Patent ID: 6352246
Filing Date: 2002-03-05
Classification: F16F

Abstract:
A liquid filled vibration isolator comprising:an inner cylindrical metal member; a cylindrical intermediate metal member disposed on an outside of said inner cylindrical metal member at a position spaced apart from said inner cylindrical metal member, said cylindrical intermediate metal member including: a pair of ring portions formed at two ends of said cylindrical intermediate metal member in an axial direction, a connection portion for integrally connecting said pair of ring portions to each other, and an opening formed in a part of said connection portion in a direction in which main vibrations are input into said liquid filled vibration isolator; a rubber member including a pair of side wall portions for connecting said pair of ring portions of said cylindrical intermediate metal member and said inner cylindrical metal member to each other; an arm portion for connecting said pair of side wall portions in said axial direction to connect said connection portion and said inner cylindrical metal member; a recess surrounded by said pair of side wall portions and said arm portion and opened in said opening; a thin diaphragm portion disposed opposite to said opening in a radial direction such that said thin diaphragm portion is disposed so as to be spaced apart from said inner cylindrical metal member and said arm portion at a position between said pair of ring portions of said cylindrical intermediate metal member; a rubber sealing portion disposed on an outer surface of said cylindrical intermediate metal member; a passage forming member including: a circular-arc plate disposed on an outside of said connection portion and extending in a circumferential direction to close said opening, a reciprocative passage groove formed in an outer surface of said circular-arc plate to reciprocate in a circumferential direction between first and second ends of said circular-arc plate, a first communication opening which communicates with said recess at a first end of said reciprocative passage groove, and a second communication opening opened in said circumferential direction at a second end of said reciprocative passage groove; and an outer cylindrical metal member secured to an outside portion of said cylindrical intermediate metal member and said passage forming member, said outer cylindrical metal member being arranged to cause said rubber sealing portion to close a space within said cylindrical intermediate metal member in a liquid-tight manner to form a main liquid chamber in said recess and a sub-liquid-chamber defined by said thin diaphragm portion, and said outer cylindrical metal member being capable of forming an orifice passage in a space within said passage forming member to allow said main liquid chamber and said sub-liquid chamber to communicate with each other, wherein said reciprocative passage groove is formed in said orifice passage and defined by at least one partition wall extending from either of said first and second ends of said circular-arc plate, said first and second ends being located in the circumferential direction, said at least one partition wall being located inwardly from both lateral sides of said circular-arc plate in a widthwise direction such that if said at least one partition wall comprises more than one partition wall, all of said partition walls are located inwardly from said lateral sides of said circular-arc plate, and said first and second ends of said circular-arc plate in said circumferential direction having end walls extending outwardly in said radial direction.