Fuel mixture enrichment system for internal combustion engine
AssigneeEmerson Electric Co.
InventorsLloyd H. Tuggle, Michael J. Ferlito
Life of this patent
Estimating the term…
Abstract
A fuel priming system for spark ignited internal combustion engines includes a manually actuated plunger pump for delivering liquid fuel from a tank to a reservoir chamber formed in part by a flexible diaphragm. A fuel injection passage leads from the reservoir chamber through a flow restricting orifice to an injection point formed in the engine intake air flow passage downstream of the carburetor venturi. The injection system provides for enriching the fuel-air mixture during cold starting while minimizing the chance of engine flooding. The finite fuel volume in the reservoir chamber also provides a sufficient quantity of fuel for automatic control of a rich fuel-air mixture during engine warm-up.
Claims46
A fuel-air mixture enriching system for starting an internal combustion engine, said engine including a carburetor having air flow passage means therein, and a throttle valve disposed for throttling air flow through said carburetor, and further passage means interconnecting said carburetor air flow passage means with a combustion chamber of said engine, a source of liquid fuel, and means interconnecting said fuel source with said carburetor, said mixture enriching system comprising:
- means forming a reservoir chamber having a predetermined volume in communication between said fuel source and one of said plurality of passage means, pump means for delivering fuel to said reservoir chamber prior to cranking of the engine, and conduit means for conducting fuel from said reservoir chamber into said one passage means responsive to a lower pressure developed in said air passage means by reciprocation of the piston to provide an enriched fuel-air mixture for induction into said combustion chamber during a starting cycle of said engine.
A fuel-air mixture enriching system for an internal combustion engine, said engine including cylinder means including a combustion chamber, rotatable crankshaft means, means for rotating said crankshaft means to start said engine, and a throttle body including passage means in communication with further passage means in said engine for conducting a fuel-air mixture into said combustion chamber;
- said mixture enriching system including:
- means forming a reservoir chamber for holding a predetermined quantity of liquid fuel;
- conduit means in communication with one of said plurality of passage means and said reservoir chamber for conducting fuel to said one passage means;
- a manually actuated pump for filling said reservoir chamber with a predetermined charge of fuel;
- and
- means for reducing the volume of said reservoir chamber for controlling the quantity of fuel injected into said one passage means in response to induction of fuel into said one passage means on starting said engine.
A fuel supply system for an internal combustion engine, said engine including throttle body means having air flow passage means therein, a throttle valve disposed for throttling air flow through said throttle body passage means, means forming further passage means interconnecting said throttle body passage means with a combustion chamber of said engine, and a source of liquid fuel;
- said fuel supply system comprising:
- means forming a separate reservoir chamber in communication with said fuel source and one of said plurality of passage means, means for delivering a predetermined quantity of fuel to said one passage means through said reservoir chamber to prime said engine during a starting cycle, and means for controlling the flow of a predetermined quantity of fuel from said reservoir chamber into said one passage means to provide an enriched fuel-air mixture to said engine upon starting said engine.
A portable internal combustion engine power unit for a power tool, said power unit including a spark ignited internal combustion engine including means defining a combustion chamber, a carburetor, passage means including a venturi in said carburetor in communication with said combustion chamber, said carburetor being oriented on said engine in a normal working position to place said venturi in an updraft configuration;
- and
- a fuel priming system for injecting a quantity of liquid fuel into said passage means including means forming a separate fuel reservoir chamber, conduit means interconnecting said reservoir chamber with a source of liquid fuel, and conduit means interconnecting said reservoir chamber with said passage means in said engine at a point which will permit excess fuel to drain out of said passage means in said normal working position of said engine to prevent entrainment of said fuel in air flowing to said combustion chamber, said priming system being operable in response to cranking said engine to induct fuel from said reservoir chamber into said passage means to substantially evacuate said reservoir chamber so that a predetermined limited quantity of fuel is inducted into said combustion chamber during an engine starting cycle.
A portable internal combustion engine power unit for a power tool, said power unit including a spark ignited internal combustion engine including means defining a combustion chamber, a carburetor, fuel-air mixture flow passage means in communication with said carburetor and said combustion chamber, a fuel tank, and a fuel supply system for injecting a quantity of liquid fuel into said passage means,
- said fuel supply system including means forming a separate fuel reservoir chamber, first conduit means interconnecting said reservoir chamber with said fuel tank, and second conduit means interconnecting said reservoir chamber with said passage means,
- a manually actuated pump interposed in said first conduit means between said fuel tank and said reservoir chamber, said pump being operable at will to deliver a predetermined quantity of fuel to said passage means through said reservoir chamber to prime said engine for starting,
- said fuel supply system being responsive to starting said engine to conduct a predetermined quantity of fuel from said reservoir chamber into said passage means to provide a relatively rich fuel-air mixture to said combustion chamber during an engine warm-up period.
A fuel priming system for an internal combustion engine, said engine including means defining a combustion chamber, fuel-air mixture flow passage means in communication with said combustion chamber and a fuel tank, said fuel priming system including:
- a manually actuated plunger pump interposed in conduit means between said tank and said passage means and being operable at will for delivering a predetermined quantity of fuel through said conduit means in response to manual actuation of plunger means, said pump including a main body portion including a bore for receiving said plunger means and defining a chamber through which said plunger means traverses to displace said predetermined quantity of fuel, and means operable to prevent unrestricted flow of fuel from said fuel tank and through said pump when said pump is actuated.
The combination comprising:
- an internal combustion, reciprocating piston engine having an induction air passageway in which a subatmospheric pressure is developed when the piston is reciprocated;
- a fuel tank for holding a supply of fuel;
- a fuel reservoir holding a predetermined volume of fuel;
- a conduit communicating from the reservoir through a metering orifice to the induction air passageway;
- pressure compensating means for allowing fuel in the reservoir to be drawn from the reservoir through the metering orifice into the induction air passageway by subatmospheric pressure in the passageway resulting from reciprocation of the piston;
- manually operable pump means for at will delivering a predetermined volume of fuel during each stroke from the fuel tank to the reservoir and to the metering orifice, the pump means including means for bypassing a portion of the fluid during each delivery stroke after the reservoir has been filled and fluid is being forced only through the metering orifice whereby the reservoir can be filled with a predetermined number of strokes and the lesser volumes of fuel delivered during successive strokes permits the use of multiple strokes to cover a wider range of engine temperature and climatic conditions with greater precision.
The combination comprising an internal combustion engine having a normal starting orientation with respect to the force of gravity,
- a fuel tank,
- induction air passageway means including carburetor means for carbureting fuel into the induction air during normal operation of the engine and valve means for admitting the fuel air mixture to the engine,
- a pump operated by pressure derived from stroking of the piston for pumping fuel from the tank to the carburetor,
- manually operable pump means for pumping fuel from the fuel tank to a section of the intake air passageway means between the air filter and valve means while bypassing the engine operated fuel pump, said section being oriented with respect to the force of gravity when the engine is in the normal starting position such that excess fuel drains by gravity away from the engine to provide fuel for initially starting the engine, and
- means for preventing the collection of excess fuel in the passageway other than a wetting of predetermined surfaces to provide a reproductable fuel-air mixture for starting the engine even in the event of excess operation of the manually operable pump means.
The combination comprising an internal combustion, reciprocating piston engine having a normal starting orientation with respect to the force of gravity including induction air passageway means for directing induction air to the engine, carburetor means for carbureting fuel into the induction air during normal operation, a fuel tank, manually operable pump means for pumping fuel from the fuel tank and injecting fuel in a section of the induction air passageway, said section being oriented with respect to the force of gravity when the engine is in the normal starting position such that excess fuel drains by gravity away from the engine, and drainage means for preventing accumulations of fuel other than wetting of the walls of a predetermined section of the passageway to provide an appropriate fuel-air ratio for starting the engine while limiting the potential for flooding.
Dependencies are inferred from the claim text.