JP2013227991A - Fluid filled vibration damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid filled vibration damping device having a novel structure capable of achieving any of the emergence of a short circuit flow passage for preventing generation of cavitation during input of an impulsive vibration load and a pressure variation absorption function of a pressure receiving chamber by a movable rubber membrane at a high level without increasing the number of components and the size of the device.SOLUTION: An outer peripheral edge part of a movable rubber membrane 78 is in contact with and held between an equilibrium chamber side support part 70 and a contact holding part 90 formed at a pressure receiving chamber side support part 84 in a portion covered by the pressure receiving chamber side support part 84, and elastic deformation to a pressure receiving chamber 44 side is allowed by a non-cover lid region 86 not covered by the pressure receiving chamber side support part 84. A short circuit flow passage 96 reaching from an equilibrium chamber 46 to the pressure receiving chamber 44 emerges by the separation of the outer peripheral edge part of the movable rubber membrane 78 from the equilibrium chamber side support part 70 based on the elastic deformation of the non-cover lid region 86 to the pressure receiving chamber 44 side. The central part of the movable rubber membrane 78 is elastically deformed to the pressure receiving chamber 44 side and the equilibrium chamber 46 side by pressure variation.

Description

  The present invention relates to a fluid-filled vibration isolator that obtains a vibration isolation effect by a fluid flow action through an orifice passage communicating with a pressure receiving chamber and an equilibrium chamber, and more particularly, in a frequency range higher than the tuning frequency of the orifice passage. The present invention relates to a fluid-filled vibration isolator equipped with a pressure fluctuation absorbing mechanism made of a movable rubber film that absorbs pressure fluctuation in a pressure receiving chamber when a vibration is input.

  Conventionally, as a type of vibration isolator that is interposed between members constituting a vibration transmission system and mutually anti-vibration-couples or supports the vibration transmission system, the non-encapsulated inside A fluid-filled vibration isolator that obtains a vibration isolation effect based on a fluid action such as a resonance action of a compressible fluid is known, and is widely used as an engine mount, body mount, differential mount, suspension member mount, etc. for automobiles. It is used. In this fluid filled type vibration isolator, the first mounting member and the second mounting member are elastically connected by the main rubber elastic body, and incompressible on both sides of the partition member supported by the second mounting member. Each of the pressure receiving chamber and the equilibrium chamber in which a fluid is sealed is formed, and a first orifice passage is formed to communicate the pressure receiving chamber and the equilibrium chamber with each other. At the time of vibration input, an anti-vibration effect is exhibited based on the fluid flow action through the orifice passage caused by the relative pressure fluctuation caused between the pressure receiving chamber and the equilibrium chamber.

  By the way, the anti-vibration effect exhibited by the resonance action of the fluid through the orifice passage is limited to a relatively narrow frequency range in which the orifice passage is tuned in advance. Therefore, in recent years, when vibration that is a problem in the frequency range higher than the tuning frequency of the orifice passage is input, vibration suppression is achieved by absorbing and reducing pressure fluctuations in the pressure receiving chamber due to a significant increase in the flow resistance of the orifice passage. In order to improve the characteristics, a fluid-filled vibration isolator having a structure provided with a pressure fluctuation absorbing mechanism has been proposed. In this pressure fluctuation absorption mechanism, a movable rubber film is disposed on a partition member that partitions a pressure receiving chamber and an equilibrium chamber as disclosed in Japanese Patent Application Laid-Open No. 07-035189 (Patent Document 1). The pressure of the pressure receiving chamber is applied to one surface of the rubber film, and the pressure of the equilibrium chamber is applied to the other surface. And, by the elastic deformation of the movable rubber film based on the relative pressure difference between the pressure receiving chamber and the equilibrium chamber, the pressure variation of the pressure receiving chamber caused by the substantial blockage of the orifice passage is absorbed, A significant increase in dynamic spring is avoided.

  However, even in the fluid-filled vibration isolator having such a pressure fluctuation absorption mechanism, further improvement in characteristics may be required. That is, in an engine mount or the like, a shocking vibration load may be input between the first mounting member and the second mounting member, and at that time, an excessive negative pressure is generated in the pressure receiving chamber. As a result, the so-called cavitation problem has been pointed out, in which the sealed fluid in the pressure receiving chamber undergoes liquid phase separation and bubbles are generated, and the bubbles are crushed, causing abnormal noise and vibration.

  In order to cope with this problem, the applicant previously disclosed in Japanese Patent No. 4861843 (Patent Document 2) that the outer peripheral edge of the movable rubber film is supported from the equilibrium chamber side to the equilibrium chamber side of the partition member over the entire circumference. A structure has been proposed in which the central portion and a part of the outer peripheral edge of the movable rubber film are held in contact with each other by the pressure receiving chamber side support portion of the partition member from the pressure receiving chamber side. According to this, when an excessive negative pressure is generated in the pressure receiving chamber due to an impact load input, a part of the circumference of the outer peripheral edge of the movable rubber film is elastically deformed toward the pressure receiving chamber by the negative pressure. By separating from the equilibrium chamber side support portion, a short circuit channel from the equilibrium chamber to the pressure receiving chamber is developed. Therefore, the negative pressure in the pressure receiving chamber is quickly eliminated by the fluid flow from the equilibrium chamber to the pressure receiving chamber through the short-circuit channel, and the occurrence of cavitation can be suppressed. Further, since the central portion of the movable rubber film is allowed to be elastically deformed toward the equilibrium chamber without being held in contact with the partition member, the pressure fluctuation is based on the elastic deformation of the central portion of the movable rubber film. Absorption function is also demonstrated.

  As described above, the fluid-filled vibration isolator disclosed in Patent Document 2 has a special shape for the partition member that supports the movable rubber film, so that a short-circuit flow path is formed on a part of the outer peripheral edge of the movable rubber film. The valve mechanism can also be provided, and it is not necessary to separately form a short-circuit channel or a valve member, and the occurrence of cavitation can be suppressed without increasing the number of parts and increasing the size of the device. It was an epoch-making structure.

  However, due to the special shape of the partition member, there is a limit to fully exhibit the pressure fluctuation absorbing function. That is, the central portion of the movable rubber film is allowed to be elastically deformed toward the equilibrium chamber side, but is elastically deformed toward the pressure-receiving chamber side by the contact of the partition member with the pressure-receiving chamber side support portion. In order to sufficiently improve the pressure fluctuation absorbing function by the rubber film, there was room for further improvement.

Japanese Patent Application Laid-Open No. 07-035189 Japanese Patent No. 4618443

  The present invention has been made in the background of the above-mentioned circumstances, and its solution is to prevent the occurrence of cavitation when an impact vibration load is input without increasing the number of parts or increasing the size of the apparatus. An object of the present invention is to provide a fluid-filled vibration isolator having a novel structure capable of achieving both the expression of a short-circuit channel and the function of absorbing pressure fluctuations of a pressure receiving chamber by a movable rubber film.

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

  That is, the first aspect of the fluid-filled vibration isolator having a structure according to the present invention includes a first mounting member and a second mounting member elastically connected by a main rubber elastic body, and the second mounting member. A partition member supported by the pressure sensor, a pressure receiving chamber which is located on one side of the partition member and in which a part of the wall portion is configured by the main rubber elastic body and in which an incompressible fluid is sealed, and the partition An equilibrium chamber in which a part of the wall portion is formed of a flexible film and is filled with the incompressible fluid, and the pressure receiving chamber and the equilibrium chamber communicate with each other, located on the other side of the member. In the fluid filled type vibration damping device, comprising: an orifice passage; and a movable rubber film disposed in a central portion of the partition member and exerting pressure on the pressure receiving chamber and the equilibrium chamber on both side surfaces. The outer peripheral edge of the movable rubber film is in contact with the equilibrium chamber side And a pressure receiving chamber side support portion that covers the outer peripheral edge portion of the movable rubber film from the pressure receiving chamber side, and the outer peripheral edge portion of the movable rubber film includes the pressure receiving portion. The pressure receiving chamber side support portion is held in contact with and held between the contact holding portion formed on the pressure receiving chamber side support portion and the equilibrium chamber side support portion in the portion covered by the chamber side support portion. Elastic deformation toward the pressure receiving chamber is allowed in the non-covering region not covered by the cover, and the outer peripheral edge of the movable rubber film is in the equilibrium state based on elastic deformation of the non-covering region toward the pressure receiving chamber. A short-circuit flow path from the equilibrium chamber to the pressure receiving chamber is developed by separating from the chamber side support portion, and a central portion of the movable rubber film is a pressure fluctuation between the pressure receiving chamber and the equilibrium chamber. Based on the elastic deformation to the pressure receiving chamber side and the equilibrium chamber side. , The pressure fluctuation absorbing mechanism for absorbing the pressure fluctuations of the pressure receiving chamber of the high frequency range than the tuning frequency of the orifice passage in which are configured.

  According to this aspect, the portion of the outer peripheral edge of the movable rubber film that is covered by the pressure receiving chamber side support portion is contacted between the equilibrium chamber side support portion and the contact holding portion of the pressure receiving chamber side support portion. Since it is held in contact, the movable rubber film can be reliably positioned and held with respect to the partition member, and the desired pressure fluctuation absorbing function can be stably exhibited.

  In addition, a non-covered cover region that is not covered by the pressure receiving chamber side support portion of the outer peripheral edge of the movable rubber film is elastically deformed toward the pressure receiving chamber side and separated from the equilibrium chamber side, so that the equilibrium chamber is changed to the pressure receiving chamber. Because the short-circuit channel to reach is stably expressed, when excessive negative pressure is generated in the pressure-receiving chamber due to shock load input, the fluid flow through the short-circuit channel causes the pressure-receiving chamber to The negative pressure can be eliminated quickly to prevent cavitation.

  Moreover, the central part of the movable rubber film is not held in contact with the partition member from either side of the pressure receiving chamber and the equilibrium chamber, and both sides of the pressure receiving chamber side and the equilibrium chamber side are caused by pressure fluctuations in the pressure receiving chamber and the equilibrium chamber. It is possible to reliably deform elastically. Therefore, when a problem vibration is input in a frequency range higher than the tuning frequency of the orifice passage, the pressure variation in the pressure receiving chamber accompanying the significant increase in the flow resistance of the orifice passage is changed to the pressure receiving pressure in the central portion of the movable rubber membrane. Absorption can be reduced based on sufficient elastic deformation to both the chamber side and the equilibrium chamber side. In short, a sufficient pressure fluctuation absorbing function is exhibited by the pressure fluctuation mechanism constituted by the central portion of the movable rubber film, and the vibration isolation characteristics can be improved.

  The pressure-receiving chamber side support portion may be a contact holding portion in which the entire region abuts and holds the outer peripheral edge portion of the movable rubber film, or further on the inner peripheral side than the outer peripheral edge portion of the movable rubber film. You may form including the extending part which extends. And when the pressure receiving chamber side support part has an extension part, the vibration damping characteristic of the pressure absorption mechanism by the movable rubber film is tuned by adjusting the extension amount to the inner peripheral side of the extension part. Is also possible. Further, in the pressure receiving chamber side support portion, the contact holding portion needs to be in contact with the outer peripheral edge portion of the movable rubber film. However, in the case where other portions such as an extension portion are included, these portions are movable. The rubber film does not necessarily have to be in contact with the rubber film, and may be disposed to face each other with a gap.

  The central portion of the movable rubber film is closer to the inner peripheral side than the outer peripheral edge of the movable rubber film held in contact between the equilibrium chamber side support portion and the contact holding portion of the pressure receiving chamber side support portion. It refers to the area that is located.

  According to a second aspect of the present invention, there is provided the fluid filled type vibration damping device according to the first aspect, wherein a plurality of locations separated at equal intervals in the circumferential direction of the outer peripheral edge portion of the movable rubber film are in the circumferential direction. Covered from the pressure receiving chamber side by the plurality of pressure receiving chamber side support portions spaced apart at equal intervals, and between the contact holding portion of the pressure receiving chamber side support portion and the equilibrium chamber side support portion. The plurality of locations on the outer peripheral edge of the movable rubber film are held in contact with each other.

  According to this aspect, a plurality of locations spaced at equal intervals in the circumferential direction on the outer peripheral edge portion of the movable rubber film are held in contact between the contact holding portion of the pressure receiving chamber side support portion and the equilibrium chamber side support portion. Therefore, the outer peripheral edge of the movable rubber film can be supported by the partition member with a relatively uniform support balance. In addition, since the non-covering regions that cause the short-circuit flow path when shocking load is input are arranged at equal intervals in the circumferential direction, negative pressure can be quickly applied regardless of the location where excessive negative pressure is generated in the pressure receiving chamber. This eliminates the cavitation preventing effect. In consideration of the support strength of the contact holding portion, the amount of elastic deformation of the non-covering region, etc., it is desirable that the pressure receiving chamber side support portions are provided at three locations in the circumferential direction.

  According to a third aspect of the present invention, in the fluid-filled vibration damping device according to the first or second aspect, the partition member has an inner peripheral side of the equilibrium chamber side support portion with respect to the movable rubber film. On the other hand, a through hole for applying pressure to the equilibrium chamber is provided, and an inner peripheral edge portion of the pressure receiving chamber side support portion is located on an outer peripheral side with respect to an outer peripheral edge portion of the through hole.

  According to this aspect, since the inner peripheral edge portion of the pressure receiving chamber side support portion is located on the outer peripheral side with respect to the outer peripheral edge portion of the through hole, the movable rubber film that can be elastically deformed to the equilibrium chamber side through the through hole. The entire area of the central portion can be elastically deformed also on the pressure receiving chamber side without interfering with the pressure receiving chamber side support portion. Therefore, in the central portion of the movable rubber film, the entire region that does not interfere with the partition member can be sufficiently elastically deformed on either the equilibrium chamber side or the pressure receiving chamber side, and a stable pressure fluctuation absorbing function is advantageously exhibited. The

  According to a fourth aspect of the present invention, in the fluid-filled vibration isolator according to any one of the first to third aspects, the circumferential length of the non-covering region in the outer peripheral edge of the movable rubber film. However, it is made larger than the circumferential length of the part contacted and held by the contact holding part of the pressure receiving chamber side support part.

  According to this aspect, since the portion that is not restrained is larger than the portion that is restrained by the partition member in the outer peripheral edge portion of the movable rubber film, the non-covered region exhibits a short-circuit flow path. It can be sufficiently elastically deformed to the pressure receiving chamber side, and the short-circuit channel can be reliably developed.

  According to a fifth aspect of the present invention, in the fluid filled type vibration damping device according to any one of the first to fourth aspects, the pressure receiving chamber side support portion is more movable than the contact holding portion. This includes an extending portion that extends to the inner peripheral side.

  According to this aspect, since the pressure receiving chamber side support portion includes the contact holding portion and the extending portion extending to the inner peripheral side of the movable rubber film from the contact holding portion, the contact holding portion In addition to stably holding the outer peripheral edge of the movable rubber film, it is also possible to tune the anti-vibration characteristics of the pressure absorbing mechanism by the movable rubber film by adjusting the extension amount of the extension part appropriately. Thus, it is possible to improve the degree of freedom in setting the vibration isolation characteristics.

  According to the fluid filled type vibration damping device of the present invention, the portion of the outer peripheral edge of the movable rubber film that is covered by the pressure receiving chamber side support portion is in contact with the equilibrium chamber side support portion and the pressure receiving chamber side support portion. Since it is held in contact with the holding portion, the intended pressure fluctuation absorbing function can be stably exhibited. In addition, in the non-covering region that is not covered by the pressure receiving chamber side support part, a short-circuit flow path from the equilibrium chamber to the pressure receiving chamber is stably expressed. It is possible to suppress the occurrence of cavitation. Moreover, the central part of the movable rubber film is not held in contact with the partition member from either side of the pressure receiving chamber and the equilibrium chamber, and both sides of the pressure receiving chamber side and the equilibrium chamber side are caused by pressure fluctuations in the pressure receiving chamber and the equilibrium chamber. Therefore, the anti-vibration characteristics can be improved.

It is a longitudinal cross-sectional view of the engine mount for motor vehicles as one Embodiment of this invention, Comprising: The figure corresponded in the III-III cross section of FIG. The top view of the partition member which comprises the engine mount for motor vehicles shown by FIG. III-III sectional drawing in FIG. The bottom view of the main body partition plate which comprises the partition member shown by FIG. The principal part explanatory drawing for demonstrating the expression state of a short circuit flow path in the engine mount for motor vehicles shown by FIG.

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

  First, FIG. 1 shows an automobile engine mount 10 as an embodiment according to the fluid filled type vibration damping device of the present invention. The engine mount 10 for an automobile has a structure in which a metal first mounting member 12 and a metal second mounting member 14 are connected by a main rubber elastic body 16. Further, the engine mount 10 for an automobile has a first mounting member 12 attached to the power unit side, while a second mounting member 14 is attached to the body side, so that the power unit is mounted on the body to another engine (not shown). It is designed to support vibration isolation in cooperation with the mount. Under such a mounted state, the first mounting member 12 and the second mounting member 14 are attached to the engine mount 10 for an automobile as the main rubber elastic body 16 is elastically deformed by the input of the shared load of the power unit. The main vibration to be vibrated is moved between the first mounting member 12 and the second mounting member 14 in a substantially vertical direction in FIG. Will be entered. As shown in FIG. 1, the automobile engine mount 10 of the present embodiment has a mount center axis (center axes of the first and second mounting members 12 and 14) in a substantially vertical direction, as shown in FIG. 1. Therefore, in the following description, unless otherwise specified, the vertical direction in FIG. 1 is the vertical direction.

  More specifically, the first mounting member 12 has a substantially inverted truncated cone block shape, and includes a screw hole 18 drilled on the central axis from the large-diameter end face. The first mounting member 12 is fixed to a power unit (not shown) by a fixing bolt (not shown) screwed into the screw hole 18.

  The second mounting member 14 has a large-diameter, generally cylindrical shape, and a step portion 20 is provided at an axially intermediate portion. One side (the upper side in the figure) in the axial direction is the large-diameter portion 22 across the stepped portion 20, and the other side in the axial direction is the small-diameter portion 24.

  The first mounting member 12 is coaxially disposed on the central axis of the second mounting member 14 so as to be spaced apart upward in the axial direction, and the first mounting member 12 and the second mounting member are mounted on the same axis. The member 14 is connected by a main rubber elastic body 16.

  The main rubber elastic body 16 has a substantially frustoconical shape, and has a tapered outer peripheral surface that gradually decreases in diameter toward the upper side in the axial direction. The first mounting member 12 is vulcanized and bonded to the main rubber elastic body 16 in a state of being inserted downward in the axial direction from the end surface on the small diameter side. Further, the second attachment member 14 is superimposed on the inner peripheral surface of the large-diameter portion 22 and vulcanized and bonded to the outer peripheral surface of the large-diameter side end portion of the main rubber elastic body 16. In short, in the present embodiment, the main rubber elastic body 16 is an integrally vulcanized molded product that is vulcanized and bonded to the outer peripheral surface of the first mounting member 12 and the inner peripheral surface of the second mounting member 14, respectively. Has been.

  Thus, in the integrally vulcanized molded product of the main rubber elastic body 16, the axially upper opening of the second mounting member 14 is fluid-tightly closed by the main rubber elastic body 16, and the lower part in the axial direction. An internal recess 30 is formed that opens toward the front. In addition, a seal rubber layer 32 that covers substantially the entire surface is formed on the inner peripheral surface of the small diameter portion 24 of the second mounting member 14 so as to extend integrally from the main rubber elastic body 16.

  Furthermore, a partition member 36 and a diaphragm 40 as a flexible film are fitted and assembled into the internal recess 30 in the integrally vulcanized molded product of the main rubber elastic body 16 from the opening portion in the axial direction lower side. ing. The opening of the internal recess 30 (the lower opening of the second mounting member 14) is fluid-tightly closed by the diaphragm 40, and the fluid chamber 42 is formed between the axially opposing surfaces of the main rubber elastic body 16 and the diaphragm 40. It is defined. Further, the fluid chamber 42 is divided into two parts by being partitioned by a partition member 36, and a pressure receiving chamber 44 in which a part of the wall portion is configured by the main rubber elastic body 16 is formed above the partition member 36. In addition, below the partition member 36, an equilibrium chamber 46 is formed in which a part of the wall portion is constituted by the diaphragm 40.

  Here, the diaphragm 40 is composed of a thin disk-shaped rubber film that is slack so that it can be easily deformed, and a ring metal fitting 50 having a substantially annular plate shape is vulcanized on the outer peripheral edge thereof. It is glued. The ring fitting 50 is inserted into the lower end opening of the second mounting member 14 and fixed by caulking, whereby the diaphragm 40 is fixed to the second mounting member 14 and the second mounting member 14 is fixed. A fluid chamber 42 is formed by fluidly closing the axially lower opening. The fluid chamber 42 is filled with an incompressible fluid such as water, alkylene glycol, polyalkylene glycol, or silicone oil. Note that a low-viscosity fluid of 0.1 Pa · s or less is preferably used as the sealed fluid.

  As shown in FIGS. 2 to 4, the partition member 36 has a thin annular plate-shaped holding plate bracket 54 superimposed on the upper surface side of the thin annular plate-shaped main body partition plate 52. It has a fixed composite structure. The main body partition plate 52 and the holding plate fitting 54 can be formed of a hard material such as a synthetic resin material or a metal material.

  In addition, a circumferential groove 56 that is open to the outer peripheral surface and continuously extends in the circumferential direction with a length of one round or less is formed in the outer peripheral edge portion of the main body partition plate 52. The opening to the outer peripheral surface of the circumferential groove 56 is covered with the small diameter portion 24 in the assembled state to the second mounting member 14. Further, a communication hole 58 that opens to the pressure receiving chamber 44 side is formed at one end portion in the circumferential direction of the circumferential groove 56, and the other end portion in the circumferential direction of the circumferential groove 56 toward the equilibrium chamber 46 side. An open communication hole 60 is formed. Thus, an orifice passage 62 is formed that extends in the circumferential direction of the outer peripheral portion of the partition member 36 and communicates the pressure receiving chamber 44 and the equilibrium chamber 46 with each other. Note that the passage length, the cross-sectional area, and the like of the orifice passage 62 are tuned so that the resonance frequency of the fluid that flows inside the orifice passage 62 is in a low frequency region corresponding to the engine shake to be shaken.

  In addition, a circular housing recess 64 that opens to the pressure receiving chamber 44 side is formed in the central portion of the main body partition plate 52. On the outer peripheral edge portion of the bottom surface of the housing recess 64, an equilibrium chamber side support portion 70 that holds an outer peripheral edge portion of a movable rubber film 78, which will be described later, in contact with the equilibrium chamber 46 side is continuously provided over the entire circumference. Is provided. A circular through hole 72 is formed on the inner peripheral side of the equilibrium chamber side support portion 70 so as to penetrate the central portion of the main body partition plate 52 in the plate thickness direction. Furthermore, on the upper surface of the equilibrium chamber side support portion 70, an engagement circumferential groove 74 is formed that extends continuously in an arcuate cross section over the entire circumference in the circumferential direction. Further, a circular fitting peripheral wall 76 having a diameter larger than that of the housing recess 64 and opening to the pressure receiving chamber 44 side is formed above the housing recess 64 of the main body partition plate 52.

  Further, a movable rubber film 78 is accommodated in the accommodation recess 64 of the main body partition plate 52. The movable rubber film 78 has a disk shape as a whole, and in this embodiment, in particular, an annular rib 80 that continuously extends in a circular cross section over the entire circumference of the outer peripheral edge portion is integrally formed. The outer diameter of the annular rib 80 is larger than the thickness of the central portion of the movable rubber film 78. As a result, the movable rubber film 78 has a central portion at the outer peripheral edge where the annular rib 80 is formed. The wall thickness dimension is made larger.

  The movable rubber film 78 is assembled in the housing recess 64 so as to spread in the direction perpendicular to the axis, and the lower surface of the outer peripheral edge of the movable rubber film 78 is all around the balance chamber side support part 70. It is mounted in a contact state. Note that the radius of curvature of the outer peripheral surface of the annular rib 80 is substantially the same as or slightly larger than the radius of curvature of the engagement circumferential groove 74 of the equilibrium chamber side support portion 70. The annular rib 80 is fitted into and engaged with an engagement circumferential groove 74 formed in the equilibrium chamber side support portion 70.

  On the other hand, the holding plate metal 54 has a substantially annular plate shape, and a window portion 82 is formed in the radial center portion thereof. The pressure receiving chamber side support that covers the outer peripheral edge of the movable rubber film 78 from the pressure receiving chamber 44 side is provided at a plurality of positions (three positions in the present embodiment) spaced at equal intervals in the circumferential direction of the outer peripheral edge 83 of the holding plate metal fitting 54. The portion 84 is formed so as to protrude inward in the radial direction. As shown in FIGS. 2 and 3, the holding plate fitting 54 configured as described above is configured such that the outer peripheral surface of the outer peripheral edge portion 83 is fitted into the fitting peripheral wall portion 76 of the main body partition plate 52, and the partition member 36. Is configured. They are assembled with the movable rubber film 78 sandwiched between them. Under such an assembled state, the movable rubber film 78 is divided into a region covered by the pressure receiving chamber side support portion 84 from the pressure receiving chamber 44 side and a non-covered lid region 86 not covered by the pressure receiving chamber side support portion 84. It is done.

  As shown in FIG. 3, the pressure receiving chamber side support portion 84 is in contact with and holds the annular rib 80 provided on the outer peripheral edge portion of the movable rubber film 78 with the equilibrium chamber side support portion 70. And an extending portion 92 that extends further to the inner peripheral side (inward in the radial direction) of the movable rubber film 78 than the abutment holding portion 90. In the outer peripheral edge portion of the movable rubber film 78, the circumferential length of the non-covering region 86 is larger than the circumferential length of the portion of the pressure receiving chamber side support portion 84 that is in contact with and held by the contact holding portion 90. Has been. Further, the outer peripheral edge portion of the window portion 82 of the holding plate fitting 54, which is the inner peripheral edge portion of the pressure receiving chamber side support portion 84, is positioned on the outer peripheral side with respect to the outer peripheral edge portion of the through hole 72 of the main body partition plate 52.

  As described above, the outer peripheral edge portion of the holding plate metal piece 54 is fitted to the fitting peripheral wall portion 76 of the main body partition plate 52 in a state where the holding plate metal piece 54 is superimposed on the upper surface of the main body partition plate 52. The holding plate metal 54 and the main body partition plate 52 are positioned and fixed to each other.

  In the holding plate metal 54, the pressure receiving chamber side support portion 84 is opposed to the equilibrium chamber side support portion 70 with a predetermined distance in the axial direction. Further, an engagement circumferential groove 94 extending in the circumferential direction with an arcuate cross section is formed on the lower surface of the contact holding portion 90 of the pressure receiving chamber side support portion 84. The radius of curvature of the engagement circumferential groove 94 is substantially the same as or slightly smaller than the radius of curvature of the outer peripheral surface of the annular rib 80, and the annular rib 80 of the movable rubber film 78 is engaged with the pressure receiving chamber side support portion 84. It is inserted into the circumferential groove 94 and engaged therewith.

  Under the state in which the holding plate fitting 54 is assembled to the main body partition plate 52, the annular rib 80 of the movable rubber film 78 is engaged with the engagement circumferential groove 74 on the main body partition plate 52 side and the pressure receiving chamber side support portion 84 side. The circumferential grooves 94 are respectively fitted and held. In short, when the movable rubber film 78 is assembled to the partition member 36, the annular rib 80 has an abutment holding portion between the equilibrium chamber side support portion 70 and the pressure receiving chamber side support portion 84 from both the upper and lower sides in the plate thickness direction. By being held in contact with 90, even if elastic deformation of the central region of the movable rubber film 78 toward the pressure receiving chamber 44 and the equilibrium chamber 46 is allowed, it can be advantageously held by the partition member 36. . In particular, in the present embodiment, it is sandwiched between the engaging circumferential grooves 74 and 94 formed in the main body partition plate 52 and the holding plate fitting 54, respectively, and is engaged and sandwiched by these engaging circumferential grooves 74 and 94. As a result, the partition member 36 can be more firmly held. In addition, the opening peripheral part of the through-hole 72 of the main body partition plate 52 is made into the edge part cross-sectional shape curved toward the downward direction (direction separated from the movable rubber film 78), and the movable rubber film 78 by an opening edge part is carried out. Damage is prevented.

  The upper surface of the movable rubber film 78 is exposed to the pressure receiving chamber 44 through a window portion 82 formed in the holding plate metal 54, and the pressure of the pressure receiving chamber 44 is applied to the exposed surface through the window portion 82. It has come to be directly affected. The lower surface of the movable rubber film 78 is exposed to the equilibrium chamber 46 through a through hole 72 formed in the main body partition plate 52, and the pressure in the equilibrium chamber 46 is directly applied to the exposed surface through the through hole 72. It has come to be affected.

  As is clear from this, in the present embodiment, the outer peripheral portion of the movable rubber film 78 is in contact with the pressure receiving chamber 44 side by the contact holding portion 90 of the pressure receiving chamber side support portion 84 of the holding plate fitting 54. And the outer peripheral portion of the movable rubber film 78 is held in contact with the upper surface of the equilibrium chamber side support portion 70 of the main body partition plate 52 from the equilibrium chamber 46 side.

  As a result, when vibration in a frequency range higher than the tuning frequency of the orifice passage 62, for example, high-frequency small amplitude vibration such as idling vibration or traveling boom noise, is input, the pressure is received along with the substantial blockage of the orifice passage 62. When pressure is induced in the chamber 44 or the equilibrium chamber 46, the central portion of the movable rubber film 78 is located in the through-hole 72 (equilibrium chamber 46 side) and the window portion based on the pressure difference exerted on the upper and lower surfaces of the movable rubber film 78. By being elastically deformed in the vertical direction in 82 (pressure receiving chamber 44 side), minute positive and negative pressure fluctuations in the pressure receiving chamber 44 are released to the equilibrium chamber 46. As a result, a significant increase in the dynamic spring associated with the substantial blockage of the orifice passage 62 at the time of inputting high-frequency small-amplitude vibration is reduced or avoided, and the vibration-proof performance is improved. In short, in this embodiment, the pressure fluctuation absorbing mechanism is configured by the partition member 36 including the equilibrium chamber side support portion 70 and the pressure receiving chamber side support portion 84 that can hold the movable rubber film 78 only by the outer peripheral edge portion. is there.

  On the other hand, when an excessively large and sudden negative pressure is generated in the pressure receiving chamber 44 due to the input of shocking and large amplitude vibration when the step is overcome, the negative pressure generated in the pressure receiving chamber 44 is reduced. Based on the pressure difference from the equilibrium chamber 46, a deformation force is exerted on the movable rubber film 78 in the direction of swelling toward the pressure receiving chamber 44. As a result, as shown in FIG. 5, at the outer peripheral edge portion of the movable rubber film 78, the non-covering region 86 that is allowed to be displaced toward the pressure receiving chamber 44 is elastically deformed so as to be turned up. Allowed and produced. As a result, the outer peripheral edge portion of the movable rubber film 78 is separated upward from the equilibrium chamber side support portion 70 at the portion where the window portion 82 is formed. Accordingly, the movable rubber film 78 and the equilibrium chamber side support portion are separated. Due to the gap 70, a short-circuit channel 96 that allows the pressure receiving chamber 44 and the equilibrium chamber 46 to communicate directly is developed.

  When this short-circuit channel 96 is developed, the fluid flow directly from the equilibrium chamber 46 to the pressure receiving chamber 44 is allowed without being restricted by the movable rubber film 78, so The negative pressure is eliminated as quickly as possible, or the generation of an excessive negative pressure is avoided. Therefore, the generation of abnormal noise due to cavitation when an impact load is input can be effectively prevented. FIG. 5 exaggerates the elastic deformation amount of the movable rubber film 78 in order to make it easy to understand the expression of the short-circuit channel 96.

  As described above, according to this embodiment, the central portion of the movable rubber film 78 is not held in contact with the partition member 36 from either side of the pressure receiving chamber 44 and the equilibrium chamber 46, and the pressure receiving chamber Due to the pressure fluctuations of the pressure chamber 44 and the equilibrium chamber 46, it is possible to reliably elastically deform both the pressure receiving chamber 44 side and the equilibrium chamber 46 side. As a result, when a vibration that is a problem in a frequency range higher than the tuning frequency of the orifice passage 62 is input, the pressure fluctuation of the pressure receiving chamber 44 caused by a significant increase in the flow resistance of the orifice passage 62 is caused to be generated in the movable rubber film 78. Absorption can be reduced based on sufficient elastic deformation to both the pressure receiving chamber 44 side and the equilibrium chamber 46 side of the central portion, and the vibration isolation characteristics can be improved.

  Moreover, the outer peripheral edge portion of the movable rubber film 78 is held in contact between the equilibrium chamber side support portion 70 and the pressure receiving chamber side support portion 84, and is reliably positioned and held with respect to the partition member 36. Thus, the function of absorbing pressure fluctuation accompanying the elastic deformation of the movable rubber film 78 can be stably exhibited. When an excessive negative pressure is generated in the pressure receiving chamber 44, the non-covering region 86 is elastically deformed satisfactorily and the short circuit channel 96 is developed, so that the negative pressure in the pressure receiving chamber 44 can be quickly eliminated. . Thus, in the present embodiment, the expression of the short-circuit channel 96 and the pressure fluctuation absorbing function of the pressure receiving chamber 44 by the movable rubber film 78 can be highly realized without increasing the number of components and the size of the apparatus. is there.

  In particular, in this embodiment, a plurality of locations that are equally spaced in the circumferential direction on the outer peripheral edge of the movable rubber film 78 are between the contact holding portion 90 of the pressure receiving chamber side support portion 84 and the equilibrium chamber side support portion 70. Since they are held in contact with each other, the outer peripheral edge of the movable rubber film 78 can be supported by the partition member 36 with a relatively uniform support balance. In addition, since the non-covering regions 86 that allow the short-circuit channel 96 to appear when an impact load is input are arranged at equal intervals in the circumferential direction, the pressure receiving chamber 44 can be promptly used regardless of where the excessive negative pressure is generated. The negative pressure can be eliminated and a cavitation preventing effect can be obtained advantageously. In consideration of the support strength of the contact holding portion 90 and the amount of elastic deformation of the non-covering region 86, the pressure receiving chamber side support portions 84 are preferably provided at three locations in the circumferential direction. Not.

  Furthermore, in this embodiment, since the inner peripheral edge of the pressure receiving chamber side support portion 84 is located on the outer peripheral side with respect to the outer peripheral edge of the through hole 72, it can be elastically deformed toward the equilibrium chamber 46 through the through hole 72. The entire region of the central portion of the movable rubber film 78 can be elastically deformed also on the pressure receiving chamber 44 side without interfering with the pressure receiving chamber 44 side support surface. Therefore, in the central portion of the movable rubber film 78, the entire region that does not interfere with the partition member 36 can be sufficiently elastically deformed on either the equilibrium chamber 46 side or the pressure receiving chamber 44 side, and a stable pressure fluctuation absorbing function can be achieved. It is beneficial.

  In particular, in the outer peripheral edge portion of the movable rubber film 78, the non-covering region is larger than the circumferential length of the portion held between the pressure holding chamber side support portion 84 and the equilibrium chamber side support portion 70 by the contact holding portion 90. Since the circumferential length of 86 is increased, the non-covered region 86 can be sufficiently elastically deformed toward the pressure receiving chamber 44 to the extent that the short-circuit channel 96 is developed, and the short-circuit channel 96 is reliably developed. Can be done.

  Further, the pressure receiving chamber side support portion 84 includes the contact holding portion 90 and the extending portion 92 that extends further to the inner peripheral side of the movable rubber film 78 than the contact holding portion 90. The outer peripheral edge of the movable rubber film 78 is stably held by the portion 90, and the vibration damping characteristics of the pressure absorbing mechanism by the movable rubber film 78 are tuned by appropriately adjusting the extension amount of the extension portion 92. It is also possible to improve the degree of freedom in setting the vibration isolation characteristics.

  In addition, when the vibration-proof characteristics of the fluid-filled vibration isolator having the structure described in Patent Document 2 previously proposed by the applicant and the fluid-filled vibration-proof device of the present embodiment were measured, the damping effect by the orifice passage 62 was measured. It was found that the same effect as in Patent Document 2 can be obtained. Further, it was confirmed that the low dynamic spring characteristic of the device was improved by about 10% with respect to the input vibration in the frequency range of 60 to 200 Hz with respect to the pressure fluctuation absorbing function by the elastic deformation of the movable rubber film 78.

  As mentioned above, although embodiment of this invention was explained in full detail, these are illustration to the last, Comprising: This invention is not limited at all by the specific description in these embodiment.

  For example, in the above-described embodiment, the entire region including the contact holding part 90 and the extension part 92 of the pressure-receiving chamber side support part 84 is in contact with the movable rubber film 78. A gap may be provided between 92 and the movable rubber film 78. Further, the extension portion 92 is not necessarily provided in the pressure receiving chamber side support portion 84, and the entire pressure receiving chamber side support portion 84 may be the contact holding portion 90.

  Further, in the equilibrium chamber side support portion 70, the engagement circumferential groove 74 needs to be in contact with the outer peripheral edge portion of the movable rubber film 78, but the other portion, for example, the tip portion of the annular protrusion 98 is The movable rubber film 78 is not necessarily in contact with the movable rubber film 78, and may be disposed to face each other with a gap. Thereby, a minute deformation in the vertical direction of the movable rubber film 78 is allowed, and an improvement in the vibration isolation effect can be expected.

  Further, it is not always necessary to provide a plurality of pressure receiving chamber side support portions 84 at equal intervals in the circumferential direction, and a plurality of pressure receiving chamber side support portions 84 may be provided at unequal intervals in the circumferential direction, and have a divided portion at one circumferential position. One pressure receiving chamber side support portion extending in a circumferential shape may be provided.

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

10: Engine mount for automobile (fluid-filled vibration isolator), 12: first mounting member, 14: second mounting member, 16: rubber elastic body of main body, 36: partition member, 40: diaphragm (flexibility Membrane), 44: Pressure receiving chamber, 46: Equilibrium chamber, 62: Orifice passage, 70: Equilibrium chamber side support portion, 72: Through hole, 78: Movable rubber membrane, 84: Pressure receiving chamber side support portion, 86: Non-covering region , 90: contact holding part, 92: extension part, 96: short circuit flow path

Claims (5)

A first attachment member and a second attachment member elastically connected by a main rubber elastic body;
A partition member supported by the second mounting member;
A pressure receiving chamber in which a part of the wall portion is formed of the main rubber elastic body and in which an incompressible fluid is sealed, located on one side of the partition member;
An equilibrium chamber that is located on the other side of the partition member and in which a part of the wall portion is formed of a flexible film and in which the incompressible fluid is enclosed,
An orifice passage communicating the pressure receiving chamber and the equilibrium chamber with each other;
In a fluid-filled vibration isolator comprising a movable rubber film that is disposed in a central part of the partition member and that exerts pressure on the pressure receiving chamber and the equilibrium chamber on both side surfaces,
An equilibrium chamber side support portion that holds the outer peripheral edge portion of the movable rubber film in contact with the partition member from the equilibrium chamber side, and a pressure receiving chamber side that covers the outer peripheral edge portion of the movable rubber film from the pressure receiving chamber side. A support is provided,
The outer peripheral edge portion of the movable rubber film is abutted between the contact holding portion formed on the pressure receiving chamber side support portion and the equilibrium chamber side support portion in a portion covered with the pressure receiving chamber side support portion. On the other hand, elastic deformation toward the pressure receiving chamber is allowed in the non-covering area that is not covered by the pressure-receiving-chamber-side support portion, and is based on elastic deformation of the non-covering area toward the pressure-receiving chamber. The outer peripheral edge of the movable rubber film is separated from the equilibrium chamber side support portion, so that a short-circuit channel from the equilibrium chamber to the pressure receiving chamber is developed,
The central portion of the movable rubber film is elastically deformed to the pressure receiving chamber side and the equilibrium chamber side due to pressure fluctuations of the pressure receiving chamber and the equilibrium chamber, and therefore has a higher frequency range than the tuning frequency of the orifice passage. A fluid-filled vibration isolator comprising a pressure fluctuation absorbing mechanism that absorbs pressure fluctuation in a pressure receiving chamber.   A plurality of locations spaced apart at equal intervals in the circumferential direction of the outer peripheral edge of the movable rubber film are covered from the pressure receiving chamber side by a plurality of pressure receiving chamber side support portions that are spaced apart at equal intervals in the circumferential direction. The plurality of locations on the outer peripheral edge of the movable rubber film are held in contact between the contact holding portion of the pressure receiving chamber side support portion and the equilibrium chamber side support portion. Fluid-filled vibration isolator.   In the partition member, a through hole is provided on the inner peripheral side of the equilibrium chamber side support portion to exert pressure on the movable rubber film against the equilibrium chamber, while an inner peripheral edge portion of the pressure receiving chamber side support portion is The fluid filled type vibration damping device according to claim 1, wherein the fluid filled type vibration damping device is located on the outer peripheral side of the outer peripheral edge portion of the through hole.   In the outer peripheral edge portion of the movable rubber film, the circumferential length of the non-covering region is made larger than the circumferential length of the portion that is held in contact with the contact holding portion of the pressure receiving chamber side support portion. The fluid-filled vibration isolator according to any one of claims 1 to 3.   The fluid-filled type according to any one of claims 1 to 4, wherein the pressure-receiving chamber-side support portion includes an extending portion that extends to an inner peripheral side of the movable rubber film with respect to the contact holding portion. Anti-vibration device.

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