Fev Motorentechnik Gmbh

Fev Motorentechnik Gmbh & Co Kg

Fev Motorentechnik Gmbh & Co. Kommanitgesellschaft

Martin Dusterhoft

Gunter Lothar Gurich

Hermann Josef Laumen

Thomas Flecke

The invention related to a method for low loss periodic control of a capacitive load (C,), in particular of a piezoelectric actuator. In this method, before load control begins, a capacitor bank (C,) is charged via a voltage source (U,) until the oprating voltage of load (C,) is attained; then the load (C,) is charged from the capacitor bank (C,) via a series resonant circuit formed by a reactance coil (L,), a freewheeling diode (D,), and by the load (C,). In this method, when a load is required, the load (C,) is linked via discharge switch (S,) to the reactance soil (L,) which is itself connected via a freewheeling freewheeling diode (D,) to the capacitor bank (C,) in such a way that the load (C,) is discharged until a residual voltage (U,).

Method for low loss control of a capacitive load, in particular of a piezoelectric actuator

A hydraulic control valve includes a valve housing defining a valve chamber having first and second axially spaced valve seats of identical diameters, a control cylinder and first and second end cylinders. The valve chamber, the control cylinder and the first and second end cylinders are axially arranged in a series and form a cavity. A first pressure conduit communicates with the control cylinder, a second pressure conduit communicates with the first end cylinder, a third pressure conduit communicates with the second end cylinder; a control conduit communicates with control cylinder; and a discharge conduit communicates with the valve chamber. A plunger body is accommodated in the cavity and is composed of a valve body disposed in the valve chamber for being selectively seated in the valve seats, a control piston disposed in the control cylinder, a first support piston disposed in the first end cylinder and exposed to pressure from the second pressure conduit and a second support piston disposed in the second end cylinder and exposed to pressure from the third pressure conduit. The valve body, the control piston and the first and second support pistons constitute loosely axially serially disposed separate plunger body segments having different geometrical shapes dependent on functions thereof. A closing spring supports the second support piston and urges the valve body towards one of the valve seats.

Hydraulic plunger valve

A fuel injection valve for an internal combustion engine includes a valve block; an injection nozzle carried by the valve block and having a nozzle opening; a valve needle slidable in the injection nozzle for assuming closed and open positions to block and, respectively, to unblock the nozzle opening; a closing spring urging the valve needle into the closed position; and a pressurized fluid port in the valve block. The nozzle opening is in communication with the pressurized fluid port in the open position of the valve needle. A discharge port is defined in the valve block for carrying fluid away therefrom. An equalizing piston, which is slidably disposed in a work chamber in the valve block, is connected with the valve needle. A control plunger is movable in the valve block and has a first position and a second position. In the first position the control plunger prevents communication between the discharge port and the work chamber and maintains communication between the pressurized fluid port and the work chamber for maintaining the equalizing piston and the valve needle in the closed position. In the second position the control plunger prevents communication between the pressurized fluid port and the work chamber and maintains communication between the discharge port and the work chamber for moving the equalizing piston and the valve needle into the open position. A throttle is disposed in the discharge port for braking fluid flow from the work chamber through the discharge port.

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Aachen, Germany

Martin Dusterhoft