Renault S.a.s.

Nadim Malek

Andre Agneray

Xavier Jaffrezic

Laurent Levin

Marc Pariente

Maxime Makarov

Franck Deloraine

André Agneray

A process for producing an actuator configured to generate powerful ultrasonic waves and that includes a stack of alternating intermediate electrode layers and piezoelectric material layers. The method includes: forming an initial stack of alternating intermediate electrode layers and piezoelectric material layers, each end of the stack being a piezoelectric material layer or an intermediate electrode layer; firmly attaching adjacent layers to one another; cutting the initial stack into elementary blocks; and connecting the intermediate electrode layers together, in each elementary block.

Process for producing an actuator having a stack of alternating intermediate electrode layers and piezoelectric material layers

A device for injecting fuel over a cylinder head of an engine, including a tubular body, an injection nozzle forming an extension of the tubular body, a needle extending coaxially to the nozzle in a form of a rod, an end of which includes a head forming a valve on a seat supported by the injection nozzle, and an actuator configured to cause a movement of the head so as to open the valve, the needle configured to axially resonate when the same is subjected to axial pulses at a predetermined nominal frequency by the actuator. A system for mounting the device includes a spacer for bearing on the cylinder head, as well as on a front surface of the tubular body at the connection to the nozzle.

Mounting system for a resonating needle injection device

An injector including a nozzle that includes an opening and a seat, a needle movably mounted in the nozzle and having an end defining a valve in a contact area with the seat, a mechanism for vibrating the valve, a first acoustic-impedance breaking area at a first distance from the valve along the nozzle, and another first acoustic-impedance breaking area at a second distance from the valve along the needle. Each of the first and second distances is such that the respective propagation time of acoustic waves along the distance is: T=n*[&#x3b6;/2], where nis a positive integer coefficient different from zero with i=3 for the first distance and i=4 for the second distance, &#x3b6; being a period of the vibrations.

Fluid injection device

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.

Open-chamber multi-spark plug

The invention relates to an injector including a needle mounted in a nozzle and having an end defining a valve, the needle being connected at the other end to an actuator including first, second and third portions, the first and third portions being provided on either side of the second portion, the three portions being tightened together in order to form a block having two axially opposite limits, the first portion being connected with the needle at one of said limits, and an excitation means for vibrating the second portion according to setpoint period &#x3c4;. According to the invention, the length between the two limits of the block is such that the propagation time T of the acoustic waves generated by the vibrations of the second portion of the actuator and running along that length meets the equation: T=n*[&#x3c4;/2], where n is an integer positive multiplication coefficient different from zero.

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.

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Versailles, France

Nadim Malek