JP5050283B2 - Liquid-filled vibration isolator - Google Patents

Description

  The present invention relates to a liquid-filled vibration isolator.

  As an anti-vibration device such as an engine mount that supports the vibration of a vibration source such as an automobile engine so as not to be transmitted to the vehicle body side, a first attachment attached to the vehicle body side, a second attachment attached to the vibration source side, An anti-vibration base made of a rubber-like elastic body interposed between these fixtures, a diaphragm made of a flexible rubber film, a main liquid chamber in which the anti-vibration base forms part of the chamber wall, and a diaphragm 2. Description of the Related Art There is known a liquid-filled vibration isolator including a secondary liquid chamber that forms a part of a wall and an orifice passage that communicates between the liquid chambers.

  In such a liquid filled type vibration isolator, during normal vibration input, the vibration damping function and the vibration insulation function are performed by the liquid column resonance action by the liquid flow in the orifice passage and the vibration damping effect of the vibration isolating substrate. When vibration is input, the vibration isolator itself may be an abnormal sound source and transmitted to the passenger compartment.

  This abnormal noise is generated by cavitation in the liquid chamber. Cavitation is due to clogging of the orifice passage when a large vibration is input to the vibration isolator, thereby causing the main liquid chamber to be in an excessively negative pressure state and below the saturated vapor pressure of the enclosed liquid. This is a phenomenon caused by the generation of a large number of bubbles. And the impact sound when the bubble generated in this way disappears becomes an abnormal sound and is transmitted to the outside.

  Therefore, in order to prevent the occurrence of abnormal noise due to this cavitation, for example, in Patent Document 1 below, an elastic film is provided in a partition part that partitions the main liquid chamber and the sub liquid chamber, and a cut is provided in the elastic film, Furthermore, this elastic membrane is sandwiched between constraining plates with different holes at the top and bottom, giving direction to the opening of the cut due to fluid pressure fluctuations in the main fluid chamber when large amplitude is input, and the main fluid chamber is in an excessively negative pressure state Is disclosed.

Further, in Patent Document 2 below, an elastic film is provided in a partition portion that partitions the main liquid chamber and the sub liquid chamber, and a cut is formed through the elastic film to constitute a common valve related to the tension and compression stages. However, it is disclosed that an extreme positive pressure state and an extreme negative pressure state are avoided by opening and closing the valve, thereby suppressing unpleasant noise and abnormal noise due to cavitation.
JP 2006-112607 A Japanese Patent Publication No. 7-107416 JP 2005-61482 A

  However, the structure disclosed in Patent Document 1 requires upper and lower restraint plates that sandwich the elastic film, and sound is generated when the elastic film comes into contact with these restraint plates when a large amplitude is input to the vibration isolator. There is a problem.

  Further, in the structure of Patent Document 2, liquid flow from the valve occurs not only on the tension side where cavitation causes a problem but also on the compression side, and the liquid flow in the orifice passage which is originally expected in the normal use region is reduced. As a result, the attenuation performance is degraded.

  In Patent Document 3, a main liquid chamber side adjustment protrusion that protrudes toward the main liquid chamber is provided at the center of the elastic film provided in the partition, and this protrusion is sandwiched by a central adjustment gap. The point which comprises making a pair of front-end | tip oppose is disclosed. However, in the same document, the protrusion is provided to restrict excessive deformation of the entire elastic membrane to the sub liquid chamber side in order to improve the nonlinear characteristic of the dynamic spring curve, and is used as a countermeasure for cavitation. Further, there is no disclosure of providing a cut through the elastic membrane so as to overlap the protrusion.

  The present invention has been made in view of the above points, and is a liquid-filled type capable of ensuring attenuation performance in a normal use region and alleviating cavitation caused by rapid pressure fluctuation at the time of large amplitude input. An object is to provide a vibration isolator.

The liquid-filled vibration isolator according to the present invention includes a first fixture that is attached to one of the vibration source side and the support side, a second fixture that is attached to the other of the vibration source side and the support side, and the first attachment. A vibration isolating base made of a rubber-like elastic body interposed between the fixture and the second fixture, and a flexibility for forming a liquid sealing chamber between the first fixture and the anti-vibration substrate. A diaphragm that partitions the liquid sealing chamber into a main liquid chamber on the side of the vibration isolating base and a sub liquid chamber on the diaphragm side, and an orifice passage that allows the main liquid chamber and the sub liquid chamber to communicate with each other. In the liquid-filled vibration isolator, the partition has an elastic film that divides the main liquid chamber and the sub liquid chamber, and the elastic film forms a part of the chamber wall of the main liquid chamber. a liquid chamber side film surface, wherein a sub liquid chamber side membrane surface which constitutes part of the chamber wall of the sub liquid chamber, the sub and the main liquid chamber side film surface Projection projecting into the main liquid chamber from the main liquid chamber side film surface of the chamber side membrane surface is provided, wherein an elastic film portion which the projections are provided auxiliary liquid chamber-side membrane surface is flat, elastic membrane The portion including the protrusion is provided with a notch penetrating the elastic film in the film thickness direction.

  In this way, by providing a protrusion on the main liquid chamber side film surface of the elastic membrane and providing a notch that penetrates the elastic film together with the protrusion, the direction of opening of the notch due to abrupt pressure fluctuations in the main liquid chamber is provided. You can have it. That is, when the liquid pressure in the main liquid chamber is reduced and is in a negative pressure state, the notch is opened by elastic deformation toward the main liquid chamber, thereby allowing the liquid to flow from the sub liquid chamber to the main liquid chamber. However, when the liquid pressure in the main liquid chamber rises and is in a positive pressure state, the projections are provided so that the notch is difficult to open, and the flow of liquid from the main liquid chamber to the sub liquid chamber is prevented or restricted. . Therefore, for example, when the main liquid chamber is in an excessively negative pressure state when a large amplitude is input to the vibration isolator, the negative flow in the main liquid chamber is caused by the flow of liquid from the sub liquid chamber to the main liquid chamber due to the opening of the cut. The pressure state is quickly eliminated, and the occurrence of cavitation is suppressed. On the other hand, since the flow of liquid from the main liquid chamber to the sub liquid chamber through the notch is blocked or restricted, the amount of liquid flowing in the orifice passage is not reduced in the normal use region, and high attenuation performance is ensured. can do. In addition, since the direction of opening of such a cut is realized without using a constraining plate, the problem of hitting sound can be solved.

  In the liquid-filled vibration isolator, the first fixture has a cylindrical shape, and the partition portion is provided inside the peripheral wall portion of the first fixture to form the orifice passage. And an elastic film having an outer peripheral portion held by an inner peripheral portion of the orifice forming member and closing between the inner peripheral portions of the orifice forming member, the elastic film being an inner periphery of the orifice forming member It may be fitted in a state compressed inward in the direction perpendicular to the axis with respect to the part. By holding the elastic film in a state compressed in the direction perpendicular to the axis in this way, the pressure difference required for opening the cut can be increased, and the cut can be hardly opened in the normal use region.

  In this case, the outer peripheral portion of the elastic membrane is provided with a first inclined surface portion that is inclined inward in the direction perpendicular to the axis toward the main liquid chamber side, and an inner portion of the orifice forming member into which the first inclined surface portion is fitted. A second inclined surface portion that is inclined inward in a direction perpendicular to the axis toward the main liquid chamber side is provided on the peripheral portion, and the elastic film is pressed into the orifice forming member from the sub liquid chamber side in the axial direction. It may be assembled. By providing such an inclined surface portion, the elastic film can be easily fitted in the compressed state. Further, by changing the angle of the inclined surface portion, the compression state of the elastic membrane can be arbitrarily controlled, and therefore the pressure difference required for opening the cut can be easily adjusted.

  In the liquid-filled vibration isolator, the orifice forming member extends inward in the direction perpendicular to the axis from the second inclined surface portion and presses and holds the outer peripheral portion of the main liquid chamber side film surface of the elastic membrane. A flange portion may be provided, and the inner peripheral edge portion of the inner peripheral flange portion may be shaped to rise to the vibration-proof substrate side via a curved portion. By providing the inner peripheral flange portion having such a shape, it is possible to prevent a hitting sound with the orifice forming member when the elastic film is elastically deformed toward the main liquid chamber.

  According to the present invention, it is possible to give directionality to the opening of the notch due to abrupt pressure fluctuations in the main liquid chamber, to reduce the occurrence of cavitation due to the pressure drop of the main liquid chamber during large amplitude input, and to normal use It is possible to achieve both high attenuation performance in the region.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of a liquid filled type vibration damping device 10 according to an embodiment. The vibration isolator 10 is an engine mount that supports an automobile engine, and includes a lower first mounting member 12 that forms a cylindrical shape that is attached to a support-side vehicle body, and an upper side that is attached to an engine side that is a vibration source. The second fixture 14, a vibration isolating base 16 made of a rubber elastic body interposed between the two fixtures 12, 14 and connecting the both, and the first fixture 12 facing the vibration isolating base 16. And a diaphragm 20 made of a flexible rubber film that forms a liquid sealing chamber 18 between the anti-vibration base 16 and the diaphragm 20.

  The first fixture 12 is a main body metal fitting that includes a cylindrical body portion 22 that forms the liquid sealing chamber 18 on the inner side thereof, and a bottomed cylindrical portion 24 that is caulked and fastened to a lower end portion 22A thereof. The second fixture 14 is a boss fitting disposed above the shaft core portion of the first fixture 12. The anti-vibration base 16 is formed in a substantially umbrella shape, and is vulcanized and bonded in a state where the second fixture 14 is embedded in the upper portion thereof, and the lower end outer peripheral portion is vulcanized and bonded to the upper end opening 22B of the cylindrical body portion 22. Has been. A rubber layer 26 covering the inner peripheral surface of the cylindrical body portion 22 is connected to the lower end portion of the vibration isolation base 16. The diaphragm 20 has an annular reinforcing metal fitting 20 </ b> A embedded and integrated in an outer peripheral portion thereof, and the reinforcing metal fitting 20 </ b> A is fixed to a caulking fastening portion between the cylindrical body portion 22 and the bottomed cylindrical portion 24.

  The liquid enclosure 18 is formed between the lower surface of the vibration isolation base 16 and the diaphragm 20 on the inner side of the cylindrical body 22, and the vibration isolation base 16 side, that is, the vibration isolation base 16 is formed by the partition portion 28. The upper main liquid chamber 18A forming a part of the chamber wall and the diaphragm 20 side, that is, the lower sub liquid chamber 18B forming a part of the chamber wall are partitioned. The main liquid chamber 18 </ b> A and the sub liquid chamber 18 </ b> B are communicated with each other by a single orifice passage 30.

  The partition portion 28 has an annular orifice forming member 32 fitted inside the peripheral wall portion 22C of the cylindrical body portion 22 via a rubber layer 26, and the main liquid chamber 18A and the sub liquid chamber 18B are axially disposed inside the partition portion 28. The elastic film 34 is composed of a rubber-like elastic body partitioned into X, and a ring-plate-shaped partition receiving plate 36 that receives the lower end of the orifice forming member 32.

  The orifice forming member 32 has a U-shaped cross-section that opens outward, and is fitted to the inner peripheral surface of the cylindrical body portion 22 via the rubber layer 26 so that the orifice forming member 32 is spaced from the inner peripheral surface. The orifice passage 30 extending along the circumferential direction is formed. The orifice forming member 32 fixes the partition receiving plate 36 to the lower end portion of the vibration-isolating base 16 and the partition receiving plate 36 by fixing the partition receiving plate 36 together with the reinforcing metal fitting 20A to the caulking fastening portion between the cylindrical body portion 22 and the bottomed cylindrical portion 24. The plate 36 is held between the plates 36 in the axial direction X. The orifice forming member 32 includes a flange-shaped inner peripheral portion 32A that protrudes inwardly in the axially perpendicular direction Y1.

  The elastic membrane 34 is a rubber member whose outer peripheral portion 34A is held by vulcanization adhesion to the inner peripheral portion 32A of the orifice forming member 32, and closes between the inner peripheral portions 32A, and has a disk shape. On the elastic film 34, a protrusion 38 is projected from the elastic film body having a substantially constant thickness toward the main liquid chamber 18A. That is, the protrusion 38 is provided so as to protrude from the main liquid chamber side film surface 34M into the main liquid chamber 18A among the main liquid chamber side film surface 34M and the sub liquid chamber side film surface 34N of the elastic film 34. It is not provided on the chamber side film surface 34N. In this example, as shown in FIGS. 2 and 3, the protrusion 38 has a truncated cone shape and is provided at the center of the elastic film 34.

  As shown in FIGS. 1 to 3, the elastic film 34 includes the protrusion 38 and the elastic film 34 including the protrusion 38 in the film thickness direction T (the same direction as the axial direction X). A notch 40 is provided to penetrate through. The incision 40 is a slit that penetrates the elastic film 34 in the film thickness direction T and allows the main liquid chamber 18A and the sub liquid chamber 18B to communicate with each other, that is, a cutting line, and is closed at the neutral position shown in FIG. Opened by elastic deformation to X.

  Specifically, the protrusion 38 is provided only on the main liquid chamber 18A side in the portion where the cut 40 is provided, so that the opening of the cut 40 is given directionality. That is, when the main liquid chamber 18A is in a negative pressure state with a low pressure relative to the sub liquid chamber 18B, the elastic film portion in the vicinity of the notch 40 can be opened by being elastically deformed so as to be pulled toward the main liquid chamber 18A. Yes, the liquid flow from the sub liquid chamber 18B to the main liquid chamber 18A is allowed. On the other hand, when the main liquid chamber 18A is in a positive pressure state with a high pressure relative to the sub liquid chamber 18B, the projection 38 prevents the opening of the notch 40, and the flow of liquid from the main liquid chamber 18A to the sub liquid chamber 18B is prevented. Blocked or restricted.

  As shown in FIG. 3, the cuts 40 are provided radially from the center O of the protrusion 38 in a plan view, and the plurality of cuts 40 are formed at equal angles from the center O to the outside. Here, six cuts 40 are provided at an angle of 60 °, but four cuts may be provided in a cross shape, or three cuts may be provided in a Y shape, There is no particular limitation.

  Further, the outer end 40A of the notch 40 extends to the elastic film portion 34C outside the elastic film portion 34B where the protrusion 38 is provided. In other words, the projection 38 is formed smaller than the range where the cut 40 is provided, thereby reducing the volume of the projection 38 and reducing the resistance when the cut 40 opens to the main liquid chamber 18A side. Yes. The notch 40 does not cut the elastic film 34 in its entire radial direction, and an uncut elastic film portion is secured outside the notch 40. The notch 40 can be provided so as to be accommodated in the elastic film portion 34B provided with the protrusion 38.

  In the liquid-filled vibration isolator 10 of the present embodiment configured as described above, the displacement on the compression side in which the second fixture 14 is directed downward is input in the normal use region, for example, in the case of shake vibration with an amplitude of about 0.5 mm. When the main liquid chamber 18A is in a positive pressure state, the protrusions 38 are provided on the elastic film 34 so that the cuts 40 are not easily opened, and the flow of liquid from the main liquid chamber 18A to the sub liquid chamber 18B is prevented. Is done. Therefore, the amount of liquid flowing through the orifice passage 30 is not reduced, and high attenuation performance can be ensured.

  On the other hand, when a large amplitude exceeding 1 mm amplitude is input, for example, when a vibration having an amplitude of about 2 mm is input, a displacement on the pulling side toward which the second fixture 14 moves upward is input, and the main liquid chamber 18A is in an excessively negative pressure state. Then, the elastic film 34, particularly the elastic film portion in the vicinity of the cut 40, is elastically deformed so as to swell upward, and the cut 40 is opened, so that the liquid flows from the sub liquid chamber 18B to the main liquid chamber 18A. . Thereby, the negative pressure state in the main liquid chamber 18A is quickly eliminated, and the occurrence of cavitation is suppressed.

  Further, since the protrusion 38 is provided in the central portion of the elastic film 34 and the cut 40 is provided in the elastic film portion of the central portion, the cut 40 is easy to open. Further, since the cuts 40 are provided radially from the center of the protrusion 38, the cuts 40 can be easily opened.

  FIG. 4 shows a liquid-filled vibration isolator 100 according to another embodiment. In this example, the configuration of the partition portion 28 is different from that of the above embodiment. That is, the partition portion 28 includes an orifice forming member 132, an elastic membrane 134, and a partition receiving plate 136. The basic configuration of each member is the orifice forming member 32, the elastic membrane 34, and the partition receiving member in the previous embodiment. Although they are common to the plates 36, they are different from those of the previous embodiment in the following points. Only the differences will be described below.

  In this example, the elastic membrane 134 has a thick outer peripheral portion 134A, and the outer peripheral portion 134A is held in a fitted state rather than vulcanized adhesion to the inner peripheral portion 132A of the orifice forming member 132. Yes. Specifically, the outer peripheral portion 134 </ b> A of the elastic film 134 is sandwiched in the axial direction X between the inner peripheral portion 132 </ b> A of the orifice forming member 132 and the inner peripheral portion 136 </ b> A of the partition receiving plate 136.

  Further, the outer diameter of the elastic film 134 is set larger than the diameter of the inner peripheral part 132A of the orifice forming member 132 with which the elastic film 134 is fitted, and thereby the elastic film 134 has the inner peripheral part 132A of the orifice forming member 132. On the other hand, it is fitted in a compressed state, that is, in a reduced diameter state, in the direction Y1 perpendicular to the axis.

  Specifically, as shown in FIGS. 5 and 6, the outer peripheral portion 134 </ b> A of the elastic film 134 is provided with a first inclined surface portion 138 that is inclined upward, i.e., inwardly in the direction Y perpendicular to the axis toward the main liquid chamber 18 </ b> A. ing. That is, the outer peripheral surface of the elastic film 134 constitutes a first inclined surface portion 138 having a tapered surface shape with a gradually decreasing diameter toward the main liquid chamber 18A side. Similarly to the first inclined surface portion 138, the inner peripheral portion 132A of the orifice forming member 132 to which the first inclined surface portion 138 is fitted is inclined in the axially perpendicular direction Y1 toward the main liquid chamber 18A side. A second inclined surface portion 140 is provided. The elastic film 134 is assembled by being pressed into the orifice forming member 132 in the axial direction X from below, that is, from the sub liquid chamber 18B side. Since it is narrowed to the inner side Y1 in the direction perpendicular to the axis, the elastic film 134 can be easily fitted in a reduced diameter state.

  When the elastic film 134 is held in a reduced diameter state in this way, the cut surfaces of the cut 40 are pressed against each other, so that the pressure difference between the main liquid chamber 18A and the sub liquid chamber 18B required to open the cut 40 increases. . Accordingly, in the present embodiment, the cut 40 is set so as not to open in any direction in the normal use region, and the high attenuation performance in the normal use region can be further ensured. Moreover, since the diameter-reduced state of the elastic film 134 can be arbitrarily controlled by changing the angles of the inclined surface portions 138 and 140, the pressure difference required for opening the cut 40 can be easily adjusted. It becomes possible. More specifically, in this example, the inclination angle θ1 with respect to the axial direction X of the first inclined surface portion 138 of the elastic film 134 is set smaller than the inclination angle θ2 with respect to the axial direction X of the second inclined surface portion 140 of the orifice forming member 132. Thus, the elastic film 134 can be more effectively reduced in diameter.

  Further, in this embodiment, the orifice forming member 132 has the above-described second inclined surface portion 140, and thus has a cross-sectional sideways V-shape opened outward. And the inner peripheral flange part 142 is extended over the perimeter from the upper end of this 2nd inclined surface part 140 to the axially orthogonal direction inside Y1. The inner peripheral flange portion 142 presses the outer peripheral portion 134A of the main liquid chamber side membrane surface 134M of the elastic membrane 134 to hold the elastic membrane 134 with the inner peripheral portion 136A of the partition receiving plate 136. It is. The inner peripheral edge portion 142A of the inner peripheral flange portion 142 has a shape that rises upward, that is, toward the antivibration base 16 via the curved portion 142B. Thus, by raising the inner peripheral flange portion 142 in a curved shape, it is possible to prevent a hitting sound with the orifice forming member 132 when the elastic film 134 is elastically deformed toward the main liquid chamber 18A.

  In this embodiment, an annular recess 144 is provided in the main liquid chamber side film surface 134M around the protrusion 38 of the elastic film 134, so that when the large amplitude is input, the main liquid chamber 18A has an excessive negative pressure. When the state is reached, the elastic film portion around the cut 40 of the elastic film 134 is easily deformed, and the cut 40 can be opened quickly.

  Other configurations are the same as those of the embodiment of FIG. 1 including the configurations of the protrusions 38 and the notches 40, and the same effects as those described above in the present embodiment are exhibited.

  In the above-described embodiment, the single-orifice structure vibration isolator having a single orifice passage has been described. However, if the liquid-filled vibration isolator is configured to communicate between a plurality of liquid chambers through the orifice passage, a double orifice is used. The present invention can be applied to various liquid-filled vibration isolators such as a structure vibration isolator.

  Further, the liquid-filled vibration isolators 10 and 100 may be vertically inverted and assembled to the vehicle. Furthermore, in addition to the engine mount, various vibration isolators such as a body mount and a diff mount can be used. It is applicable to. Although not enumerated one by one, various modifications can be made without departing from the spirit of the present invention.

1 is a longitudinal sectional view of a liquid-filled vibration isolator according to one embodiment. The perspective view which cuts and shows the partition part of the vibration isolator Plan view of the elastic membrane of the partition Longitudinal sectional view of a liquid filled type vibration isolator according to another embodiment Sectional drawing of the partition part which concerns on this other embodiment Exploded sectional view of the partition part according to the other embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,100 ... Liquid enclosure type vibration isolator 12 ... 1st fixture 14 ... 2nd fixture 16 ... Anti-vibration base | substrate 18 ... Liquid enclosure chamber, 18A ... Main liquid chamber, 18B ... Secondary liquid chamber 20 ... Diaphragm 28 ... Partition Part 30: Orifice passage 32, 132 ... Orifice forming member, 32A, 132A ... Inner peripheral part 34, 134 ... Elastic membrane, 34A, 134A ... Outer peripheral part, 34B ... Elastic membrane part provided with projection, 34C ... Than projection Outer elastic membrane part, 34M, 134M ... main liquid chamber side membrane surface, 34N ... subfluid chamber side membrane surface 38 ... projection 40 ... cut 40A ... outer end 138 ... first inclined surface portion 140 ... second inclined surface portion 142 ... Inner peripheral flange portion 142A ... inner peripheral edge portion 142B ... curved portion O ... center of projection T ... film thickness direction X ... axial direction Y1 ... axis perpendicular direction inward θ1 ... inclination angle θ2 of first inclined surface portion ... second inclination Inclination angle of face

Claims (5)

A first fixture attached to one of the vibration source side and the support side;
A second fixture attached to the other of the vibration source side and the support side;
An anti-vibration base made of a rubber-like elastic body interposed between the first fixture and the second fixture;
A flexible diaphragm that is attached to the first fixture and forms a liquid-enclosed chamber with the anti-vibration base;
A partition for partitioning the liquid sealing chamber into a main liquid chamber on the vibration-proof base side and a sub liquid chamber on the diaphragm side;
An orifice passage communicating the main liquid chamber and the sub liquid chamber;
With
The partition has an elastic film that partitions the main liquid chamber and the sub liquid chamber, and the elastic film includes a main liquid chamber side film surface forming a part of a chamber wall of the main liquid chamber, and the sub liquid. A secondary liquid chamber side film surface constituting a part of the chamber wall of the chamber, and protrudes from the main liquid chamber side film surface of the main liquid chamber side film surface and the auxiliary liquid chamber side film surface into the main liquid chamber. Protrusions are provided, and the sub-liquid chamber side film surface is flat at the elastic film portion provided with the protrusions, and a cut is provided in the elastic film portion including the protrusions and penetrating the elastic film in the film thickness direction. Was
Liquid-filled vibration isolator.   The first fixture has a cylindrical shape, and the partition portion is provided inside the peripheral wall portion of the first fixture to form the orifice passage, and an inner circumference of the orifice formation member And an elastic film that holds an outer peripheral part and closes an inner peripheral part of the orifice-forming member, and the elastic film is inwardly perpendicular to the inner peripheral part of the orifice-forming member. The liquid-filled vibration isolator according to claim 1, which is fitted in a compressed state.   A first inclined surface portion inclined in an axially perpendicular direction toward the main liquid chamber side is provided on an outer peripheral portion of the elastic membrane, and an inner peripheral portion of the orifice forming member to which the first inclined surface portion is fitted. A second inclined surface portion inclined inward in a direction perpendicular to the axis toward the main liquid chamber side is provided, and the elastic film is assembled by being press-fitted in the axial direction from the sub liquid chamber side to the orifice forming member. The liquid-filled vibration isolator according to claim 2.   The liquid-filled vibration isolator according to claim 3, wherein an inclination angle of the first inclined surface portion with respect to the axial direction is set to be smaller than an inclination angle of the second inclined surface portion with respect to the axial direction.   The orifice forming member has an inner peripheral flange portion that extends inward in a direction perpendicular to the axis from the second inclined surface portion and presses and holds the outer peripheral portion of the main liquid chamber side membrane surface of the elastic membrane, The liquid-filled vibration isolator according to claim 3, wherein an inner peripheral edge portion of the flange portion is raised to the vibration isolating substrate side through a curved portion.

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