| 摘要 |
PROBLEM TO BE SOLVED: To provide a combustion control device capable of realizing appropriate premixed compression ignition combustion even during transient operation of premixed compression ignition combustion or during combustion switching from normal combustion to the premixed compression ignition combustion.SOLUTION: A combustion control device determines a fuel injection quantity on the basis of an engine rotational speed and an accelerator opening, determines fuel injection timing on the basis of the engine rotational speed, the fuel injection quantity, and a combustion method, and then estimates an ignition delay on the basis of an in-cylinder oxygen amount, an in-cylinder gas temperature before fuel injection, the fuel injection timing, the engine rotational speed, a fuel injection pressure, an external temperature, an atmospheric pressure, and a cooling water temperature to obtain an estimated ignition delay τ. A fuel-injection-condition setting unit obtains a target ignition delay τon the basis of the engine rotational speed, the fuel injection quantity, the external temperature, the atmospheric pressure, and the cooling water temperature, calculates an ignition delay deviation &Dgr;τbetween the estimated ignition delay τ and the target ignition delay τ, and determines the fuel injection quantity and the fuel injection timing of preliminary injection if the estimated ignition delay τ is shorter than the target ignition delay τby a predetermined amount or more. |
