JP2002327788A - Vibrationproof device sealed with fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To depress an action force onto a fixing port for a vibration member or a support member of a first and a second fitting members to improve the strength and durability of the fixing port when applying the vibrationproof device to an engine mount for automobiles, for instance, in the vibration proof device sealed with fluid in which a support shaft formed in a first fitting member is inserted from one axial opening at a cylindrical part formed in a second fitting member to arrange it and the cylindrical part and the support shaft part are connected elastically by an elastic rubber body. SOLUTION: A pair of action liquid chamber 98, 98 oppositely positioning in the axial direction inside of the rubber elastic body and set to communicate with each other through an orifice passage 108 are formed, and the spring constant in the direction orthogonal to the axis in the axis in the elastic wall of the axial inward of these liquid chambers 98, 98 is made larger than the spring constant in the direction orthogonal to the axis in the elastic wall of the axial outward of respective action liquid chambers to divert the elastic center in the elastic rubber body 16 to the extremity side of the support shaft 20 in the first fitting member 12 and set it there.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid-filled type vibration damping device which obtains a vibration damping effect based on a flow action of an incompressible fluid sealed therein, and more particularly to a fluid-filled vibration damping device in a central axis direction and a direction perpendicular to the axis. The present invention relates to a fluid-filled type vibration damping device that exhibits an effective vibration damping effect based on the flow action of an incompressible fluid with respect to input vibration in any direction, and can be suitably used for, for example, an engine mount for an automobile. .

[0002]

2. Description of the Related Art Conventionally, as one type of a vibration isolating device as a vibration isolating connection member or a vibration isolating support member interposed between members constituting a vibration transmission system, resonance of an incompressible fluid enclosed therein has been performed. 2. Description of the Related Art A fluid-filled type vibration damping device that obtains a vibration damping effect based on a flow action such as an action is known.
No. 533 and Japanese Patent Application Laid-Open No. Sho 61-262244 disclose a vibration damping effect based on the flow action of an incompressible fluid with respect to both input vibrations in the central axis direction and the direction perpendicular to the axis. A fluid-filled anti-vibration device is disclosed.

In such a fluid-filled type vibration damping device, the first mounting member is spaced apart from one of the cylindrical portions formed on the second mounting member in the axial direction, and the first mounting member is separated from the first mounting member. The support shaft part formed in the second mounting member is disposed so as to extend into the cylindrical part of the second mounting member so as to extend in the axial direction, and the support shaft part and the cylindrical part are elastically connected by a rubber elastic body. The one opening in the axial direction of the cylindrical portion is closed in a fluid-tight manner with the main rubber elastic body to form a main liquid chamber in the cylindrical portion, and the space between the first mounting member and the second mounting member is formed. While forming a sub liquid chamber in which a relative pressure fluctuation is generated with respect to the main liquid chamber at the time of axial vibration input, the main liquid chamber and the sub liquid chamber communicate with each other through a first orifice passage, A pair of working fluid chambers located on both sides of the main rubber elastic body with the support shaft portion sandwiched in the direction perpendicular to the axis. In addition, the pair of working fluid chambers are connected to each other by a second orifice passage, and when the axial vibration is input between the first mounting member and the second mounting member, An anti-vibration effect is provided based on the resonance action of the fluid caused to flow through the first orifice passage between the liquid chamber and the sub-liquid chamber, and an axis perpendicular to the axis between the first mounting member and the second mounting member. At the time of inputting directional vibration, a vibration damping effect can be exerted on the basis of the resonance action of the fluid flowing through the second orifice passage between the pair of working liquid chambers.

[0004] Such a fluid-filled type vibration damping device is employed, for example, in an engine mount for a horizontal engine in an FF (Front Engine / Front Drive) type vehicle to fix a first mounting member to a power unit,
By fixing the second mounting member to the body and supporting the power unit against vibration with respect to the body, the vibration damping effect based on the resonance action of the fluid against the vertical vibration and the longitudinal vibration of the vehicle can be achieved. You can get it.

In order to realize an effective and effective anti-vibration support effect in a power unit anti-vibration support system in a laterally mounted engine FF type vehicle, the left and right sides of the power unit are respectively mounted on the main axis of inertia of the power unit. Let the body support anti-vibration through the mount,
It is desirable to have an uncoupled anti-vibration support structure.

However, in recent automobiles, the space for disposing the engine mount is limited due to the reduction in the volume of the engine room accompanying the securing of the cabin volume and the increase in various auxiliary devices provided in the engine room. In an FF type vehicle with a horizontal engine, the engine mount is often arranged on the tire housing due to the engine layout, and the first mounting member of the engine mount is attached to the power unit. When the fixed point is set at a higher position of the power unit, the vibration-proof support position of the power unit by the engine mount tends to be shifted vertically above the main axis of inertia of the power unit.

[0007] Therefore, there is a problem that it is difficult for the engine unit to sufficiently exhibit the anti-vibration performance of the power unit, and it is difficult to obtain an effective anti-vibration effect.

When mounting the engine mount on the tire housing, generally, the first and second mounting members are arranged so that their central axes extend substantially vertically.
The first mounting member is arranged on the opening side above the second mounting member in the axial direction, and the axial lower end of the second mounting member is connected and fixed to the body. The input position of the vibration load from the first mounting member fixed to the power unit tends to be greatly separated vertically upward with respect to the fixing portion of the second mounting member to the body. The moment force applied to the portion of the second attachment member fixed to the body due to the input load from the attachment member increases, and there is a possibility that the strength of the member, the attachment strength, the durability, and the like at the attachment portion may become a problem.

[0009]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a vibration isolating support position of a power unit when applied to, for example, an engine mount for an automobile. A fluid-filled type prevention device with a novel structure that can be set at a lower position in the axial direction and that can reduce the acting force of the first and second mounting members to the fixed portions to the vibration member and the support member. A vibration device is provided.

[0010]

An embodiment of the present invention which has been made to solve such a problem will be described below. The components employed in each of the embodiments described below can be employed in any combination as possible. In addition, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or based on the invention ideas that can be understood by those skilled in the art from the descriptions. It should be understood that it is recognized on the basis of.

That is, the features of the present invention are as follows:
The first mounting member is separated from the cylindrical portion formed on the second mounting member at one opening side in the axial direction, and is inserted into the cylindrical portion of the second mounting member to form the cylindrical portion. The first mounting member is provided with a supporting shaft portion extending in the axial direction, and the supporting shaft portion of the mounting member and the cylindrical portion of the second mounting member are elastically connected by a main rubber elastic body. By closing one opening in the axial direction of the cylindrical portion with a rubber elastic body in a fluid-tight manner, the rubber elastic body is positioned axially inward of the first mounting member within the cylindrical portion, and A main liquid chamber in which a part of the wall is formed is formed, and the main liquid chamber is formed relative to the main liquid chamber when an axial vibration is input between the first mounting member and the second mounting member. Forming a sub-liquid chamber where pressure fluctuations are generated, and further enclosing an incompressible fluid in the main liquid chamber and the sub-liquid chamber,
In the fluid filled type vibration damping device having a first orifice passage communicating the main liquid chamber and the sub liquid chamber with each other, the support shaft portion of the first mounting member is pivoted inside the main rubber elastic body. A pair of working fluid chambers are provided on both sides sandwiched in the right angle direction and extend in the circumferential direction with a length of not more than half a circumference, and the incompressible fluid is sealed in the pair of working fluid chambers, and the pair of working fluid chambers are sealed. While forming a second orifice passage that communicates the liquid chambers with each other, the spring constant in the axial perpendicular direction of the axially inner elastic wall portion of each working liquid chamber formed by the main rubber elastic body is defined as: The spring constant of the elastic wall portion in the axially outward direction of the working liquid chamber is larger than the spring constant in the direction perpendicular to the axis.

In the fluid filled type vibration damping device having such a structure according to the present invention, the working liquid chamber is formed so that the main body is substantially divided on both sides sandwiching the working liquid chamber in the axial direction. By setting the spring constant in the direction perpendicular to the axis of the rubber elastic body so that the elastic wall portion in the axially inner direction is larger than the elastic wall portion in the axially outward direction, the shaft on which the working liquid chamber is opposed to the axial direction. The elastic support center for the input load in the perpendicular direction can be set on the projecting tip side of the support shaft in the axial direction of the first and second mounting members.

[0013] Therefore, the first mounting member of the main rubber elastic body is located higher than the fixing point of the power unit or the like with respect to the first mounting member projected axially outward from the cylindrical portion of the first mounting member. The elastic support center point can be set axially inward of the second mounting member, thereby applying the present invention to, for example, an FF type vehicle engine mount, thereby achieving the second mounting member as described above. The elastic support position of the power unit can be set sufficiently vertically below the fixed position of the power unit with respect to the fixed position of the power unit with respect to the first mounting member protruded vertically upward from the cylindrical portion of the member. And the moment acting on the fixed point of the first and second mounting members with respect to the power unit and the body is reduced, These improved fixedly member strength and durability is of also be achieved.

In the fluid filled type vibration damping device according to the present invention, the fixing structure and the fixing position of the first and second mounting members to the vibrating member and the supporting member are not limited at all. For example, the first mounting member, at the tip portion protruding axially outward from the cylindrical portion of the second mounting member,
On the other hand, the second mounting member is attached to one of the members that are connected to the vibration-proof connection, and the second mounting member is connected to the vibration-proof connection at the axial end side of the cylindrical portion opposite to the side where the first mounting member is provided. A configuration that can be attached to the other member directly or via a bracket or the like can be advantageously employed. By adopting such a configuration, the first and second attachment members can be easily attached to the respective members that are connected by vibration isolation.

Further, in the fluid filled type vibration damping device according to the present invention, the spring constant in the direction perpendicular to the axis in the axially inner elastic wall of each working liquid chamber formed by the main rubber elastic body is determined by The specific structure for setting the spring constant in the direction perpendicular to the axis in the elastic wall portion outward in the axial direction of the liquid chamber is not particularly limited, for example,
(A) A structure in which the axial thickness of the elastic wall portion inside the working liquid chamber in the axial direction is set larger than the axial thickness of the elastic wall portion outside the working liquid chamber in the axial direction. (B) In the main rubber elastic body, each working liquid is larger than the free length between the first mounting member and the second mounting member of the portion forming the elastic wall portion on the outside in the axial direction of each working liquid chamber. A structure in which the free length between the first mounting member and the second mounting member of the portion forming the elastic wall portion inside the chamber in the axial direction is set to be small; Structures in which the inclination angle of the elastic wall portion in the axial direction is set to be larger than the inclination angle of the elastic wall portion in the axial direction of each working liquid chamber in the axial direction, or (a) to (c).
A structure obtained by appropriately combining (c) and the like can be suitably adopted.

Further, in the fluid filled type vibration damping device according to the present invention, the first mounting member is vulcanized and adhered to the main rubber elastic body, and the support shaft of the first mounting member in the main rubber elastic body. A pair of pockets are formed on the outer peripheral surface on both sides sandwiching the portion in the direction perpendicular to the axis, and a metal sleeve is vulcanized and bonded to the outer peripheral surface of the rubber elastic body. A pair of pockets is formed by forming a pair of windows facing each other and opening a pair of pockets through the windows, and a cylindrical portion of the second mounting member is externally fitted and fixed to the metal sleeve. A configuration in which a pair of working liquid chambers are formed by covering the liquid in a fluid-tight manner can be suitably adopted. By adopting such a configuration using a metal sleeve, the main liquid chamber and the pair of fluid chambers are independent from each other by securing fluid tightness at the fitting portion of the metal sleeve to the cylindrical portion of the mounting member. It can be easily formed with a high degree of fluid tightness, and also prevents deformation of the elastic walls on both sides in the axial direction of the pocket during assembly and manufacture. It becomes.

When the metal sleeve as described above is employed, a step is provided at an intermediate portion in the axial direction of the metal sleeve, and a step is provided on the outer peripheral surface of the elastic wall portion outwardly in the axial direction of the pair of working liquid chambers. The inner annular portion which is vulcanized and bonded to the outer peripheral surface of the elastic wall portion in the axial direction of the pair of working liquid chambers has a smaller diameter than the outer annular portion which is sulfur bonded, and the inner annular portion of the metal sleeve is cylindrical. The orifice member is extrapolated and arranged, and the orifice member is sandwiched between the inner annular portion and the cylindrical portion of the second mounting member, and the orifice member is paired along the inner peripheral surface of the cylindrical portion. It is preferable to employ a configuration in which the orifice member extends and is disposed in the working liquid chamber, and the orifice member forms a second orifice passage that connects the pair of working liquid chambers to each other. By adopting the configuration using such an orifice member, the degree of freedom in design such as the passage length and the cross-sectional area of the second orifice passage that connects the pair of working liquid chambers to each other can be improved. By the thickness of the orifice member disposed on the outer peripheral surface of the elastic wall portion inside the liquid chamber in the axial direction, the free length of the elastic wall portion inside the working liquid chamber in the axial direction is The elastic wall portion is smaller than the free length of the elastic wall portion, so that the elastic wall on the inner side in the axial direction of the working liquid chamber does not adversely affect the fluid tightness of the working liquid chamber and does not require special members or processing. The spring constant in the direction perpendicular to the axis of the portion can be set to be larger than the spring constant in the direction perpendicular to the axis of the elastic wall portion outward in the axial direction.

On the other hand, in the fluid filled type vibration damping device according to the present invention, the sub-liquid chamber communicated with the main liquid chamber through the first orifice passage is, for example, (d) a cylinder in the second mounting member. An intermediate portion in the axial direction of the shape is partitioned by a partition member, and a main liquid chamber is formed on one side in the axial direction with the partition member interposed therebetween, and a sub liquid chamber is formed on the other axial side with the partition member interposed therebetween. It can be formed advantageously by forming a part of the wall portion of the sub liquid chamber with a flexible film, or (e) in the pair of working liquid chambers, the elastic wall outward in the axial direction. The expansion spring constant of the portion is smaller than the expansion spring constant of the elastic wall portion inward in the axial direction, and the main fluid chamber is communicated with the pair of working fluid chambers by the first orifice passage. To configure the sub liquid chamber by the working liquid chamber So that the it may be advantageously formed.

According to the configuration (d), the sub-liquid chamber is formed independently of the main liquid chamber and the working liquid chamber. Therefore, it is possible to set a sufficiently small wall spring characteristic and a large volume variable amount with respect to the vibration, thereby preventing vibration in a low frequency range particularly based on the resonance action of the fluid that is caused to flow through the first orifice passage. The vibration effect can be obtained more advantageously. In addition, according to the above configuration (e), there is no need to provide an independent auxiliary liquid chamber, the height of the vibration isolator in the axial direction can be designed to be more compact, and the second mounting member can be formed as the first mounting member. Even when the fixing member is fixed to the anti-vibration connector or the anti-vibration support at the axial end side opposite to the side where the mounting member is disposed, the moment force acting on the fixing portion is more advantageously reduced, and the member at the fixing portion is reduced. Further improvement in strength and durability can be achieved. Furthermore, according to the configuration (e), the expansion spring constant of the elastic wall portion on the axially outer side in the working liquid chamber is set smaller than the expansion spring constant of the elastic wall portion on the axially inner side. At the time of axial vibration input, pressure absorption of the main liquid chamber due to deformation of the elastic wall portion inward in the axial direction of the working liquid chamber is suppressed, and the fluid flow amount through the first orifice passage is advantageously secured. Therefore, the vibration damping effect based on the flow action of the fluid that is caused to flow through the first orifice passage can be effectively exerted. The expansion spring constant of the elastic wall of the working liquid chamber corresponds to the pressure change amount of the working liquid chamber required to change the volume of the working liquid chamber by a unit amount.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show an automobile engine mount 10 according to a first embodiment of the present invention. In this engine mount 10, a first mounting member 12 as a first mounting member and a second mounting member 14 as a second mounting member are spaced apart from each other. The second mounting member 14 has a structure in which the first mounting member 12 is attached to the power unit of the vehicle, while the second mounting member 14 is attached to the body of the vehicle. As a result, the power unit is supported on the body with vibration isolation. The engine mount 10 of the present embodiment is mounted in a state where the vertical direction in FIG. 1 is substantially vertical and the vertical direction. In the following description, the vertical direction is basically the vertical direction in FIG. Shall be referred to.

More specifically, the first mounting member 12 has a support shaft portion 20 having a solid small diameter circular rod shape, and is provided at the upper end in the axial direction of the support shaft portion extending straight in the vertical direction. On the other hand, a mounting fixing portion 22 that extends in a thick flat shape on the central axis is integrally formed. Note that a tapered portion 24 is provided at an intermediate portion in the axial direction of the support shaft portion 20.
With the tapered portion 24 interposed therebetween, a lower portion in the axial direction of the support shaft portion 20 is a small-diameter portion 26, and an upper portion in the axial direction of the support shaft portion 20 is a large-diameter portion 28.

On the outer peripheral side of the first mounting bracket 12,
A metal sleeve 30 having a thin, large-diameter cylindrical shape is disposed on the same central axis at a predetermined distance in the radial direction. The metal sleeve 30 has a stepped cylindrical shape in which an axial middle portion is smaller in diameter than both axial end portions, and a circumferential groove 32 extending in the circumferential direction with the axial middle portion opened to the outer peripheral surface. Is formed. Also, the metal sleeve 30
A pair of windows 34, 34 are formed in the axially intermediate portion at portions opposed to each other in one radial direction.
4 have an axial width slightly larger than the circumferential groove 32 and are opened in the circumferential direction with a length of less than half a circumference. In addition, the circumferential groove 3 is formed by the pair of windows 34, 34.
2 are divided in the circumferential direction, and the adjacent window portions 34, 34
The circumferential groove 32 is formed so as to extend in the circumferential direction so as to straddle between circumferential end portions of the circumferential direction.

The first mounting member 12 is provided so as to be inserted from the axially upper opening of the metal sleeve 30, and the small-diameter portion 26 of the supporting shaft portion 20 of the first mounting member 12 is formed. In a state where the whole is separated and radially surrounded,
A metal sleeve 30 is located. Note that the mounting fixing portion 22 of the first mounting bracket 12 is
While projecting axially upward from
The lower end in the axial direction of the support shaft portion 20 is located at an intermediate portion in the axial direction that does not reach the lower end in the axial direction of the metal sleeve 30.

Further, a main rubber elastic body 16 is disposed between the support shaft portion 20 of the first mounting member 12 and the radially opposed surfaces of the metal sleeve 30.
2 and the metal sleeve 30 are elastically connected. The main rubber elastic body 30 has a thick cylindrical shape as a whole, and its inner peripheral surface is vulcanized and adhered to the outer peripheral surface of the support shaft portion 20 of the first mounting bracket 12. The outer peripheral surface is vulcanized and bonded to the inner peripheral surface of the metal sleeve 30. In short, the main rubber elastic body 16 is formed as an integrally vulcanized molded product including the first mounting member 12 and the metal sleeve 30. The rubber elastic body 16 is connected to the metal sleeve 3 through the windows 34 and 34 of the metal sleeve 30.
Filling rubbers 36, 36 are formed in the peripheral groove 32 which is extended to the outer peripheral surface of the cylinder 0 and divided by the windows 34, 34, respectively.

The main rubber elastic body 16 has a large-diameter circular recess 40 which opens downward at the lower end surface in the axial direction.
Are formed, and a pair of pockets 42, 42 opening to the outer peripheral surface are formed on both sides of the first mounting bracket 12 in one radial direction. Each of the pair of pockets 42 has an expanded shape in which the axial opening width gradually increases as approaching the opening (see FIG. 1).
And a pair of windows 3 formed in the metal sleeve 30 and having a length of less than half a circumference in the circumferential direction (see FIG. 2).
4, 34, it is opened to the outer peripheral surface.

Here, the pair of pocket portions 42, 4
Each of the pockets 42 is formed so as to be deviated by a predetermined amount from the axial center of the main rubber elastic body 16 in the axial direction upward, and thereby each pocket portion 42 formed by the main rubber elastic body 16 is formed. The axial upper wall portion 44 and the axial lower wall portion 46 have different thicknesses, and the axial lower wall portion 46 is made thicker overall than the axial upper wall portion 44. I have. As a result, the axial lower wall portion has a larger axial and radial spring constant than the axial upper wall portion 44, and the spring constant in the bulging direction as the expanded spring constant is smaller. The axial upper wall is smaller than the lower axial wall. In addition, each of these pocket portions 42
In each of the upper and lower walls in the axial direction, the elastic center line extending in the radial direction is inclined so as to expand outward in the axial direction.

On the other hand, the second mounting member 14 has a cylindrical shape having a diameter larger than that of the metal sleeve 30, and a step portion 50 which expands in the radial direction is formed at an intermediate portion in the axial direction.
A large-diameter cylindrical portion 52 is formed on the upper side in the axial direction with the step portion 50 interposed therebetween, and a small-diameter cylindrical portion 54 is formed on the lower side in the axial direction. The large-diameter tubular portion 52 has substantially the same axial length as the metal sleeve 30, while the open end of the small-diameter tubular portion 54 has a slightly smaller diameter than the small-diameter tubular portion 54 and has an annular fixing portion. The outer peripheral edge of a diaphragm 58 as a flexible film is vulcanized and bonded to the annular fixing portion 56. The diaphragm 58 is
The diaphragm 58 is formed of a thin rubber elastic film and has a disk shape with a slack central portion so that deformation can be easily tolerated. Vulcanized. Thereby, the opening on the lower side in the axial direction of the second mounting bracket 14 is
It is covered by the diaphragm 58 in a fluid-tight manner.

A thin seal rubber layer 60 integrally formed with the diaphragm 58 is vulcanized and bonded to the second mounting member 14, and the inner peripheral surfaces of the large-diameter cylindrical portion 52 and the small-diameter cylindrical portion 54 are formed. The whole is covered with a seal rubber layer 60.

The second mounting member 14 is externally inserted into the integrally vulcanized molded product of the main rubber elastic body 16, and the large-diameter cylindrical portion 52 of the second mounting member 14 is externally inserted into The large-diameter cylindrical portion 52 is externally fitted and fixed to the metal sleeve 30 by being reduced in diameter by processing or the like. The lower end surface in the axial direction of the metal sleeve 30 is in contact with the step portion 50 of the second mounting member 14, whereby the metal sleeve 3
0 is axially positioned with respect to the second mounting member 14. In addition, the metal sleeve 30 and the second fitting 14
The seal rubber layer 60 is sandwiched between the fitting surfaces of the seals.

When the second mounting member 14 is externally fitted and fixed to the metal sleeve 30, the second mounting member 1
4 is covered with the main rubber elastic body 16 in a fluid-tight manner, so that the second fitting 1
At the bottom of 4, a fluid chamber 80 in which an incompressible fluid is sealed is formed. In addition, as the sealed fluid, for example, water, alkylene glycol, polyalkylene glycol, silicone oil, or a mixture thereof can be adopted. In particular, an anti-vibration effect based on a resonance effect of the fluid through an orifice passage described later is effective. In order to obtain a low viscosity fluid, it is desirable to employ a low-viscosity fluid having a viscosity of 0.1 Pa · s or less.

In the fluid chamber, a partition member 70 having a substantially disk shape as a whole is disposed so as to extend in a direction perpendicular to the axis. The partition member 70 is formed by superposing a thin disk-shaped lid member 74 on an upper surface of a thick disk-shaped partition member 72, and an outer peripheral edge of the partition metal member 72 and the lid member 74. Are stacked in close contact with each other and sandwiched between the step portion 50 of the second mounting member 14 and the axial lower end surface of the outer peripheral edge of the main rubber elastic body 16, thereby forming the second mounting member. 14 is fixedly assembled. Thereby, the fluid chamber 80
Is divided into a fluid-tight upper and lower part by a partition member 70. Thus, a pressure receiving chamber 76 as a main liquid chamber is formed above the partition member 70, while a pressure receiving chamber 76 is formed below the partition member 70. , An equilibrium chamber 78 as a sub-liquid chamber is formed. The pressure receiving chamber 76 has a part of a wall portion formed of the main rubber elastic body 16, and a pressure fluctuation is generated based on the elastic deformation of the main rubber elastic body 16 at the time of vibration input. The equilibrium chamber 78 has a part of a wall formed of a diaphragm 58 so that a change in volume based on the deformation of the diaphragm 58 is easily allowed.

Further, the partitioning member 70 is formed with a concave groove 82 which is opened on the outer peripheral surface and extends in the outer peripheral part in the circumferential direction with a length of less than one round, and the opening of this concave groove 82 is formed by the second groove. The small-diameter cylindrical portion 54 of the mounting bracket 14 is covered in a fluid-tight manner. As a result, the outer peripheral portion of the partition member extends in the circumferential direction, and one end in the circumferential direction is connected to the pressure receiving chamber 76 through the communication hole 84, and the other end in the circumferential direction is connected to the equilibrium chamber 7 through the communication hole 85.
8, a first orifice passage 86 is formed, through which the fluid flow between the pressure receiving chamber 76 and the equilibrium chamber 78 is allowed. In the present embodiment, the first orifice passage 86 is formed such that a high damping effect is exerted in a low frequency range corresponding to an engine shake based on the resonance action of the fluid caused to flow through the first orifice passage 86. The length and cross-sectional area are adjusted.

Further, a circular central recess 88 opening upward is formed in the center of the partitioning member 72, and a movable rubber plate 90 having a disk shape of a predetermined thickness is formed in the central recess 88. The opening of the central recess 88 is covered with the cover fitting 74 while being accommodated. The movable rubber plate 90
An annular support portion 94 thicker than the central portion is provided on the outer peripheral edge, and the annular support portion 94 is provided with the partition metal member 72 and the lid metal member 7.
4 allows a predetermined amount of axial elastic deformation in the central portion within the central recess 88. Further, a plurality of through holes 9 are formed in both axial side walls of the central recess 88 formed by the partition fitting 72 and the lid fitting 74.
6, the hydraulic pressure in the pressure receiving chamber 76 and the equilibrium chamber 78 is applied to the upper and lower surfaces of the movable rubber plate 90 disposed in the central recess 88 through these through holes 96. ing. Then, the movable rubber plate 90 is elastically deformed based on the pressure difference between the pressure receiving chamber 76 and the equilibrium chamber 78 exerted on the upper and lower surfaces of the movable rubber plate 90, and the amount corresponding to the elastic deformation amount of the movable rubber plate 90 is obtained. , A through hole 96 and a central recess 88 formed in the partitioning member 72 and the lid member 74, respectively.
Between the pressure receiving chamber 76 and the equilibrium chamber 78 is substantially generated, whereby the pressure fluctuation in the pressure receiving chamber 76 is reduced or absorbed. In particular, in this embodiment, the elastic deformation of the movable rubber plate 90 and the abutment of the movable rubber plate 90 against the inner surface of the central recess limit the amount of elastic deformation of the movable rubber plate 90, so that high-frequency small amplitude such as muffled sound is generated. During the vibration input, the pressure fluctuation in the pressure receiving chamber 76 can be advantageously absorbed or reduced based on the elastic deformation of the movable rubber plate 90, while the vibration input of the movable rubber plate 90 By limiting the amount of elastic deformation, an effective pressure change is caused in the pressure receiving chamber 76.

Further, since the second mounting member 14 is externally fitted and fixed to the metal sleeve 30, the metal sleeve 3
0 is covered with the second mounting member 14 in a fluid-tight manner, so that a pair of pockets 42, 4 are provided.
The two openings are covered to form a pair of working liquid chambers 98, 98 each containing an incompressible fluid. In addition, the same incompressible fluid as the pressure receiving chamber 76 is sealed in each of the pair of working liquid chambers 98, 98.

Further, an orifice member 100 is provided in one working liquid chamber 98 in a housed state. The orifice member 100 is formed of a hard material such as a synthetic resin or a metal in a semicircular arc shape or a semicylindrical shape. It is arranged along the inner peripheral surface of the metal fitting 14, and both ends in the circumferential direction are supported by the circumferential groove 32 of the metal sleeve 30. The rubber filled rubber 36 filled in the circumferential groove 32 of the metal sleeve 30 is formed with a fitting groove 102 extending in a circumferential direction at a central portion in the axial direction. Orifice member 100
The orifice member 100 is fixedly attached to the metal sleeve 30 by fitting the both ends in the circumferential direction of the orifice.

The orifice member 100 is formed with a concave groove 104 which is open to the outer peripheral surface and extends continuously from near one end in the circumferential direction to the other end.
In the vicinity of the peripheral end on the closed side of the hole 04, a through hole 106 penetrating through the bottom wall of the groove 104 and opening to one working liquid chamber 98.
Is formed, and the circumferential end on the opening side of the concave groove 82 is connected to the other working fluid chamber 98 in which the orifice member 100 is not disposed through the fitting groove 102 formed in the one filling rubber 36. It is communicated to. Then, the concave groove 104 is covered with the second mounting member 14 in a fluid-tight manner, so that a second orifice passage 108 that connects the pair of working liquid chambers 98 with each other is formed. In the present embodiment, a high damping effect is exerted on low-frequency vibrations of an engine shake or the like based on the resonance action of the fluid which is caused to flow between the pair of working fluid chambers 98, 98 through the second orifice passage 108. Thus, the length and the cross-sectional area of the second orifice passage 108 are adjusted.

For example, as shown in FIG. 1, the engine mount 10 of the present embodiment having the above-described structure has the second mounting member 14 press-fitted and fixed to the cylindrical bracket 110, and At a mounting leg 112 extending downward from the second mounting bracket 14 of the mold bracket 110 in the axial direction, the mounting bracket 112 is mounted on an automobile body 114 such as a tire house and fixed by bolts or the like, so that a mounting center axis is formed. The first mounting bracket 12 is fixed to a power unit (not shown) by bolts or the like while the first and second mounting brackets 12 and 14 are fixed to the vehicle body in a state in which the central axes of the first and second mounting brackets 12 and 14 extend substantially vertically. As a result, the power unit is supported on the body 114 by vibration isolation. In this mounting state, the power unit support load is applied in the vertical direction between the first mounting bracket 12 and the second mounting bracket 14, and the main rubber elastic body 16 is elastically deformed by a predetermined amount.

In particular, in the case of an FF horizontal engine, both sides of the power unit in the vehicle left-right direction, in which the crankshaft extends, are respectively positioned substantially on the inertia main shaft, and a pair of working fluid chambers 98 are provided. , 98 are disposed so as to face each other in the vehicle front-rear direction.

When a substantially vertical vibration load is input between the first mounting member 12 and the second mounting member 14 in such a mounted state, the space between the pressure receiving chamber 76 and the equilibrium chamber 78 is provided. A relative pressure difference will be generated, and if the input vibration is a low-frequency large-amplitude vibration such as an engine shake,
The high damping effect is exerted based on the resonance action of the fluid flowing through the first orifice passage 86, and when the input vibration is a high-frequency small-amplitude vibration such as a muffled sound, the movable rubber plate 90 is elastically deformed. As a result, the pressure fluctuation in the pressure receiving chamber 76 is absorbed and reduced, and the vibration isolation effect by the low dynamic spring action is exhibited.

On the other hand, the first mounting bracket 1
When a substantially horizontal vibration load directed in the vehicle front-rear direction is input between the second mounting bracket 14 and the second mounting bracket 14, the pair of working fluid chambers 9
As a result, a relative pressure difference is generated between the first and second orifices 108 and 98. Based on the resonance effect of the fluid flowing through the second orifice passage 108, an effective damping effect against low-frequency and large-amplitude vibrations such as engine shakes. Can be exhibited.

There, such an engine mount 1
0, the first mounting bracket 12 and the second mounting bracket 1
Rubber elastic body 16 for elastically connecting 4 at its radially opposed surface
Is substantially divided by a pair of working liquid chambers 98, 98 into an axial inner wall portion 46 and an axial outer wall portion 44 located on both sides in the radial direction, and is further divided than the axial outer wall portion 44. Since the axial inner wall portion 46 is thicker and the radial spring constant is set to be larger, the main rubber elastic body 1
6, the center of elastic support in the radial direction of the first mounting member 12 and the second mounting member 14 in the radial direction is set to be lower in the axial direction, and is positioned further below the axially intermediate portion of the main rubber elastic body 16. Have been.

Therefore, the center of the elastic support in the direction perpendicular to the axis of the engine mount 10 can be set so as to be largely deviated axially below the mounting fixture 22 of the first mounting bracket 12. The main body rubber elastic body 1
Since the center of elastic support can be set below the axial center of the engine mount 6, the body 1 of the engine mount 10
Even if the mounting portion of the first mounting bracket 12 with respect to the power unit is displaced upward from the main axis of inertia of the power unit even when the mounting portion on the tire housing is mounted on the tire house, the center of elastic support of the power unit by the engine mount 10 will be described. Can be set closer to the inertia main axis, and the vibration-proof support characteristics of the power unit by the engine mount 10 can be improved.

Further, in the engine mount 10 having the above-described structure, the rubber elasticity of the main body serving as a relative load application point of the vibration load in the direction perpendicular to the axis input from the first mounting member to the second mounting member 14. Since the center of elasticity of the body 16 can be set at a position sufficiently penetrating axially downward from the axially upper opening of the second mounting member 14, the second mounting member 14 via the cylindrical bracket 110 can be set. The distance from the fixed portion to the vehicle body 114 to the load application point can be kept small. As a result, the moment acting on the fixed portion of the second mounting member 14 to the vehicle body 114 is reduced. As a result, the strength characteristics and durability at such a fixed portion can be improved.

Further, in the engine mount 10 having the above-described structure, the axial lower wall portions 46 of the pair of working fluid chambers 98 are set to have large wall thicknesses. The expansion spring constant of the configured pressure receiving chamber 76 is increased, and the escape of pressure fluctuations generated in the pressure receiving chamber 76 when the axial vibration load is input to the working liquid chamber 98 is effectively suppressed. The pressure fluctuation between the pressure receiving chamber 76 and the equilibrium chamber 78 is efficiently generated, and the amount of fluid flowing through the first orifice passage 86 is advantageously ensured. Can be exhibited more effectively.

Further, in the engine mount 10 of the present embodiment, both the pressure receiving chamber 76 and the equilibrium chamber 78 in which relative pressure fluctuation occurs when an axial vibration is input,
Since a pair of working liquid chambers 98, 98 in which relative pressure fluctuations are generated at the time of radial vibration input are formed independently, the volumes of the respective chambers 76, 78, 80, 98 are set to be large and the first is set. And second orifice passages 86, 108
The flow amount of fluid flowing through the pressure chamber can be secured large, and effects such as easy tuning of vibration damping characteristics by adjusting the wall spring characteristics of the pressure receiving chamber 76, the equilibrium chamber 78, and the working liquid chamber 98 can be exhibited. .

FIGS. 3 and 4 show an automobile engine mount 115 according to a second embodiment of the present invention. In the present embodiment, members and portions having the same structure as the first embodiment are denoted by the same reference numerals as those in the first embodiment in the drawings, and their detailed descriptions are given. Description is omitted.

In the engine mount 115 of this embodiment, a step 118 is formed at a position deviated above the center of the metal sleeve 30 in the axial direction.
The lower part in the axial direction across the step part 118 is a small diameter part 119, and the upper part in the axial direction is a large diameter part 120. That is, the metal sleeve 30 of the present embodiment has a structure in which the peripheral groove 32 is formed to extend to the lower end in the axial direction, as compared with the metal sleeve of the first embodiment.

The small diameter portion 1 of the metal sleeve 30
19, the orifice tube member 12 having a cylindrical shape
1 is fitted outside. This orifice tube member 121 is
It has a length in the axial direction extending from the lower end of the metal sleeve 30 to the windows 34, 34 to a height exceeding the central portion of the windows 34, 34, and has a large diameter of the second mounting bracket 14. The lower end portion in the axial direction is fluid-tightly sandwiched between the metal sleeve 30 and the second mounting member 14 over the entire circumference, and is disposed in close contact with the inner peripheral surface of the cylindrical portion. Mounting bracket 1
4 is fixedly assembled.

The orifice cylinder member 121 has a groove 116 extending slightly less than one circumference in the circumferential direction at the axial middle portion.
Are formed, and both ends in the circumferential direction of the concave groove 116 are connected to communication holes 122, 122 formed through the bottom wall 117.
, Are communicated with the respective working liquid chambers 98, 98. Then, the concave groove 116 is used for the second mounting bracket 1.
4 to form a pair of working fluid chambers 9
A second orifice passage 108 which communicates with the second
Are formed.

Then, the engine mount 1 of the present embodiment
15 is also disposed between the power unit and the vehicle body using, for example, a cylindrical bracket or the like, as in the first embodiment, whereby the same vibration damping effect as in the first embodiment is effective. It can be demonstrated in. Here, in particular, in the engine mount 10 of the present embodiment, a cylindrical orifice tube member 121 is adopted,
Since the second orifice passage 108 can be formed to have a length equal to or more than half a circumference in the circumferential direction, the length of the second orifice passage 108 and, consequently, the degree of freedom in tuning the vibration isolation characteristics are greatly increased. Can be improved.

The engine mount 11 of the present embodiment
In 5, the lower end portion of the metal sleeve 30 in the axial direction is a small diameter portion 119, so that the lower wall portions 46 of the working liquid chambers 98, 98 formed by the main rubber elastic body 16 in the axial direction.
However, since the outer diameter is smaller than the axial upper wall portion 44 and the free length in the radial direction is smaller, both the radial spring constant and the expanded spring constant The axial lower wall portion 46 can be set larger, so that the elastic support center of the first mounting member 12 of the main rubber elastic body 16 can be set more efficiently axially downward. As described above, it is possible to further improve the effects such as the improvement of the anti-vibration support performance of the power unit and the improvement of the strength characteristics and durability at the mounting portion of the second mounting bracket 14 to the vehicle body as described above. is there.

The engine mount 11 of the present embodiment is
In 5, the support shaft portion 20 of the first mounting member 14 is sandwiched in a radial direction in which the pair of working liquid chambers 98 and 98 face the wall of the pressure receiving chamber 76 formed by the main rubber elastic body 16. A pair of pocket-shaped recesses 12 located on both sides
3,123 are formed, and these recesses 123,1 are formed.
By making a part of the lower wall portion of the working liquid chambers 98, 98 in the axial direction thinner at 23, the spring ratio in the radial direction (vehicle front-rear direction and left-right direction) orthogonal to each other is set large, The axial spring constant is adjusted.

FIG. 5 shows an automotive engine mount 124 according to a third embodiment of the present invention. In the present embodiment, members and portions having the same structure as the second embodiment are denoted by the same reference numerals as those in the second embodiment in the drawings, and their detailed descriptions are given. Description is omitted. The AA cross section in FIG. 5 appears the same as in FIG. 4 in the second embodiment, and is not illustrated.

In the engine mount 124 of the present embodiment, the second mounting member 14 has a bottomed cylindrical shape composed of only the large-diameter cylindrical portion 52.
A pressure receiving chamber 76 is formed between the bottom wall portion 126 and an opposing surface of the main rubber elastic body 16. In short, the engine mount 10 of the present embodiment does not have the equilibrium chamber employed in the second embodiment.

A circular central through hole 127 is formed in the center of the bottom wall 126 of the second mounting member 14 constituting the wall of the pressure receiving chamber 76.
A movable rubber plate 90 is arranged on the 27 in an extended state. The movable rubber plate 90 has a disk shape of a predetermined thickness, and the outer peripheral edge portion is vulcanized and bonded to the peripheral edge portion of the central through hole 127 so that the central through hole 127 is covered in a fluid-tight manner. ing. In such an arrangement state, the internal pressure and the atmospheric pressure of the pressure receiving chamber 76 are applied to the upper and lower surfaces of the movable rubber plate 90, and the pressure fluctuation is applied to the pressure receiving chamber 76 by the input of the axial vibration load. As a result, the movable rubber plate 90 is elastically deformed to absorb and reduce the pressure fluctuation in the pressure receiving chamber. The movable rubber plate 9
0 is limited by the amount of elastic deformation based on the elasticity of itself, as in the movable rubber plate of the second embodiment,
When the high-frequency small-amplitude vibration is input, the pressure fluctuation in the pressure receiving chamber 76 can be effectively absorbed and reduced, but when the low-frequency large-amplitude vibration is input, an effective pressure fluctuation is generated in the pressure receiving chamber 76.

Further, in this embodiment, as shown in FIGS. 6 and 7, an annular projection 128 is integrally formed at the lower end portion in the axial direction of the orifice member 125. The annular projection 128 has an inner flange shape protruding radially inward from the peripheral edge of the opening of the orifice member 125 on the lower side in the axial direction at a predetermined length, and the inner peripheral edge is formed by the second peripheral edge. The mounting bracket 14 reaches the vicinity of a central through hole formed in the bottom wall portion 126 of the mounting bracket 14. And such an annular projection 128 is
The outer peripheral edge of the annular protrusion 128 is overlapped with the lower end in the axial direction of the metal sleeve 30 and the main rubber elastic body 30 in the second mounting bracket 14 in close contact with the bottom wall 126 of the second mounting bracket 14. It is sandwiched in the axial direction between the bottom wall portions 126 of the metal fittings 14 and is fixed to the second mounting metal fittings 14, and the inner peripheral edge of the annular projection 128 extends into the pressure receiving chamber 76. It is put out and positioned.

Further, the orifice member 125 is formed with a concave groove 116 formed so as to extend in the axially intermediate portion at a length of less than one round in the circumferential direction, similarly to the second embodiment. A pair of divided grooves 129, 129 each extending in the circumferential direction with a length of less than half a circumference are formed at positions spaced apart in the axial direction below the grooves 116. Each of the pair of divided concave grooves 129 extends downward in the axial direction at one end in the circumferential direction, and opens at the inner peripheral edge of the annular protrusion 128 through a radial groove 130 formed in the annular protrusion 128. At the other end in the circumferential direction, it is opened to the inner peripheral surface of the orifice member 125 through a communication hole 132 formed through the bottom wall.

As shown in FIG. 5, the large-diameter cylindrical portion 52 of the second mounting member 14 is fixed to the outer peripheral surface of the cylindrical wall portion of the orifice member 125 and the axially outer surface of the annular projection. The wall portions 126 are superposed in close contact with each other to
9, 129 and the radial grooves 130, 130 are covered in a fluid-tight manner, so that the two first orifice passages 86, 86 for connecting the respective working liquid chambers 98, 98 to the pressure receiving chamber 76 independently of each other are formed. It is formed independently.

In the engine mount 124 of this embodiment having such a structure, in the radial direction (vehicle longitudinal direction)
When the vibration load of the second orifice is input, as in the case of the engine mount of the second embodiment,
When the vibration load in the axial direction is input while the vibration damping effect based on the fluid flow action through
Based on the relative pressure fluctuations created between the pressure receiving chamber and the two working fluid chambers, a fluid flow is generated through the first orifice passages 86, 86 and the first orifice passages 86, 86 are caused to flow. An anti-vibration effect based on the resonance action of the fluid to be flown is exhibited. When an axial vibration in a frequency range higher than the tuning frequency of the first orifice passage 86 is input, an effect of absorbing the pressure fluctuation of the pressure receiving chamber 76 based on the elastic deformation of the movable rubber plate 90 is exerted.

Accordingly, the engine mount 1 of the present embodiment
Also in the engine mount 24, similarly to the engine mount of the second embodiment, it is possible to obtain an effective vibration damping effect based on the flow action of the fluid against the input vibration in the vertical direction and the front and rear direction of the vehicle. In particular, in the present embodiment, since the auxiliary liquid chamber is formed by using the pair of working liquid chambers 98, 98, the entire size of the mount can be made compact.

By reducing the size of the engine mount 124 in the axial direction, the second mounting bracket is attached to the vehicle body at the lower end in the axial direction by using a cylindrical bracket, for example, similarly to the engine mount of the first embodiment. In the case of fixing, the fixing portion of the second mounting member 14 to the vehicle body can be set closer to the center of the support spring of the main rubber elastic body 16, whereby
The reduction of the moment exerted on the fixing portion of the second mounting member 14 to the vehicle body, and the improvement in the strength characteristics and durability of the fixing portion based on the reduction can be more effectively achieved.

Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention
By specific descriptions in these embodiments,
It is not to be construed as limiting.

For example, the specific structure of the first orifice passage and the second orifice passage, the passage length, the passage cross-sectional area, and the like are appropriately determined according to the required vibration isolation characteristics. It is not limited at all. Here, the first orifice passage and / or the second orifice passage can be tuned so as to exhibit an effective vibration damping effect against idling vibration according to required characteristics.

In the above-described embodiment, a part of the wall of the pressure receiving chamber 76 is constituted by the movable rubber plate 90 that absorbs pressure fluctuation in a high frequency range. In the present invention, it is not always necessary.

Further, in the above embodiment, the present invention
Although the present invention has been described with respect to an application to an engine mount for an F-type horizontal engine, the present invention is also applicable to engine mounts having various structures, body mounts, differential mounts, and vibration damping devices for various vibration bodies other than automobiles. It goes without saying that any of them can be applied.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements, and the like can be made, and unless such embodiments depart from the spirit of the present invention.
Both are included in the scope of the present invention,
Needless to say.

[0068]

As is apparent from the above description, in the fluid filled type vibration damping device having the structure according to the present invention, the elastic center for the vibration load input in the direction perpendicular to the axis is defined by the rubber elastic body of the main body. It is possible to set the support shaft so as to be deviated toward the protruding tip side thereof, whereby the support shaft is fixed to the first mounting member projecting vertically upward from the cylindrical portion of the second mounting member. It becomes possible to set the elastic support center of the vibration-proof object inside the second mounting member.

Therefore, even when the fixing positions of the first mounting member and the second mounting member with respect to the vibration isolating object are largely separated in the axial direction of the vibration isolating device, the vibration load input in the direction perpendicular to the axis is used. As a result, the moment exerted on the fixing positions of the first and second mounting members is suppressed, and the strength characteristics and durability at the fixing portion can be advantageously secured.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing an engine mount as a first embodiment of the present invention, and is a view corresponding to an II section in FIG. 2;

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is an explanatory longitudinal sectional view showing an engine mount as a second embodiment of the present invention, and is a III-II in FIG. 4;
It is a figure corresponding to I section.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is an explanatory longitudinal sectional view corresponding to FIG. 3, showing an engine mount as a third embodiment of the present invention.

FIG. 6 is a front view showing an orifice member constituting the engine mount shown in FIG.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6;

[Explanation of symbols]

 10, 115, 124 Engine mount 12 First mounting bracket 14 Second mounting bracket 16 Main rubber elastic body 20 Support shaft 44 Upper axial wall 46 Lower axial wall 76 Pressure receiving chamber 78 Equilibrium chamber 86 First Orifice passage 98 Working fluid chamber 108 Second orifice passage

Claims (8)

[Claims] 1. A first mounting member is spaced apart from one cylindrical side of an opening of a cylindrical portion formed on a second mounting member, and enters the cylindrical portion of the second mounting member. A support shaft extending in the axial direction of the cylindrical portion is provided on the first mounting member, and the support shaft of the mounting member and the cylindrical portion of the second mounting member are elastically connected by a main rubber elastic body. At least, by closing the one axial opening of the cylindrical portion with the main rubber elastic body in a fluid-tight manner, it is positioned axially inward of the first mounting member in the cylindrical portion. A main liquid chamber in which a part of a wall portion is formed by the main rubber elastic body is formed, and the main liquid chamber is formed when an axial vibration is input between the first mounting member and the second mounting member. A sub-fluid chamber in which relative pressure fluctuations occur is formed, and an incompressible fluid is sealed in the main liquid chamber and the sub-fluid chamber. In a fluid filled type vibration damping device having a first orifice passage communicating a main liquid chamber and a sub liquid chamber with each other, the support shaft portion of the first mounting member is formed at a right angle to the inside of the main rubber elastic body. A pair of working fluid chambers are provided on both sides sandwiched in the direction and are each extended in the circumferential direction by a length equal to or less than half the circumference, and the incompressible fluid is sealed in the pair of working fluid chambers, and the pair of working fluids While forming a second orifice passage which communicates the chambers with each other, the spring constant in the direction perpendicular to the axis of the axially inner elastic wall portion of each working liquid chamber formed by the main rubber elastic body is determined by A fluid-filled type vibration damping device characterized by having a spring constant in a direction perpendicular to an axis of an elastic wall portion outwardly in an axial direction of a liquid chamber. 2. The axial thickness of the elastic wall portion in the axial direction of each of the working liquid chambers is larger than the axial thickness of the elastic wall portion of the working liquid chamber on the outside in the axial direction. The fluid filled type vibration damping device according to claim 1. 3. A free length of a portion of the elastic body of the main body, which constitutes an elastic wall portion of the pair of working fluid chambers, which is located outward in the axial direction, between the first mounting member and the second mounting member. The free length between the first mounting member and the second mounting member of a portion forming the elastic wall portion inward in the axial direction of the pair of working liquid chambers is smaller than that of the first mounting member. The fluid filled type vibration damping device as described in the above. 4. The vulcanization bonding of the first mounting member to the main rubber elastic body, and the support shaft portion of the first mounting member is sandwiched between the main rubber elastic body in a direction perpendicular to the axis. A pair of pockets is formed on both sides of the outer peripheral surface, and a metal sleeve is further vulcanized and bonded to the outer peripheral surface of the rubber elastic body. A pair of pockets is opened through the windows to form a pair of pockets, and the pair of pockets is fluid-tightly closed by externally fixing the cylindrical portion of the second mounting member to the metal sleeve. The fluid filled type vibration damping device according to any one of claims 1 to 3, wherein the pair of working liquid chambers is formed by covering with a cover. 5. A stepped portion is provided at an intermediate portion in the axial direction of the metal sleeve, and a stepped portion is provided at an intermediate portion in the axial direction of the pair of working liquid chambers. The inner annular portion vulcanized and bonded to the outer peripheral surfaces of the elastic wall portions inward in the axial direction of the pair of working liquid chambers has a small diameter, and a cylindrical orifice member is extrapolated to the inner annular portion of the metal sleeve. Then, the orifice member is sandwiched between the inner annular portion and the cylindrical portion of the second mounting member,
The second orifice, which extends and arranges the orifice member along the inner peripheral surface of the cylindrical portion to the pair of working liquid chambers, and connects the pair of working liquid chambers to each other by the orifice member. The fluid filled type vibration damping device according to claim 4, wherein a passage is formed. 6. An axially intermediate portion of the cylindrical portion of the second mounting member is partitioned by a partition member, and the main liquid chamber is formed on one side in the axial direction with the partition member interposed therebetween. The fluid filling according to any one of claims 1 to 5, wherein the auxiliary liquid chamber is formed on the other side in the axial direction with the member interposed therebetween, and a part of the wall of the auxiliary liquid chamber is formed of a flexible film. Type anti-vibration device. 7. In the pair of working fluid chambers, the expansion spring constant of the elastic wall portion on the axially outer side is made smaller than the expansion spring constant of the elastic wall portion on the axially inner side, and the first orifice passage is provided. The fluid filled type vibration damping device according to any one of claims 1 to 5, wherein the main liquid chamber is communicated with the pair of working liquid chambers, whereby the sub liquid chamber is constituted by the pair of working liquid chambers. apparatus. 8. A structure in which the first mounting member is attached to one member to be vibration-isolated at a distal end portion protruding outward in the axial direction from a cylindrical portion of the second mounting member. The second mounting member is attached to the other member to be vibration-isolated at the axial end of the cylindrical portion opposite to the side on which the first mounting member is provided. 8. The fluid filled type vibration damping device according to any one of 1 to 7.