Double-order broadband magneto-rheological damper
By integrating micro-vibration and magnetorheological damping mechanisms, the two-stage wideband magnetorheological damper solves the problem of insufficient damping force coverage in wideband vibration environments, realizes dynamic switching of damping force in a wide frequency range, and ensures stable operation of high-precision equipment.
Patent Information
- Application Number
- CN202511850514.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-01-30
AI Technical Summary
Existing magnetorheological vibration dampers have insufficient damping force coverage in wide-frequency vibration environments, and their vibration damping performance degrades at high-frequency vibrations. Furthermore, active vibration isolation technology suffers from control signal time lag, making it difficult to meet the stable operation requirements of high-precision equipment.
A two-stage broadband magnetorheological damper is designed, integrating a micro-vibration damping mechanism and a magnetorheological damping mechanism. By matching the force threshold and controlling the magnetic field, the damping force can be dynamically switched over a wide frequency range. During micro-vibration, the micro-vibration damping mechanism dominates, while during high-vibration, the magnetorheological material dominates, providing adaptive damping.
It achieves effective vibration reduction from high-frequency micro-amplitude to low-frequency large-amplitude, breaking through the bottleneck of micro-vibration isolation in low-frequency vibration isolation of traditional products, ensuring stable operation of equipment under all working conditions, and reducing weight and complexity.
Smart Images
Figure CN121429752A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of shock absorbers, in particular to a double-stage wide-frequency magneto-rheological shock absorber. BACKGROUND
[0002] In the fields of aerospace, precision manufacturing, and other special occasions such as control moment gyro systems, the stable operation of high-precision equipment requires strict vibration control of the working environment. Such equipment is often in a complex vibration environment, and the mechanical load they bear varies significantly during different working stages, with vibration frequencies covering a wide frequency range from zero hertz to several thousand hertz. This poses a major challenge to the performance adaptability of vibration isolation devices.
[0003] From the perspective of vibration isolation requirements, the equipment needs a large damper to effectively suppress vibration transmission during the low-frequency large-amplitude working stage. When entering the high-frequency micro-amplitude stage, the vibration response is exacerbated by excessive damping, and the vibration isolator is required to output minimal damping force. This dynamic switching requirement of damping characteristics in a wide frequency range is a core difficulty in the design of vibration isolation devices.
[0004] In recent years, magneto-rheological technology has been widely regarded as an important direction for solving wide-frequency vibration isolation problems due to its adjustable damping characteristics. However, current conventional magneto-rheological fluids generally exhibit high-frequency hardening, and their vibration reduction performance significantly deteriorates under high-frequency micro-vibration conditions, making it difficult to meet the vibration isolation requirements of precision equipment. At the same time, the mainstream magneto-rheological semi-active vibration isolation technology relies on a closed-loop control system, and when facing high-frequency vibrations, the transmission and processing of control signals will inevitably cause time delay problems, resulting in a lag in the response of the vibration isolation system and further weakening the high-frequency vibration isolation effect, directly threatening the normal operation of precision equipment.
[0005] Therefore, there is an urgent need to develop a double-stage wide-frequency magneto-rheological shock absorber that can effectively address the problems of insufficient damping force coverage, complex structure, and heavy weight of the shock absorber under wide-frequency vibration. SUMMARY
[0006] Therefore, there is an urgent need to develop a double-stage wide-frequency magneto-rheological shock absorber that can effectively address the problems of insufficient damping force coverage, complex structure, and heavy weight of the shock absorber under wide-frequency vibration.
[0007] The present invention discloses a two-stage broadband magnetorheological vibration damper, comprising a damping cylinder and a piston assembly disposed within the damping cylinder and having a clearance fit with the damping cylinder. The damping cylinder contains a magnetorheological material for damping large-amplitude vibrations between the damping cylinder and the piston assembly. The piston assembly includes a piston rod and a piston head that slides with the piston rod, and a micro-vibration damping mechanism for attenuating minute vibrations is provided between the piston rod and the piston head. The maximum damping force generated by the micro-vibration damping mechanism is not greater than the minimum damping force generated by the magnetorheological material.
[0008] Furthermore, the piston head is provided with at least one magnetic source that provides a magnetic field for the magnetorheological material to form a magnetorheological effect.
[0009] Furthermore, the micro-vibration damping mechanism includes spring I and spring II sleeved on the piston rod, and spring I and spring II are respectively disposed on both sides of the piston head. The piston rod end is provided with a spring baffle that abuts against spring I, and a shoulder that abuts against spring II is formed in the middle. Spring I and spring II are applied with preload forces in opposite directions to provide centering and resetting effect on the piston head.
[0010] Furthermore, the springs I and II have the same spring characteristics, and their maximum elastic force under compression or tension is not greater than the minimum damping force generated by the magnetorheological material between the piston assembly and the damping cylinder.
[0011] Furthermore, it also includes a support spring fitted onto the damping cylinder to form a support.
[0012] Furthermore, one end of the damping cylinder is provided with a cylinder cover, the piston rod passes through the cylinder cover and is provided with a baffle lug at the end, the other end of the damping cylinder extends outward to form a baffle, and the support spring is disposed between the baffle lug and the baffle and is subjected to a preload to form support.
[0013] Furthermore, the damping cylinder body is made of a magnetically conductive material.
[0014] Furthermore, the magnetorheological material is a magnetorheological fluid, which fills the cavity formed between the damping cylinder and the piston assembly.
[0015] Furthermore, the magnetorheological material is a magnetorheological fluid composite material, which adheres to the gap between the inner wall of the damping cylinder and the outer surface of the piston assembly.
[0016] The beneficial effects of the present application: the double-stage broadband magneto-rheological damper of the present application, by connecting the micro-vibration damping mechanism for small vibration and the magneto-rheological damping mechanism for large vibration in series, and reasonably matching the force threshold values of the two, so that the micro-vibration damping mechanism mainly works when the input amplitude is small, providing very small damping to isolate or attenuate small vibration; when the amplitude increases and the force exceeds the minimum damping force threshold of the magneto-rheological damper, the magneto-rheological damping starts to dominate, providing strong adjustable damping, thereby effectively covering the broadband vibration from high-frequency micro-amplitude to low-frequency large amplitude; at the same time, the introduction of the micro-vibration damping mechanism breaks through the bottleneck that the minimum damping force of the traditional product is difficult to meet the demand of micro-vibration in the order of magnitude when considering low-frequency vibration isolation, effectively ensuring the stable operation of the equipment under all working conditions. BRIEF DESCRIPTION OF DRAWINGS
[0017] The present application will be further described below in conjunction with the drawings and examples:
[0018] Figure 1 The present application is a cross-sectional structure schematic diagram;
[0019] Figure 2 The present application is a cross-sectional structure schematic diagram of the magneto-rheological fluid composite material.
[0020] Explanation of reference signs: 1, supporting spring; 2, damping cylinder; 201, baffle; 202, guide cover; 203, cylinder cover; 3, piston assembly; 301, piston rod; 302, shaft shoulder; 303, piston head; 304, magnetic source; 305, spring I; 306, spring II; 307, spring baffle; 4, baffle lifting lug; 5, magneto-rheological fluid composite material. DETAILED DESCRIPTION
[0021] It should be noted that in the description of the present application, the terms "upper", "lower", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.
[0022] As shown in the figure, the double-stage broadband magneto-rheological damper of the present embodiment comprises a damping cylinder 2 for sealing and containing magneto-rheological material and a piston assembly 3 installed inside the damping cylinder 2 and in a specific gap fit with the damping cylinder 2; the gap or cavity between the damping cylinder 2 and the piston assembly 3 is filled with magneto-rheological material which can change rheological properties under the action of magnetic field, thereby forming adjustable damping effect on large amplitude vibration; the piston assembly 3 is further composed of a piston rod 301 and a piston head 303 which are in sliding fit and are provided with a micro-vibration damping mechanism specially used for attenuating high frequency and micro-vibration, the maximum elastic force generated by the micro-vibration damping mechanism always does not exceed the minimum damping force generated by the magneto-rheological material in the minimum excitation state, thereby ensuring that the damping mechanisms under different amplitudes do not interfere with each other and realizing smooth damping in a wide frequency range; the damping force generated by the micro-vibration damping mechanism is extremely small, mainly being the inevitable micro-friction force between the relatively sliding piston rod and piston head.
[0023] In the present embodiment, at least one magnetic source 304 is arranged on the piston head 303, which can be a permanent magnet or an electromagnetic coil; when the electromagnetic coil provides a magnetic field as the magnetic source 304, the strength of the magneto-rheological effect of the magneto-rheological material can be accurately controlled by changing the size of the current, thereby realizing real-time regulation of the damping force size, so that the damper can flexibly adjust the damping characteristics according to different vibration conditions to adapt to diversified damping requirements; when the permanent magnet provides a magnetic field as the magnetic source 304, the damper can be used as a passive damper, although it cannot adjust the damping force generated thereby, but the performance of the passive damper is more stable and reliable.
[0024] In the present embodiment, the micro-vibration damping mechanism comprises a spring I 305 and a spring II 306 which are sleeved on the piston rod 301 and are arranged on both sides of the piston head 303 respectively; the piston rod 301 is installed with the piston head 303, one end of which is fixedly installed with a spring baffle 307, the spring baffle 307 is installed on the end of the piston rod 301 through a pin, used for abutting against the spring I 305 and capable of effectively preventing the spring I 305 from axially moving during work, and the middle part of the piston rod 301 is designed with a shaft shoulder 302 structure for abutting against the spring II 306; the spring I 305 and the spring II 306 are both applied with a certain pre-tightening force during installation, and the directions of the two forces are opposite, jointly acting on the piston head 303, so that it remains in the centered position when it is static and provides a reset action when it is subjected to a micro-displacement, and the elastic deformation and extremely low damping force of the spring can realize efficient damping of micro-vibration, avoiding transmission of micro-vibration to the equipment or structure body.
[0025] In this embodiment, the spring I 305 and the spring II 306 have the same spring characteristic parameters, such as stiffness, wire diameter and number of turns, etc., so that the two springs can produce symmetrical elastic deformation when stressed, ensuring that the piston head 303 is in force balance to ensure symmetrical response; at the same time, when the spring reaches the maximum compression or stretching state, the maximum elastic force generated is still not greater than the minimum damping force that can be formed between the piston assembly 3 and the damping cylinder 2 by the magnetorheological material in the zero magnetic field state, which ensures that in the range of micro-vibration, the vibration reduction is mainly borne by the micro-vibration damping mechanism, without triggering the main damping effect of the magnetorheological material, and at the same time, the compressible stroke should be designed according to the actual high-frequency micro-vibration working condition, and the stroke should match the micro-vibration amplitude.
[0026] In this embodiment, a supporting spring 1 is further included, which is sleeved outside the damping cylinder 2, and mainly functions to provide support for the whole damper, thereby ensuring the overall stability and damping effect of the system at the installation position.
[0027] In this embodiment, one end of the damping cylinder 2 is provided with a cylinder cover 203, the piston rod 301 passes through the center hole of the cylinder cover 203, and a baffle lifting lug 4 is installed at the exposed end; the other end of the damping cylinder 2 extends outward to form a baffle 201, the supporting spring 1 is installed between the baffle lifting lug 4 and the baffle 201, and a certain pre-tightening force is applied during assembly, so as to keep the structure tensioned and supported under normal working conditions.
[0028] In this embodiment, the damping cylinder 2 is made of a magnetic conductive material, such as low-carbon steel or other soft magnetic alloy, etc., and the damping cylinder 2 is made of a magnetic conductive material to cooperate with the magnetic field generated by the magnetic source 304 on the piston head 303 to form a complete magnetic circuit; when the magnetic source 304 on the piston head 303 works, the magnetic field will start from the magnetic source 304, pass through the piston head 303, the magnetorheological material, the damping cylinder 2, and then return to the magnetic source 304, forming a closed magnetic circuit; the magnetic conductive material has good magnetic conductive performance, which can effectively reduce the magnetic resistance in the magnetic circuit, so that the magnetic field can pass through the magnetorheological material more efficiently, ensuring that the magnetorheological material can be fully affected by the magnetic field, thereby significantly improving the magnetorheological effect and response speed.
[0029] In this embodiment, the magnetorheological material is a magnetorheological fluid, which is filled in the cavity formed between the damping cylinder 2 and the piston assembly 3, i.e., the magnetorheological fluid fills the damping cylinder 2, which is suitable for scenes with a large range of damping force regulation and requires stable damping effect throughout the working stroke, and such working conditions have certain sealing requirements for the device; when the damping cylinder 2 is filled with magnetorheological fluid, the magnetorheological fluid will flow through the gap between the piston head 303 and the damping cylinder 2 during the reciprocating motion of the piston head 303, and the magnetorheological effect can be adjusted to realize accurate regulation of the damping force throughout the movement stroke.
[0030] In this embodiment, the magneto-rheological material is a magneto-rheological fluid composite 5 attached to the gap between the inner wall of the damping cylinder 2 and the outer surface of the piston assembly 3, that is, the magneto-rheological material is only attached to the outer circumferential surface of the piston head 303, forming a layer of uniform magneto-rheological material. The magneto-rheological material can use the magneto-rheological fluid composite 5 in the patent CN114141465A. The magneto-rheological fluid composite 5 can correspond to the shear working mode and the extrusion working mode, effectively broaden the vibration isolation frequency band range of the material, solve the high-frequency hardening phenomenon, and the filling mode is suitable for the scene of high requirements for lightweight, miniaturization and stability of the shock absorber, and mainly for controlling the vibration in a specific frequency range. At the same time, the magneto-rheological fluid composite 5 is attached to the outer circumferential surface of the piston head 303, which can greatly reduce the amount of magneto-rheological material, and has lower requirements for the sealing of the device, reduces the overall weight and manufacturing cost of the shock absorber; and when the piston head 303 moves, the magneto-rheological fluid composite 5 attached to the surface of the piston head 303 can still produce a magneto-rheological effect under the action of a magnetic field, forming an effective damping force to meet the shock absorbing requirements under specific working conditions; the use of the magneto-rheological fluid composite 5 avoids the friction aggravation phenomenon of the additional magneto-rheological material existing in the sliding fit gap between the piston head 303 and the piston rod 301, and can improve the micro-vibration damping performance.
[0031] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the present application, and all should be covered in the scope of the claims of the present application.
Claims
1. A dual-stage broadband magnetorheological damper, characterized in that: The damping cylinder (2) and the piston assembly (3) arranged in the damping cylinder (2) and in clearance fit with the damping cylinder (2), the piston assembly (3) comprising a piston rod (301) and a piston head (303) in sliding fit with the piston rod (301), the damping cylinder (2) being provided with a magneto-rheological material between the damping cylinder (2) and the piston head (303) for damping large amplitude vibration, a micro-vibration damping mechanism being arranged between the piston rod (301) and the piston head (303) for damping micro-vibration, wherein the damping force generated by the micro-vibration damping mechanism and the damping force generated by the magneto-rheological material are in engagement.
2. The dual-stage broadband magneto-rheological damper according to claim 1, wherein: The piston head (303) is provided with at least one magnetic source (304) for providing a magnetic field for the magneto-rheological material to generate magneto-rheological effect.
3. The dual-stage broadband magneto-rheological damper according to claim 1, wherein: The micro-vibration damping mechanism comprises a spring I (305) and a spring II (306) sleeved on the piston rod (301), and the spring I (305) and the spring II (306) are arranged on both sides of the piston head (303), respectively, the end of the piston rod (301) is provided with a spring baffle (307) abutting against the spring I (305), and the middle part of the piston rod (301) is formed with a shaft shoulder (302) abutting against the spring II (306), the spring I (305) and the spring II (306) are provided with pre-tightening force in opposite directions and providing centering and resetting action to the piston head (303).
4. The dual-stage broadband magneto-rheological damper according to claim 3, characterized in that: The spring characteristics of the spring I (305) and the spring II (306) are consistent, and the maximum elastic force of the spring I (305) and the spring II (306) in compression or stretching state is not greater than the minimum damping force generated by the magneto-rheological material between the piston assembly (3) and the damping cylinder (2).
5. The dual-stage wideband magnetorheological damper according to claim 1, wherein: A supporting spring (1) is further sleeved on the damping cylinder (2) for forming support.
6. The dual-stage wideband magnetorheological damper according to claim 5, wherein: One end of the damping cylinder (2) is provided with a cylinder cover (203), the piston rod (301) passes through the cylinder cover (203), and the end is provided with a baffle lifting lug (4), the other end of the damping cylinder (2) extends outward to form a baffle (201), the supporting spring (1) is arranged between the baffle lifting lug (4) and the baffle (201) and is provided with pre-tightening force for forming support.
7. The dual-stage wideband magnetorheological damper according to claim 6, wherein: The inside of the cylinder cover (203) is further provided with a guide cover (202) for restricting the movement track of the piston rod (301).
8. The dual-stage wideband magnetorheological damper according to claim 6, wherein: The damping cylinder (2) is a magnetic conductive material.
9. The dual-stage wideband magnetorheological damper according to claim 1, wherein: The magneto-rheological material is a magneto-rheological fluid filled in the cavity formed between the damping cylinder (2) and the piston assembly (3).
10. The dual-stage wideband magnetorheological damper according to claim 1, wherein: The magneto-rheological material is a magneto-rheological fluid composite material (5) attached to the gap between the inner wall of the damping cylinder (2) and the outer surface of the piston assembly (3).