US3592449A

US3592449A - Fuel-controlling device

Info

Publication number: US3592449A
Application number: US750175A
Authority: US
Inventors: Kirrillos B Elgohary
Original assignee: ENERGY TRANSMISSION CORP
Current assignee: ENERGY TRANSMISSION CORP
Priority date: 1968-08-05
Filing date: 1968-08-05
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13

Abstract

An air valve is disposed in the air flowing through a carburetor to the intake manifold of an internal combustion engine. A fuel valve controls the fuel flow to a mixing chamber which produces a suspension of fuel particles which are entrained in the airflow. The air valve is operably connected to the fuel valve through the mixing chamber.

Description

United States Patent [72] Inventor Klrrillos ILElgohnry 1,376,707 /1921 Leahy et a1. 261/44 Pittsburglnla. 1,440,940 1/1923 Smith etal... 26l/D1G. 18 [21] Appl. No. 750,175 1,573,065 2/1926 Hess 261/44 [22] Filed Aug-5,1968 1,595,315 8/1926 Rayfieldm 261/44 [45] Patented July 13,1971 1,789,564 1/1931 Rayfield 261/D1G. 18 [73] Assignee Energy Transmission Corp. 1,792,495 2/1931 Heath 261/50(.1) 1,927,090 9/1933 Hess 261/44 2,614,581 10/1952 Russell 261/50(.l)X [54] FUEICONTROLUNG DEVICE 2,635,625 4/1953 Moseley et a1 261/D1G. 50 CI in 70 I F 2,757,914 8/1956 Ball 261/D1G. 50 3,127,453 3/1964 Sarto 26l/36(.1) [52] [1.8. CI 261/36, 3,275,307 9/1966 Robechaud 261/36(.1) I. cl ggzffggg Primary Examiner-Tim R. Miles n. 0' sun]! 0 14:23:33; Nelson 13. Kimmelman and Maleson, Kimmelman 50.1, 36.1, D16. 18, DIG. 50

[56] Rdenncacmd ABSTRACT: An air valve is disposed in the air flowing UNITED STATES PATENTS through a carburetor to the intake manifold of an internal 1,145,172 6/1915 Speed 261/D1G. 18 combustion engine. A fuel valve controls the fuel flow to :1 1,234,227 7/1917 Schmid et a1. 261/44 X mixing chamber which produces a suspension of fuel particles 1,293,348 2/1919 Costa 261/50 (.1) which are entrained in the airflow. The air valve is operably 1,361,529 12/1920 Marr 261/50 (.1 connected to the fuel valve through the mixing chamber.

j T I51: 2 f2 70 72 2*20 34 37 d K2012. b

0. 62b 6.. 5;\ s 5 47 w PATENTED JUL 1 319m SHEU 1 BF PATENTEDJULISIQTI 3,592 449 sum 3 or 4 ,4 TmzA/E 5 FUEL-CONTROLLING DEVICE BACKGROUND OF THE INVENTION l. Field of the Invention This invention pertains to the field of carburetors for an innal combustion engine in which the airflow into the intake nifold is used to control the flow of fuel to a mixing amber. 2. Prior Art t is well known that an internal combustion engine provides ximum power output when the airflow into the intake nifold is at maximum and there is a correct proportion of l to air. At any running condition of the engine the ultimate ver is decreased if the airflow is less than that demanded by engine. Iarburetors have been used which include air valves for sing the airflow and controlling a fuel valve for metering amount of gas flow into the fuel-air mixing chamber. In the ting chamber air is mixed with fuel to provide a suspension I'uel particles which are entrained into the airflow and then a the intake manifold of the engine. In such prior carbures the air valve has been mechanically connected to the fuel tering valve by rigid rods which were journaled in apertures med in the carburetor housing. When the power or sped of engine changed, these rods moved within the journal and re has developed frictional impairment of free axial movent of the rods thereby hampering the correct free response the gas valve to airflow. On the other hand if the journals re enlarged to minimize friction, fuel in the form of vapor l fuel particles would escape through the enlarged journals m the float chamber to the mixing chamber. This escaping I would bypass the fuel-metering pin and seat which con- Is the air-fuel ratio thereby varying the ratio from a desired ue. mother problem with prior carburetors has been in providproper damping of the air valve. Without damping, upon .nge in engine demand for air the air valve would bounce or illate above and below the stable or balance position for a stantial period of time which resulted in inefficient opera- I. It has been known to use a damper plate immersed within fuel as the damping medium in order to quickly damp out h oscillation. However, if the damping factor is too high, long a period of time may be required before the balance ition is reached. This will increase the lag of time between :ping on or off the accelerator and the response by the ena to increase or decrease power. Such time lag has an adse effect on the performance of the automobile and in the :ty of the operation. Accordingly, prior carburetors have a lot to be desired in providing an optimum damping facwhere the stable position is reached in as short a period of e as possible.

BRIEF OF SUMMARY OF THE INVENTION 1 accordance with the invention there is provided a carbur for an internal combustion engine having a housing with air intake opening and an output opening. Air flows from intake opening to the output opening. Fuel and air are ed in a mixing chamber which produces a suspension of ticles of fuel in air which are entrained in the airflow. A l valve communicates with a fuel source and is operable to trol the flow of fuel to the mixing chamber. An air valve is iosed in the airflow and is movable in accordance with the low from the intake to the output opening. The air valve is rably connected to the fuel valve through a coupling which ses through the mixing chamber. In this manner there is ided the undesirable friction forces of connectors jour- :d in the carburetor housing.

urther in accordance with the invention the carburetor inies a damper member disposed within a damper housing. a damper member is operably coupled to the fuel valve. 1] flow between the damper housing and the source of fuel electively varied to provide a variable damping factor. In

manner an optimum damping factor may be achieved.

BRIEF DESCRIPTION OF THE DRA. 'IN GS FIG. I is a sectional view of a carburetor of the present inventive concept taken along the section line 1-1 of FIG. 2.

FIG. 2 is a sectional view of the carburetor of FIG. I taken along the section line 2-2 of FIG. I.

FIG. 3 is a sectional view ofthe portion of the carburetor of FIG. I taken along section line 3-3 of FIG. I.

FIG. 3A is a modification of the invention of FIG. I in which a swirl action is produced.

FIGS. 4 and 5 is an exploded perspective view of the air valve, fuel metering and damping system of FIG. 1.

FIG. 6 is a further modification of FIG. I in which a floatless chamber is used.

DETAILED DESCRIPTION OF THE DRAWINGS FIGS. 1-3 show a hollow carburetor housing indicated generally by numeral 10 having an air intake opening 11 and a second mixing chamber 12 which is in communication with a conventional intake manifold (not shown) of an internal com bustion engine.

As the engine operates it will produce suction at chamber 12 and therefore air flows into the air intake 11 past a conven tional choke valve [4 through chamber 12 and into the intake manifold. An air valve I5 is disposed in the airflow within chamber I2 and as the engine demands more air the air valve senses the weight rate of airflow and moves upwardly. A portion of the airflow passes through the inner opening of valve 15 and the remainder passes between valve I5 and the inner wall of chamber 12.

VALVE I5ROD 30--PIN 34 In the static rest position the annular body 16 of air valve I5 is supported by a valve seat 17 which is adjustably secured by a lock screw to a hollow stem 20 having an enlarged ringshaped bottom portion 204. The bottom portion 200 is engaged in an annular shoulder 2| of housing 10 formed at the upper edge of chamber 22 containing fuel.

Air valve IS includes a spider defined by four straight verti cal ribs 15a-d extending inwardly from body [6 with the ribs meeting to form a hollow cylinder 1Se. Secured within cylinder 15: is a sleeve 24 having a washer-shaped upper member 240 and a lower portion which may be peened under cylinder 15c. Upper member 240 has four openings in which there are secured respectively the lower ends of rods 25a-d. The upper ends of rods 25a-d are secured within openings 28a-d. The upper ends of rods 2Sa-d are secured within openings 28a-d respectively of a pin holder 28. Rods 25a-d may be secured to the respective openings of member 240 and holder 28 by welding, as for example. A center opening 28c of pin holder 28 threadedly engages the upper end of a pin rod 30 which extends through without touching a tube 32 and the inner chambers of hollow stem 20. Rod 30 at its lower end, is secured in an opening in an upper end ofa fuel valve metering pin 34, the lower end of which is connected to a damper plate 36. Accordingly, metering pin 34 and damper plate 36 move upwardly and downwardly as air valve I5 is urged upwardly and downwardly respectively by the airflow through chamber 12.

Metering pin 34 is tapered so that as it travels in an upward direction the annular clearing between pin 34 and a valve seat 37 threadedly engaged within hollow stem 20, increases in area. In this manner a greater amount of fuel within chamber 22 is allowed to flow into a first mixing chamber 39 formed within stem 20 adjacent to the upper end thereof.

The supply of air for mixing chamber 39 is taken from below valve seat 17 by way of air passages 40. Tube 32 extends upwardly from chamber 39 into chamber 12. In order to provide suction in chamber 3!, a pressure difference is produced between the upper and lower sides of air valve I5 which is effective to suck up the mixture of a suspension of fuel particles in the air through tube 32. Accordingly, the mixture is directed out of the upper and of the tube and into the air which flows through second mixing chamber 12 outside of tube 32.

It will now be understood that the only mechanical coupling between air valve 15 and metering pin 34 includes a support ing structure of rods ad and holder 28 and an elongated member or rod 30, Rod 30 extends downwardly through tube 32 and through hollow stem 20 which includes first mixing chamber 39. Accordingly, there is avoided the use of friction producing members which have in the prior art heenjournaled in apertures in the carburetor housing for coupling the air valve with the metering pin and the damper plate. Alternatively, there is eliminated the amount of fuel which would escape through enlarged journals from the fuel chamber to the mixing chamber bypassing the metering device.

AIR VALVE 15 Inner Opening Annular body l6 has an inner wall 160 which forms an inner central opening of air valve 15. Wall 1611 defines a downwardly and outwardly rounded surfacev An annular beveled surface .70 of seat 17 smoothly mates with inner wall I60 when valve I5 is in the static rest position. As air valvc l5 moves upwardly, a straight-through smooth streamlined profile for airflow is provided through the inner opening of valve 15 and between seat 17 and valve 15, This streamlined profile is particularly important when valve 15 and seal 17 are substantially close to each other forming a sharp corner to air flow as for example during idle and at low cruise speeds. A sharp corner or nonstreamline profile provides substantially more resistance to airflow than a smooth streamline profile Thus the major portion of air flowing through the inner open ing flow with less resistance as compared with a nonstreamline profile. it will be understood that the boundary layer of air on and adjacent to the inside wall ofchamber 12 will be increased in thickness as compared with a nonstreamline profile, Thus the velocity of the air on or adjacent the inside wall is decreased.

Outer Wall Body 16 has an outer wall 16b adjacent to which inner wall [20 of chamber 12 is inclined in an upwardly and outwardly direction in a manner well known by those skilled in the art. As air valve 15 moves upwardly, the clearing for airflow between outer wall 16!) and inner wall 120 increases in area when the lower edge of wall 16!) passes the beginning lZh oi inclined walls 120 Accordingly, with valve seat 17 secured to stem 20 by lock screw 171* in the position illustrated. valve 15 travels a substantial distance in response to a minimum de mand for air by the engine. At idle speed the engine demands a minimum amount ofair and valve 15 is required to travel up wardly until the lower edge of wall [6b passes the beginning 12b of the incline and until the minimum demand for air is satisfied. It will be understood that after the lower edge passes the incline beginning [2b, the air demand is controlled by the slope of the incline. This travel, of substantially a high order of magnitude, is transmitted to pin 34 thereby providing a sub stantially large area clearing at idle. On the other hand, if valve seat 17 is secured to stem 20 at a position above that illustrated. valve 15 is required to travel upwardly a lower order of magnitude to meet the engine minimum demand for air flow at idle. Accordingly, at idle speed the annular clearing between pin 34 and seat 37 is of substantially less area than in the previous position of seat 17. In this manner, by varying the position of seat [7 the travel of valve 15 may be adjusted to control the fuel air ratio at idle.

Travel Control Leaves The travel of air valve [5 may also be controlled by adjusting the position oftravel control plates or leaves 420-d, with each of the leaves defining a segment ofa fiat washer, A slot is formed in each of the leaves 42a-d to receive a screw which is threadedly engaged in an opening formed in the upper surface I61? of body 16. [n this manner leaves 42a-d may be adjusted and then rigidly secured in position to determine the effective inside diameter of the central opening of air valve 15.

('iuides in order to guide the movement of air valve 15 there are provided three downwardly extending projections l8a-c from annular body 16. Projections l8a-c include downwardly extending keyways -4 respectively for receiving respective guide pins 230-0 secured in chamber [2. in addition a longitudinal keyway ]'M is formed in the cylindrical inner wall of seat 17 for receiving a longitudinal key 178 formed on the outer surface ofstem 20v lDLl': ADJUST The fuelair ratio at idle maybe finely adjusted by raising or lowering metering pin 34 while valve 15 is in a static rest posi tion in the following manner. Metering pin 34 is fixedly secured to damper plate 36 which has a notch guide 360. Guide 36a is engaged by a vertical pin 45 secured to the vertically extending cylinder wall of a cylindrical damper housing 46 surrounding plate 36. The lower end ofdamper housing 46 is closed and there extends downwardly from the closed end a screwhead 46a which may be turned from the outside ofcarhuretor 10 by inserting a screwdriver in head 46a. Accordingly, by manually turning screwhead 460, housing 46 is rotated thereby rotating damper plate 36. metering pin 34 and rod 30 Accordingly, as damper plate 36 is rotated the upper end oi rod .30 is screwed into or out of threaded opening 281 of holder 28. in this manner metering pin 34 may be raised or lowered with respect to waive scat 37 while valve 15 is in the same static rest position VARIABLE DAMPING Damping of air valve 15 is provided by fuel acting as a damping medium on damper plate 36. As valve 15 and plate 36 go lower, fuel is forced out of the volume of fuel between plate 36 and the lower closed end of housing 46. This fuel flows out through the relatively small clearing 36a forming a fluid connection between the edge of plate 36 and the inner wall of housing 46 into the remaining fuel in chamber 22. Similarly, as valve 15 and plate 37 are raised, fuel flows from chamber 22 through the fluid connection into the space between plate 36 and the closed end of housing 46. it will be understood that this fluid connection is of constant cross-sec tional area thereby producing a constant damping factor In order to provide a variable damping factor, the fluid connection is eilectively varied in cross-sectional area thereby to vary the Hou ii fuel in the following inanrieiv As best shown in FIGS 4 and 5, a plurality ofequally spaced openings 47 are formed around a circumference of housing 46 ad acent to the lower closed end. A damper control cylinder 50 having a lower closed end 50a receives damper housing 46 with sciewhead 46a extending through a central opening in end 50a An annular shaped shoulder extends horizontally from the lower closed end 500 and has formed therein semicircular slots 50bc. Screws Sla-b extend through respective slots SOb-c and engage threaded openings on the underside of a bottom base 56. Base 56 is fixedly secured to the bottom edge of housing I0 as for example by screws, It will be understood that base 56 may be an integral part of housing 10. Cylinder 50 may be rotated about its axis by first loosening screws Sla-b and then inserting a spanner wrench in the openings provided. Screws 5104: are then tightened.

The vertically extending cylindrical wall of cylinder 50 may be about half the height of the wall of housing 46 with an O- ring seal 52 being disposed in sealing relation between the two walls. Below Oring seal 52 and adjacent openings 57 there are provided in the wall of control cylinder 50 two opposed elongated rectangular openings 54a-b. Base 56 includes a vertically extending cylindrically shaped wall 57 which extends above openings 54a-b. Opposing sections of wall 57 are beveled to form 57a-b. Lines drawn from the ends of sections 57a--b to the centerline of base 56 form angles which may be approximately the same as angles formed by lines drawn from the ends of openings 54a-b to the center of cylinder 50. It will now be understood that an adjustable fluid connection may be ed from the fuel in housing 46 below plate 36 through tings 47 leading to

openings

54a and 54b, through

beveled ions

57a, 57b, to the fuel within chamber 22. The foregoidjustable fluid connections are in parallel with each other with the constant fluid connection through the side of 5 a 36 to provide a resultant adjustable fluid connection.

order to adjust the clamping, cylinder 50 may be rotated it its axis in the manner previously described so that tings 54a-b are substantially in line with sections 57a-b actively. In this way there is provided a resultant fluid conion of maximum crosssectional area thereby to produce mum damping. On the other hand, cylinder 50 may be Led so that openings S4a-b are completely covered by vernonbeveled walls 57 so that the resultant fluid connection minimum cross-sectional area thereby providing maxn damping. It will be understood that damper control der 50 may be turned to positions between the foregoing :me minimum and maximum damping positions to adjust lamping to an optimum level.

FLOAT CHAMBER 62-FUEL CHAMBER 22 .el is supplied to chamber 22 from a float chamber 62 aining a float 65 by way of fluid connection or pipe 60. 60 has an outlet in chamber 22 adjacent the bottom :of and an intake opening 60a in chamber 62 which is .ed in the center of the projected horizontal area of iber 62. At best shown in FIG. 2 the horizontal projected of chamber 62 defines a shaped section having curved s 62a-b and straight edges 62c-d parallel to each other. ;e 60a to be in the center of the projected area is disposed :r to edge 620 than edge 62b and equidistant between llel edges 62c-d.

locating intake 60a in the center of the area, it will be unood that when the automobile carrying carburetor 10 the head of fuel at intake 60a is maintained constant. For lple, the automobile tips to the right thereby lowering the end and raising the left end of housing 10. Thus, in iber 62 the fuel is deeper in the right-hand end than in the land end, but the center of chamber 62 remains constant pth for a constant head This constant head is maintained e automobile tips in any direction. ln this manner there is :ved constant static fluid pressure at intake 600. e fuel in chamber 22 may not change in depth since the e chamber is substantially filled with fuel as a result of the evel in float chamber 62 being maintained above the top amber 22. Accordingly, with a constant static fluid presat intake 60a, the static fluid pressure is maintained conin chamber 22. Accordingly, the fuel feed to metering M is a function only of the suction produced in mixing lbCl 39 and is not dependent on a varying fluid pressure. is manner more accurate control of the air-fuel mixture is ned, and therefore there is no cutoff or surge due to the 1g of the carburetor. With a separate float chamber 62 l fuel chamber 22 containing damper plate 36, there is ald independent movement of float 65 and plate 36 ifically, when damper plate 36 rises, it is because the en requires more fuel from chamber 22 and therefore float ay lower to allow more fuel to flow into chamber 62. If s two actions occur at the same time in the same lber, as in the prior art, the damper plate prevents the from swinging freely to feed in fuel. Therefore, an uny fuel flow results which causes a hesitation of the engine irmance. This hesitation is caused since the flow of fuel the chamber is in a direction opposite that of damper 36 Accordingly, by separating float chamber 62 from lbfil' 22, there is provided flexibility in allowing the float he plate to move without producing interfering actions. lal 65 floats on the surface of the fuel in chamber 62 and ecured thereto the lower end of a float arm 66 which as about a pivot 68 and engages the left-hand end of a needle 70. When float 65 is at a lower position indicating .'"uel is required in chamber 62 the upper end of arm 66 moves to the left. thereby allowing fuel under essure in inlet 73 to push open valve needle 70 from valve seat 72 and to flow into chamber 62. When float 65 reaches its upper limiting level, the upper end of arm 66 pushes needle 70 to the right against valve seat 72 thereby preventing fuel from flowing into chamber 62. The foregoing float and valving arrangement is adjusted so that the lower fuel level is higher than the top of chamber 22 for the reason previously described. In addition inlet 60a is substantially below the lower fuel level in chamber 62 to assure that no foaming fuel passes into chamber 22.

It will be understood by those skilled in the art that suitable O-ring seals may be provided in sealing relation between cover 56 and chamber 22 and between cylinder 50 and cover 56.

Float chamber 62 illustrated in FIGS. 1 and 2 may be replaced by a floatless constant level chamber as shown in FIG. 6. Carburetors without floats are known in the art and have the advantage of avoiding the use of a float. When a float is damaged for example the carburetor floods and fuel may escape from the carburetor onto the hot manifold causing a fire.

However in prior floatless carburetors the overflow outlet has been connected to the side of a single chamber containing the float and the fuel chamber. Such a single chamber had the disadvantages described above. As illustrated in FlG. 6 a separate floatless chamber 80 is provided for supplying fuel to chamber 22. As in the carburetor of FIGS. l5, tube 60 has an outlet in chamber 22 and an intake opening 60a located in the center of the projected horizontal area of chamber 80. A constant flow of fuel enters by way of inlet 82 from a fuel pump (not shown). In this manner fuel fills chamber 80 until it reaches the level of an overflow outlet opening 84 of a tube 85. The overflow fuel flows into opening 84 through overflow tube 85 back to the fuel tank (not shown). Tube 85 extends through a lower opening 88 of chamber 80 and is secured in place by a squeeze fitting 90 threadedly engaged in flange 880. A gasket is disposed in sealing relation between fitting 90 and opening 88. To change the fuel level tube 85 may be moved upwardly or downwardly by loosening fitting 90 and adjusting tube 85. Opening 84 is always maintained above intake opening 60a.

Outlet opening 84 is located in the center of the projected horizontal area of chamber 80. Thus, as the automobile tips the fuel becomes deeper at one end of chamber 80 with respect to the other end but the center of the area is maintained at a constant depth without the use of a float. Accordingly, the amount of fuel in chamber 80 is maintained constant. As previously described with intake 60a in the center of the projected horizontal area, as the automobile tips a constant head is maintained on opening 60a. in this manner the static fluid pressure is maintained constant in chamber 22 and the fuel feed to metering pin 34 is a function only of the suction produced in mixing chamber 39. Now that the principles of the invention have been explained, it will be understood that many more modifications may be made. For exam le, the four straight ribs Isa-d forming a spider as shown in FIGS. l-4 may be twisted at a slight angle from the vertical center line of each rib as illustrated in FlG. 3A. Thus, ribs l5eh form a slight spiral and these ribs guide the airflow through the inner opening of air valve 15 to produce a small swirl action in the fluid motion in chamber 12. This swirling action in conjunction with the thick boundary layer of air adjacent the inner wall causes the heavier fuel particles in chamber 12 to drop downwardly to be broken into small particles when they meet the fresh air entering from intake ll. Thus there is provided an improved screen for fuel particles.

Iclaim:

l. A carburetor for an internal combustion engine comprismg a. a housing having an air intake opening and an output opening,

b. a chamber in said housing for mixing said air with fuel thereby to produce a suspension of fuel particles in air,

c. fuel valve means communicating with fuel in a chamber for controlling the flow of fuel to said mixing chamber,

fill

g ad ustable means for selectively varying the effective area ofsaid inner opening of said air valve means, said adjustable means comprising substantially horizontal travel conllUl plates adjustably secured to said air valve means for movement radially to the axis of said air valve means for selectively varying said effective area of said inner open mg

Claims

1. A carburetor for an internal combustion engine comprising a. a housing having an air intake opening and an output opening, b. a chamber in said housing for mixing said air with fuel thereby to produce a suspension of fuel particles in air, c. fuel valve means communicating with fuel in a chamber for controlling the flow of fuel to said mixing chamber, d. a float chamber for supplying fuel to said fuel chamber, e. a fluid coupling for flow of fuel having an inlet in said float chamber and an outlet in said fuel chamber, said inlet being disposed in said float chamber to provide a constant static fluid pressure in said fuel chamber, f. air valve means moveable in accordance with the airflow from the said intake to said output opening, said air valve means having an inner opening for said air flow, and g. adjustable means for selectively varying the effective area of said inner opening of said air valve means, said adjustable means comprising substantially horizontal travel control plates adjustably secured to said air valve means for movement radially to the axis of said air valve means for selectively varying said effective area of said inner opening.