EP0272814A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Air/fuel ratio controller for engine
Assignee: Mitsubishi Motors Corp
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Filing: 1987-11-27
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Granted: —
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Expires: 2007-11-27
Abstract
Abstract To make the air/fuel ratio leaner in a light-load operation zone or the like of a lean burn engine (14), and to improve the starting performance and acceleration feeling of the engine significantly, upon generation of an acceleration command by a driver by idle switch (10) during lean burn of the engine at a lean air/fuel ratio, an air/fuel ratio enriching device (1, 2) is operated to set the air/fuel ratio of an air-fuel mixture, which is to be fed to the engine (14), at a level richer than the lean air/fuel ratio while an actually accelerated state continues in the engine (14) from the time point of generation of the acceleration command.
Inventors
- 👤 Nobuaki Murakami
- 👤 Osamu Hirako
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 23:12
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/04; F02D41/10; F02D41/14; F02D41/1438; F02D41/1486; F02D41/1473; F02D41/1475; F02D41/1444; F02D41/1454; F02D41/1456
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
268 words
An airfuel ratio controller for an engine (14), said controller being equipped with an engine operation zone discriminating means (8,3) for discriminating a specific operation zone of the engine and a lean air/fuel ratio setting means for setting the air/fuel ratio of an air-fuel mixture, which is to be fed to the engine (14), at a level leaner than a stoichiometric airifuel ratio upon receipt of an engine operation zone discriminating signal from said engine operation zone discriminating means, which comprises: a means for detecting an acceleration command to the engine; a means for detecting an actually accelerated state of the engine established responsive to the acceleration command; an air / fuel ratio enriching means operable preferentially to said lean air/fuel ratio setting means so as to set the air/fuel ratio of the air-fuel mixture, which is to be fed to the engine, at a level richer than the air/fuel ratio leaner than the stoichiometric air;fuel ratio; and an air/fuel ratio enrichment control means for setting both starting time and ending time of an operation of said air / fuel ratio enriching means upon receipt of a signal from said acceleration command detecting means and another signal from said accelerated state detecting means, whereby the air/fuel ratio of the air-fuel mixture to be fed to the engine is set at a level richer than the air / fuel ratio leaner than the stoichiometric air / fuel ratio owing to an operation of said air / fuel ratio enriching means while the actually accelerated state continues in the engine from the time point of generation of the acceleration command.
Claim 2
Dependent Claim
268 words
An airfuel ratio controller for an engine (14), said controller being equipped with an engine operation zone discriminating means (8,3) for discriminating a specific operation zone of the engine and a lean air/fuel ratio setting means for setting the air/fuel ratio of an air-fuel mixture, which is to be fed to the engine (14), at a level leaner than a stoichiometric airifuel ratio upon receipt of an engine operation zone discriminating signal from said engine operation zone discriminating means, which comprises: a means for detecting an acceleration command to the engine; a means for detecting an actually accelerated state of the engine established responsive to the acceleration command; an air / fuel ratio enriching means operable preferentially to said lean air/fuel ratio setting means so as to set the air/fuel ratio of the air-fuel mixture, which is to be fed to the engine, at a level richer than the air/fuel ratio leaner than the stoichiometric air;fuel ratio; and an air/fuel ratio enrichment control means for setting both starting time and ending time of an operation of said air / fuel ratio enriching means upon receipt of a signal from said acceleration command detecting means and another signal from said accelerated state detecting means, whereby the air/fuel ratio of the air-fuel mixture to be fed to the engine is set at a level richer than the air / fuel ratio leaner than the stoichiometric air / fuel ratio owing to an operation of said air / fuel ratio enriching means while the actually accelerated state continues in the engine from the time point of generation of the acceleration command.
Claim 3
Dependent Claim
59 words
The air/fuel ratio controller as claimed in Claim 1, wherein said air/fuel ratio enrichment control means causes said air/fuel ratio enriching means to start operating upon receipt of the signal from said acceleration command detecting means and causes said air fuel ratio enriching means to cease operating upon receipt of said another signal from said accelerated state detecting means.
Claim 4
Dependent Claim
36 words
The air fuel ratio controller as claimed in Claim 1, wherein said accelerated state detecting means detects the actually accelerated state of the engine on the basis of a change in revolution number of the engine.
Claim 5
Dependent Claim
202 words
The air/fuel ratio controller as claimed in Claim 1, wherein a timer means for generating a signal, which lasts from the starting time point of the acceleration command until the lapse of a predetermined period of time, based on detection results by said acceleration command detecting means is connected functionally to said acceleration command detecting means, said accelerated state detecting means continues to generate a signal from the time point of detection of initiation of the actually accelerated state of the engine or an accelerated state right after the initiation of the actually accelerated state until the detection of the termination of the actually accelerated state of the engine or an accelerated state right before the termination of the actually accelerated state when the initiation of the actually accelerated state of the engine or the accelerated state right after the initiation of the actually accelerated state is detected during the generation of the signal from said timer means, and said air/fuel ratio enrichment control means causes said air/fuel ratio enriching means to operate continuously during a period in which a logical sum is established between the signal from said acceleration command detecting means and the signal from said accelerated state detecting means.
Claim 6
Dependent Claim
66 words
The air/fuel ratio controller as claimed in Claim 4, wherein said accelerated state detecting means generates the signal from a time point that the revolution number increment of the engine has exceeded a predetermined positive value until another time point that the revolution number increment has become smaller than the predetermined positive value or another predetermined positive value smaller than the first-mentioned predetermined positive value .
Claim 7
Dependent Claim
86 words
The air/fuel ratio controller as claimed in Claim 4, wherein the engine is adapted to be mounted on a vehicle, said acceleration command detecting means comprises a start-up acceleration command detecting means for detecting an acceleration command at the time of starting of the vehicle and an ordinary-time acceleration command detecting means for detecting an acceleration command during ordinary running of the vehicle, and the predetermined period of time is set longer for said start-up acceleration command detecting means than for ordinary-time acceleration command detecting means.
Claim 8
Dependent Claim
100 words
The air / fuel ratio controller as claimed in Claim 4, wherein the engine is adapted to be mounted on a vehicle, said acceleration command detecting means comprises a start-up acceleration command detecting means for detecting an acceleration command at the time of starting of the vehicle, and said start-up acceleration command detecting means detects the acceleration command on the basis of a displacement of an artificial acceleration control member or an engine power control element (12), which is actuated responsive to the member, from an idling position during an idling operation at the time of standing of the vehicle.
Claim 9
Dependent Claim
82 words
The air/fuel ratio controller as claimed in Claim 7, further comprising an air/fuel ratio enrichment terminating means for terminating the operation of said air/fuel ratio enriching means preferentially to said air/fuel ratio enrichment control means when a displacement of the artificial acceleration control member or engine power control element in an engine power reducing direction is detected after the signal from said start-up acceleration command detecting means has been generated but before the signal from said accelerated state detecting means is generated.
Claim 10
Dependent Claim
40 words
The air/fuel ratio controller as claimed in Claim 1, wherein said air / fuel ratio enriching means sets, at the stoichiometric air / fuel ratio, the air / fuel ratio of the air-fuel mixture to be fed to the engine.
Claim 11
Dependent Claim
9 words
An air / fuel ratio controller for an engine
Claim 12
Dependent Claim
9 words
An air / fuel ratio controller for an engine
Claim 13
Dependent Claim
215 words
(14), said controller being equipped with a means (8,3) for detecting the state of load of the engine and a lean air/fuel ratio setting means for setting the air/fuel ratio of an air-fuel mixture, which is to be fed to the engine (14), at a level leaner than a stoichiometric airifuel ratio upon receipt of a signal from said engine load state detecting means in an operation state of a load level not higher than a predetermined load level, which comprises: a means for detecting an acceleration command to the engine; a means for detecting an actually accelerated state of the engine established responsive to the acceleration command; and a load level changing means for changing an upper limit of operable load levels for said lean air / fuel ratio setting means to a second load level (L3) lower than the predetermined load level upon receipt of a signal from said acceleration command detecting means and another signal from said accelerated state detecting means, whereby the upper limit of operable load levels of said lean air/fuel ratio setting means is maintained at the second load level (L3) by an actuation of said load level changing means while an actually accelerated state continues in the engine from the time point of generation of the acceleration command.
Claim 14
Dependent Claim
215 words
(14), said controller being equipped with a means (8,3) for detecting the state of load of the engine and a lean air/fuel ratio setting means for setting the air/fuel ratio of an air-fuel mixture, which is to be fed to the engine (14), at a level leaner than a stoichiometric airifuel ratio upon receipt of a signal from said engine load state detecting means in an operation state of a load level not higher than a predetermined load level, which comprises: a means for detecting an acceleration command to the engine; a means for detecting an actually accelerated state of the engine established responsive to the acceleration command; and a load level changing means for changing an upper limit of operable load levels for said lean air / fuel ratio setting means to a second load level (L3) lower than the predetermined load level upon receipt of a signal from said acceleration command detecting means and another signal from said accelerated state detecting means, whereby the upper limit of operable load levels of said lean air/fuel ratio setting means is maintained at the second load level (L3) by an actuation of said load level changing means while an actually accelerated state continues in the engine from the time point of generation of the acceleration command.
References Cited (Backward Citations)
No citation records indexed.
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