JP2000145877A - Vibration isolating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a pair of differential aux. liquid chambers in an outer cylinder and form a stopper member to restrict the relative movement of an inner cylinder in a single piece with a resilient body or a reinforcing member of resilient body. SOLUTION: A vibration isolating device 10 is equipped with a rotary valve 78 to open either of two orifices 58 and 56. Differential aux. liquid chambers 27 and 28 are arranged opposed to a main liquid chamber 26 with a resilient body 24 interposed, and a diaphragm 30 to constitute part of the bulkhead for aux. liquid chambers 27 and 28 is coupled with an inner cylinder metal fitting 22 through the resilient body 24. Between the two chambers 27 and 28, a rebound stopper 41 is arranged integrally formed with an outer cylinder metal fitting 12 and the resilient body 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to general industrial machines, automobiles, and the like, and attenuates vibration generated from a vibration generator such as an engine, and suppresses vibration transmitted from the vibration generator to a vibration receiver. It relates to a vibration device.

[0002]

2. Description of the Related Art An anti-vibration device used as an engine mount for an automobile is provided with a differential sub-liquid chamber as a sub-liquid chamber communicating with a main liquid chamber through a restriction passage in order to improve an anti-vibration effect. There is. Such a vibration isolator, for example,
It is described in EP-A-0172700. In the vibration damping device described in this publication, the main liquid chamber has a part of the inner wall formed by the elastic body stretched between the outer cylinder and the inner cylinder, and the differential sub-liquid chamber has the inner cylinder interposed therebetween. It is arranged immediately above the main liquid chamber. The differential auxiliary liquid chamber has an upper surface portion of a thin elastic body covering the vicinity of an upper end portion of the inner cylinder, and a pair of diaphragms bridged between the upper surface portion of the elastic body and the inner peripheral surface of the outer cylinder. Is formed. Here, the diaphragm is formed integrally with the elastic body by a rubber film curved in a bellows shape, and the diaphragm is displaced in conjunction with the relative movement of the inner cylinder with respect to the outer cylinder, thereby causing a differential auxiliary. Increase or decrease the internal volume of the liquid chamber.

Therefore, according to the above-described vibration isolator, the elastic body is elastically deformed to expand or contract the internal volume of the main liquid chamber, and at the same time, the internal volume of the differential sub-liquid chamber is set in the opposite direction to the main liquid chamber. And the difference in internal pressure (fluid pressure) between the main fluid chamber and the differential sub-fluid chamber during vibration transmission can be increased. By generating column resonance, the vibration damping effect can be improved.

In the vibration isolator described in the above publication,
A truncated pyramid-shaped stopper (rebound stopper) is fixed to the inner peripheral side of the outer cylinder, and the rebound stopper is inserted into the differential sub-liquid chamber, and its front end surface is fixed to an inner cylinder covered with an elastic body. Are spaced apart from each other. Accordingly, even when a large force is transmitted to the inner cylinder from the outside, the upward movement of the inner cylinder is limited by the rebound stopper, so that the relative movement amount of the inner cylinder to the outer cylinder does not become excessive.

[0005]

However, in the vibration damping device described in European Patent Publication No. 0172700, it is necessary to arrange the differential sub liquid chamber directly above the main liquid chamber with the inner cylinder interposed therebetween. Such layout restrictions make it difficult to provide a plurality of differential sub-liquid chambers in the outer cylinder. Therefore, this vibration damping device is excellent in vibration damping effect for vibration in a specific narrow frequency range, but cannot effectively attenuate vibration over a wide frequency range.

In the vibration isolator described in the above publication,
Since the space formed between the pair of diaphragms formed integrally with the elastic body is a structure as a differential auxiliary liquid chamber,
The rebound stopper for restricting the relative movement of the inner cylinder cannot be formed integrally with the elastic body or the reinforcing member for reinforcing the elastic body. That is, for example, when an elastic body is molded, a pair of flange portions to which both ends of the elastic body in the axial direction are generally fixed, and an intermediate cylinder or the like including a connecting plate connecting the pair of flange portions are generally used. The reinforcing member is inserted into the mold, and the raw rubber is injected into the mold. In the finished product, a portion corresponding to the space between the pair of diaphragms serving as the differential auxiliary liquid chamber has a cavity protrusion of the mold. Is located, the rebound stopper disposed in the space between the diaphragms cannot be formed integrally with the elastic body or the reinforcing member.

In view of the above, the present invention has a pair of differential auxiliary liquid chambers, and a stopper member for limiting relative movement of the inner cylinder is formed integrally with the elastic member or the elastic member. It is an object of the present invention to provide a vibration isolator that can be used.

[0008]

According to a first aspect of the present invention, there is provided an anti-vibration device, wherein an outer cylinder connected to one of the vibration generating section and the vibration receiving section, and an outer cylinder connected to the other of the vibration generating section and the vibration receiving section; An inner cylinder arranged on the inner peripheral side of the outer cylinder, an elastic body arranged between the outer cylinder and the inner cylinder and connected to the outer cylinder and the inner cylinder, and at least a part of the inner wall has the elasticity. A main liquid chamber formed of a body, and in which a liquid is sealed, and at least a part of a partition wall that forms a sub liquid chamber while opposing the main liquid chamber with the elastic body interposed therebetween, is connected to the inner cylinder; An anti-vibration device comprising: a differential sub liquid chamber whose internal volume is expanded and contracted in accordance with relative displacement of an inner cylinder with respect to the outer cylinder; and a liquid passage connecting the differential sub liquid chamber to the main liquid chamber. In the outer cylinder, the pair of differential sub-liquid chambers are arranged so as to face each other along the circumferential direction of the inner cylinder. , Between the pair of differential auxiliary fluid chamber is to stopper member for limiting a relative movement with respect to the outer cylinder of the inner cylinder opposite the outer circumferential surface of the inner cylinder is provided.

According to the vibration damping device having the above-described structure, the pair of differential sub-liquid chambers are disposed in the outer cylinder so as to face each other along the circumferential direction of the inner cylinder. A stopper member that opposes the outer peripheral surface of the inner cylinder and restricts relative movement of the inner cylinder with respect to the outer cylinder is provided therebetween, so that the stopper member faces the main liquid chamber with the elastic body interposed therebetween, and at least a part of the partition Can be placed in the space that could not be used effectively in the outer cylinder with the conventional vibration isolator, so that the space in the outer cylinder could be used efficiently, A pair of differential sub-liquid chambers whose inner volumes respectively expand and contract in conjunction with the relative displacement of the inner cylinder can be easily arranged in the outer cylinder.

Further, since a space extending in the axial direction of the inner cylinder can be ensured between the pair of differential auxiliary liquid chambers, a stopper member for restricting relative movement of the inner cylinder can be easily arranged in this space. At this time, if the space formed between the pair of differential sub-liquid chambers is made to penetrate in the axial direction of the inner cylinder, when the elastic body is molded, the space between the pair of differential sub-liquid chambers in the mold is formed. Since the core set in the corresponding portion can be removed in the axial direction after the completion of the molding, the stopper member can be formed integrally with the elastic body or the reinforcing member of the elastic body.

According to a second aspect of the present invention, in the vibration isolator according to the first aspect, a pair of flange portions to which both ends of the elastic body in the axial direction are fixed, and the pair of flange portions are connected. And a reinforcing member comprising a connecting portion forming at least a part of the stopper member.

According to the vibration damping device having the above structure, at least a part of the stopper member is formed by the connecting portion connecting the pair of flange members of the reinforcing member, so that a part or all of the stopper member is formed by the reinforcing member. The number of parts and the number of assembling steps of the apparatus can be reduced.

Here, if the strength of the connecting portion is sufficiently high with respect to the load applied from the outside to the inner cylinder or the outer cylinder, the stopper member can be formed only by the connecting portion, and the strength is insufficient only by the connecting portion. In this case, the connecting member may be reinforced by another member, for example, a supporting portion formed as a part of the elastic body.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a vibration isolator according to an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 to 6 show a vibration isolator according to an embodiment of the present invention. The vibration isolator 10 is a so-called bush type vibration isolator, and is applied as an engine mount of a vehicle in the present embodiment. Incidentally, reference numeral axis S ₁ represents the axis of the inner sleeve 22, the axial center S
_The direction along ₁ is the axial direction of the device. Anti-vibration device 10
1 is provided with a cylindrical outer cylinder fitting 12 as shown in FIG. 1, and is connected to the vehicle body via a metal mounting frame (not shown) fixed onto the outer peripheral surface of the outer cylinder fitting 12. Is done. An intermediate block 14 and an intermediate cylinder 16 are arranged inside the outer cylinder fitting 12.

As shown in FIG. 7, the intermediate cylinder 16 includes a pair of flange portions 18, a pair of connecting plates 20, and a single stopper plate 21. The pair of flange portions 18 are each formed in a cylindrical shape, and are provided at both ends in the axial direction of the intermediate cylinder 16. Here, as shown in FIG. 7, a pair of flange portions 18 have a common center line (axis) S _2. The pair of flange portions 18 are connected by a pair of connecting plates 20 and stopper plates 21 extending in the axial direction of the flange portions 18 respectively. The pair of connecting plates 20 have a smaller radius of curvature than the flange 18 when viewed from the axial direction.
And are arranged so as to form a substantially C-shape that opens downward as shown in FIG. The stopper plate 21 connects between the upper end portions of the pair of flange portions 18 as shown in FIG. Stopper plate 21
The protrusion 21A which is bent in a U-shape so as to protrude toward the inner circumferential side relative to the flange portion 18 in the axially intermediate portion is formed, facing the axis S ₂ side of the projecting portion 21A The bottom portion is curved concentrically with the flange portion 18.

An intermediate block 14 shown in FIG. 8 is provided between the pair of flanges 18 of the intermediate cylinder 16 from below.
_{It is} inserted toward _one side. A plane portion 14A is formed on the upper surface of the intermediate block 14. The intermediate cylinder 16 forms a hollow portion on the inner peripheral side of the pair of connecting plates 20 and the stopper plate 21 so as to face the flat portion 14A of the intermediate block 14, and a vibration is formed in the hollow portion as shown in FIG. An inner cylinder fitting 22 and a reinforcing fitting 23 connected to the engine, which is a generating unit, penetrate in the axial direction. The inner cylinder fitting 22 is arranged in parallel with the outer cylinder fitting 12, and the inner cylinder fitting 22 and the outer cylinder fitting 1 are arranged in parallel.
An elastic body 24 made of rubber is stretched between the two.
When the elastic body 24 is deformed, the inner cylinder 22 can be displaced relative to the outer cylinder 12. As shown in FIG. 3, the reinforcing metal member 23 is provided with a semi-cylindrical portion 23A which is curved in a semicircular arc so as to open toward the inner cylindrical metal member 22 at both ends in the axial direction, as shown in FIG. Is provided with a connecting portion 23B connecting a pair of semi-cylindrical portions 23A at an intermediate portion in the axial direction. The deformation of the elastic body 24 in the axial direction is suppressed by the reinforcing bracket 23 and the intermediate cylinder 16.

As shown in FIG. 1, the elastic body 24 has a thin portion 24A extending from the inner peripheral side of the
Of the connecting plate 20 of FIG. On the other hand, the intermediate block 14 is formed with extending portions 14B and 14C extending along the circumferential direction at both ends in the width direction of the plane portion 14A, and covers the outer peripheral surfaces of the pair of connecting plates 20 respectively. Near the lower end of the thin portion 24A of the elastic body 24 is an extension 14B, 1
It is in close contact with the inner peripheral surface of 4C. The thin portion 24A of the elastic body 24 also covers the outer peripheral surface of the flange portion 18 as shown in FIG. 6, and the flange portion 18A as shown in FIG.
Is pressed against the inner peripheral surface of the outer cylinder fitting 12 via the thin portion 24A.

[0019] On the lower surface of the elastic body 24, a substantially V towards the axis S ₁ in the axial direction intermediate portion sandwiched between the pair of flange portions 18
1 and 4, a space between the notch portion 14E of the elastic body 24 and the flat portion 14A of the intermediate block 14 is a main liquid chamber 26. As shown in FIG.
It has been.

On the upper surface side of the elastic body 24, a diaphragm 30 is formed integrally with the elastic body 24 as a partition wall capable of elastically deforming a pair of differential sub liquid chambers 27 and 28 described later.
The diaphragm 30 includes a pair of air chamber forming portions 32 and a pair of side wall portions 34, each formed of a thin film rubber. As shown in FIG. 1, the pair of air chamber forming portions 32 has a lower end connected to the upper surface side of the elastic body 24 and an upper end connected to the inner peripheral surface of the outer cylinder fitting 12 when viewed from the axial direction. Closely adhered. Here, the pair of air chamber forming portions 32
The lower end of the inner cylindrical fitting 22 extends along the width direction of the elastic body 24.
Are respectively connected to two positions of the elastic body 24 which sandwich the
The upper end of the stopper plate 2 extends along the width direction of the elastic body 24.
1 are in close contact with the two regions of the outer tube fitting 12, respectively. As a result, the pair of air chamber forming parts 32 forms a tubular air chamber 36 that penetrates in the axial direction between the upper surface side of the elastic body 24 and the outer cylinder fitting 12. This air chamber 36
Is hollow between the pair of differential auxiliary liquid chambers 27 and 28 and above the inner cylindrical fitting 22.

The air chamber forming part 32 of the diaphragm 30
The side wall portion 34 is accommodated in the outer tube fitting 12 in a bellows-like curved state as shown in FIGS. 1 and 5. Thereby, the deformation resistance of the diaphragm 30 due to the tension when receiving the hydraulic pressure is suppressed.

On the upper surface side of the elastic body 24, a convex stopper abutting portion 38 protruding into the air chamber 36 is formed along the outer peripheral surface of the inner cylindrical fitting 22, as shown in FIGS. Have been. The protrusion 21A of the stopper plate 21 is made of rubber formed integrally with the air chamber forming portion 32, that is, integrally with the elastic body 24 via the air chamber forming portion 32, and is formed of a block-shaped elastic member. It is embedded in the support portion 39. The elastic support portion 39 is a thin film-shaped covering portion 39A on the bottom surface side of the protruding portion 21A.
A covers the entire bottom surface of the protrusion 21A. Here, the stopper plate 21 and the elastic support portion 39 are attached to the inner cylindrical fitting 2.
2 is configured as a rebound stopper 41 for limiting an upward relative displacement.

As described above, the protrusion 21A of the stopper plate 21
Is embedded in the block-shaped elastic support portion 39, whereby the stopper plate 21 is reinforced, and plastic deformation of the stopper plate 21 due to repeated stress can be suppressed. The bottom surface of the protrusion 21A covered by the elastic support portion 39 faces the top surface of the stopper contact portion 38 of the elastic body 24 at a predetermined interval. As a result, the upward displacement of the inner cylindrical member 22 and the elastic body 24 is limited, and the relative movement amount of the inner cylindrical member 22 with respect to the outer cylindrical member 12 becomes excessive even when an excessive force is input from the outside. There is no. At this time, since the bottom surface of the protruding portion 21A is covered by the covering portion 39A of the elastic support portion 39, the metal stopper plate 21 does not directly contact the stopper contact portion 38, but the stopper contact portion 38 Damage is prevented in the long run. The outer peripheral surface of the elastic support portion 39 is a convex curved surface corresponding to the inner peripheral surface of the outer cylindrical member 12, and is in close contact with the inner peripheral surface of the outer cylindrical member 12.

A pair of side wall portions 34 of the diaphragm 30
As shown in FIGS. 3 and 5, the lower end is connected to the outer portion of the air chamber 36 on the upper surface of the elastic body 24 along the width direction of the elastic body 24, respectively.
2 are closed at both axial ends. Thereby, as shown in FIG. 6, between the pair of flange portions 18 on the upper surface side of the elastic body 24, a pair of hollow portions 4 whose outer peripheral side is open and whose inner peripheral side is closed by the elastic body 24 are provided.
0,42 are formed. The pair of hollow portions 40, 42
Are arranged so as to sandwich the air chamber 36 along the width direction of the elastic body 24, and the opening on the outer peripheral side is formed in the outer cylinder fitting 1.
As a result, the first and second differential sub-liquid chambers 27 and 28 are filled with liquid as shown in FIG.

[0025] Differential auxiliary liquid chamber 27, 28 (in this embodiment the vertical direction) radially with respect to the axis S ₁ facing the main liquid chamber 26 across the axis S ₁ of the inner cylindrical member 22 along the And a diaphragm 30 which is a part of a partition wall is connected to the inner cylindrical fitting 22 via an elastic body 24, and the elastic body 24 also forms the bottom of the inner wall forming the sub liquid chambers 26 and 28. Have been.

The pair of connecting plates 20 of the intermediate cylinder 16 covered with the thin portions 24A of the elastic body 24 are provided with groove portions 44 extending along the circumferential direction between the pair of flange portions 18 as shown in FIG. , 46 are formed. The grooves 44 and 46 have their outer peripheral openings closed by the inner peripheral surface of the outer cylinder 22, and one ends of the grooves 44 and 46 are connected to the differential auxiliary liquid chambers 27 and 28, respectively.

On the other hand, as shown in FIG. 8, three grooves 48, 50, 52 are formed on the outer peripheral surface of the intermediate block 14, and these grooves 48, 50, 52 have outer cylinder fittings on the outer peripheral side. 12 is closed by the inner peripheral surface. Among these, two grooves 48 having different widths in the axial direction,
One end of each 50 is an extension 14C of the intermediate block 14.
And is connected to the groove 44 of the intermediate cylinder 16. One end of the remaining groove 52 is opened at the distal end face of the extension 14B of the intermediate block 14, and the groove 46 of the intermediate cylinder 16 is opened.
Connected to

As shown in FIG. 8, the other end of the groove 48 is connected to a through hole 54 penetrating from the flat portion 14A of the intermediate block 14 to the bottom of the outer peripheral surface of the intermediate block 14. Starting from the connection end of the extension 14B, it extends toward the extension 14B along the circumferential direction, is folded back into a U-shape before the extension 14B, and opens to the distal end surface of the extension 14C.
The groove 48 and the through hole 54 of the intermediate block 14 and the groove 44 of the intermediate cylinder 16 constitute a shake orifice 56 for absorbing shake vibration.
6, the main liquid chamber 26 and the first differential sub liquid chamber 27 are always in communication.

As shown in FIG. 1, the intermediate block 14
A circular hole 70 is formed on the side of the flat portion 14A, and a circular through hole 71 penetrating to the bottom of the outer peripheral surface of the intermediate block 14 is formed at the bottom of the circular hole 70 with a smaller diameter than the circular hole 70. It is formed coaxially with the circular hole 70. A circular concave counterbore 72 is formed coaxially with the circular through hole 71 on the outer peripheral surface of the intermediate block 14, and an annular groove 74 is provided outside the counterbore 72. This groove 7
An O-ring 76 for sealing is fitted in 4.
A circular opening 12 </ b> A having the same inner diameter as the counterbore 72 is formed coaxially in the outer tube fitting 12.

A rotary valve 78 is rotatably inserted into the circular hole 70 and the circular through hole 71 of the intermediate block 14. A large-diameter cylindrical portion 80 having an open upper surface is provided above the rotary valve 78, and a small-diameter shaft portion 82 is provided coaxially with the cylindrical portion 80 on the opposite side to the cylindrical portion 80. As shown in FIG. 8, the middle block 14 is formed with a fitting portion 83 having a recessed middle portion in the width direction on the upper surface, and the fitting portion 83 has a lid bent in a substantially U-shape. The plate 84 is inserted. This cover plate 84 has a circular hole 70.
A circular opening 84A having a diameter smaller than that of the circular hole 70 is formed, and the cover plate 84 allows the inside of the cylindrical portion 80 of the rotary valve 78 to communicate with the main liquid chamber 27 through the circular opening 84A. From the circular hole 70 is prevented. A pair of annular grooves are formed on the outer peripheral surface of the shaft portion 82 of the rotary valve 78, and a pair of O-rings 86 are fitted into the pair of annular grooves, respectively. The O-ring 86 prevents liquid leakage from the circular through hole 71.

As shown in FIG. 1, a pair of passages 88 and 90 are formed inside the intermediate block 14 so as to extend in the radial direction from the inner peripheral surface of the circular hole 70 in the radial direction. I have. One of the passages 88 extends from the inner peripheral surface of the circular hole 70 toward the extending portion 14 </ b> C of the intermediate block 132 and is connected to the groove 50 formed on the outer peripheral surface of the intermediate block 14. Therefore, the passage 88 is provided in the intermediate block 1.
4 and the first differential sub-liquid chamber 27 through the groove portion 44 of the intermediate cylinder 16 and the passage 88 and the groove portions 44 and 5.
Reference numeral 0 denotes an idle orifice 58 which is a restriction passage for absorbing idle vibration.

The other passage 90 extends from the inner peripheral surface of the circular hole 70 toward the extending portion 14B, and
Is connected to a groove 52 provided on the outer peripheral surface of the. Therefore, the passage 90 communicates with the second differential sub-liquid chamber 28 via the groove 52 of the intermediate block 14 and the groove 46 of the intermediate cylinder 16, and the passage 90 and the grooves 46 and 52 are restricted for absorbing the booming sound. An orifice 60 for a muffler, which is a passage, is formed. The main liquid chamber 26 and the pair of differential sub liquid chambers 27 and 2
Each of the liquids 8 is filled with a liquid such as ethylene glycol.

The cylindrical portion 80 of the rotary valve 78 has a through hole 106 formed on the outer peripheral surface thereof. The through hole 106 connects the inside and the outside of the cylindrical portion 80. Thus, as shown in FIG. 1, when the rotary valve 78 rotates to a position where the through hole 106 faces the passage 88, the idle orifice 78 establishes a gap between the main liquid chamber 26 and the first differential sub liquid chamber 27. When the rotary valve 78 is rotated to the position where the through hole 106 is opposed to the passage 90 as shown in FIG. 2, the orifice 60 is closed between the main liquid chamber 26 and the second differential sub liquid chamber. To communicate with each other.

On the other hand, a motor unit 108 having a motor for operating the rotary valve 78, a torque transmission mechanism, and the like is mounted on the outer peripheral surface of the outer tube fitting 12, as shown in FIG. The motor unit 108 includes a casing 110 that forms an outer shell. On the upper portion of the casing 110, a mounting flange 112 that is curved in an arc shape along the outer peripheral surface of the outer cylinder fitting 12 is disposed. A valve differential shaft 114 projects from the center of the upper surface of 112. A connecting portion 114 formed in a plate shape along the axial direction is provided at a distal end portion of the valve differential shaft 114.
A is formed. The motor unit 108 is fixed to the outer cylinder fitting 12 by screwing a screw (not shown) inserted through the mounting flange 112 into a female screw hole (not shown) formed in the outer cylinder fitting 12. At this time, the valve differential shaft 114 is inserted into the intermediate block 12 through the circular opening 12A of the outer cylinder fitting 12 and the counterbore portion 72, and the coupling portion 114A extends along the radial direction formed on the lower surface of the shaft portion 82. It is inserted into the groove. As a result, the valve differential shaft 114 is connected to the rotary valve 78.

A motor switch (not shown) for detecting the position (phase) of the rotary valve 78 in the rotation direction and stopping the rotation of the motor is disposed inside the motor unit 108. Motor unit 108
After the start of rotation, the rotary valve 78 is synchronized with the detection operation by the motor switch so that the main liquid chamber 2 shown in FIG.
6 and a position where the first differential sub liquid chamber 27 communicates with each other through an idle orifice 58 (hereinafter referred to as a first position).
The rotation of the main liquid chamber 26 and the second differential sub liquid chamber 28 shown in FIG. 2 is stopped at any one of positions (hereinafter, referred to as a second position) in which the orifices 60 for converging communicate with each other.

The motor unit 108 is connected to the controller 120 as shown in FIG.
Starts rotating in one direction. The controller 120 receives the detection signals from at least the vehicle speed sensor 122 and the engine speed detection sensor 124, detects the vehicle speed and the engine speed, respectively, and changes the current vehicle vibration state in a certain cycle to the idle vibration state where the ratio of the idle vibration increases. Judgment is made between the vibration state and the shake vibration state in which the ratio of the shake vibration increases, and when the vibration state of the vehicle changes from the idle vibration to the shake vibration state, or when the vehicle changes from the shake vibration state to the idle vibration state, the switching signal is output. Motor unit 108
Output to

Next, the operation of the vibration isolator 10 according to this embodiment will be described.

In the vibration isolator 10 of the present embodiment, when the engine (not shown) is mounted, the elastic body 24 which receives a load from the engine via the inner cylinder 22 is deformed, and the inner cylinder 22 is deformed. It becomes coaxial with the outer tube fitting 12. When the engine connected to the inner cylinder 22 operates, vibration from the engine is transmitted to the elastic body 24 via the inner cylinder 22. At this time, the elastic body 24 acts as a vibration absorber,
Vibration energy is absorbed by the internal friction of the elastic body 24.

Further, the vibration isolator 10 of the present embodiment is provided with a rotary valve 78 for selectively opening only one of the idle orifice 58 and the squeezing orifice 60, and a pair of differential valves opened and closed by the rotary valve 78. The moving auxiliary liquid chambers 27 and 28 are respectively provided with the axis S
The main liquid chamber 26 across the axis S ₁ along the radial direction with respect to ₁
The diaphragm 30 which is arranged so as to be opposed to and which is a part of the partition wall of the first differential sub liquid chamber 27 is connected to the inner cylinder fitting 22 via the elastic body 24, and the differential Since the bottom portions of the inner walls of the liquid chambers 27 and 28 are formed, the following operation is achieved.

For example, when the vehicle accelerates from an idling state and runs at a high speed of 70 to 80 km / h or more, a shake vibration state occurs. At this time, the controller 110 includes a vehicle speed sensor 122 and an engine speed detection sensor 124.
When it is determined from the signal from that that the vibration state of the vehicle has changed to the shake vibration state, the rotary valve 78 is rotated by the motor unit 108 from the first position shown in FIG. 1 to the second position shown in FIG. . As a result, the idle orifice 58 is closed, and the orifice 60 is opened. Accordingly, the main liquid chamber 26 is communicated with the first differential auxiliary liquid chamber 27 by the shake orifice 56 which is always open, and the differential auxiliary liquid chamber 28 is opened by the retentive orifice 60 opened by the rotary valve 78.
Is communicated with. Then, the controller 110 determines the vibration state of the vehicle at regular intervals, and stops the rotary valve 78 at the second position if the shake vibration state continues.

As a result, when the inner cylinder 22 is relatively moved with respect to the outer cylinder 12 due to vibration from the engine, the elastic body 24 is elastically deformed to expand or contract the inner volume of the main liquid chamber 26. Due to the displacement of the diaphragm 30 connected to the inner cylinder fitting 22 and the deformation of the elastic body 24 forming a part of the inner wall of the first differential sub-liquid chamber 27, the internal volume of the first differential sub-liquid chamber 27 becomes the main liquid. It changes in the opposite direction to the chamber 26. As described above, by changing the internal volume of the first differential sub liquid chamber 27 in conjunction with the movement of the inner cylinder 22, the internal pressure (hydraulic pressure) between the main liquid chamber 26 and the first differential sub liquid chamber 27 is changed. Therefore, a large liquid column resonance can be generated between the main liquid chamber 26 and the first differential sub liquid chamber 27 through the shake orifice 56. Accordingly, the vibration energy of the shake vibration is changed by the viscous resistance and the pressure change of the liquid in the shake orifice 56,
In particular, since the vibration can be effectively absorbed, the vibration damping effect against shake vibration can be improved.

Further, a low-speed muffled sound (8) which is a high-frequency and small-amplitude vibration that may be generated simultaneously with the shake vibration.
(About 0 Hz), the inner volume of the second differential sub liquid chamber 28 changes in the opposite direction to the main liquid chamber 26, similarly to the first differential sub liquid chamber 27, and the main liquid chamber 26 and the second Since the difference between the internal pressure (hydraulic pressure) and the differential auxiliary liquid chamber 28 can be increased, the orifice 60
, A large liquid column resonance can be generated between the main liquid chamber 26 and the second differential sub liquid chamber 28. Therefore, the vibration energy of the muffled sound can be particularly effectively absorbed by viscous resistance and pressure change of the liquid in the muffled orifice 60.
The vibration-proof (sound-proof) effect against the muffled sound vibration can be improved.

For example, when a vehicle traveling at a high speed of 70 to 80 km / h or more decelerates and travels at a low speed of 5 km / h or less, or stops and enters an idling state, the vibration state of the vehicle is changed to shake vibration. The state changes from the state to the idle vibration state. When the controller 110 determines that the vibration state of the vehicle has changed from the shake vibration state to the idle vibration state based on signals from the vehicle speed sensor 122 and the engine speed detection sensor 124, the rotary valve 78 is shown by the motor unit 108 in FIG. Rotate from the second position to the first position shown in FIG. Thereby, the orifice 60 is closed and the idle orifice 58 is opened. Therefore, the main liquid chamber 26 is communicated with the first differential sub liquid chamber 27 by the shake orifice 56 which is always open and the idle orifice 58 which is opened by the rotary valve 78. And the controller 110
Determines the vibration state of the vehicle at regular intervals, and turns on the rotary valve 78 when the idle vibration state continues.
Stop at the position.

As a result, when the inner cylinder 22 is relatively moved with respect to the outer cylinder 12 by vibration from the engine, the elastic body 24 is elastically deformed, and the inner volume of the main liquid chamber 26 is expanded or contracted. Due to the displacement of the diaphragm 30 connected to the inner cylinder fitting 22 and the deformation of the elastic body 24 forming a part of the inner wall of the first differential sub-liquid chamber 27, the internal volume of the first differential sub-liquid chamber 27 becomes the main liquid. It changes in the opposite direction to the chamber 26. As described above, by changing the internal volume of the first differential sub liquid chamber 27 in conjunction with the displacement of the inner cylinder 22, the internal pressure (hydraulic pressure) between the main liquid chamber 26 and the first differential sub liquid chamber 27 is changed. Can be increased, a large liquid column resonance can be generated by passing the shake orifice 56 and the idle orifice 58 between the main liquid chamber 26 and the first differential sub liquid chamber 27, respectively. Thereby, the vibration energy of the shake vibration and the idle vibration can be particularly effectively absorbed by the viscous resistance and the pressure change of the liquid in the shake orifice 56 and the idle orifice 58, so that the vibration damping effect against the shake vibration and the idle vibration can be improved.

As described above, according to the anti-vibration device 10 of the present embodiment, it is possible to prevent typical vibrations (noise) such as shake vibration, idle vibration and muffled noise in a vehicle without increasing the size of the device. The vibration effect can be improved.

According to the vibration isolator 10 of the present embodiment,
A pair of differential sub-liquid chambers 27 and 28 are arranged inside the outer cylinder fitting 12 so as to face each other along the circumferential direction of the inner cylinder, and an inner cylinder is provided between the pair of differential sub-liquid chambers 27 and 28. By providing a rebound stopper 41 that opposes the outer peripheral surface of the metal fitting 22 and restricts the relative movement of the inner cylindrical metal fitting 22 to the outer cylindrical metal fitting 12, the main liquid chamber 26 is interposed between the elastic body 24 along the vertical direction. The differential auxiliary liquid chambers 27 and 28 which are opposed to each other and the lower end of the diaphragm 30 is connected to the inner cylinder can be arranged in a space in the outer cylinder fitting which cannot be effectively used in the conventional vibration isolator. The pair of differential auxiliary liquid chambers 27 and 28 can be arranged by efficiently using the space in the cylindrical fitting 22. When molding the elastic body 24, a core set in a portion corresponding to a space between the pair of differential auxiliary liquid chambers 27 and 28 in a mold (not shown) can be removed along the axial direction after completion of molding. Therefore, the rebound stopper 41 can be formed integrally with the elastic body 24 and the intermediate cylinder 16 as a reinforcing member.

In the vibration isolator 10 of the present embodiment, the rebound stopper 41 is constituted by the stopper plate 21 of the intermediate cylinder 16 and the elastic supporting portion 39 for reinforcing the stopper plate 21. However, the rebound stopper 41 has sufficient strength to resist external force. If possible, the rebound stopper may be constituted by only one of the stopper plate 21 and the elastic support portion 39.

Further, in the vibration isolator 10 of the present embodiment, the differential sub-liquid chamber 27 is used as a sub-liquid chamber for absorbing shake vibration and idle vibration, and the differential sub-liquid chamber 28 is used as a sub-liquid chamber for absorbing muffled sound. A differential sub-liquid chamber or a normal sub-liquid chamber connected to the main liquid chamber 26 by an orifice is additionally provided in the outer cylinder 12, and any of shake vibration, idle vibration and muffled sound is provided by the added sub-liquid chamber. And the three sub liquid chambers may absorb different types of vibration.

[0049]

As described above, according to the vibration damping device of the present invention, a pair of differential auxiliary liquid chambers can be easily provided in the outer cylinder, and the relative movement of the inner cylinder is restricted. The stopper member to be formed can be formed integrally with the elastic body or the elastic reinforcing member.

[Brief description of the drawings]

FIG. 1 is an axial sectional view showing a state in which an idle orifice of a vibration isolator according to an embodiment of the present invention is opened.

FIG. 2 is an axial cross-sectional view showing a state in which an orifice for a built-in damper of the vibration isolator according to the embodiment of the present invention is opened.

FIG. 3 is a front view of the vibration isolator according to the embodiment of the present invention as viewed from an axial direction.

4 is a cross-sectional view of the vibration isolator according to the embodiment of the present invention, taken along line IV-IV shown in FIG.

FIG. 5 is a sectional view of the vibration isolator according to the embodiment of the present invention, taken along line VV shown in FIG. 3;

FIG. 6 is an exploded perspective view showing a vibration isolator (excluding an intermediate block) according to the embodiment of the present invention.

FIG. 7 is a perspective view showing an intermediate cylinder of the vibration isolator according to the embodiment of the present invention.

FIG. 8 is a perspective view showing an intermediate block of the vibration isolator according to the embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 outer cylinder fitting (outer cylinder) 22 inner cylinder fitting (inner cylinder) 24 elastic body 27 first differential sub liquid chamber 26 main liquid chamber 28 second differential sub liquid chamber 30 diaphragm (partition wall) 41 rebound stopper (stopper member) ) 56 Shake orifice (liquid passage) 58 Idle orifice (liquid passage) 60 Orifice (liquid passage)

Claims (2)

[Claims] An outer cylinder connected to one of the vibration generating section and the vibration receiving section; and an inner cylinder connected to the other of the vibration generating section and the vibration receiving section and arranged on an inner peripheral side of the outer cylinder. An elastic body disposed between the outer cylinder and the inner cylinder and connected to the outer cylinder and the inner cylinder; and a main liquid chamber in which at least a part of an inner wall is formed by the elastic body and a liquid is sealed. At least a part of the partition wall facing the main liquid chamber and forming the sub liquid chamber with the elastic body interposed therebetween is connected to the inner cylinder, and the contents are linked to relative displacement of the inner cylinder with respect to the outer cylinder. A vibration isolator having a differential sub liquid chamber whose product is expanded and contracted, and a liquid passage connecting the differential sub liquid chamber to the main liquid chamber, wherein a pair of the differentials is provided in the outer cylinder. Sub liquid chambers are arranged so as to face each other along the circumferential direction of the inner cylinder, and between the pair of differential sub liquid chambers, The stopper member to restrict relative movement relative to the outer cylinder of the inner cylinder opposite the outer circumferential surface of the inner cylinder is provided vibration damping device according to claim. 2. A reinforcing member comprising a pair of flange portions to which both ends in the axial direction of the elastic body are fixed, and a connecting portion connecting the pair of flange portions and forming at least a part of the stopper member. The anti-vibration device according to claim 1, wherein the anti-vibration device has: