JPH07310775A - Vibration-proof device - Google Patents

Abstract

PURPOSE:To improve riding comfortableness of a vehicle by improving the performance to a harness. CONSTITUTION:An inner cylinder hardware 16 is disposed in an outer cylinder hardware 12, and the inner cylinder hardware 16 is connected to a car body. An elastic body 18 is extended between an intermediate cylinder 14 in the outer cylinder hardware 12 and the inner cylinder hardware 16. An insulator 22 to which an electrode plate 26 is stuck is fixed to the inner peripheral side of the outer cylinder hardware 12, and an insulator 24 to which an electrode plate 28 is stuck is made adhere to the outer peripheral side of the inner cylinder hardware 16. An electric viscous fluid E is enclosed in a liquid chamber 32 formed between the outer cylinder hardware 12 and the inner cylinder hardware 16. The electrode plate 26 is connected to a plus pole, and the electrode plate 28 is connected to the minus pole of the controller. The controller receives a detection signal from a sensor 54. When the voltage is applied from the controller while the voltage is controlled, an electric field is generated between the electrode plate 26 and the electrode plate 28.

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 whose characteristics such as spring constant can be changed. For example, a bush for a trailing arm and a bush for a suspension such as a radius rod or a tension rod arranged in a vehicle. It is also applicable as a substitute for a high-viscosity type member mount.

[0002]

2. Description of the Related Art Conventionally, a suspension pivot bush for elastically supporting a trailing arm for supporting a tire of a vehicle, for example, between a trailing arm and a vehicle body is arranged.

FIG. 7 shows the vicinity of a trailing arm to which the suspension pivot bush is attached, and a conventional suspension device will be described with reference to this figure.

As shown in FIG. 7, the front ends of a pair of trailing arms 116 are fixed to axle beams 114 having tires 112 at both ends. Bushings 118 are fixed to the pair of trailing arms 116 so that their axial directions are substantially perpendicular to the front-rear direction X of the vehicle body (not shown).

On the other hand, it has a damping property with respect to harshness, which means a shocking vibration that occurs when a protrusion passes over.
Due to the necessity of improving the harshness performance, various properties have been required for the springiness of these bushes 118 along the vehicle body front-rear direction.

That is, at the moment of passing the projection, it is desired that the dynamic transmissibility in the front-rear direction of the vehicle body is low, and damping is unnecessary, but the dynamic spring needs to be low. It needs to be hardened or damped. However, in the conventional bush, the characteristics cannot be changed according to the running conditions in this way, and the characteristics must be set so as to satisfy any one of the characteristics or an intermediate value between these characteristics. It was

[0007]

SUMMARY OF THE INVENTION In consideration of the above facts, an object of the present invention is to provide an anti-vibration device which improves the performance against harshness and improves the riding comfort of a vehicle.

[0008]

According to a first aspect of the present invention, there is provided a vibration isolator having a first mounting member connected to one of a vibration generating portion and a vibration receiving portion and a vibration detecting portion and a vibration receiving portion connected to the other. A second mounting member, an elastic body interposed between the first mounting member and the second mounting member, and mounted between the first mounting member and the second mounting member. And a liquid chamber in which an electrorheological fluid whose viscosity changes according to the strength of an electric field is enclosed, and a first mounting member which is installed on the first mounting member so as to face the liquid chamber. An electrode, a second electrode installed on the second mounting member so as to face the liquid chamber, and a vibration connected to and transmitted to at least one of the pair of electrodes. A control member for controlling the voltage applied to the pair of electrodes, That.

According to a second aspect of the present invention, there is provided a vibration isolator comprising: a first mounting member connected to one of the vibration generating section and the vibration receiving section; and a second mounting member connected to the other of the vibration generating section and the vibration receiving section. An elastic body interposed between the first mounting member and the second mounting member to be mounted, and an elastic body interposed between the first mounting member and the second mounting member. And a liquid chamber in which an electrorheological fluid whose viscosity changes according to the strength of an electric field is enclosed, a first electrode installed on the first mounting member so as to face the liquid chamber, and the liquid chamber A second electrode that is installed on the second mounting member so as to face the sensor, a sensor that detects vibration transmitted from the vibration generator side, and a signal that is connected to the pair of electrodes and that is a signal from the sensor. A control member for controlling the voltage applied to the pair of electrodes based on The features.

[0010]

The operation of the vibration isolator according to claim 1 will be described below.

When the vibration is transmitted from the vibration generating portion connected to any one of the mounting members, the elastic body is deformed, and the liquid chamber is expanded / contracted accordingly, and a flow occurs in the electrorheological fluid in the liquid chamber. The vibration is damped by the deformation of the elastic body and the flow of the electrorheological fluid, and it becomes difficult to transmit the vibration to the vibration receiving portion side.

In addition, when a sudden and large-amplitude vibration is transmitted, a voltage is not applied to the electrodes in advance, and the vibration is generated by the deformation of the elastic body and the flow of the electrorheological fluid as described above. Correspond.

Immediately after the vibration is transmitted, the control member applies a voltage to the pair of electrodes while controlling the voltage to apply an electric field to the electrorheological fluid sealed in the liquid chamber. As a result, the viscosity of the electrorheological fluid changes according to the magnitude of the applied electric field, and accordingly, the electrorheological fluid solidifies between the pair of electrodes, which impedes the flow of the electrorheological fluid in the liquid chamber. . Therefore, in this state, the dynamic spring coefficient increases and the damping becomes high, so that the vibration remaining after the vibration is transmitted is damped early.

For example, when the vibration damping device according to claim 1 is mounted on a vehicle, at the moment when the vehicle passes through a protrusion or a step on the road surface, the voltage is not applied to the electrodes in advance as described above. The elastic body is deformed and the electrorheological fluid flows to respond to this forced vibration.

Immediately after passing through the protrusions and the like, a voltage is applied to the pair of electrodes to apply an electric field to the electrorheological fluid sealed in the liquid chamber. As a result, the electrorheological fluid is solidified between the pair of electrodes, and the flow of the electrorheological fluid in the liquid chamber is hindered. Therefore, in this state, the dynamic spring coefficient of the vibration isolator becomes large and the vibration damping becomes high, and the free vibration remaining after the vibration is transmitted can be quickly damped.

As described above, the harshness can be dealt with and the riding comfort of the vehicle can be improved. The operation of the vibration isolator according to claim 2 will be described below.

According to the first aspect of the present invention, the sensor detects the vibration transmitted from the vibration generating portion side, and the control member controls the voltage based on the signal from the sensor and the pair of electrodes. Apply to.

Therefore, it is possible to apply the voltage to the pair of electrodes while controlling the voltage based on the vibration transmitted from the vibration generator side, so that the harshness can be dealt with more accurately.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which a vibration damping device according to the present invention is applied to a bush for a suspension device is shown in FIGS. 1 to 5, and this embodiment will be described based on these drawings.

As shown in FIGS. 1 and 2, the tire 42 to which the vibration from the road surface is transmitted is attached to the shock absorber 46.
On the base end side of the trailing arm 44 supported by and, a tubular bracket 45 is joined and fixed by welding. Then, the tire 42, the trailing arm 44, and the like constitute a vibration generating portion in which vibration is generated due to unevenness on the road surface.

Further, the outer peripheral side of the outer cylindrical metal fitting 12 which is the first mounting member formed in a cylindrical shape is tightly fitted and fixed to the bracket 45 fixed to the trailing arm 44. An inner tubular metal fitting 16 that is a second pipe-shaped mounting member is disposed inside the outer tubular metal fitting 12 that forms the outer frame of the bush 10 and is coaxial with the outer tubular metal fitting 12. ing. And this inner cylinder metal fitting 1
6 is connected to a part of the vehicle body 40, which is a vibration receiving portion, by a bolt or the like (not shown).

On the other hand, as shown in FIG. 3, a pair of intermediate cylinders 14 are press-fitted inside the outer cylinder fitting 12, and between the intermediate cylinder 14 and the inner cylinder fitting 16 the intermediate cylinder 14 and A pair of elastic bodies 18 formed by a rubber material or the like are vulcanized and adhered to the inner tubular metal member 16 and are arranged in a stretched manner.

Between the pair of intermediate cylinders 14 and at the upper and lower positions on the inner peripheral side of the outer cylinder fitting 12, as shown in FIGS. The pair of insulators 22 to which the electrode plate 26 which is the electrode of
It is fixed. Further, between the pair of elastic bodies 18 and on the outer peripheral side of the inner tubular metal member 16, an electrode plate 28 serving as a second electrode is attached at a position facing the electrode plate 26 with a predetermined gap. A pair of insulators 24 are adhered. Further, the space portion 34 formed between the side surfaces of the pair of elastic bodies 18 and interposed between the outer tubular metal fitting 12 and the inner tubular metal fitting 16 is a liquid chamber 32. An electrorheological fluid E is enclosed in the.

On the other hand, as shown in FIG. 3, the other end of the lead wire whose one end is connected to the electrode plate 26 is the positive pole of the controller 52 located outside the bush 10 which constitutes the main body of the vibration isolator. It is connected. Further, the other end of the lead wire whose one end is connected to the electrode plate 28 is connected to the minus pole of the controller 52. Therefore, this controller 5
When 2 serves as a control member and a voltage is applied from the controller 52 while controlling the voltage, an electric field is generated between the pair of electrode plates 26 and 28.

The controller 52 is driven by a vehicle power supply and is adapted to receive a detection signal from a sensor 54 which is attached to the trailing arm 44 and can detect acceleration or amplitude. Therefore, the sensor 54 can detect the amplitude of the tire 42 or the acceleration applied to the tire 42 through the trailing arm 44, and determine whether the controller 52 is normal vibration or vibration due to harshness.

In this embodiment, the following is used as the electrorheological fluid E.

That is, this electrorheological fluid E is 5 to 6
Carbon / hydrogen atomic ratio (C / H ratio) of 0% by weight is 1.2 to 5
A fluid composed of the carbonaceous fine powder and 95 to 40% by weight of silicone oil can be applied. The electrorheological fluid E has the viscosity of ordinary hydraulic fluid when the electrodes are not energized, and has the characteristic that the viscosity changes according to the strength of the electric field to become hard when energized.

Therefore, by energizing the electrode plate 26 and the electrode plate 28, the viscosity of the electrorheological fluid E is increased at the central portion C of the bush 10 in the left-right direction in FIG. 4, or in some cases, this portion is solidified. As a result, the flow of the electrorheological fluid E in the liquid chamber 32 can be blocked.

Next, the operation of this embodiment will be described. When the vehicle travels, the vibration of the tire 42 due to the unevenness of the road surface causes the elastic body 18 to pass through the trailing arm 44 and the outer cylinder fitting 12.
Be transmitted to. The elastic body 18 acts as a main vibration absorber, and can absorb the vibration by the damping function based on the internal friction of the elastic body 18. Further, as the elastic body 18 is deformed, the liquid chamber 32 expands and contracts to cause the electrorheological fluid E in the liquid chamber 32 to flow, and the electrorheological fluid E vibrates due to the damping action based on the viscous resistance of the liquid flow. Is attenuated and the vehicle body 40
Vibration is difficult to be transmitted to the side.

That is, for example, when traveling at high speed, the vibration damping effect is obtained by the deformation of the elastic body 18 and the flow of the electrorheological fluid E in the liquid chamber 32.

On the other hand, as shown in FIG. 1, when a sudden vibration with a large amplitude is transmitted, such as at the moment when the vehicle passes through the projection 80 on the road surface, the pair of electrodes 2 is previously set.
Since the voltage is not applied to 6 and 28, the deformation of the elastic body 18 and the flow of the electrorheological fluid E can cope with the forcibly applied vibration. Therefore, as shown in FIG. 5, in comparison with the conventional bush shown by the solid line,
The amplitude of the bush 10 of this embodiment shown by the dotted line is reduced by the length L.

Then, the sensor 54 detects the vibration of the trailing arm 44, and immediately after the passage of the protrusion 80.
After 2 to 0.3 seconds (shown as t in FIG. 5), the controller 52 applies a voltage to the pair of electrodes 26 and 28 while controlling the voltage based on the signal from the sensor 54, and the electrorheological fluid is generated. An electric field is applied to E. As a result, the electrorheological fluid E is solidified between the pair of electrodes 26, 28 accordingly,
The flow of the electrorheological fluid E in the liquid chamber 32 is hindered.

Therefore, in this state, the dynamic spring coefficient of the bush 10 increases and the damping becomes high, and the free vibration remaining after the vibration is transmitted can be quickly damped as shown in FIG. Becomes

Further, in the present embodiment, the voltage can be applied to the pair of electrodes 26, 28 while controlling the magnitude of the voltage value based on the magnitude of the vibration amplitude of the trailing arm 44. It becomes possible to deal with harshness more accurately.

As described above, it is possible to cope with harshness and improve the riding comfort of the vehicle. Along with this, it is possible to reduce shocking vibration with low power consumption that only causes an electric field effect.

Next, a second embodiment in which the vibration damping device according to the present invention is applied to a bush for a suspension device is shown in FIG. 6, and this embodiment will be described based on this drawing. The same members as those in the first embodiment are designated by the same reference numerals, and the duplicated description will be omitted.

Similar to the first embodiment, the bush 10 has an outer tubular metal member 12, an inner tubular metal member 16 and an elastic body 18, but a pair of insulators 2 to which an electrode plate 26 is attached.
Instead of 2, the same annular insulator 62 in which an electrode ring 66 formed in an annular shape is attached to the inner peripheral side is fitted and arranged on the inner peripheral side of the outer tubular metal fitting 12.

Further, instead of the pair of insulators 24 to which the electrode plate 28 is attached, a ring-shaped electrode ring 68 is formed.
A ring-shaped insulator 64, which is attached to the outer peripheral side, is fitted and arranged on the outer peripheral side of the inner tubular member 16.

Therefore, this embodiment not only exhibits the same operation and effect as the first embodiment, but also has an annular shape instead of the electrode plates 26 and 28 attached to the pair of insulators 22 and 24, respectively. Since the formed electrode rings 66 and 68 are used, an electric field is applied to the entire liquid chamber 32. Therefore, the electrorheological fluid E as a whole can be solidified, and a further effect can be obtained.

Further, instead of the electrode plates 26 and 28 attached to the pair of insulators 22 and 24, one electrode ring 66 and 68 is used, respectively, so that the number of parts is reduced and the parts are reduced. This has the effect of reducing costs.

In each of the above embodiments, the inner tubular metal member 16 of the bush 10 is connected to the vehicle body 40 which serves as a vibration receiving portion,
The outer cylinder metal fitting 1 is attached to the trailing arm 44 which is a vibration generating portion.
Although the two are connected to each other, the outer cylinder fitting 12 may be connected to the vehicle body 40 and the inner cylinder fitting 16 may be connected to the trailing arm 44.

Further, the bush 10 of this embodiment may be attached to another type of arm or the like instead of the trailing arm. Needless to say, the same action and effect as described above can be obtained even if the semi-trailing arm type is attached.

On the other hand, the outer tubular metal member 12 and the inner tubular metal member 16,
An insulator insulates the electrode plates 26, 28 and the electrode rings 66, 68 from each other. As a material of this insulator, synthetic resin, ceramics or the like can be considered.

In the above embodiment, the pair of electrodes are connected to the controller, respectively, but one electrode may be grounded so that only the other electrode is connected to the controller 52. In addition, sensor 5
4 may also be attached to the axle supporting the tire 42 or the bush 10 itself instead of being attached to the trailing arm 44.

In the above embodiment, the operation when passing through the projection on the road surface has been described as an example. However, even when the vehicle passes through a step on the road surface or a rough road surface, it is similar to the embodiment. Will work.

Further, the shapes of the outer cylinder fitting, the inner cylinder fitting, the elastic body and the like are not limited to those of the embodiment.

[0047]

As described above, the anti-vibration device of the present invention has the excellent effect of improving the harshness and improving the riding comfort of the vehicle.

[Brief description of drawings]

FIG. 1 is a partial side sectional view of a vehicle in which a bush according to a first embodiment of the present invention is adopted.

FIG. 2 is a schematic configuration diagram of a bush according to the first embodiment of the present invention.

FIG. 3 is a partial side sectional view of the bush according to the first embodiment of the present invention.

4 is a cross-sectional view taken along the line 4-4 of FIG.

FIG. 5 is a diagram showing vibration damping characteristics of the bush according to the first embodiment of the present invention, and is a diagram showing vibration of the wheel center of the tire or the bush in the front-rear direction of the vehicle.

6 is a cross-sectional view of the bush according to the second embodiment of the present invention, which is a cross-sectional view corresponding to the line 4-4 of FIG.

FIG. 7 is a perspective view showing a suspension device according to a conventional technique.

[Explanation of symbols]

 10 Bush (Vibration Isolator) 12 Outer Cylinder Metal Fitting (First Mounting Member) 14 Elastic Body 16 Inner Cylinder Metal Fitting (Second Mounting Member) 26 Electrode Plate (First Electrode) 28 Electrode Plate (Second Electrode) 32 liquid chamber 52 controller (control member) 54 sensor 66 electrode ring (first electrode) 68 electrode ring (second electrode)

Claims (2)

[Claims] 1. A first mounting member connected to one of the vibration generating portion and the vibration receiving portion, a second mounting member connected to the other of the vibration generating portion and the vibration receiving portion, and the first mounting member. An elastic body interposed between a member and the second attachment member to be attached, and an elastic body interposed between the first attachment member and the second attachment member and depending on the strength of the electric field. A liquid chamber in which an electrorheological fluid whose viscosity changes is sealed, a first electrode installed on the first mounting member to face the liquid chamber, and a first electrode to face the liquid chamber. A second electrode installed on the second mounting member, and a control member connected to at least one of the pair of electrodes and controlling a voltage applied to the pair of electrodes according to the type of vibration transmitted. An anti-vibration device comprising: 2. A first mounting member connected to one of the vibration generating portion and the vibration receiving portion, a second mounting member connected to the other of the vibration generating portion and the vibration receiving portion, and the first mounting member. An elastic body interposed between a member and the second attachment member to be attached, and an elastic body interposed between the first attachment member and the second attachment member and depending on the strength of the electric field. A liquid chamber in which an electrorheological fluid whose viscosity changes is sealed, a first electrode installed on the first mounting member to face the liquid chamber, and a first electrode to face the liquid chamber. A second electrode installed on the second mounting member, a sensor for detecting vibration transmitted from the vibration generator side, and a pair of electrodes connected to the pair of electrodes and based on a signal from the sensor. A vibration isolator, comprising: a control member that controls the applied voltage. .