| 摘要 |
<p>Even in the case of driving for a long time in the low rotation speed driving condition in which the exhaust flow rate is small and an estimation of the PM accumulated amount due to the pressure difference between the front and the back sides of a filter is difficult, the forced regeneration time can be accurately judged, the deterioration of fuel efficiency that is caused by excessive PM trapping can be avoided, and at the same time, thermal runaway that is generated by the excessive accumulated amount of PM and melting damage of the DPF due to this thermal runaway can be prevented.
In the exhaust gas purification system 1 that performs a forced regeneration control by judging a forced regeneration starting time of the DPF 12b from the pressure difference ”Pm between the front and the back sides of the DPF 12b, in the case of detecting that the driving condition of the internal combustion engine 10 is a low rotation speed driving condition, the sustaining time tm of the low rotation speed driving condition is measured, and when the measured sustaining time tm exceeds the predetermined time for judgment tc, the forced regeneration control of the DPF 12b is performed without affecting the pressure difference ”Pm between the front and the back sides of the DPF 12b.</p> |
