SHOCK ABSORBER WITH VARIABLE DAMPING FORCE FOR REGULATING VIBRATION-DAMPING CHARACTERISTIC AT A DESIRABLE VALUE BY PROPERLY ADJUSTING SPRING RATE OF RETURN SPRINGS

摘要

PURPOSE: A shock absorber with variable damping force is provided to secure damping characteristic active to the change of load with various ranges by changing the damping force of the shock absorber according to the degree of load transmitted from the road. CONSTITUTION: A shock absorber with variable damping force is composed of a cylinder; a piston embedded movably in the cylinder to divide upper and lower liquid chambers; a piston rod(14) combined to the piston; and a damping force variable unit disposed at the lower end of the piston rod to variably regulate the degree of damping force according to movement speed of the piston. The damping force variable unit comprises a passage forming unit passing through the piston rod and communicating the upper and lower liquid chambers in the cylinder about the piston; a movable valve body for variably adjusting communication and cutoff of the passage forming unit according to load applied from the outside; and a pre-load regulating unit for controlling the communication and cutoff of the passage forming unit according to the operation of the movable valve body at a pre-set level.