Patent ID: 8413913
Filing Date: 2013-04-09
Classification: F02M

Abstract:
1. A unit injector for injecting liquid fuel directly into an engine cylinder, the unit injector comprising: a main body circumferentially surrounding an imaginary longitudinal axis; a fuel inlet port in the main body through which fuel can enter the fuel injector; an injection mechanism; a nozzle comprising orifices through which the injection mechanism can inject fuel out of the unit injector; and a boundary edge filter comprising a first endless annular internal space that is open to the fuel inlet port, a second endless annular internal space that is spaced axially of the first endless annular internal space and through which fuel is supplied to the injection mechanism, and a series of circumferentially spaced apart, axially extending channels through which fuel can pass from the first endless annular internal space to the second endless annular internal space; the total cross sectional area for fuel flow through the channels being large enough to meet injection demand throughout an engine's fueling range, while the cross sectional area for fuel flow through an individual channel is small enough to prevent particulate material above a certain size in the first endless annular internal space from passing into the second endless annular internal space.