FORMING DIE, FORMING METHOD, AND FORMED PRODUCT FOR EXTERNAL TOOTH PROFILE COMPONENT

摘要

PROBLEM TO BE SOLVED: To precisely form external tooth profile components, which have a variety of shapes, by upsetting. SOLUTION: In the early stage of a leading process, the flow of material is promoted by concentrating a load on a contact portion of an annular projection 6a of a punch 601 for the leading process with an annular blank 1 while preventing the increase of working surface pressure applied to a die. Because a forming surface of a punch 602 for the following process has a small annular projection 6a' smaller than the annular projection 6a of the punch 601 for the leading process, the small annular projection 6a' of the punch 602 for the following process is inserted with a clearance S into the annular groove 5c formed in the annular blank 1 by the annular projection 6a of the punch 601 for the leading process. The clearance S functions as a recess for run off. Thus, the charge of material into an external tooth profile forming surface 8a of the die 8 can be promoted while preventing the increase in working surface pressure on a forming die 4. COPYRIGHT: (C)2004,JPO