Patent US5604306A successfully refreshed from Google Patents.
US5604306A
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Apparatus and method for detecting a plugged air filter on an engine
Assignee: Caterpillar Inc
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Filing: 1995-07-28
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Granted: 1997-02-18
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Expires: 2015-07-28
Abstract
Abstract An apparatus and method for detecting a plugged condition of an air filter uses a computer based model of the air restriction.
Inventors
- 👤 David R. Schricker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:52
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/42; B01D46/44; B01D46/446; B01D46/0084; B01D46/0086; B01D46/448; F; F02; F02M; F02M35/00; F02M35/02; F02M35/08; F02M35/09; G; G01; G01M; G01M13/00; Y; Y10; Y10S; Y10S116/00; Y10S116/25
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
210 words
An apparatus for detecting a plugged air filter on an engine having an intake manifold, including: means for sensing filtered air pressure and responsively producing a filtered air pressure signal; means for sensing intake manifold pressure and responsively producing an intake manifold pressure signal; means for sensing intake manifold temperature and responsively producing an intake manifold temperature signal; means for receiving said intake manifold pressure and temperature signals, responsively determining a density of air at the intake manifold, and producing an air density signal; means for detecting a low load condition of the engine, receiving said air density signal, responsively determining a mass flow of air through the engine at said low load condition and producing a low load mass flow air signal; means for detecting a high load condition of the engine, receiving said air density signal, responsively determining a mass flow of air through the engine at said high load condition and producing a high load mass flow air signal; means for receiving said low load and high load condition mass air flow signals and said filtered air pressure signal, responsively determining a restriction value, and responsively producing a restriction signal; and means for receiving said restriction signal and responsively detecting a plugged condition of the air filter.
Claim 2
Independent Claim
210 words
An apparatus for detecting a plugged air filter on an engine having an intake manifold, including: means for sensing filtered air pressure and responsively producing a filtered air pressure signal; means for sensing intake manifold pressure and responsively producing an intake manifold pressure signal; means for sensing intake manifold temperature and responsively producing an intake manifold temperature signal; means for receiving said intake manifold pressure and temperature signals, responsively determining a density of air at the intake manifold, and producing an air density signal; means for detecting a low load condition of the engine, receiving said air density signal, responsively determining a mass flow of air through the engine at said low load condition and producing a low load mass flow air signal; means for detecting a high load condition of the engine, receiving said air density signal, responsively determining a mass flow of air through the engine at said high load condition and producing a high load mass flow air signal; means for receiving said low load and high load condition mass air flow signals and said filtered air pressure signal, responsively determining a restriction value, and responsively producing a restriction signal; and means for receiving said restriction signal and responsively detecting a plugged condition of the air filter.
Claim 3
Dependent Claim
61 words
An apparatus, as set forth in claim 1, wherein said restriction signal producing means includes means for determining a low load filtered air pressure and a high load filtered air pressure at said low load and high load conditions, respectively, and wherein said restriction value is a function of said low load filtered air pressure and high load filtered air pressure.
Claim 4
Dependent Claim
26 words
An apparatus, as set forth in claim 1, wherein said detecting means includes means for capturing said restriction signal and storing said restriction signal over time.
Claim 5
Dependent Claim
15 words
An apparatus, as set forth in claim 2, wherein said stored restriction signal is filtered.
Claim 6
Dependent Claim
35 words
An apparatus, as set forth in claim 2, wherein said detecting means includes means for comparing said captured restriction signal to a preset value and wherein said plugged condition being defined by said preset value.
Claim 7
Dependent Claim
33 words
An apparatus, as set forth in claim 2, wherein said plugged condition is defined by a predetermined trend, said plugged condition being detected by comparing said predetermined trend to said stored restriction signals.
Claim 8
Independent Claim
197 words
A method for detecting a plugged air filter on an engine having an intake manifold, including the steps of: sensing filtered air pressure and responsively producing a filtered air pressure signal; sensing intake manifold pressure and responsively producing an intake manifold pressure signal; sensing intake manifold temperature and responsively producing an intake manifold temperature signal; receiving said intake manifold pressure and temperature signals, responsively determining a density of air at the intake manifold, and producing an air density signal; detecting a low load condition of the engine, receiving said air density signal, responsively determining a mass flow of air through the engine at said low load condition and producing a low load mass flow air signal; detecting a high load condition of the engine, receiving said air density signal, responsively determining a mass flow of air through the engine at said high load condition and producing a high load mass flow air signal; receiving said low load and high load condition mass air flow signals and said filtered air pressure signal, responsively determining a restriction value, and responsively producing a restriction signal; and receiving said restriction signal and responsively detecting a plugged condition of the air filter.
Claim 9
Independent Claim
197 words
A method for detecting a plugged air filter on an engine having an intake manifold, including the steps of: sensing filtered air pressure and responsively producing a filtered air pressure signal; sensing intake manifold pressure and responsively producing an intake manifold pressure signal; sensing intake manifold temperature and responsively producing an intake manifold temperature signal; receiving said intake manifold pressure and temperature signals, responsively determining a density of air at the intake manifold, and producing an air density signal; detecting a low load condition of the engine, receiving said air density signal, responsively determining a mass flow of air through the engine at said low load condition and producing a low load mass flow air signal; detecting a high load condition of the engine, receiving said air density signal, responsively determining a mass flow of air through the engine at said high load condition and producing a high load mass flow air signal; receiving said low load and high load condition mass air flow signals and said filtered air pressure signal, responsively determining a restriction value, and responsively producing a restriction signal; and receiving said restriction signal and responsively detecting a plugged condition of the air filter.
Claim 10
Dependent Claim
68 words
A method, as set forth in claim 7, including the steps of: determining a low load filtered air pressure at said low load condition, and determining a high load filtered air pressure at said high load condition; and wherein said restriction signal is a function of said low load and high load condition mass air flow signals and said low load and high load condition filtered air pressures.
Claim 11
Dependent Claim
23 words
A method, as set forth in claim 7, wherein said step of detecting includes the step of storing said restriction signal over time.
Claim 12
Dependent Claim
16 words
A method as set forth in claim 7, including the step of filtering said restriction signal.
Claim 13
Dependent Claim
35 words
A method, as set forth in claim 7, wherein said detecting step includes the of for comparing said captured restriction signal to a preset value, wherein said plugged condition being defined by said preset value.
Claim 14
Dependent Claim
32 words
A method, as set forth in claim 7, wherein said plugged condition is defined by a predetermined trend, and including the step of comparing said predetermined trend to said stored restriction signals.
References Cited (Backward Citations)
US3721120A
Cited
US4964318A
Cited
US4254731A
Cited
US4445456A
Cited
US4369728A
Cited
US4368705A
Cited
US4604701A
Cited
US4621335A
Cited
US4630189A
Cited
US4616616A
Cited
EP0142101A2
Cited
US4671107A
Cited
US4736715A
Cited
EP0231155A1
Cited
US4901530A
Cited
US4882905A
Cited
US4953110A
Cited
US5010487A
Cited
US5205125A
Cited
US5377112A
Cited
US5401285A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-02-18 | 2000-08-19 | 2001-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-18 | 2004-08-19 | 2005-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-18 | 2008-08-19 | 2009-02-18 | $7700.00 | Window Closed / Lapsed |