Mixing Chamber for an Intake Manifold

Technical Field

This invention pertains to a mixing chamber positioned in a normal aspiration engine between the carburetor and the intake manifold. The primary object of the invention is to increase the degree of vaporization of gasoline introduced _^ into the fuel-air mixture as it proceeds from the carbure¬ tor to the intake manifold. The device employs a splatter plate and a diffusion screen heating and agitating the fuel- air mixture as it proceeds through the device. The vacuum in the intake manifold draws hot air through the system from the exhaust manifold heating the interior of the mixing chamber, and the splatter plate, and the diffusion screen. This enhances the vaporization of the fuel in the fuel-air mixture. To further improve the vaporization in the device as a adjunct there may be employed a fuel tank vapor circuit which injects air into the fuel tank and withdraws vapor from fuel tank injecting the vapor into the chamber case between the carburetor and the intake manifold.

Background Art

Numerous approaches have been utilized in efforts to obtain a homogenous fuel-air mixture entering the internal combustion engine. Various designs of intake manifolds partially accomplish this purpose. Super-chargers between the carburetors and intake manifolds are devices which have been utilized. High riser intake manifolds creating a plenum chamber between the carburetors and the intake ports of the engine operate in a similar fashion to the device of this invention. To the best of the knowledge of your applicant, -one of the nearest U. S. patents similar to the device of this invention is the patent to Butler, 4,068,638, which is also a device mounted between the carburetor and the intake manifold and utilizes heated coils in the fuel-air flow

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to enhance the vaporization. Layers of metal balls are employed in Butler to agitate the fuelair mixture.

Disclosure of the Invention

The device of this invention consists principally of a chamber case 10 which is positioned between carburetor 12 and the intake manifold 14. The device is constructed having a chamber case upper half 24 and a chamber case lowe half 26 which have the general configuration of inverted dishes cupped together forming an enclosed chamber. At the juncture of the two halves is secured a diffusion screen 30 projecting the maximum diameter of the chamber case and encases a splatter plate 28 positioned in the center of the diffusion screen 30. A hot air conduit 32 including a looped central heating coil 34 is in contact with the splatter plate and/or diffusion screen. The vacuum of the intake manifold draws warm air from the exhaust manifold through the hot air conduit and tend to heat the interior o the mixing chamber and particularly the splatter plate 28 and diffusion screen 30. The hot air induced from the vicinity of the exhaust manifold is exhausted into the chamber case directly above splatter plate 28 and diffusion screen 30.

An adjunct to the invention includes a fuel tank vapor circuit 50 which proceeds from the fuel tank drawing the vaporized gasoline from the fuel tank through the tank vapo pipe around a baffle plate 60 mounted in the upper extremit of the fuel tank 52 with the vapor proceeding through a check valve 62 into a vapor reservoir 64 through a vapor regulator 66 discharging through a vapor jet 68 into the interior of the mixing chamber case 10. These vapors are induced into the intake system between the carburetor and the intake manifold.

Brief Description of Drawings

For an illustration of the device of this invention attention is invited to the attached several drawings

wherein identical reference characters will be employed to refer to identical or equivalent components throughout the various views and the following detailed descriptions.

FIG. 1 is a sectional view, partially fragmented, with the section being cut vertically through the device il¬ lustrating in a fragmented manner the carburetor and the intake manifold. The FIG. illustrates the mixing chamber case and the hot air conduit, the heating coil, and the splatter plate and diffusion screen. Conduit regulator valve and gasoline vapor jet is illustrated.

FIG. 2 is a top view of the mixing chamber illustrating the components as viewed from above. FIG. 2 is a view of the interior of the device as viewed from position of the carburetor.

FIG. 3 is an exploded view of the device of this invention illustrating the various components of the mixing chamber which are positioned between the carburetor and the intake manifold.

FIG. 4 is a schematic illustration of the fuel tank vapor circuit which may be utilized in conjunction with the device to extract gasoline vapors from the fuel tank of the vehicle and induce the gasoline vapors into the mixing chamber between the carburetor and the intake manifold.

Best Mode for Carrying Out the Invention

For an illustration of the construction of the pre¬ ferred embodiment, attention is particularly invited to FIGS. 1, 2, and 3. The mixing chamber for the intake mani¬ fold comprises a chamber case 10 which is mounted between the carburetor 12 and intake manifold 14. The device of this invention may be constructed as an add-on item and mounted on the intake manifold utilizing existing mountings w-ith carburetor 12 being secured to the upper extremity of a chamber case 10 utilizing the stud bolts as suggested in FIG. 1. Carburetor bolt 16 attaches the carburetor to the chamber case 10. The carburetor gasket 18 is

identical to that presently commercially available and may be utilized. Existing manifold bolts 20 can be utilized, o shorter bolts as suggested in FIG. 1 employed and the long stud bolts utilized as carburetor bolts 16. Manifold gasket 22 may be the present gasket utilized for the carburetor being adapted to the chamber case 10 which results in vir¬ tually identical connection of the carburetor being raised slightly above the intake manifold 14. The initial, pro¬ totype model of the preferred embodiment was produced and utilized on a Chevrolet 1/2 ton pick-up truck adapting the standard factory components to the device of this invention It is pertinent to note that the device resulted in improve mileage performance is believed by the inventor that the device resulted in improved combustion and emission control

The chamber case 10 of this invention has a configu¬ ration similar to a dish sitting on the intake manifold 14 with an inverted dish covering the lower dish. This upper section comprises the chamber case upper half 24, with the lower section of the housing comprising chamber case lower half 26. As previously stated, this structure might be incorporated in the design of the intake manifold or might be an add-on item as illustrated in FIGS. 1, 2, and 3. Projecting substantially horizontal through the center of the chamber case 10 at the juncture of chamber case upper half 24 and chamber case lower half 26 is a splatter plate 28 and a diffusion screen 30. The diffusion screen 30 is a wire-like structure which may be soldered or welded into position as substantially as illustrated in sectional view of FIG. 1- Adjacent to or slightly above the diffusion screen 30 is splatter plate 28 which was in the preferred embodiment a perforated metal sheet to which was welded the hot air conduit 32. It would be an acceptable structure fo splatter plate 28, diffusion screen 30, and the hot air conduit 32 to be connected together in an integral struc¬ ture. Constructed in the center of splatter plate 28 or diffusion screen 30 is a looped coil in hot air conduit 32,

with this coil comprising a heating coil. The purpose of this loop is to expose more the hot air conduit 32 to the diffusion screen 30 and splatter plate 28 to provide maximum heat to the fuel-air mixture at its point of entry into the center of the chamber case 10. Proceeding from the heating coil 34 through the chamber case 10 is the hot air conduit extension 36. This conduit 36 projects through the chamber case 10 and is connected to a conduit regulator valve 38 which is connected to conduit return 40 ^~ which projects back into the center of the chamber case 10 and terminates in a hot air outlet 42 which is elbowed down through the center of heating coil 32 onto splatter plate.28. The foregoing structure generally comprises the components of the central structure in the mixing chamber for intake manifold.

As an adjunct to this invention or as an integral component, attention is invited to FIG. 4. Schematic of FIG. 4 illustrates a fuel vapor circuit 50 which leads from the fuel tank 52 of the vehicle and interconnects to the chamber case 10 of this invention. Fuel tank vapor circuit 50 utilizes an external source of air pressure 54. This source might be an air pump of the type presently utilized or previously utilized in air injection emission control systems. Any source of air pressure supplied through an air filter 53 would be satisfactory even utilizing the forward motion of the vehicle or the current generated by the vehicle's cooling fan. An air inlet pipe 56 is connected to the external source of air pressure 54 and projects into the vehicle's fuel tank 52. Leading from the f el tank 52 to the chamber case 20 is a tank vapor pipe 58. Constructed in the fuel pipe 52 immediately below the entry into tank vapor pipe 58 should be a baffle plate 60 to avoid liquid fuel from the fuel tank 52 entering the vapor system. Mounted in the- vapor tank pipe 58 should be a check valve 62 to per¬ mit flow only in the direction from the fuel tank to the chamber case 10. In addition to the operational function of this check valve, it serves a safety factor in the

event of misfire or backfire of the engine through the car¬ buretor. This would prevent any backfire pressure from entering the fuel tank 52. Between the check valve 62 and chamber case 10 is a vapor reservoir 64. To regulate the flow from the vapor reservoir 64 to chamber case 10 is provided a vapor regulator 66. The exhaust from the fuel tank vapor circuit is vapor jet 68 which projects into the interior of chamber case 10 at an angle as suggested in ^" the drawings illustrating this invention. Several factors in the structure and operation of this invention enhance the turbulence of the vapor fuel mixture internal of chamber case 10. One of the factors is the turbulence created by the positioning of splatter plate 28 and diffusion screen 30. Another factor is, in addition to the positioning of the foregoing structure in the flow of the fuel-air mixture the existence of the vacuum in the intake manifold drawing the hot air through the hot air conduit 32 and the position¬ ing of the hot air outlet 42 projecting downward onto the splatter plate .28. This not only assists in elevating the temperature of splatter plate 28 and diffusion screen 30, but collectively tend to elevate the temperature of the fuel-air mixture prior to its entry into the intake manifold 14. Some turbulence will be added by the positive pressure induced into the system by fuel vapor conduit exhausting through vapor jet 68. The overall combination of the foregoing components results in improved vapor fuel mixture being admitted into the intake manifold 14.

Industrial Applicability

The operation of the device of this invention is rather self-evident from the description of the" structure and arrangement of the components. The device is, in essence, a static device which when placed in its operational en¬ vironment produces the desired results. The only components which may be considered as moveable or adjustable perhaps would be the circuit regulator valve 38 placed in the hot

air conduit 32. This valve would preferably be regulated to determine the optimum point of adjustment. It would appear that an increased flow of hot air though the hot air conduit 32 would be desirable in cold weather. Accordingly, conduit regulator valve 38 would be anticipated to operate better in an open condition during winter months. Vapor regulator 66 would be selected or adjusted varying with the degree of pressure provided by the exterior source of air pressure 54. A smooth, gentle flow of air through the fuel tank would appear desirable, and a violent agitation of the fuel in fuel tank would appear undesirable. Accordingly, vapor regulator 66 should be selected or adjusted to provide a smooth, uniform flow under normal operating conditions.