{
  "$type": "site.standard.document",
  "description": "Rich spike is carried out in an efficient manner. In an exhaust gas purification apparatus for an internal combustion engine which performs lean burn operation, the apparatus includes an NOx storage reduction catalyst, a controller to carry out rich spike, to calculate a storage amount of NOx, to…",
  "path": "/patents/1237458",
  "publishedAt": "2019-06-27T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "F01N3/0814",
    "TOYOTA JIDOSHA KABUSHIKI KAISHA"
  ],
  "textContent": "Rich spike is carried out in an efficient manner. In an exhaust gas purification apparatus for an internal combustion engine which performs lean burn operation, the apparatus includes an NOx storage reduction catalyst, a controller to carry out rich spike, to calculate a storage amount of NOx, to calculate a storage amount of nitrates, and calculate a nitrate ratio, wherein the controller controls a timing at which the rich spike is carried out, based on the nitrate ratio.",
  "title": "EXHAUST GAS PURIFICATION APPARATUS FOR AN INTERNAL COMBUSTION ENGINE"
}