Patent ID: 7299624
Filing Date: 2007-11-27
Classification: F01N,F02D,Y02A,Y02T

Abstract:
1. An exhaust gas purifying apparatus provided in an exhaust passage connected with an engine, comprising: an upstream catalyst, provided in the exhaust passage, that removes NOx, the upstream catalyst being a three-way catalyst; a downstream catalyst provided downstream of the upstream catalyst in the exhaust passage; a supply device that supplies an oxygen-activating component to a portion of the exhaust passage located between the upstream catalyst and the downstream catalyst; a temperature detection device that detects a temperature of the exhaust passage; and a control device that changes an amount of the oxygen activating component supplied by the supply device, based on a temperature detected by the temperature detection device, wherein: when the temperature detected by the temperature detection device is equal to or higher than a first predetermined temperature, the control device controls the supply device to stop supplying the oxygen-activating component, when the temperature detected by the temperature detection device is lower than the first predetermined temperature and equal to or higher than a second predetermined temperature, which is lower than the first predetermined temperature, the control device controls the supply device to supply the oxygen-activating component in a first predetermined amount, and when the temperature detected by the temperature detection device is lower than the second predetermined temperature, the control device controls the supply device to supply the oxygen-activating component in a second predetermined amount, which is larger than the first predetermined amount.