FUEL INJECTION NOZZLE

PROBLEM TO BE SOLVED: To provide a fuel injection nozzle 1 capable of promoting atomization of injection fuel without increasing both injection period and injection pressure. SOLUTION: A needle tip part 4 of the fuel injection nozzle 1 is provided with a flow disturbing means comprised of an annuarly formed recessed part 16 in a circumferential direction and two or more grooves 17 formed in an upstream side from the recessed part 16 in the circumferential direction. Intervals between the grooves 17 become narrower toward an opening part to the recessed part 16 in the circumferential direction. Due to this, flows of fuel are disturbed when the fuel passes through a second fuel passage 15, leading to collision between the flows and generation and collapse of air bubbles by cavitation. Therefore, since turbulent flow energy of fuel inside a suck chamber 9 is increased, fuel is injected along with strong turbulence. As a result, fuel is more atomized compared to conventional cases, and a spray angle is also more expanded compared to conventional cases. COPYRIGHT: (C)2005,JPO&NCIPI