US5375416A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air-fuel ratio sensor deterioration-detecting device for internal combustion engines
Assignee: Honda Motor Co Ltd
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Filing: 1994-01-21
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Granted: 1994-12-27
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Expires: 2014-01-21
Abstract
Abstract An air-fuel ratio sensor deterioration-detecting device for an internal combustion engine having a catalytic converter arranged in the exhaust system, and first and second air-fuel ratio sensors arranged upstream and downstream of the catalytic converter respectively has an ECU which calculates an air-fuel ratio correction amount, based on outputs from the first air-fuel ratio sensors, and detects deterioration of the first air-fuel ratio sensor, based on the output from the first air-fuel ratio sensor. The ECU inhibits detection of deterioration of the first air-fuel ratio sensor when the air-fuel ratio correction amount falls outside a predetermined range.
Inventors
- 👤 Yoichi Iwata
- 👤 Toshihiko Sato
- 👤 Yasunari Seki
- 👤 Tsuyoshi Takizawa
- 👤 Takayoshi Nakayama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:55
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/14; F02D41/1438; F02D41/1493; F02D41/1495
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
139 words
An air-fuel ratio sensor deterioration-detecting device for an internal combustion engine having an exhaust system, catalytic converter means arranged in said exhaust system, first and second air-fuel ratio sensor means arranged in said exhaust system upstream and downstream of said catalytic converter means, respectively, air-fuel ratio correction amount-calculating means for calculating an air-fuel ratio correction amount, based on outputs from said first and second air-fuel ratio sensor means, and air-fuel ratio control means for controlling an air-fuel ratio of a mixture supplied to the engine, based on the calculated air-fuel ratio correction amount, comprising: deterioration-detecting means for detecting deterioration of said first air-fuel ratio sensor means, based on the output from said first air-fuel ratio sensor means; and deterioration detection-inhibiting means for inhibiting operation of said deterioration-detecting means when said air-fuel ratio correction amount falls outside a predetermined range.
Claim 2
Dependent Claim
139 words
An air-fuel ratio sensor deterioration-detecting device for an internal combustion engine having an exhaust system, catalytic converter means arranged in said exhaust system, first and second air-fuel ratio sensor means arranged in said exhaust system upstream and downstream of said catalytic converter means, respectively, air-fuel ratio correction amount-calculating means for calculating an air-fuel ratio correction amount, based on outputs from said first and second air-fuel ratio sensor means, and air-fuel ratio control means for controlling an air-fuel ratio of a mixture supplied to the engine, based on the calculated air-fuel ratio correction amount, comprising: deterioration-detecting means for detecting deterioration of said first air-fuel ratio sensor means, based on the output from said first air-fuel ratio sensor means; and deterioration detection-inhibiting means for inhibiting operation of said deterioration-detecting means when said air-fuel ratio correction amount falls outside a predetermined range.
Claim 3
Dependent Claim
40 words
An air-fuel ratio sensor deterioration-detecting device as claimed in claim 1, including deterioration detection-permitting means for permitting the operation of said deterioration-detecting means after a predetermined time period elapses after said air-fuel ratio correction amount returns into said predetermined range.
Claim 4
Dependent Claim
69 words
An air-fuel ratio sensor deterioration-detecting device as claimed in claim 1, including limiting means for limiting said air-fuel ratio correction amount within a first predetermined range when said air-fuel ratio correction amount falls outside said first predeatermiend range, and wherein said deterioration detection-inhibiting means inhibits the operation of said deterioration-detecting means when said air-fuel ratio correction amount falls outside a second predetermined range included within said first predetermined range.
Claim 5
Dependent Claim
53 words
An air-fuel ratio sensor deterioration-detecting device as claimed in claim 1, including inversion period-measuring means for measuring an inversion period with which the output from said first air-fuel ratio sensor means is inverted, and wherein said deterioration-detecting means detects deterioration of said first air-fuel ratio sensor means, based on the measured inversion period.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-12-26 | 1998-06-27 | 1998-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-26 | 2002-06-27 | 2002-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-26 | 2006-06-27 | 2006-12-27 | $7700.00 | Window Closed / Lapsed |