Abstract: An internal combustion engine is provided, which includes a variable phase mechanism configured to change rotational phases of intake and exhaust camshafts so that a valve overlap is made. An intake cam lobe is formed such that an open period of the intake valve is 210° or larger and 330° or smaller of a crank angle. The exhaust cam lobe is formed such that, during the overlap period with the rotational phase of the intake camshaft advanced to the maximum and the rotational phase of the exhaust camshaft retarded to the maximum, an effective valve lift amount (Lift(CA)) of the exhaust valve which is a function of a crank angle from the open timing (CAIVO) of the intake valve to a middle timing (CAcenter) of the overlap period, an inner circumferential length (L_ex) of a valve seat, and a swept volume (V) per cylinder satisfy the following formula: 0 . 0 ? 1 ? 5 ? L_ex V × ? C ? A IVO C ? A c ? e ? n ? t ? e ? r ? ? Lif ? t ? ? ( CA ) ? d ? C ? A .

Abstract: An internal combustion engine is provided, which includes a variable phase mechanism configured to change rotational phases of intake and exhaust camshafts so that a valve overlap is made. An intake cam lobe is formed such that an open period of the intake valve is 210° or larger and 330° or smaller of a crank angle. The exhaust cam lobe is formed such that, during the overlap period with the rotational phase of the intake camshaft advanced to the maximum and the rotational phase of the exhaust camshaft retarded to the maximum, an effective valve lift amount (Lift(CA)) of the exhaust valve which is a function of a crank angle from the open timing (CAIVO) of the intake valve to a middle timing (CAcenter) of the overlap period, an inner circumferential length (L_ex) of a valve seat, and a swept volume (V) per cylinder satisfy the following formula: 0 . 0 ? 1 ? 5 ? L ? _ ? ex V × ? C ? A IVO C ? A c ? e ? n ? t ? e ? r ? Lift ? ( CA ) ? d ? C ? A .

Abstract: A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. An spark plug ignites the lean mixture gas to cause the mixture gas to start combustion accompanied by flame propagation, and then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by the swirl flow. The fuel injector sequentially performs first and second injections in an intake stroke. A ratio of an injection amount of the second injection to the entire amount of fuel required per cycle is increased as an engine load increases.

Abstract: A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. A spark plug ignites the lean mixture gas to cause a portion of the mixture gas to start combustion accompanied by flame propagation, and then combusts by self-ignition. The fuel injector has first and second nozzle holes, and a first atomized fuel spray injected from the first nozzle hole and a second atomized fuel spray injected from the second nozzle hole separate from each other by the swirl flow. The fuel injector performs the fuel injection in an intake stroke, and retards a start timing of the injection when an engine load is high compared to that when the load is low.

Abstract: A fuel injection control device for an engine is provided. A fuel injector with multiple nozzle holes forms a lean mixture gas inside a combustion chamber, a spark plug ignites to cause the mixture gas to start combustion accompanied by flame propagation, then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by a swirl flow, and a third atomized fuel spray injected from a third nozzle hole and a fourth atomized fuel spray from a fourth nozzle hole approach each other by the swirl flow so that a first area and a second area where mixture gas is richer are formed inside the combustion chamber. The fuel injector sequentially performs first, second, and third injections with an injection interval therebetween in an intake stroke.

Abstract: A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. A spark plug ignites the lean mixture gas to cause a portion of the mixture gas to start combustion accompanied by flame propagation, and then combusts by self-ignition. The fuel injector has first and second nozzle holes, and a first atomized fuel spray injected from the first nozzle hole and a second atomized fuel spray injected from the second nozzle hole separate from each other by the swirl flow. The fuel injector performs the fuel injection in an intake stroke, and retards a start timing of the injection when an engine load is high compared to that when the load is low.

Abstract: A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. An spark plug ignites the lean mixture gas to cause the mixture gas to start combustion accompanied by flame propagation, and then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by the swirl flow. The fuel injector sequentially performs first and second injections in an intake stroke. A ratio of an injection amount of the second injection to the entire amount of fuel required per cycle is increased as an engine load increases.

Abstract: A fuel injection control device for an engine is provided. A fuel injector with multiple nozzle holes forms a lean mixture gas inside a combustion chamber, a spark plug ignites to cause the mixture gas to start combustion accompanied by flame propagation, then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by a swirl flow, and a third atomized fuel spray injected from a third nozzle hole and a fourth atomized fuel spray from a fourth nozzle hole approach each other by the swirl flow so that a first area and a second area where mixture gas is richer are formed inside the combustion chamber. The fuel injector sequentially performs first, second, and third injections with an injection interval therebetween in an intake stroke.