Patent ID: 7458529

Claim:
A metering servovalve for the fuel injector of an internal-combustion engine, comprising a valve body and an open/close element controlled by an armature of an electromagnet, said servovalve being housed in a cavity of a casing of said injector; said electromagnet comprising a magnetic core fixed in said cavity by means of a threaded element; said armature being designed to perform a given travel defined by a pair of opposed arrest elements, and said threaded element being screwed on a thread of said casing with a pre-set tightening torque such as to prevent any accidental loosening of said threaded element; an adjustment shim being set between said magnetic core and a shoulder of said cavity; wherein said adjustment shim is positioned in contact with said magnetic core whereby the pre-set tightening torque of the threaded element on the thread of the casing causes a compression between the magnetic core and the adjustment shims with the adjustment shim being formed of a material softer than that of said magnetic core to prevent any plastic deformation of the magnetic core by the axial load produced by said pre-set tightening torque, the material of said adjustment shim being such that said axial load guarantees a predetermined elastic deformation of said adjustment shim that is configured to prevalently undergo flexure deformation but still provides adequate stiffness to maintain the height of the shim.