JP4088836B2 - Fluid filled vibration isolator - Google Patents

Description

  The present invention relates to a fluid-filled vibration isolator that obtains a vibration-proof effect based on the flow action of an incompressible fluid enclosed therein, and is suitably employed, for example, as an engine mount for an automobile. The present invention relates to a fluid-filled vibration isolator.

  Conventionally, an anti-vibration device in which a first attachment member and a second attachment member are connected by a main rubber elastic body as an anti-vibration coupling body or an anti-vibration support body interposed between members constituting a vibration transmission system. Is widely adopted in various fields. As one type, the first mounting member and the second mounting member are connected by the main rubber elastic body, while the main rubber elastic body forms a part of the wall portion, and the first mounting member and the second mounting member. A pressure receiving chamber in which pressure fluctuations are generated when vibration is input between them, and a balance chamber in which a part of the wall is formed by a flexible membrane and volume change is generated based on deformation of the flexible membrane. In addition, a fluid-filled vibration isolator has been proposed in which an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber, and an orifice passage that communicates the pressure receiving chamber and the equilibrium chamber is provided (for example, a patent). Reference 1).

  In such a fluid-filled vibration isolator, the vibration-proof effect can be obtained by utilizing the fluid action such as the resonance action of the enclosed incompressible fluid, and only by the vibration-proof action of the main rubber elastic body. Low dynamic spring effect and high damping effect that can not be obtained can be easily obtained in the tuning frequency range of the orifice passage. For example, an automobile engine that requires high vibration isolation performance in a specific frequency range Application to mounts and body mounts is under consideration.

  However, when the present inventors have examined such a fluid-filled vibration isolator, a large vibration load is applied between the first mounting member and the second mounting member during cranking or the like. As a result, it was confirmed that abnormal vibration and vibration may be emitted from the vibration isolator.

  When the present inventor conducted many experiments on the occurrence of abnormal noise and vibration in such a fluid-filled vibration isolator, the impact between the first mounting member and the second mounting member is large. It was confirmed that when a vibration load was input, a large negative pressure was generated in the pressure receiving chamber, so that air dissolved in the sealed fluid was separated and bubbles were generated. Then, the explosive micro jet (micro jet) generated when the bubbles collapse in the pressure receiving chamber propagates to the first mounting member and the second mounting member as a water hammer pressure, thereby Acquired knowledge that abnormal noise and vibration, which are problematic in this type of fluid-filled vibration isolator, have been the cause of such abnormal noise and vibration. .

  In addition, as a result of further studies by the inventor, bubbles that cause abnormal noise and vibration in question grow larger as the shocking negative pressure induced in the pressure receiving chamber increases. As a result, it was confirmed that the abnormal noise and vibration generated tend to increase.

JP 2000-274480 A

  The present invention has been made in the background as described above, and the problem to be solved is to effectively secure the vibration-proofing effect exhibited based on the flow action of the enclosed incompressible fluid. On the other hand, it is an object of the present invention to provide a fluid-filled vibration isolator having a novel structure capable of reducing or preventing the generation of abnormal noise and shock when a large vibration or load is applied.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. In addition, 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 can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized on the basis of.

(Aspect 1 of the present invention)
A feature of the first aspect of the present invention is that the first mounting member and the second mounting member that are spaced apart from each other are connected by the main rubber elastic body, while a part of the wall portion is connected by the main rubber elastic body. The pressure receiving chamber configured and a flexible membrane form an equilibrium chamber in which a part of the wall portion is formed, and an incompressible fluid is sealed in each of the pressure receiving chamber and the equilibrium chamber, and the pressure receiving chamber is balanced. In the fluid-filled vibration isolator in which the chambers are communicated with each other through an orifice passage, a part of the wall portion different from the main rubber elastic body in the pressure receiving chamber is constituted by a thin pressure receiving rubber plate, and the pressure receiving rubber A rigid wall surface extending along the pressure-receiving rubber plate is formed on the opposite side of the pressure-receiving chamber across the plate, and is sealed from an external space between the opposing surfaces of the pressure-receiving rubber plate and the rigid wall surface. A small space is formed, and the internal pressure of the pressure receiving chamber reaches 0.6 MPa. The elastic deformation of the pressure-receiving rubber plate from the pressure-receiving chamber to the outside is prevented by substantial contact with the rigid wall surface, while the pressure-receiving rubber plate is inwardly directed toward the pressure-receiving chamber. In the fluid-filled vibration isolator, elastic deformation is allowed based on the volume expansion of the minute space.

  In the fluid-filled vibration isolator having the structure according to this embodiment, a small amount of air is sealed in a minute space formed between the pressure-receiving rubber plate and the opposing surface of the rigid wall surface. Therefore, when an abrupt negative pressure is generated in the pressure receiving chamber, the pressure receiving rubber plate quickly follows and deforms by utilizing the expansion of air in the minute space, and shock pressure fluctuation can be reduced. As a result, gas phase separation in the incompressible fluid in the pressure receiving chamber is suppressed, and generation of large bubbles is avoided, and the amount of energy generated when the bubbles disappear is reduced. Abnormal noise and vibration can be suppressed.

  In particular, the amount of air enclosed in the minute space is very small, and immediately after the pressure increase of 0.6 MPa, the pressure-receiving rubber plate is substantially in contact with and restrained against the rigid wall surface to prevent its bulging deformation. As a result, the pressure fluctuation particularly toward the positive pressure side of the pressure receiving chamber is effectively generated. Therefore, when a vibration to be damped is input, the pressure fluctuation in the pressure receiving chamber is not excessively absorbed by the deformation of the pressure receiving rubber plate, and an effective pressure fluctuation occurs between the pressure receiving chamber and the equilibrium chamber. As a result, the amount of fluid flow through the orifice passage is efficiently ensured, and the vibration isolation effect based on the fluid action such as the resonance action of the fluid can be effectively exhibited.

  In this aspect, the pressure-receiving rubber plate, the rigid wall surface, and the shape, size, and structure of the minute space are not limited in any way. For example, a recess that opens the rigid wall surface toward the inside of the pressure-receiving chamber. The pressure-receiving rubber plate is formed into a bag shape that opens in a concave shape toward the inside of the pressure receiving chamber along the shape of the rigid wall surface, or the rigid wall surface faces the inside of the pressure receiving chamber. For example, it is preferable that the pressure receiving rubber plate has a bag shape protruding toward the inside of the pressure receiving chamber along the shape of the rigid wall surface. This makes it possible to efficiently secure the surface area of the pressure-receiving rubber plate even when the pressure-receiving rubber plate or the rigid wall surface is small, and to reduce pressure fluctuations based on the elastic deformation of the pressure-receiving rubber plate. Can be done effectively. Further, in this aspect, a substantially constant gap is formed between the opposing surfaces of the rigid wall surface and the pressure-receiving rubber plate, that is, between the opposing surfaces of the rigid wall surface and the pressure-receiving rubber plate in a minute space. It is desirable that the distance is substantially constant throughout. As a result, when the pressure in the pressure receiving chamber increases, the pressure receiving rubber plate can be brought into substantial contact with the rigid wall surface quickly throughout the whole, and the restraint of the pressure receiving rubber plate is further stabilized. Can be realized.

(Aspect 2 of the present invention)
A feature of aspect 2 of the present invention is that, in the fluid filled type vibration damping device according to aspect 1 of the present invention, the volume of the minute space is such that the internal pressure of the pressure receiving chamber is substantially equal to the atmospheric pressure. It is that it is 1 cc or less below.

  In this aspect, the volume expansion of the minute space is reduced, so that the pressure-receiving rubber plate can be more quickly and firmly restrained by the rigid wall surface when the pressure in the pressure-receiving chamber increases during vibration input. Thus, the amount of fluid flow through the orifice passage accompanying the pressure variation in the pressure receiving chamber can be more effectively ensured.

(Aspect 3 of the present invention)
A feature of aspect 3 of the present invention is that in the fluid filled type vibration damping device according to aspect 1 or 2 of the present invention, the rigid wall surface is a bottomed recess that opens toward the pressure receiving chamber. On the other hand, the pressure-receiving rubber plate is configured with a shape that protrudes outward from the pressure-receiving chamber along the shape of the rigid wall surface, and along the rigid wall surface that has a bottomed recess shape, The pressure receiving rubber plate is provided.

  In this embodiment, the elastic deformation of the pressure-receiving rubber plate toward the outside of the pressure-receiving chamber is effectively limited by the expansion rigidity in the tensile direction of the pressure-receiving rubber plate and the substantial contact with the rigid wall surface. The pressure fluctuation of the pressure receiving chamber at the time of vibration input is efficiently generated, but when negative pressure is generated in the pressure receiving chamber when a load is applied in the shocking rebound direction, the pressure receiving rubber plate is moved in the compression direction. In addition to this deformation, a deformation that collapses inward is generated, and the generation of the negative pressure in the pressure receiving chamber is eliminated as quickly as possible due to this deformation. Therefore, it is possible to effectively suppress the generation of bubbles due to the negative pressure in the pressure receiving chamber without increasing the size of the pressure receiving rubber plate.

(Aspect 4 of the present invention)
A feature of aspect 4 of the present invention is that in the fluid-filled vibration isolator according to any one of aspects 1 to 3 of the present invention, a part of the first mounting member is exposed to the pressure receiving chamber. The pressure-receiving rubber plate is disposed on the exposed surface of the first mounting member to the pressure-receiving chamber.

  In such a mode, the rigid wall surface provided on the opposite side of the pressure receiving chamber across the pressure receiving rubber plate is the surface exposed to the pressure receiving chamber of the first mounting member without providing another member. It can be easily secured by use, and the structure can be simplified.

(Aspect 5 of the present invention)
A feature of aspect 5 of the present invention is that, in the fluid filled type vibration damping device according to any one of aspects 1 to 4 of the present invention, the second mounting member is formed in a cylindrical shape, and one opening side thereof The first mounting member is disposed on the one side and the one opening is fluid-tightly covered with the main rubber elastic body, while the other opening of the second mounting member is fluidized with the flexible membrane. Further, the partition member supported by the second mounting member is disposed between the opposing surfaces of the main rubber elastic body and the flexible membrane, and one axial direction sandwiching the partition member is provided. The pressure receiving chamber is formed on the side and the equilibrium chamber is formed on the other side in the axial direction, and the orifice passage communicating the pressure receiving chamber and the equilibrium chamber is formed by the partition member, and the first mounting member Is exposed to the pressure receiving chamber and is exposed to the exposed portion of the first mounting member. It lies in the disposed pressure rubber plate.

  In this embodiment, the pressure receiving chamber, the equilibrium chamber, and the orifice passage can be formed compactly with a small number of parts by using the partition member. In addition, a space for arranging the pressure-receiving rubber plate can be secured by skillfully utilizing the exposed portion of the first mounting member exposed to the pressure-receiving chamber.

  As is clear from the above description, in the fluid-filled vibration isolator constructed according to the present invention, the pressure-receiving rubber plate quickly follows and deforms when a sudden negative pressure is applied to the pressure-receiving chamber. Thus, the generated negative pressure can be suppressed, and the generation of bubbles in the pressure receiving chamber can be effectively suppressed. In addition, since the amount of elastic deformation in the bulging direction is sufficiently suppressed by the rigid wall surface, the pressure-receiving rubber plate effectively causes pressure fluctuations in the pressure-receiving chamber to flow through the orifice passage during vibration input. Therefore, the vibration isolation effect based on the fluid action of the fluid can be effectively exhibited.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings. First, FIG. 1 shows an automobile engine mount 10 as an embodiment of the present invention. The 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 elastically connected by a main rubber elastic body 16. The first mounting bracket 12 is attached to the power unit of the automobile while the second mounting bracket 14 is attached to the body of the automobile so that the power unit is supported on the body against vibration. Note that, in such a mounted state, the main rubber elastic body 16 is elastically deformed due to the weight of the power unit, and the first mounting bracket 12 and the second mounting bracket 14 are positioned close to each other. Further, under such a mounted state, main vibrations to be vibrated are input in the approaching / separating direction of the first mounting bracket 12 and the second mounting bracket 14 (in the right diagonal direction in FIG. 1 which is the mount center axis). The Rukoto.

  More specifically, the first mounting bracket 12 has a substantially inverted truncated conical block shape, and is integrally formed with a threaded portion 18 protruding upward from the end surface on the large diameter side. The first mounting bracket 12 is fixedly attached to a power unit (not shown) through a screw hole provided in the screwing portion 18. Further, a flange-like stopper portion 20 that protrudes radially outward is integrally formed on the outer peripheral surface of the large-diameter end portion of the first mounting member 12.

  The second mounting member 14 has a large-diameter, generally cylindrical shape, and has a tapered portion 22 that gradually expands outward in the axial direction with respect to the opening side end on the upper side in the axial direction. A flange-shaped portion 24 that extends outward in the radial direction is integrally formed at the opening periphery of the tapered portion 22. Furthermore, a caulking portion 26 extending downward in the axial direction is integrally formed at the opening side end portion of the second mounting member 14 in the axial direction lower side.

  Further, the first mounting bracket 12 is arranged in a state of extending in the direction perpendicular to the axis, spaced apart upward in the axial direction on the substantially central axis of the second mounting bracket 14, so that they are opposed to each other in the axial direction. In addition, a main rubber elastic body 16 is interposed between the opposing surfaces of the first mounting bracket 12 and the second mounting bracket 14. The main rubber elastic body 16 has a substantially frustoconical shape, and has a tapered cylindrical outer peripheral surface that gradually decreases in diameter toward the upper side in the axial direction. The first mounting bracket 12 is vulcanized and bonded in a state where the main rubber elastic body 16 is inserted downward in the axial direction from the small diameter side end face of the main rubber elastic body 16, and is attached to the small diameter side end face of the main rubber elastic body 16. The first mounting bracket 12 is vulcanized and bonded to the lower surface of the stopper portion 20. Further, the second mounting bracket 14 is superimposed on the inner peripheral surface of the tapered portion 22 and vulcanized and bonded to the outer peripheral surface of the large-diameter side end portion of the main rubber elastic body 16. In short, in the present embodiment, the main rubber elastic body 16 is an integrally vulcanized molded product that is vulcanized and bonded to the outer peripheral surface of the first mounting bracket 12 and the inner peripheral surface of the second mounting bracket 14. -ing Further, a buffer rubber 28 protrudes upward in the axial direction at the stopper portion 20 of the first mounting member 12 and is integrally formed with the main rubber elastic body 16.

  In this integrally vulcanized molded product, an internal recess that is fluid-tightly closed by the main rubber elastic body 16 on the upper side in the axial direction of the second mounting bracket 14 and opens downward in the axial direction. 30 is formed. A thin seal rubber layer 32 integrally formed with the main rubber elastic body is vulcanized and bonded to the inner peripheral surface of the second mounting bracket 14 over substantially the entire surface thereof.

  Furthermore, a stopper cylinder 34 is attached above the second attachment 14 in the axial direction. The stopper cylinder 34 has a substantially cylindrical shape, and a large-diameter cylindrical caulking portion 36 that extends downward in the axial direction via a tapered portion that gradually expands downward in the axial direction at the lower end in the axial direction. It is integrally formed. Further, an annular contact protrusion 38 protruding inward in the radial direction is integrally formed on the upper end portion in the axial direction of the stopper tube metal 34. Then, the stopper tube bracket 34 is covered from the upper side in the axial direction of the second mounting bracket 14, and the flange-like portion 24 of the second mounting bracket 14 is caulked and fixed by the caulking portion 36 of the stopper tube bracket 34. The abutment projection 38 of the stopper barrel 34 is fixed to the second mounting bracket 14 and is opposed to the stopper portion 20 of the first mounting bracket 12 while being spaced apart upward in the axial direction. Yes. As a result, when a large vibration load is input, the stopper portion 20 abuts against the abutment protrusion 38 via the cushioning rubber 28, thereby rebounding the first mounting bracket 12 and the second mounting bracket 14 ( The relative displacement in the axial separation direction is limited.

  On the other hand, a diaphragm 40 made of a thin rubber film as a flexible film is disposed in the opening portion in the axial direction of the second mounting member 14. The diaphragm 40 has a thin disk shape that is slack so that it can be easily deformed, and a ring fitting 42 having a substantially annular plate shape is vulcanized and bonded to the outer peripheral edge portion. The ring fitting 42 is inserted into the lower end opening of the second mounting bracket 14 and fixed by caulking at the caulking portion 26, so that the diaphragm 40 is fixed to the second mounting bracket 14. Thus, the axially lower opening of the second mounting bracket 14 is fluid-tightly covered by the diaphragm 40, and the main rubber elastic body 16 and the diaphragm 40 that covers both axial sides of the second mounting bracket 14 are covered. A fluid chamber 44 in which an incompressible fluid is enclosed is formed between the opposing surfaces. As the sealing fluid, water, alkylene glycol, polyalkylene glycol, silicone oil, or the like is employed. In order to advantageously obtain a vibration isolation effect based on the resonance action of the fluid described later, in this embodiment, 0 is used. A low-viscosity fluid of 1 Pa · s or less is preferably employed.

  In addition, a bottom metal fitting 46 is disposed in the lower opening of the second attachment metal 14 and is assembled so as to cover the outside of the diaphragm 40. The bottom metal fitting 46 has a substantially bottomed cylindrical shape, and at one end in the axial direction thereof, a flange-shaped portion that extends radially outward via a tapered portion that gradually expands downward in the axial direction. While 48 is integrally formed, a mounting bolt 50 protruding downward in the axial direction is fixed to the bottom wall portion thereof. Further, the peripheral wall portion of the bottom metal fitting 46 is inclined at a predetermined inclination angle with respect to the horizontal direction (left and right in FIG. 1). Furthermore, the bottom metal fitting 46 is externally fitted to the second mounting metal fitting 14, and the flange-like portion 48 is overlapped with the flange-like portion 24 of the second attachment metal fitting 14 and is caulked and fixed by the caulking portion 26. The second mounting bracket 14 is fixed. Then, the mounting bolt 50 of the bottom metal fitting 46 is fixed to a vehicle body (not shown), so that the second fitting metal 14 is attached to the vehicle body via the bottom metal fitting 46. In the present embodiment, the mount body including the integrally vulcanized molded body of the main rubber elastic body 16 and the diaphragm 40 is secured to the vehicle body so that the bottom wall portion of the bottom metal fitting 46 extends in a substantially horizontal direction. However, it is inclined with respect to the vehicle body at a predetermined inclination angle in the horizontal direction. In addition, the bottom metal fitting 46 is provided with a communication hole or the like that allows the space between the diaphragm 40 and the bottom metal fitting 46 to communicate with the outside.

  Further, a partition member 52 is accommodated in the second mounting bracket 14 and assembled in the fluid chamber 44. The partition member 52 has a substantially thick disk shape as a whole, and the partition member 52 is fixed to the second mounting member 14 in a state where the partition member 52 extends in the direction perpendicular to the axis in the fluid chamber 44. Thus, the fluid chamber 44 is partitioned on both upper and lower sides with the partition member 52 interposed therebetween. On the upper side of the partition member 52, a pressure receiving chamber 54 in which a part of the wall part is configured by the main rubber elastic body 16 is formed, while on the lower side of the partition member 52, a part of the wall part is formed. An equilibrium chamber 56 composed of the diaphragm 40 is formed. That is, in the pressure receiving chamber 54, vibration is input along with elastic deformation of the main rubber elastic body 16 when vibration is input, and an internal pressure fluctuation is generated, while the equilibrium chamber 56 is based on deformation of the diaphragm 40. Thus, the volume change is easily allowed and the internal pressure change is absorbed.

  The partition member 52 is formed as one assembly in which the partition member main body 58 and the holding metal fitting 60 are press-fitted and fixed to each other, and a movable rubber plate 62 is incorporated between the partition member main body 58 and the holding metal fitting 60. Yes. The partition member main body 58 has a thick, substantially disk shape, and a circular central recess 64 that opens downward is formed at the center thereof. Further, an annular stepped portion 66 extending in the radial direction is formed at the opening peripheral edge portion of the central recess 64. In addition, a circumferential groove 70 is formed in the outer peripheral portion of the partition member main body 58 so as to open to the outer peripheral surface and extend in a spiral shape with a length of one or more rounds in the circumferential direction. One end of the circumferential groove 70 is communicated with the pressure receiving chamber 54 through the communication hole 72, while the other end of the circumferential groove 70 is communicated with the equilibrium chamber 56 through the notch 74. As a result, a first orifice passage 82 that communicates the pressure receiving chamber 54 and the equilibrium chamber 56 with each other is formed.

  The movable rubber plate 62 has a disc shape with a predetermined thickness, and the outer peripheral edge portion has a thick ring shape. The movable rubber plate 62 is disposed in an opening downward from the central recess 64 of the partition member main body 58, and an outer peripheral edge thereof is provided between the stepped portion 66 of the partition member main body 58 and the partition member main body 58. By being sandwiched between the holding fitting 60 that is press-fitted and fixed, the opening of the central recess 64 is fluid-tightly covered and disposed in a stretched state.

  Thus, the partition member 52 formed by assembling the partition member main body 58, the holding bracket 60, and the movable rubber plate 62 together is the lower side in the axial direction of the second mounting bracket 14. The upper end of the partition member main body 58 is overlapped with the lower end of the main rubber elastic body 16 and positioned. Further, by drawing the second mounting bracket 14, the outer peripheral surface of the partition member main body 58 is assembled in close contact with the inner peripheral surface of the second mounting bracket 14 via the seal rubber layer 32. ing. Furthermore, the lower end portion of the holding metal fitting 60 overlapped with the opening end portion of the partition member main body 58 is overlapped with the upper end portion of the ring metal fitting 42 fitted into the lower end opening portion of the second mounting fitting 14. The ring fitting 42 is fitted and fixed in a fluid-tight manner by drawing the second mounting fitting 14. Thereby, the partition member 52 is fixed and assembled to the intermediate portion in the axial direction inside the second mounting bracket 14.

  Further, in the partition member 52, the central recess 64 is fluid-tightly covered with the movable rubber plate 62, thereby forming a sub liquid chamber 78 in which a part of the wall portion is configured by the movable rubber plate 62. ing. The sub-liquid chamber 78 is filled with an incompressible fluid, like the pressure receiving chamber 54 and the equilibrium chamber 56. Although not clearly shown in the drawing, the intermediate portion in the longitudinal direction of the first orifice passage 82 communicates with the sub liquid chamber 78, and a pressure receiving pressure is obtained by using a part of the first orifice passage 82. A second orifice passage 84 is formed to communicate the chamber 54 and the auxiliary liquid chamber 78 with each other.

  In particular, in this embodiment, the engine shake is caused by the resonance action of the fluid that flows through the first orifice passage 82 based on the relative pressure fluctuation generated between the pressure receiving chamber 54 and the equilibrium chamber 56 at the time of vibration input. In order to exhibit an effective anti-vibration effect against a low-frequency large-amplitude vibration of about 10 Hz such as, the ratio of the cross-sectional area of the first orifice passage 82: A1 to the passage length: L1: A1 / L1 The value is set appropriately.

  Further, in the present embodiment, idling is caused by the resonance effect of the fluid that flows through the second orifice passage 84 based on the relative pressure fluctuation generated between the pressure receiving chamber 54 and the sub liquid chamber 78 when vibration is input. The ratio of the cross-sectional area of the second orifice passage 84: A2 to the passage length: L2 so that an effective anti-vibration effect is exerted against high-frequency small-amplitude vibration of about 20 to 40 Hz such as vibration: A2 / The value of L2 is set appropriately.

  In the present embodiment, the lower end portion in the axial direction of the first mounting member 12 extends downward in the axial direction and penetrates the internal recess 30 of the main rubber elastic body 16 and is exposed to the pressure receiving chamber 54. Yes. Further, a pocket-like recess 86 that opens toward the pressure receiving chamber 54 is formed in the exposed portion of the first mounting member 12. The recess 86 is a deep bottom circular recess having a hemispherical bottom surface. Further, the opening portion of the recess 86 is slightly enlarged in diameter to form a fitting hole 88. In the present embodiment, the first mounting member 12 is made of a highly rigid material such as a metal material or a hard synthetic resin material, so that the inner peripheral surface of the recess 86 has a rigid wall surface with a large rigidity. It is said that. In other words, the rigid wall surface provided in the portion exposed to the pressure receiving chamber 54 of the first mounting bracket 12 is a bottomed recess 86 that opens toward the pressure receiving chamber 54.

  Further, a pressure-receiving rubber film 90 as a pressure-receiving rubber plate is disposed on the exposed surface of the first mounting member 12 to the pressure-receiving chamber 54. The pressure-receiving rubber film 90 has a substantially bottomed cylindrical shape that is slightly smaller than the inner peripheral surface of the recess 86 and has a thin hemispherical shell shape as a whole. The opening end of the pressure-receiving rubber film 90 extends so as to spread radially outward over substantially the whole, and a substantially annular fitting 92 is vulcanized and bonded to the opening end surface. ing. Further, the pressure-receiving rubber film 90 is fitted into the recess 86 from the bottom, and the fitting 92 is press-fitted into the fitting hole 88 provided in the opening portion of the recess 86 to be fluid-tightly fitted. It is fixed. As a result, the pressure-receiving rubber film 90 is disposed on the first mounting member 12 with a shape that protrudes outward from the pressure-receiving chamber 54 along the bottomed recess shape of the recess 86. That is, a part of the wall portion different from the main rubber elastic body 16 in the pressure receiving chamber 54 is constituted by the pressure receiving rubber film 90.

  Furthermore, an air chamber 94 as a sealed minute space is formed between the opposing surfaces of the pressure-receiving rubber film 90 and the recess 86. A small amount of air is sealed in the air chamber 94. In the present embodiment, the operation of enclosing air into the air chamber 94 is not limited in any way. For example, the pressure-receiving rubber film 90 including the fitting 92 is press-fitted into the first fitting 12. It is suitably realized by performing fixing in the atmosphere. This is because the air chamber 94 is covered and an appropriate amount of air is easily and quickly sealed, and the recess 86 is sealed.

  In particular, in the present embodiment, when the mount 10 is assembled to an automobile, the volume V of the air chamber 94 is preferably V ≦ 1 cc or less, with the internal pressure of the pressure receiving chamber 54 being substantially equal to the atmospheric pressure. More preferably, it is set in the range of V ≦ 0.5 cc or less, more preferably 0 <V ≦ 0.3 cc. In addition, when the pressure receiving rubber film 90 reaches the internal pressure of the pressure receiving chamber 54 of 0.6 MPa, the air in the air chamber 94 is sufficiently compressed over the substantially entire recess 86 to the pressure receiving rubber film 90. By exerting a large deformation restraining force, the pressure-receiving rubber film 90 is superposed in a state where elastic deformation to the outside can be substantially prevented (see FIG. 1).

  On the other hand, the elastic deformation of the pressure-receiving rubber film 90 toward the pressure-receiving chamber 54 is relatively easily allowed due to the presence of the air chamber 94. As shown in FIG. 2, it is more easily generated with a deformation mode in which it is partially collapsed inward.

  In the engine mount 10 having the above-described structure, a part of the wall portion different from the main rubber elastic body 16 in the pressure receiving chamber 54 is formed with the recess 86 of the first mounting bracket 12 across the air chamber 94. In general, when a large vibration load such as cranking is input, particularly when a large or abrupt negative pressure is generated in the pressure receiving chamber 54, the pressure receiving rubber film 90 is configured to be opposed to the air. By utilizing the volume expansion of the chamber 94, a hydraulic pressure absorption effect based on elastic deformation of the pressure-receiving rubber film 90 is exhibited, and the pressure fluctuation to the negative pressure side caused in the pressure-receiving chamber 54 is reduced. . Therefore, the gas phase separation of the fluid caused by the shock pressure fluctuation to the negative pressure side is effectively suppressed, and the abnormal noise and vibration caused by the bubble generation are effectively reduced or suppressed. Therefore, an excellent quality engine mount can be provided.

  Moreover, in the present embodiment, in addition to the fact that the bag-shaped pressure-receiving rubber film 90 that protrudes outward from the pressure-receiving chamber 54 is disposed along the recess 86 having a bottomed recess shape. Since the volume V of the air chamber 94 is set to 1 cc or less, the pressure-receiving rubber film 90 is easily and quickly applied over substantially the entire recess 86 by a pressure increase of 0.6 MPa in the pressure-receiving chamber 54. Since the pressure-receiving rubber film 90 is prevented from bulging and deforming due to the contact state, the pressure fluctuation on the positive pressure side of the pressure-receiving chamber 54 is effectively generated. As a result, effective vibration fluctuations occur between the pressure receiving chamber 54 and the equilibrium chamber 56 at the time of vibration input to be damped required in the frequency range in which the first orifice passage 82 and the second orifice passage 84 are tuned. As a result, the amount of fluid flow through each of the orifice passages 82 and 84 is efficiently ensured, and a vibration isolation effect based on the resonance action of the fluid can be effectively exhibited.

  In particular, in this embodiment, since the bottom surface of the pressure-receiving rubber film 90 and the bottom surface of the recess 86 are both spherical, the pressure-receiving rubber film 90 is recessed when the pressure-receiving rubber film 90 contacts the recess 86. Since the elastic deformation is constrained by contact with the area 86 in a more reliable contact state, the bulging deformation of the pressure-receiving rubber film 90 is further effectively prevented.

  Furthermore, in this embodiment, the fitting fitting 92 vulcanized and bonded to the pressure-receiving rubber film 90 is press-fitted and fixed in the recess 86 of the first fitting 12 so that air is sealed in the air chamber 94. Therefore, for example, even when the pressure receiving rubber film 90, the recess 86, and the dimensions of the air chamber 94 are designed without particular consideration, the pressure receiving rubber film 90 is assembled in the recess 86 in the atmosphere. An air chamber 94 in which a certain amount of air is sealed is formed between the opposing surfaces of the pressure-receiving rubber film 90 and the recess 86. Therefore, there is no need to set the dimensions of the air chamber 94, the pressure-receiving rubber film 90, and the recess 86 particularly strictly, and it is not necessary to use special operations or devices. By forming 86, a mount having the desired characteristics can be easily realized.

  In the present embodiment, the partition member 52 that forms the first and second orifice passages 82, 84, and the like can be assembled in the atmosphere in advance, so that, for example, such an assembled partition is used. The target engine mount 10 can be easily manufactured by assembling the member 52 to the second mounting bracket 14 to which the main rubber elastic body 16 is vulcanized and bonded in a fluid.

  As mentioned above, although one embodiment of the present invention has been described in detail, this is merely an example, and the present invention is not limited to any specific description by this embodiment, and is based on the knowledge of those skilled in the art. The present invention can be implemented with various changes, modifications, improvements, etc., and all such embodiments are within the scope of the present invention without departing from the spirit of the present invention. Needless to say, there is.

  For example, in the embodiment described above, the recess provided on the surface exposed to the pressure receiving chamber of the first mounting bracket is a rigid wall surface, and is a deep circular recess that opens toward the inside of the pressure receiving chamber. In addition, the pressure-receiving rubber film has a bottomed cylindrical shape that opens toward the inside of the pressure-receiving chamber along the shape of the recess, but it is not limited to this form.

  Specifically, for example, a rigid wall surface is formed by the outer peripheral surface of the protrusion by providing the protrusion on the surface exposed to the pressure receiving chamber of the first mounting bracket so as to extend toward the pressure receiving chamber. In addition, one embodiment of the present invention may be realized by forming the pressure-receiving rubber film into a bottomed cylindrical shape that extends toward the pressure-receiving chamber so as to cover the entire protrusion. Alternatively, the flat surface exposed to the pressure receiving chamber of the first mounting bracket is a rigid wall surface, and the outer peripheral edge portion of the pressure receiving rubber film having a flat plate shape or the like is fixed to the flat surface, thereby flattening the pressure receiving rubber film. One embodiment of the present invention may be realized by forming an air chamber between the surfaces.

  In the above embodiment, the recess, the pressure-receiving rubber film, and the air chamber are provided on the exposed surface of the first mounting bracket to the pressure-receiving chamber. For example, the partition member, the second mounting bracket, etc. It is also possible to provide on the surface exposed to the pressure receiving chamber.

  Further, the size, shape, structure, and the like of the first orifice passage and the second orifice passage are appropriately set according to the required vibration isolation characteristics and the like, and are not limited at all.

  Further, the second orifice passage, the movable rubber plate, and the like are also provided as necessary and are not essential members.

  Furthermore, in the above-described embodiments, specific examples of applying the present invention to the engine mount inclined with respect to the vehicle have been shown. However, the engine mount horizontally arranged with respect to the vehicle and other various engines Of course, the present invention can be applied to the mount.

It is a longitudinal section explanatory view showing one operation form of an engine mount as one embodiment of the present invention. It is a longitudinal cross-sectional explanatory drawing which shows the principal part of the operation form different from the operation form of the engine mount in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine mount 12 1st mounting bracket 14 2nd mounting bracket 16 Main body rubber elastic body 40 Diaphragm 54 Pressure receiving chamber 56 Equilibrium chamber 82 First orifice passage 84 Second orifice passage 86 Recess 90 Pressure receiving rubber film 94 Air chamber

Claims (6)

A first mounting member and a second mounting member that are spaced apart from each other are connected by a main rubber elastic body, and a wall is formed by a pressure receiving chamber in which a part of the wall portion is configured by the main rubber elastic body and a flexible film. A fluid enclosure in which an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber, respectively, and the pressure receiving chamber and the equilibrium chamber are connected to each other through an orifice passage. In the type vibration isolator,
A part of the wall portion different from the main rubber elastic body in the pressure receiving chamber is constituted by a thin pressure receiving rubber plate, and on the opposite side of the pressure receiving chamber across the pressure receiving rubber plate, the pressure receiving rubber plate Forming a rigid wall surface extending along the opposite surface of the pressure-receiving rubber plate and the rigid wall surface to form a sealed micro space that is cut off from the external space, and the internal pressure of the pressure-receiving chamber reaches 0.6 MPa. Thus, the elastic deformation of the pressure-receiving rubber plate outward from the pressure-receiving chamber is prevented by substantial contact with the rigid wall surface, while the pressure-receiving rubber plate is inwardly directed toward the pressure-receiving chamber. A fluid-filled vibration damping device characterized in that elastic deformation is allowed based on the volume expansion of the minute space.   2. The fluid filled type vibration damping device according to claim 1, wherein the volume of the minute space is set to 1 cc or less in a state where the internal pressure of the pressure receiving chamber is substantially equal to the atmospheric pressure.   While the rigid wall surface is a bottomed recess that opens toward the pressure receiving chamber, the pressure receiving rubber plate has a shape that protrudes outward from the pressure receiving chamber along the shape of the rigid wall surface. The fluid-filled vibration isolator according to claim 1 or 2, wherein the pressure-receiving rubber plate is disposed along the rigid wall surface having a bottomed recess shape.   4. A part of the first mounting member is exposed to the pressure receiving chamber, and the pressure receiving rubber plate is disposed on a surface of the first mounting member exposed to the pressure receiving chamber. The fluid-filled vibration isolator according to any one of the above.   The second mounting member has a cylindrical shape, and the first mounting member is disposed on one opening side of the second mounting member, and the one opening is covered fluid-tightly with the main rubber elastic body, The other opening of the second mounting member is fluid-tightly covered with the flexible film, and the partition member supported by the second mounting member is opposed to the main rubber elastic body and the flexible film. The pressure receiving chamber is formed on one side in the axial direction with the partition member disposed between the surfaces, the equilibrium chamber is formed on the other side in the axial direction, and the pressure receiving chamber communicates with the equilibrium chamber. An orifice passage is formed by the partition member, the first mounting member is exposed to the pressure receiving chamber, and the pressure receiving rubber plate is disposed in an exposed portion of the first mounting member. The fluid-filled vibration isolator according to any one of the above.   The main body rubber when the pressure variation of the pressure receiving chamber at the time of vibration input between the first mounting member and the second mounting member is caused by relative displacement between the first mounting member and the second mounting member. The fluid filled type vibration damping device according to any one of claims 1 to 5, wherein the vibration filled type vibration damping device is directly generated with respect to the pressure receiving chamber in accordance with elastic deformation of the elastic body.

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