Abstract: A liquid chamber is arranged with a first support member (1), a second support member (2) and an elastic member (3), an inside of the liquid chamber is divided to a main liquid chamber (11) and an auxiliary liquid chamber (12) by a partition member (10) and both chambers are communicated with an orifice passage (14). On an inner face of a conical portion (4) of the elastic member (3), thin wall portions (7) are provided by forming recess portions (6) at axis symmetrical positions so as to yield a minimum value for a dynamic spring characteristic against a vibration input in a designated medium frequency by a membrane resonance and a medium to high frequency device (17) projecting into the main liquid chamber (11) is provided to the first support member (1) so as to yield a minimum value for the dynamic spring characteristic against a vibration input in a designated high frequency.

Abstract: An orifice plate is projectingly provided within a fluid chamber formed inside an elastic block to damp the medium to high frequency vibrations. The orifice plate is arranged to have a projection area which is maximum in the principal input direction Z of vibrations to be isolated, medium in the direction Y of the two input directions X and Y which are perpendicular to the direction Z, and minimum in the direction X by providing a recess at a bottom thereof which traverses in the same direction (as the direction X). The resonance frequency is high in the direction Y and the circumferential edge portions of the projection surface in the direction Y are adapted to serve as stoppers which perform the displacement control in the direction X. In another embodiment, the stoppers are asymmetrically shaped.

Abstract: An orifice plate 20 is projectingly provided within a fluid chamber formed inside an elastic block to damp the medium to high frequency vibrations. The orifice plate 20 is arranged to have a projection area which is maximum in the principal input direction Z of vibrations to be isolated, medium in the direction Y of the two input directions X and Y which are perpendicular to the direction Z, and minimum in the direction X by providing a recess 26 at a bottom thereof which traverses in the same direction (as the direction X), whereby the resonance frequency is high in the direction Y and the circumferential edge portions of the projection surface in the direction Y are adapted to serve as stoppers 25 which perform the displacement control in the direction X.

Abstract: A long damping orifice 60 having a circular shape as viewed from above and a short linear idle orifice 61 are disposed and the orifices are connected by a common inlet 32, whereas an outlet side is formed separately into a first outlet 52 and a second outlet 53, which is opened and closed by a valve portion 21 which is in a unit with a diaphragm 7. Though the valve portion 21 is open by the negative suction-air pressure of an engine during idling, at this time, since the center of the second outlet 53 is shifted from the center of the valve body 21 toward a flowing direction of fluid flowing through the idle orifice 61, the valve portion 21 is open obliquely to prevent the turbulent flow of fluid in the vicinity of the second outlet 53, switching fluid-sealed mount characteristics rapidly.

Abstract: A fluid-chamber space 21 of an elastic block 20 interposed between an outer cylinder 10 and an inner cylinder 30 is partitioned into two chambers by means of an elastic wall 40, whose inner edges 44 are engaged to an engaging groove of an elastic wall mount 24, and outer edges 46 are clamped between end portions of two fluid-chamber covers 50 covering an open portion of the fluid-chamber space 21. When pressed into the outer cylinder 10 in this state, even when the elastic wall 40 deforms elastically by fluid pressure, since a contact portion with the elastic block 20 around the elastic wall 40 is moveable, the internal pressure rise is suppressed and the concentration of stress is relieved, thus low-action spring and high attenuation characteristics are obtained and durability is improved.

Abstract: A first connecting member 1 secured to an engine, a second connecting member connected to an automobile vehicle and a rubber block 3 of a cylindrical shape for connecting the first and second connecting members are provided. The rubber block 3 is divided by a partition wall 6 into a first chamber 8 and a second chamber 9 and an orifice passage 34 is disposed to communicate with both chambers. The orifice passage 34 and the first chamber 8 are adapted to communicate with each other by an intermediate opening portion 37 which is opened and closed by a passage length adjustable valve 38 and passage end opening portions which are always open. The rubber block 3 has a cylindrical portion 5, the wall of which serves at a part thereof as a movable wall portion 12.

Abstract: A vibration isolator includes a substantially sealed space within a housing 4 forming a liquid chamber by partitioning the sealed space with a diaphragm 5. The liquid chamber is further partitioned into first and second chambers 7 and 8 by a rubber partition wall 6. An orifice passage 9 is arranged to communicate between these two chambers 7 and 8. The rubber partition wall 6 is provided at its intermediate portion with a membrane portion 11, a part of which is adapted to serve as a stopper portion 12. When the membrane portion 11 is bent and deformed downwardly, the stopper portion 12 is pushed, at its front end, on a partition wall supporting member 14 for deformation. The repulsion force of the stopper portion 12 by the deformation varies non-linearly in response to the deformation of the membrane portion 11 and as a result, the spring characteristic of the membrane portion 11 also becomes non-linear.