Manufacturing method for a steering column, and steering apparatus that uses that steering column

摘要

Construction is achieved that is capable of maintaining overall strength of a cylindrical-shaped steering column, while at the same time making it possible to make the thickness part of the steering column thin. An outer column 10b, which is a column member of a steering column is formed by connecting in the axial direction a main portion 18 made using a light metal alloy with a cylindrical member 19 made of an iron-based alloy by a concave groove 20 that is formed around the outer circumferential surface of the front end section of the cylindrical member 19 engaging with a protrusion 21 that is formed around the inner circumferential surface of the rear end section of the main portion 18. A ring 22 made using a metallic material is fitted and fastened inside the inner diameter side of the cylindrical member 19 in the connecting section between the main portion 18 and the cylindrical member 19.

主权项

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.