US3719352A

US3719352A - Inertia responsive carburetor fuel flow control means

Info

Publication number: US3719352A
Application number: US00197901A
Authority: US
Inventors: R Harrison; T Johnson
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1971-11-11
Filing date: 1971-11-11
Publication date: 1973-03-06
Anticipated expiration: 1990-03-06
Also published as: AU459564B2; DE2254464A1; GB1364580A; JPS5517223B2; CA964143A; JPS4854318A; AU4742772A

Abstract

AN INERTIA RESPONSIVE CARBURETOR FUEL FLOW CONTROL MEANS WHICH ACCOMMODATES FOR VARIATIONS IN FUEL LEVELS IN THE FUEL BOWL CAUSED PRIMARILY BY CENTRIFUGAL FORCES SET UP BY VEHICLE CORNERING. THE INVENTION IS USED WITH MULTI-BARREL CARBURETORS HAVING SEPARATE PASSAGES TO EACH BARREL FROM THE FUEL BOWL. AN INERTIA SENSING MEANS, EITHER IN THE FORM OF A SPRING BIASED WEIGHTED ARM OR A FUEL SURFACE ANGLE SENSOR, CONTROLS THE POSITIONS OF METERING RODS THAT COOPERATE WITH ORIFICES IN EACH PASSAGE TO MAINTAIN ESSENTIALLY IDENTICAL RATES OF FLOW THROUGH EACH PASSAGE WHEN THE PASSAGES EXPERIENCE DIFFERENT FUEL HEADS.

Description

Mal'Ch 6, 1973 R. s. HARRISON ET AL INERTIA RESPONSLVE CARBURETOR FAUEL FLOW CONTROL MEANS Filed Nov. 1l, 1971 United States Patent O 3,719,352 INERTIA RESPONSIVE CARBURETOR FUEL FLOW CONTROL MEANS Robert S. Harrison, Detroit, and Thomas R. Johnson, Ann Arbor, Mich., assignors to Ford Motor Company, Dearborn, Mich.

Filed Nov. 11, 1971, Ser. No. 197,901 Int. Cl. F02m 5/02 U.S. Cl. 261-23 A 11 Claims ABSTRACT F THE DISCLOSURE An inertia responsive carburetor fuel flow control means which accommodates for variations in fuel levels in the fuel bowl caused primarily by centrifugal forces set up by vehicle cornering. The invention is used with multi-barrel carburetors having separate passages to each barrel from the fuel bowl. An inertia sensing means, either in the form of a spring biased weighted arm or a fuel surface angle sensor, controls the positions of metering rods that cooperate with orices in each passage to maintain essentially identical rates of flow through each passage when the passages experience different fuel heads.

BACKGROUND AND SUMMARY OF THE INVENTION Most multi-barrel carburetors in use today have laterally spaced main jets and main fuel wells which interconnect the fuel bowl and the several venturis. The result is that when the vehicle corners the centrifugal forces acting on the fuel in the carburetor fuel bowl cause the fuel surface to assume an angle relative to the normal horizontal fuel level. If the jets and the main wells are located symmetrically on either side of the fuel bowl center line, one of the jets and main wells experiences an incerased fuel head while the other of the jets experiences a decreased head. Thus, the mixture delivered by one of the venturi barrels is overly rich while the mixture delivered by the other barrel is overly lean. In a typical V8 engine, one of the barrels of a two-barrel carburetor feeds the right bank of cylinders, while the second barrel feeds the left bank. If the cornering forces are exceptionally large, the engine may experience stumble because of improper fuel mixtures.

This invention provides a fuel flow control means that eliminates stumble during severe cornering maneuvers. The invention also provides means that control fuel ows to each barrel to accommodate for the different fuel heads acting on the individual main jets and main fuel wells. The invention further provides means that deliver essentially identical fuel ows through each of the main jets regardless of whether the vehicle is proceeding in a straight direction or it is cornering. Finally, the invention provides fuel flow control means that is adaptable for use with conventional carburetors, that may be economically produced and that is reliable in operation.

A fuel flow control means for a carburetor having at least two barrels constructed in accordance with this invention includes first and second passage means leading from the fuel bowl to first and second barrels, respectively. First and second metering means are constructed to regulate the ows through the first and second passages, respectively. An inertia sensor, movable in response to inertia forces acting on the carburetor and to maintain essentially identical fuel ow rates through the passages irrespective of inertia forces acting on the carburetor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a cross sectional view of a carburetor taken through its fuel bowl in the longitudinal direction of the vehicle.

FIG. 2 is a cross sectional view taken along the line 2 2 of FIG. l.

FIG. 3 is a cross sectional view similar to FIG. 1 but showing an alternate embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. l and 2 of the drawings illustrate the invention embodied in a typical two-barrel carburetor which is generally used as a part of a V-S engine. The carburetor includes a housing 12 having two

barrels

14 and 16 and a fuel bowl 18 formed therein. Each of the barrels includes a substantially identical main venturi 20` and booster venturi 22.

The normal operation of the carburetor is typical to that of conventional two-barrel carburetor. Air passing through the

venturis

20 and 22 cause reduced air pressures at nozzles 24 relative to the atmospheric air pressure within the fuel bowl 18. The air pressure differential forces fuel fromy the fuel bowl through

main metering jets

26 and 28 into passages 30l and 32 which discharge into the respective main fuel wells 34. FIG. 2 is a cross sectional view through barrel 16 and main jet 28y of PIG. l. A cross sectional view through venturi 14 and main jets 26 would be essentially identical and would show the second of main wells 34 and its connecting passages. A small quantity of air is introduced into the main wells through passages 42 -which open to the atmosphere. The mixtures then proceed from the main wells 34 to the nozzles 24 of the booster venturis 22 through passages 38. There the mixtures are introduced into the air streams passing through each barrel and are discharged past the respective throttle plates 40.

The fuel bowl 18 includes a oat 42 which operates an inlet valve (not shown) to maintain a constant fuel level within the bowl. The surface of the fuel is designated by reference numeral 44. An inertia sensor assembly 46 is positioned on a pin 48 protruding from a wall of the fuel bowl 18 at a location between and above the

main jets

26 and 28. The pin pivotally supports arm member 50 which, in turn, supports a pair of

tapered metering rods

52 and 54 within each of the main jets. The metering rods are calibrated so that when the arm member is horizontal and the fuel surface is level, the tapered portions of the rods are partially received within the orifices of the

metering jets

26 and 28. The arm member is generally U-shaped and has a pair of floats 56 and 58' positioned at each end. The vertical location of the oats is determined in accordance with the normal fuel level 44 within the bowl 18.

When the automobile is traveling in the direction of arrow 60 along a straight path, there are no inertia forces acting upon the fuel Within the bowl 18. When the vehicle corners even though the speed is kept constant, the centrifugal forces set up by the cornering cause the fuel surface to assume an angle similar to that shown by the dotted line 62 in 'FIG. 1. The magnitude of the fuel surface angle is proportional to the centrifugal force which, in turn, is a function of the velocity of the vehicle and its turning radius. The

floats

56 and 58 follow the surface of the fuel and cause arm 50 to pivot about pin 48. Metering rod 54 is drawn upwardly from its position in FIG. l and increases the restrictions of main jet 2-8. Metering rod 52 is lowered and decreases the restrictions of main jet 26. It may be seen from FIG. 1 that under cornering conditions, the fuel head acting on main jet 28 is less than the fuel head acting on main jet 26. Similarly, the fuel heads acting on each of the main wells 34 are unlike. If the main jet orifices were to have identical effective openings during cornering the fuel flow through the jet 28 would exceed the fuel fiow through the jet 26 because of the fuel head differential. At extreme conditions, engine stumble would result either from one of the bank of cylinders having too lean a mixture or the other bank of cylinders having a too rich a mixture.

It thus may be seen that the invention provides for the increased restriction of the effective orice of the main jet that experiences the greater fuel head and the corresponding decreased restriction of the effective orifice of the main jet having the lesser fuel head. The

main jets

26 and 28 and the portions of the

metering rods

52 and 54 interacting with the main jets are so contoured and calibrated that the fuel air ratio is kept constant for each of the barrels of the carburetor and, consequently, for each of the banks of the V-8 engine. It has also been shown that the fuel and the pivotable float assembly 46 operates as an inertia sensor to position the metering rods within their corresponding orifices.

DESCRIPTION OF AN ALTERNATE EMBODIMENT OF THE INVENTION FIG. 3 of the drawing illustrates an alternate embodiment of the invention. With the exception of the appara tus to be discussed below, the carburetor structure of the second embodiment is identical to that of the preferred embodiment and the same reference numerals are used to identify identical parts.

The inertia sensor assembly 64 includes an inverted cross-shaped arm member 66 pivotally attached Within the fuel bowl 18 to pin 48. The arm member is normally biased into a vertically aligned position, as shown in FIG. 3 by a spring 68 which is secured to the base of the fuel bowl between the

main jets

26 and 28. A pair of tapered metering rods 70 and 72 pivotally depend from the horizontal arm 74 of the cross member 66 and have tapered ends which are received within the orifices of the

metering jets

26 and 28. A vertical leg 76 extends upwardly past the normal fuel level 44 and has mounted at its end a weight 78. When the vehicle is traveling in a straightforward direction there are no forces tending to move the sensor assembly 64 out of its normal vertically biased position. When the vehicle corners, the weight 78 is drawn by centrifugal force to the side corresponding to the increased fuel head. As the arm pivots about the axis of pin 48 it increases the restriction of the main jet having the greater fuel head and decreases the restriction of the main jet having the lower fuel head. The weight 78 and the metering rods 70 and 72 are calibrated as a function of the fuel head differential to maintain essentially identical flows through the main jets during vehicle cornering.

lModifications and alterations may occur to those skilled in the art which are included Within the scope of the following claims.

We claim: 1. A fuel flow control means for a carburetor having at least two barrels and a fuel bowl comprising:

first and second passages leading respectively from said fuel bowl to said first and second barrels, first and second metering means constructed to regulate and vary the iiows through said first and second passages, respectively, inertia sensor means responsive to inertia forces experienced by the carburetor,

said inertia sensor means being coupled with said first and second metering means to simultaneously increase the restriction of one of said passages and decrease the restriction of the other of said passages in response to inertia forces acting on said carburetor and to maintain essentially identical fuel iiow rates through said passages irrespective of inertia forces acting on said carburetor.

2. A fuel flow control means according to claim 1, said first and second metering means comprising:

a pair of metering rods,

a pair of metering orifices with said first and second passages receiving said metering rods.

3. A fuel tiow control means according to claim 2, said metering rods having tapered ends cooperating with said metering orifices.

4. A fuel flow control means according to claim 1, said inertia sensor comprising float means pivotally mounted relative to said fuel bowl movable in response to changes in the surface angle of the fuel within said fuel bowl.

5. A fuel flow control means according to claim 1,

said inertia sensor comprising an arm pivotally mounted relative to said fuel bowl,

an inertia weight mounted on an end of said arm,

said arm movable in response to inertia forces acting on said carburetor.

6. A fuel flow control means for a motor vehicle engine carburetor having at least two barrels and a fuel bowl comprising:

first and second passage means leading from said fuel bowl to said first and second barrels, respectively, first and second metering orifices positioned within said first and second passages, respectively,

said orifices being laterally spaced one on each side of a line parallel to the straightforward direction of travel of the vehicle,

first and second metering rods received within said first and second metering orifices, respectively, and movable relative thereto to regulate flow through said orifices,

inertia sensor means responsive to centrifugal forces experienced by the carburetor,

said sensor including an arm member pivotable about a fixed axis parallel to the straightforward direction of travel of the vehicle, said metering rods being carried by said arm member, said sensor means and said metering rods being movable in response to inertia forces acting on the carburetor to simultaneously increase the effective restriction of one of said passages and decrease the effective restriction of the other of said passages and to maintain substantially identical fuel flow rates through said pasages irrespective of inertia forces acting on said carburetor. 7. A fuel tiow control means according to claim 6, said metering rods having tapered ends cooperating with said metering orifices.

8. A fuel iiow control means according to claim 6, said inertia sensor means comprising oat means secured to said arm member at a position corresponding to normal height of the fuel with said fuel bowl,

said arm member being pivotally movable in response to changes in the surface angle of the fuel within the fuel bowl.

9. A fuel flow control means according to claim 8,

said arm member having one portion extending laterally and upwardly from its xed pivot axis and a second portion extending laterally to the other side and upwardly from said fixed pivot axis,

said float means comprising individual dioats secured to ends of said first and second portions of said arm member.

10. A fuel flow control means according to claim 6, said inertia sensor means comprising a weight secured to said arm member at a position above the normal fuel level within the fuel bowl.

11. A fuel ow control means according to claim 10, spring means biasing said arm member toward a normal vertical position.

References Cited UNITED STATES PATENTS '2,718,387 '9/1955 'Carlson et al. 261-DIG. 50 3,633,610 1/1972 Hellqvist 137-398 6 FOREIGN PATENTS 466,335 5/1937 Great Britain ..-137-38 ROBERT G. NILSON, Primary Examiner 5 E. K. LOOK, Assistant Examiner U.S. Cl. X.R.

261-67, 70, DIG. 50; 137-44, 45