Press device, and method of manufacturing elliptical-cylindrical member

A method of manufacturing an elliptical-cylindrical member using a flat metal stock, the method comprising:

• preparing a first die having a shape of elliptical cylinder, a second die having a first recess that forms a part of an elliptical-cylindrical space configured to arrange the first die therein, a third die having a second recess to be combined with the first recess to form the elliptical-cylindrical space;
• placing the flat metal stock over the first recess;
• inserting the first die along a radial direction of the first die to the first recess of the second die over which the metal stock is placed so as to press the metal stock;
• and
• moving the third die relative to the first die inserted to the first recess so as to confine the first die and the metal stock in the elliptical-cylindrical space formed by the first recess and the second recess, thereby pressing an unpressed portion of the metal stock that is not inserted to the first recess,
• wherein a portion on an outer circumferential surface of the first die, which faces the first recess, has a smaller curvature radius than a portion of the first recess facing the portion on the outer circumferential surface of the first die,
• wherein an insertion direction of the first die and an insertion direction of the third die are each parallel to a major axis of the elliptical-cylindrical space, the major axis of the elliptical-cylindrical space being longer than a minor axis of the elliptical-cylindrical space,
• wherein the first die includes a first portion to be inserted into the first recess and a second portion to be inserted into the second recess, and
• wherein, in comparison in length in a direction parallel to the minor axis at a position distanced from the minor axis by the same distance, a length of the first portion is smaller than a length of the second portion.