Vibration damper with stroke-dependent damping force

US8479895B2 · kind B2 · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Steffen Heyn · Niederwerrn, DE
• Bernd Zeissner · Volkach, DE

Key dates

• Filing date: Mar 16, 2011
• Grant date: Jul 9, 2013
• Expiry date: Jul 13, 2031

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 stroke-dependent damping force includes a cylinder in which a piston rod with a piston is axially movable. The piston divides the cylinder into two work spaces filled with damping medium. A bypass between the work spaces is opened or closed depending on the piston position. The piston has a damping valve for at least one through-flow direction formed by a valve body that partially covers a through-flow channel in the damping valve. The valve body has first and second pressure-actuated surfaces on opposite sides of the valve body. The action of the second pressure-actuated surface depends on the position of the piston in relation to the bypass. The first pressure-actuated surface exerts a lifting force and the second pressure-actuated surface exerts a closing force on the valve disk. The second pressure-actuated surface is connected to a control space and a connection channel that overlaps with the bypass depending on the stroke position of the piston.