Transitions among operating modes in an engine with a hybrid valvetrain

• US 6,484,677 B2
• Filed: 02/21/2002
• Issued: 11/26/2002
• Est. Priority Date: 08/29/2000
• Status: Expired due to Term

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Russell, John D., Brehob, Diana Dawn, Leone, Thomas George
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): DAHBOUR, HENRY
• Application Number:
  US10/079,986
• Publication Number:
  US 20020092487A1
• Time in Patent Office: 278 Days
• Field of Search: 123/90.15, 123/90.11, 123/90.12, 123/90.13, 123/90.14, 123/90.16, 123/90.17, 123/308, 123/315, 123/432
• US Class Current: 123/90.15
• 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 13/0005 Deactivating valves
• CPC Class Codes: F01L 2001/0537 Double overhead camshafts [DOHC]
• CPC Class Codes: F01L 2800/00 Methods of operation using a variable valve timing mechanism
• CPC Class Codes: F01L 2820/01 Absolute values
• CPC Class Codes: F01L 9/20 by electric means
• CPC Class Codes: F02D 13/0226 changing valve lift or valve lift and timing
• CPC Class Codes: F02D 13/0234 changing the valve timing only
• CPC Class Codes: F02D 13/0253 Fully variable control of valve lift and timing using camless actuation systems such as hydraulic, pneumatic or electromagnetic actuators, e.g. solenoid valves
• CPC Class Codes: F02D 13/0257 Independent control of two or more intake or exhaust valves respectively, i.e. one of two intake valves remains closed or is opened partially while the other is fully opened
• CPC Class Codes: F02D 13/0269 Controlling the valves to perform a Miller-Atkinson cycle
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02M 25/08 adding fuel vapours drawn from engine fuel reservoir electrical control of purge system F02D41/003
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for controlling intake valves in an internal combustion with intake valves operated by more than one type of actuation device includes steps to accomplish smooth transitions among intake valve operating modes.

Claims

1. A method for controlling an internal combustion engine, the engine having at least one cylinder, at least one randomly operable intake valve, a throttle valve disposed in an air intake system of said engine, and an engine control unit, said method comprising the steps of:

closing the throttle valve and advancing a closing time of said randomly operable intake valve, in the event that said closing time of the randomly operable intake valve is retarded from a predetermined valve closing time; and

closing the throttle valve and retarding a closing time of the randomly operable intake valve, in the event that said closing time of the randomly operable intake valve is advanced from said predetermined valve closing time.

2. The method according to claim 1, wherein said predetermined valve closing is a closing time which maximizes air inducted which is retained in the cylinder after closing of the randomly operable intake valve.

3. The method according to claim 1, wherein said closing of the throttle valve and said closing time of the randomly operable intake valve are selected so that engine torque is substantially constant.

4. The method according to claim 1, wherein a first operating mode precedes said closing of the throttle valve, said first operating mode characterized by a first relationship between engine speed and engine torque.

5. The method according to claim 4, wherein a second operating mode succeeds said closing of the throttle valve, said second operating mode characterized by a second relationship between engine speed and engine torque wherein for a given engine speed said first operating mode provides a higher engine torque than said second operating mode.

6. A method for controlling an internal combustion engine, the engine having at least one cylinder, at least one randomly operable intake valve, a throttle valve disposed in an intake valve system of said engine, and an engine control unit, said method comprising the steps of:

opening the throttle valve and advancing a closing time of the randomly operable intake valve, in the event that said closing time of the randomly operable intake valve is advanced from a predetermined valve closing time; and

opening the throttle valve and retarding said closing time of the randomly operable intake valve, in the event that said closing time of the randomly operable intake is retarded from said predetermined valve closing time.

7. The method according to claim 6, wherein said predetermined valve closing time is a closing time which traps maximum fresh charge.

8. The method according to claim 6, wherein said opening of the throttle valve and said closing time of the randomly operable intake valve are selected so that engine torque is substantially constant.

9. The method according to claim 6, wherein a first operating mode precedes said opening of the throttle valve, said first operating mode characterized by a first relationship between engine speed and engine torque.

10. The method according to claim 9, wherein a second operating mode succeeds said opening of the throttle valve, characterized by a second relationship between engine speed and engine torque, wherein at a given engine speed said second operating mode provides higher engine torque than said first operating mode.

11. A system for controlling an internal combustion engine, the engine having at least one cylinder and a throttle valve disposed in an air intake, comprising:

a randomly operable intake valve coupled to the cylinder; and

an electronic control unit operably connected to the engine, the throttle valve, and said randomly operable intake valve, said electronic control unit commands the throttle valve to close and commands said randomly operable intake valve to close at an advanced timing when said closing time of said randomly operable intake valve is retarded from a predetermined valve closing time.

12. The system of claim 11, wherein said electronic control unit commands said randomly operable intake valve to close at a retarded timing when said closing time of said randomly operable intake valve is advanced from a predetermined valve closing time.

13. The system of claim 12 wherein said predetermined valve closing time is a closing time trapping maximum fresh air in the cylinder.

14. The system of claim 12 wherein a first operating mode precedes said closing of the throttle valve, a second operating mode follows said closing of the throttle valve, and said first operating mode provides a higher engine torque than said second operating mode.

15. The system of claim 14 wherein said closing time of said randomly operable intake valve provides a smooth torque trajectory between said first operating mode and said second operating mode.

16. A system for controlling an internal combustion engine, the engine having at least one cylinder and a throttle valve disposed in an air intake, comprising:

a randomly operable intake valve coupled to the cylinder; and

an electronic control unit operably connected to the engine, the throttle valve, and said randomly operable intake valve, said electronic control unit commands the throttle valve to open and commands said randomly operable intake valve to close at a retarded timing when said closing time of said randomly operable intake valve is retarded from a predetermined valve closing time.

17. The system of claim 16, wherein said electronic control unit commands said randomly operable intake valve to close at an advanced timing when said closing time of said randomly operable intake valve is advanced from a predetermined valve closing time.

18. The system of claim 17 wherein said predetermined valve closing time is a closing time trapping maximum fresh air in the cylinder.

19. The system of claim 17 wherein a first operating mode precedes said closing of the throttle valve, a second operating mode follows said closing of the throttle valve, and said first operating mode provides a lower engine torque than said second operating mode.

20. The system of claim 19 wherein said closing time of said randomly operable intake valve provides a smooth torque trajectory between said first operating mode and said second operating mode.