| 摘要 |
PROBLEM TO BE SOLVED: To provide fitments capable of preventing a ventilation valve from sticking on a ventilation passage because of a water droplet not to swing into a facedown attitude with its own weight.SOLUTION: There are provided fitments which open and close a ventilation passage 30 of an upper horizontal frame material 10 with a ventilation valve 40. The ventilation valve 40 swings facedown with its own weight to close the ventilation passage 30, and swings faceup with differential pressure of air pressure to open the ventilation passage 30, and a projection part 44 is provided on the ventilation valve 40 and comes into contact with the ventilation passage 30 when the ventilation valve faces up most to prevent a water droplet from staying, thereby ventilation valve from sticking on the ventilation passage because of the water droplet not to swing face down with its own weight. |
