JP6570979B2 - Vibration isolator - Google Patents

Description

  The present invention relates to a vibration isolator.

Conventionally, a cylindrical first attachment member connected to the vibration receiving portion, a second attachment member connected to the vibration generating portion, and an elastic body that elastically connects the first and second attachment members to each other. A diaphragm that is spaced apart from the elastic body in the axial direction along the central axis of the first mounting member, and that defines a liquid chamber between the elastic body and the liquid chamber. A partition member that divides the pressure receiving liquid chamber as a part and a sub liquid chamber having a diaphragm as a part of the wall surface, the partition member extending in a circumferential direction around the central axis, and the pressure receiving liquid chamber. An anti-vibration device having a restriction passage communicating with a sub liquid chamber is known.
As this type of vibration isolator, for example, as shown in Patent Document 1 below, among inner wall surfaces defining a restriction passage, they face each other in a radial direction perpendicular to the central axis in a plan view viewed from the axial direction. A configuration is known in which a plurality of streamline changing protrusions having a substantially triangular shape in a plan view as viewed from the axial direction are formed on a pair of opposing surfaces so as to be positioned in a staggered manner in the circumferential direction.
In this vibration isolator, the liquid flowing through the restricted passage is made into a turbulent state by the streamline changing projection, thereby increasing the flow resistance of the liquid, so that the damping action can be exerted in a wide frequency band. .

JP 2011-241928 A

  However, the conventional vibration isolator has a problem that it is difficult to complicately disturb the flow of liquid flowing in the restricted passage, and it is difficult to expand a frequency band that exhibits a damping action.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vibration isolator that can complicately disturb the flow of liquid flowing in the restricted passage.

In order to solve the above-described problems and achieve such an object, the vibration isolator of the present invention includes a cylindrical first mounting member coupled to one of a vibration generating unit and a vibration receiving unit, And a second attachment member connected to the other, an elastic body elastically connecting the first and second attachment members, and one of the axial directions from the elastic body along the central axis of the first attachment member And a diaphragm defining a liquid chamber between the elastic body and the pressure chamber, the pressure receiving liquid chamber having the elastic body as a part of the wall surface, and the diaphragm being disposed on the wall surface. A partition member that divides into a sub liquid chamber as a part, and a vibration isolator in which a restriction passage that connects the pressure receiving liquid chamber and the sub liquid chamber is formed in the partition member, The restriction passage is formed with an extended portion having a groove width wider than other portions, The groove width of the tension portion is along the direction orthogonal to the groove width direction in a cross-sectional view along the direction orthogonal to the flow direction of the liquid traveling between the pressure receiving liquid chamber and the sub liquid chamber in the restriction passage. The expansion portion gradually increases in size from one end portion toward the other end portion, and the expansion portion is formed on one end portion of the restriction passage that opens toward the pressure receiving liquid chamber and toward the sub liquid chamber. It arrange | positions in the middle position between the other edge part which opens, It is characterized by the above-mentioned.

  According to the present invention, not only is the extension portion formed in the restriction passage wider than the other portion, but also the groove width of the extension portion is in a direction perpendicular to the groove width direction in the cross-sectional view. A part of the inner wall surface of the extension portion is inclined so as to gradually increase from one end portion to the other end portion, so that liquid initially enters the extension portion in the process of flowing through the restricted passage. In addition, it is possible to easily generate turbulent flow due to the above-mentioned inclined inner wall surface in the process of circulating in the expansion part, and it is easy to complicate the flow of liquid flowing in the expansion part in a complicated manner. Can be realized. Therefore, the flow resistance of the liquid in the restriction passage is reliably increased, and the frequency band that exhibits the damping action can be easily expanded.

Here, the partition member includes a substrate portion whose front and back surfaces are directed in the axial direction, and the restriction passage extends in a circumferential direction around the central axis and is formed on the front surface or the back surface of the substrate portion. In the restriction passage, the extension portion is formed to have a larger radial size perpendicular to the central axis in a plan view as viewed from the axial direction than the other portion, and the groove width direction. Coincides with the radial direction, and among the inner wall surfaces of the extension portion, at least one of the pair of side wall surfaces facing the radial direction gradually increases from one end portion to the other end portion along the axial direction. You may incline so that it may space apart from the other.
In this case, it is possible to reliably obtain a vibration isolator that can complicately disturb the flow of the liquid flowing through the expansion portion.
The expansion portion may be disposed in a central portion between the one end portion and the other end portion in the restriction passage.

  According to this invention, the flow of the liquid flowing through the restricted passage can be complicated.

It is a top view of a vibration isolator shown as one embodiment concerning the present invention. FIG. 2 is a cross-sectional view of the vibration isolator shown in FIG. FIG. 3 is a cross-sectional view of the vibration isolator shown in FIG. It is a perspective view of the partition member in the vibration isolator shown in FIGS. It is a top view of the partition member in the vibration isolator shown in FIGS.

Hereinafter, an embodiment of a vibration isolator according to the present invention will be described with reference to FIGS.
The vibration isolator 1 includes a cylindrical first mounting member 11 connected to one of the vibration generating unit and the vibration receiving unit, a second mounting member 12 connected to the other, and the first of these. A first elastic body (elastic body) 13 that elastically connects the second mounting members 11, 12, and the first elastic body 13 away from one side in the axial direction along the central axis O of the first mounting member 11. And a diaphragm 14 that defines a liquid chamber 15 between the first elastic body 13 and a first pressure-receiving liquid chamber (with the first elastic body 13 as a part of a wall surface). A partition member 18 that divides the pressure receiving liquid chamber 16 into a sub-liquid chamber 17 having the diaphragm 14 as a part of the wall, and the first and second mounting members 11 and 12 are elastically connected to each other, and the first elastic member A second elastic body 19 disposed on the other side in the axial direction from the body 13, Between the elastic body 13 and the second elastic body 19, two second pressure receiving liquid chambers 21 having both the elastic bodies 13 and 19 as part of the wall surface are defined, and the partition member 18 receives the first pressure receiving pressure. A first restriction passage (restriction passage) 22 that communicates between the liquid chamber 16 and the sub liquid chamber 17, and two second restriction passages 23 that communicate between the two second pressure receiving liquid chambers 21 and the sub liquid chamber 17, respectively. , Is formed.

  Hereinafter, the one side in the axial direction is referred to as the lower side, the other side in the axial direction is referred to as the upper side, and the direction orthogonal to the central axis O in the plan view of the vibration isolator 1 viewed from the axial direction is the diameter. A direction that goes around the central axis O is called a circumferential direction.

  As shown in FIG. 3, the first attachment member 11 is formed in a multistage cylindrical shape that gradually decreases in diameter from the upper side toward the lower side. Further, as shown in FIG. 2, openings 11 a penetrating in the radial direction are formed in the first mounting member 11 at positions facing each other across the central axis O in the radial direction. In the illustrated example, two openings 11 a are formed in the first attachment member 11. The opening 11a is located over the entire length in the axial direction of the intermediate portion between the upper end portion and the lower end portion of the first mounting member 11, and is formed in a belt shape extending in the circumferential direction.

  The second attachment member 12 is formed in a rod shape that is disposed coaxially with the central axis O. The second mounting member 12 is disposed on the inner side in the radial direction of the first mounting member 11. A flange portion 12 a that protrudes outward in the radial direction is formed at an intermediate position in the axial direction of the second mounting member 12. Of the flange portion 12a, a portion along the circumferential direction where the opening 11a of the first mounting member 11 is located has a smaller amount of protrusion toward the radially outer side than the other portion. In the illustrated example, as shown in FIG. 1, the flange portion 12 a has a rectangular shape with short sides extending in a direction in which the two openings 11 a face each other in a plan view viewed from the axial direction.

As shown in FIG. 2, the first elastic body 13 is formed in a cylindrical shape whose diameter is gradually reduced from the lower side toward the upper side, the upper end portion thereof being connected to the lower end portion of the second mounting member 12, and the lower end The part is connected to the lower end of the first attachment member 11.
The second elastic body 19 is formed in an annular shape, and its radially inner end is connected to a portion of the outer peripheral surface of the second mounting member 12 that is located directly below the flange portion 12a, and the radially outer end. Is connected to the upper end of the first mounting member 11. The second elastic body 19 is formed thinner than the first elastic body 13. The radially inner end of the second elastic body 19 is connected to the upper end of the first elastic body 13, and the first elastic body 13 and the second elastic body 19 are integrally formed. A connecting portion between the upper end portion of the first elastic body 13 and the inner end portion in the radial direction of the second elastic body 19 is formed in a curved shape that is recessed toward the inner side in the radial direction. In the illustrated example, the radially inner end of the second elastic body 19 is located above the radially outer end of the second elastic body 19.

  In the illustrated example, two second pressure receiving liquid chambers 21 between the first elastic body 13 and the second elastic body 19 are provided, and these second pressure receiving liquid chambers 21 are the first elastic body 13. And two partition walls 24 that partition the annular space between the first elastic body 19 and the second elastic body 19 in the circumferential direction. The partition wall 24 is connected to a portion located between the two openings 11 a adjacent to each other in the circumferential direction in the intermediate portion of the first mounting member 11. The partition wall 24 is formed integrally with the first and second elastic bodies 13 and 19. The two partition walls 24 are arranged in the same straight line in a plan view of the vibration isolator 1 viewed from the axial direction.

  The partition member 18 communicates the accommodating chamber 26 in which the membrane 25 is accommodated, the first communication hole 27 that communicates the accommodating chamber 26 and the first pressure-receiving liquid chamber 16, and the accommodating chamber 26 and the auxiliary liquid chamber 17. A second communication hole 28 is formed. The first restriction passage 22 is formed in the partition member 18 at a portion located on the outer side in the radial direction from the accommodation chamber 26 and the first and second communication holes 27 and 28. As shown in FIGS. 4 and 5, the first restriction passage 22 extends in the circumferential direction and is formed in an annular shape. The second restriction passage 23 is formed on the outer peripheral surface of the partition member 18. In the example shown in the figure, the partition member 18 is formed in a bottomed cylindrical shape, and a storage wall 26, first and second communication holes 27 and 28, and a first restriction passage 22 are formed in the bottom wall portion (substrate portion) 18 a. The lower end part of the 1st attachment member 11 is fitted in the surrounding wall part. Further, the storage chamber 26 and the first and second communication holes 27 and 28 are formed in the central portion in the radial direction of the bottom wall portion 18 a of the partition member 18. The front and back surfaces of the bottom wall portion 18a face the axial direction.

In the present embodiment, the first restricting passage 22 is formed with an expanded portion 33 having a groove width wider than that of other portions, and the groove width of the expanded portion 33 is within the first restricted passage 22. In the cross-sectional view along the direction orthogonal to the flow direction of the liquid that flows between the auxiliary liquid chamber 17 and the auxiliary liquid chamber 17, it gradually increases from one end to the other end along the direction orthogonal to the groove width direction. .
In the illustrated example, as shown in FIG. 3, the expanded portion 33 has the same size in the axial direction and the size in the radial direction as compared with other portions of the first restriction passage 22. It is getting bigger. That is, the groove width direction coincides with the radial direction, and the direction orthogonal to the groove width direction in the sectional view coincides with the axial direction. In addition, the flow direction of the liquid traveling between the first pressure receiving liquid chamber 16 and the sub liquid chamber 17 in the first restriction passage 22 coincides with the circumferential direction.

At least one of the pair of side wall surfaces 33c and 33d facing the radial direction among the inner wall surfaces defining the expansion portion 33 is gradually separated from the other side as it goes from one end portion to the other end portion along the axial direction. Inclined to do. In the illustrated example, of the pair of side wall surfaces 33c and 33d that define the expansion portion 33, the outer wall surface 33c positioned on the outer side in the radial direction is the first pressure receiving liquid from the sub liquid chamber 17 side along the axial direction. As it goes to the chamber 16 side, it is gradually inclined so as to be separated from the inner wall surface 33d. Thereby, the size of the expansion portion 33 in the radial direction is gradually increased from the sub liquid chamber 17 side toward the first pressure receiving liquid chamber 16 side along the axial direction.
In the illustrated example, the inner wall surface 33d extends straight in the axial direction in the cross-sectional view, but the inner wall surface 33d extends from the auxiliary liquid chamber 17 side to the first pressure receiving liquid chamber 16 side along the axial direction. You may make it incline so that it may leave | separate from the outer side wall 33c gradually as it goes to. Further, the size of the expansion portion 33 in the radial direction may be gradually increased from the first pressure receiving liquid chamber 16 side toward the sub liquid chamber 17 side along the axial direction.

As shown in FIG. 5, the expansion portion 33 includes one peripheral end portion 22 a that opens toward the first pressure receiving liquid chamber 16 and the other opening that opens toward the sub liquid chamber 17 in the first restriction passage 22. It is arrange | positioned in the middle position between the peripheral edge part 22b. The expansion part 33 is formed in the central part between the peripheral end parts 22 a and 22 b in the first restriction passage 22.
The groove widths of the peripheral end portions 33a and 33b of the extended portion 33 are gradually increased from the outer side toward the inner side in the circumferential direction of the extended portion 33. In the first restriction passage 22, the peripheral length of the expansion portion 33 is shorter than the peripheral lengths of the other portions. The expansion part 33 extends straight in a plan view of the partition member 18 viewed from the axial direction.
The first restriction passage 22 extends slightly less than two rounds around the central axis O. One peripheral end portion 22 a of the first restriction passage 22 is positioned on the radially inner side from the expanded portion 33, and the other peripheral end portion 22 b is positioned on the radially outer side of the expanded portion 33. Both peripheral end portions 22a and 22b of the first restriction passage 22 are respectively adjacent to both peripheral end portions 33a and 33b of the expansion portion 33 in the radial direction.

Here, in the present embodiment, the outer cylinder 29 is externally fitted integrally with the entire region of the first mounting member 11 except the lower end portion and the peripheral wall portion of the partition member 18. The outer cylinder 29 closes the opening 11a of the first attachment member 11 in a liquid-tight manner. The first attachment member 11 is connected to either one of the vibration generating unit and the vibration receiving unit via the outer cylinder 29.
A diaphragm member 31 formed into a bottomed cylindrical shape by an elastic material is extended downward at the lower end portion of the outer cylinder 29, and the bottom wall portion 18 a of the partition member 18 is fitted into the diaphragm member 31. Has been. A central portion of the bottom portion of the diaphragm member 31 defines a sub liquid chamber 17 and is a diaphragm 14 that expands and contracts as the liquid flows into and out of the sub liquid chamber 17.

Here, as shown in FIG. 3, the two partition walls 24 project from the outer peripheral surface of the first mounting member 11 toward the outer side in the radial direction, and the lower end surface facing downward is located above the partition member 18. The locking projections 35 and 36 that are in contact with the upper end surface that faces are formed separately. Of these locking projections 35 and 36, either one has a larger amount of projection downward than the other. That is, either one of the lower end surfaces of the locking projections 35 and 36 is located below the other lower end surface. Further, the lower end of one locking projection 35 has a shorter circumferential length than the other locking projection 36.
Between the locking projections 35, 36 and the partition wall 24, a portion located between the two openings 11 a adjacent to each other in the circumferential direction in the intermediate portion of the first mounting member 11 is interposed. ing. The locking projections 35 and 36 and the partition wall 24 are connected to each other across the periphery of the opening 11a of the first mounting member 11 and are integrally formed.

As shown in FIGS. 3 and 4, a raised portion 38 that protrudes upward is formed on the upper end surface of the partition member 18.
In the illustrated example, the raised portion 38 is formed at the upper end opening edge of the peripheral wall portion of the partition member 18 and has a C-shape extending in the circumferential direction when viewed from above. In a plan view of the partition member 18 viewed from the axial direction, the raised portion 38 is adjacent to the extended portion 33 in the radial direction.
The raised portions 38 are located on both sides in the circumferential direction and gradually extend upward from the outer side to the inner side in the circumferential direction, and are located between the inclined surfaces 38a and face upward. And a flat surface 38b.
The raised portion 38 is formed with a first support portion 41 that supports the lower end portion of the other locking projection 36, and each opening portion 23 a on the second pressure receiving liquid chamber 21 side in the two second restriction passages 23. Has been.

  The 1st support part 41 is formed in the concave shape by which the lower end part of the other latching protrusion 36 is fitted. A concave second support portion 42 into which the lower end portion of one of the locking projections 35 is fitted is formed at the upper end opening edge of the peripheral wall portion of the partition member 18. The peripheral lengths of the lower end portion of the one locking projection 35 and the second support portion 42 are equal to each other, and the peripheral lengths of the other locking projection portion 36 and the first support portion 41 are equal to each other. . The first support portion 41 and the second support portion 42 penetrate the upper end opening edge of the peripheral wall portion of the partition member 18 in the radial direction.

The opening 23 a of the first support portion 41 and the second restriction passage 23 is formed on the flat surface 38 b of the raised portion 38. The opening 23a of the second restriction passage 23 is disposed on the flat surface 38b of the raised portion 38 with a circumferential interval, and the first support portion 41 is disposed between the openings 23a. Yes. Of the flat surface 38 b of the raised portion 38, each portion where the opening 23 a is formed is a part of each inner surface that defines the two second pressure receiving liquid chambers 21.
The second support portion 42 is disposed on the opposite side of the first support portion 41 that sandwiches the central axis O in the radial direction in the upper end opening edge of the peripheral wall portion of the partition member 18.

  Here, the flow path length and the flow path cross-sectional area of the first restriction passage 22 are set (tuned) so that the resonance frequency of the first restriction passage 22 becomes a predetermined frequency. The channel length and the channel cross-sectional area of the second restriction passage 23 are set (tuned) so that the resonance frequency of the second restriction passage 23 becomes a predetermined frequency. Examples of the predetermined frequency include a frequency of idle vibration (for example, a frequency of 18 Hz to 30 Hz, an amplitude of ± 0.5 mm or less), and a shake vibration having a frequency lower than the idle vibration (for example, a frequency of 14 Hz or less, A frequency of which the amplitude is larger than ± 0.5 mm).

Note that the vibration isolator 1 of the present embodiment is a compression type (positive) that is attached and used so that the first pressure receiving liquid chamber 16 is positioned on the upper side in the vertical direction and the auxiliary liquid chamber 17 is positioned on the lower side in the vertical direction. The composition is vertical.
For example, when the vibration isolator 1 is attached to an automobile, the second attachment member 12 is connected to an engine or the like as a vibration generating unit, while the first attachment member 11 and the outer cylinder 29 are subjected to vibration reception via a bracket (not shown). It is used by being connected to a vehicle body as a part. In an automobile, main vibration along the vertical direction and side vibration along the front-rear direction or the left-right direction of the vehicle body are easily input from the engine to the vehicle body. The vibration isolator 1 is attached such that the direction in which the two second pressure receiving liquid chambers 21 face each other is coincident with, for example, the front-rear direction or the left-right direction, and main vibration is input in the axial direction. The secondary vibration is input in the direction in which the second pressure receiving liquid chambers 21 face each other.

  Next, the operation of the vibration isolator 1 configured as described above will be described.

First, when a main vibration is input from the vibration generating unit, the first mounting member 11 and the second mounting member 12 are relatively displaced in the axial direction while elastically deforming the first elastic body 13.
At this time, for example, the first pressure receiving liquid chamber 16 is expanded or contracted due to relative displacement between the first mounting member 11 and the second mounting member 12, elastic deformation of the first elastic body 13, or the like. At this time, the liquid flows through the first restriction passage 22 between the first pressure receiving liquid chamber 16 and the sub liquid chamber 17, and liquid column resonance occurs in the first restriction passage 22. Thereby, vibration having a frequency equivalent to the resonance frequency of the first restriction passage 22 is absorbed and attenuated.
Here, when the liquid flows into the first restriction passage 22 and enters the expansion portion 33, turbulence occurs due to the expansion of the cross-sectional area of the flow path. Further turbulence is generated due to the aforementioned inclination of the wall surface 33c.

In addition, when the secondary vibration is input from the vibration generating unit, the first attachment member 11 and the second attachment member 12 cause the two second pressure receiving members while elastically deforming the first elastic body 13 and the second elastic body 19. The liquid chambers 21 are relatively displaced in directions facing each other. At this time, the pair of second pressure receiving liquid chambers 21 expands and contracts separately, and the liquid flows through the second restriction passage 23 between the second pressure receiving liquid chamber 21 and the sub liquid chamber 17, and thus in the second restriction passage 23. Liquid column resonance occurs. Thereby, vibration having a frequency equivalent to the resonance frequency of the second restriction passage 23 is absorbed and attenuated.
The membrane 25 is deformed or displaced in the axial direction in the accommodating chamber 26 in response to the input of the high frequency vibration, and the first pressure receiving liquid chamber 16 and the auxiliary liquid chamber 17 are passed through the first and second communication holes 27 and 28. By allowing the liquid to flow between them, an increase in the dynamic spring constant of the first elastic body 13 is suppressed, and this vibration is absorbed and damped.

As described above, according to the vibration isolator 1 according to the present embodiment, not only the extension portion 33 having a wider groove width than the other portions is formed in the first restriction passage 22, but also Since the outer wall surface 33c of the expansion portion 33 is inclined so that the groove width gradually increases from one end portion to the other end portion in the cross-sectional view in the direction orthogonal to the groove width direction, In the process of flowing through the first restriction passage 22, not only at the beginning of entering the expansion part 33 but also in the process of flowing through the expansion part 33, turbulence is likely to occur due to the inclined outer wall surface 33 c. Thus, it is possible to easily disturb the flow of the liquid flowing through the expansion portion 33 in a complicated manner. Therefore, the flow resistance of the liquid in the first restriction passage 22 is reliably increased, and the frequency band that exhibits the damping action can be easily expanded.
Further, the first restriction passage 22 is formed in the bottom wall portion 18a of the partition member 18 and extends in the circumferential direction, and the expansion portion 33 of the first restriction passage 22 has a diameter larger than that of other portions. Since the size of the direction is large, it is possible to reliably obtain the vibration isolator 1 that can complicately disturb the flow of the liquid flowing through the expansion portion 33.

  The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

For example, in the said embodiment, although the compression-type structure was shown as the vibration isolator 1, the 2nd pressure receiving liquid chamber 21 is located in the vertical direction lower side, and the sub liquid chamber 17 is located in the vertical direction upper side. It may be a suspended structure that is used by being attached.
Moreover, the 1st, 2nd support parts 41 and 42 are not restricted to a concave shape, For example, you may exist in a flat surface.
Further, the peripheral lengths of the lower end portion of the one locking projection 35 and the other locking projection 36 may be equal to each other.
Moreover, you may employ | adopt the structure which does not have the 2nd elastic body 19 but the 2nd restriction | limiting channel | path 23 is not formed in the partition member 18. FIG.
Further, as the expansion portion 33, a configuration in which the size in the radial direction is the same and the size in the axial direction is larger than that of the other portions of the first restriction passage 22 may be adopted. . In this case, the groove width direction coincides with the axial direction, and the direction orthogonal to the groove width direction in the sectional view coincides with the radial direction.
Further, the first restriction passage 22 and the extension portion 33 may be formed in the peripheral wall portion of the partition member 18.

  In addition, it is possible to appropriately replace the constituent elements in the above-described embodiments with well-known constituent elements without departing from the spirit of the present invention, and the above-described modified examples may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 Vibration isolator 11 1st attachment member 12 2nd attachment member 13 1st elastic body (elastic body)
14 Diaphragm 15 Liquid chamber 16 First pressure receiving liquid chamber (pressure receiving liquid chamber)
17 Sub liquid chamber 18 Partition member 18a Bottom wall portion (substrate portion)
22 First restricted passage (restricted passage)
33 Extension part 33c, 33d Side wall surface

Claims (3)

A cylindrical first mounting member coupled to one of the vibration generating unit and the vibration receiving unit, and a second mounting member coupled to the other;
An elastic body that elastically connects these first and second mounting members;
A diaphragm that is disposed away from the elastic body on one side in the axial direction along the central axis of the first mounting member, and that defines a liquid chamber between the elastic body,
A partition member that divides the liquid chamber into a pressure receiving liquid chamber having the elastic body as a part of a wall surface and a sub liquid chamber having the diaphragm as a part of a wall surface;
A vibration isolator in which a restriction passage that connects the pressure receiving liquid chamber and the sub liquid chamber is formed in the partition member,
The restriction passage is formed with an extended portion having a wider groove width than other portions,
The groove width of the extension portion is in a direction orthogonal to the groove width direction in a cross-sectional view along a direction orthogonal to the flow direction of the liquid traveling between the pressure receiving liquid chamber and the sub liquid chamber in the restriction passage. Along gradually from one end to the other end along ,
The extension portion is disposed at a midway position between one end portion opening toward the pressure-receiving liquid chamber and the other end portion opening toward the sub liquid chamber in the restriction passage. An anti-vibration device characterized by that. The partition member includes a substrate portion whose front and back surfaces are directed in the axial direction,
The restriction passage extends in a circumferential direction around the central axis, and is formed on the front surface or the back surface of the substrate portion,
Of the restriction passage, the extension portion is formed to have a larger radial size perpendicular to the central axis in a plan view as viewed from the axial direction than the other portions, and the groove width direction is Match the radial direction,
Among the inner wall surfaces of the extension portion, at least one of the pair of side wall surfaces facing in the radial direction is inclined so as to gradually move away from the other as it goes from one end portion to the other end portion along the axial direction. The vibration isolator according to claim 1, wherein:   The vibration isolator according to claim 1 or 2, wherein the extension portion is disposed in a central portion between the one end portion and the other end portion of the restriction passage.

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