Magneti Marelli S.p.a.

Daniele De Vita

Marcello Cristiani

Massimo Mattioli

Luca Mancini

Michele Petrone

Paolo Pasquali

Andrea Cobianchi

Massimo Lolli

Pasquale Dragone

Enrico Vezzani

Stefano Petrecchia

Tommaso Neri

Fuel pump for a direct-injection system and having: a pumping chamber; a piston; an intake channel regulated by an intake valve; a delivery channel regulated by a delivery valve; and a drain channel that originates in the delivery channel and is regulated by a maximum-pressure valve having: a shutter, a valve body provided with a valve seat, a calibrated spring for pushing the shutter against the valve seat, and a plate that is arranged in contact with the shutter on the opposite side of the valve seat; the plate of the maximum-pressure valve has a first annular groove, which is arranged around the shutter; and the valve body of the maximum-pressure valve has a second annular groove, which is arranged around the shutter and at least partially faces the first annular groove of the plate.

Fuel pump with an improved maximum-pressure valve for a direct-injection system

The present invention relates to a fuel injector. The fuel injector is provided with an injection nozzle, an injection valve, and an electromagnetic actuator. The injection valve has a movable needle to adjust the flow of fuel through the injection nozzle. The electromagnetic actuator is adapted to move the needle between a closing position and an opening position of the injection valve and is provided with a movable plunger which is mechanically connected to the needle and has at least one feeding through hole for the passage of fuel towards the injection nozzle. The plunger is provided with a hydraulic type braking device, which is coupled to the feeding hole and hydraulically dissipates kinetic energy to slow down the opening stroke of the needle when the needle moves towards the opening position of the injection valve.

Electromagnetic fuel injector with braking device

A fuel pump for a direct injection system having: at least one pumping chamber; a piston which is mounted sliding inside the pumping chamber in order to vary cyclically the volume of the pumping chamber; an intake duct connected to the pumping chamber and regulated by an inlet valve; a delivery duct connected to the pumping chamber and regulated by a one-way delivery valve which allows exclusively a fuel flow outgoing from the pumping chamber; and a damping device, which is placed along the intake duct upstream of the inlet valve, and comprises at least one elastically deformable damping body that has internally a closed chamber filled with pressurized gas and composed of two metal plates cup shaped and welded together at their annular edges by an annular weld without interruptions.

Fuel pump with an improved damping device for a direct injection system

A fuel pump for a direct injection system comprises at least one pumping chamber, a piston slidingly mounted inside the pumping chamber to cyclically vary volume thereof, an intake duct connected to the pumping chamber and regulated by an inlet valve, a delivery duct connected to the pumping chamber and regulated by a one-way valve that allows only outgoing-fuel flow from the pumping chamber, a seat arranged below the pumping chamber around a lower portion of the piston, an annular seal housed in the seat and preventing fuel leakage along a side wall of the piston, and an annular element that delimits, on an upper side thereof, the seat housing the seal such that an axial dimension of the seat is not greater than an axial dimension of the seal to prevent the seal from axially 'shaking' inside the seat as a consequence of cyclic axial movement of the piston.

Fuel pump with reduced seal wear for a direct injection system

A direct-injection system fuel pump having: at least one pumping chamber; a piston mounted to slide inside the pumping chamber to cyclically alter the volume of the pumping chamber; an intake channel connected to the pumping chamber and regulated by an intake valve; a delivery channel connected to the pumping chamber and regulated by a one-way delivery valve that only permits fuel flow from the pumping chamber; and a drain channel regulated by a one-way, maximum-pressure valve, which opens when the fuel pressure in the drain channel exceeds a threshold value, and which has a shutter movable along the drain channel, a valve seat engaged in fluidtight manner by the shutter, and a spring calibrated to push the shutter into a position engaging the valve seat in fluidtight manner.

Direct-injection system fuel pump with a maximum-pressure valve

An embodiment of a direct injection assembly of the common-rail type provided with a fuel tank, a manifold, a high-pressure pump for feeding the fuel to the manifold, a low-pressure pump provided with an intake pipe and connected to the high-pressure pump by means of the intake pipe to feed the fuel taken from the tank to the high-pressure pump; and a shut-off valve of the ON/OFF type which is arranged along the intake pipe to adjust the delivery of the fuel fed to the high-pressure pump; and a pressure regulator, which is arranged along the intake pipe immediately upstream of the shut-off valve to keep the pressure of the fuel inside the intake pipe under a predetermined value.

Growing community of inventors

Castel San Pietro Terme, Italy

Daniele De Vita