Abstract: A direct fuel injection internal combustion engine comprises an auxiliary piston in an auxiliary cylinder for modulating sharp pressure rises in the combustion chamber. The main piston has a cavity into which injected fuel is directed. The fuel injection stream and the output from the auxiliary cylinder intersect.

Abstract: An inlet port for an internal combustion engine having an inlet hole opened on an end face of a cylinder chamber at an off-center position, the inlet hole being provided with an inlet valve and connected to an inlet passage.

Abstract: An injection nozzle comprises: a nozzle body arranged in a case in such a manner that the nozzle body is movable along the axis thereof; an injection outlet for jetting fuel when said nozzle body is moved along the axis to open the injection outlet; at least one fluid jetting outlet which is communicated through a fluid supply passage to a fluid supply device, for jetting fluid towards the fuel thus jetted; and a control unit having at least one stationary opening and a movable opening to supply fluid to the fluid jetting outlet when the stationary and movable openings are aligned with each other, to thereby control fluid jetted from the fluid jetting outlet. The fluid jetted from the fluid jetting outlet is applied to the fuel jetted by the injection outlet, to cause the kinetic energy of the fluid to shear the fuel and to thereby improve the atomization of fuel, and to control a fuel scattering direction and a fuel spray pattern.

Abstract: An inlet port for an internal combustion engine has an inlet port opened on an end face of a cylinder chamber at an off-center position, and the inlet hole is provided with an inlet valve and connected to an inlet passage. The inlet passage comprises a swirl generating section and an introducing section, and width between the peripheral surface of the valve stem of the inlet valve and the wall surface of the swirl generating section is made larger at the outside part on the wall side of the cylinder chamber than at the inside part on the center side of the cylinder chamber. The introducing section is connected to the outside part of the swirl generating section. In the plane intersecting perpendicularly to the center line of the introducing section within the parallel plane to the opening face of the inlet hole, the width of the outside part of the swirl generating section is set between 1.1 times and 2.8 times of the width of the inside part.