A method of controlling an engine is provided, the method including the steps of injecting main fuel by a fuel injector during an intake stroke or a compression stroke, providing a mixture gas containing fuel and air inside a cylinder, applying by an ignition device a high voltage between electrodes of a spark plug at a timing when the mixture gas is not ignited, detecting a parameter related to a current value of an electric-discharge channel generated between the electrodes, determining whether the detected parameter is within a range between a first threshold and a second threshold to determine a flowing state of a vortex inside the cylinder, injecting supplemental fuel by the fuel injector after the main fuel injection when the parameter is determined to be outside the range, and igniting the mixture gas by the ignition device using the spark plug after the supplemental fuel injection.

The invention is provided with an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Timing of the preceding ignition is set to be more retarded when an engine speed is high than when the engine speed is low.

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.

A method for operating an internal combustion engine including a step of concurrently introducing at least two combustible fuel jets into a combustion chamber of an internal combustion engine. A first combustible fuel jet of the at least two combustible fuel jets is ignited at an ignition time point. In a first operating mode of the internal combustion engine a second combustible fuel jet which is different from the first combustible fuel jet of the at least two combustible fuel jets is ignited after the ignition time point.

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.

The invention is provided with an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Timing of the preceding ignition is more advanced when a swirl flow is gentle than when the swirl flow is strong.

An internal combustion engine includes multiple fuel injections external to a pre-chamber. A further aspect provides an engine pre-chamber ignition apparatus which employs a pre-assembled and/or removable cartridge including an ignitor and a fresh air inlet but not a fuel inlet injector directly mounted thereto. Another aspect of a vehicular engine apparatus includes a fuel injector positioned externally to a pre-chamber which delivers an initial greater quantity of fuel for combustion and then a later and smaller quantity of fuel for pre-chamber ignition.

An engine control apparatus includes an ignition control section and an injection control section. When the partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of a expansion stroke to initiate the SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes the injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. The energy of the preceding ignition is set to be higher when fuel concentration specified by a fuel concentration specification section is low than when the fuel concentration is high.

An engine apparatus includes an ignition control section and an injection control section. When the partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate the SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes the injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Energy of the preceding ignition is set to be lower when a swirl flow is gentle than when the swirl flow is intense.

A control apparatus for a compression-ignition type engine is applied to an engine capable of carrying out partial compression ignition combustion in which an air-fuel mixture is subjected to CI combustion by self-ignition. The control apparatus creates a lean A/F environment where an air-fuel ratio as a ratio between air and fuel in a cylinder exceeds 20 and is lower than 35, or a lean G/F environment where a gas air-fuel ratio as a ratio between entire gas and the fuel in the cylinder exceeds 18 and is lower than 50 and the air-fuel ratio substantially matches a stoichiometric air-fuel ratio. Prior to planned timing of the CI combustion, in the lean A/F environment or the lean G/F environment, the control apparatus causes an ignition plug to generate a spark and to generate a high-temperature portion.