| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine capable of early activating a catalyst, after preventing deterioration of fuel consumption by enriching of exhaust air/fuel ratio and preventing increase in a drive loss by an air pump, at cold starting time or the like. SOLUTION: A catalyst activated at a low temperature by making CO and O2 in exhaust gas react is provided, two-step injection executing fuel injection divided into a compression stroke and an expansion stroke is executed (step S6) when cold starting is decided (step S2 is YES). In this two-step injection, O2 by combustion of excessive oxygen in the compression stroke and CO by incomplete combustion in the expansion stroke are simultaneously generated, these CO and O2 are supplied with exhaust gas onto the catalyst, by heat of reaction thereof, a temperature of the catalyst is increased. Accordingly, necessity for enriching for supplying CO and necessity for supplying secondary air for supplying O2 are eliminated.</p> |
