Method of cooling main roll for ring rolling and method of manufacturing ring rolled body

Abstract

In a method of cooling a main roll, strength of a shaft and a peripheral portion thereof of the main roll is sufficiently secured, maintenance of the main roll is facilitated, and the shaft and the peripheral portion thereof of the main roll are efficiently cooled. In a method of manufacturing a ring rolled body, a high-quality ring rolled body is produced. The present invention relates to a method of cooing a main roll 1 for ring rolling in a state in which one side, in the rotation axis direction, of the main roll 1 faces upward, and relates to a method of manufacturing a ring rolled body, including the cooling method. In the cooling method, the shaft 11 is cooled by injecting a liquid W into a receiving part 13, 17 which is recessed from an upper end surface 12c of a die 12 of the main roll 1 facing the one side in the rotation axis direction and surrounds the shaft 11 of the main roll 1. In the method of manufacturing a ring rolled body, a ring rolled body is manufactured by heating the die 12 by an induction heating mechanism 6 and cooling the shaft 11 by the cooling method, and further, reducing a ring material M between the main roll 1 and the mandrel 2.

1 . A method of cooling a main roll, the main roll including a shaft extending along a rotation axis of the main roll and a die disposed so as to surround the shaft, the main roll being used for ring rolling, the main roll being cooled in a state in which one side in a rotation axis direction faces upward, the method comprising:
 cooling the shaft of the main roll by injecting a liquid into a receiving part, the receiving part being recessed from an upper end surface of the die of the main roll facing the one side in the rotation axis direction, the receiving part surrounding the shaft of the main roll.   
     
     
         2 . The method of cooling the main roll according to  claim 1 , wherein
 the liquid injected into the receiving part, flows through a plurality of liquid passages which extend from the receiving part to the other side in the rotation axis direction and are spaced apart from each other in a circumferential direction of the main roll, in the die.   
     
     
         3 . The method of cooling the main roll according to  claim 2 , wherein
 the liquid flowing into at least one liquid passage among the plurality of the liquid passages, is discharged to an outside of the main roll from an outlet of the at least one liquid passage which opens at a lower end surface of the die located on the other side in the rotation axis direction.   
     
     
         4 . The method of cooling the main roll according to  claim 2 , wherein
 the liquid flowing into at least one liquid passage among the plurality of the liquid passages, is stored on and above a bottom formed on the at least one liquid passage having a blind hole shape.   
     
     
         5 . A method of manufacturing a ring rolled body to produce the ring rolled body by rolling a ring material, the method comprising:
 a temperature control step of heating a die of a main roll by a heating mechanism, and cooling a shaft of the main roll by the method of cooling the main roll, according to  claim 1 ; and   a rolling step of performing reduction between an inner periphery and an outer periphery of the ring material by the main roll on which temperature control is performed in the temperature control step, and by a mandrel.