US4400944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-fuel ratio control method and apparatus for internal combustion engines
Assignee: Toyota Motor Corp
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Filing: 1980-12-02
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Granted: 1983-08-30
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Expires: 2000-12-02
Abstract
Abstract The temperature and air-fuel ratio of the exhaust gases of an internal combustion engine are sensed to generate signals indicative thereof and the amount of fuel to be injected into the engine is determined in accordance with the signals, thus controlling the air-fuel ratio at a predetermined value and thereby decreasing the abnormal temperature rise in the exhaust system.
Inventors
- 👤 Kenzi Iwamoto
- 👤 Makoto Kuroyanagi
- 👤 Hisasi Kawai
- 👤 Kunimasa Yoshimura
- 👤 Hidetaka Nohira
- 👤 Mitsuyuki Ugajin
- 👤 Hisashi Ohki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:28
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1444; F02D41/1446; F02D41/0002; F02D41/0007; F02B; F02B1/00; F02B1/02; F02B1/04; F02D2200/00; F02D2200/02; F02D2200/06; F02D2200/0606; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
195 words
A method of controlling the air-fuel ratio of an internal combustion engine comprising the steps of: sensing the amount of air sucked into the engine to generate an intake signal; sensing the temperature of the exhaust gases of said engine to generate a temperature signal; sensing the air-fuel ratio by monitoring the composition of said exhaust gases to generate a ratio signal; discriminating whether the temperature of the exhaust gases is lower than a predetermined value on the basis of said temperature signal; first determining with a microcomputer, in response to said intake signal and said ratio signal, the amount of fuel to be injected to cause the air-fuel ratio to approach a stoichiometric air-fuel ratio on the basis of said ratio signal when the temperature of exhaust gases is lower than said predetermined value; second predetermining with a microcomputer, in response to said intake signal and said ratio signal the injection fuel amount to cause the air-fuel ratio to become rich on the basis of said air-fuel ratio signal when the exhaust gas temperature is higher than the predetermined value; and injecting the fuel into said engine on the basis of said determining steps.
Claim 2
Independent Claim
195 words
A method of controlling the air-fuel ratio of an internal combustion engine comprising the steps of: sensing the amount of air sucked into the engine to generate an intake signal; sensing the temperature of the exhaust gases of said engine to generate a temperature signal; sensing the air-fuel ratio by monitoring the composition of said exhaust gases to generate a ratio signal; discriminating whether the temperature of the exhaust gases is lower than a predetermined value on the basis of said temperature signal; first determining with a microcomputer, in response to said intake signal and said ratio signal, the amount of fuel to be injected to cause the air-fuel ratio to approach a stoichiometric air-fuel ratio on the basis of said ratio signal when the temperature of exhaust gases is lower than said predetermined value; second predetermining with a microcomputer, in response to said intake signal and said ratio signal the injection fuel amount to cause the air-fuel ratio to become rich on the basis of said air-fuel ratio signal when the exhaust gas temperature is higher than the predetermined value; and injecting the fuel into said engine on the basis of said determining steps.
Claim 3
Dependent Claim
67 words
A method according to claim 1, further comprising the step of supercharging the amount of air supplied to said engine by a compressor coupled by a common shaft to a turbine disposed to be driven by the exhaust gases flowing through an exhaust pipe of said engine, and wherein said temperature sensing step senses the temperature of the exhaust gases flowing into a casing of said turbine.
Claim 4
Dependent Claim
186 words
An air-fuel ratio control apparatus for an internal combustion engine comprising: means for sensing the amount of air sucked into the engine; temperature sensor means for sensing the temperature of the exhaust gases of said engine to generate a temperature signal; air-fuel ratio sensor means for sensing the air-fuel ratio by monitoring the composition of said exhaust gases to generate a ratio signal; microcomputer means, responsive to said temperature signal and said ratio signal for (1) determining response to said temperature signal whether the temperature of the exhaust gases is lower than a predetermined value; (2) determining in response to said intake signal and said ratio signal; the amount of fuel to be injected to cause the air-fuel ratio to approach a stoichiometric air-fuel ratio when the temperature of exhaust gases is lower than the predetermined value; and (3) determining in response to said intake signal and said ratio signal the injection fuel amount to cause the air-fuel ratio to become rich when the exhaust gas temperature is higher than the predetermined value; and injector means, responsive to said microcomputer for injecting fuel into the engine.
Claim 5
Dependent Claim
186 words
An air-fuel ratio control apparatus for an internal combustion engine comprising: means for sensing the amount of air sucked into the engine; temperature sensor means for sensing the temperature of the exhaust gases of said engine to generate a temperature signal; air-fuel ratio sensor means for sensing the air-fuel ratio by monitoring the composition of said exhaust gases to generate a ratio signal; microcomputer means, responsive to said temperature signal and said ratio signal for (1) determining response to said temperature signal whether the temperature of the exhaust gases is lower than a predetermined value; (2) determining in response to said intake signal and said ratio signal; the amount of fuel to be injected to cause the air-fuel ratio to approach a stoichiometric air-fuel ratio when the temperature of exhaust gases is lower than the predetermined value; and (3) determining in response to said intake signal and said ratio signal the injection fuel amount to cause the air-fuel ratio to become rich when the exhaust gas temperature is higher than the predetermined value; and injector means, responsive to said microcomputer for injecting fuel into the engine.
Claim 6
Dependent Claim
79 words
An apparatus according to claim 3, further comprising supercharger means including a turbine disposed to be driven by the exhaust gases flowing into an exhaust pipe of said engine and a compressor coupled to said turbine by a common shaft and operable to supercharge the amount of air supplied to said engine, and wherein said exhaust gas temperature sensor means is disposed to sense the temperature of the exhaust gases flowing into a turbine casing of said supercharger means.
Claim 7
Dependent Claim
45 words
A method according to claim 1 wherein said second determining step further includes the steps of: determining the difference between said exhaust gas temperature and said predetermined value; determining a correction amount from said difference; and correcting the injection fuel amount by said correction amount.
Claim 8
Dependent Claim
38 words
A method according to claim 5 wherein said correction amount determining step includes the steps of: determining whether the exhaust gas temperature is increasing or decreasing; and increasing said correction amount when the exhaust gas temperature is increasing.
Claim 9
Dependent Claim
31 words
A method according to claim 6 wherein said correction amount determining step further includes the step of maintaining said correction amount as it is when said exhaust gas temperature is decreasing.
Claim 10
Dependent Claim
45 words
A method according to claim 1 wherein said first determining step further includes the steps of: determining the difference between said exhaust gas temperature and said predetermined value; determining a correction amount from said difference; and correcting the injection fuel amount by said correction amount.
Claim 11
Dependent Claim
39 words
A method according to claim 8 wherein said correction amount determining step further includes the steps of: determining whether the exhaust gas temperature is increasing or decreasing; and decreasing the correction amount when the exhaust gas temperature is decreasing.
Claim 12
Dependent Claim
31 words
A method according to claim 8 wherein said correction amount determining step further includes the step of maintaining said correction amount as it is when said exhaust gas temperature is increasing.
Claim 13
Dependent Claim
39 words
An apparatus according to claim 3 wherein said microcomputer means determines the difference between said exhaust gas temperature and said predetermined value, determines a correction amount from said difference, and corrects the injection fuel amount by said correction amount.
Claim 14
Dependent Claim
44 words
An apparatus according to claim 11 wherein said microcomputer means, when the exhaust gas temperature is higher than said predetermined value, determines whether the exhaust gas temperature is increasing or not and reduces said correction amount when the exhaust gas temperature is not increasing.
Claim 15
Dependent Claim
43 words
An apparatus according to claim 11 wherein said microcomputer means, when said exhaust gas temperature is lower than said predetermined value, determines whether the exhaust gas temperature is increasing or not, and increases said correction amount when the exhaust gas temperature is increasing.
Claim 16
Dependent Claim
36 words
An apparatus according to claim 13 wherein said microcomputer means, when said exhaust gas temperature is lower than said predetermined value, maintains the correction amount as it is when said exhaust gas temperature is not increasing.
Claim 17
Dependent Claim
17 words
An apparatus according to claim 4 wherein said air-fuel ratio sensor is provided downstream of said turbine.
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) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |