| 摘要 |
An injection nozzle for an internal combustion engine includes a nozzle body provided with a bore within which a valve needle is movable along a primary valve needle axis (A-A), the valve needle being engageable with a valve seating defined by the bore to control fuel delivery through an injection nozzle outlet. The nozzle includes a first valve region, a second valve region and a seating region located between the first and second valve regions which seats against the valve seating when the nozzle is in a non-injecting state. A diffusion volume is defined between the valve needle and the bore downstream of the valve seating and into which fuel flows once it has flowed past the valve seating when the valve needle is lifted from the valve seating into an injecting state. The valve needle is provided with a diffusion region of part-spheroidal or part-spherical form to define a smooth transition for a diverging fuel flow into the diffusion volume, thereby to minimise turbulence within the diffusion volume.
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