METHOD AND APPARATUS FOR COMBINING EXHAUST GAS RECIRCULATIONAND ENGINE EXHAUST BRAKING USING SINGLE VALVE ACTUATION

摘要

A system for accomplishing engine exhaust braking and exhaust gas recirculation for an engine having an exhaust manifold and a plurality of exhaust valves per cylinder during a four stroke engine cycle is provided. The system includes an actuation device operable to provide valve actuation of a single exhaust valve for an exhaust braking event and an exhaust gas recirculation event. The exhaust valve is not completely closed during the exhaust braking event and the exhaust gas recirculation event. The exhaust braking event includes actuating a single exhaust valve beginning during a second half of a compression stroke and a first half of an expansion stroke, and closing the exhaust valve beginning during a second half of an exhaust stroke. The exhaust gas recirculation event includes reactuating the exhaust valve beginning during a first half of an intake stroke, and closing the exhaust valve beginning during a second half of the intake stroke. Since a single exhaust valve is actuated during the exhaust braking and exhaust gas recirculation events, the overall performance of the vehicle is increased.