US5133184A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for monitoring the conversion ratio of a catalytic converter
Assignee: Volkswagen AG
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Filing: 1991-02-11
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Granted: 1992-07-28
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Expires: 2011-02-11
Abstract
Abstract To provide assured monitoring of the conversion ratio of an exhaust gas catalytic converter in the exhaust system of an internal combustion engine of a motor vehicle, at least one ignition suppression is generated and a preset quantity of fuel-air mixture is supplied during a deceleration phase of the engine and the difference in the temperatures at locations downstream and upstream with respect to the flow of exhaust gas through the catalytic converter is detected and evaluated.
Inventors
- 👤 Istvan Geiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:14
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/22; F01N3/222; F01N11/00; F01N11/002; F01N3/20; F01N3/2006; F01N3/24; F01N3/36; F01N9/00; G; G01; G01N; G01N25/00; G01N25/20; G01N25/22; G01N25/28; G01N25/30; F01N2550/00; F01N2550/02; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
91 words
A method for monitoring the conversion ratio of a catalytic converter disposed in the exhaust gas system of an internal combustion engine having spark ignition comprising causing at least one ignition suppression during a deceleration phase of operation of the internal combustion engine to cause a defined amount of unburned fuel-air mixture to be supplied to the catalytic converter, and comparing temperature values of the exhaust gases at spaced locations assuming different temperature values due to chemical reaction of said fuel-air mixture in the catalytic converter to provide a monitoring signal.
Claim 2
Independent Claim
91 words
A method for monitoring the conversion ratio of a catalytic converter disposed in the exhaust gas system of an internal combustion engine having spark ignition comprising causing at least one ignition suppression during a deceleration phase of operation of the internal combustion engine to cause a defined amount of unburned fuel-air mixture to be supplied to the catalytic converter, and comparing temperature values of the exhaust gases at spaced locations assuming different temperature values due to chemical reaction of said fuel-air mixture in the catalytic converter to provide a monitoring signal.
Claim 3
Dependent Claim
20 words
A method according to claim 1 wherein temperature values at locations upstream and downstream of the catalytic converter are compared.
Claim 4
Dependent Claim
27 words
A method according to claim 1 wherein the monitoring signal is produced only after the catalytic converter has reached its starting temperature even in an aged stage.
Claim 5
Dependent Claim
20 words
A method according to claim 1 wherein the monitoring signal is generated after each startup of the internal combustion engine.
Claim 6
Dependent Claim
16 words
A method according to claim 1 wherein the monitoring signal is generated at selected time intervals.
Claim 7
Dependent Claim
11 words
A method according to claim 1 including storing the monitoring signal.
Claim 8
Dependent Claim
84 words
Apparatus for monitoring the conversion ratio of a catalytic converter receiving exhaust gases from a sparkignited internal combustion engine comprising control means for causing ignition suppression, fuel mixture control means for controlling the supply of preset quantities of fuel and air to the engine including switch means for signalling a deceleration operation of the internal combustion engine, and temperature sensor means for detecting temperature conditions at spaced locations assuming different temperature values due to chemical reaction of said fuel-air mixture in the catalytic converter.
Claim 9
Dependent Claim
84 words
Apparatus for monitoring the conversion ratio of a catalytic converter receiving exhaust gases from a sparkignited internal combustion engine comprising control means for causing ignition suppression, fuel mixture control means for controlling the supply of preset quantities of fuel and air to the engine including switch means for signalling a deceleration operation of the internal combustion engine, and temperature sensor means for detecting temperature conditions at spaced locations assuming different temperature values due to chemical reaction of said fuel-air mixture in the catalytic converter.
Claim 10
Dependent Claim
32 words
Apparatus according to claim 7 wherein the switch means is a throttle flap switch for supplying an activation signal to the control means when the throttle flap is in the closed position.
Claim 11
Dependent Claim
41 words
Apparatus according to claim 7 including a throttle flap and bypass means for bypassing the throttle flap, and valve means in the bypass means responsive to the control means for controlling the quantity of air supplied to the internal combustion engine.
Claim 12
Dependent Claim
31 words
Apparatus according to claim 7 wherein the fuel mixture control means includes fuel injection nozzle means disposed downstream of a throttle flap in the air supply to the internal combustion engine.
Claim 13
Dependent Claim
22 words
Apparatus according to claim 10 wherein a fuel injection nozzle means is disposed between the catalytic converter and the internal combustion engine.
Claim 14
Dependent Claim
41 words
Apparatus according to claim 7 wherein the temperature sensor means is disposed upstream and downstream with respect to the flow of exhaust gases through the catalytic converter, and control means including difference signal means, signal differentiating means and signal memory means.
Claim 15
Dependent Claim
24 words
Apparatus according to claim 12 including temperature sensor means disposed in the upstream half of the catalytic converter to which exhaust gases are supplied.
References Cited (Backward Citations)
US4953351A
Cited
JPH0232106A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-07-28 | 1996-01-27 | 1996-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-28 | 2000-01-27 | 2000-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-28 | 2004-01-27 | 2004-07-28 | $7700.00 | Window Closed / Lapsed |