Abstract: In a gaseous-fuel-injector device for internal-combustion motor-vehicle engines, the valve body of the injector device has one or more auxiliary openings giving out onto an internal surface of the valve body in which the valve member of the injector device is slidably mounted. Said auxiliary openings are arranged in such a way as to enable the inflow of the gaseous fuel coming from the supply, not only into the inlet opening of the injector device, but also into the internal area of the valve body in which the valve member is slidably mounted, so as to obtain an effect of ventilation and flushing, by means of the flow of gaseous fuel, in an area where there tend to form deposits of the oily substances contained in the gaseous fuel.

Abstract: The injector comprises a metering servo valve for controlling a rod for opening/closing a nebulizer. The servo valve has a valve body having a control chamber provided with an outlet passage that is opened/closed by an open/close element that is axially movable. The open/close element is separate from an armature of an electromagnet, and is slidable on an axial guide element for closing the outlet passage. The open/close element is held in the closing position by a spring acting through an intermediate body. The armature can be displaced with respect to the axial guide element between a flange of the intermediate body and a projection element of the guide member, for eliminating the rebounds of the open/close element upon closing of the solenoid valve.

Abstract: A metering servovalve for a fuel injector of an internal combustion engine has an electro-actuator and a fixed valve body, which defines a control chamber communicating with an inlet and with an outlet channel. The outlet channel has at least one calibrated restriction and exits through the lateral surface of an axial stem, on which a sleeve slides, in a substantially fluid-tight manner, to open/close the outlet channel and so vary the pressure in the control chamber. The outlet channel is closed by an end portion of the sleeve that is elastically deformable in a radially outward direction, under the thrust of the fuel pressure, to increase the diameter at which the seal against the valve body is formed, with respect to a non-deformed state, and to generate an axial unbalancing force on the sleeve upon opening when the outlet channel is closed.

Abstract: The injector comprises a balanced metering servovalve to control a rod for the opening/closing of a nozzle. La servovalve has a valve body with a control chamber radially delimited by a tubular portion and fitted with an outlet passage that is opened/closed by an axially movable shutter. The servovalve is also integral with an axial stem, provided with a lateral surface, through which the outlet channel exits. The shutter is coupled to the stem in an axially sliding manner and, when it closes the outlet passage, it is subjected to substantially null axial fuel pressure. The outlet passage has a calibrated segment distanced from the shutter and close to a bottom wall of the control chamber. The calibrated segment is carried by an element fixed to the valve body in correspondence to an axial segment of the outlet passage.

Abstract: The injector comprises a dosing servo valve for controlling a rod for opening/closing a nebulizer. The servo valve has a valve body having a control chamber provided with an outlet passage that is opened/closed by an open/close element that is axially movable. The open/close element is separate from an anchor of an electromagnet, and is slidable on an axial guide element for closing the outlet passage. The open/close element is held in the closing position by a spring acting through an intermediate body. The anchor can be displaced with respect to the axial guide element between a flange of the intermediate body and a projection element of the guide member, for eliminating the rebounds of the open/close element upon closing of the solenoid valve.

Abstract: An injector with an adjustable-metering servo valve is provided. The injector has a shutter actuated by an armature of an electromagnet. The armature is mobile for an opening stroke defined by a surface of the core of the electromagnet, which is fixed in the casing by a ring nut and a hollow support of the core. The hollow support has a first contact surface that acts on a flange of the core. Set between the surface and a shoulder of the casing is a shim. An annular projection, having a second contact surface, is set between the surface and a shoulder of the casing. The second contact surface is contained at least in part in the area corresponding to the first contact surface so that the stroke of the armature is adjusted by plastic deformation of the shim or of the surface of the core.

Abstract: The metering servo valve comprises a valve body, an open/close element, and an electromagnet, and is housed in a shell of the injector. The electromagnet actuates a mobile armature for a travel defined by an arrest element, carried by the electromagnet, which is housed in a casing, fixed in the shell by means of a threaded ring nut. Said ring nut is screwed with a pre-set tightening torque on a thread of the shell. The casing has a resting surface designed to engage a shoulder of the shell. The surface is carried by an area of the casing designed to undergo deformation as a function of the tightening torque of the ring nut so as to enable fine adjustment of the travel of the armature.

Abstract: A metering servovalve for a fuel injector of an internal combustion engine has an electro-actuator and a fixed valve body, which defines a control chamber communicating with an inlet and with an outlet channel. The outlet channel has at least one calibrated restriction and exits through the lateral surface of an axial stem, on which a sleeve slides, in a substantially fluid-tight manner, to open/close the outlet channel and so vary the pressure in the control chamber. The outlet channel is closed by an end portion of the sleeve that is elastically deformable in a radially outward direction, under the thrust of the fuel pressure, to increase the diameter at which the seal against the valve body is formed, with respect to a non-deformed state, and to generate a radial unbalancing force on the sleeve upon opening when the outlet channel is closed.

Abstract: A control servo valve (8) is housed inside the casing (2) of an internal combustion engine fuel injector (1), and has a piezoelectric actuator (40), and a control chamber (13) having a fuel outlet passage (21); the outlet passage (21) comes out inside an annular chamber (34) defined by a fixed tubular portion (25) and by a shutter (32), which engages the tubular portion (25) in substantially fluidtight manner and is slid axially by the piezoelectric actuator (40) from a closed position, in which it closes the annular chamber (34) and is subjected to a zero axial resultant force by the fuel pressure, to an open position, in which the outlet passage (21) communicates with a discharge conduit.

Abstract: The injector comprises a balanced metering servovalve to control a rod for the opening/closing of a nozzle. La servovalve has a valve body with a control chamber radially delimited by a tubular portion and fitted with an outlet passage that is opened/closed by an axially movable shutter. The servovalve is also integral with an axial stem, provided with a lateral surface, through which the outlet channel exits. The shutter is coupled to the stem in an axially sliding manner and, when it closes the outlet passage, it is subjected to substantially null axial fuel pressure. The outlet passage has a calibrated segment distanced from the shutter and close to a bottom wall of the control chamber. The calibrated segment is carried by an element fixed to the valve body in correspondence to an axial segment of the outlet passage.

Abstract: The injection system comprises a high-pressure pump with variable flowrate, having at least one pumping element provided with an intake valve in communication with an intake pipe and a delivery valve in communication with a delivery pipe. A pressure regulator is set on the intake pipe downstream of a metering solenoid valve designed to meter the flowrate of the pump according to the operating conditions of the engine. The pressure regulator is designed to discharge the excess fuel into a compartment of a crankcase for lubricating the usual actuation mechanism of the pumping element. Set between an inlet of the solenoid valve and an inlet of the pressure regulator is a control volume designed to contain an amount of fuel such as to guarantee an adequate flow of fuel in an area corresponding to the inlet of the solenoid valve.

Abstract: The injection system comprises a high-pressure pump with variable flowrate, having at least one pumping element provided with an intake valve in communication with an intake pipe and a delivery valve in communication with a delivery pipe. A pressure regulator is set on the intake pipe downstream of a metering solenoid valve designed to meter the flowrate of the pump according to the operating conditions of the engine. The pressure regulator is designed to discharge the excess fuel into a compartment of a crankcase for lubricating the usual actuation mechanism of the pumping element. Set between an inlet of the solenoid valve and an inlet of the pressure regulator is a control volume designed to contain an amount of fuel such as to guarantee an adequate flow of fuel in an area corresponding to the inlet of the solenoid valve.

Abstract: The metering servo valve comprises a valve body, an open/close element, and an electromagnet, and is housed in a shell of the injector. The electromagnet actuates a mobile armature for a travel defined by an arrest element, carried by the electromagnet, which is housed in a casing, fixed in the shell by means of a threaded ring nut. Said ring nut is screwed with a pre-set tightening torque on a thread of the shell. The casing has a resting surface designed to engage a shoulder of the shell. The surface is carried by an area of the casing designed to undergo deformation as a function of the tightening torque of the ring nut so as to enable fine adjustment of the travel of the armature.

Abstract: An electroinjector is provided for controlling fuel injection in an internal-combustion engine. The electroinjector includes an electroactuator, an injection nozzle, and a pin, which is movable along an opening stroke and a closing stroke for opening/closing the nozzle under the control of the electroactuator and according to the supply pressure of the fuel into the electroinjector. A first electrical command and at least a second electrical command, which are sufficiently close to one another as to displace the pin with a profile of motion without any discontinuity in time, and such as to cause the pin to perform a first opening displacement and, respectively, a second opening displacement, are supplied to the electroactuator.

Abstract: An injector with an adjustable-metering servo valve is provided. The injector has a shutter actuated by an armature of an electromagnet. The armature is mobile for an opening stroke defined by a surface of the core of the electromagnet, which is fixed in the casing by a ring nut and a hollow support of the core. The hollow support has a first contact surface that acts on a flange of the core. Set between the surface and a shoulder of the casing is a shim. An annular projection, having a second contact surface, is set between the surface and a shoulder of the casing. The second contact surface is contained at least in part in the area corresponding to the first contact surface so that the stroke of the armature is adjusted by plastic deformation of the shim or of the surface of the core.

Abstract: A fuel-injection system (1, 1?, 1?, 1??) for an internal-combustion engine (2), of the type provided with: a tank (3) for collection of the fuel; compressor system (4) for drawing in the fuel from the tank (3) and making it available at high pressure to an storage volume (7); at least one injector (8, 8?, 8??) hydraulically connected to the storage volume (7) for taking in the fuel at a high pressure from the storage volume (7) and injecting it into a respective combustion chamber (12) of the engine (2); a fluid line (17) connecting the storage volume to the tank; and pressure-regulator means (19) in the storage volume (7) set along the fluid line (17); the pressure-regulator systems (19) are set hydraulically downstream of the storage volume (7) so as to enable a continuous flow of fuel through the storage volume (7) itself.

Abstract: A fuel-injection system (1, 1?, 1?, 1??) for an internal-combustion engine (2), of the type provided with compressor mechanism (4) for making available the fuel at a high pressure to an storage volume (7), and a plurality of injectors (8, 8?, 8??) fluidically connected to the storage volume (7) for taking in the fuel from the storage volume (7) and injecting it into respective combustion chambers (12) of the engine (2). The storage volume (7) is advantageously split into a plurality of distinct elementary storage volumes (9, 9?, 9a, 9b) fluidically connected to one another.

Abstract: A fuel-injection system in an internal-combustion engine is provided with an electroinjector (1) comprising an injection nozzle (5), and a needle (7) mobile along an opening stroke and a closing stroke for opening/closing the nozzle (5) under the control of an electroactuator device (8). The opening stroke of the needle (7) is controlled by a rod (14) pushed by the pressure of the fuel in a control chamber (15), in such a way as to keep the needle (7) normally in the position for closing the nozzle (5). The control chamber (15) is equipped with an inlet duct (18) having a pre-set diameter (D4) and with an outlet passage (24) having a diameter (D5) and controlled by a control valve (16).

Abstract: A fuel-injection system in an internal-combustion engine is provided with an electroinjector (1) comprising an injection nozzle (5), and a needle (7) mobile along an opening stroke and a closing stroke for opening/closing the nozzle (5) under the control of an electroactuator device (8). The opening stroke of the needle (7) is controlled by a rod (14) pushed by the pressure of the fuel in a control chamber (15), in such a way as to keep the needle (7) normally in the position for closing the nozzle (5). The control chamber (15) is equipped with an inlet duct (18) having a pre-set diameter (D4) and with an outlet passage (24) having a diameter (D5) and controlled by a control valve (16).

Abstract: An electroinjector is provided for controlling fuel injection in an internal-combustion engine. The electroinjector includes an electroactuator, an injection nozzle, and a pin, which is movable along an opening stroke and a closing stroke for opening/closing the nozzle under the control of the electroactuator and according to the supply pressure of the fuel into the electroinjector. A first electrical command and at least a second electrical command, which are sufficiently close to one another as to displace the pin with a profile of motion without any discontinuity in time, and such as to cause the pin to perform a first opening displacement and, respectively, a second opening displacement, are supplied to the electroactuator.