| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a diesel engine capable of curbing a problem with an excessive PM (particulate matter) accumulation amount on a DPF (a diesel particulate filter).SOLUTION: In a diesel engine, when the same is in a DPF regeneration mode and a DOC (a diesel oxidation catalyst) inlet exhaust temperature T is not less than a post injection lower limit temperature TN, unburnt fuel mixed in exhaust is burnt through catalyst combustion of a DOC and PMs accumulated on a DPF is burnt and removed with temperature increased by exhaust in a manner that allows a common rail type fuel injection device to execute a post injection following a main injection in accordance with an instruction of a fuel injection control device (S6). When an estimated value E of an exhaust flow rate is equal to a predetermined reference flow rate E1, the post injection lower limit temperature TN is set at a predetermined reference lower limit temperature T1 (S4). When the estimated value E of the exhaust flow rate is a small flow rate E0 less than the predetermined reference flow rate E1, the post injection lower limit temperature TN is set at a lower limit temperature T0 less than the reference lower limit temperature T1 (S10).</p> |
