WO1988006237A1

WO1988006237A1 - Carburation device

Info

Publication number: WO1988006237A1
Application number: PCT/FR1988/000075
Authority: WO
Inventors: Jean-Louis Campos
Original assignee: Campos Jean Louis
Priority date: 1987-02-13
Filing date: 1988-02-12
Publication date: 1988-08-25
Also published as: FR2610995B1; EP0345286A1; JPH02502662A; FR2610995A1

Abstract

Carburation device comprising a first air inlet, variable in section, a fuel feed device (6) of which the flow rate depends on the size of said variable cross-section, and a regulatory device, regulating the flow of the carburized mixture (5), the variable cross-section of said air inlet being determined by the pressure of the carburized mixture at the level (194) of the regulatory device or downstream of same; said carburation device is characterized by the fact that said first air inlet is provided with a venturi, variable in cross-section (4), comprising an elastically ductile wall (102) which defines a chamber of variable volume (105), said chamber surrounding the venturi, the elastic wall corresponding when at rest to the lowest sectional measurement of the venturi, whilst elastic deformation of said wall, causing an increase in section, is caused by the application of a pressure drop within said variable volume chamber.

Description

Fuel system

The present invention relates to a fuel device allowing the improvement of the characteristics of internal combustion engines (power, consumption, torque, pollution).

Current carburetors for internal combustion engines have many drawbacks. Despite all modern research and development, no solution is entirely satisfactory as regards improving their efficiency.

Mainly because their venturi is fixed, the conditions for homogeneity of the air / fuel mixture are only met over a reduced range of use.

Indeed, it is known that the optimum homogeneity of the mixture (therefore optimum spraying of the fuel) depends on the speed of movement of the gases in the venturi. This speed must be cons and equal to 120 m / s. This condition is not met in the current state of the art.

In addition, we know that to burn 1 gram of gasoline completely, you need about 14 grams of air, this proportio corresponds to the theoretical mixture giving complete combustion. The air / fuel ratio must be constant regardless of the load. In the current state of the art, this condition is not respected

In current carburetors, the quantity of carburan delivered by the idle and normal running nozzles depends on the caliber of these and the vacuum prevailing in the venturi. The air / fuel ratio cannot be constant, which results in: - A mixture that is too rich at low speeds (high consumption, pollution, premature engine wear)

- A mixture that is too lean at high speeds (rise in engine temperature, lack of power).

The main qualities that can be asked of an engine equipped with a carburetor are:

- maximum power ;

- minimum consumption;

- frank recoveries;

- easy cold start and quick action; - good idling under load. In the current state of the art, it is obvious that one cannot develop one of these qualities without sacrificing several others.

In addition, not being able to keep constant the optimal characteristics of the gas stream (speed, air / fuel ratio) in the venturi, from idle to full speed, we use, for the recoveries, an enriching device (recovery pump ) preventing the engine from falling during acceleration. Hence additional consumption each time the accelerator pedal is pressed. In theory, the best method is to use the calorific value of the gasoline as much as possible: you have to extract as much gasoline as possible, the greatest possible work. For this, we must therefore ensure the exact dosage of the mixture and its proper physical preparation. The physical state of the mixture is determined by its homogeneity, its spraying and its complete vaporization at the time of ignition.

Experience shows that high powers are obtained with rich mixtures and low consumption with poor mixtures. The main source of pollution from internal combustion engines comes from imperfect combustion of the gases returned to the open air in the form of carbon monoxide (CO). If the air / fuel mixture sent to the engine could be completely burned, we would obtain maximum power without CO emission. Document DE-A-3231937 discloses a carburetion device comprising an air inlet with variable section, a fuel metering device with needle whose flow rate is linked to the size of said variable section and a flow regulator of the butterfly type fuel mixture. The variation of the air passage surface is made of a rectangular metal drawer, the displacement of which generates said variation.

Such a rectangular shape is not very favorable for the homogenization of the air / gasoline mixture. In addition, the fuel flow metering needle being directly attached to the drawer, this results in poor fuel distribution. The system is not very flexible, which results in a sensitivity of the device to external pressure, the power delivered therefore not being constant whatever the atmospheric pressure. This results in the fact that the power delivered by the engine decreases with the altitude of the place.

Document FR-A-7530041 discloses a double-body carburate comprising a variable section venturi. The venturi is formed by means of a variable nozzle controlled by a toric chamber. The diameter of the venturi is minimum when the toric chamber is under pressure. When the pressure in the toroidal chamber decreases, the diameter of the venturi increases. This system has several drawbacks. First of all, as it is necessary to apply pressure to the toric chamber, and consequently to the elastic nozzle, it follows that the section of the venturi is not regular and has irregularities of shape which are not favorable to the flow of the fuel mixture. Eddies are thus created and the disturbed mixture arrives in bad conditions in the engine. In addition, the aforementioned deformations fo that the passage of gases in the second body will not be completely closed at idle. Finally, this system is unsatisfactory from a safety point of view, since it requires a positive pressure action to idle the engine: if the pressure device breaks down, it may result in an increase in the power of the motor, not controlled.

Furthermore, it will be observed that the carburetor described in this document is a double-barrel carburetor. Generally it is economically and technically desirable to have, as far as possible, single-barrel carburetors capable of optimally controlling carburetion at all speeds and at cost charges.

The invention, as characterized in its claims, and in particular in claim 1, overcomes the drawbacks mentioned above and in particular those specific to the carbu¬ ration devices disclosed in the two documents mentioned above.

Thanks to its variable venturi and its fuel metering device, the invention makes it possible to lower the rate of pollution, reduce fuel consumption and improve performance of the engine. This for two main reasons:

1. The atomization of the fuel is improved in particular at low engine speed and low load.

2. The air / fuel ratio control is more precise at all speeds and at all loads, including at idle and at full opening of the throttle valve.

In addition, the variable venturi carburetor largely eliminates this kind of problem, because the cross section of the venturi depends on the air required by the engine.

For example, at maximum engine speed, the venturi is wide open and allows the passage of a sufficient volume of air to obtain maximum power. As the engine speed and power decrease, there is also a decrease in the air consumed, hence the proportional closing of the venturi. The flow velocity of the air stream in the venturi is constant over the entire operating range of the motor.

The physical preparation of the mixture is obtained thanks to the speed of the air stream in the carburetor, (independently of the engine speeds due to the variation of the venturi) from idle to maximum speed. The speed adopted for the air stream is 120 m / s, favorable for good spraying of the fuel and homogenization of the mixture, which results in ease of vaporization.

The reduced consumption results from a precise metering of the fuel, due to the use of the metering device which allows a reserve of power, an appreciable increase in the torque from idle to maximum speed, very frank recoveries, and which also facilitates the cold starts and rapid activation of the vehicle (thanks to a cold start device explained below).

In fact, as soon as the engine is started, the maximum running nozzle is actuated with the smallest section of the venturi, which gives a very rich mixture, favorable for cold starting and rapid warming up of the engine.

Idling is of exceptional quality under load, thanks to the use of the metering device which delivers the precise quantity of fuel in relation to the quantity of air admitted, via the diffuser which is presented as a mini carburetor, of which the passage section is such that the speed of the gas stream is 120 m / s. Due to the constant speed in the venturi over the entire range of use, the petrol / air ratio can be 1/14 or any other for the use of catalytic converters.

The carburetion device according to the invention comprises on the one hand, identically to conventional carburetors, a constant level tank limiting the supply of petrol and a heating base (vaporization of the mixture) provided with an acceleration flap. On the other hand, it appears:

A / A variable elastic venturi controlled either by the vacuum prevailing above the accelerator flap, or by a pump (or jack) controlled by a servomotor, which allows the gas stream to move at a constant speed of 120 m / s.

B / A central diffuser, suitable for each displacement, which ensures atomization of the fuel and maintenance of idling. c / A fuel distributor device responsible for dosing the quantity of gasoline necessary for all engine speeds by the action of a calibrated conical needle, sliding in the spray hole of the diffuser, thus allowing an arithmetic progression of the quantity admitted fuel, from idle to full load.

This progression is ensured either by a simple eff pneumatic cylinder controlled by the vacuum prevailing above the acceleration flap and limited in its stroke by an adjustable stop, or by a servo motor The latter, identically to the motor cited line 11 page 5 , is managed by an electronic unit which takes into account the following parameters:

- Cooling water temperature;

- Engine speed;

- Armospheric pressures and in the intake manifold

- Quality of exhaust gases. D / A cold start device consisting of a pull tab which actuates a switch and slightly opens the throttle valve, a three-way solenoid valve which controls a vacuum reserve enabling the cylinder cited in line 9 to be controlled.

The variable elastic venturi, introduced inside the carburetor body above the base, consists of a tube rigid cylindrical, removable, the cross section of which is determined for each cubic capacity. on which is fixed a fitting intended to receive a hose communicating the depression prevailing above the accelerator flap, or that artificially created by the tire-electronic system of which the description follows on page 10 line 10. In this tube is introduced a sleeve of elastic material with an inside diameter equal to the outside diameter of the central diffuser. The sleeve is stretched diametrically at its ends to acquire the diameter of the rigid tube, its middle always retaining the initial diameter. The shape thus obtained is that of a venturi which has the particularity of being able to vary in diameter if it is subjected to a vacuum through the connector.

The role of the variable elastic venturi is to keep the speed of the gas stream constant. The metering device dispenses the quantity of carbura necessary to charge the engine.

According to one embodiment, the reciprocating rectilinear movement of the needle is given by a servomotor (actuating a screw-nut system) controlled by the electronic unit which processes the information delivered by the lambda type probes (air coefficient equal to the ratio of the quantity of air admitted by the theoretical volume of air necessary to ensure complete combustion of the quantity of fuel dosed) to measure the quantity of oxygen in the exhaust gases, aneroid type for measuring the atmospheric and tubing pressures Finally, thermistor type intake to measure the engine temperature. For the control of the variable elastic venturi (fitted with the cylinder mentioned on page 3 line 35), the information is delivered by the ignition coil which gives the engine speed, therefore its air requirement.

The description of a fueling device for an internal combustion engine according to the invention, given by way of nonlimiting example, follows with regard to the appended drawings, in which:

- Figure 1 shows an assembly diagram of the pneumatically controlled carburetor according to the invention.

- Figure 2 shows the circuit diagram of the electronically managed carburetor according to the invention. - Figure 3 shows a diagram of the electronic management unit according to the invention.

The device shown schematically in Figure 1 comprises a constant level tank (1), provided with an emulsion tube (2) supplying the fuel, through the spray hole (6), to the needle (3) of the device progressive metering consisting of a diaphragm cylinder (11), a guide piston (15) and a spring (16).

Downstream of the air intake (9), there is a fuel mixture passage pipe (12) also called a diffuse

This pipe has a cylindrical outer shape and takes on the inside a venturi shape. This shape is determined so that the gaseous vein flows there at the speed of 120 meters per second. The diffuser (12) has, at its upper end, a fuel metering device (100) comprising the spray hole 5 and the calibrated conical needle (3). The inner end (101) of the diffuser is introduced into an elastic venturi (4) which will now be described.

The elastic venturi (4) is a var section venturi In the embodiment chosen and shown, it consists of 0 rigid tube (19) and an elastic sleeve (102) forming an elastically deformable wall. Originally, before assembly, the elastic sleeve has an inside diameter equal to the outside diameter of the diff-only (12). During this assembly, the sleeve is stretched diametrically so that each of its ends (103-104) is secured to the ends 5 (191-192) of the rigid tube (19).

It is observed that the sleeve (102) thus mounted in the rigid tube (19) constitutes with the latter a chamber (105) with variable volume, taking into account the possible deformation of the wall (102). The rigid tube (19) also comprises connection means (193 ° to vacuum means. In this case, the means (193) are constituted by a connection to a pipe (10) itself connected at (194) downstream of the venturi (4): in fact, downstream of the venturi, a vacuum is generated, when the flow regulator of the fuel mixture is opened (here conventionally constituted by a butterfly valve (5)) At idle, the flap (5) is slightly opened, thus creating a strong vacuum downstream, part of which will be stored in the vacuum accumulator (7) comprising a non-return valve (22). The variable elastic venturi (4) is closed, only the diffuser (12) allows the passage of the gas stream, which arises at the air inlet (9).

Upstream of the flap (5), the vacuum is not sufficient to draw the variable elastic venturi through the pipe (10) and increase the passage area of the gas stream. Likewise, the jack (11) cannot be moved by means of the pipes (8), (13), and of the solenoid valve (14) which is in this configuration in the "rest" state. The needle (3) is therefore kept in the retracted position and only lets through the quantity of fuel required.

In progressive acceleration, the flap (5) opens, the vacuum prevailing upstream of the latter increases and tends to increase proportionally the diameter of passage of the elastic venturi (4) via the pipe (10). This depression is communicated to the pneumatic cylinder (11) by means of the pipes (8) and (13) through the solenoid valve (14) always in the rest position. This has the effect of gradually maneuvering the needle (3) (depending on the setting of the spring (16)). The quantity of fuel emulsified by the tube (2), which passes through the metering device, enters the venturi of the diffuser (12), is sprayed, then vaporized through the heating base (17) and enters the collector intake (18). At maximum speed, the flap (5) is fully open, the vacuum upstream of it is maximum, the venturi (4) is pressed against its support tube (19). The pneumatic cylinder (11) is against its maximum stroke stop, the progressive metering needle (3) occupies its fully open position. When decelerating, the flap (5) is closed, the upstream vacuum instantly decreases, the venturi (4) closes, the jack (11) returns to the rest position, the gas stream only passes through the diffuser (12).

To start cold, the switch (20) is switched by a pull tab placed on the dashboard which slightly opens the flap (5). The three-way solenoid valve (14) connects the vacuum reserve (7) and the pneumatic cylinder (11) via the pipes (21) and (13).

A variant of the device relating to the invention, represented in FIG. 2, comprises a constant ni / water tank (1), provided with an emulsion tube (2) supplying the fuel to the needle (3) of the progressive metering device in proportion to the opening of the variable elastic venturi (4), and, in accordance with one aspect of this variant, the engine speed and its temperature, as well as the analysis of the exhaust gases, and pressures prevailing in the intake manifold (18) and in the atmosphere.

The elements bearing the references 1 to 6, 12, 17/18, 100 to 104, 191 to 194 are identical to those described in support of FIG. 1 and will not be described again here. At start-up: the flap (5) is open (slowed down accelerated by the action of a pull tab mounted on the dashboard. The venturi (is closed on the diffuser (12). The thermistor (7a) gradually indicates microprocessor control unit (8a) the engine temperature up to 50 ° C. the engine speed is taken into account on the ignition coil _(9. a) for the venturi opening (4). the sensor pressure (13a) gradually takes precedence over the thermistor (7a) as the temperature rises. The gas analysis probe (14a) is deactivated, which leads to the opening of the spray hole ( 6), inversely proportional to the engine temperature, during the heating time.

At idle: the engine having reached its operating temperature (> 50 ° C), the pull tab is released, the computer no longer takes into account the information supplied by the thermistor (7a), the variable elastic venturi (4) is closed on the diffuser (12). The aneroid pressure probe (13a) informs the computer (8a) of the atmospheric pressures and in the intake manifold (18). In this configuration, the electronic unit (8a) gives the order to the servomotor (11a) to drive the screw-nut system (15a) of the metering device to dispense the necessary fuel. The analysis probe

.UÏ LE DE RE PA EME gas (14a) informs the electronic unit (8a) of the precise fuel / air dosage (1/14), thus refining the management precision of the carburetor according to the invention.

In progressive acceleration: the flap (5) opens, the probe (13a) senses the increase in pressure in the pipe (18), the probe (14a) analyzes the residual gases, the engine speed increases. These three pieces of information are analyzed by the computer (8a) which manages the servomotors (1a) and (16a), respectively controlling the needle (3) and the venturi (4). The latter is sucked, via the pipe (10a), by the jack (20a) which is coupled to the screw-nut system (19a).

In frank acceleration: the flap (5) is opened wide and the absolute pressure prevailing in the tube (18) increases instantaneously. The computer, informed by the pressure probe (13a), by the probe (14a) and due to the increase in engine speed, gradually controls the dosing needle (3) and the venturi (4).

When decelerating: the flap (5) is closed, the pressure in the intake manifold (18) is lower than that prevailing at idle, the pressure sensor (13a) takes priority, the lambda probe (14a) is deactivated and the computer (8a) orders the actuator (11a) to completely close the spraying nail (6). The latter is reactivated automatically at 1000 rpm, or by pressing the accelerator pedal. This saves fuel.

In ^' transient low load ^' mode, on a downward route: the lambda probe (14a) is deactivated, only the information supplied by the pressure probe (13a) and the coil (9a) are taken into account.

At ^r judgment output: a delay of five seconds is provided for initializing motors (11a) and (16a); beyond this time, the carburetion device according to the invention is deactivated.

The electrical diagram, according to an embodiment of the device relating to the invention, represented in FIG. 3, comprises a microprocessor (2 ^" > a) M 68705 R3 which performs all the control and command operations, quickly and effective. In addition, the assembly is scalable by simple modification of the program

The temperature is transmitted by a CTN type probe (7a) (negative temperature coefficient), which sees its electrical resistance decrease when the engine temperature rises. The resistor (R2) supplies the probe (7a) at the terminals of which a voltage appears. In order for the microprocessor (21a) to process this information, an upgrade is carried out by the integrated circuit (22a) LM 324 and the resistors (R3), (R4). The integrated circuit (22a) is used as a linear amplifier and delivers analog information to the microprocessor which gradually perceives the evolution of the temperature. Capacitors (C4) and (C5) allow this input signal to be filtered

The exhaust gases are analyzed by a probe (14 of the LAMBDA type which has the property of becoming conductive to oxygen ions, from a temperature of about 300 ° C., and of generating an electrical voltage reflecting the variation of (lambda) .However, it is necessary to amplify this signal by the circuit (22 and the resistors (R5) (R6) which deliver analog information to the microprocessor. The latter perceives in a gradual and instantaneous fashion 0 of the quality of the exhaust gases. The gain of the amplifier is at most 5. The capacitors (C20) and (C21) allow this input signal to be filtered

The probe (13a) measuring the difference in atmospheric pressures and the intake manifold, transmits the information 5 via a coil which sees its inductance vary depending on the pressures. This coil is associated with an oscillator consisting of resistors (R11), (R12) and (R13), capacitors (C10), (C11) and (C12) and the transistor (T3).

(R11) polarizes (T3); (C10) filters the continuous signal from the 0 base of (T3) and behaves like a short circuit for the alternating current. This therefore results in mounting in a common base. (C11) allows to maintain the oscillation.

To avoid the problems of radio interference and to satisfy the norm of electromagnetic pollution, the frequency of the oscillator does not exceed 5 KHz. Finally, so that the output signal of the latter is u compliant level for the microprocessor, the transistors (T4) and (T5) buffer and adapt this signal while the capacitor (C14) filters it.

The engine speed information is taken from the coil (9a). The voltage from the latter, varying from 0 to 400 volts is divided by the resistors (R7), (R8) and integrated by the capacitor (C8).

The capacitor (C9) allows only the rising and falling edges of the signal to be recovered. The resistor (R9) serves as a load for (C9) and polarizes the base of (T2). The diode (D2) is used to protect the transistor (T3) during negative pulses transmitted by (C9). (R10) acts as a load resistor for (T2) and (C3) allows the filtering of the signal entering the microprocessor.

When the information from the ignition coil (9a) is interrupted, indicating to the microprocessor that the engine has stopped, the carburetion device, electronically controlled according to the invention, must have the fuel supply and the venturi closed.

For this, when the conductor switches off the ignition, the circuit must still be capable of supplying the motors (11a) and (16a). From this moment, a time delay of 5s is activated during which the relay (RL1) is controlled and the microprocessor orders the closure of the venturi (4) and the spray hole (6).

After this time, (RL1) is deactivated and the assembly is no longer supplied.

In order to provide a higher control current to (RL1), two inverters (23) of type 404 are in parallel. The diode (D1) prevents the coil (9a) from being activated for 5 seconds.

The motors (11a) and (16a) must rotate in both directions; for simplification, the specialized circuit (25) of type L 298 is inserted in the assembly.

The microprocessor (21a) controls the validation signals as well as the polarity signals. At the output of the circuit (25), the diodes (D5), (D6),, (D12) protect the internal motor control transistors

(11a) and (16a).

3 "" 2 "w

(R18) (R20) are resistors for reading the current flowing in the motors. For example, when the motor (11a) is supplied, the current flowing in the read resistor (R18) gives birth to a voltage which is then filtered by (R1) / (C17). Likewise, for the motor (16a). This voltage is compared to a reference given by (R21) and (R22) filtered by (C9).

When a motor is running normally, the voltage across the read resistance is lower than the reference voltage, which corresponds to a high state at the output of the comparator (22a) LM 324. 0 If a motor is in abutment mechanical, the current flowing through it increases significantly. At this time, the voltage across the read resistance is greater than the reference voltage, which gives a low state at the output of the comparator: the microprocessor (21a) gives the order to cut off the power supply to said motor.

^ 5 distinction between the engine limit stops is made at the start. In fact, when the power is turned on, the configuration of use is such that the motor (11a) is in the maximum open position while the motor (16a) keeps the venturi closed.

In order to avoid any drift or destruction, the circuit 0 (25) and the transistor (T1) are mounted on a radiator.

(R15), (C15) and (D4) allow correct initialization of the microprocessor at power up.

(R16) and (C16) supply the reference voltage to the analog / digital converter internal to the microprocessor. 5

Quartz (24), capacitors (C6) and (C7) give the clock frequency of the microprocessor.

The program reflects the specifications and can be summarized in the form of the organization chart shown below. 0

The sensors are scanned very quickly, but the reaction time of the servomotors (11a) and (16a) being relatively longer, time delays must be introduced depending on the model.

When the user turns off the ignition, timer 5 of 5s starts and the microprocessor closes the fuel supply and the

= _M "S ≈ E ER P CE: ÏΞMT venturi. If, during this time, the user wants to restart, the microprocessor automatically positions the servomotors in the start-up position.

\

Claims

1. Carburetion device comprising a first air inlet with variable section, a fuel metering device (the flow rate of which is linked to the size of said variable section, a fuel mixture flow regulator (5), the variable section of said air inlet being controlled by the pressure of the fuel mixture at or below the regulator (1 4), characterized in that said first air inlet comprises a variable section venturi (4) comprising a elastically deformable wall (102), limiting a variable volume chamber (105) surrounding the venturi, the rest state of the elastic wall corresponding to the minimum cross section of the venturi (4) while the elastic deformation of this wall, for obtaining an increase in cross-section is obtained by applying a vacuum in said variable volume chamber Device according to claim 1, characterized in that the carbura metering device nt comprises a fuel mixture passage pipe (12), of calibrated shape to maintain a constant speed of passage of the mixture, at constant determined pressure, a first end of this pipe comprising a fuel inlet (6) and means for regulation of the fuel flow (3) the second end (101) of this pipe opening into the interior of the venturi (4) and having a section less than or equal to said minimum section of the venturi.

3. Device according to claim 2, characterized in that the fuel mixture passage pipe (12) has a cylindrical external shape and in that said variable section venturi (4) consists in particular of a rigid tube (1) , of predetermined section, and of an elastic sleeve (102) having, before assembly, an internal diameter equal to the external diameter of said pipe, the sleeve being stretched diametrically at each of these ends (191, 192) and secured to the ends of the tube rigid (19), and constituting therewith said variable volume chamber, the rigid tube further comprising connection means (193) of the internal volume (105) of the chamber to vacuum means (194, 10a, 20) . 4. carburetion device according to any one of claims 2 and 3, characterized in that the fuel metering device comprises a spray hole (6) and a calibrated conical needle (3) disposed in this hole as well as means (15, 15a) for controlling the position of the needle in this hole from the pressure of the fuel mixture at the regulator (5) or downstream of the latter.

5. Carburetor device according to any one of claims 1 to 4, characterized in that the fuel mixture flow regulator comprises in a manner known per se a valve of the "butterfly" type (5).

6. carburetion device according to any one of claims 1 to 5, characterized in that it comprises a pressure tap (194) at the fuel mixture flow regulator (5) or downstream of the latter, connected directly or indirectly, on the one hand, to said variable volume chamber (105), and on the other hand, to a pneumatic cylinder (11) controlling the fuel metering device.

7. carburetion device according to claim 6, characterized in that it comprises means for connection to a vacuum tank (7) and means (14) for selectively connecting the pneumatic cylinder (11) to said outlet pressure (194) or to this tank (7).

8. Device according to any one of claims

1 to 5, characterized in that it comprises a means of measuring the pressure (13a) at the level of the fuel mixture flow regulator or downstream of the latter, vacuum generating means (20) connected to the chamber variable volume (105), logic means (8a) adapted to control, on the one hand, the fuel metering device (3) in response to signals from the pressure measurement means, and on the other hand, the generating means depression in response to signals representing engine speed.

9. Device according to claim 8, characterized in that the logic means (8a) are also adapted to correct the control of the fuel metering device (100) in response to signals delivered by a gas analysis probe (probe lambda) (14a) analyzing engine exhaust gases.

3 ~ * ^ \ "^•""k fi?! Vύ ^ή zMT