Patent ID: 9249854
Filing Date: 2016-02-02
CPC Classification: F16F

Claim Text:
1. A piston valve assembly for a shock absorber, comprising: a piston rod reciprocating within a cylinder; a main piston mounted on the piston rod to partition the cylinder into upper and lower chambers, wherein a plurality of compression passages and a plurality of rebound passages pass through the main piston in a vertical direction; a pressure valve mounted on the piston rod and disposed below the main piston, wherein a first pressure chamber having a ring shape around the piston rod is formed in a bottom surface of the pressure valve and an inlet hole is formed in an upper portion of the first pressure chamber; a disk installed on the inlet hole so as to prevent a continuous increase in a pressure of the first pressure chamber; a lower retainer mounted on the piston rod and disposed below the pressure valve, wherein a top surface of the lower retainer is opened; a plurality of bypass passages formed on an outer periphery of the piston rod from an upper side of the main piston to an upper side of the lower retainer along a vertical length direction; a guide assembly mounted on the piston rod and disposed between the pressure valve and the lower retainer to surround an outer periphery of the pressure valve and a bottom surface of the pressure valve, wherein the guide assembly tightly contacts the bottom surface of the pressure valve in a high-frequency mode and moves down toward the lower retainer in a low-frequency mode; and a lower disk assembly mounted on the piston rod and disposed between the guide assembly and the lower retainer, wherein the lower disk assembly forms a second pressure chamber in the lower retainer while covering the opened top surface of the lower retainer, forms an open passage communicating the second pressure chamber with the lower chamber in the high-frequency mode, and blocks the communication between the second pressure chamber and the lower chamber in the low-frequency mode due to the downward movement of the guide assembly.