JPH0324914Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a fluid-filled anti-vibration bushing, and more particularly to a fluid-filled anti-vibration bushing that can effectively exhibit a vibration damping function based on the flow action of the enclosed fluid. be.

(Prior Art) Conventionally, in vehicles such as automobiles, a predetermined anti-vibration support has been used as a type of anti-vibration support provided at the attachment or connection portion of the suspension system or drive train engine to the vehicle body, such as the body or frame. A vibration isolating bushing is known which is attached to a mounting shaft and mainly damps or blocks vibrations in a direction perpendicular to the shaft.

By the way, in recent years, as one type of vibration-proof bushing, a fluid-filled bushing has been developed which combines a vibration-insulating effect based on the elastic deformation of rubber with a vibration-damping effect based on the flow effect of fluid, in order to particularly enhance its vibration-damping effect. For example, in Japanese Patent Publication No. 48-36151 and Japanese Patent Publication No. 52-16554, a cylindrical rubber elastic body is interposed between an inner cylinder member and an outer cylinder member. A first fluid chamber and a second fluid chamber, each of which is filled with a predetermined incompressible fluid, are formed in the rubber elastic body, and the fluid chambers are communicated with each other through an orifice. Structures have been proposed that allow fluids to flow with each other.

The first and second fluid chambers in a fluid-filled anti-vibration bushing having such a structure are usually
The first and second fluid chambers are formed at positions facing each other in the vibration input direction across the inner cylindrical metal fitting, and due to a relative change in the volumes of the first and second fluid chambers during vibration input,
Fluid flow through the orifice is adapted to occur.

(Problem) However, in the conventional fluid-filled anti-vibration bushing having the structure as described above, vibrations are Since there are parts where the deformation during input is caused only by compressive deformation,
There was a limit to softening the spring characteristics of the rubber elastic body in the vibration input direction. However, if the wall thickness is made thinner in order to soften the spring characteristics of such parts, bulges to the outside will occur when vibration is input, and the fluid flow due to the volume change of the fluid chamber as described above will occur. There is a risk that the effect may not be expressed effectively.

Therefore, the relative change in the volume of the first and second fluid chambers and the amount of movement of fluid through the orifice based on the relative change in the volume of the first and second fluid chambers upon vibration input cannot be sufficiently generated, and a sufficient damping effect cannot be obtained. However, the problem was that it was said that it was difficult to do so.

(Solution Means) Here, the present invention was made against the background of the above-mentioned circumstances, and its features are (a) an inner cylinder member, and (b) an outer side of the inner cylinder member. (c) an outer cylindrical member having a window, which is arranged concentrically or eccentrically to the outer cylindrical member; and (c) a seal sleeve fitted onto the outer peripheral surface of the outer cylindrical member so as to cover the window of the outer cylindrical member. (d) in a state where two cavities are formed that are located between the inner cylinder member and the outer cylinder member and penetrate in the axial direction on both sides of the inner cylinder member; (e) a rubber elastic body having two connecting portions each extending in the radial direction with a central angle forming a substantially V-shaped cross section; a pair of pressure receiving chambers formed by respectively covering pocket portions opening outward through the window portion of the outer cylinder member with the seal sleeve; and (f) the inner cylinder member and the outer cylinder member. a variable-volume container located in one of the spaces formed between the two, at least a portion of which is defined by a flexible thin film, and which opens outward through the window of the outer cylinder member. an equilibrium chamber formed by covering a recess with the seal sleeve; (g) orifice means for communicating the equilibrium chamber with the pair of pressure receiving chambers, and (h) the pressure receiving chamber. and an incompressible fluid sealed so as to fill each equilibrium chamber.

(Function/Effect) In the fluid-filled vibration-isolating bushing having the structure according to the present invention, when vibration is input between the inner cylinder member and the outer cylinder member, the vibration of the inner cylinder member and the outer cylinder member is reduced. Since the deformation in the connecting rubber elastic bodies does not have a part that is generated only by compressive deformation, and the deformation occurs as shearing and compressive deformation in the connecting parts of the rubber elastic bodies, vibration input The spring characteristics can be set to be sufficiently soft so that a change in the volume of the pressure receiving chamber formed in the connecting portion can be effectively generated at the time of the connection, and therefore the spring characteristics between the pressure receiving chamber and the equilibrium chamber can be set to be soft enough. The vibration damping effect based on the flow action of the fluid through the orifice can be extremely effectively exerted.

(Example) In order to clarify the present invention more specifically, reference will be made below to the drawings for an example in which the present invention is applied to an engine mount used for anti-vibration support of a power unit of an automobile. I will explain this in detail.

First, FIG. 1 shows a cross-sectional view of a fluid-filled engine mount assembly, and FIGS. 2 and 3 show different longitudinal cross-sectional views thereof.

In these figures, 10 and 12 are a thick cylindrical inner metal fitting as an inner cylinder member and a cylindrical outer metal fitting as an outer cylinder member, which are arranged eccentrically from each other, Rubber body 1 as a rubber elastic body interposed between them
4 and are elastically connected. Further, a metal sleeve 16 serving as a sealing sleeve is fitted onto the outer circumferential surface of the outer cylinder fitting 12. The engine mount in this embodiment is fitted onto the outer peripheral surface of the metal sleeve 16 into a cylindrical member provided on either the power unit side including the engine or the vehicle body side, and is attached to the inner cylindrical metal fitting. In the inner hole 18 of 10,
The power unit is fitted onto a mounting shaft provided on the other side of the power unit or the vehicle body, thereby supporting the power unit with respect to the vehicle body. The inner cylindrical metal fitting 10 and the outer cylindrical metal fitting 12 are arranged to be positioned substantially concentrically when the weight of the power unit is applied.

By the way, in the engine mount having such a structure, the inner cylinder fitting 10, the outer cylinder fitting 12, and the rubber body 14 are generally formed as an integrally vulcanized molded product 15, as shown in FIGS. 4 to 6. configured. There, the main body portion of the rubber body 14 has two connections extending in the radial direction from the inner tube fitting 10 to the outer tube fitting 12, which are formed with a central angle that forms a generally V-shaped cross section as a whole. Part 2
0,20, and their connecting part 2
0,20, the inner cylindrical metal fitting 10 and the outer cylindrical metal fitting 12
are integrally connected.

In addition, a pocket portion 22 having a predetermined volume that opens on the outer peripheral surface is formed in each of these connecting portions 20, 20, and a restraining ring 24 is embedded in the outer peripheral portion of each connecting portion 20. The pocket portion 22 is integrally attached by vulcanization adhesive or the like, and the outward bulge of the peripheral wall portion of the pocket portion 22 is restricted.

Further, the rubber body 14 is not present in the cylindrical space between the inner tube fitting 10 and the outer tube fitting 12 other than where the connecting portions 20, 20 are located, and therefore By partitioning the cylindrical space in the circumferential direction by the connecting parts 20, 20, the first and second spaces 46, 48, which respectively penetrate in the axial direction, face each other with the inner cylindrical fitting 10 interposed therebetween. It is formed in

In the second space 48, a bulging deformation is provided at a position equidistantly spaced in the circumferential direction from the opening of each pocket portion 22 provided in the two connecting portions 20, 20. A recess 28 is defined by a thin walled portion 26 and is open to the outer circumferential surface. As is clear from FIGS. 4 and 5, the thin wall portion 26 is integrally formed with the rubber body 14 that forms the connecting portions 20, 20, and 2
0 and the thin wall portion 26 are each connected by a similar portion 30 having a predetermined thickness and forming a part of the rubber body 14.

Furthermore, on the outer circumferential surfaces of the circumferential parts 30 and 30 of the rubber body 14, there are holes extending in the circumferential direction from the opening of the pocket part 22 provided in the connecting part 20 to the opening of the recess 28, respectively. A circumferential groove 32 is formed. As shown in FIGS. 1 and 3, an arc-shaped orifice fitting 34 having a U-shaped cross section is fitted into each circumferential groove 32. Note that the flow cross-sectional area and length of this orifice fitting 34 are tuned with respect to the input frequency for the purpose of vibration damping.

On the other hand, with such a rubber body 14, the inner cylinder fitting 10
As shown in FIGS. 4 to 6, the outer cylindrical metal fitting 12 connected to the
Pocket portions 22, 22 and recess 28 formed in 4
and a window portion 36 having a shape corresponding to the circumferential grooves 32, 32.
are formed, thereby forming pockets 22, 22, recesses 28 and circumferential grooves 32, 32.
are opened outward through the window portions 36, respectively.

The integrally vulcanized molded product 15 having such a structure is vulcanized and molded with its rubber body 14.
By fitting the metal sleeve 16 into the outer cylindrical fitting 12 with the orifice fitting 34 fitted into the circumferential groove 32, the window portion 36 and eventually the pocket portions 22, 22 , recess 2
8 and circumferential grooves 32, 32 (orifice fittings 34,
34) are respectively fluid-tightly closed, so that the pair of pressure receiving chambers 38, 38 are formed by the pocket portions 22, 22, and the equilibrium chamber 40 is formed by the recess 28. Orifices 42, 42 are formed, respectively, which connect the respective pressure receiving chambers 38, 38 to the equilibrium chamber 40 through the circumferential grooves 32, 32 (orifice fittings 34, 34). In addition, in the case of the metal sleeve 16 in this embodiment, a sealing rubber layer 44 is integrally formed over the entire inner circumferential surface of the metal sleeve 16, thereby sealing the pressure receiving chamber 38, the equilibrium chamber 40, and the orifice 42. Good sealing performance can be ensured in the case.

In addition, in this example, the above-mentioned integrally vulcanized molded product 15
As the fitting operation of the metal sleeve 16 is performed in a predetermined incompressible fluid, the pressure-receiving chamber 38, the equilibrium chamber 40 and the orifice 42 are
A predetermined incompressible fluid such as water, alkylene glycol, polyalkylene glycol, silicone oil, or low molecular weight polymer is enclosed.

Further, the metal sleeve 16 is fixed to the outer cylinder fitting 12 by being subjected to an eight-way drawing process, and after the metal sleeve 16 is fitted, a predetermined shape may be applied as necessary. The diameter is reduced by passing it through a die, and the outer dimensions are set to desired dimensions.

In the case of an engine mount having such a structure, as described above, the inner cylinder fitting 10
The main vibration input direction is shown in Fig. 1. In other words, the first and second spaces 46, 48
The engine mount is arranged in such a manner that the vibration input direction is arranged in the vibration input direction.

Therefore, for such an engine mount,
When a vibration load is input in the direction of arrow P, the volume of the pressure receiving chamber 38 decreases and increases due to elastic deformation of the connecting portions 20, 20 constituted by the rubber body 14, while the volume of the equilibrium chamber 40 decreases and increases. Since the volume of the pressure chamber 38 can be easily changed by the thin wall 26 that defines it, the pressure chamber 38 is connected to the equilibrium chamber 40 through an orifice 42 that connects the pressure chamber 38 and the equilibrium chamber 40. side and then in the opposite direction, the incompressible fluid enclosed in the pressure receiving chamber 38 and the equilibrium chamber 40 is caused to flow alternately, and therefore in the orifice 42. The flow effect of the incompressible fluid provides a damping effect on input vibrations.

Here, the deformation of the connecting parts 20, 20 at the time of such vibration input occurs as shearing and compressive deformation, and is caused between the inner cylindrical metal fitting 10 and the outer cylindrical metal fitting 12 located in the vibration input direction. are first and second cavities 4 passing through in the axial direction.
6 and 48 are provided, the rubber body 14 is not present, and there is no part where only compression deformation occurs, so that the spring characteristics can be set to be sufficiently soft. As a result, the volume of the pressure receiving chamber 38 formed within the connecting portion 20 can be extremely effectively changed, so that a sufficient flow amount of the sealed fluid through the orifice 42 can be effectively obtained. Therefore, the vibration damping effect based on the fluid flow effect through the orifice 42 between the pressure receiving chamber 38 and the equilibrium chamber 40 can be extremely effectively exhibited, and excellent vibration damping characteristics can be exhibited.

Furthermore, in the engine mount according to this embodiment, a restraint ring 24 is integrally disposed at a portion of the connecting portion 20 that corresponds to the wall of the pressure receiving chamber 38 to prevent outward expansion of the wall. Because it effectively prevents buckling and buckling, it also has the effect of stably exhibiting its excellent vibration damping effect.

Above, one embodiment of the fluid-filled anti-vibration bushing structured according to the present invention has been described in detail.
This is a literal illustration, and the present invention should not be construed as being limited to this specific example.

For example, in the embodiment, the orifice 42 connecting the pressure receiving chamber 38 and the equilibrium chamber 40 is connected to the circumferential groove 32 formed on the outer circumferential surface of the circumferential portion 30 of the rubber body 14.
Although the orifice fitting 34 is fitted into the inside, the configuration is not limited to this, and the outer circumferential surface of the circumferential portion 30 of the rubber body 14 is covered with the outer cylindrical fitting 12. It is also possible to form the groove by covering the groove formed on the outer peripheral surface of the outer cylindrical fitting 12 with the metal sleeve 16, and it is also possible to provide a plurality of such orifices.

Furthermore, in the embodiment, the equilibrium chamber 40 is
Although it is formed in the second cavity 48 having a larger cross-sectional area, it is also possible to provide it in the other first cavity 46.

Furthermore, in the embodiment described above, the restraining ring 24 was disposed at the connecting portion 20 of the rubber body 14;
Such a restraining ring 24 does not necessarily need to be provided.

Although not listed in detail, the present invention can be implemented with various changes, modifications, improvements, etc., and as long as such embodiments do not depart from the spirit of the present invention, It goes without saying that this is included within the scope of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a fluid-filled engine mount as an embodiment of the present invention, and FIGS. 2 and 3 are a cross-sectional view and a cross-sectional view, respectively, of FIG. 1. Further, FIG. 4 is a cross-sectional view of an integrally vulcanized molded product used in such an engine mount, and FIGS. 5 and 6 are a cross-sectional view and a cross-sectional view, respectively, in FIG. 4. 10...Inner cylinder metal fitting, 12...Outer cylinder metal fitting, 14...
...Rubber body, 16...Metal sleeve, 20...Connection part, 22...Pocket part, 26...Thin wall part, 2
8... Recess, 34... Orifice fitting, 36...
Window section, 38...Pressure receiving chamber, 40...Equilibrium chamber, 42...
...Orifice, 46...first void, 48...second void.

Claims (1)

[Claims for Utility Model Registration] An inner cylindrical member; an outer cylindrical member having a window portion arranged concentrically or eccentrically on the outside of the inner cylindrical member; , a seal sleeve fitted onto the outer peripheral surface of the outer cylindrical member, and two seal sleeves located between the inner cylindrical member and the outer cylindrical member and extending axially through both sides of the inner cylindrical member. In the state where two voids are formed,
a rubber elastic body having two connecting portions each extending in the radial direction with a central angle forming a substantially V-shaped cross section, which connects the two members; a pair of pressure receiving chambers formed by respectively covering pocket portions opening outward through the window portion of the outer cylinder member with the seal sleeve; and between the inner cylinder member and the outer cylinder member. a recess with a variable volume, located in one of the cavities formed in the outer cylinder member, at least a portion of which is defined by a flexible thin film, and which opens outward through the window of the outer cylinder member; , an equilibrium chamber formed by covering with the seal sleeve; orifice means for communicating the equilibrium chamber with the pair of pressure receiving chambers, and filling the pressure receiving chamber and the equilibrium chamber, respectively. A fluid-filled anti-vibration bushing comprising: an enclosed incompressible fluid.