| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a metallic short fiber from falling off while keeping the thickness of a filter as small as possible in the filter made by laminating two kinds of metallic short fiber filters; and to prevent the filter from being mounted in an opposite direction by mistake.SOLUTION: A filter 44 includes: a first filter layer 51 made by sintering first metallic short fibers 50a having a polygonal cross section; a second filter layer 52 laminated on the first filter layer 51 and made by sintering second metallic short fibers 50b having a circular cross section; and a third filter layer 53 laminated on the second filter layer 52. The third filter layer 53 is not laminated on the first filter layer 51, and the surface of the first filter layer 51 opposite to the second filter layer 52 is exposed.</p> |
