US4170969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air fuel mixture control apparatus for internal combustion engines
Assignee: Nissan Motor Co Ltd
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Filing: 1977-07-25
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Granted: 1979-10-16
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Expires: 1997-07-25
Abstract
Abstract In a closed loop air fuel mixture control system in which an exhaust gas sensor is provided to control the mixture ratio, a detector is provided to detect an operating condition of the engine to change the control from the closed mode to an open control mode when the exhaust gas sensor begins to fail under the sensed operating condition.
Inventors
- 👤 Masaharu Asano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:48
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1486; F02D41/1488
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
199 words
Air fuel mixture apparatus for an internal combustion engine of an automotive vehicle, comprising: means for detecting a composition of exhaust gases from said engine and providing a composition representative signal; a control amplifier coupled to the exhaust composition detecting means to provide an error correction signal; means for detecting when the amplitude of the exhaust composition detecting means is at a high level and when said amplitude is at a lower level; means connected to said amplitude detecting means for measuring (1) a first period of time elapsed between transitions from the high level to the lower level and from the lower level to the high level and (2) a second period of time elapsed between transitions from the lower level to the high level and from the high level to the lower level; means for comparing said first and second measured elapsed time periods with a predetermined time duration; means responsive to said comparing means for disabling the control amplifier when either of said measured elapsed time periods is greater than said predetermined duration; and means responsive to the error correction signal for adjusting the mixture ratio of air to fuel to be supplied to said engine.
Claim 2
Dependent Claim
199 words
Air fuel mixture apparatus for an internal combustion engine of an automotive vehicle, comprising: means for detecting a composition of exhaust gases from said engine and providing a composition representative signal; a control amplifier coupled to the exhaust composition detecting means to provide an error correction signal; means for detecting when the amplitude of the exhaust composition detecting means is at a high level and when said amplitude is at a lower level; means connected to said amplitude detecting means for measuring (1) a first period of time elapsed between transitions from the high level to the lower level and from the lower level to the high level and (2) a second period of time elapsed between transitions from the lower level to the high level and from the high level to the lower level; means for comparing said first and second measured elapsed time periods with a predetermined time duration; means responsive to said comparing means for disabling the control amplifier when either of said measured elapsed time periods is greater than said predetermined duration; and means responsive to the error correction signal for adjusting the mixture ratio of air to fuel to be supplied to said engine.
Claim 3
Dependent Claim
126 words
Air-fuel mixture control apparatus as claimed in claim 1, wherein said amplitude detecting means comprises a bistable device operable to assume a first stable state in response to said amplitude being at a high level and a second stable state in response to said amplitude being at the lower level, and wherein said time measuring and detecting means comprises first means for counting clock pulses during the time when said bistable device is in the first stable state to provide an output when the counted clock pulses reach a first predetermined number and second means for counting clock pulses during the time when said bistable device is in the second stable state to provide an output when the counted clock pulses reach a second predetermined number.
Claim 4
Dependent Claim
21 words
Air fuel mixture control apparatus as claimed in claim 1, further comprising means for detecting the deceleration condition of the vehicle.
Claim 5
Dependent Claim
32 words
Air fuel mixture control apparatus as claimed in claim 1, further comprising means for detecting the temperature of said engine and providing an output when the temperature is below a predetermined value.
Claim 6
Dependent Claim
40 words
Air fuel mixture control apparatus as claimed in claim 1, wherein said interval detecting means comprises means for integrating the composition representative signal and a comparator coupled to the integrating means to compare the integrated signal with a predetermined value.
Claim 7
Dependent Claim
39 words
Air fuel mixture control apparatus as claimed in claim 1, further comprising means for detecting the idling condition of the vehicle, and wherein said disabling means is responsive to said idling condition detecting means to disable the control amplifier.
Claim 8
Dependent Claim
39 words
Air fuel mixture control apparatus as claimed in claim 6, further comprising timing circuit means coupled to the idling condition detecting means to disable the control amplifier at a delayed timing from the instant said idling condition is detected.
Claim 9
Dependent Claim
33 words
Air fuel mixture control apparatus as claimed in claim 7, further comprising means for maintaining the control amplifier under the disabling condition for a predetermined interval from the instant said idling condition terminates.
Claim 10
Dependent Claim
62 words
Air fuel mixture control apparatus as claimed in claim 6, further comprising timing circuit means coupled to the idling condition detecting means for disabling the control amplifier at a point in time delayed from the instant said idling condition is detected and for maintaining the control amplifier under the disabling condition for a predetermined interval from the instant said idling condition terminates.
Claim 11
Dependent Claim
81 words
Air fuel mixture control apparatus as claimed in claim 9, wherein said timing circuit means comprises means for integrating a voltage in response to the termination of the idling condition, means for comparing the integrated voltage with a predetermined value, and gating means for permitting the idling condition detecting means to disable the control amplifier when the integrated voltage is below the predetermined value and preventing same from disabling the control amplifier when the integrated voltage is above the predetermined value.
Claim 12
Dependent Claim
69 words
Air fuel mixture control apparatus as claimed in claim 10, wherein said integrating means is of an operational integrating circuit of a variable rate integration type, and wherein a coincidence circuit is connected between the output of the idling condition detecting means and the output of the gating means to provide a coincidence output, said coincidence output being connected to the integrating circuit to change its rate of integration.
Claim 13
Dependent Claim
37 words
Air fuel mixture control apparatus as claimed in claim 1, further comprising means responsive to the interval detecting means to maintain the gain of said control amplifier to a minimum level while said control amplifier is disabled.
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) | 1982-10-15 | 1983-04-16 | 1983-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-15 | 1987-04-16 | 1987-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-15 | 1991-04-16 | 1991-10-16 | $7700.00 | Window Closed / Lapsed |