Method for operation of a free piston engine

A method of operating a free-piston engine apparatus comprising the steps of:

• providing a free-piston engine apparatus with a combustion chamber body and a compression section;
• providing in said engine a piston element including a piston head in said combustion chamber body, and exhaust passage in said combustion chamber body, and a compression chamber piston in said compression section, said piston element being reciprocally movable in said engine between a bottom dead center position BDC and a top dead center position TDC, said exhaust passage being located between said bottom dead center position BDC and said top dead center position TDC, said piston element being movable to close said exhaust passage;
• providing a control valve in flow communication with said compression section;
• providing a fuel injection device in said engine, said fuel injecting device selectively injecting atomized fuel into said combustion chamber body;
• providing a controller in communication with said control valve and said fuel injection device, said controller actuating said control valve and said fuel injection device;
• actuating said control valve prior to said fuel injection device with the controller and passing fluid to said compression section, said fluid moving said piston element from the bottom dead center BDC position to the top dead center position;
• and
• actuating said fuel injection device immediately after a closing of the exhaust aperture with the engine piston element and continuously during movement of the engine piston element through a stroke "S" substantially to the top dead center position TDC.