| 摘要 |
PROBLEM TO BE SOLVED: To eliminate a negative pressure produced due to the decrease of an external air temperature and prevent a shrinkage crack of a wall of a tank due to the negative pressure from being developed, by providing a pressure regulating valve in a pressure release stopper of the tank. SOLUTION: A pressure regulating valve 10 is provided in a pressure release stopper 3. The pressure regulating valve 10 is operated when a negative pressure is produced in a tank 1 by the shrinkage of liquid fuel contained in the tank 1 due to the decrease of an external air temperature under the condition that the pressure release stopper 3 is in a closed state. That is, a valve disc 14 is pushed down against a compression coil spring 15 by an ambient air pressure and opens an external air introducing passage 12. An external air inlet port 11 is thereby allowed to communicate inside the tank 1 through an air discharge passage 6, and the external air is sucked into the tank 1. As a result, the interior of the tank 1 is maintained in the same air pressure as the ambient air pressure to prevent a crack flaw from being developed on the wall face of the tank. When the air pressure in the tank 1 becomes the same as the ambient air pressure, the valve disc 14 is pressed against a valve seat 13 by the compression coil spring 15 to close the external air introducing passage 12, thus quickly checking gasified fuel in the tank 1 from leaking. |
