Reciprocating engine with cylindrical combustion chamber

Claim 1

A reciprocating internal combustion engine comprising an engine block defining a cylinder, a piston moving reciprocatingly in said cylinder, a cylinder head mounted in association with said engine block, intake and exhaust valves, said cylinder, said piston and said cylinder head jointly with a valve plate of the intake valve defining a combustion chamber at the top dead center position of said piston, said combustion chamber lying substantially entirely within said cylinder head and having the shape of a right circular cylinder one end face of which is defined by a disc of said intake valve of the engine, said piston being provided with a cap portion defining a projection, said projection having a substantially flat surface defining an end face of said combustion chamber and including a recess which defines a guide channel having a light curvature substantially in the direction of rotary air flow in the combustion chamber beginning at or near a point of fuel flow from the injection nozzle with relatively great depth and then becomes gradually more shallow until it merges with the top of the projection at its far end substantially at the opposite side of the combustion chamber, said projection substantially constituting the other end face of said combustion chamber at top dead center of said piston, the interior of said projection defining a void which serves as a thermal barrier, and a fuel injection nozzle disposed in a side wall of said combustion chamber and so oriented as to emit a jet of fuel substantially perpendicular to the cylindrical axis of said combustion chamber along said guide channel.