Fuel vapor handling apparatus and diagnostic apparatus thereof

A fuel vapor handling apparatus comprising:

• a canister that includes a container that contains an adsorbent that adsorbs a fuel vapor from a fuel tank, the container having an atmospheric port that is open to an atmospheric pressure, a fuel vapor introducing port for connection to the fuel tank, and a purge port for connection to an intake pipe of an internal combustion engine;
• a purge pump coupled to the canister to supply air into the canister via the atmospheric port so as to purge a fuel desorbed from the adsorbent into the intake pipe via the purge port;
• a metering valve whose degree of opening is variable and which adjusts an amount of flow of the purge pump;
• and
• a controller that controls the metering valve to adjust the degree of opening of the metering valve.

A fuel vapor handling apparatus comprising:

• a canister that includes a container that contains an adsorbent that adsorbs a fuel vapor from a fuel tank, the container having an atmospheric port that is open to an atmospheric pressure, a fuel vapor introducing port for connection to the fuel tank, and a purge port for connection to an intake pipe of an internal combustion engine;
• a purge pump coupled to the canister to supply air into the canister via the atmospheric port so as to purge a fuel desorbed from the adsorbent into the intake pipe via the purge port;
• a heater that heats an interior of the canister;
• and
• a controller that controls the purge pump and the heater, to operate the heater before starting operating the purge pump.

A fuel vapor handling apparatus comprising:

• a canister that includes a container that contains an adsorbent that adsorbs a fuel vapor from a fuel tank, the container having an atmospheric port that is open to an atmospheric pressure, a fuel vapor introducing port for connection to the fuel tank, and a purge port for connection to an intake pipe of an internal combustion engine;
• a purge pump coupled to the canister to supply air into the canister via the atmospheric port so as to purge a fuel desorbed from the adsorbent into the intake pipe via the purge port;
• a refueling detecting sensor that detects whether the fuel tank has been refueled;
• and
• a controller that controls the purge pump, so that the purge pump operates when refueling is performed.

A fuel vapor handling apparatus comprising:

• a canister that includes a container that contains an adsorbent that adsorbs a fuel vapor from a fuel tank, the container having an atmospheric port that is open to an atmospheric pressure, a fuel vapor introducing port for connection to the fuel tank, and a purge port for connection to an intake pipe of an internal combustion engine;
• a purge pump coupled to the canister to supply air into the canister via the atmospheric port so as to purge a fuel desorbed from the adsorbent into the intake pipe via the purge port;
• a fuel vapor concentration sensor that is provided within a passage extending from the purge port to the intake pipe, and that detects a concentration of the fuel vapor in the passage;
• and
• a controller that controls the purge pump, so that the purge pump operates if the concentration of the fuel vapor exceeds a pre-set purge starting concentration.

A fuel vapor handling apparatus comprising:

• a canister that includes a container that contains an adsorbent that adsorbs a fuel vapor from a fuel tank, the container having an atmospheric port that is open to an atmospheric pressure, a fuel vapor introducing port for connection to the fuel tank, and a purge port for connection to an intake pipe of an internal combustion engine;
• a purge pump coupled to the canister to supply air into the canister via the atmospheric port so as to purge a fuel desorbed from the adsorbent into the intake pipe via the purge port;
• a fuel vapor concentration sensor that is provided within a passage extending from the purge port to the intake pipe and that detects a concentration of the fuel vapor in the passage;
• and
• a controller that controls the purge pump, wherein the controller computes an amount of purged fuel based on an amount of flow of a purge and a result of detection by the fuel vapor concentration sensor, and is set so that the purge pump operates if the concentration of the fuel vapor exceeds a pre-set purge starting concentration.

A canister purge system comprising:

• a canister that adsorbs a fuel vapor from a fuel tank of an internal combustion engine;
• a vapor passage that connects a space formed above a fuel liquid surface in the fuel tank to the canister;
• a purge passage that connects the canister and an engine intake passage;
• an atmospheric port that places the canister and an atmosphere in communication with each other;
• a purge pump coupled to the canister to supply a gas from the intake passage to the canister via the purge passage, the purge pump being operable independently of an operation of the engine;
• and
• a purge pump controller that supplies the fuel vapor remaining in the engine intake passage into the canister by operating the purge pump after the engine stops.