FUEL INJECTOR HAVING FLAT SEAT AND NEEDLE FUEL SEAL

摘要

89P7811/05???0488 89P7811 An electromagnetic fuel injector has a raised seat with which the needle tip coacts to open and close the injector as the injector is operated. The raised seat has an annular transverse seating surface surrounding a hole through the seat member. The hole through the seat member has a frusto-conically shaped surface immediately contiguous the annular seating surface, and the tip of the injector needle is conically shaped. The cone angle of the needle tip is greater than the cone angle of the frusto-conically shaped hole in the seat member, and the needle tip and the annular transverse surface of the seat are almost parallel so that the needle tip seats on the annular transverse surface of the seat at the rim of the frusto-conically shaped hole when the injector closes. The seat is softer than the needle so that the seal is initially good and becomes better as the injector is operated.