Evaporative fuel emission control system
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsSusumu Kojima, Hidefumi Aikawa
Life of this patent
Estimating the term…
Abstract
An evaporative fuel emission control system includes a canister that adsorbs fuel vapor generated in a fuel tank, a canister outgoing gas producing unit that causes a canister outgoing gas to flow out of the canister, a vapor condensing unit that condenses the canister outgoing gas to provide a processed gas containing a higher concentration of fuel vapor than that of the canister outgoing gas, and a processed gas passage through which the processed gas is fed to the fuel tank. A controller of this system is operable to restrict flow of the processed gas into the fuel tank when the fuel vapor concentration in the processed gas is lower than or is expected to be lower than a predetermined level.
Claims24
An evaporative fuel emission control system for an internal combustion engine, comprising:
- a canister that adsorbs fuel vapor generated in a fuel tank;
- a canister outgoing gas producing unit that causes a canister outgoing gas to flow out of the canister;
- a vapor condensing unit that condenses the canister outgoing gas to provide a processed gas containing a higher concentration of fuel vapor than that of the canister outgoing gas;
- a processed gas passage through which the processed gas is fed to the fuel tank;
- and
- a controller that restricts flow of the processed gas into the fuel tank when the fuel vapor concentration in the processed gas is lower than or is expected to be lower than a predetermined level.
An evaporative fuel emission control system for an internal combustion engine, comprising:
- a canister that adsorbs fuel vapor generated in a fuel tank;
- a canister outgoing gas producing unit that causes a canister outgoing gas to flow out of the canister;
- a vapor condensing unit that condenses the canister outgoing gas to provide a processed gas containing a higher concentration of fuel vapor than that of the canister outgoing gas;
- a processed gas passage through which the processed gas is fed to the fuel tank;
- a bypass passage that allows communication of an upstream side of the vapor condensing unit with the fuel tank;
- a switching valve having an open state in which the bypass passage communicates the upstream side of the vapor condensing unit with the fuel tank, and a closed state in which the bypass passage is shut off;
- and
- a switching valve controller that controls the switching valve such that the switching valve is placed in the open state during stop of the canister outgoing gas producing unit, and is placed in the closed state during an operation of the canister outgoing gas producing unit.
Dependencies are inferred from the claim text.