Patent ID: 7438054
Filing Date: 2008-10-21
Classification: F02M

Abstract:
1. A fuel injector comprising: an injection valve provided with a mobile needle to regulate the fuel flow; an actuator adapted to shift the needle between a closed position and an open position of the injection valve; an injection nozzle displaying a plurality of through injection holes formed from an injection chamber arranged downstream of injection valve; a supporting body having a tubular shape and displaying a feeding channel; a sealing body provided with a valve seat of the injection valve and comprising a disc-shaped capping element, which lowerly and fluid-tightly closes the feeding channel and is crossed by the injection nozzle, and a guiding element, which rises from the capping element, has a tubular shape, and accommodates the needle therein; an external fuel guiding channel defined between the feeding channel and the guiding element which displays an external diameter smaller than the internal diameter of the feeding channel; a number of through feeding holes made in the lower part of the guiding element and leading towards the valve seat; and a shutter head having an essentially spherical adjustment zone, which is integral with the needle, externally engages the guiding element and is adapted to fluid-tightly rest against the valve seat; wherein the fuel injector is characterised in that the feeding holes are dimensioned so that the intensity of a first autoclave force (F wherein the feeding holes are dimensioned so as to cause, when the fuel flows through the feeding holes themselves towards the injection nozzle, a localised pressure drop (ΔP), the intensity of which is provided by the following formula: ΔP P A A