US1359837A - Cabbtjbeter - Google Patents

Description

F. N. PERCIVAL.

CARBURETER.

APPLICATION FILED 9126.10, 1917.

Patented Nov. 23,1920.

2 SHEETS-SHEET I.

III

lli.; lil

F. N. PERCIVAL. CARBURETER.

APPLICATION FILED DEC. l0. 1917.

1,359,837. I1mmNovi23,1920.

ably connected in practice with a conductor CARBURETER.

specification er Leiters raient.

Patented Nov. 3, lt?.

Application filed Becemcer 19,1917. Serial No. 206,498.

To all whom t may concern.' v

Be it known that l, FRANK N. PunoiVAL, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of l3ennsylvania, have invented certain new and useful improvements in Carbureters, of which the following is a s ieciiication.

lhis invention relates to improvements in carbureters for internal combustion engines, and particularly to a carbureter designed for carbureting kerosene and other comparatively low grade hydrocarbons, the object of the invention being to provide a carbureter whereby the fuel agent will be thoroughly and effectually atomized and commingled with air to form a reliable, efcient and economical fuel mixture.

i further and i portant object of my invention is to provide a novel `form and con-- struction of fuel feed nozzle whereby increased eiiiciency in the supply of fuel to the engine is obtained.

The invention consists of the features of construction, combination and arrangement of parts, hereinafter fully described and claimed, reference being had to the accompanying drawings, in which t Figure l is a view inv elevation, partly in section, of a carbu'reter embodying my invention.

Fig. 2 is a vertical section through the carbureter taken on the line 2 2 of Fig. l.

Fig. 3 is a detail section on line 3--3 of ig. 2.

Fig. fl is a perspective View of the fuel injector or feed nozzle.

F ig. 5 is a detail section on line 5--5 of Fig. l.

Fig. 6 is a perspective View of the air inlet tube.

in carrying my invention into practiceil provide a carbureter comprising a casing l, the upper portion of which is formed to provide a main mixing or commingling chamber 2, and the lower portion of which is formed to provide a heating chamber 3 suitably partitioned or separated from said mixing chamber. The mixing chamber 2 is provided at its top with an outlet 4l through which the fuel mixture passes to the intake of the engine, while the chamber `3 is provided at its lower' end with an inlet 5 suitfor conveying thereto hot exhaust heat and f gases from the engine, whereby said chamber is heated., said heat and gases exhausting from the heating chamber through an outlet 6.

The carbureter is provided. at its base with an air inlet 7 opening horizontally through one side thereof, and this inlet forms the lower horizontal portion of a vapor passage 8 extending through and inclosed by the heating chamber 3 and having an outlet end 9 communicating with the base of the mixing chamberA 2 at the side of the lcarbureter casing opposite the air inlet. rllhe vapor passage 8 extends upwardly and rearwardly from the air inlet to therear of the mixing or commingling chamber on a curved line, preferably on the arc or segment of a circle, in order that the initial mixture of air and vapor passing therethrough will be given a comparatively long, but unobstructed flow course to adapt it to be thoroughly heated in its travel and also caused to have a cross-current or eddying effect, whereby the air and vapor will be more thoroughly commingled.` lt will be understood, of course, that as'the passage 8 is subjected to the heat of the products of combustion from the engine flowing through the chamber 3, thewalls of said passage will be intensely heated with the result of ef;- panding the fluid and promoting atomization of the hydrocarbon and admixture of the air therewith to a highly efficient degree.

Disposed within the horizontal air inlet portion 7 ofthe passage 8 is an air inlet tube l0 of the Venturi type, said tubek l0 having flaring inlet and discharge ends 1l and 12 and a constricted central portion i3. ln practice, the tube l0 is detachably secured in positionby means of a retaining screw le, allowing tubes with diiferent sized bores to be interchangeably used, to regulate the quantity of air and hydrocarbon admitted to 'the vapor passage according to the character of the engine in connection with which the carburetor is used or other conditions to be met. rlhe rear orinnerhalf of the base of this tube l() is'formed with a longitudinally extending slot 15 to permit of the upward passage of a fuel inlet or feed nozzle 16 into the central portion of said. tube, and to adapt the tube to be slidably yinserted and removed without the necessity of removing the nozzle. The nozzle projects upwardly fromthe base of the poring the amount of flow as desired.

tion 7 of the passage 8 and is provided with a longitudinal feed duct 1T having at its upper end a restricted jet orice 17 communi- (ating with a-discharge slot 18. This slot 18 opens laterally through the outer face of the nozzle, and extends horizontally or transversely across the nozzle on its side facing the inlet 11. The slot 18 is V -shaped to provide for the free discharge in extended form of a restricted amount of hydrocarbon from the nozzle, the feed of which hydrocarbon is induced by the suction resulting 'from the inflow of the air through the Venturi tube around the nozzle, a needle valve 19 being 'provided for cutting off the Yfeed of hydrocarbon when required and regulat- The nozzle is beveled or cut away at an outward and rearward angle at each side ofthe slot to form V-shaped or flaring grooves 18 which interseft the slot, said grooves providing additional sharp edges against which the fuel impinges to promote and increase the suction feed pull and atomization of the fuel. A stated, the jet orifice 17 faces toward the inlet end 11 of the air tube 10 on a line coincident with a vertical longitudinal line passing through the center of the tube, or parallel with the direction of flow of the column of air. Hence that portion of the column of air striking the central or vertex portion of the wall of the il-shaped slot 15 will be sharply or abruptly divided into two diverging rearwardly traveling streams, jointly operatingto produce a de pression whereby the fuel is drawn outwardly through the jet orifice and also divided into two corresponding streams. The divided streams of air so produced, together with the fuel streams carried thereby, will also be guided by the beveled or inclined faces 18 and caused to travel rearwardly on diverging lines ACorrespending to tial 'vacuum is induced behind and in the region of the nozzle tending to promote and facilitate the rearward flow of the streams of air and their commingling action when the static pressure in the air tube is reduced on each suction stroke of vthe engine. Furthermore, an important advantage is 0btained by the described form of the slot 18 and the provision of the sharp edges at the angles of intersection of the diverging faces 18 with the central vertex portion of the slot and sides of the nozzle, in that these edges not only exert a cutting action on the fuel, wherebyits at'omization is effected, but break up the streams of air into eddies or *cross currents, whereby a thorough admiX- `tureof'the fuel atomswith the air and distribution of the same more uniformly throughout the mass of air is secured. Also by arranging the nozzle so thatthe jet orifice and atomizing surfaces 'thereof directly face toward the inlet end of the air tube, so vas to be diametrically opposed to and medially in the path of the current of inflowing air, advantage is taken of the force of the velocity of the air, as well as of the reduction of static pressure of the air on the suction strokes of the piston, to secure the positive feed of a proper proportion of the fuel on each suction stroke of the piston and its impingement with sufficient force against the atomizing surfaces of the nozzle to thoroughly atomize the fuel and thereby prepare it for intimate combination with the air to form the explosive mixture. Furthermore, by the division of the fuel into two streams, which respectively preliminarily commingle with the two streams of air flowing around opposite sides of the nozzle, the fuel is more evenly distributed to the air than if it were preliminarily commingled with the stream of air on one side of the nozzle only, and hence when the two fuel-impregnated streams of air combine with a whirling Inotion, as they do, in rear of the nozzle, the fuel is more intimately and thoroughly diffused throughout the mass of air. Hence it will be understood that as the fuel is also preliminarily atomized by the cutting action of the angular faces of the nozzle a more even and a finer division of the fuel atoms throughout the air is obtained, with the result that liability of condensation of the liquid fuel is diminished, a more uniform grade of fuel furnished, and consequently greater flexibility of action of the engine obtained. The hydrocarbon will thus be discharged in an atomized condition from the nozzle into the smallest portion of the Venturi tube and will meet the inflowing eurrent of air, thel mixture thence flowing upwardly through the passage 8 and finally through the outlet 9 of said passage into the main miningV or commingling chamber 2. @n its travel through the passage 8 the oxygenized admiXture thus produced is heated by contact with the walls of the tube, resulting in a more thorough admiXture of the fuel constituents, as will be readily understood.

rlhe hydrocarbon or hydrocarbons to be supplied to the nozzle may be conducted thereto from any suitable source and in any suitable manner. 1n the present instance I have shown reservoirs or chambers 20 and 21 suitably provided upon the carburetor casing to respectively contain gasolene as a starting fuel and kerosene or other low grade hydrocarbon as a working fuel. rhese chambers are provided at their lower ends with inlets 22 and 23 for connection with i feed pipes 24: and 25 leading from the source 1,359gss7 of supply of the hydrocarbons, and said inlets are controlled by needle valves 26 and 27v governed by floats 28 and 29 arranged within the said chambers 20 and 21, whereby a predetermined quantity of hydrocarbon will be maintained in each chamber. rllhe chambers 20 and 2l are in communication through feed passages 30 and 81, governed by controlling needle valves 32 and 33, with the bore or passage 17 ofthe nozzle 16,

whereby the feed of the two hydrocarbons to the nozzle may be separately or conjointly controlled.

rlhe upper or outlet end 9 of the vapor passage 8 is of conical or tapered form, as shown, and arranged to operate therein is a similar shaped spreader and retarder 34 suitably connected to the lower end of a sliding or reciprocating rod 35, extending at its lower end outwardly through the top of the casing '1 and operatively connected with one arm of an actuating lever whereby the spreader 34 is adapted 'to be periodically reciprocated. Yrl`he other arm of the lever 8G is arranged in the path of cam 37, adjustably mounted, by means of a setscrew 88 to vary its time period of action7 upon one end of a valve stem 89 extending across the fuel outlet 4, the other end of said stem being provided with a crank arm 40 or the like for connection with some suitable part of the engine mechanism, whereby in the operaticai of the engine the lever will be periodically moved in one direction to elevate the spreader 84 against theV resistance of a spring 41 whereby, during the intervals of Operation of the cam, the spreader will be lowered or depressed. Mounted upon the valve stem 39 within the outlet 4 is a. throttle valve 42,*governing the feed of the fuel from the mixing chamber 2 kto the inlet of the engine, said valve being opened upon the elevation of the spreader and closed upon the depression thereof or vice versa. T he function of the spreader 34, which is of slightly less diameter than the minimum diameter of the tapered outlet 9 of the passage 8, is to reduce the area of said outlet and provide constricted annular channel for the flow of the fuel vapor into the chamber 2 and to act as a baiile to force the fuel vapor into contact with the walls of the chamber 8, whereby the fuel vapor will be more intensely heated. rlChe spreader itself also serves as a heating surface in this connection. lnthe operation of the engine, as stated, the conical spreader is reciprocated and on the opening movement of the valve the spreader is raised in the flaring outlet 9 to gradually increase the area of the constricted channel, and upon the closing of the valve the spreader is depressed to gradually restrict the area of the channel, or vice versa, thus regulating the feed in accordance with the working action of the engine and insuring the heating and preliminary commingling of the air and vapor to a high degree before the final conformation of the fuel charge in the mixing or commingling chamber.

The fueloutlet 4 is disposed centrally at a point between the outlet 9 of the tube and has' an auxiliary airinlet 43 disposed at the opposite side of the casing from said outlet y9 and communicating with thev base of the mixing chamber 2. rI'Shis auxiliary' air inlet is shown in the form of atube feed within a threaded opening in the casing and provided with a seat 44 .adapted to'be engaged by an auxiliary air valve4, said valve being adapted to open under a predetermined suction force of the engine piston. The valve is slidably mounted upon a guide rod 46 carried by a threaded stem of largerdiameter than the'rod to form a "shoulder 48, 4said, stem being adjustably mounted in the top of the casing and pro vided with a milled head 49 whereby may be adjusted to vary the tension of a valve controlling spring 50. This spring 50 is disposed between the valve and the shoulder 48, and normally holds the valve closed l except when the suction action of the piston is greater than the closing force of the spring, whereupon the valve will be opened toa greater or less extentV to admit more or less air to the interior of the chamber 2. jam nut 51 is provided for securing the valve stem in adjusted position. The tube 43 may be connectedin practice with any source of supply of air, preferably heated, air. 1t will thusbeA understood that when the engine is working at high speed auxiliary charges of air will automatically drawn into the mixing chamber 2 for admixture with the carbureted air feeding into the chamber through the passage 8, forming a suitably diluted charge `rmixture-which is drawn through theoutlet4 into the engine cylinder.r A port 52 communicates with the mixing chamber through which steam or other moisture may be. admitted when it is desired to more thoroughly oxygenate the mixture.

By the provision of a carbureter'constructed as above described it will be evident that the thorough atomization of kerosene or other like low grade hydrocarbon fuel may be effected, and this atomized fuel preliminarily combined' with air in such a manner as to thoroughly commingle therewith, and lthat the atomized fuel and air thus commingled will be conducted through a heat passage and heated to such a degree as to secure a higher degree of volatilization of the hydrocarbons a-nd more thorough and intimate mixture of air therewith, the thorough intimate combination of the constituents being additionally promoted by the action of the spreader and agitator 34. As a result, a preliminarily ,carbureted charge of airwill be drawn into Aa heated vor commingling chamber for passage to the motor, which maybe .diluted oradmixed therein with an additional supply of air to vary the Vquality .of the mixture as occasion may require. Kerosene or other lowgrade Vfuel may therefore be used in a reliable andl eective manner and in such a wayas to secure economy in the use thereof. It will, of course, be understood that while the device is primarily designedfor the use of kerosene as a working fuel, it maybeemployed lfor utilizing other Ycomparatively low grade hydrocarbon fuels or mixtures of high and low grade hydrocarbon fuels with advantage.V

Having thus Yfully described my invention,.l claim: i

l. The combination with a carbureter including a casing having an air passage therein, said passage being restricted intermediate the intake and discharge ends thereof, of a fuel inlet Vnozzle extending radially within the restricted portion of the passage and Vhavingits discharge outlet directly facing the intake end of the passagel and directly opposed to and disposed medially in the path of the current of the inflowing air,

the opposite'sides of the'nozzle adjacent to the discharge outlet having beveled surfaces diverging from said outlet in the direction of the course of flow of the air.

2. in a carbureter, a casing having an air and fuel inlet, a Venturi tube disposed in said inlet, and a fuelV injection nozzle extending upwardly into said tube and having a jet orifice directly facing the-entrance end of the tube and directly opposed to and arranged medially in the path of the inflowing air, said nozzle also having beveled surfaces at opposite sidesof said orifice diverging in the direction offlow of-the air, said Venturi tube being removable from said air and fuel inlet independently of and without disturbing said nozzle.

3. AIna carbureter, a casing having an air inlet,and a fuel injection nozzle extending upwardly into the air inlet at a point between its entrance and discharge portions, said nozzle being provided in its side. facing the entrance portion of the inlet with a transverse slot the walls of which diverge from a central point rearwardly in the direction of flow of the incoming air, and said nozzle having a jet outlet opening into said l-,eisagaa'r diverge Vfrom a central point rearwardlyin the direction of fiow of the incoming air, and said nozzle having a jet outlet opening into said slot at the angle of intersection of said diverging walls.

5. ln a carbureter, a casing having an air and fuell inlet, a Venturi tube disposed in said inlet, and a fuel injection nozzle eX- tending upwardly into said tube, said nozzle having a jet orifice opening through the .side of the nozzle facing the entrance of the air and fuel inlet and directly opposed to and medially in the path of the inflowing air, and said nozzle having beveled surfacesfat opposite sides of said orifice diverging in the direction of flow of the air.

6. In a carbureter, a casing having an air and fuel inlet, a Venturi tube disposed in said inlet, and a fuel injection nozzle eX- tending into the contracted portion of said tube, said nozzle being provided with a jet outlet and a horizontal, transverse J -shaped discharge outlet formed in its side facing the inlet end of said tube and with the central portion of which said jet outlet communicates, said slot having its lateral extremities beveled or inclined rearwardly from said jet outlet on diverging lines.

'7. In carbureter, a casing having an air and fuel inlet, and a fuel discharge nozzle extending into said inlet, said nozzle being` provided with a jet voutlet and a discharge slot, said slot extending transversely across the nozzle at one side thereof and communieating intermediately with the jet outlet, and having its lateral extremities beveledV or sloping on diverging lines toward theropposite side face of the nozzle. saidslot being substantially V-shaped, whereby ede surfaces are formed to break up and atomize the flowing particles of fuel.

In testimony whereof affix my signature in the presence of two witnesses.

FRANK NATHANIEL PERCU/AL.

Witnesses WILLrAM H. SAVERY, MARY P. HALPIN.

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