Vibration damper with amplitude-selective damping force

US7726451B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Thomas Hammer · Iserlohn, DE
• Michael Doppernas · Priesendorf, DE
• Manfred Denner · Pfronten, DE
• Matthias Planitzer · Schweinfurt, DE

Key dates

• Filing date: Sep 21, 2006
• Grant date: Jun 1, 2010
• Expiry date: Aug 1, 2028

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16F9/512
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A vibration damper with amplitude-selective damping force includes a piston rod carrying a piston arrangement axially movably arranged in a cylinder and dividing the cylinder into two working spaces. A flow connection is present between the working spaces and controlled by an axially movable switching ring which cooperates with a working surface which faces the ring to define a pilot opening cross section. A bypass channel with at least two connecting openings to the flow connection is provided hydraulically in parallel to the flow connection. At least one connecting opening upstream of each of two stop surface of the switching ring. A check valve arrangement separates the bypass channel and the flow connection from each other in the different flow directions as a function of the movements of the piston rod, the check valve arrangement having two check valves which close in opposite directions.