US3885540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-fuel ratio control system for a combustion engine
Assignee: Ford Motor Co
•
Filing: 1974-06-10
•
Granted: 1975-05-27
•
Expires: 1994-06-10
Abstract
Abstract Improved air-fuel ratio control system for a combustion engine. The system utilizes a sensor, responsive to the partial pressure of oxygen in a gaseous mixture to which the sensor is exposed, to control the ratio of air to fuel supplied to the engine. Prior art systems located the sensor directly in the stream of exhaust gases emanating from the engine. According to the present invention, the engine has an intake conduit, an exhaust conduit and a third conduit interconnecting the intake and exhaust conduits to permit a portion of the engine exhaust gases to be conducted from the exhaust conduit to the intake conduit. The sensor is located in the third conduit for exposure to the gaseous medium therein. Air is admitted, upstream of the sensor, to the third conduit.
Inventors
- 👤 Henry L Stadler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:10
CPC Classifications
F; F02; F02M; F02M26/00; F02M26/45; F02M26/46; F02M26/13; F02M26/36; F02D; F02D41/00; F02D41/0025; F02D41/0047; F02D41/0065; F02M26/14
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
178 words
In a system which utilizes a sensor responsive to the partial pressure of oxygen to control the ratio of air to fuel supplied to a combustion engine, said engine having an intake conduit through which air enters the engine, having means for mixing the fuel with the air which enters said engine through said intake conduit and having an exhaust conduit for conducting exhaust gases from said engine, the improvement which comprises: a third conduit interconnecting said intake conduit and said exhaust conduit, said third conduit permitting a portion of said exhaust gases of said engine to be conducted from said exhaust conduit to said intake conduit, said sensor being located for exposure to the gaseous medium in said third conduit to sense the partial pressure of oxygen in said gaseous medium, and means for modifying the partial pressure of oxygen in said portion of the exhaust gases of said engine to produce a partial pressure of oxygen in said gaseous medium different than the partial pressure of oxygen in said exhaust gases flowing through said exhaust conduit.
Claim 2
Dependent Claim
178 words
In a system which utilizes a sensor responsive to the partial pressure of oxygen to control the ratio of air to fuel supplied to a combustion engine, said engine having an intake conduit through which air enters the engine, having means for mixing the fuel with the air which enters said engine through said intake conduit and having an exhaust conduit for conducting exhaust gases from said engine, the improvement which comprises: a third conduit interconnecting said intake conduit and said exhaust conduit, said third conduit permitting a portion of said exhaust gases of said engine to be conducted from said exhaust conduit to said intake conduit, said sensor being located for exposure to the gaseous medium in said third conduit to sense the partial pressure of oxygen in said gaseous medium, and means for modifying the partial pressure of oxygen in said portion of the exhaust gases of said engine to produce a partial pressure of oxygen in said gaseous medium different than the partial pressure of oxygen in said exhaust gases flowing through said exhaust conduit.
Claim 3
Dependent Claim
27 words
The imroved system of claim 1 wherein said third conduit includes means for restricting the flow of exhaust gases from said exhaust conduit into said third conduit.
Claim 4
Dependent Claim
44 words
The improved system of claim 2 wherein said means for modifying said partial pressure of oxygen includes means for admitting a gaseous component into said third conduit and valve means for variably controlling the amount of said gaseous component admitted to said third conduit.
Claim 5
Dependent Claim
161 words
In a system which utilizes a sensor responsive to the partial pressure of oxygen to control the ratio of air to fuel supplied to a combustion engine, said engine having an intake conduit through which air enters the engine, having means for mixing fuel with the air which enters said engine through said intake conduit and having an exhaust conduit for conducting exhaust gases from said engine, the improvement which comprises: a third conduit interconnecting said intake conduit and said exhaust conduit, said third conduit permitting a portion of the exhaust gases of said engine to be conducted from said exhaust conduit to said intake conduit, said sensor being located for exposure to the gaseous medium in said third conduit to sense the partial pressure of oxygen in said gaseous medium, and means for admitting air to said third conduit at a location upstream of said sensor location when exhaust gases are flowing from said exhaust conduit to said intake conduit.
Claim 6
Dependent Claim
161 words
In a system which utilizes a sensor responsive to the partial pressure of oxygen to control the ratio of air to fuel supplied to a combustion engine, said engine having an intake conduit through which air enters the engine, having means for mixing fuel with the air which enters said engine through said intake conduit and having an exhaust conduit for conducting exhaust gases from said engine, the improvement which comprises: a third conduit interconnecting said intake conduit and said exhaust conduit, said third conduit permitting a portion of the exhaust gases of said engine to be conducted from said exhaust conduit to said intake conduit, said sensor being located for exposure to the gaseous medium in said third conduit to sense the partial pressure of oxygen in said gaseous medium, and means for admitting air to said third conduit at a location upstream of said sensor location when exhaust gases are flowing from said exhaust conduit to said intake conduit.
Claim 7
Dependent Claim
26 words
The improvement of claim 4 wherein said third conduit includes means for restricting the flow of exhaust gases from said exhaust conduit into said third conduit.
Claim 8
Dependent Claim
30 words
The improved system of claim 4 wherein said means for admitting air into said third conduit includes valve means for variably controlling the flow of air into sAid third conduit.
Claim 9
Dependent Claim
29 words
The improved system of claim 6 wherein said sensor is comprised of a solid electrolyte one side of which is exposed to said gaseous medium in said third conduit.
Claim 10
Dependent Claim
13 words
The improved system of claim 7 wherein said solid electrolyte is zirconium dioxide.
Claim 11
Dependent Claim
14 words
The improved system of claim 6 wherein said sensor is comprised of titanium dioxide.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |