Abstract: A method for controlling direct fuel injection into an engine is detailed. The method comprises determining a quantity of fuel to inject into a combustion chamber during a combustion cycle, and, executing three fuel injection events during the combustion cycle. The first fuel injection event is initiated during a compression stroke immediately before top-dead-center point of piston travel. A first dwell time is substantially equal to a second dwell time. Quantities of fuel injected during each of the three fuel injection events are substantially equal. An aspect of the invention includes the first and second dwell times determined based upon emissions and engine thermal efficiency. The invention facilitates improved engine-out emissions, without substantial changes in engine or aftertreatment hardware.

Abstract: A method for controlling fuel injection into a direct injection, compression-ignition internal combustion engine is provided. The engine preferably comprises a diffusion-combustion engine equipped with a fuel-injection system comprising a high-pressure fuel system and a plurality of fuel injectors each adapted to inject fuel directly into a combustion chamber of the engine and a controller. The controller is adapted to monitor engine operation and an operator torque request, and determine a quantity of fuel to inject into one of the combustion chambers during a combustion cycle. Each fuel injector is actuated to selectively execute one of one, two, and three fuel injection events to deliver the determined quantity of fuel to the combustion chamber during the combustion cycle.

Abstract: A method for controlling direct fuel injection into an engine is detailed. The method comprises determining a quantity of fuel to inject into a combustion chamber during a combustion cycle, and, executing three fuel injection events during the combustion cycle. The first fuel injection event is initiated during a compression stroke immediately before top-dead-center point of piston travel. A first dwell time is substantially equal to a second dwell time. Quantities of fuel injected during each of the three fuel injection events are substantially equal. An aspect of the invention includes the first and second dwell times determined based upon emissions and engine thermal efficiency. The invention facilitates improved engine-out emissions, without substantial changes in engine or aftertreatment hardware.

Abstract: High conversion efficiencies for methane, other unburned hydrocarbons, carbon monoxide and nitrogen oxides can be obtained from a natural gas or methane fueled engine by operating the engine with an air-fuel ratio within a range that includes the stoichiometric air-fuel ratio and extends to the fuel-rich side and by employing in combination with the engine a platinum or platinum and palladium noble metal catalyst for treatment of the engine exhaust gases.

Abstract: A late injection direct injection stratified charge spark ignition engine is provided with a catalytic grid disposed in the path of injected fuel spray and downstream of the point of spark ignition to assist the completion of combustion of previously ignited fuel spray as well as to ignite and cause the combustion of previously unignited fuel elements passing therethrough. Improved combustion and reduced hydrocarbons emissions are anticipated.

Abstract: The exhaust of unburned hydrocarbons from an internal combustion engine is reduced by selective venting of unburned air-fuel mixture trapped in the piston-cylinder crevice volume in advance of each engine exhaust stroke. Exemplary venting means disclosed include (1) a bypass channel in the cylinder wall which bypasses the piston rings and connects the crevice volume with the engine crankcase in the lower portions of the piston stroke and (2) a cylinder pressure actuated valve controlled bypass passage in the piston which accomplishes a similar function. Location of the bypass channel or passage near to the exhaust valve permits the selective retention of unburned hydrocarbon containing mixture distant from the exhaust valve and thus unlikely to be discharged in the exhaust process. Bypassed mixture is recycled from the crankcase to the inlet manifold with the engine blowby gases for combustion in the cylinders.

Abstract: Peripheral areas of the combustion chambers of an internal combustion engine are provided with perforated walls bordering external collection volumes for receiving wall quench combustibles forced through the perforations from the combustion chambers. The combustibles are recirculated to the engine induction system through passages connecting with the collection volumes, valves being provided to time the flow to take place in portions of the expansion and exhaust steps of the engine cycle which maximize the collection of quench layer combustibles while avoiding excessive cylinder pressure and efficiency losses.

Abstract: A staged internal combustion engine is provided with means for controlling temperature of the interstage gases within predetermined ranges appropriate for the varying operating conditions of the engine. The temperature control is responsive to significant engine conditions such as interstage gas temperature, engine speed and inlet manifold pressure to supply temperature controlling fluids to the interstage gases. The temperature controlling fluids include vaporizable liquids, such as water, which are added to limit maximum temperatures of the interstage gases and combustion supporting gases, such as air, which react with excess fuel in the interstage gases to quickly reach and maintain minimum temperatures.

Abstract: In an emission control system having an air pump for delivering air to the exhaust system of an internal combustion engine, a valve controls the air pump discharge pressure in a fixed relationship to exhaust pressure by diverting a portion of the air pump discharge air flow. As a result, the flow of air from the pump to the exhaust system is maintained as a constant proportion of the engine air flow.