Frequency sensitive type shock absorber

A frequency sensitive type shock absorber comprising:

• 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 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;
• wherein the pilot valve is in contact with the upper portion of the main retainer during a low-frequency stroke, and is spaced apart from the upper portion of the main retainer to open the main chamber during a high-frequency stroke.

A frequency sensitive type shock absorber comprising:

• 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 in communication with the connecting passage;
• 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;
• and
• an inlet disc interposed between the housing and the pilot valve and having at least one slit communicating the connection passage and the pilot chamber.