| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine exhaust gas purifier capable of restoring sulfur poisoning in a short time period. <P>SOLUTION: The internal combustion engine exhaust gas purifier in which an NO<SB>x</SB>storage catalyst is disposed in the path for an engine exhaust gas, an air-fuel ratio sensor for controlling a feedback is disposed on the downstream side of the NO<SB>x</SB>storage catalyst, and a fuel addition valve is disposed on the upstream side of the NO<SB>x</SB>storage catalyst, performs the restoration from sulfur poisoning by alternately repeating a temperature rise control for raising the temperature of the NO<SB>x</SB>storage catalyst by supplying a fuel through the fuel addition valve and a SO<SB>x</SB>discharge control for discharging an SO<SB>x</SB>from the NO<SB>x</SB>storage catalyst by carrying out after-injection in the combustion chamber to make rich the air-fuel ratio of the exhaust gas, and learning the output value of the air-fuel ratio sensor is performed, while the air-fuel ratio of the exhaust gas is decreased, immediately after the temperature rise control has been completed by reducing the time period of the temperature rise control and increasing the supply of the fuel through the fuel addition valve for learning the output value of the air-fuel ratio sensor. <P>COPYRIGHT: (C)2010,JPO&INPIT |
