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Fluid-filled cylindrical vibration damping device

Imported: 24 Feb '17 | Published: 06 Jan '04

Masaaki Hamada, Tatsuya Suzuki

USPTO - Utility Patents

Abstract

Disclosed is a fluid-filled cylindrical vibration damping device including an elastic body interposed between an inner and outer sleeves for elastically connecting these sleeves with each other. A plurality of fluid chambers filled with a non-compressible fluid are partially defined by the elastic body so that a pressure of the fluid in the plurality of fluid chambers vary upon application of a vibrational load to the vibration damping device. A first orifice passage permitting a fluid communication between the fluid chambers is at least partially defined by an elastic member adapted to be subjected to shear deformation due to a fluid pressure acting on the first orifice passage so that a cross sectional area of the first orifice passage increases according to an increase of the pressure of the fluid acting on the first orifice passage owing to the shear deformation of the elastic member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The forgoing and/or other objects features and advantages of the invention will become more apparent from the following description of a preferred embodiment with reference to the accompanying drawings in which like reference numerals designate like elements and wherein:

FIG. 1 is an elevational view in transverse cross section of a fluid-filled cylindrical vibration damping device in the form of an engine mount for use in an automotive vehicle, which is constructed according to a first embodiment of the invention;

FIG. 2 is an elevational view in axial or vertical cross section of the engine mount of FIG. 1;

FIG. 3 is a right-side elevational view of the engine mount of FIG. 1;

FIG. 4 is a cross sectional view taken along line

4

4 of FIG. 3;

FIG. 5 is a left-side elevational view of an integrally vulcanized assembly of the engine mount of FIG. 1;

FIG. 6 is a right-side elevational view of the integrally vulcanized assembly of the engine mount of FIG. 1;

FIG. 7 is a graph showing frequency characteristics of damping effects measured in the engine mount of FIG. 1, together with those measured in an engine mount constructed according to a comparative example;

FIG. 8 is an elevational view in transverse cross section of a fluid-filled cylindrical vibration damping device in the form of an engine mount for use in an automotive vehicle, which is constructed according to a second embodiment of the invention;

FIG. 9 is a cross sectional view taken along line

9

9 of FIG. 8;

FIG. 10 is a left-side elevational view of an integrally vulcanized assembly of the engine mount of FIG. 8;

FIG. 11 is a right-side elevational view of the integrally vulcanized assembly of the engine mount of FIG. 8;

FIG. 12 is a right-side elevational view corresponding to FIG. 6, showing an integrally vulcanized assembly which is incorporated within a fluid-filled cylindrical vibration damping device in the form of an engine mount for use in an automotive vehicle, which is constructed according to a third embodiment of the invention;

FIG. 13 is an elevational view in transverse cross section of a fluid-filled cylindrical vibration damping device in the form of a suspension bushing for use in an automotive vehicle, which is constructed according to a fourth embodiment of the invention;

FIG. 14 is a cross sectional view taken along line

14

14 of FIG. 13;

FIG. 15 is a left-side elevational view of an integrally vulcanized assembly of the suspension bushing of FIG. 13; and

FIG. 16 is a right-side elevational view of the integrally vulcanized assembly of the suspension bushing of FIG.

13.

Claims

1. A fluid-filled cylindrical vibration damping device comprising:

2. A fluid-filled cylindrical vibration damping device according to claim 1, wherein said elastic member comprises an elastic protruding portion, which protrudes into an interior area of said first orifice passage so as to partially narrow said first orifice passage.

3. A fluid-filled cylindrical vibration damping device according to claim 2, wherein said elastic protruding portion protrudes into said interior area of said first orifice passage with a widthwise dimension over an entire width of said first orifice passage, and includes a narrow groove formed at an intermediate portion in a widthwise direction of a protruding end portion thereof so as to extend in a longitudinal direction of said first orifice passage, said elastic protruding portion being held at a protruding end surface of said protruding end portion thereof at opposite sides of said narrow groove in said widthwise direction with an inner surface of said first orifice passage.

4. A fluid-filled cylindrical vibration damping device according to claim 3, wherein said elastic protruding portion is inclined to one of opposite sides in said longitudinal direction of said first orifice passage so that said elastic protruding portion exhibits a soft spring characteristic with respect to said fluid pressure applied thereto from an other one of opposite sides in said longitudinal direction of said first orifice passage.

5. A fluid-filled cylindrical vibration damping device according to claim 4, wherein said vibration damping device includes a plurality of said first orifice passages that are arranged in parallel to each other and are respectively provided with said elastic protruding portions inclined to respective directions different from each other.

6. A fluid-filled cylindrical vibration damping device according to claim 4, wherein said elastic body includes a groove open in an outer circumferential surface thereof, whose opening is fluid-tightly closed by said outer sleeve member to thereby form said first orifice passage, and said elastic protruding portion is integrally formed with said elastic body such that said elastic protruding portion is formed at at least one of opposite open-end portions of said first orifice passage so as to protrude radially outwardly from a bottom of said groove while being inclined toward an outward of said one of opposite open-end portions of said first orifice passage.

7. A fluid-filled cylindrical vibration damping device according to claim 4, wherein said elastic body includes a groove open in an outer circumferential surface thereof, whose opening is fluid-tightly closed by said outer sleeve member to thereby form said first orifice passage, and said elastic protruding portion is integrally formed with said elastic body such that said elastic protruding portion is formed at a longitudinally intermediate portion of said groove so as to protrude radially outwardly from a bottom of said groove while extending toward one of longitudinally opposite sides of said groove inside said groove.

8. A fluid-filled cylindrical vibration damping device according to claim 6, further comprising an intermediate sleeve member disposed radially outwardly of said inner shaft member in a spaced-apart relationship with said inner shaft member, and elastically connected with said inner shaft member via said elastic body interposed therebetween upon vulcanization of a rubber material for forming said elastic body, while said outer sleeve member is press-fitted onto said intermediate sleeve member, said groove being open in an outer circumferential surface of said intermediate sleeve member.

9. A fluid-filled cylindrical vibration damping device according to claim 8, further comprising a sealing rubber layer bonded to said outer circumferential surface of the intermediate sleeve member for ensuring a fluid-tight sealing between said intermediate sleeve member and said outer sleeve member.

10. A fluid-filled cylindrical vibration damping device according to claim 9, wherein said sealing rubber layer is utilized to form said groove open in said outer circumferential surface of said intermediate sleeve member.

11. A fluid-filled cylindrical vibration damping device according to claim 1, further comprising a second orifice passage disposed in a parallel relationship with said first orifice passage, wherein said first and second orifice passages are relatively tuned such that said first orifice passage permits resonance of fluid flowing therethrough at a first frequency range lower than a resonance frequency range of fluid flowing through said second orifice passage when said first orifice passage is in a condition where said elastic member is not subjected to shear deformation, and permits resonance of said fluid flowing therethrough at a second frequency range higher than said resonance frequency range of said fluid flowing through said second orifice passage when said first orifice passage is in a condition where said elastic member is subjected to shear deformation.

12. A fluid-filled cylindrical vibration damping device according to claim 1, wherein said plurality of fluid chambers include a pressure-receiving chamber partially defined by said elastic body whose fluid pressure varies due to an elastic deformation of said elastic body, and an equilibrium chamber partially defined by a flexible layer whose volume is variable due to an elastic deformation of said flexible layer.

13. A fluid-filled cylindrical vibration damping device according to claim 1, wherein said plurality of said fluid chambers includes a plurality of pressure-receiving chambers partially defined by said elastic body and arranged in respective circumferential portions of said elastic body so as to be opposed to each other with said inner shaft member interposed therebetween in a direction in which a vibrational load is primarily applied to said vibration damping device.