Abstract: A series of method and apparatus advances in the accumulator-type fuel injector art, applicable to both intensified and unintensified accumulator injectors, which cooperate to provide major improvements in internal combustion engine fuel economy, reduction of noise, and reduction of undesirable exhaust emissions, including smoke, oxides of nitrogen and hydrocarbons. According to the invention, injector needle closure speed is increased for sharper fuel cutoff and better atomization proximate closure and needle closure bounce is minimized to minimize fuel dribble proximate closure by reducing both mass and length of the needle, which can be accomplished by a longitudinally divided needle. Hydraulic damping also damps and cushions both needle closing and needle opening.

Abstract: A method of reducing undesired premixed burning in an internal combustion engine includes lifting an injector needle of a fuel injector a constant low-lift increment from a valve seat of a valve covers orifice (VCO) nozzle having an injection hole opening into the valve seat, and preventing lifting of the needle beyond the low-lift increment for a sufficient interval of time to inject a relatively small initial fuel charge into the engine from the VCO nozzle, the injection producing a highly atomized, wide-angle spray plume with relatively low penetration. The interval terminates when lifting forces imposed on the needle overcome holding forces imposed on the needle by a stop plate which has opposed first and second surfaces exposed to an ambient fluid pressure and to a fluid vapor pressure, respectively. A subsequent step includes lifting the needle to a higher lift position to inject a main fuel charge into the engine, the main fuel charge being injected as a relatively narrow jet having high penetration.

Abstract: A series of method and apparatus advances in the accumulator-type fuel injector art, applicable to both intensified and unintensified accumulator injectors, which cooperate to provide major improvements in internal combustion engine fuel economy, reduction of noise, and reduction of undesirable exhaust emissions, including smoke, oxides of nitrogen and hydrocarbons. According to the invention, injector needle closure speed is increased for sharper fuel cutoff and better atomization proximate closure, and needle closure bounce is minimized to minimize fuel dribble proximate closure by reducing both mass and length of the needle, which can be accomplished by a longitudinally divided needle. Hydraulic damping also damps and cushions both needle closing and needle opening.

Abstract: A series of method and apparatus advances in the accumulator-type fuel injector art, applicable to both intensified and unintensified accumulator injectors, which cooperate to provide major improvements in internal combustion engine fuel economy, reduction of noise, and reduction of undesirable exhaust emissions, including smoke, oxides of nitrogen and hydrocarbons. According to the invention, injector needle closure speed is increased for sharper fuel cutoff and better atomization proximate closure, and needle closure bounce is minimized to minimize fuel dribble proximate closure by reducing both mass and length of the needle, which can be accomplished by a longitudinally divided needle. Hydraulic damping also damps and cushions both needle closing and needle opening.