Electrorheological fluid damper for automobiles
By employing multiple sealing devices and guiding mechanisms in the electrorheological damper, the problem of insufficient sealing performance of automotive dampers is solved, achieving sealing reliability and stability of damping force output, thus meeting the performance requirements during vehicle operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TONGMAI TECHNOLOGY (SHENZHEN) CO LTD
- Filing Date
- 2026-04-29
- Publication Date
- 2026-06-05
AI Technical Summary
Existing electrorheological damper sealing devices cannot meet the requirements of automobiles for damper sealing performance, especially in terms of insufficient sealing reliability when generating a large range of damping forces.
The design employs a multi-seal device, including a guide mechanism, a first oil seal mechanism, a second oil seal mechanism, and a third oil seal mechanism, which are respectively located between the guide mechanism and the piston rod, and between the guide mechanism and the inner wall of the cylinder, forming multiple seals. Combined with the design of the guide and the thrust retainer, it ensures stable sliding of the piston rod and reliable sealing.
It significantly improves the sealing reliability of the damper, extends the service life of the sealing device, ensures the stability of the damping force output, and meets the performance requirements during vehicle operation.
Smart Images
Figure CN122148695A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of damper technology, and more particularly to an electrorheological fluid damper for automobiles. Background Technology
[0002] Currently, most automotive dampers are hydraulic dampers, which generate damping force by the energy dissipated as damping fluid flows through a throttling orifice. The damping coefficient can be adjusted by changing the orifice diameter. However, hydraulic dampers are passive in their response to external vibration loads, which inevitably reduces their buffering performance and damping effect. While CDC (Continuous Damping Control System) can change the fluid flow resistance by adjusting the damper valve / throttling orifice opening, it also suffers from drawbacks such as limited damping force adjustment range, long response time, and complex control structure. To address the shortcomings of hydraulic damper structures, electromagnetic dampers using MRF (Magnetorheological Fluid) have been developed. However, existing electromagnetic dampers also suffer from drawbacks such as long response time, complex coil magnetic circuit structure, large space and weight footprint, high energy consumption for generating and maintaining the magnetic field, severe heat generation, and high maintenance requirements and costs.
[0003] Electrorheological fluids (EMFs), as intelligent materials whose viscosity, plasticity, and other rheological properties change drastically under the influence of an applied electric field, can instantly transform from a free-flowing liquid to a semi-solid, exhibiting a controllable yield strength. This morphological change is reversible with changes in the electric field. Therefore, EMF dampers, which use EMFs as damping fluids, are increasingly attracting the attention of researchers. As a novel damping structure, EMF dampers show great promise for application due to their adjustable and controllable damping force and good responsiveness.
[0004] Existing electrorheological dampers generally include a cylinder, a piston rod with a piston mounted on it, and electrodes disposed within the piston. Patent application number 201710084569.4 discloses an electrorheological damper in which only a guide sleeve is provided at the end of the cylinder. This guide sleeve slides with the piston rod, and an oil seal is provided at the intersection of the guide sleeve and the piston rod for sealing. This sealing device can meet the general application scenarios of electrorheological dampers. However, since automotive electrorheological dampers need to generate a large range of damping forces, the structure of providing a guide sleeve at the end of the cylinder and an oil seal at the intersection of the guide sleeve and the piston rod cannot meet the requirements of automotive dampers. Summary of the Invention
[0005] The main objective of this invention is to provide an automotive electrorheological damper, which aims to solve the problem that the sealing devices of existing electrorheological dampers cannot meet the automotive requirements for damper sealing performance.
[0006] To achieve the above objectives, the present invention provides an automotive electrorheological damper, comprising: a cylinder, a piston slidably disposed within the cylinder, and a piston rod connected to the piston; and further comprising: a sealing device disposed at the end of the cylinder and sealed to the cylinder, the sealing device being slidably engaged with the piston rod. The sealing device includes: A guide mechanism, wherein the piston rod passes through the guide mechanism and slides with the guide mechanism, and the guide mechanism is fixed to the inner wall of the cylinder; The first oil seal mechanism is disposed at one end of the guide mechanism and located between the guide mechanism and the piston rod, and is used for sealing; The second oil seal mechanism is located at the other end of the guide mechanism and between the guide mechanism and the piston rod, and is used for sealing. The third oil seal mechanism is disposed on the outer periphery of the guide mechanism and located between the guide mechanism and the inner wall of the cylinder, for sealing purposes; The upper end cover is fixed to one end of the guide mechanism, the piston rod passes through the upper end cover, and the upper end cover is sealed to the inner wall of the cylinder. The lower end cover is fixed to the other end of the guide mechanism, and the piston rod passes through the lower end cover.
[0007] Optionally, the guiding mechanism includes: The guide has an upper end cap and a lower end cap fixedly connected to its two ends. The outer periphery of the guide abuts against the inner wall of the cylinder. The piston rod passes through the guide. The inner wall of the guide has a mating groove. A guide ring is fixed in the mating groove, and the piston rod passes through the guide ring and slides with the guide ring.
[0008] Optionally, the first oil seal mechanism includes: A frame, fixed to one end of the guide; An oil seal is mounted on the frame and slides in conjunction with the piston rod.
[0009] Optionally, the sealing device further includes: A thrust retaining ring is disposed between the guide and the inner wall of the cylinder to prevent the guide from shifting. A sealing ring is disposed between the upper end cover and the inner wall of the cylinder.
[0010] Optionally, the piston rod has a through-hole adapter hole at its center, an insulating sleeve is fixed inside the adapter hole, a conductive core is disposed inside the insulating sleeve, and the conductive core is adapted to the piston.
[0011] Optionally, the piston includes: The piston housing is slidably disposed on the inner wall of the cylinder and fixed to the piston rod; An upper insulating sleeve is disposed inside the piston housing and located on the side where the piston housing is connected to the piston rod; A lower insulating sleeve is disposed inside the piston housing, and the lower insulating sleeve is disposed opposite to the upper insulating sleeve; An electrode is disposed inside the piston housing and located between the upper insulating sleeve and the lower insulating sleeve. A conductive core mating hole is provided in the center of the electrode. The conductive core passes through the upper insulating sleeve and is fitted into the conductive core mating hole. A working gap is reserved between the electrode and the piston housing. A piston end cap is fixed to the end of the piston housing. The piston end cap is provided with a first through hole, and the end of the piston housing is provided with a second through hole. Both the first through hole and the second through hole are connected to the working gap. As the piston moves, electrorheological fluid flows through the first through hole, the working gap, and the second through hole at both ends of the piston.
[0012] Optionally, a spring washer is also provided on the piston rod, the spring washer abutting against the top of the piston housing, and an anti-collision spring ring is provided on the spring washer.
[0013] Optionally, an airbag frame is further provided below the inner wall of the cylinder, an airbag is provided on the airbag frame, and an electrorheological fluid is provided between the airbag and the piston.
[0014] Optionally, a base is fixed to the bottom of the cylinder, and an inflation plug is provided on the base for inflating the airbag.
[0015] This invention discloses an automotive electrorheological fluid damper. By establishing a first and a second oil seal mechanism between the guide mechanism and the piston rod, and a third oil seal mechanism between the guide mechanism and the inner wall of the cylinder, a multi-layered sealing device is formed. This effectively prevents the electrorheological fluid from leaking out from the gap between the cylinder end and the piston rod and guide mechanism, significantly improving the damper's sealing reliability. The guide mechanism guides and limits the sliding of the piston rod, ensuring stable axial movement and preventing piston rod wobbling that could cause wear on the sealing device, thus extending its service life. The multi-layered sealing and guiding design ensures that the damper's sealing performance is adapted to the operating requirements of the electrorheological fluid, guaranteeing stable damping force output and meeting the damper performance requirements during vehicle operation. Attached Figure Description
[0016] Figure 1 A cross-sectional view of an automotive electrorheological damper provided in an embodiment of this application; Figure 2 This is a cross-sectional view of the lower end face of the damping piston; Figure 3 This is a cross-sectional view of the upper end face of the damping piston; Figure 4 for Figure 1 Enlarged view of part B; Figure 5 This is a schematic diagram of the conductive core structure; Figure 6 This is a schematic diagram of the cross-sectional structure of the electrode; Figure 7 for Figure 1 Enlarged view of part A; In the diagram, 1. Cylinder body; 101. Airbag frame; 102. Airbag; 103. Base; 104. Inflation plug; 2. Piston; 201. Piston housing; 202. Upper insulating sleeve; 203. Lower insulating sleeve; 204. Electrode; 205. Working gap; 206. Piston end cap; 3. Piston rod; 301. Insulating sleeve; 302. Conductive core; 303. Spring washer; 304. Anti-collision spring ring; 4. Sealing device; 401. Guide mechanism; 4011. Guide; 4012. Guide ring; 402. First oil seal mechanism; 4021. Frame; 4022. Oil seal; 403. Second oil seal mechanism; 404. Third oil seal mechanism; 405. Upper end cap; 406. Lower end cap; 407. Thrust ring; 408. Sealing ring. Detailed Implementation
[0017] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0018] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.
[0019] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0020] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.
[0021] Please see Figures 1 to 7 This invention provides an automotive electrorheological damper, which may include: a cylinder 1, a piston 2 slidably disposed within the cylinder 1, and a piston rod 3 connected to the piston 2; and a sealing device 4 disposed at the end of the cylinder 1 and sealed to the cylinder 1, the sealing device 4 being slidably engaged with the piston rod 3; the sealing device 4 includes: a guide mechanism 401, a first oil seal mechanism 402, a second oil seal mechanism 403, a third oil seal mechanism 404, an upper end cover 405, and a lower end cover 406, wherein the piston rod 3 passes through the guide mechanism 401 and is slidably engaged with the guide mechanism 401, the guide mechanism 401 being fixed within the cylinder 1. On the wall; the first oil seal mechanism 402 is disposed at one end of the guide mechanism 401 and is located between the guide mechanism 401 and the piston rod 3, for sealing; the second oil seal mechanism 403 is disposed at the other end of the guide mechanism 401 and is located between the guide mechanism 401 and the piston rod 3, for sealing; the third oil seal mechanism 404 is disposed on the outer periphery of the guide mechanism 401 and is located between the guide mechanism 401 and the inner wall of the cylinder 1, for sealing; the upper end cover 405 is fixed to one end of the guide mechanism 401, the piston rod 3 passes through the upper end cover 405, and the upper end cover 405 is sealed to the inner wall of the cylinder 1; the lower end cover 406 is fixed to the other end of the guide mechanism 401, and the piston rod 3 passes through the lower end cover 406.
[0022] In this embodiment, by setting a first oil seal mechanism 402 and a second oil seal mechanism 403 between the guide mechanism 401 and the piston rod 3, and a third oil seal mechanism 404 between the guide mechanism 401 and the inner wall of the cylinder 1, a multi-seal device 4 is formed. This effectively prevents the electrorheological fluid from leaking out from the fitting gap between the end of the cylinder 1 and the piston rod 3 and the guide mechanism 401, significantly improving the sealing reliability of the damper. The guide mechanism 401 can guide and limit the sliding of the piston rod 3, ensuring that the piston rod 3 moves stably along the axial direction, preventing the piston rod 3 from shaking and causing wear on the sealing device 4, thus extending the service life of the sealing device 4. The design of multiple seals and guidance makes the sealing performance of the damper adaptable to the working requirements of the electrorheological fluid, ensuring stable damping force output, and meeting the damper performance requirements during vehicle operation.
[0023] Please see Figure 7 In some possible implementations, the guide mechanism 401 may include: a guide 4011 and a guide ring 4012, wherein the upper end cover 405 and the lower end cover 406 are respectively fixedly connected to the two ends of the guide 4011, the outer periphery of the guide 4011 abuts against the inner wall of the cylinder 1, the piston rod 3 passes through the guide 4011, and the inner wall of the guide 4011 is provided with a mating groove; the guide ring 4012 is fixed in the mating groove, and the piston rod 3 passes through the guide ring 4012 and slides with the guide ring 4012.
[0024] Specifically, the guide ring 4012 guides the piston rod 3 to slide, which can limit the radial wobble of the piston rod 3, ensure the stable axial sliding of the piston rod 3, and prevent the piston rod 3 from causing friction damage to the oil seal mechanism. The guide 4011 itself provides the installation and positioning foundation for the guide ring 4012 and the oil seal mechanism. The structure is compact, highly integrated, and easy to assemble.
[0025] Please see Figure 7 In some embodiments, the first oil seal mechanism 402 may include a frame 4021 and an oil seal 4022, wherein the frame 4021 is fixed to one end of the guide 4011; the oil seal 4022 is disposed on the frame 4021 and slides in cooperation with the piston rod 3.
[0026] In this embodiment, the skeleton 4021 provides stable positioning support for the oil seal 4022, ensuring that the oil seal 4022 is always maintained in the preset sealing position. The oil seal 4022 is tightly fitted to the circumference of the piston rod 3, and can continuously achieve sealing during the sliding process of the piston rod 3. The first oil seal can initially block the electrorheological fluid from leaking outward, and the sealing reliability is higher.
[0027] Please see Figure 7In some possible implementations, the sealing device 4 may also include a thrust ring 407 and a sealing ring 408, wherein the thrust ring 407 is disposed between the guide 4011 and the inner wall of the cylinder 1 to prevent the guide 4011 from shifting; and the sealing ring 408 is disposed between the upper end cover 405 and the inner wall of the cylinder 1.
[0028] Specifically, the thrust retainer 407 can firmly lock the guide 4011 in a preset position inside the cylinder 1, preventing the guide 4011 from axially moving after the damper has been working for a long time, which would cause the fit clearance of each sealing surface to change, thus effectively improving the stability of the sealing structure; a sealing ring 408 is added between the upper end cover 405 and the inner wall of the cylinder 1, which can work with the third oil seal mechanism 404 to form a double axial seal, further blocking the path of electrorheological fluid leakage to the outside, and the sealing effect is better.
[0029] The guide 4011 is designed with a bidirectional limiting structure of thrust retainer 407 and upper end cover 405, achieving a reliable axial guiding structure that can be disassembled and replaced. The outer wall of the guide 4011 and the inner wall of the cylinder 1 are designed with corresponding mounting grooves for the thrust retainer 407 at the locking position. During assembly, the guide 4011 is first pressed into the cylinder 1. When the end face of the guide 4011 passes through the thrust retainer groove on the inner wall of the cylinder 1, sufficient space for the thrust retainer 407 to be installed is exposed, allowing the thrust retainer 407 to be smoothly installed into the groove. After the thrust retainer 407 is installed in place, the remaining space allows the guide 4011 to be pulled outwards to the matching position of the thrust retainer 407, preventing it from being pulled out further, thus achieving a limiting function from the inside out. This thrust function is entirely supported by the high shear strength of the thrust retainer 407 material itself, far exceeding the upper limit of the damper's working strength, resulting in very high reliability.
[0030] In addition, after the thrust retainer ring 407 is installed in place, the upper end cover 405 is inserted from the end of the piston rod 3 and moved to the end face of the guide 4011, and is connected to the guide 4011 by threads, which also serves to fix the first oil seal mechanism 402. In terms of design, the thread length between the guide 4011 and the upper end cover 405 is slightly longer than the length of the upper end cover 405 moving to the end face of the cylinder 1, thereby ensuring that the guide 4011 can be screwed into the position of pressing the end face of the cylinder 1 and locked, thereby preventing the guide 4011 from moving inward, realizing the limiting function in the outside to the inside direction, and at the same time, in conjunction with the thrust retainer ring 407, a certain preload is applied to the guide 4011 to prevent shaking.
[0031] Please see Figure 4 In some embodiments, a through-hole is provided in the center of the piston rod 3, an insulating sleeve 301 is fixed in the adapter hole, a conductive core 302 is provided in the insulating sleeve 301, and the conductive core 302 is adapted to the piston 2.
[0032] In this process, by setting an insulating sleeve 301 to prevent the conductive core 302 from conducting with the piston rod 3, the conductive core 302 is adapted to the piston 2 to achieve current conduction.
[0033] Please see Figure 4 In some possible implementations, the piston 2 may include: a piston housing 201, an upper insulating sleeve 202, a lower insulating sleeve 203, an electrode 204, and a piston end cap 206. The piston housing 201 is slidably disposed on the inner wall of the cylinder 1 and fixed to the piston rod 3. The upper insulating sleeve 202 is disposed inside the piston housing 201 and located on the side where the piston housing 201 connects to the piston rod 3. The lower insulating sleeve 203 is disposed inside the piston housing 201 and is disposed opposite to the upper insulating sleeve 202. The electrode 204 is disposed inside the piston housing 201 and located between the upper insulating sleeve 202 and the piston rod 3. Between the lower insulating sleeves 203, a conductive core mating hole is opened in the center of the electrode 204. The conductive core 302 passes through the upper insulating sleeve 202 and is fitted into the conductive core mating hole. A working gap 205 is reserved between the electrode 204 and the piston housing 201. The piston end cap 206 is fixed to the end of the piston housing 201. A first through hole is provided on the piston end cap 206, and a second through hole is provided at the end of the piston housing 201. Both the first through hole and the second through hole are connected to the working gap 205. As the piston 2 moves, the electrorheological fluid flows through the first through hole, the working gap 205 and the second through hole at both ends of the piston 2.
[0034] The piston housing 201 is threaded to the piston rod 3, with threadlocker applied to the threaded surface. The conductive core 302 and electrode 204 are interference-fitted. The contact surface between the piston housing 201 and the upper insulating sleeve 202 is filled with ceramic sintered material and bonded at high temperature. Simultaneously, the contact surfaces between the electrode 204 and the upper and lower insulating sleeves 202 and 203 are also filled with ceramic sintered material and bonded at high temperature. The piston end cap 206 is threaded to the piston housing 201, with threadlocker applied to the threaded surface.
[0035] Piston 2 employs a design consisting of a negative electrode piston shell, an upper ceramic insulating sleeve, a high-voltage positive electrode, a lower ceramic insulating sleeve, and a negative electrode piston end cap. Both the positive and negative electrodes are made of Kova alloy, which has a thermal expansion coefficient close to that of the insulating ceramic. Ceramic sintered material is filled between the electrode 204 and the ceramic insulating sleeve, and the damping piston is fixed as a whole through high-temperature sintering, forming a modular design. This provides very high fixing strength, sealing performance, wear resistance, and insulation. Furthermore, because the thermal expansion coefficients of Kova alloy and ceramic materials are close, this design effectively avoids component failure caused by temperature variations. This design is the first of its kind in similar designs. In addition, the structural forms of each component in this invention can be mass-produced through casting and common machining processes, demonstrating very high market application prospects.
[0036] The conductive core 302 and the electrode 204 are connected by a metal-metal elastic pressure connection, avoiding the problems of inconvenient assembly, complex welding process, easy breakage, and poor replaceability caused by welding soft wires in previous designs. The conductive core 302 is designed with a flower-shaped expansion structure at its end. During assembly, the conductive core 302 and the insulating sleeve 301 are first assembled and fixed in the piston rod 3, and then they are screwed together into the modular piston to complete the assembly, eliminating the need for welding to form a permanent connection as in similar designs. Furthermore, in case the damping structure is damaged, the piston rod 3 can be unscrewed to replace the piston assembly, offering a level of process convenience not found in other designs.
[0037] Please see Figure 1 , Figure 7 In some possible implementations, a spring washer 303 is also provided on the piston rod 3, the spring washer 303 abuts against the top of the piston housing 201, and an anti-collision spring ring 304 is provided on the spring washer 303.
[0038] In this embodiment, a spring washer 303 is pressed between the piston rod 3 and the piston housing 201, primarily to prevent structural loosening. The anti-collision spring ring 304 is directly inserted into the piston rod 3, which helps prevent the piston 2 from directly colliding with the sealing device 4.
[0039] Please see Figure 1 In some embodiments, an airbag frame 101 is also provided below the inner wall of the cylinder 1, an airbag 102 is provided on the airbag frame 101, and an electrorheological fluid is provided between the airbag 102 and the piston 2.
[0040] Specifically, the airbag 102 is inserted into the airbag frame 101, and the two are inserted into the cylinder 1 as a whole. The airbag 102 is filled with inert gas.
[0041] Please see Figure 1 In some possible implementations, a base 103 is fixed to the bottom of the cylinder 1, and an inflation plug 104 is provided on the base 103. The inflation plug 104 is used to inflate the airbag 102.
[0042] The inflation plug 104 is threadedly connected to the base 103, and thread sealant is applied to the threaded surface. The base 103 is firmly welded to the cylinder body 1.
[0043] Furthermore, the main function of this invention is to control the damping force generated by the damper through an external voltage. Figure 4A working gap 205 of approximately 0.5–2 mm is formed between the piston housing 201 and the electrode 204. When the ERF (Electrorheological Fluid) material in the damper cylinder flows through the working gap 205, the viscosity of the material itself generates a resistance opposite to the overall compression or tension direction of the damper, which is the damping force. When an external voltage is applied to the electrode 204 through the conductive core 302, the electrode 204 acts as the positive electrode and the piston housing 201 acts as the negative electrode. A uniform electric field is formed in the annular working gap 205. The strength of the electric field is the ratio of the voltage difference between the electrode 204 and the piston housing 201 to the distance of the working gap 205. As the electric field strength increases, the apparent viscosity of the ERF material also increases, accompanied by the generation of the material's yield strength. When the damper is working, the piston 2 moves axially within the cylinder 1, forcing the ERF material to flow through the working gap 205. At this time, the viscosity and yield strength of the material generate shear forces on both sides of the working gap 205, which manifest as variable damping force. The voltage applied to electrode 204 is externally applied and can be adjusted via power supply output. This allows for adjustment of the apparent viscosity and yield strength of the ERF material, thereby regulating the damping force. Furthermore, since there is a linear, nonlinear, or combined relationship between the apparent viscosity and yield strength of the ERF material and the applied electric field, a corresponding relationship also exists between the generated damping force and the applied electric field. Therefore, the strength of the damping force is specifically controllable.
[0044] Furthermore, due to the reversible property of ERF materials to recover their initial flow state after power failure, the damping force change generated by this invention is also reversible. In other words, this invention can generate a relatively large damping force by applying a high voltage, and can also reduce the damping force by reducing or disconnecting the applied voltage. The damping force adjustment process achieved by this invention is repeatable.
[0045] It should be noted that the damping force generated by the damper of the present invention is related not only to the applied voltage, but also to the specific mechanical structure dimensions, the stretching or compression position of the damper, and the instantaneous speed of the stretching or compression of the damper.
[0046] In terms of structural dimensions, under the premise that other structural parameters remain unchanged in this invention, the longer the length of the working gap 205, that is, the longer the length of the electrode 204 and the piston housing 201, the longer the axial path through which the ERF material generates resistance. The damping force contributed by the viscosity of the ERF material when no voltage is applied is greater. At the same time, the change in damping force caused by the change in viscosity and yield strength of the ERF material under energized conditions is also greater. On the other hand, the larger the cross-sectional area of the working gap 205, that is, the larger the diameter of the electrode 204 and the piston housing 201, the larger the flow area of the ERF material, the more obvious the parallel effect of the flow path, and the relatively smaller the damping force when no voltage is applied.
[0047] Regarding the dependence of the damper's tension or compression position, since the air bladder 102 in the structure proposed in this invention is filled with inert gas, the change in the internal volume of the cavity when the damper is stretched or compressed will cause a change in the pressure in the air bladder 102, thereby changing the pressure of the ERF material in the cylinder 1. The axial force difference caused by the difference in cross-sectional areas on both sides of the piston 2 will also change accordingly, thus affecting the magnitude of the damping force. Specifically, the greater the compression of the damper, the higher the pressure in the air bladder 102, and the greater the outward pushing force generated by the damper; conversely, the smaller the compression of the damper, the closer the pressure in the air bladder 102 is to the initial injection pressure, and the smaller the outward pushing force generated by the damper.
[0048] The instantaneous velocity of the damper during stretching or compression determines the instantaneous flow rate through the working gap 205, which in turn determines the flow velocity of the ERF material within the working gap 205. A higher flow velocity results in a greater resistance contribution from the viscosity of the ERF material. Specifically, when the damping piston moves axially within the cylinder 1, the faster the movement, the greater the instantaneous flow velocity of the ERF material within the working gap 205 formed by the electrode 204 and the piston housing 201. This results in greater resistance from the viscosity of the ERF material and a greater instantaneous damping force generated by the damper as a whole. Conversely, when the axial movement speed of the piston 2 is relatively low, the instantaneous flow velocity of the ERF material within the working gap 205 is also relatively low, the resistance from the viscosity of the ERF material is relatively low, and the overall damping force generated by the damper is also relatively low.
[0049] The damping force generated by the damper during operation is jointly determined by several factors, including the inherent properties of the ERF material, the characteristics of the ERF material's response to the electric field, the applied electric field, the dimensions of the mechanical structure, the stretching or compression position of the damper, the initial pressure of the inert gas inside the airbag 102, and the instantaneous speed of the stretching or compression of the damper. Among these, the characteristics of the ERF material's response to the electric field and the applied electric field are the decisive factors in achieving the controllable damping force characteristics described in this invention.
[0050] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.
Claims
1. An automotive electrorheological damper, comprising a cylinder, a piston slidably disposed within the cylinder, and a piston rod connected to the piston, characterized in that, Also includes: A sealing device is disposed at the end of the cylinder body and is sealed to the cylinder body; the sealing device is slidably engaged with the piston rod. The sealing device includes: A guide mechanism, wherein the piston rod passes through the guide mechanism and slides with the guide mechanism, and the guide mechanism is fixed to the inner wall of the cylinder; The first oil seal mechanism is disposed at one end of the guide mechanism and located between the guide mechanism and the piston rod, and is used for sealing; The second oil seal mechanism is located at the other end of the guide mechanism and between the guide mechanism and the piston rod, and is used for sealing. The third oil seal mechanism is disposed on the outer periphery of the guide mechanism and located between the guide mechanism and the inner wall of the cylinder, for sealing purposes; The upper end cover is fixed to one end of the guide mechanism, the piston rod passes through the upper end cover, and the upper end cover is sealed to the inner wall of the cylinder. The lower end cover is fixed to the other end of the guide mechanism, and the piston rod passes through the lower end cover.
2. The automotive electrorheological damper according to claim 1, characterized in that, The guiding mechanism includes: The guide has an upper end cap and a lower end cap fixedly connected to its two ends. The outer periphery of the guide abuts against the inner wall of the cylinder. The piston rod passes through the guide. The inner wall of the guide has a mating groove. A guide ring is fixed in the mating groove, and the piston rod passes through the guide ring and slides with the guide ring.
3. The automotive electrorheological damper according to claim 2, characterized in that, The first oil seal mechanism includes: A frame is fixed to one end of the guide; An oil seal is mounted on the frame and slides in conjunction with the piston rod.
4. The automotive electrorheological damper according to claim 2, characterized in that, The sealing device further includes: A thrust retaining ring is disposed between the guide and the inner wall of the cylinder to prevent the guide from shifting. A sealing ring is disposed between the upper end cover and the inner wall of the cylinder.
5. The automotive electrorheological damper according to claim 1, characterized in that, The piston rod has a through-hole at its center, an insulating sleeve is fixed inside the adapter hole, and a conductive core is installed inside the insulating sleeve. The conductive core is adapted to the piston.
6. The automotive electrorheological damper according to claim 5, characterized in that, The piston includes: The piston housing is slidably disposed on the inner wall of the cylinder and fixed to the piston rod; An upper insulating sleeve is disposed inside the piston housing and located on the side where the piston housing is connected to the piston rod; A lower insulating sleeve is disposed inside the piston housing, and the lower insulating sleeve is disposed opposite to the upper insulating sleeve; An electrode is disposed inside the piston housing and located between the upper insulating sleeve and the lower insulating sleeve. A conductive core mating hole is provided in the center of the electrode. The conductive core passes through the upper insulating sleeve and is fitted into the conductive core mating hole. A working gap is reserved between the electrode and the piston housing. A piston end cap is fixed to the end of the piston housing. The piston end cap is provided with a first through hole, and the end of the piston housing is provided with a second through hole. Both the first through hole and the second through hole are connected to the working gap. As the piston moves, electrorheological fluid flows through the first through hole, the working gap, and the second through hole at both ends of the piston.
7. The automotive electrorheological damper according to claim 6, characterized in that, The piston rod is also provided with a spring washer, which abuts against the top of the piston housing, and the spring washer is provided with an anti-collision spring ring.
8. The automotive electrorheological damper according to claim 1, characterized in that, An airbag frame is also provided below the inner wall of the cylinder, and an airbag is provided on the airbag frame. An electrorheological fluid is provided between the airbag and the piston.
9. The automotive electrorheological damper according to claim 8, characterized in that, The bottom of the cylinder is fixed with a base, and an inflation plug is provided on the base. The inflation plug is used to inflate the airbag.