US3818880A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas recirculation control for internal combustion engines
Assignee: Old Carco LLC
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Filing: 1972-08-02
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Granted: 1974-06-25
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Expires: 1992-08-02
Abstract
Abstract An exhaust gas recirculation (EGR) control arrangement for internal combustion engines incorporating vacuum relief means for dumping an output EGR signal, which ordinarily maintains an EGR valve in an ''''open'''' condition, whenever a venturi control signal achieves a predetermined relationship to the value of engine manifold vacuum, thereby causing the EGR valve to close.
Inventors
- 👤 G Dawson
- 👤 R Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:42
CPC Classifications
F; F02; F02M; F02M26/00; F02M26/52; F02M26/55; F02M26/56
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
250 words
An exhaust gas recirculation control system for motor vehicles driven by internal combustion engines whereby exhaust gas is recirculated to the engine combustion chambers to lower exhaust gas emissions of NOx while vehicle driveability is substantially maintained, the system comprising: a vacuum operated exhaust gas recirculation valve; vacuum reservoir means for providing an operating control vacuum to the exhaust gas recirculating valve; engine manifold vacuum source means operable by way of a check valve means to provide vacuum to the vacuum reservoir means during engine operation; control means responsive to a vacuum control signal and operable to modulate, in accordance with the vacuum control signal, the operating control vacuum provided to the exhaust gas recirculating valve by the vacuum reservoir means; carburetor venturi vacuum source means operable to provide a carburetor venturi vacuum control signal to the control means during engine operation thereby effecting the operation of the control means and the modulation of the operating vacuum provided to the exhaust gas recirculating valve during engine operation, and vacuum relief means operable to vent the vacuum reservoir means to engine manifold vacuum level whereupon the operating vacuum is no longer provided, the relief means including operating means controlled by and responsive to both venturi vacuum and manifold vacuum for opening the vacuum relief means and venting the vacuum reservoir means when the venturi vacuum achieves a predetermined relationship to the manifold vacuum level during which time exhaUst gas recirculation is terminated due to closure of the exhaust gas recirculation valve.
Claim 2
Dependent Claim
250 words
An exhaust gas recirculation control system for motor vehicles driven by internal combustion engines whereby exhaust gas is recirculated to the engine combustion chambers to lower exhaust gas emissions of NOx while vehicle driveability is substantially maintained, the system comprising: a vacuum operated exhaust gas recirculation valve; vacuum reservoir means for providing an operating control vacuum to the exhaust gas recirculating valve; engine manifold vacuum source means operable by way of a check valve means to provide vacuum to the vacuum reservoir means during engine operation; control means responsive to a vacuum control signal and operable to modulate, in accordance with the vacuum control signal, the operating control vacuum provided to the exhaust gas recirculating valve by the vacuum reservoir means; carburetor venturi vacuum source means operable to provide a carburetor venturi vacuum control signal to the control means during engine operation thereby effecting the operation of the control means and the modulation of the operating vacuum provided to the exhaust gas recirculating valve during engine operation, and vacuum relief means operable to vent the vacuum reservoir means to engine manifold vacuum level whereupon the operating vacuum is no longer provided, the relief means including operating means controlled by and responsive to both venturi vacuum and manifold vacuum for opening the vacuum relief means and venting the vacuum reservoir means when the venturi vacuum achieves a predetermined relationship to the manifold vacuum level during which time exhaUst gas recirculation is terminated due to closure of the exhaust gas recirculation valve.
Claim 3
Dependent Claim
25 words
The system according to claim 1 wherein the vacuum reservoir means includes said check valve means for trapping vacuum achieved at low speeds and decelerations.
Claim 4
Dependent Claim
24 words
The system according to claim 1 wherein the relief means is connected between the vacuum reservoir means and the engine manifold vacuum source means.
Claim 5
Dependent Claim
51 words
The system according to claim 1 wherein the engine manifold vacuum source means comprises a conduit communicating at one end with the vacuum reservoir means and at another end it is adapted for connection to an internal combustion engine at a tap-in point suitable for interfacing with the engine manifold vacuum.
Claim 6
Dependent Claim
23 words
The system according to claim 1 wherein the control means is connected between the vacuum reservoir means and the exhaust gas recirculation valve.
Claim 7
Dependent Claim
49 words
The system according to claim 1 wherein the carburetor venturi vacuum source means comprises a conduit communicating at one end with control means and at another end it is adapted for connection to an internal combustion engine carburetor at a tap-in point for interfacing with the carburetor venturi vacuum.
Claim 8
Dependent Claim
32 words
The system according to claim 1 wherein the vacuum relief means is normally closed by the manifold vacuum and opened by the venturi vacuum when it approaches or exceeds the manifold vacuum.
Claim 9
Dependent Claim
218 words
An exhaust gas recirculation control system for motor vehicles driven by internal combustion engines whereby exhaust gas is recirculated to the engine combustion chambers to lower exhaust gas emissions of NOx, the system comprising: engine power means operable to provide vacuum output means adapted for connection to an exhaust gas recirculation valve; control means connected to the vacuum output means to control the vacuum thereof in accordance with a vacuum control signal; vacuum reservoir means connected to the control means for providing a vacuum thereto to be controlled by the vacuum control signal; vacuum input means adapted for connection to a source of input vacuum and communicating by copy of a check valve means with the vacuum reservoir means; relief means communicating between the vacuum reservoir means and the vacuum input means for venting the former to the latter, the relief means being normally closed by the input vacuum, and vacuum control means adapted for connection to a source of control vacuum and communicating with the control means for modulating the vacuum output provided thereby for the vacuum output means the relief means is also being connected to the source of control vacuum for opening it when the control vacuum achieves a predetermined relationship to the input vacuum, said source of control vacuum providing said vacuum control signal.
Claim 10
Dependent Claim
218 words
An exhaust gas recirculation control system for motor vehicles driven by internal combustion engines whereby exhaust gas is recirculated to the engine combustion chambers to lower exhaust gas emissions of NOx, the system comprising: engine power means operable to provide vacuum output means adapted for connection to an exhaust gas recirculation valve; control means connected to the vacuum output means to control the vacuum thereof in accordance with a vacuum control signal; vacuum reservoir means connected to the control means for providing a vacuum thereto to be controlled by the vacuum control signal; vacuum input means adapted for connection to a source of input vacuum and communicating by copy of a check valve means with the vacuum reservoir means; relief means communicating between the vacuum reservoir means and the vacuum input means for venting the former to the latter, the relief means being normally closed by the input vacuum, and vacuum control means adapted for connection to a source of control vacuum and communicating with the control means for modulating the vacuum output provided thereby for the vacuum output means the relief means is also being connected to the source of control vacuum for opening it when the control vacuum achieves a predetermined relationship to the input vacuum, said source of control vacuum providing said vacuum control signal.
References Cited (Backward Citations)
US3739797A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |