Abstract:
A fuel pump for a direct injection system having: a pumping chamber; a piston, which is mounted in a sliding manner on the inside of the pumping chamber; an intake channel, which originates from a wall of the pumping chamber and has a housing portion; an intake valve, which is inserted into the housing portion of the intake channel; and a locking ring nut with an annular shape, which is threaded and is screwed into the housing portion of the intake channel so as to strike against the intake valve; the housing portion has an annular abutment, which reduces the diameter of the housing portion and against which the intake valve strikes; the locking ring nut is screwed into the housing portion with a tightening force that is sufficient to determine a plastic deformation of the annular abutment against the intake valve.
Abstract:
Fuel pump for a direct injection system provided with a common rail; the fuel pump has: a pumping chamber defined in a main body; a piston which is mounted in a sliding manner inside the pumping chamber to cyclically vary the volume of the pumping chamber; an intake channel which originates from a wall of the pumping chamber; an intake valve which is coupled to the intake channel; a delivery channel which originates from a wall of the pumping chamber; a delivery valve which is coupled to the delivery channel; and an actuating spring which has a plurality of turns having a pitch between the turns being variable and coupled to the piston so as to push the piston towards a maximum volume or minimum volume position of the pumping chamber.