Liquid-sealing type variation isolating apparatus

A liquid-sealing type vibration isolating apparatus comprising:

• a coupler attached to a vibrating body;
• a holder attached to a vehicle body side;
• an insulator provided between said coupler and said holder that absorbs and isolates vibration from said vibrating body;
• a vibration isolating mechanism which directly follows said insulator and is formed with a liquid chamber containing a liquid in the form of an incompressible fluid wherein said vibration isolating mechanism includes a main chamber having a wall formed by a part of the insulator and seals the liquid, wherein said main chamber is arranged in series with said insulator;
• an auxiliary chamber connected to said main chamber via a first orifice, wherein said liquid flows through said first orifice, wherein said auxiliary chamber is separated from said main chamber by a first partition plate formed of a rigid body;
• an equilibrium chamber divided from said main chamber via a first diaphragm which allows the volume in the equilibrium chamber to change, wherein said equilibrium chamber is formed between said main chamber and said first partition plate;
• an air chamber divided from said auxiliary chamber via a second diaphragm and which constantly receives air, wherein said second diaphragm has a shape having a stopper-like projection which is in constant contact with the first partition plate forming the lower surface of said equilibrium chamber, and said second diaphragm has a higher deformation rigidity than said first diaphragm;
• a switching mechanism which continuously introduces one of a negative pressure and atmospheric pressure into said equilibrium chamber in synchronization with engine vibration;
• a control mechanism which controls the switching operation of said switching mechanism;
• a third liquid chamber connected to said main chamber via a second orifice and formed between said main chamber and said first partition plate to receive the liquid in said main chamber;
• and
• a second partition plate serving as a stopper, provided in said main chamber above said equilibrium chamber wherein the second orifice is provided in a portion of said second partition plate.