| 摘要 |
PROBLEM TO BE SOLVED: To prevent emission of NOx from a catalyst when a catalyst temperature is increased and discharge of it in the atmosphere. SOLUTION: When zeolite of a catalyst is in a temperature state to effect emission of NOx (S5), a fuel injection form is varied, pilot injection is executed, and a main fuel injection timing is delayed (S6). By increasing an exhaust gas temperature, early activation of the catalyst is performed and NOx emitted from zeolite is reduced and purified by a catalyst metal Pt. |
