Vibration damper with amplitude-selective damping force

US7523818B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

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

Key dates

• Filing date: Dec 7, 2005
• Grant date: Apr 28, 2009
• Expiry date: Mar 23, 2026

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 cylinder containing a damping medium, a piston rod which is axially movable in the cylinder, and a piston assembly arranged for axial movement in the damping medium, the piston assembly being connected to the piston rod and dividing the cylinder into a working space around the piston rod and a working space opposite the piston rod, the piston assembly includes a piston body having connecting channels for opposite directions of flow between the working spaces, and valve disks which open the channels in respective opposite directions. A pilot assembly includes an axially movable shifting ring which controls a flow connection between the working spaces as a function of movement of the piston rod, and a pair of stop surfaces which limit axial movement of the shifting ring, wherein the stop surfaces are independent of the piston body and the valve disks.