| 摘要 |
PURPOSE:To prevent the generation of a beating sound by forming a passage to the open air connected to a large air pressure chamber into one having certain inside diameter and length that display a dynamic damper effect. CONSTITUTION:A positive pressure valve A has a valve chamber 2, which is connected to a first connecting port 1a through an air passage 1c, and a diaphragm 4, which partitions a large air pressure chamber 3 at the back of the valve chamber 2. A valve body 6, which closes a valve port 5 connected to the valve chamber 2, is interlocked with the diaphragm 4. By making an open air passage 14 connected to the large air pressure chamber 3, one having certain inside diameter and length, the vibrating energy of the diaphragm 4 is absorbed by a dynamic damper effect due to the air which is let in and out, suppressing the diaphragm 4 from resonating. Thereby, an effect to silence beating sound can be obtained. |
