Patent ID: 9506521
Filing Date: 2016-11-29
CPC Classification: B60G,F16F

Claim Text:
1. A shock absorber system, comprising: a hydraulic shock absorber disposed between a sprung portion and an unsprung portion of a vehicle, the hydraulic shock absorber being configured to extend and contract in accordance with a relative movement of the sprung portion and the unsprung portion in an up-down direction and to generate a damping force with respect to the relative movement; a damping-force changer configured to give a resistance to a flow of a working fluid caused in the hydraulic shock absorber by the relative movement of the sprung portion and the unsprung portion and to change a magnitude of the resistance, so as to change the damping force to be generated by the hydraulic shock absorber; and a controller configured to determine a damping-force index that is an index for changing the damping force and to control the damping-force changer based on the determined damping-force index, so as to control the damping force to be generated by the hydraulic shock absorber, wherein the controller is configured to determine, as the damping-force index, a required application force that is a force to be applied to the sprung portion for damping a movement of the sprung portion in the up-down direction, according to a determination rule in which the required application force has the same direction as a direction of a sprung speed that is a speed of the sprung portion in the up-down direction when the sprung speed is relatively small and sprung acceleration that is acceleration of the sprung portion in the up-down direction is relatively large in a situation in which the direction of the sprung speed and a direction of the sprung acceleration are mutually different, and wherein in a coordinate system whose transverse axis represents the sprung speed and vertical axis represents the sprung acceleration, where there is set a boundary line which passes an origin at which both of the sprung speed and the sprung acceleration are 0 and which extends across a second quadrant and a fourth quadrant, the determination rule is visually defined as: in the determination rule the required application force has the same direction as the direction of the sprung speed when the sprung speed and the sprung acceleration belong to a region in the second quadrant that is located on one of opposite sides of the boundary line nearer to a first quadrant or a region in the fourth quadrant that is located on one of opposite sides of the boundary line nearer to a third quadrant.