| 摘要 |
PROBLEM TO BE SOLVED: To vary a spring constant nonlinearly by varying the membrane stiffness of a movable membrane exposed to a main liquid chamber to absorb a rise in the internal pressure of the main liquid chamber. SOLUTION: A cylindrical part 7 of an elastic body member 5 defining a main liquid chamber 20 is partly formed as a movable membrane 10, whose exterior is covered in a holder 11 with the interior as a control chamber 13 and switchable between an atmosphere opening state and a vacuum state. The control chamber 13 houses a movable membrane stopper 15 comprising an elastic member, and a contact surface 40 thereof has projectingly formed projections 41, discontinuous portions 42 circumferentially along the projections 41 and a stopper hole 43 passing the center of the movable membrane stopper 15. The movable membrane 10, under a rise in internal pressure, elastically deforms the projections 41 and next elastically deforms the movable membrane stopper 15, so that the membrane stiffness is varied according to the internal pressure rise to thus vary the spring constant non-linearly. |
