(1) Pilot injection
• Pilot injection entails the injection of an extremely small amount of fuel ahead of the main injection.
• Pilot injection suppresses heat generation early in the injection cycle and thus suppresses NOx generation and noise at the start of combustion.
(2) Split injection control
• Split injection entails the injection of an extremely small amount of fuel two or more times ahead of the main injection.
• This improves the ignitability of fuel and realizes better startability at cold engine and reduction of HC at low-load operation.
(3) Post injection
• Fuel injection control for diesel particular filter regeneration is performed in such a way, with early post injection and late post injection added after conventional fuel injection (main injection), exhaust gas temperature is increased to burn out particulate matter (PM) collected in the DPF.