| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a burring structure by which breakdown torque is made large, and to obtain a method for manufacturing the burring structure. <P>SOLUTION: At an outer peripheral surface 14A of a standing wall 14 of the burring structure 10, a portion of an inner peripheral surface 14B of the standing wall 14 is formed as a concave recessed part such that a plurality of rib parts 16 are formed to reach from a base end part of the outer peripheral surface 14A of the standing wall 14 to an apical part thereof. Furthermore, from the base end part of the outer peripheral surface 14A to the apical part thereof, a cross sectional area of the rib parts 16 gets continuously smaller. Accordingly, the burring structure by which the breakdown torque is made large can be obtained. <P>COPYRIGHT: (C)2013,JPO&INPIT |
