Disclosed is a frequency sensitive type shock absorber including a piston rod reciprocating an inside of a cylinder and having a connection passage therein; a piston valve mounted on the piston rod and having a plurality of compression and rebound flow paths penetrating up and down thereof, and partitioning the cylinder into compression and rebound chambers; and a valve assembly mounted on the piston rod to generate a damping force that changes with frequency during a rebound stroke; wherein the valve assembly comprises: a housing coupled to the piston rod and having a pilot chamber in communication with the connection passage; a main retainer coupled to the piston rod and having a main chamber formed on an upper portion thereof in communication with the connecting passage; and a pilot valve coupled to the piston rod and disposed between the housing and the main retainer to partition the pilot chamber and the main chamber.

Disclosed is a frequency sensitive type shock absorber including a piston rod reciprocating an inside of a cylinder and having a connection passage therein; a piston valve mounted on the piston rod and having a plurality of compression and rebound flow paths penetrating up and down thereof, and partitioning the cylinder into compression and rebound chambers; and a valve assembly mounted on the piston rod to generate a damping force that changes with frequency during a rebound stroke; wherein the valve assembly comprises a housing coupled to the piston rod and having a pilot chamber in communication with the connection passage; a main retainer coupled to the piston rod and having a main chamber formed on an upper portion thereof in communication with the connection passage; a first pilot valve coupled to the piston rod and disposed between the housing and the main retainer to partition the pilot chamber and the main chamber; and a second pilot valve coupled to the piston rod and disposed above the pilot chamber and configure to be elastically deformable depending on a change in pressure of the pilot chamber.

The hydraulic shock absorber includes: a first cylinder containing fluid; a piston body including extension-side oil paths permitting flow of oil along with relative movement of the piston rod in the axial direction of the first cylinder; and an extension-side damping valve configured to open and close the extension-side oil paths of the piston body. The extension-side damping valve includes: a valve plate configured to close the extension-side oil paths by covering them and open them by deforming under pressure of oil; and a preload member configured to apply a preload to the valve plate. The preload member includes: a ring-shaped portion; and axis alignment portions configured to protrude from an outer periphery of the ring-shaped portion and contact the piston body to thereby perform axis alignment.

A regulable vibration damper, which may be utilized in a vehicle chassis, for example, may comprise a cylinder barrel that contains hydraulic fluid in sealed-off fashion, a piston that is axially movable within the cylinder barrel along a cylinder barrel axis and that divides the cylinder barrel into two working chambers, and a piston rod oriented parallel to the cylinder barrel axis and that is connected to the piston. The piston may comprise at least two fluid leadthroughs that connect the working chambers. A first valve assembly for damping piston movement in a first actuation direction may be arranged at a first fluid leadthrough, and a second valve assembly for damping piston movement in a second actuation direction may be arranged at a second fluid leadthrough. In the piston, one or more bypass ducts with throughflow cross sections of different size for the two throughflow directions may form fluidic connections between the two working chambers that bypass the vestibules.

A hydraulic damper for a motor vehicle including a tube having a main section and a narrowed section. A main piston assembly is disposed inside the main section. A main piston rod is attached to the main piston assembly. A secondary rod is coupled with the main piston rod. A spring seat is disposed about the secondary rod. A spring engages the spring seat and preloads the spring seat. A secondary piston is disposed about and coupled with the secondary rod. The secondary piston has an axial projection and an annular projection that abuts the spring seat. The annular projection defines a plurality of axial slots. A retaining member is fixed to the secondary rod and has an outer face defining a plurality of radial slots. A sealing ring is slidably disposed about the axial projection. An annular channel is defined radially between the sealing ring and the axial projection.

One embodiment provides a pressure buffer device including: a cylinder that stores fluid; a flow path forming portion that forms a flow path; and an opening-closing portion that opens and closes the flow path of the flow path forming portion. The fluid flows through the flow path forming portion in accordance with relative movement of a rod with respect to the cylinder in an axial direction of the cylinder. The flow path forming portion includes an annular first protruded portion and an annular second protruded portion protruded in the axial direction in opposite sides respectively. The second protruded portion has an axial end located at a radially outer side of the first protruded portion, and a tilt portion formed at least at a part of a radially-inner part of the second protruded portion.

A shock absorber for a vehicle includes a pressure tube that defines a fluid chamber and a piston disposed within the fluid chamber. The piston divides the fluid chamber into an upper working chamber and a lower working chamber, and defines a compression passage and a rebound passage. A valve disc assembly of the shock absorber engages the piston and controls the flow of fluid between the upper and lower working chambers. The valve disc assembly includes a check disc and an orifice disc. The check disc is disposed between the piston and the orifice disc. The orifice disc defines an orifice, and the check disc prohibits the flow of fluid through the orifice as the fluid flows in a first direction and permits the flow of fluid through the orifice as the fluid flows in a second direction opposite of the first direction.

A damping force controlling shock absorber includes: retainers respectively connected to top and bottom surfaces of the piston, a connection passage communicating with a main passage being formed to vertically penetrate the retainers; housings respectively disposed on corresponding opposite surfaces of the retainers to form pilot chambers on mutual corresponding surfaces of the housings, a pilot passage being formed to vertically penetrate the housings so as to communicate the pilot chambers with the outside; pilot valves that are in close contact with the connection passage between the retainers and the housings to generate a main damping force; and a spool guide that penetrate and connects to the retainers, the housings, and the pilot valves and guides the spool in a state of surrounding the outside of the spool.

A hydraulic damper (2) includes a first piston body member (233), a second piston body member (234), a third piston body member (235), and a compression stroke disc assembly (231) compressed at a radially inner side thereof between the first (233) and said second (234) piston body members. The hydraulic damper includes a rebound stroke disc assembly (232) compressed at the radially inner side thereof between the second (234) and third (235) piston body members, and the compression stroke disc assembly (231) additionally includes an annular supporting member (2319) positioning discs (2311-2318) of the compression stroke disc assembly (231) at radially inner side thereof, while a radially inner axial passage (23191) is defined at the radially inner side of the supporting member (2319).

Provided on one plane of an annular piston are a sheet surface on which a leaf valve is seated and a supporting part constructed of a slope part and a flange part, and provided on the other plane is a leg part having a depression on an edge part. When two pistons are axially stacked, the sheet surface of one of the pistons is contained inside the depression of the other piston, and the sheet surface of the one piston is protected.