Patent ID: 6860370
Filing Date: 2005-03-01
Classification: F16F

Abstract:
1. A controllable damping force hydraulic shock absorber comprising: a cylinder in which a hydraulic fluid is sealably contained; a piston slidably fitted in the cylinder; a piston rod having one end connected to the piston and the other end extended to the outside of the cylinder; an extension-stroke passage which allows flow of the hydraulic fluid during an extension stroke of the piston rod; a compression-stroke passage which allows flow of the hydraulic fluid during a compression stroke of the piston rod; and a pilot type damping force control valve provided in at least one of the extension-stroke passage and the compression-stroke passage, wherein a check valve is provided at an inlet of a pilot chamber of the pilot type damping force control valve so as to allow flow of the hydraulic fluid into the pilot chamber and prevent flow of the hydraulic fluid out of the pilot chamber.