Direct injection type internal combustion engine and controlling method therefor

A method for controlling a direct injection internal combustion engine, comprising:

• carrying out an intake operation and an exhaust operation for a predetermined period of time between a second half of a second expansion stroke and a first half of a first compression stroke following said second expansion stroke to sequentially repeat said first compression stroke, a first expansion stroke, a second compression stroke, and said second expansion stroke, constituting an irregular four-cycle operation, along with rotation of a crank shaft in said internal combustion engine;
• injecting first fuel during said first compression stroke;
• and
• injecting second fuel during one of said first expansion stroke and said second compression stroke.

A method for controlling a direct injection internal combustion engine, comprising:

• carrying out an intake operation and an exhaust operation for a predetermined period of time between a second half of a second expansion stroke and a first half of a first compression stroke following said second expansion stroke to sequentially repeat said first compression stroke, a first expansion stroke, a second compression stroke, and said second expansion stroke along with rotation of a crank shaft in said internal combustion engine;
• injecting first fuel during said first compression stroke;
• and
• injecting second fuel during one of said first expansion stroke and said second compression stroke when a rotational speed of said internal combustion engine is lower than a first predetermined value and a load on said internal combustion engine is lower than a second predetermined value.