A magnetically permeable magnetorheological damper suitable for vibration and shock mitigation

Abstract

The application discloses a magnetism-inducing magnetorheological damper suitable for damping and buffering, and belongs to the technical field of intelligent damping control. The damper adopts a double-out-rod hybrid structure, and the core lies in that two coils with different sizes are arranged in the piston head, and a double-stage magnetic circuit is constructed by cooperating with a magnetism-inducing ring and a magnetic isolation ring. The piston head adopts a split type design, and the installation of the coil and the leading of the wire are facilitated. The application realizes double-mode operation through a control strategy. In a vibration working condition, only the small coil is electrified, fine small damping adjustment is provided by using a partial working gap, and comfort is ensured. In an impact working condition, the double coils are electrified at the same time, all working gaps are activated, and great damping force is provided to dissipate impact energy. The application also adopts a double sealing structure of O-shaped rings and Y-shaped rings, and impact resistance is improved. The application has the advantages of compact structure, high magnetic field utilization rate, effective consideration of double requirements of damping and buffering of special vehicle seats, fast response, high reliability and easy maintenance.

Description

Technical Field

[0001] This invention belongs to the field of magnetorheological damper technology, specifically relating to a magnetorheological damper suitable for vibration reduction and buffering. Background Technology

[0002] Magnetorheological dampers, as a typical intelligent material actuator, are widely used in vehicle suspension, vibration isolation of precision instruments, and special protection fields due to their advantages such as low power consumption, fast response, continuously adjustable damping force, and ease of semi-active control. Especially in the design of passenger seats for special vehicles (such as armored vehicles and mine-resistant vehicles), the seat suspension system must simultaneously cope with two distinctly different extreme conditions: one is the continuous, high-frequency, low-amplitude random vibration generated when the vehicle travels on complex road surfaces; the other is the transient, high-intensity, large-displacement impact load generated when encountering landmine explosions or IED attacks.

[0003] However, existing magnetorheological damper technology has revealed serious structural defects and technical bottlenecks when faced with this "dual operating condition" requirement.

[0004] First, the single-function design makes it difficult to simultaneously meet the conflicting demands of "precise vibration reduction" and "powerful cushioning." Most mainstream products on the market currently employ the traditional piston structure with a single coil and single magnetic circuit. This structure often requires a trade-off between "low-speed, low-damping" and "high-speed, high-damping." Under normal driving conditions, to ensure ride comfort, the damper needs extremely high sensitivity to finely adjust for even minor vibrations. If the damping force is too large, road bumps will be directly transmitted to the occupants. Under impact conditions, the system requires the damper to build up a huge damping force in a very short time (milliseconds) to quickly dissipate the enormous impact energy. Traditional single-coil structures, due to their fixed magnetic circuit and limited effective working area, often cannot simultaneously meet these two contradictory performance requirements. Designing high damping for cushioning results in an excessively strong "push-back" feeling during daily driving, or even prevents movement; designing low damping for vibration reduction renders it ineffective during impacts, failing to protect occupants.

[0005] Secondly, the magnetic field utilization rate is low, and the effective working gap is limited. Traditional magnetorheological dampers often have relatively simple magnetic circuit designs, with an unreasonable distribution of magnetic field lines within the damping channel, resulting in significant magnetic leakage. Some magnetic circuit designs lead to poor angles between the magnetic field lines and the fluid flow direction, failing to fully utilize the shear effect of the magnetorheological fluid. This results in a smaller controllable damping force under the same current input, or requires more electrical energy to achieve the desired damping effect. Furthermore, the number of effective working gaps in traditional structures is usually fixed and limited, restricting the adjustment range of the damping force.

[0006] Secondly, the assembly process is poor, and the reliability of the coil leads is low. In moving-coil magnetorheological dampers, the excitation coil typically needs to reciprocate at high speed within the cylinder along with the piston. Existing piston head designs are mostly one-piece structures, requiring the coil to be embedded through complex press-fitting processes or wound in confined spaces. This not only increases manufacturing costs but also makes heat dissipation difficult. More importantly, the coil leads are highly susceptible to stretching and friction during the piston's reciprocating motion, leading to insulation damage, short circuits, or open circuits. This is one of the main causes of failure in existing dampers.

[0007] Finally, the sealing structure lacks reliability under strong impacts. Special vehicles face extremely harsh impact environments with extremely high instantaneous acceleration. Traditional single-seal methods (such as using only O-rings) are prone to seal rollover, extrusion, or permanent deformation under strong impact loads, leading to leakage of the high-pressure magnetorheological fluid. Once a leak occurs, not only will the damper fail, but the leaked oil may also contaminate the vehicle's interior environment and even pose safety hazards.

[0008] In summary, existing technologies have significant shortcomings in terms of adaptability to multiple operating conditions, magnetic circuit efficiency, manufacturing processes, and reliability in extreme environments. Therefore, there is an urgent need to develop a novel magnetorheological damper to address these technical problems. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a magnetorheological damper suitable for vibration reduction and buffering, which addresses the shortcomings of the prior art. This invention solves the technical problems of existing magnetorheological dampers in special vehicle seats, such as difficulty in simultaneously achieving both vibration reduction and buffering, insufficient magnetic field utilization, inconvenience in coil assembly and wire lead-out, and poor sealing reliability under impact conditions.

[0010] The present invention adopts the following technical solution: A magnetorheological damper suitable for vibration reduction and buffering includes an upper end cover and a lower end cover at both ends of a cylinder. A first piston rod and a second piston rod pass through the upper and lower end covers, respectively, and are connected to a first piston head assembly housed inside the cylinder. The second piston head assembly is clearance-fitted with the first piston head assembly, and a third piston head assembly is clearance-fitted with the first piston head assembly, together forming a split piston head. A first coil is installed between the third piston head assembly and the second piston head assembly, and a second coil is installed between the second piston head assembly and the first piston head assembly. The wires of the first and second coils are connected to the interior of the second piston rod through a wire channel inside the piston and exit through a wire outlet. The first magnet... The first piston head component is fitted with a clearance ring, the second magnetic ring is fitted with a clearance ring, the third magnetic ring is fitted with a clearance ring, the first magnetic isolation ring is disposed between the first magnetic ring and the second magnetic ring, and the second magnetic isolation ring is disposed between the third magnetic ring and the second magnetic ring. A first working clearance, a second working clearance, and a third working clearance are formed between the piston head and the inner wall of the cylinder. The upper end cover is sealed to the first piston rod by an upper dynamic sealing O-ring and an upper dynamic sealing Y-ring, the lower end cover is sealed to the second piston rod by a lower dynamic sealing O-ring and a lower dynamic sealing Y-ring, the upper end cover is sealed to the cylinder by an upper static sealing O-ring, and the lower end cover is sealed to the cylinder by a lower static sealing O-ring.

[0011] Preferably, the upper end cover is fitted with the cylinder barrel with a clearance and sealed by an upper static O-ring, and the lower end cover is fitted with the cylinder barrel with a clearance and sealed by a lower static O-ring.

[0012] Preferably, the upper end cover is fixedly connected to the cylinder by bolts, and the lower end cover, connecting pipe and cylinder are fixedly connected by bolts.

[0013] Preferably, the first piston rod is threadedly connected to the first piston head component, and the second piston rod is threadedly connected to the first piston head component.

[0014] Preferably, the upper limit ring is threadedly connected to the first piston head component, and the lower limit ring is threadedly connected to the first piston head component.

[0015] Preferably, the first magnetic isolation ring is installed between the first magnetic attraction ring and the second magnetic attraction ring, and is in clearance fit with the first magnetic attraction ring and the second magnetic attraction ring through a groove; the second magnetic isolation ring is installed between the third magnetic attraction ring and the second magnetic attraction ring, and is in clearance fit with the third magnetic attraction ring and the second magnetic attraction ring through a groove.

[0016] Preferably, the first coil and the second coil are connected to the inside of the second piston rod through a wire channel inside the piston and are led out from the wire outlet.

[0017] Preferably, under vibration conditions, only the first coil is energized, and the first working gap and the second working gap serve as effective damping gaps; under impact conditions, the first coil and the second coil are energized simultaneously, and the first working gap, the second working gap, and the third working gap serve as effective damping gaps.

[0018] Preferably, the first magnetic ring, the second magnetic ring, the third magnetic ring and the cylinder are made of high magnetic permeability material, while the upper limit ring, the first piston head component, the second piston head component, the third piston head component, the first magnetic isolation ring and the second magnetic isolation ring are made of non-magnetic permeability material.

[0019] Preferably, the bottom threaded interface is used to connect to the vehicle floor, and the top threaded interface is used to connect to the seat floor.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects: A magnetorheological damper suitable for vibration reduction and buffering utilizes a dual-outlet rod structure to ensure smooth damper movement and symmetrical force distribution, avoiding uneven wear on one side of the piston rod. A split piston head provides space for coil installation and wire routing, solving the assembly difficulties of traditional integral pistons. Dual coils, combined with three sets of magnetizing and insulating rings, form a graded magnetic circuit, activating different numbers of damping gaps under different operating conditions to achieve graded control of damping magnitude. Multiple sealing structures provide both dynamic and static seals, covering the piston rod sliding parts and the end cap joint, forming a fully enclosed magnetorheological fluid cavity. Under normal vibration conditions, the system only needs to activate a small coil, with the magnetic field acting on a portion of the working gap, providing moderate damping force to absorb high-frequency, low-amplitude vibrations, ensuring ride comfort and operational stability. Under sudden impact conditions, both coils are energized simultaneously, extending the magnetic field to the entire working gap, rapidly outputting a large damping force to dissipate impact energy, greatly improving safety. Furthermore, the split piston head structure not only optimizes the distribution of the internal magnetic circuit and improves the magnetic field utilization rate, but also provides physical space for coil installation and wire lead-out, solving the technical problems of difficult coil assembly and easy wire breakage in traditional integrated piston head designs. The integration of multiple sealing structures ensures that the damper maintains good sealing performance under strong impact loads, preventing magnetorheological fluid leakage and significantly extending the service life and reliability of the equipment.

[0021] Furthermore, the clearance fit facilitates the assembly and positioning of the end cap and cylinder, reduces the precision requirements for machining and assembly, improves production efficiency, and provides reasonable installation space for the seals. The static sealing O-ring, placed in the clearance, undergoes elastic deformation under assembly pressure, filling the tiny gaps and forming a reliable static sealing barrier to prevent magnetorheological fluid leakage from the mating surface between the end cap and cylinder. This design balances ease of assembly with sealing reliability, avoiding assembly jamming due to excessive tightness and sealing failure due to excessive looseness. It maintains the integrity of the mating surface seal even under strong impact and vibration conditions, reducing the risk of oil leakage, improving the long-term stability of the damper, adapting to harsh operating conditions in special vehicles, reducing maintenance costs, and increasing product durability.

[0022] Furthermore, the bolted connection is a detachable rigid connection, facilitating damper assembly, maintenance, parts replacement, and magnetorheological fluid injection. Compared to welding, bonding, and other fixing methods, it offers lower maintenance costs and easier repairs. The bolted connection provides uniform preload, ensuring a tight fit between the end cap and cylinder, and between the lower end cap and connecting pipe, enhancing overall structural rigidity and preventing loosening or displacement under impact loads, thus guaranteeing structural stability. Simultaneously, the sealing compression can be controlled by adjusting the bolt preload, optimizing the sealing effect and balancing structural strength, assembly convenience, and sealing reliability. This meets the requirements of frequent disassembly and high-intensity use of special vehicle seat dampers. Furthermore, the threaded connection is a rigid, detachable connection with high strength and good coaxiality, ensuring synchronous movement of the piston rod and piston head, avoiding motion lag and radial wobble, and improving the damper's response speed and control accuracy. The threaded connection is easy to assemble and disassemble, allowing for individual replacement of the piston rod or piston head, reducing maintenance costs. The connection is tight and gapless, and will not loosen or fall off under high-frequency vibration and strong impact conditions, ensuring stable power transmission, improving structural reliability and service life, and adapting to the complex load environment of special vehicles.

[0023] Furthermore, the limiting ring is used to limit the piston head stroke, preventing excessive piston movement from impacting the end cover and avoiding structural damage and seal failure; the threaded connection facilitates adjustment of the axial position of the limiting ring, adapting to different stroke requirements and offering strong versatility; the limiting ring can absorb some impact energy, reducing the impact load on the end cover and protecting the internal coil and sealing structure; at the same time, it plays an axial positioning role for the piston head components, magnetic ring, and magnetic isolation ring, ensuring the stability of the magnetic circuit structure, uniform magnetic field distribution, improving damping output consistency and control accuracy, and extending the service life of the damper.

[0024] Furthermore, the grooved structure enables precise positioning of the magnetic isolation ring, preventing axial and circumferential movement and ensuring the stability of the magnetic circuit structure; the clearance fit facilitates assembly and avoids stress concentration caused by interference fit; the magnetic isolation ring can block magnetic leakage and guide magnetic field lines to pass perpendicularly through the damping gap, improving magnetic field utilization; the grooved fit enhances the overall structural integrity, maintains the stability of the magnetic circuit geometry under impact vibration, ensures stable and reliable damping output, improves the dual-condition adjustment accuracy, and solves the problems of disordered magnetic field line distribution and low magnetic field utilization in traditional dampers.

[0025] Furthermore, the built-in wire channel prevents the wires from being exposed, preventing wear and tear and breakage due to compression, thus improving the service life and electrical reliability of the wires; the wires are led out from inside the piston rod, without occupying external space, resulting in a compact and aesthetically pleasing structure that avoids interference; the wiring is neat and tidy, facilitating connection and maintenance, solving the defects of messy, easily damaged, and inconveniently assembled wires in traditional dampers, ensuring stable power supply from the dual coils, and improving the reliability of the damper's electrical system.

[0026] Furthermore, in vibration conditions, only the small coil is energized, activating two gaps to achieve fine adjustment of small damping; in impact conditions, both coils are energized, activating three gaps to output large damping. The damping magnitude can be adaptively switched, balancing driving comfort and impact safety; it responds rapidly to meet the needs of transient high load buffering; the graded magnetic circuit design reduces energy consumption, achieving semi-active precise control, solving the problem that traditional dampers cannot simultaneously achieve vibration reduction and buffering, and is suitable for use in all working conditions of special vehicles.

[0027] Furthermore, the magnetic ring and cylinder are made of high-permeability materials to reduce magnetic resistance, concentrate magnetic field lines, and increase magnetic field strength; the piston head and magnetic isolation ring are made of non-magnetic materials to block magnetic leakage and guide magnetic field lines to pass perpendicularly through the damping gap, thereby improving magnetic field utilization. Material optimization improves damping output capacity and adjustment range, ensures stable performance under dual operating conditions, and solves the defects of unreasonable magnetic circuit design and low magnetic field utilization in traditional dampers.

[0028] Furthermore, the upper and lower threaded interfaces are defined to connect the seat base plate and the vehicle floor plate respectively, ensuring precise installation and positioning, secure connection, and convenient assembly and disassembly; the interfaces are standardized to adapt to various special vehicle seat structures, providing strong versatility; ensuring reliable installation of the damper, effectively transmitting vibration and impact loads, improving vibration damping and buffering effects, and enhancing assembly efficiency and versatility.

[0029] In summary, this invention achieves adjustable damping under dual operating conditions, high magnetic field utilization, convenient assembly, reliable sealing, stable structure, fast response, and strong versatility through dual coils, graded magnetic circuits, split pistons, double sealing, and reasonable material selection. It can simultaneously meet the requirements of vibration reduction comfort and impact safety, adapt to the complex operating conditions of special vehicles, and solve multiple defects of traditional dampers.

[0030] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the following description of the relative embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the piston head section; Figure 3 This is a schematic diagram comparing the direction of the magnetic field at the damping channel of the present invention with that of a traditional magnetorheological damper.

[0033] The components are: 1. First piston rod; 2. Upper end cap; 3. Upper dynamic seal Y-ring; 4. Upper static seal O-ring; 5. Upper dynamic seal O-ring; 6. Cylinder; 7. Upper limit ring; 8. First piston head assembly; 9. Second coil; 10. Piston internal wire channel; 11. First coil; 12. Third piston head assembly; 13. Lower end cap; 14. Connecting pipe; 15. Bottom threaded interface; 16. Wire outlet; 17. Second piston rod; 18. Lower dynamic seal Y-ring; 19. Lower dynamic seal O-ring; 20. Lower static seal O-ring; 21. Lower limit ring; 22. First magnetic ring; 23. First magnetic isolation ring; 24. Second magnetic ring; 25. Second piston head assembly; 26. Second magnetic isolation ring; 27. Third magnetic ring; 28. Top threaded interface; 29. ​​First working gap; 30. Second working gap; 31. Third working gap. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0038] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0039] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0040] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0041] This invention provides a magnetorheological damper suitable for vibration reduction and buffering, employing a dual-rod hybrid structure with two coils, one small and one large. During vibration, only the small coil is energized, causing the magnetic circuit to act on gaps 1 and 2, achieving small damping adjustment. During impact, both coils are energized, extending the magnetic circuit to gaps 1, 2, and 3, providing large damping. Simultaneously, the magnetic flux path is optimized through a magnetizing ring and a magnetic isolation ring, improving the magnetic field utilization rate at the damping channel. The piston head adopts a split design, facilitating coil assembly and wire lead-out. The sealing part uses double sealing with O-rings and Y-rings to improve reliability under impact conditions. The dual-coil and multi-working-gap design allows for precise small damping adjustment during vibration, with the small coil (first coil) operating. During impact, both coils (first and second coils) operate simultaneously, rapidly outputting greater damping, thus meeting the continuous vibration reduction and transient buffering requirements of special vehicle seats. The design incorporates the magnetizing ring and the magnetic isolation ring... By rationally arranging the magnetic field lines so that more magnetic field lines are perpendicular to the damping channel, the utilization rate of the magnetic field within the damping channel is improved, thereby enhancing the damping output capability of the magnetorheological damper. The piston head adopts a split structure design, which facilitates the installation, disassembly, and replacement of the coil, as well as the internal wiring arrangement and lead-out, reducing assembly difficulty and improving the convenience of structural implementation. The sealing part adopts a double sealing structure of O-rings and Y-rings, which can effectively reduce the risk of seal failure and magnetorheological fluid leakage under strong impact loads, thereby improving the working reliability and operational stability of the magnetorheological damper under complex working conditions.

[0042] Example 1 Please see Figure 1This invention discloses a magnetorheological damper suitable for vibration reduction and buffering, comprising a first piston rod 1, an upper end cap 2, an upper dynamic sealing Y-ring 3, an upper static sealing O-ring 4, an upper dynamic sealing O-ring 5, a cylinder 6, an upper limit ring 7, a first piston head assembly 8, a second coil 9, a piston internal wire channel 10, a first coil 11, a third piston head assembly 12, a lower end cap 13, a connecting pipe 14, a bottom threaded interface 15, a wire outlet 16, a second piston rod 17, a lower dynamic sealing Y-ring 18, a lower dynamic sealing O-ring 19, a lower static sealing O-ring 20, a lower limit ring 21, a first magnetizing ring 22, and a first magnetic isolation ring 23. The components, including the second magnetic ring 24, the second piston head assembly 25, the second magnetic isolation ring 26, the third magnetic ring 27, the top threaded interface 28, and the magnetorheological fluid, adopt a dual-rod hybrid structure. Two coils, one small and one large, are installed inside the piston head, working in conjunction with the magnetic ring and the magnetic isolation ring to construct a two-stage magnetic circuit, thereby improving the magnetic field utilization rate at the damping channel. Under vibration conditions, only the first coil 11 operates, enabling fine adjustment of small damping. Under impact conditions, both coils work together to output greater damping. The piston head adopts a split design, facilitating coil assembly and wire lead-out. Furthermore, the dynamic sealing part uses a double seal of O-rings and Y-rings, enhancing impact resistance.

[0043] The upper end cover 2 is fixedly connected to the cylinder 6 by bolts; the upper end cover 2 and the cylinder 6 are clearance-fitted and sealed by the upper static sealing O-ring 4; the upper end cover 2 and the first piston rod 1 are sealed by the upper dynamic sealing O-ring 5 and the upper dynamic sealing Y-ring 3; the first piston rod 1 and the first piston head assembly 8 are threadedly connected; the first piston head assembly 8 and the upper limit ring 7 are threadedly connected; the second piston head assembly 25 and the first piston head assembly 8 are clearance-fitted; the third piston head assembly 12 and the first piston head assembly 8 are clearance-fitted; the first magnetic ring 22 and the third piston head assembly 12 are clearance-fitted; the second magnetic ring 24 and the second piston head assembly 25 are clearance-fitted; the third magnetic ring 27 and the first piston head assembly 8 are clearance-fitted; the first magnetic isolation ring 23 is installed between the first magnetic ring 22 and the second magnetic ring 24, and is clearance-fitted with the first magnetic ring 22 and the second magnetic ring 24 through a groove; the second magnetic isolation ring 26 is installed between the third magnetic ring 27 and the second magnetic ring 24, and is clearance-fitted with the third magnetic ring 27 through a groove. The third magnetic ring 27 and the second magnetic ring 24 are fitted with a clearance; the lower limit ring 21 is threadedly connected to the first piston head component 8; the second piston rod 17 is threadedly connected to the first piston head component 8; the first coil 11 is installed between the third piston head component 12 and the second piston head component 25; the second coil 9 is installed between the second piston head component 25 and the first piston head component 8; the first coil 11 and the second coil 9 are connected to the inside of the second piston rod 17 through the piston internal wire channel 10 and are led out from the wire outlet 16; the lower end cover 13 is fitted with the cylinder 6 with a clearance; the lower end cover 13 and the cylinder 6 are sealed by the lower static sealing O-ring 20; the lower end cover 13 and the second piston rod 17 are sealed by the lower dynamic sealing O-ring 19 and the lower dynamic sealing Y-ring 18; the lower end cover 13, the connecting pipe 14 and the cylinder 6 are bolted together; the bottom threaded interface 15 is connected to the vehicle floor; the top threaded interface 28 is connected to the seat floor; the magnetorheological fluid is filled into the cylinder 6 through the upper end cover 2.

[0044] Please see Figure 2 The structural diagram shows the structure at the piston head of the magnetorheological damper, in which the third magnetic ring 27, the second magnetic ring 24, the first magnetic ring 22, and the cylinder 6 are made of high magnetic permeability material; the upper limit ring 7, the first piston head component 8, the second magnetic isolation ring 26, the first magnetic isolation ring 23, the third piston head component 12, and the second piston head component 25 are made of non-magnetic permeability material.

[0045] In this invention, the magnetorheological damper coil is fixed on the piston head component, wherein the first coil is fixed on the third piston head component, the second coil is fixed on the first piston head component, and the coil wire is led out from the wire channel inside the piston to the inside of the second piston rod, and finally led out from the wire outlet. The split piston head structure can reduce the difficulty of coil assembly.

[0046] The magnetorheological damper of this invention has two operating modes. In vibration mode, only the first coil is energized, and the first and second working gaps serve as effective damping gaps to provide smaller damping and achieve refined vibration reduction control. In impact mode, the first and second coils are energized simultaneously, and the first, second, and third working gaps serve as effective damping gaps to provide larger damping and meet impact buffering requirements.

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0048] Example 2 This embodiment optimizes the coil turns ratio and the working gap width based on Embodiment 1.

[0049] In this embodiment, the number of turns of the first coil 11 is 1 / 2 to 2 / 3 of the number of turns of the second coil 9. This design further reduces energy consumption under vibration conditions requiring only low damping. Meanwhile, the radial widths of the first working gap 29 and the second working gap 30 are 0.5~1.0 mm, while the width of the third working gap 31 is 1.0~1.5 mm. The wider third working gap, combined with the larger coil, provides greater flow capacity under impact conditions, preventing hydraulic lock-up while ensuring sufficient damping torque.

[0050] Example 3 This embodiment has been improved for extreme impact environments.

[0051] In this embodiment, the lips of the upper dynamic sealing Y-ring 3 and the lower dynamic sealing Y-ring 18 are positioned facing the high-pressure area inside the cylinder, automatically enhancing the sealing specific pressure using fluid pressure. Furthermore, a polyurethane buffer pad with a thickness of 2-5 mm is bonded to the end faces of the upper limit ring 7 and the lower limit ring 21. When the piston reaches its stroke limit, the polyurethane pad first contacts the end cap, absorbing part of the impact kinetic energy through its high elastic modulus, further protecting the piston head structure and the occupant's spine.

[0052] Example 4 Although the preferred embodiment of the present invention uses internal wiring in the piston rod, this embodiment provides an alternative solution in certain space-constrained application scenarios.

[0053] In this embodiment, the wires of the first coil 11 and the second coil 9 do not pass through the internal wire channel 10 of the piston, but instead converge and connect to a wireless signal transmitting module located in the central blind hole of the first piston head component 8. This module converts the control signal into an electromagnetic wave signal, which is received by a receiving antenna outside the cylinder, thereby completely eliminating the internal wires and the risk of wire breakage, making it suitable for ultra-long stroke or extremely high frequency vibration environments.

[0054] To verify the performance of the present invention, a finite element simulation comparison experiment was conducted.

[0055] Experimental design: Select the damper model of the present invention (experimental group) and the traditional single coil damper model (control group) of the same size, and input the same excitation current (1A, 2A, 3A) to simulate their static magnetic field distribution.

[0056] This invention improves the magnetic flux density of the damping gap by more than 40%, doubles the damping adjustment range, reduces magnetic leakage by 35%, and achieves a dual-condition switching time of less than 10ms, verifying the magnetic circuit optimization effect and the advantages of dual-condition operation.

[0057] Please see Figure 3 The figures show a comparison between the magnetic circuit distribution simulation cloud map provided in this embodiment of the invention and a traditional structure. The right figure shows the magnetic induction intensity distribution of a traditional coil magnetorheological damper, where the magnetic lines of force exhibit a large tilt angle at the damping channel, resulting in a relatively small effective magnetic flux density perpendicular to the damping channel. The left figure shows the magnetic induction intensity distribution of the dual-coil magnetorheological damper provided in this embodiment of the invention. As can be seen from the figures, guided by the magnetizing rings 22, 24, and 27, the magnetic lines of force uniformly and perpendicularly pass through the first working gap 29, the second working gap 30, and the third working gap 31, increasing the effective magnetic flux density within the working gaps by approximately 40%, thus verifying the superiority of the magnetic circuit design of this invention.

[0058] In summary, this invention provides a magnetorheological damper suitable for vibration reduction and buffering. It employs a combined structure of dual output rods, a split piston head, dual coils, and a magnetizing and insulating ring to achieve adaptive damping adjustment under both vibration and impact conditions, balancing comfort and safety. Magnetic circuit optimization ensures that magnetic field lines pass perpendicularly through the damping gap, significantly improving magnetic field utilization and damping output capacity. The split structure reduces the difficulty of coil assembly and wire lead-out, facilitating production and maintenance. The double-sealing structure significantly improves sealing reliability under impact conditions, reducing leakage risk. The material combination is reasonable, the limiting is reliable, the connection is robust, and the overall structure is rigid, long-lasting, and has a fast response. This product can be widely used in special vehicle seat suspension systems, effectively solving problems such as poor dual-condition adaptability, low magnetic field utilization, inconvenient assembly, and unreliable sealing in traditional magnetorheological dampers. It improves vehicle ride comfort and occupant safety, possessing high engineering application value and market potential.

[0059] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A magnetorheological damper suitable for vibration reduction and buffering, characterized in that, The cylinder (6) includes an upper end cap (2) and a lower end cap (13) at its two ends. The first piston rod (1) and the second piston rod (17) pass through the upper end cap (2) and the lower end cap (13) respectively and are connected to the first piston head component (8) located inside the cylinder (6). The second piston head component (25) is in clearance fit with the first piston head component (8), and the third piston head component (12) is in clearance fit with the first piston head component (8) and together with the first piston head component (8) form a split piston head. The first coil (11) is installed between the third piston head component (12) and the second piston head component (25), and the second coil (9) is installed between the second piston head component (25) and the first piston head component (8). The wires of the first coil (11) and the second coil (9) are connected to the inside of the second piston rod (17) through the wire channel (10) inside the piston and led out from the wire outlet (16). The first magnetic ring (22) is connected to the third piston head component (12). The second magnetic ring (24) and the second piston head component (25) are in clearance fit, the third magnetic ring (27) and the first piston head component (8) are in clearance fit, the first magnetic isolation ring (23) is disposed between the first magnetic ring (22) and the second magnetic ring (24), and the second magnetic isolation ring (26) is disposed between the third magnetic ring (27) and the second magnetic ring (24). A first working clearance (29) and a second working clearance (30) are formed between the piston head and the inner wall of the cylinder (6). The upper end cover (2) and the first piston rod (1) are sealed by an upper dynamic sealing O-ring (5) and an upper dynamic sealing Y-ring (3); the lower end cover (13) and the second piston rod (17) are sealed by a lower dynamic sealing O-ring (19) and a lower dynamic sealing Y-ring (18); the upper end cover (2) and the cylinder (6) are sealed by an upper static sealing O-ring (4); and the lower end cover (13) and the cylinder (6) are sealed by a lower static sealing O-ring (20).

2. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, The upper end cover (2) is fitted with the cylinder (6) with a clearance and sealed by the upper static sealing O-ring (4), and the lower end cover (13) is fitted with the cylinder (6) with a clearance and sealed by the lower static sealing O-ring (20).

3. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, The upper end cover (2) is fixedly connected to the cylinder (6) by bolts, and the lower end cover (13), connecting pipe (14) is connected to the cylinder (6) by bolts.

4. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, The first piston rod (1) is connected to the first piston head component (8) by a thread, and the second piston rod (17) is connected to the first piston head component (8) by a thread.

5. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, The upper limit ring (7) is connected to the first piston head component (8) by a thread, and the lower limit ring (21) is connected to the first piston head component (8) by a thread.

6. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, The first magnetic isolation ring (23) is installed between the first magnetic attraction ring (22) and the second magnetic attraction ring (24), and is in clearance fit with the first magnetic attraction ring (22) and the second magnetic attraction ring (24) through a groove; the second magnetic isolation ring (26) is installed between the third magnetic attraction ring (27) and the second magnetic attraction ring (24), and is in clearance fit with the third magnetic attraction ring (27) and the second magnetic attraction ring (24) through a groove.

7. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, The first coil (11) and the second coil (9) are connected to the inside of the second piston rod (17) through the piston internal wire channel (10) and led out from the wire outlet (16).

8. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, Under vibration conditions, only the first coil (11) is energized, and the first working gap (29) and the second working gap (30) serve as effective damping gaps; under impact conditions, the first coil (11) and the second coil (9) are energized simultaneously, and the first working gap (29), the second working gap (30) and the third working gap (31) serve as effective damping gaps.

9. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, The first magnetic ring (22), the second magnetic ring (24), the third magnetic ring (27) and the cylinder (6) are made of high magnetic permeability material, while the upper limit ring (7), the first piston head component (8), the second piston head component (25), the third piston head component (12), the first magnetic isolation ring (23) and the second magnetic isolation ring (26) are made of non-magnetic permeability material.

10. The magnetorheological damper suitable for vibration reduction and buffering according to claim 1, characterized in that, The bottom threaded interface (15) is used to connect to the vehicle floor, and the top threaded interface (28) is used to connect to the seat floor.

Images