Cylinder Charge Temperature Control for an Internal Combustion Engine

An engine system for a vehicle, comprising:

• a first cylinder including a piston moveably arranged within the first cylinder configured to initiate combustion within the first cylinder by auto-ignition;
• a second cylinder including a spark plug;
• an intake manifold communicating with the first and second cylinders;
• an exhaust manifold communicating with the first and second cylinders;
• a control system configured to operate the first cylinder to repetitively perform auto-ignition by compressing a first mixture of gases received from the intake manifold and fuel within the first cylinder with the piston;
• and
• wherein the control system is further configured to, during said operation of the first cylinder, operate the second cylinder to repetitively entrain gases from the intake manifold via an intake manifold valve, ignite a second mixture including said entrained gases and fuel with a spark performed by the spark plug, and reintroduce at least a portion of said combusted second mixture into the intake manifold via the intake manifold valve, and wherein the control system is configured to adjust a timing of said intake manifold valve of the second cylinder to vary a timing of auto-ignition within the first cylinder.

A method of operating an engine including at least a first cylinder and a second cylinder, the method comprising:

• operating the first cylinder of the engine to provide a net flow of gases from an intake manifold to an exhaust manifold for each cycle of the first cylinder while repetitively combusting a homogeneous mixture including said gases and directly injected fuel in said first cylinder by auto-ignition;
• and
• during said operation of the first cylinder, repetitively operating an intake manifold valve of the second cylinder to admit gases from the intake manifold into the second cylinder, injecting fuel directly into the second cylinder to form a mixture of said admitted gases and fuel in said second cylinder, and exhausting said combusted mixture from the second cylinder into the intake manifold via the intake manifold valve while holding an exhaust manifold valve of the second cylinder closed;
• wherein said homogeneous mixture includes at least a portion of said combusted mixture exhausted from the second cylinder.

A method of operating an engine including a plurality of cylinders forming a first cylinder group and a second cylinder group, said first and second cylinder groups each including at least one cylinder, the method comprising:

• operating the first cylinder group of the engine to provide a net flow of gases from an intake manifold to an exhaust manifold while repetitively combusting a mixture including at least said gases and directly injected fuel in each cylinder of said first cylinder group;
• and
• during said operation of the first cylinder group, repetitively trapping gases from the intake manifold within each cylinder of the second cylinder group for a period by opening and closing at least an electromagnetic intake manifold valve before exhausting the trapped gases into the intake manifold;
• and
• varying a number of cylinders of said second cylinder group responsive to operating conditions.