{
  "$type": "site.standard.document",
  "description": "An exhaust gas purification device for an internal combustion engine which operates at a lean air-fuel ratio and at the stoichiometric air-fuel ratio or at a rich air-fuel ratio as required, comprising: an exhaust gas purifying catalyst (5) disposed in an exhaust gas passage of the engine and…",
  "path": "/patents/1077492",
  "publishedAt": "2005-06-01T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F01N13/009",
    "TOYOTA MOTOR CO LTD [JP]"
  ],
  "textContent": "An exhaust gas purification device for an internal combustion engine which operates at a lean air-fuel ratio and at the stoichiometric air-fuel ratio or at a rich air-fuel ratio as required, comprising: an exhaust gas purifying catalyst (5) disposed in an exhaust gas passage of the engine and having an O2 storage capability; an NOx occluding and reducing catalyst (7) disposed in said exhaust gas passage on the downstream side of said exhaust gas purifying catalyst (5) to absorb NOx when the air-fuel ratio is lean and to release the absorbed NOx when the oxygen concentration in the exhaust gas flowing in has decreased; an NOx occlusion amount-estimating means for estimating the amount of NOx occluded by said NOx occluding and reducing catalyst (7); and an NOx occlusion amount correction means for correcting the estimated occluded amount of NOx based on the amount of oxygen stored in catalyst (5).",
  "title": "An exhaust gas purification device for an internal combustion engine"
}