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US 6,332,966 B1Granted
Air/fuel ratio detecting arrangement
AssigneesUnisia Jecs Corporation, Nissan Motor Co., Ltd.
InventorsShoichi Sakai, Futoshi Ichiyanagi, Toshiaki Inoue
Life of this patent
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Abstract
An A/F ratio detecting arrangement includes a sensor casing having an oxygen sensor part arranged between first and second electrodes and an oxygen pump part arranged between third and fourth electrodes, which are heated by a heater. A signal output processing circuit serves to provide an A/F ratio signal. A signal switcher serves to provide a provisional oxygen content signal derived from the first and second electrodes when the oxygen pump part is not activated yet, and the A/F ratio signal when the oxygen pump part is activated.
Claims16
An arrangement for detecting an air/fuel (A/F) ratio, comprising:
- a casing having a gas cell into which exhaust gas flows and an air cell isolated from said gas cell, said casing including an outer periphery;
- first, second, third and fourth electrodes located in said air cell, said gas cell, said gas cell and at said outer periphery, respectively;
- an oxygen sensor part arranged with said casing, said oxygen sensor part providing an oxygen content signal indicative of a difference in oxygen content between said air cell and said gas cell through said first and second electrodes;
- an oxygen pump part arranged with said casing, said oxygen pump part urging oxygen ions to flow into and out of said gas cell through said casing in accordance with an oxygen pump signal received between said third and fourth electrodes;
- a heater arranged with said casing, said heater heating said oxygen sensor part and said oxygen pump part;
- a processing circuit which provides said oxygen pump signal to said third and fourth electrodes in accordance with said oxygen content signal and an A/F ratio signal indicative of an oxygen content in said gas cell in accordance with an electric power amount supplied to said third and fourth electrodes by said oxygen pump signal;
- a signal switching circuit which provides either of said A/F ratio signal or one of said oxygen content signal and a provisional oxygen content signal derived from said first and fourth electrodes;
- and
- an electronic control unit (ECU) connected to said signal switching circuit, said ECU being constructed to carry out an A/F ratio control by using said provisional oxygen content signal before an activation of said oxygen sensor part is determined in accordance with either of said oxygen content signal or said provisional oxygen content signal, and to provide a switching signal to said signal switching circuit for providing said A/F ratio signal when said activation is determined.
6 more elements
An arrangement for detecting an air/fuel (A/F) ratio, comprising:
- a casing having a gas cell into which exhaust gas flows and an air cell isolated from said gas cell, said casing including an outer periphery;
- first, second, third and fourth electrodes located in said air cell, said gas cell, said gas cell and at said outer periphery, respectively;
- an oxygen sensor part arranged with said casing, said oxygen sensor part providing an oxygen content signal indicative of a difference in oxygen content between said air cell and said gas cell through said first and second electrodes;
- an oxygen pump part arranged with said casing, said oxygen pump part urging oxygen ions to flow into and out of said gas cell through said casing in accordance with an oxygen pump signal received between said third and fourth electrodes;
- a heater arranged with said casing, said heater heating said oxygen sensor part and said oxygen pump part;
- a processing circuit which provides said oxygen pump signal to said third and fourth electrodes in accordance with said oxygen content signal and an A/F ratio signal indicative of an oxygen content in said gas cell in accordance with an electric power amount supplied to said third and fourth electrodes by said oxygen pump signal;
- a signal amplifier circuit which amplifies said A/F ratio signal to provide an amplified A/F ratio signal;
- a signal switching circuit which provides either of said A/F ratio signal or said amplified A/F ratio signal;
- and
- an electronic control unit (ECU) which provides, upon determination of activation of said oxygen pump part in accordance with said amplified A/F ratio signal, a switching signal to said signal switching circuit for providing said A/F ratio signal.
7 more elements
An arrangement for detecting an air/fuel (A/F) ratio, comprising:
- a casing having a gas cell into which exhaust gas flows and an air cell isolated from said gas cell, said casing including an outer periphery;
- first, second, third and fourth electrodes located in said air cell, said gas cell, said gas cell and at said outer periphery, respectively;
- an oxygen sensor part arranged with said casing, said oxygen sensor part providing an oxygen content signal indicative of a difference in oxygen content between said air cell and said gas cell through said first and second electrodes;
- an oxygen pump part arranged with said casing, said oxygen pump part urging oxygen ions to flow into and out of said gas cell through said casing in accordance with an oxygen pump signal received between said third and fourth electrodes;
- a heater arranged with said casing, said heater heating said oxygen sensor part and said oxygen pump part;
- means for providing said oxygen pump signal to said third and fourth electrodes in accordance with said oxygen content signal and an A/F ratio signal indicative of an oxygen content in said gas cell in accordance with an electric power amount supplied to said third and fourth electrodes by said oxygen pump signal;
- means for providing in a switched way either of said A/F ratio signal or one of said oxygen content signal and a provisional oxygen content signal derived from said first and fourth electrodes;
- and
- means connected to said signal switching circuit for carrying out an A/F ratio control by using said provisional oxygen content signal before an activation of said oxygen sensor part is determined in accordance with either of said oxygen content signal or said provisional oxygen content signal, and for providing a switching signal to said signal switching circuit for providing said A/F ratio signal when said activation is determined.
6 more elements
An arrangement for detecting an air/fuel (A/F) ratio, comprising:
- a casing having a gas cell into which exhaust gas flows and an air cell isolated from said gas cell, said casing including an outer periphery;
- first, second, third and fourth electrodes located in said air cell, said gas cell, said gas cell and at said outer periphery, respectively;
- an oxygen sensor part arranged with said casing, said oxygen sensor part providing an oxygen content signal indicative of a difference in oxygen content between said air cell and said gas cell through said first and second electrodes;
- an oxygen pump part arranged with said casing, said oxygen pump part urging oxygen ions to flow into and out of said gas cell through said casing in accordance with an oxygen pump signal received between said third and fourth electrodes;
- a heater arranged with said casing, said heater heating said oxygen sensor part and said oxygen pump part;
- means for providing said oxygen pump signal to said third and fourth electrodes in accordance with said oxygen content signal and an A/F ratio signal indicative of an oxygen content in said gas cell in accordance with an electric power amount supplied to said third and fourth electrodes by said oxygen pump signal;
- means for amplifying said A/F ratio signal to provide an amplified A/F ratio signal;
- means for providing in a switched way either of said A/F ratio signal or said amplified A/F ratio signal;
- and
- means for providing, upon determination of activation of said oxygen pump part in accordance with said amplified A/F ratio signal, a switching signal to said signal switching circuit for providing said A/F ratio signal.
7 more elements
Dependencies are inferred from the claim text.