Patent ID: 8366190

Claim:
A damper comprising: a vessel; a partitioning member which partitions an interior of said vessel into first and second accommodation chambers for accommodating a viscous fluid in an axial direction of said vessel, and which rotates together with said vessel in a direction about an axis of said vessel and is movable with respect to said vessel in the axial direction of said vessel, said partitioning member having at least one communicating hole formed therein so as to allow the first and second accommodating chambers inside said vessel to communicate with each other; moving force imparting means for imparting to said partitioning member a moving force in one direction in the axial direction by the input of relative rotation in one direction in the direction about the axis of said vessel with respect to said vessel, so that a moving velocity of the partitioning member in the one direction in the axial direction is set to one corresponding to a rotating velocity of that input of rotation; resilient means for resiliently urging said partitioning member in another direction in the axial direction with respect to said vessel; and flow limiting means for limiting the flow of the viscous fluid in the first accommodating chamber on the one direction side in the axial direction into the second accommodating chamber on the another direction side in the axial direction through the communicating hole when the internal pressure of the viscous fluid accommodated in the first accommodating chamber has exceeded a fixed value owing to the movement of said partitioning member in the one direction in the axial direction, wherein said first accommodating chamber is defined by a first end face of said partitioning member on the one direction side in the axial direction, wherein said second accommodating chamber is defined by a second end face of said partitioning member on the another direction side in the axial direction, wherein said flow limiting means includes a variable passage forming member having a plate portion which is disposed within said first accommodating chamber, has a third end face on the one direction side in the axial direction, a fourth end face on the another direction side in the axial direction, is fitted to said partitioning member movably in the axial direction in such a manner as to oppose at said fourth end face said first end face so as to form a cross-section variable passage communicating with the communicating hole.