US1624604A - Carburetor - Google Patents

Description

Patented Apr. 12, 1927.

UNI-TED STATES PATENT oFFl'cl-:j

THOMAS W. KINGS, or HARVEY, ILLINOIS, AssIeN'oR 'ro IRA n. miams, or BEAVER DAM, WISCONSIN. y

cARBuREToR.

Applicatonled May 17, 1923. Serial No. 639,521.

The purpose 'of thisl invention is to provide a carburetor for governing, and automatically regulating the supply of fuel to,

internal combustion engines, as requiredv 'under different conditions of operation.

Thus, when an engine, equipped with this carburetor, is started the' carburetor lwill first operate to admit a maximum quantity of fuel in proportion to the air taken by the engine.' As the latter warms up and' is operating more effectively and at a speed producing greater suction, the fuel orifice of the carburetor automatically decreases in area and thus reduces the supply of fuel to what is required for idling speeds; or,' 1f the engine is under load, the carburetor wlll function'to supply the proper mlxture which is normally re 'uired for the most efficient operation of t e engine according to the load carried.

The present invention is further d1st1nguishable from prior art carburetors in that when the engine is subjected to an abnormal load and is consequently slowed down to nearthe starting speed, the fuel supply `o rlfice will again automatically increasein s lze to compensate for the loss of suction.v

It is also the object of the invention to eect a more thorough disintegration` of the fuelthan is possible with carburetors here,- tofore in use, particularly -when the speed of the engine is decreased due to a heavy load.

It is also among the purposes of the'mvention to provide a charge-forming device of simplified construction not requiring the use of a float, but which, nevertheless,oper

ates automatically to' maintain' aA fuellevel in the carburetor, and to provide a carburetor which insures ythe required feed of the fuel from a supply tank at lower level, without the use of pressure-'pumps o r the wellknown vacuum tanks.

The objects of the invention are accom plished by the device shown in the accompanying drawings, in Which:-

Figure take and exhaust mani-folds showingl partly broken away, the carburetor and its' connections to these manifolds. Figure 2 is a sectional view of the c'arburetor on the line 2&2 of Figure- 1.:

Figurev 3 is a sectional view taken on the line 3 3 of Figure 2.

1 is a face viewof the engine in' Figure 4 a detail view of the fuel valve ing the fuel orice ofA the Vdisintegrating Also, when a thorough mechanical device.

disintegration of the fuel isy effected, there is less need for the use of heat in preparing theclxarge of fuel and air for/use in the engine cylinders, 'and consequently a higher volumetric efficiency .lof the engine is' 'as` sured. In carbu'retors now generally in use, the speed of the air past. the fuel orifice does not lncrease 1n proportion to the open- 'ing Aof the throttle. llfith the engine idling,-

and' the 'throttle nearly closed, there is, of course, a very' considerable vacuum in the intake manifold, but it 'is not available for atomizing the fuel because of rbeingcut off from the fuel by the'th'rottle valve. When the throttle is opened to compensate for. increased load or to speed up the engine,

although the vacuum4 in the manifold de'- creases. lThe'speed through the carburetor will increase because what vacuum the' is is available for action in the' carburetor,

b ut after the throttle'is further opened,'the'g 'vacuum in the manifold willcontinue to decreasel but the speed through the carburetor- 'will not increase in proportion to" the' throttle opening, although at this -time it is needed most to atomize Ithe' greater' the increased load. There is also a reduction. inthe pumping action of the engine becaus'eof itslower speed when under'load.

The' degree of' vacuumin the intake manifold is proportional' to the speed of the en quantitygof fuel which is necessary to pull gin'eat 'any given positionof the throttle,

but'the vacuum is least when the throttle is wide openbecause of the free'. inrush of Inthepresent construction', compensation 1s made/'for a reduction'in vacuum 1n the intake manifold by the vusejof a fuel injector, preferably operated by the pressure 'in -the exhaust. manifold. 'The carburetor utilizes a. piston under' the influence of the partial vacuum in the intake manifold, to regulate'the size of the fuel orifice in the' carburetor, and to4 maintain a fuel level in the carburetor. The fuel is, therefore,

looy

drawn A.from the supply tank vdirectly through the carburetor 'by the depression in the intake manifold, and the quantity of the fuel delivered tothe engine is, therefore,in

a measure dependent', upon the vacuum 1nthe intake manifold, except as lmodified by the exhaustfoperated injector and the position of the throttle, which in this case may merely control| the main air supply to the 'intake manifold.. l-When the loadsl are light or the engine .isidly running, the" fuel venturi functions mostly by the partial vacuum -in Vthe intake-manifold, while with heavier loads and wide open .throttles, it functions mostly by the `pressure in the exhaust manifold, through the influence of the jet operated bythe exhaust gas. The pressure ofthe exhaust gases'` increases with `thejopening of the throttle when the loads are heavy. d

The construction as illustrated in the drawingsyin'cludesan intake manifold 1 around which the charge may. circulate and recirculate, hav11g1 a'main air inlet '2 controlled N by'fa, throttle 3, and a fuel and. air 1nlet4.l The-*outlets 5 of Athe intake manifold each lead tothe intake ports of a pair of cylinders.

- The exhaust gasesv from the cylinders are delivered to the exhaust manifold 6 through the openings .7 therein. A conduit 8 leads from the exhaust manifold to the carburetor 9. Conduit 8 terminates at the carburetor vin a, nozzle 10, at the sides of which are air inlets 11.

-With this arrangement, .the pressure in the exhaust manifold 1s utilized to cause a small f stream of the exhaust gases at high velocity to .be delivered by vthe nozzle 10 into the passageway 12 in the carburetor, which passageway is in alinement with a passageway.

13, terminating in the opening 4 to the intake manifold. The jet of theexhaust gasy deliveredl by -nozzle 1,0 Serves to draw air vleast diameter of the venturi.

into the carburetor through the openings 11. Air isl also urged to flow flirough these openings due to the reduction in pressure of the" the carburetor9. The space 22 surroundingv `the'adjacent ends of tubes 12'and 13 forming the' venturi, communicates through a `,transverse passageway 23 and a vertical passageway 24 with a fuel port 25 controlled by valve 26. The stem 27 of this valve at its upper end carries a piston '28 which is .slidablein a cylindrical part 29 of the carburetor body. A spring 30 normally urges Venturi passageway thepiston .to the upper position where Vit l holds valve 26 closed. The chamber 3l be'- low the'piston is subject to the reduced pressurein the intake manifold and the aspira-l tory action of venturi 16, since this space is in' communication withv passageway 23 through the vertical passageway .32 surrounding the stemof .valve 27. The space 33 above the 4piston 28 is in communication with the outer atmosphere' through the port 34.y The positionof theI piston'is,... there- `fore, dependent upon the difference in pres- -sure between the atmosphere pressure above the piston and the partial vacuum below it. Therefore,.when the engine is' infoperatlon,

.valve 26 is lowered,- thus `permitting fuell tov rise inthe passageway 24 past the. -reduced part 35 of the valve stem and into the passageway 23. 4The upper enlargedpart 36 of the valve stem 27 is of thesame diameter" as the vertical passageway. 24, but

is tapered at 37 near the upper end of the passageway 24. This tapered part of the I valve stem forms a second valve, which, when f :valve 26 l1s moved from lts'seat, operatesv as `asa regulatin means for automatically controlling the ow of' fuel and vmaintaining the desired fuel level in passageway 23. The

fuel supply. pipe is connected to the carburetor at, the boss 38, Figure. The fuel passes through the screen 39, ports 40 and 41 before entering the space42 below valvek is maintained' in the transversepassa ew'ay 23 of the carburetor, lor its rate of divery to this passageway is controlled by means of a partial vacuum in the space 22 surrounding the fuel orifice 17 of venturi 16. When there is a reduced pressure in this space, there is a difference in pressure between the upper and lower sides of piston' 28. and the piston is thereby lowered from its normal position against the action of spring 38. The valve 26 is thereby moved from its seat allowing the fuelfto be drawn into the passageway23 and from there through the space 22 surrounding the orifice 17 of In the operation of the "device, afuel level los the venturi and into the venturi-where it becomes disintegrated and mixed with the air entering the carburetor through the openings 11. The rate of iiow of the -fuel and air is dependent upon this difference in pressure, which in turn depends upon the reduced pressure in manifold 1, according to the speed and pumping action of the engine pistons. However, the reduced pressure in the-space 22 surrounding the fuel venturi is also dependent upon the injector action of the exhaust gases passing through the vent-uri from nozzle 10.' The pressure of the exhaust gas is also dependent upon the work performed'or load on the engine. Therefore, when there is a decrease in the vvacuum in manifold 1 due to a slowing up of the engine when under load,this is compensated for by the increased injector .action due to the incl-eas@ pressure in the exhaust manifold..V The tapered part 37 of valve stemaV `28 insures a maximum supply of fuel when .valve 26 is first moved from its seat and gradually 'restricts the flow by more or less closing the upper end of passageway 24 as the piston 28 moves downwardly upon an. increase in suction due to speeding up of the engine. Likewise, in the reverse motion of land chamber 3l under the piston 28. The

piston then rises under the action of springr 30, closing or partly closing valve 26. lVhen the fuel level is again lowered, communication is restored between chamber 31 and the intake manifold, causing the piston 28 to again move downwardly and open the valve.l

Although but one specific embodiment of this invention has been herein shown and described, it will be` understood that numerous details of the constructiion-shown'may be altered or omitted without departing .from

the spiritof this invention as following claims. I r

I claim: i

'1. A charge-forming device of the class described comprising a Venturi tube, an intake manifold with which saidVenturi tube is in communication at one of its ends, a fuel passageway in communication with said Venturi tube near its point of smallest diameter, a. valve for controlling the level 1of fuel in said passageway, andmeans `for op' erating said valve, said means being subdefinedl by ject for operation, to the aspiratory action of said Venturi tube and the level of the liquidin said passageway.

2.l A charge-forming device of the class described comprising a- Venturi tube, an exhaust manifold with which said Venturi tube is in communication at one'of its en'ds, a fuel passageway in communication with said Venturi tube near its point of smallest diameter, a valve for controlling the level of fuel 1n said'passageway, and means for ,operatlngsaid valve,sa1d means being subject for operation, to the aspiratory action of said Venturi tube and the level liquid insaid passageway.

Signed at Chicago this 24th day of February 1923. Y

THOMAS W. RINGS.l

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