Robert Boschgmbh

Bosch Rexroth Ag

Klaus Hoefling

Claus Schneider

Thorsten Beck

Johannes Wolf

Reiner Vaethjunker

Matthias Gernert

A directly-controlled hydraulic directional valve includes a housing, control piston, first and second springs, double-stroke solenoid, spring plate, adjustment device, and electronics. The piston is longitudinally displaceable in a bore in the housing, either directly or via a control sleeve. The springs are positioned in a region of an end of the piston remote from the solenoid. One end of each spring is supported on the spring plate, which is clamped between the springs and the piston. The other end of the first spring is fixed to the housing, and the other end of the second spring is fixed to the adjustment device. The first spring exerts a force on the piston in a first direction, and the second spring exerts a force on the piston in a second opposite direction, so as to bias the piston into a preferred position. The solenoid is mounted on a side of the housing, and is operable to move the piston out from the preferred position in opposite directions proportional to an electric current from the electronics, such that the piston moves to the preferred position in response to each of non-actuation of the solenoid and a fault in the electronics. The adjustment device is operable to alter a position of the other end of the second spring to adjust the preferred position of the piston.

Directly-controlled hydraulic directional valve

A valve has a valve housing which is connected to an electronics unit. The electronics unit has an electronics unit housing which has an aperture in order to establish electrical contacting with an actuator of the valve. A portion of the actuator may protrude into the aperture. Here, play is provided between the aperture and the portion of the actuator.

Valve and electric actuator housing

What is disclosed is a method for manufacturing a valve piston, as well as a valve piston, wherein flow in the fine control range is determined through control windows formed by a through opening extending through the valve body.

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Lohr, Germany

Klaus Hoefling