Patent ID: 7096848

Claim:
A direct injection diesel engine comprising: a combustion chamber which is provided in a top face of a piston and which opens toward a cylinder head; and a fuel injection nozzle provided in the cylinder head for injecting fuel toward said combustion chamber, wherein said combustion chamber comprises: a first volume, open toward the cylinder head, which has a circular periphery at said top face and is recessed from said top face toward a pin boss, and a second volume which is provided substantially at a center of the first volume and which is further recessed toward said pin boss than said first volume; wherein the fuel injection from said fuel injection nozzle is continuously performed first into said second volume and then into said first volume in association with movement of said piston; and wherein during at least a portion of the engine operation, an injection period beginning at a start of the fuel injection and ending when the fuel injection reaches a border section between said first volume and said second volume is set to be in a range of 40% to 70% of a total fuel injection period by controlling a timing for start of the fuel injection in accordance with at least one of engine speed and engine load.