Rolling Force on Steel Ball Rolling Dies

Abstract

An apparatus measuring the three components of the rolling force was set up on the experimental steel ball rolling machine in order to obtain design data for a steel ball rolling machine. The three components of the rolling force were measured under various rolling conditions on the following three kinds of rolling dies : Type A designed so as to disconnect adjacent rolled balls, Type B designed so as to leave the connecting part of rolled balls and Type C designed so as to have gradual feeding. The form of the rolling force curve of each type was similar to that of calculated curve of the contact area of the ball rolling die and the blank. Three components of the rolling force were greatly affected by the setting position of each pair of rolling dies. These three components increased with the increase of the diameter of a rolled blank and decreased with the increase of the heating temperature of the rolled blank. At the range of 16 to 20 mm diameters of the manufactured steel balls, the revolutions of the rolling dies 200 to 300 rpm were recommended. The application of a proper lubricant was effective to decrease the rolling force.