Zf Friedrichshafen Ag

Zf Freidrichshafen Ag

Steffen Heyn

Helmut Baalmann

Andreas Förster

Bernd Zeissner

Achim Thomae

Michael Triebel

Norbert Ackermann

Holger Kirchner

Jörg Rösseler

Thomas Manger

Aleksandar Knezevic

Thomas Thein

Hendrik Marquar

Robert Pradel

Alexander Schwarz

Oswald Lichtlein

Christian Maurischat

Frank Gundermann

Sven Greger

Jens Seiler

Anke Sonnemann

Joachim Gajek

Wilhelm-Heinrich Broocks

Sven Philip Krüger

Manfred Grundei

Heinz-Joachim Gilsdorf

Stefan Rappelt

Wolfgang Breun

Klaus Sauer

Guido Holtmann

Andreas Föster

Anton Krawczyk

Christian Böhm

Ludwig Gampl

Holger Beyer

Lothar Callies

Markus Güther

Andreas Foerster

Uwe Boecker

Herbert Bies

Michael Hegmann

Stefen Rappelt

A throttle point for a vibration damper, comprising a damper valve carrier with a circumferential annular groove, in which an annular valve body with a variable diameter is arranged. The annular valve body forms, with a guiding face for flowing damping medium, a throttle point, a throttle cross section of which decreases in the case of an increasing flow velocity of the damping medium within the throttle point. The circumferential annular groove forming a pressure chamber which is filled with damping medium. A radially outwardly directed actuating force acts on the valve body, wherein the pressure chamber is a constituent part of a hydraulic system which has a connector to at least one working space of the vibration damper and the hydraulic connection of which to the pressure chamber can be set.

Throttle point with a valve body with a changing diameter

A damping valve includes a damping valve body with an annular groove which has a base and which is limited by an inner valve seat surface and an outer valve seat surface for at least one valve disk. The base of the annular groove has a maximum distance from the valve seat surface along a circumferential area and has a minimum axial distance from the valve seat surface in another circumferential area.

Damping valve for a vibration damper

A method for operating a motor vehicle with a chassis arrangement having at least two vibration dampers. A body control is carried out at least partially with the vibration dampers. The chassis arrangement further has at least one stabilizer. During transverse accelerations below a threshold acceleration the stabilizer contributes to the body control less than the vibration dampers and contributes more than the vibration dampers from the threshold acceleration upward.

Method for operating a motor vehicle, method for roll compensation of a motor vehicle, and motor vehicle

A method of operating a motor vehicle with a chassis system comprising at least two, preferably four vibration damper includes carrying out a body control and a wheel control with the chassis system, and controlling the energy supply for the chassis system via an energy control arrangement. A motor vehicle performing the method is also disclosed.

Method of operating a motor vehicle, and motor vehicle

A vibration damper with a piston, a piston rod fastened to the piston, a working chamber divided by the piston into a first working chamber and second working chamber, and a generator drivable by movement of the piston rod. The damping force of the vibration damper can be influenced by energization of the generator. An energizable component part is provided that short-circuits the windings of the generator when unenergized and cancels the short circuit when energized.

Vibration damper and motor vehicle

Energy-recuperating vibration damper having a cylinder in which a displacer executes a limited operating movement in a working chamber so that a pressurized fluid is supplied to a fluid motor which drives a generator. A compensation chamber compensates for a change in volume of the pressurized fluid. A pressure accumulator is provided in addition to the compensation chamber, which pressure accumulator communicates with and is parallel-connected to the fluid motor.

Energy-recuperating fluid vibration damper

Adjustable damping valve for a vibration damper having a valve body having a pressure-loaded surface that acts in the lifting direction of the valve body and is impinged by an incident flow of damping medium from an opening inside a cross section limited by valve seat surface, and a surface operative in the closing direction is formed by a rear side of the valve body. A resulting force including a force of at least one valve spring and an actuating force of an actuator acts on the valve body. An additional surface of the valve body is pressure-loaded by damping medium by incident flow on the valve body in the closing direction of the valve body, or the valve body has a first pressure-loaded surface acting in the lifting direction, and a second pressure-loaded surface that acts in the lifting direction.

Adjustable damping valve

An adjustable damping valve arrangement for a vibration damper comprises an actuator which exerts an actuating force on an auxiliary valve body of an auxiliary valve. The auxiliary valve influences a closing force on a main stage valve. A pressure depending on the pressure level in a working space of the vibration damper acts on at least one pressure-impinged closing surface of the main stage valve via a flow connection. The flow connection is carried out so as to be functionally parallel to an incident flow of the main stage valve, and a flow-in opening of the flow connection is oriented at an angle of at least 60&#xb0; to the flow direction into the main stage valve so that only a static pressure acts on the closing surface of the main stage valve.

Adjustable damping valve arrangement

An adjustable damping valve device for a vibration damper includes a housing with an axially movable valve body. The valve body has in the direction of a valve seat surface a pressure-loaded surface Awhich is operative in the lift direction of the valve body and a surface Awhich is loaded by pressure in the closing direction, wherein a resultant force comprising a force of at least one valve spring and an actuating force of an actuator acts on the valve body, and wherein an additional surface Aof the valve body is pressure loaded by damping medium in closing direction of the valve body. The damping valve device has an emergency operation valve by means of which a pressure level can be at least indirectly adjusted in a control space for an emergency operation. The emergency operation valve is operative only in one flow direction.

Adjustable damping valve device having an emergency operation valve

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.

Vibration damper with stroke-dependent damping force

Disclosed is a vibration damper comprising a cylinder in which a piston rod is guided in an axially movable manner. A first piston is mounted stationarily on the piston rod while a second piston that is equipped with at least one valve disk biased by a spring assembly is mounted on the piston rod so as to be axially movable counter to a force of at least one support spring. The spring assembly is provided with at least one spring plate on which the spring assembly rests. The second piston is retained by a fixing sleeve which supports the at least one spring plate. The structural unit encompassing the fixing sleeve and the at least one spring plate is fitted with an axially effective separating joint for a locking connection inside the structural unit. The entire structural unit can be axially displaced towards the at least one support spring.

Vibration damper

An adjustable damping valve including an actuator, which exerts an actuating force on a valve body against the force of a spring to influence the throttle cross section which determines the damping force, where an emergency valve is connected in parallel with the throttle cross section with respect to the flow direction of the damping medium, where the two control surfaces of the valve body move in the axial direction and can thus can come to rest alternately on the two valve seating surfaces, and where the valve body is divided into two parts in the longitudinal direction, and each valve body assembly has its own control surface.

Adjustable damping valve with a fail-safe damping force characteristic

A damping valve for a vibration damper includes a guide sleeve which slides on the piston rod of a vibration damper. An annular damping valve body which is provided with at least one through-opening is fixed axially by positive engagement on the guide sleeve, and the through-opening is covered at least partly by at least one valve disk which is biased by at least one closing spring which is supported at its end at a spring plate connected to the guide sleeve. The damping valve body and a spring plate which is constructed separate from the guide sleeve form a compression chain between two axially spaced stops of the guide sleeve.

A piston rod with a piston is installed with freedom of axial movement in a damping medium-filled cylinder, where, as a function of the stroke position of the piston, a bypass connects the two working spaces separated from each other by the piston. The piston has at least one through-channel for at least one flow direction, which channel is at least partially covered on the outlet side by at least one valve disk, so that a first pressure-actuated surface to which pressure can be applied in the opening direction is present on the valve disk. In addition to the first pressure-actuated surface, the valve disk has a second pressure-actuated surface, which is separated from the first when the valve disk is closed and which can be actuated via the bypass, in which case the effects of the two pressure-actuated surfaces are additive. The second pressure-actuated surface of the valve disk, in addition to the first pressure-actuated surface of the valve disk, is designed with its throttle point in the area of the second pressure-actuated surface at least during a certain phase of the travel of the valve disk.

Growing community of inventors

Niederwerrn, Germany

Steffen Heyn