US 4,877,225 AGranted

Vibration isolator

AssigneeBridgestone Corporation

InventorsTakeshi Noguchi, Kazuya Takano, Takashi Kikuchi

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Abstract

A vibration isolator mounted on a support for a vehicle engine or the like which is a vibration source, in which a central limitational passage is formed in a partition wall which divides a fluid chamber filled with a fluid into a pair of small fluid chambers, the central limitational passage providing communication between the pair of small fluid chambers. The central limitational passage can be opened or closed by a valve capable of linearly moving so that the resistance to the fluid flowing through the central limitational passage is changed when vibrations occur. Additional connectable small limitational passages are provided in the valve and partition wall to provide communication between the small fluid chambers when the central limitational passage is closed by the valve. With this structure, vibrations can be absorbed over a wide frequency range.

Claims27

Dependent claims

A vibration isolator interposed between a vibration source and a vibration receiving object and adapted to reduce and absorb vibrations transmitted from said vibration source to said object, said vibration isolator comprising:

a fluid chamber partially formed of an elastic body to expand and contract by vibrations, said fluid chamber being filled with a fluid;
a partition wall for dividing said fluid chamber into a plurality of small fluid chambers;
a relatively large central limitational passage through said partition wall capable of providing communication between said small fluid chambers;
changing means for changing the area of said central limitational passage by linearly moving itself close to or away from said central limitational passage, said changing means including a valve which abuts against said partition wall when said valve is at least substantially at the end of the stroke of its movement to at least substantially close said central limitational passage;
and
first and second relatively small limitational passages through said partition wall and said valve, respectively, said first and second limitational passages being connectable to provide communication between said small fluid chambers when said valve is at least substantially at the end of the stroke of its movement, and said changing means also adapted to control the flow of said fluid through said small limitational passages;
whereby the rate at which said fluid moves between said small fluid chambers is changed so as to enable vibrations from said vibration source to be absorbed over a wide range.

4 more elements

A vibration isolator comprising:

a vibration receiving portion supported on a vehicle body;
a supporting portion for supporting a vibration source;
an expandable fluid chamber partially formed of an elastic body and disposed between said vibration receiving portion and said supporting portion, said fluid chamber being filled with a fluid;
a partition wall for dividing said fluid chamber into a pair of small fluid chambers;
a relatively large central limitational passage formed through said partition wall and adapted to provide communication between said small fluid chambers;
a valve means including a valve passing through said central limitational passage and adapted to open and substantially close said central limitational passage by moving itself in the direction of its axis and abutting against said partition wall when said valve is at least substantially at the end of the stroke of its movement;
and
first and second relatively small limitational passages through said partition wall and said valve, respectively, said first and second limitational passages being connectable to provide communication between said small fluid chambers when said valve is at least substantially at the end of the stroke of its movement, and said valve means also adapted to control the flow of said fluid through said small limitational passages.

5 more elements

Dependencies are inferred from the claim text.