Pneumatically operated active vibration damping device and vibration damping apparatus using the same

A pneumatically operated fluid-filled active vibration-damping apparatus comprising:

• a pneumatically operated fluid-filled active vibration-damping device including:
• an elastic body elastically deformed due to vibrational loads applied the to;
• a primary fluid chamber partially defined by said elastic body and filled with a non-compressible fluid;
• a movable member being elastically displaceable and partially defining said primary fluid chamber on one of opposite sides thereof a working air chamber disposed an other one of opposite sides of said movable member, which is remote from said primary fluid chamber;
• and an air reservoir directly extending from said working air chamber and fluid-tightly close at its protruding end portion;
• an external air piping system independent of said vibration-damping device and connected to said working air chamber of said vibration-damping device in order to apply an air pressure variation to said working air chamber from an external area;
• a switch valve disposed on said air piping system and operable for alternately connecting said working air chamber to two air pressure sources having different pressure values for generating said air pressure variation in said working air chamber, wherein a wall of said working air chamber is formed with a first outlet adapted to be connected with a closed tubular pipe for forming said air reservoir, and a second outlet adapted to be connected with said external air piping system for applying said air pressure variation to said working air chamber.