Method for manufacturing rack bar

Abstract

A method for manufacturing a rack bar includes joining axial end portions of first and second bar members to each other, and forming a power transmission section on the second bar member. The first bar member has a toothed portion. When the second bar member is hollow, the method may further include thickening a wall of a portion of the second bar member along the axial direction so as to be coaxial with the first bar member. When the second bar member has a greater diameter than the first bar member, the method may further include cutting an outside diameter of a portion of the second bar member in the axial direction so as to be coaxial with the first bar member. The power transmission section is formed on the portion of the second bar member where the wall has been thickened and/or the outside diameter has been cut.

1 - 6 . (canceled) 
     
     
         7 . A method for manufacturing a rack bar, the method comprising:
 joining an axial end portion of the first bar member and an axial end portion of a second bar member to each other, the first bar member having a toothed portion along an axial direction, the toothed portion having a plurality of rack teeth, and the second bar member having a greater diameter than the first bar member,   cutting an outside diameter of at least a portion of the second bar member, that has been joined to the first bar member, in the axial direction such that portion of the second bar member is coaxial with the first bar member, and   forming a power transmission section on the portion of the second bar member where the outside diameter has been cut.   
     
     
         8 . The method according to  claim 7 , further comprising performing a heat-treatment on the power transmission section formed on the second bar member. 
     
     
         9 . The method according to  claim 7 , wherein the first bar member and the second bar member are joined to each other by a friction welding, the friction welding including rotating the first bar member and the second bar member relative to each other around a center axis of the first bar member. 
     
     
         10 . The method according to  claim 9 , wherein the first bar member and the second bar member are joined to each other by the friction welding in a state in which the axial end portion of the second bar member is preformed to have a same shape as the axial end portion of the first bar member.