US4911130A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-fuel ratio controller of internal combustion engine
Assignee: Mitsubishi Electric Corp
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Filing: 1989-03-10
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Granted: 1990-03-27
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Expires: 2009-03-10
Abstract
Abstract An air-fuel (A/F) controller of an internal combustion engine, which computes an average value of a plurality of duty ratios of the voltage supplied to the heater according to the engine speed and the engine load periodically detected during a period from a predetermined moment up to the present, and fixes said average value as the present duty ratio of the voltage to be supplied to the heater, since the A/F ratio sensor is heated not only by the heater but also by exhaust gas. The A/F ratio controller smoothes the variation of voltage to be supplied to the heater by applying the computed average value as the present duty ratio of the supply voltage which is to be supplied to the heater. Accordingly, even when the driving condition is in high-speed, variation of the temperature borne by the heater is mild and smooth, and thus, the temperature of the oxygen-concentration detecting element does not rise suddenly. Furthermore, the A/F ratio controller corrects the above-mentioned present duty ratio of the voltage to be supplied to the heater according to the supply voltage to be supplied to the heater.
Inventors
- 👤 Toshihisa Takahashi
- 👤 Masanobu Uchinami
- 👤 Ryoji Nishiyama
- 👤 Seiya Kominami
- 👤 Shinichi Nishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:18
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1493; F02D41/1494; F02D41/1486; F02D41/1488; F02D41/1491
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
199 words
An air-fuel (A/F) ratio controller of an internal combustion engine comprising; an A/F ratio sensor which is composed of the following; an oxygen-concentration detecting element for generating electric signals responsive to the oxygen concentration of the exhaust gas of said engine, and a heater which heats said oxygen-concentration detecting element to a predetermined temperature; a controller for executing feedback control of quantity of fuel to be supplied to said engine in accordance with electric signals generated by said oxygen-concentration detecting means so that the A/F ratio of fuel-mixed vapor to be supplied to said engine can be a predetermined A/F ratio; engine-speed detection means for detecting periodically the speed of said engine; engine-load detection means for detecting periodically load applied to said engine; duty-ratio computing means for computing duty ratio of the voltage to be supplied to said heater on the basis of the relation between the detected speed of said engine and load applied thereto; average-value computing means for computing average value of a plurality of duty rations computed during a period from a predetermined moment up to the present; and heater-driving means for driving said heater on the basis of the duty ratio of said average value.
Claim 2
Dependent Claim
199 words
An air-fuel (A/F) ratio controller of an internal combustion engine comprising; an A/F ratio sensor which is composed of the following; an oxygen-concentration detecting element for generating electric signals responsive to the oxygen concentration of the exhaust gas of said engine, and a heater which heats said oxygen-concentration detecting element to a predetermined temperature; a controller for executing feedback control of quantity of fuel to be supplied to said engine in accordance with electric signals generated by said oxygen-concentration detecting means so that the A/F ratio of fuel-mixed vapor to be supplied to said engine can be a predetermined A/F ratio; engine-speed detection means for detecting periodically the speed of said engine; engine-load detection means for detecting periodically load applied to said engine; duty-ratio computing means for computing duty ratio of the voltage to be supplied to said heater on the basis of the relation between the detected speed of said engine and load applied thereto; average-value computing means for computing average value of a plurality of duty rations computed during a period from a predetermined moment up to the present; and heater-driving means for driving said heater on the basis of the duty ratio of said average value.
Claim 3
Dependent Claim
25 words
An A/F ratio controller of an internal combustion engine as set forth in claim 1, wherein said engine-load detection means comprises an air-inlet pressure detector.
Claim 4
Dependent Claim
26 words
An A/F ratio controller of an internal combustion engine as set forth in claim 1, wherein said engine-load detection means comprises a throttle valve aperture-degree detector.
Claim 5
Dependent Claim
37 words
An A/F ratio controller of an internal combustion engine as set forth in claim 1, wherein said engine-load detection means comprises an air-flow sensor for detecting quantity of absorbed air per a certain rotation of said engine.
Claim 6
Dependent Claim
72 words
An A/F ratio controller of an internal combustion engine as set forth in claim 1, wherein said duty-ratio computing means computes a duty ratio corresponding to at least one of rotational speed of said engine and engine load by applying interpolation, on the basis of the degree of the increase or decrease of duty ratios predetermined by the relation between the speed of said engine and the load applied to said engine.
Claim 7
Dependent Claim
211 words
An A/F ratio controller of an internal combustion engine comprising; an A/F ratio sensor which is composed of the following; an oxygen-concentration detecting element for generating electric signals responsive to the oxygen concentration of the exhaust gas of said engine, and a heater for heating said oxygen-concentration detecting element to a predetermined temperature; a controller for executing feedback control of quantity of fuel to be supplied to said engine in accordance with electric signals generated by said oxygen-concentration detecting means so that the A/F ratio of fuel-mixed vapor to be supplied to said engine can be a predetermined A/F ratio; engine-speed detection means for detecting periodically the speed of said engine; engine-load detection mean* for detecting periodically load applied to said engine; duty-ratio computing means for computing duty ratio of the voltage to be supplied to said heater on the basis of the relation between the detected speed of said engine and load applied thereto; average-value computing means for computing average value of a plurality of duty ratios computed during a period from a predetermined moment up to the present; and heater-driving means for driving said heater on the basis of the duty ratio obtained by correcting said average value according to the supply voltage to be supplied to said heater.
Claim 8
Dependent Claim
211 words
An A/F ratio controller of an internal combustion engine comprising; an A/F ratio sensor which is composed of the following; an oxygen-concentration detecting element for generating electric signals responsive to the oxygen concentration of the exhaust gas of said engine, and a heater for heating said oxygen-concentration detecting element to a predetermined temperature; a controller for executing feedback control of quantity of fuel to be supplied to said engine in accordance with electric signals generated by said oxygen-concentration detecting means so that the A/F ratio of fuel-mixed vapor to be supplied to said engine can be a predetermined A/F ratio; engine-speed detection means for detecting periodically the speed of said engine; engine-load detection mean* for detecting periodically load applied to said engine; duty-ratio computing means for computing duty ratio of the voltage to be supplied to said heater on the basis of the relation between the detected speed of said engine and load applied thereto; average-value computing means for computing average value of a plurality of duty ratios computed during a period from a predetermined moment up to the present; and heater-driving means for driving said heater on the basis of the duty ratio obtained by correcting said average value according to the supply voltage to be supplied to said heater.
Claim 9
Dependent Claim
25 words
An A/F ratio controller of an internal combustion engine as set forth in claim 6, wherein said engine-load detection means comprises an air-inlet pressure detector.
Claim 10
Dependent Claim
26 words
An A/F ratio controller of an internal combustion engine as set forth in claim 6, wherein said engine-load detection means comprises a throttle valve aperture-degree detector.
Claim 11
Dependent Claim
37 words
An A/F ratio controller of an internal combustion engine as set forth in claim 6, wherein said engine-load detection means comprises an air-flow sensor for detecting quantity of absorbed air per one speed cycle of said engine.
Claim 12
Dependent Claim
72 words
An A/F ratio controller of an internal combustion engine as set forth in claim 6, wherein said duty-ratio detection means computes a duty ratio corresponding to at least one of rotational speed of said engine and engine load by applying interpolation on the basis of the degree of the increase or decrease of duty ratios predetermined by the relation between the speed of said engine and the load applied to said engine.
References Cited (Backward Citations)
US4538575A
Cited
US4651402A
Cited
JPS6072561A
Cited
US4611562A
Cited
US4694809A
Cited
US4721084A
Cited
US4765298A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-03-26 | 1993-09-25 | 1994-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-26 | 1997-09-25 | 1998-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-26 | 2001-09-25 | 2002-03-27 | $7700.00 | Window Closed / Lapsed |