Liebherr-France Sas

Robert Bosch

Frank Helbling

Burkhard Knöll

Gerhard Kossmann

Albrecht Kessler

Günter Fertig

Josef Hessdörfer

Thomas Landmann

Cyril Graebling

A control device for controlling a hydraulic consumer, is equipped with a distributing valve having a control pressure chamber and a control slide that can be displaced against the force of a spring by the build-up of a control pressure in the control pressure chamber. A pilot control valve controls the supply and discharge of control fluid into and out of the control pressure chamber. A release device is used to drive the control fluid out of the control pressure chamber, bypassing the pilot control valve.

Control device and hydraulic pilot control

The present invention relates to a method for attenuating the motion of hydraulic cylinders of mobile work machinery, in particular of hydraulic excavators, in which prior to the hydraulic cylinder reaching one of the limits of travel, its motion speed is reduced, and the hydraulic cylinder is moved to the respective limit of travel at reduced speed; wherein for the purpose of reducing the speed, the inflow to, and/or the outflow from, the hydraulic cylinder are/is throttled by a flow control device. According to the invention, the method is characterized by, prior to the respective limit of travel being reached, the motion speed of the hydraulic cylinder is registered, and the point in time when throttling commences is changed depending on the registered motion speed. Furthermore, the present invention relates to a device for attenuating the motion of hydraulic cylinders of mobile work machinery, in particular of hydraulic excavators, a position registering device for registering a preliminary limit position of the hydraulic cylinder, a control device for throttling the inflow and/or outflow of the hydraulic cylinder, and a control device for controlling the flow control device when the preliminary limit position is reached. According the invention, the device has a speed registering device for registering the motion speed of the hydraulic cylinder when the preliminary limit position is reached, and the control device has a delay device for delaying driving the flow control device, depending on the recorded motion speed.

Method and device for attenuating the motion of hydraulic cylinders of mobile work machinery

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Sasbach, Germany

Frank Helbling