JPH0384241A - Liquid sealed vibration isolator - Google Patents

Abstract

PURPOSE:To enlarge the range of a vibration isolating characteristic by partitioning the inside of a vibrationproof rubber body with electroviscous liquid sealed therein into two liquid chambers by small gaps formed by opposed wall surfaces formed along the relative movement of vibration and forming the opposed wall surfaces into electrodes. CONSTITUTION:Connecting members 2, 3 are connected by a vibrationproof rubber body 1, and a main liquid chamber A and an auxiliary liquid chamber B with electroviscous liquid sealed therein are formed and communicated through small gaps F between the wall surface 2a of the extended part 21 of the connecting member 2 and the inner peripheral surface 4a of a partition wall 4. The wall surface 2a and the inner peripheral surface 4a are formed along the moving direction accompanied by vibration input and form electrodes 5 opposedly. Shearing is generated to the electroviscous liquid in the small gap F by the relative movement accompanied by vibration input, thus performing damping action. The elasticity of the liquid is increased by enlarging applied voltage from a voltage supply 7, and a vibration damping characteristic is changed in a wide range.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid-filled vibration isolator, and more particularly to a liquid-filled vibration isolator whose vibration damping characteristics can be varied by sealing in an electroviscous liquid.

[Prior Art] A typical structure of a liquid-filled vibration isolator is that one of two connecting members with a vibration isolating rubber body interposed therebetween is connected to the vibrating body and the other to the base, and a vibration isolating member is connected to the vibration isolating rubber body. Liquid chambers are formed, and these liquid chambers, which deform in a complementary manner due to vibration input, are communicated through a throttle channel.

When vibration is input, the sealing liquid flows through the throttle channel, and the flow resistance generated at this time exerts an effective vibration damping effect.

Incidentally, in recent years, devices using an electrorheological (ER) liquid whose viscosity increases depending on the strength of the electric field as the sealing liquid have been proposed (for example, Japanese Patent Application Laid-Open No. 104828/1982, Japanese Patent Application Laid-Open No. 61-1982). No. 7930, these devices change the vibration damping characteristics of the device by forming electrodes on the walls of the throttle channel and changing the viscosity of the sealing fluid flowing through the throttle channel. .

[Problems to be Solved by the Invention] Incidentally, in the conventional vibration isolating device described above, the vibration damping force is obtained by the circulation of the sealing liquid due to the relative movement of the connecting members, and there is a problem that the damping force is indirect and therefore inefficient. There is. Also,
When the above-mentioned electrorheological liquid is used as a sealing liquid, its elasticity tends to increase as well as its viscosity as an electric field is applied, and if this increase in elasticity is effectively utilized, the vibration isolation characteristics can be further changed significantly. It is possible.

The present invention was made against this background, and an object of the present invention is to provide a liquid-filled vibration isolator whose vibration isolating characteristics can be varied widely depending on the purpose by effectively utilizing the characteristics of electrorheological liquid. do.

[Means for Solving the Problems] To explain the present invention in detail, a liquid-filled vibration isolator includes two connecting members that are connected to a vibrating body and a base body with a vibration isolating rubber body 1 (FIG. 1) interposed therebetween. 2.3, a pair of liquid chambers A and B are formed in the vibration isolating rubber body 1 and are deformed in a complementary manner as a result of vibration input, and an electric current whose viscosity changes due to an electric field is formed in these liquid chambers A and B. Each of the connecting members 2.3, which encloses a viscous liquid and moves relative to each other due to vibration input, has a wall surface 2 along the moving direction.
a, 4a are formed so that these wall surfaces 2a, 4a face each other with a small gap F, and both the liquid chambers A, B are communicated with each other through the small gap F, and the opposing wall surfaces 2a, 4a are provided with a small gap F. An electrode 5 is formed to form an electric field.

[Function] In the liquid-filled vibration isolator having the above configuration, when vibration is input, the connecting member 2.3 moves relatively, and the wall surfaces 2a and 4a facing each other in the small gap F also move relatively while maintaining the interval. At this time, since electrorheological liquid exists in the small gap F, the wall surfaces 2a and 4a
The resistance force due to the shearing of the electrorheological fluid acts directly on the vibration damping effect. The resistance force at this time can be easily adjusted by changing the voltage applied to the electrode 5 formed on the wall surface 4a.

Also, due to the relative movement of the connecting member 2.3, the liquid chamber A
, B are deformed in a complementary manner, and the sealed electrorheological liquid flows through the small gap F to the other liquid chamber A, t3. Vibration damping force is also generated by the resistance force when the electrorheological liquid flows.

When the applied voltage is increased, the elastic force of the electrorheological liquid increases accordingly, and this elastic force is applied to the connecting member 2.3, increasing the spring constant of the vibration isolator, contributing to suppressing large vibrations. do.

[Embodiment 2] In FIG. 1, a vibration-proof rubber body 1 has an umbrella-like thick body that expands downward, and a connecting member 2 is fixedly buried in the center. The connecting member 2 has an extending portion 21 extending downward in the shape of a rod from the center of the lower surface thereof, and has a flat upper surface on which a vibrating body such as an engine is placed and fixed.

The upper half of a cylindrical side plate 6 is joined to the outer periphery of the lower end of the vibration isolating rubber body 1, and the outer periphery of the partition wall 4 is fixed to the lower half of the side plate 6. The partition wall 4 is made of a thick inner rubber plate that slopes upward at the center, and a thick resin cylinder member 4 is joined to the inner periphery of the central opening of the rubber plate, and its inner circumferential surface 4a is connected to the above-mentioned extension. It faces the outer circumferential surface 2a of the protruding part with a small gap F (the second
Figure, Fig. 3〉.

An electrode 5 is formed on the inner circumferential surface 4a except for the opening edge, and the electrode 5 is connected to one end of an external voltage source 7 by a lead wire 71. The inner periphery of the opening edge of the cylindrical member 41 protrudes inward at four locations in the circumferential direction, and the protruding portions 42
(The tip of FIG. 2) is slidably in contact with the outer circumferential surface 2a of the extension part to maintain a small gap F.The connecting member 2 is connected to the voltage source 7 by a lead wire 72. connected to the other end.

A thin rubber sheet 8 is disposed below the partition wall 4, and the center portion of the rubber sheet 8 is liquid-tightly fixed to the lower end of the extension portion 21, and the outer peripheral edge is fixed to the lower end of the side plate 6. It is fixed in a liquid-tight manner at the bottom end.

Electrorheological fluid is sealed in the sealed space formed by the rubber sheet 8 and the vibration-isolating rubber body (2), and a main liquid chamber A is formed above the partition wall 4 with the vibration-isolating rubber body (2) as a chamber wall. ,
A sub-liquid chamber B is formed below with the rubber sheet 8 as a chamber wall.

A container-shaped connecting member 3 that supports the side plate 6 is disposed below the rubber sheet 8, and the connecting member 3 is fixed to a base such as a vehicle frame.

In the liquid-filled vibration isolator having the above structure, when vibration is input, the connecting member 2 moves relative to the connecting member 3 in the vertical direction, and the outer circumferential surface 2a of the extending portion facing with the small gap F becomes the inner circumference of the cylindrical member 41. It moves relative to the surface 4a while maintaining an interval. This causes shearing in the electrorheological fluid within the small gap F, and the resistance force due to this shearing directly acts on the outer circumferential surface 2a, producing a vibration damping effect. Here, when the voltage applied to the electrode 5 is increased, the viscosity of the electrorheological liquid increases, and an even greater resistance force acts on the extension, resulting in a greater vibration damping effect.

Further, when the connecting member 2 moves relative to each other, the main liquid chamber A is deformed, and the sealed electrorheological liquid flows into the sub liquid chamber B through the small gap F. A vibration damping force is also generated by the resistance force when the electrorheological liquid flows, and this vibration damping force is also increased by increasing the voltage applied to the electrode 5.

Furthermore, as the applied voltage increases, the elastic force of the electrorheological liquid also increases. Thus, this elastic force is applied to the extending portion 21, and the spring constant of the vibration isolator increases. In particular, when the applied voltage is sufficiently high, the flow of the electrorheological liquid in the small gap F is stopped, and no resistance damping force is applied to the extension portion 21, but only elastic force is applied.

In this way, the vibration damping performance and vibration suppression performance of the vibration isolator can be effectively varied over a wide range.

[Second Embodiment] FIGS. 4 to 6 show an example in which the present invention is applied to a cylindrical liquid-filled vibration isolator. In the figure, each connecting member 2.3 has a large-diameter outer cylinder and a small-diameter inner cylinder arranged at the center of the outer cylinder, and a vibration-proof rubber body l is connected and arranged between these inner and outer cylinders 2.3. It is. The outer cylinder 2 is fitted and fixed within a cylindrical bracket provided on the vibrating body, and a rod-shaped bracket provided on the base body is inserted and fixed into the inner cylinder.

The vibration isolating rubber body 1 has a sealed space formed in the center thereof, in which an electrorheological liquid is sealed. There are liquid chambers A and B. The partition wall 4 is a thick resin plate, and its outer periphery faces the inner periphery of the outer cylinder 2 with a small gap F therebetween. Electrodes 51 and 52 are formed on the outer periphery of the partition wall 4 and at the center of the inner periphery of the outer tube 2 facing the partition wall 4, and are connected to an external voltage source 7, respectively.

The outer periphery of the partition wall 4 has protrusions 42 (FIG. 5) provided at four locations in the circumferential direction at both ends that slidably abut against the inner periphery of the outer cylinder 62 to maintain the above-mentioned small gap F. There is.

When vibration is input and the inner cylinder 3 moves relative to the outer cylinder 2 in the axial direction, the electrorheological fluid existing in the small gap F produces a shear resistance region or damping force, and The electrorheological fluid flowing through both liquid chambers A and B generates a flow resistance damping force. Thus, this embodiment also provides the same effects as the above-mentioned Embodiment 2.

[Effects of the Invention] As described above, according to the liquid-filled vibration isolating device of the present invention, the vibration damping force of the shear resistance generated in the electroviscous liquid and the elastic force are efficiently utilized to improve the vibration damping characteristics of the device. It can be changed within a wide range depending on the purpose of use.

[Brief explanation of drawings]

1 to 3 show a first embodiment of the present invention.
The figure is an overall cross-sectional view of the device, with the cross-sectional portion taken along line II in Figure 2, Figure 2 being a cross-sectional view taken along line n-■ in Figure 1, and Figure 3 being a cross-sectional view taken along line II in Figure 1. 4 to 6 show a second embodiment of the present invention, FIG. 4 is an overall sectional view of the device, and FIG. 5 is a sectional view taken along line v-V in FIG. 4. Sectional view, No. 6
The figure is a sectional view taken along the line Vl-Vl in FIG. 4. l... Vibration isolating rubber body 2... Connecting member 2a... Wall surface 21... Extension part 3... Connecting member 4... Partition wall 4a... Wall surface 41... Cylindrical member 5 .51.52...Electrode 7...Voltage source A, B...Liquid chamber F...Small gap Figure 1 Figure 2 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] It has two connecting members that are connected to the vibrating body and the base with a vibration isolating rubber body interposed therebetween, and a pair of liquid chambers that deform complementary to each other in response to vibration input are formed within the vibration isolating rubber body. is filled with an electroviscous liquid whose viscosity changes depending on the electric field, while each of the connecting members moves relative to each other due to vibration input.
Wall surfaces extending along the moving direction are formed so that these wall surfaces face each other with a small gap, and the two liquid chambers are communicated through the small gap, and electrodes are formed on the opposing wall surfaces to form an electric field in the small gap. Features a liquid-filled vibration isolator.