JPS6449610A - Manufacture of roll mold - Google Patents

Abstract

PURPOSE:To obtain easily the mold having large crown amount and reverse crown amount by a method in which the outer surface of a matrix is worked by cutting, and the matrix is inserted into a holding mold, heated and cooled in said mold and pulled out therefrom, and the series of processes is repeated. CONSTITUTION:The inner surface 2 of the straight cylindrical body made of the metal with relatively large expansion coefficient is finished into a mirror surface. The outer surface 3 of said cylindrical body is worked by cutting into the shape symmetrical with the desired shape of the outer peripheral surface of a roll, thereby obtaining a matrix 1. The matrix 1 is inserted into the holding mold 5 made of the material with relatively small linear expan sion coefficient and is totally heated, whereby the matrix 1 is expanded, and then the outer peripheral surface 3 of the matrix is brought in contact with the inner surface of the holding mold, and is deformed reversely. Next, after its cooling, the reversed matrix 1 is pulled out or said matrix, as it is, is used as the roll mold 7 for cast molding. As the material of the matrix, e.g. aluminum is used, and as the material of the holding mold, iron or ceramic is used. After the inner and outer surfaces of the matrix have been worked into uniform diameter, its inner surface is precisely finished into mirror surface (inner diameter d1), and its outer surface is worked by cutting into the shape (maximum diameter D1) in opposition to the desired roll shape. The inner surface of the holding mold is worked into uniform diameter D2 in consideration to the outer diameter of the matrix.