US4611562A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for internal combustion engine oxygen sensor heating control which provide sensor heating limited for reliable operation
Assignee: Toyota Motor Corp
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Filing: 1984-10-30
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Granted: 1986-09-16
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Expires: 2004-10-30
Abstract
Abstract An internal combustion engine has an exhaust system and an oxygen sensor fitted to the exhaust system including a sensor element and an electrically powered heater for heating the sensor element. A method is disclosed for controlling the power supplied to said heater by restricting it to be less than a predetermined value. This restriction may be done by controlling the value of a relatively steady current flowing through said heater, or alternatively may be done by supplying an intermittent voltage to said heater and by controlling the duty factor of said intermittent voltage. The power supplied to said heater may be determined by detecting the current flowing through said heater, or may be determined by detecting the voltage across said heater and the current flowing through said heater. Thereby, during engine heating up operation, the temperature of the heater element is raised as quickly as practicable, without any risk of over quick heating of the heater occurring, which might lead to damage thereto. Accordingly it is ensured that engine performance and the quality of exhaust gas emissions at the time of such engine warming up operation are good. A system is also described for implementing this method.
Inventors
- 👤 Jiro Nakano
- 👤 Takao Ishibashi
- 👤 Takao Akatsuka
- 👤 Masao Kawaguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:52
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1493; F02D41/1494; G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/406; G01N27/4065; G01N27/4067
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
109 words
For an internal combustion engine comprising an exhaust system and an oxygen sensor fitted to said exhaust system, said sensor comprising a sensor element, an electrically powered resistive heater for heating said sensor element, and a source of electrical power to said heater: a method for controlling a value of electrical power supplied from the source to said heater, said method comprising the steps of: controlling the electrical power supplied to said heater according to engine operational parameters; and restricting the controlled electrical power supplied to said heater less than a predetermined maximum tolerable value when and only when said heater is not warmed to a predetermined active temperature.
Claim 2
Dependent Claim
109 words
For an internal combustion engine comprising an exhaust system and an oxygen sensor fitted to said exhaust system, said sensor comprising a sensor element, an electrically powered resistive heater for heating said sensor element, and a source of electrical power to said heater: a method for controlling a value of electrical power supplied from the source to said heater, said method comprising the steps of: controlling the electrical power supplied to said heater according to engine operational parameters; and restricting the controlled electrical power supplied to said heater less than a predetermined maximum tolerable value when and only when said heater is not warmed to a predetermined active temperature.
Claim 3
Dependent Claim
30 words
A method according to claim 1, wherein said step of controlling the electrical power supplied to said heater comprises controlling the value of a current flowing continuously through said heater.
Claim 4
Dependent Claim
42 words
A method according to claim 1, wherein said step of controlling the electrical power supplied to said heater comprises supplying an intermittent voltage to said heater, said intermittent voltage having a duty factor; and controlling the duty factor of said intermittent voltage.
Claim 5
Dependent Claim
37 words
A method according to claim 1, wherein said step of controlling the electrical power supplied to said heater comprises detecting a current flowing through said heater to determine a value of power being supplied to said heater.
Claim 6
Dependent Claim
43 words
A method according to claim 1, wherein said step of controlling the electrical power supplied to said heater comprises detecting a voltage across said heater and a current flowing through said heater to determine a value of power being supplied to said heater.
Claim 7
Dependent Claim
30 words
A method according to claim 5, wherein said step of controlling the electrical power supplied to said heater comprises controlling a value of a current flowing continuously through said heater.
Claim 8
Dependent Claim
42 words
A method according to claim 5, wherein said step of controlling the electrical power supplied to said heater comprises supplying an intermittent voltage to said heater, said intermittent voltage having a duty factor; and controlling the duty factor of said intermittent voltage.
Claim 9
Dependent Claim
149 words
For an internal combustion engine comprising an exhaust system; an oxygen sensor fitted to said exhaust system, said oxygen sensor comprising a sensor element and an electrically powered heater for heating said sensor element; a source of electrical power connected to said heater; and a control system for controlling a value of electrical power supplied from said source to said heater, said control system comprising: means for detecting a value of electrical power supplied to said heater; means for determining a target value for the electrical power to be supplied to said heater according to engine operating parameters and for ensuring that the target value is less than a predetermined maximum tolerable value when and only when said heater is not warmed up to a predetermined operating temperature; and means for controlling a value of electrical power supplied to said heater to be substantially equal to said target value.
Claim 10
Dependent Claim
149 words
For an internal combustion engine comprising an exhaust system; an oxygen sensor fitted to said exhaust system, said oxygen sensor comprising a sensor element and an electrically powered heater for heating said sensor element; a source of electrical power connected to said heater; and a control system for controlling a value of electrical power supplied from said source to said heater, said control system comprising: means for detecting a value of electrical power supplied to said heater; means for determining a target value for the electrical power to be supplied to said heater according to engine operating parameters and for ensuring that the target value is less than a predetermined maximum tolerable value when and only when said heater is not warmed up to a predetermined operating temperature; and means for controlling a value of electrical power supplied to said heater to be substantially equal to said target value.
Claim 11
Dependent Claim
42 words
A system according to claim 8, wherein said means for controlling a value of electrical power supplied to said heater to be substantially equal to said target value comprises means for controlling a value of a current flowing continuously through said heater.
Claim 12
Dependent Claim
55 words
A system according to claim 8, wherein said means for controlling a value of electrical power supplied to said heater to be substantially equal to said target value comprises means for supplying an intermittent voltage to said heater, said intermittent voltage having a duty factor, and for controlling the duty factor of said intermittent voltage.
Claim 13
Dependent Claim
32 words
A system according to claim 8, wherein said means for detecting a value of electrical power supplied to said heater comprises means for detecting a value of current flowing through said heater.
Claim 14
Dependent Claim
42 words
A system according to claim 8, wherein said means for detecting a value of electrical power supplied to said heater comprises means for detecting a value of voltage across said heater and for detecting a value of current flowing through said heater.
Claim 15
Dependent Claim
42 words
A system according to claim 12, wherein said means for controlling a value of electrical power supplied to said heater to be substantially equal to said target value comprises means for controlling a value of a current flowing continuously through said heater.
Claim 16
Dependent Claim
55 words
A system according to claim 12, wherein said means for controlling a value of electrical power supplied to said heater to be substantially equal to said target value comprises means for supplying an intermittent voltage to said heater, said intermittent voltage having a duty factor, and for controlling the duty factor of said intermittent voltage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-09-15 | 1990-03-17 | 1990-09-16 | $2000.00 | Window Closed / Lapsed |
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