JP5226599B2 - Vibration isolator - Google Patents

Description

  The present invention relates to a vibration isolator that is used as an engine mount or the like in a general industrial machine or an automobile and absorbs and attenuates vibration transmitted from a vibration generating unit such as an engine to a vibration receiving unit such as a vehicle body.

  An anti-vibration device as an engine mount is disposed between the engine that is the vibration generation unit of the vehicle and the vehicle body that is the vibration receiving unit, and this anti-vibration device absorbs the vibration generated by the engine, Suppresses vibration transmission to As such a vibration isolator, an active damper that is an active vibration isolator has been developed. For example, Patent Documents 1 and 2 disclose a liquid-sealed engine mount including a main liquid chamber that expands and contracts according to deformation of a rubber elastic body, and a sub liquid chamber that is connected to the main liquid chamber by a restriction passage (orifice). Is disclosed.

  A partition member that constitutes a part of the partition wall of the main liquid chamber and divides the main liquid chamber from other parts is disposed inside the vibration isolator, and an annular rubber film is interposed in the center of the partition member. The disc-shaped movable plate is elastically supported. And the needle | mover extended from the linear actuator is connected with the center part of the movable board.

In this type of vibration isolator, for example, when a low frequency vibration (for example, engine shake) having a relatively low frequency of 10 to 15 Hz is input, liquid flows or resonates in the restricted passage, so that The spring constant is reduced and low frequency vibration is effectively absorbed.
When the frequency of the input vibration rises and the restriction passage becomes clogged, the movable plate facing the main liquid chamber is vibrated by the linear actuator, and the pressure in the main liquid chamber rises, that is, the dynamic spring constant of the vibration isolator. The rise of the is suppressed. Thereby, for example, an increase in the dynamic spring constant when an idle vibration having a frequency of 20 to 40 Hz, for example, a vibration that becomes a booming sound exceeding 40 Hz and less than 100 Hz, for example, a high frequency vibration having a frequency of 100 to 200 Hz is suppressed.

JP-A-2005-155585

Although the movable plate is supported by an elastic body, the rigidity of the elastic body is closely related to the active performance of the vibration isolator, and the rigidity is optimized according to the required performance.
On the other hand, the rigidity of the elastic body supporting the movable plate also affects the passive performance of the vibration isolator. The elastic body supporting the movable plate also has a function of suppressing the pressure increase in the main liquid chamber by elastically deforming according to vibration when the restriction passage becomes clogged. If the rigidity is lowered, the elastic film is deformed when low-frequency vibration is input, and the amount of liquid flowing back and forth between the main liquid chamber and the sub liquid chamber is reduced, and there is a problem that the damping performance is lowered. Further, when the rigidity of the elastic body supporting the movable plate is increased, the dynamic spring constant in the frequency region where idling vibrations and booming noises are increased, and there is a problem that the vibration isolation performance is lowered.
As another problem, when the temperature of the vibration isolator rises due to heat from the engine or the like, the air in the storage chamber containing the actuator expands and presses the movable plate and the elastic body supporting the movable plate, The movement of the movable plate could be adversely affected. If the movement of the movable plate is affected, it naturally affects the vibration isolation characteristics (active performance). Further, when the elastic body supporting the movable plate is pressed, a tensile stress acts on the elastic body, and the elastic body becomes easy to stick.
The present invention has been made in consideration of the above-mentioned facts, and a first object of the present invention is to provide a vibration isolator capable of improving vibration absorption performance in a frequency region that is mainly idle vibration and noise. .
A second object is to suppress the deterioration of the vibration-proof characteristic due to the temperature change and the settling of the elastic body that supports the movable plate.

  The vibration isolator according to claim 1 includes a first mounting member connected to one of the vibration generating unit and the vibration receiving unit, and a second mounting member connected to the other of the vibration generating unit and the vibration receiving unit. A first elastic body that connects the first mounting member and the second mounting member and is deformed by vibration input from a vibration generating portion; and a liquid that is sealed and the first elastic body is deformed. A pressure receiving chamber that expands and contracts due to the pressure, a movable plate having one surface facing the pressure receiving chamber, an actuator that is disposed on the other surface side of the movable plate and vibrates the movable plate, and the movable plate is disposed inside. A partition member disposed between the actuator and the pressure receiving chamber, the opening and the movable plate are coupled, and the movable plate is elastically supported with respect to the partition member. 2 provided to close the hole formed in the elastic body and the partition member Is, a, a movable film one surface facing the pressure receiving chamber.

Next, the operation of the vibration isolator according to claim 1 will be described.
When the vibration isolator according to claim 1 is used, for example, for vibration isolation of an automobile engine, the automobile engine is supported on a vehicle body by a plurality of vibration isolators. When the first mounting member of the vibration isolator is connected to the automobile engine that is the vibration generation source, and the second mounting member is connected to the vehicle body that is the vibration receiving portion, the vibration is the first mounting member and the first elastic body. And supported by the vehicle body via the second mounting member. At this time, the vibration is absorbed by the resistance based on the internal friction of the first elastic body.
Here, in the vibration isolator according to the first aspect, since the second elastic body and the movable film face the pressure receiving chamber, vibrations of a desired frequency, for example, idle vibration, and booming noise, By setting the second elastic body and the rigidity (area, thickness, rubber hardness, etc.) of the second elastic body and the movable film so as to vibrate according to the change in the fluid pressure of the pressure receiving chamber at the time of vibration input in the frequency domain, In addition, the second elastic body and the movable plate can vibrate at the time of vibration input in a frequency region that causes a booming sound, and an increase in the dynamic spring constant of the vibration isolator can be suppressed. That is, in the vibration isolator according to the first aspect, the passive performance at the time of vibration input in the frequency region that becomes idle vibration and booming noise can be improved by the vibration of the second elastic body and the movable film.

In the vibration isolator according to the first aspect, the dynamic spring constant can be minimized by exciting the movable plate by the actuator and controlling the picture pressure in the pressure receiving chamber. That is, in the vibration isolator according to the first aspect, the active performance can be obtained by the vibration of the movable plate.
According to a first aspect of the present invention, there is provided an anti-vibration device according to the second aspect of the present invention, wherein the second elastic body and the movable film increase suppression effect of the dynamic spring constant and the dynamic spring constant reduction effect of the movable plate, It becomes possible to effectively absorb the vibration in the high frequency region that becomes sound.

  Furthermore, since the vibration isolator according to claim 1 includes a movable film facing the pressure receiving liquid chamber separately from the second elastic body that supports the movable plate, the second elastic body that supports the movable plate. The rigidity of the movable film can be set with emphasis on the active performance, and the rigidity of the movable film can be set with emphasis on the passive performance, so that both the active performance and the passive performance can be achieved.

  Further, for example, when the temperature of the vibration isolator rises due to heat from the engine, the air in the vibration isolator expands. When the actuator is disposed in a sealed space, when the air in the space expands, the movable plate and the second elastic body are pressed, adversely affect the movement of the movable plate, and the vibration-proof characteristics deteriorate. Although there is a possibility, in the vibration isolator according to claim 1, the movable film is deformed to the pressure receiving chamber side so that the pressure increase in the space is suppressed, and the pressure acting on the movable plate and the second elastic body is reduced. Therefore, the deterioration of the anti-vibration characteristics (active performance) can be suppressed. Further, since unnecessary tension does not act on the second elastic body, the settling of the second elastic body can be suppressed.

  According to a second aspect of the present invention, in the vibration isolator of the first aspect, the movable film is formed by a part of the second elastic body.

Next, the operation of the vibration isolator according to claim 2 will be described.
In the vibration isolator according to claim 2, since the movable film is formed by the second elastic body that supports the movable plate, a dedicated elastic body for forming the movable film (a different type from the second elastic body) ) And the type of elastic body used in the vibration isolator can be minimized.
In addition, the movable plate and the partition member are loaded into the mold, and the second elastic body is vulcanized and bonded thereto, whereby the configuration for supporting the movable plate with respect to the partition member and the formation of the movable film can be performed simultaneously. The movable plate, the partition member, the portion connecting the movable plate and the partition member (second elastic body), and the movable film (second elastic body) can be unitized, and the assembly process of the vibration isolator can be efficiently performed. Can be

  According to a third aspect of the present invention, in the vibration isolator according to the first or second aspect, the actuator is housed in a sealed housing chamber having the partition member as a part of a partition wall.

Next, the operation of the vibration isolator according to claim 3 will be described.
Since the actuator is stored in the sealed storage chamber, moisture or the like does not enter the storage chamber from the outside, and the occurrence of malfunction of the actuator due to moisture or the like can be prevented.
Further, for example, even when the temperature of the vibration isolator rises due to heat from the engine and the air in the storage chamber expands, the movable film is deformed to the pressure receiving chamber side, so that the pressure increase in the storage chamber is suppressed, and the movable plate The unnecessary pressure acting on the second elastic body is reduced, and the deterioration of the vibration-proof characteristic (active performance) due to the temperature change and the settling of the second elastic body are suppressed.

  According to a fourth aspect of the present invention, in the vibration isolator according to any one of the first to third aspects, the pressure receiving liquid chamber is connected to the sub liquid chamber via a restriction passage.

Next, the operation of the vibration isolator according to claim 4 will be described.
By connecting the pressure receiving chamber to the sub liquid chamber through the restriction passage, when the vibration is input and the first elastic body is elastically deformed to expand and contract the pressure receiving chamber, the internal liquid is connected to the pressure receiving chamber through the restriction passage. The anti-vibration effect can be improved when the actuator is not used due to the passage resistance or the liquid column resonance when the internal liquid moves back and forth between the sub liquid chambers and the internal liquid.

As described above, since the vibration isolator according to claim 1 has the above configuration, it has an excellent effect that the vibration absorption performance in the high frequency region can be improved. Moreover, the deterioration of active performance and the settling of the second elastic body can be suppressed.
Since the vibration isolator according to claim 2 is configured as described above, the types of elastic bodies used in the vibration isolator can be minimized.
Since the vibration isolator according to claim 3 has the above-described configuration, it is possible to prevent the actuator from being deteriorated or damaged due to moisture or the like.
Moreover, since the vibration isolator according to claim 4 has the above-described configuration, a high vibration isolating effect can be obtained even when the actuator is not used.

It is a sectional side view which shows the structure of the vibration isolator which concerns on embodiment of this invention. It is the sectional side view rotated 90 degree | times from the state of FIG. 1 which shows the structure of the vibration isolator which concerns on embodiment of this invention. It is a disassembled perspective view which shows the structure of the actuator which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the actuator periphery which concerns on embodiment of this invention. It is a perspective view of the outer peripheral board part which concerns on embodiment of this invention, and a movable board part. It is the graph which showed the vibration proof characteristic.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an actuator and a vibration isolator according to the present invention will be described with reference to the drawings.
1 and 2 show a vibration isolator 10 according to an embodiment of the present invention. The vibration isolator 10 is applied as an engine mount that supports an engine that is a vibration generating unit in an automobile to a vehicle body that is a vibration receiving unit. In addition, the code | symbol S in a figure shows the axial center of an apparatus, and demonstrates the following description by making the direction along this axial center into the axial direction S of an apparatus.

  As shown in FIG. 1, the vibration isolator 10 connects a first attachment member 12 attached to the engine side, a second attachment member 20 attached to the vehicle body side, and the first attachment member 12 and the second attachment member 20. A rubber elastic body 16 is provided.

The second mounting member 20 includes an outer cylinder 22 and an intermediate cylinder 24. The outer cylinder 22 includes a cylindrical portion 22A having a substantially cylindrical shape, a flange portion 22B extending radially outward from one end of the cylindrical portion 22A, an end portion of the intermediate cylinder 24 on the other end side of the cylindrical portion 22A, and will be described later. A caulking portion 22C for caulking and fixing the sealing plate 40 or the like is provided. The intermediate cylinder 24 has a substantially cylindrical shape having a smaller diameter than the cylindrical portion 22 </ b> A, and is coaxially disposed on the radially inner side of the outer cylinder 22. One end side of the intermediate cylinder 24 is a curved portion 24A that is slightly curved radially outward, and the other end side is a stepped flange portion 24B that is bent radially outward. A bolt hole 22 </ b> H for connection with the rebound stopper fitting 13 is drilled in the flange portion 22 </ b> B of the outer cylinder 22. As shown in FIG. 1, the rebound stopper fitting 13 has a rubber material 13A disposed on the inner side of a top portion that is curved in a substantially U shape, and is fixed to the second attachment member 20 by a bolt 13C at the attachment portion 13B. Yes. The rebound stopper fitting 13 is disposed so as to surround the upper outer side of the vibration isolator 10. The rebound stopper fitting 13 is not shown in the drawings other than FIG.
The second mounting member 20 is connected to a vehicle body (not shown) as a vibration receiving portion via a leg member 96 described later.

The first mounting member 12 has a substantially cylindrical shape whose outer diameter is smaller than the inner diameter of the second mounting member 20, is coaxial with the second mounting member 20, and is axially S more than the second mounting member 20. It is arranged to protrude outward. The second mounting member 20 side of the first mounting member 12 has a substantially tapered shape so that the diameter decreases toward the tip. The first attachment member 12 is connected to an engine (not shown) by an attachment portion (not shown).

  The rubber elastic body 16 is vulcanized and bonded to the outer periphery of the small diameter end of the first mounting member 12 and vulcanized and bonded so as to cover the outer peripheral side of the curved portion 24A on the inner periphery of the intermediate tube 24 on the curved portion 24A side. The first mounting member 12 and the intermediate cylinder 24 are elastically connected. A concave portion 16 </ b> A is formed on the lower surface of the rubber elastic body 16 (the surface on the second attachment member 20 side). A thin upper film 17 that covers the outer peripheral surface of the first mounting member 12 is integrally formed with the rubber elastic body 16. The rubber elastic body 16 is integrally formed with a thin lower film 18 that extends toward the stepped flange portion 24 </ b> B of the intermediate cylinder 24 and covers the inner peripheral surface of the intermediate cylinder 24.

  A diaphragm 30 is vulcanized and bonded to the inside of the cylindrical portion 22 </ b> A of the outer cylinder 22. The diaphragm 30 is made of a thin rubber film and has a substantially cylindrical shape. One end of the cylinder of the diaphragm 30 is bent inward in the radial direction and reduced in diameter, and is vulcanized and bonded to the ring 34. The ring 34 is externally fitted to the first attachment member 12 via the upper film 17. The other end of the cylinder of the diaphragm 30 constitutes a coating film 32 that extends toward the caulking portion 22C of the outer cylinder 22 and covers the inner peripheral surface of the cylindrical portion 22A.

  A sealing plate 40 is disposed on the opposite side of the second mounting member 20 from the first mounting member 12. A main liquid chamber 36 as a pressure receiving chamber is configured by being surrounded by the recess 16A of the rubber elastic body 16, the intermediate cylinder 24, and the sealing plate 40. Between the rubber elastic body 16 and the diaphragm 30, an auxiliary liquid chamber 38 is formed in an annular shape. A restriction passage 26 is formed between the outer cylinder 22 and the intermediate cylinder 24 which are the outer peripheral sides of the main liquid chamber 36. The restriction passage 26 has one end communicating with the main liquid chamber 36 and the other end communicating with the sub liquid chamber 38, and the main liquid chamber 36 and the sub liquid chamber 38 are communicated with each other through the restriction passage 26. The main liquid chamber 36, the sub liquid chamber 38, and the restriction passage 26 are filled with liquid.

  When vibration in the axial direction S is input from the side of the first mounting member 12 connected to the engine, the rubber elastic body 16 is elastically deformed, and the internal volume of the main liquid chamber 36 is expanded and contracted with this elastic deformation. As a result, vibrations in a relatively low frequency range among vibrations input from the engine, such as shake vibrations, are input into the main liquid chamber 36 due to a pressure difference between the main liquid chamber 36 and the sub liquid chamber 38. The liquid and the liquid sealed in the sub liquid chamber 38 circulate through each other through the restriction passage 26, and a vibration damping effect and a vibration isolation effect can be obtained by a liquid column resonance action in the restriction passage 26. The restriction passage 26 is set so that its path length and cross-sectional area can effectively exert a damping effect in a frequency range of low-frequency large-amplitude vibration such as engine shake.

The sealing plate 40 is generally disc-shaped as a whole, an annular outer peripheral plate portion 42 having a circular opening 41 formed in the center, a movable plate portion 44 disposed inside the opening 41, and an outer peripheral plate An annular rubber portion 46 that connects the portion 42 and the movable plate portion 44 is included. The outer peripheral plate portion 42 is bent at the outer peripheral end downward, and is caulked together with the stepped flange portion 24 </ b> B of the intermediate cylinder 24 and fixed to the second mounting member 20. Further, the outer peripheral plate portion 42 is bent upward so that the inner peripheral end has a cylindrical shape.
Note that the outer peripheral plate portion 42 of the present embodiment is a press-formed product made of a metal plate.
A connecting concave portion 44 </ b> A for inserting and connecting a shaft member 54 of an actuator 50 to be described later is formed in the central portion of the movable plate portion 44. The movable plate portion 44 is elastically supported on the outer peripheral plate portion 42 by the rubber portion 46. In addition, the outer peripheral end of the movable plate portion 44 is bent upward.

As shown in FIGS. 4 and 5, a movable film forming window 47 is formed on the outer peripheral plate portion 42 on the radially outer side of the opening 41. The movable film forming window 47 is an arc-shaped long hole, and the center of the radius of curvature thereof coincides with the center of the outer peripheral plate portion 42. In the present embodiment, three movable film forming windows 47 are arranged so as to surround the opening 41.
The rubber part 46 is vulcanized and bonded to the outer side in the radial direction from the opening 41 along the upper and lower surfaces of the outer peripheral plate part 42 and closes the movable film forming window 47. The closed portion is configured as a movable film 49 that is elastically deformed by a change in the hydraulic pressure of the main liquid chamber 36.

As shown in FIGS. 1 to 3, an actuator 50 is disposed on the side opposite to the main liquid chamber 36 of the sealing plate 40. The actuator 50 includes a mover 52 that reciprocates in the axial direction S, and a stator 60 that supports the mover 52.
The actuator 50 of the present embodiment operates on the same principle as the linear actuator disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-343964, but a linear motion type actuator in which the mover reciprocates linearly. As long as the actuator operates according to another principle, for example, an electromagnetic solenoid type, a moving coil (voice coil motor) type, or a moving magnet type may be used.

(Configuration of actuator)
1-4, the needle | mover 52 is provided with the shaft-shaped shaft member 54 and the disk-shaped overhang | projection parts 56 and 58. As shown in FIG. The shaft member 54 is disposed along the axial direction S, and the upper end 54 </ b> A is coupled to the coupling recess 44 </ b> A of the movable plate portion 44. The overhang portions 56 and 58 are fixed to an intermediate portion of the shaft member 54 so as to be coaxial with the shaft member 54 and spaced apart from each other. The overhang portions 56 and 58 are configured by laminating a plurality of metal plates that are magnetic metals such as electromagnetic steel plates.

The stator 60 is disposed so as to surround the outer periphery of the mover 52 and includes a yoke part 62, a coil part 64, and a magnetic pole part 67.
The yoke portion 62 is annular, and a hollow portion 62A is configured. The mover 52 is inserted through the center of the hollow portion 62A. The yoke portion 62 is configured by laminating a plurality of annular metal plates made of a magnetic metal such as an electromagnetic steel plate. The yoke portion 62 is formed with convex portions 63A and 63B that protrude radially inward from positions facing each other. The tips (inner ends) of the convex portions 63A and 63B are formed in an arc shape along the overhang portions 56 and 58, and the permanent magnets 66 (66A and 66B) are fixed to form the magnetic pole portion 67. .

Two sets of permanent magnets 65A and 65B arranged in the axial direction S are fixed at positions facing the protruding portions 56 of the convex portions 63A and 63B. The two sets of permanent magnets 65A and 65B are arranged so that the magnetic poles are NS different from each other. In addition, two sets of permanent magnets 66A and 66B arranged in the axial direction S are fixed to the lower side (the side far from the sealing plate 40) of the two sets of permanent magnets 65A and 65B of the convex portions 63A and 63B. . The two sets of permanent magnets 66A and 66B are arranged such that the magnetic poles have NS alternating different polarities, and the adjacent permanent magnets 65B and 66A have magnetic poles having NS alternating different polarities. Yes. That is, in the magnetic pole portion 67, four sets of permanent magnets 65A, 65B, 66A, and 66B are arranged in the axial direction S so that the magnetic poles are NS different from each other.

Note that the length from the upper end of the permanent magnet 65A to the lower end of the permanent magnet 65B is longer than the length of the protruding portion 56 in the vertical direction (axial direction S). The length from the upper end of the permanent magnet 66A to the lower end of the permanent magnet 66B is also longer than the length of the overhanging portion 58 in the vertical direction (axial direction S).

A heat radiating member 70 is fixed to the upper end (on the sealing plate 40 side) of the yoke portion 62 in the axial direction S. The heat radiating member 70 includes a cylindrical cylindrical portion 71, a flange portion 72 extending radially outward on one end side of the cylindrical portion 71, and a bottom portion 73 constituting a bottom surface on the other end side of the cylindrical portion 71, These are integrally formed. The bottom 73 has an opening 73A.

The heat radiating member 70 is fixed to the yoke portion 62 by inserting pins 76 and 77 into a blind hole 73 </ b> H drilled in the bottom portion 73. The outer diameter of the cylindrical portion 71 is substantially the same as the inner diameter of a bracket 82 described later, and is press-fitted into the bracket 82. By this press-fitting, the stator 60 is fixed to the bracket 82 while being positioned with respect to the bracket 82 via the heat radiation member 70.

The mover 52 is elastically supported by a pair of upper and lower leaf springs 90, 90 so as to reciprocate in the axial direction S with respect to the stator 60. The leaf springs 90 and 90 include a central ring portion 92 and a pair of outer peripheral annular portions 94 and 94. The central ring portion 92 is engaged with and supported by a support groove 54 </ b> M formed in the shaft member 54. The pair of outer peripheral annular portions 94, 94 is formed in a rectangular deformed ring shape that extends from the central ring portion 92 and bypasses a coil member 64 described later. The upper peripheral annular portion 94 is attached to the groove 77M of the pin 77 so as to be spaced apart from the heat dissipation member 70 in the axial direction S by a predetermined distance. The lower outer peripheral annular portion 94 is attached to the pin 77 so as to be separated from the lower surface of the yoke portion 62 by a predetermined distance in the axial direction S.

A coil member 64 is disposed in the hollow portion 62 </ b> A of the yoke portion 62. The coil member 64 has a pair of coil portions 78A and 78B in which a coil is wound around each of the convex portions 63A and 63B of the yoke portion 62. The pair of coil portions 78A and 78B are connected by a connecting portion 79. Therefore, the coil portions 78A and 78B are configured to be able to generate a magnetic flux in the direction in which the four sets of permanent magnets 65A, 65B, 66A, and 66B face each other. A connector 80 is formed in the coil portion 78 </ b> A, and the coil is energized through the connector 80.

The actuator 50 is accommodated in the bracket 82. The bracket 82 has a bottomed cylindrical shape, and has a cylindrical cylindrical portion 84 with the bracket 82 disposed inside, a bottom portion 86 that closes one end side of the cylindrical portion 84, and an opening on the other end side of the cylindrical portion 84. A flange portion 88 extending outward in the direction is provided. The heat radiating member 70 is press-fitted from the bottom 73 side to the flange portion 88 side of the bracket 82, and the flange portion 72 of the heat radiating member 70 is disposed on the bracket 82. A stopper rubber 92 is provided at a position corresponding to the shaft member 54 of the bottom portion 86. The bracket 82 and the heat radiating member 70 form a storage chamber for the actuator 50.

In the actuator 50, when an alternating current is applied to the coil portions 78 </ b> A and 78 </ b> B, the magnetic force of the coil portions 78 </ b> A and 78 </ b> B and the magnetic force of the magnetic pole portion 67 interact to alternately apply a vertical force to the mover 52. Make it work. As a result, the mover 52 supported by the leaf spring 90 reciprocates in the axial direction S.

The bracket 82 is accommodated in the leg member 96. The leg member 96 includes a cylindrical cylindrical portion 96A, a tapered leg portion 96B having a large diameter from the lower end to the lower side of the cylindrical portion 96A, and a flange extending radially outward from the upper end of the cylindrical portion 96A. A portion 96C is provided. The flange portion 88 is arranged on the flange portion 96C, and the flange portion 72, the outer peripheral plate portion 42, and the stepped flange portion 24B are sequentially stacked on the flange portion 96C, and these are sandwiched between the caulking portions 22C and fixed by caulking. .

(Function)
Below, the effect | action of the vibration isolator 10 of this embodiment is demonstrated.
In the vibration isolator 10 of the present embodiment, vibration from the automobile engine is supported on the vehicle body via the first mounting member 12, the rubber elastic body 16, and the second mounting member 20. At this time, the vibration is absorbed by the resistance based on the internal friction of the rubber elastic body 16.

When vibration having a relatively low frequency (for example, frequency of 10 to 15 Hz) such as engine shake is inputted, the vibration is transmitted to the rubber elastic body 16, whereby the rubber elastic body 16 is elastically deformed and the main liquid chamber 36 is elastically deformed. Expands and contracts, the internal liquid moves between the main liquid chamber 36 and the sub liquid chamber 38 via the restriction passage 26, and vibrates due to passage resistance or liquid column resonance when the internal liquid moves back and forth through the restriction passage 26. Is absorbed.

When the frequency of vibration increases, the restriction passage 26 becomes clogged. When the restriction passage 26 is clogged, the hydraulic pressure in the main liquid chamber 36 increases, and as a result, the dynamic spring constant of the vibration isolator 10 increases and the vibration isolation performance decreases.

The graph of FIG. 6 shows an example of the passive performance of the vibration isolator (performance when the movable plate portion is not vibrated), with the horizontal axis representing the vibration frequency and the vertical axis representing the dynamic spring constant.
In this graph, the solid line indicates the passive performance of the vibration isolator when the rubber part 46 and the movable film 49 are not provided, and the dotted line indicates the case where the rubber part 46 is provided and the movable film 49 is not provided. The passive performance of the vibration isolator is shown, and the alternate long and short dash line indicates the passive performance of the vibration isolator when the rubber portion 46 and the movable film 49 are provided.
As can be seen from this graph, the vibration isolator including the rubber part 46 and the movable film 49 is, for example, an engine shake having a frequency of 10 to 15 Hz, a frequency range higher than the riding comfort region (idle to booming sound: for example, frequency In the case where the rubber part 46 and the movable film 49 are not provided, and the case where the rubber part 46 is provided and the movable film 49 is not provided, the dynamic spring constant can be lowered. ing. In addition, by adjusting the rigidity of the rubber part 46 and the movable film 49, it is also possible to suppress an increase in the dynamic spring constant in a part of the high-frequency region (the lower frequency side close to the noise in the high-frequency region). .

Furthermore, in the vibration isolator 10 of the present embodiment, by controlling the hydraulic pressure in the main liquid chamber 36 by vibrating the movable plate portion 44 in a direction in which the vibration transmission force to the vehicle body becomes zero by a control device (not shown), When the restriction passage 26 is clogged, for example, high-frequency vibration that prevents liquid from flowing through the restriction passage 26 (for example, from idling vibration with a frequency of 20 to 40 Hz to high-frequency vibration with a frequency of 100 to 200 Hz). The rise of the dynamic spring constant when the is input can be suppressed.
Therefore, in the vibration isolator 10 of the present embodiment, in addition to the effect of reducing the dynamic spring constant by the rubber part 46 and the movable film 49, the dynamic spring constant by further vibrating the movable plate part 44 facing the main liquid chamber 36 is increased. By adding a reduction effect, it is possible to effectively reduce the dynamic spring constant when high-frequency vibration that causes the restriction passage 26 to be clogged is input, thereby obtaining high vibration isolation performance.
Further, in the vibration isolator 10 of the present embodiment, when high-frequency vibration that causes the restriction passage 26 to be clogged is input, in addition to the effect of suppressing the increase of the dynamic spring constant by the rubber portion 46, the movement by the movable film 49 is performed. Since the spring constant increase suppressing effect is added, the role of the movable plate portion 44 can be relatively reduced to reduce the work amount of the actuator 50. Thereby, the power consumption of the actuator 50 can be reduced and it can contribute to a fuel consumption improvement.

Further, in the vibration isolator 10 of the present embodiment, since the actuator 50 is housed in a sealed space formed by the bracket 82 and the outer peripheral plate portion 42, water, moisture, etc. are externally provided in the space. There is no intrusion, the occurrence of malfunction of the actuator due to moisture or the like can be prevented, and the durability of the actuator 50 is ensured.
The temperature of the vibration isolator 10 rises due to the heat from the engine, and the air in the space may expand, but the pressure in the space increases due to the movable film 49 being deformed to the pressure receiving chamber side. As a result, unnecessary pressure is not applied to the movable plate portion 44 and the rubber portion 46, so that deterioration of the vibration isolation characteristics is suppressed, and the settling of the rubber portion 46 that supports the movable plate portion 44 is suppressed.

  Further, in the vibration isolator 10 according to the present embodiment, the movable film 49 is provided in a vacant space outside the opening 41 in the outer peripheral plate portion 42 and the space is effectively used. It is not necessary to forcibly provide the movable film 49 to the members such as 22 and the intermediate cylinder 24. If the movable film 49 is provided on the members such as the outer cylinder 22 and the intermediate cylinder 24, the anti-vibration characteristics at the time of low-frequency vibration input are affected by the effect that the size of the restriction passage 26 is shortened.

Furthermore, in the vibration isolator 10 of the present embodiment, the outer peripheral plate portion 42, the movable plate portion 44, the rubber portion 46 that connects the outer peripheral plate portion 42 and the movable plate portion 44, and the rubber that forms the movable film 49. Since the unit 46 is integrated and unitized, the assembly process is made efficient, and the type of rubber used in the vibration isolator 10 can be minimized.
Further, the vibration isolator 10 of the present embodiment is provided with a rubber portion 46 (a portion connecting the outer peripheral plate portion 42 and the movable plate portion 44) and a movable film 49 so as to face the main liquid chamber 36. Therefore, the rigidity of the rubber part 46 supporting the movable plate part 44 can be set with emphasis on active performance, the rigidity of the movable film 49 can be set with emphasis on passive performance, and both the active performance and the passive performance can be achieved. it can.

10 Vibration isolator 12 Mounting member (first mounting member)
16 Rubber elastic body (first elastic body)
22 Outer cylinder (second mounting member)
26 Restricted passage 36 Main liquid chamber (pressure receiving chamber)
38 Secondary liquid chamber 41 Opening
42 Peripheral plate (partition member)
44 Movable plate (movable plate)
46 Rubber part (second elastic body)
47 Movable film forming window (hole)
49 Movable membrane 50 Actuator 52 Movable element 96 Leg member (second mounting member)

Claims (4)

A first attachment member coupled to one of the vibration generator and the vibration receiver;
A second attachment member coupled to the other of the vibration generating portion and the vibration receiving portion;
A first elastic body that connects the first mounting member and the second mounting member, and is deformed by vibration input from a vibration generating unit;
A pressure receiving chamber that encloses a liquid and expands and contracts by deformation of the first elastic body;
A movable plate having one surface facing the pressure receiving chamber;
An actuator arranged on the other surface side of the movable plate to vibrate the movable plate;
An opening for disposing the movable plate on the inside, and a partition member disposed between the actuator and the pressure receiving chamber;
A second elastic body that connects the opening and the movable plate, and elastically supports the movable plate with respect to the partition member;
A movable membrane that is provided so as to close a hole formed in the partition member, and whose one surface faces the pressure receiving chamber;
Anti-vibration device with   The vibration isolator according to claim 1, wherein the movable film is formed of a part of the second elastic body.   The vibration isolator according to claim 1 or 2, wherein the actuator is housed in a sealed housing chamber in which the partition member is a part of a partition wall.   The vibration isolator according to any one of claims 1 to 3, wherein the pressure receiving chamber is connected to a sub liquid chamber via a restriction passage.

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