| 摘要 |
PURPOSE:To prevent the occurence of an incomplete combustion that happens when a reduction in NOx is aimed at in delaying the fuel injection timing, by tilting a part around at least the opening part of a antechamber nozzle hole of the end face at the antechamber of a partition wall. CONSTITUTION:An antechamber nozzle hole 2 pierces a partition wall between an antechamber 1 and a main chamber 3, and the antechamber 1 is of semispheric type in structure at its upper part, while a bottom surface 1a of the end face at the antechamber side of the partition wall thickens the outward side of the partition wall and tilts it in addition. When the minimum angle between an axis center line of the antechamber nozzle hole 2 and the antechamber bottom surface 1a is set down to theta2, while another minimum angle between the axis center line of the antechamber nozzle hole 2 and the main chamber side end face is set down to theta1, the angle is formed into theta2<theta1 like that. With a tilt of the antechamber bottom surface 1a, fuel injection timing is delayed to some extent from the standpoint of reducing NOx whereby even if a piston 7 ignites inside the antechamber 1 during its descendent stroke, gas flowing from the antechamber 1 to the main chamber 3 is checked so that combustion inside the antechamber 1 is accelerated and stabilized in consequence. Afterward, with a pressure rise inside the antechamber 1, gas flows into the main chamber 3 and in addition, injection velocity is speedy so that the formation of a fuel-air mixture inside the main chamber 3 and the combustion both are accelerated. |
