JP2008133937A - Fluid sealing type damping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid sealing type damping device having a novel structure effective for attaining high reliability on the closing-opening of a valve member and achieving the high flow action of the fluid through an orifice flow passage to realize a desired stable damping effect. <P>SOLUTION: A short-circuit flow passage 90 is formed on the outer peripheral side of a movable rubber diaphragm 68 of a partitioning member 32, separately from the orifice flow passage 50. An elastic-wall valve 94 is formed integrally with the movable rubber diaphragm 68, and is protruded from the outer peripheral surface of the movable rubber diaphragm 68. A valve member accepting portion 92 having the elastic-wall valve 94 disposed therein is formed in the short-circuit flow passage 90. The elastic-wall valve 94 is pushed with an elastically fastening margin against a valve seat 82 formed in the valve member accepting portion 92, so that the short-circuit flow passage 90 is kept in the isolation state. The short-circuit flow passage 90 is set into the communication state by the elastic deformation of the elastic-wall valve 94 based on the difference between a negative pressure generated in a pressure chamber 42 and the pressure in a balancing chamber 44. <P>COPYRIGHT: (C)2008,JPO&INPIT

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 a pressure receiving chamber and an equilibrium chamber, and in particular, under a clogged state of an orifice passage. The present invention relates to a fluid-filled vibration isolator equipped with a pressure fluctuation absorbing mechanism that absorbs pressure fluctuation in a chamber based on deformation of a movable rubber film.

  Conventionally, as a type of anti-vibration device such as an anti-vibration support and an anti-vibration coupling body interposed between members constituting the vibration transmission system, a fluid action such as a resonance action of an incompressible fluid enclosed inside There is known a fluid-filled vibration isolator that obtains an anti-vibration effect based on the above. In this fluid-filled vibration isolator, a first mounting member and a cylindrical second mounting member are connected by a main rubber elastic body on one opening side of the second mounting member, and a second Since the other opening of the mounting member is covered with a flexible film, a fluid chamber is provided in which an incompressible fluid is sealed between the main rubber elastic body and the flexible film. In addition, the fluid chamber is partitioned by the partition member supported by the second mounting member, and the pressure receiving chamber and the wall portion in which part of the wall portion is formed of a main rubber elastic body on both sides of the partition member in the fluid chamber An equilibration chamber partially formed of a flexible membrane is formed, and the pressure receiving chamber and the equilibration chamber communicate with each other through an orifice passage formed in the partition member. According to such a structure, a relative pressure fluctuation difference is generated between the pressure receiving chamber and the equilibrium chamber in accordance with the vibration input, and the amount of fluid flowing through the orifice passage is ensured. Since a vibration isolation effect can be obtained based on a fluid action such as an action, application to an engine mount, body mount, differential mount, suspension member mount, etc. for automobiles has been studied.

  However, the anti-vibration effect exerted 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. There was a problem that it was difficult.

  Therefore, for example, when vibrations that are problematic in the frequency range higher than the tuning frequency of the orifice passage are input, the purpose is to suppress the sudden rise in pressure fluctuation caused by the vibrations and to obtain a stable anti-vibration effect. It is proposed to provide a hydraulic pressure absorption mechanism (pressure fluctuation absorption mechanism). As shown in Patent Document 1 (Japanese Patent Laid-Open No. 09-042372), this hydraulic pressure absorbing mechanism is provided with a movable film on a partition member that partitions a pressure receiving chamber and an equilibrium chamber, and is provided on one surface. It has a structure in which the pressure of the pressure receiving chamber is exerted and the pressure of the equilibrium chamber is exerted on the other surface. With the vibration input in the high frequency range, the movable film is deformed and the pressure fluctuation is absorbed, so that a high dynamic spring is avoided.

  By the way, in the above-described conventional fluid-filled vibration isolator, when a shocking vibration load with a large acceleration is input between the first mounting member and the second mounting member, an excessive negative pressure is applied to the pressure receiving chamber. May occur. As a result, there has been a so-called cavitation problem in which abnormal noise and vibration are generated when the fluid in the pressure receiving chamber undergoes liquid phase separation to generate bubbles and the bubbles are crushed.

  With respect to this problem, in Patent Document 1 described above, a tongue-shaped notch is provided in the movable film, and the pressure-receiving chamber and the equilibrium chamber are switched between a communication state and a shut-off state using elastic deformation of the movable film itself. It has been proposed to constitute a valve.

  However, simply forming a notch in the movable membrane may cause the pressure receiving chamber to be short-circuited unnecessarily, coupled with the fact that the opening and closing operation of the valve body is difficult to be controlled reliably. There was also a possibility that the liquid-sealing vibration-proofing effect would be significantly reduced.

  In view of this, the present applicant previously described in Patent Document 2 (Japanese Patent Laid-Open No. 2003-148548) that a part of the wall portion of the partition member forming the orifice passage is formed by a valve body integrally formed with the main rubber elastic body. A constructed fluid-filled vibration isolator was proposed.

  However, in such a fluid-filled vibration isolator, since the orifice passage itself has a short circuit structure, there is a concern that the orifice passage may be unnecessarily opened depending on the use conditions of the vibration isolator, As a result, there is a risk that it is difficult to obtain the reliability of the vibration isolation performance. Further, since the valve body is integrally formed with the main rubber elastic body, the rubber material is limited in order to realize the spring characteristics of the main rubber elastic body to which a large load is input, and this is advantageous for the valve body. It is also assumed that it is difficult to give

Japanese Patent Application Laid-Open No. 09-042372 JP 2003-148548 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is that the reliability of the opening / closing operation of the valve body and the fluid flow action through the orifice passage are In other words, the present invention provides a fluid-filled vibration isolator having a novel structure that can be effectively exhibited and stably obtain a target vibration isolating effect.

  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 feature of the present invention is that the first mounting member and the second mounting member are connected by the main rubber elastic body, and the partition member is supported by the second mounting member, and the partition member is sandwiched. Formed on both sides are a pressure receiving chamber with part of the wall made of rubber elastic body and an equilibrium chamber with part of the wall made of flexible membrane, and these pressure receiving chamber and equilibrium chamber are incompressible While enclosing the fluid, an orifice passage is formed in the outer peripheral portion of the partition member to connect the pressure receiving chamber and the equilibrium chamber to each other, and a movable rubber film is disposed in the central portion of the partition member, In the fluid-filled vibration isolator having the pressure fluctuation absorbing mechanism configured such that the pressure of the pressure receiving chamber is exerted on the surface of the movable rubber film and the pressure of the equilibrium chamber is exerted on the other surface of the movable rubber film, the movable rubber film in the partition member Short-circuit flow separately from the orifice passage And forming an elastic valve integrally with the movable rubber film so that the elastic valve protrudes from the outer peripheral surface of the movable rubber film, and forming a valve body housing portion for disposing the elastic valve in the short-circuit channel Based on the pressure difference between the negative pressure generated in the pressure-receiving chamber and the equilibrium chamber, the elastic valve is pressed against the valve seat provided in the accommodating part with elastic allowance to keep the short-circuit flow path shut off. The fluid-filled vibration isolator is configured such that the short-circuit flow path is brought into communication by elastic deformation of the elastic valve.

  In such a fluid-filled vibration isolator having a structure according to the present invention, the short-circuit channel is provided separately from the orifice passage, so that the fluid flow action through the orifice passage The direct influence of the interruption state is suppressed. In other words, the shape of the orifice passage itself, such as the length and cross-sectional area, is kept stable and constant.

  Further, since the elastic valve that opens and closes the short-circuit channel is formed integrally with the movable rubber film, the elastic valve is realized without increasing the number of parts. Furthermore, when selecting a material for the elastic valve, for example, there is no restriction due to the material of the main rubber elastic body that requires large support spring characteristics, ozone resistance, gasoline resistance, etc. By integrally forming with the rubber film, the required characteristics of the elastic valve can be realized to a high degree.

  In addition, since the elastic valve protrudes from the outer peripheral surface of the movable rubber film and is pressed against the valve seat of the valve body housing portion of the short-circuit channel with an elastic tightening margin, the movable rubber film The deformation of the elastic valve accompanying the deformation is suppressed, and the reliability of the opening / closing operation of the elastic valve is improved.

  Therefore, by reducing the number of parts, the manufacturing process can be advantageously shortened and the cost can be reduced. In addition, the elastic valve can be stably opened and closed to prevent high dynamic springs and the amount of fluid flow through the orifice passage. As a result, the desired vibration-proofing effect can be stably obtained.

  Further, in the fluid filled type vibration damping device according to the present invention, the outer peripheral portion of the partition member extends in the circumferential direction with a length shorter than one circumference in the circumferential direction, and one circumferential end thereof is provided in the pressure receiving chamber. An orifice passage is formed by communicating each end in the direction with the equilibrium chamber through a communication hole, and no orifice passage is formed between one end and the other end in the circumferential direction of the orifice passage. A structure in which a short-circuit channel is formed so as to extend in the circumferential direction in the portion may be employed.

  According to such a structure, since the short-circuit channel is formed by using the surplus space in which the orifice passage in the partition member is formed, the vibration isolator is made compact, and the separate structure of the orifice channel and the short-circuit channel is provided. Can advantageously be realized. In addition, since both the orifice passage and the short-circuit passage extend in the circumferential direction, the degree of freedom in tuning such as the length is increased within a limited range of the partition member. Moreover, even when the thickness dimension of the partition member is small, the displacement stroke of the elastic valve can be secured in the circumferential direction.

  In the fluid filled type vibration damping device according to the present invention, one end of the short-circuit channel is communicated with the pressure receiving chamber through one communication hole of the orifice channel, and the other end of the short-circuit channel is While being connected to the equilibrium chamber through the other communication hole of the orifice passage, the elastic valve opens and closes the short-circuit channel based on the elastic deformation in the circumferential direction of the partition member in the valve body housing portion provided on the short-circuit channel. The structure disposed in the above can be suitably employed.

  According to this structure, the target vibration-proof effect can be exhibited more advantageously. As a result of intensive studies on the cavitation problem in the conventional fluid-filled vibration isolator by the present inventors, it has been found by experiments that the location where cavitation is likely to occur is near the opening of the orifice passage to the pressure receiving chamber. Based on that. That is, the short-circuit channel is formed by utilizing the opening of the orifice passage to the pressure-receiving chamber, so that, in the communication state of the short-circuit channel, in the vicinity of the orifice passage opening that is particularly susceptible to cavitation in the pressure-receiving chamber. Therefore, the excessive negative pressure is quickly and efficiently eliminated. As a result, for example, the cavitation avoidance effect is more excellent than that of a conventional vibration isolator having a short-circuit means provided in the middle portion of the orifice passage as disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 2003-148548). There is expected.

  Further, in the fluid filled type vibration damping device according to the present invention, the short-circuit channel is formed so as to penetrate the partition member in the thickness direction, and the elastic valve is partitioned in the valve body housing portion provided on the short-circuit channel. A structure arranged to open and close the short-circuit channel based on elastic deformation in the thickness direction of the member may be employed.

  According to this, the short-circuit structure is simplified, the manufacture becomes easy, the circumferential space for forming the short-circuit channel can be reduced, and the length of the orifice passage in the circumferential direction is increased accordingly. It is also possible. In addition, when such a fluid-filled vibration isolator is used in an automobile engine mount or the like, the main vibration input direction often extends parallel to the direction in which the pressure receiving chamber and the equilibrium chamber face each other across the partition member. . Here, as in this structure, when the elastic valve is deformed in the thickness direction of the partition member to open and close the short-circuit channel, the elastic valve is efficiently used in the generation of excessive negative pressure in the pressure receiving chamber. As a result of elastic deformation, the effect of preventing cavitation can be further improved.

  Further, in the fluid filled type vibration damping device according to the present invention, the elastic valve that is integrally formed protruding from the movable rubber film has a smaller cross-sectional area at the base end portion on the movable rubber film side than the protruding tip portion. In addition, a contact valve portion that opens and closes the short circuit flow path by contacting a valve seat provided in the short circuit flow path is provided at the protruding tip portion, and an elastic deformation portion is provided at the base end portion. A structure is preferably employed.

  According to such a structure, the cross-sectional area of the elastic deformation part provided in the base end part of the elastic valve is made smaller than the cross-sectional area of the contact valve part provided in the protruding tip part of the elastic valve. Thereby, the opening / closing operation of the elastic valve is ensured mainly by the deformation of the elastic deformation portion, and the deformation of the contact valve portion that contacts the valve seat of the short-circuit channel is suppressed, so that the elastic valve contacts the valve seat. The state is stable. In addition, the moment action based on the elastic deformation portion having a small cross-sectional area is advantageously exhibited, and the opening / closing operation based on the pressure action on the elastic valve can be made more efficient. Therefore, the control performance of the opening / closing operation of the elastic valve, and hence the control performance of the communication / blocking state of the short-circuit flow path can be improved, and the vibration isolation effect can be further improved.

  Further, in the fluid filled type vibration damping device according to the present invention, it is applied to an automobile engine mount, and the orifice passage is tuned so as to exhibit a damping effect in a frequency range corresponding to an engine shake input when the vehicle travels. In addition, a structure may be adopted in which a tightening allowance is set by the elasticity of the elastic valve so that the short-circuit flow path is maintained in a cut-off state when the vibration of the engine shake in which the orifice passage functions is input.

  According to such a structure, an engine shake that becomes a problem in the running state can be advantageously suppressed based on a fluid action such as a resonance action of the fluid through the orifice passage. In addition, for example, when a traveling boom sound or the like in a higher frequency range than the engine shake is input, even if the orifice passage is clogged, the pressure of the pressure receiving chamber is absorbed by the elastic deformation of the movable rubber film. High dynamic springs are avoided. In particular, even when large amplitude vibration is input due to stepping over a step or running a speed breaker, and excessive negative pressure is generated in the pressure receiving chamber, the negative pressure is quickly reduced by the advanced opening / closing operation of the elastic valve. As a result of being efficiently eliminated, abnormal noise caused by cavitation is advantageously suppressed. Such a useful anti-vibration device is realized with a simple structure at low cost based on the reduction in the number of parts by integrating the elastic valve and the movable rubber film, so it can be advantageously applied to automotive engine mounts. Can be done.

  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 automobile engine mount 10 has a structure in which a first mounting member 12 as a first mounting member and a second mounting member 14 as a second mounting member are elastically connected by a main rubber elastic body 16. . The first mounting bracket 12 is mounted on the power unit side, while the second mounting bracket 14 is mounted on the vehicle body side via the bracket bracket 18, thereby providing a pair of vibration isolation target members that are connected to each other for vibration isolation. The power unit is interposed between the power unit and the vehicle body so that the power unit is supported in an anti-vibration manner with respect to the vehicle body.

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

  More specifically, the first mounting member 12 has a substantially cylindrical shape, and a screw hole 20 that opens to the upper end surface is formed on the central axis thereof. The first mounting bracket 12 is fixed to the power unit by a fixing bolt (not shown) that is screwed into the screw hole 20.

  On the other hand, the second mounting bracket 14 has a substantially cylindrical shape with a large diameter as a whole, and a flange-shaped portion 22 that extends in the direction perpendicular to the axis is integrally formed at the upper end portion in the axial direction. The first mounting bracket 12 is positioned on the concentric shaft so as to be separated from the opening portion on the upper side in the axial direction of the second mounting bracket 14, and the first mounting bracket 12 and the second mounting bracket 14. A main rubber elastic body 16 is disposed therebetween.

  The main rubber elastic body 16 has a substantially truncated cone shape as a whole. The first rubber fitting 12 is vulcanized and bonded to the small-diameter side end surface of the main rubber elastic body 16 so as to be inserted in the axial direction, and the large-diameter side end outer peripheral surface of the main rubber elastic body 16 is attached to the main rubber elastic body 16. The inner peripheral surface of the upper portion in the axial direction of the second mounting bracket 14 is overlapped and vulcanized and bonded. In short, the main rubber elastic body 16 is formed as a first integrally vulcanized molded product 24 including the first mounting bracket 12 and the second mounting bracket 14 as shown in FIG. . Further, as apparent from the above description, the first mounting bracket 12 and the second mounting bracket 14 are elastically connected by the main rubber elastic body 16 and one of the second mounting brackets 14 in the axial direction ( The upper opening in FIG. 1 is fluid-tightly closed by the main rubber elastic body 16.

  A mortar-shaped large-diameter recess 26 is formed on the large-diameter side end face of the main rubber elastic body 16 so as to relieve stress when a load is input. A thin seal rubber layer 28 formed integrally with the main rubber elastic body 16 is attached to the inner peripheral surface from the axially intermediate portion to the lower end portion of the second mounting bracket 14. Further, between the opening peripheral edge of the large-diameter recess 26 in the main rubber elastic body 16 and the seal rubber layer 28, an axially intermediate portion of the second mounting bracket 14 extends over the entire circumference so as to be perpendicular to the axis. An annular step surface 30 extending in the direction is formed.

  In such a first integral vulcanized molded article 24, a partition member 32 and a diaphragm 34 as a flexible film are inserted from an opening in the axial direction, and are fitted to the second mounting bracket 14. It is fixed. The partition member 32 has a thick, substantially disk shape, and is formed of a hard material such as metal or synthetic resin. In addition, a circumferential groove 36 is formed in the intermediate portion in the axial direction of the partition member 32 and opens to the outer peripheral surface and extends in the circumferential direction by a predetermined length (a length of a little less than one round in the present embodiment).

  On the other hand, the diaphragm 34 is formed of a thin rubber film, as shown in FIG. 3, and is formed into a substantially thin disk shape having ripples of slack so that it can be easily bent and deformed. It has become. A cylindrical rubber film fixture 38 is vulcanized and bonded to the outer peripheral surface of the diaphragm 34. That is, the diaphragm 34 is formed as a second integrally vulcanized molded product 40 provided with a rubber film fixing bracket 38. The partition member 32 and the rubber film fixing bracket 38 are inserted into the second mounting bracket 14 in the axial direction, and the second mounting bracket 14 is subjected to diameter reduction processing such as eight-way drawing, It is fixedly fitted to the second mounting bracket 14. In particular, since the caulking process is applied to the lower end portion in the axial direction of the second mounting bracket 14, the rubber film fixing bracket 38 is prevented from coming out from the lower end portion in the axial direction. As a result, the opening on the other axial direction (the lower side in FIG. 1) of the second mounting member 14 is covered with the diaphragm 34 in a fluid-tight manner.

  Under such an assembled state, the partition member 32 and the rubber film fixing bracket 38 are overlapped with each other in the axial direction, and between the annular step surface 30 of the main rubber elastic body 16 and the lower end portion of the second mounting bracket 14. , And are positioned in the axial direction. Further, between the fitting surfaces of the partition member 32 and the rubber film fixing bracket 38 and the second mounting bracket 14, a seal rubber layer 28 is sandwiched over the entire surface, and the fluid is between the fitting surfaces. It is tightly sealed.

  Thereby, between the opposing surfaces of the main rubber elastic body 16 and the diaphragm 34 between the first mounting bracket 12 and the second mounting bracket 14 is fluid-tightly closed, and a partition member 32 is provided at an intermediate portion between the opposing surfaces. Is disposed so as to extend in the direction perpendicular to the axis, and on one side in the axial direction across the partition member 32, a part of the wall portion is constituted by the main rubber elastic body 16, and the elasticity of the main rubber elastic body 16 is increased. A pressure receiving chamber 42 is formed in which pressure fluctuations are generated based on deformation. On the other side in the axial direction across the partition member 32, a part of the wall portion is constituted by a diaphragm 34, and the elasticity of the diaphragm 34 is formed. An equilibrium chamber 44 in which a volume change is easily allowed based on the deformation is formed. The pressure receiving chamber 42 and the equilibrium chamber 44 are filled with incompressible fluid such as water, alkylene glycol, polyalkylene glycol, and silicone oil. For example, the incompressible fluid is sealed in the pressure receiving chamber 42 and the equilibrium chamber 44 by, for example, separating the partition member 32 and the second integral vulcanized molded product 40 from the first integral vulcanized molded product 24 in the incompressible fluid. This is advantageously done by assembling.

  Moreover, the opening of the circumferential groove 36 on the outer peripheral surface of the partition member 32 is fluid-tightly covered with the second mounting member 14 to which the seal rubber layer 28 is attached. Both ends in the circumferential direction of the circumferential groove 36 are communicated with one of the pressure receiving chamber 42 and the equilibrium chamber 44 through communication holes 46 and 48 formed in the partition member 32, respectively. As a result, an orifice passage 50 is formed which extends the outer peripheral portion of the partition member 32 in the circumferential direction by a predetermined length (a length of a little less than one round in the present embodiment) and allows the pressure receiving chamber 42 and the equilibrium chamber 44 to communicate with each other. .

  In the present embodiment, the resonance frequency of the fluid that is allowed to flow through the orifice passage 50 is effective against vibrations in a low frequency region around 10 Hz corresponding to an engine shake or the like based on the resonance action of the fluid. It is tuned so that the damping effect is demonstrated. Tuning of the orifice passage 50 is performed by, for example, the rigidity of the wall springs of the pressure receiving chamber 42 and the equilibrium chamber 44, that is, the main rubber elastic body 16 corresponding to the amount of pressure change necessary to change the chambers 42 and 44 by a unit volume. It is possible to adjust the passage length and passage cross-sectional area of the orifice passage 50 while taking into account the characteristic values based on the respective elastic deformation amounts of the diaphragm 34 and the diaphragm 34. In general, the pressure transmitted through the orifice passage 50 The frequency at which the phase of the change changes and becomes a substantially resonant state can be grasped as the tuning frequency of the orifice passage 50.

  In this manner, the first mounting bracket 12 and the second mounting bracket 14 are connected by the main rubber elastic body 16, and the holder body is provided with the pressure receiving chamber 42, the equilibrium chamber 44, the orifice passage 50, etc. The bracket metal fitting 18 is assembled. As shown in FIG. 4, the bracket fitting 18 is made of a rigid material such as iron or aluminum alloy, and has a cup shape from one opening in the axial direction of the cylindrical bracket body 52. The fixed leg part 54 which has is attached, and it is set as the structure fixed by welding etc. integrally. A flange-shaped flange-shaped portion 56 that extends outward is integrally formed at one opening (upper in FIG. 1) in the axial direction of the bracket body 52. On the other hand, an annular receiving portion 58 that protrudes toward the inner peripheral side is integrally formed in the other opening portion in the axial direction of the bracket body 52.

  The second mounting bracket 14 of the mount body is press-fitted into the bracket body 52 of the bracket bracket 18, and the flange-shaped portion 56 of the bracket body 52 is overlapped with the flange-shaped portion 22 of the second mounting bracket 14. The position of the bracket metal 18 in the axial direction with respect to the mount body is defined, and the bracket metal 18 and the mount body are assembled to each other. Further, a bolt insertion hole 60 penetrating inward and outward is formed in the center of the bottom wall portion of the fixed leg portion 54. Then, the outer peripheral surface near the bottom wall portion of the fixed leg portion 54 is partially cut away (not shown), and the bracket is fixed by a fixing bolt (not shown) inserted through the notch into the bolt insertion hole 60 of the fixed leg portion 54. The metal fitting 18 and by extension, the second mounting metal fitting 14 fixed to the bracket metal fitting 18 are fixed to the vehicle body.

  Further, a bottom cover fitting 62 as a cover plate member is assembled between the bracket fitting 18 and the mount body. As shown in FIG. 5, the bottom lid fitting 62 has a shallow dish shape as a whole by the center portion bulging downward. A seal rubber 64 that protrudes upward and continuously extends over the entire circumference in the circumferential direction is bonded to the outer peripheral portion of the bottom lid fitting 62 by vulcanization. The outer peripheral edge portion of the bottom cover fitting 62 is overlaid on the annular receiving portion 58 of the bracket main body 52, and is overlaid on the lower end portion of the second mounting fitting 14 via the seal rubber 64. The second mounting member 14 is press-fitted and fixed to the bracket member 18, and the seal rubber 64 is compressed and deformed in the axial direction, so that the outer peripheral edge portion of the bottom cover member 62 is connected to the annular receiving portion 58 and the second receiving portion 58. The mounting bracket 14 is clamped and fixed in the axial direction between the lower end portions in the axial direction.

  As a result, the lower opening of the second mounting bracket 14 is covered with the bottom lid bracket 62 in a fluid-tight manner, and on the side opposite to the equilibrium chamber 44 across the diaphragm 34, the fluid tightness with respect to the external space is provided. A sealed air chamber 66 is formed. Therefore, the volume change of the equilibrium chamber 44 is allowed based on the bulging deformation of the diaphragm 34 into the sealed air chamber 66, and the diaphragm 34 is moved into the diaphragm 34 along with the bulging deformation of the diaphragm 34 into the sealed air chamber 66. On the other hand, the air spring of the sealed air chamber 66 is made to act. By utilizing the action of the air spring, for example, the ratio of the static spring to the dynamic spring can be adjusted to tune the spring characteristics.

  Here, as shown in FIG. 6, the partition member 32 according to the present embodiment has a structure in which a rubber elastic film 68 as a movable rubber film can be disposed. That is, the partition member 32 includes a first partition member 70 and a second partition member 72.

  As shown in FIG. 7, the first partition fitting 70 has a thin and substantially disk shape, and a circular through hole 74 is provided through the center portion. In addition, a stepped portion is provided in the radial intermediate portion of the first partition fitting 70, and the outer peripheral portion protrudes in the axial direction (upward in FIG. 1) from the inner peripheral portion. Thereby, the outer peripheral part of the 1st partition metal fitting 70 is made into the shape corresponding to the wall part of the width direction one side (upper in FIG. 1) of the circumferential groove 36. FIG. Further, a communication hole 46 that connects one end of the orifice passage 50 described above to the pressure receiving chamber 42 is provided at one location on the circumference of the first partition fitting 70.

  On the other hand, as shown in FIGS. 8 and 9, the second partition fitting 72 has a thick and substantially disk shape, and the central portion thereof has an axial direction with a predetermined depth dimension. A circular central recess 76 is provided which extends to the end face of one axial direction (upper in FIG. 1). Further, the central part of the second partition fitting 72 is provided with a recess that opens to the other end surface in the axial direction with a depth that does not reach the bottom wall portion of the central recess 76, whereby the second partition fitting The center part of 72 is made into the thin disk shape. A circular-shaped through-hole 78 that is slightly smaller than the disk portion is provided in the disk-shaped portion.

  Moreover, the outer peripheral part of the 2nd partition metal fitting 72 is made into the shape corresponding to the wall part of the bottom wall part of the circumferential groove 36, and the width direction other side (lower in FIG. 1). In other words, in the present embodiment, the substantially other L-shaped cross section in which the other axial end (the lower side in FIG. 1) of the second partition fitting 72 projects axially outward from the axial intermediate portion and the one end. And has a groove shape extending in the circumferential direction with a length of a little less than one round. One end portion in the circumferential direction of the groove-shaped portion 80 (the end portion in the clockwise direction of the groove-shaped portion 80 shown on the lower side in FIG. 8) is connected to the other end portion of the orifice passage 50 described above. A notch-shaped communication hole 48 connected to the equilibrium chamber 44 is provided.

  In particular, in the groove-shaped portion 80 of the second partition fitting 72, a portion where the groove-shaped portion 80 between one end portion in the circumferential direction and the other end portion is not formed so as to rise upward in the axial direction from the outer peripheral edge portion. Thus, a thin plate-like support plate portion 82 is integrally formed. Since the support plate portion 82 continuously extends along the outer peripheral edge portion of the second partition fitting 72 between the one end portion and the other end portion of the groove-like portion 80 along the outer peripheral edge portion, the support plate portion 82 as a whole is a substantially arc plate. It has a shape. In addition, the upper end portion of the support plate portion 82 is set to be substantially the same height as the upper end portion of the second partition fitting 72.

  At a location where the groove-shaped portion 80 between the both ends of the groove-shaped portion 80 of the second partition fitting 72 is not formed, the support plate portion 82 and the radial intermediate portion of the outer peripheral portion have a predetermined distance in the radial direction. By being opposed to each other, a circumferential groove 84 is formed which opens at the upper end of the second partition fitting 72 and continuously extends in a substantially constant rectangular cross section in the circumferential direction. The circumferential grooves 84 allow both ends in the circumferential direction of the groove-shaped portion 80 to communicate with each other.

  Further, a radial groove 86 is provided in a portion of the second partitioning metal 72 that is opposed to the support plate portion 82 in the radial direction across the circumferential groove 84. The radial groove 86 extends in the radial direction of the second partition member 72, and has one end portion guided to the central recess 76 and the other end portion guided to the circumferential groove 84. In particular, in the present embodiment, the width dimension of the radial groove 86 is gradually increased from the radially inner side to the outer side.

  The first partition member 70 and the second partition member 72 are overlapped in the axial direction and are positioned on the concentric shaft. Further, the communication hole 46 of the first partition fitting 70 is aligned with the circumferential end opposite to the circumferential end where the communication hole 48 of the second partition fitting 72 is formed in the circumferential direction. Thereby, the partition member 32 is configured, and the outer peripheral portion of the first partition fitting 70 and the groove-shaped portion 80 of the second partition fitting 72 cooperate to form the circumferential groove 36, and the circumferential groove 36 is the first groove. The orifice passage 50 is configured by being covered with the second mounting bracket 14. A rubber elastic film 68 is disposed between the first partition member 70 and the second partition member 72.

  As shown in FIGS. 10 to 11, the rubber elastic film 68 has a thin and substantially disk shape and is formed using a rubber elastic material. A pair of elastic protrusions 88 and 88 projecting on both sides in the axial direction are integrally formed on the outer peripheral edge of the rubber elastic film 68. Each elastic protrusion 88 has a substantially constant rectangular cross section and extends continuously over the entire circumference in the circumferential direction. By the pair of elastic protrusions 88, 88, the thickness of the outer peripheral portion of the rubber elastic film 68 is made larger than that of the central portion. In particular, the thickness dimension of the outer peripheral portion of the rubber elastic film 68 is such that the peripheral portion of the through hole 74 of the first partition fitting 70 and the peripheral portion of the through hole 78 of the second partition fitting 72 (the bottom wall portion of the central recess 76). It is slightly larger than the axial separation distance. The outer diameter of the rubber elastic film 68 is substantially the same as the outer diameter of the central recess 76 of the second partition fitting 72.

  Such a rubber elastic film 68 is fitted in the central recess 76 of the second partition fitting 72, and the outer peripheral portion including the elastic protrusion 88 of the rubber elastic film 68 is the peripheral portion of the through hole 74 of the first partition fitting 70. And the peripheral edge of the through-hole 78 of the second divider 72 are sandwiched over the entire circumference. Based on the fact that the first partition member 70 and the second partition member 72 are overlapped in the axial direction and assembled to the mount body, the outer peripheral portion of the rubber elastic film 68 is the first partition member 70 and the second partition member 72. The through hole 74 of the first partition member 70 and the through hole 78 of the second partition member 72 are covered with a rubber elastic film 68 in a fluid-tight manner.

  As a result, the rubber elastic film 68 is disposed in the central portion of the partition member 32, and the pressure of the pressure receiving chamber 42 is exerted on one surface of the rubber elastic film 68, and the equilibrium chamber is formed on the other surface of the rubber elastic film 68. The pressure fluctuation absorbing mechanism is configured to absorb the pressure of the pressure receiving chamber 42 based on the elastic deformation of the rubber elastic film 68. In particular, in the present embodiment, the natural frequency of the rubber elastic film 68 is tuned to a high-frequency vibration frequency range of about 80 to 100 Hz corresponding to, for example, traveling boom noise.

  In this case, the first partition fitting 70 is superimposed on the upper end portion of the second partition fitting 72 and the upper end portion of the support plate portion 82 so that the circumferential groove 84 of the second partition fitting 72 is the first partition fitting 70. Thus, the short-circuit channel 90 is formed. The short-circuit channel 90 includes a communication hole 46 of the first partition fitting 70 in which one end in the circumferential direction of the orifice passage 50 is connected to the pressure receiving chamber 42 and a second end in which the other end in the circumferential direction is connected to the equilibrium chamber 44. It is formed between the communication holes 48 of the partition fitting 72 and extends between them in the circumferential direction. In short, in the present embodiment, in addition to the short-circuit channel 90 being formed separately from the orifice passage 50, one end of the short-circuit channel 90 passes through one communication hole 48 of the orifice channel 50. 42, and the other end of the short-circuit channel 90 communicates with the equilibrium chamber 44 through the other communication hole 48 of the orifice passage 50.

  Further, the radial groove 86 formed in the second partition fitting 72 is also fluid-tightly covered with the first partition fitting 70, thereby forming a valve body accommodating portion 92. In the present embodiment, the radially outer peripheral wall portion of the valve body housing portion 92 is configured to include the support plate portion 82 that functions as the width direction wall portion of the short-circuit channel 90. 92 includes a part of the short-circuit channel 90 substantially.

  In such a valve body accommodating portion 92, a rubber valve 94 as an elastic valve is accommodated and disposed. In particular, the rubber valve 94 is integrally formed with the rubber elastic film 68. The rubber valve 94 protrudes from one place on the outer peripheral edge of the rubber elastic film 68 toward the inside of the valve body housing portion 92, and has a substantially rectangular flat plate shape as a whole. The dimension of the rubber valve 94 in the axial direction (right in FIG. 11) is substantially the same as the thickness dimension of the outer peripheral portion provided with the pair of elastic protrusions 88, 88 of the rubber elastic film 68. Further, in this embodiment, the width dimension of the rubber valve 94 is set to 2/3 or less of the width dimension of the valve body accommodating portion 92, and is smaller than the width dimension of the valve body accommodating portion 92. .

  Further, the radially outward projecting dimension of the rubber valve 94 is slightly larger than the diameter dimension of the valve body accommodating portion 92. Thereby, the rubber valve 94 arranged in the valve body housing portion 92 is elastic against the support plate portion 82 constituting a part of the radially outer wall portion of the valve body housing portion 92. It is pressed with the allowance due to. Further, since the axial dimension of the rubber valve 94 is substantially the same as the thickness dimension of the outer peripheral portion provided with the pair of elastic protrusions 88, 88 of the rubber elastic film 68, the axial direction of the valve body accommodating section 92 is It is almost the same as the dimensions. In particular, when the axial dimension of the rubber valve 94 is larger than that of the valve body housing portion 92, the rubber valve 94 is pressed between the first partition fitting 70 and the second partition fitting 72 with an elastic tightening margin. It is like that. As a result, the short-circuit channel 90 covers a part of the valve body accommodating portion 92 in the circumferential direction, and is held in a state in which the pressure receiving chamber 42 and the equilibrium chamber 44 are shut off. As is clear from the above description, the valve seat provided in the valve body accommodating portion 92 of the short-circuit channel 90 is constituted by a portion where the protruding tip portion of the rubber valve 94 in the support plate portion 82 is pressed.

  This elastic tightening allowance is changed according to the shape, size, structure, etc. of the rubber valve 94 and the valve body accommodating portion 92. In this embodiment, the engine shake in the tuning frequency range of the orifice passage 50 is used. Under the normal vibration input, the deformation of the rubber valve 94 is suppressed and the shut-off state of the short-circuit channel 90 is maintained.

  Further, when an excessive negative pressure is generated in the pressure receiving chamber 42 due to a large amplitude vibration being input, such as over a step or running on a speed breaker, the negative pressure generated in the pressure receiving chamber 42 The rubber valve 94 is elastically deformed in the circumferential direction so as to open the short-circuit channel 90 based on the pressure difference between the balance valve 44 and the equilibrium chamber 44, and the elasticity of the rubber valve 94 is set so that the short-circuit channel 90 is in communication. The tightening allowance by is set. After the pressure receiving chamber 42 and the equilibrium chamber 44 are communicated with each other through the short-circuit channel 90 and the excessive negative pressure state of the pressure receiving chamber 42 is eliminated, the pressure difference between the pressure receiving chamber 42 and the equilibrium chamber 44 is small. Accordingly, the elasticity of the rubber valve 94 is utilized to return the rubber valve 94 to a state of pressing the support plate portion 82 of the short-circuit channel 90, and the shut-off state of the short-circuit channel 90 is maintained again.

  In particular, in the present embodiment, the rubber valve 94 integrally formed by projecting radially outward from the outer peripheral portion of the rubber elastic film 68 is gradually reduced in width from the projecting tip portion to the base end portion. Thereby, the cross-sectional area of the protruding tip portion of the rubber valve 94 is made larger than the cross-sectional area of the base end portion, and the protruding tip portion having such a large cross-sectional area is provided in the valve seat ( A contact valve portion 96 that contacts the support plate portion 82) to open and close the short-circuit channel 90, while a base end portion having a small cross-sectional area is an elastic deformation portion 98 that bears the main elastic deformation of the rubber valve 94; Has been. Note that the most distal portion of the contact valve portion 96 has a semicircular cross section viewed in the axial direction for the purpose of reducing wear during contact with the support plate portion 82 and improving durability.

  In the automobile engine mount 10 having the above-described structure, a pressure fluctuation with a relatively large amplitude is induced in the pressure receiving chamber 42 when a low frequency large amplitude vibration such as an engine shake is input. At this time, the pressure variation in the pressure receiving chamber 42 is large, and the structure is difficult to be absorbed by the elastic deformation of the rubber elastic film 68. On the other hand, even if the input of the low frequency large amplitude vibration is not so large as to generate an excessive negative pressure in the pressure receiving chamber 42, based on the tightening allowance due to elasticity to the support plate portion 82 of the rubber valve 94, The shut-off state of the short-circuit channel 90 is maintained. Thereby, the pressure absorption of the pressure receiving chamber 42 due to the elastic deformation of the rubber elastic film 68 is suppressed, and the pressure leakage due to the communication state of the short-circuit channel 90 is suppressed, so that the fluid flow amount through the orifice passage 50 is sufficiently secured. Therefore, the desired vibration isolation effect (high damping effect) can be stably obtained based on the fluid action such as the resonance action of the fluid.

  Further, when high-frequency small-amplitude vibration such as traveling noise is input, the orifice passage 50 tuned to a lower frequency range has a significantly increased fluid flow resistance due to an anti-resonant action, and is substantially in a closed state. Even if this is done, the hydraulic pressure absorption function due to the elastic deformation of the rubber elastic film 68 works, and the pressure fluctuations in the pressure receiving chamber 42 are absorbed, so that the orifice passage 50 is substantially blocked. High dynamic springs are avoided. Therefore, a good anti-vibration effect (vibration insulation effect based on low dynamic spring characteristics) against high-frequency small-amplitude vibration is exhibited. Note that the state of communication / interruption of the short-circuit channel 90 at the time of vibration input with high frequency and small amplitude is not particularly limited, but at such small amplitude, the pressure difference between the pressure receiving chamber 42 and the equilibrium chamber 44 is relatively small. Since the rubber valve 94 is not easily elastically deformed, it is generally in a shut-off state.

  In particular, when the vehicle travels on a speed breaker, a rough road surface, or the like, excessive pressure fluctuations may be caused in the pressure receiving chamber 42 and a large negative pressure may be generated near the opening of the orifice passage 50.

  Therefore, the force that elastically deforms the rubber valve 94 based on the pressure difference between the negative pressure generated in the pressure receiving chamber 42 and the equilibrium chamber 44 presses the rubber valve 94 against the support plate portion 82 of the valve body housing portion 92 and short-circuits. When it becomes larger than the tightening force due to the elastic force of the rubber valve 94 that can hold the flow path 90 in the closed state, the rubber valve 94 Against the tightening force, it is elastically deformed in the circumferential direction toward the communication hole 46 on the pressure receiving chamber 42 side, the short-circuit channel 90 is brought into communication, and the pressure-receiving chamber 42 and the equilibrium chamber 44 are connected through the short-circuit channel 90. As a result, the over-negative pressure state of the pressure receiving chamber 42 is eliminated.

  In particular, in the present embodiment, an elastic deformation portion 98 having a small cross-sectional area is provided at the base end portion of the rubber valve 94, while a contact valve portion 96 having a large cross-sectional area is provided at the tip portion of the rubber valve 94. Thus, a relatively large moment with the base end portion as a base point is set. Accordingly, when an excessive negative pressure is generated in the pressure receiving chamber 42, the rubber valve 94 is efficiently elastically deformed in the circumferential direction, and the over negative pressure state of the pressure receiving chamber 42 can be quickly eliminated.

  Therefore, since the occurrence of cavitation due to the overnegative pressure state of the pressure receiving chamber 42 is suppressed, the occurrence of shocking abnormal noise and vibration associated with the burst of the cavitation bubbles is advantageously suppressed.

  Thus, in the automobile engine mount 10 according to the present embodiment, the orifice passage 50 and the short-circuit passage 90 are separated from each other, so that the fluid flow action through the orifice passage 50 can cause a short-circuit flow. The direct influence of the communication / blocking state of the road 90 is reduced.

  Further, since the rubber valve 94 for opening and closing the short-circuit channel 90 is formed integrally with the rubber elastic film 68, the number of parts is reduced and the body larger than the rubber elastic film 68 is selected when selecting the material of the rubber valve 94. It is not affected by the tuning of the spring characteristics of the rubber elastic body 16.

  Moreover, since the elastic protrusions 88 and 88 are integrally formed on the outer peripheral portion of the rubber elastic film 68 and are sandwiched and fixed between the first partition fitting 70 and the second partition fitting 72 by a large axial force, The elastic deformation of the rubber valve 94 protruding from the outer peripheral portion is less affected by the deformation of the rubber elastic film 68. That is, the reliability of the opening / closing operation of the rubber valve 94 is improved.

  Therefore, a structure capable of obtaining excellent vibration isolation performance based on the stable opening / closing operation of the rubber valve 94 is realized at a low cost by reducing the number of parts, and also from this, for the automobile according to the present embodiment. It is clear that the engine mount 10 is advantageously applied to the technical field of fluid-filled vibration damping devices for automobiles.

  As mentioned above, although embodiment of this invention was explained in full detail, this is one embodiment to the last, Comprising: It is understood that it is not limitedly interpreted by the specific description in embodiment which this invention concerns. Should be. In the following, another specific example of the fluid-filled vibration isolator having a structure according to the present invention will be described. In the following description, members and parts having substantially the same structure as the above-described embodiment will be described with reference to FIG. By attaching the same reference numerals as those in the above embodiment, detailed description thereof will be omitted.

  For example, the shape, size, structure, number, arrangement, and the like of the rubber elastic film 68, the rubber valve 94, the short-circuit channel 90, the valve body accommodating portion 92, and the like according to the above embodiment are required for manufacturability and vibration isolation performance. The setting is appropriately changed according to the above, and is not limited to the example.

  Specifically, for example, as shown in FIG. 12, the communication hole 100 is formed in a portion of the second partition member 72 that is opposed to the communication hole 46 of the first partition member 70 in the axial direction, A short-circuit channel 90 extending in the axial direction is formed between the communication holes 46 and 100, that is, the short-circuit channel 90 is formed so as to penetrate the partition member 32 in the thickness direction, and is integrally formed with the rubber elastic film 68. A structure in which the rubber valve 94 is opened and closed based on elastic deformation in the thickness direction of the partition member 32 in the valve body accommodating portion 92 provided on the short-circuit channel 90 is employed. May be.

  In particular, as shown in FIG. 12, the rubber valve 94 has a cross-sectional shape inclined from the pressure receiving chamber 42 side toward the equilibrium chamber 44 side, so that the rubber valve 94 is elastically deformed in a normal pressure fluctuation in the pressure receiving chamber 42. It is possible to suppress the pressure leakage through the short-circuit channel 90 of the pressure receiving chamber 42 in the normal pressure fluctuation region.

  In the above embodiment, one rubber valve 94 and one corresponding short-circuit channel 90 are provided. However, for example, two or more rubber valves 94 can be provided apart from each other in the circumferential direction. It is also possible to eliminate the overnegative pressure in the pressure receiving chamber 42 more quickly using this short-circuit structure.

  Furthermore, in the above-described embodiment, one orifice passage 50 is provided. However, by providing two or more orifice passages and tuning to different frequency ranges, vibration prevention for a plurality of or a wide frequency range is provided. You may make it acquire an effect.

  Further, the bracket metal fitting 18 is for fixing the mount 10 to the automobile body, and its shape and the like are not particularly limited. For example, instead of the fixed leg 54 as illustrated, the bracket main body 52 is used. The fixed leg portion may be configured by welding and fixing a plurality of leg portions to the outer peripheral surface of the base plate.

  Further, the sealed air chamber 66 and the bottom cover fitting 62 are not essential constituent requirements. It is also possible to connect the external air line to the sealed air chamber 66 by, for example, forming a through port in the bottom lid fitting 62. By providing such an external conduit, the air pressure in the sealed air chamber 66 can be adjusted or controlled later by an external operation.

  In addition, in the above-described embodiment, a specific example of applying the present invention to an engine mount of an automobile has been described. However, the present invention is applied to a vibration isolator for various vibrating bodies other than an automobile in addition to a body mount and a differential mount. Needless to say, both are applicable.

It is a longitudinal cross-sectional view of the engine mount for motor vehicles as one Embodiment of this invention, Comprising: The figure corresponded to each II cross section of FIG. The longitudinal cross-sectional view of the 1st integral vulcanization molded product which comprises a part of engine mount for the vehicles. The longitudinal cross-sectional view of the 2nd integral vulcanization molded product which comprises a part of engine mount for the vehicles. The longitudinal cross-sectional view of the bracket metal fitting which comprises a part of engine mount for the vehicles. The longitudinal cross-sectional view of the bottom cover metal fitting which comprises a part of engine mount for the vehicles. The top view which shows the state which assembled | attached the rubber elastic film to the partition member which comprises some engine mounts for the said cars. The top view which shows the 1st partition metal fitting which comprises a part of the partition member. The top view which shows the state which assembled | attached the rubber elastic film to the 2nd partition metal fitting which comprises a part of the partition member. IX-IX sectional drawing of FIG. The top view of the rubber elastic membrane. XI-XI sectional drawing of FIG. The longitudinal cross-sectional view which shows the principal part of the engine mount for motor vehicles as another specific example of this invention.

Explanation of symbols

10: Engine mount for automobile, 12: First mounting bracket, 14: Second mounting bracket, 16: Rubber elastic body, 32: Partition member, 34: Diaphragm, 42: Pressure receiving chamber, 44: Equilibrium chamber, 50 : Orifice passage, 68: Rubber elastic membrane, 82: Support plate part, 90: Short circuit flow path, 92: Valve body accommodating part, 94: Rubber valve

Claims (6)

The first mounting member and the second mounting member are connected by the main rubber elastic body, and the partition member is supported by the second mounting member, and a part of the wall portion is on both sides of the partition member. A pressure receiving chamber made of a rubber elastic body and an equilibrium chamber in which a part of the wall part is made of a flexible film are formed, and an incompressible fluid is sealed in the pressure receiving chamber and the equilibrium chamber, and the partition An orifice passage that allows the pressure receiving chamber and the equilibrium chamber to communicate with each other is formed in the outer peripheral portion of the member, and a movable rubber film is disposed in the central portion of the partition member, and the pressure receiving pressure is provided on one surface of the movable rubber film In a fluid-filled vibration isolator configured as a pressure fluctuation absorbing mechanism so that the pressure of the chamber is exerted and the pressure of the equilibrium chamber is exerted on the other surface of the movable rubber film,
A short-circuit channel is formed separately from the orifice passage on the outer peripheral side of the movable rubber film in the partition member, and an elastic valve is formed integrally with the movable rubber film so that the elastic valve is formed on the outer peripheral surface of the movable rubber film. And by projecting the elastic valve in the short-circuit channel to form the valve body housing portion and pressing the elastic valve against the valve seat provided in the valve body housing portion with an elastic tightening margin. The short-circuit channel is held in a shut-off state, and the short-circuit channel is brought into a communication state by elastic deformation of the elastic valve based on a pressure difference between the negative pressure generated in the pressure receiving chamber and the equilibrium chamber. A fluid-filled vibration isolator characterized by the above.   The outer circumferential portion of the partition member extends in the circumferential direction with a length shorter than one circumference in the circumferential direction, and one circumferential end thereof communicates with the pressure receiving chamber and the other circumferential end communicates with the equilibrium chamber through communication holes. Thus, the orifice passage is formed and extends in the circumferential direction at a portion where the orifice passage is not formed between one end and the other end in the circumferential direction of the orifice passage. The fluid-filled type vibration damping device according to claim 1, wherein the short-circuit channel is formed.   One end of the short-circuit channel is communicated with the pressure receiving chamber through one communication hole of the orifice passage, and the other end of the short-circuit channel is communicated with the equilibrium through the other communication hole of the orifice channel. The elastic valve is arranged to open and close the short-circuit channel based on elastic deformation in the circumferential direction of the partition member in the valve body housing portion provided on the short-circuit channel while communicating with the chamber. The fluid-filled vibration isolator according to claim 2.   The short-circuit channel is formed through the partition member in the thickness direction, and the elastic valve is elastically deformed in the thickness direction of the partition member in the valve body housing portion provided on the short-circuit channel. The fluid-filled vibration damping device according to claim 2, wherein the fluid-filled vibration damping device is arranged so as to open and close the short-circuit flow path.   The elastic valve integrally protruding and projecting from the movable rubber film has a smaller cross-sectional area at the base end portion on the movable rubber film side than the projecting distal end portion, and the projecting distal end portion is connected to the short-circuit channel. The contact valve part which contacts the said valve seat provided and opens and closes this short circuit flow path is provided, and the elastic deformation part is provided in the base end part. The fluid-filled vibration isolator according to the item.   Applied to an automobile engine mount, the orifice passage is tuned so as to exhibit a damping effect in a frequency range corresponding to an engine shake input when the vehicle travels, and the vibration of the engine shake in which the orifice passage functions The fluid filled type vibration damping device according to any one of claims 1 to 5, wherein a tightening margin is set by elasticity of the elastic valve so that the short-circuit channel is maintained in a shut-off state at the time of input.

Images