US 3544290 A
Description (OCR text may contain errors)
ET AL 3,544,290
Dec. 1, 1970 R. c. LARSON. sR..
- FUEL ATOMIZING UNIT Filed Oct. 21. 1965 F l ,NVENTOR RAYMOND c. LARSON Sr. BY CHARLES A. MORRONE PATENT AGENT United States Patent 3,544,290 FUEL ATOMIZING UNIT Raymond C. Larson, Sr., 2944 Rustic Drive, San Jose, Calif. 95124, and Charles A. Morrone, 1180 Alice Drive, Santa Clara, Calif. 95050 Filed Oct. 21, 1965, Ser. No. 499,641 Int. Cl. B01f 3/ 22; F02m 29/02, 29/04 US. Cl. 48-180 3 Claims ABSTRACT OF THE DISCLOSURE A fuel atomizing unit arranged for insertion in the duct connecting a carburetor to the intake manifold of an internal combustion engine including a strainer for the fuel air mixture and a vibratory structure in the form of a vane resonator or propellor resonator located in the path of the fuel-air mixture so as to automatically vibrate and generate sonic vibrations in response to the flow of the fuel-air mixture through the duct.
The present invention pertains to an improved carburetion system and more particularly to an improvement in a fuel atomizing unit capable of being installed in a conventional carburetor.
The basic function of a carburetor is to provide an intimate mixture of fuel and air for consumption by an internal combustion engine. Efliciency of mixing depends upon atomizing the fuel into minute particles. Large particles, or droplets, allow some of the fuel to avoid contact with air and thus to go through the engine unburned. The typical modern carburetor provides a duct through which air is drawn by the pumping action of the engine and atomizing is accomplished by delivering fuel in liquid form through a small nozzle to the center of the air stream. Owing to a vacuum which is created in the vicinity of the nozzle by the movement of the air, the fuel is drawn out of the nozzle, separated into droplets and carried into the engine.
It is found, however, that this method of mixing is not perfect. Even with carburetors that are in proper operating condition, exhaust analyses show that a significant portion of the fuel is never completely burned.
Therefore, the general object of the present invention is to provide an improved carburetion system that will substantially increase the efiiciency of combustion.
An important feature of the present invention is to provide a fuel atomizing unit that may be installed in conjunction with each duct of a conventional single or multiple barrel carburetor.
Another feature of the present invention is to provide a fuel atomizer or diffuser that will atomize the fuel in several stages which coactively produce an optimum combustible mixture.
A further feature of the present invention is to provide a fuel diffuser that atomizes the fuel by sonic pressure.
An added feature of the present invention is to provide a fuel diffuser that atomizes the fuel by impact.
The means by which the object of the invention is accomplished and by which the features are provided will be evident from the following description and the accompanying drawings in which:
FIG. 1 is an elevational view partly in section of a portion of a carburetor attached to an engine fuel manifold r 3,544,290 Patented Dec. 1, 1970 in conjunction with which one embodiment of the present invention is installed,
FIG. 2 is a transverse sectional view taken in the direction of the arrows 22 in FIG. 1,
FIG. 3 is a transverse sectional view taken in the direction of the arrows 3-3 in FIG. 1,
FIG. 4 is a fragmentary sectional view of a portion of a carburetor and fuel manifold showing a propellor-type resonator installed as a modified embodiment of the in vention, and
FIG. 5 is an enlarged plan view of the propellor resonator as seen in the direction of the arrows 5-S in FIG. 4.
The fuel diffuser or atomizer may be installed with a conventional carburetor 11 without any change in the basic design of the carburetor. FIG. 1 shows a portion of a typical installation in which the fuel diffuser 12 is inserted in an engine intake manifold 13 in line with a duct 14 provided by the carburetor 11 and secured by the bolting of the carburetor 11 to the manifold 13. As the drawing shows, the conventional arrangement of the carburetors internal parts is undisturbed. Up near the air inlet end of the duct 14 is a horn-shaped orifice known as a venturi 15, and within the venturi 15 is a nozzle, or jet 16, for introducing fuel to the space within the venturi 15. A passageway 17 drilled in the body 18 of the carburetor housing communicates with a fuel reservoir '19 from which the fuel is drawn. Below the jet 16 is a throttle valve 20 comprising a circular disk pivotally mounted on a pivot pin. The structural mounting for the jet 16 and the operating linkage for the throttle valve 20 form no part of the present invention and therefore are not shown.
Means for subjecting the fuel to a sonic pressure, means for subjecting the fuel to an impact and means for straining the fuel are all contained in a basket-like structure under the throttle valve 20. Such structure includes a cylindrical side wall 21 which is encompassed Within the duct 14, and is terminated at the top by a radial mounting flange 22. A vane resonator 23 is carried at the bottom of the side wall 21 and an upwardly concave screen or other foraminous member 24 is supported by the side wall 21 directly above the resonator 23. The radial flange 22 is placed between the carburetor flange 25 and the manifold flange 26, wherefore tightening of fastening nuts 27 on mounting bolts 28 not only holds the carburetor 11 in place but secures the fuel diffuser 12 also.
FIG. 2 shows another view of the vane-resonator 23 which is the means of producing the sonic pressure within the carburetor duct 14. Supported by the side wall 21 is a first cross bar 30 and perpendicular thereto is a second cross bar 31 also supported by the side wall 21. The first cross bar 30 serves as a mounting bracket to which two vibratory vanes 23a, 23b are attached. Two other vanes 23c, 23d utilize the second cross bar 31 as a bracket. As may be seen in FIG. 2, the total upper surface area of the vanes 23 is almost as great as the transverse cross sectional area of the cylindrical side Wall 21. However, the vanes project downwardly (FIG. 1) and thus provide sufficient space between them for the passage of the fuelair mixture.
The material from which the vanes 23a, 23b, 23c, 23d are made is of a resilient type commonly used in tuning forks and not more than approximately .025 inch thick. Impact of particles against the vanes establishes a sonic (or ultrasonic) vibration or resonance.
The foraminous member 24, shown in FIG. 3, is fully described in the prior co-pending application for Fuel Atomizing Unit, Ser, No. 375,846, filed June 17, 1964 now US. Pat. No. 3,449,098 issued to R. C. Larson, Sr. on June 10, 1969. As a means for providing input and for straining the fuel droplets, the foraminous member 24 preferably should have twenty apertures per linear inch in each direction. In order to increase the number of openings through which the fuel may pass, the member 24 is constructed in a hemispherical or other concave shape (as shown in FIG. 1). However, a flat member also will give good results.
The operation of the vane-type sonic difluser 12 dependsfor its effectiveness upon the velocity of the mixture drawn by the engine through the carburetor 11. When the throttle valve is opened, difference in pressure between the atmosphere and the interior of the intake manifold 13 causes air to rush through the carburetor duct 14. The manner in which the venturi accelerates this air flow past the fuel jet 16 is well known in the automotive industry and may be learned from any standard textbook on carburetors. Liquid fuel is drawn out of the jet 16 into the air stream in the form of droplets and then passes through the foraminous member 24. The vanes 23 lying below obstruct straight line motion of the mixture and consequently are struck by most of the fuel droplets. Since the vanes 23 all spiral in the same circular direction, the entire fuel-air mixture is deflected into a swirling path. In this state of turbulence the mixture then enters the cylinders of the engine.
The several elements of the described combination coact to complete the atomizing of the fuel begun by the venturi and the fuel jet. The partial breakup of the droplets caused by their striking the foraminous member 24 and then being forced through the apertures therein is continued as they travel through a region of sonic pressure waves existing between the member 24 and the vanes 23a, 23b, 23c, 23d lying below. It is to be understood that the pressure waves referred to herein as sonic are not limited to the range of sound frequencies audible to the human ear. The term sonic is used herein to include all pressure variations whether audible or not. Each vane, being resilient and mounted on a cross bar 30, 31, vibrates when it is agitated by the passing fuelair mixture. This vibration results in the propagation of sound waves in the fuel-air duct and the mixture is thus effectively exposed to pulsations in ambient pressure. Theoretically speaking, the coacting elements or members mentioned above resonate like an open or closed, or more accurately, a partially closed pipe. Partial closure of the duct is affected by a first member, the vaned structure 23a, 23b, 23c, 23d in FIG. 1 or alternatively, by a propeller 33 in FIG. 5 and by the foraminous member 24. The resulting partially closed duct, like any partially closed pipe, has an inherent natural vibrational frequency for a column of air-fuel. therein which forces the vanes or propeller mentioned above to vibrate sympathetically. Accordingly, the vanes are made of vibratory material selected to resonate with the air column. The forced vibrations of the vanes or propeller reinforces the vibrations of the air-fuel column in the duct so that oscillatory pressure waves are created. The alternate compression and rarefaction of the air in the duct 14 induces cavitation in each droplet of fuel. Although liquid is generally considered to be incompressible, usually it contains gas bubbles which do respond to changes of ambient pressure. Internal shock waves, produced by the rapid expansion and contraction of trapped gas bubbles, disrupt each droplet. The final breakup of the droplets is accomplished by a second impact of the droplets which occurs on the resonating vanes.
Another embodiment of the invention, shown in FIG. 4, utilizes a propellor-type resonator. The side wall 21 supports a perforated platform 32 (FIG. 5) on which a propellor 33 is rotatably mounted. Any suitable supporting structure may be used in place of the platform 32, provided that the fuel-air stream is not unduly restricted. To assure resonance under the impact of the mixture, the propellor 33, similar to the vanes 23a, 23b, 23c, 23d, preferably is not more than .025 inch thick and also is of the same material as that of which tuning forks commonly are made. The theory of sound generation is the same as it is for the vane-resonator 23 (FIG. 2). The fuel particles are discrete and the series of successive impacts on the propellor blades causes them to vibrate. Rotation of the propellor assures that the blades will beyibrated by the mixture throughout the cross sectional area of the duct. It has been found that when installed in a conventional American automobile engine, a propellor having a 1.125 inch diameter and a blade angle of thirty degrees rotates at approximately 23,800 r.p.m. when the engine is turning at 3000 r.p.m.
It is obvious that whichever of the foregoing embodiments of the present invention is used, the improved efficiency of combustion is a great benefit not only to the individual motorist but to the public as well. Unburncd particles of fuel sent out through the exhaust pipe of an automobile represent money wasted in buying gasoline that is never used. Therefore, higher efficiency means money saved. Furthermore, every bit of half-burned or unburned gasoline vapor that escapes into the atmosphere further pollutes the air. The greater efliciency of combustion resulting from the practice of the present invention means less air-polluting smog and consequently more comfort for the public.
While a single barrel carburetor is shown, it is understood that the pr'esent invention and all its embodiments may be applied to multiple duct carburetors, Furthermore, it is understood that modifications and variations of the sonic fuel diffuser disclosed herein may be made without departing from the spirit of the invention and from the scope of the appended claims.
What is claimed is:
1. In an engine having an intake manifold and a carburetor for supplying atomized fuel to the manifold, the improvement comprising,
a fuel duct disposed between said intake manifold and said carburetor for transporting atomized fuel therebetween, said fuel duct having opposing end elements partially open to the passage of fuel, wherein the first of said elements comprises means located in the upstream portion of said fuel duct for straining the atomized fuel and wherein the second element comprises a vibratory member in the form of a propellor-resonator located in the downstream portion of said fuel duct, said propellor resonator being formed of a material which resonantly vibrates in automatic operative response to the flow of atomized fuel to the manifold for creating and subjecting said atomized fuel to a sonic pressure.
2. The improvement of claim 1 wherein the means for straining is a foraminous member disposed substantially transverse to the duct,
3. In an engine having an intake manifold and a carburetor for supplying atomized fuel to the manifold, the improvement comprising, v,
a fuel duct including a cylindrical side wall disposed between said intake manifold and said carburetor for transporting atomized fuel therebetween, said fuel duct having opposing end elements partially open to the passage of the fuel, wherein the first of the said elements comprises means in the form of a hemispherical foraminous member located in the upstream portion of said fuel duct for straining the atomized fuel and wherein the second element is located in the downstream portion of said fuel duct and comprises a first cross-bar spanning the side wall diametrically, a second cross-bar diametrically spanning the side wall perpendicular to the first cross-bar, a plurality of vibrator vanes on the first 5 6 and second cross-bars, each of said vanes providing 1,689,446 10/1928 Miller et al 48-180 an extended obstructing surface disposed at an 1,446,086 2/1923 Green 48180 oblique angle with the longitudinal axis of said duct, 2,745,372 5/ 1956 Chertoff. said vanes being formed of a material which resonant- 2,078,558 4/ 1937 Borell 48-180 ly vibrates in automatic operative response to the 5 3,437,467 4/ 1969 Jacobus 48-180 flow of atomized fuel to the manifold for creating 3,449,098 6/1969 Larson 48-180 and subjecting said atomized fuel to a sonic pressure.
MORRIS O. WOLK, Primary Examiner References cted B. s. RICHMAN, Assistant Examiner UNITED STATES PATENTS 10 1,040,853 10/1912 Bergold 4s -1s0 1,298,315 3/1919 Evans 48-180 123-141; 261-78, 84
1,305,064 5/1919 Cochran 48-180