Engine and ignition assembly with two pistons

A piston engine with multiple fuel injections, comprising:

• a cylinder liner and a cylinder wall;
• the cylinder liner encloses a chamber therein;
• a main piston configured to fit sealingly inside the cylinder liner and move up and down along the centerline of the cylinder liner;
• an auxiliary piston is configured to fit sealingly inside the cylinder liner and move up and down along the centerline of the cylinder liner;
• wherein the main piston and the auxiliary piston move at different frequencies, the main piston and the auxiliary piston move at different stroke distances, the lowermost position of the auxiliary piston lower face is below the uppermost position of the main piston upper face;
• the space between the auxiliary piston and the main piston within the cylinder liner defines a combustion chamber;
• the said frequencies and the stroke distances of the auxiliary piston and the main piston are coordinated to keep the combustion chamber volume nearly constant from crank angle 0° CA to 30° CA;
• an ignition assembly is mounted sealingly on the cylinder wall, the ignition assembly connects to the combustion chamber via a cut-out passage on the cylinder liner;
• wherein the uppermost position of the cut-out passage is at or aligned with the uppermost position of the auxiliary piston lower face in combustion stroke, the lowermost position of the cut-out passage is at or aligned with the uppermost position of the main piston upper face,
• wherein the auxiliary piston has a by-pass passage, the by-pass passage connects the ignition assembly to the combustion chamber when the auxiliary piston moves down below the uppermost position of the main piston and blocks the cut-out passage;
• fuel is injected multiple times in each cycle from crank angle −30° CA to 30° CA.

A piston engine with fuel-water mixture, comprising:

• a cylinder liner and a cylinder wall, the cylinder liner encloses a chamber therein;
• a main piston configured to fit sealingly inside the cylinder liner and move up and down along the centerline of the cylinder liner therewithin;
• an auxiliary piston is configured to fit sealingly inside the cylinder liner and move up and down along the centerline of the cylinder liner;
• the lowermost position of the auxiliary piston lower face is below the uppermost position of the main piston upper face, the space between the auxiliary piston and the main piston within the cylinder liner defines a combustion chamber;
• wherein the main piston and the auxiliary piston move at different frequencies, the main piston and the auxiliary piston move at different stroke distances;
• the said frequencies and the stroke distances of the auxiliary piston and the main piston are coordinated to keep the combustion chamber volume nearly constant from crank angle 0° CA to 30° CA;
• an ignition assembly is mounted sealingly on the cylinder wall, the ignition assembly connects to the combustion chamber via a cut-out passage on the cylinder liner,
• wherein the uppermost position of the cut-out passage is at or aligned with the uppermost position of the auxiliary piston lower face in combustion stroke, the lowermost position of the cut-out passage is at or aligned with the uppermost position of the main piston upper face;
• wherein the auxiliary piston has a by-pass passage, the by-pass passage connects the ignition assembly to the combustion chamber when the auxiliary piston moves down below the uppermost position of the main piston and blocks the cut-out passage;
• water or fuel-water mixture is injected from crank angle 0° CA to 30° CA to reduce temperature stress of the cylinder.