JPH1163089A - Vibration proof apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attenuate vibration of a low frequency area, and at the same time ensure a low vibration spring in a high frequency area. SOLUTION: A shield member 28 is arranged inside of an outer cylinder bracket 16, and a space partitioned by a shield member 28 and an elastic body 18 constitutes a main liquid chamber 30. An idle orifice 60 and a confinement orifice 62 are formed at the shield member 28, and these orifices are switched by a rotor 46A. The confinement orifice 62 is served as a restraint passage for confinement sound absorption by communicating with the main liquid chamber 30 and a second subsidiary liquid chamber 56.

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 or attenuated as a low dynamic spring due to the liquid column resonance of the liquid in the restricted passage connecting these liquid chambers. Thus, the transmission of vibration is prevented.

[0004] On the other hand, the vibration frequency becomes wide with the wide operating state of the engine. Therefore, in order to maintain the vibration isolating characteristics even in such vibrations of a wide range of frequencies, a vibration isolating device having restrictive passages having various lengths and inner diameters and installing an actuator for switching these restrictive passages has recently been developed. Came to be devised.

Further, a rubber membrane is provided on a side of the partition member which separates the main liquid chamber and the sub liquid chamber from the main liquid chamber, and a deformation of the membrane causes a muffled sound which is high frequency vibration. 2. Description of the Related Art A vibration isolator having a structure in which a muffled sound is reduced by lowering a dynamic spring in a region is known.

[0006]

However, when a membrane is provided on the side of the partition member facing the main liquid chamber, the effect of lowering the dynamic spring in the region of the muffled sound is obtained, but the main body is deformed by deformation. Since the internal pressure of the liquid chamber is absorbed, the internal pressure loss in the main liquid chamber increases, and there is a possibility that the attenuation in the low frequency range becomes insufficient.

In other words, in the above structure, the low dynamic spring in the high frequency range and the attenuation in the low frequency range are incompatible, so that it is necessary to reduce the dynamic spring in the muffled sound region. In this case, there is a disadvantage that vibrations in a low frequency range generated in a high speed range of the vehicle are not sufficiently attenuated.

The present invention has been made in consideration of the above-described circumstances, and has as its object to provide a vibration isolator capable of reducing vibration in a low frequency range and reducing dynamic springs in a high frequency range.

[0009]

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 first sub-liquid chamber in which at least a part of the partition wall is formed to be elastically deformable; a plurality of first passages respectively communicating between the main liquid chamber and the first sub-liquid chamber; A partition member for partitioning between the first sub-liquid chamber, a second sub-liquid chamber disposed in the partition member and at least a part of the partition wall being formed to be elastically deformable, and formed in the partition member; A second passage communicating between the main liquid chamber and the second sub liquid chamber, and at least one of the plurality of first passages A valve for opening and closing, is connected to the valve and having a, an actuator for actuating the valve.

According to a second aspect of the present invention, there is provided the vibration isolator according to the first aspect, wherein the air chamber filled with the gas is provided with the second deformable partition wall of the second sub liquid chamber interposed therebetween. It is characterized by being incorporated in the partition member so as to be adjacent to the sub liquid chamber.

The operation of the vibration isolator according to claim 1 will be described below. When the vibration in the low frequency range is transmitted from the vibration generating section connected to any of the mounting members, the elastic body is deformed and the vibration is attenuated by the elastic body. Further, the internal volume of the main liquid chamber changes due to the deformation of the elastic body, and is switched by being opened and closed by valves in a plurality of first passages communicating between the first sub liquid chamber and the main liquid chamber. The pressure in the liquid in the first passage is changed, and accordingly, the partition wall of the first sub liquid chamber is elastically deformed.

That is, when the vibration in the low frequency range is transmitted from the vibration generating section, the actuator operates the valve in accordance with the frequency of the vibration, and opens or closes any one of the plurality of first passages to optimize the vibration. Select the appropriate first passage. For this reason, not only the elastic body but also the liquid in the first passage attenuates the vibration in the low frequency range or lowers the dynamic spring constant, making it difficult for the vibration to be transmitted to the vibration receiving portion side.

On the other hand, the frequency of vibration changes, and a vibration in a high frequency range between the main liquid chamber and the first sub liquid chamber, which cannot reduce the vibration, is connected to one of the mounting members. When transmitted from the side, the inner volume of the main liquid chamber changes due to the deformation of the elastic body as described above. Further, a change in the internal volume of the main liquid chamber causes a pressure change in the liquid in the second passage communicating between the second sub liquid chamber and the main liquid chamber. Of the auxiliary liquid chamber is elastically deformed.

As a result, when the vibration in the high frequency range is transmitted from the vibration generating section, the dynamic spring constant is reduced by the second passage connected to the second auxiliary liquid chamber, and the vibration in the high frequency range is absorbed. However, it becomes difficult for the vibration to be transmitted to the vibration receiving portion side.

Further, by incorporating the second passage and the second sub-liquid chamber in the partition member, the internal pressure loss in the main liquid chamber is reduced, and the high frequency band is reduced by the second passage and the second sub-liquid chamber. Can cause liquid column resonance.

In other words, vibration is attenuated in a low frequency range and the dynamic spring is reduced. At the same time, the dynamic spring is reduced in a high frequency range. Vibration can be reduced.

For example, when the vibration generating unit is an engine and the vibration receiving unit is a vehicle body, the vibration in the high frequency range of the vehicle, in which the vibration in the low frequency range is generated, is attenuated while the vibration in the low frequency range In this case, liquid column resonance is generated in the region of the booming sound, the dynamic spring constant is reduced, and the vibration can be reduced.

On the other hand, in the present invention, the second passage and the second auxiliary liquid chamber are built in the partition member, so that the second passage can be formed short and the space for disposing the second auxiliary liquid chamber is reduced. As a result, the rigidity of the diaphragm, which is the elastically deformable partition of the second sub liquid chamber, can be freely set, and the degree of freedom in setting the resonance frequency of the liquid column resonance is expanded.

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 air chamber in which the gas is sealed is built in the partition member so as to be adjacent to the second sub liquid chamber with the elastically deformable partition wall of the second sub liquid chamber interposed therebetween. Configuration.

For this reason, by incorporating not only the second passage and the second auxiliary liquid chamber but also the air chamber in the partition member, the capacity of the air chamber can be freely set, and the resonance frequency of the liquid column resonance can be set. The degree of freedom of setting has been further expanded.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a vibration isolator according to the present invention is shown in FIGS. 1 to 6, and this embodiment will be described with reference to these drawings.

As shown in FIG. 1 showing the present embodiment, a dish-shaped bottom plate 12 as a first mounting member is formed on the lower side of the vibration isolator 10. Bolts 14 for connecting and fixing the vibration isolator 10 to a vehicle body (not shown) are implanted. And this bottom plate fitting 1
A flange portion 12A is provided on the outer side of 2, and an outer tube fitting 16 which is cylindrical and formed so that the upper side expands is disposed above the flange portion 12A.

A rubber-made elastic member 18 having a cylindrical shape is vulcanized and bonded to the inner peripheral surface of the outer tube fitting 16, and the lower portion of the elastic member 18 is thin and extends downward in a ring shape. The thin rubber layer 18A constitutes. A central portion of the upper side of the elastic body 18 is vulcanized and bonded to a top plate 20 serving as a second mounting member, and a bolt 22 used for connecting an engine (not shown) is formed from the center of the top plate 20.
It protrudes upward.

A cylindrical partition member 28 is disposed below the elastic body 18 and at a position sandwiching the space between the elastic body 18 and the cylindrical partition member 28 while being fitted to the outer tube fitting 16 via a thin rubber layer 18A. The space defined by the elastic body 18 and the partition member 28 constitutes a main liquid chamber 30, in which a liquid such as water or oil is sealed. Therefore, the partition of the main liquid chamber 30 in which the liquid is sealed is constituted by the elastic body 18 and the partition member 28. Note that the partition member 28 can be manufactured by integral molding of a synthetic resin, a metal such as aluminum, or the like.

The lower part of the partition member 28 protrudes toward the outer periphery, and the lower part of the partition member 28 is sandwiched between the lower part of the outer tube fitting 16 and the flange 12A of the bottom plate fitting 12. I have. The lower portion of the outer tube fitting 16 is caulked to the outer peripheral portion of the flange portion 12A of the bottom plate fitting 12, so that the bottom plate fitting 12, the outer tube fitting 16 and the partition member 28 are integrally fixed.

Further, a first diaphragm 26 made of a thin and elastically deformable rubber is sandwiched between the lower portion of the partition member 28 and the flange portion 12A of the bottom plate 12, and the partition member 28 is sandwiched therebetween. Are arranged so as to face the lower surface.

As described above, the space formed between the first diaphragm 26 and the lower surface of the partition member 28 is the first auxiliary liquid chamber 32, and the lower side of the first diaphragm 26 and the bottom plate metal fitting are provided. 12 is the first air chamber 40
Thus, the deformation of the first diaphragm 26 is facilitated.

As shown in FIG. 1, a groove 34 is formed on the outer peripheral surface of the partition member 28 along the circumferential direction of the partition member 28. The groove 34 and the inner peripheral surface of the thin rubber layer 18A are formed by the groove 34. One end of the shake orifice 64, which is a formed passage, extends upward and is connected to the main liquid chamber 30. Further, the other end of the shake orifice 64 extends inward and is connected to the first auxiliary liquid chamber 32. Then, the shake orifice 64 is used as a restriction passage for absorbing shake vibration.

On the other hand, as shown in FIGS. 1 to 3, the partition member 28 is formed with a circular hole 36 which is a large-diameter passage extending along the radial direction of the partition member 28.
Has one end opened upward and connected to the main liquid chamber 30.
A counterbore 38 having a larger diameter than the circular hole 36 is formed at the other end of the circular hole 36, and a sleeve 42 is fitted in the counterbore 38.

A rotor 46 as a valve is rotatably inserted into the sleeve 42. This rotor 46
In FIG. 1, the right portion is a large-diameter cylindrical portion 46A, and the left portion in FIG. 1 is a thin shaft portion 46B as a rotating shaft. Further, an O-ring (not shown) is fitted around the outer periphery of the thin shaft portion 46B.
The ring prevents the liquid from leaking out of the partition member 28 through the gap with the sleeve 42.

As shown in FIG. 3, a pair of through-holes 48 communicating with the inside and outside of the cylindrical portion 46A are formed in portions of the cylindrical portion 46A of the rotor 46 which are different from each other by 180 ° in the circumferential direction. I have.

On the other hand, a communication hole 50 is formed in the portion of the sleeve 42 and the partition member 28 corresponding to the lower side of the cylindrical portion 46A, and the through hole 48 is opposed to the communication hole 50 by the rotation of the rotor 46. Then, the circular hole 36 and the first sub liquid chamber 32
Is communicated with.

That is, by the circular hole 36 and the communication hole 50,
An idle orifice 60 which communicates with the main liquid chamber 30 and the first sub liquid chamber 32 and serves as a restriction passage for absorbing idle vibration is formed.

On the other hand, as shown in FIGS. 2 and 3, the sleeve 42 and the partition member 28 corresponding to the side of the cylindrical portion 46A are provided.
Is formed with a small-diameter hole 52 for the stagnation from the cylindrical portion 46A obliquely downward. A second sub-liquid chamber 56, which is a disc-shaped space, is formed in a portion in the partition member 28 corresponding to the opening end of the hole 52, and an end of the hole 52 is formed. Are opened to the second auxiliary liquid chamber 56. Therefore, when the rotor 46 rotates and the through hole 48 faces the hole 52 for stagnation, communication between the circular hole 36 and the second auxiliary liquid chamber 56 is established.

That is, the circular orifice 62 and the orifice hole 52 communicate the main liquid chamber 30 and the second sub-liquid chamber 56 to serve as a restriction passage for absorbing the muffled sound.
Is configured.

The partition member 2 above the second sub liquid chamber 56
A thin rubber-made second diaphragm 54 is disposed in the inside 8, and this second diaphragm 54 is a partition wall of the second sub liquid chamber 56 that can be elastically deformed.

A cover 66 is disposed above the partition member 28 with the space between the second diaphragm 54 and the space therebetween, and the space between the second diaphragm 54 and the space between the second diaphragm 54 is sealed by the cover 66. Gas such as air is sealed inside.

That is, the space between the second diaphragm 54 and the lower surface of the lid 66 is defined as a second air chamber 58 which is built in the partition member 28 and in which gas is sealed. A chamber 58 is disposed adjacent to the second sub-liquid chamber 56 with a second diaphragm 54 being an elastically deformable partition wall of the second sub-liquid chamber 56 interposed therebetween.
4 is possible.

That is, the second diaphragm 54 constitutes a part of the partition wall of the second auxiliary liquid chamber 56. As shown in FIG. 3, the area of the second diaphragm 54 is equal to the first auxiliary liquid chamber. The first diaphragm 26 forming a part of the partition wall 32
Is smaller than the area of the second diaphragm 5.
4 has higher rigidity than the first diaphragm 26.

With the above structure, when the rotor 46 is rotated and the through hole 48 of the cylindrical portion 46A opens the idle orifice 60 as shown in FIGS. 1 to 3, the main liquid is passed through the idle orifice 60. The chamber 30 and the first sub liquid chamber 32 communicate with each other. Further, when the rotor 46 is rotated by 90 ° from this position, and the through hole 48 of the cylindrical portion 46A opens the orifice 62 as shown in FIGS. 4 to 6, the main liquid chamber is opened via the orifice 62. The 30 and the second sub liquid chamber 56 are communicated. For this reason, these orifices 60 and 62 are opened and closed by the rotor 46 to switch the passage.

On the other hand, a through hole 68 is formed in a portion of the side wall of the outer shell 16 that corresponds to the sleeve 42 and that corresponds to the outer shell 16 and the thin rubber layer 18A. This through hole 6
A motor 70 as an actuator is disposed on the outer peripheral side of the outer cylindrical bracket 16 corresponding to the motor 8, and the motor 70 is fixed to the outer peripheral side of the outer cylindrical bracket 16 by screwing with a mounting screw (not shown). Will be. The rotating shaft 70A of the motor 70 is connected to the thin shaft portion 4 of the rotor 46.
6B.

As described above, the rotor 46 is connected to the main liquid chamber 30 through the idle orifice 60 as shown in FIGS.
And the first sub-liquid chamber 32, and the main liquid chamber 30 and the second sub-liquid chamber 56 via the orifice 62 as shown in FIGS. The rotation is performed by the motor 70 so as to selectively adopt the above arrangement. The motor 70 is connected to a controller 72 as control means, and its rotation is controlled by the controller 72. The controller 72 is operated by a vehicle power supply, receives detection signals from at least the vehicle speed sensor 74 and the engine speed detection sensor 76, detects the vehicle speed and the engine speed, and can determine whether idle vibration or shake vibration occurs. It has become.

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, the elastic body 18 and the first diaphragm 2
The main liquid chamber 30 whose inner volume changes with the deformation
The liquid in the sub liquid chamber 32 not only flows mutually through the orifices 60 and 64, but also the liquid flows between the second sub liquid chamber 56 and the main liquid chamber 30 with the deformation of the second diaphragm 54. The damping action based on the viscous resistance of the liquid flow generated in the orifice space and the liquid column resonance, etc., can improve the vibration isolation effect.

In addition to the normally open shake orifice 64, an orifice 62 and an idle orifice 60 are provided, and a rotor 46 for switching the passage between the orifice 62 and the orifice 60 is provided. As a result, it operates as follows.

When the vehicle runs at a high speed of, for example, 70 to 80 km / h or more, shake vibration (less than 15 Hz) occurs. The controller 72 determines whether or not a shake vibration has occurred based on a vehicle speed sensor 74 and an engine speed detection sensor 76. When the controller 72 determines that shake vibration is occurring, the controller 72 operates the motor 70 to rotate the rotor 46, and as shown in FIGS. 4 to 6, the through-hole 48 is made to correspond to the orifice 62 for retraction. The arrangement does not correspond to the idle orifice 60.

As a result, the idle orifice 60 is closed, the normally open shake orifice 64 communicates the main liquid chamber 30 with the first sub liquid chamber 32, and the confined orifice 62 connects the main liquid chamber 30 with the first liquid chamber 30. Second sub-liquid chamber 56
And communicate with.

As a result, the pressure change based on the engine vibration generated in the main liquid chamber 30 is transmitted to the liquid in the shake orifice 64 and the liquid in the orifice 62, and the vibration of the liquid is absorbed by receiving the resistance of the liquid.

Further, a muffled sound (50 to 10) which is a high-frequency and small-amplitude vibration which may be generated together with the shake vibration.
0 Hz), the liquid column resonates within the orifice 62 built in the partition member 28, and the dynamic spring constant decreases,
Muffled sound is absorbed.

When the engine is idling or the vehicle speed is 5 km / h or less, idle vibration (20 to
40 Hz). The controller 72 is a vehicle speed sensor 7
4. It is determined by the engine speed sensor 76 whether idle vibration has occurred. When the controller 72 determines that idle vibration has occurred, the controller 72 rotates the motor 70 to make the through hole 48 of the rotor 46 correspond to the idle orifice 60 as shown in FIGS. An arrangement not corresponding to 62 is made.

As a result, the orifice 62 is closed, and the liquid passes through the idle orifice 6 having a small passage resistance.
Thus, the main liquid chamber 30 and the first sub liquid chamber 32 come and go through 0, the liquid column resonates in the idle orifice 60, the dynamic spring constant decreases, and the vibration is absorbed.

At this time, since the shake orifice 64 has a large passage resistance, the shake orifice 64 is necessarily clogged and closed.

Further, unlike the conventional membrane provided on the side of the partition member facing the main liquid chamber, in the present embodiment, the partition orifice 62 and the second orifice 62
The liquid column resonance in the high frequency region by the orifice 62 and the second sub liquid chamber 56 while reducing the internal pressure loss in the main liquid chamber 30 by incorporating the sub liquid chamber 56 of FIG. Can be.

That is, according to the vibration isolator 10 of the present embodiment, the vibration of the shake vibration in the low frequency range is reduced and the dynamic spring of the idle vibration is reduced. By reducing the dynamic spring in the frequency range, the vibration is appropriately absorbed at any vibration frequency, and a wide range of vibration can be reduced.

More specifically, when the vibration generating section is an engine and the vibration receiving section is the vehicle body as in the present embodiment, the vibration of a vehicle in which low-frequency vibration such as shake vibration occurs is generated. While attenuating the vibration in the high-speed range, the liquid column resonance is generated in the region of the muffled sound that is generated together with the vibration in the low-frequency range, thereby reducing the dynamic spring constant and reducing the vibration.

On the other hand, in the present embodiment, since the orifice 62 and the second auxiliary liquid chamber 56 are provided in the partition member 28, the orifice 62 for the internal storage can be shortened and the second auxiliary liquid chamber 56 is formed. As a result of sufficient space for the arrangement, the rigidity of the second diaphragm 54, which is a partition wall capable of elastic deformation of the second sub liquid chamber 56, can be set freely, and the resonance of the liquid column can be improved. The degree of freedom in setting the resonance frequency has been expanded.

On the other hand, in the present embodiment, the second air chamber 58 in which gas such as air is sealed is also used as the second auxiliary liquid chamber 56.
The partitioning member 28 is built in such a manner as to be adjacent to the second auxiliary liquid chamber 56 with the second diaphragm 54 that can be elastically deformed therebetween. For this reason, the capacity of the second air chamber 58 can be freely set, and the degree of freedom in setting the resonance frequency of the liquid column resonance is further expanded.

In the embodiment, the orifice 62 is opened and closed by the rotor 46. However, an orifice which is always open may be used as the second passage.

Further, in the embodiment, the purpose is to dampen an engine mounted on a vehicle, but it goes without saying that the damping device of the present invention can be used for other purposes. However, the present invention is not limited to the embodiment.

Further, in the embodiment, the case where the muffled sound is generated along with the shake vibration has been described. However, it is needless to say that the present invention can be applied to the case where the muffled sound is generated independently from the shake vibration. Absent.

On the other hand, in one embodiment, the rotor is rotated by the motor. However, the present invention is not limited to this. The actuator for rotating the rotor may be other than the motor, and the valve may be other than the rotor. May be used.

In the above-described embodiment, the bottom plate fitting 12 as the first mounting member is mounted on the vehicle body, and the top plate fitting 20 as the second mounting member is mounted on the engine. Is also good.

[0063]

According to the vibration isolator of the present invention, as described above, it is possible to reduce the vibration in the low frequency range and to reduce the dynamic spring in the high frequency range. became.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

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

FIG. 5 is a sectional view taken along line 5-5 of FIG. 4;

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vibration isolator 12 Bottom metal plate (first mounting member) 18 Elastic body 20 Top metal plate (second mounting member) 28 Partition member 30 Main liquid chamber 32 First sub liquid chamber 46 Rotor 56 Second sub liquid chamber 58 second air chamber 60 idle orifice (first passage) 62 orifice for spillover (second passage) 64 shake orifice (first passage) 70 motor

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 the main liquid chamber in which a liquid is sealed with the elastic body as a part of the partition and the internal volume changes due to deformation of the elastic body; and at least a part of the partition is formed to be elastically deformable. First
A plurality of first passages respectively communicating between the main liquid chamber and the first sub liquid chamber; a partition member for partitioning between the main liquid chamber and the first sub liquid chamber; A second sub-liquid chamber that is arranged in the member and at least a part of the partition wall is formed to be elastically deformable; and that is formed in the partition member and communicates between the main liquid chamber and the second sub-liquid chamber. A vibration isolator comprising: a second passage; a valve that opens and closes at least one of the plurality of first passages; and an actuator connected to the valve to operate the valve. 2. An air chamber in which a gas is sealed is a second chamber.
2. The vibration isolator according to claim 1, wherein the partitioning member is incorporated so as to be adjacent to the second sub-liquid chamber with an elastically deformable partition wall of the sub-liquid chamber interposed therebetween.