Internal-combustion engines – Charge forming device – Having fuel vapor recovery and storage system
Reexamination Certificate
2000-06-16
2001-11-27
Moulis, Thomas N. (Department: 3747)
Internal-combustion engines
Charge forming device
Having fuel vapor recovery and storage system
C055S385300
Reexamination Certificate
active
06321726
ABSTRACT:
TECHNICAL FIELD
The present invention relates generally to fuel systems and more particularly to a canister for adsorbing fuel vapors in a fuel system.
BACKGROUND
Fuel evaporative control systems are typically used in automobiles to prevent fuel tank vapors from entering the atmosphere. Fuel vapors are typically generated when fuel is introduced into a fuel tank, or when fuel sloshes or splashes in a fuel tank as a result of road conditions or vibrations, or operator driving dynamics.
Contained within the evaporative control systems are carbon canisters. The carbon canisters trap fuel vapor when an engine is not running. The canisters are filled with activated charcoal granules that are capable of adsorbing fuel vapors.
When the engine of an automobile is running, the intake manifold vacuum acts on the charcoal canister purge line. This causes fresh air to flow through the filter and into the canister. The fresh air picks up the stored fuel vapors and carries them through a fuel vapor line. The vapors enter the intake manifold and are introduced into the combustion chambers for ignition with injected fuel.
Typically, as described above, carbon canisters are filled with pelletized or granular carbon. Pressure is applied against a bed compression plate, using a coil or spring leaf spring or springs to maintain carbon bed integrity, as the bed tends to compact during its useful life. Molded-in spring posts are typically used to hold the springs or coils within the canister.
One problem with typical carbon canister constructions is that the carbon canisters are made of molded plastic and the bed compression plates are made of of metal. Due to the difference in materials, the canister and plate expand and contract at different rates, creating the possibility that the carbon granules or pellets may leak.
Another problem with typical carbon canister constructions is that the molded-in spring posts are difficult to manufacture. These posts are difficult to mold into acceptable shapes and sizes, and also require long cure cycle times.
Further, the current designs of carbon canisters require a complicated support structure to maintain the carbon bed integrity. Springs, such as a strip leaf spring, or coils welded to the bottom of the bed apply pressure to the bed compression plates to maintain carbon bed integrity, as the bed tends to compact during its useful life.
It is thus highly desirable to limit or eliminate carbon pellet leakage resulting from expansion or contraction of the carbon canister relative to the bed compression plate.
It is also highly desirable, from a design and manufacturing standpoint, to simplify the design of the carbon canister systems by eliminating molded-in spring posts and to limit the amount of parts used for maintaining carbon bed integrity.
SUMMARY OF THE INVENTION
It is thus one object of the present invention to limit or eliminate carbon pellet leakage resulting from expansion or contraction of the carbon canister relative to the bed compression plate.
It is another object of the present invention to simplify the design of the carbon canister systems by eliminating molded-in spring posts and to minimize the number of parts used for maintaining carbon bed integrity.
The present invention simplifies the design of a carbon canister assembly by combining the bed compression plate and spring into one single part. This new design aids in the manufacturing of the carbon canister by simplifying the molding of the carbon canister due to the elimination of the molded in spring post. The new design provides constant mechanical pressure on the carbon bed within the canister over the life of the vehicle.
Other objects and advantages of the present invention will become apparent upon considering the following detailed description and appended claims, and upon reference to the accompanying drawings.
REFERENCES:
patent: 3348692 (1967-10-01), Balogh
patent: 3411629 (1968-11-01), Wilber et al.
patent: 3730158 (1973-05-01), St. Amand
patent: 3870492 (1975-03-01), Guild
patent: 4306894 (1981-12-01), Fukami et al.
patent: 4381929 (1983-05-01), Mizuno et al.
patent: 4758255 (1988-07-01), Yamada et al.
patent: 4986840 (1991-01-01), Mori et al.
patent: 5098453 (1992-03-01), Turner et al.
patent: 5122172 (1992-06-01), Sherwood et al.
patent: 5174938 (1992-12-01), Ito et al.
patent: 5718209 (1998-02-01), Scardino et al.
patent: 5779773 (1998-07-01), Cam et al.
Clancy Dawn
Dimitrievski Ljupco
Goebel Thomas
Khami Roger
Kajander John E.
Moulis Thomas N.
Visteon Global Technologies Inc.
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