US5507269A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air fuel ratio control apparatus for internal combustion engines
Assignee: Denso Corp
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Filing: 1995-07-12
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Granted: 1996-04-16
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Expires: 2015-07-12
Abstract
Abstract In a fuel vapor purge mechanism, the fuel vapor generated from a fuel tank and stored in a canister undergoes flow volume control with a purge solenoid valve while being introduced to an intake system of the engine via a purge passageway. Meanwhile, in an air/fuel ratio feedback control system, by means of a linear air/fuel ratio sensor mounted on an exhaust system of the engine, the air/fuel ratio of air-fuel mixture of fuel and intake air including the fuel vapor. If a change amount of a purge ratio the fuel vapor goes above a determined value, there is compensation of the air/fuel ratio compensation coefficient FAF concerned with the feedback control based on the change ratio.
Inventors
- 👤 Junya Morikawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:39
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1486; F02D41/1487; F02D41/0025; F02D41/003; F02D41/0042; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027; F02D41/1444; F02D41/1454; F02D41/1456
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
197 words
An air/fuel ratio control apparatus for internal combustion engines comprising: a fuel injection valve for injecting fuel supplied from a fuel tank into an engine; a canister storing therein fuel vapor generated in the fuel tank; a purge passage for leading the fuel vapor stored in the canister to an air intake portion of the engine; a flow control valve disposed in the purge passage for controlling a flow amount of the fuel vapor led through the purge passage in accordance with an intake air amount of the engine; an air/fuel ratio sensor disposed in an exhaust portion of the engine for detecting, from an exhaust gas of the engine, an air/fuel ratio of mixture of air and fuel including the fuel vapor supplied to the engine; feedback control means for controlling, in accordance with the detected air/fuel ratio, an amount of the fuel injected from the fuel injection valve thereby to control the air/fuel ratio of the mixture to a target value; and compensation means for compensating, by a change amount of ratio of the flow amount of the fuel vapor relative to the intake air amount, a compensation coefficient used in the feedback control means.
Claim 2
Dependent Claim
197 words
An air/fuel ratio control apparatus for internal combustion engines comprising: a fuel injection valve for injecting fuel supplied from a fuel tank into an engine; a canister storing therein fuel vapor generated in the fuel tank; a purge passage for leading the fuel vapor stored in the canister to an air intake portion of the engine; a flow control valve disposed in the purge passage for controlling a flow amount of the fuel vapor led through the purge passage in accordance with an intake air amount of the engine; an air/fuel ratio sensor disposed in an exhaust portion of the engine for detecting, from an exhaust gas of the engine, an air/fuel ratio of mixture of air and fuel including the fuel vapor supplied to the engine; feedback control means for controlling, in accordance with the detected air/fuel ratio, an amount of the fuel injected from the fuel injection valve thereby to control the air/fuel ratio of the mixture to a target value; and compensation means for compensating, by a change amount of ratio of the flow amount of the fuel vapor relative to the intake air amount, a compensation coefficient used in the feedback control means.
Claim 3
Dependent Claim
32 words
An air/fuel ratio control apparatus according to claim 1, wherein: said compensation means compensates the compensation coefficient when the change amount of the ratio of the flow amount exceeds a predetermined value.
Claim 4
Dependent Claim
40 words
An air/fuel ratio control apparatus according to claim 1, wherein: said compensation means compensates the compensation coefficient when a change amount of the compensation coefficient corresponding to a change in the ratio of the flow amount exceeds a predetermined value.
Claim 5
Dependent Claim
93 words
An air/fuel ratio control apparatus according to claim 3, wherein: said compensation means determines a present value of a compensation value ΔFAFi as ΔFAFi=(PGRi/PGRi-1)×ΔFAFi-1, with i, PGRi-1, PGRi and ΔFAFi-1 being defined as a number of compensations, a value of the ratio of the fuel vapor flow amount at the time of a previous compensation, a value of the ratio of the fuel flow amount for a current compensation and a previous value of the change amount of the compensation coefficient corresponding to the change in the ratio of the flow amount, respectively.
Claim 6
Dependent Claim
24 words
An air/fuel ratio control apparatus according to claim 4, wherein: said compensation means compensates the correction coefficient after averaging the determined compensation value ΔFAFi.
Claim 7
Dependent Claim
39 words
An air/fuel ratio control apparatus according to claim 5, wherein: said compensation means determines a current value of the compensation coefficient FAF as FAF=FAFi-1-(ΔFAFi-1-ΔFAFi)/2, with ΔFAFi-1 being defined as the compensation coefficient at the time of a previous compensation.
References Cited (Backward Citations)
JPS61129454A
Cited
JPS6341632A
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EP0312835A2
Cited
US5048493A
Cited
US5216997A
Cited
JPH05288107A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-16 | 1999-10-16 | 2000-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-16 | 2003-10-16 | 2004-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-16 | 2007-10-16 | 2008-04-16 | $7700.00 | Window Closed / Lapsed |