JP4914817B2 - Fluid filled vibration isolator - Google Patents

Description

  The present invention relates to a vibration-isolating device that is interposed between members to be anti-vibrated and uses a vibration-insulating effect based on a fluid action of a fluid enclosed inside.

  Conventionally, as a type of vibration isolator which is interposed between members constituting the vibration transmission system and mutually supports the vibration isolation connection or vibration isolation, it is based on the flow action of the fluid sealed inside. A fluid-filled vibration isolator using a vibration effect is known. This fluid-filled vibration isolator has a structure in which a first mounting member and a second mounting member are spaced apart from each other and connected by a main rubber elastic body. Furthermore, on the inner peripheral side of the second mounting member, a pressure receiving chamber in which a part of the wall is made of a main rubber elastic body and an equilibrium chamber in which a part of the wall is made of a flexible film are formed. The incompressible fluid is sealed in both the chambers, and the pressure receiving chamber and the equilibrium chamber are connected to each other through the orifice passage.

  Based on the fluid action of the fluid that is caused to flow between the pressure receiving chamber and the equilibrium chamber through the orifice passage, an excellent anti-vibration effect is exhibited against vibrations in a specific frequency range. Such a fluid-filled vibration isolator has been studied for application to, for example, automobile engine mounts, body mounts, suspension member mounts, and the like.

  In such a fluid filled type vibration isolator, an excellent anti-vibration effect is exhibited when the vibration of the orifice passage is pre-tuned at a frequency, while a desired anti-vibration effect is obtained when the vibration is input in another frequency range. There has been a problem that cannot be effectively demonstrated. However, since vibrations in multiple frequency ranges may be simultaneously input to the fluid-filled vibration isolator, demands for vibration isolating performance are increasing in recent years. There is a need for a fluid-filled vibration isolator that exhibits an effective vibration isolating effect.

  By the way, the fluid filled type vibration isolator has a problem that abnormal noise and vibration are generated when a shocking heavy load is input. Specifically, for example, when a fluid-filled vibration isolator is used as an engine mount of an automobile, vibrations or abnormal noises that can be felt by the occupant when the automobile travels on an uneven wavy road, etc. It may occur.

  As a cause of occurrence of such abnormal noise and vibration, there is a cavitation phenomenon due to a rapid pressure fluctuation in the pressure receiving chamber. That is, when the main rubber elastic body constituting the wall of the pressure receiving chamber is greatly elastically deformed by an input of a shocking large load and the hydraulic pressure in the pressure receiving chamber is significantly reduced, bubbles that are understood as cavitation are generated. . And it is thought that the abnormal noise and vibration which will be a problem will be produced in a vehicle interior, when the water hammer pressure which generate | occur | produces when this bubble collapses is transmitted to a vehicle via a vibration isolator.

  Therefore, in order to prevent the generation of abnormal noise and vibration due to such cavitation, for example, Patent Document 1 (Patent No. 2805305) arranges a pressure receiving chamber filled with an incompressible fluid and an equilibrium chamber. There has been proposed a fluid-filled vibration isolator having a structure in which a slit is formed in a provided rubber film. That is, in the fluid-filled vibration isolator described in Patent Document 1, when an excessive negative pressure is generated in the pressure receiving chamber, the rubber film is sucked into the pressure receiving chamber and elastically deformed to form the rubber film. The pressure receiving chamber and the equilibrium chamber are communicated with each other through the slit, and the negative pressure in the pressure receiving chamber is quickly eliminated, preventing abnormal noise and vibration due to cavitation. It is supposed to be.

  However, the fluid-filled vibration isolator described in Patent Document 1 still has a problem that cannot be solved. First, as shown in Patent Document 1, when a slit is formed in the rubber film that separates the pressure receiving chamber and the equilibrium chamber, not only when negative pressure is applied to the pressure receiving chamber, but also positive pressure is applied to the pressure receiving chamber. In some cases, the slit may open, and the pressure receiving chamber and the equilibrium chamber may be short-circuited through the slit. Therefore, even when a normal load that is subject to vibration isolation is input, the fluid pressure in the pressure receiving chamber is released to the equilibrium chamber, thereby reducing the amount of fluid that can be flowed through the orifice passage, and the fluid flow action. There is a possibility that the vibration-proofing effect to be exhibited based on the above cannot be obtained effectively.

  As one means for solving such a problem, for example, it may be possible to make the slit difficult to open by increasing the rigidity by, for example, making the rubber film thick and limiting the elastic deformation of the rubber film. . However, if the rigidity of the rubber film is sufficiently increased, the desired vibration isolation effect can be realized, but the slit opening amount may not be sufficiently obtained even when an excessive negative pressure that should open the slit is generated. There is a problem that the effect of reducing the above-mentioned abnormal noise and vibration is reduced.

  It is also conceivable to reduce the size of the slit to make it difficult to open the slit so that the desired vibration-proof performance can be realized during normal load input. However, if the slit is made small, there is a possibility that the negative pressure eliminating effect that should be exhibited when an excessive negative pressure is generated in the pressure receiving chamber cannot be obtained effectively. That is, when the input load is very large and a significantly large negative pressure is generated in the pressure receiving chamber, the negative pressure in the pressure receiving chamber is not sufficiently eliminated due to the insufficient opening area of the slit, resulting in cavitation. There is a risk of causing abnormal noise or vibration.

  In short, the fluid-filled vibration isolator disclosed in Patent Document 1 can effectively reduce and eliminate abnormal noise and vibration caused by cavitation, and effectively obtain the original vibration isolating performance of the target vibration isolator. It was difficult.

Patent No. 2805305

  Here, the present invention has been made in the background as described above, and the problem to be solved is to provide a desired vibration isolation effect when inputting normal vibration isolation vibrations in a wide frequency range. It is possible to reduce the occurrence of abnormal noise and vibration due to cavitation as soon as possible when the shock input is high enough to cause cavitation. An object of the present invention is to provide a fluid-filled vibration isolator having a novel structure.

  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. 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, according to the present invention, the first mounting member and the second mounting member are connected by the main rubber elastic body, and the pressure receiving chamber and the flexible membrane each having a part of the wall portion configured by the main rubber elastic body. A fluid enclosure that forms an equilibrium chamber with a part of the wall and encloses the incompressible fluid in the pressure receiving chamber and the equilibrium chamber, and has an orifice passage communicating the pressure receiving chamber and the equilibrium chamber with each other. In the vibration isolator, a communication passage that communicates the pressure receiving chamber and the equilibrium chamber is provided to a partition member that partitions the pressure receiving chamber and the equilibrium chamber, and the communication passage is overlapped with the communication passage from the pressure receiving chamber side. A closing rubber elastic plate for closing the pressure is provided so that the pressure of the pressure receiving chamber is applied to one surface of the closing rubber elastic plate and the pressure of the equilibrium chamber is applied to the other surface. On the other hand, the outer peripheral portion of the closing rubber elastic plate In addition, by providing a restraining means for holding the partition member in contact with the partition member, a positive pressure of the pressure receiving chamber is exerted on the block rubber elastic plate so that the block rubber elastic plate is against the partition member. While being pressed to block the communication path, the negative pressure of the pressure receiving chamber is exerted on the closing rubber elastic plate, so that a region of the outer peripheral portion of the closing rubber elastic plate that is out of the holding portion by the restraining means is removed. A communication / blocking control means for elastically deforming from the partition member in a direction away from the partition member and allowing the communication path to communicate with each other is configured.

  In such a fluid-filled vibration isolator having a structure according to the present invention, when a negative pressure is generated in the pressure receiving chamber, the closing rubber elastic plate is elastically deformed by the negative pressure of the pressure receiving chamber acting, and the communication path Can communicate with each other. As a result, the sealed fluid is caused to flow between the pressure receiving chamber and the equilibrium chamber through the communication path, and the negative pressure in the pressure receiving chamber is eliminated as quickly as possible. Therefore, it is possible to effectively prevent the generation of abnormal noise and vibration that may be caused by excessive pressure drop in the pressure receiving chamber.

  In addition, the communication passage is communicated by the pressure of the pressure receiving chamber being reduced, and the negative pressure in the pressure receiving chamber is eliminated by the fluid flow through the communication passage, so that the substantial wall of the pressure receiving chamber is reduced. The spring stiffness can be changed. Thereby, the tuning of the orifice passage is changed, and an excellent vibration-proofing effect based on the fluid flow action is exerted against input vibrations in a wider frequency range.

  In the fluid filled type vibration damping device according to the present invention, the closing rubber elastic plate may be fixed to the partition member at a central portion thereof.

  In this way, by fixing the central portion of the closing rubber elastic plate to the partition member, the elastic deformation of the central portion of the closing rubber elastic plate is limited, and the internal pressure of the pressure receiving chamber is excessively absorbed by the deformation of the closing rubber elastic plate. Can be prevented.

  Further, in the fluid filled type vibration damping device according to the present invention, a reinforcing member having a plurality of spoke-like portions extending radially from a central portion toward an outer peripheral portion is provided in the closed rubber elastic plate, and the restraining means May be configured to include the reinforcing member.

  As described above, the reinforcing member having the spoke-like portion extending from the central portion toward the outer peripheral portion is provided on the closing rubber elastic plate, so that the outer peripheral portion of the closing rubber elastic plate is arranged on the periphery of the partition member. It is also possible to constitute a restraining means for holding the contacted state at a location. According to this, when a large negative pressure is applied to the pressure receiving chamber, a region outside the fixing portion of the reinforcing member is elastically deformed in the outer peripheral portion of the closing rubber elastic plate, and the elastic passage is allowed to pass through the communication path. The negative pressure elimination effect due to fluid flow is effectively exhibited. Therefore, it is possible to prevent the generation of abnormal noise and vibration due to cavitation.

  In addition, by providing a plurality of spoke-like portions extending radially with respect to the closing rubber elastic plate, the amount of elastic deformation of the region positioned between the spoke-like portions in the closing rubber elastic plate depends on the degree of negative pressure. Are adjusted appropriately. Therefore, it is possible to prevent the internal pressure of the pressure receiving chamber from being released more than necessary, the wall spring rigidity of the pressure receiving chamber is changed according to the opening area of the communication passage, and the tuning of the orifice passage according to the input vibration. Is automatically adjusted. Therefore, it is possible to effectively obtain a target vibration-proofing effect with respect to vibration input in a wider frequency range including vibration at a frequency lower than the original tuning frequency of the orifice passage.

  The reason why the function of adjusting the opening area of the communication path is realized is that the spoke-like portions extend radially, so that the region positioned between the spoke-like portions is located on the radial center side. It is conceivable that the effective free length in the circumferential direction becomes smaller as it goes and it is difficult for elastic deformation to occur. Thus, when an excessive negative pressure is applied to the pressure receiving chamber, it is possible to prevent the communication passage from being opened more than necessary, and as the negative pressure applied to the pressure receiving chamber increases, the closing rubber elastic plate In this case, the region where the fixing portion of the reinforcing member is removed is elastically deformed to the inner peripheral side, and the opening area of the communication passage is ensured as much as necessary to eliminate the negative pressure. Therefore, the negative pressure exerted on the pressure receiving chamber is sufficiently released through the communication path, and abnormal noise and vibration due to cavitation are effectively suppressed, and the internal pressure of the pressure receiving chamber is prevented from being released more than necessary, and the orifice The anti-vibration effect due to fluid flow through the passage is exhibited in a wider frequency range.

  Further, in the fluid-filled vibration isolator according to the present invention, when a closed rubber elastic plate provided with a reinforcing member is employed, the reinforcing member is disposed at the outer peripheral side tip portion of the spoke-like portion. It is possible to preferably employ a structure that integrally includes a split rim-like portion extending in the circumferential direction.

  Thus, by adopting the reinforcing member provided with the split rim-shaped portion at the outer peripheral side tip portion of the spoke-shaped portion, the portion where the split rim-shaped portion is provided in the outer peripheral edge portion of the closing rubber elastic plate is used as the partition member. It can be firmly held in the abutted state. Therefore, the closed state of the communication passage during normal vibration input is more advantageously maintained, and a large amount of fluid flowing through the orifice passage can be secured. Accordingly, it is possible to effectively obtain the original vibration isolation effect of the target vibration isolation device.

  Furthermore, in the fluid filled type vibration damping device according to the present invention, when a structure having a reinforcing member is adopted, the reinforcing member is constituted by a leaf spring, and the leaf spring is part of the partition member. It may be fixed.

  Since the reinforcing member is constituted by a leaf spring, excessive elastic deformation of the closing rubber elastic plate is effectively prevented by the elastic force of the leaf spring. As a result, the pressure fluctuation in the pressure receiving chamber is prevented from being unnecessarily released to the equilibrium chamber side, and a sufficient amount of fluid can be ensured to flow through the orifice passage, so that the fluid flowing through the orifice passage can be secured. The vibration isolation effect based on the fluid action can be obtained more effectively. Therefore, it is possible to achieve the target vibration-proofing effect over a wide frequency range.

  Further, since the reinforcing member is constituted by a plate spring that can be elastically deformed, the portion of the closing rubber elastic plate provided with the reinforcing member is allowed to be elastically deformed. Thereby, when a remarkably large negative pressure is applied to the pressure receiving chamber, the fixed portion of the leaf spring in the closing rubber elastic plate is elastically deformed, and the communication path is communicated with a larger opening area. Therefore, it is possible to more effectively obtain the effect of reducing abnormal noise and vibration caused by cavitation.

  On the other hand, in the fluid filled type vibration damping device according to the present invention, when a structure having a reinforcing member is employed, the reinforcing member may be a rigid body.

  According to this, since the reinforcing member is a rigid body that does not substantially deform, the deformation amount of the closing rubber elastic plate can be effectively limited. In particular, by preventing deformation of the closing rubber elastic plate in the portion where the spoke-like portion is provided, the separation distance in the circumferential direction of the plurality of spoke-like portions, and hence the effective free length in the circumferential direction of the closing rubber elastic plate is radial. It is possible to adjust the opening area of the communication path using the fact that it is changed at a higher accuracy.

  Further, in the fluid filled type vibration damping device according to the present invention, the holding portion by the restraining means in the outer peripheral portion of the closed rubber elastic plate is larger than the negative pressure of the pressure receiving chamber that elastically deforms the area outside the holding portion. The communication path may be communicated by elastic deformation in the direction away from the partition member by the action of negative pressure.

  According to this, since the portion held by the restraining means is deformed in the direction away from the partition member, when the negative pressure of the pressure receiving chamber is applied and the communication path is communicated, the pressure receiving pressure The opening area of the communication passage can be changed in multiple stages according to the degree of pressure in the chamber. As a result, the effect of reducing pressure exerted on the pressure receiving chamber is exhibited in multiple stages, preventing cavitation when excessive negative pressure is generated in the pressure receiving chamber, and effective prevention in a wide frequency range during normal vibration input. The realization of the vibration effect can be achieved more effectively in a balanced manner.

  In particular, the communication / blocking control means can be operated in multiple stages, so that the magnitude of the hydraulic pressure in the pressure receiving chamber that escapes to the equilibrium chamber side through the communication path can be changed stepwise or continuously. It has become. Therefore, the vibration isolation effect based on the fluid action of the fluid that is caused to flow through the orifice passage is effectively exhibited over a wider frequency range.

  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 automotive engine mount 10 as an embodiment of a fluid filled type vibration damping device according to 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 connected to each other by a main rubber elastic body 16. The first mounting bracket 12 is attached to the power unit of the automobile that is one member constituting the vibration transmission system, and the second mounting bracket 14 is attached to the body of the automobile that is the other member constituting the vibration transmission system. By being attached, the power unit is connected to the vehicle body in a vibration-proof manner. In the following description, the vertical direction is the axial direction of the engine mount 10 and the vertical direction in FIG. 1, which is the main vibration input direction. FIG. 1 shows a state before the engine mount 10 is mounted on the vehicle. When the engine mount 10 is mounted on the vehicle, the shared support load of the power unit is exerted in the axial direction of the engine mount 10.

  More specifically, the first mounting member 12 is a highly rigid member made of iron, aluminum alloy or the like, and has a substantially circular block shape. The first mounting bracket 12 is integrally formed with a mounting bolt 18 that protrudes upward. For example, the first mounting bracket 12 is attached to the power unit by screwing the mounting bolt 18 to the power unit (not shown).

  The second mounting bracket 14 is a high-rigidity member made of the same material as the first mounting bracket 12 and has a thin, large-diameter, generally cylindrical shape. The second mounting member 14 has a flange-shaped portion 20 integrally formed at the upper end portion and a caulking piece 22 integrally formed at the lower end portion. And the 2nd attachment metal fitting 14 is attached to the vehicle body side via the bracket metal fitting etc. which are externally fixed by fixing.

  The first mounting bracket 12 and the second mounting bracket 14 are arranged such that the first mounting bracket 12 is spaced above the second mounting bracket 14 on the same central axis, and the main rubber elastic body 16 is mutually connected. It is connected with.

  The main rubber elastic body 16 is formed of a thick rubber elastic body having a substantially truncated cone shape, and a large-diameter recess 24 is formed at an end portion on the large-diameter side. The large-diameter recess 24 is a reverse mortar-like or hemispherical recess, and is open downward. In the main rubber elastic body 16, the opening peripheral edge of the large-diameter recess 24 extends downward.

  The first mounting bracket 12 is inserted from above and vulcanized and bonded to the small-diameter side end of the main rubber elastic body 16, and on the outer peripheral surface of the large-diameter side end of the main rubber elastic body 16. On the other hand, by vulcanizing and bonding the inner peripheral surface of the second mounting bracket 14, the first mounting bracket 12 and the second mounting bracket 14 are elastically connected to each other by the main rubber elastic body 16. The main rubber elastic body 16 in the present embodiment is formed as an integrally vulcanized molded product including the first mounting bracket 12 and the second mounting bracket 14.

  The main rubber elastic body 16 is integrally formed with a seal rubber layer 26. The seal rubber layer 26 is a rubber elastic body having a thin and large-diameter substantially cylindrical shape extending downward from the lower end portion of the main rubber elastic body 16, and is firmly fixed to the inner peripheral surface of the second mounting bracket 14. It has been. The seal rubber layer 26 has an inner diameter larger than that of the lower end portion of the main rubber elastic body 16, and an annular step portion 28 that is continuous in the circumferential direction is formed at the boundary between the main rubber elastic body 16 and the seal rubber layer 26. ing. Further, the seal rubber layer 26 in this embodiment is thinner than the upper side in the axial direction intermediate portion, and a step is formed in the axial direction intermediate portion on the inner peripheral surface of the seal rubber layer 26. Furthermore, the inner peripheral surface of the second mounting bracket 14 is covered with the main rubber elastic body 16 and the seal rubber layer 26 over substantially the entire length in the axial direction.

  In addition, a diaphragm 30 as a flexible film is disposed at the lower end of the second mounting bracket 14. The diaphragm 30 is a thin rubber film having a substantially disk shape or a substantially circular dome shape, and has sufficient slackness in the axial direction. An annular fixing portion 32 is integrally formed on the outer peripheral edge portion of the diaphragm 30.

  Further, the fixing bracket 34 is overlapped and fixed to the outer peripheral surface of the fixing portion 32. The fixing bracket 34 is a substantially ring-shaped bracket, and is a rigid body formed of the same material as the first and second mounting brackets 12 and 14. Then, a fixing portion 32 integrally formed with the diaphragm 30 is overlapped and vulcanized and bonded to the inner peripheral surface of the fixing bracket 34. Note that the diaphragm 30 in the present embodiment is formed as an integrally vulcanized molded product provided with a fixture 34.

  Such a diaphragm 30 is attached to the second mounting member 14. That is, the fixing bracket 34 fixed to the outer peripheral edge portion of the diaphragm 30 is overlapped with the lower end portion of the second mounting bracket 14 via the seal rubber layer 26, and the two-way aperture 14 with respect to the second mounting bracket 14. The fixed metal fitting 34 is fixed in close contact with the second mounting metal fitting 14 by performing a diameter reduction process such as the above. In the present embodiment, the lower end portion of the second mounting bracket 14 is bent toward the inner peripheral side, thereby being brought into contact with the lower end surface of the fixing bracket 34 and the fixing bracket 34 being removed in the axial direction. It is prevented.

  In this way, by attaching the diaphragm 30 to the second mounting bracket 14, there is an external surface between the opposing surfaces of the main rubber elastic body 16 and the diaphragm 30 on the inner peripheral side of the second mounting bracket 14. A fluid chamber 36 is formed which is separated from the space and encloses an incompressible fluid. The incompressible fluid sealed in the fluid chamber 36 is not particularly limited. For example, water, alkylene glycol, polyalkylene glycol, silicone oil, and a mixed solution thereof are preferably employed. . In particular, a low-viscosity fluid having a viscosity of 0.1 Pa · s or less is desirable in order to effectively obtain an anti-vibration effect based on the resonance action of the fluid described later.

  A partition member 38 is accommodated in the fluid chamber 36. The partition member 38 in the present embodiment includes an upper partition fitting 40 and a lower partition fitting 42. The upper partition fitting 40 is made of a metal such as an aluminum alloy and has a substantially disk shape as a whole. In addition, a circular central recess 44 that opens upward is formed in a central portion in the radial direction of the upper partition member 40.

  Further, an upper communication window 48 is formed on the bottom wall portion of the central recess 44 in the upper partition metal fitting 40. The upper communication window 48 is formed so as to penetrate in the radial intermediate portion in the bottom wall portion of the central recess 44. In the present embodiment, two upper communication windows 48 having a substantially semicircular shape when viewed in the axial direction are formed so as to face each other at a predetermined distance in the radial direction.

  A support protrusion 50 is integrally formed on the bottom wall portion of the central recess 44 in the upper partition metal fitting 40. The support protrusion 50 has a substantially cylindrical shape with a small diameter, and protrudes downward in the radial center of the upper partition fitting 40. Further, a fitting protrusion 52 is integrally formed at the tip of the support protrusion 50. The fitting protrusion 52 is a circular protrusion having a smaller diameter than the support protrusion 50, and protrudes downward from the central portion at the tip of the support protrusion 50.

  Further, an upper peripheral groove 54 is formed on the outer peripheral edge of the upper partition member 40. The upper circumferential groove 54 is a concave groove that is opened on the outer circumferential surface of the upper partition metal fitting 40 and extends in the circumferential direction with a predetermined length of slightly less than one round.

  On the other hand, the lower partition fitting 42 is formed of a metal such as an aluminum alloy like the upper partition fitting 40 and has a substantially disc shape as a whole. In addition, a circular housing recess 56 that opens upward is formed in the central portion in the radial direction of the lower partition metal fitting 42.

  In addition, a lower communication window 58 as a communication path is formed in the bottom wall portion of the housing recess 56 in the lower partition fitting 42. The lower communication window 58 has a substantially semicircular shape similar to that of the upper communication window 48 when viewed in the axial direction, and is formed such that the two lower communication windows 58 face each other at a predetermined distance in the radial direction. .

  Further, a lower notch 60 is formed at the outer peripheral edge of the lower partition fitting 42. The lower notch 60 opens to the outer peripheral surface and the upper surface of the lower partition metal fitting 42 and extends in the circumferential direction with a predetermined length of slightly less than one round.

  The upper partition fitting 40 and the lower partition fitting 42 having such a structure are stacked one above the other on the same central axis. The upper partition fitting 40 and the lower partition fitting 42 are positioned with respect to each other in the circumferential direction. The upper communication window 48 and the lower communication window 58 are positioned so as to overlap in the axial projection, and The end of the groove 54 and the end of the lower notch 60 are positioned so as to overlap in the axial projection.

  In addition, by combining the upper partition fitting 40 and the lower partition fitting 42 in an overlapping manner, the upper surface opening of the lower notch 60 formed in the lower partition fitting 42 is covered with the outer peripheral edge of the upper partition fitting 40. The lower cutout portion 60 has a groove shape opened to the outer peripheral side. Furthermore, a connection path is formed on the lower surface of the upper circumferential groove 54 at one end in the circumferential direction of the upper circumferential groove 54 and the lower notch 60 aligned with each other. As a result, the upper circumferential groove 54 and the lower notch 60 are communicated in series to form a circumferential groove that spirally extends with a length of less than two rounds.

  Further, by combining the upper partition fitting 40 and the lower partition fitting 42, the opening of the receiving recess 56 formed in the central portion of the lower partition fitting 42 is formed at the bottom of the central recess 44 formed in the upper partition fitting 40. Covered by the wall, an accommodation space 62 is formed between the upper partition fitting 40 and the lower partition fitting 42.

  The partition member 38 having such a structure is accommodated in the fluid chamber 36 as described above. That is, the partition member 38 has an opening on the side opposite to the opening on the side on which the main rubber elastic body 16 is fixed with respect to the second mounting bracket 14 before the diaphragm 30 is attached (the lower side in FIG. 1). The diaphragm 30 is inserted into the second mounting member 14 from below the partition member 38. The partition member 38 and the diaphragm 30 are supported by the second mounting bracket 14 by reducing the diameter of the second mounting bracket 14.

  When the partition member 38 is mounted on the second mounting bracket 14, the outer peripheral surface of the partition member 38 is brought into close contact with the second mounting bracket 14 via the seal rubber layer 26, and the fluid chamber 36 is formed in the partition member 38. It is divided up and down across. In other words, on one side (the upper side in FIG. 1) sandwiching the partition member 38, a part of the wall portion is constituted by the main rubber elastic body 16, and fluctuations in internal pressure are induced when vibration is input. 64 is formed. On the other hand, on the other side (the lower side in FIG. 1) sandwiching the partition member 38, an equilibrium chamber 66 is formed in which a part of the wall portion is constituted by the diaphragm 30 and volume change is easily allowed. Yes. The pressure receiving chamber 64 and the equilibrium chamber 66 are filled with an incompressible fluid.

  In addition, the peripheral groove formed in the outer peripheral edge of the partition member 38 has an opening on the outer peripheral side closed by the second mounting member 14 via the seal rubber layer 26, and forms a tunnel-like passage. In addition, an upper connection path 68 is formed at one end in the circumferential direction of the tunnel-shaped passage so as to pass through the upper side wall and open to the upper end surface of the outer peripheral edge of the upper partition member 40. Further, a lower connection path 70 is formed at the other circumferential end of the tunnel-shaped passage so as to pass through the lower side wall and open to the lower end surface of the outer peripheral edge of the lower partition fitting 42. As described above, the orifice passage 72 is formed in the outer peripheral edge portion of the partition member 38 so as to extend in a spiral shape with a predetermined length and communicate the pressure receiving chamber 64 and the equilibrium chamber 66 with each other.

  In the present embodiment, the orifice passage 72 has a vibration isolation effect based on the fluid flow action by appropriately setting the passage length and the passage cross-sectional area while paying attention to the rigidity of the wall spring of the pressure receiving chamber 64. It is tuned so as to be exerted against vibrations of around 10 Hz corresponding to automobile engine shake.

  Further, a lower communication window 58 formed in the lower partition fitting 42 is communicated with the equilibration chamber 66 in the central portion in the radial direction of the partition member 38, and the lower communication window 58 is connected to the accommodation space 62 and the upper communication window 48. The pressure receiving chamber 64 is communicated with each other. Thus, the pressure receiving chamber 64 and the equilibrium chamber 66 are communicated with each other through the lower communication window 58. In the present embodiment, the upper communication window 48, the accommodation space 62, and the lower communication window 58 constitute a short-circuit channel 73 that allows the pressure receiving chamber 64 and the equilibrium chamber 66 to communicate with each other.

  A movable rubber film 74 as a closing rubber elastic plate is disposed in the housing space 62 formed in the central portion of the partition member 38. As shown in FIGS. 3 and 4, the movable rubber film 74 is formed of a rubber elastic body having a substantially disk shape, and an annular contact protrusion 76 protruding downward is integrally formed on the outer peripheral portion. Is formed.

  The movable rubber film 74 is accommodated and disposed in the center in the radial direction of the accommodation space 62, and is superimposed from the pressure receiving chamber 64 side on the lower wall portion of the accommodation space 62 in which the lower communication window 58 is formed. . Further, the outer peripheral edge of the movable rubber film 74 is positioned on the outer peripheral side of the lower communication window 58 under the arrangement in the accommodation space 62, and the lower communication window 58 is covered with the movable rubber film 74. It is blocked.

  Furthermore, under the arrangement of the movable rubber film 74 on the partition member 38, the hydraulic pressure in the pressure receiving chamber 64 is applied to one surface of the movable rubber film 74 through the upper communication window 48. The fluid pressure in the equilibrium chamber 66 is applied to the other surface through the lower communication window 58.

  Further, the movable rubber film 74 in the present embodiment has a leaf spring 78 as a reinforcing member. The leaf spring 78 is a thin, substantially plate-shaped member formed of a metal such as iron or a hard synthetic resin, and as shown in FIG. 4, as a central restraint portion 80 and a spoke-like portion. The spoke-like spring portion 82 and the split rim-like portion 84 are provided. The leaf spring 78 has a spring constant larger than that of the rubber elastic body forming the movable rubber film 74 and is less likely to be deformed.

  More specifically, as shown in FIG. 4, the central restraining portion 80 has a substantially disk shape with a small diameter, and a circular fitting hole 86 is formed through the central portion. The fitting hole 86 is formed in a shape and size corresponding to the outer shape of the fitting projection 52 provided in the upper partition metal fitting 40.

  Further, the central restraining portion 80 is integrally formed with a spoke-like spring portion 82 that extends linearly toward the outer peripheral side. As shown in FIG. 4, the spoke-like spring portions 82 extend radially from the central restraint portion 80. In this embodiment, the three-spoke spring portions 82 are equally spaced from each other in the circumferential direction. So as to be separated from each other.

  A split rim-shaped portion 84 is integrally formed at the distal end portion on the outer peripheral side of the spoke-shaped spring portion 82. As shown in FIG. 4, the divided rim-shaped portion 84 has a curved longitudinal shape extending a predetermined length in the circumferential direction. Moreover, in this embodiment, the division | segmentation rim-like part 84 is each provided in the front-end | tip part of each spoke-like spring part 82, and is located mutually spaced apart in the circumferential direction.

  The leaf spring 78 having such a structure is fixed to the rubber elastic body of the movable rubber film 74. That is, the leaf spring 78 has a radially central portion exposed to the outside from the rubber elastic body of the movable rubber film 74, and an outer peripheral portion including the spoke-like spring portion 82 and the divided rim-like portion 84 has a movable rubber film. 74 is fixed in an embedded state in the rubber elastic body constituting 74. In other words, the outer peripheral edge portion of the central restraint portion 80, the spoke-like spring portion 82, and the split rim-like portion 84 are all embedded and fixed inside the rubber elastic body constituting the movable rubber film 74, and the central restraint portion. A central portion of the portion 80 is exposed to the outside through a circular hole formed in the central portion of the rubber elastic body. In the present embodiment, the movable rubber film 74 is formed as an integrally vulcanized molded product provided with a leaf spring 78.

  Here, when the movable rubber film 74 provided with the leaf spring 78 is accommodated in the accommodation space 62 and disposed in the center in the radial direction, the central restraining portion 80 constituting the central portion of the movable rubber film 74 is moved to the pair of lower portions. It is located between the facing of the communication window 58. The central portion of the central restraining portion 80 exposed to the outside is sandwiched and held between the support protrusion 50 and the lower wall surface of the housing space 62 and is integrally formed at the tip of the support protrusion 50. The fitted fitting portion 52 is fitted into a fitting hole 86 that penetrates the center of the central restraining portion 80. Thus, in the present embodiment, the leaf spring 78 is fixed to the partition member 38 at the radial center portion of the movable rubber film 74.

  Further, in the present embodiment, the contact protrusion 76 is integrally formed at a portion of the movable rubber film 74 positioned on the outer peripheral side of the lower communication window 58 and protrudes downward. Therefore, when the central portion in the radial direction of the movable rubber film 74 is sandwiched between the support protrusion 50 and the lower wall portion of the accommodation space 62, the central portion of the movable rubber film 74 is brought into contact with the support protrusion 50. It is pushed downward by the height of the strip 76. As a result, a downward biasing force in the axial direction based on the elastic force of the leaf spring 78 is applied to the portion of the movable rubber film 74 where the leaf spring 78 is fixed, and the leaf spring 78 in the movable rubber film 74 is moved. The fixed portion is pressed against the lower wall portion of the accommodation space 62.

  As described above, the restraining means in the present embodiment is realized by using the urging force of the leaf spring 78, and in a stationary state where no external load is applied, the outer peripheral portion of the movable rubber film 74 has a split rim shape. A plurality of portions on the circumference where the portion 84 is vulcanized and bonded are held in contact with the partition member 38.

  In the present embodiment, the rubber elastic body constituting the movable rubber film 74 is a region where the fixed portion of the divided rim-shaped portion 84 is removed from the outer peripheral portion of the movable rubber film 74 in a stationary state where no external load is applied. Based on this elastic force, the partition member 38 is held in contact.

  Further, the elastic force of the leaf spring 78 is set larger than the elastic force of the rubber elastic body constituting the movable rubber film 74 when the movable rubber film 74 is attached to the partition member 38. The urging force acting on the holding portion to which the leaf spring 78 is fixed is set larger than the urging force acting on the region outside the holding portion. As a result, the holding portion to which the leaf spring 78 is fixed at the outer peripheral portion of the movable rubber film 74 is pressed more firmly against the partition member 38 than the region outside the holding portion.

  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 64. Be born. The flow amount of the fluid through the orifice passage 72 is effectively secured by the difference in relative pressure fluctuation generated between the pressure receiving chamber 64 and the equilibrium chamber 66, 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 the present embodiment, the movable rubber film 74 is superimposed on the lower partitioning fitting 42 from the pressure receiving chamber 64 side, and when a positive pressure is exerted on the pressure receiving chamber 64 due to the input of the vibration isolation target vibration, The movable rubber film 74 is pressed against the lower partition fitting 42 so that the lower communication window 58 is held in a shut-off state. As a result, the hydraulic pressure in the pressure receiving chamber 64 is prevented from escaping to the equilibrium chamber 66 through the short-circuit channel 73, and the intended high attenuation effect can be obtained effectively.

  Further, at the time of normal vibration input, the movable rubber film 74 is pressed against the lower partition fitting 42 to such an extent that the contact state between the movable rubber film 74 and the lower partition fitting 42 is not released. Therefore, at the time of normal vibration input, the hydraulic pressure in the pressure receiving chamber 64 is prevented from being released to the equilibrium chamber 66 through the short-circuit channel 73, and the vibration isolation effect based on the fluid flow through the orifice passage 72 is effectively exhibited. I can do it.

  Furthermore, in the present embodiment, a leaf spring 78 is fixed to the movable rubber film 74, and the leaf spring 78 includes a spoke-like spring portion 82 that extends radially. As a result, the free length of the single rubber portion that is relatively easily deformed in the movable rubber film 74 is suppressed to be small, and the hydraulic pressure absorbing action due to the elastic deformation of the movable rubber film 74 can be suppressed. Therefore, the pressure fluctuation in the pressure receiving chamber 64 can be ensured and the intended vibration isolation effect can be obtained.

  Further, when vibration in the middle to high frequency region such as idling vibration or traveling booming noise is input with the engine mount 10 attached, the orifice passage 72 is substantially closed due to anti-resonant action. The region of the movable rubber film 74 that is out of the fixed portion of the leaf spring 78 is slightly deformed due to the difference in relative pressure fluctuation between the pressure receiving chamber 64 and the equilibrium chamber 66, and the hydraulic pressure in the pressure receiving chamber 64. Is absorbed by being released to the equilibrium chamber 66. Thereby, based on the fluid pressure absorbing action, an effective vibration-proofing effect (low dynamic spring effect) is exhibited with respect to vibrations in the medium frequency range such as idling vibrations and traveling booming sounds.

  Further, if a shocking heavy load is input to the engine mount 10 due to overcoming a step during driving of the automobile, an excessive negative pressure may be generated in the pressure receiving chamber 64. When the hydraulic pressure in the pressure receiving chamber 64 is significantly reduced in this way, the movable rubber film 74 is sucked toward the pressure receiving chamber 64 due to the relative pressure difference between the pressure receiving chamber 64 and the equilibrium chamber 66. By the action of the suction force, the movable rubber film 74 is elastically deformed and pulled toward the pressure receiving chamber 64, so that the outer peripheral edge of the movable rubber film 74 receives pressure from the lower wall portion of the housing space 62 in the partition member 38. The lower communication window 58 is brought into a communication state by being separated from the chamber 64 side.

  As described above, the pressure receiving chamber 64 and the equilibrium chamber 66 are communicated with each other through the upper communication window 48, the accommodation space 62, and the lower communication window 58 (in short, the short-circuit channel 73). The fluid is caused to flow from the equilibrium chamber 66 to the pressure receiving chamber 64 through the short-circuit channel 73 configured to include As described above, by causing the fluid to flow through the short-circuit channel 73 having a smaller flow resistance than the orifice passage 72, the excessive negative pressure in the pressure receiving chamber 64 is eliminated or reduced as quickly as possible. ing.

  Accordingly, in the engine mount 10 according to the present embodiment, the central portion in the radial direction of the movable rubber film 74 is held in contact with the partition member 38, and the outer peripheral portion is the divided rim-shaped portion of the leaf spring 78. 84, and a portion formed between the circumferential direction of the divided rim-shaped portion 84 and formed of a rubber elastic body alone. Thereby, the opening area of the lower communication window 58 (substantial cross-sectional area of the short-circuit channel 73) can be changed according to the degree of negative pressure generated in the pressure receiving chamber 64.

  Specifically, when a negative pressure is applied to the pressure receiving chamber 64 to the extent that bubbles are generated due to cavitation, the region outside the holding portion to which the divided rim-like portion 84 is fixed resists the holding force. Thus, the holding portion to which the divided rim-shaped portion 84 is fixed is held in the initial state by the holding force. A relatively small holding force based on the elastic force of the rubber elastic body is applied to the single rubber portion which is covered and removed from the holding portion which is the fixing portion of the divided rim-like portion 84, while the leaf spring 78 has a relatively small holding force. This is because a large holding force is applied to the holding portion to which the divided rim-shaped portion 84, which is a part, is fixed due to the elasticity of the leaf spring 78 as compared with the rubber single-piece portion.

  In short, when a negative pressure is generated in the pressure receiving chamber 64 so as to generate an abnormal noise due to cavitation, first, as shown in FIG. A relatively narrow region located between the circumferential directions of the portions 84 is partially separated from the partition member 38, and the lower communication window 58 is opened with a relatively small opening area. The sealed fluid flows from the equilibrium chamber 66 into the pressure receiving chamber 64 through the lower communication window 58 partially communicated at a plurality of locations on the periphery of the movable rubber film 74, thereby effectively reducing the negative pressure in the pressure receiving chamber 64. Can be reduced or eliminated.

  When the negative pressure generated in the pressure receiving chamber 64 is larger, a larger suction force based on the negative pressure is applied to the movable rubber film 74. When such a large suction force is exerted on the movable rubber film 74, as shown in FIG. 6, the single rubber portion that has removed the fixed portion of the divided rim-shaped portion 84 at the outer peripheral portion of the movable rubber film 74. The elastic member is further elastically deformed and separated from the partition member 38 by a larger distance.

  Further, since the large suction force as described above is applied to the movable rubber film 74, elastic deformation against the elastic force of the leaf spring 78 also occurs at the fixed portion of the leaf spring 78 in the movable rubber film 74. Squeezed. That is, as shown in FIG. 6, the portion of the movable rubber film 74 to which the leaf spring 78 is fixed is elastically deformed, and the divided rim-shaped portion 84 is fixed to the outer peripheral portion of the movable rubber film 74. The holding portion is separated from the partition member 38.

  In the present embodiment, in the leaf spring 78, a spoke-like spring portion 82 extending radially from the central restraint portion 80 and a divided rim-like portion 84 provided integrally at the outer peripheral side tip of the spoke-like spring portion 82 are: It is thin and narrow. Thereby, in the spoke-like spring portion 82 and the split rim-like portion 84, the leaf spring 78 is relatively easily elastically deformed.

  In this manner, the movable rubber film 74 is separated from the partition member 38 over the entire circumference, so that a larger opening area of the lower communication window 58 is secured. Therefore, the amount of fluid flowing from the equilibrium chamber 66 to the pressure receiving chamber 64 through the short-circuit channel 73 including the lower communication window 58 can be increased, and the negative pressure in the pressure receiving chamber 64 can be more effectively eliminated. .

  As described above, in the engine mount 10 according to the present embodiment, the opening area of the lower communication window 58 can be changed according to the magnitude of the negative pressure in the pressure receiving chamber 64. Therefore, the cavitation prevention effect exhibited by the fluid flow through the short-circuit channel 73 can be effectively obtained according to the magnitude of the generated negative pressure.

  As is clear from the above description, in the engine mount 10 according to the present embodiment, when the positive pressure is applied to the pressure receiving chamber 64, the lower communication window 58 is held in a shut-off state, and the pressure receiving chamber 64 A communication / blocking control means that allows the lower communication window 58 to communicate with each other when a large negative pressure is exerted on the surface is realized using the elasticity of the movable rubber film 74. In addition, a negative pressure is applied (generated) to the pressure receiving chamber 64 when the engine mount 10 is mounted on an automobile so that the internal pressure of the pressure receiving chamber 64 filled with the incompressible fluid is lower than that in the stationary state. Say you will be.

  Further, in the engine mount 10 according to the present embodiment, as described above, the opening area of the lower communication window 58 is adjusted according to the magnitude of the negative pressure acting on the pressure receiving chamber 64, and the lower communication window The fluid flow through the short-circuit channel 73 is also restricted during the communication of 58. Thereby, even under the open state of the lower communication window 58, the fluid flow through the orifice passage 72 is generated, and the vibration-damping effect due to high attenuation can be exhibited.

  In addition, under the open state of the lower communication window 58, the wall spring rigidity of the pressure receiving chamber 64 is lowered, and the tuning frequency of the orifice passage 72 is shifted to the lower frequency side. Therefore, in the engine mount 10 according to the present embodiment, an effective anti-vibration effect can be obtained against vibrations in a wider frequency range including a frequency range lower than the original tuning frequency.

  Next, FIG. 7 shows an engine mount 88 for an automobile as a second embodiment of the fluid filled type vibration damping device according to the present invention. In the following description, members and portions that are substantially the same as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  That is, the engine mount 88 includes a partition member 90. The partition member 90 is a highly rigid member formed of iron, an aluminum alloy, or the like, and has a substantially disk shape with a thick wall and a large diameter. The partition member 90 further includes a partition member main body 92 and a lid fitting 94.

  The partition member main body 92 has a substantially disk shape as a whole, and has a circular accommodation recess 96 that opens upward in the center. Further, a circumferential groove 98 is formed in the outer peripheral portion of the partition member main body 92 so as to open to the upper end surface and extend in the circumferential direction with a predetermined length of a little less than one round.

  The lid fitting 94 is a high-rigidity member having a thin and substantially disk shape having substantially the same outer diameter as that of the partition member main body 92, and is disposed on the same central axis as the partition member main body 92, and has an upper end surface thereof. The partition member 90 is configured by being overlaid.

  In the present embodiment, a stepped portion 28 formed on the lower end of the main rubber elastic body 16 is fitted to the inner peripheral side of the second mounting bracket 14 in a state where the partition member main body 92 and the lid fitting 94 are overlapped. The partition member main body 92 and the cover fitting 94 are combined and fixed in the axial direction by being sandwiched between the axial directions of the fixing fitting 34 fixed to the outer peripheral surface of the diaphragm 30.

  As in the first embodiment, the partition member 90 is inserted into the second mounting bracket 14 and is subjected to diameter reduction processing on the second mounting bracket 14, thereby It is fixedly supported with its outer peripheral surface being in close contact with the second mounting bracket 14.

  In addition, the opening of the circumferential groove 98 formed in the outer peripheral edge of the partition member main body 92 is covered with a cover metal 94 when the partition member 90 is attached to the second mounting bracket 14. Thereby, a tunnel-like flow path extending in the circumferential direction on the outer peripheral portion of the partition member 90 is formed. Further, an upper connection path 68 is formed in the lid fitting 94 at a position corresponding to the circumferential end of the circumferential groove 98, and a lower connection path 70 is formed in the partition member main body 92. Through these upper and lower connection paths 68 and 70, the circumferential end of the circumferential groove 98 is communicated with the pressure receiving chamber 64 and the equilibrium chamber 66, and the orifice passage 100 communicating the pressure receiving chamber 64 and the equilibrium chamber 66 with each other is surrounded by the circumference. It is formed using the groove 98.

  In addition, an accommodation space 102 is formed in the central portion of the partition member 90. The accommodation space 102 is formed by covering the opening of the accommodation recess 96 formed in the partition member main body 92 with a lid fitting 94.

  Further, an upper communication window 104 is formed through the intermediate portion in the radial direction of the lid fitting 94 that constitutes the upper wall surface of the accommodation space 102. As shown in FIG. 8, the upper communication window 104 has a fan shape with a central angle of about 90 ° when viewed in the axial direction, and four upper communication windows 104 are formed at equal intervals in the circumferential direction. Has been. The accommodation space 102 communicates with the pressure receiving chamber 64 through the upper communication window 104.

  Furthermore, a lower communication window 106 as a communication path is formed through the intermediate portion in the radial direction of the partition member main body 92 constituting the lower wall surface of the accommodation space 102. The lower communication window 106 has a shape substantially corresponding to the upper communication window 104 when viewed in the axial direction, and four lower communication windows 106 are formed at positions corresponding to the upper communication window 104 on the circumference. The accommodation space 102 is communicated with the equilibrium chamber 66 through the lower communication window 106.

  As described above, the accommodation space 102 communicates with the pressure receiving chamber 64 through the upper communication window 104 and also communicates with the equilibrium chamber 66 through the lower communication window 106. As a result, the short-circuit channel 108 that communicates the pressure receiving chamber 64 and the equilibrium chamber 66 with each other includes the lower communication window 106. As is clear from the above description, the short-circuit channel 108 is formed to communicate the pressure receiving chamber 64 and the equilibrium chamber 66 at a position different from the orifice passage 100.

  In this case, a movable rubber film 110 as a closed rubber elastic plate is disposed in the accommodation space 102. The movable rubber film 110 is formed of a rubber elastic body having a substantially disc shape. The outer diameter of the movable rubber film 110 is smaller than the inner diameter of the accommodation space 102 and the outer peripheral edge of the lower communication window 106 is outside. It is the size which extends to. The movable rubber film 110 accommodated in the accommodation space 102 is subjected to the liquid pressure of the pressure receiving chamber 64 on one surface thereof, and the liquid in the equilibrium chamber 66 on the other surface. Pressure is applied.

  Further, in the present embodiment, the outer peripheral portion of the movable rubber film 110 is restrained by the sandwiching protrusion 112 as a restraining means. As shown in FIGS. 7 and 8, the sandwiching protrusion 112 is integrally formed so as to protrude downward in the central portion in the radial direction of the lid fitting 94, and is protruded from the outer peripheral portion of the accommodation space 102. ing. As shown in FIG. 7, the outer peripheral portion of the movable rubber film 110 is held and restrained between the front end surface of the holding protrusion 112 and the lower wall portion of the housing space 102. In the present embodiment, as shown by broken lines in FIG. 8, the sandwiching protrusions 112 are formed at four positions on the circumference, and each sandwiching protrusion 112 has a predetermined length in the circumferential direction. It extends.

  When the movable rubber film 110 is disposed in the accommodation space 102 with the outer peripheral portion being constrained in this way, the lower communication window 106 that allows the accommodation space 102 to communicate with the equilibrium chamber 66 is the movable rubber film 110. The short-circuit channel 108 is blocked by the movable rubber film 110 by being blocked.

  In a state where the engine mount 88 having such a structure is mounted on a vehicle, when a low-frequency large-amplitude vibration corresponding to an engine shake is input, the resonance action or the like of the incompressible fluid that flows through the orifice passage 100 is generated. Based on the anti-vibration effect. In addition, when medium to high frequency small amplitude vibration such as idling vibration or traveling booming sound is input, the movable rubber film 110 is elastically deformed minutely based on the pressure difference between the pressure receiving chamber 64 and the equilibrium chamber 66, thereby causing the liquid. The pressure absorbing action is effectively exhibited, and the vibration isolation effect due to the low dynamic spring effect can be obtained.

  When a positive pressure is applied to the pressure receiving chamber 64, the movable rubber film 110 is pressed against the lower wall portion of the accommodation space 102, and the lower communication window 106 is held closed. Thereby, the hydraulic pressure in the pressure receiving chamber 64 can be secured, and the fluid flow through the orifice passage 100 is effectively generated. Accordingly, it is possible to effectively obtain the intended vibration-proofing effect.

  Here, when an excessively large negative pressure is applied to the pressure receiving chamber 64 due to a shocking large load being input to the engine mount 88, for example, when the automobile gets over a level difference, the movable rubber film 110 is separated from the pressure receiving chamber 64. The pressure is sucked toward the pressure receiving chamber 64 by the relative pressure difference in the equilibrium chamber 66. As a result, the region of the outer peripheral edge of the movable rubber film 110 that is out of the holding portion by the sandwiching protrusion 112 is elastically deformed by the negative pressure of the pressure receiving chamber 64. And in the area | region which removed this holding | maintenance part, the outer-periphery edge part of the movable rubber film 110 is separated from the partition member 90, the interruption | blocking state of the short circuit flow path 108 is cancelled | released, and the pressure receiving chamber 64 and the equilibrium chamber 66 are short-circuited. They are communicated with each other through a path 108.

  In this manner, the pressure receiving chamber 64 and the equilibrium chamber 66 are communicated with each other through the short-circuit channel 108, and the sealed fluid flows between the two chambers 64, 66, thereby reducing the negative pressure in the pressure receiving chamber 64. Cavitation bubbles generated by being quickly eliminated and an excessive negative pressure applied to the pressure receiving chamber 64 can be prevented, and abnormal noise and vibration generated when the bubbles disappear can be effectively prevented.

  In addition, since the outer peripheral portion of the movable rubber film 110 is constrained by the sandwiching protrusions 112 at a plurality of locations on the circumference, the short-circuit channel 108 is formed when an impactful large load is generated so that bubbles due to cavitation are generated. When a load that does not generate bubbles due to cavitation is input while being communicated, the short-circuit channel 108 is held in a shut-off state, and a high damping effect due to fluid flow through the orifice passage 100 or a movable rubber Based on the low dynamic spring effect due to the minute deformation of the film 110, the intended anti-vibration effect is effectively exhibited.

  In addition, it is clear from the graph of the measurement result shown in FIG. 9 that the effect of eliminating the negative pressure in the pressure receiving chamber is advantageously exhibited in the fluid filled type vibration damping device according to the present invention.

  That is, in the measurement result of Comparative Example 1 that does not have a structure for releasing the hydraulic pressure in the pressure receiving chamber, a significantly large negative pressure may be generated in the pressure receiving chamber, as indicated by the broken line in FIG. Then, in a significantly negative pressure state, in other words, in a vacuum state where the internal pressure of the pressure receiving chamber is 0, abnormal noise and vibration are generated by bubbles generated from the liquid. As described above, in Comparative Example 1, the generation of abnormal noise and vibration due to cavitation may be a problem.

  Therefore, in the measurement result of the example using the fluid filled type vibration isolator according to the present invention, as shown by the solid line in FIG. 9, the negative pressure in the pressure receiving chamber is more effectively eliminated, The internal pressure of the pressure receiving chamber is zero, i.e., no vacuum is reached. Therefore, in the embodiment, generation of bubbles from the liquid due to a decrease in the internal pressure of the pressure receiving chamber is suppressed, and abnormal noise due to cavitation is reduced or avoided. As described above, it is clear from the measurement results that the fluid filled vibration isolator according to the present invention can effectively prevent the generation of abnormal noise and vibration due to cavitation.

  Further, in the fluid filled type vibration damping device having the structure according to the present invention, it is shown in FIGS. 10 and 11 that the vibration damping effect due to the fluid action of the fluid flowing through the orifice passage is effectively exhibited in a wider frequency range. It is clear from the actual measurement results.

  That is, the measurement result of the embodiment using the fluid-filled vibration isolator having the structure according to the present invention shown by the solid line in FIG. 10 is the conventional structure that does not have the hydraulic pressure relief structure shown by the broken line in FIG. Compared with the measurement result of Comparative Example 1 using the above-described fluid-filled vibration isolator, an effective high attenuation effect is exhibited in a wider frequency range. As shown in FIG. 10, the maximum value of the damping force in the measurement result of the example is smaller than the maximum value of the damping force in the measurement result of Comparative Example 1. In the example, Sufficient damping force for obtaining the desired vibration-proofing effect can be obtained over a wider frequency range, and the reduction of the damping force is not substantially a problem.

  Further, according to FIG. 11, in the measurement result of the embodiment according to the present invention indicated by a solid line in the drawing, a mechanism for adjusting the opening area of the communication path indicated by a dashed line in the drawing (in short, a blocking rubber) Compared with the measurement result of Comparative Example 1 that employs a fluid-filled vibration isolator having a structure that does not have a restraining means for restraining the outer peripheral edge of the elastic plate, a high damping effect is exhibited in a wider frequency range. Can be confirmed. As described above, in the fluid filled type vibration damping device according to the present invention, it is also possible from the measurement result that the vibration damping effect exhibited by the fluid flow through the orifice passage can be effectively obtained over a wider frequency range. it is obvious.

  Although several embodiments of the present invention have been described above, these are merely examples, and the present invention is not construed as being limited to specific descriptions in such embodiments.

  For example, the movable rubber film 74 shown in the first and second embodiments exemplifies the closed rubber elastic plate according to the present invention, and the specific structure of the closed rubber elastic plate is The present invention is not limited to the specific structures shown in the first and second embodiments.

  Specifically, for example, the movable rubber film 114 shown in FIG. 12 can be employed as the closing rubber elastic plate. That is, the movable rubber film 114 is formed of a rubber elastic body having a substantially hexagonal shape when viewed in the axial direction (a direction orthogonal to the paper surface in FIG. 12), and includes a leaf spring 116.

  The plate spring 116 is formed of metal or synthetic resin as in the first and second embodiments, and has a plate shape integrally including the central restraint portion 80, the spoke-like spring portion 82, and the divided rim-like portion 118. It is said that. The split rim-shaped portion 118 has a linear shape orthogonal to the spoke-shaped spring portion 82, extends along the outer shape of the movable rubber film 114, and is integrally formed on the outer peripheral side end portion of the spoke-shaped spring portion 82. .

  The movable spring film 114 is formed by fixing the leaf spring 116 having the above structure to a rubber elastic body having a substantially hexagonal shape when viewed in the axial direction. Also by adopting the movable rubber film 114 having such a structure as a closed rubber elastic plate, it is possible to achieve the effect of eliminating abnormal noise due to the intended cavitation and the expression of the orifice effect in a wide frequency range. .

  It goes without saying that the closing rubber elastic plate may be a polygon other than a hexagon. In addition, the closing rubber elastic plate can use a rubber elastic body previously formed into a polygonal shape such as a hexagon, or is a rubber elastic body previously formed into a circular shape, such as a shrinkage after the forming. As a result, it is possible to use a shape having a polygonal shape or a linear string-like outer shape. In short, the shape of the closing rubber elastic plate is not particularly limited.

  Further, as the closing rubber elastic plate, for example, a plate spring 122 constituted by a central restraining portion 80 and a spoke-like spring portion 82, as in the movable rubber film 120 shown in FIG. It is also possible to adopt a structure embedded and fixed in the body. As described above, by adopting the leaf spring 122 having a structure in which the divided rim-like portion 84 extending in the substantially circumferential direction is omitted, the free area of the region where the fixed portion of the leaf spring 122 is removed at the outer peripheral edge portion of the movable rubber film 120. The length can be increased, and elastic deformation at the outer peripheral edge can be easily generated. Accordingly, it is possible to obtain a large opening area of the lower communication window 58 in a region where the fixed portion of the leaf spring 122 is removed.

  In the case where the leaf spring 78 having a structure including the divided rim-like portion 84 is provided, like the movable rubber film 74 shown in the first and second embodiments, the circumferential direction of the divided rim-like portion 84 is increased. By appropriately setting the length, the opening area of the lower communication window 58 before the deformation of the leaf spring 78 and the opening area of the lower communication window 58 due to the deformation of the leaf spring 78 can be adjusted.

  Further, for example, like the movable rubber film 124 shown in FIG. 14, the leaf spring 126 has spoke-like spring portions 82 extending toward both sides in one direction perpendicular to the axis, and each spoke-like spring portion 82. A structure in which the divided rim-like portions 84 are integrally formed with respect to the tip portion on the outer peripheral side of the outer peripheral side can also be adopted as the closing rubber elastic plate. Thus, the number, shape, etc. of the spoke-like spring parts and the split rim-like parts are not particularly limited, and are appropriately set according to the required vibration isolation characteristics.

  Further, in the movable rubber film 74 shown in the first and second embodiments, the divided rim-like portion 84 provided on the outer peripheral edge of the leaf spring 78 is embedded in the rubber elastic body throughout. Although it has a structure, for example, like the movable rubber film 130 shown in FIG. 15, the split rim-like portion 132 of the leaf spring 131 is blocked from the outer peripheral surface of the movable rubber film 130 exposed. You may employ | adopt as a rubber elastic board. For example, the divided rim-shaped portion may be partially exposed on the outer peripheral surface in the circumferential direction. Further, part or all of the divided rim-like portion in the closing rubber elastic plate may be exposed on both sides or one side in the thickness direction.

  In the closed rubber elastic plate, the plate spring does not necessarily have to be fixed in a state of being embedded in the rubber elastic body. For example, a plate spring or the like is provided on one surface of the rubber elastic body having a disk shape. The closed rubber elastic plate provided with the restraining means can also be realized by overlapping and fixing.

  The movable rubber film 74 shown in the first and second embodiments has a structure in which a leaf spring 78 formed of metal or hard synthetic resin is fixed as a restraining means. Even in the closed rubber elastic plate formed of only the elastic body, the restraining means can be realized by fixing the reinforcing member of the rubber elastic body formed separately or changing the thickness or shape.

  Specifically, for example, as in the movable rubber film 134 shown in FIGS. 16 and 17, a reinforcing member 138 as a reinforcing member formed of a rubber elastic body as a restraining means fixed to the rubber film main body 136. Can also be configured. The rubber film main body 136 is a rubber elastic body having a substantially disk shape, and a contact protrusion 76 protruding downward is integrally formed on the outer peripheral edge portion, and a circular through hole is formed in the center portion. 140 is formed.

  Further, as shown in FIG. 17, the reinforcing body 138 is formed of a rubber elastic body, and has a central annular portion 142, a spoke-like spring portion 144, and a divided rim-like portion 146. It has the same shape as the leaf spring 78 shown in the first and second embodiments. The central annular portion 142 has a substantially circular shape with a small diameter, and constitutes a central portion of the reinforcing body 138. The central annular portion 142 is integrally formed with a longitudinal spoke-shaped spring portion 144 that extends radially toward the outer peripheral side. In addition, a split rim-shaped portion 146 extending in a circumferential direction with a predetermined length is integrally formed at the outer peripheral end portion of each spoke-shaped spring portion 144. The reinforcing body 138 has a spring constant larger than that of the rubber film main body 136.

  The movable rubber film 134 formed by superposing and fixing the reinforcing body 138 having such a structure on one surface of the rubber film main body 136 is formed of a rubber elastic body and has a relatively large spring constant. The restraining means is realized by the strengthened body 138. Thus, it is not always necessary to employ a separate member such as a leaf spring formed of metal or hard synthetic resin as the restraining means, and the restraining means can be realized by a rubber elastic body.

  Note that the reinforcing body 138 can be integrally formed with the rubber film main body 136. That is, the restraining means can also be realized by partially increasing the thickness of the movable rubber film 134 and increasing the spring constant in the thick portion. According to this, the number of parts is reduced, and the work of fixing the reinforcing body 138 and the rubber film main body 136 becomes unnecessary. Further, a separate or integral reinforcing body 138 may be provided on both surfaces of the rubber film main body 136.

  In the second embodiment, the structure in which the outer peripheral portion of the movable rubber film 110 is constrained by the partition member 90 is shown. However, the outer peripheral portion of such a closing rubber elastic plate is constrained by the partition member. In the constructed structure, the restraining means is not limited to the structure shown in the second embodiment.

  For example, as in the movable rubber film 148 shown in FIG. 18, a structure in which a restraining protrusion 150 as a restraining means is integrally formed on the outer peripheral portion of the movable rubber film 148 can be adopted. That is, on the outer peripheral portion of the movable rubber film 148 formed of a disk-shaped rubber elastic body, block-shaped restricting protrusions 150 protruding upward are formed at four locations on the periphery.

  The movable rubber film 148 is accommodated in the accommodating space 102 of the partition member 152. The partition member 152 includes a partition member main body 92 and a lid fitting 154. The lid fitting 154 has a thin and large-diameter substantially disk shape, and the upper communication window 104 is formed in the radially intermediate portion, and the upper connection path 68 is formed in the outer peripheral portion. Furthermore, the support protrusion 156 is formed by causing the center portion in the radial direction of the lid fitting 154 to protrude downward by pressing or the like. The partition member main body 92 and the lid fitting 154 are overlapped with each other in the axial direction, and a housing space 102 is formed between the partition member main body 92 and the lid fitting 154 in the central portion in the radial direction. .

  Then, under the arrangement of the movable rubber film 148 shown in FIG. 19 in the accommodation cavity 102, the upper end surface of the restraining projection 150 is brought into contact with the upper wall surface of the accommodation cavity 102, and the movable rubber film The lower surface of the outer peripheral portion of the membrane 148 is brought into contact with the lower wall surface of the accommodation space 102. As a result, the portion of the outer peripheral portion of the movable rubber film 148 where the restraining protrusion 150 is formed is sandwiched between the partition member main body 92 and the lid fitting 154 and restrained by the partition member 90. As described above, also in the structure shown in FIGS. 18 and 19, a restraining means for restraining the outer peripheral portion of the movable rubber film 148 can be realized. 18 and 19, the central portion of the movable rubber film 148 is sandwiched and fixed between the support protrusion 156 provided on the lid fitting 154 and the partition member main body 92. It has become.

  Furthermore, as shown in FIGS. 20 and 21, it is possible to adopt a structure in which the restraining protrusions 150 formed on the outer peripheral portion of the movable rubber film 158 are connected by radially extending spoke-like spring parts 160. . In the movable rubber film 158 according to this aspect, since the central portion in the radial direction of the movable rubber film 158 protrudes at substantially the same height as the restraining protrusion 150, the partition where the movable rubber film 158 is disposed. In the member 162, the central portion in the radial direction of the lid fitting 164 constituting the member 162 has a flat shape with no irregularities (such as the support protrusion 156). Further, in this aspect, the spoke-like spring part 160 is formed with the substantially same protruding height as that of the restraining projection part 150, and the entire part of the movable rubber film 158 where the spoke-like spring part 160 is formed is the partition member 162. Is restrained by.

  Furthermore, as shown in FIGS. 22 and 23, in the movable rubber film 166 having a substantially disc shape, a plurality of portions on the circumference are extended to the outer peripheral side, and the restraining protrusion 150 is provided on the extended portion. It is also possible to adopt a structure in which is integrally formed. According to such a structure, the outer peripheral edge portion of the movable rubber film 166 between the circumferential directions of the restraining projection portion 150 is positioned closer to the inner circumference side than the restraining projection portion 150. The elastic deformation of the movable rubber film 166 in the region outside the formation portion can be caused more easily. In this embodiment, a central protrusion 168 having a circular block shape is integrally formed at the central portion in the radial direction of the movable rubber film 166 and protrudes upward.

  Further, as the closing rubber elastic plate, for example, a structure provided with a central film portion 172 in the central portion, such as the movable rubber film 170 shown in FIGS. More specifically, in the movable rubber film 170 having a plurality of restraining protrusions 150 that are circumferentially separated from each other at the outer peripheral edge, a cylindrical central cylindrical portion 174 is integrally formed at the radially central portion and protrudes upward. . Further, a thin central film portion 172 extending in the direction perpendicular to the axial direction is formed at the axial central portion on the inner peripheral side of the central cylindrical portion 174, and the central hole of the central cylindrical portion 174 is formed by the central membrane portion 172. It is blocked.

  In addition, the movable rubber film 170 having the above-described structure is accommodated in the accommodating space 102 of the partition member 176. The partition member 176 has a thick and large-diameter substantially disk shape, and includes a partition member main body 178 and a lid fitting 180. The partition member main body 178 and the lid fitting 180 have a structure similar to the partition member main body 92 and the lid fitting 94 shown in the second embodiment. Further, an upper communication window 182 extending through a predetermined length in the circumferential direction is formed through the intermediate portion in the radial direction of the lid fitting 180, and a predetermined amount in the circumferential direction is provided in the radial intermediate portion of the partition member body 178. A lower communication window 184 is formed as a communication path extending in the length of. Further, a circular upper through hole 186 is formed through the central portion of the lid metal member 180 in the radial direction, and a lower through hole having a shape corresponding to the upper through hole 186 is formed in the central portion of the partition member body 178 in the radial direction. A hole 188 is formed through.

  The movable rubber film 170 is disposed in the accommodation space 102 formed between the overlapping surfaces of the partition member main body 178 and the lid fitting 180. The central cylindrical portion 174 of the movable rubber film 170 is positioned between the communication windows 182 and 184 and the through holes 186 and 188 in the radial direction, and is sandwiched between the partition member main body 178 and the lid fitting 180. In addition, the restraining protrusion 150 is positioned on the outer peripheral side of the communication windows 182 and 184 and is sandwiched between the partition member main body 178 and the lid fitting 180. As a result, the intermediate portion in the radial direction of the movable rubber film 170 is fixed to the partition member 176, and the outer peripheral edge portion is partially restrained by the partition member 176.

  In the movable rubber film 170, the pressure in the pressure receiving chamber 64 is applied to one surface of the radially intermediate portion through the upper communication window 182 and to the other surface through the lower communication window 184. The pressure of the equilibrium chamber 66 is exerted. Further, in the movable rubber film 170, the pressure of the pressure receiving chamber 64 is applied to one surface of the central film portion 172 through the upper through hole 186, and the other surface is transmitted through the lower through hole 188. The pressure of the equilibrium chamber 66 is exerted.

  Then, in the state where the engine mount provided with the movable rubber film 170 having such a structure is mounted on the automobile, a shocking heavy load due to stepping over a step or the like is input, and an excessive negative pressure is generated in the pressure receiving chamber 64. When tightened, the region outside the portion where the restraining projection 150 is formed in the outer peripheral portion of the movable rubber film 170 is elastically deformed. As a result, the sealed fluid is caused to flow through the short-circuit channel 108 communicated with each other, and generation of abnormal noise and vibration due to cavitation is prevented.

  Furthermore, when high-frequency small-amplitude vibration corresponding to idling vibration or running-over noise is input, the central membrane portion 172 is slightly deformed up and down with the outer peripheral edge portion being constrained. Thereby, based on the hydraulic pressure absorption action by the minute elastic deformation of the central membrane part 172, the vibration isolation effect by the low dynamic spring effect is effectively exhibited.

  It is also possible to adopt a structure in which the central cylindrical portion 174 and the restraining projection portion 150 are connected by a spoke-like spring portion 192 that extends radially as in the movable rubber film 190 shown in FIGS. Thereby, the rigidity of the movable rubber film 190 in the outer peripheral portion of the movable rubber film 190 can be adjusted.

  In the first embodiment, the central portion in the radial direction of the movable rubber film 74 is fixed to the partition member 38 by being sandwiched between the lower wall surface of the accommodation space 62 and the support protrusion 50. However, in the case of adopting a structure in which the central portion in the radial direction of the movable rubber film 74 is fixed to the partition member 38, the fixing means is not particularly limited.

  That is, the central portion in the radial direction of the closing rubber elastic plate may be fixed to the partition member by screwing. Specifically, for example, a structure such as a partition member 194 shown in FIG. 28 can be adopted. More specifically, the partition member 194 includes an upper partition fitting 195 and a lower partition fitting 196. The upper partition fitting 195 has a structure similar to the upper partition fitting 40 in the first embodiment, and has a flat shape in which the central portion in the radial direction does not have the support protrusion 50. On the other hand, the lower partition fitting 196 has a structure similar to the lower partition fitting 42 in the first embodiment, and a bolt hole 197 is formed through the central portion in the radial direction. The bolt hole 197 is a small-diameter circular hole extending in the axial direction on the bottom wall portion of the accommodation space 62, and a thread is engraved on the inner peripheral surface.

  A movable rubber film 74 is disposed in the accommodation space 62 of the partition member 194. Then, the fixing bolt 198 is inserted into the fitting hole 86 formed in the leaf spring 78 of the movable rubber film 74, and the fixing bolt 198 is screwed into the bolt hole 197 formed in the lower partition metal fitting 196. As described above, the central portion in the radial direction of the movable rubber film 74 can be fixed to the lower partition metal fitting 196.

  Further, for example, in a partition member made of hard synthetic resin, the central portion of the closing rubber elastic plate can be fixed to the partition member by welding. More specifically, as shown in FIG. 29, the partition member 200 has a generally thick plate shape as a whole, and a receiving recess 202 that opens to the upper surface is provided at a central portion in the radial direction. Is formed, and a circular recess 204 is formed in the lower surface. Further, a circumferential groove 206 that opens to the outer peripheral surface is formed in a spiral shape with a length of a little less than two in the circumferential direction on the outer peripheral edge of the partition member 200. The partition member 200 is attached to the inner peripheral side of the second mounting bracket 14 as in the first embodiment, so that the housing recess 202 constitutes a part of the pressure receiving chamber 64 and the circular recess. While 204 forms a part of the equilibration chamber 66, an orifice passage 72 is formed by the circumferential groove 206.

  Further, a communication passage 208 penetrating in the axial direction is formed in the central portion of the partition member 200. The communication path 208 has a substantially sector shape with a central angle of about 120 ° when viewed in the axial direction, and three communication paths 208 are formed at regular intervals on the circumference. Note that, when the partition member 200 is assembled to the second mounting member 14, the pressure receiving chambers 64 and the equilibrium chamber 66 formed on both sides of the partition member 200 are communicated with each other through the communication path 208.

  Further, a welding protrusion 210 is integrally formed at the radial center of the accommodation recess 202 in the partition member 200. The welding protrusion 210 has a small-diameter rod shape, and protrudes upward from the bottom wall portion of the housing recess 202.

  Here, a movable rubber film 74 is disposed in the accommodation recess 202. In other words, the welding projection 210 is inserted into the fitting hole 86 of the leaf spring 78 constituting the movable rubber film 74. Thereafter, the tip portion of the welding projection 210 is melted by ultrasonic projection, heating, or the like, processed to have a large diameter, and fixed to the central portion of the leaf spring 78 exposed to the outside. . Thereby, the movable rubber film 74 is disposed in the accommodation recess 202 in a state where the central portion is fixed to the partition member 200. Thus, it is also possible to fix the central part of the closing rubber elastic plate to the partition member by welding.

  Further, for example, an engaging portion that can be engaged with the closing rubber elastic plate can be provided in the partition member, and the central portion of the closing rubber elastic plate can be fixed to the partition member by the engaging action of the engaging portion. Specifically, for example, a structure like the partition member 212 shown in FIG. 30 can be adopted. In other words, the partition member 212 includes an upper partition fitting 214 and a lower partition fitting 216. The upper divider 214 has a structure similar to that of the upper divider 40 shown in the first embodiment, and has a circular shape that penetrates the bottom wall portion of the central recess 44 in the radial center portion. An upper communication window 217 is formed.

  On the other hand, the lower partition fitting 216 has a structure similar to that of the lower partition fitting 42 shown in the first embodiment, and has a structure that projects toward the inside of the accommodation space 62 at the radial center portion. A caulking projection 218 as a joint is integrally formed. The caulking protrusion 218 has a small-diameter rod shape, and has a shape substantially corresponding to the fitting hole 86 formed in the leaf spring 78 of the movable rubber film 74.

  When the movable rubber film 74 is disposed in the accommodation space 62, the caulking protrusion 218 is inserted into the fitting hole 86 formed in the leaf spring 78. Thereafter, an external force is applied to the caulking projection 218 in the axial direction, and the tip portion of the caulking projection 218 that is projected through the leaf spring 78 is deformed so as to have a larger diameter than the inner diameter of the fitting hole 86. As a result, the central portion of the leaf spring 78 exposed to the outside is held by the caulking protrusion 218, and the central portion of the movable rubber film 74 is fixed to the partition member 212. As described above, the radially central portion of the movable rubber film 74 may be fixed to the partition member 212 by caulking.

  Further, a fixing means can be provided on the side of the closing rubber elastic plate. Specifically, for example, a structure such as the movable rubber film 220 shown in FIG. 31 can be adopted. That is, the movable rubber film 220 is integrally formed with a substantially cylindrical pinching holding portion 224 that extends in the axial direction at the central portion of the leaf spring 222. The upper end surface of the pinching holding portion 224 is pressed against the upper wall surface of the accommodation space 62 and the lower end surface of the movable rubber film 220 is pressed against the lower wall surface of the accommodation space 62, whereby the movable rubber film The central part of 220 may be fixed to the partition member 38.

  Furthermore, for example, the fixing means provided on the closing rubber elastic plate side can be formed of a rubber elastic body. That is, in the movable rubber film 226 as the closing rubber elastic plate shown in FIG. 32, the pinched rubber elastic body 228 having a circular block shape is fixed to the upper surface of the central restraining portion 80 of the leaf spring 78 and protrudes upward. Are integrally formed with a rubber elastic body constituting the movable rubber film 226. Then, the upper end surface of the nipping rubber elastic body 228 is pressed against the upper wall surface of the accommodation space 62, and the central lower end surface of the movable rubber film 226 is pressed against the lower wall surface of the accommodation space 62. A central portion of the membrane 226 is supported by the partition member 38. In this aspect, the central portion in the radial direction of the movable rubber film 226 is elastically held to the partition member 38 to some extent.

  It is also possible to fix the central portion of the closing rubber elastic plate to the partition member by providing an engaging portion at the center portion of the closing rubber elastic plate and engaging the engaging portion with the partition member. Specifically, for example, a structure such as a partition member 230 and a movable rubber film 231 shown in FIG. 33 can be adopted. That is, in the partition member 230, the locking hole 234 is formed through the central portion in the radial direction of the lower partition fitting 232 constituting the partition member 230. In the movable rubber film 231, a caulking tube portion 240 that protrudes downward from the radial center portion of the leaf spring 238 is integrally formed.

  Then, after the caulking tube portion 240 is inserted into the locking hole 234 formed through the center portion of the lower partition metal fitting 232, the front end portion of the caulking tube portion 240 is expanded and deformed by applying an external force. As a result, the central portion of the lower partition fitting 232 is sandwiched between the tip of the caulking tube portion 240 and the central portion of the leaf spring 238, and the radial central portion of the movable rubber film 231 is fixed to the partition member 230.

  Further, for example, like a movable rubber film 242 shown in FIG. 34, a locking rubber 244 formed integrally with the central portion in the radial direction of the movable rubber film 242 is replaced with a locking rubber formed at the center of the lower partition metal fitting 232. The fixing to the partition member 230 at the center portion of the movable rubber film 242 can also be realized by inserting the hole 234 into the hole 234 and locking it.

  More specifically, the locking rubber 244 has a substantially rod shape protruding downward in the radial center portion of the movable rubber film 242, and has a base end portion formed with an outer diameter substantially equal to the locking hole 234. A locking portion 248 having a larger diameter than the base end portion 246 is integrally formed below the H.246. Further, the locking portion 248 gradually becomes smaller in diameter as it goes to the distal end side (downward in FIG. 34).

  The locking rubber 244 is inserted into the locking hole 234, the base end portion 246 is inserted into the locking hole 234, and the locking portion 248 protrudes below the partition member 230 through the locking hole 234. I'm damned. Thereby, the step formed between the base end portion 246 and the locking portion 248 of the locking rubber 244 is locked to the partition member 230 so that the central portion of the movable rubber film 242 is fixed to the partition member 230. It has become.

  Further, the shape of the communication path (lower communication window 58) shown in the first and second embodiments is merely an example, and the shapes and sizes of the upper communication window 48 and the lower communication window 58 are as follows. Appropriately set according to the desired vibration-proof characteristics. Specifically, for example, as shown in FIG. 35, a plurality of communication windows 252 having a circular cross section with respect to the portion constituting the upper wall portion and the lower wall portion of the accommodation space 62 in the partition member 250. May be formed through.

  Further, in addition to the communication windows 48 and 58 having a substantially semicircular cross section divided in one radial direction shown in the first and second embodiments, the two divided in two radial directions perpendicular to each other. Communication window having a substantially fan-shaped cross section with a central angle of 90 °, a communication window positioned on the circumference and having a substantially fan-shaped cross section with a central angle of 120 °, and further extending in the circumferential direction in one radial direction A pair of communication windows or the like that are opposed to each other can be adopted.

  Further, the reinforcing member provided on the closing rubber elastic plate is substantially the same shape and size as the leaf spring 78 and the like shown in the first embodiment, and can also be realized by a rigid member. . Thus, in the closed rubber elastic plate 74 having the rigid reinforcing member 78 that does not substantially deform, the outer peripheral portion of the closed rubber elastic plate 74 is in contact with the partition member 38. It is held more stably. Therefore, the vibration isolation effect by the fluid flow through the orifice passage 72 at the time of normal vibration input is effectively exhibited.

  In addition, since the rigid reinforcing member 78 has the radial spoke-like portions 82, the portion that is deformed by the negative pressure of the pressure receiving chamber 64 becomes a rubber whose free length in the circumferential direction becomes smaller toward the inner peripheral side. It is limited to a single part of the elastic body. Therefore, the opening area of the communication passage 73 is adjusted with high accuracy in accordance with the magnitude of the negative pressure acting on the closing rubber elastic plate 74, and an effective cavitation elimination effect and fluid flow through the target orifice passage 72 are achieved. In addition to the anti-vibration effect, the tuning of the orifice passage 72 is automatically adjusted, so that the anti-vibration effect can be effectively exhibited against vibrations in a wider frequency range.

  Even when the reinforcing member is a rigid body, the reinforcing member may have a shape and size different from those of the leaf spring 78 shown in the first embodiment. It can be designed appropriately according to the sound cancellation effect and the like.

  Moreover, in 1st embodiment shown by FIGS. 1-6, the center part of the leaf | plate spring 78 is being fixed with respect to the partition member 38, and the elastic deformation of each spoke-like spring part 82 is accept | permitted equally. However, the fixing position including the fixing position and the fixing structure of the leaf spring 78 with respect to the partition member 38 is not limited. For example, the leaf spring 78 is fixed to the partition member 38 at two points on the pair of rim-shaped portions 84 and 84 that are opposed to each other in the radial direction in the leaf spring 78, or four spoke-like shapes are provided in the leaf spring. The spring portions may be formed at equal intervals in the circumferential direction, and the respective radial tip portions of the pair of spoke-shaped spring portions opposed to each other in the radial direction may be fixed to the partition member. As described above, the leaf spring is elastically deformed in the movable rubber film 74 by being fixed to the partition member at one or a plurality of locations with respect to the partition member in a state where the elastic deformation is allowed. It can be expressed with two different spring characteristics, a low pressure action state based on the elastic deformation of a single rubber and a high pressure action state accompanied by an elastic deformation of the leaf spring, and as shown in the first embodiment. In addition, substantially the same function and effect as those of the leaf spring 78 fixed to the partition member 38 at the central portion can be effectively exhibited.

  Furthermore, the present invention is not necessarily applied only to the engine mount, and can be applied to various fluid-filled vibration damping devices such as a suspension member mount and a body mount.

  Furthermore, the present invention is not necessarily applied only to the fluid-filled vibration isolator for automobiles. For example, the fluid-filled vibration-proof device for trains and other fluid-filled vibration-proof devices used for various applications are used. The present invention can be applied to an apparatus.

  In addition, although not enumerated one by one, the present invention can be carried out in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that all are included in the scope of the present invention without departing from the spirit of the present invention.

It is a longitudinal cross-sectional view which shows the engine mount as 1st embodiment of this invention, Comprising: II sectional drawing of FIG. The top view of the partition member which comprises the same engine mount. III-III sectional drawing of FIG. 4 which shows the movable rubber film which comprises the engine mount. IV-IV sectional drawing in FIG. 3 of the movable rubber film. The principal part enlarged view which shows the deformation | transformation state of a movable rubber film in the engine mount. The principal part enlarged view which shows the deformation | transformation state of a movable rubber film in the engine mount. It is a longitudinal cross-sectional view which shows the engine mount as 2nd embodiment of this invention, Comprising: VII-VII sectional drawing of FIG. The top view of the partition member which comprises the same engine mount. The graph which shows the negative pressure elimination effect in the engine mount. The graph which shows the vibration proof characteristic of the engine mount. The graph which shows the vibration proof characteristic of the engine mount. Sectional drawing of the movable rubber film employ | adopted as another aspect of this invention. Sectional drawing of the movable rubber film employ | adopted as another aspect of this invention. Sectional drawing of the movable rubber film employ | adopted as another aspect of this invention. Sectional drawing of the movable rubber film employ | adopted as another aspect of this invention. It is sectional drawing of the movable rubber film employ | adopted as another aspect of this invention, Comprising: It is XVI-XVI sectional drawing of FIG. The top view of the movable rubber film. The top view of the movable rubber film employ | adopted as another aspect of this invention. XIX-XIX sectional drawing of FIG. 18 which shows the mounting state to the partition member of the movable rubber film. The top view of the movable rubber film employ | adopted as another aspect of this invention. XXI-XXI sectional drawing of FIG. 20 which shows the mounting state to the partition member of the movable rubber film. The top view of the movable rubber film employ | adopted as another aspect of this invention. XXIII-XXIII sectional drawing of FIG. 22 which shows the mounting state to the partition member of the movable rubber film. The top view of the movable rubber film employ | adopted as another aspect of this invention. XXV-XXV sectional drawing of FIG. 24 which shows the mounting state to the partition member of the movable rubber film. The top view of the movable rubber film employ | adopted as another aspect of this invention. XXVII-XXVII sectional drawing of FIG. 26 which shows the mounting state to the partition member of the movable rubber film. Sectional drawing of the partition member employ | adopted as another aspect of this invention. Sectional drawing of the partition member employ | adopted as another aspect of this invention. Sectional drawing of the partition member employ | adopted as another aspect of this invention. Sectional drawing of the partition member employ | adopted as another aspect of this invention. Sectional drawing of the partition member employ | adopted as another aspect of this invention. Sectional drawing of the partition member employ | adopted as another aspect of this invention. Sectional drawing of the partition member employ | adopted as another aspect of this invention. The top view of the partition member employ | adopted as another aspect of this invention.

Explanation of symbols

10: Automotive engine mount, 12: First mounting bracket, 14: Second mounting bracket, 16: Rubber elastic body, 30: Diaphragm, 38: Partition member, 48: Upper communication window, 58: Lower communication window 62: receiving space, 64: pressure receiving chamber, 66: equilibrium chamber, 72: orifice passage, 74: movable rubber film, 78: leaf spring, 82: spoke spring, 84: split rim

Claims (7)

The first mounting member and the second mounting member are connected by a main rubber elastic body, and a pressure receiving chamber in which a part of the wall portion is configured by the main rubber elastic body and a part of the wall portion by the flexible membrane. In the fluid-filled vibration isolator having a configured equilibrium chamber and enclosing an incompressible fluid in the pressure receiving chamber and the equilibrium chamber, and provided with an orifice passage communicating the pressure receiving chamber and the equilibrium chamber with each other,
The partition member that partitions the pressure receiving chamber and the equilibrium chamber is provided with a communication path that communicates the pressure reception chamber and the equilibrium chamber, and is a closed rubber elasticity that is overlapped with the communication path from the pressure receiving chamber side to close the communication path. A plate is disposed so that the pressure in the pressure receiving chamber is exerted on one surface of the closed rubber elastic plate and the pressure in the equilibrium chamber is exerted on the other surface. By providing restraining means for holding the outer peripheral portion of the plate in contact with the partition member partially at a plurality of locations on the circumference, the positive pressure of the pressure receiving chamber is exerted on the closing rubber elastic plate While the closing rubber elastic plate is pressed against the partition member to block the communication path, the negative pressure of the pressure receiving chamber is exerted on the closing rubber elastic plate, thereby out of the outer peripheral portion of the closing rubber elastic plate. Hold by the restraining means Fluid filled type vibration damping device area outside the partial is characterized by being configured the communication / shutoff control means allowed to communicate with communication passage is elastically deformed in the spacing direction from the partition member.   The fluid filled type vibration damping device according to claim 1, wherein the closing rubber elastic plate is fixed to the partition member at a central portion thereof.   The reinforcing rubber elastic plate includes a reinforcing member having a plurality of spoke-like portions extending radially from a central portion toward an outer peripheral portion, and the restraining means includes the reinforcing member. Or the fluid-filled vibration isolator according to 2.   The fluid-filled vibration isolator according to claim 3, wherein the reinforcing member is integrally provided with a split rim-like portion extending in a circumferential direction of the closing rubber elastic plate at an outer peripheral side tip portion of the spoke-like portion.   The fluid-filled vibration isolator according to claim 3 or 4, wherein the reinforcing member is constituted by a leaf spring, and the leaf spring is partially fixed to the partition member.   The fluid-filled vibration isolator according to claim 3 or 4, wherein the reinforcing member is a rigid body.   The holding portion by the restraining means in the outer peripheral portion of the closing rubber elastic plate is elastically deformed in the separation direction from the partition member by the action of a negative pressure larger than the negative pressure of the pressure receiving chamber that elastically deforms a region outside the elastic member. The fluid filled type vibration damping device according to any one of claims 1 to 5, wherein the communication path is made to communicate.

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