US4895123A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling air-fuel ratio of internal combustion engine
Assignee: Mitsubishi Electric Corp
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Filing: 1989-02-15
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Granted: 1990-01-23
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Expires: 2009-02-15
Abstract
Abstract Techniques are provided for controlling the operation of an air-fuel ratio control apparatus for an internal combustion engine including feedback control of the air-fuel ratio control. The pump-driving voltage for flowing the pump-driving current used for changing the oxygen concentration is monitored and feedback control is suspended when the pump-driving voltage departs from a predetermined range.
Inventors
- 👤 Masanobu Uchinami
- 👤 Toshihisa Takahashi
- 👤 Hiroyoshi Suzuki
- 👤 Ryoji Nishiyama
- 👤 Shinichi Nishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:18
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1473; F02D41/1475; F02D41/1476; F01; F01N; F01N2550/00; F01N2550/14
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
191 words
An air-fuel ratio control apparatus for an internal combustion engine, said apparatus including a wide range air-fuel ratio sensor, which includes an oxygen sensor section for generating a voltage according to the difference between the atmospheric pressure and the oxygen concentration of the engine exhaust gas and an oxygen pump section for flowing a pump-driving current so as to attain said voltage at a predetermined value, an air-fuel ratio detecting device for providing an air-fuel ratio detecting signal in response to said pump-driving current, and a control section for feedback controlling a mixed gas generation means in accordance with said air-fuel ratio detecting signal to obtain an air-fuel ratio having a required value, said apparatus further comprising a failure detecting means for detecting any failure of the wide range air-fuel ratio sensor by determining when the pump-driving voltage for flowing the pump-driving current remains outside a predetermined range for a predetermined period of time during the operation of the wide range air-fuel ratio sensor, and a feedback breaking means for stopping the feedback control of the air-fuel ratio when such a failure is detected by the wide range air-fuel ratio sensor.
Claim 2
Dependent Claim
191 words
An air-fuel ratio control apparatus for an internal combustion engine, said apparatus including a wide range air-fuel ratio sensor, which includes an oxygen sensor section for generating a voltage according to the difference between the atmospheric pressure and the oxygen concentration of the engine exhaust gas and an oxygen pump section for flowing a pump-driving current so as to attain said voltage at a predetermined value, an air-fuel ratio detecting device for providing an air-fuel ratio detecting signal in response to said pump-driving current, and a control section for feedback controlling a mixed gas generation means in accordance with said air-fuel ratio detecting signal to obtain an air-fuel ratio having a required value, said apparatus further comprising a failure detecting means for detecting any failure of the wide range air-fuel ratio sensor by determining when the pump-driving voltage for flowing the pump-driving current remains outside a predetermined range for a predetermined period of time during the operation of the wide range air-fuel ratio sensor, and a feedback breaking means for stopping the feedback control of the air-fuel ratio when such a failure is detected by the wide range air-fuel ratio sensor.
Claim 3
Independent Claim
169 words
A method of controlling the operation of an air-fuel ratio control apparatus for an internal combustion engine, said apparatus comprising a wide range air-fuel ratio sensor which includes an oxygen sensor section for generating a voltage according to the difference between atmospheric pressure and the oxygen concentration of the engine exhaust gas and an oxygen pump section for flowing a pump-driving current so as to attain said voltage at a predetermined value, an air-fuel ratio detecting device for providing an air-fuel ratio detecting signal in response to said pump-driving current, and a control section for feedback-controlling a mixed gas generating means in accordance with said air-fuel ratio detecting signal to obtain an air-fuel ratio having a required value, said method comprising the steps of: monitoring the pump-driving voltage for flowing the pump-driving current; detecting any failure that occurs by determining when the pump-driving voltage remains out of a predetermined range for a predetermined time period; and suspending the feedback control of the air-fuel ratio when the failure is detected.
Claim 4
Independent Claim
169 words
A method of controlling the operation of an air-fuel ratio control apparatus for an internal combustion engine, said apparatus comprising a wide range air-fuel ratio sensor which includes an oxygen sensor section for generating a voltage according to the difference between atmospheric pressure and the oxygen concentration of the engine exhaust gas and an oxygen pump section for flowing a pump-driving current so as to attain said voltage at a predetermined value, an air-fuel ratio detecting device for providing an air-fuel ratio detecting signal in response to said pump-driving current, and a control section for feedback-controlling a mixed gas generating means in accordance with said air-fuel ratio detecting signal to obtain an air-fuel ratio having a required value, said method comprising the steps of: monitoring the pump-driving voltage for flowing the pump-driving current; detecting any failure that occurs by determining when the pump-driving voltage remains out of a predetermined range for a predetermined time period; and suspending the feedback control of the air-fuel ratio when the failure is detected.
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) | 1993-01-22 | 1993-07-24 | 1994-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-22 | 1997-07-24 | 1998-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-22 | 2001-07-24 | 2002-01-23 | $7700.00 | Window Closed / Lapsed |