Abstract: A fuel injection system includes a plurality of mechanical unit pumps, each of which has a pump outlet. A pressure-intensifying hydraulically-actuated electronically-controlled fuel injector is provided for each of the plurality of mechanical unit pumps. Each of the fuel injectors has a direct control needle valve and an injector body that defines an actuation fluid inlet, a fuel inlet, an actuation fluid cavity and a fuel pressurization chamber. Each fuel injector also includes a moveable pumping element with a large hydraulic surface exposed to fluid pressure in the actuation fluid cavity, and a small hydraulic surface exposed to fluid pressure in the fuel pressurization chamber. An actuation fluid supply line is provided for each of the plurality of mechanical unit pumps. Each supply line has one end connected to one pump outlet and an other end connected to one actuation fluid inlet of an individual fuel injector.

Abstract: A fuel injection system includes a plurality of mechanical unit pumps, each of which has a pump outlet. A pressure-intensifying hydraulically-actuated electronically-controlled fuel injector is provided for each of the plurality of mechanical unit pumps. Each of the fuel injectors has a direct control needle valve and an injector body that defines an actuation fluid inlet, a fuel inlet, an actuation fluid cavity and a fuel pressurization chamber. Each fuel injector also includes a moveable pumping element with a large hydraulic surface exposed to fluid pressure in the actuation fluid cavity, and a small hydraulic surface exposed to fluid pressure in the fuel pressurization chamber. An actuation fluid supply line is provided for each of the plurality of mechanical unit pumps. Each supply line has one end connected to one pump outlet and an other end connected to one actuation fluid inlet of an individual fuel injector.

Abstract: A fuel injector comprises an injector body which defines a nozzle chamber that is separated from a plurality of outlet orifices by a conical valve seat. An outwardly opening valve member, which is at least partially positioned in the injector body, includes a closing hydraulic surface exposed to fluid pressure outside the injector body. The valve member is movable between a closed position, in which the conical valve seat is closed, and an open position.