JP2010071367A - Liquid-sealed vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To switch a characteristic by an inexpensive structure, in a liquid-sealed vibration control device having a plurality of orifice passages. <P>SOLUTION: A valve member 66 made of a rubber-like elastic film for opening-closing a second orifice flow passage 60, is arranged in a partition body 40 so as to be orthogonal to the flow direction in the middle of a first flow passage part 60A of the second orifice flow passage. The valve member has a film part 66B sandwiching an outer peripheral part by a wall surface of a valve storage chamber 68 and deflectively deformed by a liquid flow in the second orifice flow passage on the inside of the outer peripheral part, and blocks up openings 60C and 60D of the second orifice flow passage when the film part 66B is deflectively deformed. The center O<SB>V</SB>of the valve member 66 is arranged deviated from the center O<SB>L</SB>of a second sub-liquid chamber 52 so that the first flow passage part 60A does not overlap with the second sub-liquid chamber 52 in the thickness direction of the partition body 40. <P>COPYRIGHT: (C)2010,JPO&INPIT

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 vibration source side, a second attachment attached to the support 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; And an orifice channel that communicates between the liquid chambers, and is configured to perform a vibration damping function and a vibration insulation function by the liquid flow effect by the orifice channel and the vibration damping effect of the vibration-proof substrate. An enclosed vibration isolator is known.

  In this type of liquid-filled vibration isolator, a plurality of orifice passages tuned to different frequencies are provided so that the orifice passages can be switched in order to cope with a wide range of vibrations. Yes.

  For example, Patent Document 1 below discloses a switchable liquid-filled vibration isolator that can be closed with an urging means such as a spring with respect to the opening of the high-frequency side orifice channel. In this document, negative pressure is used to open the opening from the closed state. That is, a switching chamber in which atmospheric pressure and negative pressure can be selectively introduced is provided behind the diaphragm, and by introducing atmospheric pressure into the switching chamber, the high-frequency orifice channel is closed by the urging means, and the switching chamber is negatively charged. By introducing pressure, the high-frequency side orifice channel is opened.

  In the following Patent Document 2, a sliding portion called a plunger is provided in a partition body between a main liquid chamber and a sub liquid chamber, and the plunger is urged to an open state of a high frequency side orifice channel by a spring. A configuration is disclosed in which the plunger is moved up and down by the pressure difference between the liquid chambers to switch between opening and closing of the high-frequency side orifice channel.

  In the following Patent Document 3, a high frequency side orifice channel is formed inside the upper fixture, a second sub liquid chamber is provided thereon, a movable membrane is disposed in the second sub liquid chamber, and upper and lower sides of the movable membrane are arranged. A configuration is disclosed in which the opening and closing of the high-frequency orifice channel is attempted by movement.

Patent Document 4 listed below has a configuration in which a connecting flow path that connects the main liquid chamber and the sub liquid chamber is closed by using a biasing means such as a leaf spring on the main liquid chamber side of the partition body. It is disclosed. However, this document discloses that when the main liquid chamber reaches a predetermined pressure or less due to an input of a shocking large load vibration, the connection flow path is opened, so that the sub liquid chamber moves from the main liquid chamber to the main liquid chamber. It leaks liquid and suppresses cavitation, and does not switch the orifice flow path tuned to a different frequency.
Japanese Patent No. 3663482 JP 2004-003614 A JP 2008-051214 A JP 2007-107712 A

  In the configuration of Patent Document 1, it is necessary to provide a switching chamber, which increases the size of the vibration isolator. Further, it is necessary to separately provide a spring as an urging means and a diaphragm for forming a switching chamber, which increases costs.

  In the configuration of Patent Document 2, the plunger is slid by the pressure difference between the main liquid chamber and the sub liquid chamber, so that the high-frequency side orifice passage is relatively closed. That is, in this case, the plunger is slid by the pressure difference between the main liquid chamber and the sub liquid chamber, not by the liquid flow in the high-frequency side orifice flow path, and the pressure difference is utilized. In this case, since the operating frequency band becomes higher than when liquid flow is used, the effect is slow, and the damping effect of low-frequency shake vibration is inferior. Moreover, in the structure of this literature, in order to guarantee the sliding of the plunger, the dimensional accuracy of the member is required, and the cost increase is large.

  In the configuration of Patent Document 3, since the movable membrane does not have a return means, the position of the movable membrane is easily affected by gravity, lacks positional stability, and the reliability of the switching operation is insufficient.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide a liquid-filled vibration isolator having a plurality of orifice channels that can switch characteristics with an inexpensive structure. .

  The liquid-filled vibration isolator according to the present invention includes a first fixture that is attached to one of the vibration source side and the support side, a second fixture that is attached to the other of the vibration source side and the support side, and the first attachment. An anti-vibration base made of a rubber-like elastic body interposed between a fixture and a second fixture, a first diaphragm made of a rubber-like elastic film attached to the second fixture, and the anti-vibration base A main liquid chamber in which a liquid forming a part of a chamber wall is enclosed; a first sub liquid chamber in which a liquid in which the first diaphragm forms a part of a chamber wall; and the main liquid chamber and the first sub liquid chamber A partition that partitions the liquid chamber, a second diaphragm made of a rubber-like elastic film provided on the partition, and a second diaphragm that forms a part of a chamber wall and that is provided in a central portion of the partition. Two sub liquid chambers, a first orifice channel for communicating the main liquid chamber and the first sub liquid chamber, A second orifice provided in the partition, which is tuned to a frequency region higher than that of the first orifice channel to communicate the second sub-liquid chamber with the main liquid chamber or the first sub-liquid chamber. A flow path, and a valve member made of a rubber-like elastic film that opens and closes the second orifice flow path. The second orifice channel includes a first channel part extending in the thickness direction of the partition and a second channel part connected to the first channel part and extending around the second sub-liquid chamber. And comprising. A valve housing chamber for housing and holding the valve member is provided in the partition so as to be orthogonal to the flow direction of the flow channel in the middle of the first flow channel portion. The valve member is provided in the partition body by having an outer peripheral portion sandwiched between wall surfaces of the valve accommodating chamber and being bent and deformed inside the outer peripheral portion by a liquid flow in the second orifice channel. And a flexible membrane portion that closes the opening of the second orifice channel to the valve accommodating chamber. The membrane portion has a communication hole for communicating the second orifice channel at a position that does not overlap the opening of the partition, and the second orifice in a state where the membrane portion is separated from the opening. It is comprised so that a flow path may be opened. The center of the valve member is arranged so as to be offset from the center of the second sub-liquid chamber so that the first flow path portion does not overlap the second sub-liquid chamber in the thickness direction of the partition.

  With such a liquid filled type vibration isolator, when the input has a relatively small amplitude, the second orifice channel is not blocked by the valve member, and the liquid in the second orifice channel is communicated through the communication hole provided in the valve member. Therefore, it is possible to realize characteristics using the second orifice channel on the high frequency side. On the other hand, when the input has a relatively large amplitude, the liquid flow in the second orifice channel increases, so that the valve member bends and deforms, and the second orifice channel on the high frequency side is closed. Thereby, since the liquid moves between the liquid chambers only through the first orifice channel on the low frequency side, it is possible to ensure a high attenuation performance on the low frequency side.

  Further, since the second orifice channel is closed by bending deformation of the valve member made of a rubber-like elastic film, when the liquid flow to the valve member becomes small, the restoring force of the valve member causes the second orifice. The flow path can be returned to the open state. Therefore, an urging means such as a spring and a switching chamber for negative pressure are not required, and the apparatus can be easily reduced in size and cost.

  In addition, the first subchannel of the second orifice channel that opens and closes the valve member by decentering the centers of the valve member and the second subliquid chamber after providing the second subliquid chamber in the central portion of the partition body. Since the portion is provided so as not to overlap the second secondary liquid chamber in the thickness direction of the partition, the first flow path portion can be directly connected to the second flow path portion around the second secondary liquid chamber. Therefore, it is easy to secure the length of the second orifice channel while keeping the thickness of the partition body small.

  In the liquid-filled vibration isolator, the partition body has a circular shape in plan view, the valve member has a disk shape, and the center of the valve member is larger than the radius of the valve member from the center of the partition body. It may be arranged so as to be biased. In this way, by setting the valve member to be offset with respect to the center of the partition body, the setting so that the first flow path portion does not overlap the second sub-liquid chamber is facilitated.

  In the liquid-filled vibration isolator, the membrane portion is bent and deformed on the membrane surface of the membrane portion at a position that does not overlap the opening of the partition body, so that the valve housing chamber is opposed to the opposing wall surface. Protrusions that are compressed in between may be provided. By providing the projections on the membrane portion in this way, it is possible to further increase the restoring force after the deformation of the valve member. That is, the valve member after the deformation of the deformation is more reliably restored and the second orifice flow is improved. The road can be surely opened. Further, even when the valve member is bent and deformed, the displacement of the film portion around the protrusion can be suppressed, and the contact area between the valve member and the wall surface of the partition body when the second orifice channel is closed can be reduced. Effective in reducing abnormal noise.

  In the liquid-filled vibration isolator, the communication holes are juxtaposed at a plurality of locations on the circumference surrounding the plug portion at the center of the membrane portion, and the protrusions are formed at the communication holes at a plurality of locations on the circumference. And may be provided alternately. Thus, by providing a plurality of communication holes and protrusions alternately on the circumference, the restoring force of the valve member after bending deformation is enhanced, and the noise reduction effect is excellent.

  In the liquid-filled vibration isolator, the outer peripheral portion of the valve member is formed thicker than the membrane portion, and abuts on the inner peripheral surface of the thick outer peripheral portion so as to be inward of the outer peripheral portion. A ring-shaped restricting protrusion that restricts the displacement of the valve accommodating chamber may be provided on the wall surface of the valve accommodating chamber. Thereby, when a valve member bends and deforms, it is hard to shift | deviate radially inside, and can maintain performance.

  According to the present invention, in a liquid-filled vibration isolator having a plurality of orifice passages, characteristics can be effectively switched without providing a biasing means such as a spring or a switching chamber for negative pressure. Therefore, it is possible to provide a liquid-filled vibration isolator that switches such characteristics at low cost.

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

  FIG. 1 is a longitudinal sectional view of a liquid filled type vibration damping device 10 according to an embodiment. The vibration isolator 10 is an engine mount that supports an automobile engine, and includes an upper first fixture 12 that is attached to the engine that is a vibration source, and a cylindrical lower portion that is attached to a support-side vehicle body. 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.

  The 1st fixture 12 is the boss | hub metal fitting distribute | arranged above the axial center part of the 2nd fixture 14, 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 second fixture 14 includes a cylindrical tubular fitting 22 on which the vibration-proof base 16 is vulcanized and a cup-like bottom fitting 24, and a downward mounting bolt 26 projects from the center of the bottom fitting 24. It is configured to be attached to the vehicle body side via the bolt 26. 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 first fixture 12. 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 a truncated cone shape, and its upper end is vulcanized and bonded to the first fixture 12 and its lower end is vulcanized and bonded to the upper end opening of the cylindrical fitting 22. A rubber film-like seal wall portion 34 covering the inner peripheral surface of the cylindrical metal fitting 22 is connected to the lower end portion of the vibration isolation base 16.

  The second fixture 14 includes a first diaphragm 38 made of a flexible rubber film that is disposed opposite to 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. The liquid is enclosed in the liquid enclosure chamber 36. 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 is divided into an upper main liquid chamber 42 in which the vibration isolation base 16 forms a part of the chamber wall and a lower first auxiliary sub chamber in which the first diaphragm 38 forms a part of the chamber wall. The liquid chamber 44 is partitioned.

  The partition body 40 includes a partition body main body 46 made of a rigid material such as metal, which has a circular shape in plan view and is fitted to the inside of the cylindrical fitting 22 via the seal wall portion 34, and a lower surface of the partition body main body 46. And a partition receiving plate 48 disposed in contact with the side. The partition receiving plate 48 is a disk-shaped metal fitting having a circular opening at the center, and a second diaphragm 50 made of a flexible rubber film is integrally provided at the center opening by vulcanization molding. Then, by fixing the partition receiving plate 48 together with the reinforcing metal fitting 39 of the first diaphragm 38 by the caulking portion 28, the partition body main body 46 has a stepped portion 34A provided on the seal wall portion 34 and a partition receiving plate. 48 is held in a state sandwiched in the axial direction X.

A second sub liquid chamber 52 that is partitioned from the first sub liquid chamber 44 by a second diaphragm 50 is provided on the first sub liquid chamber 44 side of the partition body 40. Specifically, as shown in FIG. 5C, a circular recess 54 is provided at the center of the lower surface of the partition body 46, and the recess 54 is liquid-tightened by the second diaphragm 50 from below. As a result, the second sub-liquid chamber 52 having a circular shape in plan view in which the second diaphragm 50 forms a part of the chamber wall is formed. In this way, the second sub liquid chamber 52 is provided in the central portion of the partition body 40 on the first sub liquid chamber 44 side. Strictly speaking, in this example, the second sub liquid chamber 52 is shown in FIG. 2 and FIG. as shown, the center O _L of the second auxiliary liquid chamber 52 are arranged with slightly biased from the center (axis) O _P of the partition member 40 in the radially outward side.

  The main liquid chamber 42 and the first sub liquid chamber 44 are communicated with each other via a first orifice channel 56 which is a throttle channel. In this example, the first orifice channel 56 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 56 is effectively exhibited when the shake vibration is input. .

  The first orifice channel 56 is provided on the outer peripheral side of the partition body 40. More specifically, a circumferential direction C (see FIG. 5) is formed between the first orifice forming groove 58 (see FIG. 5) provided on the outer periphery of the partition body 46 and opened outward, and the seal wall 34. A first orifice channel 56 extending in (b) is formed. As shown in FIG. 5A, the first orifice passage 56 includes a main liquid chamber side opening 56 </ b> A that opens to the main liquid chamber 42 at one end in the circumferential direction C and the other end in the circumferential direction C. The sub liquid chamber side opening 56 </ b> B that opens to the first sub liquid chamber 44 is provided.

  The main liquid chamber 42 and the second sub liquid chamber 52 are communicated with each other via a second orifice channel 60 which is a throttle channel. The second orifice channel 60 is a high-frequency side orifice tuned in a higher frequency range than the first orifice channel 56. In this example, in order to reduce idle 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, it is tuned 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 60 is effectively exhibited when the idle vibration is input. ing.

  The second orifice channel 60 is provided on the inner peripheral side of the partition body 40, and includes a first channel portion 60 </ b> A extending in the thickness direction of the partition body 40 (in this example, the same as the axial direction X), and the partition The first sub liquid chamber 44 side of the body 40 is connected to the first flow path portion 60 </ b> A and includes a second flow path portion 60 </ b> B extending along the second sub liquid chamber 52.

  Specifically, as shown in FIG. 2, the second orifice flow path 60 includes a first flow path portion 60 </ b> A that penetrates the partition body 46 in the axial direction X on the inner peripheral side of the first orifice formation groove 58, and It consists of an arc-shaped second flow path portion 60B extending in the circumferential direction C provided on the outer surface in the radial direction of the second auxiliary liquid chamber 52 on the lower surface of the partition body 46 (see FIG. 5). And it opens to the main liquid chamber 42 at the upper end of the first flow path part 60A, one end of the second flow path part 60B is connected to the lower end of the first flow path part 60A, and the other end of the second flow path part 60B is By being connected to the second sub liquid chamber 52, the main liquid chamber 42 and the second sub liquid chamber 52 communicate with each other. The second flow path portion 60B has a second orifice forming groove 62 recessed in the lower surface of the partition body 46, and a seal rubber portion integrally connected to the upper surface of the partition receiving plate 48 from the outer peripheral portion of the second diaphragm 50. It is formed by being liquid-tightly sealed with 64.

  The vibration isolator 10 includes a disc-shaped valve member 66 made of a rubber elastic body that opens and closes the second orifice channel 60. The partition body 40 is provided with a valve accommodating chamber 68 in a part of the second orifice channel 60, and the valve member 66 is orthogonal to the flow direction of the second orifice channel 60 in the valve accommodating chamber 68. Is housed and held. As shown in FIGS. 1 to 3, the valve member 66 is in a posture in which the film surface is orthogonal to the axial direction X that is the flow direction in the middle of the first flow path portion 60 </ b> A of the second orifice flow path 60. It is arranged.

  Specifically, as shown in FIGS. 5A and 5B, a stepped recess 70 having a circular shape in plan view is provided on the upper surface of the partition body 46, and a metal is formed on the opening side of the stepped recess 70. A space formed by the stepped recess 70 and the lid member 72 is defined as the valve accommodating chamber 68 by internally fitting and fixing the disc-like lid member 72 made of a rigid material such as the above. As shown in FIG. 5B, a circular opening 60C of the second orifice channel 60 is provided at the center of the stepped recess 70, and the lid member is opposed to the opening 60C in the axial direction X. As shown in FIG. 6, a circular opening 60 </ b> D is provided at the center of 72, and these openings 60 </ b> C and 60 </ b> D are openings of the second orifice channel 60 to the valve storage chamber 68.

  The valve member 66 is mounted in the stepped recess 70 and the lid member 72 is fixed, so that the outer peripheral portion 66A has upper and lower wall surfaces 68A and 68B (that is, the stepped surface and the lower surface of the lid member 72 are stepped). It is held in the valve storage chamber 68 in a state of being liquid-tightly held by the bottom surface of the recess 70. As shown in FIG. 4, the valve member 66 includes a flexible membrane portion 66 </ b> B in which the outer peripheral portion 66 </ b> A is thick over the entire circumference and a thin film is formed inside the thick outer peripheral portion 66 </ b> A. It becomes. The film portion 66B is formed so as to block between the inner peripheral surfaces at an intermediate position in the thickness direction (axial direction X) of the thick outer peripheral portion 66A.

  The membrane portion 66B is bent and deformed (elastically deformed) in the axial direction X from the neutral position shown in FIG. 7A due to the liquid flow in the second orifice channel 60, and as shown in FIG. 7B. As described above, the openings 60C and 60D of the second orifice channel 60 are configured to be closed. Therefore, in the membrane portion 66B, the central portion facing the openings 60C and 60D is a plug portion 66C that closes the openings.

  As shown in FIG. 4, the membrane portion 66 </ b> B has a plurality of communication holes 76 that allow the second orifice channel 60 to communicate with each other so as not to overlap the openings 60 </ b> C and 60 </ b> D, that is, when viewed from the axial direction X. Prepare. The communication holes 76 are juxtaposed at a plurality of locations on the circumference surrounding the plug portion 66C located at the center of the membrane portion 66B. In this example, four circular communication holes 76 are provided at equal intervals. It has been. The communication hole 76 passes through the communication hole 76 in the state where the membrane portion 66B is separated from the openings 60C and 60D, that is, the plug portion 66C opens these openings (see FIG. 3). The liquid flows therein, and the second orifice channel 60 is thereby opened. The opening area of the communication hole 76 is set to be larger than the cross-sectional area of the second orifice channel 60, that is, the area of the openings 60 </ b> C and 60 </ b> D so that the throttling effect is not exhibited in the communication hole 76. .

  The membrane portion 66B is compressed between the opposing wall surfaces 68A and 68B of the valve accommodating chamber 68 by the membrane portion 66B being bent and deformed on the membrane surface at a position not overlapping the openings 60C and 60D. A plurality of projections 78 are provided. As shown in FIG. 4, the protrusion 78 has a conical shape, in this example, a conical shape, and is provided alternately with the communication hole 76 on the same circumference as the communication hole 76. Further, the protrusions 78 project from the upper and lower film surfaces of the film part 66B and are formed vertically symmetrical. In this example, the protrusion 78 is formed so that the tip, that is, the top of the cone, substantially contacts the wall surfaces 68A and 68B of the valve accommodating chamber 68 at the neutral position of the valve member 66. It can also be set so that it does not abut at the position.

  As shown in FIG. 3, the upper and lower wall surfaces 68 </ b> A and 68 </ b> B of the valve storage chamber 68 are in contact with the inner peripheral surface 66 </ b> A <b> 1 (see FIG. 4C) of the thick outer peripheral portion 66 </ b> A of the valve member 66. A ring-shaped restricting protrusion 80 for restricting the inward displacement of the portion 66A is provided. That is, as shown in FIG. 5A and FIG. 6, the restricting protrusion 80 is formed so as to protrude vertically from the bottom surface of the stepped recess 70 and the lower surface of the lid member 72.

  As shown in FIG. 3, the peripheral edge portions of the openings 60 </ b> C and 60 </ b> D are provided as annular convex portions 82 projecting in the axial direction X (see FIGS. 5 and 6). It is formed so as to protrude toward the film portion 66B side with respect to 68A and 68B. The annular protrusion 82 has a circular shape in a plan view that surrounds the circular openings 60C and 60D over the entire circumference. The front end surface of the annular convex portion 82 is flat, and a predetermined clearance is secured in the axial direction X between the flat front end surface and the plug portion 66C at the center of the valve member 66 facing the front end surface. .

As shown in FIG. 2, the valve member 66 has its center O _V is, relative to the center O _P of the partition member 40, with the center O _L of the second auxiliary liquid chamber 52 on the opposite side, arranged by offsetting ing. That is, the valve member 66, which is such that the first flow path portion 60A for opening and closing does not overlap with the second auxiliary liquid chamber 52 in the thickness direction X of the partition member 40, the center O _V of the valve member 66 and a second auxiliary fluid chamber It is arranged to bias the 52 center O _L of. As shown in FIGS. 2 and 5B, the valve member 66 itself (see the valve accommodating chamber 68 in FIG. 5B) is partly connected to the second auxiliary liquid chamber 52 as viewed from the thickness direction X. although overlap, the first flow path portion 60A so as not to overlap the second sub-liquid chamber 52 (referring to FIG. 5 (b) in the recess 54), the valve member 66 partitioning body located at the center O _V 40 is shifted from the central portion to the peripheral portion side. In this example, the center O _V of the valve member 66, from the center O _P of the partition member 40, and is offset above the radius value of the valve member 66.

  In the liquid-filled vibration isolator 10 having the above-described configuration, the flow of liquid in the second orifice channel 60 is small when vibration on the high frequency side with a relatively small amplitude is input, such as during idling when the vehicle is stopped. The membrane portion 66B of the valve member 66 is hardly bent and deformed. Therefore, as shown in FIG. 7A, the second orifice channel 60 is not blocked by the valve member 66, and the liquid in the second orifice channel 60 flows through the communication hole 76 provided in the valve member 66. It is possible to move between the main liquid chamber 42 and the second sub liquid chamber 52. Therefore, an excellent vibration-proofing effect against idle vibration is exhibited by the resonance action of the liquid through the second orifice channel 60 on the high frequency side.

  On the other hand, when a vibration having a relatively large amplitude and a low frequency, such as a shake vibration, is input during traveling of the vehicle, the flow of the liquid in the second orifice channel 60 becomes large, and the liquid flow causes the membrane of the valve member 66 to flow. When the portion 66B is pressed in the flow direction X, it is bent and deformed. Thereby, as shown in FIG.7 (b), the 2nd orifice flow path 60 is obstruct | occluded by the film | membrane part 66B. For this reason, the liquid moves between the main liquid chamber 42 and the first sub liquid chamber 44 only through the first orifice channel 56 on the low frequency side, so that the resonance action of the liquid flowing through the first orifice channel 56 is achieved. Based on this, high damping performance is exhibited against shake vibration.

  As described above, the liquid-filled vibration isolator 10 has a structure in which the second orifice channel 60 is closed by the bending deformation of the valve member 66 made of a rubber elastic film, and thus the liquid flow to the valve member 66 is small. When this happens, the second orifice channel 60 can be returned to the open state by the restoring force of the valve member 66. Therefore, it is possible to switch the characteristics of the two orifice channels 56 and 60 without separately providing a biasing means such as a spring, and to provide a switchable liquid-filled vibration isolator with an inexpensive and compact structure. Can do.

  In addition, since the valve member 66 is provided offset to the partition body 40 as described above, the second orifice channel 60 is formed in the second sub-channel 60 after the second sub-liquid chamber 52 is provided in the central portion of the partition body 40. It becomes easier to set the liquid chamber 52 outside in the radial direction. That is, the first flow path portion 60A extending in the thickness direction X of the second orifice flow path 60 opened and closed by the valve member 66 is not overlapped with the second sub liquid chamber 52 in the thickness direction X of the partition body 40. Since the valve member 66 is disposed, the lower end of the first flow path portion 60A can be directly connected to the second flow path portion 60B around the second sub liquid chamber 52. Therefore, it is possible to ensure the length of the second orifice channel 60 while keeping the thickness of the partition body 40 small. Here, if the first flow path portion is disposed so as to overlap the second sub liquid chamber, the second flow around the second sub liquid chamber is secured in order to ensure a large length of the second orifice flow path. When it is intended to provide the passage portion, it is necessary to pull out the first flow passage portion radially outward so as not to overlap with the second sub liquid chamber in order to connect to the second flow passage portion, and the radial passage extends in this radial direction. The thickness of the partition body is required by the amount corresponding to the flow path, and the structure thereof is complicated, but such a drawback can be solved by offsetting as described above.

  Further, according to the present embodiment, the projection 78 is provided on the membrane portion 66B of the valve member 66 as described above, and this projection 78 is shown in FIG. 7B when the membrane portion 66B is bent and deformed. As shown, it is compressed between the wall surfaces 68 </ b> A and 68 </ b> B of the valve storage chamber 68. The repulsive force of the compressed protrusion 78 makes it possible to increase the restoring force of the valve member 66 after the bending deformation, so that the return of the valve member 66 after the bending deformation can be made more reliable, and the second orifice. The channel 60 can be reliably and smoothly opened.

  Further, even when the valve member 66 is bent and deformed, as shown in FIG. 7B, the displacement of the film portion 66 </ b> B around the protrusion 78 is suppressed, and the valve member 66 when the second orifice channel 60 is closed. And the contact area between the wall surfaces 68A and 68B of the valve storage chamber 68 can be reduced. Therefore, an effect can be exhibited in reducing abnormal noise caused by the collision between the valve member 66 and the wall surfaces 68A and 68B.

  Further, in the above embodiment, the valve member 66 is provided with a plurality of communication holes 76 and projections 78 alternately on the same circumference, so that the restoring force of the valve member 66 after bending deformation can be increased, and the wall surface 68A. , 68B is also excellent in noise reduction effect due to the reduction of the contact area.

  Further, in the above embodiment, the restriction protrusions 80 are provided on the upper and lower wall surfaces 68A and 68B of the valve storage chamber 68. Therefore, when the valve member 66 is bent and deformed, the restriction is applied to the inner peripheral surface of the outer peripheral portion 66A of the valve member 66. Since the protrusion 80 contacts and restricts the inward displacement thereof, the valve member 66 is less likely to be displaced radially inward (not easily moved), and the performance of the valve member 66 can be maintained.

  Further, in the above embodiment, the wall surfaces 68A and 68B at the periphery of the openings 60C and 60D facing the plug portion 66C of the valve member 66 are formed as the annular convex portions 82 that are more convex than the periphery thereof. By setting the height of the annular protrusion 82, the clearance between the closing openings 60C and 60D can be easily adjusted. Therefore, it is easy to adjust a region (input amplitude or the like) where the second orifice channel 60 is closed.

  Further, by providing the annular convex portion 82, the stroke until the plug portion 66C closes the openings 60C and 60D is reduced, and the impact at the time of contact can be reduced. Further, due to the presence of the annular protrusion 82, the contact between the valve member 66 and the wall surfaces 68A and 68B can be limited to the annular protrusion 82, and the noise level can be reduced by reducing the contact area. .

  FIG. 8 is a graph showing the anti-vibration characteristics of the liquid-filled vibration isolator 10 according to the above-described embodiment. As a comparative example, the valve member 66 is omitted and the other liquid-filled vibration-proof vibration having the same orifice configuration as in the embodiment. The characteristics of the device are also shown.

  As shown in FIG. 8A, at a relatively small amplitude (± 0.05 mm), the characteristics of the embodiment (storage spring constant Kd and damping coefficient C) and the characteristics of the comparative example (storage spring constant Kd ′ and The damping coefficient C ′) was the same. However, as shown in FIG. 8B, at a relatively large amplitude (± 0.5 mm), the characteristic (Kd ′, C ′) of the comparative example represented by the thin line is different from the characteristic of the embodiment represented by the thick line (Kd ′, C ′). As for Kd, C), a higher attenuation performance C was secured on the low frequency side.

  FIG. 9 shows (a) pressure fluctuation in the main liquid chamber 42 and (b) high-frequency orifice (second orifice) at a relatively large amplitude (± 0.5 mm) for the liquid-filled vibration isolator 10 of the above embodiment. It is a graph which shows the relationship with the frequency of the liquid flow in the flow path 60).

  The pressure fluctuation in the main liquid chamber 42 can be equated with the pressure difference between the main liquid chamber 42 and the second sub liquid chamber 52. As shown in FIG. 9A, in the embodiment, it exceeds 15 Hz. The fluid pressure fluctuation was the maximum near, and the pressure fluctuation was smaller on the lower frequency side. On the other hand, as for the liquid flow in the second orifice channel 60, a large liquid flow occurred at 7 Hz as shown in FIG. 9B. Therefore, the switching characteristics of the orifice at a lower frequency is achieved in the present embodiment that is operated by the liquid flow in the second orifice channel than in the case of operating by the pressure difference between the liquid chambers as in Patent Document 2. Can be expected. That is, since the liquid flow becomes more active from the lower frequency range than the pressure difference when the second orifice flow path 60 is operated by the liquid flow like the valve member 66 of the present embodiment, the second orifice at a lower frequency. The flow path 60 can be closed, which is advantageous for attenuation of shake vibration in a low frequency range.

  In the above embodiment, the projection 78 is provided on the membrane portion 66B of the valve member 66, but the projection 78 is not essential in the present invention. Further, the arrangement, number, and shape of the communication holes 76 and the protrusions 78 provided in the valve member 66 are not limited to the above-described embodiment, and various changes can be made. For example, the protrusions 78 are provided on the upper and lower surfaces of the film portion 66B in the above embodiment, but may be provided on only one of the surfaces.

  Moreover, in the said embodiment, although the cyclic | annular convex part 82 was provided in the up-and-down both sides of the valve member 66, this is also indispensable in this invention, and when providing, you may provide only in any one up and down.

  Further, in the above embodiment, the second sub liquid chamber 52 is provided on the first sub liquid chamber 44 side of the partition body 40, and the second orifice channel 60 is communicated with the main liquid chamber 42 and the second sub liquid chamber 52. However, instead of this, the second sub-liquid chamber is provided on the main liquid chamber side of the partition, and the second diaphragm is partitioned from the main liquid chamber by the second diaphragm. The second sub liquid chamber and the first sub liquid chamber may be configured to communicate with each other. In this case, the second orifice channel has a first channel portion that extends in the thickness direction of the partition body and opens to the first sub-liquid chamber side, and a second channel portion that extends around the second sub-liquid chamber. It is provided on the main liquid chamber side of the partition and is connected to the second sub liquid chamber.

  In the above-described embodiment, shake vibration and idle vibration are targeted. However, the present invention is not limited to this, and can be applied to various vibrations having different frequencies. In addition to the engine mount, the present invention can be applied to various vibration isolators such as a body mount and a differential mount. Although not enumerated one by one, various modifications can be made without departing from the spirit of the present invention.

1 is a longitudinal sectional view of a liquid-filled vibration isolator according to an embodiment of the present invention. Sectional drawing of the partition body of the embodiment The principal part expanded sectional view of the partition The valve member of the same embodiment is represented, (a) is a perspective view, (b) is a top view, (c) is the alpha-alpha sectional view taken on the line. It represents the partition body main body of the embodiment, (a) is a perspective view, (b) is a plan view, (c) is a bottom view. Bottom view of the lid member of the same embodiment It is a perspective sectional view of the periphery including the valve member of the same embodiment (the cover member is omitted), (a) is a view at the neutral position of the valve member (open state of the second orifice channel), ( b) is a valve It is a graph showing the vibration proof characteristic of the liquid filled type vibration proof device of embodiment, (a) is a graph at the time of a comparatively small amplitude, (b) is a graph at the time of a comparatively large amplitude. (A) The graph which shows the pressure fluctuation of the main liquid chamber of the vibration isolator of embodiment, (b) is the figure at the time of bending deformation of the graph member which shows the liquid flow in the 2nd orifice flow path of the vibration isolator ( The second orifice channel is closed)

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid enclosure type vibration isolator 12 ... 1st fixture 14 ... 2nd fixture 16 ... Anti-vibration base | substrate 38 ... 1st diaphragm 40 ... Partition body 42 ... Main liquid chamber 44 ... 1st subliquid chamber 50 ... 2nd Diaphragm 52 ... Second sub-liquid chamber 56 ... First orifice channel,
60 ... second orifice channel, 60A ... first channel unit, 60B ... second channel unit, 60C, 60D ... opening 66 ... valve member, 66A ... outer peripheral part, 66B ... membrane portion, 66C ... plug portion 68 ... valve chamber, 68A, the center _{O L} ... center of _{O V} ... valve member of the second auxiliary liquid chamber of 68B ... wall 76 ... communication hole 78 ... projection _{O C} ... partition body

Claims (5)

A first fixture attached to one of the vibration source side and the support side;
A second fixture attached to the other of the vibration source side and the support side;
An anti-vibration base made of a rubber-like elastic body interposed between the first fixture and the second fixture;
A first diaphragm comprising a rubber-like elastic membrane attached to the second fixture;
A main liquid chamber in which a liquid in which the vibration isolating substrate forms a part of a chamber wall is enclosed;
A first sub-liquid chamber in which a liquid in which the first diaphragm forms a part of a chamber wall;
A partition that partitions the main liquid chamber and the first sub liquid chamber;
A second diaphragm made of a rubber-like elastic film provided on the partition;
A second sub-liquid chamber in which the second diaphragm forms a part of a chamber wall and is provided in a central portion of the partition;
A first orifice channel for communicating the main liquid chamber and the first sub liquid chamber;
The second sub-liquid chamber is tuned to a frequency region higher than that of the first orifice channel to communicate the second liquid chamber with the main liquid chamber or the first sub-liquid chamber, and is provided in the partition body. An orifice channel;
A valve member made of a rubber-like elastic membrane for opening and closing the second orifice channel;
With
The second orifice channel has a first channel part extending in the thickness direction of the partition, and a second channel part connected to the first channel part and extending around the second sub liquid chamber. And
A valve accommodating chamber that accommodates and holds the valve member so as to be orthogonal to the flow direction of the flow path portion is provided in the partition in the middle of the first flow path portion,
The valve member is provided in the partition body by having an outer peripheral portion sandwiched between wall surfaces of the valve accommodating chamber and being bent and deformed inside the outer peripheral portion by a liquid flow in the second orifice channel. A flexible membrane portion for closing the opening of the second orifice channel to the valve storage chamber,
The membrane portion has a communication hole for communicating the second orifice channel at a position that does not overlap the opening of the partition, and the second orifice in a state where the membrane portion is separated from the opening. Configured to open the flow path,
The center of the valve member is arranged so as to be offset from the center of the second sub liquid chamber so that the first flow path portion does not overlap the second sub liquid chamber in the thickness direction of the partition.
A liquid-filled vibration isolator characterized by that.   2. The partition body having a circular shape in a plan view, the valve member having a disk shape, and the center of the valve member being arranged to be deviated from the center of the partition body by a radius equal to or greater than the radius of the valve member. The liquid-filled vibration isolator as described.   The membrane portion is provided with a protrusion that is compressed between the membrane portion facing the wall of the valve accommodating chamber when the membrane portion is bent and deformed on a membrane surface that does not overlap the opening of the partition. The liquid-filled vibration isolator according to claim 1 or 2.   The communication holes are arranged in parallel at a plurality of locations on the circumference surrounding the plug portion located at the center of the membrane portion, and the protrusions are provided alternately with the communication holes at a plurality of locations on the circumference. Item 4. A liquid-sealed vibration isolator according to item 3.   The outer peripheral portion of the valve member is formed thicker than the membrane portion, and a ring-shaped restricting protrusion that abuts against the inner peripheral surface of the thick outer peripheral portion and restricts the inward displacement of the outer peripheral portion. The liquid-filled vibration isolator according to claim 1, which is provided on a wall surface of the valve storage chamber.

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