JP2007120567A - Vibration isolator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the degree-of-freedom of design for a first limiting passage and a second limiting passage by restricting an increase in the dimension of a device. <P>SOLUTION: In a vibration isolator 10, a groove 64 is formed on the outer peripheral surface of an orifice member 46 forming part of a partitioning fitting 36. A shake orifice 122 is formed by blocking the outer peripheral side of the groove 64 with an outer cylinder fitting 12. An orifice passage 152 which is part of an idle orifice 124 is formed between an auxiliary orifice member 140 and the orifice member 46 by fitting the auxiliary orifice member 140 into the inner peripheral side of the orifice member 46. Thereby, the shake orifice 122 having a high communication resistance of the fluid can be formed in an arbitrary range on the outer peripheral surface of the orifice member 46. The orifice passage 152 of an idle orifice 124 having a low communication resistance of the fluid can be formed between the auxiliary orifice member 140 fitted into the inner peripheral side of the orifice member 46 and the orifice member 46. <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 partition member that forms a part of the inner wall surface of the main liquid chamber and a part of the inner wall surface of the auxiliary liquid chamber is fitted on the inner peripheral side of the outer cylinder, and the partition member Has two grooves with different lengths and cross-sectional areas. These two groove portions are closed on the outer peripheral side by the inner peripheral surface of the outer cylinder to form a part of an idle orifice and a shake orifice.
International Publication WO 2004/081408

  However, in the vibration isolator of Patent Document 1, in order to increase the vibration absorption effect due to liquid column resonance, the length of the shake orifice should be sufficiently long, or the cross-sectional area of the idle orifice should be sufficiently large. In order to satisfy such a requirement, it may be necessary to enlarge the dimension (height) or outer diameter along the axial direction of the partition member.

  Therefore, in the vibration isolator of Patent Document 1, when the shake orifice or the idle orifice is designed with priority given to the vibration absorption effect, the partition member becomes large and the size of the device is enlarged, and the size reduction of the device is prioritized. If the dimension of the partition member is limited, the degree of freedom in designing the shake orifice or the idle orifice is lowered, and the vibration absorption effect due to the liquid column resonance may be insufficient.

  In view of the above facts, an object of the present invention is to provide a vibration isolator capable of increasing the degree of freedom in designing the first restricting passage and the second restricting passage while suppressing an increase in the size of the device. .

  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, The main liquid chamber whose internal volume changes with elastic deformation of the elastic body, the sub liquid chamber in which liquid is sealed and the internal volume can be expanded and contracted, and the main liquid chamber and the sub liquid chamber 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 liquid flow resistance smaller than that of the first restriction passage, the main liquid chamber and the sub liquid chamber. A substantially cylindrical shape provided between the liquid chamber and forming a part of the inner wall surface of the main liquid chamber and the inner wall surface of the sub liquid chamber. A cutting member, a cylinder chamber provided on the inner peripheral side of the partition member, and an orifice that forms a part of the second restriction passage and communicates with the sub liquid chamber in the cylinder chamber and filled with the liquid The space is partitioned into a hydraulic space isolated from the second restriction passage, and is movable between a predetermined open position and a closed position along the expansion / contraction direction of the orifice space and the hydraulic space. The plunger member is provided so as to face the orifice space, communicates the orifice space and the other part of the second restriction passage, and is opened when the plunger member is in the open position. An orifice opening that is closed when the member moves to the closed position, and the main liquid chamber and the hydraulic pressure space are disposed between the main liquid chamber and the hydraulic pressure as the hydraulic pressure changes in the main liquid chamber. space A non-return valve that can circulate liquid only in one direction, and a biasing member that biases the plunger member toward the open position that reduces the hydraulic pressure space, and the partition member The first restriction passage is provided along the outer peripheral surface of the partition member, an auxiliary orifice member is disposed between the inner peripheral surface of the partition member and the cylinder chamber, and the auxiliary orifice member serves as at least a part of the partition wall. As described above, another portion of the second restriction passage is provided.

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

  In the vibration isolator according to the first aspect, basically, when vibration is transmitted to one of the first and second mounting members, the elastic body disposed between the first and second mounting members is The elastic deformation causes the vibration to be absorbed by the vibration absorbing action based on the internal friction 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 through the, the input vibration (high frequency vibration) can be absorbed by the viscous resistance and pressure loss of the liquid flowing through the second restriction passage. High frequency vibrations transmitted from the vibration generating unit to the vibration receiving unit can be effectively 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 frequency and amplitude of the high-frequency vibration, the main liquid chamber and the sub liquid chamber pass through the second restriction passage. Since a resonance phenomenon (liquid column resonance) occurs in the liquid flowing back and forth, the high frequency region vibration can be particularly effectively absorbed by the action of the liquid column resonance.

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

  In the vibration isolator according to the first aspect, the first restriction passage is provided along the outer peripheral surface of the partition member, and the auxiliary orifice member is disposed between the inner peripheral surface of the partition member and the cylinder chamber. By providing another part of the second restriction passage so that the orifice member is at least a part of the partition wall, the first liquid flow resistance is relatively large along an arbitrary region on the outer peripheral surface of the partition member. The second restriction passage having a relatively small liquid flow resistance so that the auxiliary orifice member disposed on the inner peripheral side of the partition member is at least a part of the partition wall. Since the portion can be provided, the other part of the first restriction passage and the second restriction passage can be arranged at different positions along the radial direction, and one of the first restriction passage and the second restriction passage can be provided. Other installation space It can be prevented from interfering with the installation space.

  As a result, according to the vibration isolator according to claim 1, the height and the outer diameter of the partition member are compared with the conventional vibration isolator in which two restriction passages are provided along the outer peripheral surface of the partition member. The length of the first restricting passage can be increased while the cross-sectional area of the second restricting passage can be enlarged, and the first restricting passage and the second restricting passage can be suppressed while suppressing an increase in the size of the apparatus. The degree of freedom of design for both of the restricted passages can be increased.

  The vibration isolator according to claim 2 of the present invention is the vibration isolator according to claim 1, wherein the auxiliary orifice member is provided with a cylindrical portion having an outer diameter smaller than the inner diameter of the partition member, and the partition member The other part of the second restriction passage is disposed between the inner peripheral surface of the cylindrical portion and the outer peripheral surface of the cylindrical portion.

  The vibration isolator according to claim 3 of the present invention is the vibration isolator according to claim 2, characterized in that a space formed on the inner peripheral side of the auxiliary orifice member is the cylinder chamber.

  According to a fourth aspect of the present invention, there is provided a vibration isolator comprising: a first attachment member connected to one of the vibration generator and the vibration receiver; and a second attachment connected to the other of the vibration generator and the vibration receiver. An attachment member, an elastic body disposed between the first attachment member and the second attachment member, and a liquid is sealed with the elastic body as a part of a partition wall, and accompanying elastic deformation of the elastic body A main liquid chamber in which the internal volume changes, a sub liquid chamber in which liquid is sealed and the internal volume can be expanded and contracted, and a first restriction passage that communicates the main liquid chamber and the sub liquid chamber with each other; The main liquid chamber and the sub liquid chamber communicate with each other, and are provided between the main liquid chamber and the sub liquid chamber, a second restricting path having a liquid flow resistance smaller than that of the first restricting path. A substantially cylindrical partition member that respectively forms an inner wall surface of the main liquid chamber and a part of an inner wall surface of the sub liquid chamber, and the partition portion A cylinder chamber filled with liquid, an orifice space that forms part of the second restriction passage and communicates with the sub-liquid chamber, and the second restriction. A plunger member that is partitioned into a hydraulic space isolated from the passage and is movable between a predetermined open position and a closed position along a direction of expansion and contraction of the orifice space and the hydraulic space; and the orifice space The orifice space is provided so as to face inward and communicates with the orifice space in the second restriction passage and the other portion, and is opened when the plunger member is in the open position, and the plunger member moves to the closed position. Then, the orifice opening which is closed is disposed between the main liquid chamber and the hydraulic pressure space, and is unidirectional between the main liquid chamber and the hydraulic pressure space as the hydraulic pressure changes in the main liquid chamber. Liquid only And a biasing member for biasing the plunger member toward the open position for reducing the hydraulic pressure space, and the first member along the outer peripheral surface of the partition member. The check valve and the plunger member are respectively formed in an annular shape, and the other part of the second limit passage passes through the inner peripheral side of the check valve and the plunger member. It is provided.

  The operation of the vibration isolator according to claim 4 of the present invention will be described below.

  According to the vibration isolator according to claim 4, similarly to the vibration isolator according to claim 1, without using a valve mechanism that operates by receiving external control and power supply such as an electromagnetic solenoid or a pneumatic solenoid. In response to a change in the frequency of the input vibration, the restriction passage communicating the main liquid chamber and the sub liquid chamber is driven to one of the first restriction passage and the second restriction passage to drive the change in the fluid pressure in the main liquid chamber. It can be switched using as force.

  In the vibration isolator according to claim 4, the first restricting passage is provided along the outer peripheral surface of the partition member, and the check valve and the plunger member are each formed in an annular shape, and the second restricting passage is provided. Is provided so as to penetrate the inner peripheral side of the check valve and the plunger member, so that the first restriction passage having a relatively large liquid flow resistance along an arbitrary region in the entire outer peripheral surface of the partition member. And the other part of the second restricting passage having a relatively small flow resistance of the liquid can be provided on the inner peripheral side of the check valve and the plunger member formed in an annular shape. The other restriction passages and the second restriction passage can be disposed at different positions along the radial direction, and one installation space of the first restriction passage and the second restriction passage interferes with the other installation space. Can prevent .

  As a result, according to the vibration isolator according to claim 4, the height and outer diameter of the partition member are compared with the conventional vibration isolator in which two restriction passages are provided along the outer peripheral surface of the partition member. The length of the first restriction passage can be made sufficiently long and the cross-sectional area of the second restriction passage can be set to a desired cross-sectional area while suppressing the increase in the size of the device. The degree of freedom in design for both the first restriction passage and the second restriction passage can be increased.

  A vibration isolator according to claim 5 of the present invention is the vibration isolator according to claim 4, wherein a guide hole penetrating in the expansion / contraction direction is formed in a central portion of the plunger member and integrated with the check valve. And a through hole that extends in the expansion / contraction direction in the cylinder chamber and is provided so as to be slidably inserted into the guide, and penetrates the check valve and the guide shaft in the expansion / contraction direction. And the through hole is formed as another part of the second restriction passage.

  The vibration isolator according to claim 6 of the present invention is the vibration isolator according to claim 5, wherein the orifice opening is provided between a lower end portion of the guide shaft and a bottom surface portion of the cylinder chamber. And

  As described above, according to the vibration isolator of the present invention, it is possible to increase the degree of design freedom for the first restricting passage and the second restricting passage while suppressing an increase in the size of the device.

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

(First embodiment)
1 and 2 show a vibration isolator according to a first embodiment of the present invention. 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. 4, 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 with a bottomed cylindrical shape 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 a plurality of (for example, six) circulation openings 52 are formed in the bottom plate portion 50 in a circular shape. In addition, as shown in FIG. 3, a thick cylindrical boss portion 54 is integrally formed on the inner peripheral side of the flow opening 52.

  As shown in FIG. 3, the dimension along the axial direction of the boss portion 54 is larger than the thickness of the bottom plate portion 50, and protrudes from the lower surface side 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. Further, on the upper surface side of the bottom plate portion 50, a plunger insertion / removal portion 59 is formed in a concave shape on the outer peripheral side of the boss portion 54 so as to extend over the entire circumference in the circumferential direction.

  As shown in FIG. 4, 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 fitting insertion portion 60 and the lower end portion on the outer peripheral surface. The orifice member 46 is formed with a concave communication passage 66 extending in the axial direction at the upper end of the outer peripheral surface thereof. The communication passage 66 is formed in the main liquid chamber 42 along the longitudinal direction of the groove 64. One end portion on the side communicates with the upper surface portion of the orifice member 46. In addition, the orifice member 46 is formed with a communicating path 68 penetrating in the axial direction at the lower end portion of the outer peripheral surface thereof. The communicating path 68 has the other end portion along the longitudinal direction of the groove portion 64 at the other end of the orifice member 46. It communicates to the lower surface.

  Here, in the groove portion 64, the width along the axial direction and the depth along the radial direction of the portion extending in the spiral direction excluding the communication passage 66 and the communication passage 68 are substantially constant at an arbitrary portion. The cross-sectional area along the direction perpendicular to the longitudinal direction of the groove portion 64 is set so as to correspond to the frequency (for example, (for example, 9 to 15 Hz) and amplitude of the shake vibration generated when the vehicle travels.

  As shown in FIG. 4, a cylindrical space is formed on the inner peripheral side of the orifice member 46, and this cylindrical space is an internal compartment in which an auxiliary orifice member 140 and a plunger member 78, which will be described later, are respectively housed. 70. The auxiliary orifice member 140 is formed in a substantially thin cylindrical shape, and the auxiliary orifice member 140 is formed with a flange-like partition portion 142 extending to the outer peripheral side at the upper end portion thereof, and at the outer periphery of the partition portion 142. A support portion 144 extending downward from the end is bent. Here, the length of the auxiliary orifice member 140 along the axial direction is shorter than the depth of the internal compartment 70 by a predetermined length.

  On the other hand, an annular stepped portion 146 is formed on the inner peripheral surface of the orifice member 46 at its axially intermediate portion. The inner diameter of the orifice member 46 is such that the upper inner diameter is lower than the lower inner diameter via the stepped portion 146. Has been expanded. The inner diameter on the upper side with respect to the stepped portion 146 is slightly larger than the outer diameter of the support portion 144 in the auxiliary orifice member 140.

  As shown in FIG. 4, the auxiliary orifice member 140 has a plurality of (three in the present embodiment) lower communication ports 148 that are slit-like in the circumferential direction in the partition portion 142. In addition, between the pair of lower communication ports 148, the support portion 144 and the partition portion 142 are each cut out in a rectangular shape to form the lower cutout portion 150. The three lower communication ports 148 and the lower cutouts 150 are arranged at an equal pitch (90 ° pitch) along the circumferential direction around the axis S. The lower notch 150 is arranged so that the outer peripheral side thereof faces the communication path 66 of the orifice member 46.

  In the partition metal fitting 36, the auxiliary orifice member 140 is fitted on the inner peripheral side of the orifice member 46. At this time, the auxiliary orifice member 140 abuts the lower end portion of the support portion 144 against the stepped portion 146 and brings the outer peripheral surface of the support portion 144 into contact with the inner peripheral surface of the orifice member 46 (internal compartment 70). At this time, a gap having a predetermined width is formed between the lower end portion of the auxiliary orifice member 140 and the bottom plate portion 50 of the orifice member 46, and this gap is an orifice that allows an idle orifice 124 and a cylinder chamber 76 to be described later to communicate with each other. The opening 74 is used (see FIG. 3).

  In the partition metal fitting 36, the auxiliary orifice member 140 is fitted and inserted into the inner peripheral side thereof, so that the inner compartment 70 is formed by the auxiliary orifice member 140 in the radial direction along the radial direction as shown in FIG. And a cylindrical space on the inner peripheral side. Here, the space on the outer peripheral side through the auxiliary orifice member 140 is an orifice passage 152 constituting a part of an idle orifice 124 described later, and the space on the inner peripheral side is a cylinder chamber 76 that houses the plunger member 78. Is done.

  As shown in FIG. 4, the plunger member 78 is formed in a substantially thick disk shape, and the hydraulic space 130 (FIG. 2) 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. 3), which is a small space on the side of the auxiliary liquid chamber 44. As shown in FIG. 3, the plunger member 78 has a thick cylindrical shape whose upper surface is closed by a thick disk-shaped top plate portion 79 and extends downward from the outer peripheral end of the top plate portion 79. The peripheral wall 80 is formed in a substantially bottomed cylindrical shape integrally formed. Here, the lower end portion of the peripheral wall portion 80 is a seal portion 81 that can be inserted into and removed from the plunger insertion / removal portion 59 of the orifice member 46, and the lower end surface of the seal portion 81 is planar. At the same time, the outer diameter of the outer peripheral surface is slightly smaller than the inner diameter of the plunger insertion / removal portion 59 on the outer peripheral side.

  The plunger member 78 is integrally formed with a thick cylindrical guide tube portion 82 projecting downward from the lower surface central portion of the top plate portion 79 and penetrates the central portion of the guide tube portion 82 in the axial direction. A bearing hole 84 is formed. 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 auxiliary orifice member 140 (cylinder chamber 76). It becomes. 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 upper end surface of the coil spring 90 is brought into pressure contact with the peripheral edge portion of the seat receiving projection 86 of the plunger member 78, and the lower end surface is brought into pressure contact with the bottom surface portion of the seat receiving hole 56, so that the plunger member 78 and the bottom plate portion 50 are pressed. Is always kept in a compressed state. Thereby, the coil spring 90 always biases the plunger member 78 upward (to the main liquid chamber 42 side).

  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. 4, the lid member 48 has a circular fitting insertion hole 94 formed in the center portion of the top plate portion 92, and a plurality of fan-shaped holes formed on the outer peripheral side of the fitting 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.

  As shown in FIG. 4, the lid member 48 has a plurality of (three in the present embodiment) upper communication ports 154 that are elongated in the circumferential direction on the outer peripheral side of the valve seat opening 96. In addition, a rectangular upper notch 156 is formed on the outer peripheral side of one upper communication port 154. The four upper communication ports 154 are arranged at an equal pitch (90 ° pitch) along the circumferential direction around the axis S, and the three lower communication ports 148 and the lower side of the auxiliary orifice member 140 are arranged. It arrange | positions so that it may each face in the inner peripheral side of the notch part 150, respectively. The upper notch 156 is disposed so as to face the outer peripheral side of the lower notch 150 in the auxiliary orifice member 140.

  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.

  As shown in FIG. 4, the holder member 100 is formed with a plurality of communication openings 108 each formed in a fan shape on the outer peripheral portion of the bottom plate portion 105 of the valve element holder 104. In addition, a plurality of (four in this embodiment) intermediate communication ports 158 that are slits elongated in the circumferential direction are formed in the flange portion 106 of the holder member 100, and one intermediate communication port 158. A rectangular intermediate cutout portion 160 is formed on the outer peripheral side of each of the two. The four intermediate communication ports 158 are arranged at an equal pitch (90 ° pitch) along the circumferential direction around the axis S, and the three lower communication ports 148 and the lower side of the auxiliary orifice member 140 are arranged. The notches 150 are arranged so as to face each other on the inner peripheral side of the notch 150 and to face the four upper communication ports 154 in the lid member 48.

  As a result, the orifice passage 152 passes through the lower communication port 148 and the lower notch 150 of the auxiliary orifice member 140, the intermediate communication port 158 of the holder member 100, and the upper communication port 154 of the lid member 48. It communicates with the liquid chamber 42. One end portion of the groove portion 64 of the orifice member 46 passes through the communication passage 66, the outer peripheral side of the lower notch portion 150 of the auxiliary orifice member 140, the intermediate notch portion 160 of the holder member 100, and the upper notch portion 156 of the lid member 48. It communicates with the chamber 42.

  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. 4) 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 reaches the tip end side near or at the lower end of the orifice member 46 through 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. As described above, one end of the shake orifice 122 serving as the first restriction passage is connected to the main liquid chamber 42 through the communication passage 66, the outer peripheral side of the lower notch 150, the intermediate notch 160, and the upper notch 156. Communication,
The other end communicates with the auxiliary liquid chamber 44 through the communication path 68.

  Here, the shake orifice 122 is constituted by the entire groove portion 64. 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 orifice passage 152 forms a part of an idle orifice 124 corresponding to idle vibration (for example, 18 to 30 Hz) that is vibration in a high frequency range relative to shake vibration. The idle orifice 124, which is the second restriction passage, is composed of an orifice passage 152 and an orifice space 132, and is set (tuned) so that its path length and cross-sectional area, that is, the flow resistance of the liquid corresponds to idle vibration. Has been. 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 seal portion 81 of the plunger member 78 is inserted into the plunger insertion / removal portion 59 of the orifice member 46 to assist The orifice opening 74 of the orifice member 140 is closed by the outer peripheral surface of the plunger member 78, and the orifice passage 152 is not in communication with the orifice space 132. 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 seal portion 81 of the plunger member 78 moves away from the plunger insertion / removal portion 59 and the orifice opening 74 is opened. The orifice passage 152 is in communication with the orifice space 132. 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, the main liquid chamber 42 and the sub liquid chamber 44 are more influential than the shake orifice 122. The liquid flows between the main liquid chamber 42 and the sub liquid chamber 44 through the idle orifice 124 having a small flow resistance of the liquid. Therefore, 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 hydraulic pressure release passage 126 penetrating in the axial direction at a radially intermediate portion of the top plate portion 79. The hydraulic pressure release path 126 allows the liquid in the hydraulic pressure space 130 closed from the outside to enter 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 is allowed to move to the open position side by preventing the fluid pressure from rising in the fluid pressure space 130.

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

  In the vibration isolator 10, for example, when an engine in a vehicle is operated, vibration generated by the engine is transmitted to the rubber elastic body 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.

  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 returning from the closed position to the open position by the biasing force of the coil spring 90, the orifice opening 74 is opened, so that the plunger member 78 in the open position passes from the main liquid chamber 42 into the hydraulic pressure space 130 through the check valve 128. When moved to the closing position by the supplied hydraulic pressure, the liquid moves back and forth between the main liquid chamber 42 and the sub liquid chamber 44 through only the shake orifice 122 with the elastic deformation of the rubber elastic body 24, and is also blocked. When the plunger member 78 at the position returns to the open position by the biasing force of the coil spring 90, the shake orifice 122 and the arm Both of the dollar orifices 124 are opened, but with the elastic deformation of the rubber elastic body 24, the main liquid chamber 42 and the secondary liquid are preferentially passed through the idle orifice 124 having a relatively small liquid flow resistance. Liquid goes back and forth between the chambers 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 shake vibration transmitted from the engine side to the vehicle body side in the vehicle can be reduced.

  At this time, since 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 in the low frequency range vibration, it passes through the shake orifice 122 and the main liquid chamber 42. A resonance phenomenon (liquid column resonance) occurs in the liquid flowing back and forth between the sub liquid chambers 44, 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 vibrations among high frequency vibrations can be particularly effectively absorbed 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 groove portion 64 is formed on the outer peripheral surface of the orifice member 46 constituting a part of the partition metal 36, and the outer periphery of the groove portion 64 is closed by the outer cylindrical metal member 12 to provide a shake orifice 122. By inserting the auxiliary orifice member 140 on the inner peripheral side of the orifice member 46 and providing the orifice passage 152 which is a part of the idle orifice 124 between the auxiliary orifice member 140 and the orifice member 46, A shake orifice 122 having a relatively large liquid flow resistance can be provided in an arbitrary region on the outer peripheral surface, and between the auxiliary orifice member 140 and the orifice member 46 fitted on the inner peripheral side of the orifice member 46. Orifice passage 15 of idle orifice 124 with relatively small liquid flow resistance Therefore, the shake orifice 122 and the orifice passage 152 can be arranged at different positions along the radial direction in the apparatus, and one of the idle orifices 124 constituted by the shake orifice 122, the orifice passage 152 and the orifice space 132 can be provided. Can effectively prevent the other installation space from interfering with the other installation space.

  As a result, according to the vibration isolator 10, compared to the conventional vibration isolator in which two shake orifices and a part of the idle orifice are provided along the outer peripheral surface of the orifice member 46, the orifice member 46 (partition While the expansion of the height and outer diameter of the metal fitting 36) is suppressed, the path length of the shake orifice 122 is made sufficiently long so that the liquid column resonance with respect to the shake vibration can be effectively obtained, and the cross-sectional area of the idle orifice 124 and Since the length can be set to a desired cross-sectional area so that liquid column resonance with respect to idle vibration can be effectively obtained, the degree of freedom of design for both the shake orifice 122 and the idle orifice 124 can be increased while suppressing increase in the size of the apparatus. Can be high.

(Second Embodiment)
5 and 6 show a vibration isolator according to a second embodiment of the present invention. In the vibration isolator 210 according to the present embodiment, the same reference numerals are given to the same parts as those of the vibration isolator 10 according to the first embodiment, and the description thereof is omitted.

  In the vibration isolator 210, as in the case of the vibration isolator 10 according to the first embodiment, a partition metal fitting 236 (see FIG. 7) formed in a substantially thick disk shape as a whole on the inner peripheral side of the outer tube metal fitting 12. ) Is inserted. In the vibration isolator 210, the configuration of the other parts excluding the partition fitting 236 is basically the same as that of the vibration isolator 10 according to the first embodiment.

  As shown in FIG. 8, the partition member 236 is provided with a bottomed cylindrical lid member 248 on the upper side of the orifice member 246. The orifice member 246 is formed in a thick bottomed cylindrical shape whose bottom surface is closed by the bottom plate portion 250, and a plurality of (for example, six) flow openings 252 are formed in the bottom plate portion 250 in a circular shape. In addition, as shown in FIG. 7, a thick cylindrical boss 254 is integrally formed on the inner peripheral side of the flow opening 252.

  As shown in FIG. 7, the boss portion 254 has a dimension along the axial direction larger than the thickness of the bottom plate portion 250 and protrudes from the lower surface side of the bottom plate portion 250. The boss portion 254 is formed with a concave seat receiving groove 256 extending in the circumferential direction at the center of the upper surface, and a lower end portion of a coil spring 90 described later is inserted into the seat receiving groove 256. The bottom plate portion 250 is formed with a circular convex blocking portion 258 on the inner peripheral side of the seat receiving groove 256. As shown in FIG. 8, the orifice member 246 is formed with a fitting insertion portion 260 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 246 has a concave groove portion 64 extending along a spiral direction inclined at a predetermined angle with respect to the circumferential direction between the fitting insertion portion 260 and the lower end portion on the outer peripheral surface.

  As shown in FIG. 8, a cylindrical space is formed on the inner peripheral side of the orifice member 246, and this cylindrical space is a cylinder chamber 276 in which a plunger member 278 described later is accommodated. The plunger member 278 is formed in a thick disk shape, and as shown in FIG. 7, a hydraulic space 130 (see FIG. 6) is a small space on the main liquid chamber 42 side along the axial direction of the cylinder chamber 276. ) And an orifice space 132 which is a small space on the side of the auxiliary liquid chamber 44. As shown in FIG. 7, the plunger member 278 is closed at its upper surface by a thick disc-shaped top plate portion 279 and has a thick cylindrical shape that extends downward from the outer peripheral end of the top plate portion 279. The peripheral wall portion 280 is formed in a substantially bottomed cylindrical shape integrally formed.

  As shown in FIG. 7, the plunger member 278 is integrally formed with a thick cylindrical guide tube portion 282 that protrudes downward from the center of the lower surface of the top plate portion 279. A bearing hole 284 that penetrates the central portion in the axial direction is formed. The inner diameter of the bearing hole 284 is slightly larger than the outer diameter of the closing portion 258 of the orifice member 246. The plunger member 278 is inserted into the cylinder chamber 276 of the orifice member 246 and is movable (slidable) in the axial direction along the inner peripheral surface of the cylinder chamber 276.

  At this time, the plunger member 278 is movable between a predetermined closed position and an open position along the axial direction. When the plunger member 278 is in the open position shown in FIG. The lower end portion of 282 is held above the bottom plate portion 250, and an annular gap is formed between the lower end portion of the guide tube portion 282 and the bottom plate portion 250. When the plunger member 278 moves (lowers) from the open position to the closed position shown in FIG. 6, the closed portion 258 of the orifice member 246 is inserted into the bearing hole 284, and the bearing hole 284 is liquid-tight by the closed portion 258. It is blocked to become.

  As shown in FIG. 7, a coil spring 90 is disposed on the partition member 236 between the bottom plate portion 250 of the orifice member 246 and the plunger member 278. The upper end side of the coil spring 90 is fitted on the outer peripheral side of the guide tube portion 282 of the plunger member 278 and the lower end portion thereof is inserted into the seat receiving groove 256 of the orifice member 246. In this state, the upper end surface of the coil spring 90 is pressed against the peripheral edge of the guide tube portion 282 of the plunger member 78, and the lower end surface is pressed against the bottom surface portion of the seat receiving groove 256, so that the plunger member 278 and the bottom plate portion 250 are pressed. Is always kept in a compressed state. As a result, the coil spring 90 always urges the plunger member 278 upward (open position side).

  As shown in FIG. 7, in the partition member 236, the lid member 248 is fitted and fixed on the outer peripheral side of the fitting insertion portion 260 in the orifice member 246. As a result, the upper end side of the cylinder chamber 276 of the orifice member 246 is closed by the top plate portion 292 of the lid member 248. As shown in FIG. 8, the lid member 248 has a circular insertion hole 294 formed in the center of the top plate portion 292, and a plurality of fan-shaped holes formed on the outer peripheral side of the insertion hole 294. In this embodiment, four valve seat openings 296 are formed. These valve seat openings 296 are arranged so as to have a symmetrical positional relationship (point symmetry) about the axis S. The lid member 248 has a notch 298 formed on the outer periphery thereof so as to face the communication path 266 on the upper end side of the orifice member 246.

  As shown in FIG. The partition member 236 has a substantially disc-shaped holder member 300 disposed between the lid member 248 and the plunger member 278, and a substantially disc-shaped valve body between the holder member 300 and the lid member 248. 302 is interposed. As shown in FIG. 7, the holder member 300 is formed with a valve body holder 304 having a shallow bottomed cylindrical shape at the center, and from the upper end portion of the valve body holder 304 to the outer peripheral side. An extending annular flange portion 306 is bent. The holder member 300 is formed with a plurality of communication openings 308 each formed in a fan shape on the outer peripheral portion of the bottom plate portion 305 of the valve body holder 304.

  The holder member 300 has a notch 307 formed by cutting the outer periphery of the flange 306 into a rectangular shape. The notch 307 is disposed so as to face the notch 298 of the lid member 248 and the communication path 266 of the orifice member 246, respectively. Accordingly, the communication path 266 of the groove 64 communicates with the main liquid chamber 42 through the notch 307 and the notch 298.

  As shown in FIG. 7, the holder member 300 is integrally formed with a cylindrical guide rod 320 that protrudes downward along the axis S from the center of the lower surface of the bottom plate portion 305. The guide rod 320 is formed with a cylindrical hollow portion 321 penetrating in the axial direction on the inner peripheral side thereof. Here, between the top plate portion 292 of the lid member 248 and the bottom plate portion 305 of the holder member 300, a valve body storage chamber 314 that is a disk-shaped space having a substantially constant thickness along the axial direction is formed. The valve body 302 is stored in the valve body storage chamber 314. Further, in the partition fitting 236, an annular gap having a predetermined width is formed along the axial direction between the lower end portion of the guide rod 320 and the bottom plate portion 250 of the orifice member 246, and this annular gap is an orifice described later. An orifice opening 274 that communicates the passage 340 and the orifice space 132 is formed.

  The valve body 302 is molded from a rubber composition such as NR, NBR, etc., and the upper surface side is flat, 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 302 is formed with a circular convex protrusion 116 at the center of the upper surface, and a hollow portion 318 penetrating in the axial direction at the center. The hollow portion 318 has an inner diameter equal to that of the hollow portion 321 of the guide rod 320, and constitutes one orifice passage 340 together with the hollow portion 321. The orifice passage 340 has an upper end opening into the main liquid chamber 42 and a lower end communicating with the orifice space 132 through the orifice opening 274.

  The valve body 302 has its protrusion 316 inserted into the insertion hole 294 of the lid member 248. Thereby, the valve body 302 is positioned coaxially with the holder member 300 and the lid member 248, and the movement in the radial direction is restricted. Further, the valve body 302 is compressed along the axial direction between the top plate portion 292 of the lid member 248 and the bottom plate portion 305 of the holder member 300 in the vicinity of the peripheral portion of the protrusion 316. As a result, the upper surface portion of the valve body 302 is brought into pressure contact with the top plate portion 292 of the lid member 248 with a predetermined pressure (pre-pressure), and the axial movement between the lid member 248 and the holder member 300 is performed. Be bound. In the valve body 302, a portion on the outer peripheral side of the compressed portion can be bent and deformed downward.

  As shown in FIG. 7, the valve body 302 has its outer peripheral end positioned on the outer peripheral side with respect to the outer peripheral end of the valve seat opening 296 in the lid member 248 along the radial direction, and of the communication opening 308 of the holder member 300. It is located on the inner peripheral side with respect to the outer peripheral end. As a result, the valve body 302 closes the valve seat opening 96 with its upper surface pressed against the top plate portion 292 (closed state), and the outer peripheral side is downward as shown by a two-dot chain line in FIG. The valve seat opening 296 communicates with the communication opening 308 via the valve body storage chamber 314, and the main liquid chamber 42 is in the valve body storage chamber. 314 communicates with the cylinder chamber 276 in the partition member 236. That is, the valve body 302, the lid member 248, and the holder member 300 housed in the valve body housing chamber 314 constitute a check valve 328 (see FIG. 8) between the main liquid chamber 42 and the cylinder chamber 276. The check valve 328 allows the liquid to flow only from the main liquid chamber 42 into the cylinder chamber 276 (hydraulic pressure space 130), but prevents the liquid from flowing from the hydraulic pressure space 130 into the main liquid chamber 42. Stop.

  The guide rod 320 of the holder member 300 is inserted into the bearing hole 284 of the plunger member 278 so as to be relatively slidable along the axial direction. Here, when one of the guide tube portion 282 and the guide rod 320 in which the bearing hole 284 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. In addition, one or both of the inner peripheral surface of the bearing hole 284 and the outer peripheral surface of the guide rod 320 may be coated with a material having lubricity and high wear resistance to suppress frictional resistance.

  The orifice space 132 of the cylinder chamber 276 always communicates with the sub liquid chamber 44 through the plurality of flow openings 252 of the orifice member 246. Further, in the vibration isolator 210, as shown in FIG. 5, the outer peripheral side of the groove portion 64 in the orifice member 246 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. The shake orifice 122 serving as the first restriction passage has one end connected to the main liquid chamber 42 and the other end connected to the sub liquid chamber 44.

  The orifice passage 340 formed by the hollow portion 318 of the valve body 302 and the hollow portion 321 of the plunger member 278 corresponds to idle vibration (for example, 18 to 30 Hz) which is vibration in a high frequency range relative to the shake vibration. A part of the idle orifice 324 is formed. The idle orifice 324, which is the second restriction passage, is constituted by the orifice opening 274 and the orifice space 132 in the orifice member 246, and its path length and cross-sectional area, that is, the flow resistance of the liquid corresponds to idle vibration. Is set (tuned). Here, the flow resistance of the liquid in the idle orifice 324 is smaller than the flow resistance of the liquid in the shake orifice 122.

  In the vibration isolator 210, as shown in FIG. 6, when the plunger member 278 moves (lowers) to the closed position, the orifice opening 274 of the orifice member 246 is closed by the guide tube portion 282 and the closed portion 258, and the orifice passage 340. Is not in communication with the orifice space 132. 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 210, as shown in FIG. 5, when the plunger member 278 moves (rises) to the open position, the guide cylinder portion 282 of the plunger member 278 opens the orifice opening 274 from the closed portion 258 of the orifice member 246. Then, the orifice passage 340 is in communication with the orifice space 132. 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 324. However, when the liquid pressure in the main liquid chamber 42 changes, the main liquid chamber 42 and the sub liquid chamber 44 are more than the shake orifice 122. The liquid flows between the main liquid chamber 42 and the sub liquid chamber 44 through the idle orifice 324 having a low flow resistance of the liquid. Therefore, in the vibration isolator 210, when the plunger member 278 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 324.

  As shown in FIG. 7, the plunger member 278 is formed with a hydraulic pressure release passage 326 that penetrates the top plate portion 279 in the axial direction. These hydraulic pressure release passages 326 allow the liquid in the hydraulic pressure space 130 closed from the outside to flow into the orifice space 132 when the plunger member 278 in the closed position moves to the open position side by the urging force of the coil spring 90. The plunger member 278 can be moved to the open position side by preventing the hydraulic pressure in the hydraulic space 130 from increasing.

  Next, the operation of the vibration isolator 210 according to the embodiment of the present invention will be described.

  In the vibration isolator 210, 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.

  In the vibration isolator 210, when the plunger member 278 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 276, the orifice opening 274 is closed, When returning from the closed position to the open position by the biasing force of the coil spring 90, the orifice opening 274 is opened, so that the plunger member 278 in the open position passes from the main liquid chamber 42 into the hydraulic pressure space 130 through the check valve 328. When moved to the closing position by the supplied hydraulic pressure, the liquid moves back and forth between the main liquid chamber 42 and the sub liquid chamber 44 through only the shake orifice 122 with the elastic deformation of the rubber elastic body 24, and is also blocked. When the plunger member 278 located at the position returns to the open position by the biasing force of the coil spring 90, the shake orifice 122 and the idle orifice 324 are both opened. However, with the elastic deformation of the rubber elastic body, the main fluid chamber 42 and the auxiliary fluid 42 are preferentially passed through the idle orifice 324 having a relatively small liquid flow resistance. Liquid moves back and forth between the liquid chambers 44.

  That is, in the vibration isolator 210, 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 to the hydraulic pressure space 130 through the check valve 328 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 210, the biasing 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 278 moves intermittently from the open position to the closed position against the biasing force of the coil spring 90 and is held at the closed position by the hydraulic pressure in the hydraulic pressure space 130.

  Therefore, in the vibration isolator 210, 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 shake 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.

  Further, in the vibration isolator 210, when an 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 into the hydraulic pressure space from the main hydraulic chamber 42 through the check valve 328 when the hydraulic pressure in the main hydraulic chamber 42 rises periodically, and the hydraulic pressure space 130 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 210, 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 278 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 278 in the closed position moves to the open position side due to the urging force of the coil spring 90, the hydraulic pressure release path 326 formed in the plunger member 278 is closed from the outside in the hydraulic pressure space 130. Since the liquid inside flows out into the orifice space 132, the fluid pressure in the fluid pressure space 130 is prevented from rising, and the plunger member 278 can be moved smoothly toward the open position with low movement resistance.

  Therefore, in the vibration isolator 210, when the idle vibration is input, the main liquid chamber 42 preferentially passes through the idle orifice 324 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 324 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 324. 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 210, 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 one of the shake orifice 122 and the idle orifice 324 as a driving force according to the frequency of the input vibration.

  Further, in the vibration isolator 210, a groove portion 64 is formed on the outer peripheral surface of the orifice member 246 constituting a part of the partition fitting 236, and the outer peripheral side of the groove portion 64 is closed by the outer cylindrical fitting 12 to provide the shake orifice 122. The lid member 248, the valve body 302 and the holder member 300, and the plunger member 278 constituting the check valve 328 are respectively formed in an annular shape, and the orifice passage 340 of the idle orifice 324 is formed on the inner periphery of the check valve 328 and the plunger member 278. By providing so as to penetrate the side, the shake orifice 122 having a relatively large liquid flow resistance can be provided in an arbitrary region on the outer peripheral surface of the orifice member 246, and a check valve formed in an annular shape 328 and the plunger member 278 are arranged on the inner peripheral side of the orifice through which the liquid flow resistance is relatively small. 340, the orifice passages 340 of the shake orifice 122 and the idle orifice 324 can be arranged at different positions along the radial direction inside the apparatus, and the installation space of one of the shake orifice 122 and the idle orifice 324 is the other. Interference with the installation space can be prevented.

  As a result, according to the vibration isolator 210, the orifice member 246 (partition) is compared with the conventional vibration isolator in which two shake orifices and part of the idle orifice are provided along the outer peripheral surface of the orifice member 246. While the expansion of the height and outer diameter of the metal fitting 236) is suppressed, the path length of the shake orifice 122 is made sufficiently long so that the liquid column resonance with respect to the shake vibration can be effectively obtained, and the cross-sectional area of the idle orifice 324 is increased. Since a desired cross-sectional area and length can be set so that liquid column resonance with respect to idle vibration can be effectively obtained, design freedom for both the shake orifice 122 and the idle orifice 324 can be increased while suppressing an increase in the size of the apparatus. Can be high.

  In the vibration isolators 10 and 210 according to the first and second embodiments of the present invention, one of the two orifices (the first restriction passage and the second restriction passage) is a shake orifice corresponding to shake vibration. 122, and the other is the idle orifices 124 and 324 corresponding to idle vibration. However, the two first restriction passages and the second restriction passage do not necessarily correspond to the shake vibration and the idle vibration. The restriction path may correspond to vibrations in a relatively low frequency range, and the second restriction path may correspond to vibrations in a relatively high frequency range.

  Further, in the vibration isolator 10, 210, the mounting bracket 20 is connected to the engine side, and the outer cylinder bracket 12 is connected to the vehicle body side. Conversely, the mounting bracket 20 is connected to the vehicle body side. In addition, the outer cylinder fitting 12 may be connected to the engine side.

  Further, in the vibration isolator 10, 210 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, and this hydraulic space 130 is supplied. The fluid pressure in the fluid pressure chamber 130 is increased to an equilibrium pressure corresponding to the fluid pressure upper limit value of the main fluid chamber 42, and when the shake vibration is input, the plunger member 78 is moved from the open position to the closed position by the fluid pressure (positive pressure) in the fluid pressure space 130. Contrary to this, the check valve is configured so that the liquid can flow out only from the hydraulic pressure space 130 to the main fluid chamber 42, and when the hydraulic pressure in the main fluid chamber 42 decreases, By causing the liquid to flow out from the hydraulic pressure space 130 into the main fluid chamber 42 through the check valve, the hydraulic pressure in the hydraulic pressure space 130 is reduced to an equilibrium pressure corresponding to the lower limit value of the hydraulic pressure in the main fluid chamber 42, When vibration is input, the pressure is reduced by the hydraulic pressure (negative pressure) in the hydraulic pressure space 130. The Ja member 78 from the open position may be be moved to the closed position.

It is sectional drawing along the axial direction which shows the structure of the vibration isolator which concerns on the 1st Embodiment of this invention, and has shown the state which has a plunger member in an open position. It is sectional drawing along the axial direction which shows the structure of the vibration isolator shown by FIG. 1, and has shown the state which has a plunger main body in the obstruction | occlusion position. It is sectional drawing which shows the structure of the partition metal fitting and plunger member in the vibration isolator shown by FIG. It is a disassembled perspective view which shows the structure of the partition metal fitting and plunger member in the vibration isolator shown by FIG. It is sectional drawing along the axial direction which shows the structure of the vibration isolator which concerns on the 2nd Embodiment of this invention, and has shown the state which has a plunger member in an open position. It is sectional drawing along the axial direction which shows the structure of the vibration isolator shown by FIG. 5, 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. 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.

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 (partition member)
42 Main liquid chamber 44 Sub liquid chamber 46 Orifice member (partition member)
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 space 132 Orifice space 140 Auxiliary orifice member 152 Orifice passage (idle orifice)
210 Vibration isolator 236 Partition bracket (partition member)
246 Orifice member (partition member)
258 Blocking portion 274 Orifice opening 276 Cylinder chamber 278 Plunger member 302 Valve body 324 Idle orifice 326 Hydraulic pressure release path 328 Check valve 340 Orifice passage (idle orifice)

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 sub-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 substantially cylindrical partition member provided between the main liquid chamber and the sub liquid chamber, each of which forms a part of the inner wall surface of the main liquid chamber and the inner wall surface of the sub liquid chamber;
A cylinder chamber provided on the inner peripheral side of the partition member 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, communicates the orifice space with the other portion in the second restriction passage, is opened when the plunger member is in the open position, and the plunger member is closed. An orifice opening that is closed when moved into 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 first restriction passage is provided along the outer peripheral surface of the partition member, an auxiliary orifice member is disposed between the inner peripheral surface of the partition member and the cylinder chamber, and the auxiliary orifice member is disposed at least one of the partition walls. An anti-vibration device characterized in that another part of the second restriction passage is provided so as to be a part.   The auxiliary orifice member is provided with a cylindrical portion having an outer diameter smaller than the inner diameter of the partition member, and the second restriction passage is provided between the inner peripheral surface of the partition member and the outer peripheral surface of the cylindrical portion. The anti-vibration device according to claim 1, wherein the portion is arranged.   The vibration isolator according to claim 2, wherein a space formed on an inner peripheral side of the auxiliary orifice member is the cylinder chamber. 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 sub-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 substantially cylindrical partition member provided between the main liquid chamber and the sub liquid chamber, each of which forms a part of the inner wall surface of the main liquid chamber and the inner wall surface of the sub liquid chamber;
A cylinder chamber provided on the inner peripheral side of the partition member 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, communicates the orifice space with the other portion in the second restriction passage, is opened when the plunger member is in the open position, and the plunger member is closed. An orifice opening that is closed when moved into 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;
The first restriction passage is provided along the outer peripheral surface of the partition member, the check valve and the plunger member are each formed in an annular shape, and the other part of the second restriction passage is the check valve and A vibration isolator provided so as to penetrate the inner peripheral side of the plunger member. A guide hole penetrating in the expansion / contraction direction is formed in the central portion of the plunger member, and extends in the expansion / contraction direction integrally with the check valve in the cylinder chamber, and can slide relative to the guide. Provide a guide shaft to be inserted into
5. The anti-vibration device according to claim 4, wherein a through hole penetrating in the expansion / contraction direction is formed in the check valve and the guide shaft, and the through hole is configured as another part of the second restriction passage. apparatus.   6. The vibration isolator according to claim 5, wherein the orifice opening is provided between a lower end portion of the guide shaft and a bottom surface portion of the cylinder chamber.

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