US4584979A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-fuel ratio control system for an internal combustion engine with a three way catalytic converter
Assignee: Honda Motor Co Ltd
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Filing: 1984-08-28
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Granted: 1986-04-29
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Expires: 2004-08-28
Abstract
Abstract An air-fuel ratio control system for an internal combustion engine having an oxygen concentration sensor for a feedback control of air-fuel ratio, including an intake air temperature sensing means and a control means for operating/stopping the feedback control of air-fuel ratio in accordance with the detected value of the intake air temperature. When the intake air temperature is below a predetermined level, the feedback control is stopped, and an auxiliary fuel supply means is activated, and at the same time a supply of atmospheric air into a slow speed fuel supply system of the engine is stopped. Thus, the air-fuel ratio is controlled to the rich side when the open loop control is selected, in order to secure a stable engine operation.
Inventors
- 👤 Akira Fujimura
- 👤 Yoshinori Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 01:47
CPC Classifications
F; F02; F02M; F02M7/00; F02M7/12; F02M7/133; F02M23/00; F02M23/04; F02M23/08; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
193 words
An air-fuel ratio control system for an internal combustion engine having at least one of a main fuel passage and a slow fuel passage in a fuel supply system thereof, the air-fuel ratio control system being adapted for performing a feedback control of air-fuel ratio according to a detected oxygen concentration of an exhaust gas of the engine, and comprising: an auxiliary fuel supply means for supplying an auxiliary fuel to the engine through a fuel nozzle opening at a venturi part of a carburetor of the engine; an intake air temperature sensing means for sensing temperature of intake air introduced to the engine; and a control means for operating/stopping the feedback control of air-fuel ratio in accordance with the temperature of intake air sensed by said intake air temperature sensing means, said control means comprising a single control valve being adapted to stop said feedback control of air-fuel ratio and activate said auxiliary fuel supply means and to stop a supply of air into at least one of the main fuel passage and slow fuel passage, for enriching the air-fuel ratio when said temperature of intake air is below a predetermined level.
Claim 2
Dependent Claim
193 words
An air-fuel ratio control system for an internal combustion engine having at least one of a main fuel passage and a slow fuel passage in a fuel supply system thereof, the air-fuel ratio control system being adapted for performing a feedback control of air-fuel ratio according to a detected oxygen concentration of an exhaust gas of the engine, and comprising: an auxiliary fuel supply means for supplying an auxiliary fuel to the engine through a fuel nozzle opening at a venturi part of a carburetor of the engine; an intake air temperature sensing means for sensing temperature of intake air introduced to the engine; and a control means for operating/stopping the feedback control of air-fuel ratio in accordance with the temperature of intake air sensed by said intake air temperature sensing means, said control means comprising a single control valve being adapted to stop said feedback control of air-fuel ratio and activate said auxiliary fuel supply means and to stop a supply of air into at least one of the main fuel passage and slow fuel passage, for enriching the air-fuel ratio when said temperature of intake air is below a predetermined level.
Claim 3
Dependent Claim
251 words
An air-fuel ratio control system for an internal combustion engine having a slow speed system in a fuel supply system thereof, the air-fuel ratio control system being adapted for performing a feedback control of air-fuel ratio according to a detected oxygen concentration of an exhaust gas of the engine, and comprising: an auxiliary fuel supply means for supplying an auxiliary fuel to the engine through a fuel nozzle opening at a venturi part of a carburetor of the engine; an intake air temperature sensing means for sensing temperature of intake air introduced to the engine; and a control means for operating/stopping the feedback control of air-fuel ratio in accordance with the temperature of intake air sensed by said intake air temperature sensing means, said control means being adapted to stop said feedback control of air-fuel ratio and activate said auxiliary fuel supply means and to stop a supply of air into a fuel passage of the slow speed system, for enriching the air-fuel ratio when said temperature of intake air is below a predetermined level, wherein said auxiliary fuel supply means comprises a vacuum responsive control valve for controlling the supply of said auxiliary fuel in accordance with magnitude of vacuum supplied from an intake manifold to a vacuum chamber thereof, and said control means includes a three-way valve for introducing an atmospheric pressure into said pressure chamber and stopping the supply of atmospheric air into said slow speed system when the temperature of intake air is below the predetermined level.
Claim 4
Dependent Claim
251 words
An air-fuel ratio control system for an internal combustion engine having a slow speed system in a fuel supply system thereof, the air-fuel ratio control system being adapted for performing a feedback control of air-fuel ratio according to a detected oxygen concentration of an exhaust gas of the engine, and comprising: an auxiliary fuel supply means for supplying an auxiliary fuel to the engine through a fuel nozzle opening at a venturi part of a carburetor of the engine; an intake air temperature sensing means for sensing temperature of intake air introduced to the engine; and a control means for operating/stopping the feedback control of air-fuel ratio in accordance with the temperature of intake air sensed by said intake air temperature sensing means, said control means being adapted to stop said feedback control of air-fuel ratio and activate said auxiliary fuel supply means and to stop a supply of air into a fuel passage of the slow speed system, for enriching the air-fuel ratio when said temperature of intake air is below a predetermined level, wherein said auxiliary fuel supply means comprises a vacuum responsive control valve for controlling the supply of said auxiliary fuel in accordance with magnitude of vacuum supplied from an intake manifold to a vacuum chamber thereof, and said control means includes a three-way valve for introducing an atmospheric pressure into said pressure chamber and stopping the supply of atmospheric air into said slow speed system when the temperature of intake air is below the predetermined level.
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) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |