US 6,318,345 B1 · Purge vapor start feature

Abstract

A fuel control system is provided including a fuel tank and a purge vapor collection canister interconnected with an internal combustion engine. A purge vapor canister vent valve selectively seals the purge vapor canister from atmosphere such that the fuel tank, purge vapor canister, and engine intake manifold form a closed system. Upon a cold engine start, a purge valve disposed between the purge vapor canister and the engine intake manifold is opened such that the pressure differential between the engine intake manifold and the remainder of the system causes fuel vapor collected within the dome portion of the fuel tank to be drawn through the purge vapor canister and into the intake manifold. Simultaneously therewith, the amount of fuel injected by the fuel injectors to the engine is reduced such that a desired amount of total fuel delivery is established. As the pressure differential between the intake manifold and the remainder of the closed system changes over time, flow rate of purge vapors from the fuel tank slows down. Commensurate therewith, the amount of injected fuel is increased. During this time the engine is warming up such that the increased amount of injected fuel is more easily vaporized thereby yielding better combustibility. When the engine reaches a fully warm operating condition, the purge vapor valve is closed and complete fuel delivery is provided by the fuel injectors.

Claims16

Dependent claims

A method of fueling an internal combustion engine comprising:

determining a cold engine operating condition to exist;
delivering a first quantity of fuel consisting of fuel vapors from a dome portion of a fuel tank to said engine for combustion during said cold engine operating condition;
and
delivering a second quantity of fuel consisting of liquid fuel from a fuel injection system to said engine for combustion with said fuel vapors during said cold engine operating condition, said second quantity of fuel being proportional to said first quantity of fuel such that a desired total quantity of fuel is delivered to said engine.

1 more element

A method of fueling an internal combustion engine comprising:

providing a fuel vapor purge system including:
a fuel vapor purge canister interconnected to said engine by a purge line;
a purge valve disposed on said purge line;
a vent line coupled to said fuel vapor purge canister and communicating with atmosphere;
a vent valve disposed on said vent line;
and
a fuel tank interconnected to said fuel vapor purge canister by a vapor line;
detecting a start-up event of said engine;
closing said vent valve on said vent line to isolate said fuel tank from atmosphere;
opening said purge valve on said purge line to establish a pressure difference between said engine and said fuel tank;
drawing fuel vapors from said fuel tank through said vapor line, fuel vapor purge canister, and purge line to said engine;
monitoring an amount of said fuel vapors drawn to said engine;
injecting an amount of fuel to said engine commensurate with said amount of said fuel vapors drawn to said engine;
and
combusting said fuel vapors and said injected fuel in said engine.

12 more elements

Dependencies are inferred from the claim text.

Purge vapor start feature

Life of this patent

Purge vapor start feature

Life of this patent

Abstract

Claims16