friction, high-precision guide track can be provided for the axial movement of the output mover 33, ensuring that the output mover 33 maintains good straightness during repeated movements. This effectively prevents jamming or motion distortion caused by uneven wear, extends the service life of core components such as the output mover 33 and the valve sleeve 3, and improves the reliability and stability of the shock absorber under long-term, harsh operating conditions.

[0066] Specifically, see Figures 1-5 The piston assembly 100 includes a piston cylinder 7, and a spring member 200 is sleeved on the outside of the piston cylinder 7 with a concentric gap 32. The lower end of the spring member 200 is supported by a spring base 13 that is fixed relative to the piston cylinder 7. The upper end of the spring member 200 is limited by a spring retainer 8 that is threadedly connected to the piston cylinder 7. The spring retainer 8 and the spring base 13 together limit the installation length of the spring member 200.

[0067] Through the coordinated design of the concentric gap 32 sleeve structure, the spring base 13 support and the threaded connection spring retainer 8, the preload of the spring component 200 is stably controlled.

[0068] For example, the piston assembly 100 further includes a damping piston 10, a piston rod 12, and a bottom seal 11. The bottom seal 11 is interference-fitted with the bottom end of the piston cylinder 7 to form a sealed cavity within the piston cylinder 7. The damping piston 10 is disposed within the sealed cavity and slides within the piston cylinder 7, for axial movement within the cavity to provide vibration damping. One end of the piston rod 12 is threadedly connected to the damping piston 10, and both move accordingly. The other end of the piston rod 12 extends out of the bottom seal 11 for connection to the outside. When external vibration is transmitted through the piston rod 12, driving the damping piston 10 to reciprocate within the sealed piston cylinder 7 filled with hydraulic oil, the significant fluid resistance generated by the oil passing through the throttling orifice on the damping piston 10 dissipates energy, thus achieving the purpose of damping vibration.

[0069] Specifically, the spring element 200 is fitted onto the outside of the piston cylinder 7 with a concentric gap 32, ensuring the coincidence of the spring axis and the piston cylinder 7 axis, and avoiding abnormal wear and stress concentration caused by eccentricity. The spring base 13 is fixed relative to the piston cylinder 7, providing a stable lower support reference for the spring element 200; while the upper end of the spring retainer 8 is threadedly connected to the piston cylinder 7, and its axial position can be precisely adjusted by rotation, thereby changing the gap between the spring retainer 8 and the spring base 13, i.e., the installation length pre-compression amount of the spring element 200. The spring retainer 8 and the spring base 13 together constitute a quantitatively adjustable and mechanically locked preload limiting mechanism.

[0070] Specifically, see Figures 1-5 The upper end of the piston cylinder 7 is threadedly connected to the lower end of the end cover 18. The axial adjustment force pushes the piston cylinder 7 to move axially, thereby changing the axial distance between the spring retainer 8 and the spring base 13, and realizing the adjustment of the preload of the spring component 200.

[0071] By threading the upper end of the piston cylinder 7 to the lower end of the end cap 18, a rigid and continuous force transmission chain is constructed. The axial adjustment force generated by the hydraulic drive assembly 300 acts on the end cap 18, thereby driving the entire piston cylinder 7 to move axially synchronously through this threaded connection. The axial displacement of the piston cylinder 7 directly changes the axial distance between the spring retainer 8 fixed thereon and the spring base 13, thus precisely and linearly changing the installation length of the spring component 200, i.e., the pre-compression of the spring component 200, ultimately achieving stepless adjustment of the preload of the spring component 200.

[0072] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A hydraulic pilot operated adjustable pre-load damper, characterized by, The hydraulic pilot type adjustable pre-tightening shock absorber comprises: A piston assembly for providing damping resistance, the piston assembly is externally provided with a spring member, one end of the spring member is fixed on the piston assembly, the spring member is used for providing damping force to the piston assembly, wherein the other end of the spring member is connected with a hydraulic drive assembly, the hydraulic drive assembly provides an axial adjustment force to change the pre-tightening force of the spring member on the piston assembly; The hydraulic drive assembly comprises a valve sleeve provided with a pressure control part and an output driver, and a drive unit, the drive unit is in transmission connection with the output driver for driving the output driver to rotate, the output driver is installed in the valve sleeve, the upper end of the output driver and the upper part of the valve sleeve have a gap for containing hydraulic oil, the output driver is in sliding fit with the valve sleeve and can rotate and axially move relative to the valve sleeve, the output driver is provided with a flow channel, the flow channel communicates the gap and the pressure control part; The drive unit comprises a stepper motor and a driving gear driven by the stepper motor, the end of the output driver is fixed with a driven gear, the driven gear is in mesh with the driving gear; A connecting member, the connecting member fixedly connects the driven gear and the end of the output driver, so that the rotation of the driven gear can drive the output driver to rotate synchronously; An end cover provided with a constraint mechanism, the constraint mechanism cooperates with the connecting member to allow the whole of the output driver and the driven gear to axially move and restrict the whole to rotate circumferentially; Wherein, when the output driver rotates, the communication area of the flow channel changes, and then the output driver axially moves to change the axial adjustment force.

2. The hydraulic pilot-operated adjustable pre-load damper of claim 1, wherein, The output driver is a column provided with a spiral groove, the flow channel passes through the spiral groove, the spiral groove cooperates with the pressure control part, one end face of the column constitutes a pressure bearing surface, the pressurized oil flowing through the spiral groove acts on the pressure bearing surface to make the column axially move to generate the axial adjustment force; Wherein, when the column rotates, the communication area of the spiral groove and the pressure control part changes.

3. The hydraulic pilot-operated adjustable pre-load damper of claim 2, wherein, The pressure control part comprises a hydraulic hole and a hydraulic circuit, the hydraulic hole is arranged on the valve sleeve, the hydraulic hole communicates the spiral groove, the hydraulic circuit pressurizes or depressurizes the flow channel through the hydraulic hole.

4. The hydraulic pilot-operated adjustable pre-load damper of claim 3, wherein, The hydraulic circuit comprises a hydraulic pump and a two-position two-way electromagnetic valve, the hydraulic pump is used for providing the pressurized oil, the outlet of the hydraulic pump is connected with the oil inlet of the two-position two-way electromagnetic valve, the working oil port of the two-position two-way electromagnetic valve is connected with the hydraulic hole, and the two-position two-way electromagnetic valve is used for controlling the on-off state of the hydraulic circuit.

5. The hydraulic pilot-operated adjustable pre-load damper of claim 1, wherein, A linear bushing is arranged between the output driver and the valve sleeve, the linear bushing provides axial guidance and sealing for the output driver.

6. The hydraulic pilot-operated adjustable pre-load damper of claim 5, wherein, The piston assembly comprises a piston cylinder, and the spring member is arranged outside the piston cylinder in a concentric gap manner. The lower end of the spring member is supported by a spring base fixed relative to the piston cylinder; the upper end of the spring member is limited by a spring retainer threadedly connected to the piston cylinder; the spring retainer and the spring base jointly define the installation length of the spring member.

7. The hydraulic pilot-operated adjustable pre-load damper of claim 6, wherein, The upper end of the piston cylinder is threadedly connected to the lower end of the end cover, the axial adjustment force pushes the piston cylinder to move axially, thereby changing the axial distance between the spring retainer and the spring base, and realizing the adjustment of the pre-tightening force of the spring member.

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