Starting a compression ignition free piston internal combustion engine having multiple cylinders
AssigneeFord Global Technologies, LLC
InventorCliff Carlson
Life of this patent
Estimating the term…
Abstract
A method for starting a free piston, internal combustion engine includes supplying an air charge to a space in a combustion cylinder, and reciprocating the piston in the cylinder so that the maximum pressure of the air charge in the space cyclically increases. Air and fuel are cyclically admitting to the cylinder to produce an air-fuel mixture, and spark ignition is used to produce cyclic combustion of the air-fuel mixture. The air-fuel ratio of the mixture is increasing when a maximum pressure in the cylinder occurs within a predetermined period following a TDC position of the piston. Spark ignition is discontinued, and cyclic compression ignition (HCCI) of the air-fuel mixture occurs.
Claims24
A method for starting a free piston internal combustion engine that includes a first pair of mutually connected pistons, a second pair of mutually connected pistons, a first piston of each pair moving in a first cylinder, a second piston of each pair moving in a second cylinder, the method comprising the steps of:
- supplying an air charge in a space located between the pistons in each cylinder;
- closing the spaces against passage of fluid while reciprocating the pistons in the cylinders and cyclically increasing a maximum pressure of the air charges in the spaces;
- cyclically admitting air and fuel to the cylinders to produce an air-fuel mixture;
- using spark ignition to produce cyclic combustion of the air-fuel mixture;
- reducing an air-fuel ratio of the mixture when a maximum pressure in the cylinder occurs within a predetermined period following movement of a piston pair past a TDC position;
- discontinuing spark ignition;
- and
- producing cyclic combustion ignition of the air-fuel mixture.
A method for starting a free piston internal combustion engine that includes a cylinder, a piston located in the cylinder for movement therein, the method comprising the steps of:
- supplying an air charge to a space in the cylinder;
- closing the space against passage of fluid while reciprocating the piston in the cylinder and cyclically increasing a maximum pressure of the air charge in the space;
- cyclically admitting air and fuel to the cylinder to produce an air-fuel mixture in the cylinder;
- using spark ignition to produce cyclic combustion of the air-fuel mixture;
- reducing an air-fuel ratio of the mixture when a maximum pressure in the cylinder occurs within a predetermined period following movement of a piston past a TDC position;
- discontinuing spark ignition;
- and
- producing cyclic combustion ignition of the air-fuel mixture.
Dependencies are inferred from the claim text.