Patent ID: 7896262

Claim:
A fuel injection valve, comprising: a valve guide with a valve seat placed on an inner surface of the valve guide and a nozzle hole from which fuel is injected; a valve member movable along an axial direction of the valve guide to be seated on the valve seat of the valve guide and to leave the valve seat, the valve member seated on the valve seat closing the nozzle hole of the valve guide, the valve member opening the nozzle hole when leaving the valve seat; and a covering layer disposed on a surface of the valve guide around an outlet opening of the nozzle hole, wherein the covering layer has a hydrophilic property higher than that of the surface of the valve guide, the covering layer is made of boron nitride in a hexagonal crystal system, and the covering layer forms a film of water thereon such that residues of the fuel residues float on the water film.