| 摘要 |
PURPOSE:To prevent emission of vaporized fuel to the atmosphere, when a fuel tank is not used, by suppressing breathing action of a breather device before internal pressure of the fuel tank reaches preset pressure. CONSTITUTION:A breather port 9 is communicated to an air layer (a) formed in the upper part of a tank 1, and opened to an upper wall 1a' of the enclosed fuel tank 1, then the first breather pipe 13, communicated to the atmosphere, is connected to this breather port 9. While a relief valve R, opened to permit emission of vaporized fuel if pressure in the tank 1 exceeds a prescribed value, is interposed in a half way of the pipe 13. Then a device is constituted in such a manner that when the tank 1 is not used, breathing action is suppressed before internal pressure reaches preset pressure. In this way, the inside of the tank 1, at no use of fuel, is placed under a completely air-tight condition before reaching the set pressure to both suppress vaporization of fuel and prevent ceaseless emission of fuel to the atmosphere, and an after-process of vaporized fuel can be easily performed. |
