Abstract: The injector has a hollow body housing the body of the metering valve, which has a discharge hole for discharging the usual control chamber. The hole comes out at a flat surface of the valve body, and is engaged by a flat surface of a plate, under the control of an armature of an electromagnet. The armature is in the form of a disk, has substantially no stem, is connected to the hollow body by a leaf spring hinge, and has a surface having a spherical-bowl-shaped recess. A ball is located between the recess and another recess carried by a second surface of the plate. The valve body is fixed to the hollow body by a ring nut of a given height. And, to cover the distance between the valve body and the armature, a spacer member is preferably formed in one piece with the valve body.

Abstract: A fuel injector has a fuel inlet, and a metering valve which is activated by an electromagnetic actuator to open and close an injection nozzle; the metering valve has a control chamber communicating with the inlet and defined by an end wall, in which is formed an outlet hole closed by a shutter moved along an axis by the actuator; the end wall and the shutter are defined by respective parallel, facing surfaces which rest against each other to compress the film of fuel issuing from the hole during closure by the shutter, and which have channeling formed about the hole to generate, in use, a counterpressure for the outflowing fuel.

Abstract: Gas injection system, particularly of methane, for an internal combustion engine, comprising a plurality of electromagnetically controlled injectors associated to the various cylinders of the engine, a gas distributing manifold communicating with the injectors, a reservoir feeding the distributing manifold, where the pressurised gas is accumulated.

Abstract: The device has an electric circuit for generating a first electric current of such a predetermined value as to excite the electromagnet to open the metering valve, and a second electric current of a lower value such as to keep the electromagnet excited; and a timing device for controlling the electric circuit as a function of operating conditions of the engine. The timing device also controls the electric circuit in such a manner as to vary the duration of the first current as a function of the operating temperature of the engine.

Abstract: The injector has a control rod controlled by the fuel pressure in a control chamber, and a nozzle having an injection chamber supplied with pressurized fuel for injection. The nozzle has at least one injection orifice normally closed by a pin connected to the rod and activated by the fuel pressure in the injection chamber. The control chamber has a pressurized-fuel intake conduit, and a fuel discharge conduit which is normally closed and is opened for a variable length of time depending on the amount of fuel to be injected. The pin and the rod, and/or the intake conduit and the discharge conduit, are so sized as to keep the pin and the rod hydraulically balanced in the maximum-lift position to open the orifice.

Abstract: The fitting has a high-pressure fuel supply conduit, and the injector has a hollow body having a threaded seat engaged by a threaded portion of the fitting. The fitting has a shoulder located between the threaded portion and another portion of the fitting, and the hollow body has a shoulder on a non-recessed outer surface of the hollow body. The two shoulders are precision machined so they are parallel in use; and the usual high-pressure fuel sealing washer is inserted between the two shoulders so machined. More specifically, the shoulder of the fitting has a groove housing the washer, and the shoulder of the hollow body undergoes circular spot facing to form a series of circular cavities concentric with the axis of the threaded seat and characteristic of Ra=1.6 surface roughness.

Abstract: The injector has a nozzle closed by a rod which is movable by the fuel pressure in a control chamber having a discharge conduit closed by a plug controlled by an electromagnet. The rod is movable, from a closed position closing the nozzle, to effect a maximum travel, so that the amount of fuel injected following the maximum travel is greater than a maximum amount of fuel required by the power curve. To classify the injectors, a series of injectors is prepared with corresponding rods movable from the closed position to effect the maximum travel; and the amount of fuel injected by each injector, after two strokes of the respective rod smaller than the maximum travel, is tested.

Abstract: The injector has an injector body having a seat for a metering valve in turn having a control chamber for controlling a control rod. The control chamber has an inlet conduit and a drain conduit controlled by a shutter, and is defined by two parts, one of which is defined by a bush having a through opening for guiding the control rod, and the other of which is defined by a plug member for closing the control chamber. The inlet conduit is located on the bush, and the drain conduit on the plug member. The bush is of such a diameter as to interfere slightly with at least one cylindrical portion of the seat, and is driven in fluidtight manner inside the seat so that an end edge rests on a shoulder of the seat. The plug member is fixed in fluidtight manner to the opposite end of the bush by means of a ring nut having a projection which acts along the centerline of the thickness of the bush.

Abstract: A GPL fuel system for an internal combustion engine, including a GPL fuel tank and a pump immersed in the fuel tank and driven by an electric motor, the pump being kept constantly running when the temperature is below 0° C. or above 80° C., whilst the supply voltage of the electric motor driving the pump is chopper-controlled when the temperature is between the two said values.

Abstract: An internal combustion engine fuel injector has a casing defining a nozzle; and a shutter pin having an axis, and housed in axially sliding manner inside the casing to close the nozzle by virtue of a control rod. The pin and the control rod are connected by a connecting device, which has an axial seat carried by the pin, and a head interposed between the axial seat and the control rod, and which engages the axial seat to transmit to the pin a resultant of forces directed solely along the pin axis.

Abstract: In a tank for a system for injection supply of LPG for internal-combustion engines, a number of hydraulic-connection elements associated to a service flange which closes the top opening of the tank are mounted on said flange by fixing to the bottom surface of the latter, without having any parts that are mounted via through holes of the flange. Provided inside the tank is an electrically operated pump which is fixed to the bottom wall of the tank structure and which in turn carries the structure of a level-sensing device of a capacitive type.

Abstract: A method of producing fuel injectors for internal combustion engines provides for establishing a working life of each injector conforming with the working life of the internal combustion engine on which it is installed. Each injector has an injector body having a seat; a valve body housed inside the seat so as to form an annular chamber, for receiving high-pressure fuel, and a gap communicating with the annular chamber; and a seal housed inside the annular chamber to seal the gap. The seal is sized as a function of the permanent deformation to which the seal is subjected during use of the injector, so as to achieve a working life of the injector substantially equal to the working life of the engine.

Abstract: A fuel injector has an injector body extending along a given axis; a tubular valve body housed inside a hole in the injector body and coaxial with the injector body; and an annular chamber defined by the injector body and the valve body. The method of producing the injector includes connecting the valve body to the injector body, and fixing the valve body in a given position along the axis with respect to the injector body by means of a driving operation to interference fit the valve body inside the hole in the injector body.

Abstract: The injector has a hollow body housing a fuel metering valve closed by a closing spring; and a support housing an electromagnet controlling an armature. The support is connected to the hollow body, and the armature provides for opening the valve. The armature is fitted inside the hollow body by means of a leaf spring hinge having an annular portion fixed between the hollow body and the support, and a projecting radial tongue fixed to a central portion of the armature. The tongue, together with at least one radial appendix of the leaf spring hinge, provides for arresting the armature with a predetermined clearance with respect to the core of the electromagnet.

Abstract: On-off valve intended to be arranged at the outlet of the gas accumulation reservoir in an electronic gas injection system for an internal combustion engine, presenting a valve member made of metallic material, co-operating with a valve seat made in a body, which is also made of metallic material, to ensure the good quality of tightness in all operative temperature and pressure conditions, with prolonged reliability in time.

Abstract: The system has a high-pressure pump having a number of mechanical pumping elements for pumping high-pressure fuel to a common rail; and a number of injectors communicating with the rail and activated to inject a quantity of fuel sequentially into the corresponding cylinders of the engine. Each pumping element has a delivery at least equal to the maximum draw of each injector, and is activated in phase with at least one of the injectors to minimize the variations in fuel pressure in the rail. Each pumping element may be activated by a cam, which may even have a segmented profile to effect a portion of the travel of the respective pumping element in phase with a corresponding injector.

Abstract: The injector has a hollow body housing a fuel metering valve closed by a closing spring; and a support housing an electromagnet controlling an armature. The support is connected to the hollow body, and the armature provides for opening the valve. The armature is fitted inside the hollow body by means of a leaf spring hinge having an annular portion fixed between the hollow body and the support, and a projecting radial tongue fixed to a central portion of the armature. The tongue, together with at least one radial appendix of the leaf spring hinge, provides for arresting the armature with a predetermined clearance with respect to the core of the electromagnet.

Abstract: The fuel premetering device has a valve controlled by an electromagnet and located between a delivery conduit of a high-pressure pump supplying fuel to a common rail, and a drain conduit for draining surplus fuel. The valve is normally closed by a spring, and the electromagnet is energized to open the valve in opposition to the spring. The electromagnet is energized by a current varying in response to the operating conditions of the engine, and which is varied by a control unit from zero, at which the valve is closed completely by the spring, to a predetermined value, at which the electromagnet opens the valve completely, so that premetering is self-adaptive.

Abstract: The injector has a hollow body supporting an ordinary injection nozzle and a metering valve for metering the fuel to be injected; and a support defined by a sleeve and by an end wall. The sleeve houses an electromagnet controlling the metering valve, and is fitted to the hollow body. For which purpose, there is provided a leaf spring having a ring-shaped portion engaging the end wall of the support; and a number of elastic blades, each terminating with a hook-shaped appendix which engages a corresponding retaining element on the hollow body.

Abstract: A fuel injector has an injector body and a fitting for connecting the injector body to a high-pressure fuel supply conduit. The injector body and the fitting are separate elements of the injector, and are connected to each other to connect the supply conduit and grip an end portion of the supply conduit between the injector body and the fitting.