{
  "$type": "site.standard.document",
  "description": "An exhaust gas purifying apparatus comprises a control unit (29) operative to estimate an amount of NOx absorbed by a NOx trap material (17) disposed in an exhaust passage (10) and to make an air-fuel ratio richer so as thereby to cause the NOx trap material to release sulfur when the estimated…",
  "path": "/patents/1099403",
  "publishedAt": "2003-01-02T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F01N3/0842",
    "MAZDA MOTOR [JP]"
  ],
  "textContent": "An exhaust gas purifying apparatus comprises a control unit (29) operative to estimate an amount of NOx absorbed by a NOx trap material (17) disposed in an exhaust passage (10) and to make an air-fuel ratio richer so as thereby to cause the NOx trap material to release sulfur when the estimated amount of NOx absorption exceeds a specified amount. Further, the control unit (29) operative to estimate an amount of sulfur absorbed by the NOx trap material (17) and to make an air-fuel ratio richer and rising a temperature of exhaust gas so as thereby to cause the NOx trap material to release sulfur when the estimated amount of sulfur absorption exceeds a specified amount. The control means restricts an air-fuel ratio from being made richer when the NOx trap material is not expected to absorb NOx due to progress of sulfur absorption resulting from conditionally the sulfur releasing.",
  "title": "Exhaust gas purifying apparatus for internal combustion engine"
}