US4748956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel control apparatus for an engine
Assignee: Mazda Motor Corp
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Filing: 1986-07-16
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Granted: 1988-06-07
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Expires: 2006-07-16
Abstract
Abstract The control of a quantity of supply fuel to allow the air-fuel ratio of a gas mixture to be a target air-fuel ratio is conducted by switching between an open loop control and a feedback control using an air-fuel ratio sensor, in response to an operating state of the engine. At the time of the feedback control, a learning correction is carried out using a learning value calculated on the basis of the feedback correction value. At the time of the open loop control, the quantity of the supply fuel is corrected in accordance with the feedback correction value and the learning value immediately before shifting from the feedback control to the open loop control.
Inventors
- 👤 Masato Iwaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:36
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/24; F02D41/2406; F02D41/2425; F02D41/2429; F02D41/2451; F02D41/2454; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
215 words
A fuel control apparatus for an engine for controlling an air-fuel ratio of a gas mixture to become a target air-fuel ratio by regulating a quantity of fuel supplied to the engine comprising: fuel supply means for supplying fuel to the engine, operating state detecting means for detecting the operating stsate of the engine, an air-fuel ratio sensor for detecting an air-fuel ratio in exhaust gas of the engine, open loop control means for controlling by an open loop control the supply fuel amount from said fuel supply means, feedback correcting means for feedback correcting the supply fuel amount from said fuel supply means by the feedback correction value calculated in accordance with an output from said air-fuel ratio sensor, learning control means for correcting the supply fuel amount by the learning value calculated according to the feedback correction value at the time of the feedback control, control switching means for switching between the open loop control and the feedback control in response to the operating state of the engine, and correcting means for correcting the fuel amount supplied from said fuel supply means at the time of the open loop control in accordance with the feedback correction value and the learning value immediately before switching from the feedback control to the open loop control.
Claim 2
Dependent Claim
215 words
A fuel control apparatus for an engine for controlling an air-fuel ratio of a gas mixture to become a target air-fuel ratio by regulating a quantity of fuel supplied to the engine comprising: fuel supply means for supplying fuel to the engine, operating state detecting means for detecting the operating stsate of the engine, an air-fuel ratio sensor for detecting an air-fuel ratio in exhaust gas of the engine, open loop control means for controlling by an open loop control the supply fuel amount from said fuel supply means, feedback correcting means for feedback correcting the supply fuel amount from said fuel supply means by the feedback correction value calculated in accordance with an output from said air-fuel ratio sensor, learning control means for correcting the supply fuel amount by the learning value calculated according to the feedback correction value at the time of the feedback control, control switching means for switching between the open loop control and the feedback control in response to the operating state of the engine, and correcting means for correcting the fuel amount supplied from said fuel supply means at the time of the open loop control in accordance with the feedback correction value and the learning value immediately before switching from the feedback control to the open loop control.
Claim 3
Dependent Claim
84 words
A fuel control apparatus according to claim 1, wherein said learning control means comprises: sampling means for sampling the feedback correction value at every predetermined time, learning value calculating means for calculating the learning value in accordance with a plurality of feedback correction values sampled by said sampling means, and learning value memory means for storing the learning value calculated by said learning value calculating means, thereby conducting the learning correction in accordance with the learning value stored in said learning value memory means.
Claim 4
Dependent Claim
54 words
A fuel control apparatus according to claim 2, wherein said learning value memory means comprises a plurality of learning zones divided in response to the operating states of the engine and stores the learning values calculated by said learning value calculating means in a learning zone corresponding to the operating state of the engine.
Claim 5
Dependent Claim
91 words
A fuel control apparatus according to claim 3, further comprising: discriminating means for discriminating whether one learning zone in said learning value memory is shifted to other learning zone or not in response to the operating state of the engine, and at-the-time-of-shifting initializing means for initializing the feedback correction value used for the feedback correction at the time of shifting learning zones as a value that is an addition of the feedback correction value before shifting to a deviation of the respective learning values between the one and other learning zones.
Claim 6
Dependent Claim
74 words
A fuel control apparatus according to claim 4, further comprising: learning value altering means for altering the learning value in accordance with predetermined conditions, and at-the-time-of-altering initializing means for initializing the feedback correction value used for the feedback correction at the time of altering the learning value as a value that is an addition of the feedback correction value before the alteration to a deviation of the learning values before and after the alteration.
Claim 7
Dependent Claim
77 words
A fuel control apparatus according to claim 1, further comprising: learning value altering means for altering the learning value in accordance with predetermined conditions, and at-the-time-of-altering initializing means for initializing the feedback correction value used for said feedback correction at the time of altering the learning value as a value that is an addition of the feedback correction value at the time of alteration to a deviation of the respective learning values before and after the alteration.
Claim 8
Dependent Claim
45 words
A fuel control apparatus according to claim 5 or 6, wherein the feedback correction value calculated in response to the output of said air-fuel ratio sensor is reduced with respect to a deviation from the target air-fuel ratio at every alteration of the learning values.
Claim 9
Dependent Claim
30 words
A fuel control apparatus according to one of claims 1 to 6, wherein the target air-fuel ratio when the feedback correction is conducted includes at least a stoichiometric air-fuel ratio.
Claim 10
Dependent Claim
51 words
A fuel control apparatus according to one of claim 1 to 6, wherein the fuel supply means is a fuel injection valve, and the regulation of the fuel injection amount from said fuel injection valve is conducted by the pulse width of a drive pulse supplied to the fuel injection valve.
Claim 11
Dependent Claim
44 words
A fuel control apparatus according to one of claim 1 to 6, wherein the operating states of the engine representing the switching conditions between the open loop control and the feedback control are set using the engine speed and the engine load as parameters.
Claim 12
Dependent Claim
28 words
A fuel control apparatus according to claim 10, wherein the operating state of the engine when the open loop control is conducted includes at least a decelerating range.
Claim 13
Dependent Claim
30 words
A fuel control apparatus according to claim 11, further comprising: inhibiting means for inhibiting the correction by said correction means in open loop control ranges other than the decelerating range.
Claim 14
Dependent Claim
42 words
A fuel control apparatus according to claim 5, wherein the alteration of the learning value by said learning value altering means is conducted at every predetermined time when the number of sampling the feedback correction values becomes a predetermined value or larger.
Claim 15
Dependent Claim
34 words
A fuel control apparatus according to claim 1, further comprising correction means for correcting the fuel amount relative to a value obtained by an addition of the feedback correction value to the learning value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |