Combustion chamber in a diesel engine

A combustion chamber in a diesel engine, characterized in that the combustion chamber is defined in a top surface of a piston, an inlet in said top surface for communication with an upper end of the combustion chamber, a plurality of recesses in a surrounding side surface of the combustion chamber, and fuel nozzle means having injection ports for injecting atomized streams of fuel toward different wall portions of the combustion chamber such as deep portions of the recesses, shallow portions of the recesses, and portions free of the recesses, said fuel nozzle means including a number of said injection ports which is different from the number of said recesses by one.

A combustion chamber in a diesel engine, characterized in that the combustion chamber is defined in a top surface of a piston, an inlet in said top surface for communication with an upper end of the combustion chamber, a flow restriction at said inlet, a plurality of recesses in a surrounding side surface of the combustion chamber, and fuel nozzle means having injection ports for injecting atomized streams of fuel toward different wall portions of the combustion chamber such as deep portions of the recesses, shallow portions of the recesses, and portions free of the recesses, said top surface of the piston having at least one valve clearance space defined therein for accommodating an exhaust valve therein, said valve clearance space creating a stepped portion with said top surface, said stepped portion intersecting said restriction so that said clearance space communicates with said inlet, said stepped portion intersecting said restriction at a pair of angularly spaced points which are aligned with areas in said surrounding side surface which are either free of said recesses or intersect said recesses adjacent the edges thereof where said recesses have only shallow portions.

A combustion chamber in a diesel engine, characterized in that the combustion chamber is defined in a top surface of a piston, an inlet in said top surface for communication with an upper end of the combustion chamber, a flow restriction at said inlet, a plurality of recesses in a surrounding side surface of the combustion chamber, and fuel nozzle means having injection ports for injecting atomized streams of fuel toward different wall portions of the combustion chamber such as deep portions of the recesses, shallow portions of the recesses, and portions free of the recesses, said restriction being formed substantially as an annular flange which projects radially inwardly with respect to the surrounding side surface of the combustion chamber throughout the full annular extent thereof so as to define said inlet of smaller diameter than said surrounding side surface, said flange defining on the underside thereof an inner annular wall surface which slopes outwardly and downwardly at an angle of substantiall 45.degree. with respect to said top surface, said inner wall surface merging smoothly with said surrounding side surface, and said fuel nozzle means causing said atomized streams of fuel to be injected against said inner wall surface.

In a piston for a diesel engine, the piston having a combustion chamber formed in the upper end thereof, the piston having a top surface provided with an inlet opening formed therein for communication with an upper end of the combustion chamber, the combustion chamber including a generally cylindrical cavity having a surrounding and generally cylindrical sidewall, and fuel nozzle means having a plurality of injection ports for injecting a plurality of atomized streams of fuel into the combustion chamber in angularly spaced relationship therearound, comprising the improvement wherein the combustion chamber includes a plurality of recesses which are formed in and project radially outwardly from said surrounding sidewall, said recesses being angularly spaced apart and each extending over a substantial angular extent with respect to said sidewall, said sidewall having angularly extending regions which are located between adjacent pairs of said recesses, and the angular spacing between the plurality of fuel streams being different from the angular spacing between the plurality of recesses so that the individual fuel streams are directed toward different wall portions on the recesses and surrounding sidewall to provide different combustion characteristics.