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US4724815A
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US
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System of abnormality detection for oxygen concentration sensor
Assignee: Honda Motor Co Ltd
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Filing: 1987-03-27
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Granted: 1988-02-16
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Expires: 2007-03-27
Abstract
Abstract A system of abnormality detection for an oxygen concentration sensor employed to sense the oxygen concentration in engine exhaust gas for obtaining data to control the air/fuel ratio of a fuel mixture supplied to the engine. In which, the oxygen concentration sensor includes a sensor cell element, an oxygen pump element each formed of a pair of electrodes which sandwich a solid electrolytic member, and a heater element for heating the solid electrolytic member. The system functions to detect an abnormality of the heater element on the basis of the value of a voltage developed between the electrodes of the sensor cell element and an air/fuel ratio compensation value that is derived by sensing the exhaust gas oxygen concentration.
Inventors
- 👤 Toshiyuki Mieno
- 👤 Toyohei Nakajima
- 👤 Yasushi Okada
- 👤 Nobuyuki Oono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:30
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/417; F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1493; F02D41/1495; G01N27/403; G01N27/406; G01N27/4065
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
281 words
A system for abnormality detection in an air/fuel ratio control apparatus of an internal combustion engine, comprising: an oxygen concentration sensor including two pairs of electrodes disposed in mutual opposition, with each of the pairs sandwiching an oxygen ion-conductive solid electrolytic member; voltage applying means for applying a pump voltage, determined in accordance with a voltage difference between a sensor voltage which is developed between a first pair of said electrodes and a reference voltage, between a second pair of said electrodes to maintain said sensor voltage at said reference voltage, said voltage applying means thereby producing, as an output which represents an oxygen concentration sensing value, a value of pump current which flows between said second pair of electrodes; a heater element for heating said solid electrolytic member; gas diffusion control means for providing an exhaust gas of an internal combustion engine to the vicinity of one electrode of each of said first and second pairs of electrodes; means for deriving an air/fuel ratio compensation value in accordance with said oxygen concentration sensing value, for controlling an air/fuel ratio of a mixture supplied to said internal combustion engine such as to maintain said air/fuel ratio at a target air/fuel ratio which is determined in accordance with engine operating conditions; drive means for driving an air/fuel ratio control means of said internal combustion engine in accordance with a corrected air/fuel ratio control value which is obtained by applying compensation to an air/fuel ratio control value in accordance with said air/fuel ratio compensation value; and means for detecting an abnormality of said heater element based upon a voltage developed between said first pair of electrodes and upon said air/fuel ratio compensation value.
Claim 2
Independent Claim
281 words
A system for abnormality detection in an air/fuel ratio control apparatus of an internal combustion engine, comprising: an oxygen concentration sensor including two pairs of electrodes disposed in mutual opposition, with each of the pairs sandwiching an oxygen ion-conductive solid electrolytic member; voltage applying means for applying a pump voltage, determined in accordance with a voltage difference between a sensor voltage which is developed between a first pair of said electrodes and a reference voltage, between a second pair of said electrodes to maintain said sensor voltage at said reference voltage, said voltage applying means thereby producing, as an output which represents an oxygen concentration sensing value, a value of pump current which flows between said second pair of electrodes; a heater element for heating said solid electrolytic member; gas diffusion control means for providing an exhaust gas of an internal combustion engine to the vicinity of one electrode of each of said first and second pairs of electrodes; means for deriving an air/fuel ratio compensation value in accordance with said oxygen concentration sensing value, for controlling an air/fuel ratio of a mixture supplied to said internal combustion engine such as to maintain said air/fuel ratio at a target air/fuel ratio which is determined in accordance with engine operating conditions; drive means for driving an air/fuel ratio control means of said internal combustion engine in accordance with a corrected air/fuel ratio control value which is obtained by applying compensation to an air/fuel ratio control value in accordance with said air/fuel ratio compensation value; and means for detecting an abnormality of said heater element based upon a voltage developed between said first pair of electrodes and upon said air/fuel ratio compensation value.
Claim 3
Dependent Claim
54 words
An abnormality detection system according to claim 1, wherein, when a condition occurs in which a voltage developed between said first pair of electrodes is lower than a first predetermined value and said compensation value is lower than a second predetermined value, said condition is judged to indicate an abnormality of said heater element.
Claim 4
Dependent Claim
54 words
An abnormality detection system according to claim 1, wherein, when a condition occurs in which a voltage developed between said first pair of electrodes is higher than a first predetermined value and said compensation value is higher than a third predetermined value, said condition is judged to indicate an abnormality of said heater element.
References Cited (Backward Citations)
JPS5928046A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-15 | 1991-08-17 | 1992-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-15 | 1995-08-17 | 1996-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-15 | 1999-08-17 | 2000-02-16 | $7700.00 | Window Closed / Lapsed |