THE MANUFACTURING METHOD OF THE SUSPENSION ARM FOR THE REAR SUSPENSION OF A CAR, AND THE SAME MADE BY THE ABOVE METHOD

摘要

A manufacturing method of a suspension arm for rear suspension of a vehicle, and the suspension arm are provided to improve the productivity of a vehicle by using extruded bars and to improve the fuel ratio of the vehicle by enhancing impact absorption performance of the suspension arm. A manufacturing method of a suspension arm for rear suspension of a vehicle comprises a step of extruding an aluminum alloy extruded bar having a double wall structure in which an external wall is connected to a bottom plate and an internal wall that is bent inward from the upper end of the external wall. The extruded bar is solution treated, and then is subject to a cutting process. The upper end surface of the cut extruded bar is fixed and an upper mold is in close contact with the inner side of the center portion of the extruded bar. A connection mounting section with a sub-frame and a wheel shaft is formed from the extruded bar. The upper mold is separated from the extruded bar and a groove for seating a coil spring is formed in the bottom plate.