Problem to be solved: To provide air control of a container for liquid fuel in which air pressure in the fuel container is fluctuated or a liquid level is moved by oscillation, in which an O ring wound around an outer surface of a longitudinally moving cylinder longitudinally moving in a fixed pipe to which an air pipe of an air chamber is attached does not close an air port, and there are a manual type and a cam driving type in the longitudinal movement. Solution: An air pipe of an air chamber is connected to an air port opened in a side wall, and an O ring sliding on an inner surface of a fixed pipe is wound around a longitudinally moving cylinder. The forward and backward movement of the forward and backward movable barrel is driven manually or by a cam type. The structure for moving the longitudinally...
