EP0170428A2
Expired / Lapsed
EP
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Air-fuel ratio detecting device
Assignee: Niterra Co Ltd
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Filing: 1985-07-03
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Granted: —
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Expires: 2005-07-03
Abstract
Abstract In an air-fuel ratio detecting device with which the air-fuel ratio can be accurately detected over the entire range of ratios, both for the lean range and for the rich range, an oxygen pumping element (36) and an oxygen sensing element (32) are arranged opposite one another with a gap therebetween and are disposed in a chamber in which exhaust gas flows. A signal which is symmetric in lean and rich regions can thereby be obtained, and this signal is divided into separate portions in the two regions, which are then composed with a signal from a theoretical air-fuel ratio detecting means (40) to obtain a single-valued signal accurately representing the air-fuel ratio over the entire operating range.
Inventors
- 👤 Toshiyuki Ngk Spark Plug Co. Ltd. Ishihara
- 👤 Takeshi Ngk Spark Plug Co. Ltd. Kamiya
- 👤 Yutaka Ngk Spark Plug Co. Ltd. Nakayama
- 👤 Tetsusyo Ngk Spark Plug Co. Ltd. Yamada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 02:08
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/417; G01N27/403; G01N27/406; G01N27/4065
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
241 words
An air-fuel ratio detecting device comprising; a detecting element section (I)(32,36) having two elements arranged in opposition to one another and disposed in a chamber in which an exhaust gas flows, each of said elements (32,36) being made of an oxygen-ion-conductive solid electrolyte (33,37) provided with porous electrodes (34a,34b,35a,35b,38c, 38d,39c,39d) on its opposite surfaces; theoretical air-fuel ratio detecting means (40) for detecting a theoretical air-fuel ratio to produce a theoretical air-fuel ratio signal for determining whether an air-fuel ratio is in a lean region or in a rich region; air-fuel ratio signal detecting means (v), employing one of said two elements (32,36) in said detecting element section as an oxygen sensing element (III)(32) and the other as an oxygen pumping element (IV)(36), for controlling one of an electromotive force of said oxygen sensing element (III)(32) and a pumping current flowing in said oxygen pumping element (IV)(36), thereby producing an air-fuel ratio signal corresponding to the air-fuel ratio in each of lean and rich regions of said air-fuel ratio; and actual air-fuel ratio signal detecting means (VI) receiving said theoretical air-fuel ratio signal produced by said theoretical air-fuel ratio detecting means (II)(40) for detecting an actual air-fuel ratio signal corresponding to an actual air-fuel ratio over an entire range of air-fuel ratios, wherein said air-fuel ratio signal produced by said air-fuel ratio signal detecting means is inverted when said air-fuel ratio is in a predetermined one of said lean and rich regions.
Claim 2
Dependent Claim
241 words
An air-fuel ratio detecting device comprising; a detecting element section (I)(32,36) having two elements arranged in opposition to one another and disposed in a chamber in which an exhaust gas flows, each of said elements (32,36) being made of an oxygen-ion-conductive solid electrolyte (33,37) provided with porous electrodes (34a,34b,35a,35b,38c, 38d,39c,39d) on its opposite surfaces; theoretical air-fuel ratio detecting means (40) for detecting a theoretical air-fuel ratio to produce a theoretical air-fuel ratio signal for determining whether an air-fuel ratio is in a lean region or in a rich region; air-fuel ratio signal detecting means (v), employing one of said two elements (32,36) in said detecting element section as an oxygen sensing element (III)(32) and the other as an oxygen pumping element (IV)(36), for controlling one of an electromotive force of said oxygen sensing element (III)(32) and a pumping current flowing in said oxygen pumping element (IV)(36), thereby producing an air-fuel ratio signal corresponding to the air-fuel ratio in each of lean and rich regions of said air-fuel ratio; and actual air-fuel ratio signal detecting means (VI) receiving said theoretical air-fuel ratio signal produced by said theoretical air-fuel ratio detecting means (II)(40) for detecting an actual air-fuel ratio signal corresponding to an actual air-fuel ratio over an entire range of air-fuel ratios, wherein said air-fuel ratio signal produced by said air-fuel ratio signal detecting means is inverted when said air-fuel ratio is in a predetermined one of said lean and rich regions.
Claim 3
Dependent Claim
34 words
The air-fuel ratio detecting device according to claim l, wherein said actual air-fuel ratio signal detecting means comprises means for producing an actual air-fuel ratio signal which changes stepwise at a theoretical air-fuel ratio.
Claim 4
Dependent Claim
43 words
The air-fuel ratio detecting device according to claim 1, wherein said theoretical air-fuel ratio detecting means (40) comprises a theoretical air-fuel ratio detecting element made of an electrically insulating member (41) provided with a metal oxide semiconductor segment (45) on a surface thereof.
Claim 5
Dependent Claim
56 words
The air-fuel ratio detecting device according to any one of claims 1 to 3, wherein said air-fuel ratio signal detecting means comprises means for controlling said pumping current of said oxygen pumping element (36) so as to make an electromotive force of said oxygen sensing element (32) constant, said pumping current forming said air-fuel ratio signal.
Claim 6
Dependent Claim
34 words
The air-fuel ratio detecting device according to any one of claims 1 to 3, wherein said chamber is a gap formed between said two elements, said gap being opened at an edge portion thereof.
References Cited (Backward Citations)
No citation records indexed.
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