Abstract: The fuel injector comprises a solenoid wound around a bobbin which can be energized through electrical connections, a guideless magnetic valve member, a valve seat, a magnetic core, at least one magnetic coupling element, a fuel inlet tube and an external housing. The guideless magnetic valve member, the valve seat, the magnetic core, the at least one magnetic coupling element, the solenoid, the bobbin and the electrical connections form an electromagnetically autonomous sub assembly which comprises the entire magnetic circuit and also all the electrical components of the finished injector. The solenoid and bobbin are lodged in a spaced defined between that at least one magnetic coupling element and the magnetic core and the sub assembly is possibly tested and calibrated extensively prior to the obtention of the finished fuel injector.

Abstract: The fuel injector comprises a magnetic valve member with three dimensions of the same magnitude, a valve member seat on which the valve member is seatable, a magnetic core disposed opposite to the valve member seat and excitable by a solenoid to attract the valve member and generate a clearance between the seat and the valve member which allows the flow of fuel, and an injection section through which the fuel which has passed the clearance is injected out of the injector. The valve seat is shaped as a duct and the clearance between the valve member and the seat has a first portion of decreasing section and a second portion of increasing section.