| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure capable of securing strength while reducing the thickness of part of a hollow circular tubular steering column 10b.SOLUTION: Drawing is applied to a front end of a cylindrical member 19 made of an iron-based material, so that an inner diameter dimension of a front end face is made smaller than that of a portion of the cylindrical member 19 which is located on the inner diameter side of a portion forming a rear end face of a body portion 18. A portion nearer the front end of the cylindrical member 19 is inserted into an insertion hole 23 opening on an outer face 22 of a mold 21, so as to protrude the portion nearer the front end into the mold 21. Molten light alloy metal is sent to the mold 21 to mold the body portion 18. After taken out from the mold 21, an inner peripheral edge of the front end protruding inwardly in the radial direction of the cylindrical member 19 and a portion on the inner diameter side of the body portion 18 are cut, so that the inner diameter of at least the portion nearer the front end of the cylindrical member 19 is made equal to or larger than that of the body portion 18. |
