FUEL ELECTRO-INJECTOR ATOMIZER FOR A FUEL INJECTION SYSTEM FOR AN INTERNAL COMBUSTION ENGINE

摘要

An atomizer (10) of a fuel electro-injector (1) for a fuel injection system for an internal combustion engine having a passage (13) that extends along a longitudinal axis (5) and includes a guide hole (46); the atomizer (10) has a sealing seat (21) defined by a chamfer or a fillet, which joins an cylindrical surface (41) inside the passage (13) and an external front surface (40); the atomizer (10) is equipped with a needle (27) having a first slider portion (25) coupled in an axially sliding manner to the guide hole (46), so as to define a dynamic seal and be axially movable under the thrust of an electro-actuator (32) from a closed position, in which a head (20) of the needle (27) is coupled to the sealing seat (21) to close the outlet and define a static seal; the diameter (D) of the guide hole (46) is between 2.5 e 3.3 mm, while the difference between the average diameter of the sealing seat (21) and the diameter of the guide hole (46) is such as to generate a maximum axial imbalance of 50 N, directed in the opening direction, due to the effect of the fuel pressure around the needle (27) when the latter is positioned in the closed position.