发明名称 |
Method of and apparatus for detecting a deteriorated condition of a wide range air-fuel ratio sensor |
摘要 |
<p>A method of detecting a deteriorated condition of a wide range air-fuel ratio sensor is provided. Firstly, a current is applied to an electromotive force cell to detect a voltage Vs0 across electrodes on opposite side surfaces of the cell. Application of the current is suspended, and a voltage drop Vsd1 across the electrodes is detected after lapse of a time ranging from 10 mu s to 1 ms after the application of the current is suspended. Based on the voltage drop Vsd1 is detected a first resistance value Rvs1 equated to the temperature of the electromotive force cell. Further, after lapse of a time ranging from 10 ms to 50 ms after the application of the current to the electromotive force cell is suspended, a voltage drop Vsd2 across the electrodes of the electromotive force cell is detected. Based on the voltage drop Vsd2 is detected a second resistance value Rvs2 equated to an internal resistance of the electromotive force cell including a resistance component resulting from deterioration. By comparison of the resistance values Rvs1 and Rvs2, the deteriorated condition of the wide range air-fuel ratio is detected. An apparatus for carrying out such a method is also provided. <IMAGE></p> |
申请公布号 |
EP0841478(A2) |
申请公布日期 |
1998.05.13 |
申请号 |
EP19970119445 |
申请日期 |
1997.11.06 |
申请人 |
NGK SPARK PLUG CO. LTD. |
发明人 |
YAMADA, TESSHO;KAWAI, TAKESHI;OI, YUJI;MORI, SHIGEKI;TERAMOTO, SATOSHI;MATSUOKA, TOSHIYA |
分类号 |
F02D41/14;(IPC1-7):F02D41/22 |
主分类号 |
F02D41/14 |
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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