US4361124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for controlling air-fuel ratio
Assignee: Subaru Corp
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Filing: 1980-08-01
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Granted: 1982-11-30
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Expires: 2000-08-01
Abstract
Abstract An electronic control system for controlling the air-fuel ratio for an internal combustion engine comprising an on-off type electromagnetic valve for correcting the air-fuel ratio of the air-fuel mixture supplied by an air-fuel mixture supply device, a comparing circuit for comparing the output signal of a detector with a reference value, an integration circuit connected to the comparing circuit, a pulse generator, and a comparator for producing pulses for driving the on-off type electromagnetic valve from output signals of the integration circuit and of the pulse generator for controlling the air-fuel ratio to a value substantially equal to the stoichiometric air-fuel ratio. A first converter converts the operation of the throttle valve to an electric quantity output, a second converter converts the prevailing ambient atmospheric pressure to another electric quantity output. Further, there is provided switches actuated by the output signals of the first converter for rendering the integration circuit non-responsive to the output of the detector and responsive to the output of the second converter.
Inventors
- 👤 Hiroyuki Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:39
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1486; F02D41/1488; F02D41/149
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
220 words
In a system for controlling the air-fuel ratio for an internal combustion engine having an induction passage, air-fuel mixture supply means, a throttle valve in the induction passage, an exhaust passage communicating with the engine, detecting means for detecting the concentration of a constituent of exhaust gases passing through said exhaust passage, an electronic control circuit operatively connected to an output of said detecting means and electromagnetic valve means actuated by an output signal from said electronic control circuit for correcting the air-fuel ratio of the air-fuel mixture supplied by said air-fuel mixture supply means dependent on said detecting means, the improvement comprising first converting means for converting the a condition in the induction passage to an electric quantity first output signal, second converting means for converting a presently existing ambient atmospheric pressure at an altitude of the engine to a corresponding electric quantity second output signal, first means dependent on the first output signal of said first converting means for rendering said electronic control circuit non-responsive to an output from said detecting means, second means dependent on the first output signal of said first converting means for feeding said second output signal of said second converting means to said electronic control circuit for controlling the air-fuel ratio to a proper value in dependency on the altitude of the engine.
Claim 2
Dependent Claim
220 words
In a system for controlling the air-fuel ratio for an internal combustion engine having an induction passage, air-fuel mixture supply means, a throttle valve in the induction passage, an exhaust passage communicating with the engine, detecting means for detecting the concentration of a constituent of exhaust gases passing through said exhaust passage, an electronic control circuit operatively connected to an output of said detecting means and electromagnetic valve means actuated by an output signal from said electronic control circuit for correcting the air-fuel ratio of the air-fuel mixture supplied by said air-fuel mixture supply means dependent on said detecting means, the improvement comprising first converting means for converting the a condition in the induction passage to an electric quantity first output signal, second converting means for converting a presently existing ambient atmospheric pressure at an altitude of the engine to a corresponding electric quantity second output signal, first means dependent on the first output signal of said first converting means for rendering said electronic control circuit non-responsive to an output from said detecting means, second means dependent on the first output signal of said first converting means for feeding said second output signal of said second converting means to said electronic control circuit for controlling the air-fuel ratio to a proper value in dependency on the altitude of the engine.
Claim 3
Dependent Claim
18 words
The system according to claim 1 wherein said electromagnetic valve means is an on-off type electromagnetic valve means.
Claim 4
Dependent Claim
29 words
The system as set forth in claim 1, wherein said first converting means is a means for converting the operation of the throttle valve into said first output signal.
Claim 5
Dependent Claim
114 words
The system as set forth in claim 1, further wherein said first means includes a first switch means for connecting said output of said detecting means to said electronic control circuit, said first switch means has a first gate means for being operatively controlled by the first output signal of said first converting means, said second means for feeding said second output signal of said second converting means to said electronic control circuit includes a second switch means operatively connecting an output of second converting means to said electronic control circuit, said second switch means having a second gate means for being operatively controlled by the first output signal of said first converting means.
Claim 6
Dependent Claim
86 words
The system as set forth in claim 2 or 4, wherein said first means is for rendering said electronic control circuit non-responsive to the output signal from said detecting means when said first converting means detects an idling and heavy load operation condition, respectively, in the induction passage, said second means is for feeding said second output signal of said second converting means to said electronic control circuit when said first converting means detects the idling and heavy load operation condition, respectively, in the induction passage.
Claim 7
Dependent Claim
78 words
The system as set forth in claim 5, wherein said first means is for rendering said electronic control circuit responsive to the output signal from said detecting means when said first converting means detects a partial load operation condition in the induction passage, said second means is for disconnecting said second output signal of said second converting means from said electronic control circuit when said first converting means detects the partial load operation condition in the induction passage.
Claim 8
Dependent Claim
119 words
The system as set forth in claim 5, wherein said second converting means includes a bellows having a moving part operatively communicating with the ambient atmospheric pressure and a potentiometer operatively connected to said moving part and connected to a predetermined voltage such that when the ambient atmospheric pressure is low at a high altitude, said second output signal from said second converting means is higher than when said ambient atmospheric pressure is normal, said electronic control circuit includes a means for comparing said second output signal of said second converting means with a predetermined value and providing an output therefrom when said first converting means detects the idling and heavy load operation condition, respectively, in the induction passage.
Claim 9
Dependent Claim
97 words
The system as set forth in claim 1, wherein said second output signal is proportional to the atmospheric pressure and is higher with an increase in said altitude, said electronic control circuit includes means for providing a greater pulse duty ratio when said second output signal is higher than a lower value thereof when said second output signal is fed to said electronic control circuit as well as, respectively, when said output of said detecting means is higher than a lower value thereof when said electronic control circuit is responsive to said output of said detecting means.
Claim 10
Dependent Claim
87 words
The system as set forth in claim 1, 4 or 8 wherein said electronic control circuit includes an integration circuit operative when said electronic control circuit is responsive to said output of said detecting means, a third switch means for converting said integration circuit into a circuit having an output dependent on said second output signal when said first means renders said electronic control circuit non-responsive to the output of said detecting means and said second means feeds said second output signal to said electronic control circuit.
Claim 11
Dependent Claim
96 words
The system as set forth in claim 9, wherein said integration circuit includes an operational amplifier having a positive input connected to a voltage source, a capacitor connected across a negative input terminal of said operational amplifier and an output thereof and a resistor and said third switch means connected in series and together in parallel across said capacitor, said third switch means for being connected when said first converting means detects an idling and heavy load operation condition, respectively, in the induction passage and for being disconnected when said first converting means detects partial load.
Claim 12
Dependent Claim
54 words
The system as set forth in claim 4, further comprising a switch actuating circuit connected to said first converting means and having a first output controllably connected to said second switch means and a second output controllably connected to said first switch means, said second output and said first output have opposite voltage signals.
Claim 13
Dependent Claim
96 words
The system as set forth in claim 11, further comprising said electronic control circuit includes an integration circuit operative when said electronic control circuit is responsive to said output of said detecting means, a third switch means for converting said integration circuit into a circuit having an output dependent on said second output signal when said first means renders said electronic control circuit non-responsive to the output of said detecting means and said second means feeds said second output signal to said electronic control circuit, said first output is controllably connected to said third switch means.
Claim 14
Dependent Claim
79 words
The system as set forth in claim 11, wherein said switch actuating circuit includes a first transistor, said first converting means has an output connected to a base of said first transistor, said switch actuating circuit includes a second transistor and a base thereof connected to the collector of said first transistor, the latter constituting said first output of said switch actuating circuit, and a collector of said second transistor constitutes said second output of said switch actuating circuit.
Claim 15
Dependent Claim
73 words
The system as set forth in claim 13, wherein when said first converting means detects an idling and heavy load operation condition, respectively, in the induction passage, said first output has a high signal and said second output has a low signal, and when said first converting means detects a partial load operation condition, in the induction passage said first output has a low signal and said second output has a high signal.
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) | 1985-11-29 | 1986-05-31 | 1986-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-29 | 1990-05-31 | 1990-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-29 | 1994-05-31 | 1994-11-30 | $7700.00 | Window Closed / Lapsed |