Clean shutdown for internal combustion engine with variable valve timing

U.S. Patent Number: 6474291

Abstract: A four-stroke internal combustion engine is disclosed wherein fuel and exhaust vapors are purged from the manifolds and each cylinder when the engine is shut down to minimize emissions on subsequent startup. The engine includes a cylinder, a reciprocating piston within the cylinder, and a cylinder head. An exhaust port with an exhaust valve communicates with the cylinder and an exhaust manifold with an emissions control device. An intake port with an intake valve communicates with the cylinder. Upon engine shutdown, a controller sends signals to a variable valve timing system for opening the exhaust valve when the piston is in upward motion, later closing the exhaust valve when the piston is in upward motion, opening the intake valve when the piston is in downward motion, later closing the intake valve when the piston is in downward motion, and opening the exhaust valve when the piston is in upward motion.

Inventors: Collins; Brett D. (Ypsilanti, MI), DeLaSalle; Stephen (Saline, MI)

Assignee: Visteon Global Technologies, Inc. (Dearborn, MI)

Application Number: 09/740,593

Issued: 2002-11-05

Expired: 2006-11-05

Classes: 123/198DB ; 123/90.15; 701/112

Field of search: 123/90.15,481,19DB,198D,198F 701/112

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