Abstract: A lower wall (8) forming a fuel storage chamber (5) becomes curved downward according to increase of the fuel amount, and at this time a support member (23) for supporting the fuel storage chamber (5) does not restrain the downward curvature of the lower wall (8), whereby the capacity of the fuel storage chamber (5) can be increased and whereby the amount of the fuel that can be stored in the fuel storage chamber (5) can be maintained at the maximum, as compared with structure inhibiting deformation of the lower wall (8).

Abstract: A lower wall partially defining a fuel storing chamber of a fuel tank curves upward in accordance a decrease in an amount of fuel stored in the fuel storing chamber. The volume of a gaseous space in the fuel storing chamber is reduced, in comparison with a fuel tank in which a lower wall does not deform, by an amount corresponding to a reduction of the volume of the fuel storing chamber achieved by the curvature of the lower wall. An amount of fuel not discharged from the fuel storing chamber via a fuel passage but remaining near a peripheral end portion of the lower wall of the fuel storing chamber due to the upward curvature of the lower wall is discharged via a residual fuel discharging pipe, so that the residual fuel amount of the fuel storing chamber is minimized.

Abstract: A lower wall (8) forming a fuel storage chamber (5) becomes curved downward according to increase of the fuel amount, and at this time a support member (23) for supporting the fuel storage chamber (5) does not restrain the downward curvature of the lower wall (8), whereby the capacity of the fuel storage chamber (5) can be increased and whereby the amount of the fuel that can be stored in the fuel storage chamber (5) can be maintained at the maximum, as compared with structure inhibiting deformation of the lower wall (8).

Abstract: A fuel vapor recovery apparatus has a canister for adsorbing fuel vapor generated in a fuel chamber formed in a fuel tank. A fuel vapor inlet of the canister is connected to the fuel chamber. A fuel vapor outlet of the canister is connected to an intake passage of an internal combustion engine. Fuel vapor adsorbed by the canister is purged therefrom into the intake passage. An air vent of the canister is connected to an air chamber that has a predetermined capacity.

Abstract: A lower wall (8) forming a fuel storage chamber (5) becomes curved downward according to increase of the fuel amount, and at this time a support member (23) for supporting the fuel storage chamber (5) does not restrain the downward curvature of the lower wall (8), whereby the capacity of the fuel storage chamber (5) can be increased and whereby the amount of the fuel that can be stored in the fuel storage chamber (5) can be maintained at the maximum, as compared with structure inhibiting deformation of the lower wall (8).