FR2531283A1 - SELF-EXCITATION IONIZATION SWITCH FOR HIGH VOLTAGE POWER PULSES IN A CARBURETTOR ENGINE IGNITION SYSTEM - Google Patents

Abstract

THE INVENTION RELATES TO A HIGH VOLTAGE ENERGY PULSES SELF-EXCITED IONIZATION SWITCH OF A CARBURETOR ENGINE IGNITION SYSTEM. THE TUBULAR BODY 1, IN ELECTRICALLY INSULATING MATERIAL, OF THIS SWITCH CONTAINS AN ANODE 3 AND A CATHODE 4 BETWEEN WHICH IS A METAL EYE 2 WITH PHOTONS. THE BODY 1 IS COVERED ON THE EXTERIOR WITH A METAL COATING 5 CONNECTED TO EARTH. THIS DEVICE IS MOUNTED IN THE HIGH VOLTAGE CIRCUIT OF THE CARBURETOR ENGINE IGNITION SYSTEM. FIELD OF APPLICATION: IGNITION OF CARBURETOR ENGINES.

Description

The invention relates to a self-excited ionization switch for

  high voltage energy pulses

  in a carburetor engine ignition system.

  Ionization pre-igniters used in the high voltage circuit of the ignition system of a carburettor engine have been well known since the beginning of this century, as described, for example, in the US Pat. No. 992,168 and German Patent No. 253,594, etc. The solutions described in these and subsequent patents are intended to apply a high breakdown voltage to spark plug electrodes. applied to the electrodes of a spark plug depends

  many characteristics of the primary circuits (low

  voltage) and secondary (high voltage), such as the breaking current of the primary circuit, the transformation coefficient of the induction coil, the inductance of the primary winding, the capacity of the two circuits and the

  shunt resistance of spark plugs.

  The shunt resistance is due to deposits forming on the insulators of the spark plugs Due to their electrical conductivity, these deposits constitute a shunt in the gap of the spark plug, causing a loss of current This loss can be quite high for training

  a total loss of the discharge between the electrodes of the

  Ignition Some constituents of deposits formed on spark plugs can not burn under normal engine operating conditions Only carbon compounds and organic compounds can burn, while heavy metal oxides have such chemical stability that no "self-cleaning" is possible The electrical resistance of these deposits is high in cold, ranging between about 500 and 10,000 Mfl, but once

  heated to the working temperature of the candle

  mage, the resistance can be 10,000 times lower.

  Interruptions in ignition affect the power of the

  and fuel consumption According to experimental data, on a six-cylinder engine, failure 2.

  a single spark plug increases fuel consumption by 25%

  In the case of two spark plugs

  are simultaneously out of service, fuel consumption

  The working conditions of the spark plugs in the engine produce another detrimental phenomenon, namely the erosion of spark plug electrodes due to arc discharges, causing a widening of the spark plugs.

the air gap candles.

  The influence of the aforementioned phenomena increases

  the working period of the spark plug and there comes a time when the tension developed by the coil

  of induction and reduced by the loss of current can not

  to evoke a disruptive discharge in the widened interval between the electrodes of the bougie The latter is then defective. The energy required for ignition depends on the working speed of the engine When the engine is hot,

  under normal conditions, the working mixture contains

  in the cylinders has a temperature close to the auto-ignition temperature and a very low ignition energy is required for its ignition Other regimes require a very high ignition energy, A

  to know a cold engine (starting), a sudden acceleration

  idle, idling Rich mixes as well

  that poor people demand high ignition energy.

  The problems mentioned above underline the need to solve the problem of obtaining a distribution of high voltage energy pulses such that functionally correct sparks are obtained in all engine working conditions, with minimal erosion of spark plug electrodes,

  which means a long life, with a good air gap

correctly set.

  Known pre-ignition devices do not have

  solved the problem mentioned. This concerns more particularly

  erosion of spark plug electrodes,

  which problem was not addressed at all.

  In addition, the known pre-illuminating devices

  other disadvantages, namely the problem

  gaseous mixture, the problem of evacuation of gases, the pro-

  the problem of operating at high frequencies, the problem of the dispersion of the cathode material, the problem of the problem of the proper "maintenance" of the breaking voltage and the extinction voltage of the spark within appropriate limits; aging and technological problems arising during production, as well as

  that the high cost of this production.

  The object of the invention is to provide, in the existing ignition systems of the mixture, in engines

  with a carburettor, by means of high voltage pulses, a

  said energy pulses, such as a powerful spark is obtained, particularly in poor working conditions, between the electrodes of the spark plugs, and that the erosion of the electrodes of the

  spark plugs are at the same time limited and prevented.

  This goal contains two contradictions, namely

  a weaker erosion of the electrodes of the candles

  mage and the formation of more powerful sparks between

these electrodes.

  The invention will be described in more detail with reference to the accompanying drawing by way of non-limiting example and in which: FIG. 1 is a longitudinal section of a

  possible embodiment of the device according to the i-nven-

  tion; and FIG. 2 is a diagram showing the connection of the device according to the invention with the installation in

  high voltage ignition system of a carbureted engine

  tor. The body 1 of the device according to the invention is

  made in a tubular form, made of an electro-

  The working space formed inside the body 1 is closed by metal electrodes, namely an anode 3 and a cathode 4, spaced apart by one distance.

  2-photon metal, in the form of a

  this ring of a thickness n is fixed in the body, 1, inside the working space, at a distance m from the anode.

  In normal embodiments, the

  m is between 0.2 and 1 mm, the thickness N is between 0.1 and 0.5 mm and the distance x is between

  between 1.5 and 3.5 mm The enclosed space between the electri-

  trodes is filled with atmospheric air of normal

  The starting pressure of this air is between 1 and 5 bar The space between the electrodes is filled

  a special mixture only in special cases.

  The outer cylindrical surface of the body 1

  is covered with a metal coating 5 fixed firmly

  the length of which is very slightly greater than the

  total internal length of the electrodes.

  A high voltage drain 7 connected to the catheter

  of 4, is also connected to the central electrode CE of a

spark plug.

  The anode 3 is connected to a feed 6 in im-

  high voltage pulses through the resistor R. The metal coating 5 is connected to the earth M, so as to form two capacitors, a capacitance C1 and an output capacitance C 2 The value of the capacitance Cl input depends on the length over which

  the anode 3 extends into the body 1, and the value of the capacitance

  outlet tee C 2 depends on the length over which the cathode

4 extends into the body 1.

  The description of the functioning of the elements

  and all of the switch according to the invention encompasses the entire cycle characterisitic pulses high

  carburetor engine ignition system voltage.

  When high voltage pulses reach

  the value requested to cause a discharge

  ruptive between the electrodes 3 and 4 of the switch and between

  electrodes CE and ME of the spark plug, a

,

  Electrical age starts in both igniters.

  Many studies have shown that this type of electric shock has two components, namely

  a capacitive component and an inductive component.

  The capacitive component of the spark corresponds, in fact,

  to a discharge of the energy collected in the secondary circuit.

  In accordance with the invention, the input capacitance C1 and the output capacitance C 2 of the switch according to the invention

are part of this circuit.

  The capacitive discharge is manifested by a spark

  the blue and shiny one and by an explosion The current

  of the capacitive discharge is between

  hundreds and more than a thousand amperes, and its temperature k

  is about 10,000 K This discharge is followed by oscilla-

  high frequencies between a few M Hz and about 10 M Hz and subsisting during a cycle during a

  duration of up to a few millionths of a second.

  A damping of electro-magnetic oscillations

  high-frequency ticks, external to the discharge space, is provided by the resistance R of 6 d 12 k 0 -e on the input 6 of the high-voltage pulses and, with regard to the surrounding space, by the metal coating 5 which

  is connected to earth M and that plays the role of a shield

  against radio interference.

  The spark discharge begins before the pulse voltage reaches its maximum value. This explains that the capacitive discharge only spends the

  magnetic energy collected in the induction coil

  The remaining part of the energy is released by discharging

  inductive age, in the form of a spark of vio-

  lette-pale yellow This part of the dump is called

the "tail" of the spark.

  The inductive component of the discharge current is between about 10 and a few hundred m A, and the voltage is between a few hundred and a few thousand volts. The duration of this discharge is within a wide range of time, ranging from 6.

  a few microseconds to a few tenths of a millisecon-

  Among others, the invention Dermet to shorten the

  "lqueue" the spark and, simultaneously, to increase the energy

of the capacitive component.

  Research on the inflammatory process

  have shown that an increase in the speed of liberation

  ration of the energy of the spark raises its aptitude for in-

  This means that with the same amount of energy

  released, the capacitive component is more efficient than

the inductive component.

  An examination of the subject of the invention makes it possible to establish the following observations: With the energy switch according to the invention

  mounted in the high voltage circuit of the ignition system

  ge, one significantly modifies the parameters of rupture: currents of rupture reaching, at point, values being able to be four times greater; breaking power reaching, in peak, values which can be 2,3 f larger; electrical energy of the first half-phase of the U-I rupture characteristic being able to reach a value 3.3 times greater; and relative average light intensity

be 3.8 times larger.

  Other examinations of the object of the invention

  focused on the influence of the improved parameters of spark

  the on the engine work characteristics It's

  appeared that the following conditions and working regimes

  The engines have a positive influence of the invention: low speeds;

  low load and small openings in the

  admission pillon; working with a lean mixture, especially with a leaner blend than the optimal blend for minimal fuel consumption; and work with an ignition having a delay 7.

  higher than the optimal delay for a given work regime.

  During the examination, it appeared that the

  The influence of the invention was all the more obvious as the working conditions were more remote from the optimal conditions for a given regime. As a result of the distance to optimal conditions, the economy reached

up to 5%.

  The different parts of the energy switch

  according to the invention perform the following important functions

your.

  the photon eye 2 emits an initial avalanche

  electrons that cause global ionization of the

  between electrodes 3 and 4, before the disruptive discharge

  tive; the electron emission of the photon eye 2 is triggered by the high voltage of the pulse, and its

duration depends on the latter.

  The voltage change between the anode 3 and the

  cathode 4 is followed by a change of the electric field.

  This field is not homogeneous and it is focused on

  sharp edges of the electrodes This concentration is parti-

  raised on the slightly rounded edge of the cylindrical projection 3a of the anode The eye 2 with photons St placed at a relatively small distance m from this edge, the opening of the eye having a sharp edge of rounded shape, having significantly the same diameter as the

cylindrical projection 3a of the anode.

  When the voltage of the high voltage pulse rises to a value close to the disruptive predischarge value, the force of the electric field applied to the sharp and circular edge of the photon eye becomes so great that it first causes an excitement,

  then an ionization of the photon atoms of the eye, and finally

  a powerful automatic electronic broadcast -

  At this point, in the space adjacent to the sharp moving edge

  eyepiece of the eye's hole to photons, excited atoms and.

  electrons emitted by the photon-emitting eye transmit high-energy photons in the entire surrounding space, producing a very large number of electrons and initial ions which

  develop abruptly and quickly lead to a rup-

  dielectric strength of the space between the electrodes.

  The dielectric breakdown prepared and carried out in this way

  re has its own characteristics.

  The path of rupture is homogeneous and of strong section.

  The bombardment of the cathode 4 by positive ions is attenuated, a larger number of positive ions, having lower velocities, strike the largest surface of the cathode. In this way, the dispersion of the cathode is prevented.

  matter of the cathode, as well as its erosion, which con-

  cause serious problems in known pre-ignition devices One of the problems of known devices

  pre-ignition is the loss of function over time.

  It is due to the "disappearance" of the gas as a result of adsorption and a chemical reaction with the dispersed cathodic material. Since in the device according to the invention, the dispersion of the cathodic material is minimal, it is possible to use in the space between the electrodes even gases having an activity

  greater chemical and, above all, atmospheric

normal risk.

  The switch according to the invention effectively redistributes the energy in the following manner the input capacitance Cl collects the energy

  while the voltage of the high-voltage pulse is

  ve, and the latter releases the same energy in a short time, while a disruptive discharge occurs in the gap of the spark plug; the output capacitance C 2 collects energy at the same time as a disruptive discharge occurs in

  the ignition space of the switch, and it releases the energy

  At the same time, a disruptive discharge occurs in the air gap of the spark plug; the electro-magnetic energy which radiates and which is captured by the metal coating 5 is released at the same time as a disruptive discharge occurs in

the air gap of the spark plug.

  Since most of the energy

  the switch according to the invention takes a capacitive form.

  However, the process of spark formation between the spark plug electrodes is characterized by a noticeable shortening of the "tail" of the spark, which reduces

  significantly the erosion of the electrodes of the candle.

  Under the normal working conditions of an engine, the energy required for the initial ignition of the mixture is about 3 m. A study of the device according to the invention has established that the amount of electrical energy

  present in the first half-period of the

  U-I tick of the disruptive discharge is between 34 and 86 m J.

  it follows from the previous description that

  the device according to the invention makes it possible to improve

  the operation and performance of carbureted engines. The simple realization of the device according to

  the invention enables its cheap production, and its ease of

  The mounting unit allows wide applications.

  It goes without saying that many modifications can be made to the switch described and shown

  without departing from the scope of the invention.

10.

Claims (1)

Reverb ICAT i ON 1 \ S 1 Ionization coriator self-excitation of high voltage energy pulses in a carburettor engine ignition system, characterized in that it comprises a body (1) of tubular form made of electro-insulating material and in the cylindrical interior space of which are disposed an anode (3) and a cathode (4) at a distance x one of the other, while the closed space between these electrodes , is filled with air or a mixture of other gases, a metal photon eye (2) being placed at a distance m from the anode (3), this eye being of annular shape and having a thickness N and a central hole whose diameter is approximately equal to the diameter of a cylindrical projection (3 a) of the anode. 2 Switch according to claim 1, characterized in that the body (1) has a metal coating (5) surrounding it on its outer surface, this coating (5) being of a size greater than the total length over which extend the anode (3) and the cathode (4). 3 circuit breaker according to one of the claims   1 and 2, characterized in that the anode (3) is connected to an input (6) of high voltage pulses and comprising a resistor (R), and in that the cathode (4) is connected to an output () high voltage which is connected to a spark plug center electrode (CE), while the coating   metal (5) is connected to the ground (M).