Abstract: An apparatus for variably controlling the fuel flow characteristics of a hydraulically-actuated injector during an injection cycle. The apparatus includes variable control of actuating fluid pressure and a spill control apparatus associated with the plunger and barrel assembly of the injector. The apparatus can control the initial rate of fuel injection and also provide continuous or split injection throughout the load and speed range of an engine. Performance is controlled by the geometry of the spill control apparatus along with the variably controlled pressure of the actuating fluid supplied to the injector. The apparatus helps reduce engine noise and emissions.

Abstract: An improved actuating fluid inlet manifold for a plurality of hydraulically-actuated fuel injectors. The manifold includes fluid dynamic tuning apparatus for controlling the flow of relatively high pressure actuating fluid between the common rail passage of the manifold and the injectors. The fluid dynamic tuning apparatus includes a predetermined flow restriction defined in each of the rail branch passages of the manifold. Advantages of the fluid dynamic tuning apparatus include improved injector performance and/or a reduction in structural stresses of various engine components.