| 摘要 |
PROBLEM TO BE SOLVED: To secure satisfactory scilence in a room by remarkably reducing noises during operation with a low cost. SOLUTION: An air pump is composed of an electromagnet, a diaphragm 4 which is contracted and expanded interlockingly with oscillation of an oscillation arm 3 operated by electromagnetic function of the electromagnet, and a casing 5 which houses each part. In such an air pump, a suction side noise absorbing chamber 11 for passing the air to be supplied into the diaphragm 4 and a discharge side noise absorbing chamber 12 for passing the air fed from the diaphragm 4 are formed inside the casing 5. An air passage tube 13b is projected in at least one of the chambers 11 and 12. A bottomed coating pipe 14b whose one end only is opened is loosely fitted to the outside of the air passage tube 13b through an air passage. |
