Fuel injection system

Abstract

A fuel injection system capable of improving the degree of atomization and the combustibility of a fuel, including a fuel swirler, a valve seat having a fuel injection port, an annular fuel swirl chamber formed between the fuel swirler and a valve seat and communicating with plural swirl grooves and a fuel injection port, and a valve body adapted to be moved forward and backward in the interior of the fuel swirler in the axial direction thereof and thereby disengaged from and engaged with the valve seat to open and close a communication passage between the fuel swirl chamber and fuel injection port. Let S1, S2 and S3 equal a minimum cross-sectional area of an opening between the valve body and valve seat in the condition in which the communication passage is fully opened, an area of a cross section of the fuel injection port which is perpendicular to the axis thereof, and an average cross-sectional area of a fuel flow in the fuel injection port, respectively. A stroke amount of the valve body is set so that a minimum cross-sectional area of the mentioned opening satisfies the following expression: S3<S1<S2.

Dependencies are inferred from the claim text.