| 摘要 |
A processing method of a pivot axis assembly hole in a pivot lever for wiper is provided to prevent a hardened surface being formed on the boundary surface of the assemblage hole, thereby increasing the engagement area between the assembly hole and the serration part of the pivot axis. A processing method of a pivot axis assembly hole in a pivot lever for wiper is as follows. A temporary hole(2) is processed on a plate(11), and an assemblage hole is formed through hole expansion processing. A hardened portion formed on the periphery of the hole in the hole expansion processing is removed. The hole forming and expansion processes use a lower mold with a punching hole and a punch located above the punch hole. |
