US5339628A
Expired / Lapsed
US
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Method for monitoring the catalytic activity of a catalytic converter in the exhaust gas system of an internal combustion engine
Assignee: Vitesco Technologies Lohmar Verwaltungs GmbH
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Filing: 1993-03-01
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Granted: 1994-08-23
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Expires: 2013-03-01
Abstract
Abstract A method for monitoring catalytic activity of a catalytic converter through which exhaust gas can flow in an exhaust system of an internal combustion engine includes measuring a temperature at least at two temperature measuring sensors and periodically repeatedly determining a temperature measuring variable from signals issued by the sensors during operation of the engine with an engine monitoring system. According to one method, the sensors are spaced apart in flow direction in or near the catalytic converter, the temperature measuring variable is averaged over a sufficiently long period of engine operation to average out special strains and form a mean temperature value, catalytic activity is ascertained by comparing the mean temperature value with a predetermined limit value, and a report is issued if the mean temperature value does not correspond to the limit value. According to another method, the sensors are associated with the catalytic converter, further measuring variables characterizing an applicable operating state of the engine are determined, a temperature limit value is determined from the further measuring variables, catalytic activity is determined by comparing the temperature measuring variable with the temperature limit value, and a report is issued if the temperature measuring variable is lower than the temperature limit value.
Inventors
- 👤 Wolfgang Maus
- 👤 Helmut Swars
- 👤 Rolf Bruck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:24
CPC Classifications
F; F01; F01N; F01N11/00; F01N11/002; F02; F02B; F02B77/00; F02B77/08; F01N13/00; F01N13/008; F01N9/00; F02B77/085; F02B77/086; G; G01; G01K; G01K7/00; G01K7/16; G01K7/18; G01M; G01M13/00; F01N2550/00; F01N2550/02; F02B1/00; F02B1/02; F02B1/04; F02B3/00; F02B3/06; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
140 words
A method for monitoring catalytic activity of a catalytic converter through which exhaust gas can flow in an exhaust system of an internal combustion engine, which comprises: measuring a temperature at least at two temperature measuring sensors of which at least one is disposed in the catalytic converter and which sensors are spaced apart in flow direction; periodically repeatedly determining a temperature measuring variable from signals issued by the sensors during operation of the engine with an engine monitoring system; averaging the temperature measuring variable over a sufficiently long period of engine operation to form a mean temperature value which is substantially unaffected by short-term load conditions; comparing the mean temperature value with a predetermined limit value; and indicating if a mean temperature value does not correspond to the limit value and ascertaining a catalytic activity of the catalytic converter.
Claim 2
Independent Claim
140 words
A method for monitoring catalytic activity of a catalytic converter through which exhaust gas can flow in an exhaust system of an internal combustion engine, which comprises: measuring a temperature at least at two temperature measuring sensors of which at least one is disposed in the catalytic converter and which sensors are spaced apart in flow direction; periodically repeatedly determining a temperature measuring variable from signals issued by the sensors during operation of the engine with an engine monitoring system; averaging the temperature measuring variable over a sufficiently long period of engine operation to form a mean temperature value which is substantially unaffected by short-term load conditions; comparing the mean temperature value with a predetermined limit value; and indicating if a mean temperature value does not correspond to the limit value and ascertaining a catalytic activity of the catalytic converter.
Claim 3
Dependent Claim
25 words
The method according to claim 1, which comprises observing the temperature measuring variable over a period encompassing at least approximately 10 hours of engine operation.
Claim 4
Dependent Claim
28 words
The method according to claim 1, which comprises observing the temperature measuring variable over a period encompassing between approximately 100 hours and approximately 1000 hours of engine operation.
Claim 5
Dependent Claim
80 words
The method according to claim 1, which comprises: a) observing the temperature measuring variable over a given period of time; b) periodically determining the temperature measuring variable at time intervals being substantially shorter than the given observation period and recording the temperature measuring variable in a memory of a multichannel analyzer belonging to the engine monitoring system; c) forming the mean temperature value from the contents of the memory, after the observation period has elapsed; and d) erasing the memory.
Claim 6
Dependent Claim
23 words
The method according to claim 1, which comprises forming the mean temperature value by integrating the temperature measuring variable over an observation period.
Claim 7
Dependent Claim
54 words
The method according to claim 1, which comprises: a) forming further measuring variables characterizing the operating state of the engine, during operation of the engine; b) forming further mean values by observing the further measuring variables over an observation period; and c) determining the limit value while taking the further mean values into account.
Claim 8
Dependent Claim
51 words
The method according to claim 6, which comprises: a) periodically recording and storing the further measuring variables in memory in a multidimensional multichannel analyzer; b) forming the further mean value from the contents of the multidimensional multichannel analyzer, after the observation period has elapsed; and c) erasing the multidimensional multichannel analyzer.
Claim 9
Dependent Claim
33 words
The method according to claim 7, which comprises periodically recording the temperature measuring variable jointly with the further measuring variables and storing the temperature measuring variable in memory in the multidimensional multichannel analyzer.
Claim 10
Independent Claim
164 words
A method for monitoring catalytic activity of a catalytic converter through which exhaust gas can flow in an exhaust system of an internal combustion engine, which comprises: measuring a temperature at least at two temperature measuring sensors of which at least one is disposed in close proximity of the catalytic converter for measuring the temperature of an exhaust gas flowing through the catalytic converter, and which at least two sensors are spaced apart in a flow direction of the exhaust gas; periodically repeatedly determining a temperature measuring variable from signals issued by the sensors during operation of the engine with an engine monitoring system; averaging the temperature measuring variable over a sufficiently long period of engine operation to form a mean temperature value which is substantially unaffected by short-term load conditions; comparing the mean temperature value with a predetermined limit value; and indicating if a mean temperature value does not correspond to the limit value and ascertaining a catalytic activity of the catalytic converter.
Claim 11
Independent Claim
164 words
A method for monitoring catalytic activity of a catalytic converter through which exhaust gas can flow in an exhaust system of an internal combustion engine, which comprises: measuring a temperature at least at two temperature measuring sensors of which at least one is disposed in close proximity of the catalytic converter for measuring the temperature of an exhaust gas flowing through the catalytic converter, and which at least two sensors are spaced apart in a flow direction of the exhaust gas; periodically repeatedly determining a temperature measuring variable from signals issued by the sensors during operation of the engine with an engine monitoring system; averaging the temperature measuring variable over a sufficiently long period of engine operation to form a mean temperature value which is substantially unaffected by short-term load conditions; comparing the mean temperature value with a predetermined limit value; and indicating if a mean temperature value does not correspond to the limit value and ascertaining a catalytic activity of the catalytic converter.
Claim 12
Dependent Claim
25 words
The method according to claim 9, which comprises observing the temperature measuring variable over a period encompassing at least approximately 10 hours of engine operation.
Claim 13
Dependent Claim
28 words
The method according to claim 9, which comprises observing the temperature measuring variable over a period encompassing at least approximately 100 hours and approximately 1000 of engine operation.
Claim 14
Dependent Claim
80 words
The method according to claim 9, which comprises: a) observing the temperature measuring variable over a given period of time; b) periodically determining the temperature measuring variable at time intervals being substantially shorter than the given observation period and recording the temperature measuring variable in a memory of a multichannel analyzer belonging to the engine monitoring system; c) forming the mean temperature value from the contents of the memory, after the observation period has elapsed; and d) erasing the memory.
Claim 15
Dependent Claim
23 words
The method according to claim 9, which comprises forming the mean temperature value by integrating the temperature measuring variable over an observation period.
Claim 16
Dependent Claim
54 words
The method according to claim 9, which comprises: a) forming further measuring variables characterizing the operating state of the engine, during operation of the engine; b) forming further mean values by observing the further measuring variables over an observation period; and c) determining the limit value while taking the further mean values into account.
Claim 17
Dependent Claim
51 words
The method according to claim 14, which comprises: a) periodically recording and storing the further measuring variables in memory in a multidimensional multichannel analyzer; b) forming the further mean value from the contents of the multidimensional multichannel analyzer, after the observation period has elapsed; and c) erasing the multidimensional multichannel analyzer.
Claim 18
Dependent Claim
33 words
The method according to claim 15, which comprises periodically recording the temperature measuring variable jointly with the further measuring variables and storing the temperature measuring variable in memory in the multidimensional multichannel analyzer.
References Cited (Backward Citations)
US3766536A
Cited
DE2346425A1
Cited
DE2406073A1
Cited
DE2444334A1
Cited
DE2643739A1
Cited
JPS5389482A
Cited
US4122720A
Cited
JPS55110941A
Cited
US4617794A
Cited
DE3516981A1
Cited
EP0223058A1
Cited
EP0236659A1
Cited
EP0245738A1
Cited
EP0245737B1
Cited
DE3710268A1
Cited
DE3811732A1
Cited
DE3841685A1
Cited
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| 3.5 Years (Year 4) | 1997-08-22 | 1998-02-21 | 1998-08-23 | $2000.00 | Window Closed / Lapsed |
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