Renault Vehicules Industriels

Jean-Louis Dazzi

Jean-Louis Froment

A method of controlling injection timing and an apparatus using the method. The method includes the steps of transmitting a first pulse to a first valve member movably disposed in an injector nozzle holder, moving the first valve member in response to the first pulse to bring first predetermined passageways into registry to initiate an injection cycle, transmitting a second pulse to a second valve member coaxially disposed relative to the first valve member and moving the second valve member in response to the second pulse to bring second predetermined passageways into registry to end an injection cycle.

Method and apparatus for controlling fuel injection

A means to cut off the feeding of combustible fluid under pressure to an injector needle of a diesel engine which is stuck in the open position. The end portion of a push rod which insures the closing of the injector needle under the push of a spring includes a throat which it slides across an orifice of a predetermined cross-sectional area of value S. The orifice is in communication with a chamber wherein is mounted a differential piston. The chamber also is connected to a discharge passage by a calibrated orifice whose cross-section S is directly related to the cross-section of the orifice. At the end of each injection stroke, the throat terminates communication with the orifice of cross-section S and the pressure in the chamber is reduced before the piston is displaced. If the needle of the injector sticks in the open position, then the throat remains in communication with the orifice and the pressure in the chamber continues to increase sufficiently to overcome a preloaded spring to move the piston in the chamber which in turn is adapted to block the feeding canal 20 of the combustible fluid distribution system thereby insuring closing of the injector needle.

Injector system for an internal combustion engine

A fuel injection apparatus for controlling fuel injectors for internal combustion engines which injectors remain normally shut as a result of a high fuel pressure applied on either side of injector fuel nozzles. The apparatus of the present invention includes a first slide valve member which, by sliding from one extreme position to another, is able to lower the pressure below a fuel nozzle associated with a fuel injector to start a fuel injection cycle in that injector. The apparatus also includes a second slide valve member which, by sliding from one extreme position to another, is able to increase the pressure below the fuel nozzle to end the fuel injection cycle and control the duration of the fuel injection cycle as well as the flow rate of the injected fuel. The first and second slide valve members return to their initial positions after two consecutive fuel injection cycles.

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Saint Genis Laval, France

Jean-Louis Dazzi