Patent ID: 7025184
Filing Date: 2006-04-11
Classification: B60G,F16F

Abstract:
1. A hydraulic shock absorber with a self leveling function for a vehicle height, comprising: a cylinder; a piston disposed in the cylinder to define two oil chambers in the cylinder; a piston rod connected to the piston; an outer tube disposed co-axially with the cylinder outside the cylinder; a partition wall member to divide a circular space between the cylinder and the outer tube to form a reservoir communicating with the oil chambers and a supplementary oil storage; and a pumping device which supplies an operating oil from the supplementary oil storage to the oil chambers caused by expansion/contraction movements of the piston rod to increase pressure in the cylinder, the hydraulic shock absorber further comprising: a flow passage disposed in the partition wall member to communicate the reservoir with the supplementary oil storage, the flow passage communicating with a press-fit bore formed in the partition wall member at a side of the supplementary oil storage; and a relief valve which opens the flow passage when pressure in the reservoir increases to more than a predetermined value, wherein the relief valve includes: a valve seat formed on a shoulder between the flow passage and the press-fit bore on the partition wall member and facing the side of the supplementary oil storage; a hollow valve case surrounding the valve seat and press-fitted at one end into the press-fit bore of the partition wall member, the hollow valve case being located entirely inside the supplementary oil storage; and a valve body disposed in the hollow valve case, the valve body being urged by a spring so as to be seated at the valve seat.