Patent US4765305A successfully refreshed from Google Patents.
US4765305A
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US
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Control method of controlling an air/fuel ratio control system in an internal combustion engine
Assignee: Honda Motor Co Ltd
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Filing: 1987-01-12
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Granted: 1988-08-23
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Expires: 2007-01-12
Abstract
Abstract In a method for determining a control parameter of an air/fuel ratio control system of an internal combustion engine by means of an oxygen concentration sensor disposed in an exhaust system of the engine, the control parameter of the air/fuel ratio is determined independently of the output signal of the oxygen concentration sensor when a light load operation of the engine continued for more than a predetermined time period is detected.
Inventors
- 👤 Yoshitaka Hibino
- 👤 Takeshi Fukuzawa
- 👤 Atsushi Totsune
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:58
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1477; F02D41/1481; F02D41/1486; F02D41/1488; F02D41/1489; F02D41/1444; F02D41/1454; F02D41/1456
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
232 words
A control method for controlling an air/fuel ratio control system in an internal combustion engine comprising the steps of: setting a base air/fuel ratio control value in accordance with parameters of the engine operation relating to the load on the engine; setting an operational air/fuel ratio control value corresponding to a target air/fuel ratio by correcting a set value of said base value in response to an output signal of an oxygen concentration sensor disposed in an exhaust gas passage of said internal combustion engine; controlling the air/fuel ratio of the mixture to be supplied to said internal combustion engine according to said operational air/fuel ratio control value; setting a correction value indicative of an error caused by the lapse of time due to deterioration of said oxygen concentration sensor or the carburetor of said internal combustion engine; detecting continuation of a light load operation of said internal combustion engine for more than a predetermined time period; and selecting, as the air/fuel ratio control value, an open loop control value by which said air/fuel ratio of the mixture can be controlled around said target air/fuel ratio in accordance with said set base value and said set correction value irrespectively of said output signal of said oxygen concentration sensor during a time period in which said light load operation continues after the continuation of said light load operation detected by said detecting step.
Claim 2
Dependent Claim
232 words
A control method for controlling an air/fuel ratio control system in an internal combustion engine comprising the steps of: setting a base air/fuel ratio control value in accordance with parameters of the engine operation relating to the load on the engine; setting an operational air/fuel ratio control value corresponding to a target air/fuel ratio by correcting a set value of said base value in response to an output signal of an oxygen concentration sensor disposed in an exhaust gas passage of said internal combustion engine; controlling the air/fuel ratio of the mixture to be supplied to said internal combustion engine according to said operational air/fuel ratio control value; setting a correction value indicative of an error caused by the lapse of time due to deterioration of said oxygen concentration sensor or the carburetor of said internal combustion engine; detecting continuation of a light load operation of said internal combustion engine for more than a predetermined time period; and selecting, as the air/fuel ratio control value, an open loop control value by which said air/fuel ratio of the mixture can be controlled around said target air/fuel ratio in accordance with said set base value and said set correction value irrespectively of said output signal of said oxygen concentration sensor during a time period in which said light load operation continues after the continuation of said light load operation detected by said detecting step.
Claim 3
Dependent Claim
30 words
A control method as claimed in claim 1, wherein said oxygen concentration sensor has an output signal characteristic which is degraded as the temperature of said oxygen concentration sensor lowers.
Claim 4
Dependent Claim
24 words
A control method as set forth in claim 1, wherein said open loop control value varies gradually in accordance with the lapse of time.
Claim 5
Dependent Claim
65 words
A control method as set forth in claim 3, wherein said step of selecting said open loop control value comprises calculating a coefficient indicative of said error generating a correction value of said base value which is function of said coefficient indicative of said error, and generating said open loop control value in proportion to a multiplication of said base value and said correction value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |