Abstract: This piston for a diesel engine includes: a bottom portion that has a deepest combustion chamber bottom in the combustion chamber; a circumferential protrusion that is provided around an entire circumference of a circumferential wall between the bottom portion and a top surface of the piston and protrudes toward an intersection (P0) of a center line of the piston and the top surface in a cross-sectional view that includes the center line; an inclination portion that inclines closer to the top surface toward an outer side in a radial direction from the circumferential protrusion; and a rising portion that rises from the inclination portion toward the top surface.

Abstract: This piston for a diesel engine includes: a bottom portion that has a deepest combustion chamber bottom in the combustion chamber; a circumferential protrusion that is provided around an entire circumference of a circumferential wall between the bottom portion and a top surface of the piston and protrudes toward an intersection (P0) of a center line of the piston and the top surface in a cross-sectional view that includes the center line; an inclination portion that inclines closer to the top surface toward an outer side in a radial direction from the circumferential protrusion; and a rising portion that rises from the inclination portion toward the top surface.

Abstract: An engine control system comprises a NOx catalyst selectively reducing NOx from exhaust gases, a reducing agent supply providing the reducing agent to an exhaust system and positioned upstream of the NOx catalyst, NOx sensors detecting an amount of NOx in exhaust gases emitted by an internal combustion engine, a fuel injection system injecting fuel to the internal combustion engine in a main injection mode or a pilot-and-main injection mode, and a control unit activating the fuel injection system in the pilot-and-main injection mode when a NOx purifying efficiency determined on the basis of data of emitted NOx is equal to or below a preset purifying efficiency.

Abstract: An engine control system comprises a NOx catalyst selectively reducing NOx from exhaust gases, a reducing agent supply providing the reducing agent to an exhaust system and positioned upstream of the NOx catalyst, NOx sensors detecting an amount of NOx in exhaust gases emitted by an internal combustion engine, a fuel injection system injecting fuel to the internal combustion engine in a main injection mode or a pilot-and-main injection mode, and a control unit activating the fuel injection system in the pilot-and-main injection mode when a NOx purifying efficiency determined on the basis of data of emitted NOx is equal to or below a preset purifying efficiency.