Development of Precision Rolling Machine

This paper proposes a rolling machine that forms fine corrugated section patterns for thin sheets. A prototype of the machine was made and the performance of the machine was tested. As compared with press forming, rolling has the advantages of the high forming limit, the low forming reaction force, the easy control of the thin sheet's curve and high productivity. We confirmed these four advantages by using finite element analyses and the prototype rolling machine. Stainless steel sheets and titanium sheets, which were one of the materials with a low forming limit, were used. Firstly, the rolling showed a 1.3-times higher forming limit than the press forming in the case that a fine corrugated section pattern was formed in a stainless steel sheet of 22-mm square sizes. Secondly, the forming reaction force of the rolling was about one-twentieth of the press forming without coining, and the experimental results agreed with the finite element simulation. As for the third advantage of the control of the thin sheet's curve, formed sheets with little curve were obtained by choosing a suitable angle. Fourthly, the trimming process, which was necessary for realizing high productivity, was examined. The half cut process by the rotary cutter, which was used to cut stainless steel sheets with PET films, was applied to the trimming process. The effect of the sword angle on cutting the section shape was investigated. Finally, the possibility of a high speed and mass production process for forming metal sheets with a fine corrugated section pattern was demonstrated by connecting the trimming machine to the rolling machine.