发明名称 |
System for diagnosing deterioration of catalyst |
摘要 |
A diagnostic system in which the accuracy of the diagnosis of the deterioration state of a catalyst (40 in Fig. 1) in a catalytic converter (4) for cleaning the exhaust gas of an internal combustion engine (2) is enhanced without incurring a rise in cost. The temperature of the catalyst (40) is estimated using the operating-state signal (for example, the flow rate of intake air Qa or the width 120 of a fuel injection pulse) of the engine (2) by a diagnostic device (8). The conversion efficiency of the catalyst (40) calculated from the outputs of oxygen sensors (6a, 6b) is corrected using the estimated temperature by the diagnostic device (8). The deterioration state of the catalyst (40) is diagnosed on the basis of the corrected temperature by the diagnostic device (8). <IMAGE> |
申请公布号 |
EP0844374(A3) |
申请公布日期 |
1998.07.29 |
申请号 |
EP19980101528 |
申请日期 |
1994.04.26 |
申请人 |
HITACHI, LTD. |
发明人 |
MUKAIHIRA, TAKASHI;MIURA, KIYOSHI;ISHII, TOSHIO;KAWANO, KAZUYA |
分类号 |
F01N3/20;F01N7/00;F01N9/00;F01N11/00;F02D41/14;F02D41/22;F02D45/00 |
主分类号 |
F01N3/20 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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