US5469832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Canister purge control method and apparatus for internal combustion engine
Assignee: Hitachi Ltd
•
Filing: 1994-09-20
•
Granted: 1995-11-28
•
Expires: 2014-09-20
Abstract
Abstract According to one embodiment of the invention, a purge quantity is controlled in proportion to an air quantity sucked into an internal combustion engine. During normal operation of the engine, a purge air-fuel ratio is calculated according to a purge rate and an air-fuel feedback control quantity. During transient operation of the engine, a target air-fuel ratio feedback control quantity is calculated according to the purge rate and the purge air-fuel ratio. When the difference between the air-fuel ratio feedback control quantity and the target air-fuel ratio feedback control quantity is greater than a predetermined value, the air-fuel ratio feedback control quantity is corrected to the target air-fuel ratio feedback control quantity. An undue fluctuation in air-fuel ratio of a fuel mixture supplied to cylinders occurring upon rapid fluctuation in purge rate can be suppressed.
Inventors
- 👤 Mamoru Nemoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:56
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/0025; F02D41/003; F02D41/0045; F02M; F02M25/00; F02M25/08; F02D41/0042
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
152 words
An engine air/fuel mixture control method comprising: temporarily recovering a fuel vapor generated in a fuel tank to fuel vapor recovering means, purging said recovered fuel vapor to said engine during operation of said engine with a purge air quantity (Qevp) being controlled at purge ratio (Kevp) proportional to an air quantity (Qtvo) supplied to said engine, and feedback controlling an air-fuel ratio in the engine intake by a feedback control quantity (α); said method comprising the steps of: determining a purge air-fuel ratio (AFevp), in response to a first purge ratio (Kevp1) and a feedback control quantity (α) of said air-fuel ratio; and determining a target air-fuel ratio feedback control quantity according to said estimated purge air-fuel ratio (AFevp) and a second ratio (Kevp2); and changing said feedback control quantity (α) of said air-fuel ratio according to said calculated target air-fuel ratio feedback control quantity when Kevp1 and Kevp2 are unequal.
Claim 2
Dependent Claim
152 words
An engine air/fuel mixture control method comprising: temporarily recovering a fuel vapor generated in a fuel tank to fuel vapor recovering means, purging said recovered fuel vapor to said engine during operation of said engine with a purge air quantity (Qevp) being controlled at purge ratio (Kevp) proportional to an air quantity (Qtvo) supplied to said engine, and feedback controlling an air-fuel ratio in the engine intake by a feedback control quantity (α); said method comprising the steps of: determining a purge air-fuel ratio (AFevp), in response to a first purge ratio (Kevp1) and a feedback control quantity (α) of said air-fuel ratio; and determining a target air-fuel ratio feedback control quantity according to said estimated purge air-fuel ratio (AFevp) and a second ratio (Kevp2); and changing said feedback control quantity (α) of said air-fuel ratio according to said calculated target air-fuel ratio feedback control quantity when Kevp1 and Kevp2 are unequal.
Claim 3
Dependent Claim
57 words
A canister purge control method for an internal combustion engine according to claim 1, wherein when a difference between said air-fuel ratio feedback control quantity and said target air-fuel ratio feedback control quantity is greater than a predetermined value, said air-fuel ratio feedback control quantity is corrected according to said target air-fuel ratio feedback control quantity calculated.
Claim 4
Dependent Claim
52 words
A canister purge control method for an internal combustion engine according to claim 2, wherein said correcting of said air-fuel ratio feedback control quantity according to said target air-fuel ratio feedback control quantity calculated comprises adjusting of said air-fuel ratio feedback control quantity to said target air-fuel ratio feedback control quantity calculated.
Claim 5
Dependent Claim
42 words
A canister purge control method for an internal combustion engine according to claim 2, wherein when a change quantity of said purge rate is greater than a predetermined value, an operational condition of said engine is determined as said transient operational condition.
Claim 6
Dependent Claim
52 words
A canister purge control method for an internal combustion engine according to claim 1, wherein said correcting of said air-fuel ratio feedback control quantity according to said target air-fuel ratio feedback control quantity calculated comprises adjusting of said air-fuel ratio feedback control quantity to said target air-fuel ratio feedback control quantity calculated.
Claim 7
Dependent Claim
42 words
A canister purge control method for an internal combustion engine according to claim 1, wherein when a change quantity of said purge rate is greater than a predetermined value, an operational condition of said engine is determined as said transient operational condition.
Claim 8
Dependent Claim
143 words
A canister purge control apparatus for an internal combustion engine, including fuel vapor recovering means for temporarily recovering a fuel vapor generated in a fuel tank, means for purging said recovered fuel vapor to said engine during operation of said engine with a purge air quantity being controlled at a purge rate proportional to an air quantity supplied to said engine, and means for feedback controlling an air-fuel ratio; said apparatus comprising: means for estimating a purge air-fuel ratio according to said purge rate and a feedback control quantity of said air-fuel ratio; and means for calculating a target air-fuel ratio feedback control quantity according to said purge air-fuel ratio estimated and said purge rate in a transient operational condition of said engine, and correcting said feedback control quantity of said air-fuel ratio according to said target air-fuel ratio feedback control quantity calculated.
Claim 9
Dependent Claim
143 words
A canister purge control apparatus for an internal combustion engine, including fuel vapor recovering means for temporarily recovering a fuel vapor generated in a fuel tank, means for purging said recovered fuel vapor to said engine during operation of said engine with a purge air quantity being controlled at a purge rate proportional to an air quantity supplied to said engine, and means for feedback controlling an air-fuel ratio; said apparatus comprising: means for estimating a purge air-fuel ratio according to said purge rate and a feedback control quantity of said air-fuel ratio; and means for calculating a target air-fuel ratio feedback control quantity according to said purge air-fuel ratio estimated and said purge rate in a transient operational condition of said engine, and correcting said feedback control quantity of said air-fuel ratio according to said target air-fuel ratio feedback control quantity calculated.
Claim 10
Dependent Claim
57 words
A canister purge control apparatus for an internal combustion engine according to claim 7, wherein when a difference between said air-fuel ratio feedback control quantity and said target air-fuel ratio feedback control quantity is greater than a predetermined value, said air-fuel ratio feedback control quantity is corrected according to said target air-fuel ratio feedback control quantity calculated.
Claim 11
Dependent Claim
52 words
A canister purge control apparatus for an internal combustion engine according to claim 8, wherein said correcting of said air-fuel ratio feedback control quantity according to said target air-fuel ratio feedback control quantity calculated comprises adjusting of said air-fuel ratio feedback control quantity to said target air-fuel ratio feedback control quantity calculated.
Claim 12
Dependent Claim
42 words
A canister purge control apparatus for an internal combustion engine according to claim 9, wherein when a change quantity of said purge rate is greater than a predetermined value, an operational condition of said engine is determined as said transient operational condition.
Claim 13
Dependent Claim
42 words
A canister purge control apparatus for an internal combustion engine according to claim 8, wherein when a change quantity of said purge rate is greater than a predetermined value, an operational condition of said engine is determined as said transient operational condition.
Claim 14
Dependent Claim
164 words
A canister purge control apparatus for an internal combustion engine, including fuel vapor recovering means for temporarily recovering a fuel vapor generated in a fuel tank and recovered fuel purging means for purging said fuel vapor recovered by said fuel vapor recovering means to said engine during operation of said engine, said recovered fuel purging means including means for controlling a purge air quantity at a purge rate proportional to an air quantity supplied to said engine and means for feedback controlling an air-fuel ratio by using an air-fuel ratio sensor; said apparatus comprising: means for calculating a purge air-fuel ratio according to said purge rate and a feedback control quantity of said air-fuel ratio in a normal operational condition of said engine; and feedback control quantity adjusting means for adjusting said air-fuel ratio feedback control quantity to a target air-fuel ratio feedback control quantity calculated according to said purge rate and said purge air-fuel ratio in a transient operational condition of said engine.
Claim 15
Dependent Claim
164 words
A canister purge control apparatus for an internal combustion engine, including fuel vapor recovering means for temporarily recovering a fuel vapor generated in a fuel tank and recovered fuel purging means for purging said fuel vapor recovered by said fuel vapor recovering means to said engine during operation of said engine, said recovered fuel purging means including means for controlling a purge air quantity at a purge rate proportional to an air quantity supplied to said engine and means for feedback controlling an air-fuel ratio by using an air-fuel ratio sensor; said apparatus comprising: means for calculating a purge air-fuel ratio according to said purge rate and a feedback control quantity of said air-fuel ratio in a normal operational condition of said engine; and feedback control quantity adjusting means for adjusting said air-fuel ratio feedback control quantity to a target air-fuel ratio feedback control quantity calculated according to said purge rate and said purge air-fuel ratio in a transient operational condition of said engine.
Claim 16
Dependent Claim
60 words
A canister purge control apparatus for an internal combustion engine according to claim 11, wherein said feedback control quantity adjusting means adjusts said air-fuel ratio feedback control quantity to said target air-fuel ratio feedback control quantity when a difference between said air-fuel ratio feedback control quantity and said target air-fuel ratio feedback control quantity is greater than a predetermined value.
Claim 17
Dependent Claim
52 words
A canister purge control apparatus for an internal combustion engine according to claim 11, wherein said correcting of said air-fuel ratio feedback control quantity according to said target air-fuel ratio feedback control quantity calculated comprises adjusting of said air-fuel ratio feedback control quantity to said target air-fuel ratio feedback control quantity calculated.
Claim 18
Dependent Claim
42 words
A canister purge control apparatus for an internal combustion engine according to claim 13, wherein when a change quantity of said purge rate is greater than a predetermined value, an operational condition of said engine is determined as said transient operational condition.
References Cited (Backward Citations)
US5127383A
Cited
US5172676A
Cited
US5347974A
Cited
US5259353A
Cited
US5351193A
Cited
US5195495A
Cited
US5216991A
Cited
US5297528A
Cited
US5228421A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-27 | 1999-05-29 | 1999-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-27 | 2003-05-29 | 2003-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-27 | 2007-05-29 | 2007-11-28 | $7700.00 | Window Closed / Lapsed |