Spherical annular seal member and method of manufacturing the same

Abstract

A spherical annular seal member which has a cylindrical inner surface defining a through hole in a central portion thereof, an outer surface formed in the shape of a partially convex spherical surface, and an annular end face on a large-diameter side of the outer surface, and which is used particularly in an exhaust pipe joint, comprises: a reinforcing member made from a compressed metal wire net; a heat-resistant material filling meshes of the metal wire net of the reinforcing member and compressed in such a manner as to be formed integrally with the reinforcing member in mixed form, the heat-resistant material and the reinforcing member being provided as principal components in an inner portion of the spherical annular seal member which extends from the cylindrical inner surface to the outer surface formed in the shape of the partially convex spherical surface, boron carbide, a metal boride, a metal fluoride, graphite, and aluminum phosphate being also formed integrally with the reinforcing member and the heat-resistant material in mixed form; an outer surface layer formed of boron carbide, a metal boride, a metal fluoride, graphite, and aluminum phosphate; and a reinforcing member made from a compressed metal wire net and formed integrally with the outer surface layer in mixed form, wherein the outer surface formed in the shape of the partially convex spherical surface is formed into a smooth surface where the outer surface layer and the reinforcing member made from the metal wire net and formed integrally with the outer surface layer in mixed form are exposed.