Method of making a catalytic converter for use in an internal combustion engine

Abstract

The invention is directed at a method of manufacturing these catalytic converters having non-round honeycomb substrates and comprises the following steps: (1) wrapping a non-round monolithic ceramic substrate, having a major and minor orthogonal axis, in a sufficient amount of the supporting mat material whereby the substrate's peripheral surface is substantially covered; (2) inserting the wrapped substrate into a metal shell, having a plurality of nodal points, which substantially surrounds the wrapped substrate; (3) placing the metal shell in a resizing die having a plurality of fingers, and associated gaps therebetween, extending axially along substantially the entire surface of the metal shell whereby the nodal points of the metal shell are positioned along a portion of a die finger and the placement of the metal shell and wrapped substrate, within the resizing die is such that the axes of the resizing die are angularly offset from the major and minor axes of the substrate; (4) compressively closing the container around the wrapped substrate by displacing the fingers of the resizing die radially inward to provide a gas tight seal and to hold the compressive stress by; and, (5) securing the metal shell to provide a gas tight seal and to hold the compressive stress.