Shock absorber with adjustable rigidity

Abstract

The invention relates to the technical field of hydraulic transmission, in particular to a rigidity-adjustable shock absorber which specifically comprises a barrel and a first spring, and one end of the first spring is fixed outside the barrel; the other end of the first spring is fixed outside the electro-hydraulic actuator, the electro-hydraulic actuator comprises a connecting part and an actuating part, and the connecting part is arranged at one end of the actuating part; the piston rod is arranged in the cylinder in a sliding mode in the axial direction, one end of the piston rod extends out of the cylinder to be connected with the connecting part, the other end of the piston rod is provided with a piston valve plate part and a magnetostriction part, and a second spring is arranged between the magnetostriction part and the piston valve plate part and abuts against the magnetostriction part and the piston valve plate part; when the magnetostriction part generates axial telescopic deformation due to the change of a magnetic field, the pre-tightening force of the second spring is changed, and when the actuating part axially moves in the electro-hydraulic actuator, the connecting part drives the piston rod to move, and then the pre-tightening force of the first spring is adjusted. The rigidity of the main spring and the rigidity of the valve plate of the shock absorber are continuously adjusted.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of hydraulic transmission, in particular to a shock absorber with adjustable stiffness. BACKGROUND

[0002] The stiffness of the shock absorber directly affects the support capacity and vibration transmission characteristics of the vehicle suspension, and the external spring pre-tightening force determines the stiffness. Adjusting the pre-tightening force can achieve active control of the overall stiffness of the shock absorber.

[0003] Existing shock absorbers with adjustable stiffness mostly use a motor-driven mechanical transmission mechanism to change the installation position of the spring, thereby adjusting the pre-tightening force. Specifically, the motor output shaft converts rotary motion into linear motion through gear or screw transmission, driving the spring support to move axially. However, such a mechanical transmission structure has transmission gaps and frictional resistance, resulting in a hysteresis in the adjustment response, and it is difficult to achieve continuous stepless changes in the pre-tightening force. At the same time, the mechanical transmission components are prone to wear in the vehicle vibration environment, and the adjustment accuracy decreases after long-term use, which cannot stably guarantee the suspension support requirements.

[0004] In terms of piston valve damping adjustment, the compression stroke damping of the shock absorber is determined by the opening pressure of the piston valve, which is directly controlled by the stiffness and pre-tightening force of the valve spring. Existing technologies mostly use valve springs with fixed stiffness, resulting in non-adjustable damping characteristics. Some solutions use multi-stage stiffness springs or electromagnetic valves to control the bypass oil path, but multi-stage springs can only achieve a limited number of discrete stiffness gears, which cannot meet the precise damping adjustment requirements in wide working conditions. The electromagnetic valve solution requires the addition of complex oil paths and electromagnetic control elements, which not only increases the structure size, but also has the problem of high energy consumption.

[0005] Therefore, the existing technologies have the problems of response hysteresis, difficulty in stepless adjustment, and easy attenuation of accuracy in adjusting the basic stiffness of the shock absorber, and the problems of complex structure, high energy consumption, and poor adjustment stability in adjusting the compression stroke damping. SUMMARY

[0006] The present disclosure provides a shock absorber with compact structure, fast response, and the ability to achieve active adjustment of the stiffness of the shock absorber and precise adjustment of the damping force.

[0007] The adjustable stiffness damper comprises a cylinder and a first spring, one end of the first spring is fixed to the outside of the cylinder; an electro-hydraulic actuator, the other end of the first spring is fixed to the outside of the electro-hydraulic actuator, the electro-hydraulic actuator comprises a connecting part and an actuating part, the connecting part is arranged at one end of the actuating part; a piston rod, which is arranged in the cylinder in an axial sliding manner, and one end of the piston rod extends out of the cylinder and is connected to the connecting part, the other end of the piston rod is provided with a piston valve piece part and a magnetostrictive part, a second spring is arranged between the magnetostrictive part and the piston valve piece part, and the second spring is in abutment with the magnetostrictive part and the piston valve piece part respectively; wherein when the magnetostrictive part is subjected to axial expansion and contraction deformation caused by the change of the magnetic field, the pre-tightening force of the second spring changes, when the actuating part moves axially in the electro-hydraulic actuator, the connecting part drives the piston rod to move, and then the pre-tightening force of the first spring is adjusted.

[0008] Further, the magnetostrictive part comprises a magnetostrictive column made of a giant magnetostrictive material, the magnetostrictive column is provided with a first shaft hole, the first shaft hole cooperates with the piston rod to assemble the magnetostrictive column on the piston rod.

[0009] Further, the magnetostrictive part further comprises a coil winding, the coil winding is arranged on one side of the magnetostrictive column, and is used to generate a variable magnetic field to drive the magnetostrictive column to occur axial expansion and contraction deformation.

[0010] Further, the magnetostrictive part further comprises a mounting column, the magnetostrictive column is connected with the mounting column, the mounting column is provided with a mounting ring groove, and the coil winding is sleeved in the mounting ring groove in a ring shape, the mounting column is further provided with a second shaft hole, the second shaft hole cooperates with the piston rod to assemble the mounting column on the piston rod.

[0011] Further, the piston valve piece part comprises a valve piece and a fixed piston, the fixed piston is fixed to the end of the piston rod, the fixed piston is provided with a through hole, the valve piece is arranged on the side of the fixed piston close to the second spring and blocks the through hole, and the valve piece is opened under the action of the oil pressure to overcome the pre-tightening force of the second spring.

[0012] Further, the electro-hydraulic actuator comprises a mounting cylinder, which has a receiving cavity, one end of the mounting cylinder is provided with an end cover, and the other end is opened to allow the connecting part to extend out; an actuating piston, which is arranged in the receiving cavity in a sliding manner, and divides the receiving cavity into an upper cavity and a lower cavity; the connecting part is an actuating rod, one end of the connecting part is fixedly connected with the actuating piston, and the other end of the connecting part extends out of the mounting cylinder and is connected with the piston rod.

[0013] Further, the actuating piston comprises a first oil port communicating with the upper cavity and a second oil port communicating with the lower cavity; an inner rotor and a rotor seat in meshing, the inner rotor is eccentrically installed on the rotor seat, the rotor seat is provided with a driving member for driving the inner rotor to rotate; wherein when the inner rotor rotates, a liquid oil chamber with a variable volume is formed between the inner rotor and the rotor seat, and the liquid oil chamber communicates with the upper cavity and the lower cavity through the first oil port and the second oil port.

[0014] Further, the actuating piston further comprises a pressure maintaining mechanism, and the oil chamber is communicated with the first oil port and the second oil port through the pressure maintaining mechanism.

[0015] Further, the actuating piston comprises a mounting groove and a positioning piece, the rotor seat is mounted in the mounting groove, and the positioning piece is clamped between the rotor seat and the mounting groove to prevent the rotor seat from rotating with the mounting groove.

[0016] Further, a buffer pad is arranged on the side of the actuating piston in contact with the lower cavity, the buffer pad protrudes from the actuating piston, and the buffer pad is used to provide buffering.

[0017] Compared with the prior art, the technical effect of the scheme is that: in view of the defects of the existing motor-driven mechanical transmission for adjusting the pre-tightening force of the spring, the scheme directly connects the electro-hydraulic actuator with the piston rod, uses the axial movement of the actuating part to drive the piston rod to slide synchronously, and then directly adjusts the pre-tightening force of the first spring; the structure does not need intermediate transmission components such as gears and screws, thus eliminating the transmission gap and frictional resistance from the root, realizing non-hysteresis and continuous stepless adjustment of the pre-tightening force of the first spring, and avoiding the wear problem of the mechanical transmission components, thus ensuring the stability of the adjustment accuracy of the shock absorber during long-term use.

[0018] In view of the inaccurate and complex structure of the existing valve piece damping adjustment, the scheme sets a magnetostrictive part at the end of the piston rod, changes the magnetic field strength by adjusting the current of the electromagnetic coil, and then drives the axial expansion and contraction deformation of the super-magnetostrictive material in the magnetostrictive part; the expansion and contraction deformation directly acts on the second spring between the magnetostrictive part and the piston valve piece part, realizes accurate adjustment of the stiffness of the second spring, and then controls the opening pressure of the piston valve piece, and finally changes the damping size of the compression stroke of the shock absorber. The adjustment method does not need to add complex bypass oil circuit and multi-stage spring, and has simple structure, low energy consumption, fast response speed, high adjustment accuracy, and can flexibly adapt to the damping demand under different working conditions.

[0019] The scheme realizes independent and accurate adjustment of the stiffness and compression stroke damping of the shock absorber: the pre-tightening force of the first spring is adjusted by the electro-hydraulic actuator, the basic support stiffness of the shock absorber can be flexibly changed to meet the different support requirements of the vehicle suspension; the stepless and accurate adjustment of the compression stroke damping is realized by the magnetostrictive part combined with the second spring, and the transmission of vibrations of different amplitudes is effectively suppressed. The two can be independently controlled according to the actual driving conditions without forced linkage, which not only simplifies the control logic, but also can be targeted to adapt to various road excitations, and improves the support and comfort of vehicle driving.

[0020] In addition, the piston rod is assembled in the cylinder in axial sliding, the magnetostrictive part, the second spring and the piston valve piece part are integrated in the end of the piston rod, the electro-hydraulic actuator is directly connected with the piston rod, the overall structure layout is compact and convenient to install, and can adapt to the limited installation space of the vehicle suspension system; meanwhile, the connection of each component is reliable, and can adapt to the complex vibration environment in the vehicle driving process, and has strong long-term use stability. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structure schematic diagram of a shock absorber in specific embodiments of the present application.

[0022] Figure 2 It is a sectional schematic diagram of a shock absorber in specific embodiments of the present application.

[0023] Figure 3 It is an assembly structure schematic diagram of the magnetostrictive part and the piston valve piece part in specific embodiments of the present application.

[0024] Figure 4 It is a structure schematic diagram of the magnetostrictive part in specific embodiments of the present application.

[0025] Figure 5 It is a structure schematic diagram of the magnetostrictive part in specific embodiments of the present application.

[0026] Figure 6 It is a structure schematic diagram of the fixed piston in specific embodiments of the present application.

[0027] Figure 7 It is a structure schematic diagram of the electro-hydraulic actuator in specific embodiments of the present application.

[0028] Figure 8 It is Figure 7 a structure schematic diagram of the section B-B.

[0029] Figure 9 It is Figure 7 an exploded view.

[0030] Figure 10 It is a structure schematic diagram of the actuating piston in specific embodiments of the present application.

[0031] Figure 11 It is a perspective view of the actuating piston in specific embodiments of the present application.

[0032] Figure 12 It is a structure schematic diagram of the pressure maintaining mechanism removing the installation chamber in specific embodiments of the present application.

[0033] Figure 13 It is an assembly structure schematic diagram of the rotor seat and the inner rotor in specific embodiments of the present application.

[0034] Figure 14 FIG. 1 is a schematic view of an inner rotor according to an embodiment of the present application.

[0035] BRIEF DESCRIPTION OF DRAWINGS 1 - electro-hydraulic actuator; 2 - mounting cylinder; 3 - damper; 4 - rotor seat; 41 - first rotor seat communication hole, 42 - second rotor seat communication hole; 5 - inner rotor; 6 - upper chamber; 7 - lower chamber; 8 - actuator rod; 9 - actuator piston; 10 - hydraulic oil chamber; 13 - pressure maintaining mechanism; 14 - mounting chamber; 15 - control valve core; 191 - first check valve core; 192 - second check valve core; 201 - first valve seat; 202 - second valve seat; 211 - first return member; 212 - second return member; 221 - first oil inlet; 222 - second oil inlet; 231 - first oil outlet; 232 - second oil outlet; 24 - mounting groove; 25 - mounting cover; 26 - positioning member; 27 - buffer pad; 28 - cylinder body; 29 - first spring; 30 - second spring; 31 - magnetostrictive column; 21 - first shaft hole; 33 - coil winding; 34 - mounting column; 35 - mounting ring groove; 36 - second shaft hole; 37 - valve plate; 38 - fixed piston; 39 - through hole; 40 - piston rod. DETAILED DESCRIPTION

[0036] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations can be implemented in any

[0037] In view of the above, example implementations of the present disclosure provide a structure of an inner rotor that is capable of Figures 1-14The present disclosure provides a stiffness-adjustable shock absorber 3, comprising a cylinder 28 and a first spring 29, one end of the first spring 29 being fixed to the outside of the cylinder 28; an electro-hydraulic actuator 1, the other end of the first spring 29 being fixed to the outside of the electro-hydraulic actuator 1, the electro-hydraulic actuator 1 comprising a connecting part and an actuating part, the connecting part being arranged at one end of the actuating part; a piston rod 40, which is arranged in the cylinder 28 in an axial sliding manner, and one end of the piston rod 40 extends out of the cylinder 28 and is connected to the connecting part, and the other end of the piston rod 40 is provided with a piston valve plate part and a magnetostrictive part, and a second spring 30 is arranged between the magnetostrictive part and the piston valve plate part, and the second spring 30 abuts against the magnetostrictive part and the piston valve plate part respectively; wherein when the magnetostrictive part generates axial expansion and contraction deformation under the change of the magnetic field, the pre-tightening force of the second spring 30 changes, and when the actuating part moves axially in the electro-hydraulic actuator 1, the connecting part drives the piston rod 40 to move, thereby adjusting the pre-tightening force of the first spring 29.

[0038] For example, the cylinder 28 of the shock absorber 3 is made of high-strength alloy material and has a cylindrical structure with open ends, and an annular boss is arranged on the outer peripheral wall of the cylinder 28 near the end position for positioning the first spring 29. The first spring 29 is selected as a coil spring, one end of which abuts against the annular boss of the cylinder 28, and the other end of which extends axially and is fixed to the outside of the housing of the electro-hydraulic actuator 1. By the axial movement of the actuating piston 9 in the electro-hydraulic actuator 1, the axial pre-compression amount of the first spring 29 is changed, thereby affecting the initial stiffness characteristics of the shock absorber 3, and the magnetostrictive part is combined to realize precise control of the damping force. The overall structure is compact and responds quickly, and is suitable for the multi-working-condition use requirements of the vehicle suspension system.

[0039] Specifically, referring to Figures 1-6 The piston rod 40 can be made of 40Cr alloy and is quenched and tempered to improve strength and toughness, and is assembled in the cylinder 28 in an axial sliding manner. The magnetostrictive part is arranged on the piston rod 40, and the magnetostrictive part comprises a magnetostrictive column 31, a coil winding 33 and a mounting column 34. The magnetostrictive column 31 is made of super-magnetostrictive material, which can be made of Terfenol-D super-magnetostrictive material. The material has a large magnetostrictive coefficient and a fast response speed, and can quickly generate axial expansion and contraction deformation when the magnetic field changes. The coil winding 33 is wound by enameled copper wire with a temperature resistance grade of 155, which has good insulation and heat resistance.

[0040] Further illustrated, the center of the magnetostrictive column 31 is provided with a first shaft hole 21, which is sleeved on the piston rod 40 through transition fit, ensuring no relative sliding; the center of the mounting column 34 is provided with a second shaft hole 36, which is also sleeved on the piston rod 40 through transition fit and abuts against the end face of the magnetostrictive column 31, the abutting faces of the two are positioned by a positioning pin to prevent relative rotation, or the mounting column 34 and the magnetostrictive column 31 can also be fixed by thread connection or clamping and the like; the coil winding 33 is sleeved in the mounting ring groove 35 of the mounting column 34, and is fixed by epoxy resin pouring to avoid displacement of the coil winding 33 caused by vehicle vibration, the lead of the coil winding 33 extends to the outside through the wire hole reserved in the cylinder 28, and a rubber sealing sleeve is arranged in the wire hole to prevent hydraulic oil leakage and dust entry.

[0041] Referring to Figures 1-3 and Figure 6 , for example, the end of the piston rod 40 is fixed with a fixed piston 38 through a threaded structure, and the outer peripheral wall of the fixed piston 38 is gap-fitted with the inner wall of the cylinder 28; a plurality of through holes 39 are uniformly distributed on the fixed piston 38 in the circumferential direction, serving as hydraulic oil flow channels; the valve sheet 37 can be made of 65Mn elastic metal sheet and has good elastic recovery, and is arranged on the side of the fixed piston 38 close to the second spring 30, with the edge of the valve sheet 37 lapping the end face of the fixed piston 38 to completely block all the through holes 39, and keeping the through holes 39 closed under the pre-tightening force of the second spring 30 in normal state; the threaded connection part of the fixed piston 38 and the piston rod 40 is coated with thread glue to prevent thread loosening caused by long-term vibration. The second spring 30 is selected to be a curved spring, with one end abutting against the end face of the magnetostrictive column 31 and the other end abutting against the center position of the valve sheet 37, the compression amount of the second spring 30 is controlled by the deformation of the magnetostrictive column 31, and then the opening pressure of the valve sheet 37 is controlled.

[0042] For example, referring to Figures 7-14 , the shock absorber 3 further comprises an electro-hydraulic actuator 1, including a mounting cylinder 2 with an accommodating cavity, the mounting cylinder 2 is generally cylindrical, and a sealed accommodating cavity is formed in the inside of the mounting cylinder 2. The mounting cylinder 2 is provided with an actuating rod 8 at one axial end, and the mounting cylinder 2 is provided with a connecting hole, the actuating rod 8 extends out of the mounting cylinder 2 through the connecting hole, the actuating rod 8 can be connected by thread connection or flange connection structure, and is used for rigidly connecting with an external moving part, and the function of the actuating rod 8 is to transmit the axial movement of the actuating piston 9 to the piston rod 40, drive the piston rod 40 to axially displace in the cylinder 28, and then change the compression amount of the first spring 29.

[0043] Referring to Figures 7-14The housing contains a rotor seat 4 and an inner rotor 5 that mesh with each other, forming an eccentric internal meshing transmission structure. The inner rotor 5 is designed as a gear-like structure, and the inner wall of the rotor seat 4 is machined with gear grooves that match the tooth profile of the inner rotor 5. The gear grooves and the inner rotor 5 are eccentrically arranged, with the eccentricity preset according to the damping characteristics. The number of teeth on the gear grooves is greater than the number of teeth on the inner rotor 5. When the inner rotor 5 rotates within the rotor seat 4, several sealed oil chambers 10 with varying volumes are formed between the teeth. The inner rotor 5 is positioned and assembled inside the rotor seat 4 through a shaft hole. A drive component, which can be a motor, is located within the gear groove. The motor shaft is connected to the shaft hole of the inner rotor 5, driving the inner rotor 5 to rotate. The two components are coaxially linked and together divide the housing of the mounting cylinder 2 axially into two independent upper chambers 6 and lower chambers 7, providing a channel for the bidirectional flow of oil.

[0044] By mounting the drive unit on the rotor base 4, the drive and transmission structures can be integrated. The drive unit is directly mounted on the bottom of the gear slot in the rotor base 4, and the motor shaft is directly connected to the shaft hole of the inner rotor 5, eliminating the need for additional couplings, drive shafts, and other intermediate transmission components. This design significantly shortens the transmission path, reduces energy loss and signal delay during transmission, and enables the inner rotor 5 to respond quickly to drive commands, achieving precise and real-time adjustment of damping force. The integrated arrangement of the drive unit with the rotor base and inner rotor eliminates the need for separate drive installation space externally or in other locations. This design effectively reduces the overall size and axial length of the electro-hydraulic actuator 1, meeting the vehicle chassis's requirements for miniaturized and lightweight components, while also facilitating integrated assembly with other shock absorber components.

[0045] By changing the volume of the hydraulic oil chamber 10, a negative pressure is created when the chamber expands, drawing hydraulic oil from the upper chamber 6 or lower chamber 7 of the mounting cylinder 2. When the chamber contracts, high pressure is generated, squeezing the hydraulic oil to the other chamber. This allows the flow rate of the hydraulic oil to be dynamically adjusted with the rotation angle of the inner rotor 5, thereby achieving continuous stepless adjustment of the damping force. Furthermore, firstly, the hydraulic oil is controlled by the meshing of gear slots with the inner rotor 5. During the rotation of the inner rotor 5, multiple tooth surfaces are always simultaneously meshing instead of a single tooth contact, evenly distributing the transmitted torque and hydraulic pressure to multiple meshing tooth pairs, significantly reducing stress concentration on individual tooth surfaces. This design greatly improves the load-bearing capacity of the rotor seat 4 and the inner rotor 5, avoiding excessive wear or breakage of local tooth surfaces and extending the service life of components. Secondly, the higher overlap coefficient of the multi-tooth meshing and the smoother switching of tooth surface contact during meshing effectively absorb impact energy during transmission, reducing mechanical vibration and noise generated by gear meshing, and improving the smoothness of the electro-hydraulic actuator 1's operation, making it particularly suitable for high-frequency vibration scenarios such as vehicles or construction machinery. Thirdly, the multi-tooth meshing makes the volume change of the hydraulic oil chamber 10 more uniform, and the intake and discharge rates of hydraulic oil more stable, avoiding the pulsed oil supply phenomenon when single-tooth or few-tooth meshing occurs. This design makes the output of damping force exhibit excellent linear characteristics, meeting the requirements of the shock absorber for precise damping control.

[0046] See Figures 7-14 The actuating piston 9 adopts a modular integrated design and is assembled inside the mounting cylinder 2. For example, to achieve reliable assembly between the rotor seat 4 and the actuating piston 9, the inner wall of the actuating piston 9 is machined with a mounting groove 24. One axial end of the rotor seat 4 extends to form an annular mounting cover 25. The outer diameter of the mounting cover 25 and the inner diameter of the mounting groove 24 can be transition-fitted. After assembly, axial limiting is achieved by snap rings or end face riveting, firmly fixing the rotor seat 4 inside the actuating piston 9. In addition, a circumferential positioning element 26 is embedded between the mating surfaces of the rotor seat 4 and the mounting groove 24. The positioning element 26 can be, for example, a rectangular spline, a positioning pin, or a spring-loaded key. Circumferential positioning is achieved through interference fit, effectively preventing relative rotation between the rotor seat 4 and the actuating piston 9, ensuring transmission accuracy and oil circuit sealing.

[0047] See Figures 7-10A buffer pad 27 is also embedded in the lower cavity 7 of the mounting cylinder 2. The buffer pad 27 can be made of polyurethane or nitrile rubber. One end of the buffer pad 2 is fixed to the bottom of the mounting cylinder 2, and the other end protrudes axially from the bottom end face of the mounting cylinder 2 at a predetermined height. When the actuating rod 8 drives the actuating piston 9 to move to the bottom of the mounting cylinder 2 to its limit stroke, the buffer pad 27 absorbs the impact energy through elastic deformation, realizing flexible contact between the actuating piston 9 and the mounting cylinder 2, avoiding wear, deformation and abnormal noise of components caused by rigid impact, and extending the service life of the product. On the other hand, a wire receiving cavity is formed axially inside the buffer pad 27. The receiving cavity can be designed as a cylindrical or rectangular cavity structure, and the two ends of the cavity are provided with wire inlets and outlets, and elastic sealing sleeves are provided at the inlets and outlets. The wire receiving cavity is used to accommodate the control wires or signal wires required for the operation of the electro-hydraulic actuator 1, so that the wires are arranged in an orderly manner inside the cavity. This design makes the wire layout of the entire electro-hydraulic actuator 1 more regular, avoids interference between the wires and moving parts, and prevents the insulation layer of the wires from being damaged due to vibration and friction, thereby improving the reliability and safety of the shock absorber's electrical system.

[0048] Preferred, see Figures 7-14 The actuating piston 9 integrates a pressure-holding mechanism 13, which is located on the side wall of the actuating piston 9. The hydraulic oil chamber 10 is connected to the upper and lower chambers 7 of the receiving chamber through the pressure-holding mechanism 13. Specifically, the pressure-holding mechanism 13 includes a mounting chamber 14 and a control valve core 15 that can slide along the axial direction of the mounting chamber 14. The control valve core 15 and the inner wall of the mounting chamber 14 are fitted with a clearance seal, dividing the inner cavity of the mounting chamber 14 into two independent hydraulic units, the first unit and the second unit, along the axial direction. The first unit connects the hydraulic oil chamber 10 and the upper chamber 6 of the mounting cylinder 2 through the first rotor seat connecting hole 41, and the second unit connects the hydraulic oil chamber 10 and the lower chamber 7 of the mounting cylinder 2 through the second rotor seat connecting hole 42, realizing a bidirectional conduction path for the hydraulic circuit.

[0049] The pressure-holding mechanism 13 has two symmetrically arranged hydraulic check valves, which are respectively embedded in the first unit and the second unit, and are distributed in a mirror image with the control valve core 15 as the center. The first hydraulic check valve consists of a first valve seat 201, a first check valve core 191, and a first reset member 211; the second hydraulic check valve consists of a second valve seat 202, a second check valve core 192, and a second reset member 212. The reset member can be a spring. The valve seat is fixed in the valve seat hole on the side wall of the mounting chamber 14 by interference fit. The check valve core adopts a shaft structure. One end of the core is elastically connected to the valve seat through the reset member, and the other end is always tightly pressed against the end face of the control valve core 15 under the pre-tightening force of the reset member to form a reliable seal. The first hydraulic check valve connects the first oil inlet 221 and the first oil outlet 231. The first oil inlet 221 is connected to the upper chamber 6 to achieve oil circuit connection. The first oil outlet 231 is connected to the oil passage groove in the actuating piston 9. The oil passage groove is located on the upper part of the liquid oil chamber 10 and is in communication with the liquid oil chamber 10. The second hydraulic check valve connects the second oil inlet 222 and the second oil outlet 232. The second oil inlet 222 is connected to the lower chamber 7 through the second rotor seat connecting hole 42 to achieve oil circuit connection. The second oil outlet 232 is connected to the liquid oil chamber 10 through the first rotor seat connecting hole 41. The on / off state between the inlet and outlet is precisely controlled by the contact or separation state of the check valve core and the control valve core 15.

[0050] The working principle of the pressure holding mechanism 13 is as follows: When the control valve core 15 is not subjected to external hydraulic pressure, the valve cores of the two hydraulically controlled check valves are tightly fitted to the end faces of the control valve core 15 under the pre-tightening force of the reset element, thus isolating the oil inlet and outlet of the hydraulically controlled check valve. At this time, the oil circuits between the first unit and the upper chamber 6 and the hydraulic oil chamber 10, and between the second unit and the lower chamber 7 and the hydraulic oil chamber 10 are all locked, preventing hydraulic oil from flowing between the chambers. The pressure of the hydraulic oil chamber 10 remains stable, preventing unexpected leakage of the hydraulic oil chamber 10 and ensuring the stability of the damping force output. When the inner rotor 5 rotates, the eccentric meshing structure between the inner rotor 5 and the rotor seat causes a change in the volume of the oil chamber 10, which in turn creates a pressure difference between the oil chamber 10 and the upper chamber 6 or the lower chamber 7. The control valve core 15 is displaced axially along the mounting chamber 14. One end face of the control valve core 15 pushes the corresponding check valve core, causing it to overcome the preload of the reset element and move towards the valve seat, releasing the sealing contact between the check valve core and the control valve core 15 on that side, and making the oil inlet and outlet of the hydraulic check valve on that side connected.

[0051] 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 vibration damper with adjustable stiffness, characterized in that, The vibration damper includes: The cylinder and the first spring, with one end of the first spring fixed to the outside of the cylinder; An electro-hydraulic actuator, wherein the other end of the first spring is fixed to the outside of the electro-hydraulic actuator, the electro-hydraulic actuator includes a connecting part and an actuating part, the connecting part being located at one end of the actuating part; The piston rod is slidably disposed in the cylinder along the axis, with one end extending out of the cylinder and connected to the connecting part, and the other end provided with a piston valve plate and a magnetostrictive part. A second spring is provided between the magnetostrictive part and the piston valve plate, which respectively abuts against the magnetostrictive part and the piston valve plate. When the magnetostrictive part undergoes axial expansion and contraction due to changes in the magnetic field, the preload of the second spring changes. When the actuator moves axially within the electro-hydraulic actuator, the connecting part drives the piston rod to move, thereby adjusting the preload of the first spring.

2. The vibration damper according to claim 1, characterized in that, The magnetostrictive part includes a magnetostrictive column made of a super magnetostrictive material, which has a first shaft hole that mates with the piston rod to assemble the magnetostrictive column onto the piston rod.

3. The vibration damper according to claim 2, characterized in that, The magnetostrictive part further includes a coil winding, which is located on one side of the magnetostrictive column and is used to generate a variable magnetic field to drive the magnetostrictive column to undergo axial expansion and contraction deformation.

4. The vibration damper according to claim 3, characterized in that, The magnetostrictive part further includes a mounting post, which is connected to the mounting post. The mounting post has a mounting ring groove and the coil winding is wrapped around the mounting ring groove. The mounting post also has a second shaft hole, which cooperates with the piston rod to assemble the mounting post onto the piston rod.

5. The vibration damper according to claim 1, characterized in that, The piston valve plate includes a valve plate and a fixed piston. The fixed piston is fixed to the end of the piston rod and has a through hole. The valve plate is located on the side of the fixed piston near the second spring and blocks the through hole. The valve plate opens under the action of oil pressure, overcoming the preload of the second spring.

6. The vibration damper according to claim 1, characterized in that, The electro-hydraulic actuator includes: The mounting cylinder has a receiving cavity, one end of which is provided with an end cap, and the other end is open for the connecting part to extend out. The actuating piston is slidably positioned within the receiving cavity, dividing the interior of the receiving cavity into an upper cavity and a lower cavity; The connecting part is an actuating rod. One end of the connecting part is fixedly connected to the actuating piston, and the other end extends out of the mounting cylinder and is connected to the piston rod.

7. The vibration damper according to claim 6, characterized in that, The actuating piston includes: The first oil port connects the upper cavity and the second oil port connects the lower cavity; An internally meshing inner rotor and a rotor seat, wherein the inner rotor is eccentrically mounted on the rotor seat, and a driving component is provided inside the rotor seat to drive the inner rotor to rotate; When the inner rotor rotates, a fluid oil chamber with changing volume is formed between the inner rotor and the rotor seat. The fluid oil chamber is connected to the upper chamber and the lower chamber through the first oil port and the second oil port.

8. The vibration damper according to claim 7, characterized in that, The actuating piston also includes a pressure-holding mechanism, and the oil chamber is connected to the first oil port and the second oil port through the pressure-holding mechanism.

9. The vibration damper according to claim 7, characterized in that, The actuating piston includes a mounting groove and a positioning element. The rotor seat is installed in the mounting groove, and the positioning element is engaged between the rotor seat and the mounting groove to prevent the rotor seat and the mounting groove from rotating relative to each other.

10. The vibration damper according to claim 9, characterized in that, A buffer pad is provided on the side of the actuating piston that contacts the lower chamber. The buffer pad protrudes from the actuating piston and is used to provide cushioning.

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