Link rod manufacturing method

A method of manufacturing a link rod which comprises an arm portion having a longitudinally extending configuration, and a bush mounting bracket being joined to an end in the longitudinal direction of said arm portion, wherein said arm portion has a pair of first and second walls extending in parallel with each other and a third wall connecting between said first and second walls, comprising the steps of forming a notch by cutting out an end in the longitudinal direction of said third wall of said arm portion, extrusion molding a bracket material for forming a plurality of said bush mounting brackets by being cut in the longitudinal direction thereof, having an engaging projection which is integrally formed with said bracket material, engaged with said notch of said third wall provided on the longitudinal end of said arm portion, butting the longitudinal end of said arm portion against said bracket material such that a wall of said bracket material is butted against each of ends of said first and second walls to form a flush tool traveling surface, arranging in a horizontal row in the longitudinal direction of said bracket material a plurality of said arm portions in a butted state against said bracket material, such that butt portions of said arm portions each are continuously formed in the shape of a straight line along the direction of the row, friction stir welding continuously each of said arm portions and said bracket material in one process step along said continuously formed butt portions, and cutting said bracket material at a predetermined width of a product in the longitudinal direction thereof to have link rods in a horizontal row separated into each link rod.

A method of manufacturing a link rod which comprises a longitudinally extending arm having a pair of first and second walls being formed in parallel in a cross section crossing at right angles the longitudinal direction of the arm and a third wall connecting between said first and second walls, and a bush mounting bracket having a bush mounting hole and being integrally formed with an engaging projection to be engaged between said first and second walls on an longitudinal end of said arm, wherein said bush mounting bracket is friction stir welded to and formed integral with the longitudinal end of said arm, comprises the steps of forming a bracket material by carrying out extrusion molding such that a cross section of an extrusion has a configuration of a front view of said bush mounting bracket when viewed from an axial direction of said bush mounting hole and is formed integral with said engaging projection and then by cutting the extrusion in the longitudinal direction thereof at such a predetermined length that a plurality of said bush mounting brackets are arranged in a horizontal row, forming an arm material by carrying out extrusion molding such that a cross section of an extrusion corresponds to such a cross section in the direction crossing at a right angle the longitudinal direction of said arm, that a plurality of said arms are arranged in a horizontal row, and such that the width of the extrusion corresponds to the cut length of said bracket material and then by cutting the extrusion in the longitudinal direction thereof at the predetermined length of said arm, notching each end in the longitudinal direction of said third wall with respect to said arm material to form a clearance in the case of having engaged with said engaging projection, arranging said bracket material and said arm material in such a state that the extrusion directions of these materials cross at right angle each other, so as to engage said engaging projection integrally formed with said bracket material between said first and second walls on the end of the extrusion direction of said arm material, having said first and second walls butted against said bracket material to form a butt portion in the shape of a flush and continuous straight line, friction stir welding said arm material and said bracket material in one process step along said butt portion, and then cutting such joined materials at the width of a product in the direction crossing at right angle the extrusion direction of said arm material.