An engine is provided, which includes a combustion chamber defined by a cylinder head and a piston inside a cylinder of a cylinder block, a fuel injection nozzle provided to the cylinder head and formed in a tip-end part with a plurality of injection holes from which fuel is injected into the combustion chamber, the tip-end part being exposed to the combustion chamber, and a passage-forming member formed with a passage through which the injected fuel passes. The injection holes include first and second injection holes, and the passage-forming member is disposed around the tip-end part of the nozzle so as to cause a difference between a speed at which fuel injected from the first injection hole flows toward a circumferential part of the combustion chamber, and a speed at which fuel injected from the second injection hole flows toward the circumferential part.

Methods and systems for supplying post injection fuel to a two stroke diesel engine are described. In one example, post injection fuel timing is adjusted responsive to an amount of internal residual combustion products in a cylinder so that less post injected fuel may be trapped in the cylinder for a subsequent cycle of the cylinder. The start of post injection fuel timing and the amount of post injection fuel may be adjusted responsive to internal residual in the cylinder.

Methods and systems for supplying post injection fuel to a two stroke diesel engine are described. In one example, post injection fuel timing is adjusted responsive to an amount of internal residual combustion products in a cylinder so that less post injected fuel may be trapped in the cylinder for a subsequent cycle of the cylinder. The start of post injection fuel timing and the amount of post injection fuel may be adjusted responsive to internal residual in the cylinder.

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 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 sequentially performs a first injection and a second injection in an intake stroke. The controller makes an injection amount of the second injection greater than that of the first injection.

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 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 sequentially performs a first injection and a second injection in an intake stroke. The controller makes an injection amount of the second injection greater than that of the first injection.

A control apparatus for a compression-ignition type engine is applied to an engine capable of carrying out partial compression ignition combustion. When the partial compression ignition combustion is carried out, an ignition control section of the control apparatus causes an ignition plug to carry out: main ignition in which a spark is generated to initiate the SI combustion; and preceding ignition in which the spark is generated at an earlier time point than the main ignition. An injection control section causes the ignition plug to inject fuel in an intake stroke. The ignition control section sets energy of the preceding ignition to be lower than energy of the main ignition and causes the ignition plug to carry out the preceding ignition after the fuel injection in the intake stroke or an early period or a middle period of a compression stroke.

Control is performed so as to occur SPCCI combustion in which, after an air-fuel mixture in a first area of a combustion chamber that includes an electrode portion of an ignition device is burned by receiving ignition energy, an air-fuel mixture formed in a second area located on an outer periphery of the first area is self-ignited. Control is also performed such that, in a high load operation region of an SPCCI combustion execution region, an air-fuel ratio in the entire combustion chamber becomes richer than a stoichiometric air-fuel ratio and that an air-fuel ratio of the air-fuel mixture in the first area becomes leaner than an air-fuel ratio of the air-fuel mixture in the second area.

Control is performed so as to occur SPCCI combustion in which, after an air-fuel mixture in a first area of a combustion chamber that includes an electrode portion of an ignition device is burned by receiving ignition energy, an air-fuel mixture formed in a second area located on an outer periphery of the first area is self-ignited. Control is also performed such that, in a high load operation region of an SPCCI combustion execution region, an air-fuel ratio in the entire combustion chamber becomes richer than a stoichiometric air-fuel ratio and that an air-fuel ratio of the air-fuel mixture in the first area becomes leaner than an air-fuel ratio of the air-fuel mixture in the second area.

When the geometric compression ratio of an engine body is set to 13:1 or more and the engine body operates in a preset high load region, the effective compression ratio of the engine body is set to 12:1 or more with a difference from the geometric compression ratio being within 2, a gas to be introduced into a combustion chamber is supercharged by a supercharging system, fuel is injected at least in a compression stroke by an injector, and after the fuel injection is finished, an air-fuel mixture in the combustion chamber is ignited by an ignition device before the compression top dead center and is thus burned by flame propagation in the engine body, and then the unburned air-fuel mixture is burned by compression ignition.

When the geometric compression ratio of an engine body is set to 13:1 or more and the engine body operates in a preset high load region, the effective compression ratio of the engine body is set to 12:1 or more with a difference from the geometric compression ratio being within 2, a gas to be introduced into a combustion chamber is supercharged by a supercharging system, fuel is injected at least in a compression stroke by an injector, and after the fuel injection is finished, an air-fuel mixture in the combustion chamber is ignited by an ignition device before the compression top dead center and is thus burned by flame propagation in the engine body, and then the unburned air-fuel mixture is burned by compression ignition.