JP2008196508A - Fluid-sealed vibration isolating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid-sealed vibration isolating device of a novel structure, capable of suitably reducing costs and miniaturizing the device by advantageously arranging a short channel and a valve element while suppressing the number of parts, and besides stably providing both an aimed vibration isolating effect by flowing action of fluid through an orifice passage and an aimed abnormal noise and vibration suppressing effect when an impact load is input, by the stable opening and closing operation of the valve element. <P>SOLUTION: The guide shaft 56 of a partitioning member 34 is inserted into the guide hole 80 of a movable plate member 76, and also the short channel 90 for communicating a pressure receiving chamber 82 with a balancing chamber 84 is formed penetratingly through the guide shaft 56. Meanwhile, a tongue-like elastic valve element 62 is integrally formed with a cover plate member 38 attached to the partitioning member 34 by a cutoff portion 60. The elastic valve element 62 is put on the end surface of the guide shaft 56, thereby closing the opening of the short channel 90 on the side of the pressure receiving chamber 82. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid-filled vibration-proof type that obtains a vibration-proof effect based on a fluid action such as a resonance action of a fluid through an orifice passage that interconnects a pressure-receiving chamber filled with an incompressible fluid and an equilibrium chamber. In particular, the present invention relates to a fluid-filled vibration isolator having a mechanism for absorbing pressure fluctuations in a pressure receiving chamber.

  Conventionally, as a type of vibration isolator such as an anti-vibration coupling body and an anti-vibration support body interposed between members constituting the vibration transmission system, the anti-vibration mechanism is based on the flow action of an incompressible fluid enclosed therein. 2. Description of the Related Art A fluid-filled vibration isolator that obtains a vibration effect is known. In this fluid-filled vibration isolator, the first mounting member and the second mounting member are spaced apart from each other, and are elastically connected by the main rubber elastic body, and are incompressible inside the second mounting member. The structure is provided with a fluid sealing region in which a fluid is sealed. In such a fluid sealing region, a partition member fixedly supported by the second mounting member is disposed, and a pressure receiving chamber in which part of the wall portion is formed of a main rubber elastic body on both sides of the partition member. And an equilibrium chamber in which a part of the wall portion is formed of a flexible film is formed, and the pressure receiving chamber and the equilibrium chamber are communicated with each other by an orifice passage formed in the partition member. According to such a structure, a relative pressure fluctuation difference is generated between the pressure receiving chamber and the equilibrium chamber in accordance with the vibration input, and the amount of fluid flowing through the orifice passage is ensured. Since an anti-vibration effect can be obtained based on a fluid action such as an action, application to an engine mount, a body mount, a differential mount, for example, a suspension member mount, etc. for automobiles has been studied.

  However, the anti-vibration effect exerted by the resonance action of the fluid through the orifice passage is limited to a relatively narrow frequency range in which the orifice passage is tuned in advance. There was a problem that it was difficult.

  Therefore, for example, when vibrations that are problematic in the frequency range higher than the tuning frequency of the orifice passage are input, the purpose is to suppress the sudden rise in pressure fluctuation caused by the vibrations and to obtain a stable anti-vibration effect. It is proposed to provide a pressure fluctuation absorbing mechanism. As shown in Patent Document 1 (Japanese Patent Publication No. 07-107416), this pressure fluctuation absorbing mechanism is provided with a movable film on a partition member that partitions a pressure receiving chamber and an equilibrium chamber, and is provided on one surface. It has a structure in which the pressure of the pressure receiving chamber is exerted and the pressure of the equilibrium chamber is exerted on the other surface. With the vibration input in the high frequency range, the movable film is deformed and the pressure fluctuation is absorbed, so that a high dynamic spring is avoided.

  By the way, in the above-described fluid-filled vibration isolator, when a large vibration load is applied between the first mounting member and the second mounting member, abnormal noise may be generated from the vibration isolator. It was. Specifically, for example, when such a fluid-filled vibration isolator is used in an engine cloak for an automobile and travels on a wavy road, a speed breaker, etc., an abnormal noise or impact that can be experienced by a passenger in the passenger compartment Was sometimes emitted.

  The cause of such abnormal noise and vibration is the formation of bubbles that can be interpreted as cavitation. Such air bubbles are not compressed due to the fact that the fluid flow between the pressure receiving chamber and the equilibrium chamber through the orifice passage cannot follow when an impact load is input, and an excessive negative pressure is generated in the pressure receiving chamber. It is generated when the gas dissolved in the ionic fluid is separated from the fluid. Bubbles maintain a substantially spherical stable state in the process from generation to growth, but they deform upon collapse and form explosive micro jets, which become the water hammer pressure and become the first mounting member and second It is considered that the abnormal noise and vibration that cause problems as described above are generated by being transmitted to the mounting member and transmitted to the body of the automobile.

  Therefore, Patent Document 1 discloses a fluid-filled vibration isolator as one measure for dealing with the above-described problem. In such a fluid-filled vibration isolator, when a relative pressure difference between the pressure receiving chamber and the equilibrium chamber becomes excessive by making a cut in the movable film supported by the partition member, a movable based on the pressure difference is provided. The cut portion is opened by elastic deformation of the membrane, and the pressure receiving chamber and the equilibrium chamber are communicated with each other through the opening. As a result, it is considered that the overnegative pressure state of the pressure receiving chamber is eliminated and the occurrence of cavitation is suppressed.

  However, since the cut portion is provided in the movable film, even when an excessive positive pressure or the like that does not need to be opened is generated in the pressure receiving chamber, the movable film is greatly elastically deformed, and the cut portion is formed. There was a risk of opening. As a result, even when vibration is input in the tuning frequency range of the orifice passage to be vibrated, a short circuit occurs between the pressure receiving chamber and the equilibrium chamber, and the relative pressure fluctuation between the pressure receiving chamber and the equilibrium chamber is reduced. Due to inadequate flow of fluid through the orifice passage due to the fact that the difference is not effectively generated, the vibration isolation effect (high damping effect) based on the fluid action such as the resonance action of the fluid through the orifice passage is sufficient. There was a possibility that it was difficult to be demonstrated.

  In order to deal with such a problem, for example, a short-circuit channel that connects the pressure-receiving chamber and the equilibrium chamber to each other at a position different from the movable film of the partition member is provided, and a valve body is provided at the opening of the short-circuit channel. When a vibration of normal magnitude is input, the short-circuit flow path is closed by the valve body, so that the amount of fluid flow through the orifice passage is secured, while the valve body is displaced when shock vibration is input. Thus, it is conceivable to suppress the overnegative pressure state of the pressure receiving chamber by opening the short-circuit channel and short-circuiting the pressure-receiving chamber and the equilibrium chamber through the short-circuit channel.

  However, it has been difficult to secure a sufficient space for arranging the short-circuit channel and the valve body in the partition member including the movable film and the orifice passage employed in the fluid-filled vibration isolator having the conventional structure. Further, by separately preparing the valve body, the number of parts and the manufacturing process are increased, and there is a problem that it is difficult to advantageously reduce the manufacturing cost.

  Therefore, for example, as shown in Patent Document 2 (Japanese Patent Laid-Open No. 2003-148548) related to the prior application of the present applicant, a short-circuit channel is formed using a part of the orifice passage, A rubber valve is formed using a rubber elastic body integrally formed with the main rubber elastic body, and when a normal magnitude vibration is input, the short-circuit flow path is closed by the rubber valve provided at the opening of the short-circuit flow path. On the other hand, at the time of shocking vibration input, it is conceivable to elastically deform the rubber valve in accordance with the over-negative pressure state of the pressure receiving chamber and to short-circuit the pressure receiving chamber and the equilibrium chamber through the short-circuit channel.

  However, as a result of further studies by the present inventor, in the fluid-filled vibration isolator according to Patent Document 2, the short-circuit channel is formed using a part of the orifice channel, so that the orifice channel If the design freedom of the orifice passage is limited, or a part of the wall portion of the orifice passage is constituted by a rubber valve, the fluid flow action through the orifice passage may not be stably generated. It has been found. In addition, the valve body made of a rubber elastic body may be damaged due to repeated elastic deformation, thereby causing the possibility that the intended opening / closing operation of the short-circuit channel is difficult to stabilize. .

Japanese Patent Publication No. 07-107416 JP 2003-148548 A

  Here, the present invention has been made in the background as described above, the place to solve the problem, while the increase in the number of parts is suppressed, a short-circuit channel and a valve body are advantageously provided, In addition to being able to achieve low cost and compactness, the stable opening and closing operation of the valve body enables anti-vibration effects due to fluid flow through the target orifice passage and abnormal noise when shock loads are input. Another object of the present invention is to provide a fluid-filled vibration isolator having a novel structure that can stably obtain vibration reduction effects.

  Hereinafter, the aspect of this invention made in order to solve the above-mentioned subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

  That is, the feature of the present invention is that the first mounting member and the second mounting member are connected by the main rubber elastic body and sandwich the partition member fixedly supported by the second mounting member. A pressure receiving chamber in which a part of the wall is made of a rubber elastic body and an equilibrium chamber in which a part of the wall is made of a flexible film are formed on both sides, and an incompressible fluid is formed in the pressure receiving chamber and the equilibrium chamber. Is formed in the outer peripheral portion of the partition member, and the movable plate member can be displaced or deformed in the accommodation area provided in the partition member. The pressure fluctuation absorbing mechanism is configured so that the pressure of the pressure receiving chamber is exerted on one surface of the movable plate member and the pressure of the equilibrium chamber is exerted on the other surface of the movable plate member. In the fluid-filled vibration isolator, the partition member receives pressure An accommodation recess is provided that opens to the side, and the accommodation area is formed by covering the opening of the accommodation recess with a lid plate member, while the movable plate member accommodated in the accommodation area has a guide A hole is formed through the guide recess, and a guide shaft projects from the bottom of the housing recess. The guide shaft is inserted into the guide hole of the movable plate member, and the partition member passes through the guide shaft. A short-circuit flow path that connects the pressure-receiving chamber and the equilibrium chamber is formed, and a tongue-like elastic valve body is integrally formed by cutting the cover plate member, and the elastic valve body is formed at the tip surface of the guide shaft. And the fluid-filled vibration isolator in which the opening on the pressure receiving chamber side of the short-circuit channel is closed.

  In such a fluid filled type vibration isolator having a structure according to the present invention, an impact load is input between the first mounting member and the second mounting member, and an excessive negative pressure is applied to the pressure receiving chamber. When generated, the elastic valve body is elastically deformed so as to be separated from the distal end surface of the guide shaft, the short circuit channel is opened, and the pressure receiving chamber and the equilibrium chamber are communicated with each other through the short circuit channel. As a result, the excessive negative pressure state in the pressure receiving chamber is eliminated, and the generation of cavitation bubbles is suppressed, and abnormal noise that is a problem due to the generation of the bubbles is advantageously suppressed.

  Accordingly, since the elastic valve body is integrally formed with the cover plate member, an increase in the number of parts associated with the separate formation of the elastic valve body can be suppressed, and improvement in manufacturing efficiency and cost reduction can be advantageously achieved. . In addition, the forming material of the elastic valve body integrally formed with the cover plate member is for the purpose of ensuring the rigidity of the cover plate member constituting a part of the wall portion of the pressure receiving chamber and ensuring the spring characteristics of the elastic valve body. For example, spring steel or the like is preferably employed. As a result, the durability of the elastic valve body is improved and the opening / closing operation of the valve body is stabilized as compared with the case where the elastic valve body is formed of a rubber material or the like.

  Further, since the guide shaft provided in the partition member is inserted into the guide hole of the movable plate member, the movable plate member is stably positioned and arranged in the accommodation region, and the movable plate member is unexpectedly displaced or deformed. Therefore, the vibration isolation effect based on the displacement or deformation of the movable plate member can be stably obtained.

  In particular, in this structure, since the short-circuit channel is formed by using the guide shaft of the partition member, the arrangement space in the partition member of the short-circuit channel is advantageously secured, and the short-circuit channel is opened and closed. By forming the elastic valve body to be formed on the cover plate member, the space for disposing the elastic valve body of the partition member is omitted. That is, the degree of freedom in designing the orifice passage, the movable plate member, and the short-circuit passage in the partition member is increased.

  Therefore, in the fluid-filled vibration isolator of this structure, the cost is reduced and the size is advantageously reduced, but the valve body is stably opened and closed to prevent the fluid from flowing through the target orifice passage. The vibration effect and the effect of reducing abnormal noise and vibration at the time of impact load input can be advantageously exhibited.

  Further, in the fluid filled type vibration damping device according to the present invention, the movable plate member has a disk shape, a guide hole is provided on the central axis, and the guide shaft is inserted therethrough. Are preferably employed. According to this structure, since the guide hole is provided on the central axis of the movable plate member, local displacement or deformation of the movable plate member can be suppressed. As a result, it is possible to suppress the stress of the movable plate member from being excessive and to ensure the durability more advantageously. In addition, since the displacement or deformation of the movable plate member is stabilized, the movable plate member is partitioned. It is possible to suppress excessively or shockingly hitting the member or the cover plate member, and it is possible to advantageously reduce the occurrence of abnormal noise caused by such hitting.

  In the fluid filled type vibration damping device according to the present invention, the axial dimension of the outer peripheral portion of the guide hole in the movable plate member is larger than the axial dimension of the guide shaft formed in the housing recess, On the outer peripheral side of the shaft, the outer peripheral portion of the guide hole in the movable plate member is compressed in the axial direction between the bottom surface of the housing recess and the elastic valve body, so that the elastic valve body seals in a closed state of the short-circuit flow path A structure in which the mechanism is configured can be suitably adopted. According to such a structure, the closed state of the short-circuit channel is further ensured, and the pressure leakage through the short-circuit channel under the normal pressure of the pressure receiving chamber is advantageously suppressed, so that the fluid flow action through the orifice passage is suppressed. The anti-vibration effect based on this can be obtained more stably.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described. First, FIG. 1 shows an automobile engine mount 10 as an embodiment according to the fluid filled type vibration damping device of the present invention. The automobile engine mount 10 has a structure in which a first mounting bracket 12 as a first mounting member and a second mounting bracket 14 as a second mounting member are connected by a main rubber elastic body 16. The first mounting bracket 12 is mounted on the power unit side, and the second mounting bracket 14 is mounted on the vehicle body side, so that the power unit is supported in a vibration-proof manner with respect to the body.

  1 shows the state of the engine mount 10 as a single unit before being mounted on the automobile, but in the present embodiment, in the mounted state, the shared support load of the power unit is in the mount axis direction (in FIG. 1, (Up and down). Therefore, in the mounted state, the first mounting member 12 and the second mounting member 14 are displaced in the axial direction toward each other based on the elastic deformation of the main rubber elastic body 16. In addition, under such a mounted state, main vibrations to be vibrated are input substantially in the mount axis direction. In the following description, unless otherwise specified, the vertical direction refers to the vertical direction in FIG.

  More specifically, the first mounting member 12 has a small-diameter substantially cylindrical shape or a truncated cone shape, and a screw hole 18 that opens to the upper end surface is provided at the center portion thereof. The first mounting bracket 12 is screwed and fixed to a power unit side mounting member (not shown) through a screw hole 18.

  On the other hand, the second mounting bracket 14 has a large-diameter, generally cylindrical shape, and a stepped portion 20 that extends in a substantially annular plate shape is formed inward in the direction perpendicular to the axis at an axially intermediate portion thereof. In addition, a tapered portion 22 whose diameter dimension gradually decreases from the upper side to the lower side is formed at a portion from the inner peripheral edge of the stepped portion 20 to the upper side. The second mounting bracket 14 is fixed to a mounting member on the vehicle body side via a bracket (not shown).

  The first mounting bracket 12 is spaced apart from the opening of the second mounting bracket 14 having the tapered portion 22 so that the central axes of both the brackets 12 and 14 are positioned substantially on the same line. Yes. A main rubber elastic body 16 is disposed between the first mounting bracket 12 and the second mounting bracket 14.

  The main rubber elastic body 16 has a substantially frustoconical shape, and a mortar-shaped or hemispherical large-diameter recess 24 that opens downward is provided on an end surface on the large-diameter side. The small-diameter side end face of the main rubber elastic body 16 is vulcanized and bonded in a state where substantially the entire portion from the axially intermediate portion to the lower end portion of the first mounting member 12 is embedded. The inner peripheral surface of the tapered portion 22 of the second mounting bracket 14 is vulcanized and bonded to the outer peripheral surface of the large-diameter side end portion of the main rubber elastic body 16 over substantially the entire surface. Further, a thin seal rubber layer 26 integrally formed with the main rubber elastic body 16 is formed on the entire inner peripheral surface from the stepped portion 20 to the lower end portion of the second mounting bracket 14. In other words, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the first mounting bracket 12 and the second mounting bracket 14, whereby the first mounting bracket 12 and the second mounting bracket 12 are attached. The metal fittings 14 are elastically connected to each other by the main rubber elastic body 16, and the opening on one axial direction (the upper side in FIG. 1) of the second mounting metal fitting 14 is fluid-tight by the main rubber elastic body 16. Is blocked.

  A diaphragm 28 as a flexible film is provided in the opening of the second mounting member 14 in the other axial direction (the lower side in FIG. 1). The diaphragm 28 is made of a thin rubber film that can be easily deformed, and has a substantially disk shape that is slackened in the axial direction. A large-diameter cylindrical fixing ring 30 is vulcanized and bonded to the outer peripheral edge of the diaphragm 28, and the fixing ring 30 is fitted into the opening below the second mounting bracket 14, so that the second mounting Since the metal fitting 14 is subjected to diameter reduction processing such as an eight-way drawing, the fixing ring 30 is fitted and fixed in close contact with the second mounting metal fitting 14 via the seal rubber layer 26 compressed and deformed in the radial direction. ing.

  As a result, the diaphragm 28 is fixed to the second mounting bracket 14, and the opening in the other axial direction (the lower side in FIG. 1) of the second mounting bracket 14 is fluid-tightly covered with the diaphragm 28. Between the axially opposing surfaces of the main rubber elastic body 16 and the diaphragm 28 inside the second mounting bracket 14, a fluid sealing region 32 that is sealed with respect to the external space is formed.

  A partition member 34 is disposed in the fluid sealing region 32. 2 to 4, the partition member 34 has a circular block shape as a whole, and includes a partition member main body 36 and a cover plate metal member 38 as a cover plate member. .

  The partition member main body 36 has a circular block shape and is formed using a hard material such as a metal material or a synthetic resin material. In the central portion of the partition member main body 36, an accommodation recess 40 that opens upward from an axial intermediate portion thereof and a lower recess 42 that opens downward are formed. Each of these recesses 40 and 42 has a circular recess shape, and the diameter of the lower recess 42 is larger than the diameter of the housing recess 40. In addition, a through-hole 46 made up of a plurality of small holes is formed around the center of the thin disk-shaped bottom 44 constituting the bottom wall of the two recesses 40 and 42 in the intermediate portion of the partition member main body 36 in the axial direction. It is penetrating. Further, a circumferential groove 48 that spirally extends in the circumferential direction is formed on the outer peripheral portion of the partition member body 36, and both end portions of the circumferential groove 48 are formed at the upper end portion and the lower end portion of the partition member body 36, respectively. It is connected to each communication window 50 and 52 of the notch shape. In addition, a plurality of (three in the present embodiment) protrusions 54 project from the upper end portion of the partition member main body 36 around the accommodation recess 40 in the circumferential direction.

  Here, a guide shaft 56 is integrally formed in the partition member main body 36. The guide shaft 56 has a small-diameter columnar shape and projects from the central portion of the bottom 44 of the partition member main body 36 toward the housing recess 40. Since the protruding height of the guide shaft 56 is the same as the height of the peripheral wall portion of the housing recess 40, the circular protruding tip surface of the guide shaft 56 is the opening peripheral portion (surface) of the housing recess 40. It is positioned at the same height in the axial direction as the upper end surface of the partition member main body 36 to be formed.

  Further, a through hole 58 extending in the axial direction with a substantially constant circular cross section is formed on the central axis of the guide shaft 56, and both ends of the through hole 58 are connected to the protruding front end surface of the guide shaft 56 and the partition member main body 36. It penetrates the bottom surface of the bottom 44. That is, the through hole 58 is provided on the central axis of the partition member main body 36, and the aforementioned through hole 46 is formed around the through hole 58 that penetrates the bottom 44 of the partition member main body 36.

  On the other hand, as shown in FIG. 5, the lid plate metal 38 has a thin disk shape, and particularly has a relatively high spring constant such as spring steel and is a hard metal material. It is formed using. The lid plate metal 38 is provided with a peripheral hole 60 as a cutout. The peripheral hole 60 extends radially inward from a part of the outer peripheral portion of the lid plate metal 38 toward the central portion, extends around the center of the central portion in an arc shape, and further extends radially outward from the central portion. And has a long hole shape reaching another part of the outer peripheral portion.

  Thereby, a leaf spring valve 62 as an elastic valve body bordered by the peripheral hole 60 is integrally formed inside the peripheral hole 60 of the lid plate metal member 38. The radially outward portion of the leaf spring valve 62 is a rectangular plate-like rectangular portion 64 extending in the radial direction, and the radially central portion of the leaf spring valve 62 is a small-diameter disk shape. The rectangular portion 64 and the disc-shaped portion 66 cooperate to constitute a tongue-shaped elastic valve body. Further, the bent portion 68 is formed in the rectangular portion 64 of the leaf spring valve 62 so that the fold line extends in the width direction, so that the radially outer portion sandwiching the bent portion 68 of the rectangular portion 64. Is extending in parallel with the outer peripheral portion of the lid plate fitting 38, and is formed integrally with the radially inner portion and the distal end of the inner portion sandwiching the bent portion 68 of the rectangular portion 64. However, it inclines with respect to the outer peripheral part of the cover plate metal fitting 38 and protrudes outward from the cover plate metal piece 38 in the axial direction (downward in FIG. 5).

  Further, a through-hole 70 made up of a plurality of small holes is provided on the outer peripheral side of the peripheral hole 60 in the lid plate metal 38. Further, a cutout communication window 72 is formed on the outer peripheral edge of the lid plate metal 38. Further, a plurality of (three in this embodiment) insertion holes 74 are provided in the outer peripheral portion of the lid plate metal 38 so as to be spaced apart in the circumferential direction. Such a cover plate metal fitting 38 is advantageously realized by pressing a metal plate such as spring steel.

  Further, an elastic rubber plate 76 as a movable plate member is accommodated in the accommodation recess 40 of the partition member main body 36. As shown in FIG. 6, the elastic rubber plate 76 is made of a rubber elastic material and has a substantially disc shape as a whole. In particular, in the present embodiment, the outer diameter of the elastic rubber plate 76 is smaller than the diameter of the accommodation recess 40 of the partition member main body 36. In addition, the radial intermediate portion excluding the central portion and the outer peripheral portion of the elastic rubber plate 76 has a corrugated shape spreading so as to wave in the circumferential direction, and is not clearly shown in the drawing, but the surface of the radial intermediate portion A plurality of small protrusions are provided so as to project.

  In the central portion of the elastic rubber plate 76, a substantially cylindrical guide tube portion 78 having the largest axial dimension is formed as compared with other portions such as a radial intermediate portion and an outer peripheral portion of the elastic rubber plate 76. A guide hole 80 that penetrates the elastic rubber plate 76 in the thickness direction is formed by the inner hole of the guide cylinder portion 78. In short, the guide hole 80 is formed on the central axis of the disc-shaped elastic rubber plate 76.

  Particularly in the present embodiment, the diameter of the guide hole 80 is slightly larger than the diameter of the guide shaft 56 formed in the housing recess 40 of the partition member main body 36. Further, the axial dimension of the guide cylinder portion 78 in the outer peripheral portion of the guide hole 80 is larger than the axial dimension of the guide shaft 56 and the axial dimension of the peripheral wall portion of the housing recess 40. Further, the thickness dimension (axial dimension) of the elastic rubber plate 76 excluding the guide cylinder portion 78 is made smaller than the axial dimension of the guide shaft 56 and the axial dimension of the peripheral wall portion of the housing recess 40. ing.

  Such an elastic rubber plate 76 is fitted into the housing recess 40 of the partition member main body 36, and the guide shaft 56 of the partition member main body 36 is inserted into the guide hole 80 of the elastic rubber plate 76. Thus, the elastic rubber plate 76 is accommodated and disposed in the accommodating recess 40 so as to be positioned concentrically with the partition member main body 36, and the outer peripheral edge of the elastic rubber plate 76 is the peripheral wall of the accommodating recess 40. It is made to oppose over the perimeter at a predetermined distance in the direction perpendicular to the axis. In the state where the lower end portion of the guide cylinder portion 78 having the largest axial dimension in the elastic rubber plate 76 is overlapped with the bottom portion 44 around the guide shaft 56 of the housing recess 40, the radial intermediate portion of the elastic rubber plate 76 is arranged. And the outer peripheral portion are opposed to the bottom 44 of the receiving recess 40 at a predetermined distance in the axial direction, and do not protrude outward from the opening of the receiving recess 40 and enter the receiving recess 40. It is contained. Further, the upper end portion of the guide tube portion 78 is positioned above the protruding tip portion of the guide shaft 56 and slightly protrudes outward in the axial direction from the opening portion of the housing recess 40.

  A disc-shaped portion of the leaf spring valve 62 projecting outward in the axial direction from the lid plate metal 38 while the outer peripheral portion of the lid plate metal 38 is superposed on the upper end portion of the partition member main body 36 accommodating and arranging the elastic rubber plate 76. The partition member 34 is configured by overlapping 66 on the upper end portion of the guide cylinder portion 78 of the elastic rubber plate 76. Under such assembly, the plurality of protrusions 54 of the partition member main body 36 are inserted into the plurality of insertion holes 74 of the cover plate metal member 38, so that the circumferential positioning of the partition member main body 36 and the cover plate metal member 38 is determined. Then, the communication window 72 of the lid plate 38 is superimposed on the communication window 50 of the partition member main body 36.

  Prior to the assembly of the diaphragm 28 to the second mounting bracket 14, the partition member 34 is fitted in the axial direction from the opening below the second mounting bracket 14, so that the lid plate bracket of the partition member 34 is fitted. The outer peripheral portion of 38 is superposed on the stepped portion 20 of the second mounting member 14 via the seal rubber layer 26. A fixing ring 30 of a diaphragm 28 fitted in the second mounting bracket 14 is overlaid on the lower end portion of the partition member main body 36 of the partition member 34. Then, the outer diameter of the partition member main body 36 and the outer circumference of the cover plate metal 38 are obtained by reducing the diameter of the second mounting bracket 14 by reducing the diameter of the second mounting bracket 14 such as an eight-way drawing. The surface is superposed on the inner peripheral surface of the second mounting member 14 via a seal rubber layer 26 that is compressed and deformed in the direction perpendicular to the axis, and the tensile force in the axial direction accompanying the compression deformation in the direction perpendicular to the axis of the seal rubber layer 26 is superimposed. Due to the deformation, the outer peripheral portion of the partition member 34 is clamped and fixed between the stepped portion 20 of the second mounting bracket 14 and the fixing ring 30 of the diaphragm 28. Further, the seal rubber layer 26 attached to the step portion 20 is compressed and deformed in the axial direction, and is interposed between the outer peripheral portion of the cover plate metal 38 and the overlapping surface of the step portion 20, so that they are fluidized. It is closely stacked.

  Accordingly, the partition member 34 composed of the partition member main body 36 and the cover plate bracket 38 is fixedly supported by the second mounting bracket 14 so that the elastic rubber plate 76 is assembled to the inner side of the second mounting bracket 14. The fluid sealing region 32 is divided into two fluid tightly. On one side of the fluid sealing region 32 across the partition member 34, a part of the wall portion is constituted by the main rubber elastic body 16, and a pressure receiving pressure that causes pressure fluctuation based on elastic deformation of the main rubber elastic body 16. A chamber 82 is formed, and on the other side, an equilibrium chamber 84 in which a part of the wall portion is constituted by the diaphragm 28 is formed.

  The pressure receiving chamber 82 and the equilibrium chamber 84 are filled with an incompressible fluid. As the sealing fluid, for example, water, alkylene glycol, polyalkylene glycol, silicone oil or the like is adopted, and in order to effectively obtain a vibration isolation effect based on a fluid action such as a resonance action of the fluid, 0.1 Pa · It is desirable to employ a low-viscosity fluid of s or less. For example, the incompressible fluid is sealed in the pressure receiving chamber 82 or the equilibrium chamber 84, for example, the partition member 34 or the diaphragm for the integrally vulcanized molded product of the main rubber elastic body 16 including the first and second mounting brackets 12 and 14. It is preferably realized by performing the assembly of 28 in an incompressible fluid.

  Further, the circumferential groove 48 of the partition member main body 36 is fluid-tightly covered with the second mounting bracket 14, and one end of the circumferential groove 48 in the circumferential direction is aligned in the circumferential direction. The other end in the circumferential direction of the circumferential groove 48 is connected to the equilibrium chamber 84 through the communication window 52 of the partition member body 36 while being connected to the pressure receiving chamber 82 through the window 50 and the communication window 72 of the lid plate 38. Yes. As a result, an orifice passage 86 that spirally extends with a predetermined length in the circumferential direction on the outer peripheral side of the partition member main body 36 is formed, and the pressure receiving chamber 82 and the equilibrium chamber 84 are communicated with each other through the orifice passage 86. Thus, fluid flow through the orifice passage 86 is allowed between the chambers 82 and 84.

  In the present embodiment, the resonance frequency of the fluid that is caused to flow through the orifice passage 86 is effective against vibrations in a low frequency range around 10 Hz corresponding to engine shake or the like based on the resonance action of the fluid. It is tuned so that the damping effect is demonstrated. The orifice passage 86 is tuned by, for example, the rigidity of the wall springs of the pressure receiving chamber 82 and the equilibrium chamber 84, that is, the main rubber elastic body 16 corresponding to the amount of pressure change required to change the chambers 82 and 84 by a unit volume. It is possible to adjust the length and cross-sectional area of the orifice passage 86 while taking into consideration the characteristic values based on the respective elastic deformation amounts of the diaphragm 28 and the diaphragm 28. Generally, the pressure transmitted through the orifice passage 86 is The frequency at which the phase of the fluctuation changes to bring about the resonance state can be grasped as the tuning frequency of the orifice passage 86.

  Further, the lid plate metal 38 is overlapped in close contact with the upper end of the partition member main body 36, and the housing recess 40 of the partition member main body 36 is covered with the lid plate metal 38 in a fluid-tight manner, whereby the lid plate metal An accommodation area 88 is formed in a space defined by the accommodation recess 40 of the partition member body 36 and 38. In addition, the storage area 88 is formed by the cover plate metal member 38 being closely attached and fixed to the upper end portion of the partition member main body 36 before the partition member 34 is fixed to the second mounting member 14. Or the clamping force exerted between the stepped portion 20 of the second mounting bracket 14 and the axial direction of the fixing ring 30 of the diaphragm 28 when the partition member 34 is mounted on the second mounting bracket 14. The lid plate metal member 38 may be formed by closely overlapping the upper end portion of the partition member main body 36 using the action.

  Here, the elastic rubber plate 76 is accommodated and disposed in the accommodating region 88, and the disc of the leaf spring valve 62 is accompanied by the cover plate metal fitting 38 being closely adhered to the upper end portion of the partition member main body 36. The leaf spring valve 62 that is inclined with respect to the cover plate metal fitting 38 is overlapped with the upper end portion of the guide tube portion 78 of the elastic rubber plate 76 so that the leaf spring valve 62 is substantially parallel to the cover plate metal fitting 38. It can be elastically deformed. A downward elastic force based on the elastic deformation of the leaf spring valve 62 is exerted on the guide cylinder portion 78, and the lower end portion of the guide cylinder portion 78 is overlapped around the guide shaft 56 of the partition member main body 36 bottom 44. The guide cylinder 78 is compressed and deformed in the axial direction. As a result, the bottom 44 of the housing recess 40 of the partition member main body 36 and the leaf spring valve 62 of the lid plate metal 38 are sandwiched from both sides in the axial direction with respect to the guide cylinder portion 78 having the guide hole 80 of the elastic rubber plate 76. The central portion provided with the guide hole 80 of the elastic rubber plate 76 is constrained in a pressure-overlapping manner.

  In particular, in this embodiment, the wall portion on the pressure receiving chamber 82 side of the accommodation region 88 of the partition member 34 is configured to include the lid plate metal 38, and the elastic rubber is passed through the through hole 70 and the peripheral hole 60 of the lid plate 38. The pressure of the pressure receiving chamber 82 is applied to one surface (upper in FIG. 1) from the radially intermediate portion of the plate 76 to the outer peripheral edge portion, and the equilibrium chamber 84 of the accommodating region 88 of the partition member 34. The side wall portion is configured to include the bottom portion 44 of the partition member main body 36, and the other side from the radially intermediate portion to the outer peripheral edge portion of the elastic rubber plate 76 through the through hole 46 of the bottom portion 44 (in FIG. 1, The pressure in the equilibration chamber 84 is applied to the lower surface. Here, the through-hole provided in the lid plate metal member 38 includes the peripheral hole 60 that borders the leaf spring valve 62 in addition to the through-hole 70 formed of a plurality of small holes provided on the outer peripheral side of the peripheral hole 60. Has been.

  Therefore, the relative pressure difference between the pressure receiving chamber 82 and the equilibrium chamber 84 is exerted on the elastic rubber plate 76 in a state where the central portion of the elastic rubber plate 76 is constrained, and the elastic rubber plate 76 is removed from the radial intermediate portion. When the portion extending to the peripheral portion is elastically deformed, the pressure fluctuation in the pressure receiving chamber 82 is absorbed. That is, the pressure fluctuation absorbing mechanism according to the present embodiment includes the elastic rubber plate 76, the through hole 46 of the partition member main body 36, the through hole 70 of the lid plate metal member 38, and the peripheral hole 60. In particular, in this embodiment, when vibration is input in the middle frequency range of about 20 to 40 Hz corresponding to idling vibration, low-speed booming sound, etc., the vibration isolation effect is based on the pressure fluctuation absorbing effect of the pressure receiving chamber 82 due to elastic deformation of the elastic rubber plate 76. The natural frequency of the elastic rubber plate 76 is tuned so that (vibration insulation effect based on low dynamic spring characteristics) is effectively exhibited.

  In this case, a short-circuit channel 90 that allows the pressure receiving chamber 82 and the equilibrium chamber 84 to communicate with each other is formed by a through-hole 58 that penetrates the guide shaft 56 in the axial direction, and the partition member body of the lid plate metal 38 as described above. 36, a downward elastic force based on the elastic deformation of the leaf spring valve 62 is exerted on the guide tube portion 78, and the guide tube portion 78 is compressed and deformed in the axial direction, and the disc of the leaf spring valve 62 is compressed. Under the state where the shape portion 66 is superimposed on the guide tube portion 78, the opening of the short-circuit channel 90 toward the pressure receiving chamber 82 is covered fluid-tightly by the disc-like portion 66 of the leaf spring valve 62, and the short-circuit flow The path 90 is closed.

  On the other hand, in a state in which an excessive negative pressure is generated so that cavitation bubbles are generated in the pressure receiving chamber 82, a negative pressure action is exerted on the leaf spring valve 62, and the leaf spring valve 62 presses the guide cylinder portion 78. The guide cylinder portion 78 of the leaf spring valve 62 is pressed so as to be elastically deformed in a direction away from the state in contact with the guide cylinder portion 78 (that is, upward in FIG. 1) against its own elastic force. The magnitude of the elastic force is set. Such tuning of the elastic force is realized, for example, by setting and changing the shape and size of the leaf spring valve 62, the material, the inclination angle with respect to the lid plate fitting 38, and the like.

  When the automobile engine mount 10 having the above-described structure is mounted on the automobile and vibrations in a low frequency range such as an engine shake which is a problem during traveling are input, a relatively large pressure fluctuation occurs in the pressure receiving chamber 82. Be born. Since this pressure is large, the elastic rubber plate 76 tuned to a small amplitude cannot substantially absorb the pressure in the pressure receiving chamber 82. Moreover, the state in which the opening portion of the short-circuit channel 90 is closed by the leaf spring valve 62 is maintained. Therefore, the flow amount of the fluid through the orifice passage 86 is effectively ensured by the difference in the relative pressure fluctuation generated between the pressure receiving chamber 82 and the equilibrium chamber 84, and the fluid action such as the resonance action of the fluid is achieved. Based on this, an anti-vibration effect (high damping effect) effective against low-frequency vibrations such as engine shake is exhibited.

  In addition, when an idling vibration which is a problem when the vehicle is stopped or a vibration in a medium frequency range such as a low-speed booming sound which is a problem when traveling is performed, a pressure fluctuation with a small amplitude is caused in the pressure receiving chamber 82. At that time, since the frequency range of the vibration is higher than the tuning frequency of the orifice passage 86, the fluid passage resistance of the orifice passage 86 is remarkably increased due to the antiresonant action, and is substantially closed. In view of this, a significant high dynamic spring caused by substantial obstruction of the orifice passage 86 is absorbed by absorbing the pressure fluctuation of the pressure receiving chamber 82 based on the elastic deformation of the elastic rubber plate 76 tuned to the middle frequency range. Will be avoided. Therefore, a good anti-vibration effect (vibration insulation effect based on the low dynamic spring characteristics) against vibration in the middle frequency range is exhibited.

  Further, the automobile travels over a step, runs on a road surface with large irregularities, etc., and an impact load is input between the first mounting bracket 12 and the second mounting bracket 14, and the main rubber elastic body 16 suddenly moves. If excessively elastically deformed, an excessive negative pressure is induced in the pressure receiving chamber 82. When this negative pressure is exerted on the leaf spring valve 62, an elastic force that presses down the lower guide tube portion 78 by elastic deformation toward the upper side of the leaf spring valve 62 when the lid plate metal member 38 is assembled to the partition member main body 36. On the other hand, the elastic force is set to such an extent that the leaf spring valve 62 is released from being pressed and elastically deformed so as to be separated from the guide cylinder portion 78. Therefore, when the impact load is input, the leaf spring valve 62 is guided. When the opening operation is performed away from the cylindrical portion 78, the closed state of the short-circuit channel 90 is released, and the pressure receiving chamber 82 and the equilibrium chamber 84 are communicated with each other through the short-circuit channel 90. As a result, the over-negative pressure state of the pressure receiving chamber 82 is eliminated, and cavitation bubbles, which are the cause of abnormal noise, are advantageously suppressed.

  In the automotive engine mount 10 according to the present embodiment, the leaf spring valve 62 is formed by using the lid plate metal member 38 constituting the housing region 88 of the partition member main body 36. An increase in the number of parts associated with forming the partition member main body 36 and the lid plate metal 38 separately can be suppressed, and an improvement in manufacturing efficiency and cost reduction can be advantageously achieved.

  Further, since the elastic valve body is formed of a hard leaf spring valve 62 as compared with the rubber elastic body, the durability of the elastic valve body is improved and the opening / closing operation of the valve body is stabilized.

  Further, the guide hole 80 of the elastic rubber plate 76 is inserted into the guide shaft 56 projecting from the bottom 44 of the accommodation recess 40 of the partition member main body 36, and the elastic rubber plate 76 is accommodated in the accommodation area 88. In addition, the guide cylinder 78 formed in the central portion of the elastic rubber plate 76 is compressed and deformed between the leaf spring valve 62 and the bottom 44 of the partition member main body 36 in the axial direction, and the deformation of the central portion is constrained. Yes. As a result, the elastic rubber plate 76 is stably accommodated in the accommodating region 88, and the pressure variation in the pressure receiving chamber 82 is efficiently absorbed by the elastic deformation of the outer peripheral portion having a large effective area. The anti-vibration effect with respect to the vibration in the middle frequency range such as the idling vibration and the low-speed booming noise, which are the problems described above, can be obtained stably.

  In particular, in this structure, since the short-circuit channel 90 is formed using the guide shaft 56 of the partition member main body 36, the arrangement space in the partition member main body 36 of the short-circuit channel 90 is advantageously ensured. In addition, since the leaf spring valve 62 that opens and closes the short-circuit channel 90 is formed on the lid plate metal member 38, the space for disposing the leaf spring valve 62 in the partition member main body 36 is omitted. As a result, the design freedom of the orifice passage 86, the elastic rubber plate 76, and the short-circuit passage 90 in the partition member main body 36 is increased.

  Therefore, in the automobile engine mount 10 according to the present structure, the orifice passage 86, the elastic rubber plate 76, the short-circuit passage 90, and the like are tuned while the manufacturing process is advantageously shortened, the cost is reduced, and the size is reduced. The degree of freedom is improved, and the desired anti-vibration effect can be stably obtained.

  In the present embodiment, the elastic rubber plate 76 has a disk shape, and a guide hole 80 is provided on the central axis thereof, and the guide shaft 56 of the partition member main body 36 is inserted into the guide hole 80. Yes. As a result, local deformation of the elastic rubber plate 76 is suppressed, and a decrease in durability due to the large stress of the elastic rubber plate 76 is suppressed. In addition, the elastic deformation of the elastic rubber plate 76 is stabilized, The elastic rubber plate 76 can be prevented from excessively or shockingly hitting the bottom 44 of the partition member main body 36 and the lid plate metal member 38, and the generation of abnormal noise due to such hitting can be advantageously reduced.

  Furthermore, in this embodiment, the guide cylinder part 78 is formed in the outer peripheral part of the guide hole 80 in the elastic rubber plate 76, and the axial direction dimension of the guide cylinder part 78 is the guide shaft 56 formed in the accommodation recess 40. The guide cylinder portion 78 is compressed in the axial direction between the bottom 44 of the housing recess 40 and the leaf spring valve 62, so that the short-circuit channel 90 by the leaf spring valve 62 is formed. A sealing mechanism in the closed state is configured. As a result, the closed state of the short-circuit channel 90 is further ensured, and pressure leakage through the short-circuit channel 90 under normal pressure in the pressure receiving chamber 82 that does not need to open the short-circuit channel 90 is advantageously suppressed. Thus, the desired vibration isolation effect can be obtained more stably.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific descriptions in these embodiments, and various changes, modifications, and improvements based on the knowledge of those skilled in the art. Needless to say, any of these embodiments can be included in the scope of the present invention without departing from the spirit of the present invention.

  For example, the shape, size, structure, arrangement, number, and the like of the partition member 34, the leaf spring valve 62, the guide shaft 56, the elastic rubber plate 76, the guide hole 80, the short-circuit channel 90, and the like are limited to those illustrated. Not. In the following description, members and parts having substantially the same structure as those of the above-described embodiment are denoted by the same reference numerals as those of the above-described embodiment, and detailed description thereof is omitted.

  Specifically, for example, as shown in FIG. 7, the guide shaft 56 ′ of the partition member main body 36 and the guide hole 80 ′ of the elastic rubber plate 76 are both provided in the outer peripheral portion deviated from the mount center axis. The guide shaft 56 ′ may be inserted into the guide hole 80 ′ at the outer peripheral portion.

  Further, since the guide hole 80 ′ is deviated from the central axis, a thick elastic protrusion 92 is provided in the central portion of the elastic rubber plate 76 as shown in FIG. By compressing and deforming between the axial direction of the bottom 44 and the leaf spring valve 62, the deformation of the central portion is suppressed, or the elastic rubber plate 92 is not provided, and the central portion of the elastic rubber plate is placed between the bottom of the receiving recess and the plate. It is also possible to allow displacement or deformation of the central portion by accommodating a gap between the spring valves in the axial direction.

  In the above-described embodiment, the guide cylinder portion 78 protrudes around the guide hole 80 in the elastic rubber plate 76, and the axial dimension of the guide cylinder portion 78 is larger than the dimension of the guide shaft 56 of the partition member main body 36. The seal cylinder is configured by being enlarged and compressed and deformed between the bottom 44 of the housing recess 40 and the axial direction of the leaf spring valve 62. However, the guide cylinder 78 is not an essential component. Instead of the guide cylinder portion 78, it is also possible to configure a seal mechanism by providing a seal rubber on at least one of the opposing surfaces (superimposed surfaces) of the protruding tip surface of the guide shaft and the leaf spring valve.

  Furthermore, in the above-described embodiment, the elastic rubber plate 76 is sandwiched between the bottom surface of the housing recess 40 and the leaf spring valve 62 and elastically deformed at the center portion at least under the closed state of the short-circuit channel 90. It was in a restrained state by being stuffed. Under such a restrained state, the elastic rubber plate 76 is allowed to displace within the accommodation region 88 based on elastic deformation of the outer peripheral portion of the elastic rubber plate 76, and can exhibit a hydraulic pressure absorbing function when high-frequency vibration is input. However, it is not limited to this. Specifically, for example, the guide hole of the elastic rubber plate has an inner diameter larger than the outer diameter of the guide shaft, and the length in the axial direction is shortened, so that the entire elastic rubber plate is axially extended. It may be displaceable. With such a structure, the elastic rubber plate as a whole is displaced in the housing area based on the relative pressure fluctuation of the pressure receiving chamber and the equilibrium chamber, and the low dynamic spring is reduced in the high frequency area based on the pressure absorption of the pressure receiving chamber. Can be achieved. When the entire movable plate structure is employed in this way, for example, a seal rubber is provided on at least one of the opposing surfaces of the leaf spring valve and the guide shaft in order to improve fluid tightness when the short-circuit channel is closed. It is desirable to provide.

  Furthermore, in the above-described embodiment, the through holes provided in the cover plate metal member 38 that constitutes the wall portion of the partition member 34 on the pressure receiving chamber 82 side have the peripheral hole 60 that forms the leaf spring valve 62 and the periphery of the peripheral hole 60. However, according to the required vibration isolation characteristics, manufacturability, etc., it is also possible to configure with only the peripheral hole.

  In addition, in the above-described embodiments, specific examples of applying the present invention to an automobile engine mount have been described. However, the present invention is not limited to an automobile body mount, a differential mount, a suspension member mount, etc. Any of them can be applied to the body vibration isolator.

It is a longitudinal cross-sectional view of the engine mount for motor vehicles as one Embodiment of this invention, Comprising: The figure equivalent to the II cross section of FIG. The top view which shows the state which assembled | attached the elastic rubber board to the partition member which comprises some engine mounts for the said motor vehicles. The one side view of the partition member. The bottom view of the partition member. It is a longitudinal cross-sectional view of the cover board metal fitting which comprises a part of the partition member, Comprising: The figure corresponded to the VV cross section of FIG. The longitudinal cross-sectional view of the elastic rubber board. The longitudinal cross-sectional view of the principal part of the engine mount for motor vehicles as another specific example of this invention.

Explanation of symbols

10: Automotive engine mount, 12: First mounting bracket, 14: Second mounting bracket, 16: Rubber elastic body, 28: Diaphragm, 34: Partition member, 36: Partition body, 38: Cover plate bracket 40: receiving recess, 44: bottom, 56: guide shaft, 60: peripheral hole, 62: leaf spring valve, 76: elastic rubber plate, 80: guide hole, 82: pressure receiving chamber, 84: equilibrium chamber, 86: Orifice passage, 88: receiving area, 90: short circuit flow path

Claims (3)

The first mounting member and the second mounting member are connected by a main rubber elastic body, and part of the wall portion is sandwiched between the partition members fixedly supported by the second mounting member. A pressure receiving chamber made of a rubber elastic body and an equilibrium chamber in which a part of the wall portion is made of a flexible membrane are formed, and an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber. An orifice passage that allows the pressure receiving chamber and the equilibrium chamber to communicate with each other is formed in the outer peripheral portion of the partition member. On the other hand, a movable plate member is housed in a housing area provided in the partition member so as to be displaceable or deformable. The pressure fluctuation absorbing mechanism is configured such that the pressure of the pressure receiving chamber is exerted on one surface of the movable plate member and the pressure of the equilibrium chamber is exerted on the other surface of the movable plate member. In the enclosed vibration isolator,
The partition member is provided with a housing recess that opens to the pressure receiving chamber side, and the housing region is formed by covering the opening of the housing recess with a cover plate member. A guide hole is formed through the movable plate member accommodated in the housing, and a guide shaft projects from the bottom of the accommodation recess, and the guide shaft is formed in the guide hole of the movable plate member. The partition member is formed with a short-circuit flow path that penetrates the guide shaft and communicates the pressure receiving chamber and the equilibrium chamber. The elastic valve body is integrally formed, and the elastic valve body is overlaid on the tip end surface of the guide shaft so that the opening on the pressure receiving chamber side of the short-circuit channel is closed. Enclosed vibration isolator.   The fluid-filled vibration isolator according to claim 1, wherein the movable plate member has a disc shape, the guide hole is provided on a central axis of the movable plate member, and the guide shaft is inserted therethrough.   The axial dimension of the outer peripheral portion of the guide hole in the movable plate member is larger than the axial dimension of the guide shaft formed in the receiving recess, and the movable plate member is disposed on the outer peripheral side of the guide shaft. The outer peripheral portion of the guide hole in the cylinder is compressed in the axial direction between the bottom surface of the housing recess and the elastic valve body, thereby forming a seal mechanism under the closed state of the short-circuit channel by the elastic valve body The fluid-filled vibration isolator according to claim 1 or 2.

Images