JP6471996B2 - Active vibration isolator - Google Patents

Description

  The present invention relates to an active vibration isolator, and more particularly to an active vibration isolator capable of limiting displacement in the axial direction of a drive shaft of an actuator.

  A rubber-like anti-vibration base that connects the first fixture and the cylindrical second fixture, a liquid chamber in which the anti-vibration base forms at least a part of the chamber wall, and another chamber wall of the liquid chamber A vibration body provided at a position facing the vibration-proof base, and an actuator that is disposed on the opposite side of the liquid chamber with the vibration body interposed therebetween and that vibrates the vibration body in the axial direction by a drive shaft, There is known an active vibration isolator capable of attenuating vibration of a vibrating body by vibrating the vibrating body in the axial direction (Patent Document 1). In the technique disclosed in Patent Document 1, a stopper portion that protrudes in a direction perpendicular to the axis is provided on the drive shaft, while a stopper portion that protrudes inward in the radial direction is provided on the second fixture. The stopper portion and the stopper portion interfere with each other due to the axial displacement of the drive shaft, whereby the axial displacement of the drive shaft of the actuator can be limited.

JP 2010-43701 A

  However, the conventional technology described above has a problem that the space occupied by the stopper portion is large.

  The present invention has been made to solve the above-described problems, and provides an active vibration isolator capable of limiting the axial displacement of the drive shaft of the actuator and reducing the space occupied by the stopper portion. It is aimed.

Means for Solving the Problems and Effects of the Invention

  In order to achieve this object, according to the active vibration isolator according to claim 1, the first fixture and the cylindrical second fixture are connected by a vibration isolating base composed of a rubber-like elastic body, The vibration isolating base constitutes at least a part of the chamber wall of the first liquid chamber, and the vibration exciter constitutes a part of another chamber wall of the first liquid chamber. The vibration exciter is connected to the second fixture side and is provided at a position facing the vibration isolation base in the axial direction of the second fixture. The vibrating body is a pair of partitions in which an elastic wall made of a rubber-like elastic body is connected to the second fixture side, and is connected to each other via a connecting portion that penetrates the radial center of the elastic wall in the thickness direction. The plate sandwiches the elastic wall from both sides in the axial direction. The actuator arranged on the opposite side of the first liquid chamber across the vibration body in the axial direction of the second fixture vibrates the vibration body in the axial direction by the drive shaft. The stopper portion provided on the second fixture side protrudes inward in the radial direction. The pair of partition plates are disposed on both sides of the stopper portion in the axial direction of the second fixture, and both the stopper portions partially overlap with each other in the axial projection. Therefore, the axial displacement of the drive shaft of the actuator can be limited by the interference between the pair of partition plates and the stopper portion. Since the stopper portion is disposed between the pair of partition plates, the space occupied by the stopper portion can be reduced.

Scan stopper portion is circumferentially provided intermittently. Therefore, the spring at the base portion of the elastic wall can be softened as compared with the case where the stopper portion is continuously provided in the circumferential direction. Therefore , there is an effect that the actuator can easily reciprocate the partition plate in the axial direction.

According to the active vibration damping device according to claim 2, the inner edge portion provided in the second fixture side, protrudes from between the stopper portion radially inward. The inner edge portion is set to have a radial length smaller than the radial length of the stopper portion, and is positioned radially outward of the partition plate in the axial projection, so that it is more elastic than the case without the inner edge portion. The rigidity of the base of the wall can be improved. As a result, in addition to the effect of claim 1 can improve the effect of regulating the example displacement of the partition plate when the large amplitude vibration in a low frequency range is inputted from the first fixture and the second fixture.

According to the active vibration isolator of claim 3 , the first fixture and the cylindrical second fixture are connected by the vibration isolating base made of a rubber-like elastic body, and at least the chamber of the first liquid chamber. A vibration isolating base constitutes a part of the wall, and a vibration exciter constitutes a part of another chamber wall of the first liquid chamber. The vibration exciter is connected to the second fixture side and is provided at a position facing the vibration isolation base in the axial direction of the second fixture. The vibrating body is a pair of partitions in which an elastic wall made of a rubber-like elastic body is connected to the second fixture side, and is connected to each other via a connecting portion that penetrates the radial center of the elastic wall in the thickness direction. The plate sandwiches the elastic wall from both sides in the axial direction. The actuator arranged on the opposite side of the first liquid chamber across the vibration body in the axial direction of the second fixture vibrates the vibration body in the axial direction by the drive shaft. The stopper portion provided on the second fixture side protrudes inward in the radial direction. The pair of partition plates are disposed on both sides of the stopper portion in the axial direction of the second fixture, and both the stopper portions partially overlap with each other in the axial projection. Therefore, the axial displacement of the drive shaft of the actuator can be limited by the interference between the pair of partition plates and the stopper portion. Since the stopper portion is disposed between the pair of partition plates, the space occupied by the stopper portion can be reduced.
The elastic wall is a portion located radially inward from the protruding end of the stopper portion, and the concave portion is provided on the wall surface facing the partition plate. Therefore, the spring of the elastic wall can be softened by the concave portion. Therefore , for example, when a fine amplitude vibration in a high frequency range is input from the first fixture or the second fixture, the partition plate can be easily reciprocated in the axial direction, and the dynamic spring constant can be reduced.

Concave portion, a bottom portion at a position overlapping the stopper portion in the projection of the axis-perpendicular direction is formed. As a result, it is possible to make it difficult for stress concentration due to the recesses to occur while ensuring the effect of softening the springs of the elastic walls by the recesses. As a result , there is an effect that the fatigue of the elastic wall can be suppressed.
According to the active vibration isolator of the fourth aspect, the diaphragm constituted by the rubber-like elastic body connected to the second fixture side has the first vibration member sandwiched in the axial direction of the second fixture. It is arranged on the opposite side of the liquid chamber. The diaphragm and the vibrating body constitute at least a part of the chamber wall of the second liquid chamber. The annular orifice forming member disposed inside the second fixture forms an orifice that communicates the second liquid chamber and the first liquid chamber. The stopper portion protrudes radially inward from the inner peripheral surface of the orifice forming member, and the elastic wall is connected to the inner peripheral surface of the orifice forming member. Therefore, in addition to the effect of any one of claims 1 to 3, there is an effect that an increase in the number of parts can be suppressed as compared with the case where the stopper portion is provided as a separate member.

It is an axial sectional view of the active vibration isolator in the first embodiment of the present invention. It is an axial sectional view of a partition. It is an exploded view of a partition. It is a perspective view of an orifice formation member. It is a perspective view of the orifice formation member of the active vibration isolator in 2nd Embodiment. It is a top view of a partition. It is an axial sectional view of the partition body in the VII-VII line of FIG.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, the structure of the active vibration isolator 10 will be described with reference to FIG. FIG. 1 is an axial sectional view of an active vibration isolator 10 according to a first embodiment of the present invention. FIG. 1 illustrates a state before the engine is supported (that is, a state before the weight of the engine is loaded).

  The active vibration isolator 10 is a vibration isolator for supporting and fixing an automobile engine (vibrating body, not shown) and preventing the engine vibration from being transmitted to a vehicle body frame (not shown). As shown in FIG. 1, the first fixture 11 attached to the engine side, the cylindrical second fixture 12 attached to the vehicle body frame side below the engine, and a rubber-like elastic body are connected. A liquid chamber (a first liquid chamber 19 and a second liquid chamber 20) is formed between the anti-vibration base 15 and the anti-vibration base 15 attached to the second fixture 12 and is made of a rubber-like elastic body. The diaphragm 17, the drive shaft 32 connected to the diaphragm 17, the actuator 30 disposed on the opposite side of the liquid chamber across the diaphragm 17, and the axial direction by the drive shaft 32 of the actuator 30. And a pressure isolator 70 which is vibration displacement.

  The first fixture 11 is a member formed in a substantially cylindrical shape from a metal material such as an aluminum alloy, and has a bolt projecting upward from its upper end surface. The first fixture 11 is attached to the engine side via this bolt. The second fixture 12 includes a cylindrical fitting 13 in which the vibration-proof base 15 is vulcanized and a bottom fitting 14 fixed to the lower portion of the cylindrical fitting 13 by caulking. The cylindrical metal fitting 13 is formed in a cylindrical shape having an opening extending upward, and the bottom metal fitting 14 is formed in a cup shape having a bottom portion, respectively, from a steel material or the like. A bolt projects downward from the bottom of the bottom metal fitting 14. The second fixture 12 is attached to the vehicle body via the bolt.

  The anti-vibration base 15 is a member formed in a truncated cone shape from a rubber-like elastic body, and is vulcanized and bonded between the lower surface side of the first fixture 11 and the upper end opening of the cylindrical fitting 13. A rubber film 16 covering the inner peripheral surface of the cylindrical metal fitting 13 is connected to the lower end portion of the vibration isolating base 15.

  The diaphragm 17 is formed as a rubber film bent in a bellows shape from a rubber-like elastic body. The outer periphery of the diaphragm 17 is vulcanized and bonded to an annular mounting plate 18 when viewed from above. The circumference is vulcanized. The diaphragm 17 is attached to the second fixture 12 by the mounting plate 18 being clamped and fixed together with the bottom fitting 14 by the cylindrical fitting 13. As a result, a liquid chamber is formed between the upper surface side of the diaphragm 17 and the lower surface side of the vibration isolation base 15. An antifreeze liquid (not shown) such as ethylene glycol is sealed in the liquid chamber.

  The partition 50 is a member for partitioning the liquid chamber, and is disposed between the vibration isolating base 15 and the diaphragm 17. The partition 50 includes an orifice forming member 51 and a vibration body 70 formed so as to be reciprocally movable in the axial direction. In the partition 50, the outer peripheral surface of the orifice forming member 51 is in close contact with the rubber film 16, so that the vibration isolating base 15 forms a part of the chamber wall, and the diaphragm 17 forms a part of the chamber wall. The liquid chamber is partitioned into two chambers including the second liquid chamber 20 constituting In addition, an orifice 21 that connects the first liquid chamber 19 and the second liquid chamber 20 is formed between the orifice forming member 51 and the cylindrical fitting 13. The vibrating body 70 is vibrated by the actuator 30.

  The actuator 30 is an iron core movable type electromagnet type linear actuator, and is housed and held in a housing space formed by the bottom metal fitting 14 while being sealed from the outside. The actuator 30 includes a stator 31 fixed to the second fixture 12, and a mover 33 that is supported so as to be able to reciprocate with respect to the stator 31 and is connected to the vibrating body 70. The mover 33 is a shaft-like member disposed in a vertical position along the axis O of the second fixture 12 (coaxially in the present embodiment), and the tip thereof is attached to the vibrating body 70. The movable member 33 and the shaft-shaped member 34 are integrally connected to the attached shaft-shaped member 34, and the vibration exciter 70 is vertically displaced (reciprocated) along the axis O direction.

  The drive shaft 32 includes a mover 33, a shaft member 34, and a bolt. The mover 33 is formed in a cylindrical shape having a through-hole along the axis O, while the shaft-shaped member 34 has a threaded portion that is open on the proximal end side and has a female screw formed on the inner peripheral surface thereof. The front end of the bolt inserted from the base end side of the mover 33 is screwed into the female thread portion of the shaft-shaped member 34, whereby the mover 33 and the shaft-shaped member 34 are integrally connected, and the drive shaft 32 is configured. Is done. In the present embodiment, the shaft-shaped member 34 is formed of synthetic resin.

  The mover 33 has a magnetic material portion 35 as a mover core formed by laminating a large number of metal plates made of a magnetic metal such as an electromagnetic steel plate on the outer peripheral surface. A plurality of magnetic material portions 35 (two in the present embodiment) are provided with a predetermined interval in the direction of the axis O. The mover 33 can reciprocate in the direction of the axis O with respect to the stator 31 via a leaf spring 36 that is a pair of upper and lower elastic support members, and the position of the axis O and the axis O are orthogonal to each other. It is supported in a state where the direction position is positioned.

  The stator 31 has an annular shape that coaxially surrounds the outer periphery of the mover 33, and supports the mover 33 so that it can reciprocate in the direction of the axis O in its hollow portion. It is held in a lowered state. The mounting plate 37 is caulked and fixed by the bottom metal fitting 14 together with the cylindrical metal fitting 13 and the attachment plate 18 of the diaphragm 17.

  The stator 31 is arranged in a radial direction from both sides so as to face each other with a yoke 38 formed by laminating a large number of annular metal plates made of a magnetic metal such as an electromagnetic steel plate with a magnetic material portion 35 interposed therebetween at the central portion of the yoke 38. A pair of magnetic pole portions 39 projecting inward is provided.

  The tip of the magnetic pole portion 39 of the stator 31 facing the magnetic material portion 35 (that is, the inner end of the magnetic pole portion 39) is adjacent to the movable member 33 along the reciprocating direction (axis O direction). A pair of upper and lower permanent magnets 40 and 41 facing the mover 33 while being arranged side by side are perpendicular to the reciprocating direction of the mover 33 so that their magnetic poles are NS different from each other. The magnetic poles are arranged in the direction, and the arrangement of the magnetic poles (N pole and S pole) is reversed. In the present embodiment, two pairs of upper and lower permanent magnets 40 and 41 are arranged side by side in the axial center O direction so as to correspond to the magnetic material portion 35.

  Around the pair of magnetic pole portions 39 of the stator 31, a coil 42 is wound around an axis center in a direction perpendicular to the reciprocating direction (axis O direction) of the mover 33, and a pair of permanent magnets. The magnetic flux passing through 40 and 41 can be generated. In the present embodiment, a pair of permanent magnets 40 and 41 are provided at inner end portions of the pair of magnetic pole portions 39 of the stator 31 facing each other with the magnetic material portion 35 interposed therebetween. The magnetic poles are opposed to each other in a direction orthogonal to the reciprocating direction of the movable element 33, and the magnetic poles are arranged so that the opposing magnetic poles are different from each other so that the opposing magnetic poles are different from each other (left and right in FIG. 1). It is installed.

  When the coil 42 of the actuator 30 is in a demagnetized state, the drive shaft 32 supported so as to be displaceable in the axial center O direction (axial direction) with respect to the stator 31 is supported by the leaf spring 36 and stopped. When a positive exciting current is passed through the coil 42 from this state, the direction of the magnetomotive force generated in the coil 42 is the same as the direction of the magnetomotive force of the upper permanent magnet 40, and the magnetomotive force is increased. On the other hand, the direction of the magnetomotive force of the lower permanent magnet 41 and the direction of the magnetomotive force of the coil 42 are opposite to each other, and the magnetomotive forces of both are offset and weakened. As a result, an upward force acts on the magnetic material portion 35, and the mover 33 rises while elastically deforming the leaf spring 36. Since the vibrating body 70 coupled to the mover 33 moves upward, the volume of the first liquid chamber 19 decreases.

  On the other hand, when an exciting current in the reverse direction is supplied to the coil 42, contrary to the above, a downward force acts on the magnetic material portion 35, and the mover 33 descends while elastically deforming the leaf spring 36. Since the vibrating body 70 coupled to the mover 33 moves downward, the volume of the first liquid chamber 19 increases. Thus, by alternately switching the direction of the excitation current of the coil 42 in the forward and reverse directions, the volume of the first liquid chamber 19 can be changed by exciting the drive shaft 32 and the vibrating body 70 up and down.

  Next, the partition 50 will be described with reference to FIGS. 2 is an axial sectional view of the vibrating body 50, FIG. 3 is an exploded view of the partition body 50, and FIG. 4 is a perspective view of the orifice forming member 51. As shown in FIG. 2, the partition 50 includes an annular orifice forming member 51 disposed inside the second fixture 12 and a vibrating body 70 that blocks a portion surrounded by the inner peripheral surface 62 of the orifice forming member 51. And. The vibrating body 70 is composed of a rubber-like elastic body and has an elastic wall 71 having an outer peripheral surface vulcanized and bonded to the inner peripheral surface 62 of the orifice forming member 51, and a pair of sandwiching the elastic wall 71 from both sides in the axial direction. Partition plates 80 and 90 are provided.

  The orifice forming member 51 is a member made of a rigid body for forming the orifice 21 extending in the circumferential direction between the inner peripheral surface (rubber film 16) of the second fixture 12 and, as shown in FIG. An annular wall portion 52 disposed orthogonal to the center O, a cylindrical body portion 54 that is continuous with the inner periphery of the wall portion 52 and extends in the direction of the axis O (axial direction), and the body portion 54 And a wall portion 55 projecting in a flange shape outward in the radial direction from the lower end portion. The orifice forming member 51 has a notch 53 and an opening 56 formed in the walls 52 and 55, respectively. Since the vertical wall 57 is provided to connect the wall portions 52, 55 and the body portion 54 and separate the notch 53 and the opening 56, the orifice 21 is divided in the circumferential direction by the vertical wall 57, and the notch 53 is interposed therebetween. While communicating with the first liquid chamber 19, it communicates with the second liquid chamber 20 through the opening 56. That is, the orifice 21 having a flow path length of about one round from the notch 53 to the opening 56 is formed.

  The orifice forming member 51 is provided with an annular extending portion 58 extending on the opposite side of the body portion 54 with the wall portion 52 interposed therebetween in the axial direction, and has a bowl shape extending radially inward from the extending portion 58. A stopper portion 59 is provided to project. The stopper portion 59 is provided continuously in the circumferential direction over the entire circumference of the extending portion 58. In the stopper portion 59, the radial length from the protruding end 60 of the stopper portion 59 to the extending portion 58 (the length in the direction perpendicular to the axis perpendicular to the axis O) is set to be the same in the circumferential direction. ing.

  Returning to FIG. 2 and FIG. The orifice forming member 51 is provided with an annular convex portion 61 on the radially inner side of the extending portion 58 opposite to the wall portion 52 across the extending portion 58 and on the body portion 54 side from the stopper portion 59. Yes. The convex portion 61 is set to have a radial length (length in a direction perpendicular to the axis) smaller than a radial length from the protruding end 60 of the stopper portion 59 to the extending portion 58.

  The outer peripheral surface of the elastic wall 71 is vulcanized and bonded to the extended portion 58 of the orifice forming member 51, the inner peripheral surface 62 of the convex portion 61, and the stopper portion 59 protruding from the inner peripheral surface 62. The elastic wall 71 is formed with a circular central hole 72 that penetrates the center in the radial direction in the thickness direction (axial center O direction). It is provided around. The elastic wall 71 has a larger axial thickness near the orifice forming member 51 than an axial thickness near the ridge 73 (distance between the wall surfaces 75 and 76). An annular raised portion 74 that is raised in the direction of the axis O is provided.

  The elastic wall 71 has a concave portion 77 that is recessed in the axial direction on one of the wall surfaces 75 and 76 formed in a curved surface. The recess 77 is provided at a portion located radially inward from the protruding end 60 of the stopper portion 59, and a plurality (six in the present embodiment) are provided at regular intervals in the circumferential direction of the elastic wall 71. It has been. The concave portion 77 is formed in a substantially arc shape when viewed in the axial direction, and the bottom portion 78 that is most deeply depressed in the axial direction overlaps with the stopper portion 59 in the projection perpendicular to the axial direction (the length of the axial length of the stopper portion 59). Range). The concave portion 77 is provided on the outer peripheral side from the midpoint of the line segment connecting the axis O passing through the center of the elastic wall 71 (the center of the central hole 72) and the inner peripheral surface of the convex portion 61 of the orifice forming member 51. ing.

  The pair of partition plates 80 and 90 are substantially circular members whose outer shape is set smaller than the outer shape of the elastic wall 71 when viewed in the axial direction, and the central portions 81 and 91 and the outer peripheral portions 84 and 94 are made of thermoplastic resin, respectively. It is molded integrally. The center portions 81 and 91 are respectively formed with annular grooves 82 and 92 into which both axial sides of the protrusion 73 of the elastic wall 71 are fitted. In the partition plate 90, a connecting portion 93 that protrudes in the axial direction is provided at the center of the central portion 91, and the partition plate 80 has a fitting recess 83 in which the connecting portion 93 fits in the center of the central portion 81. Is formed. The partition plates 80 and 90 are connected by being fixed by ultrasonic welding in a state in which the connecting portion 93 is fitted in the fitting recess 83, and the elastic wall 71 is sandwiched from both sides in the axial direction by the partition plates 80 and 90.

  The partition plate 80 constitutes part of the chamber wall of the first liquid chamber 19 (see FIG. 1), and the partition plate 90 constitutes part of the chamber wall of the second liquid chamber 20. The amount of axial displacement of the partition plates 80 and 90 is restricted by the elastic wall 71. The tip of the shaft-like member 34 (see FIG. 1) is fitted into the recess on the back side of the connecting portion 93 formed at the center of the partition plate 90. The shaft-shaped member 34 is fixed to the partition plate 90 by ultrasonic welding in a state where the tip is inserted into the recess of the partition plate 90.

  The outer peripheral portions 84 and 94 are such that the radially inner surfaces are in close contact with the wall surfaces 75 and 76 of the elastic wall 71, and the axial gaps 85 and 95 with the wall surfaces 75 and 76 gradually increase toward the radially outer side. Is curved. The concave portion 77 formed in the elastic wall 71 is a neutral position where no load is applied to the elastic wall 71, and the edge (wall surface 76) on the outer side in the radial direction is not in close contact with the partition plate 90. There is a gap between them.

  The partition plates 80 and 90 are disposed on both sides of the stopper portion 59 in the axial direction, and the outer peripheral portions 84 and 94 are curved to provide an axial interval with the stopper portion 59. Moreover, the partition plates 80 and 90 are set to a size and a shape so as to partially overlap the stopper portion 59 in the axial projection.

  A method of manufacturing the active vibration isolator 10 (see FIG. 1) configured as described above will be described. A first molded body in which the first fixture 11 and the cylindrical fitting 13 are connected by a vibration-proof base 15, the diaphragm 17 is vulcanized, and the mounting plate 18 and the shaft-shaped member 34 are vulcanized and bonded. The two molded bodies are each vulcanized and molded with a rubber vulcanization mold. Further, the elastic wall 71 is vulcanized and formed on the orifice forming member 51 by another rubber vulcanizing mold, and then the partition plates 80 and 90 are assembled to form the partition body 50. Next, the shaft-shaped member 34 of the second molded body is fixed to the partition plate 90 of the partition body 50 to form an intermediate assembly.

  Next, the intermediate assembly and the first molded body are submerged in the liquid, and after inserting the intermediate assembly into the cylindrical metal fitting 13 from the lower opening of the first molded body, the cylindrical metal fitting 13 is compressed. Diameter processing is performed, and the intermediate assembly is attached to the cylindrical metal fitting 13. Thereafter, in a posture in which the first fixture 11 is in a downward position, this member is taken out of the liquid, and while maintaining this posture, the actuator 30 is overlapped from the lower surface side of the diaphragm 17, and the shaft-like member 34 and the mover 33 are attached. Fasten with bolts. Next, the bottom metal 14 is put on the actuator 30 and the bottom metal 14 is fixed to the lower opening of the cylindrical metal 13 by caulking. Thereby, the manufacture of the active vibration isolator 10 is completed.

  Next, the operation of the active vibration isolator 10 will be described. When a relatively large amplitude low-frequency vibration is input from the first fixture 11 or the second fixture 12, the operation of the actuator 30 is controlled by a control device (not shown) that controls the active vibration isolator 10. Stopped. In this state, the amount of displacement of the partition plates 80 and 90 is restricted by the elastic wall 71, so that the liquid is provided between the first liquid chamber 19 and the second liquid chamber 20 via the orifice 21 formed in the partition body 50. Circulate. The active vibration isolator 10 can dampen vibration by the liquid flow effect of the orifice 21.

  On the other hand, when a relatively small high-frequency amplitude is input from the first fixture 11 or the second fixture 12, a control device (not shown) applies a sinusoidal AC voltage or a rectangular wave to the coil 42 of the actuator 30. An AC voltage or the like is applied, the movable element 33 (that is, the drive shaft 32) is reciprocated up and down, and the vibration body 70 connected to the drive shaft 32 is subjected to vibration displacement in an opposite phase to the input vibration. As a result, the partition plates 80 and 90 integrally reciprocate to absorb the hydraulic pressure in the first liquid chamber 19 and reduce vibration.

  According to the active vibration isolator 10, the elastic wall 71 has a stopper portion 59 that protrudes radially inward from the orifice forming member 51 and is embedded in the base portion. The effect of restricting the displacement of the partition plates 80 and 90 at the time of low frequency and large amplitude can be improved. As a result, the vibration damping effect due to the liquid flow effect of the orifice 21 can be secured. In addition, since the convex portion 61 protruding radially inward is provided in the orifice forming member 51, the rigidity of the base portion of the elastic wall 71 is increased, and the partition plates 80 and 90 at the time of low frequency and large amplitude. The effect which regulates the displacement of can be improved. Further, the raised portion 74 also has an effect of increasing the rigidity of the base portion of the elastic wall 71.

  The partition plates 80 and 90 that sandwich the elastic wall 71 from both sides in the axial direction are disposed on both sides of the stopper portion 59, and both of them overlap the stopper portion 59 in the axial projection. Therefore, the axial displacement of the drive shaft 32 of the actuator 30 can be limited by the interference between the partition plates 80 and 90 and the stopper portion 59. That is, the stopper portion 59 can prevent the diaphragm 17 and the elastic wall 71 from being damaged when the actuator 30 becomes uncontrollable and runs away, and can prevent the actuator 30 from being damaged when a large amplitude vibration is input.

  Since the stopper part 59 is arrange | positioned between the partition plates 80 and 90, the space which the stopper part 59 occupies can be made small. Therefore, it is possible to suppress an increase in the axial dimension of the means for restricting the axial displacement of the drive shaft 32. Further, since it is not necessary to newly secure a space for providing the stopper portion 59, the active vibration isolator 10 can be made compact.

  Furthermore, since the active vibration isolator 10 can restrict the displacement by the stopper portion 59 using the partition plates 80 and 90 constituting the chamber wall of the liquid chamber, the addition of new members can be suppressed, and the number of parts can be increased. Increase in product cost can be suppressed. In particular, since the active vibration isolator 10 is provided with the stopper portion 59 on the orifice forming member 51, an increase in the number of parts can be suppressed as compared with the case where the stopper portion is provided as a separate member. Moreover, when the stopper part 59 functions, since a part (rubber-like elastic body) of the elastic wall 71 is interposed between the stopper part 59 and the partition plates 80 and 90, the generation of abnormal noise can be suppressed.

  The elastic wall 71 is a portion located radially inward from the projecting end 60 of the stopper portion 59, and the concave portion 77 is provided in the wall surface 76 facing the partition plate 90. Can be softened. Therefore, the partition plates 80 and 90 can be easily reciprocated in the axial direction by the actuator 30.

  Since the concave portions 77 are intermittently provided in the circumferential direction of the wall surface 76 of the elastic wall 71, the partition plates 80 and 90 vibrate in the axial direction at portions between the adjacent concave portions 77 (portions not depressed). The state of being in contact with the partition plate 90 can be maintained even while being performed. Therefore, it is possible to suppress abnormal noise caused by the hitting sound between the elastic wall 71 and the partition plate 90.

  Further, at the neutral position where no load is applied to the elastic wall 71, a gap is secured between the partition plate 90 without the radially outer edge (wall surface 76) of the recess 77 being in close contact with the partition plate 90. Therefore, the gap can have a function as a high-frequency orifice that operates in a higher frequency range than the orifice 21. In this portion, liquid resonance in a specific frequency band is generated, and the dynamic spring constant of the frequency band can be reduced. The characteristics can be tuned by changing the number and size of the recesses 77 and the size and length of the gap. During large amplitude vibration, the partition plate 90 is displaced in the axial direction, so that the gap is closed by the partition plate 90. Therefore, high attenuation performance by the orifice 21 can be ensured.

  The concave portion 77 has a bottom portion 78 formed at a position overlapping the stopper portion 59 in projection in a direction perpendicular to the axis orthogonal to the direction of the axis O. As a result, it is possible to make it difficult for stress concentration due to the recess 77 to occur while ensuring the effect that the spring of the elastic wall 71 can be softened by the recess 77. As a result, fatigue of the elastic wall 71 can be suppressed.

  The concave portion 77 is provided on the outer peripheral side from the midpoint of the line segment connecting the axis O passing through the center of the elastic wall 71 (the center of the central hole 71) and the inner peripheral surface 62 of the convex portion 61 of the orifice forming member 51. Therefore, it is difficult to add the displacement in the twisting direction to the axial reciprocation displacement of the partition plates 80 and 90 by the actuator 30. When a displacement in the twisting direction is applied to the partition plates 80 and 90, the fluid pressure control in the first liquid chamber 19 due to the axial vibration of the partition plates 80 and 90 varies, and a high-frequency amplitude of a minute amplitude is input. There is a risk that the vibration damping performance of the will be reduced. According to the active vibration isolator 10, since the concave portion 77 is provided on the outer peripheral side of the elastic wall 71, it is possible to smoothly reciprocate in the direction of the axis O while suppressing displacement in a twisting direction in which the axis is inclined. Vibration damping performance can be secured.

  Even when the operation of the actuator 30 is stopped by a control device (not shown), when a high frequency amplitude having a higher frequency than the frequency band attenuated by the orifice 21 is input, the partition plate 80, By reciprocating 90 integrally, the liquid pressure in the first liquid chamber 19 is absorbed and vibration can be reduced. Therefore, the dynamic spring constant can be reduced with respect to high-frequency fine amplitude vibration. Since the recessed part 77 is formed in the elastic wall 71, the rigidity of the elastic wall 71 can be reduced and the partition plates 80 and 90 can be further reciprocated.

  Next, a second embodiment will be described with reference to FIGS. 1st Embodiment demonstrated the case where the stopper part 59 which protrudes toward the radial inside from the extension part 58 and the convex part 61 of the orifice formation member 51 was provided continuously over the circumferential direction. In contrast, in the second embodiment, a case where the stopper portion 152 is provided intermittently in the circumferential direction of the orifice forming member 151 will be described. In addition, about the part same as 1st Embodiment, the same code | symbol is attached | subjected and the following description is abbreviate | omitted. 5 is a perspective view of an orifice forming member 151 of the active vibration isolator according to the second embodiment, FIG. 6 is a plan view of the partition 150, and FIG. 7 is a partition along the line VII-VII in FIG. FIG. The partition 150 is incorporated in the active vibration isolator 10 instead of the partition 50 described in the first embodiment.

  As shown in FIGS. 5 and 6, the orifice forming member 151 located on the outer peripheral portion of the partition 150 has a stopper portion 152 that protrudes radially inward from the extending portion 58 and the convex portion 61. Is provided. A plurality (four in the present embodiment) of the stopper portions 152 are provided intermittently in the circumferential direction of the extending portion 58. In addition, the orifice forming member 151 has a plurality of (four in the present embodiment) inner edge portions 153 projecting in a radial shape from the extending portion 58 and the convex portion 61 in the radially inward direction between the stopper portions 152. Is provided. The length of the inner edge portion 153 in the radial direction is set to be smaller than the length of the stopper portion 152 in the radial direction.

  As shown in FIG. 7, the stopper portion 152 has partition plates 80 and 90 arranged on both sides in the axial direction, and is set to a size that partially overlaps the partition plates 80 and 90 in the projection in the axial direction. Unlike the stopper portion 152, the inner edge portion 153 is set to a size that is located radially outward of the partition plates 80 and 90. Since the stopper portion 152 is intermittently provided in the circumferential direction, the spring at the base portion of the elastic wall 71 can be softened as compared with the case where the stopper portion 152 is continuously provided in the circumferential direction. Therefore, the partition plates 80 and 90 can be easily reciprocated in the axial direction by the actuator 30.

  Further, since the inner edge portion 153 provided between the stopper portions 152 is located radially outward of the partition plates 80 and 90 in the axial projection, compared to the case where the inner edge portion 153 is not provided, The rigidity of the base portion of the elastic wall 71 can be improved. As a result, it is possible to improve the effect of restricting the displacement of the partition plates 80 and 90 when a large amplitude vibration in a low frequency range is input from the first fixture 11 or the second fixture 12.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. It can be easily guessed. For example, the arrangement, number, and shape of the recesses 77 formed in the elastic wall 71 are not limited to this embodiment, and various changes can be made. Instead of providing the concave portion 77 on the wall surface 76, the concave portion 77 may be formed on the wall surface 75, and the concave portion 77 may be provided on both the wall surfaces 75 and 76. Note that it is not essential to provide the recess 77 in the elastic wall 71.

  In each of the above-described embodiments, the case where the stopper portions 59 and 152 are formed on the orifice forming members 51 and 151 attached to the first fixture 12 has been described. It is naturally possible to provide the stopper portions 59 and 152 projecting toward the inner peripheral surface of the second fixture 12 (tubular fitting 13). In the second embodiment, the case where four stopper portions 159 are provided intermittently in the circumferential direction has been described. However, the present invention is not limited to this, and the number of stopper portions 159 can be set as appropriate.

  In each of the above-described embodiments, the first liquid chamber 19 and the second liquid chamber 20 are formed by the partition 50, and the first liquid chamber 19 and the second liquid chamber 20 are connected by the orifice 21. However, it is not necessarily limited to this. For example, it is naturally possible to connect the first liquid chamber 19 and the second liquid chamber 20 with a plurality of orifices according to the required vibration isolation performance. In addition to the first liquid chamber 19 and the second liquid chamber 20, it is naturally possible to have one or more sub liquid chambers. In this case, two liquid chambers among the first liquid chamber 19, the second liquid chamber 20, and the sub liquid chamber can be communicated with each other by one or more orifices other than the orifice 21.

  In each of the above embodiments, the case where the active vibration isolator 10 is used as an engine mount that elastically supports an automobile engine has been described. However, the present invention is not necessarily limited thereto. It is naturally possible to apply the active vibration isolator 10 to a vibration isolator that suppresses vibration of an arbitrary vibrating body such as a body mount or a differential mount.

  In each of the above embodiments, the active vibration isolator 10 in which the diaphragm 17 is disposed below the vibration isolation base 15 and the second liquid chamber 20 is provided below the first liquid chamber 19 has been described. However, the present invention is not necessarily limited to this, and the anti-vibration base 15 and the diaphragm 17 can be arranged at arbitrary positions. For example, it is naturally possible to dispose a diaphragm above the vibration isolation base 15 and provide the second liquid chamber above the first liquid chamber. In this case, an orifice for connecting the first liquid chamber and the second liquid chamber is formed on the outer periphery of the vibration isolating substrate 15.

  In the above embodiment, the case where the shaft-shaped member 34 is fixed to the partition plate 90 by ultrasonic welding has been described. However, the present invention is not limited to this, and the shaft-shaped member 34 is fixed to the partition plate 90 by screwing or the like. It is of course possible to fix.

  In each of the embodiments described above, a case where an alternating current (such as a sine wave signal or a rectangular wave signal) is supplied to the actuator 30 to excite the coil 42 and the drive shaft 32 elastically supported by the leaf spring 36 is reciprocated is described. However, it is not necessarily limited to this. In the case of an actuator in which the drive shaft is urged to one side in the direction of the axis O by the coil spring, the coil is excited when the coil is intermittently energized and deenergized by intermittently supplying a direct current to the coil. Thus, the coil spring can be compressed to displace the drive shaft, and the drive shaft can be displaced by the restoring force of the coil spring by demagnetizing the coil. Even in an active vibration isolator employing such an actuator, the same actions and effects as in the present embodiment can be realized.

DESCRIPTION OF SYMBOLS 10 Active type vibration isolator 11 1st fixture 12 2nd fixture 15 Anti-vibration base | substrate 17 Diaphragm 19 1st liquid chamber 20 2nd liquid chamber 21 Orifice 30 Actuator 32 Drive shaft 51,151 Orifice formation member 59,152 Stopper part 60 Protruding end 62 Inner peripheral surface 70 Exciting body 71 Elastic wall 76 Wall surface 77 Recessed portion 78 Bottom portion 80, 90 Partition plate 93 Connecting portion 153 Inner edge portion

Claims (4)

A first fixture and a cylindrical second fixture;
An anti-vibration base composed of a rubber-like elastic body connecting the first fixture and the second fixture;
A first liquid chamber in which the vibration-proof substrate constitutes at least a part of a chamber wall;
Excitation that forms part of another chamber wall of the first liquid chamber, is connected to the second fixture side, and is provided at a position facing the vibration isolation base in the axial direction of the second fixture. Body,
An actuator that is disposed on the opposite side of the first liquid chamber across the vibration body in the axial direction of the second fixture, and that vibrates the vibration body in the axial direction by a drive shaft;
A stopper portion provided on the second fixture side and projecting radially inward,
The vibrating body is
An elastic wall made of a rubber-like elastic body and connected to the second fixture side;
A pair of partition plates that are connected to each other via a connecting portion that penetrates the radial center of the elastic wall in the thickness direction and sandwiches the elastic wall from both sides in the axial direction;
The pair of partition plates, said while being arranged on both sides of the stopper portion in the axial direction of the second fixture, Ri Do heavy part and both the stopper portion in the projection in the axial direction,
The active vibration isolator , wherein the stopper portion is provided intermittently in the circumferential direction . An inner edge portion provided on the second fixture side and projecting radially inward from between the stopper portions;
The inner edge is set the radial length is smaller than the length in the radial direction of the stopper portion, according to claim 1, wherein the located radially outward of the partition plate in the projection in the axial direction Active vibration isolator. A first fixture and a cylindrical second fixture;
An anti-vibration base composed of a rubber-like elastic body connecting the first fixture and the second fixture;
A first liquid chamber in which the vibration-proof substrate constitutes at least a part of a chamber wall;
Excitation that forms part of another chamber wall of the first liquid chamber, is connected to the second fixture side, and is provided at a position facing the vibration isolation base in the axial direction of the second fixture. Body,
An actuator that is disposed on the opposite side of the first liquid chamber across the vibration body in the axial direction of the second fixture, and that vibrates the vibration body in the axial direction by a drive shaft;
A stopper portion provided on the second fixture side and projecting radially inward,
The vibrating body is
An elastic wall made of a rubber-like elastic body and connected to the second fixture side;
A pair of partition plates that are connected to each other via a connecting portion that penetrates the radial center of the elastic wall in the thickness direction and sandwiches the elastic wall from both sides in the axial direction;
The pair of partition plates, said while being arranged on both sides of the stopper portion in the axial direction of the second fixture, Ri Do heavy part and both the stopper portion in the projection in the axial direction,
The elastic wall is a portion located radially inward from the protruding end of the stopper portion, and a concave portion is provided on a wall surface facing the partition plate,
The active type vibration isolator , wherein the concave portion has a bottom portion at a position overlapping the stopper portion when projected in a direction perpendicular to the axis . A diaphragm that is configured of a rubber-like elastic body connected to the second fixture side, and that is disposed on the opposite side of the first liquid chamber with the vibration body interposed therebetween in the axial direction of the second fixture; ,
A second liquid chamber in which the diaphragm and the vibrating body constitute at least a part of a chamber wall;
An annular orifice forming member that is disposed inside the second fixture and that forms an orifice that communicates the second liquid chamber and the first liquid chamber;
The stopper portion protrudes radially inward from the inner peripheral surface of the orifice forming member,
The active vibration isolator according to any one of claims 1 to 3, wherein the elastic wall is connected to an inner peripheral surface of the orifice forming member.

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