| 摘要 |
An exhaust gas purification system has a NOx purification catalyst (22), and the catalyst (22) purifies exhaust gas of NOx when the air-fuel ratio of exhaust of an internal combustion engine (E) mounted on a vehicle is in a lean condition and recovers purification ability when the air-fuel ratio is in a rich condition. The system performs recovery control for setting the exhaust gas to a rich air-fuel condition in order to recover the NOx purification ability of the NOx purification catalyst (22), and at the time of retardation of the vehicle, both a fuel system rich control and an air intake rich control are used in the recovery control. The recovery control can be performed without worsening the drive comfort of the vehicle and with deterioration fuel of fuel consumption involved in the recovery control suppressed. |
