Patent ID: 7604101

Claim:
A damping force control valve, which includes a high pressure region in communication with a tension chamber of a cylinder and a low pressure region in communication with a reservoir chamber, and controls a damping force by adjusting pressure of a pilot chamber by orifices, each of which has a channel controlled to open or close by a spool, the damping force control valve comprising: a main valve installed between the high and low pressure regions and controlled to open or close according to pressure of the high pressure region, and an initial preload and pressure of the pilot chamber, the main valve allowing working fluid to flow from the high pressure region to the low pressure region when being opened; a first fixed orifice in fluid communication with the high pressure region; a first variable orifice configured to be in fluid communication with the first fixed orifice; a bypass channel configured to discharge the working fluid supplied by opening the first fixed orifice and the first variable orifice to the low pressure region, the first variable orifice making the first fixed orifice and the low pressure region communicate with each other; and a second variable orifice configured to facilitate fluid communication between the first fixed orifice and the pilot chamber; and a second fixed orifice to control the working fluid discharged to the low pressure region so that the working fluid supplied by opening the first fixed orifice and the second variable orifice controls a pressure of the pilot chamber, the second variable orifice making the first fixed orifice and the pilot chamber communicate with each other.