Switchable liquid-filled vibration isolating mount

A switchable liquid-filled vibration isolating mount for isolating vibration between a first by and a second body in at least an axial direction thereof, comprising:

• a first rigid fixture for attachment to said first body;
• a second rigid fixture defining a barrel cavity and having a bottom wall spaced apart in said axial direction from said first rigid fixture, said second fixture being for attachment to said second body;
• a vibration isolating base body formed of an elastic material interposed between and connecting said first and second rigid fixtures;
• a partitioner disposed in said second rigid fixture having a first side opposing said vibration isolating body and defining a main liquid chamber therebetween and a second side opposite said first side;
• a first diaphragm disposed in said second rigid fixture opposing said second side of said partitioner and defining a sub-liquid chamber therebetween;
• a second diaphragm in said second rigid fixture between said first diaphragm and said bottom wall and defining an equilibrium chamber between said first diaphragm and said second diaphragm and defining a switching chamber between said second diaphragm and said bottom wall;
• said partitioner defining an outer orifice and an inner orifice for communicating said main liquid chamber and said sub-liquid cab with each other, said outer orifice extending a predetermined length in a circumferential direction of said partitioner, and said inner orifice being positioned radially inward of said outer orifice and being occludable by movement of said first diaphragm;
• a biasing member biasing said first diaphragm against said partitioner to occlude said inner orifice and to thereby prevent a liquid flow between said inner orifice and said sub-liquid chamber via said inner orifice;
• said switching chamber including a communication passage for selective application of an atmospheric pressure and a reduced pressure, reduced from said atmospheric pressure, to move said first diaphragm to a first position away from said partitioner against a biasing force of said biasing member to open said inner orifice such that said inner orifice communicates said main liquid chamber with said sub-liquid chamber when said reduced pressure is applied, and to move said first diaphragm to a second position to close said inner orifice such that said inner orifice does not communicate said main liquid chamber with said sub-liquid chamber when said amospheric pressure is applied;
• said inner orifice being formed as an opening in a central portion of said partitioner extending through said partitioner in said axial direction;
• said first diaphragm including a valve body coaxial with said inner orifice for closing said inner orifice, said valve body having a projection fitting in said inner orifice, wherein switching between said reduced pressure and said atmospheric pressure for said switching chamber moves said valve body to occlude or open said inner orifice;
• and
• said valve body having lateral deviation-preventing structure on an outer circumference of said projection, said lateral deviation-preventing structure including a plurality of parts provided at intervals in a circumferential direction of said projection and being engageable with a periphery of said inner orifice.