BE343042A

BE343042A -

Info

Publication number: BE343042A
Authority: BE

Description

       

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  Carburateur pour véhicules automobiles      
La présente invention a pour objet un carburateur pour véhiuules automobiles tels que véhicules terrestres, nautiques ou aériens munis d'un   moteur â   explosion. L'objet do l'invention est de munir un tel   engin   d'un carburateur susceptible d'alimenter le moteur à   parti    d'un réservoir de combustible liquide situé à une grande distance horizontale du moteur et ! un niveau inférieur aux orifices d'admission de ce dernier. Un autre objet de   1'invention   est de permet- tre de se passer,dans des carburateurs de ce genre, d'un élé- vateur d'essence et également d'un niveau constant.

   Un troi- sième but de l'invention est d'aboutir à un meilleur/rendement 

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 ot à un meilleur fonctionnement du moteur aux bas régimes ou à la vitesse normale de   marche,   spécialement lorsque la valve ordinaire de réglage étant à peu près ouverte ou même complète- ment ouverte, le moteur à à vaincre une grande résistance ou se trouve devoir varier sa vitesse en raison des variations de la résistance qu'il a à surmonter. Un autre objet de l'inven- tion est également de permettre d'obtenir avec un moteur donné un couple moteur important aux faibles vitesses et, comme con- séquence, de donner la possibilité d'user moins souvent du chan- gement de vitesse même lorsque le moteur a une puissance rela- tivement faible par rapport au poids au véhicule.

   Enfin, l'in- vention à pour but d'assurer une économie de combustible et une carburation correcte pour toutes les vitesses du moteur. 



   L'invention est représentée à titre d'exemple aux des- sinssuivants. 



   Dans ces  dessins :   fig. 1 représente une vue schématique en élévation à petite échelle d'un châssis muni d'un carburateur conforme à la présente invention; fig, 2 est une coupe longitudinale à une échelle plus grande de l'ensemble.du carburateur proprement dit; fig, 3 représente une coupe transversale par A-A de fig. 2.; fig. 4 représente une coupe longitudinale par B-B de fige 3;   tige   5 est une élévation   à.une   échelle encore plus grande d'un détail de construction; fig. 6 représente une coupe longitudinale d'une va- riante du dispositif de carburation secondaire du carburateur.      



   Tel qu'il est représenté aux fig. 1 à 5,   le   carburateur 

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 comprend deux   parties 6,   et n reliées   l'un     à l'autre   par une tuyauteries C. La partie a est ce 'que l'on peut appeler un dispositif de carburation primaire et produit un mélange car- buré très riche en mélangeant avec de   1 air-   une grande propor- tion de combustible liquide contonue dans unréservoir Inférieur 1.

   La partie, est ce que   l'on     pourrait,. appeler   un dispositif de carburation secondaire et mélange au mélange carburé très riche produit   par a   une quantité correcte d'air pour alimenter le moteur 2 à une vitesse   quelconque,   Le dispositif a est situé tout près et au-dessus du réservoir de combustible 1 et à l'arrière du   chassie;   il est à un niveau relativement bas. 



  La   partie Il   est situé tout près du moteur et au-dessus du niveau du combustible liquide dans le réservoir 1. 



   Le dispositif de carburation primaire comprend unetube de   venturi '3   avec une partie convergente 4 et une partie diver- gente 6. La portion   rétrécie   6 de ce venturi communique par un conduit 7-8 avec une chambre 9 dans laquelle débouche un tuyau 10 fixé de même que le venturi 3 dans un bouchon 11 fixé sur ke réservoir 11. La partie inférieure du tube 10 est située légè- rement au-dessus du fond du réservoir lo Un tuyau 12 fait communiquer la partie divergente du venturi 3 avec le disposi- tif de carburation secondaire b, 
De dispositif b comporte une conduite d'admission 13 faisant   nuit   à un vonturi 14 muni d'une   parti     convergent   16 et d'une partie divergente 16.

   Dans la conduite d'admission est disposée la valve ou papillon de réglage ordinaire 17 des- tinée à permettre de régler   l'afflux   de mélange carburé au mo- teur. Dans le venturi 14, un peu en aval du col 18 du dit ven- turi, débouche le tuyau 12. En amont du venturi 14 est située l'entrée d'air 19. La section de cette entrée d'air est con- 

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 trôlée par une vanne rotative 20 montée sur des tourillons 21-22 tournant dans une boite 23.

   La vanne 20 est munie de deux ou- vertures 24-25 et-de deux parties pleines   24a-25a.   L'ouver- ture 25 est susceptible de venir coïncider progressivement avec l'entrée d'air 19 lorsque la vanne 20 tourne dans la direction de la flèche f, ouvrant ainsi progressivement cette entrée d'air jusqu'à oe qu'elle soit entièrement dégagée. les ouvertures 24-25 étant aussi grandes que l'entrée d'air 19. Sur le tourillon 22 de la vanne 20 est fixé un bras 26 qui est relié par des biel- lettes 27 à la tige 28 d'un piston 29 susceptible de se déplacer dans un cylindre 30.

   Ce cylindre communique par un conduit 31 avec l'intérieur du dispositif de carburation a, en un point si- tué entre la valve 17 et la vanne 20, de préférence entre la vanne 17 et le col 18 et plus particulièrement en un point 38 situé dans la partie divergente 16 du   ventur .   14. Un ressort 33 entourant le tourillon 22 ett fixé à l'une de ses extrémités à la boite 23 et à son autre extrémité au burs 26 tend à obliger le piston 29 4 se déplacer vers la partie inférieure du cylindre 30 et à amener la vanne 20 à fermer l'entrée d'air 19, la partie pleine 25a venant coïncider avec cette entrée d'air. 



   Lorsque le papillon 17 est fermé,ainsi que cela est re- présenté   à   la fig. 2, il n'existe aucune dépression dans le venturi 14, aucune aspiration ne se trouvant exercée sur l'ou- verture du tube 12 dans le dit venturi; il n'y a pas de dépres- sion transmise au cylindre 30 et le ressort Ci; ferme la vanne d'entrée d'air 20. 



   Lorsque, pour la marche normale, le   @pillon   a été ouvert, le moteur crée une dépression dans   1 entrée   d'air 13 et le venturi 14, dépression qui se transmet jusqu'à la vanne 

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 d'entrée d'air 20. Cette dépression agit sur 3, 'tube 12 et tout le long de ce dernier jusqu'au venturi 3. De l'air est aspiré dans ce venturi et, passant à travers le col 6 de ce dernier, il aspire du combustible liquide en   l'élevant   au travers des conduits 7 et 8, la chambre 9 et le tube 10 à partir du réservoir 1   e   produisant un   mélange   carburé très riche qui est transporté à travers le tube 12 jusqu'au ven- turi 14.

   La même dépression agit aussi à travers le conduit   31 à   l'intérieur du cylindre 30   et,   par suite, sur le piston 
29 qui comprime le ressort 33 et ouvre la vanne d'air 20. 



   Si, en marche normale, le moteur se trouve soumis à une charge telle qu'elle   l'oblige à   diminuer de vitesse la valve 17 étant cependant maintenu   ouvert,   la dépression dans la conduite d'admission 13 et le venturi 14 diminuera; la carbu- ration est alors influencée simultanément dans le dispositif a et dans le dispoaitif b et ne reste pas à sa valeur optima; mais la variation d'aspiration entre alors en jeu pour régler l'ad- mission d'air; la dépression étant   moindre   que lorsque le moteur tournait à pleine vitesse, le ressort 33, taréeon conséquence , déplacera le piston 29 d'une certaine quantité et fermera par- tiellement la vanne d'entrée d'air 20.

   La quantité d'air ad- mise diminuera en conséquence Si le ressort 33 est convenable- ment taré) l'air diminuera non seulement de façon absolue mais la aussi en proportion de la diminutiondde/quantité de mélange riche produite par le dispositif à et admise dans le disposi- tif b. 



   Plus la vitesse du moteur diminue, moins grande est la dépression dans le venturi 14 et par conséquent plus le ressort 33 fera descendre le piston 29 dans son cylindre et fermera la vanne 20. La régulation sera par conséquent con- tinue et,en déterminant convenablement la section/du piston 

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 et la force du ressort, il sera possible de maintenir la meil- leure valeur à chaque vitesse de rotation du moteur pour l'ad- mission de mélange riche et d'air au dispositif Ce disposi- tlf de régulation maintient non seulement un réglage correct quel que soit le degré d'ouverture de la vanne   17,   mais il est, de plus, particulièrement efficace lorsque le papillon 17 est entièrement ouvert et que le moteur se trouve soumis à une charge variable. 



   Le carburateur tel que représenté aux fig. 1 à 4 comprend également un dispositif de marche au ralenti qui co- opère avec le dispositif de marche normale précédemment décrit. 



   Ce dispositif de ralenti comprend un tube de venturi 34 ayant une partie convergente 35 et une partie divergente 36 et un col 37 qui communique avec un tube 38 qui s'étend jusqu'au voi- sinage du fond du réservoir de combustible liquide 1. Un tuyau 39 fait communiquer le vehturi 34 avec un conduit 40 qui débou- che dans la conduite 13 en aval du papillon de réglage   17. #La   section de ce conduit est réglée par le pointeau 41 muni d'un passage longitudinal 42 et d'un passage transversal 43. 



   Le passage 43 maintient une communication permanente entre le tuyau 39 et la conduite d'aspiration 13 tandis que le passage 42 assure une communication constante entre l'air atmosphérique et le dit conduit. 



   L'aspiration exercée par le moteur est transmise par le conduit 40 aux passages 42 et 43 et au tuyau 39 jusqu'au ven- turi 34. De   l'air   est aspiré dans ce venturi qui a pour effet d'aspirer du combustible liquide du réservoir 1; ce combustible est mélangé avec l'air qui pénètre dans le venturi et forme un mélange carburé très riche qui est transporté jusqu'à la conduite 

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 d'admission 13 par le tuyau 39. En ce point/   -le   mélange riche reçoit une addition d'air par le passage 42 de manière! réali- ser le mélange carburé de ralentie 
Lorsque le moteur tourne lentement et n'est pas sons charge, le papillon 17 est fermé et le moteur est alimenté uniquement-par le tuyau 39 au moyen du venturi 34.

   Lorsqu'il tourne à sa vitesse   normale   la valve 17 est largement ouverte et le moteur est alimenté uniquement par le tuyau 32 au moyen du venturi 3 car le passage 45 est très petit. La dépression est à ce moment très faible dans le venturi 14 et la vitesse de l'air dans le venturi 34 est en conséquence trop faible   pour'enlever   du liquide du réservoir la Il peut cependant arriver que, pour une certaine position du papillon   17   et      pour une certaine vitesse du moteur, ce dernier se trouve alimenté à la fois par le dispositif de marche normale et par le dispositif de ralenti, l'effet de la vanne de réglage d'air 20 réagissant sur ces deux dispositifs d'alimentation. 



   Il convient do dire que la   vanne   20 et son dispositif d'actionnement servent également à assurer de bonnes reprises du moteur pour le   passade   du ralenti à la marche normale lors- que, ainsi qu'il a été dit plus haut, le conduit 31 est, con- formément à l'invention, d'un diamètre suffisamment petit.

   La perte de charge dans ce conduit agit alors de manière à freiner le mouvement du piston 29 et à empêcher ainsi la vanne 20 de s'ouvrir trop rapidement lorsque   l'on   ouvre brusquement le pa- pillon 17 pour faire la reprise.   Si   la vanne 20 s'ouvrait trop rapidement, la dépression ferait pénétrer dans la conduite d'admission une trop grande quantité d'air avant'que le ven-   tant   3 soit mis de nouveau en action et que la colonne d'air 

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 et de mélange carburé dans le tube 12 soit mise.en mouvement. 



  En freinant l'ouverture de la vanne 20 lors de l'ouverture brusque du papillon 17, l'aspiration transmise au venturi 14 agit d'abord sur le tube 12, sur le venturi 3 et au même moment sur la conduite 31 mais, comme le vide se transmet lentement au piston 29, la vanne de réglage d'air 20 s'ouvre elle aussi dou- cement et l'air se trouve admis par l'entrée d'air 19 au bon moment en proportion progressive correcte par rapport à la quantité de mélange riche qui pénètre dans le venturi 14 par le tuyau 12. 



   Les reprises sont aussi facilitées par le combustible liquide accumulé dans l'évidement qui entoure le col   d.   ven- tuni 3 et qui se trouve dans le conduit 7. Lorsque l'effet de suction du venturi 3 cesse, le combustible qui remplit la cham- bre 9 s'écoule partiellement dans l'évidement auquel il vient   d'être   fait allusion dans la partie inférieure du conduit 7 et y demeure. Lorsque le venturi 3 est de nouveau mis en action, il aspire tout d'abord le combustible dans l'évidement et dans le conduit 7 provoquant ainsi un léger excès de combustible qui ajouter à l'air primaire enrichissant ainsi le mélange carburé ce qui facilite la reprise. 



   Pour assurer un meilleur fonctionnement dans la pro- gressivité de l'action de la vanne d'air 20, l'ouverture 25 peut recevoir la forme d'un V, de dentsde scie ou affecter toute autre forme réalisant une ouverture ou une fermeture progressive de l'entrée d'air pendant les mouvements d'ou- verture ou de fermeture de cette vanne. 



   Dans la variante représentée à la fig. 6, le piston 29, au lieu d'être actionné sur une de ses faces par ltaspi- ration et, d'autre part, par un piston, est actionné à sa partie supérieure par la dépression qui règne en aval de la 

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 vanne 17 par le conduit 31 et sur son autre face par la   dépres-     s ion   créée à l'ouverture d'un conduit 31b qui débouche en 31a dans le col 18 du venturi. Le piston est ainsi actionné par une dépression différentielle.

   Lorsque la valve 17 est fermée et que le carburateur fonctionne au moyen du dispositif de ra- lenti (identique à celui du carburateur de la fig. 2 mais non représenté et qui débouche en 40 dans la conduite d'admission 13), la dépression en aval de 17 attire le piston 29 vers le Haut, fermant ainsi la vanne d'entrée d'air 20 (représentée ici sous forme d'un papillon). Lorsque la valve 17 est ou- verte, la dépression en 31b étant plus grande que celle en 31, attire le piston vers le   bas   et ouvre la vanne d'air 20.

   Si, la valve 17 étant presque ou complètement ouverte,le moteur a tendance à varier de vitesse et que:, par conséquente la dé- pression dans le carburateur change, la différence entre les dépressions en 31 et 31b variera de façon similaire et le piston sera déplacé par la nouvelle différence de dépression jusqu'à ce que le   di   piston ayant fait actionner   1* appareil   de réglage d'entrée   d'air,   la dépression dans le carburateur reprenne savaleur normale et qu'ainsi l'équilibre du système de réglage d'air soit établi à nouveau, 
On voit qu'un carburateur conforme à l'invention per- met d'obtenir une beaucoup plus grande souplesse pour le mo- teur et spécialement lui permet de descendre à une vitesse de rotation très faible inférieure à celle que permettent'les carburateurs actuellement connus,

   
En fait, à faible vitesse de rotation, le couple d'un moteur alimenté par un carburateur conforme à l'invention a été constaté être beaucoup plus grand que celui d'un moteur ordinairealimenté par les méilleurs carburateurs actuellement 

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 mis sur le marché. Ceci résulte de ce que le réglage de l'ad- mission d'air dans le carburateur (dispositif de carburation primaire et dispositif de carburation secondaire) empêche le mélange carburé de devenir trop pauvre en combustible lorsque.. à vitesse réduite, la valve de réglage est largement ouverte. Il en résulte que le moteur ne peut pas être étouffé par un excès d'air et qu'il continue à se trouver dans les conditions optima d'alimentation.



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  Carburetor for motor vehicles
The present invention relates to a carburetor for motor vehicles such as land, water or air vehicles fitted with an internal combustion engine. The object of the invention is to provide such a machine with a carburetor capable of supplying the engine from a liquid fuel tank located at a large horizontal distance from the engine and! a level below the intake ports of the latter. Another object of the invention is to make it possible, in carburettors of this kind, to do without a gasoline elevator and also a constant level.

   A third object of the invention is to achieve a better yield.

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 ot better operation of the engine at low revs or at normal running speed, especially when the ordinary regulating valve being more or less open or even fully open, the engine has to overcome a great resistance or it is necessary to vary its speed due to the variations in resistance it has to overcome. Another object of the invention is also to make it possible to obtain with a given motor a high motor torque at low speeds and, as a consequence, to give the possibility of using the same speed change less often. when the engine has a relatively low power in relation to the weight of the vehicle.

   Finally, the invention aims to ensure fuel economy and correct carburetion for all engine speeds.



   The invention is shown by way of example in the following drawings.



   In these drawings: fig. 1 is a schematic elevational view on a small scale of a frame provided with a carburetor according to the present invention; Fig, 2 is a longitudinal section on a larger scale of the assembly.du carburetor itself; fig, 3 shows a cross section through A-A of fig. 2 .; fig. 4 shows a longitudinal section through B-B of fig 3; rod 5 is an elevation to an even larger scale of a construction detail; fig. 6 shows a longitudinal section of a variant of the secondary carburizing device of the carburetor.



   As shown in Figs. 1 to 5, the carburetor

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 comprises two parts 6, and n connected to each other by a piping C. Part a is what may be called a primary carburizing device and produces a very rich fuel mixture by mixing with 1 air- a large proportion of liquid fuel contons in a Lower tank 1.

   The part, is what we could ,. call up a secondary carburizing device and mixing the very rich fuel mixture produced by a the correct amount of air to feed engine 2 at any speed, Device a is located near and above fuel tank 1 and at the rear of the chassie; it is at a relatively low level.



  The part It is located very close to the engine and above the level of liquid fuel in tank 1.



   The primary carburizing device comprises a venturi tube '3 with a converging part 4 and a diverging part 6. The constricted portion 6 of this venturi communicates through a duct 7-8 with a chamber 9 into which opens a fixed pipe 10 of same as the venturi 3 in a plug 11 fixed on the reservoir 11. The lower part of the tube 10 is situated slightly above the bottom of the reservoir lo A pipe 12 communicates the divergent part of the venturi 3 with the device. secondary carburetion b,
Device b comprises an intake pipe 13 causing harm to a vauri 14 provided with a converging part 16 and a divergent part 16.

   In the intake duct is disposed the ordinary regulating valve or throttle 17 intended to allow the flow of fuel mixture to the engine to be regulated. In the venturi 14, a little downstream of the neck 18 of said venturi, the pipe 12 opens. Upstream of the venturi 14 is the air inlet 19. The cross section of this air inlet is conical.

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 controlled by a rotary valve 20 mounted on journals 21-22 rotating in a box 23.

   The valve 20 is provided with two openings 24-25 and two solid parts 24a-25a. The opening 25 is capable of gradually coming to coincide with the air inlet 19 when the valve 20 turns in the direction of the arrow f, thus gradually opening this air inlet until it is completely. cleared. the openings 24-25 being as large as the air inlet 19. On the journal 22 of the valve 20 is fixed an arm 26 which is connected by links 27 to the rod 28 of a piston 29 capable of move in a cylinder 30.

   This cylinder communicates via a duct 31 with the interior of the carburizing device a, at a point situated between the valve 17 and the valve 20, preferably between the valve 17 and the neck 18 and more particularly at a point 38 situated in the divergent part 16 of the ventur. 14. A spring 33 surrounding the journal 22 and fixed at one of its ends to the box 23 and at its other end to the burs 26 tends to force the piston 29 4 to move towards the lower part of the cylinder 30 and to bring the valve 20 to close the air inlet 19, the solid part 25a coinciding with this air inlet.



   When the butterfly 17 is closed, as is shown in fig. 2, there is no depression in the venturi 14, no suction being exerted on the opening of the tube 12 in said venturi; there is no vacuum transmitted to cylinder 30 and spring Ci; closes the air inlet valve 20.



   When, for normal operation, the @pillon has been opened, the motor creates a vacuum in 1 air inlet 13 and the venturi 14, vacuum which is transmitted to the valve

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 air inlet 20. This depression acts on 3, 'tube 12 and all along the latter to the venturi 3. Air is sucked into this venturi and, passing through the neck 6 of the latter , it sucks liquid fuel by raising it through conduits 7 and 8, the chamber 9 and the tube 10 from the tank 1 e producing a very rich fuel mixture which is transported through the tube 12 to the vent. turi 14.

   The same depression also acts through the conduit 31 inside the cylinder 30 and, consequently, on the piston
29 which compresses the spring 33 and opens the air valve 20.



   If, in normal operation, the engine is subjected to a load such as to force it to reduce speed, the valve 17 being however kept open, the vacuum in the intake pipe 13 and the venturi 14 will decrease; the carburetion is then influenced simultaneously in the device a and in the device b and does not remain at its optimum value; but the variation of suction then comes into play to regulate the air intake; the depression being less than when the engine was running at full speed, the spring 33, calibrated accordingly, will move the piston 29 by a certain amount and will partially close the air inlet valve 20.

   The quantity of air admitted will decrease accordingly If the spring 33 is suitably calibrated) the air will decrease not only absolutely but also in proportion to the decrease in / quantity of rich mixture produced by the device to and allowed in the device b.



   The more the engine speed decreases, the less is the depression in the venturi 14 and consequently the more the spring 33 will lower the piston 29 in its cylinder and will close the valve 20. The regulation will therefore be continuous and, by suitably determining the section / of the piston

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 and the force of the spring, it will be possible to maintain the best value at each speed of rotation of the engine for the admission of rich mixture and air to the device This regulating device not only maintains a correct adjustment whatever the degree of opening of the valve 17, but it is, moreover, particularly effective when the butterfly valve 17 is fully open and the engine is subjected to a variable load.



   The carburetor as shown in fig. 1 to 4 also includes an idling device which co-operates with the normal running device previously described.



   This idle device comprises a venturi tube 34 having a converging portion 35 and a diverging portion 36 and a neck 37 which communicates with a tube 38 which extends to the vicinity of the bottom of the liquid fuel tank 1. A pipe 39 communicates the vehturi 34 with a duct 40 which opens into the duct 13 downstream of the adjustment butterfly 17. #The section of this duct is adjusted by the needle 41 provided with a longitudinal passage 42 and a transverse passage 43.



   The passage 43 maintains a permanent communication between the pipe 39 and the suction pipe 13 while the passage 42 ensures a constant communication between the atmospheric air and said pipe.



   The suction exerted by the motor is transmitted by the duct 40 to the passages 42 and 43 and to the pipe 39 until the vent 34. Air is sucked into this venturi which has the effect of sucking liquid fuel from the venturi. tank 1; this fuel is mixed with the air which enters the venturi and forms a very rich fuel mixture which is transported to the pipe

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 intake 13 through pipe 39. At this point / -the rich mixture receives an addition of air through passage 42 so! make the slowdown fuel mixture
When the engine is running slowly and is not under load, the throttle 17 is closed and the engine is supplied only by the pipe 39 by means of the venturi 34.

   When it rotates at its normal speed, the valve 17 is wide open and the motor is supplied only by the pipe 32 by means of the venturi 3 because the passage 45 is very small. The vacuum is at this moment very low in the venturi 14 and the speed of the air in the venturi 34 is consequently too low to remove the liquid from the reservoir. It may however happen that, for a certain position of the throttle 17 and for a certain engine speed, the latter is supplied both by the normal running device and by the idling device, the effect of the air regulating valve 20 reacting on these two supply devices.



   It should be said that the valve 20 and its actuating device also serve to ensure good resumption of the engine for the passage from idle to normal operation when, as has been said above, the duct 31 is , according to the invention, of a sufficiently small diameter.

   The pressure drop in this duct then acts in such a way as to slow down the movement of the piston 29 and thus prevent the valve 20 from opening too quickly when the throttle 17 is suddenly opened to make the recovery. If valve 20 were to open too quickly, the vacuum would force too much air into the intake line before valve 3 was activated again and the air column.

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 and fuel mixture in tube 12 is put into motion.



  By slowing down the opening of the valve 20 during the sudden opening of the butterfly 17, the suction transmitted to the venturi 14 first acts on the tube 12, on the venturi 3 and at the same time on the pipe 31 but, as the vacuum is transmitted slowly to the piston 29, the air regulating valve 20 also opens gently and the air is admitted through the air inlet 19 at the right time in correct progressive proportion with respect to the quantity of rich mixture which enters the venturi 14 through the pipe 12.



   The recoveries are also facilitated by the liquid fuel accumulated in the recess which surrounds the neck d. venturi 3 and which is located in duct 7. When the suction effect of the venturi 3 ceases, the fuel which fills chamber 9 partially flows into the recess just alluded to in the lower part of conduit 7 and remains there. When the venturi 3 is again put into action, it first of all sucks the fuel in the recess and in the duct 7 thus causing a slight excess of fuel which adds to the primary air thus enriching the fuel mixture which facilitates recovery.



   To ensure better operation in the progressive action of the air valve 20, the opening 25 may be in the shape of a V, sawtooth or any other shape providing a gradual opening or closing. of the air inlet during the opening or closing movements of this valve.



   In the variant shown in FIG. 6, the piston 29, instead of being actuated on one of its faces by the suction and, on the other hand, by a piston, is actuated at its upper part by the vacuum which prevails downstream of the valve.

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 valve 17 via conduit 31 and on its other face by the vacuum created when opening a conduit 31b which opens at 31a into the neck 18 of the venturi. The piston is thus actuated by a differential depression.

   When the valve 17 is closed and the carburettor operates by means of the idling device (identical to that of the carburettor in fig. 2 but not shown and which opens at 40 into the intake pipe 13), the vacuum in downstream of 17 draws the piston 29 upwards, thus closing the air inlet valve 20 (shown here as a butterfly). When the valve 17 is open, the vacuum at 31b being greater than that at 31, draws the piston downwards and opens the air valve 20.

   If, with valve 17 almost or fully open, the engine tends to vary speed and therefore the pressure in the carburetor changes, the difference between the depressions at 31 and 31b will vary similarly and the piston will be displaced by the new difference in depression until the di piston having actuated the air inlet adjustment device, the depression in the carburetor returns to its normal value and thus the balance of the adjustment system air is established again,
It can be seen that a carburetor in accordance with the invention makes it possible to obtain a much greater flexibility for the engine and especially allows it to descend to a very low speed of rotation lower than that which currently known carburetors allow. ,

   
In fact, at low speed of rotation, the torque of an engine supplied by a carburetor according to the invention has been found to be much greater than that of an ordinary engine supplied by the best carburettors currently.

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 put on the market. This results from the fact that the adjustment of the air intake in the carburettor (primary carburizing device and secondary carburizing device) prevents the fuel mixture from becoming too lean in fuel when .. at reduced speed, the control valve. setting is wide open. As a result, the motor cannot be suffocated by excess air and continues to be in optimum supply conditions.

Claims

CLAIMS 1. In a direct feed fuel lift carburetor, the combination of an intake line, a fuel tank located at a level below this line, a primary venturi located above the level fuel in the tank and in the immediate vicinity of the latter, a pipe connecting the venturi neck to a point located slightly above the bottom of the tank, a secondary venturi in the intake pipe, a adjusting butterfly valve placed in front of this secondary venturi to adjust the admission of the fuel mixture to the engine, a pipe connecting the primary venturi to a point located slightly downstream from the neck of the secondary venturi,

an air adjustment valve regulating the air intake in the secondary venturi and acting on the air intake in the primary venturi and means dependent on the depression which prevails in the intake pipe between the butterfly valve regulating valve and the air regulating valve and which act to close the air regulating valve when said vacuum decreases and to open it when it increases, .substance as described.

2. In a direct fuel lift carburetor the combination of an intake line, a liquid fuel tank located at a level below this line, a primary venturi placed above the level. fuel in the tank and in the immediate vicinity of this tank, a pipe connecting the neck of the venturi to a point situated a little above the bottom of the tank, a <Desc / Clms Page number 12> adjusting butterfly valve arranged downstream of this secondary venturi to adjust the admission of the fuel mixture to the engine, a pipe connecting the primary venturi to a point located downstream from the neck of the secondary venturi, a re-valve - sliding the air inlet into the secondary venturi and acting on the air inlet in the primary venturi,

of a piston movable in a cylinder, of a communication connecting one of the faces of this piston with a point situated between the adjusting butterfly and the air inlet valve, of a spring tending to open the valve air inlet and a connection between said piston and #the air re-entry valve, the movement of the piston under the influence of the. EMI12.1 n66 01-d..I5U! ' the. bir inlet valve do 111111.- to close when the vacuum decreases and vice versa, in substance as described and shown in the drawing.

3. In a direct-fed fuel lift carburetor, the combination of an intake line, a combustible liquid tank located lower than the intake line, a primary venturi located above the level of the fuel in the tank and close to this tank, a pipe connecting the neck of this venturi to a point located slightly above the bottom of the tank, a second venturi in the intake pipe, a regulating butterfly located downstream of this second venturi / regulating the admission of the fuel mixture to the engine, a pipe connecting the primary venturi to a point located slightly downstream of the throat the secondary venturi, an air re-entry valve regulating the air intake in the secondary venturi and reacting on the air intake in the primary venturi,

of a piston movable in a cy- EMI12.2 lindre. of a duct connecting one face of said piston to a <Desc / Clms Page number 13> point located between the control butterfly and the air inlet valve, a spring tending to open the air inlet valve and a connection between said piston and said valve air inlet ,,. the movements of the piston under the influence of the depression mentioned above and of said spring having the effect of moving the air inlet valve towards its closed position when the depression decreases and vice versa. and means for adjust the section of the passage connecting the oylinder with the engine inlet pipe, substantially as described.

4. In a direct-fed fuel lift carburettor, the combination of an inlet pipe of a fuel tank situated at a level below this pipe, 'a primary venturi disposed above the level of the fuel. in and near the tank). of a duct connecting the venturi neck to a point located slightly above the bottom of the tank? a secondary venturi in the intake pipe a regulating butterfly valve located downstream of this secondary venturi to adjust the admission of the fuel mixture to the engine, a pipe connecting the venturi primary at a point located slightly downstream from the neck of the secondary venturi of an air inlet valve regulating the air intake in the secondary venturi and reacting on the air intake in the primary venturi,

a second primary venturi located in the same way as the first venturi and connected to the bottom of the tank, a pipe connecting this second primary venturi to the engine inlet at a point located downstream of the control throttle, means for eating air from the fuel mea nge supplied by this second primary venturi, from a piston movable in a <Desc / Clms Page number 14> cylinder, a duct connecting one of the faces of said piston to a point located between the adjusting butterfly valve and the return air valve, a spring tending to open the return air valve and a connection between said piston and said air inlet valve,

the movements of the piston under the influence of the above-mentioned vacuum and of the spring having the effect of moving the re-entry valve to its closed position when the vacuum decreases and vice versa, in substance as described , 5. In a direct feed fuel lift carburetor the combination of an inlet line, an atr-tight fuel tank located below the inlet line, a primary venturi - re placed above the level of the liquid in the tank and close to the latter, with a pipe connecting the neck of this vent to a point located slightly above the bottom of the tank,

a secondary venturi in the intake pipe. an adjusting butterfly valve downstream of said secondary venturi to adjust the admission of the carbureted mixture to the engine, a pipe connecting the primary venturi to a light point - downstream of the throat of the secondary venturi, of an air inlet valve regulating the air admission into the primary venturi, of a second primary venturi located in the same way as the first and connected to the bottom of the tank, a pipe connecting the second primary venturi to the engine intake pipe at a point located downstream of the control throttle, means for mixing air with the fuel mixture supplied by the second primary venturi,

communication between the neck of the second vauri and the interior of the reservoir <Desc / Clms Page number 15> above the fuel level of a tube opening at one end to the atmosphere and at the other end near the bottom of the tank and @ means depending on the negative pressure which prevails in the inlet pipe between the valve and the air inlet valve and acting to close the air inlet valve when said vacuum decreases and vice versa, substantially as described.

6 '. In a direct fuel lift fuel carburetor, the combination of an intake line, an airtight fuel tank located at a level lower than said intake line, a primary venturi located above the level of the fuel in the tank and in the immediate vicinity of the latter, a duct connecting the neck of the venturi to a point located slightly above the bottom of the tank of a venturi secondary arranged in the intake pipe? a throttle valve placed downstream of said secondary venturi to regulate the admission of the fuel mixture to the engine * of a pipe connecting the primary venturi to a point located slightly downstream from the neck of the secondary venturi,

an air inlet valve regulating the admission of air to the secondary venturi and reacting to the admission of air to the primary venturi / the second primary venturi @ killed of the in the same way as the first and connected to the bottom of the tank, by a pipe connecting this second primary venturi to the engine inlet pipe at a point located downstream of the control valve, means for mixing air to the fuel mixture supplied by the second primary venturi of a duct communicating the neck of said second venturi with the interior of the tank above the fuel level, from a pipe opening at one end to the atmosphere and at the other end near the bottom of the tank,

a safety valve opening to the atmosphere and means dependent on repression in the <Desc / Clms Page number 16> intake pipe between the control throttle and the air inlet valve and acting to close the air inlet valve when said vacuum decreases and vice versa, substantially as described.

7. In a fuel lift carburetor at EMI16.1 I; pzè.ion direct, the combination of an inlet line, an airtight fuel tank and EMI16.2 located at a lower level z the said admitted = 3, with a primary vent, located above the fuel level in the tank and in the vicinity of the latter, with a pipe connecting the neck of the venturi to a point located slightly at - EMI16.3 above du'réservoir.d'un secondary venturi in the intake pipe, of a throttle valve downstream of this secondary venturi to adjust the quantity of fuel mixture ad-. put in the motor:

r, a unit connecting the primary venturi to a point located slightly downstream from the neck of the secondary venturi, an air inlet valve regulating the air intake in the secondary venturi 'and reacting on the 'air intake in the primary venturi' a primary venturi arranged in the same way as the first and connected to the bottom of the tank .. by a pipe connecting this second primary venturi to the engine intake duct in a point located downstream of the adjustment butterfly, deans for mixing air with the fuel mixture supplied by the second primary venturi, of a duct making the neck of this primary venturi communicate with the interior of the fuel tank fuel above the level of EMI16.4 fuel in this tank7;

a tube opening at one end to the atmosphere and at the other end near the bottom of the tank a movable piston in a cylinder duct rc- <Desc / Clms Page number 17> binding one face of said piston to. a point situated between the control flap and the air inlet valve, 4 a spring tending to open the air inlet valve and a connection between the piston and the inlet valve d 'air, the movements of the piston under the influence of the depression mentioned above and of said spring having the effect of moving the air inlet valve to its open position when the depression decreases and vice versa, in substance as described and shown in the drawing.

8, Direct feed fuel lift carburettor in substance as described and shown in the drawing. <Desc / Clms Page number 18>

ABSTRACT The object of the invention is a fuel lifting carburetor with direct supply from a tank far away and below the engine, comprising a primary carburetor & one or two venturis, placed on the tank and feeding directly therein, and which is connected by a pipe to a secondary carburettor placed near the engine provided with a usual adjusting butterfly valve and, in addition, with an additional air inlet regulating valve controlled on the one hand by the vacuum which prevails in the engine intake pipe between the control throttle and said valve and on the other hand by an antagonist spring or by the vacuum prevailing downstream of the control throttle,

the consistency of the fuel load on the Venturi. of the primary oarburatour can be ensured by the enclosure of the tank which one provides with a tube open to the air and plunging until the mowing. and by the creation of a depression in the upper part of the tank