C.r.f. Societa Consortile Per Azioni

Antonio Gravina

Mario Ricco

Sergio Stucchi

Sisto Luigi De Matthaeis

Raffaele Ricco

Onofrio De Michele

Adriano Gorgoglione

Marcello Gargano

Chiara Altamura

Domenico Lepore

Annunziata Anna Satriano

Carlo Mazzarella

Silvio Canale

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. Between one injection and the next, at least one among the following quantities is varied as a function of operating parameters of the engine: duration of at least one among the electrical commands; number of the electrical commands; and distance in time between the electrical commands.

Electroinjector for controlling fuel injection in an internal-combustion engine

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.

Fuel injector with high stability of operation for an internal-combustion engine

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.

Fuel injector with balanced metering servovalve, for an internal combustion engine

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.

Metering servovalve and fuel injector for an internal combustion engine

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.

Fuel injector with adjustable-metering servo valve for an internal-combustion engine

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.

Metering solenoid valve for a fuel injector

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

Servo valve for controlling an internal combustion engine fuel injector

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.

Fuel-injection system for an internal-combustion engine

A fuel-injection system ('&#x2033;) for an internal-combustion engine (), of the type provided with: a tank () for collection of the fuel; compressor system () for drawing in the fuel from the tank () and making it available at high pressure to an storage volume (); at least one injector (&#x2032;&#x2033;) hydraulically connected to the storage volume () for taking in the fuel at a high pressure from the storage volume () and injecting it into a respective combustion chamber () of the engine (); a fluid line () connecting the storage volume to the tank; and pressure-regulator means () in the storage volume () set along the fluid line (); the pressure-regulator systems () are set hydraulically downstream of the storage volume () so as to enable a continuous flow of fuel through the storage volume () itself.

Injection system for an internal-combustion engine

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

A fuel-injection system in an internal-combustion engine is provided with an electroinjector () comprising an injection nozzle (), and a needle () mobile along an opening stroke and a closing stroke for opening/closing the nozzle () under the control of an electroactuator device (). The opening stroke of the needle () is controlled by a rod () pushed by the pressure of the fuel in a control chamber (), in such a way as to keep the needle () normally in the position for closing the nozzle (). The control chamber () is equipped with an inlet duct () having a pre-set diameter (D) and with an outlet passage () having a diameter (D) and controlled by a control valve (). The method for controlling fuel injection comprises the steps of choosing the ratio (D/D) of the aforesaid diameters so as to determine a certain rate of displacement of the needle (), and issuing to the device () a first electrical command (C) and a second electrical command (C) sufficiently close to one another to displace the needle () with a profile of motion (P) without any discontinuities in time.

Fuel-injection system for an internal-combustion engine and corresponding method for controlling fuel injection

A method is provided for controlling fuel injection in an internal-combustion engine provided with an electroinjector, including 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. The method supplies to the electroactuator 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. Between one injection and the next, at least one among the following quantities is varied as a function of operating parameters of the engine: duration of at least one among the electrical commands; number of the electrical commands; and distance in time between the electrical commands.

Method for controlling fuel injection in an internal-combustion engine

The metering valve has a shutter for a discharge conduit, and an electromagnet for controlling an armature disconnected from a relative stem and sliding along the stem by means of a sleeve. The armature is secured to the stem by a shoulder of the armature cooperating with a C-shaped ring fitted to the stem. A plate is interposed between the sleeve of the armature and a ring nut to reduce the overtravel of the armature, is locked transversely by a support of the electromagnet, and is kept resting on the ring nut by a compression spring. To secure the armature to the stem, the plate has an opening which is ineffective in reducing overtravel when the plate is moved transversely with respect to the armature.

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Valenzano, Italy

Antonio Gravina