Patent US5447137A successfully refreshed from Google Patents.
US5447137A
Expired / Lapsed
US
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Lean burn control method and device for internal combustion engine and fuel injection quantity control method and device including same
Assignee: Hitachi Ltd
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Filing: 1993-09-29
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Granted: 1995-09-05
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Expires: 2013-09-29
Abstract
Abstract A control device for an internal combustion engine capable of conducting lean burn control, such as exhaust gas emission control, always optimally regardless of a timewise change of the internal combustion engine, variations in engines, and an environmental change. The control device includes a detector for detecting a burn condition of the internal combustion engine, a lean limit air-fuel ratio factor map, a lean burn feedback logic, an oxygen concentration sensor, and a feedback control logic for controlling an air-fuel ratio to a theoretical air-fuel ratio, wherein lean burn is performed at the middle point between the lean limit air-fuel ratio and the theoretical air-fuel ratio.
Inventors
- 👤 Seiji Asano
- 👤 Takeshi Atago
- 👤 Nobuo Kurihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:20
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1497; F02D41/1498; F02D41/1438; F02D41/1473; F02D41/1475; F02D41/24; F02D41/2406; F02D41/2425; F02D41/2429; F02D41/2451; F02D41/2454; F02D2200/00; F02D2200/02; F02D2200/10; F02D2200/1015
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
211 words
A lean burn control device for an internal combustion engine, comprising: means for detecting a burn condition of said internal combustion engine; means for computing an internal condition variable representing a burn degree from an output from said means for detecting said burn condition; an oxygen concentration sensor provided in an exhaust pipe of said internal combustion engine for detecting an oxygen concentration in an exhaust gas; means for computing a first fuel quantity to be supplied to said internal combustion engine according to an output from said oxygen concentration sensor to control an air-fuel ratio to a theoretical air-fuel ratio; means for computing a second fuel quantity to be supplied to said internal combustion engine according to said internal condition variable representing said burn degree and an internal condition variable representing said theoretical air-fuel ratio; means for detecting one of a transition state and a steady state of said internal combustion engine; means for selecting one of said first fuel quantity and said second fuel quantity according to an output from said means for detecting one of said transition state and said steady state; means for detecting a rotational speed of said internal combustion engine; and means for detecting an air quantity to be sucked into said internal combustion engine.
Claim 2
Dependent Claim
211 words
A lean burn control device for an internal combustion engine, comprising: means for detecting a burn condition of said internal combustion engine; means for computing an internal condition variable representing a burn degree from an output from said means for detecting said burn condition; an oxygen concentration sensor provided in an exhaust pipe of said internal combustion engine for detecting an oxygen concentration in an exhaust gas; means for computing a first fuel quantity to be supplied to said internal combustion engine according to an output from said oxygen concentration sensor to control an air-fuel ratio to a theoretical air-fuel ratio; means for computing a second fuel quantity to be supplied to said internal combustion engine according to said internal condition variable representing said burn degree and an internal condition variable representing said theoretical air-fuel ratio; means for detecting one of a transition state and a steady state of said internal combustion engine; means for selecting one of said first fuel quantity and said second fuel quantity according to an output from said means for detecting one of said transition state and said steady state; means for detecting a rotational speed of said internal combustion engine; and means for detecting an air quantity to be sucked into said internal combustion engine.
Claim 3
Dependent Claim
42 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said means for detecting said burn condition of said internal combustion engine comprises a burning pressure sensor mounted in a combustion chamber of said internal combustion engine.
Claim 4
Dependent Claim
39 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said means for detecting said burn condition of said internal combustion engine comprises means for detecting a rotation fluctuation of said internal combustion engine.
Claim 5
Dependent Claim
41 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said means for detecting said burn condition of said internal combustion engine comprises means for detecting a natural frequency of combustion of said internal combustion engine.
Claim 6
Dependent Claim
43 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said means for detecting said burn condition of said internal combustion engine comprises means for detecting a frequency of light generated by combustion in said internal combustion engine.
Claim 7
Dependent Claim
46 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said oxygen concentration sensor for detecting said oxygen concentration in said exhaust gas comprises a sensor adapted to output a binary signal with respect to a threshold of said air-fuel ratio.
Claim 8
Dependent Claim
43 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said oxygen concentration sensor for detecting said oxygen concentration in said exhaust gas comprises a sensor adapted to output a linear signal with respect to said air-fuel ratio.
Claim 9
Dependent Claim
56 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said means for detecting one of said transition state and said steady state of said internal combustion engine comprises means for detecting a change in output from a throttle opening sensor provided in a suction pipe of said internal combustion engine.
Claim 10
Dependent Claim
48 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said means for detecting one of said transition state and said steady state of said internal combustion engine comprises means for detecting a change in said rotational speed of said internal combustion engine.
Claim 11
Dependent Claim
51 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said means for detecting one of said transition state and said steady state of said internal combustion engine comprises means for detecting a change in said air quantity to be sucked into said internal combustion engine.
Claim 12
Dependent Claim
36 words
A lean burn control device for an internal combustion engine according to claim 1, wherein said means for detecting said air quantity to be sucked into said internal combustion engine comprises a thermal air flow meter.
Claim 13
Dependent Claim
195 words
A lean burn control device for an internal combustion engine, comprising: a lean burn limit map preliminarily stored; an oxygen concentration sensor provided in an exhaust pipe of said internal combustion engine for detecting an oxygen concentration in an exhaust gas; means for computing a first fuel quantity to be supplied to said internal combustion engine according to an output from said oxygen concentration sensor to control an air-fuel ratio to a theoretical air-fuel ratio; means for computing a second fuel quantity to be supplied to said internal combustion engine according to a constant retrieved from said lean burn limit map according to a condition of said internal combustion engine and an internal condition variable representing said theoretical air-fuel ratio; means for detecting one of a transition state and a steady state of said internal combustion engine; means for selecting one of said first fuel quantity and said second fuel quantity according to an output from said means for detecting one of said transition state and said steady state; means for detecting a rotational speed of said internal combustion engine; and means for detecting an air quantity to be sucked into said internal combustion engine.
Claim 14
Dependent Claim
195 words
A lean burn control device for an internal combustion engine, comprising: a lean burn limit map preliminarily stored; an oxygen concentration sensor provided in an exhaust pipe of said internal combustion engine for detecting an oxygen concentration in an exhaust gas; means for computing a first fuel quantity to be supplied to said internal combustion engine according to an output from said oxygen concentration sensor to control an air-fuel ratio to a theoretical air-fuel ratio; means for computing a second fuel quantity to be supplied to said internal combustion engine according to a constant retrieved from said lean burn limit map according to a condition of said internal combustion engine and an internal condition variable representing said theoretical air-fuel ratio; means for detecting one of a transition state and a steady state of said internal combustion engine; means for selecting one of said first fuel quantity and said second fuel quantity according to an output from said means for detecting one of said transition state and said steady state; means for detecting a rotational speed of said internal combustion engine; and means for detecting an air quantity to be sucked into said internal combustion engine.
Claim 15
Dependent Claim
58 words
A lean burn control device for an internal combustion engine according to claim 12, wherein said lean burn limit map comprises a function of an output from said means for detecting said rotational speed of said internal combustion engine and an output from said means for detecting said air quantity to be sucked into said internal combustion engine.
Claim 16
Dependent Claim
270 words
A fuel injection quantity control device for an internal combustion engine, comprising: means for detecting a burn condition of said internal combustion engine; means for computing an internal condition variable representing a burn degree from an output from said means for detecting said burn condition; an oxygen concentration sensor provided in an exhaust pipe of said internal combustion engine for detecting an oxygen concentration in an exhaust gas; means for computing a first fuel quantity to be supplied to said internal combustion engine according to an output from said oxygen concentration sensor to control an air-fuel ratio to a theoretical air-fuel ratio; means for computing a second fuel quantity to be supplied to said internal combustion engine according to said internal condition variable representing said burn degree and an internal condition variable representing said theoretical air-fuel ratio; means for detecting one of a transition state and a steady state of said internal combustion engine; means for selecting one of said first fuel quantity and said second fuel quantity according to an output from said means for detecting one of said transition state and said steady state; means for detecting a rotational speed of said internal combustion engine; means for detecting an air quantity to be sucked into said internal combustion engine; a fuel injector; and means for computing a fuel injection quantity to be injected from said fuel injector into said internal combustion engine according to an output from said means for detecting said rotational speed of said internal combustion engine and an output from said means for detecting said air quantity to be sucked into said internal combustion engine.
Claim 17
Dependent Claim
270 words
A fuel injection quantity control device for an internal combustion engine, comprising: means for detecting a burn condition of said internal combustion engine; means for computing an internal condition variable representing a burn degree from an output from said means for detecting said burn condition; an oxygen concentration sensor provided in an exhaust pipe of said internal combustion engine for detecting an oxygen concentration in an exhaust gas; means for computing a first fuel quantity to be supplied to said internal combustion engine according to an output from said oxygen concentration sensor to control an air-fuel ratio to a theoretical air-fuel ratio; means for computing a second fuel quantity to be supplied to said internal combustion engine according to said internal condition variable representing said burn degree and an internal condition variable representing said theoretical air-fuel ratio; means for detecting one of a transition state and a steady state of said internal combustion engine; means for selecting one of said first fuel quantity and said second fuel quantity according to an output from said means for detecting one of said transition state and said steady state; means for detecting a rotational speed of said internal combustion engine; means for detecting an air quantity to be sucked into said internal combustion engine; a fuel injector; and means for computing a fuel injection quantity to be injected from said fuel injector into said internal combustion engine according to an output from said means for detecting said rotational speed of said internal combustion engine and an output from said means for detecting said air quantity to be sucked into said internal combustion engine.
Claim 18
Dependent Claim
254 words
A fuel injection quantity control device for an internal combustion engine, comprising: a lean burn limit map preliminarily stored; an oxygen concentration sensor provided in an exhaust pipe of said internal combustion engine for detecting an oxygen concentration in an exhaust gas; means for computing a first fuel quantity to be supplied to said internal combustion engine according to an output from said oxygen concentration sensor to control an air-fuel ratio to a theoretical air-fuel ratio; means for computing a second fuel quantity to be supplied to said internal combustion engine according to a constant retrieved from said lean burn limit map according to a condition of said internal combustion engine and an internal condition variable representing said theoretical air-fuel ratio; means for detecting one of a transition state and a steady state of said internal combustion engine; means for selecting one of said first fuel quantity and said second fuel quantity according to an output from said means for detecting one of said transition state and said steady state; means for detecting a rotational speed of said internal combustion engine; means for detecting an air quantity to be sucked into said internal combustion engine; a fuel injector; and means for computing a fuel injection quantity to be injected from said fuel injector into said internal combustion engine according to an output from said means for detecting said rotational speed of said internal combustion engine and an output from said means for detecting said air quantity to be sucked into said internal combustion engine.
Claim 19
Dependent Claim
254 words
A fuel injection quantity control device for an internal combustion engine, comprising: a lean burn limit map preliminarily stored; an oxygen concentration sensor provided in an exhaust pipe of said internal combustion engine for detecting an oxygen concentration in an exhaust gas; means for computing a first fuel quantity to be supplied to said internal combustion engine according to an output from said oxygen concentration sensor to control an air-fuel ratio to a theoretical air-fuel ratio; means for computing a second fuel quantity to be supplied to said internal combustion engine according to a constant retrieved from said lean burn limit map according to a condition of said internal combustion engine and an internal condition variable representing said theoretical air-fuel ratio; means for detecting one of a transition state and a steady state of said internal combustion engine; means for selecting one of said first fuel quantity and said second fuel quantity according to an output from said means for detecting one of said transition state and said steady state; means for detecting a rotational speed of said internal combustion engine; means for detecting an air quantity to be sucked into said internal combustion engine; a fuel injector; and means for computing a fuel injection quantity to be injected from said fuel injector into said internal combustion engine according to an output from said means for detecting said rotational speed of said internal combustion engine and an output from said means for detecting said air quantity to be sucked into said internal combustion engine.
Claim 20
Dependent Claim
192 words
A lean burn control method for an internal combustion engine, comprising the steps of: detecting a burn condition of said internal combustion engine; computing an internal condition variable representing a burn degree from a result of detection in said step of detecting said burn condition; detecting an oxygen concentration in an exhaust gas; computing a first fuel quantity to be supplied to said internal combustion engine according to a result of detection in said step of detecting said oxygen concentration to control an air-fuel ratio to a theoretical air-fuel ratio; computing a second fuel quantity to be supplied to said internal combustion engine according to said internal condition variable representing said burn degree and an internal condition variable representing said theoretical air-fuel ratio; detecting one of a transition state and a steady state of said internal combustion engine; selecting one of said first fuel quantity and said second fuel quantity according to a result of detection in said step of detecting one of said transition state and said steady state; detecting a rotational speed of said internal combustion engine; and detecting an air quantity to be sucked into said internal combustion engine.
Claim 21
Dependent Claim
192 words
A lean burn control method for an internal combustion engine, comprising the steps of: detecting a burn condition of said internal combustion engine; computing an internal condition variable representing a burn degree from a result of detection in said step of detecting said burn condition; detecting an oxygen concentration in an exhaust gas; computing a first fuel quantity to be supplied to said internal combustion engine according to a result of detection in said step of detecting said oxygen concentration to control an air-fuel ratio to a theoretical air-fuel ratio; computing a second fuel quantity to be supplied to said internal combustion engine according to said internal condition variable representing said burn degree and an internal condition variable representing said theoretical air-fuel ratio; detecting one of a transition state and a steady state of said internal combustion engine; selecting one of said first fuel quantity and said second fuel quantity according to a result of detection in said step of detecting one of said transition state and said steady state; detecting a rotational speed of said internal combustion engine; and detecting an air quantity to be sucked into said internal combustion engine.
Claim 22
Dependent Claim
40 words
A lean burn control method for an internal combustion engine according to claim 16, wherein said step of detecting said burn condition of said internal combustion engine comprises a step of detecting a rotation fluctuation of said internal combustion engine.
Claim 23
Dependent Claim
42 words
A lean burn control method for an internal combustion engine according to claim 16, wherein said step of detecting said burn condition of said internal combustion engine comprises a step of detecting a natural frequency of combustion of said internal combustion engine.
Claim 24
Dependent Claim
44 words
A lean burn control method for an internal combustion engine according to claim 16, wherein said step of detecting said burn condition of said internal combustion engine comprises a step of detecting a frequency of light generated by combustion in said internal combustion engine.
Claim 25
Dependent Claim
43 words
A lean burn control method for an internal combustion engine according to claim 16, wherein said step of detecting said oxygen concentration in said exhaust gas comprises a step of outputting a binary signal with respect to a threshold of said air-fuel ratio.
Claim 26
Dependent Claim
40 words
A lean burn control method for an internal combustion engine according to claim 16, wherein said step of detecting said oxygen concentration in said exhaust gas comprises a step of outputting a linear signal with respect to said air-fuel ratio.
Claim 27
Dependent Claim
49 words
A lean burn control method for an internal combustion engine according to claim 16, wherein said step of detecting one of said transition state and said steady state of said internal combustion engine comprises a step of detecting a change in said rotational speed of said internal combustion engine.
Claim 28
Dependent Claim
52 words
A lean burn control method for an internal combustion engine according to claim 16, wherein said step of detecting one of said transition state and said steady state of said internal combustion engine comprises a step of detecting a change in said air quantity to be sucked into said internal combustion engine.
Claim 29
Dependent Claim
173 words
A lean burn control method for an internal combustion engine, comprising the steps of: detecting an oxygen concentration in an exhaust gas; computing a first fuel quantity to be supplied to said internal combustion engine according to a result of detection in said step of detecting said oxygen concentration to control an air-fuel ratio to a theoretical air-fuel ratio; computing a second fuel quantity to be supplied to said internal combustion engine according to a constant retrieved from a lean burn limit map preliminarily stored according to a condition of said internal combustion engine and an internal condition variable representing said theoretical air-fuel ratio; detecting one of a transition state and a steady state of said internal combustion engine; selecting one of said first fuel quantity and said second fuel quantity according to a result of detection in said step of detecting one of said transition state and said steady state; detecting a rotational speed of said internal combustion engine; and detecting an air quantity to be sucked into said internal combustion engine.
Claim 30
Dependent Claim
173 words
A lean burn control method for an internal combustion engine, comprising the steps of: detecting an oxygen concentration in an exhaust gas; computing a first fuel quantity to be supplied to said internal combustion engine according to a result of detection in said step of detecting said oxygen concentration to control an air-fuel ratio to a theoretical air-fuel ratio; computing a second fuel quantity to be supplied to said internal combustion engine according to a constant retrieved from a lean burn limit map preliminarily stored according to a condition of said internal combustion engine and an internal condition variable representing said theoretical air-fuel ratio; detecting one of a transition state and a steady state of said internal combustion engine; selecting one of said first fuel quantity and said second fuel quantity according to a result of detection in said step of detecting one of said transition state and said steady state; detecting a rotational speed of said internal combustion engine; and detecting an air quantity to be sucked into said internal combustion engine.
Claim 31
Dependent Claim
250 words
A fuel injection quantity control method for an internal combustion engine, comprising the steps of: detecting a burn condition of said internal combustion engine; computing an internal condition variable representing a burn degree from a result of detection in said step of detecting said burn condition; detecting an oxygen concentration in an exhaust gas; computing a first fuel quantity to be supplied to said internal combustion engine according to a result of detection in said step of detecting said oxygen concentration to control an air-fuel ratio to a theoretical air-fuel ratio; computing a second fuel quantity to be supplied to said internal combustion engine according to said internal condition variable representing said burn degree and an internal condition variable representing said theoretical air-fuel ratio; detecting one of a transition state and a steady state of said internal combustion engine; selecting one of said first fuel quantity and said second fuel quantity according to a result of detection in said step of detecting one of said transition state and said steady state; detecting a rotational speed of said internal combustion engine; detecting an air quantity to be sucked into said internal combustion engine; and computing a fuel injection quantity to be injected from a fuel injector into said internal combustion engine according to a result of detection in said step of detecting said rotational speed of said internal combustion engine and a result of detection in said step of detecting said air quantity to be sucked into said internal combustion engine.
Claim 32
Dependent Claim
250 words
A fuel injection quantity control method for an internal combustion engine, comprising the steps of: detecting a burn condition of said internal combustion engine; computing an internal condition variable representing a burn degree from a result of detection in said step of detecting said burn condition; detecting an oxygen concentration in an exhaust gas; computing a first fuel quantity to be supplied to said internal combustion engine according to a result of detection in said step of detecting said oxygen concentration to control an air-fuel ratio to a theoretical air-fuel ratio; computing a second fuel quantity to be supplied to said internal combustion engine according to said internal condition variable representing said burn degree and an internal condition variable representing said theoretical air-fuel ratio; detecting one of a transition state and a steady state of said internal combustion engine; selecting one of said first fuel quantity and said second fuel quantity according to a result of detection in said step of detecting one of said transition state and said steady state; detecting a rotational speed of said internal combustion engine; detecting an air quantity to be sucked into said internal combustion engine; and computing a fuel injection quantity to be injected from a fuel injector into said internal combustion engine according to a result of detection in said step of detecting said rotational speed of said internal combustion engine and a result of detection in said step of detecting said air quantity to be sucked into said internal combustion engine.
Claim 33
Dependent Claim
230 words
A lean burn control method for an internal combustion engine, comprising the steps of: detecting an oxygen concentration in an exhaust gas; computing a first fuel quantity to be supplied to said internal combustion engine according to a result of detection in said step of detecting said oxygen concentration to control an air-fuel ratio to a theoretical air-fuel ratio; computing a second fuel quantity to be supplied to said internal combustion engine according to a constant retrieved from a lean burn limit map preliminarily stored according to a condition of said internal combustion engine and an internal condition variable representing said theoretical air-fuel ratio; detecting one of a transition state and a steady state of said internal combustion engine; selecting one of said first fuel quantity and said second fuel quantity according to a result of detection in said step of detecting one of said transition state and said steady state; detecting a rotational speed of said internal combustion engine; detecting an air quantity to be sucked into said internal combustion engine; and computing a fuel injection quantity to be injected from a fuel injector into said internal combustion engine according to a result of detection in said step of detecting said rotational speed of said internal combustion engine and a result of detection in said step of detecting said air quantity to be sucked into said internal combustion engine.
Claim 34
Dependent Claim
230 words
A lean burn control method for an internal combustion engine, comprising the steps of: detecting an oxygen concentration in an exhaust gas; computing a first fuel quantity to be supplied to said internal combustion engine according to a result of detection in said step of detecting said oxygen concentration to control an air-fuel ratio to a theoretical air-fuel ratio; computing a second fuel quantity to be supplied to said internal combustion engine according to a constant retrieved from a lean burn limit map preliminarily stored according to a condition of said internal combustion engine and an internal condition variable representing said theoretical air-fuel ratio; detecting one of a transition state and a steady state of said internal combustion engine; selecting one of said first fuel quantity and said second fuel quantity according to a result of detection in said step of detecting one of said transition state and said steady state; detecting a rotational speed of said internal combustion engine; detecting an air quantity to be sucked into said internal combustion engine; and computing a fuel injection quantity to be injected from a fuel injector into said internal combustion engine according to a result of detection in said step of detecting said rotational speed of said internal combustion engine and a result of detection in said step of detecting said air quantity to be sucked into said internal combustion engine.
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