Abstract: A shock absorber is provided. A first piston, a pilot valve, a second piston, and a rebound retainer are sequentially connected to a piston rod reciprocating within a cylinder. An upper portion of the second piston is provided inside the first piston. Due to a first compression chamber formed in the first piston, a second compression chamber formed in the second piston, a third compression chamber formed between the first piston and the second piston, and a fourth compression chamber formed in the rebound retainer, it is possible to improve a ride comfort by reducing a damping force over periods from an ultra-low-speed period to a high-speed period and it is possible to achieve the compact configuration and the cost reduction by reducing the overall length of the processing portion.

Abstract: A valve assembly of a shock absorber can achieve both an effect of varying an attenuation force according to a frequency region of vibration or shock transferred to the shock absorber during the driving of an automobile and an effect of varying an attenuation force according to an additional pressure and can increase the attenuation force in response to an instantaneous input of a large amplitude behavior. The valve assembly includes: a valve housing coupled to a piston rod having an orifice hole and a space formed therein, the space having an open lower end to communicate with the orifice hole; a frequency sensitive valve unit including a free piston configured to vertically partition the space; and a sub-valve unit coupled to the lower end of the space, wherein operation of the sub-valve unit is controlled by ascending and descending of the free piston.

Abstract: Disclosed herein is a piston assembly of a shock absorber which ensures easy and prompt connection of components in the correct positions in assembling the piston assembly of a shock absorber by forming a seating unit between a piston body and a compression retainer and between the piston body and a tension retainer.

Abstract: In a high-frequency mode (a small-amplitude mode), a shock absorber opens a guide member to reduce a damping force. In a low-frequency mode (a large-amplitude mode), the shock absorber prevents the guide member from being opened by increasing a pressure of a second pressure chamber formed between a second piston (lower piston) and a pilot valve through a groove (passage) formed in an outer periphery of a piston rod. A main damping force is generated through the second pressure chamber and a disk valve assembly. Therefore, it is possible to provide a round ride comfort having a damping feeling and ensure a steering stability through a linear vehicle control.

Abstract: A piston valve assembly for a shock absorber is disclosed. In a high-frequency mode, a damping force control is achieved through an open passage that is always opened. In a low-frequency mode, a guide assembly moves downward due to an increase in a pressure of a first pressure chamber by a fluid moved through an inlet hole of the first pressure chamber. At this time, the guide assembly blocks the open passage and the damping force control is achieved through only a rebound passage. Consequently, it is possible to solve a fluid bottle neck through a passage formation. A disk is installed on the inlet hole to prevent a continuous increase in the pressure of the first pressure chamber, thereby effectively preventing the reduction of the damping force.

Abstract: A frequency/pressure sensitive shock absorber for generating a damping force varying according to a frequency and a pressure-includes: a cylinder filled with a working fluid; a piston rod having one end located inside the cylinder and the other end extending outward from the cylinder; 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 sensitive unit installed at one end of the piston rod under the main piston valve assembly and configured to generate a damping force varying according to a frequency and a pressure.

Abstract: A frequency sensitive type shock absorber is provided. A housing has a bypass hole formed such that an upper portion of a chamber part is opened to connect to the opening, and a lower portion of the chamber part communicates with the compression chamber. A spool is formed within the chamber part and is elevated by a fluid flowing into the chamber part. A pair of partition members partitions the chamber part into upper and lower chambers and provides a restoring force to the spool. A guide member is formed between the pair of the partition members, has a elastic force, and guides the partition members to maintain positions thereof. A pair of elastic members is formed in the upper and lower chambers to prevent a fluid from penetrating between the pair of the partition members and the side of the chamber part, and assist a restoration of the partition members by elasticity.

Abstract: A shock absorber is provided. A first piston, a pilot valve, a second piston, and a rebound retainer are sequentially connected to a piston rod reciprocating within a cylinder. An upper portion of the second piston is provided inside the first piston. Due to a first compression chamber formed in the first piston, a second compression chamber formed in the second piston, a third compression chamber formed between the first piston and the second piston, and a fourth compression chamber formed in the rebound retainer, it is possible to improve a ride comfort by reducing a damping force over periods from an ultra-low-speed period to a high-speed period and it is possible to achieve the compact configuration and the cost reduction by reducing the overall length of the processing portion.

Abstract: A valve assembly of a shock absorber can achieve both an effect of varying an attenuation force according to a frequency region of vibration or shock transferred to the shock absorber during the driving of an automobile and an effect of varying an attenuation force according to an additional pressure and can increase the attenuation force in response to an instantaneous input of a large amplitude behavior. The valve assembly includes: a valve housing coupled to a piston rod having an orifice hole and a space formed therein, the space having an open lower end to communicate with the orifice hole; a frequency sensitive valve unit including a free piston configured to vertically partition the space; and a sub-valve unit coupled to the lower end of the space, wherein operation of the sub-valve unit is controlled by ascending and descending of the free piston.

Abstract: Disclosed herein is a piston assembly of a shock absorber which ensures easy and prompt connection of components in the correct positions in assembling the piston assembly of a shock absorber by forming a seating unit between a piston body and a compression retainer and between the piston body and a tension retainer.

Abstract: A frequency/pressure sensitive shock absorber for generating a damping force varying according to a frequency and a pressure-includes: a cylinder filled with a working fluid; a piston rod having one end located inside the cylinder and the other end extending outward from the cylinder; 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 sensitive unit installed at one end of the piston rod under the main piston valve assembly and configured to generate a damping force varying according to a frequency and a pressure.

Abstract: There is provided a sealing structure for hermetically sealing a gap between a base valve and an internal cylinder in a self leveling damper, which includes internal and external cylinders, a piston valve and a piston rod provided in the internal cylinder, and a base valve provided in a distal end of the internal cylinder, to absorb vibration transmitted from a road to an axle when a vehicle is driven, wherein a quadrangular-sectioned O-ring is inserted into a circular groove formed on a body of the base valve to hermetically seal the gap between the base valve and the internal cylinder.

Abstract: An apparatus and method for blocking access to undesirable web sites by central control at a network provider's side according to the subscriber requests are disclosed, in which the apparatus reduces time and expenditure for managing the subscriber side and allows the subscriber to use the Internet without anxiety of access to undesirable web sites. The apparatus according to the present invention comprises a central control center for specifying and providing a control list of undesirable web sites to be blocked, a plurality of remote control units for blocking access to the undesirable web sites on the basis of the control list, and a link control network for controlling the connection of the plurality of remote control units and the central control center.

Abstract: An unwholesome site blocking apparatus and method for blocking access to unwholesome information by central control at a network provider's side according to the subscriber's requests, thereby reduces the time and expenditure for managing the access in the subscriber's side and allows using the Internet safely. The apparatus comprises a central control center for specifying and providing a control list of unwholesome sites to be blocked and managing subscribers, a plurality of remote control units disposed between Internet Service Providers(ISP) and subscribers for blocking an access to the unwholesome sites on the basis of the control list to be blocked supplied from the central control center when the subscriber attempts to access to unwholesome sites, and a link control network for controlling the connection of the plurality of remote control units and the central control center.