Method for balancing engine cylinder bank output using crankshaft sensing and intake cam phasing

• US 6,843,214 B1
• Filed: 11/04/2003
• Issued: 01/18/2005
• Est. Priority Date: 11/04/2003
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Herrin, Ronald J.
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): Eshete, Zelalem
• Application Number:
  US10/700,975
• Time in Patent Office: 441 Days
• Field of Search: 123/90.15, 123/90.16, 123/90.17, 123/90.31
• US Class Current: 123/90.15
• CPC Class Codes: F01L 1/022 Chain drive
• 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 1/46 Component parts, details, or accessories, not provided for in preceding subgroups
• CPC Class Codes: F01L 2001/0535 Single overhead camshafts [SOHC]
• CPC Class Codes: F01L 2800/00 Methods of operation using a variable valve timing mechanism
• CPC Class Codes: F02B 75/22 with cylinders in V, fan, or star arrangement
• CPC Class Codes: F02B 77/08 Safety, indicating or supervising devices thermal insulation F02B77/11; rendering engines inoperative or idling F02D17/04; dependent on lubricating conditions F01M1/22; dependent on cooling F01P11/14
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/0082 per groups or banks F02D41/0087 takes precedence
• CPC Class Codes: F02D 41/0085 Balancing of cylinder outputs, e.g. speed, torque or air-fuel ratio
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method is disclosed for balancing work output from cylinder banks of an engine having a common crankshaft and separate intake camshafts with cam phasers for each bank. The method includes sensing a crankshaft rotational characteristic, such as instantaneous rotational speed or acceleration, during the power strokes of pistons of predetermined comparable cylinders (or all cylinders) of each bank, computing average crankshaft rotational characteristics for the power strokes of the comparable cylinders of each bank, and adjusting the phasing of at least one of the intake camshafts to obtain equal averages of the sensed characteristics of the crankshaft during the power strokes of the respective banks.

Claims

1. A method for balancing work output from cylinder banks of an engine having a common crankshaft and separate intake camshafts with cam phasers for each bank;

the method comprising;

sensing a crankshaft rotational characteristic during the power strokes of pistons of predetermined comparable cylinders of each bank and computing average crankshaft rotational characteristics for the power strokes of the comparable cylinders of each bank; and

adjusting the phasing of at least one of the intake camshafts to obtain equal averages of the sensed characteristics of the crankshaft during the power strokes of the respective banks.

2. A method as in claim 1 wherein the sensed rotational characteristic is crankshaft speed.

3. A method as in claim 1 wherein the sensed rotational characteristic is crankshaft acceleration.

4. A method as in claim 1 wherein the sensed characteristic is detected by using a crankshaft position sensor.

5. A method as in claim 1 wherein the predetermined comparable cylinders include all the cylinders of each cylinder bank.

6. A method as in claim 1 wherein the engine is operable with early intake valve closing.

7. A method as in claim 1 wherein the engine is operable with late intake valve closing.

8. A method as in claim 1 wherein the engine is a V-type engine.