Gm Global Technolgoy Operations, Inc.

Edward G Groff

Edward D Klomp

Paul E Reinke

Roger B Krieger

Ramachandra Diwakar

Keith Meintjes

Rodney Brewer Rask

Arun S Solomon

Michael J Gorman

Donald Terry French

Robert A Bolton

James G Solomon

Stephen F De Nagel

Ronald J Cantrell

Paul M Heck

A powertrain control method applied to a lean burn engine coupled to a continuously variable transmission for minimizing engine out emissions selects one or more control parameters from a plurality of parameters that may be precisely controlled to provide for acceptable powertrain control with minimized emissions. Lean burn engine operation is maintained under low brake mean effective pressure conditions by modulating powertrain output power through transmission drive ratio variation. Fuel and air per cylinder may further be varied with the drive ratio when low emissions can be provided with minimum sacrifice to fuel economy. Lean burn operation is suspended under high brake mean effective pressure conditions by driving air/fuel ratio toward the stoichiometric ratio to exploit the efficiency of an included three-way catalytic treatment device while lowering engine speed to stabilize combustion.

Integrated control of a lean burn engine and a continuously variable

A two-stroke cycle spark ignition engine having cylinder fuel injection is provided with a combustion chamber featuring a delta shaped bowl or cavity that is configured and positioned in the cylinder head to improve scavenging of the combustion chamber near the injector while maintaining adequate squish flow for improved charge mixing and combustion.

Two-stage cycle engine and combustion chamber

An exhaust port timing valve for a two cycle engine has a sealing shroud preferably made as a flexible sheet that is urged by gas pressure into sealing contact with a slot and/or sealing edges of an associated exhaust port or shroud to allow low friction valve adjustment while limiting gas leakage past the valve unaffected by close tolerances and temperature changes. Springs and/or seals can alternatively be used with flexible or non-flexible shrouds to improve sealing.

Sealing shroud port timing valve for two cycle engine

A port scavenged two cycle engine with a separate source of pressurized air has a valve between each port and the air supply to provide a high blowdown pulsing scavenging flow to the cylinders similar to that of a crankcase scavenged engine. Various arrangements with additional features are disclosed.

Two cycle engine with valved pressure scavenging

Combinations of split and valved exhaust ports are provided in a ported two cycle engine with divided emission control system to provide better control of the division of exhaust gas flow to the two converters.

Two cycle engine catalytic emission control

A direct injection internal combustion engine of the diesel or spark ignition type is provided with a combustion bowl recess in the head end of the piston having both a polygonal lip and a polygonal bowl with upwardly and inwardly curving reentrant sides to provide high turbulence for fuel air mixing during an extended portion of the piston compression stroke and improved combustion of the air/fuel mixture.

Engine and high turbulence piston therefor

In an engine having direct fuel injection or injection at individual intake ports, the fuel injectors are of the positive displacement type and are equipped with plunger displacement sensors to yield a displacement signal representing the quantity of fuel injected. This signal is used as feedback to a closed loop PID control which compares the injected quantity to a demand quantity to determine an error and calculates a control pulsewidth which reduces the error eventually to zero. An open loop injector calibration of pulsewidth versus approximate fuel quantity is used as a base pulsewidth to which the closed loop adds a correction value.

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Troy, MI, United States of America

Edward G Groff