Spin-forming method for making catalytic converter

摘要

A method is provided for forming a catalytic converter that includes a catalyst substrate having a noncircular circumference and surrounded by a metal housing. The catalyst substrate is initially measured to determine the radial dimension of the substrate circumference relative to a central axis. The substrate is wrapped in a compressible mat and arranged within a metal tube. The arrangement is subjected to a spin-forming process that forms the metal tube about the catalyst substrate. The spin-forming process includes rotating the metal tube about the substrate axis, while concurrently urging a metal-forming tool against the metal tube. The metal-forming tool is programmed to follow a metal-forming path corresponding to the substrate circumference plus a predetermined radial distance. In this manner, a metal housing is formed having a noncircular circumference corresponding in shape to the catalyst substrate and spaced apart by a uniform insulative layer.