Stratified Charge Engine with Turbocharger

摘要

In an embodiment, a method for turbocharging a stratified charge engine includes flowing, in a turbocharged mode, exhaust gas from the engine into a turbocharger based on the engine having a load greater than a threshold load and the engine operating in a first range of engine speeds, the threshold load comprising a peak load for engine operation in a naturally-aspirated mode using a lean air-fuel mixture and providing, by the turbocharger while in the turbocharged mode, an increased amount of air to a combustion chamber in the engine based on the turbocharger receiving the exhaust gas. The method also includes restricting flow, in the naturally-aspirated mode, of the exhaust gas into the turbocharger based on at least one of: the engine having a load less than the threshold load or the engine operating in a second range of engine speeds, the second range being greater than the first range.

主权项

1. A stratified charge engine system comprising:
a combustion chamber in a cylinder head of an engine; an exhaust gas conduit in fluid communication with the combustion chamber; a turbocharger in fluid communication with the combustion chamber; a flow control device, wherein a position of the flow control device controls flow of exhaust gas from the combustion chamber to the turbocharger and to the exhaust gas conduit; and a controller coupled to the flow control device, the controller having a first mode that causes the flow control device to direct flow of the exhaust gas to the turbocharger based on a load of the engine being greater than a threshold load and the stratified charge engine operating in a first range of engine speeds, the threshold load comprising a peak load for engine operation in a naturally-aspirated mode using a lean air-fuel mixture, and a second mode that causes the flow control device to direct flow of the exhaust gas to the exhaust gas conduit based on one of the load of the engine being less than the threshold load, or the engine operating in a second range of engine speeds greater than the first range of engine speeds, wherein the turbocharger provides an increased amount of air to the combustion chamber for an increased fuel intake to maintain a lean air-fuel mixture above the threshold load when operating in the first range of engine speeds.