EP0442648A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of and apparatus for monitoring operation of a catalytic converter
Assignee: ZF International UK Ltd
•
Filing: 1991-02-05
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Granted: —
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Expires: 2011-02-05
Abstract
Abstract Sensors (3, 4) measure the temperatures of exhaust gas upstream and downstream of a catalytic converter (1) for internal combustion engine exhaust gas. The difference (5) between the temperatures is multiplied (6) by the rate of mass flow of exhaust gas and the result is integrated (7) or low pass filtered to provide a measure of converter operation. Alternatively, the multiplication is omitted and the difference between the temperatures is integrated or filtered.
Inventors
- 👤 Benjamin James Bradshaw
- 👤 Russell Wilson Jones
- 👤 David Williams
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 21:56
CPC Classifications
F; F01; F01N; F01N11/00; F01N11/002; G; G01; G01K; G01K17/00; G01K17/06; G01K17/08; G01K17/10; G01K3/00; G01K3/08; G01K3/14; F01N2550/00; F01N2550/02; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
94 words
An apparatus for monitoring operation of a catalytic converter for exhaust gas of an internal combustion engine, comprising a first temperature sensor for measuring the entry temperature of exhaust gas entering the converter, a second temperature sensor for measuring the exit temperature of exhaust gas leaving the converter, and differencing means for forming the difference between the exit temperature and the entry temperature, characterised by processing means (7) for processing the difference to provide a measure of operation of the converter (1), the processing means (7) having a transfer function including an integral term.
Claim 2
Dependent Claim
17 words
An apparatus as claimed in Claim 1, characterised in that the processing means comprises an integrator (7).
Claim 3
Dependent Claim
19 words
An apparatus as claimed in Claim 1, characterised in that the processing means (7) comprises a low pass filter.
Claim 4
Independent Claim
44 words
An apparatus as claimed in any one of the preceding claims, characterised by a multiplier (6) connected between the differencing means (5) and the processing means (7) and arranged to form the product of the difference and the rate of exhaust gas mass flow.
Claim 5
Independent Claim
26 words
An apparatus as claimed in any one of the preceding claims, characterised by a comparator (10) for comparing the measure of converter operation with a threshold.
Claim 6
Independent Claim
33 words
An apparatus as claimed in any one of the preceding claims, characterised by enabling means (11) for enabling monitoring of the operation of the converter only during predetermined operational modes of the engine.
Claim 7
Dependent Claim
30 words
An apparatus as claimed in Claim 6, characterised in that the enabling means (11) is arranged to enable monitoring only when the engine temperature is greater than a predetermined temperature.
Claim 8
Dependent Claim
27 words
An apparatus as claimed in Claim 6 or 7, characterised in that the enabling means (11) is arranged to enable monitoring only at substantially constant engine speed.
Claim 9
Independent Claim
44 words
An apparatus for monitoring operation of a catalytic convector for exhaust gas of an internal combustion engine, characterised by means (3-7) for determining the difference between heat removed from the converter (1) by exhaust gas and heat supplied to the converter by exhaust gas.
Claim 10
Independent Claim
76 words
A method of monitoring operation of a catalytic converter (1) for exhaust gas of an internal combustion engine, comprising the steps of measuring the entry temperature of exhaust gas entering the converter (1), measuring the exit temperature of exhaust gas leaving the converter (1), forming the difference between the exit temperature and the entry temperature, and subjecting the difference to processing by a transfer function having an integral term to provide a measure of converter operation.
Claim 11
Dependent Claim
14 words
A method as claimed in Claim 10, characterised in that the processing comprises integrating.
Claim 12
Dependent Claim
16 words
A method as claimed in Claim 10, characterised in that the processing comprises low pass filtering.
Claim 13
Independent Claim
30 words
A method as claimed in any one of the preceding claims, characterised in that the difference is multiplied by the rate of exhaust gas mass flow before the processing step.
Claim 14
Independent Claim
22 words
A method as claimed in any one of the preceding claims, characterised by comparing the measure of converter operation with a threshold.
Claim 15
Independent Claim
27 words
A method as claimed in any one of the preceding claims, characterised by enabling monitoring of the converter (1) only during predetermined operational modes of the engine.
Claim 16
Dependent Claim
22 words
A method as claimed in Claim 15, characterised by enabling monitoring only when the engine temperature is greater than a predetermined temperature.
Claim 17
Dependent Claim
19 words
A method as claimed in Claim 15 or 16, characterised by enabling monitoring only at substantially constant engine speed.
Claim 18
Independent Claim
42 words
A method of monitoring operation of a catalytic converter (1) for exhaust gas of an internal combustion engine, comprising measuring the difference between heat removed from the convertor (1) by exhaust gas and heat supplied to the converter (1) by exhaust gas.
References Cited (Backward Citations)
No citation records indexed.
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