Fukushitsushikikikannonenshoshitsu

摘要

PURPOSE:To prevent incomplete combustion when injection timing is controlled to be delayed by making the inclined angle of the auxiliary chamber-side ridge of a section of an auxiliary chamber injection port cut by the plane including the center lines of an auxiliary combustion chamber and a cylinder, greater than the same angle of the cylinder-side ridge and providing a projection at the lower portion of the auxiliary chamber-side ridge. CONSTITUTION:The auxiliary chamber-side ridge of a section of an auxiliary chamber injection port is inclined at an angle greater than that of the cylinder-side ridge, and a projection is provided at the lower portion of the auxiliary chamber-side ridge. When fuel injection timing is delayed to reduce NOx and ignition is carried out in an auxiliary combustion chamber 2 during the downward stroke of a piston 7, flow of gas from the auxiliary combustion chamber 2 into a main combustion chamber 1 is restricted, because the opening area of the auxiliary chamber injection port 3 facing to the auxiliary combustion chamber is small and the angle thetaL is small. Therefore, the combustion in the auxiliary chamber 2 is expedited and stabilized. Thereafter, increase of pressure in the auxiliary combustion chamber 2 causes flow of gas into the main combustion chamber 1, and as the angles thetaR' and thetaL are small, penetration of injected gas toward the center of the cylinder is improved, and forming of mixture of air with unburned fuel in the main combustion chamber 1 and combustion of the same are promoted. As the result, reduction of NOx, HC and smoke can be achieved as well as reduction of noise.