JPS5739005A - Multistage rolling mill - Google Patents

Abstract

PURPOSE:To change the diameter of a roll correspondingly to the shape of a material to be rolled, and to permit the shape control for the material to be rolled to be easily performed, by forming a longitudinal middle zone of the drum of an intermediate roll into a solid state, and by providing a gap for receiving a working fluid on longitudinal both sides of this middle solid zone. CONSTITUTION:In a multistage rolling mill, a longitudinal almost middle part of the drum of an intermediate roll 3 is formed into a solid state, and longitudinal both sides of this middle solid part are formed into a hollow cylinder having a tapered inner surface; a shaft 4 is then fitted into this hollow cavity so as to form a conical annular gap 5 between the shaft 4 and the inner surface of the hollow cavity of the intermediate roll 3. A working fluid at about maximum required pressure is supplied into this gap 5 through the oil paths 7, 6 in order to expand from inside the parts except the middle solid part of the roll 3. Under this condition, the outer surface of the roll 3 is ground so as to finish the main part of the outer surface into a straight cylinder and its both sides into a slightly tapered shape. When the roll 3 serves in a rolling process, a required pressure corresponding to the breadth, etc., of the material to be rolled is imparted to the gap 5 in order to place the straight cylindrical outer surface of the intermediate roll 3 under a proper condition, and thereupon, the rolling process is performed.