US3835827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust and gas recirculating system
Assignee: Ford Motor Co
•
Filing: 1973-01-29
•
Granted: 1974-09-17
•
Expires: 1993-01-29
Abstract
Abstract An exhaust gas recirculation system is disclosed employing a primary control valve having a vacuum operated servo mechanism for controlling the admission of recirculating gases. The servo mechanism is operated in response to a modulated vacuum signal derived principally from intake manifold vacuum. Modulation of the vacuum signal is achieved by three control means connected in series, one of which functions in response to a differential between carbureted venturi vacuum and the intake manifold vacuum, another control means operates to prevent communication of the vacuum signal to the servo mechanism during prolonged steady or nearly steady conditions of the engine, yet another control means is effective to prevent communication of the vacuum signal during wide-open throttle conditions of the engine carburetor.
Inventors
- 👤 J Wolgemuth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:10
CPC Classifications
F; F02; F02M; F02M26/00; F02M26/52; F02M26/55; F02M26/56
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
275 words
In an engine having an exhaust manifold, an intake system for inducting air and fuel through a metering venturi into an intake manifold of saId engine, an apparatus for recirculating exhaust gases comprising: a. a duct connecting said intake system and exhaust manifold, b. valve means interposed in said duct having a first control element normally biased to a closed position and a servo mechanism operable to overcome said bias for variably opening said valve means, said servo mechanism being connected to vacuum from said intake system, and c. first control means to modulate the connection of vacuum between said intake system and servo mechanism in accordance with pressure at said metering venturi, said first control means being movable in response to a differential pressure between intake manifold vacuum and venturi vacuum to modulate and limit the degree of intake system vacuum communicated to said servo mechanism, said first control means comprising a housing having a bore with stepped portions, a spool valve provided with differential lands slidable in respectively stepped portions of said bore, said bore having an inlet opening in communication with said servo mechanism and an outlet opening in communication with intake manifold vacuum, said outlet opening being arranged so as to be opened or closed by operable movement of said spool valve, the larger of said lands being subject to a force on one side thereof proportional to intake system air-flow vacuum tending to move said spool valve to an open position about said outlet opening and the other side of said larger land being subject to the intake manifold vacuum tending to urge said spool valve to a close position.
Claim 2
Dependent Claim
275 words
In an engine having an exhaust manifold, an intake system for inducting air and fuel through a metering venturi into an intake manifold of saId engine, an apparatus for recirculating exhaust gases comprising: a. a duct connecting said intake system and exhaust manifold, b. valve means interposed in said duct having a first control element normally biased to a closed position and a servo mechanism operable to overcome said bias for variably opening said valve means, said servo mechanism being connected to vacuum from said intake system, and c. first control means to modulate the connection of vacuum between said intake system and servo mechanism in accordance with pressure at said metering venturi, said first control means being movable in response to a differential pressure between intake manifold vacuum and venturi vacuum to modulate and limit the degree of intake system vacuum communicated to said servo mechanism, said first control means comprising a housing having a bore with stepped portions, a spool valve provided with differential lands slidable in respectively stepped portions of said bore, said bore having an inlet opening in communication with said servo mechanism and an outlet opening in communication with intake manifold vacuum, said outlet opening being arranged so as to be opened or closed by operable movement of said spool valve, the larger of said lands being subject to a force on one side thereof proportional to intake system air-flow vacuum tending to move said spool valve to an open position about said outlet opening and the other side of said larger land being subject to the intake manifold vacuum tending to urge said spool valve to a close position.
Claim 3
Dependent Claim
41 words
The apparatus as in claim 1, in which an accumulator is employed to maintain a predetermined level of intake manifold vacuum for introduction to said first control means during all conditions of operation except when said first control means is closed.
Claim 4
Dependent Claim
50 words
The apparatus as in claim 1, in which the smaller land is subjected to intake manifold vacuum urging said first control means to an open position and thereby maintaining a constant relationship between exhaust gas recirculation and intake system air-flow vacuum even during the closed position of said spool valve.
Claim 5
Dependent Claim
35 words
The apparatus as in claim 1, comprising in combination a third control means effective to prevent communication of said intake manifold vacuum with said servo mechanism during prolonged steady state cruising conditions of said engine.
Claim 6
Dependent Claim
56 words
The apparatus as in claim 1, in which said bias for said servo mechanism is calibrated to provide closure of said valve means at the highest vacuum encountered at wide-open throttle for said engine and said bias being adapted to meter a small amount of exhaust gas recirculation during throttle positions substantially adjacent to wide-open throttle.
Claim 7
Dependent Claim
52 words
The apparatus as in claim 1, in which there is further provided additional control means for controlling the communication of manifold intake vacuum to said servo mechanism, said additional control means being adapted to prevent communication of intake manifold vacuum to said servo mechanism during steady-state conditions of said carburetor air flow.
Claim 8
Dependent Claim
124 words
The apparatus as in claim 6, in which said additional control means comprises a housing having a bore with an inlet thereto in communication with said servo mechanism and an outlet thereof in communication with the inlet to said first control means, a valve element therein normally biased in a closed position preventing flow between said inlet and outlet and a land connecting with said element having opposite sides thereof normally subjected to intake manifold vacuum, and means for delaying the relief of intake manifold vacuum from either side of said land upon a change of intake manifold vacuum so that one side of said land will be effective to overcome said bias and open said second control means according to said predetermined delay.
References Cited (Backward Citations)
DE1601374A1
Cited
US3739797A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |