US1763061A - Carburetor for internal-combustion engines - Google Patents

Description

June 10, 1930. F. MONIER,

' CARBURETOR FOR INTERNAL COMBUSTION ENGINES Filed Oct. 31. 1922 7/l/VVF/V 70K 7' L ATfLQEYS Patented 7 June 10, 1930 PATENT -mg;

FRANCIS MONIER, OE NEUILLY-SUR-SEINE, FRANCE CARBURETOB FOB. INTERNAL-COMBUSTION ENGIN ES' Application filed October 31, 1922, Serial No. 598,084, am1 in Trance November 5, 1921.

My invention relates to carburetors where in the feed of the li uid fuel, gasolene for instance, is' produced y the suction of the engine and the flow of air around or past a fuel 5 feed or spray nozzle,

by opening or closing a throttle valve inthe engine suction conduit. In ordinary types of carburetorthis flow of air which-is nil when the valve is closed, increases in propor- 1 tion to the opening, whilst the reduction ofpressure whichacts between the motor and this valve is very great when the valve is closed, and decreases in proportion to the opening, so asto fall to the value of the reduction due to the rate of flow of air when the valve is 'fully open.

If the reduction of pressure, on the contrary, could beincreased in proportion to the opening of the valve, the suction and diffusion of the fuel may then be produced'direct ly by this reduction and a perfect carburationmay be obtained. I i I The object of the present invention is to effect asuctionand feed of the liquid fuel exactly according to the depression produced by the engine itself at all times or with all openings of the throttle or, in other words, in such manner that the suction depressionacting on the spray nozzle shallincrease with the opening of the throttle valve and the fuel feed. due to suction shall vary automatically in proportion to the engine speed. Y According to my present invention the feed of the liquid fuel by suction at any time results from the difference betweentwo depressions exerted by the engine upon the liquid fuelcontained in a suitable fluid-tight tank or reservoir, for example, a float'feed tank, 'said two depressions being produced in the 40 carburetor on the engine side of thebutter-- fly or throttle valve and acting respectively,

one upon a spray nozzle or opening delivering the fuel into the air conduit or Venturi tube and the other acting at any point in said conduit or tube upon the outlet of a pipe connected with the air space above the body of fluid and with a depression effect less than that exerted on the spray nozzle. In this arrangement the amount of fuel drawn in will 0' depend upon the difference between the two the flow being regulated depressions, said difference varying directly path the speed and suction of the engine and mcreasin with the speed.

Fig. 1 1s a vertical section through a carburetor embodying my invention.

Fig. 2 is -a horizontal section through the same taken on line 2-2 of Fig.1.

Flg. 3 is a vertical'section taken through a the diffuser on the line 33 of Fig. 2.

Referring now to a typical construction of 0 apparatus in which my invention may be embodied for practical use and illustrated in Figs. 1, 2, andfi, a diffuser or venturi is shown at 13 having an air tube 11 opening into the same at the pro-selected position, above the spray nozzle by the outlet 11 and connected through p ping, as shown, .with the space above the liquid in the float chamber 1 formed in the casing 52 and having the usual or suitable float 56 for maintaining the level of liq- .70 1nd therein. The Y diverging cone 13 into which 11 opens meets at the smaller end thereof a converging cone 12,.the two cones being securedtogether in any desired manner 1n the carburetor casting or body. The annular passage 14 forming with the body of the carburetor an annular chamber 16, communicates with thebody of liquid in the float chamber by a pipe 5 opening at 8 into the chamber 16 and the feed of'the fuel takes place through the annular passage 14, the fuel being mixed with the air delivered in the usual'way into the lower end of the doubledlifuser or venturi from the chamber 57 supplledwith air through the opening 58. The 35 fuel passes to duct 5 through the guide rod for the float 56, as clearly shown, or may be otherwise supplied'thereto. The lower portron of chamber 16 communicates with the alr passageway by means of ducts 17 to pero mit rapid discharge of accumulated fuel from I this chamber when the ducts are uncovered as described below.

The throttle valve operated by arm 22 or otherwise is adapted to close more or less the opening through which air is delivered to the venturi and may be of any desired form. By preference I use a cone-shaped member 19 mountedv in the valve chamber 57 and movable axially on the element 42 and co-operating with the narrow part of the diffuser cones or venturisto govern the flow under the engine suction. By using this form of valve an increased'or strongerdraft of air may be ucking the fuel. When however the throttle valve is op'n, the depression at 14 is necessarily greater than at 11 because the draft of air is stronger in the restricted part of the venturi than in the diverging part. I do not limit myself however to the particular details of throttle valve shown..

The action in effect results from the fact that when the throttle valve 19 is closed or nearly closed it enters the restricted portion of the Venturi tube or the throat of the suction tube and causes an increased draft of air to pass the spray nozzle formed in some cases by the annular opening 14 located between the reverse cones forming sections of the Venturi tube. This strong draft of air insures by its dynamic effect a greater suction upon a the fuel emerging from the spray nozzle.

.When the throttle valve is open the depression acting at 14 is nevertheless greater than at the depression orifice or opening 11* owing to the fact that the spray n'ozzleis at the re- 1 stricted part of the Venturi tube where the draft or depression is stronger than in the diverging art-where the air outlet 11* is located. 11 previous types of carburetor employing difference of depression to effect the feed of the fuel, the apparatus works imperfectly for slow running motor because a' type of valve of the ordinary construction is employed and when it is closed or nearly closed the depression will be practically the same for the two depression elements, being in effectthe static depression. In this condition of the usual valve no effective dynamic depression or effect exists on the spray nozzle since the draft of air owing to the closure of the throttle, is at such time very small in the suction tube.

The depression in the chamber 16 may be varied by means of a needle valve 44 controlling an air inlet opening 43 which nor- I mally admits a very small portion of outside air for adjusting the relative depressions at 11 and 14.

The closure member 26 is adapted to close .the openings 17 and as indicated for example in Fig. 2, this member is held in elevated position by means of the compression spring 27, shown in Fig. 2, so that the openings 17 are normally closed before the valve 19 reaches closed position. The closure 26' is I formed with vertical transverse openings 29 to permit the passage of air past the closure 26 after the latter has closed the openings 17.

The closure 26 and throttle valve 19 are supported upon a vertical post 42, the closure 26 being slidably-mounted upon an extended shank of the valve member 19. This shank is formed with oppositely extending fingers 23 engaged by the forked ends of the controlling arms 20 which together With the operating arm 22 are mounted upon the transverse rotatable shaft 21. v

It will thus be seen that movement of the arm 22 causes acorresponding movement of the throttle valve 19 and the closure 26.

Inthe operation of the apparatus when the I throttle is wide open, the suction of the motor produces at the outlet 11 positioned in accordance with the principle hereinbefore described, a rapid air flow which produces a.

reduction of pressure in the space above the fluid in the reservoir. The suction of the motor also produces a reduction of pressure at the outlet of the tube 5 and this reduction, owing to the more rapid flow, will be greater than that at the outlet 11 and will act on the fuel enclosed in the reservoir on the surface of which the pre-selected weaker reduction produced by 11 acts. The amount of fuel supplied is then determined by the difference of these two reductions while the valve'is' opened and the motor is running. If now, to reduce thespeed of running the motor, the throttle valve is closed, the motor sucks directly unequally at the outlets 11 and 8, and the difference of the two reductions is very small corresponding to an amount of fuel proportional to the speed of the greatly reduced running. of the motor. For the intermediate positions of the throttle valve the difference of'th'e two reductions will gradually diminish corresponding to a'smaller amount of fuel proportionate to the speed of running of the motor. The extent of the difference of depression is determined by properly selecting the position of the outlet 11 with reference to the fuel outlet to secure the desired proportions of fuel and air desired for a normal running at the various positions of opening of the throttle.

Claims:

1. Ina carburetor for an explosion engine, the combination of a reservoir partly filled with liquid fuel, a pipe through which fuel can be sucked into the engineand mixed with air and formed with zones of greater and less constriction, 'a tube opening at one end heneath the level of the liquid in the reservoir and terminating at the other end in a plu-I rality of openings extending into the more constricted zone of said pipe and spaced longitudinally of said pipe, a second tube opening at one end into the reservoir above into the less constricted zone of said pipe and a throttle valve in the pipe operable outwardly of the openin thereinto of both said tubes, said throttle va ve includin portions movable gradually toward or rom position to v close certam of the opemn s of sald first-' named tube into said inta e pipe as said throttle valve is moved toward closed or open position respectively.

' 2. In a carburetor for an explosion engine,

the combination of a reservoir partly filled with liquid fuel, a pipe through which fuel can be sucked into the engineand mixed with. air and which has portions of greater and less constriction, a fuel inlet chamber formed with upper and lower openings, opening into said pipe at and near the portion of greater constriction respectively, 'a tube opening at one end beneath the level of the liquid in the reservoir and at the other end in said chamher, a throttle valve movable toward or from said openings for producing closed and open throttle conditions respectively, means controlled in conjunction with said throttle for i closing said lower opening as said throttle is moved toward closed position but before closed throttle condition is reached, and for maintaining said openin s closed until said throttle is moved towar open throttle condition and a second tube opening at one end into the reservoir above the level of the liquid and at the other end into the pipe inwardly of the more constricted portion thereof. In testimony whereof I aflix my signature. as y ,FRANGIS MONIER

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