US4574627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-fuel ratio detector and method of measuring air-fuel ratio
Assignee: Toyota Motor Corp
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Filing: 1984-02-03
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Granted: 1986-03-11
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Expires: 2004-02-03
Abstract
Abstract An air-fuel ratio detector and an air-fuel ratio measuring method for detecting an oxygen density in an exhaust gas emitted from the internal combustion engine of an automobile. The air-fuel ratio detector has a tubular body and a pair of partition members dividing the tubular body into a closed-end section and an open-end section. At least one of the partition members comprises a solid electrolyte permeable to oxygen ions. A pair of electrodes is mounted on opposite surfaces of the solid electrolyte and connected to a DC power supply, thus constituting an oxygen pump. Another pair of electrodes is mounted on one of the partition members and connected to a DC power supply, thus constituting a limited-current oxygen sensor. Oxygen is introduced into a space between the partition members at all times by the oxygen pump to maintain the gas, which has been supplied through a gas dispersion member into the space, lean.
Inventors
- 👤 Shigenori Sakurai
- 👤 Takashi Kamo
- 👤 Tadayoshi Ikai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:33
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/417
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
183 words
An air-fuel ratio detector for detecting oxygen density in exhaust gas emitted from an engine, comprising: a DC constant-current supply and constant voltage supply; a tubular body; first and second partition members hermetically contacting an inner peripheral surface of said tubular body transversely of an axis of said tubular body, wherein at least said first partition member further comprises a solid electrolyte permeable to oxygen ions; gas dispersion means communicating a space between said partition members with said exhaust gases for introducing gas to be detected and dispersing said gas into a space defined between said first and second partition members; a first pair of electrodes separately mounted on opposite sides of said first partition member and connected to said DC constant-current supply for introducing oxygen ions by permeating into said space through said solid electrolyte; a second pair of electrodes separately mounted on opposite sides of one of said first and second partition members and connected to said DC constant-voltage supply, and means for measuring an air-fuel ratio in said gas based on a current generated between said second pair of electrodes.
Claim 2
Dependent Claim
183 words
An air-fuel ratio detector for detecting oxygen density in exhaust gas emitted from an engine, comprising: a DC constant-current supply and constant voltage supply; a tubular body; first and second partition members hermetically contacting an inner peripheral surface of said tubular body transversely of an axis of said tubular body, wherein at least said first partition member further comprises a solid electrolyte permeable to oxygen ions; gas dispersion means communicating a space between said partition members with said exhaust gases for introducing gas to be detected and dispersing said gas into a space defined between said first and second partition members; a first pair of electrodes separately mounted on opposite sides of said first partition member and connected to said DC constant-current supply for introducing oxygen ions by permeating into said space through said solid electrolyte; a second pair of electrodes separately mounted on opposite sides of one of said first and second partition members and connected to said DC constant-voltage supply, and means for measuring an air-fuel ratio in said gas based on a current generated between said second pair of electrodes.
Claim 3
Dependent Claim
103 words
An air-fuel ratio detector according to claim 1, wherein said second partition member further comprises an end portion of said tubular body, said gas dispersion means being located in said end portion and said second partition member being disposed in said tubular body to divide said tubular body into a closed-end section and an open-end section defining said space and wherein one of said first and second pair of electrodes and said DC constant-current supply connected thereto in combination further comprises an oxygen pump, and the other pair and the DC constant-voltage supply connected thereto in combination further comprises a limited-current oxygen sensor.
Claim 4
Dependent Claim
25 words
An air-fuel ratio detector according to claim 1, wherein said gas dispersion means further comprises a gas dispersion layer located in said second partition member.
Claim 5
Dependent Claim
163 words
An air-fuel ratio detector for detecting oxygen density in exhaust gas emitted from an engine, comprising: a DC constant-current supply and constant voltage power supply; a tubular body; first and second partition members forming a space therebetween and hermetically contacting an inner peripheral surface of said tubular body, wherein said first and second partition members each further comprises a solid electrolyte and divide the tubular body into a closed end section defining said space and an open-end section; a first pair of electrodes mounted on opposite sides of said solid electrolyte of said first partition member and connected to said DC constant-voltage supply for introducing oxygen ions by permeating into the aforementioned space through said solid electrolyte; a second pair of electrodes mounted on opposite sides of said solid electrolyte of said second partition member and connected to said DC constant-current supply; and means for measuring an air-fuel ratio in said gas based on a current generated between said second pair of electrodes.
Claim 6
Dependent Claim
163 words
An air-fuel ratio detector for detecting oxygen density in exhaust gas emitted from an engine, comprising: a DC constant-current supply and constant voltage power supply; a tubular body; first and second partition members forming a space therebetween and hermetically contacting an inner peripheral surface of said tubular body, wherein said first and second partition members each further comprises a solid electrolyte and divide the tubular body into a closed end section defining said space and an open-end section; a first pair of electrodes mounted on opposite sides of said solid electrolyte of said first partition member and connected to said DC constant-voltage supply for introducing oxygen ions by permeating into the aforementioned space through said solid electrolyte; a second pair of electrodes mounted on opposite sides of said solid electrolyte of said second partition member and connected to said DC constant-current supply; and means for measuring an air-fuel ratio in said gas based on a current generated between said second pair of electrodes.
Claim 7
Dependent Claim
23 words
An air-fuel ratio detector according to claim 4, including gas dispersion means comprising a gas dispersion hole defined in said second partition member.
Claim 8
Dependent Claim
174 words
An air-fuel ratio detector for detecting oxygen density in exhaust gas emitted from an engine, comprising: a DC constant-current supply and constant voltage supply; a tubular body; first and second partition members hermetically contacting an inner peripheral surface of said tubular body transversely of an axis of said tubular body wherein said first and second partition members each further comprises a solid electrolyte permeable to oxygen ions; gas dispersion means formed in said tubular portion for introducing the gas to be detected and dispersing said gas into a space defined between said first and second partition members; a first pair of electrodes mounted on said first partition means and connected to said DC constant-current supply for introducing oxygen ions by permeating into said space through said solid electrolyte of said first partition; a second pair of electrodes mounted on opposite sides of said second partition member and connected to said DC constant-voltage supply; and means for measuring an air-fuel ratio in said gas based on a current generated between said second pair of electrodes.
Claim 9
Dependent Claim
174 words
An air-fuel ratio detector for detecting oxygen density in exhaust gas emitted from an engine, comprising: a DC constant-current supply and constant voltage supply; a tubular body; first and second partition members hermetically contacting an inner peripheral surface of said tubular body transversely of an axis of said tubular body wherein said first and second partition members each further comprises a solid electrolyte permeable to oxygen ions; gas dispersion means formed in said tubular portion for introducing the gas to be detected and dispersing said gas into a space defined between said first and second partition members; a first pair of electrodes mounted on said first partition means and connected to said DC constant-current supply for introducing oxygen ions by permeating into said space through said solid electrolyte of said first partition; a second pair of electrodes mounted on opposite sides of said second partition member and connected to said DC constant-voltage supply; and means for measuring an air-fuel ratio in said gas based on a current generated between said second pair of electrodes.
Claim 10
Independent Claim
110 words
A method of measuring an air-fuel ratio for detecting oxygen density in an exhaust gas emitted from an engine, which comprises: introducing oxygen into a closed space into which said exhaust gas to be inspected flows by passing a DC current between a pair of electrodes separately mounted on opposite sides of a solid electrolyte permeable to oxygen ions and which constitutes a portion of a partition defining said space; applying a DC voltage between a second pair of electrodes separately mounted on opposite sides of another portion of said partition; and measuring an air-fuel ratio in said second gas based on a current generated between said pair of electrodes.
Claim 11
Independent Claim
110 words
A method of measuring an air-fuel ratio for detecting oxygen density in an exhaust gas emitted from an engine, which comprises: introducing oxygen into a closed space into which said exhaust gas to be inspected flows by passing a DC current between a pair of electrodes separately mounted on opposite sides of a solid electrolyte permeable to oxygen ions and which constitutes a portion of a partition defining said space; applying a DC voltage between a second pair of electrodes separately mounted on opposite sides of another portion of said partition; and measuring an air-fuel ratio in said second gas based on a current generated between said pair of electrodes.
Claim 12
Independent Claim
110 words
A method of measuring an air-fuel ratio for detecting oxygen density in an exhaust gas emitted from an engine, which comprises: introducing oxygen into a closed space into which a gas to be inspected flows by passing a DC current between a first pair of electrodes separately mounted on opposite sides of a first solid electrolyte permeable to oxygen ions and which constitutes a portion of a partition defining said space; applying a DC voltage between a second pair of electrodes separately mounted on opposite sides of a second solid electrolyte; and measuring an air-fuel ratio in said gas based on a current generated between said second pair of electrodes.
Claim 13
Independent Claim
110 words
A method of measuring an air-fuel ratio for detecting oxygen density in an exhaust gas emitted from an engine, which comprises: introducing oxygen into a closed space into which a gas to be inspected flows by passing a DC current between a first pair of electrodes separately mounted on opposite sides of a first solid electrolyte permeable to oxygen ions and which constitutes a portion of a partition defining said space; applying a DC voltage between a second pair of electrodes separately mounted on opposite sides of a second solid electrolyte; and measuring an air-fuel ratio in said gas based on a current generated between said second pair of electrodes.
References Cited (Backward Citations)
US4264425A
Cited
US4498968A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-10 | 1989-09-09 | 1990-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-10 | 1993-09-09 | 1994-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-10 | 1997-09-09 | 1998-03-11 | $7700.00 | Window Closed / Lapsed |