Method for manufacturing ring-shaped member and manufacturing apparatus for same

A manufacturing apparatus for a ring-shaped member comprising:

• a mandrel;
• and
• an outer-diameter constraining die;
• the manufacturing apparatus used for forming the ring-shaped member by performing a rolling process on an inner-circumferential surface and an outer-circumferential surface of an annular-shaped metal blank;
• the mandrel comprising:
• a pair of support shaft sections;
• and
• a rolling shaft section;
• the mandrel rotatably supported around a center axis of the mandrel,
• the pair of support shaft sections having a larger diameter than the rolling shaft section, and provided so as to be separated from each other and concentric with each other in an axial direction of the mandrel;
• and
• the rolling shaft section provided between the pair of support shaft sections so as to be concentric with the pair of support shaft sections, and having a first rolling surface for performing the rolling process on the inner-circumferential surface of the metal blank formed around an outer-circumferential surface of the rolling shaft;
• the outer-diameter constraining die having an annular shape;
• comprising a center axis, and a second rolling surface for performing the rolling process on the outer-circumferential surface of the metal blank formed around an inner-circumferential surface of the outer-diameter constraining die;
• supported in a state in which the center axis of the outer-diameter constraining die is parallel with the center axis of the mandrel rotatably around the center axis of the outer-diameter constraining die;
• and
• arranged so that the rolling shaft section is inserted into an inner-diameter side of the outer-diameter constraining die and the second rolling surface faces the first rolling surface;
• wherein at least one support shaft section of the pair of support shaft sections is formed separately from the rolling shaft section, and during processing of the metal blank, and when the at least one support shaft section receives a specified pressing force in the axial direction from the metal blank, the at least one support shaft section is able to displace in the axial direction in a direction going away from the rolling shaft section, allowing a molding space that is defined by the first rolling surface of the mandrel, the second rolling surface of the outer-diameter constraining die, and end surfaces on the rolling shaft section side of the pair of support shaft sections to expand;
• and
• the manufacturing apparatus is capable of forming the ring-shaped member, in which part of a circumferential direction of the metal blank is arranged in the molding space, by rotating the mandrel around the center axis of the mandrel together with rotating the outer-diameter constraining die around the center axis of the outer-diameter constraining die, and pressing the metal blank between the first rolling surface and the second rolling surface so as to perform the rolling process on the inner-circumferential surface and the outer-circumferential surface of the annular-shaped metal blank,
• wherein
• the outer-diameter constraining die comprises a plurality of outer-diameter constraining die elements having an annular shape and arranged side-by-side in the axial direction;
• the second rolling surface is constructed by inner-circumferential surfaces of the plurality of outer-diameter constraining die elements;
• the outer-diameter constraining die is able to perform the rolling process corner sections that are connecting sections between the outer-circumferential surface and both ends in the axial direction of the metal blank in order to form chamfer sections together with on the outer-circumferential surface of the metal blank;
• and
• the plurality of outer-diameter constraining die elements are able to displace in a direction going away from each other to form an axial-direction gap between the plurality of outer diameter constraining die elements when, during processing of the metal blank, specified pressing forces in the axial direction are received from the metal blank.