Dual electric field hybrid electrorheological fluid damper

Abstract

The present application belongs to the field of mechanical and building structure vibration reduction technology, and discloses a double electric field mixed electrorheological damper, which comprises a pressure measuring connector, an outer cylinder and inner cylinder assembly, a piston assembly, a nylon sleeve and an end cover. A piston is arranged in the inner cylinder through a piston rod. The piston rod can drive the inner cylinder end to be uniformly provided with a constant hole. The gap between the inner cylinder and the outer cylinder forms a valve type electrorheological damper uniform electric field, and the gap between the piston and the inner cylinder forms a shear type electrorheological damper uniform electric field. The nylon sleeve insulates the inner cylinder and the outer cylinder, fixes the inner cylinder and limits the piston rod. The end cover fixes the inner cylinder and the nylon sleeve. The pressure measuring connector is connected to the outer cylinder for controlling the piston slip during application. The present application realizes parallel connection of the double electric field valve type electrorheological damper and the shear type electrorheological damper, suppresses the piston slip under small stroke of the damper, and has the advantages of small size, large power, high reliability, simple structure and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of dampers, and relates to a double-electric-field hybrid electrorheological damper, which is suitable for the industries of buildings, machines, vehicles, ships, aerospace, etc. BACKGROUND

[0002] The electrorheological fluid is a suspension formed by polarizable particles dispersed in a base fluid, and under the action of an applied electric field, the viscosity rheological behavior of the electrorheological fluid can change with the electric field strength, etc. The electrorheological fluid can change from a liquid that is easy to flow into a viscoelastic fluid, a semi-solid fluid or even a solid. The electrorheological fluid has mainly experienced two generations of development. The first generation is called dielectric electrorheological fluid. Through theoretical calculation based on the first principle, it is concluded that the shear strength of this type of electrorheological fluid can only reach about 10 kPa. The mechanism of the traditional electrorheological fluid determines that the yield stress is low, and it cannot meet the requirements of practical application. In 2003, Wen Weiga et al. proposed a giant electrorheological fluid in the article The giant electrorheological effect in suspensions of nanoparticles. Nature Materials, 2003, 2(11): 727-730. The yield strength of the giant electrorheological fluid exceeds 100 kPa. However, the fatal defect of the giant electrorheological fluid is that the coating or modification layer on the surface of the particles is easy to wear, resulting in the failure of the polar molecules. In 2023, Lu Kunquan et al. proposed an induced dipole dominant giant electrorheological fluid in the article Induced dipole dominant giant electrorheological fluid[J]. Chinese Physics B, 2023, 32(07): 633-642. The induced dipole electrorheological fluid has excellent comprehensive performance: high yield strength (> 100 kPa), low leakage current density (< 20µA / cm2), good temperature stability, wear resistance and sedimentation resistance. The preparation method is simple, has good repeatability, low cost and other advantages. This breakthrough shows the great application value of the electrorheological body to people.

[0003] The vibration or impact loads on various building structures or mechanical structures during their service life will seriously affect their safety and service life. Installing damping devices that can dissipate energy and reduce vibration on the structure is an effective means to reduce its vibration or impact response and increase its safety and stability. Traditional passive control dampers such as hydraulic dampers can only provide non-adjustable damping force and their vibration control effect is not ideal. Intelligent dampers made of electro / magnetic fluid can continuously adjust the damping force in real time according to the working conditions by adjusting the intensity of the electric / magnetic field, thereby achieving active and semi-active control of structural vibration or impact to better prevent structural failure and damage. Compared with magnetorheological dampers, electrorheological dampers with giant electrorheological fluid as the core material have the advantages of high stability, simple structure, large damping force adjustment range, and fast response.

[0004] According to the working principle, the ER damper is divided into shear mode ER damper, flow mode ER damper and compound mode ER damper. Working principle of shear mode ER damper: In general, the shear mode damper consists of several main parts, such as piston rod, piston body, electrode, working cylinder and accumulator. Figure 1 (a) As shown. Its main feature is that the pressure difference between the upper and lower chambers of the working cylinder is approximately equal to zero, the electrorheological fluid in the annular electrode gap is basically in a non-flowing state, and the damping force comes only from the shearing effect of the piston electrode on the fluid. The yield stress of the electrorheological fluid is adjusted by adjusting the electric field strength applied between the electrodes to achieve the purpose of adjusting the damping force. Working principle of flow mode electrorheological damper: The flow mode damper is mainly composed of a working cylinder, an accumulator, a working electrode, a piston body and a piston rod, as shown in FIG. Figure 1 (b) As shown. The important structural difference between it and the shear mode damper is that the piston body and the positive electrode of the working electrode are separate, that is, the electrode is fixed. When the piston reciprocates, a pressure difference is generated between the upper and lower chambers of the electrorheological fluid, and this pressure difference causes the electrorheological fluid to flow back and forth between the electrode gaps. The electrode gaps then throttle the electrorheological fluid, thereby forming a damping force. The purpose of adjusting the damping force can be achieved by adjusting the intensity of the working electric field applied between the electrodes. Working principle of composite mode electrorheological damper: The composite mode damper is also composed of a working cylinder, an accumulator, a working electrode, a piston body and a piston rod, as shown in FIG. Figure 1 (c) shows a combination of the common features of the two aforementioned dampers: the damping force is generated by the combined shearing effect of the piston on the electrorheological fluid as it flows through the gap between the working electrodes, and the throttling effect of the electrode gap on the electrorheological fluid. Changing the working voltage between the electrodes can change the rheological state of the fluid between the electrodes, thereby achieving the purpose of adjusting the damping force.

[0005] Due to the electric field setting problem and the single working form of the damper, the electro-rheological damper is usually required to provide larger damping force in actual engineering. However, due to the electric field setting problem and the single working form of the damper, the electro-rheological damper designed has larger volume and mass, and the setting of the electrode plate and the wire is complex. In addition, the piston rod slips due to the existence of air bubbles in the liquid filled in the damper. Therefore, it is urgent to develop a new type of electro-rheological damper with reasonable electric field setting, ingenious combination of shear type and valve type, small size and large output, and no piston rod slip, to meet the needs of industrial development. SUMMARY

[0006] The purpose of the present application is to provide an electro-rheological damper, which solves the problems of unique number and single form of the damping channel of the variable electric field, poor combination effect of the valve type and shear mode damper, and piston rod slip caused by liquid filling.

[0007] The technical scheme of the present application is as follows:

[0008] A double electric field mixed electro-rheological fluid damper comprises an outer cylinder, an inner cylinder, a piston rod, a piston, a left nylon sleeve, a right nylon sleeve, a left end cover, a right end cover and a pressure measuring connector. The inner ends of the left nylon sleeve and the right nylon sleeve are provided with inverted L-shaped annular grooves, and the two ends of the inner cylinder are respectively overlapped in the inverted L-shaped annular grooves of the left nylon sleeve and the right nylon sleeve. The outer cylinder is sleeved on the outside of the inner cylinder, the left nylon sleeve and the right nylon sleeve, and the two ends thereof are respectively aligned with the outer ends of the left nylon sleeve and the right nylon sleeve. The two ends of the outer cylinder are respectively sealed and connected through the left end cover and the right end cover. The pressure measuring connector is threadedly installed on the outer cylinder. The piston rod passes through the left end cover, the left nylon sleeve, the piston, the right nylon sleeve and the right end cover in sequence, and the two ends of the piston rod extend out of the damper. The piston is sleeved on the outside of the piston rod and is arranged at the middle position of the piston rod. The piston rod drives the piston to reciprocatingly stretch. The inner cylinder, the left nylon sleeve and the piston form a left cavity, the inner cylinder, the right nylon sleeve and the piston form a right cavity, and the inner cylinder and the outer cylinder form a valve type annular channel. The left cavity, the right cavity and the valve type annular channel are filled with electro-rheological fluid.

[0009] The right end cover and the right nylon sleeve are provided with wire through holes. The inner cylinder is connected to the positive electrode of the power supply as a positive electrode plate by welding the wire to the inner cylinder. The outer cylinder and the piston rod are provided with wires, and the outer cylinder serves as a negative electrode plate of the valve type electro-rheological damper and the piston serves as a negative electrode plate of the shear type electro-rheological damper.

[0010] The valve type annular channel between the inner cylinder (positive electrode plate) and the outer cylinder (negative electrode plate of the valve type electro-rheological damper) and the shear type annular gap between the inner cylinder (positive electrode plate) and the piston (negative electrode plate of the shear type electro-rheological damper) are both 1-2 mm.

[0011] The two ends of the inner cylinder are provided with uniform constant through holes according to the equal flow principle, which are used for the flow of the electro-rheological fluid in the left cavity, the right cavity and the valve type annular channel.

[0012] The right end cover and the right nylon sleeve are symmetrically provided with two liquid injection holes, and the liquid injection holes are sealed by rubber plugs.

[0013] The pressure measuring connector is connected to the outer cylinder and is aligned with any one of the two normal through holes at the two ends of the inner cylinder.

[0014] The left nylon sleeve and the right nylon sleeve are respectively provided with guide rings and shaft U-shaped rings between the piston, and are respectively provided with sealing O-shaped rings between the outer cylinder.

[0015] The left end cover, the right end cover and the inner cylinder are threadedly connected; the left end cover and the right end cover are respectively connected with the left nylon sleeve and the right nylon sleeve by screws, and the left nylon sleeve and the right nylon sleeve fasten the inner cylinder; the piston rod and the piston are solidified.

[0016] The outer cylinder, the inner cylinder, the piston rod and the piston are made of conductive materials, and the left nylon sleeve and the right nylon sleeve are made of toughened nylon materials.

[0017] The working principle of the present application is that when the piston rod reciprocates under the action of external force, the pressure difference of the current variable fluid between the left cavity and the right cavity is generated, and the pressure difference promotes a part of the current variable fluid to reciprocate between the left cavity and the right cavity through the shear type annular gap, and another part of the current variable fluid to reciprocate between the left cavity and the right cavity through the valve type annular channel through the normal through hole, so that the shear type annular gap and the valve type annular channel produce throttling effect on the current variable fluid, and further form damping force. By adjusting the working electric field intensity applied to the shear type annular gap and the valve type annular channel, the yield strength of the current variable fluid can be adjusted, and the damping force can be adjusted. Since the electric field continuously changes, the yield strength of the current variable fluid continuously changes, so the continuous change of the damping force of the damper can be realized.

[0018] The present application has the following beneficial effects:

[0019] (1) Two electric fields are arranged without changing the structure length, the valve type current variable damper and the shear type current variable damper are connected in parallel, and the effect of small size and large output is achieved;

[0020] (2) Two electric fields are arranged, the valve type and the shear type dampers are connected in parallel, and the shortcomings of the two types of dampers are mutually compensated;

[0021] (3) The double electric field arrangement improves the safety in application, when one electric field fails, the other electric field continues to work without causing the current variable damper to fail;

[0022] (4) In the double electric field arrangement, the valve type current variable damper and the shear type current variable damper share the same electric field anode, and this structure design is simpler, lighter, and has higher integration.

[0023] (5) The pressure measuring connector structure is added to the outer cylinder, and the rheological liquid can be filled into the pressure measuring connector after the damper is assembled and filled with liquid, the pressure in the cavity is increased, and the adverse effects caused by the bubbles are offset. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is an electric current damper working principle diagram, wherein (a) is a shear mode damper, (b) is a flow mode damper, and (c) is a composite mode damper;

[0025] Figure 2 It is a structural schematic diagram of the double electric field hybrid electrorheological fluid damper of the application;

[0026] Figure 3 It is a double electric field amplification structure schematic diagram;

[0027] Figure 4 It is an A-A cross section schematic diagram of the application, Figure 2 respectively used for showing the outer cylinder, the inner cylinder and the valve type annular channel structure formed between the outer cylinder and the inner cylinder, and respectively used for showing the piston, the inner cylinder and the shear type annular gap structure formed between the piston and the inner cylinder;

[0028] Figure 5 It is a B-B cross section schematic diagram of the application, Figure 2 used for showing the structure of the constant through hole on the inner cylinder and the internal right chamber;

[0029] Figure 6 It is a B-B cross section schematic diagram of the application, Figure 2 used for showing the arrangement structure of the right nylon sleeve, the inner cylinder, the outer cylinder and the right end cover;

[0030] Figure 7 It is a right nylon sleeve schematic diagram of the application, wherein (a) is an elevation cross section view, and (b) is a right view;

[0031] Figure 8 It is a right end cover schematic diagram of the application, wherein (a) is an elevation cross section view, and (b) is a right view;

[0032] In the figure: 1 left end cover; 2 O-shaped sealing ring; 3 left nylon sleeve; 4 guide ring; 5 U-shaped ring for shaft; 6 outer cylinder; 7 valve type annular channel; 8 inner cylinder; 9 piston; 10 shear type annular gap; 11 piston rod; 12 constant through hole; 13 right nylon sleeve; 14 right end cover; 15 screw; 16 wire through hole; 17 pressure measuring connector; 18 left cavity; 19 right cavity; 20 inverted L-shaped annular groove; 21 liquid injection hole. DETAILED DESCRIPTION

[0033] The specific implementation manner of the application will be described in detail below in combination with the technical scheme and the drawings.

[0034] The detailed description of the present application is shown in Figures 2 to 8 It can be seen that the double electric field mixed electrorheological fluid damper in the example comprises a pressure measuring connector 17, an outer cylinder 6, an inner cylinder 8, a piston 9, a piston rod 11, a left end cover 1, a right end cover 14, a left nylon sleeve 3, and a right nylon sleeve 13. The inner cylinder 8 is sleeved in the outer cylinder 6, and the left part and the right part of the inner cylinder 8 are uniformly distributed with constant through holes 12 along the circumference according to the equal flow principle. The pressure measuring connector 17 is threadedly connected to the outer side of the outer cylinder 6 and is aligned with any constant through hole position on the inner cylinder 8. The outer cylinder 6 is sleeved on the left nylon sleeve 3 and the right nylon sleeve 13, and the two ends of the inner cylinder 8 are respectively overlapped in the inverted L-shaped annular grooves of the left nylon sleeve 3 and the right nylon sleeve 13. The left nylon sleeve 3 and the right nylon sleeve 13 insulate the outer cylinder 6 and the inner cylinder 8 and form a uniform and equal gap valve type annular channel 7. The outer cylinder 6 and the left nylon sleeve 3 and the right nylon sleeve 13 are provided with the left end cover 1 and the right end cover 14, wherein the left end cover 1 and the right end cover 14 are threadedly connected with the outer cylinder 6, and the left end cover 1 and the right end cover 14 are boltedly connected with the left nylon sleeve 3 and the right nylon sleeve 13, respectively. The solid piston rod 11 penetrates through the left end cover 1, the right end cover 14, and the left nylon sleeve 3 and the right nylon sleeve 13, and the left end cover 1, the right end cover 14, and the left nylon sleeve 3 and the right nylon sleeve 13 limit the piston rod 11. The piston 9 is threadedly connected in the middle of the piston rod 11, and the piston 9 is sleeved in the inner cylinder 8 and forms a uniform shear type annular gap 10 with the inner cylinder 8. The wires are connected with the inner cylinder 8 through the wire through holes 16 on the right end cover 14 and the right nylon sleeve 13, and the right end cover 14 and the right nylon sleeve 13 are provided with liquid injection holes 20. The piston 9 divides the inner cylinder 8 into a left cavity 18 and a right cavity 19, and the left end and the right end of the inner cylinder 8 are uniformly distributed with constant through holes 12 along the circumference, which enables the liquid to flow in the left cavity 18 and the right cavity 19 through the valve type annular channel 7; at the same time, the liquid can flow in the left cavity 18 and the right cavity 19 through the shear type annular gap 10. The left nylon sleeve 3 and the right nylon sleeve 13 are provided with O-shaped sealing rings 2, guide rings 4, and shaft U-shaped rings 5 to prevent liquid leakage.

[0035] The working process of the present application is briefly described as follows:

[0036] The double electric field mixed electrorheological fluid damper is filled with electrorheological fluid, and a certain amount of electrorheological fluid is injected through the pressure measuring joint 17. The positive electrode of the power supply is connected to the wire, so that the inner cylinder 8 is connected to the positive electrode of the power supply, and the outer cylinder 6 and the piston rod 11 are grounded. In this way, the inner cylinder 8 becomes a positive plate, and the piston 9 is a negative plate through the piston rod 11 and the inner cylinder 8, respectively, and an electric field is formed between the valve type annular channel 7 and the shear type annular gap 10. In the powered state, when the piston rod 11 reciprocatingly moves under the action of an external force, part of the electrorheological fluid flows in the left cavity 18 and the right cavity 19 in the shear type annular gap 10, and part of the electrorheological fluid flows in the left cavity 18 and the right cavity 19 in the valve type annular channel through the two end holes in the inner cylinder. The electric field intensity values of the valve type damper and the shear type damper can be changed by changing the voltage value of the inner cylinder 8, i.e. the positive plate, so as to change the shear strength of the electrorheological fluid flowing through the valve type annular channel 7 and the shear type annular gap 10, thereby adjusting the output of the damper. The total output value of the damper is equal to the sum of the output values of the valve type electrorheological damper and the shear type electrorheological damper. Since the electric field changes continuously, the electric damping force of the electrorheological fluid changes continuously, so that the damping force of the damper changes continuously.

[0037] During use, if one of the negative plates fails, the double electric field mixed electrorheological damper becomes a parallel connection of a valve type electrorheological fluid damper and a shear type hydraulic damper, or a parallel connection of a shear type electrorheological fluid damper and a valve type hydraulic damper. If the positive plate fails or the input voltage value is 0, the damper becomes a parallel connection of a valve type hydraulic damper and a shear type hydraulic damper, and at this time, the damping coefficient of the damper is the smallest.

Claims

1. A dual electric field hybrid electrorheological fluid damper, characterized by, The double electric field mixed electrorheological fluid damper comprises an outer cylinder, an inner cylinder, a piston rod, a piston, a left nylon sleeve, a right nylon sleeve, a left end cover, a right end cover and a pressure measuring connector; the inner ends of the left nylon sleeve and the right nylon sleeve are provided with inverted L-shaped annular grooves, and the two ends of the inner cylinder are respectively overlapped in the inverted L-shaped annular grooves of the left nylon sleeve and the right nylon sleeve; the outer cylinder is sleeved outside the inner cylinder, the left nylon sleeve and the right nylon sleeve, and the two ends of the outer cylinder are respectively aligned with the outer ends of the left nylon sleeve and the right nylon sleeve; the two ends of the outer cylinder are respectively sealed and connected through the left end cover and the right end cover; the pressure measuring connector is threadedly installed on the outer cylinder; the piston rod passes through the left end cover, the left nylon sleeve, the piston, the right nylon sleeve and the right end cover in sequence, and the two ends of the piston rod extend out of the damper; the piston is sleeved outside the piston rod and arranged at the middle position of the piston rod, and the piston rod drives the piston to reciprocatingly stretch; the inner cylinder, the left nylon sleeve and the piston form a left cavity, the inner cylinder, the right nylon sleeve and the piston form a right cavity, and the inner cylinder and the outer cylinder form a valve type annular channel, and the left cavity, the right cavity and the valve type annular channel are filled with electrorheological fluid; The right end cover and the right nylon sleeve are provided with wire through holes, and wires are welded to the inner cylinder to make the inner cylinder connected to a positive electrode as a positive plate, and wires are led out of the outer cylinder and the piston rod to make the outer cylinder a negative plate of the valve type electrorheological damper and the piston a negative plate of the shearing type electrorheological damper; The valve type electrorheological damper and the shearing type electrorheological damper are connected in parallel. The two ends of the inner cylinder are provided with uniform distribution constant through holes according to the equal flow principle, and the constant through holes are used for the flow of the electrorheological fluid in the left cavity, the right cavity and the valve type annular channel.

2. The dual-field hybrid electrorheological fluid damper of claim 1, wherein, The valve type annular channel between the inner cylinder and the outer cylinder and the shearing type annular gap between the inner cylinder and the piston are both 1-2 mm.

3. The dual-field hybrid electrorheological fluid damper of claim 1, wherein, Two liquid injection holes are symmetrically arranged on the right end cover and the right nylon sleeve, and the liquid injection holes are sealed by rubber plugs.

4. The dual-field hybrid electrorheological fluid damper of claim 1, wherein, The pressure measuring connector is connected to the outer cylinder and aligned with any constant through hole at the two ends of the inner cylinder.

5. The dual-field hybrid electrorheological fluid damper of claim 1, wherein, Guide rings and shaft U-shaped rings are arranged between the left nylon sleeve, the right nylon sleeve and the piston, and sealing O-shaped rings are arranged between the left nylon sleeve, the right nylon sleeve and the outer cylinder.

6. The dual-field hybrid electrorheological fluid damper of claim 1, wherein, The left end cover, the right end cover and the outer cylinder are threadedly connected; the left end cover and the right end cover are connected with the left nylon sleeve and the right nylon sleeve by screws, and the left nylon sleeve and the right nylon sleeve fasten the inner cylinder; the piston rod and the piston are fixedly connected.

7. The dual-field hybrid electrorheological fluid damper of claim 1, wherein, The outer cylinder, the inner cylinder, the piston rod and the piston are made of conductive materials, and the left nylon sleeve and the right nylon sleeve are made of toughened nylon materials.

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