Patent ID: 7757826

Claim:
A damping force adjustable fluid pressure shock absorber, comprising: a cylinder in which a fluid is sealingly contained; a piston slidably fitted in the cylinder so as to divide an inside of the cylinder into two chambers; a piston rod having one end coupled to the piston and an opposite end extending to an outside of the cylinder; an extension-side passage and a compression-side passage through which the two chambers in the cylinder are in communication with each other; a pilot type damping valve provided at one of the extension-side passage and the compression-side passage, and a damping valve provided at the other of the extension-side passage and the compression-side passage; a first check valve provided on a downstream side of the pilot type damping valve and provided at the one of the passages so as to be arranged in series with the pilot type damping valve; and a second check valve provided on a downstream side of the damping valve and provided at the other of the passages so as to be arranged in series with the damping valve, wherein a damping force is generated by controlling a fluid flow caused by a sliding movement of the piston in the cylinder by means of the pilot type damping valve and the damping valve, and the damping force can be adjusted by controlling a valve-opening pressure of the pilot type damping valve by means of a pilot pressure as which a part of the fluid flow is utilized, and by controlling the pilot pressure by means of a damping force adjusting valve; and an intermediate chamber through which a first section between the pilot type damping valve and the first check valve is in communication with a second section between the damping valve and the second check valve, a downstream side of the damping force adjusting valve being connected to the intermediate chamber.