Opening/closing apparatus for fuel tank

An opening/closing apparatus for a fuel tank of a vehicle, the opening/closing apparatus comprising:

• a fuel passage forming portion that forms a fuel passage configured to guide a supplied liquid fuel to the fuel tank;
• an insertion-side opening/closing valve mechanism that is disposed in the fuel passage forming portion, and that is configured to open and close a filler port of the fuel passage;
• a fuel tank-side opening/closing valve mechanism that is disposed in a portion of the fuel passage forming portion, the portion closer to the fuel tank than the insertion-side opening/closing valve mechanism, the fuel tank-side opening/closing valve mechanism that is configured to open and close the fuel passage;
• a liquid discharge path that is configured to allow an internal region of the fuel passage forming portion to communicate with the outside of the opening/closing apparatus through a liquid discharge port formed in the fuel passage forming portion between the insertion-side opening/closing valve mechanism and the fuel tank-side opening/closing valve mechanism;
• and
• an opening/closing valve mechanism that is configured to open and close the liquid discharge port by a valve body disposed in the fuel passage forming portion, and that includes a moving body which is movable from a first position where a closing force exerts on the valve body to close the liquid discharge port to a second position where the closing force decreases, the moving body which is positioned at the first position in a state where the vehicle is stopped, and which is configured to move from the first position to the second position when receiving an inertial force due to traveling of the vehicle.