JP2007120565A - Vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a response speed from lowering owing to the unstable motion of a check valve when switching a device mode, and a plunger member from making it impossible to normally move to a position corresponding to the frequency of an input vibration. <P>SOLUTION: In a vibration isolator 10, a disk-like valve body 102 is arranged in a valve body housing chamber 114 so as to move for a valve seat surface 156 of a valve seat part 148 in the axial contact and separation direction, then a valve seat openings 96 and 104 can be opened and closed by contacting and separating the valve seat part 148 according to the liquid pressure change in a main liquid chamber 42 without elastically changing the valve body 102. For example, compared with a conventional vibration insulator in which a valve body is made of rubber material, deflected and deformed when the valve seat opening is opened, the valve body 102 can be increased in rigidity for the liquid pressure in the main liquid chamber 42, which can prevent the deterioration and damage from occurring with time in the valve body 102. <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 energized 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 by the biasing force of the member.

  In the vibration isolator of Patent Document 1, a partition member that divides a space in the outer cylinder into a main liquid chamber and a sub liquid chamber is provided, and a plunger member is provided in a cylinder chamber formed on the inner peripheral side of the partition member. When the plunger member moves to the closed position, the orifice opening facing the cylinder chamber is closed to close the idle orifice, and when the plunger member returns to the open position. The idle orifice is opened away from the orifice opening.

Further, in the vibration isolator of Patent Document 1, a check valve is provided between the main liquid chamber and the cylinder chamber, and the check valve supplies a liquid in a pressurized state with a change in the liquid pressure in the main liquid chamber. The plunger member is moved to the open position or the closed position corresponding to the frequency of the input vibration by flowing into the cylinder chamber and controlling the fluid pressure in the cylinder chamber to a fluid pressure that balances the fluid pressure in the main fluid chamber. . The check valve has a partition-like valve seat section that partitions between the main liquid chamber and the cylinder chamber (hydraulic pressure space), and is formed in the valve seat section so that the main liquid chamber and the cylinder chamber communicate with each other. A valve seat opening and a rubber valve body that opens and closes the valve seat opening by contacting and separating from the valve seat portion in accordance with a change in the hydraulic pressure in the main liquid chamber.
International Publication WO 2004/081408

  However, in the vibration isolator of Patent Document 1, since the valve body in the check valve is formed of a rubber material, the valve body may be deteriorated over time. Specifically, for example, when the elasticity of the valve body is lowered, plastic deformation may occur in the valve body, and a gap may be formed between the valve body and the valve seat portion. When the liquid leaks through the gap, the moving speed of the plunger member decreases, the response speed when switching the device mode (shake orifice and idle mode) decreases, or the plunger member moves to a position corresponding to the frequency of the input vibration. May not be able to move normally.

  In addition, if the elasticity of the valve body in the check valve decreases, the deformation resistance of the valve body may change from its initial size, and damage such as cracks may easily occur in the stress concentration part of the valve body. In addition, there is a possibility that the response speed at the time of switching the device mode is lowered, or the plunger member cannot be moved normally to the position corresponding to the frequency of the input vibration.

  In view of the above facts, an object of the present invention is to provide a vibration isolator that can effectively prevent the operation of a check valve from becoming unstable due to deterioration or damage of a valve body.

  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 cylinder chamber that is provided between the chamber and filled with a liquid, and a part of the second restriction passage in 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 movable between the closed position and the plunger member, the plunger member is provided so as to face the orifice space, and the orifice space in the second restriction passage communicates with the other portion, whereby the plunger member Is disposed between the orifice opening that is opened when the plunger member moves to the closed position, and is closed between the main liquid chamber and the hydraulic pressure space, and the hydraulic pressure in the main liquid chamber is A check valve capable of allowing liquid to flow only in one direction between the main fluid chamber and the hydraulic space in accordance with the change, and the plunger member are attached to the open position side for reducing the hydraulic space. And the check valve includes a valve body storage chamber provided between the main liquid chamber and the hydraulic space, the main liquid chamber, and the valve body storage chamber. A partition-shaped valve seat portion that is partitioned, a valve seat opening that is provided in the valve seat portion and allows the main liquid chamber and the valve body storage chamber to communicate with each other, and in the valve body storage chamber with respect to the valve seat portion A plate-shaped valve body that is arranged so as to be movable along an opening / closing direction that contacts / separates, and that opens / closes the valve seat opening by contacting / separating with the valve seat portion according to a change in hydraulic pressure in the main liquid chamber; , Provided.

  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, the plunger member in the open position is moved to the closed position by the hydraulic pressure supplied from the main liquid chamber into the hydraulic pressure space through the check valve. When it moves against the liquid, the elastic member is elastically deformed, the liquid moves back and forth between the main liquid chamber and the sub liquid chamber only through the first restricting passage, and the plunger member at the closed position is When returning to the open position by the biasing force of the biasing member, both the first restricting passage and the second restricting passage are opened. However, as the elastic body is elastically deformed, the flow resistance of the liquid is relatively low. Therefore, the liquid goes back and forth between the main liquid chamber and the sub liquid chamber preferentially through the second restricted passage.

  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 urging force of the urging member is set smaller than the value corresponding to the equilibrium pressure in the hydraulic pressure space, the plunger member moves from the open position to the closed position side against the urging force of the urging member. It moves intermittently and is held at the closed position by the hydraulic pressure in the hydraulic pressure space.

  At this time, if the flow resistance of the liquid in the first restriction passage is set (tuned) so as to correspond to the frequency and amplitude of the low-frequency vibration, the main liquid chamber and the auxiliary liquid pass through the first restriction passage. Since a resonance phenomenon (liquid column resonance) occurs in the liquid flowing back and forth between the chambers, low-frequency vibrations can be particularly effectively absorbed 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 urging force of the urging member is set larger than the value corresponding to the equilibrium pressure in the hydraulic pressure space, the urging force of the urging member holds the plunger member in the open position when the plunger member is in the open position. In the closed position, the urging force of the urging member 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, the input vibration (high frequency vibration) can be absorbed, so the high frequency vibration transmitted from the vibration generating part to the vibration receiving part is effective. Can be reduced.

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

  Further, in the vibration isolator according to claim 1, the check valve has a partition shape that partitions the valve body storage chamber provided between the main liquid chamber and the hydraulic pressure space, and the main liquid chamber and the valve body storage chamber. The valve seat portion, the valve seat opening provided in the valve seat portion for communicating the main liquid chamber and the valve body storage chamber with each other, and the opening and closing direction in which the valve seat housing chamber is in contact with and separated from the valve seat portion And a plate-shaped valve body that opens and closes the valve seat opening in contact with and away from the valve seat portion in response to a change in the hydraulic pressure in the main liquid chamber. When the hydraulic pressure rises relative to the hydraulic pressure in the hydraulic pressure space, the valve body is separated from the valve seat portion in the valve body storage chamber by the action of the hydraulic pressure (positive pressure) in the main fluid chamber, and the valve seat opening is opened. Therefore, when pressurized liquid flows into the hydraulic space from the main fluid chamber through the valve seat opening, and when the hydraulic pressure in the main fluid chamber decreases relative to the hydraulic pressure in the hydraulic space The valve body closes to the valve seat portion in the valve body storage chamber by the action of the liquid pressure (negative pressure) in the main liquid chamber and closes the valve seat opening, so that the main liquid chamber and the hydraulic space through the valve seat opening Liquid flow between the two is blocked.

  Therefore, when vibration is input to the first mounting member or the second mounting member and the hydraulic pressure in the main fluid chamber changes periodically, only when the hydraulic pressure in the main fluid chamber rises relative to the hydraulic pressure in the hydraulic pressure space, Pressurized liquid flows from the main fluid chamber into the hydraulic space through the valve seat opening, and when the hydraulic pressure in the main fluid chamber drops, the pressurized liquid flows out from the hydraulic space into the main fluid chamber (leak) Therefore, the fluid pressure in the fluid pressure space is increased by the pressurized liquid flowing in through the valve seat opening, so that the equilibrium pressure is approximately balanced with the fluid pressure (maximum value) when rising in the main fluid chamber. Can be controlled.

  In the vibration isolator according to claim 1, the plate-like valve body is disposed in the valve body storage chamber so as to be movable along the opening / closing direction contacting and separating from the valve seat portion. Even when the body is not elastically deformed, the valve seat can be opened and closed by opening and closing the valve seat opening by opening and closing the valve seat according to the change in the hydraulic pressure in the main fluid chamber. Compared with the conventional vibration isolator that bends and deforms when the seat opening is opened, the rigidity of the valve body can be made sufficiently higher than the hydraulic pressure in the main fluid chamber, so that the valve body is deteriorated and damaged over time. Can be prevented.

  As a result, the vibration isolator according to claim 1 can effectively prevent the check valve operation from becoming unstable due to deterioration or damage of the valve body, so that the check valve operation becomes unstable. Thus, it is possible to prevent over a long period of time that the response speed when switching the apparatus mode is lowered and the plunger member cannot be moved normally to the position corresponding to the frequency of the input vibration.

  A vibration isolator according to claim 2 of the present invention is the vibration isolator according to claim 1, wherein the rigidity of the valve body is received by the hydraulic pressure in the main liquid chamber when the hydraulic pressure in the main liquid chamber changes. Is characterized in that it is set so that a substantially undeformed state is maintained along the bending direction.

  A vibration isolator according to claim 3 of the present invention is the vibration isolator according to claim 1 or 2, wherein the valve body is formed of a resin material or a metal material.

  A vibration isolator according to claim 4 of the present invention is the vibration isolator according to any one of claims 1 to 3, wherein the valve element is applied when the hydraulic pressure in the main liquid chamber in the valve seat changes. The contacting valve seat surface is formed of an elastic material.

  The vibration isolator according to claim 5 of the present invention is the vibration isolator according to any one of claims 1 to 4, wherein a guide hole penetrating in the opening / closing direction is formed in a central portion of the valve body, A guide shaft that extends in the opening / closing direction and is slidably inserted into the guide hole is provided in the valve body storage chamber.

  A vibration isolator according to claim 6 of the present invention is the vibration isolator according to any one of claims 1 to 5, further comprising a valve body urging member that urges the valve body toward the valve seat. It is characterized by that.

  As described above, according to the vibration isolator according to the present invention, the operation of the check valve becomes unstable, the response speed when switching the device mode is reduced, and the plunger member is adjusted to the frequency of the input vibration. It is possible to prevent a normal movement to the corresponding position.

  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.

(Configuration of the embodiment)
1 and 2 show a vibration isolator according to an embodiment of the present invention. As shown in FIG. 1, the vibration isolator 10 is provided with an outer cylinder fitting 12 formed in a thin cylinder on the outer peripheral side thereof, and a mounting bracket 20 is substantially coaxial on the inner circumference side of the outer cylinder fitting 12. Are arranged. An annular flange portion 14 is formed at the upper end portion of the outer tube member 12 so as to be bent toward the outer peripheral side, and a caulking portion 16 is formed at the lower end portion so as to be bent in a tapered shape toward the inner peripheral side when the apparatus is assembled. In the middle of the flange portion 14 and the caulking portion 16, a throttle portion 18 bent in a V-shaped cross section toward the inner peripheral side is formed over the entire circumference. The vibration isolator 10 is connected to the vehicle body side of the vehicle via the holder fitting when the outer cylinder fitting 12 is inserted into a cup-shaped holder fitting (not shown).

  The mounting bracket 20 is formed in a columnar shape having a substantially constant outer diameter on the upper end side, and is formed in a substantially truncated cone shape whose outer diameter is reduced downwardly on the lower end side. Is formed with a screw hole 22 along the axis S from the upper end surface toward the lower end side. The vibration isolator 10 is connected and fixed to the engine side of the vehicle via a fastening member such as a bolt screwed into the screw hole 22 of the mounting bracket 20 and a bracket stay.

  In the vibration isolator 10, a rubber elastic body 24 formed in a substantially thick ring shape is disposed between the outer cylinder fitting 12 and the attachment fitting 20. The outer peripheral surface of the rubber elastic body 24 is vulcanized and bonded to the upper side of the narrowed portion 18 on the outer peripheral surface of the outer tube fitting 12, and the inner peripheral surface is vulcanized and bonded to the lower end side of the outer peripheral surface of the mounting bracket 20. . Thereby, the rubber elastic body 24 elastically connects the outer cylinder fitting 12 and the mounting fitting 20.

  The rubber elastic body 24 is formed in a substantially C shape whose cross section is inclined downward from the mounting bracket 20 toward the outer cylindrical bracket 12. As a result, a substantially frustoconical concave portion 26 whose inner diameter becomes narrower from the lower side to the upper side is formed in the central portion of the lower surface of the rubber elastic body 24. The rubber elastic body 24 is integrally formed with a stopper section 28 having a rectangular cross section extending from the outer peripheral portion of the upper end to the outer peripheral side. The stopper section 28 is a peripheral portion of the flange portion 14 of the outer cylinder fitting 12. It is vulcanized and bonded to a part along the direction. The stopper 28 abuts against a bracket stay or the like to limit the displacement on the engine side when a large relative displacement occurs on the engine side along the axial direction with the vibration isolator 10 attached to the vehicle. At the same time, the generation of collision noise is prevented.

  The rubber elastic body 24 is integrally formed with an inner cushion portion 30 that covers the lower end portion of the mounting bracket 20 on the inner peripheral portion of the lower end thereof, and a step portion 32 on the inner peripheral side of the throttle portion 18 of the outer cylindrical bracket 12. Are integrally formed. The stepped portion 32 has a flat bottom surface and is supported by the throttle portion 18 so that deformation in the axial direction from the outer peripheral side is limited. The rubber elastic body 24 is integrally formed with a thin cylindrical covering portion 34 that extends downward from the outer peripheral portion of the lower end of the step portion 32. The covering portion 34 extends to the lower end side so as to cover the inner peripheral surface of the outer cylinder fitting 12 and is vulcanized and bonded to the outer cylinder fitting 12.

  A partition fitting 36 (see FIG. 3) formed in a substantially thick disk shape as a whole is fitted into the vibration isolator 10 on the inner peripheral side of the outer cylinder fitting 12. The partition metal 36 abuts its outer peripheral surface on the upper surface side of the stepped portion 32 and presses the outer peripheral surface against the inner peripheral surface of the outer cylindrical metal member 12 via the covering portion 34. In addition, an annular support cylinder 38 is fitted into the vibration isolator 10 below the partition metal 36 on the inner peripheral side of the outer cylinder metal 12. The upper end side of the support cylinder 38 is brought into contact with the outer peripheral portion of the lower surface of the partition fitting 36, and the outer peripheral surface is pressed against the inner peripheral surface of the outer cylinder fitting 12 through the covering portion 34. In the vibration isolator 10, the inner and outer diameters of the caulking portion 16 of the outer cylinder fitting 12 are reduced from the upper end side toward the lower end side in a state where the partition fitting 36 and the support cylinder 38 are fitted and inserted into the outer cylinder fitting 12 at the time of assembly. It is bent so as to have a diameter. As a result, the partition fitting 36 and the support cylinder 38 are fixed between the stepped portion 32 (the throttle portion 18) and the caulking portion 16 in the outer cylinder fitting 12.

  The support cylinder 38 is provided with a diaphragm 40 formed into a thin disk shape with a rubber material on the inner peripheral side thereof. The outer peripheral edge of the diaphragm 40 extends over the entire circumference of the support cylinder 38. It is vulcanized and bonded to the peripheral surface. As a result, a substantially cylindrical space (liquid chamber space) in which the upper end side along the axial direction is closed by the rubber elastic body 24 and the lower end side is closed by the diaphragm 40 is formed in the outer cylinder fitting 12. The liquid chamber space is partitioned by the partition metal 36 into a main liquid chamber 42 having the rubber elastic body 24 as a part of the partition wall and a sub liquid chamber 44 having the diaphragm 40 as the partition wall. The main liquid chamber 42 and the sub liquid chamber 44 are filled with a liquid such as water and ethylene glycol, respectively.

  Here, the inner volume of the main liquid chamber 42 changes (expands / contracts) with the elastic deformation of the rubber elastic body 24, and the diaphragm 40 has a sufficiently small load in the direction of expanding / contracting the inner volume of the sub liquid chamber 44. It can be deformed by (hydraulic pressure).

  As shown in FIG. 5, the partition member 36 is provided with an orifice member 46 formed of a metal material such as synthetic resin or aluminum on the lower side thereof, and a bottomed cylindrical shape is formed on the upper side of the orifice member 46. A lid member 48 is disposed. The orifice member 46 is formed in a thick bottomed cylindrical shape whose bottom surface is closed by the bottom plate portion 50, and the dimension along the circumferential direction of the bottom plate portion 50 extends from the inner peripheral side to the outer peripheral side. A plurality of (for example, four) circulation openings 52 formed in a substantially fan shape are formed, and a thick cylindrical boss portion 54 is formed on the inner peripheral side of the circulation opening 52 as shown in FIG. It is integrally formed.

  As shown in FIG. 3, the boss portion 54 has a dimension along the axial direction larger than the thickness of the bottom plate portion 50 and protrudes from the upper surface portion and the lower surface portion of the bottom plate portion 50. A circular concave seat receiving hole 56 is opened in the center of the upper surface of the boss portion 54, and a lower end portion of a coil spring 90 described later is inserted into the seat receiving hole 56. The boss portion 54 is provided with a clearance hole 58 penetrating between the bottom surface of the seat receiving hole 56 and the lower surface of the boss portion 54. The inner diameter of the escape hole 58 is smaller than the inner diameter of the seat receiving hole 56, and a guide cylinder portion 82 of a plunger member 78 described later is inserted into the escape hole 58 in a detachable manner.

  As shown in FIG. 5, the orifice member 46 is formed with a fitting insertion portion 60 having an outer diameter smaller than that of the lower end side at the upper end portion of the outer peripheral surface thereof. The orifice member 46 is formed with a concave groove portion 64 extending along a spiral direction inclined at a predetermined angle with respect to the circumferential direction between the step portion 62 and the lower end portion on the outer peripheral surface.

  In the orifice member 46, as shown in FIG. 6B, a part of the fitting insertion portion 60 is cut out in a concave shape in the axial direction, and one end portion on the main liquid chamber 42 side along the longitudinal direction of the groove portion 64 is formed. Is formed to communicate with the upper surface of the orifice member 46. Further, as shown in FIG. 6C, the orifice member 46 is partially cut out in a rectangular shape in the axial direction, and the other end portion along the longitudinal direction of the groove portion 64 is the orifice member 46. A communication path 68 is formed to communicate with the lower surface of the communication path.

  The groove portion 64 is provided with a common orifice portion 70 in a section from one end on the main liquid chamber 42 side to the middle portion in the longitudinal direction (spiral direction), and a dedicated orifice on the sub liquid chamber 44 side with respect to the common orifice portion 70. A portion 72 is provided. Here, the common orifice portion 70 and the dedicated orifice portion 72 have the same depth along the radial direction, but the common orifice portion 70 has a width along the axial direction of the axis of the dedicated orifice portion 72. It is longer than the width along the direction by a predetermined length. As a result, the common orifice portion 70 has a cross-sectional area larger than the cross-sectional area of the dedicated orifice portion 72, and the cross-sectional area of the common orifice portion 70 is the frequency of idle vibration (for example, 18) generated during idling of the vehicle. To 30 Hz) and amplitude. Further, the path length of the common orifice portion 70 is set to be ½ or less of the dimension (path length) along the longitudinal direction of the groove portion 64.

  As shown in FIG. 6 (A), the orifice member 46 is formed in the vicinity of the boundary portion between the common orifice portion 70 and the dedicated orifice portion 72 in the groove portion 64 from the bottom surface portion on the inner peripheral side of the groove portion 64. An orifice opening 74 penetrating to the inner peripheral surface is formed. The orifice opening 74 is formed in a slot shape elongated in the circumferential direction. Here, the opening area of the orifice opening 74 is equal to or larger than the cross-sectional area of the common orifice portion 70.

  The orifice opening 74 has a substantially semicircular shape at both ends along the inner peripheral end thereof, and an increase in the flow resistance of the liquid in the vicinity of both ends is suppressed. Further, the cross-sectional shape along the liquid flow direction at the inner peripheral edge portion (edge portion) of the orifice opening 74 may be a convex semicircular shape or wedge shape so as to suppress an increase in liquid flow resistance at the edge portion.

  As shown in FIG. 6C, a cylindrical space is formed on the inner peripheral side of the orifice member 46, and this cylindrical space serves as a cylinder chamber 76 in which a plunger member 78 described later is accommodated. . As shown in FIG. 5, the plunger member 78 is formed in a thick disk shape, and a hydraulic space 130 (FIG. 3) that is a small space on the main liquid chamber 42 side along the axial direction of the cylinder chamber 76. And an orifice space 132 (see FIG. 4), which is a small space on the side of the auxiliary liquid chamber 44. As shown in FIG. 5, the plunger member 78 has an edge portion 79 on the lower end side of the outer peripheral surface thereof extending in parallel with the longitudinal direction of the orifice opening 74.

  As shown in FIG. 3, the plunger member 78 is formed with an annular recess 80 extending in the circumferential direction between the peripheral portion and the central portion on the lower surface side. The plunger member 78 is integrally formed with a thick cylindrical guide tube portion 82 projecting downward from the center portion of the lower surface thereof, and a bearing hole penetrating the center portion of the guide tube portion 82 in the axial direction. 84 is drilled. A cylindrical seat receiving projection 86 having a diameter larger than that of the guide cylinder portion 82 is coaxially formed on the plunger member 78 at the proximal end portion of the guide cylinder portion 82. The plunger member 78 is formed with a circular concave relief 88 at the center of the upper surface thereof.

  As shown in FIG. 3, the plunger member 78 is inserted into the cylinder chamber 76 of the orifice member 46 and is movable (slidable) in the axial direction along the inner peripheral surface of the cylinder chamber 76. At this time, the plunger member 78 is coaxially inserted into the seat receiving hole 56 and the escape hole 58 of the orifice member 46 at the front end side of the guide tube portion 82, but the outer diameter of the guide tube portion 82 is set to the seat receiving hole. 56 and the inner diameter of the escape hole 58, the plunger member 78 is not in contact with the bottom plate portion 50 of the orifice member 46, and has a predetermined range along the axial direction (a closed position and an open position described later). Between). In addition, a coil spring 90 is disposed between the bottom plate portion 50 of the orifice member 46 and the plunger member 78 in the partition member 36.

  The upper end of the coil spring 90 is fitted around the outer periphery of the seat receiving projection 86 of the plunger member 78, and the lower end of the coil spring 90 is inserted into the seat receiving hole 56 of the orifice member 46. In this state, the coil spring 90 presses the upper seat surface 138 that is the upper end surface thereof against the peripheral edge of the seat receiving projection 86 of the plunger member 78 and the lower seat surface 134 that is the lower end surface of the coil spring 90 in the seat receiving hole 56. It is brought into pressure contact with the bottom surface portion and is always held in a compressed state by the plunger member 78 and the bottom plate portion 50. Thereby, the coil spring 90 always biases the plunger member 78 upward (to the main liquid chamber 42 side). Here, as the coil spring 90, a straight spring having a substantially constant inner and outer diameter at an arbitrary portion along the axial direction is used.

  As shown in FIG. 3, in the partition member 36, the lid member 48 is fitted and fixed to the outer peripheral side of the fitting portion 60 in the orifice member 46. As a result, the upper end side of the cylinder chamber 76 of the orifice member 46 is closed by the top plate portion 92 of the lid member 48. Here, the top plate portion of the lid member 48 constitutes a valve seat portion 148 of the check valve 128 together with a seat surface sheet 150 described later. As shown in FIG. 5, the lid member 48 is formed with a plurality (four in this embodiment) of valve seat openings 96 formed in a fan shape at the radial intermediate portion of the top plate portion 92. . These valve seat openings 96 are arranged so as to have a symmetrical positional relationship (point symmetry) about the axis S. The lid member 48 has a notch 98 formed on the outer peripheral portion thereof so as to face the communication path 66 (see FIG. 6B) on the upper end side of the orifice member 46. One end portion of the common orifice portion 70 communicates with the inside of the auxiliary liquid chamber 44 through the cutout portion 98 of the lid member 48 and the communication passage 66.

  As shown in FIG. 7A, a thick disk-shaped seat surface sheet 150 is attached to the top plate portion 92 of the lid member 48 by vulcanization adhesion, adhesion, or the like. The seat surface sheet 150 is formed of a rubber material, a flexible resin material, or the like. The seat surface sheet 150 has a circular insertion opening 152 formed at the center thereof, and the outer peripheral side of the insertion opening 152. A plurality of (four in this embodiment) valve seat openings 104 are formed. Each of the valve seat openings 104 is formed in the same shape as the valve seat opening 96 of the lid member 48 and is disposed at the same position as the valve seat opening 96 with the axis S as a reference. The seat sheet 150 is attached to the top plate portion 92 so that the valve seat opening 104 coincides with the valve seat opening 96 of the lid member 48. Accordingly, the valve seat opening 96 and the valve seat opening 104 communicate with each other, and communicate with each other with the main liquid chamber 42 and a valve body storage chamber 114 described later. Further, the lower surface portion of the seat surface sheet 150 is formed in a planar shape, and is a valve seat surface 156 of the valve seat portion 148 in which a later-described valve body 102 can be contacted in a surface contact state.

  As shown in FIG. In the partition metal 36, a substantially disc-shaped holder member 100 is disposed between the lid member 48 and the plunger member 78, and a disc-shaped valve body 102 is disposed between the holder member 100 and the lid member 48. Is intervening. As shown in FIG. 3, the holder member 100 is formed with a valve body holder 104 having a bottomed cylindrical shape having a shallow bottom at the center thereof, and from the upper end portion of the valve body holder 104 to the outer peripheral side. An extending annular flange portion 106 is bent. The holder member 100 is formed with a plurality of communication openings 108 each formed in a fan shape on the outer periphery of the bottom plate portion 105 of the valve body holder 104.

  As shown in FIG. 7B, the valve body 102 is formed in a disk shape having a substantially constant thickness, and the upper surface portion and the lower surface portion thereof are planar. The valve body 102 is formed with a circular guide hole 103 at the center thereof. Further, the valve body 102 has sufficiently high rigidity with respect to the hydraulic pressure in the main liquid chamber 42, so that the hydraulic pressure from the main liquid chamber 42 is changed when the hydraulic pressure in the main liquid chamber 42 changes. Even if it receives, a bending deformation does not arise substantially. Here, the valve body 102 is made of a resin material such as polyamide, polyacetal, or PPS, or a metal material having a relatively low specific gravity such as an aluminum alloy.

  As shown in FIG. 3, the holder member 100 is integrally formed with a thick disc-shaped boss portion 110 at the center portion of the bottom plate portion 105, and an axial center from the bottom surface center portion of the boss portion 110. A round rod-shaped guide rod 120 protruding downward along S is integrally formed. Also, a guide rod 158 having a larger diameter than the guide rod 120 is integrally formed at the center of the upper surface of the boss portion 110 so as to protrude upward.

  Here, between the top plate portion 92 of the lid member 48 and the bottom plate portion 105 of the holder member 100, a valve body that is a disk-shaped space having a constant thickness along the axial direction on the outer peripheral side of the fitting insertion hole 112. A storage chamber 114 is formed, and the valve body 102 is stored in the valve body storage chamber 114. The upper end surface of the guide rod 158 is brought into contact with the top plate portion 92 of the lid member 48 through the insertion opening 152, and the lower portion of the guide rod 158 is inserted into the guide hole 103 of the valve body 102. ing.

  The thickness of the valve body 102 is thinner by a predetermined length than the dimension along the axial direction of the valve body storage chamber 114, and the dimensions of the valve body 102 and the valve body storage chamber 114 in the valve body storage chamber 114. It is possible to move within a range (stroke) corresponding to the difference. The inside of the guide hole 103 of the valve body 102 is slightly larger in diameter than the outer diameter of the guide rod 158, so that the valve body 102 can move and be guided in the axial direction along the outer peripheral surface of the guide rod 158. The displacement in the radial direction is limited by the guide rod 158.

  As shown in FIG. 3, the valve body 102 has an outer peripheral end positioned radially outside the outer peripheral ends of the valve seat openings 96 and 104 in the lid member 48 along the radial direction, and the communicating opening of the holder member 100. The outer peripheral end 108 is positioned on the inner peripheral side. As a result, the valve body 102 closes the valve seat openings 96 and 104 with the upper surface portion in contact with the top plate portion 92 (closed state), and as shown in FIG. When they are separated along the direction (open state), the valve seat openings 96 and 104 allow the main liquid chamber 42 and the valve body storage chamber 114 to communicate with each other, and the valve body storage chamber 114 passes through the communication opening 108 in the cylinder chamber 76. Therefore, the main liquid chamber 42 and the cylinder chamber 76 communicate with each other through the valve body storage chamber 114.

  Here, the valve body 102, the lid member 48 and the holder member 100 housed in the valve body housing chamber 114 constitute a check valve 128 (see FIG. 5) between the main liquid chamber 42 and the cylinder chamber 76. The check valve 128 allows the liquid to flow only from the main liquid chamber 42 into the cylinder chamber 76 (hydraulic pressure space 130), but the liquid flows out from the hydraulic pressure space 130 into the main liquid chamber 42. Is configured to prevent.

  The guide rod 120 of the holder member 100 is inserted into the bearing hole 84 of the plunger member 78 so as to be relatively slidable along the axial direction. Here, when one of the guide cylinder portion 82 and the guide rod 120 in which the bearing hole 84 is formed is made of metal, the other is a material whose Young's modulus such as resin is different by a predetermined value or more and whose friction resistance is small. It is preferable to form by. Alternatively, one or both of the inner peripheral surface of the bearing hole 84 and the outer peripheral surface of the guide rod 120 may be coated with a material having lubricity and high wear resistance to suppress the frictional resistance. Further, the guide rod 120 protrudes to the lower side of the orifice member 46 through the inside of the seat receiving hole 56 and the escape hole 58 of the orifice member 46.

  The orifice space 132 of the cylinder chamber 76 is always in communication with the auxiliary liquid chamber 44 through the plurality of flow openings 52 of the orifice member 46, the seat receiving holes 56 and the escape holes 58. Further, in the vibration isolator 10, as shown in FIG. 1, the outer peripheral side of the groove portion 64 in the orifice member 46 is blocked by the inner peripheral surface of the outer cylindrical metal member 12 through the covering portion 34. As a result, a shake orifice 122 that is an elongated space along the spiral direction is formed in the groove portion 64, and one end of the shake orifice 122 that is the first restriction passage is at the communication passage 66 of the orifice member 46 and the lid. The other end of the member 48 is connected to the sub liquid chamber 44 through the communication path 68 of the orifice member 46 while being connected to the main liquid chamber 42 through the notch 98 of the member 48.

  Here, the shake orifice 122 is configured by the entire groove portion 64 including the common orifice portion 70 and the dedicated orifice portion 72 having different cross-sectional areas and the communication passages 66 and 68. The shake orifice 122 has a path length and a cross-sectional area, that is, a liquid flow resistance, set so as to correspond to a shake vibration (for example, 9 to 15 Hz) that is a relatively low frequency vibration of the input vibration. Tuning).

  The common orifice part 70 in the groove part 64 forms a part of the idle orifice 124 corresponding to idle vibration (for example, 18 to 30 Hz) that is vibration in a high frequency range relatively to the shake vibration. The idle orifice 124, which is the second restriction passage, is constituted by the common orifice portion 70, the orifice opening 74, and the orifice space 132 in the orifice member 46. The path length and the cross-sectional area, that is, the flow resistance of the liquid is idle. It is set (tuned) to handle vibration. Here, the flow resistance of the liquid in the idle orifice 124 is smaller than the flow resistance of the liquid in the shake orifice 122.

  In the vibration isolator 10, as shown in FIG. 2, when the plunger member 78 moves (lowers) to the closed position, the orifice opening 74 of the orifice member 46 is closed by the outer peripheral surface of the plunger member 78, and the common orifice portion 70 is The orifice space 132 is not in communication. As a result, the main liquid chamber 42 and the sub liquid chamber 44 communicate with each other only through the shake orifice 122.

  In the vibration isolator 10, as shown in FIG. 1, when the plunger member 78 moves (rises) to the open position, the plunger member 78 is separated from the orifice opening 74, the orifice opening 74 is opened, and the common orifice portion 70 is opened. The orifice space 132 is in communication. As a result, the main liquid chamber 42 and the sub liquid chamber 44 communicate with each other through both the shake orifice 122 and the idle orifice 124. However, when the liquid pressure in the main liquid chamber 42 changes, When the liquid that has flowed into the common orifice portion 70 reaches the vicinity of the boundary with the dedicated orifice portion 72, the liquid preferentially enters the orifice space 132 through the orifice opening 74 having a smaller flow resistance than the dedicated orifice portion 72. In addition, the liquid flowing into the common orifice part 70 through the orifice opening 74 preferentially passes through the common orifice part 70 whose liquid flow resistance is smaller than that of the dedicated orifice part 72 and into the main liquid chamber 42. Exit. Thereby, in the vibration isolator 10, when the plunger member 78 is in the open position, the liquid flows between the main liquid chamber 42 and the sub liquid chamber 44 substantially only through the idle orifice 124.

  As shown in FIG. 3, the plunger member 78 is formed with a plurality of (two in the present embodiment) hydraulic pressure release passages 126 penetrating in the axial direction at the radial intermediate portion thereof. These hydraulic pressure release paths 126 allow the liquid in the hydraulic pressure space 130 closed from the outside to flow into the orifice space 132 when the plunger member 78 in the closed position moves to the open position side by the urging force of the coil spring 90. The plunger member 78 can be moved to the open position side by preventing the hydraulic pressure in the hydraulic pressure space 130 from rising.

(Operation of the embodiment)
Next, the operation of the vibration isolator 10 according to the 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 24 via the mounting bracket 20, and the rubber elastic body 24 is elastically deformed. At this time, the rubber elastic body 24 acts as a main vibration absorber, and the vibration is absorbed by the vibration absorbing action based on the internal friction or the like of the rubber elastic body 24, so that the vibration transmitted to the vehicle body side via the outer cylinder fitting 12 is reduced. . 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.

  Further, in the vibration isolator 10, a part of the shake orifice 122 on the main liquid chamber 42 side is the common orifice part 70 that forms a part of the idle orifice 124, and the sub-liquid chamber in the common orifice part 70 and the shake orifice 122. Since the orifice opening 74 communicating with the orifice space 132 of the cylinder chamber 76 is formed between the dedicated orifice portion 72 which is a part on the side of the cylinder 44, the main liquid chamber 42 and the sub liquid chamber 44 are used as the common orifice portion. 70 and a shake orifice 122 including a dedicated orifice portion 72 and communicate with each other via an idle orifice 124 including a common orifice portion 70 and an orifice space 132.

  Further, in the vibration isolator 10, when the plunger member 78 moves from the open position to the closed position against the urging force of the coil spring 90 by the hydraulic pressure in the hydraulic space 130 of the cylinder chamber 76, the orifice opening 74 is closed. When the coil spring 90 returns to the open position from the closed position due to the urging force, the orifice opening 74 is opened, so that the plunger member 78 in the open position passes through the check valve 128 from the main fluid chamber 42 into the hydraulic pressure space 130. When the liquid is supplied to the closed position, the liquid moves back and forth between the main liquid chamber 42 and the sub liquid chamber 44 only through the shake orifice 122 with the elastic deformation of the rubber elastic body 24. When the plunger member 78 in the closed position returns to the open position by the biasing force of the coil spring 90, the shake orifice 122 and Both of the idle orifices 124 are opened, but with the elastic deformation of the rubber elastic body, the main liquid chamber 42 and the auxiliary liquid chamber preferentially pass through the idle orifice 124 with a relatively small flow resistance of the liquid. Liquid goes back and forth between 44 and 44.

  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 24 is elastically deformed by the shake vibration, and a relatively large liquid is contained in the main liquid chamber 42. As the pressure changes, the liquid flows from the main fluid chamber 42 into the hydraulic pressure space 130 through the check valve 128 when the hydraulic pressure in the main fluid chamber 42 periodically increases, and the hydraulic pressure in the hydraulic pressure space 130 is also main. The pressure in the liquid chamber 42 rises to an equilibrium pressure that is substantially in equilibrium with the rising liquid pressure.

  Here, in the vibration isolator 10, the urging force of the coil spring 90 is set to be smaller than the value corresponding to the hydraulic pressure (equilibrium pressure) in the hydraulic pressure space 130 when the shake vibration is input. When vibration is input, the plunger member 78 moves intermittently from the open position to the closed position against the biasing force of the coil spring, and is held at the closed position by the hydraulic pressure in the hydraulic pressure space 130.

  Therefore, in the vibration isolator 10, when shake vibration is input, the liquid moves back and forth between the main liquid chamber 42 and the sub liquid chamber 44 only through the shake orifice 122 in accordance with the elastic deformation of the rubber elastic body 24. Since the input vibration (shake vibration) can be absorbed, the low-frequency vibration transmitted from the engine side to the vehicle body side in the vehicle can be reduced.

  At this time, the flow resistance of the liquid in the shake orifice 122 is set (tuned) so as to correspond to the frequency and amplitude of the shake vibration, so that the main liquid chamber 42 and the sub liquid chamber 44 pass through the shake orifice 122. 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 24 is elastically deformed by the idle vibration and a relatively small liquid is contained in the main liquid chamber 42. In this case as well, since the pressure changes, the liquid flows from the main fluid chamber 42 into the hydraulic pressure space through the check valve 128 when the hydraulic pressure in the main fluid chamber 42 periodically rises. Of the main liquid chamber 42 reaches an equilibrium pressure that is substantially in equilibrium with the hydraulic pressure (maximum value) at the time of ascent in the main liquid chamber 42.

  However, in the vibration isolator 10, the urging force of the coil spring 90 is set to be larger than the value corresponding to the equilibrium pressure in the hydraulic pressure space 130 at the time of input of idle vibration, whereby the plunger member 78 is opened. When the coil spring 90 is in the closed position, the coil spring 90 is held at the open position. When the coil spring 90 is in the closed position, the coil spring 90 is moved (returned) from the closed position to the open position.

  When the plunger member 78 in the closed position moves to the open position side by the urging force of the coil spring 90, the hydraulic pressure release path 126 formed in the plunger member 78 is closed from the outside in the hydraulic pressure space 130. Since the liquid inside flows out into the orifice space 132, the hydraulic pressure in the hydraulic space 130 is prevented from rising, and the plunger member 78 can be moved smoothly toward the open position with low movement resistance.

  Therefore, in the vibration isolator 10, when the idle vibration is input, the main liquid chamber 42 preferentially passes through the idle orifice 124 having a small liquid flow resistance with respect to the shake orifice 122 in accordance with the elastic deformation of the rubber elastic body 24. Since the liquid moves between the secondary liquid chamber 44 and the auxiliary liquid chamber 44, the input vibration (idle vibration) can be absorbed, so that the 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 124 is set (tuned) so as to correspond to the frequency and amplitude of the idle vibration, the main liquid chamber 42 and the sub liquid chamber 44 pass through the idle orifice 124. 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 42 and the sub liquid chamber 44 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 122 or the idle orifice 124 according to the frequency of the input vibration, using the change in the hydraulic pressure in the main liquid chamber 42 as the driving force.

  In the vibration isolator 10, the check valve 128 divides the valve body storage chamber 114 provided between the main liquid chamber 42 and the hydraulic pressure space 130, and the main liquid chamber 42 and the valve body storage chamber 114. A partition-like valve seat portion 148, valve seat openings 96 and 104 provided in the valve seat portion 148 for communicating the main liquid chamber 42 and the valve body storage chamber 114 with each other, and a valve seat in the valve body storage chamber 114 It is arranged so as to be movable along the axial direction that is in contact with and away from the portion 148, and opens and closes the valve seat openings 96 and 104 in contact with and away from the valve seat portion 148 according to the change in the hydraulic pressure in the main fluid chamber 42. When the hydraulic pressure in the main liquid chamber 42 rises with respect to the hydraulic pressure in the sub-liquid chamber 44, the hydraulic pressure in the main liquid chamber 42 (positive pressure) is provided. ), The valve body 102 is separated from the valve seat portion 148 in the valve body storage chamber 114 and the valve seat openings 96 and 104 are opened. Therefore, the pressurized liquid flows from the main liquid chamber 42 into the sub liquid chamber 44 through the valve seat openings 96 and 104, and the liquid pressure in the main liquid chamber 42 corresponds to the liquid pressure in the sub liquid chamber 44. When the pressure drops, the valve body 102 comes into close contact with the valve seat surface 156 of the valve seat portion 148 in the valve body storage chamber 114 by the action of the liquid pressure (negative pressure) in the main liquid chamber 42, thereby opening the valve seat openings 96, 104. As a result, the liquid flow between the main liquid chamber 42 and the sub liquid chamber 44 through the valve seat openings 96 and 104 is blocked.

  Therefore, when vibration is input to the outer cylinder fitting 12 or the mounting fitting 20 and the fluid pressure in the main fluid chamber 42 is periodically changed, when the fluid pressure in the main fluid chamber 42 increases with respect to the fluid pressure in the sub fluid chamber 44. Only when the pressurized liquid flows from the main liquid chamber into the sub liquid chamber through the valve seat openings 96 and 104 and the liquid pressure in the main liquid chamber 42 decreases, the liquid is added from the sub liquid chamber 44 to the main liquid chamber 42. Since the liquid in the pressurized state can be prevented from flowing out (leaking), the liquid pressure in the hydraulic pressure space 130 is increased by the pressurized liquid flowing in through the valve seat openings 96 and 104 to increase in the main liquid chamber 42. It can be controlled to an equilibrium pressure that is substantially balanced with the fluid pressure (maximum value) at the time.

  Further, in the vibration isolator 10, the disc-like valve body 102 is disposed in the valve body storage chamber 114 so as to be movable along the axial direction in which the valve seat portion 148 contacts and separates from the valve seat surface 156. As a result, even if the valve body 102 is not elastically deformed, the valve seat openings 96 and 104 can be opened and closed by bringing the valve body 102 into and out of contact with the valve seat portion 148 in accordance with the fluid pressure change in the main fluid chamber 42. Therefore, for example, the rigidity of the valve body 102 is sufficiently higher than the hydraulic pressure in the main liquid chamber 42 as compared with the conventional vibration isolator in which the valve body is formed of a rubber material and bends and deforms when the valve seat opening is opened. Since it can be made high, it is possible to prevent the valve body 102 from being deteriorated and damaged over time.

  As a result, according to the vibration isolator 10 according to the present embodiment, the operation of the check valve 128 can be effectively prevented from becoming unstable due to deterioration or damage of the valve body 102. It becomes unstable for a long time that the response speed when switching the device mode (shake mode and idle mode) decreases and the plunger member 78 cannot move normally to the position corresponding to the frequency of the input vibration. Can be prevented.

  In the vibration isolator 10, a rubber seat surface sheet 150 is attached to the lower surface side of the top plate portion 92, and the lower surface portion of the seat surface sheet 150 serves as the valve seat surface 156 of the valve seat portion 148. Since the seat sheet 150 has a buffering action against an impact, it is effective to generate a hitting sound when the valve body 102 comes into contact with (collises with) the valve seat surface 156 due to the negative pressure in the main liquid chamber 42. Since the sealing performance in a state where the valve body 102 is in close contact with the valve seat surface 156 can be improved, liquid leakage from the sub liquid chamber 44 into the main liquid chamber 42 can be effectively prevented.

  In the vibration isolator 10 according to the present embodiment, the valve body 102 disposed in the valve body storage chamber 114 moves to a position where the valve seat openings 96 and 104 are opened or closed using the hydraulic pressure as a driving force. For example, when the amplitude of the input vibration is small, the valve body 102 cannot be completely brought into close contact with the valve seat surface 156, and the valve seat 102 can be opened by the valve body 102 even when the hydraulic pressure in the main fluid chamber 42 decreases. May not be completely closed, and liquid leakage may occur from the secondary liquid chamber 44 into the main liquid chamber 42.

  Therefore, as shown in FIG. 8, as a valve body urging means, a coil spring 160 is inserted in a compressed state between the valve body 102 and the bottom plate portion 105 of the holder member 100 on the outer peripheral side of the guide rod 158. The valve body 102 may be pressed against the valve seat surface 156 by the urging force of the coil spring 160. Thereby, when the liquid pressure in the main liquid chamber 42 is lowered, the valve seat opening 104 can be reliably closed by the valve body 102, and liquid leakage from the sub liquid chamber 44 into the main liquid chamber 42 can be prevented. Here, the valve body urging means is not limited to the coil spring 160, and for example, an elastic body such as rubber or a leaf spring may be used.

  In the vibration isolator 10, one of the two orifices (the first restriction passage and the second restriction passage) is a shake orifice 122 corresponding to shake vibration, and the other is an idle orifice 124 corresponding to idle vibration. The two first restricting passages and the second restricting passage need not necessarily correspond to shake vibration and idle vibration, and the first restricting passage corresponds to vibration in a relatively low frequency range. It suffices if the two restriction paths correspond to vibrations in a relatively high frequency range.

  Further, in the vibration isolator 10, the mounting bracket 20 is connected to the engine side and the outer cylinder bracket 12 is connected to the vehicle body side. On the contrary, the mounting bracket 20 is connected to the vehicle body side. The outer cylinder fitting 12 may be connected to the engine side.

  Further, in the vibration isolator 10 according to the present embodiment, liquid is supplied from the main fluid chamber 42 into the hydraulic space 130 through the check valve 128 when the hydraulic pressure in the main fluid chamber 42 increases, The hydraulic pressure is increased to an equilibrium pressure corresponding to the upper limit value of the hydraulic pressure in the main fluid chamber 42, and 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 when a shake vibration is input. However, on the contrary, the check valve is configured so that the liquid can flow only from the hydraulic space 130 to the main liquid chamber 42, and this check valve is used when the hydraulic pressure in the main liquid chamber 42 is reduced. By letting the liquid flow out from the hydraulic pressure space 130 into the main fluid chamber 42 through the valve, the hydraulic pressure in the hydraulic pressure space 130 is lowered to an equilibrium pressure corresponding to the lower limit value of the hydraulic pressure in the main fluid chamber 42, and shake vibration is generated. At the time of input, the plunger is driven by the hydraulic pressure (negative pressure) of the hydraulic pressure space 130. 78 may be so moved from the open position to the closed position.

It is sectional drawing along the axial direction which shows the structure of the vibration isolator which concerns on 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 a perspective view which shows the structure of the orifice member in the vibration isolator shown by FIG. (A) And (B) is a perspective view which shows the structure of the holder member and valve body in the vibration isolator shown in FIG. 1, respectively. It is sectional drawing which shows the structure of the partition metal fitting and plunger member at the time of arrange | positioning a coil spring between the valve body and holder member in the vibration isolator shown in FIG.

Explanation of symbols

10 Anti-vibration device 12 Outer cylinder fitting (first mounting member)
20 Mounting bracket (second mounting member)
24 Rubber elastic body (elastic body)
36 Partition bracket (support member)
40 Diaphragm 42 Main liquid chamber 44 Sub liquid chamber 70 Common orifice portion 72 Dedicated orifice portion 74 Orifice opening 76 Cylinder chamber 78 Plunger member 90 Coil spring (biasing member)
102 Valve body 122 Shake orifice (first restriction passage)
124 Idle orifice (second restricted passage)
126 Hydraulic pressure release path 128 Check valve 130 Hydraulic pressure space 132 Orifice space 150 Seat surface seat (valve seat surface)
156 Valve seat surface 160 Coil spring (valve body biasing member) 1

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 filled with 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 capable of moving between a predetermined open position and a closed position along the expansion / contraction direction of the hydraulic pressure space;
The orifice space is provided so as to face the orifice space, and the orifice space in the second restriction passage communicates with another portion. When the plunger member is in the open position, the plunger member is opened. An orifice opening that is closed when moved to the closed position;
The reverse is arranged between the main liquid chamber and the hydraulic pressure space and allows the liquid to flow only in one direction between the main liquid chamber and the hydraulic pressure space as the hydraulic pressure in the main liquid chamber changes. A stop valve,
A biasing member that biases the plunger member toward the open position that reduces the hydraulic pressure space; and
The check valve includes a valve body storage chamber provided between the main liquid chamber and the hydraulic space, a partition-shaped valve seat section that partitions the main liquid chamber and the valve body storage chamber, A valve seat opening provided in the valve seat portion for communicating the main liquid chamber and the valve body storage chamber with each other, and moved along an opening / closing direction in which the valve seat portion is brought into contact with and separated from the valve seat portion A plate-shaped valve body that is arranged so as to be capable of opening and closing the valve seat opening in contact with and away from the valve seat portion in accordance with a change in hydraulic pressure in the main liquid chamber. Shaker.   The rigidity of the valve body is set so that a substantially undeformed state is maintained along the bending direction even when the hydraulic pressure in the main liquid chamber is received when the hydraulic pressure in the main liquid chamber changes. The vibration isolator according to claim 1.   The vibration isolator according to claim 1 or 2, wherein the valve body is formed of a resin material or a metal material.   The vibration isolator according to any one of claims 1 to 3, wherein a valve seat surface with which the valve body comes into contact with and separates from the valve seat portion when the hydraulic pressure in the main fluid chamber changes is formed of an elastic material. . Forming a guide hole penetrating in the opening and closing direction in the center of the valve body,
5. The guide shaft according to claim 1, further comprising a guide shaft that extends in the opening / closing direction in the valve body storage chamber and is slidably inserted into the guide hole. Anti-vibration device.   The vibration isolator according to any one of claims 1 to 5, further comprising a valve body biasing member that biases the valve body toward the valve seat.

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