FR2541525A1 - Enhancement to spark generating systems applicable, in particular, to motors with controlled ignition - Google Patents

Abstract

Method and apparatus improving the quality and hence effectiveness of the spark engendered by an electrical discharge. This result is obtained through the configuring of the electrodes, one of which in particular is, at least partially, covered with an insulating metal oxide.

Description

 Under apparently known conditions and under more or less significant pressures, sparks or an arc can be produced.

 It should immediately be noted that the spark is a discharge, that is to say the very rapid establishment and extinction of a current under a relatively high voltage and a fairly low intensity.

 Depending on the way in which it is produced, this current peak will give rise to practically zero oscillations or, on the contrary, relatively large and lasting (a few milliseconies).

 In a first approximation, the spark therefore appears as one of the manifestations of a direct current characterized at each instant by its voltage and its intensity or as one of the manifestations of an alternating current characterized at each instant by its voltage, its intensity, its period and its phase shift between voltage and current (period and phase shift being very variable during the passage of this very brief current).

The expression of the energy of a spark can therefore be written:
# Vi # t (direct current) #Vi cos # #t (alternating current)
The existence of these successive cos shows that sparks having apparently same voltage and same intensity can have very different efficiencies according to their mode of generation, this one giving rise to successive cos # more or less important.

 The different efficiency of two sparks is easily seen by measuring the thickness of the dielectric (paper, mica, etc.) crossed by the sparks produced between two reference spark gaps.

 In many cases, it is interesting to have, for a little different energy expenditure, sparks of maximum efficiency.

 This is the aim of the present invention, the field of application of which covers all the problems where the quality of the spark is important either for igniting an air-fuel mixture (case of spark-ignition engines), or for generating at the same time time a certain amount of dto onc.

 It is characterized by the configuration of the parts between which the spark occurs.

One of these parts is metallic and does not have any special treatment and accepts all alloys; it has, preferably, a shape of revolution- slightly concave with respect to the a @@ re piece, and it is tapered or serrated on the edges,
The other of these parts comprises two parts: - a metal support of any thickness, - an insulating layer made up of a suitable material: metal oxide such as aluminas titanium oxide, zirconium oxide, chromium oxide , etc ..., the thickness of this layer can vary between 10 microns and one millimeter depending on the material and the desired effect.

 These parts can be secured to two arms as in normal spark gaps, but they can also be mounted in a different way: for example, the second part can be a washer crossed by an insulating tube used for the passage of the conductive wire of the first room.

 The distance between the tapered edge and the second part must be slightly less than that which corresponds to the maximum disruptive tension which the system generating the discharge can provide in the medium in question.

 As examples, two diagrams relating to the transformation of a spark plug show the manner of implementing the method thus described.

 Figure 1 shows the two parts required for processing: - a washer (1), one of the faces of which carries the insulating layer, - a shaped metal part (2) welded to the central part.

Figure (2) shows another possible solution: - an element constitutes a part. shaped ceramic (3),
a metal part (4) assembled
by welding through the ceramic piece
mique (3), - a cover washer (5) spot welded to the base of the spark plug.

 The implementation of this process leads to simple devices whose superior efficiency is obvious: the clearly higher production of ozone is irrefutable proof.

 Finally it should be noted that. data external to the apparatuses based on the process, object of this patent are important conditions of a good efficiency: nature of the discharge which must be as little oscillating as possible and correct direction of the current (metallic element connected to the positive blade).

Claims (4)

R E V E N D I C A T I O N S 1) Method and apparatuses improving quality, do @@ i7effectiveness of 11 spark caused by an electric discharge characterized by a spark detector system where one of the electrodes is a metal while the other is an assembly made up of a covered metallic support an insulating layer of a metal oxide. 2) Process and apparatus improving quality; therefore the efficiency of the spark caused by an electric discharge, according to claim 1, characterized by a discharge system as little oscillating as possible, therefore practically without damping. 3) Method and apparatus improving the quality, therefore the efficiency of the spark caused by an electric discharge, according to claim 1, characterized by an insulating layer on the second electrode made of metal oxides such as alumina, titanium oxide, chromium oxide, oxide of zirconium.  k) Process and. apparatus for improving the quality, and therefore the efficiency, of the spark caused by an electric discharge, according to claim 1, characterized in that the metal electrode is connected to the positive blade of the pulse-generating element while the other electrode is connected to the negative pole. 5) All the applications resulting from the improvement in the quality of the spark or from the greater production of ozone when these pairings implement the provisions thus brought to light.