US1752959A - Carburetor for internal-combustion engines - Google Patents

Description

" April 1, 1930. N F, M WER r 1,752,959

CARBURETOR FOR INTERNAL COMBUSTION ENGINES Original Filed Oct. 51, 1922 INVENTOR Franc/3 on/ ATTORNEYS.

Patented Apr. 1, 1930 PATENT OFFICE,

I FRANCIS MONIER, NEUILLY-SUR-SEINE, FRANCE CARBURETOR FOR INTERNAL-COMBUSTION ENGINES Original application ,filed October 31, 1922, Serial No. 598,084, and in France November 5, 1921. Divided and this application filed October 15, 1924. Serial No. 743,649.

My present invention relates to carburetors of the character described in my original application for patent filed October 31, 1922, Ser. No. 598,084 of which the present application is a division. In said prior application I have described a carburetor in which the amount of fuel, such as liquid hydrocarbon, fed through a suitable orifice or spray nozzle for mixture with air, depends upon differences of depression or suction at two nozzles or outlets opening into the suction tube or Venturi tube of the carburetor, one of said outlets being the spray nozzle and connectedas usual with the body of the fuel held no at constant level in a suitable sealed container, and the other opening at a different point or positionin the, said suction tube and connected with the closed space above the level of the liquid, said difference of depression or suction at said outlets being affected by or dependentnpon the amount of suction exerted by the engine according to diiferences in the opening of the throttle and said diiference of depression or suction increasing as the air flow or'suction of the engine increases and vice versa.

The present application relates to a special method and means for correcting or adjusting the action of the apparatus according to variations in the nature of the fuel, temperature or hygrometric state of the air or for other varying conditions of operating requiring that the proportions of fuel and air in the mixture supplied by the carburetor through suction of the engine be adjusted.

The object of the invention is also to so construct the apparatus that the correction or adjustment for differences of working conditions, may be made without changing the automatic action of the carburetor under differences ofthe throttle opening and suction of the engine. r

Among other things the invention consists essentially in the provisionfor a carburetor of the type described, of an additional local air supply for the region of maximumdepressifon-in-the carburetor, said additional air supply being regulable. v Another part of the invention consists in 79 the combination withthe depression element which connects with the sealed space above a the liquid fuel of a variable air inlet whereby thedifference of depression existing at the two nozzles or outlets connected respectively with the body offuel and the space above the same may be adjusted.

The accompanying drawings show my in vention as applied to a carburetor of the character hereinbefore set forth and described in my original application, said carburetor being herein shown in one of its preferred forms. The carburetor is shown in central vertical section. v In the'drawing. the suction tube or conduit 1n which suction is produced by the engine and in which the air and fuel are mixed or diifused isshown consisting of two conical or flaring members 12 and 13 whose smaller ends are joined to form a tube whose area of greatest restriction is located at the smaller ends of said cones or funnels. Said suction tube forms a Venturi tube. The lower section or converging cone 12 is properly fitted and secured in the body. 53 of the carburetor in a manner to leave a narrow annular space or outlet 14 between its end and the opposite small end of the cone or funnel 13 which for convenience may be formed as an extension of the carburetor body 53. Said opening 14 constitutes the spray nozzle or outlet through which the fuel is drawn by the suction of the engine into the suction or diifusion tube for mixture with the air sucked into the same by the action of the engine, the latter being suitably connected for that purpose to the upper end of said tube.

The annular opening or spray nozzle 14 is in communication with a chamber 16 which may be formed in the body of the carburetor and closed on one side by the section 13 of the difl'usion or suction tube. The liquid fuel is supplied to said chamber 16 by a suitable tube or duct 5 formed in the body 53 and continued in the float chamber or reservoir 52 as a hollow guide 5 for the float 56. Said guide tube has an opening at 18 near its bottom. The reservoir 52 is closed above the level of the liquid therein and the closed space is connected by the pipe or tube 47 that may also be formed in the carburetor body, with an outlet 46 located in the wall of the suction tube at a point where the depression or suction is less than that existing at the restricted portion of the tube where the spray nozzle or outlet 14 is located.

Differences of the depression at said outlets 46 and 14 exist in amounts differing with differences of suction produced by the engine and according to the extent of opening of the throttle by which air is permitted to be drawn through the suction tube. These differences of depression determine the amount of fuel drawn into the tube for mixture with air.

'This arrangement of the two outlets provides for the automatic action of the carburetor. For adjustment of that action according to the present invent-ion air is introduced in variable amount into the tube which terminatesin' the outlet 46 and this may be conveniently accomplished by the employment of a variable air inlet controlled by a needle or other valve such as indicated at 48.

The correction for nature of fuel and variations of temperature or of hygrometric state of the air or for other varying conditions under. which the carburetor works, is effected according to my present invention by supplying additional air near the region of maximum depression in the suction tube and preferably at a point between the two outlets 14 and 46. This additional air for correction is conveniently furnished from' an annular chamber 49 opening into the suction tube between the spray nozzle and the outlet 46. Said chamber communicates with the atmosphere through a conduit provided with a valve 51 which serves to introduce into the carburetion independently of the automatic device, the correction which momentary circumstances may require.

I do not limit my invention to the particu lar form of the outlets into the suction tube but preferably employ annular chambers with restricted outlets.

The means operating as a throttle valve for controlling suction through the suction tube may be of any desired character. That shown is described and claimed in a copending application filed by me on October 15, 1924, Serial No. 743,648, and comprises the following parts.

A core 19 forminga conical closing element or valve adapted to fit the lower conical sec tion 12 of the suction tube is mounted to be movable axially of the suction tube and 00- operates with the narrow or restricted part of the same to close more or less the passageway and thus control the amount of air which can be drawn through the tube by the suction of the engine. To operate said valve arms 20. mounted on a shaft 21 engage nibs 23 on a lower extension 24 of the-core 19. A, handle or other means 22 operates theshaft. Outlets 17' lead from the annular chamber 16 into the lower cone as shown:

Upon the extension of the core or valve 19 is slidable an annular closing member 25 whose outer surface 26 corresponds to the inner surface of the cone 12 and is adapted to fit into the same and to close the outlets 17. The said closing member 25 is provided with vertical air passages as shown in dotted lines. The member 25 rests upon a spring 27 interposed between thesame and a shoulder carried by the stem of the element 19. The device is so arranged that upon raising the core 19 the said closing member 25 is first brought into contact with the cone 12'so as to close the holes 17, and it is only after the holes are closed that the core 19 or throttle valverfits into. the diffuser, thereby closing the annular orifice or fuel feed outlet or spray nozzle 14; this closing is not complete, for the core 19 is provided with the grooves 28 on its surfaces which allow passage of air.

The valve and the closing member with their operating parts work in the air inlet casing 57 having the usual openings to the atmosphere and suspended from the body 53 of the carburetor. When the valve 19 is closed, that is, when the element 25, 26 closes the holes 17 and the core 19 fits into the diffuser, the air required for the extreme slow speed will enter through the holes 29 and grooves 28, and the annular space 16 becomes filled with carburant. By opening the said valve by lowering the core 19 together with the closing element 25, 26, air will be admitted, but'at the same time the holes 17 are uncovered, and when the air enters through the holes the liquid fuel in the annular space 16 is drawn into the diffuser, thus producing momentarily a richer mixture so that the return to speed is facilitated.

As will be seen, when the valve 19 is closed or nearly closed by entering the restricted Venturi or suction tube, it will cause an increased or stronger draft of air to pass the spray nozzle or annular opening 14. This compensates for the diminution of the effective depression at the spray nozzle due to the diminution of suction when the flow of air through the Venturi tube is nearly shut off, the tendency then being towards a close equalization of the depression effective in sucking the fuel. When however the throttle valve is open, the depression at 14 is necessarily larger than at 46 because the draft of air is stronger in the restricted part of the venturi than in the diverging part.

I do notlimit myself in the present case, however, to the particular construction of throttle valve described as other means might be employed for limiting or restricting the flow of air through the suction tube.

3 What I claim as my invention is:

1. In combination, a carburetor, an intake pipe, a fuel chamber associated with said carburetor and normall closed to the atmosphere, means forpro ucing' points of? greater and less depression in said intake pipe, means for conducting fuel from said chamber to the point of greater depression of said intake pipe, means forming a communicating passage leading from the space above the liquid level in said chamber to a point of less depression in said intake pipe, correcting devices for admittinga small quantity of outside air into said intake pipe between said points of depression for varying the depression therein, and means for adjusting the capacity of said correcting devices.

2. In the combination of a carburetor and an intake pipe wherein said carburetor is provided with a fuel chamber closed to the atmosphere and said intake pipe is provided with a restrictive portion, means for conducting fuel from said chamber to said restricted portion, a tubular passageway connecting the upper portion of said chamber 7 with said intake pipe at a point disposed on the engine side and slight y removed from said restricted portion for subjecting said chamber to the suction and flow of fluid within said intake pipe, an adjustable air vent, and manual means for adjusting said air vent for permitting a fixed amount of outside air to enter said passageway for modifying the effect thereof upon the air space in said chamber and a throttle valve for obstructing the air passage through said intake pipe, said throttle valve being positioned on the air inlet side of the point at which said tubular passageway connects with said intake pipe for producing increased suction in said passageway and chamber on closed throttle conditions.

Signed at Paris, France, this 3rd day of October, A. D. 1924.

FRANCIS MONIER.

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