Patent ID: 9461580
Filing Date: 2016-10-04
CPC Classification: F01M,H02G,H02S,Y02E

Claim Text:
1. A structure for improving strength of a resin-made substantially polygonal tabular portion, wherein the polygon comprises a first axis of symmetry and a second axis of symmetry which are substantially orthogonal to each other, a top surface of the tabular portion comprises a swelling portion provided to swell upward in a region inside a polygonal outline of the tabular portion, an outline of the swelling portion is line-symmetric with respect to the first axis of symmetry and the second axis of symmetry, in a lateral half portion of the outline of the swelling portion, the swelling portion further comprises: a short-side side crest portion that is convex toward the polygonal outline in a direction of the first axis of symmetry; a corner-side trough portion that is connected to each end of the short-side side crest portion and concave toward the polygonal outline in a region sandwiched between the first axis of symmetry and the second axis of symmetry; and a long-side side crest portion that is connected to an end opposite to the short-side side crest portion of the each corner-side trough portion and convex toward the polygonal outline, and on one of a top surface and an undersurface of the swelling portion, at least: a pair of lateral ribs that transversely cross the swelling portion to spread toward the polygonal outline; or a pair of longitudinal ribs that longitudinally cross the swelling portion to spread toward the polygonal outline, are provided.