JPS61290250A - Vibro-isolating device - Google Patents

Abstract

PURPOSE:To enable device to absorb a vibration in many directions, by connecting coaxially arranged inner and outer cylinders through elastic members while sealing a hollow chamber between said elastic members with high viscous fluid. CONSTITUTION:A vibro-isolating device 10 coaxially arranges an inner cylinder 12 and an outer cylinder 14 while provides cylindrical elastic members 16 to be interposed between the both cylinders. And a hollow chamber 20, formed by the fellow elastic members 16, is sealed inside with high viscous fluid. When a relative movement is generated between the inner cylinder 12 and the outer cylinder 14, the device, even if it moves in any direction, effectively absorbs a vibration by internal friction force of the elastic member 16 and friction force between the fluid and the inner and outer cylinders.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration isolating device used for engine mounts, shaft couplings, center supports, bushing materials, etc.

[Background technology and matters to be solved]

As a vibration isolating device for absorbing engine vibrations, etc., a structure is used in which two hollow chambers are provided inside an elastic body that connects an inner and outer cylinder, and these are communicated through an orifice.

In this vibration isolator, when the inner and outer cylinders move relative to each other, one hollow chamber receives a compression force and the other hollow chamber receives an expansion force, so the resistance force when the water in the hollow chamber moves to the other causes vibrations. Absorbed.

However, in such a vibration isolator, the direction in which vibration acts is limited, and if vibration acts in a different direction, it is not possible to obtain an effective damping force.

The present invention takes the above-mentioned facts into consideration and aims to provide a vibration isolator that can absorb vibrations even from different directions.

[Summary and operation of the invention]

The vibration isolator according to the present invention is characterized in that the inner and outer cylinders arranged coaxially are connected by an elastic body, and the elastic body has a hollow chamber partially filled with a highly viscous fluid.

Therefore, in the present invention, when the inner and outer cylinders move relative to each other, the highly viscous fluid provides resistance to the relative movement, thereby making it possible to effectively absorb vibrations in different directions.

(Embodiment of the invention) FIG. 1 shows a vibration isolator 1 to which a first embodiment of the invention is applied.
0 is shown. In this vibration isolator 10, an outer cylinder 14 is disposed coaxially with an inner cylinder 12. The inner peripheries of cylindrical elastic bodies 16 are vulcanized and bonded to the inner tube 12 at both ends in the axial direction.

The outer circumferences of these elastic bodies 16 are vulcanized and bonded to the inner circumference of the intermediate outer cylinder 18, respectively. Therefore, when the intermediate outer cylinder 18 is press-fitted into the outer cylinder 14, a hollow chamber 20 is formed between the pair of elastic bodies 16 and between the inner cylinder 12 and the outer cylinder 14.

In this embodiment, a highly viscous fluid (10
000~100000cS1. , centistokes) are included. The fluid to be sealed may have an even higher viscosity. Minute irregularities may be formed on the inner circumferential surface of the outer cylinder 14 and the outer circumferential surface of the inner cylinder 12 in order to increase the frictional resistance against the fluid.

By extending a portion of the elastic body 16 to the outer periphery of the intermediate outer cylinder 18, the airtightness between the elastic body 16 and the outer cylinder 14 can be improved when the elastic body 16 is press-fitted into the outer cylinder 14.

In the vibration isolator 10 of this embodiment configured in this way, -
For example, if one of the inner cylinder 12 and outer cylinder 14 is attached to the vehicle body and the other to the engine, engine vibrations can be effectively absorbed.

That is, when the inner cylinder 12 and the outer cylinder 14 move relative to each other in the directions of arrows A and B in FIG. 2 or in the radial direction crossing these directions,
In addition to the elastic body 16 absorbing vibrations by the resistance force caused by internal friction, the fluid can also absorb vibrations by the friction force generated between the inner cylinder 12 and the outer cylinder 14. This vibration can be absorbed not only in the radial direction but also when the inner cylinder 12 and the outer cylinder 14 rotate relative to each other as in the direction of arrow C.

Next, FIGS. 4 to 6 show a vibration isolating device according to a second embodiment of the present invention.

This embodiment differs from the previous embodiment in that a movable ring 22 is provided within the hollow chamber 20.

Which movable ring 22 has protrusions 22B, 22G from both sides in the width direction of a ring-shaped base 22A which is arranged substantially coaxially with the outer periphery of the inner cylinder 12 at a minute interval and has a T-shaped cross section.
are projected in the axial direction and alternately.

Therefore, these protrusions 22B and 22C have a large resistance force against the enclosed fluid when they move.

Therefore, in this embodiment, the movable ring 22 moves relative to the inner cylinder 12 during high-frequency minute vibrations, and can lower the dynamic magnification, which is the ratio of the dynamic spring constant to the static spring constant. It is preferable that the movable ring 22 has a specific gravity comparable to that of the viscous fluid in which it is sealed. Also, this movable ring 2
If 2 is made of a flexible member such as rubber, vibration can be absorbed by contacting and deforming the inner cylinder 12 or the outer cylinder 14 at the time of low frequency and large amplitude.

Next, FIG. 7 shows a third embodiment of the present invention. In this embodiment, unlike the previous embodiment, the base 22A of the movable ring 22 is disposed close to the inner periphery of the outer cylinder 14, and a plurality of projections and depressions are formed on the inside facing the inner cylinder 12. Therefore, the same effects as in the previous embodiment can be expected in this embodiment as well.

Next, FIG. 8 shows a vibration isolator according to a fourth embodiment of the present invention. In this embodiment, a bracket 26 protrudes from a part of the inner cylinder 12, and a movable member 28 passing through the bracket 26 is attached to the bracket 26 at its center so as to be able to move minutely, and has a plurality of projections and depressions 30 on both ends. is formed and has a large resistance to the enclosed viscous fluid.

Therefore, in this embodiment as well, the same effects as in the previous embodiment can be obtained. A plurality of movable members 28 may be provided, or they may be attached to the outer cylinder 14.

In the improved registration example, the movable ring 22 and the movable member 2
8 does not necessarily have to be provided floatingly on the inner cylinder 12 and outer cylinder 14, but can also be attached via a flexible member such as thin rubber.

〔Effect of the invention〕

As explained above, in the vibration isolating device according to the present invention, the inner and outer cylinders arranged coaxially are connected by an elastic body, and a hollow chamber is provided in a part of the elastic body, and a highly viscous fluid is sealed therein. Because of its characteristics, it has an excellent effect of reliably absorbing vibrations in different directions.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a first embodiment of the vibration isolator according to the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is an exploded perspective view of the first embodiment. 4 is a sectional view showing a second embodiment of the present invention, FIG. 5 is a sectional view taken along the line V-V in FIG. 4, FIG. 6 is a cutaway perspective view showing the movable ring of the second embodiment, and FIG. and FIG. 8 are sectional views corresponding to FIG. 2 showing the third and fourth embodiments of the present invention. DESCRIPTION OF SYMBOLS 10... Vibration isolator, 12... Inner cylinder, 14... Outer cylinder, 16... Elastic body, 20... Hollow chamber, 22... Movable ring, 28... Movable member.

Claims (4)

[Claims] (1) A vibration isolator characterized in that an elastic body connects coaxially arranged inner and outer cylinders, a hollow chamber is provided in a part of the elastic body, and a highly viscous fluid is sealed in the hollow chamber. (2) The inner and outer cylinders arranged coaxially are connected by an elastic body, a hollow chamber is provided in a part of the elastic body, a highly viscous fluid is sealed, and the inner cylinder or outer cylinder is inserted into this hollow chamber. A vibration isolator characterized by having a movable member that moves minutely relative to each other. (3) The vibration isolator according to claim (2), wherein the movable member has a large number of projections and depressions formed facing the highly viscous fluid. (4) The vibration isolating device according to claim 2 or 3, wherein the movable member is formed of an elastic body.