JP2011133031A - Fluid seal type vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid seal type vibration control device in a simple and compact structure, which exhibits excellent vibration control performance in any of three frequency zones different from one another, without requiring an actuator-driven change-over valve or the like. <P>SOLUTION: The radial-directional intermediate portion of a rubber elastic plate 32 is clamped in the plate thickness direction and is positioned radial-directionally to be supported, by a partitioning member 22 for partitioning a pressure receiving chamber 76 and a balancing chamber 78 communicated with each other through the first orifice passage 80, a liquid pressure absorbing mechanism 86 is constituted in the central part 64 on the inner circumferential side of an annular support part, and the second orifice passage 84 extended to be turned in around an outer circumferential portion 68 is formed by storage-positioning the outer circumferential portion 68 in an outer circumferential side of the annular support part, in an annular storage part 60 of the partitioning member 22. Thereby, a vibration control effect against low-frequency vibration is obtained by the first orifice passage 80, a vibration control effect against medium-frequency vibration is obtained by the second orifice passage 84, and a vibration control effect against high-frequency vibration is obtained by the liquid pressure absorbing mechanism 86. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an anti-vibration device used as, for example, an automobile engine mount and the like, and more particularly, a fluid-filled anti-vibration device that obtains an anti-vibration effect by utilizing the flow action of an incompressible fluid enclosed therein. It is about.

  Conventionally, as a kind of anti-vibration coupling body and anti-vibration support body mounted between members constituting the vibration transmission system, in addition to the anti-vibration effect of the rubber elastic body, the resonance action of the enclosed incompressible fluid has been used. Thus, there is known a fluid-filled vibration isolator that obtains a vibration isolating effect. Such a vibration isolator is generally a vibration isolator in which a first mounting member and a second mounting member are connected by a main rubber elastic body, and a pressure receiving portion in which a part of a wall portion is configured by the main rubber elastic body. A chamber and an equilibrium chamber in which a part of the wall portion is formed of an easily deformable flexible film are provided, and an incompressible fluid is enclosed in the pressure receiving chamber and the equilibrium chamber. The pressure receiving chamber and the equilibrium chamber are communicated with each other based on a relative pressure fluctuation caused between the pressure receiving chamber and the equilibrium chamber when vibration is input between the first mounting member and the second mounting member. An anti-vibration effect is obtained by utilizing the resonance action of the fluid that is caused to flow through the orifice passage.

  By the way, the anti-vibration effect based on the resonance action of the incompressible fluid that is caused to flow through the orifice passage can hardly be exhibited effectively only in a specific frequency range that has been tuned in advance. In particular, a decrease in vibration-proof performance due to the high dynamic spring at the time of vibration input in a frequency range higher than the tuning frequency of the orifice passage tends to be a problem. Therefore, the applicant of the present invention previously disclosed in Japanese Patent Application Laid-Open No. 2006-97824 (Patent Document 1) uses a movable rubber plate supported by a partition member that partitions the pressure receiving chamber and the equilibrium chamber, thereby preventing vibration at high frequencies. A structure with improved performance was proposed.

  However, in the fluid-filled vibration isolator proposed in Patent Document 1 described above, by adopting a movable rubber plate having a specific shape, the orifice passage is suppressed while suppressing the contact sound of the rubber elastic plate against the partition member. Although the reduction of the dynamic spring in the frequency range higher than the tuning frequency can be reduced to some extent, depending on the required anti-vibration characteristics, it is still not sufficient. For example, in automobile engine mounts, in addition to low-frequency large-amplitude vibrations such as shake vibrations and medium-frequency medium-amplitude vibrations such as idling vibrations, advanced anti-vibration methods are also provided for high-frequency small-amplitude vibrations such as running noise. When performance is required, it has been difficult to achieve sufficient anti-vibration performance against vibrations in these three different frequency ranges.

  In order to realize excellent anti-vibration performance against vibrations in these three frequency ranges, for example, three orifice passages that are individually tuned are formed, and a switching valve that switches the three orifice passages is provided. However, this requires an actuator for switching the switching valve, which complicates the structure and increases the size and weight of the apparatus.

JP 2006-97824 A

  The present invention has been made in the background as described above, and the problem to be solved is a fluid-filled vibration proofing that can exhibit excellent vibration proofing performance against vibrations in three frequency ranges. An object of the present invention is to realize a device with a simple and compact structure without requiring a switching valve or the like driven by an actuator.

  A feature of the present invention is that (a) a pressure receiving chamber in which a first mounting member and a second mounting member are connected by a main rubber elastic body, and a part of the wall portion is configured by the main rubber elastic body; , Forming equilibrium chambers with part of the wall made of a flexible membrane on both sides of the partition member supported by the second mounting member, so that the pressure receiving chamber and the equilibrium chamber are incompressible In a fluid-filled vibration isolator that encloses a fluid and forms a first orifice passage that communicates the pressure receiving chamber and the equilibrium chamber, (b) the front and back surfaces of the intermediate portion in the radial direction with respect to the disc-shaped rubber elastic plate An annular seal lip that protrudes on both sides and extends in the circumferential direction is integrally formed, and the annular seal lip of the rubber elastic plate is sandwiched from both the front and back sides and supported in a radial direction by the partition member, and is supported by the partition member. The pressure in the pressure receiving chamber and the equilibrium chamber is controlled through the through hole provided. The hydraulic pressure absorbing mechanism is configured so as to be exerted on each surface of the central portion surrounded by the annular seal lip of the elastic plate, while (c) annular on the outer peripheral side of the annular seal lip in the rubber elastic plate A thin-walled portion is formed, and an outer peripheral portion of the rubber elastic plate positioned radially outward of the annular thin-walled portion is curved in a plate thickness direction, and the outer periphery of the rubber elastic plate in the partition member Forming an annular accommodating portion for accommodating the portion, and communicating the annular accommodating portion with the pressure receiving chamber and the equilibrium chamber through a communication hole provided in the annular accommodating portion; The fluid-filled vibration isolator has a second orifice passage that goes around the outer peripheral portion and communicates the pressure receiving chamber and the equilibrium chamber.

  In such a fluid-filled vibration isolator having a structure according to the present invention, a rubber elastic plate having a specific structure is adopted, and an annular seal lip formed at a radially intermediate portion of the rubber elastic plate is sandwiched between partition members. Locked and supported in the radial direction. As a result, the rubber elastic plate is supported in a state in which the rubber elastic plate is fluid-tightly sealed over the entire circumference by the partition member at the radial intermediate portion thereof, and (ii) the diameter by the partition member. It is supported in a state positioned in the direction. As a result, the fluid pressure absorption mechanism that uses the central portion of the rubber elastic plate and the second orifice passage that uses the outer peripheral portion of the rubber elastic plate prevent fluid leakage or short circuit between them, In addition, each single rubber elastic plate can be skillfully used to be configured separately. In addition, since the intermediate portion in the radial direction of the rubber elastic body is positioned in the radial direction using the annular seal lip and assembled to the partition member, it is formed around the outer peripheral portion of the rubber elastic plate in the annular accommodating portion. The passage section of the second orifice passage thus made can be set stably and accurately, and the intended vibration-proofing effect by the second orifice passage can be stably exhibited.

  Therefore, in the fluid-filled vibration isolator according to the present invention, in addition to exhibiting the vibration isolating performance in the low frequency range by the first orifice passage, the second frequency also in the middle frequency range and the high frequency range. The anti-vibration effect by the orifice passage and the anti-vibration effect by the hydraulic pressure absorption mechanism can be exhibited effectively.

  Moreover, in the second orifice passage, the fluid flow amount is limited by displacing or constricting the communication hole opened in the annular housing portion by displacing the outer peripheral portion of the rubber elastic plate when large amplitude vibration is input, The amount of fluid flow through the first orifice passage at the time of inputting the low frequency large amplitude vibration can be ensured, and the vibration isolation performance by the first orifice passage can be sufficiently exhibited. Also, in the hydraulic pressure absorption mechanism, the amount of elastic deformation of the central part of the rubber elastic plate is limited by its own elasticity etc. when medium to large amplitude vibration is input, so low frequency large amplitude vibration and medium frequency medium amplitude vibration The amount of fluid flow through the first orifice passage and the second orifice passage at the time of the input can be ensured, and the vibration-proof performance by the first orifice passage and the second orifice passage can be sufficiently exhibited.

  Therefore, according to the present invention, there is no need for a switching valve for switching the orifice passage, an actuator for operating the orifice passage, etc., and a simple and compact structure, and vibrations in three different frequency ranges as described above. In contrast, a fluid-filled vibration isolator capable of exhibiting an excellent vibration isolating effect can be realized.

  By the way, in the fluid filled type vibration damping device according to the present invention, for example, at the inner peripheral edge portion and the outer peripheral edge portion of the outer peripheral portion of the rubber elastic plate, buffer protrusions that protrude on both the front and back surfaces and extend in the circumferential direction are integrally formed. Embodiments may be employed.

  By providing such a buffering protrusion, the impact on the inner surface of the annular housing portion is further reduced, and the cover hole or constriction of the communication hole at the time of inputting the large amplitude vibration as described above can be expressed more stably. .

  Further, when forming such buffer protrusions, in the initial state where no vibration is input, the buffer protrusions respectively formed on the inner peripheral edge portion and the outer peripheral edge portion of the front and back surfaces of the outer peripheral portion of the rubber elastic plate are used. In any case, it is more preferable that the inner surface of the annular housing portion is set so as to be in contact with at least the top portion of the outer circumferential portion that undulates in the circumferential direction.

  In this way, by making the buffer protrusion contact the inner surface of the annular housing portion in the initial state, the impact of the rubber elastic plate against the inner surface of the annular housing portion during vibration input can be further effectively reduced.

  Further, in the fluid filled type vibration damping device according to the present invention, for example, in the partition member, at least one of the annular seal lips formed on both the front and back surfaces of the rubber elastic plate is in contact with the inner peripheral surface in the radial direction. The aspect which formed the latching protrusion latched in the state which controls the displacement to an inward is employ | adopted suitably.

  That is, in the present invention, the radially inward intermediate portion of the rubber elastic plate is regulated in the radially inward displacement with respect to the partition member based on the locking action of the partition member with the annular seal lip formed therein. . Therefore, for example, when excessive pressure is applied to the central part of the rubber elastic plate due to cavitation occurring in the pressure receiving chamber due to input of shocking heavy load vibration when climbing over a step or cranking, etc. Even if it is etc., malfunctions, such as the support position of the rubber elastic board by a partition member shifting, are prevented effectively. As a result, the anti-vibration effect exhibited by the above-described hydraulic pressure absorbing mechanism and the second orifice passage configured using the central portion and the outer peripheral portion of the rubber elastic plate are both more stable and more stable. It is demonstrated.

  In the fluid-filled vibration isolator according to the present invention, for example, at least one of a through hole that exerts a pressure in the pressure receiving chamber and a through hole that exerts a pressure in the equilibrium chamber with respect to the central portion of the rubber elastic plate Thus, a mode in which a third orifice passage tuned in a higher frequency range than any of the first orifice passage and the second orifice passage is formed is preferably employed.

  By forming such a third orifice passage, it is possible to more effectively obtain a vibration-proofing effect against high-frequency vibration exhibited by the hydraulic pressure absorbing mechanism in a more specific frequency range.

  Furthermore, in the fluid filled type vibration damping device according to the present invention, for example, a mode in which the first orifice passage is formed in the partition member so as to extend in the circumferential direction on the outer circumferential side from the annular housing portion is preferably employed. Is done.

  In such an aspect, the flow path length of the first orifice passage can be ensured efficiently, tuning to the low frequency range can be easily performed, and the cross-sectional area of the flow path can be secured and prevented. The vibration characteristics can be further improved. In addition, since the first orifice passage can be formed so as to be overlapped at substantially the same position in the axial direction so as to be arranged on the outer peripheral side of the rubber elastic plate and the annular housing portion, the vibration isolator as a whole It is also possible to reduce the axial size.

  In the fluid-filled vibration isolator constructed according to the present invention, the central portion of the rubber elastic body is utilized by supporting the radially intermediate portion of the rubber elastic plate having a specific structure in the seal positioning state by the partition member. The anti-vibration effect in the high frequency range by the hydraulic pressure absorption mechanism constructed in the same way, and the anti-vibration effect in the mid-frequency range by the second orifice passage that uses the outer periphery of the rubber elastic body It was possible to make it possible to achieve both of them.

  As a result, the fluid filled type vibration damping device of the present invention does not require a switching valve for switching the orifice passage or an actuator for operating the same, and has a simple and compact structure with three different frequency ranges. All of them were able to stably achieve excellent vibration isolation performance with high reliability against vibration.

The longitudinal cross-sectional view equivalent to the II cross section in FIG. 2 which shows the engine mount as one Embodiment of this invention. The bottom view of the engine mount shown in FIG. The top view of the partition member which comprises the engine mount shown in FIG. IV-IV sectional drawing in FIG. FIG. 4 is an exploded perspective view of the partition member shown in FIG. 3 from obliquely below. The disassembled perspective view from diagonally upward of the partition member shown in FIG. The top view of the orifice member which comprises the partition member shown in FIG. The bottom view of the partition member shown in FIG. IX-IX sectional drawing in FIG. Expansive explanatory drawing of the XX cross section in FIG. FIG. 4 is a plan view of a lid plate metal fitting constituting the partition member shown in FIG. 3. XII-XII sectional drawing in FIG. The top view of the rubber elastic board which comprises the partition member shown in FIG. XIV-XIV sectional drawing in FIG. Expansive explanatory drawing of the left end in FIG. Explanatory drawing of the outer periphery end surface in area | region (alpha) of the rubber elastic board shown by FIG. The graph which shows the low frequency vibration proof characteristic of the engine mount shown in FIG. The graph which shows the medium frequency vibration proof characteristic of the engine mount shown in FIG. The graph which shows the high frequency vibration proof characteristic of the engine mount shown in FIG.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show a fluid-filled engine mount 10 for an automobile as an embodiment of a fluid-filled vibration isolator according to the present invention. The engine mount 10 includes a first mounting bracket 14 as a first mounting member and a second mounting bracket 16 as a second mounting member, which are elastically connected by a main rubber elastic body 12. The power unit attached to the metal fitting 14 is elastically supported in a suspended state with respect to the vehicle body attached to the second attachment metal fitting 16. Note that FIG. 1 shows a state in which the external force is not applied, and is attached to the vehicle such that the vertical direction in FIG. 1 is a substantially vertical vertical direction.

  More specifically, the first mounting member 14 has a structure in which a nut member 20 protruding downward is welded to the bottom wall of the cup member 18 that opens upward. On the other hand, the second mounting bracket 16 has a large-diameter, generally cylindrical shape, and is arranged on the outer periphery of the first mounting bracket 14 so as to be spaced apart. The main rubber elastic body 12 has a thick, generally tapered cylindrical shape or a hollow truncated cone shape, and its inner peripheral surface is vulcanized and bonded to the outer peripheral surface of the first mounting bracket 14, The outer peripheral surface is vulcanized and bonded to the inner peripheral surface of the second mounting bracket 16. As a result, the main rubber elastic body 12 is disposed between the upper end in the axial direction of the first mounting bracket 14 and the lower end in the axial direction of the second mounting bracket 16.

  That is, in the present embodiment, the main rubber elastic body 12 is formed as an integrally vulcanized molded product including the first mounting bracket 14 and the second mounting bracket 16, and the lower side of the second mounting bracket 16. The opening is covered fluid-tightly by the main rubber elastic body 12 and the first mounting bracket 14.

  On the other hand, the partition member 22 and the diaphragm 24 are assembled in the upper opening of the second mounting bracket 16 so as to overlap each other.

  The diaphragm 24 is formed of a thin rubber elastic film so as to be easily elastically deformed with a predetermined slack. Further, an annular fixing metal fitting 26 is vulcanized and bonded to the outer peripheral edge of the diaphragm 24. The fixing bracket 26 is caulked and fixed to the upper opening of the second mounting bracket 16 so that the upper opening of the second mounting bracket 16 is covered with a diaphragm 24 in a fluid-tight manner.

  Thereby, the space between the opposing surfaces of the main rubber elastic body 12 and the diaphragm 24 that covers the openings on both sides in the axial direction of the second mounting bracket 16 is isolated from the external space in a fluid-tight manner, and is incompressible there. A fluid chamber in which a fluid is enclosed is formed. This fluid chamber is filled with incompressible fluid such as water or alkylene glycol.

  On the other hand, as shown in FIGS. 3 to 6, the partition member 22 has a cover plate metal 30 superimposed on the lower surface of the orifice member 28, and a rubber between the orifice member 28 and the cover plate metal 30. The elastic plate 32 is assembled so as to be sandwiched.

  As shown in FIGS. 7 to 10, the orifice member 28 has a thick, substantially annular plate shape, and a large-diameter upper through hole 33 is provided at the center thereof. An outer peripheral wall 34 is formed integrally with the outer peripheral edge. A partition wall 36 projects from the outer peripheral surface of the outer peripheral wall portion 34 at one location on the periphery, and a notch window 38 is formed on one side in the circumferential direction of the partition wall 36. ing. Furthermore, an annular recess 40 extending in the circumferential direction is formed on the lower surface of the orifice member 28, and the annular recess 40 opens on the lower surface and the inner peripheral surface of the orifice member 28. A plurality of upper communication holes 44 are formed in the upper bottom portion 42 of the annular recess 40, and the inner peripheral edge of the upper bottom portion 42 is locked to protrude downward into the annular recess 40. A protrusion 46 is formed. In the present embodiment, the locking projections 46 have an annular shape extending continuously in the circumferential direction, but may be divided in the circumferential direction.

  On the other hand, as shown in FIGS. 11 to 12, the lid plate metal fitting 30 has a thin, generally annular plate shape, and has a lower transparent portion having a smaller diameter than the upper through hole 33 at the center thereof. A hole 48 is provided. An annular step 50 protruding downward from the lid plate 30 is formed on the outer peripheral side of the lower through-hole 48, and the outer diameter of the annular step 50 is determined by the upper through-hole of the orifice member 28. The inner diameter of 33 is substantially the same. A cylindrical portion 52 that protrudes downward from the inner peripheral edge of the annular stepped portion 50 is formed, and the lower through-hole 48 described above is formed by the inner hole of the cylindrical portion 52. Note that a plurality of lower communication holes 54 are formed in the radial intermediate portion of the cover plate metal fitting 30 (a position where the annular stepped portion 50 is displaced to the outer peripheral side). Further, the outer diameter dimension of the lid plate metal 30 is larger than the outer diameter dimension of the orifice member 28. In the present embodiment, the inner diameter of the upper through-hole 33 is larger than the inner diameter of the lower through-hole 48, but the relationship between the diameters of the upper through-hole 33 and the lower through-hole 48 is an object. You may tune suitably according to a vibration proof characteristic. That is, the inner diameter of the upper through-hole 33 may be smaller than the inner diameter of the lower through-hole 48, or the inner diameter of the upper through-hole 33 and the lower through-hole 48 may be made equal. However, the inner diameter dimensions of the upper and lower through holes 33 and 48 are made smaller than the inner diameter dimension of the annular seal lip 62 so that the annular seal lip 62 described later can be sealed.

  And this cover plate metal fitting 30 is piled up from the lower part on the same central axis with respect to the orifice member 28, and it fixes using the fixing holes 56 and 57 provided in each corresponding position of a radial direction intermediate part. They are fixed to each other with screws 58 or the like. And the opening part to the lower surface in the annular recess 40 of the orifice member 28 is covered with the cover plate metal fitting 30, thereby forming the annular housing part 60 that opens toward the inner peripheral side in the partition member 22. Yes.

  Further, the rubber elastic plate 32 is disposed between the overlapping surfaces of the orifice member 28 and the cover plate fitting 30 in the central portion thereof. As shown in FIGS. 13 to 16, the rubber elastic plate 32 has a substantially disk shape, and its outer diameter dimension is the outer peripheral wall of the annular recess 40 formed in the orifice member 28. The inner diameter dimension of the portion is made smaller by a predetermined dimension. The rubber elastic plate 32 is assembled by accommodating a predetermined width region on the outer periphery thereof in the annular recess 40 and sandwiching and supporting the orifice member 28 and the cover plate metal fitting 30.

  Also, the rubber elastic plate 32 is formed with annular seal lips 62, 62 that protrude from both the upper and lower surfaces and extend continuously over the entire circumference in the circumferential direction in the intermediate portion in the radial direction. The projecting tip portions of the upper and lower annular seal lips 62, 62 are pressed against the upper and lower opposing surfaces of the orifice member 28 and the lid plate metal 30 that define the annular accommodating portion 60. The plate 32 is sandwiched and supported by the partition member 22 in the plate thickness direction at the radial intermediate portion where the annular seal lips 62, 62 are formed. That is, the rubber elastic plate 32 is housed and disposed in the annular housing portion 60 on the outer peripheral side of the formation site of the annular seal lips 62 and 62.

  In addition, the annular seal lip 62 on the upper side of the rubber elastic plate 32 is engaged in a radial direction with an engaging projection 46 protruding from the peripheral edge of the opening of the annular accommodating portion 60. The upper annular seal lip 62 is assembled with the engaging projection 46 of the annular accommodating portion 60 in an externally fitted state, and thereby the annular seal lip 62 and then the rubber with respect to the orifice member 28 and the cover plate metal fitting 30. The elastic plate 32 is positioned on the same central axis while preventing relative displacement in the radial direction. That is, when the inner peripheral surface of the upper annular seal lip 62 abuts against the locking projection 46, the rubber elastic plate 32 is locked in the radial direction, and the rubber elastic plate 32 is displaced radially inward. Being regulated.

  The central portion 64 located on the inner peripheral side of the annular elastic lip 62 in the rubber elastic plate 32 is exposed to the outside through the upper through hole 33 of the orifice member 28 at the central portion of the partition member 22. . On the other hand, the lower surface of the central portion 64 is covered with the annular step portion 50 of the lid plate metal 30, but is separated from the annular step portion 50. Accordingly, the central portion 64 of the rubber elastic plate 32 is assembled in a state in which elastic deformation in the thickness direction is allowed without being restricted by either the orifice member 28 or the cover plate metal fitting 30. In the present embodiment, the central portion 64 is further composed of a thick disc-shaped central portion and a thinner annular outer peripheral portion, and is appropriate for both the upper and lower surfaces of the thick central portion. The spring characteristics are adjusted by forming the rib protrusions having various shapes.

  Further, the rubber elastic plate 32 is formed with an annular thin portion 66 adjacent to the outer peripheral sides of the upper and lower annular seal lips 62, 62 and extending annularly in the circumferential direction. The annular thin portion 66 is thinned so as to be rolled from both the upper and lower (front and back) surfaces of the rubber elastic plate 32, and the rubber elastic plate 32 is the thinnest in the annular thin portion 66.

  In the rubber elastic plate 32, the outer peripheral portion 68 located on the outer peripheral side of the annular thin portion 66 is directed toward both sides in the thickness direction (vertical direction) based on elastic deformation such that the annular thin portion 66 is bent. It can be easily deformed and displaced in a swinging manner. The outer peripheral portion 68 has a thickness dimension that is smaller than the height dimension of the annular housing portion 60 throughout, and can be deformed and displaced in a swinging manner within the annular housing portion 60. Yes. Further, the outer peripheral portion 68 has a substantially trapezoidal cross-sectional shape that is gradually thinned from both sides in the thickness direction as going outward in the radial direction. In particular, in the present embodiment, buffer protrusions 70 and 72 are formed integrally on the inner peripheral edge and the outer peripheral edge of the outer peripheral portion 68 so as to protrude from both the front and back surfaces and extend in the circumferential direction.

  Thus, when the outer peripheral portion 68 is deformed and displaced in a swinging manner with the thin annular portion 66 as a fulcrum, only the outer peripheral portion does not come into contact with each other in the inner peripheral portion and the outer peripheral portion. The formed buffer protrusions 70 and 72 are brought into contact with the inner surface of the annular housing portion 60 at substantially the same time or slightly before and after.

  The outer peripheral portion 68 is formed in a shape that swells on both sides in the thickness direction in the circumferential direction, and extends in the circumferential direction in a corrugated shape. In other words, the outer peripheral portion 68 is constant so that the cross-sectional shape and size thereof are not substantially changed, and the center position in the thickness direction is changed so as to swing up and down in the circumferential direction. FIG. 16 is a development explanatory view of the outer peripheral end face of the rubber elastic plate 32 in the region α shown in FIG. In particular, in the present embodiment, as shown in FIG. 16, the center line and upper and lower surfaces of the outer peripheral portion 68 have a substantially sine wave shape that undulates in the circumferential direction at a constant cycle, and one cycle is 90 °. The upper and lower surfaces are curved surfaces that are smooth as a whole.

  And the outer peripheral part 68 of the rubber elastic board 32 is assembled | attached to the cyclic | annular accommodation part 60 in the accommodation state, and as FIG. 15 shows, the inner and outer buffer protrusions 70 and 72 in this outer peripheral part 68 are wavy undulations. 16 are in contact with the orifice member 28 at the center position in FIG. 16 which is the top dead center, while they are in contact with the lid plate 30 at both the left and right positions in FIG. It is touched. Further, at the top dead center of the wavy undulation, at least the outer peripheral buffer projection 72 is separated from the lid plate 30, while at the bottom dead center of the wavy undulation, at least the outer peripheral buffer projection 72 is separated from the orifice member 28. is doing. Furthermore, the outer peripheral surface of the outer peripheral portion 68 is opposed to the outer peripheral wall surface of the annular housing portion 60 at a predetermined distance in the radial direction, and is an annular shape that extends over the entire circumference radially outward of the outer peripheral portion 68. The communication gap 74 is formed.

  Further, an upper communication hole 44 formed in the orifice member 28 that is the upper side wall portion of the annular housing portion 60 and a lower communication hole 54 formed in the cover plate metal fitting 30 that is the lower side wall portion of the annular housing portion 60 are In any case, the outer peripheral portion 68 accommodated in the annular accommodating portion 60 is opened at the accommodating position. In particular, in the present embodiment, the upper and lower communication holes 44 and 54 are each formed with an opening at a position and a size that straddle both radial sides with the buffer protrusion 70 on the inner peripheral side interposed therebetween. Further, the annular housing portion 60 is communicated with an equilibrium chamber 78 and a pressure receiving chamber 76, which will be described later, through the upper and lower communication holes 44 and 54, respectively.

  Thus, as shown in FIG. 1, the partition member 22 having such a structure has the outer peripheral edge portion of the cover plate metal fitting 30 overlapped with the upper opening of the second mounting metal fitting 16. In addition, it is assembled by being caulked and fixed to the upper opening of the second mounting bracket 16 together with the outer peripheral edge portion of the fixing bracket 26 of the diaphragm 24. Under such an assembled state, the fixing member 26 of the diaphragm 24 is overlaid on the upper side of the orifice member 28, and the orifice member 28 is sandwiched between the cover plate member 30 and the fixing member 26.

  As a result, the fluid chamber formed between the opposing surfaces of the main rubber elastic body 12 and the diaphragm 24 is divided into two by the partition member 22, and a part of the wall portion below the partition member 22 has the main rubber elasticity. A pressure receiving chamber 76 constituted by the body 12 is formed. On the other hand, above the partition member 22, an equilibrium chamber 78 in which a part of the wall portion is configured by the diaphragm 24 is formed. That is, a pressure receiving chamber 76 and an equilibrium chamber 78 filled with an incompressible fluid are formed on both sides of the partition member 22 supported by the second mounting bracket 16. When mainly axial vibration is input between the first mounting bracket 14 and the second mounting bracket 16, pressure fluctuation occurs in the pressure receiving chamber 76 due to elastic deformation of the main rubber elastic body 12. It can be tightened. The equilibrium chamber 78 is easily allowed to change its volume based on the deformation of the diaphragm 24.

  Further, a first orifice passage 80 extending in the circumferential direction is formed on the outer peripheral side of the orifice member 28 by a region covered with the cover plate fitting 30 and the fixing fitting 26. The first orifice passage 80 is divided by a partition wall 36 projecting from the orifice member 28 at one place on the circumference, so that the length of the first orifice passage 80 is less than one round. The pressure receiving chamber 76 communicates with the pressure receiving chamber 76 through the through window 82 formed in the lid plate 30, and the other end communicates with the equilibrium chamber 78 through the cutout window 38 formed in the orifice member 28. As a result, the pressure receiving chamber 76 and the equilibrium chamber 78 are communicated with each other by the first orifice passage 80, and an anti-vibration effect against low-frequency vibration is exhibited based on the resonance action of the fluid that flows through the first orifice passage 80. It has become so. In particular, in the present embodiment, the passage cross-sectional area and the passage length of the first orifice passage 80 are set so that a high damping effect is exhibited against a low-frequency large-amplitude vibration of about 10 Hz corresponding to an engine shake. Yes. Further, as shown in FIG. 1, the first orifice passage 80 surrounds the outer peripheral side of the annular housing portion 60 so as to overlap the rubber elastic plate 32 and the annular housing portion 60 at substantially the same position in the axial direction. It is formed to extend in the direction. Thereby, the flow path length of the 1st orifice channel | path 80 is fully ensured, suppressing the enlargement of the size in the axial direction of the engine mount 10. FIG.

  Furthermore, a second orifice passage 84 communicating with the pressure receiving chamber 76 and the equilibrium chamber 78 is also formed in the annular housing portion 60 of the partition member 22 independently from the first orifice passage 80. That is, the second orifice passage 84 has an upper communication hole 44 opened in the pressure receiving chamber 76 and a lower communication hole 54 opened in the equilibrium chamber 78 in the outer peripheral portion of the rubber elastic plate 32 in the annular housing portion 60. It is constituted by communicating with each other through a fluid passage (including a communication gap 74) formed by wrapping 68 around the outer peripheral side. Then, based on the resonance action of the fluid flowing through the second orifice passage 84, an anti-vibration effect against the medium frequency vibration is exhibited. In particular, in the present embodiment, the passage cross-sectional area and the passage length of the second orifice passage 84 are set so that a high damping effect is exhibited with respect to a medium frequency small amplitude vibration around 40 Hz corresponding to idling vibration. Yes.

  When a small amplitude of idling vibration is input, the fluid flows through the second orifice passage 84 having a small flow resistance. As a result, the escape of pressure through the first orifice passage 80 in the low frequency region where the flow resistance is large is suppressed, and the amount of fluid flow in the second orifice passage 84 is ensured, and the intended medium frequency vibration isolation effect is obtained. Effectively demonstrated. On the other hand, when an engine shake vibration is input, a vibration having a larger amplitude than that of the idling vibration is input. Therefore, the amount of swing deformation displacement of the outer peripheral portion 68 of the rubber elastic plate 32 is increased, and the inner surface of the annular housing portion 60 is And the communication holes 44 and 54 are covered so that the second orifice passage 84 is substantially cut off and pressure escape through the second orifice passage 84 is avoided. The fluid flow rate of the first orifice passage 80 is ensured and the intended low frequency vibration isolation effect is effectively exhibited.

  Furthermore, a hydraulic pressure absorbing mechanism 86 using the rubber elastic plate 32 is configured at the central portion of the partition member 22. That is, the pressure of one of the pressure receiving chamber 76 and the equilibrium chamber 78 is applied to the central portion 64 of the rubber elastic plate 32 through the lower through hole 48 and the upper through hole 33. Therefore, at the time of inputting high-frequency vibration such as traveling booming noise, not only the first orifice passage 80 but also the second orifice passage 84 has a significantly increased fluid flow resistance and is in a substantially cut-off state. The central portion 64 is elastically deformed by a large pressure fluctuation induced in the pressure receiving chamber 76, and the pressure fluctuation of the pressure receiving chamber 76 is released to the equilibrium chamber 78 by the elastic deformation, thereby improving the vibration isolation performance. It has become so.

  In particular, in the present embodiment, the lower through-hole 48 is formed with a specific flow path configuration including the cylindrical portion 52 on the fluid flow path generated on the pressure receiving chamber 76 side with the elastic deformation of the central portion 64 of the rubber elastic plate 32. Has been. Then, by appropriately setting the length and the cross-sectional area of the cylindrical portion 52, a vibration isolation effect based on the fluid resonance action is exerted with respect to vibration around 100 Hz corresponding to a traveling booming noise intended for vibration isolation. The resulting third orifice passage 88 is constituted by such a lower through-hole 48. That is, in the present embodiment, the third orifice passage 88 constituted by the lower through-hole 48 is tuned in a higher frequency region than any of the first and second orifice passages 80 and 84.

  The central portion 64 of the rubber elastic plate 32 is disposed in a stretched state with a sufficient thickness dimension, and has an appropriate size of deformation rigidity (dynamic spring constant). When the engine shake or idling vibration described above, which has a sufficiently large amplitude as compared with a traveling boom sound that is expected to have an anti-vibration effect by the central portion 64, pressure escape due to elastic deformation of the central portion 64 is prevented. It has become so. That is, the hydraulic pressure absorbing function by the elastic deformation of the central portion 64 does not substantially function for such vibrations such as an engine shake having a large amplitude. Therefore, each vibration isolation effect by the first and second orifice passages 80 and 84 can be effectively exhibited together with the vibration isolation effect by the third orifice passage 88.

  The rubber elastic plate 32 is sandwiched between the upper and lower seal lips 62, 62 projecting from the radially intermediate portion by the partition member 22, and the upper seal lip 62 has a diameter at the locking projection 46. By being locked in the direction, the radial displacement of the rubber elastic plate 32 with respect to the partition member 22 is firmly prevented. Thereby, the passage cross section in the second orifice passage 84 formed around the outer peripheral portion 68 of the rubber elastic plate 32 in the annular housing portion 60 of the partition member 22 can be set with excellent accuracy and stability. The target vibration-proofing effect is exhibited more stably and floats. In particular, in the present embodiment, since the upper seal lip 62 of the rubber elastic plate 32 is locked from the inner peripheral side by the locking projection 46, a shocking heavy load is applied, for example, during cranking, and cavitation. Even when an excessive pressure due to the above acts and the rubber elastic plate 32 bulges and deforms toward the pressure receiving chamber 76 or the equilibrium chamber 78, the positioning state of the intermediate portion in the radial direction of the rubber elastic plate 32 can be reliably maintained. Therefore, a problem that the outer peripheral portion 68 of the rubber elastic plate 32 is dragged out from the annular housing portion 60 can be prevented, and the reliability and performance stability can be further improved.

  Furthermore, in the present embodiment, the outer peripheral portion 68 of the rubber elastic plate 32 is partially in contact with the upper and lower inner surfaces of the annular housing portion 60 on the periphery from the beginning. Therefore, the elastic deformation displacement of the outer peripheral portion 68 at the time of vibration input causes the contact area to increase / decrease or repeat contact / separation to the inner surface of the annular housing portion 60 of the outer peripheral portion 68. Generation of impact and vibration associated with hitting can be effectively suppressed.

  Incidentally, the results of actual measurement of the anti-vibration characteristics of the prototype of the engine mount 10 having the structure according to the present embodiment are shown in FIGS. That is, it can be seen from the graph shown in FIG. 17 that the anti-vibration effect (high damping effect) by the first orifice passage 80 is effectively exhibited against low-frequency large-amplitude vibration corresponding to engine shake. Further, it can be seen from the graph shown in FIG. 18 that the anti-vibration effect (low dynamic spring effect) by the second orifice passage 84 is effectively exhibited against medium-frequency medium amplitude vibration corresponding to idling vibration. Further, from the graph shown in FIG. 19, the anti-vibration effect (low dynamic spring effect) by the hydraulic pressure absorbing mechanism 86 including the third orifice passage 88 is effectively exhibited against high-frequency small-amplitude vibration corresponding to traveling noise. It is recognized that

10: engine mount, 12: rubber elastic body, 14: first mounting bracket, 16: second mounting bracket, 22: partition member, 24: diaphragm, 26: fixing bracket, 28: orifice member, 30: lid Metal plate, 32: Rubber elastic plate, 33: Upper through hole, 34: Outer wall, 36: Partition wall, 38: Notch window, 40: Annular recess, 44: Upper communication hole, 46: Locking projection, 48 : Lower side through hole, 50: annular stepped part, 52: cylindrical part, 54: lower communication hole, 60: annular accommodating part, 62: seal lip, 64: central part, 66: annular thin part, 68: outer peripheral part , 70: buffer projection (inner circumference), 72: buffer projection (outer circumference), 74: communication gap, 76: pressure receiving chamber, 78: equilibrium chamber, 80: first orifice passage, 82: through window, 84: second Orifice passage, 86: hydraulic absorption mechanism, 88: third orifice A road

Claims (6)

The first mounting member and the second mounting member are connected by a main rubber elastic body, 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 is a flexible film. The formed equilibrium chambers are formed on both sides of the partition member supported by the second mounting member, and an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber, and the pressure receiving chamber and the equilibrium chamber In the fluid-filled vibration isolator that forms the first orifice passage communicating with
An annular seal lip that protrudes on both the front and back surfaces of the intermediate portion in the radial direction and extends in the circumferential direction is formed integrally with the disc-shaped rubber elastic plate, and the annular seal lip of the rubber elastic plate is sandwiched from the front and back sides by the partition member. In addition, the pressure in the pressure receiving chamber and the equilibrium chamber is surrounded by the annular seal lip of the rubber elastic plate through a through hole provided in the partition member. While constituting the hydraulic pressure absorption mechanism to be exerted on the surface,
An annular thin portion is formed on the outer peripheral side of the annular seal lip in the rubber elastic plate, and the outer peripheral portion of the rubber elastic plate located radially outward of the annular thin portion is curved in the thickness direction. In addition, an annular accommodating portion that accommodates the outer peripheral portion of the rubber elastic plate is formed in the partition member, and the annular accommodating portion communicates with the pressure receiving chamber and the equilibrium chamber through a communication hole provided in the annular accommodating portion. A fluid-filled vibration isolating device characterized in that a second orifice passage is formed in the annular housing portion so as to go around the outer peripheral portion of the rubber elastic plate and communicate the pressure receiving chamber and the equilibrium chamber. .   The fluid-filled type vibration damping device according to claim 1, wherein the outer peripheral portion of the rubber elastic plate is integrally formed with buffer protrusions extending in the circumferential direction so as to protrude from both the front and back surfaces at the inner peripheral edge and the outer peripheral edge.   The buffer protrusions respectively formed on the inner and outer peripheral edge portions of the front and back surfaces of the outer peripheral portion of the rubber elastic plate are both undulated in the circumferential direction with respect to the inner surface of the annular housing portion. The fluid-filled vibration isolator according to claim 2, which is in contact with at least the top of the outer peripheral portion.   In the partition member, the engagement member is engaged with at least one of the annular seal lips formed on the front and back surfaces of the rubber elastic plate in a state of contacting the inner peripheral surface and restricting the radially inward displacement. The fluid-filled vibration isolator according to any one of claims 1 to 3, wherein a stop protrusion is formed.   The first orifice passage and the first through hole are formed by at least one of the through hole that exerts the pressure of the pressure receiving chamber on the central portion of the rubber elastic plate and the through hole that exerts the pressure of the equilibrium chamber. The fluid-filled vibration isolator according to any one of claims 1 to 4, wherein a third orifice passage tuned to a frequency region higher than any of the two orifice passages is formed.   6. The fluid-filled vibration isolating device according to claim 1, wherein the first orifice passage is formed in the partition member so as to extend in an outer circumferential side from the annular housing portion in a circumferential direction. apparatus.