Spring devices – Resilient shock or vibration absorber – Including energy absorbing means or feature
Reexamination Certificate
2002-07-11
2004-03-23
Siconolfi, Robert A. (Department: 3683)
Spring devices
Resilient shock or vibration absorber
Including energy absorbing means or feature
C267S140150
Reexamination Certificate
active
06708963
ABSTRACT:
INCORPORATED BY REFERENCE
The disclosure of Japanese Patent Application No. 2001-215662 filed on Jul. 16, 2001 and No. 2001-320692 filed on Oct. 18, 2001, each including the specification, drawings and abstract is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to fluid-filled vibration-damping devices exhibiting vibration-damping effect on the basis of flows of non-compressible fluid filled therein, and a method of controlling these devices. More particularly, the present invention is concerned with such a fluid-filled vibration-damping device that is suitably applicable to an engine mount, a body mount or the like for use in an automotive vehicle, and a method of controlling the same.
2. Description of the Related Art
A fluid-filled vibration-damping device is known as one type of a vibration-damping device interposed between two members of a vibration system for elastically connecting the two members, or for mounting one of the two members of the vibration system on the other member in a vibration-damping fashion. The known fluid-filled vibration-damping device includes: a first mounting member adapted to be attached to one of the two members of the vibration system; a second mounting member adapted to be attached to the other member of the vibration system; a rubber elastic body elastically connecting the first and second mounting members; a pressure-receiving chamber partially defined by the rubber elastic body and filled with a non-compressible fluid; an equilibrium chamber partially defined by a flexible layer and filled with the non-compressible fluid; and an orifice passage permitting a fluid communication between the pressure-receiving chamber and the equilibrium chamber. The known fluid-filled vibration-damping device is capable of exhibiting a desired vibration-damping effect on the basis of flows of the fluid through the orifice passage, and is favorably used as an engine mount or other damping members for use in an automotive vehicle.
Generally, a fluid-filled vibration-damping device when used as a vehicle engine mount is required to exhibit different damping characteristics depending on the type of the input vibrations having different frequencies and amplitudes. However, the range of frequency of the input vibrations that can be effectively damped by fluid flows through an orifice passage is relatively narrow. Therefore, a fluid-filled vibration-damping device using a single orifice passage is generally incapable of exhibiting desired damping characteristics to a satisfactory extent.
In view of the above problem, there has been proposed a mount structure comprising a plurality of orifice passages each permitting a fluid communication between the pressure-receiving chamber and the equilibrium chamber, and being tuned to a plurality of frequency ranges to be damped or isolated, respectively. Based on the resonance of the fluid flowing through the plurality of orifice passages, this mount structure can exhibit a vibration-damping effect with respect to the input vibrations over a wide or a plurality of different frequency bands to which the plurality of orifice passages are respectively tuned.
However, in the mount structure constructed as described above, a resistance to flow of the fluid through the orifice passage tuned to a low frequency range is made higher than that of the orifice passage tuned to a high frequency range. Accordingly, the fluid is prone to flow through the orifice passage tuned to the high frequency range, rather than the orifice passage tuned to the low frequency range, resulting in insufficient damping effect based on the flows of the fluid through the orifice passage tuned to the low frequency range.
JP-A-8-270718 discloses an example of another type of the fluid-filled vibration-damping device, which has been proposed to cope with the above-described problem. The disclosed damping device includes an orifice closing member adapted to bring the orifice passage tuned to the high frequency range into an operable state or an inoperable state, thus being capable of selectively effecting the orifice passage tuned to the low frequency range and the orifice passage tuned to the high frequency range.
In the case where the fluid-filled vibration-damping device uses three or more orifice passage, two or more orifice closing members need to be disposed within the device, leading to a complicated structure and a sophisticated manner of control of the operation of the device. Thus, the conventional fluid-filled vibration-damping device suffers from difficulty in exhibiting excellent damping effect with respect to input vibrations over three or more different frequencies.
If all of the plurality of orifice passages tuned to different frequency ranges are held in their operable states simultaneously, then the orifice passage, which is tuned to the lowermost frequency range, and accordingly has a high resistance to flow of the fluid therethrough, inevitably suffers from lack of an amount of flow of the fluid therethrough. For the above reasons, it is significantly difficult to achieve different damping effect with respect to input vibrations having different frequencies, simultaneously, even in the fluid-filled vibration-damping device equipped with the plurality of orifice passages and the orifice closing members.
SUMMARY OF THE INVENTION
It is therefore one object of this invention to provide a fluid-filled vibration-damping device that is novel and simple in construction and that is capable of exhibiting an excellent vibration-damping effect input vibrations over a plurality of frequencies or a wide range of frequency of the input vibrations.
It is another object of the invention to provide a method of controlling operation of the fluid-filled vibration-damping device of the invention.
The above and/or optional objects of this invention may be attained according to at least one of the following modes of the invention. Each of these modes of the invention is numbered like the appended claims and depending from the other mode or modes, where appropriate, to indicate possible combinations of elements or technical features of the invention. It is to be understood that the principle of the invention is not limited to these modes of the invention and combinations of the technical features, but may otherwise be recognized based on the teachings of the present invention disclosed in the entire specification and drawings or that may be recognized by those skilled in the art in the light of the present disclosure in its entirety.
(1) A fluid-filled vibration-damping device for connecting two members in a vibration-damping fashion, that includes: (a) a first mounting member and a second mounting member disposed in a mutually spaced-apart relationship with each other and adapted to be attached to the two members, respectively; (b) an elastic body elastically connecting the first and second mounting members, and partially defining (c) a pressure-receiving chamber filled with a non-compressible fluid whose pressure varies upon application of a vibrational load to the pressure-receiving chamber; (d) a flexible diaphragm partially defining an equilibrium chamber filled with the non-compressible fluid and whose volume is variable; (e) a first orifice passage for fluid communication between the pressure-receiving chamber and the equilibrium chamber; (f) a second orifice passage for fluid communication between the pressure-receiving chamber and the equilibrium chamber, the second orifice passage being tuned to a frequency range that is higher than a frequency range to which the first orifice passage is tuned; (g) a shut-off valve mechanism operable to selectively bring the second orifice passage to an operable state and an inoperable state, while permitting a fluid communication through the first orifice passage; (h) an elastic oscillation plate partially defining the pressure-receiving chamber so that a fluid pressure in the pressure-receiving chamber acts on one of opposite
Kato Kazuhiko
Matsuoka Hideki
Nishi Naoki
Beyer Weaver & Thomas LLP
Siconolfi Robert A.
Tokai Rubber Industries Ltd.
LandOfFree
Fluid-filled vibration-damping device and method of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fluid-filled vibration-damping device and method of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluid-filled vibration-damping device and method of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3252468