Controllable fuel injection valve for an internal-combustion engine

Abstract

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.