Abstract: Provided is a shock absorber, which has a cylinder filled with a fluid, a piston valve dividing the cylinder into a rebound chamber and a compression chamber, and a piston rod extending to the outside of the cylinder in a state of being connected to the piston valve. The shock absorber includes: a free piston which divides the compression chamber into an upper chamber and a lower chamber in such a state that the piston rod vertically passes through the free piston, and forms a vertical passage such that the upper chamber and the lower chamber are connected to each other; and a support which is connected to the piston rod, with a larger diameter, increases a pressure of the upper chamber by locally tightly contacting and ascending the free piston from below during a rebound stroke of the piston rod, and forms a horizontal passage connected to the vertical passage.

Abstract: Provided is a piston valve of a shock absorber which can achieve both an effect of varying an attenuation force according to a pressure and an effect of varying an attenuation force according to a frequency region. The piston valve includes: a main valve unit coupled to a lower end of a piston rod formed with an orifice hole, to divide an inside of a cylinder into an extension chamber and a compression chamber, the main valve unit generating an attenuation force according to a difference of pressure between the extension chamber and the compression chamber; and a frequency sensitive valve unit installed at one side of the main valve unit and configured to generate an attenuation force according to a frequency of hydraulic fluid delivered through the orifice hole of the piston rod, wherein the frequency sensitive valve unit is installed within the main valve unit.

Abstract: Provided is a shock absorber, which has a cylinder filled with a fluid, a piston valve dividing the cylinder into a rebound chamber and a compression chamber, and a piston rod extending to the outside of the cylinder in a state of being connected to the piston valve. The shock absorber includes: a free piston which divides the compression chamber into an upper chamber and a lower chamber in such a state that the piston rod vertically passes through the free piston, and forms a vertical passage such that the upper chamber and the lower chamber are connected to each other; and a support which is connected to the piston rod, with a larger diameter, increases a pressure of the upper chamber by locally tightly contacting and ascending the free piston from below during a rebound stroke of the piston rod, and forms a horizontal passage connected to the vertical passage.

Abstract: Provided is a piston valve of a shock absorber which can achieve both an effect of varying an attenuation force according to a pressure and an effect of varying an attenuation force according to a frequency region. The piston valve includes: a main valve unit coupled to a lower end of a piston rod formed with an orifice hole, to divide an inside of a cylinder into an extension chamber and a compression chamber, the main valve unit generating an attenuation force according to a difference of pressure between the extension chamber and the compression chamber; and a frequency sensitive valve unit installed at one side of the main valve unit and configured to generate an attenuation force according to a frequency of hydraulic fluid delivered through the orifice hole of the piston rod, wherein the frequency sensitive valve unit is installed within the main valve unit.