US5372108A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Engine charge control system and method
Assignee: GM Global Technology Operations LLC
•
Filing: 1993-07-20
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Granted: 1994-12-13
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Expires: 2013-07-20
Abstract
Abstract An engine charge control system operates by initially reducing power from full load by retarding exhaust valve closing timing to increase exhaust gas charge dilution up to the limit for efficient operation. Further load reductions are made by reducing charge mass without increased dilution via alternative steps such as throttling (in conjunction with intake check valves or using individual cylinder valves) or retarding intake valve opening timing without throttling. Partial substitution of external charge dilution is also contemplated.
Inventors
- 👤 Ko-Jen Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:32
CPC Classifications
F; F02; F02D; F02D13/00; F02D13/02; F02D13/0203; F02D13/0215; F02B; F02B29/00; F02B29/02; F02M; F02M26/00; F02M26/01; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027; F02D13/0261; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
169 words
A method of operating a four stroke cycle engine having cylinders each with at least one intake valve and one exhaust valve, pistons in the cylinders and connected with a crankshaft for timed reciprocation, means for varying intake charge pressure provided to the intake valves and means for varying the timing of exhaust valve closing relative to the crank angle of the associated pistons, the method comprising the operating conditions of: providing a desired maximum intake charge pressure to the intake valves and a selected valve timing for operation of the engine at maximum rated power at various operating speeds; reducing power for operation in a high power range immediately below maximum power by increasingly delaying exhaust valve closing up to a maximum delay selected to avoid adversely affecting charge combustion in the cylinders; and completing power reduction for operation in a low power range above idle by reducing intake charge pressure to the intake valves while advancing exhaust valve closing timing back to substantially the initial timing setting.
Claim 2
Independent Claim
169 words
A method of operating a four stroke cycle engine having cylinders each with at least one intake valve and one exhaust valve, pistons in the cylinders and connected with a crankshaft for timed reciprocation, means for varying intake charge pressure provided to the intake valves and means for varying the timing of exhaust valve closing relative to the crank angle of the associated pistons, the method comprising the operating conditions of: providing a desired maximum intake charge pressure to the intake valves and a selected valve timing for operation of the engine at maximum rated power at various operating speeds; reducing power for operation in a high power range immediately below maximum power by increasingly delaying exhaust valve closing up to a maximum delay selected to avoid adversely affecting charge combustion in the cylinders; and completing power reduction for operation in a low power range above idle by reducing intake charge pressure to the intake valves while advancing exhaust valve closing timing back to substantially the initial timing setting.
Claim 3
Dependent Claim
39 words
The invention as in claim 1 and further including reducing power from the high power range in an intermediate power range above the low power range by reducing intake charge pressure while maintaining exhaust valve closing delay substantially constant.
Claim 4
Dependent Claim
33 words
The invention as in claim 1 wherein each cylinder has at least two exhaust valves and the exhaust valve closing timing of at least one of the valves remains constant during engine operation.
Claim 5
Dependent Claim
20 words
The invention as in claim 1 wherein control of the intake charge pressure is provided by a manifold intake throttle.
Claim 6
Dependent Claim
20 words
The invention as in claim 1 wherein control of the intake charge pressure is provided by cylinder intake runner throttles.
Claim 7
Dependent Claim
21 words
The invention as in claim 1 wherein control of the exhaust valve closing timing is provided by variable valve timing mechanism.
Claim 8
Dependent Claim
36 words
The invention as in claim 1 wherein control of the exhaust valve closing timing is provided by camshaft phase changing means which alters the timing of a camshaft that actuates exhaust valves of the engine cylinders.
Claim 9
Dependent Claim
16 words
The invention as in claim 7 wherein the camshaft also actuates intake valves of the cylinders.
Claim 10
Dependent Claim
31 words
The invention as in claim 7 wherein control of the intake charge pressure is provided by a manifold intake throttle together with cylinder intake check valves upstream of the intake valves.
Claim 11
Dependent Claim
176 words
A four stroke cycle engine including cylinders each with at least one intake valve and one exhaust valve, pistons in the cylinders and connected with a crankshaft for timed reciprocation, the engine further comprising means for varying intake charge pressure provided to the intake valves, means for varying the timing of exhaust valve closing relative to the crank angle of the associated pistons, and means for operating the engine according to a method including the operating conditions of: providing a desired maximum intake charge pressure to the intake valves and a selected valve timing for operation of the engine at maximum rated power at various operating speeds; reducing power for operation in a high power range immediately below maximum power by increasingly delaying exhaust valve closing up to a maximum delay selected to avoid adversely affecting charge combustion in the cylinders; and completing power reduction for operation in a low power range above idle by reducing intake charge pressure to the intake valves and advancing exhaust valve closing timing back to substantially the initial timing setting.
Claim 12
Dependent Claim
176 words
A four stroke cycle engine including cylinders each with at least one intake valve and one exhaust valve, pistons in the cylinders and connected with a crankshaft for timed reciprocation, the engine further comprising means for varying intake charge pressure provided to the intake valves, means for varying the timing of exhaust valve closing relative to the crank angle of the associated pistons, and means for operating the engine according to a method including the operating conditions of: providing a desired maximum intake charge pressure to the intake valves and a selected valve timing for operation of the engine at maximum rated power at various operating speeds; reducing power for operation in a high power range immediately below maximum power by increasingly delaying exhaust valve closing up to a maximum delay selected to avoid adversely affecting charge combustion in the cylinders; and completing power reduction for operation in a low power range above idle by reducing intake charge pressure to the intake valves and advancing exhaust valve closing timing back to substantially the initial timing setting.
Claim 13
Dependent Claim
42 words
The invention as in claim 10 wherein the operating conditions further include reducing power from the high power range in an intermediate power range above the low power range by reducing intake charge pressure while maintaining exhaust valve closing delay substantially constant.
Claim 14
Dependent Claim
33 words
The invention as in claim 10 wherein each cylinder has at least two exhaust valves and the exhaust valve closing timing of at least one of the valves remains constant during engine operation.
Claim 15
Dependent Claim
26 words
The invention as in claim 10 and further including a manifold intake throttle actuated by the operating means to provide control of the intake charge pressure.
Claim 16
Dependent Claim
26 words
The invention as in claim 10 and further including cylinder intake runner throttles actuated by the operating means to provide control of the intake charge pressure.
Claim 17
Dependent Claim
27 words
The invention as in claim 10 and further including variable valve timing mechanism actuated by the operating means to provide control of the exhaust valve closing timing.
Claim 18
Dependent Claim
47 words
The invention as in claim 10 and further including camshaft phase changing means operable to vary the timing of a camshaft that actuates exhaust valves of the cylinders, the phase changing means being actuated by the operating means to provide control of the exhaust valve closing timing.
Claim 19
Dependent Claim
16 words
The invention as in claim 16 wherein the camshaft also actuates intake valves of the cylinders.
Claim 20
Dependent Claim
28 words
The invention as in claim 10 wherein the means for varying intake charge pressure include cylinder intake check valves upstream of the intake valves in cylinder intake passages.
Claim 21
Dependent Claim
13 words
The invention as in claim 18 wherein the check valves are reed valves.
Claim 22
Dependent Claim
24 words
The invention as in claim 4 wherein intake charge pressure is determined in part by cylinder intake check valves upstream of the intake valves.
Claim 23
Independent Claim
177 words
A method of operating a four stroke cycle engine having cylinders each with at least one intake valve and one exhaust valve, pistons in the cylinders and connected with a crankshaft for timed reciprocation, means for varying intake charge pressure provided to the intake valves and means for varying the timing of exhaust valve closing relative to the crank angle of the associated pistons, the method comprising the operating conditions of: providing a desired maximum intake charge pressure to the intake valves and a selected valve timing for operation of the engine at maximum rated power at various operating speeds; reducing power for operation in a high power range immediately below maximum power by increasingly delaying exhaust valve closing combined, at least in part, with proportionally delaying intake valve opening up to a maximum delay selected to avoid adversely affecting charge combustion in the cylinders; and completing power reduction for operation in a low power range above idle by further delaying intake valve opening and advancing exhaust valve closing timing back to substantially the initial timing setting.
Claim 24
Independent Claim
177 words
A method of operating a four stroke cycle engine having cylinders each with at least one intake valve and one exhaust valve, pistons in the cylinders and connected with a crankshaft for timed reciprocation, means for varying intake charge pressure provided to the intake valves and means for varying the timing of exhaust valve closing relative to the crank angle of the associated pistons, the method comprising the operating conditions of: providing a desired maximum intake charge pressure to the intake valves and a selected valve timing for operation of the engine at maximum rated power at various operating speeds; reducing power for operation in a high power range immediately below maximum power by increasingly delaying exhaust valve closing combined, at least in part, with proportionally delaying intake valve opening up to a maximum delay selected to avoid adversely affecting charge combustion in the cylinders; and completing power reduction for operation in a low power range above idle by further delaying intake valve opening and advancing exhaust valve closing timing back to substantially the initial timing setting.
Claim 25
Dependent Claim
25 words
The invention as in claim 21 wherein an initial portion of the reduction from maximum power is accomplished while maintaining intake valve opening timing constant.
Claim 26
Independent Claim
165 words
A method of operating a four stroke cycle engine having cylinders each with at least one intake valve and one exhaust valve, pistons in the cylinders are connected with a crankshaft for timed reciprocation, means for varying the timing of exhaust valve closing relative to the crank angle of the associated pistons, the method comprising the operating conditions of: providing a desired maximum intake charge pressure to the intake valves and a selected valve timing for operation of the engine at maximum rated power at various operating speeds; reducing power for operation in a high power range immediately below minimum power by increasingly delaying exhaust valve closing combined, at least in part, with proportionally delaying intake valve opening up to a maximum delay selected to avoid adversely affecting charge combustion in the cylinders; and completing power reduction for operation in a low power range above idle by further delaying intake valve opening and advancing exhaust valve closing timing back to substantially the initial timing setting.
Claim 27
Independent Claim
165 words
A method of operating a four stroke cycle engine having cylinders each with at least one intake valve and one exhaust valve, pistons in the cylinders are connected with a crankshaft for timed reciprocation, means for varying the timing of exhaust valve closing relative to the crank angle of the associated pistons, the method comprising the operating conditions of: providing a desired maximum intake charge pressure to the intake valves and a selected valve timing for operation of the engine at maximum rated power at various operating speeds; reducing power for operation in a high power range immediately below minimum power by increasingly delaying exhaust valve closing combined, at least in part, with proportionally delaying intake valve opening up to a maximum delay selected to avoid adversely affecting charge combustion in the cylinders; and completing power reduction for operation in a low power range above idle by further delaying intake valve opening and advancing exhaust valve closing timing back to substantially the initial timing setting.
Claim 28
Dependent Claim
25 words
The invention as in claim 21 wherein an initial portion of the reduction from maximum power is accomplished while maintaining intake valve opening timing constant.
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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) | 1997-12-12 | 1998-06-13 | 1998-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-12 | 2002-06-13 | 2002-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-12 | 2006-06-13 | 2006-12-13 | $7700.00 | Window Closed / Lapsed |