Patent ID: 8695899
Filing Date: 2014-04-15
Classification: F02M

Abstract:
1. A fuel injector comprising: a housing having a central longitudinal axis, a first cavity, a fluid inlet portion, and a fluid outlet portion with a valve seat; a valve needle arranged at least partly within the housing axially movable in the first cavity; the valve needle sealingly resting on the valve seat in a closing position to prevent a fluid flow through the fluid outlet portion and releasing the fluid flow through the fluid outlet portion in further positions; a spring arranged within the first cavity and mechanically coupled to the valve needle and to a spring rest in such fashion that it is operable to exert a spring force on the valve needle for pressing the valve needle against the valve seat; and an adjusting element including the spring rest and having an internal pressure and an axial length measured along the central longitudinal axis of the housing; the adjusting element defining a cross section taken at an intermediate location disposed between a first axial end and a second axial end of the adjusting element, the cross section smaller in area compared to a cross-sectional area of at least one of the axial ends of the adjusting element; the adjusting element having a central rotational axis and comprises a first side part facing the central rotational axis and a second side part facing away from the central rotational axis, the first side part comprising a first top portion and a first bottom portion regarding the central rotational axis; and the second side part comprising a second top portion and a second bottom portion regarding the central rotational axis; wherein the first top portion and the first bottom portion converge continuously from the first and second axial end area, respectively, to a first circular edge and the second top portion and the second bottom portion converge continuously from the first and second axial end area, respectively, to a second circular edge; wherein the axial position of the spring rest is defined by the axial length of the adjusting element and the axial length of the adjusting element varying depending at least in part on a difference between the internal pressure of the adjusting element and a fluid pressure inside the housing.