摘要 |
<p>A secondary air supply system includes a secondary air supply device (60) that supplies secondary air to the upstream side of an exhaust emission control device (5) installed in an exhaust system of an internal combustion engine (l), and an ECU (20) that estimates the secondary air temperature, and estimates the exhaust gas temperature after supply of secondary air, based on the result of estimation. The ECU (20) starts or inhibits supply of secondary air by the secondary air supply device (60), depending on the result of estimation of the exhaust gas temperature. It is thus possible to prevent discharge of unburned fuel components, by estimating the exhaust gas temperature after supply of secondary air in view of the secondary air temperature.</p> |