Robert Boschgmbh

Stephan Jonas

Guenther Hohl

Martin Oehler

Hans-Juergen Herderich

Norbert Mittwollen

Norbert Mittelwollen

[The aim is to] A solenoid valve which achieves a setting of a reduced flow area which is active after a closed position of the valve is disclosed. The solenoid valve has a seat valve in a valve chamber. A magnet armature for actuating the seat valve is provided on its end face remote from the seat valve with an axially expandable hollow part whose interior, acting as a control chamber, is connected to a valve sub chamber through a pressure fluid channel. A [D]dynamic pressure is generated in the partly open position of the seat valve in the valve subchamber and is capable through expansion of the hollow part in the control chamber of causing a force which acts on the magnet armature against the force of a resetting spring and on the basis of which the seat valve maintains its partly open position. The valve can be used in slip-controlled hydraulic brake systems of motor vehicles.

Electromagnetically actuated valve for slip-controlled hydraulic brake

An electromagnetically actuated valve which achieves the setting of a reduced cross section of flow following a closed position of the valve. The solenoid valve has a seat valve which is surrounded by a sleeve which is secured pressure-tightly on a valve body. In the closed position of the seat valve, a tappet engages in the sleeve, forming a small radial gap. From the interior of the sleeve, a first pressure-medium passage leads to an end face of a magnet armature, said end face being remote from the seat valve. Outside the sleeve, a second pressure-medium passage leads to that end face of the magnet armature which is close to the seat valve. In the case of a pressure drop between the pressure-medium inlet and the pressure-medium outlet of the solenoid valve, the seat valve can assume a partially open position following a closed position of said valve since, due to the gap, which acts as a restriction, a pressure disequilibrium arises at the magnet armature and valve opening forces are compensated. The valve can be employed in slip-controlled hydraulic brake systems of motor vehicles.

A valve having a magnetic armature, which is moved longitudinally in a valve dome; a valve tappet of this armature carries a closing member of a seat valve, which is open when in the rest position. The seat valve is disposed in a valve chamber, from which two pressure fluid conduits lead to face ends of the magnetic armature, which is sealed on its circumference side. When the seat valve is partially open, a pressure is produced in a partial valve chamber by means of a shaping of the valve seat as a hollow cone and of the closing member as a flattened end ball. In the control chamber remote from the closing member, this pressure leads to a movement of the magnetic armature against the tension of a restoring spring, which results in a reduction of the through flow cross section of the seat valve. The valve is particularly useful in slip-controlled hydraulic brake systems of motor vehicles.

Growing community of inventors

Gerlingen, Germany

Stephan Jonas