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Patent US5709080A successfully refreshed from Google Patents.
US5709080A
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Leak detection method and apparatus for an exhaust purification system
Assignee: Caterpillar Inc
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Filing: 1996-03-15
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Granted: 1998-01-20
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Expires: 2016-03-15
Abstract
Abstract A method and apparatus for determining a leak in an HC fluid supply of an exhaust purification system for an engine is disclosed. The fluid supply includes an injector that injects an amount of a NOx reducing fluid, a tank that holds the NOx reducing fluid, and a pump that pressurizes the NOx reducing fluid. The system fluid pressure is read before and after the pump is shut off. The pressure readings are compared and the exhaust purification system is turned off in response to the difference between the pressure readings being greater than a predetermined value.
Inventors
- 👤 Amit Arora
- 👤 Ward L. Bivens
- 👤 Darren L. Krahn
- 👤 Randy N. Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:48
CPC Classifications
F; F01; F01N; F01N11/00; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/20; F01N3/206; F01N3/2066; F01N2550/00; F01N2550/05; F01N2550/06; F01N2570/00; F01N2570/14; F01N2610/00; F01N2610/03; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
113 words
A method for determining a leak in an engine exhaust purification system containing a NOx reducing fluid, the system including an injector that injects an amount of a NOx reducing fluid, a tank that holds the NOx reducing fluid, and a pump that pressurizes the NOx reducing fluid, the method comprising the steps of: monitoring the system fluid pressure while the pump is operating; shutting the pump off for a predetermined time period and thereafter monitoring the system fluid pressure; comparing the pressure difference while the pump is operating and while the pump is shut off; and turning the system off in response to the pressure difference being greater than a predetermined value.
Claim 2
Independent Claim
113 words
A method for determining a leak in an engine exhaust purification system containing a NOx reducing fluid, the system including an injector that injects an amount of a NOx reducing fluid, a tank that holds the NOx reducing fluid, and a pump that pressurizes the NOx reducing fluid, the method comprising the steps of: monitoring the system fluid pressure while the pump is operating; shutting the pump off for a predetermined time period and thereafter monitoring the system fluid pressure; comparing the pressure difference while the pump is operating and while the pump is shut off; and turning the system off in response to the pressure difference being greater than a predetermined value.
Claim 3
Dependent Claim
29 words
A method, as set forth in claim 1, including the step of shutting the pump off for a period of 30 seconds and thereafter monitoring the system fluid pressure.
Claim 4
Dependent Claim
27 words
A method, as set forth in claim 2, wherein the fluid supply system is turned off in response to the pressure difference being greater than 100 kPa.
Claim 5
Dependent Claim
39 words
A method, as set forth in claim 3, wherein the exhaust purification system includes a system leak light and including the step of illuminating the system leak light in response to the pressure difference being greater than 100 kPa.
Claim 6
Dependent Claim
33 words
A method, as set forth in claim 4, including the step of repeating the steps of claims 1-4 when the engine is first started and every eight hours while the engine is operating.
Claim 7
Independent Claim
109 words
An apparatus for determining a leak in an engine exhaust purification system containing a NOx reducing fluid, the system including an injector that injects an amount of a NOx reducing fluid, a tank that holds the NOx reducing fluid, and a pump that pressurizes the NOx reducing fluid, comprising: means for detecting the system fluid pressure and producing a pressure signal; means for shutting the pump off for a predetermined time period; means for reading the pressure signal before and after the pump being shut off, comparing the two pressure readings, and turning the system off in response to the pressure reading differential being greater than a predetermined value.
Claim 8
Independent Claim
109 words
An apparatus for determining a leak in an engine exhaust purification system containing a NOx reducing fluid, the system including an injector that injects an amount of a NOx reducing fluid, a tank that holds the NOx reducing fluid, and a pump that pressurizes the NOx reducing fluid, comprising: means for detecting the system fluid pressure and producing a pressure signal; means for shutting the pump off for a predetermined time period; means for reading the pressure signal before and after the pump being shut off, comparing the two pressure readings, and turning the system off in response to the pressure reading differential being greater than a predetermined value.
Claim 9
Dependent Claim
20 words
An apparatus, as set forth in claim 6, wherein the pump is shut off for a period of 30 seconds.
Claim 10
Dependent Claim
28 words
An apparatus, as set forth in claim 7, wherein the fluid supply system is turned off in response to the pressure reading differential being greater than 100 kPa.
Claim 11
Dependent Claim
39 words
An apparatus, as set forth in claim 8, wherein the exhaust purification system includes a system leak light and including means for illuminating the system leak light in response to the pressure reading differential being greater than 100 kPa.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-01-19 | 2001-07-21 | 2002-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-01-19 | 2005-07-21 | 2006-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-01-19 | 2009-07-21 | 2010-01-20 | $7700.00 | Window Closed / Lapsed |