Device for reactivating catalyst of engine
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsShinya Hirota, Toshiaki Tanaka
Life of this patent
Estimating the term…
Abstract
A catalyst is housed in a casing arranged in the exhaust passage of the engine. A pressure reducing valve, which is usually closed, is arranged in a bypass passage branching off from the exhaust passage upstream of the casing. The fuel injector usually injects fuel at the combustion stroke or the exhaust stroke to feed hydrocarbon, and NOX is reduced in the catalyst by the hydrocarbon. When the catalyst is judged to be poisoned, the timing of the secondary fuel injection is advanced with respect to the timing of the usual secondary fuel injection, and the pressure reducing valve is opened to reduce the pressure in the casing. In this way, the catalyst is reactivated.
Claims22
A device for reactivating a catalyst of an engine having an exhaust passage, the catalyst being housed in a catalyst casing arranged in the exhaust passage, the device comprising:
- heating means which is able to heat the catalyst;
- pressure reducing means which is able to reduce the pressure in the catalyst casing including an escaping passage branching off from the exhaust passage upstream of the catalyst casing that introduces a part of the exhaust gas to the escaping passage;
- reactivating means for reactivating the catalyst by controlling the heating means and the pressure reducing means to heat the catalyst and reduce the pressure in the catalyst casing to release a sulphur containing component or a soluble organic fraction from the catalyst;
- judging means included in the reactivating means for judging whether the catalyst is poisoned by a sulphur containing component or a soluble organic fraction;
- wherein
- the reactivating means reactivates the catalyst when the catalyst is judged to be poisoned.
Dependencies are inferred from the claim text.