JP5882124B2 - Liquid-filled vibration isolator - Google Patents

Description

  The present invention relates to a liquid-filled vibration isolator.

  As an anti-vibration device such as an engine mount that supports the vibration of a vibration source such as an automobile engine so as not to be transmitted to the vehicle body side, a first attachment attached to the vehicle body side, a second attachment attached to the vibration source side, An anti-vibration base made of a rubber-like elastic body interposed between the fixtures, a main liquid chamber in which the anti-vibration base forms part of the chamber wall, and a sub-liquid chamber in which the diaphragm forms part of the chamber wall; A liquid-filled vibration isolator having an orifice channel for communicating between these liquid chambers is known. In such a liquid-filled vibration isolator, a vibration damping function and a vibration insulating function are achieved by a liquid column resonance effect caused by a liquid flow in the orifice channel and a vibration damping effect of the vibration isolating substrate.

  As this type of liquid-filled vibration isolator, Patent Document 1 below discloses the following configuration in order to reduce cavitation in the liquid chamber. Here, cavitation means that when a large vibration is input to the vibration isolator, the orifice flow path is clogged, so that the main liquid chamber is in an excessively negative pressure state (that is, the liquid pressure in the main liquid chamber is a predetermined value). This is a phenomenon that occurs when a large number of bubbles are generated by lowering the saturated vapor pressure of the sealed liquid. Then, when the generated bubbles disappear, the impact sound becomes an abnormal noise and is transmitted to the outside, so that the vibration isolator itself becomes an abnormal noise generation source. In Patent Document 1, in order to suppress an excessive negative pressure state of the main liquid chamber that causes cavitation, the high-frequency second orifice channel connecting the main liquid chamber and the sub liquid chamber is moved to the main liquid chamber. A second diaphragm having a valve function is provided at the opening. In the normal use region of the vibration isolator, the opening is closed by the flexible membrane portion of the second diaphragm, and the flexible membrane portion bends away from the opening toward the main liquid chamber when large amplitude is input. By deforming, the liquid is supplied from the through hole provided in the flexible film part to the main liquid chamber side.

  In Patent Document 2 below, in order to suppress an excessive positive pressure state of the main liquid chamber, a high-frequency second orifice channel connecting the main liquid chamber and the sub liquid chamber is provided at the opening to the sub liquid chamber. A configuration in which a second diaphragm having a valve function is provided is disclosed. In the normal use region, the flexible membrane portion of the second diaphragm closes the opening, and at the time of large amplitude input, the flexible membrane portion is bent and deformed so as to be separated from the opening toward the sub liquid chamber side. The liquid is supplied from the through hole provided in the flexible membrane part to the sub liquid chamber side.

  In addition, in Patent Document 3 below, in order to suppress an excessive positive pressure state of the main liquid chamber, a thick-walled valve portion in which a through hole is formed in a part of the elastic partition membrane is provided. A configuration is disclosed in which a through hole is provided in the holding member on the side of the secondary liquid chamber while being held in close contact with the upper and lower holding members.

  In these conventional liquid-filled vibration isolators, either the excessive negative pressure state in the main liquid chamber is relieved or the excessive positive pressure state is relieved, the excessive negative pressure state and the positive pressure state It does not have a bi-directional valve function that can alleviate both.

JP 2011-149492 A JP 2011-149493 A JP 2010-106976 A

  It is an object of the present invention to provide a liquid-filled vibration isolator having a bidirectional valve function that can relieve both a negative pressure state and a positive pressure state of a main liquid chamber.

  The liquid-filled vibration isolator according to the present invention includes a first fixture, a second fixture, and a rubber-like elastic body interposed between the first fixture and the second fixture. A vibration base, a first diaphragm made of a rubber-like elastic body attached to the first fixture, and a liquid enclosure formed between the vibration-proof base and the first diaphragm inside the first fixture A partition that divides the chamber into a main liquid chamber on the vibration-isolating substrate side and a first sub liquid chamber on the first diaphragm side, and connects the main liquid chamber and the first sub liquid chamber A first orifice channel. The partition body is tuned to a higher frequency range than the first sub-fluid chamber, the second sub-liquid chamber, the second sub-liquid chamber, the second sub-liquid chamber, A second orifice channel connecting the two, a partition wall between the other of the main liquid chamber and the first sub liquid chamber and the second sub liquid chamber, and the outer peripheral portion being liquid tight with respect to the partition body A second diaphragm made of a rubber-like elastic body that is held; a first opposing wall that faces one of the membrane surfaces of the second diaphragm and forms a part of a chamber wall of the main liquid chamber; and the second diaphragm A second opposing wall that opposes the other film surface and forms part of the chamber wall of the first sub-liquid chamber. The second diaphragm is provided with at least one first through hole and at least one second through hole. The first through hole and the second through hole are separated from each other by a valve portion that protrudes from the front and back surfaces of the second diaphragm and contacts the first opposing wall and the second opposing wall in a liquid-tight state. Yes. The first through hole is provided in communication with the main liquid chamber through a first communication hole provided in the first opposing wall, and the second through hole is provided in the second opposing wall. A communication hole is provided in communication with the first auxiliary liquid chamber.

  In one aspect of the present invention, the first through hole and the second through hole are liquid-tightly isolated from the second sub liquid chamber by the valve portion. In another aspect, the valve portion is configured to open a liquid-tight state with respect to the first opposing wall and the second opposing wall by bending deformation of the second diaphragm. In still another aspect, the valve portion is provided in a cylindrical shape surrounding each of the first through hole and the second through hole. In still another aspect, an opening to the second sub-liquid chamber of the second orifice channel is provided at a position facing a central portion of the second diaphragm, and the second diaphragm has a central portion. Around the periphery, the first through hole and the second through hole are provided. In yet another aspect, the second orifice channel connects the main liquid chamber and the second sub liquid chamber, and the second diaphragm includes the first sub liquid chamber and the second sub liquid chamber. Make a partition wall. The above aspects can be combined as appropriate.

  According to the present invention, when the second diaphragm deforms more than a predetermined amount toward the first opposing wall, the liquid tight state of the valve portion with respect to the second opposing wall is released, so that the first sub liquid chamber is The liquid can be supplied to the main liquid chamber through the through hole and the first communication hole, and the negative pressure state of the main liquid chamber can be relaxed. Further, when the second diaphragm is bent or deformed more than a predetermined amount toward the second facing wall, the liquid tight state of the valve portion with respect to the first facing wall is released, so that the second through hole and the second communication hole are opened from the main liquid chamber. The liquid can be supplied to the first sub liquid chamber through the hole, and the positive pressure state of the main liquid chamber can be relaxed. In this way, liquid leakage between the main liquid chamber and the first sub liquid chamber is generated with respect to the movement of the second diaphragm in both directions, and the valve function in both directions can be exhibited.

It is a longitudinal cross-sectional view of the liquid filled type vibration isolator which concerns on 1st Embodiment. It is sectional drawing of the partition part in the embodiment. It is a figure of the partition body in the embodiment, (a) is a top view, (b) is the IIIB-IIIB sectional view taken on the line, (c) is a bottom view. (A) is a top view of the 2nd diaphragm in the embodiment, (b) is the IVB-IVB sectional view taken on the line, (c) is the IVC-IVC sectional view. It is a longitudinal cross-sectional view in the normal use area | region of the partition, (a) at the time of the flow of the liquid from a main liquid chamber to a 1st sub liquid chamber, (b) is from a 1st sub liquid chamber to a main liquid chamber. Indicates when liquid is flowing. It is a longitudinal cross-sectional view at the time of the large amplitude input of the partition, (a) is a liquid flow from the main liquid chamber to the first sub liquid chamber, (b) is from the first sub liquid chamber to the main liquid chamber. The flow of liquid is shown. It is a figure of the partition body which concerns on 2nd Embodiment, (a) is a top view, (b) is the VIIB-VIIB sectional view taken on the line, (c) is a bottom view. (A) is a top view of the 2nd diaphragm which concerns on 2nd Embodiment, (b) is the VIIIB-VIIIB sectional view taken on the line, (c) is a VIIIC-VIIIC sectional view taken on the line. It is a longitudinal cross-sectional view of the liquid filled type vibration isolator which concerns on 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a longitudinal sectional view of a liquid-filled vibration isolator 10 according to the first embodiment. The vibration isolator 10 is an engine mount that supports an automobile engine, and includes a lower first mounting member 12 that forms a cylindrical shape that is attached to a support-side vehicle body, and an upper side that is attached to an engine side that is a vibration source. The second fixture 14 is provided with a vibration-proof base 16 made of a rubber elastic body that is interposed between the fixtures 12 and 14 and connects them. FIG. 1 shows a no-load state.

  The 2nd fixture 14 is the boss | hub metal fitting distribute | arranged above the axial center part of the 1st fixture 12, and the stopper part 18 which protrudes in a flange shape toward radial direction outward is formed. Moreover, the bolt hole 20 is provided in the upper end part, and it is comprised so that it may attach to an engine side via a volt | bolt not shown.

  The first fixture 12 is composed of a cylindrical fitting 22 in which the vibration-proof base 16 is vulcanized and a cup-like bottom fitting 24, and downward mounting bolts 26 project from the bottom fitting 24. It is comprised so that it may attach to the vehicle body side via. The lower end of the cylindrical fitting 22 is fixed by caulking to the upper end opening of the bottom fitting 24 by a caulking portion 28. Reference numeral 30 denotes a stopper fitting fixed by caulking to the upper end portion of the cylindrical fitting 22, and exerts a stopper action with the stopper portion 18 of the second fixture 14. Reference numeral 32 denotes a stopper rubber that covers the upper surface of the stopper fitting 30.

  The anti-vibration base 16 is formed in an umbrella shape, and its upper end is vulcanized and bonded to the second fixture 14 and its lower end is vulcanized and bonded to the upper end opening of the cylindrical fitting 22. A rubber layer 34 that covers the inner peripheral surface of the cylindrical metal fitting 22 is connected to the lower end portion of the vibration isolation base 16.

  The first fixture 12 includes a first diaphragm 38 made of a flexible rubber film that is disposed to face the lower surface of the vibration-isolating base 16 in the axial direction X and forms a liquid sealing chamber 36 between the lower surface. A liquid enclosure chamber 36 is filled with a liquid such as water, ethylene glycol, or silicone oil. The first diaphragm 38 includes an annular reinforcing metal fitting 39 on the outer peripheral portion, and is fixed to the caulking portion 28 via the reinforcing metal fitting 39.

  The liquid sealing chamber 36 provided inside the first fixture 12 is divided into a main liquid chamber 42 on the side of the vibration isolation base 16 (that is, the upper side) and a first diaphragm 38 side (that is, the lower side) by the partition body 40. ) First sub-liquid chamber 44. The main liquid chamber 42 is a liquid chamber in which the vibration isolation base 16 forms part of the chamber wall, and the first sub-liquid chamber 44 is a liquid chamber in which the first diaphragm 38 forms part of the chamber wall. An air chamber 46 is provided on the lower side of the first diaphragm 38 inside the bottom metal fitting 24. Therefore, the first diaphragm 38 is a diaphragm that forms a partition wall between the first sub liquid chamber 44 and the air chamber 46. is there.

  The partition body 40 is fitted on the inner side of the first fixture 12 via the rubber layer 34. A ring-plate-shaped partition receiving plate 48 is disposed in contact with the lower surface of the partition body 40. The partition receiving plate 48 is fixed together with the reinforcing metal fitting 39 of the first diaphragm 38 by the caulking portion 28, thereby separating the partition. The body 40 is held in a state of being sandwiched in the axial direction X between the step portion 34 </ b> A provided in the rubber layer 34 and the partition receiving plate 48.

  The main liquid chamber 42 and the first sub liquid chamber 44 are connected to each other via a first orifice channel 50 which is a throttle channel. In this example, the first orifice channel 50 is a low frequency side orifice tuned to a low frequency range (for example, about 5 to 15 Hz) corresponding to the shake vibration in order to attenuate the shake vibration during vehicle travel. That is, tuning is performed by adjusting the cross-sectional area and length of the flow path so that the damping effect based on the resonance action of the liquid flowing through the first orifice flow path 50 is effectively exhibited when the shake vibration is input. .

  The first orifice channel 50 is provided on the outer periphery of the partition body 40. Specifically, a circumferential direction C (FIG. 3 (a)) is formed between the rubber layer 34 and the first orifice forming groove 52 (see FIG. 2) that is provided on the outer periphery of the partition body 40 and opens outward. A first orifice channel 50 is formed extending in (). As shown in FIG. 3, the first orifice passage 50 includes a main liquid chamber side opening 50 </ b> A that opens to the main liquid chamber 42 at one end in the circumferential direction C, and a first end at the other end in the circumferential direction C. A secondary liquid chamber side opening 50 </ b> B that opens to the secondary liquid chamber 44 is provided.

  As shown in FIG. 2, the partition body 40 includes a partition body main body 54 made of a rigid material such as resin or metal, and a second diaphragm 56 made of a rubber elastic body incorporated in the partition body main body 54. It is a composite member. In this example, the partition body 54 is provided with a body member 60 having a first orifice forming groove 52 on the outer periphery and a stepped recess 58 opened toward the main liquid chamber 42 side, and the stepped recess. The lid member 62 is internally fitted and fixed to 58.

  The partition body 40 includes a second sub liquid chamber 64, a second orifice channel 66 that is a throttle channel connecting the second sub liquid chamber 64 and the main liquid chamber 42, and the second sub liquid chamber 64. A second diaphragm 56 that forms a partition wall with the first sub liquid chamber 44, and a first opposing wall 68 that faces one film surface (upper surface) of the second diaphragm 56 and forms part of the chamber wall of the main liquid chamber 42. And a second facing wall 70 that faces the other film surface (lower surface) of the second diaphragm 56 and forms part of the chamber wall of the first sub-liquid chamber 44.

  In the second diaphragm 56, the outer peripheral portion 56A is held in a liquid-tight manner (that is, the liquid does not leak) with respect to the partition body 40, and a flexible membrane portion 56B is provided on the inner side of the outer peripheral portion 56A. Become. Specifically, as shown in FIG. 4, the second diaphragm 56 has a disk shape (circular film shape), and the outer peripheral portion 56A is thick on the entire periphery, and the inner side of the thick outer peripheral portion 56A. Is provided with a circular flexible membrane portion 56B. The second diaphragm 56 is fitted in and fixed to the lid member 62 in a state where the second diaphragm 56 is disposed in the stepped recess 58 of the main body member 60, so that the outer peripheral portion 56 </ b> A is axially disposed between the main body member 60 and the lid member 62. X is sandwiched in a compressed state.

  The second sub liquid chamber 64 is formed between the second diaphragm 56 and the first opposing wall 68, and more specifically, the upper surface of the second diaphragm 56 and the first opposing wall 68 opposed thereto. This is a flat and flat liquid chamber provided between the lower surface and the lower surface. The second sub liquid chamber 64 is partitioned from the first sub liquid chamber 44 via the second diaphragm 56.

  The second orifice channel 66 is a high-frequency side orifice tuned to a higher frequency range than the first orifice channel 50. In this example, in order to reduce idling vibration during idling (when the vehicle is stopped), idling vibration is used. Is tuned to a high frequency range (for example, about 15 to 50 Hz). That is, tuning is performed by adjusting the cross-sectional area and length of the flow path so that the low dynamic spring effect based on the resonance action of the liquid flowing through the second orifice flow path 66 is effectively exhibited when the idle vibration is input. ing.

  The first facing wall 68 is a horizontal wall portion facing the film surface on the main liquid chamber 42 side of the second diaphragm 56 with a space therebetween, and is formed by the lid member 62. The second orifice channel 66 is provided inside a cylindrical portion 72 that is formed to protrude toward the main liquid chamber 42 at the center of the lid member 62 that constitutes the first opposing wall 68. A second diaphragm 56 is disposed below the second orifice channel 66, that is, on the first sub liquid chamber 44 side. Further, the opening 66A of the second orifice channel 66 to the second sub liquid chamber 64 is located at a position facing the central portion 56C of the second diaphragm 56 on the first facing wall 68, as shown in FIG. Is provided. Therefore, the first facing wall 68 is formed so as to face the film surface of the peripheral portion 56D (see FIG. 4A) surrounding the central portion 56C in the flexible film portion 56B of the second diaphragm 56. ing.

  The second facing wall 70 is a horizontal wall portion facing the film surface on the first sub liquid chamber 44 side of the second diaphragm 56 with a space therebetween, as shown in FIGS. 3 (b) and 3 (c). Furthermore, the main body member 60 has a ring plate shape that protrudes radially inward from the inner peripheral surface of the thick outer peripheral portion. The second opposing wall 70 is provided with a circular central through hole 74 at a position facing the central portion 56 </ b> C of the second diaphragm 56. Therefore, the second facing wall 70 is formed so as to face the film surface of the peripheral portion 56D surrounding the central portion 56C in the flexible film portion 56B of the second diaphragm 56.

  The central through hole 74 is an opening provided to make the second diaphragm 56 face the first sub liquid chamber 44 and does not have a throttling effect on the second orifice channel 66. The cross-sectional area (opening area) and length (thickness of the second opposing wall 70) are set. For example, the central through hole 74 has a larger cross-sectional area and a shorter length than the second orifice channel 66.

  The second diaphragm 56 is provided with at least one first through hole 76 and at least one second through hole 78. In this example, the first through-hole 76 and the second through-hole 78 have the same shape and size, and two each are provided, and the peripheral portion 56D in the flexible film portion 56B, that is, the central portion 56C. Are arranged at equal intervals in the circumferential direction C.

  The first through hole 76 and the second through hole 78 are separated from each other by a valve portion 80 that protrudes from both the front and back surfaces of the second diaphragm 56 and contacts the first opposing wall 68 and the second opposing wall 70 in a liquid-tight state. ing. The first through hole 76 and the second through hole 78 are also liquid-tightly isolated from the second sub liquid chamber 64 by the valve portion 80. The valve portion 80 is a seal wall portion that is not bonded to the first opposing wall 68 and the second opposing wall 70 and is in contact with the opposing walls 68 and 70 in a state where there is no gap and seals liquid-tightly. Yes, it is formed of a rubber elastic body integrated with the second diaphragm 56.

  In this example, as shown in FIG. 4, the valve portion 80 is provided in a cylindrical shape surrounding the first through hole 76 and the second through hole 78 separately. Specifically, the valve portion 80 is formed in a cylindrical portion that rises from the upper surface and the lower surface of the flexible film portion 56B at each of the opening peripheral portion of the first through hole 76 and the opening peripheral portion of the second through hole 78. The through-holes 76 and 78 are provided in the hollow portion inside. The cylindrical valve portion 80 has an upper end abutting on the lower surface of the first opposing wall 68 without a gap and a lower end abutting on the upper surface of the second opposing wall 70 without a gap, thereby being surrounded by the valve portion 80. The separated space is liquid-tightly partitioned from the surrounding liquid chamber portion. Therefore, each through hole, that is, the first through hole 76 and the second through hole 78 are separated from each other in a liquid-tight manner, and each of these through-holes 76 and 78 is also separated from the second sub liquid chamber 64 in a liquid-tight manner. Has been.

  The valve portion 80 is held in a state compressed in the axial direction X between the first opposing wall 68 and the second opposing wall 70, and thereby, with respect to the first opposing wall 68 and the second opposing wall 70. It is in liquid-tight condition. Further, the valve portion 80 can open (that is, release) the liquid-tight state with respect to the first opposing wall 68 and the second opposing wall 70 by causing the second diaphragm 56 to bend and deform more than a predetermined amount in the axial direction X. It is configured. That is, as shown in FIG. 6A, the second diaphragm 56 is bent and deformed downward, whereby a gap is formed between the upper end of the valve portion 80 and the first opposing wall 68, thereby the first opposing wall. 68, as shown in FIG. 6B, the second diaphragm 56 is bent upward and deformed, so that the lower end of the valve portion 80 and the second opposing wall 70 A gap is formed between them, so that the liquid-tight state with respect to the second opposing wall 70 is opened.

  It should be noted that the compression amount of the valve portion 80 in the axial direction X is maintained in the liquid-tight state in the normal use region of the vibration isolator 10, but the liquid-tight state is released at the time of large amplitude input in which, for example, cavitation occurs. It may be set so that.

  As shown in FIG. 3, a first communication hole 82 is formed through the first opposing wall 68 at a position corresponding to the first through hole 76, that is, a position overlapping the first through hole 76 when viewed from the axial direction X. In addition, a second communication hole 84 is formed in the second opposing wall 70 at a position corresponding to the second through hole 78, that is, a position overlapping the second through hole 78 when viewed from the axial direction X. . That is, with respect to the first through hole 76, a communication hole is provided only in the first opposing wall 68 out of the first opposing wall 68 and the second opposing wall 70, and Of the first facing wall 68 and the second facing wall 70, only the second facing wall 70 is provided with a communication hole. The 1st communicating hole 82 and the 2nd communicating hole 84 are comprised so that the circumference | surroundings may be surrounded by the corresponding valve part 80, respectively.

  Thus, the first through hole 76 is provided in communication with the main liquid chamber 42 through the first communication hole 82 provided in the first opposing wall 68, and the second through hole 78 is provided in the second opposing wall 70. The second communication hole 84 is provided in communication with the first auxiliary liquid chamber 44. Specifically, in the liquid-tight state with respect to the first opposing wall 68 and the second opposing wall 70 by the valve portion 80, the first through hole 76 is the main liquid chamber 42 of the main liquid chamber 42 and the first sub liquid chamber 44. The second through hole 78 is configured to communicate with only the first sub liquid chamber 44 of the main liquid chamber 42 and the first sub liquid chamber 44.

  In the liquid filled vibration isolator 10 having the above-described configuration, the valve portion of the second diaphragm 56 is used in a normal use region where the hydraulic pressure difference between the main liquid chamber 42 and the first sub liquid chamber 44 is equal to or greater than a specified value. 80 maintains a liquid-tight state with respect to the first opposing wall 68 and the second opposing wall 70, and no liquid leaks between the main liquid chamber 42 and the first sub liquid chamber 44 in the second diaphragm 56. . Specifically, as shown in FIG. 5A, when the liquid flows from the main liquid chamber 42 to the first sub liquid chamber 44 in the normal use region, the main liquid chamber 42 and the first through hole 76 are in the first communication. Although communicating through the hole 82, the lower end of the valve portion 80 is closed by the second opposing wall 70. Therefore, the leakage of the liquid L from the main liquid chamber 42 to the first sub liquid chamber 44 does not occur. As shown in FIG. 5B, when the liquid flows from the first sub liquid chamber 44 to the main liquid chamber 42, the first sub liquid chamber 44 and the second through hole 78 are connected via the second communication hole 84. Although communicating, the upper end of the valve portion 80 is closed by the first facing wall 68. Therefore, the leakage of the liquid L from the first sub liquid chamber 44 to the main liquid chamber 42 does not occur.

  Therefore, with the liquid-filled vibration isolator 10, in the normal use region, when vibration on the low frequency side with a relatively large amplitude, such as shake vibration, is input when the vehicle travels, the liquid in the second diaphragm 56 The liquid flows back and forth between the main liquid chamber 42 and the first sub liquid chamber 44 through the first orifice channel 50 on the low frequency side while preventing leakage, so that the liquid flowing through the first orifice channel 50 Based on the resonance action, high damping performance is exhibited against shake vibration.

  Further, when vibration on the high frequency side with a relatively small amplitude is input, such as during idling when the vehicle is stopped, the second diaphragm 56 is bent and deformed to a small amplitude while maintaining the liquid tight state of the valve unit 80. Therefore, an excellent vibration-proofing effect against idle vibration is exhibited by the resonance action of the liquid through the second orifice channel 66 with respect to the vibration input on the high frequency side.

  On the other hand, the fluid pressure in the main fluid chamber 42 becomes lower than a prescribed value that may cause cavitation, or the fluid pressure in the main fluid chamber 42 becomes larger than a prescribed value, so that the second diaphragm 56 is bent. When the amount of deformation becomes larger than the specified value, the liquid tight state of the valve portion 80 with respect to the first opposing wall 68 and the second opposing wall 70 is released, so that the main liquid chamber 42 and the first sub liquid chamber in the second diaphragm 56 are released. There is a liquid leak with 44.

  Specifically, when a large-amplitude input is generated, such as over a road surface step, and the hydraulic pressure of the main liquid chamber 42 with respect to the first sub-liquid chamber 44 becomes larger than a specified value, it is shown in FIG. As described above, the second diaphragm 56 is deformed more than a predetermined amount toward the second facing wall 70. As a result, the liquid tight state of the valve portion 80 with respect to the first opposing wall 68 is released, so that the first fluid passage 42 passes through the second orifice channel 66, the second through hole 78, and the second communication hole 84. The liquid L can be supplied to the sub liquid chamber 44. Therefore, an excessive positive pressure state of the main liquid chamber 42 can be relieved, and damage due to excessive deformation of the second diaphragm 56 can be prevented.

  Further, when the hydraulic pressure in the main liquid chamber 42 becomes lower than a specified value that may cause cavitation, the second diaphragm 56 is more than a predetermined amount toward the first opposing wall 68 as shown in FIG. Bend and deform. As a result, the liquid tight state of the valve portion 80 with respect to the second opposing wall 70 is released, so that the liquid L is transferred from the first sub liquid chamber 44 to the main liquid chamber 42 through the first through hole 76 and the first communication hole 84. Can be supplied. Therefore, the excessive negative pressure state of the main liquid chamber 42 can be relieved, and the occurrence of cavitation can be suppressed.

  As described above, according to the present embodiment, the main liquid chamber 42 and the first sub liquid chamber 44 can be moved with respect to the movement of the second diaphragm 56 in both directions at the time of large amplitude input while ensuring the vibration isolation performance in the normal use region. A liquid leak can be generated, and an excessive positive pressure state and an excessive negative pressure state of the main liquid chamber 42 can be alleviated.

  In addition, since the valve portion 80 has a cylindrical shape surrounding each of the first through hole 76 and the second through hole 78, the impact due to the contact with the first opposing wall 68 and the second opposing wall 70 is reduced, In the abutted state, the deformation in the axial direction X of the valve portion 80 is allowed and the transmission energy to the partition body 40 can be relaxed. That is, in this case, the transmission energy E to the partition body 40 is expressed by E = E1−E2 where E1 is the kinetic energy of the flexible wall portion 60B that bends and deforms, and E2 is the energy consumed by the deformation of the valve portion 80. Therefore, the energy transmitted to the partition body 40 can be reduced by the amount of energy consumed due to the deformation of the valve portion 80, and the generation of abnormal noise can be suppressed.

  In the present embodiment, the valve portion 80 is provided in a distributed manner at a plurality of locations on the circumference of the flexible membrane portion 56B of the second diaphragm 56, so that the central portion of the flexible membrane portion 56 is provided. Not only 56C but substantially the whole including the peripheral portion 56D can be used as the movable film portion of the second diaphragm 56 in the normal use region. Therefore, the second diaphragm 56 can be easily bent and deformed, and the characteristics of the second orifice channel 66 on the high frequency side can be improved.

[Second Embodiment]
7 and 8 are diagrams relating to the liquid-filled vibration isolator of the second embodiment. In this embodiment, the number of first through holes 76 and second through holes 78 provided in the second diaphragm 56 is different from that in the first embodiment.

  Specifically, as shown in FIG. 8, the second diaphragm 56 is provided with four first through holes 76 and four second through holes 78 with the same shape and size, respectively. The first through holes 76 and the second through holes 78 are alternately arranged in the circumferential direction C at equal intervals in the peripheral portion 56D of the conductive film portion 56B. The first through hole 76 and the second through hole 78 are respectively provided with valve portions 80 similar to those in the first embodiment.

  As shown in FIG. 7, first communication holes 82 are formed through the first opposing wall 68 at four locations corresponding to the first through holes 76, and the second opposing wall 70 includes Second communication holes 84 are formed through four locations corresponding to the second through holes 78. Thus, as in the first embodiment, the first through hole 76 is provided in communication with the main liquid chamber 42 through the first communication hole 82 provided in the first opposing wall 68, and the second through hole 78. Is provided in communication with the first auxiliary liquid chamber 44 through a second communication hole 84 provided in the second facing wall 70.

  About 2nd Embodiment, the other structure is the same as 1st Embodiment, and there exists an effect similar to 1st Embodiment. Thus, the number of the first through holes 76 and the second through holes 78 is not particularly limited as long as it is at least one.

[Third Embodiment]
FIG. 9 shows a liquid-filled vibration isolator 10A according to the third embodiment. This embodiment is different from the first embodiment in that the second diaphragm 56 is disposed on the main liquid chamber 42 side of the second orifice channel 66.

  That is, in the present embodiment, the second orifice channel 66 connects the first sub liquid chamber 44 and the second sub liquid chamber 64, the second diaphragm 56 is disposed on the main liquid chamber 42 side, The two diaphragms 56 form a partition between the main liquid chamber 42 and the second sub liquid chamber 64.

  The second sub-liquid chamber 64 is formed between the second diaphragm 56 and the second opposing wall 70, and more specifically, the lower surface of the second diaphragm 56 and the second opposing wall 70 facing the second diaphragm 56. It is a flat and flat liquid chamber provided between the upper surface and the upper surface. The second sub liquid chamber 64 is partitioned from the main liquid chamber 42 via the second diaphragm 56.

  The second orifice channel 66 is provided inside a cylindrical portion 86 that is formed to protrude toward the first sub-liquid chamber 44 at the center of the second opposing wall 70. Therefore, the opening 66 </ b> A of the second orifice channel 66 to the second sub liquid chamber 64 is provided on the second facing wall 70 at a position facing the central portion 56 </ b> C of the second diaphragm 56. The first opposing wall 68 is provided with a circular central through hole 88 at a position facing the central portion 56 </ b> C of the second diaphragm 56. The central through-hole 88 is an opening provided to make the second diaphragm 56 face the main liquid chamber 42, and the second through-hole 88 does not have a throttling effect on the second orifice channel 66. The cross-sectional area and length are set.

  The configuration of the second diaphragm 56 itself is the same as that of the first embodiment. The first through hole 76 and the second through hole 78 are provided, and the valve unit 80 is provided. Further, similarly to the first embodiment, a first communication hole 82 and a second communication hole 84 are provided in the first counter wall 68 and the second counter wall 70, respectively.

  Thus, the first through hole 76 is provided in communication with the main liquid chamber 42 through the first communication hole 82 provided in the first opposing wall 68, and the second through hole 78 is provided in the second opposing wall 70. The second communication hole 84 is provided in communication with the first auxiliary liquid chamber 44. Specifically, in the liquid-tight state with respect to the first opposing wall 68 and the second opposing wall 70 by the valve portion 80, the first through hole 76 is the main liquid chamber 42 of the main liquid chamber 42 and the first sub liquid chamber 44. The second through hole 78 is configured to communicate with only the first sub liquid chamber 44 of the main liquid chamber 42 and the first sub liquid chamber 44.

  In this embodiment as well, in the normal use region, the valve portion 80 of the second diaphragm 56 maintains a liquid-tight state with respect to the first opposing wall 68 and the second opposing wall 70, so that the main fluid chamber in the second diaphragm 56. There is no leakage of liquid between 42 and the first sub liquid chamber 44. Therefore, high damping performance against shake vibration and excellent vibration isolation effect against idle vibration are exhibited, and characteristics in the normal use region can be ensured. Further, when the amount of flexure deformation of the second diaphragm 56 becomes larger than a specified value at the time of inputting a large amplitude, the liquid tight state of the valve portion 80 with respect to the first opposing wall 68 and the second opposing wall 70 is released. In the diaphragm 56, liquid leakage occurs between the main liquid chamber 42 and the first sub liquid chamber 44. In addition, liquid leakage between the main liquid chamber 42 and the first sub liquid chamber 44 can be generated with respect to the movement of the second diaphragm 56 in both the upper and lower directions, and the valve function in both directions can be exhibited. About 3rd Embodiment, the other structure and effect are the same as 1st Embodiment, and description is abbreviate | omitted.

[Other Embodiments]
In the first embodiment, the second orifice channel 66 provided in the lid member 62 has a thickness of the second facing wall 70 in which the central through hole 74 is provided by the cylindrical portion 72 protruding to the main liquid chamber 42 side. However, the length of the second orifice channel 66 may be set to be equal to the thickness of the second opposing wall 70. Even if the orifice length is the same, by setting the opening area to be smaller than that of the central through hole 74, it is possible to exert a throttling effect as the second orifice channel 66. Similarly, in the third embodiment, the second orifice channel 66 provided in the second opposing wall 70 is also provided with the length of the orifice in the central through hole of the first opposing wall 68 without providing the cylindrical portion 86. The thickness may be set equal to 88.

  In the above embodiment, the number of first through holes 76 and the number of second through holes 78 provided in the second diaphragm 56 is set to be the same, but the number of first through holes 76 and the number of second through holes 78 are different. Also good. Moreover, the shape of the 1st and 2nd through-holes 76 and 78 is not limited to the circular shape of the said embodiment, Various shapes can be employ | adopted.

  In the above embodiment, the valve portion 80 is provided so as to surround each of the through holes 76, 78. However, the single valve portion 80 surrounds the plurality of first through holes 76. Alternatively, the plurality of second through holes 78 may be surrounded by one valve portion 80. Further, the valve portion 80 is not necessarily limited to a form surrounding the through holes 76 and 78 as long as the first through hole 76 and the second through hole 78 can be separated in a liquid-tight manner. Various forms for partitioning between the second through holes 78 can be adopted. Moreover, in the said embodiment, although the shape and arrangement | positioning of the upper and lower valve part 80 which protrude from the film surface of the front and back of the 2nd diaphragm 56 were made the same, the shape and arrangement | positioning of the valve part 80 may differ vertically.

  In the above embodiment, the case where two sub liquid chambers of the first sub liquid chamber 44 and the second sub liquid chamber 64 are provided as the liquid chamber together with the main liquid chamber 42 has been described. A liquid chamber may be provided.

  In the above embodiment, the shake vibration and the idle vibration are targeted. However, the present invention is not limited to this, and can be applied to various vibrations having different frequencies. In the above embodiment, the first fixture 12 is attached to the support side (vehicle body side) and the second fixture 14 is attached to the vibration source side (engine side). You may comprise so that an attachment may be attached to the vibration source side and a 2nd attachment may be attached to a support side. Although not enumerated one by one, various modifications can be made without departing from the spirit of the present invention.

  The present invention can be used for various vibration isolators such as a mount that supports other power units such as a motor, a body mount, and a differential mount, in addition to an engine mount.

DESCRIPTION OF SYMBOLS 10,10A ... Liquid enclosure type vibration isolator 12 ... 1st fixture 14 ... 2nd fixture 16 ... Anti-vibration base | substrate 36 ... Liquid enclosure chamber 38 ... 1st diaphragm 40 ... Partition body 42 ... Main liquid chamber 44 ... 1st Secondary liquid chamber 50 ... first orifice flow channel 56 ... second diaphragm 64 ... second secondary liquid chamber 66 ... second orifice flow channel 68 ... first opposing wall 70 ... second opposing wall 76 ... first through hole 78 ... first 2 through-hole 80 ... valve portion 82 ... first communication hole 84 ... second communication hole

Claims (6)

A first fixture, a second fixture, a vibration isolating base made of a rubber-like elastic body interposed between the first fixture and the second fixture, and attached to the first fixture. A first diaphragm made of a rubber-like elastic body, a liquid sealing chamber formed between the vibration isolating substrate and the first diaphragm inside the first fixture, and the liquid sealing chamber as the vibration isolating substrate. A liquid comprising: a partition that partitions the main liquid chamber on the side and the first sub liquid chamber on the first diaphragm side; and a first orifice channel that connects the main liquid chamber and the first sub liquid chamber. In the enclosed vibration isolator,
The partition is
A second auxiliary liquid chamber;
A second orifice channel that is tuned to a higher frequency range than the first orifice channel and connects either the main liquid chamber or the first sub-liquid chamber to the second sub-liquid chamber;
A first elastic liquid body is formed of a rubber-like elastic body which forms a partition wall between the other of the main liquid chamber and the first sub liquid chamber and the second sub liquid chamber and whose outer peripheral portion is liquid-tightly held with respect to the partition body. 2 diaphragms,
A first opposing wall facing one film surface of the second diaphragm and forming a part of a wall of the main liquid chamber;
A second opposing wall that opposes the other membrane surface of the second diaphragm and forms part of the chamber wall of the first sub-liquid chamber;
With
The second diaphragm is provided with at least one first through hole and at least one second through hole, and the first through hole and the second through hole protrude from both front and back surfaces of the second diaphragm. The first opposing wall and the second opposing wall are separated from each other by a valve portion that is in liquid-tight contact with the first opposing wall, and the first through hole is formed by the first communication hole provided in the first opposing wall. The second through hole is provided in communication with the first sub-liquid chamber through a second communication hole provided in the second opposing wall. Liquid-filled vibration isolator.   The liquid-filled vibration isolator according to claim 1, wherein the first through hole and the second through hole are liquid-tightly isolated from the second sub liquid chamber by the valve portion.   3. The liquid-sealed type according to claim 1, wherein the valve portion is configured to open a liquid-tight state with respect to the first opposing wall and the second opposing wall by bending deformation of the second diaphragm. Anti-vibration device.   The liquid-filled vibration isolator according to any one of claims 1 to 3, wherein the valve portion is provided in a cylindrical shape surrounding each of the first through hole and the second through hole. .   An opening of the second orifice channel to the second sub-liquid chamber is provided at a position facing a central portion of the second diaphragm, and the second diaphragm has the first through hole around the central portion. The liquid-filled vibration isolator according to any one of claims 1 to 4, wherein the second through hole is provided.   The second orifice channel connects the main liquid chamber and the second sub liquid chamber, and the second diaphragm forms a partition wall between the first sub liquid chamber and the second sub liquid chamber. The liquid-filled vibration isolator according to any one of claims 1 to 5.

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