Method of operating an automotive type internal combustion engine

Claim 1

A method of operating at part load engine operating conditions an automotive type internal combustion engine having an intake manifold with intake and exhaust ports and intake and exhaust valves movable, respectively, therein between open and closed positions, throttling means upstream of and associated with the intake port and variably movable between throttling and unthrottling positions to control flow through the intake port, and phase shifting means for varying the opening and closing of the valves from a fixed timing schedule as a function of operating conditions to obtain efficient operation and control of emissions, comprising the steps of: first, inserting a one-way valve adjacent the intake port upstream of the intake valve operable to prevent flow of engine cylinder contents from the cylinder past the port while permitting intake flow of charge and gases into the cylinder in the opposite direction; secondly, opening the engine exhaust valve during the engine expansion stroke at cylinder pressures higher than manifold pressure; thirdly, with throttled control of the intake port only enough to maintain stable engine operation and to minimize engine pumping losses, and shortly after opening of the exhaust valve, opening the engine intake valve near piston bottom dead center position (BDC) between the engine expansion and exhaust strokes thereby effecting closing of the one-way valve under the influence of high cylinder pressure to block the intake flow of exhaust gases towards the intake port; fourthly, maintaining the exhaust valve open later than normal into the initial portion of the engine intake stroke to a point where the motion of the piston during the intake stroke has permitted inflow of exhaust gases through the exhaust valve for exhaust gas recirculation (EGR) for minimum emission control; fifthly, closing the exhaust valve shortly thereafter at a point when only that quantity of exhaust gases are influxed to provide the minimum EGR emission control that is necessary; and finally, closing the intake valve early in the engine intake stroke after exhaust valve closure to minimize/eliminate engine pumping losses while providing the desired engine power.

Claim 2

A method of operating at part load engine operating conditions an automotive type internal combustion engine having an intake manifold with intake and exhaust ports and intake and exhaust valves movable, respectively, therein between open and closed positions, throttling means upstream of and associated with the intake port and variably movable between throttling and unthrottling positions to control flow through the intake port, and phase shifting means for varying the opening and closing of the valves from a fixed timing schedule as a function of operating conditions to obtain efficient operation and control of emissions, comprising the steps of: first, inserting a one-way valve adjacent the intake port upstream of the intake valve operable to prevent flow of engine cylinder contents from the cylinder past the port while permitting intake flow of charge and gases into the cylinder in the opposite direction; secondly, opening the engine exhaust valve during the engine expansion stroke at cylinder pressures higher than manifold pressure; thirdly, with throttled control of the intake port only enough to maintain stable engine operation and to minimize engine pumping losses, and shortly after opening of the exhaust valve, opening the engine intake valve near piston bottom dead center position (BDC) between the engine expansion and exhaust strokes thereby effecting closing of the one-way valve under the influence of high cylinder pressure to block the intake flow of exhaust gases towards the intake port; fourthly, maintaining the exhaust valve open later than normal into the initial portion of the engine intake stroke to a point where the motion of the piston during the intake stroke has permitted inflow of exhaust gases through the exhaust valve for exhaust gas recirculation (EGR) for minimum emission control; fifthly, closing the exhaust valve shortly thereafter at a point when only that quantity of exhaust gases are influxed to provide the minimum EGR emission control that is necessary; and finally, closing the intake valve early in the engine intake stroke after exhaust valve closure to minimize/eliminate engine pumping losses while providing the desired engine power.

Claim 5

A method of operating at idle speed condition an automotive type internal combustion engine having an intake manifold with intake and exhaust ports and intake and exhaust valves movable, respectively, therein between open and closed positions, throttling means upstream of and associated with the intake port and variably movable between throttling and unthrottling positions to control flow through the intake port, and phase shifting means for varying the opening and closing of the valves from a fixed timing schedule as a function of operating conditions to obtain efficient operation and control of emissions, comprising the steps of: first, inserting a one-way valve adjacent the intake port upstream of the intake valve operable to prevent flow of engine cylinder contents from the cylinder past the port while permitting intake flow of charge and gases into the cylinder in the opposition direction; secondly, opening the engine exhaust valve during the engine expansion stroke at cylinder pressures higher than manifold pressure; thirdly, with essentially unthrottled control of the intake port to minimize engine pumping losses, and shortly after opening of the exhaust valve, opening the engine intake valve thereby effecting closing of the one-way valve under the influence of high cylinder pressure to block the flow of exhaust gases towards the intake port; fourthly, maintaining the exhaust valve open allowing the piston to draw in exhaust gases from the exhaust manifold for exhaust gas recirculation (EGR) for minimum emission control; fifthly, closing the exhaust valve shortly thereafter at a point permitting only that quantity of exhaust gases to be influxed to provide the minimum EGR emission control that is necessary; and finally, closing the intake valve early in the engine intake stroke after exhaust valve closure to provide only that amount of intake charge necessary to overcome engine friction and sustain engine operation while minimizing/eliminating engine pumping losses.

Claim 6

A method of operating at idle speed condition an automotive type internal combustion engine having an intake manifold with intake and exhaust ports and intake and exhaust valves movable, respectively, therein between open and closed positions, throttling means upstream of and associated with the intake port and variably movable between throttling and unthrottling positions to control flow through the intake port, and phase shifting means for varying the opening and closing of the valves from a fixed timing schedule as a function of operating conditions to obtain efficient operation and control of emissions, comprising the steps of: first, inserting a one-way valve adjacent the intake port upstream of the intake valve operable to prevent flow of engine cylinder contents from the cylinder past the port while permitting intake flow of charge and gases into the cylinder in the opposition direction; secondly, opening the engine exhaust valve during the engine expansion stroke at cylinder pressures higher than manifold pressure; thirdly, with essentially unthrottled control of the intake port to minimize engine pumping losses, and shortly after opening of the exhaust valve, opening the engine intake valve thereby effecting closing of the one-way valve under the influence of high cylinder pressure to block the flow of exhaust gases towards the intake port; fourthly, maintaining the exhaust valve open allowing the piston to draw in exhaust gases from the exhaust manifold for exhaust gas recirculation (EGR) for minimum emission control; fifthly, closing the exhaust valve shortly thereafter at a point permitting only that quantity of exhaust gases to be influxed to provide the minimum EGR emission control that is necessary; and finally, closing the intake valve early in the engine intake stroke after exhaust valve closure to provide only that amount of intake charge necessary to overcome engine friction and sustain engine operation while minimizing/eliminating engine pumping losses.

Claim 11

A method as in claims 4 or 8, wherein the exhaust valve closes at a point near piston top dead center position between the engine exhaust and intake strokes.