JPH10331907A - Vibration isolator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb vibration in wide frequency regions. SOLUTION: A movable wall 24 is supported in a vertically movable manner under a passage forming member 28 via brackets 46, 48 and an elastically deformable elastic support member 50. The movable wall 24 constitutes a part of a diaphragm of a main liquid chamber 30. A diaphragm 54 is disposed under the movable wall 24. A space between the movable wall 24 and the diaphragm 54 is used as an auxiliary liquid chamber 56. The movable wall 24 constitutes a part of a partition wall of the auxiliary liquid chamber 56. An idle orifice 60 communicating between the main liquid chamber 30 and the auxiliary liquid chamber 56 is formed at the movable wall 24. A stator 67 having a coil 66 wound therearound is housed inside a groove 24C of the movable wall 24 in such a manner as to face a magnet 64 fixed inside the movable wall 24 with the space held therebetween. The base end of the stator 67 is supported by a support table 68.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration isolator for preventing transmission of vibration from a member that generates vibration, and is applicable to, for example, a case where transmission of vibration from an engine mounted on a vehicle is prevented. Things.

[0002]

2. Description of the Related Art For example, an anti-vibration device as an engine mount is disposed between an engine of a vehicle serving as a vibration generating portion and a vehicle body serving as a vibration receiving portion. There is known a structure that absorbs vibration and prevents vibration from being transmitted to the vehicle body.

That is, as an example of the vibration isolator, there is a structure in which a main liquid chamber and a sub liquid chamber are provided inside, and these liquid chambers are communicated with each other by a restriction passage serving as an orifice. When the mounted engine operates and generates vibration, the vibration is absorbed by the liquid column resonance of the liquid in the restriction passage communicating with the liquid chambers and the transmission of the vibration is stopped. I have.

[0004] On the other hand, the vibration frequency becomes wide with the wide operating state of the engine. Therefore, in recent years, anti-vibration devices that perform active control so as to maintain the anti-vibration characteristics even in each of such vibrations of a wide range of frequencies have been proposed in recent years.

[0005] As a conventional anti-vibration device for performing active control, a movable wall is provided as a partition of the main liquid chamber, and the movable wall is reciprocated in synchronization with the vibration by an actuator, so as to reciprocate the main liquid chamber. There is a structure that cancels a rise in internal pressure and prevents transmission of vibration.

[0006]

However, among the vibrations of the vehicle, the idle vibration generated in the engine at the time of idling is as follows.
Because the engine speed was reduced as much as possible, the vibration was large. For this reason, in the idling vibration region, the input of vibration from the engine becomes large, and the vibration control device having the above-described structure has a shortage of control force, resulting in an insufficient vibration control effect.

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 absorbing vibrations corresponding to vibrations of a wide frequency range including idle vibrations.

[0008]

According to a first aspect of the present invention, there is provided a vibration isolator which is connected to one of a vibration generator and a vibration receiver, and connected to the other of the vibration generator and the vibration receiver. A second mounting member, an elastic body disposed between the pair of mounting members, and a main liquid chamber in which a liquid is sealed using the elastic body as a part of the partition wall and the inner volume of the main liquid chamber changes due to deformation of the elastic body. A sub-liquid chamber in which a part of the partition is formed so as to be deformable and in which a liquid is sealed, another part of the partition of the main liquid chamber and another part of the partition of the sub-liquid chamber are integrally formed, and It has a movable wall provided with a restriction passage communicating between the liquid chamber and the sub liquid chamber, and an actuator that reciprocates the movable wall by magnetic force.

According to a second aspect of the present invention, there is provided an anti-vibration apparatus according to the first aspect, further comprising control means for operating the actuator and a sensor for detecting a waveform of the vibration, based on the waveform of the vibration detected by the sensor. The control means operates the actuator.

The operation of the vibration isolator according to claim 1 will be described below. When vibration is transmitted from the vibration generating unit connected to any of the attachment members, the elastic body is deformed and the vibration is attenuated by the elastic body. Due to the deformation of the elastic body, the inner volume of the main liquid chamber changes, and a part of the partition wall is deformed to the liquid in the restriction passage communicating between the sub liquid chamber and the main liquid chamber. A pressure change occurs, and the partition of the sub liquid chamber communicating with the main liquid chamber is deformed.

As a result, when the vibration is transmitted from the vibration generating section, the vibration is attenuated not only by the elastic body but also by the liquid in the restriction passage between the main liquid chamber and the sub liquid chamber, and the vibration is received. Vibration is hardly transmitted to the part side.

Further, when the frequency of the vibration from the vibration generating section changes, and the fixed restriction passage transmits, for example, idle vibration, which is a high-frequency vibration that cannot be reduced, the vibration is adjusted accordingly. The actuator reciprocates the movable wall integrally forming the other part of the partition of the main liquid chamber and the other part of the partition of the sub liquid chamber by magnetic force.

That is, in the idle vibration region, the movable wall integrally forming the other part of the partition of the main liquid chamber and the other part of the partition of the sub liquid chamber is driven by the actuator that generates the magnetic force, and Reciprocate so as to expand and contract the liquid chamber and the sub liquid chamber. Along with this, a large pressure difference is generated between the main liquid chamber and the sub liquid chamber, thereby increasing the amount of liquid flowing in the restriction passage connecting the main liquid chamber and the sub liquid chamber.

Thus, the liquid column resonance is positively caused by the liquid in the restriction passage, whereby the vibration can be absorbed corresponding to the vibration in the idle vibration region having a large amplitude.

That is, since the movable wall reciprocates in synchronization with the vibration, it is possible to reduce a vibration having a large amplitude such as an idle vibration, and accordingly, the vibration is appropriately absorbed in any vibration band. Will be.

The operation of the vibration isolator according to claim 2 will be described below. The present invention has the same function as the first embodiment. However, according to the present invention, there is provided a control means for operating the actuator and a sensor for detecting a waveform of the vibration, and the control means operates the actuator based on the waveform of the vibration detected by the sensor.

Therefore, the actuator is operated based on the waveform of the vibration detected by the sensor, so that the vibration can be more reliably absorbed.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an embodiment of a vibration isolator according to the present invention, and the present embodiment will be described with reference to these drawings.

As shown in FIG. 1 showing the present embodiment, a lower part of a vibration isolator 10 is mounted on a mounting bracket 1 as a first mounting member.
2 bottom 12A is formed, and under the bottom 12A,
Bolts 14 for connecting and fixing the vibration isolator 10 to a vehicle body (not shown) are implanted. A cylindrical part 12B is formed at the upper part of the mounting part 12 with a diameter larger than that of the bottom part 12A of the mounting part 12 by one step. Cylindrical metal fitting 16 formed in a cylindrical shape with the central part in the direction being one step narrower in diameter.
Is arranged.

That is, the intermediate cylindrical member 16 is arranged such that the cylindrical portion 12B of the mounting member 12 covers the entire outer peripheral side of the intermediate cylindrical member 16. And this cylindrical part 1
The upper end of 2 </ b> B is caulked to the upper end of the intermediate cylindrical member 16, and the intermediate cylindrical member 16 is joined to the mounting member 12.

On the inner peripheral surface of the upper part of the intermediate cylindrical fitting 16,
The lower side of the rubber-made elastic body 18 having a cylindrical shape is vulcanized and bonded, and the center of the upper side of the elastic body 18 is vulcanized and bonded to a top plate 20 serving as a second mounting member. A bolt 22 used for connecting an engine (not shown) projects upward from the center of the top plate fitting 20.

A ring-shaped passage forming member 28 is arranged below the elastic body 18 while being fitted inside the intermediate cylindrical fitting 16. A pair of ring-shaped brackets 46 and 48 fitted to the cylindrical portion 12B are fixed. The movable walls 24 formed in a disk shape are supported by the brackets 46 and 48 via elastic support members 50 made of rubber and capable of being elastically deformed.

As described above, the elastic body 18, the passage forming member 28
The space defined by the movable wall 24 constitutes a main liquid chamber 30, in which a liquid such as water or oil is sealed. Therefore, the elastic body 18, the passage forming member 28 and the movable wall 2
4 constitutes a partition wall of the main liquid chamber 30 in which the liquid is sealed.

On the other hand, as shown in FIG.
8 has a U-shape whose outer peripheral side is open, and a groove 38 is formed on the outer peripheral surface of the passage forming member 28 along the circumferential direction of the passage forming member 28.

The groove 38 and the inner peripheral surface of the intermediate cylindrical member 16 form a shake orifice 42 which is a restriction passage for absorbing shake vibration. One end of the shake orifice 42 has a hole passing through the passage forming member 28. The shake orifice 4 is connected to the main liquid chamber 30 at a portion 28A.
The other end of 2 is connected to the outer peripheral surface of the intermediate cylindrical member 16 by a hole 16A penetrating the intermediate cylindrical member 16.

A thin and elastically deformable rubber diaphragm 26 is vulcanized and adhered to a mounting piece 34 at a portion inside the cylindrical portion 12B of the mounting fitting 12 and corresponding to the intermediate cylindrical fitting 16. In, it is installed. The diaphragm 26 covers an outer peripheral side portion of the intermediate cylindrical fitting 16 including a portion corresponding to an opening end of the shake orifice 42.

For this reason, the space between the inner peripheral surface of the diaphragm 26 and the outer peripheral surface of the small-diameter portion of the intermediate cylindrical member 16 is connected to the auxiliary liquid communicating with the main liquid chamber 30 through the shake orifice 42. A liquid chamber 32 is provided.
The space between the outer peripheral surface of the cylindrical member 6 and the inner peripheral surface of the cylindrical portion 12B is an air chamber 40, and facilitates the deformation of the diaphragm 26.

On the other hand, a thin and elastically deformable rubber diaphragm 54 sandwiched between a bracket 48 and a bracket 52 located below the bracket 48 is disposed below the movable wall 24. The space between the movable wall 24 and the diaphragm 54 is a sub liquid chamber 56 in which liquid is sealed. Therefore, a part of the partition wall of the sub liquid chamber 56 in which the liquid is sealed is constituted by the movable wall 24. In addition, the bottom surface of the diaphragm 54 and the mounting
A space between the bottom portion 12A and the bottom portion 12A serves as an air chamber 57, which facilitates the deformation of the diaphragm 54.

Further, at the center of the movable wall 24, the movable wall 2
4, a large-diameter circular through-hole 58 extending in the axial direction is formed. This circular through-hole 58 is a restriction passage for idle vibration absorption communicating between the main liquid chamber 30 and the sub liquid chamber 56. A certain idle orifice 60 is formed.

The movable wall 24 is formed by an upper forming member 24A and a lower forming member 24B each having an L-shaped cross section.
Is sealed. A groove 24C is formed in a ring shape on the outer peripheral side of the movable wall 24, and a plurality of magnets 64 are bonded and fixed to the inner surface of the groove 24C. A stator 67 around which a coil 66 is wound is disposed in the groove 24C so as to face the magnet 64 with a space interposed therebetween, and the base end of the stator 67 is formed on the cylindrical portion 12B of the mounting bracket 12. It is supported by a ring-shaped support base 68 fitted on the inner peripheral surface.

As described above, the actuator 44 is constituted by the magnet 64, the coil 66, the stator 67, the support 68 and the like.

On the other hand, the coil 66 is connected to a control circuit 70 which is a control means for judging the driving condition of the vehicle and turning on / off the applied voltage. The control circuit 70 is driven by a vehicle power supply and receives detection signals from at least a vehicle speed sensor 72 and an engine speed sensor 74 for determining a driving state of the vehicle, and can determine a vibration state based on the vehicle speed and the engine speed. ing. That is, the control circuit 70
Can determine not only the occurrence of idle vibration, the occurrence of shake vibration, or the occurrence of muffled sound, but also the state of the waveform such as the amplitude and cycle of the vibration.

As described above, the control circuit 70 controls the energization of the coil 44 of the actuator 44 and the stop of the energization. Therefore, a magnetic force can be generated by energizing the coil 66 at an optimal timing within one cycle of the vibration, and this magnetic force interacts with the magnetic force of the magnet 64 to reciprocate the movable wall 24 in the vertical direction. Since the movable wall 24 can reciprocate, the vibration can be absorbed.

Next, the operation of the present embodiment will be described. When the engine mounted on the top plate 20 operates, vibration of the engine is transmitted to the elastic body 18 via the top plate 20. The elastic body 18 acts as a vibration absorbing body, and can absorb vibration by a vibration damping function based on internal friction of the elastic body 18.

Further, with the deformation of the elastic body 18,
The sub-liquid chamber 32 in which the inner volume of the main liquid chamber 30 changes and a part of the partition wall is formed so as to be deformable by the diaphragms 26 and 54,
Orifice 4 which communicates between 56 and the main liquid chamber 30
A pressure change occurs in the liquid in 2, 60, and the diaphragm 2
6, 54 are deformed.

As a result, when the vibration from the engine side is transmitted, not only the elastic body 18 but also the main liquid chamber 30 and the sub liquid chamber 3
Vibration is attenuated by viscous resistance of the flow of the liquid in the orifices 42, 60 between the second and 56, and the damping action based on the liquid column resonance, and the vibration is hardly transmitted to the vehicle body side.

The movable wall 24, which integrally forms a part of the partition of the main liquid chamber 30 and a part of the partition of the sub liquid chamber 56,
An actuator 44 drives the movable wall 24 by a magnetic force so that the liquid flows positively through an idle orifice 60 provided on the movable wall 24 by an elastic support member 50 so as to be able to elastically deform. As a result of reciprocating the wall 24, the following operation is performed.

The specific operation will be described below. For example, when the vehicle runs at low speed, shake vibration (less than 15 Hz) occurs. The control circuit 70 determines from the vehicle speed sensor 72 and the engine speed sensor 74 that shake vibration has occurred, and does not apply a voltage to the coil 66 of the actuator 44. As a result, the liquid vigorously moves back and forth in the shake orifice 42 and receives a passage resistance or resonates with the liquid column, thereby absorbing the shake vibration.

On the other hand, for example, when the vehicle stops, the engine is idling and idle vibration (20 to 40 Hz) having a high vibration frequency and a large amplitude is generated. In this case, the shake orifice 42 becomes clogged,
At this time, the control circuit 70 determines from the vehicle speed sensor 72 and the engine speed sensor 74 that idle vibration has occurred, and controls the actuator 44 so that the movable wall 24 moves up and down in the opposite phase to the waveform of the vibration by the magnetic force. The control circuit 70 applies a voltage to the coil 66.

That is, in the idling vibration region, the main liquid chamber 3
The movable wall 24, which integrally forms a part of the partition wall of the sub liquid chamber 56 and a part of the partition wall of the sub liquid chamber 56, has
4, the main liquid chamber 30 and the sub liquid chamber 56 are reciprocated so as to expand and contract, and a large pressure difference is generated between the main liquid chamber 30 and the sub liquid chamber 56. To increase the amount of liquid flowing through the idle orifice 60 that connects between the two.

Specifically, as shown in FIG. 2, at the moment when the engine vibrates and moves the top plate 20 in the direction of arrow A, the movable wall 24 is moved in the direction of arrow B opposite thereto. A voltage is applied to the coil 66, and as shown in FIG. 3, at the moment when the engine vibrates and moves the top plate 20 in the direction of arrow B, the movable wall 24 is moved in the direction of arrow A opposite thereto. A voltage is applied to the coil 66.

Thus, the liquid is positively moved between the main liquid chamber 30 and the sub liquid chamber 56 via the idle orifice 60, and the liquid actively generates liquid column resonance in the idle orifice 60. , The dynamic spring constant is reduced,
Vibration can be absorbed in response to vibration in an idle vibration region having a large amplitude.

On the other hand, for example, when the vehicle runs at high speed, a muffled sound (40 or more) having a higher vibration frequency is generated.
In this case, the shake orifice 42 and the idle orifice 60 are in a clogged state.
0 indicates that the muffled sound is generated by the vehicle speed sensor 72 and the engine speed sensor 74, and the actuator 4
A voltage is applied to the fourth coil 66.

As a result, the operation of canceling the internal pressure of the main liquid chamber 30 is performed in the usual same phase, contrary to the above-mentioned idle vibration.

Specifically, as shown in FIG. 4, the moment the engine vibrates and moves the top plate 20 in the direction of arrow A, the movable wall 24 is moved in the direction of arrow A in the same direction. When the engine vibrates and moves the top plate 20 in the direction of arrow B as shown in FIG. 5, the movable wall 24 is moved in the direction of arrow B in the same direction as shown in FIG. Then, a voltage is applied to the coil 66.

As a result, since the internal pressure of the main liquid chamber 30 does not increase, the vibration can be absorbed in response to the vibration in the muffled sound region.

As described above, the movable wall 24 reciprocates in synchronization with the cycle of the vibration, and the vibration such as the idle vibration and the muffled sound is reduced, whereby the vibration is appropriately absorbed at any frequency. That is, the characteristics of the vibration isolator 10 can be changed, and the vibration can be absorbed over a wide frequency range.

In the above embodiment, two sub-liquid chambers and two restriction passages are provided, but one sub-liquid chamber and one restriction passage may be provided. Further, in the above-described embodiment, the sensors for detecting the vibration waveform are the vehicle speed sensor 72 and the engine speed sensor 74.
A vibration sensor may be employed.

Furthermore, in the above embodiment, the mounting bracket 12 as the first mounting member is mounted on the vehicle body, and the top plate 20 as the second mounting member is mounted on the engine. It may be.

In the above embodiment, the purpose of the present invention is to dampen an engine mounted on a vehicle. Needless to say, the damping device of the present invention can be used for other purposes.
Further, the shape and the like are not limited to those of the embodiment.

[0051]

As described above, the vibration isolator according to the present invention can absorb vibrations corresponding to vibrations of a wide range of frequencies including idle vibrations.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of one embodiment of the vibration isolator according to the present invention, showing a state in which a top plate is moved in the direction of arrow A when idle vibration occurs.

FIG. 3 is a cross-sectional view of one embodiment of the vibration isolator according to the present invention, showing a state in which a top plate is moved in the direction of arrow B when idle vibration occurs.

FIG. 4 is a cross-sectional view of one embodiment of the vibration damping device according to the present invention, showing a state in which a top plate is moved in the direction of arrow A when a muffled sound is generated.

FIG. 5 is a cross-sectional view of an embodiment of the vibration isolator according to the present invention, showing a state in which a top plate is moved in the direction of arrow B when a muffled sound is generated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration isolator 12 Mounting bracket (first mounting member) 18 Elastic body 20 Top plate bracket (second mounting member) 24 Movable wall 30 Main liquid chamber 44 Actuator 56 Secondary liquid chamber

Claims (2)

[Claims] A first mounting member connected to one of the vibration generating section and the vibration receiving section; a second mounting member connected to the other of the vibration generating section and the vibration receiving section; and a pair of these mounting members. An elastic body disposed between the main body and a main liquid chamber in which a liquid is sealed with the elastic body as a part of a partition and the internal volume changes due to deformation of the elastic body; and a liquid formed by a part of the partition being deformable. And the other part of the partition of the main liquid chamber and the other part of the partition of the sub liquid chamber are integrally formed, and the communication between the main liquid chamber and the sub liquid chamber is restricted. A vibration isolator comprising: a movable wall provided with a passage; and an actuator that reciprocates the movable wall by magnetic force. 2. The apparatus according to claim 1, further comprising control means for operating the actuator and a sensor for detecting a waveform of the vibration, wherein the control means operates the actuator based on the waveform of the vibration detected by the sensor. Anti-vibration device.