Abstract: Fuel injection apparatus for diesel engines includes an injection pump connected to an injector nozzle through a control device constituted by two calibrated and opposed non-return valves arranged to keep a residual pressure of a predetermined magnitude in the fuel supply passage to the injector between each injection cycle and the next. The two non-return valves are located downstream of the output of the pump and are preferably inserted in a body fixed to or forming part of the injector, or forming part of the delivery union of the pump.

Abstract: A fuel injection pump for diesel engines, in which the pressure chamber of each cylinder (10) is defined on its side opposite the piston (16) by a slide valve (38) movable in a direction opposite the piston against the action of resilient biasing means (52). The slide valve is sensitive to the supply pressure of the fuel and controls communication between the pressure chamber and the fuel delivery passage (44, 46). The supply pressure is controlled by external modulating means which varies the equilibrium position of the slide valve. The slide valve allows the initial alteration of the effective delivery, and hence the effective injection advance, in dependence on the running conditions/load of the engine.

Abstract: A constant-pressure delivery valve for fuel injection pumps for diesel engines includes a conical-surface obturator to which is fixed a body forming an axial chamber containing a calibrated one-way valve with a ball obturator. The ball obturator is located on that side of the chamber facing the conical-surface obturator and controls communication between radial and axial fuel return passages formed beneath the bottom of the chamber.