Abstract: An intake device of an engine having cylinders is provided. The intake device includes a cylinder head formed with two intake ports per cylinder, and a forced induction system. One of the two intake ports is designed to have a smaller passage cross-sectional area at a throat portion thereof than that of the other intake port, and to cause a strength of a tumble flow strength of intake air formed within a combustion chamber to be stronger when a flow of the intake air into the combustion chamber is assumed to be caused only from the one of the two intake ports, than only from the other intake port. A tumble ratio of the intake air flow within the combustion chamber is a predetermined value or greater when the intake air is forcibly induced and flows into the combustion chamber from the two intake ports.

Abstract: An intake device of an engine having cylinders is provided. The intake device includes a cylinder head formed with two intake ports per cylinder, and a forced induction system. One of the two intake ports is designed to have a smaller passage cross-sectional area at a throat portion thereof than that of the other intake port, and to cause a strength of a tumble flow strength of intake air formed within a combustion chamber to be stronger when a flow of the intake air into the combustion chamber is assumed to be caused only from the one of the two intake ports, than only from the other intake port. A tumble ratio of the intake air flow within the combustion chamber is a predetermined value or greater when the intake air is forcibly induced and flows into the combustion chamber from the two intake ports.

Abstract: Disclosed is an exhaust gas recirculation system for an engine (1), wherein at least a downstream sub-region of a region of an exhaust passage (33) upstream of a turbine wheel (52) is divided into two sub-passages (R1, R2) by a partition wall (20a, 30a) extending along an exhaust gas flow direction. A high-speed sub-passage (R2) in the two sub-passages (R1, R2) is equipped with an openable-closable exhaust variable valve (23). The exhaust variable valve (23) is configured to be controlled to open the high-speed sub-passage (R2) when an engine speed is equal to or greater than a reference speed, and close the high-speed sub-passage (R2) when the engine speed is less than the reference speed. An inlet (60a) of an EGR passage (60) on the side of the exhaust passage (33) is opened to the high-speed sub-passage (R2) at a position downstream of the exhaust variable valve (23).

Abstract: Disclosed is an exhaust gas recirculation system for an engine (1), wherein at least a downstream sub-region of a region of an exhaust passage (33) upstream of a turbine wheel (52) is divided into two sub-passages (R1, R2) by a partition wall (20a, 30a) extending along an exhaust gas flow direction. A high-speed sub-passage (R2) in the two sub-passages (R1, R2) is equipped with an openable-closable exhaust variable valve (23). The exhaust variable valve (23) is configured to be controlled to open the high-speed sub-passage (R2) when an engine speed is equal to or greater than a reference speed, and close the high-speed sub-passage (R2) when the engine speed is less than the reference speed. An inlet (60a) of an EGR passage (60) on the side of the exhaust passage (33) is opened to the high-speed sub-passage (R2) at a position downstream of the exhaust variable valve (23).