Patent attributes
A hydraulic vibration damper has a receiving pipe, a piston rod which projects into the receiving pipe at one end and which can be moved in an oscillating way in the receiving pipe, on the end, facing the receiving pipe, of which a working piston is disposed. The working piston comprises through-flow channels for the damping fluid which channels are effective in the pulling direction and pushing direction, and which working piston divides the inner chamber of the receiving pipe into a pulling chamber on the side of the piston rod and a pressure chamber remote from the piston rod, wherein at least a first through-flow channel can be covered to form a damping valve with a first resilient or spring-loaded valve washer which cooperates with a first valve seat. A pressure relief blow-off valve which comprises a blow-off function and opens when a predeterminable pressure level is achieved, has a first throttling site which produces progressively flowing damping force when there is increasing piston speed and whose throttling cross-section is variable depending on the piston speed of the vibration damper. In order to achieve a structurally simple construction and a low axial construction height of the valve, the pressure relief valve which has the blow-off function comprises a first annular washer allocated to the first valve washer, the first annular washer having a surface facing the first valve washer, the surface forming the variable first throttling site with the first valve washer.
