Patent US4886035A successfully refreshed from Google Patents.
US4886035A
Expired / Lapsed
US
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Air-fuel ratio control method for an internal combustion engine
Assignee: Honda Motor Co Ltd
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Filing: 1988-03-30
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Granted: 1989-12-12
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Expires: 2008-03-30
Abstract
Abstract An air-fuel ratio control method which controls the amount of the intake side secondary air in accordance with either the engine temperature or both of the engine temperature and the intake air temperature upon the engine re-start under a high engine temperature, thereby avoiding enrichment of the intake air-fuel ratio even at the occurrence of the percolation phenomenon and to improve the engine-start property. Furthermore, the amount of the intake side secondary air is controlled until the start of the air-fuel ratio feedback control to accomplish improvement in the purification of the exhaust gases and in the stability of the engine speed at an idle state.
Inventors
- 👤 Norio Tomobe
- 👤 Haruo Shimamura
- 👤 Kozo Suzuki
- 👤 Yutaka Taniguchi
- 👤 Yuji Fujiki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:54
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/04; F02D41/06; F02D41/062; F02D41/064; F02D31/00; F02D31/001; F02D31/002; F02D31/003; F02D31/005; F02M; F02M23/00; F02M23/04; F02M23/10; F02D11/00; F02D11/06; F02D11/10; F02D2011/101; F02D2011/102; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
130 words
In an air-fuel ratio control method for an internal combustion engine having a secondary intake air supplying passage communicating with an intake pipe downstream of a throttle valve in a carburetor of said internal combustion engine and a linear type flow regulating valve provided in said secondary intake air supplying passage; the improvement comprising the steps of: detecting an engine temperature at starting of said internal combustion engine; initiating to control said flow regulating valve to a controlled opening degree set correspondingly to said engine temperature when the detected engine temperature is greater than a predetermined temperature; and stopping the control of said flow regulating valve to said controlled opening degree when a control time period corresponding to the detected engine temperature is elapsed from the starting of said engine.
Claim 2
Dependent Claim
130 words
In an air-fuel ratio control method for an internal combustion engine having a secondary intake air supplying passage communicating with an intake pipe downstream of a throttle valve in a carburetor of said internal combustion engine and a linear type flow regulating valve provided in said secondary intake air supplying passage; the improvement comprising the steps of: detecting an engine temperature at starting of said internal combustion engine; initiating to control said flow regulating valve to a controlled opening degree set correspondingly to said engine temperature when the detected engine temperature is greater than a predetermined temperature; and stopping the control of said flow regulating valve to said controlled opening degree when a control time period corresponding to the detected engine temperature is elapsed from the starting of said engine.
Claim 3
Dependent Claim
50 words
The air-fuel ratio control method as defined in claim 1, wherein the higher the detected engine temperature is, the greater said controlled opening degree is set and the longer said control time is set in controlling the opening degree of said flow regulating valve corresponding to the detected engine temperature.
Claim 4
Dependent Claim
108 words
In air-fuel ratio control method for an internal combustion engine having a secondary intake air supplying passage communicating with an intake pipe downstream of a throttle valve in a carburetor and a flow regulating valve provided in said secondary intake air supplying passage; the improvement comprising the steps of: detecting an intake air temperature and an engine temperature at starting of said engine; and controlling an opening degree of said flow regulating valve in accordance with both of the detected intake air temperature and the detected engine temperature when the detected intake air temperature is high and the detected engine temperature is high at starting of said engine.
Claim 5
Dependent Claim
108 words
In air-fuel ratio control method for an internal combustion engine having a secondary intake air supplying passage communicating with an intake pipe downstream of a throttle valve in a carburetor and a flow regulating valve provided in said secondary intake air supplying passage; the improvement comprising the steps of: detecting an intake air temperature and an engine temperature at starting of said engine; and controlling an opening degree of said flow regulating valve in accordance with both of the detected intake air temperature and the detected engine temperature when the detected intake air temperature is high and the detected engine temperature is high at starting of said engine.
Claim 6
Dependent Claim
100 words
The air-fuel ratio control method as defined in claim 3, wherein when the detected intake air temperature is high and the detected engine temperature is high at starting of said engine, the opening degree of said flow regulating valve is controlled to an opening degree according to both of the detected intake air temperature and the detected engine temperature, and until a condition that an engine speed greater than a cranking speed continues for a set time period and the opening degree of said flow regulating valve is gradually decreased after said condition has continued for said set time period.
Claim 7
Dependent Claim
28 words
The air-fuel ratio control method as defined in claim 4, wherein said set time is determined in accordance with the detected engine temperature at starting of said engine.
Claim 8
Dependent Claim
162 words
In an air-fuel ratio control method for an internal combustion engine having a secondary intake air supplying passage communicating with an intake pipe downstream of a throttle valve in a carburetor of a suction system, an exhaust gas component concentration sensor provided in an exhaust system for detecting an exhaust gas component concentration in an exhaust gas, a flow regulating valve provided in said secondary intake air supplying passage, and control means for controlling an opening degree of said flow regulating valve according to an output signal from said exhaust gas component concentration sensor under at least one predetermined operational condition; the improvement comprising the steps of: detecting an engine temperature at starting of said engine; and continuing to open said flow regulating valve irrespective of the output signal from said exhaust gas component concentration sensor when said engine is in a hot condition where the detected engine temperature is greater than a predetermined temperature, until said predetermined operational conditions are satisfied.
Claim 9
Dependent Claim
162 words
In an air-fuel ratio control method for an internal combustion engine having a secondary intake air supplying passage communicating with an intake pipe downstream of a throttle valve in a carburetor of a suction system, an exhaust gas component concentration sensor provided in an exhaust system for detecting an exhaust gas component concentration in an exhaust gas, a flow regulating valve provided in said secondary intake air supplying passage, and control means for controlling an opening degree of said flow regulating valve according to an output signal from said exhaust gas component concentration sensor under at least one predetermined operational condition; the improvement comprising the steps of: detecting an engine temperature at starting of said engine; and continuing to open said flow regulating valve irrespective of the output signal from said exhaust gas component concentration sensor when said engine is in a hot condition where the detected engine temperature is greater than a predetermined temperature, until said predetermined operational conditions are satisfied.
Claim 10
Dependent Claim
93 words
The air-fuel ratio control method as defined in claim 6, wherein the opening degree of said flow regulating valve is controlled to a controlled opening degree corresponding to the detected engine temperature at starting of said engine, and until a control time corresponding to the detected engine temperature from the completion of the engine starting operation is elapsed, while after said control time is elapsed from the completion of the engine starting operation, the opening degree of said flow regulating valve is kept at an opening degree irrespective of the detected engine temperature.
Claim 11
Dependent Claim
44 words
The air-fuel ratio control method as defined in claim 7, wherein the opening degree of said flow regulating valve is kept at an opening degree corresponding to an engine load after said control time from the completion of the engine starting operation is elapsed.
Claim 12
Dependent Claim
39 words
The air-fuel ratio control method as defined in claim 7, wherein the opening degree of said flow regulating valve is maintained at a predetermined opening after said control time from the completion of the engine starting operation is elapsed.
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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) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |