Abstract: A method of operating an internal combustion engine is provided. An in-cylinder pressure within a cylinder of the engine is determined. A fuel injection pressure from a fuel injector disposed within the cylinder is determined. A ratio of the in-cylinder pressure within the cylinder and the fuel injection pressure is compared to a stored threshold value. The fuel injection pressure is adjusted based upon the comparison of the ratio of the in-cylinder pressure within the cylinder and the fuel injection pressure to the stored threshold value.

Abstract: A method of operating an internal combustion engine is provided. An air/fuel ratio of the internal combustion engine is determined. At least one of a fuel injection quantity and an intake air flow is adjusted to provide an air/fuel ratio between about 15 and about 18. A compression ratio within a cylinder of the engine is determined. Droplet size of fuel provided by a fuel injector is adjusted based upon the compression ratio determined within the cylinder of the engine.

Abstract: A system and method for hydrogen rich exhaust gas recirculation are provided. The system includes the addition of a supplemental injector injecting additional natural gas beyond the stoichiometric point into one of the engine cylinders. After combustion, the exhaust of the cylinder remains high in hydrogen. The exhaust is then routed through a hydrogen rich exhaust path to an exhaust gas recirculation mixer where is it mixed with natural gas and exhaust gas from the other cylinders. The resultant mixture is then routed to all of the cylinders of the engine for improved combustion due to the additional hydrogen.

Abstract: An exhaust gas recirculation venturi pump for drawing an exhaust gas from an exhaust manifold of an internal combustion engine through an exhaust gas recirculation system. The exhaust gas recirculation venturi pump includes a first passageway that at least in part is configured to provide a venturi effect using the flow of an air/fuel mixture through the exhaust gas recirculation venturi pump. At least the decrease in pressure of the air/fuel mixture created by the venturi effect may draw an exhaust gas from the exhaust manifold into the exhaust gas recirculation venturi pump. Moreover, the suction provided by the venturi effect may pull the exhaust gas through an exhaust gas recirculation system, even when the exhaust gas pressure at the exhaust gas manifold is equal to or greater than the pressure of the intake charge at the intake manifold.

Abstract: A method of operating an internal combustion engine is provided. An air/fuel ratio of the internal combustion engine is determined. At least one of a fuel injection quantity and an intake air flow is adjusted to provide an air/fuel ratio between about 15 and about 18. A compression ratio within a cylinder of the engine is determined. Droplet size of fuel provided by a fuel injector is adjusted based upon the compression ratio determined within the cylinder of the engine.

Abstract: A method of operating an internal combustion engine is provided. An in-cylinder pressure within a cylinder of the engine is determined. A fuel injection pressure from a fuel injector disposed within the cylinder is determined. A ratio of the in-cylinder pressure within the cylinder and the fuel injection pressure is compared to a stored threshold value. The fuel injection pressure is adjusted based upon the comparison of the ratio of the in-cylinder pressure within the cylinder and the fuel injection pressure to the stored threshold value.

Abstract: A method of controlling the compression ratio in an engine (10) having at least one cylinder (12) with a piston (14) includes providing an air control valve (16) in fluid communication with the cylinder, where the air control valve is in fluid communication with a reservoir (52). The method also includes opening the air control valve (16) in a compression stroke before the piston (14) reaches top dead center, and closing the air control valve (16) when the piston reaches top dead center.

Abstract: A check valve body (44) is disposed within the interior of a main body (32) of a fuel injector (30) and contains a continuous sealing ridge for sealing a perimeter of a cavity (124) between the proximal end face of the check valve body and the distal end face of an intensifier cartridge body (46). A spring cage (42) has a proximal end face disposed within the interior of the main body. An entry check (154) is disposed in an entry through-passage (132), and an exit check (156) is disposed in an exit through-passage (130). A continuous sealing ridge seals a perimeter of an exit cavity (140), and a discontinuous sealing ridge seals a portion of a perimeter of an entry cavity (144). The sealing ridges are asymmetric about a longitudinal axis AX.

Abstract: A unit fuel injector (30) has a nozzle (36) providing axial guidance of a needle (72) at points proximal and distal to a needle feed cavity (81). The needle has a multi-lobular formation (200) providing distal guidance of the needle while allowing fuel from the needle feed cavity to flow past for injection from orifices (86) when the needle is unseated from a seat on a tapering surface (82). Fuel is delivered to the needle feed cavity through a slant passage (85) in the nozzle non-parallel to a longitudinal axis (AX) along which the needle is displaced. The orifices are arranged in a hemispherically contoured surface (83) distal to the seat and centered on a point on the longitudinal axis. The orifices have circular transverse cross sections. The axis of each orifice extends radially of the point on the longitudinal axis at an oblique angle to the longitudinal axis.

Abstract: A fuel injector for injecting fuel into a cylinder of an internal combustion engine includes an injector body and a needle valve. A feed passage (408) fluidly connects a needle chamber (402) with a source of high pressure fuel. The needle chamber (402) is formed in a needle housing (400) and has a centerline (X) extending along its length. The needle valve is located in the needle chamber (402). A collection cavity (410) is formed in the needle housing (400) and in fluid communication with the needle chamber (402). The collection cavity (410) is positioned between the needle chamber (402) and the feed passage (408). The collection cavity (410) is advantageously substantially symmetrical about a plane that is perpendicular to the centerline (X) of the needle chamber (402).

Abstract: An engine control system (28) causes combustion chambers (20) to be fueled during an engine cycle by a main injection (38) ending no later than substantially at the TDC between compression and expansion strokes of the cycle without any further injection of fuel during the expansion stroke, and then during the exhaust stroke of the cycle, by a post-injection (40) for elevating the temperature of the gases into a regeneration temperature range for regenerating a diesel particulate filter (36).

Abstract: An apparatus includes a tangential mixer (200) having an air inlet (207) and a mixture outlet (209). A bore (205) has a bore centerline (213) and a bore perimeter (201). At least one gas inlet (211) has an inlet centerline (215) oriented tangentially to the bore perimeter (201). The inlet centerline (215) is within a cone (300). The cone (300) has a vertex point “A” on the inlet centerline (215).

Abstract: A control (30) for controlling a variable valve actuation mechanism (26) of an internal combustion engine (10) to regenerate a NOx adsorber catalyst (35) in the exhaust system (22) of the engine. The control comprises an operating program (50) for regenerating the catalyst while the engine is running under its own power by causing the variable valve actuation mechanism to change the timing of operation of the intake valves (18) so as to transition the fuel-air ratio of mixture that is being combusted in the cylinders (16) from a relatively leaner mixture to a mixture that sufficiently richer than stoichiometric to effectively regenerate the catalyst.

Abstract: A control (30) for controlling a variable valve actuation mechanism (26) of an internal combustion engine (10) to regenerate a NOx adsorber catalyst (35) in the exhaust system (22) of the engine. The control comprises an operating program (50) for regenerating the catalyst while the engine is running under its own power by causing the variable valve actuation mechanism to change the timing of operation of the intake valves (18) so as to transition the fuel-air ratio of mixture that is being combusted in the cylinders (16) from a relatively leaner mixture to a mixture that sufficiently richer than stoichiometric to effectively regenerate the catalyst.

Abstract: A method and apparatus for injecting fuel into a diesel engine combustion chamber is provided wherein a pre-pilot injection is injected sufficiently prior to critical mass conditions being achievable to permit vaporization and formation of a substantially homogenous mixture before a critical mass exists. Preferably, a pilot injection is injected after the pre-pilot injection but at or before a point wherein a critical mass based on the pre-pilot quantity. This will result in a reduced heat release rate will result in a slower, smoother and more controlled build up of pressure in a combustion chamber and thereby advantageously reduce combustion noise.