Electromagnetic metering valve for a fuel injector
AssigneeElasis Sistema Ricerca Fiat Nel Mezzogiorno Societa Consortile per Azioni
InventorMario Ricco
Life of this patent
Estimating the term…
Abstract
A metering valve presenting a shutter for a discharge conduit, and an eleomagnet in turn presenting a fixed core and a disk-shaped armature detached from and sliding on the stem by means of a sleeve. The stem is guided by a bush, presents a flange movable inside a swirl chamber with a velocity damping effect, and is fitted, prior to assembling the armature and the electromagnet, by means of a ring nut, which presses a flange, forming one piece with the bush, against the body of the valve via the interposition of calibrated washers so selected as to define the travel of the stem.
Claims7
An electromagnetic metering valve for a fuel injector, comprising a control chamber (61) supplied with fuel under pressure, a discharge conduit (63) for discharging the fuel of said control chamber (61), a shutter (67) for said discharge conduit (63), a discharge chamber (60) communicating with said conduit (63), and an electromagnet (42) presenting a fixed magnetic core (46) and a movable armature (43) for controlling said shutter (67);
- said armature (43) being associated with a stem (69) provided with a first flange (88) for controlling said shutter (67), a first spring (78) normally pushing said stem (69) with a predetermined force to keep said shutter (67) in a position closing said discharge conduit (63);
- said stem (69) being guided by stationary guide and travel arresting means (82), wherein said first flange (88) is provided with a first surface (S), and said guide and travel arresting means (82) comprise a bush (83) slidably guiding said stem (69), and a second flange (84) fitted to a body (56) of the valve;
- said second flange (84) being provided with a second surface (Y) adapted to be engaged by the first surface (S) to arrest said first flange (88), said second flange (84) defining a swirl chamber (89) located between said discharge conduit (63) and said discharge chamber (60) and housing said first flange (88), wherein an opening movement of said first flange (88) is dampened by rapid compression and expulsion of the fuel in said swirl chamber (89) between said first surface (S) and said second surface (Y).
Dependencies are inferred from the claim text.