| 摘要 |
PROBLEM TO BE SOLVED: To provide a technical knowledge capable of easily maintaining a uniform quality and cost decreasing. SOLUTION: This technical knowledge comprises a process to draw a work 30 with a previously prepared hole in the center to form a cylindrical body with bottom, a process to reversely draw the center part of this cylindrical body with bottom to form a small diametral cylindrical part toward the opening side, a process to reduce the diameter of this small diametral cylindrical part and crush the part in the axial direction thus to make the body into a boss 4 increasing the thickness, and a process to form a spline teeth profil on the inner peripheral surface by clamping three places of the outer peripheral surface 4a, the base end 4b and the tip end 4c of this boss 4 and then under this situation by squeezing a spline teeth profile punch into the inner peripheral surface of the boss 4. Thereby, even when a teeth profile punch with a diameter larger than the hole of a boss is squeezed into the hole of the boss, there is no fear that the boss swells outward pushed by the teeth profile punch. |
