CN111043223B

CN111043223B - Telescopic shear mode magneto-rheological shock absorber

Info

Publication number: CN111043223B
Application number: CN202010012381.0A
Authority: CN
Inventors: 姚嘉凌; 唐郑
Original assignee: Nanjing Forestry University
Current assignee: Nanjing Forestry University
Priority date: 2020-01-07
Filing date: 2020-01-07
Publication date: 2022-03-25
Anticipated expiration: 2040-01-07
Also published as: CN111043223A

Abstract

The invention discloses a telescopic shear mode magnetorheological damper, which comprises an inner cylinder, an outer cylinder and a telescopic cylinder positioned between the inner cylinder and the outer cylinder, wherein working gaps are respectively reserved between the telescopic cylinder and the inner cylinder as well as between the telescopic cylinder and the outer cylinder, magnetorheological fluid is filled in the working gaps, the upper end and the lower end of each working gap are respectively sealed, the telescopic cylinder can reciprocate along the working gaps, a coil is wound in a coil groove on the outer wall of the inner cylinder, a magnetic field is generated after the coil is electrified and acts on the magnetorheological fluid in the working gaps, a diaphragm is arranged in the lower end of the inner cylinder and divides the inner space into an upper chamber and a lower chamber, the upper chamber is communicated with the working gaps through communication holes, the inner part of the upper chamber is filled with the magnetorheological fluid, and gas with certain pressure is injected into the lower chamber. The invention generates damping force through a telescopic shearing mode, and the shock absorber has obvious low-speed large damping characteristic, and can provide considerable anti-roll damping force when a vehicle turns, thereby effectively inhibiting the roll of a vehicle body.

Description

Telescopic shear mode magneto-rheological shock absorber

Technical Field

The invention relates to a telescopic shear mode magnetorheological damper, and belongs to the field of automobile parts and vibration and noise reduction.

Background

The magnetic rheological liquid is a material whose rheological properties such as viscosity and plasticity are changed sharply under the action of external magnetic field, and its basic characteristics are that it can be changed from free flowing liquid into semisolid in millisecond time under the action of external magnetic field, and it presents controllable yield strength, and the change is reversible. By changing the current, the rheological property of the magnetorheological fluid can be effectively controlled, and the magnetorheological damper with continuously adjustable damping force can be designed according to the principle.

At present, most of common magnetorheological dampers are telescopic valve type magnetorheological dampers, pressure difference is generated between an upper cavity and a lower cavity through the up-and-down movement of a piston, so that magnetorheological fluid flows through a damping channel on the piston, and controllable damping force is generated by applying the flow mode of the magnetorheological fluid. The magnetorheological damper can provide small damping force at low speed. Considering that the roll frequency of a vehicle body is low when the vehicle runs in a steering mode, the telescopic valve type magnetorheological shock absorber cannot provide enough damping force to achieve effective roll control, and a rollover accident of the vehicle is caused in a serious situation. Although the patent application No. 201910623043.8 discloses a shear mode magnetorheological damper, which has a low-speed and large-damping characteristic, the structure of the magnetorheological damper still has the disadvantages of high manufacturing difficulty, high cost, and the need of an additional magnetorheological fluid compensation mechanism arranged outside.

Disclosure of Invention

The invention aims to solve the problems of the existing magnetorheological damper and provides a magnetorheological damper based on a telescopic shearing mode; the shock absorber generates damping force through a shear mode, has obvious low-speed large damping characteristics, and can provide considerable anti-roll damping force when a vehicle turns, so that the roll of the vehicle body is effectively inhibited, and the curve passing speed and the smoothness of the vehicle are improved.

In order to achieve the purpose, the invention adopts the technical scheme that: a flexible shear mode magneto-rheological shock absorber comprises an inner cylinder, an outer cylinder and a telescopic cylinder located between the inner cylinder and the outer cylinder, wherein working gaps are reserved between the telescopic cylinder and the inner cylinder and between the telescopic cylinder and the outer cylinder respectively, the working gaps are filled with magneto-rheological fluid, the upper ends of the working gaps are sealed through sealing rings, the lower ends of the working gaps are sealed through lower end covers, the telescopic cylinder can reciprocate in the magneto-rheological fluid along the working gaps, coils are wound on the outer wall of the inner cylinder, a magnetic field is generated after the coils are electrified and acts on the magneto-rheological fluid in the working gaps, the lower end of the inner cylinder is of a hollow structure, a diaphragm is arranged in an inner space at the lower end of the inner cylinder, the diaphragm divides the inner space into an upper chamber and a lower chamber, the upper chamber is communicated with the working gaps through communicating holes and is filled with the magneto-rheological fluid, and gas with a certain pressure is injected into the lower chamber.

Furthermore, the upper part or the lower part or the upper part and the lower part of the sealing ring are provided with guide rings, and the guide rings are arranged on the outer wall of the inner cylinder and the inner wall of the outer cylinder in an embedded mode.

Furthermore, the top of the telescopic cylinder is provided with an upper hanging ring used for being connected with a vehicle body.

Furthermore, the outside of a telescopic cylinder is provided with a dust cover, the upper end of the dust cover is fixedly sleeved on the upper end part of the telescopic cylinder or an upper hanging ring at the top end of the telescopic cylinder, the lower end of the dust cover is movably sleeved on the outer wall of the outer cylinder, an inward convex boss is arranged on the inner wall of the end part of the dust cover, which is in contact with the outer wall of the outer cylinder, and a felt is arranged in the boss to prevent dust from entering the inside of the shock absorber.

Furthermore, the outer wall around the top of outer cylinder is outwards convex, and it and the boss combined action on the dust cover inner wall to the vertical motion range of restriction telescopic cylinder prevents telescopic cylinder reciprocating motion and surpasss the sealing washer effect area and then leads to magnetorheological suspensions to leak and the separation from of telescopic cylinder and interior outer tube.

Furthermore, a partition board is arranged above the diaphragm, and a section of hollow space is arranged in the inner cylinder above the partition board and used for reducing the weight of the inner cylinder and further reducing the weight of the shock absorber.

Furthermore, the coil is wound in a coil groove, the coil groove is formed in the outer wall of the inner barrel, and a magnetism isolating ring used for guiding the distribution of the magnetic field is arranged in the coil groove on the outer side of the coil.

Furthermore, a coil lead channel is formed in the inner barrel and communicated with the coil groove for leading out a lead.

Further, an upper end cover and a buffer block are installed at the upper end of the inner barrel, and the lower end of the buffer block is embedded in the end portion of the inner barrel, and the upper end of the inner barrel penetrates out of the upper end cover.

Furthermore, the lower extreme demountable installation of inner tube, urceolus has the lower cover, the lower cover is used for sealed work clearance and lower cavity to seted up at the lower cover and be used for the gas nozzle of aerifing and be used for drawing forth the pin hole of wire.

In summary, when no external magnetic field is applied, the magnetorheological damper of the present invention has disordered particle distribution in the magnetorheological fluid, and at this time, the telescopic cylinder can continue to move as long as overcoming the viscous resistance, and the damping force provided by the telescopic cylinder is very limited. When an external magnetic field exists, the particles in the magnetorheological fluid are distributed in a chain-shaped manner along the direction of the magnetic field, the magnetorheological fluid develops from a fluid to a semi-solid, the shear yield strength is generated along with the development of the magnetic field strength, and the shear yield strength is increased along with the increase of the magnetic field strength. By controlling the current in the coil, the rheological property of the magnetorheological fluid in the working gap can be changed, so that corresponding shear stress is generated, and the control of the damping force generated by the magnetorheological damper is realized.

The magnetorheological damper is provided with a compensation mechanism, and ensures that the magnetorheological fluid chamber is filled with magnetorheological fluid all the time through the lower space of the inner cylinder in the process that the telescopic cylinder enters and exits the magnetorheological fluid chamber, and the specific process is as follows: when the magnetorheological damper is in a compression stroke, the volume of the telescopic cylinder entering the cavity is increased, and the pressure in the cavity is increased, so that redundant magnetorheological fluid flows into the upper cavity of the lower space of the inner cylinder under the action of the pressure; when the magnetorheological damper is in a stretching working stroke, the volume of the telescopic cylinder in the cavity is reduced, the pressure of the lower cavity in the lower space of the inner cylinder is greater than the pressure in the magnetorheological fluid cavity, and under the action of pressure, the magnetorheological fluid in the upper cavity of the inner cylinder flows into the cavity to compensate for the insufficient volume of the magnetorheological fluid caused by stretching motion.

Compared with the prior art, the invention has the following beneficial effects:

(1) the damping device realizes the generation of damping force by a shearing mode through a relatively simple structure, and has novel overall structure and easy realization.

(2) The damping force provided by the telescopic shear mode magnetorheological damper is mainly generated through the shear working mode of the magnetorheological fluid, and a large damping force can be obtained at a low speed.

(3) The telescopic shear mode magneto-rheological shock absorber can effectively reduce the vibration of the vehicle body when the vehicle runs straight, can effectively restrain the vehicle body from rolling due to the existence of low-speed and large-damping characteristics when the vehicle turns, provides better anti-rolling performance and smoothness for the vehicle, and improves the curve passing speed of the vehicle.

(4) Compared with the existing extension valve type magnetorheological damper, the extension shear mode magnetorheological damper has the advantages that the consumption of magnetorheological fluid is less, and the cost can be saved.

(5) The telescopic shear mode magnetorheological damper overcomes the defects that the coils of the existing magnetorheological damper are mostly arranged in the piston, the structural size has strict limitation on the number of turns of the coils, and the like. The upper part of the inner cylinder has larger size, and the double-coil structure is adopted, so that larger magnetic field intensity and magnetic field range can be generated, larger damping force can be provided, and the damping force adjusting range is enlarged.

(6) The magnet exciting coil of the magneto-rheological damper is arranged in the groove in the upper part of the inner cylinder, so that the space for arrangement is large, the high precision requirement is not required, and compared with the arrangement of the coil on the piston with a small volume, the processing difficulty is reduced, and the processing time and the cost are saved.

(7) The inner wall and the outer wall of the telescopic cylinder of the magneto-rheological shock absorber respectively generate shearing force between the inner cylinder and the outer cylinder, so that the working area of a shearing mode is increased, and larger damping force can be generated.

(8) The magneto-rheological damper and the magneto-rheological damper designed by the relevant principle can also be used in other relevant fields, and have wide application range.

In addition, compared with the patent with the application number of 201910623043.8 previously applied by the applicant, the innovation and the advantages of the invention are as follows:

(1) according to the magneto-rheological damper, the magneto-rheological fluid compensation mechanism is arranged in the inner space of the inner cylinder, so that the radial size of the damper is effectively reduced, and the mechanism interference possibly occurring in the installation of a real vehicle is reduced.

(2) The coil of the magneto-rheological shock absorber is directly close to the magneto-rheological fluid, so that the magnetic field intensity in a magneto-rheological fluid area can be enhanced, the problem of weakening of the magnetic field intensity caused by blocking of an air gap and a cylinder wall is avoided, and larger damping force can be obtained.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic view of the magnetic field distribution.

Labeled as: 1. the magnetorheological fluid damper comprises an upper lifting ring, 2 parts of a telescopic cylinder, 3 parts of a rubber buffer block, 4 parts of a guide ring, 5 parts of a sealing ring, 6 parts of an outer cylinder, 7 parts of an inner cylinder, 8 parts of a working gap, 9 parts of a coil, 10 parts of a dust cover, 11 parts of a felt, 12 parts of a felt seat, 13 parts of a bolt A, 14 parts of a lower lifting ring, 15 parts of an air nozzle, 16 parts of a lower end cover, 17 parts of a gasket, 18 parts of a communication hole, 19 parts of a diaphragm, 20 parts of a lower space, 21 parts of a partition board, 22 parts of a coil lead wire, 23 parts of a magnetism isolating ring, 24 parts of an upper end cover, 25 parts of a bolt B, 101 parts of a magnetic field and 102 parts of magnetorheological fluid.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1 to 2, the shear type magnetorheological damper of the present invention has a main structure comprising: the device comprises an upper lifting ring 1, a telescopic cylinder 2, a rubber buffer block 3, a guide ring 4, a sealing ring 5, an outer cylinder 6, an inner cylinder 7, a working gap 8, a coil 9, a dust cover 10, a felt 11, a felt seat 12, a lower lifting ring 14, an air nozzle 15, a lower end cover 16, a gasket 17, a diaphragm 19, a partition plate 21, a magnetism isolating ring 23, an upper end cover 24 and the like. Wherein: the inner cylinder, the outer cylinder and the telescopic cylinder 2 are sealed through a sealing ring 5 and a lower end cover 16 to form a closed cavity, and magnetorheological fluid is filled in the cavity. The rubber buffer block 3 is connected to the top of the inner barrel 7 through an upper end cover 24. The telescopic cylinder 2 reciprocates vertically between the inner cylinder and the outer cylinder. The outer side of the upper part of the inner cylinder 7 is provided with 2 annular coil grooves, and enameled wires are wound inside the coil grooves. Two sealing rings 5 are respectively arranged between the inner cylinder 7 and the telescopic cylinder 2 and between the outer cylinder 6 and the telescopic cylinder 2, so that magnetorheological fluid is prevented from flowing out of the chamber. The lower end cap 16 is secured to an annular boss in the lower part of the outer cylinder 6 by a bolt a13 with a spacer 17 disposed therebetween. The lower end cover 16 is provided with a small hole, and the small hole is provided with an air nozzle 15. The lower part of the inner cylinder 7 is provided with a communicating hole 18, the working gap 8 is connected with a lower space 20 of the inner cylinder through the communicating hole 18, the lower space 20 is divided into an upper chamber and a lower chamber by a diaphragm 19, the upper chamber is connected with the working gap 8, magnetorheological fluid is filled in the upper chamber, gas with certain pressure is injected into the lower chamber through an air nozzle 15, when the magnetorheological damper is in a compression stroke, the volume of the telescopic cylinder entering the chambers is increased, the pressure in the chambers is increased, and redundant magnetorheological fluid flows into the lower space of the inner cylinder under the action of the pressure; when the magnetorheological damper is in a stretching working stroke, the volume of the telescopic cylinder in the cavity is reduced, the pressure of the lower cavity in the lower space of the inner cylinder is greater than the pressure in the magnetorheological fluid cavity, and under the action of pressure, the magnetorheological fluid in the lower space of the inner cylinder flows into the cavity to compensate for the insufficient volume of the magnetorheological fluid caused by stretching movement.

The working principle of the extension shear mode magneto-rheological damper is as follows: the upper suspension ring 1 of the magneto-rheological shock absorber is connected with a vehicle body, and the lower suspension ring 14 is connected with a vehicle frame. When the vehicle runs, the magnetorheological damper makes stretching and compressing movement along with the relative movement of the upper connecting part and the lower connecting part, the telescopic cylinder 2 makes vertical reciprocating movement up and down, and a working gap is reserved between the inner cylinder and the outer cylinder and the telescopic cylinder 2. Due to the existence of the space 20 at the lower part of the inner cylinder, the magnetorheological fluid chamber can be ensured to be filled with the magnetorheological fluid all the time. The shearing stress generated between the inner wall and the outer wall of the telescopic cylinder 2 and between the inner cylinder 7 and the outer cylinder 6 changes along with the magnetic field intensity, the magnetic field intensity is influenced by the current in the coil 9, and the continuous control of the damping force generated by the shock absorber can be realized by controlling the size of the electrified current in the coil 9. The magneto-rheological shock absorber designed by the invention mainly depends on the shear mode of the magneto-rheological fluid to generate damping force, the damping force model of the shear mode is related to the hydrodynamic viscosity and the yield strength of the magneto-rheological fluid, and the hydrodynamic viscosity can be ignored compared with the shear yield stress of the magneto-rheological shock absorber, so that the magnitude of the damping force has no great relation with the relative movement speed, and when the speed is zero, a certain exciting current is applied, and a sufficient shear area is ensured, and a great damping force can be generated. The shear mode magnetorheological damper designed by the invention has the characteristics of low speed and large damping, and can obtain better anti-roll effect compared with a common valve type magnetorheological damper when a vehicle runs in a steering mode.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the scope of the present invention in any way, and all technical solutions obtained by using equivalent substitution methods fall within the scope of the present invention.

The parts not involved in the present invention are the same as or can be implemented using the prior art.

Claims

1. A magneto-rheological damper in a telescopic shearing mode comprises an inner cylinder, an outer cylinder and a telescopic cylinder positioned between the inner cylinder and the outer cylinder, it is characterized in that working gaps are respectively reserved among the telescopic cylinder, the inner cylinder and the outer cylinder, magnetorheological fluid is filled in the working gaps, the upper end of the working gap is sealed by a sealing ring, the lower end of the working gap is sealed by a lower end cover, the telescopic cylinder can reciprocate in the magnetorheological fluid along the working gap, the outer wall of the inner cylinder is wound with a coil, the coil generates a magnetic field after being electrified, the magnetic field acts on the magnetorheological fluid in the working gap, the inner part of the lower end of the inner cylinder is of a hollow structure, a diaphragm is arranged in the inner space at the lower end of the diaphragm, the diaphragm divides the inner space into an upper chamber and a lower chamber, the upper chamber is communicated with the working gap through a communicating hole, the inner part of the upper chamber is filled with magnetorheological fluid, and gas with certain pressure intensity is injected into the lower chamber; guide rings are arranged above or below the sealing ring or above and below the sealing ring and are arranged on the outer wall of the inner cylinder and the inner wall of the outer cylinder in an embedded mode; a dust cover is arranged outside the telescopic cylinder, the upper end of the dust cover is fixedly sleeved on the upper end part of the telescopic cylinder or an upper hanging ring at the top end of the telescopic cylinder, the lower end of the dust cover is movably sleeved on the outer wall of the outer cylinder, an inward-protruding boss is arranged on the inner wall of the end part of the dust cover, which is in contact with the outer wall of the outer cylinder, and a felt is arranged in the boss to prevent dust from entering the interior of the shock absorber; the outer wall of the periphery of the top end of the outer cylinder protrudes outwards and cooperates with the boss on the inner wall of the dust cover, so that the vertical movement range of the telescopic cylinder is limited, and the magnetorheological fluid is prevented from leaking and being separated from the inner cylinder and the outer cylinder due to the fact that the telescopic cylinder moves back and forth beyond the action area of the sealing ring; an upper end cover and a buffer block are installed at the upper end of the inner barrel, and the lower end of the buffer block is embedded in the end part and the upper end of the inner barrel and penetrates out of the upper end cover.

2. The telescopic shear mode magnetorheological damper of claim 1, wherein an upper suspension ring for connection to a vehicle body is provided at the top of the telescopic cylinder.

3. The telescopic shear mode magnetorheological damper of claim 1, wherein a partition is arranged above the diaphragm, and a hollow space is formed inside the inner cylinder above the partition for reducing the weight of the inner cylinder and further reducing the weight of the damper.

4. The telescopic shear mode magnetorheological damper of claim 1, wherein the coil is wound in a coil groove, the coil groove is formed in the outer wall of the inner cylinder, and a magnetism isolating ring for guiding the distribution of the magnetic field is arranged in the coil groove outside the coil.

5. The telescopic shear mode magnetorheological damper according to claim 1, wherein a coil lead channel is formed in the inner cylinder and communicated with the coil groove for leading out a lead.

6. The telescopic shear mode magnetorheological damper according to claim 1, wherein the lower end covers are detachably mounted at the lower ends of the inner cylinder and the outer cylinder, the lower end covers are used for sealing the working gap and the lower chamber, and the lower end covers are provided with air nozzles for inflating and lead holes for leading out lead wires.