Patent ID: 7322343

Claim:
A fuel vapor storage canister comprising: a casing formed thereinside with a gas passage having first and second ends which are opposite to each other, the casing having charge and purge ports for fuel vapor, the charge and purge ports being connected to the first end of the gas passage, and a drain port connected to the second end of the gas passage and opened to atmospheric air; at least first, second, third and fourth adsorption layers which are disposed in the gas passage and arranged in order of first, second, third and forth adsorption layers from a side of the charge port along a longitudinal direction of the gas passage, each adsorption layer including a fuel vapor adsorbent; and members for defining first, second and third space sections, the first space section being formed between the first and second adsorption layers, the second space section being formed between the second and third adsorption sections, the third space section being formed between the third and fourth adsorption sections, each space section having a dimension in the longitudinal direction of the gas passage, wherein the charge port of the casing is located such that the first adsorption layer is the adsorption layer first charged with fuel vapor from the charge port during charging of fuel vapor in the fuel vapor storage canister through the charge port.