US4572149A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air/fuel ratio control system for an internal combustion engine
Assignee: Honda Motor Co Ltd
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Filing: 1984-04-18
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Granted: 1986-02-25
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Expires: 2004-04-18
Abstract
Abstract An air/fuel ratio control system for an internal combustion engine equipped with a three-way catalytic converter, comprises first and second fluid supply passages for supplying, for example, a secondary air or a supplemental fuel to the engine, and a flow control valve disposed in the first fluid supply passage for varying the amount of the secondary air or the supplemental fuel in accordance with a detected condition of the air/fuel ratio. An open/close valve is disposed in the second fluid supply passage for opening and closing the communication through the second fluid supply passage without regard to the air/fuel ratio signal and with a predetermined period which is shorter than a normal period of turning over of the air/fuel signal, thereby reducing the deviation of the actual air/fuel ratio from a central value of the air/fuel ratio control, to improve the efficiency of purification of emission by means of the three-way catalytic converter.
Inventors
- 👤 Shumpei Hasegawa
- 👤 Michitaka Shiraiwa
- 👤 Sadatomo Tsuchiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:28
CPC Classifications
F; F02; F02M; F02M23/00; F02M23/04; F02M23/08; F02M7/00; F02M7/12; F02M7/133; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
197 words
An air/fuel ratio control system for an internal combustion engine provided with a three-way catalytic converter in the exhaust system, comprising: an air/fuel ratio signal generating means responsive to rich and lean conditions of the air/fuel ratio in a composition of an exhaust gas of the engine for producing an air/fuel ratio signal representing said air/fuel ratio; a first fluid supply passage connected to the engine for supplying one of a secondary air and a supplemental fuel to the engine; a second fluid supply passage connected to the engine for supplying said one of the secondary air and the supplemental fuel to the engine; a control valve disposed in the first fluid supply passage for controlling the amount of the fluid flowing through the first fluid supply passage; a control means for controlling an opening degree of said control valve to cause a sectional area of the first fluid supply passage to be gradually increased or decreased in accordance with said air/fuel ratio signal; and an open/close valve disposed in said second fluid supply passage, for intermittently opening and closing said second fluid supply passage at predetermined time intervals and without regard to said air/fuel ratio signal.
Claim 2
Dependent Claim
197 words
An air/fuel ratio control system for an internal combustion engine provided with a three-way catalytic converter in the exhaust system, comprising: an air/fuel ratio signal generating means responsive to rich and lean conditions of the air/fuel ratio in a composition of an exhaust gas of the engine for producing an air/fuel ratio signal representing said air/fuel ratio; a first fluid supply passage connected to the engine for supplying one of a secondary air and a supplemental fuel to the engine; a second fluid supply passage connected to the engine for supplying said one of the secondary air and the supplemental fuel to the engine; a control valve disposed in the first fluid supply passage for controlling the amount of the fluid flowing through the first fluid supply passage; a control means for controlling an opening degree of said control valve to cause a sectional area of the first fluid supply passage to be gradually increased or decreased in accordance with said air/fuel ratio signal; and an open/close valve disposed in said second fluid supply passage, for intermittently opening and closing said second fluid supply passage at predetermined time intervals and without regard to said air/fuel ratio signal.
Claim 3
Dependent Claim
57 words
An air/fuel ratio control system as set forth in claim 1, wherein said control valve takes the form of a pressure controlled valve having a pressure chamber and constructed to vary the sectional area of the first fluid passage in accordance with a pressure level of a fluid supplied to the pressure chamber from said control means.
Claim 4
Dependent Claim
75 words
An air/fuel ratio control system as set forth in claim 2, wherein said control means comprises a first control pressure generating means for generating a first control pressure to open said control valve, a second control pressure generating means for generating a second control pressure to close said control valve, and communication means for directing either one of said first and second control pressure to said pressure chamber in accordance with said air/fuel ratio signal.
Claim 5
Dependent Claim
71 words
An air/fuel ratio control system as set forth in claim 3, further comprising a second control valve disposed in said second fluid supply passage and having a pressure chamber, said second control valve being operative to vary a sectional area of said second fluid supply passage in accordance with a pressure level in the pressure chamber, said first control pressure being supplied to said pressure chamber of the second control valve.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-24 | 1989-08-26 | 1990-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-24 | 1993-08-26 | 1994-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-24 | 1997-08-26 | 1998-02-25 | $7700.00 | Window Closed / Lapsed |