| 摘要 |
PURPOSE:To eliminate an energizing means for an inner peripheral lip part and 8 valve plate and to reduce the number of parts and the number of assembling processes, by a method wherein the inner peripheral lip part of a fuel cap forms a valve body made of a rubbery resilient material. CONSTITUTION:After a fuel cap 21 is mounted to a filler neck, at a usual time, an outer peripheral lip part 23e if a valve body is brought into pressure contact with an annular projected part 22 of a cap body by means of a spring energizing means 26, an inner peripheral lip part 23c of the valve body is brought into pressure contact with a seal part 24b of a valve body holding plate 24 through the elasticity of a valve body 23, and a fluid flow passage in a cap body 22 is closed by means of the valve holding plate 24 of the valve body 23. When the interior of a tank is brought into a negative pressure sate exceeding a given value, the inner peripheral lip part 23c of the valve body is separated away from a seal part 24b of the valve body holding plate 24 against the elasticity of the valve body 23, the fluid flow passage is released from closing, and a negative pressure state in the tank is rendered ineffective.
|
