Method of forming member, valve guide and method of forming the valve guide, and method of forming tubular member

摘要

(PROBLEMS] To provide a method with which a member having an undercut in the inner periphery can be readily formed. (MEANS FOR SOLVING PROBLEMS] To form a raw material (1) having a recess (2) and an undercut (3) by using a swaging device, the raw material (1) is gripped by a damper (11), and a mandrel (12) is inserted in the recess section (2) of the raw material (1). The mandrel (12) used has an outer diameter equal to the inner diameter of a blind hole of an aimed product (fuel injection nozzle). Then, the raw material (1) is pushed in by the mandrel (12) to a position at which the raw material is in contact with a stopper (13), and the outer surface of the raw material (1) is struck and swaged by a swaging die (8). The swaging reduces the inner diameter of the recess (2) to the magnitude of the outer diameter of the mandrel (12), with the undercut (3) left.