JP2008121811A - Fluid-sealed vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid-sealed vibration isolator of a novel structure which can advantageously exhibit a vibration isolating effect against the vibration of a plurality of frequencies or the vibration of a wide-band frequency while being simplified in structure. <P>SOLUTION: An opening window 30 serving as one liquid chamber formed by connecting a pressure receiving chamber 50 and an equilibrium chamber 52 to each other is formed at a partitioning member 24, the opening window 30 is kept in a closed state by pressing the central part 82 of a flexible rubber film 38 against the opening peripheral part of the opening window 30 of the partitioning member 24 by using an output member 62 of an air-pressure type actuator 58 which is arranged at a side opposite to the equilibrium chamber 52 with the flexible rubber film 38 in between, the elastic deformation of the inside of a recess 84 of the flexible rubber film 38 is permitted by forming the recess 84 on the tip face of the output member 62, and a liquid-pressure absorbing mechanism with a deformation-amount limit mechanism is arranged which limits the amount of the elastic deformation of the flexible rubber film 38 by making the flexible rubber film 38 abut on the inside face of the recess 84. By this, a valve body containing the liquid-pressure absorbing mechanism is arranged which opens and closes the opening window 30 by the operation of the air-pressure type actuator 58. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid-filled vibration isolator that obtains a vibration-proof effect based on the flow action of an incompressible fluid enclosed therein, and in particular, is balanced with a pressure receiving chamber filled with the incompressible fluid. The present invention relates to a fluid-filled vibration isolator in which chambers communicate with each other through an orifice passage.

  Conventionally, as a kind of anti-vibration coupling body and anti-vibration support body interposed between members constituting the vibration transmission system, anti-vibration is based on the flow action such as resonance action of incompressible fluid enclosed inside. 2. Description of the Related Art A fluid-filled vibration isolator that is effective is known. In this fluid-filled vibration isolator, the first mounting member is spaced apart on the one axial side opening side of the cylindrical second mounting member, and the first mounting member and the second mounting member are It is connected with the main rubber elastic body, and the other opening in the axial direction of the second mounting member is covered with a flexible film, so that it is not compressed between the main rubber elastic body and the flexible film. A fluid chamber in which a sexual fluid is sealed. In addition, the fluid chamber is partitioned by the partition member supported by the second mounting member, and the pressure receiving chamber and the wall portion in which part of the wall portion is formed of a main rubber elastic body on both sides of the partition member in the fluid chamber An equilibrium chamber made of a flexible membrane is formed, and the pressure receiving chamber and the equilibrium chamber communicate with each other through an orifice passage formed in the partition member. According to such a structure, a relative pressure fluctuation difference is generated between the pressure receiving chamber and the equilibrium chamber in accordance with the vibration input, and the amount of fluid flowing through the orifice passage is ensured. An anti-vibration effect can be obtained based on a fluid action such as an action. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 08-028623) discloses that, and application to an engine mount, a body mount, a differential mount for automobiles, and other suspension member mounts is being studied. .

  However, in the conventional fluid-filled vibration isolator shown in Patent Document 1, the vibration isolation effect that is exhibited based on the resonance action of the fluid that flows through the orifice passage is relatively high when the orifice passage is tuned in advance. Since it is limited to a narrow frequency range, there is a problem that it cannot cope with the required advanced anti-vibration characteristics.

  Therefore, in Patent Document 2 (Japanese Patent Laid-Open No. 08-270718), the first and second orifice passages tuned to different frequency ranges are provided, and the equilibrium chamber of the orifice passage tuned to the higher frequency range is provided. Have been proposed that can be opened and closed with a valve body made of a flexible membrane. According to this, the second orifice passage is switched between the communication state and the cutoff state according to the vibration to be vibration-isolated, and the two orifice passages are selectively functioned to thereby prevent vibration against vibrations in two frequency ranges. An effect will be acquired.

  However, in recent years, a higher level of vibration isolation performance has been demanded, and even with the fluid-filled vibration isolation device described in Patent Document 2, the required vibration isolation performance may still not be sufficiently realized. . Specifically, in general, engine mounts for automobiles are required to have anti-vibration performance (high damping effect) against low-frequency large-amplitude vibrations such as engine shakes when the automobile is running, running noise, etc. Are required to have anti-vibration performance (vibration insulation effect) against high-frequency, small-amplitude vibration of the vehicle, and further, anti-vibration performance (vibration insulation effect) against medium-frequency medium amplitude vibration such as idling vibration when the vehicle is stopped.

  With respect to such required characteristics, the vibration isolator having the conventional structure described in Patent Document 2 described above is effective only for vibrations in two types of frequency ranges in which the two orifice passages are respectively tuned. Could not get. In addition, since the two orifice passages are formed, the structure of the partition member that partitions the pressure receiving chamber and the equilibrium chamber is complicated, and there is a problem that the manufacturing operation is troublesome and the manufacturing cost is increased.

  In addition, the applicant of the present invention previously described in Patent Document 3 (Japanese Patent Application Laid-Open No. 10-089402), the opening of the orifice passage tuned to the high frequency side region of the two orifice passages tuned to different frequency regions is a rubber. By opening and closing with a membrane, a fluid-filled type anti-blocking structure with an improved structure that can selectively express in two different frequency ranges the frequency range where the low dynamic spring action is exhibited by the high-frequency side tuned orifice passage. A vibration device was proposed. According to this fluid-filled vibration isolator, it is possible to obtain an anti-vibration effect against low-frequency vibration such as engine shake by the low-frequency side tuned orifice passage, and idling vibration or the like depending on the closed state of the high-frequency side orifice passage. It is also possible to obtain an anti-vibration effect against vibrations in two different frequency ranges in the medium to high frequency range.

  However, in the fluid-filled vibration isolator disclosed in Patent Document 3, the tuning frequency of the orifice passage is changed by selectively switching the wall spring rigidity of the equilibrium chamber in which the orifice passage tuned to the high frequency side is communicated. The orifice passage itself has a constant passage length and passage sectional area. Therefore, even if the high frequency side orifice passage is opened and closed, it is difficult to greatly change the frequency range in which the vibration isolation effect is exhibited. Therefore, for example, the idling vibration in the middle frequency range which is a problem when the vehicle is stopped and the middle to high speed traveling booming noise which is a problem in traveling can be expressed by opening and closing the orifice passage. It was extremely difficult. In addition, since it is necessary to form two orifice passages, the problem that the structure of the partition member is complicated, the manufacturing operation is troublesome, and the manufacturing cost is high is inherent.

Japanese Patent Application Laid-Open No. 08-028623 Japanese Patent Laid-Open No. 08-270718 Japanese Patent Laid-Open No. 10-089402

  Here, the present invention has been made in the background as described above, and the problem to be solved is, for example, an engine shake in a low frequency range, an idling vibration in a mid frequency range, and a high frequency range in an automobile. A fluid-filled vibration isolator with a new structure suitable for automobile engine mounts and the like that can exhibit effective vibration isolation effects against multiple vibrations with significantly different frequencies, such as high-speed booming noise. Is to provide.

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

  That is, the feature of the present invention is that the first mounting member and the second mounting member having a cylindrical shape are spaced apart from each other in the axial direction, and the first mounting member and the second mounting member are separated from each other. The mounting member is connected with the main rubber elastic body, and the other opening in the axial direction of the second mounting member is covered with a flexible rubber film, so that the main rubber elastic body and the flexible rubber film are covered. A fluid chamber in which an incompressible fluid is sealed is formed, the fluid chamber is partitioned by a partition member supported by the second mounting member, and wall portions are provided on both sides of the partition member in the fluid chamber. Forming a pressure receiving chamber made up of a part of the main rubber elastic body and an equilibrium chamber made up of a part of the wall made up of the flexible rubber film, and making the pressure receiving chamber and the equilibrium chamber communicate with each other. In a fluid filled type vibration damping device provided with an orifice passage, the pressure receiving chamber and the equilibrium chamber are connected to each other. An opening window serving as one liquid chamber is provided in the central portion of the partition member, and a pneumatic actuator is disposed on the opposite side of the equilibrium chamber with the flexible rubber film interposed therebetween, so that a rigid actuator in the pneumatic actuator is provided. The front end surface of the output member is opposed to the opening window across the flexible rubber film, and the central portion of the flexible rubber film is pressed against the opening peripheral edge of the opening window in the partition member. The flexible actuator is provided with a biasing means for holding the opening window in a closed state in the pneumatic actuator, and a recess is formed in the front end surface of the output member, and is pressed against the partition member by the output member. With a deformation amount limiting mechanism that allows elastic deformation of the rubber film into the recess and limits the elastic deformation amount of the flexible rubber film by contacting the inner surface of the flexible rubber film. By configuring the hydraulic pressure absorption mechanism Lies in the provision of the liquid pressure absorption mechanism built-valve body for opening and closing the opening window by the operation of the air pressure actuator.

  In such a fluid-filled vibration isolator having a structure according to the present invention, when a vibration is input in the tuning frequency range of the orifice passage, the flexible rubber film is pressed against the peripheral edge of the opening window of the partition member to open the opening window. By maintaining the closed state, the pressure leakage of the pressure receiving chamber through the opening window can be suppressed, and the difference in relative pressure fluctuation between the pressure receiving chamber and the equilibrium chamber can be effectively generated. As a result, it is possible to secure a sufficient amount of fluid flowing through the orifice passage and to obtain a target vibration-proofing effect (orifice effect) based on the fluid action such as the resonance action of the fluid.

  In particular, according to this structure, when vibration with a relatively large amplitude is input in the tuning frequency range of the orifice passage in a state where the opening window of the partition member is closed by the flexible rubber film, the flexible rubber film is flexible. The amount of elastic deformation of the flexible rubber film is limited by the elastic rubber film coming into contact with the inner surface of the recess. As a result, the pressure fluctuation in the pressure receiving chamber is suppressed from being absorbed by the elastic deformation of the flexible rubber film, and the amount of fluid flow through the orifice passage is stably secured. In particular, an anti-vibration effect against low-frequency large-amplitude vibration can be advantageously exhibited.

  Further, when vibration in a frequency range higher than the tuning frequency of the orifice passage is input, the pressure fluctuation in the pressure receiving chamber increases due to the clogged state of the orifice passage, and high dynamic springs are caused. However, by releasing the pressing state of the flexible rubber film against the partition member by the output member and opening the opening window, the pressure receiving chamber and the equilibrium chamber are connected to each other to form an integral chamber. As a result, high dynamic springs can be avoided, and the anti-vibration effect can be stably exhibited based on the elastic deformation of the flexible rubber film in the equilibrium chamber.

  Further, when vibration in a frequency range higher than the tuning frequency of the orifice passage is input in a state where the flexible rubber film is pressed against the peripheral edge of the opening window of the partition member and the opening window is closed, the orifice passage Due to the clogging state, the high dynamic spring is caused. Here, in the vibration isolator according to the present invention, the elastic deformation of the flexible rubber film is allowed by the recess of the output member in a state where the flexible rubber film is pressed against the partition member. The pressure fluctuation in the chamber is absorbed on the basis of the elastic deformation of the flexible rubber film. As a result, the high dynamic spring is avoided and the desired vibration isolation effect can be stably obtained.

  In short, the valve body that opens and closes the opening window by the operation of the pneumatic actuator allows elastic deformation into the recess of the flexible rubber film pressed against the partition member by the output member, and the recess of the flexible rubber film The structure has a built-in hydraulic pressure absorbing mechanism with a deformation amount limiting mechanism that limits the amount of elastic deformation by contact with the inner surface. As a result, a plurality of different frequency ranges and amplitudes such as vibrations in the tuning frequency range of the orifice passage, vibrations in a higher frequency range than the tuning frequency, vibrations having a large amplitude in the tuning frequency range can be achieved while achieving compactness as a whole. High vibration-proof performance can be exhibited against vibrations of

  In addition, the amount of elastic deformation of the flexible rubber film that absorbs pressure fluctuations in the pressure-receiving chamber when vibration is input in a frequency range higher than the tuning frequency of the orifice passage is secured to absorb vibration of high-frequency fine amplitude. Therefore, the amount of deformation is generally small, and therefore it is not necessary to form the recesses with a particularly large size. That is, the separation distance between the flexible rubber film and the inner surface of the recess can be set small. Therefore, in addition to being able to advantageously reduce the size of the vibration isolator, it is possible to reliably suppress the elastic deformation of the flexible rubber film at the time of inputting a large amplitude vibration, which is a problem. Reliability can be improved.

  In the fluid filled type vibration damping device according to the present invention, the orifice passage is tuned to a low frequency range corresponding to an engine shake, and the opening window is closed by the valve body with a built-in hydraulic pressure absorption mechanism. In the case of vibration input with high frequency and small amplitude corresponding to the traveling noise under the condition, the amount of deformation that does not cause the flexible rubber film to come into contact with the inner surface of the recess is obtained. When the vibration is input, the elasticity of the flexible rubber film constituting the valve body with the built-in hydraulic pressure absorbing mechanism and the recess are set such that the deformation amount of the flexible rubber film contacts the inner surface of the recess. The vehicle engine mount may be configured by setting the size.

  In such a fluid-filled vibration isolator having a structure according to the present invention, the above-described valve body with a built-in hydraulic pressure absorption mechanism is provided, so that the device can be made compact and a traveling booming noise or the like can be obtained. The anti-vibration effect of high-frequency small-amplitude vibration and the anti-vibration effect of low-frequency large-amplitude vibration such as engine shake can be advantageously exhibited, and can be advantageously employed as an automobile engine mount.

  Further, in the above-described fluid filled type vibration isolator, the biasing force of the biasing means is resisted by being connected to the pneumatic actuator and applying a negative pressure to the pneumatic actuator when the automobile is stopped. By holding the hydraulic pressure absorbing mechanism built-in type valve body from the opening window of the partition member in a separated state to open the opening window, while allowing the pneumatic actuator to communicate with the atmosphere while the automobile is running And a structure including air pressure control means for holding the valve body with a built-in hydraulic pressure absorbing mechanism pressed against the opening window of the partition member based on the urging force of the urging means to block the opening window. Can be suitably employed.

  According to such a structure, the pneumatic actuator that switches the opening window between the open state and the closed state can be easily realized, which can facilitate the manufacturing work and reduce the manufacturing cost.

  Further, in the fluid filled type vibration damping device according to the present invention, the valve body with a built-in hydraulic pressure absorption mechanism includes the concave portion covered with the flexible rubber film in a state where the opening window is closed. A structure in which an air communication path that allows the internal space to communicate with the external space is formed is preferably employed.

  According to such a structure, since the internal space of the recess covered with the flexible rubber film is not sealed under the closed state of the open window, air accumulates in the internal space, and thus the open window Abnormal noise generated when switching between the closed state and the open state is effectively suppressed.

  Furthermore, in the above-described fluid-filled vibration isolator, the output member of the pneumatic actuator includes an annular elastic pressing protrusion on the outer peripheral portion of the tip surface, and the output member is supported by the elastic pressing protrusion. The flexible rubber film is configured to press against the opening peripheral edge of the opening window in the partition member, and the elastic pressing protrusion is provided with a communication groove at least at one place on the circumference, A structure in which the air communication path is formed by the communication groove is preferably employed.

  According to such a structure, durability of these output members and a partition member can be improved by pressing an output member against a partition member bufferingly based on the elasticity of an elastic press protrusion. In addition, since the air communication passage is easily realized by using the communication groove of the elastic pressing protrusion, the manufacture can be facilitated.

  In the fluid filled type vibration damping device according to the present invention, the flexible rubber film is annularly pressed against the opening peripheral edge of the opening window of the partition member by the output member of the pneumatic actuator. A structure in which a plurality of irregularities are provided in the circumferential direction on at least one surface of the pressing portion can be suitably employed.

  According to such a structure, a gap is provided between the abutment surfaces of the output member and the partition member, and thereby, an impact sound caused by the abutment or abnormal noise generated when separating from the abutment state is effective. Can be suppressed.

  In the fluid filled type vibration damping device according to the present invention, the flexible rubber film is pressed by the outer peripheral portion of the front end surface of the output member and the outer peripheral portion of the front end surface of the output member in the pneumatic actuator. A structure in which the opening peripheral edge portion of the opening window of the partition member is a contact holding surface extending in the circumferential direction with an arcuate curved cross-sectional shape that is similar to each other across the flexible rubber film is preferable. Can be adopted.

  According to such a structure, one of the output member and the partition member is brought into contact with the other so that the contact state is stabilized, so that the opening window is more reliably secured by the flexible rubber film. The orifice effect can be further improved.

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

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

  More specifically, the first mounting member 12 has a small-diameter substantially cylindrical shape or a truncated cone shape, and a screw hole 18 is provided in the central portion thereof.

  On the other hand, the second mounting bracket 14 has a substantially cylindrical shape with a large diameter, and a caulking portion 20 that has a ring shape larger in diameter than the second mounting bracket 14 is integrally formed at the lower end in the axial direction. ing. Further, the first mounting bracket 12 is spaced apart from the opening side of one of the second mounting brackets 14 (upper in FIG. 1), and the central axes of both the brackets 12 and 14 are positioned substantially on the same line. In addition, a main rubber elastic body 16 is disposed between the first mounting bracket 12 and the second mounting bracket 14.

  The main rubber elastic body 16 has a substantially truncated cone shape, and a mortar-shaped large-diameter recess 22 that opens downward is provided on the large-diameter side end face. In addition, the first mounting bracket 12 is vulcanized and bonded to the small diameter side end surface of the main rubber elastic body 16 in a state where the whole is embedded, and the outer peripheral surface of the large diameter side end portion of the main rubber elastic body 16. In this case, the inner peripheral surface of the second mounting bracket 14 is vulcanized and bonded over substantially the whole. In short, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the first mounting bracket 12 and the second mounting bracket 14. Thus, the first mounting bracket 12 and the second mounting bracket 14 are elastically connected to each other by the main rubber elastic body 16 and one of the second mounting brackets 14 in the axial direction (in FIG. 1, The upper opening is fluid-tightly closed by the main rubber elastic body 16. A thin seal rubber layer integrally formed with the main rubber elastic body 16 is formed on the inner side of the caulking portion 20 of the second mounting bracket 14. In the integrally vulcanized molded product of the main rubber elastic body 16 provided with the first and second mounting brackets 12 and 14, the opening side on the other side in the axial direction of the second mounting bracket 14 (lower in FIG. 1). The partition member 24 and the orifice member 28 are assembled. The partition member 24 and the orifice member 28 are formed using a hard material such as a synthetic resin material or a metal material.

  The partition member 24 has a thin disk shape, and a circular through hole 30 serving as an opening window is provided through the center. In particular, the central portion of the partition member 24 has a stepped plate shape whose diameter dimension gradually decreases toward one axial direction (upward in FIG. 1), and a through hole 30 is formed in the center thereof. For this reason, the peripheral portion of the through hole 30 protrudes in one axial direction (upward in FIG. 1) from the intermediate portion and the outer peripheral portion of the partition member 24 in the direction perpendicular to the axis, and has a substantially annular plate shape. 32 has an integrally formed structure. The outer peripheral portion of the contact support portion 32 extends in the circumferential direction with an arcuate curved cross-sectional shape.

  The orifice member 28 has a thick annular plate shape as a whole. The opening part of one axial direction (downward in FIG. 1) of the center of the orifice member 28 is made into the taper shape from which a radial dimension becomes small toward the other (upward in FIG. 1) axial direction. A circumferential groove 36 extending in the circumferential direction with a predetermined length (a little less than one round in the present embodiment) is formed in the outer peripheral portion of the orifice member 28. The inner diameter dimension of the orifice member 28 is larger than the diameter dimension of the through hole 30 of the partition member 24, and is slightly larger than the outer diameter dimension of the contact support portion 32. The outer diameter dimension of the orifice member 28 is made smaller than the outer diameter dimension of the partition member 24.

  The partition member 24 and the orifice member 28 are positioned on the concentric shaft and overlap each other in the axial direction. The outer peripheral edge portion of the partition member 24 is fitted into a caulking portion 20 formed integrally with the axial end portion of the second mounting member 14 and overlapped with the axial end portion in the axial direction. A sealing rubber layer integrally formed with the main rubber elastic body 16 is interposed between the overlapping surfaces of the partition member 24 and the axial end of the second mounting bracket 14 so that the overlapping surface is It is fluidly superimposed. In addition, a diaphragm 38 as a flexible rubber film is assembled to an end portion in the axial direction of the second mounting member 14 provided with the partition member 24 and the orifice member 28.

  The diaphragm 38 is formed of a thin elastic rubber film having a slack in the axial direction, and has a substantially disk shape as a whole. A fixed tube fitting 40 is fixed to the outer peripheral portion of the diaphragm 38. The fixed cylinder fitting 40 has a substantially cylindrical shape with a large diameter, and an outer flange-like portion 42 in the shape of an annular plate spreading outward in the direction perpendicular to the axis at one end in the axial direction (upper in FIG. 1). Are integrally formed, and an annular flange portion 44 having an annular plate shape extending inwardly in the direction perpendicular to the axis is integrally formed at the other axial end (lower in FIG. 1). In addition, the inner diameter dimension of the cylindrical main body of the fixed tubular fitting 40 is larger than the outer diameter dimension of the orifice member 28, and the outer diameter dimension of the outer flange-shaped portion 42 is substantially the same as the outer diameter dimension of the partition member 24. It is the same. The inner flange-shaped portion 44 is vulcanized and bonded to the outer peripheral portion of the diaphragm 38, so that the diaphragm 38 is formed as an integrally vulcanized molded product including the fixed tube fitting 40. In addition, a seal rubber layer 46 integrally formed with the diaphragm 38 is attached and formed on the inner surface of the cylindrical main body, the outer flange-shaped portion 42, and the inner flange-shaped portion 44 of the fixed tube fitting 40.

  The fixed tube fitting 40 in such a vulcanized product of the diaphragm 38 is fitted and fixed to the orifice member 28, and the outer flange-like portion 42 of the fixed tube fitting 40 is overlapped with the outer peripheral portion of the partition member 24 in the axial direction. In addition, the inner flange-shaped portion 44 of the fixed tubular fitting 40 is overlapped with the outer peripheral portion of the orifice member 28 in the axial direction. Since the sealing rubber layer 46 is sandwiched between the overlapping surfaces of the fixed cylindrical metal fitting 40 and the partition member 24 or the orifice member 28, the inner peripheral surface of the fixed cylindrical metal fitting 40, the outer peripheral surface of the partition member 24, or the orifice member. The outer peripheral surface of 28 is superposed fluid tightly.

  Then, the outer peripheral portion of the partition member 24 and the outer flange-shaped portion 42 of the fixed tubular fitting 40 that are overlapped with each other in the axial direction are fitted into the caulking portion 20 of the second mounting bracket 14 and are caulked to the caulking portion 20. Is given. As a result, the integral vulcanized molded product of the diaphragm 38 having the fixed tubular fitting 40, the partition member 24, and the orifice member 28 are integrally joined to the main rubber elastic body 16 having the first and second mounting fittings 12 and 14. While being assembled with the sulfur molded product, the other opening in the axial direction of the second mounting bracket 14 is covered with a diaphragm 38 in a fluid-tight manner. In addition, based on the fact that the partition member 24 and the fixed tube fitting 40 are fixed by caulking, the orifice member 28 disposed between the partition member 24 and the fixed tube fitting 40 is clamped and fixed in the axial direction.

  A space between the opposing surfaces of the main rubber elastic body 16 and the diaphragm 38 is sealed with respect to the external space, and a fluid chamber 48 in which an incompressible fluid is sealed is formed. As the sealing fluid, for example, water, alkylene glycol, polyalkylene glycol, silicone oil or the like is adopted, and in order to effectively obtain a vibration isolation effect based on a fluid action such as a resonance action of the fluid, 0.1 Pa · It is desirable to employ a low-viscosity fluid of s or less. The incompressible fluid is sealed in the fluid chamber 48, for example, with respect to the integrally vulcanized molded product of the main rubber elastic body 16 including the first and second mounting brackets 12 and 14, the partition member 24 and This is advantageously realized by performing the assembly of the diaphragm 38 in an incompressible fluid.

  In addition, the partition member 24 is disposed in the axially intermediate portion of the fluid chamber 48 so as to expand in the direction perpendicular to the axis, so that the fluid chamber 48 is divided into two vertically in the axial direction across the partition member 24. A part of the wall portion is composed of the main rubber elastic body 16 on the one axial side (the upper side in FIG. 1) sandwiching the partition member 24, and the first mounting bracket 12 and the second mounting bracket. A pressure receiving chamber 50 is formed in which a pressure fluctuation is generated based on elastic deformation of the main rubber elastic body 16 when vibration is input between the two. Further, on the other side in the axial direction (downward in FIG. 1) across the partition member 24, a part of the wall portion is constituted by the diaphragm 38, and the volume change is easily performed based on the elastic deformation of the diaphragm 38. An allowable equilibrium chamber 52 is formed.

  Further, one end in the circumferential direction of the circumferential groove 36 of the orifice member 28 penetrates the partition member 24 and is connected to the pressure receiving chamber 50, and the other end in the circumferential direction of the circumferential groove 36 is connected to the orifice member 28. Are connected to the equilibrium chamber 52 through the bottom or the peripheral wall of each. As a result, an orifice passage 54 that allows the pressure receiving chamber 50 and the equilibrium chamber 52 to communicate with each other is formed, and fluid flow through the orifice passage 54 is allowed between the chambers 50 and 52.

  In the present embodiment, the resonance frequency of the fluid that is allowed to flow through the orifice passage 54 is effective against vibrations in a low frequency region around 10 Hz corresponding to an engine shake or the like based on the resonance action of the fluid. It is tuned so that the damping effect is demonstrated. The tuning of the orifice passage 54 is performed by, for example, the rigidity of the wall springs of the pressure receiving chamber 50 and the equilibrium chamber 52, that is, the main rubber elastic body 16 corresponding to the amount of pressure change required to change the chambers 50 and 52 by a unit volume. The pressure fluctuation transmitted through the orifice passage 54 can be adjusted by adjusting the passage length and passage sectional area of the orifice passage 54 in consideration of the characteristic values based on the elastic deformation amounts of the diaphragm 38 and the diaphragm 38. The frequency at which the phase changes to a substantially resonant state can be grasped as the tuning frequency of the orifice passage 54.

  Further, the through hole 30 formed in the center of the partition member 24 constitutes an opening window that connects the pressure receiving chamber 50 and the equilibrium chamber 52 to each other to form one liquid chamber.

  Thus, the pneumatic actuator 58 is assembled to the mount body having the pressure receiving chamber 50, the equilibrium chamber 52, the orifice passage 54, and the opening window (through hole 30). This pneumatic actuator 58 has a structure in which an output fitting 62 as an output member is assembled from the inside to a housing fitting 60 having a substantially bottomed cylindrical shape.

  The output fitting 62 has a substantially bottomed cylindrical shape that opens downward, and is formed using a hard material such as a metal material. Further, a through hole is provided at an appropriate location in the bottom of the output fitting 62, and an elastic rubber layer 64 vulcanized and molded through the through hole extends over substantially the entire inner and outer peripheral surface of the output fitting 62. Are formed. In addition, a tapered flange-shaped peripheral wall rubber 66 that is integrally formed with the elastic rubber layer 64 and extends obliquely downward is provided at the peripheral edge of the lower end opening of the output fitting 62. Further, an annular press fitting 68 is vulcanized and bonded to the outer peripheral edge of the peripheral wall rubber 66. A seal lip formed integrally with the peripheral wall rubber 66 is attached to the lower end portion of the press-fit metal fitting 68.

  The press-fit metal fitting 68 is press-fitted and fixed to the peripheral wall portion of the housing metal fitting 60, and the lower end portion is closely adhered to the bottom portion of the housing metal fitting 60 via the seal lip. Thereby, the opening of the output metal fitting 62 is covered with the bottom of the housing metal fitting 60, and the pressure adjusting air chamber 70 is formed between the output metal fitting 62 and the bottom of the housing metal fitting 60.

  Further, a coil spring 72 as an urging means that exerts an urging force in the axial direction is accommodated in the regulated air chamber 70, and one end (upper in FIG. 1) is output via the elastic rubber layer 64. While being supported by the upper bottom portion of the metal fitting 62, the other end (lower in FIG. 1) is supported by the bottom portion of the housing metal fitting 60. As a result, a biasing force in the separation direction is constantly exerted between the output fitting 62 and the housing fitting 60. An air port 74 is provided through the center of the bottom of the housing fitting 60. Through this air port 74, the pressure in the regulated air chamber 70 can be controlled from the outside.

  The fixed barrel fitting 40 of the mount body is press-fitted and fixed to the housing fitting 60 of such a pneumatic actuator 58. Particularly in the present embodiment, the flange-like portion 76 integrally formed at the opening end of the housing fitting 60 caulks the outer peripheral portion of the partition member 24 and the outer flange-like portion 42 of the fixed tubular fitting 40 in the second mounting fitting 14. The position of the pneumatic actuator 58 in the axial direction relative to the mount body is defined by being superimposed on the lower end portion of the fixed caulking portion 20. Further, the front end surface of the output fitting 62 is opposed to the through hole 30 of the partition member 24 with the diaphragm 38 interposed therebetween.

  In addition, the screw hole 18 of the first mounting bracket 12 is screwed and fixed to the mounting member on the power unit side using a fixing bolt (not shown), and an outer bracket (not shown) is fixed to the second mounting bracket 14. The bracket is fixed to a mounting member on the vehicle body side with a bolt or the like. As a result, the engine mount 10 is mounted between the power unit and the vehicle body so that the power unit is supported on the vehicle body in a vibration-proof manner.

  Under such a mounted state, an air pipe 78 is connected to the air port 74 of the housing metal fitting 60, and the pressure regulating air chamber 70 is connected to the switching valve 80 through the air pipe 78. The switching valve 80 is constituted by, for example, an electromagnetic valve or the like, and allows the pressure-controlled air chamber 70 to selectively communicate with the atmosphere and a predetermined negative pressure source 81. As the negative pressure source 81, for example, a suction system on the intake side of an automobile, an accumulator, or the like is employed. The switching valve 80 is connected to a control device (not shown). In the control device, necessary information is input from various sensors provided in the vehicle, such as the vehicle speed, the engine speed, the speed reducer selection position, the throttle opening, etc. Based on such information, a drive control signal is output to an electromagnetic solenoid constituting the switching valve 80 by a microcomputer software or the like according to a preset program to switch the switching valve 80. It is like that.

  In such a state where the pressure adjusting air chamber 70 is connected to the atmosphere, the elasticity of the peripheral wall rubber 66 and the elasticity of the coil spring 72 act on the output fitting 62, so that the output fitting 62 elastically protrudes upward. The upper bottom portion (tip surface) of the output fitting 62 is in contact with the lower center surface of the diaphragm 38 via the elastic rubber layer 64, and the upper surface of the diaphragm 38 is the peripheral portion (surface) of the through hole 30 of the partition member 24. ).

  In particular, the central portion of the diaphragm 38 with which the output fitting 62 abuts is a movable film portion 82 having a substantially disk shape, and is thicker than the radially intermediate portion and the outer peripheral portion of the diaphragm 38.

  In addition, a recess 84 is formed in the central portion of the front end surface of the output metal fitting 62 so as to open upward in a substantially circular shape, whereby the outer peripheral portion 86 of the front end surface of the output metal fitting 62 is formed in the central portion. It is set as the form which protruded axially outward rather than. In particular, the outer peripheral portion 86 of the front end surface of the output fitting 62 has an arcuate curved cross-sectional shape.

  Further, the elastic rubber layer 64 is also applied to the outer peripheral portion 86 of the output fitting 62 based on the fact that the elastic rubber layer 64 is applied to the recess 84 over substantially the whole. The elastic rubber layer 64 attached to the outer peripheral portion 86 is an annular elastic pressing protrusion 88. The elastic pressing protrusion 88 extends in the circumferential direction with a substantially constant thickness dimension over the entire outer peripheral portion 86, thereby exhibiting an arcuate curved cross-sectional shape similar to the outer peripheral portion 86.

  Further, as shown in FIG. 2, the elastic pressing protrusion 88 has a plurality of communication grooves 90 that extend in the radial direction and allow the inner peripheral edge and the outer peripheral edge of the elastic pressing protrusion 88 to communicate with each other. Is formed. In the present embodiment, four communication grooves 90, 90, 90, 90 are provided at substantially equal intervals in the circumferential direction of the elastic pressing protrusion 88.

  Thus, as described above, when the regulated air chamber 70 is connected to the atmosphere and the output fitting 62 is urged upward by the coil spring 72, the outer peripheral portion 86 of the output fitting 62 causes the elastic pressing projection 88 to move. The outer peripheral portion of the movable film portion 82 of the diaphragm 38, and the outer peripheral portion of the movable film portion 82 contacts the abutting support portion 32 at the peripheral edge portion of the through hole 30 of the partition member 24. The pressed state is held based on the urging force. In the present embodiment, the outer peripheral portion of the movable film portion 82 is configured as an annular pressing portion.

  Thus, the state in which the through hole 30 that allows the pressure receiving chamber 50 and the equilibrium chamber 52 to communicate with each other is closed by the movable film portion 82 at the center of the diaphragm 38 is maintained, and the through hole 30 is blocked. As is clear from the above description, the outer peripheral portion 86 of the front end surface of the output fitting 62 and the outer peripheral portion of the abutting support portion 32 of the partition member 24 are similar to each other with an arcuate curved cross-sectional shape sandwiching the diaphragm 38. The contact clamping surface extends in the circumferential direction.

  Further, when the movable film portion 82 is pressed against the abutting support portion 32 of the partition member 24 by the output metal fitting 62, the movable film portion is provided by providing the recess 84 at the center of the front end surface of the output metal fitting 62. An internal space 92 is formed between the movable film portion 82 and the center of the front end surface of the output fitting 62 in a form in which the 82 is spread flat in a direction substantially perpendicular to the axis.

  Therefore, the movable film portion 82 is elastically deformed toward the internal space 92 in the recess 84 in a state where the outer peripheral portion is pressed against the abutting support portion 32 of the partition member 24 by the outer peripheral portion of the output fitting 62. Is allowed.

  In particular, in the present embodiment, the movable film portion 82 is attached to the inner surface of the recess 84 when a high-frequency, small-amplitude vibration corresponding to a traveling boom noise or the like is input with the through hole 30 closed by the movable film portion 82. While the amount of deformation does not reach the elastic rubber layer 64, the movable film portion 82 is formed on the inner surface of the recess 84 (elastic rubber layer 64) when low-frequency and large-amplitude vibration corresponding to engine shake is input. The elasticity of the movable film portion 82 and the size of the recess 84 are set so that the deformation amount comes into contact. In addition, the natural frequency of the movable film portion 82 is tuned to a high-frequency vibration frequency range of about 80 to 100 Hz corresponding to traveling noise and the like.

  The internal space 92 is communicated with the space between the outer peripheral portion of the diaphragm 38 in the housing metal fitting 60 and the peripheral wall rubber 66 through the communication groove 90 formed in the elastic pressing protrusion 88 of the output metal fitting 62. The housing fitting 60 is communicated with the external space through a through hole 94 penetrating the peripheral wall portion. That is, the communication groove 90 forms an air communication path that allows the internal space 92 of the recess 84 covered with the movable film portion 82 of the diaphragm 38 to communicate with the external space with the through hole 30 closed. .

  On the other hand, under the state in which the regulated air chamber 70 is connected to the negative pressure source 81, the negative pressure exerted in the air chamber 70 and the external atmospheric pressure are resisted against the elasticity of the peripheral wall rubber 66 and the elasticity of the coil spring 72. Based on the pressure difference, the output fitting 62 is sucked inward of the regulated air chamber 70 and is displaced downward in the axial direction. As a result, as shown in FIG. 3, the outer peripheral portion of the movable film portion 82 of the diaphragm 38 is separated from the abutting support portion 32 at the peripheral edge portion of the through hole 30 of the partition member 24. Is opened, and the pressure receiving chamber 50 and the equilibrium chamber 52 are in communication with each other through the through hole 30.

  In the present embodiment, the switching valve 80 is switched by the control device according to the traveling state of the automobile and the stopped state. That is, under the traveling state, the regulated air chamber 70 is connected to the atmosphere. On the other hand, the regulated air chamber 70 is connected to the negative pressure source 81 when the vehicle is stopped. In the present embodiment, the pneumatic control means for holding the movable film portion 82 against the peripheral edge of the through hole 30 based on the biasing force of the coil spring 72 and blocking the through hole 30 is the switching valve 80 or the control. It is configured to include the device.

  Here, one of the specific operation | movement aspects in the engine mount 10 is shown. There are three types of vibration that should be isolated: (1) engine shake, which is low-frequency, large-amplitude vibration, (2) running noise, which is high-frequency, small-amplitude vibration, and (3) idle vibration, which is medium-frequency, medium-amplitude vibration. The anti-vibration effect for each vibration will be described below. Note that (1) the engine shake and (2) the running-over noise are vibrations that are problematic when the automobile is running, and (3) idling vibrations are vibrations that are problematic when the automobile is stopped.

(1) Anti-Vibration Effect against Engine Shake When a low-frequency large-amplitude vibration such as an engine shake is input, a large amplitude pressure fluctuation is induced in the pressure receiving chamber 50. At that time, the regulated air chamber 70 is connected to the atmosphere, and the state in which the through hole 30 of the partition member 24 is closed by the movable film portion 82 of the diaphragm 38 based on the biasing force of the coil spring 72 is maintained. . Therefore, as the large pressure fluctuation is generated in the pressure receiving chamber 50, the movable film portion 82 is elastically deformed into the recess 84. In particular, when the vehicle travels on a speed breaker, a rough road surface, or the like, a larger pressure fluctuation is induced, and the amount of elastic deformation toward the recess 84 of the movable film portion 82 increases. The urging force of the coil spring 72 presses the movable film portion 82 around the through hole 30 against the positive pressure of the pressure receiving chamber 50 at the time of vibration input exerted on the movable film portion 82 through the through hole 30. It is set to a size large enough to hold the hole 30 in the closed state.

  In this case, as shown in FIG. 4, the movable film portion 82 is brought into contact with the elastic rubber layer 64 attached to the inner surface of the recess 84 in the upper end surface of the output metal fitting 62. The amount of elastic deformation is limited. That is, the deformation amount limiting mechanism for limiting the elastic deformation amount of the movable film portion 82 includes the output fitting 62 and the inner surface of the recess 84.

  As a result, the pressure absorbing action of the movable film portion 82 cannot substantially function for low-frequency large-amplitude vibration such as engine shake. The amount of fluid flow through the orifice passage 54 is effectively ensured by the relative pressure fluctuation generated in the engine, and the vibration isolation effective for the engine shake is based on the resonance action of the fluid flowing through the orifice passage 54. The effect (high attenuation effect) is exhibited.

(2) Anti-vibration effect against traveling boom noise, etc. When a high frequency small amplitude vibration such as a traveling boom noise higher than the tuning frequency of the orifice passage 54 is input, a pressure fluctuation with a small amplitude is induced in the pressure receiving chamber 50. Become. At that time, as described in the above (1), the regulated air chamber 70 is connected to the atmosphere, and the through-hole 30 of the partition member 24 is formed on the movable film portion of the diaphragm 38 based on the urging force of the coil spring 72. The state closed at 82 is maintained. Therefore, the movable film portion 82 is elastically deformed as pressure fluctuations are generated in the pressure receiving chamber 50. In particular, since the pressure fluctuation in the pressure receiving chamber 50 is small, the movable film portion 82 is effectively elastically deformed without contacting the inner surface of the recess 84.

  That is, when high frequency small amplitude vibration is input, the orifice passage 54 tuned to a lower frequency range than that has a significantly increased fluid flow resistance due to antiresonant action, and is substantially closed. However, the hydraulic pressure absorption function due to the elastic deformation of the movable film portion 82 works, and the pressure fluctuation in the pressure receiving chamber 50 is absorbed, so that a significantly high dynamic spring due to the substantial blockage of the orifice passage 54 is achieved. It will be avoided. Therefore, a good anti-vibration effect (vibration insulation effect based on low dynamic spring characteristics) against high-frequency small-amplitude vibration is exhibited.

  As is clear from the above description, in this embodiment, the hydraulic pressure absorption mechanism that absorbs pressure fluctuations in the pressure receiving chamber 50 includes the movable film portion 82 and the space 92 of the diaphragm 38 and is movable. A deformation amount limiting mechanism for the movable film portion 82 is configured including the inner surface of the recess 84 with which the film portion 82 is brought into contact. Further, the valve body with a built-in hydraulic pressure absorbing mechanism that opens and closes the through hole 30 by the operation of the pneumatic actuator 58 includes the movable film portion 82, the space 92, and the output fitting 62.

(3) Anti-vibration effect against idling vibration When a medium frequency medium amplitude vibration such as idling vibration higher than the tuning frequency of the orifice passage 54 is input, a pressure fluctuation with a certain amplitude is induced in the pressure receiving chamber 50. It becomes. At that time, as in the case of (2), the orifice passage 54 is substantially closed due to a significantly increased fluid flow resistance due to an anti-resonant action.

  When the idling vibration is input, the air pressure control circuit is switched and controlled so that the regulated air chamber 70 is connected to the negative pressure source 81. This switching control is realized, for example, by switching the switching valve 80 after confirming that the vehicle is in the idling state by the vehicle speed signal, gear signal (neutral or parking) and engine rotation signal. When the regulated air chamber 70 is connected to the negative pressure source 81 in this way, the outer peripheral portion of the movable film portion 82 of the diaphragm 38 is against the peripheral edge of the through hole 30 of the partition member 24 against the urging force of the coil spring 72. The pressure receiving chamber 50 and the equilibrium chamber 52 are in communication with each other through the through hole 30. In short, the negative pressure driving force exerted on the regulated air chamber 70 in the idling state is adjusted so that the output fitting 62 can be displaced below the mount center axis with a force larger than the biasing force by the coil spring 72. .

  As a result, the partition between the pressure receiving chamber 50 and the equilibrium chamber 52 is released to substantially become one fluid chamber 48, and the pressure fluctuation of the fluid chamber 48 based on the elastic deformation of the main rubber elastic body 16 causes the elastic deformation of the diaphragm 38. To be absorbed. Therefore, an effective anti-vibration effect (vibration insulation effect based on low dynamic spring characteristics) against idling vibration can be exhibited. In short, the integral fluid-filled region (fluid chamber 48) that is expressed in a state where the pressure-receiving chamber 50 and the equilibrium chamber 52 are communicated with each other through the through-hole 30 is configured such that a part of the wall portion is configured by the diaphragm 38. This allows volume changes to be easily tolerated so that it can function as a substantially single large equilibrium chamber.

  Here, the through-hole 30 does not separate the pressure receiving chamber 50 and the equilibrium chamber 52, and resonance of the fluid that is caused to flow through the through-hole 30 at the time of input of vibration to be vibrated, specifically, at the time of input of idling vibration. It is formed with a sufficiently large opening area so that adverse effects due to the action do not occur. More specifically, at the time of vibration input in a frequency range of at least 50 Hz or less, more preferably 100 Hz or less, the fluid that is caused to flow through the through-hole 30 is not balanced with the pressure receiving chamber 50 without causing a resonance phenomenon or the like. The through-hole 30 is formed with a large opening area and a small length so that an integrated pressure fluctuation with substantially no phase difference is induced with respect to the chamber 52. Thus, at the time of idling vibration input, the low dynamic spring characteristic as if by only the spring characteristic of the main rubber elastic body 16 is effectively exhibited without substantially containing the sealed fluid. .

  Therefore, in the automobile engine mount 10 having the above-described structure, the movable body of the diaphragm 38 in which the valve body that opens and closes the through hole 30 by the operation of the pneumatic actuator 58 is pressed against the partition member 24 by the output fitting 62. Structure having a built-in hydraulic pressure absorbing mechanism with a deformation amount limiting mechanism that allows elastic deformation of the portion 82 into the recess 84 and limits the amount of elastic deformation by contacting the inner surface of the movable film portion 82 with the recess 84 Therefore, while achieving compactness as a whole, low-frequency large-amplitude vibrations such as engine shake during driving of automobiles, high-frequency small-amplitude vibrations such as running-over noise, idling vibrations when the automobile stops, etc. A high level of anti-vibration performance can be exhibited against a plurality of vibrations having different frequency ranges and amplitudes, such as medium frequency medium amplitude vibrations.

  Further, in the present embodiment, the flange-like portion 76 of the housing bracket 60 of the pneumatic actuator 58 is not caulked and fixed to the caulking portion 20 of the second mounting bracket 14 together with the outer peripheral portion of the partition member 24, and the lower end of the caulking portion 20. Since the structure abutted on the portion facilitates the assembling work, it is not necessary to enlarge the caulking portion 20 to the extent that the flange-like portion 76 is caulked and fixed. Further downsizing can be achieved.

  Furthermore, in the present embodiment, the outer peripheral portion of the movable film portion 82 has a similar arcuate curved cross-sectional shape in a state where the through hole 30 is closed by the movable film portion 82 of the diaphragm 38. The abutting support portion 32 and the outer peripheral portion 86 of the output metal fitting 62 are supported by pressing. As a result, it is possible to effectively apply the clamping pressure to the outer peripheral portion of the movable film portion 86, and the closing performance of the through hole 30 by the movable film portion 82 is improved, and the pressure of the pressure receiving chamber 50 through the through hole 30 is improved. Leakage is more effectively suppressed.

  Furthermore, since the outer peripheral portion 86 of the output metal fitting 62 comes into contact with the movable film portion 82 via the elastic pressing projection 88, the durability performance of the movable film portion 82 can be improved.

  In the present embodiment, the through-hole 30 is closed by the movable film portion 82 of the diaphragm 38 and the opening of the recess 84 is covered with the movable film portion 82. The elastic pressing protrusion due to air remaining in the internal space 92 by being communicated with the external space through the communication groove 90 formed in the elastic pressing protrusion 88 and the through hole 94 formed in the housing fitting 60. The generation of abnormal noise during contact or separation of the movable film 88 with the movable film portion 82 is preferably suppressed.

  As mentioned above, although one embodiment of the present invention has been described in detail, the present invention is not limited in any way by the specific description in the embodiment, and various changes, modifications, and modifications based on the knowledge of those skilled in the art. Needless to say, the present invention can be implemented in a mode with improvements and the like, and all such modes are included in the scope of the present invention without departing from the gist of the present invention.

  For example, the shapes of the movable film portion 82, the output metal fitting 62, the recess 84, the partition member 24, the orifice member 28, the through hole 30, and the like are not limited to those illustrated.

  In the above-described embodiment, the movable film portion 82 has a substantially constant thickness dimension over substantially the whole. However, the movable film portion 82 is provided with the movable film portion 82 according to required deformation characteristics, vibration proof characteristics, manufacturability, or the like. Irregularities may be formed. In particular, in the movable film portion 82, at least one of the annular pressing portions (outer peripheral portions) pressed by the output fitting 62 of the pneumatic actuator 58 against the opening peripheral portion (contact support portion 32) of the through hole 30 in the partition member 24. A plurality of irregularities may be provided in the circumferential direction on the surface. As a result, when the annular pressing portion comes into contact with the peripheral portion of the through hole 30 or the output fitting 62, the area of the contact portion is reduced, and the generation of abnormal noise due to contact or separation is suppressed. is there.

  In addition, in the above-described embodiments, specific examples of applying the present invention to the engine mount 10 for automobiles have been described. However, the present invention can prevent various vibration bodies other than automobiles other than automobile body mounts and differential mounts. Any of the vibration mounts can be applied.

It is a longitudinal cross-sectional view which shows the engine mount for motor vehicles as one Embodiment of this invention, Comprising: The figure equivalent to the II cross section of FIG. The top view of the integral vulcanization molding product of the elastic rubber layer provided with the output metal fitting which constitutes a part of engine mount for the vehicles. The longitudinal cross-sectional view which expands and shows the operating state of the engine mount for the said motor vehicles. The longitudinal cross-sectional view which expands and shows another one operating form of the engine mount for the said motor vehicles.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Engine mount for motor vehicles, 12: 1st attachment metal fitting, 14: 2nd attachment metal fitting, 16: Main body rubber elastic body, 24: Partition member, 30: Through-hole, 32: Abutting support part, 38: Diaphragm 48: Fluid chamber, 50: Pressure receiving chamber, 52: Equilibrium chamber, 54: Orifice passage, 58: Pneumatic actuator, 60: Housing fitting, 62: Output fitting, 72: Coil spring, 82: Movable membrane part, 84: Recess, 92: space

Claims (7)

The first mounting member is spaced apart on the one opening side in the axial direction of the second mounting member having a cylindrical shape, and the first mounting member and the second mounting member are connected by the main rubber elastic body. A fluid in which an incompressible fluid is sealed between the main rubber elastic body and the flexible rubber film by covering the other opening in the axial direction of the second mounting member with a flexible rubber film. Forming a chamber, partitioning the fluid chamber with a partition member supported by the second mounting member, and forming part of the wall portion on both sides of the partition member in the fluid chamber with the main rubber elastic body A fluid-filled vibration isolator having an orifice passage that forms a balanced chamber in which a part of the pressure receiving chamber and a wall portion are formed of the flexible rubber film and communicates the pressure receiving chamber and the balanced chamber with each other In
An opening window that connects the pressure receiving chamber and the equilibrium chamber to each other to form one liquid chamber is provided in a central portion of the partition member, and on the opposite side to the equilibrium chamber with the flexible rubber film interposed therebetween. An actuator is disposed so that the distal end surface of the rigid output member in the pneumatic actuator is positioned opposite to the opening window with the flexible rubber film interposed therebetween, and the central portion of the flexible rubber film is divided into the partition The pneumatic actuator is provided with urging means for holding the opening window in a closed state by being pressed against the peripheral edge of the opening window of the member, and a recess is formed in the front end surface of the output member to The flexible rubber film is allowed to elastically deform into the recess of the flexible rubber film pressed against the partition member by a member, and the flexible rubber film is brought into contact with the inner surface of the recess. Deformation Limiting Mechanism for Limiting Elastic Deformation of Steel By configuring the Kino hydraulic absorbing mechanism, the fluid filled type vibration damping device, characterized in that a fluid pressure absorbing mechanism built-valve body for opening and closing the opening window by the operation of the air pressure actuator.   The orifice passage is tuned to a low frequency range corresponding to an engine shake, and the vibration having a high frequency and a small amplitude corresponding to a traveling booming noise is obtained in a state where the opening window is closed by the valve body with a built-in hydraulic pressure absorption mechanism. When the input is performed, the amount of deformation is such that the flexible rubber film does not come into contact with the inner surface of the recess. On the other hand, when the vibration is input at a low frequency and a large amplitude corresponding to an engine shake, the flexible rubber film is not deformed. The engine mount for automobiles is configured by setting the elasticity of the flexible rubber film and the size of the recess constituting the valve body with a built-in hydraulic pressure absorption mechanism so that the deformation amount comes into contact with the inner surface. The fluid-filled vibration isolator according to claim 1.   The hydraulic pressure is absorbed from the opening window of the partition member against the urging force of the urging means by applying a negative pressure to the pneumatic actuator in a stationary state of the automobile connected to the pneumatic actuator. The mechanism-equipped valve body is held in a separated state to open the opening window, while the pneumatic actuator is communicated with the atmosphere while the automobile is running, so that the partition is based on the urging force of the urging means. 3. The fluid filled type vibration damping device according to claim 2, further comprising air pressure control means for holding the valve body with a built-in hydraulic pressure absorption mechanism pressed against the opening window of the member to block the opening window.   The valve body with a built-in hydraulic pressure absorption mechanism is formed with an air communication path that allows the internal space of the recess, which is covered with the flexible rubber film, to communicate with the external space with the opening window closed. The fluid-filled vibration isolator according to any one of claims 1 to 3.   The output member of the pneumatic actuator is provided with an annular elastic pressing protrusion at the outer peripheral portion of the distal end surface, and the output member causes the flexible rubber film to open the flexible rubber film by the elastic pressing protrusion. The elastic pressing projection is provided with a communication groove in at least one place on the circumference, and the air communication path is formed by the communication groove. The fluid-filled vibration isolator according to claim 4.   The flexible rubber film has a plurality of irregularities in the circumferential direction on at least one surface of an annular pressing portion that is pressed by the output member of the pneumatic actuator against an opening peripheral portion of the opening window in the partition member. The fluid-filled type vibration damping device according to claim 1, wherein the fluid-filled type vibration damping device is provided.   An outer peripheral portion of the front end surface of the output member in the pneumatic actuator, and an opening peripheral portion of the opening window of the partition member against which the flexible rubber film is pressed by the outer peripheral portion of the front end surface of the output member, The fluid-filled vibration isolator according to any one of claims 1 to 6, wherein the fluid-filled vibration isolator is an abutting and clamping surface extending in the circumferential direction with arcuate curved cross-sectional shapes that are similar to each other with the flexible rubber film interposed therebetween. .

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