A stiffness adjusting device for a shock absorber

Abstract

The utility model relates to shock absorber technical field, more particularly, relate to a kind of stiffness adjusting device of shock absorber.Stiffness adjusting device includes: piston assembly and hydraulic drive assembly, piston assembly outside is equipped with spring piece, spring piece one end is fixed on piston assembly, and spring piece is used to provide damping force for piston assembly, wherein spring piece other end is connected with hydraulic drive assembly, and hydraulic drive assembly includes being equipped with hydraulic part, valve sleeve, output runner and drive part, output runner is equipped with liquid flow passage, and liquid flow passage is communicated hydraulic part, and hydraulic part drives output runner to move in valve sleeve axial direction, and drive part drives output runner to rotate around the axis of output runner, and the communication area of liquid flow passage changes, so that output runner generates axial displacement, to adjust the pre-tightening force of spring piece on piston assembly.The problem solved by the utility model is to provide a kind of compact structure, response fast, easily engineering implementation and effectively improve the shock absorber of vehicle adaptability.

Description

Technical Field

[0001] This utility model relates to the field of vibration damper technology, and more specifically, to a vibration damper stiffness adjustment device. 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, using lead screws or gears to quickly adjust spring preload. However, such motor-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-driven solutions not only increase system costs but also present 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. Utility Model Content

[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] This utility model adopts the following technical solution: a stiffness adjustment device for a vibration damper, the stiffness adjustment device includes: a piston assembly for providing vibration damping and a hydraulic drive assembly, a spring is provided on the outside of the piston assembly, one end of the spring is fixed on the piston assembly, the spring is used to provide damping force to the piston assembly, wherein the other end of the spring is connected to the hydraulic drive assembly, the hydraulic drive assembly includes a hydraulic part, a valve sleeve, an output mover and a drive part, the output mover is installed in the valve sleeve, the output mover is slidably engaged with the valve sleeve, the output mover is provided with a fluid flow channel, the fluid flow channel is connected to the hydraulic part, the hydraulic part drives the output mover to move axially in the valve sleeve, the drive part drives the output mover to rotate around the axis of the output mover, and the lower end of the output mover is connected to the spring; When the output mover rotates, the connecting area of ​​the fluid flow channel changes, which in turn causes the output mover to generate axial displacement, thereby adjusting the preload of the spring component on the piston assembly.

[0009] By connecting the spring element to the hydraulic drive assembly, the preload of the spring element is dynamically and rapidly adjusted using the principle of hydraulic servo. Specifically, the output mover in the hydraulic drive assembly can rotate within the valve sleeve, changing the connectivity area of ​​the fluid flow channel, thereby altering the oil pressure between the valve sleeve and the output mover. This causes the output mover to move axially, changing the preload state of the spring element on the piston assembly, allowing the damping characteristics of the shock absorber to be adjusted as needed. This design combines the high precision and high thrust of hydraulic servo control with the controllability of screw transmission, achieving linear and continuous adjustment of the preload. This improves the shock absorber's adaptability to different operating 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 loads. Secondly, the hydraulic servo-based control method offers fast response 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 mechanisms 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, there is a gap between the upper end of the output mover and the upper part of the valve sleeve, and the fluid flow channel connects the hydraulic part and the gap.

[0011] The gap between the upper end of the output mover and the upper part of the valve sleeve provides a pressure-bearing space for the hydraulic oil to act on the output mover. When the hydraulic unit supplies oil to the fluid flow channel, the oil enters this gap and exerts pressure on the upper end face of the output mover, thereby providing driving force for the axial movement of the output mover.

[0012] Furthermore, the output mover is a column with a spiral groove, the fluid flow channel passes through the spiral groove, the spiral groove cooperates with the hydraulic part, one end face of the column forms a pressure bearing surface, and the pressurized oil flowing through the spiral groove acts on the pressure bearing surface to make the column move axially. When the column rotates, the area of ​​communication between the spiral groove and the hydraulic part changes.

[0013] By designing the output mover as a column with helical grooves and cooperating with the hydraulic part on the valve sleeve, a highly integrated mechanical and hydraulic conversion mechanism is formed. This design utilizes the geometric characteristics of the helical grooves 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, making it effective in applications such as motorcycle shock absorbers where space is limited and rapid response is required.

[0014] Furthermore, the hydraulic 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 is used to pressurize or depressurize the fluid flow channel through the hydraulic port.

[0015] Firstly, due to the highly integrated and extremely short flow channels, the hydraulic oil's process from pressurization to application to the pressure-bearing surface, or from depressurization to removal of force, is much faster, significantly reducing the system's response time. Simultaneously, it avoids pressure attenuation and fluctuations caused by long pipelines, resulting in more precise axial displacement control of the output mover, 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, 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. Thirdly, the coordinated design of hydraulic orifices and 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 lowers the risk of failures due to loose joints, pipe wall wear, etc., improving the overall reliability of the system.

[0016] 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.

[0017] Efficient and precise hydraulic circuit control is achieved through direct coupling between 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 can pass 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.

[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] The stepper motor 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 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 vibration 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] Firstly, the connecting piece rigidly connects the output end of the driven gear to the drive end of the output mover, minimizing backlash in the transmission chain and ensuring that every precise angular displacement command from the stepper motor is transmitted to the output mover without delay or loss. Secondly, the constraint mechanism integrated within the end cover works in conjunction with the connecting piece, allowing the output mover and gear to slide freely axially to accommodate the adjustment stroke for preload, while strictly limiting their overall circumferential rotation. This allows the helical grooves on the output mover to precisely control their relative position to the hydraulic holes on the valve sleeve, achieving accurate metering of the hydraulic circuit, ensuring linearity and accuracy of adjustment, and preventing system malfunction or efficiency loss due to accidental rotation of the output mover. Thirdly, integrating the guiding function within 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] In hydraulic servo systems, the output mover needs to perform precise rotational and axial compound motion within the valve sleeve to achieve accurate control of the fluid flow channel. If the output mover directly mates with the valve sleeve's metal parts, wear will inevitably occur on the friction pair after long-term operation, leading to an increase in the clearance between them. By installing 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] Through the coordinated design of a concentric clearance 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] By threading the upper end of the piston cylinder to the lower end of the end cap, 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 1A schematic diagram of the structure of the hydraulic servo spiral adjustable preload damper provided in the embodiment of this utility model; Figure 2 An exploded view of the hydraulic servo helical adjustable preload damper provided in this embodiment of the utility model; Figure 3 An assembly diagram of the hydraulic servo helical adjustable preload damper provided in this embodiment of the utility model; Figure 4 for Figure 3 Schematic diagram of the cross section of AA; Figure 5 A schematic diagram of the structure of the column provided in this embodiment of the utility model; Figure 6 An exploded view of a portion of the hydraulic drive assembly provided in an embodiment of this utility model; Figure 7 This is a schematic diagram of the assembly of the output mover; Figure 8 The initial position schematic diagram and partial internal structure schematic diagram of the hydraulic servo spiral adjustable preload damper provided in the embodiment of this utility model are shown in the hydraulic servo spiral drive principle diagram. 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; 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.

[0029] Explanation of reference numerals in the attached figures: 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

[0030] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0031] This embodiment provides a stiffness adjustment device. The shock absorber 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.

[0032] 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.

[0033] In view of the above issues, see Figures 1-7 The present invention adopts the following technical solution: a stiffness adjustment device, comprising: a piston assembly 100 for providing vibration damping and a hydraulic drive assembly 300, wherein a spring member 200 is provided on the outside of the piston assembly 100, one end of the spring member 200 is fixed on the piston assembly 100, and the spring member 200 is used to provide damping force to the piston assembly 100, wherein the other end of the spring member 200 is connected to the hydraulic drive assembly 300, the hydraulic drive assembly 300 includes a hydraulic part, a valve sleeve 3, an output mover 33 and a drive part 40, the output mover 33 is installed in the valve sleeve 3, the output mover 33 is slidably engaged with the valve sleeve 3, the output mover 33 is provided with a fluid flow channel 41, the fluid flow channel 41 is connected to the hydraulic part, the hydraulic part drives the output mover 33 to move axially within the valve sleeve 3, the drive part 40 drives the output mover 33 to rotate around the axis of the output mover 33, and the lower end of the output mover 33 is connected to the spring member 200; When the output mover 33 rotates, the connecting area of ​​the fluid flow channel 41 changes, which causes the output mover 33 to move axially to adjust the preload of the spring member 200 on the piston assembly 100.

[0034] 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 hydraulic servo principle. Specifically, the output mover 33 in the hydraulic drive assembly 300 can rotate within the valve sleeve 3, changing the communication area of ​​the fluid channel 41, thereby changing the oil pressure between the valve sleeve 3 and the output mover 33. This causes the output mover 33 to move axially, changing 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 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 unit 40 and the actuator inside the shock absorber, resulting in a relatively compact structure that helps save installation space and improve the overall reliability of the system.

[0035] Further, see Figures 4-7 There is a gap 32 between the upper end of the output actuator 33 and the upper part of the valve sleeve 3, and the fluid flow channel 41 connects the hydraulic part and the gap 32.

[0036] The gap 32 between the upper end of the output mover 33 and the upper part of the valve sleeve 3 provides a pressure-bearing space for the hydraulic oil to act on the output mover 33. When the hydraulic unit supplies oil to the fluid flow channel 41, the oil will enter the gap 32 and generate pressure on the upper end face of the output mover 33, thereby providing driving force for the axial movement of the output mover 33.

[0037] The working principle of the stiffness adjustment device 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.

[0038] 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 hydraulic 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 hydraulic part changes.

[0039] 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 hydraulic 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.

[0040] By designing the output mover 33 as a cylinder 15 with a helical groove 34 and cooperating with the hydraulic 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 where rapid response is required. 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.

[0041] Specifically, see Figure 4 The hydraulic part 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 is used to pressurize or depressurize the fluid flow channel 41 through the hydraulic hole 36.

[0042] For example, the hydraulic holes 36 can be configured in multiple ways, corresponding to the number of spiral grooves 34.

[0043] 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.

[0044] Specifically, see Figure 4The 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.

[0045] 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.

[0046] Specifically, see Figures 4-7 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.

[0047] 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.

[0048] 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.

[0049] Specifically, see Figures 4-7 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] Specifically, see Figures 4-7 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.

[0054] 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.

[0055] 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.

[0056] Specifically, see Figures 4-7 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.

[0057] 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.

[0058] For example, the piston assembly 100 also 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 follow each other; 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 energy is consumed due to the huge fluid resistance generated by the oil passing through the throttling orifice on the damping piston 10, thus achieving the purpose of damping vibration.

[0059] Specifically, see Figures 2-7The 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.

[0060] Specifically, see Figures 2-7 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.

[0061] 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.

[0062] Although 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 present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A stiffness adjustment device for a vibration damper, characterized in that, The stiffness adjustment device includes: A piston assembly for providing vibration damping has a spring component on its exterior. One end of the spring component is fixed to the piston assembly, and the other end of the spring component is connected to a hydraulic drive assembly. The spring component is used to provide damping force to the piston assembly. The hydraulic drive assembly includes: a hydraulic unit, a valve sleeve, an output mover, and a drive unit. The output mover is installed inside the valve sleeve and is slidably engaged with the valve sleeve. The output mover has a fluid flow channel that communicates with the hydraulic unit. The hydraulic unit drives the output mover to move axially within the valve sleeve, and the drive unit drives the output mover to rotate around its axis. The lower end of the output mover is connected to the spring member. When the output mover rotates, the connecting area of ​​the fluid flow channel changes, thereby causing the output mover to generate axial displacement, so as to adjust the preload of the spring on the piston assembly.

2. The stiffness adjustment device according to claim 1, characterized in that, There is a gap between the upper end of the output actuator and the upper part of the valve sleeve, and the fluid flow channel connects the hydraulic part and the gap.

3. The stiffness adjustment device according to claim 2, characterized in that, The output mover is a column with a spiral groove. The fluid channel passes through the spiral groove. The spiral groove cooperates with the hydraulic part. The upper 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. When the column rotates, the communication area between the spiral groove and the hydraulic unit changes.

4. The stiffness adjustment device according to claim 3, characterized in that, The hydraulic unit includes a hydraulic port and a hydraulic circuit. The hydraulic port is located on the valve sleeve and communicates with the spiral groove. The hydraulic circuit is used to pressurize or depressurize the fluid flow channel through the hydraulic port.

5. The stiffness adjustment device according to claim 4, characterized in that, The hydraulic circuit includes a hydraulic pump and a two-position two-way solenoid valve. The hydraulic pump is used to provide the pressurized oil. The outlet of the hydraulic pump is connected to the inlet of the two-position two-way solenoid valve. The working port of the two-position two-way solenoid valve is connected to the hydraulic port. The two-position two-way solenoid valve is used to control the on / off state of the hydraulic circuit.

6. The stiffness adjustment device according to any one of claims 1-5, characterized in that, 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.

7. The stiffness adjustment device according to claim 6, characterized in that, The hydraulic drive assembly also includes: A connector that fixes the driven gear to the end of the output mover, so that the rotation of the driven gear can drive the output mover to rotate synchronously; An end cap with a constraint mechanism is provided, which cooperates with the connecting member to allow the entire assembly consisting of the output mover and the driven gear to move axially and restrict the circumferential rotation of the entire assembly.

8. The stiffness adjustment device according to claim 7, characterized in that, A linear bushing is provided between the output actuator and the valve sleeve, and the linear bushing provides axial guidance and sealing for the output actuator.

9. The stiffness adjustment device according to claim 8, characterized in that, The piston assembly includes a piston cylinder, and the spring is sleeved on the outside of the piston cylinder with a concentric clearance. The lower end of the spring is supported by a spring base fixed relative to the piston cylinder; the upper end of the spring 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.

10. The stiffness adjustment device according to claim 9, characterized in that, 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 realizing the adjustment of the preload of the spring component.

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