JPH11166580A - Vibration control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a vibration control characteristic while reducing the volume of an air chamber. SOLUTION: An intermediate cylinder 18 is fitted into an outer cylinder fitting 16, and an elastic body 20 is vulcanization-bonded to the intermediate cylinder 18. Space between a recessed part 26 of the elastic body 20 and a partition member 30 is made one pressure receiving liquid chamber 34, and space between a recessed part 24 of the elastic body 20 and the inner peripheral surface of the outer cylinder fitting 16 is made the other pressure receiving liquid chamber 32. A pair of pressure receiving liquid chambers 32, 34 are communicated with each other by a first limiting passage 56. An auxiliary liquid chamber 48 communicated with the pressure receiving liquid chamber 32 by a second limiting passage 58 is provided at the partition member 30. Space between the inner peripheral surface of the outer cylinder fitting 16 and a diaphragm 50 is made an air chamber 52, and the diaphragm 50 can be deformed by the air chamber 52. A selector valve 72 is connected to the air chamber 52, and an intake manifold 74 is connected to the selector valve 72.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a general industrial machine,
The present invention relates to a vibration isolator used for an engine mount or the like of an automobile, and more particularly to a liquid filled type vibration isolator.

[0002]

2. Description of the Related Art Conventionally, it is known that a vibration isolator as an engine mount is provided between an engine of a vehicle and a vehicle body. In recent years, a liquid-filled type vibration damping device having a high vibration damping effect has been proposed as one type of this vibration damping device. An example of this is shown in FIGS. 7 and 8, and based on these figures, a conventional vibration damping device will be described below. The device will be described.

As shown in FIGS. 7 and 8, a main rubber 106 is hung between an inner cylinder 102 and an intermediate cylinder 104 of the liquid-filled type vibration damping device 100, and the intermediate rubber is inserted into an outer cylinder 108. The tube 104 is fixed by squeezing the outer tube 108.

The vibration isolator 100 has a pressure-receiving liquid chamber 110. The pressure-receiving liquid chamber 110 is provided with a pair of sub-liquids on the opposite side of the inner cylinder 102 through orifices 112A and 112B as restriction passages. The chambers 114A and 114B communicate with each other. Then, the pair of sub liquid chambers 114A,
Diaphragms 116A, 116B so as to cover 114B.
Are respectively vulcanized and bonded to form air chambers 118A and 118B.
And the sub liquid chambers 114A and 114B.

[0005] Further, the vibration isolator 100 is, for example,
The inner cylinder 102 is connected to an automobile engine, and the outer cylinder 108 is connected to an automobile body. Here, when the vibration of the engine is input to the vibration isolator 100 and the inner cylinder 102 and the outer cylinder 108 are relatively displaced in the radial direction (vertical direction in FIGS. 7 and 8), the pressure receiving liquid chamber 110 expands and contracts, The diaphragms 116A and 116B of the sub liquid chambers 114A and 114B are elastically deformed by the pressure change of the liquid chamber 110, and the sub liquid chamber 114
A, 114B, orifices 112A, 11B
The liquid flows back and forth in 2B, and a damping force is generated.

That is, the pressure receiving liquid chamber 110 and the auxiliary liquid chamber 114
A fluid flow is generated by the pressure difference between A and 114B, and a damping force is generated.

[0007]

However, in the above-described vibration damping device 100, when the inner cylinder 102 moves to the pressure receiving liquid chamber 110 side, the liquid amount corresponding to the volume fluctuation of the pressure receiving liquid chamber 110 is changed to the diaphragm 116A. , 116B must be absorbed by the side of the pair of auxiliary liquid chambers 114A, 114B, so that the volume of the air chambers 118A, 118B must be increased by the space taking into account the expansion of the diaphragms 116A, 116B.

[0008] The pressure of the main rubber 106 to press the liquid in the pressure receiving liquid chamber 110 and the pressure of the diaphragms 116A, 116B
Since the liquid flows due to a pressure difference from the tension when the air chambers expand toward the air chambers 118A and 118B, if the air chambers 118A and 118B are reduced, the magnitude of the resonance depends on the shape of the main rubber 106 and the like. And the vibration-proof characteristics may be insufficient.

An object of the present invention is to provide an anti-vibration device having improved anti-vibration characteristics while reducing the volume of an air chamber in consideration of the above fact.

[0010]

According to a first aspect of the present invention, there is provided a vibration isolator connected to one of a vibration generator and a vibration receiver and an outer cylinder connected to the other of the vibration generator and the vibration receiver. An inner cylinder, an elastic body that is provided between the inner cylinder and the outer cylinder, connects the inner cylinder and the outer cylinder, and is deformed when vibration occurs. A pair of pressure-receiving liquid chambers arranged and communicated with each other and filled with liquid, a sub-liquid chamber communicated with any one of the pair of pressure-receiving liquid chambers through a restriction passage, and a sub-liquid chamber A diaphragm formed so that a part of the partition wall can be elastically deformed, an air chamber disposed opposite to the sub-liquid chamber with the diaphragm interposed therebetween, an air chamber and a negative pressure source connected to the negative pressure source. Between a deformable state and an undeformable state by opening and closing the flow path to the source A valve that can switch the state of Iyafuramu, characterized by comprising a.

According to a second aspect of the present invention, in the vibration isolator of the first aspect, a spring is disposed on the air chamber side, and the diaphragm is urged from the air chamber side to the auxiliary liquid chamber side by the spring. It is characterized by.

The operation of the vibration isolator according to the first aspect will be described below. When the vibration is transmitted from the vibration generating section to the inner cylinder or the outer cylinder, the elastic body, which is the main rubber, is deformed, and a pair of pressure-receiving liquids disposed across the inner cylinder while being communicated with each other. The chamber expands and contracts, and the liquid flows between the pair of pressure receiving liquid chambers. That is, the pair of pressure receiving liquid chambers are arranged so as to be of a differential type in accordance with the movement of the inner cylinder.

For this reason, not only is the vibration attenuated by the deformation of the elastic body, but also the vibration is attenuated by the passage resistance of the liquid between the pair of pressure receiving liquid chambers or the liquid column resonance, etc. Vibration is less likely to be transmitted to the connected vibration receiver.

Further, a sub-liquid chamber is communicated with any one of the pair of pressure-receiving liquid chambers through a restriction passage, and a part of the partition wall of the sub-liquid chamber is formed so that the diaphragm can be elastically deformed. The air chamber is disposed opposite the sub liquid chamber with the diaphragm interposed therebetween. Then, a valve connected to the air chamber and the negative pressure source opens and closes a flow path between the air chamber and the negative pressure source.

Therefore, when a vibration having a frequency that cannot be reduced by the flow of the liquid between the pair of pressure receiving liquid chambers is input, the valve is opened and closed to switch the diaphragm to a deformable state, thereby opening the restriction passage. The pressure change is transmitted to the diaphragm serving as the partition wall of the sub liquid chamber via the sub-liquid chamber, and as the diaphragm elastically deforms, the liquid receives a passage resistance in the restricted passage or resonates with the liquid column.

For this reason, when vibration having a frequency that cannot be reduced by the flow of the liquid between the pair of pressure receiving liquid chambers is input, not only the vibration is attenuated by the deformation of the elastic body, but also the restriction passage. Vibration is reduced by the passage resistance of the liquid in the inside or the liquid column resonance, and the vibration is less likely to be transmitted to the vibration receiving portion connected to the outer cylinder or the inner cylinder.

As described above, by making the pair of pressure receiving liquid chambers a differential type, when the inner cylinder moves to either side of the pair of pressure receiving liquid chambers and the internal volume of one of the pressure receiving liquid chambers is reduced. According to this, the internal volume of the other pressure receiving liquid chamber is expanded. Therefore, it is not necessary to increase the size of the air chamber in consideration of the expansion of the diaphragm in order to absorb the liquid amount when a large stroke amplitude occurs.

Further, if the pair of pressure-receiving liquid chambers is of a differential type, as the inner cylinder moves, one of the pressure-receiving liquid chambers pushes out liquid by a volume change, and the other pressure-receiving liquid chamber side changes by volume. Since the shape of pulling the liquid is integrally generated by the deformation of the elastic body, the flow efficiency of the liquid is excellent and a large resonance is easily obtained.

On the other hand, by adopting the differential type, the air chamber disposed opposite to the sub liquid chamber with the diaphragm interposed therebetween can be made smaller, so that the amount of suction of the diaphragm to the air chamber side can be reduced, and the negative pressure can be reduced. The load on the source can be reduced.

The operation of the vibration isolator according to claim 2 will be described below. The present invention has the same effect as the first embodiment. However, in the present invention, the spring is arranged on the air chamber side, and the diaphragm is urged from the air chamber side to the sub liquid chamber side by the spring.

For this reason, when the valve is closed, the diaphragm is pressed against the wall surface forming the sub liquid chamber by the spring, so that the diaphragm cannot be deformed. Also,
When the valve is opened, the diaphragm moves due to the negative pressure against the urging force of the spring, and the diaphragm becomes deformable.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 4 show a vibration isolator 10 according to a first embodiment of the present invention, and the present embodiment will be described with reference to these drawings.

As shown in FIGS. 1 and 2, a mounting frame 14 for forming an outer frame of the vibration isolator 10 according to the present embodiment.
A cylindrical outer tube fitting 16 is inserted and disposed inside the inside, and an intermediate tube 18 made of a steel plate is fitted on the inner peripheral surface side of the outer tube fitting 16.

As shown in FIG. 2 and FIG.
Has a pair of flange portions 18B at both ends thereof, which are spread to the outer peripheral side and are fitted to the inner peripheral side of the outer cylinder fitting 16,
An intermediate portion of the intermediate cylinder 18 is a small-diameter portion 18A formed in a small-diameter cross-section with a different diameter.

An elastic body 20, which is a main rubber made of rubber, is vulcanized and bonded to the intermediate cylinder 18, and an inner cylinder extending parallel to the axis of the intermediate cylinder 18 is provided at the center of the elastic body 20. A metal fitting 22 is disposed, and the elastic body 20 is
It is also vulcanized. Further, a coating rubber 20A connected to the elastic body 20 is also vulcanized and bonded to the outer peripheral surface of the small diameter portion 18A of the intermediate cylinder 18 so as to have the same outer diameter as the flange portion 18B.

When the mounting frame 14 is mounted on the vehicle body and the inner tube fitting 22 is connected to the engine by bolts or the like,
The load of the engine is supported by the vehicle body via the inner cylinder 22, the elastic body 20, the intermediate cylinder 18, the outer cylinder 16, and the mounting frame 14.

On the other hand, concave portions 24 and 26 are formed in the upper and lower portions of the elastic member 20 on the upper and lower sides of the inner cylindrical member 22, respectively.
A pair of cutouts 18C, 18D are formed in accordance with 4, 26, respectively. Also, the intermediate cylinder 1 corresponding to the upper concave portion 26
An arc-shaped partition member 30 is arranged between the small-diameter portion 18 </ b> A of FIG. Further, a space between the concave portion 26 of the elastic body 20 and the partition member 30 is defined as one pressure receiving liquid chamber 34, and a space between the concave portion 24 of the elastic body 20 and the inner peripheral surface of the outer cylinder 16 is the other. Pressure receiving liquid chamber 32
It has been.

A hole 30B penetrating through the partition member 30 is formed in the leftward portion of the partition member 30 in FIG. 1, and this hole 30B is formed outside the partition member 30 as shown in FIG. A groove 30 </ b> C extending in a U-shape from the left end of the partition member 30 to the left end of the partition member 30 is formed.

A groove 38 extending in the circumferential direction of the small diameter portion 18A is formed at a position corresponding to the end of the groove 30C of the covering rubber 20A arranged on the outer peripheral surface of the small diameter portion 18A of the intermediate cylinder 18. I have. The hole 30B, the groove 30C, and the groove 38 form a first restriction passage 56, and the first restriction passage 56 allows the pair of pressure receiving liquid chambers 3 to be formed.
Communication is made between 2, 34.

Further, a through hole 42 extending in the left-right direction in FIG. 1 is formed in the partition member 30. As shown in FIG. 1, one end of the through hole 42 is bent downward to form the small diameter portion 18A. Is connected to the pressure receiving liquid chamber 32 via a groove 40 formed in the covering rubber 20A on the outer peripheral side of the intermediate cylinder 18 so as to extend along the circumferential direction of the intermediate cylinder 18. This through hole 42
Is bent upward and is connected to a liquid chamber recess 30 </ b> A formed on the outer peripheral surface of the partition member 30. At the position of the outer tube fitting 16 corresponding to the liquid chamber recess 30A, a through hole 5 is provided.
4 is formed, and a pipe 44 is attached to a portion of the attachment frame 14 corresponding to the through hole 54.

On the other hand, as shown in FIGS. 1 and 3, a peripheral portion of a diaphragm 50, which is an elastic film made of rubber, is vulcanized and bonded to the distal end side of the block 46 formed in a ring shape. A vulcanized diaphragm 50 is sandwiched separately from the block 46, and the block 46 is
A, the liquid chamber recess 30 of the partition member 30 is fitted.
The peripheral edge of the diaphragm 50 is sandwiched between the inner wall surface of the block A and the block 46.

That is, the space in the block 46 connected to the end of the through hole 42 is partitioned by the diaphragm 50, so that the space in the block 46 near the through hole 42 forms the sub liquid chamber 48. The space between the inner peripheral surface of the outer tube fitting 16 and the diaphragm 50 is an air chamber 52, which allows the diaphragm 50 to be deformed. Then, the second portion is formed by the groove portion 40 and the through hole
Of the pressure receiving liquid chamber 32 and the auxiliary liquid chamber 48 are communicated by the second restricting path 58.

The pair of pressure receiving liquid chambers 32, 34,
A liquid such as ethylene glycol is sealed in the auxiliary liquid chamber 48 and the restriction passages 56 and 58.

On the other hand, a switching valve 72, which is an electromagnetically operated valve, is connected to the pipe 44 via a connecting pipe 70, and an intake manifold 74 on the intake side of the engine and serving as a negative pressure source. Connection pipe 76 connected to
Is connected to the switching valve 72. The switching valve 72 forms a three-port two-position switching valve, and is connected to the air chamber 52 between the negative pressure side communicating with the intake manifold 74 via the connection pipe 76 and the atmosphere side.
The switching valve 72 can switch the zero flow path.

The switching valve 72 is connected to a control circuit 60 which is a control means for switching the switching valve 72 by judging the driving condition of the vehicle. The control circuit 60 is driven by a vehicle power supply, and can detect a vehicle speed and an engine speed by receiving detection signals from at least a vehicle speed sensor 62 and an engine speed sensor 64 for determining a driving state of the vehicle. Thus, the control circuit 60 can determine whether the vehicle is running or stopped.

Accordingly, the operation of the switching valve 72 for switching the flow path is controlled by the control circuit 60, and when the switching valve 72 communicates the air chamber 52 with the atmosphere, the negative pressure generated by the intake manifold 74 is reduced. Will be shut off.

As a result, as shown in FIG. 1, the diaphragm 50 is located in the middle of the space in the block 46, and the diaphragm 50 can be deformed between the auxiliary liquid chamber 48 and the air chamber 52. , The auxiliary liquid chamber 48 can be expanded and contracted. Therefore, the second restriction passage 58 that connects the pressure receiving liquid chamber 32 and the sub liquid chamber 48 can attenuate the vibration.

When the switching valve 72 communicates the air chamber 52 with the intake manifold 74, the communication with the atmosphere is cut off.

As a result, as shown in FIG. 4, the diaphragm 50 moves to the inner wall surface side of the air chamber 52, and the diaphragm 50 is brought into close contact with the inner peripheral surface of the outer tube fitting 16 so that it cannot be deformed. As a result, the auxiliary liquid chamber 48 cannot be expanded or contracted, and the second restriction passage 58 is substantially closed.

That is, by switching the air flow path by the switching valve 72, the second restriction passage 58 is substantially opened and closed.

In this embodiment, the passage length of the first restriction passage 56 is longer than the passage length of the second restriction passage 58, and the first cross-sectional area of the second restriction passage 58 is larger than that of the second restriction passage 58. The passage cross-sectional area of the restriction passage 56 is smaller.

Next, the operation of the vibration isolator 10 according to the present embodiment will be described. When the engine of the vehicle (not shown) is started, the pressure in the intake manifold 74 becomes negative.

Accordingly, when vibrations are transmitted from the engine side to the inner cylinder 22, the elastic body 20, which is the main rubber, is deformed, and the inner cylinder 22 is communicated with the elastic body 20.
The pair of pressure receiving liquid chambers 32 and 34 disposed therebetween sandwiches the first restriction passage 56 between the pair of pressure receiving liquid chambers 32 and 34.
The liquid flows inside. That is, the pair of pressure receiving liquid chambers 32, 3
4 are arranged so as to be of a differential type in accordance with the movement of the inner tube fitting 22.

Therefore, not only the vibration is attenuated by the deformation of the elastic body 20, but also the vibration is attenuated by the passage resistance of the liquid between the pair of pressure receiving liquid chambers 32 and 34, and the outer cylinder 1
Vibration is less likely to be transmitted to the vehicle body connected to the vehicle body 6 via the mounting frame 14.

Further, a second restriction passage 58 is provided in the pressure receiving liquid chamber 32.
The sub-liquid chamber 48 is communicated with the sub-liquid chamber 48, and a part of the partition wall of the sub-liquid chamber 48 is formed so that the diaphragm 50 can be elastically deformed. The air chamber 52 is connected to the sub-liquid chamber 48 with the diaphragm 50 interposed therebetween. It is arranged facing. The switching valve 72 connected to the air chamber 52 and the intake manifold 74 opens and closes a flow path between the air chamber 52 and the intake manifold 74.

Therefore, when vibration having a frequency that cannot be attenuated by the flow of the liquid between the pair of pressure receiving liquid chambers 32 and 34 is input, the switching valve 72 is opened and closed to switch the diaphragm 50 to a deformable state. , The second restricted passage 58
The pressure change is transmitted to the diaphragm 50 serving as a partition wall of the sub liquid chamber 48 via the liquid crystal. As the diaphragm 50 elastically deforms, the liquid receives a passage resistance in the second restriction passage 58 or resonates with the liquid column. .

Therefore, when vibration having a frequency that cannot be attenuated by the flow of the liquid between the pair of pressure receiving liquid chambers 32 and 34 is input, not only the vibration is attenuated by the deformation of the elastic body 20 but also the vibration is attenuated. Vibration is reduced due to the passage resistance of the liquid in the second restriction passage 58 or liquid column resonance or the like, and it becomes difficult for the vibration to be transmitted to the vehicle body connected to the outer tube fitting 16.

The specific operation will be described below. For example, when the vehicle runs, shake vibration occurs. Control circuit 60
Is determined by the vehicle speed sensor 62 and the engine speed sensor 64 to be at the time of occurrence of shake vibration, and the switching valve 72 is switched to bring the inside of the air chamber 52 into a negative pressure state. As a result, as shown in FIG.
6, and the auxiliary liquid chamber 48 cannot be expanded or contracted,
The second restriction passage 58 is substantially closed. Therefore, the liquid actively moves in the first restriction passage 56 and receives a passage resistance in the first restriction passage 56, or the liquid column resonates to absorb the shake vibration.

On the other hand, for example, when the vehicle stops, idle vibration occurs in which the vibration frequency is higher than shake vibration. In this case, the first restriction passage 56 is clogged,
At this time, the control circuit 60 determines from the vehicle speed sensor 62 and the engine speed sensor 64 that idle vibration has occurred, and switches the switching valve 72 to communicate the inside of the air chamber 52 with the atmosphere.

As a result, the inside of the air chamber 52 is brought into an atmospheric state at the same pressure as the atmospheric pressure, and as shown in FIG. 1, the diaphragm 50 is separated from the inner peripheral surface of the outer tube fitting 16 and the auxiliary liquid chamber 48 is opened.
Can be expanded and contracted, and the liquid can move back and forth in the second restriction passage 58. As a result, the second restriction passage 5
The liquid column resonates in the liquid 8, the dynamic spring constant of the vibration isolator 10 is reduced, and the idle vibration is absorbed.

As described above, when the vehicle is running and when it is stopped,
The frequency of the vibration generated by the engine is different from each other, but the pressure in the air chamber 52, which is located opposite to the auxiliary liquid chamber 48 with the diaphragm 50 interposed therebetween, is switched by the switching valve 72 to cope with the frequency difference. it can. As a result, the characteristics of the vibration isolator 10 can be changed depending on whether the air chamber 52 is communicated with the atmosphere side or the intake manifold 74 by the switching valve 72, and the vibration can be absorbed over a wide frequency range.

Further, since the pair of pressure receiving liquid chambers 32 and 34 are of a differential type, the inner cylinder fitting 22 moves to either side of the pair of pressure receiving liquid chambers 32 and 34 and one of the pressure receiving liquid chambers 32 and 34 moves. When the internal volume of the chamber is reduced, the internal volume of the other pressure-receiving liquid chamber is expanded accordingly. Therefore, it is not necessary to enlarge the air chamber 52 in consideration of the swelling of the diaphragm 50 in order to absorb the liquid amount when a large stroke amplitude occurs.

Further, if the pair of pressure receiving liquid chambers 32 and 34 are of a differential type, as the inner cylinder 22 moves,
The elastic body 2 has a shape in which one of the pressure receiving liquid chambers pushes out the liquid with a change in volume and the other pressure receiving liquid chamber draws the liquid with a change in volume.
Since it is generated integrally by the deformation of 0, the liquid flow efficiency is excellent and a large resonance is easily obtained.

On the other hand, by adopting the differential type, the air chamber 52 disposed opposite to the auxiliary liquid chamber 48 with the diaphragm 50 interposed therebetween can be made small, so that the suction amount of the diaphragm 50 to the air chamber 52 side is also small. As a result, the load on the intake manifold 74 can be reduced.

FIGS. 5 and 6 show a vibration isolator 10 according to a second embodiment of the present invention, and the present embodiment will be described with reference to these drawings. The same members as those described in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIGS. 5 and 6, in the vibration isolator 10 according to the present embodiment, the coil spring 82
And an actuator 80 having a disk 84 disposed at one end of the coil spring 82 is attached to the outer peripheral side of the outer cylinder 16 facing the air chamber 52.

A ring-shaped elastic support film 86 made of rubber is bonded to the outer periphery of the disk 84 by vulcanization.
And the air chamber 88 inside the actuator 80 is sealed, and one end of a connection pipe 70 to which the switching valve 72 is connected is connected to the actuator 80.

On the other hand, at the center of the disk 84, a base end side of an operation member 90 having a pressing plate 90A for pressing the diaphragm 50 at the distal end is fixed. A wall 46A is formed on the base end side of the ring-shaped block 46, and a shaft portion 90B near the base end side of the operation member 90 passes through the wall 46A of the block 46.

Therefore, in the present embodiment, the coil spring 82 is arranged on the air chamber 52 side, and the diaphragm 50 is moved by the coil spring 82 via the pressing plate 90A of the operating member 90 to the air chamber 52 side. From the bottom of the liquid chamber recess 30A forming the sub liquid chamber 48.

As described above, by closing the space between the intake manifold 74 and the intake manifold 74 by the switching valve 72 during the shake vibration, as shown in FIG.
As a result, the diaphragm 50 is pressed against the wall surface forming the sub liquid chamber 48, and the diaphragm 50 becomes in a state where it cannot be deformed.

Also, during idle vibration, the switching valve 7
By opening the space between the intake manifold 74 and the intake manifold 74, the pressure in the air chamber 88 becomes negative, and the pressing plate 90A moves while resisting the urging force of the coil spring 82 due to the negative pressure as shown in FIG. At the same time, the diaphragm 50 moves, and the diaphragm 50 becomes deformable.

That is, in the present embodiment, the air chamber 52 and the air chamber 88 constitute an air chamber integrally.

In the above-described embodiment, the configuration in which the vibration isolator 10 is used as an engine mount is shown. However, the present invention is not limited to this, and the vibration isolator 10 can be mounted on a cab mount, a body mount, or a general industrial machine. Needless to say, it may be used for other purposes.

In the above-described embodiment, the outer cylinder is connected to the vehicle body serving as the vibration receiving portion, and the inner cylinder is connected to the engine side serving as the vibration generating portion. Is also good.

[0065]

As described above, the vibration damping device of the present invention has an excellent effect of improving the vibration damping characteristics while reducing the volume of the air chamber.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an anti-vibration device according to a first embodiment of the present invention, which is a cross-sectional view during idle vibration.

FIG. 2 is a sectional view taken along line 2-2 of the vibration isolator shown in FIG.

FIG. 3 is an exploded perspective view showing a partition member, an intermediate cylinder, an elastic body, a diaphragm, and the like of the vibration isolator according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of the vibration isolator according to the first embodiment of the present invention, which is a cross-sectional view at the time of shake vibration.

FIG. 5 is a cross-sectional view of the vibration isolator according to the second embodiment of the present invention, which is a cross-sectional view at the time of idle vibration.

FIG. 6 is a cross-sectional view of the vibration damping device according to the second embodiment of the present invention, which is a cross-sectional view at the time of shake vibration.

FIG. 7 is a sectional view of a conventional vibration isolator.

8 is a sectional view taken along line 8-8 of the vibration isolator shown in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration isolator 16 Outer cylinder fitting 20 Elastic body 22 Inner cylinder fitting 32 Pressure receiving liquid chamber 34 Pressure receiving liquid chamber 48 Sub liquid chamber 50 Diaphragm 52 Air chamber 72 Switching valve 82 Coil spring 88 Air chamber

Claims (2)

[Claims] An 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 an inner cylinder provided between the inner cylinder and the outer cylinder. An elastic body that connects the inner cylinder and the outer cylinder and deforms when vibration occurs, and that the elastic body is arranged at least as a part of the partition wall with the inner cylinder interposed therebetween and is communicated with each other and filled with liquid respectively. A pair of pressure-receiving liquid chambers, a sub-liquid chamber communicated with any of the pair of pressure-receiving liquid chambers via a restriction passage, and a diaphragm formed so that a part of a partition of the sub-liquid chamber can be elastically deformed. And an air chamber disposed opposite to the auxiliary liquid chamber with the diaphragm interposed therebetween, and connected to the air chamber and the negative pressure source, and can be deformed by opening and closing a flow path between the air chamber and the negative pressure source. Valve capable of switching diaphragm state between state and non-deformable state , Anti-vibration apparatus characterized by comprising a. 2. The vibration damping device according to claim 1, wherein a spring is arranged on the air chamber side, and the spring urges the diaphragm from the air chamber side to the auxiliary liquid chamber side.