Patent ID: 8635775
Filing Date: 2014-01-28
Classification: B21J,B21K,F16C,Y10T

Abstract:
1. A process for manufacturing a bearing ring member of a rolling bearing unit for wheel support that comprises an outward facing flange formed around a part of an outer peripheral surface thereof, a positioning cylinder that is formed on one side in an axial direction of the outward facing flange, and a step section that is formed around an outer peripheral surface of a side of the outward facing flange that is opposite in the axial direction from the positioning cylinder and that has a large diameter section on the side of the outward facing flange, and a small diameter section on the far side from the outward facing flange; where in order to manufacture this bearing ring member, a metallic material is prepared that has at least a cylindrical surface section with an outer diameter that matches the outer diameter of the large diameter section of the step section, and without heating this metallic material, a tip end surface of the cylindrical surface section, which is the surface on the opposite side from the outward facing flange, is brought into contact with a receiving punch that has an inner diameter that matches the outer diameter of the small diameter section, and with at least a part of an outer peripheral surface of the cylindrical surface section being supported by an inner peripheral surface of a floating die, which is supported such that it is capable of moving in the axial direction of the cylindrical surface section, it is in a state of having an elastic force applied to it in the direction toward the outward facing flange, and a base end surface of the metallic material, which is the surface on the side opposite the surface that is in contact with the receiving punch, is pressed toward the receiving punch by a pressing punch such that the part of the cylindrical surface section is pressed into the receiving punch to form the small diameter section by cold plastic working.