Controlling evaporative emissions in a fuel system
AssigneeWalbro Engine Management, L.L.C.
InventorJohn C. Woody
Life of this patent
Estimating the term…
Abstract
Methods and fuel systems to reduce evaporative emissions of a volatile fuel. A fuel tank contains fuel, a carburetor mixes air with the fuel from the fuel tank, and a plurality of fluid paths route fuel amongst and/or between the fuel tank and the carburetor. A valve actuation device stops flow of fuel in one or more of the plurality of fluid paths and the carburetor is adapted to be drained of fuel during engine shutdown to reduce or prevent evaporative emissions from the fuel system. The carburetor is preferably designed so as to minimize a volume of fuel contained therein.
Claims11
A fuel system for supplying fuel to an internal combustion engine with a crankshaft and a crankcase, the fuel system comprising:
- a fuel tank for containing fuel therein;
- a carburetor having a fuel bowl in fluid communication with the fuel tank by at least one fluid path at least when the engine is operating;
- a valve in fluid communication between the fuel tank and the fuel bowl of the carburetor constructed to prevent flow of fuel into the carburetor, at least when the internal combustion engine is not operating;
- a pump in fluid communication with the fuel bowl of the carburetor to pump fuel out of the carburetor, substantially during shutdown of the internal combustion engine, and
- the pump communicating with the crankcase of the engine and being actuated by pressure pulses produced in the crankcase by the engine when the crankshaft is rotating.
A fuel system for supplying fuel to an internal combustion engine with an intake, a crankshaft and a crankcase, the fuel system comprising:
- a fuel tank for containing fuel therein;
- a carburetor elevated with respect to the fuel tank and in fluid communication therebetween by at least one fluid path;
- at least one valve in fluid communication between the fuel tank and the carburetor, the at least one valve constructed to prevent flow of fuel into the carburetor and permit flow of fuel away from the carburetor, at least when the internal combustion engine is not operating;
- a pump in fluid communication with the carburetor to pump fuel to the carburetor substantially during startup and operation of the internal combustion engine, and
- the pump communicating with one of the crankcase or intake of the engine and actuated by pressure pulses produced therein by the engine when the crankshaft is rotating and removing fuel from the carburetor when the engine is not operating.
A fuel system for supplying fuel to an internal combustion engine with an intake, a crankshaft and a crankcase, the fuel system comprising:
- a fuel tank for containing fuel therein;
- a carburetor having a fuel bowl in fluid communication with the fuel tank by at least one fluid path at least when the engine is operating;
- a valve in fluid communication between the fuel tank and the fuel bowl of the carburetor to prevent flow of fuel into the carburetor at least when the engine is not operating;
- an accumulator pump in fluid communication with the fuel bowl of the carburetor to remove fuel from the fuel bowl carburetor substantially during shutdown of the engine;
- and
- the accumulator pump communicating with one of the crankcase or the intake of the engine and actuated by pressure pulses produced therein by the engine when the crankshaft is rotating.
Dependencies are inferred from the claim text.