Active hydraulic fluid vehicular suspension damper

Abstract

A vehicular damper includes a cylinder, a piston rod in the cylinder having a hollow end defining an axial rod passage and a cylindrical piston affixed to the end of the rod dividing the cylinder into a compression chamber and a rebound chamber. A valve plate on the rod adjacent the piston has a plurality of soft channels extending from an outer end at the rebound chamber to an inner end at the axial rod passage and a solenoid actuated cylinder in the rod passage is movable to open and close the inner ends of the soft channels. A bi-directional working disc contacts with the soft channels' outer ends to provide damping in rebound and compression when the solenoid valve is open. In contrast, the piston has a plurality of firm rebound channels and a like plurality of firm compression channels extending therethrough with a uni-directional rebound working disc in valve contact with the outlet of the rebound chambers and a uni-directional compression working disc in valve contact with the outlet of the compression chambers. The damper provides valved parallel flow between compression and rebound chambers through the soft channels and through the firm channels with independent spring rate control through the firm rebound and compression channels.