发明授权
- 专利标题: Method and a device for purifying exhaust gas of an internal combustion engine
- 专利标题(中): 内燃机废气净化方法及装置
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申请号: US911532申请日: 1997-08-14
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公开(公告)号: US5979157A公开(公告)日: 1999-11-09
- 发明人: Yukio Kinugasa , Takaaki Itou , Koichi Hoshi , Koichi Takeuchi
- 申请人: Yukio Kinugasa , Takaaki Itou , Koichi Hoshi , Koichi Takeuchi
- 申请人地址: JPX Aichi-Ken
- 专利权人: Toyota Jidosha Kabushiki Kaisha
- 当前专利权人: Toyota Jidosha Kabushiki Kaisha
- 当前专利权人地址: JPX Aichi-Ken
- 优先权: JPX8-215737 19960815
- 主分类号: F01N3/08
- IPC分类号: F01N3/08 ; F01N3/10 ; F01N3/20 ; F01N3/22 ; F01N3/24 ; F01N3/32 ; F01N9/00 ; F01N13/02 ; F02D41/02 ; F01N3/00
摘要:
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.