| 摘要 |
<p>PURPOSE:To eliminate the resonance of a lid by providing a rib on the side of the lid or of a main body, and by providing a cushion at a certain interval between the front end and the counter part of the rib, so as to abut the lid side on the main body side through the cushion when required. CONSTITUTION:When an air stream flows in from an inlet port 18 into a main body 11, fine dust in the air is charged by a discharging device 19, and is absorbed by an electrostatic charged filter of a filter 20. The clean air than has passed through the filter 20 flows from a suction port 17 as well as a vent hole 17' into a vortex chamber 27, and is discharged from an air outlet 28 to the outside by a fan 12. A flat lid 29 is resonated, in particular, due to the vibration caused by driving. A cushion 30 is supported on the front end by a support rib 26 of the filter 20 in such a way that it is protruded to the side of the lid 29, while a gap is formed between them. Since the lid 29 is abutted on the cushion 30 when the resonance starts, the resonance is eliminated by changing the resonance frequency of the lid.</p> |
