Fuel injection nozzle for internal combustion engines

摘要

Fuel injection nozzle for pilot injection and main injection with an inwardly opening valve needle (18), the closing spring (38) of which is supported on a valve seat (56) by way of a deflection piston (50, 60) guided in a cylinder bore (24, 24a), which valve seat surrounds the opening of a fuel duct (20, 54, 26) into the cylinder bore (24, 24a). At the end of a pilot injection phase the deflection piston (50, 60) is displaced by the rising fuel pressure, fuel flowing into the cylinder bore (24, 24a). As a result, the rise in the fuel pressure experiences a temporary interruption, producing a marked transition between pilot and main injection. The closing spring (38) is supported on the valve seat (56) by way of a closing body (57, 60), which is of convex spherical design at least on its side facing the valve seat (56). As a result, the manufacturing tolerances on the nozzle holder (16, 16a) and possibly on the deflection piston (50) can be increased. <IMAGE>