JPH0434016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a top support for elastically connecting a piston rod of a shock absorber to a vehicle body in a vehicle suspension system, and particularly for effectively isolating small displacement vibrations. The present invention relates to an atsupa support that can effectively attenuate large-displacement vibrations.

BACKGROUND ART A strut type vehicle suspension system is known as one type of vehicle suspension system that uses a shock absorber as a suspension link. In such a suspension system, one end of the shock absorber is connected to the wheel side, while the piston rod of the shock absorber is usually elastically connected to the vehicle body side via an upper support. A typical example is the so-called McPherson strut type, which is often used as a suspension system for the front wheels of a vehicle and has a coil spring placed outside the shock absorber.

The above-mentioned atsupa support includes an outer metal fitting attached to the wheel side, an inner metal fitting to which the shock absorber piston rod is attached, and a rubber elastic body interposed between the outer metal fitting and the inner metal fitting. It plays a role in suppressing vibrations from the wheels that cannot be absorbed by shock absorbers and coil springs, self-excited vibrations of coil springs, etc. from being transmitted to the vehicle body.

By the way, this type of Atsupa support has very good isolation characteristics that effectively isolate such vibrations while maintaining soft spring characteristics (low dynamic spring constant) against small displacement and high frequency vibration input. In response to a low-frequency vibration input at a high temperature, a damping characteristic that quickly damps it and suppresses a large displacement between the outer metal fitting and the inner metal fitting is required. Since these two vibration-proofing properties were attempted to be achieved only by the vibration-damping effect of the rubber elastic body, limitations naturally arose, and it was difficult to satisfy both of the required properties. It was hot.

Purpose of the Invention The present invention has been made in view of the above circumstances, and its purpose is to exhibit high isolation ability against high-frequency vibrations with small displacements, and to reduce vibrations with large displacements. An object of the present invention is to provide an atsupa support capable of obtaining a large damping force against frequency vibrations.

Structure of the Invention In order to achieve such an object, the present invention provides an atsupa support including an outer metal fitting, an inner metal fitting, and a rubber elastic body as described above, in which a support is provided between the inner metal fitting and the outer metal fitting. a pressure-receiving chamber whose volume can be reduced by relative displacement between the inner metal fitting and the outer metal fitting; An equilibrium chamber is formed by an enclosure made of a flexible thin film, and the pressure receiving chamber and the equilibrium chamber are communicated through an orifice, while predetermined incompressible fluids are sealed in the pressure receiving chamber and the equilibrium chamber, respectively. be.

Effects of the Invention With this method, when high-frequency vibrations are input with small displacements, soft spring characteristics mainly due to the elastic deformation of the rubber elastic body, in other words, a low dynamic spring constant, can be obtained, and such vibrations are suppressed from the vehicle body side. It is possible to effectively block the transmission of On the other hand, when a large displacement and low frequency vibration is input, the volume of the pressure receiving chamber is reduced due to the increase in the relative displacement between the inner and outer fittings, and as a result, the incompressible fluid in the pressure receiving chamber is forced into the orifice. The incompressible fluid flows into the equilibrium chamber through the orifice, and the viscous resistance generated when the incompressible fluid flows through the orifice quickly attenuates such large displacement and low frequency vibrations. However, it has become possible to provide a composite upper support that exhibits excellent vibration isolation properties in both vibration isolation and vibration damping capabilities.

Embodiments Hereinafter, first and second embodiments of the present invention will be described in detail based on the drawings.

This embodiment is an example in which the present invention is applied to a top support in a so-called McPherson strut type suspension system for the front wheels of a vehicle.

In FIG. 1, a suspension system of the type described above is shown schematically. In this figure, 10 is a shock absorber, and a coil spring 12 is arranged around the outer periphery of this shock absorber 10. The lower end of the cylinder 14 of the shock absorber 10 is connected to a steering knuckle that rotatably supports the wheels 16, and is supported by the vehicle body 20 via an arm mechanism 18. On the other hand, the piston rod 2 of the shock absorber 10
2 is elastically connected to the vehicle body 20 via an upper support (so-called strut mount) 24.

An enlarged sectional view of this upper support 24 is shown in FIG.

As is clear from this figure, the Atsupa support 24 includes an annular outer metal fitting 26, an annular inner metal fitting 28 concentrically arranged inside the annular outer metal fitting 26,
A rubber elastic body 30 is interposed between the outer metal fitting 26 and the inner metal fitting 28, and the inner metal fitting 28 is on the inner peripheral side of the rubber elastic body 30, and the outer metal fitting 26 is on the outer peripheral side of the rubber elastic body 30. Each is fixed by known vulcanization adhesive. The outer metal fitting 26 includes a cylindrical portion 32, and the shock absorber 10 of this cylindrical portion 32
A flange portion 34 is integrally formed with the side end portion extending outward in the radial direction in an annular shape, and is attached to the vehicle body 20 by a plurality of bolts 36 erected on the flange portion 34. .
On the other hand, the inner metal fitting 28 has a cylindrical portion 38 in the center, and a circular dish-shaped member is fitted and fixed in the middle portion of the cylindrical portion 38, so that the inner metal fitting 28 extends radially outward on the shock absorber 10 side. An annular flange portion 40 is integrally formed. Further, a bearing 42 is caulked inside the cylindrical portion 38, and the shock absorber 10
The upper end of the piston rod 22 is attached to the inner fitting 28 by a nut 44 so as to be rotatable relative to the inner fitting 28.

Flange portion 34 of outer fitting 26 and inner fitting 28
In the axial direction of the piston rod 22, the outer circumferential side of the flange portion 40 is opposed to the inner circumferential side of the flange portion 34 at a predetermined distance apart, and the outer circumferential edges of the flange portions 34, 40 are Both have cylindrical edges 46 and 48 concentrically extending toward the shock absorber 10 side. The outer periphery of the rubber elastic body 30 is provided with flange portions 34, 4.
An annular recess 50 that opens toward the shock absorber 10 is formed between the two ends of the shock absorber 10 . This recess 5
0 indicates both cylindrical edges 4 of both flanges 34 and 40
6, 48, and this recess 5
0 is a relatively thin rubber elastic body 5 having an annular opening.
0, a pressure receiving chamber 58 is formed.

This rubber elastic body 52 has an L-shaped cross-sectional shape, and has an annular fixing ring 54 on the outer periphery of its upper end.
However, similarly annular fixing rings 56 are fixed concentrically to the inner periphery of the lower end by known vulcanization adhesive. The outer fixing ring 54 is press-fitted into the inner circumferential surface of the cylindrical edge 46, and the inner fixing ring 56 is press-fitted into the outer circumferential surface of the cylindrical edge 48, so that the recess 50 is fluid-tightly closed. A pressure receiving chamber 58 is formed, and the rings 54, 56 and the rubber elastic body 52 constitute a closing member.

Note that this rubber elastic body 52, together with the rubber elastic body 30, plays a role of elastically connecting the outer metal fitting 26 and the inner metal fitting 28, so that both flanges 34, 40 are relatively moved in the axial direction of the piston rod 22. The pressure receiving chamber 58 defined by the rubber elastic body 52 and the recess 50 is configured such that the outer metal fitting 26 and the inner metal fitting 28 are relative to each other in the axial direction of the piston rod 22. When approached, its volume is reduced.

On the other hand, an annular recess 60 is formed by the flange portion 40 (including the cylindrical edge portion 48) of the inner metal fitting 28 and the lower portion of the cylindrical portion 38.
This recess 60 is opened toward the shock absorber 10 on the inner peripheral side of the pressure receiving chamber 58, and the opening of this recess 60 is covered with an annular diaphragm rubber 62. Fixing rings 64 and 66 each having an annular shape are fixed concentrically to the outer and inner circumferential parts of the diaphragm rubber 62 by vulcanization adhesive, and the outer ring 64
is press-fitted into the cylindrical edge 48 of the flange portion 40, or the inner ring 66 is press-fitted into the lower portion of the cylindrical portion 38, so that the opening of the recess 60 is liquid-tightly closed and the flange portion 40 is press-fitted. An equilibrium chamber 68 is defined on the opposite side of the pressure receiving chamber 58.

Here, the rings 64, 66 and the diaphragm rubber 62 constitute a closing member, the closing member and the recess together constitute an enclosure, and the diaphragm rubber 62 constitutes a flexible thin film. It is. The diaphragm rubber 62 plays the role of allowing the volume of the equilibrium chamber 68 to increase by being elastically deformed (bulging deformation) mainly in its thickness direction, and serves to allow the volume of the equilibrium chamber 68 to increase. Since the cross-sectional dimension is longer than the interval, in other words, there is slack, the bulging deformation is facilitated.

Then, a short bushing 70 is fixed by press fitting through the cylindrical edge 48 of the flange portion 40.
The bushing hole of this bushing 70 is an orifice 72 that allows the pressure receiving chamber 58 and the equilibrium chamber 68 to communicate with each other.
is formed.

Further, the pressure receiving chamber 58 and the equilibrium chamber 68, which are defined and communicated with each other as described above, are each filled with a predetermined incompressible fluid such as water, polyalkylene glycol, or silicone oil. -ing

By the way, when manufacturing such an upper support 24, first, the outer metal fitting 26 and the inner metal fitting 28 are set concentrically in a predetermined mold, and then
A rubber material is injected between them to form a rubber elastic body 3.
0 is vulcanized and molded, and a recess 50 is formed. On the other hand, separately, a closing member is prepared in which a rubber elastic body 52 is vulcanized and molded between the rings 54 and 56. Further, another closing member is prepared by vulcanizing and molding a diaphragm rubber 62 between the rings 64 and 66.

Then, as described above, the vulcanized molded product provided with the rubber elastic body 30 between the inner metal fitting 28 and the outer metal fitting 26 is immersed in a fluid tank containing the first incompressible fluid, and is then recessed. A rubber elastic body 5 is placed in the opening at the location 50.
At the same time, the diaphragm rubber 62 is press-fitted into the opening of the recess 60.
By press-fitting the rings 64 and 66 fixed to the pressure receiving chamber 58 and the equilibrium chamber 68, the pressure receiving chamber 58 and the equilibrium chamber 68 are defined, and at the same time, the incompressible fluid is easily sealed inside them. The bearing 42 may be caulked to the inside of the cylindrical portion 38 of the inner metal fitting 28 before the ring 66 is press-fitted, prior to or after the vulcanization of the rubber elastic body 30, and the orifice 72 may be formed. Butsuyu 7
0 is preferably press-fitted into the inner metal fitting 28 as a single item.

In this way, the rubber elastic body 52 and the diaphragm rubber 62 are press-fitted into the recesses 50 and 60 through the rings, respectively, and in order to form the pressure receiving chamber 58 and the equilibrium chamber 68, the upper support 24 is formed and It has the advantage of being easy to assemble, and having the pressure receiving chamber 58 and the equilibrium chamber 68, but not having a very complicated structure.

As shown in FIG.
The piston rod 22 is attached to the inner fitting 28 in order to be elastically connected to the vehicle body 20, while the outer fitting 26 is used with the outer fitting 26 attached to the vehicle body 20.

In response to vibration input in a high frequency range with a small displacement, the elastic deformation action of the rubber elastic bodies 30 and 52 mainly in the shear direction provides a function to effectively block such vibrations. This results in a low constant and soft spring characteristics.

On the other hand, when a large displacement and low frequency vibration input acts, the relative displacement in the axial direction of the piston rod 22 between the outer metal fitting 26 and the inner metal fitting 28 becomes large, and the volume of the pressure receiving chamber 58 is reduced when the two approach each other. It will be done. Along with this, the fluid in the pressure receiving chamber 58 flows into the equilibrium chamber 68 side through the orifice 72 while causing the diaphragm rubber 62 to bulge, and when flowing through the orifice 72, a damping force against large displacement vibrations is generated. occurs. Conversely, in the process where the outer metal fitting 26 and the inner metal fitting 28 are largely displaced in the direction of separation, the volume of the pressure receiving chamber 58 increases, so that the fluid that once flowed into the equilibrium chamber 68
A similar damping force is generated when the flow flows into the pressure receiving chamber 58 side again via the orifice 72, and as a result,
It is possible to quickly suppress low-frequency vibrations with large displacements, prevent excessive deformation of the rubber elastic body 30, etc., and increase its durability, and also suppress large bounces and rebounds of unsprung members such as the wheels 16, This made it possible to improve driving stability, ride comfort, etc.

Next, another embodiment of the present invention will be described based on FIG.

The difference between the Atsupa support 74 in this embodiment and the Atsupa support 24 in the previous embodiment is that an air chamber 76 is defined on the opposite side of the equilibrium chamber 68 with the diaphragm rubber 62 in between. The point is that excessive deformation in the bulging direction can be suppressed. That is, the inner fitting 28
The opening of the annular recess 60 formed in is closed by a rigid metal enclosure 78, which stands perpendicularly to the outer and inner peripheries of the donut-shaped substrate 80, respectively. cylindrical portions 82 and 84, respectively;
4, the diaphragm rubber 62 is press-fitted into the opening of the recess 60, while the diaphragm rubber 62 is vulcanized and molded across both cylindrical parts 82, 84 of the enclosure 80 with a space between it and the substrate 80. As a result, the equilibrium chamber 68 and the air chamber 76 are defined on both sides of the diaphragm rubber 62, and air is confined in the air chamber 76.

The other parts have the same structure as the previous embodiment, so the explanation will be omitted. When the diaphragm rubber 62 is opened, the air existing in the air chamber 76 is compressed and its pressure increases, so that excessive deformation of the diaphragm rubber 62 in the expansion direction is suppressed by the pressure of the air. Therefore, the diaphragm rubber 62 can be made considerably thinner, and its durability can be increased.

In the embodiments described so far, the damping force of the upper support can be optimized by appropriately changing the diameter of the orifice 72 or increasing or decreasing the number of bushes 70 that make up the orifice 72. It is also possible to increase the damping force by increasing the length of the orifice tube such as the bush 70. For example, a long orifice pipe is arranged to extend in an arc shape along the cylindrical edge 48 of the flange portion 40, one end of which is press-fitted into the cylindrical edge 48 to open toward the pressure receiving chamber 58, and the other end It is also possible to make the orifice 72 longer by opening it toward the equilibrium chamber 68. Conversely, it is also possible to form an orifice by simply drilling a hole in the flange portion without using such an orifice tube.

Furthermore, the present invention is not limited to shock absorbers equipped with coil springs on the outside as described above, but can also be effectively applied to upper supports for strut-type suspension systems that do not have such coil springs. be able to.

In addition, although specific explanations are omitted, it goes without saying that the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit of the present invention. It's a good place.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a specific example of a suspension system including an upper support, which is an embodiment of the present invention.
FIG. 2 is an enlarged sectional view of the upper support, and FIG. 3 is an enlarged sectional view showing another embodiment of the present invention, and corresponds to FIG. 2. 10: Buffer, 20: Vehicle body, 22: Piston rod, 24, 74: Upper support, 26: Outer metal fitting, 28: Inner metal fitting, 30: Rubber elastic body, 3
2, 38: cylindrical part, 34, 40: flange part,
50, 60: recess, 52: rubber elastic body, 54, 5
6: Fixed ring, 58: Pressure receiving chamber, 62: Diaphragm rubber, 64, 66: Fixed ring, 68: Equilibrium chamber, 70: Bush, 72: Orifice, 76:
Air chamber, 78: enclosure.

Claims (1)

[Claims] 1. An outer metal fitting to be attached to the vehicle body side, an inner metal fitting to which a shock absorber piston rod is attached,
In the Atsupa support including a rubber elastic body interposed between the outer metal fitting and the inner metal fitting, a rubber elastic body is defined between the inner metal fitting and the outer metal fitting, and the relative A pressure receiving chamber whose volume is reduced by displacement is provided, and an equilibrium chamber is formed with an enclosure at least partially made of a flexible thin film on the opposite side of the pressure receiving chamber across the inner metal fitting, and the pressure receiving chamber is An atsupa support for a vehicle suspension system, characterized in that a chamber and an equilibrium chamber are communicated through an orifice, and a predetermined incompressible fluid is sealed in each of the pressure receiving chamber and the equilibrium chamber. 2. The inner metal fitting and the outer metal fitting each have a flange portion extending outward in a substantially radial direction of the shock absorber piston rod on the shock absorber side, and the pressure receiving chamber is formed between these flange portions. and the equilibrium chamber is defined on the shock absorber side across the flange portion of the inner metal fitting, and the orifice is provided passing through the flange portion of the inner metal fitting. Atsupa support described in item 1. 3. The rubber elastic body has an annular recess that opens toward the shock absorber at the end of the flange portions of both the inner metal fitting and the outer metal fitting, and the flange portions of both the inner metal fitting and the outer metal fitting have an annular recess that opens toward the shock absorber side. Claims in which the pressure receiving chamber is defined by closing the opening by press-fitting or caulking a closing member at least partially made of a rubber elastic body, which allows relative movement of the pressure-receiving chamber. Atsupa support described in Section 2. 4. An annular recess that opens toward the shock absorber is formed in the inner metal fitting, with the flange portion of the inner fitting as the main body, and a diaphragm rubber that can be elastically expanded and deformed is formed in the opening of the recess. The equilibrium chamber is defined by closing the opening by press-fitting or caulking an annular closing member containing the enclosure.
Further, the diaphragm rubber covers the flexible thin film,
Atsupa support according to claim 2 or 3, respectively. 5 On the opposite side of the equilibrium chamber across the enclosure,
The atsupa support according to any one of claims 1 to 4, wherein the air chamber for suppressing excessive deformation of the diaphragm rubber is defined by a rigid enclosure. 6. The diaphragm rubber is integrally attached to the rigid enclosure, and the enclosure is press-fitted or caulked into the opening of the recess of the inner metal fitting, so that the equilibrium is formed on both sides of the diaphragm. The atsupa support according to claim 5, wherein the chamber and the air chamber are respectively defined.