US5228336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Engine intake air volume detection apparatus
Assignee: Nissan Motor Co Ltd
•
Filing: 1992-01-14
•
Granted: 1993-07-20
•
Expires: 2012-01-14
Abstract
Abstract This invention concerns an apparatus for detecting a cylinder intake air volume based on the output of an air flow meter installed in an intake manifold. The apparatus determines a weighting average coefficient from predetermined calculation equations, and calculates the weighted average of the output of the air flow meter based on this weighting average coefficient so as to detect the actual cylinder air intake volume. Since the weighting average coefficient is determined from calculation equations and not from a map, the detection of the cylinder intake air volume is simple and precise irrespective of the type of engine. When applied to AFR control systems of an engine, it is preferable to correct the weighted average based on a variation rate of the weighted average when the engine is not running under predetermined high load conditions. AFR control can therefore be performed with accurate timing.
Inventors
- 👤 Hatsuo Nagaishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:04
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/18; F02D41/182; G; G01; G01F; G01F1/00; G01F1/68; G01F1/72
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
184 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating a weighting average coefficient Fload based on the equation: Fload=1/{(120·Vm/(Ve·η·Ne·Δt)+1} wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed, and means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, and means for outputting the value calculated by said weighted average volume calculating means as an actual cylinder intake air volume per engine revolution.
Claim 2
Dependent Claim
184 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating a weighting average coefficient Fload based on the equation: Fload=1/{(120·Vm/(Ve·η·Ne·Δt)+1} wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed, and means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, and means for outputting the value calculated by said weighted average volume calculating means as an actual cylinder intake air volume per engine revolution.
Claim 3
Dependent Claim
283 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating a weighting average coefficient Fload based on the equation: Fload=1/{(120·Vm/(Ve·η·Ne·Δt)+1} wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed, and means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, means for correcting the value calculated by said weighted average volume calculating means based on a difference between this value and the value calculated in the immediately preceding calculation cycle, means for detecting engine load, means for judging whether or not the detected engine load is a high load equal to or above a predetermined constant, and means for outputting the value calculated by said weighted average volume calculating means as an actual cylinder intake air volume per engine revolution if it is judged that the engine load is high load, and for outputting the value corrected by said correcting means as the actual cylinder intake air volume per engine revolution if it is judged that the engine load is not high load.
Claim 4
Dependent Claim
283 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating a weighting average coefficient Fload based on the equation: Fload=1/{(120·Vm/(Ve·η·Ne·Δt)+1} wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed, and means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, means for correcting the value calculated by said weighted average volume calculating means based on a difference between this value and the value calculated in the immediately preceding calculation cycle, means for detecting engine load, means for judging whether or not the detected engine load is a high load equal to or above a predetermined constant, and means for outputting the value calculated by said weighted average volume calculating means as an actual cylinder intake air volume per engine revolution if it is judged that the engine load is high load, and for outputting the value corrected by said correcting means as the actual cylinder intake air volume per engine revolution if it is judged that the engine load is not high load.
Claim 5
Dependent Claim
316 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating a weighting average coefficient Fload based on the equation: Fload=1/{(120·Vm/(Ve·η·Ne·Δt)+1} wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed, and means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, means for correcting the value calculated by said weighted average volume calculating means based on a difference between this value and the value calculated in the immediately preceding calculation cycle, means for detecting engine load, means for judging whether or not the detected engine load is a high load equal to or above a predetermined constant, means for comparing the value calculated by said weighted average volume calculating means and the cylinder intake air volume per engine revolution, and means for outputting the value calculated by said weighted average value calculating means as the actual intake air volume per engine revolution if it is judged that the engine load is high load and that the value calculated by said weighted average value calculating means is greater than the intake air volume per engine revolution, and outputting the value corrected by said correcting means as the actual intake air volume per engine revolution in all other cases.
Claim 6
Dependent Claim
316 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating a weighting average coefficient Fload based on the equation: Fload=1/{(120·Vm/(Ve·η·Ne·Δt)+1} wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed, and means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, means for correcting the value calculated by said weighted average volume calculating means based on a difference between this value and the value calculated in the immediately preceding calculation cycle, means for detecting engine load, means for judging whether or not the detected engine load is a high load equal to or above a predetermined constant, means for comparing the value calculated by said weighted average volume calculating means and the cylinder intake air volume per engine revolution, and means for outputting the value calculated by said weighted average value calculating means as the actual intake air volume per engine revolution if it is judged that the engine load is high load and that the value calculated by said weighted average value calculating means is greater than the intake air volume per engine revolution, and outputting the value corrected by said correcting means as the actual intake air volume per engine revolution in all other cases.
Claim 7
Dependent Claim
183 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating the weighting average coefficient Fload based on the equation: Fload=(Ve·η·Ne·Δt)/(120·Vm) wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, and means for outputting the value calculated by said weighted average volume calculating means as an actual cylinder intake air volume per engine revolution.
Claim 8
Dependent Claim
183 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating the weighting average coefficient Fload based on the equation: Fload=(Ve·η·Ne·Δt)/(120·Vm) wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, and means for outputting the value calculated by said weighted average volume calculating means as an actual cylinder intake air volume per engine revolution.
Claim 9
Dependent Claim
282 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating the weighting average coefficient Fload based on the equation: Fload=(Ve·η·Ne·Δt)/(120·Vm) wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, means for correcting the value calculated by said weighted average volume calculating means based on a difference between this value and the value calculated in the immediately preceding calculation cycle, means for detecting engine load, means for judging whether or not the detected engine load is a high load equal to or above a predetermined constant, and means for outputting the value calculated by said weighted average volume calculating means as the actual cylinder intake air volume per engine revolution if it is judged that the engine load is high load, and for outputting the value corrected by said correcting means as the actual cylinder intake air volume per engine revolution if it is judged that the engine load is not high load.
Claim 10
Dependent Claim
282 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating the weighting average coefficient Fload based on the equation: Fload=(Ve·η·Ne·Δt)/(120·Vm) wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, means for correcting the value calculated by said weighted average volume calculating means based on a difference between this value and the value calculated in the immediately preceding calculation cycle, means for detecting engine load, means for judging whether or not the detected engine load is a high load equal to or above a predetermined constant, and means for outputting the value calculated by said weighted average volume calculating means as the actual cylinder intake air volume per engine revolution if it is judged that the engine load is high load, and for outputting the value corrected by said correcting means as the actual cylinder intake air volume per engine revolution if it is judged that the engine load is not high load.
Claim 11
Dependent Claim
315 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating the weighting average coefficient Fload based on the equation: Fload=(Ve·η·Ne·Δt)/(120·Vm) wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, means for correcting the value calculated by said weighted average volume calculating means based on a difference between this value and the value calculated in the immediately preceding calculation cycle, means for detecting engine load, means for judging whether or not the detected engine load is a high load equal to or above a predetermined constant, means for comparing the value calculated by said weighted average volume calculating means and the cylinder intake air volume per engine revolution, and means for outputting the value calculated by said weighted average value calculating means as the actual intake air volume per engine revolution if it is judged that the engine load is high load and that the value calculated by said weighted average value calculating means is greater than the intake air volume per engine revolution, and outputting the value corrected by said correcting means as the actual intake air volume per engine revolution in all other cases.
Claim 12
Dependent Claim
315 words
An intake air volume detection apparatus for an engine provided with a cylinder, an intake manifold for guiding air into the cylinder and a throttle valve installed in said intake manifold for regulating an intake air volume in said cylinder, said apparatus comprising: an air flow meter installed upstream of the throttle valve in said intake manifold for detecting an air flowrate in said intake manifold, means for calculating the cylinder intake air volume per engine revolution at a predetermined interval from the air flowrate detected by said air flow meter, means for calculating the weighting average coefficient Fload based on the equation: Fload=(Ve·η·Ne·Δt)/(120·Vm) wherein: Δt=calculation interval of air volume supplied to cylinder Vm=capacity of intake manifold Ve=engine displacement η=new air proportion in cylinder Ne=engine speed means for calculating a weighted average volume based on the intake air volume per engine revolution, the weighting average coefficient Fload and the weighted average volume calculated in the immediately preceding calculation cycle, means for correcting the value calculated by said weighted average volume calculating means based on a difference between this value and the value calculated in the immediately preceding calculation cycle, means for detecting engine load, means for judging whether or not the detected engine load is a high load equal to or above a predetermined constant, means for comparing the value calculated by said weighted average volume calculating means and the cylinder intake air volume per engine revolution, and means for outputting the value calculated by said weighted average value calculating means as the actual intake air volume per engine revolution if it is judged that the engine load is high load and that the value calculated by said weighted average value calculating means is greater than the intake air volume per engine revolution, and outputting the value corrected by said correcting means as the actual intake air volume per engine revolution in all other cases.
References Cited (Backward Citations)
US4873641A
Cited
JPH03111639A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-19 | 1997-01-18 | 1997-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-19 | 2001-01-18 | 2001-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-19 | 2005-01-18 | 2005-07-20 | $7700.00 | Window Closed / Lapsed |