A vibration-damping device (10) of the present invention includes a first attachment member (11), a second attachment member (12), an elastic body (13), and a partition member (16). In the partition member, a restriction passage (24) through which the first liquid chamber (14) and the second liquid chamber (15) communicate with each other is formed. The restriction passage includes a first communicating portion (26) which opens to the first liquid chamber, a second communicating portion (27) which opens to the second liquid chamber, and a main body flow passage (25) through which the first communicating portion and the second communicating portion communicate with each other. At least one of the first communicating portion and the second communicating portion includes a plurality of fine holes (26a) which are disposed in a flow passage direction of the main body flow passage. In plurality of fine holes, a flow passage length of a fine hole located apart from the other of the first communicating portion and the second communicating portion in the flow passage direction becomes longer.

Provided is a liquid-filled vibration isolator through which durability of an elastic movable body can be improved. In a case that a liquid pressure of liquid passing through a second orifice P2 is exerted to an outer circumference portion 12 of an elastic movable body 10, whole of the outer circumference portion 12 deforms so as to bend. Based on deformation of the outer circumference portion 12, a first valve portion 13 and facing surfaces 81c, 91c mutually contact or separate. Thereby, the communication state and the blocking state of the second orifice P2 are switched. Since it can be restrained that stress is concentrated in a part of the outer circumference portion 12 by wholly bending the outer circumference portion 12, cracks are less likely to occur in the outer circumference portion 12.

A fluid-filled vibration-damping device including: a first mounting member; a second mounting member; a main rubber elastic body elastically connecting the two mounting members; a fluid chamber whose wall is constituted by the main rubber elastic body at a portion and by a flexible film at another portion, the fluid chamber being filled with a non-compressible fluid; a fixation member being attached to an outer peripheral rim of the flexible film and being disposed inside or outside the tubular second mounting member such that the fixation member is superposed to the second mounting member in an axis-perpendicular direction; an insertion hole formed in the second mounting member and the fixation member; and a positioning member inserted through the insertion hole so as to relatively position the second mounting member and the fixation member at a scaling position by axial locking.

An engine mount includes a nozzle plate mounted between an insulator and a diaphragm so as to divide an interior into an upper liquid chamber and a lower liquid chamber, and an annular flow path formed in the nozzle plate so that an encapsulated hydraulic liquid flows between the upper liquid chamber and the lower liquid chamber, the nozzle plate being opened at an upper side of the flow path; a shielding member which has two or more shielding plates arranged to cover the upper side of the flow path; an adjusting bolt which is rotatably mounted in a core coupled to the insulator; and a connector, in which the shielding plates are folded or unfolded in accordance with a rotation of the adjusting bolt, and a size of an upper flow path hole is determined depending on a state in which the shielding plates are folded or unfolded.

The invention is a liquid filled type vibration isolating device (10) which includes a partition member (16) that partitions a liquid chamber (19) within a first attachment member (11) filled with a liquid into a first liquid chamber (14) and a second liquid chamber (15), and in which a restricted passage (24), which is configured to allow the first liquid chamber and the second liquid chamber to communicate with each other, is formed in the partition member. The restricted passage includes a first communication part (26) opening to the first liquid chamber, a second communication part opening to the second liquid chamber, and a main flow passage (25) that allows the first communication part and the second communication part to communicate with each other. At least one of the first communication part and the second communication part includes a plurality of pores (26a) that penetrate a first barrier (38) facing the first liquid chamber or the second liquid chamber. At least one pore of the plurality of pores has a flow passage length of the pore that is 3 times or more the minimum value of the internal diameter of the pore.

A vibration isolator (10) is a liquid-enclosed vibration isolator and includes: a tubular first mounting member (11) connected to one of a vibration generator and a vibration absorber, and a second mounting member (12) connected to the other; an elastic body (13) elastically connecting the mounting members; and a partition member (16) partitioning a liquid chamber (19) in the first mounting member (11) within which a liquid (L) is enclosed into a primary liquid chamber (14) that uses the elastic body (13) as a part of a wall surface thereof and a secondary liquid chamber (15), wherein the partition member (16) is formed with a restriction passage (24) communicating the primary and secondary liquid chambers (14, 15) with each other, and a porous body (28) having numerous pores (31), which are disposed in parallel so as to communicate a side of the primary liquid chamber (14) and a side of the secondary liquid chamber (15) with each other, is arranged in the restriction passage (24).

A partition member (16) is provided with a whirl chamber unit (31a, 31b) that causes two liquid chambers to communicate with each other, the whirl chamber unit (31a, 31b) includes a whirl chamber (33a, 33b) that whirls a liquid flowing therein, a rectification passage (34a, 34b) that causes one liquid chamber to communicate with the whirl chamber (33a, 33b) and that is opened in the whirl chamber (33a, 33b) in a circumferential direction of the whirl chamber (33a, 33b), and a communication hole (32a, 32b) that causes the other liquid chamber to communicate with the whirl chamber (33a, 33b). The whirl chamber (33a, 33b) forms a whirl flow of a liquid depending on a flow rate of the liquid flowing from the rectification passage (34a, 34b) and causes the liquid to flow from the communication hole (32a, 32b). The whirl chamber unit (31a, 31b) includes a plurality of first whirl chamber units (31a) in which a first whirl chamber (33a) as the whirl chamber communicates with the first liquid chamber (14) via a first rectification passage (34a) as the rectification passage and communicates with the second liquid chamber (15) via a first communication hole (32a) as the communication hole. The vibration prevention device (10) can exhibit damping characteristics with high accuracy.

A vibration damping device includes a first cylindrical attachment member (11) which is connected to one of a vibration generating portion and a vibration receiving portion, a second attachment member (12) which is connected to the other thereof, an elastic body (13) which connects both attachment members (11 and 12), and a partition member (17) which divides a liquid chamber (14), in which a liquid (L) is sealed and which is positioned within the first attachment member (11), into a primary liquid chamber (15) having the elastic body (13) as a portion of a wall surface, and into a secondary liquid chamber (16). Limiting passages (21 and 22) which communicate with the primary liquid chamber (15) and the secondary liquid chamber (16) are formed in the partition member (17). The limiting passages (21 and 22) include the first limiting passage (21) which generates resonance with respect to input of idle vibration, and the second limiting passage (22) which generates resonance with respect to input of shake vibration. Flow regulation chambers (23 and 24) which communicate with the primary liquid chamber (15) or the secondary liquid chamber (16) and the first limiting passage (21) are provided in the partition member (17). The flow regulation chambers (23 and 24) convert the flow of the liquid (L), which flows into the flow regulation chambers (23 and 24) during the input of shake vibration, into a swirl flow.

A bush-type transmission mount, in which an orifice, operating as a fluid passage that connects a first fluid chamber and a second fluid chamber to each other, is directly formed to a desired length in a core that is coupled to a main rubber to improve vibration-damping characteristics. A membrane is fitted into an outlet portion of the orifice, which communicates with the first fluid chamber, in a sliding manner, thereby improving low-frequency idle vibration and high-frequency dynamic characteristics.

A partition member of an anti-vibration hydraulic mount includes a first channel and a second channel between the working chamber and the compensating chamber. The partition member includes a membrane secured in a receiving cavity. The membrane divides the receiving cavity into two sub-spaces separated fluidically from each other. The membrane comprises a closing device configured to have an open configuration, in which the closing device is spaced apart from the central opening, and a closed configuration, in which the closing device abuts against the central opening to close the central passageway.