EP0814248A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of controlling an engine exhaust gas system and method of detecting deterioration of catalyst/adsorbing means
Assignee: NGK Insulators Ltd
•
Filing: 1997-06-20
•
Granted: —
•
Expires: 2017-06-20
Abstract
Abstract In a method of controlling an exhaust gas system of an internal combustion engine including a nitrogen oxide reducing catalyst capable of adsorbing nitrogen oxide under a lean atmosphere and a nitrogen oxide sensor disposed downstream of the nitrogen oxide reducing catalyst, the nitrogen oxide reducing catalyst and the nitrogen oxide sensor are disposed in the exhaust gas system operated mainly under a lean condition, respectively. An output value of the nitrogen oxide sensor is compared with a predetermined value, and an operation condition of the internal combustion engine is temporarily changed into a stoichiometric condition or a rich condition, or a fuel is injected upstream of the nitrogen oxide reducing catalyst, so that the nitrogen oxide adsorbed to the nitrogen oxide reducing catalyst is detached or decomposed, and again the internal combustion engine is operated under the lean condition. <IMAGE>
Inventors
- 👤 Nobuhide Kato
- 👤 Hiroshi B-101 NGK Horagai-shataku Kurachi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 11:05
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1444; F02D41/146; B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9404; B01D53/9409; B01D53/9431; B01D53/9495; F01; F01N; F01N11/00; F01N3/00; F01N3/08; F01N3/0807; F01N3/0814; F01N3/0828; F01N3/0842; F01N3/0871; F02D41/021; F02D41/0235; F02D41/027; F02D41/0275; F02D41/1439; F02D41/1441; F02D41/1463; F01N2250/00; F01N2250/12; F01N2430/00; F01N2430/06; F01N2550/00; F01N2550/02; F01N2550/03; F01N2610/00; F01N2610/03; F02B; F02B1/00; F02B1/02; F02B1/04; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
128 words
A method of controlling an exhaust gas system of an internal combustion engine including a nitrogen oxide reducing catalyst capable of adsorbing nitrogen oxide under a lean atmosphere and a nitrogen oxide sensor disposed downstream of the nitrogen oxide reducing catalyst, the nitrogen oxide reducing catalyst and the nitrogen oxide sensor being disposed in the exhaust gas system operated mainly under a lean condition, respectively, wherein an output value of said nitrogen oxide sensor is compared with a predetermined value, and an operation condition of said internal combustion engine is temporarily changed into a stoichiometric condition or a rich condition so that the nitrogen oxide adsorbed to said nitrogen oxide reducing catalyst is detached or decomposed and again said internal combustion engine is operated under the lean condition.
Claim 2
Independent Claim
120 words
A method of controlling an exhaust gas system of an internal combustion engine including a nitrogen oxide reducing catalyst capable of adsorbing nitrogen oxide under a lean atmosphere and a nitrogen oxide sensor disposed downstream of the nitrogen oxide reducing catalyst, the nitrogen oxide reducidng catalyst and the nitrogen oxide sensor being disposed in the exhaust gas system operated mainly under a lean condition, respectively, wherein an output value of said nitrogen oxide sensor is compared with a predetermined value, and a fuel is injected upstream of said nitrogen oxide reducing catalyst so that the nitrogen oxide adsorbed to said nitrogen oxide reducing catalyst is detached or decomposed, and again said internal combustion engine is operated under the lean condition.
Claim 3
Dependent Claim
49 words
A method of controlling an exhaust gas system of an internal combustion engine as claimed in claim 1 or 2, wherein a nitrogen oxide sensor is disposed upstream of said nitrogen oxide reducing catalyst in addition to said nitrogen oxide sensor disposed downstream of said nitrogen oxide reducing catalyst.
Claim 4
Independent Claim
137 words
A method of controlling an exhaust gas system of an internal combustion engine including an adsorbing means capable of adsorbing nitrogen oxide under a lean atmosphere, a nitrogen oxide reducing catalyst disposed downstream of the adsorbing means or integrally with the adsorbing means, and a nitrogen oxide sensor disposed downstream of the adsorbing means, the adsorbing means, the nitrogen oxide reducing catalyst and the nitrogen oxide sensor being disposed in the exhaust gas system operated mainly under a lean condition, respectively, wherein an output value of said nitrogen oxide sensor is compared with a predetermined value, and the operation condition of said internal combustion engine is temporarily made stoichiometric or rich so that the nitrogen oxide adsorbed to said adsorbing means is detached or decomposed, and again said internal combustion engine is operated under the lean condition.
Claim 5
Independent Claim
132 words
A method of controlling an exhaust gas system of an internal combustion engine including an adsorbing means capable of adsorbing nitrogen oxide under a lean atmosphere, a nitrogen oxide reducing catalyst disposed downstream of the adsorbing means or integrally with the adsorbing means, and a nitrogen oxide sensor disposed downstream of the adsorbing means, the adsorbing means, the nitrogen oxide reducing catalyst and the nitrogen oxide sensor being disposed in the exhaust gas system operated mainly under a lean condition, respectively, wherein an output value of said nitrogen oxide sensor is compared with a predetermined value, and a fuel is injected upstream of said adsorbing means so that the nitrogen oxide adsorbed to said adsorbing means is detached or decomposed, and again said internal combustion engine is operated under the lean condition.
Claim 6
Dependent Claim
45 words
A method of controlling an exhaust gas system of an internal combustion engine as claimed in claim 4 or 5, wherein a nitrogen oxide sensor is disposed upstream of said adsorbing means in addition to said nitrogen oxide sensor disposed downstream of said adsorbing means.
Claim 7
Independent Claim
43 words
A method of controlling an exhaust gas system of an internal combustion engine as claimed in any one of claims 1 to 6, wherein start of operation under the lean condition is executed based on the output value of said nitrogen oxide sensor.
Claim 8
Independent Claim
50 words
A method of controlling an exhaust gas system of an internal combustion engine as claimed in any one of claims 1 to 6, wherein start of operation under the lean condition is executed based on a time programmed in advance based on an operation condition of said internal combustion engine.
Claim 9
Independent Claim
156 words
A method of controlling an exhaust gas system of an internal combustion engine as claimed in any one of claims 1 to 8, wherein said nitrogen oxide sensor comprises a base made of an oxygen ion conductive solid electrolyte; an electrochemical pump cell formed of an inner pump electrode and an outer pump electrode disposed inside and outside of said base; a main pump means for pumping oxygen contained in measured gas introduced from an outside space based on a control voltage applied between said inner pump electrode and said outer pump electrode; a pair of detection electrodes, one of which is disposed at a side where the measured gas pumped by said main pump means is introduced; and an electric signal conversion means for generating an electric signal in accordance with an amount of oxygen generated by decomposition or reduction of NOx contained in the measured gas after being pumped by said main pump means.
Claim 10
Independent Claim
76 words
A method of detecting deterioration of a catalyst, characterized in that in the method of controlling an exhaust gas system of an internal combustion engine as claimed in any one of claims 1 to 3, deterioration of said nitrogen oxide reducing catalyst is detected based on the output value of said nitrogen oxide sensor, a period of time of continuation of a lean condition, or a repetition period of the lean condition and a rich condition.
Claim 11
Independent Claim
81 words
A method of detecting deterioration of a catalyst/adsorbing means, characterized in that in the method of controlling an exhaust gas system of an internal combustion engine as claimed in any one of claims 4 to 9, deterioration of said nitrogen oxide reducing catalyst or said adsorbing means is detected based on the output value of said nitrogen oxide sensor, a period of time of continuation of a lean condition, or a repetition period of the lean condition and a rich condition.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.