摘要:
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.
摘要:
A control (30) for controlling a variable valve actuation mechanism (26) of an internal combustion engine (10) to regenerate a particulate filter (35) in the exhaust system (25) of the engine. The control comprises an operating program (50, 50A) for regenerating the particulate filter while the engine is running under its owns power by causing the variable valve actuation mechanism to change the timing of engine cylinder valves during an engine operating cycle, and as a result, elevate the temperature of flow through the exhaust system to a temperature that is effective to combust particles trapped by the filter.
摘要:
A turbocharger (32) creates intake manifold boost for a diesel engine (10). At times, exhaust valve opening is increasingly retarded in relation to the engine operating cycle to cause the turbocharger to increase boost, engine fueling is also increased in relation to the increased boost, and in response to any incipient surging of the compressor resulting from such increasingly retarded exhaust valve opening and such increased engine fueling, compressed charge air is bled from the intake manifold to counter the incipient surging and thereby avoid any significant turbocharger surge.
摘要:
A control (30) embodies an operating strategy (50) to facilitate engine cranking and starting via control of timing of cylinder intake (18) and exhaust (24) valve opening using a variable valve actuation mechanism (26). Prior to fueling any cylinder (16), the engine (10) is cranked while the variable valve actuation mechanism causes pistons (32) to operate at an initial effective compression ratio for initial cranking that is less than an effective compression ratio for running when the engine is eventually fueled and runs under its own power. Thereafter, and still before fueling, they are caused to operate at an increased effective compression ratio, and still thereafter, a portion of their charges are drawn from the exhaust system (22). As the engine warms up, valve timing is adjusted.
摘要:
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.
摘要:
An internal combustion engine (10) has an intake system (12) that includes a turbocharger (32). An engine control (30) processes data for controlling the opening of the exhaust valves (24) and for controlling fueling of the engine in relation to the engine operating cycle. In response to initiation of engine acceleration, the control increasingly retards exhaust valve opening in relation to the engine operating cycle to cause the turbocharger to increase pressure in the intake manifold (14) and increases engine fueling in relation to the increased pressure in the intake manifold.
摘要:
A turbocharger (32) creates intake manifold boost for a diesel engine (10) that has a variable valve actuation mechanism. At times, exhaust valve opening (EVO) is increasingly retarded in relation to the engine operating cycle (56) to cause the turbocharger to increase boost, engine fueling is also increased in relation to the increased boost (58), and in response to any incipient surging of the compressor resulting from such increasingly retarded exhaust valve opening and such increased engine fueling, compressed charge air is bled from the intake manifold through the combustion chambers to the exhaust system (62) to counter the incipient surging and thereby avoid any significant turbocharger surge. The bleeding is accomplished by keeping the exhaust valves (24) slightly open beyond the time that they would otherwise close.
摘要:
A flow controller assembly for use with a hydraulically-actuated, electrically-controlled fuel injector, includes a flow controller fluidly disposable intermediate an injector control valve assembly and an injector intensifier assembly for controlling flow of actuating fluid to and from the intensifier assembly to effect rate shaping of an injectable quantity of fuel and to effect a reduction of noise generated by the stopping of return motion of an intensifier piston. A fuel injector and a method of controlling an intensifier piston are also included.
摘要:
A combustion chamber assembly for use in a diesel engine includes a combustion chamber being defined in a crown of a piston, the piston having a central axis, the combustion chamber having a center portion being elevated relative to a bottom plane of the combustion chamber. The center portion is defined in part by a portion of a sphere, the sphere having a radius, the origin of the radius lying on the combustion chamber central axis. The combustion chamber further has an outer margin, the outer margin being defined in part by a portion of a sphere, the sphere having a radius, the origin of the radius lying on the combustion chamber central axis and being greater than the center portion radius. The spherical center portion and the spherical outer margin are connected by an annular surface. And, the combustion chamber has a plurality of curved surfaces having smooth tangential transitions between adjacent smooth surfaces, the smooth surfaces including the spherical center portion and the spherical outer margin in combination with the annular surface. A piston incorporating the aforementioned combustion chamber and a method of forming the combustion chamber are further included.
摘要:
Engine systems and methods for accomplishing regeneration of a NOx adsorber (28) using in-cylinder post-injection in a way that creates a lean-rich transition (FIG. 3) for regenerating the NOx adsorber while attenuating engine torque output fluctuations during the transition without the necessity of using torque sensing to attenuate the fluctuations.