US5839453A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Internal combustion engines with combined cam and electro-hydraulic engine valve control
Assignee: Diesel Engine Retarders Inc
•
Filing: 1997-10-22
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Granted: 1998-11-24
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Expires: 2017-10-22
Abstract
Abstract An internal combustion engine has electrically controlled hydraulic linkages between engine cams and engine cylinder valves. If it is desired to skip a cam lobe or to modify the response of an engine cylinder valve to a cam lobe, hydraulic fluid is selectively released from the associated hydraulic linkage to permit lost motion between the cam and the engine cylinder valve. Electrically controlled hydraulic fluid valves are used to produce the selective release of hydraulic fluid from the hydraulic linkages. The mode of operation of the engine can be changed (e.g., from positive power mode to compression release engine braking mode or vice versa), or more subtle changes can be made to modify the timing and/or extent of engine cylinder valve openings to optimize engine performance for various engine or vehicle operating conditions (e.g., different engine or vehicle speeds).
Inventors
- 👤 Haoran Hu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:10
CPC Classifications
F; F01; F01L; F01L1/00; F01L1/12; F01L1/18; F01L1/181; F01L1/20; F01L1/22; F01L1/24; F01L1/2422; F01L13/00; F01L13/06; F01L13/065; F01L9/00; F01L9/10; F01L9/11; F01L9/12; F01L9/14; F01L1/02; F01L1/04; F01L1/08; F01L1/14; F01L1/143; F01L1/46; F01L1/462; F01L1/34; F01L1/344; F01L1/3442; F01L2001/34423; F01L2001/34446; F01L2305/00
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
176 words
An internal combustion engine having a four-cycle positive power mode and including an engine cylinder valve which is selectively openable and closable, a cam having a plurality of lobes synchronized with possible openings of said engine cylinder valve, a hydraulic linkage containing hydraulic fluid operatively coupled between said cam and said engine cylinder valve for selectively responding to said lobes by causing said valve to open, and an electrically operated valve controlled by an electronic control circuitry for selectively releasing hydraulic fluid from said hydraulic linkage in order to selectively modify the openings of said engine cylinder valve in response to said lobes, said electrically operated valve being selectively operable to allow said engine cylinder valve to remain completely closed in response to any first one of said lobes and to open in response to any second one of said lobes, characterized in that said electrically operated valve is openable and closable multiple times during each time period of operation of said engine comparable to each four cycles of positive power mode operation of said engine.
Claim 2
Dependent Claim
176 words
An internal combustion engine having a four-cycle positive power mode and including an engine cylinder valve which is selectively openable and closable, a cam having a plurality of lobes synchronized with possible openings of said engine cylinder valve, a hydraulic linkage containing hydraulic fluid operatively coupled between said cam and said engine cylinder valve for selectively responding to said lobes by causing said valve to open, and an electrically operated valve controlled by an electronic control circuitry for selectively releasing hydraulic fluid from said hydraulic linkage in order to selectively modify the openings of said engine cylinder valve in response to said lobes, said electrically operated valve being selectively operable to allow said engine cylinder valve to remain completely closed in response to any first one of said lobes and to open in response to any second one of said lobes, characterized in that said electrically operated valve is openable and closable multiple times during each time period of operation of said engine comparable to each four cycles of positive power mode operation of said engine.
Claim 3
Dependent Claim
14 words
The engine defined in claim 1 wherein said electronic control circuitry includes a microprocessor.
Claim 4
Dependent Claim
100 words
The engine defined in claim 1 further including a supply of hydraulic fluid at a first, relatively low, positive pressure, and a check valve for allowing said hydraulic fluid to flow from said supply into said hydraulic linkage but not in an opposite direction, said first pressure being insufficient to cause said hydraulic linkage to open said engine cylinder valve, further characterized in that said supply comprises a hydraulic fluid accumulator for maintaining a quantity of hydraulic fluid at approximately said first pressure, and wherein said electrically operated valve selectively releases hydraulic fluid from said hydraulic linkage to said accumulator.
Claim 5
Dependent Claim
23 words
The engine defined in claim 1 wherein said hydraulic linkage is disposed in a rocker arm which rocks in response to said lobes.
Claim 6
Dependent Claim
50 words
The engine defined in claim 4 wherein said hydraulic linkage comprises a slave piston disposed in said rocker arm, said slave piston being reciprocable relative to said rocker arm in response to hydraulic fluid pressure and flow in said hydraulic linkage in order to selectively open said engine cylinder valve.
Claim 7
Dependent Claim
24 words
The engine defined in claim 1 wherein said hydraulic linkage is disposed in a rocker arm which selectively rocks in response to said lobes.
Claim 8
Dependent Claim
60 words
The engine defined in claim 6 wherein said hydraulic linkage comprises a master piston that is reciprocable relative to said rocker arm in response to said lobes, and a slave piston that is reciprocable relative to said rocker arm in response to hydraulic fluid pressure and flow in said hydraulic linkage in order to selectively open said engine cylinder valve.
Claim 9
Dependent Claim
92 words
The engine defined in claim 1 wherein said engine cylinder valve is an exhaust valve, wherein said lobes include an exhaust lobe and a compression release lobe, and wherein said electrically operated valve is responsive to whether said engine is in a positive power mode of operation or a compression release engine braking mode of operation by controlling hydraulic fluid pressure in said hydraulic linkage so that said exhaust valve opens in response to said compression release lobe only when said engine is in said compression release engine braking mode of operation.
Claim 10
Dependent Claim
55 words
The engine defined in claim 8 wherein said electrically operated valve is further responsive to the mode of operation of said engine by controlling hydraulic fluid pressure in said hydraulic linkage so that said exhaust valve opens in response to said exhaust lobe only when said engine is in said positive power mode of operation.
Claim 11
Dependent Claim
70 words
The engine defined in claim 8 wherein said cam additionally has a reverse exhaust gas flow lobe, and wherein said electrically operated valve is further responsive to the mode of operation of said engine by controlling hydraulic fluid pressure in said hydraulic linkage so that said exhaust valve opens in response to said reverse exhaust gas flow lobe only when said engine is in said compression release engine braking mode.
Claim 12
Dependent Claim
47 words
The engine defined in claim 1 wherein said electrically operated valve selectively delays an opening of said engine cylinder valve in response to said second one of said lobes by substantially preventing hydraulic fluid pressure increase in said hydraulic linkage during an initial portion of said lobe.
Claim 13
Dependent Claim
47 words
The engine defined in claim 1 wherein said electrically operated valve selectively reduces the amount by which said engine cylinder valve opens in response to said second one of said lobes by allowing hydraulic fluid to escape from said hydraulic linkage during a portion of said lobe.
Claim 14
Dependent Claim
49 words
The engine defined in claim 1 wherein said electrically operated valve selectively advances in time the re-closing of said engine cylinder valve after opening in response to said second one of said lobes by allowing hydraulic fluid to escape from said hydraulic linkage during a portion of said lobe.
Claim 15
Independent Claim
205 words
The method of operating an internal combustion engine which has a selectively openable engine cylinder valve, a cam having an exhaust lobe and a compression release lobe, and a hydraulic linkage containing hydraulic fluid operatively coupled between said cam and said engine cylinder valve for selectively responding to said exhaust and compression release lobes by selectively opening said engine cylinder valve, the method including the steps of detecting whether said engine is in a positive power mode of operation or a compression release engine braking mode of operation, and if said engine is in said positive power mode of operation, controlling hydraulic fluid pressure in said hydraulic linkage so that said hydraulic linkage opens said engine cylinder valve in response to said exhaust lobe but not in response to said compression release lobe, or if said engine is in said compression release mode of operation, controlling hydraulic fluid pressure in said hydraulic linkage so that said hydraulic linkage opens said engine cylinder valve in response to said compression release lobe, characterized in that in said compression release mode of operation, the hydraulic fluid pressure in said hydraulic linkage is controlled so that said engine cylinder valve does not open in response to said exhaust lobe.
Claim 16
Independent Claim
205 words
The method of operating an internal combustion engine which has a selectively openable engine cylinder valve, a cam having an exhaust lobe and a compression release lobe, and a hydraulic linkage containing hydraulic fluid operatively coupled between said cam and said engine cylinder valve for selectively responding to said exhaust and compression release lobes by selectively opening said engine cylinder valve, the method including the steps of detecting whether said engine is in a positive power mode of operation or a compression release engine braking mode of operation, and if said engine is in said positive power mode of operation, controlling hydraulic fluid pressure in said hydraulic linkage so that said hydraulic linkage opens said engine cylinder valve in response to said exhaust lobe but not in response to said compression release lobe, or if said engine is in said compression release mode of operation, controlling hydraulic fluid pressure in said hydraulic linkage so that said hydraulic linkage opens said engine cylinder valve in response to said compression release lobe, characterized in that in said compression release mode of operation, the hydraulic fluid pressure in said hydraulic linkage is controlled so that said engine cylinder valve does not open in response to said exhaust lobe.
Claim 17
Dependent Claim
68 words
The method defined in claim 14 wherein said step of controlling, when said engine is in said compression release engine braking mode of operation, comprises the steps of trapping said hydraulic fluid in said hydraulic linkage during response of said hydraulic linkage to said compression release lobe, and allowing said hydraulic fluid to escape from said hydraulic linkage during response of said hydraulic linkage to said exhaust lobe.
Claim 18
Dependent Claim
75 words
The method defined in claim 14 wherein at least one of said controlling steps comprises the steps of trapping said hydraulic fluid in said hydraulic linkage during a first portion of response of said hydraulic linkage to at least one of said lobes, and allowing some of said hydraulic fluid to escape from said hydraulic linkage during a second portion of the response of said hydraulic linkage to said at least one of said lobes.
Claim 19
Dependent Claim
29 words
The method defined in claim 16 wherein said second portion is an initial portion of the response of said hydraulic linkage to said at least one of said lobes.
Claim 20
Dependent Claim
29 words
The method defined in claim 16 wherein said second portion is an intermediate portion of the response of said hydraulic linkage to said at least one of said lobes.
Claim 21
Dependent Claim
14 words
The method defined in claim 18 wherein said first portion precedes said intermediate portion.
Claim 22
Dependent Claim
54 words
The method defined in claim 19 wherein said at least one of said controlling steps further comprises the step of retrapping said hydraulic fluid in said hydraulic linkage during a third portion of the response of said hydraulic linkage to said at least one of said lobes, said third portion following said intermediate portion.
Claim 23
Dependent Claim
28 words
The method defined in claim 16 wherein said portion is a final portion of the response of said hydraulic linkage to said at least one of said lobes.
Claim 24
Dependent Claim
159 words
A compression release braking system for an internal combustion engine including an engine cylinder exhaust valve which is selectively openable and closable, a cam having a lobe synchronized with a possible opening of said exhaust valve, a hydraulic linkage containing hydraulic fluid operatively coupled between said cam and said exhaust valve for selectively responding to said lobe by causing said valve to open, and a hydraulic fluid control having a plurality of different operating conditions in which the hydraulic fluid control has respective different effects on the hydraulic fluid pressure in said hydraulic linkage in response to said lobe, characterized in that said lobe is a compression release engine braking lobe synchronized with a possible compression release opening of said exhaust valve, and the hydraulic fluid control is responsive to a variable operating condition of said engine by changing said operating conditions of said hydraulic fluid control at different times during response of the hydraulic linkage to said lobe.
Claim 25
Dependent Claim
159 words
A compression release braking system for an internal combustion engine including an engine cylinder exhaust valve which is selectively openable and closable, a cam having a lobe synchronized with a possible opening of said exhaust valve, a hydraulic linkage containing hydraulic fluid operatively coupled between said cam and said exhaust valve for selectively responding to said lobe by causing said valve to open, and a hydraulic fluid control having a plurality of different operating conditions in which the hydraulic fluid control has respective different effects on the hydraulic fluid pressure in said hydraulic linkage in response to said lobe, characterized in that said lobe is a compression release engine braking lobe synchronized with a possible compression release opening of said exhaust valve, and the hydraulic fluid control is responsive to a variable operating condition of said engine by changing said operating conditions of said hydraulic fluid control at different times during response of the hydraulic linkage to said lobe.
Claim 26
Dependent Claim
14 words
The system defined in claim 22 wherein said hydraulic fluid control comprises a microprocessor.
Claim 27
Dependent Claim
23 words
The system defined in claim 22 wherein said hydraulic linkage is disposed in a rocker arm which is selectively rockable by said lobe.
Claim 28
Dependent Claim
25 words
The system defined in claim 22 wherein said hydraulic fluid control selectively modifies commencement time of said openings relative to commencement time of said lobe.
Claim 29
Dependent Claim
27 words
The system defined in claim 22 wherein said hydraulic fluid control selectively modifies end termination time of said openings relative to end termination time of said lobe.
Claim 30
Dependent Claim
25 words
The system defined in claim 22 wherein said hydraulic fluid control selectively modifies opening distance of said openings relative to profile prominence of said lobe.
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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) | 2001-11-23 | 2002-05-25 | 2002-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-23 | 2006-05-25 | 2006-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-23 | 2010-05-25 | 2010-11-24 | $7700.00 | Window Closed / Lapsed |