PISTON FOR DIRECT INJECTION ENGINE AND DIRECT INJECTION ENGINE

摘要

PROBLEM TO BE SOLVED: To attain reduction of emission and improvement in fuel consumption, by promoting diffusion of vaporization fuel vaporized after adhering to a wall surface of a piston. SOLUTION: In a piston 3 of a direct injection diesel engine, six air chambers 17 having a jet nozzle 19 are formed in the vicinity of a position (position hit by a jet stream as shown by chain line) hit by fuel injected from six nozzles of an injector 8 on an internal peripheral surface 16a of a recessed part (cavity) 16. A communication path 18 connecting the jet nozzle 19 and the air chamber 17 is directed to a position hit by fuel and extended in a tangential direction of the internal peripheral surface 16a. Air blown out from the jet nozzle 19 flows along the internal peripheral surface 16a when the piston 3 is lowered down beyond the top dead center, so as to generate an air flow in a position hit by fuel.