US4050429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Exhaust gas recirculation system for an automobile engine, including a high altitude compensator
Assignee: Toyota Motor Corp
•
Filing: 1976-05-24
•
Granted: 1977-09-27
•
Expires: 1996-05-24
Abstract
Abstract Disclosed is an exhaust gas recirculation system for an automobile engine, provided with a high altitude compensator. The high altitude compensator has an atmospheric chamber in which a first valve is adapted to open when the automobile reaches a predetermined altitude. The opening of this valve is enlarged in proportion to an increase in the altitude. The system also includes a second valve for exhaust gas recirculation control having a negative pressure chamber communicated with a first pressure sensing port opening to the carburetor. This valve controls the amount of the exhaust gas recycled into the intake side of the engine according to variation in the pressure of the negative pressure chamber. The system further includes a third or air flow switching valve having a negative pressure chamber communicated with a second pressure sensing port opening to the carburetor. This valve controls the amount of the air supplied into the exhaust side of the engine according to variation in the pressure of the negative pressure chamber. The atmospheric pressure chamber of the high altitude compensator is connected with both the negative pressure chambers of the second and third valves. The present system prevents a large decline in the engine power output, an unduly heavy generation of NO x and uncombusted HC and CO and thermal damage to the exhaust circuit of the engine during engine operation at a high altitude.
Inventors
- 👤 Ikuta Yasuhiro
- 👤 Shimo Hitomi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:41
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/18; F01N3/22; F01N3/227; F02; F02M; F02M26/00; F02M26/52; F02M26/55; F02M26/56; F02B; F02B1/00; F02B1/02; F02B1/04; Y; Y02; Y02A; Y02A50/00; Y02A50/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
163 words
In an exhaust gas recirculation system for an automobile engine, the improvement comprising: a first valve having a first atomspheric pressure chamber having means to receive an increasing air flow therethrough in proportion to an increase of the altitude; a second valve having a negative pressure chamber communicating with a first pressure sensing port opening to a carburetor, said second valve having means to control the amount of exhaust gas recycled into an intake manifold according to variation in the pressure of said negative pressure chamber; and a third valve having a negative pressure chamber communicating with a second pressure sensing port opening to said carburetor, said third valve having means to control the amount of air supplied into the exhaust side of said engine according to variation in the pressure of said negative pressure chamber of said third valve, wherein said atmospheric pressure chamber of said first valve is connected with both said negative pressure chambers of said second and third valves.
Claim 2
Dependent Claim
163 words
In an exhaust gas recirculation system for an automobile engine, the improvement comprising: a first valve having a first atomspheric pressure chamber having means to receive an increasing air flow therethrough in proportion to an increase of the altitude; a second valve having a negative pressure chamber communicating with a first pressure sensing port opening to a carburetor, said second valve having means to control the amount of exhaust gas recycled into an intake manifold according to variation in the pressure of said negative pressure chamber; and a third valve having a negative pressure chamber communicating with a second pressure sensing port opening to said carburetor, said third valve having means to control the amount of air supplied into the exhaust side of said engine according to variation in the pressure of said negative pressure chamber of said third valve, wherein said atmospheric pressure chamber of said first valve is connected with both said negative pressure chambers of said second and third valves.
Claim 3
Dependent Claim
98 words
The exhaust gas recirculation system as set forth in claim 1, wherein said first valve comprises: said first atmospheric pressure chamber; a second atmospheric pressure chamber separated from said first atmospheric pressure chamber by a partition; said partition having an air port for introducing the ambient air into said first atmospheric pressure chamber; and a valve member adapted to close said air port while said altitude is lower than a predetermined level and open said air port to permit an inflow of said ambient air into said first atmospheric pressure chamber at said predetermined level of said altitude.
Claim 4
Dependent Claim
128 words
The exhaust gas recirculation system as set forth in claim 2, wherein said first valve further comprises: a bellows provided in said second atmospheric pressure chamber and adapted to begin expansion at said predetermined level of said altitude; a valve rod secured at one end to one end of said bellows and extending through said partition slidably but airtightly; and an arm mounted on the other end of said valve rod, said valve member being secured to said arm and closing said air port while said altitude is below said predetermined altitude, said valve member being adapted for gradual movement out of said air port with said expansion of said bellows to gradually increase said inflow upon said increase of said altitude to and above said predetermined level.
Claim 5
Dependent Claim
113 words
The exhaust gas recirculation system as set forth in claim 1, wherein said second valve comprises: a housing; a diaphragm provided in said housing; said negative pressure chamber; an exhaust gas chamber separated from said negative pressure chamber by said diaphragm, and having two ports communicating with said exhaust side and said intake manifold, respectively; a valve member fitted to said diaphragm and provided in said exhaust gas chamber; a compression spring provided in said negative pressure chamber to urge said diaphragm downwardly; and a valve seat interposed between said two ports of said exhaust gas chamber defining a valve port adapted to be opened and closed with movement of said valve member.
Claim 6
Dependent Claim
39 words
The exhaust gas recirculation system as set forth in claim 4, wherein said valve member is conial and said valve seat is circular, whereby a clearance through said valve port gradually changes with said movement of said valve member.
Claim 7
Dependent Claim
193 words
The exhaust gas recirculation system as set forth in claim 1, wherein said third valve comprises: a housing; a diaphragm in said housing; said negative pressure chamber; an atmospheric pressure chamber separated from said negative pressure chamber by said diaphragm; a first partition in said housing; a by-pass chamber separated from said atmospheric pressure chamber by said first partition and having an air by-pass port; a second partition in said housing and having a valve port in the center; a positive pressure chamber separated from said by-pass chamber by said second partition; a valve rod secured to said diaphragm at one end and extending through said first partition slidably but airtightly, said valve rod having an opposite end extending through said valve port and having a smaller diameter than said valve port; a valve member secured to said opposite end of said valve rod and adapted to open and close said valve port; and a compression spring provided in said negative pressure chamber to urge said diaphragm downwardly; said positive pressure chamber having a pair of ports communicating with a source of pressurized air supply and said exhaust side of the engine, respectively.
Claim 8
Dependent Claim
63 words
The exhaust gas recirculation system as set forth in claim 1, wherein a venturi throat is provided in a passage connecting said negative pressure chamber of said second valve and said first pressure sensing port and said atmospheric pressure chamber of said first valve is communicated with a passage extending between said venturi throat and said negative pressure chamber of said second valve.
Claim 9
Dependent Claim
63 words
The exhaust gas recirculation system as set forth in claim 1, wherein a venturi throat is provided in a passage connecting said negative pressure chamber of said third valve and said second pressure sensing port and said atmospheric pressure chamber of said first valve is communicated with a passage extending between said venturi throat and said negative pressure chamber of said third valve.
References Cited (Backward Citations)
US3791144A
Cited
US3915136A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-26 | 1981-03-28 | 1981-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-26 | 1985-03-28 | 1985-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-26 | 1989-03-28 | 1989-09-27 | $7700.00 | Window Closed / Lapsed |