Ring molded article manufacturing method

Abstract

A ring molded article manufacturing method capable of reliably and efficiently producing a ring molded article in which dead metal regions are reduced, is provided. In the present invention, a material is processed by first forging so as to be shaped in a shape including a bottom which is formed in a substantially disk shape, and a peripheral wall which is inclined to a direction from a center of the bottom toward an outer periphery thereof, in a direction from the outer periphery of the bottom toward one side in a direction of a center axis of the bottom, the bottom of a first forged article obtained by the first forging is drilled, a drilled article obtained by the drilling is ring-rolled, a ring material obtained by the ring rolling is placed inside two molds, the ring material is then processed by second forging so as to be pressed by the two molds in a direction of a center axis of the ring material, and the ring molded article is thus produced.

1 . A ring molded article manufacturing method comprising:
 a step of performing first forging on a material such that the material is formed in a shape including a bottom which is formed in a disk shape, and a peripheral wall which is inclined to a direction from a center of the bottom toward an outer periphery thereof, in a direction from an outer periphery of the bottom toward one side in a direction of a center axis of the bottom;   a step of drilling the bottom of a first forged article obtained by the step: of performing the first forging;   a step of ring-rolling a drilled article obtained by the step of drilling; and   a step of producing a ring molded article in which a ring material obtained by the step of ring-rolling is placed inside two molds, the ring material is then processed by second forging so as to be pressed by the two molds in a direction of a center axis of the ring material, and the ring molded article is thus produced.   
     
     
         2 . The ring molded article manufacturing method according to  claim 1 , wherein
 the ring molded article includes two convex portions which respectively protrude on both sides of the ring molded article in a direction of a center axis thereof and extend in a direction of a circumference of the ring molded article,   concave portions respectively corresponding to the convex portions of the ring molded article are formed on the two molds respectively, and   the ring material placed inside the two molds is supported by a region located on an outer peripheral side from an outer peripheral side corner m the concave portion of one of the two molds and a region located on an inner peripheral side from an inner peripheral side corner in the concave portion of another of the two molds.   
     
     
         3 . The ring molded article manufacturing method according to  claim 1 , wherein
 in the step of performing the first forging, if a one half section of the peripheral wall is divided into a one side region and an another side region in the direction of the center axis of the first forged article based on a middle of a maximum height of the first forged article in the direction of the center axis of the first forged article, a straight line passing through a center of gravity of the one side region and a center of gravity of the another side region is inclined by an angle relative to the center axis of the first forged article, of which a range is 7 degrees to 40 degrees.   
     
     
         4 . The ring molded article manufacturing method according to  claim 1 , wherein
 if a one half section of the ring material placed inside the two molds is divided into a one side region and an other side region in the direction of the center axis of the ring material based on a middle of a maximum height of the ring material in the direction of the center axis of the ring material, a straight line passing through a center of gravity of the one side region and a center of gravity of the another side region is inclined by m angle relative to the center axis of the ring material, of which a range is 7 degrees to 40 degrees.