Apparatus and method for periodically cleaning a charcoal canister and for periodically checking leak-tightness of a fuel system of an internal combustion engine
First Claim
1. Apparatus for cleaning a fuel vapor canister and for testing tightness of a fuel tank unit of an internal combustion engine of a motor vehicle, said engine having an air intake system containing a choke valve, said apparatus comprising:
- a line connected to the air intake system upstream of the choke valve,a reversible electric air pump in said line,said canister being connected to said line so that in one direction of pumping by said air pump, ambient atmospheric air flows through said canister to the air intake system to clean the canister, andsaid fuel tank unit being connected to said line for being supplied with air from said intake system when said air pump is operated in the other pumping direction to pressurize the fuel tank unit while the canister is isolated from said line.
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Accused Products
Abstract
A method and apparatus for periodically air-washing a charcoal canister and for testing leak-tightness of a closed fuel supply system of an internal combustion engine in which a reversible electric air pump is installed in a line connecting the fuel system and the canister to the intake manifold of the engine upstream of the choke valve. In one direction of operation of the pump, ambient air is sucked through the canister and fed to the intake manifold to wash the canister and in the other direction of operation of the pump, air is pumped from above the choke valve in the intake manifold to the fuel system to pressurize the system to check leak-tightness thereof. When the engine is turned off, the pump is shut off and the fuel supply system is connected to the canister.
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Citations
12 Claims
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1. Apparatus for cleaning a fuel vapor canister and for testing tightness of a fuel tank unit of an internal combustion engine of a motor vehicle, said engine having an air intake system containing a choke valve, said apparatus comprising:
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a line connected to the air intake system upstream of the choke valve, a reversible electric air pump in said line, said canister being connected to said line so that in one direction of pumping by said air pump, ambient atmospheric air flows through said canister to the air intake system to clean the canister, and said fuel tank unit being connected to said line for being supplied with air from said intake system when said air pump is operated in the other pumping direction to pressurize the fuel tank unit while the canister is isolated from said line. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. In a method of absorbing, in a charcoal canister, fuel vapor from a closed fuel system of an internal combustion engine, the improvement comprising:
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periodically washing the canister with ambient atmospheric air and periodically checking leak-tightness of the fuel system by, periodically operating a reversible electrically driven pump in one direction of operation to force ambient atmospheric air to flow through the canister to wash the canister, and periodically operating the electrically driven pump in an opposite direction of operation to pressurize the fuel system to determine the leak-tightness of said system. - View Dependent Claims (9, 10, 11, 12)
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Specification