JP2013228045A - Fluid-filled vibration damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid-filled vibration damping device having a novel structure, in which switching of vibration damping characteristics corresponding to input vibrations from a vehicle can be carried out without using an external driving mechanism, and which can be achieved in a compact and lightweight manner, without increasing the number of components.SOLUTION: A cylindrical peripheral wall part 76 extending toward an equilibrium chamber 44 is disposed on the outer peripheral edge of a movable rubber membrane 74; the peripheral wall part 76 is brought into tight contact with the inner peripheral wall part 65 of a partition member 36; an opening window 58 is covered with the peripheral wall part 76; and an end part 80 on the equilibrium chamber side of the peripheral wall part 76 is fixed to the partition member 36, while an end part 78 on the pressure-receiving chamber side of the peripheral wall part 76 is deformable to fall to the inner peripheral side of a hole 64 accompanying elastic deformation of the movable rubber membrane 74 toward the equilibrium chamber 46. When a pressure variation equal to or higher than a prescribed value occurs in the pressure-receiving chamber 44, the end part 78 on the pressure-receiving chamber side of the peripheral wall part 76 of the movable rubber membrane 74 falls to the inner peripheral side of the hole 64 to deform, and a first orifice passage 62 is made to communicate with the pressure-receiving chamber 44 via the opening window 58.

Description

  The present invention relates to a fluid-filled vibration isolator that obtains an anti-vibration effect by a fluid flow action through an orifice passage that communicates between a pressure receiving chamber and an equilibrium chamber, and in particular, an anti-vibration characteristic according to input vibration. The present invention relates to a fluid filled type vibration isolator capable of switching between the two.

  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 2. Description of the Related Art A fluid-filled vibration isolator that obtains an anti-vibration 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 for automobiles. 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 fluid is sealed is formed, and an orifice passage that allows fluid flow between the pressure receiving chamber and the equilibrium chamber is formed. 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, in an engine mount for automobiles, etc., an anti-vibration effect is required for each of a plurality of types of vibrations having different frequencies and amplitudes that are input according to vehicle running conditions, etc. Since the frequency range in which the vibration-proofing effect based on the fluid flow action is effectively exhibited is narrow, it is often difficult to sufficiently achieve the vibration-proofing property required by the single orifice passage. Therefore, two orifice passages, a first orifice passage tuned to a predetermined frequency range and a second orifice passage tuned to a higher frequency range, are formed in parallel between the pressure receiving chamber and the equilibrium chamber, and the two By selectively communicating / blocking the two orifice passages with a switching valve that is operated using a pneumatic or electromagnetic external drive mechanism, a vibration-proofing effect is obtained against vibrations in a plurality of or a wide frequency range. There has been proposed a fluid-filled vibration isolator as described above. For example, those described in Japanese Patent Application Laid-Open No. 9-310732 (Patent Document 1).

  However, in such a fluid-filled vibration isolator having a conventional structure, an external drive mechanism is required to change the communication / blocking state of the plurality of orifice passages to switch the vibration isolating characteristics, and the running state Therefore, a control system for controlling the switching by the drive mechanism according to the need is also required, and it is inevitable that the apparatus becomes larger and more complicated and the manufacturing cost is increased accordingly.

  In particular, it is difficult to meet the recent demands for miniaturization and weight reduction of automobiles with a structure for switching vibration isolation characteristics by an external drive mechanism, and to realize switching of vibration isolation characteristics in a compact and lightweight manner. Therefore, it has been desired to provide an improved fluid-filled vibration isolator capable of satisfying the requirements.

Japanese Patent Laid-Open No. 9-310732

  The present invention has been made in the background of the above-mentioned circumstances, and the problem to be solved is to switch the vibration-proof characteristics according to the input vibration from the vehicle without using an external drive mechanism. It is an object of the present invention to provide a fluid-filled vibration isolator having a novel structure that can be realized in a compact and lightweight manner without an increase.

  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 outer peripheral portion of the partition member is extended in the circumferential direction. The first orifice passage allowing fluid flow between the pressure receiving chamber and the equilibrium chamber, and the through hole provided in the central portion of the partition member are arranged so that the pressure in the pressure receiving chamber and the equilibrium chamber is on both sides. In a fluid-filled vibration isolator having a movable rubber film exerted on the surface The inner peripheral wall portion defining the through hole of the partition member is provided with an opening window through which the first orifice passage communicates with the pressure receiving chamber, and on the outer peripheral edge portion of the movable rubber film. Is provided with a cylindrical peripheral wall portion extending toward the equilibrium chamber side, the peripheral wall portion is in close contact with the inner peripheral wall portion of the partition member, and the opening window is covered with the peripheral wall portion, The end of the peripheral wall on the side of the equilibrium chamber is fixed to the partition member, while the end of the peripheral wall on the side of the pressure receiving chamber is elastically deformed toward the equilibrium chamber of the movable rubber film. The pressure-receiving chamber side end of the peripheral wall portion of the movable rubber film falls to the inner peripheral side of the through-hole when a pressure fluctuation of a predetermined value or more occurs in the pressure-receiving chamber. The first orifice passage is deformed so as to communicate with the pressure receiving chamber through the opening window. Than is.

  According to this aspect, the vibration isolation characteristics of the fluid filled type vibration damping device can be switched using the elastic deformation of the movable rubber film based on the pressure fluctuation in the pressure receiving chamber. Specifically, when high-frequency small-amplitude vibration with a relatively small amplitude difference is input, the pressure fluctuation in the pressure-receiving chamber is smaller than a predetermined value. It remains in close contact with the peripheral wall and the open window is kept closed. Therefore, the communication to the pressure receiving chamber through the opening window of the first orifice passage is not manifested. On the other hand, when a low frequency large amplitude vibration with a relatively large amplitude difference is input, the pressure fluctuation of the pressure receiving chamber becomes a predetermined value or more. By falling down and deforming, communication with the pressure receiving chamber through the opening window of the first orifice passage is developed.

  For example, if the communication of the first orifice passage to the pressure receiving chamber is realized only through the opening window, the first orifice passage does not appear at the time of high-frequency small-amplitude vibration input such as traveling noise and idling vibration. Based on the elastic deformation of the central portion of the movable rubber film toward the pressure receiving chamber side and the equilibrium chamber side, these vibrations can be absorbed and the vibration isolation effect by the low dynamic spring can be exhibited. In addition, at the time of low-frequency and large-amplitude vibration input such as engine shake, the end portion of the movable rubber film on the pressure receiving chamber side of the peripheral wall portion collapses and deforms, and the first orifice passage communicates with the pressure receiving chamber side through the opening window. Thereby, the high attenuation | damping performance based on the fluid flow through a 1st orifice channel | path can be expressed.

  Alternatively, in addition to the opening window, the first orifice passage is provided with an opening that communicates with the pressure receiving chamber at all times, and the opening is opened to the pressure receiving chamber through the opening window rather than the flow path length of the first orifice passage that opens to the pressure receiving chamber through the opening. It is also possible to set the length of the first orifice passage to be short. In this case, the fluid flow of the first orifice passage through the opening is tuned to the primary mode vibration (low order vibration) of idling vibration, and the first orifice passage through the opening is input when the primary mode vibration is input. The anti-vibration effect by the low dynamic spring is developed based on the fluid flow. When the secondary mode vibration (high-order vibration) of idling vibration is input, the flow resistance of the long first orifice passage through the opening increases, so that the pressure fluctuation in the pressure receiving chamber becomes a predetermined value or more, and the movable rubber The pressure receiving chamber side end of the peripheral wall portion of the membrane collapses and deforms, and the first orifice passage communicates with the pressure receiving chamber side through the opening window. Thereby, the vibration-proofing effect by the low dynamic spring against the secondary mode vibration based on the fluid flow through the first orifice passage through the opening window, that is, the first orifice passage having a short orifice length and a small flow resistance is obtained. It is also possible to express it.

  As described above, in this aspect, it is possible to switch the vibration isolating characteristics of the fluid filled type vibration isolator according to the input vibration by using the elastic deformation of the movable rubber film based on the pressure fluctuation in the pressure receiving chamber. Therefore, as in the past, the vibration-insulating characteristics can be switched without using an external mechanism such as an actuator, and a fluid-filled vibration-proof device capable of expressing an excellent vibration-proofing effect corresponding to a wide frequency is lightweight with a simple structure. It can be realized in a compact and low cost.

  It should be noted that the degree of the deformation of the movable rubber film due to the pressure fluctuation in the pressure receiving chamber can be appropriately set in consideration of the desired vibration isolation characteristics such as the flow resistance of the orifice and the tuning frequency. Further, as is clear from the above-described examples, the first orifice passage is communicated with the pressure receiving chamber through the opening that is always open to the pressure receiving chamber, or communicated with the pressure receiving chamber only through the opening window. However, it is obvious that the effect of switching the anti-vibration characteristics using the elastic deformation of the movable rubber film of the present invention can be expressed, and any aspect thereof is included in the present invention.

  According to a second aspect of the present invention, in the fluid-filled vibration isolator according to the first aspect, the partition member has at least one of the through hole of the partition member on the pressure receiving chamber side and the equilibrium chamber side. And having a cover wall portion disposed opposite to the movable rubber film with a gap, and a second orifice passage is formed by a through-hole penetrating the cover wall portion. The pressure of at least one of the pressure receiving chamber and the equilibrium chamber is applied to the movable rubber film through the second orifice passage.

  According to this aspect, the fluid flow through the second orifice passage is caused by the elastic deformation of the movable rubber film. Therefore, by adjusting the diameter and length of the second orifice passage, the vibration proof performance is achieved. Can be arbitrarily set.

  According to a third aspect of the present invention, in the fluid filled type vibration damping device according to the second aspect, the partition member covers the through hole of the partition member from the equilibrium chamber side, and the movable rubber film is formed on the movable rubber film. An equilibration chamber side cover wall portion that is disposed opposite to and spaced from the clearance chamber, and the equilibration chamber side end portion of the peripheral wall portion of the movable rubber film is fitted into the equilibration chamber side cover wall portion. While the fitting groove is formed and fixed, the movable rubber film is provided with a stopper protrusion that protrudes toward the equilibrium chamber side cover wall.

  According to this aspect, the equilibration chamber side end of the peripheral wall portion of the movable rubber film can be obtained by providing the fitting groove in the equilibrium chamber side cover wall portion, and only fitting the equilibrium chamber side end portion of the peripheral wall portion of the movable rubber film therein. The part can be easily fixed to the partition member. Moreover, since the movable rubber film is provided with a stopper projection, when the movable rubber film is elastically deformed, the stopper projection abuts against the equilibrium chamber side cover wall portion, so that the peripheral wall portion of the movable rubber film is excessively deformed. Is prevented, the movable rubber film is prevented from being detached from the fitting groove, and the movable rubber film can be stably positioned and held in the through hole. As described above, in this aspect, it is possible to switch the vibration isolating characteristics of the fluid filled type vibration isolator according to the input vibration by using the elastic deformation of the movable rubber film based on the pressure fluctuation in the pressure receiving chamber. Therefore, as in the past, the vibration-insulating characteristics can be switched without using an external mechanism such as an actuator, and a fluid-filled vibration-proof device capable of expressing an excellent vibration-proofing effect corresponding to a wide frequency is lightweight with a simple structure. It can be realized in a compact and low cost.

  According to the fluid-filled vibration isolator of the present invention, the first orifice passage does not appear when high-frequency small-amplitude vibration having a relatively small amplitude difference is input, and the pressure-receiving chamber side and the equilibrium chamber in the central portion of the movable rubber film Based on the elastic deformation to the side, the vibration-proofing effect by the low dynamic spring can be exhibited. Further, when vibration of low frequency and large amplitude such as an engine shake is input, the end of the movable rubber film on the side of the pressure receiving chamber falls down and deforms, and the first orifice passage is communicated with the pressure receiving chamber through the opening window. High attenuation performance based on can be expressed. In this way, the vibration isolation characteristics can be switched without using an external mechanism such as an actuator. Therefore, a fluid-filled vibration isolation device capable of producing an excellent vibration isolation effect corresponding to a wide frequency is lightweight and compact with a simple structure. And it can be realized at low cost.

It is a longitudinal cross-sectional view of the engine mount for motor vehicles as 1st embodiment of this invention, Comprising: II sectional drawing in FIG. Explanatory drawing which shows the expression state of the 1st orifice channel | path in the engine mount for motor vehicles shown by FIG. III-III sectional drawing in FIG. It is a longitudinal cross-sectional view of the engine mount for motor vehicles as 2nd embodiment of this invention, Comprising: IV-IV sectional drawing in FIG. It is VV sectional drawing in FIG. 6, Comprising: Explanatory drawing which shows the expression state of the 1st orifice channel | path in 2nd embodiment of this invention. VI-VI sectional drawing in FIG. The schematic diagram for demonstrating the switching means of the vibration proof characteristic in 2nd embodiment of this invention.

  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, FIGS. 1 to 3 show an automobile engine mount 10 as a first embodiment according to a fluid-filled vibration isolator 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.

  On the other hand, the second mounting member 14 includes a cylindrical portion 22 having a large-diameter cylindrical shape, and a constricted portion that protrudes radially inward by bending or the like in the upper opening of the cylindrical portion 22. 24 is formed, and a flange-like portion 26 that extends outward in the radial direction is integrally formed at the opening periphery of the constricted portion 24.

  The first mounting member 12 is disposed on substantially the same central axis at a predetermined distance above the second mounting member 14 in the axial direction. The first mounting member 12 and the second mounting member 12 The member 14 is elastically connected by the 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 inner peripheral surface of the upper end portion of the second mounting member 14 is 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. Further, a seal rubber layer 32 that covers substantially the entire surface is formed on the inner peripheral surface of the cylindrical portion 22 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. It is supported. 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.

  Further, as shown in FIG. 1, the partition member 36 has a thin annular plate-shaped pressure receiving chamber side cover wall portion 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 pressure receiving chamber side cover wall portion 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 cylindrical portion 22 in the assembled state to the second mounting member 14. Further, at one end in the circumferential direction of the circumferential groove 56, an inner peripheral wall portion 65 that defines a later-described through-hole 64 of the partition member 36 opens into the pressure receiving chamber 44 through a later-described through-hole 64 and a through-hole 90. An opening window 58 is provided therethrough, and a communication hole 60 that opens to the equilibrium chamber 46 side is formed at the other circumferential end of the circumferential groove 56. Thus, a first orifice passage 62 is formed that extends in the circumferential direction of the outer peripheral portion of the partition member 36 and can communicate the pressure receiving chamber 44 and the equilibrium chamber 46 with each other. It should be noted that the passage length, the cross-sectional area, etc. of the first orifice passage 62 are such that the resonance frequency of the fluid that flows inside the first orifice passage 62 is in a low frequency region corresponding to the engine shake to be damped. It has been tuned to.

  A circular through hole 64 that opens to the pressure receiving chamber 44 side is formed in the central portion of the main body partition plate 52. Further, an equilibrium chamber side cover wall portion 66 that covers the through hole 64 from the equilibrium chamber 46 side is formed integrally with the bottom of the through hole 64 so as to extend from the main body partition plate 52. The equilibrium chamber side cover wall portion 66 is provided with a plurality of through holes 68 extending in the plate thickness direction. In the present embodiment, the shape and arrangement of each through hole 68 are the pressure receiving chamber side cover wall portion 54. It has the same shape as a later-described through-hole 88 provided in. Further, a fitting groove 70 in which an equilibrium chamber side end portion 80 of a peripheral wall portion 76 of the movable rubber film 74 described later is fitted and fixed to the outer peripheral edge portion of the equilibrium chamber side cover wall portion 66 on the pressure receiving chamber 44 side. It is provided continuously over the entire circumference.

  Further, a movable rubber film 74 is accommodated in the accommodation recess 72 surrounded by the through hole 64 of the main body partition plate 52 and the equilibrium chamber side cover wall 66. The movable rubber film 74 has a disk shape as a whole, and in this embodiment, in particular, a cylindrical peripheral wall 76 that extends continuously in a vertically long rectangular cross section over the entire periphery of the outer peripheral edge is integrated. Is formed. The peripheral wall portion 76 protrudes toward both sides of the outer peripheral edge of the movable rubber film 74 on the pressure receiving chamber 44 side and the equilibrium chamber 46 side, and in the equilibrium chamber side end portion 80 rather than the pressure receiving chamber side end portion 78. The protruding height is increased. Further, a central projection 82 projecting toward the pressure receiving chamber side cover wall portion 54 and a stopper projection 84 projecting toward the equilibrium chamber side cover wall portion 66 are formed at the central portion of the movable rubber film 74. The protrusion height of 82 is smaller than the end portion 78 on the pressure receiving chamber side, and the protrusion height of the stopper projection 84 is smaller than that of the end portion 80 on the equilibrium chamber side.

  The movable rubber film 74 is assembled in the housing recess 72 so as to spread in the direction perpendicular to the axis, and the equilibrium chamber side end 80 of the peripheral wall 76 of the movable rubber film 74 is connected to the equilibrium chamber side cover wall 66. The fitting groove 70 is fitted and fixed over the entire circumference. In this assembled state, the pressure receiving chamber side cover wall portion 54 and the equilibrium chamber side cover wall portion 66 of the main body partition plate 52 are arranged to face the movable rubber film 74 with a gap.

  On the other hand, the pressure receiving chamber side cover wall portion 54 has a thin, substantially disk shape, and a shallow concave portion 86 having a circular shape is formed in the center portion. A plurality (four in this embodiment) of through-holes 88 are provided in the bottom of the recess 86 in the thickness direction. Each through-hole 88 has a substantially arc shape that extends over substantially ¼ circumference, and four through-holes 88 are arranged at substantially equal intervals in the circumferential direction of the bottom of the recess 86. A substantially arc-shaped through-hole 90 is formed in the outer peripheral edge of the pressure receiving chamber side cover wall 54 so as to open the peripheral edge of the through hole 64 and extend in the circumferential direction. The pressure receiving chamber side cover wall portion 54 configured as described above is overlapped and fixed to the main body partition plate 52 to form the partition member 36.

  In a state where the pressure receiving chamber side cover wall portion 54 is assembled to the main body partition plate 52, the peripheral wall portion 76 of the movable rubber film 74 is fitted into the fitting groove 70 on the main body partition plate 52 side to be engaged and held. In addition, the pressure receiving chamber side cover wall portion 54 is disposed to face the pressure receiving chamber side cover wall 54 with a slight gap therebetween. Thereby, the peripheral wall portion 76 of the movable rubber film 74 has the equilibrium chamber side end portion 80 fixed to the partition member 36, while the pressure receiving chamber side end portion 78 falls to the inner peripheral side of the through hole 64 and can be deformed. In this state, the partition member 36 is advantageously held. In particular, in the present embodiment, the inner peripheral wall portion 65 that defines the through hole 64 of the main body partition plate 52 is also held in contact with the partition member 36, so that the partition member 36 can be more firmly held. Further, as a result, the peripheral wall portion 76 of the movable rubber film 74 is brought into close contact with the inner peripheral wall portion 65 of the partition member 36, and the opening window 58 penetrating the inner peripheral wall portion 65 is covered with the peripheral wall portion 76 of the movable rubber film 74. Thus, the first orifice passage 62 that communicates the pressure receiving chamber 44 and the equilibrium chamber 46 with each other is prevented from appearing unless the peripheral wall portion 76 falls and deforms toward the inner peripheral side.

  The upper surface of the movable rubber film 74 is exposed to the pressure receiving chamber 44 through a through hole 88 formed in the pressure receiving chamber side cover wall portion 54, and the pressure receiving chamber 44 is exposed to the exposed surface through the through hole 88. The pressure is directly applied. Further, the lower surface of the movable rubber film 74 is exposed to the equilibrium chamber 46 through a through hole 68 formed in the equilibrium chamber side cover wall 66 of the main body partition plate 52, and is exposed to the exposed surface through the through hole 68. The pressure in the equilibrium chamber 46 is directly exerted.

  According to the automobile engine mount 10 of the present embodiment having such a structure, the first orifice passage 62 is closed when, for example, high-frequency small-amplitude vibration such as idling vibration or running-over noise is input. Therefore, the elastic deformation is performed in the vertical direction based on the pressure difference exerted on the upper and lower surfaces of the movable rubber film 74 from the pressure receiving chamber 44 and the equilibrium chamber 46. That is, it is formed by the second orifice passage 92 on the pressure receiving chamber side formed by the through hole 88 penetrating the pressure receiving chamber side cover wall portion 54 and the through hole 68 penetrating the equilibrium chamber side cover wall portion 66. The pressure of the pressure receiving chamber 44 and the equilibrium chamber 46 is applied to the movable rubber film 74 through the second orifice passage 94 on the equilibrium chamber side. Due to the elastic deformation of the movable rubber film 74 in the vertical direction, A pressure fluctuation smaller than a predetermined value generated in the pressure receiving chamber 44 is absorbed by the equilibrium chamber 46. As a result, the anti-vibration performance at the time of inputting high frequency small amplitude vibration is improved.

  On the other hand, when a pressure fluctuation exceeding a predetermined value is generated in the pressure receiving chamber 44 due to the input of low-frequency large-amplitude vibration such as engine shake, for example, the pressure in the pressure receiving chamber 44 and the equilibrium chamber 46 is increased. Based on the difference, a larger pressure is applied to the movable rubber film 74, and the central portion of the movable rubber film 74 is elastically deformed so as to swell greatly toward the equilibrium chamber 46 side. As a result, as shown in FIG. 2, the pressure receiving chamber side end portion 78 of the peripheral wall portion 76 of the movable rubber film 74 is elastic so that it falls down toward the center of the movable rubber film 74 on the inner peripheral side of the through hole 64. Accordingly, the opening window 58 is communicated with the pressure receiving chamber 44 through the through hole 90 and the first orifice passage 62 is developed.

  When the first orifice passage 62 is developed, direct fluid flow from the pressure receiving chamber 44 to the equilibrium chamber 46 is allowed. Therefore, low-frequency large-amplitude vibration based on fluid flow through the first orifice passage 62 is allowed. High damping effect is exhibited. As is clear from FIG. 2, excessive falling deformation of the peripheral wall portion 76 of the movable rubber film 74 is caused by the pressure receiving chamber side end portion 78 of the peripheral wall portion 76 and the recess portion 86 of the pressure receiving chamber side cover wall portion 54. It is regulated by contact.

  As described above, according to the present embodiment, the vibration isolation characteristics of the automobile engine mount 10 can be switched using the elastic deformation of the movable rubber film 74 based on the pressure fluctuation of the pressure receiving chamber 44. Specifically, when a high-frequency small-amplitude vibration such as a running-over sound or idling vibration is input, the pressure fluctuation of the pressure receiving chamber 44 is smaller than a predetermined value, so that the outer peripheral edge of the peripheral wall 76 of the movable rubber film 74 is partitioned. It remains in close contact with the inner peripheral wall 65 of the housing recess 72 of the member 36, and the opening window 58 is maintained in the closed state. Therefore, the communication to the pressure receiving chamber 44 through the through hole 90 of the first orifice passage 62 is not expressed, and based on the elastic deformation of the central portion of the movable rubber film 74 toward the pressure receiving chamber 44 side and the equilibrium chamber 46 side, Therefore, the vibration-proofing effect of the low dynamic spring can be exhibited. On the other hand, at the time of low-frequency large-amplitude vibration input such as engine shake, the pressure fluctuation in the pressure-receiving chamber 44 becomes a predetermined value or more, and therefore the pressure-receiving chamber side end portion 78 of the peripheral wall portion 76 of the movable rubber film 74 is movable rubber film 74. With the elastic deformation toward the equilibrium chamber 46 side, it falls down and deforms toward the inner peripheral side of the through hole 64, and communication with the pressure receiving chamber 44 through the opening window 58 of the first orifice passage 62 is developed. Thereby, high damping performance based on fluid flow through the first orifice passage 62 can be exhibited.

  As described above, in this embodiment, the vibration isolation characteristics of the automotive engine mount 10 according to the input vibration can be switched using the elastic deformation of the movable rubber film 74 based on the pressure fluctuation in the pressure receiving chamber 44. Therefore, as in the past, the vibration-insulating characteristics can be switched without using an external mechanism such as an actuator, and a fluid-filled vibration-proof device capable of expressing an excellent vibration-proofing effect corresponding to a wide frequency is lightweight with a simple structure. It can be realized in a compact and low cost.

  In the present embodiment, the fluid flow through the second orifice passages 92 and 94 is caused by the elastic deformation of the movable rubber film 74, so that the size and shape of the second orifice passages 92 and 94 are adjusted. By doing so, the vibration proof performance can be arbitrarily set.

  Further, in the present embodiment, the fitting groove 70 is provided in the equilibrium chamber side cover wall portion 66, and the equilibrium chamber side end portion 80 of the peripheral wall portion 76 of the movable rubber film 74 is fitted into the fitting groove 70. The equilibrium chamber side end 80 of the peripheral wall 76 can be easily fixed to the partition member 36. In addition, since the movable rubber film 74 is provided with the stopper protrusions 84, when the movable rubber film 74 is elastically deformed, the stopper protrusions 84 come into contact with the equilibrium chamber side cover wall portion 66, so that the peripheral wall of the movable rubber film 74. The excessive falling deformation of the portion 76 is prevented, and the movable rubber film 74 is prevented from being detached from the fitting groove 70, so that the movable rubber film 74 can be stably positioned and held in the through hole 64.

  Next, an automotive engine mount 100 as a second embodiment according to the fluid filled type vibration damping device of the present invention is illustrated. In the following embodiment, the structure is the same as that of the first embodiment. About a member and a site | part, the detailed description is abbreviate | omitted by attaching | subjecting the code | symbol same as 1st embodiment in a figure.

  That is, FIGS. 4 to 6 show an automobile engine mount 100 as a second embodiment of the present invention. The automotive engine mount 100 includes (i) a first orifice passage 62 provided with an opening 102 that is always in communication with the pressure receiving chamber 44 in addition to the opening window 58, and (ii) a pressure receiving chamber through the opening 102. The length of the first orifice passage 62 that opens to the pressure receiving chamber 44 through the through-hole 90: L2 is set shorter than the length of the first orifice passage 62 that opens to the passage 44: L1. The embodiment different from the first embodiment is shown.

  More specifically, as described in the first embodiment, one end in the circumferential direction of the circumferential groove 56 is formed with a communication hole 60 that opens to the equilibrium chamber 46 side. A communication hole 104 is provided at the other end in the circumferential direction. Furthermore, a substantially rectangular opening 102 is formed in the pressure receiving chamber side cover wall portion 54 covering the communication hole 104, and the communication hole 104 is always opened to the pressure receiving chamber 44 through the opening 102. As a result, a first orifice passage 62 is formed which extends in the circumferential direction of the outer periphery of the partition member 36 and constantly communicates the pressure receiving chamber 44 and the equilibrium chamber 46 with each other. On the other hand, the opening window 58 that opens to the pressure receiving chamber 44 through the through-hole 90 described in the first embodiment is provided at a substantially central portion in the circumferential direction of the circumferential groove 56 in this embodiment (FIG. 6). reference). As a result, when the peripheral wall portion 76 falls and deforms due to the elastic deformation of the movable rubber film 74, the first orifice passage 62 opens into the pressure receiving chamber 44 through the opening window 58, and the first orifice passage 62 The length of the flow path is shortened to L2 that is approximately half of L1 before the collapse deformation (see FIG. 7).

  As described above, according to the second embodiment of the present invention, the first orifice passage 62 is provided with the opening 102 that always communicates with the pressure receiving chamber 44 in addition to the opening window 58, and the peripheral wall 76 of the movable rubber film 74. By utilizing the falling deformation of the first orifice passage 62, the flow passage length of the first orifice passage 62 can be switched to the short dimension L2 by opening the pressure receiving chamber 44 through the opening window 58. By utilizing such characteristics, for example, the fluid flow of the first orifice passage 62 having the length L1 through the opening 102 is tuned to the primary mode vibration (low order vibration) of the idling vibration, and the primary mode vibration At the time of input, the vibration isolation effect by the low dynamic spring can be exhibited based on the fluid flow of the first orifice passage 62 through the opening 102. When the secondary mode vibration (higher order vibration) of idling vibration is input, the flow resistance of the first orifice passage 62 having the length L1 through the opening 102 is increased, whereby the pressure variation in the pressure receiving chamber 44 is predetermined. The pressure receiving chamber side end portion 78 of the peripheral wall portion 76 of the movable rubber film 74 falls and deforms toward the inner peripheral side of the through hole 64 and the opening window 58 opens into the pressure receiving chamber 44. As a result, the first orifice passage 62 having a length L2 that opens to the pressure receiving chamber 44 through the opening window 58, that is, the first orifice passage 62 having a short orifice length and a reduced flow resistance is developed, and the length L2 is generated. It is possible to exhibit a vibration isolation effect by the low dynamic spring against the secondary mode vibration based on the fluid flow through the first orifice passage 62.

  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, the predetermined value of the pressure fluctuation in the pressure receiving chamber 44 required for the peripheral wall portion 76 of the movable rubber film 74 to fall and deform to such an extent that the opening window 58 is opened is determined by the flow resistance of the orifice passages 62, 92, and 94 It can be set as appropriate in consideration of the desired anti-vibration characteristics such as the tuning frequency. Further, as is clear from the above example, the first orifice passage 62 communicates with the pressure receiving chamber 44 only through the opening 102 that is always open to the pressure receiving chamber 44 or through the opening window 58. However, in any case, the effect of switching the anti-vibration characteristics using the elastic deformation of the movable rubber film 74 of the present invention can be manifested, and it goes without saying that any of these aspects is also included in the present invention.

  Further, although the central protrusion 82 of the movable rubber film 74 is in contact with the pressure receiving chamber side cover wall portion 54, it may be disposed oppositely with a gap. As a result, minute deformation in the vertical direction at the central portion of the movable rubber film 74 is allowed, and an improvement in the anti-vibration effect can be expected. Further, the pressure receiving chamber side cover wall portion 54 may have a flat disk shape without the recessed portion 86 in the central portion.

  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, 54: Pressure receiving chamber side cover wall (cover wall), 58: Opening window, 62: First orifice passage, 64: Through hole, 65: Inner peripheral wall , 66: Equilibrium chamber side cover wall (cover wall), 68: Through hole, 70: Fitting groove, 74: Movable rubber film, 76: Peripheral wall, 78: End of pressure receiving chamber, 80: Equilibrium chamber side End: 84: Stopper projection, 88: Through hole, 92: Second orifice passage on the pressure receiving chamber side (second orifice passage), 94: Second orifice passage on the equilibrium chamber side (second orifice passage)

Claims (3)

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,
A first orifice passage extending in the circumferential direction of the outer periphery of the partition member to allow fluid flow between the pressure receiving chamber and the equilibrium chamber;
In a fluid-filled vibration isolator provided with a movable rubber film that is disposed in a through hole provided in a central portion of the partition member and that exerts pressure on the pressure receiving chamber and the equilibrium chamber on both side surfaces,
On the inner peripheral wall portion that defines the through hole of the partition member, an opening window that communicates the first orifice passage with the pressure receiving chamber is provided,
The outer peripheral edge of the movable rubber film is provided with a cylindrical peripheral wall extending toward the equilibrium chamber. The peripheral wall is in close contact with the inner peripheral wall of the partition member, and the opening window is The peripheral wall is covered with the peripheral wall, and the end of the peripheral wall on the side of the equilibrium chamber is fixed to the partition member, while the end of the peripheral wall on the pressure receiving chamber is elastic to the side of the equilibrium of the movable rubber film. With the deformation, it is possible to fall and deform to the inner peripheral side of the through hole,
When a pressure fluctuation of a predetermined value or more occurs in the pressure receiving chamber, the pressure receiving chamber side end portion of the peripheral wall portion of the movable rubber film falls to the inner peripheral side of the through hole and the first orifice passage is formed. A fluid-filled vibration isolator that communicates with the pressure receiving chamber through the opening window.   The partition member includes a cover wall portion that covers the through hole of the partition member from at least one of the pressure receiving chamber side and the equilibrium chamber side, and is opposed to the movable rubber film with a gap. A second orifice passage is formed by a through-hole penetrating the cover wall, and at least one of the pressure receiving chamber and the equilibrium chamber with respect to the movable rubber film through the second orifice passage. 2. The fluid filled type vibration damping device according to claim 1, wherein pressure is applied.   The partition member includes an equilibrium chamber side cover wall portion that covers the through hole of the partition member from the equilibrium chamber side and is disposed to face the movable rubber film with a gap therebetween, and the equilibrium chamber The side cover wall portion is formed with a fitting groove in which the end portion on the side of the equilibrium chamber of the peripheral wall portion of the movable rubber film is fitted and fixed, while the movable rubber film has the equilibrium chamber. The fluid-filled vibration isolator according to claim 2, further comprising a stopper protrusion that protrudes toward the side cover wall.

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