US5680841A
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: 1996-12-24
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Granted: 1997-10-28
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Expires: 2016-12-24
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
2026-11-04 15:14
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: 41
Claim 1
Independent Claim
151 words
An internal combustion engine comprising: 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 a hydraulic fluid control for selectively controlling hydraulic fluid pressure in said hydraulic linkage to selectively modify the openings of said engine cylinder valve in response to said lobe, said hydraulic fluid control being selectively operable to allow said engine cylinder valve to remain completely closed in response to a first one of said lobes and to open in response to a second one of said lobes, each of said plurality of lobes being selectable at various times to be either said first one or said second one of said lobes.
Claim 2
Dependent Claim
151 words
An internal combustion engine comprising: 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 a hydraulic fluid control for selectively controlling hydraulic fluid pressure in said hydraulic linkage to selectively modify the openings of said engine cylinder valve in response to said lobe, said hydraulic fluid control being selectively operable to allow said engine cylinder valve to remain completely closed in response to a first one of said lobes and to open in response to a second one of said lobes, each of said plurality of lobes being selectable at various times to be either said first one or said second one of said lobes.
Claim 3
Dependent Claim
23 words
The apparatus defined in claim 1 wherein said hydraulic fluid control comprises a valve for selectively releasing hydraulic fluid from said hydraulic linkage.
Claim 4
Dependent Claim
19 words
The apparatus defined in claim 2 wherein said valve is an electrically operated valve controlled by electronic control circuitry.
Claim 5
Dependent Claim
14 words
The apparatus defined in claim 3 wherein said electronic control circuitry includes a microprocessor.
Claim 6
Dependent Claim
60 words
The apparatus defined in claim 1 further comprising: 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.
Claim 7
Dependent Claim
49 words
The apparatus defined in claim 5 wherein said supply comprises a hydraulic fluid accumulator for maintaining a quantity of hydraulic fluid at approximately said first pressure, and wherein said hydraulic fluid control comprises an electrically operated valve for selectively releasing hydraulic fluid from said hydraulic linkage to said accumulator.
Claim 8
Dependent Claim
17 words
The apparatus defined in claim 6 further comprising: electronic control circuitry for controlling said electrically operated valve.
Claim 9
Dependent Claim
14 words
The apparatus defined in claim 7 wherein said electronic control circuitry includes a microprocessor.
Claim 10
Dependent Claim
49 words
The apparatus defined in claim 1 wherein said hydraulic linkage comprises: a master piston that reciprocates in response to said lobes; and a slave piston that selectively reciprocates in response to hydraulic fluid pressure and flow in said hydraulic linkage in order to selectively open said engine cylinder valve.
Claim 11
Dependent Claim
23 words
The apparatus defined in claim 1 wherein said hydraulic linkage is disposed in a rocker arm which rocks in response to said lobes.
Claim 12
Dependent Claim
50 words
The apparatus defined in claim 10 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 13
Dependent Claim
24 words
The apparatus defined in claim 1 wherein said hydraulic linkage is disposed in a rocker arm which selectively rocks in response to said lobes.
Claim 14
Dependent Claim
60 words
The apparatus defined in claim 12 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 15
Dependent Claim
92 words
The apparatus 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 hydraulic fluid control 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 16
Dependent Claim
55 words
The apparatus defined in claim 14 wherein said hydraulic fluid control 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 17
Dependent Claim
70 words
The apparatus defined in claim 15 wherein said cam additionally has a reverse exhaust gas flow lobe, and wherein said hydraulic fluid control 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 18
Dependent Claim
45 words
The apparatus defined in claim 1 wherein said hydraulic fluid control selectively delays an opening of said engine cylinder valve in response to one of said lobes by substantially preventing hydraulic fluid pressure increase in said hydraulic linkage during an initial portion of said lobe.
Claim 19
Dependent Claim
46 words
The apparatus defined in claim 1 wherein said hydraulic fluid control selectively reduces the amount by which said engine cylinder valve opens in response to one of said lobes by allowing hydraulic fluid to escape from said hydraulic fluid linkage during a portion of said lobe.
Claim 20
Dependent Claim
48 words
The apparatus defined in claim 1 wherein said hydraulic fluid control selectively advances in time the re-closing of said engine cylinder valve after opening in response to one of said lobes by allowing hydraulic fluid to escape from said hydraulic fluid linkage during a portion of said lobe.
Claim 21
Dependent Claim
40 words
The apparatus defined in claim 1 wherein said engine cylinder valve reciprocates relative to a cylinder head of said engine, and wherein said hydraulic linkage is disposed in a structure which is fixed and stationary relative to said cylinder head.
Claim 22
Independent Claim
177 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, said method comprising the steps of: detecting whether said engine is in a positive power mode of operation or a compression release engine braking mode of operation; 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; and 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 but not in response to said exhaust lobe.
Claim 23
Independent Claim
177 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, said method comprising the steps of: detecting whether said engine is in a positive power mode of operation or a compression release engine braking mode of operation; 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; and 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 but not in response to said exhaust lobe.
Claim 24
Dependent Claim
66 words
The method defined in claim 21 wherein said step of controlling, when said engine is in said positive power mode of operation, comprises the steps of: trapping said hydraulic fluid in said hydraulic linkage during response of said hydraulic linkage to said exhaust lobe; and allowing said hydraulic fluid to escape from said hydraulic linkage during response of said hydraulic linkage to said compression release lobe.
Claim 25
Dependent Claim
68 words
The method defined in claim 21 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 26
Dependent Claim
75 words
The method defined in claim 21 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 27
Dependent Claim
29 words
The method defined in claim 24 wherein said second portion is an initial portion of the response of said hydraulic linkage to said at least one of said lobes.
Claim 28
Dependent Claim
29 words
The method defined in claim 24 wherein said second portion is an intermediate portion of the response of said hydraulic linkage to said at least one of said lobes.
Claim 29
Dependent Claim
14 words
The method defined in claim 26 wherein said first portion precedes said intermediate portion.
Claim 30
Dependent Claim
54 words
The method defined in claim 27 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 31
Dependent Claim
28 words
The method defined in claim 24 wherein said portion is a final portion of the response of said hydraulic linkage to said at least one of said lobes.
Claim 32
Dependent Claim
131 words
A compression release braking system for an internal combustion engine comprising: an engine cylinder exhaust valve which is selectively openable and closable; a cam having a compression release engine braking lobe synchronized with a possible compression release 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 responsive to a variable operating condition of said engine for selectively modifying hydraulic fluid pressure in said hydraulic linkage during response of said hydraulic linkage to said lobe to selectively modify the openings of said exhaust valve in response to said lobe so that said openings are adapted to a current value of said variable operating condition.
Claim 33
Dependent Claim
131 words
A compression release braking system for an internal combustion engine comprising: an engine cylinder exhaust valve which is selectively openable and closable; a cam having a compression release engine braking lobe synchronized with a possible compression release 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 responsive to a variable operating condition of said engine for selectively modifying hydraulic fluid pressure in said hydraulic linkage during response of said hydraulic linkage to said lobe to selectively modify the openings of said exhaust valve in response to said lobe so that said openings are adapted to a current value of said variable operating condition.
Claim 34
Dependent Claim
30 words
The apparatus defined in claim 30 wherein said hydraulic fluid control controls said hydraulic fluid pressure in said hydraulic linkage by selectively releasing hydraulic fluid from said hydraulic fluid linkage.
Claim 35
Dependent Claim
14 words
The apparatus defined in claim 30 wherein said hydraulic fluid control comprises a microprocessor.
Claim 36
Dependent Claim
49 words
The apparatus defined in claim 30 wherein said hydraulic linkage comprises: a master piston reciprocable by said lobe to cause a flow of hydraulic fluid in said hydraulic linkage; and a slave piston reciprocable by hydraulic fluid pressure and flow in said hydraulic linkage to open said exhaust valve.
Claim 37
Dependent Claim
23 words
The apparatus defined in claim 30 wherein said hydraulic linkage is disposed in a rocker arm which is selectively rockable by said lobe.
Claim 38
Dependent Claim
25 words
The apparatus defined in claim 30 wherein said hydraulic fluid control selectively modifies commencement time of said openings relative to commencement time of said lobe.
Claim 39
Dependent Claim
27 words
The apparatus defined in claim 30 wherein said hydraulic fluid control selectively modifies end termination time of said openings relative to end termination time of said lobe.
Claim 40
Dependent Claim
25 words
The apparatus defined in claim 30 wherein said hydraulic fluid control selectively modifies opening distance of said openings relative to profile prominence of said lobe.
Claim 41
Dependent Claim
39 words
The apparatus defined in claim 30 wherein said exhaust valve reciprocates relative to a cylinder head of said engine, and wherein said hydraulic linkage is disposed in a structure which is fixed and stationary relative to said cylinder head.
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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) | 2000-10-27 | 2001-04-28 | 2001-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-27 | 2005-04-28 | 2005-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-27 | 2009-04-28 | 2009-10-28 | $7700.00 | Window Closed / Lapsed |