Piston assembly of magnetorheological damper

Abstract

The utility model relates to the field of machinery, and discloses a piston assembly of a magnetorheological damper, which is used for conveniently realizing asymmetric distribution of restoring force and compressing force by changing the structure of a valve core. The magneto-rheological damper piston assembly comprises at least one stepped hole formed in the middle of a valve element, the stepped holes are arranged in a unified mode that the upper portion is thick and the lower portion is thin and are communicated with open holes of an upper end cover and a lower end cover of a piston, and a steel ball with the diameter larger than that of a thin section is contained in the thick section. Each steel ball is fixed with the lower end of a matched spring, and the upper end of each spring is fixedly connected with the piston upper end cover, so that the piston assembly is in an asymmetric state that the compression damping force is smaller than the recovery damping force.

Description

TECHNICAL FIELD

[0001] The utility model relates to mechanical technical field especially relates to a magneto-rheological damper piston assembly. BACKGROUND

[0002] The magneto-rheological damper is a kind of intelligent damper of damping quick adjustable made by the flow effect of magnetic rheological fluid to magnetic field, and it has very good application prospect in the vibration control and motion control of active field such as vehicle, civil engineering, medical instrument, robot.

[0003] In the recovery process of shock absorber, recovery force is usually required to be greater than compression force, but the recovery force and damping force of existing magneto-rheological shock absorber during working process are often 1:1.Therefore, it is necessary to change the structure of valve core to realize that the recovery force of shock absorber is greater than compression force or meet the asymmetric demand that the recovery force is less than compression force in some occasions. UTILITY MODEL CONTENT

[0004] The utility model discloses a kind of magneto-rheological damper piston assemblies, to realize the asymmetric distribution of recovery force and compression force conveniently by changing the structure of valve core.

[0005] To achieve the above object, the magneto-rheological damper piston assembly disclosed by the utility model includes at least one stepped hole arranged in the middle of the valve core, each stepped hole adopts a uniform arrangement of thick upper and thin lower and is communicated with the openings of the upper and lower end covers of the piston, and a steel ball with a diameter greater than the diameter of the thin segment and less than the diameter of the thick segment is accommodated in the thick segment, each steel ball is fixed with the lower end of a matched spring, and the upper end of each spring is fixedly connected with the upper end cover of the piston, so that the piston assembly presents an asymmetric state of compression damping force less than recovery damping force.

[0006] Alternatively, the magneto-rheological damper piston assembly disclosed by the utility model includes at least one stepped hole arranged in the middle of the valve core, each stepped hole adopts a uniform arrangement of thick upper and thin lower and is communicated with the openings of the upper and lower end covers of the piston, and a steel ball with a diameter greater than the diameter of the thin segment and less than the diameter of the thick segment is accommodated in the thick segment, each steel ball is fixed with the lower end of a matched spring, and the upper end of each spring is fixedly connected with the upper end cover of the piston, so that the piston assembly presents an asymmetric state of compression damping force less than recovery damping force.

[0007] Alternatively, the magnetorheological damper piston assembly disclosed by the utility model includes at least one stepped hole arranged in the middle of the valve core, each stepped hole adopts a uniform arrangement mode of thick upper and thin lower and is communicated with the opening of the upper and lower end covers of the piston, and a spring sheet is arranged on the upper end cover of the piston, the edge and corner of the spring sheet covers the opening of the upper end cover of the piston communicated with each stepped hole, and a fixed point not affecting the flow guiding of each stepped hole in the compression state is arranged between the spring sheet and the upper end cover of the piston, so that the piston assembly is in an asymmetric state of the compression damping force being greater than the rebound damping force.

[0008] Alternatively, the magnetorheological damper piston assembly disclosed by the utility model includes at least one stepped hole arranged in the middle of the valve core, each stepped hole adopts a uniform arrangement mode of thick upper and thin lower and is communicated with the opening of the upper and lower end covers of the piston, and a spring sheet is arranged on the upper end cover of the piston, the edge and corner of the spring sheet covers the opening of the upper end cover of the piston communicated with each stepped hole, and a fixed point not affecting the flow guiding of each stepped hole in the compression state is arranged between the spring sheet and the upper end cover of the piston, so that the piston assembly is in an asymmetric state of the compression damping force being greater than the rebound damping force.

[0009] In summary, the utility model has the following beneficial effects: the rebound and compression damping force ratio can be conveniently and efficiently changed through the following three dimensions:

[0010] 1. The rebound and compression damping force ratio can be changed through the opening and closing of the stepped hole flow guiding function and the flow direction of the magnetorheological fluid in the stepped hole.

[0011] 2. Without changing the stepped damping hole, the opening degree of the stepped damping hole can be changed by changing the spring or spring sheet stiffness, so that the rebound and compression damping force ratio is changed.

[0012] 3. The rebound and compression damping force ratio can be changed by changing the number and distribution of the stepped damping hole, and the thickness and material (elastic modulus) of the spring sheet.

[0013] The utility model will be further described in detail below with reference to the drawings. DRAWINGS

[0014] The drawings constituting a part of the present application are used to provide further understanding of the utility model, and the schematic embodiments of the utility model and the description thereof are used to explain the utility model and do not constitute improper limitation on the utility model. In the drawings:

[0015] Figure 1 is the shock absorber structure schematic view disclosed by the utility model embodiment 1.

[0016] Figure 2 is the valve core structure schematic view of the piston assembly disclosed by the utility model embodiment 1.

[0017] Figure 3 is a schematic diagram of the shock absorber structure disclosed by the embodiment 2 of the present application.

[0018] Figure 4 is a schematic diagram of the valve core structure of the piston assembly disclosed by the embodiment 2 of the present application.

[0019]

Reference signs

[0020] 1, wire; 2, piston rod; 3, guide; 4, spring sheet; 5, valve core; 6, valve core sleeve; 7, floating piston; 8, cylinder (or referred to as "cylinder barrel"); 9, lower end cover of piston; 10, stepped damping hole; 11, coil; 12, spring; 13, upper end cover of piston; 14, threaded hole. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below with reference to the accompanying drawings, but the present application can be implemented in various different ways limited and covered by the claims.

[0022] Embodiment 1

[0023] The embodiment discloses a magnetorheological damper piston assembly, which is applied to a shock absorber. Figures 1 to 4 The components of the shock absorber mainly include: a wire 1, a piston rod 2, a guide 3, a spring sheet 4, a valve core 5, a valve core sleeve 6, a floating piston 7, a cylinder (or referred to as "cylinder barrel") 8, a lower end cover of piston 9, a stepped damping hole 10, a coil 11, a spring 12, an upper end cover of piston 13 and a threaded hole 14.

[0024] As shown in Figure 1 and Figure 2 , the embodiment mainly punches one or more stepped holes in the valve core, and if the restoring force is greater than the compression force, the stepped hole is thick at the upper end and thin at the lower end (or vice versa). Preferably, an inclined chamfer transition is used in the thick-thin transition section of the stepped hole.

[0025] At the thick hole end of the stepped hole, a spring is arranged inside, one end of the spring is abutted against the upper end cover of piston (taking the structure that the restoring force is greater than the damping force as an example), and one end of the spring is abutted against a steel ball, and the steel ball can be clamped between the spring and the thin hole.

[0026] When the shock absorber is compressed, the magnetorheological fluid not only flows from the lower end to the upper end through the damping hole between the valve core and the valve core sleeve, but also flows from the thin hole of the stepped damping hole, compresses the spring, and flows to the upper end of the piston assembly through the large hole. When the shock absorber is restored, the magnetorheological fluid flows into the large hole of the stepped damping hole, impacts the steel ball, and the steel ball is pressed against the thin hole. Because the diameter of the steel ball is greater than that of the small hole, the small hole is blocked, so that the flow of the magnetorheological fluid between the stepped damping holes is cut off. In this way, because of the intervention of the stepped damping hole, the compression damping force is smaller than the restoring damping force.

[0027] At the same time, the size of the damping force during compression can be adjusted by changing the stiffness of the spring in the stepped damping hole, the size and number of the holes can also be adjusted, and the difference in size between the damping force and the compression force can also be changed.

[0003] In addition, because the damping hole area increases during compression, the overall friction of the shock absorber is reduced when considering the friction of both compression and recovery processes.

[0029] In summary, the piston assembly of the disclosed magneto-rheological damper includes at least one stepped hole arranged in the valve core, each stepped hole adopts a uniform arrangement of thick upper and thin lower and is in communication with the openings of the upper and lower end covers of the piston, and a steel ball with a diameter larger than that of the thin segment and smaller than that of the thick segment is accommodated in the thick segment, each steel ball is fixed with the lower end of a matched spring, and the upper end of each spring is fixedly connected with the upper end cover of the piston, so that the piston assembly is in an asymmetric state with a smaller compression damping force than a recovery damping force.

[0030] Among them, a floating piston is arranged in the cylinder body with a gap between the piston assembly and the lower part of the piston assembly. Optionally, the coil arranged in the piston assembly is connected with external equipment through a through hole in the piston rod.

[0031] Embodiment 2

[0032] Referring to Figure 3 and Figure 4 , the embodiment as a whole is similar to embodiment 1, but a spring sheet is additionally arranged on the upper end cover of the piston, and the valve core is less provided with a spring and a steel ball. A hole is arranged on the spring sheet and coaxial with the threaded hole on the valve core. The corners of the spring sheet can cover the hole on the upper end of the piston upper end cover, and the spring sheet is fixed on the piston upper end cover in the axial direction through the piston rod, and is connected with the piston upper end cover through the small through hole on the spring sheet by screwing to prevent axial rotation.

[0033] The edge of the spring sheet can cover the hole on the upper surface of the piston upper end cover, when the shock absorber is compressed, the magneto-rheological fluid pushes open the spring sheet through the stepped damping hole, reducing the compression damping force, and when the shock absorber is recovered, the magneto-rheological fluid exerts pressure on the upper surface of the spring sheet, closing the stepped damping hole, thereby changing the compression and recovery damping forces.

[0034] Like embodiment 1, the stiffness of the spring sheet can be changed, such as changing the shape, material, thickness, etc. of the spring sheet, to change and adjust the size of the compression damping force and reduce the overall friction.

[0035] In summary, the magnetorheological damper piston assembly disclosed in the embodiment comprises at least one stepped hole arranged in the middle of the valve core, each of the stepped holes is arranged in a uniform manner of thick at the top and thin at the bottom and is communicated with the openings of the upper and lower end covers of the piston, and a spring sheet is arranged on the upper end cover of the piston, the edges and corners of the spring sheet cover the openings of the upper end cover of the piston communicated with each of the stepped holes, and a fixed point is arranged between the spring sheet and the upper end cover of the piston, which does not affect the flow guiding of each of the stepped holes in the compression state, so that the piston assembly is in an asymmetric state with the compression damping force being smaller than the recovery damping force.

[0036] Based on the technical inspiration of the above two embodiments, the following alternative schemes of embodiment 3 and embodiment 4 can be obtained.

[0037] Embodiment 3

[0038] The embodiment discloses a magnetorheological damper piston assembly, comprising at least one stepped hole arranged in the middle of the valve core, each of the stepped holes is arranged in a uniform manner of thick at the top and thin at the bottom and is communicated with the openings of the upper and lower end covers of the piston, and a steel ball with a diameter larger than that of the thin section and smaller than that of the thick section is arranged in the thick section, each of the steel balls is fixed with the upper end of a matched spring, and the lower end of each of the springs is fixedly connected with the lower end cover of the piston, so that the piston assembly is in an asymmetric state with the compression damping force being greater than the recovery damping force.

[0039] Embodiment 4

[0040] The embodiment discloses a magnetorheological damper piston assembly, comprising at least one stepped hole arranged in the middle of the valve core, each of the stepped holes is arranged in a uniform manner of thick at the top and thin at the bottom and is communicated with the openings of the upper and lower end covers of the piston, and a spring sheet is arranged on the lower end cover of the piston, the edges and corners of the spring sheet cover the openings of the lower end cover of the piston communicated with each of the stepped holes, and a fixed point is arranged between the spring sheet and the lower end cover of the piston, which does not affect the flow guiding of each of the stepped holes in the recovery state, so that the piston assembly is in an asymmetric state with the compression damping force being greater than the recovery damping force.

[0041] Further, the embodiment can also increase the adjustable range of the asymmetry between the compression damping force and the recovery damping force by combining embodiment 1 with embodiment 2 and combining embodiment 3 with embodiment 4.

[0042] In summary, the magnetorheological damper piston assembly disclosed in the embodiment has the following beneficial effects: the recovery and compression damping force ratio can be conveniently and efficiently changed in the following three dimensions:

[0043] 1. The recovery and compression damping force ratio can be changed by switching the flow guiding function of the stepped hole and the flow direction of the magnetorheological fluid in the stepped hole.

[0044] 2、In the premise of not changing the ladder damping hole, the opening degree of the ladder damping hole can be changed by changing the stiffness of the spring or the spring sheet, so that the restoring and compression damping force ratio is changed.

[0045] 3、The restoring and compression damping force ratio can be changed by changing the number and distribution of the ladder damping holes, and the thickness and material (elastic modulus) of the spring sheet.

[0046] The preferred embodiments of the present application are described above, and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A magnetorheological damper piston assembly, comprising: The valve core is provided with at least one stepped hole, each of the stepped holes is arranged in a uniform manner of thick upper part and thin lower part and communicated with the opening of the upper and lower end cover of the piston, and a steel ball with a diameter larger than that of the thin segment and smaller than that of the thick segment is arranged in the thick segment, the lower end of each of the steel balls is fixed with a matched spring, and the upper end of each of the springs is fixedly connected with the upper end cover of the piston, so that the piston assembly is in an asymmetric state with the compression damping force smaller than the recovery damping force.

2. The magnetorheological damper piston assembly of claim 1, wherein, A floating piston is arranged in the cylinder with a gap between the piston assembly and the cylinder.

3. The magnetorheological damper piston assembly of claim 1 or 2, wherein, The coil arranged in the piston assembly is connected with external equipment through the through hole in the piston rod by a wire.

4. A magnetorheological damper piston assembly, characterized by, The valve core is provided with at least one stepped hole, each of the stepped holes is arranged in a uniform manner of thin upper part and thick lower part and communicated with the opening of the upper and lower end cover of the piston, and a steel ball with a diameter larger than that of the thick segment and smaller than that of the thick segment is arranged in the thick segment, the upper end of each of the steel balls is fixed with a matched spring, and the lower end of each of the springs is fixedly connected with the lower end cover of the piston, so that the piston assembly is in an asymmetric state with the compression damping force larger than the recovery damping force.

5. The magnetorheological damper piston assembly of claim 4, wherein, A floating piston is arranged in the cylinder with a gap between the piston assembly and the cylinder.

6. The magnetorheological damper piston assembly of claim 4 or 5, wherein, The coil arranged in the piston assembly is connected with external equipment through the through hole in the piston rod by a wire.

7. A magnetorheological damper piston assembly, characterized by, The valve core is provided with at least one stepped hole, each of the stepped holes is arranged in a uniform manner of thick upper part and thin lower part and communicated with the opening of the upper and lower end cover of the piston, and a spring sheet is arranged on the upper end cover of the piston, the edges and corners of the spring sheet cover the opening of the upper end cover of the piston communicated with each of the stepped holes, and a fixed point is arranged between the spring sheet and the upper end cover of the piston without affecting the flow guiding of each of the stepped holes in the compression state, so that the piston assembly is in an asymmetric state with the compression damping force smaller than the recovery damping force.

8. A magnetorheological damper piston assembly, characterized by, The valve core is provided with at least one stepped hole, each of the stepped holes is arranged in a uniform manner of thin upper part and thick lower part and communicated with the opening of the upper and lower end cover of the piston, and a spring sheet is arranged on the lower end cover of the piston, the edges and corners of the spring sheet cover the opening of the lower end cover of the piston communicated with each of the stepped holes, and a fixed point is arranged between the spring sheet and the lower end cover of the piston without affecting the flow guiding of each of the stepped holes in the recovery state, so that the piston assembly is in an asymmetric state with the compression damping force larger than the recovery damping force.

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