Large-stroke double cylinder type magneto-rheological damper

Abstract

The utility model discloses a big stroke double cylinder formula magnetorheological damper, including inner tube and outer tube, the inner tube inside is equipped with piston subassembly, and the inner tube fills magnetorheological fluid, be equipped with a plurality of damping passage that penetrates piston on the piston subassembly, and the both ends of damping passage are equipped with the check valve piece that opens and shuts in single direction respectively, the cylindrical lateral surface of the upper and lower ends of inner tube sets up the opening respectively, as the opening of magnetorheological fluid backflow channel, the clearance is left between the inner tube and outer tube, as the backflow channel of magnetorheological fluid, and the upper and lower openings of backflow channel and inner tube intercommunication. Through the check valve piece on the piston realizes the asymmetric property of damper's compression damping force and tensile damping force, so that the car of carrying this magnetorheological damper can also obtain good ride smoothness when bumping road condition, the utility model solves the problem that magnetorheological fluid damper increases the minimum damping force while increasing the maximum damping force.

Description

Technical Field

[0001] This utility model relates to the field of vibration dampers, and in particular to a magnetorheological vibration damper with a dual-cylinder layout and asymmetric damping characteristic piston assembly. Background Technology

[0002] The performance of the suspension system has a significant impact on the ride comfort of a vehicle. To improve ride comfort, shock absorbers are typically used in the suspension system to dampen vibrations. Currently, the mainstream shock absorbers on the market are mainly divided into passive, semi-active, and fully active shock absorbers. Semi-active shock absorbers are widely used due to their cost advantages and mature technology. The mainstream semi-active shock absorbers currently include continuously adjustable damping (CDC) shock absorbers and magnetorheological (MRC) shock absorbers. Compared to continuously adjustable damping shock absorbers, magnetorheological shock absorbers do not require complex valve systems and have a faster response speed. However, current magnetorheological dampers still have a relatively short piston stroke. The structure of magnetorheological shock absorbers is mainly designed to increase damping, but this leads to a corresponding increase in the minimum damping force under passive conditions, which also has a certain impact on vehicle ride comfort. Therefore, research on magnetorheological shock absorber structures with piston assemblies containing asymmetric damping characteristics that have extremely low damping force under passive conditions and can solve the problem of damping force asymmetry under compression and tension has become a research hotspot.

[0003] Magnetorheological dampers can be classified into single-cylinder and double-cylinder types according to their cylinder structure. A single-cylinder magnetorheological damper consists of a piston rod, a floating piston (or air bladder), and a piston assembly. The magnetorheological fluid in the upper and lower chambers typically flows through a magnetorheological fluid damping channel on the piston assembly. The damping force of the magnetorheological fluid flowing through the damping channel is controlled by the strength of the magnetic field generated by energizing a cylindrical coil within the piston groove. However, in use, due to the limited volume of the piston assembly, the internal damping channel of the piston cannot be set too high, resulting in a certain damping force even when the magnetorheological fluid is not passively energized. To solve this problem, we designed a double-cylinder damper, relocating the magnetorheological fluid return channel from the upper and lower chambers of the inner cylinder to the space between the inner and outer cylinders.

[0004] In a magnetorheological damper, the magnetorheological fluid is a free-flowing Newtonian fluid when there is no magnetic field. Under the influence of an applied magnetic field, the magnetorheological fluid undergoes a material phase transition. The magnetic particles in the liquid align in a regular manner along the direction of the magnetic field, forming a chain-like structure, which in turn generates yield stress similar to that of a plastic solid. At this point, the magnetorheological fluid exhibits the characteristics of a Bingham fluid, i.e., the magnetorheological effect. This dynamic transformation process has three significant characteristics: rapid response, reversible state, and controllable magnetic field. Utility Model Content

[0005] The technical problem solved by this utility model is to address the defects and deficiencies of the existing technology by providing an asymmetric piston assembly that can realize the asymmetric damping characteristics of a magnetorheological damper. The asymmetry between the compressive damping force and the tensile damping force of the damper is achieved through a one-way valve plate on the piston, so that the car equipped with the magnetorheological damper can obtain good driving smoothness even on bumpy roads. This utility model solves the problem of increasing the minimum damping force while increasing the maximum damping force of the magnetorheological damper.

[0006] To achieve the above-mentioned objectives, this utility model adopts the following technical solution: A long-stroke twin-cylinder magnetorheological damper includes an inner cylinder and an outer cylinder, with the outer cylinder containing the inner cylinder. The inner cylinder is equipped with a piston assembly, and the piston assembly is provided with several damping channels that penetrate the piston. One-way valve plates that open and close in one direction are provided at both ends of the damping channels. The inner cylinder has openings on its cylindrical sides at both the top and bottom ends, which serve as openings for the magnetorheological fluid return channel. A gap is left between the inner cylinder and the outer cylinder, which serves as the return channel for the magnetorheological fluid. The return channel is connected to the top and bottom openings of the inner cylinder. The inner cylinder is provided with a floating piston or air bladder at the end away from the piston assembly. The opening of the magnetorheological fluid return channel on the lower wall of the inner cylinder is located above the floating piston or air bladder. The inner cylinder above the floating piston or air bladder is filled with magnetorheological fluid. A compensation chamber is formed below the floating piston or air bladder and is filled with high-pressure inert gas.

[0007] Further technology of this utility model: Preferably, the piston assembly includes an asymmetric piston body and a piston rod fixedly connected to the piston body. One end of the piston body and the piston rod are fixedly connected, and an opening is provided at the top of the inner cylinder to allow the piston rod to move freely.

[0008] Preferably, the piston body is provided with an elastic reset guide mechanism at each of the two one-way valve plates, which closes the valve plates in a static state and restricts the rotation of the one-way valve plates. The elastic reset guide mechanism at each of the two one-way valve plates has a valve plate opening and closing space that allows the one-way valve plates to open and close.

[0009] Preferably, the damping channels are evenly distributed around the piston rod.

[0010] Preferably, the damping channel and the magnetorheological fluid return channel are both filled with magnetorheological fluid, and the magnetorheological fluid circulates through the damping channel inside the piston and the return channel between the two cylinders.

[0011] Preferably, the other end of the piston rod extends outside the inner cylinder of the shock absorber, and a piston rod sealing assembly is installed at the upper opening of the inner cylinder.

[0012] Preferably, the outer wall of the inner cylinder is provided with a plurality of coil mounting slots, and a cylindrical coil is provided in the coil mounting slot. The cylindrical coil is connected to an external controller through a control line, and the control line is led out through the outer cylinder and connected to an external power source.

[0013] The beneficial effects of this utility model are: This invention can effectively improve the stiffness of the suspension during the compression stroke and increase the damping force during the extension stroke by cooperating with the one-way valve plates at both ends of the damping channel on the piston assembly and the energized cylindrical coil in the groove on the outer side of the inner cylinder. By controlling the current through the cylindrical coil, the stiffness and damping force of the magnetorheological damper during the compression and extension strokes can be flexibly adjusted, thereby improving the ride smoothness of the vehicle on bumpy roads.

[0014] This utility model's large-stroke twin-cylinder magnetorheological damper adopts an inner and outer twin-cylinder layout, which can transfer the cylindrical coil originally wrapped in the piston groove to the groove on the outer side of the inner cylinder. This reduces the required volume of the piston. In magnetorheological dampers with the same external dimensions, the stroke of the damper is increased due to the reduction in the axial dimension of the piston, which can better adapt to various complex road conditions.

[0015] This novel magnetorheological damper employs a double-cylinder layout, expanding the original single-type magnetorheological fluid damping channel within the piston assembly into two types. One type is a magnetorheological fluid return channel located between the inner and outer cylinders, connecting the upper and lower reservoirs through openings at both ends of the inner cylinder. This channel has a larger flow rate than the damping channel inside the piston, and the magnetorheological fluid flowing through this return channel is influenced by the magnetic field generated by the cylindrical coil located in the groove on the outer side of the inner cylinder. The other type is a damping channel located within the piston assembly, with asymmetrical one-way valves installed at both ends. The plate allows for asymmetrical adjustment of the damping force and stiffness during compression and extension strokes. Because the flow path of the magnetorheological fluid is increased, and the flow rate of the magnetorheological fluid through the return channel is greater than that through the piston assembly, when the cylindrical coil is not energized, there is no magnetic field affecting the magnetorheological fluid. At this time, the magnetorheological fluid can flow smoothly in the upper and lower reservoirs, and the passive damping force can be minimized. This effectively solves the problem in current magnetorheological vibration damper structural designs where the increase in the maximum damping force of the magnetorheological fluid leads to an increase in the minimum damping force. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a cross-sectional view of the structure of a utility model large-stroke double-cylinder magnetorheological vibration damper.

[0018] Figure 2 This is a cross-sectional view of the internal structure of an asymmetric piston in a practical magnetorheological damper.

[0019] Figure 3 This is a cross-sectional view of a utility model magnetorheological vibration damper with an airbag.

[0020] The following components are labeled in the diagram: 1 Inner cylinder, 2 Outer cylinder, 3 Piston assembly, 4 Piston rod, 5 Return channel, 6 Upper connector, 7 Lower connector, 8 Piston body, 9 Upper connecting ring, 10 Damping channel, 11 One-way valve plate, 12 Elastic reset guide mechanism, 13 Coil mounting groove, 14 Lower connecting ring, 15 Guide bushing, 16 Floating piston, 17 Airbag, 18 Cylindrical coil. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0022] Example 1: Please refer to Figure 1 This embodiment provides a large-stroke twin-cylinder magnetorheological damper structure, including an inner cylinder 1 and an outer cylinder 2. The bottom of the outer cylinder 2 is fixedly connected to the lower connecting ring 14. The upper part of the inner cylinder 2 is provided with a guide bushing 15 that supports and guides the piston rod 4. The guide bushing 15 is fixedly connected to the upper connecting piece 6. The lower part of the inner cylinder 2 is provided with a lower connecting piece 7. The inner cylinder 1 and the outer cylinder 2 are fixed by the upper connecting piece 6 and the lower connecting piece 7.

[0023] The inner cylinder 1 is equipped with a piston assembly 3 and filled with magnetorheological fluid. The outer wall of the inner cylinder 1 is provided with several coil mounting slots 13. The coil mounting slots 13 are provided with cylindrical coils 18. The cylindrical coils are connected to an external controller through control lines. The control lines are led out through the outer cylinder 2 and connected to an external power source. The piston assembly 3 is provided with several damping channels 10 that penetrate the piston. The damping channels 10 are evenly distributed around the piston rod 4. One-way valve plates 11 that open and close in one direction are provided at both ends of the damping channels 10. The inner cylinder 1 has openings on its cylindrical sides at both ends, which serve as openings for the magnetorheological fluid return channel 5. A gap is left between the inner cylinder 1 and the outer cylinder 2, which serves as the magnetorheological fluid return channel 5. The return channel 5 is connected to the upper and lower openings of the inner cylinder 1.

[0024] The piston assembly 3 includes an asymmetric piston body 8 and a piston rod 4 fixedly connected to the piston body 8. One end of the piston body 8 is fixedly connected to the piston rod 4, and an opening is provided at the top of the inner cylinder 1 to allow the piston rod 4 to move freely. A piston rod 4 sealing assembly is installed at the upper opening of the inner cylinder 1. The other end of the piston rod 4 extends out of the inner cylinder 1 of the shock absorber and is fixedly connected to the upper connecting ring 9. The twin-tube shock absorber is fixed by the upper piston ring and the lower piston ring.

[0025] The damping channel 10 and the magnetorheological fluid return channel 5 are both filled with magnetorheological fluid, and the magnetorheological fluid circulates through the damping channel 10 inside the piston and the return channel 5 between the two cylinders.

[0026] A floating piston 16 is provided at the end of the inner cylinder 1 away from the piston body 8, and the opening of the magnetorheological fluid return channel 5 on the lower wall of the inner cylinder 1 is located above the floating piston 16. The piston assembly 3 is located above the floating piston 16, and there is a certain space between the piston assembly 3 and the floating piston 16. The outer wall of the floating piston 16 and the inner wall of the inner cylinder are slidably sealed, which can separate the magnetorheological fluid above from the inert gas below.

[0027] An upper liquid storage chamber is formed above the piston assembly 3, and a lower liquid storage chamber is formed between the piston assembly 3 and the floating piston 16. A compensation gas chamber is formed below the floating piston 16, and the compensation gas chamber is filled with high-pressure inert gas. Magnetorheological fluid is filled in the upper and lower liquid storage chambers. The magnetorheological fluid in the upper and lower liquid storage chambers is connected to the return channel 5 between the inner and outer cylinders 2 through the opening of the inner cylinder 1. A cylindrical coil 18 is installed in the coil mounting groove 13 of the inner cylinder 1. When the cylindrical coil 18 is energized, a magnetic field is generated, which changes the characteristics of the magnetorheological fluid in the return channel 5, thereby controlling the damping and stiffness of the magnetorheological suspension.

[0028] like Figure 2The piston body 8 is provided with several damping channels 10 that penetrate the piston. One-way valve plates 11 that open and close in one direction are provided at both ends of the damping channels 10. The piston body 8 is provided with elastic reset guide mechanisms 12 at the two one-way valve plates 11, which close the valve plates in a static state and can restrict the rotation of the one-way valve plates 11. The elastic reset guide mechanisms 12 at the two one-way valve plates 11 are provided with valve plate opening and closing space that allows the one-way valve plates 11 to open and close. The one-way valve plate 11 is equipped with a limit block, which allows the valve plate to open in one direction only. When the damper piston moves downward during the compression stroke, the oil in the lower reservoir can return to the upper reservoir through the magnetorheological fluid return channel 5 between the inner and outer cylinders 2. This energizes the cylindrical coil 18 in the coil mounting groove 13 on the outer side of the inner cylinder 1 to generate a magnetic field, which slows down the return speed of the magnetorheological fluid and increases the pressure of the magnetorheological fluid in the lower reservoir. When the pressure reaches a certain level, it overcomes the resistance of the elastic deformation element installed between the piston body 8 and the one-way valve plate 11, opening the one-way valve plate 11 upward. The magnetorheological fluid in the lower reservoir can then reach the upper reservoir from the damping channel 10 in the piston, which can increase the stiffness of the magnetorheological damper during the compression stroke.

[0029] When the damper piston extends upwards, the pressure of the magnetorheological fluid in the upper reservoir increases, pressing the one-way valve 11 tightly against the limiting block of the piston body 8. With the one-way valve 11 closed, the magnetorheological fluid cannot return to the lower reservoir through the damping channel 10 inside the piston. The fluid in the upper reservoir can only return to the lower reservoir through the return channel 5 between the inner and outer cylinders 2. The magnetorheological fluid flowing through the return channel 5 is affected by the magnetic field generated by the energized cylindrical coil 18, causing the magnetorheological suspension to extend slowly. This asymmetric damping characteristic significantly improves the problem of increasing both the maximum and minimum damping forces of the damper while simultaneously increasing the maximum damping force. When the magnetorheological damper is in a passive state, the cylindrical coil 18 is not energized and has no effect on the magnetorheological fluid flowing through the return channel 5. This allows the magnetorheological fluid to flow freely between the upper and lower reservoirs in the passive state, minimizing the passive damping force.

[0030] Example 2: As Figure 3 This embodiment provides a large-stroke dual-cylinder magnetorheological damper structure, which is a magnetorheological damper with an air bladder 17. The difference from the embodiment is that the floating piston 16 is replaced by the air bladder 17, and the air bladder 17 forms a compensation air chamber. The rest of the structure and principle are the same as in embodiment 1.

[0031] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0032] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 utility model according to the specific circumstances.

[0033] The above description is merely an example and illustration of the structure of this utility model. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the structure of the utility model or exceed the scope defined in the claims, they should all fall within the protection scope of this utility model.

Claims

1. A long-stroke twin-cylinder magnetorheological vibration damper, characterized in that, It includes an inner cylinder (1) and an outer cylinder (2), with the outer cylinder (2) containing the inner cylinder (1); The inner cylinder (1) is provided with a piston assembly (3), and the piston assembly (3) is provided with a plurality of damping channels (10) that penetrate the piston. One-way valve plates (11) that open and close in one direction are provided at both ends of the damping channels (10). The inner cylinder (1) has openings on the cylindrical sides at both ends, which serve as openings for the magnetorheological fluid return channel (5). There is a gap between the inner cylinder (1) and the outer cylinder (2), which serves as the magnetorheological fluid return channel (5). The return channel (5) is connected to the upper and lower openings of the inner cylinder. The inner cylinder (1) is provided with a floating piston (16) or an air bladder (17) at the end away from the piston assembly (3). The opening of the magnetorheological fluid return channel (5) on the lower wall of the inner cylinder is located above the floating piston (16) or the air bladder (17). The inner cylinder (1) above the floating piston (16) or the air bladder (17) is filled with magnetorheological fluid. A compensation chamber is formed below the floating piston (16) or the air bladder (17), and the compensation chamber is filled with high-pressure inert gas.

2. The long-stroke twin-cylinder magnetorheological vibration damper according to claim 1, characterized in that, The piston assembly (3) includes an asymmetric piston body (8) and a piston rod (4) fixedly connected to the piston body (8). One end of the piston body (8) is fixedly connected to the piston rod (4), and the top of the inner cylinder (1) has an opening that allows the piston rod (4) to move freely.

3. The large-stroke twin-cylinder magnetorheological vibration damper according to claim 2, characterized in that, The piston body (8) is provided with an elastic reset guide mechanism (12) at the two one-way valve plates (11) in a static state to close the valve plates and restrict the rotation of the one-way valve plates (11), and the elastic reset guide mechanism (12) at the two one-way valve plates (11) has a valve plate opening and closing space that allows the one-way valve plates (11) to open and close.

4. The long-stroke twin-cylinder magnetorheological vibration damper according to claim 3, characterized in that, The damping channels (10) are evenly distributed around the piston rod (4).

5. The large-stroke twin-cylinder magnetorheological vibration damper according to claim 3, characterized in that, The damping channel (10) and the magnetorheological fluid return channel (5) are both filled with magnetorheological fluid, and the magnetorheological fluid circulates through the damping channel (10) inside the piston and the return channel (5) between the two cylinders.

6. The large-stroke twin-cylinder magnetorheological vibration damper according to claim 2, characterized in that, The other end of the piston rod (4) extends out of the inner cylinder (1) of the shock absorber, and a piston rod sealing assembly is installed at the upper opening of the inner cylinder (1).

7. The long-stroke twin-cylinder magnetorheological vibration damper according to claim 1, characterized in that, The outer wall of the inner cylinder (1) is provided with several coil mounting slots (13), and a cylindrical coil (18) is provided in the coil mounting slot (13). The cylindrical coil (18) is connected to an external controller through a control line. The control line is led out through the outer cylinder (2) and connected to an external power source.

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