US3915134A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas recirculation system for internal combustion engines
Assignee: Dana Inc
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Filing: 1974-03-04
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Granted: 1975-10-28
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Expires: 1994-03-04
Abstract
Abstract Apparatus for electronically controlling exhaust gas recirculation in an internal combustion diesel engine to reduce nitrogen oxide emissions. An exhaust gas recirculation control valve is driven by a feedback circuit which compares the valve position with the engine load. A maximum amount of exhaust gas is recirculated under a no-load condition. As the load increases to 100%, the amount of recirculated exhaust gas is decreased down to zero percent. The amount of recirculated exhaust gas also may be affected by the engine speed to minimize smoke in the engine exhaust.
Inventors
- 👤 Richard N Young
- 👤 Larry O Gray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:44
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/0025; F02D41/0047; F02D41/0077; F02B; F02B1/00; F02B1/02; F02B1/04; F02B3/00; F02B3/06; F02D41/005; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
117 words
For an internal combustion engine having an air intake and an exhaust, an exhaust gas emission control system comprising, in combination, valve means for selectively recirculating a portion of the exhaust gas to the air intake, said valve means moving between a first position wherein a predetermined maximum amount of the exhaust gas is recirculated and a second position wherein a predetermined minimum amount of the exhaust gas is recirculated, means for generating an electric signal indicative of a load on the engine, and electrical means positioning said valve means at predetermined intermediate positions between said first and second positions in response to such signal for reducing the oxides of nitrogen present in the engine exhaust gas.
Claim 2
Dependent Claim
117 words
For an internal combustion engine having an air intake and an exhaust, an exhaust gas emission control system comprising, in combination, valve means for selectively recirculating a portion of the exhaust gas to the air intake, said valve means moving between a first position wherein a predetermined maximum amount of the exhaust gas is recirculated and a second position wherein a predetermined minimum amount of the exhaust gas is recirculated, means for generating an electric signal indicative of a load on the engine, and electrical means positioning said valve means at predetermined intermediate positions between said first and second positions in response to such signal for reducing the oxides of nitrogen present in the engine exhaust gas.
Claim 3
Dependent Claim
67 words
An exhaust gas emission control system for an internal combustion engine, as set forth in claim 1, wherein said valve positioning means includes electrical control means for moving said valve means to said first position when the load on the engine is less than a predetermined value and for moving said valve means progressively towards said second position as the load progressively increases above such predetermined value.
Claim 4
Dependent Claim
42 words
An exhaust gas emission control system for an internal combustion engine, as set forth in claim 2, and further including means for moving said valve means to said first position when the engine is running at less than a predetermined minimum speed.
Claim 5
Dependent Claim
59 words
An exhaust gas emission control syStem for an internal combustion engine, as set forth in claim 3, and including means responsive to such electric signal and to the engine speed for moving said valve means to said second position when the load on the engine is less than a predetermined value and simultaneously the engine exceeds a predetermined speed.
Claim 6
Dependent Claim
47 words
An exhaust gas emission control system for an internal combustion engine, as set forth in claim 4, and further including means responsive to the speed of the engine for modifying said predetermined maximum amount of exhaust gas recirculated when said valve means is in said first position.
Claim 7
Dependent Claim
72 words
An exhaust gas emission control system for an internal combustion engine, as set forth in claim 1, including means for generating an electric signal indicative of the position of said valve means, and wherein said valve positioning means includes an electric motor connected to drive said valve means, means for comparing said engine load signal and said valve position signal and means responsive to such comparison for controlling said valve drive motor.
Claim 8
Dependent Claim
71 words
An exhaust gas emission control system for an internal combustion engine, as set forth in claim 6, wherein said valve positioning means further includes means responsive to said engine load signal for generating a third signal when the load on the engine is less than a predetermined minimum, and means for causing said valve drive motor to move said valve means to said first position in response to said third signal.
Claim 9
Dependent Claim
62 words
An exhaust gas emission control system for an internal combustion engine, as set forth in claim 6, and further including means for generating an electric signal when the engine is running at less than a predetermined minimum speed, and means for causing said valve drive motor to move said valve means to said first position in response to said minimum speed signal.
Claim 10
Dependent Claim
84 words
An exhaust gas emission control system for an internal combustion engine, as set forth in claim 6, and further including means for generating an electric signal when the load on the engine is less than a predetermined minimum, means for generating an electric signal when the engine speed exceeds a predetermined maximum, and means responsive to the simultaneous occurrence of said minimum load signal and said maximum speed signal for causing said valve drive motor to move said valve means to said second position.
Claim 11
Dependent Claim
60 words
An exhaust gas emission control system for an internal combustion engine, as set forth in claim 6, and further including means for generating a third electric signal when the engine exceeds a predetermined speed, and means responsive to said third signal for increasing said predetermined maximum amount of exhaust gas recirculated when said valve means is in said first position.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-27 | 1979-04-28 | 1979-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-27 | 1983-04-28 | 1983-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-27 | 1987-04-28 | 1987-10-28 | $7700.00 | Window Closed / Lapsed |