Combustion system for direct injection diesel engines

A combustion system for direct injection diesel engines, comprising:

• a deep dish combustion chamber of a small opening ratio;
• a fuel injection nozzle disposed so as to be opposed to said deep dish combustion chamber;
• a first number of upper nozzle holes, having a first direction, forming an upper row of nozzle holes provided in said fuel injection nozzle;
• and
• a second number of lower nozzle holes, having a second direction, forming a lower row of nozzle holes provided in said fuel injection nozzle,
• wherein said first direction of said upper nozzle holes is set so that fuel injected from said upper nozzle holes impinges upon a bottom of said combustion chamber,
• wherein said second direction of said lower nozzle holes is set so that fuel injected from said lower nozzle holes impinges upon a bottom of said combustion chamber,
• wherein a ratio of a first fuel spay travel from said upper nozzle holes to a diameter of each of said upper nozzle holes is set to 150-250,
• wherein a ratio of a second fuel spray travel from said lower nozzle holes to a diameter of each of said lower nozzle holes is set to 100-180,
• wherein a ratio of a total area of all lower nozzle holes to that of all of said upper and lower nozzle holes is set to 0.25-0.35, and
• wherein said first number of upper nozzle holes is set twice as large as said second number of lower nozzle holes.