| 摘要 |
PROBLEM TO BE SOLVED: To prevent a ventilating passage from being blocked by providing a vent hole not on the threadedly fitted part of a fuel filling port to a cap but on the upper part of the cap so as to exactly obstruct invasion of rain water or wash water, and introducing only necessary air into the cap. SOLUTION: A cap main body 4 is provided with a cylindrical projecting part 7 having larger inner diameter than the outer diameter of the upper face cylindrical part 14 of a breather valve holder 6 and dome-likely swelling the upper face on the center of the upper part. A vent hole 8 is openly provided on the top part on the upper face of the projecting part 7, an umbrella shaped sub-cap 9 covering the vent hole 8 from the upper side is provided on the outer circumference of the projecting part 7, and a ventilating passage 16 communicating from the lower end of the sub-cap 9 to the top part vent hole 8 through the outer circumferential face of the projecting part 7 is provided between the projecting part 7 and the sub-cap 9. Air communication is allowed only from the upper vent hole 8 over a breather face 10, and invasion of rain water or dust can be exactly prevented. |
