| 摘要 |
PROBLEM TO BE SOLVED: To improve ignition stability in the case of small amount of fuel injection while using advantage of multi-ignition type fuel injection valve allowing realization of good combustion to a relatively high load side, and to prevent increase of smoke while securing sufficient output in a high-speed and high load region, in a spark ignition type direct injection engine 1 in which fuel atomization is guided around an ignition plug 16 by a wall surface of a cavity 5a disposed in a crown surface of a piston 5 to be laminated. SOLUTION: Seven nozzle holes 52 are elliptically arranged at the tip 54a of an injector 18 disposed every cylinder 2 of the engine 1. They are set so that the longitudinal direction of the ellipse V formed by interconnecting the nozzle holes 52 is a cylinder column direction of the engine 1. The fuel atomization S integrally formed by the fuels injected from respective nozzle holes 52 has a relation thatα=approximately 25°to 35°,β=approximately 35°to 45°, andβ>α+approximately 10°, whereαis expansion angle in the direction of the cylinder center line Z, andβis expansion angle in the cylinder column direction. COPYRIGHT: (C)2003,JPO
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