| 摘要 |
Provided is a production method for an outer member for wheel bearing devices, using less material and having improved strength and improved rolling fatigue life. This production method comprises: a step in which a rod-shaped material has a center section thereof that is diameter-expanded and molded into a drum shape, by upsetting; a step in which a disc-shaped punched bore section (17) is molded by forging in substantially a center section, in the axial direction, between an outer circumferential section of an outer member (10), a cylindrical inner circumferential section including a plurality of rows of outside rolling surfaces (2a), and the plurality of rows of outside rolling surfaces (2a) in this inner circumferential section; and a step in which the punched bore section (17) is removed by punch boring using a punch. The distance (L1) from an end surface (17a) of the punched bore section (17) to the groove bottom of the outside rolling surfaces (2a) is set within a range of L1 = 0.15-0.4R, when R is the radius of curvature for the outer rolling surfaces (2a). When the thickness of the groove bottom section of the outside rolling surfaces (2a) is H1 and the thickness of the outer member (10) is H2, at the groove bottom position of the outside rolling surfaces (2a), H1 and H2 are set such that H2 = 1.3-2.0H1. |
