JP2007120597A - Vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the structure and assembly work of a device respectively. <P>SOLUTION: In a vibration isolator 10, magnets 128 and 130 apply magnetic repulsion force for a plunger member 78. The magnetic repulsion force urges the plunger member 78 to an opening position side. When a shake vibration is input, the plunger member 78 moves to a blocking position against the magnetic repulsion force of the magnets 128 and 130 with liquid pressure in a pressurized space 112 to blocks an orifice opening 76. When an idle vibration is input, the plunger member 78 moves to an opening position with the magnetic repulsion force of the magnets 128 and 130 to open the orifice opening 76. Thereby, in order to restore the plunger member 78 in a blocked position to restore to the opening position, a seat receiving part etc., to retain an urging member of a coil spring etc. can be dispensed with. The work to install the urging member to the device inside of a cylinder chamber 60 etc. also can be dispensed with. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fluid-filled vibration isolator that prevents transmission of vibration from a member that generates vibration, and more particularly, to a vibration isolator that is suitably used for an engine mount of an automobile.

  For example, in a vehicle such as a passenger car, a vibration isolator as an engine mount is disposed between an engine serving as a vibration generating unit and a vehicle body serving as a vibration receiving unit, and the vibration isolating device generates vibration generated from the engine. It is structured to absorb and prevent transmission to the vehicle body side. This type of vibration isolator is provided with a main liquid chamber and a sub liquid chamber, and a plurality of orifices communicating with each of these liquid chambers in order to cope with vibrations in a wide range of frequencies. Among the plurality of orifices, one that selectively opens and closes the plurality of orifices by a valve mechanism driven by an electromagnetic solenoid or the like so that the main liquid chamber and the sub liquid chamber communicate with each other by one orifice is known. ing.

  In other words, this vibration isolator requires not only an electric electromagnetic solenoid for controlling the opening / closing state of the orifice and switching the liquid passage between the plurality of orifices, but also the electromagnetic solenoid etc. A controller that operates based on the frequency or the like and switches the orifice is structurally necessary. However, these electromagnetic solenoids and controllers are relatively expensive, and these components significantly complicate the structure of the vibration isolator and make the installation work on the vehicle complicated. It was.

In view of the above problems, the inventors of the present application disclosed in Patent Document 1 that the main liquid chamber and the sub liquid chamber are communicated with each other by a shake orifice and an idle orifice, and form a part of the idle orifice. The plunger member arranged in the cylinder space communicating with the sub liquid chamber moves to the closed position where the idle orifice is closed by the hydraulic pressure of the main liquid chamber when the shake vibration is input, and the plunger member is moved to the coil spring when the idle vibration is input. An anti-vibration device is disclosed in which the idle orifice is moved to an open position where the idle orifice is opened.
International Publication WO 2004/081408

  However, in the vibration isolator described in Patent Document 1, it is necessary to arrange the coil spring in a compressed state as a biasing member that biases the plunger member to the open position inside the cylinder chamber. For this reason, in the vibration isolator as in Patent Document 1, it is necessary to provide a seat receiving portion that engages with the coiled portion of the coil spring on the inner wall portion on the side of the secondary liquid chamber and the plunger member in the cylinder chamber.

  Therefore, in the vibration isolator as in Patent Document 1, a coil spring is required, and since it is necessary to provide seat receiving portions on the inner wall portion and the plunger member on the side of the secondary liquid chamber, the shape of the component parts of the device is It becomes complicated. Also, when assembling the device, a plunger member is inserted into the cylinder chamber, a coil spring is interposed between the inner wall of the cylinder chamber and the plunger member, and the end surface (opening end) on the main liquid chamber side of the cylinder chamber is the lid member. The coil spring must be held in a compressed state between the pair of seat receiving parts until it is closed by, for example, the problem that the assembly work (assembly work) of the apparatus becomes complicated.

  An object of the present invention is to provide a vibration isolator capable of simplifying the structure and assembly work of the apparatus in consideration of the above facts.

  In order to achieve the above object, a vibration isolator according to claim 1 of the present invention includes a first attachment member connected to one of the vibration generating portion and the vibration receiving portion, and the other of the vibration generating portion and the vibration receiving portion. A second mounting member coupled to the first mounting member, an elastic body disposed between the first mounting member and the second mounting member, and a liquid sealed with the elastic body as a part of a partition, A main liquid chamber whose internal volume changes with elastic deformation of the elastic body, a secondary liquid chamber in which liquid is enclosed and whose internal volume can be expanded and contracted, and a main liquid chamber and a secondary liquid chamber that communicate with each other. The first restriction passage, the main liquid chamber and the sub liquid chamber communicate with each other, the second restriction passage having a smaller flow resistance of the liquid than the first restriction passage, the main liquid chamber and the sub liquid. A part of the second restriction passage between the cylinder chamber provided between the chamber and the liquid chamber and the cylinder chamber The orifice space is configured to be divided into an orifice space that communicates with the sub liquid chamber and a hydraulic pressure space that is isolated from the second restriction passage, and a predetermined opening position is provided along the expansion and contraction directions of the orifice space and the hydraulic pressure space. A plunger member that is movable between the closed position and an orifice opening that faces the orifice space and communicates the orifice space and the other portion of the second restriction passage; A check valve that is arranged between the liquid chamber and the hydraulic pressure space, and that allows liquid to flow out only in one direction between the main liquid chamber and the hydraulic pressure space as the hydraulic pressure changes in the main hydraulic chamber. And magnetic urging means for applying a magnetic force to the plunger member and urging the plunger member toward the open position by the magnetic force, and the plunger member is a liquid in the hydraulic space. Pressure The orifice opening is closed when moved to the closed position against the magnetic force of the urging means, and the orifice opening is opened when moved to the open position by the magnetic force of the magnetic urging means. .

  The operation of the vibration isolator according to claim 1 of the present invention will be described below.

  In the vibration isolator of claim 1, basically, when vibration is transmitted to one of the first and second mounting members, the elastic body arranged between the first and second mounting members is elastic. The vibration is absorbed by the vibration absorbing action based on the internal friction or the like of the elastic body, and the vibration transmitted to the vibration receiving portion side is reduced.

  In the vibration isolator according to the first aspect, the main liquid chamber and the sub liquid chamber communicate with each other through the first restriction passage, and the main liquid chamber and the sub liquid chamber are in the first state when the orifice opening is open. The two restriction passages having a liquid flow resistance smaller than that of the first restriction passage communicate with each other. Furthermore, in the vibration isolator according to claim 1, when the plunger member located at the open position moves to the closed position by the hydraulic pressure supplied from the main fluid chamber into the hydraulic pressure space through the check valve, the elasticity of the elastic body is increased. Along with the deformation, the liquid moves back and forth between the main liquid chamber and the sub liquid chamber only through the first restriction passage, and the plunger member in the closed position is moved to the open position by the magnetic force of the magnetic biasing means. Upon return, both the first restriction passage and the second restriction passage are opened, but the second restriction passage having a relatively small liquid flow resistance is given priority with the elastic deformation of the elastic body. The liquid flows back and forth between the main liquid chamber and the sub liquid chamber.

  That is, in the vibration isolator according to claim 1, when vibration with relatively low frequency and large amplitude (hereinafter referred to as “low frequency vibration”) is input, the elastic body is caused by the low frequency vibration. Due to elastic deformation, a relatively large fluid pressure change occurs in the main fluid chamber, and when the fluid pressure periodically changes in the main fluid chamber, the liquid flows from the main fluid chamber into the fluid pressure space through the check valve, or the fluid pressure The liquid flows out from the space into the main liquid chamber, and reaches an equilibrium pressure at which the liquid pressure in the hydraulic pressure space substantially equilibrates with the liquid pressure (maximum value or minimum value) in the main liquid chamber. At this time, if the magnitude of the magnetic force that the magnetic biasing means acts on the plunger member as the biasing force is set to be smaller than the value corresponding to the equilibrium pressure in the hydraulic pressure space, the plunger member will have the magnetic force of the magnetic biasing means. Against this, it moves intermittently from the open position to the closed position side and is held at the closed position by the hydraulic pressure in the hydraulic pressure space.

  Therefore, if the flow resistance of the liquid in the first restricting passage is set (tuned) so as to correspond to the frequency and amplitude of the low-frequency vibration, the main liquid chamber and the sub liquid chamber pass through the first restricting passage. Since a resonance phenomenon (liquid column resonance) occurs in the liquid flowing back and forth, the low frequency range vibration can be absorbed particularly effectively by the action of the liquid column resonance.

  In the vibration isolator according to claim 1, when vibration with relatively high frequency and small amplitude (hereinafter referred to as “high frequency range vibration”) is input, the elastic body is elastically deformed by the high frequency range vibration. At the same time, since a relatively small change in hydraulic pressure occurs in the main liquid chamber, in this case as well, liquid flows from the main liquid chamber into the hydraulic pressure space through the check valve when the hydraulic pressure changes periodically in the main liquid chamber. Alternatively, the liquid flows out from the hydraulic pressure space to the main liquid chamber, and reaches an equilibrium pressure at which the hydraulic pressure in the hydraulic pressure space substantially equilibrates with the hydraulic pressure (maximum value or minimum value) in the main liquid chamber. At this time, if the magnitude of the magnetic force that the magnetic biasing means acts on the plunger member as the biasing force is set larger than the value corresponding to the equilibrium pressure in the hydraulic pressure space, when the plunger member is in the open position, When the magnetic urging means is held in the open position by the urging force, and when it is in the closed position, the magnetic urging means moves (returns) from the closed position to the open position.

  Therefore, in the vibration isolator according to the first aspect, when the high frequency vibration is input, the second restricting passage having a smaller liquid flow resistance than the first restricting passage is given priority with the elastic deformation of the elastic body. Since the liquid goes back and forth between the main liquid chamber and the sub liquid chamber, it is possible to effectively reduce high-frequency vibrations transmitted from the vibration generating unit to the vibration receiving unit.

  At this time, if the flow resistance of the liquid in the second restriction passage is set (tuned) so as to correspond to the frequency and amplitude of the high-frequency vibration, the main liquid chamber and the sub liquid chamber pass through the second restriction passage. Since a resonance phenomenon (liquid column resonance) occurs in the liquid flowing back and forth, the high frequency region vibration can be particularly effectively absorbed by the action of the liquid column resonance.

  As a result, according to the vibration isolator according to claim 1, it is possible to respond to a change in the frequency of the input vibration without using a valve mechanism that operates in response to external control and power supply such as an electromagnetic solenoid or a pneumatic solenoid. The restriction passage communicating the main liquid chamber and the sub liquid chamber can be switched to one of the first restriction passage and the second restriction passage using the change in the liquid pressure in the main liquid chamber as a driving force.

  In the vibration isolator according to claim 1, the magnetic urging means applies a magnetic force to the plunger member, and the magnetic force urges the plunger member to the open position side. At the time of input, the fluid pressure in the hydraulic pressure space moves to the closed position against the magnetic force of the magnetic biasing means to close the orifice opening, and at the time of inputting high frequency vibration, the magnetic biasing means moves to the open position by the magnetic force. A seat receiving part for holding a biasing member such as a coil spring in a predetermined posture in the apparatus is required to return the plunger member in the closed position to the open position by moving and opening the orifice opening. In addition, since the work of assembling the urging member inside the device such as the cylinder chamber can be made unnecessary, a coil spring or the like is used to return the plunger member to the open position. Compared to the anti-vibration device, simplifies the shape and structure of components of the apparatus, further assembly of the device (assembly work) is also simplified.

  The vibration isolator according to claim 2 of the present invention is the vibration isolator according to claim 1, wherein the magnetic urging means causes the magnetic force to act on the plunger member as a repulsive force. It is characterized by urging to the open position side.

  The vibration isolator according to claim 3 of the present invention is the vibration isolator according to claim 1, wherein the magnetic urging means causes the plunger member to act as an attractive force with respect to the plunger member. It is characterized by urging to the open position side.

  The vibration isolator according to claim 4 of the present invention is the vibration isolator according to claim 3, wherein the magnetic urging means is a partition wall section that divides the plunger member, the cylinder chamber, and the sub liquid chamber. A magnet member disposed on one side; and an attracted portion formed of a ferromagnetic material provided in at least a region of the other of the plunger member and the partition wall facing the magnet member. .

  The vibration isolator according to claim 5 of the present invention is the vibration isolator according to claim 4, wherein the magnetic biasing means is configured such that the magnet member and the attracted member are in a state where the plunger member is in the open position. A gap having a predetermined width is formed along the expansion / contraction direction with respect to a portion, and a maximum attraction force generated between the magnet member and the attracted portion is adjusted by the agitation.

  The vibration isolator according to claim 6 of the present invention is the vibration isolator according to any one of claims 1 to 3, wherein the magnetic biasing means is a first magnet member disposed on the plunger member. And a second magnet member disposed in a partition wall partitioning the cylinder chamber and the auxiliary liquid chamber so as to face the first magnet member along the expansion / contraction direction. And

  As described above, according to the vibration isolator of the present invention, the structure of the device and the assembly work can be simplified.

  Hereinafter, a vibration isolator according to an embodiment of the present invention will be described with reference to the drawings. In the figure, symbol S represents the axial center of the apparatus, and the following description will be made with the direction along the axial center S as the axial direction of the apparatus.

(First embodiment)
1 and 2 show a vibration isolator according to a first embodiment of the present invention. The vibration isolator 10 is provided with a cylindrical upper outer cylinder 12 on the outer peripheral upper end side, and a cylindrical lower outer cylinder 14 is connected and fixed to the lower side of the upper outer cylinder 12. The upper outer cylinder 12 is formed with a bent flange portion 16 at the lower end thereof that extends outward. The lower outer cylinder 14 is formed with an annular step portion 18 extending in the circumferential direction at an axially intermediate portion, and a large-diameter cylindrical portion 20 and a small-diameter portion on the upper side and the lower side through the step portion 18, respectively. A cylindrical portion 22 is provided. Further, the lower outer cylinder 14 is formed with a bent flange portion 24 at its upper end portion extending outward, and the flange portion 16 of the upper outer cylinder 12 is placed on the flange portion 24. Yes. In the vibration isolator 10, the upper outer cylinder 12 and the lower outer cylinder 14 are caulked and fixed to each other by bending the outer peripheral side of the flange portion 16 toward the inner peripheral side so as to sandwich the outer peripheral side of the flange portion 24. The anti-vibration device 10 is connected and fixed to the engine side of the vehicle through the holder metal fitting when the lower outer cylinder 14 is inserted into a cup-shaped holder metal fitting (not shown).

  An outer peripheral portion of a rubber elastic body 26 formed in a substantially cylindrical shape is vulcanized and bonded to the inner peripheral surface of the small-diameter cylindrical portion 22 on the lower outer cylinder 14, and at the inner peripheral surface of the large-diameter cylindrical portion 20. A thin cylindrical covering portion 28 extending upward from the outer peripheral portion of the rubber elastic body 26 is vulcanized and bonded. The rubber elastic body 26 is formed in a substantially C shape whose cross-sectional shape is inclined upward from the outer peripheral side toward the inner peripheral side. In the vibration isolator 10, a cylindrical mounting bracket 30 is disposed on the inner peripheral side of the lower outer cylinder 14, and the inner peripheral surface of the rubber elastic body 26 is vulcanized and bonded to the outer peripheral surface of the mounting bracket 30. Has been. The rubber elastic body 26 is integrally formed with a ring-shaped cushion portion 29 that extends from the upper end portion on the inner peripheral side to the inner peripheral side, and this cushion portion 29 is vulcanized on the top surface portion of the mounting bracket 30. It is glued. A screw hole 32 is drilled along the axis S from the lower end surface of the mounting bracket 30. In the vibration isolator 10, the mounting bracket 30 is connected and fixed to the vehicle body side via bolts (not shown) screwed into the screw holes 32.

  In the vibration isolator 10, a partition metal fitting 34, which is formed in a substantially thick disk shape as a whole, is fitted on the inner peripheral side of the outer cylinders 12,14. The partition bracket 34 divides the space on the inner peripheral side of the upper outer cylinders 12 and 14 into two small spaces along the axial direction, and each of the two small spaces is filled with a liquid such as water or ethylene glycol. The main liquid chamber 36 and the sub liquid chamber 38 are enclosed. Here, the main liquid chamber 36 has the rubber elastic body 26 as a part of the partition wall, and its internal volume changes (expands / contracts) with the elastic deformation of the rubber elastic body 26. The sub-liquid chamber 38 has a diaphragm 40 described later as a part of the partition wall, and the inner volume can be expanded and contracted by the deformation of the diaphragm 40.

  As shown in FIG. 1, a rubber covering portion 42 formed in a thin film shape is vulcanized and bonded to the inner peripheral surface and the outer peripheral surface of the upper outer cylinder 12, and the upper end portion of the covering portion 42. The peripheral part of the rubber diaphragm 40 formed in a bowl shape opened downward is joined over the entire circumference. The diaphragm 40 closes the upper end side of the upper outer cylinder 12 and can be deformed so as to expand and contract the sub liquid chamber 38 with a sufficiently small load (hydraulic pressure).

  As shown in FIG. 5, the partition metal fitting 34 is provided with a substantially thick cylindrical upper orifice member 44 formed of a metal material such as a resin material or aluminum on the upper end side thereof, and the upper orifice member 44. A disc-like lower orifice member 46 made of a metal material such as aluminum is disposed on the lower side. The upper orifice member 44 is formed in a bottomed cylindrical shape whose upper end side is closed by a top plate portion 45, and the top plate portion 45 is formed in a substantially fan shape whose opening width increases from the inner peripheral side toward the outer peripheral side. A plurality of (four in this embodiment) flow openings 48 are formed, and a circular fitting hole 88 is formed in the center of these flow openings 48. Further, the upper orifice member 44 is integrally formed with an annular flange portion 52 that extends to the outer peripheral side at an axially intermediate portion on the outer peripheral surface thereof.

  As shown in FIG. 3, the top plate portion 45 of the upper orifice member 44 is integrally formed with a thick disc-shaped boss portion 132 on the inner peripheral side of the flow opening 48. The lower end side protrudes downward with respect to the lower surface of the top plate portion 45. The boss portion 132 has a circular insertion hole 133 passing through in the axial direction at the center thereof. A fixed-side magnet 128 formed in a thick disc shape is inserted into the insertion hole 133, and the outer surface of the fixed-side magnet 128 is an inner periphery of the insertion hole 133 with an adhesive or the like. It is fixed to the surface. Here, the fixed-side magnet 128 has a magnetic pole surface 128N having an N pole at the upper end surface along the axial direction, and a magnetic pole surface 128S having an S pole at the lower end surface in the insertion hole 133. Has been placed. The fixed magnet 128 is positioned so that its central axis substantially coincides with the axis S.

  The lower orifice member 46 is formed with an insertion insertion portion 50 formed in a circular convex shape protruding upward at the center thereof, and an annular portion corresponding to the flange portion 52 of the upper orifice member 44 on the outer peripheral portion. A flange portion 55 is formed. Further, the lower orifice member 46 is formed with a hook-like portion 56 extending in the circumferential direction between the fitting insertion portion 50 and the flange portion 55 along the radial direction. The hook-like portion 56 has a substantially U shape (see FIG. 3) whose cross section is open upward, and the bottom plate portion has a substantially rectangular lower portion at a predetermined portion along the circumferential direction. A communication hole 58 is formed.

  As shown in FIG. 1, in the partition fitting 34, the insertion portion 50 of the lower orifice member 46 is inserted into the inner peripheral side of the upper orifice member 44 from below, and the flange portion 55 of the lower orifice member 46 is connected to the upper orifice. The flange portion 52 of the member 44 is brought into contact with the flange portion 52, and the flange portions 52 and 55 are sandwiched between the flange portion 16 of the upper outer cylinder 12 and the flange portion 24 of the lower outer cylinder 14. Thereby, the upper orifice member 44 and the lower orifice member 46 are fixed and integrated with each other, and the partition metal fitting 34 is fixed to the upper outer cylinder 12 and the lower outer cylinder 14.

  As shown in FIG. 3, the lower orifice side of the upper orifice member 44 is closed by the inner peripheral side of the flange portion 55 of the lower orifice member 46, so that the upper orifice member 44 has a cylindrical shape partitioned from the outside. A cylinder chamber 60 is formed. The same liquid as the main liquid chamber 36 and the sub liquid chamber 38 is also sealed in the cylinder chamber 60. The upper orifice member 44 is formed with a lower end groove portion 62 extending in the circumferential direction by cutting the lower end portion of the outer peripheral surface into an L shape. The lower end groove portion 62 is formed in a C shape that circulates the outer peripheral surface of the upper orifice member 44 over almost one round, and both end portions along the circumferential direction are closed by the lower end portion of the upper orifice member 44. Yes.

  In the partition member 34, when the lower orifice member 46 is fixed to the lower end side of the upper orifice member 44, the lower end portion of the upper orifice member 44 is fitted and inserted into the flanged portion 56 of the lower orifice member 46, and the upper orifice member The outer peripheral side and the bottom side of the lower end groove portion 62 of the 44 are respectively closed by the inner wall of the bowl-shaped portion 56. As a result, a lower orifice passage 64 is formed in the lower end groove portion 62 of the upper orifice member 44, which is an end-shaped space that is elongated from the outside in the circumferential direction. One end of the lower orifice passage 64 communicates with the main liquid chamber 36 through the lower communication hole 58.

  As shown in FIG. 5, the upper orifice member 44 is formed with an outer peripheral groove 66 extending spirally around the axis S on the outer peripheral surface thereof. The outer circumferential groove 66 circulates the outer circumferential surface of the upper orifice member 44 over two or more rounds. The circumferential groove 66 is closed at both ends in the circumferential direction by the inner wall portion of the upper orifice member 44. The outer circumferential groove 66 is provided with a dedicated orifice portion 68 having a relatively narrow width along the axial direction in a portion from one end portion on the side of the secondary liquid chamber 38 to the middle portion in the circumferential direction. A common orifice portion 70 having a relatively wide width along the axial direction and a path length shorter than that of the dedicated orifice portion 68 is provided in a portion from the terminal portion to the other end portion on the main liquid chamber 36 side.

  The upper orifice member 44 is formed with an upper communication hole 72 penetrating between one end portion of the outer circumferential groove 66 (dedicated orifice portion 68) and the upper surface portion of the upper orifice member 44, and the outer circumferential groove 66 (common orifice portion). 70) is provided with an intermediate connection hole 74 for connecting the other end of the rod 70) to the other end of the bowl-shaped portion 56. The upper orifice member 44 penetrates between the bottom surface portion on the inner peripheral side of the outer peripheral groove 66 and the inner peripheral surface of the cylinder chamber 60 in the vicinity of the boundary between the dedicated orifice portion 68 and the common orifice portion 70 in the outer peripheral groove 66. An orifice opening 76 is formed. The orifice opening 76 is formed in a slot shape elongated in the circumferential direction.

  As shown in FIG. 1, in the vibration isolator 10, the outer peripheral surface of the upper orifice member 44 is located on the upper side through the covering portion 42 in a state where the partition fitting 34 is fitted and inserted into the inner peripheral side of the outer cylinders 12 and 14. The outer cylinder 12 is pressed against the inner peripheral surface. Thereby, the outer peripheral side of the outer peripheral groove 66 (the dedicated orifice portion 68 and the common orifice portion 70) of the upper orifice member 44 is blocked by the inner peripheral surface of the covering portion 42. At this time, the spaces in the lower orifice passage 64 and the outer peripheral groove 66 (the common orifice portion 70 and the dedicated orifice portion 68) are connected to each other through the intermediate connection hole 74 to form a shake orifice 118 which is one elongated space. One end of the shake orifice 118 serving as the first restriction passage is connected to the auxiliary liquid chamber 38 through the upper communication hole 72 of the upper orifice member 44 and the other end is connected to the lower communication hole 58 of the lower orifice member 46. Through the main liquid chamber 36.

  Here, the shake orifice 118 has a path length and a cross-sectional area, that is, a flow resistance of liquid so as to correspond to a shake vibration (for example, 9 to 15 Hz) which is a relatively low frequency vibration of the input vibration. It is set (tuned).

  As shown in FIG. 3, a plunger member 78 formed in a substantially disc shape (see FIG. 5) is accommodated in the cylinder chamber 60 of the upper orifice member 44 so as to be movable along the axial direction. The plunger member 78 divides the cylinder chamber 60 along the axial direction into a hydraulic space 112 which is a small space on the main liquid chamber 36 side and an orifice space 114 (see FIG. 4) which is a small space on the sub liquid chamber 38 side. is doing. The plunger member 78 has an upper end side and a lower end side edge portion of the outer peripheral surface thereof extending in parallel with the longitudinal direction of the orifice opening 76.

  As shown in FIG. 5, the plunger member 78 is formed in a bottomed cylindrical shape whose top surface side is closed by a top plate portion 80 as a whole, and a hollow portion 81 that opens downward on the inner peripheral side thereof. In addition to being formed, a boss part 134 having a disc shape thicker than the outer peripheral side is integrally formed at the center part of the top plate part 80. The plunger member 78 is formed with a hydraulic pressure release passage 126 penetrating in the axial direction on the outer peripheral side of the boss 134.

  As shown in FIG. 3, the upper end side of the boss part 134 projects from the upper surface of the top plate part 80 into the hydraulic pressure space 112. The boss portion 134 has a circular insertion hole 135 penetrating in the axial direction at the center thereof. A movable side magnet 130 formed in the shape of a thick disc is inserted into the insertion hole 135, and the outer peripheral surface of the movable side magnet 130 is bonded to the inner periphery of the insertion hole 135 by an adhesive or the like. It is fixed to the surface. Here, the movable-side magnet 130 has a magnetic pole surface 130S whose upper end surface along the axial direction is an S pole, and a magnetic pole surface 130N whose lower end surface is an N pole. Is arranged. The movable magnet 130 is positioned so that its central axis substantially coincides with the axis S, and the outer diameter thereof is substantially equal to the outer diameter of the fixed magnet 128.

  As shown in FIG. 3, the plunger member 78 is inserted into the cylinder chamber 60 of the upper orifice member 44, and has a predetermined range along the inner circumferential surface of the cylinder chamber 60 (an open position and a later-described position). Between the closed position). Further, the fitting portion 50 of the lower orifice member 46 is formed with a small-diameter portion 84 whose outer diameter is smaller than that of the lower end side on the top plate portion 82 side. The top plate portion 82 is formed with a circular concave holder portion 86 on the center side thereof. The holder portion 86 is formed to be curved so that the outer peripheral portion of the top plate portion 82 has a semicircular cross section over the entire circumference. As shown in FIG. 5, the top plate portion 82 is provided with a circular fitting insertion hole 88 at the center thereof, and a plurality of circular valve seat openings 90 are formed on the outer peripheral side of the fitting insertion hole 88. (4 in this embodiment) are formed.

  As shown in FIG. 3, the partition member 34 is provided with a holder member 92 that is inserted into the outer peripheral side of the insertion portion 50 in the lower orifice member 46. The holder member 92 is formed in a bottomed cylindrical shape whose top surface is closed by a top plate portion 94, and a cylindrical large diameter portion 96 is provided on the lower end side along the amplitude direction. A small-diameter portion 98 whose inner and outer diameters are reduced is integrally formed on the upper side. Here, the outer diameter of the small diameter portion 98 is shorter than the inner diameter of the cylinder chamber 60 by a predetermined length. The large-diameter portion 96 has an annular flange portion 100 that is bent and formed at the lower end thereof. The top plate portion 94 of the holder member 92 is provided with a circular insertion hole 102 at the center thereof, and the opening width increases from the inner periphery side toward the outer periphery side on the outer periphery side of the insertion insertion hole 102. In addition, a plurality of substantially fan-shaped communication openings 95 (four in this embodiment) are formed.

  The holder member 92 closes the top surface side of the holder portion 86 of the lower orifice member 46 by the top plate portion 94, and places the small diameter portion 98 and the large diameter portion 96 on the outer peripheral side on the upper end side and the lower end side of the fitting insertion portion 50. Each is inserted. The holder member 92 has a flange portion 100 sandwiched between the lower end surface of the upper orifice member 44 and the bottom surface portion of the flange portion 56 of the lower orifice member 46. Thereby, the holder member 92 is fixed to the upper orifice member 44 and the lower orifice member 46 in the cylinder chamber 60. Further, a cylindrical gap is formed between the outer peripheral surface of the small diameter portion 98 of the holder member 92 and the inner peripheral surface of the cylinder chamber 60 so that the peripheral wall portion of the plunger member 78 can be inserted and removed along the axial direction. .

  As shown in FIG. 3, the holder portion 86 of the lower orifice member 46 is closed by a top plate portion 94 of the holder member 92 on the top surface side thereof, thereby forming a disk-shaped space partitioned from the outside. A certain valve body storage chamber 104 is formed. As shown in FIG. 3, the valve body storage chamber 104 houses a valve body 106 formed in a substantially disk shape from a rubber material such as NR or NBR.

  The valve body 106 is formed in a slope shape in which the lower surface side is flat and the upper surface side is slightly inclined upward from the inner peripheral side to the outer peripheral side, and the thickness along the axial direction is the inner peripheral surface. It gradually becomes thinner from the side toward the outer periphery. Further, the valve body 106 is formed with a circular convex protrusion 108 at the center of the upper surface and a circular convex protrusion 110 at the center of the lower surface. The valve body 106 has the projection 108 on the upper surface side inserted into the insertion hole 102 of the holder member 92 and the projection 110 on the lower surface side inserted into the insertion hole 88 of the lower orifice member 46. . Thereby, the valve body 106 is positioned coaxially with the holder member 92 and the lower orifice member 46, and is restrained from moving in the radial direction.

  The valve body 106 is compressed along the axial direction between the top plate portion 94 of the holder member 92 and the top plate portion 82 of the lower orifice member 46 in the vicinity of the peripheral portions of the protrusions 108 and 110. As a result, the lower surface portion of the valve body 106 is brought into pressure contact with the top plate portion 82 of the lower orifice member 46 with a predetermined pressure (pre-pressure), and between the holder member 92 and the lower orifice member 46 in the axial direction. Movement is restrained. As indicated by a two-dot chain line in FIG. 3, the valve body 106 is configured such that a portion on the outer peripheral side of the compressed portion is bent upward and deformed.

  As shown in FIG. 3, the valve body 106 has its outer peripheral end positioned radially outside the outer peripheral end of the valve seat opening 90 in the lower orifice member 46 along the radial direction, and the communication opening 95 of the holder member 92. It is located in the inner peripheral side rather than the outer peripheral end. As a result, the valve body 106 closes the valve seat opening 90 in a state where the lower surface portion thereof is pressed against the top plate portion 82 (closed state), and the outer peripheral side is downward as shown by a two-dot chain line in FIG. The valve seat opening 90 is in communication with the communication opening 95 via the valve body storage chamber 104 and the main liquid chamber 36 is in the valve body storage chamber. Communicating into the hydraulic space 112 of the cylinder chamber 60 through 104. That is, the valve body 106, the holder member 92, and the lower orifice member 46 housed in the valve body housing chamber 104 constitute a check valve 116 (see FIG. 5) between the main liquid chamber 36 and the cylinder chamber 60. The check valve 116 allows the liquid to flow only from the main liquid chamber 36 into the cylinder chamber 60 (hydraulic pressure space 112), but the liquid flows out from the hydraulic pressure space 112 into the main liquid chamber 36. To prevent.

  As shown in FIG. 1, the orifice space 114 of the cylinder chamber 60 always communicates with the secondary liquid chamber 38 through the plurality of flow openings 48 of the upper orifice member 44. Further, in the vibration isolator 10, the lower orifice passage 64, the common orifice portion 70, and the orifice space 114 communicating with the common orifice portion 70 through the orifice opening 76 are idles that are vibrations in a high frequency range relative to the shake vibration. An idle orifice 120 corresponding to vibration (for example, 18 to 30 Hz) is formed. The idle orifice 120, which is the second restriction passage, is set (tuned) so that its path length and cross-sectional area, that is, the flow resistance of the liquid corresponds to idle vibration. Here, the flow resistance of the liquid in the idle orifice 120 is smaller than the flow resistance of the liquid in the shake orifice 118. The opening area of the orifice opening 76 is larger than the cross-sectional areas of the common orifice portion 70 and the lower orifice passage 64.

  In the vibration isolator 10, the fixed side magnet 128 is disposed on the top plate portion 45 of the upper orifice member 44, and the movable side magnet 130 is disposed on the top plate portion 80 of the plunger member 78, and these magnets 128, 130 are arranged in the axial direction. The magnetic pole faces 128S and 130S are opposed to each other along the line. As a result, the magnets 128 and 130 generate a magnetic repulsive force along the axial direction. The magnetic repulsive force is in an open position with respect to the plunger member 78 (see FIG. 1). Acts as a biasing force to move to the side. In the case of this embodiment, even if the magnetic pole surfaces 130S of the magnets 128 and 130 are opposed to each other, a magnetic repulsive attractive force that biases the plunger member 78 toward the open position can be generated.

  In the vibration isolator 10, as shown in FIG. 2, when the plunger member 78 moves (rises) to the closed position against the magnetic repulsive force of the magnets 128 and 130, the orifice opening 76 of the upper orifice member 44 is opened. The common orifice part 70 is closed with the orifice space 114 by being blocked by the outer peripheral surface of the plunger member 78. As a result, the main liquid chamber 36 and the sub liquid chamber 38 communicate with each other only through the shake orifice 118.

At this time, as shown in FIG. 4, the outer peripheral surface of the plunger member 78 overlaps the upper and lower regions with respect to the orifice opening 76 on the inner peripheral surface of the cylinder chamber 60. At this time, the overlap amount between the outer peripheral surface of the plunger member 78 and the inner peripheral surface of the cylinder chamber 60 is set to OL _U and OL _A , respectively. The overlap amounts OL _U and OL _A are, for example, It is set to about 2.5 to 3.0 mm.

  In the state where the plunger member 78 is in the closed position as described above, the main liquid chamber is overlapped with the outer peripheral surface of the plunger member 78 and the inner peripheral surface of the cylinder chamber 60 along the axial direction, as will be described later. Even if the plunger member 78 vibrates along the axial direction in accordance with the change in the hydraulic pressure in the inner fluid 36, the orifice opening 76 can be reliably maintained in the closed state by the plunger member 78.

  In the vibration isolator 10, as shown in FIG. 1, when the plunger member 78 moves (lowers) to the open position by the magnetic repulsive force of the magnets 128, 130, the plunger member 78 moves away from the orifice opening 76. The opening 76 is opened, and the common orifice portion 70 communicates with the inside of the lower orifice passage 64. At this time, the plunger member 78 is inserted into the gap formed between the outer peripheral surface of the holder member 92 and the cylinder chamber 60 at the peripheral wall portion. Thereby, the movable range (stroke) required for the plunger member 78 in the cylinder chamber 60 is ensured, and the dimension along the axial direction of the cylinder chamber 60 is made small.

  When the plunger member 78 moves to the open position, the main liquid chamber 36 and the sub liquid chamber 38 communicate with each other through both the shake orifice 118 and the idle orifice 120, but the liquid pressure in the main liquid chamber 36 has changed. In this case, when the liquid flowing into the common orifice part 70 through the lower orifice passage 64 and the intermediate connection hole 74 reaches the vicinity of the boundary with the dedicated orifice part 68, the flow resistance of the liquid is smaller than that of the dedicated orifice part 68. The common orifice portion that preferentially flows into the orifice space 114 through the orifice opening 76 and also flows into the common orifice portion 70 through the orifice opening 76 has a smaller liquid flow resistance than the dedicated orifice portion 68. 70 and the lower orifice passage 64 are preferentially passed into the main liquid chamber 36. Thereby, in the vibration isolator 10, when the plunger member 78 is in the open position, the liquid flows between the main liquid chamber 36 and the sub liquid chamber 38 through substantially only the idle orifice 120.

  Further, the hydraulic pressure release path 126 of the plunger member 78 allows the liquid in the hydraulic space 112 closed from the outside to be orificed when the plunger member 78 moves to the open position side by the magnetic repulsive force of the magnets 128 and 130. The plunger member 78 is allowed to move to the open position side by allowing the plunger member 78 to flow out into the space 114 and preventing the fluid pressure in the fluid pressure space 112 from increasing.

  Next, the operation of the vibration isolator 10 according to the first embodiment of the present invention will be described.

  In the vibration isolator 10, for example, when an engine in a vehicle is operated, vibration generated by the engine is transmitted to the rubber elastic body 26 via the mounting bracket 30, and the rubber elastic body 26 is elastically deformed. At this time, the rubber elastic body 26 acts as a main vibration absorber, and the vibration is absorbed by the vibration absorbing action based on the internal friction of the rubber elastic body 26 and the vibration transmitted to the vehicle body via the outer cylinders 12 and 14 is reduced. The In vehicles such as automobiles, the engine generates idle vibrations that are relatively high-frequency vibrations during idling, and the engine generates shake vibrations that are relatively low-frequency vibrations when traveling at a predetermined speed or higher. appear.

  In the vibration isolator 10, a part of the shake orifice 118 on the main liquid chamber 36 side is a common orifice part 70 that forms a part of the idle orifice 120, and a boundary between the common orifice part 70 and the dedicated orifice part 68. Since the orifice opening 76 communicating with the orifice space 114 of the cylinder chamber 60 is formed in the vicinity of the portion, the main liquid chamber 36 and the sub liquid chamber 38 communicate with each other by the shake orifice 118 and the orifice opening 76 is opened. In this case, the idle orifices 120 communicate with each other.

  Further, in the vibration isolator 10, when the plunger member 78 moves from the open position to the closed position against the magnetic repulsive force of the magnets 128 and 130 by the hydraulic pressure in the hydraulic space 112 of the cylinder chamber 60, the orifice opening is performed. 76 is closed, and when the magnet 128, 130 returns to the open position from the closed position due to the magnetic repulsive force, the orifice opening 76 is opened. Therefore, when the shake vibration is input, the plunger member 78 in the open position is closed. As the rubber elastic body 26 is elastically deformed, the liquid passes back and forth between the main liquid chamber 36 and the sub liquid chamber 38 only through the shake orifice 118, and when the idle vibration is input, the liquid is moved to the closed position. When the plunger member 78 is returned to the open position, both the shake orifice 118 and the idle orifice 120 are opened. But with the elastic deformation of the rubber elastic body, the back and forth of liquid between the flow resistance of the liquid is relatively small idle orifice 120 and preferentially through the main liquid chamber 36 and the auxiliary liquid chamber 38.

  That is, in the vibration isolator 10, when a shake vibration having a relatively low frequency and a large amplitude is input, the rubber elastic body 26 is elastically deformed by the shake vibration, and a relatively large liquid is contained in the main liquid chamber 36. As the pressure changes, the liquid flows from the main fluid chamber 36 into the hydraulic space 112 through the check valve 116 when the hydraulic pressure in the main fluid chamber 36 periodically increases, and the hydraulic pressure in the hydraulic space 112 is also main. The pressure rises to an equilibrium pressure that is substantially in equilibrium with the fluid pressure at the time of ascent in the liquid chamber 36.

  Here, in the vibration isolator 10, the magnetic repulsive force of the magnets 128 and 130 is set to be smaller than a value corresponding to the hydraulic pressure (equilibrium pressure) in the hydraulic pressure space 112 when the shake vibration is input, As a result, when shake vibration is input, the plunger member 78 moves intermittently from the open position to the closed position against the magnetic repulsive force, and is held at the closed position by the hydraulic pressure in the hydraulic pressure space 112. .

  Accordingly, in the vibration isolator 10, when shake vibration is input, the liquid moves back and forth between the main liquid chamber 36 and the sub liquid chamber 38 only through the shake orifice 118 in accordance with the elastic deformation of the rubber elastic body 26. Since vibration (low frequency range vibration) can be absorbed, shake vibration transmitted from the engine side to the vehicle body side can be reduced.

  At this time, since the flow resistance of the liquid in the shake orifice 118 is set (tuned) so as to correspond to the frequency and amplitude of the shake vibration, the main liquid chamber 36 and the sub liquid chamber 38 pass through the shake orifice 118. A resonance phenomenon (liquid column resonance) occurs in the liquid flowing back and forth, and shake vibration can be absorbed particularly effectively by the action of the liquid column resonance.

  In the vibration isolator 10, when idle vibration having a relatively high frequency and a small amplitude is input, the rubber elastic body 26 is elastically deformed by the idle vibration and a relatively small liquid is contained in the main liquid chamber 36. Since a pressure change occurs, in this case as well, liquid flows from the main fluid chamber 36 into the hydraulic pressure space 112 through the check valve 116 when the hydraulic pressure in the main fluid chamber 36 periodically increases, and the hydraulic pressure space 112. The fluid pressure in the interior rises to reach an equilibrium pressure that is substantially in equilibrium with the fluid pressure (maximum value) at the time of ascent in the main fluid chamber 36.

  However, in the vibration isolator 10, the magnetic repulsive force of the magnets 128 and 130 is set to be larger than the value corresponding to the equilibrium pressure in the hydraulic pressure space 112 when the idle vibration is input. When the member 78 is in the open position, it is held in the open position by a magnetic repulsive force, and when it is in the closed position, it moves (returns) from the closed position to the open position by the magnetic repulsive force.

  When the plunger member 78 moves to the open position side, the hydraulic pressure release path 126 formed in the plunger member 78 causes the liquid in the hydraulic pressure space 112 closed from the outside to flow into the orifice space 114. Therefore, the hydraulic pressure in the hydraulic pressure space 112 is prevented from increasing, and the plunger member 78 can be moved smoothly toward the open position with a low movement resistance.

  Accordingly, in the vibration isolator 10, when the idle vibration is input, the main liquid chamber 36 is preferentially passed through the idle orifice 120 having a small liquid flow resistance with respect to the shake orifice 118 in accordance with the elastic deformation of the rubber elastic body 26. Since the liquid moves between the auxiliary liquid chamber 38 and the auxiliary liquid chamber 38, idle vibration transmitted from the engine side to the vehicle body side can be reduced.

  At this time, since the flow resistance of the liquid in the idle orifice 120 is set (tuned) so as to correspond to the frequency and amplitude of the idle vibration, the main liquid chamber 36 and the sub liquid chamber 38 pass through the idle orifice 120. A resonance phenomenon (liquid column resonance) occurs in the liquid flowing back and forth, and idle vibration can be absorbed particularly effectively by the action of the liquid column resonance.

  As a result, according to the vibration isolator 10, the main liquid chamber 36 and the sub liquid chamber 38 are communicated with each other without using a valve mechanism that operates in response to external control and power supply such as an electromagnetic solenoid or a pneumatic solenoid. The orifice to be switched can be switched to either the shake orifice 118 or the idle orifice 120 as a driving force in accordance with the frequency of the input vibration.

  In the vibration isolator 10, the magnets 128 and 130 cause a magnetic repulsive force to act on the plunger member 78, and the magnetic repulsive force urges the plunger member 78 toward the open position, so that the plunger member 78 When the shake vibration is input, the orifice 128 is moved to the closed position against the magnetic repulsive force of the magnets 128 and 130 by the hydraulic pressure in the hydraulic space 112, and the orifice opening 76 is closed. The biasing member such as a coil spring is moved in the apparatus in order to return the plunger member 78 in the closed position to the open position by moving to the open position by the magnetic repulsive force 128, 130 and opening the orifice opening 76. This eliminates the need for a seat receiving portion or the like for holding in a predetermined posture, and eliminates the need to assemble the urging member inside the device such as the cylinder chamber 60. Therefore, the shape and structure of the component parts of the device can be simplified as compared with the conventional vibration isolator that uses a coil spring or the like to return the plunger member 78 to the open position, and the assembly work (assembly work) of the device is also possible. It will be easy.

Further, in the vibration isolator 10, when the plunger member 78 moves to the closed position, the liquid filled in the device is not a completely incompressible fluid but has a certain elastic property. The liquid in the pressurized state of the main liquid chamber 36 (hydraulic pressure) is intermittently supplied through the check valve 116, and the hydraulic pressure in the hydraulic pressure space 112 is synchronized with the change in the hydraulic pressure in the main liquid chamber 36. Periodically changing phenomenon occurs. For this reason, the plunger member 78 in the closed position is vibrated corresponding to the change in the hydraulic pressure in the hydraulic pressure space 112, but the outer peripheral surface of the plunger member 78 exceeds the upper and lower regions of the orifice opening 76. Wrapping. These overlap amounts OL _U and OL _A are set sufficiently larger (for example, about 2.5 to 3.0 mm) than the amplitude of the plunger member 78 that is in the closed position and vibrates. Thereby, even if the plunger member 78 vibrates due to a change in the hydraulic pressure in the hydraulic pressure space 112, the closed state of the orifice opening 76 can be reliably maintained.

(Second Embodiment)
6 and 7 show a vibration isolator according to a second embodiment of the present invention. In the vibration isolator 140 according to this embodiment, the same parts as those of the vibration isolator 10 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The vibration isolator 140 according to the present embodiment is different from the vibration isolator 10 according to the first embodiment in that the fixed magnet 128 is omitted from the upper orifice member 44 and the holder member 92 is made of iron having ferromagnetism. , Nickel, and an alloy thereof (ferromagnetic material), and the top plate portion 94 is configured as an attracted portion of the fixed magnet 128. That is, in the vibration isolator 140, the movable magnet 130 is disposed on the plunger member 78, and the magnetic pole surface 130S of the movable magnet 130 faces the top plate portion 94 of the holder member 92 along the axial direction. Accordingly, the movable magnet 130 always applies a magnetic attraction force to the top plate portion 94, and this magnetic attraction force biases the plunger member 78 toward the open position (see FIG. 6). In the case of the present embodiment, even if the magnetic pole surface 130N of the movable side magnet 130 is opposed to the top plate portion 94 of the holder member 92, a magnetic attractive force to the plunger member 78 can be generated.

  As in the case of the first embodiment, the movable side magnet 130 inserted into the insertion hole 135 of the boss portion 134 of the plunger member 78 has the magnetic pole surface 130S on the lower end side of the boss portion 134 (top plate portion 80). ) With respect to the lower end surface thereof by a predetermined distance L (see FIG. 7). Accordingly, as shown in FIG. 6, when the plunger member 78 moves to the open position and the top plate portion 80 is brought into contact with the top plate portion 94 of the holder member 92, the gap between the magnetic pole surface 130 </ b> S and the top surface of the top plate portion 80. A gap G having a width L is formed along the axial direction. The gap G prevents the magnetic surface 130 </ b> S from being in close contact with the top plate portion 80 of the holder member 92, and prevents the magnetic attractive force that the movable magnet 130 acts on the holder member 92 from becoming excessive.

  That is, since the magnetic attractive force by the movable magnet 130 increases in inverse proportion to the square of the amount of decrease in the distance from the magnetic pole surface 130S to the holder member 92, the distance from the magnetic pole surface 130S to the holder member 92 becomes zero. In this case, it becomes difficult to separate the plunger member 78 from the holder member 92 against the magnetic attractive force of the movable magnet 130 by the hydraulic pressure in the hydraulic space 112.

  Therefore, the vibration isolator 140 has a predetermined interval L along the axial direction between the magnetic pole surface 130S of the movable magnet 130 and the top plate portion 94 of the holder member 92 in a state where the plunger member 78 is in the open position. A gap G is formed, and the maximum value of the magnetic attractive force that the movable magnet 130 acts on the top plate portion 94 of the holder member 92 is limited by the aerodynamic G. Specifically, the interval L is set so that the maximum value of the magnetic attractive force generated between the movable magnet 130 and the holder member 92 is smaller than the value corresponding to the hydraulic pressure in the hydraulic pressure space 112. ing.

  As shown in FIG. 7, the upper orifice member 44 is integrally formed with a thick disc-like stopper portion 142 protruding downward at the center of the lower surface of the top plate portion 45. When the plunger member 78 moves to the closed position, the stopper portion 142 abuts on the magnetic pole surface 130N of the movable side magnet 130 to limit the upward movement of the plunger member 78, and accurately positions the plunger member 78 to the closed position. To do. The upper orifice member 44 is formed of aluminum, an aluminum alloy, a resin material or the like that does not generate a magnetic attractive force between the upper orifice member 44 and the movable side magnet 130.

  Next, the operation of the vibration isolator 140 according to the embodiment of the present invention will be described.

  In the vibration isolator 140, the movable magnet 130 applies a magnetic attractive force to the top plate portion 94 of the holder member 92, and the plunger member 78 is biased toward the open position by the repulsive force of the magnetic attractive force. The plunger member 78 moves to the closed position against the magnetic attraction force by the hydraulic pressure in the hydraulic space 112 when the shake vibration is input, and closes the orifice opening 76, and when the idle vibration is input. A biasing member such as a coil spring is used to return the plunger member 78 in the closed position to the open position by moving to the open position by the magnetic attractive force of the movable magnet 130 and opening the orifice opening 76. This eliminates the need for a seat receiving portion or the like for holding the device in a predetermined posture, and eliminates the need to assemble the biasing member inside the device such as the cylinder chamber 60. Compared with a conventional vibration isolator that uses a coil spring or the like to return the nanger member 78 to the open position, the shape and structure of the component parts of the device can be simplified, and the assembly work (assembly work) of the device is also simple. Become.

  Further, in the vibration isolator 140, compared to the vibration isolator 10 of the first embodiment, the only necessary magnet is the movable side magnet 130, and the fixed side magnet 128 can be eliminated. The structure can be further simplified, and the assembly work of the apparatus (assembly work) is further simplified.

  6 and 7, the movable side magnet 130 is disposed on the plunger member 78 and the holder member 92 is configured as an attracted portion of the movable side magnet 130. Conversely, the fixed side magnet 128 may be disposed on the holder member 92 and the plunger member 78 may be provided with a portion to be attracted to the fixed side magnet 128. FIG. 8 shows a vibration isolator according to the present embodiment in which the fixed magnet 128 is disposed on the holder member 92 and the attracted portion 146 is provided on the plunger member 78. A cylindrical boss portion 144 is formed at the center portion of the top plate portion 94 of the holder member 92 so as to protrude upward. In a fitting insertion hole 145 formed on the inner peripheral side of the boss portion 144. A thick disk-shaped stationary magnet 128 is inserted and fixed. On the other hand, the plunger member 78 is formed of ferromagnetic iron, nickel, or an alloy thereof (ferromagnetic material). The bottom plate 80 of the plunger member 78 has a bottomed cylindrical shape that opens downward. The adsorbed portion 146 formed in the above is integrally formed.

  In the vibration isolator 140 shown in FIG. 8, when the plunger member 78 is in the open position, the top plate portion 80 of the plunger member 78 abuts on the outer peripheral side of the top plate portion 94 of the holder member 92, and the boss portion 144 and the fixed portion are fixed. The side magnets 128 are inserted into the attracted portions 146, respectively. At this time, a gap G is formed between the magnetic pole surface 128S of the fixed-side magnet 128 and the bottom surface portion of the attracted portion 146 (the lower surface side of the top plate portion 80). As in the case shown in FIGS. 6 and 7, the gap G has a predetermined interval L along the axial direction. The magnetic pole surface 128 </ b> S is in close contact with the attracted portion 146, and the fixed-side magnet 128. Prevents the magnetic attractive force acting on the plunger member 78 from becoming excessive.

  In the vibration isolator 140 shown in FIG. 8, the stationary magnet 128 applies a magnetic attraction force to the attracted portion 146 of the plunger member 78, and the plunger member 78 is moved to the open position by this magnetic attraction force. Be energized. Therefore, even with the vibration isolator 140 shown in FIG. 8, a seat for holding a biasing member such as a coil spring in a predetermined posture in the apparatus in order to return the plunger member 78 in the closed position to the open position. A conventional vibration isolator that uses a coil spring or the like to return the plunger member 78 to the open position, because the receiving portion or the like is not necessary and the work of assembling the urging member inside the device such as the cylinder chamber 60 can be made unnecessary. In comparison, the shape and structure of the component parts of the apparatus can be simplified, and the assembly work (assembly work) of the apparatus can be simplified.

  In the vibration isolators 10 and 140 according to the present embodiment, the main liquid chamber 36 side of the outer peripheral groove 66 of the upper orifice member 44 is used as the common orifice portion 70, and the sub liquid chamber 38 side is used as the dedicated orifice portion 68. Although the orifice portion 70 is shared by the shake orifice 118 and the idle orifice 120, another groove portion separated from the outer peripheral groove 66 forming the shake orifice 118 is formed in the upper orifice member 44, and this another groove portion is used as the idle orifice. It may be made a part of 120.

  In the vibration isolators 10 and 140, one of the two orifices (the first restriction passage and the second restriction passage) is a shake orifice 118 corresponding to shake vibration, and the other is an idle orifice 120 corresponding to idle vibration. However, the two first restriction passages and the second restriction passage need not necessarily correspond to the shake vibration and the idle vibration, and the first restriction passage corresponds to the vibration of a relatively low frequency range. The second restriction path only needs to correspond to vibration in a relatively high frequency range.

  In the vibration isolator 10, 140, the mounting bracket 30 is connected to the engine side and the outer cylinders 12, 14 are connected to the vehicle body side. Conversely, the mounting bracket 30 is connected to the vehicle body side. In addition to the connection, the outer cylinders 12 and 14 may be connected to the engine side.

  Further, in the vibration isolator 10, 140 according to the present embodiment, the liquid is supplied from the main fluid chamber 36 into the hydraulic space 130 through the check valve 116 when the hydraulic pressure in the main fluid chamber 36 is increased, and this hydraulic space 130. The hydraulic pressure inside is increased to an equilibrium pressure corresponding to the upper limit value of the hydraulic pressure in the main liquid chamber 36, and when the shake vibration is input, the plunger member 78 is moved from the open position to the closed position by the hydraulic pressure (positive pressure) in the hydraulic pressure space 130. Contrary to this, the check valve is configured so that the liquid can flow only from the hydraulic space 130 to the main liquid chamber 36, and when the hydraulic pressure in the main liquid chamber 36 decreases, By causing the liquid to flow out from the hydraulic pressure space 130 into the main fluid chamber 36 through the check valve, the hydraulic pressure in the hydraulic pressure space 130 is reduced to an equilibrium pressure corresponding to the lower limit value of the hydraulic pressure in the main fluid chamber 36, When vibration is input, the pressure is reduced by the hydraulic pressure (negative pressure) in the hydraulic pressure space 130. The Ja member 78 from the open position may be be moved to the closed position.

It is sectional drawing along the axial direction which shows the structure of the vibration isolator which concerns on the 1st Embodiment of this invention, and has shown the state which has a plunger member in an open position. It is sectional drawing along the axial direction which shows the structure of the vibration isolator shown by FIG. 1, and has shown the state which has a plunger main body in the obstruction | occlusion position. It is sectional drawing which shows the structure of the partition metal fitting and plunger member in the vibration isolator shown by FIG. 1, and has shown the state which has a plunger member in an open position. It is sectional drawing which shows the structure of the partition metal fitting and plunger member in the vibration isolator shown by FIG. 1, and has shown the state which has a plunger member in a obstruction | occlusion position. It is a disassembled perspective view which shows the structure of the partition metal fitting and plunger member in the vibration isolator shown by FIG. It is sectional drawing along the axial direction which shows the structure of the vibration isolator which concerns on the 2nd Embodiment of this invention, and has shown the state which has a plunger member in an open position. It is sectional drawing along the axial direction which shows the structure of the vibration isolator shown by FIG. 6, and has shown the state which has a plunger main body in the obstruction | occlusion position. It is sectional drawing along the axial direction which shows the structure of the vibration isolator which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

10 Vibration isolator 12 Upper outer cylinder (first mounting part)
14 Lower outer cylinder (first mounting part)
26 Rubber elastic body (elastic body)
30 Mounting bracket (second mounting part)
34 Partition bracket (second mounting part)
36 Main liquid chamber 38 Sub liquid chamber 40 Diaphragm 60 Cylinder chamber 64 Lower orifice passage 66 Outer peripheral groove 68 Dedicated orifice part 70 Common orifice part 76 Orifice opening 78 Plunger member 94 Top plate part (adsorbed part)
106 Valve body 112 Hydraulic space 114 Orifice space 116 Check valve 118 Shake orifice 120 Idle orifice 128 Fixed magnet (magnetic biasing means)
128S, 128N Magnetic pole surface 130 Fixed side magnet (magnetic biasing means)
130S, 130N Magnetic pole surface 140 Vibration isolator 146 Adsorbed part

Claims (6)

A first attachment member coupled to one of the vibration generator and the vibration receiver;
A second attachment member coupled to the other of the vibration generating portion and the vibration receiving portion;
An elastic body disposed between the first mounting member and the second mounting member;
A main liquid chamber in which a liquid is sealed with the elastic body as a part of a partition wall, and the internal volume changes with elastic deformation of the elastic body;
A secondary liquid chamber in which liquid is enclosed and the internal volume can be expanded and contracted;
A first restricting passage communicating the main liquid chamber and the sub liquid chamber with each other;
A second restricting passage that connects the main liquid chamber and the sub liquid chamber to each other, and has a smaller flow resistance of the liquid than the first restricting passage;
A cylinder chamber provided between the main liquid chamber and the sub-liquid chamber and enclosing a liquid;
The cylinder chamber is partitioned into an orifice space that constitutes a part of the second restriction passage and communicates with the sub liquid chamber and a hydraulic space that is isolated from the second restriction passage, and the orifice space and A plunger member that is movable between a predetermined open position and a closed position along the expansion / contraction direction of the hydraulic pressure space;
An orifice opening provided so as to face the orifice space, and communicating the orifice space with the other part of the second restriction passage;
The reverse is arranged between the main liquid chamber and the hydraulic pressure space, and the liquid can flow out only in one direction between the main liquid chamber and the hydraulic pressure space in accordance with the change of the hydraulic pressure in the main liquid chamber. A stop valve,
Magnetic biasing means for applying a magnetic force to the plunger member and biasing the plunger member toward the open position by the magnetic force;
When the plunger member moves to the closed position against the magnetic force of the magnetic urging means by the hydraulic pressure in the hydraulic pressure space, the orifice opening is closed and the opening is opened by the magnetic force of the magnetic urging means. A vibration isolator that opens the orifice opening when moved to a position.   2. The vibration isolator according to claim 1, wherein the magnetic biasing means biases the plunger member toward the open position by causing a magnetic force to act on the plunger member as a repulsive force.   2. The vibration isolator according to claim 1, wherein the magnetic biasing means biases the plunger member toward the open position by causing magnetic force to act on the plunger member as an attractive force.   The magnetic urging means includes: a magnet member disposed on one side of the partition member that divides the plunger member and the cylinder chamber and the secondary liquid chamber; and at least the magnet member on the other of the plunger member and the partition portion. An anti-vibration device according to claim 3, further comprising: an adsorbed portion provided in an opposing region and formed of a ferromagnetic material.   The magnetic biasing means forms a gap with a predetermined width along the expansion / contraction direction between the magnet member and the attracted portion in a state where the plunger member is in the open position, and The vibration isolator according to claim 4, wherein a maximum attraction force generated between the magnet member and the attracted portion is adjusted.   The magnetic urging means includes a first magnet member disposed on the plunger member, a partition wall section that divides the cylinder chamber and the auxiliary liquid chamber, and the first magnet member along the expansion / contraction direction. The vibration isolator according to claim 1, further comprising a second magnet member disposed so as to face each other.

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