EP0011994B1 - Système de carburation avec contrôle du rapport carburant-air - Google Patents

Système de carburation avec contrôle du rapport carburant-air Download PDF

Info

Publication number
EP0011994B1
EP0011994B1 EP19790302676 EP79302676A EP0011994B1 EP 0011994 B1 EP0011994 B1 EP 0011994B1 EP 19790302676 EP19790302676 EP 19790302676 EP 79302676 A EP79302676 A EP 79302676A EP 0011994 B1 EP0011994 B1 EP 0011994B1
Authority
EP
European Patent Office
Prior art keywords
fuel
air
venturi
vacuum
auxiliary
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19790302676
Other languages
German (de)
English (en)
Other versions
EP0011994A1 (fr
Inventor
Harold George Abbey
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US05/962,883 external-priority patent/US4187805A/en
Application filed by Individual filed Critical Individual
Publication of EP0011994A1 publication Critical patent/EP0011994A1/fr
Application granted granted Critical
Publication of EP0011994B1 publication Critical patent/EP0011994B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M43/00—Fuel-injection apparatus operating simultaneously on two or more fuels, or on a liquid fuel and another liquid, e.g. the other liquid being an anti-knock additive
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/18—Circuit arrangements for generating control signals by measuring intake air flow
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M9/00—Carburettors having air or fuel-air mixture passage throttling valves other than of butterfly type; Carburettors having fuel-air mixing chambers of variable shape or position
    • F02M9/14—Carburettors having air or fuel-air mixture passage throttling valves other than of butterfly type; Carburettors having fuel-air mixing chambers of variable shape or position having venturi and nozzle relatively displaceable essentially along the venture axis

Definitions

  • This invention relates generally to variable Venturi carburation systems for supplying a fuel-air mixture to the internal combustion engine of an automotive vehicle, and more particularly to a system for automatically controlling the flow of fuel and air admitted into the Venturi to maintain a desired ratio thereto under varying conditions of load and speed.
  • the function of a carburetor is to produce the fuel-air mixture needed for the operation of an internal combustion engine.
  • the fuel is introduced in the form of tiny droplets in a stream of air, the droplets being vaporised as a result of heat absorption in a reduced pressure zone on the way to the combustion chamber whereby the mixture is rendered inflammable.
  • the fuel-to-air ratio in the mixture should be maintained within close tolerances in all modes of operation, such as “idle” while standing still, “slow-speeds” up to about 32 kilometers an hour, “cruising speeds” and “high speeds”.
  • the conventional practice is to provide an accelerating pump system to furnish an extra charge of fuel for accelerations, a choke system to enrich the mixture for starting a cold engine and a throttle by- pass jet for idle and slow speed, as well as a power jet or auxiliary barrels for high speed or high power operation, all in addition to the main jet.
  • Venturi size must, of necessity, represent a compromise for both high and low speed operation. Because the maximum power an engine can develop is limited by the amount of air it can breathe in, the Venturi size should offer minimum resistance to the larger volume of air flowing at high engine speed. On the other hand, a small Venturi is desirable at low engine speeds to afford sufficient air velocity for controllable fuel metering and good fuel atomisation.
  • the modern approach to this problem is the -use of two or more Venturis arranged in series and/or two or more barrels in parallel.
  • the multiple Venturi design serves two purposes: First, the added Venturis build up air velocity in the smaller primary Venturi, thereby augmenting the force available at the main nozzle for drawing the atomising fuel. Secondly, air bypassing the primary Venturi forms an air cushion around the rich mixture discharged by the Venturi, tending to improve mixture distribution by preventing fuel from engaging the carburetor walls. Idle or very slow speed is invariably served by an auxiliary jet around the edge of the throttle plate.
  • fuel-air mixtures may be introduced to the combustion chambers of an engine by means other than carburetors, as by fuel injection, supercharging and other expedients, none of these is comparable in effectiveness with the Venturi principle for efficient atomisation of volatile fuels.
  • variable-Venturi carburetors to tailor the air-fuel supply to changing engine conditions.
  • US ⁇ A ⁇ 2,066,544; US-A-3,659,572 and US-A-3,778,041 shows various embodiments of a variable-Venturi carburetor.
  • the arrangements disclosed in these patents are incapable of varying the effective parameters of a Venturi tube so as to maintain the optimum shape and area ratios of the tube throughout the operating range and to properly locate the fuel nozzles or jets in a continuously changing Venturi throat.
  • the throat of a Venturi refers to that cross-section of the airflow passage in the Venturi that is either the smallest or through which the air flow velocity is greatest, or conversely in which the static pressure is lowest.
  • US-A-4036186 discloses a carburation system in which the air/fuel ratio is controlled in response to signals indicative of engine speed and exhaust gas composition by using a by-pass valve to vary the amount of air fed into the system to form the air fuel mixture.
  • DE-A-2357465 discloses a carburetor for internal combustion engines comprising a piston slide- valve which is slidably mounted so as to vary the cross-section of the air intake channel and which also comprises a conical needle to vary the outlet cross-section of a fuel jet.
  • the slidable piston is controlled by a servo motor responsive to the operating conditions of the internal combustion engine. Neither of these two specifications are concerned with a variable Venturi system.
  • FR-A-2078528 discloses a carburation system in which the cross-section of the fuel jet and the cross-section of the air suction channel can be varied in dependence upon engine speed, the cross-section of the air suction channel being varied by virtue'of the fuel nozzle being slidably mounted therein.
  • the main object of this invention is to provide an automatically controlled carburation system which maintains that ratio of air-to-fuel which represents the optimum ratio for the prevailing conditions of load and speed to effect a marked improvement in fuel economy and to substantially reduce the emission of noxious pollutants.
  • variable-Venturi structure to which air and fuel are supplied, the flow of air being controlled by a closed process control loop having a controller responsive to a command signal that is modulated as a function of load and speed conditions.
  • an object of the invention is to provide an automatic system which maintains an optimum ratio of fuel and air, which system operates efficiently and reliably and yet lends itself to low-cost mass-production.
  • an automatic control system for supplying a fuel-air mixture to the inlet of the intake manifold of the internal combustion engine of a vehicle for regulating the ratio of air to fuel so that this ratio is optimised for prevailing conditions of engine speed and load, said system comprising a variable Venturi structure whose input is coupled to a source of combustion air and whose output is coupled to the inlet of said intake manifold, said structure including a throat and a mechanism to adjust the effective area thereof characterised in that said system further comprises:
  • an automatic control system for supplying a fuel-air mixture to the inlet of the intake manifold of the internal combustion engine of a vehicle for regulating the ratio of air to fuel so that this ratio is optimised for prevailing conditions of engine speed and load, said system comprising a variable Venturi structure whose input is coupled to a source of combustion air and whose output is coupled to the inlet of said intake manifold, said structure including a throat and a mechanism to adjust the effective area thereof characterised in that said system further comprises:
  • Air is fed into the input of the Venturi, the air passing through the throat thereof whose effective area is adjusted by a mechanism operated by a servo motor.
  • Fuel is fed into the input of the Venturi from a fuel reservoir through a main path having a fixed orifice and an auxiliary path formed by a metering valve operated by an auxiliary fuel-control motor.
  • the differential air pressure developed between the inlet of the Venturi and the throat thereof is sensed to produce an air-velocity command signal which is applied to a controller adapted to compare this signal with the set point of the servo motor to produce an output for governing the servo motor to cause it to seek a null point, thereby defining a closed process control loop.
  • the intake manifold vacuum which varies in degree as a function of load and speed conditions is sensed to govern the auxiliary fuel-control motor accordingly and is, at the same time, converted into an auxiliary signal which is applied to the controller in the closed loop to modulate the command signal in a manner maintaining an optimum air-fuel ratio under the varying conditions of load and speed.
  • the flow of air through the Venturi is controlled as a function of throat air velocity by a closed process control loop whose air velocity command signal is modulated by an auxiliary signal reflecting the degree of intake manifold vacuum developed under the prevailing conditions of speed and load.
  • a closed process control loop whose air velocity command signal is modulated by an auxiliary signal reflecting the degree of intake manifold vacuum developed under the prevailing conditions of speed and load.
  • variable-Venturi structure of the type shown in Figure 1 having a tubular casing 10 into which an air stream at atmospheric pressure is introduced.
  • the lower end of casing 10 is coupled to the intake manifold 11 of the internal combustion engine through a foot-operated throttle inlet 12.
  • a stationary ring 13 Disposed in the mid-section of casing 10 is a stationary ring 13 having an internal Venturi configuration which defines a Venturi throat 14 that surrounds the outlet of a Venturi booster 15 also having an internal Venturi configuration mounted coaxially within the casing.
  • the Venturi structure is completed by a cylindrical spool 16 having an external/internal Venturi configuration that is axially movable by means of a lever 17 pivoted on the casing 10. The lever acts to shift spool 16 upwardly toward the outlet of booster 15 to constrict throat 14 or to shift the spool downwardly to enlarge the effective area of the throat.
  • a fuel nozzle 18 which supplies fuel into the upper end of booster 15 is coupled to a fuel reservoir 19 by way of a main path which feeds a minimum amount of fuel through a fixed jet orifice 21 and by way of an auxiliary path including an auxiliary fuel metering valve 20 having a linear variable orifice which feeds a controllable amount of auxiliary fuel.
  • Auxiliary fuel metering valve 20 is operated by the spring-biased air motor 22 of a vacuum sensor 23. This vacuum sensor is coupled through a damper valve 24 to the intake manifold 11. The position of vacuum sensor motor 22, which depends on the degree of vacuum, is converted into a corresponding auxiliary signal by a manifold vacuum transducer 25. In practice, this transducer may simply be a potentiometer whose slider is operatively coupled to vacuum sensor motor 22.
  • a vacuum amplifier 26 is coupled to a sensing tap 27 communicating with throat 14 of the Venturi structure and a sensing tap 28 at the upstream end of the structure, the output of amplifier 26 being coupled to an air velocity sensor motor 29.
  • the prevailing pressure differential Pl- p 2 developed between taps 27 and 28 is sensed and amplified to produce a strong linearly proportional vacuum signal from the intake manifold source assisted by a vacuum accumulator ACC.
  • This air velocity signal operates sensor 29 coupled to a transducer 30 to produce an electrical command signal proportional to the velocity of air passing through the Venturi throat.
  • the command signal from transducer 30 is applied to an electronic controller 31 which compares this signal with the set point of servo motor 32 to produce an output for governing the operation of this motor.
  • Servo motor 32 drives lever 17, thereby defining a closed process control loop in which one variable is the air velocity through the Venturi throat. The loop serves to adjust the Venturi throat area to thereby vary the air velocity so that it complies to the set point setting.
  • Servo motor 32 operates a position feedback transducer 33 whose output is fed to the electronic controller 31 to indicate the existing position of the motor.
  • the air velocity command signal applied to electronic controller 31 is modulated by the auxiliary signal yielded by the intake manifold vacuum transducer 25 so that the operation of the controller is responsive to another variable proportional to prevailing conditions of speed and load.
  • the air-velocity command signal from transducer 30 and the auxiliary signal from transducer 25 are further modified by control signals derived from an engine temperature thermostatic switch 34 in the engine cooling system 35 and an engine-exhaust emission transducer 36 placed in the engine exhaust pipe 37.
  • a vacuum switch 38 is coupled to the manifold and is normally closed in the absence of a vacuum, the switch being coupled to controller 31.
  • the air velocity through throat 14 of the Venturi is converted by transducer 30 into a variable d-c command signal which is applied to controller 31 for comparison with the set point of servo motor 32.
  • Controller 31 yields an output which governs the servo motor 32 which, in practice, may be a pneumatic or electric motor, causing motor 32 to adjust the position of the Venturi spool 16 and the resultant area of the throat to bring about a change in air velocity until the servo motor attains its null position as determined by its set point.
  • the controller, the motor and the associated elements constitute the components of a closed air process control loop.
  • the intake manifold vacuum varies from zero to 7.2 x 10 4 N/m 2 or more under the load and speed conditions encountered in normal engine operation.
  • accelerating or heavy loads with slow to moderate speeds results in a low to increasing vacuum in a range extending from about 0.72 x 10 4 N/m 2 to a maximum of 3.6 x 10" to 5.4 x 10 4 N/m 2 .
  • Cruising represents a condition of medium load at average speed or light load at high speed, this condition resulting in an intake manifold vacuum of from 7.2 x 10 * N/m 2 or more .down to approximately 5.4 x 10 4 N/m 2 vacuum.
  • the vacuum sensor motor 22 is designed for linear movement in a vacuum range of 0 to 7.2 x 10 4 N/m 2 , this vacuum sensor motor being directly connected to metering valve 20 in the auxiliary fuel path.
  • vacuum sensor motor 22 operates transducer 25 to produce an auxiliary signal that is applied to the controller 31 of the closed process air loop to modulate the command signal reflecting air velocity as a function of the prevailing vacuum in the intake manifold.
  • the intake manifold vacuum sensor 23 therefore not only controls the flow of auxiliary fuel into the Venturi but through its associated transducer 25 which develops an auxiliary signal that depends on the prevailing vacuum in the intake manifold, it also acts to modulate the closed air loop to either increase or decrease air velocity. This in turn brings about, as a result of the changing throat pressure, an increase or decrease of fuel flow into the Venturi.
  • the fuel metering system is not only responsive to the engine's demand for more or less fuel, but it functions by way of its auxiliary signal applied to the closed process control air loop to so modify the ratio of air-to-fuel until the ratio is at the optimum value for the prevailing conditions of load and speed.
  • Damper valve 24 in the manifold vacuum line controlling the auxiliary fuel supply and the resultant auxiliary signal functions as a rate-of- change modulator, so that the transitions from acceleration to deceleration in the various modes of operation are effectively bumpless and match the driving characteristics of the vehicle. In this way, the operation is free of hesitation and the car performance is smooth, economical and efficient in all modes of operation.
  • damper 24 may be an adjustable flow check valve, an accumulator with by- pass orifices or other fluidic combinations.
  • the engine temperature thermostatic switch 34 acts to cut in resistance in the controller circuit to provide a richer fuel-air ratio when the engine temperature thermostatic switch senses a cold engine temperature and is opened thereby. Thereafter, when the engine warms up, this engine temperature thermostatic switch is closed to bypass the inserted resistance and thereby restore the leaner fuel-air ratio appropriate to operation at normal temperatures.
  • exhaust-gas sensor 36 which may be of any known conductivity or excess oxygen type, after a normal engine temperature is achieved, acts to further limit the richness of the air-fuel ratio by raising the set point in the controller 31 to increase the ratio of air-to-fuel. It is well known that the leaner the mixture, the lesser the amount of unburned hydrocarbons produced in the engine.
  • This exhaust gas sensor 36 can serve as a limiting factor that is operative after the engine is hot, so that one can control the minimum air-to-fuel ratio and thereby prevent over-enrichment in normal operation.
  • Vacuum switch 38 acts in a manner equivalent to a starting choke. When there is no vacuum, this indicates that the engine is not operating and the vacuum switch then acts to shift the variable-Venturi to its minimum position by causing servo motor 32, under the control of controller 31, to seek its minimum position. After the engine starts, the resultant vacuum in the intake manifold acts to open switch 38, thereby restoring the normal air flow signal, the Venturi system then being operated by all the other controls.
  • the first embodiment deals with an engine working with below-atmospheric induction, as in conventional carburetors or fuel injection systems.
  • the control system in accordance with this embodiment adapts to these conventional engines by means of its below-atmospheric air intake and below-atmospheric fuel induction by a carburation action from a float controlled fuel supply.
  • the air flow sensor can be controlled only from the Venturi vacuum, considering the atmosphere as a basic plenum.
  • a pressurised fuel supply is required.
  • a spray jet J disposed at the head of a centre pipe P coaxially disposed in casing 10 is provided to eject the fuel at right angles to the direction of air flow at the throat of the primary Venturi booster 15.
  • a pressurised fuel supply constituted by a fuel tank 41 whose output is fed by a fuel pump 40 through a pressure regulating valve 42 and a solenoid valve 39 to the fuel pipe.
  • Pressure regulating valve 42 acts to govern fuel pressure so that it is inversely proportional to the intake manifold vacuum. This is effected by operatively coupling the vacuum censor motor 22 to pressure regulating vaive 4 or by having the valve directly operated by the intake manifold vacuum. Pressure regulating valve 42 supplies fuel from a minimum to a maximum pressure level.
  • Vacuum switch 38 which acts as a choke in the first embodiment, cuts off fuel flow in the second embodiment by closing solenoid valve 39 when the engine is stopped. Fuel flow for starting is controlled by the ignition switch "start” or “cranking” position until the vacuum switch takes over when the engine starts.
  • the electronic circuits includes in controller 31 whose output is applied to servo motor 32 which drives the mechanism for adjusting the effective area of the Venturi throat to establish a desired air flow velocity.
  • Controller 31 is provided with a differential amplifier 45 to one input of which is applied the air-velocity command signal derived from transducer 30.
  • This transducer is operatively coupled to air-velocity sensor motor 29 responsive to the air-pressure differential P l - p 2 developed in the Venturi structure.
  • Transducer 30 is provided with an air velocity set-point adjuster 46 capable of setting the set point for the command signal to the leanest air-to-fuel ratio.
  • auxiliary fuel signal derived from transducer 25 which is operatively linked to the vacuum sensor motor 22 coupled to the intake manifold which acts also to adjust the auxiliary fuel metering valve.
  • the auxiliary fuel signal from transducer 25 is modified by the engine-temperature thermostatic switch 34 which opens when the temperature in the cooling system is cold and closes when it is hot, the open switch interposing a cold enrichment set point adjuster 47 in the auxiliary-fuel signal circuit which is shunted out by the closed engine temperature thermostatic switch when hot.
  • the output of differential amplifier 45 is therefore constituted by the air-velocity command signal as modulated by the auxiliary fuel signal and further modified by the temperature- sensing and exhaust-sensing elements included in the system.
  • This output is applied to one input of a summing junction 48 to whose other input is applied the servo-motor feedback voltage from transducer 33.
  • the feedback voltage depends on the setting of the servo motor and hence on the position of the Venturi throat adjustment mechanism.
  • Feedback adjuster 33A sets the sensitivity of response of servo motor 32.
  • the output of summing junction 48 is fed to a pair of differential amplifiers 49 and 50 forming a comparator with respect to a servo null bandwidth adjuster 51 which establishes the null set point of the servo motor.
  • the output of the comparator goes to the drive amplifier 52 for the servo motor.
  • the operation of the closed process control loop which includes servo motor 32 for varying the effective area of the throat in the Venturi structure is responsive to the air-velocity command signal as modulated by the auxiliary fuel signal reflecting the flow of auxiliary fuel into the Venturi as determined by the intake manifold vacuum, and as further modified to take into account the operating temperature of the engine and the degree of pollutants in the exhaust.
  • circuit shown in Figure 3 is designed for the first embodiment of the control system, but can readily be adapted to work with the second embodiment.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of The Air-Fuel Ratio Of Carburetors (AREA)

Claims (17)

1. Système de commande automatique de l'alimentation en mélange carburant-air de l'entrée de la tubulure d'admission (11) du moteur à combustion interne d'un véhicule, système destiné à régler le rapport carburant-air de telle manière que ce rapport soit optimisé pour les conditions existantes de charge et de vitesse du moteur et comprenant un diffuseur variable de type Venturi (13, 14, 15, 16) dont l'entrée est raccordée à une source d'air de combustion et dont la sortie est raccordée à l'entrée de ladite tubulure d'admission (11), ledit diffuseur Venturi comprenant un col (14) et un mécanisme (17) pour ajuster la section efficace de ce dernier, caractérisé en ce que ledit système comprend en outre:
A. un servo-moteur (32) accouplé fonctionnellement audit mécanisme (17) pour ajuster la section dudit col (14);
B. des moyens d'alimentation en carburant (18) comprenant une valve de dosage de carburant auxiliaire (20) qui contrôle une quantité auxiliaire de carburant pour fournir audit diffuseur du carburant devant être mélangé à l'air;
C. un moteur auxiliaire de dosage de carburant (22) accouplé fonctionnellement à ladit valve (20) pour régler l'alimentation en carburant auxiliaire;
D. des moyens (27, 28) pour mesurer la différence de pression d'air existant entre l'entrée du diffuseur Venturi (13, 14, 15, 16) et le col de celui-ci (14) pour générer un signal de commande représentatif de la vitesse de l'air traversant le diffuseur Venturi (13, 14, 15, 16);
E. un régulateur (31) pour, en réponse audit signal de commande, comparer ledit signal avec une valeur de référence préréglée du servo-moteur (32) afin de produire un signal de sortie qui est appliqué au servo-moteur (32) de telle sorte que celui-ci ajuste la section dudit col (14) dans une direction et une mesure telles que la vitesse de l'air à travers ledit diffuseur Venturi (13, 14, 15, 16) corresponde à ladite valeur de référence, ledit régulateur (31), ledit servo-moteur (32) et lesdits moyens (27, 28) de mesure de la pression d'air constituant une boucle fermée de commande de processus;
F. des moyens (23) pour détecter le degré du vide régnant dans ladite tubulure d'admission (11) en vue de commander ledit moteur auxiliaire de contrôle de carburant (22) de façon à régler en conséquence la fourniture de carburant auxiliaire, ledit degré de vide reflétant les conditions existantes de vitesse et de charge;
G. un transducteur (25) accouplé audit moteur auxiliaire de contrôle de carburant (22) pour produire un signal auxiliaire proportionnel au degré du vide, et 1
H. des moyens pour appliquer ledit signal auxiliaire audit régulateur (31) dans ladite boucle afin de moduler ledit signal de commande de telle manière que le débit d'air à travers ledit diffuseur Venturi (13, 14, 15, 16) prenne par rapport au débit du carburant une valeur pour laquelle le rapport résultant soit optimisé vis-à-vis desdites conditions existantes de vitesse et de charge.
2. Système de commande automatique selon la revendication 1, caractérisé en ce que ledit moteur comporte un tuyau d'échappement (37) et en ce que le système comprend en outre des moyens (36) qui détectent le degré de pollution des gaz émis par ledit tuyau d'échappement (37) pour produire un signal qui est appliqué audit régulateur (31) afin que celui-ci modifie le rapport carburant-air de telle manière à réduire ledit degré de pollution.
3. Système de commande automatique selon la revendication 1 ou 2, caractérisé en ce que ledit moteur comprend un système de refroidissement (35) qui renferme un détecteur de température (34) produisant un signal qui est appliqué audit régulateur (31) pour que celui-ci modifie le rapport carburant-air dans une mesure telle qu'il y ait un enrichissement en carburant aux basses températures.
4. Système de commande automatique selon l'une quelconque des revendications 1 à 3, caractérisé en ce qu'il comprend en outre un interrupteur à vide (38) accouplé à ladite tubulure (11) pour déclencher, en l'absence de vide, une commutation dans ledit régulateur (31) de manière à provoquer un effet d'enrichissement au démarrage.
5. Système selon l'une quelconque des revendications précédentes, caractérisé en ce que lesdits moyens (27, 28) pour mesurer la pression différentielle comprennent un raccord de dérivation (28) à l'extrémité supérieure du diffuseur Venturi (13, 14, 15, 16) et un raccord de déviation à hauteur du col (14) de ce dernier.
6. Système selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il comprend un outre un volet obturateur (12) actionnable par une pédale et disposé à l'entrée de la tubulure d'admission (11). ).
7. Système selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il comprend en outre un orifice fixe (21) à l'intérieur desdits moyens d'alimentation en carburant (18) pour assurer une alimentation principale minimum.
8. Système selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il comprend en outre une pompe d'appoint (43) qui fournit de l'air sous pression audit diffuseur Venturi (13, 14, 15, 16).
9. Système selon la revendication 8, caractérisé en ce que ladite valve de dosage de carburant (20) est une valve de régulation de pression (42) et en ce que le système comprend en outre une pompe (40) qui aspire du carburant d'un réservoir (41) pour l'envoyer à travers ladite valve (42).
10. Système selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il comprend en outre des moyens (24) pour régler la vitesse de variation du signal auxiliaire afin de produire un fonctionnement exempt de tout à- coup lors des transitions entre les différents modes de fonctionnement.
11. Système selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il comprend en outre des moyens (24) pour régler la vitesse de variation de l'alimentation en carburant auxiliaire afin de produire un fonctionnement régulier et économique tout au long des différents modes de fonctionnement.
12. Système de commande automatique de l'alimentation en mélange carburant-air de l'entrée de la tubulure d'admission (11) du moteur à combustion interne d'un véhicule, système destiné à régler le rapport carburant-air de telle manière que ce rapport soit optimisé pour les conditions existantes de charge et de vitesse du moteur et comprenant un diffuseur variable de type Venturi (13, 14, 15, 16) dont l'entrée est raccordée à une source d'air de combustion et dont la sortie est raccordée à l'entrée de ladite tubulure d'admission (11), ledit diffuseur Venturi comprenant un col (14) et un mécanisme (17) pour ajuster la section efficace de ce dernier, caractérisé en ce que ledit système comprend en outre:
A. une boucle fermée de commande de processus sensible à un signal et comprenant un servo-moteur (32) accouplé audit mécanisme (17) pour ajuster la section du col (14) dudit diffuseur Venturi;
B. des moyens (26, 27, 28, 29, 30) pour mesurer la vitesse de l'air traversant ledit diffuseur Venturi (13, 14, 15, 16) afin de produire un signal de commande représentatif de la vitesse de l'air, qui est appliqué à l'entrée de ladite boucle pour que le servo-moteur (32) effectue un réglage conforme à ce signal;
C. des moyens comprenant une valve de dosage de carburant auxiliaire (20) pour fournir audit diffuseur Venturi (13, 14, 15, 16) le carburant devant être mélangé à l'air à l'intérieur de celui-ci;
D. des moyens (22) pour régler ladite valve (20) en fonction du degré du vide régnant dans ladite tubulure d'admission (11); et
E. des moyens (25) qui, en réponse au réglage de la valve (20), produisent un signal reflétant ledit degré du vide et qui modulent ledit signal de commande avec ledit signal de vide afin de procurer le rapport carburant-air voulu.
13. Système selon la revendication 12, dans lequel ledit diffuseur Venturi variable (13, 14, 15, 16) est constitué par une enveloppe cylindrique (10) pourvue d'une bague fixe (13) qui présente intérieurement la configuration d'un Venturi définissant un col (14) qui entoure la sortie d'un Venturi auxiliaire (15) présentant lui aussi intérieurement la configuration d'un Venturi, et un corps cylindrique en forme de bobine (16) ayant une configuration Venturi extérieure/intérieure et qui est déplaçable axialement par rapport à la sortie du Ventùri auxiliaire pour faire varier le degré d'étranglement du col (14).
14. Système selon la revendication 13, comprenant en outre un levier (17) monté pivotant sur ladite enveloppe (10) et relié fonctionnellement audit corps en forme de bobine (16), ledit levier (17) pouvant être mis en pivotement par ledit servo-moteur (32) pour modifier la position du corps en forme de bobine (16).
15. Système selon la revendication 13 ou 14, dans lequel le carburant est introduit dans le diffuseur Venturi (13, 14, 15, 16) par une buse (18) située à hauteur de l'entrée dudit Venturi auxiliaire (15) pour diriger le courant de carburant vers le bas à travers ledit Venturi auxiliaire.
16. Système selon l'une quelconque des revendications 13 à 15, dans lequel le carburant est introduit dans ledit diffuseur Venturi (13, 14, 15, 16) par un gicleur (J) situé à l'extrémité supérieure d'un tube de carburant (P) monté coaxialement dans ladite enveloppe (10) et s'étendant à l'intérieur dudit Venturi auxiliaire (15).
17. Système selon la revendication 16, dans lequel ledit gicleur (J) émet le carburant selon des angles droits par rapport à la direction du courant d'air traversant ledit Venturi auxiliaire (15).
EP19790302676 1978-11-22 1979-11-22 Système de carburation avec contrôle du rapport carburant-air Expired EP0011994B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US962883 1978-11-22
US05/962,883 US4187805A (en) 1978-06-27 1978-11-22 Fuel-air ratio controlled carburetion system

Publications (2)

Publication Number Publication Date
EP0011994A1 EP0011994A1 (fr) 1980-06-11
EP0011994B1 true EP0011994B1 (fr) 1983-01-19

Family

ID=25506460

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19790302676 Expired EP0011994B1 (fr) 1978-11-22 1979-11-22 Système de carburation avec contrôle du rapport carburant-air

Country Status (2)

Country Link
EP (1) EP0011994B1 (fr)
DE (1) DE2964565D1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4595542A (en) * 1985-01-07 1986-06-17 Ford Motor Company Air atomizing throttle body

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR564576A (fr) * 1924-01-05
GB222901A (en) * 1923-04-14 1924-10-14 Frederick Henry Royce Improvements in carburettors for internal combustion engines
FR676737A (fr) * 1929-06-14 1930-02-26 Carburateur
US2066544A (en) * 1935-02-12 1937-01-05 Warren W Shaw Variable throat for fluid passages
GB479144A (en) * 1936-08-27 1938-02-01 Oliver Danson North Improvements in and connected with the mounting of wheels for motor or other vehicles
DE818592C (de) * 1950-02-16 1953-08-17 Adolf Heinrich Vergaser mit verbesserter Gemischregelung fuer alle Arten von Verbrennungskraftmaschinen
GB1238033A (fr) * 1968-08-07 1971-07-07
US3659572A (en) * 1970-01-29 1972-05-02 Mack Trucks Variable venturi carburetors
DE2006739A1 (de) * 1970-02-14 1971-08-19 Rinker, Karl, 7500 Karlsruhe Vergaser zur Gemischbildung fur Ver brennungsmotoren
US3778041A (en) * 1971-03-08 1973-12-11 C Kincade Variable venturi carburetors
US4036186A (en) * 1973-06-04 1977-07-19 Nippon Soken, Inc. Air-fuel mixture ratio correcting system for carburetor
DE2357465A1 (de) * 1973-11-17 1975-05-22 Volkswagenwerk Ag Vergaser fuer brennkraftmaschinen
FR2315008A1 (fr) * 1975-06-18 1977-01-14 Laprade Bernard Perfectionnements aux carburateurs a depression constante
DE2717230C3 (de) * 1977-04-19 1981-09-24 Pierburg Gmbh & Co Kg, 4040 Neuss Brennstoffversorgungsanlage mit einem Brennstoffzumeßventil für Gemischverdichtende, fremdgezündete Brennkraftmaschinen mit kontinuierlicher Brennstoffzugabe ins Saugrohr
JPS5849702B2 (ja) * 1977-09-17 1983-11-05 株式会社日立製作所 可変ベンチュリ型気化器

Also Published As

Publication number Publication date
DE2964565D1 (en) 1983-02-24
EP0011994A1 (fr) 1980-06-11

Similar Documents

Publication Publication Date Title
US4308835A (en) Closed-loop fluidic control system for internal combustion engines
US3906910A (en) Carburetor with feedback means and system
US4250856A (en) Fuel-air ratio automatic control system using variable venturi structure
US4387685A (en) Fluidic control system including variable venturi
US3395899A (en) Carburetor
US4187805A (en) Fuel-air ratio controlled carburetion system
US4217313A (en) Device for reducing noxious emissions from carburetor internal combustion engines
US3768787A (en) High velocity carburetor
US4118444A (en) Variable venturi carburetion system
US4539960A (en) Fuel pressure regulator
US3747903A (en) Fuel supply system
US4107920A (en) Method of and apparatus for controlling air/fuel ratio in internal combustion engine
US3376027A (en) Fuel atomizing carburetors
US4096839A (en) Internal combustion engine air-fuel ratio control system utilizing oxygen sensor
US4043305A (en) Control device for regulating the compositions of the inlet and exhaust gases of an internal combustion engine
US4335693A (en) Fuel injection apparatus and system
US4470391A (en) Air-fuel mixture intake construction for internal combustion engines
CA1155015A (fr) Carburateur a commande-regulation electronique
US4052970A (en) Air-fuel ratio control system utilizing oxygen sensor and pressure differential sensor
US4311126A (en) Fuel injection apparatus and system
EP0510585A2 (fr) Moteur à gaz
EP0011994B1 (fr) Système de carburation avec contrôle du rapport carburant-air
US4234522A (en) Variable diffuser for carburetors
US3885004A (en) High velocity carburetor
US5797379A (en) Fuel delivery system

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB IT SE

17P Request for examination filed

Effective date: 19801202

ITF It: translation for a ep patent filed

Owner name: DR. ING. A. RACHELI & C.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB IT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19830119

REF Corresponds to:

Ref document number: 2964565

Country of ref document: DE

Date of ref document: 19830224

ET Fr: translation filed
GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19840731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19840801

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19881118

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT