2. Development of servo-press for precision forging process
The high performance servo-press machine FPS-1200, co-developed by Sumitomo Heavy Industries and
Yamanaka Eng Co., was used in this study. The exterior of FPS-1200 is shown in Fig. 1 and the detailed
specifications are listed in Table 1. The FPS-1200 system, used with a 500 kW servo motor, can preserve a
maximum forming load of 1,200 ton and a maximum forming speed of 135.2 mm/sec during a 5.5 mm stroke from
the bottom dead center. In addition to the main slide driven by the servo motor, FPS-1200 has three hydraulic servo
driven cushions, namely, one upper die cushion and two lower die cushions. This facilitates a four axis motion
control, with flexible motion definition for each axis. The capability of handling such complex and flexible motion
definition is one of the unique and strong features of the servo-press, distinguishing it from the conventional press
machines.