Abstract: A fluid injection device having a main injection axis and including at least: a housing; an actuator axially mounted in the housing and including a stack with two axially opposed front faces and including at least one electro-active portion with an electro-active material; and a pre-stressing mechanism adapted for at least partially pre-stressing the stack. The pre-stressing mechanism includes at least a tightening clamp outside the stack and provided between the stack and the housing.

Abstract: A radiofrequency plasma spark plug configured to equip a combustion chamber including: an annular shell with a main axis; a central electrode made of a conductive material, extending along the main axis and including an inner portion arranged inside the annular shell and an outer portion arranged outside the annular shell; an annular electrically insulating part extending at least about the inner portion of the central electrode so as to be interposed between the shell and the electrode, the insulating part only covering part of the outer portion of the central electrode. The insulating part includes an annular flange concealing the entire circular terminal surface of the shell relative to the uncovered part of the electrode.

Abstract: A supply device for a radio frequency ignition system, including a supply circuit to provide a supply voltage to an output connected to a plasma generation resonator at a frequency defined by a control signal provided by a control device for the supply circuit. The control device includes a receiver interface for a determination request for the optimum control frequency, a receiver interface for receiving signals measuring the voltage at the pins of a capacitor in the supply circuit, a determination module for the optimum control frequency, to provide successive different control frequencies for the supply circuit for successive ignition commands on reception of a request and to determine an optimum control frequency based on received measured signals.

Abstract: A load measuring circuit including a cable including first and second conductors and a shielding. The conductors are connected by a first end thereof to a load, the shielding is not connected to a ground at the end, and the conductors are connected to a generator by the second end thereof. A transformer includes a first winding connected to a conductor on the second end of the cable, a second winding is connected between a ground and the shielding on the second end of the cable, and a third winding is connected to a current measuring member.

Abstract: A spark plug for an internal combustion engine of a motor vehicle; the spark plug is embodied with a generally essentially long shape and includes: an essentially capacitive lower part including two coaxial electrodes, one of which is a central electrode, and the other a threaded shell for screwing in the spark plug on the engine; and an essentially inductive upper part including a central winding including a plurality of coils wound around a coaxial mandrel, an envelope, and an insulator inserted between the envelope and the winding. The essentially capacitive part and the essentially inductive part are mechanically interconnected as to enable transmission of a clamping couple applied to the envelope to the essentially capacitive lower part. The mandrel can be elastically deformed as to compensate effects of dilation of the insulator.

Abstract: A generator of a pseudoperiodic logic signal of mean period Tmean includes: a reference clock of period Tref, a logic memory, changing state on receipt of a pulse, a first mechanism producing a normal pulse on completion of a base time interval Tsec=K×Tref, with K an integer, a second mechanism producing a shifted pulse on completion of a modified time interval T?sec=(K±1)×Tref, and a selector capable of selecting the mechanism that produces the pulse, in such a way as to regularly include a shifted pulse so as to correct the mean period, to generate a pseudoperiodic signal. Such a generator may find application, as an example, to driving a resonator for producing a plasma spark for radiofrequency ignition.

Abstract: A radio frequency plasma generator power supply, including: an interface that receives a request to determine an optimal control frequency; an output interface configured to be connected to a plasma generation resonator; a power supply module configured to apply a voltage at a set point frequency to the output interface, the voltage, depending on its frequency, selectively unable to allow generation of plasma of the resonator on receipt of a request during a phase optimizing power supply frequency of the generator and able to allow generation of plasma of the resonator during an operating phase; an interface that receives an electrical measurement of power supply of the resonator; a module that determines optimal control frequency, successively provides various set point frequencies to the power supply module on receipt of a request, and determines an optimal control frequency depending on electrical measurements received by the reception interface.

Abstract: An internal combustion engine radio frequency spark plug including two plasma-generating electrodes, separated by an insulator, that constitute respectively an outer shell enclosing the insulator and a central electrode housed in a central bore of the insulator. The spark plug includes a deep opening over the entire circumference of the shell, forming a heat-exchanger chamber inside the spark plug shell, opening outwards.

Abstract: A device for controlling a power supply of a radio frequency ignition of a combustion engine, including: an interface that receives measurement signals of operating parameters of a combustion engine; an interface that outputs a control signal; a module that stores relationships between measurement signals and the frequency of a control signal to be generated; a module that determines the frequency of a control signal to be generated on the basis of measurement signals received on the reception interface and of the relationships stored; and a module that applies the control signal at the determined frequency.

Abstract: A device for measuring an ionization current of a spark plug of a type with a resonant structure, including a motor vehicle ignition system, the spark plug being coupled to a generator including a regulating capacitor. The generator includes a polarizer that polarizes the spark plug, connected between the generator and the spark plug, and a device that measures ionization current of the spark plug, connected between the regulating capacitor and ground.

Abstract: A radiofrequency plasma spark plug configured to equip a combustion chamber including: an annular shell with a main axis; a central electrode made of a conductive material, extending along the main axis and including an inner portion arranged inside the annular shell and an outer portion arranged outside the annular shell: an annular electrically insulating part extending at least about the inner portion of the central electrode so as to be interposed between the shell and the electrode, the insulating part only covering part of the outer portion of the central electrode. The insulating part includes an annular flange concealing the entire circular terminal surface of the shell relative to the uncovered part of the electrode.

Abstract: An essentially-elongated spark plug for an internal combustion engine of a motor vehicle, including: an essentially-capacitive lower part including two coaxial electrodes; an essentially-inductive upper part including a central mandrel, a coaxial winding around the mandrel, and an external tubular casing that serves as electromagnetic armour; and an insulant disposed radially between the casing and the winding. The essentially-inductive upper part includes a second internal casing of electromagnetic armour, which is disposed radially between the insulant and the external casing.

Abstract: A spark plug for an internal combustion engine of a motor vehicle; the spark plug is embodied with a generally essentially long shape and includes: an essentially capacitive lower part including two coaxial electrodes, one of which is a central electrode, and the other a threaded shell for screwing in the spark plug on the engine; and an essentially inductive upper part including a central winding including a plurality of coils wound around a coaxial mandrel, an envelope, and an insulator inserted between the envelope and the winding. The essentially capacitive part and the essentially inductive part are mechanically interconnected as to enable transmission of a clamping couple applied to the envelope to the essentially capacitive lower part. The mandrel can be elastically deformed as to compensate effects of dilation of the insulator.

Abstract: The invention relates to a plasma-generating spark plug which undergoes excitation in the radio frequency domain. The invention comprises at least one first metallic electrode (12, 14), an insulator (13), one of which is equipped with a housing (130) in which the other element (13, 14) is mounted with a gap (15, 16) therebetween. The surface of the insulator (13) opposite the first electrode (12, 14) is metallised.

Abstract: A fuel injector for an internal combustion engine, particularly of inwards or outwards opening needle injector type, includes an injector body, e.g., forming a nozzle ending in an injection office, a mechanism for closing off the injection orifice of the injector body, the closing-off mechanism including a vibrating pintle ending in a head for closing off the injection orifice, a return mechanism returning the closing-off to the position in which they close off the injection orifice, and a mechanism for setting the pintle and/or the nozzle into cyclic longitudinal vibration so as to open and close the injection orifice alternately. The fuel injector includes a selectively activatable mechanism immobilizing the pintle with respect to the body.

Abstract: A load measuring circuit including a cable including first and second conductors and a shielding. The conductors are connected by a first end thereof to a load, the shielding is not connected to a ground at the end, and the conductors are connected to a generator by the second end thereof. A transformer includes a first winding connected to a conductor on the second end of the cable, a second winding is connected between a ground and the shielding on the second end of the cable, and a third winding is connected to a current measuring member.

Abstract: A fuel injecting device and method of controlling the fuel injection device. The fuel injection device includes a cylindrical body, a needle whose end includes with a head forming a valve on a seat supported by the end of the cylindrical body, an actuator made of an electroactive material, including a rod and that displaces the head such that the valve is opened, and a prestressing device holding the needle and a counterweight such that they are pressed against the rod opposite end. The needle extends coaxially to the cylindrical body in a form of a rigid bar and axially resonates when exposed to axial pulses at a determined excitation frequency by the actuator.

Abstract: A control device including: an input terminal for receiving a logic control signal; an output terminal for delivering an output control signal from the high-voltage MOS transistor; a first NMOS control transistor with low internal impedance, which is connected between ground and the output terminal and the gate of which is connected to the input terminal; and a second PMOS control transistor, which is connected between a supply terminal and the output terminal and the gate of which is connected to the input terminal by a bipolar transistor mounted to a common base, and which is current controlled at the emitter thereof by a capacitive connecting circuit.

Abstract: A spark plug for a motor vehicle internal combustion engine, substantially elongated in shape, and including: two coaxial electrodes of an inner central electrode and an outer base electrode enclosing the central electrode; and an electrically insulating annular block, interposed between the central electrode and the base electrode and including an annular shoulder. The insulating annual block includes an annular groove located at the shoulder.

Abstract: A fuel injection device for an internal combustion engine. The fuel injection device includes an injecting head integral with an end of a needle mobile in translation inside an injection housing supplied with high pressure fuel and having a seat for the injecting head, and a piezoelectric or magnetoresistive vibratory element capable, when energized, to act on the needle, maintained by a return spring, to cause the needle to vibrate, such that the injecting head co-operates with its seat to periodically open and close a passage for fuel injection. A controller controls movement of the needle in translation, countering the return spring, independent of the vibratory element.