Suspension system for motor vehicles and damping valve

摘要

The present invention relates to a suspension system, especially for motor vehicles, with at least one hydraulic spring strut (2/4). When the spring strut (2/4) is compressed, hydraulic medium is displaced into a spring energy store (16/18), from which it flows back again during the rebound. At least the rebound flow of the spring strut (2/4) is led by way of a flow path (26) of a damping valve (22/24) and damped in that the flow path (26) is constantly alternately closed and re-opened by means of a valve element (30). At the same time, a bypass (40) bypassing the valve element (30) is provided, in such a way that in an essentially zero-flow condition, pressure equalisation between the sections of the flow path (26) arranged on both sides of the valve element (30) is ensured by way of the bypass (40) and when a flow occurs the bypass (40) essentially loses this pressure equalising function. The bypass (40) is opened or closed by a sealing device (44) controllable as a function of the respective flow and/or pressure conditions. For this purpose the sealing device (44) has a step piston (80) which is guided in a freely movable way and pressure-equalised in such a way that the sealing device (44) in the static, essentially zero-flow condition has a tendency to open and in the dynamic condition a tendency to close due to the flow-induced variation of the pressure conditions.