| 摘要 |
PROBLEM TO BE SOLVED: To suppress air column resonance of a duct connected to an air cleaner.SOLUTION: An air cleaner 1 includes cases 11 and 12 demarcating an extended space, and a filter element 13. An air inlet 111 and an air outlet 121 are provided in the cases. The air cleaner 1 further includes an opening end member 14 cylindrically formed by an air-permeable material. The opening end member 14 is formed in the air inlet 111 to project to an upstream side extended space SU and to extend a duct wall of the air inlet 111, and an inner peripheral side space SI and an outer peripheral side space SO of the opening end member are directly connected with each other as the upstream side extended space SU. The relationship of 0.25D≤L≤2.0D is satisfied when a diameter of the opening end member is D and a length is L, and air permeability of the air-permeable material constituting the opening end member, which is measured by a Gurley testing method, is within a range of 0.3-100 seconds/300 cc.SELECTED DRAWING: Figure 1 |
