US4031747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Misfire monitor for engine analysis having automatic rescaling
Assignee: Rosemount Inc
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Filing: 1976-08-16
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Granted: 1977-06-28
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Expires: 1996-08-16
Abstract
Abstract An improvement to a misfire monitor sensing lean-roll in an internal combustion engine by comparing the rate of change in O 2 in the exhaust gases with respect to time against a limit is disclosed. In the preferred embodiment, the sensed O 2 level in the exhaust is used as an input to rescaling means which automatically normalizes the values used in the comparison to a standard range. Normalization is accomplished alternately by rescaling the rate of change value, rescaling the limit value used, or diluting the exhaust gases sampled to the level of a "standard" air blown engine to which the comparison limit is scaled.
Inventors
- 👤 John David Blanke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:49
CPC Classifications
G; G01; G01M; G01M15/00; G01M15/04; G01M15/10; G01M15/102; G01M15/104; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/406; G01N27/4065; G01N27/416; G01N27/417; G01N27/4175; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0062; G01N33/0067
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
143 words
In engine exhaust gas analysis apparatus having: means for sampling the exhaust gases including means for generating a first signal indicating the amount of a component present in the exhaust gases; differentiating means connected to said sampling means and including means responsive to said first signal for generating a second signal indicating the rate of change of said first signal with respect to time; means connected to said differentiating means for comparing said second signal to a limit; and, means connected to said comparing means for indicating when said second signal exceeds said limit, the improvement comprising: means for causing the values of said second signal and said limit to be normalized to a standard range before said comparing is done whereby the exceeding of said limit by said second signal will have substantially the same meaning regardless of the engine being analyzed.
Claim 2
Dependent Claim
143 words
In engine exhaust gas analysis apparatus having: means for sampling the exhaust gases including means for generating a first signal indicating the amount of a component present in the exhaust gases; differentiating means connected to said sampling means and including means responsive to said first signal for generating a second signal indicating the rate of change of said first signal with respect to time; means connected to said differentiating means for comparing said second signal to a limit; and, means connected to said comparing means for indicating when said second signal exceeds said limit, the improvement comprising: means for causing the values of said second signal and said limit to be normalized to a standard range before said comparing is done whereby the exceeding of said limit by said second signal will have substantially the same meaning regardless of the engine being analyzed.
Claim 3
Dependent Claim
20 words
Improved engine exhaust gas analysis apparatus as claimed in claim 1 wherein: said component in the exhaust gases is oxygen.
Claim 4
Dependent Claim
33 words
Improved engine exhaust gas analysis apparatus as claimed in claim 1 wherein said normalizing means comprises: said differentiating means including means for rescaling said second signal as a function of said first signal.
Claim 5
Dependent Claim
47 words
Improved engine exhaust gas analysis apparatus as claimed in claim 1 and comprising additionally: means for setting said limit connected to said comparing means; and, means for rescaling said limit as a function of said first signal connected between said sampling means and said limit setting means.
Claim 6
Dependent Claim
120 words
The improved method of detecting a lean-roll condition in an internal combustion engine comprising the steps of: (a) sampling the exhaust gases from the engine to produce a first signal indicative of the percent of oxygen contained therein; (b) differentiating said first signal to produce a second signal indicative of the time rate of change of said first signal; (c) normalizing the second signal value and a limit value to a standardized range representing a lean-roll condition; (d) comparing said second signal to said limit value such that if said second signal exceeds said limit value the engine is in a lean-roll condition; and, (e) activating means for indicating a lean-roll condition when said second signal exceeds said limit value.
Claim 7
Dependent Claim
120 words
The improved method of detecting a lean-roll condition in an internal combustion engine comprising the steps of: (a) sampling the exhaust gases from the engine to produce a first signal indicative of the percent of oxygen contained therein; (b) differentiating said first signal to produce a second signal indicative of the time rate of change of said first signal; (c) normalizing the second signal value and a limit value to a standardized range representing a lean-roll condition; (d) comparing said second signal to said limit value such that if said second signal exceeds said limit value the engine is in a lean-roll condition; and, (e) activating means for indicating a lean-roll condition when said second signal exceeds said limit value.
Claim 8
Dependent Claim
74 words
The method of claim 5 wherein said step of normalizing comprises the steps of: (a) determining the base level of said first signal when said second signal equals zero; and, (b) rescaling the value of said second signal as a function of said base level whereby a single limit value can be used in detecting lean-roll in engines having differing levels of time rate of change of said first signal during a lean-roll condition.
Claim 9
Dependent Claim
79 words
The method of claim 5 wherein said step of normalizing comprises the steps of: (a) determining the base level of said first signal when said second signal equals zero; and, (b) rescaling the value of said limit value as a function of said base level whereby a single amplification level can be used in producing said second signal when detecting lean-roll in engines having differing levels of time rate of change of said first signal during a lean-roll condition.
References Cited (Backward Citations)
US3969932A
Cited
US3938479A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |