公开(公告)号：US20180257131A1

公开(公告)日：2018-09-13

申请号：US15760315

申请日：2017-07-18

Applicant: NSK LTD.

Inventor： Kouhei MORI ,  Shunichi KARASAWA ,  Mizuki WATANABE ,  Kazuto KOBAYASHI

IPC: B21K1/04 ,  F16C33/64

CPC classification number: B21K1/04 ,  B21J5/008 ,  B21J5/025 ,  B21J13/02 ,  B21K21/08 ,  B21K21/12 ,  B23P15/003 ,  F16C19/06 ,  F16C33/64 ,  F16C2220/46

Abstract: A method of manufacturing a cylindrical ring member includes a step of forming a metal intermediate material having a cylindrical portion and a chamfering step by cold forging in which a normal chamfer portion is formed on an axial end peripheral edge of the cylindrical portion by pressing a radial end portion of an axial end surface of the cylindrical portion against an annular chamfering surface provided in a mold configuring a mold device. A chamfering step is performed by cold forging in a state where a preliminary chamfer portion, of which a width dimension in a radial direction is larger than a width dimension of the normal chamfer portion in a radial direction, is formed on the axial end peripheral edge of the cylindrical portion.