Shock absorber with bypass damping

Abstract

A shock absorber for a vehicle includes a fluid-filled cylinder having a closed end, a shaft extending partially into the cylinder, a valve attached to the first end of the shaft, and a power supply. The valve includes a valve piston and a bender. The valve piston includes at least one orifice extending therethrough. The bender is seated adjacent the orifice in the piston. The bender includes a piezoelectric material embedded therein. The piezoelectric material includes sides with conductive material disposed thereon. The power supply is attached to the conductive material across the piezoelectric material in the bender to apply a voltage across the piezoelectric material to change the stiffness of the bender. A sensor is also included for monitoring the displacement and velocity of the piston within the fluid-filled cylinder. The biasing force on the bender is changed on sensor readings according to predetermined logic sequence. In another embodiment, a dampener is provided that allows fluid bypass outside of the main fluid reservoir through a channel that leads to a valve. The valve is preferably controlled by a piezoelectric bender outside the reservoir. In various embodiments, the valve includes a balanced cylinder with secondary fluid flow controlled by the piezo bender to activate a moving diaphragm for valve movement.