CN111677808A

CN111677808A - Double-rod uncompensated air chamber symmetric self-powered electro-rheological fluid damper

Info

Publication number: CN111677808A
Application number: CN202010544456.XA
Authority: CN
Inventors: 金辉; 姚进
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2020-06-15
Filing date: 2020-06-15
Publication date: 2020-09-18

Abstract

The invention relates to a double-rod uncompensated air chamber symmetric self-powered current transformer damper, which mainly comprises a damping part and two groups of symmetrically arranged power supply parts. When the piston rod is vibrated by the outside, the compression spring plate moves along with the piston rod, two groups of piezoelectric ceramics are respectively extruded to generate induction voltage in the compression stroke and the recovery stroke, the induction voltage is connected to the inner electrode and the outer electrode through a lead to generate an electric field, the viscosity of the electrorheological fluid between the two groups of piezoelectric ceramics is increased, and differential pressure is formed between the damping cavities so as to reduce the vibration of the piston. The larger the vibration amplitude of the piston is, the higher the voltage generated by the piezoelectric ceramic is, and the larger the resistance generated by the electrorheological fluid is, so that the purpose of self-coupling vibration reduction of the system is achieved. The structure of the invention adopts a symmetrical structure and a symmetrical working mode of double output rods, and can bear load and reduce vibration on two sides; the air chamber compensation part is omitted, the reliability and the working stability of the device are improved, unnecessary devices are reduced, and strict mechanical sealing and inflation processes are not required.

Description

Double-rod uncompensated air chamber symmetric self-powered electro-rheological fluid damper

Technical Field

The invention relates to a novel electrorheological fluid damper, which is an intelligent damper with symmetrical structure and working mode, does not need an external power supply during working and can automatically couple and damp along with external vibration amplitude.

Background

Electrorheological fluids (ERF fluids) are smart materials, which are typically suspensions of micron (or nanometer) sized particles with high dielectric constants uniformly dispersed in an insulating, low dielectric constant, oil phase medium. When an external electric field is applied, the ERF fluid transitions from a fluid state to a solid-like state, with a sharp increase in apparent viscosity of several orders of magnitude and higher shear stresses. The process is reversible, controllable, rapid and low energy consuming. These excellent electromechanical coupling properties allow the ERF fluids to effectively address energy transfer and control problems in mechanical engineering. Zhao Xiaopeng et al in a patent of a self-coupling current transformation liquid damper without external power supply (ZL 02139476.8), designed with a piezoelectric ceramic power supply adaptive current transformation liquid damper, omitted the external power supply, but the whole damper only works in the process of downward compression, generates damping, and there is no variable damping in the return stroke. The volume change of the inner cavity of the damper caused by the piston rod is not considered in the damper, and the damper can hardly be realized in practical application. Liuwei et al in the patent "a novel piezoelectric ceramic and electrorheological fluids self-coupling damper" (CN 110195760A) has adopted the piezoelectric ceramic symmetrical arrangement, utilize spring and pressure spring board, realized that compression and two strokes of restoring can all extrude the piezoelectric ceramic to produce induced voltage, but this damper has adopted the air chamber to compensate the volume of piston rod motion, must accomplish under the effect of gas pressure, inflation pressure is very important, inflation pressure is too big to make the damper compress the damping force increase, inflation pressure is too little can not normally compensate the flow of current variant, make the damper show the merit characteristic take place the change, the damper of this structure requires more strict mechanical seal and inflation technology, produce gas leakage easily and make the damper unable to work normally. The similar electrorheological fluid damper is mostly of an asymmetric structure, the working mode is an asymmetric mode, and only one fixed side can bear load to reduce vibration; by adopting the gap or pore passage to circulate the electrorheological fluid, the electrorheological fluid particles are easy to settle and block small holes after a long time, and the performance of the damper is seriously influenced. The above dampers have respective drawbacks, which have limited their application.

Disclosure of Invention

The invention aims to provide a symmetrical self-powered electrorheological fluid damper with double-rod uncompensated air chambers, which aims at solving the problems that the single-side loaded load of the conventional electrorheological fluid damper is easy to precipitate after being used for a long time and the volume compensation structure is complicated, and provides a structure with symmetrical power supply and self-coupling vibration reduction. It has the characteristics of simple and symmetrical structure, direct stress, large vibration resistance amplitude, large stroke, reliable and stable work and the like. The damper adopts symmetrical arrangement, can all the pressurized work bidirectionally, utilize spring and pressure spring board for thereby it can all receive the extrusion and produce stable voltage to guarantee all piezoceramics in every stroke, and the attenuator can both provide variable damping force when tensile and compression stroke like this. The symmetrical structure enables two sides of the working process to be stressed conveniently, stably and reliably, and effectively solves the problem of electrorheological fluid particle deposition after long working time. The double-rod structure saves a compensation device, increases the working stroke of the damper and simultaneously has simple structure, easy assembly and reliable performance. Wherein the guide ring plays the dual functions of stabilizing the motion direction of the piston rod and assisting in fixing the piezoelectric ceramics.

Drawings

Fig. 1 is a front sectional view of a piezoelectric ceramic and electrorheological fluid self-coupling damper provided in the invention. The components and numbers in fig. 1 are:

1. the structure comprises a top cover 2, a compression spring plate 3, a spring 4, a bolt 5, a hexagon nut 6, a gasket 7, a piston 8, a lead 9, an outer cylinder 10, a connecting plate 11, piezoelectric ceramics 12, electrorheological fluid 13, an inner polar plate 14, an annular damping channel 15, an outer polar plate 16, a pore channel 17, a cylinder body 18, a cylinder cover 19, an O-shaped sealing ring 20, a guide ring 21, an outer cylinder cover 22 and a piston rod.

Detailed Description

The purpose of the invention is realized as follows: the structure of the present invention is shown in fig. 1. The energy supply part consists of a piston rod (22), a compression spring plate (2), a spring (3), a fixing plate (10), piezoelectric ceramics (11) and a lead (8); the damping part consists of an annular damping channel (14), an inner electrode plate (13), an outer electrode plate (15), a pore canal (16) and electrorheological fluid (12); the sealing structure is composed of a sealing part consisting of a cylinder body (17), a cylinder cover (18), an outer cylinder (9), an outer cylinder cover (21), a top cover (1), an O-shaped sealing ring (19), a bolt (4), a hexagon nut (5) and a gasket (6). Wherein the two groups of energy supply parts are symmetrically arranged relative to the damping part; a double-rod structure is used for replacing a common compensation air chamber and a common compensation valve; a guide ring (20) is arranged to ensure the stability of the movement of the piston rod; the inner and outer electrodes are respectively embedded on the inner and outer cylinders of the damper, a damping channel is formed between the inner and outer electrodes, and the pore channels are arranged on two sides of the stroke end of the piston, so that the electrorheological fluid is refluxed.

The piston rod (22) is permanently connected to the piston (7). The compression spring plate (2) is fixed on the piston rod (22), and one end of the compression spring plate (2) is connected with the spring (3). The piston rod (22) is connected with the external force application mechanism through the central holes of the outer cylinder cover (16) and the top cover (1). The top cover is connected with the damper outer cylinder through threads, and the effects of packaging and stabilizing the motion direction of the piston rod are achieved.

The springs (3) are divided into two groups and are respectively connected with the pressure spring plate (2) and the fixed plate (10), the fixed plates (10) with symmetrical two sides can only move towards the direction of the symmetrical center to extrude the piezoelectric ceramics, and the piezoelectric ceramics on one side of the pressure spring works. When the piston rod (22) moves, the piezoelectric ceramics (11) is pressed to generate voltage in any stroke.

The piezoelectric ceramic (11) is connected with the inner electrode plate (13) and the outer electrode plate (15) through a lead (8), an O-shaped sealing ring (19) is adopted between the piston rod (22) and the damping cavity, and the damper outer cylinder (9) and the cylinder body (17) are connected with the nut (5) through a bolt (4).

The working principle of the damper is as follows: when the piston rod (22) is driven to move by external force, the piston rod (22) moves together with the compression spring plate (2), and the spring (3) extrudes the piezoelectric ceramic (11) on the side to generate voltage. The same is true for the backhaul. The generated voltage is connected to the inner electrode plate (13) and the outer electrode plate (15) through the lead (8). The electrorheological fluid (12) between the inner and outer electrodes is affected by the electric field, the viscosity is increased, and the shear strength is increased. Under the thrust action of the piston (7), the electrorheological fluid (12) flows from the damping cavity to the space between the inner electrode (13) and the outer electrode (15) through the pore passage (16) and then flows back to the damping cavity through the pore passage on the other side of the piston. As the viscosity of the electrorheological fluid (12) is increased, the shearing strength is increased, and in turn, the resistance generated to the piston (7) is increased, thereby achieving the aim of vibration reduction. The voltage generated by the piezoelectric ceramic has a functional relation with the compression deformation, so that the larger the up-and-down movement amplitude of the piston (7), the higher the voltage generated by the piezoelectric ceramic (11) is, and the larger the resistance generated by the electrorheological fluid (12) is, thereby achieving the purpose of self-coupling vibration reduction. The piston rod can be applied to any side by applying external force, but the external force cannot be applied to any side simultaneously.

Claims

1. A double-rod uncompensated air chamber symmetric self-powered electrorheological fluid damper comprises an energy supply part consisting of a piston rod (22), a compression spring plate (2), a spring (3), a fixing plate (10), piezoelectric ceramics (11) and a lead (8); a damping cavity part consisting of an annular damping channel (14), an inner electrode plate (13), an outer electrode plate (15), a pore canal (16) and electrorheological fluid (12); the sealing device comprises a packaging part consisting of a cylinder body (17), a cylinder cover (18), an outer cylinder (9), an outer cylinder cover (21), a top cover (1), an O-shaped sealing ring (19), a bolt (4), a hexagon nut (5) and a gasket (6); the damping device is characterized in that two groups of energy supply parts are symmetrically arranged relative to the damping part, and can work without an external power supply and control equipment; a double-rod structure is used for replacing a common compensation air chamber and a common compensation valve; a guide ring (20) is arranged to ensure the stability of the movement of the piston rod; the inner electrode and the outer electrode are respectively embedded on the inner cylinder and the outer cylinder of the damper, and a damping channel is formed between the inner electrode and the outer electrode; the pore channels are arranged at two sides of the stroke end of the piston, so that the electrorheological fluid finishes the backflow.

2. The symmetrical self-energized electrorheological fluid damper with double out-rod uncompensated gas chambers as claimed in claim 1, wherein the energizing part consisting of the spring (3), the compression spring plate (2), the fixing plate (10) and the piezoelectric ceramics (11) is arranged symmetrically about the center of the damping chamber, and the piezoelectric ceramics work in both strokes to generate voltage to energize.

3. The symmetrical self-energized electrorheological fluid damper with double piston rods and uncompensated air chambers as claimed in claim 1, wherein the piston rod (22) and the piston (7) are fixed and have symmetrical structures with respect to the central section of the piston, and the piston rod extends out of the damping chamber without a volume compensation structure.

4. The symmetrical self-energized ERF damper with double out-rod uncompensated gas chambers as claimed in claim 1, wherein the piston rod guide ring (20) is disposed inside the piezoelectric ceramic.