{
  "$type": "site.standard.document",
  "description": "A catalyst 3 which has oxygen storage performance is installed in an engine exhaust passage 2, an oxygen storage amount is estimated based on the output of an upstream air-fuel ratio sensor 4 installed in the upstream of the catalyst 3, and an air-fuel ratio is controlled so that this oxygen…",
  "path": "/patents/1110611",
  "publishedAt": "2001-08-29T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F02D41/0295",
    "NISSAN MOTOR [JP]"
  ],
  "textContent": "A catalyst 3 which has oxygen storage performance is installed in an engine exhaust passage 2, an oxygen storage amount is estimated based on the output of an upstream air-fuel ratio sensor 4 installed in the upstream of the catalyst 3, and an air-fuel ratio is controlled so that this oxygen storage amount coincides with a target value. When the output of a downstream air-fuel ratio sensor 5 has become lean or rich for longer than a fixed time, the output of the upstream air-fuel ratio sensor 4 is corrected based on the output of the downstream air-fuel ratio sensor 5 placed in the downstream of the catalyst 3. In this way, the output fluctuation due to deterioration of the air-fuel ratio sensor 4 upstream of the catalyst is corrected, and the catalyst oxygen storage amount is always precisely controlled to the target value.",
  "title": "Engine air-fuel ratio controller"
}