Patent ID: 9683470
Date: 2017-06-20
CPC Classifications: F01N,F02D,Y02T

Claim:
1. An exhaust gas control apparatus for an internal combustion engine comprising an exhaust gas purification catalyst in an exhaust passage, said exhaust gas control apparatus comprising: a fuel injector configured to supply fuel for warming the exhaust gas purification catalyst; an oxygen supplying device configured to supply oxygen to the exhaust purification catalyst; an air-fuel ratio sensor configured to detect an air-fuel ratio within the exhaust gas purification catalyst; and an electronic control unit in communication with the fuel injector, the oxygen supplying device, and the air-fuel ratio sensor, wherein the electronic control unit is configured to: perform a warm-up operation to warm the exhaust gas purification catalyst by increasing the temperature of exhaust gases passing though the exhaust gas purification catalyst via the fuel injector; detect an air-fuel ratio within the exhaust gas purification catalyst via the air-fuel ratio sensor; stop, intermittently, the internal combustion engine based on the air-fuel ratio being detected as rich; and supply oxygen to the exhaust gas purification catalyst via the oxygen supplying device after completion of the warm-up operation and during the intermittent stop of the internal combustion engine.