JPH10299820A - Vibration isolating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently attenuate vibration inputted from all of directions. SOLUTION: Paired stopper metal fittings 20 are disposed at the center part in the axial direction of an inner cylinder metal fitting 14 arranged in the inner side of an outer cylinder metal fitting 12. An elastic body 16 is interposed between the inner cylinder fitting 14 and the outer cylinder fitting 12. Pocket parts 22 are formed at the connection parts 16A of the elastic body 16, and paired diaphragms 24 are formed while corresponding to the aforesaid pocket parts. Spaces the inner wall surfaces of which are formed by the opening recessed parts 16C and the like, are turned out to be paired liquid chambers 26A and 26B, and a space the inner wall surface of which is formed out of the pocket parts 22 and the like, is turned out to be an air chamber 28. A gap between the groove part 18A of an intermediate cylinder 18 and the outer cylinder fitting, is formed into a first orifice 30 which communicates between a pair of liquid chambers 26A, 26B. And a gap between each stopper fitting 20 projected out to the outer cylinder fitting 12 side and the outer cylinder fitting 12, is formed into a second orifice 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration device for absorbing vibration from a vibration generator, and is applicable to, for example, automobiles, general industrial machines, and the like.

[0002]

2. Description of the Related Art For example, a vibration isolator as a bush is disposed between a wheel serving as a vibration generating unit and a vehicle body serving as a vibration receiving unit. Therefore, the vehicle has a structure in which the vibration generated between the road surface and the wheels is absorbed by the vibration isolator and is prevented from being transmitted to the vehicle body.

More specifically, as shown in FIGS. 5 and 6, a rubber elastic body 114, a pair of liquid chambers 116A and 116B, and a pair of these liquid chambers are provided inside an outer cylinder 112 as shown in FIGS. Orifice 1 connecting 116A and 116B
18 is known. When the vehicle travels and the vibration is generated, the vibration is absorbed by the vibration damping function of the elastic body 114 and the liquid column resonance of the liquid in the orifice 118 connecting the pair of liquid chambers 116A and 116B. Thus, the transmission of the vibration is prevented by attenuating the vibration or reducing the dynamic spring constant.

[0004]

However, in the above-described vibration isolator, the direction in which vibration can be absorbed by the orifice 118 is only the X direction, and the vibration input to the vibration isolator from multiple directions is sufficiently reduced. Could not.

The present invention has been made in view of the above circumstances, and has as its object to provide a vibration damping device capable of sufficiently reducing vibrations input from multiple directions.

[0006]

According to a first aspect of the present invention, there is provided an anti-vibration device comprising: a cylindrical outer cylinder connected to one of a vibration generator and a vibration receiver; An inner cylinder connected and arranged inside the outer cylinder, and an elastic body disposed between the outer cylinder and the inner cylinder so as to connect between the outer cylinder and the inner cylinder and having a concave portion in part; A pair of liquid chambers that are bisected by the elastic body, a part of the inner wall is formed by the elastic body, and the liquid is sealed therein; a first orifice communicating between the pair of liquid chambers; A thin portion disposed between at least one of the liquid chambers and the concave portion of the elastic body and formed as a thin elastic body, and a thin chamber formed in the pair of liquid chambers on the side where at least the thin portion is disposed and A second orifice that allows the liquid to flow in the liquid chamber. To.

According to a second aspect of the present invention, in the vibration isolator of the first aspect, a convex portion protruding toward the outer cylinder is provided on the inner cylinder, and the second portion is formed by a gap between the convex portion and the outer cylinder. An orifice is formed.

The operation of the vibration isolator according to the first aspect will be described below. Since the elastic body connects the outer cylinder and the inner cylinder, and the inner cylinder or the outer cylinder is connected to the vibration generator, when vibration is transmitted from the vibration generator to the inner cylinder or the outer cylinder, the elastic body The body is deformed, and as a result, the vibration is attenuated by the deformation of the elastic body, and the vibration is hardly transmitted to the vibration receiving portion connected to the outer cylinder or the inner cylinder.

Further, the liquid is sealed in a pair of liquid chambers, each of which is bisected by an elastic body and a part of the inner wall is formed by the elastic body. And the thin part which is thinned and formed in the elastic body is arranged between at least one of the pair of liquid chambers and the concave portion provided in the elastic body.

[0010] Further, a first orifice communicates between the pair of liquid chambers, and a second orifice is formed in the liquid chamber on the side where at least the thin portion is disposed in the pair of liquid chambers, and the second orifice is formed in the liquid chamber. To allow the liquid to flow.

Therefore, when vibration is input along the direction in which the pair of liquid chambers are arranged, the pair of liquid chambers expand and contract with the deformation of the elastic body, and the vibration occurs due to the liquid column resonance in the first orifice. Therefore, vibration is attenuated not only by deformation of the elastic body but also by a change in the pressure of the liquid and the like, and the vibration is more difficult to be transmitted to the vibration receiving portion side.

Further, when vibration is input along a direction orthogonal to the direction in which the pair of liquid chambers are arranged, the liquid column resonance of the liquid in the second orifice formed in at least one of the pair of liquid chambers. As a result, the dynamic spring constant is reduced, and the vibration is attenuated not only by the deformation of the elastic body but also by the pressure change of the liquid and the like, and the vibration is more difficult to be transmitted to the vibration receiving portion side.

As described above, the vibration isolator according to the present invention can sufficiently reduce vibrations input from multiple directions.

The operation of the vibration isolator according to claim 2 will be described below. The present invention has the same configuration as that of the first aspect and operates similarly. However, the present invention has a configuration in which a convex portion protruding toward the outer cylinder is provided on the inner cylinder, and the second orifice is formed by a gap between the convex portion and the outer cylinder. For this reason, according to the configuration of the present invention, the second orifice can be formed without difficulty in the liquid chamber.

The frequency of vibration at which the dynamic spring constant is reduced may be changed by changing the amount of clearance between the convex portion and the outer cylinder, or by changing the thickness of the thin portion separating the concave portion and the liquid chamber. It can be adjusted by changing the hardness of the thin part.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 4 show a vibration isolator according to an embodiment of the present invention, and the present embodiment will be described with reference to these drawings.

As shown in FIGS. 1 and 2, an anti-vibration device 10 according to the present embodiment includes an outer cylindrical metal fitting 12 formed into a cylindrical shape.
Is provided as an outer frame, and the outer cylinder fitting 12 is fitted to the vehicle body (not shown) of the automobile as a vibration receiving portion, and the outer cylinder fitting 12 is connected to the vehicle body.

Inside the outer cylinder 12, an inner cylinder 14 formed in a tubular shape is disposed so as to be parallel to the axis of the outer cylinder 12. Then, a bolt (not shown) is screwed into the inner cylinder fitting 14, and the inner cylinder fitting 14 and a wheel (not shown) serving as a vibration generating unit are connected.

Further, a pair of stoppers 20 as a pair of protrusions are formed at the center of the inner cylinder 14 in the axial direction so as to protrude in the X direction which is the left-right direction of the inner cylinder 14 in FIG. , Which are welded or the like to the inner cylinder 14, and the stoppers 20 serve as stoppers for suppressing excessive displacement of the inner cylinder 14 in the X direction which is the main vibration direction of the vibration isolator 10. .

On the other hand, the inner cylindrical fitting 14 and the outer cylindrical fitting 12
As shown in FIGS. 3 and 4, a pair of flange portions 16 </ b> B protruding along the inner peripheral surface of the outer cylinder fitting 12 while being vulcanized and bonded to the inner cylinder fitting 14 as shown in FIGS. The elastic body 16 made of rubber is provided. As shown in FIG. 1, a pair of flanges 16 </ b> B extending from the periphery of the inner cylinder 14 to the inner peripheral surface of the outer cylinder 12 along a direction intersecting the direction in which the stopper 20 protrudes. Is formed as a part of the elastic body 16. And this elastic body 16 is a pair of stopper fittings 2.
It also covers around 0.

Therefore, each of the pair of flange portions 16B
In the portion of the elastic body 16 between the connecting portion 16A and the connecting portion 16A, a pair of recessed openings 16C is formed.

Further, one of the pair of connecting portions 16A is formed with a pocket portion 22 which is a concave portion, and correspondingly, the connecting portion 16A is formed with a pair of thin portions. Thus, a pair of diaphragms 24 are formed.

As shown in FIGS. 1 and 4, at the position close to the outer peripheral side of the elastic body 16, there is formed an opening formed in a thick, cylindrical shape and opening a portion facing the pair of stopper fittings 20, respectively. An intermediate cylinder 18 having a pair of parts 18B is arranged by vulcanization bonding, and as shown in FIG. 3, a groove extending along the circumferential direction is formed at an axially central portion on the outer peripheral surface side of the intermediate cylinder 18. 18A are formed.

The intermediate cylinder 18 is fitted to the outer cylinder fitting 12 and they are fixed to each other. The outer peripheral side of a portion corresponding to the pair of flange portions 16B of the intermediate cylinder 18 and the outer cylinder fitting 12 The O-rings 34 are disposed between the two, and the O-rings 34 seal the fitting portions therebetween.

As described above, the opening concave portion 16C of the elastic body 16 is sealed by the outer cylindrical fitting 12, and the pair of spaces in which the inner wall surface is formed by the opening concave portion 16C of the elastic body 16, the outer cylindrical fitting 12, and the like are elastic. A right liquid chamber 26A and a left liquid chamber 26B are formed by the body 16 into a pair of liquid chambers. Then, a liquid such as water, oil or the like is supplied to these right liquid chambers 26A.
And in the left liquid chamber 26B. Furthermore, the pocket portion 22 is also sealed by the outer tube fitting 12, and the space in which the inner wall surface is formed by the pocket portion 22, the outer tube fitting 12, and the like,
It becomes the air chamber 28.

A first orifice 30 is formed as a restriction passage in a gap between the groove 18A of the intermediate cylinder 18 and the inner peripheral surface of the outer cylinder fitting 12, and the first orifice 30 is formed in the right liquid chamber. 26A and the left liquid chamber 26B are connected so as to communicate with each other.

Further, a gap between a pair of stopper fittings 20 provided on the inner cylinder fitting 14 and protruding toward the outer cylinder fitting 12 and the outer cylinder fitting 12 forms a second restricted passage.
Orifices 32 are respectively formed. That is, as shown in FIG. 1, a second orifice 32 is formed in each of the pair of liquid chambers 26A and 26B, and these second orifices 32 allow liquid to flow in the pair of liquid chambers 26A and 26B, respectively. Make it flowable.

Next, the operation of the present embodiment will be described. When the vibration of the wheel is transmitted to the inner cylinder 14, the elastic body 16 is deformed to attenuate the vibration, and the vibration transmitted to the vehicle body connected to the outer cylinder 12 is reduced.

The liquid is sealed in a pair of liquid chambers 26A and 26B, each of which is divided into two by the elastic body 16 and a part of the inner wall is formed by the elastic body 16, respectively. The thin diaphragm 24 formed in the elastic body 16 is disposed between the pair of liquid chambers 26A and 26B and the pocket portion 22 provided in the elastic body 16, respectively.

Further, the first orifice 30 communicates between the pair of liquid chambers 26A and 26B, and the pair of liquid chambers 26A and 26B
A second orifice 32 is formed in each of the liquid chambers 26B, and the second orifice 32 enables liquid to flow in the pair of liquid chambers 26A and 26B.

Therefore, when vibration is input in the X direction, which is the direction in which the pair of liquid chambers 26A and 26B are arranged, the pair of liquid chambers 26A and 26B expand and contract with the deformation of the elastic body 16, respectively. Since vibration is suppressed by liquid column resonance in the first orifice 30, not only deformation of the elastic body 16 but also
Vibration is attenuated by the pressure change of the liquid and the viscous resistance, etc., and the vibration is more difficult to be transmitted to the vehicle body side.

When vibration is input in the Y direction, which is a direction orthogonal to the direction in which the pair of liquid chambers 26A and 26B are arranged, the second orifices 32 formed in the pair of liquid chambers 26A and 26B, respectively. The dynamic spring constant is reduced due to the liquid column resonance of the liquid inside, and the vibration is attenuated not only by the deformation of the elastic body 16 but also by the pressure change and the viscous resistance of the liquid, as in the above, resulting in high frequency vibration. It is difficult for the muffled sound and the like to be transmitted to the vehicle body. At this time, a pair of liquid chambers 26A,
Since a part of the partition wall of 6B is formed so that the diaphragm 24 can be elastically deformed, liquid column resonance surely occurs and the dynamic spring constant is reduced.

As described above, the vibration isolator 1 according to the present embodiment is described.
0 means that vibrations input from multiple directions can be sufficiently reduced.

In the present embodiment, the stopper 20 protruding toward the outer cylinder 12 is provided on the inner cylinder 14, and the second stopper is provided by the gap between the stopper 20 and the outer cylinder 12.
An orifice 32 is formed. For this reason, in the present embodiment, the second orifice 32 is
A and 26B can be formed without difficulty.

Further, the frequency of the vibration at which the dynamic spring constant is reduced can be changed by changing the amount of the gap between the stopper fitting 20 and the outer cylinder fitting 12, or by changing the pocket portion 22 and the liquid chambers 26A and 26A.
The adjustment can be made by changing the hardness of the diaphragm 24 by changing the thickness of the diaphragm 24 partitioning the diaphragm 24 from the 6B.

In the above embodiment, the pair of second orifices 32 is provided, but the second orifice 32 may be provided only in one of the pair of liquid chambers 26A and 26B. Outer cylinder fitting 1 forming the wall of air chamber 28
A through hole for communicating air may be formed in the portion 2 as needed.

Further, in the above embodiment, the outer cylinder fitting 12 is connected to the vehicle body side serving as the vibration receiving section, and the inner cylinder fitting 14 is connected to the wheel side serving as the vibration generating section. The configuration may be reversed.

On the other hand, in the embodiment, the purpose of the present invention is to prevent the vibration of the wheels. However, the anti-vibration device of the present invention can be used, for example, for an engine mounted on an automobile, a body mount, or other uses other than the automobile. Needless to say, the shape and dimensions of the elastic body and the like are not limited to those of the embodiment.

[0039]

As described above, the vibration isolator according to the present invention has an excellent effect that vibrations input from multiple directions can be sufficiently reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a vibration isolator according to an embodiment of the present invention.

FIG. 2 is a perspective view of a vibration isolator according to one embodiment of the present invention.

FIG. 3 is a sectional view taken along line 3-3 of the vibration isolator shown in FIG.

FIG. 4 is a sectional view taken along line 4-4 of the vibration isolator shown in FIG.

FIG. 5 is a sectional view of a conventional vibration isolator.

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration isolator 12 Outer tube fitting (outer tube) 14 Inner tube fitting (inner tube) 16 Elastic body 24 Diaphragm (thin part) 26A Right liquid chamber 26B Left liquid chamber 30 First orifice 32 Second orifice

Claims (2)

[Claims] A cylindrical outer cylinder connected to one of the vibration generator and the vibration receiver; an inner cylinder connected to the other of the vibration generator and the vibration receiver and arranged inside the outer cylinder; An elastic body provided between the outer cylinder and the inner cylinder so as to connect between the outer cylinder and the inner cylinder and having a recess in a part thereof; A pair of liquid chambers each formed and filled with a liquid, a first orifice communicating between the pair of liquid chambers, and a first orifice between the pair of liquid chambers and a concave portion of the elastic body. And a second orifice formed in the liquid chamber on the side where at least the thin part of the pair of liquid chambers is disposed and capable of flowing the liquid in the liquid chamber. An anti-vibration device characterized by having. 2. The vibration damping device according to claim 1, wherein a protrusion protruding toward the outer cylinder is provided on the inner cylinder, and a second orifice is formed by a gap between the protrusion and the outer cylinder.