Spring devices – Resilient shock or vibration absorber – Including energy absorbing means or feature
Reexamination Certificate
1999-09-02
2001-09-25
Oberleitner, Robert J. (Department: 3613)
Spring devices
Resilient shock or vibration absorber
Including energy absorbing means or feature
Reexamination Certificate
active
06293531
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vibration damping mount for installation between a sub-frame of a vehicle suspension device and a vehicle body.
2. Description of Related Art
It is well known that a vibration-damping sub-frame structure having a vibration-damping mount disposed between a sub-frame of a vehicle suspension device and a vehicle body is effective for reducing vehicle vibration and noise. The vibration-damping mount generally includes an inner cylindrical sleeve and outer cylindrical sleeve which are coaxially arranged with each other. A vibration-damping rubber body is disposed between the inner cylindrical sleeve and outer cylindrical sleeve, and is joined thereto. The vibration-damping mount thus-arranged is installed in the vehicle by securing the inner cylindrical sleeve to the vehicle body with bolts, and fitting the outer cylindrical sleeve into an opening provided in the sub-frame. One axial end of the outer cylindrical sleeve normally bends radially outwardly to define a flange. An annular rubber stopper is formed on the flange such that an end edge of the annular rubber stopper abuts a stopper plate which is secured to one axial end of the inner cylindrical sleeve.
The above-described conventional vibration-damping sub-frame structure reduces vehicle vibration and noise, but degrades stability and controllability. This disadvantage is caused by a relative displacement occurring in the vibration-damping mount between the outer cylindrical sleeve secured to the sub-frame and inner cylindrical sleeve secured to the vehicle body. This displacement is due to a force exerted from the suspension to the sub-frame. In particular, the relative displacement occurring in the vertical direction of the vehicle affects the vehicle stability and controllability.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a vibration-damping mount capable of reducing vehicle vibration and noise, and improving vehicle stability and controllability.
A first aspect of the vibration-damping mount in accordance with the present invention includes an inner cylindrical sleeve and outer cylindrical sleeve coaxially arranged with each other, and a vibration-damping rubber body disposed between the inner cylindrical sleeve and outer cylindrical sleeve, and is joined thereto.
One axial end of the outer cylindrical sleeve projects radially outwardly to define an annular flange. An annular rubber stopper is formed on the annular flange so as to abut a stopper plate which is secured to the inner cylindrical sleeve. One axial end of the vibration-damping rubber body extends along the annular flange to define a thick-walled end which acts as the annular rubber stopper. A rubber spacer is disposed in an annular space defined by the rubber stopper, the vibration-damping rubber body and the stopper plate. In a preferred embodiment, the rubber spacer is disposed so as to abut both a bent portion of the outer cylindrical sleeve, and a facing surface of the stopper plate, so as to be compressed and generate a reaction force to the obliquely applied force caused by the relative displacement between the inner cylindrical sleeve and outer cylindrical sleeve.
The vibration-damping mount thus-arranged exhibits spring characteristics which reflect low spring constants in the frequency region corresponding to the micro displacement such as vibration and noise, and high spring constants in the frequency region corresponding to the large load generated by the operation of a steering wheel, for example.
With respect to the spring constant, the rubber spacer behaves as follows.
When a small amount of displacement occurs, offset and slippage in both a rubber-to-rubber interface between the rubber spacer and vibration-damping rubber body, and a rubber-to-metal interface between the rubber spacer and stopper plate occurs, thereby decreasing the effective spring constant. This causes the vibration-transmissibility to decrease, and consequently prevents vibration and noise.
When large loads are applied to the vehicle, such as when operating the steering wheel to make a turn, for example, an inside wheel tends to lift due to the roll movements of the vehicle. At this time, the rubber spacer is compressed and generates a reaction force, thereby increasing the spring constant. This results in the stopper plate and inner cylindrical sleeve being pressed in a downward direction to generate a force adapted to restrain the lifting of the vehicle body, thereby obtaining good vehicle stability and controllability.
With a second aspect of the vibration-damping mount in accordance with the present invention, the rubber spacer is provided separately from the vibration-damping rubber body. With this arrangement, the rubber spacer and vibration-damping rubber body can be composed of different rubber materials having different properties. Consequently, the rubber hardness of these members can be determined separately from each other; thereby facilitating the adjustment of the spring properties thereof.
In accordance with a third aspect of the vibration-damping mount of the present invention, the rubber spacer is formed integrally with the vibration-damping rubber body. For example, the rubber spacer is obtained by extending the vibration damping rubber body so as to be positioned in the space between the rubber stopper and stopper plate. With this arrangement, a rubber-to-rubber interface and/or rubber-to-metal interface can be provided, and consequently, a high spring constant can be obtained against the large oblique loads applied to the vehicle, thereby effecting operational advantages similar to those of the first aspect of the present invention.
Other objects, features, and characteristics of the present invention will become apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification.
REFERENCES:
patent: 4392640 (1983-07-01), Kakimoto
patent: 4401198 (1983-08-01), Kunczynski
patent: 4811933 (1989-03-01), Inagaki et al.
patent: 5026031 (1991-06-01), Court
patent: 5181698 (1993-01-01), Fiene et al.
patent: 5190269 (1993-03-01), Ikeda et al.
patent: 5503376 (1996-04-01), Simuttis et al.
patent: 5551675 (1996-09-01), Simuttis et al.
patent: 5667205 (1997-09-01), Mutoh et al.
patent: 5690320 (1997-11-01), Kanda
patent: 6029961 (2000-02-01), Meyerink et al.
Furuie Tuneichi
Gotou Masanao
Kato Hisayoshi
Suzuki Tatsuo
Takeo Shigeki
Kramer Devon
Oberleitner Robert J.
Pillsbury & Winthrop LLP
Toyoda Gosei Co,., Ltd.
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