US4699107A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Engine dilution control by combustion pressure harmonic amplitude ratio
Assignee: Motors Liquidation Co
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Filing: 1986-11-17
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Granted: 1987-10-13
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Expires: 2006-11-17
Abstract
Abstract A charge dilution control for an internal combustion engine subjects a combustion pressure signal to multiple switched capacitor bandpass filters with frequencies controlled in phase lock loop from engine speed to generate harmonic wave signals at frequencies which are constant multiples of the varying firing frequency. The amplitude ratio between the peaks of two harmonics, with one preferably the fundamental firing frequency, is used to control charge dilution apparatus such as EGR or variable valve lift to maintain a predetermined ratio. The harmonic compared to the fundamental may be a higher harmonic or a subharmonic. Ignition timing for the engine may be controlled to maintain a phase difference of zero between two of the higher harmonics such as the second and fourth.
Inventors
- 👤 Edward J. Jensen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:35
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1497; F02D41/1498; F02P; F02P5/00; F02P5/04; F02P5/045; F02D41/1401; F02D2041/1413; F02D2041/1432; F02D2200/00; F02D2200/02; F02D2200/10; F02D2200/1015; F02D41/0097
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
171 words
A charge dilution control for an internal combustion engine including a combustion chamber, means effective to ignite a combustible charge in the combustion chamber and apparatus effective to control the admission of dilution gases to the combustible charge, the charge dilution control comprising, in combination: pressure sensing means effective to sense the pressure in the combustion chamber and generate a combustion pressure signal therefrom; means effective to sense the rotational speed of the crankshaft; frequency selective filter means for generating at least two predetermined harmonic signals of the combustion pressure signal, the frequency selective filter means being responsive to the last means to maintain the frequencies of the harmonic signals proportional to the firing frequency of the engine as the rotational speed of the crankshaft changes; means effective to detect the relative peak amplitudes of corresponding peaks in the two predetermined harmonic signals and determine the ratio thereof; and means effective to vary the dilution control apparatus to maintain the ratio at or below a predetermined level in closed loop operation.
Claim 2
Dependent Claim
171 words
A charge dilution control for an internal combustion engine including a combustion chamber, means effective to ignite a combustible charge in the combustion chamber and apparatus effective to control the admission of dilution gases to the combustible charge, the charge dilution control comprising, in combination: pressure sensing means effective to sense the pressure in the combustion chamber and generate a combustion pressure signal therefrom; means effective to sense the rotational speed of the crankshaft; frequency selective filter means for generating at least two predetermined harmonic signals of the combustion pressure signal, the frequency selective filter means being responsive to the last means to maintain the frequencies of the harmonic signals proportional to the firing frequency of the engine as the rotational speed of the crankshaft changes; means effective to detect the relative peak amplitudes of corresponding peaks in the two predetermined harmonic signals and determine the ratio thereof; and means effective to vary the dilution control apparatus to maintain the ratio at or below a predetermined level in closed loop operation.
Claim 3
Dependent Claim
43 words
The charge dilution control of claim 1 wherein one of the harmonic signals is the fundamental at the firing frequency of the engine and dilution is increased if the ratio of the other harmonic to the fundamental is greater than a predetermined reference.
Claim 4
Dependent Claim
26 words
The charge dilution control of claim 2 wherein the other harmonic signal is a higher harmonic at a whole number multiple of the engine firing frequency.
Claim 5
Dependent Claim
22 words
The charge dilution control of claim 2 wherein the other harmonic signal is the fourth harmonic, at four times the firing frequency.
Claim 6
Dependent Claim
47 words
The charge dilution control of claim 1 wherein the engine has a plurality of combustion chambers and the other harmonic signal is a subharmonic at a frequency lower than the engine firing frequency and related to the firing frequency of an individual combustion chamber of the engine.
Claim 7
Dependent Claim
113 words
The charge dilution control of claim 1 in which: the means effective to sense the rotational speed of the crankshaft comprises frequency multiplying means for generating a pulsating signal at a frequency proportional to the rotational speed of the crankshaft; the frequency selective filter means comprises a plurality of switched capacitor filters clocked by the pulsating signal to maintain narrow passbands at whole number multiples of the engine firing frequency and generating from the combustion pressure signal sine and cosine wave harmonics thereof; and the means effective to detect the times of corresponding peaks uses the zero crossing of the cosine wave harmonic to identify the peak of the corresponding sine wave harmonic.
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) | 1990-10-12 | 1991-04-13 | 1991-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-12 | 1995-04-13 | 1995-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-12 | 1999-04-13 | 1999-10-13 | $7700.00 | Window Closed / Lapsed |