Shock absorber with adjustable damping force.

摘要

A shock absorber which selectively produces different magnitudes of damping forces includes a cylinder (3) and a piston (17) slidably disposed in the cylinder and dividing an interior space of the cylinder into first (19) and second fluid (21) chambers filled with a fluid. A housing assembly (15) coupled to the piston has a main fluid passage (31) providing fluid communication between the first and second fluid chambers at all times and an auxiliary fluid passage (41) providing selective fluid communication between the first and second fluid chambers. The auxiliary fluid passage can be opened to provide fluid communication between the first and second fluid chambers in response to an external control signal. The auxiliary fluid passage can be closed to cut off fluid communication between the first and second fluid chambers when the speed of relative movement of the cylinder and the piston is other than substantially zero, i.e., when the speed of expansion and contraction of the shock absorber is substantially zero.