US 12,378,910 B1
Systems and methods for extra-stroke engine cycle operation
John R. McDonald, Peoria, IL (US); and Derek A. Tanis, Peoria, IL (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Peoria, IL (US)
Filed on May 3, 2024, as Appl. No. 18/654,850.
Int. Cl. F02D 13/02 (2006.01); F02B 75/02 (2006.01); F02D 41/40 (2006.01); F02D 41/38 (2006.01)
CPC F02B 75/021 (2013.01) [F02D 13/0242 (2013.01); F02D 41/40 (2013.01); F02B 2075/027 (2013.01); F02D 2041/389 (2013.01); F02D 2400/02 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
operating an engine in an extra-stroke mode including:
an intake stroke, during which an intake valve of an engine cylinder included in the engine is opened to allow a mass of air to enter a combustion chamber of the engine cylinder;
a first compression stroke, immediately subsequent to the intake stroke, during which the mass of air within the combustion chamber is compressed;
a decompression stroke, immediately subsequent to the first compression stroke, during which the mass of air within the combustion chamber is decompressed and during which the mass of air within the combustion chamber is not combusted;
a second compression stroke, during which the mass of air within the combustion chamber is recompressed;
a power stroke, during which an air-fuel mixture including the mass of air and a mass of fuel within the combustion chamber is ignited; and
an exhaust stroke, immediately subsequent to the power stroke, during which an exhaust valve of the engine cylinder is opened to allow exhaust to exit the engine cylinder.