Steering apparatus for a car and method of manufacturing the same

Abstract

In a steering apparatus for a car which presses and retains a steering column upon a fixing bracket to car body to be telescopically adjustable, the steering column is molded from a tubular material by a hydroforming process to have a swelled portion as a unitary structure thereof. There is formed on each side surface of this swelled portion an elongated hole for telescopic adjustment through which a fastening bolt of a clamp mechanism provided on a fixed bracket to steering column is inserted.

What is claimed is:  
     
         1 . A steering apparatus for a car which presses and retains a steering column upon a fixing bracket to car body to be telescopically adjustable, which steering apparatus is characterized in that: 
 said steering column is molded from a tubular material by a hydroforming process to have a swelled portion as a unitary structure thereof, and there is formed on each side surface of this swelled portion an elongated hole for telescopic adjustment through which a fastening bolt of a clamp mechanism provided on a fixed bracket to steering column is inserted.    
     
     
         2 . A steering apparatus for a car according to  claim 1 , wherein, on at least one of the side surfaces of the swelled portion of the steering column, a large number of linear ribs are integrally molded in the axial direction thereof for tilt adjustment or in a direction perpendicular to the axial direction for telescopic adjustment, so as to be meshed with gears provided on said fixed bracket to steering column.  
     
     
         3 . A method of manufacturing a steering apparatus for a car which presses and retains a steering column to a fixing bracket to car body to be telescopically adjustable, which manufacturing method comprising the steps of: 
 molding a tubular material into said steering column by a hydroforming process to have a swelled portion as a unitary structure thereof; and    forming, on each side surface of this swelled portion, an elongated hole for telescopic adjustment through which a fastening bolt of a clamp mechanism provided on said fixing bracket to car body.