Patent ID: 8960044
Filing Date: 2015-02-24
Classification: B22D,B62D

Abstract:
1. A manufacturing method of a steering column having a cylindrical shape as a whole and comprising a column member, the column member comprising: a main portion that is made using a light metal alloy, and comprises a convex section provided at one location or more in the circumferential direction on a circumferential surface on one end thereof; a cylindrical member that is made using an iron-based alloy, and comprises a concave section at one location or more in the circumferential direction on a circumferential surface on one end thereof that faces the circumferential surface of the main portion, and together with fitting with the main portion, is connected in the axial direction to the main portion by the engagement of the convex section and concave section; and a ring that is made using a metal material, and is fitted and fastened on an inner diameter side of a connecting section between the main portion and the cylindrical member, the manufacturing method of the steering column comprising the steps of: fitting the ring inside the one end of the cylindrical member; inserting the one end of the cylindrical member into an insertion through hole that is open on an end surface of a die to protrude the one end of the cylindrical member inside the die; inserting an end section of a core cylinder into the ring; and feeding molten light metal alloy into the die to form the main portion and causing part of the molten light metal alloy to enter into the concave section to form the convex section on the circumferential surface of the main portion.