Hydraulic damper

Abstract

A hydraulic damper according to the present invention includes a cylinder, working fluid disposed in the cylinder, a piston partitioning the cylinder into two fluid chambers and including passages therethrough for providing fluid communication between the two fluid chambers, and a damping force generation mechanism. The damping force generation mechanism includes a large diameter valve disc mounted adjacent the passages, a smaller diameter valve disc stacked against the large diameter valve disc, an inner pressure chamber formed adjacent and in fluid communication with the passages, and an outer pressure chamber formed adjacent and in fluid communication with the passages and formed radially outwardly of the inner pressure chamber. A partition wall is formed between the inner and outer pressure chambers and a passage is formed through the partition wall for communicating between the inner and outer pressure chambers. The outer pressure chamber is formed of a plurality of chambers spaced circumferentially about a longitudinal axis of the cylinder. In an alternative embodiment, rather than utilizing two separate valve discs, a single valve disc can be used in combination with a biasing spring for biasing the valve disc toward the inner and outer pressure chambers.