SUPERCHARGED INTERNAL COMBUSTION ENGINE

摘要

A blower scavenging arrangement for an internal combustion engine (5) including a blower (10) for supplying air to the engine (5), a bypass valve (15) for regulating a bypass airflow from the outlet side of the blower (10) to the inlet side thereof to thereby provide a variable rate of bypass airflow, and an ambient air valve (14) for regulating the flow rate of ambient air to the blower (10), wherein said regulation by said bypass valve (15) and said ambient air valve (14) thereby controls the pressure of the intake air supply to the blower (10), the bypass valve (15) and the ambient air valve (14) being independently controlled. These two valves together ensure that the airflow to the engine (5) can be controlled such that a suitable amount of air is delivered at any load point over the entire operating regime of the engine (5). Furthermore, the two valves together ensure that effective exhaust gas recirculation (EGR) from the engine exhaust system (6) back into the air intake system (11) can be achieved throughout the operating range of the engine (5) and particularly at idle and low load conditions.