Magnetorheological damper

Abstract

The utility model provides a magnetorheological damper which comprises a piston cylinder with an inner layer and an outer layer, an outer flow channel is formed between an inner cylinder body and an outer cylinder body, a piston is arranged in the inner cylinder body, inner cavities on the two sides of the piston are communicated through the outer flow channel, valve bodies are arranged at the two ends of the inner cylinder body, excitation coils are wound in the valve bodies through coil hubs, and magnetorheological fluid working gaps are formed in the valve bodies. The working gap is communicated with the inner cavity and the outer flow channel, and a heat conduction pipe surrounds the outer side of the valve body. During working, the rheological property of the magnetorheological fluid flowing through the working gap is regulated and controlled through the magnitude of current of the excitation coil. The magnetorheological fluid working gap of the magnetorheological damper is constructed based on the valve body with the fixed position, it is guaranteed that the coil does not move along with the piston, and the problem that in a traditional structure, due to coil movement, a wire is abraded is solved; in addition, the heat conduction pipe is matched for heat dissipation, the heat dissipation effect of the magnetorheological fluid near the magnet exciting coil is enhanced, and it is guaranteed that the performance of the damper is not affected by the temperature when the damper works for a long time.

Description

Technical Field

[0001] This utility model belongs to the field of damper technology, specifically relating to a magnetorheological damper. Background Technology

[0002] Dampers are a crucial component of automotive suspensions. Common dampers include magnetorheological dampers and CDC hydraulic dampers. Among them, magnetorheological dampers offer advantages such as fast response, good control, and strong adaptability, making them more promising for application. The working principle of magnetorheological dampers is based on the magnetorheological effect, specifically the change in the rheological properties of a magnetorheological fluid under the influence of an external magnetic field. In the absence of a magnetic field, it behaves as a Newtonian fluid; however, under a strong magnetic field, it behaves as a viscoplastic material with a certain shear yield stress. This change allows magnetorheological dampers to quickly adjust the damping force to adapt to different driving conditions and road surfaces.

[0003] In most mainstream magnetorheological damper products, the excitation coil is typically mounted on the piston. Due to the reciprocating oscillating motion of the piston during operation, the excitation coil wires wear faster, reducing its lifespan. Furthermore, the piston generates significant frictional heat between the fluid and the internal cavity, and between the piston and the internal cavity, during its reciprocating motion. Temperature has a substantial impact on the viscosity of the magnetorheological fluid; at high temperatures, the rheological effect of the fluid decreases, making the damping force uncontrollable and reducing the performance of the magnetorheological damper. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a magnetorheological damper to reduce the impact of piston motion on the excitation coil.

[0005] This utility model achieves the above-mentioned technical objectives through the following technical means.

[0006] A magnetorheological damper, comprising:

[0007] The inner cylinder has a piston inside and is filled with magnetorheological fluid.

[0008] At least one valve body is fixed to the end of the inner cylinder and connected to the inner cavity and the outer flow channel. The valve body is equipped with an excitation coil to regulate the rheological properties of the magnetorheological fluid flowing through it.

[0009] The outer flow channel, located on the outside of the inner cylinder, is used to connect the inner cylinder cavity on both sides of the piston.

[0010] Furthermore, the valve body includes:

[0011] The coil hub is a ring structure with an excitation coil wound on it;

[0012] The protective shell is fitted onto the outside of the coil hub and connects to the outer cylinder and the inner cylinder respectively;

[0013] Both the coil hub and the protective shell are made of magnetically conductive material. Gaps are left between the two end faces of the coil hub and the protective shell, and these gaps serve as the working gaps for the magnetorheological fluid.

[0014] Furthermore, an outer cylinder is fitted around the outer side of the inner cylinder, and the gap between the outer cylinder and the inner cylinder forms the outer flow channel.

[0015] Furthermore, the valve body is surrounded by several heat-conducting pipes, one end of which extends into the outer flow channel, and the other end extends out of the outer cylinder.

[0016] Furthermore, the valve body is provided in two parts, with the two ends of the inner cylinder body being fixedly connected to the outer cylinder body through the valve body.

[0017] Furthermore, a piston rod is connected to the piston, with both ends of the piston rod passing through the ends of the outer cylinder body, and a sliding seal is provided between the piston rod and the outer cylinder body;

[0018] The piston rod passes through the central axis of the coil hub and the protective shell, with a flow gap between the protective shell and the piston rod for the magnetorheological fluid to flow through the working gap.

[0019] Furthermore, the damper has connecting parts at both ends, one of which is connected to the piston rod, and the other of which is connected to the outer cylinder body through a bracket.

[0020] Furthermore, the working gap thickness is 1 mm.

[0021] Furthermore, the connecting part is a lifting lug;

[0022] The bracket is a sleeve-shaped structure, with one open end connected to the end of the outer cylinder and the sealed end provided with the lifting lug.

[0023] Furthermore, a conduit is provided between the protective shell and the outer cylinder.

[0024] The beneficial effects of this utility model are as follows:

[0025] (1) This utility model provides a magnetorheological damper, wherein the magnetorheological fluid working gap of the magnetorheological damper is constructed based on the valve body with a fixed position, ensuring that the coil does not move with the piston, thus avoiding the problem of wire wear caused by coil movement in the traditional structure.

[0026] (2) In this utility model, a heat pipe heat dissipation structure is designed around the upper and lower valve bodies to enhance the heat dissipation effect of the magnetorheological fluid near the excitation coil and ensure that the performance of the damper is not affected by temperature when it works for a long time.

[0027] (3) In this embodiment, a piston rod structure with two output rods is specifically adopted to enhance the guiding performance of the damper. At the same time, the volume changes of the upper and lower cavities are the same, avoiding the traditional accumulator structure and simplifying the structure of the magnetorheological damper. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the magnetorheological damper according to an embodiment of this application;

[0029] Figure 2 This is a structural diagram of the valve body in an embodiment of this application;

[0030] Figure 3 This is a perspective view of the coil hub in an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the working state of an embodiment of this application.

[0032] Figure label:

[0033] 11-Outer cylinder block; 12-Inner cylinder block; 13-Bracket; 14-Heat pipe;

[0034] 21-Piston rod; 22-Piston; 31-Upper connecting part; 32-Lower connecting part;

[0035] 4-Valve body; 41-Coil hub; 42-Excitation coil; 43-Sheath;

[0036] 44-Conduit; 45-Bolt; 46-Current clearance; 47-Working clearance. Detailed Implementation

[0037] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein similar or identical reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0038] like Figure 1 The magnetorheological damper shown includes a piston cylinder, a piston 22, and a valve body 4. The piston cylinder has a double-layered structure, comprising an outer cylinder body 11 and an inner cylinder body 12, with the inner cylinder body 12 fitted inside the outer cylinder body 11. The piston 22 is disposed within the inner cylinder body 12 and slides within it, allowing it to move up and down along the inner cylinder body 12. The inner cavity of the inner cylinder body 12 is filled with magnetorheological fluid, and the inner cavity is divided into an "upper inner cavity" and a "lower inner cavity" by the piston 22.

[0039] A gap is left between the side walls of the inner cylinder 12 and the outer cylinder 11, forming a channel for the flow of magnetorheological fluid, denoted as the "outer flow channel". The upper and lower ends of the inner cylinder 12 are connected to the outer cylinder 11 through valve bodies 4, respectively. The valve body 4 has a channel for magnetorheological fluid to connect the inner cavity and the outer flow channel. Furthermore, the upper inner cavity and the lower inner cavity are connected through the upper valve body 4, the outer flow channel, and the lower valve body 4.

[0040] In addition to the above embodiments, only one valve body 4 can be provided; for example, only the upper valve body 4 is retained, and the lower inner cylinder 12 and the outer cylinder 11 are replaced by conventional methods such as bolts and welding, and a channel is left at the connection to connect the lower inner cavity and the outer flow channel.

[0041] like Figure 1 As shown, the damper has two connecting parts for connecting to external devices: an upper connecting part 31 and a lower connecting part 32. The upper connecting part 31 is connected to the piston 22 via a piston rod 21, and the lower connecting part 32 is connected to the outer cylinder 11 via a bracket 13. In this embodiment, both the upper connecting part 31 and the lower connecting part 32 are lifting lugs. The piston 22 is fitted onto the middle of the piston rod 21, with both ends of the piston rod 21 extending out of the piston cylinder via the outer cylinder 11. The upper end of the piston rod 21 is fixedly connected to the upper connecting part 31. To prevent leakage of the magnetorheological fluid, a sliding seal is provided between the piston rod 21 and the outer cylinder 11.

[0042] In this embodiment, the support 13 is a sleeve-shaped structure, with an opening at the upper end and fixed to the end of the outer cylinder 11, and a lifting lug at the lower end. The sleeve-shaped support 13 can protect the lower piston rod and prevent secondary leakage of the magnetorheological fluid downwards.

[0043] In addition to the embodiments shown above, when an accumulator is connected to the inner cavity, the piston rod 21 may only have the upper part of the piston 22 shown in the figure; or it may be configured such that only the upper end protrudes from the piston cylinder, while the lower end (provided that the stroke of the piston 22 is avoided) remains completely in the lower inner cavity.

[0044] like Figure 2 As shown, the valve body 4 includes a coil hub 41 (structure as shown). Figure 3As shown, the coil hub 41 has a coil groove for winding the excitation coil 42. A protective shell 43 is provided on the outside of the coil hub 41, and the protective shell 43 and the coil hub 41 are fixedly connected to the end of the outer cylinder 11 by four bolts 45. The protective shell 43 is connected and fixed to the end of the inner cylinder 12. A conduit 44 is provided between the protective shell 43 and the outer cylinder 11 for connecting the excitation coil 42 to external wires. The coil hub 41 and the protective shell 43 are annular structures, and both have through holes along their central axis for the piston rod 21 to pass through; a flow gap 46 is provided between the protective shell 43 and the piston rod 21 for the magnetorheological fluid to flow into or out of the valve body 4. Both the coil hub 41 and the protective shell 43 are made of magnetically conductive material. Inside the valve body 4, gaps are left between the upper and lower end faces of the coil hub 41 and the inner end faces of the protective shells 43 on both sides, serving as working gaps 47 for the magnetorheological fluid. The rheological characteristics of the magnetorheological fluid flowing through the working gap 47 are adjusted by controlling the magnitude of the current in the excitation coil 42. In this embodiment, the thickness of the working gap 47 is 1 mm.

[0045] To promote heat dissipation and protect the excitation coil 42 from the temperature rise of the magnetorheological fluid, several heat-conducting pipes 14 are evenly distributed at the end of the outer cylinder 11. One end of the heat-conducting pipe 14 is exposed to the outside air of the piston cylinder, and the other end extends into the outer flow channel between the inner and outer cylinders and surrounds the valve body 4.

[0046] like Figure 4 As shown in the diagram, the blue portion represents the magnetorheological fluid. When the upper connecting part 31 pulls the piston 22 upward, the piston 22 pushes the magnetorheological fluid in the upper inner cavity through the upper valve body 4 to the outer flow channel. The magnetorheological fluid in the outer flow channel then flows into the lower inner cavity through the lower valve body 4 under the action of pressure difference. During this process, the damping of the magnetorheological fluid is adjusted by controlling the current of the excitation coil 42 inside the valve body 4. Wherein:

[0047] 1) When a smaller damping force is required, reduce the current of the excitation coil 42 or turn it off. At this time, the magnetic field on the valve body 4 is weak or no magnetic field is generated. The magnetorheological fluid mainly exhibits a liquid state. When it flows through the working gap 47, it is less obstructed and outputs a lower damping force.

[0048] 2) When a large damping force is required, a large current is passed through the excitation coil 42. At this time, the valve body 4 generates a strong magnetic field. The magnetorheological fluid flowing through the working gap 47 mainly exhibits a solid-like behavior, thus increasing its viscosity. When passing through the working gap 47, it is strongly hindered and outputs a large damping force.

[0049] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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. Therefore, they should not be construed as limitations on this utility model.

[0050] This utility model is not limited to the above-described embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essential content of this utility model shall fall within the protection scope of this utility model.

Claims

1. A magnetorheological damper, characterized in that: include: The inner cylinder (12) has a piston (22) in its inner cavity and is filled with magnetorheological fluid; At least one valve body (4) is fixed at the end of the inner cylinder (12) and connected to the inner cavity and the outer flow channel. An excitation coil (42) is provided in the valve body (4) to regulate the rheological properties of the magnetorheological fluid flowing through it. The outer flow channel is located outside the inner cylinder (12) and is used to connect the inner cavity of the inner cylinder (12) on both sides of the piston (22).

2. The magnetorheological damper according to claim 1, characterized in that: The valve body (4) includes: The coil hub (41) is a ring structure with an excitation coil (42) wound on it. The protective shell (43) is fitted on the outside of the coil hub (41) and is connected to the outer cylinder (11) and the inner cylinder (12) respectively. Both the coil hub (41) and the protective shell (43) are made of magnetically conductive material. There are gaps between the two end faces of the coil hub (41) and the protective shell (43), which serve as the working gap (47) of the magnetorheological fluid.

3. The magnetorheological damper according to claim 2, characterized in that: An outer cylinder (11) is fitted around the inner cylinder (12), and the gap between the outer cylinder (11) and the inner cylinder (12) forms the outer flow channel.

4. The magnetorheological damper according to claim 3, characterized in that: The valve body (4) is surrounded by several heat-conducting pipes (14), one end of which extends into the outer flow channel and the other end extends out through the outer cylinder (11).

5. The magnetorheological damper according to claim 3, characterized in that: The valve body (4) is provided in two parts, and the two ends of the inner cylinder (12) are respectively fixedly connected to the outer cylinder (11) through the valve body (4).

6. The magnetorheological damper according to claim 3, characterized in that: A piston rod (21) is connected to the piston (22). Both ends of the piston rod (21) pass through the ends of the outer cylinder (11), and a sliding seal is provided between the piston rod (21) and the outer cylinder (11). The piston rod (21) passes through the central axis of the coil hub (41) and the protective shell (43), wherein a flow gap (46) is left between the protective shell (43) and the piston rod (21) for the magnetorheological fluid to flow through the working gap (47).

7. The magnetorheological damper according to claim 6, characterized in that: The damper has connecting parts at both ends. One end of the connecting part is connected to the piston rod (21), and the other end of the connecting part is connected to the outer cylinder (11) through the bracket (13).

8. The magnetorheological damper according to claim 2, characterized in that: The working gap (47) has a thickness of 1 mm.

9. The magnetorheological damper according to claim 7, characterized in that: The connecting part is a lifting lug; The bracket (13) is a sleeve-shaped structure, with one open end connected to the end of the outer cylinder (11) and the sealed end provided with the lifting lug.

10. The magnetorheological damper according to claim 3, characterized in that: A conduit (44) is provided between the protective shell (43) and the outer cylinder (11).

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