Danfoss Power Solutions Aps

Danfpss Power Solutions Aps

Sauer Danfoss Aps

Morten Hoeck Petersen

Svend Erik Thomsen

Niels Bjarne Hansen

Jens Vester

Nils E Sevelsted

Thomas Bauer

Poul Ennemark

Tom Rudolph

Bendt Porskrog

Helle Bonde Rasmussen

Thomas Traeger Hansen

Soren Pedersen

Jeroen Hinse

Thomas Træger Hansen

Søren Pedersen

Oktay Goece

A hydraulic steering system () includes a steering command device () having a steering sensor (), a steering motor (), a wheel sensor (), a pressure source (P), and control means () controlling a fluid supply from the pressure source (P) to the steering motor (), wherein the control means () has an open loop control (). Such a steering system should have a good relationship between steering input from the operator and steering behaviour of the vehicle to be steered. To this end the control means () include in addition to the open loop control () a closed loop control (), wherein cross-over transition means () are provided which are connected to the open loop control () and to the closed loop control () and control a transition between the open loop control () and the closed loop control ().

Hydraulic steering system

A hydraulic steering arrangement includes a supply port arrangement having at least a supply port, a return port arrangement having at least a return port, a working port arrangement having two working ports, a first valve arrangement having a first supply side connected to the supply port arrangement and a first output side connected to the working port arrangement, a second valve arrangement having a second supply side connected to the supply port arrangement and a second output side connected to the working port arrangement, and a steering command device. In a neutral steering angle, the second valve arrangement connects the first output side to the return port arrangement and the first valve arrangement connects the second output side to the return port arrangement.

Hydraulic steering arrangement

A hydraulic steering arrangement () comprising a supply port arrangement having a pressure port and a tank port, a working port arrangement having two working ports (L, R), a mechanical steering unit () connected to a steering wheel () and being arranged between the supply port arrangement and the working port arrangement (L, R), supply valve means () having a connection to the pressure port and to the working port arrangement (L, R) and being controlled by a controller (), and a steering wheel sensor () connected to the controller () is described. Such a steering arrangement could allow a comfortable feeling for the driver. To this end the steering wheel sensor () is mounted in a position of minimum play to steering wheel () and steering wheel sensor () and detects a beginning of a movement of the steering wheel (), wherein the controller () actuates the supply valve means () upon beginning of the movement, and the supply valve means () supply hydraulic fluid to the working port arrangement (L, R).

Hydraulic steering () is disclosed comprising a high pressure port (P), a low pressure port (T), two working ports (CL, CR), a manual steering section (), and a steering valve section having a steering valveand a hydraulic driving arrangement () adjusting hydraulically a position of said steering valve. A change from automatic steering to manual steering should be reliably ensured when the manual steering section is directly influenced by a driver. To this end, a switching valve () is provided, which is actuatable between a first position in which said driving arrangement () is supplied with hydraulic fluid under pressure, and a second position in which a supply of hydraulic fluid to said driving arrangement () is interrupted, wherein said switching valve () is hydraulically actuated into said second position by a pressure generated upon actuating of said manual steering section ().

Hydraulic steering

A hydraulic steering device is provided comprising a supply port arrangement having a supply port (P) and a return port (T), a working port arrangement having two working ports (L, R), direction valve means () arranged between said supply port arrangement and said working port arrangement, at least two fluid meters (), each of said fluid meters () having a movable metering element (), said metering elements () being connected by a shaft (), said shaft () having an axis, selector valve means () being provided, said selector valve means () in a first position arranging said fluid meters () hydraulically in parallel and in a second position shutting off one of said fluid meters (), said selector valve means () having a valve element () shiftable in an direction parallel to said axis. It is an object to reduce wear in said hydraulic steering device in a simple manner. To this end said selector valve means () are arranged between said two fluid meters (), said shaft () extending through said valve element ().

Hydraulic steering device

A method for controlling steering of a vehicle () is provided, the vehicle () defining two or more steerable axes, and the vehicle () comprising a number of wheels (), each of said wheels () being associated with one of said steerable axes in such a manner that steering of a given wheel () is obtained by steering the steerable axis associated therewith. The method comprises providing a first, a second and a third steering input. The first steering input defines a point of intersection between a virtual steering axis () and a longitudinal center axis defined by the vehicle (). The second steering input defines an angle between the virtual steering axis () and the longitudinal center axis. The third steering input defines a position of a center of rotation () along the virtual steering axis (). A position for each of the steerable axes defined by the vehicle () is calculated, which causes the vehicle () to rotate about the center of rotation () defined by the first, second and third steering inputs, and each of the steerable axes is moved to the calculated position.

Method for controlling steering of a vehicle

A hydraulic control arrangement () is described having a directional valve (), a metering pump unit which has at least two metering pumps () which are connected hydraulically in parallel and are operable mechanically in parallel, and a shut-off valve () in hydraulic connection between two of the at least two metering pumps (), a pump connection (P) and a tank connection (T) which are connected to said metering pump unit by way of the directional valve (), and two working connections (L, R) connected to the directional valve (), a control input () of the shut-off valve () being connected to the pump connection (P) by means of a control valve. Such a control arrangement should be operated at a high hydraulic pressure and at the same time it should be made sure that the shut-off valve is actuated only when the required high pressure is available. To this end the control valve () is a pilot operated valve, an inlet () of said control valve () being connected to the pump connection (P), said control valve () connecting said input () and said pump connection (P) in an actuated state of said control valve ().

Hydraulic control arrangement

The invention concerns a hydraulic steering () comprising a supply connection arrangement, a steering motor (), a high pressure supply (P), and a steering unit () arranged between the supply connection arrangement (S) and the steering motor (), the supply connection arrangement comprising a steering valve (), and a valve arrangement (). The task of the hydraulic steering is to improve the safety and faults detection over the state of the art. For this purpose, the steering valve () is only deflectable if the valve arrangement () is deflected.

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Soenderborg, Denmark

Morten Hoeck Petersen