Rigidity-variable decoupling type magnetorheological damper

Abstract

In order to solve the high-frequency hardening problem of a magnetorheological damper in the prior art, the variable-stiffness decoupling type magnetorheological damper comprises an end cover, screws, a cylinder cover, a cylinder body, a piston rod, a piston assembly, an inner coil and an outer coil, the end cover, the cylinder cover and the cylinder body are fixed through the screws, the cylinder cover and the cylinder body form a closed cavity, and the cavity is filled with magnetorheological fluid; one end of the piston rod sequentially penetrates through the cylinder cover, the piston assembly and the bottom of the cylinder body, the inner side of the piston assembly is fixedly connected with the outer side of the piston rod, a gap is reserved between the outer side of the piston assembly and the inner wall of the cylinder body to form a damping channel, and the inner coil and the outer coil are wound on the piston assembly. According to the variable-stiffness decoupling type magnetorheological damper, by adding the magnetorheological elastomer, variable-stiffness connection of the piston assembly and the piston rod of the magnetorheological damper is achieved, high-frequency dynamic decoupling of the magnetorheological damper is achieved, and the high-frequency application range of the magnetorheological damper is expanded. The invention belongs to the field of satellite platform vibration control.

Description

Technical Field

[0001] The present invention relates to a damper, in particular to a variable stiffness decoupling type magnetorheological damper, and belongs to the technical field of satellite platform vibration control. Background Art

[0002] A magnetorheological damper is a device that provides resistance to motion and dissipates motion energy. As an ideal semi-active actuator device, the magnetorheological damper has broad application prospects in the field of satellite platform vibration control. The magnetorheological damper is a device developed based on the magnetorheological effect, with characteristics such as simple structure, fast response, and controllable damping force, and has relatively mature application cases in medium and low frequency vibration control scenarios such as vehicles and bridges. However, in the high-frequency excitation environment in the satellite field, the magnetorheological damper will exhibit a dynamic characteristic hardening phenomenon, the dynamic stiffness of the magnetorheological damper will increase, thereby affecting the vibration control effect, and severely restricting the application range of the magnetorheological damper.

[0003] Existing solutions, such as the high-frequency decoupling type piston magnetorheological damper disclosed in publication number CN 101725660 A, and the high-energy-consuming self-decoupling type magnetorheological damper disclosed in publication number CN 101446117, separate the piston and the piston rod of the magnetorheological damper and connect them through a spring, which can solve the high-frequency hardening problem of the magnetorheological damper to a certain extent. However, the stiffness of the spring is uncontrollable, and it is impossible to accurately regulate the connection stiffness between the piston and the piston rod of the magnetorheological damper, and it is difficult to meet the stiffness regulation requirements under different working conditions. CN 104315071 A discloses a new type of intelligent shock absorber integrating multi-layer magnetorheological elastomers and magnetorheological dampers, CN 107269759 A discloses a variable stiffness vibration isolator for electronic equipment vibration isolation, publication number CN 104315073 A discloses a variable stiffness and variable damping shock absorber based on a magnetorheological damper and a spring, and publication number CN 107387651 A discloses a variable stiffness magnetorheological damper and its control method, providing variable stiffness devices related to magnetorheological dampers. However, the piston and the piston rod of the magnetorheological damper are rigidly connected, and it is difficult to achieve dynamic decoupling of the magnetorheological damper under high-frequency vibration.

[0004] Therefore, in order to solve the above-mentioned high-frequency hardening problem of the magnetorheological damper and meet the requirements of the stiffness and damping characteristics of the magnetorheological damper under different working conditions, it is necessary to propose a decoupling type magnetorheological damper with adjustable stiffness. Summary of the Invention

[0005] The present invention aims to solve the problem of high-frequency hardening of magnetorheological dampers in the prior art and meet the requirements of different working conditions for the stiffness and damping characteristics of magnetorheological dampers. Therefore, a variable-stiffness decoupled magnetorheological damper is proposed, which greatly expands the applicability of magnetorheological dampers to high-frequency vibrations and broadens the application range of magnetorheological dampers.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows:

[0007] The present invention includes an end cap, screws, a cylinder head, a cylinder body, a piston rod, a piston assembly, an inner coil, and an outer coil. The end cap, cylinder head, and cylinder body are fixed by screws. The cylinder head and cylinder body form a sealed chamber filled with magnetorheological fluid. One end of the piston rod sequentially passes through the cylinder head, piston assembly, and the bottom of the cylinder body. The inner side of the piston assembly is fixedly connected to the outer side of the piston rod, and there is a gap between the outer side of the piston assembly and the inner wall of the cylinder body to form a damping channel. The inner coil and the outer coil are respectively wound on the piston assembly.

[0008] Further, the piston assembly includes a magnetorheological elastomer, an inner sleeve ring, a magnetic shielding ring, and an outer sleeve ring. The magnetorheological elastomer, inner sleeve ring, magnetic shielding ring, and outer sleeve ring are arranged in sequence from the inside to the outside. The inner coil is wound on the inner sleeve ring, and the outer coil is wound on the outer sleeve ring.

[0009] Further, the piston rod, inner sleeve ring, outer sleeve ring, and cylinder body are made of magnetic conductive materials, and the magnetic shielding ring is made of non-magnetic conductive materials.

[0010] Further, a first annular groove for winding the inner coil is provided at the inner side end of the inner sleeve ring.

[0011] Further, a second annular groove for winding the outer coil is provided at the outer side end of the outer sleeve ring.

[0012] Further, the magnetorheological elastomer, inner sleeve ring, magnetic shielding ring, and outer sleeve ring are adhesively fixed in sequence from the inside to the outside.

[0013] The beneficial effects of the present invention are as follows:

[0014] 1. The variable-stiffness decoupled magnetorheological damper of the present invention realizes variable-stiffness connection between the piston assembly and the piston rod of the magnetorheological damper by adding a magnetorheological elastomer, achieves high-frequency dynamic decoupling of the magnetorheological damper, and expands the high-frequency applicable range of the magnetorheological damper.

[0015] 2. The variable-stiffness decoupled magnetorheological damper of the present invention can adaptively adjust the connection stiffness and output damping of the magnetorheological damper according to different working conditions by adding a magnetorheological elastomer, and can greatly improve the vibration reduction and isolation performance of the magnetorheological damper.

[0016] 3. The present invention is respectively provided with an inner coil and an outer coil on the inner sleeve ring and the outer sleeve ring, and the output damping of the magnetorheological damper is changed by adjusting the magnitude of the current in the outer coil; the connection stiffness of the magnetorheological damper is changed by adjusting the magnitude of the current in the inner coil, so as to meet the vibration reduction and isolation requirements under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the overall structure of the present invention;

[0018] Figure 2 is Figure 1 a cross-sectional view of;

[0019] Figure 3 Schematic diagram of the magnetic circuit distribution of the magnetorheological damper in the embodiment of the present invention.

[0020] In the figure, 1 - end cap, 2 - screw, 3 - cylinder head, 4 - cylinder block, 5 - piston rod, 6 - piston assembly, 7 - magnetorheological elastomer, 8 - inner sleeve ring, 9 - inner coil, 10 - outer coil, 11 - magnetic flux barrier ring, 12 - outer sleeve ring, 13 - outer magnetic force line, 14 - inner magnetic force line. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] As Figure 1 and Figure 2 shown, a variable stiffness decoupled magnetorheological damper described in this embodiment includes an end cap 1, a screw 2, a cylinder head 3, a cylinder block 4, a piston rod 5, a piston assembly 6, an inner coil 9 and an outer coil 10. The end cap 1, the cylinder head 3 and the cylinder block 4 are fixed by the screw 2. The cylinder head 3 and the cylinder block 4 form a sealed chamber, and the chamber is filled with magnetorheological fluid. One end of the piston rod 5 sequentially passes through the cylinder head 3, the piston assembly 6 and the bottom of the cylinder block 4, and the inner side of the piston assembly 6 is fixedly connected to the outer side of the piston rod 5. There is a gap between the outer side of the piston assembly 6 and the inner wall of the cylinder block 4 to form a damping channel, and the inner coil 9 and the outer coil 10 are respectively wound on the piston assembly 6. The piston rod 5 is in clearance fit with the cylinder head 3 and the cylinder block 4 respectively, and sliding seals are achieved through sealing rings.

[0022] The piston assembly 6 includes a magnetorheological elastomer 7, an inner sleeve ring 8, a magnetic flux barrier ring 11 and an outer sleeve ring 12. The magnetorheological elastomer 7, the inner sleeve ring 8, the magnetic flux barrier ring 11 and the outer sleeve ring 12 are arranged in sequence from the inside to the outside. The inner coil 9 is wound on the inner sleeve ring 8, and the outer coil 10 is wound on the outer sleeve ring 12.

[0023] The magnetic flux barrier ring 11 is installed between the inner sleeve ring 8 and the outer sleeve ring 12 to prevent the magnetic fields generated by the inner coil 9 and the outer coil 10 from interfering with each other;

[0024] The magnetorheological elastomer 7 is installed between the piston rod 5 and the inner collar 8, and the variable stiffness connection between the piston assembly of the magnetorheological damper and the piston rod is realized through the magnetorheological elastomer 7, so as to achieve the high-frequency dynamic decoupling of the magnetorheological damper and expand the high-frequency application range of the magnetorheological damper;

[0025] By adjusting the magnitude of the current in the outer coil 10, the output damping of the magnetorheological damper is changed; by adjusting the magnitude of the current in the outer coil 9, the connection stiffness of the magnetorheological damper is changed;

[0026] Preferably, the piston rod 5, the inner collar 8, the outer collar 12 and the cylinder block 4 are made of magnetic conductive materials, and the magnetic resistance ring 11 is made of non-magnetic conductive materials.

[0027] Preferably, a first annular groove for winding the inner coil 9 is provided at the inner end of the inner collar 8; a second annular groove for winding the outer coil 10 is provided at the outer end of the outer collar 12.

[0028] Preferably, the magnetorheological elastomer 7, the inner collar 8, the magnetic resistance ring 11 and the outer collar 12 are fixedly connected together in sequence from inside to outside.

[0029] In this embodiment, after the inner coil 9 is energized, a circumferentially distributed magnetic field is generated, and the schematic diagram of the magnetic force lines is as shown in Figure 3 the inner magnetic force lines 14 shown; after the outer coil 10 is energized, a circumferentially distributed magnetic field is generated, and the schematic diagram of the magnetic force lines is as shown in Figure 3 the inner magnetic force lines 13 shown; in order to avoid the mutual interference of the magnetic fields generated by the inner coil 9 and the outer coil 10, a magnetic resistance ring 11 is provided in the piston assembly 6. The magnetic field generated by the inner coil 9 is mainly used to control the shear effect of the magnetorheological elastomer 7 to regulate the connection stiffness between the piston assembly 6 and the piston rod 5; the magnetic field generated by the outer coil 10 is mainly used to control the shear yield strength of the magnetorheological fluid in the damping channel to regulate the damping force of the magnetorheological damper.

[0030] The variable stiffness decoupling type magnetorheological damper is installed between the base and the load. The base is fixed to the end cover 1, and the load is fixed to the piston rod 5. During the working process, the vibration of the base drives the piston assembly 6 of the magnetorheological damper to slide relative to the cylinder block 4, and the magnetorheological fluid in the cylinder block 4 flows through the damping channel. When the outer coil 10 is not energized, the magnetorheological damper outputs a passive damping force, and the magnitude of the damping force is uncontrollable at this time; when the outer coil 10 is energized, the magnetorheological damper outputs a controllable damping force, and the magnitude of the damping force changes with the magnitude of the current. Under the condition of low-frequency and large-amplitude vibration, the magnitude of the current in the inner coil 9 is increased to improve the connection stiffness between the piston assembly 6 and the piston rod 5, facilitating the output of the damping force; under the condition of high-frequency and small-amplitude vibration, the magnitude of the current in the inner coil 9 is decreased to reduce the connection stiffness between the piston assembly 6 and the piston rod 5, facilitating the dynamic decoupling of the magnetorheological damper; under other working conditions, the currents in the inner coil 9 and the outer coil 10 can be dynamically adjusted according to the vibration control requirements to regulate the connection stiffness and damping output of the magnetorheological damper to meet the vibration reduction and isolation requirements under different working conditions.

[0031] The above is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to form an equivalent embodiment with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the technical solution content of the present invention and is based on the technical essence of the present invention, any simple modification, equivalent replacement, and improvement made to the above embodiment still fall within the protection scope of the technical solution of the present invention.

Claims

1. A variable stiffness decoupling magnetorheological damper, comprising an end cover (1), a screw (2), a cylinder cover (3), a cylinder body (4) and a piston rod (5), wherein the end cover (1), the cylinder cover (3) and the cylinder body (4) are fixed by means of the screw (2), the cylinder cover (3) and the cylinder body (4) form a closed chamber, and the chamber is filled with a magnetorheological fluid; the characteristics are as follows: The variable stiffness decoupling type magnetorheological damper further comprises a piston assembly (6), an inner coil (9) and an outer coil (10); one end of the piston rod (5) passes through the cylinder cover (3), the piston assembly (6) and the bottom of the cylinder body (4) in sequence; the inner side of the piston assembly (6) is fixedly connected to the outer side of the piston rod (5); a gap is left between the outer side of the piston assembly (6) and the inner wall of the cylinder body (4) to form a damping channel; the inner coil (9) and the outer coil (10) are respectively wound on the piston assembly (6); The piston assembly (6) comprises a magnetorheological elastomer (7), an inner ring (8), a magnetic resistance ring (11) and an outer ring (12); the magnetorheological elastomer (7), the inner ring (8), the magnetic resistance ring (11) and the outer ring (12) are arranged in sequence from the inside to the outside; the inner coil (9) is wound around the inner ring (8), and the outer coil (10) is wound around the outer ring (12).

2. The variable stiffness decoupled magnetorheological damper according to claim 1, characterized in that: The piston rod (5), the inner sleeve ring (8), the outer sleeve ring (12) and the cylinder body (4) are made of magnetic conductive materials, and the magnetic blocking ring (11) is made of non-magnetic conductive material.

3. The variable stiffness decoupled magnetorheological damper according to claim 1, characterized in that: The inner end of the inner sleeve ring (8) is provided with a first annular groove for winding the inner coil (9).

4. The variable stiffness decoupled magnetorheological damper according to claim 1, characterized in that: The outer end of the outer ring (12) is provided with a second annular groove for winding the outer coil (10).

5. The variable stiffness decoupled magnetorheological damper according to claim 1, characterized in that: The magnetorheological elastomer (7), the inner sleeve ring (8), the magnetic blocking ring (11) and the outer sleeve ring (12) are bonded and fixed together in sequence from the inside to the outside.

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