DAMPING-FORCE-ADJUSTABLE HYDRAULIC SHOCK ABSORBER

摘要

PROBLEM TO BE SOLVED: To miniaturize a pilot-operated damping force adjusting mechanism having expansion/contraction-reversed characteristics. SOLUTION: A pilot-operated main damping valve M common to expansion and compression and having an expansion pressure receiving surface 20 and a compression pressure receiving surface 22 is disposed in a piston member 3 having a piston part 4 slidably fitted in a cylinder 2 filled with oil liquid. A pilot control valve P controls a pressure in a pilot chamber 19 to adjust a valve opening pressure of the main damping valve M. The use of the main damping valve M and pilot control valve P shared between expansion and compression can realize miniaturization. A reversal of an expansion/contraction stroke of a piston rod can reverse a high/low phase of pressure in the pilot chamber 19 controlled by the pilot control valve P to produce damping force of expansion/contraction-reversed characteristics. COPYRIGHT: (C)2003,JPO