| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative pressure pump the cost of which is suppressed with simple structure, and which also can muffle exhaust sound from a pump part.SOLUTION: There is provided in a pump part 80, exhaust outlets 97, 98 on a side surface 112 opposite to the side which is in contact with a body part 30, a rib 64 projected to the pump part 80 side is integrally formed on a bottom part 56 of a cover body 50 and a chamber 66 with which the surrounding of the exhaust outlets 97, 98 is covered is formed by the rib 64. The chamber is provided near the exhaust outlets and, thereby, muffling effect of the exhaust sound can be obtained by the chamber. In addition, only the rib is integrally formed on the bottom part of the cover body and, therefore, the chamber which muffles the exhaust sound can be formed with simple structure. That is, the cost is suppressed by virtue of the simple structure and, moreover, the exhaust sound from the pump part can be muffled. |
