| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a hard disk drive aluminum alloy cover allowing thinning to less than 0.5 mm thick and still capable of keeping rigidity of the cover from decreasing. <P>SOLUTION: A hard disk drive cover 1 is formed of an aluminum alloy thin plate into a tray-shape. The hard disk drive cover 1 has a surface including: a stepped portion 2 formed in a center of the cover 1 and being circular in a planar shape; a concave stepped portion 3 spread in a periphery of the circular convex stepped portion and being arc-like in the planar shape; and a flat portion 4 arranged in a periphery of the arc-like concave stepped portion 3. Furthermore, a plurality of stepped portions 6 are interspersed around an arc-like periphery of the arc-like concave stepped portion 3 with intervals therebetween over a circumferential direction thereof. <P>COPYRIGHT: (C)2012,JPO&INPIT |
