Patent ID: 8485326
Filing Date: 2013-07-16
Classification: F16F

Abstract:
1. A hydraulic shock absorber comprising: a cylinder tube having a first end wall and a second end wall at respective ends thereof in a direction of an axial line, and also having an intermediate wall between said end walls; a piston chamber and an adjusting chamber, which are formed in the cylinder tube between the intermediate wall and the first end wall and between the intermediate wall and the second end wall, respectively, so as to mutually communicate through a communicating part formed at the intermediate wall; oil sealed inside the piston chamber and the adjusting chamber in a pressurized state; a pressure control member which pressurizes the oil by operation from outside the cylinder tube so as to increase a pressurizing force of the oil, whose pressurized state lowers due to a reduction of an amount of the oil caused by operation of the shock absorber; a piston which moves in the direction of the axial line with a gap maintained through which the oil flows between an inner periphery of the piston chamber and an outer periphery of the piston in the piston chamber; a rod mounted on the piston to extend through the intermediate wall, the adjusting chamber and the second end wall, a leading end of which is introduced to the outside of the cylinder tube; an elastic member arranged in the adjusting chamber and formed of a foam made of synthetic rubber or a synthetic resin, whose volume varies according to a hydraulic pressure in the adjusting chamber, wherein the elastic member is compressed by the pressurizing force of the oil in an initial state where the rod resides at a non-operating position, so as to form a reservoir tank in the adjusting chamber due to a space created by the compression of the elastic member, the elastic member being extended and contracted elastically based on flowing in/flowing out of the oil into/from the reservoir tank during the operation of the rod.