Crimp securing structure of bolt, crimp securing method for crimp bolt, and crimping die

Abstract

Provided is a crimp securing structure of a bolt in which a crimp bolt 10 having a crimping recess 13 on the upper surface of the head is crimped onto a metal sheet 30. The thickness of a metal material press-fitted into the crimping recess 13 of the crimp bolt is made smaller at the peripheral edge of the crimping recess 13 and is made larger in the center portion thereof. In order to obtain this crimp securing structure, a crimping die 20 in which a stress-relief recess 23 is formed in a center portion of a convex portion is used to prevent the occurrence of excessive local stress in the crimping recess 13.

Dependencies are inferred from the claim text.