Patent ID: 8365756

Claim:
A fuel tank valve device provided in a ventilation path communicating an inside and an outside of a fuel tank, comprising: a valve body having a circular plate shape and including an upper part, a circular projection projecting downwardly from the upper part, a plurality of leg portions extending downwardly from a periphery of the upper part, and a plurality of windows formed in the upper part corresponding to the leg portions; a float body provided with the valve body on an upper portion; a housing chamber which is formed in the ventilation path and houses the float body to be movable upward and downward; and a valve seat which is formed in the ventilation path and closes a valve by receiving a seating of said valve body by an ascent of the float body due to an inflow of fuel to the housing chamber, wherein the valve body and the float body are coupled so that the valve body moves in a direction along a central axis of movement of the float body and also the valve body becomes unseated when the float body descends, a pair of guide means is provided on a central axis side of the movement of the float body, and when the valve body tilts, the valve body and the float body contact each other at a lower side of a tilt of the valve body so that the guide means correct the tilt by the ascent of the float body, and when the float body ascends, the float body and the valve body do not contact each other except for a portion where the valve body and the float body contact each other.