JP2009281508A - Active liquid-filled vibration damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To always exert original performance due to an actuator by suppressing the displacement of the excitation plate due to temperature change in a storage space of the enclosed actuator. <P>SOLUTION: The excitation plate 18 is arranged between a vibration isolating base body 14 and a diaphragm 22. A first liquid chamber 16 is provided between the vibration isolating base body 14 and the excitation plate 18, and a second liquid chamber 24 is provided between the excitation plate 18 and the diaphragm 22 respectively. The storage space 46 of the actuator 20 is provided in a state where the storage space 46 of the actuator 20 at the opposite side of the second liquid chamber 24 holding the diaphragm 22 in a closed state from the outside. A movable shaft 50 is connected to the diaphragm 22 in a state where the diaphragm 22 is penetrated. A connector 72 of the movable shaft 50 with the diaphragm 22 is separated in an axial direction X of the movable shaft 50 for a connector 66 to the excitation plate 18 of the movable plate 50. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an active liquid-filled vibration isolator of the type that enhances the vibration isolating effect by controlling the pressure of an internal liquid chamber.

  2. Description of the Related Art Conventionally, in an anti-vibration device used, for example, as an engine mount of an automobile, an active liquid configured such that a part of a chamber wall of a liquid chamber is formed by a vibration plate, and the vibration plate is driven by an actuator. An enclosed vibration isolator is known. In an active liquid-filled vibration isolator, the pressure of the liquid chamber is controlled via an actuator to counteract vibrations or to positively change the spring characteristics in response to input vibrations. An excellent vibration suppression effect has been achieved, for example, by using a low dynamic spring.

  FIG. 4 is a cross-sectional view showing an example of a conventional active liquid-filled vibration isolator. In this vibration isolator, an upper first fixture 101, a lower second fixture 102, a vibration isolating base 103 made of a rubber-like elastic body connecting them, and the anti-vibration base 103 are provided on the chamber wall. A first liquid chamber 104 forming a part, a second liquid chamber 106 formed by a diaphragm 105 having a part of a chamber wall made of a rubber film, an orifice passage 107 communicating the two liquid chambers 104, 106, A vibration plate 108 that forms another part of the chamber wall of the liquid chamber 104 and an actuator 109 that controls the pressure of the first liquid chamber 104 by exciting the vibration plate 108 are configured. .

  The actuator 109 includes a movable shaft 110 connected to the vibration plate 108 and a stator 111 fixed to the second fixture 102 side. By exciting the coil 112 of the stator 111, the movable shaft 110 is provided. 110 is configured to reciprocate in the axial direction (vertical direction), thereby exciting the vibration plate 108.

  The diaphragm 105 is provided across the first fixture 101 and the second fixture 102 so as to cover the anti-vibration base 103 on the upper outer peripheral side of the anti-vibration base 103, and the outer circumference of the diaphragm 105 and the anti-vibration base 103 A second liquid chamber 106 is provided therebetween.

  The actuator 109 is accommodated in an accommodation space 113 provided on the bottom of the second fixture 102 on the opposite side of the first liquid chamber 104 with the vibration plate 108 interposed therebetween. Accordingly, the accommodation space 113 is provided facing the vibration plate 108 so that the vibration plate 108 forms a part of the chamber wall.

By the way, in an anti-vibration device mounted on an automobile, water may enter from the outside during rainy weather or a car wash, or foreign substances such as sand, gravel, and dust may enter during a rough road. In order to protect the actuator from such water and foreign matter, the following Patent Document 1 discloses that the actuator is housed and held in a sealed state from the outside in the housing space provided at the bottom of the second fixture. A configuration of
JP 2007-85407 A

  However, when the actuator is provided in a state of being sealed from the outside as described above, the atmospheric pressure in the space changes due to the temperature change of the accommodation space of the actuator. In this case, if the vibration plate faces the accommodation space of the actuator as in Patent Document 1, the vibration plate is displaced in the axial direction due to a change in atmospheric pressure. The displacement of the vibration plate means that the movable shaft of the actuator connected thereto is also displaced. Accordingly, the movable shaft of the actuator is displaced from the origin in the axial direction due to the change in atmospheric pressure, that is, the relative positional relationship between the movable shaft and the stator is displaced, and it is difficult to generate the original driving force. Become.

  Therefore, as shown in the comparative example of FIG. 5, it is conceivable that a diaphragm 105 is interposed between the vibration plate 108 and the actuator 109, and the diaphragm 105 forms a part of the chamber wall of the accommodation space 113 of the actuator 109. . According to this configuration, when the atmospheric pressure in the accommodation space 113 changes, the displacement of the vibration plate 108 can be expected to be suppressed by absorbing the atmospheric pressure change due to the deformation of the diaphragm 105.

  However, when the vibration plate 108 is arranged inside the diaphragm 105 in this way, a configuration in which the movable shaft 110 of the actuator 109 is connected to the vibration plate 108 after passing through the diaphragm 105 is required. At this time, as shown in FIG. 5, if the diaphragm 105 is directly coupled to the connecting portion 114 of the movable shaft 110 to the vibration plate 108, the following problem occurs. That is, as shown in FIG. 5, when the diaphragm 105 is integrally coupled to the vibration plate 108 at the central connecting portion 114, the vibration plate 108 is still displaced in the axial direction due to a change in the atmospheric pressure of the accommodation space 113. It's easy to do. For this reason, in such a structure, the displacement of the vibration plate 108 due to the temperature change of the accommodation space 113 cannot be sufficiently prevented, and it is difficult to always exhibit the original performance by the actuator 109.

  The present invention has been made in view of the above, and is an active type capable of suppressing the displacement of the vibration plate due to a temperature change in a sealed actuator housing space and making it easy to constantly exhibit the original performance of the actuator. An object of the present invention is to provide a liquid-filled vibration isolator.

  An active liquid-filled vibration isolator according to the present invention includes a first fixture, a second fixture, and a vibration isolating base made of a rubber-like elastic body that connects the first fixture and the second fixture. The vibration isolating base forms a part of the chamber wall, and another part of the chamber wall of the first liquid chamber is connected to the second fixture side via a rubber-like elastic support. The vibration plate, an actuator disposed on the opposite side of the first liquid chamber across the vibration plate to drive the vibration plate, and the actuator. A stator fixed to the second fixture side, a movable shaft that is supported so as to be reciprocally movable with respect to the stator and is connected to the vibration plate to drive the vibration plate, A diaphragm made of a rubber-like elastic film provided on the side opposite to the first liquid chamber across the vibration plate and connected to the second fixture side A second liquid chamber provided between the vibration plate and the diaphragm and having the vibration plate and the diaphragm as a part of a chamber wall; and the first liquid chamber and the second liquid chamber communicate with each other. And an orifice passage to be provided. And the accommodation space of the actuator is provided in a state sealed from the outside on the opposite side of the second liquid chamber across the diaphragm, and the movable shaft is coupled to the diaphragm in a state of passing through the diaphragm, The coupling portion of the movable shaft with the diaphragm is provided apart from the coupling portion of the movable shaft to the vibration plate in the axial direction of the movable shaft.

  According to the above configuration, since the housing space of the actuator is provided facing the diaphragm and does not face the vibration plate, the diaphragm is deformed even if the air pressure in the housing space changes due to a temperature change. Thus, the change in the atmospheric pressure can be absorbed, and the displacement of the vibration plate can be suppressed. In particular, with respect to the movable shaft that is connected to the vibration plate after passing through the diaphragm, the coupling portion with the diaphragm is provided apart from the connection portion of the movable shaft to the vibration plate in the axial direction. The vibration plate and the diaphragm are provided separately. Therefore, only the diaphragm can be easily deformed independently of the vibration plate with respect to the atmospheric pressure change in the accommodation space, and the displacement of the vibration plate can be suppressed by effectively absorbing the atmospheric pressure change by the diaphragm.

  In the active liquid filled type vibration damping device, an inner peripheral surface of the diaphragm fixed to an outer peripheral surface of the movable shaft is formed smaller than an outer shape of the vibration plate as viewed in the axial direction of the movable shaft. It is preferable. Thus, by setting the flexible membrane part of the diaphragm around the movable shaft large, the diaphragm can be more easily deformed with respect to a change in the pressure in the accommodation space of the actuator, and the absorption effect can be enhanced.

  In the active liquid-filled vibration isolator, the diaphragm may be bonded to the outer peripheral surface of the movable shaft by vulcanization bonding. Thereby, a movable shaft and a diaphragm can be combined, without providing a connection member etc. separately.

  In the active liquid-filled vibration isolator, the second fixture has a bottomed cylindrical shape, and the anti-vibration base is fixed to the opening side of the second fixture. In the axial direction, the vibration plate is disposed to face the vibration isolation base, the diaphragm is disposed to face the vibration plate, and the rubber-like elastic support portion is the vibration plate. The outer periphery of the rubber-like elastic support portion is bonded to the inner periphery of an annular member fixed to the second fixture side, and the inner periphery of the rubber-like elastic support portion is Bonded to the outer periphery of the vibration plate, the actuator is housed and held in a state of being sealed on the bottom side of the second fixture, and the movable shaft is provided so as to reciprocate in the axial direction of the second fixture. The vibration plate connected to the tip of the movable shaft is applied in the axial direction of the second fixture. It may be provided to.

  ADVANTAGE OF THE INVENTION According to this invention, the displacement of the vibration board by the temperature change of the sealed actuator accommodation space can be suppressed, and it can be made easy to always exhibit the original performance by an actuator.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view of an active liquid-filled vibration isolator according to a first embodiment assembled as an engine mount of an automobile. The liquid-filled vibration isolator includes an upper first fixture 10 attached to the engine side, a lower second fixture 12 having a bottomed cylindrical shape attached to a frame on the vehicle body side, and both fixtures 10. , 12, a vibration isolating base 14 made of a rubber-like elastic body, a first liquid chamber 16 in which the vibration isolating base 14 forms a part of the chamber wall, and another part of the chamber wall of the first liquid chamber 16. A vibration plate 18, an actuator 20 that drives the vibration plate 18 to control the pressure of the first liquid chamber 16, and a diaphragm 22 having a chamber wall partially made of a rubber film. A two-liquid chamber 24 and an orifice passage 26 for communicating the first liquid chamber 16 and the second liquid chamber 24 are provided.

  The first fixture 10 is a metal fitting that has a flange portion 10 </ b> A projecting radially outward at the upper end portion and is formed in a substantially truncated cone shape that tapers toward the lower end, and the axis L of the second fixture 12. The upper part of the second fixture 12 is spaced apart from the upper part. The first fixture 10 has a screw hole 10B on its upper surface, and a bolt (not shown) is screwed into the screw hole 10B so as to be connected to a bracket (not shown) on the engine side. .

  The second fixture 12 includes a cylindrical metal member 28 having a vibration-proof base 14 vulcanized and bonded to the inner periphery thereof, and a bottomed cylindrical metal member 30 that houses and holds the actuator 20. It consists of. Both members 28 and 30 are integrally formed by caulking and fixing the flange 30A projecting from the upper end opening of the holding member 30 so as to be wrapped by the caulking portion 28A projecting in a flange shape from the lower end of the cylindrical member 28. Has been.

  The holding member 30 includes a cylindrical first holding member 32 that constitutes the main body trunk portion, and a dish-like second holding member 34 that constitutes the bottom portion. The holding member 32 is integrally formed by fitting the lower end of the holding member 32 in a press-fitted state. A connecting bolt 36 projects downward from the bottom of the holding member 30, that is, the second holding member 34, and is configured to be connected to a frame (not shown) on the vehicle body side by the connecting bolt 36.

  The anti-vibration base 14 has a substantially umbrella shape that extends outward in the direction perpendicular to the axis toward the lower side, and is vulcanized and bonded to the upper end of the lower surface of the first fixture 10. Further, the vibration isolating base 14 is fixed to the upper opening side of the second fixture 12. Specifically, the lower end outer peripheral portion of the vibration isolating base 14 is on the entire circumference of the upper inner peripheral surface of the tubular member 28. It is vulcanized and bonded.

  The vibration plate 18 is a disk-shaped metal member, and is disposed to face the vibration isolation base 14 in the axial direction X of the second fixture 12. The vibration plate 18 is connected to the second fixture 12 side through an annular rubber-like elastic support portion 38 surrounding the vibration plate 18. More specifically, a metal annular member 42 is fitted to the inner periphery of the second fixture 12 via a seal rubber layer 40 continuous from the vibration isolation base 14. The rubber-like elastic support portion 38 is vulcanized and bonded to the inward flange portion 42A of the inner peripheral portion of the annular member 42 and the inner peripheral portion is vulcanized and bonded to the outer peripheral portion 18A of the vibration plate 18. Thus, the vibration plate 18 is supported by the second fixture 12 via the rubber-like elastic support portion 38.

  The diaphragm 22 is provided so as to be connected to the second fixture 12 on the opposite side of the first liquid chamber 16 with the excitation plate 18 interposed therebetween. In the axial direction X of the second fixture 12, the excitation plate 18 is provided. Are arranged opposite to each other. Specifically, the diaphragm 22 has an annular reinforcing metal fitting 44 embedded in the outer peripheral portion thereof, and the outer peripheral portion of the reinforcing metal fitting 44 is integrally fixed together with the flange 30 </ b> A of the holding member 30 by the caulking portion 28 </ b> A of the cylindrical member 28. Thus, the second fixture 12 is connected and fixed. The diaphragm 22 approaches the vibration plate 18 in the axial direction X with respect to the reinforcing bracket 44, and the trough portion 22 </ b> A on the outer peripheral side formed in a direction away from the vibration plate 18 in the axial direction X with respect to the reinforcing bracket 44. It is formed in a cross-sectional wave shape including an inner peripheral ridge 22B that bulges in the direction.

  The first liquid chamber 16 is a main liquid chamber (pressure receiving chamber) formed between the lower surface of the vibration isolation base 14 and the upper surface of the vibration plate 18 inside the second fixture 12. The second liquid chamber 24 is a sub liquid chamber (equilibrium chamber) that is provided between the vibration plate 18 and the diaphragm 22, and the vibration plate 18 and the diaphragm 22 form part of the chamber wall. Therefore, both the liquid chambers 16 and 24 are partitioned vertically by the vibration plate 18, that is, the vibration plate 18 functions as a partition wall that partitions both the liquid chambers 16 and 24 in the axial direction X.

  The orifice passage 26 for communicating the first liquid chamber 16 and the second liquid chamber 24 is provided along the circumferential direction of the second fixture 12 by the annular member 42. Specifically, the annular member 42 includes a circumferentially extending concave groove 42 </ b> B opened outward in a U-shaped cross section, and an orifice is formed between the inner circumferential surface of the second fixture 12 by the concave groove 42 </ b> B. A passage 26 is formed.

  The actuator 20 is an iron magnet movable type electromagnet type linear actuator, and is disposed on the opposite side of the first liquid chamber 16 with the vibration plate 18 interposed therebetween. More specifically, an actuator housing space 46 is provided on the opposite side of the diaphragm 22 from the second liquid chamber 24, and the actuator 20 is housed and held in the housing space 46. The actuator accommodating space 46 is defined by the diaphragm 22 and the holding member 30 corresponding to the bottom side of the second fixture 12, and is thus formed facing the diaphragm 22. The actuator housing space 46 is provided in a sealed state from the outside by the caulking and fixing of the diaphragm 22 to the second fixture 12 and the fixing and integration of the first holding member 32 and the second holding member 34 in the holding member 30. It has been.

  The actuator 20 includes a stator 48 fixed to the second fixture 12, and a movable shaft 50 that is supported so as to reciprocate relative to the stator 48 and is connected to the vibration plate 18 to drive the vibration. And is configured. As the actuator 20 itself, one having the same configuration as that described in Patent Document 1 can be used.

  The mover 50 is arranged in a vertical posture along the axis L of the second fixture 12 (coaxially in the example in the figure), and its tip 50A is vertically coupled to the center of the vibration plate 18. Thus, the vibration plate 18 is configured to vibrate in the axial direction X. On the outer peripheral surface of the mover 50, a magnetic material portion 52 is fixed as a mover iron core formed by laminating a large number of metal plates made of a magnetic metal such as an electromagnetic steel plate. Although only one magnetic material portion 52 can be provided as in the above-mentioned Patent Document 1, in this example, a plurality (three in the figure) are provided apart from each other in the axial direction X. The movable shaft 50 is reciprocable in the axial direction (vertical direction) X with respect to the stator 48 via a leaf spring 54 that is a pair of upper and lower elastic support members, and is positioned in the axial direction X. Is supported.

  The stator 48 is fitted and fixed to the inner peripheral surface of the first holding member 32. The stator 48 has an annular shape that surrounds the outer periphery of the movable shaft 50 coaxially. The hollow shaft has the movable shaft 50 in the axial direction X. Supports reciprocation. Specifically, the stator 48 opposes a yoke 56 in which a large number of annular metal plates made of a magnetic metal such as an electromagnetic steel plate are laminated and a magnetic material portion 52 at the center of the yoke 56. A pair of magnetic pole portions 58 projecting radially inward from both sides is provided.

  A pair of upper and lower surfaces facing the movable shaft 50 are arranged adjacent to the tip or inner end of the magnetic pole portion 58 of the stator 48 facing the magnetic material portion 52 in a state adjacent to the reciprocating direction (vertical direction) of the movable shaft 50. The permanent magnets 60 and 62 having an arc plate shape are arranged in a direction (left and right direction) orthogonal to the reciprocating direction so that the magnetic poles are NS alternating different poles, and the magnetic poles (N The poles and the S poles) are arranged in a reverse order. In this example, three pairs of the upper and lower permanent magnets 60 and 62 are arranged in the axial direction X so as to correspond to the magnetic material portion 52.

  A coil 64 is wound around each of the pair of magnetic pole portions 58 of the stator 48, that is, the coil 64 is wound around an axis in a direction orthogonal to the reciprocating direction, and the pair of permanent magnets 60, The magnetic flux passing through 62 can be generated. In this example, a pair of permanent magnets 60 and 62 are provided at the inner end portions of the pair of magnetic pole portions 58 of the stator 48 facing each other with the magnetic material portion 52 interposed therebetween, and the permanent magnets of the two magnetic pole portions 58 are respectively provided. 60 and 62 are opposed to each other with the movable shaft 50 sandwiched in a direction perpendicular to the reciprocating direction, and the magnetic poles are arranged in opposite directions so that the opposing magnetic poles are different from each other. .

  As a result, when a positive current flows through the coil 64, the direction of the magnetomotive force generated in the coil 64 and the direction of the magnetomotive force of the upper permanent magnet 60 are the same in the actuator 20, and the magnetomotive force is increased. On the other hand, the direction of the magnetomotive force of the lower permanent magnet 62 and the direction of the magnetomotive force of the coil 64 are opposite to each other, and the magnetomotive forces of the two are canceled and weakened. As a result, an upward force acts on the magnetic material portion 52 and the movable shaft 50 is raised. When a current in the reverse direction flows through the coil 64, the direction of the magnetomotive force of the upper permanent magnet 60 and the direction of the magnetomotive force of the coil 64 are opposite to each other, and the magnetic flux is offset. And the direction of the magnetomotive force of the lower permanent magnet 62 and the direction of the magnetomotive force of the coil 64 become the same, increasing the magnetomotive force. As a result, a downward force acts on the magnetic material portion 52 and the movable shaft 50 is lowered. Therefore, the movable shaft 50 reciprocates up and down by alternately changing the direction of the current of the coil 64 forward and backward.

  Next, a connection structure between the movable shaft 50, the vibration plate 18 and the diaphragm 22 will be described.

  By arranging the vibration plate 18 inside the diaphragm 22 as described above, the movable shaft 50 is coupled to the diaphragm 22 in a state of passing through the diaphragm 22, and its distal end portion 50 </ b> A is attached to the vibration plate 18. It is connected.

  Here, the connecting portion 66 of the movable shaft 50 to the vibration plate 18 has a top portion 68 </ b> A of the cap member 68 fitted to the tip portion 50 </ b> A of the movable shaft 50 and a concave portion 70 provided on the vibration plate 18. It is formed by fitting in. The distal end portion 50A of the movable shaft 50 is fixed to the cap member 68 by, for example, press fitting. The recessed portion 70 is a recessed portion opened downward so as to receive the small-diameter top portion 68 </ b> A on the upper surface of the cap member 68, and is formed so as to protrude toward the first liquid chamber 16. And the top part 68A of the cap member 68 is fixed to the said recessed part 70 by press-fitting, for example.

  On the other hand, the coupling portion 72 of the movable shaft 50 to the diaphragm 22 is formed by vulcanizing and bonding the diaphragm 22 to the outer peripheral surface of the movable shaft 50. The coupling portion 72 with the diaphragm 22 is provided away from the connecting portion 66 of the movable shaft 50 to the vibration plate 18 in the axial direction X of the movable shaft 50. That is, the diaphragm 22 is not fixed to the outer peripheral surface of the cap member 68 serving as the connecting portion 66 but at a position away from the connecting portion 66 in the axial direction X by a predetermined distance. It is fixed to the outer peripheral surface.

  Further, the inner peripheral surface of the diaphragm 22 fixed to the outer peripheral surface of the movable shaft 50, that is, the inner peripheral surface of the through-hole portion 74 through which the movable shaft 50 penetrates, is viewed from the axial direction of the movable shaft 50. It is formed smaller than the outer shape. In this example, since the through hole portion 74 and the vibration plate 18 are both circular, the diameter of the through hole portion 74 is set smaller than the outer diameter of the vibration plate 18. The outer shape of the diaphragm 22 is set larger than the outer shape of the rubber-like elastic support portion 38. In this example, since the outer shapes of the diaphragm 22 and the rubber-like elastic support portion 38 are both circular, the outer diameter of the diaphragm 22 is set larger than the outer diameter of the rubber-like elastic support portion 38.

  Reference numeral 76 denotes a terminal portion for energizing the coil 64.

  In the liquid-filled vibration isolator of the present embodiment configured as described above, when a large-amplitude low-frequency vibration occurs, the liquid passes through the orifice passage 26 and is between the first liquid chamber 16 and the second liquid chamber 24. The vibration can be damped by the liquid flow effect.

  When fine amplitude high frequency vibration is generated, the movable shaft 50 is moved up and down by flowing a sine wave alternating current through the coil 64 of the actuator 20 under the control of a control unit (not shown), and the vibration plate 18 connected thereto is moved. Is given a vibration of a sinusoidal curve, thereby controlling the pressure of the first liquid chamber 16. For example, when the first fixture 10 vibrates in the axial direction X due to vibration from the engine, the hydraulic pressure in the first fluid chamber 16 is increased by the downward displacement of the first fixture 10 in synchronization with this vibration. By displacing the vibration plate 18 downward as it is, vibration transmission to the vehicle body side can be reduced.

  In the present embodiment, the actuator housing space 46 faces the diaphragm 22 and does not face the vibration plate 18, so that the air pressure in the housing space 46 changes due to a temperature change. In addition, the change in the atmospheric pressure can be absorbed by the deformation of the diaphragm 22, and the displacement of the vibration plate 18 can be suppressed.

  In particular, with respect to the movable shaft 50 that passes through the diaphragm 22 and is connected to the vibration plate 18, the connecting portion 72 with the diaphragm 22 is separated in the axial direction X with respect to the connection portion 66 to the vibration plate 18. The vibration plate 18 and the diaphragm 22 are provided separately in the axial direction X. Therefore, it is easy to deform only the diaphragm 22 independently of the vibration plate 18 with respect to a change in pressure in the actuator housing space 46 due to a temperature change. Therefore, the pressure change can be effectively absorbed by the diaphragm 22, and the displacement suppressing effect of the vibration plate 18 is excellent.

  Further, by setting the diameter of the through hole portion 74 of the diaphragm 22 to be smaller than the outer diameter of the vibration plate 18 and setting the flexible film portion of the diaphragm 22 around the movable shaft 50, the actuator housing space 46 is set. The diaphragm 22 can be more easily deformed with respect to the atmospheric pressure change, and the absorption effect can be enhanced.

  As described above, according to the present embodiment, displacement of the vibration plate 18 (positional displacement in the axial direction X) due to a temperature change in the sealed actuator housing space 46 can be effectively suppressed. Therefore, the positional deviation from the origin of the movable shaft 50 can be suppressed, and the relative positional relationship between the movable shaft 50 and the stator 48 can be suppressed. Therefore, the relative displacement between the mover 50 and the stator 48 can be suppressed and the original performance of the actuator 20 can always be exhibited without being affected by the temperature change in the actuator housing space 46.

  Further, according to the embodiment, since the diaphragm 22 is directly bonded to the outer peripheral surface of the movable shaft 50 by vulcanization, it is not necessary to separately provide a connecting member or the like, and the cost can be reduced.

(Second Embodiment)
FIG. 2 is a sectional view of an active liquid-filled vibration isolator according to the second embodiment. The second embodiment differs from the first embodiment in the configuration of the movable shaft 50.

  In this example, the movable shaft 50 includes an upper first shaft portion 80 connected to the vibration plate 18 and the diaphragm 22, and a lower second shaft portion 82 disposed inside the stator 48. The first shaft portion 80 and the second shaft portion 82 are connected by magnets 84 and 86. Specifically, a disk-shaped first connection surface portion 88 is provided at the lower end of the first shaft portion 80, and a permanent magnet 84 is embedded in the first connection surface portion 88. Further, a second connecting surface portion 90 with a peripheral wall for receiving the first connecting surface portion 88 is provided at the upper end of the second shaft portion 82 connected to the second shaft portion 82, and the permanent magnet 84 is provided on the second connecting surface portion 90. And permanent magnets 86 that are opposed to each other with different polarities are embedded.

  In this embodiment, the movable shaft 50 is made into two members, and both the members 80 and 82 are connected and fixed by the magnets 84 and 86. Therefore, the shift of the axial center between the vibration plate 18 side and the stator 48 side of the movable shaft 50 is achieved. Easy to absorb and excellent in manufacturing workability. In the example of FIG. 2, the magnets 84 and 86 are provided on both the first shaft portion 80 and the second shaft portion 82. However, if the magnet is provided on at least one of the two shaft portions 80, 82 can be connected and fixed.

  Other configurations and operational effects of the second embodiment are the same as those of the first embodiment. In FIG. 2, portions denoted by the same reference numerals as those in FIG. 1 have the same configuration and description thereof is omitted.

(Third embodiment)
FIG. 3 is a sectional view of an active liquid-filled vibration isolator according to the third embodiment. The third embodiment differs from the first embodiment in the shape of the diaphragm 22.

  In this example, the diaphragm 22 is a single curved portion that slightly swells in a direction approaching the vibration plate 18 in the axial direction X between the outer peripheral reinforcing metal piece 44 and the inner peripheral through hole 74. The bulge amount in the axial direction X is set smaller than that of the first embodiment.

  Thereby, according to this embodiment, the deformation width in the axial direction X of the diaphragm 22 can be reduced, and the space can be reduced, so that the vibration damping device as a whole can be made compact.

  Other configurations and operational effects of the third embodiment are the same as those of the first embodiment. In FIG. 3, the portions denoted by the same reference numerals as those in FIG.

  The present invention can be used for various vibration isolators including an engine mount, and can be applied to, for example, a mount provided between a suspension member and a vehicle body side frame.

1 is a longitudinal sectional view of an active liquid-filled vibration isolator according to a first embodiment. Vertical sectional view of an active liquid-filled vibration isolator according to the second embodiment Vertical sectional view of an active liquid-filled vibration isolator according to the third embodiment Longitudinal sectional view of an active liquid filled vibration isolator according to a conventional example Longitudinal sectional view of an active liquid-filled vibration isolator according to a comparative example

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... 1st fixture 12 ... 2nd fixture 14 ... Anti-vibration base | substrate 16 ... 1st liquid chamber 18 ... Excitation board, 18A ... Outer peripheral part 20 ... Actuator 22 ... Diaphragm 24 ... 2nd liquid chamber 26 ... Orifice passage 38 ... rubber-like elastic support part 42 ... annular member 46 ... actuator housing space 48 ... stator 50 ... movable shaft, 50A ... tip part 66 ... connecting part 72 of movable shaft to vibration plate ... coupling part of movable shaft to diaphragm X ... axial direction

Claims (4)

A first fixture;
A second fixture;
An anti-vibration base made of a rubber-like elastic body that connects the first fixture and the second fixture;
A first liquid chamber in which the vibration-proof substrate forms a part of a chamber wall;
A vibration plate that forms another part of the chamber wall of the first liquid chamber and is connected to the second fixture side through a rubber-like elastic support portion;
An actuator disposed on the opposite side of the first liquid chamber across the vibration plate to drive the vibration plate to vibrate;
The actuator constituting the actuator, the stator fixed to the second fixture side, and supported so as to be reciprocable with respect to the stator and coupled to the vibration plate, the vibration plate A movable shaft that vibrates and drives,
A diaphragm made of a rubber-like elastic film provided on the opposite side of the first liquid chamber to the second fixture side across the vibration plate;
A second liquid chamber provided between the vibration plate and the diaphragm and having the vibration plate and the diaphragm as a part of a chamber wall;
An orifice passage communicating the first liquid chamber and the second liquid chamber;
With
The actuator housing space is provided in a state of being sealed from the outside on the opposite side of the second liquid chamber across the diaphragm,
The movable shaft is coupled to the diaphragm in a state of penetrating the diaphragm, and the coupling portion of the movable shaft to the diaphragm is an axis of the movable shaft with respect to the coupling portion of the movable shaft to the vibration plate. Provided apart in the direction of the heart,
Active liquid-filled vibration isolator. The inner peripheral surface of the diaphragm fixed to the outer peripheral surface of the movable shaft is formed smaller than the outer shape of the vibration plate in the axial direction of the movable shaft.
2. An active liquid-filled vibration isolator according to claim 1. The diaphragm was bonded to the outer peripheral surface of the movable shaft by vulcanization bonding,
The active liquid-filled vibration isolator according to claim 1 or 2. The second fixture has a bottomed cylindrical shape, and the vibration isolation base is fixed to the opening side of the second fixture, and faces the vibration isolation base in the axial direction of the second fixture. The vibration plate is disposed, and the diaphragm is disposed opposite the vibration plate,
The rubber-like elastic support portion forms an annular shape surrounding the vibration plate, and an outer peripheral portion of the rubber-like elastic support portion is bonded to an inner peripheral portion of an annular member fixed to the second fixture side, and the rubber The inner peripheral part of the elastic support part is bonded to the outer peripheral part of the vibration plate,
The actuator is housed and held in a sealed state on the bottom side of the second fixture, and the movable shaft is provided so as to be able to reciprocate in the axial direction of the second fixture. The connected vibration plate is provided to vibrate in the axial direction of the second fixture,
The active liquid-filled vibration isolator according to any one of claims 1 to 3.

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