Six-Stroke Engine Power Density Matching System and Method

摘要

An engine combustion cylinder is fluidly connectable to an intake system through an intake valve and to an exhaust system through an exhaust valve. A valve activation system is to activate the intake valve and the exhaust valve. The valve activation system is responsive to a controller providing command signals to the valve activation system such that, when the engine operates in a six-stroke combustion cycle, the intake valve is opened during a recompression stroke to allow a portion of the products from the first combustion stroke to exit the combustion cylinder and enter into the intake system. This may be done to match the power densities of the first and second power strokes of the piston.

主权项

1. An internal combustion engine system operating on a six-stroke cycle comprising:
an internal combustion engine including a cylinder, a piston reciprocally disposed in the cylinder to move between a top dead center position and a bottom dead center position, an intake system communicating with the cylinder to introduce charge gas into the cylinder through an intake valve, an exhaust system communicating with the cylinder to direct exhaust gasses from the cylinder through an exhaust valve and a fuel injector disposed to inject fuel into the cylinder, wherein the engine operates on a combustion cycle that includes an intake stroke, during which air is admitted into the combustion cylinder, a compression stroke, during which the air in the combustion cylinder is compressed and fuel is added, a first power stroke, a second compression stroke, during which products from the first combustion stroke are compressed in the combustion cylinder, a second power stroke, and an exhaust stroke; and a controller being configured and operable to determine a desired power density for a power stroke of the piston in the cylinder based on one or more operating parameters of the internal combustion engine, control opening of the intake valve and operation of the fuel injector to provide a desired fuel and charge gas mixture for producing the desired power density during a first power stroke of the piston in the cylinder, and control timing of at least one of the intake and exhaust valves during the second compression stroke of the piston in the cylinder to produce the desired power density during the second power stroke.