US5368002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for controlling a flow of evaporated fuel from a canister to an intake passage of an engine
Assignee: Toyota Motor Corp
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Filing: 1993-06-25
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Granted: 1994-11-29
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Expires: 2013-06-25
Abstract
Abstract An evaporated fuel purge control apparatus includes a purge control valve arranged in a purge passage between a canister and an intake passage of an engine, the purge control valve being switched on and off in accordance with a control factor, the control factor indicating a duty ratio of an on-time of the purge control valve within a duty cycle to a total duty-cycle time, a detecting part for detecting an operating condition under which the engine is operating, and a flow rate control part for setting a control factor for the purge control valve in accordance with the operating condition detected by the detecting part, the control factor set by the flow rate control part allowing a flow rate of evaporated fuel fed from the canister into the intake passage through the purge control valve to be maintained at a constant level when the operating condition of the engine changes.
Inventors
- 👤 Shinichi Hoshino
- 👤 Koji Okawa
- 👤 Akinori Osanai
- 👤 Takaaki Itou
- 👤 Yoshihiko Hyodo
- 👤 Toru Kidokoro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:25
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/0025; F02D41/003; F02D41/0045; F02D41/0032; F02M; F02M25/00; F02M25/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
226 words
An apparatus for controlling a flow of evaporated fuel fed from a canister into an intake passage of an engine through a purge control valve, said apparatus comprising: a purge control valve arranged in a purge passage between the canister and the intake passage, said purge control valve switchable between on and off positions in accordance with a duty ratio control factor, said duty ratio control factor indicating a duty ratio of an on-time of said purge control valve within a duty cycle to a total duty-cycle time; detecting means for detecting an operating condition under which the engine is operating; and flow rate control means for setting a purge flow rate control factor for said purge control valve in accordance with the engine operating condition detected by said detecting means, said purge flow rate control factor set by said flow rate control means allowing a flow rate of evaporated fuel from the canister into the intake passage through the purge control valve to be maintained at a constant level when the engine operating condition changes; wherein said flow rate control means sets a purge flow rate correction control factor for the purge control valve when said detecting means detects that a fuel vapor concentration factor is smaller than a given value and that a fuel vapor concentration setting count is greater than a given number.
Claim 2
Independent Claim
226 words
An apparatus for controlling a flow of evaporated fuel fed from a canister into an intake passage of an engine through a purge control valve, said apparatus comprising: a purge control valve arranged in a purge passage between the canister and the intake passage, said purge control valve switchable between on and off positions in accordance with a duty ratio control factor, said duty ratio control factor indicating a duty ratio of an on-time of said purge control valve within a duty cycle to a total duty-cycle time; detecting means for detecting an operating condition under which the engine is operating; and flow rate control means for setting a purge flow rate control factor for said purge control valve in accordance with the engine operating condition detected by said detecting means, said purge flow rate control factor set by said flow rate control means allowing a flow rate of evaporated fuel from the canister into the intake passage through the purge control valve to be maintained at a constant level when the engine operating condition changes; wherein said flow rate control means sets a purge flow rate correction control factor for the purge control valve when said detecting means detects that a fuel vapor concentration factor is smaller than a given value and that a fuel vapor concentration setting count is greater than a given number.
Claim 3
Independent Claim
255 words
An apparatus for controlling a flow of evaporated fuel fed from a canister into an intake passage of an engine through a purge control valve, said apparatus comprising: a purge control valve arranged in a purge passage between the canister and the intake passage, said purge control valve switchable between on and off positions in accordance with a duty ratio control factor, said duty ratio control factor indicating a duty ratio of an on-time of said purge control valve within a duty cycle to a total duty-cycle time; detecting means for detecting an operating condition under which the engine is operating; and flow rate control means for setting a purge flow rate control factor for said purge control valve in accordance with the engine operating condition detected by said detecting means, said purge flow rate control factor set by said flow rate control means allowing a flow rate of evaporated fuel from the canister into the intake passage through the purge control valve to be maintained at a constant level when the engine operating condition changes; wherein said flow rate control means sets a purge flow rate correction control factor based on a maximum purge flow rate and a target purge flow rate in accordance with the engine operating condition detected by said detecting means, said maximum purge flow rate being predetermined as a function of an engine load and retrieved from a map stored in a memory, and said target purge flow rate being increased in accordance with a fuel vapor concentration setting count.
Claim 4
Independent Claim
255 words
An apparatus for controlling a flow of evaporated fuel fed from a canister into an intake passage of an engine through a purge control valve, said apparatus comprising: a purge control valve arranged in a purge passage between the canister and the intake passage, said purge control valve switchable between on and off positions in accordance with a duty ratio control factor, said duty ratio control factor indicating a duty ratio of an on-time of said purge control valve within a duty cycle to a total duty-cycle time; detecting means for detecting an operating condition under which the engine is operating; and flow rate control means for setting a purge flow rate control factor for said purge control valve in accordance with the engine operating condition detected by said detecting means, said purge flow rate control factor set by said flow rate control means allowing a flow rate of evaporated fuel from the canister into the intake passage through the purge control valve to be maintained at a constant level when the engine operating condition changes; wherein said flow rate control means sets a purge flow rate correction control factor based on a maximum purge flow rate and a target purge flow rate in accordance with the engine operating condition detected by said detecting means, said maximum purge flow rate being predetermined as a function of an engine load and retrieved from a map stored in a memory, and said target purge flow rate being increased in accordance with a fuel vapor concentration setting count.
Claim 5
Independent Claim
274 words
An apparatus for controlling a flow of evaporated fuel fed from a canister into an intake passage of an engine through a purge control valve, said apparatus comprising: a purge control valve arranged in a purge passage between the canister and the intake passage, said purge control valve switchable between on and off positions in accordance with a duty ratio control factor, said duty ratio control factor indicating a duty ratio of an on-time of said purge control valve within a duty cycle to a total duty-cycle time; detecting means for detecting an operating condition under which the engine is operating; and flow rate control means for setting a purge flow rate control factor for said purge control valve in accordance with the engine operating condition detected by said detecting means, said purge flow rate control factor set by said flow rate control means allowing a flow rate of evaporated fuel from the canister into the intake passage through the purge control valve to be maintained at a constant level when the engine operating condition changes; and purge ratio control means coupled to said detecting means for setting a purge ratio control factor for said purge control valve when said detecting means detects that a fuel vapor concentration factor is not smaller than a given value or when said detecting means detects that a fuel vapor concentration setting count is not greater than a given number, said purge ratio control factor set by said purge ratio control means allowing a purge ratio of evaporated fuel from the canister into the intake passage through the purge control valve to be maintained at a constant level.
Claim 6
Independent Claim
274 words
An apparatus for controlling a flow of evaporated fuel fed from a canister into an intake passage of an engine through a purge control valve, said apparatus comprising: a purge control valve arranged in a purge passage between the canister and the intake passage, said purge control valve switchable between on and off positions in accordance with a duty ratio control factor, said duty ratio control factor indicating a duty ratio of an on-time of said purge control valve within a duty cycle to a total duty-cycle time; detecting means for detecting an operating condition under which the engine is operating; and flow rate control means for setting a purge flow rate control factor for said purge control valve in accordance with the engine operating condition detected by said detecting means, said purge flow rate control factor set by said flow rate control means allowing a flow rate of evaporated fuel from the canister into the intake passage through the purge control valve to be maintained at a constant level when the engine operating condition changes; and purge ratio control means coupled to said detecting means for setting a purge ratio control factor for said purge control valve when said detecting means detects that a fuel vapor concentration factor is not smaller than a given value or when said detecting means detects that a fuel vapor concentration setting count is not greater than a given number, said purge ratio control factor set by said purge ratio control means allowing a purge ratio of evaporated fuel from the canister into the intake passage through the purge control valve to be maintained at a constant level.
Claim 7
Dependent Claim
61 words
An apparatus according to claim 3, wherein said purge ratio control means sets said purge ratio control factor based on a maximum purge ratio and a target purge ratio in accordance with the engine operating condition detected by said detecting means, said maximum purge ratio being determined as the ratio of a maximum purge flow rate to an intake air amount.
Claim 8
Independent Claim
171 words
An apparatus for controlling a flow of evaporated fuel being fed from a canister into an intake passage of an engine through a purge control valve, said apparatus comprising: a purge control valve arranged in a purge passage between the canister and the intake passage, said purge control valve being switched on and off in accordance with a control factor, said control factor indicating a duty ratio of an on-time of said purge control valve within a duty cycle to a total duty-cycle time; detecting means for detecting whether or not the canister is saturated with fuel vapor; and flow rate control means for setting a control factor for said purge control valve when said detecting means detects that the canister is saturated with fuel vapor, said control factor set by said flow rate control means allowing a flow rate of evaporated fuel fed from the canister into the intake passage through the purge control valve to be maintained at a constant level when the canister is saturated with fuel vapor.
Claim 9
Independent Claim
171 words
An apparatus for controlling a flow of evaporated fuel being fed from a canister into an intake passage of an engine through a purge control valve, said apparatus comprising: a purge control valve arranged in a purge passage between the canister and the intake passage, said purge control valve being switched on and off in accordance with a control factor, said control factor indicating a duty ratio of an on-time of said purge control valve within a duty cycle to a total duty-cycle time; detecting means for detecting whether or not the canister is saturated with fuel vapor; and flow rate control means for setting a control factor for said purge control valve when said detecting means detects that the canister is saturated with fuel vapor, said control factor set by said flow rate control means allowing a flow rate of evaporated fuel fed from the canister into the intake passage through the purge control valve to be maintained at a constant level when the canister is saturated with fuel vapor.
Claim 10
Dependent Claim
59 words
An apparatus according to claim 5, wherein said flow rate control means sets a control factor based on a target purge flow rate and a maximum purge ratio in accordance with an operating condition of the engine, said maximum purge ratio being predetermined as a function of an engine load and retrieved from a map stored in a memory.
Claim 11
Dependent Claim
81 words
An apparatus according to claim 5, further comprising purge ratio control means for setting a control factor for said purge control valve when it is detected that the canister is not saturated with fuel vapor, said control factor set by said purge ratio control means allowing a purge ratio of evaporated fuel fed from the canister into the intake passage through the purge control valve to be maintained at a constant level when the canister is not saturated with fuel vapor.
Claim 12
Dependent Claim
53 words
An apparatus according to claim 7, further comprising means for detecting whether or not the engine is operating under an idling condition, said purge ratio control means being allowed to set a control factor for the purge control valve when said means detects that the engine is not operating under an idling condition.
Claim 13
Dependent Claim
53 words
An apparatus according to claim 5, further comprising means for detecting whether or not the engine is operating under an idling condition, said purge ratio control means being allowed to set a control factor for the purge control valve when said means detects that the engine is not operating under an idling condition.
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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) | 1997-11-28 | 1998-05-30 | 1998-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-28 | 2002-05-30 | 2002-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-28 | 2006-05-30 | 2006-11-29 | $7700.00 | Window Closed / Lapsed |