Fichtel & Sachs Ag

Zf Friedrichshafen Ag

Mannesmann Sachs Ag

Continental Aktiengesellschaft

Zf Sachs Ag

Thomas Kutsche

Heinz-Joachim Gilsdorf

Alfred Wirth

Udo Borschert

Steffen Heyn

Norbert Heinz

Joachim K&uuml;hnel

Thomas Manger

Alexander Stiller

Achim Thomae

Stefan Rappelt

Jörg Grotendorst

Christian Maurischat

Andreas Föster

Stefan Sommer

Manfred Roder

Fritz Wolf

Thorsten Asshoff

Thorsten Assiioff

Wolfgang Schumacher

Eberhard Hees

The vibration damper with an adjustable damping force includes a cylinder filled with a damping medium, a piston rod axially movable in the cylinder and carrying a piston which divides the cylinder into a first working space on the piston rod side and a second working space on the side away from the piston rod, a first adjustable damping valve which is connected to at least one of the two working spaces by means of a fluid connection, at least one second valve which is connected hydraulically in parallel to the first adjustable damping valve, and a third damping valve arranged in series to and upstream from both the first and second valves, the third damping valve moving in a closing direction as a function of a flow velocity of the damping medium through the third damping valve.

Vibration damper with adjustable damping force

A first acceleration sensor is arranged on a vehicle body for detecting an acceleration signal of the vehicle body and a second acceleration sensor is arranged on a wheel-side axle part for detecting an acceleration signal of the wheel-side axle part, the vehicle body and the wheel-side axle part execute relative movement with respect to each other. The wheel acceleration signal and the body acceleration signal are each integrated twice to form respective distance signals. The difference between the two distance signals at a first time (t) is determined and stored as a gap value. A second distance signal difference is determined at a second time (t) for a new gap value. When the wheel-side axle part reaches a reference position with respect to the vehicle body during the relative movement between the axle part on the wheel side and the vehicle body, a switching signal is generated and is used as a reference signal for determining the absolute position of the wheel side axle part along with the difference calculations.

Method for determining the absolute position of a movable component

One or several vibration dampers of a vehicle suspension have a damping force arrangement wherein a control signal is computed within the actuating range in accordance with a standard control method for adjusting the damper characteristic. The drive of a damper adjustable in accordance with this invention is so improved that body movements (notwithstanding a harder adjusted damping for critical driving situations) are substantially suppressed as early as possible. In specific driving situations, the adjusting range of the damper force is changed in that the upper limit of the adjusting range is raised or lowered and/or the lower limit of the adjusting range is raised or lowered. A soft damper setting takes place preferably in dependence upon signals which announce or display a change of the vehicle longitudinal deceleration or vehicle transverse acceleration.

Electrically adjustable semiactive damper control

An adjustable vibration damper, having a displacer in a cylinder, a damping medium exerting a damping force via an adjustable damping valve. The adjustable damping valve is activated by a control pressure of a pneumatic spring A safety device is provided which, in the event of a control pressure reduced as a result of damage to the pneumatic spring, provides a sufficiently high damping force of the vibration damper. At least two pneumatic springs are connected to the safety device, which is constructed from a pneumatic circuit functioning as a pressure balance between the pneumatic springs which releases the higher control pressure of a pneumatic spring in the pneumatic circuit. The adjustable vibration dampers which belong to the pneumatic springs are connected via at least one pressure outlet connection of the pneumatic circuit and are activated by the highest control pressure of the pneumatic springs involved.

Adjustable vibration damper with safety device

A pressure operated valve is provided including an adjusting device, a spring and a vent connection. The adjusting device is axially movably arranged in a pressure chamber defined in the valve and comprises a valve body and a pressure intensifier. A space between the valve body and valve face defines a valve passage cross section. The spring is operatively arranged for holding the pressure intensifier in a floating arrangement in the pressure chamber. The pressure intensifier has a first side exposed to a pressure in the pressure connection opening and a second side facing away from the pressure connection opening. The second side of the pressure intensifier and the adjusting device define a low pressure chamber within the pressure chamber. The vent connection is an inflow restrictor arranged between the lower pressure chamber and a space having a lower pressure than the low pressure chamber.

Valve which reacts as a function of pressure, especially for a vibration damper

A system to control a chassis vibration damping device with a variable damping characteristic in a vehicle with the use of a single acceleration sensor and a subsequent processing of the signal by means of filters and of an additional signal of a primary detector, whereby the processing corresponds to a breakdown of the acceleration signal into its individual components which relate to the longitudinal, transverse and vertical axes of the vehicle.

System to control a chassis vibration damping device

For control of a frame-vibration damping device with a variable damping force characteristic in a motor vehicle (1), adjustment devices (9) of the vibration dampers (7) being controlled as a function of evaluated measurement signals of a single acceleration sensor (17) detecting the instantaneous value of an acceleration variable. The measurement direction (19) of the acceleration sensor (17) is turned at an angle of 45.degree. in each case to the three axes of motion of the vehicle (longitudinal axis x, transverse axis y, and vertical axis z). Signal separation means (25) separate a first measurement signal component (b.sub.z) by means of a bandpass filter (31) with midfrequency tuned to the natural frequency of the vehicle body (3), which represents the acceleration component in the vertical direction (z). Subtraction means (33), which develop the difference of the measurement signal of the acceleration sensor (17) and the first measurement signal component (b.sub.z), deliver a second measurement signal component (b.sub.xy) for the acceleration component in the plane of the longitudinal axis x and the transverse axis y. Evaluation means (35, 37) associated with the two measurement signal components deliver damping force requirement components n.sub.Z and n.sub.xy which are added by adding means (39) to obtain a control signal which controls the adjusting device (9) representing the entire damping force requirement.

Arrangement for control of a chassis vibration damping device

According to an embodiment of the invention it is proposed, for determining the weight of the useful load on a vehicle, that the height of the vehicle body above the chassis be determined, this height be compared with a threshold value and that a switch is made between a hard damping characteristic (for a heavy useful load) and a soft damping characteristic (for a light useful load) in a springing and damping system depending on the sign of the deviation from the threshold value.

Load-sensitive vehicular suspension system

The process according to the invention allows the adjustment of different damping characteristics of a motor vehicle damper taking into account the state of travel of the motor vehicle and damping requirement defining quantities depending on the travelling state according to an operating mode which can be preselected by the driver. The switch takes place as a function of a value of the total damping requirement determined from the instantaneous values of the damping requirement defining quantities according to a power function. The damping characteristic which is most desirable at each moment in time can be defined in real time. The process according to the invention can be used for various vehicles owing to adaptation of parameters which determine the power function.

Growing community of inventors

Schweinfurt, Germany

Thomas Kutsche