JP2007071317A - Vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately position a seat winding part of a coil spring, urging a plunger member to an open position side of an orifice opening, to a predetermined assembly position, and surely prevent the coil spring from moving along a direction perpendicular to an axis. <P>SOLUTION: In a vibration isolator 10, a seat receiving projection 86 formed on a lower surface side of a plunger member 78 is fitted in an upper end part inner circumference side of the coil spring 90 and a lower end part of the coil spring 90 is fitted in a seat receiving hole 56 formed on an upper surface side of a bottom plate part 50 of an orifice member 46. Consequently, an upper seat winding part 140 and a lower seat winding part 136 of the coil spring 90 can be accurately positioned on the assembly position concentrically with an axial center S by the seat receiving projection 86 and the seat receiving hole 56 respectively. Even if the coil spring 90 repeats deformation in a compression and extension direction and generates lateral force at a time of vibration input, it can be prevented that whole body of the coil spring 90 moves in the direction perpendicular to the axis and displaces from the assembly position. <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.

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.
International Publication WO 2004/081408

  In the vibration isolator described in Patent Document 1, the coil spring that biases the plunger member to the open position is placed in a compressed state in the orifice space, and this coil spring has one end winding portion (seat surface). ) Is brought into pressure contact with the plunger member, and the other end winding portion (seat surface) is brought into pressure contact with the partition wall partitioning the orifice space and the auxiliary liquid chamber in the apparatus.

  By the way, it is known that the coil spring normally has a pair of end winding portions each having an asymmetric shape with respect to the axial center, so that a lateral force along the direction perpendicular to the axis is generated during deformation. For this reason, in the vibration isolator as in Patent Document 1, when the coil spring repeatedly deforms in the compression and pulling directions at the time of vibration input, the entire coil spring moves along the radial direction due to the influence of lateral force, Misalignment (eccentricity) occurs with respect to a predetermined assembly position, or one end winding part moves relative to the other end winding part along the direction perpendicular to the axis, and the coil spring moves in the opening / closing direction of the plunger member. There is a possibility of tilting. When the coil spring is thus eccentric or tilted, in the vibration isolator as in Patent Document 1, the relationship between the amount of deformation of the coil spring and the restoring force (spring constant) becomes different from the design value. Alternatively, since the non-linear characteristic of the coil spring becomes strong, there is a possibility that the plunger member does not normally move to a position (open position or closed position) corresponding to the frequency of the input vibration.

  In view of the above fact, the object of the present invention is to accurately position the coil winding end portion of the coil spring for urging the plunger member toward the opening position of the orifice opening at a predetermined assembly position, and to install the coil spring. An object of the present invention is to provide a vibration isolator capable of reliably preventing displacement from a position.

  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 a closed position, an orifice opening provided to face the orifice space, and communicating the orifice space with another portion in the second restriction passage; A check that is arranged between the main fluid chamber and the hydraulic pressure space, and that allows liquid to flow out only in one direction between the main fluid chamber and the hydraulic pressure space as the hydraulic pressure in the main fluid chamber changes. A valve, a coil spring that urges the plunger member toward the open position that reduces the hydraulic space, and at least one end winding portion of the coil spring are engaged in a radial direction of the end winding portion. Move along And when the plunger member moves to the closed position against the urging force of the coil spring by the hydraulic pressure in the hydraulic space, the orifice opening is closed. The orifice opening is opened when the coil spring returns to the open position by the biasing force of the coil spring.

  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 the first aspect, the plunger member in the open position resists the biasing force of the coil spring to the closed position by the hydraulic pressure supplied from the main liquid chamber into the hydraulic pressure space through the check valve. Then, with the elastic deformation of the elastic body, 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 at the closed position is When the spring is returned to the open position by the urging force of the spring, both the first restriction passage and the second restriction passage are opened, but the flow resistance of the liquid is relatively increased due to the elastic deformation of the elastic body. The liquid moves back and forth between the main liquid chamber and the sub liquid chamber preferentially through the small second restriction 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 the liquid pressure in the hydraulic pressure space reaches an equilibrium pressure that is substantially balanced with the hydraulic pressure (maximum value or minimum value) at the time of change in the main liquid chamber. At this time, if the biasing force of the coil spring is set smaller than the value corresponding to the equilibrium pressure in the hydraulic pressure space, the plunger member intermittently moves from the open position to the closed position against the biasing force of the coil spring. To 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. In addition, since a relatively small hydraulic pressure change occurs in the main liquid chamber, the 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, or the hydraulic pressure space The liquid flows out from the main liquid chamber and reaches an equilibrium pressure at which the liquid pressure in the hydraulic space substantially equilibrates with the liquid pressure (maximum value or minimum value) in the main liquid chamber. At this time, if the biasing force of the coil spring 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, the coil spring is held in the open position by the biasing force, In the closed position, the coil spring is moved (returned) from the closed position to the open position by the biasing force of the coil spring.

  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 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. If this is the case, a resonance phenomenon (liquid column resonance) occurs in the liquid that passes between the main liquid chamber and the sub liquid chamber through the second restriction passage. Can be absorbed.

  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.

  Moreover, in the vibration isolator which concerns on Claim 1, it engages with the at least one end winding part in the coil spring which urges | biases a plunger member to the open position side, and restrict | limits the movement along the radial direction of this end winding part. By having the seat receiving portion, if the end winding portion of the coil spring is engaged with the seat receiving portion, the end winding portion can be accurately positioned so as to coincide with the seat receiving portion along the direction perpendicular to the axis, Since the seat receiving portion can prevent the end winding portion from moving along the direction perpendicular to the axis, if the seat receiving portion is installed at a predetermined assembly position, the coil spring is engaged with the seat receiving portion. The coil spring is displaced from the predetermined assembly position even when the coil spring is repeatedly deformed in the compression and tension directions when vibration is input, and the coil spring can be displaced from the predetermined assembly position. Possible to prevent the inclined relative to the expansion direction of the plunger member.

  The vibration isolator according to claim 2 of the present invention is the vibration isolator according to claim 1, wherein the seat receiving portion is formed in a protruding shape and includes the end winding portion of the coil spring. It is inserted and inserted into the inner peripheral side.

  The vibration isolator according to claim 3 of the present invention is the anti-vibration device according to claim 2, wherein the front end portion of the seat receiving portion is located on the inner peripheral side of the end winding portion. In addition, a taper portion whose outer diameter gradually decreases from the base end side to the tip end side of the seat receiving portion is formed.

  The vibration isolator according to claim 4 of the present invention is the vibration isolator according to claim 1, wherein the seat receiving portion is formed in a concave shape, and the end winding portion of the coil spring is provided on an inner peripheral side thereof. The strand part including is inserted, It is characterized by the above-mentioned.

  The vibration isolator according to claim 5 of the present invention is the vibration isolator according to claim 4, wherein the portion on the outlet side with respect to the back end located on the outer peripheral side of the end winding portion in the seat receiving portion In addition, a taper portion whose inner diameter gradually increases from the back side to the outlet side of the seat receiving portion is formed.

  The vibration isolator according to claim 6 of the present invention is the vibration isolator according to any one of claims 1 to 5, wherein the seat receiving portion faces the orifice space of the plunger member. It is arranged on the end face.

  The vibration isolator according to claim 7 of the present invention is the vibration isolator according to any one of claims 1 to 5, wherein the seat receiving portion partitions the orifice space and the sub liquid chamber. It is arranged in the part.

  As described above, according to the vibration isolator of the present invention, the end portion of the coil spring that urges the plunger member toward the opening position of the orifice opening can be accurately positioned at a predetermined assembly position, and the coil It is possible to reliably prevent the spring from moving along the direction perpendicular to the axis.

  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.

  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 cylinder fitting 12 so as to bend toward the outer peripheral side, and a caulking portion 16 is formed at the lower end portion that is 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 upper end side of the mounting bracket 20 is formed in a columnar shape having a substantially constant outer diameter, and the lower end side is formed in a substantially truncated cone shape whose outer diameter is reduced in a tapered shape downward. A screw hole 22 is drilled in the metal fitting 20 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 in the outer cylinder fitting 12. It is bent as follows. 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.

  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. 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.

  Here, as shown in FIG. 4, the inner diameter DI of the seat receiving hole 56 is longer than the outer diameter DT of the end winding portions 136 and 140 of the coil spring 90 by a predetermined length. Here, the inner peripheral surface of the seat receiving hole 56 is formed as a concave curved surface having a constant radius of curvature about the axis S. The edge portion 56E between the bottom surface portion and the inner peripheral surface of the seat receiving hole 56 is R-processed so as to be a concave curved surface. In addition, a planar region having a diameter corresponding to the outer diameter of the lower end winding portion 136 is formed on the bottom surface portion of the seat receiving hole 56 on the inner peripheral side of the edge portion 56E. As a result, a lateral force along the direction perpendicular to the axis is generated in the coil spring 90 compressed or tensile deformed, and even if this lateral force acts on the lower end winding portion 136, the lower end winding portion 136 moves in the direction perpendicular to the axis. Is prevented by the edge portion 56E, and even if the lower end winding portion 136 is slightly moved, the position is adjusted (self-aligned) to the original position (assembly position) by the reaction force from the edge portion 56E. .

  The seat receiving hole 56 has an inner diameter that is higher than the edge portion 56 </ b> E larger than the outer diameter of the coil spring 90. As a result, the outer peripheral side of the wire of the coil spring 90 is not in contact with the inner peripheral surface of the seat receiving hole 56, so that deformation near the lower end winding portion 136 of the coil spring 90 due to contact with the inner peripheral surface of the seat receiving hole 56 ( Compression and tensile deformation) is not hindered, and it is also possible to prevent frictional noise from coming into contact with the inner peripheral surface of the seat receiving hole 56 when the coil spring 90 is deformed.

  Further, the outer diameter DO of the seat receiving projection 86 is slightly shorter than the outer diameter DT of the end winding portions 136 and 140 of the coil spring 90, as shown in FIG. As a result, a lateral force along the direction perpendicular to the axis is generated in the coil spring 90 that is compressed or tensile deformed, and even if this lateral force acts on the upper end winding portion 140, the lower end winding portion 136 moves in the direction perpendicular to the axis. The movement is blocked by the seat receiving projection 86.

  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. As shown in FIG. 5, the lid member 48 has a circular insertion hole 94 formed in the center of the top plate portion 92, and a plurality of fan-shaped holes formed on the outer peripheral side of the insertion hole 94. In the present embodiment, four valve seat openings 96 are formed. These valve seat openings 96 are arranged so as to have a symmetrical positional relationship (point symmetry) about the axis S. Further, as shown in FIG. 5, the lid member 48 is formed with a notch 98 on its outer peripheral portion 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. The partition member 36 is provided with a substantially disc-shaped holder member 100 between the lid member 48 and the plunger member 78, and a substantially disc-shaped valve body between the holder member 100 and the lid member 48. 102 is interposed. 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. 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. A circular concave fitting insertion hole 112 is formed on the upper surface side of the boss portion 110. 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 valve body 102 is molded from a rubber composition such as NR, NBR, etc., and the upper surface side is formed into a flat shape, and the lower surface side is formed in a slope shape slightly inclined upward from the inner peripheral side to the outer peripheral side. The thickness along the axial direction gradually decreases from the inner peripheral side toward the outer peripheral side. The valve body 102 has a circular convex protrusion 116 formed at the center of the upper surface and a circular convex protrusion 118 formed at the center of the lower surface. The valve body 102 has a projection 116 on the upper surface side inserted into the insertion insertion hole 94 of the lid member 48, and a projection 118 on the lower surface side inserted into the insertion insertion hole 112 of the holder member 100. Thereby, the valve body 102 is positioned coaxially with the holder member 100 and the lid member 48, and the movement in the radial direction is restricted.

  The valve body 102 is compressed in the axial direction between the top plate portion 92 of the lid member 48 and the bottom plate portion 105 of the holder member 100 in the vicinity of the peripheral portions of the projections 116 and 118. As a result, the upper surface portion of the valve body 102 is pressed against the lower surface side of the top plate portion 92 of the lid member 48 with a predetermined pressure (preload), and between the lid member 48 and the holder member 100 in the axial direction. The movement of is restricted. In the valve body 102, a portion on the outer peripheral side of the compressed portion can be bent and deformed downward.

  As shown in FIG. 3, the valve body 102 has its outer peripheral end positioned radially outside the outer peripheral end of the valve seat opening 96 in the lid member 48 along the radial direction, and of the communication opening 108 of the holder member 100. It is located on the inner peripheral side with respect to the outer peripheral end. As a result, the valve body 102 closes the valve seat opening 96 in a state where the upper surface portion thereof is in pressure contact with the top plate portion 92 (closed state), and the outer peripheral side is downward as shown by a two-dot chain line in FIG. The valve seat opening 96 communicates with the communication opening 108 via the valve body storage chamber 114, and the main liquid chamber 42 is in the valve body storage chamber. 114 communicates with the cylinder chamber 76 in the partition metal 36. That is, 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 permits the inflow of liquid only from the main liquid chamber 42 into the cylinder chamber 76 (hydraulic pressure space 130), but prevents the liquid from flowing out from the hydraulic pressure space 130 into the main liquid chamber 42. Stop.

  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 other end portion is connected to the auxiliary liquid chamber 44 via the communication path 68 of the orifice member 46 while being connected to the main liquid chamber 42 via the notch 98 of the lid 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.

  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 vibration (shake vibration) can be absorbed by the viscous resistance, pressure loss, etc. of the liquid passing through the shake orifice 122, 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 flows back and forth between the gas and the auxiliary liquid chamber 44, the input vibration (idle vibration) can be absorbed by the viscous resistance and pressure loss of the liquid flowing through the idle orifice 124, so that the vibration is transmitted from the engine side to the vehicle body side. Can reduce idle vibration.

  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.

  Further, in the vibration isolator 10, a seat receiving projection 86 is formed on the lower surface side of the plunger member 78, and the seat receiving projection 86 is inserted into the inner peripheral side of the upper end portion including the upper end winding portion 140 in the coil spring 90. A seat receiving hole 56 is formed in a circular concave shape on the upper surface side of the bottom plate portion 50 of the orifice member 46, and the lower end portion including the lower end winding portion 136 of the coil spring 90 is inserted into the seat receiving hole 56. The upper end winding portion 140 and the lower end winding portion 136 of the coil spring 90 can be accurately positioned at the assembly position coaxial with the axis S by the seat receiving projection 86 and the seat receiving hole 56, respectively, and input of vibration Even when the coil spring 90 repeats deformation in the compression and pulling directions to generate lateral force, the entire coil spring 90 moves in the direction perpendicular to the axis and is displaced from the assembly position. Furthermore, one end winding portions 136 and 140 of the coil spring 90 are relatively displaced in the direction perpendicular to the axis with respect to the other end winding portions 136 and 140, and the coil spring 90 is inclined with respect to the axial direction. Can also be prevented.

  FIG. 7 shows a configuration of a partition fitting provided with modifications of seat receiving projections and seat receiving holes applicable to the vibration isolator according to the present embodiment.

  In the vibration isolator 10, when the coil spring 90 is used to bias the plunger member 78 toward the open position, the following problem may occur. That is, the coil spring 90 may be bent (meandered) at its central axis during compression deformation. The meandering of the coil spring 90 does not significantly affect the characteristics of the coil spring 90 itself, such as the spring constant, when the amount of meandering is within a predetermined range. Generally, the meandering amount of the coil spring 90 is within the predetermined range. Is used under the following conditions. However, when meandering occurs in the coil spring 90 and the upper end or lower end of the coil spring 90 is locally pressed against the outer peripheral surface of the seat receiving projection or the inner peripheral surface of the seat receiving hole, the upper end of the coil spring 90 is Smooth deformation of the portion and the lower end can be hindered, and can cause frictional noise.

  Therefore, the seat receiving projection 86 shown in FIG. 7 has a portion on the distal end side with respect to the base end portion 86S located on the inner peripheral side of the upper end winding portion 140 from the base end portion 86S to the distal end of the seat receiving projection 86. A tapered portion 86T whose outer diameter gradually decreases is formed. Thereby, between the inner peripheral end of the strand part which forms the upper end part of the coil spring 90, and the outer peripheral surface of the seat receiving projection 86, it extends along the radial direction from the base end portion 86S of the seat receiving projection 86 toward the distal end. Therefore, even when meandering occurs near the upper end of the coil spring 90, it is possible to effectively prevent the upper end of the coil spring 90 from coming into pressure contact with the outer peripheral surface of the seat receiving projection 86. it can.

  Further, in the seat receiving hole 56 shown in FIG. 7, the back end 56 </ b> S located on the outer peripheral side of the lower end winding portion 136 is located on the opening end side from the back end 56 </ b> S toward the opening end. A tapered portion 56T whose inner diameter gradually increases is formed. Thereby, between the outer peripheral end of the strand part which forms the lower end part of the coil spring 90, and the inner peripheral surface of the seat receiving hole 56, it is radial direction toward the opening end from the back | inner side edge part 54S of the seat receiving hole 56. Therefore, even when meandering occurs near the lower end of the coil spring 90, the lower end portion of the coil spring 90 is brought into pressure contact with the inner peripheral surface of the seat receiving projection 86. Can be prevented.

  In addition, in the vibration isolator 10 according to the present embodiment, the plunger member 78 is provided with the cylindrical seat receiving protrusion 86 and the orifice member 46 is provided with the circular concave seat receiving hole 56. The plunger member 78 is provided with a seat receiving hole, and the upper end portion of the coil spring is inserted into the seat receiving hole, and the orifice member 46 is provided with a seat receiving projection, and the seat receiving projection is formed at the lower end portion of the coil spring 90. You may make it insert. Further, either the seat receiving projection or the seat receiving hole may be provided on both the orifice member 46 and the plunger member 78.

  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, in contrast to this, the check valve is configured so that the liquid can flow only from the hydraulic pressure space 130 to the main liquid chamber 42, and when the hydraulic pressure in the main liquid chamber 42 decreases, the check valve The liquid is allowed to flow out from the hydraulic pressure space 130 into the main liquid chamber 42, thereby reducing the hydraulic pressure in the hydraulic pressure space 130 to an equilibrium pressure corresponding to the lower limit of the hydraulic pressure in the main liquid chamber 42, and inputting shake vibration. Sometimes, the plunger member 7 is caused by the hydraulic pressure (negative pressure) of the hydraulic space 130. The may be to move from an open position to a closed position.

  In the case described above, the vibration isolator 10 is configured such that the plunger member 78 is biased downward along the axial direction by the coil spring 90, and the orifice member 74 is in the lower limit position (open position). Is opened, and the orifice opening 74 is configured to be opened when it rises from the lower limit position to the upper limit position (closed position) against the biasing force of the coil spring 90 due to the negative pressure in the hydraulic pressure space 130. .

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. It is side surface sectional drawing which shows the structure of the partition metal fitting provided with the modification of the seat receiving protrusion and seat receiving hole which can be applied to 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 56 Seat receiving hole (seat receiving portion)
56T Taper part 70 Common orifice part 72 Dedicated orifice part 74 Orifice opening 76 Cylinder chamber 78 Plunger member 79 Edge part 86 Seat receiving projection (seat receiving part)
86T Taper 90 Coil spring 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

Claims (7)

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;
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,
A coil spring that biases the plunger member toward the open position that reduces the hydraulic pressure space;
A seat receiving portion that engages with at least one end winding portion of the coil spring and restricts movement of the end winding portion along the radial direction; and
When the plunger member moves to the closed position against the urging force of the coil spring by the hydraulic pressure in the hydraulic pressure space, the orifice opening is closed and the urging force of the coil spring moves to the open position. A vibration isolator that opens the orifice opening upon return.   The vibration isolator according to claim 1, wherein the seat receiving portion is formed in a protruding shape and is fitted and inserted into an inner peripheral side of the wire portion including the end winding portion in the coil spring.   A taper in which the outer diameter gradually decreases from the proximal end side to the distal end side of the seat receiving portion on the distal end side with respect to the proximal end portion located on the inner peripheral side of the end winding portion in the seat receiving portion. The vibration isolator according to claim 2, wherein a portion is formed.   The anti-vibration device according to claim 1, wherein the seat receiving portion is formed in a concave shape, and a wire portion including the end winding portion of the coil spring is fitted into the inner peripheral side thereof.   A taper portion whose inner diameter gradually increases from the back side of the seat receiving portion toward the outlet side at a portion on the outlet side with respect to the back side end portion located on the outer peripheral side of the end winding portion in the seat receiving portion. The anti-vibration device according to claim 4, wherein the anti-vibration device is formed.   The vibration isolator according to any one of claims 1 to 5, wherein the seat receiving portion is disposed on one end face of the plunger member facing the orifice space.   The vibration isolator according to any one of claims 1 to 5, wherein the seat receiving portion is disposed in a partition wall partitioning the orifice space and the sub liquid chamber.

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