Robert Boschgmbh

Bosch Rexroth Ag

Reiner Kunz

Steffen Knapper

Christoph Keyl

Markus Grammer

Gerhard Keuper

Joerg Mueller

Heinrich Loedige

Soenke Jessen

Andreas Albrecht

Ingo Kallfass

Frank Rieckhof

Simon Ehmann

Heinrich LÖDIGE

Sönke Jessen

A method is for operating a valve that includes a linearly movable control slide, at least one solenoid, and a position sensor. The linearly movable control slide is preloaded by at least one spring in a direction of a zero position. The at least one solenoid is coupled to the control slide in such a way that the control slide can be moved away from the zero position by application of current to the solenoid. The position sensor is configured to measure an actual instantaneous position of the control slide. Each solenoid is assigned a current control device configured to influence a current through the relevant solenoid based on an instantaneous current control variable. The instantaneous current control variable is dependent on a quasi-periodic dither current control variable. The method also includes calculating an actual dither amplitude from the actual instantaneous position using a band-pass filter.

Method for minimizing the dither hum on a valve

A hydraulic coupling bush which is actuated in order to close or open the coupling includes a coupling housing and a bush body which displaceable therein and which has a plug space for receiving a coupling plug, a supply space for fluidic connection to an external supply channel, a low pressure space for fluidic connection to a pressure medium sink, and an interior space connected fluidically to the supply space, a supply seat valve device being provided, via the actuation of which a supply flow path can be configured between the supply space and the plug space, and a relief seat valve device being provided, via the mechanical actuation of which the interior space can be relieved of pressure toward the low pressure space, and via the hydraulic actuation of which, which is dependent on the pressure in the interior space, the pressure in the interior space can be limited.

Hydraulic coupling bush

A hydraulic valve includes a sliding control member that delimits at least one constantly adjustable diaphragm. The sliding control member is configured to be moved in the direction of a longitudinal axis. The hydraulic valve further includes a locking device with a locking member that is configured to be moved counter to the force of a first spring transversely relative to the longitudinal axis. The hydraulic valve further includes at least one catch contour in which the locking member is configured to be engaged in such a positive-locking manner that the sliding control member is releasably retained in a catch position that is associated with the respective catch contour. The position of at least one catch contour is constantly adjustable in such a manner that the free cross-sectional surface-area of the at least one diaphragm is constantly adjustable in the associated catch position.

Hydraulic valve with adjustable locking device

A hydraulic two-way valve includes a pump connection, a tank connection, and first and second working connections. The working connections are connectable to a hydraulic cylinder of an agricultural vehicle lifting mechanism. The pump connection is connectable to a hydraulic pump. In a first position, the pump connection, tank connection, and working connections are shut off. In a second position, the pump connection is connected to the first working connection and the tank connection to the second working connection. In a third position, the pump connection is connected to the second working connection and the tank connection to the first working connection. In a fourth position, the working connections are connected to the tank connection and the pump connection is shut off. In a fifth position, the tank connection is connected to the second working connection and the pump connection and first working connection are shut off.

Hydraulic two-way valve for the lifting mechanism of an agricultural vehicle

A directional control valve arrangement includes a directional control valve with a valve spool. Using the directional control valve, it is possible to control a pressure-medium connection between a pressure port, a tank connection, and at least one working connection. A blocking valve is situated in a working passage that is connected to the working connection. The pressure in the working passage can be reduced using a pressure-release unit; the pressure-medium connection between the working passage and the tank connection is blocked by the valve spool. The pressure-relief unit has an intermediate space which is formed in the pressure-medium flow path between the blocking valve and a control edge of the valve spool that blocks the working passage to the tank port, the intermediate space being provided to accommodate a compression volume of the working passage. The intermediate space can be connected to the working passage by controlling-open the blocking valve, and the connection to the tank port is blocked by the control edge of the valve spool.

Directional control valve arrangement

Disclosed is a lifting gear valve arrangement for controlling a double-action lifting gear or an add-on unit with a continuously adjustable directional control valve and with an individual pressure compensator via which a pressure medium volume flow to and from a lifting cylinder of the lifting gear can be controlled. A proportionally adjustable pressure limiting valve is provided in the pressure medium flow path between an outlet connection of the directional control valve and a working connection of the lifting gear valve arrangement, via which the pressure inside this area can be limited to a maximum value. The adjustment of the pressure limiting valve is preferably performed as a function of the operating states of the lifting gear or of the type of add-on unit.

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Sachsenheim, Germany

Reiner Kunz