| 摘要 |
PROBLEM TO BE SOLVED: To make suction and exhaust executable smoothly anytime without making an air exhaust passage blocked with contents. SOLUTION: A fitting indent 8 is provided at the inside of a lid body 6, an air induction passage 13 is provided at the fitting indent 8 and an air exhaust passage 16' is opened at a valve seat 15 around the fitting indent 8, an elastic valve plate 17 of a valve disc 9 fixed to the fitting indent 8 so as to move vertically is stuck close to the valve seat 15, the air exhaust passage 16' is closed with the valve plate 17, a lip part 17a of the valve plate 17 is elastically deformed and separated from the valve seat 15 when the internal pressure decreases, and the lip part 17a is separated from the valve seat with the valve plate 17 fitted into the fitting indent 8 when the internal pressure increases. |
