Shock absorber with variable damping characteristics depending upon stroke speed

摘要

A shock absorber is provided a piston stroke dependent variable shock absorbing characteristics by means of a first and second flow restriction valves associated with a piston. The first and second flow restriction valves are arranged in a fluid path for communicating first and second working chambers defined within a shock absorber cylindrical housing in series. The first flow restriction valve is associated with an orifice forming a part of the fluid path and has variable flow restriction rate in response to a pressure difference between the first and second chambers greater. The second flow restriction means is disposed in tandem fashion with the first flow restriction valve for providing a predetermined constant flow restriction rate in response to the pressure difference smaller than a predetermined criterion and providing a variable flow restriction as a function of the piston stroke speed in response to the pressure difference greater than the predetermined criterion.