Fuel metering apparatus for a carburetor

Abstract

An improved fuel metering apparatus for a carburetor which provides an optimum air/fuel ratio at all engine speeds and loads. The air/fuel ratio is adjusted by means of a valve sensitive to intake manifold pressure which modulates the amount of bleed air mixed with the fuel prior to the aerated fuel being introduced into the venturi throat of the carburetor.

I claim: 
     
       1. In combination: an internal combustion engine having an intake manifold, an air induction pipe, a venturi throat disposed within said air induction pipe, a fuel reservoir, a fuel nozzle means connecting said fuel reservoir and said fuel nozzle means including an emulsifying well disposed intermediate said fuel reservoir and said fuel nozzle means, said fuel nozzle means disposed in said venturi throat for introducing fuel into a stream of air flowing through said air induction pipe, said emulsifying well including a passage means for directing air into the fuel whereby the fuel delivered to said venturi throat is mixed with air.   means in communication with the interior of said intake manifold for sensing the pressure therein; and   valve means connected intermediate said air induction pipe, upstream of said fuel nozzle means, and said emulsifying well, said valve means being connected to and responsive to said manifold pressure sensing means to regulate air flow through an outlet to said emulsifying well to decrease the amount of air introduced into said fuel upon a predetermined increase in the pressure in said intake manifold and to increase the amount of air introduced into said fuel upon a predetermined decrease in the pressure in said intake manifold whereby a predetermined optimum air/fuel mixture is provided for said internal combustion engine over a wide range of engine speeds and loads said valve means comprising a tubular member having apertures therein connecting the interior thereof in the area adjacent said manifold pressure sensing means to said outlet.   
     
     
       2. The improved fuel metering apparatus described in claim 1 wherein said manifold pressure sensing means is a vacuum diaphragm unit. 
     
     
       3. The fuel metering apparatus as defined in claim 1 and in which said valve means comprises a housing defining a first chamber and a second chamber separated by a diaphragm, means connecting said second chamber to the intake manifold of an internal combustion engine whereby said diaphragm is actuated in response to changes in the manifold pressure of said engine, an inlet connecting said first chamber with a source of air and said outlet connected with said emulsifying well and said valve member carried by said diaphragm and operable to variably regulate air flow through said outlet in response to movement of said diaphragm. 
     
     
       4. The fuel metering apparatus as defined in claim 3 and in which said valve member extends into said outlet. 
     
     
       5. The fuel metering apparatus as defined in claim 4 and in which said valve member further comprises a tubular member open at the end toward said outlet. 
     
     
       6. The fuel metering apparatus as defined in claim 4 and in which said valve member further comprises a tubular member closed at the end toward said outlet. 
     
     
       7. The fuel metering apparatus defined in claim 1 and including a turbocharger having its compressor discharge upstream of the fuel nozzle. .Iadd. 8. A fuel metering system for an internal combustion engine, said system comprising an air induction pipe, a fuel reservoir, a fuel nozzle means fluidly connected with said fuel reservoir, a fuel/air mixing means fluidly connected with said fuel nozzle, said fuel nozzle means disposed in said air induction pipe for introducing a fuel/air mixture fuel into a stream of air flowing through said air induction pipe, means for sensing engine operation conditions,   variable valve means fluidly connected with said fuel/air mixing means, to vary the amount of air introduced into said fuel in said fuel/air mixing means, said valve means being operatively connected to and responsive to said means for sensing engine operating conditions, said valve means further comprising a housing having an interior chamber, an air inlet connected to said interior chamber and conduit means for connecting said interior chamber with said fuel/air mixing means, a portion of said conduit means adjacent said housing forming a tubular valve seat, a tubular valve member having a plurality of longitudinally spaced apertures formed therethrough, said valve member being longitudinally slidably engaged with said valve seat so that the number of apertures in the valve member open to both the interior of the valve seat and the interior chamber is dependent upon the longitudinal position of the valve member with respect to the valve seat, wherein said sensing means is connected to and controls the longitudinal position of said valve member. .Iaddend..Iadd. 9. A fuel metering system for an internal combustion engine, said system comprising an air induction pipe, a fuel reservoir, a fuel nozzle means fluidly connected with said fuel reservoir, fuel/air mixing means fluidly connected with said fuel nozzle means, said fuel nozzle means disposed in said induction pipe for introducing fuel into a stream of air flowing through said air induction pipe,   means for sensing ambient conditions, and   valve means for varying the amount of air introduced into said fuel upon a change in the ambient conditions as sensed by said ambient condition sensing means, said valve means further comprising a housing having an interior chamber, an air inlet connected to said interior chamber and conduit means for connecting said interior chamber with said fuel/air mixing means, a portion of said conduit means adjacent said housing forming a tubular valve seat, a tubular valve member having a plurality of longitudinally spaced apertures formed therethrough, said valve member being longitudinally slidably engaged with said valve seat so that the number of apertures in the valve member open to both the interior of the valve seat and the interior chamber is dependent upon the longitudinal position of the valve member with respect to the valve seat, wherein said sensing means is connected to and controls the longitudinal position of said valve member. .Iaddend. .Iadd. 10. A fuel metering system for an internal combustion engine, said system comprising an air induction pipe, a venturi throat disposed within said air induction pipe, a fuel reservoir, a fuel/air mixing means fluidly connected with said fuel reservoir, fuel nozzle means fluidly connected with said fuel/air mixing means whereby a fuel/air mixture is delivered to said fuel nozzle means, said fuel nozzle means disposed in said venturi throat for introducing said fuel/air mixture into a stream of air flowing through said air induction pipe,   means for sensing engine operating conditions,   valve means connected intermediate said air induction pipe and said air mixing means, upstream of said fuel nozzle means, to vary the amount of air introduced into said fuel in accordance with a variation in the operating conditions of said engine, said valve means further comprising a housing having an interior chamber, an air inlet connected to said interior chamber and conduit means for connecting said interior chamber with said fuel/air mixing means, a portion of said conduit means adjacent said housing forming a tubular valve seat, a tubular valve member having a plurality of longitudinally spaced apertures formed therethrough, said valve member being longitudinally slidably engaged with said valve seat so that the number of apertures in the valve member open to both the interior of the valve seat and the interior chamber is dependent upon the longitudinal position of the valve member with respect to the valve seat, wherein said sensing means is connected to and controls the longitudinal position of said valve member. .Iaddend..Iadd. 11. A fuel metering system for an internal combustion engine, said engine having an intake manifold, said system comprising an air induction pipe, fuel/air mixing means and means fluidly connecting said fuel/air mixing means with said air induction pipe, means introducing air into said fuel/air mixing means and including valve means operable when actuated to vary the rate of air delivered to said fuel/air mixing means, and means sensing changes in engine operating conditions and actuating said valve means to regulate the rate of air delivered to said fuel/air mixing means in accordance with changes in the operating conditions of said engine, said valve means further comprising a housing having an interior chamber, an air inlet connected to said interior chamber and conduit means for connecting said interior chamber with said fuel/air mixing means, a portion of said conduit means adjacent said housing forming a tubular valve seat, a tubular valve member having a plurality of longitudinally spaced apertures formed therethrough, said valve member being longitudinally slidably engaged with said valve seat so that the number of apertures in the valve member open to both the interior of the valve seat and the interior chamber is dependent upon the longitudinal position of the valve member with respect to the valve seat, wherein said sensing means is connected to and controls the longitudinal position of said valve member. .Iaddend. .Iadd. 12. The system as defined in claim 11 and in which said engine condition sensing means comprises means sensing the manifold pressure of said engine. .Iaddend. .Iadd. 13. The invention as defined in claim 11 wherein said valve member is slidably received within the interior of the valve seat. .Iaddend.