Patent ID: 9611915
Date: 2017-04-04
CPC Classifications: F16F

Claim:
1. A valve structure of a shock absorber including a cylinder filled with a working fluid and a piston rod having one end located inside the cylinder and the other end extending outward from the cylinder, the valve structure comprising: a main piston valve assembly installed at one end of the piston rod and configured to operate in a state that the inside of the cylinder is divided into an upper chamber and a lower chamber, and generate a damping force varying according to a moving speed; and a frequency unit configured to move together with the main piston valve assembly and generate a damping force varying according to a frequency, wherein the frequency unit comprises: a hollow housing mounted at a lower end of the piston rod such that the housing is disposed under the main piston valve assembly; a free piston disposed to be vertically movable within the housing; an auxiliary valve assembly mounted at a lower end of the housing, and a communication hole formed in a lower sidewall of the housing to directly communicate an inner space of the housing with the lower chamber, such that the communication between the inner space of the housing and the lower chamber is blocked when the free piston moves downward, wherein the inner space of the housing is partitioned into an upper space and a lower space by the free piston, and the free piston has a through-hole that is opened during a low-frequency compression to allow the working fluid of to flow from the lower space to the upper space, and wherein the free piston includes a valve body that maintains the through-hole in a closed state when no external force is applied.