System and method for controlling engine operation

• US 20060011159A1
• Filed: 07/13/2005
• Published: 01/19/2006
• Est. Priority Date: 05/14/2002
• Status: Abandoned Application

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Pierpont, David Andrew, Weber, James Richard, Leman, Scott Alan, Bloms, Jason Kenneth, Faletti, James J.
• Application Number:
  US11/179,808
• Publication Number:
  US 20060011159A1
• Time in Patent Office: Days
• US Class Current: 123/90.120
• CPC Class Codes: F01L 13/06 for braking
• CPC Class Codes: F01L 2001/34446 Fluid accumulators for the feeding circuit
• CPC Class Codes: F01L 2013/0089 with means for delaying valve closing
• CPC Class Codes: F01L 9/10 by fluid means, e.g. hydraulic
• CPC Class Codes: F02B 2275/32 Miller cycle
• CPC Class Codes: F02D 13/0269 Controlling the valves to perform a Miller-Atkinson cycle
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A method of controlling an engine is provided. At least one operating parameter of the engine is sensed. The engine is operated in a first mode in response to the sensed operating parameter being at one of a predetermined first set of conditions. In the first mode, a cam assembly moves an intake valve from a first position when a piston starts an intake stroke and the cam assembly returns the intake valve to the first position when the piston completes the intake stroke. The engine is operated in a second mode in response to the sensed operating parameter being at one of a predetermined second set of conditions. In the second mode, the cam assembly moves the intake valve from the first position when the piston starts an intake stroke and an actuator prevents the intake valve from returning to the first position in response to the cam assembly.

Claims

1. A method of operating an engine having a cylinder, an intake valve associated with the cylinder and moveable between a first position where the intake valve prevents a flow of fluid relative to the cylinder and a second position where the intake valve allows a flow of fluid relative to the cylinder, a cam assembly connected to the intake valve to move the intake valve between the first and second positions, and an actuator connected to the intake valve, comprising:

sensing at least one operating parameter of the engine;

operating the engine in a first mode wherein the cam assembly begins to move the intake valve from the first position toward the second position when the piston is at or near a top dead center position of an intake stroke and wherein the cam assembly returns the intake valve to the first position when the piston is at or near a bottom dead center position of the intake stroke, the engine operating in the first mode in response to the sensed operating parameter being at one of a predetermined first set of conditions; and

operating the engine in a second mode wherein the cam assembly begins to move the intake valve from the first position toward the second position when the piston is at or near a top dead center position of an intake stroke and wherein the actuator prevents the intake valve from returning to the first position in response to the cam assembly, the engine operating in the second mode in response to the sensed operating parameter being one of a predetermined second set of conditions.

2-29. -29. (canceled)