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US4760822A
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Method for controlling the air/fuel ratio of an internal combustion engine with a fuel cut operation
Assignee: Honda Motor Co Ltd
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Filing: 1986-12-24
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Granted: 1988-08-02
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Expires: 2006-12-24
Abstract
Abstract A method for controlling an air/fuel ratio of an internal combustion engine. The fuel supply is performed normally by a feedback control operation for controlling the air/fuel ratio of the mixture toward a target air/fuel ratio in accordance with an oxygen concentration in an exhaust gas of the engine. A fuel cut operation under a predetermined condition includes a step for detecting a transition from the fuel cut operation to resume the fuel supply, and a step for shifting, for a time period after a detection of the transition, the target air/fuel ratio of the feedback control to a lean side with respect to a target air/fuel ratio value to be used after the elapse of the time period.
Inventors
- 👤 Toshiyuki Mieno
- 👤 Toyohei Nakajima
- 👤 Yasushi Okada
- 👤 Nobuyuki Oono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:16
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/04; F02D41/12; F02D41/123; F02D41/126
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
147 words
A method for controlling an air/fuel ratio of an internal combustion engine having an air/fuel ratio control system for controlling a mixture to be supplied to said engine, comprising: normally operating said air/fuel ratio control system by controlling an air/fuel ratio of said mixture by a feedback control operation toward a target air/fuel ratio in accordance with an oxygen concentration in an exhaust gas of said engine; placing said air/fuel ratio control system in a fuel cut mode when a condition for a fuel cut operation is satisfied; and resuming operation of said air/fuel ratio control system by performing said feedback control operation while controlling said target air/fuel ratio, for a predetermined time period after said fuel cut operation is terminated and said fuel supply is resumed, to be larger than a target air/fuel ratio value to be used after an elapse of said predetermined time period.
Claim 2
Independent Claim
147 words
A method for controlling an air/fuel ratio of an internal combustion engine having an air/fuel ratio control system for controlling a mixture to be supplied to said engine, comprising: normally operating said air/fuel ratio control system by controlling an air/fuel ratio of said mixture by a feedback control operation toward a target air/fuel ratio in accordance with an oxygen concentration in an exhaust gas of said engine; placing said air/fuel ratio control system in a fuel cut mode when a condition for a fuel cut operation is satisfied; and resuming operation of said air/fuel ratio control system by performing said feedback control operation while controlling said target air/fuel ratio, for a predetermined time period after said fuel cut operation is terminated and said fuel supply is resumed, to be larger than a target air/fuel ratio value to be used after an elapse of said predetermined time period.
Claim 3
Independent Claim
178 words
A method for controlling an air/fuel ratio of an internal combustion engine having an air/fuel ratio control system for controlling a mixture to be supplied to said engine, comprising: normally operating said air/fuel ratio control system by controlling an air/fuel ratio of said mixture by a feedback control operation toward a target air/fuel ratio in accordance with an oxygen concentration in an exhaust gas of said engine; placing said air/fuel ratio control system in a fuel cut mode when a condition for a fuel cut operation is satisfied; detecting at least one parameter of engine operation when said air/fuel ratio control system is in the fuel cut mode; calculating a delay time period based on said parameter of engine operation; and resuming operation of said air/fuel ratio control system by performing said feedback control operation while controlling said target air/fuel ratio, for said delay time period after said fuel cut mode is terminated and fuel supply is resumed, to be larger than a target air/fuel ratio value to be used after an elapse of said predetermined time period.
Claim 4
Independent Claim
178 words
A method for controlling an air/fuel ratio of an internal combustion engine having an air/fuel ratio control system for controlling a mixture to be supplied to said engine, comprising: normally operating said air/fuel ratio control system by controlling an air/fuel ratio of said mixture by a feedback control operation toward a target air/fuel ratio in accordance with an oxygen concentration in an exhaust gas of said engine; placing said air/fuel ratio control system in a fuel cut mode when a condition for a fuel cut operation is satisfied; detecting at least one parameter of engine operation when said air/fuel ratio control system is in the fuel cut mode; calculating a delay time period based on said parameter of engine operation; and resuming operation of said air/fuel ratio control system by performing said feedback control operation while controlling said target air/fuel ratio, for said delay time period after said fuel cut mode is terminated and fuel supply is resumed, to be larger than a target air/fuel ratio value to be used after an elapse of said predetermined time period.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein said fuel cut mode substantially stops the fuel supplied said engine.
Claim 6
Dependent Claim
17 words
The method of claim 2 wherein said fuel cut mode substantially stops the fuel supplied said engine.
Claim 7
Dependent Claim
33 words
The method of claim 1 wherein said step of resuming operation by controlling said target air/fuel ratio is performed by multiplying said target air/fuel ratio by a constant K of greater than 1.
Claim 8
Dependent Claim
33 words
The method of claim 2 wherein said step of resuming operation by controlling said target air/fuel ratio is performed by multiplying said target air/fuel ratio by a constant K of greater than 1.
Claim 9
Dependent Claim
140 words
In an air/fuel ratio control system, employing an oxygen sensor, for controlling the mixture of an air/fuel ratio supplied to an internal combustion engine, said air/fuel ratio control system normally operating in a feedback mode wherein said air/fuel ratio is controlled toward a target air fuel ratio and operating in a fuel cut mode when predetermined conditions are satisfied, a method for controlling the air/fuel ratio after termination of a fuel cut mode of said control system comprising: detecting completion of said fuel cut mode and resumption of the fuel supply to said engine; and increasing said target air/fuel ratio for a predetermined period of time after detection of the completion of said fuel cut mode by said step of detecting to correct a temporary rich mixture condition occuring after operation of said control system in said fuel cut mode.
Claim 10
Dependent Claim
140 words
In an air/fuel ratio control system, employing an oxygen sensor, for controlling the mixture of an air/fuel ratio supplied to an internal combustion engine, said air/fuel ratio control system normally operating in a feedback mode wherein said air/fuel ratio is controlled toward a target air fuel ratio and operating in a fuel cut mode when predetermined conditions are satisfied, a method for controlling the air/fuel ratio after termination of a fuel cut mode of said control system comprising: detecting completion of said fuel cut mode and resumption of the fuel supply to said engine; and increasing said target air/fuel ratio for a predetermined period of time after detection of the completion of said fuel cut mode by said step of detecting to correct a temporary rich mixture condition occuring after operation of said control system in said fuel cut mode.
Claim 11
Dependent Claim
17 words
The method of claim 7 wherein said fuel cut mode substantially stops the fuel supplied said engine.
Claim 12
Dependent Claim
33 words
The method of claim 7 wherein said step of increasing said target air/fuel ratio for a predetermined time is performed by multiplying said target air/fuel ratio by a constant K greater than 1.
Claim 13
Dependent Claim
36 words
The method of claim 7 further comprising: detecting at least one parameter of engine operation when said engine is in said fuel cut mode; and calculating said predetermined period based on said parameter of engine operation.
References Cited (Backward Citations)
US4186691A
Cited
US4355618A
Cited
JPS58214626A
Cited
JPS58222928A
Cited
US4648370A
Cited
US4697567A
Cited
US4697559A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |