| 摘要 |
<p>PROBLEM TO BE SOLVED: To retain good fuel economy and an exhaust gas property by exactly estimating NOx quantity absorbed to an NOx absorbent and carrying out reduction rich with appropriate timing even if atmospheric pressure is varied. SOLUTION: An increased value CTSV corresponding to NOx exhaust quantity per unit time is calculated in accordance with engine speed NE and absolute pressure in an intake pipe PBA (S25). Atmospheric pressure correction coefficient KPA for correcting fuel supply quantity in accordance with atmospheric pressure PA detected by means of an atmospheric pressure sensor 21 is calculated. When the atmospheric pressure correction coefficient KPA is higher than 1, namely, in traveling on a high ground, increased value correction coefficient KCTSV is calculated in accordance with the KPA value (S26, S27). The increased value CTSV is corrected by the correction coefficient KCTSV.</p> |
