JPH102369A - Damper using electroviscous fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably prevent leakage of electroviscous fluid to the outside in addition to the reduction of the size of the whole of a device. SOLUTION: A moving table 3 is vertically movably arranged through a fixed table 2 and springs 4 is arranged between the fixed table 2 and the moving frame 3 and the moving table 3 is always energized in a direction, in which the moving table is lifted from the fixed table 2, through the spring force of the spring 4. Further, an electrode 9 on the fixed side is arranged on the fixed table 2 side and an electrode 10 on the moving side is arranged on the moving table 3 side such that restriction passages 11 are formed in a septuple cylindrical shape on a whole between the electrode 9 on the fixed side and the electrode on the moving side. An expandable bag body 7 between the fixed table 2 and the moving table 3, the electrodes 9 and 10 are contained in the bag body 7, which is filled with electroviscous fluid 8. This constitution regulates inner capacity of inside chambers A, A,... following forward and backward movement operation of the moving table 3 and holds the electroviscous fluid 8 in a closed state in the bag body 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper using an electrorheological fluid which is suitably used for damping a vibration acting on a vehicle, a precision instrument, or the like, and more particularly, to a damper capable of appropriately adjusting a damping force. The present invention relates to a damper using an electro-rheological fluid.

[0002]

2. Description of the Related Art Generally, vehicles, precision equipment, and the like are equipped with a damper for damping external vibrations and shocks. As such a damper, for example, a damper using an electrorheological fluid described in Japanese Patent Application Laid-Open No. 4-95628 (hereinafter, referred to as a prior art) is known.

In this type of conventional damper, one end of a rod as a movable portion is inserted into a cylinder as a fixed portion filled with an electrorheological fluid, and the other end of the rod is projected outside the cylinder. At the same time, a piston is slidably inserted into the cylinder, and the piston is attached to one end of the rod. In addition, a flow passage as a throttle passage is formed in the piston, and the rod side chamber and the bottom side chamber defined through the piston in the cylinder by the flow passage communicate with each other. A pair of electrode plates are arranged on the flow passage side so as to face each other, for example, in the radial direction of the piston, and each of the electrode plates is externally energized.

In the extension process of the rod, when the electrorheological fluid flows through the flow passage from the rod side chamber to the bottom side chamber, an electric field is generated between the respective electrode plates, whereby the electrorheological fluid is generated. Increase viscosity. As a result, the flow resistance of the electrorheological fluid flowing in the flow passage increases, and a damping force is generated. Also, in the same manner as in the above-described extension stroke, when the electrorheological fluid flows through the flow passage from the bottom chamber to the rod chamber, an electric field is generated between the respective electrode plates in the same manner as in the above-described extension stroke. The damping force is generated by increasing the flow resistance of the viscous fluid.

[0005]

In the prior art described above, one of the two ends of the rod projects out of the cylinder, so that the rod occupies the cylinder as the rod expands and contracts. The approach volume changes. Therefore, in the related art, a gas chamber that can expand and contract in accordance with the expansion and contraction of the rod is provided on the bottom side of the bottom side chamber,
The gas chamber is expanded and contracted following the expansion and contraction of the rod, thereby compensating for the change in the entering volume of the rod.

However, in such a conventional technique, it is necessary to provide the gas chamber on the bottom side of the cylinder, which complicates the structure of the entire cylinder and increases the size of the entire cylinder in the axial direction of the cylinder. Therefore, there is a problem that it is difficult to reduce the overall size.

Further, in the prior art, the gap formed in the sliding portion of the rod with respect to the cylinder is sealed with a seal member or the like, so that the electrorheological fluid filled in the cylinder leaks to the outside through the gap. Is to be suppressed. However, since the rod is in direct contact with the electrorheological fluid in the cylinder, a part of the electrorheological fluid leaks to the outside while being attached to the rod as the rod expands and contracts. Then, there is a problem that the structure of the seal member is complicated in order to reduce the leakage amount of the electrorheological fluid to the outside. In addition, when a large load (vibration) acts on the rod side, the hydraulic pressure of the electrorheological fluid acts as a load, which greatly acts on the seal member, and the seal member is damaged early. .

In another conventional damper using an electrorheological fluid, both ends of a rod are projected from both ends of a cylinder so that the rod enters the cylinder at a constant volume when the rod expands and contracts. A configuration in which the gas chamber as described in the related art can be made unnecessary is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-288644 (hereinafter referred to as other related art).

However, even in such other conventional techniques, it is necessary to seal the gap between the cylinder and the rod with a sealing member or the like in order to suppress the leakage of the electrorheological fluid filled in the cylinder to the outside. There is a problem similar to that of the above-described related art.

[0010] The present invention has been made in view of the above-described problems of the prior art, and the present invention can reduce the size of the entire apparatus and can securely seal an electrorheological fluid inside. It is an object of the present invention to provide a damper using an electrorheological fluid capable of preventing the electrorheological fluid from leaking to the outside.

[0011]

In order to solve the above-mentioned problems, a damper using an electrorheological fluid according to the present invention comprises a fixed base, a movable base provided to be able to advance and retreat with respect to the fixed base, and A biasing means for constantly biasing the movable table to one of the directions for moving the movable table with respect to the fixed table, and an urging fluid provided between the movable table and the fixed table and filled with an electrorheological fluid. An expandable / contractible case, a movable-side electrode and a fixed-side electrode that are fixed in the movable-table side and the fixed-table side, respectively, and are formed between the movable-side electrode and the fixed-side electrode. A fluid chamber formed between the movable-side electrode and the fixed-side electrode, the fluid passage communicating between the inside and outside of the fluid chamber, and the movable-side electrode; And the current to the fixed side electrode is controlled to Lies in the configuration of the energization control means for varying the viscosity of the.

With this configuration, when the movable table is moved forward and backward with respect to the fixed table, the electrorheological fluid inside and outside the fluid chamber which expands and contracts by the forward and backward movement flows in the case via the fluid passage. become. At this time, by energizing the electrodes from the energization control means and generating an electric field between the electrodes, the viscosity of the electrorheological fluid flowing through the fluid passage can be increased, The damping force can be increased by increasing the flow resistance. In addition, the magnitude of the damping force can be appropriately adjusted by changing the electric field generated between the electrodes by the power supply control means.

Here, when the movable table is moved forward and backward, the case can be expanded and contracted following the movement of the movable table to absorb the deformation of the fluid chamber. It is not necessary to use a sliding part such as the above, and the electrorheological fluid can be securely sealed in the case, and leakage of the electrorheological fluid to the outside can be reliably prevented.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 to 3 show a damper using an electrorheological fluid according to an embodiment of the present invention.

In the drawing, reference numeral 1 denotes a floor, 2 denotes a fixed base fixed on the floor 1, and the fixed base 2 includes a bottom plate 2A and a cylindrical plate 2B.
The bottom plate 2A is formed with a through hole 2C for a connection terminal 12 described later. 3
Is provided so as to be able to move up and down with respect to the fixed base 2,
For example, a movable table above which a precision device such as a computer is installed (in the drawing), the movable table 3 includes an upper plate 3A and a cylindrical plate 3B.
From the above, it is formed as a bottomed cylindrical body in the same manner as the fixed base 2.

A through hole 3C for a connection terminal 13 to be described later is formed in the upper plate portion 3A, and an annular concave groove 3D is formed along the circumferential direction on the opening side end surface of the cylindrical plate portion 3B. Are formed. The movable base 3 is provided so that the cylindrical plate part 3B is slidable in the cylindrical plate part 2B of the fixed base 2. When vibration or the like acts on the movable base 3, an axial direction of the cylindrical plate part 2B ( (Up and down directions).

Reference numeral 4 denotes a spring as an urging means provided so as to be extendable and contractible between the fixed base 2 and the movable base 3. The upper and lower ends of the spring 4 are connected to the outer periphery of the bottom plate 2A of the fixed base 2 and the movable base 3 is provided with a predetermined spring force between the inside of the annular groove 3C and constantly biases the movable table 3 in a direction of lifting the movable table 3 upward from the fixed table 2.

Reference numerals 5 and 6 denote insulating plates formed in a disc shape, respectively. Of the insulating plates 5 and 6, the insulating plate 5 is integrally attached to the upper surface of the bottom plate 2A of the fixing base 2, and Numeral 6 is attached integrally to the lower surface of the upper plate 3A of the movable base 3. The insulating plates 5 and 6 electrically insulate the fixed base 2 and the movable base 3 from a fixed electrode 9 and a movable electrode 10, respectively, which will be described later, thereby ensuring the safety of the apparatus.

Reference numeral 7 denotes a bag as a case provided between the fixed base 2 and the movable base 3 so as to be able to expand and contract. The bag 7 is formed in a tubular shape from a flexible material such as an elastic resin. The lower opening end and the upper opening end are integrally fixed to the outer peripheral portions of the insulating plates 5 and 6 in a liquid-tight manner. And
The bag 7 contains electrodes 9 and 10 to be described later and is filled with an electrorheological fluid 8.

Here, as shown in FIG. 1, when the movable table 3 is retracted so as to be lifted upward from the fixed table 2, the bag body 7 contracts in the radial direction following this retracting operation. . On the other hand, when the movable table 3 enters the fixed table 2 downward as shown in FIG. 3, the bag body 7 expands in the radial direction following this approach operation.

Numeral 8 denotes an electrorheological fluid filled in the bag body 7, and the viscosity of the electrorheological fluid 8 changes due to an electric field generated between the electrodes 9 and 10, and the viscosity changes according to the magnitude of the electric field. Is increased.

Reference numeral 9 denotes a fixed electrode provided inside the bag 7 and provided on the fixed base 2 side. The fixed electrode 9 overlaps the upper surface of the insulating plate 5 as shown in FIGS. The disk-shaped electrode plate portion 9A fixed as described above, and the electrode plate portion 9
A rod-shaped electrode portion 9B extending upward in a cylindrical shape from the center of A to the movable base 3 side, and the rod-shaped electrode portion 9B
Are formed concentrically with the rod-shaped electrode portion 9B so as to surround from the outside, and extend upward, respectively, and are constituted by first to third cylindrical electrode portions 9C to 9E having a triple structure with each other. .

Here, the rod-shaped electrode portion 9B and the cylindrical electrode portions 9C to 9E are formed to have substantially the same dimensions as each other, and these electrode portions 9B to 9E are formed.
Are arranged at substantially the same intervals in the radial direction, thereby forming a cylindrical gap having a triple structure therebetween. And the fixed side electrode 9 is the movable side electrode 10
Together with the electrorheological fluid 8 filled in the bag body 7, and the fixed-side electrode 9 is externally energized by a power supply 18 via a connection terminal 12, a lead wire 19, and the like, which will be described later. And an electric field is generated between them.

Reference numeral 10 denotes a movable-side electrode provided on the movable base 3 via the insulating plate 6;
As shown in the figure, a disk-shaped electrode plate portion 10A integrally attached so as to overlap the lower surface of the insulating plate 6, and a cylindrical shape from the center side of the electrode plate portion 10A to the fixed base 2 side. A first cylindrical electrode portion 10B having a small diameter and extending downward, and a cylindrical electrode portion 10B surrounding the cylindrical electrode portion 10B from outside.
Each of the second and fourth cylindrical electrode portions 10C to 10E extends downward concentrically with B and has a quadruple structure together with the cylindrical electrode portion 10B.

Here, the cylindrical electrode portions 10B to 10E are formed to have substantially the same dimensions as the rod-shaped and cylindrical electrode portions 9B to 9E of the fixed-side electrode 9 and have substantially the same thickness. 9B to 9E are arranged at substantially the same interval in the radial direction, thereby forming a cylindrical gap having a quadruple structure therebetween. In addition,
These electrode portions 9B to 9E and 10B to 10E do not come into contact with each other because the movable table 3 is guided by the fixed table 2.

.., 11, 11,...
Each of the throttle passages 11 is a rod-shaped electrode portion 9B and a cylindrical electrode portion 9C formed as a fluid passage formed between B to 9E and the electrode portions 10B to 10E of the movable side electrode 10.
To 9E and the cylindrical electrode portions 10B to 10E are formed as a seven-layer cylindrical space as a whole. And
As shown in FIG. 2, the opening on the outermost peripheral side of each of the throttle passages 11 is an annular outflow / inlet port 11 </ b> A, and the outflow / inlet port 11 </ b> A is filled with the electrorheological fluid 8 between the fixed electrode 9 and the movable electrode 10. It is allowed to flow in and out.

Here, when the movable-side electrode 10 moves downward from the position shown in FIG. 1 toward the position shown in FIG. 3 toward the fixed-side electrode 9, the inner chamber A, which serves as a fluid chamber between the electrodes 9, 10.
A,... Toward the outer chamber B on the bag 7 side
Leaks out. On the other hand, when the movable side electrode 10 retreats so as to lift upward from the fixed side electrode 9, the electrorheological fluid 8 flows from the outer chamber B toward the inner chamber A.

Reference numerals 12 and 13 denote upper and lower connection terminals. Of the connection terminals 12 and 13, one end of the connection terminal 12 is connected to the control unit 15 via a lead wire 19 described later, and the other end is fixed. From the through hole 2C of the base 2 to the insulating plate 5
And is connected to the electrode plate 9A side of the fixed side electrode 9. One end of the connection terminal 13 is connected to the control unit 15 via a lead wire 20 described later, and the other end of the connection terminal 13 penetrates through the insulating plate 6 through the through hole 3 </ b> C of the movable base 3. It is connected to the 10A side.

Reference numeral 14 denotes a displacement sensor provided on the movable base 3. The displacement sensor 14 is constituted by a vibration sensor or a stroke sensor, etc., and detects the up / down state of the movable base 3 and the vibration state of the movable base 3. Is detected and output to the control unit 15.

Reference numeral 15 denotes a control unit which constitutes a power supply control means. The control unit 15 is connected to the displacement sensor 14 and the power supply 18 via leads 16 and 17 and the like, and is connected via leads 19 and 20. Terminals 12 and 13 are connected. Then, the control unit 15 controls the movable base 3 output from the displacement sensor 14.
Calculating the optimum damping ratio for this frequency based on the frequency and the like of the above, calculating the applied voltage necessary to realize this damping ratio, and outputting this applied voltage to the electrodes 9 and 10. It is.

The damper according to the present embodiment has the above-described configuration, and its operation will be described below.

First, the upper and lower vibrations from the outside act on the movable base 3, and when the movable base 3 descends downward toward the fixed base 2 as shown in FIG. The viscous fluid 8 flows in each of the throttle passages 11 and flows from inside the inner chambers A, A,.
Out toward the outer chamber B on the side. On the other hand, the movable base 3 is shown in FIG.
When the electrorheological fluid 8 rises upward from the fixed base 2 side by the spring force of the spring 4 as shown in FIG. 7, the electrorheological fluid 8 flows from the outer chamber B to the inner chambers A, A,. It flows in each of the throttle passages 11.

At this time, the control unit 15 energizes the electrodes 9 and 10 to generate an electric field between the electrodes 9 and 10, thereby increasing the viscosity of the electrorheological fluid 8 flowing in each of the throttle passages 11. The damping force can be increased by increasing the flow resistance of the electrorheological fluid 8. In addition, the control unit 15 controls the movable table 3 detected by the displacement sensor 14.
Calculates an optimal damping ratio with respect to this frequency based on the frequency and the like, and outputs an applied voltage necessary for realizing this damping ratio to the electrodes 9 and 10. It is possible to provide the damper with an optimal damping characteristic with respect to the acting vibration.

The control unit 15 receives the ascending / descending state of the movable base 3 from the displacement sensor 14, and thereby, when the movable base 3 is raised and lowered, the electrodes 9 from the control unit 15 are moved. , 10 can be separately changed, whereby the damping force generated at the time of rising and falling can be appropriately adjusted independently.

Here, as described above, when the movable electrode 10 is moved back and forth with respect to the fixed electrode 9 provided on the fixed base 2 together with the movable base 3, the bag body follows the forward / backward movement of the movable base 3. By performing the expansion / contraction operation in the radial direction, the total capacity of the inner chambers A, A,...

Therefore, in the present embodiment, a bag 7 is provided between the fixed table 2 and the movable table 3 so as to be able to expand and contract. The fixed electrode 9 is provided in the bag 7 and the movable table 3 is provided. A movable side electrode 10 is provided on the side 3, and an electrorheological fluid 8 is provided in the bag body 7.
, It is not necessary to specially provide a gas chamber or the like as described in the prior art below the fixed base 2 or the like, thereby simplifying the entire structure of the damper and moving the whole damper vertically (movable base 3). In the forward and backward directions), and the size of the damper can be reduced.

Since the electrorheological fluid 8 filled between the fixed table 2 and the movable table 3 can be held in the bag 7 in a sealed state, the electrorheological fluid 8 is placed on the movable table 3 side as described in the prior art. 8 can be reliably prevented from adhering and leaking to the outside. This eliminates the need to particularly provide a seal member or the like at the sliding portion between the fixed base 2 and the movable base 3, thereby simplifying the seal structure. Therefore, the damper can be applied even under a condition in which a large load (vibration) acts on the movable base 3 side.

In the above embodiment, the electrodes 9, 10
The rod-shaped electrode portions 9 are respectively attached to the electrode plate portions 9A and 10A.
B, the cylindrical electrode portions 9C to 9E and 10B to 10E have been described. Alternatively, for example, a plurality of flat plates may be erected in parallel on the electrode plate portions 9A and 10A. Or the spiral plate is attached to the electrode plate portion 9.
A and 10A may be provided respectively.

In the above embodiment, the movable table 3 is moved up and down with respect to the fixed table 2. However, for example, the movable table 3 is moved obliquely with respect to the fixed table 2. You may do so.

Further, in the above-described embodiment, the movable table 3 is moved forward and backward with respect to the fixed table 2 fixed on the floor 1, but instead, the movable table 3 is moved between the fixed table 2 and the movable table 3. The mounting relationship may be reversed, for example, a fixed base may be provided on the upper side, and a movable base capable of moving forward and backward with respect to the fixed base may be provided below the fixed base.

Further, in the above-described embodiment, the damper for fixing the fixed base on the floor and installing a precision device such as a computer on the movable base to attenuate the vibration is shown. Vibration may be attenuated by interposing the damper between the vehicle body and the axle, which are relatively displaced when passing through the unevenness of the road surface.

Further, in the above-described embodiment, the urging means for constantly urging the movable table in the direction of retracting the movable table from the fixed table has been described. However, the urging means is always urged in the direction of moving the movable table to the fixed table. It may be. In this case, the vibration can be favorably attenuated by interposing the damper between a wire of a suspension vehicle such as a ropeway or a lift and a passenger compartment or a seat.

[0044]

As described in detail above, according to the present invention, the biasing means for constantly biasing the movable table in one of the directions for moving the movable table relative to the fixed table. ,
And a scalable case filled with an electrorheological fluid therein is provided between the movable table and the fixed table, and the fixed electrode on the fixed table side and the movable electrode on the movable table side are provided in the case. And a fluid chamber is formed between the fixed-side electrode and the movable-side electrode, and a fluid passage communicating between the inside and outside of the fluid chamber is formed. Without special provision, the case can be expanded and contracted by following the advance and retreat of the movable table, the forward and backward movement of the movable table with respect to the fixed table can be compensated, the overall structure of the damper can be simplified, and the overall size can be reduced. it can.

Further, since the electrorheological fluid filled in the case can be held in a sealed state between the fixed base and the movable base, there is no need to particularly provide a seal member or the like at the sliding portion between the fixed base and the movable base. , The sealing structure can be simplified,
The damper can be applied even under a condition where a large load (vibration) acts on the movable table side.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a damper according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part in FIG. 1, showing a fixed side electrode, a movable side electrode, a throttle passage, and the like.

FIG. 3 is a longitudinal sectional view substantially similar to FIG. 1 showing a lowered state in which a movable table has entered a fixed table.

[Explanation of symbols]

 Reference Signs List 2 fixed base 3 movable base 4 spring (biasing means) 7 bag body (case) 8 electrorheological fluid 9 fixed side electrode 10 movable side electrode 11 throttle passage (fluid passage) 15 control unit (energization control means) A inner chamber ( Fluid chamber)

Claims (1)

[Claims] 1. A fixed table, a movable table provided so as to be able to advance and retreat with respect to the fixed table, and a moving direction of the movable table with respect to the fixed table.
An energizing means for constantly energizing one of them; an expandable and contractable case provided between the movable base and the fixed base and filled with an electrorheological fluid therein; A movable-side electrode and a fixed-side electrode fixed respectively to the table side and the fixed table side, and formed between the movable-side electrode and the fixed-side electrode, and expanded and contracted as the movable table moves forward and backward with respect to the fixed table. A fluid chamber, a fluid passage formed between the movable-side electrode and the fixed-side electrode, and communicating between the inside and the outside of the fluid chamber; and controlling the energization of the movable-side electrode and the fixed-side electrode to form the electrorheological fluid. A damper using an electrorheological fluid, comprising: an energization control means for changing the viscosity of the fluid.