HYDRAULIC SHOCK ABSORBER WITH A SELF-ADJUSTMENT FUNCTION FOR VEHICLE HEIGHT FOR PREVENTING A VALVE CASE FROM DROPPING FROM A DIVIDING WALL MEMBER AND BREAKAGE CAUSED IN BUMPING AGAINST A ROD GUIDE AND A HEAD CAP

摘要

PURPOSE: A hydraulic shock absorber with a self-adjustment function for vehicle height is provided to prevent a valve case from dropping from a pressure fitting bore of a dividing wall member even in receiving excessive shock pressure. CONSTITUTION: A hydraulic shock absorber with a self-adjustment function for vehicle height is composed of a cylinder(20); a piston(22) installed in the cylinder to define two oil chambers(51,52) in the cylinder; an outer tube(30) arranged at the outside of the cylinder on the coaxial line of the cylinder; a dividing wall member(111) for dividing a circular space between the cylinder and the outer tube to form a storage tank(81) communicating with an oil pressure chamber and an auxiliary oil reservoir(82); a pumping unit for supplying actuating oil from the auxiliary oil reservoir into the oil chamber according to expansion/contraction of a piston rod(21) to increase pressure of the cylinder; a flow-passage(113) formed in the dividing wall member to communicate the storage tank with the auxiliary oil reservoir; and a relief valve(100) for opening the flow-passage when the internal pressure of the storage tank is increased over a predetermined value. The relief valve comprises a valve seat(103) arranged continuously in the flow-passage to confront a lateral side of the auxiliary oil reservoir; a hollow valve case(101) fitted into the dividing wall member at one end to surround the valve seat; and a valve body(104) pressurized by a spring(106) to place on the valve seat and disposed in the hollow valve case.