Apparatus and method for early intake valve closing

• US 6,600,989 B2
• Filed: 05/24/2001
• Issued: 07/29/2003
• Est. Priority Date: 05/24/2001
• Status: Expired due to Term

• Current Assignee: Delphi Technologies Ip Limited (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: Sellnau, Mark C., Sinnamon, James F.
• Primary Examiner(s): Vo, Hieu T.
• Application Number:
  US09/864,657
• Publication Number:
  US 20020177938A1
• Time in Patent Office: 796 Days
• Field of Search: 701/110, 701/102, 701/115, 123/90.15, 123/90.11, 123/90.17
• US Class Current: 701/110
• CPC Class Codes: F01L 1/34 characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
• CPC Class Codes: F01L 13/0015 for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
• CPC Class Codes: F01L 13/0036 the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
• CPC Class Codes: F01L 2201/00 Electronic control systems; Apparatus or methods therefor
• CPC Class Codes: F01L 2800/00 Methods of operation using a variable valve timing mechanism
• CPC Class Codes: F01L 2800/01 Starting
• CPC Class Codes: F02D 13/023 the change of valve timing is caused by the change in valve lift, i.e. both valve lift and timing are functionally related
• CPC Class Codes: F02D 13/0238 by shifting the phase, i.e. the opening periods of the valves are constant
• CPC Class Codes: F02D 13/0261 Controlling the valve overlap
• CPC Class Codes: F02D 13/0269 Controlling the valves to perform a Miller-Atkinson cycle
• CPC Class Codes: F02D 2041/002 by simultaneous control of throttle and variable valve actuation
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/187 using a hot wire flow sensor
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for early intake valve closing in an internal combustion engine having a crankshaft and at least one exhaust valve, the crankshaft having a top dead center position and a bottom dead center position, includes the step of determining engine operating load conditions and parameters. One of a plurality of predetermined valve lift profiles, each of which correspond to a respective range of engine operating load conditions and parameters, is selected dependent at least in part upon the engine operating load conditions and parameters. The engine is commanded to operate the engine intake valves according to the selected one of the plurality of predetermined valve lift profiles to thereby optimize fuel economy and reduce emissions at light to moderate engine loads, to improve torque and power at relatively full engine loads, and improve cold start engine operation under cold start engine conditions.

Claims

1. An EIVC apparatus for use with an internal combustion engine, said engine having a crankshaft and at least one intake valve, a cam shaft associated with said at least one intake valve, said EIVC apparatus comprising:

a pedal module issuing a desired load command;

a respective two-step switching device associated with each of said at least one intake valve, each said two-step switching device being switchable between a high-lift position and a low-lift position;

a cam phaser associated with said cam shaft, said cam phaser being operable to change a phase of said cam shaft relative to said crankshaft; and

an engine control module electrically interconnected with said pedal module, said two-step switching device and said cam phaser, said engine control module having a memory; and

a computer program stored in said memory of said engine control module, said computer program being executable by said engine control module, said engine control module executing said computer program to thereby configure dependent at least in part upon engine operating conditions and parameters said two-step switching device and said cam phaser to produce a selected one of a plurality of predetermined intake valve lift profiles configured for at least one of optimizing fuel economy and emissions under approximately light to approximately moderate engine operating loads, improving torque and power at approximately full engine operating loads, and providing maximum valve overlap and maximum engine efficiency under cold start engine operating conditions.

2. The EIVC apparatus of claim 1, further comprising:

an electronic throttle control having a control input and a throttle position sensor electrically connected to said engine control module; and

a mass air flow sensor electrically connected to said ECM.

3. The EIVC apparatus of claim 1, wherein said computer program comprises:

a reading module, said reading module reading at least one of a load command signal, a mass air flow sensor signal, a throttle position sensor signal, a cam position sensor signal, an oil pressure sensor signal and a coolant temperature sensor signal to thereby determine an engine operating load;

a look-up module wherein one of said plurality of predetermined valve lift profiles is selected dependent at least in part upon said engine operating load; and

a command module commanding the engine to operate the engine intake valves according to said one of said plurality of predetermined valve lift profiles.

4. A method of early intake valve closing for an internal combustion engine, said engine including a crankshaft and at least one exhaust valve, said crankshaft having a top dead center position and a bottom dead center position, said method comprising the steps of:

determining engine operating load conditions and parameters;

selecting one of a plurality of predetermined valve lift profiles, each of said plurality of predetermined valve lift profiles corresponding to a respective range of engine operating load conditions and parameters, said selected one of said plurality of predetermined valve lift profiles being selected dependent at least in part upon said engine operating load conditions and parameters; and

commanding the engine to operate the engine intake valves according to said selected one of said plurality of predetermined valve lift profiles.

5. The method of claim 4, wherein said determining step comprises an engine control module electrically connected to and reading at least one of a load command signal, a mass air flow sensor signal, a throttle position sensor signal, a cam position sensor signal, an oil pressure sensor signal and a coolant temperature sensor signal.

6. The method of claim 5, further comprising the step of comparing at least one of said load command signal, said mass air flow sensor signal, a throttle position sensor signal, a cam position sensor signal, an oil pressure sensor signal and a coolant temperature sensor signal with predetermined ranges of values therefor to thereby determine said range of engine operating load conditions and parameters, said selected one of a plurality of predetermined valve lift profiles corresponding to said range of engine operating load conditions and parameters.

7. The method of claim 4, wherein said plurality of predetermined valve lift profiles are configured for at least one of optimizing fuel economy and emissions under approximately light to approximately moderate engine operating loads, improving torque and power at approximately full engine operating loads, and providing minimum valve overlap and maximum engine combustion efficiency under cold start engine operating conditions.

8. The method of claim 4, wherein said commanding step comprises:

issuing a two-step control signal to thereby place a two-step switching device into one of a high lift long duration and a low lift short duration position; and

issuing a phaser control signal to position a cam phaser.

9. The method of claim 8, wherein said low-lift position provides from approximately thirty percent to approximately fifty percent of the lift of said high-lift position, and from approximately forty percent to approximately sixty percent of the duration of the high-lift position.

10. The method of claim 8, wherein said commanding step further comprises issuing an electronic throttle control signal to an electronic throttle control module to position a main throttle valve.

11. The method of claim 8, wherein said determining step indicates a cold start engine operating condition, said commanding step comprising:

issuing said two-step control signal to thereby place said two-step switching device into said low lift position; and

issuing said phaser control signal to thereby position said cam phaser in a full retard position.

12. The method of claim 11, wherein said full retard position opens the engine intake valves at from approximately fifteen degrees after top dead center to approximately forty five degrees after top dead center and closing at approximately fifteen degrees prior to approximately fifteen degrees subsequent to bottom dead center.

13. The method of claim 8, wherein said determining step indicates a light to moderate engine load operating condition, said commanding step comprising:

issuing said two-step control signal to thereby place said two-step switching device into said low lift position; and

issuing said phaser control signal to thereby position said cam phaser in a predetermined advanced position, said predetermined advanced position selected to optimize fuel economy and reduce emissions.

14. The method of claim 13, wherein said predetermined advanced position opens the engine intake valves at from approximately sixty degrees before top dead center to approximately thirty degrees before top dead center and closing at from approximately ninety degrees after to approximately one hundred twenty degrees after bottom dead center.

15. The method of claim 8, wherein said determining step indicates a full engine load and low-speed operating condition, said commanding step comprising:

issuing said two-step control signal to thereby place said two-step switching device into said high lift position; and

issuing said phaser control signal to thereby position said cam phaser in a predetermined advanced position, said predetermined advanced position selected to optimize engine torque.

16. The method of claim 15, wherein said predetermined advanced position opens the engine intake valves at from approximately seventy degrees before top dead center to approximately fifty degrees before top dead center and closing at from approximately twenty degrees after to approximately fifty degrees after bottom dead center.

17. The method of claim 8, wherein said determining step indicates a full engine load and high-speed operating condition, said commanding step comprising:

issuing said two-step control signal to thereby place said two-step switching device into said high lift position; and

issuing said phaser control signal to thereby position said cam phaser in a predetermined moderately retarded position, said predetermined moderately retarded position selected to optimize engine power output.

18. The method of claim 17, wherein said predetermined moderately advanced position opens the engine intake valves at from approximately thirty degrees before top dead center to approximately top dead center and closing at approximately sixty degrees to approximately ninety after bottom dead center.