The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 09, 1999
Filed:
Aug. 14, 1997
Yukio Kinugasa, Susono, JP;
Takaaki Itou, Mishima, JP;
Koichi Hoshi, Susono, JP;
Koichi Takeuchi, Susono, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi-Ken, JP;
Abstract
A device for purifying exhaust gas includes an HC adsorbent and an exhaust gas purifying catalyst disposed in an exhaust gas passage in this order from the upstream side. The exhaust gas purifying catalyst is provided with an O.sub.2 storage capability, i.e., the exhaust gas purifying catalyst is capable of absorbing oxygen in the exhaust gas when the air-fuel ratio of the exhaust gas is lean, and is capable of releasing the absorbed oxygen when the air-fuel ratio of the exhaust gas becomes rich. When the engine starts, the HC adsorbent adsorbs HC in the exhaust gas. When the temperature of the exhaust gas becomes high, the HC adsorbent releases the adsorbed HC. The device also includes an engine control unit which operates the engine at a lean air-fuel ratio during a predetermined period before the releasing of the HC from the HC adsorbent occurs. Therefore, oxygen is absorbed and stored in the exhaust gas purifying catalyst before the releasing of HC occurs. When the releasing of HC from the HC adsorbent occurs, the air-fuel ratio of the exhaust gas flowing into the exhaust gas purifying catalyst becomes rich due to the HC released from the HC adsorbent. This causes the exhaust gas purifying catalyst to release the absorbed oxygen, and the HC in the exhaust gas is purified by the exhaust gas purifying catalyst using the released oxygen.