Patent US4452211A successfully refreshed from Google Patents.
US4452211A
Expired / Lapsed
US
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Air-fuel ratio control apparatus
Assignee: Mazda Motor Corp
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Filing: 1983-04-06
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Granted: 1984-06-05
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Expires: 2003-04-06
Abstract
Abstract An air-fuel control apparatus is disclosed in which an error in the air-fuel ratio is corrected in a manner such that feedback control is performed at least once for a predetermined period during a high engine load operation mode, and such that operation in the high engine load mode is thereafter effected by open-loop control on the basis of results generated during feedback control.
Inventors
- 👤 Seiji Wataya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:18
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/24; F02D41/2406; F02D41/2425; F02D41/2429; F02D41/2451; F02D41/2454; F02D41/2441; F02D41/2445
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
245 words
In an air-fuel ratio control apparatus for an internal combustion engine of a type including an exhaust component detector; means for detecting a high-load operating state of said internal combustion engine; a fuel flow control valve; a feedback circuit receiving inputs from said exhaust component detector and said high-load operating state detecting means; an open-loop control circuit comprising memory means for storing an output of said feedback circuit; control circuit means for producing on an output thereof a constant open-loop control signal at a level determined in accordance with an output of said memory means; and switch means operating in response to said output of said means for detecting said high-load state for coupling an output of said feedback circuit to operate said fuel flow control valve in a normal operating state and coupling an output of said open-loop control circuit to operate said fuel flow control valve in said high-load state, wherein the improvement comprises: means for delaying said output of said means for detecting said high-load state upon said output of said means for detecting said high-load state making a transition from a level corresponding to said normal state to a level corresponding to said high-load state, whereby said open-loop control circuit operates said fuel flow control valve in said high-load state in accordance with an output value of said feedback circuit produced in said high-load state such that errors in an air-fuel ration of said engine are minimized in said high-load state.
Claim 2
Dependent Claim
245 words
In an air-fuel ratio control apparatus for an internal combustion engine of a type including an exhaust component detector; means for detecting a high-load operating state of said internal combustion engine; a fuel flow control valve; a feedback circuit receiving inputs from said exhaust component detector and said high-load operating state detecting means; an open-loop control circuit comprising memory means for storing an output of said feedback circuit; control circuit means for producing on an output thereof a constant open-loop control signal at a level determined in accordance with an output of said memory means; and switch means operating in response to said output of said means for detecting said high-load state for coupling an output of said feedback circuit to operate said fuel flow control valve in a normal operating state and coupling an output of said open-loop control circuit to operate said fuel flow control valve in said high-load state, wherein the improvement comprises: means for delaying said output of said means for detecting said high-load state upon said output of said means for detecting said high-load state making a transition from a level corresponding to said normal state to a level corresponding to said high-load state, whereby said open-loop control circuit operates said fuel flow control valve in said high-load state in accordance with an output value of said feedback circuit produced in said high-load state such that errors in an air-fuel ration of said engine are minimized in said high-load state.
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) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |